[Bug c++/77427] New: ice when canonical types differ for identical types

["dcb314 at hotmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77427

            Bug ID: 77427
           Summary: ice when canonical types differ for identical types
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

Created attachment 39527
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=39527&action=edit
C++ source code

The attached code, when compiled by g++ trunk dated 20160830, does this:

src/messages.cpp: In function ‘std::__cxx11::string mysprintf(const char*,
...)’
:
src/messages.cpp:64:26: internal compiler error: canonical types differ for
iden
tical types __va_list_tag [1] and __va_list_tag [1]
0x7c521c comptypes(tree_node*, tree_node*, int)
        ../../src/trunk/gcc/cp/typeck.c:1430
0x644c04 reference_related_p(tree_node*, tree_node*)
        ../../src/trunk/gcc/cp/call.c:1415
0x64c3a3 reference_binding
        ../../src/trunk/gcc/cp/call.c:1559
0x64b26c implicit_conversion
        ../../src/trunk/gcc/cp/call.c:1805