android: Convert java_deobfuscate.py to Java

This allows it to not buffer output lines, which is essential when
piping logcat through it.

BUG=713710

Review-Url: https://codereview.chromium.org/2956153003
Cr-Commit-Position: refs/heads/master@{#484281}

BUILD.gn

@@ -273,6 +273,7 @@ group("gn_all") {
       "//base/android/linker:chromium_android_linker",
       "//build/android/gyp/test:hello_world",
       "//build/android/gyp/test:hello_world",
+      "//build/android/stacktrace:java_deobfuscate",
       "//chrome/android/webapk/shell_apk:webapk",
       "//chrome/test/vr/perf:motopho_latency_test",
       "//components/invalidation/impl:components_invalidation_impl_junit_tests",

build/android/stacktrace/BUILD.gn

@@ -0,0 +1,17 @@
+# Copyright 2017 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/config/android/rules.gni")
+
+java_binary("java_deobfuscate") {
+  main_class = "org.chromium.build.FlushingReTrace"
+  java_files = [ "java/org/chromium/build/FlushingReTrace.java" ]
+  deps = [
+    "//third_party/proguard:retrace_java",
+  ]
+  data = [
+    "$root_build_dir/lib.java/build/android/stacktrace/java_deobfuscate.jar",
+    "$root_build_dir/bin/java_deobfuscate",
+  ]
+}

build/android/stacktrace/README.md

@@ -0,0 +1,18 @@
+# java_deobfuscate
+
+A wrapper around ProGuard's ReTrace tool, which:
+
+1) Updates the regular expression used to identify stack lines, and
+2) Streams its output.
+
+The second point here is what allows you to run:
+
+    adb logcat | out/Default/bin/java_deobfuscate
+
+And have it actually show output without logcat terminating.
+
+
+# stackwalker.py
+
+Extracts Breakpad microdumps from a log file and uses `stackwalker` to symbolize
+them.

build/android/stacktrace/java/org/chromium/build/FlushingReTrace.java

@@ -0,0 +1,60 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.build;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.LineNumberReader;
+import java.io.OutputStreamWriter;
+import java.io.PrintWriter;
+
+import proguard.retrace.ReTrace;
+
+/**
+ * A wrapper around ReTrace that:
+ *  1. Hardcodes a more useful line regular expression
+ *  2. Disables output buffering
+ */
+public class FlushingReTrace {
+    // This regex is based on the one from:
+    // http://proguard.sourceforge.net/manual/retrace/usage.html.
+    // But with the "at" part changed to "(?::|\bat)", to account for lines like:
+    //     06-22 13:58:02.895  4674  4674 E THREAD_STATE:     bLA.a(PG:173)
+    // Normal stack trace lines look like:
+    // java.lang.RuntimeException: Intentional Java Crash
+    //     at org.chromium.chrome.browser.tab.Tab.handleJavaCrash(Tab.java:682)
+    //     at org.chromium.chrome.browser.tab.Tab.loadUrl(Tab.java:644)
+    private static final String LINE_PARSE_REGEX =
+            "(?:.*?(?::|\\bat)\\s+%c\\.%m\\s*\\(%s(?::%l)?\\)\\s*)|(?:(?:.*?[:\"]\\s+)?%c(?::.*)?)";
+
+    public static void main(String[] args) {
+        if (args.length != 1) {
+            System.err.println("Usage: retrace Foo.apk.map < foo.log > bar.log");
+            System.exit(1);
+        }
+
+        File mappingFile = new File(args[0]);
+        try {
+            LineNumberReader reader = new LineNumberReader(
+                    new BufferedReader(new InputStreamReader(System.in, "UTF-8")));
+
+            // Enabling autoFlush is the main difference from ReTrace.main().
+            boolean autoFlush = true;
+            PrintWriter writer =
+                    new PrintWriter(new OutputStreamWriter(System.out, "UTF-8"), autoFlush);
+
+            boolean verbose = false;
+            new ReTrace(LINE_PARSE_REGEX, verbose, mappingFile).retrace(reader, writer);
+        } catch (IOException ex) {
+            // Print a verbose stack trace.
+            ex.printStackTrace();
+            System.exit(1);
+        }
+
+        System.exit(0);
+    }
+}

build/config/android/internal_rules.gni

@@ -2058,7 +2058,11 @@ if (enable_java_templates) {
     }
 
     group(target_name) {
-      forward_variables_from(invoker, [ "data_deps" ])
+      forward_variables_from(invoker,
+                             [
+                               "data",
+                               "data_deps",
+                             ])
       public_deps = [
         ":$_ijar_target_name",
         ":$_process_jar_target_name",

docs/android_debugging_instructions.md

@@ -203,19 +203,23 @@ that crashed was built. When building locally, these are found in:
 
 ```shell
 out/Default/apks/ChromePublic.apk.mapping
-out/Default/apks/Chrome.apk.mapping
+out/Default/apks/ChromeModernPublic.apk.mapping
+etc.
 ```
 
-To deobfuscate a stack trace from a file, run
+Build the `java_deobfuscate` tool:
 
 ```shell
-build/android/stacktrace/java_deobfuscate.py PROGUARD_MAPPING_FILE.mapping --stacktrace STACKTRACE_FILE
+ninja -C out/Default java_deobfuscate
 ```
 
-Deobfuscation also works from `stdin`:
+Then run it via:
 
 ```shell
-adb logcat -d | build/android/stacktrace/java_deobfuscate.py PROGUARD_MAPPING_FILE.mapping
+# For a file:
+out/Default/bin/java_deobfuscate PROGUARD_MAPPING_FILE.mapping < FILE
+# For logcat:
+adb logcat | out/Default/bin/java_deobfuscate PROGUARD_MAPPING_FILE.mapping
 ```
 
 ## Get WebKit code to output to the adb log

third_party/proguard/BUILD.gn

@@ -0,0 +1,22 @@
+# Copyright 2017 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/config/android/rules.gni")
+
+java_prebuilt("proguard_java") {
+  jar_path = "lib/proguard.jar"
+  data = [
+    "$root_build_dir/lib.java/third_party/proguard/proguard.jar",
+  ]
+}
+
+java_prebuilt("retrace_java") {
+  jar_path = "lib/retrace.jar"
+  deps = [
+    ":proguard_java",
+  ]
+  data = [
+    "$root_build_dir/lib.java/third_party/proguard/retrace.jar",
+  ]
+}

third_party/proguard/OWNERS

@@ -1,2 +1,3 @@
+agrieve@chromium.org
 torne@chromium.org
 yfriedman@chromium.org