Add action to write android_binary and lib R.classes directly

For android_binary rules, we regenerate all of
the R.java of the libraries to get the final
resource IDs. Compiling all of them together can
be slow with the normal JavaBuilder, so add a
specialized class writer.

Example build with many R.java classes:
- R.java -> R.class via JavaBuilder: over 80s
- ErrorProne takes about 40% of that. So turning off
  ErrorProne would be projected to be 48s.
  Some of ErrorProne slowness is from static field
  checks (e.g., on Flag classes), which may look
  up the same Type over and over.

In comparison, if we write our own bytecode with ASM:
- ~16s total
- 4.7s to parse R.txt
- 4.8s to write class files
- 5.8s to copy and compress .jar

TODO: clean up SymbolLoader patching (upstream)

This only creates the action. We will need to
separately wire this up in blaze.

NOTE: This also makes the exising R.txt loading
used by live code multi-threaded, since that is
partly I/O-bound. Something to watch out for
(for flakiness, etc.) once this is submitted.

--
MOS_MIGRATED_REVID=125384467

GitOrigin-RevId: 1f1f207573c7b9c3e2d3ca1ffb0780a8fd592214
Change-Id: I4c8335a7222181b2f400cacfed8faefc549d311d

1 files changed, 32 insertions, 0 deletions

diff --git a/java/com/google/devtools/build/android/Converters.java b/java/com/google/devtools/build/android/Converters.java
index 54d1150..5fae682 100644
--- a/java/com/google/devtools/build/android/Converters.java
+++ b/java/com/google/devtools/build/android/Converters.java
@@ -95,6 +95,38 @@ public final class Converters {
   }
 
   /**
+   * Converter for a list of {@link DependencySymbolFileProvider}. Relies on
+   * {@code DependencySymbolFileProvider#valueOf(String)} to perform conversion and validation.
+   */
+  public static class DependencySymbolFileProviderListConverter
+      implements Converter<List<DependencySymbolFileProvider>> {
+
+    @Override
+    public List<DependencySymbolFileProvider> convert(String input) throws OptionsParsingException {
+      if (input.isEmpty()) {
+        return ImmutableList.<DependencySymbolFileProvider>of();
+      }
+      try {
+        ImmutableList.Builder<DependencySymbolFileProvider> builder = ImmutableList.builder();
+        for (String item : input.split(",")) {
+          builder.add(DependencySymbolFileProvider.valueOf(item));
+        }
+        return builder.build();
+      } catch (IllegalArgumentException e) {
+        throw new OptionsParsingException(
+            String.format("invalid DependencyAndroidData: %s", e.getMessage()), e);
+      }
+    }
+
+    @Override
+    public String getTypeDescription() {
+      return String.format("a list of dependency android data in the format: %s[%s]",
+          DependencySymbolFileProvider.commandlineFormat("1"),
+          DependencySymbolFileProvider.commandlineFormat("2"));
+    }
+  }
+
+  /**
    * Converter for {@link FullRevision}. Relies on {@code FullRevision#parseRevision(String)} to
    * perform conversion and validation.
    */