Add 'third_party/nix/' from commit 'be66c7a6b24e3c3c6157fd37b86c7203d14acf10' r/724

git-subtree-dir: third_party/nix
git-subtree-mainline: cf8cd640c1adf74a3706efbcb0ea4625da106fb2
git-subtree-split: be66c7a6b24e3c3c6157fd37b86c7203d14acf10

1 files changed, 72 insertions, 0 deletions

diff --git a/third_party/nix/src/nix/build.cc b/third_party/nix/src/nix/build.cc
new file mode 100644
index 0000000000..b329ac38ac
--- /dev/null
+++ b/third_party/nix/src/nix/build.cc
@@ -0,0 +1,72 @@
+#include "command.hh"
+#include "common-args.hh"
+#include "shared.hh"
+#include "store-api.hh"
+
+using namespace nix;
+
+struct CmdBuild : MixDryRun, InstallablesCommand
+{
+    Path outLink = "result";
+
+    CmdBuild()
+    {
+        mkFlag()
+            .longName("out-link")
+            .shortName('o')
+            .description("path of the symlink to the build result")
+            .labels({"path"})
+            .dest(&outLink);
+
+        mkFlag()
+            .longName("no-link")
+            .description("do not create a symlink to the build result")
+            .set(&outLink, Path(""));
+    }
+
+    std::string name() override
+    {
+        return "build";
+    }
+
+    std::string description() override
+    {
+        return "build a derivation or fetch a store path";
+    }
+
+    Examples examples() override
+    {
+        return {
+            Example{
+                "To build and run GNU Hello from NixOS 17.03:",
+                "nix build -f channel:nixos-17.03 hello; ./result/bin/hello"
+            },
+            Example{
+                "To build the build.x86_64-linux attribute from release.nix:",
+                "nix build -f release.nix build.x86_64-linux"
+            },
+        };
+    }
+
+    void run(ref<Store> store) override
+    {
+        auto buildables = build(store, dryRun ? DryRun : Build, installables);
+
+        if (dryRun) return;
+
+        for (size_t i = 0; i < buildables.size(); ++i) {
+            auto & b(buildables[i]);
+
+            if (outLink != "")
+                for (auto & output : b.outputs)
+                    if (auto store2 = store.dynamic_pointer_cast<LocalFSStore>()) {
+                        std::string symlink = outLink;
+                        if (i) symlink += fmt("-%d", i);
+                        if (output.first != "out") symlink += fmt("-%s", output.first);
+                        store2->addPermRoot(output.second, absPath(symlink), true);
+                    }
+        }
+    }
+};
+
+static RegisterCommand r1(make_ref<CmdBuild>());