c++/9452: [2003-05-03] ICE (segfault) using a dependent expression as argument for the template-id in the return type

[Wolfgang Bangerth]

> http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=9452
> 
> I think the segfault happens while trying to format the error message.

No, that's not the case. The error happens here (this is present mainline):

#0  convert_from_reference (val=0x40159528)
    at ../../gcc-3.4-CVS/gcc/cp/cvt.c:557
#1  0x08052c35 in prep_operand (operand=0x40159528)
    at ../../gcc-3.4-CVS/gcc/cp/call.c:3561
#2  0x08052f79 in build_new_op (code=MINUS_EXPR, flags=3, arg1=0x40159528, 
    arg2=0x401a0f28, arg3=0x0) at ../../gcc-3.4-CVS/gcc/cp/call.c:3662
#3  0x081143f6 in build_x_binary_op (code=MINUS_EXPR, arg1=0x40159528, 
    arg2=0x0) at ../../gcc-3.4-CVS/gcc/cp/typeck.c:2947
#4  0x0809e635 in tsubst_template_arg_vector (t=0x401a0f50, args=0x40159510, 
    complain=tf_none) at ../../gcc-3.4-CVS/gcc/cp/pt.c:5676
#5  0x0809ed80 in tsubst_aggr_type (t=0x401aabd0, args=0x40159510, 
    complain=tf_none, in_decl=0x0, entering_scope=0)
    at ../../gcc-3.4-CVS/gcc/cp/pt.c:5794
#6  0x080a2d7c in tsubst (t=0x401aac3c, args=0x40159510, complain=tf_none, 
    in_decl=0x0) at ../../gcc-3.4-CVS/gcc/cp/pt.c:6578
#7  0x080a1f34 in tsubst_function_type (t=0x401aac3c, args=0x40159510, 
    complain=tf_none, in_decl=0x401aabd0) at ../../gcc-3.4-CVS/gcc/cp/pt.c:6445
#8  0x080a30e8 in tsubst (t=0x401ad000, args=0x40159510, complain=tf_none, 
    in_decl=0x0) at ../../gcc-3.4-CVS/gcc/cp/pt.c:6960
#9  0x080aedbd in fn_type_unification (fn=0x401ad0d8, explicit_targs=0x0, 
    targs=0x401ad000, args=0x401ac7bc, return_type=0x0, strict=DEDUCE_CALL, 
    len=-1) at ../../gcc-3.4-CVS/gcc/cp/pt.c:8649

The place in convert_reference is this:

tree
convert_from_reference (tree val)
{
  tree type = TREE_TYPE (val);

  if (TREE_CODE (type) == OFFSET_TYPE)           -------- here
    type = TREE_TYPE (type);
  if (TREE_CODE (type) == REFERENCE_TYPE)
    return build_indirect_ref (val, NULL);
  return val;
}

and the reason is that type==0x0. Now, as to why that is happening...

W.

-------------------------------------------------------------------------
Wolfgang Bangerth              email:            bangerth@ices.utexas.edu
                               www: http://www.ices.utexas.edu/~bangerth/