[Bug c++/34274] New: [4.3 regression] Broken diagnostic: 'template_template_parm' not supported by dump_decl

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

A broken diagnostic is issued by mainline for the following code snippet:

===============================================================
template<int> struct A
{
  template<template<void> class> struct B {};
};

A<0> a;
===============================================================

bug.cc:3: error: 'void' is not a valid type for a template constant parameter
bug.cc: In instantiation of 'A<0>':
bug.cc:6:   instantiated from here
bug.cc:3: error: type/value mismatch at argument 1 in template parameter list
for 'template<int <anonymous> > template<template<template<<declaration error>
> class<template-parameter-2-1> > template<int <anonymous> >
template<<declaration error> > class<template-parameter-2-1> > struct
A<<anonymous> >::B'
bug.cc:3: error:   expected a template of type 'template<int <anonymous> >
template<<declaration error> > class<template-parameter-2-1>', got
'#'template_template_parm' not supported by dump_decl#<declaration error>'
bug.cc:3: error: type/value mismatch at argument 1 in template parameter list
for 'template<int <anonymous> > template<template<template<<declaration error>
> class<template-parameter-2-1> > template<int <anonymous> >
template<<declaration error> > class<template-parameter-2-1> > struct
A<<anonymous> >::B'
bug.cc:3: error:   expected a template of type 'template<int <anonymous> >
template<<declaration error> > class<template-parameter-2-1>', got
'#'template_template_parm' not supported by dump_decl#<declaration error>'

First, the error message includes:
  'template_template_parm' not supported by dump_decl
Second, the error message is given twice.

Btw, the code triggered an ICE in GCC 4.2.x.


-- 
           Summary: [4.3 regression] Broken diagnostic:
                    'template_template_parm' not supported by dump_decl
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: diagnostic, monitored
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: reichelt at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34274