Unfork SplitTransition / PatchTransition invocations.

Part of https://docs.google.com/document/d/1_UJKmAQ9EE8i3Pl0il3YLTYr-Q9EKYYyLatt2zohfyM/edit#

PiperOrigin-RevId: 197890685

2 files changed, 7 insertions, 43 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/ConfigurationResolver.java b/src/main/java/com/google/devtools/build/lib/analysis/config/ConfigurationResolver.java
index f26ca9f920..03052fb972 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/config/ConfigurationResolver.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/config/ConfigurationResolver.java
@@ -28,8 +28,6 @@ import com.google.devtools.build.lib.analysis.Dependency;
 import com.google.devtools.build.lib.analysis.TargetAndConfiguration;
 import com.google.devtools.build.lib.analysis.config.transitions.ConfigurationTransition;
 import com.google.devtools.build.lib.analysis.config.transitions.NoTransition;
-import com.google.devtools.build.lib.analysis.config.transitions.PatchTransition;
-import com.google.devtools.build.lib.analysis.config.transitions.SplitTransition;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.concurrent.ThreadSafety;
 import com.google.devtools.build.lib.events.Event;
@@ -424,16 +422,9 @@ public final class ConfigurationResolver {
       ConfigurationTransition transition,
       Iterable<Class<? extends BuildConfiguration.Fragment>> requiredFragments,
       RuleClassProvider ruleClassProvider, boolean trimResults) {
-    List<BuildOptions> result;
-    if (transition instanceof PatchTransition) {
-      // TODO(bazel-team): safety-check that this never mutates fromOptions.
-      result = ImmutableList.of(((PatchTransition) transition).patch(fromOptions));
-    } else if (transition instanceof SplitTransition) {
-      return ((SplitTransition) transition).split(fromOptions);
-    } else {
-      throw new IllegalStateException(String.format(
-          "unsupported config transition type: %s", transition.getClass().getName()));
-    }
+
+    // TODO(bazel-team): safety-check that this never mutates fromOptions.
+    List<BuildOptions> result = transition.apply(fromOptions);
 
     if (!trimResults) {
       return result;
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/transitions/ComposingSplitTransition.java b/src/main/java/com/google/devtools/build/lib/analysis/config/transitions/ComposingSplitTransition.java
index 190b867329..4eb6ae0e89 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/config/transitions/ComposingSplitTransition.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/config/transitions/ComposingSplitTransition.java
@@ -14,7 +14,6 @@
 
 package com.google.devtools.build.lib.analysis.config.transitions;
 
-import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.devtools.build.lib.analysis.config.BuildOptions;
 import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
@@ -59,29 +58,19 @@ public class ComposingSplitTransition implements SplitTransition {
   @AutoCodec.Instantiator
   public ComposingSplitTransition(
       ConfigurationTransition transition1, ConfigurationTransition transition2) {
-    this.transition1 = verifySupported(transition1);
-    this.transition2 = verifySupported(transition2);
+    this.transition1 = transition1;
+    this.transition2 = transition2;
   }
 
   @Override
   public List<BuildOptions> split(BuildOptions buildOptions) {
     ImmutableList.Builder<BuildOptions> toOptions = ImmutableList.builder();
-    for (BuildOptions transition1Options : apply(buildOptions, transition1)) {
-      toOptions.addAll(apply(transition1Options, transition2));
+    for (BuildOptions transition1Options : transition1.apply(buildOptions)) {
+      toOptions.addAll(transition2.apply(transition1Options));
     }
     return toOptions.build();
   }
 
-  /**
-   * Verifies support for the given transition type. Throws an {@link IllegalArgumentException} if
-   * unsupported.
-   */
-  private ConfigurationTransition verifySupported(ConfigurationTransition transition) {
-    Preconditions.checkArgument(transition instanceof PatchTransition
-        || transition instanceof SplitTransition);
-    return transition;
-  }
-
   @Override
   public int hashCode() {
     return Objects.hash(transition1, transition2);
@@ -111,20 +100,4 @@ public class ComposingSplitTransition implements SplitTransition {
   public ComposingPatchTransition asPatch() {
     return new ComposingPatchTransition(this);
   }
-
-  /**
-   * Applies the given transition over the given {@link BuildOptions}, returns the result.
-   */
-  // TODO(gregce): move this somewhere more general. This isn't intrinsic to composed splits.
-  static List<BuildOptions> apply(BuildOptions fromOptions, ConfigurationTransition transition) {
-    if (transition instanceof PatchTransition) {
-      return ImmutableList.<BuildOptions>of(((PatchTransition) transition).patch(fromOptions));
-    } else if (transition instanceof SplitTransition) {
-      return ((SplitTransition) transition).split(fromOptions);
-    } else {
-      throw new IllegalStateException(
-          String.format("Unsupported composite transition type: %s",
-              transition.getClass().getName()));
-    }
-  }
 }