Provide a looser concept of BuildConfiguration "equality" to account

for dynamic configurations.

In short, as a configuration gets passed down its dependency tree it's
likely to lose fragments. For example, when a java_library depends on a cc_library,
the former has both JavaConfiguration and CppConfiguration while the latter
only has CppConfiguration.

It's still the "same" configuration in both cases, it's just that it got trimmed.

This cl provides a looser concept of BuildConfiguration equality that
accounts for this.

--
MOS_MIGRATED_REVID=107598262

3 files changed, 43 insertions, 2 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/BuildConfiguration.java b/src/main/java/com/google/devtools/build/lib/analysis/config/BuildConfiguration.java
index 49f71b605b..1ec1858d77 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/config/BuildConfiguration.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/config/BuildConfiguration.java
@@ -87,6 +87,7 @@ import java.util.LinkedHashSet;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Queue;
 import java.util.Set;
 import java.util.TreeMap;
@@ -946,6 +947,29 @@ public final class BuildConfiguration {
           outputDir.getRelative(BlazeDirectories.RELATIVE_INCLUDE_DIR));
       this.middlemanDirectory = Root.middlemanRoot(execRoot, outputDir);
     }
+
+    @Override
+    public boolean equals(Object o) {
+      if (o == this) {
+        return true;
+      }
+      if (!(o instanceof OutputRoots)) {
+        return false;
+      }
+      OutputRoots other = (OutputRoots) o;
+      return outputDirectory.equals(other.outputDirectory)
+          && binDirectory.equals(other.binDirectory)
+          && genfilesDirectory.equals(other.genfilesDirectory)
+          && coverageMetadataDirectory.equals(other.coverageMetadataDirectory)
+          && testLogsDirectory.equals(other.testLogsDirectory)
+          && includeDirectory.equals(other.includeDirectory);
+    }
+
+    @Override
+    public int hashCode() {
+      return Objects.hash(outputDirectory, binDirectory, genfilesDirectory,
+          coverageMetadataDirectory, testLogsDirectory, includeDirectory);
+    }
   }
 
   private final String checksum;
@@ -1061,6 +1085,22 @@ public final class BuildConfiguration {
   private final Map<String, OptionDetails> transitiveOptionsMap;
 
   /**
+   * Returns true if this configuration is semantically equal to the other, with
+   * the possible exception that the other has fewer fragments.
+   *
+   * <p>This is useful for dynamic configurations - as the same configuration gets "trimmed" while
+   * going down a dependency chain, it's still the same configuration but loses some of its
+   * fragments. So we need a more nuanced concept of "equality" than simple reference equality.
+   */
+  public boolean equalsOrIsSupersetOf(BuildConfiguration other) {
+    return this.equals(other)
+        || (outputRoots.equals(other.outputRoots)
+                && actionsEnabled == other.actionsEnabled
+                && fragments.values().containsAll(other.fragments.values())
+                && buildOptions.getOptions().containsAll(other.buildOptions.getOptions()));
+  }
+
+  /**
    * Returns map of all the fragments for this configuration.
    */
   public ImmutableMap<Class<? extends Fragment>, Fragment> getAllFragments() {
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/BuildOptions.java b/src/main/java/com/google/devtools/build/lib/analysis/config/BuildOptions.java
index f94b3eab46..c79d8b1612 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/config/BuildOptions.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/config/BuildOptions.java
@@ -32,6 +32,7 @@ import com.google.devtools.common.options.OptionsParsingException;
 
 import java.io.Serializable;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -219,7 +220,7 @@ public final class BuildOptions implements Cloneable, Serializable {
   /**
    * Returns the options contained in this collection.
    */
-  public Iterable<FragmentOptions> getOptions() {
+  public Collection<FragmentOptions> getOptions() {
     return fragmentOptionsMap.values();
   }
 
diff --git a/src/main/java/com/google/devtools/build/lib/rules/java/JavaLibraryHelper.java b/src/main/java/com/google/devtools/build/lib/rules/java/JavaLibraryHelper.java
index 9f6a639745..275a2d722d 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/java/JavaLibraryHelper.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/java/JavaLibraryHelper.java
@@ -189,7 +189,7 @@ public final class JavaLibraryHelper {
   public JavaLibraryHelper addDeps(Iterable<? extends TransitiveInfoCollection> deps) {
     for (TransitiveInfoCollection dep : deps) {
       Preconditions.checkArgument(dep.getConfiguration() == null
-          || dep.getConfiguration().equals(configuration));
+          || configuration.equalsOrIsSupersetOf(dep.getConfiguration()));
       this.deps.add(dep);
     }
     return this;