* Unify exportReferencesGraph and exportBuildReferencesGraph, and make

sure that it works as expected when you pass it a derivation.  That
  is, we have to make sure that all build-time dependencies are built,
  and that they are all in the input closure (otherwise remote builds
  might fail, for example).  This is ensured at instantiation time by
  adding all derivations and their sources to inputDrvs and inputSrcs.

scripts/nix-push.in

@@ -140,11 +140,7 @@ while (scalar @tmp > 0) {
     my @tmp2 = @tmp[0..$n - 1];
     @tmp = @tmp[$n..scalar @tmp - 1];
 
-    # Note: we disable build hooks because of the impure path
+    my $pid = open(READ, "$binDir/nix-store --realise @tmp2|")
-    # reference (see above).  Even if that is fixed, using a hook
-    # probably wouldn't make that much sense; pumping lots of data
-    # around just to compress them won't gain that much.
-    my $pid = open(READ, "$binDir/nix-store --no-build-hook --realise @tmp2|")
         or die "cannot run nix-store";
     while (<READ>) {
         chomp;

src/libexpr/primops.cc

@@ -399,16 +399,29 @@ static Expr prim_derivationStrict(EvalState & state, const ATermVector & args)
     /* Everything in the context of the strings in the derivation
        attributes should be added as dependencies of the resulting
        derivation. */
-    for (PathSet::iterator i = context.begin(); i != context.end(); ++i) {
+    foreach (PathSet::iterator, i, context) {
         Path path = *i;
-        bool buildDrv = true;
+        
+        /* Paths marked with `=' denote that the path of a derivation
+           is explicitly passed to the builder.  Since that allows the
+           builder to gain access to every path in the dependency
+           graph of the derivation (including all outputs), all paths
+           in the graph must be added to this derivation's list of
+           inputs to ensure that they are available when the builder
+           runs. */
         if (path.at(0) == '=') {
-            buildDrv = false;
             path = string(path, 1);
+            PathSet refs; computeFSClosure(path, refs);
+            foreach (PathSet::iterator, j, refs) {
+                drv.inputSrcs.insert(*j);
+                if (isDerivation(*j))
+                    drv.inputDrvs[*j] = singleton<StringSet>("out");
+            }
         }
+        
         debug(format("derivation uses `%1%'") % path);
         assert(isStorePath(path));
-        if (buildDrv && isDerivation(path))
+        if (isDerivation(path))
             drv.inputDrvs[path] = singleton<StringSet>("out");
         else
             drv.inputSrcs.insert(path);
@@ -484,7 +497,7 @@ static Expr prim_derivationStrict(EvalState & state, const ATermVector & args)
     outAttrs.set(toATerm("outPath"),
         makeAttrRHS(makeStr(outPath, singleton<PathSet>(drvPath)), makeNoPos()));
     outAttrs.set(toATerm("drvPath"),
-        makeAttrRHS(makeStr(drvPath, singleton<PathSet>(drvPath)), makeNoPos()));
+        makeAttrRHS(makeStr(drvPath, singleton<PathSet>("=" + drvPath)), makeNoPos()));
 
     return makeAttrs(outAttrs);
 }
@@ -541,13 +554,6 @@ static Expr prim_storePath(EvalState & state, const ATermVector & args)
     Path path2 = toStorePath(path);
     if (!store->isValidPath(path2))
         throw EvalError(format("store path `%1%' is not valid") % path2);
-    /* If this is a derivation, mark it so it doesn't get built;
-       i.e. we want the dependency as a "source" dependency.  This is
-       to make nix-push work properly (we want it to create a NAR
-       archive of the derivation, not build the derivation as a
-       side-effect).  The `=' is a special marker that gets stripped
-       off by prim_derivationStrict. */
-    if (isDerivation(path2)) path2 = "=" + path2;
     context.insert(path2);
     return makeStr(path, context);
 }

src/libstore/build.cc

@@ -935,8 +935,6 @@ void DerivationGoal::inputsRealised()
     /* Second, the input sources. */
     foreach (PathSet::iterator, i, drv.inputSrcs)
         computeFSClosure(*i, inputPaths);
-        /* !!! if `*i' is a derivation, then add the closure of every
-           output in the dependency graph to `inputPaths'. */
 
     debug(format("added input paths %1%") % showPaths(inputPaths));
 
@@ -1534,53 +1532,25 @@ void DerivationGoal::startBuilder()
             throw BuildError(format("`exportReferencesGraph' contains an invalid path `%1%'")
                 % storePath);
 
-        /* Write closure info to `fileName'. */
+        /* If there are derivations in the graph, then include their
-        PathSet refs;
+           outputs as well.  This is useful if you want to do things
-        computeFSClosure(storePath, refs);
+           like passing all build-time dependencies of some path to a
-        /* !!! in secure Nix, the writing should be done on the
+           derivation that builds a NixOS DVD image. */
-           build uid for security (maybe). */
+        PathSet paths, paths2;
-        writeStringToFile(tmpDir + "/" + fileName,
+        computeFSClosure(storePath, paths);
-            makeValidityRegistration(refs, false, false));
+        paths2 = paths;
-    }
 
-    // The same for derivations
+        foreach (PathSet::iterator, j, paths2) {
-    // !!! urgh, cut&paste duplication
+            if (isDerivation(*j)) {
-    s = drv.env["exportBuildReferencesGraph"];
+                Derivation drv = derivationFromPath(*j);
-    ss = tokenizeString(s);
+                foreach (DerivationOutputs::iterator, k, drv.outputs)
-    if (ss.size() % 2 != 0)
+                    computeFSClosure(k->second.path, paths);
-        throw BuildError(format("odd number of tokens in `exportBuildReferencesGraph': `%1%'") % s);
+            }
-    for (Strings::iterator i = ss.begin(); i != ss.end(); ) {
+        }
-        string fileName = *i++;
-        checkStoreName(fileName); /* !!! abuse of this function */
-
-        /* Check that the store path is valid. */
-        Path storePath = *i++;
-        if (!isInStore(storePath))
-            throw BuildError(format("`exportBuildReferencesGraph' contains a non-store path `%1%'")
-                % storePath);
-        storePath = toStorePath(storePath);
-        if (!worker.store.isValidPath(storePath))
-            throw BuildError(format("`exportBuildReferencesGraph' contains an invalid path `%1%'")
-                % storePath);
 
         /* Write closure info to `fileName'. */
-        PathSet refs1,refs;
-        computeFSClosure(storePath, refs1);
-	for (PathSet::iterator j = refs1.begin(); j != refs1.end() ; j++) {
-		refs.insert (*j);
-		if (isDerivation (*j)) {
-			Derivation deriv = derivationFromPath (*j);
-			for (DerivationOutputs::iterator k=deriv.outputs.begin(); 
-			    k != deriv.outputs.end(); k++) {
-				refs.insert(k->second.path);
-				
-			}
-		}
-	}
-        /* !!! in secure Nix, the writing should be done on the
-           build uid for security (maybe). */
         writeStringToFile(tmpDir + "/" + fileName,
-            makeValidityRegistration(refs, false, false));
+            makeValidityRegistration(paths, false, false));
     }
 
     
@@ -2167,7 +2137,7 @@ SubstitutionGoal::SubstitutionGoal(const Path & storePath, Worker & worker)
 SubstitutionGoal::~SubstitutionGoal()
 {
     /* !!! Once we let substitution goals run under a build user, we
-       need to do use the setuid helper just as in ~DerivationGoal().
+       need to use the setuid helper just as in ~DerivationGoal().
        Idem for cancel. */
     if (pid != -1) worker.childTerminated(pid);
 }

tests/export-graph.nix

@@ -4,12 +4,13 @@ rec {
 
   printRefs =
     ''
+      echo $exportReferencesGraph
       while read path; do
           read drv
           read nrRefs
           echo "$path has $nrRefs references"
           echo "$path" >> $out
-          for ((n = 0; n < $nrRefs; n++)); do read ref; echo "ref $ref"; done
+          for ((n = 0; n < $nrRefs; n++)); do read ref; echo "ref $ref"; test -e "$ref"; done
       done < refs
     '';
 
@@ -22,7 +23,7 @@ rec {
   buildGraph = mkDerivation {
     name = "dependencies";
     builder = builtins.toFile "build-graph-builder" "${printRefs}";
-    exportBuildReferencesGraph = ["refs" (import ./dependencies.nix).drvPath];
+    exportReferencesGraph = ["refs" (import ./dependencies.nix).drvPath];
   };
 
 }