rust-lang/rust

segfault while compiling stage2 libsyntax for i686-pc-windows-gnu

Diggsey opened this issue · 9 comments

Diggsey commented

@alexcrichton has indicated this may be related to using newer versions of gcc, which might explain why it doesn't fail on the buildbot machines.

The segfault occurs while running the tailcallelim llvm pass on ast::Pat_::drop(), possibly during the prerequisite tti analysis.

Turning on any kind of debug information for either rust or llvm causes the problem to disappear.

Diggsey commented

I've reported this as an LLVM bug: https://llvm.org/bugs/show_bug.cgi?id=24722

alexcrichton commented

Closing as a duplicate of #28962

alexcrichton commented

Er actually this has a smaller number, gonna go in favor of this.

alexcrichton commented

Also so this shows up in github search:

gcc 5.2 fails to build LLVM successfully on MinGW as it segfaults at runtime

tkelman commented

This should be fixed in GCC 6, I believe - https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66655

taralx commented

I have indications that GCC 5.3 also works, but I didn't have time to fully test. If someone has a windows box and wants to try it... :)

petrochenkov commented

@taralx
5.3 doesn't work, but this segfault happens only when LLVM assertions are enabled, maybe you tested without them?

taralx commented

I did indeed test without them. Thanks for the heads up.

alexcrichton commented

Testing today, it appears that master branch builds fine with gcc 5.4.0. I suspect we fixed this "by accident" when we updated LLVM at some point