Refactor DependencyResolver to collect and return loading errors.

This should never be triggered in production, where we always run a loading
phase first and only analyze targets that load successfully. I.e., this is
just plumbing which will be hooked up in a subsequent change.

--
MOS_MIGRATED_REVID=113258593

1 files changed, 3 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/PostConfiguredTargetFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/PostConfiguredTargetFunction.java
index 284491d996..878caeca08 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/PostConfiguredTargetFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/PostConfiguredTargetFunction.java
@@ -101,6 +101,9 @@ public class PostConfiguredTargetFunction implements SkyFunction {
           buildViewProvider.getSkyframeBuildView().getHostConfiguration(ct.getConfiguration());
       SkyframeDependencyResolver resolver =
           buildViewProvider.getSkyframeBuildView().createDependencyResolver(env);
+      // We don't track root causes here - this function is only invoked for successfully analyzed
+      // targets - as long as we redo the exact same steps here as in ConfiguredTargetFunction, this
+      // can never fail.
       deps =
           resolver.dependentNodeMap(
               ctgValue, hostConfiguration, /*aspect=*/ null, configConditions);