Carry tree artifacts' self data through aggregating middlemen.

This CL is a followup to c868c47. It is
intended to fix #5296. The immediate
problem in that issue is that remote caching finds a tree artifact in an input
runfiles tree without metadata in the cache. The metadata isn't there because
the runfiles artifacts are now all behind a middleman action, and
ArtifactFunction didn't propagate tree artifact values through middlemen. This
change fixes the problem by adding a tree artifact's self data value to the
values carried through to dependent actions.

Remote caching with tree artifact inputs seems to have been working mostly by
accident. (Evidence: it wasn't tested, and remote execution of actions with tree
artifact inputs results a Java traceback before and after
c868c47.) This CL is only really a bandaid to
return to the old "working" state. If remote execution wants to start supporting
tree artifacts properly in the future, we'll likely need to carry the tree
artifact child data through middleman actions, too.

Closes #5299.

Change-Id: I2e07d4fca0f6d2d34d97b7edb27f9d0063776225
PiperOrigin-RevId: 199079382

1 files changed, 5 insertions, 3 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/ArtifactFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/ArtifactFunction.java
index 199916674d..bee72a2321 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/ArtifactFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/ArtifactFunction.java
@@ -282,13 +282,15 @@ class ArtifactFunction implements SkyFunction {
       Artifact input = ArtifactSkyKey.artifact(entry.getKey());
       SkyValue inputValue = entry.getValue();
       Preconditions.checkNotNull(inputValue, "%s has null dep %s", artifact, input);
-      if (!(inputValue instanceof FileArtifactValue)) {
+      if (inputValue instanceof FileArtifactValue) {
+        inputs.add(Pair.of(input, (FileArtifactValue) inputValue));
+      } else if (inputValue instanceof TreeArtifactValue) {
+        inputs.add(Pair.of(input, ((TreeArtifactValue) inputValue).getSelfData()));
+      } else {
         // We do not recurse in aggregating middleman artifacts.
         Preconditions.checkState(!(inputValue instanceof AggregatingArtifactValue),
             "%s %s %s", artifact, action, inputValue);
-        continue;
       }
-      inputs.add(Pair.of(input, (FileArtifactValue) inputValue));
     }
     return (action.getActionType() == MiddlemanType.AGGREGATING_MIDDLEMAN)
         ? new AggregatingArtifactValue(inputs.build(), value)