diff options
| -rw-r--r-- | src/libexpr/get-drvs.cc | 164 | ||||
| -rw-r--r-- | src/libexpr/get-drvs.hh | 2 |
2 files changed, 118 insertions, 48 deletions
diff --git a/src/libexpr/get-drvs.cc b/src/libexpr/get-drvs.cc index 8e3969aac..f5d0f0120 100644 --- a/src/libexpr/get-drvs.cc +++ b/src/libexpr/get-drvs.cc @@ -101,66 +101,134 @@ StorePath DrvInfo::queryOutPath() return *outPath; } +void DrvInfo::fillOutputs(bool withPaths) +{ + auto fillDefault = [&]() { + std::optional<StorePath> outPath = std::nullopt; + if (withPaths) { + outPath.emplace(this->queryOutPath()); + } + this->outputs.emplace("out", outPath); + }; + + // lol. lmao even. + if (this->attrs == nullptr) { + fillDefault(); + return; + } + + Attr * outputs = this->attrs->get(this->state->sOutputs); + if (outputs == nullptr) { + fillDefault(); + return; + } + + // NOTE(Qyriad): I don't think there is any codepath that can cause this to error. + this->state->forceList( + *outputs->value, + outputs->pos, + "while evaluating the 'outputs' attribute of a derivation" + ); + + for (auto [idx, elem] : enumerate(outputs->value->listItems())) { + // NOTE(Qyriad): This error should be *extremely* rare in practice. + // It is impossible to construct with `stdenv.mkDerivation`, + // `builtins.derivation`, or even `derivationStrict`. As far as we can tell, + // it is only possible by overriding a derivation attrset already created by + // one of those with `//` to introduce the failing `outputs` entry. + auto errMsg = fmt("while evaluating output %d of a derivation", idx); + std::string_view outputName = state->forceStringNoCtx( + *elem, + outputs->pos, + errMsg + ); + + if (withPaths) { + // Find the attr with this output's name... + Attr * out = this->attrs->get(this->state->symbols.create(outputName)); + if (out == nullptr) { + // FIXME: throw error? + continue; + } + + // Meanwhile we couldn't figure out any circumstances + // that cause this to error. + state->forceAttrs(*out->value, outputs->pos, errMsg); + + // ...and evaluate its `outPath` attribute. + Attr * outPath = out->value->attrs->get(this->state->sOutPath); + if (outPath == nullptr) { + continue; + // FIXME: throw error? + } + + NixStringContext context; + // And idk what could possibly cause this one to error + // that wouldn't error before here. + auto storePath = state->coerceToStorePath( + outPath->pos, + *outPath->value, + context, + errMsg + ); + this->outputs.emplace(outputName, storePath); + } else { + this->outputs.emplace(outputName, std::nullopt); + } + } +} DrvInfo::Outputs DrvInfo::queryOutputs(bool withPaths, bool onlyOutputsToInstall) { + // If we haven't already cached the outputs set, then do so now. if (outputs.empty()) { - /* Get the ‘outputs’ list. */ - Bindings::iterator i; - if (attrs && (i = attrs->find(state->sOutputs)) != attrs->end()) { - 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, "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, "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? - NixStringContext 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); - } - } else - outputs.emplace("out", withPaths ? std::optional{queryOutPath()} : std::nullopt); + // FIXME: this behavior seems kind of busted, since whether or not this + // DrvInfo will have paths is forever determined by the *first* call to + // this function?? + fillOutputs(withPaths); } + // Things that operate on derivations like packages, like `nix-env` and `nix build`, + // allow derivations to specify which outputs should be used in those user-facing + // cases if the user didn't specify an output explicitly. + // If the caller just wanted all the outputs for this derivation, though, + // then we're done here. if (!onlyOutputsToInstall || !attrs) return outputs; - Bindings::iterator i; - 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()) - throw Error("derivation does not have output '%s'", queryOutputName()); - result.insert(*out); - return result; + // Regardless of `meta.outputsToInstall`, though, you can select into a derivation + // output by its attribute, e.g. `pkgs.lix.dev`, which (lol?) sets the magic + // attribute `outputSpecified = true`, and changes the `outputName` attr to the + // explicitly selected-into output. + if (Attr * outSpecAttr = attrs->get(state->sOutputSpecified)) { + bool outputSpecified = this->state->forceBool( + *outSpecAttr->value, + outSpecAttr->pos, + "while evaluating the 'outputSpecified' attribute of a derivation" + ); + if (outputSpecified) { + auto maybeOut = outputs.find(queryOutputName()); + if (maybeOut == outputs.end()) { + throw Error("derivation does not have output '%s'", queryOutputName()); + } + return Outputs{*maybeOut}; + } } - else { - /* Check for `meta.outputsToInstall` and return `outputs` reduced to that. */ - const Value * outTI = queryMeta("outputsToInstall"); - if (!outTI) return outputs; - auto errMsg = Error("this derivation has bad 'meta.outputsToInstall'"); - /* ^ this shows during `nix-env -i` right under the bad derivation */ - if (!outTI->isList()) throw errMsg; - Outputs result; - for (auto elem : outTI->listItems()) { - if (elem->type() != nString) throw errMsg; - auto out = outputs.find(elem->string.s); - if (out == outputs.end()) throw errMsg; - result.insert(*out); - } - return result; + /* Check for `meta.outputsToInstall` and return `outputs` reduced to that. */ + const Value * outTI = queryMeta("outputsToInstall"); + if (!outTI) return outputs; + auto errMsg = Error("this derivation has bad 'meta.outputsToInstall'"); + /* ^ this shows during `nix-env -i` right under the bad derivation */ + if (!outTI->isList()) throw errMsg; + Outputs result; + for (auto elem : outTI->listItems()) { + if (elem->type() != nString) throw errMsg; + auto out = outputs.find(elem->string.s); + if (out == outputs.end()) throw errMsg; + result.insert(*out); } + return result; } diff --git a/src/libexpr/get-drvs.hh b/src/libexpr/get-drvs.hh index 44aac3015..525ac9803 100644 --- a/src/libexpr/get-drvs.hh +++ b/src/libexpr/get-drvs.hh @@ -37,6 +37,8 @@ private: bool checkMeta(Value & v); + void fillOutputs(bool withPaths = true); + public: /** * path towards the derivation |