clang: Add a tool for MessageLoop refactoring

tools/clang/refactor_message_loop/update_task_runner_headers.sh

Index: tools/clang/refactor_message_loop/update_task_runner_headers.sh
diff --git a/tools/clang/refactor_message_loop/update_task_runner_headers.sh b/tools/clang/refactor_message_loop/update_task_runner_headers.sh
new file mode 100755
index 0000000000000000000000000000000000000000..bba17470d616d3ca453685aab73587aab3dc3380
--- /dev/null
+++ b/tools/clang/refactor_message_loop/update_task_runner_headers.sh
@@ -0,0 +1,98 @@
+#!/bin/sh
+# Copyright 2015 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.
+#
+# Fixes up includes in files which have been rewritten to use
+# ThreadTaskRunnerHandle.
+
+set -e
+
+echo "Warning: This script throws away uncommitted changes!"
+echo "Hit Ctrl-C now unless you know what you are doing."
+read
+
+function modified_files {
+  git diff --numstat | awk "{print \$3;}"
+}
+
+# Include TTRH instead of MLP.
+#tools/git/mffr.py -f base/message_loop/message_loop_proxy[.]h \
+#    base/thread_task_runner_handle.h
+
+# Add an include to files which use TTRH/STTR but don't include or forward
+# declare it.
+function is_missing_include {
+  local fn=$1
+  local symbol=$2
+  local include=$3
+
+  # If the .h for this .cc includes the header, don't add it again.
+  local header=${fn/.cc/.h}
+  if [ -f "$header" ]; then
+    if grep -q "$include" "$header"; then return 1; fi
+  fi
+
+  grep -q "$symbol" "$fn" && \
+      ! grep -q "$include" "$fn" && \
+      ! grep -q "class $symbol;" "$fn"
+}
+
+function add_missing_include {
+  local fn=$1
+  local include=$2
+  echo "Adding $include to $fn"
+  # Add the new header after the second #include "..." directive in the file.
+  awk "\$0 ~ /#include \"/ { n++ }
+       n == 2 && !done {
+         print \"#include \\\"$include\\\"\";
+         done = 1
+       }
+       { print }" "$fn" > "$fn.tmp"
+  mv "$fn.tmp" "$fn"
+}
+
+# Fix forward declarations.
+for f in $(modified_files); do
+  sed -i "s/class MessageLoopProxy;/class SingleThreadTaskRunner;/" "$f"
+done
+
+# Remove base/message_loop/message_loop.h and message_loop_proxy.h includes.
+for f in $(modified_files); do
+  sed -i "/#include \"base\/message_loop\/message_loop.h\"/d" "$f"
+  sed -i "/#include \"base\/message_loop\/message_loop_proxy.h\"/d" "$f"
+done
+
+# Add fast paths for getting the task runner from a thread.
+for f in $(modified_files); do
+  sed -i "s/message_loop()->task_runner()/task_runner()/" "$f"
+done
+
+# Add missing includes to all the modified files. Process .h before .cc.
+for f in $(modified_files | sort --reverse); do
+  if is_missing_include $f ThreadTaskRunnerHandle \
+      base/thread_task_runner_handle[.]h; then
+    add_missing_include $f base/thread_task_runner_handle.h
+  fi
+  if is_missing_include $f SingleThreadTaskRunner \
+      base/single_thread_task_runner[.]h; then
+    add_missing_include $f base/single_thread_task_runner.h
+  fi
+  if is_missing_include $f [^_]FROM_HERE \
+      base/location[.]h; then
+    add_missing_include $f base/location.h
+  fi
+  if is_missing_include $f Post.*Task\( \
+      base/single_thread_task_runner[.]h; then
+    add_missing_include $f base/single_thread_task_runner.h
+  fi
+done
+
+# Fix header sorting.
+tools/sort-headers.py -f $(modified_files) > /dev/null
+
+# Revert any modifications in files that don't match the given pattern.
+pattern=$1
+if [ -n "$pattern" ]; then
+  git checkout $(modified_files | grep -v "$pattern")
+fi