[Bug c++/27425] New: [4.0/4.1/4.2 regression] ICE with invalid template-template-parameter

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

The C++ frontend ICEs on the following invalid code snippet since GCC 3.4.0:

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

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

bugB.cc:3: error: 'void' is not a valid type for a template constant parameter
bugB.cc:4: error: 'void' is not a valid type for a template constant parameter
bugB.cc: In instantiation of 'A<0>':
bugB.cc:8:   instantiated from here
bugB.cc:3: error: 'void' is not a valid type for a template constant parameter
bugB.cc:4: error: 'void' is not a valid type for a template constant parameter
bugB.cc:4: error: 'void' is not a valid type for a template constant parameter
bugB.cc:5: internal compiler error: in coerce_template_parms, at cp/pt.c:4042
Please submit a full bug report, [etc.]

With GCC 3.3.3 - 3.3.6 we got sensible error messages.
Before GCC 3.3.3 the compiler entered an infinite loop.


-- 
           Summary: [4.0/4.1/4.2 regression] ICE with invalid template-
                    template-parameter
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Keywords: ice-on-invalid-code, error-recovery, 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=27425