lix/src/libexpr/primops.cc

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#include "archive.hh"
#include "derivations.hh"
#include "eval-inline.hh"
#include "eval.hh"
#include "globals.hh"
#include "json-to-value.hh"
#include "names.hh"
#include "store-api.hh"
#include "util.hh"
Add support for passing structured data to builders Previously, all derivation attributes had to be coerced into strings so that they could be passed via the environment. This is lossy (e.g. lists get flattened, necessitating configureFlags vs. configureFlagsArray, of which the latter cannot be specified as an attribute), doesn't support attribute sets at all, and has size limitations (necessitating hacks like passAsFile). This patch adds a new mode for passing attributes to builders, namely encoded as a JSON file ".attrs.json" in the current directory of the builder. This mode is activated via the special attribute __structuredAttrs = true; (The idea is that one day we can set this in stdenv.mkDerivation.) For example, stdenv.mkDerivation { __structuredAttrs = true; name = "foo"; buildInputs = [ pkgs.hello pkgs.cowsay ]; doCheck = true; hardening.format = false; } results in a ".attrs.json" file containing (sans the indentation): { "buildInputs": [], "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash", "configureFlags": [ "--with-foo", "--with-bar=1 2" ], "doCheck": true, "hardening": { "format": false }, "name": "foo", "nativeBuildInputs": [ "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10", "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03" ], "propagatedBuildInputs": [], "propagatedNativeBuildInputs": [], "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv", "system": "x86_64-linux" } "passAsFile" is ignored in this mode because it's not needed - large strings are included directly in the JSON representation. It is up to the builder to do something with the JSON representation. For example, in bash-based builders, lists/attrsets of string values could be mapped to bash (associative) arrays.
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#include "json.hh"
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#include "value-to-json.hh"
#include "value-to-xml.hh"
#include "primops.hh"
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <algorithm>
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#include <cstring>
#include <regex>
#include <dlfcn.h>
#include <cmath>
namespace nix {
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/*************************************************************
* Miscellaneous
*************************************************************/
InvalidPathError::InvalidPathError(const Path & path) :
EvalError("path '%s' is not valid", path), path(path) {}
void EvalState::realiseContext(const PathSet & context)
{
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std::vector<DerivedPath::Built> drvs;
for (auto & i : context) {
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auto [ctxS, outputName] = decodeContext(i);
auto ctx = store->parseStorePath(ctxS);
if (!store->isValidPath(ctx))
throw InvalidPathError(store->printStorePath(ctx));
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if (!outputName.empty() && ctx.isDerivation()) {
drvs.push_back({ctx, {outputName}});
}
}
if (drvs.empty()) return;
if (!evalSettings.enableImportFromDerivation)
throw EvalError("attempted to realize '%1%' during evaluation but 'allow-import-from-derivation' is false",
store->printStorePath(drvs.begin()->drvPath));
/* For performance, prefetch all substitute info. */
StorePathSet willBuild, willSubstitute, unknown;
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uint64_t downloadSize, narSize;
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std::vector<DerivedPath> buildReqs;
for (auto & d : drvs) buildReqs.emplace_back(DerivedPath { d });
store->queryMissing(buildReqs, willBuild, willSubstitute, unknown, downloadSize, narSize);
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store->buildPaths(buildReqs);
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/* Add the output of this derivations to the allowed
paths. */
if (allowedPaths) {
for (auto & [drvPath, outputs] : drvs) {
auto outputPaths = store->queryDerivationOutputMap(drvPath);
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for (auto & outputName : outputs) {
if (outputPaths.count(outputName) == 0)
throw Error("derivation '%s' does not have an output named '%s'",
store->printStorePath(drvPath), outputName);
allowedPaths->insert(store->printStorePath(outputPaths.at(outputName)));
}
}
}
}
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/* Add and attribute to the given attribute map from the output name to
the output path, or a placeholder.
Where possible the path is used, but for floating CA derivations we
may not know it. For sake of determinism we always assume we don't
and instead put in a place holder. In either case, however, the
string context will contain the drv path and output name, so
downstream derivations will have the proper dependency, and in
addition, before building, the placeholder will be rewritten to be
the actual path.
The 'drv' and 'drvPath' outputs must correspond. */
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static void mkOutputString(EvalState & state, Value & v,
const StorePath & drvPath, const BasicDerivation & drv,
std::pair<string, DerivationOutput> o)
{
auto optOutputPath = o.second.path(*state.store, drv.name, o.first);
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mkString(
*state.allocAttr(v, state.symbols.create(o.first)),
optOutputPath
? state.store->printStorePath(*optOutputPath)
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/* Downstream we would substitute this for an actual path once
we build the floating CA derivation */
/* FIXME: we need to depend on the basic derivation, not
derivation */
: downstreamPlaceholder(*state.store, drvPath, o.first),
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{"!" + o.first + "!" + state.store->printStorePath(drvPath)});
}
/* Load and evaluate an expression from path specified by the
argument. */
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static void import(EvalState & state, const Pos & pos, Value & vPath, Value * vScope, Value & v)
{
PathSet context;
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Path path = state.coerceToPath(pos, vPath, context);
try {
state.realiseContext(context);
} catch (InvalidPathError & e) {
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
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.msg = hintfmt("cannot import '%1%', since path '%2%' is not valid", path, e.path),
.errPos = pos
});
} catch (Error & e) {
e.addTrace(pos, "while importing '%s'", path);
throw e;
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}
Path realPath = state.checkSourcePath(state.toRealPath(path, context));
// FIXME
auto isValidDerivationInStore = [&]() -> std::optional<StorePath> {
if (!state.store->isStorePath(path))
return std::nullopt;
auto storePath = state.store->parseStorePath(path);
if (!(state.store->isValidPath(storePath) && isDerivation(path)))
return std::nullopt;
return storePath;
};
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if (auto optStorePath = isValidDerivationInStore()) {
auto storePath = *optStorePath;
Derivation drv = state.store->readDerivation(storePath);
Value & w = *state.allocValue();
state.mkAttrs(w, 3 + drv.outputs.size());
Value * v2 = state.allocAttr(w, state.sDrvPath);
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mkString(*v2, path, {"=" + path});
v2 = state.allocAttr(w, state.sName);
mkString(*v2, drv.env["name"]);
Value * outputsVal =
state.allocAttr(w, state.symbols.create("outputs"));
state.mkList(*outputsVal, drv.outputs.size());
unsigned int outputs_index = 0;
for (const auto & o : drv.outputs) {
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mkOutputString(state, w, storePath, drv, o);
outputsVal->listElems()[outputs_index] = state.allocValue();
mkString(*(outputsVal->listElems()[outputs_index++]), o.first);
}
w.attrs->sort();
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static RootValue fun;
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if (!fun) {
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fun = allocRootValue(state.allocValue());
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state.eval(state.parseExprFromString(
#include "imported-drv-to-derivation.nix.gen.hh"
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, "/"), **fun);
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}
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state.forceFunction(**fun, pos);
mkApp(v, **fun, w);
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state.forceAttrs(v, pos);
}
else if (path == corepkgsPrefix + "fetchurl.nix") {
state.eval(state.parseExprFromString(
#include "fetchurl.nix.gen.hh"
, "/"), v);
}
else {
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if (!vScope)
state.evalFile(realPath, v);
else {
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state.forceAttrs(*vScope);
Env * env = &state.allocEnv(vScope->attrs->size());
env->up = &state.baseEnv;
StaticEnv staticEnv(false, &state.staticBaseEnv);
unsigned int displ = 0;
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for (auto & attr : *vScope->attrs) {
staticEnv.vars[attr.name] = displ;
env->values[displ++] = attr.value;
}
Add primop ‘scopedImport’ ‘scopedImport’ works like ‘import’, except that it takes a set of attributes to be added to the lexical scope of the expression, essentially extending or overriding the builtin variables. For instance, the expression scopedImport { x = 1; } ./foo.nix where foo.nix contains ‘x’, will evaluate to 1. This has a few applications: * It allows getting rid of function argument specifications in package expressions. For instance, a package expression like: { stdenv, fetchurl, libfoo }: stdenv.mkDerivation { ... buildInputs = [ libfoo ]; } can now we written as just stdenv.mkDerivation { ... buildInputs = [ libfoo ]; } and imported in all-packages.nix as: bar = scopedImport pkgs ./bar.nix; So whereas we once had dependencies listed in three places (buildInputs, the function, and the call site), they now only need to appear in one place. * It allows overriding builtin functions. For instance, to trace all calls to ‘map’: let overrides = { map = f: xs: builtins.trace "map called!" (map f xs); # Ensure that our override gets propagated by calls to # import/scopedImport. import = fn: scopedImport overrides fn; scopedImport = attrs: fn: scopedImport (overrides // attrs) fn; # Also update ‘builtins’. builtins = builtins // overrides; }; in scopedImport overrides ./bla.nix * Similarly, it allows extending the set of builtin functions. For instance, during Nixpkgs/NixOS evaluation, the Nixpkgs library functions could be added to the default scope. There is a downside: calls to scopedImport are not memoized, unlike import. So importing a file multiple times leads to multiple parsings / evaluations. It would be possible to construct the AST only once, but that would require careful handling of variables/environments.
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printTalkative("evaluating file '%1%'", realPath);
Expr * e = state.parseExprFromFile(resolveExprPath(realPath), staticEnv);
Add primop ‘scopedImport’ ‘scopedImport’ works like ‘import’, except that it takes a set of attributes to be added to the lexical scope of the expression, essentially extending or overriding the builtin variables. For instance, the expression scopedImport { x = 1; } ./foo.nix where foo.nix contains ‘x’, will evaluate to 1. This has a few applications: * It allows getting rid of function argument specifications in package expressions. For instance, a package expression like: { stdenv, fetchurl, libfoo }: stdenv.mkDerivation { ... buildInputs = [ libfoo ]; } can now we written as just stdenv.mkDerivation { ... buildInputs = [ libfoo ]; } and imported in all-packages.nix as: bar = scopedImport pkgs ./bar.nix; So whereas we once had dependencies listed in three places (buildInputs, the function, and the call site), they now only need to appear in one place. * It allows overriding builtin functions. For instance, to trace all calls to ‘map’: let overrides = { map = f: xs: builtins.trace "map called!" (map f xs); # Ensure that our override gets propagated by calls to # import/scopedImport. import = fn: scopedImport overrides fn; scopedImport = attrs: fn: scopedImport (overrides // attrs) fn; # Also update ‘builtins’. builtins = builtins // overrides; }; in scopedImport overrides ./bla.nix * Similarly, it allows extending the set of builtin functions. For instance, during Nixpkgs/NixOS evaluation, the Nixpkgs library functions could be added to the default scope. There is a downside: calls to scopedImport are not memoized, unlike import. So importing a file multiple times leads to multiple parsings / evaluations. It would be possible to construct the AST only once, but that would require careful handling of variables/environments.
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e->eval(state, *env, v);
}
Add primop ‘scopedImport’ ‘scopedImport’ works like ‘import’, except that it takes a set of attributes to be added to the lexical scope of the expression, essentially extending or overriding the builtin variables. For instance, the expression scopedImport { x = 1; } ./foo.nix where foo.nix contains ‘x’, will evaluate to 1. This has a few applications: * It allows getting rid of function argument specifications in package expressions. For instance, a package expression like: { stdenv, fetchurl, libfoo }: stdenv.mkDerivation { ... buildInputs = [ libfoo ]; } can now we written as just stdenv.mkDerivation { ... buildInputs = [ libfoo ]; } and imported in all-packages.nix as: bar = scopedImport pkgs ./bar.nix; So whereas we once had dependencies listed in three places (buildInputs, the function, and the call site), they now only need to appear in one place. * It allows overriding builtin functions. For instance, to trace all calls to ‘map’: let overrides = { map = f: xs: builtins.trace "map called!" (map f xs); # Ensure that our override gets propagated by calls to # import/scopedImport. import = fn: scopedImport overrides fn; scopedImport = attrs: fn: scopedImport (overrides // attrs) fn; # Also update ‘builtins’. builtins = builtins // overrides; }; in scopedImport overrides ./bla.nix * Similarly, it allows extending the set of builtin functions. For instance, during Nixpkgs/NixOS evaluation, the Nixpkgs library functions could be added to the default scope. There is a downside: calls to scopedImport are not memoized, unlike import. So importing a file multiple times leads to multiple parsings / evaluations. It would be possible to construct the AST only once, but that would require careful handling of variables/environments.
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}
}
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static RegisterPrimOp primop_scopedImport(RegisterPrimOp::Info {
.name = "scopedImport",
.arity = 2,
.fun = [](EvalState & state, const Pos & pos, Value * * args, Value & v)
{
import(state, pos, *args[1], args[0], v);
}
});
static RegisterPrimOp primop_import({
.name = "import",
.args = {"path"},
.doc = R"(
Load, parse and return the Nix expression in the file *path*. If
*path* is a directory, the file ` default.nix ` in that directory
is loaded. Evaluation aborts if the file doesnt exist or contains
an incorrect Nix expression. `import` implements Nixs module
system: you can put any Nix expression (such as a set or a
function) in a separate file, and use it from Nix expressions in
other files.
> **Note**
>
> Unlike some languages, `import` is a regular function in Nix.
> Paths using the angle bracket syntax (e.g., `import` *\<foo\>*)
> are [normal path values](language-values.md).
A Nix expression loaded by `import` must not contain any *free
variables* (identifiers that are not defined in the Nix expression
itself and are not built-in). Therefore, it cannot refer to
variables that are in scope at the call site. For instance, if you
have a calling expression
```nix
rec {
x = 123;
y = import ./foo.nix;
}
```
then the following `foo.nix` will give an error:
```nix
x + 456
```
since `x` is not in scope in `foo.nix`. If you want `x` to be
available in `foo.nix`, you should pass it as a function argument:
```nix
rec {
x = 123;
y = import ./foo.nix x;
}
```
and
```nix
x: x + 456
```
(The function argument doesnt have to be called `x` in `foo.nix`;
any name would work.)
)",
.fun = [](EvalState & state, const Pos & pos, Value * * args, Value & v)
{
import(state, pos, *args[0], nullptr, v);
}
});
Add primop ‘scopedImport’ ‘scopedImport’ works like ‘import’, except that it takes a set of attributes to be added to the lexical scope of the expression, essentially extending or overriding the builtin variables. For instance, the expression scopedImport { x = 1; } ./foo.nix where foo.nix contains ‘x’, will evaluate to 1. This has a few applications: * It allows getting rid of function argument specifications in package expressions. For instance, a package expression like: { stdenv, fetchurl, libfoo }: stdenv.mkDerivation { ... buildInputs = [ libfoo ]; } can now we written as just stdenv.mkDerivation { ... buildInputs = [ libfoo ]; } and imported in all-packages.nix as: bar = scopedImport pkgs ./bar.nix; So whereas we once had dependencies listed in three places (buildInputs, the function, and the call site), they now only need to appear in one place. * It allows overriding builtin functions. For instance, to trace all calls to ‘map’: let overrides = { map = f: xs: builtins.trace "map called!" (map f xs); # Ensure that our override gets propagated by calls to # import/scopedImport. import = fn: scopedImport overrides fn; scopedImport = attrs: fn: scopedImport (overrides // attrs) fn; # Also update ‘builtins’. builtins = builtins // overrides; }; in scopedImport overrides ./bla.nix * Similarly, it allows extending the set of builtin functions. For instance, during Nixpkgs/NixOS evaluation, the Nixpkgs library functions could be added to the default scope. There is a downside: calls to scopedImport are not memoized, unlike import. So importing a file multiple times leads to multiple parsings / evaluations. It would be possible to construct the AST only once, but that would require careful handling of variables/environments.
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/* Want reasonable symbol names, so extern C */
/* !!! Should we pass the Pos or the file name too? */
extern "C" typedef void (*ValueInitializer)(EvalState & state, Value & v);
/* Load a ValueInitializer from a DSO and return whatever it initializes */
void prim_importNative(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
PathSet context;
Path path = state.coerceToPath(pos, *args[0], context);
try {
state.realiseContext(context);
} catch (InvalidPathError & e) {
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
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.msg = hintfmt(
"cannot import '%1%', since path '%2%' is not valid",
path, e.path),
.errPos = pos
});
}
path = state.checkSourcePath(path);
string sym = state.forceStringNoCtx(*args[1], pos);
void *handle = dlopen(path.c_str(), RTLD_LAZY | RTLD_LOCAL);
if (!handle)
throw EvalError("could not open '%1%': %2%", path, dlerror());
dlerror();
ValueInitializer func = (ValueInitializer) dlsym(handle, sym.c_str());
if(!func) {
char *message = dlerror();
if (message)
throw EvalError("could not load symbol '%1%' from '%2%': %3%", sym, path, message);
else
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throw EvalError("symbol '%1%' from '%2%' resolved to NULL when a function pointer was expected",
sym, path);
}
(func)(state, v);
/* We don't dlclose because v may be a primop referencing a function in the shared object file */
}
/* Execute a program and parse its output */
void prim_exec(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceList(*args[0], pos);
auto elems = args[0]->listElems();
auto count = args[0]->listSize();
if (count == 0) {
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
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.msg = hintfmt("at least one argument to 'exec' required"),
.errPos = pos
});
}
PathSet context;
auto program = state.coerceToString(pos, *elems[0], context, false, false);
Strings commandArgs;
for (unsigned int i = 1; i < args[0]->listSize(); ++i) {
commandArgs.emplace_back(state.coerceToString(pos, *elems[i], context, false, false));
}
try {
state.realiseContext(context);
} catch (InvalidPathError & e) {
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("cannot execute '%1%', since path '%2%' is not valid",
program, e.path),
.errPos = pos
});
}
auto output = runProgram(program, true, commandArgs);
Expr * parsed;
try {
parsed = state.parseExprFromString(output, pos.file);
} catch (Error & e) {
2020-06-24 19:46:25 +00:00
e.addTrace(pos, "While parsing the output from '%1%'", program);
throw;
}
try {
state.eval(parsed, v);
} catch (Error & e) {
2020-06-24 19:46:25 +00:00
e.addTrace(pos, "While evaluating the output from '%1%'", program);
throw;
}
}
/* Return a string representing the type of the expression. */
static void prim_typeOf(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceValue(*args[0], pos);
string t;
switch (args[0]->type()) {
case nInt: t = "int"; break;
case nBool: t = "bool"; break;
case nString: t = "string"; break;
case nPath: t = "path"; break;
case nNull: t = "null"; break;
case nAttrs: t = "set"; break;
case nList: t = "list"; break;
case nFunction: t = "lambda"; break;
case nExternal:
t = args[0]->external->typeOf();
break;
case nFloat: t = "float"; break;
case nThunk: abort();
}
mkString(v, state.symbols.create(t));
}
static RegisterPrimOp primop_typeOf({
.name = "__typeOf",
.args = {"e"},
.doc = R"(
Return a string representing the type of the value *e*, namely
`"int"`, `"bool"`, `"string"`, `"path"`, `"null"`, `"set"`,
`"list"`, `"lambda"` or `"float"`.
)",
.fun = prim_typeOf,
});
2007-01-29 15:11:32 +00:00
/* Determine whether the argument is the null value. */
static void prim_isNull(EvalState & state, const Pos & pos, Value * * args, Value & v)
2007-01-29 15:11:32 +00:00
{
state.forceValue(*args[0], pos);
mkBool(v, args[0]->type() == nNull);
2007-01-29 15:11:32 +00:00
}
static RegisterPrimOp primop_isNull({
.name = "isNull",
.args = {"e"},
.doc = R"(
Return `true` if *e* evaluates to `null`, and `false` otherwise.
> **Warning**
>
> This function is *deprecated*; just write `e == null` instead.
)",
.fun = prim_isNull,
});
2007-01-29 15:11:32 +00:00
/* Determine whether the argument is a function. */
static void prim_isFunction(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceValue(*args[0], pos);
mkBool(v, args[0]->type() == nFunction);
}
static RegisterPrimOp primop_isFunction({
.name = "__isFunction",
.args = {"e"},
.doc = R"(
Return `true` if *e* evaluates to a function, and `false` otherwise.
)",
.fun = prim_isFunction,
});
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/* Determine whether the argument is an integer. */
static void prim_isInt(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceValue(*args[0], pos);
mkBool(v, args[0]->type() == nInt);
}
static RegisterPrimOp primop_isInt({
.name = "__isInt",
.args = {"e"},
.doc = R"(
Return `true` if *e* evaluates to an integer, and `false` otherwise.
)",
.fun = prim_isInt,
});
/* Determine whether the argument is a float. */
static void prim_isFloat(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceValue(*args[0], pos);
mkBool(v, args[0]->type() == nFloat);
}
2010-03-30 22:39:48 +00:00
static RegisterPrimOp primop_isFloat({
.name = "__isFloat",
.args = {"e"},
.doc = R"(
Return `true` if *e* evaluates to a float, and `false` otherwise.
)",
.fun = prim_isFloat,
});
/* Determine whether the argument is a string. */
static void prim_isString(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceValue(*args[0], pos);
mkBool(v, args[0]->type() == nString);
}
static RegisterPrimOp primop_isString({
.name = "__isString",
.args = {"e"},
.doc = R"(
Return `true` if *e* evaluates to a string, and `false` otherwise.
)",
.fun = prim_isString,
});
2010-03-30 22:39:48 +00:00
/* Determine whether the argument is a Boolean. */
static void prim_isBool(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceValue(*args[0], pos);
mkBool(v, args[0]->type() == nBool);
}
static RegisterPrimOp primop_isBool({
.name = "__isBool",
.args = {"e"},
.doc = R"(
Return `true` if *e* evaluates to a bool, and `false` otherwise.
)",
.fun = prim_isBool,
});
/* Determine whether the argument is a path. */
static void prim_isPath(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceValue(*args[0], pos);
mkBool(v, args[0]->type() == nPath);
}
2010-03-30 22:39:48 +00:00
static RegisterPrimOp primop_isPath({
.name = "__isPath",
.args = {"e"},
.doc = R"(
Return `true` if *e* evaluates to a path, and `false` otherwise.
)",
.fun = prim_isPath,
});
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struct CompareValues
{
bool operator () (const Value * v1, const Value * v2) const
2010-04-21 15:57:11 +00:00
{
if (v1->type() == nFloat && v2->type() == nInt)
return v1->fpoint < v2->integer;
if (v1->type() == nInt && v2->type() == nFloat)
return v1->integer < v2->fpoint;
if (v1->type() != v2->type())
throw EvalError("cannot compare %1% with %2%", showType(*v1), showType(*v2));
switch (v1->type()) {
case nInt:
return v1->integer < v2->integer;
case nFloat:
return v1->fpoint < v2->fpoint;
case nString:
return strcmp(v1->string.s, v2->string.s) < 0;
case nPath:
return strcmp(v1->path, v2->path) < 0;
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default:
throw EvalError("cannot compare %1% with %2%", showType(*v1), showType(*v2));
2010-04-21 15:57:11 +00:00
}
}
};
#if HAVE_BOEHMGC
typedef list<Value *, gc_allocator<Value *> > ValueList;
#else
typedef list<Value *> ValueList;
#endif
2021-04-13 21:08:59 +00:00
static Bindings::iterator getAttr(
EvalState & state,
string funcName,
string attrName,
Bindings * attrSet,
const Pos & pos)
{
Bindings::iterator value = attrSet->find(state.symbols.create(attrName));
if (value == attrSet->end()) {
hintformat errorMsg = hintfmt(
"attribute '%s' missing for call to '%s'",
attrName,
funcName
);
Pos aPos = *attrSet->pos;
if (aPos == noPos) {
throw TypeError({
.msg = errorMsg,
.errPos = pos,
});
} else {
auto e = TypeError({
.msg = errorMsg,
.errPos = aPos,
});
// Adding another trace for the function name to make it clear
// which call received wrong arguments.
e.addTrace(pos, hintfmt("while invoking '%s'", funcName));
throw e;
}
}
return value;
}
static void prim_genericClosure(EvalState & state, const Pos & pos, Value * * args, Value & v)
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{
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state.forceAttrs(*args[0], pos);
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/* Get the start set. */
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Bindings::iterator startSet = getAttr(
state,
"genericClosure",
"startSet",
args[0]->attrs,
pos
);
2014-04-04 17:05:36 +00:00
state.forceList(*startSet->value, pos);
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ValueList workSet;
for (unsigned int n = 0; n < startSet->value->listSize(); ++n)
workSet.push_back(startSet->value->listElems()[n]);
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/* Get the operator. */
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Bindings::iterator op = getAttr(
state,
"genericClosure",
"operator",
args[0]->attrs,
pos
);
state.forceValue(*op->value, pos);
2010-04-21 15:57:11 +00:00
/* Construct the closure by applying the operator to element of
`workSet', adding the result to `workSet', continuing until
no new elements are found. */
ValueList res;
// `doneKeys' doesn't need to be a GC root, because its values are
// reachable from res.
set<Value *, CompareValues> doneKeys;
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while (!workSet.empty()) {
Value * e = *(workSet.begin());
workSet.pop_front();
2007-01-29 15:11:32 +00:00
2014-04-04 17:11:40 +00:00
state.forceAttrs(*e, pos);
2007-01-29 15:11:32 +00:00
2010-04-21 15:57:11 +00:00
Bindings::iterator key =
e->attrs->find(state.symbols.create("key"));
if (key == e->attrs->end())
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("attribute 'key' required"),
.errPos = pos
});
state.forceValue(*key->value, pos);
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if (!doneKeys.insert(key->value).second) continue;
res.push_back(e);
2013-09-02 14:29:15 +00:00
/* Call the `operator' function with `e' as argument. */
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Value call;
mkApp(call, *op->value, *e);
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state.forceList(call, pos);
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/* Add the values returned by the operator to the work set. */
for (unsigned int n = 0; n < call.listSize(); ++n) {
state.forceValue(*call.listElems()[n], pos);
workSet.push_back(call.listElems()[n]);
2010-04-21 15:57:11 +00:00
}
2007-01-29 15:11:32 +00:00
}
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/* Create the result list. */
state.mkList(v, res.size());
unsigned int n = 0;
2015-07-17 17:24:28 +00:00
for (auto & i : res)
v.listElems()[n++] = i;
2007-01-29 15:11:32 +00:00
}
static RegisterPrimOp primop_genericClosure(RegisterPrimOp::Info {
.name = "__genericClosure",
.arity = 1,
.fun = prim_genericClosure,
});
2007-01-29 15:11:32 +00:00
static RegisterPrimOp primop_abort({
.name = "abort",
.args = {"s"},
.doc = R"(
Abort Nix expression evaluation and print the error message *s*.
)",
.fun = [](EvalState & state, const Pos & pos, Value * * args, Value & v)
{
PathSet context;
string s = state.coerceToString(pos, *args[0], context);
throw Abort("evaluation aborted with the following error message: '%1%'", s);
}
});
2007-01-29 15:11:32 +00:00
static RegisterPrimOp primop_throw({
.name = "throw",
.args = {"s"},
.doc = R"(
Throw an error message *s*. This usually aborts Nix expression
evaluation, but in `nix-env -qa` and other commands that try to
evaluate a set of derivations to get information about those
derivations, a derivation that throws an error is silently skipped
(which is not the case for `abort`).
)",
.fun = [](EvalState & state, const Pos & pos, Value * * args, Value & v)
{
PathSet context;
string s = state.coerceToString(pos, *args[0], context);
throw ThrownError(s);
}
});
static void prim_addErrorContext(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
try {
state.forceValue(*args[1], pos);
2010-05-07 12:33:14 +00:00
v = *args[1];
} catch (Error & e) {
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PathSet context;
e.addTrace(std::nullopt, state.coerceToString(pos, *args[0], context));
throw;
}
}
static RegisterPrimOp primop_addErrorContext(RegisterPrimOp::Info {
.name = "__addErrorContext",
.arity = 2,
.fun = prim_addErrorContext,
});
2010-05-07 12:33:14 +00:00
static void prim_ceil(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
auto value = state.forceFloat(*args[0], args[0]->determinePos(pos));
mkInt(v, ceil(value));
}
static RegisterPrimOp primop_ceil({
.name = "__ceil",
.args = {"double"},
.doc = R"(
Converts an IEEE-754 double-precision floating-point number (*double*) to
the next higher integer.
If the datatype is neither an integer nor a "float", an evaluation error will be
thrown.
)",
.fun = prim_ceil,
});
static void prim_floor(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
auto value = state.forceFloat(*args[0], args[0]->determinePos(pos));
mkInt(v, floor(value));
}
static RegisterPrimOp primop_floor({
.name = "__floor",
.args = {"double"},
.doc = R"(
Converts an IEEE-754 double-precision floating-point number (*double*) to
the next lower integer.
If the datatype is neither an integer nor a "float", an evaluation error will be
thrown.
)",
.fun = prim_floor,
});
2013-09-02 14:29:15 +00:00
/* Try evaluating the argument. Success => {success=true; value=something;},
* else => {success=false; value=false;} */
static void prim_tryEval(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.mkAttrs(v, 2);
try {
state.forceValue(*args[0], pos);
2013-10-28 06:34:44 +00:00
v.attrs->push_back(Attr(state.sValue, args[0]));
mkBool(*state.allocAttr(v, state.symbols.create("success")), true);
} catch (AssertionError & e) {
2013-10-28 06:34:44 +00:00
mkBool(*state.allocAttr(v, state.sValue), false);
mkBool(*state.allocAttr(v, state.symbols.create("success")), false);
}
v.attrs->sort();
}
static RegisterPrimOp primop_tryEval({
.name = "__tryEval",
.args = {"e"},
.doc = R"(
Try to shallowly evaluate *e*. Return a set containing the
attributes `success` (`true` if *e* evaluated successfully,
`false` if an error was thrown) and `value`, equalling *e* if
successful and `false` otherwise. `tryEval` will only prevent
errors created by `throw` or `assert` from being thrown.
Errors `tryEval` will not catch are for example those created
by `abort` and type errors generated by builtins. Also note that
this doesn't evaluate *e* deeply, so `let e = { x = throw ""; };
in (builtins.tryEval e).success` will be `true`. Using
`builtins.deepSeq` one can get the expected result:
`let e = { x = throw ""; }; in
(builtins.tryEval (builtins.deepSeq e e)).success` will be
`false`.
)",
.fun = prim_tryEval,
});
2007-01-29 15:11:32 +00:00
/* Return an environment variable. Use with care. */
static void prim_getEnv(EvalState & state, const Pos & pos, Value * * args, Value & v)
2007-01-29 15:11:32 +00:00
{
2014-04-04 19:14:11 +00:00
string name = state.forceStringNoCtx(*args[0], pos);
mkString(v, evalSettings.restrictEval || evalSettings.pureEval ? "" : getEnv(name).value_or(""));
2007-01-29 15:11:32 +00:00
}
static RegisterPrimOp primop_getEnv({
.name = "__getEnv",
.args = {"s"},
.doc = R"(
`getEnv` returns the value of the environment variable *s*, or an
empty string if the variable doesnt exist. This function should be
used with care, as it can introduce all sorts of nasty environment
dependencies in your Nix expression.
`getEnv` is used in Nix Packages to locate the file
`~/.nixpkgs/config.nix`, which contains user-local settings for Nix
Packages. (That is, it does a `getEnv "HOME"` to locate the users
home directory.)
)",
.fun = prim_getEnv,
});
2014-09-22 12:53:21 +00:00
/* Evaluate the first argument, then return the second argument. */
2014-09-23 13:08:27 +00:00
static void prim_seq(EvalState & state, const Pos & pos, Value * * args, Value & v)
2014-09-22 12:53:21 +00:00
{
state.forceValue(*args[0], pos);
state.forceValue(*args[1], pos);
2014-09-22 12:53:21 +00:00
v = *args[1];
}
static RegisterPrimOp primop_seq({
.name = "__seq",
.args = {"e1", "e2"},
.doc = R"(
Evaluate *e1*, then evaluate and return *e2*. This ensures that a
computation is strict in the value of *e1*.
)",
.fun = prim_seq,
});
2014-09-22 12:53:21 +00:00
/* Evaluate the first argument deeply (i.e. recursing into lists and
attrsets), then return the second argument. */
2014-09-23 13:08:27 +00:00
static void prim_deepSeq(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceValueDeep(*args[0]);
state.forceValue(*args[1], pos);
v = *args[1];
}
static RegisterPrimOp primop_deepSeq({
.name = "__deepSeq",
.args = {"e1", "e2"},
.doc = R"(
This is like `seq e1 e2`, except that *e1* is evaluated *deeply*:
if its a list or set, its elements or attributes are also
evaluated recursively.
)",
.fun = prim_deepSeq,
});
/* Evaluate the first expression and print it on standard error. Then
return the second expression. Useful for debugging. */
static void prim_trace(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceValue(*args[0], pos);
if (args[0]->type() == nString)
printError("trace: %1%", args[0]->string.s);
else
printError("trace: %1%", *args[0]);
state.forceValue(*args[1], pos);
v = *args[1];
}
2007-01-29 15:11:32 +00:00
static RegisterPrimOp primop_trace({
.name = "__trace",
.args = {"e1", "e2"},
.doc = R"(
Evaluate *e1* and print its abstract syntax representation on
standard error. Then return *e2*. This function is useful for
debugging.
)",
.fun = prim_trace,
});
2007-01-29 15:11:32 +00:00
/*************************************************************
* Derivations
*************************************************************/
/* Construct (as a unobservable side effect) a Nix derivation
expression that performs the derivation described by the argument
set. Returns the original set extended with the following
attributes: `outPath' containing the primary output path of the
derivation; `drvPath' containing the path of the Nix expression;
and `type' set to `derivation' to indicate that this is a
derivation. */
static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
2014-04-04 17:11:40 +00:00
state.forceAttrs(*args[0], pos);
2010-03-31 15:38:03 +00:00
/* Figure out the name first (for stack backtraces). */
2021-04-13 21:08:59 +00:00
Bindings::iterator attr = getAttr(
state,
"derivationStrict",
state.sName,
args[0]->attrs,
pos
);
2006-10-23 16:45:19 +00:00
string drvName;
Pos & posDrvName(*attr->pos);
try {
2014-04-04 19:14:11 +00:00
drvName = state.forceStringNoCtx(*attr->value, pos);
2006-10-23 16:45:19 +00:00
} catch (Error & e) {
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e.addTrace(posDrvName, "while evaluating the derivation attribute 'name'");
2006-10-23 16:45:19 +00:00
throw;
}
Add support for passing structured data to builders Previously, all derivation attributes had to be coerced into strings so that they could be passed via the environment. This is lossy (e.g. lists get flattened, necessitating configureFlags vs. configureFlagsArray, of which the latter cannot be specified as an attribute), doesn't support attribute sets at all, and has size limitations (necessitating hacks like passAsFile). This patch adds a new mode for passing attributes to builders, namely encoded as a JSON file ".attrs.json" in the current directory of the builder. This mode is activated via the special attribute __structuredAttrs = true; (The idea is that one day we can set this in stdenv.mkDerivation.) For example, stdenv.mkDerivation { __structuredAttrs = true; name = "foo"; buildInputs = [ pkgs.hello pkgs.cowsay ]; doCheck = true; hardening.format = false; } results in a ".attrs.json" file containing (sans the indentation): { "buildInputs": [], "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash", "configureFlags": [ "--with-foo", "--with-bar=1 2" ], "doCheck": true, "hardening": { "format": false }, "name": "foo", "nativeBuildInputs": [ "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10", "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03" ], "propagatedBuildInputs": [], "propagatedNativeBuildInputs": [], "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv", "system": "x86_64-linux" } "passAsFile" is ignored in this mode because it's not needed - large strings are included directly in the JSON representation. It is up to the builder to do something with the JSON representation. For example, in bash-based builders, lists/attrsets of string values could be mapped to bash (associative) arrays.
2017-01-25 15:42:07 +00:00
/* Check whether attributes should be passed as a JSON file. */
std::ostringstream jsonBuf;
std::unique_ptr<JSONObject> jsonObject;
attr = args[0]->attrs->find(state.sStructuredAttrs);
if (attr != args[0]->attrs->end() && state.forceBool(*attr->value, pos))
jsonObject = std::make_unique<JSONObject>(jsonBuf);
/* Check whether null attributes should be ignored. */
bool ignoreNulls = false;
attr = args[0]->attrs->find(state.sIgnoreNulls);
if (attr != args[0]->attrs->end())
2016-08-29 15:56:35 +00:00
ignoreNulls = state.forceBool(*attr->value, pos);
/* Build the derivation expression by processing the attributes. */
Derivation drv;
2020-07-12 03:03:12 +00:00
drv.name = drvName;
PathSet context;
bool contentAddressed = false;
2019-02-12 12:43:32 +00:00
std::optional<std::string> outputHash;
std::string outputHashAlgo;
auto ingestionMethod = FileIngestionMethod::Flat;
* Support multiple outputs. A derivation can declare multiple outputs by setting the ‘outputs’ attribute. For example: stdenv.mkDerivation { name = "aterm-2.5"; src = ...; outputs = [ "out" "tools" "dev" ]; configureFlags = "--bindir=$(tools)/bin --includedir=$(dev)/include"; } This derivation creates three outputs, named like this: /nix/store/gcnqgllbh01p3d448q8q6pzn2nc2gpyl-aterm-2.5 /nix/store/gjf1sgirwfnrlr0bdxyrwzpw2r304j02-aterm-2.5-tools /nix/store/hp6108bqfgxvza25nnxfs7kj88xi2vdx-aterm-2.5-dev That is, the symbolic name of the output is suffixed to the store path (except for the ‘out’ output). Each path is passed to the builder through the corresponding environment variable, e.g., ${tools}. The main reason for multiple outputs is to allow parts of a package to be distributed and garbage-collected separately. For instance, most packages depend on Glibc for its libraries, but don't need its header files. If these are separated into different store paths, then a package that depends on the Glibc libraries only causes the libraries and not the headers to be downloaded. The main problem with multiple outputs is that if one output exists while the others have been garbage-collected (or never downloaded in the first place), and we want to rebuild the other outputs, then this isn't possible because we can't clobber a valid output (it might be in active use). This currently gives an error message like: error: derivation `/nix/store/1s9zw4c8qydpjyrayxamx2z7zzp5pcgh-aterm-2.5.drv' is blocked by its output paths There are two solutions: 1) Do the build in a chroot. Then we don't need to overwrite the existing path. 2) Use hash rewriting (see the ASE-2005 paper). Scary but it should work. This is not finished yet. There is not yet an easy way to refer to non-default outputs in Nix expressions. Also, mutually recursive outputs aren't detected yet and cause the garbage collector to crash.
2011-07-18 23:31:03 +00:00
StringSet outputs;
outputs.insert("out");
Add support for passing structured data to builders Previously, all derivation attributes had to be coerced into strings so that they could be passed via the environment. This is lossy (e.g. lists get flattened, necessitating configureFlags vs. configureFlagsArray, of which the latter cannot be specified as an attribute), doesn't support attribute sets at all, and has size limitations (necessitating hacks like passAsFile). This patch adds a new mode for passing attributes to builders, namely encoded as a JSON file ".attrs.json" in the current directory of the builder. This mode is activated via the special attribute __structuredAttrs = true; (The idea is that one day we can set this in stdenv.mkDerivation.) For example, stdenv.mkDerivation { __structuredAttrs = true; name = "foo"; buildInputs = [ pkgs.hello pkgs.cowsay ]; doCheck = true; hardening.format = false; } results in a ".attrs.json" file containing (sans the indentation): { "buildInputs": [], "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash", "configureFlags": [ "--with-foo", "--with-bar=1 2" ], "doCheck": true, "hardening": { "format": false }, "name": "foo", "nativeBuildInputs": [ "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10", "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03" ], "propagatedBuildInputs": [], "propagatedNativeBuildInputs": [], "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv", "system": "x86_64-linux" } "passAsFile" is ignored in this mode because it's not needed - large strings are included directly in the JSON representation. It is up to the builder to do something with the JSON representation. For example, in bash-based builders, lists/attrsets of string values could be mapped to bash (associative) arrays.
2017-01-25 15:42:07 +00:00
for (auto & i : args[0]->attrs->lexicographicOrder()) {
if (i->name == state.sIgnoreNulls) continue;
const string & key = i->name;
vomit("processing attribute '%1%'", key);
Add support for passing structured data to builders Previously, all derivation attributes had to be coerced into strings so that they could be passed via the environment. This is lossy (e.g. lists get flattened, necessitating configureFlags vs. configureFlagsArray, of which the latter cannot be specified as an attribute), doesn't support attribute sets at all, and has size limitations (necessitating hacks like passAsFile). This patch adds a new mode for passing attributes to builders, namely encoded as a JSON file ".attrs.json" in the current directory of the builder. This mode is activated via the special attribute __structuredAttrs = true; (The idea is that one day we can set this in stdenv.mkDerivation.) For example, stdenv.mkDerivation { __structuredAttrs = true; name = "foo"; buildInputs = [ pkgs.hello pkgs.cowsay ]; doCheck = true; hardening.format = false; } results in a ".attrs.json" file containing (sans the indentation): { "buildInputs": [], "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash", "configureFlags": [ "--with-foo", "--with-bar=1 2" ], "doCheck": true, "hardening": { "format": false }, "name": "foo", "nativeBuildInputs": [ "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10", "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03" ], "propagatedBuildInputs": [], "propagatedNativeBuildInputs": [], "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv", "system": "x86_64-linux" } "passAsFile" is ignored in this mode because it's not needed - large strings are included directly in the JSON representation. It is up to the builder to do something with the JSON representation. For example, in bash-based builders, lists/attrsets of string values could be mapped to bash (associative) arrays.
2017-01-25 15:42:07 +00:00
auto handleHashMode = [&](const std::string & s) {
if (s == "recursive") ingestionMethod = FileIngestionMethod::Recursive;
else if (s == "flat") ingestionMethod = FileIngestionMethod::Flat;
else
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("invalid value '%s' for 'outputHashMode' attribute", s),
.errPos = posDrvName
});
Add support for passing structured data to builders Previously, all derivation attributes had to be coerced into strings so that they could be passed via the environment. This is lossy (e.g. lists get flattened, necessitating configureFlags vs. configureFlagsArray, of which the latter cannot be specified as an attribute), doesn't support attribute sets at all, and has size limitations (necessitating hacks like passAsFile). This patch adds a new mode for passing attributes to builders, namely encoded as a JSON file ".attrs.json" in the current directory of the builder. This mode is activated via the special attribute __structuredAttrs = true; (The idea is that one day we can set this in stdenv.mkDerivation.) For example, stdenv.mkDerivation { __structuredAttrs = true; name = "foo"; buildInputs = [ pkgs.hello pkgs.cowsay ]; doCheck = true; hardening.format = false; } results in a ".attrs.json" file containing (sans the indentation): { "buildInputs": [], "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash", "configureFlags": [ "--with-foo", "--with-bar=1 2" ], "doCheck": true, "hardening": { "format": false }, "name": "foo", "nativeBuildInputs": [ "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10", "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03" ], "propagatedBuildInputs": [], "propagatedNativeBuildInputs": [], "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv", "system": "x86_64-linux" } "passAsFile" is ignored in this mode because it's not needed - large strings are included directly in the JSON representation. It is up to the builder to do something with the JSON representation. For example, in bash-based builders, lists/attrsets of string values could be mapped to bash (associative) arrays.
2017-01-25 15:42:07 +00:00
};
auto handleOutputs = [&](const Strings & ss) {
outputs.clear();
for (auto & j : ss) {
if (outputs.find(j) != outputs.end())
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("duplicate derivation output '%1%'", j),
.errPos = posDrvName
});
Add support for passing structured data to builders Previously, all derivation attributes had to be coerced into strings so that they could be passed via the environment. This is lossy (e.g. lists get flattened, necessitating configureFlags vs. configureFlagsArray, of which the latter cannot be specified as an attribute), doesn't support attribute sets at all, and has size limitations (necessitating hacks like passAsFile). This patch adds a new mode for passing attributes to builders, namely encoded as a JSON file ".attrs.json" in the current directory of the builder. This mode is activated via the special attribute __structuredAttrs = true; (The idea is that one day we can set this in stdenv.mkDerivation.) For example, stdenv.mkDerivation { __structuredAttrs = true; name = "foo"; buildInputs = [ pkgs.hello pkgs.cowsay ]; doCheck = true; hardening.format = false; } results in a ".attrs.json" file containing (sans the indentation): { "buildInputs": [], "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash", "configureFlags": [ "--with-foo", "--with-bar=1 2" ], "doCheck": true, "hardening": { "format": false }, "name": "foo", "nativeBuildInputs": [ "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10", "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03" ], "propagatedBuildInputs": [], "propagatedNativeBuildInputs": [], "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv", "system": "x86_64-linux" } "passAsFile" is ignored in this mode because it's not needed - large strings are included directly in the JSON representation. It is up to the builder to do something with the JSON representation. For example, in bash-based builders, lists/attrsets of string values could be mapped to bash (associative) arrays.
2017-01-25 15:42:07 +00:00
/* !!! Check whether j is a valid attribute
name. */
/* Derivations cannot be named drv, because
then we'd have an attribute drvPath in
the resulting set. */
if (j == "drv")
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("invalid derivation output name 'drv'" ),
.errPos = posDrvName
});
Add support for passing structured data to builders Previously, all derivation attributes had to be coerced into strings so that they could be passed via the environment. This is lossy (e.g. lists get flattened, necessitating configureFlags vs. configureFlagsArray, of which the latter cannot be specified as an attribute), doesn't support attribute sets at all, and has size limitations (necessitating hacks like passAsFile). This patch adds a new mode for passing attributes to builders, namely encoded as a JSON file ".attrs.json" in the current directory of the builder. This mode is activated via the special attribute __structuredAttrs = true; (The idea is that one day we can set this in stdenv.mkDerivation.) For example, stdenv.mkDerivation { __structuredAttrs = true; name = "foo"; buildInputs = [ pkgs.hello pkgs.cowsay ]; doCheck = true; hardening.format = false; } results in a ".attrs.json" file containing (sans the indentation): { "buildInputs": [], "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash", "configureFlags": [ "--with-foo", "--with-bar=1 2" ], "doCheck": true, "hardening": { "format": false }, "name": "foo", "nativeBuildInputs": [ "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10", "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03" ], "propagatedBuildInputs": [], "propagatedNativeBuildInputs": [], "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv", "system": "x86_64-linux" } "passAsFile" is ignored in this mode because it's not needed - large strings are included directly in the JSON representation. It is up to the builder to do something with the JSON representation. For example, in bash-based builders, lists/attrsets of string values could be mapped to bash (associative) arrays.
2017-01-25 15:42:07 +00:00
outputs.insert(j);
}
if (outputs.empty())
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("derivation cannot have an empty set of outputs"),
.errPos = posDrvName
});
Add support for passing structured data to builders Previously, all derivation attributes had to be coerced into strings so that they could be passed via the environment. This is lossy (e.g. lists get flattened, necessitating configureFlags vs. configureFlagsArray, of which the latter cannot be specified as an attribute), doesn't support attribute sets at all, and has size limitations (necessitating hacks like passAsFile). This patch adds a new mode for passing attributes to builders, namely encoded as a JSON file ".attrs.json" in the current directory of the builder. This mode is activated via the special attribute __structuredAttrs = true; (The idea is that one day we can set this in stdenv.mkDerivation.) For example, stdenv.mkDerivation { __structuredAttrs = true; name = "foo"; buildInputs = [ pkgs.hello pkgs.cowsay ]; doCheck = true; hardening.format = false; } results in a ".attrs.json" file containing (sans the indentation): { "buildInputs": [], "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash", "configureFlags": [ "--with-foo", "--with-bar=1 2" ], "doCheck": true, "hardening": { "format": false }, "name": "foo", "nativeBuildInputs": [ "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10", "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03" ], "propagatedBuildInputs": [], "propagatedNativeBuildInputs": [], "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv", "system": "x86_64-linux" } "passAsFile" is ignored in this mode because it's not needed - large strings are included directly in the JSON representation. It is up to the builder to do something with the JSON representation. For example, in bash-based builders, lists/attrsets of string values could be mapped to bash (associative) arrays.
2017-01-25 15:42:07 +00:00
};
try {
if (ignoreNulls) {
state.forceValue(*i->value, pos);
if (i->value->type() == nNull) continue;
}
if (i->name == state.sContentAddressed) {
settings.requireExperimentalFeature("ca-derivations");
contentAddressed = state.forceBool(*i->value, pos);
}
/* The `args' attribute is special: it supplies the
command-line arguments to the builder. */
else if (i->name == state.sArgs) {
Add support for passing structured data to builders Previously, all derivation attributes had to be coerced into strings so that they could be passed via the environment. This is lossy (e.g. lists get flattened, necessitating configureFlags vs. configureFlagsArray, of which the latter cannot be specified as an attribute), doesn't support attribute sets at all, and has size limitations (necessitating hacks like passAsFile). This patch adds a new mode for passing attributes to builders, namely encoded as a JSON file ".attrs.json" in the current directory of the builder. This mode is activated via the special attribute __structuredAttrs = true; (The idea is that one day we can set this in stdenv.mkDerivation.) For example, stdenv.mkDerivation { __structuredAttrs = true; name = "foo"; buildInputs = [ pkgs.hello pkgs.cowsay ]; doCheck = true; hardening.format = false; } results in a ".attrs.json" file containing (sans the indentation): { "buildInputs": [], "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash", "configureFlags": [ "--with-foo", "--with-bar=1 2" ], "doCheck": true, "hardening": { "format": false }, "name": "foo", "nativeBuildInputs": [ "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10", "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03" ], "propagatedBuildInputs": [], "propagatedNativeBuildInputs": [], "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv", "system": "x86_64-linux" } "passAsFile" is ignored in this mode because it's not needed - large strings are included directly in the JSON representation. It is up to the builder to do something with the JSON representation. For example, in bash-based builders, lists/attrsets of string values could be mapped to bash (associative) arrays.
2017-01-25 15:42:07 +00:00
state.forceList(*i->value, pos);
for (unsigned int n = 0; n < i->value->listSize(); ++n) {
string s = state.coerceToString(posDrvName, *i->value->listElems()[n], context, true);
drv.args.push_back(s);
}
}
/* All other attributes are passed to the builder through
the environment. */
else {
Add support for passing structured data to builders Previously, all derivation attributes had to be coerced into strings so that they could be passed via the environment. This is lossy (e.g. lists get flattened, necessitating configureFlags vs. configureFlagsArray, of which the latter cannot be specified as an attribute), doesn't support attribute sets at all, and has size limitations (necessitating hacks like passAsFile). This patch adds a new mode for passing attributes to builders, namely encoded as a JSON file ".attrs.json" in the current directory of the builder. This mode is activated via the special attribute __structuredAttrs = true; (The idea is that one day we can set this in stdenv.mkDerivation.) For example, stdenv.mkDerivation { __structuredAttrs = true; name = "foo"; buildInputs = [ pkgs.hello pkgs.cowsay ]; doCheck = true; hardening.format = false; } results in a ".attrs.json" file containing (sans the indentation): { "buildInputs": [], "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash", "configureFlags": [ "--with-foo", "--with-bar=1 2" ], "doCheck": true, "hardening": { "format": false }, "name": "foo", "nativeBuildInputs": [ "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10", "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03" ], "propagatedBuildInputs": [], "propagatedNativeBuildInputs": [], "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv", "system": "x86_64-linux" } "passAsFile" is ignored in this mode because it's not needed - large strings are included directly in the JSON representation. It is up to the builder to do something with the JSON representation. For example, in bash-based builders, lists/attrsets of string values could be mapped to bash (associative) arrays.
2017-01-25 15:42:07 +00:00
if (jsonObject) {
if (i->name == state.sStructuredAttrs) continue;
auto placeholder(jsonObject->placeholder(key));
printValueAsJSON(state, true, *i->value, placeholder, context);
if (i->name == state.sBuilder)
drv.builder = state.forceString(*i->value, context, posDrvName);
else if (i->name == state.sSystem)
drv.platform = state.forceStringNoCtx(*i->value, posDrvName);
else if (i->name == state.sOutputHash)
Add support for passing structured data to builders Previously, all derivation attributes had to be coerced into strings so that they could be passed via the environment. This is lossy (e.g. lists get flattened, necessitating configureFlags vs. configureFlagsArray, of which the latter cannot be specified as an attribute), doesn't support attribute sets at all, and has size limitations (necessitating hacks like passAsFile). This patch adds a new mode for passing attributes to builders, namely encoded as a JSON file ".attrs.json" in the current directory of the builder. This mode is activated via the special attribute __structuredAttrs = true; (The idea is that one day we can set this in stdenv.mkDerivation.) For example, stdenv.mkDerivation { __structuredAttrs = true; name = "foo"; buildInputs = [ pkgs.hello pkgs.cowsay ]; doCheck = true; hardening.format = false; } results in a ".attrs.json" file containing (sans the indentation): { "buildInputs": [], "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash", "configureFlags": [ "--with-foo", "--with-bar=1 2" ], "doCheck": true, "hardening": { "format": false }, "name": "foo", "nativeBuildInputs": [ "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10", "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03" ], "propagatedBuildInputs": [], "propagatedNativeBuildInputs": [], "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv", "system": "x86_64-linux" } "passAsFile" is ignored in this mode because it's not needed - large strings are included directly in the JSON representation. It is up to the builder to do something with the JSON representation. For example, in bash-based builders, lists/attrsets of string values could be mapped to bash (associative) arrays.
2017-01-25 15:42:07 +00:00
outputHash = state.forceStringNoCtx(*i->value, posDrvName);
else if (i->name == state.sOutputHashAlgo)
Add support for passing structured data to builders Previously, all derivation attributes had to be coerced into strings so that they could be passed via the environment. This is lossy (e.g. lists get flattened, necessitating configureFlags vs. configureFlagsArray, of which the latter cannot be specified as an attribute), doesn't support attribute sets at all, and has size limitations (necessitating hacks like passAsFile). This patch adds a new mode for passing attributes to builders, namely encoded as a JSON file ".attrs.json" in the current directory of the builder. This mode is activated via the special attribute __structuredAttrs = true; (The idea is that one day we can set this in stdenv.mkDerivation.) For example, stdenv.mkDerivation { __structuredAttrs = true; name = "foo"; buildInputs = [ pkgs.hello pkgs.cowsay ]; doCheck = true; hardening.format = false; } results in a ".attrs.json" file containing (sans the indentation): { "buildInputs": [], "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash", "configureFlags": [ "--with-foo", "--with-bar=1 2" ], "doCheck": true, "hardening": { "format": false }, "name": "foo", "nativeBuildInputs": [ "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10", "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03" ], "propagatedBuildInputs": [], "propagatedNativeBuildInputs": [], "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv", "system": "x86_64-linux" } "passAsFile" is ignored in this mode because it's not needed - large strings are included directly in the JSON representation. It is up to the builder to do something with the JSON representation. For example, in bash-based builders, lists/attrsets of string values could be mapped to bash (associative) arrays.
2017-01-25 15:42:07 +00:00
outputHashAlgo = state.forceStringNoCtx(*i->value, posDrvName);
else if (i->name == state.sOutputHashMode)
Add support for passing structured data to builders Previously, all derivation attributes had to be coerced into strings so that they could be passed via the environment. This is lossy (e.g. lists get flattened, necessitating configureFlags vs. configureFlagsArray, of which the latter cannot be specified as an attribute), doesn't support attribute sets at all, and has size limitations (necessitating hacks like passAsFile). This patch adds a new mode for passing attributes to builders, namely encoded as a JSON file ".attrs.json" in the current directory of the builder. This mode is activated via the special attribute __structuredAttrs = true; (The idea is that one day we can set this in stdenv.mkDerivation.) For example, stdenv.mkDerivation { __structuredAttrs = true; name = "foo"; buildInputs = [ pkgs.hello pkgs.cowsay ]; doCheck = true; hardening.format = false; } results in a ".attrs.json" file containing (sans the indentation): { "buildInputs": [], "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash", "configureFlags": [ "--with-foo", "--with-bar=1 2" ], "doCheck": true, "hardening": { "format": false }, "name": "foo", "nativeBuildInputs": [ "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10", "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03" ], "propagatedBuildInputs": [], "propagatedNativeBuildInputs": [], "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv", "system": "x86_64-linux" } "passAsFile" is ignored in this mode because it's not needed - large strings are included directly in the JSON representation. It is up to the builder to do something with the JSON representation. For example, in bash-based builders, lists/attrsets of string values could be mapped to bash (associative) arrays.
2017-01-25 15:42:07 +00:00
handleHashMode(state.forceStringNoCtx(*i->value, posDrvName));
else if (i->name == state.sOutputs) {
Add support for passing structured data to builders Previously, all derivation attributes had to be coerced into strings so that they could be passed via the environment. This is lossy (e.g. lists get flattened, necessitating configureFlags vs. configureFlagsArray, of which the latter cannot be specified as an attribute), doesn't support attribute sets at all, and has size limitations (necessitating hacks like passAsFile). This patch adds a new mode for passing attributes to builders, namely encoded as a JSON file ".attrs.json" in the current directory of the builder. This mode is activated via the special attribute __structuredAttrs = true; (The idea is that one day we can set this in stdenv.mkDerivation.) For example, stdenv.mkDerivation { __structuredAttrs = true; name = "foo"; buildInputs = [ pkgs.hello pkgs.cowsay ]; doCheck = true; hardening.format = false; } results in a ".attrs.json" file containing (sans the indentation): { "buildInputs": [], "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash", "configureFlags": [ "--with-foo", "--with-bar=1 2" ], "doCheck": true, "hardening": { "format": false }, "name": "foo", "nativeBuildInputs": [ "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10", "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03" ], "propagatedBuildInputs": [], "propagatedNativeBuildInputs": [], "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv", "system": "x86_64-linux" } "passAsFile" is ignored in this mode because it's not needed - large strings are included directly in the JSON representation. It is up to the builder to do something with the JSON representation. For example, in bash-based builders, lists/attrsets of string values could be mapped to bash (associative) arrays.
2017-01-25 15:42:07 +00:00
/* Require outputs to be a list of strings. */
state.forceList(*i->value, posDrvName);
Strings ss;
for (unsigned int n = 0; n < i->value->listSize(); ++n)
ss.emplace_back(state.forceStringNoCtx(*i->value->listElems()[n], posDrvName));
handleOutputs(ss);
* Support multiple outputs. A derivation can declare multiple outputs by setting the ‘outputs’ attribute. For example: stdenv.mkDerivation { name = "aterm-2.5"; src = ...; outputs = [ "out" "tools" "dev" ]; configureFlags = "--bindir=$(tools)/bin --includedir=$(dev)/include"; } This derivation creates three outputs, named like this: /nix/store/gcnqgllbh01p3d448q8q6pzn2nc2gpyl-aterm-2.5 /nix/store/gjf1sgirwfnrlr0bdxyrwzpw2r304j02-aterm-2.5-tools /nix/store/hp6108bqfgxvza25nnxfs7kj88xi2vdx-aterm-2.5-dev That is, the symbolic name of the output is suffixed to the store path (except for the ‘out’ output). Each path is passed to the builder through the corresponding environment variable, e.g., ${tools}. The main reason for multiple outputs is to allow parts of a package to be distributed and garbage-collected separately. For instance, most packages depend on Glibc for its libraries, but don't need its header files. If these are separated into different store paths, then a package that depends on the Glibc libraries only causes the libraries and not the headers to be downloaded. The main problem with multiple outputs is that if one output exists while the others have been garbage-collected (or never downloaded in the first place), and we want to rebuild the other outputs, then this isn't possible because we can't clobber a valid output (it might be in active use). This currently gives an error message like: error: derivation `/nix/store/1s9zw4c8qydpjyrayxamx2z7zzp5pcgh-aterm-2.5.drv' is blocked by its output paths There are two solutions: 1) Do the build in a chroot. Then we don't need to overwrite the existing path. 2) Use hash rewriting (see the ASE-2005 paper). Scary but it should work. This is not finished yet. There is not yet an easy way to refer to non-default outputs in Nix expressions. Also, mutually recursive outputs aren't detected yet and cause the garbage collector to crash.
2011-07-18 23:31:03 +00:00
}
Add support for passing structured data to builders Previously, all derivation attributes had to be coerced into strings so that they could be passed via the environment. This is lossy (e.g. lists get flattened, necessitating configureFlags vs. configureFlagsArray, of which the latter cannot be specified as an attribute), doesn't support attribute sets at all, and has size limitations (necessitating hacks like passAsFile). This patch adds a new mode for passing attributes to builders, namely encoded as a JSON file ".attrs.json" in the current directory of the builder. This mode is activated via the special attribute __structuredAttrs = true; (The idea is that one day we can set this in stdenv.mkDerivation.) For example, stdenv.mkDerivation { __structuredAttrs = true; name = "foo"; buildInputs = [ pkgs.hello pkgs.cowsay ]; doCheck = true; hardening.format = false; } results in a ".attrs.json" file containing (sans the indentation): { "buildInputs": [], "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash", "configureFlags": [ "--with-foo", "--with-bar=1 2" ], "doCheck": true, "hardening": { "format": false }, "name": "foo", "nativeBuildInputs": [ "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10", "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03" ], "propagatedBuildInputs": [], "propagatedNativeBuildInputs": [], "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv", "system": "x86_64-linux" } "passAsFile" is ignored in this mode because it's not needed - large strings are included directly in the JSON representation. It is up to the builder to do something with the JSON representation. For example, in bash-based builders, lists/attrsets of string values could be mapped to bash (associative) arrays.
2017-01-25 15:42:07 +00:00
} else {
auto s = state.coerceToString(*i->pos, *i->value, context, true);
Add support for passing structured data to builders Previously, all derivation attributes had to be coerced into strings so that they could be passed via the environment. This is lossy (e.g. lists get flattened, necessitating configureFlags vs. configureFlagsArray, of which the latter cannot be specified as an attribute), doesn't support attribute sets at all, and has size limitations (necessitating hacks like passAsFile). This patch adds a new mode for passing attributes to builders, namely encoded as a JSON file ".attrs.json" in the current directory of the builder. This mode is activated via the special attribute __structuredAttrs = true; (The idea is that one day we can set this in stdenv.mkDerivation.) For example, stdenv.mkDerivation { __structuredAttrs = true; name = "foo"; buildInputs = [ pkgs.hello pkgs.cowsay ]; doCheck = true; hardening.format = false; } results in a ".attrs.json" file containing (sans the indentation): { "buildInputs": [], "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash", "configureFlags": [ "--with-foo", "--with-bar=1 2" ], "doCheck": true, "hardening": { "format": false }, "name": "foo", "nativeBuildInputs": [ "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10", "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03" ], "propagatedBuildInputs": [], "propagatedNativeBuildInputs": [], "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv", "system": "x86_64-linux" } "passAsFile" is ignored in this mode because it's not needed - large strings are included directly in the JSON representation. It is up to the builder to do something with the JSON representation. For example, in bash-based builders, lists/attrsets of string values could be mapped to bash (associative) arrays.
2017-01-25 15:42:07 +00:00
drv.env.emplace(key, s);
if (i->name == state.sBuilder) drv.builder = s;
else if (i->name == state.sSystem) drv.platform = s;
else if (i->name == state.sOutputHash) outputHash = s;
else if (i->name == state.sOutputHashAlgo) outputHashAlgo = s;
else if (i->name == state.sOutputHashMode) handleHashMode(s);
else if (i->name == state.sOutputs)
Add support for passing structured data to builders Previously, all derivation attributes had to be coerced into strings so that they could be passed via the environment. This is lossy (e.g. lists get flattened, necessitating configureFlags vs. configureFlagsArray, of which the latter cannot be specified as an attribute), doesn't support attribute sets at all, and has size limitations (necessitating hacks like passAsFile). This patch adds a new mode for passing attributes to builders, namely encoded as a JSON file ".attrs.json" in the current directory of the builder. This mode is activated via the special attribute __structuredAttrs = true; (The idea is that one day we can set this in stdenv.mkDerivation.) For example, stdenv.mkDerivation { __structuredAttrs = true; name = "foo"; buildInputs = [ pkgs.hello pkgs.cowsay ]; doCheck = true; hardening.format = false; } results in a ".attrs.json" file containing (sans the indentation): { "buildInputs": [], "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash", "configureFlags": [ "--with-foo", "--with-bar=1 2" ], "doCheck": true, "hardening": { "format": false }, "name": "foo", "nativeBuildInputs": [ "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10", "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03" ], "propagatedBuildInputs": [], "propagatedNativeBuildInputs": [], "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv", "system": "x86_64-linux" } "passAsFile" is ignored in this mode because it's not needed - large strings are included directly in the JSON representation. It is up to the builder to do something with the JSON representation. For example, in bash-based builders, lists/attrsets of string values could be mapped to bash (associative) arrays.
2017-01-25 15:42:07 +00:00
handleOutputs(tokenizeString<Strings>(s));
* Support multiple outputs. A derivation can declare multiple outputs by setting the ‘outputs’ attribute. For example: stdenv.mkDerivation { name = "aterm-2.5"; src = ...; outputs = [ "out" "tools" "dev" ]; configureFlags = "--bindir=$(tools)/bin --includedir=$(dev)/include"; } This derivation creates three outputs, named like this: /nix/store/gcnqgllbh01p3d448q8q6pzn2nc2gpyl-aterm-2.5 /nix/store/gjf1sgirwfnrlr0bdxyrwzpw2r304j02-aterm-2.5-tools /nix/store/hp6108bqfgxvza25nnxfs7kj88xi2vdx-aterm-2.5-dev That is, the symbolic name of the output is suffixed to the store path (except for the ‘out’ output). Each path is passed to the builder through the corresponding environment variable, e.g., ${tools}. The main reason for multiple outputs is to allow parts of a package to be distributed and garbage-collected separately. For instance, most packages depend on Glibc for its libraries, but don't need its header files. If these are separated into different store paths, then a package that depends on the Glibc libraries only causes the libraries and not the headers to be downloaded. The main problem with multiple outputs is that if one output exists while the others have been garbage-collected (or never downloaded in the first place), and we want to rebuild the other outputs, then this isn't possible because we can't clobber a valid output (it might be in active use). This currently gives an error message like: error: derivation `/nix/store/1s9zw4c8qydpjyrayxamx2z7zzp5pcgh-aterm-2.5.drv' is blocked by its output paths There are two solutions: 1) Do the build in a chroot. Then we don't need to overwrite the existing path. 2) Use hash rewriting (see the ASE-2005 paper). Scary but it should work. This is not finished yet. There is not yet an easy way to refer to non-default outputs in Nix expressions. Also, mutually recursive outputs aren't detected yet and cause the garbage collector to crash.
2011-07-18 23:31:03 +00:00
}
Add support for passing structured data to builders Previously, all derivation attributes had to be coerced into strings so that they could be passed via the environment. This is lossy (e.g. lists get flattened, necessitating configureFlags vs. configureFlagsArray, of which the latter cannot be specified as an attribute), doesn't support attribute sets at all, and has size limitations (necessitating hacks like passAsFile). This patch adds a new mode for passing attributes to builders, namely encoded as a JSON file ".attrs.json" in the current directory of the builder. This mode is activated via the special attribute __structuredAttrs = true; (The idea is that one day we can set this in stdenv.mkDerivation.) For example, stdenv.mkDerivation { __structuredAttrs = true; name = "foo"; buildInputs = [ pkgs.hello pkgs.cowsay ]; doCheck = true; hardening.format = false; } results in a ".attrs.json" file containing (sans the indentation): { "buildInputs": [], "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash", "configureFlags": [ "--with-foo", "--with-bar=1 2" ], "doCheck": true, "hardening": { "format": false }, "name": "foo", "nativeBuildInputs": [ "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10", "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03" ], "propagatedBuildInputs": [], "propagatedNativeBuildInputs": [], "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv", "system": "x86_64-linux" } "passAsFile" is ignored in this mode because it's not needed - large strings are included directly in the JSON representation. It is up to the builder to do something with the JSON representation. For example, in bash-based builders, lists/attrsets of string values could be mapped to bash (associative) arrays.
2017-01-25 15:42:07 +00:00
}
} catch (Error & e) {
e.addTrace(posDrvName,
2020-06-24 19:46:25 +00:00
"while evaluating the attribute '%1%' of the derivation '%2%'",
key, drvName);
throw;
}
}
Add support for passing structured data to builders Previously, all derivation attributes had to be coerced into strings so that they could be passed via the environment. This is lossy (e.g. lists get flattened, necessitating configureFlags vs. configureFlagsArray, of which the latter cannot be specified as an attribute), doesn't support attribute sets at all, and has size limitations (necessitating hacks like passAsFile). This patch adds a new mode for passing attributes to builders, namely encoded as a JSON file ".attrs.json" in the current directory of the builder. This mode is activated via the special attribute __structuredAttrs = true; (The idea is that one day we can set this in stdenv.mkDerivation.) For example, stdenv.mkDerivation { __structuredAttrs = true; name = "foo"; buildInputs = [ pkgs.hello pkgs.cowsay ]; doCheck = true; hardening.format = false; } results in a ".attrs.json" file containing (sans the indentation): { "buildInputs": [], "builder": "/nix/store/ygl61ycpr2vjqrx775l1r2mw1g2rb754-bash-4.3-p48/bin/bash", "configureFlags": [ "--with-foo", "--with-bar=1 2" ], "doCheck": true, "hardening": { "format": false }, "name": "foo", "nativeBuildInputs": [ "/nix/store/10h6li26i7g6z3mdpvra09yyf10mmzdr-hello-2.10", "/nix/store/4jnvjin0r6wp6cv1hdm5jbkx3vinlcvk-cowsay-3.03" ], "propagatedBuildInputs": [], "propagatedNativeBuildInputs": [], "stdenv": "/nix/store/f3hw3p8armnzy6xhd4h8s7anfjrs15n2-stdenv", "system": "x86_64-linux" } "passAsFile" is ignored in this mode because it's not needed - large strings are included directly in the JSON representation. It is up to the builder to do something with the JSON representation. For example, in bash-based builders, lists/attrsets of string values could be mapped to bash (associative) arrays.
2017-01-25 15:42:07 +00:00
if (jsonObject) {
jsonObject.reset();
drv.env.emplace("__json", jsonBuf.str());
}
/* Everything in the context of the strings in the derivation
attributes should be added as dependencies of the resulting
derivation. */
2015-07-17 17:24:28 +00:00
for (auto & path : context) {
/* Paths marked with `=' denote that the path of a derivation
is explicitly passed to the builder. Since that allows the
builder to gain access to every path in the dependency
graph of the derivation (including all outputs), all paths
in the graph must be added to this derivation's list of
inputs to ensure that they are available when the builder
runs. */
if (path.at(0) == '=') {
/* !!! This doesn't work if readOnlyMode is set. */
StorePathSet refs;
state.store->computeFSClosure(state.store->parseStorePath(std::string_view(path).substr(1)), refs);
2015-07-17 17:24:28 +00:00
for (auto & j : refs) {
drv.inputSrcs.insert(j);
if (j.isDerivation())
drv.inputDrvs[j] = state.store->readDerivation(j).outputNames();
}
}
/* Handle derivation outputs of the form !<name>!<path>. */
2011-12-21 15:33:30 +00:00
else if (path.at(0) == '!') {
std::pair<string, string> ctx = decodeContext(path);
drv.inputDrvs[state.store->parseStorePath(ctx.first)].insert(ctx.second);
}
2011-12-21 15:33:30 +00:00
/* Otherwise it's a source file. */
else
drv.inputSrcs.insert(state.store->parseStorePath(path));
}
/* Do we have all required attributes? */
if (drv.builder == "")
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("required attribute 'builder' missing"),
.errPos = posDrvName
});
if (drv.platform == "")
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("required attribute 'system' missing"),
.errPos = posDrvName
});
2006-09-21 18:52:05 +00:00
/* Check whether the derivation name is valid. */
if (isDerivation(drvName))
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("derivation names are not allowed to end in '%s'", drvExtension),
.errPos = posDrvName
});
if (outputHash) {
/* Handle fixed-output derivations.
Ignore `__contentAddressed` because fixed output derivations are
already content addressed. */
if (outputs.size() != 1 || *(outputs.begin()) != "out")
throw Error({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("multiple outputs are not supported in fixed-output derivations"),
.errPos = posDrvName
});
std::optional<HashType> ht = parseHashTypeOpt(outputHashAlgo);
Hash h = newHashAllowEmpty(*outputHash, ht);
auto outPath = state.store->makeFixedOutputPath(ingestionMethod, h, drvName);
drv.env["out"] = state.store->printStorePath(outPath);
drv.outputs.insert_or_assign("out", DerivationOutput {
.output = DerivationOutputCAFixed {
.hash = FixedOutputHash {
.method = ingestionMethod,
.hash = std::move(h),
},
},
});
}
else if (contentAddressed) {
HashType ht = parseHashType(outputHashAlgo);
for (auto & i : outputs) {
drv.env[i] = hashPlaceholder(i);
drv.outputs.insert_or_assign(i, DerivationOutput {
.output = DerivationOutputCAFloating {
.method = ingestionMethod,
.hashType = std::move(ht),
},
});
}
}
else {
/* Compute a hash over the "masked" store derivation, which is
the final one except that in the list of outputs, the
output paths are empty strings, and the corresponding
environment variables have an empty value. This ensures
that changes in the set of output names do get reflected in
the hash. */
2015-07-17 17:24:28 +00:00
for (auto & i : outputs) {
drv.env[i] = "";
drv.outputs.insert_or_assign(i,
DerivationOutput {
.output = DerivationOutputInputAddressed {
.path = StorePath::dummy,
},
});
* Support multiple outputs. A derivation can declare multiple outputs by setting the ‘outputs’ attribute. For example: stdenv.mkDerivation { name = "aterm-2.5"; src = ...; outputs = [ "out" "tools" "dev" ]; configureFlags = "--bindir=$(tools)/bin --includedir=$(dev)/include"; } This derivation creates three outputs, named like this: /nix/store/gcnqgllbh01p3d448q8q6pzn2nc2gpyl-aterm-2.5 /nix/store/gjf1sgirwfnrlr0bdxyrwzpw2r304j02-aterm-2.5-tools /nix/store/hp6108bqfgxvza25nnxfs7kj88xi2vdx-aterm-2.5-dev That is, the symbolic name of the output is suffixed to the store path (except for the ‘out’ output). Each path is passed to the builder through the corresponding environment variable, e.g., ${tools}. The main reason for multiple outputs is to allow parts of a package to be distributed and garbage-collected separately. For instance, most packages depend on Glibc for its libraries, but don't need its header files. If these are separated into different store paths, then a package that depends on the Glibc libraries only causes the libraries and not the headers to be downloaded. The main problem with multiple outputs is that if one output exists while the others have been garbage-collected (or never downloaded in the first place), and we want to rebuild the other outputs, then this isn't possible because we can't clobber a valid output (it might be in active use). This currently gives an error message like: error: derivation `/nix/store/1s9zw4c8qydpjyrayxamx2z7zzp5pcgh-aterm-2.5.drv' is blocked by its output paths There are two solutions: 1) Do the build in a chroot. Then we don't need to overwrite the existing path. 2) Use hash rewriting (see the ASE-2005 paper). Scary but it should work. This is not finished yet. There is not yet an easy way to refer to non-default outputs in Nix expressions. Also, mutually recursive outputs aren't detected yet and cause the garbage collector to crash.
2011-07-18 23:31:03 +00:00
}
// Regular, non-CA derivation should always return a single hash and not
// hash per output.
auto hashModulo = hashDerivationModulo(*state.store, Derivation(drv), true);
std::visit(overloaded {
[&](Hash h) {
for (auto & i : outputs) {
auto outPath = state.store->makeOutputPath(i, h, drvName);
drv.env[i] = state.store->printStorePath(outPath);
drv.outputs.insert_or_assign(i,
DerivationOutput {
.output = DerivationOutputInputAddressed {
.path = std::move(outPath),
},
});
}
},
[&](CaOutputHashes) {
// Shouldn't happen as the toplevel derivation is not CA.
assert(false);
},
[&](DeferredHash _) {
for (auto & i : outputs) {
drv.outputs.insert_or_assign(i,
DerivationOutput {
.output = DerivationOutputDeferred{},
});
}
},
},
hashModulo);
* Support multiple outputs. A derivation can declare multiple outputs by setting the ‘outputs’ attribute. For example: stdenv.mkDerivation { name = "aterm-2.5"; src = ...; outputs = [ "out" "tools" "dev" ]; configureFlags = "--bindir=$(tools)/bin --includedir=$(dev)/include"; } This derivation creates three outputs, named like this: /nix/store/gcnqgllbh01p3d448q8q6pzn2nc2gpyl-aterm-2.5 /nix/store/gjf1sgirwfnrlr0bdxyrwzpw2r304j02-aterm-2.5-tools /nix/store/hp6108bqfgxvza25nnxfs7kj88xi2vdx-aterm-2.5-dev That is, the symbolic name of the output is suffixed to the store path (except for the ‘out’ output). Each path is passed to the builder through the corresponding environment variable, e.g., ${tools}. The main reason for multiple outputs is to allow parts of a package to be distributed and garbage-collected separately. For instance, most packages depend on Glibc for its libraries, but don't need its header files. If these are separated into different store paths, then a package that depends on the Glibc libraries only causes the libraries and not the headers to be downloaded. The main problem with multiple outputs is that if one output exists while the others have been garbage-collected (or never downloaded in the first place), and we want to rebuild the other outputs, then this isn't possible because we can't clobber a valid output (it might be in active use). This currently gives an error message like: error: derivation `/nix/store/1s9zw4c8qydpjyrayxamx2z7zzp5pcgh-aterm-2.5.drv' is blocked by its output paths There are two solutions: 1) Do the build in a chroot. Then we don't need to overwrite the existing path. 2) Use hash rewriting (see the ASE-2005 paper). Scary but it should work. This is not finished yet. There is not yet an easy way to refer to non-default outputs in Nix expressions. Also, mutually recursive outputs aren't detected yet and cause the garbage collector to crash.
2011-07-18 23:31:03 +00:00
}
/* Write the resulting term into the Nix store directory. */
auto drvPath = writeDerivation(*state.store, drv, state.repair);
auto drvPathS = state.store->printStorePath(drvPath);
printMsg(lvlChatty, "instantiated '%1%' -> '%2%'", drvName, drvPathS);
2005-01-18 11:15:50 +00:00
/* Optimisation, but required in read-only mode! because in that
* Support multiple outputs. A derivation can declare multiple outputs by setting the ‘outputs’ attribute. For example: stdenv.mkDerivation { name = "aterm-2.5"; src = ...; outputs = [ "out" "tools" "dev" ]; configureFlags = "--bindir=$(tools)/bin --includedir=$(dev)/include"; } This derivation creates three outputs, named like this: /nix/store/gcnqgllbh01p3d448q8q6pzn2nc2gpyl-aterm-2.5 /nix/store/gjf1sgirwfnrlr0bdxyrwzpw2r304j02-aterm-2.5-tools /nix/store/hp6108bqfgxvza25nnxfs7kj88xi2vdx-aterm-2.5-dev That is, the symbolic name of the output is suffixed to the store path (except for the ‘out’ output). Each path is passed to the builder through the corresponding environment variable, e.g., ${tools}. The main reason for multiple outputs is to allow parts of a package to be distributed and garbage-collected separately. For instance, most packages depend on Glibc for its libraries, but don't need its header files. If these are separated into different store paths, then a package that depends on the Glibc libraries only causes the libraries and not the headers to be downloaded. The main problem with multiple outputs is that if one output exists while the others have been garbage-collected (or never downloaded in the first place), and we want to rebuild the other outputs, then this isn't possible because we can't clobber a valid output (it might be in active use). This currently gives an error message like: error: derivation `/nix/store/1s9zw4c8qydpjyrayxamx2z7zzp5pcgh-aterm-2.5.drv' is blocked by its output paths There are two solutions: 1) Do the build in a chroot. Then we don't need to overwrite the existing path. 2) Use hash rewriting (see the ASE-2005 paper). Scary but it should work. This is not finished yet. There is not yet an easy way to refer to non-default outputs in Nix expressions. Also, mutually recursive outputs aren't detected yet and cause the garbage collector to crash.
2011-07-18 23:31:03 +00:00
case we don't actually write store derivations, so we can't
2020-08-07 19:09:26 +00:00
read them later.
However, we don't bother doing this for floating CA derivations because
their "hash modulo" is indeterminate until built. */
if (drv.type() != DerivationType::CAFloating) {
auto h = hashDerivationModulo(*state.store, Derivation(drv), false);
drvHashes.lock()->insert_or_assign(drvPath, h);
}
2005-01-18 11:15:50 +00:00
* Support multiple outputs. A derivation can declare multiple outputs by setting the ‘outputs’ attribute. For example: stdenv.mkDerivation { name = "aterm-2.5"; src = ...; outputs = [ "out" "tools" "dev" ]; configureFlags = "--bindir=$(tools)/bin --includedir=$(dev)/include"; } This derivation creates three outputs, named like this: /nix/store/gcnqgllbh01p3d448q8q6pzn2nc2gpyl-aterm-2.5 /nix/store/gjf1sgirwfnrlr0bdxyrwzpw2r304j02-aterm-2.5-tools /nix/store/hp6108bqfgxvza25nnxfs7kj88xi2vdx-aterm-2.5-dev That is, the symbolic name of the output is suffixed to the store path (except for the ‘out’ output). Each path is passed to the builder through the corresponding environment variable, e.g., ${tools}. The main reason for multiple outputs is to allow parts of a package to be distributed and garbage-collected separately. For instance, most packages depend on Glibc for its libraries, but don't need its header files. If these are separated into different store paths, then a package that depends on the Glibc libraries only causes the libraries and not the headers to be downloaded. The main problem with multiple outputs is that if one output exists while the others have been garbage-collected (or never downloaded in the first place), and we want to rebuild the other outputs, then this isn't possible because we can't clobber a valid output (it might be in active use). This currently gives an error message like: error: derivation `/nix/store/1s9zw4c8qydpjyrayxamx2z7zzp5pcgh-aterm-2.5.drv' is blocked by its output paths There are two solutions: 1) Do the build in a chroot. Then we don't need to overwrite the existing path. 2) Use hash rewriting (see the ASE-2005 paper). Scary but it should work. This is not finished yet. There is not yet an easy way to refer to non-default outputs in Nix expressions. Also, mutually recursive outputs aren't detected yet and cause the garbage collector to crash.
2011-07-18 23:31:03 +00:00
state.mkAttrs(v, 1 + drv.outputs.size());
mkString(*state.allocAttr(v, state.sDrvPath), drvPathS, {"=" + drvPathS});
2020-08-07 19:09:26 +00:00
for (auto & i : drv.outputs)
mkOutputString(state, v, drvPath, drv, i);
v.attrs->sort();
2010-03-31 15:38:03 +00:00
}
2003-11-02 16:31:35 +00:00
static RegisterPrimOp primop_derivationStrict(RegisterPrimOp::Info {
.name = "derivationStrict",
.arity = 1,
.fun = prim_derivationStrict,
});
2003-11-02 16:31:35 +00:00
/* Return a placeholder string for the specified output that will be
substituted by the corresponding output path at build time. For
example, 'placeholder "out"' returns the string
/1rz4g4znpzjwh1xymhjpm42vipw92pr73vdgl6xs1hycac8kf2n9. At build
time, any occurence of this string in an derivation attribute will
be replaced with the concrete path in the Nix store of the output
out. */
static void prim_placeholder(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
mkString(v, hashPlaceholder(state.forceStringNoCtx(*args[0], pos)));
}
static RegisterPrimOp primop_placeholder({
.name = "placeholder",
.args = {"output"},
.doc = R"(
Return a placeholder string for the specified *output* that will be
substituted by the corresponding output path at build time. Typical
outputs would be `"out"`, `"bin"` or `"dev"`.
)",
.fun = prim_placeholder,
});
2007-01-29 15:11:32 +00:00
/*************************************************************
* Paths
*************************************************************/
/* Convert the argument to a path. !!! obsolete? */
static void prim_toPath(EvalState & state, const Pos & pos, Value * * args, Value & v)
2003-11-02 16:31:35 +00:00
{
PathSet context;
Path path = state.coerceToPath(pos, *args[0], context);
mkString(v, canonPath(path), context);
2003-11-02 16:31:35 +00:00
}
static RegisterPrimOp primop_toPath({
.name = "__toPath",
.args = {"s"},
.doc = R"(
2020-08-25 09:16:45 +00:00
**DEPRECATED.** Use `/. + "/path"` to convert a string into an absolute
path. For relative paths, use `./. + "/path"`.
)",
.fun = prim_toPath,
});
2003-11-02 16:31:35 +00:00
/* Allow a valid store path to be used in an expression. This is
useful in some generated expressions such as in nix-push, which
generates a call to a function with an already existing store path
as argument. You don't want to use `toPath' here because it copies
the path to the Nix store, which yields a copy like
/nix/store/newhash-oldhash-oldname. In the past, `toPath' had
special case behaviour for store paths, but that created weird
corner cases. */
static void prim_storePath(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
if (evalSettings.pureEval)
throw EvalError({
.msg = hintfmt("'%s' is not allowed in pure evaluation mode", "builtins.storePath"),
.errPos = pos
});
PathSet context;
Path path = state.checkSourcePath(state.coerceToPath(pos, *args[0], context));
/* Resolve symlinks in path, unless path itself is a symlink
directly in the store. The latter condition is necessary so
e.g. nix-push does the right thing. */
if (!state.store->isStorePath(path)) path = canonPath(path, true);
if (!state.store->isInStore(path))
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("path '%1%' is not in the Nix store", path),
.errPos = pos
});
auto path2 = state.store->toStorePath(path).first;
if (!settings.readOnlyMode)
state.store->ensurePath(path2);
context.insert(state.store->printStorePath(path2));
2010-04-16 15:13:47 +00:00
mkString(v, path, context);
}
2020-08-25 09:16:45 +00:00
static RegisterPrimOp primop_storePath({
.name = "__storePath",
.args = {"path"},
.doc = R"(
This function allows you to define a dependency on an already
existing store path. For example, the derivation attribute `src
= builtins.storePath /nix/store/f1d18v1y-source` causes the
derivation to depend on the specified path, which must exist or
be substitutable. Note that this differs from a plain path
(e.g. `src = /nix/store/f1d18v1y-source`) in that the latter
causes the path to be *copied* again to the Nix store, resulting
in a new path (e.g. `/nix/store/ld01dnzc-source-source`).
This function is not available in pure evaluation mode.
)",
.fun = prim_storePath,
});
static void prim_pathExists(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
PathSet context;
Path path = state.coerceToPath(pos, *args[0], context);
try {
state.realiseContext(context);
} catch (InvalidPathError & e) {
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt(
"cannot check the existence of '%1%', since path '%2%' is not valid",
path, e.path),
.errPos = pos
});
}
try {
mkBool(v, pathExists(state.checkSourcePath(path)));
} catch (SysError & e) {
/* Don't give away info from errors while canonicalising
path in restricted mode. */
mkBool(v, false);
} catch (RestrictedPathError & e) {
mkBool(v, false);
}
}
static RegisterPrimOp primop_pathExists({
.name = "__pathExists",
.args = {"path"},
.doc = R"(
Return `true` if the path *path* exists at evaluation time, and
`false` otherwise.
)",
.fun = prim_pathExists,
});
2007-01-29 15:11:32 +00:00
/* Return the base name of the given string, i.e., everything
following the last slash. */
static void prim_baseNameOf(EvalState & state, const Pos & pos, Value * * args, Value & v)
2003-11-02 16:31:35 +00:00
{
PathSet context;
mkString(v, baseNameOf(state.coerceToString(pos, *args[0], context, false, false)), context);
2003-11-02 16:31:35 +00:00
}
static RegisterPrimOp primop_baseNameOf({
.name = "baseNameOf",
.args = {"s"},
.doc = R"(
Return the *base name* of the string *s*, that is, everything
following the final slash in the string. This is similar to the GNU
`basename` command.
)",
.fun = prim_baseNameOf,
});
2007-01-29 15:11:32 +00:00
/* Return the directory of the given path, i.e., everything before the
last slash. Return either a path or a string depending on the type
of the argument. */
static void prim_dirOf(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
PathSet context;
2018-08-13 09:27:35 +00:00
Path dir = dirOf(state.coerceToString(pos, *args[0], context, false, false));
if (args[0]->type() == nPath) mkPath(v, dir.c_str()); else mkString(v, dir, context);
}
static RegisterPrimOp primop_dirOf({
.name = "dirOf",
.args = {"s"},
.doc = R"(
Return the directory part of the string *s*, that is, everything
before the final slash in the string. This is similar to the GNU
`dirname` command.
)",
.fun = prim_dirOf,
});
/* Return the contents of a file as a string. */
static void prim_readFile(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
PathSet context;
Path path = state.coerceToPath(pos, *args[0], context);
try {
state.realiseContext(context);
} catch (InvalidPathError & e) {
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("cannot read '%1%', since path '%2%' is not valid", path, e.path),
.errPos = pos
});
}
string s = readFile(state.checkSourcePath(state.toRealPath(path, context)));
2015-06-01 13:07:42 +00:00
if (s.find((char) 0) != string::npos)
throw Error("the contents of the file '%1%' cannot be represented as a Nix string", path);
mkString(v, s.c_str());
}
static RegisterPrimOp primop_readFile({
.name = "__readFile",
.args = {"path"},
.doc = R"(
Return the contents of the file *path* as a string.
)",
.fun = prim_readFile,
});
/* Find a file in the Nix search path. Used to implement <x> paths,
which are desugared to 'findFile __nixPath "x"'. */
static void prim_findFile(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceList(*args[0], pos);
SearchPath searchPath;
for (unsigned int n = 0; n < args[0]->listSize(); ++n) {
Value & v2(*args[0]->listElems()[n]);
state.forceAttrs(v2, pos);
string prefix;
Bindings::iterator i = v2.attrs->find(state.symbols.create("prefix"));
if (i != v2.attrs->end())
prefix = state.forceStringNoCtx(*i->value, pos);
2021-04-13 21:08:59 +00:00
i = getAttr(
state,
"findFile",
"path",
v2.attrs,
pos
);
PathSet context;
string path = state.coerceToString(pos, *i->value, context, false, false);
try {
state.realiseContext(context);
} catch (InvalidPathError & e) {
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("cannot find '%1%', since path '%2%' is not valid", path, e.path),
.errPos = pos
});
}
searchPath.emplace_back(prefix, path);
}
string path = state.forceStringNoCtx(*args[1], pos);
mkPath(v, state.checkSourcePath(state.findFile(searchPath, path, pos)).c_str());
}
static RegisterPrimOp primop_findFile(RegisterPrimOp::Info {
.name = "__findFile",
.arity = 2,
.fun = prim_findFile,
});
/* Return the cryptographic hash of a file in base-16. */
static void prim_hashFile(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
string type = state.forceStringNoCtx(*args[0], pos);
std::optional<HashType> ht = parseHashType(type);
if (!ht)
throw Error({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("unknown hash type '%1%'", type),
.errPos = pos
});
PathSet context; // discarded
Path p = state.coerceToPath(pos, *args[1], context);
mkString(v, hashFile(*ht, state.checkSourcePath(p)).to_string(Base16, false), context);
}
static RegisterPrimOp primop_hashFile({
.name = "__hashFile",
.args = {"type", "p"},
.doc = R"(
Return a base-16 representation of the cryptographic hash of the
file at path *p*. The hash algorithm specified by *type* must be one
of `"md5"`, `"sha1"`, `"sha256"` or `"sha512"`.
)",
.fun = prim_hashFile,
});
2014-10-01 14:17:50 +00:00
/* Read a directory (without . or ..) */
static void prim_readDir(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
PathSet ctx;
Path path = state.coerceToPath(pos, *args[0], ctx);
try {
state.realiseContext(ctx);
2014-10-01 14:17:50 +00:00
} catch (InvalidPathError & e) {
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("cannot read '%1%', since path '%2%' is not valid", path, e.path),
.errPos = pos
});
2014-10-01 14:17:50 +00:00
}
DirEntries entries = readDirectory(state.checkSourcePath(path));
2014-10-01 14:17:50 +00:00
state.mkAttrs(v, entries.size());
2014-10-03 20:37:51 +00:00
for (auto & ent : entries) {
2014-10-01 14:17:50 +00:00
Value * ent_val = state.allocAttr(v, state.symbols.create(ent.name));
2014-10-03 20:37:51 +00:00
if (ent.type == DT_UNKNOWN)
ent.type = getFileType(path + "/" + ent.name);
ent_val->mkString(
2014-10-03 20:37:51 +00:00
ent.type == DT_REG ? "regular" :
ent.type == DT_DIR ? "directory" :
ent.type == DT_LNK ? "symlink" :
"unknown");
2014-10-01 14:17:50 +00:00
}
v.attrs->sort();
}
static RegisterPrimOp primop_readDir({
.name = "__readDir",
.args = {"path"},
.doc = R"(
Return the contents of the directory *path* as a set mapping
directory entries to the corresponding file type. For instance, if
directory `A` contains a regular file `B` and another directory
`C`, then `builtins.readDir ./A` will return the set
```nix
{ B = "regular"; C = "directory"; }
```
The possible values for the file type are `"regular"`,
`"directory"`, `"symlink"` and `"unknown"`.
)",
.fun = prim_readDir,
});
2007-01-29 15:11:32 +00:00
/*************************************************************
* Creating files
*************************************************************/
/* Convert the argument (which can be any Nix expression) to an XML
representation returned in a string. Not all Nix expressions can
be sensibly or completely represented (e.g., functions). */
static void prim_toXML(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
std::ostringstream out;
PathSet context;
2010-05-07 14:46:47 +00:00
printValueAsXML(state, true, false, *args[0], out, context);
mkString(v, out.str(), context);
}
static RegisterPrimOp primop_toXML({
.name = "__toXML",
.args = {"e"},
.doc = R"(
Return a string containing an XML representation of *e*. The main
application for `toXML` is to communicate information with the
builder in a more structured format than plain environment
variables.
Here is an example where this is the case:
```nix
{ stdenv, fetchurl, libxslt, jira, uberwiki }:
stdenv.mkDerivation (rec {
name = "web-server";
buildInputs = [ libxslt ];
builder = builtins.toFile "builder.sh" "
source $stdenv/setup
mkdir $out
echo "$servlets" | xsltproc ${stylesheet} - > $out/server-conf.xml
";
stylesheet = builtins.toFile "stylesheet.xsl"
"<?xml version='1.0' encoding='UTF-8'?>
<xsl:stylesheet xmlns:xsl='http://www.w3.org/1999/XSL/Transform' version='1.0'>
<xsl:template match='/'>
<Configure>
<xsl:for-each select='/expr/list/attrs'>
<Call name='addWebApplication'>
<Arg><xsl:value-of select=\"attr[@name = 'path']/string/@value\" /></Arg>
<Arg><xsl:value-of select=\"attr[@name = 'war']/path/@value\" /></Arg>
</Call>
</xsl:for-each>
</Configure>
</xsl:template>
</xsl:stylesheet>
";
servlets = builtins.toXML [
{ path = "/bugtracker"; war = jira + "/lib/atlassian-jira.war"; }
{ path = "/wiki"; war = uberwiki + "/uberwiki.war"; }
];
})
```
The builder is supposed to generate the configuration file for a
[Jetty servlet container](http://jetty.mortbay.org/). A servlet
container contains a number of servlets (`*.war` files) each
exported under a specific URI prefix. So the servlet configuration
is a list of sets containing the `path` and `war` of the servlet
(). This kind of information is difficult to communicate with the
normal method of passing information through an environment
variable, which just concatenates everything together into a
string (which might just work in this case, but wouldnt work if
fields are optional or contain lists themselves). Instead the Nix
expression is converted to an XML representation with `toXML`,
which is unambiguous and can easily be processed with the
appropriate tools. For instance, in the example an XSLT stylesheet
(at point ) is applied to it (at point ) to generate the XML
configuration file for the Jetty server. The XML representation
produced at point by `toXML` is as follows:
```xml
<?xml version='1.0' encoding='utf-8'?>
<expr>
<list>
<attrs>
<attr name="path">
<string value="/bugtracker" />
</attr>
<attr name="war">
<path value="/nix/store/d1jh9pasa7k2...-jira/lib/atlassian-jira.war" />
</attr>
</attrs>
<attrs>
<attr name="path">
<string value="/wiki" />
</attr>
<attr name="war">
<path value="/nix/store/y6423b1yi4sx...-uberwiki/uberwiki.war" />
</attr>
</attrs>
</list>
</expr>
```
Note that we used the `toFile` built-in to write the builder and
the stylesheet inline in the Nix expression. The path of the
stylesheet is spliced into the builder using the syntax `xsltproc
${stylesheet}`.
)",
.fun = prim_toXML,
});
2013-11-18 23:03:11 +00:00
/* Convert the argument (which can be any Nix expression) to a JSON
string. Not all Nix expressions can be sensibly or completely
represented (e.g., functions). */
static void prim_toJSON(EvalState & state, const Pos & pos, Value * * args, Value & v)
2013-11-18 23:03:11 +00:00
{
std::ostringstream out;
PathSet context;
printValueAsJSON(state, true, *args[0], out, context);
mkString(v, out.str(), context);
}
static RegisterPrimOp primop_toJSON({
.name = "__toJSON",
.args = {"e"},
.doc = R"(
Return a string containing a JSON representation of *e*. Strings,
integers, floats, booleans, nulls and lists are mapped to their JSON
equivalents. Sets (except derivations) are represented as objects.
Derivations are translated to a JSON string containing the
derivations output path. Paths are copied to the store and
represented as a JSON string of the resulting store path.
)",
.fun = prim_toJSON,
});
2013-11-18 23:03:11 +00:00
/* Parse a JSON string to a value. */
static void prim_fromJSON(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
string s = state.forceStringNoCtx(*args[0], pos);
try {
parseJSON(state, s, v);
} catch (JSONParseError &e) {
e.addTrace(pos, "while decoding a JSON string");
throw e;
}
}
static RegisterPrimOp primop_fromJSON({
.name = "__fromJSON",
.args = {"e"},
.doc = R"(
Convert a JSON string to a Nix value. For example,
```nix
builtins.fromJSON ''{"x": [1, 2, 3], "y": null}''
```
returns the value `{ x = [ 1 2 3 ]; y = null; }`.
)",
.fun = prim_fromJSON,
});
/* Store a string in the Nix store as a source file that can be used
as an input by derivations. */
static void prim_toFile(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
PathSet context;
2014-04-04 19:14:11 +00:00
string name = state.forceStringNoCtx(*args[0], pos);
2014-11-25 09:23:36 +00:00
string contents = state.forceString(*args[1], context, pos);
StorePathSet refs;
2015-07-17 17:24:28 +00:00
for (auto path : context) {
if (path.at(0) != '/')
throw EvalError( {
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt(
"in 'toFile': the file named '%1%' must not contain a reference "
"to a derivation but contains (%2%)",
name, path),
.errPos = pos
});
refs.insert(state.store->parseStorePath(path));
}
2013-09-02 14:29:15 +00:00
auto storePath = state.store->printStorePath(settings.readOnlyMode
? state.store->computeStorePathForText(name, contents, refs)
: state.store->addTextToStore(name, contents, refs, state.repair));
/* Note: we don't need to add `context' to the context of the
result, since `storePath' itself has references to the paths
used in args[1]. */
2010-03-31 15:38:03 +00:00
2016-05-04 14:04:52 +00:00
mkString(v, storePath, {storePath});
}
static RegisterPrimOp primop_toFile({
.name = "__toFile",
.args = {"name", "s"},
.doc = R"(
Store the string *s* in a file in the Nix store and return its
path. The file has suffix *name*. This file can be used as an
input to derivations. One application is to write builders
inline. For instance, the following Nix expression combines the
[Nix expression for GNU Hello](expression-syntax.md) and its
[build script](build-script.md) into one file:
```nix
{ stdenv, fetchurl, perl }:
stdenv.mkDerivation {
name = "hello-2.1.1";
builder = builtins.toFile "builder.sh" "
source $stdenv/setup
PATH=$perl/bin:$PATH
tar xvfz $src
cd hello-*
./configure --prefix=$out
make
make install
";
src = fetchurl {
url = "http://ftp.nluug.nl/pub/gnu/hello/hello-2.1.1.tar.gz";
sha256 = "1md7jsfd8pa45z73bz1kszpp01yw6x5ljkjk2hx7wl800any6465";
};
inherit perl;
}
```
It is even possible for one file to refer to another, e.g.,
```nix
builder = let
configFile = builtins.toFile "foo.conf" "
# This is some dummy configuration file.
...
";
in builtins.toFile "builder.sh" "
source $stdenv/setup
...
cp ${configFile} $out/etc/foo.conf
";
2020-09-16 12:18:46 +00:00
```
Note that `${configFile}` is an
[antiquotation](language-values.md), so the result of the
expression `configFile`
(i.e., a path like `/nix/store/m7p7jfny445k...-foo.conf`) will be
spliced into the resulting string.
It is however *not* allowed to have files mutually referring to each
other, like so:
```nix
let
foo = builtins.toFile "foo" "...${bar}...";
bar = builtins.toFile "bar" "...${foo}...";
in foo
```
This is not allowed because it would cause a cyclic dependency in
the computation of the cryptographic hashes for `foo` and `bar`.
It is also not possible to reference the result of a derivation. If
you are using Nixpkgs, the `writeTextFile` function is able to do
that.
)",
.fun = prim_toFile,
});
static void addPath(EvalState & state, const Pos & pos, const string & name, const Path & path_,
2020-06-19 20:50:28 +00:00
Value * filterFun, FileIngestionMethod method, const std::optional<Hash> expectedHash, Value & v)
{
const auto path = evalSettings.pureEval && expectedHash ?
path_ :
state.checkSourcePath(path_);
PathFilter filter = filterFun ? ([&](const Path & path) {
2017-10-31 15:14:25 +00:00
auto st = lstat(path);
/* Call the filter function. The first argument is the path,
the second is a string indicating the type of the file. */
Value arg1;
mkString(arg1, path);
Value fun2;
state.callFunction(*filterFun, arg1, fun2, noPos);
Value arg2;
2013-09-02 14:29:15 +00:00
mkString(arg2,
S_ISREG(st.st_mode) ? "regular" :
S_ISDIR(st.st_mode) ? "directory" :
S_ISLNK(st.st_mode) ? "symlink" :
"unknown" /* not supported, will fail! */);
2013-09-02 14:29:15 +00:00
Value res;
state.callFunction(fun2, arg2, res, noPos);
2016-08-29 15:56:35 +00:00
return state.forceBool(res, pos);
}) : defaultPathFilter;
std::optional<StorePath> expectedStorePath;
if (expectedHash)
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expectedStorePath = state.store->makeFixedOutputPath(method, *expectedHash, name);
Path dstPath;
if (!expectedHash || !state.store->isValidPath(*expectedStorePath)) {
dstPath = state.store->printStorePath(settings.readOnlyMode
? state.store->computeStorePathForPath(name, path, method, htSHA256, filter).first
: state.store->addToStore(name, path, method, htSHA256, filter, state.repair));
if (expectedHash && expectedStorePath != state.store->parseStorePath(dstPath))
throw Error("store path mismatch in (possibly filtered) path added from '%s'", path);
} else
dstPath = state.store->printStorePath(*expectedStorePath);
2016-05-04 14:04:52 +00:00
mkString(v, dstPath, {dstPath});
if (state.allowedPaths)
state.allowedPaths->insert(v.string.s);
try {
state.realiseContext({});
} catch (InvalidPathError & e) {
throw EvalError({
.msg = hintfmt("cannot import '%1%', since path '%2%' is not valid", path, e.path),
.errPos = pos
});
} catch (Error & e) {
e.addTrace(pos, "while importing '%s'", path);
throw e;
}
}
static void prim_filterSource(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
PathSet context;
Path path = state.coerceToPath(pos, *args[1], context);
if (!context.empty())
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("string '%1%' cannot refer to other paths", path),
.errPos = pos
});
state.forceValue(*args[0], pos);
if (args[0]->type() != nFunction)
throw TypeError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt(
"first argument in call to 'filterSource' is not a function but %1%",
showType(*args[0])),
.errPos = pos
});
2020-06-19 20:50:28 +00:00
addPath(state, pos, std::string(baseNameOf(path)), path, args[0], FileIngestionMethod::Recursive, std::nullopt, v);
}
static RegisterPrimOp primop_filterSource({
.name = "__filterSource",
.args = {"e1", "e2"},
.doc = R"(
This function allows you to copy sources into the Nix store while
filtering certain files. For instance, suppose that you want to use
the directory `source-dir` as an input to a Nix expression, e.g.
```nix
stdenv.mkDerivation {
...
src = ./source-dir;
}
```
However, if `source-dir` is a Subversion working copy, then all
those annoying `.svn` subdirectories will also be copied to the
store. Worse, the contents of those directories may change a lot,
causing lots of spurious rebuilds. With `filterSource` you can
filter out the `.svn` directories:
```nix
src = builtins.filterSource
(path: type: type != "directory" || baseNameOf path != ".svn")
./source-dir;
```
Thus, the first argument *e1* must be a predicate function that is
called for each regular file, directory or symlink in the source
tree *e2*. If the function returns `true`, the file is copied to the
Nix store, otherwise it is omitted. The function is called with two
arguments. The first is the full path of the file. The second is a
string that identifies the type of the file, which is either
`"regular"`, `"directory"`, `"symlink"` or `"unknown"` (for other
kinds of files such as device nodes or fifos but note that those
cannot be copied to the Nix store, so if the predicate returns
`true` for them, the copy will fail). If you exclude a directory,
the entire corresponding subtree of *e2* will be excluded.
)",
.fun = prim_filterSource,
});
static void prim_path(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceAttrs(*args[0], pos);
Path path;
string name;
Value * filterFun = nullptr;
auto method = FileIngestionMethod::Recursive;
std::optional<Hash> expectedHash;
for (auto & attr : *args[0]->attrs) {
const string & n(attr.name);
if (n == "path") {
PathSet context;
path = state.coerceToPath(*attr.pos, *attr.value, context);
if (!context.empty())
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("string '%1%' cannot refer to other paths", path),
.errPos = *attr.pos
});
} else if (attr.name == state.sName)
name = state.forceStringNoCtx(*attr.value, *attr.pos);
else if (n == "filter") {
state.forceValue(*attr.value, pos);
filterFun = attr.value;
} else if (n == "recursive")
method = FileIngestionMethod { state.forceBool(*attr.value, *attr.pos) };
else if (n == "sha256")
expectedHash = newHashAllowEmpty(state.forceStringNoCtx(*attr.value, *attr.pos), htSHA256);
else
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("unsupported argument '%1%' to 'addPath'", attr.name),
.errPos = *attr.pos
});
}
if (path.empty())
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("'path' required"),
.errPos = pos
});
if (name.empty())
name = baseNameOf(path);
addPath(state, pos, name, path, filterFun, method, expectedHash, v);
}
static RegisterPrimOp primop_path({
.name = "__path",
.args = {"args"},
.doc = R"(
An enrichment of the built-in path type, based on the attributes
present in *args*. All are optional except `path`:
- path\
The underlying path.
- name\
The name of the path when added to the store. This can used to
reference paths that have nix-illegal characters in their names,
like `@`.
- filter\
A function of the type expected by `builtins.filterSource`,
with the same semantics.
- recursive\
When `false`, when `path` is added to the store it is with a
flat hash, rather than a hash of the NAR serialization of the
file. Thus, `path` must refer to a regular file, not a
directory. This allows similar behavior to `fetchurl`. Defaults
to `true`.
- sha256\
When provided, this is the expected hash of the file at the
path. Evaluation will fail if the hash is incorrect, and
providing a hash allows `builtins.path` to be used even when the
`pure-eval` nix config option is on.
)",
.fun = prim_path,
});
2007-01-29 15:11:32 +00:00
/*************************************************************
* Sets
2007-01-29 15:11:32 +00:00
*************************************************************/
* A primitive operation `dependencyClosure' to do automatic dependency determination (e.g., finding the header files dependencies of a C file) in Nix low-level builds automatically. For instance, in the function `compileC' in make/lib/default.nix, we find the header file dependencies of C file `main' as follows: localIncludes = dependencyClosure { scanner = file: import (findIncludes { inherit file; }); startSet = [main]; }; The function works by "growing" the set of dependencies, starting with the set `startSet', and calling the function `scanner' for each file to get its dependencies (which should yield a list of strings representing relative paths). For instance, when `scanner' is called on a file `foo.c' that includes the line #include "../bar/fnord.h" then `scanner' should yield ["../bar/fnord.h"]. This list of dependencies is absolutised relative to the including file and added to the set of dependencies. The process continues until no more dependencies are found (hence its a closure). `dependencyClosure' yields a list that contains in alternation a dependency, and its relative path to the directory of the start file, e.g., [ /bla/bla/foo.c "foo.c" /bla/bar/fnord.h "../bar/fnord.h" ] These relative paths are necessary for the builder that compiles foo.c to reconstruct the relative directory structure expected by foo.c. The advantage of `dependencyClosure' over the old approach (using the impure `__currentTime') is that it's completely pure, and more efficient because it only rescans for dependencies (i.e., by building the derivations yielded by `scanner') if sources have actually changed. The old approach rescanned every time.
2005-08-14 12:38:47 +00:00
/* Return the names of the attributes in a set as a sorted list of
strings. */
static void prim_attrNames(EvalState & state, const Pos & pos, Value * * args, Value & v)
* A primitive operation `dependencyClosure' to do automatic dependency determination (e.g., finding the header files dependencies of a C file) in Nix low-level builds automatically. For instance, in the function `compileC' in make/lib/default.nix, we find the header file dependencies of C file `main' as follows: localIncludes = dependencyClosure { scanner = file: import (findIncludes { inherit file; }); startSet = [main]; }; The function works by "growing" the set of dependencies, starting with the set `startSet', and calling the function `scanner' for each file to get its dependencies (which should yield a list of strings representing relative paths). For instance, when `scanner' is called on a file `foo.c' that includes the line #include "../bar/fnord.h" then `scanner' should yield ["../bar/fnord.h"]. This list of dependencies is absolutised relative to the including file and added to the set of dependencies. The process continues until no more dependencies are found (hence its a closure). `dependencyClosure' yields a list that contains in alternation a dependency, and its relative path to the directory of the start file, e.g., [ /bla/bla/foo.c "foo.c" /bla/bar/fnord.h "../bar/fnord.h" ] These relative paths are necessary for the builder that compiles foo.c to reconstruct the relative directory structure expected by foo.c. The advantage of `dependencyClosure' over the old approach (using the impure `__currentTime') is that it's completely pure, and more efficient because it only rescans for dependencies (i.e., by building the derivations yielded by `scanner') if sources have actually changed. The old approach rescanned every time.
2005-08-14 12:38:47 +00:00
{
2014-04-04 17:11:40 +00:00
state.forceAttrs(*args[0], pos);
* A primitive operation `dependencyClosure' to do automatic dependency determination (e.g., finding the header files dependencies of a C file) in Nix low-level builds automatically. For instance, in the function `compileC' in make/lib/default.nix, we find the header file dependencies of C file `main' as follows: localIncludes = dependencyClosure { scanner = file: import (findIncludes { inherit file; }); startSet = [main]; }; The function works by "growing" the set of dependencies, starting with the set `startSet', and calling the function `scanner' for each file to get its dependencies (which should yield a list of strings representing relative paths). For instance, when `scanner' is called on a file `foo.c' that includes the line #include "../bar/fnord.h" then `scanner' should yield ["../bar/fnord.h"]. This list of dependencies is absolutised relative to the including file and added to the set of dependencies. The process continues until no more dependencies are found (hence its a closure). `dependencyClosure' yields a list that contains in alternation a dependency, and its relative path to the directory of the start file, e.g., [ /bla/bla/foo.c "foo.c" /bla/bar/fnord.h "../bar/fnord.h" ] These relative paths are necessary for the builder that compiles foo.c to reconstruct the relative directory structure expected by foo.c. The advantage of `dependencyClosure' over the old approach (using the impure `__currentTime') is that it's completely pure, and more efficient because it only rescans for dependencies (i.e., by building the derivations yielded by `scanner') if sources have actually changed. The old approach rescanned every time.
2005-08-14 12:38:47 +00:00
2010-03-30 22:39:48 +00:00
state.mkList(v, args[0]->attrs->size());
* A primitive operation `dependencyClosure' to do automatic dependency determination (e.g., finding the header files dependencies of a C file) in Nix low-level builds automatically. For instance, in the function `compileC' in make/lib/default.nix, we find the header file dependencies of C file `main' as follows: localIncludes = dependencyClosure { scanner = file: import (findIncludes { inherit file; }); startSet = [main]; }; The function works by "growing" the set of dependencies, starting with the set `startSet', and calling the function `scanner' for each file to get its dependencies (which should yield a list of strings representing relative paths). For instance, when `scanner' is called on a file `foo.c' that includes the line #include "../bar/fnord.h" then `scanner' should yield ["../bar/fnord.h"]. This list of dependencies is absolutised relative to the including file and added to the set of dependencies. The process continues until no more dependencies are found (hence its a closure). `dependencyClosure' yields a list that contains in alternation a dependency, and its relative path to the directory of the start file, e.g., [ /bla/bla/foo.c "foo.c" /bla/bar/fnord.h "../bar/fnord.h" ] These relative paths are necessary for the builder that compiles foo.c to reconstruct the relative directory structure expected by foo.c. The advantage of `dependencyClosure' over the old approach (using the impure `__currentTime') is that it's completely pure, and more efficient because it only rescans for dependencies (i.e., by building the derivations yielded by `scanner') if sources have actually changed. The old approach rescanned every time.
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size_t n = 0;
for (auto & i : *args[0]->attrs)
mkString(*(v.listElems()[n++] = state.allocValue()), i.name);
std::sort(v.listElems(), v.listElems() + n,
[](Value * v1, Value * v2) { return strcmp(v1->string.s, v2->string.s) < 0; });
2014-10-04 14:41:24 +00:00
}
static RegisterPrimOp primop_attrNames({
.name = "__attrNames",
.args = {"set"},
.doc = R"(
Return the names of the attributes in the set *set* in an
alphabetically sorted list. For instance, `builtins.attrNames { y
= 1; x = "foo"; }` evaluates to `[ "x" "y" ]`.
)",
.fun = prim_attrNames,
});
2014-10-04 14:41:24 +00:00
/* Return the values of the attributes in a set as a list, in the same
order as attrNames. */
static void prim_attrValues(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceAttrs(*args[0], pos);
state.mkList(v, args[0]->attrs->size());
unsigned int n = 0;
for (auto & i : *args[0]->attrs)
v.listElems()[n++] = (Value *) &i;
2014-10-04 14:41:24 +00:00
std::sort(v.listElems(), v.listElems() + n,
2014-10-04 14:41:24 +00:00
[](Value * v1, Value * v2) { return (string) ((Attr *) v1)->name < (string) ((Attr *) v2)->name; });
for (unsigned int i = 0; i < n; ++i)
v.listElems()[i] = ((Attr *) v.listElems()[i])->value;
* A primitive operation `dependencyClosure' to do automatic dependency determination (e.g., finding the header files dependencies of a C file) in Nix low-level builds automatically. For instance, in the function `compileC' in make/lib/default.nix, we find the header file dependencies of C file `main' as follows: localIncludes = dependencyClosure { scanner = file: import (findIncludes { inherit file; }); startSet = [main]; }; The function works by "growing" the set of dependencies, starting with the set `startSet', and calling the function `scanner' for each file to get its dependencies (which should yield a list of strings representing relative paths). For instance, when `scanner' is called on a file `foo.c' that includes the line #include "../bar/fnord.h" then `scanner' should yield ["../bar/fnord.h"]. This list of dependencies is absolutised relative to the including file and added to the set of dependencies. The process continues until no more dependencies are found (hence its a closure). `dependencyClosure' yields a list that contains in alternation a dependency, and its relative path to the directory of the start file, e.g., [ /bla/bla/foo.c "foo.c" /bla/bar/fnord.h "../bar/fnord.h" ] These relative paths are necessary for the builder that compiles foo.c to reconstruct the relative directory structure expected by foo.c. The advantage of `dependencyClosure' over the old approach (using the impure `__currentTime') is that it's completely pure, and more efficient because it only rescans for dependencies (i.e., by building the derivations yielded by `scanner') if sources have actually changed. The old approach rescanned every time.
2005-08-14 12:38:47 +00:00
}
static RegisterPrimOp primop_attrValues({
.name = "__attrValues",
.args = {"set"},
.doc = R"(
Return the values of the attributes in the set *set* in the order
corresponding to the sorted attribute names.
)",
.fun = prim_attrValues,
});
* A primitive operation `dependencyClosure' to do automatic dependency determination (e.g., finding the header files dependencies of a C file) in Nix low-level builds automatically. For instance, in the function `compileC' in make/lib/default.nix, we find the header file dependencies of C file `main' as follows: localIncludes = dependencyClosure { scanner = file: import (findIncludes { inherit file; }); startSet = [main]; }; The function works by "growing" the set of dependencies, starting with the set `startSet', and calling the function `scanner' for each file to get its dependencies (which should yield a list of strings representing relative paths). For instance, when `scanner' is called on a file `foo.c' that includes the line #include "../bar/fnord.h" then `scanner' should yield ["../bar/fnord.h"]. This list of dependencies is absolutised relative to the including file and added to the set of dependencies. The process continues until no more dependencies are found (hence its a closure). `dependencyClosure' yields a list that contains in alternation a dependency, and its relative path to the directory of the start file, e.g., [ /bla/bla/foo.c "foo.c" /bla/bar/fnord.h "../bar/fnord.h" ] These relative paths are necessary for the builder that compiles foo.c to reconstruct the relative directory structure expected by foo.c. The advantage of `dependencyClosure' over the old approach (using the impure `__currentTime') is that it's completely pure, and more efficient because it only rescans for dependencies (i.e., by building the derivations yielded by `scanner') if sources have actually changed. The old approach rescanned every time.
2005-08-14 12:38:47 +00:00
2007-01-29 15:11:32 +00:00
/* Dynamic version of the `.' operator. */
void prim_getAttr(EvalState & state, const Pos & pos, Value * * args, Value & v)
* A primitive operation `dependencyClosure' to do automatic dependency determination (e.g., finding the header files dependencies of a C file) in Nix low-level builds automatically. For instance, in the function `compileC' in make/lib/default.nix, we find the header file dependencies of C file `main' as follows: localIncludes = dependencyClosure { scanner = file: import (findIncludes { inherit file; }); startSet = [main]; }; The function works by "growing" the set of dependencies, starting with the set `startSet', and calling the function `scanner' for each file to get its dependencies (which should yield a list of strings representing relative paths). For instance, when `scanner' is called on a file `foo.c' that includes the line #include "../bar/fnord.h" then `scanner' should yield ["../bar/fnord.h"]. This list of dependencies is absolutised relative to the including file and added to the set of dependencies. The process continues until no more dependencies are found (hence its a closure). `dependencyClosure' yields a list that contains in alternation a dependency, and its relative path to the directory of the start file, e.g., [ /bla/bla/foo.c "foo.c" /bla/bar/fnord.h "../bar/fnord.h" ] These relative paths are necessary for the builder that compiles foo.c to reconstruct the relative directory structure expected by foo.c. The advantage of `dependencyClosure' over the old approach (using the impure `__currentTime') is that it's completely pure, and more efficient because it only rescans for dependencies (i.e., by building the derivations yielded by `scanner') if sources have actually changed. The old approach rescanned every time.
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{
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string attr = state.forceStringNoCtx(*args[0], pos);
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state.forceAttrs(*args[1], pos);
// !!! Should we create a symbol here or just do a lookup?
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Bindings::iterator i = getAttr(
state,
"getAttr",
attr,
args[1]->attrs,
pos
);
// !!! add to stack trace?
if (state.countCalls && i->pos) state.attrSelects[*i->pos]++;
state.forceValue(*i->value, pos);
v = *i->value;
2007-01-29 15:11:32 +00:00
}
* A primitive operation `dependencyClosure' to do automatic dependency determination (e.g., finding the header files dependencies of a C file) in Nix low-level builds automatically. For instance, in the function `compileC' in make/lib/default.nix, we find the header file dependencies of C file `main' as follows: localIncludes = dependencyClosure { scanner = file: import (findIncludes { inherit file; }); startSet = [main]; }; The function works by "growing" the set of dependencies, starting with the set `startSet', and calling the function `scanner' for each file to get its dependencies (which should yield a list of strings representing relative paths). For instance, when `scanner' is called on a file `foo.c' that includes the line #include "../bar/fnord.h" then `scanner' should yield ["../bar/fnord.h"]. This list of dependencies is absolutised relative to the including file and added to the set of dependencies. The process continues until no more dependencies are found (hence its a closure). `dependencyClosure' yields a list that contains in alternation a dependency, and its relative path to the directory of the start file, e.g., [ /bla/bla/foo.c "foo.c" /bla/bar/fnord.h "../bar/fnord.h" ] These relative paths are necessary for the builder that compiles foo.c to reconstruct the relative directory structure expected by foo.c. The advantage of `dependencyClosure' over the old approach (using the impure `__currentTime') is that it's completely pure, and more efficient because it only rescans for dependencies (i.e., by building the derivations yielded by `scanner') if sources have actually changed. The old approach rescanned every time.
2005-08-14 12:38:47 +00:00
static RegisterPrimOp primop_getAttr({
.name = "__getAttr",
.args = {"s", "set"},
.doc = R"(
`getAttr` returns the attribute named *s* from *set*. Evaluation
aborts if the attribute doesnt exist. This is a dynamic version of
the `.` operator, since *s* is an expression rather than an
identifier.
)",
.fun = prim_getAttr,
});
* A primitive operation `dependencyClosure' to do automatic dependency determination (e.g., finding the header files dependencies of a C file) in Nix low-level builds automatically. For instance, in the function `compileC' in make/lib/default.nix, we find the header file dependencies of C file `main' as follows: localIncludes = dependencyClosure { scanner = file: import (findIncludes { inherit file; }); startSet = [main]; }; The function works by "growing" the set of dependencies, starting with the set `startSet', and calling the function `scanner' for each file to get its dependencies (which should yield a list of strings representing relative paths). For instance, when `scanner' is called on a file `foo.c' that includes the line #include "../bar/fnord.h" then `scanner' should yield ["../bar/fnord.h"]. This list of dependencies is absolutised relative to the including file and added to the set of dependencies. The process continues until no more dependencies are found (hence its a closure). `dependencyClosure' yields a list that contains in alternation a dependency, and its relative path to the directory of the start file, e.g., [ /bla/bla/foo.c "foo.c" /bla/bar/fnord.h "../bar/fnord.h" ] These relative paths are necessary for the builder that compiles foo.c to reconstruct the relative directory structure expected by foo.c. The advantage of `dependencyClosure' over the old approach (using the impure `__currentTime') is that it's completely pure, and more efficient because it only rescans for dependencies (i.e., by building the derivations yielded by `scanner') if sources have actually changed. The old approach rescanned every time.
2005-08-14 12:38:47 +00:00
/* Return position information of the specified attribute. */
static void prim_unsafeGetAttrPos(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
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string attr = state.forceStringNoCtx(*args[0], pos);
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state.forceAttrs(*args[1], pos);
Bindings::iterator i = args[1]->attrs->find(state.symbols.create(attr));
if (i == args[1]->attrs->end())
mkNull(v);
else
state.mkPos(v, i->pos);
}
static RegisterPrimOp primop_unsafeGetAttrPos(RegisterPrimOp::Info {
.name = "__unsafeGetAttrPos",
.arity = 2,
.fun = prim_unsafeGetAttrPos,
});
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/* Dynamic version of the `?' operator. */
static void prim_hasAttr(EvalState & state, const Pos & pos, Value * * args, Value & v)
2007-01-29 15:11:32 +00:00
{
2014-04-04 19:14:11 +00:00
string attr = state.forceStringNoCtx(*args[0], pos);
2014-04-04 17:11:40 +00:00
state.forceAttrs(*args[1], pos);
mkBool(v, args[1]->attrs->find(state.symbols.create(attr)) != args[1]->attrs->end());
2007-01-29 15:11:32 +00:00
}
* A primitive operation `dependencyClosure' to do automatic dependency determination (e.g., finding the header files dependencies of a C file) in Nix low-level builds automatically. For instance, in the function `compileC' in make/lib/default.nix, we find the header file dependencies of C file `main' as follows: localIncludes = dependencyClosure { scanner = file: import (findIncludes { inherit file; }); startSet = [main]; }; The function works by "growing" the set of dependencies, starting with the set `startSet', and calling the function `scanner' for each file to get its dependencies (which should yield a list of strings representing relative paths). For instance, when `scanner' is called on a file `foo.c' that includes the line #include "../bar/fnord.h" then `scanner' should yield ["../bar/fnord.h"]. This list of dependencies is absolutised relative to the including file and added to the set of dependencies. The process continues until no more dependencies are found (hence its a closure). `dependencyClosure' yields a list that contains in alternation a dependency, and its relative path to the directory of the start file, e.g., [ /bla/bla/foo.c "foo.c" /bla/bar/fnord.h "../bar/fnord.h" ] These relative paths are necessary for the builder that compiles foo.c to reconstruct the relative directory structure expected by foo.c. The advantage of `dependencyClosure' over the old approach (using the impure `__currentTime') is that it's completely pure, and more efficient because it only rescans for dependencies (i.e., by building the derivations yielded by `scanner') if sources have actually changed. The old approach rescanned every time.
2005-08-14 12:38:47 +00:00
static RegisterPrimOp primop_hasAttr({
.name = "__hasAttr",
.args = {"s", "set"},
.doc = R"(
`hasAttr` returns `true` if *set* has an attribute named *s*, and
`false` otherwise. This is a dynamic version of the `?` operator,
since *s* is an expression rather than an identifier.
)",
.fun = prim_hasAttr,
});
/* Determine whether the argument is a set. */
static void prim_isAttrs(EvalState & state, const Pos & pos, Value * * args, Value & v)
2010-03-30 22:39:48 +00:00
{
state.forceValue(*args[0], pos);
mkBool(v, args[0]->type() == nAttrs);
2010-03-30 22:39:48 +00:00
}
static RegisterPrimOp primop_isAttrs({
.name = "__isAttrs",
.args = {"e"},
.doc = R"(
Return `true` if *e* evaluates to a set, and `false` otherwise.
)",
.fun = prim_isAttrs,
});
2010-03-30 22:39:48 +00:00
static void prim_removeAttrs(EvalState & state, const Pos & pos, Value * * args, Value & v)
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{
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state.forceAttrs(*args[0], pos);
2014-04-04 17:05:36 +00:00
state.forceList(*args[1], pos);
2010-03-30 22:39:48 +00:00
/* Get the attribute names to be removed. */
std::set<Symbol> names;
for (unsigned int i = 0; i < args[1]->listSize(); ++i) {
state.forceStringNoCtx(*args[1]->listElems()[i], pos);
names.insert(state.symbols.create(args[1]->listElems()[i]->string.s));
}
/* Copy all attributes not in that set. Note that we don't need
to sort v.attrs because it's a subset of an already sorted
vector. */
state.mkAttrs(v, args[0]->attrs->size());
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for (auto & i : *args[0]->attrs) {
if (names.find(i.name) == names.end())
v.attrs->push_back(i);
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}
}
static RegisterPrimOp primop_removeAttrs({
.name = "removeAttrs",
.args = {"set", "list"},
.doc = R"(
Remove the attributes listed in *list* from *set*. The attributes
dont have to exist in *set*. For instance,
```nix
removeAttrs { x = 1; y = 2; z = 3; } [ "a" "x" "z" ]
```
evaluates to `{ y = 2; }`.
)",
.fun = prim_removeAttrs,
});
2010-03-30 22:39:48 +00:00
/* Builds a set from a list specifying (name, value) pairs. To be
precise, a list [{name = "name1"; value = value1;} ... {name =
"nameN"; value = valueN;}] is transformed to {name1 = value1;
2013-10-28 06:34:44 +00:00
... nameN = valueN;}. In case of duplicate occurences of the same
name, the first takes precedence. */
static void prim_listToAttrs(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
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state.forceList(*args[0], pos);
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state.mkAttrs(v, args[0]->listSize());
2010-03-31 15:38:03 +00:00
std::set<Symbol> seen;
for (unsigned int i = 0; i < args[0]->listSize(); ++i) {
Value & v2(*args[0]->listElems()[i]);
2014-04-04 17:11:40 +00:00
state.forceAttrs(v2, pos);
2013-09-02 14:29:15 +00:00
2021-04-13 21:08:59 +00:00
Bindings::iterator j = getAttr(
state,
"listToAttrs",
state.sName,
v2.attrs,
pos
);
string name = state.forceStringNoCtx(*j->value, *j->pos);
2013-09-02 14:29:15 +00:00
Symbol sym = state.symbols.create(name);
if (seen.insert(sym).second) {
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Bindings::iterator j2 = getAttr(
state,
"listToAttrs",
state.sValue,
v2.attrs,
pos
);
v.attrs->push_back(Attr(sym, j2->value, j2->pos));
}
}
v.attrs->sort();
}
static RegisterPrimOp primop_listToAttrs({
.name = "__listToAttrs",
.args = {"e"},
.doc = R"(
Construct a set from a list specifying the names and values of each
attribute. Each element of the list should be a set consisting of a
string-valued attribute `name` specifying the name of the attribute,
and an attribute `value` specifying its value. Example:
```nix
builtins.listToAttrs
[ { name = "foo"; value = 123; }
{ name = "bar"; value = 456; }
]
```
evaluates to
```nix
{ foo = 123; bar = 456; }
```
)",
.fun = prim_listToAttrs,
});
2007-10-31 18:01:56 +00:00
static void prim_intersectAttrs(EvalState & state, const Pos & pos, Value * * args, Value & v)
* Two primops: builtins.intersectAttrs and builtins.functionArgs. intersectAttrs returns the (right-biased) intersection between two attribute sets, e.g. every attribute from the second set that also exists in the first. functionArgs returns the set of attributes expected by a function. The main goal of these is to allow the elimination of most of all-packages.nix. Most package instantiations in all-packages.nix have this form: foo = import ./foo.nix { inherit a b c; }; With intersectAttrs and functionArgs, this can be written as: foo = callPackage (import ./foo.nix) { }; where callPackage = f: args: f ((builtins.intersectAttrs (builtins.functionArgs f) pkgs) // args); I.e., foo.nix is called with all attributes from "pkgs" that it actually needs (e.g., pkgs.a, pkgs.b and pkgs.c). (callPackage can do any other generic package-level stuff we might want, such as applying makeOverridable.) Of course, the automatically supplied arguments can be overriden if needed, e.g. foo = callPackage (import ./foo.nix) { c = c_version_2; }; but for the vast majority of packages, this won't be needed. The advantages are to reduce the amount of typing needed to add a dependency (from three sites to two), and to reduce the number of trivial commits to all-packages.nix. For the former, there have been two previous attempts: - Use "args: with args;" in the package's function definition. This however obscures the actual expected arguments of a function, which is very bad. - Use "{ arg1, arg2, ... }:" in the package's function definition (i.e. use the ellipis "..." to allow arbitrary additional arguments), and then call the function with all of "pkgs" as an argument. But this inhibits error detection if you call it with an misspelled (or obsolete) argument.
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{
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state.forceAttrs(*args[0], pos);
state.forceAttrs(*args[1], pos);
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state.mkAttrs(v, std::min(args[0]->attrs->size(), args[1]->attrs->size()));
2015-07-17 17:24:28 +00:00
for (auto & i : *args[0]->attrs) {
Bindings::iterator j = args[1]->attrs->find(i.name);
if (j != args[1]->attrs->end())
v.attrs->push_back(*j);
* Two primops: builtins.intersectAttrs and builtins.functionArgs. intersectAttrs returns the (right-biased) intersection between two attribute sets, e.g. every attribute from the second set that also exists in the first. functionArgs returns the set of attributes expected by a function. The main goal of these is to allow the elimination of most of all-packages.nix. Most package instantiations in all-packages.nix have this form: foo = import ./foo.nix { inherit a b c; }; With intersectAttrs and functionArgs, this can be written as: foo = callPackage (import ./foo.nix) { }; where callPackage = f: args: f ((builtins.intersectAttrs (builtins.functionArgs f) pkgs) // args); I.e., foo.nix is called with all attributes from "pkgs" that it actually needs (e.g., pkgs.a, pkgs.b and pkgs.c). (callPackage can do any other generic package-level stuff we might want, such as applying makeOverridable.) Of course, the automatically supplied arguments can be overriden if needed, e.g. foo = callPackage (import ./foo.nix) { c = c_version_2; }; but for the vast majority of packages, this won't be needed. The advantages are to reduce the amount of typing needed to add a dependency (from three sites to two), and to reduce the number of trivial commits to all-packages.nix. For the former, there have been two previous attempts: - Use "args: with args;" in the package's function definition. This however obscures the actual expected arguments of a function, which is very bad. - Use "{ arg1, arg2, ... }:" in the package's function definition (i.e. use the ellipis "..." to allow arbitrary additional arguments), and then call the function with all of "pkgs" as an argument. But this inhibits error detection if you call it with an misspelled (or obsolete) argument.
2009-09-15 13:01:46 +00:00
}
}
static RegisterPrimOp primop_intersectAttrs({
.name = "__intersectAttrs",
.args = {"e1", "e2"},
.doc = R"(
Return a set consisting of the attributes in the set *e2* that also
exist in the set *e1*.
)",
.fun = prim_intersectAttrs,
});
* Two primops: builtins.intersectAttrs and builtins.functionArgs. intersectAttrs returns the (right-biased) intersection between two attribute sets, e.g. every attribute from the second set that also exists in the first. functionArgs returns the set of attributes expected by a function. The main goal of these is to allow the elimination of most of all-packages.nix. Most package instantiations in all-packages.nix have this form: foo = import ./foo.nix { inherit a b c; }; With intersectAttrs and functionArgs, this can be written as: foo = callPackage (import ./foo.nix) { }; where callPackage = f: args: f ((builtins.intersectAttrs (builtins.functionArgs f) pkgs) // args); I.e., foo.nix is called with all attributes from "pkgs" that it actually needs (e.g., pkgs.a, pkgs.b and pkgs.c). (callPackage can do any other generic package-level stuff we might want, such as applying makeOverridable.) Of course, the automatically supplied arguments can be overriden if needed, e.g. foo = callPackage (import ./foo.nix) { c = c_version_2; }; but for the vast majority of packages, this won't be needed. The advantages are to reduce the amount of typing needed to add a dependency (from three sites to two), and to reduce the number of trivial commits to all-packages.nix. For the former, there have been two previous attempts: - Use "args: with args;" in the package's function definition. This however obscures the actual expected arguments of a function, which is very bad. - Use "{ arg1, arg2, ... }:" in the package's function definition (i.e. use the ellipis "..." to allow arbitrary additional arguments), and then call the function with all of "pkgs" as an argument. But this inhibits error detection if you call it with an misspelled (or obsolete) argument.
2009-09-15 13:01:46 +00:00
2014-10-04 16:15:03 +00:00
static void prim_catAttrs(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
Symbol attrName = state.symbols.create(state.forceStringNoCtx(*args[0], pos));
state.forceList(*args[1], pos);
Value * res[args[1]->listSize()];
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unsigned int found = 0;
for (unsigned int n = 0; n < args[1]->listSize(); ++n) {
Value & v2(*args[1]->listElems()[n]);
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state.forceAttrs(v2, pos);
Bindings::iterator i = v2.attrs->find(attrName);
if (i != v2.attrs->end())
res[found++] = i->value;
}
state.mkList(v, found);
for (unsigned int n = 0; n < found; ++n)
v.listElems()[n] = res[n];
2014-10-04 16:15:03 +00:00
}
2020-08-25 09:16:45 +00:00
static RegisterPrimOp primop_catAttrs({
.name = "__catAttrs",
.args = {"attr", "list"},
.doc = R"(
Collect each attribute named *attr* from a list of attribute
sets. Attrsets that don't contain the named attribute are
ignored. For example,
2014-10-04 16:15:03 +00:00
2020-08-25 09:16:45 +00:00
```nix
builtins.catAttrs "a" [{a = 1;} {b = 0;} {a = 2;}]
```
* Two primops: builtins.intersectAttrs and builtins.functionArgs. intersectAttrs returns the (right-biased) intersection between two attribute sets, e.g. every attribute from the second set that also exists in the first. functionArgs returns the set of attributes expected by a function. The main goal of these is to allow the elimination of most of all-packages.nix. Most package instantiations in all-packages.nix have this form: foo = import ./foo.nix { inherit a b c; }; With intersectAttrs and functionArgs, this can be written as: foo = callPackage (import ./foo.nix) { }; where callPackage = f: args: f ((builtins.intersectAttrs (builtins.functionArgs f) pkgs) // args); I.e., foo.nix is called with all attributes from "pkgs" that it actually needs (e.g., pkgs.a, pkgs.b and pkgs.c). (callPackage can do any other generic package-level stuff we might want, such as applying makeOverridable.) Of course, the automatically supplied arguments can be overriden if needed, e.g. foo = callPackage (import ./foo.nix) { c = c_version_2; }; but for the vast majority of packages, this won't be needed. The advantages are to reduce the amount of typing needed to add a dependency (from three sites to two), and to reduce the number of trivial commits to all-packages.nix. For the former, there have been two previous attempts: - Use "args: with args;" in the package's function definition. This however obscures the actual expected arguments of a function, which is very bad. - Use "{ arg1, arg2, ... }:" in the package's function definition (i.e. use the ellipis "..." to allow arbitrary additional arguments), and then call the function with all of "pkgs" as an argument. But this inhibits error detection if you call it with an misspelled (or obsolete) argument.
2009-09-15 13:01:46 +00:00
2020-08-25 09:16:45 +00:00
evaluates to `[1 2]`.
)",
.fun = prim_catAttrs,
});
* Two primops: builtins.intersectAttrs and builtins.functionArgs. intersectAttrs returns the (right-biased) intersection between two attribute sets, e.g. every attribute from the second set that also exists in the first. functionArgs returns the set of attributes expected by a function. The main goal of these is to allow the elimination of most of all-packages.nix. Most package instantiations in all-packages.nix have this form: foo = import ./foo.nix { inherit a b c; }; With intersectAttrs and functionArgs, this can be written as: foo = callPackage (import ./foo.nix) { }; where callPackage = f: args: f ((builtins.intersectAttrs (builtins.functionArgs f) pkgs) // args); I.e., foo.nix is called with all attributes from "pkgs" that it actually needs (e.g., pkgs.a, pkgs.b and pkgs.c). (callPackage can do any other generic package-level stuff we might want, such as applying makeOverridable.) Of course, the automatically supplied arguments can be overriden if needed, e.g. foo = callPackage (import ./foo.nix) { c = c_version_2; }; but for the vast majority of packages, this won't be needed. The advantages are to reduce the amount of typing needed to add a dependency (from three sites to two), and to reduce the number of trivial commits to all-packages.nix. For the former, there have been two previous attempts: - Use "args: with args;" in the package's function definition. This however obscures the actual expected arguments of a function, which is very bad. - Use "{ arg1, arg2, ... }:" in the package's function definition (i.e. use the ellipis "..." to allow arbitrary additional arguments), and then call the function with all of "pkgs" as an argument. But this inhibits error detection if you call it with an misspelled (or obsolete) argument.
2009-09-15 13:01:46 +00:00
static void prim_functionArgs(EvalState & state, const Pos & pos, Value * * args, Value & v)
* Two primops: builtins.intersectAttrs and builtins.functionArgs. intersectAttrs returns the (right-biased) intersection between two attribute sets, e.g. every attribute from the second set that also exists in the first. functionArgs returns the set of attributes expected by a function. The main goal of these is to allow the elimination of most of all-packages.nix. Most package instantiations in all-packages.nix have this form: foo = import ./foo.nix { inherit a b c; }; With intersectAttrs and functionArgs, this can be written as: foo = callPackage (import ./foo.nix) { }; where callPackage = f: args: f ((builtins.intersectAttrs (builtins.functionArgs f) pkgs) // args); I.e., foo.nix is called with all attributes from "pkgs" that it actually needs (e.g., pkgs.a, pkgs.b and pkgs.c). (callPackage can do any other generic package-level stuff we might want, such as applying makeOverridable.) Of course, the automatically supplied arguments can be overriden if needed, e.g. foo = callPackage (import ./foo.nix) { c = c_version_2; }; but for the vast majority of packages, this won't be needed. The advantages are to reduce the amount of typing needed to add a dependency (from three sites to two), and to reduce the number of trivial commits to all-packages.nix. For the former, there have been two previous attempts: - Use "args: with args;" in the package's function definition. This however obscures the actual expected arguments of a function, which is very bad. - Use "{ arg1, arg2, ... }:" in the package's function definition (i.e. use the ellipis "..." to allow arbitrary additional arguments), and then call the function with all of "pkgs" as an argument. But this inhibits error detection if you call it with an misspelled (or obsolete) argument.
2009-09-15 13:01:46 +00:00
{
state.forceValue(*args[0], pos);
if (args[0]->isPrimOpApp() || args[0]->isPrimOp()) {
state.mkAttrs(v, 0);
return;
}
if (!args[0]->isLambda())
throw TypeError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("'functionArgs' requires a function"),
.errPos = pos
});
* Two primops: builtins.intersectAttrs and builtins.functionArgs. intersectAttrs returns the (right-biased) intersection between two attribute sets, e.g. every attribute from the second set that also exists in the first. functionArgs returns the set of attributes expected by a function. The main goal of these is to allow the elimination of most of all-packages.nix. Most package instantiations in all-packages.nix have this form: foo = import ./foo.nix { inherit a b c; }; With intersectAttrs and functionArgs, this can be written as: foo = callPackage (import ./foo.nix) { }; where callPackage = f: args: f ((builtins.intersectAttrs (builtins.functionArgs f) pkgs) // args); I.e., foo.nix is called with all attributes from "pkgs" that it actually needs (e.g., pkgs.a, pkgs.b and pkgs.c). (callPackage can do any other generic package-level stuff we might want, such as applying makeOverridable.) Of course, the automatically supplied arguments can be overriden if needed, e.g. foo = callPackage (import ./foo.nix) { c = c_version_2; }; but for the vast majority of packages, this won't be needed. The advantages are to reduce the amount of typing needed to add a dependency (from three sites to two), and to reduce the number of trivial commits to all-packages.nix. For the former, there have been two previous attempts: - Use "args: with args;" in the package's function definition. This however obscures the actual expected arguments of a function, which is very bad. - Use "{ arg1, arg2, ... }:" in the package's function definition (i.e. use the ellipis "..." to allow arbitrary additional arguments), and then call the function with all of "pkgs" as an argument. But this inhibits error detection if you call it with an misspelled (or obsolete) argument.
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if (!args[0]->lambda.fun->matchAttrs) {
state.mkAttrs(v, 0);
return;
}
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state.mkAttrs(v, args[0]->lambda.fun->formals->formals.size());
for (auto & i : args[0]->lambda.fun->formals->formals) {
// !!! should optimise booleans (allocate only once)
Value * value = state.allocValue();
v.attrs->push_back(Attr(i.name, value, &i.pos));
mkBool(*value, i.def);
}
v.attrs->sort();
* Two primops: builtins.intersectAttrs and builtins.functionArgs. intersectAttrs returns the (right-biased) intersection between two attribute sets, e.g. every attribute from the second set that also exists in the first. functionArgs returns the set of attributes expected by a function. The main goal of these is to allow the elimination of most of all-packages.nix. Most package instantiations in all-packages.nix have this form: foo = import ./foo.nix { inherit a b c; }; With intersectAttrs and functionArgs, this can be written as: foo = callPackage (import ./foo.nix) { }; where callPackage = f: args: f ((builtins.intersectAttrs (builtins.functionArgs f) pkgs) // args); I.e., foo.nix is called with all attributes from "pkgs" that it actually needs (e.g., pkgs.a, pkgs.b and pkgs.c). (callPackage can do any other generic package-level stuff we might want, such as applying makeOverridable.) Of course, the automatically supplied arguments can be overriden if needed, e.g. foo = callPackage (import ./foo.nix) { c = c_version_2; }; but for the vast majority of packages, this won't be needed. The advantages are to reduce the amount of typing needed to add a dependency (from three sites to two), and to reduce the number of trivial commits to all-packages.nix. For the former, there have been two previous attempts: - Use "args: with args;" in the package's function definition. This however obscures the actual expected arguments of a function, which is very bad. - Use "{ arg1, arg2, ... }:" in the package's function definition (i.e. use the ellipis "..." to allow arbitrary additional arguments), and then call the function with all of "pkgs" as an argument. But this inhibits error detection if you call it with an misspelled (or obsolete) argument.
2009-09-15 13:01:46 +00:00
}
static RegisterPrimOp primop_functionArgs({
.name = "__functionArgs",
.args = {"f"},
.doc = R"(
Return a set containing the names of the formal arguments expected
by the function *f*. The value of each attribute is a Boolean
denoting whether the corresponding argument has a default value. For
instance, `functionArgs ({ x, y ? 123}: ...) = { x = false; y =
true; }`.
"Formal argument" here refers to the attributes pattern-matched by
the function. Plain lambdas are not included, e.g. `functionArgs (x:
...) = { }`.
)",
.fun = prim_functionArgs,
});
* Two primops: builtins.intersectAttrs and builtins.functionArgs. intersectAttrs returns the (right-biased) intersection between two attribute sets, e.g. every attribute from the second set that also exists in the first. functionArgs returns the set of attributes expected by a function. The main goal of these is to allow the elimination of most of all-packages.nix. Most package instantiations in all-packages.nix have this form: foo = import ./foo.nix { inherit a b c; }; With intersectAttrs and functionArgs, this can be written as: foo = callPackage (import ./foo.nix) { }; where callPackage = f: args: f ((builtins.intersectAttrs (builtins.functionArgs f) pkgs) // args); I.e., foo.nix is called with all attributes from "pkgs" that it actually needs (e.g., pkgs.a, pkgs.b and pkgs.c). (callPackage can do any other generic package-level stuff we might want, such as applying makeOverridable.) Of course, the automatically supplied arguments can be overriden if needed, e.g. foo = callPackage (import ./foo.nix) { c = c_version_2; }; but for the vast majority of packages, this won't be needed. The advantages are to reduce the amount of typing needed to add a dependency (from three sites to two), and to reduce the number of trivial commits to all-packages.nix. For the former, there have been two previous attempts: - Use "args: with args;" in the package's function definition. This however obscures the actual expected arguments of a function, which is very bad. - Use "{ arg1, arg2, ... }:" in the package's function definition (i.e. use the ellipis "..." to allow arbitrary additional arguments), and then call the function with all of "pkgs" as an argument. But this inhibits error detection if you call it with an misspelled (or obsolete) argument.
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/* */
static void prim_mapAttrs(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceAttrs(*args[1], pos);
state.mkAttrs(v, args[1]->attrs->size());
for (auto & i : *args[1]->attrs) {
Value * vName = state.allocValue();
Value * vFun2 = state.allocValue();
mkString(*vName, i.name);
mkApp(*vFun2, *args[0], *vName);
mkApp(*state.allocAttr(v, i.name), *vFun2, *i.value);
}
}
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static RegisterPrimOp primop_mapAttrs({
.name = "__mapAttrs",
.args = {"f", "attrset"},
.doc = R"(
Apply function *f* to every element of *attrset*. For example,
```nix
builtins.mapAttrs (name: value: value * 10) { a = 1; b = 2; }
```
evaluates to `{ a = 10; b = 20; }`.
)",
.fun = prim_mapAttrs,
});
2007-01-29 15:11:32 +00:00
/*************************************************************
* Lists
*************************************************************/
* A primitive operation `dependencyClosure' to do automatic dependency determination (e.g., finding the header files dependencies of a C file) in Nix low-level builds automatically. For instance, in the function `compileC' in make/lib/default.nix, we find the header file dependencies of C file `main' as follows: localIncludes = dependencyClosure { scanner = file: import (findIncludes { inherit file; }); startSet = [main]; }; The function works by "growing" the set of dependencies, starting with the set `startSet', and calling the function `scanner' for each file to get its dependencies (which should yield a list of strings representing relative paths). For instance, when `scanner' is called on a file `foo.c' that includes the line #include "../bar/fnord.h" then `scanner' should yield ["../bar/fnord.h"]. This list of dependencies is absolutised relative to the including file and added to the set of dependencies. The process continues until no more dependencies are found (hence its a closure). `dependencyClosure' yields a list that contains in alternation a dependency, and its relative path to the directory of the start file, e.g., [ /bla/bla/foo.c "foo.c" /bla/bar/fnord.h "../bar/fnord.h" ] These relative paths are necessary for the builder that compiles foo.c to reconstruct the relative directory structure expected by foo.c. The advantage of `dependencyClosure' over the old approach (using the impure `__currentTime') is that it's completely pure, and more efficient because it only rescans for dependencies (i.e., by building the derivations yielded by `scanner') if sources have actually changed. The old approach rescanned every time.
2005-08-14 12:38:47 +00:00
2007-01-29 15:11:32 +00:00
/* Determine whether the argument is a list. */
static void prim_isList(EvalState & state, const Pos & pos, Value * * args, Value & v)
2006-08-23 15:46:00 +00:00
{
state.forceValue(*args[0], pos);
mkBool(v, args[0]->type() == nList);
2006-08-23 15:46:00 +00:00
}
static RegisterPrimOp primop_isList({
.name = "__isList",
.args = {"e"},
.doc = R"(
Return `true` if *e* evaluates to a list, and `false` otherwise.
)",
.fun = prim_isList,
});
2006-08-23 15:46:00 +00:00
static void elemAt(EvalState & state, const Pos & pos, Value & list, int n, Value & v)
{
2014-04-04 17:05:36 +00:00
state.forceList(list, pos);
if (n < 0 || (unsigned int) n >= list.listSize())
throw Error({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("list index %1% is out of bounds", n),
.errPos = pos
});
state.forceValue(*list.listElems()[n], pos);
v = *list.listElems()[n];
}
/* Return the n-1'th element of a list. */
static void prim_elemAt(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
2014-04-04 16:58:15 +00:00
elemAt(state, pos, *args[0], state.forceInt(*args[1], pos), v);
}
static RegisterPrimOp primop_elemAt({
.name = "__elemAt",
.args = {"xs", "n"},
.doc = R"(
Return element *n* from the list *xs*. Elements are counted starting
from 0. A fatal error occurs if the index is out of bounds.
)",
.fun = prim_elemAt,
});
/* Return the first element of a list. */
static void prim_head(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
elemAt(state, pos, *args[0], 0, v);
}
static RegisterPrimOp primop_head({
.name = "__head",
.args = {"list"},
.doc = R"(
Return the first element of a list; abort evaluation if the argument
isnt a list or is an empty list. You can test whether a list is
empty by comparing it with `[]`.
)",
.fun = prim_head,
});
2015-03-06 15:39:48 +00:00
/* Return a list consisting of everything but the first element of
a list. Warning: this function takes O(n) time, so you probably
don't want to use it! */
static void prim_tail(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
2014-04-04 17:05:36 +00:00
state.forceList(*args[0], pos);
if (args[0]->listSize() == 0)
throw Error({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("'tail' called on an empty list"),
.errPos = pos
});
state.mkList(v, args[0]->listSize() - 1);
for (unsigned int n = 0; n < v.listSize(); ++n)
v.listElems()[n] = args[0]->listElems()[n + 1];
}
static RegisterPrimOp primop_tail({
.name = "__tail",
.args = {"list"},
.doc = R"(
Return the second to last elements of a list; abort evaluation if
the argument isnt a list or is an empty list.
> **Warning**
>
> This function should generally be avoided since it's inefficient:
> unlike Haskell's `tail`, it takes O(n) time, so recursing over a
> list by repeatedly calling `tail` takes O(n^2) time.
)",
.fun = prim_tail,
});
/* Apply a function to every element of a list. */
static void prim_map(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
2014-04-04 17:05:36 +00:00
state.forceList(*args[1], pos);
state.mkList(v, args[1]->listSize());
for (unsigned int n = 0; n < v.listSize(); ++n)
mkApp(*(v.listElems()[n] = state.allocValue()),
*args[0], *args[1]->listElems()[n]);
}
static RegisterPrimOp primop_map({
.name = "map",
.args = {"f", "list"},
.doc = R"(
Apply the function *f* to each element in the list *list*. For
example,
```nix
map (x: "foo" + x) [ "bar" "bla" "abc" ]
```
evaluates to `[ "foobar" "foobla" "fooabc" ]`.
)",
.fun = prim_map,
});
/* Filter a list using a predicate; that is, return a list containing
every element from the list for which the predicate function
returns true. */
static void prim_filter(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
2014-04-04 17:05:36 +00:00
state.forceFunction(*args[0], pos);
state.forceList(*args[1], pos);
// FIXME: putting this on the stack is risky.
Value * vs[args[1]->listSize()];
unsigned int k = 0;
2012-12-04 16:22:20 +00:00
bool same = true;
for (unsigned int n = 0; n < args[1]->listSize(); ++n) {
Value res;
state.callFunction(*args[0], *args[1]->listElems()[n], res, noPos);
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if (state.forceBool(res, pos))
vs[k++] = args[1]->listElems()[n];
2012-12-04 16:22:20 +00:00
else
same = false;
}
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if (same)
v = *args[1];
else {
state.mkList(v, k);
for (unsigned int n = 0; n < k; ++n) v.listElems()[n] = vs[n];
2012-12-04 16:22:20 +00:00
}
}
static RegisterPrimOp primop_filter({
.name = "__filter",
.args = {"f", "list"},
.doc = R"(
Return a list consisting of the elements of *list* for which the
function *f* returns `true`.
)",
.fun = prim_filter,
});
/* Return true if a list contains a given element. */
static void prim_elem(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
bool res = false;
2014-04-04 17:05:36 +00:00
state.forceList(*args[1], pos);
for (unsigned int n = 0; n < args[1]->listSize(); ++n)
if (state.eqValues(*args[0], *args[1]->listElems()[n])) {
res = true;
break;
}
mkBool(v, res);
}
static RegisterPrimOp primop_elem({
.name = "__elem",
.args = {"x", "xs"},
.doc = R"(
Return `true` if a value equal to *x* occurs in the list *xs*, and
`false` otherwise.
)",
.fun = prim_elem,
});
/* Concatenate a list of lists. */
static void prim_concatLists(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
2014-04-04 17:05:36 +00:00
state.forceList(*args[0], pos);
state.concatLists(v, args[0]->listSize(), args[0]->listElems(), pos);
}
static RegisterPrimOp primop_concatLists({
.name = "__concatLists",
.args = {"lists"},
.doc = R"(
Concatenate a list of lists into a single list.
)",
.fun = prim_concatLists,
});
/* Return the length of a list. This is an O(1) time operation. */
static void prim_length(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
2014-04-04 17:05:36 +00:00
state.forceList(*args[0], pos);
mkInt(v, args[0]->listSize());
}
static RegisterPrimOp primop_length({
.name = "__length",
.args = {"e"},
.doc = R"(
Return the length of the list *e*.
)",
.fun = prim_length,
});
2015-07-23 15:03:02 +00:00
/* Reduce a list by applying a binary operator, from left to
right. The operator is applied strictly. */
static void prim_foldlStrict(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceFunction(*args[0], pos);
state.forceList(*args[2], pos);
if (args[2]->listSize()) {
Value * vCur = args[1];
2015-07-23 15:03:02 +00:00
for (unsigned int n = 0; n < args[2]->listSize(); ++n) {
2015-07-23 15:03:02 +00:00
Value vTmp;
state.callFunction(*args[0], *vCur, vTmp, pos);
vCur = n == args[2]->listSize() - 1 ? &v : state.allocValue();
state.callFunction(vTmp, *args[2]->listElems()[n], *vCur, pos);
2015-07-23 15:03:02 +00:00
}
state.forceValue(v, pos);
} else {
state.forceValue(*args[1], pos);
v = *args[1];
}
2015-07-23 15:03:02 +00:00
}
static RegisterPrimOp primop_foldlStrict({
.name = "__foldl'",
.args = {"op", "nul", "list"},
.doc = R"(
Reduce a list by applying a binary operator, from left to right,
e.g. `foldl op nul [x0 x1 x2 ...] = op (op (op nul x0) x1) x2)
...`. The operator is applied strictly, i.e., its arguments are
evaluated first. For example, `foldl (x: y: x + y) 0 [1 2 3]`
evaluates to 6.
)",
.fun = prim_foldlStrict,
});
2015-07-23 15:03:02 +00:00
static void anyOrAll(bool any, EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceFunction(*args[0], pos);
state.forceList(*args[1], pos);
Value vTmp;
for (unsigned int n = 0; n < args[1]->listSize(); ++n) {
state.callFunction(*args[0], *args[1]->listElems()[n], vTmp, pos);
2016-08-29 15:56:35 +00:00
bool res = state.forceBool(vTmp, pos);
if (res == any) {
mkBool(v, any);
return;
}
}
mkBool(v, !any);
}
static void prim_any(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
anyOrAll(true, state, pos, args, v);
}
static RegisterPrimOp primop_any({
.name = "__any",
.args = {"pred", "list"},
.doc = R"(
Return `true` if the function *pred* returns `true` for at least one
element of *list*, and `false` otherwise.
)",
.fun = prim_any,
});
static void prim_all(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
anyOrAll(false, state, pos, args, v);
}
static RegisterPrimOp primop_all({
.name = "__all",
.args = {"pred", "list"},
.doc = R"(
Return `true` if the function *pred* returns `true` for all elements
of *list*, and `false` otherwise.
)",
.fun = prim_all,
});
static void prim_genList(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
auto len = state.forceInt(*args[1], pos);
if (len < 0)
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("cannot create list of size %1%", len),
.errPos = pos
});
state.mkList(v, len);
2016-01-07 13:37:39 +00:00
for (unsigned int n = 0; n < (unsigned int) len; ++n) {
Value * arg = state.allocValue();
mkInt(*arg, n);
mkApp(*(v.listElems()[n] = state.allocValue()), *args[0], *arg);
}
}
static RegisterPrimOp primop_genList({
.name = "__genList",
.args = {"generator", "length"},
.doc = R"(
Generate list of size *length*, with each element *i* equal to the
value returned by *generator* `i`. For example,
```nix
builtins.genList (x: x * x) 5
```
returns the list `[ 0 1 4 9 16 ]`.
)",
.fun = prim_genList,
});
2015-07-28 16:39:00 +00:00
static void prim_lessThan(EvalState & state, const Pos & pos, Value * * args, Value & v);
static void prim_sort(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceFunction(*args[0], pos);
state.forceList(*args[1], pos);
auto len = args[1]->listSize();
state.mkList(v, len);
for (unsigned int n = 0; n < len; ++n) {
state.forceValue(*args[1]->listElems()[n], pos);
2015-07-28 16:39:00 +00:00
v.listElems()[n] = args[1]->listElems()[n];
}
auto comparator = [&](Value * a, Value * b) {
/* Optimization: if the comparator is lessThan, bypass
callFunction. */
if (args[0]->isPrimOp() && args[0]->primOp->fun == prim_lessThan)
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return CompareValues()(a, b);
Value vTmp1, vTmp2;
state.callFunction(*args[0], *a, vTmp1, pos);
state.callFunction(vTmp1, *b, vTmp2, pos);
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return state.forceBool(vTmp2, pos);
2015-07-28 16:39:00 +00:00
};
/* FIXME: std::sort can segfault if the comparator is not a strict
weak ordering. What to do? std::stable_sort() seems more
resilient, but no guarantees... */
std::stable_sort(v.listElems(), v.listElems() + len, comparator);
}
static RegisterPrimOp primop_sort({
.name = "__sort",
.args = {"comparator", "list"},
.doc = R"(
Return *list* in sorted order. It repeatedly calls the function
*comparator* with two elements. The comparator should return `true`
if the first element is less than the second, and `false` otherwise.
For example,
```nix
builtins.sort builtins.lessThan [ 483 249 526 147 42 77 ]
```
produces the list `[ 42 77 147 249 483 526 ]`.
This is a stable sort: it preserves the relative order of elements
deemed equal by the comparator.
)",
.fun = prim_sort,
});
2015-07-28 16:39:00 +00:00
static void prim_partition(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceFunction(*args[0], pos);
state.forceList(*args[1], pos);
auto len = args[1]->listSize();
ValueVector right, wrong;
for (unsigned int n = 0; n < len; ++n) {
auto vElem = args[1]->listElems()[n];
state.forceValue(*vElem, pos);
Value res;
state.callFunction(*args[0], *vElem, res, pos);
2016-08-29 15:56:35 +00:00
if (state.forceBool(res, pos))
right.push_back(vElem);
else
wrong.push_back(vElem);
}
state.mkAttrs(v, 2);
Value * vRight = state.allocAttr(v, state.sRight);
auto rsize = right.size();
state.mkList(*vRight, rsize);
if (rsize)
memcpy(vRight->listElems(), right.data(), sizeof(Value *) * rsize);
Value * vWrong = state.allocAttr(v, state.sWrong);
auto wsize = wrong.size();
state.mkList(*vWrong, wsize);
if (wsize)
memcpy(vWrong->listElems(), wrong.data(), sizeof(Value *) * wsize);
v.attrs->sort();
}
2020-08-25 09:16:45 +00:00
static RegisterPrimOp primop_partition({
.name = "__partition",
.args = {"pred", "list"},
.doc = R"(
Given a predicate function *pred*, this function returns an
attrset containing a list named `right`, containing the elements
in *list* for which *pred* returned `true`, and a list named
`wrong`, containing the elements for which it returned
`false`. For example,
```nix
builtins.partition (x: x > 10) [1 23 9 3 42]
```
evaluates to
```nix
{ right = [ 23 42 ]; wrong = [ 1 9 3 ]; }
```
)",
.fun = prim_partition,
});
static void prim_concatMap(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceFunction(*args[0], pos);
state.forceList(*args[1], pos);
auto nrLists = args[1]->listSize();
Value lists[nrLists];
size_t len = 0;
for (unsigned int n = 0; n < nrLists; ++n) {
Value * vElem = args[1]->listElems()[n];
state.callFunction(*args[0], *vElem, lists[n], pos);
try {
state.forceList(lists[n], lists[n].determinePos(args[0]->determinePos(pos)));
} catch (TypeError &e) {
e.addTrace(pos, hintfmt("while invoking '%s'", "concatMap"));
throw e;
}
len += lists[n].listSize();
}
state.mkList(v, len);
auto out = v.listElems();
for (unsigned int n = 0, pos = 0; n < nrLists; ++n) {
auto l = lists[n].listSize();
if (l)
memcpy(out + pos, lists[n].listElems(), l * sizeof(Value *));
pos += l;
}
}
2020-08-25 09:16:45 +00:00
static RegisterPrimOp primop_concatMap({
.name = "__concatMap",
.args = {"f", "list"},
.doc = R"(
This function is equivalent to `builtins.concatLists (map f list)`
but is more efficient.
)",
.fun = prim_concatMap,
});
2007-01-29 15:11:32 +00:00
/*************************************************************
* Integer arithmetic
*************************************************************/
static void prim_add(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceValue(*args[0], pos);
state.forceValue(*args[1], pos);
if (args[0]->type() == nFloat || args[1]->type() == nFloat)
mkFloat(v, state.forceFloat(*args[0], pos) + state.forceFloat(*args[1], pos));
else
mkInt(v, state.forceInt(*args[0], pos) + state.forceInt(*args[1], pos));
}
static RegisterPrimOp primop_add({
.name = "__add",
.args = {"e1", "e2"},
.doc = R"(
Return the sum of the numbers *e1* and *e2*.
)",
.fun = prim_add,
});
static void prim_sub(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceValue(*args[0], pos);
state.forceValue(*args[1], pos);
if (args[0]->type() == nFloat || args[1]->type() == nFloat)
mkFloat(v, state.forceFloat(*args[0], pos) - state.forceFloat(*args[1], pos));
else
mkInt(v, state.forceInt(*args[0], pos) - state.forceInt(*args[1], pos));
}
static RegisterPrimOp primop_sub({
.name = "__sub",
.args = {"e1", "e2"},
.doc = R"(
Return the difference between the numbers *e1* and *e2*.
)",
.fun = prim_sub,
});
static void prim_mul(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceValue(*args[0], pos);
state.forceValue(*args[1], pos);
if (args[0]->type() == nFloat || args[1]->type() == nFloat)
mkFloat(v, state.forceFloat(*args[0], pos) * state.forceFloat(*args[1], pos));
else
mkInt(v, state.forceInt(*args[0], pos) * state.forceInt(*args[1], pos));
}
static RegisterPrimOp primop_mul({
.name = "__mul",
.args = {"e1", "e2"},
.doc = R"(
Return the product of the numbers *e1* and *e2*.
)",
.fun = prim_mul,
});
static void prim_div(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceValue(*args[0], pos);
state.forceValue(*args[1], pos);
NixFloat f2 = state.forceFloat(*args[1], pos);
if (f2 == 0)
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("division by zero"),
.errPos = pos
});
if (args[0]->type() == nFloat || args[1]->type() == nFloat) {
mkFloat(v, state.forceFloat(*args[0], pos) / state.forceFloat(*args[1], pos));
} else {
NixInt i1 = state.forceInt(*args[0], pos);
NixInt i2 = state.forceInt(*args[1], pos);
/* Avoid division overflow as it might raise SIGFPE. */
if (i1 == std::numeric_limits<NixInt>::min() && i2 == -1)
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("overflow in integer division"),
.errPos = pos
});
mkInt(v, i1 / i2);
}
}
static RegisterPrimOp primop_div({
.name = "__div",
.args = {"e1", "e2"},
.doc = R"(
Return the quotient of the numbers *e1* and *e2*.
)",
.fun = prim_div,
});
static void prim_bitAnd(EvalState & state, const Pos & pos, Value * * args, Value & v)
2018-05-12 16:50:39 +00:00
{
mkInt(v, state.forceInt(*args[0], pos) & state.forceInt(*args[1], pos));
}
static RegisterPrimOp primop_bitAnd({
.name = "__bitAnd",
.args = {"e1", "e2"},
.doc = R"(
Return the bitwise AND of the integers *e1* and *e2*.
)",
.fun = prim_bitAnd,
});
static void prim_bitOr(EvalState & state, const Pos & pos, Value * * args, Value & v)
2018-05-12 16:50:39 +00:00
{
mkInt(v, state.forceInt(*args[0], pos) | state.forceInt(*args[1], pos));
}
static RegisterPrimOp primop_bitOr({
.name = "__bitOr",
.args = {"e1", "e2"},
.doc = R"(
Return the bitwise OR of the integers *e1* and *e2*.
)",
.fun = prim_bitOr,
});
static void prim_bitXor(EvalState & state, const Pos & pos, Value * * args, Value & v)
2018-05-12 16:50:39 +00:00
{
mkInt(v, state.forceInt(*args[0], pos) ^ state.forceInt(*args[1], pos));
}
static RegisterPrimOp primop_bitXor({
.name = "__bitXor",
.args = {"e1", "e2"},
.doc = R"(
Return the bitwise XOR of the integers *e1* and *e2*.
)",
.fun = prim_bitXor,
});
static void prim_lessThan(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceValue(*args[0], pos);
state.forceValue(*args[1], pos);
CompareValues comp;
mkBool(v, comp(args[0], args[1]));
}
static RegisterPrimOp primop_lessThan({
.name = "__lessThan",
.args = {"e1", "e2"},
.doc = R"(
Return `true` if the number *e1* is less than the number *e2*, and
`false` otherwise. Evaluation aborts if either *e1* or *e2* does not
evaluate to a number.
)",
.fun = prim_lessThan,
});
/*************************************************************
* String manipulation
*************************************************************/
/* Convert the argument to a string. Paths are *not* copied to the
store, so `toString /foo/bar' yields `"/foo/bar"', not
`"/nix/store/whatever..."'. */
static void prim_toString(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
PathSet context;
string s = state.coerceToString(pos, *args[0], context, true, false);
mkString(v, s, context);
}
static RegisterPrimOp primop_toString({
.name = "toString",
.args = {"e"},
.doc = R"(
Convert the expression *e* to a string. *e* can be:
- A string (in which case the string is returned unmodified).
- A path (e.g., `toString /foo/bar` yields `"/foo/bar"`.
- A set containing `{ __toString = self: ...; }` or `{ outPath = ...; }`.
- An integer.
- A list, in which case the string representations of its elements
are joined with spaces.
- A Boolean (`false` yields `""`, `true` yields `"1"`).
- `null`, which yields the empty string.
)",
.fun = prim_toString,
});
2007-12-31 00:08:09 +00:00
/* `substring start len str' returns the substring of `str' starting
at character position `min(start, stringLength str)' inclusive and
ending at `min(start + len, stringLength str)'. `start' must be
non-negative. */
static void prim_substring(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
2014-04-04 16:58:15 +00:00
int start = state.forceInt(*args[0], pos);
int len = state.forceInt(*args[1], pos);
PathSet context;
string s = state.coerceToString(pos, *args[2], context);
if (start < 0)
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("negative start position in 'substring'"),
.errPos = pos
});
2014-05-26 10:34:15 +00:00
mkString(v, (unsigned int) start >= s.size() ? "" : string(s, start, len), context);
}
static RegisterPrimOp primop_substring({
.name = "__substring",
.args = {"start", "len", "s"},
.doc = R"(
Return the substring of *s* from character position *start*
(zero-based) up to but not including *start + len*. If *start* is
greater than the length of the string, an empty string is returned,
and if *start + len* lies beyond the end of the string, only the
substring up to the end of the string is returned. *start* must be
non-negative. For example,
```nix
builtins.substring 0 3 "nixos"
```
evaluates to `"nix"`.
)",
.fun = prim_substring,
});
static void prim_stringLength(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
PathSet context;
string s = state.coerceToString(pos, *args[0], context);
2010-03-30 18:05:54 +00:00
mkInt(v, s.size());
}
static RegisterPrimOp primop_stringLength({
.name = "__stringLength",
.args = {"e"},
.doc = R"(
Return the length of the string *e*. If *e* is not a string,
evaluation is aborted.
)",
.fun = prim_stringLength,
});
/* Return the cryptographic hash of a string in base-16. */
static void prim_hashString(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
2014-04-04 19:14:11 +00:00
string type = state.forceStringNoCtx(*args[0], pos);
std::optional<HashType> ht = parseHashType(type);
if (!ht)
throw Error({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("unknown hash type '%1%'", type),
.errPos = pos
});
PathSet context; // discarded
2014-11-25 09:23:36 +00:00
string s = state.forceString(*args[1], context, pos);
mkString(v, hashString(*ht, s).to_string(Base16, false), context);
}
static RegisterPrimOp primop_hashString({
.name = "__hashString",
.args = {"type", "s"},
.doc = R"(
Return a base-16 representation of the cryptographic hash of string
*s*. The hash algorithm specified by *type* must be one of `"md5"`,
`"sha1"`, `"sha256"` or `"sha512"`.
)",
.fun = prim_hashString,
});
struct RegexCache
{
std::unordered_map<std::string, std::regex> cache;
};
std::shared_ptr<RegexCache> makeRegexCache()
{
return std::make_shared<RegexCache>();
}
void prim_match(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
auto re = state.forceStringNoCtx(*args[0], pos);
try {
auto regex = state.regexCache->cache.find(re);
if (regex == state.regexCache->cache.end())
regex = state.regexCache->cache.emplace(re, std::regex(re, std::regex::extended)).first;
PathSet context;
const std::string str = state.forceString(*args[1], context, pos);
std::smatch match;
if (!std::regex_match(str, match, regex->second)) {
mkNull(v);
return;
}
// the first match is the whole string
const size_t len = match.size() - 1;
state.mkList(v, len);
for (size_t i = 0; i < len; ++i) {
if (!match[i+1].matched)
mkNull(*(v.listElems()[i] = state.allocValue()));
else
mkString(*(v.listElems()[i] = state.allocValue()), match[i + 1].str().c_str());
}
} catch (std::regex_error &e) {
if (e.code() == std::regex_constants::error_space) {
// limit is _GLIBCXX_REGEX_STATE_LIMIT for libstdc++
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("memory limit exceeded by regular expression '%s'", re),
.errPos = pos
});
} else {
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("invalid regular expression '%s'", re),
.errPos = pos
});
}
}
}
static RegisterPrimOp primop_match({
.name = "__match",
.args = {"regex", "str"},
.doc = R"s(
Returns a list if the [extended POSIX regular
expression](http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html#tag_09_04)
*regex* matches *str* precisely, otherwise returns `null`. Each item
in the list is a regex group.
```nix
builtins.match "ab" "abc"
```
Evaluates to `null`.
```nix
builtins.match "abc" "abc"
```
Evaluates to `[ ]`.
```nix
builtins.match "a(b)(c)" "abc"
```
Evaluates to `[ "b" "c" ]`.
```nix
builtins.match "[[:space:]]+([[:upper:]]+)[[:space:]]+" " FOO "
```
Evaluates to `[ "foo" ]`.
)s",
.fun = prim_match,
});
/* Split a string with a regular expression, and return a list of the
non-matching parts interleaved by the lists of the matching groups. */
static void prim_split(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
auto re = state.forceStringNoCtx(*args[0], pos);
try {
std::regex regex(re, std::regex::extended);
PathSet context;
const std::string str = state.forceString(*args[1], context, pos);
auto begin = std::sregex_iterator(str.begin(), str.end(), regex);
auto end = std::sregex_iterator();
// Any matches results are surrounded by non-matching results.
const size_t len = std::distance(begin, end);
state.mkList(v, 2 * len + 1);
size_t idx = 0;
Value * elem;
if (len == 0) {
v.listElems()[idx++] = args[1];
return;
}
for (std::sregex_iterator i = begin; i != end; ++i) {
assert(idx <= 2 * len + 1 - 3);
std::smatch match = *i;
// Add a string for non-matched characters.
elem = v.listElems()[idx++] = state.allocValue();
mkString(*elem, match.prefix().str().c_str());
// Add a list for matched substrings.
const size_t slen = match.size() - 1;
elem = v.listElems()[idx++] = state.allocValue();
// Start at 1, beacause the first match is the whole string.
state.mkList(*elem, slen);
for (size_t si = 0; si < slen; ++si) {
if (!match[si + 1].matched)
mkNull(*(elem->listElems()[si] = state.allocValue()));
else
mkString(*(elem->listElems()[si] = state.allocValue()), match[si + 1].str().c_str());
}
// Add a string for non-matched suffix characters.
if (idx == 2 * len) {
elem = v.listElems()[idx++] = state.allocValue();
mkString(*elem, match.suffix().str().c_str());
}
}
assert(idx == 2 * len + 1);
} catch (std::regex_error &e) {
if (e.code() == std::regex_constants::error_space) {
2020-05-13 21:56:39 +00:00
// limit is _GLIBCXX_REGEX_STATE_LIMIT for libstdc++
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("memory limit exceeded by regular expression '%s'", re),
.errPos = pos
});
} else {
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("invalid regular expression '%s'", re),
.errPos = pos
});
}
}
}
static RegisterPrimOp primop_split({
.name = "__split",
.args = {"regex", "str"},
.doc = R"s(
Returns a list composed of non matched strings interleaved with the
lists of the [extended POSIX regular
expression](http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html#tag_09_04)
*regex* matches of *str*. Each item in the lists of matched
sequences is a regex group.
```nix
builtins.split "(a)b" "abc"
```
Evaluates to `[ "" [ "a" ] "c" ]`.
```nix
builtins.split "([ac])" "abc"
```
Evaluates to `[ "" [ "a" ] "b" [ "c" ] "" ]`.
```nix
builtins.split "(a)|(c)" "abc"
```
Evaluates to `[ "" [ "a" null ] "b" [ null "c" ] "" ]`.
```nix
builtins.split "([[:upper:]]+)" " FOO "
```
Evaluates to `[ " " [ "FOO" ] " " ]`.
)s",
.fun = prim_split,
});
static void prim_concatStringsSep(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
PathSet context;
auto sep = state.forceString(*args[0], context, pos);
state.forceList(*args[1], pos);
string res;
res.reserve((args[1]->listSize() + 32) * sep.size());
bool first = true;
for (unsigned int n = 0; n < args[1]->listSize(); ++n) {
if (first) first = false; else res += sep;
res += state.coerceToString(pos, *args[1]->listElems()[n], context);
}
mkString(v, res, context);
}
static RegisterPrimOp primop_concatStringsSep({
.name = "__concatStringsSep",
.args = {"separator", "list"},
.doc = R"(
Concatenate a list of strings with a separator between each
element, e.g. `concatStringsSep "/" ["usr" "local" "bin"] ==
"usr/local/bin"`.
)",
.fun = prim_concatStringsSep,
});
static void prim_replaceStrings(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceList(*args[0], pos);
state.forceList(*args[1], pos);
if (args[0]->listSize() != args[1]->listSize())
throw EvalError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) { Example after: error: assertion 'false' failed at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| … while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${attrs.pname}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("'from' and 'to' arguments to 'replaceStrings' have different lengths"),
.errPos = pos
});
vector<string> from;
from.reserve(args[0]->listSize());
for (unsigned int n = 0; n < args[0]->listSize(); ++n)
from.push_back(state.forceString(*args[0]->listElems()[n], pos));
vector<std::pair<string, PathSet>> to;
to.reserve(args[1]->listSize());
for (unsigned int n = 0; n < args[1]->listSize(); ++n) {
PathSet ctx;
auto s = state.forceString(*args[1]->listElems()[n], ctx, pos);
to.push_back(std::make_pair(std::move(s), std::move(ctx)));
}
PathSet context;
auto s = state.forceString(*args[2], context, pos);
string res;
// Loops one past last character to handle the case where 'from' contains an empty string.
for (size_t p = 0; p <= s.size(); ) {
bool found = false;
auto i = from.begin();
auto j = to.begin();
for (; i != from.end(); ++i, ++j)
if (s.compare(p, i->size(), *i) == 0) {
found = true;
res += j->first;
if (i->empty()) {
if (p < s.size())
res += s[p];
p++;
} else {
p += i->size();
}
for (auto& path : j->second)
context.insert(path);
j->second.clear();
break;
}
if (!found) {
if (p < s.size())
res += s[p];
p++;
}
}
mkString(v, res, context);
}
static RegisterPrimOp primop_replaceStrings({
.name = "__replaceStrings",
.args = {"from", "to", "s"},
.doc = R"(
Given string *s*, replace every occurrence of the strings in *from*
with the corresponding string in *to*. For example,
```nix
builtins.replaceStrings ["oo" "a"] ["a" "i"] "foobar"
```
evaluates to `"fabir"`.
)",
.fun = prim_replaceStrings,
});
/*************************************************************
* Versions
*************************************************************/
static void prim_parseDrvName(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
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string name = state.forceStringNoCtx(*args[0], pos);
DrvName parsed(name);
state.mkAttrs(v, 2);
mkString(*state.allocAttr(v, state.sName), parsed.name);
mkString(*state.allocAttr(v, state.symbols.create("version")), parsed.version);
v.attrs->sort();
}
static RegisterPrimOp primop_parseDrvName({
.name = "__parseDrvName",
.args = {"s"},
.doc = R"(
Split the string *s* into a package name and version. The package
name is everything up to but not including the first dash followed
by a digit, and the version is everything following that dash. The
result is returned in a set `{ name, version }`. Thus,
`builtins.parseDrvName "nix-0.12pre12876"` returns `{ name =
"nix"; version = "0.12pre12876"; }`.
)",
.fun = prim_parseDrvName,
});
static void prim_compareVersions(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
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string version1 = state.forceStringNoCtx(*args[0], pos);
string version2 = state.forceStringNoCtx(*args[1], pos);
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mkInt(v, compareVersions(version1, version2));
}
static RegisterPrimOp primop_compareVersions({
.name = "__compareVersions",
.args = {"s1", "s2"},
.doc = R"(
Compare two strings representing versions and return `-1` if
version *s1* is older than version *s2*, `0` if they are the same,
and `1` if *s1* is newer than *s2*. The version comparison
algorithm is the same as the one used by [`nix-env
-u`](../command-ref/nix-env.md#operation---upgrade).
)",
.fun = prim_compareVersions,
});
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static void prim_splitVersion(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
string version = state.forceStringNoCtx(*args[0], pos);
auto iter = version.cbegin();
Strings components;
while (iter != version.cend()) {
auto component = nextComponent(iter, version.cend());
if (component.empty())
break;
components.emplace_back(std::move(component));
}
state.mkList(v, components.size());
unsigned int n = 0;
for (auto & component : components) {
auto listElem = v.listElems()[n++] = state.allocValue();
mkString(*listElem, std::move(component));
}
}
static RegisterPrimOp primop_splitVersion({
.name = "__splitVersion",
.args = {"s"},
.doc = R"(
Split a string representing a version into its components, by the
same version splitting logic underlying the version comparison in
[`nix-env -u`](../command-ref/nix-env.md#operation---upgrade).
)",
.fun = prim_splitVersion,
});
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/*************************************************************
* Primop registration
*************************************************************/
RegisterPrimOp::PrimOps * RegisterPrimOp::primOps;
RegisterPrimOp::RegisterPrimOp(std::string name, size_t arity, PrimOpFun fun,
std::optional<std::string> requiredFeature)
{
if (!primOps) primOps = new PrimOps;
primOps->push_back({
.name = name,
.args = {},
.arity = arity,
.requiredFeature = std::move(requiredFeature),
.fun = fun
});
}
RegisterPrimOp::RegisterPrimOp(Info && info)
{
if (!primOps) primOps = new PrimOps;
primOps->push_back(std::move(info));
}
void EvalState::createBaseEnv()
{
baseEnv.up = 0;
/* Add global constants such as `true' to the base environment. */
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Value v;
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/* `builtins' must be first! */
mkAttrs(v, 128);
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addConstant("builtins", v);
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mkBool(v, true);
addConstant("true", v);
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mkBool(v, false);
addConstant("false", v);
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mkNull(v);
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addConstant("null", v);
if (!evalSettings.pureEval) {
mkInt(v, time(0));
addConstant("__currentTime", v);
mkString(v, settings.thisSystem.get());
addConstant("__currentSystem", v);
}
mkString(v, nixVersion);
addConstant("__nixVersion", v);
mkString(v, store->storeDir);
addConstant("__storeDir", v);
/* Language version. This should be increased every time a new
language feature gets added. It's not necessary to increase it
when primops get added, because you can just use `builtins ?
primOp' to check. */
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mkInt(v, 5);
addConstant("__langVersion", v);
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// Miscellaneous
if (evalSettings.enableNativeCode) {
addPrimOp("__importNative", 2, prim_importNative);
addPrimOp("__exec", 1, prim_exec);
}
/* Add a value containing the current Nix expression search path. */
mkList(v, searchPath.size());
int n = 0;
for (auto & i : searchPath) {
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auto v2 = v.listElems()[n++] = allocValue();
mkAttrs(*v2, 2);
mkString(*allocAttr(*v2, symbols.create("path")), i.second);
mkString(*allocAttr(*v2, symbols.create("prefix")), i.first);
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v2->attrs->sort();
}
addConstant("__nixPath", v);
if (RegisterPrimOp::primOps)
for (auto & primOp : *RegisterPrimOp::primOps)
if (!primOp.requiredFeature || settings.isExperimentalFeatureEnabled(*primOp.requiredFeature))
addPrimOp({
.fun = primOp.fun,
.arity = std::max(primOp.args.size(), primOp.arity),
.name = symbols.create(primOp.name),
.args = std::move(primOp.args),
.doc = primOp.doc,
});
/* Add a wrapper around the derivation primop that computes the
`drvPath' and `outPath' attributes lazily. */
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sDerivationNix = symbols.create("//builtin/derivation.nix");
eval(parse(
#include "primops/derivation.nix.gen.hh"
, foFile, sDerivationNix, "/", staticBaseEnv), v);
addConstant("derivation", v);
/* Now that we've added all primops, sort the `builtins' set,
because attribute lookups expect it to be sorted. */
baseEnv.values[0]->attrs->sort();
}
}