lix/src/libexpr/parser.y

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%glr-parser
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%define api.pure
%locations
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%define parse.error verbose
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%defines
/* %no-lines */
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%parse-param { void * scanner }
%parse-param { nix::ParseData * data }
%lex-param { void * scanner }
%lex-param { nix::ParseData * data }
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%expect 1
%expect-rr 1
%code requires {
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#ifndef BISON_HEADER
#define BISON_HEADER
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#include <variant>
#include "util.hh"
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#include "nixexpr.hh"
#include "eval.hh"
#include "globals.hh"
namespace nix {
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struct ParseData
{
EvalState & state;
SymbolTable & symbols;
Expr * result;
Path basePath;
PosTable::Origin origin;
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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std::optional<ErrorInfo> error;
};
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defer formals duplicate check for incresed efficiency all round if we defer the duplicate argument check for lambda formals we can use more efficient data structures for the formals set, and we can get rid of the duplication of formals names to boot. instead of a list of formals we've seen and a set of names we'll keep a vector instead and run a sort+dupcheck step before moving the parsed formals into a newly created lambda. this improves performance on search and rebuild by ~1%, pure parsing gains more (about 4%). this does reorder lambda arguments in the xml output, but the output is still stable. this shouldn't be a problem since argument order is not semantically important anyway. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.550 s ± 0.060 s [User: 6.470 s, System: 1.664 s] Range (min … max): 8.435 s … 8.666 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 346.7 ms ± 2.1 ms [User: 312.4 ms, System: 34.2 ms] Range (min … max): 343.8 ms … 353.4 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.720 s ± 0.031 s [User: 2.415 s, System: 0.231 s] Range (min … max): 2.662 s … 2.780 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.462 s ± 0.063 s [User: 6.398 s, System: 1.661 s] Range (min … max): 8.339 s … 8.542 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 329.1 ms ± 1.4 ms [User: 296.8 ms, System: 32.3 ms] Range (min … max): 326.1 ms … 330.8 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.687 s ± 0.035 s [User: 2.392 s, System: 0.228 s] Range (min … max): 2.626 s … 2.754 s 20 runs
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struct ParserFormals {
std::vector<Formal> formals;
bool ellipsis = false;
};
}
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// using C a struct allows us to avoid having to define the special
// members that using string_view here would implicitly delete.
struct StringToken {
const char * p;
size_t l;
bool hasIndentation;
operator std::string_view() const { return {p, l}; }
};
#define YY_DECL int yylex \
(YYSTYPE * yylval_param, YYLTYPE * yylloc_param, yyscan_t yyscanner, nix::ParseData * data)
#endif
}
%{
#include "parser-tab.hh"
#include "lexer-tab.hh"
YY_DECL;
using namespace nix;
namespace nix {
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static void dupAttr(const EvalState & state, const AttrPath & attrPath, const PosIdx pos, const PosIdx prevPos)
{
throw ParseError({
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("attribute '%1%' already defined at %2%",
showAttrPath(state.symbols, attrPath), state.positions[prevPos]),
.errPos = state.positions[pos]
});
}
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static void dupAttr(const EvalState & state, Symbol attr, const PosIdx pos, const PosIdx prevPos)
{
throw ParseError({
.msg = hintfmt("attribute '%1%' already defined at %2%", state.symbols[attr], state.positions[prevPos]),
.errPos = state.positions[pos]
});
}
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static void addAttr(ExprAttrs * attrs, AttrPath & attrPath,
Expr * e, const PosIdx pos, const nix::EvalState & state)
{
AttrPath::iterator i;
// All attrpaths have at least one attr
assert(!attrPath.empty());
// Checking attrPath validity.
// ===========================
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for (i = attrPath.begin(); i + 1 < attrPath.end(); i++) {
if (i->symbol) {
ExprAttrs::AttrDefs::iterator j = attrs->attrs.find(i->symbol);
if (j != attrs->attrs.end()) {
if (!j->second.inherited) {
ExprAttrs * attrs2 = dynamic_cast<ExprAttrs *>(j->second.e);
if (!attrs2) dupAttr(state, attrPath, pos, j->second.pos);
attrs = attrs2;
} else
dupAttr(state, attrPath, pos, j->second.pos);
} else {
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ExprAttrs * nested = new ExprAttrs;
attrs->attrs[i->symbol] = ExprAttrs::AttrDef(nested, pos);
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attrs = nested;
}
} else {
ExprAttrs *nested = new ExprAttrs;
attrs->dynamicAttrs.push_back(ExprAttrs::DynamicAttrDef(i->expr, nested, pos));
attrs = nested;
}
}
// Expr insertion.
// ==========================
if (i->symbol) {
ExprAttrs::AttrDefs::iterator j = attrs->attrs.find(i->symbol);
if (j != attrs->attrs.end()) {
// This attr path is already defined. However, if both
// e and the expr pointed by the attr path are two attribute sets,
// we want to merge them.
// Otherwise, throw an error.
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auto ae = dynamic_cast<ExprAttrs *>(e);
auto jAttrs = dynamic_cast<ExprAttrs *>(j->second.e);
if (jAttrs && ae) {
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for (auto & ad : ae->attrs) {
auto j2 = jAttrs->attrs.find(ad.first);
if (j2 != jAttrs->attrs.end()) // Attr already defined in iAttrs, error.
dupAttr(state, ad.first, j2->second.pos, ad.second.pos);
jAttrs->attrs.emplace(ad.first, ad.second);
}
} else {
dupAttr(state, attrPath, pos, j->second.pos);
}
} else {
// This attr path is not defined. Let's create it.
attrs->attrs.emplace(i->symbol, ExprAttrs::AttrDef(e, pos));
e->setName(i->symbol);
}
} else {
attrs->dynamicAttrs.push_back(ExprAttrs::DynamicAttrDef(i->expr, e, pos));
}
}
defer formals duplicate check for incresed efficiency all round if we defer the duplicate argument check for lambda formals we can use more efficient data structures for the formals set, and we can get rid of the duplication of formals names to boot. instead of a list of formals we've seen and a set of names we'll keep a vector instead and run a sort+dupcheck step before moving the parsed formals into a newly created lambda. this improves performance on search and rebuild by ~1%, pure parsing gains more (about 4%). this does reorder lambda arguments in the xml output, but the output is still stable. this shouldn't be a problem since argument order is not semantically important anyway. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.550 s ± 0.060 s [User: 6.470 s, System: 1.664 s] Range (min … max): 8.435 s … 8.666 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 346.7 ms ± 2.1 ms [User: 312.4 ms, System: 34.2 ms] Range (min … max): 343.8 ms … 353.4 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.720 s ± 0.031 s [User: 2.415 s, System: 0.231 s] Range (min … max): 2.662 s … 2.780 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.462 s ± 0.063 s [User: 6.398 s, System: 1.661 s] Range (min … max): 8.339 s … 8.542 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 329.1 ms ± 1.4 ms [User: 296.8 ms, System: 32.3 ms] Range (min … max): 326.1 ms … 330.8 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.687 s ± 0.035 s [User: 2.392 s, System: 0.228 s] Range (min … max): 2.626 s … 2.754 s 20 runs
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static Formals * toFormals(ParseData & data, ParserFormals * formals,
PosIdx pos = noPos, Symbol arg = {})
{
defer formals duplicate check for incresed efficiency all round if we defer the duplicate argument check for lambda formals we can use more efficient data structures for the formals set, and we can get rid of the duplication of formals names to boot. instead of a list of formals we've seen and a set of names we'll keep a vector instead and run a sort+dupcheck step before moving the parsed formals into a newly created lambda. this improves performance on search and rebuild by ~1%, pure parsing gains more (about 4%). this does reorder lambda arguments in the xml output, but the output is still stable. this shouldn't be a problem since argument order is not semantically important anyway. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.550 s ± 0.060 s [User: 6.470 s, System: 1.664 s] Range (min … max): 8.435 s … 8.666 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 346.7 ms ± 2.1 ms [User: 312.4 ms, System: 34.2 ms] Range (min … max): 343.8 ms … 353.4 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.720 s ± 0.031 s [User: 2.415 s, System: 0.231 s] Range (min … max): 2.662 s … 2.780 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.462 s ± 0.063 s [User: 6.398 s, System: 1.661 s] Range (min … max): 8.339 s … 8.542 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 329.1 ms ± 1.4 ms [User: 296.8 ms, System: 32.3 ms] Range (min … max): 326.1 ms … 330.8 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.687 s ± 0.035 s [User: 2.392 s, System: 0.228 s] Range (min … max): 2.626 s … 2.754 s 20 runs
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std::sort(formals->formals.begin(), formals->formals.end(),
[] (const auto & a, const auto & b) {
return std::tie(a.name, a.pos) < std::tie(b.name, b.pos);
});
std::optional<std::pair<Symbol, PosIdx>> duplicate;
defer formals duplicate check for incresed efficiency all round if we defer the duplicate argument check for lambda formals we can use more efficient data structures for the formals set, and we can get rid of the duplication of formals names to boot. instead of a list of formals we've seen and a set of names we'll keep a vector instead and run a sort+dupcheck step before moving the parsed formals into a newly created lambda. this improves performance on search and rebuild by ~1%, pure parsing gains more (about 4%). this does reorder lambda arguments in the xml output, but the output is still stable. this shouldn't be a problem since argument order is not semantically important anyway. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.550 s ± 0.060 s [User: 6.470 s, System: 1.664 s] Range (min … max): 8.435 s … 8.666 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 346.7 ms ± 2.1 ms [User: 312.4 ms, System: 34.2 ms] Range (min … max): 343.8 ms … 353.4 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.720 s ± 0.031 s [User: 2.415 s, System: 0.231 s] Range (min … max): 2.662 s … 2.780 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.462 s ± 0.063 s [User: 6.398 s, System: 1.661 s] Range (min … max): 8.339 s … 8.542 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 329.1 ms ± 1.4 ms [User: 296.8 ms, System: 32.3 ms] Range (min … max): 326.1 ms … 330.8 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.687 s ± 0.035 s [User: 2.392 s, System: 0.228 s] Range (min … max): 2.626 s … 2.754 s 20 runs
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for (size_t i = 0; i + 1 < formals->formals.size(); i++) {
if (formals->formals[i].name != formals->formals[i + 1].name)
continue;
std::pair thisDup{formals->formals[i].name, formals->formals[i + 1].pos};
duplicate = std::min(thisDup, duplicate.value_or(thisDup));
}
if (duplicate)
throw ParseError({
.msg = hintfmt("duplicate formal function argument '%1%'", data.symbols[duplicate->first]),
.errPos = data.state.positions[duplicate->second]
defer formals duplicate check for incresed efficiency all round if we defer the duplicate argument check for lambda formals we can use more efficient data structures for the formals set, and we can get rid of the duplication of formals names to boot. instead of a list of formals we've seen and a set of names we'll keep a vector instead and run a sort+dupcheck step before moving the parsed formals into a newly created lambda. this improves performance on search and rebuild by ~1%, pure parsing gains more (about 4%). this does reorder lambda arguments in the xml output, but the output is still stable. this shouldn't be a problem since argument order is not semantically important anyway. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.550 s ± 0.060 s [User: 6.470 s, System: 1.664 s] Range (min … max): 8.435 s … 8.666 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 346.7 ms ± 2.1 ms [User: 312.4 ms, System: 34.2 ms] Range (min … max): 343.8 ms … 353.4 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.720 s ± 0.031 s [User: 2.415 s, System: 0.231 s] Range (min … max): 2.662 s … 2.780 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.462 s ± 0.063 s [User: 6.398 s, System: 1.661 s] Range (min … max): 8.339 s … 8.542 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 329.1 ms ± 1.4 ms [User: 296.8 ms, System: 32.3 ms] Range (min … max): 326.1 ms … 330.8 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.687 s ± 0.035 s [User: 2.392 s, System: 0.228 s] Range (min … max): 2.626 s … 2.754 s 20 runs
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});
Formals result;
result.ellipsis = formals->ellipsis;
result.formals = std::move(formals->formals);
if (arg && result.has(arg))
throw ParseError({
.msg = hintfmt("duplicate formal function argument '%1%'", data.symbols[arg]),
.errPos = data.state.positions[pos]
});
defer formals duplicate check for incresed efficiency all round if we defer the duplicate argument check for lambda formals we can use more efficient data structures for the formals set, and we can get rid of the duplication of formals names to boot. instead of a list of formals we've seen and a set of names we'll keep a vector instead and run a sort+dupcheck step before moving the parsed formals into a newly created lambda. this improves performance on search and rebuild by ~1%, pure parsing gains more (about 4%). this does reorder lambda arguments in the xml output, but the output is still stable. this shouldn't be a problem since argument order is not semantically important anyway. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.550 s ± 0.060 s [User: 6.470 s, System: 1.664 s] Range (min … max): 8.435 s … 8.666 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 346.7 ms ± 2.1 ms [User: 312.4 ms, System: 34.2 ms] Range (min … max): 343.8 ms … 353.4 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.720 s ± 0.031 s [User: 2.415 s, System: 0.231 s] Range (min … max): 2.662 s … 2.780 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.462 s ± 0.063 s [User: 6.398 s, System: 1.661 s] Range (min … max): 8.339 s … 8.542 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 329.1 ms ± 1.4 ms [User: 296.8 ms, System: 32.3 ms] Range (min … max): 326.1 ms … 330.8 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.687 s ± 0.035 s [User: 2.392 s, System: 0.228 s] Range (min … max): 2.626 s … 2.754 s 20 runs
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delete formals;
return new Formals(std::move(result));
}
static Expr * stripIndentation(const PosIdx pos, SymbolTable & symbols,
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std::vector<std::pair<PosIdx, std::variant<Expr *, StringToken>>> & es)
{
don't use Symbols for strings string expressions by and large do not need the benefits a Symbol gives us, instead they pollute the symbol table and cause unnecessary overhead for almost all strings. the one place we can think of that benefits from them (attrpaths with expressions) extracts the benefit in the parser, which we'll have to touch anyway when changing ExprString to hold strings. this gives a sizeable improvement on of 3-5% on all benchmarks we've run. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.844 s ± 0.045 s [User: 6.750 s, System: 1.663 s] Range (min … max): 8.758 s … 8.922 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 367.4 ms ± 3.3 ms [User: 332.3 ms, System: 35.2 ms] Range (min … max): 364.0 ms … 375.2 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.810 s ± 0.030 s [User: 2.517 s, System: 0.225 s] Range (min … max): 2.742 s … 2.854 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.533 s ± 0.068 s [User: 6.485 s, System: 1.642 s] Range (min … max): 8.404 s … 8.657 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 347.6 ms ± 3.1 ms [User: 313.1 ms, System: 34.5 ms] Range (min … max): 343.3 ms … 354.6 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.709 s ± 0.032 s [User: 2.414 s, System: 0.232 s] Range (min … max): 2.655 s … 2.788 s 20 runs
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if (es.empty()) return new ExprString("");
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/* Figure out the minimum indentation. Note that by design
whitespace-only final lines are not taken into account. (So
the " " in "\n ''" is ignored, but the " " in "\n foo''" is.) */
bool atStartOfLine = true; /* = seen only whitespace in the current line */
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size_t minIndent = 1000000;
size_t curIndent = 0;
for (auto & [i_pos, i] : es) {
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auto * str = std::get_if<StringToken>(&i);
if (!str || !str->hasIndentation) {
/* Anti-quotations and escaped characters end the current start-of-line whitespace. */
if (atStartOfLine) {
atStartOfLine = false;
if (curIndent < minIndent) minIndent = curIndent;
}
continue;
}
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for (size_t j = 0; j < str->l; ++j) {
if (atStartOfLine) {
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if (str->p[j] == ' ')
curIndent++;
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else if (str->p[j] == '\n') {
/* Empty line, doesn't influence minimum
indentation. */
curIndent = 0;
} else {
atStartOfLine = false;
if (curIndent < minIndent) minIndent = curIndent;
}
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} else if (str->p[j] == '\n') {
atStartOfLine = true;
curIndent = 0;
}
}
}
/* Strip spaces from each line. */
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auto * es2 = new std::vector<std::pair<PosIdx, Expr *>>;
atStartOfLine = true;
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size_t curDropped = 0;
size_t n = es.size();
2022-01-19 12:39:42 +00:00
auto i = es.begin();
const auto trimExpr = [&] (Expr * e) {
atStartOfLine = false;
curDropped = 0;
es2->emplace_back(i->first, e);
};
const auto trimString = [&] (const StringToken & t) {
std::string s2;
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for (size_t j = 0; j < t.l; ++j) {
if (atStartOfLine) {
2022-01-19 12:39:42 +00:00
if (t.p[j] == ' ') {
if (curDropped++ >= minIndent)
2022-01-19 12:39:42 +00:00
s2 += t.p[j];
}
2022-01-19 12:39:42 +00:00
else if (t.p[j] == '\n') {
curDropped = 0;
2022-01-19 12:39:42 +00:00
s2 += t.p[j];
} else {
atStartOfLine = false;
curDropped = 0;
2022-01-19 12:39:42 +00:00
s2 += t.p[j];
}
} else {
2022-01-19 12:39:42 +00:00
s2 += t.p[j];
if (t.p[j] == '\n') atStartOfLine = true;
}
}
/* Remove the last line if it is empty and consists only of
spaces. */
if (n == 1) {
std::string::size_type p = s2.find_last_of('\n');
if (p != std::string::npos && s2.find_first_not_of(' ', p + 1) == std::string::npos)
s2 = std::string(s2, 0, p + 1);
}
2010-04-12 22:03:27 +00:00
don't use Symbols for strings string expressions by and large do not need the benefits a Symbol gives us, instead they pollute the symbol table and cause unnecessary overhead for almost all strings. the one place we can think of that benefits from them (attrpaths with expressions) extracts the benefit in the parser, which we'll have to touch anyway when changing ExprString to hold strings. this gives a sizeable improvement on of 3-5% on all benchmarks we've run. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.844 s ± 0.045 s [User: 6.750 s, System: 1.663 s] Range (min … max): 8.758 s … 8.922 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 367.4 ms ± 3.3 ms [User: 332.3 ms, System: 35.2 ms] Range (min … max): 364.0 ms … 375.2 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.810 s ± 0.030 s [User: 2.517 s, System: 0.225 s] Range (min … max): 2.742 s … 2.854 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.533 s ± 0.068 s [User: 6.485 s, System: 1.642 s] Range (min … max): 8.404 s … 8.657 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 347.6 ms ± 3.1 ms [User: 313.1 ms, System: 34.5 ms] Range (min … max): 343.3 ms … 354.6 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.709 s ± 0.032 s [User: 2.414 s, System: 0.232 s] Range (min … max): 2.655 s … 2.788 s 20 runs
2022-01-19 13:31:30 +00:00
es2->emplace_back(i->first, new ExprString(s2));
2022-01-19 12:39:42 +00:00
};
for (; i != es.end(); ++i, --n) {
std::visit(overloaded { trimExpr, trimString }, i->second);
}
/* If this is a single string, then don't do a concatenation. */
return es2->size() == 1 && dynamic_cast<ExprString *>((*es2)[0].second) ? (*es2)[0].second : new ExprConcatStrings(pos, true, es2);
}
static inline PosIdx makeCurPos(const YYLTYPE & loc, ParseData * data)
{
return data->state.positions.add(data->origin, loc.first_line, loc.first_column);
}
#define CUR_POS makeCurPos(*yylocp, data)
}
2006-10-02 14:43:15 +00:00
void yyerror(YYLTYPE * loc, yyscan_t scanner, ParseData * data, const char * error)
{
data->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(error),
.errPos = data->state.positions[makeCurPos(*loc, data)]
};
}
%}
%union {
2013-09-02 14:29:15 +00:00
// !!! We're probably leaking stuff here.
nix::Expr * e;
nix::ExprList * list;
nix::ExprAttrs * attrs;
defer formals duplicate check for incresed efficiency all round if we defer the duplicate argument check for lambda formals we can use more efficient data structures for the formals set, and we can get rid of the duplication of formals names to boot. instead of a list of formals we've seen and a set of names we'll keep a vector instead and run a sort+dupcheck step before moving the parsed formals into a newly created lambda. this improves performance on search and rebuild by ~1%, pure parsing gains more (about 4%). this does reorder lambda arguments in the xml output, but the output is still stable. this shouldn't be a problem since argument order is not semantically important anyway. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.550 s ± 0.060 s [User: 6.470 s, System: 1.664 s] Range (min … max): 8.435 s … 8.666 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 346.7 ms ± 2.1 ms [User: 312.4 ms, System: 34.2 ms] Range (min … max): 343.8 ms … 353.4 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.720 s ± 0.031 s [User: 2.415 s, System: 0.231 s] Range (min … max): 2.662 s … 2.780 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.462 s ± 0.063 s [User: 6.398 s, System: 1.661 s] Range (min … max): 8.339 s … 8.542 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 329.1 ms ± 1.4 ms [User: 296.8 ms, System: 32.3 ms] Range (min … max): 326.1 ms … 330.8 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.687 s ± 0.035 s [User: 2.392 s, System: 0.228 s] Range (min … max): 2.626 s … 2.754 s 20 runs
2022-01-19 15:49:02 +00:00
nix::ParserFormals * formals;
nix::Formal * formal;
nix::NixInt n;
nix::NixFloat nf;
StringToken id; // !!! -> Symbol
StringToken path;
StringToken uri;
2022-01-19 12:39:42 +00:00
StringToken str;
std::vector<nix::AttrName> * attrNames;
2022-05-25 13:49:41 +00:00
std::vector<std::pair<nix::PosIdx, nix::Expr *>> * string_parts;
std::vector<std::pair<nix::PosIdx, std::variant<nix::Expr *, StringToken>>> * ind_string_parts;
}
%type <e> start expr expr_function expr_if expr_op
%type <e> expr_select expr_simple expr_app
%type <list> expr_list
%type <attrs> binds
%type <formals> formals
%type <formal> formal
%type <attrNames> attrs attrpath
2022-01-19 12:39:42 +00:00
%type <string_parts> string_parts_interpolated
%type <ind_string_parts> ind_string_parts
2021-07-29 16:03:07 +00:00
%type <e> path_start string_parts string_attr
%type <id> attr
%token <id> ID ATTRPATH
2022-01-19 12:39:42 +00:00
%token <str> STR IND_STR
%token <n> INT
%token <nf> FLOAT
2021-07-29 16:03:07 +00:00
%token <path> PATH HPATH SPATH PATH_END
%token <uri> URI
%token IF THEN ELSE ASSERT WITH LET IN REC INHERIT EQ NEQ AND OR IMPL OR_KW
%token DOLLAR_CURLY /* == ${ */
%token IND_STRING_OPEN IND_STRING_CLOSE
%token ELLIPSIS
2018-07-23 07:28:48 +00:00
%right IMPL
%left OR
%left AND
%nonassoc EQ NEQ
%nonassoc '<' '>' LEQ GEQ
%right UPDATE
%left NOT
%left '+' '-'
%left '*' '/'
%right CONCAT
%nonassoc '?'
%nonassoc NEGATE
%%
start: expr { data->result = $1; };
expr: expr_function;
expr_function
: ID ':' expr_function
{ $$ = new ExprLambda(CUR_POS, data->symbols.create($1), 0, $3); }
| '{' formals '}' ':' expr_function
{ $$ = new ExprLambda(CUR_POS, toFormals(*data, $2), $5); }
| '{' formals '}' '@' ID ':' expr_function
defer formals duplicate check for incresed efficiency all round if we defer the duplicate argument check for lambda formals we can use more efficient data structures for the formals set, and we can get rid of the duplication of formals names to boot. instead of a list of formals we've seen and a set of names we'll keep a vector instead and run a sort+dupcheck step before moving the parsed formals into a newly created lambda. this improves performance on search and rebuild by ~1%, pure parsing gains more (about 4%). this does reorder lambda arguments in the xml output, but the output is still stable. this shouldn't be a problem since argument order is not semantically important anyway. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.550 s ± 0.060 s [User: 6.470 s, System: 1.664 s] Range (min … max): 8.435 s … 8.666 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 346.7 ms ± 2.1 ms [User: 312.4 ms, System: 34.2 ms] Range (min … max): 343.8 ms … 353.4 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.720 s ± 0.031 s [User: 2.415 s, System: 0.231 s] Range (min … max): 2.662 s … 2.780 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.462 s ± 0.063 s [User: 6.398 s, System: 1.661 s] Range (min … max): 8.339 s … 8.542 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 329.1 ms ± 1.4 ms [User: 296.8 ms, System: 32.3 ms] Range (min … max): 326.1 ms … 330.8 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.687 s ± 0.035 s [User: 2.392 s, System: 0.228 s] Range (min … max): 2.626 s … 2.754 s 20 runs
2022-01-19 15:49:02 +00:00
{
auto arg = data->symbols.create($5);
defer formals duplicate check for incresed efficiency all round if we defer the duplicate argument check for lambda formals we can use more efficient data structures for the formals set, and we can get rid of the duplication of formals names to boot. instead of a list of formals we've seen and a set of names we'll keep a vector instead and run a sort+dupcheck step before moving the parsed formals into a newly created lambda. this improves performance on search and rebuild by ~1%, pure parsing gains more (about 4%). this does reorder lambda arguments in the xml output, but the output is still stable. this shouldn't be a problem since argument order is not semantically important anyway. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.550 s ± 0.060 s [User: 6.470 s, System: 1.664 s] Range (min … max): 8.435 s … 8.666 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 346.7 ms ± 2.1 ms [User: 312.4 ms, System: 34.2 ms] Range (min … max): 343.8 ms … 353.4 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.720 s ± 0.031 s [User: 2.415 s, System: 0.231 s] Range (min … max): 2.662 s … 2.780 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.462 s ± 0.063 s [User: 6.398 s, System: 1.661 s] Range (min … max): 8.339 s … 8.542 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 329.1 ms ± 1.4 ms [User: 296.8 ms, System: 32.3 ms] Range (min … max): 326.1 ms … 330.8 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.687 s ± 0.035 s [User: 2.392 s, System: 0.228 s] Range (min … max): 2.626 s … 2.754 s 20 runs
2022-01-19 15:49:02 +00:00
$$ = new ExprLambda(CUR_POS, arg, toFormals(*data, $2, CUR_POS, arg), $7);
}
| ID '@' '{' formals '}' ':' expr_function
defer formals duplicate check for incresed efficiency all round if we defer the duplicate argument check for lambda formals we can use more efficient data structures for the formals set, and we can get rid of the duplication of formals names to boot. instead of a list of formals we've seen and a set of names we'll keep a vector instead and run a sort+dupcheck step before moving the parsed formals into a newly created lambda. this improves performance on search and rebuild by ~1%, pure parsing gains more (about 4%). this does reorder lambda arguments in the xml output, but the output is still stable. this shouldn't be a problem since argument order is not semantically important anyway. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.550 s ± 0.060 s [User: 6.470 s, System: 1.664 s] Range (min … max): 8.435 s … 8.666 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 346.7 ms ± 2.1 ms [User: 312.4 ms, System: 34.2 ms] Range (min … max): 343.8 ms … 353.4 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.720 s ± 0.031 s [User: 2.415 s, System: 0.231 s] Range (min … max): 2.662 s … 2.780 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.462 s ± 0.063 s [User: 6.398 s, System: 1.661 s] Range (min … max): 8.339 s … 8.542 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 329.1 ms ± 1.4 ms [User: 296.8 ms, System: 32.3 ms] Range (min … max): 326.1 ms … 330.8 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.687 s ± 0.035 s [User: 2.392 s, System: 0.228 s] Range (min … max): 2.626 s … 2.754 s 20 runs
2022-01-19 15:49:02 +00:00
{
auto arg = data->symbols.create($1);
defer formals duplicate check for incresed efficiency all round if we defer the duplicate argument check for lambda formals we can use more efficient data structures for the formals set, and we can get rid of the duplication of formals names to boot. instead of a list of formals we've seen and a set of names we'll keep a vector instead and run a sort+dupcheck step before moving the parsed formals into a newly created lambda. this improves performance on search and rebuild by ~1%, pure parsing gains more (about 4%). this does reorder lambda arguments in the xml output, but the output is still stable. this shouldn't be a problem since argument order is not semantically important anyway. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.550 s ± 0.060 s [User: 6.470 s, System: 1.664 s] Range (min … max): 8.435 s … 8.666 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 346.7 ms ± 2.1 ms [User: 312.4 ms, System: 34.2 ms] Range (min … max): 343.8 ms … 353.4 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.720 s ± 0.031 s [User: 2.415 s, System: 0.231 s] Range (min … max): 2.662 s … 2.780 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.462 s ± 0.063 s [User: 6.398 s, System: 1.661 s] Range (min … max): 8.339 s … 8.542 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 329.1 ms ± 1.4 ms [User: 296.8 ms, System: 32.3 ms] Range (min … max): 326.1 ms … 330.8 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.687 s ± 0.035 s [User: 2.392 s, System: 0.228 s] Range (min … max): 2.626 s … 2.754 s 20 runs
2022-01-19 15:49:02 +00:00
$$ = new ExprLambda(CUR_POS, arg, toFormals(*data, $4, CUR_POS, arg), $7);
}
2010-04-12 21:21:24 +00:00
| ASSERT expr ';' expr_function
{ $$ = new ExprAssert(CUR_POS, $2, $4); }
| WITH expr ';' expr_function
{ $$ = new ExprWith(CUR_POS, $2, $4); }
| LET binds IN expr_function
Dynamic attrs This adds new syntax for attribute names: * attrs."${name}" => getAttr name attrs * attrs ? "${name}" => isAttrs attrs && hasAttr attrs name * attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def * { "${name}" = value; } => listToAttrs [{ inherit name value; }] Of course, it's a bit more complicated than that. The attribute chains can be arbitrarily long and contain combinations of static and dynamic parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively straightforward for the getAttrs/hasAttrs cases but is more complex for the listToAttrs case due to rules about duplicate attribute definitions. For attribute sets with dynamic attribute names, duplicate static attributes are detected at parse time while duplicate dynamic attributes are detected when the attribute set is forced. So, for example, { a = null; a.b = null; "${"c"}" = true; } will be a parse-time error, while { a = {}; "${"a"}".b = null; c = true; } will be an eval-time error (technically that case could theoretically be detected at parse time, but the general case would require full evaluation). Moreover, duplicate dynamic attributes are not allowed even in cases where they would be with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but { a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction might be relaxed in the future in cases where the static variant would not be an error, but it is not obvious that that is desirable. Finally, recursive attribute sets with dynamic attributes have the static attributes in scope but not the dynamic ones. So rec { a = true; "${"b"}" = a; } is equivalent to { a = true; b = true; } but rec { "${"a"}" = true; b = a; } would be an error or use a from the surrounding scope if it exists. Note that the getAttr, getAttr or default, and hasAttr are all implemented purely in the parser as syntactic sugar, while attribute sets with dynamic attribute names required changes to the AST to be implemented cleanly. This is an alternative solution to and closes #167 Signed-off-by: Shea Levy <shea@shealevy.com>
2013-09-21 03:25:30 +00:00
{ if (!$2->dynamicAttrs.empty())
throw ParseError({
Improve error formatting Changes: * The divider lines are gone. These were in practice a bit confusing, in particular with --show-trace or --keep-going, since then there were multiple lines, suggesting a start/end which wasn't the case. * Instead, multi-line error messages are now indented to align with the prefix (e.g. "error: "). * The 'description' field is gone since we weren't really using it. * 'hint' is renamed to 'msg' since it really wasn't a hint. * The error is now printed *before* the location info. * The 'name' field is no longer printed since most of the time it wasn't very useful since it was just the name of the exception (like EvalError). Ideally in the future this would be a unique, easily googleable error ID (like rustc). * "trace:" is now just "…". This assumes error contexts start with something like "while doing X". Example before: error: --- AssertionError ---------------------------------------------------------------------------------------- nix at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix 6| 7| x = assert false; 1; | ^ 8| assertion 'false' failed ----------------------------------------------------- show-trace ----------------------------------------------------- trace: while evaluating the attribute 'x' of the derivation 'hello-2.10' at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix 191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) { 192| name = "${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}-${attrs.version}"; | ^ 193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
2021-01-20 23:27:36 +00:00
.msg = hintfmt("dynamic attributes not allowed in let"),
.errPos = data->state.positions[CUR_POS]
});
Dynamic attrs This adds new syntax for attribute names: * attrs."${name}" => getAttr name attrs * attrs ? "${name}" => isAttrs attrs && hasAttr attrs name * attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def * { "${name}" = value; } => listToAttrs [{ inherit name value; }] Of course, it's a bit more complicated than that. The attribute chains can be arbitrarily long and contain combinations of static and dynamic parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively straightforward for the getAttrs/hasAttrs cases but is more complex for the listToAttrs case due to rules about duplicate attribute definitions. For attribute sets with dynamic attribute names, duplicate static attributes are detected at parse time while duplicate dynamic attributes are detected when the attribute set is forced. So, for example, { a = null; a.b = null; "${"c"}" = true; } will be a parse-time error, while { a = {}; "${"a"}".b = null; c = true; } will be an eval-time error (technically that case could theoretically be detected at parse time, but the general case would require full evaluation). Moreover, duplicate dynamic attributes are not allowed even in cases where they would be with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but { a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction might be relaxed in the future in cases where the static variant would not be an error, but it is not obvious that that is desirable. Finally, recursive attribute sets with dynamic attributes have the static attributes in scope but not the dynamic ones. So rec { a = true; "${"b"}" = a; } is equivalent to { a = true; b = true; } but rec { "${"a"}" = true; b = a; } would be an error or use a from the surrounding scope if it exists. Note that the getAttr, getAttr or default, and hasAttr are all implemented purely in the parser as syntactic sugar, while attribute sets with dynamic attribute names required changes to the AST to be implemented cleanly. This is an alternative solution to and closes #167 Signed-off-by: Shea Levy <shea@shealevy.com>
2013-09-21 03:25:30 +00:00
$$ = new ExprLet($2, $4);
}
| expr_if
;
expr_if
2022-10-20 11:55:15 +00:00
: IF expr THEN expr ELSE expr { $$ = new ExprIf(CUR_POS, $2, $4, $6); }
| expr_op
;
expr_op
: '!' expr_op %prec NOT { $$ = new ExprOpNot($2); }
| '-' expr_op %prec NEGATE { $$ = new ExprCall(CUR_POS, new ExprVar(data->symbols.create("__sub")), {new ExprInt(0), $2}); }
2010-04-12 21:21:24 +00:00
| expr_op EQ expr_op { $$ = new ExprOpEq($1, $3); }
| expr_op NEQ expr_op { $$ = new ExprOpNEq($1, $3); }
| expr_op '<' expr_op { $$ = new ExprCall(makeCurPos(@2, data), new ExprVar(data->symbols.create("__lessThan")), {$1, $3}); }
| expr_op LEQ expr_op { $$ = new ExprOpNot(new ExprCall(makeCurPos(@2, data), new ExprVar(data->symbols.create("__lessThan")), {$3, $1})); }
| expr_op '>' expr_op { $$ = new ExprCall(makeCurPos(@2, data), new ExprVar(data->symbols.create("__lessThan")), {$3, $1}); }
| expr_op GEQ expr_op { $$ = new ExprOpNot(new ExprCall(makeCurPos(@2, data), new ExprVar(data->symbols.create("__lessThan")), {$1, $3})); }
| expr_op AND expr_op { $$ = new ExprOpAnd(makeCurPos(@2, data), $1, $3); }
| expr_op OR expr_op { $$ = new ExprOpOr(makeCurPos(@2, data), $1, $3); }
| expr_op IMPL expr_op { $$ = new ExprOpImpl(makeCurPos(@2, data), $1, $3); }
| expr_op UPDATE expr_op { $$ = new ExprOpUpdate(makeCurPos(@2, data), $1, $3); }
| expr_op '?' attrpath { $$ = new ExprOpHasAttr($1, *$3); }
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| expr_op '+' expr_op
{ $$ = new ExprConcatStrings(makeCurPos(@2, data), false, new std::vector<std::pair<PosIdx, Expr *> >({{makeCurPos(@1, data), $1}, {makeCurPos(@3, data), $3}})); }
| expr_op '-' expr_op { $$ = new ExprCall(makeCurPos(@2, data), new ExprVar(data->symbols.create("__sub")), {$1, $3}); }
| expr_op '*' expr_op { $$ = new ExprCall(makeCurPos(@2, data), new ExprVar(data->symbols.create("__mul")), {$1, $3}); }
| expr_op '/' expr_op { $$ = new ExprCall(makeCurPos(@2, data), new ExprVar(data->symbols.create("__div")), {$1, $3}); }
| expr_op CONCAT expr_op { $$ = new ExprOpConcatLists(makeCurPos(@2, data), $1, $3); }
| expr_app
;
expr_app
: expr_app expr_select {
if (auto e2 = dynamic_cast<ExprCall *>($1)) {
e2->args.push_back($2);
$$ = $1;
} else
$$ = new ExprCall(CUR_POS, $1, {$2});
}
| expr_select
;
expr_select
: expr_simple '.' attrpath
{ $$ = new ExprSelect(CUR_POS, $1, *$3, 0); }
| expr_simple '.' attrpath OR_KW expr_select
{ $$ = new ExprSelect(CUR_POS, $1, *$3, $5); }
| /* Backwards compatibility: because Nixpkgs has a rarely used
function named or, allow stuff like map or [...]. */
expr_simple OR_KW
{ $$ = new ExprCall(CUR_POS, $1, {new ExprVar(CUR_POS, data->symbols.create("or"))}); }
| expr_simple { $$ = $1; }
;
expr_simple
: ID {
std::string_view s = "__curPos";
if ($1.l == s.size() && strncmp($1.p, s.data(), s.size()) == 0)
$$ = new ExprPos(CUR_POS);
else
$$ = new ExprVar(CUR_POS, data->symbols.create($1));
}
2010-04-12 21:21:24 +00:00
| INT { $$ = new ExprInt($1); }
| FLOAT { $$ = new ExprFloat($1); }
Dynamic attrs This adds new syntax for attribute names: * attrs."${name}" => getAttr name attrs * attrs ? "${name}" => isAttrs attrs && hasAttr attrs name * attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def * { "${name}" = value; } => listToAttrs [{ inherit name value; }] Of course, it's a bit more complicated than that. The attribute chains can be arbitrarily long and contain combinations of static and dynamic parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively straightforward for the getAttrs/hasAttrs cases but is more complex for the listToAttrs case due to rules about duplicate attribute definitions. For attribute sets with dynamic attribute names, duplicate static attributes are detected at parse time while duplicate dynamic attributes are detected when the attribute set is forced. So, for example, { a = null; a.b = null; "${"c"}" = true; } will be a parse-time error, while { a = {}; "${"a"}".b = null; c = true; } will be an eval-time error (technically that case could theoretically be detected at parse time, but the general case would require full evaluation). Moreover, duplicate dynamic attributes are not allowed even in cases where they would be with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but { a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction might be relaxed in the future in cases where the static variant would not be an error, but it is not obvious that that is desirable. Finally, recursive attribute sets with dynamic attributes have the static attributes in scope but not the dynamic ones. So rec { a = true; "${"b"}" = a; } is equivalent to { a = true; b = true; } but rec { "${"a"}" = true; b = a; } would be an error or use a from the surrounding scope if it exists. Note that the getAttr, getAttr or default, and hasAttr are all implemented purely in the parser as syntactic sugar, while attribute sets with dynamic attribute names required changes to the AST to be implemented cleanly. This is an alternative solution to and closes #167 Signed-off-by: Shea Levy <shea@shealevy.com>
2013-09-21 03:25:30 +00:00
| '"' string_parts '"' { $$ = $2; }
| IND_STRING_OPEN ind_string_parts IND_STRING_CLOSE {
$$ = stripIndentation(CUR_POS, data->symbols, *$2);
}
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| path_start PATH_END { $$ = $1; }
| path_start string_parts_interpolated PATH_END {
$2->insert($2->begin(), {makeCurPos(@1, data), $1});
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$$ = new ExprConcatStrings(CUR_POS, false, $2);
}
| SPATH {
std::string path($1.p + 1, $1.l - 2);
$$ = new ExprCall(CUR_POS,
new ExprVar(data->symbols.create("__findFile")),
{new ExprVar(data->symbols.create("__nixPath")),
don't use Symbols for strings string expressions by and large do not need the benefits a Symbol gives us, instead they pollute the symbol table and cause unnecessary overhead for almost all strings. the one place we can think of that benefits from them (attrpaths with expressions) extracts the benefit in the parser, which we'll have to touch anyway when changing ExprString to hold strings. this gives a sizeable improvement on of 3-5% on all benchmarks we've run. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.844 s ± 0.045 s [User: 6.750 s, System: 1.663 s] Range (min … max): 8.758 s … 8.922 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 367.4 ms ± 3.3 ms [User: 332.3 ms, System: 35.2 ms] Range (min … max): 364.0 ms … 375.2 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.810 s ± 0.030 s [User: 2.517 s, System: 0.225 s] Range (min … max): 2.742 s … 2.854 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.533 s ± 0.068 s [User: 6.485 s, System: 1.642 s] Range (min … max): 8.404 s … 8.657 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 347.6 ms ± 3.1 ms [User: 313.1 ms, System: 34.5 ms] Range (min … max): 343.3 ms … 354.6 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.709 s ± 0.032 s [User: 2.414 s, System: 0.232 s] Range (min … max): 2.655 s … 2.788 s 20 runs
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new ExprString(path)});
}
| URI {
static bool noURLLiterals = settings.isExperimentalFeatureEnabled(Xp::NoUrlLiterals);
if (noURLLiterals)
throw ParseError({
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("URL literals are disabled"),
.errPos = data->state.positions[CUR_POS]
});
$$ = new ExprString(std::string($1));
}
| '(' expr ')' { $$ = $2; }
/* Let expressions `let {..., body = ...}' are just desugared
2010-04-12 21:21:24 +00:00
into `(rec {..., body = ...}).body'. */
| LET '{' binds '}'
{ $3->recursive = true; $$ = new ExprSelect(noPos, $3, data->symbols.create("body")); }
| REC '{' binds '}'
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{ $3->recursive = true; $$ = $3; }
| '{' binds '}'
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{ $$ = $2; }
| '[' expr_list ']' { $$ = $2; }
;
string_parts
: STR { $$ = new ExprString(std::string($1)); }
| string_parts_interpolated { $$ = new ExprConcatStrings(CUR_POS, true, $1); }
don't use Symbols for strings string expressions by and large do not need the benefits a Symbol gives us, instead they pollute the symbol table and cause unnecessary overhead for almost all strings. the one place we can think of that benefits from them (attrpaths with expressions) extracts the benefit in the parser, which we'll have to touch anyway when changing ExprString to hold strings. this gives a sizeable improvement on of 3-5% on all benchmarks we've run. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.844 s ± 0.045 s [User: 6.750 s, System: 1.663 s] Range (min … max): 8.758 s … 8.922 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 367.4 ms ± 3.3 ms [User: 332.3 ms, System: 35.2 ms] Range (min … max): 364.0 ms … 375.2 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.810 s ± 0.030 s [User: 2.517 s, System: 0.225 s] Range (min … max): 2.742 s … 2.854 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.533 s ± 0.068 s [User: 6.485 s, System: 1.642 s] Range (min … max): 8.404 s … 8.657 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 347.6 ms ± 3.1 ms [User: 313.1 ms, System: 34.5 ms] Range (min … max): 343.3 ms … 354.6 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.709 s ± 0.032 s [User: 2.414 s, System: 0.232 s] Range (min … max): 2.655 s … 2.788 s 20 runs
2022-01-19 13:31:30 +00:00
| { $$ = new ExprString(""); }
Dynamic attrs This adds new syntax for attribute names: * attrs."${name}" => getAttr name attrs * attrs ? "${name}" => isAttrs attrs && hasAttr attrs name * attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def * { "${name}" = value; } => listToAttrs [{ inherit name value; }] Of course, it's a bit more complicated than that. The attribute chains can be arbitrarily long and contain combinations of static and dynamic parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively straightforward for the getAttrs/hasAttrs cases but is more complex for the listToAttrs case due to rules about duplicate attribute definitions. For attribute sets with dynamic attribute names, duplicate static attributes are detected at parse time while duplicate dynamic attributes are detected when the attribute set is forced. So, for example, { a = null; a.b = null; "${"c"}" = true; } will be a parse-time error, while { a = {}; "${"a"}".b = null; c = true; } will be an eval-time error (technically that case could theoretically be detected at parse time, but the general case would require full evaluation). Moreover, duplicate dynamic attributes are not allowed even in cases where they would be with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but { a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction might be relaxed in the future in cases where the static variant would not be an error, but it is not obvious that that is desirable. Finally, recursive attribute sets with dynamic attributes have the static attributes in scope but not the dynamic ones. So rec { a = true; "${"b"}" = a; } is equivalent to { a = true; b = true; } but rec { "${"a"}" = true; b = a; } would be an error or use a from the surrounding scope if it exists. Note that the getAttr, getAttr or default, and hasAttr are all implemented purely in the parser as syntactic sugar, while attribute sets with dynamic attribute names required changes to the AST to be implemented cleanly. This is an alternative solution to and closes #167 Signed-off-by: Shea Levy <shea@shealevy.com>
2013-09-21 03:25:30 +00:00
;
string_parts_interpolated
2022-01-19 12:39:42 +00:00
: string_parts_interpolated STR
{ $$ = $1; $1->emplace_back(makeCurPos(@2, data), new ExprString(std::string($2))); }
| string_parts_interpolated DOLLAR_CURLY expr '}' { $$ = $1; $1->emplace_back(makeCurPos(@2, data), $3); }
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| DOLLAR_CURLY expr '}' { $$ = new std::vector<std::pair<PosIdx, Expr *>>; $$->emplace_back(makeCurPos(@1, data), $2); }
| STR DOLLAR_CURLY expr '}' {
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$$ = new std::vector<std::pair<PosIdx, Expr *>>;
$$->emplace_back(makeCurPos(@1, data), new ExprString(std::string($1)));
$$->emplace_back(makeCurPos(@2, data), $3);
Dynamic attrs This adds new syntax for attribute names: * attrs."${name}" => getAttr name attrs * attrs ? "${name}" => isAttrs attrs && hasAttr attrs name * attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def * { "${name}" = value; } => listToAttrs [{ inherit name value; }] Of course, it's a bit more complicated than that. The attribute chains can be arbitrarily long and contain combinations of static and dynamic parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively straightforward for the getAttrs/hasAttrs cases but is more complex for the listToAttrs case due to rules about duplicate attribute definitions. For attribute sets with dynamic attribute names, duplicate static attributes are detected at parse time while duplicate dynamic attributes are detected when the attribute set is forced. So, for example, { a = null; a.b = null; "${"c"}" = true; } will be a parse-time error, while { a = {}; "${"a"}".b = null; c = true; } will be an eval-time error (technically that case could theoretically be detected at parse time, but the general case would require full evaluation). Moreover, duplicate dynamic attributes are not allowed even in cases where they would be with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but { a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction might be relaxed in the future in cases where the static variant would not be an error, but it is not obvious that that is desirable. Finally, recursive attribute sets with dynamic attributes have the static attributes in scope but not the dynamic ones. So rec { a = true; "${"b"}" = a; } is equivalent to { a = true; b = true; } but rec { "${"a"}" = true; b = a; } would be an error or use a from the surrounding scope if it exists. Note that the getAttr, getAttr or default, and hasAttr are all implemented purely in the parser as syntactic sugar, while attribute sets with dynamic attribute names required changes to the AST to be implemented cleanly. This is an alternative solution to and closes #167 Signed-off-by: Shea Levy <shea@shealevy.com>
2013-09-21 03:25:30 +00:00
}
;
2021-07-29 16:03:07 +00:00
path_start
: PATH {
Path path(absPath({$1.p, $1.l}, data->basePath));
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/* add back in the trailing '/' to the first segment */
if ($1.p[$1.l-1] == '/' && $1.l > 1)
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path += "/";
$$ = new ExprPath(path);
}
| HPATH {
if (evalSettings.pureEval) {
throw Error(
"the path '%s' can not be resolved in pure mode",
std::string_view($1.p, $1.l)
);
}
Path path(getHome() + std::string($1.p + 1, $1.l - 1));
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$$ = new ExprPath(path);
}
;
ind_string_parts
: ind_string_parts IND_STR { $$ = $1; $1->emplace_back(makeCurPos(@2, data), $2); }
| ind_string_parts DOLLAR_CURLY expr '}' { $$ = $1; $1->emplace_back(makeCurPos(@2, data), $3); }
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| { $$ = new std::vector<std::pair<PosIdx, std::variant<Expr *, StringToken>>>; }
;
binds
: binds attrpath '=' expr ';' { $$ = $1; addAttr($$, *$2, $4, makeCurPos(@2, data), data->state); }
| binds INHERIT attrs ';'
{ $$ = $1;
2015-07-17 17:24:28 +00:00
for (auto & i : *$3) {
if ($$->attrs.find(i.symbol) != $$->attrs.end())
dupAttr(data->state, i.symbol, makeCurPos(@3, data), $$->attrs[i.symbol].pos);
auto pos = makeCurPos(@3, data);
$$->attrs.emplace(i.symbol, ExprAttrs::AttrDef(new ExprVar(CUR_POS, i.symbol), pos, true));
}
}
| binds INHERIT '(' expr ')' attrs ';'
{ $$ = $1;
/* !!! Should ensure sharing of the expression in $4. */
2015-07-17 17:24:28 +00:00
for (auto & i : *$6) {
if ($$->attrs.find(i.symbol) != $$->attrs.end())
dupAttr(data->state, i.symbol, makeCurPos(@6, data), $$->attrs[i.symbol].pos);
$$->attrs.emplace(i.symbol, ExprAttrs::AttrDef(new ExprSelect(CUR_POS, $4, i.symbol), makeCurPos(@6, data)));
}
}
| { $$ = new ExprAttrs(makeCurPos(@0, data)); }
;
attrs
: attrs attr { $$ = $1; $1->push_back(AttrName(data->symbols.create($2))); }
Dynamic attrs This adds new syntax for attribute names: * attrs."${name}" => getAttr name attrs * attrs ? "${name}" => isAttrs attrs && hasAttr attrs name * attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def * { "${name}" = value; } => listToAttrs [{ inherit name value; }] Of course, it's a bit more complicated than that. The attribute chains can be arbitrarily long and contain combinations of static and dynamic parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively straightforward for the getAttrs/hasAttrs cases but is more complex for the listToAttrs case due to rules about duplicate attribute definitions. For attribute sets with dynamic attribute names, duplicate static attributes are detected at parse time while duplicate dynamic attributes are detected when the attribute set is forced. So, for example, { a = null; a.b = null; "${"c"}" = true; } will be a parse-time error, while { a = {}; "${"a"}".b = null; c = true; } will be an eval-time error (technically that case could theoretically be detected at parse time, but the general case would require full evaluation). Moreover, duplicate dynamic attributes are not allowed even in cases where they would be with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but { a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction might be relaxed in the future in cases where the static variant would not be an error, but it is not obvious that that is desirable. Finally, recursive attribute sets with dynamic attributes have the static attributes in scope but not the dynamic ones. So rec { a = true; "${"b"}" = a; } is equivalent to { a = true; b = true; } but rec { "${"a"}" = true; b = a; } would be an error or use a from the surrounding scope if it exists. Note that the getAttr, getAttr or default, and hasAttr are all implemented purely in the parser as syntactic sugar, while attribute sets with dynamic attribute names required changes to the AST to be implemented cleanly. This is an alternative solution to and closes #167 Signed-off-by: Shea Levy <shea@shealevy.com>
2013-09-21 03:25:30 +00:00
| attrs string_attr
{ $$ = $1;
ExprString * str = dynamic_cast<ExprString *>($2);
Dynamic attrs This adds new syntax for attribute names: * attrs."${name}" => getAttr name attrs * attrs ? "${name}" => isAttrs attrs && hasAttr attrs name * attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def * { "${name}" = value; } => listToAttrs [{ inherit name value; }] Of course, it's a bit more complicated than that. The attribute chains can be arbitrarily long and contain combinations of static and dynamic parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively straightforward for the getAttrs/hasAttrs cases but is more complex for the listToAttrs case due to rules about duplicate attribute definitions. For attribute sets with dynamic attribute names, duplicate static attributes are detected at parse time while duplicate dynamic attributes are detected when the attribute set is forced. So, for example, { a = null; a.b = null; "${"c"}" = true; } will be a parse-time error, while { a = {}; "${"a"}".b = null; c = true; } will be an eval-time error (technically that case could theoretically be detected at parse time, but the general case would require full evaluation). Moreover, duplicate dynamic attributes are not allowed even in cases where they would be with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but { a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction might be relaxed in the future in cases where the static variant would not be an error, but it is not obvious that that is desirable. Finally, recursive attribute sets with dynamic attributes have the static attributes in scope but not the dynamic ones. So rec { a = true; "${"b"}" = a; } is equivalent to { a = true; b = true; } but rec { "${"a"}" = true; b = a; } would be an error or use a from the surrounding scope if it exists. Note that the getAttr, getAttr or default, and hasAttr are all implemented purely in the parser as syntactic sugar, while attribute sets with dynamic attribute names required changes to the AST to be implemented cleanly. This is an alternative solution to and closes #167 Signed-off-by: Shea Levy <shea@shealevy.com>
2013-09-21 03:25:30 +00:00
if (str) {
don't use Symbols for strings string expressions by and large do not need the benefits a Symbol gives us, instead they pollute the symbol table and cause unnecessary overhead for almost all strings. the one place we can think of that benefits from them (attrpaths with expressions) extracts the benefit in the parser, which we'll have to touch anyway when changing ExprString to hold strings. this gives a sizeable improvement on of 3-5% on all benchmarks we've run. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.844 s ± 0.045 s [User: 6.750 s, System: 1.663 s] Range (min … max): 8.758 s … 8.922 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 367.4 ms ± 3.3 ms [User: 332.3 ms, System: 35.2 ms] Range (min … max): 364.0 ms … 375.2 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.810 s ± 0.030 s [User: 2.517 s, System: 0.225 s] Range (min … max): 2.742 s … 2.854 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.533 s ± 0.068 s [User: 6.485 s, System: 1.642 s] Range (min … max): 8.404 s … 8.657 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 347.6 ms ± 3.1 ms [User: 313.1 ms, System: 34.5 ms] Range (min … max): 343.3 ms … 354.6 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.709 s ± 0.032 s [User: 2.414 s, System: 0.232 s] Range (min … max): 2.655 s … 2.788 s 20 runs
2022-01-19 13:31:30 +00:00
$$->push_back(AttrName(data->symbols.create(str->s)));
Dynamic attrs This adds new syntax for attribute names: * attrs."${name}" => getAttr name attrs * attrs ? "${name}" => isAttrs attrs && hasAttr attrs name * attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def * { "${name}" = value; } => listToAttrs [{ inherit name value; }] Of course, it's a bit more complicated than that. The attribute chains can be arbitrarily long and contain combinations of static and dynamic parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively straightforward for the getAttrs/hasAttrs cases but is more complex for the listToAttrs case due to rules about duplicate attribute definitions. For attribute sets with dynamic attribute names, duplicate static attributes are detected at parse time while duplicate dynamic attributes are detected when the attribute set is forced. So, for example, { a = null; a.b = null; "${"c"}" = true; } will be a parse-time error, while { a = {}; "${"a"}".b = null; c = true; } will be an eval-time error (technically that case could theoretically be detected at parse time, but the general case would require full evaluation). Moreover, duplicate dynamic attributes are not allowed even in cases where they would be with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but { a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction might be relaxed in the future in cases where the static variant would not be an error, but it is not obvious that that is desirable. Finally, recursive attribute sets with dynamic attributes have the static attributes in scope but not the dynamic ones. So rec { a = true; "${"b"}" = a; } is equivalent to { a = true; b = true; } but rec { "${"a"}" = true; b = a; } would be an error or use a from the surrounding scope if it exists. Note that the getAttr, getAttr or default, and hasAttr are all implemented purely in the parser as syntactic sugar, while attribute sets with dynamic attribute names required changes to the AST to be implemented cleanly. This is an alternative solution to and closes #167 Signed-off-by: Shea Levy <shea@shealevy.com>
2013-09-21 03:25:30 +00:00
delete str;
} else
throw ParseError({
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("dynamic attributes not allowed in inherit"),
.errPos = data->state.positions[makeCurPos(@2, data)]
});
Dynamic attrs This adds new syntax for attribute names: * attrs."${name}" => getAttr name attrs * attrs ? "${name}" => isAttrs attrs && hasAttr attrs name * attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def * { "${name}" = value; } => listToAttrs [{ inherit name value; }] Of course, it's a bit more complicated than that. The attribute chains can be arbitrarily long and contain combinations of static and dynamic parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively straightforward for the getAttrs/hasAttrs cases but is more complex for the listToAttrs case due to rules about duplicate attribute definitions. For attribute sets with dynamic attribute names, duplicate static attributes are detected at parse time while duplicate dynamic attributes are detected when the attribute set is forced. So, for example, { a = null; a.b = null; "${"c"}" = true; } will be a parse-time error, while { a = {}; "${"a"}".b = null; c = true; } will be an eval-time error (technically that case could theoretically be detected at parse time, but the general case would require full evaluation). Moreover, duplicate dynamic attributes are not allowed even in cases where they would be with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but { a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction might be relaxed in the future in cases where the static variant would not be an error, but it is not obvious that that is desirable. Finally, recursive attribute sets with dynamic attributes have the static attributes in scope but not the dynamic ones. So rec { a = true; "${"b"}" = a; } is equivalent to { a = true; b = true; } but rec { "${"a"}" = true; b = a; } would be an error or use a from the surrounding scope if it exists. Note that the getAttr, getAttr or default, and hasAttr are all implemented purely in the parser as syntactic sugar, while attribute sets with dynamic attribute names required changes to the AST to be implemented cleanly. This is an alternative solution to and closes #167 Signed-off-by: Shea Levy <shea@shealevy.com>
2013-09-21 03:25:30 +00:00
}
| { $$ = new AttrPath; }
;
attrpath
Dynamic attrs This adds new syntax for attribute names: * attrs."${name}" => getAttr name attrs * attrs ? "${name}" => isAttrs attrs && hasAttr attrs name * attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def * { "${name}" = value; } => listToAttrs [{ inherit name value; }] Of course, it's a bit more complicated than that. The attribute chains can be arbitrarily long and contain combinations of static and dynamic parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively straightforward for the getAttrs/hasAttrs cases but is more complex for the listToAttrs case due to rules about duplicate attribute definitions. For attribute sets with dynamic attribute names, duplicate static attributes are detected at parse time while duplicate dynamic attributes are detected when the attribute set is forced. So, for example, { a = null; a.b = null; "${"c"}" = true; } will be a parse-time error, while { a = {}; "${"a"}".b = null; c = true; } will be an eval-time error (technically that case could theoretically be detected at parse time, but the general case would require full evaluation). Moreover, duplicate dynamic attributes are not allowed even in cases where they would be with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but { a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction might be relaxed in the future in cases where the static variant would not be an error, but it is not obvious that that is desirable. Finally, recursive attribute sets with dynamic attributes have the static attributes in scope but not the dynamic ones. So rec { a = true; "${"b"}" = a; } is equivalent to { a = true; b = true; } but rec { "${"a"}" = true; b = a; } would be an error or use a from the surrounding scope if it exists. Note that the getAttr, getAttr or default, and hasAttr are all implemented purely in the parser as syntactic sugar, while attribute sets with dynamic attribute names required changes to the AST to be implemented cleanly. This is an alternative solution to and closes #167 Signed-off-by: Shea Levy <shea@shealevy.com>
2013-09-21 03:25:30 +00:00
: attrpath '.' attr { $$ = $1; $1->push_back(AttrName(data->symbols.create($3))); }
| attrpath '.' string_attr
{ $$ = $1;
ExprString * str = dynamic_cast<ExprString *>($3);
Dynamic attrs This adds new syntax for attribute names: * attrs."${name}" => getAttr name attrs * attrs ? "${name}" => isAttrs attrs && hasAttr attrs name * attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def * { "${name}" = value; } => listToAttrs [{ inherit name value; }] Of course, it's a bit more complicated than that. The attribute chains can be arbitrarily long and contain combinations of static and dynamic parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively straightforward for the getAttrs/hasAttrs cases but is more complex for the listToAttrs case due to rules about duplicate attribute definitions. For attribute sets with dynamic attribute names, duplicate static attributes are detected at parse time while duplicate dynamic attributes are detected when the attribute set is forced. So, for example, { a = null; a.b = null; "${"c"}" = true; } will be a parse-time error, while { a = {}; "${"a"}".b = null; c = true; } will be an eval-time error (technically that case could theoretically be detected at parse time, but the general case would require full evaluation). Moreover, duplicate dynamic attributes are not allowed even in cases where they would be with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but { a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction might be relaxed in the future in cases where the static variant would not be an error, but it is not obvious that that is desirable. Finally, recursive attribute sets with dynamic attributes have the static attributes in scope but not the dynamic ones. So rec { a = true; "${"b"}" = a; } is equivalent to { a = true; b = true; } but rec { "${"a"}" = true; b = a; } would be an error or use a from the surrounding scope if it exists. Note that the getAttr, getAttr or default, and hasAttr are all implemented purely in the parser as syntactic sugar, while attribute sets with dynamic attribute names required changes to the AST to be implemented cleanly. This is an alternative solution to and closes #167 Signed-off-by: Shea Levy <shea@shealevy.com>
2013-09-21 03:25:30 +00:00
if (str) {
don't use Symbols for strings string expressions by and large do not need the benefits a Symbol gives us, instead they pollute the symbol table and cause unnecessary overhead for almost all strings. the one place we can think of that benefits from them (attrpaths with expressions) extracts the benefit in the parser, which we'll have to touch anyway when changing ExprString to hold strings. this gives a sizeable improvement on of 3-5% on all benchmarks we've run. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.844 s ± 0.045 s [User: 6.750 s, System: 1.663 s] Range (min … max): 8.758 s … 8.922 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 367.4 ms ± 3.3 ms [User: 332.3 ms, System: 35.2 ms] Range (min … max): 364.0 ms … 375.2 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.810 s ± 0.030 s [User: 2.517 s, System: 0.225 s] Range (min … max): 2.742 s … 2.854 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.533 s ± 0.068 s [User: 6.485 s, System: 1.642 s] Range (min … max): 8.404 s … 8.657 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 347.6 ms ± 3.1 ms [User: 313.1 ms, System: 34.5 ms] Range (min … max): 343.3 ms … 354.6 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.709 s ± 0.032 s [User: 2.414 s, System: 0.232 s] Range (min … max): 2.655 s … 2.788 s 20 runs
2022-01-19 13:31:30 +00:00
$$->push_back(AttrName(data->symbols.create(str->s)));
Dynamic attrs This adds new syntax for attribute names: * attrs."${name}" => getAttr name attrs * attrs ? "${name}" => isAttrs attrs && hasAttr attrs name * attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def * { "${name}" = value; } => listToAttrs [{ inherit name value; }] Of course, it's a bit more complicated than that. The attribute chains can be arbitrarily long and contain combinations of static and dynamic parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively straightforward for the getAttrs/hasAttrs cases but is more complex for the listToAttrs case due to rules about duplicate attribute definitions. For attribute sets with dynamic attribute names, duplicate static attributes are detected at parse time while duplicate dynamic attributes are detected when the attribute set is forced. So, for example, { a = null; a.b = null; "${"c"}" = true; } will be a parse-time error, while { a = {}; "${"a"}".b = null; c = true; } will be an eval-time error (technically that case could theoretically be detected at parse time, but the general case would require full evaluation). Moreover, duplicate dynamic attributes are not allowed even in cases where they would be with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but { a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction might be relaxed in the future in cases where the static variant would not be an error, but it is not obvious that that is desirable. Finally, recursive attribute sets with dynamic attributes have the static attributes in scope but not the dynamic ones. So rec { a = true; "${"b"}" = a; } is equivalent to { a = true; b = true; } but rec { "${"a"}" = true; b = a; } would be an error or use a from the surrounding scope if it exists. Note that the getAttr, getAttr or default, and hasAttr are all implemented purely in the parser as syntactic sugar, while attribute sets with dynamic attribute names required changes to the AST to be implemented cleanly. This is an alternative solution to and closes #167 Signed-off-by: Shea Levy <shea@shealevy.com>
2013-09-21 03:25:30 +00:00
delete str;
} else
$$->push_back(AttrName($3));
Dynamic attrs This adds new syntax for attribute names: * attrs."${name}" => getAttr name attrs * attrs ? "${name}" => isAttrs attrs && hasAttr attrs name * attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def * { "${name}" = value; } => listToAttrs [{ inherit name value; }] Of course, it's a bit more complicated than that. The attribute chains can be arbitrarily long and contain combinations of static and dynamic parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively straightforward for the getAttrs/hasAttrs cases but is more complex for the listToAttrs case due to rules about duplicate attribute definitions. For attribute sets with dynamic attribute names, duplicate static attributes are detected at parse time while duplicate dynamic attributes are detected when the attribute set is forced. So, for example, { a = null; a.b = null; "${"c"}" = true; } will be a parse-time error, while { a = {}; "${"a"}".b = null; c = true; } will be an eval-time error (technically that case could theoretically be detected at parse time, but the general case would require full evaluation). Moreover, duplicate dynamic attributes are not allowed even in cases where they would be with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but { a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction might be relaxed in the future in cases where the static variant would not be an error, but it is not obvious that that is desirable. Finally, recursive attribute sets with dynamic attributes have the static attributes in scope but not the dynamic ones. So rec { a = true; "${"b"}" = a; } is equivalent to { a = true; b = true; } but rec { "${"a"}" = true; b = a; } would be an error or use a from the surrounding scope if it exists. Note that the getAttr, getAttr or default, and hasAttr are all implemented purely in the parser as syntactic sugar, while attribute sets with dynamic attribute names required changes to the AST to be implemented cleanly. This is an alternative solution to and closes #167 Signed-off-by: Shea Levy <shea@shealevy.com>
2013-09-21 03:25:30 +00:00
}
2022-02-21 15:32:34 +00:00
| attr { $$ = new std::vector<AttrName>; $$->push_back(AttrName(data->symbols.create($1))); }
Dynamic attrs This adds new syntax for attribute names: * attrs."${name}" => getAttr name attrs * attrs ? "${name}" => isAttrs attrs && hasAttr attrs name * attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def * { "${name}" = value; } => listToAttrs [{ inherit name value; }] Of course, it's a bit more complicated than that. The attribute chains can be arbitrarily long and contain combinations of static and dynamic parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively straightforward for the getAttrs/hasAttrs cases but is more complex for the listToAttrs case due to rules about duplicate attribute definitions. For attribute sets with dynamic attribute names, duplicate static attributes are detected at parse time while duplicate dynamic attributes are detected when the attribute set is forced. So, for example, { a = null; a.b = null; "${"c"}" = true; } will be a parse-time error, while { a = {}; "${"a"}".b = null; c = true; } will be an eval-time error (technically that case could theoretically be detected at parse time, but the general case would require full evaluation). Moreover, duplicate dynamic attributes are not allowed even in cases where they would be with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but { a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction might be relaxed in the future in cases where the static variant would not be an error, but it is not obvious that that is desirable. Finally, recursive attribute sets with dynamic attributes have the static attributes in scope but not the dynamic ones. So rec { a = true; "${"b"}" = a; } is equivalent to { a = true; b = true; } but rec { "${"a"}" = true; b = a; } would be an error or use a from the surrounding scope if it exists. Note that the getAttr, getAttr or default, and hasAttr are all implemented purely in the parser as syntactic sugar, while attribute sets with dynamic attribute names required changes to the AST to be implemented cleanly. This is an alternative solution to and closes #167 Signed-off-by: Shea Levy <shea@shealevy.com>
2013-09-21 03:25:30 +00:00
| string_attr
2022-02-21 15:32:34 +00:00
{ $$ = new std::vector<AttrName>;
Dynamic attrs This adds new syntax for attribute names: * attrs."${name}" => getAttr name attrs * attrs ? "${name}" => isAttrs attrs && hasAttr attrs name * attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def * { "${name}" = value; } => listToAttrs [{ inherit name value; }] Of course, it's a bit more complicated than that. The attribute chains can be arbitrarily long and contain combinations of static and dynamic parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively straightforward for the getAttrs/hasAttrs cases but is more complex for the listToAttrs case due to rules about duplicate attribute definitions. For attribute sets with dynamic attribute names, duplicate static attributes are detected at parse time while duplicate dynamic attributes are detected when the attribute set is forced. So, for example, { a = null; a.b = null; "${"c"}" = true; } will be a parse-time error, while { a = {}; "${"a"}".b = null; c = true; } will be an eval-time error (technically that case could theoretically be detected at parse time, but the general case would require full evaluation). Moreover, duplicate dynamic attributes are not allowed even in cases where they would be with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but { a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction might be relaxed in the future in cases where the static variant would not be an error, but it is not obvious that that is desirable. Finally, recursive attribute sets with dynamic attributes have the static attributes in scope but not the dynamic ones. So rec { a = true; "${"b"}" = a; } is equivalent to { a = true; b = true; } but rec { "${"a"}" = true; b = a; } would be an error or use a from the surrounding scope if it exists. Note that the getAttr, getAttr or default, and hasAttr are all implemented purely in the parser as syntactic sugar, while attribute sets with dynamic attribute names required changes to the AST to be implemented cleanly. This is an alternative solution to and closes #167 Signed-off-by: Shea Levy <shea@shealevy.com>
2013-09-21 03:25:30 +00:00
ExprString *str = dynamic_cast<ExprString *>($1);
if (str) {
don't use Symbols for strings string expressions by and large do not need the benefits a Symbol gives us, instead they pollute the symbol table and cause unnecessary overhead for almost all strings. the one place we can think of that benefits from them (attrpaths with expressions) extracts the benefit in the parser, which we'll have to touch anyway when changing ExprString to hold strings. this gives a sizeable improvement on of 3-5% on all benchmarks we've run. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.844 s ± 0.045 s [User: 6.750 s, System: 1.663 s] Range (min … max): 8.758 s … 8.922 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 367.4 ms ± 3.3 ms [User: 332.3 ms, System: 35.2 ms] Range (min … max): 364.0 ms … 375.2 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.810 s ± 0.030 s [User: 2.517 s, System: 0.225 s] Range (min … max): 2.742 s … 2.854 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.533 s ± 0.068 s [User: 6.485 s, System: 1.642 s] Range (min … max): 8.404 s … 8.657 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 347.6 ms ± 3.1 ms [User: 313.1 ms, System: 34.5 ms] Range (min … max): 343.3 ms … 354.6 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.709 s ± 0.032 s [User: 2.414 s, System: 0.232 s] Range (min … max): 2.655 s … 2.788 s 20 runs
2022-01-19 13:31:30 +00:00
$$->push_back(AttrName(data->symbols.create(str->s)));
Dynamic attrs This adds new syntax for attribute names: * attrs."${name}" => getAttr name attrs * attrs ? "${name}" => isAttrs attrs && hasAttr attrs name * attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def * { "${name}" = value; } => listToAttrs [{ inherit name value; }] Of course, it's a bit more complicated than that. The attribute chains can be arbitrarily long and contain combinations of static and dynamic parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively straightforward for the getAttrs/hasAttrs cases but is more complex for the listToAttrs case due to rules about duplicate attribute definitions. For attribute sets with dynamic attribute names, duplicate static attributes are detected at parse time while duplicate dynamic attributes are detected when the attribute set is forced. So, for example, { a = null; a.b = null; "${"c"}" = true; } will be a parse-time error, while { a = {}; "${"a"}".b = null; c = true; } will be an eval-time error (technically that case could theoretically be detected at parse time, but the general case would require full evaluation). Moreover, duplicate dynamic attributes are not allowed even in cases where they would be with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but { a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction might be relaxed in the future in cases where the static variant would not be an error, but it is not obvious that that is desirable. Finally, recursive attribute sets with dynamic attributes have the static attributes in scope but not the dynamic ones. So rec { a = true; "${"b"}" = a; } is equivalent to { a = true; b = true; } but rec { "${"a"}" = true; b = a; } would be an error or use a from the surrounding scope if it exists. Note that the getAttr, getAttr or default, and hasAttr are all implemented purely in the parser as syntactic sugar, while attribute sets with dynamic attribute names required changes to the AST to be implemented cleanly. This is an alternative solution to and closes #167 Signed-off-by: Shea Levy <shea@shealevy.com>
2013-09-21 03:25:30 +00:00
delete str;
} else
$$->push_back(AttrName($1));
Dynamic attrs This adds new syntax for attribute names: * attrs."${name}" => getAttr name attrs * attrs ? "${name}" => isAttrs attrs && hasAttr attrs name * attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def * { "${name}" = value; } => listToAttrs [{ inherit name value; }] Of course, it's a bit more complicated than that. The attribute chains can be arbitrarily long and contain combinations of static and dynamic parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively straightforward for the getAttrs/hasAttrs cases but is more complex for the listToAttrs case due to rules about duplicate attribute definitions. For attribute sets with dynamic attribute names, duplicate static attributes are detected at parse time while duplicate dynamic attributes are detected when the attribute set is forced. So, for example, { a = null; a.b = null; "${"c"}" = true; } will be a parse-time error, while { a = {}; "${"a"}".b = null; c = true; } will be an eval-time error (technically that case could theoretically be detected at parse time, but the general case would require full evaluation). Moreover, duplicate dynamic attributes are not allowed even in cases where they would be with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but { a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction might be relaxed in the future in cases where the static variant would not be an error, but it is not obvious that that is desirable. Finally, recursive attribute sets with dynamic attributes have the static attributes in scope but not the dynamic ones. So rec { a = true; "${"b"}" = a; } is equivalent to { a = true; b = true; } but rec { "${"a"}" = true; b = a; } would be an error or use a from the surrounding scope if it exists. Note that the getAttr, getAttr or default, and hasAttr are all implemented purely in the parser as syntactic sugar, while attribute sets with dynamic attribute names required changes to the AST to be implemented cleanly. This is an alternative solution to and closes #167 Signed-off-by: Shea Levy <shea@shealevy.com>
2013-09-21 03:25:30 +00:00
}
;
attr
: ID { $$ = $1; }
| OR_KW { $$ = {"or", 2}; }
Dynamic attrs This adds new syntax for attribute names: * attrs."${name}" => getAttr name attrs * attrs ? "${name}" => isAttrs attrs && hasAttr attrs name * attrs."${name}" or def => if attrs ? "${name}" then attrs."${name}" else def * { "${name}" = value; } => listToAttrs [{ inherit name value; }] Of course, it's a bit more complicated than that. The attribute chains can be arbitrarily long and contain combinations of static and dynamic parts (e.g. attrs."${foo}".bar."${baz}" or qux), which is relatively straightforward for the getAttrs/hasAttrs cases but is more complex for the listToAttrs case due to rules about duplicate attribute definitions. For attribute sets with dynamic attribute names, duplicate static attributes are detected at parse time while duplicate dynamic attributes are detected when the attribute set is forced. So, for example, { a = null; a.b = null; "${"c"}" = true; } will be a parse-time error, while { a = {}; "${"a"}".b = null; c = true; } will be an eval-time error (technically that case could theoretically be detected at parse time, but the general case would require full evaluation). Moreover, duplicate dynamic attributes are not allowed even in cases where they would be with static attributes ({ a.b.d = true; a.b.c = false; } is legal, but { a."${"b"}".d = true; a."${"b"}".c = false; } is not). This restriction might be relaxed in the future in cases where the static variant would not be an error, but it is not obvious that that is desirable. Finally, recursive attribute sets with dynamic attributes have the static attributes in scope but not the dynamic ones. So rec { a = true; "${"b"}" = a; } is equivalent to { a = true; b = true; } but rec { "${"a"}" = true; b = a; } would be an error or use a from the surrounding scope if it exists. Note that the getAttr, getAttr or default, and hasAttr are all implemented purely in the parser as syntactic sugar, while attribute sets with dynamic attribute names required changes to the AST to be implemented cleanly. This is an alternative solution to and closes #167 Signed-off-by: Shea Levy <shea@shealevy.com>
2013-09-21 03:25:30 +00:00
;
string_attr
: '"' string_parts '"' { $$ = $2; }
| DOLLAR_CURLY expr '}' { $$ = $2; }
;
expr_list
: expr_list expr_select { $$ = $1; $1->elems.push_back($2); /* !!! dangerous */ }
| { $$ = new ExprList; }
;
formals
: formal ',' formals
defer formals duplicate check for incresed efficiency all round if we defer the duplicate argument check for lambda formals we can use more efficient data structures for the formals set, and we can get rid of the duplication of formals names to boot. instead of a list of formals we've seen and a set of names we'll keep a vector instead and run a sort+dupcheck step before moving the parsed formals into a newly created lambda. this improves performance on search and rebuild by ~1%, pure parsing gains more (about 4%). this does reorder lambda arguments in the xml output, but the output is still stable. this shouldn't be a problem since argument order is not semantically important anyway. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.550 s ± 0.060 s [User: 6.470 s, System: 1.664 s] Range (min … max): 8.435 s … 8.666 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 346.7 ms ± 2.1 ms [User: 312.4 ms, System: 34.2 ms] Range (min … max): 343.8 ms … 353.4 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.720 s ± 0.031 s [User: 2.415 s, System: 0.231 s] Range (min … max): 2.662 s … 2.780 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.462 s ± 0.063 s [User: 6.398 s, System: 1.661 s] Range (min … max): 8.339 s … 8.542 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 329.1 ms ± 1.4 ms [User: 296.8 ms, System: 32.3 ms] Range (min … max): 326.1 ms … 330.8 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.687 s ± 0.035 s [User: 2.392 s, System: 0.228 s] Range (min … max): 2.626 s … 2.754 s 20 runs
2022-01-19 15:49:02 +00:00
{ $$ = $3; $$->formals.push_back(*$1); }
| formal
defer formals duplicate check for incresed efficiency all round if we defer the duplicate argument check for lambda formals we can use more efficient data structures for the formals set, and we can get rid of the duplication of formals names to boot. instead of a list of formals we've seen and a set of names we'll keep a vector instead and run a sort+dupcheck step before moving the parsed formals into a newly created lambda. this improves performance on search and rebuild by ~1%, pure parsing gains more (about 4%). this does reorder lambda arguments in the xml output, but the output is still stable. this shouldn't be a problem since argument order is not semantically important anyway. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.550 s ± 0.060 s [User: 6.470 s, System: 1.664 s] Range (min … max): 8.435 s … 8.666 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 346.7 ms ± 2.1 ms [User: 312.4 ms, System: 34.2 ms] Range (min … max): 343.8 ms … 353.4 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.720 s ± 0.031 s [User: 2.415 s, System: 0.231 s] Range (min … max): 2.662 s … 2.780 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.462 s ± 0.063 s [User: 6.398 s, System: 1.661 s] Range (min … max): 8.339 s … 8.542 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 329.1 ms ± 1.4 ms [User: 296.8 ms, System: 32.3 ms] Range (min … max): 326.1 ms … 330.8 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.687 s ± 0.035 s [User: 2.392 s, System: 0.228 s] Range (min … max): 2.626 s … 2.754 s 20 runs
2022-01-19 15:49:02 +00:00
{ $$ = new ParserFormals; $$->formals.push_back(*$1); $$->ellipsis = false; }
|
defer formals duplicate check for incresed efficiency all round if we defer the duplicate argument check for lambda formals we can use more efficient data structures for the formals set, and we can get rid of the duplication of formals names to boot. instead of a list of formals we've seen and a set of names we'll keep a vector instead and run a sort+dupcheck step before moving the parsed formals into a newly created lambda. this improves performance on search and rebuild by ~1%, pure parsing gains more (about 4%). this does reorder lambda arguments in the xml output, but the output is still stable. this shouldn't be a problem since argument order is not semantically important anyway. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.550 s ± 0.060 s [User: 6.470 s, System: 1.664 s] Range (min … max): 8.435 s … 8.666 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 346.7 ms ± 2.1 ms [User: 312.4 ms, System: 34.2 ms] Range (min … max): 343.8 ms … 353.4 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.720 s ± 0.031 s [User: 2.415 s, System: 0.231 s] Range (min … max): 2.662 s … 2.780 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.462 s ± 0.063 s [User: 6.398 s, System: 1.661 s] Range (min … max): 8.339 s … 8.542 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 329.1 ms ± 1.4 ms [User: 296.8 ms, System: 32.3 ms] Range (min … max): 326.1 ms … 330.8 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.687 s ± 0.035 s [User: 2.392 s, System: 0.228 s] Range (min … max): 2.626 s … 2.754 s 20 runs
2022-01-19 15:49:02 +00:00
{ $$ = new ParserFormals; $$->ellipsis = false; }
| ELLIPSIS
defer formals duplicate check for incresed efficiency all round if we defer the duplicate argument check for lambda formals we can use more efficient data structures for the formals set, and we can get rid of the duplication of formals names to boot. instead of a list of formals we've seen and a set of names we'll keep a vector instead and run a sort+dupcheck step before moving the parsed formals into a newly created lambda. this improves performance on search and rebuild by ~1%, pure parsing gains more (about 4%). this does reorder lambda arguments in the xml output, but the output is still stable. this shouldn't be a problem since argument order is not semantically important anyway. before nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.550 s ± 0.060 s [User: 6.470 s, System: 1.664 s] Range (min … max): 8.435 s … 8.666 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 346.7 ms ± 2.1 ms [User: 312.4 ms, System: 34.2 ms] Range (min … max): 343.8 ms … 353.4 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.720 s ± 0.031 s [User: 2.415 s, System: 0.231 s] Range (min … max): 2.662 s … 2.780 s 20 runs after nix search --no-eval-cache --offline ../nixpkgs hello Time (mean ± σ): 8.462 s ± 0.063 s [User: 6.398 s, System: 1.661 s] Range (min … max): 8.339 s … 8.542 s 20 runs nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 329.1 ms ± 1.4 ms [User: 296.8 ms, System: 32.3 ms] Range (min … max): 326.1 ms … 330.8 ms 20 runs nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.687 s ± 0.035 s [User: 2.392 s, System: 0.228 s] Range (min … max): 2.626 s … 2.754 s 20 runs
2022-01-19 15:49:02 +00:00
{ $$ = new ParserFormals; $$->ellipsis = true; }
;
formal
: ID { $$ = new Formal{CUR_POS, data->symbols.create($1), 0}; }
| ID '?' expr { $$ = new Formal{CUR_POS, data->symbols.create($1), $3}; }
;
2013-09-02 14:29:15 +00:00
%%
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include "eval.hh"
#include "filetransfer.hh"
#include "fetchers.hh"
#include "store-api.hh"
#include "flake/flake.hh"
namespace nix {
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Expr * EvalState::parse(
char * text,
size_t length,
Pos::Origin origin,
Path basePath,
std::shared_ptr<StaticEnv> & staticEnv)
{
yyscan_t scanner;
ParseData data {
.state = *this,
.symbols = symbols,
.basePath = std::move(basePath),
.origin = {origin},
};
yylex_init(&scanner);
avoid copies of parser input data when given a string yacc will copy the entire input to a newly allocated location so that it can add a second terminating NUL byte. since the parser is a very internal thing to EvalState we can ensure that having two terminating NUL bytes is always possible without copying, and have the parser itself merely check that the expected NULs are present. # before Benchmark 1: nix search --offline nixpkgs hello Time (mean ± σ): 572.4 ms ± 2.3 ms [User: 563.4 ms, System: 8.6 ms] Range (min … max): 566.9 ms … 579.1 ms 50 runs Benchmark 2: nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 381.7 ms ± 1.0 ms [User: 348.3 ms, System: 33.1 ms] Range (min … max): 380.2 ms … 387.7 ms 50 runs Benchmark 3: nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.936 s ± 0.005 s [User: 2.715 s, System: 0.221 s] Range (min … max): 2.923 s … 2.946 s 50 runs # after Benchmark 1: nix search --offline nixpkgs hello Time (mean ± σ): 571.7 ms ± 2.4 ms [User: 563.3 ms, System: 8.0 ms] Range (min … max): 566.7 ms … 579.7 ms 50 runs Benchmark 2: nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 376.6 ms ± 1.0 ms [User: 345.8 ms, System: 30.5 ms] Range (min … max): 374.5 ms … 379.1 ms 50 runs Benchmark 3: nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.922 s ± 0.006 s [User: 2.707 s, System: 0.215 s] Range (min … max): 2.906 s … 2.934 s 50 runs
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yy_scan_buffer(text, length, scanner);
int res = yyparse(scanner, &data);
yylex_destroy(scanner);
2013-09-02 14:29:15 +00:00
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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if (res) throw ParseError(data.error.value());
data.result->bindVars(*this, staticEnv);
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return data.result;
}
Path resolveExprPath(Path path)
{
assert(path[0] == '/');
unsigned int followCount = 0, maxFollow = 1024;
/* If `path' is a symlink, follow it. This is so that relative
path references work. */
struct stat st;
while (true) {
// Basic cycle/depth limit to avoid infinite loops.
if (++followCount >= maxFollow)
2019-12-15 09:44:53 +00:00
throw Error("too many symbolic links encountered while traversing the path '%s'", path);
2020-09-23 17:17:28 +00:00
st = lstat(path);
if (!S_ISLNK(st.st_mode)) break;
path = absPath(readLink(path), dirOf(path));
}
/* If `path' refers to a directory, append `/default.nix'. */
if (S_ISDIR(st.st_mode))
path = canonPath(path + "/default.nix");
return path;
}
Expr * EvalState::parseExprFromFile(const Path & path)
{
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.
2014-05-26 11:46:11 +00:00
return parseExprFromFile(path, staticBaseEnv);
}
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Expr * EvalState::parseExprFromFile(const Path & path, std::shared_ptr<StaticEnv> & 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.
2014-05-26 11:46:11 +00:00
{
avoid copies of parser input data when given a string yacc will copy the entire input to a newly allocated location so that it can add a second terminating NUL byte. since the parser is a very internal thing to EvalState we can ensure that having two terminating NUL bytes is always possible without copying, and have the parser itself merely check that the expected NULs are present. # before Benchmark 1: nix search --offline nixpkgs hello Time (mean ± σ): 572.4 ms ± 2.3 ms [User: 563.4 ms, System: 8.6 ms] Range (min … max): 566.9 ms … 579.1 ms 50 runs Benchmark 2: nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 381.7 ms ± 1.0 ms [User: 348.3 ms, System: 33.1 ms] Range (min … max): 380.2 ms … 387.7 ms 50 runs Benchmark 3: nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.936 s ± 0.005 s [User: 2.715 s, System: 0.221 s] Range (min … max): 2.923 s … 2.946 s 50 runs # after Benchmark 1: nix search --offline nixpkgs hello Time (mean ± σ): 571.7 ms ± 2.4 ms [User: 563.3 ms, System: 8.0 ms] Range (min … max): 566.7 ms … 579.7 ms 50 runs Benchmark 2: nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 376.6 ms ± 1.0 ms [User: 345.8 ms, System: 30.5 ms] Range (min … max): 374.5 ms … 379.1 ms 50 runs Benchmark 3: nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.922 s ± 0.006 s [User: 2.707 s, System: 0.215 s] Range (min … max): 2.906 s … 2.934 s 50 runs
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auto buffer = readFile(path);
// readFile should have left some extra space for terminators
buffer.append("\0\0", 2);
return parse(buffer.data(), buffer.size(), path, dirOf(path), staticEnv);
}
Expr * EvalState::parseExprFromString(std::string s_, const Path & basePath, std::shared_ptr<StaticEnv> & staticEnv)
2013-09-02 16:34:04 +00:00
{
auto s = make_ref<std::string>(std::move(s_));
s->append("\0\0", 2);
return parse(s->data(), s->size(), Pos::String{.source = s}, basePath, staticEnv);
2013-09-02 16:34:04 +00:00
}
avoid copies of parser input data when given a string yacc will copy the entire input to a newly allocated location so that it can add a second terminating NUL byte. since the parser is a very internal thing to EvalState we can ensure that having two terminating NUL bytes is always possible without copying, and have the parser itself merely check that the expected NULs are present. # before Benchmark 1: nix search --offline nixpkgs hello Time (mean ± σ): 572.4 ms ± 2.3 ms [User: 563.4 ms, System: 8.6 ms] Range (min … max): 566.9 ms … 579.1 ms 50 runs Benchmark 2: nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 381.7 ms ± 1.0 ms [User: 348.3 ms, System: 33.1 ms] Range (min … max): 380.2 ms … 387.7 ms 50 runs Benchmark 3: nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.936 s ± 0.005 s [User: 2.715 s, System: 0.221 s] Range (min … max): 2.923 s … 2.946 s 50 runs # after Benchmark 1: nix search --offline nixpkgs hello Time (mean ± σ): 571.7 ms ± 2.4 ms [User: 563.3 ms, System: 8.0 ms] Range (min … max): 566.7 ms … 579.7 ms 50 runs Benchmark 2: nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 376.6 ms ± 1.0 ms [User: 345.8 ms, System: 30.5 ms] Range (min … max): 374.5 ms … 379.1 ms 50 runs Benchmark 3: nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.922 s ± 0.006 s [User: 2.707 s, System: 0.215 s] Range (min … max): 2.906 s … 2.934 s 50 runs
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Expr * EvalState::parseExprFromString(std::string s, const Path & basePath)
{
avoid copies of parser input data when given a string yacc will copy the entire input to a newly allocated location so that it can add a second terminating NUL byte. since the parser is a very internal thing to EvalState we can ensure that having two terminating NUL bytes is always possible without copying, and have the parser itself merely check that the expected NULs are present. # before Benchmark 1: nix search --offline nixpkgs hello Time (mean ± σ): 572.4 ms ± 2.3 ms [User: 563.4 ms, System: 8.6 ms] Range (min … max): 566.9 ms … 579.1 ms 50 runs Benchmark 2: nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 381.7 ms ± 1.0 ms [User: 348.3 ms, System: 33.1 ms] Range (min … max): 380.2 ms … 387.7 ms 50 runs Benchmark 3: nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.936 s ± 0.005 s [User: 2.715 s, System: 0.221 s] Range (min … max): 2.923 s … 2.946 s 50 runs # after Benchmark 1: nix search --offline nixpkgs hello Time (mean ± σ): 571.7 ms ± 2.4 ms [User: 563.3 ms, System: 8.0 ms] Range (min … max): 566.7 ms … 579.7 ms 50 runs Benchmark 2: nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 376.6 ms ± 1.0 ms [User: 345.8 ms, System: 30.5 ms] Range (min … max): 374.5 ms … 379.1 ms 50 runs Benchmark 3: nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.922 s ± 0.006 s [User: 2.707 s, System: 0.215 s] Range (min … max): 2.906 s … 2.934 s 50 runs
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return parseExprFromString(std::move(s), basePath, staticBaseEnv);
}
Expr * EvalState::parseStdin()
{
//Activity act(*logger, lvlTalkative, format("parsing standard input"));
avoid copies of parser input data when given a string yacc will copy the entire input to a newly allocated location so that it can add a second terminating NUL byte. since the parser is a very internal thing to EvalState we can ensure that having two terminating NUL bytes is always possible without copying, and have the parser itself merely check that the expected NULs are present. # before Benchmark 1: nix search --offline nixpkgs hello Time (mean ± σ): 572.4 ms ± 2.3 ms [User: 563.4 ms, System: 8.6 ms] Range (min … max): 566.9 ms … 579.1 ms 50 runs Benchmark 2: nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 381.7 ms ± 1.0 ms [User: 348.3 ms, System: 33.1 ms] Range (min … max): 380.2 ms … 387.7 ms 50 runs Benchmark 3: nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.936 s ± 0.005 s [User: 2.715 s, System: 0.221 s] Range (min … max): 2.923 s … 2.946 s 50 runs # after Benchmark 1: nix search --offline nixpkgs hello Time (mean ± σ): 571.7 ms ± 2.4 ms [User: 563.3 ms, System: 8.0 ms] Range (min … max): 566.7 ms … 579.7 ms 50 runs Benchmark 2: nix eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix Time (mean ± σ): 376.6 ms ± 1.0 ms [User: 345.8 ms, System: 30.5 ms] Range (min … max): 374.5 ms … 379.1 ms 50 runs Benchmark 3: nix eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' Time (mean ± σ): 2.922 s ± 0.006 s [User: 2.707 s, System: 0.215 s] Range (min … max): 2.906 s … 2.934 s 50 runs
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auto buffer = drainFD(0);
// drainFD should have left some extra space for terminators
buffer.append("\0\0", 2);
auto s = make_ref<std::string>(std::move(buffer));
return parse(s->data(), s->size(), Pos::Stdin{.source = s}, absPath("."), staticBaseEnv);
}
void EvalState::addToSearchPath(const std::string & s)
{
size_t pos = s.find('=');
std::string prefix;
Path path;
if (pos == std::string::npos) {
path = s;
} else {
prefix = std::string(s, 0, pos);
path = std::string(s, pos + 1);
}
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searchPath.emplace_back(prefix, path);
}
Path EvalState::findFile(const std::string_view path)
{
return findFile(searchPath, path);
}
Path EvalState::findFile(SearchPath & searchPath, const std::string_view path, const PosIdx pos)
{
for (auto & i : searchPath) {
std::string suffix;
if (i.first.empty())
suffix = concatStrings("/", path);
else {
auto s = i.first.size();
if (path.compare(0, s, i.first) != 0 ||
(path.size() > s && path[s] != '/'))
continue;
suffix = path.size() == s ? "" : concatStrings("/", path.substr(s));
}
auto r = resolveSearchPathElem(i);
if (!r.first) continue;
Path res = r.second + suffix;
if (pathExists(res)) return canonPath(res);
}
if (hasPrefix(path, "nix/"))
return concatStrings(corepkgsPrefix, path.substr(4));
debugThrow(ThrownError({
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(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]
}), 0, 0);
}
std::pair<bool, std::string> EvalState::resolveSearchPathElem(const SearchPathElem & elem)
{
auto i = searchPathResolved.find(elem.second);
if (i != searchPathResolved.end()) return i->second;
std::pair<bool, std::string> res;
if (EvalSettings::isPseudoUrl(elem.second)) {
try {
auto storePath = fetchers::downloadTarball(
store, EvalSettings::resolvePseudoUrl(elem.second), "source", false).first.storePath;
res = { true, store->toRealPath(storePath) };
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} catch (FileTransferError & e) {
logWarning({
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("Nix search path entry '%1%' cannot be downloaded, ignoring", elem.second)
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});
res = { false, "" };
}
}
else if (hasPrefix(elem.second, "flake:")) {
settings.requireExperimentalFeature(Xp::Flakes);
auto flakeRef = parseFlakeRef(elem.second.substr(6), {}, true, false);
debug("fetching flake search path element '%s''", elem.second);
auto storePath = flakeRef.resolve(store).fetchTree(store).first.storePath;
res = { true, store->toRealPath(storePath) };
}
else {
auto path = absPath(elem.second);
if (pathExists(path))
res = { true, path };
else {
logWarning({
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.msg = hintfmt("Nix search path entry '%1%' does not exist, ignoring", elem.second)
});
res = { false, "" };
}
}
debug(format("resolved search path element '%s' to '%s'") % elem.second % res.second);
searchPathResolved[elem.second] = res;
return res;
}
}