diff options
Diffstat (limited to 'src/libexpr/eval.cc')
-rw-r--r-- | src/libexpr/eval.cc | 690 |
1 files changed, 303 insertions, 387 deletions
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 76a10b9f8..277cbb5f9 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -45,7 +45,7 @@ static char * allocString(size_t size) #if HAVE_BOEHMGC t = (char *) GC_MALLOC_ATOMIC(size); #else - t = malloc(size); + t = (char *) malloc(size); #endif if (!t) throw std::bad_alloc(); return t; @@ -67,22 +67,19 @@ static char * dupString(const char * s) // When there's no need to write to the string, we can optimize away empty // string allocations. -// This function handles makeImmutableStringWithLen(null, 0) by returning the -// empty string. -static const char * makeImmutableStringWithLen(const char * s, size_t size) +// This function handles makeImmutableString(std::string_view()) by returning +// the empty string. +static const char * makeImmutableString(std::string_view s) { + const size_t size = s.size(); if (size == 0) return ""; auto t = allocString(size + 1); - memcpy(t, s, size); - t[size] = 0; + memcpy(t, s.data(), size); + t[size] = '\0'; return t; } -static inline const char * makeImmutableString(std::string_view s) { - return makeImmutableStringWithLen(s.data(), s.size()); -} - RootValue allocRootValue(Value * v) { @@ -321,7 +318,7 @@ static Symbol getName(const AttrName & name, EvalState & state, Env & env) } else { Value nameValue; name.expr->eval(state, env, nameValue); - state.forceStringNoCtx(nameValue); + state.forceStringNoCtx(nameValue, noPos, "while evaluating an attribute name"); return state.symbols.create(nameValue.string.s); } } @@ -402,7 +399,8 @@ static Strings parseNixPath(const std::string & s) } if (*p == ':') { - if (isUri(std::string(start2, s.end()))) { + auto prefix = std::string(start2, s.end()); + if (EvalSettings::isPseudoUrl(prefix) || hasPrefix(prefix, "flake:")) { ++p; while (p != s.end() && *p != ':') ++p; } @@ -416,6 +414,44 @@ static Strings parseNixPath(const std::string & s) return res; } +ErrorBuilder & ErrorBuilder::atPos(PosIdx pos) +{ + info.errPos = state.positions[pos]; + return *this; +} + +ErrorBuilder & ErrorBuilder::withTrace(PosIdx pos, const std::string_view text) +{ + info.traces.push_front(Trace{ .pos = state.positions[pos], .hint = hintformat(std::string(text)), .frame = false }); + return *this; +} + +ErrorBuilder & ErrorBuilder::withFrameTrace(PosIdx pos, const std::string_view text) +{ + info.traces.push_front(Trace{ .pos = state.positions[pos], .hint = hintformat(std::string(text)), .frame = true }); + return *this; +} + +ErrorBuilder & ErrorBuilder::withSuggestions(Suggestions & s) +{ + info.suggestions = s; + return *this; +} + +ErrorBuilder & ErrorBuilder::withFrame(const Env & env, const Expr & expr) +{ + // NOTE: This is abusing side-effects. + // TODO: check compatibility with nested debugger calls. + state.debugTraces.push_front(DebugTrace { + .pos = nullptr, + .expr = expr, + .env = env, + .hint = hintformat("Fake frame for debugging purposes"), + .isError = true + }); + return *this; +} + EvalState::EvalState( const Strings & _searchPath, @@ -470,9 +506,6 @@ EvalState::EvalState( #if HAVE_BOEHMGC , valueAllocCache(std::allocate_shared<void *>(traceable_allocator<void *>(), nullptr)) , env1AllocCache(std::allocate_shared<void *>(traceable_allocator<void *>(), nullptr)) -#else - , valueAllocCache(std::make_shared<void *>(nullptr)) - , env1AllocCache(std::make_shared<void *>(nullptr)) #endif , baseEnv(allocEnv(128)) , staticBaseEnv{std::make_shared<StaticEnv>(false, nullptr)} @@ -651,25 +684,7 @@ void EvalState::addConstant(const std::string & name, Value * v) Value * EvalState::addPrimOp(const std::string & name, size_t arity, PrimOpFun primOp) { - auto name2 = name.substr(0, 2) == "__" ? name.substr(2) : name; - auto sym = symbols.create(name2); - - /* Hack to make constants lazy: turn them into a application of - the primop to a dummy value. */ - if (arity == 0) { - auto vPrimOp = allocValue(); - vPrimOp->mkPrimOp(new PrimOp { .fun = primOp, .arity = 1, .name = name2 }); - Value v; - v.mkApp(vPrimOp, vPrimOp); - return addConstant(name, v); - } - - Value * v = allocValue(); - v->mkPrimOp(new PrimOp { .fun = primOp, .arity = arity, .name = name2 }); - staticBaseEnv->vars.emplace_back(symbols.create(name), baseEnvDispl); - baseEnv.values[baseEnvDispl++] = v; - baseEnv.values[0]->attrs->push_back(Attr(sym, v)); - return v; + return addPrimOp(PrimOp { .fun = primOp, .arity = arity, .name = name }); } @@ -822,7 +837,7 @@ void EvalState::runDebugRepl(const Error * error, const Env & env, const Expr & ? std::make_unique<DebugTraceStacker>( *this, DebugTrace { - .pos = error->info().errPos ? *error->info().errPos : positions[expr.getPos()], + .pos = error->info().errPos ? error->info().errPos : static_cast<std::shared_ptr<AbstractPos>>(positions[expr.getPos()]), .expr = expr, .env = env, .hint = error->info().msg, @@ -847,189 +862,27 @@ void EvalState::runDebugRepl(const Error * error, const Env & env, const Expr & } } -/* Every "format" object (even temporary) takes up a few hundred bytes - of stack space, which is a real killer in the recursive - evaluator. So here are some helper functions for throwing - exceptions. */ -void EvalState::throwEvalError(const PosIdx pos, const char * s, Env & env, Expr & expr) -{ - debugThrow(EvalError({ - .msg = hintfmt(s), - .errPos = positions[pos] - }), env, expr); -} - -void EvalState::throwEvalError(const PosIdx pos, const char * s) -{ - debugThrowLastTrace(EvalError({ - .msg = hintfmt(s), - .errPos = positions[pos] - })); -} - -void EvalState::throwEvalError(const char * s, const std::string & s2) -{ - debugThrowLastTrace(EvalError(s, s2)); -} - -void EvalState::throwEvalError(const PosIdx pos, const Suggestions & suggestions, const char * s, - const std::string & s2, Env & env, Expr & expr) -{ - debugThrow(EvalError(ErrorInfo{ - .msg = hintfmt(s, s2), - .errPos = positions[pos], - .suggestions = suggestions, - }), env, expr); -} - -void EvalState::throwEvalError(const PosIdx pos, const char * s, const std::string & s2) -{ - debugThrowLastTrace(EvalError({ - .msg = hintfmt(s, s2), - .errPos = positions[pos] - })); -} - -void EvalState::throwEvalError(const PosIdx pos, const char * s, const std::string & s2, Env & env, Expr & expr) -{ - debugThrow(EvalError({ - .msg = hintfmt(s, s2), - .errPos = positions[pos] - }), env, expr); -} - -void EvalState::throwEvalError(const char * s, const std::string & s2, - const std::string & s3) -{ - debugThrowLastTrace(EvalError({ - .msg = hintfmt(s, s2, s3), - .errPos = positions[noPos] - })); -} - -void EvalState::throwEvalError(const PosIdx pos, const char * s, const std::string & s2, - const std::string & s3) -{ - debugThrowLastTrace(EvalError({ - .msg = hintfmt(s, s2, s3), - .errPos = positions[pos] - })); -} - -void EvalState::throwEvalError(const PosIdx pos, const char * s, const std::string & s2, - const std::string & s3, Env & env, Expr & expr) -{ - debugThrow(EvalError({ - .msg = hintfmt(s, s2, s3), - .errPos = positions[pos] - }), env, expr); -} - -void EvalState::throwEvalError(const PosIdx p1, const char * s, const Symbol sym, const PosIdx p2, Env & env, Expr & expr) -{ - // p1 is where the error occurred; p2 is a position mentioned in the message. - debugThrow(EvalError({ - .msg = hintfmt(s, symbols[sym], positions[p2]), - .errPos = positions[p1] - }), env, expr); -} - -void EvalState::throwTypeError(const PosIdx pos, const char * s, const Value & v) -{ - debugThrowLastTrace(TypeError({ - .msg = hintfmt(s, showType(v)), - .errPos = positions[pos] - })); -} - -void EvalState::throwTypeError(const PosIdx pos, const char * s, const Value & v, Env & env, Expr & expr) -{ - debugThrow(TypeError({ - .msg = hintfmt(s, showType(v)), - .errPos = positions[pos] - }), env, expr); -} - -void EvalState::throwTypeError(const PosIdx pos, const char * s) -{ - debugThrowLastTrace(TypeError({ - .msg = hintfmt(s), - .errPos = positions[pos] - })); -} - -void EvalState::throwTypeError(const PosIdx pos, const char * s, const ExprLambda & fun, - const Symbol s2, Env & env, Expr &expr) -{ - debugThrow(TypeError({ - .msg = hintfmt(s, fun.showNamePos(*this), symbols[s2]), - .errPos = positions[pos] - }), env, expr); -} - -void EvalState::throwTypeError(const PosIdx pos, const Suggestions & suggestions, const char * s, - const ExprLambda & fun, const Symbol s2, Env & env, Expr &expr) -{ - debugThrow(TypeError(ErrorInfo { - .msg = hintfmt(s, fun.showNamePos(*this), symbols[s2]), - .errPos = positions[pos], - .suggestions = suggestions, - }), env, expr); -} - -void EvalState::throwTypeError(const char * s, const Value & v, Env & env, Expr &expr) -{ - debugThrow(TypeError({ - .msg = hintfmt(s, showType(v)), - .errPos = positions[expr.getPos()], - }), env, expr); -} - -void EvalState::throwAssertionError(const PosIdx pos, const char * s, const std::string & s1, Env & env, Expr &expr) -{ - debugThrow(AssertionError({ - .msg = hintfmt(s, s1), - .errPos = positions[pos] - }), env, expr); -} - -void EvalState::throwUndefinedVarError(const PosIdx pos, const char * s, const std::string & s1, Env & env, Expr &expr) -{ - debugThrow(UndefinedVarError({ - .msg = hintfmt(s, s1), - .errPos = positions[pos] - }), env, expr); -} - -void EvalState::throwMissingArgumentError(const PosIdx pos, const char * s, const std::string & s1, Env & env, Expr &expr) -{ - debugThrow(MissingArgumentError({ - .msg = hintfmt(s, s1), - .errPos = positions[pos] - }), env, expr); -} - void EvalState::addErrorTrace(Error & e, const char * s, const std::string & s2) const { - e.addTrace(std::nullopt, s, s2); + e.addTrace(nullptr, s, s2); } -void EvalState::addErrorTrace(Error & e, const PosIdx pos, const char * s, const std::string & s2) const +void EvalState::addErrorTrace(Error & e, const PosIdx pos, const char * s, const std::string & s2, bool frame) const { - e.addTrace(positions[pos], s, s2); + e.addTrace(positions[pos], hintfmt(s, s2), frame); } static std::unique_ptr<DebugTraceStacker> makeDebugTraceStacker( EvalState & state, Expr & expr, Env & env, - std::optional<ErrPos> pos, + std::shared_ptr<AbstractPos> && pos, const char * s, const std::string & s2) { return std::make_unique<DebugTraceStacker>(state, DebugTrace { - .pos = pos, + .pos = std::move(pos), .expr = expr, .env = env, .hint = hintfmt(s, s2), @@ -1093,7 +946,7 @@ inline Value * EvalState::lookupVar(Env * env, const ExprVar & var, bool noEval) if (env->type == Env::HasWithExpr) { if (noEval) return 0; Value * v = allocValue(); - evalAttrs(*env->up, (Expr *) env->values[0], *v); + evalAttrs(*env->up, (Expr *) env->values[0], *v, noPos, "<borked>"); env->values[0] = v; env->type = Env::HasWithAttrs; } @@ -1103,7 +956,7 @@ inline Value * EvalState::lookupVar(Env * env, const ExprVar & var, bool noEval) return j->value; } if (!env->prevWith) - throwUndefinedVarError(var.pos, "undefined variable '%1%'", symbols[var.name], *env, const_cast<ExprVar&>(var)); + error("undefined variable '%1%'", symbols[var.name]).atPos(var.pos).withFrame(*env, var).debugThrow<UndefinedVarError>(); for (size_t l = env->prevWith; l; --l, env = env->up) ; } } @@ -1135,9 +988,9 @@ void EvalState::mkThunk_(Value & v, Expr * expr) void EvalState::mkPos(Value & v, PosIdx p) { auto pos = positions[p]; - if (!pos.file.empty()) { + if (auto path = std::get_if<Path>(&pos.origin)) { auto attrs = buildBindings(3); - attrs.alloc(sFile).mkString(pos.file); + attrs.alloc(sFile).mkString(*path); attrs.alloc(sLine).mkInt(pos.line); attrs.alloc(sColumn).mkInt(pos.column); v.mkAttrs(attrs); @@ -1245,7 +1098,7 @@ void EvalState::cacheFile( *this, *e, this->baseEnv, - e->getPos() ? std::optional(ErrPos(positions[e->getPos()])) : std::nullopt, + e->getPos() ? static_cast<std::shared_ptr<AbstractPos>>(positions[e->getPos()]) : nullptr, "while evaluating the file '%1%':", resolvedPath) : nullptr; @@ -1253,7 +1106,7 @@ void EvalState::cacheFile( // computation. if (mustBeTrivial && !(dynamic_cast<ExprAttrs *>(e))) - throw EvalError("file '%s' must be an attribute set", path); + error("file '%s' must be an attribute set", path).debugThrow<EvalError>(); eval(e, v); } catch (Error & e) { addErrorTrace(e, "while evaluating the file '%1%':", resolvedPath); @@ -1271,31 +1124,31 @@ void EvalState::eval(Expr * e, Value & v) } -inline bool EvalState::evalBool(Env & env, Expr * e) +inline bool EvalState::evalBool(Env & env, Expr * e, const PosIdx pos, std::string_view errorCtx) { - Value v; - e->eval(*this, env, v); - if (v.type() != nBool) - throwTypeError(noPos, "value is %1% while a Boolean was expected", v, env, *e); - return v.boolean; -} - - -inline bool EvalState::evalBool(Env & env, Expr * e, const PosIdx pos) -{ - Value v; - e->eval(*this, env, v); - if (v.type() != nBool) - throwTypeError(pos, "value is %1% while a Boolean was expected", v, env, *e); - return v.boolean; + try { + Value v; + e->eval(*this, env, v); + if (v.type() != nBool) + error("value is %1% while a Boolean was expected", showType(v)).withFrame(env, *e).debugThrow<TypeError>(); + return v.boolean; + } catch (Error & e) { + e.addTrace(positions[pos], errorCtx); + throw; + } } -inline void EvalState::evalAttrs(Env & env, Expr * e, Value & v) +inline void EvalState::evalAttrs(Env & env, Expr * e, Value & v, const PosIdx pos, std::string_view errorCtx) { - e->eval(*this, env, v); - if (v.type() != nAttrs) - throwTypeError(noPos, "value is %1% while a set was expected", v, env, *e); + try { + e->eval(*this, env, v); + if (v.type() != nAttrs) + error("value is %1% while a set was expected", showType(v)).withFrame(env, *e).debugThrow<TypeError>(); + } catch (Error & e) { + e.addTrace(positions[pos], errorCtx); + throw; + } } @@ -1368,7 +1221,7 @@ void ExprAttrs::eval(EvalState & state, Env & env, Value & v) Hence we need __overrides.) */ if (hasOverrides) { Value * vOverrides = (*v.attrs)[overrides->second.displ].value; - state.forceAttrs(*vOverrides, [&]() { return vOverrides->determinePos(noPos); }); + state.forceAttrs(*vOverrides, [&]() { return vOverrides->determinePos(noPos); }, "while evaluating the `__overrides` attribute"); Bindings * newBnds = state.allocBindings(v.attrs->capacity() + vOverrides->attrs->size()); for (auto & i : *v.attrs) newBnds->push_back(i); @@ -1396,11 +1249,11 @@ void ExprAttrs::eval(EvalState & state, Env & env, Value & v) state.forceValue(nameVal, i.pos); if (nameVal.type() == nNull) continue; - state.forceStringNoCtx(nameVal); + state.forceStringNoCtx(nameVal, i.pos, "while evaluating the name of a dynamic attribute"); auto nameSym = state.symbols.create(nameVal.string.s); Bindings::iterator j = v.attrs->find(nameSym); if (j != v.attrs->end()) - state.throwEvalError(i.pos, "dynamic attribute '%1%' already defined at %2%", nameSym, j->pos, env, *this); + state.error("dynamic attribute '%1%' already defined at %2%", state.symbols[nameSym], state.positions[j->pos]).atPos(i.pos).withFrame(env, *this).debugThrow<EvalError>(); i.valueExpr->setName(nameSym); /* Keep sorted order so find can catch duplicates */ @@ -1497,15 +1350,14 @@ void ExprSelect::eval(EvalState & state, Env & env, Value & v) return; } } else { - state.forceAttrs(*vAttrs, pos); + state.forceAttrs(*vAttrs, pos, "while selecting an attribute"); if ((j = vAttrs->attrs->find(name)) == vAttrs->attrs->end()) { std::set<std::string> allAttrNames; for (auto & attr : *vAttrs->attrs) allAttrNames.insert(state.symbols[attr.name]); - state.throwEvalError( - pos, - Suggestions::bestMatches(allAttrNames, state.symbols[name]), - "attribute '%1%' missing", state.symbols[name], env, *this); + auto suggestions = Suggestions::bestMatches(allAttrNames, state.symbols[name]); + state.error("attribute '%1%' missing", state.symbols[name]) + .atPos(pos).withSuggestions(suggestions).withFrame(env, *this).debugThrow<EvalError>(); } } vAttrs = j->value; @@ -1516,10 +1368,13 @@ void ExprSelect::eval(EvalState & state, Env & env, Value & v) state.forceValue(*vAttrs, (pos2 ? pos2 : this->pos ) ); } catch (Error & e) { - auto pos2r = state.positions[pos2]; - if (pos2 && pos2r.file != state.derivationNixPath) - state.addErrorTrace(e, pos2, "while evaluating the attribute '%1%'", - showAttrPath(state, env, attrPath)); + if (pos2) { + auto pos2r = state.positions[pos2]; + auto origin = std::get_if<Path>(&pos2r.origin); + if (!(origin && *origin == state.derivationNixPath)) + state.addErrorTrace(e, pos2, "while evaluating the attribute '%1%'", + showAttrPath(state, env, attrPath)); + } throw; } @@ -1597,7 +1452,12 @@ void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value & if (!lambda.hasFormals()) env2.values[displ++] = args[0]; else { - forceAttrs(*args[0], pos); + try { + forceAttrs(*args[0], lambda.pos, "while evaluating the value passed for the lambda argument"); + } catch (Error & e) { + if (pos) e.addTrace(positions[pos], "from call site"); + throw; + } if (lambda.arg) env2.values[displ++] = args[0]; @@ -1609,8 +1469,15 @@ void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value & 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, *fun.lambda.env, lambda); + if (!i.def) { + error("function '%1%' called without required argument '%2%'", + (lambda.name ? std::string(symbols[lambda.name]) : "anonymous lambda"), + symbols[i.name]) + .atPos(lambda.pos) + .withTrace(pos, "from call site") + .withFrame(*fun.lambda.env, lambda) + .debugThrow<TypeError>(); + } env2.values[displ++] = i.def->maybeThunk(*this, env2); } else { attrsUsed++; @@ -1628,11 +1495,15 @@ void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value & std::set<std::string> formalNames; for (auto & formal : lambda.formals->formals) formalNames.insert(symbols[formal.name]); - throwTypeError( - pos, - Suggestions::bestMatches(formalNames, symbols[i.name]), - "%1% called with unexpected argument '%2%'", - lambda, i.name, *fun.lambda.env, lambda); + auto suggestions = Suggestions::bestMatches(formalNames, symbols[i.name]); + error("function '%1%' called with unexpected argument '%2%'", + (lambda.name ? std::string(symbols[lambda.name]) : "anonymous lambda"), + symbols[i.name]) + .atPos(lambda.pos) + .withTrace(pos, "from call site") + .withSuggestions(suggestions) + .withFrame(*fun.lambda.env, lambda) + .debugThrow<TypeError>(); } abort(); // can't happen } @@ -1655,11 +1526,15 @@ void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value & lambda.body->eval(*this, env2, vCur); } catch (Error & e) { if (loggerSettings.showTrace.get()) { - addErrorTrace(e, lambda.pos, "while calling %s", - (lambda.name - ? concatStrings("'", symbols[lambda.name], "'") - : "anonymous lambda")); - addErrorTrace(e, pos, "from call site%s", ""); + addErrorTrace( + e, + lambda.pos, + "while calling %s", + lambda.name + ? concatStrings("'", symbols[lambda.name], "'") + : "anonymous lambda", + true); + if (pos) addErrorTrace(e, pos, "from call site%s", "", true); } throw; } @@ -1678,9 +1553,17 @@ void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value & return; } else { /* We have all the arguments, so call the primop. */ + auto name = vCur.primOp->name; + nrPrimOpCalls++; - if (countCalls) primOpCalls[vCur.primOp->name]++; - vCur.primOp->fun(*this, pos, args, vCur); + if (countCalls) primOpCalls[name]++; + + try { + vCur.primOp->fun(*this, noPos, args, vCur); + } catch (Error & e) { + addErrorTrace(e, pos, "while calling the '%1%' builtin", name); + throw; + } nrArgs -= argsLeft; args += argsLeft; @@ -1715,9 +1598,20 @@ void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value & for (size_t i = 0; i < argsLeft; ++i) vArgs[argsDone + i] = args[i]; + auto name = primOp->primOp->name; nrPrimOpCalls++; - if (countCalls) primOpCalls[primOp->primOp->name]++; - primOp->primOp->fun(*this, pos, vArgs, vCur); + if (countCalls) primOpCalls[name]++; + + try { + // TODO: + // 1. Unify this and above code. Heavily redundant. + // 2. Create a fake env (arg1, arg2, etc.) and a fake expr (arg1: arg2: etc: builtins.name arg1 arg2 etc) + // so the debugger allows to inspect the wrong parameters passed to the builtin. + primOp->primOp->fun(*this, noPos, vArgs, vCur); + } catch (Error & e) { + addErrorTrace(e, pos, "while calling the '%1%' builtin", name); + throw; + } nrArgs -= argsLeft; args += argsLeft; @@ -1730,14 +1624,18 @@ void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value & heap-allocate a copy and use that instead. */ Value * args2[] = {allocValue(), args[0]}; *args2[0] = vCur; - /* !!! Should we use the attr pos here? */ - callFunction(*functor->value, 2, args2, vCur, pos); + try { + callFunction(*functor->value, 2, args2, vCur, functor->pos); + } catch (Error & e) { + e.addTrace(positions[pos], "while calling a functor (an attribute set with a '__functor' attribute)"); + throw; + } nrArgs--; args++; } else - throwTypeError(pos, "attempt to call something which is not a function but %1%", vCur); + error("attempt to call something which is not a function but %1%", showType(vCur)).atPos(pos).debugThrow<TypeError>(); } vRes = vCur; @@ -1801,13 +1699,12 @@ void EvalState::autoCallFunction(Bindings & args, Value & fun, Value & res) if (j != args.end()) { attrs.insert(*j); } else if (!i.def) { - throwMissingArgumentError(i.pos, R"(cannot evaluate a function that has an argument without a value ('%1%') - + error(R"(cannot evaluate a function that has an argument without a value ('%1%') Nix attempted to evaluate a function as a top level expression; in this case it must have its arguments supplied either by default values, or passed explicitly with '--arg' or '--argstr'. See -https://nixos.org/manual/nix/stable/expressions/language-constructs.html#functions.)", symbols[i.name], - *fun.lambda.env, *fun.lambda.fun); +https://nixos.org/manual/nix/stable/language/constructs.html#functions.)", symbols[i.name]) + .atPos(i.pos).withFrame(*fun.lambda.env, *fun.lambda.fun).debugThrow<MissingArgumentError>(); } } } @@ -1830,16 +1727,17 @@ void ExprWith::eval(EvalState & state, Env & env, Value & v) void ExprIf::eval(EvalState & state, Env & env, Value & v) { - (state.evalBool(env, cond, pos) ? then : else_)->eval(state, env, v); + // We cheat in the parser, and pass the position of the condition as the position of the if itself. + (state.evalBool(env, cond, pos, "while evaluating a branch condition") ? then : else_)->eval(state, env, v); } void ExprAssert::eval(EvalState & state, Env & env, Value & v) { - if (!state.evalBool(env, cond, pos)) { + if (!state.evalBool(env, cond, pos, "in the condition of the assert statement")) { std::ostringstream out; cond->show(state.symbols, out); - state.throwAssertionError(pos, "assertion '%1%' failed", out.str(), env, *this); + state.error("assertion '%1%' failed", out.str()).atPos(pos).withFrame(env, *this).debugThrow<AssertionError>(); } body->eval(state, env, v); } @@ -1847,7 +1745,7 @@ void ExprAssert::eval(EvalState & state, Env & env, Value & v) void ExprOpNot::eval(EvalState & state, Env & env, Value & v) { - v.mkBool(!state.evalBool(env, e)); + v.mkBool(!state.evalBool(env, e, noPos, "in the argument of the not operator")); // XXX: FIXME: ! } @@ -1855,7 +1753,7 @@ void ExprOpEq::eval(EvalState & state, Env & env, Value & v) { Value v1; e1->eval(state, env, v1); Value v2; e2->eval(state, env, v2); - v.mkBool(state.eqValues(v1, v2)); + v.mkBool(state.eqValues(v1, v2, pos, "while testing two values for equality")); } @@ -1863,33 +1761,33 @@ void ExprOpNEq::eval(EvalState & state, Env & env, Value & v) { Value v1; e1->eval(state, env, v1); Value v2; e2->eval(state, env, v2); - v.mkBool(!state.eqValues(v1, v2)); + v.mkBool(!state.eqValues(v1, v2, pos, "while testing two values for inequality")); } void ExprOpAnd::eval(EvalState & state, Env & env, Value & v) { - v.mkBool(state.evalBool(env, e1, pos) && state.evalBool(env, e2, pos)); + v.mkBool(state.evalBool(env, e1, pos, "in the left operand of the AND (&&) operator") && state.evalBool(env, e2, pos, "in the right operand of the AND (&&) operator")); } void ExprOpOr::eval(EvalState & state, Env & env, Value & v) { - v.mkBool(state.evalBool(env, e1, pos) || state.evalBool(env, e2, pos)); + v.mkBool(state.evalBool(env, e1, pos, "in the left operand of the OR (||) operator") || state.evalBool(env, e2, pos, "in the right operand of the OR (||) operator")); } void ExprOpImpl::eval(EvalState & state, Env & env, Value & v) { - v.mkBool(!state.evalBool(env, e1, pos) || state.evalBool(env, e2, pos)); + v.mkBool(!state.evalBool(env, e1, pos, "in the left operand of the IMPL (->) operator") || state.evalBool(env, e2, pos, "in the right operand of the IMPL (->) operator")); } void ExprOpUpdate::eval(EvalState & state, Env & env, Value & v) { Value v1, v2; - state.evalAttrs(env, e1, v1); - state.evalAttrs(env, e2, v2); + state.evalAttrs(env, e1, v1, pos, "in the left operand of the update (//) operator"); + state.evalAttrs(env, e2, v2, pos, "in the right operand of the update (//) operator"); state.nrOpUpdates++; @@ -1928,18 +1826,18 @@ void ExprOpConcatLists::eval(EvalState & state, Env & env, Value & v) Value v1; e1->eval(state, env, v1); Value v2; e2->eval(state, env, v2); Value * lists[2] = { &v1, &v2 }; - state.concatLists(v, 2, lists, pos); + state.concatLists(v, 2, lists, pos, "while evaluating one of the elements to concatenate"); } -void EvalState::concatLists(Value & v, size_t nrLists, Value * * lists, const PosIdx pos) +void EvalState::concatLists(Value & v, size_t nrLists, Value * * lists, const PosIdx pos, std::string_view errorCtx) { nrListConcats++; Value * nonEmpty = 0; size_t len = 0; for (size_t n = 0; n < nrLists; ++n) { - forceList(*lists[n], pos); + forceList(*lists[n], pos, errorCtx); auto l = lists[n]->listSize(); len += l; if (l) nonEmpty = lists[n]; @@ -2016,20 +1914,20 @@ void ExprConcatStrings::eval(EvalState & state, Env & env, Value & v) nf = n; nf += vTmp.fpoint; } else - state.throwEvalError(i_pos, "cannot add %1% to an integer", showType(vTmp), env, *this); + state.error("cannot add %1% to an integer", showType(vTmp)).atPos(i_pos).withFrame(env, *this).debugThrow<EvalError>(); } else if (firstType == nFloat) { if (vTmp.type() == nInt) { nf += vTmp.integer; } else if (vTmp.type() == nFloat) { nf += vTmp.fpoint; } else - state.throwEvalError(i_pos, "cannot add %1% to a float", showType(vTmp), env, *this); + state.error("cannot add %1% to a float", showType(vTmp)).atPos(i_pos).withFrame(env, *this).debugThrow<EvalError>(); } else { if (s.empty()) s.reserve(es->size()); /* skip canonization of first path, which would only be not canonized in the first place if it's coming from a ./${foo} type path */ - auto part = state.coerceToString(i_pos, vTmp, context, false, firstType == nString, !first); + auto part = state.coerceToString(i_pos, vTmp, context, false, firstType == nString, !first, "while evaluating a path segment"); sSize += part->size(); s.emplace_back(std::move(part)); } @@ -2043,7 +1941,7 @@ void ExprConcatStrings::eval(EvalState & state, Env & env, Value & v) v.mkFloat(nf); else if (firstType == nPath) { if (!context.empty()) - state.throwEvalError(pos, "a string that refers to a store path cannot be appended to a path", env, *this); + state.error("a string that refers to a store path cannot be appended to a path").atPos(pos).withFrame(env, *this).debugThrow<EvalError>(); v.mkPath(canonPath(str())); } else v.mkStringMove(c_str(), context); @@ -2093,33 +1991,47 @@ void EvalState::forceValueDeep(Value & v) } -NixInt EvalState::forceInt(Value & v, const PosIdx pos) +NixInt EvalState::forceInt(Value & v, const PosIdx pos, std::string_view errorCtx) { - forceValue(v, pos); - if (v.type() != nInt) - throwTypeError(pos, "value is %1% while an integer was expected", v); - - return v.integer; + try { + forceValue(v, pos); + if (v.type() != nInt) + error("value is %1% while an integer was expected", showType(v)).debugThrow<TypeError>(); + return v.integer; + } catch (Error & e) { + e.addTrace(positions[pos], errorCtx); + throw; + } } -NixFloat EvalState::forceFloat(Value & v, const PosIdx pos) +NixFloat EvalState::forceFloat(Value & v, const PosIdx pos, std::string_view errorCtx) { - forceValue(v, pos); - if (v.type() == nInt) - return v.integer; - else if (v.type() != nFloat) - throwTypeError(pos, "value is %1% while a float was expected", v); - return v.fpoint; + try { + forceValue(v, pos); + if (v.type() == nInt) + return v.integer; + else if (v.type() != nFloat) + error("value is %1% while a float was expected", showType(v)).debugThrow<TypeError>(); + return v.fpoint; + } catch (Error & e) { + e.addTrace(positions[pos], errorCtx); + throw; + } } -bool EvalState::forceBool(Value & v, const PosIdx pos) +bool EvalState::forceBool(Value & v, const PosIdx pos, std::string_view errorCtx) { - forceValue(v, pos); - if (v.type() != nBool) - throwTypeError(pos, "value is %1% while a Boolean was expected", v); - return v.boolean; + try { + forceValue(v, pos); + if (v.type() != nBool) + error("value is %1% while a Boolean was expected", showType(v)).debugThrow<TypeError>(); + return v.boolean; + } catch (Error & e) { + e.addTrace(positions[pos], errorCtx); + throw; + } } @@ -2129,42 +2041,30 @@ bool EvalState::isFunctor(Value & fun) } -void EvalState::forceFunction(Value & v, const PosIdx pos) -{ - forceValue(v, pos); - if (v.type() != nFunction && !isFunctor(v)) - throwTypeError(pos, "value is %1% while a function was expected", v); -} - - -std::string_view EvalState::forceString(Value & v, const PosIdx pos) +void EvalState::forceFunction(Value & v, const PosIdx pos, std::string_view errorCtx) { - forceValue(v, pos); - if (v.type() != nString) { - throwTypeError(pos, "value is %1% while a string was expected", v); + try { + forceValue(v, pos); + if (v.type() != nFunction && !isFunctor(v)) + error("value is %1% while a function was expected", showType(v)).debugThrow<TypeError>(); + } catch (Error & e) { + e.addTrace(positions[pos], errorCtx); + throw; } - return v.string.s; } -/* Decode a context string ‘!<name>!<path>’ into a pair <path, - name>. */ -NixStringContextElem decodeContext(const Store & store, std::string_view s) +std::string_view EvalState::forceString(Value & v, const PosIdx pos, std::string_view errorCtx) { - if (s.at(0) == '!') { - size_t index = s.find("!", 1); - return { - store.parseStorePath(s.substr(index + 1)), - std::string(s.substr(1, index - 1)), - }; - } else - return { - store.parseStorePath( - s.at(0) == '/' - ? s - : s.substr(1)), - "", - }; + try { + forceValue(v, pos); + if (v.type() != nString) + error("value is %1% while a string was expected", showType(v)).debugThrow<TypeError>(); + return v.string.s; + } catch (Error & e) { + e.addTrace(positions[pos], errorCtx); + throw; + } } @@ -2182,29 +2082,24 @@ NixStringContext Value::getContext(const Store & store) assert(internalType == tString); if (string.context) for (const char * * p = string.context; *p; ++p) - res.push_back(decodeContext(store, *p)); + res.push_back(NixStringContextElem::parse(store, *p)); return res; } -std::string_view EvalState::forceString(Value & v, PathSet & context, const PosIdx pos) +std::string_view EvalState::forceString(Value & v, PathSet & context, const PosIdx pos, std::string_view errorCtx) { - auto s = forceString(v, pos); + auto s = forceString(v, pos, errorCtx); copyContext(v, context); return s; } -std::string_view EvalState::forceStringNoCtx(Value & v, const PosIdx pos) +std::string_view EvalState::forceStringNoCtx(Value & v, const PosIdx pos, std::string_view errorCtx) { - auto s = forceString(v, pos); + auto s = forceString(v, pos, errorCtx); if (v.string.context) { - if (pos) - throwEvalError(pos, "the string '%1%' is not allowed to refer to a store path (such as '%2%')", - v.string.s, v.string.context[0]); - else - throwEvalError("the string '%1%' is not allowed to refer to a store path (such as '%2%')", - v.string.s, v.string.context[0]); + error("the string '%1%' is not allowed to refer to a store path (such as '%2%')", v.string.s, v.string.context[0]).withTrace(pos, errorCtx).debugThrow<EvalError>(); } return s; } @@ -2228,14 +2123,15 @@ std::optional<std::string> EvalState::tryAttrsToString(const PosIdx pos, Value & if (i != v.attrs->end()) { Value v1; callFunction(*i->value, v, v1, pos); - return coerceToString(pos, v1, context, coerceMore, copyToStore).toOwned(); + return coerceToString(pos, v1, context, coerceMore, copyToStore, + "while evaluating the result of the `toString` attribute").toOwned(); } return {}; } BackedStringView EvalState::coerceToString(const PosIdx pos, Value & v, PathSet & context, - bool coerceMore, bool copyToStore, bool canonicalizePath) + bool coerceMore, bool copyToStore, bool canonicalizePath, std::string_view errorCtx) { forceValue(v, pos); @@ -2249,7 +2145,7 @@ BackedStringView EvalState::coerceToString(const PosIdx pos, Value & v, PathSet if (canonicalizePath) path = canonPath(*path); if (copyToStore) - path = copyPathToStore(context, std::move(path).toOwned()); + path = store->printStorePath(copyPathToStore(context, std::move(path).toOwned())); return path; } @@ -2259,12 +2155,12 @@ BackedStringView EvalState::coerceToString(const PosIdx pos, Value & v, PathSet return std::move(*maybeString); auto i = v.attrs->find(sOutPath); if (i == v.attrs->end()) - throwTypeError(pos, "cannot coerce a set to a string"); - return coerceToString(pos, *i->value, context, coerceMore, copyToStore); + error("cannot coerce a set to a string", showType(v)).withTrace(pos, errorCtx).debugThrow<TypeError>(); + return coerceToString(pos, *i->value, context, coerceMore, copyToStore, canonicalizePath, errorCtx); } if (v.type() == nExternal) - return v.external->coerceToString(positions[pos], context, coerceMore, copyToStore); + return v.external->coerceToString(positions[pos], context, coerceMore, copyToStore, errorCtx); if (coerceMore) { /* Note that `false' is represented as an empty string for @@ -2278,7 +2174,13 @@ BackedStringView EvalState::coerceToString(const PosIdx pos, Value & v, PathSet if (v.isList()) { std::string result; for (auto [n, v2] : enumerate(v.listItems())) { - result += *coerceToString(pos, *v2, context, coerceMore, copyToStore); + try { + result += *coerceToString(noPos, *v2, context, coerceMore, copyToStore, canonicalizePath, + "while evaluating one element of the list"); + } catch (Error & e) { + e.addTrace(positions[pos], errorCtx); + throw; + } if (n < v.listSize() - 1 /* !!! not quite correct */ && (!v2->isList() || v2->listSize() != 0)) @@ -2288,56 +2190,53 @@ BackedStringView EvalState::coerceToString(const PosIdx pos, Value & v, PathSet } } - throwTypeError(pos, "cannot coerce %1% to a string", v); + error("cannot coerce %1% to a string", showType(v)).withTrace(pos, errorCtx).debugThrow<TypeError>(); } -std::string EvalState::copyPathToStore(PathSet & context, const Path & path) +StorePath EvalState::copyPathToStore(PathSet & context, const Path & path) { if (nix::isDerivation(path)) - throwEvalError("file names are not allowed to end in '%1%'", drvExtension); - - Path dstPath; - auto i = srcToStore.find(path); - if (i != srcToStore.end()) - dstPath = store->printStorePath(i->second); - else { - auto p = settings.readOnlyMode + error("file names are not allowed to end in '%1%'", drvExtension).debugThrow<EvalError>(); + + auto dstPath = [&]() -> StorePath + { + auto i = srcToStore.find(path); + if (i != srcToStore.end()) return i->second; + + auto dstPath = settings.readOnlyMode ? store->computeStorePathForPath(std::string(baseNameOf(path)), checkSourcePath(path)).first : store->addToStore(std::string(baseNameOf(path)), checkSourcePath(path), FileIngestionMethod::Recursive, htSHA256, defaultPathFilter, repair); - dstPath = store->printStorePath(p); - allowPath(p); - srcToStore.insert_or_assign(path, std::move(p)); - printMsg(lvlChatty, "copied source '%1%' -> '%2%'", path, dstPath); - } + allowPath(dstPath); + srcToStore.insert_or_assign(path, dstPath); + printMsg(lvlChatty, "copied source '%1%' -> '%2%'", path, store->printStorePath(dstPath)); + return dstPath; + }(); - context.insert(dstPath); + context.insert(store->printStorePath(dstPath)); return dstPath; } -Path EvalState::coerceToPath(const PosIdx pos, Value & v, PathSet & context) +Path EvalState::coerceToPath(const PosIdx pos, Value & v, PathSet & context, std::string_view errorCtx) { - auto path = coerceToString(pos, v, context, false, false).toOwned(); + auto path = coerceToString(pos, v, context, false, false, true, errorCtx).toOwned(); if (path == "" || path[0] != '/') - throwEvalError(pos, "string '%1%' doesn't represent an absolute path", path); + error("string '%1%' doesn't represent an absolute path", path).withTrace(pos, errorCtx).debugThrow<EvalError>(); return path; } -StorePath EvalState::coerceToStorePath(const PosIdx pos, Value & v, PathSet & context) +StorePath EvalState::coerceToStorePath(const PosIdx pos, Value & v, PathSet & context, std::string_view errorCtx) { - auto path = coerceToString(pos, v, context, false, false).toOwned(); + auto path = coerceToString(pos, v, context, false, false, true, errorCtx).toOwned(); if (auto storePath = store->maybeParseStorePath(path)) return *storePath; - throw EvalError({ - .msg = hintfmt("path '%1%' is not in the Nix store", path), - .errPos = positions[pos] - }); + error("path '%1%' is not in the Nix store", path).withTrace(pos, errorCtx).debugThrow<EvalError>(); } -bool EvalState::eqValues(Value & v1, Value & v2) +bool EvalState::eqValues(Value & v1, Value & v2, const PosIdx pos, std::string_view errorCtx) { forceValue(v1, noPos); forceValue(v2, noPos); @@ -2357,7 +2256,6 @@ bool EvalState::eqValues(Value & v1, Value & v2) if (v1.type() != v2.type()) return false; switch (v1.type()) { - case nInt: return v1.integer == v2.integer; @@ -2376,7 +2274,7 @@ bool EvalState::eqValues(Value & v1, Value & v2) case nList: if (v1.listSize() != v2.listSize()) return false; for (size_t n = 0; n < v1.listSize(); ++n) - if (!eqValues(*v1.listElems()[n], *v2.listElems()[n])) return false; + if (!eqValues(*v1.listElems()[n], *v2.listElems()[n], pos, errorCtx)) return false; return true; case nAttrs: { @@ -2386,7 +2284,7 @@ bool EvalState::eqValues(Value & v1, Value & v2) Bindings::iterator i = v1.attrs->find(sOutPath); Bindings::iterator j = v2.attrs->find(sOutPath); if (i != v1.attrs->end() && j != v2.attrs->end()) - return eqValues(*i->value, *j->value); + return eqValues(*i->value, *j->value, pos, errorCtx); } if (v1.attrs->size() != v2.attrs->size()) return false; @@ -2394,7 +2292,7 @@ bool EvalState::eqValues(Value & v1, Value & v2) /* Otherwise, compare the attributes one by one. */ Bindings::iterator i, j; for (i = v1.attrs->begin(), j = v2.attrs->begin(); i != v1.attrs->end(); ++i, ++j) - if (i->name != j->name || !eqValues(*i->value, *j->value)) + if (i->name != j->name || !eqValues(*i->value, *j->value, pos, errorCtx)) return false; return true; @@ -2411,9 +2309,7 @@ bool EvalState::eqValues(Value & v1, Value & v2) return v1.fpoint == v2.fpoint; default: - throwEvalError("cannot compare %1% with %2%", - showType(v1), - showType(v2)); + error("cannot compare %1% with %2%", showType(v1), showType(v2)).withTrace(pos, errorCtx).debugThrow<EvalError>(); } } @@ -2496,7 +2392,8 @@ void EvalState::printStats() else obj["name"] = nullptr; if (auto pos = positions[fun->pos]) { - obj["file"] = (std::string_view) pos.file; + if (auto path = std::get_if<Path>(&pos.origin)) + obj["file"] = *path; obj["line"] = pos.line; obj["column"] = pos.column; } @@ -2510,7 +2407,8 @@ void EvalState::printStats() for (auto & i : attrSelects) { json obj = json::object(); if (auto pos = positions[i.first]) { - obj["file"] = (const std::string &) pos.file; + if (auto path = std::get_if<Path>(&pos.origin)) + obj["file"] = *path; obj["line"] = pos.line; obj["column"] = pos.column; } @@ -2535,12 +2433,13 @@ void EvalState::printStats() } -std::string ExternalValueBase::coerceToString(const Pos & pos, PathSet & context, bool copyMore, bool copyToStore) const +std::string ExternalValueBase::coerceToString(const Pos & pos, PathSet & context, bool copyMore, bool copyToStore, std::string_view errorCtx) const { - throw TypeError({ - .msg = hintfmt("cannot coerce %1% to a string", showType()), - .errPos = pos + auto e = TypeError({ + .msg = hintfmt("cannot coerce %1% to a string", showType()) }); + e.addTrace(pos, errorCtx); + throw e; } @@ -2583,6 +2482,23 @@ Strings EvalSettings::getDefaultNixPath() return res; } +bool EvalSettings::isPseudoUrl(std::string_view s) +{ + if (s.compare(0, 8, "channel:") == 0) return true; + size_t pos = s.find("://"); + if (pos == std::string::npos) return false; + std::string scheme(s, 0, pos); + return scheme == "http" || scheme == "https" || scheme == "file" || scheme == "channel" || scheme == "git" || scheme == "s3" || scheme == "ssh"; +} + +std::string EvalSettings::resolvePseudoUrl(std::string_view url) +{ + if (hasPrefix(url, "channel:")) + return "https://nixos.org/channels/" + std::string(url.substr(8)) + "/nixexprs.tar.xz"; + else + return std::string(url); +} + EvalSettings evalSettings; static GlobalConfig::Register rEvalSettings(&evalSettings); |