1 files changed, 156 insertions, 0 deletions
diff --git a/third_party/nix/src/nix-env/user-env.cc b/third_party/nix/src/nix-env/user-env.cc
new file mode 100644
index 0000000000..7b9a882811
--- /dev/null
+++ b/third_party/nix/src/nix-env/user-env.cc
@@ -0,0 +1,156 @@
+#include "user-env.hh"
+#include "util.hh"
+#include "derivations.hh"
+#include "store-api.hh"
+#include "globals.hh"
+#include "shared.hh"
+#include "eval.hh"
+#include "eval-inline.hh"
+#include "profiles.hh"
+
+
+namespace nix {
+
+
+DrvInfos queryInstalled(EvalState & state, const Path & userEnv)
+{
+    DrvInfos elems;
+    Path manifestFile = userEnv + "/manifest.nix";
+    if (pathExists(manifestFile)) {
+        Value v;
+        state.evalFile(manifestFile, v);
+        Bindings & bindings(*state.allocBindings(0));
+        getDerivations(state, v, "", bindings, elems, false);
+    }
+    return elems;
+}
+
+
+bool createUserEnv(EvalState & state, DrvInfos & elems,
+    const Path & profile, bool keepDerivations,
+    const string & lockToken)
+{
+    /* Build the components in the user environment, if they don't
+       exist already. */
+    PathSet drvsToBuild;
+    for (auto & i : elems)
+        if (i.queryDrvPath() != "")
+            drvsToBuild.insert(i.queryDrvPath());
+
+    debug(format("building user environment dependencies"));
+    state.store->buildPaths(drvsToBuild, state.repair ? bmRepair : bmNormal);
+
+    /* Construct the whole top level derivation. */
+    PathSet references;
+    Value manifest;
+    state.mkList(manifest, elems.size());
+    unsigned int n = 0;
+    for (auto & i : elems) {
+        /* Create a pseudo-derivation containing the name, system,
+           output paths, and optionally the derivation path, as well
+           as the meta attributes. */
+        Path drvPath = keepDerivations ? i.queryDrvPath() : "";
+
+        Value & v(*state.allocValue());
+        manifest.listElems()[n++] = &v;
+        state.mkAttrs(v, 16);
+
+        mkString(*state.allocAttr(v, state.sType), "derivation");
+        mkString(*state.allocAttr(v, state.sName), i.queryName());
+        auto system = i.querySystem();
+        if (!system.empty())
+            mkString(*state.allocAttr(v, state.sSystem), system);
+        mkString(*state.allocAttr(v, state.sOutPath), i.queryOutPath());
+        if (drvPath != "")
+            mkString(*state.allocAttr(v, state.sDrvPath), i.queryDrvPath());
+
+        // Copy each output meant for installation.
+        DrvInfo::Outputs outputs = i.queryOutputs(true);
+        Value & vOutputs = *state.allocAttr(v, state.sOutputs);
+        state.mkList(vOutputs, outputs.size());
+        unsigned int m = 0;
+        for (auto & j : outputs) {
+            mkString(*(vOutputs.listElems()[m++] = state.allocValue()), j.first);
+            Value & vOutputs = *state.allocAttr(v, state.symbols.create(j.first));
+            state.mkAttrs(vOutputs, 2);
+            mkString(*state.allocAttr(vOutputs, state.sOutPath), j.second);
+
+            /* This is only necessary when installing store paths, e.g.,
+               `nix-env -i /nix/store/abcd...-foo'. */
+            state.store->addTempRoot(j.second);
+            state.store->ensurePath(j.second);
+
+            references.insert(j.second);
+        }
+
+        // Copy the meta attributes.
+        Value & vMeta = *state.allocAttr(v, state.sMeta);
+        state.mkAttrs(vMeta, 16);
+        StringSet metaNames = i.queryMetaNames();
+        for (auto & j : metaNames) {
+            Value * v = i.queryMeta(j);
+            if (!v) continue;
+            vMeta.attrs->push_back(Attr(state.symbols.create(j), v));
+        }
+        vMeta.attrs->sort();
+        v.attrs->sort();
+
+        if (drvPath != "") references.insert(drvPath);
+    }
+
+    /* Also write a copy of the list of user environment elements to
+       the store; we need it for future modifications of the
+       environment. */
+    Path manifestFile = state.store->addTextToStore("env-manifest.nix",
+        (format("%1%") % manifest).str(), references);
+
+    /* Get the environment builder expression. */
+    Value envBuilder;
+    state.evalFile(state.findFile("nix/buildenv.nix"), envBuilder);
+
+    /* Construct a Nix expression that calls the user environment
+       builder with the manifest as argument. */
+    Value args, topLevel;
+    state.mkAttrs(args, 3);
+    mkString(*state.allocAttr(args, state.symbols.create("manifest")),
+        manifestFile, {manifestFile});
+    args.attrs->push_back(Attr(state.symbols.create("derivations"), &manifest));
+    args.attrs->sort();
+    mkApp(topLevel, envBuilder, args);
+
+    /* Evaluate it. */
+    debug("evaluating user environment builder");
+    state.forceValue(topLevel);
+    PathSet context;
+    Attr & aDrvPath(*topLevel.attrs->find(state.sDrvPath));
+    Path topLevelDrv = state.coerceToPath(aDrvPath.pos ? *(aDrvPath.pos) : noPos, *(aDrvPath.value), context);
+    Attr & aOutPath(*topLevel.attrs->find(state.sOutPath));
+    Path topLevelOut = state.coerceToPath(aOutPath.pos ? *(aOutPath.pos) : noPos, *(aOutPath.value), context);
+
+    /* Realise the resulting store expression. */
+    debug("building user environment");
+    state.store->buildPaths({topLevelDrv}, state.repair ? bmRepair : bmNormal);
+
+    /* Switch the current user environment to the output path. */
+    auto store2 = state.store.dynamic_pointer_cast<LocalFSStore>();
+
+    if (store2) {
+        PathLocks lock;
+        lockProfile(lock, profile);
+
+        Path lockTokenCur = optimisticLockProfile(profile);
+        if (lockToken != lockTokenCur) {
+            printError(format("profile '%1%' changed while we were busy; restarting") % profile);
+            return false;
+        }
+
+        debug(format("switching to new user environment"));
+        Path generation = createGeneration(ref<LocalFSStore>(store2), profile, topLevelOut);
+        switchLink(profile, generation);
+    }
+
+    return true;
+}
+
+
+}