[LLVMdev] Need help reading the LLVM Buildbot results

[David Blaikie]

On Sat, Nov 10, 2012 at 3:21 AM, Patrik Hägglund H
<patrik.h.hagglund at ericsson.com> wrote:
> From r167602 and onwards I get a fail in 'make check-all' for llvm+clang,
> built with gcc-4.7.1 (but not with clang-3.1) on Linux x86_64:
>
> Failing Tests (1):
>     Clang :: CodeGenCXX/mangle-ms-templates.cpp
>
> clang: /dev/shm/uabpath/master/include/llvm/Support/Casting.h:208: typename
> llvm::cast_retty<To, From>::ret_type llvm::cast(const Y&) [with X =
> clang::TemplateSpecializationType; Y = const clang::Type*; typename
> llvm::cast_retty<To, From>::ret_type = const
> clang::TemplateSpecializationType*]: Assertion `isa<X>(Val) && "cast<Ty>()
> argument of incompatible type!"' failed.

If you take the full command line out of the build log & run it
separately you should be able to reproduce this assert. Depending on
the complexity of the test, you may be able to simply remove the
"-cc1" that's probably in the command line & watch it fail but this
time you'll get a crash report from Clang including the path to a .sh
file containing the command line and a .cpp file containing the
preprocessed source code necessary to reproduce the problem. If you
can file that in a bug we should be able to reproduce & fix it.

> This made me take a look at the LLVM Buildbot pages at
> http://lab.llvm.org:8011/. However, I find it difficult to find useful
> information matching this problem.

Don't worry, you're not the only one. This area could use some
improvement (& there's some amount of work going on in that area)

> * Can I look up results for r167602 (or closely afterwards)? (Can I compare
> it with r167601 or less?)

I don't believe so - I think only a certain sliding window of logs are
kept (& I don't know of an easy way to view a particular revision
across the bots either)

> * How can I see if some buildbot is using gcc-4.7.1 (or later)?

I don't believe so - some bots indicate something of their
purpose/role in the name of the builder, but it's not a well specified
attribute. I suppose we could add something to the builder profile
that causes us to run a version check on the host compiler (but that
would only show up in the build logs at best, not in the builder
description). Anything else I think would be manually maintained
(which might still be worthwhile)

> * There seems to be quite a few failed builds in the buildbots. Which
> buildbot configurations should I expect to be maintained to produce mostly
> non-failed builds?

Unclear - generally you can look at the finite history shown on the
buildbot console page & if a bot's been red for that entire time it's
probably about worth ignoring (until someone takes the time to clean
it up). We should move the dead buildbots aside until someone revives
them, rather than leaving them there adding noise to the page.

> * Is there some general introduction document for reading the LLVM Buildbot
> results?

Not that I know of.