It looks like it's just a matter of passing along a name demangler via the -Xdemangler option, as per https://llvm.org/docs/CommandGuide/llvm-cov.html#llvm-cov-show , as part of the line-by-line invocation as part of https://chromium.googlesource.com/chromium/src/+/acb53bd0a13e18d85743f30c83dd560ea1e8f175/tools/code_coverage/coverage.py#510

I'm not sure if just passing llvm-symbolizer was the correct one, but it seems like it would be?

Er, sorry, C++filt

 Issue 842303  has been merged into this issue.

Thanks a lot for the report and for the investigation! C++filt seems to work find on Linux:

$ echo _ZN3net4ntlm16NtlmBufferWriter9WriteUIntIjEEbT_ | c++filt 
bool net::ntlm::NtlmBufferWriter::WriteUInt<unsigned int>(unsigned int)

Should be an easy patch. Do you want to give it a try? :)

Yeah, I had a local patch - my uncertainty was around the cross-platform requirements for the script, since c++filt will only conditionally be available, even on Linux, so it didn't seem a good long term option.

I wasn't sure the cross-platform plans, and whether we'd want to opt for per-platform solutions (similar to //base/debug/stack_trace_*), or whether we were looking at something integrated with llvm (like https://llvm.org/docs/CommandGuide/llvm-symbolizer.html , as used by asan_symbolize.py)

Yes, llvm-symbolizer would be a better choice in a long term, as I think we have it available on all platforms.

But in the meantime, while we are running only Linux bots for the dashboard reports, I wouldn't mind to have something like "if linux: add option -Xdemangler=C++filt"

llvm-symbolizer is the preferred option, even for cross-platform. See _GetPathWithLLVMSymbolizerDir, might need to put that in PATH for llvm-cov.

ah sorry i didn't read Max's comment, c++filt is fine for now for non-win platforms. it works fine on mac too.

Ryan, assigning to you since you have the patch already for this :)

https://chromium-review.googlesource.com/c/chromium/src/+/1060264

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ae19b2c36a367858c631fb533c0e7c1bc8fee677

commit ae19b2c36a367858c631fb533c0e7c1bc8fee677
Author: Ryan Sleevi <rsleevi@chromium.org>
Date: Tue May 15 22:36:17 2018

Run coverage reports through c++filt on Linux and macOS.

The code coverage reports from llvm-cov will emit detailed coverage
information for instantiated templates, but by default, will emit
the method names using their mangled form. llvm-cov allows for
providing a custom demangler.

This conditionally provides custom demangler, using c++filt when
running on Linux and macOS. Longer-term, a solution based on
llvm-symbolizer is more desirable for platform neutrality, but
this helps bridge the short-term need.

BUG= 843246 

Change-Id: I718016b05af0842ac148d06e968f362bc68b5fc8
Reviewed-on: https://chromium-review.googlesource.com/1060264
Commit-Queue: Ryan Sleevi <rsleevi@chromium.org>
Reviewed-by: Abhishek Arya <inferno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558863}
[modify] https://crrev.com/ae19b2c36a367858c631fb533c0e7c1bc8fee677/tools/code_coverage/coverage.py

Code Coverage owners: Would you rather close this and leave the switch to llvm-symbolizer as part of the cross-platform work (is their a bug to star for Windows?), or leave it open to track the remaining xplat stuff?

I think this will come up later anyway (e.g. during issue 809150), so let's close this one. Thanks a lot, Ryan!

Verified, thanks a lot, looks so nice and readable.

https://chromium-coverage.appspot.com/reports/559087/linux/chromium/src/base/numerics/safe_conversions.h.html