diff options
31 files changed, 982 insertions, 859 deletions
diff --git a/doc/manual/src/release-notes/rl-2.13.md b/doc/manual/src/release-notes/rl-2.13.md index 2b79620be..2ebf19f60 100644 --- a/doc/manual/src/release-notes/rl-2.13.md +++ b/doc/manual/src/release-notes/rl-2.13.md @@ -18,6 +18,10 @@ * Instead of "antiquotation", the more common term [string interpolation](../language/string-interpolation.md) is now used consistently. Historical release notes were not changed. +* Error traces have been reworked to provide detailed explanations and more + accurate error locations. A short excerpt of the trace is now shown by + default when an error occurs. + * Allow explicitly selecting outputs in a store derivation installable, just like we can do with other sorts of installables. For example, ```shell-session diff --git a/src/libcmd/installables.cc b/src/libcmd/installables.cc index 60d6e9dc0..5090ea6d2 100644 --- a/src/libcmd/installables.cc +++ b/src/libcmd/installables.cc @@ -554,7 +554,7 @@ ref<eval_cache::EvalCache> openEvalCache( auto vFlake = state.allocValue(); flake::callFlake(state, *lockedFlake, *vFlake); - state.forceAttrs(*vFlake, noPos); + state.forceAttrs(*vFlake, noPos, "while parsing cached flake data"); auto aOutputs = vFlake->attrs->get(state.symbols.create("outputs")); assert(aOutputs); @@ -618,7 +618,7 @@ DerivedPathsWithInfo InstallableFlake::toDerivedPaths() else if (v.type() == nString) { PathSet context; - auto s = state->forceString(v, context, noPos); + auto s = state->forceString(v, context, noPos, fmt("while evaluating the flake output attribute '%s'", attrPath)); auto storePath = state->store->maybeParseStorePath(s); if (storePath && context.count(std::string(s))) { return {{ diff --git a/src/libcmd/repl.cc b/src/libcmd/repl.cc index b7f691808..9b12f8fa2 100644 --- a/src/libcmd/repl.cc +++ b/src/libcmd/repl.cc @@ -397,7 +397,7 @@ StringSet NixRepl::completePrefix(const std::string & prefix) Expr * e = parseString(expr); Value v; e->eval(*state, *env, v); - state->forceAttrs(v, noPos); + state->forceAttrs(v, noPos, "nevermind, it is ignored anyway"); for (auto & i : *v.attrs) { std::string_view name = state->symbols[i.name]; @@ -590,7 +590,7 @@ bool NixRepl::processLine(std::string line) const auto [path, line] = [&] () -> std::pair<Path, uint32_t> { if (v.type() == nPath || v.type() == nString) { PathSet context; - auto path = state->coerceToPath(noPos, v, context); + auto path = state->coerceToPath(noPos, v, context, "while evaluating the filename to edit"); return {path, 0}; } else if (v.isLambda()) { auto pos = state->positions[v.lambda.fun->pos]; @@ -839,7 +839,7 @@ void NixRepl::loadFiles() void NixRepl::addAttrsToScope(Value & attrs) { - state->forceAttrs(attrs, [&]() { return attrs.determinePos(noPos); }); + state->forceAttrs(attrs, [&]() { return attrs.determinePos(noPos); }, "while evaluating an attribute set to be merged in the global scope"); if (displ + attrs.attrs->size() >= envSize) throw Error("environment full; cannot add more variables"); @@ -944,7 +944,7 @@ std::ostream & NixRepl::printValue(std::ostream & str, Value & v, unsigned int m Bindings::iterator i = v.attrs->find(state->sDrvPath); PathSet context; if (i != v.attrs->end()) - str << state->store->printStorePath(state->coerceToStorePath(i->pos, *i->value, context)); + str << state->store->printStorePath(state->coerceToStorePath(i->pos, *i->value, context, "while evaluating the drvPath of a derivation")); else str << "???"; str << "»"; diff --git a/src/libexpr/attr-path.cc b/src/libexpr/attr-path.cc index 94ab60f9a..7c0705091 100644 --- a/src/libexpr/attr-path.cc +++ b/src/libexpr/attr-path.cc @@ -118,7 +118,7 @@ std::pair<std::string, uint32_t> findPackageFilename(EvalState & state, Value & // FIXME: is it possible to extract the Pos object instead of doing this // toString + parsing? - auto pos = state.forceString(*v2); + auto pos = state.forceString(*v2, noPos, "while evaluating the 'meta.position' attribute of a derivation"); auto colon = pos.rfind(':'); if (colon == std::string::npos) diff --git a/src/libexpr/eval-cache.cc b/src/libexpr/eval-cache.cc index f8c4275a1..1219b2471 100644 --- a/src/libexpr/eval-cache.cc +++ b/src/libexpr/eval-cache.cc @@ -385,7 +385,7 @@ Value & AttrCursor::getValue() if (!_value) { if (parent) { auto & vParent = parent->first->getValue(); - root->state.forceAttrs(vParent, noPos); + root->state.forceAttrs(vParent, noPos, "while searching for an attribute"); auto attr = vParent.attrs->get(parent->second); if (!attr) throw Error("attribute '%s' is unexpectedly missing", getAttrPathStr()); @@ -571,14 +571,14 @@ std::string AttrCursor::getString() debug("using cached string attribute '%s'", getAttrPathStr()); return s->first; } else - root->state.debugThrowLastTrace(TypeError("'%s' is not a string", getAttrPathStr())); + root->state.error("'%s' is not a string", getAttrPathStr()).debugThrow<TypeError>(); } } auto & v = forceValue(); if (v.type() != nString && v.type() != nPath) - root->state.debugThrowLastTrace(TypeError("'%s' is not a string but %s", getAttrPathStr(), showType(v.type()))); + root->state.error("'%s' is not a string but %s", getAttrPathStr()).debugThrow<TypeError>(); return v.type() == nString ? v.string.s : v.path; } @@ -613,7 +613,7 @@ string_t AttrCursor::getStringWithContext() return *s; } } else - root->state.debugThrowLastTrace(TypeError("'%s' is not a string", getAttrPathStr())); + root->state.error("'%s' is not a string", getAttrPathStr()).debugThrow<TypeError>(); } } @@ -624,7 +624,7 @@ string_t AttrCursor::getStringWithContext() else if (v.type() == nPath) return {v.path, {}}; else - root->state.debugThrowLastTrace(TypeError("'%s' is not a string but %s", getAttrPathStr(), showType(v.type()))); + root->state.error("'%s' is not a string but %s", getAttrPathStr()).debugThrow<TypeError>(); } bool AttrCursor::getBool() @@ -637,14 +637,14 @@ bool AttrCursor::getBool() debug("using cached Boolean attribute '%s'", getAttrPathStr()); return *b; } else - root->state.debugThrowLastTrace(TypeError("'%s' is not a Boolean", getAttrPathStr())); + root->state.error("'%s' is not a Boolean", getAttrPathStr()).debugThrow<TypeError>(); } } auto & v = forceValue(); if (v.type() != nBool) - root->state.debugThrowLastTrace(TypeError("'%s' is not a Boolean", getAttrPathStr())); + root->state.error("'%s' is not a Boolean", getAttrPathStr()).debugThrow<TypeError>(); return v.boolean; } @@ -696,7 +696,7 @@ std::vector<std::string> AttrCursor::getListOfStrings() std::vector<std::string> res; for (auto & elem : v.listItems()) - res.push_back(std::string(root->state.forceStringNoCtx(*elem))); + res.push_back(std::string(root->state.forceStringNoCtx(*elem, noPos, "while evaluating an attribute for caching"))); if (root->db) cachedValue = {root->db->setListOfStrings(getKey(), res), res}; @@ -714,14 +714,14 @@ std::vector<Symbol> AttrCursor::getAttrs() debug("using cached attrset attribute '%s'", getAttrPathStr()); return *attrs; } else - root->state.debugThrowLastTrace(TypeError("'%s' is not an attribute set", getAttrPathStr())); + root->state.error("'%s' is not an attribute set", getAttrPathStr()).debugThrow<TypeError>(); } } auto & v = forceValue(); if (v.type() != nAttrs) - root->state.debugThrowLastTrace(TypeError("'%s' is not an attribute set", getAttrPathStr())); + root->state.error("'%s' is not an attribute set", getAttrPathStr()).debugThrow<TypeError>(); std::vector<Symbol> attrs; for (auto & attr : *getValue().attrs) diff --git a/src/libexpr/eval-inline.hh b/src/libexpr/eval-inline.hh index f2f4ba725..f0da688db 100644 --- a/src/libexpr/eval-inline.hh +++ b/src/libexpr/eval-inline.hh @@ -103,33 +103,36 @@ void EvalState::forceValue(Value & v, Callable getPos) else if (v.isApp()) callFunction(*v.app.left, *v.app.right, v, noPos); else if (v.isBlackhole()) - throwEvalError(getPos(), "infinite recursion encountered"); + error("infinite recursion encountered").atPos(getPos()).template debugThrow<EvalError>(); } [[gnu::always_inline]] -inline void EvalState::forceAttrs(Value & v, const PosIdx pos) +inline void EvalState::forceAttrs(Value & v, const PosIdx pos, std::string_view errorCtx) { - forceAttrs(v, [&]() { return pos; }); + forceAttrs(v, [&]() { return pos; }, errorCtx); } template <typename Callable> [[gnu::always_inline]] -inline void EvalState::forceAttrs(Value & v, Callable getPos) +inline void EvalState::forceAttrs(Value & v, Callable getPos, std::string_view errorCtx) { - forceValue(v, getPos); - if (v.type() != nAttrs) - throwTypeError(getPos(), "value is %1% while a set was expected", v); + forceValue(v, noPos); + if (v.type() != nAttrs) { + PosIdx pos = getPos(); + error("value is %1% while a set was expected", showType(v)).withTrace(pos, errorCtx).debugThrow<TypeError>(); + } } [[gnu::always_inline]] -inline void EvalState::forceList(Value & v, const PosIdx pos) +inline void EvalState::forceList(Value & v, const PosIdx pos, std::string_view errorCtx) { - forceValue(v, pos); - if (!v.isList()) - throwTypeError(pos, "value is %1% while a list was expected", v); + forceValue(v, noPos); + if (!v.isList()) { + error("value is %1% while a list was expected", showType(v)).withTrace(pos, errorCtx).debugThrow<TypeError>(); + } } diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 9bc20a502..277cbb5f9 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -318,7 +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); } } @@ -414,6 +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, @@ -646,25 +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 }); } @@ -842,176 +862,14 @@ 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(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( @@ -1088,7 +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; } @@ -1098,7 +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) ; } } @@ -1248,7 +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); @@ -1266,31 +1124,31 @@ void EvalState::eval(Expr * e, Value & v) } -inline bool EvalState::evalBool(Env & env, Expr * e) -{ - 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) +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(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; + } } @@ -1363,7 +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); @@ -1391,11 +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 */ @@ -1492,15 +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; @@ -1595,7 +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]; @@ -1607,8 +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++; @@ -1626,11 +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 } @@ -1653,11 +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, "while evaluating 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; } @@ -1676,9 +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; @@ -1713,9 +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; @@ -1728,14 +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; @@ -1799,13 +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/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>(); } } } @@ -1828,16 +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); } @@ -1845,7 +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: ! } @@ -1853,7 +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")); } @@ -1861,33 +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++; @@ -1926,18 +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]; @@ -2014,20 +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)); } @@ -2041,7 +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); @@ -2091,33 +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; + } } @@ -2127,21 +2041,30 @@ bool EvalState::isFunctor(Value & fun) } -void EvalState::forceFunction(Value & v, const PosIdx pos) +void EvalState::forceFunction(Value & v, const PosIdx pos, std::string_view errorCtx) { - forceValue(v, pos); - if (v.type() != nFunction && !isFunctor(v)) - throwTypeError(pos, "value is %1% while a function 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; + } } -std::string_view EvalState::forceString(Value & v, const PosIdx pos) +std::string_view EvalState::forceString(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() != 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; } - return v.string.s; } @@ -2164,24 +2087,19 @@ NixStringContext Value::getContext(const Store & store) } -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; } @@ -2205,14 +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); @@ -2236,12 +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 @@ -2255,7 +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)) @@ -2265,14 +2190,14 @@ 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>(); } StorePath EvalState::copyPathToStore(PathSet & context, const Path & path) { if (nix::isDerivation(path)) - throwEvalError("file names are not allowed to end in '%1%'", drvExtension); + error("file names are not allowed to end in '%1%'", drvExtension).debugThrow<EvalError>(); auto dstPath = [&]() -> StorePath { @@ -2293,28 +2218,25 @@ StorePath EvalState::copyPathToStore(PathSet & context, const Path & path) } -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); @@ -2334,7 +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; @@ -2353,7 +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: { @@ -2363,7 +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; @@ -2371,7 +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; @@ -2388,9 +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>(); } } @@ -2514,12 +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; } diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh index df6ac431d..46b8cbaa5 100644 --- a/src/libexpr/eval.hh +++ b/src/libexpr/eval.hh @@ -86,6 +86,43 @@ struct DebugTrace { void debugError(Error * e, Env & env, Expr & expr); +class ErrorBuilder +{ + private: + EvalState & state; + ErrorInfo info; + + ErrorBuilder(EvalState & s, ErrorInfo && i): state(s), info(i) { } + + public: + template<typename... Args> + [[nodiscard, gnu::noinline]] + static ErrorBuilder * create(EvalState & s, const Args & ... args) + { + return new ErrorBuilder(s, ErrorInfo { .msg = hintfmt(args...) }); + } + + [[nodiscard, gnu::noinline]] + ErrorBuilder & atPos(PosIdx pos); + + [[nodiscard, gnu::noinline]] + ErrorBuilder & withTrace(PosIdx pos, const std::string_view text); + + [[nodiscard, gnu::noinline]] + ErrorBuilder & withFrameTrace(PosIdx pos, const std::string_view text); + + [[nodiscard, gnu::noinline]] + ErrorBuilder & withSuggestions(Suggestions & s); + + [[nodiscard, gnu::noinline]] + ErrorBuilder & withFrame(const Env & e, const Expr & ex); + + template<class ErrorType> + [[gnu::noinline, gnu::noreturn]] + void debugThrow(); +}; + + class EvalState : public std::enable_shared_from_this<EvalState> { public: @@ -145,29 +182,35 @@ public: template<class E> [[gnu::noinline, gnu::noreturn]] - void debugThrow(E && error, const Env & env, const Expr & expr) + void debugThrowLastTrace(E && error) { - if (debugRepl) - runDebugRepl(&error, env, expr); - - throw std::move(error); + debugThrow(error, nullptr, nullptr); } template<class E> [[gnu::noinline, gnu::noreturn]] - void debugThrowLastTrace(E && e) + void debugThrow(E && error, const Env * env, const Expr * expr) { - // Call this in the situation where Expr and Env are inaccessible. - // The debugger will start in the last context that's in the - // DebugTrace stack. - if (debugRepl && !debugTraces.empty()) { - const DebugTrace & last = debugTraces.front(); - runDebugRepl(&e, last.env, last.expr); + if (debugRepl && ((env && expr) || !debugTraces.empty())) { + if (!env || !expr) { + const DebugTrace & last = debugTraces.front(); + env = &last.env; + expr = &last.expr; + } + runDebugRepl(&error, *env, *expr); } - throw std::move(e); + throw std::move(error); } + ErrorBuilder * errorBuilder; + + template<typename... Args> + [[nodiscard, gnu::noinline]] + ErrorBuilder & error(const Args & ... args) { + errorBuilder = ErrorBuilder::create(*this, args...); + return *errorBuilder; + } private: SrcToStore srcToStore; @@ -282,8 +325,8 @@ public: /* Evaluation the expression, then verify that it has the expected type. */ inline bool evalBool(Env & env, Expr * e); - inline bool evalBool(Env & env, Expr * e, const PosIdx pos); - inline void evalAttrs(Env & env, Expr * e, Value & v); + inline bool evalBool(Env & env, Expr * e, const PosIdx pos, std::string_view errorCtx); + inline void evalAttrs(Env & env, Expr * e, Value & v, const PosIdx pos, std::string_view errorCtx); /* If `v' is a thunk, enter it and overwrite `v' with the result of the evaluation of the thunk. If `v' is a delayed function @@ -299,89 +342,25 @@ public: void forceValueDeep(Value & v); /* Force `v', and then verify that it has the expected type. */ - NixInt forceInt(Value & v, const PosIdx pos); - NixFloat forceFloat(Value & v, const PosIdx pos); - bool forceBool(Value & v, const PosIdx pos); + NixInt forceInt(Value & v, const PosIdx pos, std::string_view errorCtx); + NixFloat forceFloat(Value & v, const PosIdx pos, std::string_view errorCtx); + bool forceBool(Value & v, const PosIdx pos, std::string_view errorCtx); - void forceAttrs(Value & v, const PosIdx pos); + void forceAttrs(Value & v, const PosIdx pos, std::string_view errorCtx); template <typename Callable> - inline void forceAttrs(Value & v, Callable getPos); - - inline void forceList(Value & v, const PosIdx pos); - void forceFunction(Value & v, const PosIdx pos); // either lambda or primop - std::string_view forceString(Value & v, const PosIdx pos = noPos); - std::string_view forceString(Value & v, PathSet & context, const PosIdx pos = noPos); - std::string_view forceStringNoCtx(Value & v, const PosIdx pos = noPos); - - [[gnu::noinline, gnu::noreturn]] - void throwEvalError(const PosIdx pos, const char * s); - [[gnu::noinline, gnu::noreturn]] - void throwEvalError(const PosIdx pos, const char * s, - Env & env, Expr & expr); - [[gnu::noinline, gnu::noreturn]] - void throwEvalError(const char * s, const std::string & s2); - [[gnu::noinline, gnu::noreturn]] - void throwEvalError(const PosIdx pos, const char * s, const std::string & s2); - [[gnu::noinline, gnu::noreturn]] - void throwEvalError(const char * s, const std::string & s2, - Env & env, Expr & expr); - [[gnu::noinline, gnu::noreturn]] - void throwEvalError(const PosIdx pos, const char * s, const std::string & s2, - Env & env, Expr & expr); - [[gnu::noinline, gnu::noreturn]] - void throwEvalError(const char * s, const std::string & s2, const std::string & s3, - Env & env, Expr & expr); - [[gnu::noinline, gnu::noreturn]] - void throwEvalError(const PosIdx pos, const char * s, const std::string & s2, const std::string & s3, - Env & env, Expr & expr); - [[gnu::noinline, gnu::noreturn]] - void throwEvalError(const PosIdx pos, const char * s, const std::string & s2, const std::string & s3); - [[gnu::noinline, gnu::noreturn]] - void throwEvalError(const char * s, const std::string & s2, const std::string & s3); - [[gnu::noinline, gnu::noreturn]] - void throwEvalError(const PosIdx pos, const Suggestions & suggestions, const char * s, const std::string & s2, - Env & env, Expr & expr); - [[gnu::noinline, gnu::noreturn]] - void throwEvalError(const PosIdx p1, const char * s, const Symbol sym, const PosIdx p2, - Env & env, Expr & expr); + inline void forceAttrs(Value & v, Callable getPos, std::string_view errorCtx); - [[gnu::noinline, gnu::noreturn]] - void throwTypeError(const PosIdx pos, const char * s, const Value & v); - [[gnu::noinline, gnu::noreturn]] - void throwTypeError(const PosIdx pos, const char * s, const Value & v, - Env & env, Expr & expr); - [[gnu::noinline, gnu::noreturn]] - void throwTypeError(const PosIdx pos, const char * s); - [[gnu::noinline, gnu::noreturn]] - void throwTypeError(const PosIdx pos, const char * s, - Env & env, Expr & expr); - [[gnu::noinline, gnu::noreturn]] - void throwTypeError(const PosIdx pos, const char * s, const ExprLambda & fun, const Symbol s2, - Env & env, Expr & expr); - [[gnu::noinline, gnu::noreturn]] - void throwTypeError(const PosIdx pos, const Suggestions & suggestions, const char * s, const ExprLambda & fun, const Symbol s2, - Env & env, Expr & expr); - [[gnu::noinline, gnu::noreturn]] - void throwTypeError(const char * s, const Value & v, - Env & env, Expr & expr); - - [[gnu::noinline, gnu::noreturn]] - void throwAssertionError(const PosIdx pos, const char * s, const std::string & s1, - Env & env, Expr & expr); - - [[gnu::noinline, gnu::noreturn]] - void throwUndefinedVarError(const PosIdx pos, const char * s, const std::string & s1, - Env & env, Expr & expr); - - [[gnu::noinline, gnu::noreturn]] - void throwMissingArgumentError(const PosIdx pos, const char * s, const std::string & s1, - Env & env, Expr & expr); + inline void forceList(Value & v, const PosIdx pos, std::string_view errorCtx); + void forceFunction(Value & v, const PosIdx pos, std::string_view errorCtx); // either lambda or primop + std::string_view forceString(Value & v, const PosIdx pos, std::string_view errorCtx); + std::string_view forceString(Value & v, PathSet & context, const PosIdx pos, std::string_view errorCtx); + std::string_view forceStringNoCtx(Value & v, const PosIdx pos, std::string_view errorCtx); [[gnu::noinline]] void addErrorTrace(Error & e, const char * s, const std::string & s2) const; [[gnu::noinline]] - void addErrorTrace(Error & e, const PosIdx pos, const char * s, const std::string & s2) const; + void addErrorTrace(Error & e, const PosIdx pos, const char * s, const std::string & s2, bool frame = false) const; public: /* Return true iff the value `v' denotes a derivation (i.e. a @@ -397,17 +376,18 @@ public: referenced paths are copied to the Nix store as a side effect. */ BackedStringView coerceToString(const PosIdx pos, Value & v, PathSet & context, bool coerceMore = false, bool copyToStore = true, - bool canonicalizePath = true); + bool canonicalizePath = true, + std::string_view errorCtx = ""); StorePath copyPathToStore(PathSet & context, const Path & path); /* Path coercion. Converts strings, paths and derivations to a path. The result is guaranteed to be a canonicalised, absolute path. Nothing is copied to the store. */ - Path coerceToPath(const PosIdx pos, Value & v, PathSet & context); + Path coerceToPath(const PosIdx pos, Value & v, PathSet & context, std::string_view errorCtx); /* Like coerceToPath, but the result must be a store path. */ - StorePath coerceToStorePath(const PosIdx pos, Value & v, PathSet & context); + StorePath coerceToStorePath(const PosIdx pos, Value & v, PathSet & context, std::string_view errorCtx); public: @@ -467,7 +447,7 @@ public: /* Do a deep equality test between two values. That is, list elements and attributes are compared recursively. */ - bool eqValues(Value & v1, Value & v2); + bool eqValues(Value & v1, Value & v2, const PosIdx pos, std::string_view errorCtx); bool isFunctor(Value & fun); @@ -502,7 +482,7 @@ public: void mkThunk_(Value & v, Expr * expr); void mkPos(Value & v, PosIdx pos); - void concatLists(Value & v, size_t nrLists, Value * * lists, const PosIdx pos); + void concatLists(Value & v, size_t nrLists, Value * * lists, const PosIdx pos, std::string_view errorCtx); /* Print statistics. */ void printStats(); @@ -665,6 +645,13 @@ extern EvalSettings evalSettings; static const std::string corepkgsPrefix{"/__corepkgs__/"}; +template<class ErrorType> +void ErrorBuilder::debugThrow() +{ + // NOTE: We always use the -LastTrace version as we push the new trace in withFrame() + state.debugThrowLastTrace(ErrorType(info)); +} + } #include "eval-inline.hh" diff --git a/src/libexpr/flake/flake.cc b/src/libexpr/flake/flake.cc index 105d32467..fc4be5678 100644 --- a/src/libexpr/flake/flake.cc +++ b/src/libexpr/flake/flake.cc @@ -259,28 +259,28 @@ static Flake getFlake( if (setting.value->type() == nString) flake.config.settings.emplace( state.symbols[setting.name], - std::string(state.forceStringNoCtx(*setting.value, setting.pos))); + std::string(state.forceStringNoCtx(*setting.value, setting.pos, ""))); else if (setting.value->type() == nPath) { PathSet emptyContext = {}; flake.config.settings.emplace( state.symbols[setting.name], - state.coerceToString(setting.pos, *setting.value, emptyContext, false, true, true) .toOwned()); + state.coerceToString(setting.pos, *setting.value, emptyContext, false, true, true, "") .toOwned()); } else if (setting.value->type() == nInt) flake.config.settings.emplace( state.symbols[setting.name], - state.forceInt(*setting.value, setting.pos)); + state.forceInt(*setting.value, setting.pos, "")); else if (setting.value->type() == nBool) flake.config.settings.emplace( state.symbols[setting.name], - Explicit<bool> { state.forceBool(*setting.value, setting.pos) }); + Explicit<bool> { state.forceBool(*setting.value, setting.pos, "") }); else if (setting.value->type() == nList) { std::vector<std::string> ss; for (auto elem : setting.value->listItems()) { if (elem->type() != nString) throw TypeError("list element in flake configuration setting '%s' is %s while a string is expected", state.symbols[setting.name], showType(*setting.value)); - ss.emplace_back(state.forceStringNoCtx(*elem, setting.pos)); + ss.emplace_back(state.forceStringNoCtx(*elem, setting.pos, "")); } flake.config.settings.emplace(state.symbols[setting.name], ss); } @@ -741,7 +741,7 @@ void callFlake(EvalState & state, static void prim_getFlake(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - std::string flakeRefS(state.forceStringNoCtx(*args[0], pos)); + std::string flakeRefS(state.forceStringNoCtx(*args[0], pos, "while evaluating the argument passed to builtins.getFlake")); auto flakeRef = parseFlakeRef(flakeRefS, {}, true); if (evalSettings.pureEval && !flakeRef.input.isLocked()) throw Error("cannot call 'getFlake' on unlocked flake reference '%s', at %s (use --impure to override)", flakeRefS, state.positions[pos]); diff --git a/src/libexpr/get-drvs.cc b/src/libexpr/get-drvs.cc index 5ad5d1fd4..1602fbffb 100644 --- a/src/libexpr/get-drvs.cc +++ b/src/libexpr/get-drvs.cc @@ -51,7 +51,7 @@ std::string DrvInfo::queryName() const if (name == "" && attrs) { auto i = attrs->find(state->sName); if (i == attrs->end()) throw TypeError("derivation name missing"); - name = state->forceStringNoCtx(*i->value); + name = state->forceStringNoCtx(*i->value, noPos, "while evaluating the 'name' attribute of a derivation"); } return name; } @@ -61,7 +61,7 @@ std::string DrvInfo::querySystem() const { if (system == "" && attrs) { auto i = attrs->find(state->sSystem); - system = i == attrs->end() ? "unknown" : state->forceStringNoCtx(*i->value, i->pos); + system = i == attrs->end() ? "unknown" : state->forceStringNoCtx(*i->value, i->pos, "while evaluating the 'system' attribute of a derivation"); } return system; } @@ -75,7 +75,7 @@ std::optional<StorePath> DrvInfo::queryDrvPath() const if (i == attrs->end()) drvPath = {std::nullopt}; else - drvPath = {state->coerceToStorePath(i->pos, *i->value, context)}; + drvPath = {state->coerceToStorePath(i->pos, *i->value, context, "while evaluating the 'drvPath' attribute of a derivation")}; } return drvPath.value_or(std::nullopt); } @@ -95,7 +95,7 @@ StorePath DrvInfo::queryOutPath() const Bindings::iterator i = attrs->find(state->sOutPath); PathSet context; if (i != attrs->end()) - outPath = state->coerceToStorePath(i->pos, *i->value, context); + outPath = state->coerceToStorePath(i->pos, *i->value, context, "while evaluating the output path of a derivation"); } if (!outPath) throw UnimplementedError("CA derivations are not yet supported"); @@ -109,23 +109,23 @@ DrvInfo::Outputs DrvInfo::queryOutputs(bool withPaths, bool onlyOutputsToInstall /* Get the ‘outputs’ list. */ Bindings::iterator i; if (attrs && (i = attrs->find(state->sOutputs)) != attrs->end()) { - state->forceList(*i->value, i->pos); + state->forceList(*i->value, i->pos, "while evaluating the 'outputs' attribute of a derivation"); /* For each output... */ for (auto elem : i->value->listItems()) { - std::string output(state->forceStringNoCtx(*elem, i->pos)); + std::string output(state->forceStringNoCtx(*elem, i->pos, "while evaluating the name of an output of a derivation")); if (withPaths) { /* Evaluate the corresponding set. */ Bindings::iterator out = attrs->find(state->symbols.create(output)); if (out == attrs->end()) continue; // FIXME: throw error? - state->forceAttrs(*out->value, i->pos); + state->forceAttrs(*out->value, i->pos, "while evaluating an output of a derivation"); /* And evaluate its ‘outPath’ attribute. */ Bindings::iterator outPath = out->value->attrs->find(state->sOutPath); if (outPath == out->value->attrs->end()) continue; // FIXME: throw error? PathSet context; - outputs.emplace(output, state->coerceToStorePath(outPath->pos, *outPath->value, context)); + outputs.emplace(output, state->coerceToStorePath(outPath->pos, *outPath->value, context, "while evaluating an output path of a derivation")); } else outputs.emplace(output, std::nullopt); } @@ -137,7 +137,7 @@ DrvInfo::Outputs DrvInfo::queryOutputs(bool withPaths, bool onlyOutputsToInstall return outputs; Bindings::iterator i; - if (attrs && (i = attrs->find(state->sOutputSpecified)) != attrs->end() && state->forceBool(*i->value, i->pos)) { + if (attrs && (i = attrs->find(state->sOutputSpecified)) != attrs->end() && state->forceBool(*i->value, i->pos, "while evaluating the 'outputSpecified' attribute of a derivation")) { Outputs result; auto out = outputs.find(queryOutputName()); if (out == outputs.end()) @@ -169,7 +169,7 @@ std::string DrvInfo::queryOutputName() const { if (outputName == "" && attrs) { Bindings::iterator i = attrs->find(state->sOutputName); - outputName = i != attrs->end() ? state->forceStringNoCtx(*i->value) : ""; + outputName = i != attrs->end() ? state->forceStringNoCtx(*i->value, noPos, "while evaluating the output name of a derivation") : ""; } return outputName; } @@ -181,7 +181,7 @@ Bindings * DrvInfo::getMeta() if (!attrs) return 0; Bindings::iterator a = attrs->find(state->sMeta); if (a == attrs->end()) return 0; - state->forceAttrs(*a->value, a->pos); + state->forceAttrs(*a->value, a->pos, "while evaluating the 'meta' attribute of a derivation"); meta = a->value->attrs; return meta; } @@ -382,7 +382,7 @@ static void getDerivations(EvalState & state, Value & vIn, `recurseForDerivations = true' attribute. */ if (i->value->type() == nAttrs) { Bindings::iterator j = i->value->attrs->find(state.sRecurseForDerivations); - if (j != i->value->attrs->end() && state.forceBool(*j->value, j->pos)) + if (j != i->value->attrs->end() && state.forceBool(*j->value, j->pos, "while evaluating the attribute `recurseForDerivations`")) getDerivations(state, *i->value, pathPrefix2, autoArgs, drvs, done, ignoreAssertionFailures); } } diff --git a/src/libexpr/nixexpr.hh b/src/libexpr/nixexpr.hh index ac7ce021e..ffe67f97d 100644 --- a/src/libexpr/nixexpr.hh +++ b/src/libexpr/nixexpr.hh @@ -8,7 +8,6 @@ #include "error.hh" #include "chunked-vector.hh" - namespace nix { diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y index e07909f8e..ffb364a90 100644 --- a/src/libexpr/parser.y +++ b/src/libexpr/parser.y @@ -400,21 +400,21 @@ expr_op | '-' 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 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); } - | expr_op UPDATE expr_op { $$ = new ExprOpUpdate(CUR_POS, $1, $3); } + | expr_op '<' expr_op { $$ = 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); } | expr_op '+' expr_op - { $$ = new ExprConcatStrings(CUR_POS, false, new std::vector<std::pair<PosIdx, Expr *>>({{makeCurPos(@1, data), $1}, {makeCurPos(@3, data), $3}})); } - | expr_op '-' expr_op { $$ = 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 { $$ = new ExprOpConcatLists(CUR_POS, $1, $3); } + { $$ = 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 ; @@ -782,13 +782,13 @@ Path EvalState::findFile(SearchPath & searchPath, const std::string_view path, c if (hasPrefix(path, "nix/")) return concatStrings(corepkgsPrefix, path.substr(4)); - debugThrowLastTrace(ThrownError({ + debugThrow(ThrownError({ .msg = hintfmt(evalSettings.pureEval ? "cannot look up '<%s>' in pure evaluation mode (use '--impure' to override)" : "file '%s' was not found in the Nix search path (add it using $NIX_PATH or -I)", path), .errPos = positions[pos] - })); + }), 0, 0); } diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc index 080892cbd..9cff4b365 100644 --- a/src/libexpr/primops.cc +++ b/src/libexpr/primops.cc @@ -114,15 +114,7 @@ static Path realisePath(EvalState & state, const PosIdx pos, Value & v, const Re { PathSet context; - auto path = [&]() - { - try { - return state.coerceToPath(pos, v, context); - } catch (Error & e) { - e.addTrace(state.positions[pos], "while realising the context of a path"); - throw; - } - }(); + auto path = state.coerceToPath(noPos, v, context, "while realising the context of a path"); try { StringMap rewrites = state.realiseContext(context); @@ -209,9 +201,9 @@ static void import(EvalState & state, const PosIdx pos, Value & vPath, Value * v , "/"), **state.vImportedDrvToDerivation); } - state.forceFunction(**state.vImportedDrvToDerivation, pos); + state.forceFunction(**state.vImportedDrvToDerivation, pos, "while evaluating imported-drv-to-derivation.nix.gen.hh"); v.mkApp(*state.vImportedDrvToDerivation, w); - state.forceAttrs(v, pos); + state.forceAttrs(v, pos, "while calling imported-drv-to-derivation.nix.gen.hh"); } else if (path == corepkgsPrefix + "fetchurl.nix") { @@ -224,7 +216,7 @@ static void import(EvalState & state, const PosIdx pos, Value & vPath, Value * v if (!vScope) state.evalFile(path, v); else { - state.forceAttrs(*vScope, pos); + state.forceAttrs(*vScope, pos, "while evaluating the first argument passed to builtins.scopedImport"); Env * env = &state.allocEnv(vScope->attrs->size()); env->up = &state.baseEnv; @@ -329,7 +321,7 @@ void prim_importNative(EvalState & state, const PosIdx pos, Value * * args, Valu { auto path = realisePath(state, pos, *args[0]); - std::string sym(state.forceStringNoCtx(*args[1], pos)); + std::string sym(state.forceStringNoCtx(*args[1], pos, "while evaluating the second argument passed to builtins.importNative")); void *handle = dlopen(path.c_str(), RTLD_LAZY | RTLD_LOCAL); if (!handle) @@ -354,7 +346,7 @@ void prim_importNative(EvalState & state, const PosIdx pos, Value * * args, Valu /* Execute a program and parse its output */ void prim_exec(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceList(*args[0], pos); + state.forceList(*args[0], pos, "while evaluating the first argument passed to builtins.exec"); auto elems = args[0]->listElems(); auto count = args[0]->listSize(); if (count == 0) @@ -363,10 +355,12 @@ void prim_exec(EvalState & state, const PosIdx pos, Value * * args, Value & v) .errPos = state.positions[pos] })); PathSet context; - auto program = state.coerceToString(pos, *elems[0], context, false, false).toOwned(); + auto program = state.coerceToString(pos, *elems[0], context, false, false, + "while evaluating the first element of the argument passed to builtins.exec").toOwned(); Strings commandArgs; for (unsigned int i = 1; i < args[0]->listSize(); ++i) { - commandArgs.push_back(state.coerceToString(pos, *elems[i], context, false, false).toOwned()); + commandArgs.push_back(state.coerceToString(pos, *elems[i], context, false, false, + "while evaluating an element of the argument passed to builtins.exec").toOwned()); } try { auto _ = state.realiseContext(context); // FIXME: Handle CA derivations @@ -383,18 +377,17 @@ void prim_exec(EvalState & state, const PosIdx pos, Value * * args, Value & v) try { parsed = state.parseExprFromString(std::move(output), "/"); } catch (Error & e) { - e.addTrace(state.positions[pos], "While parsing the output from '%1%'", program); + e.addTrace(state.positions[pos], "while parsing the output from '%1%'", program); throw; } try { state.eval(parsed, v); } catch (Error & e) { - e.addTrace(state.positions[pos], "While evaluating the output from '%1%'", program); + e.addTrace(state.positions[pos], "while evaluating the output from '%1%'", program); throw; } } - /* Return a string representing the type of the expression. */ static void prim_typeOf(EvalState & state, const PosIdx pos, Value * * args, Value & v) { @@ -545,42 +538,68 @@ static RegisterPrimOp primop_isPath({ .fun = prim_isPath, }); +template<typename Callable> + static inline void withExceptionContext(Trace trace, Callable&& func) +{ + try + { + func(); + } + catch(Error & e) + { + e.pushTrace(trace); + throw; + } +} + struct CompareValues { EvalState & state; + const PosIdx pos; + const std::string_view errorCtx; - CompareValues(EvalState & state) : state(state) { }; + CompareValues(EvalState & state, const PosIdx pos, const std::string_view && errorCtx) : state(state), pos(pos), errorCtx(errorCtx) { }; bool operator () (Value * v1, Value * v2) const { - if (v1->type() == nFloat && v2->type() == nInt) - return v1->fpoint < v2->integer; - if (v1->type() == nInt && v2->type() == nFloat) - return v1->integer < v2->fpoint; - if (v1->type() != v2->type()) - state.debugThrowLastTrace(EvalError("cannot compare %1% with %2%", showType(*v1), showType(*v2))); - switch (v1->type()) { - case nInt: - return v1->integer < v2->integer; - case nFloat: - return v1->fpoint < v2->fpoint; - case nString: - return strcmp(v1->string.s, v2->string.s) < 0; - case nPath: - return strcmp(v1->path, v2->path) < 0; - case nList: - // Lexicographic comparison - for (size_t i = 0;; i++) { - if (i == v2->listSize()) { - return false; - } else if (i == v1->listSize()) { - return true; - } else if (!state.eqValues(*v1->listElems()[i], *v2->listElems()[i])) { - return (*this)(v1->listElems()[i], v2->listElems()[i]); + return (*this)(v1, v2, errorCtx); + } + + bool operator () (Value * v1, Value * v2, std::string_view errorCtx) const + { + try { + if (v1->type() == nFloat && v2->type() == nInt) + return v1->fpoint < v2->integer; + if (v1->type() == nInt && v2->type() == nFloat) + return v1->integer < v2->fpoint; + if (v1->type() != v2->type()) + state.error("cannot compare %s with %s", showType(*v1), showType(*v2)).debugThrow<EvalError>(); + switch (v1->type()) { + case nInt: + return v1->integer < v2->integer; + case nFloat: + return v1->fpoint < v2->fpoint; + case nString: + return strcmp(v1->string.s, v2->string.s) < 0; + case nPath: + return strcmp(v1->path, v2->path) < 0; + case nList: + // Lexicographic comparison + for (size_t i = 0;; i++) { + if (i == v2->listSize()) { + return false; + } else if (i == v1->listSize()) { + return true; + } else if (!state.eqValues(*v1->listElems()[i], *v2->listElems()[i], pos, errorCtx)) { + return (*this)(v1->listElems()[i], v2->listElems()[i], "while comparing two list elements"); + } } - } - default: - state.debugThrowLastTrace(EvalError("cannot compare %1% with %2%", showType(*v1), showType(*v2))); + default: + state.error("cannot compare %s with %s; values of that type are incomparable", showType(*v1), showType(*v2)).debugThrow<EvalError>(); + } + } catch (Error & e) { + e.addTrace(nullptr, errorCtx); + throw; } } }; @@ -595,105 +614,75 @@ typedef std::list<Value *> ValueList; static Bindings::iterator getAttr( EvalState & state, - std::string_view funcName, Symbol attrSym, Bindings * attrSet, - const PosIdx pos) + std::string_view errorCtx) { Bindings::iterator value = attrSet->find(attrSym); if (value == attrSet->end()) { - hintformat errorMsg = hintfmt( - "attribute '%s' missing for call to '%s'", - state.symbols[attrSym], - funcName - ); - - auto aPos = attrSet->pos; - if (!aPos) { - state.debugThrowLastTrace(TypeError({ - .msg = errorMsg, - .errPos = state.positions[pos], - })); - } else { - auto e = TypeError({ - .msg = errorMsg, - .errPos = state.positions[aPos], - }); - - // Adding another trace for the function name to make it clear - // which call received wrong arguments. - e.addTrace(state.positions[pos], hintfmt("while invoking '%s'", funcName)); - state.debugThrowLastTrace(e); - } + throw TypeError({ + .msg = hintfmt("attribute '%s' missing %s", state.symbols[attrSym], normaltxt(errorCtx)), + .errPos = state.positions[attrSet->pos], + }); + // TODO XXX + // Adding another trace for the function name to make it clear + // which call received wrong arguments. + //e.addTrace(state.positions[pos], hintfmt("while invoking '%s'", funcName)); + //state.debugThrowLastTrace(e); } - return value; } static void prim_genericClosure(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceAttrs(*args[0], pos); + state.forceAttrs(*args[0], noPos, "while evaluating the first argument passed to builtins.genericClosure"); /* Get the start set. */ - Bindings::iterator startSet = getAttr( - state, - "genericClosure", - state.sStartSet, - args[0]->attrs, - pos - ); + Bindings::iterator startSet = getAttr(state, state.sStartSet, args[0]->attrs, "in the attrset passed as argument to builtins.genericClosure"); - state.forceList(*startSet->value, pos); + state.forceList(*startSet->value, noPos, "while evaluating the 'startSet' attribute passed as argument to builtins.genericClosure"); ValueList workSet; for (auto elem : startSet->value->listItems()) workSet.push_back(elem); - /* Get the operator. */ - Bindings::iterator op = getAttr( - state, - "genericClosure", - state.sOperator, - args[0]->attrs, - pos - ); + if (startSet->value->listSize() == 0) { + v = *startSet->value; + return; + } - state.forceValue(*op->value, pos); + /* Get the operator. */ + Bindings::iterator op = getAttr(state, state.sOperator, args[0]->attrs, "in the attrset passed as argument to builtins.genericClosure"); + state.forceFunction(*op->value, noPos, "while evaluating the 'operator' attribute passed as argument to builtins.genericClosure"); - /* Construct the closure by applying the operator to element of + /* Construct the closure by applying the operator to elements of `workSet', adding the result to `workSet', continuing until no new elements are found. */ ValueList res; // `doneKeys' doesn't need to be a GC root, because its values are // reachable from res. - auto cmp = CompareValues(state); + auto cmp = CompareValues(state, noPos, "while comparing the `key` attributes of two genericClosure elements"); std::set<Value *, decltype(cmp)> doneKeys(cmp); while (!workSet.empty()) { Value * e = *(workSet.begin()); workSet.pop_front(); - state.forceAttrs(*e, pos); + state.forceAttrs(*e, noPos, "while evaluating one of the elements generated by (or initially passed to) builtins.genericClosure"); - Bindings::iterator key = - e->attrs->find(state.sKey); - if (key == e->attrs->end()) - state.debugThrowLastTrace(EvalError({ - .msg = hintfmt("attribute 'key' required"), - .errPos = state.positions[pos] - })); - state.forceValue(*key->value, pos); + Bindings::iterator key = getAttr(state, state.sKey, e->attrs, "in one of the attrsets generated by (or initially passed to) builtins.genericClosure"); + state.forceValue(*key->value, noPos); if (!doneKeys.insert(key->value).second) continue; res.push_back(e); /* Call the `operator' function with `e' as argument. */ - Value call; - call.mkApp(op->value, e); - state.forceList(call, pos); + Value newElements; + state.callFunction(*op->value, 1, &e, newElements, noPos); + state.forceList(newElements, noPos, "while evaluating the return value of the `operator` passed to builtins.genericClosure"); /* Add the values returned by the operator to the work set. */ - for (auto elem : call.listItems()) { - state.forceValue(*elem, pos); + for (auto elem : newElements.listItems()) { + state.forceValue(*elem, noPos); // "while evaluating one one of the elements returned by the `operator` passed to builtins.genericClosure"); workSet.push_back(elem); } } @@ -761,7 +750,7 @@ static RegisterPrimOp primop_break({ throw Error(ErrorInfo{ .level = lvlInfo, .msg = hintfmt("quit the debugger"), - .errPos = state.positions[noPos], + .errPos = nullptr, }); } } @@ -780,7 +769,8 @@ static RegisterPrimOp primop_abort({ .fun = [](EvalState & state, const PosIdx pos, Value * * args, Value & v) { PathSet context; - auto s = state.coerceToString(pos, *args[0], context).toOwned(); + auto s = state.coerceToString(pos, *args[0], context, + "while evaluating the error message passed to builtins.abort").toOwned(); state.debugThrowLastTrace(Abort("evaluation aborted with the following error message: '%1%'", s)); } }); @@ -798,7 +788,8 @@ static RegisterPrimOp primop_throw({ .fun = [](EvalState & state, const PosIdx pos, Value * * args, Value & v) { PathSet context; - auto s = state.coerceToString(pos, *args[0], context).toOwned(); + auto s = state.coerceToString(pos, *args[0], context, + "while evaluating the error message passed to builtin.throw").toOwned(); state.debugThrowLastTrace(ThrownError(s)); } }); @@ -810,7 +801,8 @@ static void prim_addErrorContext(EvalState & state, const PosIdx pos, Value * * v = *args[1]; } catch (Error & e) { PathSet context; - e.addTrace(nullptr, state.coerceToString(pos, *args[0], context).toOwned()); + e.addTrace(nullptr, state.coerceToString(pos, *args[0], context, + "while evaluating the error message passed to builtins.addErrorContext").toOwned()); throw; } } @@ -823,7 +815,8 @@ static RegisterPrimOp primop_addErrorContext(RegisterPrimOp::Info { static void prim_ceil(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - auto value = state.forceFloat(*args[0], args[0]->determinePos(pos)); + auto value = state.forceFloat(*args[0], args[0]->determinePos(pos), + "while evaluating the first argument passed to builtins.ceil"); v.mkInt(ceil(value)); } @@ -842,7 +835,7 @@ static RegisterPrimOp primop_ceil({ static void prim_floor(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - auto value = state.forceFloat(*args[0], args[0]->determinePos(pos)); + auto value = state.forceFloat(*args[0], args[0]->determinePos(pos), "while evaluating the first argument passed to builtins.floor"); v.mkInt(floor(value)); } @@ -916,7 +909,7 @@ static RegisterPrimOp primop_tryEval({ /* Return an environment variable. Use with care. */ static void prim_getEnv(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - std::string name(state.forceStringNoCtx(*args[0], pos)); + std::string name(state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.getEnv")); v.mkString(evalSettings.restrictEval || evalSettings.pureEval ? "" : getEnv(name).value_or("")); } @@ -1024,21 +1017,15 @@ static void prim_second(EvalState & state, const PosIdx pos, Value * * args, Val static void prim_derivationStrict(EvalState & state, const PosIdx pos, Value * * args, Value & v) { using nlohmann::json; - state.forceAttrs(*args[0], pos); + state.forceAttrs(*args[0], pos, "while evaluating the argument passed to builtins.derivationStrict"); /* Figure out the name first (for stack backtraces). */ - Bindings::iterator attr = getAttr( - state, - "derivationStrict", - state.sName, - args[0]->attrs, - pos - ); + Bindings::iterator attr = getAttr(state, state.sName, args[0]->attrs, "in the attrset passed as argument to builtins.derivationStrict"); std::string drvName; const auto posDrvName = attr->pos; try { - drvName = state.forceStringNoCtx(*attr->value, pos); + drvName = state.forceStringNoCtx(*attr->value, pos, "while evaluating the `name` attribute passed to builtins.derivationStrict"); } catch (Error & e) { e.addTrace(state.positions[posDrvName], "while evaluating the derivation attribute 'name'"); throw; @@ -1047,14 +1034,14 @@ static void prim_derivationStrict(EvalState & state, const PosIdx pos, Value * * /* Check whether attributes should be passed as a JSON file. */ std::optional<json> jsonObject; attr = args[0]->attrs->find(state.sStructuredAttrs); - if (attr != args[0]->attrs->end() && state.forceBool(*attr->value, pos)) + if (attr != args[0]->attrs->end() && state.forceBool(*attr->value, pos, "while evaluating the `__structuredAttrs` attribute passed to builtins.derivationStrict")) jsonObject = json::object(); /* Check whether null attributes should be ignored. */ bool ignoreNulls = false; attr = args[0]->attrs->find(state.sIgnoreNulls); if (attr != args[0]->attrs->end()) - ignoreNulls = state.forceBool(*attr->value, pos); + ignoreNulls = state.forceBool(*attr->value, pos, "while evaluating the `__ignoreNulls` attribute passed to builtins.derivationStrict"); /* Build the derivation expression by processing the attributes. */ Derivation drv; @@ -1121,13 +1108,15 @@ static void prim_derivationStrict(EvalState & state, const PosIdx pos, Value * * } if (i->name == state.sContentAddressed) { - contentAddressed = state.forceBool(*i->value, pos); + contentAddressed = state.forceBool(*i->value, pos, + "while evaluating the `__contentAddressed` attribute passed to builtins.derivationStrict"); if (contentAddressed) settings.requireExperimentalFeature(Xp::CaDerivations); } else if (i->name == state.sImpure) { - isImpure = state.forceBool(*i->value, pos); + isImpure = state.forceBool(*i->value, pos, + "while evaluating the 'impure' attribute passed to builtins.derivationStrict"); if (isImpure) settings.requireExperimentalFeature(Xp::ImpureDerivations); } @@ -1135,9 +1124,11 @@ static void prim_derivationStrict(EvalState & state, const PosIdx pos, Value * * /* The `args' attribute is special: it supplies the command-line arguments to the builder. */ else if (i->name == state.sArgs) { - state.forceList(*i->value, pos); + state.forceList(*i->value, pos, + "while evaluating the `args` attribute passed to builtins.derivationStrict"); for (auto elem : i->value->listItems()) { - auto s = state.coerceToString(posDrvName, *elem, context, true).toOwned(); + auto s = state.coerceToString(posDrvName, *elem, context, true, + "while evaluating an element of the `args` argument passed to builtins.derivationStrict").toOwned(); drv.args.push_back(s); } } @@ -1153,26 +1144,26 @@ static void prim_derivationStrict(EvalState & state, const PosIdx pos, Value * * (*jsonObject)[key] = printValueAsJSON(state, true, *i->value, pos, context); if (i->name == state.sBuilder) - drv.builder = state.forceString(*i->value, context, posDrvName); + drv.builder = state.forceString(*i->value, context, posDrvName, "while evaluating the `builder` attribute passed to builtins.derivationStrict"); else if (i->name == state.sSystem) - drv.platform = state.forceStringNoCtx(*i->value, posDrvName); + drv.platform = state.forceStringNoCtx(*i->value, posDrvName, "while evaluating the `system` attribute passed to builtins.derivationStrict"); else if (i->name == state.sOutputHash) - outputHash = state.forceStringNoCtx(*i->value, posDrvName); + outputHash = state.forceStringNoCtx(*i->value, posDrvName, "while evaluating the `outputHash` attribute passed to builtins.derivationStrict"); else if (i->name == state.sOutputHashAlgo) - outputHashAlgo = state.forceStringNoCtx(*i->value, posDrvName); + outputHashAlgo = state.forceStringNoCtx(*i->value, posDrvName, "while evaluating the `outputHashAlgo` attribute passed to builtins.derivationStrict"); else if (i->name == state.sOutputHashMode) - handleHashMode(state.forceStringNoCtx(*i->value, posDrvName)); + handleHashMode(state.forceStringNoCtx(*i->value, posDrvName, "while evaluating the `outputHashMode` attribute passed to builtins.derivationStrict")); else if (i->name == state.sOutputs) { /* Require ‘outputs’ to be a list of strings. */ - state.forceList(*i->value, posDrvName); + state.forceList(*i->value, posDrvName, "while evaluating the `outputs` attribute passed to builtins.derivationStrict"); Strings ss; for (auto elem : i->value->listItems()) - ss.emplace_back(state.forceStringNoCtx(*elem, posDrvName)); + ss.emplace_back(state.forceStringNoCtx(*elem, posDrvName, "while evaluating an element of the `outputs` attribute passed to builtins.derivationStrict")); handleOutputs(ss); } } else { - auto s = state.coerceToString(i->pos, *i->value, context, true).toOwned(); + auto s = state.coerceToString(i->pos, *i->value, context, true, "while evaluating an attribute passed to builtins.derivationStrict").toOwned(); drv.env.emplace(key, s); if (i->name == state.sBuilder) drv.builder = std::move(s); else if (i->name == state.sSystem) drv.platform = std::move(s); @@ -1186,9 +1177,9 @@ static void prim_derivationStrict(EvalState & state, const PosIdx pos, Value * * } } catch (Error & e) { - e.addTrace(state.positions[posDrvName], - "while evaluating the attribute '%1%' of the derivation '%2%'", - key, drvName); + e.addTrace(nullptr, + hintfmt("while evaluating the attribute '%1%' of the derivation '%2%'", key, drvName), + true); throw; } } @@ -1376,7 +1367,7 @@ static RegisterPrimOp primop_derivationStrict(RegisterPrimOp::Info { ‘out’. */ static void prim_placeholder(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - v.mkString(hashPlaceholder(state.forceStringNoCtx(*args[0], pos))); + v.mkString(hashPlaceholder(state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.placeholder"))); } static RegisterPrimOp primop_placeholder({ @@ -1400,7 +1391,7 @@ static RegisterPrimOp primop_placeholder({ static void prim_toPath(EvalState & state, const PosIdx pos, Value * * args, Value & v) { PathSet context; - Path path = state.coerceToPath(pos, *args[0], context); + Path path = state.coerceToPath(pos, *args[0], context, "while evaluating the first argument passed to builtins.toPath"); v.mkString(canonPath(path), context); } @@ -1431,7 +1422,7 @@ static void prim_storePath(EvalState & state, const PosIdx pos, Value * * args, })); PathSet context; - Path path = state.checkSourcePath(state.coerceToPath(pos, *args[0], context)); + Path path = state.checkSourcePath(state.coerceToPath(pos, *args[0], context, "while evaluating the first argument passed to builtins.storePath")); /* Resolve symlinks in ‘path’, unless ‘path’ itself is a symlink directly in the store. The latter condition is necessary so e.g. nix-push does the right thing. */ @@ -1501,7 +1492,7 @@ static RegisterPrimOp primop_pathExists({ static void prim_baseNameOf(EvalState & state, const PosIdx pos, Value * * args, Value & v) { PathSet context; - v.mkString(baseNameOf(*state.coerceToString(pos, *args[0], context, false, false)), context); + v.mkString(baseNameOf(*state.coerceToString(pos, *args[0], context, false, false, "while evaluating the first argument passed to builtins.baseNameOf")), context); } static RegisterPrimOp primop_baseNameOf({ @@ -1521,7 +1512,7 @@ static RegisterPrimOp primop_baseNameOf({ static void prim_dirOf(EvalState & state, const PosIdx pos, Value * * args, Value & v) { PathSet context; - auto path = state.coerceToString(pos, *args[0], context, false, false); + auto path = state.coerceToString(pos, *args[0], context, false, false, "while evaluating the first argument passed to builtins.dirOf"); auto dir = dirOf(*path); if (args[0]->type() == nPath) v.mkPath(dir); else v.mkString(dir, context); } @@ -1572,28 +1563,23 @@ static RegisterPrimOp primop_readFile({ which are desugared to 'findFile __nixPath "x"'. */ static void prim_findFile(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceList(*args[0], pos); + state.forceList(*args[0], pos, "while evaluating the first argument passed to builtins.findFile"); SearchPath searchPath; for (auto v2 : args[0]->listItems()) { - state.forceAttrs(*v2, pos); + state.forceAttrs(*v2, pos, "while evaluating an element of the list passed to builtins.findFile"); std::string prefix; Bindings::iterator i = v2->attrs->find(state.sPrefix); if (i != v2->attrs->end()) - prefix = state.forceStringNoCtx(*i->value, pos); + prefix = state.forceStringNoCtx(*i->value, pos, "while evaluating the `prefix` attribute of an element of the list passed to builtins.findFile"); - i = getAttr( - state, - "findFile", - state.sPath, - v2->attrs, - pos - ); + i = getAttr(state, state.sPath, v2->attrs, "in an element of the __nixPath"); PathSet context; - auto path = state.coerceToString(pos, *i->value, context, false, false).toOwned(); + auto path = state.coerceToString(pos, *i->value, context, false, false, + "while evaluating the `path` attribute of an element of the list passed to builtins.findFile").toOwned(); try { auto rewrites = state.realiseContext(context); @@ -1608,7 +1594,7 @@ static void prim_findFile(EvalState & state, const PosIdx pos, Value * * args, V searchPath.emplace_back(prefix, path); } - auto path = state.forceStringNoCtx(*args[1], pos); + auto path = state.forceStringNoCtx(*args[1], pos, "while evaluating the second argument passed to builtins.findFile"); v.mkPath(state.checkSourcePath(state.findFile(searchPath, path, pos))); } @@ -1622,7 +1608,7 @@ static RegisterPrimOp primop_findFile(RegisterPrimOp::Info { /* Return the cryptographic hash of a file in base-16. */ static void prim_hashFile(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - auto type = state.forceStringNoCtx(*args[0], pos); + auto type = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.hashFile"); std::optional<HashType> ht = parseHashType(type); if (!ht) state.debugThrowLastTrace(Error({ @@ -1829,7 +1815,7 @@ static RegisterPrimOp primop_toJSON({ /* Parse a JSON string to a value. */ static void prim_fromJSON(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - auto s = state.forceStringNoCtx(*args[0], pos); + auto s = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.fromJSON"); try { parseJSON(state, s, v); } catch (JSONParseError &e) { @@ -1858,8 +1844,8 @@ static RegisterPrimOp primop_fromJSON({ static void prim_toFile(EvalState & state, const PosIdx pos, Value * * args, Value & v) { PathSet context; - std::string name(state.forceStringNoCtx(*args[0], pos)); - std::string contents(state.forceString(*args[1], context, pos)); + std::string name(state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.toFile")); + std::string contents(state.forceString(*args[1], context, pos, "while evaluating the second argument passed to builtins.toFile")); StorePathSet refs; @@ -2016,7 +2002,7 @@ static void addPath( Value res; state.callFunction(*filterFun, 2, args, res, pos); - return state.forceBool(res, pos); + return state.forceBool(res, pos, "while evaluating the return value of the path filter function"); }) : defaultPathFilter; std::optional<StorePath> expectedStorePath; @@ -2042,17 +2028,8 @@ static void addPath( static void prim_filterSource(EvalState & state, const PosIdx pos, Value * * args, Value & v) { PathSet context; - Path path = state.coerceToPath(pos, *args[1], context); - - state.forceValue(*args[0], pos); - if (args[0]->type() != nFunction) - state.debugThrowLastTrace(TypeError({ - .msg = hintfmt( - "first argument in call to 'filterSource' is not a function but %1%", - showType(*args[0])), - .errPos = state.positions[pos] - })); - + Path path = state.coerceToPath(pos, *args[1], context, "while evaluating the second argument (the path to filter) passed to builtins.filterSource"); + state.forceFunction(*args[0], pos, "while evaluating the first argument passed to builtins.filterSource"); addPath(state, pos, std::string(baseNameOf(path)), path, args[0], FileIngestionMethod::Recursive, std::nullopt, v, context); } @@ -2113,7 +2090,7 @@ static RegisterPrimOp primop_filterSource({ static void prim_path(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceAttrs(*args[0], pos); + state.forceAttrs(*args[0], pos, "while evaluating the argument passed to builtins.path"); Path path; std::string name; Value * filterFun = nullptr; @@ -2124,16 +2101,15 @@ static void prim_path(EvalState & state, const PosIdx pos, Value * * args, Value for (auto & attr : *args[0]->attrs) { auto n = state.symbols[attr.name]; if (n == "path") - path = state.coerceToPath(attr.pos, *attr.value, context); + path = state.coerceToPath(attr.pos, *attr.value, context, "while evaluating the `path` attribute passed to builtins.path"); else if (attr.name == state.sName) - name = state.forceStringNoCtx(*attr.value, attr.pos); - else if (n == "filter") { - state.forceValue(*attr.value, pos); - filterFun = attr.value; - } else if (n == "recursive") - method = FileIngestionMethod { state.forceBool(*attr.value, attr.pos) }; + name = state.forceStringNoCtx(*attr.value, attr.pos, "while evaluating the `name` attribute passed to builtins.path"); + else if (n == "filter") + state.forceFunction(*(filterFun = attr.value), attr.pos, "while evaluating the `filter` parameter passed to builtins.path"); + else if (n == "recursive") + method = FileIngestionMethod { state.forceBool(*attr.value, attr.pos, "while evaluating the `recursive` attribute passed to builtins.path") }; else if (n == "sha256") - expectedHash = newHashAllowEmpty(state.forceStringNoCtx(*attr.value, attr.pos), htSHA256); + expectedHash = newHashAllowEmpty(state.forceStringNoCtx(*attr.value, attr.pos, "while evaluating the `sha256` attribute passed to builtins.path"), htSHA256); else state.debugThrowLastTrace(EvalError({ .msg = hintfmt("unsupported argument '%1%' to 'addPath'", state.symbols[attr.name]), @@ -2142,7 +2118,7 @@ static void prim_path(EvalState & state, const PosIdx pos, Value * * args, Value } if (path.empty()) state.debugThrowLastTrace(EvalError({ - .msg = hintfmt("'path' required"), + .msg = hintfmt("missing required 'path' attribute in the first argument to builtins.path"), .errPos = state.positions[pos] })); if (name.empty()) @@ -2196,7 +2172,7 @@ static RegisterPrimOp primop_path({ strings. */ static void prim_attrNames(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceAttrs(*args[0], pos); + state.forceAttrs(*args[0], pos, "while evaluating the argument passed to builtins.attrNames"); state.mkList(v, args[0]->attrs->size()); @@ -2223,7 +2199,7 @@ static RegisterPrimOp primop_attrNames({ order as attrNames. */ static void prim_attrValues(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceAttrs(*args[0], pos); + state.forceAttrs(*args[0], pos, "while evaluating the argument passed to builtins.attrValues"); state.mkList(v, args[0]->attrs->size()); @@ -2255,14 +2231,13 @@ static RegisterPrimOp primop_attrValues({ /* Dynamic version of the `.' operator. */ void prim_getAttr(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - auto attr = state.forceStringNoCtx(*args[0], pos); - state.forceAttrs(*args[1], pos); + auto attr = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.getAttr"); + state.forceAttrs(*args[1], pos, "while evaluating the second argument passed to builtins.getAttr"); Bindings::iterator i = getAttr( state, - "getAttr", state.symbols.create(attr), args[1]->attrs, - pos + "in the attribute set under consideration" ); // !!! add to stack trace? if (state.countCalls && i->pos) state.attrSelects[i->pos]++; @@ -2285,8 +2260,8 @@ static RegisterPrimOp primop_getAttr({ /* Return position information of the specified attribute. */ static void prim_unsafeGetAttrPos(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - auto attr = state.forceStringNoCtx(*args[0], pos); - state.forceAttrs(*args[1], pos); + auto attr = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.unsafeGetAttrPos"); + state.forceAttrs(*args[1], pos, "while evaluating the second argument passed to builtins.unsafeGetAttrPos"); Bindings::iterator i = args[1]->attrs->find(state.symbols.create(attr)); if (i == args[1]->attrs->end()) v.mkNull(); @@ -2303,8 +2278,8 @@ static RegisterPrimOp primop_unsafeGetAttrPos(RegisterPrimOp::Info { /* Dynamic version of the `?' operator. */ static void prim_hasAttr(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - auto attr = state.forceStringNoCtx(*args[0], pos); - state.forceAttrs(*args[1], pos); + auto attr = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.hasAttr"); + state.forceAttrs(*args[1], pos, "while evaluating the second argument passed to builtins.hasAttr"); v.mkBool(args[1]->attrs->find(state.symbols.create(attr)) != args[1]->attrs->end()); } @@ -2337,8 +2312,8 @@ static RegisterPrimOp primop_isAttrs({ static void prim_removeAttrs(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceAttrs(*args[0], pos); - state.forceList(*args[1], pos); + state.forceAttrs(*args[0], pos, "while evaluating the first argument passed to builtins.removeAttrs"); + state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.removeAttrs"); /* Get the attribute names to be removed. We keep them as Attrs instead of Symbols so std::set_difference @@ -2346,7 +2321,7 @@ static void prim_removeAttrs(EvalState & state, const PosIdx pos, Value * * args boost::container::small_vector<Attr, 64> names; names.reserve(args[1]->listSize()); for (auto elem : args[1]->listItems()) { - state.forceStringNoCtx(*elem, pos); + state.forceStringNoCtx(*elem, pos, "while evaluating the values of the second argument passed to builtins.removeAttrs"); names.emplace_back(state.symbols.create(elem->string.s), nullptr); } std::sort(names.begin(), names.end()); @@ -2385,34 +2360,22 @@ static RegisterPrimOp primop_removeAttrs({ name, the first takes precedence. */ static void prim_listToAttrs(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceList(*args[0], pos); + state.forceList(*args[0], pos, "while evaluating the argument passed to builtins.listToAttrs"); auto attrs = state.buildBindings(args[0]->listSize()); std::set<Symbol> seen; for (auto v2 : args[0]->listItems()) { - state.forceAttrs(*v2, pos); + state.forceAttrs(*v2, pos, "while evaluating an element of the list passed to builtins.listToAttrs"); - Bindings::iterator j = getAttr( - state, - "listToAttrs", - state.sName, - v2->attrs, - pos - ); + Bindings::iterator j = getAttr(state, state.sName, v2->attrs, "in a {name=...; value=...;} pair"); - auto name = state.forceStringNoCtx(*j->value, j->pos); + auto name = state.forceStringNoCtx(*j->value, j->pos, "while evaluating the `name` attribute of an element of the list passed to builtins.listToAttrs"); auto sym = state.symbols.create(name); if (seen.insert(sym).second) { - Bindings::iterator j2 = getAttr( - state, - "listToAttrs", - state.sValue, - v2->attrs, - pos - ); + Bindings::iterator j2 = getAttr(state, state.sValue, v2->attrs, "in a {name=...; value=...;} pair"); attrs.insert(sym, j2->value, j2->pos); } } @@ -2453,8 +2416,8 @@ static RegisterPrimOp primop_listToAttrs({ static void prim_intersectAttrs(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceAttrs(*args[0], pos); - state.forceAttrs(*args[1], pos); + state.forceAttrs(*args[0], pos, "while evaluating the first argument passed to builtins.intersectAttrs"); + state.forceAttrs(*args[1], pos, "while evaluating the second argument passed to builtins.intersectAttrs"); Bindings &left = *args[0]->attrs; Bindings &right = *args[1]->attrs; @@ -2531,14 +2494,14 @@ static RegisterPrimOp primop_intersectAttrs({ static void prim_catAttrs(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - auto attrName = state.symbols.create(state.forceStringNoCtx(*args[0], pos)); - state.forceList(*args[1], pos); + auto attrName = state.symbols.create(state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.catAttrs")); + state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.catAttrs"); Value * res[args[1]->listSize()]; unsigned int found = 0; for (auto v2 : args[1]->listItems()) { - state.forceAttrs(*v2, pos); + state.forceAttrs(*v2, pos, "while evaluating an element in the list passed as second argument to builtins.catAttrs"); Bindings::iterator i = v2->attrs->find(attrName); if (i != v2->attrs->end()) res[found++] = i->value; @@ -2611,7 +2574,7 @@ static RegisterPrimOp primop_functionArgs({ /* */ static void prim_mapAttrs(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceAttrs(*args[1], pos); + state.forceAttrs(*args[1], pos, "while evaluating the second argument passed to builtins.mapAttrs"); auto attrs = state.buildBindings(args[1]->attrs->size()); @@ -2652,15 +2615,15 @@ static void prim_zipAttrsWith(EvalState & state, const PosIdx pos, Value * * arg std::map<Symbol, std::pair<size_t, Value * *>> attrsSeen; - state.forceFunction(*args[0], pos); - state.forceList(*args[1], pos); + state.forceFunction(*args[0], pos, "while evaluating the first argument passed to builtins.zipAttrsWith"); + state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.zipAttrsWith"); const auto listSize = args[1]->listSize(); const auto listElems = args[1]->listElems(); for (unsigned int n = 0; n < listSize; ++n) { Value * vElem = listElems[n]; try { - state.forceAttrs(*vElem, noPos); + state.forceAttrs(*vElem, noPos, "while evaluating a value of the list passed as second argument to builtins.zipAttrsWith"); for (auto & attr : *vElem->attrs) attrsSeen[attr.name].first++; } catch (TypeError & e) { @@ -2750,7 +2713,7 @@ static RegisterPrimOp primop_isList({ static void elemAt(EvalState & state, const PosIdx pos, Value & list, int n, Value & v) { - state.forceList(list, pos); + state.forceList(list, pos, "while evaluating the first argument passed to builtins.elemAt"); if (n < 0 || (unsigned int) n >= list.listSize()) state.debugThrowLastTrace(Error({ .msg = hintfmt("list index %1% is out of bounds", n), @@ -2763,7 +2726,7 @@ static void elemAt(EvalState & state, const PosIdx pos, Value & list, int n, Val /* Return the n-1'th element of a list. */ static void prim_elemAt(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - elemAt(state, pos, *args[0], state.forceInt(*args[1], pos), v); + elemAt(state, pos, *args[0], state.forceInt(*args[1], pos, "while evaluating the second argument passed to builtins.elemAt"), v); } static RegisterPrimOp primop_elemAt({ @@ -2798,7 +2761,7 @@ static RegisterPrimOp primop_head({ don't want to use it! */ static void prim_tail(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceList(*args[0], pos); + state.forceList(*args[0], pos, "while evaluating the first argument passed to builtins.tail"); if (args[0]->listSize() == 0) state.debugThrowLastTrace(Error({ .msg = hintfmt("'tail' called on an empty list"), @@ -2829,10 +2792,16 @@ static RegisterPrimOp primop_tail({ /* Apply a function to every element of a list. */ static void prim_map(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceList(*args[1], pos); + state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.map"); - state.mkList(v, args[1]->listSize()); + if (args[1]->listSize() == 0) { + v = *args[1]; + return; + } + state.forceFunction(*args[0], pos, "while evaluating the first argument passed to builtins.map"); + + state.mkList(v, args[1]->listSize()); for (unsigned int n = 0; n < v.listSize(); ++n) (v.listElems()[n] = state.allocValue())->mkApp( args[0], args[1]->listElems()[n]); @@ -2859,8 +2828,14 @@ static RegisterPrimOp primop_map({ returns true. */ static void prim_filter(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceFunction(*args[0], pos); - state.forceList(*args[1], pos); + state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.filter"); + + if (args[1]->listSize() == 0) { + v = *args[1]; + return; + } + + state.forceFunction(*args[0], pos, "while evaluating the first argument passed to builtins.filter"); // FIXME: putting this on the stack is risky. Value * vs[args[1]->listSize()]; @@ -2870,7 +2845,7 @@ static void prim_filter(EvalState & state, const PosIdx pos, Value * * args, Val for (unsigned int n = 0; n < args[1]->listSize(); ++n) { Value res; state.callFunction(*args[0], *args[1]->listElems()[n], res, noPos); - if (state.forceBool(res, pos)) + if (state.forceBool(res, pos, "while evaluating the return value of the filtering function passed to builtins.filter")) vs[k++] = args[1]->listElems()[n]; else same = false; @@ -2898,9 +2873,9 @@ static RegisterPrimOp primop_filter({ static void prim_elem(EvalState & state, const PosIdx pos, Value * * args, Value & v) { bool res = false; - state.forceList(*args[1], pos); + state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.elem"); for (auto elem : args[1]->listItems()) - if (state.eqValues(*args[0], *elem)) { + if (state.eqValues(*args[0], *elem, pos, "while searching for the presence of the given element in the list")) { res = true; break; } @@ -2920,8 +2895,8 @@ static RegisterPrimOp primop_elem({ /* Concatenate a list of lists. */ static void prim_concatLists(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceList(*args[0], pos); - state.concatLists(v, args[0]->listSize(), args[0]->listElems(), pos); + state.forceList(*args[0], pos, "while evaluating the first argument passed to builtins.concatLists"); + state.concatLists(v, args[0]->listSize(), args[0]->listElems(), pos, "while evaluating a value of the list passed to builtins.concatLists"); } static RegisterPrimOp primop_concatLists({ @@ -2936,7 +2911,7 @@ static RegisterPrimOp primop_concatLists({ /* Return the length of a list. This is an O(1) time operation. */ static void prim_length(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceList(*args[0], pos); + state.forceList(*args[0], pos, "while evaluating the first argument passed to builtins.length"); v.mkInt(args[0]->listSize()); } @@ -2953,8 +2928,8 @@ static RegisterPrimOp primop_length({ right. The operator is applied strictly. */ static void prim_foldlStrict(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceFunction(*args[0], pos); - state.forceList(*args[2], pos); + state.forceFunction(*args[0], pos, "while evaluating the first argument passed to builtins.foldlStrict"); + state.forceList(*args[2], pos, "while evaluating the third argument passed to builtins.foldlStrict"); if (args[2]->listSize()) { Value * vCur = args[1]; @@ -2986,13 +2961,13 @@ static RegisterPrimOp primop_foldlStrict({ static void anyOrAll(bool any, EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceFunction(*args[0], pos); - state.forceList(*args[1], pos); + state.forceFunction(*args[0], pos, std::string("while evaluating the first argument passed to builtins.") + (any ? "any" : "all")); + state.forceList(*args[1], pos, std::string("while evaluating the second argument passed to builtins.") + (any ? "any" : "all")); Value vTmp; for (auto elem : args[1]->listItems()) { state.callFunction(*args[0], *elem, vTmp, pos); - bool res = state.forceBool(vTmp, pos); + bool res = state.forceBool(vTmp, pos, std::string("while evaluating the return value of the function passed to builtins.") + (any ? "any" : "all")); if (res == any) { v.mkBool(any); return; @@ -3035,7 +3010,7 @@ static RegisterPrimOp primop_all({ static void prim_genList(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - auto len = state.forceInt(*args[1], pos); + auto len = state.forceInt(*args[1], pos, "while evaluating the second argument passed to builtins.genList"); if (len < 0) state.debugThrowLastTrace(EvalError({ @@ -3073,10 +3048,16 @@ static void prim_lessThan(EvalState & state, const PosIdx pos, Value * * args, V static void prim_sort(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceFunction(*args[0], pos); - state.forceList(*args[1], pos); + state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.sort"); auto len = args[1]->listSize(); + if (len == 0) { + v = *args[1]; + return; + } + + state.forceFunction(*args[0], pos, "while evaluating the first argument passed to builtins.sort"); + state.mkList(v, len); for (unsigned int n = 0; n < len; ++n) { state.forceValue(*args[1]->listElems()[n], pos); @@ -3087,12 +3068,12 @@ static void prim_sort(EvalState & state, const PosIdx pos, Value * * args, Value /* Optimization: if the comparator is lessThan, bypass callFunction. */ if (args[0]->isPrimOp() && args[0]->primOp->fun == prim_lessThan) - return CompareValues(state)(a, b); + return CompareValues(state, noPos, "while evaluating the ordering function passed to builtins.sort")(a, b); Value * vs[] = {a, b}; Value vBool; - state.callFunction(*args[0], 2, vs, vBool, pos); - return state.forceBool(vBool, pos); + state.callFunction(*args[0], 2, vs, vBool, noPos); + return state.forceBool(vBool, pos, "while evaluating the return value of the sorting function passed to builtins.sort"); }; /* FIXME: std::sort can segfault if the comparator is not a strict @@ -3124,8 +3105,8 @@ static RegisterPrimOp primop_sort({ static void prim_partition(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceFunction(*args[0], pos); - state.forceList(*args[1], pos); + state.forceFunction(*args[0], pos, "while evaluating the first argument passed to builtins.partition"); + state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.partition"); auto len = args[1]->listSize(); @@ -3136,7 +3117,7 @@ static void prim_partition(EvalState & state, const PosIdx pos, Value * * args, state.forceValue(*vElem, pos); Value res; state.callFunction(*args[0], *vElem, res, pos); - if (state.forceBool(res, pos)) + if (state.forceBool(res, pos, "while evaluating the return value of the partition function passed to builtins.partition")) right.push_back(vElem); else wrong.push_back(vElem); @@ -3184,15 +3165,15 @@ static RegisterPrimOp primop_partition({ static void prim_groupBy(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceFunction(*args[0], pos); - state.forceList(*args[1], pos); + state.forceFunction(*args[0], pos, "while evaluating the first argument passed to builtins.groupBy"); + state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.groupBy"); ValueVectorMap attrs; for (auto vElem : args[1]->listItems()) { Value res; state.callFunction(*args[0], *vElem, res, pos); - auto name = state.forceStringNoCtx(res, pos); + auto name = state.forceStringNoCtx(res, pos, "while evaluating the return value of the grouping function passed to builtins.groupBy"); auto sym = state.symbols.create(name); auto vector = attrs.try_emplace(sym, ValueVector()).first; vector->second.push_back(vElem); @@ -3236,8 +3217,8 @@ static RegisterPrimOp primop_groupBy({ static void prim_concatMap(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceFunction(*args[0], pos); - state.forceList(*args[1], pos); + state.forceFunction(*args[0], pos, "while evaluating the first argument passed to builtins.concatMap"); + state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.concatMap"); auto nrLists = args[1]->listSize(); Value lists[nrLists]; @@ -3247,7 +3228,7 @@ static void prim_concatMap(EvalState & state, const PosIdx pos, Value * * args, Value * vElem = args[1]->listElems()[n]; state.callFunction(*args[0], *vElem, lists[n], pos); try { - state.forceList(lists[n], lists[n].determinePos(args[0]->determinePos(pos))); + state.forceList(lists[n], lists[n].determinePos(args[0]->determinePos(pos)), "while evaluating the return value of the function passed to buitlins.concatMap"); } catch (TypeError &e) { e.addTrace(state.positions[pos], hintfmt("while invoking '%s'", "concatMap")); state.debugThrowLastTrace(e); @@ -3286,9 +3267,11 @@ static void prim_add(EvalState & state, const PosIdx pos, Value * * args, Value state.forceValue(*args[0], pos); state.forceValue(*args[1], pos); if (args[0]->type() == nFloat || args[1]->type() == nFloat) - v.mkFloat(state.forceFloat(*args[0], pos) + state.forceFloat(*args[1], pos)); + v.mkFloat(state.forceFloat(*args[0], pos, "while evaluating the first argument of the addition") + + state.forceFloat(*args[1], pos, "while evaluating the second argument of the addition")); else - v.mkInt(state.forceInt(*args[0], pos) + state.forceInt(*args[1], pos)); + v.mkInt( state.forceInt(*args[0], pos, "while evaluating the first argument of the addition") + + state.forceInt(*args[1], pos, "while evaluating the second argument of the addition")); } static RegisterPrimOp primop_add({ @@ -3305,9 +3288,11 @@ static void prim_sub(EvalState & state, const PosIdx pos, Value * * args, Value state.forceValue(*args[0], pos); state.forceValue(*args[1], pos); if (args[0]->type() == nFloat || args[1]->type() == nFloat) - v.mkFloat(state.forceFloat(*args[0], pos) - state.forceFloat(*args[1], pos)); + v.mkFloat(state.forceFloat(*args[0], pos, "while evaluating the first argument of the subtraction") + - state.forceFloat(*args[1], pos, "while evaluating the second argument of the subtraction")); else - v.mkInt(state.forceInt(*args[0], pos) - state.forceInt(*args[1], pos)); + v.mkInt( state.forceInt(*args[0], pos, "while evaluating the first argument of the subtraction") + - state.forceInt(*args[1], pos, "while evaluating the second argument of the subtraction")); } static RegisterPrimOp primop_sub({ @@ -3324,9 +3309,11 @@ static void prim_mul(EvalState & state, const PosIdx pos, Value * * args, Value state.forceValue(*args[0], pos); state.forceValue(*args[1], pos); if (args[0]->type() == nFloat || args[1]->type() == nFloat) - v.mkFloat(state.forceFloat(*args[0], pos) * state.forceFloat(*args[1], pos)); + v.mkFloat(state.forceFloat(*args[0], pos, "while evaluating the first of the multiplication") + * state.forceFloat(*args[1], pos, "while evaluating the second argument of the multiplication")); else - v.mkInt(state.forceInt(*args[0], pos) * state.forceInt(*args[1], pos)); + v.mkInt( state.forceInt(*args[0], pos, "while evaluating the first argument of the multiplication") + * state.forceInt(*args[1], pos, "while evaluating the second argument of the multiplication")); } static RegisterPrimOp primop_mul({ @@ -3343,7 +3330,7 @@ static void prim_div(EvalState & state, const PosIdx pos, Value * * args, Value state.forceValue(*args[0], pos); state.forceValue(*args[1], pos); - NixFloat f2 = state.forceFloat(*args[1], pos); + NixFloat f2 = state.forceFloat(*args[1], pos, "while evaluating the second operand of the division"); if (f2 == 0) state.debugThrowLastTrace(EvalError({ .msg = hintfmt("division by zero"), @@ -3351,10 +3338,10 @@ static void prim_div(EvalState & state, const PosIdx pos, Value * * args, Value })); if (args[0]->type() == nFloat || args[1]->type() == nFloat) { - v.mkFloat(state.forceFloat(*args[0], pos) / state.forceFloat(*args[1], pos)); + v.mkFloat(state.forceFloat(*args[0], pos, "while evaluating the first operand of the division") / f2); } else { - NixInt i1 = state.forceInt(*args[0], pos); - NixInt i2 = state.forceInt(*args[1], pos); + NixInt i1 = state.forceInt(*args[0], pos, "while evaluating the first operand of the division"); + NixInt i2 = state.forceInt(*args[1], pos, "while evaluating the second operand of the division"); /* Avoid division overflow as it might raise SIGFPE. */ if (i1 == std::numeric_limits<NixInt>::min() && i2 == -1) state.debugThrowLastTrace(EvalError({ @@ -3377,7 +3364,8 @@ static RegisterPrimOp primop_div({ static void prim_bitAnd(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - v.mkInt(state.forceInt(*args[0], pos) & state.forceInt(*args[1], pos)); + v.mkInt(state.forceInt(*args[0], pos, "while evaluating the first argument passed to builtins.bitAnd") + & state.forceInt(*args[1], pos, "while evaluating the second argument passed to builtins.bitAnd")); } static RegisterPrimOp primop_bitAnd({ @@ -3391,7 +3379,8 @@ static RegisterPrimOp primop_bitAnd({ static void prim_bitOr(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - v.mkInt(state.forceInt(*args[0], pos) | state.forceInt(*args[1], pos)); + v.mkInt(state.forceInt(*args[0], pos, "while evaluating the first argument passed to builtins.bitOr") + | state.forceInt(*args[1], pos, "while evaluating the second argument passed to builtins.bitOr")); } static RegisterPrimOp primop_bitOr({ @@ -3405,7 +3394,8 @@ static RegisterPrimOp primop_bitOr({ static void prim_bitXor(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - v.mkInt(state.forceInt(*args[0], pos) ^ state.forceInt(*args[1], pos)); + v.mkInt(state.forceInt(*args[0], pos, "while evaluating the first argument passed to builtins.bitXor") + ^ state.forceInt(*args[1], pos, "while evaluating the second argument passed to builtins.bitXor")); } static RegisterPrimOp primop_bitXor({ @@ -3421,7 +3411,8 @@ static void prim_lessThan(EvalState & state, const PosIdx pos, Value * * args, V { state.forceValue(*args[0], pos); state.forceValue(*args[1], pos); - CompareValues comp{state}; + // pos is exact here, no need for a message. + CompareValues comp(state, pos, ""); v.mkBool(comp(args[0], args[1])); } @@ -3448,7 +3439,7 @@ static RegisterPrimOp primop_lessThan({ static void prim_toString(EvalState & state, const PosIdx pos, Value * * args, Value & v) { PathSet context; - auto s = state.coerceToString(pos, *args[0], context, true, false); + auto s = state.coerceToString(pos, *args[0], context, true, false, "while evaluating the first argument passed to builtins.toString"); v.mkString(*s, context); } @@ -3482,10 +3473,10 @@ static RegisterPrimOp primop_toString({ non-negative. */ static void prim_substring(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - int start = state.forceInt(*args[0], pos); - int len = state.forceInt(*args[1], pos); + int start = state.forceInt(*args[0], pos, "while evaluating the first argument (the start offset) passed to builtins.substring"); + int len = state.forceInt(*args[1], pos, "while evaluating the second argument (the substring length) passed to builtins.substring"); PathSet context; - auto s = state.coerceToString(pos, *args[2], context); + auto s = state.coerceToString(pos, *args[2], context, "while evaluating the third argument (the string) passed to builtins.substring"); if (start < 0) state.debugThrowLastTrace(EvalError({ @@ -3519,7 +3510,7 @@ static RegisterPrimOp primop_substring({ static void prim_stringLength(EvalState & state, const PosIdx pos, Value * * args, Value & v) { PathSet context; - auto s = state.coerceToString(pos, *args[0], context); + auto s = state.coerceToString(pos, *args[0], context, "while evaluating the argument passed to builtins.stringLength"); v.mkInt(s->size()); } @@ -3536,7 +3527,7 @@ static RegisterPrimOp primop_stringLength({ /* Return the cryptographic hash of a string in base-16. */ static void prim_hashString(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - auto type = state.forceStringNoCtx(*args[0], pos); + auto type = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.hashString"); std::optional<HashType> ht = parseHashType(type); if (!ht) state.debugThrowLastTrace(Error({ @@ -3545,7 +3536,7 @@ static void prim_hashString(EvalState & state, const PosIdx pos, Value * * args, })); PathSet context; // discarded - auto s = state.forceString(*args[1], context, pos); + auto s = state.forceString(*args[1], context, pos, "while evaluating the second argument passed to builtins.hashString"); v.mkString(hashString(*ht, s).to_string(Base16, false)); } @@ -3584,14 +3575,14 @@ std::shared_ptr<RegexCache> makeRegexCache() void prim_match(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - auto re = state.forceStringNoCtx(*args[0], pos); + auto re = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.match"); try { auto regex = state.regexCache->get(re); PathSet context; - const auto str = state.forceString(*args[1], context, pos); + const auto str = state.forceString(*args[1], context, pos, "while evaluating the second argument passed to builtins.match"); std::cmatch match; if (!std::regex_match(str.begin(), str.end(), match, regex)) { @@ -3664,14 +3655,14 @@ static RegisterPrimOp primop_match({ non-matching parts interleaved by the lists of the matching groups. */ void prim_split(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - auto re = state.forceStringNoCtx(*args[0], pos); + auto re = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.split"); try { auto regex = state.regexCache->get(re); PathSet context; - const auto str = state.forceString(*args[1], context, pos); + const auto str = state.forceString(*args[1], context, pos, "while evaluating the second argument passed to builtins.split"); auto begin = std::cregex_iterator(str.begin(), str.end(), regex); auto end = std::cregex_iterator(); @@ -3769,8 +3760,8 @@ static void prim_concatStringsSep(EvalState & state, const PosIdx pos, Value * * { PathSet context; - auto sep = state.forceString(*args[0], context, pos); - state.forceList(*args[1], pos); + auto sep = state.forceString(*args[0], context, pos, "while evaluating the first argument (the separator string) passed to builtins.concatStringsSep"); + state.forceList(*args[1], pos, "while evaluating the second argument (the list of strings to concat) passed to builtins.concatStringsSep"); std::string res; res.reserve((args[1]->listSize() + 32) * sep.size()); @@ -3778,7 +3769,7 @@ static void prim_concatStringsSep(EvalState & state, const PosIdx pos, Value * * for (auto elem : args[1]->listItems()) { if (first) first = false; else res += sep; - res += *state.coerceToString(pos, *elem, context); + res += *state.coerceToString(pos, *elem, context, "while evaluating one element of the list of strings to concat passed to builtins.concatStringsSep"); } v.mkString(res, context); @@ -3797,8 +3788,8 @@ static RegisterPrimOp primop_concatStringsSep({ static void prim_replaceStrings(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceList(*args[0], pos); - state.forceList(*args[1], pos); + state.forceList(*args[0], pos, "while evaluating the first argument passed to builtins.replaceStrings"); + state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.replaceStrings"); if (args[0]->listSize() != args[1]->listSize()) state.debugThrowLastTrace(EvalError({ .msg = hintfmt("'from' and 'to' arguments to 'replaceStrings' have different lengths"), @@ -3808,18 +3799,18 @@ static void prim_replaceStrings(EvalState & state, const PosIdx pos, Value * * a std::vector<std::string> from; from.reserve(args[0]->listSize()); for (auto elem : args[0]->listItems()) - from.emplace_back(state.forceString(*elem, pos)); + from.emplace_back(state.forceString(*elem, pos, "while evaluating one of the strings to replace in builtins.replaceStrings")); std::vector<std::pair<std::string, PathSet>> to; to.reserve(args[1]->listSize()); for (auto elem : args[1]->listItems()) { PathSet ctx; - auto s = state.forceString(*elem, ctx, pos); + auto s = state.forceString(*elem, ctx, pos, "while evaluating one of the replacement strings of builtins.replaceStrings"); to.emplace_back(s, std::move(ctx)); } PathSet context; - auto s = state.forceString(*args[2], context, pos); + auto s = state.forceString(*args[2], context, pos, "while evaluating the third argument passed to builtins.replaceStrings"); std::string res; // Loops one past last character to handle the case where 'from' contains an empty string. @@ -3877,7 +3868,7 @@ static RegisterPrimOp primop_replaceStrings({ static void prim_parseDrvName(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - auto name = state.forceStringNoCtx(*args[0], pos); + auto name = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.parseDrvName"); DrvName parsed(name); auto attrs = state.buildBindings(2); attrs.alloc(state.sName).mkString(parsed.name); @@ -3901,8 +3892,8 @@ static RegisterPrimOp primop_parseDrvName({ static void prim_compareVersions(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - auto version1 = state.forceStringNoCtx(*args[0], pos); - auto version2 = state.forceStringNoCtx(*args[1], pos); + auto version1 = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.compareVersions"); + auto version2 = state.forceStringNoCtx(*args[1], pos, "while evaluating the second argument passed to builtins.compareVersions"); v.mkInt(compareVersions(version1, version2)); } @@ -3921,7 +3912,7 @@ static RegisterPrimOp primop_compareVersions({ static void prim_splitVersion(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - auto version = state.forceStringNoCtx(*args[0], pos); + auto version = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.splitVersion"); auto iter = version.cbegin(); Strings components; while (iter != version.cend()) { diff --git a/src/libexpr/primops/context.cc b/src/libexpr/primops/context.cc index 4b7357495..0c65a6b98 100644 --- a/src/libexpr/primops/context.cc +++ b/src/libexpr/primops/context.cc @@ -8,7 +8,7 @@ namespace nix { static void prim_unsafeDiscardStringContext(EvalState & state, const PosIdx pos, Value * * args, Value & v) { PathSet context; - auto s = state.coerceToString(pos, *args[0], context); + auto s = state.coerceToString(pos, *args[0], context, "while evaluating the argument passed to builtins.unsafeDiscardStringContext"); v.mkString(*s); } @@ -18,7 +18,7 @@ static RegisterPrimOp primop_unsafeDiscardStringContext("__unsafeDiscardStringCo static void prim_hasContext(EvalState & state, const PosIdx pos, Value * * args, Value & v) { PathSet context; - state.forceString(*args[0], context, pos); + state.forceString(*args[0], context, pos, "while evaluating the argument passed to builtins.hasContext"); v.mkBool(!context.empty()); } @@ -34,7 +34,7 @@ static RegisterPrimOp primop_hasContext("__hasContext", 1, prim_hasContext); static void prim_unsafeDiscardOutputDependency(EvalState & state, const PosIdx pos, Value * * args, Value & v) { PathSet context; - auto s = state.coerceToString(pos, *args[0], context); + auto s = state.coerceToString(pos, *args[0], context, "while evaluating the argument passed to builtins.unsafeDiscardOutputDependency"); PathSet context2; for (auto && p : context) { @@ -80,7 +80,7 @@ static void prim_getContext(EvalState & state, const PosIdx pos, Value * * args, Strings outputs; }; PathSet context; - state.forceString(*args[0], context, pos); + state.forceString(*args[0], context, pos, "while evaluating the argument passed to builtins.getContext"); auto contextInfos = std::map<StorePath, ContextInfo>(); for (const auto & p : context) { Path drv; @@ -132,9 +132,9 @@ static RegisterPrimOp primop_getContext("__getContext", 1, prim_getContext); static void prim_appendContext(EvalState & state, const PosIdx pos, Value * * args, Value & v) { PathSet context; - auto orig = state.forceString(*args[0], context, pos); + auto orig = state.forceString(*args[0], context, noPos, "while evaluating the first argument passed to builtins.appendContext"); - state.forceAttrs(*args[1], pos); + state.forceAttrs(*args[1], pos, "while evaluating the second argument passed to builtins.appendContext"); auto sPath = state.symbols.create("path"); auto sAllOutputs = state.symbols.create("allOutputs"); @@ -142,24 +142,24 @@ static void prim_appendContext(EvalState & state, const PosIdx pos, Value * * ar const auto & name = state.symbols[i.name]; if (!state.store->isStorePath(name)) throw EvalError({ - .msg = hintfmt("Context key '%s' is not a store path", name), + .msg = hintfmt("context key '%s' is not a store path", name), .errPos = state.positions[i.pos] }); if (!settings.readOnlyMode) state.store->ensurePath(state.store->parseStorePath(name)); - state.forceAttrs(*i.value, i.pos); + state.forceAttrs(*i.value, i.pos, "while evaluating the value of a string context"); auto iter = i.value->attrs->find(sPath); if (iter != i.value->attrs->end()) { - if (state.forceBool(*iter->value, iter->pos)) + if (state.forceBool(*iter->value, iter->pos, "while evaluating the `path` attribute of a string context")) context.emplace(name); } iter = i.value->attrs->find(sAllOutputs); if (iter != i.value->attrs->end()) { - if (state.forceBool(*iter->value, iter->pos)) { + if (state.forceBool(*iter->value, iter->pos, "while evaluating the `allOutputs` attribute of a string context")) { if (!isDerivation(name)) { throw EvalError({ - .msg = hintfmt("Tried to add all-outputs context of %s, which is not a derivation, to a string", name), + .msg = hintfmt("tried to add all-outputs context of %s, which is not a derivation, to a string", name), .errPos = state.positions[i.pos] }); } @@ -169,15 +169,15 @@ static void prim_appendContext(EvalState & state, const PosIdx pos, Value * * ar iter = i.value->attrs->find(state.sOutputs); if (iter != i.value->attrs->end()) { - state.forceList(*iter->value, iter->pos); + state.forceList(*iter->value, iter->pos, "while evaluating the `outputs` attribute of a string context"); if (iter->value->listSize() && !isDerivation(name)) { throw EvalError({ - .msg = hintfmt("Tried to add derivation output context of %s, which is not a derivation, to a string", name), + .msg = hintfmt("tried to add derivation output context of %s, which is not a derivation, to a string", name), .errPos = state.positions[i.pos] }); } for (auto elem : iter->value->listItems()) { - auto outputName = state.forceStringNoCtx(*elem, iter->pos); + auto outputName = state.forceStringNoCtx(*elem, iter->pos, "while evaluating an output name within a string context"); context.insert(concatStrings("!", outputName, "!", name)); } } diff --git a/src/libexpr/primops/fetchClosure.cc b/src/libexpr/primops/fetchClosure.cc index 662c9652e..0dfa97fa3 100644 --- a/src/libexpr/primops/fetchClosure.cc +++ b/src/libexpr/primops/fetchClosure.cc @@ -7,7 +7,7 @@ namespace nix { static void prim_fetchClosure(EvalState & state, const PosIdx pos, Value * * args, Value & v) { - state.forceAttrs(*args[0], pos); + state.forceAttrs(*args[0], pos, "while evaluating the argument passed to builtins.fetchClosure"); std::optional<std::string> fromStoreUrl; std::optional<StorePath> fromPath; @@ -19,7 +19,8 @@ static void prim_fetchClosure(EvalState & state, const PosIdx pos, Value * * arg if (attrName == "fromPath") { PathSet context; - fromPath = state.coerceToStorePath(attr.pos, *attr.value, context); + fromPath = state.coerceToStorePath(attr.pos, *attr.value, context, + "while evaluating the 'fromPath' attribute passed to builtins.fetchClosure"); } else if (attrName == "toPath") { @@ -27,12 +28,14 @@ static void prim_fetchClosure(EvalState & state, const PosIdx pos, Value * * arg toCA = true; if (attr.value->type() != nString || attr.value->string.s != std::string("")) { PathSet context; - toPath = state.coerceToStorePath(attr.pos, *attr.value, context); + toPath = state.coerceToStorePath(attr.pos, *attr.value, context, + "while evaluating the 'toPath' attribute passed to builtins.fetchClosure"); } } else if (attrName == "fromStore") - fromStoreUrl = state.forceStringNoCtx(*attr.value, attr.pos); + fromStoreUrl = state.forceStringNoCtx(*attr.value, attr.pos, + "while evaluating the 'fromStore' attribute passed to builtins.fetchClosure"); else throw Error({ diff --git a/src/libexpr/primops/fetchMercurial.cc b/src/libexpr/primops/fetchMercurial.cc index 249c0934e..c9c93bdba 100644 --- a/src/libexpr/primops/fetchMercurial.cc +++ b/src/libexpr/primops/fetchMercurial.cc @@ -19,23 +19,21 @@ static void prim_fetchMercurial(EvalState & state, const PosIdx pos, Value * * a if (args[0]->type() == nAttrs) { - state.forceAttrs(*args[0], pos); - for (auto & attr : *args[0]->attrs) { std::string_view n(state.symbols[attr.name]); if (n == "url") - url = state.coerceToString(attr.pos, *attr.value, context, false, false).toOwned(); + url = state.coerceToString(attr.pos, *attr.value, context, false, false, "while evaluating the `url` attribute passed to builtins.fetchMercurial").toOwned(); else if (n == "rev") { // Ugly: unlike fetchGit, here the "rev" attribute can // be both a revision or a branch/tag name. - auto value = state.forceStringNoCtx(*attr.value, attr.pos); + auto value = state.forceStringNoCtx(*attr.value, attr.pos, "while evaluating the `rev` attribute passed to builtins.fetchMercurial"); if (std::regex_match(value.begin(), value.end(), revRegex)) rev = Hash::parseAny(value, htSHA1); else ref = value; } else if (n == "name") - name = state.forceStringNoCtx(*attr.value, attr.pos); + name = state.forceStringNoCtx(*attr.value, attr.pos, "while evaluating the `name` attribute passed to builtins.fetchMercurial"); else throw EvalError({ .msg = hintfmt("unsupported argument '%s' to 'fetchMercurial'", state.symbols[attr.name]), @@ -50,7 +48,7 @@ static void prim_fetchMercurial(EvalState & state, const PosIdx pos, Value * * a }); } else - url = state.coerceToString(pos, *args[0], context, false, false).toOwned(); + url = state.coerceToString(pos, *args[0], context, false, false, "while evaluating the first argument passed to builtins.fetchMercurial").toOwned(); // FIXME: git externals probably can be used to bypass the URI // whitelist. Ah well. diff --git a/src/libexpr/primops/fetchTree.cc b/src/libexpr/primops/fetchTree.cc index fb392a6e8..cc318cbaa 100644 --- a/src/libexpr/primops/fetchTree.cc +++ b/src/libexpr/primops/fetchTree.cc @@ -102,7 +102,7 @@ static void fetchTree( state.forceValue(*args[0], pos); if (args[0]->type() == nAttrs) { - state.forceAttrs(*args[0], pos); + state.forceAttrs(*args[0], pos, "while evaluating the argument passed to builtins.fetchTree"); fetchers::Attrs attrs; @@ -112,7 +112,7 @@ static void fetchTree( .msg = hintfmt("unexpected attribute 'type'"), .errPos = state.positions[pos] })); - type = state.forceStringNoCtx(*aType->value, aType->pos); + type = state.forceStringNoCtx(*aType->value, aType->pos, "while evaluating the `type` attribute passed to builtins.fetchTree"); } else if (!type) state.debugThrowLastTrace(EvalError({ .msg = hintfmt("attribute 'type' is missing in call to 'fetchTree'"), @@ -125,7 +125,7 @@ static void fetchTree( if (attr.name == state.sType) continue; state.forceValue(*attr.value, attr.pos); if (attr.value->type() == nPath || attr.value->type() == nString) { - auto s = state.coerceToString(attr.pos, *attr.value, context, false, false).toOwned(); + auto s = state.coerceToString(attr.pos, *attr.value, context, false, false, "").toOwned(); attrs.emplace(state.symbols[attr.name], state.symbols[attr.name] == "url" ? type == "git" @@ -151,7 +151,7 @@ static void fetchTree( input = fetchers::Input::fromAttrs(std::move(attrs)); } else { - auto url = state.coerceToString(pos, *args[0], context, false, false).toOwned(); + auto url = state.coerceToString(pos, *args[0], context, false, false, "while evaluating the first argument passed to the fetcher").toOwned(); if (type == "git") { fetchers::Attrs attrs; @@ -195,16 +195,14 @@ static void fetch(EvalState & state, const PosIdx pos, Value * * args, Value & v if (args[0]->type() == nAttrs) { - state.forceAttrs(*args[0], pos); - for (auto & attr : *args[0]->attrs) { std::string_view n(state.symbols[attr.name]); if (n == "url") - url = state.forceStringNoCtx(*attr.value, attr.pos); + url = state.forceStringNoCtx(*attr.value, attr.pos, "while evaluating the url we should fetch"); else if (n == "sha256") - expectedHash = newHashAllowEmpty(state.forceStringNoCtx(*attr.value, attr.pos), htSHA256); + expectedHash = newHashAllowEmpty(state.forceStringNoCtx(*attr.value, attr.pos, "while evaluating the sha256 of the content we should fetch"), htSHA256); else if (n == "name") - name = state.forceStringNoCtx(*attr.value, attr.pos); + name = state.forceStringNoCtx(*attr.value, attr.pos, "while evaluating the name of the content we should fetch"); else state.debugThrowLastTrace(EvalError({ .msg = hintfmt("unsupported argument '%s' to '%s'", n, who), @@ -218,7 +216,7 @@ static void fetch(EvalState & state, const PosIdx pos, Value * * args, Value & v .errPos = state.positions[pos] })); } else - url = state.forceStringNoCtx(*args[0], pos); + url = state.forceStringNoCtx(*args[0], pos, "while evaluating the url we should fetch"); if (who == "fetchTarball") url = evalSettings.resolvePseudoUrl(*url); diff --git a/src/libexpr/primops/fromTOML.cc b/src/libexpr/primops/fromTOML.cc index 9753e2ac9..8a5231781 100644 --- a/src/libexpr/primops/fromTOML.cc +++ b/src/libexpr/primops/fromTOML.cc @@ -7,7 +7,7 @@ namespace nix { static void prim_fromTOML(EvalState & state, const PosIdx pos, Value * * args, Value & val) { - auto toml = state.forceStringNoCtx(*args[0], pos); + auto toml = state.forceStringNoCtx(*args[0], pos, "while evaluating the argument passed to builtins.fromTOML"); std::istringstream tomlStream(std::string{toml}); diff --git a/src/libexpr/tests/error_traces.cc b/src/libexpr/tests/error_traces.cc new file mode 100644 index 000000000..8741ecdd2 --- /dev/null +++ b/src/libexpr/tests/error_traces.cc @@ -0,0 +1,94 @@ +#include <gmock/gmock.h> +#include <gtest/gtest.h> + +#include "libexprtests.hh" + +namespace nix { + + using namespace testing; + + // Testing eval of PrimOp's + class ErrorTraceTest : public LibExprTest { }; + +#define ASSERT_TRACE1(args, type, message) \ + ASSERT_THROW( \ + try { \ + eval("builtins." args); \ + } catch (BaseError & e) { \ + ASSERT_EQ(PrintToString(e.info().msg), \ + PrintToString(message)); \ + auto trace = e.info().traces.rbegin(); \ + ASSERT_EQ(PrintToString(trace->hint), \ + PrintToString(hintfmt("while calling the '%s' builtin", "genericClosure"))); \ + throw; \ + } \ + , type \ + ) + +#define ASSERT_TRACE2(args, type, message, context) \ + ASSERT_THROW( \ + try { \ + eval("builtins." args); \ + } catch (BaseError & e) { \ + ASSERT_EQ(PrintToString(e.info().msg), \ + PrintToString(message)); \ + auto trace = e.info().traces.rbegin(); \ + ASSERT_EQ(PrintToString(trace->hint), \ + PrintToString(context)); \ + ++trace; \ + ASSERT_EQ(PrintToString(trace->hint), \ + PrintToString(hintfmt("while calling the '%s' builtin", "genericClosure"))); \ + throw; \ + } \ + , type \ + ) + + TEST_F(ErrorTraceTest, genericClosure) { \ + ASSERT_TRACE2("genericClosure 1", + TypeError, + hintfmt("value is %s while a set was expected", "an integer"), + hintfmt("while evaluating the first argument passed to builtins.genericClosure")); + + ASSERT_TRACE1("genericClosure {}", + TypeError, + hintfmt("attribute '%s' missing %s", "startSet", normaltxt("in the attrset passed as argument to builtins.genericClosure"))); + + ASSERT_TRACE2("genericClosure { startSet = 1; }", + TypeError, + hintfmt("value is %s while a list was expected", "an integer"), + hintfmt("while evaluating the 'startSet' attribute passed as argument to builtins.genericClosure")); + + // Okay: "genericClosure { startSet = []; }" + + ASSERT_TRACE2("genericClosure { startSet = [{ key = 1;}]; operator = true; }", + TypeError, + hintfmt("value is %s while a function was expected", "a Boolean"), + hintfmt("while evaluating the 'operator' attribute passed as argument to builtins.genericClosure")); + + ASSERT_TRACE2("genericClosure { startSet = [{ key = 1;}]; operator = item: true; }", + TypeError, + hintfmt("value is %s while a list was expected", "a Boolean"), + hintfmt("while evaluating the return value of the `operator` passed to builtins.genericClosure")); // TODO: inconsistent naming + + ASSERT_TRACE2("genericClosure { startSet = [{ key = 1;}]; operator = item: [ true ]; }", + TypeError, + hintfmt("value is %s while a set was expected", "a Boolean"), + hintfmt("while evaluating one of the elements generated by (or initially passed to) builtins.genericClosure")); + + ASSERT_TRACE1("genericClosure { startSet = [{ key = 1;}]; operator = item: [ {} ]; }", + TypeError, + hintfmt("attribute '%s' missing %s", "key", normaltxt("in one of the attrsets generated by (or initially passed to) builtins.genericClosure"))); + + ASSERT_TRACE2("genericClosure { startSet = [{ key = 1;}]; operator = item: [{ key = ''a''; }]; }", + EvalError, + hintfmt("cannot compare %s with %s", "a string", "an integer"), + hintfmt("while comparing the `key` attributes of two genericClosure elements")); + + ASSERT_TRACE2("genericClosure { startSet = [ true ]; operator = item: [{ key = ''a''; }]; }", + TypeError, + hintfmt("value is %s while a set was expected", "a Boolean"), + hintfmt("while evaluating one of the elements generated by (or initially passed to) builtins.genericClosure")); + + } + +} /* namespace nix */ diff --git a/src/libexpr/tests/primops.cc b/src/libexpr/tests/primops.cc index bcdc7086b..9cdcf64a1 100644 --- a/src/libexpr/tests/primops.cc +++ b/src/libexpr/tests/primops.cc @@ -823,4 +823,10 @@ namespace nix { for (const auto [n, elem] : enumerate(v.listItems())) ASSERT_THAT(*elem, IsStringEq(expected[n])); } + + TEST_F(PrimOpTest, genericClosure_not_strict) { + // Operator should not be used when startSet is empty + auto v = eval("builtins.genericClosure { startSet = []; }"); + ASSERT_THAT(v, IsListOfSize(0)); + } } /* namespace nix */ diff --git a/src/libexpr/value.hh b/src/libexpr/value.hh index 508dbe218..7d3f6d700 100644 --- a/src/libexpr/value.hh +++ b/src/libexpr/value.hh @@ -89,7 +89,7 @@ class ExternalValueBase /* Coerce the value to a string. Defaults to uncoercable, i.e. throws an * error. */ - virtual std::string coerceToString(const Pos & pos, PathSet & context, bool copyMore, bool copyToStore) const; + virtual std::string coerceToString(const Pos & pos, PathSet & context, bool copyMore, bool copyToStore, std::string_view errorCtx) const; /* Compare to another value of the same type. Defaults to uncomparable, * i.e. always false. diff --git a/src/libmain/shared.cc b/src/libmain/shared.cc index 6d4365652..d4871a8e2 100644 --- a/src/libmain/shared.cc +++ b/src/libmain/shared.cc @@ -404,8 +404,6 @@ int handleExceptions(const std::string & programName, std::function<void()> fun) return 1; } catch (BaseError & e) { logError(e.info()); - if (e.hasTrace() && !loggerSettings.showTrace.get()) - printError("(use '--show-trace' to show detailed location information)"); return e.status; } catch (std::bad_alloc & e) { printError(error + "out of memory"); diff --git a/src/libutil/error.cc b/src/libutil/error.cc index 1a1aecea5..e4f0d4677 100644 --- a/src/libutil/error.cc +++ b/src/libutil/error.cc @@ -9,9 +9,9 @@ namespace nix { const std::string nativeSystem = SYSTEM; -void BaseError::addTrace(std::shared_ptr<AbstractPos> && e, hintformat hint) +void BaseError::addTrace(std::shared_ptr<AbstractPos> && e, hintformat hint, bool frame) { - err.traces.push_front(Trace { .pos = std::move(e), .hint = hint }); + err.traces.push_front(Trace { .pos = std::move(e), .hint = hint, .frame = frame }); } // c++ std::exception descendants must have a 'const char* what()' function. @@ -200,13 +200,125 @@ std::ostream & showErrorInfo(std::ostream & out, const ErrorInfo & einfo, bool s auto noSource = ANSI_ITALIC " (source not available)" ANSI_NORMAL "\n"; - // traces - if (showTrace && !einfo.traces.empty()) { + /* + * Traces + * ------ + * + * The semantics of traces is a bit weird. We have only one option to + * print them and to make them verbose (--show-trace). In the code they + * are always collected, but they are not printed by default. The code + * also collects more traces when the option is on. This means that there + * is no way to print the simplified traces at all. + * + * I (layus) designed the code to attach positions to a restricted set of + * messages. This means that we have a lot of traces with no position at + * all, including most of the base error messages. For example "type + * error: found a string while a set was expected" has no position, but + * will come with several traces detailing it's precise relation to the + * closest know position. This makes erroring without printing traces + * quite useless. + * + * This is why I introduced the idea to always print a few traces on + * error. The number 3 is quite arbitrary, and was selected so as not to + * clutter the console on error. For the same reason, a trace with an + * error position takes more space, and counts as two traces towards the + * limit. + * + * The rest is truncated, unless --show-trace is passed. This preserves + * the same bad semantics of --show-trace to both show the trace and + * augment it with new data. Not too sure what is the best course of + * action. + * + * The issue is that it is fundamentally hard to provide a trace for a + * lazy language. The trace will only cover the current spine of the + * evaluation, missing things that have been evaluated before. For + * example, most type errors are hard to inspect because there is not + * trace for the faulty value. These errors should really print the faulty + * value itself. + * + * In function calls, the --show-trace flag triggers extra traces for each + * function invocation. These work as scopes, allowing to follow the + * current spine of the evaluation graph. Without that flag, the error + * trace should restrict itself to a restricted prefix of that trace, + * until the first scope. If we ever get to such a precise error + * reporting, there would be no need to add an arbitrary limit here. We + * could always print the full trace, and it would just be small without + * the flag. + * + * One idea I had is for XxxError.addTrace() to perform nothing if one + * scope has already been traced. Alternatively, we could stop here when + * we encounter such a scope instead of after an arbitrary number of + * traces. This however requires to augment traces with the notion of + * "scope". + * + * This is particularly visible in code like evalAttrs(...) where we have + * to make a decision between the two following options. + * + * ``` long traces + * inline void EvalState::evalAttrs(Env & env, Expr * e, Value & v, const Pos & pos, std::string_view errorCtx) + * { + * try { + * e->eval(*this, env, v); + * if (v.type() != nAttrs) + * throwTypeError("value is %1% while a set was expected", v); + * } catch (Error & e) { + * e.addTrace(pos, errorCtx); + * throw; + * } + * } + * ``` + * + * ``` short traces + * inline void EvalState::evalAttrs(Env & env, Expr * e, Value & v, const Pos & pos, std::string_view errorCtx) + * { + * e->eval(*this, env, v); + * try { + * if (v.type() != nAttrs) + * throwTypeError("value is %1% while a set was expected", v); + * } catch (Error & e) { + * e.addTrace(pos, errorCtx); + * throw; + * } + * } + * ``` + * + * The second example can be rewritten more concisely, but kept in this + * form to highlight the symmetry. The first option adds more information, + * because whatever caused an error down the line, in the generic eval + * function, will get annotated with the code location that uses and + * required it. The second option is less verbose, but does not provide + * any context at all as to where and why a failing value was required. + * + * Scopes would fix that, by adding context only when --show-trace is + * passed, and keeping the trace terse otherwise. + * + */ + + // Enough indent to align with with the `... ` + // prepended to each element of the trace + auto ellipsisIndent = " "; + + bool frameOnly = false; + if (!einfo.traces.empty()) { + size_t count = 0; for (const auto & trace : einfo.traces) { + if (!showTrace && count > 3) { + oss << "\n" << ANSI_WARNING "(stack trace truncated; use '--show-trace' to show the full trace)" ANSI_NORMAL << "\n"; + break; + } + + if (trace.hint.str().empty()) continue; + if (frameOnly && !trace.frame) continue; + + count++; + frameOnly = trace.frame; + oss << "\n" << "… " << trace.hint.str() << "\n"; if (trace.pos) { - oss << "\n" << ANSI_BLUE << "at " ANSI_WARNING << *trace.pos << ANSI_NORMAL << ":"; + count++; + + oss << "\n" << ellipsisIndent << ANSI_BLUE << "at " ANSI_WARNING << *trace.pos << ANSI_NORMAL << ":"; if (auto loc = trace.pos->getCodeLines()) { oss << "\n"; diff --git a/src/libutil/error.hh b/src/libutil/error.hh index c3bb8c0df..7d236028c 100644 --- a/src/libutil/error.hh +++ b/src/libutil/error.hh @@ -86,6 +86,7 @@ void printCodeLines(std::ostream & out, struct Trace { std::shared_ptr<AbstractPos> pos; hintformat hint; + bool frame; }; struct ErrorInfo { @@ -114,6 +115,8 @@ protected: public: unsigned int status = 1; // exit status + BaseError(const BaseError &) = default; + template<typename... Args> BaseError(unsigned int status, const Args & ... args) : err { .level = lvlError, .msg = hintfmt(args...) } @@ -152,15 +155,22 @@ public: const std::string & msg() const { return calcWhat(); } const ErrorInfo & info() const { calcWhat(); return err; } + void pushTrace(Trace trace) + { + err.traces.push_front(trace); + } + template<typename... Args> - void addTrace(std::shared_ptr<AbstractPos> && e, const std::string & fs, const Args & ... args) + void addTrace(std::shared_ptr<AbstractPos> && e, std::string_view fs, const Args & ... args) { - addTrace(std::move(e), hintfmt(fs, args...)); + addTrace(std::move(e), hintfmt(std::string(fs), args...)); } - void addTrace(std::shared_ptr<AbstractPos> && e, hintformat hint); + void addTrace(std::shared_ptr<AbstractPos> && e, hintformat hint, bool frame = false); bool hasTrace() const { return !err.traces.empty(); } + + const ErrorInfo & info() { return err; }; }; #define MakeError(newClass, superClass) \ diff --git a/src/nix-env/user-env.cc b/src/nix-env/user-env.cc index 4b1202be3..cad7f9c88 100644 --- a/src/nix-env/user-env.cc +++ b/src/nix-env/user-env.cc @@ -134,9 +134,9 @@ bool createUserEnv(EvalState & state, DrvInfos & elems, state.forceValue(topLevel, [&]() { return topLevel.determinePos(noPos); }); PathSet context; Attr & aDrvPath(*topLevel.attrs->find(state.sDrvPath)); - auto topLevelDrv = state.coerceToStorePath(aDrvPath.pos, *aDrvPath.value, context); + auto topLevelDrv = state.coerceToStorePath(aDrvPath.pos, *aDrvPath.value, context, ""); Attr & aOutPath(*topLevel.attrs->find(state.sOutPath)); - auto topLevelOut = state.coerceToStorePath(aOutPath.pos, *aOutPath.value, context); + auto topLevelOut = state.coerceToStorePath(aOutPath.pos, *aOutPath.value, context, ""); /* Realise the resulting store expression. */ debug("building user environment"); diff --git a/src/nix/bundle.cc b/src/nix/bundle.cc index 26db08d80..6ae9460f6 100644 --- a/src/nix/bundle.cc +++ b/src/nix/bundle.cc @@ -97,13 +97,13 @@ struct CmdBundle : InstallableCommand throw Error("the bundler '%s' does not produce a derivation", bundler.what()); PathSet context2; - auto drvPath = evalState->coerceToStorePath(attr1->pos, *attr1->value, context2); + auto drvPath = evalState->coerceToStorePath(attr1->pos, *attr1->value, context2, ""); auto attr2 = vRes->attrs->get(evalState->sOutPath); if (!attr2) throw Error("the bundler '%s' does not produce a derivation", bundler.what()); - auto outPath = evalState->coerceToStorePath(attr2->pos, *attr2->value, context2); + auto outPath = evalState->coerceToStorePath(attr2->pos, *attr2->value, context2, ""); store->buildPaths({ DerivedPath::Built { @@ -118,7 +118,7 @@ struct CmdBundle : InstallableCommand auto * attr = vRes->attrs->get(evalState->sName); if (!attr) throw Error("attribute 'name' missing"); - outLink = evalState->forceStringNoCtx(*attr->value, attr->pos); + outLink = evalState->forceStringNoCtx(*attr->value, attr->pos, ""); } // TODO: will crash if not a localFSStore? diff --git a/src/nix/eval.cc b/src/nix/eval.cc index ba82b5772..ccee074e9 100644 --- a/src/nix/eval.cc +++ b/src/nix/eval.cc @@ -112,7 +112,7 @@ struct CmdEval : MixJSON, InstallableCommand else if (raw) { stopProgressBar(); - std::cout << *state->coerceToString(noPos, *v, context); + std::cout << *state->coerceToString(noPos, *v, context, "while generating the eval command output"); } else if (json) { diff --git a/src/nix/flake.cc b/src/nix/flake.cc index 17ebf12eb..020c1b182 100644 --- a/src/nix/flake.cc +++ b/src/nix/flake.cc @@ -126,12 +126,12 @@ static void enumerateOutputs(EvalState & state, Value & vFlake, std::function<void(const std::string & name, Value & vProvide, const PosIdx pos)> callback) { auto pos = vFlake.determinePos(noPos); - state.forceAttrs(vFlake, pos); + state.forceAttrs(vFlake, pos, "while evaluating a flake to get its outputs"); auto aOutputs = vFlake.attrs->get(state.symbols.create("outputs")); assert(aOutputs); - state.forceAttrs(*aOutputs->value, pos); + state.forceAttrs(*aOutputs->value, pos, "while evaluating the outputs of a flake"); auto sHydraJobs = state.symbols.create("hydraJobs"); @@ -391,13 +391,13 @@ struct CmdFlakeCheck : FlakeCommand checkHydraJobs = [&](const std::string & attrPath, Value & v, const PosIdx pos) { try { - state->forceAttrs(v, pos); + state->forceAttrs(v, pos, ""); if (state->isDerivation(v)) throw Error("jobset should not be a derivation at top-level"); for (auto & attr : *v.attrs) { - state->forceAttrs(*attr.value, attr.pos); + state->forceAttrs(*attr.value, attr.pos, ""); auto attrPath2 = concatStrings(attrPath, ".", state->symbols[attr.name]); if (state->isDerivation(*attr.value)) { Activity act(*logger, lvlChatty, actUnknown, @@ -419,7 +419,7 @@ struct CmdFlakeCheck : FlakeCommand fmt("checking NixOS configuration '%s'", attrPath)); Bindings & bindings(*state->allocBindings(0)); auto vToplevel = findAlongAttrPath(*state, "config.system.build.toplevel", bindings, v).first; - state->forceAttrs(*vToplevel, pos); + state->forceValue(*vToplevel, pos); if (!state->isDerivation(*vToplevel)) throw Error("attribute 'config.system.build.toplevel' is not a derivation"); } catch (Error & e) { @@ -433,12 +433,12 @@ struct CmdFlakeCheck : FlakeCommand Activity act(*logger, lvlChatty, actUnknown, fmt("checking template '%s'", attrPath)); - state->forceAttrs(v, pos); + state->forceAttrs(v, pos, ""); if (auto attr = v.attrs->get(state->symbols.create("path"))) { if (attr->name == state->symbols.create("path")) { PathSet context; - auto path = state->coerceToPath(attr->pos, *attr->value, context); + auto path = state->coerceToPath(attr->pos, *attr->value, context, ""); if (!store->isInStore(path)) throw Error("template '%s' has a bad 'path' attribute"); // TODO: recursively check the flake in 'path'. @@ -447,7 +447,7 @@ struct CmdFlakeCheck : FlakeCommand throw Error("template '%s' lacks attribute 'path'", attrPath); if (auto attr = v.attrs->get(state->symbols.create("description"))) - state->forceStringNoCtx(*attr->value, attr->pos); + state->forceStringNoCtx(*attr->value, attr->pos, ""); else throw Error("template '%s' lacks attribute 'description'", attrPath); @@ -504,11 +504,11 @@ struct CmdFlakeCheck : FlakeCommand warn("flake output attribute '%s' is deprecated; use '%s' instead", name, replacement); if (name == "checks") { - state->forceAttrs(vOutput, pos); + state->forceAttrs(vOutput, pos, ""); for (auto & attr : *vOutput.attrs) { const auto & attr_name = state->symbols[attr.name]; checkSystemName(attr_name, attr.pos); - state->forceAttrs(*attr.value, attr.pos); + state->forceAttrs(*attr.value, attr.pos, ""); for (auto & attr2 : *attr.value->attrs) { auto drvPath = checkDerivation( fmt("%s.%s.%s", name, attr_name, state->symbols[attr2.name]), @@ -524,7 +524,7 @@ struct CmdFlakeCheck : FlakeCommand } else if (name == "formatter") { - state->forceAttrs(vOutput, pos); + state->forceAttrs(vOutput, pos, ""); for (auto & attr : *vOutput.attrs) { const auto & attr_name = state->symbols[attr.name]; checkSystemName(attr_name, attr.pos); @@ -535,11 +535,11 @@ struct CmdFlakeCheck : FlakeCommand } else if (name == "packages" || name == "devShells") { - state->forceAttrs(vOutput, pos); + state->forceAttrs(vOutput, pos, ""); for (auto & attr : *vOutput.attrs) { const auto & attr_name = state->symbols[attr.name]; checkSystemName(attr_name, attr.pos); - state->forceAttrs(*attr.value, attr.pos); + state->forceAttrs(*attr.value, attr.pos, ""); for (auto & attr2 : *attr.value->attrs) checkDerivation( fmt("%s.%s.%s", name, attr_name, state->symbols[attr2.name]), @@ -548,11 +548,11 @@ struct CmdFlakeCheck : FlakeCommand } else if (name == "apps") { - state->forceAttrs(vOutput, pos); + state->forceAttrs(vOutput, pos, ""); for (auto & attr : *vOutput.attrs) { const auto & attr_name = state->symbols[attr.name]; checkSystemName(attr_name, attr.pos); - state->forceAttrs(*attr.value, attr.pos); + state->forceAttrs(*attr.value, attr.pos, ""); for (auto & attr2 : *attr.value->attrs) checkApp( fmt("%s.%s.%s", name, attr_name, state->symbols[attr2.name]), @@ -561,7 +561,7 @@ struct CmdFlakeCheck : FlakeCommand } else if (name == "defaultPackage" || name == "devShell") { - state->forceAttrs(vOutput, pos); + state->forceAttrs(vOutput, pos, ""); for (auto & attr : *vOutput.attrs) { const auto & attr_name = state->symbols[attr.name]; checkSystemName(attr_name, attr.pos); @@ -572,7 +572,7 @@ struct CmdFlakeCheck : FlakeCommand } else if (name == "defaultApp") { - state->forceAttrs(vOutput, pos); + state->forceAttrs(vOutput, pos, ""); for (auto & attr : *vOutput.attrs) { const auto & attr_name = state->symbols[attr.name]; checkSystemName(attr_name, attr.pos); @@ -583,7 +583,7 @@ struct CmdFlakeCheck : FlakeCommand } else if (name == "legacyPackages") { - state->forceAttrs(vOutput, pos); + state->forceAttrs(vOutput, pos, ""); for (auto & attr : *vOutput.attrs) { checkSystemName(state->symbols[attr.name], attr.pos); // FIXME: do getDerivations? @@ -594,7 +594,7 @@ struct CmdFlakeCheck : FlakeCommand checkOverlay(name, vOutput, pos); else if (name == "overlays") { - state->forceAttrs(vOutput, pos); + state->forceAttrs(vOutput, pos, ""); for (auto & attr : *vOutput.attrs) checkOverlay(fmt("%s.%s", name, state->symbols[attr.name]), *attr.value, attr.pos); @@ -604,14 +604,14 @@ struct CmdFlakeCheck : FlakeCommand checkModule(name, vOutput, pos); else if (name == "nixosModules") { - state->forceAttrs(vOutput, pos); + state->forceAttrs(vOutput, pos, ""); for (auto & attr : *vOutput.attrs) checkModule(fmt("%s.%s", name, state->symbols[attr.name]), *attr.value, attr.pos); } else if (name == "nixosConfigurations") { - state->forceAttrs(vOutput, pos); + state->forceAttrs(vOutput, pos, ""); for (auto & attr : *vOutput.attrs) checkNixOSConfiguration(fmt("%s.%s", name, state->symbols[attr.name]), *attr.value, attr.pos); @@ -624,14 +624,14 @@ struct CmdFlakeCheck : FlakeCommand checkTemplate(name, vOutput, pos); else if (name == "templates") { - state->forceAttrs(vOutput, pos); + state->forceAttrs(vOutput, pos, ""); for (auto & attr : *vOutput.attrs) checkTemplate(fmt("%s.%s", name, state->symbols[attr.name]), *attr.value, attr.pos); } else if (name == "defaultBundler") { - state->forceAttrs(vOutput, pos); + state->forceAttrs(vOutput, pos, ""); for (auto & attr : *vOutput.attrs) { const auto & attr_name = state->symbols[attr.name]; checkSystemName(attr_name, attr.pos); @@ -642,11 +642,11 @@ struct CmdFlakeCheck : FlakeCommand } else if (name == "bundlers") { - state->forceAttrs(vOutput, pos); + state->forceAttrs(vOutput, pos, ""); for (auto & attr : *vOutput.attrs) { const auto & attr_name = state->symbols[attr.name]; checkSystemName(attr_name, attr.pos); - state->forceAttrs(*attr.value, attr.pos); + state->forceAttrs(*attr.value, attr.pos, ""); for (auto & attr2 : *attr.value->attrs) { checkBundler( fmt("%s.%s.%s", name, attr_name, state->symbols[attr2.name]), diff --git a/src/nix/main.cc b/src/nix/main.cc index 2c6309c81..d3d2f5b16 100644 --- a/src/nix/main.cc +++ b/src/nix/main.cc @@ -199,7 +199,7 @@ static void showHelp(std::vector<std::string> subcommand, MultiCommand & topleve if (!attr) throw UsageError("Nix has no subcommand '%s'", concatStringsSep("", subcommand)); - auto markdown = state.forceString(*attr->value); + auto markdown = state.forceString(*attr->value, noPos, "while evaluating the lowdown help text"); RunPager pager; std::cout << renderMarkdownToTerminal(markdown) << "\n"; diff --git a/src/nix/prefetch.cc b/src/nix/prefetch.cc index ce3288dc1..fc3823406 100644 --- a/src/nix/prefetch.cc +++ b/src/nix/prefetch.cc @@ -28,17 +28,17 @@ std::string resolveMirrorUrl(EvalState & state, const std::string & url) Value vMirrors; // FIXME: use nixpkgs flake state.eval(state.parseExprFromString("import <nixpkgs/pkgs/build-support/fetchurl/mirrors.nix>", "."), vMirrors); - state.forceAttrs(vMirrors, noPos); + state.forceAttrs(vMirrors, noPos, "while evaluating the set of all mirrors"); auto mirrorList = vMirrors.attrs->find(state.symbols.create(mirrorName)); if (mirrorList == vMirrors.attrs->end()) throw Error("unknown mirror name '%s'", mirrorName); - state.forceList(*mirrorList->value, noPos); + state.forceList(*mirrorList->value, noPos, "while evaluating one mirror configuration"); if (mirrorList->value->listSize() < 1) throw Error("mirror URL '%s' did not expand to anything", url); - std::string mirror(state.forceString(*mirrorList->value->listElems()[0])); + std::string mirror(state.forceString(*mirrorList->value->listElems()[0], noPos, "while evaluating the first available mirror")); return mirror + (hasSuffix(mirror, "/") ? "" : "/") + s.substr(p + 1); } @@ -196,29 +196,29 @@ static int main_nix_prefetch_url(int argc, char * * argv) Value vRoot; state->evalFile(path, vRoot); Value & v(*findAlongAttrPath(*state, attrPath, autoArgs, vRoot).first); - state->forceAttrs(v, noPos); + state->forceAttrs(v, noPos, "while evaluating the source attribute to prefetch"); /* Extract the URL. */ auto * attr = v.attrs->get(state->symbols.create("urls")); if (!attr) throw Error("attribute 'urls' missing"); - state->forceList(*attr->value, noPos); + state->forceList(*attr->value, noPos, "while evaluating the urls to prefetch"); if (attr->value->listSize() < 1) throw Error("'urls' list is empty"); - url = state->forceString(*attr->value->listElems()[0]); + url = state->forceString(*attr->value->listElems()[0], noPos, "while evaluating the first url from the urls list"); /* Extract the hash mode. */ auto attr2 = v.attrs->get(state->symbols.create("outputHashMode")); if (!attr2) printInfo("warning: this does not look like a fetchurl call"); else - unpack = state->forceString(*attr2->value) == "recursive"; + unpack = state->forceString(*attr2->value, noPos, "while evaluating the outputHashMode of the source to prefetch") == "recursive"; /* Extract the name. */ if (!name) { auto attr3 = v.attrs->get(state->symbols.create("name")); if (!attr3) - name = state->forceString(*attr3->value); + name = state->forceString(*attr3->value, noPos, "while evaluating the name of the source to prefetch"); } } diff --git a/src/nix/upgrade-nix.cc b/src/nix/upgrade-nix.cc index 2d2453395..17796d6b8 100644 --- a/src/nix/upgrade-nix.cc +++ b/src/nix/upgrade-nix.cc @@ -144,7 +144,7 @@ struct CmdUpgradeNix : MixDryRun, StoreCommand Bindings & bindings(*state->allocBindings(0)); auto v2 = findAlongAttrPath(*state, settings.thisSystem, bindings, *v).first; - return store->parseStorePath(state->forceString(*v2)); + return store->parseStorePath(state->forceString(*v2, noPos, "while evaluating the path tho latest nix version")); } }; |