diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 062d190b6..b4b4f7b5c 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -594,6 +594,8 @@ Value * EvalState::addConstant(const string & name, Value & v) Value * EvalState::addPrimOp(const string & name, size_t arity, PrimOpFun primOp) { + assert(arity <= maxPrimOpArity); + auto name2 = string(name, 0, 2) == "__" ? string(name, 2) : name; Symbol sym = symbols.create(name2); @@ -1251,144 +1253,182 @@ void ExprLambda::eval(EvalState & state, Env & env, Value & v) } -void ExprApp::eval(EvalState & state, Env & env, Value & v) -{ - /* FIXME: vFun prevents GCC from doing tail call optimisation. */ - Value vFun; - e1->eval(state, env, vFun); - state.callFunction(vFun, *(e2->maybeThunk(state, env)), v, pos); -} - - -void EvalState::callPrimOp(Value & fun, Value & arg, Value & v, const Pos & pos) -{ - /* Figure out the number of arguments still needed. */ - size_t argsDone = 0; - Value * primOp = &fun; - while (primOp->isPrimOpApp()) { - argsDone++; - primOp = primOp->primOpApp.left; - } - assert(primOp->isPrimOp()); - auto arity = primOp->primOp->arity; - auto argsLeft = arity - argsDone; - - if (argsLeft == 1) { - /* We have all the arguments, so call the primop. */ - - /* Put all the arguments in an array. */ - Value * vArgs[arity]; - auto n = arity - 1; - vArgs[n--] = &arg; - for (Value * arg = &fun; arg->isPrimOpApp(); arg = arg->primOpApp.left) - vArgs[n--] = arg->primOpApp.right; - - /* And call the primop. */ - nrPrimOpCalls++; - if (countCalls) primOpCalls[primOp->primOp->name]++; - primOp->primOp->fun(*this, pos, vArgs, v); - } else { - Value * fun2 = allocValue(); - *fun2 = fun; - v.mkPrimOpApp(fun2, &arg); - } -} - -void EvalState::callFunction(Value & fun, Value & arg, Value & v, const Pos & pos) +void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value & vRes, const Pos & pos) { auto trace = evalSettings.traceFunctionCalls ? std::make_unique(pos) : nullptr; forceValue(fun, pos); - if (fun.isPrimOp() || fun.isPrimOpApp()) { - callPrimOp(fun, arg, v, pos); - return; - } + Value vCur(fun); - if (fun.type() == nAttrs) { - auto found = fun.attrs->find(sFunctor); - if (found != fun.attrs->end()) { - /* fun may be allocated on the stack of the calling function, - * but for functors we may keep a reference, so heap-allocate - * a copy and use that instead. - */ - auto & fun2 = *allocValue(); - fun2 = fun; - /* !!! Should we use the attr pos here? */ - Value v2; - callFunction(*found->value, fun2, v2, pos); - return callFunction(v2, arg, v, pos); - } - } + auto makeAppChain = [&]() + { + vRes = vCur; + for (size_t i = 0; i < nrArgs; ++i) { + auto fun2 = allocValue(); + *fun2 = vRes; + vRes.mkPrimOpApp(fun2, args[i]); + } + }; - if (!fun.isLambda()) - throwTypeError(pos, "attempt to call something which is not a function but %1%", fun); + while (nrArgs > 0) { - ExprLambda & lambda(*fun.lambda.fun); + if (vCur.isLambda()) { - auto size = - (lambda.arg.empty() ? 0 : 1) + - (lambda.hasFormals() ? lambda.formals->formals.size() : 0); - Env & env2(allocEnv(size)); - env2.up = fun.lambda.env; + ExprLambda & lambda(*vCur.lambda.fun); - size_t displ = 0; + auto size = + (lambda.arg.empty() ? 0 : 1) + + (lambda.hasFormals() ? lambda.formals->formals.size() : 0); + Env & env2(allocEnv(size)); + env2.up = vCur.lambda.env; - if (!lambda.hasFormals()) - env2.values[displ++] = &arg; + size_t displ = 0; - else { - forceAttrs(arg, pos); + if (!lambda.hasFormals()) + env2.values[displ++] = args[0]; - if (!lambda.arg.empty()) - env2.values[displ++] = &arg; + else { + forceAttrs(*args[0], pos); - /* For each formal argument, get the actual argument. If - there is no matching actual argument but the formal - argument has a default, use the default. */ - size_t attrsUsed = 0; - for (auto & i : lambda.formals->formals) { - Bindings::iterator j = arg.attrs->find(i.name); - if (j == arg.attrs->end()) { - if (!i.def) throwTypeError(pos, "%1% called without required argument '%2%'", - lambda, i.name); - env2.values[displ++] = i.def->maybeThunk(*this, env2); + if (!lambda.arg.empty()) + env2.values[displ++] = args[0]; + + /* For each formal argument, get the actual argument. If + there is no matching actual argument but the formal + argument has a default, use the default. */ + size_t attrsUsed = 0; + for (auto & i : lambda.formals->formals) { + auto j = args[0]->attrs->get(i.name); + if (!j) { + if (!i.def) throwTypeError(pos, "%1% called without required argument '%2%'", + lambda, i.name); + env2.values[displ++] = i.def->maybeThunk(*this, env2); + } else { + attrsUsed++; + env2.values[displ++] = j->value; + } + } + + /* Check that each actual argument is listed as a formal + argument (unless the attribute match specifies a `...'). */ + if (!lambda.formals->ellipsis && attrsUsed != args[0]->attrs->size()) { + /* Nope, so show the first unexpected argument to the + user. */ + for (auto & i : *args[0]->attrs) + if (lambda.formals->argNames.find(i.name) == lambda.formals->argNames.end()) + throwTypeError(pos, "%1% called with unexpected argument '%2%'", lambda, i.name); + abort(); // can't happen + } + } + + nrFunctionCalls++; + if (countCalls) incrFunctionCall(&lambda); + + /* Evaluate the body. */ + try { + lambda.body->eval(*this, env2, vCur); + } catch (Error & e) { + if (loggerSettings.showTrace.get()) { + addErrorTrace(e, lambda.pos, "while evaluating %s", + (lambda.name.set() + ? "'" + (string) lambda.name + "'" + : "anonymous lambda")); + addErrorTrace(e, pos, "from call site%s", ""); + } + throw; + } + + nrArgs--; + args += 1; + } + + else if (vCur.isPrimOp()) { + + size_t argsLeft = vCur.primOp->arity; + + if (nrArgs < argsLeft) { + /* We don't have enough arguments, so create a tPrimOpApp chain. */ + makeAppChain(); + return; } else { - attrsUsed++; - env2.values[displ++] = j->value; + /* We have all the arguments, so call the primop. */ + nrPrimOpCalls++; + if (countCalls) primOpCalls[vCur.primOp->name]++; + vCur.primOp->fun(*this, pos, args, vCur); + + nrArgs -= argsLeft; + args += argsLeft; } } - /* Check that each actual argument is listed as a formal - argument (unless the attribute match specifies a `...'). */ - if (!lambda.formals->ellipsis && attrsUsed != arg.attrs->size()) { - /* Nope, so show the first unexpected argument to the - user. */ - for (auto & i : *arg.attrs) - if (lambda.formals->argNames.find(i.name) == lambda.formals->argNames.end()) - throwTypeError(pos, "%1% called with unexpected argument '%2%'", lambda, i.name); - abort(); // can't happen + else if (vCur.isPrimOpApp()) { + /* Figure out the number of arguments still needed. */ + size_t argsDone = 0; + Value * primOp = &vCur; + while (primOp->isPrimOpApp()) { + argsDone++; + primOp = primOp->primOpApp.left; + } + assert(primOp->isPrimOp()); + auto arity = primOp->primOp->arity; + auto argsLeft = arity - argsDone; + + if (nrArgs < argsLeft) { + /* We still don't have enough arguments, so extend the tPrimOpApp chain. */ + makeAppChain(); + return; + } else { + /* We have all the arguments, so call the primop with + the previous and new arguments. */ + + Value * vArgs[arity]; + auto n = argsDone; + for (Value * arg = &vCur; arg->isPrimOpApp(); arg = arg->primOpApp.left) + vArgs[--n] = arg->primOpApp.right; + + for (size_t i = 0; i < argsLeft; ++i) + vArgs[argsDone + i] = args[i]; + + nrPrimOpCalls++; + if (countCalls) primOpCalls[primOp->primOp->name]++; + primOp->primOp->fun(*this, pos, vArgs, vCur); + + nrArgs -= argsLeft; + args += argsLeft; + } } + + else if (vCur.type() == nAttrs) { + if (auto functor = vCur.attrs->get(sFunctor)) { + /* 'vCur" may be allocated on the stack of the calling + function, but for functors we may keep a reference, + so heap-allocate a copy and use that instead. */ + Value * args2[] = {allocValue()}; + *args2[0] = vCur; + /* !!! Should we use the attr pos here? */ + callFunction(*functor->value, 1, args2, vCur, pos); + } + } + + else + throwTypeError(pos, "attempt to call something which is not a function but %1%", vCur); } - nrFunctionCalls++; - if (countCalls) incrFunctionCall(&lambda); + vRes = vCur; +} - /* Evaluate the body. This is conditional on showTrace, because - catching exceptions makes this function not tail-recursive. */ - if (loggerSettings.showTrace.get()) - try { - lambda.body->eval(*this, env2, v); - } catch (Error & e) { - addErrorTrace(e, lambda.pos, "while evaluating %s", - (lambda.name.set() - ? "'" + (string) lambda.name + "'" - : "anonymous lambda")); - addErrorTrace(e, pos, "from call site%s", ""); - throw; - } - else - fun.lambda.fun->body->eval(*this, env2, v); + +void ExprCall::eval(EvalState & state, Env & env, Value & v) +{ + Value vFun; + fun->eval(state, env, vFun); + + Value * vArgs[args.size()]; + for (size_t i = 0; i < args.size(); ++i) + vArgs[i] = args[i]->maybeThunk(state, env); + + state.callFunction(vFun, args.size(), vArgs, v, pos); } diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh index 69119599a..f87dcdd8e 100644 --- a/src/libexpr/eval.hh +++ b/src/libexpr/eval.hh @@ -277,6 +277,8 @@ private: Value * addConstant(const string & name, Value & v); + constexpr static size_t maxPrimOpArity = 3; + Value * addPrimOp(const string & name, size_t arity, PrimOpFun primOp); @@ -316,8 +318,14 @@ public: bool isFunctor(Value & fun); - void callFunction(Value & fun, Value & arg, Value & v, const Pos & pos); - void callPrimOp(Value & fun, Value & arg, Value & v, const Pos & pos); + // FIXME: use std::span + void callFunction(Value & fun, size_t nrArgs, Value * * args, Value & vRes, const Pos & pos); + + void callFunction(Value & fun, Value & arg, Value & vRes, const Pos & pos) + { + Value * args[] = {&arg}; + callFunction(fun, 1, args, vRes, pos); + } /* Automatically call a function for which each argument has a default value or has a binding in the `args' map. */ diff --git a/src/libexpr/lexer.l b/src/libexpr/lexer.l index 51593eccd..c18877e29 100644 --- a/src/libexpr/lexer.l +++ b/src/libexpr/lexer.l @@ -64,6 +64,7 @@ static void adjustLoc(YYLTYPE * loc, const char * s, size_t len) } +// FIXME: optimize static Expr * unescapeStr(SymbolTable & symbols, const char * s, size_t length) { string t; diff --git a/src/libexpr/nixexpr.cc b/src/libexpr/nixexpr.cc index 95a353a40..372e323bc 100644 --- a/src/libexpr/nixexpr.cc +++ b/src/libexpr/nixexpr.cc @@ -143,6 +143,16 @@ void ExprLambda::show(std::ostream & str) const str << ": " << *body << ")"; } +void ExprCall::show(std::ostream & str) const +{ + str << '(' << *fun; + for (auto e : args) { + str << ' '; + str << *e; + } + str << ')'; +} + void ExprLet::show(std::ostream & str) const { str << "(let "; @@ -366,6 +376,13 @@ void ExprLambda::bindVars(const StaticEnv & env) body->bindVars(newEnv); } +void ExprCall::bindVars(const StaticEnv & env) +{ + fun->bindVars(env); + for (auto e : args) + e->bindVars(env); +} + void ExprLet::bindVars(const StaticEnv & env) { StaticEnv newEnv(false, &env, attrs->attrs.size()); @@ -461,5 +478,4 @@ size_t SymbolTable::totalSize() const return n; } - } diff --git a/src/libexpr/nixexpr.hh b/src/libexpr/nixexpr.hh index 3bfa5e0d3..fe12890e9 100644 --- a/src/libexpr/nixexpr.hh +++ b/src/libexpr/nixexpr.hh @@ -248,6 +248,17 @@ struct ExprLambda : Expr COMMON_METHODS }; +struct ExprCall : Expr +{ + Expr * fun; + std::vector args; + Pos pos; + ExprCall(const Pos & pos, Expr * fun, std::vector && args) + : fun(fun), args(args), pos(pos) + { } + COMMON_METHODS +}; + struct ExprLet : Expr { ExprAttrs * attrs; @@ -306,7 +317,6 @@ struct ExprOpNot : Expr void eval(EvalState & state, Env & env, Value & v); \ }; -MakeBinOp(ExprApp, "") MakeBinOp(ExprOpEq, "==") MakeBinOp(ExprOpNEq, "!=") MakeBinOp(ExprOpAnd, "&&") diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y index 5d0f05206..2e8a04143 100644 --- a/src/libexpr/parser.y +++ b/src/libexpr/parser.y @@ -41,6 +41,12 @@ namespace nix { { }; }; + // Helper to prevent an expensive dynamic_cast call in expr_app. + struct App + { + Expr * e; + bool isCall; + }; } #define YY_DECL int yylex \ @@ -280,10 +286,12 @@ void yyerror(YYLTYPE * loc, yyscan_t scanner, ParseData * data, const char * err char * uri; std::vector * attrNames; std::vector * string_parts; + nix::App app; // bool == whether this is an ExprCall } %type start expr expr_function expr_if expr_op -%type expr_app expr_select expr_simple +%type expr_select expr_simple +%type expr_app %type expr_list %type binds %type formals @@ -353,13 +361,13 @@ expr_if expr_op : '!' expr_op %prec NOT { $$ = new ExprOpNot($2); } - | '-' expr_op %prec NEGATE { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__sub")), new ExprInt(0)), $2); } + | '-' expr_op %prec NEGATE { $$ = new ExprCall(CUR_POS, new ExprVar(data->symbols.create("__sub")), {new ExprInt(0), $2}); } | expr_op EQ expr_op { $$ = new ExprOpEq($1, $3); } | expr_op NEQ expr_op { $$ = new ExprOpNEq($1, $3); } - | expr_op '<' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__lessThan")), $1), $3); } - | expr_op LEQ expr_op { $$ = new ExprOpNot(new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__lessThan")), $3), $1)); } - | expr_op '>' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__lessThan")), $3), $1); } - | expr_op GEQ expr_op { $$ = new ExprOpNot(new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__lessThan")), $1), $3)); } + | expr_op '<' expr_op { $$ = new ExprCall(CUR_POS, new ExprVar(data->symbols.create("__lessThan")), {$1, $3}); } + | expr_op LEQ expr_op { $$ = new ExprOpNot(new ExprCall(CUR_POS, new ExprVar(data->symbols.create("__lessThan")), {$3, $1})); } + | expr_op '>' expr_op { $$ = new ExprCall(CUR_POS, new ExprVar(data->symbols.create("__lessThan")), {$3, $1}); } + | expr_op GEQ expr_op { $$ = new ExprOpNot(new ExprCall(CUR_POS, new ExprVar(data->symbols.create("__lessThan")), {$1, $3})); } | expr_op AND expr_op { $$ = new ExprOpAnd(CUR_POS, $1, $3); } | expr_op OR expr_op { $$ = new ExprOpOr(CUR_POS, $1, $3); } | expr_op IMPL expr_op { $$ = new ExprOpImpl(CUR_POS, $1, $3); } @@ -367,17 +375,24 @@ expr_op | expr_op '?' attrpath { $$ = new ExprOpHasAttr($1, *$3); } | expr_op '+' expr_op { $$ = new ExprConcatStrings(CUR_POS, false, new vector({$1, $3})); } - | expr_op '-' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__sub")), $1), $3); } - | expr_op '*' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__mul")), $1), $3); } - | expr_op '/' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__div")), $1), $3); } + | expr_op '-' expr_op { $$ = new ExprCall(CUR_POS, new ExprVar(data->symbols.create("__sub")), {$1, $3}); } + | expr_op '*' expr_op { $$ = new ExprCall(CUR_POS, new ExprVar(data->symbols.create("__mul")), {$1, $3}); } + | expr_op '/' expr_op { $$ = new ExprCall(CUR_POS, new ExprVar(data->symbols.create("__div")), {$1, $3}); } | expr_op CONCAT expr_op { $$ = new ExprOpConcatLists(CUR_POS, $1, $3); } - | expr_app + | expr_app { $$ = $1.e; } ; expr_app - : expr_app expr_select - { $$ = new ExprApp(CUR_POS, $1, $2); } - | expr_select { $$ = $1; } + : expr_app expr_select { + if ($1.isCall) { + ((ExprCall *) $1.e)->args.push_back($2); + $$ = $1; + } else { + $$.e = new ExprCall(CUR_POS, $1.e, {$2}); + $$.isCall = true; + } + } + | expr_select { $$.e = $1; $$.isCall = false; } ; expr_select @@ -388,7 +403,7 @@ expr_select | /* Backwards compatibility: because Nixpkgs has a rarely used function named ‘or’, allow stuff like ‘map or [...]’. */ expr_simple OR_KW - { $$ = new ExprApp(CUR_POS, $1, new ExprVar(CUR_POS, data->symbols.create("or"))); } + { $$ = new ExprCall(CUR_POS, $1, {new ExprVar(CUR_POS, data->symbols.create("or"))}); } | expr_simple { $$ = $1; } ; @@ -412,10 +427,10 @@ expr_simple } | SPATH { string path($1 + 1, strlen($1) - 2); - $$ = new ExprApp(CUR_POS, - new ExprApp(new ExprVar(data->symbols.create("__findFile")), - new ExprVar(data->symbols.create("__nixPath"))), - new ExprString(data->symbols.create(path))); + $$ = new ExprCall(CUR_POS, + new ExprVar(data->symbols.create("__findFile")), + {new ExprVar(data->symbols.create("__nixPath")), + new ExprString(data->symbols.create(path))}); } | URI { static bool noURLLiterals = settings.isExperimentalFeatureEnabled(Xp::NoUrlLiterals);