[Bug c++/58591] New: GCC emits bad mangling for template function with a parameter pack

["ccoutant at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58591

            Bug ID: 58591
           Summary: GCC emits bad mangling for template function with a
                    parameter pack
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ccoutant at gcc dot gnu.org

Created attachment 30944
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30944&action=edit
Reduced test case

This is reduced from <bits/stl_construct.h>.

Compiling the attached file with:

  $ g++ -S -std=c++11 mangle-test.cc

Produces the following mangled name for the function Construct:

  _Z9ConstructI1AIiiEEvPT_DpOT0_

This cannot be demangled, because the T0_ reference at the end refers to a
non-existent second template parameter. Removing the whole parameter pack from
the mangling reveals a bogus mangling in the template parameter section:

  $ c++filt _Z9ConstructI1AIiiEEvPT_
  void Construct<A<int, int> >(A<int, int>*)

The type A is not a template -- the two ints together form the parameter pack
that is the second template parameter.