tools/gn: Convert for loops to use the new range-based loops in C++11.

tools/gn: Convert for loops to use the new range-based loops in C++11.

range-based loops is one of the C++11 allowed features. See
https://chromium-cpp.appspot.com/ and
https://groups.google.com/a/chromium.org/forum/#!topic/chromium-dev/hpzz4EqbVmc.

This patch was generated with the following command lines:

$ ninja -C out/Debug -t compdb cxx > out/Debug/compile_commands.json
$ cd out/Debug
$ find ../../tools/gn -name '*.cc'  | xargs -n 16 -P 32 \
~/src/repos/llvm/build/bin/clang-modernize -loop-convert -p . -include \
tools/gn -format -style=Chromium
$ ninja gn gn_unittests
$ ./gn_unittests

BUG=None
TEST=gn && gn_unittests
R=brettw@chromium.org

Committed: https://crrev.com/b9cf968c8dd857a4f1d583e1bd716f32eede07e4
Cr-Commit-Position: refs/heads/master@{#322177}

[tfarina, 2015-03-08 17:55:01]

Is this OK?

[tfarina, 2015-03-12 21:42:10]

tfarina@chromium.org changed reviewers:
+ scottmg@chromium.org

[tfarina, 2015-03-12 21:42:23]

Scott, could you review this to me?

[scottmg, 2015-03-12 21:54:54]

It looks like a lot of these could be `for (const auto& ...)` rather than just
`for (auto& ...)`.

Do they really need to be non-const?

[tfarina, 2015-03-12 23:21:39]

Done.

[tfarina, 2015-03-13 19:25:56]

Ping?

[scottmg, 2015-03-13 19:58:30]

It looks like there's still a bunch more that could be const?

https://codereview.chromium.org/986113002/diff/60001/tools/gn/escape.cc
File tools/gn/escape.cc (right):

https://codereview.chromium.org/986113002/diff/60001/tools/gn/escape.cc#newco...
tools/gn/escape.cc:47: for (auto& elem : str)
const?

https://codereview.chromium.org/986113002/diff/60001/tools/gn/escape.cc#newco...
tools/gn/escape.cc:55: for (auto& elem : str) {
const?

https://codereview.chromium.org/986113002/diff/60001/tools/gn/escape.cc#newco...
tools/gn/escape.cc:121: for (auto& elem : str) {
const?

https://codereview.chromium.org/986113002/diff/60001/tools/gn/exec_process.cc
File tools/gn/exec_process.cc (right):

https://codereview.chromium.org/986113002/diff/60001/tools/gn/exec_process.cc...
tools/gn/exec_process.cc:197: for (auto& elem : fd_shuffle1)
const?

https://codereview.chromium.org/986113002/diff/60001/tools/gn/generate_test_g...
File tools/gn/generate_test_gn_data.cc (right):

https://codereview.chromium.org/986113002/diff/60001/tools/gn/generate_test_g...
tools/gn/generate_test_gn_data.cc:33: for (auto& elem : repo_path) {
const?

[tfarina, 2015-03-13 23:27:50]

https://codereview.chromium.org/986113002/diff/60001/tools/gn/escape.cc
File tools/gn/escape.cc (right):

https://codereview.chromium.org/986113002/diff/60001/tools/gn/escape.cc#newco...
tools/gn/escape.cc:47: for (auto& elem : str)
On 2015/03/13 19:58:30, scottmg wrote:
> const?

Done.

https://codereview.chromium.org/986113002/diff/60001/tools/gn/escape.cc#newco...
tools/gn/escape.cc:55: for (auto& elem : str) {
On 2015/03/13 19:58:30, scottmg wrote:
> const?

Done.

https://codereview.chromium.org/986113002/diff/60001/tools/gn/escape.cc#newco...
tools/gn/escape.cc:121: for (auto& elem : str) {
On 2015/03/13 19:58:30, scottmg wrote:
> const?

Done.

https://codereview.chromium.org/986113002/diff/60001/tools/gn/exec_process.cc
File tools/gn/exec_process.cc (right):

https://codereview.chromium.org/986113002/diff/60001/tools/gn/exec_process.cc...
tools/gn/exec_process.cc:197: for (auto& elem : fd_shuffle1)
On 2015/03/13 19:58:30, scottmg wrote:
> const?

Done.

https://codereview.chromium.org/986113002/diff/60001/tools/gn/generate_test_g...
File tools/gn/generate_test_gn_data.cc (right):

https://codereview.chromium.org/986113002/diff/60001/tools/gn/generate_test_g...
tools/gn/generate_test_gn_data.cc:33: for (auto& elem : repo_path) {
On 2015/03/13 19:58:30, scottmg wrote:
> const?

Done.

[scottmg, 2015-03-16 16:20:51]

https://codereview.chromium.org/986113002/diff/100001/tools/gn/err.cc
File tools/gn/err.cc (right):

https://codereview.chromium.org/986113002/diff/100001/tools/gn/err.cc#newcode67
tools/gn/err.cc:67: for (auto& range : ranges)
const?

https://codereview.chromium.org/986113002/diff/100001/tools/gn/ninja_build_wr...
File tools/gn/ninja_build_writer.cc (right):

https://codereview.chromium.org/986113002/diff/100001/tools/gn/ninja_build_wr...
tools/gn/ninja_build_writer.cc:196: for (const auto target :
default_toolchain_targets_) {
I don't think this and the one below are correct. Either "const auto&" or
"auto&" when it's necessary to modify the item during the loop.

https://codereview.chromium.org/986113002/diff/100001/tools/gn/ninja_build_wr...
tools/gn/ninja_build_writer.cc:213: for (const auto target :
default_toolchain_targets_) {
here

[tfarina, 2015-03-22 19:59:54]

Sorry for the delay. I was traveling.

PTAL.

https://codereview.chromium.org/986113002/diff/100001/tools/gn/err.cc
File tools/gn/err.cc (right):

https://codereview.chromium.org/986113002/diff/100001/tools/gn/err.cc#newcode67
tools/gn/err.cc:67: for (auto& range : ranges)
On 2015/03/16 16:20:51, scottmg wrote:
> const?

Done.

https://codereview.chromium.org/986113002/diff/100001/tools/gn/ninja_build_wr...
File tools/gn/ninja_build_writer.cc (right):

https://codereview.chromium.org/986113002/diff/100001/tools/gn/ninja_build_wr...
tools/gn/ninja_build_writer.cc:196: for (const auto target :
default_toolchain_targets_) {
On 2015/03/16 16:20:51, scottmg wrote:
> I don't think this and the one below are correct. Either "const auto&" or
> "auto&" when it's necessary to modify the item during the loop.

Done.

https://codereview.chromium.org/986113002/diff/100001/tools/gn/ninja_build_wr...
tools/gn/ninja_build_writer.cc:213: for (const auto target :
default_toolchain_targets_) {
On 2015/03/16 16:20:51, scottmg wrote:
> here

Done.

[scottmg, 2015-03-23 17:24:20]

https://codereview.chromium.org/986113002/diff/120001/tools/gn/ninja_build_wr...
File tools/gn/ninja_build_writer.cc (right):

https://codereview.chromium.org/986113002/diff/120001/tools/gn/ninja_build_wr...
tools/gn/ninja_build_writer.cc:261: for (const auto target :
default_toolchain_targets_) {
const auto&

https://codereview.chromium.org/986113002/diff/120001/tools/gn/ninja_toolchai...
File tools/gn/ninja_toolchain_writer.cc (right):

https://codereview.chromium.org/986113002/diff/120001/tools/gn/ninja_toolchai...
tools/gn/ninja_toolchain_writer.cc:131: for (const auto& target: targets_) {
nit; space before :

https://codereview.chromium.org/986113002/diff/120001/tools/gn/pattern.cc
File tools/gn/pattern.cc (right):

https://codereview.chromium.org/986113002/diff/120001/tools/gn/pattern.cc#new...
tools/gn/pattern.cc:178: for (const auto& pattern: patterns_) {
nit; space before :

[tfarina, 2015-03-25 14:14:32]

https://codereview.chromium.org/986113002/diff/120001/tools/gn/ninja_build_wr...
File tools/gn/ninja_build_writer.cc (right):

https://codereview.chromium.org/986113002/diff/120001/tools/gn/ninja_build_wr...
tools/gn/ninja_build_writer.cc:261: for (const auto target :
default_toolchain_targets_) {
On 2015/03/23 17:24:20, scottmg wrote:
> const auto&

Done.

https://codereview.chromium.org/986113002/diff/120001/tools/gn/ninja_toolchai...
File tools/gn/ninja_toolchain_writer.cc (right):

https://codereview.chromium.org/986113002/diff/120001/tools/gn/ninja_toolchai...
tools/gn/ninja_toolchain_writer.cc:131: for (const auto& target: targets_) {
On 2015/03/23 17:24:20, scottmg wrote:
> nit; space before :

Done.

https://codereview.chromium.org/986113002/diff/120001/tools/gn/pattern.cc
File tools/gn/pattern.cc (right):

https://codereview.chromium.org/986113002/diff/120001/tools/gn/pattern.cc#new...
tools/gn/pattern.cc:178: for (const auto& pattern: patterns_) {
On 2015/03/23 17:24:20, scottmg wrote:
> nit; space before :

Done.

[scottmg, 2015-03-25 16:56:42]

The CQ bit was checked by scottmg@chromium.org

[scottmg, 2015-03-25 16:56:42]

lgtm

[commit-bot: I haz the power, 2015-03-25 16:57:24]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/986113002/140001

[commit-bot: I haz the power, 2015-03-25 17:02:23]

Committed patchset #8 (id:140001)

[commit-bot: I haz the power, 2015-03-25 17:03:30]

Patchset 8 (id:??) landed as
https://crrev.com/b9cf968c8dd857a4f1d583e1bd716f32eede07e4
Cr-Commit-Position: refs/heads/master@{#322177}