1 files changed, 327 insertions, 0 deletions
diff --git a/third_party/nix/src/nix/installables.cc b/third_party/nix/src/nix/installables.cc
new file mode 100644
index 000000000000..0e8bba39de20
--- /dev/null
+++ b/third_party/nix/src/nix/installables.cc
@@ -0,0 +1,327 @@
+#include "command.hh"
+#include "attr-path.hh"
+#include "common-eval-args.hh"
+#include "derivations.hh"
+#include "eval-inline.hh"
+#include "eval.hh"
+#include "get-drvs.hh"
+#include "store-api.hh"
+#include "shared.hh"
+
+#include <regex>
+
+namespace nix {
+
+SourceExprCommand::SourceExprCommand()
+{
+    mkFlag()
+        .shortName('f')
+        .longName("file")
+        .label("file")
+        .description("evaluate FILE rather than the default")
+        .dest(&file);
+}
+
+Value * SourceExprCommand::getSourceExpr(EvalState & state)
+{
+    if (vSourceExpr) return vSourceExpr;
+
+    auto sToplevel = state.symbols.create("_toplevel");
+
+    vSourceExpr = state.allocValue();
+
+    if (file != "")
+        state.evalFile(lookupFileArg(state, file), *vSourceExpr);
+
+    else {
+
+        /* Construct the installation source from $NIX_PATH. */
+
+        auto searchPath = state.getSearchPath();
+
+        state.mkAttrs(*vSourceExpr, 1024);
+
+        mkBool(*state.allocAttr(*vSourceExpr, sToplevel), true);
+
+        std::unordered_set<std::string> seen;
+
+        auto addEntry = [&](const std::string & name) {
+            if (name == "") return;
+            if (!seen.insert(name).second) return;
+            Value * v1 = state.allocValue();
+            mkPrimOpApp(*v1, state.getBuiltin("findFile"), state.getBuiltin("nixPath"));
+            Value * v2 = state.allocValue();
+            mkApp(*v2, *v1, mkString(*state.allocValue(), name));
+            mkApp(*state.allocAttr(*vSourceExpr, state.symbols.create(name)),
+                state.getBuiltin("import"), *v2);
+        };
+
+        for (auto & i : searchPath)
+            /* Hack to handle channels. */
+            if (i.first.empty() && pathExists(i.second + "/manifest.nix")) {
+                for (auto & j : readDirectory(i.second))
+                    if (j.name != "manifest.nix"
+                        && pathExists(fmt("%s/%s/default.nix", i.second, j.name)))
+                        addEntry(j.name);
+            } else
+                addEntry(i.first);
+
+        vSourceExpr->attrs->sort();
+    }
+
+    return vSourceExpr;
+}
+
+ref<EvalState> SourceExprCommand::getEvalState()
+{
+    if (!evalState)
+        evalState = std::make_shared<EvalState>(searchPath, getStore());
+    return ref<EvalState>(evalState);
+}
+
+Buildable Installable::toBuildable()
+{
+    auto buildables = toBuildables();
+    if (buildables.size() != 1)
+        throw Error("installable '%s' evaluates to %d derivations, where only one is expected", what(), buildables.size());
+    return std::move(buildables[0]);
+}
+
+struct InstallableStorePath : Installable
+{
+    Path storePath;
+
+    InstallableStorePath(const Path & storePath) : storePath(storePath) { }
+
+    std::string what() override { return storePath; }
+
+    Buildables toBuildables() override
+    {
+        return {{isDerivation(storePath) ? storePath : "", {{"out", storePath}}}};
+    }
+};
+
+struct InstallableValue : Installable
+{
+    SourceExprCommand & cmd;
+
+    InstallableValue(SourceExprCommand & cmd) : cmd(cmd) { }
+
+    Buildables toBuildables() override
+    {
+        auto state = cmd.getEvalState();
+
+        auto v = toValue(*state);
+
+        Bindings & autoArgs = *cmd.getAutoArgs(*state);
+
+        DrvInfos drvs;
+        getDerivations(*state, *v, "", autoArgs, drvs, false);
+
+        Buildables res;
+
+        PathSet drvPaths;
+
+        for (auto & drv : drvs) {
+            Buildable b{drv.queryDrvPath()};
+            drvPaths.insert(b.drvPath);
+
+            auto outputName = drv.queryOutputName();
+            if (outputName == "")
+                throw Error("derivation '%s' lacks an 'outputName' attribute", b.drvPath);
+
+            b.outputs.emplace(outputName, drv.queryOutPath());
+
+            res.push_back(std::move(b));
+        }
+
+        // Hack to recognize .all: if all drvs have the same drvPath,
+        // merge the buildables.
+        if (drvPaths.size() == 1) {
+            Buildable b{*drvPaths.begin()};
+            for (auto & b2 : res)
+                b.outputs.insert(b2.outputs.begin(), b2.outputs.end());
+            return {b};
+        } else
+            return res;
+    }
+};
+
+struct InstallableExpr : InstallableValue
+{
+    std::string text;
+
+    InstallableExpr(SourceExprCommand & cmd, const std::string & text)
+         : InstallableValue(cmd), text(text) { }
+
+    std::string what() override { return text; }
+
+    Value * toValue(EvalState & state) override
+    {
+        auto v = state.allocValue();
+        state.eval(state.parseExprFromString(text, absPath(".")), *v);
+        return v;
+    }
+};
+
+struct InstallableAttrPath : InstallableValue
+{
+    std::string attrPath;
+
+    InstallableAttrPath(SourceExprCommand & cmd, const std::string & attrPath)
+        : InstallableValue(cmd), attrPath(attrPath)
+    { }
+
+    std::string what() override { return attrPath; }
+
+    Value * toValue(EvalState & state) override
+    {
+        auto source = cmd.getSourceExpr(state);
+
+        Bindings & autoArgs = *cmd.getAutoArgs(state);
+
+        Value * v = findAlongAttrPath(state, attrPath, autoArgs, *source);
+        state.forceValue(*v);
+
+        return v;
+    }
+};
+
+// FIXME: extend
+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(
+    SourceExprCommand & cmd, ref<Store> store, std::vector<std::string> ss, bool useDefaultInstallables)
+{
+    std::vector<std::shared_ptr<Installable>> result;
+
+    if (ss.empty() && useDefaultInstallables) {
+        if (cmd.file == "")
+            cmd.file = ".";
+        ss = {""};
+    }
+
+    for (auto & s : ss) {
+
+        if (s.compare(0, 1, "(") == 0)
+            result.push_back(std::make_shared<InstallableExpr>(cmd, s));
+
+        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 if (s == "" || std::regex_match(s, attrPathRegex))
+            result.push_back(std::make_shared<InstallableAttrPath>(cmd, s));
+
+        else
+            throw UsageError("don't know what to do with argument '%s'", s);
+    }
+
+    return result;
+}
+
+std::shared_ptr<Installable> parseInstallable(
+    SourceExprCommand & cmd, ref<Store> store, const std::string & installable,
+    bool useDefaultInstallables)
+{
+    auto installables = parseInstallables(cmd, store, {installable}, false);
+    assert(installables.size() == 1);
+    return installables.front();
+}
+
+Buildables build(ref<Store> store, RealiseMode mode,
+    std::vector<std::shared_ptr<Installable>> installables)
+{
+    if (mode != Build)
+        settings.readOnlyMode = true;
+
+    Buildables buildables;
+
+    PathSet pathsToBuild;
+
+    for (auto & i : installables) {
+        for (auto & b : i->toBuildables()) {
+            if (b.drvPath != "") {
+                StringSet outputNames;
+                for (auto & output : b.outputs)
+                    outputNames.insert(output.first);
+                pathsToBuild.insert(
+                    b.drvPath + "!" + concatStringsSep(",", outputNames));
+            } else
+                for (auto & output : b.outputs)
+                    pathsToBuild.insert(output.second);
+            buildables.push_back(std::move(b));
+        }
+    }
+
+    if (mode == DryRun)
+        printMissing(store, pathsToBuild, lvlError);
+    else if (mode == Build)
+        store->buildPaths(pathsToBuild);
+
+    return buildables;
+}
+
+PathSet toStorePaths(ref<Store> store, RealiseMode mode,
+    std::vector<std::shared_ptr<Installable>> installables)
+{
+    PathSet outPaths;
+
+    for (auto & b : build(store, mode, installables))
+        for (auto & output : b.outputs)
+            outPaths.insert(output.second);
+
+    return outPaths;
+}
+
+Path toStorePath(ref<Store> store, RealiseMode mode,
+    std::shared_ptr<Installable> installable)
+{
+    auto paths = toStorePaths(store, mode, {installable});
+
+    if (paths.size() != 1)
+            throw Error("argument '%s' should evaluate to one store path", installable->what());
+
+    return *paths.begin();
+}
+
+PathSet toDerivations(ref<Store> store,
+    std::vector<std::shared_ptr<Installable>> installables, bool useDeriver)
+{
+    PathSet drvPaths;
+
+    for (auto & i : installables)
+        for (auto & b : i->toBuildables()) {
+            if (b.drvPath.empty()) {
+                if (!useDeriver)
+                    throw Error("argument '%s' did not evaluate to a derivation", i->what());
+                for (auto & output : b.outputs) {
+                    auto derivers = store->queryValidDerivers(output.second);
+                    if (derivers.empty())
+                        throw Error("'%s' does not have a known deriver", i->what());
+                    // FIXME: use all derivers?
+                    drvPaths.insert(*derivers.begin());
+                }
+            } else
+                drvPaths.insert(b.drvPath);
+        }
+
+    return drvPaths;
+}
+
+void InstallablesCommand::prepare()
+{
+    installables = parseInstallables(*this, getStore(), _installables, useDefaultInstallables());
+}
+
+void InstallableCommand::prepare()
+{
+    installable = parseInstallable(*this, getStore(), _installable, false);
+}
+
+}