#include "derivations.hh" #include "eval-inline.hh" #include "primops.hh" namespace nix { static void prim_unsafeDiscardStringContext(EvalState& state, const Pos& pos, Value** args, Value& v) { PathSet context; std::string s = state.coerceToString(pos, *args[0], context); mkString(v, s, PathSet()); } static RegisterPrimOp r1("__unsafeDiscardStringContext", 1, prim_unsafeDiscardStringContext); static void prim_hasContext(EvalState& state, const Pos& pos, Value** args, Value& v) { PathSet context; state.forceString(*args[0], context, pos); mkBool(v, !context.empty()); } static RegisterPrimOp r2("__hasContext", 1, prim_hasContext); /* Sometimes we want to pass a derivation path (i.e. pkg.drvPath) to a builder without causing the derivation to be built (for instance, in the derivation that builds NARs in nix-push, when doing source-only deployment). This primop marks the string context so that builtins.derivation adds the path to drv.inputSrcs rather than drv.inputDrvs. */ static void prim_unsafeDiscardOutputDependency(EvalState& state, const Pos& pos, Value** args, Value& v) { PathSet context; std::string s = state.coerceToString(pos, *args[0], context); PathSet context2; for (auto& p : context) { context2.insert(p.at(0) == '=' ? string(p, 1) : p); } mkString(v, s, context2); } static RegisterPrimOp r3("__unsafeDiscardOutputDependency", 1, prim_unsafeDiscardOutputDependency); /* Extract the context of a string as a structured Nix value. The context is represented as an attribute set whose keys are the paths in the context set and whose values are attribute sets with the following keys: path: True if the relevant path is in the context as a plain store path (i.e. the kind of context you get when interpolating a Nix path (e.g. ./.) into a string). False if missing. allOutputs: True if the relevant path is a derivation and it is in the context as a drv file with all of its outputs (i.e. the kind of context you get when referencing .drvPath of some derivation). False if missing. outputs: If a non-empty list, the relevant path is a derivation and the provided outputs are referenced in the context (i.e. the kind of context you get when referencing .outPath of some derivation). Empty list if missing. Note that for a given path any combination of the above attributes may be present. */ static void prim_getContext(EvalState& state, const Pos& pos, Value** args, Value& v) { struct ContextInfo { bool path = false; bool allOutputs = false; Strings outputs; }; PathSet context; state.forceString(*args[0], context, pos); auto contextInfos = std::map<Path, ContextInfo>(); for (const auto& p : context) { Path drv; std::string output; const Path* path = &p; if (p.at(0) == '=') { drv = string(p, 1); path = &drv; } else if (p.at(0) == '!') { std::pair<string, string> ctx = decodeContext(p); drv = ctx.first; output = ctx.second; path = &drv; } auto isPath = drv.empty(); auto isAllOutputs = (!drv.empty()) && output.empty(); auto iter = contextInfos.find(*path); if (iter == contextInfos.end()) { contextInfos.emplace( *path, ContextInfo{isPath, isAllOutputs, output.empty() ? Strings{} : Strings{std::move(output)}}); } else { if (isPath) iter->second.path = true; else if (isAllOutputs) iter->second.allOutputs = true; else iter->second.outputs.emplace_back(std::move(output)); } } state.mkAttrs(v, contextInfos.size()); auto sPath = state.symbols.Create("path"); auto sAllOutputs = state.symbols.Create("allOutputs"); for (const auto& info : contextInfos) { auto& infoVal = *state.allocAttr(v, state.symbols.Create(info.first)); state.mkAttrs(infoVal, 3); if (info.second.path) { mkBool(*state.allocAttr(infoVal, sPath), true); } if (info.second.allOutputs) mkBool(*state.allocAttr(infoVal, sAllOutputs), true); if (!info.second.outputs.empty()) { auto& outputsVal = *state.allocAttr(infoVal, state.sOutputs); state.mkList(outputsVal, info.second.outputs.size()); size_t i = 0; for (const auto& output : info.second.outputs) { mkString(*(outputsVal.listElems()[i++] = state.allocValue()), output); } } } } static RegisterPrimOp r4("__getContext", 1, prim_getContext); /* Append the given context to a given string. See the commentary above unsafeGetContext for details of the context representation. */ static void prim_appendContext(EvalState& state, const Pos& pos, Value** args, Value& v) { PathSet context; auto orig = state.forceString(*args[0], context, pos); state.forceAttrs(*args[1], pos); auto sPath = state.symbols.Create("path"); auto sAllOutputs = state.symbols.Create("allOutputs"); for (const auto& attr_iter : *args[1]->attrs) { const Attr* i = &attr_iter.second; // TODO(tazjin): get rid of this if (!state.store->isStorePath(i->name)) throw EvalError("Context key '%s' is not a store path, at %s", i->name, i->pos); if (!settings.readOnlyMode) { state.store->ensurePath(i->name); } state.forceAttrs(*i->value, *i->pos); auto iter = i->value->attrs->find(sPath); if (iter != i->value->attrs->end()) { if (state.forceBool(*iter->second.value, *iter->second.pos)) { context.insert(i->name); } } iter = i->value->attrs->find(sAllOutputs); if (iter != i->value->attrs->end()) { if (state.forceBool(*iter->second.value, *iter->second.pos)) { if (!isDerivation(i->name)) { throw EvalError( "Tried to add all-outputs context of %s, which is not a " "derivation, to a string, at %s", i->name, i->pos); } context.insert("=" + string(i->name)); } } iter = i->value->attrs->find(state.sOutputs); if (iter != i->value->attrs->end()) { state.forceList(*iter->second.value, *iter->second.pos); if (iter->second.value->listSize() && !isDerivation(i->name)) { throw EvalError( "Tried to add derivation output context of %s, which is not a " "derivation, to a string, at %s", i->name, i->pos); } for (unsigned int n = 0; n < iter->second.value->listSize(); ++n) { auto name = state.forceStringNoCtx(*iter->second.value->listElems()[n], *iter->second.pos); context.insert("!" + name + "!" + string(i->name)); } } } mkString(v, orig, context); } static RegisterPrimOp r5("__appendContext", 2, prim_appendContext); } // namespace nix