[Bug c/79530] New: GCC segfault when calling weakref+alias functions within __transaction_atomic block

["tdz at users dot sourceforge.net" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79530

            Bug ID: 79530
           Summary: GCC segfault when calling weakref+alias functions
                    within __transaction_atomic block
           Product: gcc
           Version: 6.3.1
            Status: UNCONFIRMED
          Keywords: trans-mem
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: tdz at users dot sourceforge.net
  Target Milestone: ---

Created attachment 40748
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=40748&action=edit
Test case (simply run 'make')

GCC version: gcc (GCC) 6.3.1 20161221 (Red Hat 6.3.1-1)
Linux system: Fedora 24 (x86_64)

STR:

  - call a weakref'ed function alias (__attribute__((weakref, alias(...))))
from within __transaction_atomic{}

Expected result:

  - GCC should generate a call to the target function

Actual result:

  - GCC quits with a segmentation fault:

> main.c: In function 'main':
> main.c:23:1: internal compiler error: Segmentation fault
>  }
>  ^


The attached test case builds and runs if the __transaction_atomic statement
has been removed. The target symbol has to be in a separate object file to
trigger the bug.