roll-forward of "Delete temporary directory on exit"

*** Reason for rollback ***

Bazel build is fixed by making fields referenced from inner class final.  Clean reapply of commit 9a05f3bc58f9845bf41f9f8031e97b09e5348855 with "Path directory" arguments changed to "final Path directory".

*** Original change description ***

Revert "Delete temporary directory on exit"

This reverts commit 9a05f3bc58f9845bf41f9f8031e97b09e5348855.

This change breaks Bazel:

http://ci.bazel.io/job/bazel-tests/555/BAZEL_VERSION=HEAD,PLATFORM_NAME=windows-x86_64/console

Fixes #2552

--
PiperOrigin-RevId: 148293996
MOS_MIGRATED_REVID=148293996

GitOrigin-RevId: c9333b4996679c7f7120ff6dad087790b34908f6
Change-Id: I0eb3b59a25524e0e2dc1869da212861cdd8d3951

1 files changed, 43 insertions, 0 deletions

diff --git a/java/com/google/devtools/build/android/desugar/Desugar.java b/java/com/google/devtools/build/android/desugar/Desugar.java
index 9fdd829..2d973de 100644
--- a/java/com/google/devtools/build/android/desugar/Desugar.java
+++ b/java/com/google/devtools/build/android/desugar/Desugar.java
@@ -27,9 +27,12 @@ import com.google.devtools.common.options.OptionsParser;
 import java.io.BufferedOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.nio.file.FileVisitResult;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.nio.file.SimpleFileVisitor;
+import java.nio.file.attribute.BasicFileAttributes;
 import java.util.Enumeration;
 import java.util.List;
 import java.util.Map;
@@ -124,6 +127,8 @@ class Desugar {
     System.setProperty(
         LambdaClassMaker.LAMBDA_METAFACTORY_DUMPER_PROPERTY, dumpDirectory.toString());
 
+    deleteTreeOnExit(dumpDirectory);
+
     if (args.length == 1 && args[0].startsWith("@")) {
       args = Files.readAllLines(Paths.get(args[0].substring(1)), ISO_8859_1).toArray(new String[0]);
     }
@@ -288,4 +293,42 @@ class Desugar {
       throw new ClassNotFoundException();
     }
   }
+
+  private static void deleteTreeOnExit(final Path directory) {
+    Thread shutdownHook =
+        new Thread() {
+          @Override
+          public void run() {
+            try {
+              deleteTree(directory);
+            } catch (IOException e) {
+              throw new RuntimeException("Failed to delete " + directory, e);
+            }
+          }
+        };
+    Runtime.getRuntime().addShutdownHook(shutdownHook);
+  }
+
+  /** Recursively delete a directory. */
+  private static void deleteTree(final Path directory) throws IOException {
+    if (directory.toFile().exists()) {
+      Files.walkFileTree(
+          directory,
+          new SimpleFileVisitor<Path>() {
+            @Override
+            public FileVisitResult visitFile(Path file, BasicFileAttributes attrs)
+                throws IOException {
+              Files.delete(file);
+              return FileVisitResult.CONTINUE;
+            }
+
+            @Override
+            public FileVisitResult postVisitDirectory(Path dir, IOException exc)
+                throws IOException {
+              Files.delete(dir);
+              return FileVisitResult.CONTINUE;
+            }
+          });
+    }
+  }
 }