GN: match host and default toolchain + minor cleanups

The major change introduced by this CL is matching
host_toolchain and default_toolchain on pure host builds
(i.e. !android). Today, in fact, when building for
Linux/Mac we still have two toolchains (gcc_like and
gcc_like_host) that happen to have an identical config
(at least in most used configs).
This causes a bunch of subtleties on tools/gen_xxx,
mainy due to the fact of having two targets, both
intended for the host, that happen to use a differently
named toolchain.
This change make it so that when host == target, the host
toolchain is just the default toolchain.
This does not affect chromium / v8 builds.

On top of this, this change makes some minor GN cleanups.

Bug: 140126865
Test: ran tools/gen_all out/mac_debug + full build
Change-Id: I20004c0e23044c64c6dfc10cf50a20875b246c5d
10 files changed
tree: dc540c01c70ab9c4de464dc9abb4537075b4ec9e
  1. build_overrides/
  2. buildtools/
  3. debian/
  4. docs/
  5. gn/
  6. include/
  7. infra/
  8. protos/
  9. src/
  10. test/
  11. tools/
  12. ui/
  13. .clang-format
  14. .gitignore
  15. .gn
  16. Android.bp
  17. Android.bp.extras
  18. BUILD
  19. BUILD.extras
  20. BUILD.gn
  21. codereview.settings
  22. heapprofd.rc
  23. MODULE_LICENSE_APACHE2
  24. NOTICE
  25. OWNERS
  26. perfetto.rc
  27. PRESUBMIT.py
  28. README.chromium
  29. README.md
  30. TEST_MAPPING
README.md

Perfetto - Performance instrumentation and tracing

Perfetto is an open-source project for performance instrumentation and tracing of Linux/Android/Chrome platforms and user-space apps.

See www.perfetto.dev for docs.

Bugs

  • For bugs affecting Android or the tracing internals use the internal bug tracker (go/perfetto-bugs).
  • For bugs affecting Chrome use http://crbug.com, Component:Speed>Tracing label:Perfetto.