nix: Make -f work for compatibility

src/nix/command.hh

@@ -74,23 +74,20 @@ struct Installable
 struct SourceExprCommand : virtual Args, StoreCommand, MixEvalArgs
 {
     std::optional<Path> file;
-    std::optional<std::string> flakeUri;
 
     SourceExprCommand();
 
-    /* Return a value representing the Nix expression from which we
-       are installing. This is either the file specified by ‘--file’,
-       or an attribute set constructed from $NIX_PATH, e.g. ‘{ nixpkgs
-       = import ...; bla = import ...; }’. */
-    Value * getSourceExpr(EvalState & state);
-
     ref<EvalState> getEvalState();
 
+    std::vector<std::shared_ptr<Installable>> parseInstallables(
+        ref<Store> store, std::vector<std::string> ss);
+
+    std::shared_ptr<Installable> parseInstallable(
+        ref<Store> store, const std::string & installable);
+
 private:
 
     std::shared_ptr<EvalState> evalState;
-
-    Value * vSourceExpr = 0;
 };
 
 enum RealiseMode { Build, NoBuild, DryRun };
@@ -108,8 +105,6 @@ struct InstallablesCommand : virtual Args, SourceExprCommand
 
     void prepare() override;
 
-    virtual bool useDefaultInstallables() { return true; }
-
 private:
 
     std::vector<std::string> _installables;
@@ -148,8 +143,6 @@ public:
     virtual void run(ref<Store> store, Paths storePaths) = 0;
 
     void run(ref<Store> store) override;
-
-    bool useDefaultInstallables() override { return !all; }
 };
 
 /* A command that operates on exactly one store path. */
@@ -174,10 +167,6 @@ struct RegisterCommand
     }
 };
 
-std::shared_ptr<Installable> parseInstallable(
-    SourceExprCommand & cmd, ref<Store> store, const std::string & installable,
-    bool useDefaultInstallables);
-
 Buildables build(ref<Store> store, RealiseMode mode,
     std::vector<std::shared_ptr<Installable>> installables);
 

src/nix/installables.cc

@@ -19,33 +19,10 @@ SourceExprCommand::SourceExprCommand()
         .shortName('f')
         .longName("file")
         .label("file")
-        .description("evaluate FILE rather than use the default installation source")
+        .description("evaluate a set of attributes from FILE (deprecated)")
         .dest(&file);
 }
 
-Value * SourceExprCommand::getSourceExpr(EvalState & state)
-{
-    if (vSourceExpr) return vSourceExpr;
-
-    vSourceExpr = state.allocValue();
-
-    if (file)
-        state.evalFile(lookupFileArg(state, *file), *vSourceExpr);
-    else {
-        // FIXME: remove "impure" hack, call some non-user-accessible
-        // variant of getFlake instead.
-        auto fun = state.parseExprFromString(
-             "builtins.mapAttrs (flakeName: flakeInfo:"
-             "  (getFlake (\"impure:\" + flakeInfo.uri)).${flakeName}.provides.packages or {})", "/");
-        auto vFun = state.allocValue();
-        state.eval(fun, *vFun);
-        auto vRegistry = makeFlakeRegistryValue(state);
-        mkApp(*vSourceExpr, *vFun, *vRegistry);
-    }
-
-    return vSourceExpr;
-}
-
 ref<EvalState> SourceExprCommand::getEvalState()
 {
     if (!evalState)
@@ -140,24 +117,20 @@ struct InstallableExpr : InstallableValue
 
 struct InstallableAttrPath : InstallableValue
 {
+    Value * v;
     std::string attrPath;
 
-    InstallableAttrPath(SourceExprCommand & cmd, const std::string & attrPath)
+    InstallableAttrPath(SourceExprCommand & cmd, Value * v, const std::string & attrPath)
-        : InstallableValue(cmd), attrPath(attrPath)
+        : InstallableValue(cmd), v(v), attrPath(attrPath)
     { }
 
     std::string what() override { return attrPath; }
 
     Value * toValue(EvalState & state) override
     {
-        auto source = cmd.getSourceExpr(state);
+        auto vRes = findAlongAttrPath(state, attrPath, *cmd.getAutoArgs(state), *v);
-
+        state.forceValue(*vRes);
-        Bindings & autoArgs = *cmd.getAutoArgs(state);
+        return vRes;
-
-        Value * v = findAlongAttrPath(state, attrPath, autoArgs, *source);
-        state.forceValue(*v);
-
-        return v;
     }
 };
 
@@ -202,41 +175,47 @@ struct InstallableFlake : InstallableValue
 std::string attrRegex = R"([A-Za-z_][A-Za-z0-9-_+]*)";
 static std::regex attrPathRegex(fmt(R"(%1%(\.%1%)*)", attrRegex));
 
-static std::vector<std::shared_ptr<Installable>> parseInstallables(
+std::vector<std::shared_ptr<Installable>> SourceExprCommand::parseInstallables(
-    SourceExprCommand & cmd, ref<Store> store, std::vector<std::string> ss, bool useDefaultInstallables)
+    ref<Store> store, std::vector<std::string> ss)
 {
     std::vector<std::shared_ptr<Installable>> result;
 
-    if (ss.empty() && useDefaultInstallables) {
+    if (file) {
-        if (cmd.file == "")
+        // FIXME: backward compatibility hack
-            cmd.file = ".";
+        evalSettings.pureEval = false;
+
+        auto state = getEvalState();
+        auto vFile = state->allocValue();
+        state->evalFile(lookupFileArg(*state, *file), *vFile);
+
+        if (ss.empty())
             ss = {""};
-    }
+
+        for (auto & s : ss)
+            result.push_back(std::make_shared<InstallableAttrPath>(*this, vFile, s));
+
+    } else {
 
         for (auto & s : ss) {
 
+            size_t colon;
+
             if (s.compare(0, 1, "(") == 0)
-            result.push_back(std::make_shared<InstallableExpr>(cmd, s));
+                result.push_back(std::make_shared<InstallableExpr>(*this, s));
 
-        /*
+            else if ((colon = s.rfind(':')) != std::string::npos) {
-        else if (s.find('/') != std::string::npos) {
-
-            auto path = store->toStorePath(store->followLinksToStore(s));
-
-            if (store->isStorePath(path))
-                result.push_back(std::make_shared<InstallableStorePath>(path));
-        }
-        */
-
-        else {
-            auto colon = s.rfind(':');
-            if (colon != std::string::npos) {
                 auto flakeRef = std::string(s, 0, colon);
                 auto attrPath = std::string(s, colon + 1);
-                result.push_back(std::make_shared<InstallableFlake>(cmd, FlakeRef(flakeRef), attrPath));
+                result.push_back(std::make_shared<InstallableFlake>(*this, FlakeRef(flakeRef), attrPath));
-            } else {
-                result.push_back(std::make_shared<InstallableFlake>(cmd, FlakeRef("nixpkgs"), s));
             }
+
+            else if (s.find('/') != std::string::npos) {
+                auto path = store->toStorePath(store->followLinksToStore(s));
+                result.push_back(std::make_shared<InstallableStorePath>(path));
+            }
+
+            else {
+                result.push_back(std::make_shared<InstallableFlake>(*this, FlakeRef("nixpkgs"), s));
             }
 
             /*
@@ -247,15 +226,15 @@ static std::vector<std::shared_ptr<Installable>> parseInstallables(
                 throw UsageError("don't know what to do with argument '%s'", s);
             */
         }
+    }
 
     return result;
 }
 
-std::shared_ptr<Installable> parseInstallable(
+std::shared_ptr<Installable> SourceExprCommand::parseInstallable(
-    SourceExprCommand & cmd, ref<Store> store, const std::string & installable,
+    ref<Store> store, const std::string & installable)
-    bool useDefaultInstallables)
 {
-    auto installables = parseInstallables(cmd, store, {installable}, false);
+    auto installables = parseInstallables(store, {installable});
     assert(installables.size() == 1);
     return installables.front();
 }
@@ -342,12 +321,12 @@ PathSet toDerivations(ref<Store> store,
 
 void InstallablesCommand::prepare()
 {
-    installables = parseInstallables(*this, getStore(), _installables, useDefaultInstallables());
+    installables = parseInstallables(getStore(), _installables);
 }
 
 void InstallableCommand::prepare()
 {
-    installable = parseInstallable(*this, getStore(), _installable, false);
+    installable = parseInstallable(getStore(), _installable);
 }
 
 }

src/nix/search.cc

@@ -257,7 +257,9 @@ struct CmdSearch : SourceExprCommand, MixJSON
 
                 auto cache = writeCache ? std::make_unique<JSONObject>(jsonCacheFile, false) : nullptr;
 
-                doExpr(getSourceExpr(*state), "", true, cache.get());
+                // FIXME
+                throw Error("NOT IMPLEMENTED");
+                //doExpr(getSourceExpr(*state), "", true, cache.get());
 
             } catch (std::exception &) {
                 /* Fun fact: catching std::ios::failure does not work

src/nix/why-depends.cc

@@ -74,9 +74,9 @@ struct CmdWhyDepends : SourceExprCommand
 
     void run(ref<Store> store) override
     {
-        auto package = parseInstallable(*this, store, _package, false);
+        auto package = parseInstallable(store, _package);
         auto packagePath = toStorePath(store, Build, package);
-        auto dependency = parseInstallable(*this, store, _dependency, false);
+        auto dependency = parseInstallable(store, _dependency);
         auto dependencyPath = toStorePath(store, NoBuild, dependency);
         auto dependencyPathHash = storePathToHash(dependencyPath);