# Compiler wrapper

See the comments on the top of main.go.
Build is split into 2 steps via separate commands:
- bundle: copies the sources and the `build.py` file into
  a folder.
- build: builds the actual go binary, assuming it is executed
  from the folder created by `bundle.py`.

This allows to copy the sources to a Chrome OS / Android
package, including the build script, and then
build from there without a dependency on toolchain-utils
itself.

## Update Chrome OS

Copy over sources and `build.py` to Chrome OS:
```
(chroot) /mnt/host/source/src/third_party/chromiumos-overlay/sys-devel/llvm/files/update_compiler_wrapper.sh
```

`build.py` is called by these ebuilds:

- third_party/chromiumos-overlay/sys-devel/llvm/llvm-9.0_pre361749_p20190714.ebuild
- third_party/chromiumos-overlay/sys-devel/gcc/gcc-*.ebuild

Generated wrappers are stored here:

- Sysroot wrapper with ccache:
  `/usr/x86_64-pc-linux-gnu/<arch>/gcc-bin/4.9.x/sysroot_wrapper.hardened.ccache`
- Sysroot wrapper without ccache:
  `/usr/x86_64-pc-linux-gnu/<arch>/gcc-bin/4.9.x/sysroot_wrapper.hardened.noccache`
- Clang host wrapper:
  `/usr/bin/clang_host_wrapper`
- Gcc host wrapper:
  `/usr/x86_64-pc-linux-gnu/gcc-bin/4.9.x/host_wrapper`

Copyright 2019 The Chromium OS Authors. All rights reserved.
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file.

Toolchain utils compiler wrapper sources.

Build the wrapper:
./build --config=<config name> --use_ccache=<bool> \
  --use_llvm_next=<bool> --output_file=<file>

ATTENTION:
The files in this folder are generated. Do not modify manually!

To update:
- modify third_party/toolchain_utils/compiler_wrapper
- run third_party/toolchain_utils/compiler_wrapper/bundle.py --output_dir=...

Source: https://chromium-review.googlesource.com/q/{change_id}