don't repeatedly look up ast internal symbols

these symbols are used a *lot*, so it makes sense to cache them. this
mostly increases clarity of the code (however clear one may wish to call
the parser desugaring here), but it also provides a small performance
benefit.

(cherry picked from commit 09a1128d9e2ff0ae6176784938047350d6f8a782)
Change-Id: I73d9f66be4555168e048cb2d542277251580c2d1
This commit is contained in:
eldritch horrors 2024-03-08 05:37:19 +01:00
parent 92693973b6
commit f7b2476415
5 changed files with 36 additions and 15 deletions

View file

@ -414,6 +414,16 @@ EvalState::EvalState(
, sPath(symbols.create("path"))
, sPrefix(symbols.create("prefix"))
, sOutputSpecified(symbols.create("outputSpecified"))
, exprSymbols{
.sub = symbols.create("__sub"),
.lessThan = symbols.create("__lessThan"),
.mul = symbols.create("__mul"),
.div = symbols.create("__div"),
.or_ = symbols.create("or"),
.findFile = symbols.create("__findFile"),
.nixPath = symbols.create("__nixPath"),
.body = symbols.create("body")
}
, repair(NoRepair)
, emptyBindings(0)
, derivationInternal(rootPath(CanonPath("/builtin/derivation.nix")))
@ -2815,7 +2825,7 @@ Expr * EvalState::parse(
const SourcePath & basePath,
std::shared_ptr<StaticEnv> & staticEnv)
{
auto result = parseExprFromBuf(text, length, origin, basePath, symbols, positions);
auto result = parseExprFromBuf(text, length, origin, basePath, symbols, positions, exprSymbols);
result->bindVars(*this, staticEnv);

View file

@ -206,6 +206,8 @@ public:
sPrefix,
sOutputSpecified;
const Expr::AstSymbols exprSymbols;
/**
* If set, force copying files to the Nix store even if they
* already exist there.

View file

@ -141,6 +141,11 @@ std::string showAttrPath(const SymbolTable & symbols, const AttrPath & attrPath)
struct Expr
{
struct AstSymbols {
Symbol sub, lessThan, mul, div, or_, findFile, nixPath, body;
};
virtual ~Expr() { };
virtual void show(const SymbolTable & symbols, std::ostream & str) const;
virtual void bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env);

View file

@ -42,6 +42,7 @@ struct ParserState {
Expr * result;
SourcePath basePath;
PosTable::Origin origin;
const Expr::AstSymbols & s;
void dupAttr(const AttrPath & attrPath, const PosIdx pos, const PosIdx prevPos);
void dupAttr(Symbol attr, const PosIdx pos, const PosIdx prevPos);

View file

@ -39,7 +39,8 @@ Expr * parseExprFromBuf(
Pos::Origin origin,
const SourcePath & basePath,
SymbolTable & symbols,
PosTable & positions);
PosTable & positions,
const Expr::AstSymbols & astSymbols);
}
@ -166,13 +167,13 @@ expr_if
expr_op
: '!' expr_op %prec NOT { $$ = new ExprOpNot($2); }
| '-' expr_op %prec NEGATE { $$ = new ExprCall(CUR_POS, new ExprVar(state->symbols.create("__sub")), {new ExprInt(0), $2}); }
| '-' expr_op %prec NEGATE { $$ = new ExprCall(CUR_POS, new ExprVar(state->s.sub), {new ExprInt(0), $2}); }
| expr_op EQ expr_op { $$ = new ExprOpEq($1, $3); }
| expr_op NEQ expr_op { $$ = new ExprOpNEq($1, $3); }
| expr_op '<' expr_op { $$ = new ExprCall(state->at(@2), new ExprVar(state->symbols.create("__lessThan")), {$1, $3}); }
| expr_op LEQ expr_op { $$ = new ExprOpNot(new ExprCall(state->at(@2), new ExprVar(state->symbols.create("__lessThan")), {$3, $1})); }
| expr_op '>' expr_op { $$ = new ExprCall(state->at(@2), new ExprVar(state->symbols.create("__lessThan")), {$3, $1}); }
| expr_op GEQ expr_op { $$ = new ExprOpNot(new ExprCall(state->at(@2), new ExprVar(state->symbols.create("__lessThan")), {$1, $3})); }
| expr_op '<' expr_op { $$ = new ExprCall(state->at(@2), new ExprVar(state->s.lessThan), {$1, $3}); }
| expr_op LEQ expr_op { $$ = new ExprOpNot(new ExprCall(state->at(@2), new ExprVar(state->s.lessThan), {$3, $1})); }
| expr_op '>' expr_op { $$ = new ExprCall(state->at(@2), new ExprVar(state->s.lessThan), {$3, $1}); }
| expr_op GEQ expr_op { $$ = new ExprOpNot(new ExprCall(state->at(@2), new ExprVar(state->s.lessThan), {$1, $3})); }
| expr_op AND expr_op { $$ = new ExprOpAnd(state->at(@2), $1, $3); }
| expr_op OR expr_op { $$ = new ExprOpOr(state->at(@2), $1, $3); }
| expr_op IMPL expr_op { $$ = new ExprOpImpl(state->at(@2), $1, $3); }
@ -180,9 +181,9 @@ expr_op
| expr_op '?' attrpath { $$ = new ExprOpHasAttr($1, std::move(*$3)); delete $3; }
| expr_op '+' expr_op
{ $$ = new ExprConcatStrings(state->at(@2), false, new std::vector<std::pair<PosIdx, Expr *> >({{state->at(@1), $1}, {state->at(@3), $3}})); }
| expr_op '-' expr_op { $$ = new ExprCall(state->at(@2), new ExprVar(state->symbols.create("__sub")), {$1, $3}); }
| expr_op '*' expr_op { $$ = new ExprCall(state->at(@2), new ExprVar(state->symbols.create("__mul")), {$1, $3}); }
| expr_op '/' expr_op { $$ = new ExprCall(state->at(@2), new ExprVar(state->symbols.create("__div")), {$1, $3}); }
| expr_op '-' expr_op { $$ = new ExprCall(state->at(@2), new ExprVar(state->s.sub), {$1, $3}); }
| expr_op '*' expr_op { $$ = new ExprCall(state->at(@2), new ExprVar(state->s.mul), {$1, $3}); }
| expr_op '/' expr_op { $$ = new ExprCall(state->at(@2), new ExprVar(state->s.div), {$1, $3}); }
| expr_op CONCAT expr_op { $$ = new ExprOpConcatLists(state->at(@2), $1, $3); }
| expr_app
;
@ -206,7 +207,7 @@ expr_select
| /* Backwards compatibility: because Nixpkgs has a rarely used
function named or, allow stuff like map or [...]. */
expr_simple OR_KW
{ $$ = new ExprCall(CUR_POS, $1, {new ExprVar(CUR_POS, state->symbols.create("or"))}); }
{ $$ = new ExprCall(CUR_POS, $1, {new ExprVar(CUR_POS, state->s.or_)}); }
| expr_simple
;
@ -233,8 +234,8 @@ expr_simple
| SPATH {
std::string path($1.p + 1, $1.l - 2);
$$ = new ExprCall(CUR_POS,
new ExprVar(state->symbols.create("__findFile")),
{new ExprVar(state->symbols.create("__nixPath")),
new ExprVar(state->s.findFile),
{new ExprVar(state->s.nixPath),
new ExprString(std::move(path))});
}
| URI {
@ -250,7 +251,7 @@ expr_simple
/* Let expressions `let {..., body = ...}' are just desugared
into `(rec {..., body = ...}).body'. */
| LET '{' binds '}'
{ $3->recursive = true; $$ = new ExprSelect(noPos, $3, state->symbols.create("body")); }
{ $3->recursive = true; $$ = new ExprSelect(noPos, $3, state->s.body); }
| REC '{' binds '}'
{ $3->recursive = true; $$ = $3; }
| '{' binds '}'
@ -411,7 +412,8 @@ Expr * parseExprFromBuf(
Pos::Origin origin,
const SourcePath & basePath,
SymbolTable & symbols,
PosTable & positions)
PosTable & positions,
const Expr::AstSymbols & astSymbols)
{
yyscan_t scanner;
ParserState state {
@ -419,6 +421,7 @@ Expr * parseExprFromBuf(
.positions = positions,
.basePath = basePath,
.origin = {origin},
.s = astSymbols,
};
yylex_init(&scanner);