[LLVMdev] asan coverage

[Kostya Serebryany]

On Fri, Nov 15, 2013 at 7:26 AM, Bob Wilson <bob.wilson at apple.com> wrote:
> Hi Kostya,
>
> Thanks for the heads-up on this.  I haven’t had a chance to look into the
> details yet, but it looks like these patches may be breaking our
> bootstrapped LTO build.  Our buildbots have been failing all day, and we’re
> still trying to figure out the problem.  I’m going to speculatively revert
> those changes, since they were the only patches on the buildbot blame list.
> I will either reapply the changes or help debug the problem.

How could this possibly affect your LTO build?
The option is off by default.
Do you have any details, logs, etc?

>
> —Bob
>
> On Nov 14, 2013, at 5:42 AM, Kostya Serebryany <kcc at google.com> wrote:
>
> Bob, Justin,
>
> I've just committed a poor man's coverage implementation that works with
> asan.
> http://llvm.org/viewvc/llvm-project?rev=194701&view=rev
> http://llvm.org/viewvc/llvm-project?rev=194702&view=rev
> It provides only function-level boolean coverage (i.e. no counters, just
> "visited or not"),
> but is very fast and very simple (no extra sections to the binary file, etc)
> I've tried it for Chrome's content_shell (huge and heavy binary) and the
> overhead
> is negligible at both run-time and shutdown-time.
>
> We'll be evaluating this implementation and collecting usage stats.
> Maybe we want to implement something simple like this in the Clang coverage.
>
> --kcc
>
>