Include the output name in the GC root link

Output names are now appended to resulting GC symlinks, e.g. by
nix-build.  For backwards compatibility, if the output is named "out",
nothing is appended.  E.g. doing "nix-build -A foo" on a derivation
that produces outputs "out", "bin" and "dev" will produce symlinks
"./result", "./result-bin" and "./result-dev", respectively.

4 files changed, 12 insertions, 17 deletions

diff --git a/src/libmain/shared.cc b/src/libmain/shared.cc
index d39816586404..026db4173af0 100644
--- a/src/libmain/shared.cc
+++ b/src/libmain/shared.cc
@@ -33,16 +33,6 @@ static void sigintHandler(int signo)
 }
 
 
-Path makeRootName(const Path & gcRoot, int & counter)
-{
-    counter++;
-    if (counter == 1)
-        return gcRoot;
-    else
-        return (format("%1%-%2%") % gcRoot % counter).str();
-}
-
-
 void printGCWarning()
 {
     static bool haveWarned = false;
diff --git a/src/libmain/shared.hh b/src/libmain/shared.hh
index 7849e10e3641..c69879a12356 100644
--- a/src/libmain/shared.hh
+++ b/src/libmain/shared.hh
@@ -26,7 +26,6 @@ MakeError(UsageError, nix::Error);
 class StoreAPI;
 
 /* Ugh.  No better place to put this. */
-Path makeRootName(const Path & gcRoot, int & counter);
 void printGCWarning();
 
 void printMissing(StoreAPI & store, const PathSet & paths);
diff --git a/src/nix-instantiate/nix-instantiate.cc b/src/nix-instantiate/nix-instantiate.cc
index d86c9fc84572..bca65d0728f5 100644
--- a/src/nix-instantiate/nix-instantiate.cc
+++ b/src/nix-instantiate/nix-instantiate.cc
@@ -64,9 +64,11 @@ void processExpr(EvalState & state, const Strings & attrPaths,
                     Path drvPath = i->queryDrvPath(state);
                     if (gcRoot == "")
                         printGCWarning();
-                    else
-                        drvPath = addPermRoot(*store, drvPath,
-                            makeRootName(gcRoot, rootNr), indirectRoot);
+                    else {
+                        Path rootName = gcRoot;
+                        if (++rootNr > 1) rootName += "-" + int2String(rootNr);
+                        drvPath = addPermRoot(*store, drvPath, rootName, indirectRoot);
+                    }
                     std::cout << format("%1%\n") % drvPath;
                 }
             }
diff --git a/src/nix-store/nix-store.cc b/src/nix-store/nix-store.cc
index c182dbe49c7a..d7b998faebb7 100644
--- a/src/nix-store/nix-store.cc
+++ b/src/nix-store/nix-store.cc
@@ -64,15 +64,19 @@ static PathSet realisePath(const Path & path)
     if (isDerivation(path)) {
         store->buildPaths(singleton<PathSet>(path));
         Derivation drv = derivationFromPath(*store, path);
+        rootNr++;
 
         PathSet outputs;
         foreach (DerivationOutputs::iterator, i, drv.outputs) {
             Path outPath = i->second.path;
             if (gcRoot == "")
                 printGCWarning();
-            else
-                outPath = addPermRoot(*store, outPath,
-                    makeRootName(gcRoot, rootNr), indirectRoot);
+            else {
+                Path rootName = gcRoot;
+                if (rootNr > 1) rootName += "-" + int2String(rootNr);
+                if (i->first != "out") rootName += "-" + i->first;
+                outPath = addPermRoot(*store, outPath, rootName, indirectRoot);
+            }
             outputs.insert(outPath);
         }
         return outputs;