Replace Attribute.Transition with config.transitions.Transition.

PiperOrigin-RevId: 179936355

23 files changed, 78 insertions, 61 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/BUILD b/src/main/java/com/google/devtools/build/lib/BUILD
index 6418d6d012..5ebf3384f5 100644
--- a/src/main/java/com/google/devtools/build/lib/BUILD
+++ b/src/main/java/com/google/devtools/build/lib/BUILD
@@ -293,6 +293,26 @@ java_library(
     ],
 )
 
+# Provides core configuration transition abstractions and Blaze-common (i.e not
+# rule-specific) transitions.
+java_library(
+    name = "config-transitions",
+    srcs = glob([
+        "analysis/config/transitions/*.java",
+    ]) + [
+        "analysis/config/BuildOptions.java",
+        "analysis/config/FragmentOptions.java",
+    ],
+    deps = [
+        "//src/main/java/com/google/devtools/build/lib/cmdline",
+        "//src/main/java/com/google/devtools/build/lib/concurrent",
+        "//src/main/java/com/google/devtools/common/options",
+        "//src/main/java/com/google/devtools/common/options:invocation_policy",
+        "//src/main/protobuf:invocation_policy_java_proto",
+        "//third_party:guava",
+    ],
+)
+
 java_library(
     name = "syntax",
     srcs = glob([
@@ -348,6 +368,7 @@ java_library(
     ],
     deps = [
         "//src/main/java/com/google/devtools/build/lib:config-matching-provider",
+        "//src/main/java/com/google/devtools/build/lib:config-transitions",
         "//src/main/java/com/google/devtools/build/lib:events",
         "//src/main/java/com/google/devtools/build/lib:skylarkinterface",
         "//src/main/java/com/google/devtools/build/lib:syntax",
@@ -424,6 +445,7 @@ java_library(
             "analysis/actions/*.java",
             "analysis/buildinfo/*.java",
             "analysis/config/*.java",
+            "analysis/config/transitions/*.java",
             "analysis/configuredtargets/*.java",
             "analysis/constraints/*.java",
             "analysis/extra/*.java",
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/BaseRuleClasses.java b/src/main/java/com/google/devtools/build/lib/analysis/BaseRuleClasses.java
index d8ec317c07..35ed29b55b 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/BaseRuleClasses.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/BaseRuleClasses.java
@@ -35,12 +35,12 @@ import com.google.devtools.build.lib.analysis.config.DynamicTransitionMapper;
 import com.google.devtools.build.lib.analysis.config.HostTransition;
 import com.google.devtools.build.lib.analysis.config.PatchTransition;
 import com.google.devtools.build.lib.analysis.config.RunUnder;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import com.google.devtools.build.lib.analysis.constraints.EnvironmentRule;
 import com.google.devtools.build.lib.analysis.test.TestConfiguration;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.packages.Attribute;
 import com.google.devtools.build.lib.packages.Attribute.LateBoundDefault;
-import com.google.devtools.build.lib.packages.Attribute.Transition;
 import com.google.devtools.build.lib.packages.AttributeMap;
 import com.google.devtools.build.lib.packages.RuleClass;
 import com.google.devtools.build.lib.packages.RuleClass.Builder;
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java b/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java
index 816dba9d43..222a250b4e 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java
@@ -45,6 +45,7 @@ import com.google.devtools.build.lib.analysis.config.ConfigMatchingProvider;
 import com.google.devtools.build.lib.analysis.config.ConfigurationResolver;
 import com.google.devtools.build.lib.analysis.config.InvalidConfigurationException;
 import com.google.devtools.build.lib.analysis.config.PatchTransition;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import com.google.devtools.build.lib.analysis.constraints.TopLevelConstraintSemantics;
 import com.google.devtools.build.lib.analysis.test.CoverageReportActionFactory;
 import com.google.devtools.build.lib.analysis.test.CoverageReportActionFactory.CoverageReportActionsWrapper;
@@ -62,7 +63,6 @@ import com.google.devtools.build.lib.packages.AspectDescriptor;
 import com.google.devtools.build.lib.packages.AspectParameters;
 import com.google.devtools.build.lib.packages.Attribute;
 import com.google.devtools.build.lib.packages.Attribute.ConfigurationTransition;
-import com.google.devtools.build.lib.packages.Attribute.Transition;
 import com.google.devtools.build.lib.packages.BuildType;
 import com.google.devtools.build.lib.packages.NativeAspectClass;
 import com.google.devtools.build.lib.packages.NoSuchPackageException;
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredRuleClassProvider.java b/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredRuleClassProvider.java
index 2c0bd9e0f6..beb12bfa35 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredRuleClassProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredRuleClassProvider.java
@@ -34,6 +34,7 @@ import com.google.devtools.build.lib.analysis.config.ConfigurationFragmentFactor
 import com.google.devtools.build.lib.analysis.config.DefaultsPackage;
 import com.google.devtools.build.lib.analysis.config.DynamicTransitionMapper;
 import com.google.devtools.build.lib.analysis.config.FragmentOptions;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import com.google.devtools.build.lib.analysis.skylark.SkylarkModules;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.cmdline.LabelSyntaxException;
@@ -213,7 +214,7 @@ public class ConfiguredRuleClassProvider implements RuleClassProvider {
     private final Map<Class<? extends RuleDefinition>, RuleClass> ruleMap = new HashMap<>();
     private final Digraph<Class<? extends RuleDefinition>> dependencyGraph =
         new Digraph<>();
-    private ImmutableMap.Builder<Attribute.Transition, Attribute.Transition> dynamicTransitionMaps
+    private ImmutableMap.Builder<Transition, Transition> dynamicTransitionMaps
         = ImmutableMap.builder();
     private Class<? extends BuildConfiguration.Fragment> universalFragment;
     private PrerequisiteValidator prerequisiteValidator;
@@ -330,7 +331,7 @@ public class ConfiguredRuleClassProvider implements RuleClassProvider {
       return this;
     }
 
-    public Builder addDynamicTransitionMaps(Map<Attribute.Transition, Attribute.Transition> maps) {
+    public Builder addDynamicTransitionMaps(Map<Transition, Transition> maps) {
       dynamicTransitionMaps.putAll(maps);
       return this;
     }
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/Dependency.java b/src/main/java/com/google/devtools/build/lib/analysis/Dependency.java
index a1e974b75b..318d4f5c4a 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/Dependency.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/Dependency.java
@@ -16,9 +16,9 @@ package com.google.devtools.build.lib.analysis;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableMap;
 import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.packages.AspectDescriptor;
-import com.google.devtools.build.lib.packages.Attribute;
 import java.util.Map;
 import java.util.Objects;
 import javax.annotation.Nullable;
@@ -103,7 +103,7 @@ public abstract class Dependency {
    * Creates a new {@link Dependency} with the given transition and aspects.
    */
   public static Dependency withTransitionAndAspects(
-      Label label, Attribute.Transition transition, AspectCollection aspects) {
+      Label label, Transition transition, AspectCollection aspects) {
     return new ConfigurationTransitionDependency(label, transition, aspects);
   }
 
@@ -141,7 +141,7 @@ public abstract class Dependency {
    *
    * @throws IllegalStateException if {@link #hasExplicitConfiguration} returns true.
    */
-  public abstract Attribute.Transition getTransition();
+  public abstract Transition getTransition();
 
   /**
    * Returns the set of aspects which should be evaluated and combined with the configured target
@@ -179,7 +179,7 @@ public abstract class Dependency {
     }
 
     @Override
-    public Attribute.Transition getTransition() {
+    public Transition getTransition() {
       throw new IllegalStateException(
           "This dependency has an explicit configuration, not a transition.");
     }
@@ -243,7 +243,7 @@ public abstract class Dependency {
     }
 
     @Override
-    public Attribute.Transition getTransition() {
+    public Transition getTransition() {
       throw new IllegalStateException(
           "This dependency has an explicit configuration, not a transition.");
     }
@@ -287,11 +287,11 @@ public abstract class Dependency {
    * Implementation of a dependency with a given configuration transition.
    */
   private static final class ConfigurationTransitionDependency extends Dependency {
-    private final Attribute.Transition transition;
+    private final Transition transition;
     private final AspectCollection aspects;
 
     public ConfigurationTransitionDependency(
-        Label label, Attribute.Transition transition, AspectCollection aspects) {
+        Label label, Transition transition, AspectCollection aspects) {
       super(label);
       this.transition = Preconditions.checkNotNull(transition);
       this.aspects = Preconditions.checkNotNull(aspects);
@@ -309,7 +309,7 @@ public abstract class Dependency {
     }
 
     @Override
-    public Attribute.Transition getTransition() {
+    public Transition getTransition() {
       return transition;
     }
 
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 8fbdf4bf32..7b9d60d175 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
@@ -27,6 +27,7 @@ import com.google.devtools.build.lib.analysis.config.HostTransition;
 import com.google.devtools.build.lib.analysis.config.InvalidConfigurationException;
 import com.google.devtools.build.lib.analysis.config.PatchTransition;
 import com.google.devtools.build.lib.analysis.config.TransitionResolver;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
 import com.google.devtools.build.lib.events.Location;
@@ -723,7 +724,7 @@ public abstract class DependencyResolver {
       if (toTarget == null) {
         return; // Skip this round: we still need to Skyframe-evaluate the dep's target.
       }
-      Attribute.Transition transition = transitionResolver.evaluateTransition(
+      Transition transition = transitionResolver.evaluateTransition(
           ruleConfig, rule, attributeAndOwner.attribute, toTarget, attributeMap);
       outgoingEdges.put(
           attributeAndOwner.attribute,
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java b/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java
index 4462ae4bee..6abf4912a1 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java
@@ -47,6 +47,7 @@ import com.google.devtools.build.lib.analysis.config.BuildOptions;
 import com.google.devtools.build.lib.analysis.config.ConfigMatchingProvider;
 import com.google.devtools.build.lib.analysis.config.FragmentCollection;
 import com.google.devtools.build.lib.analysis.config.PatchTransition;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import com.google.devtools.build.lib.analysis.configuredtargets.RuleConfiguredTarget.Mode;
 import com.google.devtools.build.lib.analysis.fileset.FilesetProvider;
 import com.google.devtools.build.lib.analysis.platform.PlatformInfo;
@@ -389,13 +390,13 @@ public final class RuleContext extends TargetContext
    * Returns a configuration fragment for this this target.
    */
   @Nullable
-  public <T extends Fragment> T getFragment(Class<T> fragment, Attribute.Transition transition) {
+  public <T extends Fragment> T getFragment(Class<T> fragment, Transition transition) {
     return getFragment(fragment, fragment.getSimpleName(), "", transition);
   }
 
   @Nullable
   protected <T extends Fragment> T getFragment(Class<T> fragment, String name,
-      String additionalErrorMessage, Attribute.Transition transition) {
+      String additionalErrorMessage, Transition transition) {
     // TODO(bazel-team): The fragments can also be accessed directly through BuildConfiguration.
     // Can we lock that down somehow?
     Preconditions.checkArgument(isLegalFragment(fragment, transition),
@@ -413,7 +414,7 @@ public final class RuleContext extends TargetContext
   }
 
   @Nullable
-  public Fragment getSkylarkFragment(String name, Attribute.Transition transition) {
+  public Fragment getSkylarkFragment(String name, Transition transition) {
     Class<? extends Fragment> fragmentClass =
         getConfiguration(transition).getSkylarkFragmentByName(name);
     if (fragmentClass == null) {
@@ -427,12 +428,12 @@ public final class RuleContext extends TargetContext
         transition);
   }
 
-  public ImmutableCollection<String> getSkylarkFragmentNames(Attribute.Transition transition) {
+  public ImmutableCollection<String> getSkylarkFragmentNames(Transition transition) {
     return getConfiguration(transition).getSkylarkFragmentNames();
   }
 
   public <T extends Fragment> boolean isLegalFragment(
-      Class<T> fragment, Attribute.Transition transition) {
+      Class<T> fragment, Transition transition) {
     return fragment == universalFragment
         || fragment == PlatformConfiguration.class
         || configurationFragmentPolicy.isLegalConfigurationFragment(fragment, transition);
@@ -443,7 +444,7 @@ public final class RuleContext extends TargetContext
     return isLegalFragment(fragment, ConfigurationTransition.NONE);
   }
 
-  protected BuildConfiguration getConfiguration(Attribute.Transition transition) {
+  protected BuildConfiguration getConfiguration(Transition transition) {
     return transition.isHostTransition() ? hostConfiguration : getConfiguration();
   }
 
@@ -1056,7 +1057,7 @@ public final class RuleContext extends TargetContext
       throw new IllegalStateException(getRuleClassNameForLogging() + " attribute " + attributeName
         + " is not a label type attribute");
     }
-    Attribute.Transition transition = attributeDefinition.getConfigurationTransition();
+    Transition transition = attributeDefinition.getConfigurationTransition();
     if (mode == Mode.HOST) {
       if (!(transition instanceof PatchTransition)) {
         throw new IllegalStateException(getRule().getLocation() + ": "
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/ComposingRuleTransitionFactory.java b/src/main/java/com/google/devtools/build/lib/analysis/config/ComposingRuleTransitionFactory.java
index d8e1c55332..a6a54a28a6 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/config/ComposingRuleTransitionFactory.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/config/ComposingRuleTransitionFactory.java
@@ -15,7 +15,7 @@
 
 package com.google.devtools.build.lib.analysis.config;
 
-import com.google.devtools.build.lib.packages.Attribute;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import com.google.devtools.build.lib.packages.Rule;
 import com.google.devtools.build.lib.packages.RuleTransitionFactory;
 
@@ -37,7 +37,7 @@ public class ComposingRuleTransitionFactory implements RuleTransitionFactory {
   }
 
   @Override
-  public Attribute.Transition buildTransitionFor(Rule rule) {
+  public Transition buildTransitionFor(Rule rule) {
     PatchTransition transition1 = (PatchTransition) rtf1.buildTransitionFor(rule);
     PatchTransition transition2 = (PatchTransition) rtf2.buildTransitionFor(rule);
 
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/ComposingSplitTransition.java b/src/main/java/com/google/devtools/build/lib/analysis/config/ComposingSplitTransition.java
index 3241edccff..b984ee4d55 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/config/ComposingSplitTransition.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/config/ComposingSplitTransition.java
@@ -16,9 +16,9 @@ package com.google.devtools.build.lib.analysis.config;
 
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import com.google.devtools.build.lib.packages.Attribute.ConfigurationTransition;
 import com.google.devtools.build.lib.packages.Attribute.SplitTransition;
-import com.google.devtools.build.lib.packages.Attribute.Transition;
 import java.util.List;
 
 /**
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 c23d7a8b74..9a16f0b2db 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
@@ -26,6 +26,7 @@ import com.google.common.collect.Multimap;
 import com.google.common.collect.Sets;
 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.Transition;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.concurrent.ThreadSafety;
 import com.google.devtools.build.lib.events.Event;
@@ -179,7 +180,7 @@ public final class ConfigurationResolver {
       }
 
       boolean sameFragments = depFragments.equals(ctgFragments);
-      Attribute.Transition transition = dep.getTransition();
+      Transition transition = dep.getTransition();
 
       if (sameFragments) {
         if (transition == Attribute.ConfigurationTransition.NONE) {
@@ -291,11 +292,11 @@ public final class ConfigurationResolver {
     // Treat this as immutable. The only reason this isn't an ImmutableSet is because it
     // gets bound to a NestedSet.toSet() reference, which returns a Set interface.
     final Set<Class<? extends BuildConfiguration.Fragment>> fragments;
-    final Attribute.Transition transition;
+    final Transition transition;
     private final int hashCode;
 
     FragmentsAndTransition(Set<Class<? extends BuildConfiguration.Fragment>> fragments,
-        Attribute.Transition transition) {
+        Transition transition) {
       this.fragments = fragments;
       this.transition = transition;
       hashCode = Objects.hash(this.fragments, this.transition);
@@ -407,7 +408,7 @@ public final class ConfigurationResolver {
    */
   @VisibleForTesting
   public static List<BuildOptions> applyTransition(BuildOptions fromOptions,
-      Attribute.Transition transition,
+      Transition transition,
       Iterable<Class<? extends BuildConfiguration.Fragment>> requiredFragments,
       RuleClassProvider ruleClassProvider, boolean trimResults) {
     List<BuildOptions> result;
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/DynamicTransitionMapper.java b/src/main/java/com/google/devtools/build/lib/analysis/config/DynamicTransitionMapper.java
index 5166cb677c..0ccb19a40a 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/config/DynamicTransitionMapper.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/config/DynamicTransitionMapper.java
@@ -14,8 +14,8 @@
 package com.google.devtools.build.lib.analysis.config;
 
 import com.google.common.collect.ImmutableMap;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import com.google.devtools.build.lib.packages.Attribute;
-import com.google.devtools.build.lib.packages.Attribute.Transition;
 import com.google.devtools.build.lib.packages.RuleClass;
 
 /**
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/FragmentCollection.java b/src/main/java/com/google/devtools/build/lib/analysis/config/FragmentCollection.java
index cdadf22a85..d0a779c1c7 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/config/FragmentCollection.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/config/FragmentCollection.java
@@ -16,12 +16,11 @@ package com.google.devtools.build.lib.analysis.config;
 import com.google.common.base.Joiner;
 import com.google.common.collect.ImmutableCollection;
 import com.google.devtools.build.lib.analysis.RuleContext;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
-import com.google.devtools.build.lib.packages.Attribute;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.syntax.ClassObject;
-
 import javax.annotation.Nullable;
 
 /**
@@ -40,9 +39,9 @@ import javax.annotation.Nullable;
     + "(see <a href=\"../rules.md#fragments\">here</a>).")
 public class FragmentCollection implements ClassObject {
   private final RuleContext ruleContext;
-  private final Attribute.Transition transition;
+  private final Transition transition;
 
-  public FragmentCollection(RuleContext ruleContext, Attribute.Transition transition) {
+  public FragmentCollection(RuleContext ruleContext, Transition transition) {
     this.ruleContext = ruleContext;
     this.transition = transition;
   }
@@ -71,7 +70,7 @@ public class FragmentCollection implements ClassObject {
     return String.format("'%s'", Joiner.on("', '").join(getKeys()));
   }
 
-  public static String getConfigurationName(Attribute.Transition config) {
+  public static String getConfigurationName(Transition config) {
     return config.isHostTransition() ? "host" : "target";
   }
 
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/PatchTransition.java b/src/main/java/com/google/devtools/build/lib/analysis/config/PatchTransition.java
index 80091e05b9..fea95bac6a 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/config/PatchTransition.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/config/PatchTransition.java
@@ -13,7 +13,7 @@
 // limitations under the License.
 package com.google.devtools.build.lib.analysis.config;
 
-import com.google.devtools.build.lib.packages.Attribute;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 
 /**
  * Interface for a configuration transition.
@@ -48,7 +48,7 @@ import com.google.devtools.build.lib.packages.Attribute;
  * {@link com.google.devtools.build.lib.analysis.config.BuildOptions} doesn't currently
  * enforce immutability. So care must be taken not to modify the wrong instance.
  */
-public interface PatchTransition extends Attribute.Transition {
+public interface PatchTransition extends Transition {
 
   /**
    * Applies the transition.
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/TransitionResolver.java b/src/main/java/com/google/devtools/build/lib/analysis/config/TransitionResolver.java
index e9c4b9bd7d..b84c5dbfbd 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/config/TransitionResolver.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/config/TransitionResolver.java
@@ -17,10 +17,10 @@ package com.google.devtools.build.lib.analysis.config;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
 import com.google.devtools.build.lib.analysis.TargetAndConfiguration;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import com.google.devtools.build.lib.packages.Attribute;
 import com.google.devtools.build.lib.packages.Attribute.ConfigurationTransition;
 import com.google.devtools.build.lib.packages.Attribute.SplitTransition;
-import com.google.devtools.build.lib.packages.Attribute.Transition;
 import com.google.devtools.build.lib.packages.ConfiguredAttributeMapper;
 import com.google.devtools.build.lib.packages.InputFile;
 import com.google.devtools.build.lib.packages.PackageGroup;
@@ -29,7 +29,7 @@ import com.google.devtools.build.lib.packages.RuleTransitionFactory;
 import com.google.devtools.build.lib.packages.Target;
 
 /**
- * Tool for evaluating which {@link Attribute.Transition}(s) should be applied to given targets.
+ * Tool for evaluating which {@link Transition}(s) should be applied to given targets.
  *
  * <p>For the work of turning these transitions into actual configurations, see {@link
  * ConfigurationResolver}.
@@ -130,7 +130,7 @@ public final class TransitionResolver {
    * Same as evaluateTransition except does not check for transitions coming from parents and
    * enables support for rule-triggered top-level configuration hooks.
    */
-  public static Attribute.Transition evaluateTopLevelTransition(
+  public static Transition evaluateTopLevelTransition(
       TargetAndConfiguration targetAndConfig, DynamicTransitionMapper dynamicTransitionMapper) {
     Target target = targetAndConfig.getTarget();
     BuildConfiguration fromConfig = targetAndConfig.getConfiguration();
diff --git a/src/main/java/com/google/devtools/build/lib/packages/AspectDefinition.java b/src/main/java/com/google/devtools/build/lib/packages/AspectDefinition.java
index 773001e004..da5dcc5fe9 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/AspectDefinition.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/AspectDefinition.java
@@ -22,9 +22,9 @@ import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.LinkedHashMultimap;
 import com.google.common.collect.Multimap;
 import com.google.common.collect.SetMultimap;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
-import com.google.devtools.build.lib.packages.Attribute.Transition;
 import com.google.devtools.build.lib.packages.ConfigurationFragmentPolicy.MissingFragmentPolicy;
 import com.google.devtools.build.lib.syntax.Type;
 import com.google.devtools.build.lib.syntax.Type.LabelClass;
diff --git a/src/main/java/com/google/devtools/build/lib/packages/Attribute.java b/src/main/java/com/google/devtools/build/lib/packages/Attribute.java
index 3f68f6beb0..b736613863 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/Attribute.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/Attribute.java
@@ -29,6 +29,7 @@ import com.google.common.collect.Iterables;
 import com.google.common.collect.Ordering;
 import com.google.common.collect.Sets;
 import com.google.devtools.build.lib.analysis.TransitiveInfoProvider;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import com.google.devtools.build.lib.concurrent.ThreadSafety;
 import com.google.devtools.build.lib.events.EventHandler;
 import com.google.devtools.build.lib.events.Location;
@@ -147,18 +148,6 @@ public final class Attribute implements Comparable<Attribute> {
   }
 
   /**
-   * A configuration transition.
-   */
-  public interface Transition {
-    /**
-     * Does this transition switch to a "host" configuration?
-     */
-    default boolean isHostTransition() {
-      return false;
-    }
-  }
-
-  /**
    * A configuration split transition; this should be used to transition to multiple configurations
    * simultaneously. Note that the corresponding rule implementations must have special support to
    * handle this.
diff --git a/src/main/java/com/google/devtools/build/lib/packages/ConfigurationFragmentPolicy.java b/src/main/java/com/google/devtools/build/lib/packages/ConfigurationFragmentPolicy.java
index ee44b6427b..fdc6061a99 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/ConfigurationFragmentPolicy.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/ConfigurationFragmentPolicy.java
@@ -18,8 +18,8 @@ import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.ImmutableSetMultimap;
 import com.google.common.collect.LinkedHashMultimap;
 import com.google.common.collect.SetMultimap;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import com.google.devtools.build.lib.packages.Attribute.ConfigurationTransition;
-import com.google.devtools.build.lib.packages.Attribute.Transition;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
 import java.util.Collection;
 import java.util.Set;
@@ -93,7 +93,7 @@ public final class ConfigurationFragmentPolicy {
      *
      * <p>The value is inherited by subclasses.
      */
-    public Builder requiresConfigurationFragments(Attribute.Transition transition,
+    public Builder requiresConfigurationFragments(Transition transition,
         Collection<Class<?>> configurationFragments) {
       // We can relax this assumption if needed. But it's already sketchy to let a rule see more
       // than its own configuration. So we don't want to casually proliferate this pattern.
diff --git a/src/main/java/com/google/devtools/build/lib/packages/RuleClass.java b/src/main/java/com/google/devtools/build/lib/packages/RuleClass.java
index e76339dc7b..a12c08f9c2 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/RuleClass.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/RuleClass.java
@@ -30,6 +30,7 @@ import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Ordering;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.cmdline.LabelSyntaxException;
 import com.google.devtools.build.lib.cmdline.PackageIdentifier;
@@ -38,7 +39,6 @@ import com.google.devtools.build.lib.events.Location;
 import com.google.devtools.build.lib.events.NullEventHandler;
 import com.google.devtools.build.lib.packages.Attribute.SkylarkComputedDefaultTemplate;
 import com.google.devtools.build.lib.packages.Attribute.SkylarkComputedDefaultTemplate.CannotPrecomputeDefaultsException;
-import com.google.devtools.build.lib.packages.Attribute.Transition;
 import com.google.devtools.build.lib.packages.BuildType.SelectorList;
 import com.google.devtools.build.lib.packages.ConfigurationFragmentPolicy.MissingFragmentPolicy;
 import com.google.devtools.build.lib.packages.RuleFactory.AttributeValues;
diff --git a/src/main/java/com/google/devtools/build/lib/packages/RuleTransitionFactory.java b/src/main/java/com/google/devtools/build/lib/packages/RuleTransitionFactory.java
index 215461fa3d..94613ab5dc 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/RuleTransitionFactory.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/RuleTransitionFactory.java
@@ -14,7 +14,7 @@
 
 package com.google.devtools.build.lib.packages;
 
-import com.google.devtools.build.lib.packages.Attribute.Transition;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import javax.annotation.Nullable;
 
 /**
diff --git a/src/main/java/com/google/devtools/build/lib/packages/SkylarkDefinedAspect.java b/src/main/java/com/google/devtools/build/lib/packages/SkylarkDefinedAspect.java
index 15851545ad..3391ccc9f4 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/SkylarkDefinedAspect.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/SkylarkDefinedAspect.java
@@ -18,6 +18,7 @@ import com.google.common.base.Function;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.events.Location;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkPrinter;
@@ -37,7 +38,7 @@ public class SkylarkDefinedAspect implements SkylarkExportable, SkylarkAspect {
   private final ImmutableSet<SkylarkProviderIdentifier> provides;
   private final ImmutableSet<String> paramAttributes;
   private final ImmutableSet<String> fragments;
-  private final Attribute.Transition hostTransition;
+  private final Transition hostTransition;
   private final ImmutableSet<String> hostFragments;
   private final ImmutableList<Label> requiredToolchains;
 
@@ -53,7 +54,7 @@ public class SkylarkDefinedAspect implements SkylarkExportable, SkylarkAspect {
       ImmutableSet<String> paramAttributes,
       ImmutableSet<String> fragments,
       // The host transition is in lib.analysis, so we can't reference it directly here.
-      Attribute.Transition hostTransition,
+      Transition hostTransition,
       ImmutableSet<String> hostFragments,
       ImmutableList<Label> requiredToolchains,
       Environment funcallEnv) {
diff --git a/src/main/java/com/google/devtools/build/lib/rules/android/AndroidRuleClasses.java b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidRuleClasses.java
index f57d4891eb..6a8a0a9eb2 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/android/AndroidRuleClasses.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidRuleClasses.java
@@ -37,6 +37,7 @@ import com.google.devtools.build.lib.analysis.RuleDefinitionEnvironment;
 import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
 import com.google.devtools.build.lib.analysis.config.BuildOptions;
 import com.google.devtools.build.lib.analysis.config.HostTransition;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.events.EventHandler;
 import com.google.devtools.build.lib.packages.Attribute;
@@ -301,7 +302,7 @@ public final class AndroidRuleClasses {
             ImmutableSet.of("android_binary", "android_library");
 
         @Override
-        public Attribute.Transition buildTransitionFor(Rule depRule) {
+        public Transition buildTransitionFor(Rule depRule) {
           return keepFilterRuleClasses.contains(depRule.getRuleClass())
               ? null
               : ResourceFilterFactory.REMOVE_DYNAMICALLY_CONFIGURED_RESOURCE_FILTERING_TRANSITION;
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppRuleClasses.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppRuleClasses.java
index af37c28c56..90cca62ef2 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppRuleClasses.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppRuleClasses.java
@@ -34,11 +34,11 @@ import com.google.common.collect.ImmutableMap;
 import com.google.devtools.build.lib.analysis.LanguageDependentFragment.LibraryLanguage;
 import com.google.devtools.build.lib.analysis.RuleDefinitionEnvironment;
 import com.google.devtools.build.lib.analysis.config.PatchTransition;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import com.google.devtools.build.lib.analysis.test.InstrumentedFilesCollector.InstrumentationSpec;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.packages.Attribute;
 import com.google.devtools.build.lib.packages.Attribute.LateBoundDefault;
-import com.google.devtools.build.lib.packages.Attribute.Transition;
 import com.google.devtools.build.lib.packages.ImplicitOutputsFunction.SafeImplicitOutputsFunction;
 import com.google.devtools.build.lib.packages.RuleTransitionFactory;
 import com.google.devtools.build.lib.rules.cpp.transitions.DisableLipoTransition;
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutor.java b/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutor.java
index 6e5bb27b1a..c2295c4b60 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutor.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutor.java
@@ -73,6 +73,7 @@ import com.google.devtools.build.lib.analysis.config.ConfigurationResolver;
 import com.google.devtools.build.lib.analysis.config.HostTransition;
 import com.google.devtools.build.lib.analysis.config.InvalidConfigurationException;
 import com.google.devtools.build.lib.analysis.config.PatchTransition;
+import com.google.devtools.build.lib.analysis.config.transitions.Transition;
 import com.google.devtools.build.lib.analysis.configuredtargets.MergedConfiguredTarget;
 import com.google.devtools.build.lib.analysis.configuredtargets.MergedConfiguredTarget.DuplicateException;
 import com.google.devtools.build.lib.cmdline.Label;
@@ -1120,7 +1121,7 @@ public abstract class SkyframeExecutor implements WalkableGraphFactory {
     // The host configuration inherits the data, not target options. This is so host tools don't
     // apply LIPO.
     BuildConfiguration firstTargetConfig = topLevelTargetConfigs.get(0);
-    Attribute.Transition dataTransition =
+    Transition dataTransition =
         ((ConfiguredRuleClassProvider) ruleClassProvider)
             .getDynamicTransitionMapper()
             .map(Attribute.ConfigurationTransition.DATA);
@@ -1604,7 +1605,7 @@ public abstract class SkyframeExecutor implements WalkableGraphFactory {
       ExtendedEventHandler eventHandler,
       Label label,
       BuildConfiguration configuration,
-      Attribute.Transition transition) {
+      Transition transition) {
     return Iterables.getFirst(
         getConfiguredTargets(
             eventHandler,