Clean up DependencyResolver's interface for the dynamic config migration and for general readability.

Major changes:
 - Remove the intermediate Attribute -> LabelAndConfiguration multimap (computed in resolveAttributes). Instead, feed discovered values directly into the final Attribute -> Dependency map via a new RuleResolver interface.
 - Remove all references to LabelAndConfiguration. The configuration is always the owning rule's configuration except for two special cases: late-bound attributes with splits and late-bound attributes with LateBoundDefault.useHostConfiguration. The original interface made this very unclear and required a lot of awkward and sometimes incorrect logic. The new interface only involves configurations for the cases that actually need them.
 - Remove an ugly hack caused by BuildConfiguration.evaluateTransition mixing poorly with LateBoundDefault.useHostConfiguration (https://github.com/bazelbuild/bazel/blo[]e172693c27f3efc95ed163e43a9f0a7a6fb4017/src/main/java/com/google/devtools/build/lib/analysis/DependencyResolver.java#L488).
 - Remove a hack that applies split transitions twice because of BuildConfiguration.evaluateTransition mixing poorly with late-bound split attributes (https://github.com/bazelbuild/bazel/blo[]e172693c27f3efc95ed163e43a9f0a7a6fb4017/src/main/java/com/google/devtools/build/lib/analysis/DependencyResolver.java#L319). This happens to be innocent now but won't be when nested splits are possible.
- Solidifies the API contract for Attribute.LateBoundDefault.useHostConfiguration.
- Applies clearer naming and more consistent ordering to method parameters.
- Better documentation.

This is all also prep work for dynamic split transitions.

tl;dr: late-bound attributes are legitimately special. Treat them that way to make the rest of DependencyResolver cleaner and hack-free.

--
MOS_MIGRATED_REVID=128582618

1 files changed, 2 insertions, 4 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetFunction.java
index b0a8137c57..18fbe8ce74 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetFunction.java
@@ -710,14 +710,12 @@ final class ConfiguredTargetFunction implements SkyFunction {
     Map<Label, ConfigMatchingProvider> configConditions = new LinkedHashMap<>();
 
     // Collect the labels of the configured targets we need to resolve.
-    ListMultimap<Attribute, LabelAndConfiguration> configLabelMap = ArrayListMultimap.create();
+    ListMultimap<Attribute, Label> configLabelMap = ArrayListMultimap.create();
     RawAttributeMapper attributeMap = RawAttributeMapper.of(((Rule) target));
     for (Attribute a : ((Rule) target).getAttributes()) {
       for (Label configLabel : attributeMap.getConfigurabilityKeys(a.getName(), a.getType())) {
         if (!BuildType.Selector.isReservedLabel(configLabel)) {
-          configLabelMap.put(a, LabelAndConfiguration.of(
-              target.getLabel().resolveRepositoryRelative(configLabel),
-              ctgValue.getConfiguration()));
+          configLabelMap.put(a, target.getLabel().resolveRepositoryRelative(configLabel));
         }
       }
     }