Make default method stubbing resilient to core library renaming, to preserve idempotency.

RELNOTES: None.

PiperOrigin-RevId: 204957400

3 files changed, 36 insertions, 29 deletions

diff --git a/src/tools/android/java/com/google/devtools/build/android/desugar/CoreLibrarySupport.java b/src/tools/android/java/com/google/devtools/build/android/desugar/CoreLibrarySupport.java
index f247074852..9dfd43af9d 100644
--- a/src/tools/android/java/com/google/devtools/build/android/desugar/CoreLibrarySupport.java
+++ b/src/tools/android/java/com/google/devtools/build/android/desugar/CoreLibrarySupport.java
@@ -43,6 +43,7 @@ import org.objectweb.asm.Label;
 import org.objectweb.asm.MethodVisitor;
 import org.objectweb.asm.Opcodes;
 import org.objectweb.asm.Type;
+import org.objectweb.asm.commons.Remapper;
 
 /**
  * Helper that keeps track of which core library classes and methods we want to rewrite.
@@ -62,6 +63,14 @@ class CoreLibrarySupport {
   /** Map from {@code owner#name} core library members to their new owners. */
   private final ImmutableMap<String, String> memberMoves;
 
+  /** ASM {@link Remapper} based on {@link #renamedPrefixes}. */
+  private final Remapper corePackageRemapper = new Remapper() {
+    @Override
+    public String map(String typeName) {
+      return isRenamedCoreLibrary(typeName) ? renameCoreLibrary(typeName) : typeName;
+    }
+  };
+
   /** For the collection of definitions of emulated default methods (deterministic iteration). */
   private final Multimap<String, EmulatedMethod> emulatedDefaultMethods =
       LinkedHashMultimap.create();
@@ -131,6 +140,10 @@ class CoreLibrarySupport {
         : internalName;
   }
 
+  public Remapper getRemapper() {
+    return corePackageRemapper;
+  }
+
   @Nullable
   public String getMoveTarget(String owner, String name) {
     return memberMoves.get(rewriter.unprefix(owner) + '#' + name);
diff --git a/src/tools/android/java/com/google/devtools/build/android/desugar/CorePackageRenamer.java b/src/tools/android/java/com/google/devtools/build/android/desugar/CorePackageRenamer.java
index 5f1dc2e0f6..050e4bfcc0 100644
--- a/src/tools/android/java/com/google/devtools/build/android/desugar/CorePackageRenamer.java
+++ b/src/tools/android/java/com/google/devtools/build/android/desugar/CorePackageRenamer.java
@@ -15,7 +15,6 @@ package com.google.devtools.build.android.desugar;
 
 import org.objectweb.asm.ClassVisitor;
 import org.objectweb.asm.commons.ClassRemapper;
-import org.objectweb.asm.commons.Remapper;
 
 /**
  * A visitor that renames packages so configured using {@link CoreLibrarySupport}..
@@ -23,23 +22,6 @@ import org.objectweb.asm.commons.Remapper;
 class CorePackageRenamer extends ClassRemapper {
 
   public CorePackageRenamer(ClassVisitor cv, CoreLibrarySupport support) {
-    super(cv, new CorePackageRemapper(support));
-  }
-
-  private static final class CorePackageRemapper extends Remapper {
-    private final CoreLibrarySupport support;
-
-    private CorePackageRemapper(CoreLibrarySupport support) {
-      this.support = support;
-    }
-
-    public boolean isRenamed(String owner) {
-      return support.isRenamedCoreLibrary(owner);
-    }
-
-    @Override
-    public String map(String typeName) {
-      return isRenamed(typeName) ? support.renameCoreLibrary(typeName) : typeName;
-    }
+    super(cv, support.getRemapper());
   }
 }
diff --git a/src/tools/android/java/com/google/devtools/build/android/desugar/DefaultMethodClassFixer.java b/src/tools/android/java/com/google/devtools/build/android/desugar/DefaultMethodClassFixer.java
index 1de48bf585..130c197f9a 100644
--- a/src/tools/android/java/com/google/devtools/build/android/desugar/DefaultMethodClassFixer.java
+++ b/src/tools/android/java/com/google/devtools/build/android/desugar/DefaultMethodClassFixer.java
@@ -302,14 +302,6 @@ public class DefaultMethodClassFixer extends ClassVisitor {
     }
   }
 
-  private void recordIfInstanceMethod(int access, String name, String desc) {
-    if (BitFlags.noneSet(access, Opcodes.ACC_STATIC)) {
-      // Record all declared instance methods, including abstract, bridge, and native methods, as
-      // they all take precedence over default methods.
-      instanceMethods.add(name + ":" + desc);
-    }
-  }
-
   /**
    * Starting from the given interfaces, this method scans the interface hierarchy, finds the
    * interfaces that have default methods and <clinit>, and returns the companion class names of
@@ -410,7 +402,7 @@ public class DefaultMethodClassFixer extends ClassVisitor {
     // Note that an exception is that, if a bridge method is for a default interface method, javac
     // will NOT generate the bridge method in the implementing class. So we need extra logic to
     // handle these bridge methods.
-    return isNonBridgeDefaultMethod(access) && !instanceMethods.contains(name + ":" + desc);
+    return isNonBridgeDefaultMethod(access) && !recordedInstanceMethod(name, desc);
   }
 
   private static boolean isNonBridgeDefaultMethod(int access) {
@@ -426,7 +418,27 @@ public class DefaultMethodClassFixer extends ClassVisitor {
   private boolean shouldStubAsBridgeDefaultMethod(int access, String name, String desc) {
     return BitFlags.isSet(access, Opcodes.ACC_BRIDGE | Opcodes.ACC_PUBLIC)
         && BitFlags.noneSet(access, Opcodes.ACC_ABSTRACT | Opcodes.ACC_STATIC)
-        && !instanceMethods.contains(name + ":" + desc);
+        && !recordedInstanceMethod(name, desc);
+  }
+
+  private void recordIfInstanceMethod(int access, String name, String desc) {
+    if (BitFlags.noneSet(access, Opcodes.ACC_STATIC)) {
+      // Record all declared instance methods, including abstract, bridge, and native methods, as
+      // they all take precedence over default methods.
+      if (coreLibrarySupport != null) {
+        // Foreshadow any type renaming to avoid issues with double-desugaring (b/111447199)
+        desc = coreLibrarySupport.getRemapper().mapMethodDesc(desc);
+      }
+      instanceMethods.add(name + ":" + desc);
+    }
+  }
+
+  private boolean recordedInstanceMethod(String name, String desc) {
+    if (coreLibrarySupport != null) {
+      // Foreshadow any type renaming to avoid issues with double-desugaring (b/111447199)
+      desc = coreLibrarySupport.getRemapper().mapMethodDesc(desc);
+    }
+    return instanceMethods.contains(name + ":" + desc);
   }
 
   /**