Issue 642205  has been merged into this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/third_party/toolchain-utils/+/e7a99f8fbd1b94206c3e15d23b88734afb4e64af

commit e7a99f8fbd1b94206c3e15d23b88734afb4e64af
Author: Caroline Tice <cmtice@google.com>
Date: Tue Oct 03 16:43:08 2017

[bisection tool] Fix bisect_driver.py and udpate for host bisection.

This CL udpates bisect_driver.py to consolidate all the various versions
we have into one "source of truth" bisect_driver.py.  It also updates
bisect_driver.py to ignore .o files generated during the 'configure' stage
of Makefile/Autoconf packages (such as GCC & LLVM).  And it adds two
scripts to help with host package bisection.

BUG= chromium:697995 
TEST=Successfully ran unit tests; successfully bisected LLVM inside ChromeOS.

Change-Id: I2e766299dadf9bf3c7de6496f507c863d446d00d
Reviewed-on: https://chromium-review.googlesource.com/696031
Commit-Ready: Caroline Tice <cmtice@chromium.org>
Tested-by: Caroline Tice <cmtice@chromium.org>
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>

[add] https://crrev.com/e7a99f8fbd1b94206c3e15d23b88734afb4e64af/binary_search_tool/sysroot_wrapper/interactive_test_host.sh
[add] https://crrev.com/e7a99f8fbd1b94206c3e15d23b88734afb4e64af/binary_search_tool/sysroot_wrapper/test_setup_host.sh
[modify] https://crrev.com/e7a99f8fbd1b94206c3e15d23b88734afb4e64af/binary_search_tool/README.bisect
[modify] https://crrev.com/e7a99f8fbd1b94206c3e15d23b88734afb4e64af/binary_search_tool/bisect_driver.py

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/6aad0da91a5f589239ca8f4e7bfffc89a0a85c2c

commit 6aad0da91a5f589239ca8f4e7bfffc89a0a85c2c
Author: Caroline Tice <cmtice@google.com>
Date: Tue Oct 10 19:19:08 2017

[gcc & llvm] Clean up compiler use of toolchain bisection tool..

This CL cleans up bisection with LLVM and GCC as follows:

- Adds bisection capabilities to LLVM host wrapper script (making it
  work like as it does in the target compiler wrapper script).
- Makes GCC use the bisect_driver.py in the toolchain-utils directory,
  rather than having it keep its own copy.
- Makes LLVM also use the bisect_driver.py in the toolchain-utils
  directory.
- Updates both of the compiler wrapper scripts to check the return value
  of calls to the bisector.
- Updates the LLVM ebuild file to copy the bisect_driver.py script to
  /usr/bin (so the wrapper script can find & use it).

BUG= chromium:697995 
TEST=Teste  this CL on the following trybot builders:
        nyan_big-release, hana-release, falco-release
     Tested this CL on the chromiumos-sdk trybot builder.
     Built an LLVM host package with & without bisection
     Built a GCC target package (for each arch) w/ & w/o bisection
     Built an LLVM target package (for each arch) w/ & w/o bisection

Change-Id: Iaa15d295e2f6312618fc0cfb3d043b2eebb9643e
Reviewed-on: https://chromium-review.googlesource.com/696182
Commit-Ready: Caroline Tice <cmtice@chromium.org>
Tested-by: Caroline Tice <cmtice@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>

[modify] https://crrev.com/6aad0da91a5f589239ca8f4e7bfffc89a0a85c2c/sys-devel/gcc/gcc-9999.ebuild
[add] https://crrev.com/6aad0da91a5f589239ca8f4e7bfffc89a0a85c2c/sys-devel/llvm/files/bisect_driver.py
[modify] https://crrev.com/6aad0da91a5f589239ca8f4e7bfffc89a0a85c2c/sys-devel/llvm/files/clang_host_wrapper.body
[modify] https://crrev.com/6aad0da91a5f589239ca8f4e7bfffc89a0a85c2c/sys-devel/gcc/files/sysroot_wrapper.hardened.body
[rewrite] https://crrev.com/6aad0da91a5f589239ca8f4e7bfffc89a0a85c2c/sys-devel/gcc/files/bisect_driver.py
[rename] https://crrev.com/6aad0da91a5f589239ca8f4e7bfffc89a0a85c2c/sys-devel/llvm/llvm-5.0_pre305632_p20170806-r5.ebuild