Fix python scripts in src/build/

Make sure that:
- shebang is only present for executable files
- shebang is #!/usr/bin/env python
- __main__ is only present for executable files
- file's executable bit is coherent

Also fix EOF LF to be only one.

TBR=michaelbai@chromium.org
BUG=105108
TEST=

Review URL: http://codereview.chromium.org/8667008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@111385 0039d316-1c4b-4281-b951-d872f2087c98

24 files changed, 122 insertions, 119 deletions

diff --git a/build/android/android_commands.py b/build/android/android_commands.py
index 27c1c3d..af1a6b8 100755
--- a/build/android/android_commands.py
+++ b/build/android/android_commands.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 # Copyright (c) 2011 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.
diff --git a/build/android/base_test_runner.py b/build/android/base_test_runner.py
index 95d7e4f..bb0316b 100644
--- a/build/android/base_test_runner.py
+++ b/build/android/base_test_runner.py
@@ -1,4 +1,3 @@
-#!/usr/bin/python
 # Copyright (c) 2011 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.
diff --git a/build/android/cmd_helper.py b/build/android/cmd_helper.py
index bedab94..901cbe9a 100644
--- a/build/android/cmd_helper.py
+++ b/build/android/cmd_helper.py
@@ -1,4 +1,3 @@
-#!/usr/bin/python
 # Copyright (c) 2011 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.
diff --git a/build/android/debug_info.py b/build/android/debug_info.py
index f4df79c..9a836e3 100644
--- a/build/android/debug_info.py
+++ b/build/android/debug_info.py
@@ -1,4 +1,3 @@
-#!/usr/bin/python
 # Copyright (c) 2011 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.
diff --git a/build/android/emulator.py b/build/android/emulator.py
index a42564a..8e7031c 100755
--- a/build/android/emulator.py
+++ b/build/android/emulator.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 # Copyright (c) 2011 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.
diff --git a/build/android/flag_changer.py b/build/android/flag_changer.py
index 636022b..2c3da49 100644
--- a/build/android/flag_changer.py
+++ b/build/android/flag_changer.py
@@ -1,4 +1,3 @@
-#!/usr/bin/python
 # Copyright (c) 2011 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.
diff --git a/build/android/lighttpd_server.py b/build/android/lighttpd_server.py
index 45bfcd0..ffe985b 100755
--- a/build/android/lighttpd_server.py
+++ b/build/android/lighttpd_server.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 # Copyright (c) 2011 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.
diff --git a/build/android/perf_tests_helper.py b/build/android/perf_tests_helper.py
index 39bf587..740c455 100644
--- a/build/android/perf_tests_helper.py
+++ b/build/android/perf_tests_helper.py
@@ -1,4 +1,3 @@
-#!/usr/bin/python
 # Copyright (c) 2011 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.
diff --git a/build/android/run_tests.py b/build/android/run_tests.py
index aa25e154..b1b6a1d 100755
--- a/build/android/run_tests.py
+++ b/build/android/run_tests.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 # Copyright (c) 2011 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.
diff --git a/build/android/run_tests_helper.py b/build/android/run_tests_helper.py
index dcdc8b2..45e3afd 100644
--- a/build/android/run_tests_helper.py
+++ b/build/android/run_tests_helper.py
@@ -1,4 +1,3 @@
-#!/usr/bin/python
 # Copyright (c) 2011 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.
diff --git a/build/android/single_test_runner.py b/build/android/single_test_runner.py
index c238f5d..8ec9501 100755
--- a/build/android/single_test_runner.py
+++ b/build/android/single_test_runner.py
@@ -1,4 +1,3 @@
-#!/usr/bin/python
 # Copyright (c) 2011 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.
diff --git a/build/android/test_package.py b/build/android/test_package.py
index d81f0fc..433e7f1 100644
--- a/build/android/test_package.py
+++ b/build/android/test_package.py
@@ -1,4 +1,3 @@
-#!/usr/bin/python
 # Copyright (c) 2011 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.
diff --git a/build/android/test_package_executable.py b/build/android/test_package_executable.py
index 6390735..badea4a 100644
--- a/build/android/test_package_executable.py
+++ b/build/android/test_package_executable.py
@@ -1,4 +1,3 @@
-#!/usr/bin/python
 # Copyright (c) 2011 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.
diff --git a/build/android/test_result.py b/build/android/test_result.py
index e5b0dc1..eb468f3 100644
--- a/build/android/test_result.py
+++ b/build/android/test_result.py
@@ -1,4 +1,3 @@
-#!/usr/bin/python
 # Copyright (c) 2011 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.
diff --git a/build/android/valgrind_tools.py b/build/android/valgrind_tools.py
index bd008dd..bc917e6 100644
--- a/build/android/valgrind_tools.py
+++ b/build/android/valgrind_tools.py
@@ -1,4 +1,3 @@
-#!/usr/bin/python
 # Copyright (c) 2011 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.
diff --git a/build/compiler_version.py b/build/compiler_version.py
index 69f0a50..9132261 100755
--- a/build/compiler_version.py
+++ b/build/compiler_version.py
@@ -1,6 +1,5 @@
-#!/usr/bin/python
-
-# Copyright (c) 2009 The Chromium Authors. All rights reserved.
+#!/usr/bin/env python
+# Copyright (c) 2011 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.
 
diff --git a/build/dir_exists.py b/build/dir_exists.py
index d1c194f..0a89bc8 100644..100755
--- a/build/dir_exists.py
+++ b/build/dir_exists.py
@@ -1,10 +1,15 @@
 #!/usr/bin/env python
-# Copyright (c) 2009 The Chromium Authors. All rights reserved.
+# Copyright (c) 2011 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.
+"""Writes True if the argument is a directory."""
 
 import os.path
 import sys
 
-sys.stdout.write(str(os.path.isdir(sys.argv[1])))
-sys.exit(0)
+def main():
+  sys.stdout.write(str(os.path.isdir(sys.argv[1])))
+  return 0
+
+if __name__ == '__main__':
+  sys.exit(main())
diff --git a/build/download_nacl_toolchains.py b/build/download_nacl_toolchains.py
index 1768d80..f988891 100755
--- a/build/download_nacl_toolchains.py
+++ b/build/download_nacl_toolchains.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 # Copyright (c) 2011 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.
@@ -36,7 +36,8 @@ def Main(args):
   sys.path.insert(0, nacl_build_dir)
   import download_toolchains
   download_toolchains.Main(args)
+  return 0
 
 
 if __name__ == '__main__':
-  Main(sys.argv[1:])
+  sys.exit(Main(sys.argv[1:]))
diff --git a/build/escape_unicode.py b/build/escape_unicode.py
index 5d4410e..859ba5d 100755
--- a/build/escape_unicode.py
+++ b/build/escape_unicode.py
@@ -1,5 +1,4 @@
-#!/usr/bin/python
-
+#!/usr/bin/env python
 # Copyright (c) 2011 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.
@@ -11,6 +10,7 @@ import optparse
 import os
 import sys
 
+
 def main(argv):
   parser = optparse.OptionParser()
   usage = 'Usage: %prog -o <output_dir> <input_file>'
@@ -37,6 +37,7 @@ def main(argv):
       os.path.splitext(in_filename)[0]))
 
   WriteEscapedFile(in_filename, out_filename)
+  return 0
 
 
 def WriteEscapedFile(in_filename, out_filename):
@@ -52,4 +53,4 @@ def WriteEscapedFile(in_filename, out_filename):
 
 
 if __name__ == '__main__':
-  exit(main(sys.argv))
+  sys.exit(main(sys.argv))
diff --git a/build/extract_from_cab.py b/build/extract_from_cab.py
index fd99184..9320462 100644..100755
--- a/build/extract_from_cab.py
+++ b/build/extract_from_cab.py
@@ -1,27 +1,35 @@
 #!/usr/bin/env python
-# Copyright (c) 2009 The Chromium Authors. All rights reserved.
+# Copyright (c) 2011 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.
 
-# Extracts a single file from a CAB archive.
+"""Extracts a single file from a CAB archive."""
 
 import os
 import subprocess
 import sys
 
-if len(sys.argv) != 4:
-  print 'Usage: extract_from_cab.py cab_path archived_file output_dir'
-  sys.exit(1)
 
-[cab_path, archived_file, output_dir] = sys.argv[1:]
+def main():
+  if len(sys.argv) != 4:
+    print 'Usage: extract_from_cab.py cab_path archived_file output_dir'
+    return 1
 
-# Invoke the Windows expand utility to extract the file.
-level = subprocess.call(['expand', cab_path, '-F:' + archived_file, output_dir])
-if level != 0:
-  sys.exit(level)
+  [cab_path, archived_file, output_dir] = sys.argv[1:]
 
-# The expand utility preserves the modification date and time of the archived
-# file. Touch the extracted file. This helps build systems that compare the
-# modification times of input and output files to determine whether to do an
-# action.
-os.utime(os.path.join(output_dir, archived_file), None)
+  # Invoke the Windows expand utility to extract the file.
+  level = subprocess.call(
+      ['expand', cab_path, '-F:' + archived_file, output_dir])
+  if level != 0:
+    return level
+
+  # The expand utility preserves the modification date and time of the archived
+  # file. Touch the extracted file. This helps build systems that compare the
+  # modification times of input and output files to determine whether to do an
+  # action.
+  os.utime(os.path.join(output_dir, archived_file), None)
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())
diff --git a/build/linux/rewrite_dirs.py b/build/linux/rewrite_dirs.py
index 9e166d0..30f22f0 100755
--- a/build/linux/rewrite_dirs.py
+++ b/build/linux/rewrite_dirs.py
@@ -1,5 +1,5 @@
-#!/usr/bin/python
-# Copyright (c) 2009 The Chromium Authors. All rights reserved.
+#!/usr/bin/env python
+# Copyright (c) 2011 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.
 
@@ -31,6 +31,7 @@ def RewritePath(path, opts):
   else:
     return path
 
+
 def RewriteLine(line, opts):
   """Rewrites all the paths in recognized options."""
   args = line.split()
@@ -53,6 +54,7 @@ def RewriteLine(line, opts):
 
   return ' '.join(args)
 
+
 def main(argv):
   parser = optparse.OptionParser()
   parser.add_option('-s', '--sysroot', default='/', help='sysroot to prepend')
@@ -64,5 +66,6 @@ def main(argv):
     print line
   return 0
 
+
 if __name__ == '__main__':
   sys.exit(main(sys.argv))
diff --git a/build/mac/change_mach_o_flags.py b/build/mac/change_mach_o_flags.py
index 1dfe07f..c2aeaec 100755
--- a/build/mac/change_mach_o_flags.py
+++ b/build/mac/change_mach_o_flags.py
@@ -1,78 +1,77 @@
-#!/usr/bin/python
-
+#!/usr/bin/env python
 # Copyright (c) 2011 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.
 
-# Usage: change_mach_o_flags.py [--executable-heap] [--no-pie] <executable_path>
-#
-# Arranges for the executable at |executable_path| to have its data (heap)
-# pages protected to prevent execution on Mac OS X 10.7 ("Lion"), and to have
-# the PIE (position independent executable) bit set to enable ASLR (address
-# space layout randomization). With --executable-heap or --no-pie, the
-# respective bits are cleared instead of set, making the heap executable or
-# disabling PIE/ASLR.
-#
-# This script is able to operate on thin (single-architecture) Mach-O files
-# and fat (universal, multi-architecture) files. When operating on fat files,
-# it will set or clear the bits for each architecture contained therein.
-#
-# NON-EXECUTABLE HEAP
-#
-# Traditionally in Mac OS X, 32-bit processes did not have data pages set to
-# prohibit execution. Although user programs could call mprotect and
-# mach_vm_protect to deny execution of code in data pages, the kernel would
-# silently ignore such requests without updating the page tables, and the
-# hardware would happily execute code on such pages. 64-bit processes were
-# always given proper hardware protection of data pages. This behavior was
-# controllable on a system-wide level via the vm.allow_data_exec sysctl, which
-# is set by default to 1. The bit with value 1 (set by default) allows code
-# execution on data pages for 32-bit processes, and the bit with value 2
-# (clear by default) does the same for 64-bit processes.
-#
-# In Mac OS X 10.7, executables can "opt in" to having hardware protection
-# against code execution on data pages applied. This is done by setting a new
-# bit in the |flags| field of an executable's |mach_header|. When
-# MH_NO_HEAP_EXECUTION is set, proper protections will be applied, regardless
-# of the setting of vm.allow_data_exec. See xnu-1699.22.73/osfmk/vm/vm_map.c
-# override_nx and xnu-1699.22.73/bsd/kern/mach_loader.c load_machfile.
-#
-# The Apple toolchain has been revised to set the MH_NO_HEAP_EXECUTION when
-# producing executables, provided that -allow_heap_execute is not specified
-# at link time. Only linkers shipping with Xcode 4.0 and later (ld64-123.2 and
-# later) have this ability. See ld64-123.2.1/src/ld/Options.cpp
-# Options::reconfigureDefaults() and
-# ld64-123.2.1/src/ld/HeaderAndLoadCommands.hpp
-# HeaderAndLoadCommandsAtom<A>::flags().
-#
-# This script sets the MH_NO_HEAP_EXECUTION bit on Mach-O executables. It is
-# intended for use with executables produced by a linker that predates Apple's
-# modifications to set this bit itself. It is also useful for setting this bit
-# for non-i386 executables, including x86_64 executables. Apple's linker only
-# sets it for 32-bit i386 executables, presumably under the assumption that
-# the value of vm.allow_data_exec is set in stone. However, if someone were to
-# change vm.allow_data_exec to 2 or 3, 64-bit x86_64 executables would run
-# without hardware protection against code execution on data pages. This
-# script can set the bit for x86_64 executables, guaranteeing that they run
-# with appropriate protection even when vm.allow_data_exec has been tampered
-# with.
-#
-# POSITION-INDEPENDENT EXECUTABLES/ADDRESS SPACE LAYOUT RANDOMIZATION
-#
-# This script sets or clears the MH_PIE bit in an executable's Mach-O header,
-# enabling or disabling position independence on Mac OS X 10.5 and later.
-# Processes running position-independent executables have varying levels of
-# ASLR protection depending on the OS release. The main executable's load
-# address, shared library load addresess, and the heap and stack base
-# addresses may be randomized. Position-independent executables are produced
-# by supplying the -pie flag to the linker (or defeated by supplying -no_pie).
-# Executables linked with a deployment target of 10.7 or higher have PIE on
-# by default.
-#
-# This script is never strictly needed during the build to enable PIE, as all
-# linkers used are recent enough to support -pie. However, it's used to
-# disable the PIE bit as needed on already-linked executables.
-
+"""Usage: change_mach_o_flags.py [--executable-heap] [--no-pie] <executablepath>
+
+Arranges for the executable at |executable_path| to have its data (heap)
+pages protected to prevent execution on Mac OS X 10.7 ("Lion"), and to have
+the PIE (position independent executable) bit set to enable ASLR (address
+space layout randomization). With --executable-heap or --no-pie, the
+respective bits are cleared instead of set, making the heap executable or
+disabling PIE/ASLR.
+
+This script is able to operate on thin (single-architecture) Mach-O files
+and fat (universal, multi-architecture) files. When operating on fat files,
+it will set or clear the bits for each architecture contained therein.
+
+NON-EXECUTABLE HEAP
+
+Traditionally in Mac OS X, 32-bit processes did not have data pages set to
+prohibit execution. Although user programs could call mprotect and
+mach_vm_protect to deny execution of code in data pages, the kernel would
+silently ignore such requests without updating the page tables, and the
+hardware would happily execute code on such pages. 64-bit processes were
+always given proper hardware protection of data pages. This behavior was
+controllable on a system-wide level via the vm.allow_data_exec sysctl, which
+is set by default to 1. The bit with value 1 (set by default) allows code
+execution on data pages for 32-bit processes, and the bit with value 2
+(clear by default) does the same for 64-bit processes.
+
+In Mac OS X 10.7, executables can "opt in" to having hardware protection
+against code execution on data pages applied. This is done by setting a new
+bit in the |flags| field of an executable's |mach_header|. When
+MH_NO_HEAP_EXECUTION is set, proper protections will be applied, regardless
+of the setting of vm.allow_data_exec. See xnu-1699.22.73/osfmk/vm/vm_map.c
+override_nx and xnu-1699.22.73/bsd/kern/mach_loader.c load_machfile.
+
+The Apple toolchain has been revised to set the MH_NO_HEAP_EXECUTION when
+producing executables, provided that -allow_heap_execute is not specified
+at link time. Only linkers shipping with Xcode 4.0 and later (ld64-123.2 and
+later) have this ability. See ld64-123.2.1/src/ld/Options.cpp
+Options::reconfigureDefaults() and
+ld64-123.2.1/src/ld/HeaderAndLoadCommands.hpp
+HeaderAndLoadCommandsAtom<A>::flags().
+
+This script sets the MH_NO_HEAP_EXECUTION bit on Mach-O executables. It is
+intended for use with executables produced by a linker that predates Apple's
+modifications to set this bit itself. It is also useful for setting this bit
+for non-i386 executables, including x86_64 executables. Apple's linker only
+sets it for 32-bit i386 executables, presumably under the assumption that
+the value of vm.allow_data_exec is set in stone. However, if someone were to
+change vm.allow_data_exec to 2 or 3, 64-bit x86_64 executables would run
+without hardware protection against code execution on data pages. This
+script can set the bit for x86_64 executables, guaranteeing that they run
+with appropriate protection even when vm.allow_data_exec has been tampered
+with.
+
+POSITION-INDEPENDENT EXECUTABLES/ADDRESS SPACE LAYOUT RANDOMIZATION
+
+This script sets or clears the MH_PIE bit in an executable's Mach-O header,
+enabling or disabling position independence on Mac OS X 10.5 and later.
+Processes running position-independent executables have varying levels of
+ASLR protection depending on the OS release. The main executable's load
+address, shared library load addresess, and the heap and stack base
+addresses may be randomized. Position-independent executables are produced
+by supplying the -pie flag to the linker (or defeated by supplying -no_pie).
+Executables linked with a deployment target of 10.7 or higher have PIE on
+by default.
+
+This script is never strictly needed during the build to enable PIE, as all
+linkers used are recent enough to support -pie. However, it's used to
+disable the PIE bit as needed on already-linked executables.
+"""
 
 import optparse
 import os
@@ -267,8 +266,8 @@ def main(me, args):
     raise MachOError, '%s is not a Mach-O or fat file' % executable_file
 
   executable_file.close()
-
   return 0
 
+
 if __name__ == '__main__':
   sys.exit(main(sys.argv[0], sys.argv[1:]))
diff --git a/build/scan_sources.py b/build/scan_sources.py
index 60febef..2b0e806 100755
--- a/build/scan_sources.py
+++ b/build/scan_sources.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 # Copyright (c) 2011 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.
@@ -233,4 +233,3 @@ def Main(argv):
 
 if __name__ == '__main__':
   sys.exit(Main(sys.argv))
-
diff --git a/build/scan_sources_test.py b/build/scan_sources_test.py
index 233d017..0d98030 100755
--- a/build/scan_sources_test.py
+++ b/build/scan_sources_test.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 # Copyright (c) 2011 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.
@@ -89,4 +89,3 @@ Not
 
 if __name__ == '__main__':
   unittest.main()
-