Stream: t-compiler

Topic: LLVM Coverage Mapping (for pgo, code coverage, etc.)


Taylor Cramer (Jan 17 2019 at 02:50, on Zulip):

Has anyone taken a look at adding LLVM Code Coverage Mapping to Rust? I'm looking into it so that we can start getting PGO and code coverage "the right way" for Fuchsia, and was reading https://llvm.org/docs/CoverageMappingFormat.html and https://github.com/llvm/llvm-project/blob/master/clang/lib/CodeGen/CoverageMappingGen.cpp. It doesn't look too terrible, but I wanted to give a heads-up here that this was something I was investigating in case anyone else had looked into doing the same thing and had any advice.

mw (Jan 17 2019 at 10:24, on Zulip):

Awesome! I know that people want to have PGO.
Is this different from how Clang does PGO normally?

nikomatsakis (Jan 17 2019 at 14:09, on Zulip):

I want to be using ccov testing on rustc

nikomatsakis (Jan 17 2019 at 14:09, on Zulip):

I've not looked into it at all

Taylor Cramer (Jan 17 2019 at 17:25, on Zulip):

@mw This is what you get when you use -fprofile-instr-generate / -fcoverage-mapping

Taylor Cramer (Jan 17 2019 at 17:26, on Zulip):

and what llvm-cov works off of

Last update: Nov 22 2019 at 05:35UTC