v811_spc009/external/toolchain-utils/compiler_wrapper

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.

Testing Inside the Chroot

To test updates to the wrapper locally:

Run install_compiler_wrapper.sh to install the new wrapper in the chroot:

(chroot) ~/trunk/src/third_party/toolchain-utils/compiler_wrapper/install_compiler_wrapper.sh

Then perform the tests, e.g. build with the new compiler.

Updating the Wrapper for Chrome OS

To update the wrapper for everyone, the new wrapper configuration must be copied into chromiumos-overlay, and new revisions of the gcc and llvm ebuilds must be created.

Copy over sources and build.py to chromiumos-overlay:

(chroot) /mnt/host/source/src/third_party/chromiumos-overlay/sys-devel/llvm/files/update_compiler_wrapper.sh

Rename chromiumos-overlay/sys-devel/llvm/llvm-${VERSION}.ebuild to the next revision number. For example, if the current version is 11.0_pre394483_p20200618-r2:

(chroot) cd ~/trunk/src/third_party/chromiumos-overlay
(chroot) git mv llvm-11.0_pre394483_p20200618-r2.ebuild llvm-11.0_pre394483_p20200618-r3.ebuild

Rename chromiumos-overlay/sys-devel/gcc/gcc-${VERSION}.ebuild to the next revision number. For example, if the current version is 4.9.2-r254:

(chroot) cd ~/trunk/src/third_party/chromiumos-overlay
(chroot) git mv sys-devel/gcc/gcc-4.9.2-r254.ebuild sys-devel/gcc/gcc-4.9.2-r255.ebuild

Edit the new ebuild file and change the number at the end to match the new revision:

-# If you need to force a cros_workon uprev, change this number (you can use next
-# uprev): 254
+# If you need to force a cros_workon uprev, change this number (you can use next
+# uprev): 255

Commit those changes together with the changes made by update_compiler_wrapper.sh.

The changes can then be reviewed and submitted through the normal process.

Paths

build.py is called by these ebuilds:

• third_party/chromiumos-overlay/sys-devel/llvm/llvm-*.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