Fix some build symbol configuration.

Remove -gdwarf-4 from GYP build. This is the default for GCC 4.8 which is now required, so this command-line argument is redundant.

Only set use_debug_fission in the GN build in debug mode. This matches GYP. Release mode symbols will be non-fission.

Implement linux_symbols target in GN. Convert dump_app_syms from sh to Python for better GN usability, and it's more readable for normal programmers on the team.

Reland of https://codereview.chromium.org/1179393004/

TBR=thakis@chromium.org

Review URL: https://codereview.chromium.org/1182663007

Cr-Original-Commit-Position: refs/heads/master@{#334690}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 07d847b1c5451748f16f4e7973ce8ef9078d47a2

common.gypi

@@ -3693,7 +3693,6 @@
             'cflags': [
               '-O>(debug_optimize)',
               '-g',
-              '-gdwarf-4',
             ],
             'conditions' : [
               ['OS=="android" and target_arch!="mipsel" and target_arch!="mips64el"', {

config/compiler/BUILD.gn

@@ -51,8 +51,8 @@ declare_args() {
   # with some utilities such as icecc and ccache. Requires gold and
   # gcc >= 4.8 or clang.
   # http://gcc.gnu.org/wiki/DebugFission
-  use_debug_fission =
+  use_debug_fission = is_debug && !is_win && use_gold &&
-      !is_win && use_gold && linux_use_bundled_binutils && !use_ccache
+                      linux_use_bundled_binutils && !use_ccache
 
   if (is_win) {
     # Whether the VS xtree header has been patched to disable warning 4702. If

linux/dump_app_syms

@@ -1,36 +0,0 @@
-#!/bin/sh
-
-# Copyright (c) 2010 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.
-#
-# Helper script to run dump_syms on Chrome Linux executables and strip
-# them if needed.
-
-set -e
-
-usage() {
-  echo -n "$0 <dump_syms_exe> <strip_binary> " >&2
-  echo "<binary_with_symbols> <symbols_output>" >&2
-}
-
-
-if [ $# -ne 4 ]; then
-  usage
-  exit 1
-fi
-
-SCRIPTDIR="$(readlink -f "$(dirname "$0")")"
-DUMPSYMS="$1"
-STRIP_BINARY="$2"
-INFILE="$3"
-OUTFILE="$4"
-
-# Dump the symbols from the given binary.
-if [ ! -e "$OUTFILE" -o "$INFILE" -nt "$OUTFILE" ]; then
-  "$DUMPSYMS" -r "$INFILE" > "$OUTFILE"
-fi
-
-if [ "$STRIP_BINARY" != "0" ]; then
-  strip "$INFILE"
-fi

linux/dump_app_syms.py

@@ -0,0 +1,29 @@
+# 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.
+
+# Helper script to run dump_syms on Chrome Linux executables and strip
+# them if needed.
+
+import os
+import subprocess
+import sys
+
+if len(sys.argv) != 5:
+  print "dump_app_syms.py <dump_syms_exe> <strip_binary>"
+  print "                 <binary_with_symbols> <symbols_output>"
+  sys.exit(1)
+
+dumpsyms = sys.argv[1]
+strip_binary = sys.argv[2]
+infile = sys.argv[3]
+outfile = sys.argv[4]
+
+# Dump only when the output file is out-of-date.
+if not os.path.isfile(outfile) or \
+   os.stat(outfile).st_mtime > os.stat(infile).st_mtime:
+  with open(outfile, 'w') as outfileobj:
+    subprocess.check_call([dumpsyms, '-r', infile], stdout=outfileobj)
+
+if strip_binary != '0':
+  subprocess.check_call(['strip', infile])