From 4cffb130e385bc3f4c5ca0482ad8c4dd22229cfe Mon Sep 17 00:00:00 2001 From: Ben Burdette Date: Fri, 11 Feb 2022 14:14:25 -0700 Subject: [PATCH] for primops, enter the debugger at the last DebugTrace in the stack --- src/libexpr/eval.cc | 13 +++- src/libexpr/eval.hh | 2 + src/libexpr/nixexpr.cc | 2 +- src/libexpr/primops.cc | 167 +++++++++++++++++++++-------------------- 4 files changed, 99 insertions(+), 85 deletions(-) diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 79bdaff47..71a28bafa 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -437,7 +437,7 @@ EvalState::EvalState( , emptyBindings(0) , store(store) , buildStore(buildStore ? buildStore : store) - , debugStop(true) + , debugStop(false) , regexCache(makeRegexCache()) #if HAVE_BOEHMGC , valueAllocCache(std::allocate_shared(traceable_allocator(), nullptr)) @@ -787,6 +787,17 @@ LocalNoInlineNoReturn(void throwEvalError(const char * s, const string & s2, Eva throw error; } +void EvalState::debug_throw(Error e) { + // 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 (debuggerHook && !debugTraces.empty()) { + DebugTrace &last = debugTraces.front(); + debuggerHook(&e, last.env, last.expr); + } + throw e; +} + LocalNoInlineNoReturn(void throwEvalError(const Pos & pos, const char * s, Env & env, Expr *expr)) { auto error = EvalError({ diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh index a7d1207f2..1390c8885 100644 --- a/src/libexpr/eval.hh +++ b/src/libexpr/eval.hh @@ -118,6 +118,8 @@ public: bool debugStop; std::list debugTraces; + void debug_throw(Error e); + private: SrcToStore srcToStore; diff --git a/src/libexpr/nixexpr.cc b/src/libexpr/nixexpr.cc index 41ee92d27..e09bd9484 100644 --- a/src/libexpr/nixexpr.cc +++ b/src/libexpr/nixexpr.cc @@ -305,7 +305,7 @@ void ExprVar::bindVars(const std::shared_ptr &env) if (withLevel == -1) { throw UndefinedVarError({ - .msg = hintfmt("undefined variable (ExprVar bindvars) '%1%'", name), + .msg = hintfmt("undefined variable '%1%'", name), .errPos = pos }); } diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc index 3b429f328..956c55e49 100644 --- a/src/libexpr/primops.cc +++ b/src/libexpr/primops.cc @@ -46,7 +46,7 @@ StringMap EvalState::realiseContext(const PathSet & context) auto [ctxS, outputName] = decodeContext(i); auto ctx = store->parseStorePath(ctxS); if (!store->isValidPath(ctx)) - throw InvalidPathError(store->printStorePath(ctx)); + debug_throw(InvalidPathError(store->printStorePath(ctx))); if (!outputName.empty() && ctx.isDerivation()) { drvs.push_back({ctx, {outputName}}); } else { @@ -57,9 +57,9 @@ StringMap EvalState::realiseContext(const PathSet & context) if (drvs.empty()) return {}; if (!evalSettings.enableImportFromDerivation) - throw Error( + debug_throw(Error( "cannot build '%1%' during evaluation because the option 'allow-import-from-derivation' is disabled", - store->printStorePath(drvs.begin()->drvPath)); + store->printStorePath(drvs.begin()->drvPath))); /* Build/substitute the context. */ std::vector buildReqs; @@ -71,8 +71,8 @@ StringMap EvalState::realiseContext(const PathSet & context) auto outputPaths = store->queryDerivationOutputMap(drvPath); for (auto & outputName : outputs) { if (outputPaths.count(outputName) == 0) - throw Error("derivation '%s' does not have an output named '%s'", - store->printStorePath(drvPath), outputName); + debug_throw(Error("derivation '%s' does not have an output named '%s'", + store->printStorePath(drvPath), outputName)); res.insert_or_assign( downstreamPlaceholder(*store, drvPath, outputName), store->printStorePath(outputPaths.at(outputName)) @@ -318,17 +318,17 @@ void prim_importNative(EvalState & state, const Pos & pos, Value * * args, Value void *handle = dlopen(path.c_str(), RTLD_LAZY | RTLD_LOCAL); if (!handle) - throw EvalError("could not open '%1%': %2%", path, dlerror()); + state.debug_throw(EvalError("could not open '%1%': %2%", path, dlerror())); dlerror(); ValueInitializer func = (ValueInitializer) dlsym(handle, sym.c_str()); if(!func) { char *message = dlerror(); if (message) - throw EvalError("could not load symbol '%1%' from '%2%': %3%", sym, path, message); + state.debug_throw(EvalError("could not load symbol '%1%' from '%2%': %3%", sym, path, message)); else - throw EvalError("symbol '%1%' from '%2%' resolved to NULL when a function pointer was expected", - sym, path); + state.debug_throw(EvalError("symbol '%1%' from '%2%' resolved to NULL when a function pointer was expected", + sym, path)); } (func)(state, v); @@ -344,10 +344,10 @@ void prim_exec(EvalState & state, const Pos & pos, Value * * args, Value & v) auto elems = args[0]->listElems(); auto count = args[0]->listSize(); if (count == 0) { - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("at least one argument to 'exec' required"), .errPos = pos - }); + })); } PathSet context; auto program = state.coerceToString(pos, *elems[0], context, false, false).toOwned(); @@ -358,11 +358,11 @@ void prim_exec(EvalState & state, const Pos & pos, Value * * args, Value & v) try { auto _ = state.realiseContext(context); // FIXME: Handle CA derivations } catch (InvalidPathError & e) { - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("cannot execute '%1%', since path '%2%' is not valid", program, e.path), .errPos = pos - }); + })); } auto output = runProgram(program, true, commandArgs); @@ -545,7 +545,7 @@ struct CompareValues if (v1->type() == nInt && v2->type() == nFloat) return v1->integer < v2->fpoint; if (v1->type() != v2->type()) - throw EvalError("cannot compare %1% with %2%", showType(*v1), showType(*v2)); + state.debug_throw(EvalError("cannot compare %1% with %2%", showType(*v1), showType(*v2))); switch (v1->type()) { case nInt: return v1->integer < v2->integer; @@ -567,7 +567,8 @@ struct CompareValues } } default: - throw EvalError("cannot compare %1% with %2%", showType(*v1), showType(*v2)); + state.debug_throw(EvalError("cannot compare %1% with %2%", showType(*v1), showType(*v2))); + return false; } } }; @@ -597,10 +598,10 @@ static Bindings::iterator getAttr( Pos aPos = *attrSet->pos; if (aPos == noPos) { - throw TypeError({ + state.debug_throw(TypeError({ .msg = errorMsg, .errPos = pos, - }); + })); } else { auto e = TypeError({ .msg = errorMsg, @@ -610,7 +611,7 @@ static Bindings::iterator getAttr( // Adding another trace for the function name to make it clear // which call received wrong arguments. e.addTrace(pos, hintfmt("while invoking '%s'", funcName)); - throw e; + state.debug_throw(e); } } @@ -664,10 +665,10 @@ static void prim_genericClosure(EvalState & state, const Pos & pos, Value * * ar Bindings::iterator key = e->attrs->find(state.sKey); if (key == e->attrs->end()) - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("attribute 'key' required"), .errPos = pos - }); + })); state.forceValue(*key->value, pos); if (!doneKeys.insert(key->value).second) continue; @@ -734,7 +735,7 @@ static RegisterPrimOp primop_abort({ { PathSet context; string s = state.coerceToString(pos, *args[0], context).toOwned(); - throw Abort("evaluation aborted with the following error message: '%1%'", s); + state.debug_throw(Abort("evaluation aborted with the following error message: '%1%'", s)); } }); @@ -752,7 +753,7 @@ static RegisterPrimOp primop_throw({ { PathSet context; string s = state.coerceToString(pos, *args[0], context).toOwned(); - throw ThrownError(s); + state.debug_throw(ThrownError(s)); } }); @@ -1006,37 +1007,37 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * * if (s == "recursive") ingestionMethod = FileIngestionMethod::Recursive; else if (s == "flat") ingestionMethod = FileIngestionMethod::Flat; else - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("invalid value '%s' for 'outputHashMode' attribute", s), .errPos = posDrvName - }); + })); }; auto handleOutputs = [&](const Strings & ss) { outputs.clear(); for (auto & j : ss) { if (outputs.find(j) != outputs.end()) - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("duplicate derivation output '%1%'", j), .errPos = posDrvName - }); + })); /* !!! Check whether j is a valid attribute name. */ /* Derivations cannot be named ‘drv’, because then we'd have an attribute ‘drvPath’ in the resulting set. */ if (j == "drv") - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("invalid derivation output name 'drv'" ), .errPos = posDrvName - }); + })); outputs.insert(j); } if (outputs.empty()) - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("derivation cannot have an empty set of outputs"), .errPos = posDrvName - }); + })); }; try { @@ -1155,23 +1156,23 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * * /* Do we have all required attributes? */ if (drv.builder == "") - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("required attribute 'builder' missing"), .errPos = posDrvName - }); + })); if (drv.platform == "") - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("required attribute 'system' missing"), .errPos = posDrvName - }); + })); /* Check whether the derivation name is valid. */ if (isDerivation(drvName)) - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("derivation names are not allowed to end in '%s'", drvExtension), .errPos = posDrvName - }); + })); if (outputHash) { /* Handle fixed-output derivations. @@ -1179,10 +1180,10 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * * Ignore `__contentAddressed` because fixed output derivations are already content addressed. */ if (outputs.size() != 1 || *(outputs.begin()) != "out") - throw Error({ + state.debug_throw(Error({ .msg = hintfmt("multiple outputs are not supported in fixed-output derivations"), .errPos = posDrvName - }); + })); std::optional ht = parseHashTypeOpt(outputHashAlgo); Hash h = newHashAllowEmpty(*outputHash, ht); @@ -1350,10 +1351,10 @@ static RegisterPrimOp primop_toPath({ static void prim_storePath(EvalState & state, const Pos & pos, Value * * args, Value & v) { if (evalSettings.pureEval) - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("'%s' is not allowed in pure evaluation mode", "builtins.storePath"), .errPos = pos - }); + })); PathSet context; Path path = state.checkSourcePath(state.coerceToPath(pos, *args[0], context)); @@ -1362,10 +1363,10 @@ static void prim_storePath(EvalState & state, const Pos & pos, Value * * args, V e.g. nix-push does the right thing. */ if (!state.store->isStorePath(path)) path = canonPath(path, true); if (!state.store->isInStore(path)) - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("path '%1%' is not in the Nix store", path), .errPos = pos - }); + })); auto path2 = state.store->toStorePath(path).first; if (!settings.readOnlyMode) state.store->ensurePath(path2); @@ -1468,7 +1469,7 @@ static void prim_readFile(EvalState & state, const Pos & pos, Value * * args, Va auto path = realisePath(state, pos, *args[0]); string s = readFile(path); if (s.find((char) 0) != string::npos) - throw Error("the contents of the file '%1%' cannot be represented as a Nix string", path); + state.debug_throw(Error("the contents of the file '%1%' cannot be represented as a Nix string", path)); StorePathSet refs; if (state.store->isInStore(path)) { try { @@ -1520,10 +1521,10 @@ static void prim_findFile(EvalState & state, const Pos & pos, Value * * args, Va auto rewrites = state.realiseContext(context); path = rewriteStrings(path, rewrites); } catch (InvalidPathError & e) { - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("cannot find '%1%', since path '%2%' is not valid", path, e.path), .errPos = pos - }); + })); } @@ -1547,10 +1548,10 @@ static void prim_hashFile(EvalState & state, const Pos & pos, Value * * args, Va auto type = state.forceStringNoCtx(*args[0], pos); std::optional ht = parseHashType(type); if (!ht) - throw Error({ + state.debug_throw(Error({ .msg = hintfmt("unknown hash type '%1%'", type), .errPos = pos - }); + })); auto path = realisePath(state, pos, *args[1]); @@ -1787,13 +1788,13 @@ static void prim_toFile(EvalState & state, const Pos & pos, Value * * args, Valu for (auto path : context) { if (path.at(0) != '/') - throw EvalError( { + state.debug_throw(EvalError( { .msg = hintfmt( "in 'toFile': the file named '%1%' must not contain a reference " "to a derivation but contains (%2%)", name, path), .errPos = pos - }); + })); refs.insert(state.store->parseStorePath(path)); } @@ -1951,7 +1952,7 @@ static void addPath( ? state.store->computeStorePathForPath(name, path, method, htSHA256, filter).first : state.store->addToStore(name, path, method, htSHA256, filter, state.repair, refs)); if (expectedHash && expectedStorePath != state.store->parseStorePath(dstPath)) - throw Error("store path mismatch in (possibly filtered) path added from '%s'", path); + state.debug_throw(Error("store path mismatch in (possibly filtered) path added from '%s'", path)); } else dstPath = state.store->printStorePath(*expectedStorePath); @@ -1973,12 +1974,12 @@ static void prim_filterSource(EvalState & state, const Pos & pos, Value * * args state.forceValue(*args[0], pos); if (args[0]->type() != nFunction) - throw TypeError({ + state.debug_throw(TypeError({ .msg = hintfmt( "first argument in call to 'filterSource' is not a function but %1%", showType(*args[0])), .errPos = pos - }); + })); addPath(state, pos, std::string(baseNameOf(path)), path, args[0], FileIngestionMethod::Recursive, std::nullopt, v, context); } @@ -2062,16 +2063,16 @@ static void prim_path(EvalState & state, const Pos & pos, Value * * args, Value else if (n == "sha256") expectedHash = newHashAllowEmpty(state.forceStringNoCtx(*attr.value, *attr.pos), htSHA256); else - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("unsupported argument '%1%' to 'addPath'", attr.name), .errPos = *attr.pos - }); + })); } if (path.empty()) - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("'path' required"), .errPos = pos - }); + })); if (name.empty()) name = baseNameOf(path); @@ -2442,10 +2443,10 @@ static void prim_functionArgs(EvalState & state, const Pos & pos, Value * * args return; } if (!args[0]->isLambda()) - throw TypeError({ + state.debug_throw(TypeError({ .msg = hintfmt("'functionArgs' requires a function"), .errPos = pos - }); + })); if (!args[0]->lambda.fun->hasFormals()) { v.mkAttrs(&state.emptyBindings); @@ -2620,10 +2621,10 @@ static void elemAt(EvalState & state, const Pos & pos, Value & list, int n, Valu { state.forceList(list, pos); if (n < 0 || (unsigned int) n >= list.listSize()) - throw Error({ - .msg = hintfmt("list index %1% is out of bounds", n), + state.debug_throw(Error({ + .msg = hintfmt("list index %1% is out of boundz", n), .errPos = pos - }); + })); state.forceValue(*list.listElems()[n], pos); v = *list.listElems()[n]; } @@ -2668,10 +2669,10 @@ static void prim_tail(EvalState & state, const Pos & pos, Value * * args, Value { state.forceList(*args[0], pos); if (args[0]->listSize() == 0) - throw Error({ + state.debug_throw(Error({ .msg = hintfmt("'tail' called on an empty list"), .errPos = pos - }); + })); state.mkList(v, args[0]->listSize() - 1); for (unsigned int n = 0; n < v.listSize(); ++n) @@ -2906,10 +2907,10 @@ static void prim_genList(EvalState & state, const Pos & pos, Value * * args, Val auto len = state.forceInt(*args[1], pos); if (len < 0) - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("cannot create list of size %1%", len), .errPos = pos - }); + })); state.mkList(v, len); @@ -3213,10 +3214,10 @@ static void prim_div(EvalState & state, const Pos & pos, Value * * args, Value & NixFloat f2 = state.forceFloat(*args[1], pos); if (f2 == 0) - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("division by zero"), .errPos = pos - }); + })); if (args[0]->type() == nFloat || args[1]->type() == nFloat) { v.mkFloat(state.forceFloat(*args[0], pos) / state.forceFloat(*args[1], pos)); @@ -3225,10 +3226,10 @@ static void prim_div(EvalState & state, const Pos & pos, Value * * args, Value & NixInt i2 = state.forceInt(*args[1], pos); /* Avoid division overflow as it might raise SIGFPE. */ if (i1 == std::numeric_limits::min() && i2 == -1) - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("overflow in integer division"), .errPos = pos - }); + })); v.mkInt(i1 / i2); } @@ -3356,10 +3357,10 @@ static void prim_substring(EvalState & state, const Pos & pos, Value * * args, V auto s = state.coerceToString(pos, *args[2], context); if (start < 0) - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("negative start position in 'substring'"), .errPos = pos - }); + })); v.mkString((unsigned int) start >= s->size() ? "" : s->substr(start, len), context); } @@ -3407,10 +3408,10 @@ static void prim_hashString(EvalState & state, const Pos & pos, Value * * args, auto type = state.forceStringNoCtx(*args[0], pos); std::optional ht = parseHashType(type); if (!ht) - throw Error({ + state.debug_throw(Error({ .msg = hintfmt("unknown hash type '%1%'", type), .errPos = pos - }); + })); PathSet context; // discarded auto s = state.forceString(*args[1], context, pos); @@ -3480,15 +3481,15 @@ void prim_match(EvalState & state, const Pos & pos, Value * * args, Value & v) } catch (std::regex_error &e) { if (e.code() == std::regex_constants::error_space) { // limit is _GLIBCXX_REGEX_STATE_LIMIT for libstdc++ - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("memory limit exceeded by regular expression '%s'", re), .errPos = pos - }); + })); } else { - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("invalid regular expression '%s'", re), .errPos = pos - }); + })); } } } @@ -3585,15 +3586,15 @@ void prim_split(EvalState & state, const Pos & pos, Value * * args, Value & v) } catch (std::regex_error &e) { if (e.code() == std::regex_constants::error_space) { // limit is _GLIBCXX_REGEX_STATE_LIMIT for libstdc++ - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("memory limit exceeded by regular expression '%s'", re), .errPos = pos - }); + })); } else { - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("invalid regular expression '%s'", re), .errPos = pos - }); + })); } } } @@ -3670,10 +3671,10 @@ static void prim_replaceStrings(EvalState & state, const Pos & pos, Value * * ar state.forceList(*args[0], pos); state.forceList(*args[1], pos); if (args[0]->listSize() != args[1]->listSize()) - throw EvalError({ + state.debug_throw(EvalError({ .msg = hintfmt("'from' and 'to' arguments to 'replaceStrings' have different lengths"), .errPos = pos - }); + })); vector from; from.reserve(args[0]->listSize());