ICE on valid with allocatable class component

[Tobias Burnus]

On 08/29/2011 07:37 AM, Andrew Benson wrote:
> The attached code causes an ICE with gfortran 4.7 r178129 - I haven't found
> anything which is obviously this problem reported in bugzilla. Note that if I
> combine the code in the two files into a single file (as in the attached
> combined.F90), and compile that it works without any problem.

That's a regression: I do not get a segfault with GCC 4.6.1 20110801 
(Rev. 177033).

Valgrind shows:

==9734== Invalid read of size 1
==9734==    at 0x6076E8: gfc_sym_type(gfc_symbol*) (trans-types.c:2112)
==9734==    by 0x606BA4: gfc_get_function_type(gfc_symbol*) 
(trans-types.c:2674)
==9734==    by 0x60796A: gfc_get_ppc_type(gfc_component*) 
(trans-types.c:2233)
==9734==    by 0x6065CF: gfc_get_derived_type(gfc_symbol*) 
(trans-types.c:2386)
==9734==    by 0x606A78: gfc_typenode_for_spec(gfc_typespec*) 
(trans-types.c:1056)
==9734==    by 0x607648: gfc_sym_type(gfc_symbol*) (trans-types.c:2052)
==9734==    by 0x5C2F26: gfc_get_symbol_decl(gfc_symbol*) 
(trans-decl.c:1327)
==9734==    by 0x5FF4E3: gfc_trans_allocate(gfc_code*) (trans-stmt.c:5020)


The failure occurs for:
       if (sym->attr.optional || sym->ns->proc_name->attr.entry_master)
         type = build_pointer_type (type);

Hereby:
   (gdb) p sym->name
   $1 = 0x2aaaaab42fc0 "src"
which is of type
   $8 = 0x2aaaaac33e10 "componentbasicstandard"
the problem is:
   (gdb) p sym->ns->proc_name
   $5 = (gfc_symbol *) 0x0


If one looks at the original dump of the combined file, one sees "src" 
only for __copy_g_nodes_Componentbasicstandard and for 
__copy_g_nodes_Gobject; for the former:

__copy_g_nodes_Componentbasicstandard (struct componentbasicstandard & 
restrict src, struct comp
onentbasicstandard & restrict dst)
{
   *dst = *src;
}


For the file containing only the PROGRAM, the line trans-types.c:2112 is 
actually reached three times - every time for sym->name "src". Twice 
sym->ns->proc_name->name is "__copy_g_nodes_Gobject" - and at the third 
time one gets the ICE for proc_name == NULL and ts.u.derived->name == 
"componentbasicstandard".

Tobias