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Merge pull request #5416 from bburdette/debug-exploratory-PR

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--debugger flag
This commit is contained in:
Eelco Dolstra 2022-05-26 08:12:19 +02:00 committed by GitHub
parent d8398d33c9 9068d32e12
commit 5f097fbcef
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GPG key ID: 4AEE18F83AFDEB23
17 changed files with 906 additions and 310 deletions
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13
doc/manual/src/release-notes/rl-next.md
View file

@ -25,5 +25,18 @@
Selecting derivation outputs using the attribute selection syntax
(e.g. `nixpkgs#glibc.dev`) no longer works.
* Running nix with the new `--debugger` flag will cause it to start a repl session if
there is an exception thrown during eval, or if `builtins.break` is called. From
there one can inspect symbol values and evaluate nix expressions. In debug mode
the following new repl commands are available:
```
:env Show env stack
:bt Show trace stack
:st Show current trace
:st <idx> Change to another trace in the stack
:c Go until end of program, exception, or builtins.break().
:s Go one step
```
* `builtins.fetchTree` (and flake inputs) can now be used to fetch plain files
over the `http(s)` and `file` protocols in addition to directory tarballs.

12
src/libcmd/command.cc
View file

@ -86,6 +86,11 @@ ref<Store> CopyCommand::getDstStore()
EvalCommand::EvalCommand()
{
addFlag({
.longName = "debugger",
.description = "start an interactive environment if evaluation fails",
.handler = {&startReplOnEvalErrors, true},
});
}
EvalCommand::~EvalCommand()
@ -103,7 +108,7 @@ ref<Store> EvalCommand::getEvalStore()
ref<EvalState> EvalCommand::getEvalState()
{
if (!evalState)
if (!evalState) {
evalState =
#if HAVE_BOEHMGC
std::allocate_shared<EvalState>(traceable_allocator<EvalState>(),
@ -113,6 +118,11 @@ ref<EvalState> EvalCommand::getEvalState()
searchPath, getEvalStore(), getStore())
#endif
;
if (startReplOnEvalErrors) {
evalState->debugRepl = &runRepl;
};
}
return ref<EvalState>(evalState);
}

6
src/libcmd/command.hh
View file

@ -57,6 +57,8 @@ struct CopyCommand : virtual StoreCommand
struct EvalCommand : virtual StoreCommand, MixEvalArgs
{
bool startReplOnEvalErrors = false;
EvalCommand();
~EvalCommand();
@ -270,4 +272,8 @@ void printClosureDiff(
const StorePath & afterPath,
std::string_view indent);
void runRepl(
ref<EvalState> evalState,
const ValMap & extraEnv);
}

4
src/libcmd/local.mk
View file

@ -6,9 +6,9 @@ libcmd_DIR := $(d)
libcmd_SOURCES := $(wildcard $(d)/*.cc)
libcmd_CXXFLAGS += -I src/libutil -I src/libstore -I src/libexpr -I src/libmain -I src/libfetchers
libcmd_CXXFLAGS += -I src/libutil -I src/libstore -I src/libexpr -I src/libmain -I src/libfetchers -I src/nix
libcmd_LDFLAGS += $(LOWDOWN_LIBS) -pthread
libcmd_LDFLAGS = $(EDITLINE_LIBS) -llowdown -pthread
libcmd_LIBS = libstore libutil libexpr libmain libfetchers

192
src/nix/repl.cc → src/libcmd/repl.cc
View file

@ -48,20 +48,22 @@ struct NixRepl
#endif
{
std::string curDir;
std::unique_ptr<EvalState> state;
ref<EvalState> state;
Bindings * autoArgs;
size_t debugTraceIndex;
Strings loadedFiles;
const static int envSize = 32768;
StaticEnv staticEnv;
std::shared_ptr<StaticEnv> staticEnv;
Env * env;
int displ;
StringSet varNames;
const Path historyFile;
NixRepl(const Strings & searchPath, nix::ref<Store> store);
NixRepl(ref<EvalState> state);
~NixRepl();
void mainLoop(const std::vector<std::string> & files);
StringSet completePrefix(const std::string & prefix);
@ -71,11 +73,13 @@ struct NixRepl
void loadFile(const Path & path);
void loadFlake(const std::string & flakeRef);
void initEnv();
void loadFiles();
void reloadFiles();
void addAttrsToScope(Value & attrs);
void addVarToScope(const Symbol name, Value & v);
Expr * parseString(std::string s);
void evalString(std::string s, Value & v);
void loadDebugTraceEnv(DebugTrace & dt);
typedef std::set<Value *> ValuesSeen;
std::ostream & printValue(std::ostream & str, Value & v, unsigned int maxDepth);
@ -92,9 +96,10 @@ std::string removeWhitespace(std::string s)
}
NixRepl::NixRepl(const Strings & searchPath, nix::ref<Store> store)
: state(std::make_unique<EvalState>(searchPath, store))
, staticEnv(false, &state->staticBaseEnv)
NixRepl::NixRepl(ref<EvalState> state)
: state(state)
, debugTraceIndex(0)
, staticEnv(new StaticEnv(false, state->staticBaseEnv.get()))
, historyFile(getDataDir() + "/nix/repl-history")
{
curDir = absPath(".");
@ -198,15 +203,42 @@ namespace {
}
}
static std::ostream & showDebugTrace(std::ostream & out, const PosTable & positions, const DebugTrace & dt)
{
if (dt.isError)
out << ANSI_RED "error: " << ANSI_NORMAL;
out << dt.hint.str() << "\n";
// prefer direct pos, but if noPos then try the expr.
auto pos = *dt.pos
? *dt.pos
: positions[dt.expr.getPos() ? dt.expr.getPos() : noPos];
if (pos) {
printAtPos(pos, out);
auto loc = getCodeLines(pos);
if (loc.has_value()) {
out << "\n";
printCodeLines(out, "", pos, *loc);
out << "\n";
}
}
return out;
}
void NixRepl::mainLoop(const std::vector<std::string> & files)
{
std::string error = ANSI_RED "error:" ANSI_NORMAL " ";
notice("Welcome to Nix " + nixVersion + ". Type :? for help.\n");
if (!files.empty()) {
for (auto & i : files)
loadedFiles.push_back(i);
}
reloadFiles();
loadFiles();
if (!loadedFiles.empty()) notice("");
// Allow nix-repl specific settings in .inputrc
@ -227,9 +259,12 @@ void NixRepl::mainLoop(const std::vector<std::string> & files)
while (true) {
// When continuing input from previous lines, don't print a prompt, just align to the same
// number of chars as the prompt.
if (!getLine(input, input.empty() ? "nix-repl> " : " "))
if (!getLine(input, input.empty() ? "nix-repl> " : " ")) {
// ctrl-D should exit the debugger.
state->debugStop = false;
state->debugQuit = true;
break;
}
try {
if (!removeWhitespace(input).empty() && !processLine(input)) return;
} catch (ParseError & e) {
@ -240,6 +275,14 @@ void NixRepl::mainLoop(const std::vector<std::string> & files)
} else {
printMsg(lvlError, e.msg());
}
} catch (EvalError & e) {
// in debugger mode, an EvalError should trigger another repl session.
// when that session returns the exception will land here. No need to show it again;
// show the error for this repl session instead.
if (state->debugRepl && !state->debugTraces.empty())
showDebugTrace(std::cout, state->positions, state->debugTraces.front());
else
printMsg(lvlError, e.msg());
} catch (Error & e) {
printMsg(lvlError, e.msg());
} catch (Interrupted & e) {
@ -394,6 +437,19 @@ StorePath NixRepl::getDerivationPath(Value & v) {
return *drvPath;
}
void NixRepl::loadDebugTraceEnv(DebugTrace & dt)
{
initEnv();
auto se = state->getStaticEnv(dt.expr);
if (se) {
auto vm = mapStaticEnvBindings(state->symbols, *se.get(), dt.env);
// add staticenv vars.
for (auto & [name, value] : *(vm.get()))
addVarToScope(state->symbols.create(name), *value);
}
}
bool NixRepl::processLine(std::string line)
{
@ -429,12 +485,72 @@ bool NixRepl::processLine(std::string line)
<< " :p <expr> Evaluate and print expression recursively\n"
<< " :q Exit nix-repl\n"
<< " :r Reload all files\n"
<< " :s <expr> Build dependencies of derivation, then start nix-shell\n"
<< " :sh <expr> Build dependencies of derivation, then start nix-shell\n"
<< " :t <expr> Describe result of evaluation\n"
<< " :u <expr> Build derivation, then start nix-shell\n"
<< " :doc <expr> Show documentation of a builtin function\n"
<< " :log <expr> Show logs for a derivation\n"
<< " :st [bool] Enable, disable or toggle showing traces for errors\n";
<< " :te [bool] Enable, disable or toggle showing traces for errors\n"
;
if (state->debugRepl) {
std::cout
<< "\n"
<< " Debug mode commands\n"
<< " :env Show env stack\n"
<< " :bt Show trace stack\n"
<< " :st Show current trace\n"
<< " :st <idx> Change to another trace in the stack\n"
<< " :c Go until end of program, exception, or builtins.break\n"
<< " :s Go one step\n"
;
}
}
else if (state->debugRepl && (command == ":bt" || command == ":backtrace")) {
for (const auto & [idx, i] : enumerate(state->debugTraces)) {
std::cout << "\n" << ANSI_BLUE << idx << ANSI_NORMAL << ": ";
showDebugTrace(std::cout, state->positions, i);
}
}
else if (state->debugRepl && (command == ":env")) {
for (const auto & [idx, i] : enumerate(state->debugTraces)) {
if (idx == debugTraceIndex) {
printEnvBindings(*state, i.expr, i.env);
break;
}
}
}
else if (state->debugRepl && (command == ":st")) {
try {
// change the DebugTrace index.
debugTraceIndex = stoi(arg);
} catch (...) { }
for (const auto & [idx, i] : enumerate(state->debugTraces)) {
if (idx == debugTraceIndex) {
std::cout << "\n" << ANSI_BLUE << idx << ANSI_NORMAL << ": ";
showDebugTrace(std::cout, state->positions, i);
std::cout << std::endl;
printEnvBindings(*state, i.expr, i.env);
loadDebugTraceEnv(i);
break;
}
}
}
else if (state->debugRepl && (command == ":s" || command == ":step")) {
// set flag to stop at next DebugTrace; exit repl.
state->debugStop = true;
return false;
}
else if (state->debugRepl && (command == ":c" || command == ":continue")) {
// set flag to run to next breakpoint or end of program; exit repl.
state->debugStop = false;
return false;
}
else if (command == ":a" || command == ":add") {
@ -506,7 +622,7 @@ bool NixRepl::processLine(std::string line)
runNix("nix-shell", {state->store->printStorePath(drvPath)});
}
else if (command == ":b" || command == ":bl" || command == ":i" || command == ":s" || command == ":log") {
else if (command == ":b" || command == ":bl" || command == ":i" || command == ":sh" || command == ":log") {
Value v;
evalString(arg, v);
StorePath drvPath = getDerivationPath(v);
@ -567,8 +683,11 @@ bool NixRepl::processLine(std::string line)
printValue(std::cout, v, 1000000000) << std::endl;
}
else if (command == ":q" || command == ":quit")
else if (command == ":q" || command == ":quit") {
state->debugStop = false;
state->debugQuit = true;
return false;
}
else if (command == ":doc") {
Value v;
@ -593,7 +712,7 @@ bool NixRepl::processLine(std::string line)
throw Error("value does not have documentation");
}
else if (command == ":st" || command == ":show-trace") {
else if (command == ":te" || command == ":trace-enable") {
if (arg == "false" || (arg == "" && loggerSettings.showTrace)) {
std::cout << "not showing error traces\n";
loggerSettings.showTrace = false;
@ -669,10 +788,10 @@ void NixRepl::initEnv()
env = &state->allocEnv(envSize);
env->up = &state->baseEnv;
displ = 0;
staticEnv.vars.clear();
staticEnv->vars.clear();
varNames.clear();
for (auto & i : state->staticBaseEnv.vars)
for (auto & i : state->staticBaseEnv->vars)
varNames.emplace(state->symbols[i.first]);
}
@ -681,6 +800,12 @@ void NixRepl::reloadFiles()
{
initEnv();
loadFiles();
}
void NixRepl::loadFiles()
{
Strings old = loadedFiles;
loadedFiles.clear();
@ -701,12 +826,12 @@ void NixRepl::addAttrsToScope(Value & attrs)
throw Error("environment full; cannot add more variables");
for (auto & i : *attrs.attrs) {
staticEnv.vars.emplace_back(i.name, displ);
staticEnv->vars.emplace_back(i.name, displ);
env->values[displ++] = i.value;
varNames.emplace(state->symbols[i.name]);
}
staticEnv.sort();
staticEnv.deduplicate();
staticEnv->sort();
staticEnv->deduplicate();
notice("Added %1% variables.", attrs.attrs->size());
}
@ -715,10 +840,10 @@ void NixRepl::addVarToScope(const Symbol name, Value & v)
{
if (displ >= envSize)
throw Error("environment full; cannot add more variables");
if (auto oldVar = staticEnv.find(name); oldVar != staticEnv.vars.end())
staticEnv.vars.erase(oldVar);
staticEnv.vars.emplace_back(name, displ);
staticEnv.sort();
if (auto oldVar = staticEnv->find(name); oldVar != staticEnv->vars.end())
staticEnv->vars.erase(oldVar);
staticEnv->vars.emplace_back(name, displ);
staticEnv->sort();
env->values[displ++] = &v;
varNames.emplace(state->symbols[name]);
}
@ -886,6 +1011,21 @@ std::ostream & NixRepl::printValue(std::ostream & str, Value & v, unsigned int m
return str;
}
void runRepl(
ref<EvalState>evalState,
const ValMap & extraEnv)
{
auto repl = std::make_unique<NixRepl>(evalState);
repl->initEnv();
// add 'extra' vars.
for (auto & [name, value] : extraEnv)
repl->addVarToScope(repl->state->symbols.create(name), *value);
repl->mainLoop({});
}
struct CmdRepl : StoreCommand, MixEvalArgs
{
std::vector<std::string> files;
@ -914,8 +1054,12 @@ struct CmdRepl : StoreCommand, MixEvalArgs
void run(ref<Store> store) override
{
evalSettings.pureEval = false;
auto repl = std::make_unique<NixRepl>(searchPath, openStore());
auto evalState = make_ref<EvalState>(searchPath, store);
auto repl = std::make_unique<NixRepl>(evalState);
repl->autoArgs = getAutoArgs(*repl->state);
repl->initEnv();
repl->mainLoop(files);
}
};

16
src/libexpr/eval-cache.cc
View file

@ -576,14 +576,14 @@ std::string AttrCursor::getString()
debug("using cached string attribute '%s'", getAttrPathStr());
return s->first;
} else
throw TypeError("'%s' is not a string", getAttrPathStr());
root->state.debugThrowLastTrace(TypeError("'%s' is not a string", getAttrPathStr()));
}
}
auto & v = forceValue();
if (v.type() != nString && v.type() != nPath)
throw TypeError("'%s' is not a string but %s", getAttrPathStr(), showType(v.type()));
root->state.debugThrowLastTrace(TypeError("'%s' is not a string but %s", getAttrPathStr(), showType(v.type())));
return v.type() == nString ? v.string.s : v.path;
}
@ -607,7 +607,7 @@ string_t AttrCursor::getStringWithContext()
return *s;
}
} else
throw TypeError("'%s' is not a string", getAttrPathStr());
root->state.debugThrowLastTrace(TypeError("'%s' is not a string", getAttrPathStr()));
}
}
@ -618,7 +618,7 @@ string_t AttrCursor::getStringWithContext()
else if (v.type() == nPath)
return {v.path, {}};
else
throw TypeError("'%s' is not a string but %s", getAttrPathStr(), showType(v.type()));
root->state.debugThrowLastTrace(TypeError("'%s' is not a string but %s", getAttrPathStr(), showType(v.type())));
}
bool AttrCursor::getBool()
@ -631,14 +631,14 @@ bool AttrCursor::getBool()
debug("using cached Boolean attribute '%s'", getAttrPathStr());
return *b;
} else
throw TypeError("'%s' is not a Boolean", getAttrPathStr());
root->state.debugThrowLastTrace(TypeError("'%s' is not a Boolean", getAttrPathStr()));
}
}
auto & v = forceValue();
if (v.type() != nBool)
throw TypeError("'%s' is not a Boolean", getAttrPathStr());
root->state.debugThrowLastTrace(TypeError("'%s' is not a Boolean", getAttrPathStr()));
return v.boolean;
}
@ -708,14 +708,14 @@ std::vector<Symbol> AttrCursor::getAttrs()
debug("using cached attrset attribute '%s'", getAttrPathStr());
return *attrs;
} else
throw TypeError("'%s' is not an attribute set", getAttrPathStr());
root->state.debugThrowLastTrace(TypeError("'%s' is not an attribute set", getAttrPathStr()));
}
}
auto & v = forceValue();
if (v.type() != nAttrs)
throw TypeError("'%s' is not an attribute set", getAttrPathStr());
root->state.debugThrowLastTrace(TypeError("'%s' is not an attribute set", getAttrPathStr()));
std::vector<Symbol> attrs;
for (auto & attr : *getValue().attrs)

1
src/libexpr/eval-inline.hh
View file

@ -4,7 +4,6 @@
namespace nix {
/* Note: Various places expect the allocated memory to be zeroed. */
[[gnu::always_inline]]
inline void * allocBytes(size_t n)

363
src/libexpr/eval.cc
View file

@ -18,6 +18,7 @@
#include <sys/resource.h>
#include <iostream>
#include <fstream>
#include <functional>
#include <sys/resource.h>
@ -36,7 +37,6 @@
namespace nix {
static char * allocString(size_t size)
{
char * t;
@ -463,6 +463,9 @@ EvalState::EvalState(
, emptyBindings(0)
, store(store)
, buildStore(buildStore ? buildStore : store)
, debugRepl(0)
, debugStop(false)
, debugQuit(false)
, regexCache(makeRegexCache())
#if HAVE_BOEHMGC
, valueAllocCache(std::allocate_shared<void *>(traceable_allocator<void *>(), nullptr))
@ -472,7 +475,7 @@ EvalState::EvalState(
, env1AllocCache(std::make_shared<void *>(nullptr))
#endif
, baseEnv(allocEnv(128))
, staticBaseEnv(false, 0)
, staticBaseEnv{std::make_shared<StaticEnv>(false, nullptr)}
{
countCalls = getEnv("NIX_COUNT_CALLS").value_or("0") != "0";
@ -638,7 +641,7 @@ Value * EvalState::addConstant(const std::string & name, Value & v)
void EvalState::addConstant(const std::string & name, Value * v)
{
staticBaseEnv.vars.emplace_back(symbols.create(name), baseEnvDispl);
staticBaseEnv->vars.emplace_back(symbols.create(name), baseEnvDispl);
baseEnv.values[baseEnvDispl++] = v;
auto name2 = name.substr(0, 2) == "__" ? name.substr(2) : name;
baseEnv.values[0]->attrs->push_back(Attr(symbols.create(name2), v));
@ -663,7 +666,7 @@ Value * EvalState::addPrimOp(const std::string & name,
Value * v = allocValue();
v->mkPrimOp(new PrimOp { .fun = primOp, .arity = arity, .name = name2 });
staticBaseEnv.vars.emplace_back(symbols.create(name), baseEnvDispl);
staticBaseEnv->vars.emplace_back(symbols.create(name), baseEnvDispl);
baseEnv.values[baseEnvDispl++] = v;
baseEnv.values[0]->attrs->push_back(Attr(sym, v));
return v;
@ -689,7 +692,7 @@ Value * EvalState::addPrimOp(PrimOp && primOp)
Value * v = allocValue();
v->mkPrimOp(new PrimOp(primOp));
staticBaseEnv.vars.emplace_back(envName, baseEnvDispl);
staticBaseEnv->vars.emplace_back(envName, baseEnvDispl);
baseEnv.values[baseEnvDispl++] = v;
baseEnv.values[0]->attrs->push_back(Attr(symbols.create(primOp.name), v));
return v;
@ -719,128 +722,284 @@ std::optional<EvalState::Doc> EvalState::getDoc(Value & v)
}
// just for the current level of StaticEnv, not the whole chain.
void printStaticEnvBindings(const SymbolTable & st, const StaticEnv & se)
{
std::cout << ANSI_MAGENTA;
for (auto & i : se.vars)
std::cout << st[i.first] << " ";
std::cout << ANSI_NORMAL;
std::cout << std::endl;
}
// just for the current level of Env, not the whole chain.
void printWithBindings(const SymbolTable & st, const Env & env)
{
if (env.type == Env::HasWithAttrs) {
std::cout << "with: ";
std::cout << ANSI_MAGENTA;
Bindings::iterator j = env.values[0]->attrs->begin();
while (j != env.values[0]->attrs->end()) {
std::cout << st[j->name] << " ";
++j;
}
std::cout << ANSI_NORMAL;
std::cout << std::endl;
}
}
void printEnvBindings(const SymbolTable & st, const StaticEnv & se, const Env & env, int lvl)
{
std::cout << "Env level " << lvl << std::endl;
if (se.up && env.up) {
std::cout << "static: ";
printStaticEnvBindings(st, se);
printWithBindings(st, env);
std::cout << std::endl;
printEnvBindings(st, *se.up, *env.up, ++lvl);
} else {
std::cout << ANSI_MAGENTA;
// for the top level, don't print the double underscore ones;
// they are in builtins.
for (auto & i : se.vars)
if (!hasPrefix(st[i.first], "__"))
std::cout << st[i.first] << " ";
std::cout << ANSI_NORMAL;
std::cout << std::endl;
printWithBindings(st, env); // probably nothing there for the top level.
std::cout << std::endl;
}
}
void printEnvBindings(const EvalState &es, const Expr & expr, const Env & env)
{
// just print the names for now
auto se = es.getStaticEnv(expr);
if (se)
printEnvBindings(es.symbols, *se, env, 0);
}
void mapStaticEnvBindings(const SymbolTable & st, const StaticEnv & se, const Env & env, ValMap & vm)
{
// add bindings for the next level up first, so that the bindings for this level
// override the higher levels.
// The top level bindings (builtins) are skipped since they are added for us by initEnv()
if (env.up && se.up) {
mapStaticEnvBindings(st, *se.up, *env.up, vm);
if (env.type == Env::HasWithAttrs) {
// add 'with' bindings.
Bindings::iterator j = env.values[0]->attrs->begin();
while (j != env.values[0]->attrs->end()) {
vm[st[j->name]] = j->value;
++j;
}
} else {
// iterate through staticenv bindings and add them.
for (auto & i : se.vars)
vm[st[i.first]] = env.values[i.second];
}
}
}
std::unique_ptr<ValMap> mapStaticEnvBindings(const SymbolTable & st, const StaticEnv & se, const Env & env)
{
auto vm = std::make_unique<ValMap>();
mapStaticEnvBindings(st, se, env, *vm);
return vm;
}
void EvalState::runDebugRepl(const Error * error, const Env & env, const Expr & expr)
{
// double check we've got the debugRepl function pointer.
if (!debugRepl)
return;
auto dts =
error && expr.getPos()
? std::make_unique<DebugTraceStacker>(
*this,
DebugTrace {
.pos = error->info().errPos ? *error->info().errPos : positions[expr.getPos()],
.expr = expr,
.env = env,
.hint = error->info().msg,
.isError = true
})
: nullptr;
if (error)
printError("%s\n\n" ANSI_BOLD "Starting REPL to allow you to inspect the current state of the evaluator.\n" ANSI_NORMAL, error->what());
auto se = getStaticEnv(expr);
if (se) {
auto vm = mapStaticEnvBindings(symbols, *se.get(), env);
(debugRepl)(ref<EvalState>(shared_from_this()), *vm);
}
}
/* Every "format" object (even temporary) takes up a few hundred bytes
of stack space, which is a real killer in the recursive
evaluator. So here are some helper functions for throwing
exceptions. */
void EvalState::throwEvalError(const PosIdx pos, const char * s) const
void EvalState::throwEvalError(const PosIdx pos, const char * s, Env & env, Expr & expr)
{
throw EvalError({
debugThrow(EvalError({
.msg = hintfmt(s),
.errPos = positions[pos]
});
}), env, expr);
}
void EvalState::throwTypeError(const PosIdx pos, const char * s, const Value & v) const
void EvalState::throwEvalError(const PosIdx pos, const char * s)
{
throw TypeError({
.msg = hintfmt(s, showType(v)),
debugThrowLastTrace(EvalError({
.msg = hintfmt(s),
.errPos = positions[pos]
});
}));
}
void EvalState::throwEvalError(const char * s, const std::string & s2) const
void EvalState::throwEvalError(const char * s, const std::string & s2)
{
throw EvalError(s, s2);
debugThrowLastTrace(EvalError(s, s2));
}
void EvalState::throwEvalError(const PosIdx pos, const Suggestions & suggestions, const char * s,
const std::string & s2) const
const std::string & s2, Env & env, Expr & expr)
{
throw EvalError(ErrorInfo {
debugThrow(EvalError(ErrorInfo{
.msg = hintfmt(s, s2),
.errPos = positions[pos],
.suggestions = suggestions,
});
}), env, expr);
}
void EvalState::throwEvalError(const PosIdx pos, const char * s, const std::string & s2) const
void EvalState::throwEvalError(const PosIdx pos, const char * s, const std::string & s2)
{
throw EvalError(ErrorInfo {
debugThrowLastTrace(EvalError({
.msg = hintfmt(s, s2),
.errPos = positions[pos]
});
}));
}
void EvalState::throwEvalError(const char * s, const std::string & s2, const std::string & s3) const
void EvalState::throwEvalError(const PosIdx pos, const char * s, const std::string & s2, Env & env, Expr & expr)
{
throw EvalError(s, s2, s3);
debugThrow(EvalError({
.msg = hintfmt(s, s2),
.errPos = positions[pos]
}), env, expr);
}
void EvalState::throwEvalError(const char * s, const std::string & s2,
const std::string & s3)
{
debugThrowLastTrace(EvalError({
.msg = hintfmt(s, s2),
.errPos = positions[noPos]
}));
}
void EvalState::throwEvalError(const PosIdx pos, const char * s, const std::string & s2,
const std::string & s3) const
const std::string & s3)
{
throw EvalError({
.msg = hintfmt(s, s2, s3),
debugThrowLastTrace(EvalError({
.msg = hintfmt(s, s2),
.errPos = positions[pos]
});
}));
}
void EvalState::throwEvalError(const PosIdx p1, const char * s, const Symbol sym, const PosIdx p2) const
void EvalState::throwEvalError(const PosIdx pos, const char * s, const std::string & s2,
const std::string & s3, Env & env, Expr & expr)
{
debugThrow(EvalError({
.msg = hintfmt(s, s2),
.errPos = positions[pos]
}), env, expr);
}
void EvalState::throwEvalError(const PosIdx p1, const char * s, const Symbol sym, const PosIdx p2, Env & env, Expr & expr)
{
// p1 is where the error occurred; p2 is a position mentioned in the message.
throw EvalError({
debugThrow(EvalError({
.msg = hintfmt(s, symbols[sym], positions[p2]),
.errPos = positions[p1]
});
}), env, expr);
}
void EvalState::throwTypeError(const PosIdx pos, const char * s) const
void EvalState::throwTypeError(const PosIdx pos, const char * s, const Value & v)
{
throw TypeError({
debugThrowLastTrace(TypeError({
.msg = hintfmt(s, showType(v)),
.errPos = positions[pos]
}));
}
void EvalState::throwTypeError(const PosIdx pos, const char * s, const Value & v, Env & env, Expr & expr)
{
debugThrow(TypeError({
.msg = hintfmt(s, showType(v)),
.errPos = positions[pos]
}), env, expr);
}
void EvalState::throwTypeError(const PosIdx pos, const char * s)
{
debugThrowLastTrace(TypeError({
.msg = hintfmt(s),
.errPos = positions[pos]
});
}));
}
void EvalState::throwTypeError(const PosIdx pos, const char * s, const ExprLambda & fun,
const Symbol s2) const
const Symbol s2, Env & env, Expr &expr)
{
throw TypeError({
debugThrow(TypeError({
.msg = hintfmt(s, fun.showNamePos(*this), symbols[s2]),
.errPos = positions[pos]
});
}), env, expr);
}
void EvalState::throwTypeError(const PosIdx pos, const Suggestions & suggestions, const char * s,
const ExprLambda & fun, const Symbol s2) const
const ExprLambda & fun, const Symbol s2, Env & env, Expr &expr)
{
throw TypeError(ErrorInfo {
debugThrow(TypeError(ErrorInfo {
.msg = hintfmt(s, fun.showNamePos(*this), symbols[s2]),
.errPos = positions[pos],
.suggestions = suggestions,
});
}), env, expr);
}
void EvalState::throwTypeError(const char * s, const Value & v) const
void EvalState::throwTypeError(const char * s, const Value & v, Env & env, Expr &expr)
{
throw TypeError(s, showType(v));
debugThrow(TypeError({
.msg = hintfmt(s, showType(v)),
.errPos = positions[expr.getPos()],
}), env, expr);
}
void EvalState::throwAssertionError(const PosIdx pos, const char * s, const std::string & s1) const
void EvalState::throwAssertionError(const PosIdx pos, const char * s, const std::string & s1, Env & env, Expr &expr)
{
throw AssertionError({
debugThrow(AssertionError({
.msg = hintfmt(s, s1),
.errPos = positions[pos]
});
}), env, expr);
}
void EvalState::throwUndefinedVarError(const PosIdx pos, const char * s, const std::string & s1) const
void EvalState::throwUndefinedVarError(const PosIdx pos, const char * s, const std::string & s1, Env & env, Expr &expr)
{
throw UndefinedVarError({
debugThrow(UndefinedVarError({
.msg = hintfmt(s, s1),
.errPos = positions[pos]
});
}), env, expr);
}
void EvalState::throwMissingArgumentError(const PosIdx pos, const char * s, const std::string & s1) const
void EvalState::throwMissingArgumentError(const PosIdx pos, const char * s, const std::string & s1, Env & env, Expr &expr)
{
throw MissingArgumentError({
debugThrow(MissingArgumentError({
.msg = hintfmt(s, s1),
.errPos = positions[pos]
});
}), env, expr);
}
void EvalState::addErrorTrace(Error & e, const char * s, const std::string & s2) const
@ -853,6 +1012,32 @@ void EvalState::addErrorTrace(Error & e, const PosIdx pos, const char * s, const
e.addTrace(positions[pos], s, s2);
}
static std::unique_ptr<DebugTraceStacker> makeDebugTraceStacker(
EvalState & state,
Expr & expr,
Env & env,
std::optional<ErrPos> pos,
const char * s,
const std::string & s2)
{
return std::make_unique<DebugTraceStacker>(state,
DebugTrace {
.pos = pos,
.expr = expr,
.env = env,
.hint = hintfmt(s, s2),
.isError = false
});
}
DebugTraceStacker::DebugTraceStacker(EvalState & evalState, DebugTrace t)
: evalState(evalState)
, trace(std::move(t))
{
evalState.debugTraces.push_front(trace);
if (evalState.debugStop && evalState.debugRepl)
evalState.runDebugRepl(nullptr, trace.env, trace.expr);
}
void Value::mkString(std::string_view s)
{
@ -911,12 +1096,11 @@ inline Value * EvalState::lookupVar(Env * env, const ExprVar & var, bool noEval)
return j->value;
}
if (!env->prevWith)
throwUndefinedVarError(var.pos, "undefined variable '%1%'", symbols[var.name]);
throwUndefinedVarError(var.pos, "undefined variable '%1%'", symbols[var.name], *env, const_cast<ExprVar&>(var));
for (size_t l = env->prevWith; l; --l, env = env->up) ;
}
}
void EvalState::mkList(Value & v, size_t size)
{
v.mkList(size);
@ -1049,6 +1233,15 @@ void EvalState::cacheFile(
fileParseCache[resolvedPath] = e;
try {
auto dts = debugRepl
? makeDebugTraceStacker(
*this,
*e,
this->baseEnv,
e->getPos() ? std::optional(ErrPos(positions[e->getPos()])) : std::nullopt,
"while evaluating the file '%1%':", resolvedPath)
: nullptr;
// Enforce that 'flake.nix' is a direct attrset, not a
// computation.
if (mustBeTrivial &&
@ -1076,7 +1269,7 @@ inline bool EvalState::evalBool(Env & env, Expr * e)
Value v;
e->eval(*this, env, v);
if (v.type() != nBool)
throwTypeError("value is %1% while a Boolean was expected", v);
throwTypeError(noPos, "value is %1% while a Boolean was expected", v, env, *e);
return v.boolean;
}
@ -1086,7 +1279,7 @@ inline bool EvalState::evalBool(Env & env, Expr * e, const PosIdx pos)
Value v;
e->eval(*this, env, v);
if (v.type() != nBool)
throwTypeError(pos, "value is %1% while a Boolean was expected", v);
throwTypeError(pos, "value is %1% while a Boolean was expected", v, env, *e);
return v.boolean;
}
@ -1095,7 +1288,7 @@ inline void EvalState::evalAttrs(Env & env, Expr * e, Value & v)
{
e->eval(*this, env, v);
if (v.type() != nAttrs)
throwTypeError("value is %1% while a set was expected", v);
throwTypeError(noPos, "value is %1% while a set was expected", v, env, *e);
}
@ -1200,7 +1393,7 @@ void ExprAttrs::eval(EvalState & state, Env & env, Value & v)
auto nameSym = state.symbols.create(nameVal.string.s);
Bindings::iterator j = v.attrs->find(nameSym);
if (j != v.attrs->end())
state.throwEvalError(i.pos, "dynamic attribute '%1%' already defined at %2%", nameSym, j->pos);
state.throwEvalError(i.pos, "dynamic attribute '%1%' already defined at %2%", nameSym, j->pos, env, *this);
i.valueExpr->setName(nameSym);
/* Keep sorted order so find can catch duplicates */
@ -1274,6 +1467,15 @@ void ExprSelect::eval(EvalState & state, Env & env, Value & v)
e->eval(state, env, vTmp);
try {
auto dts = state.debugRepl
? makeDebugTraceStacker(
state,
*this,
env,
state.positions[pos2],
"while evaluating the attribute '%1%'",
showAttrPath(state, env, attrPath))
: nullptr;
for (auto & i : attrPath) {
state.nrLookups++;
@ -1296,7 +1498,7 @@ void ExprSelect::eval(EvalState & state, Env & env, Value & v)
state.throwEvalError(
pos,
Suggestions::bestMatches(allAttrNames, state.symbols[name]),
"attribute '%1%' missing", state.symbols[name]);
"attribute '%1%' missing", state.symbols[name], env, *this);
}
}
vAttrs = j->value;
@ -1387,7 +1589,6 @@ void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value &
if (!lambda.hasFormals())
env2.values[displ++] = args[0];
else {
forceAttrs(*args[0], pos);
@ -1402,7 +1603,7 @@ void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value &
auto j = args[0]->attrs->get(i.name);
if (!j) {
if (!i.def) throwTypeError(pos, "%1% called without required argument '%2%'",
lambda, i.name);
lambda, i.name, *fun.lambda.env, lambda);
env2.values[displ++] = i.def->maybeThunk(*this, env2);
} else {
attrsUsed++;
@ -1424,8 +1625,7 @@ void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value &
pos,
Suggestions::bestMatches(formalNames, symbols[i.name]),
"%1% called with unexpected argument '%2%'",
lambda,
i.name);
lambda, i.name, *fun.lambda.env, lambda);
}
abort(); // can't happen
}
@ -1436,6 +1636,15 @@ void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value &
/* Evaluate the body. */
try {
auto dts = debugRepl
? makeDebugTraceStacker(
*this, *lambda.body, env2, positions[lambda.pos],
"while evaluating %s",
lambda.name
? concatStrings("'", symbols[lambda.name], "'")
: "anonymous lambda")
: nullptr;
lambda.body->eval(*this, env2, vCur);
} catch (Error & e) {
if (loggerSettings.showTrace.get()) {
@ -1590,8 +1799,8 @@ void EvalState::autoCallFunction(Bindings & args, Value & fun, Value & res)
Nix attempted to evaluate a function as a top level expression; in
this case it must have its arguments supplied either by default
values, or passed explicitly with '--arg' or '--argstr'. See
https://nixos.org/manual/nix/stable/expressions/language-constructs.html#functions.)", symbols[i.name]);
https://nixos.org/manual/nix/stable/expressions/language-constructs.html#functions.)", symbols[i.name],
*fun.lambda.env, *fun.lambda.fun);
}
}
}
@ -1623,7 +1832,7 @@ void ExprAssert::eval(EvalState & state, Env & env, Value & v)
if (!state.evalBool(env, cond, pos)) {
std::ostringstream out;
cond->show(state.symbols, out);
state.throwAssertionError(pos, "assertion '%1%' failed", out.str());
state.throwAssertionError(pos, "assertion '%1%' failed", out.str(), env, *this);
}
body->eval(state, env, v);
}
@ -1800,14 +2009,14 @@ void ExprConcatStrings::eval(EvalState & state, Env & env, Value & v)
nf = n;
nf += vTmp.fpoint;
} else
state.throwEvalError(i_pos, "cannot add %1% to an integer", showType(vTmp));
state.throwEvalError(i_pos, "cannot add %1% to an integer", showType(vTmp), env, *this);
} else if (firstType == nFloat) {
if (vTmp.type() == nInt) {
nf += vTmp.integer;
} else if (vTmp.type() == nFloat) {
nf += vTmp.fpoint;
} else
state.throwEvalError(i_pos, "cannot add %1% to a float", showType(vTmp));
state.throwEvalError(i_pos, "cannot add %1% to a float", showType(vTmp), env, *this);
} else {
if (s.empty()) s.reserve(es->size());
/* skip canonization of first path, which would only be not
@ -1827,7 +2036,7 @@ void ExprConcatStrings::eval(EvalState & state, Env & env, Value & v)
v.mkFloat(nf);
else if (firstType == nPath) {
if (!context.empty())
state.throwEvalError(pos, "a string that refers to a store path cannot be appended to a path");
state.throwEvalError(pos, "a string that refers to a store path cannot be appended to a path", env, *this);
v.mkPath(canonPath(str()));
} else
v.mkStringMove(c_str(), context);
@ -1854,6 +2063,12 @@ void EvalState::forceValueDeep(Value & v)
if (v.type() == nAttrs) {
for (auto & i : *v.attrs)
try {
// If the value is a thunk, we're evaling. Otherwise no trace necessary.
auto dts = debugRepl && i.value->isThunk()
? makeDebugTraceStacker(*this, *i.value->thunk.expr, *i.value->thunk.env, positions[i.pos],
"while evaluating the attribute '%1%'", symbols[i.name])
: nullptr;
recurse(*i.value);
} catch (Error & e) {
addErrorTrace(e, i.pos, "while evaluating the attribute '%1%'", symbols[i.name]);
@ -1876,6 +2091,7 @@ NixInt EvalState::forceInt(Value & v, const PosIdx pos)
forceValue(v, pos);
if (v.type() != nInt)
throwTypeError(pos, "value is %1% while an integer was expected", v);
return v.integer;
}
@ -1918,10 +2134,7 @@ std::string_view EvalState::forceString(Value & v, const PosIdx pos)
{
forceValue(v, pos);
if (v.type() != nString) {
if (pos)
throwTypeError(pos, "value is %1% while a string was expected", v);
else
throwTypeError("value is %1% while a string was expected", v);
}
return v.string.s;
}
@ -2038,7 +2251,8 @@ BackedStringView EvalState::coerceToString(const PosIdx pos, Value & v, PathSet
if (maybeString)
return std::move(*maybeString);
auto i = v.attrs->find(sOutPath);
if (i == v.attrs->end()) throwTypeError(pos, "cannot coerce a set to a string");
if (i == v.attrs->end())
throwTypeError(pos, "cannot coerce a set to a string");
return coerceToString(pos, *i->value, context, coerceMore, copyToStore);
}
@ -2046,7 +2260,6 @@ BackedStringView EvalState::coerceToString(const PosIdx pos, Value & v, PathSet
return v.external->coerceToString(positions[pos], context, coerceMore, copyToStore);
if (coerceMore) {
/* Note that `false' is represented as an empty string for
shell scripting convenience, just like `null'. */
if (v.type() == nBool && v.boolean) return "1";
@ -2191,7 +2404,9 @@ bool EvalState::eqValues(Value & v1, Value & v2)
return v1.fpoint == v2.fpoint;
default:
throwEvalError("cannot compare %1% with %2%", showType(v1), showType(v2));
throwEvalError("cannot compare %1% with %2%",
showType(v1),
showType(v2));
}
}

150
src/libexpr/eval.hh
View file

@ -13,7 +13,6 @@
#include <unordered_map>
#include <mutex>
namespace nix {
@ -25,7 +24,6 @@ enum RepairFlag : bool;
typedef void (* PrimOpFun) (EvalState & state, const PosIdx pos, Value * * args, Value & v);
struct PrimOp
{
PrimOpFun fun;
@ -35,6 +33,11 @@ struct PrimOp
const char * doc = nullptr;
};
#if HAVE_BOEHMGC
typedef std::map<std::string, Value *, std::less<std::string>, traceable_allocator<std::pair<const std::string, Value *> > > ValMap;
#else
typedef std::map<std::string, Value *> ValMap;
#endif
struct Env
{
@ -44,6 +47,10 @@ struct Env
Value * values[0];
};
void printEnvBindings(const EvalState &es, const Expr & expr, const Env & env);
void printEnvBindings(const SymbolTable & st, const StaticEnv & se, const Env & env, int lvl = 0);
std::unique_ptr<ValMap> mapStaticEnvBindings(const SymbolTable & st, const StaticEnv & se, const Env & env);
void copyContext(const Value & v, PathSet & context);
@ -70,8 +77,17 @@ struct RegexCache;
std::shared_ptr<RegexCache> makeRegexCache();
struct DebugTrace {
std::optional<ErrPos> pos;
const Expr & expr;
const Env & env;
hintformat hint;
bool isError;
};
class EvalState
void debugError(Error * e, Env & env, Expr & expr);
class EvalState : public std::enable_shared_from_this<EvalState>
{
public:
SymbolTable symbols;
@ -109,6 +125,49 @@ public:
RootValue vCallFlake = nullptr;
RootValue vImportedDrvToDerivation = nullptr;
/* Debugger */
void (* debugRepl)(ref<EvalState> es, const ValMap & extraEnv);
bool debugStop;
bool debugQuit;
std::list<DebugTrace> debugTraces;
std::map<const Expr*, const std::shared_ptr<const StaticEnv>> exprEnvs;
const std::shared_ptr<const StaticEnv> getStaticEnv(const Expr & expr) const
{
auto i = exprEnvs.find(&expr);
if (i != exprEnvs.end())
return i->second;
else
return std::shared_ptr<const StaticEnv>();;
}
void runDebugRepl(const Error * error, const Env & env, const Expr & expr);
template<class E>
[[gnu::noinline, gnu::noreturn]]
void debugThrow(E && error, const Env & env, const Expr & expr)
{
if (debugRepl)
runDebugRepl(&error, env, expr);
throw error;
}
template<class E>
[[gnu::noinline, gnu::noreturn]]
void debugThrowLastTrace(E && e)
{
// Call this in the situation where Expr and Env are inaccessible.
// The debugger will start in the last context that's in the
// DebugTrace stack.
if (debugRepl && !debugTraces.empty()) {
const DebugTrace & last = debugTraces.front();
runDebugRepl(&e, last.env, last.expr);
}
throw e;
}
private:
SrcToStore srcToStore;
@ -185,10 +244,10 @@ public:
/* Parse a Nix expression from the specified file. */
Expr * parseExprFromFile(const Path & path);
Expr * parseExprFromFile(const Path & path, StaticEnv & staticEnv);
Expr * parseExprFromFile(const Path & path, std::shared_ptr<StaticEnv> & staticEnv);
/* Parse a Nix expression from the specified string. */
Expr * parseExprFromString(std::string s, const Path & basePath, StaticEnv & staticEnv);
Expr * parseExprFromString(std::string s, const Path & basePath, std::shared_ptr<StaticEnv> & staticEnv);
Expr * parseExprFromString(std::string s, const Path & basePath);
Expr * parseStdin();
@ -198,7 +257,7 @@ public:
trivial (i.e. doesn't require arbitrary computation). */
void evalFile(const Path & path, Value & v, bool mustBeTrivial = false);
/* Like `cacheFile`, but with an already parsed expression. */
/* Like `evalFile`, but with an already parsed expression. */
void cacheFile(
const Path & path,
const Path & resolvedPath,
@ -255,37 +314,68 @@ public:
std::string_view forceStringNoCtx(Value & v, const PosIdx pos = noPos);
[[gnu::noinline, gnu::noreturn]]
void throwEvalError(const PosIdx pos, const char * s) const;
void throwEvalError(const PosIdx pos, const char * s);
[[gnu::noinline, gnu::noreturn]]
void throwTypeError(const PosIdx pos, const char * s, const Value & v) const;
void throwEvalError(const PosIdx pos, const char * s,
Env & env, Expr & expr);
[[gnu::noinline, gnu::noreturn]]
void throwEvalError(const char * s, const std::string & s2) const;
void throwEvalError(const char * s, const std::string & s2);
[[gnu::noinline, gnu::noreturn]]
void throwEvalError(const PosIdx pos, const Suggestions & suggestions, const char * s,
const std::string & s2) const;
void throwEvalError(const PosIdx pos, const char * s, const std::string & s2);
[[gnu::noinline, gnu::noreturn]]
void throwEvalError(const PosIdx pos, const char * s, const std::string & s2) const;
void throwEvalError(const char * s, const std::string & s2,
Env & env, Expr & expr);
[[gnu::noinline, gnu::noreturn]]
void throwEvalError(const char * s, const std::string & s2, const std::string & s3) const;
void throwEvalError(const PosIdx pos, const char * s, const std::string & s2,
Env & env, Expr & expr);
[[gnu::noinline, gnu::noreturn]]
void throwEvalError(const PosIdx pos, const char * s, const std::string & s2, const std::string & s3) const;
void throwEvalError(const char * s, const std::string & s2, const std::string & s3,
Env & env, Expr & expr);
[[gnu::noinline, gnu::noreturn]]
void throwEvalError(const PosIdx p1, const char * s, const Symbol sym, const PosIdx p2) const;
void throwEvalError(const PosIdx pos, const char * s, const std::string & s2, const std::string & s3,
Env & env, Expr & expr);
[[gnu::noinline, gnu::noreturn]]
void throwTypeError(const PosIdx pos, const char * s) const;
void throwEvalError(const PosIdx pos, const char * s, const std::string & s2, const std::string & s3);
[[gnu::noinline, gnu::noreturn]]
void throwTypeError(const PosIdx pos, const char * s, const ExprLambda & fun, const Symbol s2) const;
void throwEvalError(const char * s, const std::string & s2, const std::string & s3);
[[gnu::noinline, gnu::noreturn]]
void throwTypeError(const PosIdx pos, const Suggestions & suggestions, const char * s,
const ExprLambda & fun, const Symbol s2) const;
void throwEvalError(const PosIdx pos, const Suggestions & suggestions, const char * s, const std::string & s2,
Env & env, Expr & expr);
[[gnu::noinline, gnu::noreturn]]
void throwTypeError(const char * s, const Value & v) const;
void throwEvalError(const PosIdx p1, const char * s, const Symbol sym, const PosIdx p2,
Env & env, Expr & expr);
[[gnu::noinline, gnu::noreturn]]
void throwAssertionError(const PosIdx pos, const char * s, const std::string & s1) const;
void throwTypeError(const PosIdx pos, const char * s, const Value & v);
[[gnu::noinline, gnu::noreturn]]
void throwUndefinedVarError(const PosIdx pos, const char * s, const std::string & s1) const;
void throwTypeError(const PosIdx pos, const char * s, const Value & v,
Env & env, Expr & expr);
[[gnu::noinline, gnu::noreturn]]
void throwMissingArgumentError(const PosIdx pos, const char * s, const std::string & s1) const;
void throwTypeError(const PosIdx pos, const char * s);
[[gnu::noinline, gnu::noreturn]]
void throwTypeError(const PosIdx pos, const char * s,
Env & env, Expr & expr);
[[gnu::noinline, gnu::noreturn]]
void throwTypeError(const PosIdx pos, const char * s, const ExprLambda & fun, const Symbol s2,
Env & env, Expr & expr);
[[gnu::noinline, gnu::noreturn]]
void throwTypeError(const PosIdx pos, const Suggestions & suggestions, const char * s, const ExprLambda & fun, const Symbol s2,
Env & env, Expr & expr);
[[gnu::noinline, gnu::noreturn]]
void throwTypeError(const char * s, const Value & v,
Env & env, Expr & expr);
[[gnu::noinline, gnu::noreturn]]
void throwAssertionError(const PosIdx pos, const char * s, const std::string & s1,
Env & env, Expr & expr);
[[gnu::noinline, gnu::noreturn]]
void throwUndefinedVarError(const PosIdx pos, const char * s, const std::string & s1,
Env & env, Expr & expr);
[[gnu::noinline, gnu::noreturn]]
void throwMissingArgumentError(const PosIdx pos, const char * s, const std::string & s1,
Env & env, Expr & expr);
[[gnu::noinline]]
void addErrorTrace(Error & e, const char * s, const std::string & s2) const;
@ -325,7 +415,7 @@ public:
Env & baseEnv;
/* The same, but used during parsing to resolve variables. */
StaticEnv staticBaseEnv; // !!! should be private
std::shared_ptr<StaticEnv> staticBaseEnv; // !!! should be private
private:
@ -366,7 +456,7 @@ private:
friend struct ExprLet;
Expr * parse(char * text, size_t length, FileOrigin origin, const PathView path,
const PathView basePath, StaticEnv & staticEnv);
const PathView basePath, std::shared_ptr<StaticEnv> & staticEnv);
public:
@ -461,6 +551,16 @@ private:
friend struct Value;
};
struct DebugTraceStacker {
DebugTraceStacker(EvalState & evalState, DebugTrace t);
~DebugTraceStacker()
{
// assert(evalState.debugTraces.front() == trace);
evalState.debugTraces.pop_front();
}
EvalState & evalState;
DebugTrace trace;
};
/* Return a string representing the type of the value `v'. */
std::string_view showType(ValueType type);

130
src/libexpr/nixexpr.cc
View file

@ -6,10 +6,8 @@
#include <cstdlib>
namespace nix {
/* Displaying abstract syntax trees. */
static void showString(std::ostream & str, std::string_view s)
@ -294,35 +292,46 @@ std::string showAttrPath(const SymbolTable & symbols, const AttrPath & attrPath)
/* Computing levels/displacements for variables. */
void Expr::bindVars(const EvalState & es, const StaticEnv & env)
void Expr::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
{
abort();
}
void ExprInt::bindVars(const EvalState & es, const StaticEnv & env)
void ExprInt::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
{
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
}
void ExprFloat::bindVars(const EvalState & es, const StaticEnv & env)
void ExprFloat::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
{
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
}
void ExprString::bindVars(const EvalState & es, const StaticEnv & env)
void ExprString::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
{
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
}
void ExprPath::bindVars(const EvalState & es, const StaticEnv & env)
void ExprPath::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
{
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
}
void ExprVar::bindVars(const EvalState & es, const StaticEnv & env)
void ExprVar::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
{
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
/* Check whether the variable appears in the environment. If so,
set its level and displacement. */
const StaticEnv * curEnv;
Level level;
int withLevel = -1;
for (curEnv = &env, level = 0; curEnv; curEnv = curEnv->up, level++) {
for (curEnv = env.get(), level = 0; curEnv; curEnv = curEnv->up, level++) {
if (curEnv->isWith) {
if (withLevel == -1) withLevel = level;
} else {
@ -348,8 +357,11 @@ void ExprVar::bindVars(const EvalState & es, const StaticEnv & env)
this->level = withLevel;
}
void ExprSelect::bindVars(const EvalState & es, const StaticEnv & env)
void ExprSelect::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
{
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
e->bindVars(es, env);
if (def) def->bindVars(es, env);
for (auto & i : attrPath)
@ -357,64 +369,78 @@ void ExprSelect::bindVars(const EvalState & es, const StaticEnv & env)
i.expr->bindVars(es, env);
}
void ExprOpHasAttr::bindVars(const EvalState & es, const StaticEnv & env)
void ExprOpHasAttr::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
{
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
e->bindVars(es, env);
for (auto & i : attrPath)
if (!i.symbol)
i.expr->bindVars(es, env);
}
void ExprAttrs::bindVars(const EvalState & es, const StaticEnv & env)
void ExprAttrs::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
{
const StaticEnv * dynamicEnv = &env;
StaticEnv newEnv(false, &env, recursive ? attrs.size() : 0);
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
if (recursive) {
dynamicEnv = &newEnv;
auto newEnv = std::make_shared<StaticEnv>(false, env.get(), recursive ? attrs.size() : 0);
Displacement displ = 0;
for (auto & i : attrs)
newEnv.vars.emplace_back(i.first, i.second.displ = displ++);
newEnv->vars.emplace_back(i.first, i.second.displ = displ++);
// No need to sort newEnv since attrs is in sorted order.
for (auto & i : attrs)
i.second.e->bindVars(es, i.second.inherited ? env : newEnv);
}
else
for (auto & i : dynamicAttrs) {
i.nameExpr->bindVars(es, newEnv);
i.valueExpr->bindVars(es, newEnv);
}
}
else {
for (auto & i : attrs)
i.second.e->bindVars(es, env);
for (auto & i : dynamicAttrs) {
i.nameExpr->bindVars(es, *dynamicEnv);
i.valueExpr->bindVars(es, *dynamicEnv);
i.nameExpr->bindVars(es, env);
i.valueExpr->bindVars(es, env);
}
}
}
void ExprList::bindVars(const EvalState & es, const StaticEnv & env)
void ExprList::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
{
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
for (auto & i : elems)
i->bindVars(es, env);
}
void ExprLambda::bindVars(const EvalState & es, const StaticEnv & env)
void ExprLambda::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
{
StaticEnv newEnv(
false, &env,
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
auto newEnv = std::make_shared<StaticEnv>(
false, env.get(),
(hasFormals() ? formals->formals.size() : 0) +
(!arg ? 0 : 1));
Displacement displ = 0;
if (arg) newEnv.vars.emplace_back(arg, displ++);
if (arg) newEnv->vars.emplace_back(arg, displ++);
if (hasFormals()) {
for (auto & i : formals->formals)
newEnv.vars.emplace_back(i.name, displ++);
newEnv->vars.emplace_back(i.name, displ++);
newEnv.sort();
newEnv->sort();
for (auto & i : formals->formals)
if (i.def) i.def->bindVars(es, newEnv);
@ -423,20 +449,26 @@ void ExprLambda::bindVars(const EvalState & es, const StaticEnv & env)
body->bindVars(es, newEnv);
}
void ExprCall::bindVars(const EvalState & es, const StaticEnv & env)
void ExprCall::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
{
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
fun->bindVars(es, env);
for (auto e : args)
e->bindVars(es, env);
}
void ExprLet::bindVars(const EvalState & es, const StaticEnv & env)
void ExprLet::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
{
StaticEnv newEnv(false, &env, attrs->attrs.size());
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
auto newEnv = std::make_shared<StaticEnv>(false, env.get(), attrs->attrs.size());
Displacement displ = 0;
for (auto & i : attrs->attrs)
newEnv.vars.emplace_back(i.first, i.second.displ = displ++);
newEnv->vars.emplace_back(i.first, i.second.displ = displ++);
// No need to sort newEnv since attrs->attrs is in sorted order.
@ -446,51 +478,71 @@ void ExprLet::bindVars(const EvalState & es, const StaticEnv & env)
body->bindVars(es, newEnv);
}
void ExprWith::bindVars(const EvalState & es, const StaticEnv & env)
void ExprWith::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
{
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
/* Does this `with' have an enclosing `with'? If so, record its
level so that `lookupVar' can look up variables in the previous
`with' if this one doesn't contain the desired attribute. */
const StaticEnv * curEnv;
Level level;
prevWith = 0;
for (curEnv = &env, level = 1; curEnv; curEnv = curEnv->up, level++)
for (curEnv = env.get(), level = 1; curEnv; curEnv = curEnv->up, level++)
if (curEnv->isWith) {
prevWith = level;
break;
}
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
attrs->bindVars(es, env);
StaticEnv newEnv(true, &env);
auto newEnv = std::make_shared<StaticEnv>(true, env.get());
body->bindVars(es, newEnv);
}
void ExprIf::bindVars(const EvalState & es, const StaticEnv & env)
void ExprIf::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
{
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
cond->bindVars(es, env);
then->bindVars(es, env);
else_->bindVars(es, env);
}
void ExprAssert::bindVars(const EvalState & es, const StaticEnv & env)
void ExprAssert::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
{
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
cond->bindVars(es, env);
body->bindVars(es, env);
}
void ExprOpNot::bindVars(const EvalState & es, const StaticEnv & env)
void ExprOpNot::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
{
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
e->bindVars(es, env);
}
void ExprConcatStrings::bindVars(const EvalState & es, const StaticEnv & env)
void ExprConcatStrings::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
{
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
for (auto & i : *this->es)
i.second->bindVars(es, env);
}
void ExprPos::bindVars(const EvalState & es, const StaticEnv & env)
void ExprPos::bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)
{
if (es.debugRepl)
es.exprEnvs.insert(std::make_pair(this, env));
}

35
src/libexpr/nixexpr.hh
View file

@ -22,7 +22,6 @@ MakeError(UndefinedVarError, Error);
MakeError(MissingArgumentError, EvalError);
MakeError(RestrictedPathError, Error);
/* Position objects. */
struct Pos
@ -143,24 +142,25 @@ struct Expr
{
virtual ~Expr() { };
virtual void show(const SymbolTable & symbols, std::ostream & str) const;
virtual void bindVars(const EvalState & es, const StaticEnv & env);
virtual void bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env);
virtual void eval(EvalState & state, Env & env, Value & v);
virtual Value * maybeThunk(EvalState & state, Env & env);
virtual void setName(Symbol name);
virtual PosIdx getPos() const { return noPos; }
};
#define COMMON_METHODS \
void show(const SymbolTable & symbols, std::ostream & str) const; \
void eval(EvalState & state, Env & env, Value & v); \
void bindVars(const EvalState & es, const StaticEnv & env);
void bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env);
struct ExprInt : Expr
{
NixInt n;
Value v;
ExprInt(NixInt n) : n(n) { v.mkInt(n); };
COMMON_METHODS
Value * maybeThunk(EvalState & state, Env & env);
COMMON_METHODS
};
struct ExprFloat : Expr
@ -168,8 +168,8 @@ struct ExprFloat : Expr
NixFloat nf;
Value v;
ExprFloat(NixFloat nf) : nf(nf) { v.mkFloat(nf); };
COMMON_METHODS
Value * maybeThunk(EvalState & state, Env & env);
COMMON_METHODS
};
struct ExprString : Expr
@ -177,8 +177,8 @@ struct ExprString : Expr
std::string s;
Value v;
ExprString(std::string s) : s(std::move(s)) { v.mkString(this->s.data()); };
COMMON_METHODS
Value * maybeThunk(EvalState & state, Env & env);
COMMON_METHODS
};
struct ExprPath : Expr
@ -186,8 +186,8 @@ struct ExprPath : Expr
std::string s;
Value v;
ExprPath(std::string s) : s(std::move(s)) { v.mkPath(this->s.c_str()); };
COMMON_METHODS
Value * maybeThunk(EvalState & state, Env & env);
COMMON_METHODS
};
typedef uint32_t Level;
@ -213,8 +213,9 @@ struct ExprVar : Expr
ExprVar(Symbol name) : name(name) { };
ExprVar(const PosIdx & pos, Symbol name) : pos(pos), name(name) { };
COMMON_METHODS
Value * maybeThunk(EvalState & state, Env & env);
PosIdx getPos() const override { return pos; }
COMMON_METHODS
};
struct ExprSelect : Expr
@ -224,6 +225,7 @@ struct ExprSelect : Expr
AttrPath attrPath;
ExprSelect(const PosIdx & pos, Expr * e, const AttrPath & attrPath, Expr * def) : pos(pos), e(e), def(def), attrPath(attrPath) { };
ExprSelect(const PosIdx & pos, Expr * e, Symbol name) : pos(pos), e(e), def(0) { attrPath.push_back(AttrName(name)); };
PosIdx getPos() const override { return pos; }
COMMON_METHODS
};
@ -232,6 +234,7 @@ struct ExprOpHasAttr : Expr
Expr * e;
AttrPath attrPath;
ExprOpHasAttr(Expr * e, const AttrPath & attrPath) : e(e), attrPath(attrPath) { };
PosIdx getPos() const override { return e->getPos(); }
COMMON_METHODS
};
@ -260,6 +263,7 @@ struct ExprAttrs : Expr
DynamicAttrDefs dynamicAttrs;
ExprAttrs(const PosIdx &pos) : recursive(false), pos(pos) { };
ExprAttrs() : recursive(false) { };
PosIdx getPos() const override { return pos; }
COMMON_METHODS
};
@ -268,6 +272,11 @@ struct ExprList : Expr
std::vector<Expr *> elems;
ExprList() { };
COMMON_METHODS
PosIdx getPos() const override
{
return elems.empty() ? noPos : elems.front()->getPos();
}
};
struct Formal
@ -320,6 +329,7 @@ struct ExprLambda : Expr
void setName(Symbol name);
std::string showNamePos(const EvalState & state) const;
inline bool hasFormals() const { return formals != nullptr; }
PosIdx getPos() const override { return pos; }
COMMON_METHODS
};
@ -331,6 +341,7 @@ struct ExprCall : Expr
ExprCall(const PosIdx & pos, Expr * fun, std::vector<Expr *> && args)
: fun(fun), args(args), pos(pos)
{ }
PosIdx getPos() const override { return pos; }
COMMON_METHODS
};
@ -348,6 +359,7 @@ struct ExprWith : Expr
Expr * attrs, * body;
size_t prevWith;
ExprWith(const PosIdx & pos, Expr * attrs, Expr * body) : pos(pos), attrs(attrs), body(body) { };
PosIdx getPos() const override { return pos; }
COMMON_METHODS
};
@ -356,6 +368,7 @@ struct ExprIf : Expr
PosIdx pos;
Expr * cond, * then, * else_;
ExprIf(const PosIdx & pos, Expr * cond, Expr * then, Expr * else_) : pos(pos), cond(cond), then(then), else_(else_) { };
PosIdx getPos() const override { return pos; }
COMMON_METHODS
};
@ -364,6 +377,7 @@ struct ExprAssert : Expr
PosIdx pos;
Expr * cond, * body;
ExprAssert(const PosIdx & pos, Expr * cond, Expr * body) : pos(pos), cond(cond), body(body) { };
PosIdx getPos() const override { return pos; }
COMMON_METHODS
};
@ -385,11 +399,12 @@ struct ExprOpNot : Expr
{ \
str << "("; e1->show(symbols, str); str << " " s " "; e2->show(symbols, str); str << ")"; \
} \
void bindVars(const EvalState & es, const StaticEnv & env) \
void bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env) \
{ \
e1->bindVars(es, env); e2->bindVars(es, env); \
} \
void eval(EvalState & state, Env & env, Value & v); \
PosIdx getPos() const override { return pos; } \
};
MakeBinOp(ExprOpEq, "==")
@ -407,6 +422,7 @@ struct ExprConcatStrings : Expr
std::vector<std::pair<PosIdx, Expr *> > * es;
ExprConcatStrings(const PosIdx & pos, bool forceString, std::vector<std::pair<PosIdx, Expr *> > * es)
: pos(pos), forceString(forceString), es(es) { };
PosIdx getPos() const override { return pos; }
COMMON_METHODS
};
@ -414,6 +430,7 @@ struct ExprPos : Expr
{
PosIdx pos;
ExprPos(const PosIdx & pos) : pos(pos) { };
PosIdx getPos() const override { return pos; }
COMMON_METHODS
};

10
src/libexpr/parser.y
View file

@ -643,7 +643,7 @@ namespace nix {
Expr * EvalState::parse(char * text, size_t length, FileOrigin origin,
const PathView path, const PathView basePath, StaticEnv & staticEnv)
const PathView path, const PathView basePath, std::shared_ptr<StaticEnv> & staticEnv)
{
yyscan_t scanner;
std::string file;
@ -706,7 +706,7 @@ Expr * EvalState::parseExprFromFile(const Path & path)
}
Expr * EvalState::parseExprFromFile(const Path & path, StaticEnv & staticEnv)
Expr * EvalState::parseExprFromFile(const Path & path, std::shared_ptr<StaticEnv> & staticEnv)
{
auto buffer = readFile(path);
// readFile should have left some extra space for terminators
@ -715,7 +715,7 @@ Expr * EvalState::parseExprFromFile(const Path & path, StaticEnv & staticEnv)
}
Expr * EvalState::parseExprFromString(std::string s, const Path & basePath, StaticEnv & staticEnv)
Expr * EvalState::parseExprFromString(std::string s, const Path & basePath, std::shared_ptr<StaticEnv> & staticEnv)
{
s.append("\0\0", 2);
return parse(s.data(), s.size(), foString, "", basePath, staticEnv);
@ -782,13 +782,13 @@ Path EvalState::findFile(SearchPath & searchPath, const std::string_view path, c
if (hasPrefix(path, "nix/"))
return concatStrings(corepkgsPrefix, path.substr(4));
throw ThrownError({
debugThrowLastTrace(ThrownError({
.msg = hintfmt(evalSettings.pureEval
? "cannot look up '<%s>' in pure evaluation mode (use '--impure' to override)"
: "file '%s' was not found in the Nix search path (add it using $NIX_PATH or -I)",
path),
.errPos = positions[pos]
});
}));
}

218
src/libexpr/primops.cc
View file

@ -46,7 +46,7 @@ StringMap EvalState::realiseContext(const PathSet & context)
auto [ctx, outputName] = decodeContext(*store, i);
auto ctxS = store->printStorePath(ctx);
if (!store->isValidPath(ctx))
throw InvalidPathError(store->printStorePath(ctx));
debugThrowLastTrace(InvalidPathError(store->printStorePath(ctx)));
if (!outputName.empty() && ctx.isDerivation()) {
drvs.push_back({ctx, {outputName}});
} else {
@ -57,9 +57,9 @@ StringMap EvalState::realiseContext(const PathSet & context)
if (drvs.empty()) return {};
if (!evalSettings.enableImportFromDerivation)
throw Error(
debugThrowLastTrace(Error(
"cannot build '%1%' during evaluation because the option 'allow-import-from-derivation' is disabled",
store->printStorePath(drvs.begin()->drvPath));
store->printStorePath(drvs.begin()->drvPath)));
/* Build/substitute the context. */
std::vector<DerivedPath> buildReqs;
@ -72,8 +72,8 @@ StringMap EvalState::realiseContext(const PathSet & context)
for (auto & outputName : outputs) {
auto outputPath = get(outputPaths, outputName);
if (!outputPath)
throw Error("derivation '%s' does not have an output named '%s'",
store->printStorePath(drvPath), outputName);
debugThrowLastTrace(Error("derivation '%s' does not have an output named '%s'",
store->printStorePath(drvPath), outputName));
res.insert_or_assign(
downstreamPlaceholder(*store, drvPath, outputName),
store->printStorePath(*outputPath)
@ -216,11 +216,11 @@ static void import(EvalState & state, const PosIdx pos, Value & vPath, Value * v
Env * env = &state.allocEnv(vScope->attrs->size());
env->up = &state.baseEnv;
StaticEnv staticEnv(false, &state.staticBaseEnv, vScope->attrs->size());
auto staticEnv = std::make_shared<StaticEnv>(false, state.staticBaseEnv.get(), vScope->attrs->size());
unsigned int displ = 0;
for (auto & attr : *vScope->attrs) {
staticEnv.vars.emplace_back(attr.name, displ);
staticEnv->vars.emplace_back(attr.name, displ);
env->values[displ++] = attr.value;
}
@ -319,17 +319,16 @@ void prim_importNative(EvalState & state, const PosIdx pos, Value * * args, Valu
void *handle = dlopen(path.c_str(), RTLD_LAZY | RTLD_LOCAL);
if (!handle)
throw EvalError("could not open '%1%': %2%", path, dlerror());
state.debugThrowLastTrace(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);
state.debugThrowLastTrace(EvalError("could not load symbol '%1%' from '%2%': %3%", sym, path, message));
else
throw EvalError("symbol '%1%' from '%2%' resolved to NULL when a function pointer was expected",
sym, path);
state.debugThrowLastTrace(EvalError("symbol '%1%' from '%2%' resolved to NULL when a function pointer was expected", sym, path));
}
(func)(state, v);
@ -344,12 +343,11 @@ void prim_exec(EvalState & state, const PosIdx 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({
if (count == 0)
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("at least one argument to 'exec' required"),
.errPos = state.positions[pos]
});
}
}));
PathSet context;
auto program = state.coerceToString(pos, *elems[0], context, false, false).toOwned();
Strings commandArgs;
@ -359,11 +357,11 @@ void prim_exec(EvalState & state, const PosIdx pos, Value * * args, Value & v)
try {
auto _ = state.realiseContext(context); // FIXME: Handle CA derivations
} catch (InvalidPathError & e) {
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("cannot execute '%1%', since path '%2%' is not valid",
program, e.path),
.errPos = state.positions[pos]
});
}));
}
auto output = runProgram(program, true, commandArgs);
@ -547,7 +545,7 @@ struct CompareValues
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));
state.debugThrowLastTrace(EvalError("cannot compare %1% with %2%", showType(*v1), showType(*v2)));
switch (v1->type()) {
case nInt:
return v1->integer < v2->integer;
@ -569,7 +567,7 @@ struct CompareValues
}
}
default:
throw EvalError("cannot compare %1% with %2%", showType(*v1), showType(*v2));
state.debugThrowLastTrace(EvalError("cannot compare %1% with %2%", showType(*v1), showType(*v2)));
}
}
};
@ -599,10 +597,10 @@ static Bindings::iterator getAttr(
auto aPos = attrSet->pos;
if (!aPos) {
throw TypeError({
state.debugThrowLastTrace(TypeError({
.msg = errorMsg,
.errPos = state.positions[pos],
});
}));
} else {
auto e = TypeError({
.msg = errorMsg,
@ -612,7 +610,7 @@ static Bindings::iterator getAttr(
// Adding another trace for the function name to make it clear
// which call received wrong arguments.
e.addTrace(state.positions[pos], hintfmt("while invoking '%s'", funcName));
throw e;
state.debugThrowLastTrace(e);
}
}
@ -666,10 +664,10 @@ static void prim_genericClosure(EvalState & state, const PosIdx pos, Value * * a
Bindings::iterator key =
e->attrs->find(state.sKey);
if (key == e->attrs->end())
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("attribute 'key' required"),
.errPos = state.positions[pos]
});
}));
state.forceValue(*key->value, pos);
if (!doneKeys.insert(key->value).second) continue;
@ -725,6 +723,41 @@ static RegisterPrimOp primop_genericClosure(RegisterPrimOp::Info {
.fun = prim_genericClosure,
});
static RegisterPrimOp primop_break({
.name = "break",
.args = {"v"},
.doc = R"(
In debug mode (enabled using `--debugger`), pause Nix expression evaluation and enter the REPL.
Otherwise, return the argument `v`.
)",
.fun = [](EvalState & state, const PosIdx pos, Value * * args, Value & v)
{
if (state.debugRepl && !state.debugTraces.empty()) {
auto error = Error(ErrorInfo {
.level = lvlInfo,
.msg = hintfmt("breakpoint reached"),
.errPos = state.positions[pos],
});
auto & dt = state.debugTraces.front();
state.runDebugRepl(&error, dt.env, dt.expr);
if (state.debugQuit) {
// If the user elects to quit the repl, throw an exception.
throw Error(ErrorInfo{
.level = lvlInfo,
.msg = hintfmt("quit the debugger"),
.errPos = state.positions[noPos],
});
}
}
// Return the value we were passed.
v = *args[0];
}
});
static RegisterPrimOp primop_abort({
.name = "abort",
.args = {"s"},
@ -735,7 +768,7 @@ static RegisterPrimOp primop_abort({
{
PathSet context;
auto s = state.coerceToString(pos, *args[0], context).toOwned();
throw Abort("evaluation aborted with the following error message: '%1%'", s);
state.debugThrowLastTrace(Abort("evaluation aborted with the following error message: '%1%'", s));
}
});
@ -753,7 +786,7 @@ static RegisterPrimOp primop_throw({
{
PathSet context;
auto s = state.coerceToString(pos, *args[0], context).toOwned();
throw ThrownError(s);
state.debugThrowLastTrace(ThrownError(s));
}
});
@ -1008,37 +1041,37 @@ static void prim_derivationStrict(EvalState & state, const PosIdx pos, Value * *
if (s == "recursive") ingestionMethod = FileIngestionMethod::Recursive;
else if (s == "flat") ingestionMethod = FileIngestionMethod::Flat;
else
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("invalid value '%s' for 'outputHashMode' attribute", s),
.errPos = state.positions[posDrvName]
});
}));
};
auto handleOutputs = [&](const Strings & ss) {
outputs.clear();
for (auto & j : ss) {
if (outputs.find(j) != outputs.end())
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("duplicate derivation output '%1%'", j),
.errPos = state.positions[posDrvName]
});
}));
/* !!! 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({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("invalid derivation output name 'drv'" ),
.errPos = state.positions[posDrvName]
});
}));
outputs.insert(j);
}
if (outputs.empty())
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("derivation cannot have an empty set of outputs"),
.errPos = state.positions[posDrvName]
});
}));
};
try {
@ -1163,23 +1196,23 @@ static void prim_derivationStrict(EvalState & state, const PosIdx pos, Value * *
/* Do we have all required attributes? */
if (drv.builder == "")
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("required attribute 'builder' missing"),
.errPos = state.positions[posDrvName]
});
}));
if (drv.platform == "")
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("required attribute 'system' missing"),
.errPos = state.positions[posDrvName]
});
}));
/* Check whether the derivation name is valid. */
if (isDerivation(drvName))
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("derivation names are not allowed to end in '%s'", drvExtension),
.errPos = state.positions[posDrvName]
});
}));
if (outputHash) {
/* Handle fixed-output derivations.
@ -1187,10 +1220,10 @@ static void prim_derivationStrict(EvalState & state, const PosIdx pos, Value * *
Ignore `__contentAddressed` because fixed output derivations are
already content addressed. */
if (outputs.size() != 1 || *(outputs.begin()) != "out")
throw Error({
state.debugThrowLastTrace(Error({
.msg = hintfmt("multiple outputs are not supported in fixed-output derivations"),
.errPos = state.positions[posDrvName]
});
}));
auto h = newHashAllowEmpty(*outputHash, parseHashTypeOpt(outputHashAlgo));
@ -1358,10 +1391,10 @@ static RegisterPrimOp primop_toPath({
static void prim_storePath(EvalState & state, const PosIdx pos, Value * * args, Value & v)
{
if (evalSettings.pureEval)
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("'%s' is not allowed in pure evaluation mode", "builtins.storePath"),
.errPos = state.positions[pos]
});
}));
PathSet context;
Path path = state.checkSourcePath(state.coerceToPath(pos, *args[0], context));
@ -1370,10 +1403,10 @@ static void prim_storePath(EvalState & state, const PosIdx pos, Value * * args,
e.g. nix-push does the right thing. */
if (!state.store->isStorePath(path)) path = canonPath(path, true);
if (!state.store->isInStore(path))
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("path '%1%' is not in the Nix store", path),
.errPos = state.positions[pos]
});
}));
auto path2 = state.store->toStorePath(path).first;
if (!settings.readOnlyMode)
state.store->ensurePath(path2);
@ -1476,7 +1509,7 @@ static void prim_readFile(EvalState & state, const PosIdx pos, Value * * args, V
auto path = realisePath(state, pos, *args[0]);
auto s = readFile(path);
if (s.find((char) 0) != std::string::npos)
throw Error("the contents of the file '%1%' cannot be represented as a Nix string", path);
state.debugThrowLastTrace(Error("the contents of the file '%1%' cannot be represented as a Nix string", path));
StorePathSet refs;
if (state.store->isInStore(path)) {
try {
@ -1528,13 +1561,12 @@ static void prim_findFile(EvalState & state, const PosIdx pos, Value * * args, V
auto rewrites = state.realiseContext(context);
path = rewriteStrings(path, rewrites);
} catch (InvalidPathError & e) {
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("cannot find '%1%', since path '%2%' is not valid", path, e.path),
.errPos = state.positions[pos]
});
}));
}
searchPath.emplace_back(prefix, path);
}
@ -1555,10 +1587,10 @@ static void prim_hashFile(EvalState & state, const PosIdx pos, Value * * args, V
auto type = state.forceStringNoCtx(*args[0], pos);
std::optional<HashType> ht = parseHashType(type);
if (!ht)
throw Error({
state.debugThrowLastTrace(Error({
.msg = hintfmt("unknown hash type '%1%'", type),
.errPos = state.positions[pos]
});
}));
auto path = realisePath(state, pos, *args[1]);
@ -1795,13 +1827,13 @@ static void prim_toFile(EvalState & state, const PosIdx pos, Value * * args, Val
for (auto path : context) {
if (path.at(0) != '/')
throw EvalError( {
state.debugThrowLastTrace(EvalError({
.msg = hintfmt(
"in 'toFile': the file named '%1%' must not contain a reference "
"to a derivation but contains (%2%)",
name, path),
.errPos = state.positions[pos]
});
}));
refs.insert(state.store->parseStorePath(path));
}
@ -1959,7 +1991,7 @@ static void addPath(
? state.store->computeStorePathForPath(name, path, method, htSHA256, filter).first
: state.store->addToStore(name, path, method, htSHA256, filter, state.repair, refs);
if (expectedHash && expectedStorePath != dstPath)
throw Error("store path mismatch in (possibly filtered) path added from '%s'", path);
state.debugThrowLastTrace(Error("store path mismatch in (possibly filtered) path added from '%s'", path));
state.allowAndSetStorePathString(dstPath, v);
} else
state.allowAndSetStorePathString(*expectedStorePath, v);
@ -1977,12 +2009,12 @@ static void prim_filterSource(EvalState & state, const PosIdx pos, Value * * arg
state.forceValue(*args[0], pos);
if (args[0]->type() != nFunction)
throw TypeError({
state.debugThrowLastTrace(TypeError({
.msg = hintfmt(
"first argument in call to 'filterSource' is not a function but %1%",
showType(*args[0])),
.errPos = state.positions[pos]
});
}));
addPath(state, pos, std::string(baseNameOf(path)), path, args[0], FileIngestionMethod::Recursive, std::nullopt, v, context);
}
@ -2066,16 +2098,16 @@ static void prim_path(EvalState & state, const PosIdx pos, Value * * args, Value
else if (n == "sha256")
expectedHash = newHashAllowEmpty(state.forceStringNoCtx(*attr.value, attr.pos), htSHA256);
else
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("unsupported argument '%1%' to 'addPath'", state.symbols[attr.name]),
.errPos = state.positions[attr.pos]
});
}));
}
if (path.empty())
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("'path' required"),
.errPos = state.positions[pos]
});
}));
if (name.empty())
name = baseNameOf(path);
@ -2447,10 +2479,10 @@ static void prim_functionArgs(EvalState & state, const PosIdx pos, Value * * arg
return;
}
if (!args[0]->isLambda())
throw TypeError({
state.debugThrowLastTrace(TypeError({
.msg = hintfmt("'functionArgs' requires a function"),
.errPos = state.positions[pos]
});
}));
if (!args[0]->lambda.fun->hasFormals()) {
v.mkAttrs(&state.emptyBindings);
@ -2538,7 +2570,7 @@ static void prim_zipAttrsWith(EvalState & state, const PosIdx pos, Value * * arg
attrsSeen[attr.name].first++;
} catch (TypeError & e) {
e.addTrace(state.positions[pos], hintfmt("while invoking '%s'", "zipAttrsWith"));
throw;
state.debugThrowLastTrace(e);
}
}
@ -2625,10 +2657,10 @@ static void elemAt(EvalState & state, const PosIdx pos, Value & list, int n, Val
{
state.forceList(list, pos);
if (n < 0 || (unsigned int) n >= list.listSize())
throw Error({
state.debugThrowLastTrace(Error({
.msg = hintfmt("list index %1% is out of bounds", n),
.errPos = state.positions[pos]
});
}));
state.forceValue(*list.listElems()[n], pos);
v = *list.listElems()[n];
}
@ -2673,10 +2705,10 @@ static void prim_tail(EvalState & state, const PosIdx pos, Value * * args, Value
{
state.forceList(*args[0], pos);
if (args[0]->listSize() == 0)
throw Error({
state.debugThrowLastTrace(Error({
.msg = hintfmt("'tail' called on an empty list"),
.errPos = state.positions[pos]
});
}));
state.mkList(v, args[0]->listSize() - 1);
for (unsigned int n = 0; n < v.listSize(); ++n)
@ -2911,10 +2943,10 @@ static void prim_genList(EvalState & state, const PosIdx pos, Value * * args, Va
auto len = state.forceInt(*args[1], pos);
if (len < 0)
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("cannot create list of size %1%", len),
.errPos = state.positions[pos]
});
}));
state.mkList(v, len);
@ -3123,7 +3155,7 @@ static void prim_concatMap(EvalState & state, const PosIdx pos, Value * * args,
state.forceList(lists[n], lists[n].determinePos(args[0]->determinePos(pos)));
} catch (TypeError &e) {
e.addTrace(state.positions[pos], hintfmt("while invoking '%s'", "concatMap"));
throw;
state.debugThrowLastTrace(e);
}
len += lists[n].listSize();
}
@ -3218,10 +3250,10 @@ static void prim_div(EvalState & state, const PosIdx pos, Value * * args, Value
NixFloat f2 = state.forceFloat(*args[1], pos);
if (f2 == 0)
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("division by zero"),
.errPos = state.positions[pos]
});
}));
if (args[0]->type() == nFloat || args[1]->type() == nFloat) {
v.mkFloat(state.forceFloat(*args[0], pos) / state.forceFloat(*args[1], pos));
@ -3230,10 +3262,10 @@ static void prim_div(EvalState & state, const PosIdx pos, Value * * args, Value
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({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("overflow in integer division"),
.errPos = state.positions[pos]
});
}));
v.mkInt(i1 / i2);
}
@ -3361,10 +3393,10 @@ static void prim_substring(EvalState & state, const PosIdx pos, Value * * args,
auto s = state.coerceToString(pos, *args[2], context);
if (start < 0)
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("negative start position in 'substring'"),
.errPos = state.positions[pos]
});
}));
v.mkString((unsigned int) start >= s->size() ? "" : s->substr(start, len), context);
}
@ -3412,10 +3444,10 @@ static void prim_hashString(EvalState & state, const PosIdx pos, Value * * args,
auto type = state.forceStringNoCtx(*args[0], pos);
std::optional<HashType> ht = parseHashType(type);
if (!ht)
throw Error({
state.debugThrowLastTrace(Error({
.msg = hintfmt("unknown hash type '%1%'", type),
.errPos = state.positions[pos]
});
}));
PathSet context; // discarded
auto s = state.forceString(*args[1], context, pos);
@ -3485,16 +3517,15 @@ void prim_match(EvalState & state, const PosIdx pos, Value * * args, Value & v)
} catch (std::regex_error &e) {
if (e.code() == std::regex_constants::error_space) {
// limit is _GLIBCXX_REGEX_STATE_LIMIT for libstdc++
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("memory limit exceeded by regular expression '%s'", re),
.errPos = state.positions[pos]
});
} else {
throw EvalError({
}));
} else
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("invalid regular expression '%s'", re),
.errPos = state.positions[pos]
});
}
}));
}
}
@ -3590,16 +3621,15 @@ void prim_split(EvalState & state, const PosIdx pos, Value * * args, Value & v)
} catch (std::regex_error &e) {
if (e.code() == std::regex_constants::error_space) {
// limit is _GLIBCXX_REGEX_STATE_LIMIT for libstdc++
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("memory limit exceeded by regular expression '%s'", re),
.errPos = state.positions[pos]
});
} else {
throw EvalError({
}));
} else
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("invalid regular expression '%s'", re),
.errPos = state.positions[pos]
});
}
}));
}
}
@ -3675,10 +3705,10 @@ static void prim_replaceStrings(EvalState & state, const PosIdx pos, Value * * a
state.forceList(*args[0], pos);
state.forceList(*args[1], pos);
if (args[0]->listSize() != args[1]->listSize())
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("'from' and 'to' arguments to 'replaceStrings' have different lengths"),
.errPos = state.positions[pos]
});
}));
std::vector<std::string> from;
from.reserve(args[0]->listSize());
@ -3931,7 +3961,7 @@ void EvalState::createBaseEnv()
because attribute lookups expect it to be sorted. */
baseEnv.values[0]->attrs->sort();
staticBaseEnv.sort();
staticBaseEnv->sort();
/* Note: we have to initialize the 'derivation' constant *after*
building baseEnv/staticBaseEnv because it uses 'builtins'. */

34
src/libexpr/primops/fetchTree.cc
View file

@ -108,16 +108,16 @@ static void fetchTree(
if (auto aType = args[0]->attrs->get(state.sType)) {
if (type)
throw Error({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("unexpected attribute 'type'"),
.errPos = state.positions[pos]
});
}));
type = state.forceStringNoCtx(*aType->value, aType->pos);
} else if (!type)
throw Error({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("attribute 'type' is missing in call to 'fetchTree'"),
.errPos = state.positions[pos]
});
}));
attrs.emplace("type", type.value());
@ -138,16 +138,16 @@ static void fetchTree(
else if (attr.value->type() == nInt)
attrs.emplace(state.symbols[attr.name], uint64_t(attr.value->integer));
else
throw TypeError("fetchTree argument '%s' is %s while a string, Boolean or integer is expected",
state.symbols[attr.name], showType(*attr.value));
state.debugThrowLastTrace(TypeError("fetchTree argument '%s' is %s while a string, Boolean or integer is expected",
state.symbols[attr.name], showType(*attr.value)));
}
if (!params.allowNameArgument)
if (auto nameIter = attrs.find("name"); nameIter != attrs.end())
throw Error({
.msg = hintfmt("attribute 'name' isn't supported in call to 'fetchTree'"),
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("attribute 'name' isn’t supported in call to 'fetchTree'"),
.errPos = state.positions[pos]
});
}));
input = fetchers::Input::fromAttrs(std::move(attrs));
} else {
@ -167,7 +167,7 @@ static void fetchTree(
input = lookupInRegistries(state.store, input).first;
if (evalSettings.pureEval && !input.isLocked())
throw Error("in pure evaluation mode, 'fetchTree' requires a locked input, at %s", state.positions[pos]);
state.debugThrowLastTrace(EvalError("in pure evaluation mode, 'fetchTree' requires a locked input, at %s", state.positions[pos]));
auto [tree, input2] = input.fetch(state.store);
@ -206,17 +206,17 @@ static void fetch(EvalState & state, const PosIdx pos, Value * * args, Value & v
else if (n == "name")
name = state.forceStringNoCtx(*attr.value, attr.pos);
else
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("unsupported argument '%s' to '%s'", n, who),
.errPos = state.positions[attr.pos]
});
}));
}
if (!url)
throw EvalError({
state.debugThrowLastTrace(EvalError({
.msg = hintfmt("'url' argument required"),
.errPos = state.positions[pos]
});
}));
} else
url = state.forceStringNoCtx(*args[0], pos);
@ -228,7 +228,7 @@ static void fetch(EvalState & state, const PosIdx pos, Value * * args, Value & v
name = baseNameOf(*url);
if (evalSettings.pureEval && !expectedHash)
throw Error("in pure evaluation mode, '%s' requires a 'sha256' argument", who);
state.debugThrowLastTrace(EvalError("in pure evaluation mode, '%s' requires a 'sha256' argument", who));
// early exit if pinned and already in the store
if (expectedHash && expectedHash->type == htSHA256) {
@ -255,8 +255,8 @@ static void fetch(EvalState & state, const PosIdx pos, Value * * args, Value & v
? state.store->queryPathInfo(storePath)->narHash
: hashFile(htSHA256, state.store->toRealPath(storePath));
if (hash != *expectedHash)
throw Error((unsigned int) 102, "hash mismatch in file downloaded from '%s':\n specified: %s\n got: %s",
*url, expectedHash->to_string(Base32, true), hash.to_string(Base32, true));
state.debugThrowLastTrace(EvalError((unsigned int) 102, "hash mismatch in file downloaded from '%s':\n specified: %s\n got: %s",
*url, expectedHash->to_string(Base32, true), hash.to_string(Base32, true)));
}
state.allowAndSetStorePathString(storePath, v);

3
src/libexpr/value-to-json.cc
View file

@ -85,6 +85,7 @@ void printValueAsJSON(EvalState & state, bool strict,
.errPos = state.positions[v.determinePos(pos)]
});
e.addTrace(state.positions[pos], hintfmt("message for the trace"));
state.debugThrowLastTrace(e);
throw e;
}
}
@ -99,7 +100,7 @@ void printValueAsJSON(EvalState & state, bool strict,
void ExternalValueBase::printValueAsJSON(EvalState & state, bool strict,
JSONPlaceholder & out, PathSet & context) const
{
throw TypeError("cannot convert %1% to JSON", showType());
state.debugThrowLastTrace(TypeError("cannot convert %1% to JSON", showType()));
}

9
src/libutil/error.hh
View file

@ -98,6 +98,15 @@ struct ErrPos {
}
};
std::optional<LinesOfCode> getCodeLines(const ErrPos & errPos);
void printCodeLines(std::ostream & out,
const std::string & prefix,
const ErrPos & errPos,
const LinesOfCode & loc);
void printAtPos(const ErrPos & pos, std::ostream & out);
struct Trace {
std::optional<ErrPos> pos;
hintformat hint;

2
src/libutil/ref.hh
View file

@ -7,7 +7,7 @@
namespace nix {
/* A simple non-nullable reference-counted pointer. Actually a wrapper
around std::shared_ptr that prevents non-null constructions. */
around std::shared_ptr that prevents null constructions. */
template<typename T>
class ref
{