Roll forward execroot change

RELNOTES[INC]: Previously, an external repository would be symlinked into the
execution root at execroot/local_repo/external/remote_repo. This changes it to
be at execroot/remote_repo. This may break genrules/Skylark actions that
hardcode execution root paths. If this causes breakages for you, ensure that
genrules are using $(location :target) to access files and Skylark rules are
using http://bazel.io/docs/skylark/lib/File.html's path, dirname, etc.
functions. Custom crosstools that hardcode external/<repo> paths will have to
be updated.

Issue #1262.

--
PiperOrigin-RevId: 147726370
MOS_MIGRATED_REVID=147726370

1 files changed, 4 insertions, 3 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/genrule/GenRuleBase.java b/src/main/java/com/google/devtools/build/lib/rules/genrule/GenRuleBase.java
index a81a38ff1b..e4cf0da886 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/genrule/GenRuleBase.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/genrule/GenRuleBase.java
@@ -34,6 +34,7 @@ import com.google.devtools.build.lib.analysis.Runfiles;
 import com.google.devtools.build.lib.analysis.RunfilesProvider;
 import com.google.devtools.build.lib.analysis.TransitiveInfoCollection;
 import com.google.devtools.build.lib.cmdline.Label;
+import com.google.devtools.build.lib.cmdline.PackageIdentifier;
 import com.google.devtools.build.lib.collect.nestedset.NestedSet;
 import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
 import com.google.devtools.build.lib.collect.nestedset.Order;
@@ -336,9 +337,9 @@ public abstract class GenRuleBase implements RuleConfiguredTargetFactory {
           } else {
             dir = ruleContext.getConfiguration().getGenfilesFragment();
           }
-          PathFragment relPath =
-              ruleContext.getRule().getLabel().getPackageIdentifier().getSourceRoot();
-          return dir.getRelative(relPath).getPathString();
+          PackageIdentifier pkgId = ruleContext.getRule().getLabel().getPackageIdentifier();
+          return pkgId.getRepository().getPathUnderExecRoot().getRelative(dir)
+              .getRelative(pkgId.getPackageFragment()).getPathString();
         }
       } else if (JDK_MAKE_VARIABLE.matcher("$(" + name + ")").find()) {
         return new ConfigurationMakeVariableContext(