Adds getProguardSpecsForManifest to AndroidSematics to inject proguard specs.

RELNOTES: None.
PiperOrigin-RevId: 168300744

4 files changed, 47 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/bazel/rules/android/BazelAndroidSemantics.java b/src/main/java/com/google/devtools/build/lib/bazel/rules/android/BazelAndroidSemantics.java
index a73ddde836..4331b39a55 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/rules/android/BazelAndroidSemantics.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/rules/android/BazelAndroidSemantics.java
@@ -85,6 +85,12 @@ public class BazelAndroidSemantics implements AndroidSemantics {
   }
 
   @Override
+  public ImmutableList<Artifact> getProguardSpecsForManifest(
+      RuleContext ruleContext, Artifact manifest) {
+    return ImmutableList.of();
+  }
+
+  @Override
   public void addCoverageSupport(RuleContext ruleContext, AndroidCommon common,
       JavaSemantics javaSemantics, boolean forAndroidTest, Builder attributes,
       JavaCompilationArtifacts.Builder artifactsBuilder) {
diff --git a/src/main/java/com/google/devtools/build/lib/rules/android/AndroidBinary.java b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidBinary.java
index 550597a7a1..bcf734040b 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/android/AndroidBinary.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidBinary.java
@@ -418,6 +418,20 @@ public abstract class AndroidBinary implements RuleConfiguredTargetFactory {
     ImmutableList<Artifact> proguardSpecs = ProguardHelper.collectTransitiveProguardSpecs(
         ruleContext, ImmutableList.of(resourceApk.getResourceProguardConfig()));
 
+    boolean assumeMinSdkVersion =
+        ruleContext.getFragment(AndroidConfiguration.class).assumeMinSdkVersion();
+    if (!proguardSpecs.isEmpty() && assumeMinSdkVersion) {
+      // NB: Order here is important. We're including generated Proguard specs before the user's
+      // specs so that they can override values.
+      proguardSpecs =
+          ImmutableList.<Artifact>builder()
+              .addAll(
+                  androidSemantics.getProguardSpecsForManifest(
+                      ruleContext, applicationManifest.getManifest()))
+              .addAll(proguardSpecs)
+              .build();
+    }
+
     boolean rexEnabled =
         ruleContext.getFragment(AndroidConfiguration.class).useRexToCompressDexFiles()
         || (ruleContext.attributes().get("rewrite_dexes_with_rex", Type.BOOLEAN));
diff --git a/src/main/java/com/google/devtools/build/lib/rules/android/AndroidConfiguration.java b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidConfiguration.java
index 9b8ef3b677..0d8b70d105 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/android/AndroidConfiguration.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidConfiguration.java
@@ -454,6 +454,19 @@ public class AndroidConfiguration extends BuildConfiguration.Fragment {
     )
     public boolean incrementalDexingErrorOnMissedJars;
 
+    // TODO(b/31711689): Remove this flag when this optimization is proven to work globally.
+    @Option(
+      name = "experimental_android_assume_minsdkversion",
+      defaultValue = "false",
+      metadataTags = {OptionMetadataTag.EXPERIMENTAL},
+      documentationCategory = OptionDocumentationCategory.UNDOCUMENTED,
+      effectTags = {OptionEffectTag.UNKNOWN},
+      help =
+          "When enabled, the minSdkVersion is parsed from the merged AndroidManifest and used to "
+              + "instruct Proguard on valid Android build versions."
+    )
+    public boolean assumeMinSdkVersion;
+
     @Option(
       name = "experimental_android_use_parallel_dex2oat",
       category = "experimental",
@@ -742,6 +755,7 @@ public class AndroidConfiguration extends BuildConfiguration.Fragment {
       host.incrementalDexingBinaries = incrementalDexingBinaries;
       host.incrementalDexingForLiteProtos = incrementalDexingForLiteProtos;
       host.incrementalDexingErrorOnMissedJars = incrementalDexingErrorOnMissedJars;
+      host.assumeMinSdkVersion = assumeMinSdkVersion;
       host.nonIncrementalPerTargetDexopts = nonIncrementalPerTargetDexopts;
       host.dexoptsSupportedInIncrementalDexing = dexoptsSupportedInIncrementalDexing;
       host.dexoptsSupportedInDexMerger = dexoptsSupportedInDexMerger;
@@ -785,6 +799,7 @@ public class AndroidConfiguration extends BuildConfiguration.Fragment {
   private final ImmutableSet<AndroidBinaryType> incrementalDexingBinaries;
   private final boolean incrementalDexingForLiteProtos;
   private final boolean incrementalDexingErrorOnMissedJars;
+  private final boolean assumeMinSdkVersion;
   private final ImmutableList<String> dexoptsSupportedInIncrementalDexing;
   private final ImmutableList<String> targetDexoptsThatPreventIncrementalDexing;
   private final ImmutableList<String> dexoptsSupportedInDexMerger;
@@ -821,6 +836,7 @@ public class AndroidConfiguration extends BuildConfiguration.Fragment {
     }
     this.incrementalDexingForLiteProtos = options.incrementalDexingForLiteProtos;
     this.incrementalDexingErrorOnMissedJars = options.incrementalDexingErrorOnMissedJars;
+    this.assumeMinSdkVersion = options.assumeMinSdkVersion;
     this.dexoptsSupportedInIncrementalDexing =
         ImmutableList.copyOf(options.dexoptsSupportedInIncrementalDexing);
     this.targetDexoptsThatPreventIncrementalDexing =
@@ -890,6 +906,14 @@ public class AndroidConfiguration extends BuildConfiguration.Fragment {
   }
 
   /**
+   * Returns true if an -assumevalues should be generated for Proguard based on the minSdkVersion
+   * of the merged AndroidManifest.
+   */
+  public boolean assumeMinSdkVersion() {
+    return assumeMinSdkVersion;
+  }
+
+  /**
    * dx flags supported in incremental dexing actions.
    */
   public ImmutableList<String> getDexoptsSupportedInIncrementalDexing() {
diff --git a/src/main/java/com/google/devtools/build/lib/rules/android/AndroidSemantics.java b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidSemantics.java
index f7637a7e3f..14d892460a 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/android/AndroidSemantics.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidSemantics.java
@@ -89,6 +89,9 @@ public interface AndroidSemantics {
    */
   Artifact getApkDebugSigningKey(RuleContext ruleContext);
 
+  /** Given an Android {@code manifest}, returns a list of relevant Proguard specs. */
+  ImmutableList<Artifact> getProguardSpecsForManifest(RuleContext ruleContext, Artifact manifest);
+
   /**
    * Add coverage instrumentation to the Java compilation of an Android binary.
    * @throws InterruptedException