add binary flag for core library desugaring and gate existing configuration flags by it.

RELNOTES: None.

PiperOrigin-RevId: 187075897

2 files changed, 29 insertions, 14 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 72c7eddaad..90e6bc0884 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
@@ -17,8 +17,8 @@ import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkState;
 
 import com.google.common.base.Splitter;
-import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
 import java.lang.reflect.Method;
 import java.util.Iterator;
 import java.util.LinkedHashSet;
@@ -37,21 +37,24 @@ class CoreLibrarySupport {
   private final CoreLibraryRewriter rewriter;
   private final ClassLoader targetLoader;
   /** Internal name prefixes that we want to move to a custom package. */
-  private final ImmutableList<String> renamedPrefixes;
+  private final ImmutableSet<String> renamedPrefixes;
   /** Internal names of interfaces whose default and static interface methods we'll emulate. */
-  private final ImmutableList<Class<?>> emulatedInterfaces;
+  private final ImmutableSet<Class<?>> emulatedInterfaces;
   /** Map from {@code owner#name} core library members to their new owners. */
   private final ImmutableMap<String, String> memberMoves;
 
-  public CoreLibrarySupport(CoreLibraryRewriter rewriter, ClassLoader targetLoader,
-      ImmutableList<String> renamedPrefixes, ImmutableList<String> emulatedInterfaces,
+  public CoreLibrarySupport(
+      CoreLibraryRewriter rewriter,
+      ClassLoader targetLoader,
+      List<String> renamedPrefixes,
+      List<String> emulatedInterfaces,
       List<String> memberMoves) {
     this.rewriter = rewriter;
     this.targetLoader = targetLoader;
     checkArgument(
         renamedPrefixes.stream().allMatch(prefix -> prefix.startsWith("java/")), renamedPrefixes);
-    this.renamedPrefixes = renamedPrefixes;
-    ImmutableList.Builder<Class<?>> classBuilder = ImmutableList.builder();
+    this.renamedPrefixes = ImmutableSet.copyOf(renamedPrefixes);
+    ImmutableSet.Builder<Class<?>> classBuilder = ImmutableSet.builder();
     for (String itf : emulatedInterfaces) {
       checkArgument(itf.startsWith("java/util/"), itf);
       Class<?> clazz = loadFromInternal(rewriter.getPrefix() + itf);
diff --git a/src/tools/android/java/com/google/devtools/build/android/desugar/Desugar.java b/src/tools/android/java/com/google/devtools/build/android/desugar/Desugar.java
index eee88027b4..0fad8c2e46 100644
--- a/src/tools/android/java/com/google/devtools/build/android/desugar/Desugar.java
+++ b/src/tools/android/java/com/google/devtools/build/android/desugar/Desugar.java
@@ -196,6 +196,15 @@ class Desugar {
     public boolean tolerateMissingDependencies;
 
     @Option(
+      name = "desugar_supported_core_libs",
+      defaultValue = "false",
+      documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
+      effectTags = {OptionEffectTag.UNKNOWN},
+      help = "Enable core library desugaring, which requires configuration with related flags."
+    )
+    public boolean desugarCoreLibs;
+
+    @Option(
       name = "desugar_interface_method_bodies_if_needed",
       defaultValue = "true",
       category = "misc",
@@ -393,15 +402,14 @@ class Desugar {
       ImmutableSet.Builder<String> interfaceLambdaMethodCollector = ImmutableSet.builder();
       ClassVsInterface interfaceCache = new ClassVsInterface(classpathReader);
       CoreLibrarySupport coreLibrarySupport =
-          options.rewriteCoreLibraryPrefixes.isEmpty()
-                  && options.emulateCoreLibraryInterfaces.isEmpty()
-              ? null
-              : new CoreLibrarySupport(
+          options.desugarCoreLibs
+              ? new CoreLibrarySupport(
                   rewriter,
                   loader,
-                  ImmutableList.copyOf(options.rewriteCoreLibraryPrefixes),
-                  ImmutableList.copyOf(options.emulateCoreLibraryInterfaces),
-                  options.retargetCoreLibraryMembers);
+                  options.rewriteCoreLibraryPrefixes,
+                  options.emulateCoreLibraryInterfaces,
+                  options.retargetCoreLibraryMembers)
+          : null;
 
       desugarClassesInInput(
           inputFiles,
@@ -900,6 +908,10 @@ class Desugar {
     for (Path path : options.bootclasspath) {
       checkArgument(!Files.isDirectory(path), "Bootclasspath entry must be a jar file: %s", path);
     }
+    checkArgument(!options.desugarCoreLibs
+        || !options.rewriteCoreLibraryPrefixes.isEmpty()
+        || !options.emulateCoreLibraryInterfaces.isEmpty(),
+        "--desugar_supported_core_libs requires specifying renamed and/or emulated core libraries");
     return options;
   }