Make KeepScanner tool search classpath for nearest definition of each member reference, instead of potentially referring to a subtype.

Refactor desugar's class loading machinery and related code into a separate package for easier reuse in this tool.
RELNOTES: None.

PiperOrigin-RevId: 188825305
GitOrigin-RevId: 2cbeb24a9c41c6b14ecbb26e2e198fbaf79aea64
Change-Id: Ie2969cb1e1c86aa68c5a6dc0be6b42b09dfaee70

1 files changed, 10 insertions, 38 deletions

diff --git a/java/com/google/devtools/build/android/desugar/Desugar.java b/java/com/google/devtools/build/android/desugar/Desugar.java
index 506a380..c176f9c 100644
--- a/java/com/google/devtools/build/android/desugar/Desugar.java
+++ b/java/com/google/devtools/build/android/desugar/Desugar.java
@@ -27,14 +27,19 @@ import com.google.common.io.ByteStreams;
 import com.google.common.io.Closer;
 import com.google.devtools.build.android.Converters.ExistingPathConverter;
 import com.google.devtools.build.android.Converters.PathConverter;
-import com.google.devtools.build.android.desugar.CoreLibraryRewriter.UnprefixingClassWriter;
+import com.google.devtools.build.android.desugar.io.CoreLibraryRewriter;
+import com.google.devtools.build.android.desugar.io.CoreLibraryRewriter.UnprefixingClassWriter;
+import com.google.devtools.build.android.desugar.io.HeaderClassLoader;
+import com.google.devtools.build.android.desugar.io.IndexedInputs;
+import com.google.devtools.build.android.desugar.io.InputFileProvider;
+import com.google.devtools.build.android.desugar.io.OutputFileProvider;
+import com.google.devtools.build.android.desugar.io.ThrowingClassLoader;
 import com.google.devtools.common.options.Option;
 import com.google.devtools.common.options.OptionDocumentationCategory;
 import com.google.devtools.common.options.OptionEffectTag;
 import com.google.devtools.common.options.OptionsBase;
 import com.google.devtools.common.options.OptionsParser;
 import com.google.devtools.common.options.ShellQuotedParamsFilePreProcessor;
-import com.google.errorprone.annotations.MustBeClosed;
 import java.io.IOError;
 import java.io.IOException;
 import java.io.InputStream;
@@ -386,8 +391,8 @@ class Desugar {
         Files.isDirectory(inputPath) || !Files.isDirectory(outputPath),
         "Input jar file requires an output jar file");
 
-    try (OutputFileProvider outputFileProvider = toOutputFileProvider(outputPath);
-        InputFileProvider inputFiles = toInputFileProvider(inputPath)) {
+    try (OutputFileProvider outputFileProvider = OutputFileProvider.create(outputPath);
+        InputFileProvider inputFiles = InputFileProvider.open(inputPath)) {
       DependencyCollector depsCollector = createDepsCollector();
       IndexedInputs indexedInputFiles = new IndexedInputs(ImmutableList.of(inputFiles));
       // Prepend classpath with input file itself so LambdaDesugaring can load classes with
@@ -942,19 +947,6 @@ class Desugar {
     return ioPairListbuilder.build();
   }
 
-  @VisibleForTesting
-  static class ThrowingClassLoader extends ClassLoader {
-    @Override
-    protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
-      if (name.startsWith("java.")) {
-        // Use system class loader for java. classes, since ClassLoader.defineClass gets
-        // grumpy when those don't come from the standard place.
-        return super.loadClass(name, resolve);
-      }
-      throw new ClassNotFoundException();
-    }
-  }
-
   private static void deleteTreeOnExit(final Path directory) {
     Thread shutdownHook =
         new Thread() {
@@ -993,26 +985,6 @@ class Desugar {
     }
   }
 
-  /** Transform a Path to an {@link OutputFileProvider} */
-  @MustBeClosed
-  private static OutputFileProvider toOutputFileProvider(Path path) throws IOException {
-    if (Files.isDirectory(path)) {
-      return new DirectoryOutputFileProvider(path);
-    } else {
-      return new ZipOutputFileProvider(path);
-    }
-  }
-
-  /** Transform a Path to an InputFileProvider that needs to be closed by the caller. */
-  @MustBeClosed
-  private static InputFileProvider toInputFileProvider(Path path) throws IOException {
-    if (Files.isDirectory(path)) {
-      return new DirectoryInputFileProvider(path);
-    } else {
-      return new ZipInputFileProvider(path);
-    }
-  }
-
   /**
    * Transform a list of Path to a list of InputFileProvider and register them with the given
    * closer.
@@ -1023,7 +995,7 @@ class Desugar {
       Closer closer, List<Path> paths) throws IOException {
     ImmutableList.Builder<InputFileProvider> builder = new ImmutableList.Builder<>();
     for (Path path : paths) {
-      builder.add(closer.register(toInputFileProvider(path)));
+      builder.add(closer.register(InputFileProvider.open(path)));
     }
     return builder.build();
   }