Add option to enable resource cycle shrinking.

This will instruct AAPT2 to produce conditional keep rules to allow for more aggressive code and resource shrinking.

RELNOTES[NEW]: Add --experimental_android_resource_cycle_shrinking option to allow for more aggressive code and resource shrinking.

PiperOrigin-RevId: 176530749

3 files changed, 20 insertions, 0 deletions

diff --git a/src/tools/android/java/com/google/devtools/build/android/Aapt2ResourcePackagingAction.java b/src/tools/android/java/com/google/devtools/build/android/Aapt2ResourcePackagingAction.java
index 9bdd1a098f..5739afa377 100644
--- a/src/tools/android/java/com/google/devtools/build/android/Aapt2ResourcePackagingAction.java
+++ b/src/tools/android/java/com/google/devtools/build/android/Aapt2ResourcePackagingAction.java
@@ -29,6 +29,7 @@ import com.google.devtools.build.android.aapt2.ResourceLinker;
 import com.google.devtools.build.android.aapt2.StaticLibrary;
 import com.google.devtools.common.options.OptionsParser;
 import com.google.devtools.common.options.ShellQuotedParamsFilePreProcessor;
+import com.google.devtools.common.options.TriState;
 import java.io.Closeable;
 import java.io.IOException;
 import java.nio.file.FileSystems;
@@ -186,6 +187,7 @@ public class Aapt2ResourcePackagingAction {
                 .include(compiledResourceDeps)
                 .withAssets(assetDirs)
                 .buildVersion(aaptConfigOptions.buildToolsVersion)
+                .conditionalKeepRules(aaptConfigOptions.conditionalKeepRules == TriState.YES)
                 .filterToDensity(densitiesToFilter)
                 .includeOnlyConfigs(aaptConfigOptions.resourceConfigs)
                 .link(compiled)
diff --git a/src/tools/android/java/com/google/devtools/build/android/aapt2/Aapt2ConfigOptions.java b/src/tools/android/java/com/google/devtools/build/android/aapt2/Aapt2ConfigOptions.java
index aa02712957..6d8d614116 100644
--- a/src/tools/android/java/com/google/devtools/build/android/aapt2/Aapt2ConfigOptions.java
+++ b/src/tools/android/java/com/google/devtools/build/android/aapt2/Aapt2ConfigOptions.java
@@ -90,6 +90,16 @@ public class Aapt2ConfigOptions extends OptionsBase {
   public TriState useAaptCruncher;
 
   @Option(
+    name = "conditionalKeepRules",
+    defaultValue = "auto",
+    category = "config",
+    documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
+    effectTags = {OptionEffectTag.UNKNOWN},
+    help = "Have AAPT2 produce conditional keep rules."
+  )
+  public TriState conditionalKeepRules;
+
+  @Option(
       name = "uncompressedExtensions",
       defaultValue = "",
       converter = CommaSeparatedOptionListConverter.class,
diff --git a/src/tools/android/java/com/google/devtools/build/android/aapt2/ResourceLinker.java b/src/tools/android/java/com/google/devtools/build/android/aapt2/ResourceLinker.java
index 309fa235ab..2787722c36 100644
--- a/src/tools/android/java/com/google/devtools/build/android/aapt2/ResourceLinker.java
+++ b/src/tools/android/java/com/google/devtools/build/android/aapt2/ResourceLinker.java
@@ -63,6 +63,7 @@ public class ResourceLinker {
   private Path baseApk;
   private List<CompiledResources> include = ImmutableList.of();
   private List<Path> assetDirs = ImmutableList.of();
+  private boolean conditionalKeepRules = false;
 
   private ResourceLinker(Path aapt2, Path workingDirectory) {
     this.aapt2 = aapt2;
@@ -101,6 +102,11 @@ public class ResourceLinker {
     return this;
   }
 
+  public ResourceLinker conditionalKeepRules(boolean conditionalKeepRules) {
+    this.conditionalKeepRules = conditionalKeepRules;
+    return this;
+  }
+
   public ResourceLinker baseApkToLinkAgainst(Path baseApk) {
     this.baseApk = baseApk;
     return this;
@@ -243,6 +249,8 @@ public class ResourceLinker {
               .add("--java", javaSourceDirectory)
               .add("--proguard", proguardConfig)
               .add("--proguard-main-dex", mainDexProguard)
+              .when(conditionalKeepRules)
+              .thenAdd("--proguard-conditional-keep-rules")
               .add("-o", outPath)
               .execute(String.format("Linking %s", compiled.getManifest())));
       profiler.recordEndOf("fulllink");