Simplify split transition semantics: noops now return the input build options.

This results in less special logic in the implementation and a simpler API.

PiperOrigin-RevId: 197772283

1 files changed, 9 insertions, 20 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/DependencyResolver.java b/src/main/java/com/google/devtools/build/lib/analysis/DependencyResolver.java
index dd34f19c09..a72b346cbc 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/DependencyResolver.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/DependencyResolver.java
@@ -403,8 +403,15 @@ public abstract class DependencyResolver {
 
       LateBoundDefault<?, ?> lateBoundDefault = attribute.getLateBoundDefault();
 
-      Collection<BuildOptions> splitOptions = getSplitOptions(attributeMap, attribute, ruleConfig);
-      if (!splitOptions.isEmpty() && !ruleConfig.isHostConfiguration()) {
+      boolean hasSplitTransition = false;
+      List<BuildOptions> splitOptions = null;
+      if (attribute.hasSplitConfigurationTransition()) {
+        splitOptions =
+            attribute.getSplitTransition(attributeMap).checkedSplit(ruleConfig.getOptions());
+        hasSplitTransition = !SplitTransition.equals(ruleConfig.getOptions(), splitOptions);
+      }
+
+      if (hasSplitTransition && !ruleConfig.isHostConfiguration()) {
         // Late-bound attribute with a split transition:
         // Since we want to get the same results as TransitionResolver.evaluateTransition (but
         // skip it since we've already applied the split), we want to make sure this logic
@@ -449,24 +456,6 @@ public abstract class DependencyResolver {
   }
 
   /**
-   * Returns the BuildOptions if the rule's attribute triggers a split in this configuration, or
-   * the empty collection if the attribute does not trigger a split transition or if the split
-   * transition does not apply.
-   *
-   * <p>Even though the attribute may have a split, splits don't have to apply in every
-   * configuration (see {@link SplitTransition#split}).
-   */
-  private static Collection<BuildOptions> getSplitOptions(ConfiguredAttributeMapper attributeMap,
-      Attribute attribute,
-      BuildConfiguration ruleConfig) {
-    if (!attribute.hasSplitConfigurationTransition()) {
-      return ImmutableList.<BuildOptions>of();
-    }
-    SplitTransition transition = attribute.getSplitTransition(attributeMap);
-    return transition.split(ruleConfig.getOptions());
-  }
-
-  /**
    * Returns the label dependencies for the given late-bound attribute in this rule.
    *
    * @param rule the rule being evaluated