diff options
| -rw-r--r-- | src/libexpr/eval.hh | 3 | ||||
| -rw-r--r-- | src/libexpr/primops.cc | 38 | ||||
| -rw-r--r-- | src/libexpr/primops/context.cc | 132 | ||||
| -rw-r--r-- | tests/lang/eval-okay-context-introspection.exp | 1 | ||||
| -rw-r--r-- | tests/lang/eval-okay-context-introspection.nix | 22 |
5 files changed, 158 insertions, 38 deletions
diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh index d0f298e16..9fe387891 100644 --- a/src/libexpr/eval.hh +++ b/src/libexpr/eval.hh @@ -316,6 +316,9 @@ private: /* Return a string representing the type of the value `v'. */ string showType(const Value & v); +/* Decode a context string ‘!<name>!<path>’ into a pair <path, + name>. */ +std::pair<string, string> decodeContext(const string & s); /* If `path' refers to a directory, then append "/default.nix". */ Path resolveExprPath(Path path); diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc index 113ceaf29..0da9f702f 100644 --- a/src/libexpr/primops.cc +++ b/src/libexpr/primops.cc @@ -1780,41 +1780,6 @@ static void prim_stringLength(EvalState & state, const Pos & pos, Value * * args } -static void prim_unsafeDiscardStringContext(EvalState & state, const Pos & pos, Value * * args, Value & v) -{ - PathSet context; - string s = state.coerceToString(pos, *args[0], context); - mkString(v, s, PathSet()); -} - - -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()); -} - - -/* 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; - 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); -} - - /* Return the cryptographic hash of a string in base-16. */ static void prim_hashString(EvalState & state, const Pos & pos, Value * * args, Value & v) { @@ -2285,9 +2250,6 @@ void EvalState::createBaseEnv() addPrimOp("toString", 1, prim_toString); addPrimOp("__substring", 3, prim_substring); addPrimOp("__stringLength", 1, prim_stringLength); - addPrimOp("__hasContext", 1, prim_hasContext); - addPrimOp("__unsafeDiscardStringContext", 1, prim_unsafeDiscardStringContext); - addPrimOp("__unsafeDiscardOutputDependency", 1, prim_unsafeDiscardOutputDependency); addPrimOp("__hashString", 2, prim_hashString); addPrimOp("__match", 2, prim_match); addPrimOp("__split", 2, prim_split); diff --git a/src/libexpr/primops/context.cc b/src/libexpr/primops/context.cc new file mode 100644 index 000000000..6849aa261 --- /dev/null +++ b/src/libexpr/primops/context.cc @@ -0,0 +1,132 @@ +#include "primops.hh" +#include "eval-inline.hh" + +namespace nix { + +static void prim_unsafeDiscardStringContext(EvalState & state, const Pos & pos, Value * * args, Value & v) +{ + PathSet context; + 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; + 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, but at least one must be set to something other + than the default. +*/ +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; + 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); + } + } + infoVal.attrs->sort(); + } + v.attrs->sort(); +} + +static RegisterPrimOp r4("__getContext", 1, prim_getContext); + +} diff --git a/tests/lang/eval-okay-context-introspection.exp b/tests/lang/eval-okay-context-introspection.exp new file mode 100644 index 000000000..27ba77dda --- /dev/null +++ b/tests/lang/eval-okay-context-introspection.exp @@ -0,0 +1 @@ +true diff --git a/tests/lang/eval-okay-context-introspection.nix b/tests/lang/eval-okay-context-introspection.nix new file mode 100644 index 000000000..d9b2ea354 --- /dev/null +++ b/tests/lang/eval-okay-context-introspection.nix @@ -0,0 +1,22 @@ +let + drv = derivation { + name = "fail"; + builder = "/bin/false"; + system = "x86_64-linux"; + outputs = [ "out" "foo" ]; + }; + + path = "${./eval-okay-context-introspection.nix}"; + + desired-context = { + "${builtins.unsafeDiscardStringContext path}" = { + path = true; + }; + "${builtins.unsafeDiscardStringContext drv.drvPath}" = { + outputs = [ "foo" "out" ]; + allOutputs = true; + }; + }; + + legit-context = "${path}${drv.outPath}${drv.foo.outPath}${drv.drvPath}"; +in builtins.getContext legit-context == desired-context |