tree df4cb2174dadc18e3ca5e16af3c9f5abe6bd9d7d
parent 6c48e4d11ce80fa5cfef56e13b2d5847fe94a7cc
author Brian Osman <brianosman@google.com> 1532029701 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> 1532031805 +0000

Stop using rsp files for compiling on Windows

Chrome stopped using them in January:
https://chromium-review.googlesource.com/c/chromium/src/+/832593

For them, it significantly accelerated goma builds. From my tests,
I think we'll see some small speedup. Note that our older build
system invoked through CMD, which limited us to 8k of command line.
GN/ninja don't do that, so we have the full 32k limit. However,
we do use CMD to do our 32-bit builds... But that doesn't matter,
becase AFAICT the longest command line we generate right now is
only about 2.5k long.

Note that (like Chromium) this continues to use rsp files to link.
Those command lines *can* become ridiculously long.

The original motivation, and a nice benefit of this change:
It makes the output of ninja's compdb tool much more useful.
That tool emits JSON in a standard format describing the commands
used to build each source file. Other tools (eg Visual Studio Code)
can parse that JSON, and deduce the correct defines and include
paths to help with symbol navigation.

Change-Id: I73124f13d5117a0c31445cf6ce1c506d2f73609f
Reviewed-on: https://skia-review.googlesource.com/142584
Reviewed-by: Ben Wagner <benjaminwagner@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>