if __has_include(X) returns true then X is an input

Typically __has_include is used to check if a header is available
before #include'ing it.  But in some cases __has_include is only
used as feature detection, without a subsequent #include (a real
world example is in boost's libstdcpp3.hpp).  In this case, the
goma client won't upload the file that __has_include found, and
the remote job will fail this check that succeeded locally.

What we should do add X to the list of input files if __has_include(X)
evaluates to true, but without processing X for further includes.

(And similarly for __has_include_next.)

Change-Id: Ibb77ac0691698fc965455973d7f86eb35dc646ca
3 files changed
tree: 0c2d87a5836b2df43d9d34aa06a25035fb3ffcf9
  1. base/
  2. benchmark/
  3. build/
  4. buildtools/
  5. client/
  6. infra/
  7. lib/
  8. test/
  9. testing/
  10. third_party/
  11. tools/
  12. .clang-format
  13. .gitignore
  14. .gn
  15. BUILD.gn
  16. codereview.settings
  17. CONTRIBUTING.md
  18. DEPS
  19. LICENSE
  20. OWNERS
  21. PRESUBMIT.py
  22. README.md
README.md

Goma

Goma is a distributed compiler service for open-source project such as Chromium and Android. It's some kind of replacement of distcc+ccache.

NOTE: currently the goma backend is not available for non googlers. We're working so that chromium developers can use it. Stay tuned.

How goma works

Goma hooks a compile request, and sends it to a backend compile server. If you have plenty of backend servers, a lot of compile can be processed in parallel, for example, -j100, -j500 or -j1000.

Also, the goma backend caches the compile result. If the same compile request comes, the cached result is returned from the goma cache server.

How to build

goma client can be built on Linux, Mac, and Win.

Install dependencies

  1. Install depot_tools.
  2. Install dependencies.

On debian or ubuntu,

$ sudo apt-get install libssl-dev libc6-dev-i386

On Mac, install Xcode.

On Windows, install Visual Studio 2017. Community edition is OK.

Checkout source

$ gclient config https://chromium.googlesource.com/infra/goma/client
$ gclient sync
$ cd client

We assume goma is checked out to $GOMA_SRC.

Build

$ cd "$GOMA_SRC/client"
$ gclient sync
$ gn gen --args='is_debug=false' out/Release
$ ninja -C out/Release

Several important gn args

The build option can be modified with gn args.

is_debug=true/false
  Do debug build if true.
dcheck_always_on=true/false
  Enable DCHECK always (even in release build).
is_asan=true/false
  Use ASan build (with clang).
use_link_time_optimization=true/false
  Currently working only on Win. If true, /LTCG is enable.
use_lld=true/false
  Use lld for link (it will be fast)

Run unittest

$ cd "$GOMA_SRC/client"
$ ./build/run_unittest.py --target=Release --build-dir=out

How to use

For Chromium/Android development

Goma can be integrated with Chromium/Android development easily.

  1. Build goma client
  2. Start compiler_proxy
$ "$GOMA_SRC/client/out/Release/goma_ctl.py" start

For Chromium

In Chromium src, specify the following args in gn args

use_goma = true
goma_dir = "$GOMA_SRC/client/out/Release"  (Replace $GOMA_SRC to your checkout)

Then build like the following:

$ cd /path/to/chromium/src/out/Release
$ ninja -j100 chrome

For Android

$ source build/envsetup.sh
$ lunch aosp_arm-eng
$ GOMA_DIR=$GOMA_SRC/client/out/Release USE_GOMA=true make -j4

Here, -j4 is not related to goma parallelism. Android internally sets -j500 (or -j with NINJA_REMOTE_NUM_JOBS environment variable) for goma.

For general development

  1. Build goma client
  2. Start compiler_proxy
$ ./goma_ctl.py ensure_start
  1. Change your build script so that gomacc is prepended to compiler command. For example:
$ gomacc clang++ -c foo.cc
  1. Build your product with make -j100, ninja -j100 or larger -j. Check http://localhost:8080 to see compiler_proxy is actually working.

Tips

  • You can use autoninja in depot_tools instead of specifying gomacc manually.