[Bug fortran/40873] -fwhole-file -fwhole-program: Wrong decls cause too much to be optimized away

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

------- Comment #25 from burnus at gcc dot gnu dot org  2010-07-26 17:03 -------
(In reply to comment #23)
> Created an attachment (id=21315)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=21315&action=view) [edit]
> New trans-decl.c patch - seems to work well

Dominique has found a failure (segfault) with PR 31867 comment 6.

If one generates in gfc_get_extern_function_decl the code for "lensum", one
finds that its argument "words" has locally the correct type:
  (gdb) p sym->formal->sym->as->type
  $4 = AS_ASSUMED_SHAPE
but the gsym has the wrong type
  (gdb) p gsym->ns->proc_name->formal->sym->as->type
  $10 = AS_DEFERRED
Thus, one enters the code path for descriptor-free arrays and crashes as UBOUND
is NULL.

In principle, this should get fixed in resolve_formal_arglist. One problem is
that if one enters find_arglists sym->ns != gfc_current_ns it fails.

But the actual problems seems to be in resolve_global_procedure. One has:

(gdb) p sym->attr.if_source
$27 = IFSRC_IFBODY
(gdb) p sym->formal->sym->as->type
$28 = AS_ASSUMED_SHAPE

That is: The symbol in the interface block of the module is resolved. But the
gsym is not:

(gdb) p gsym->ns->resolved
$29 = 0
(gdb) p gsym->ns->proc_name->formal->sym->as->type
$30 = AS_DEFERRED

The following patch fixes the program. (Side remark, one could do more argument
checking, cf. PR 45086.)

Index: gcc/fortran/resolve.c
===================================================================
--- gcc/fortran/resolve.c       (revision 162538)
+++ gcc/fortran/resolve.c       (working copy)
@@ -1816,7 +1816,8 @@ resolve_global_procedure (gfc_symbol *sy
     gfc_global_used (gsym, where);

   if (gfc_option.flag_whole_file
-       && sym->attr.if_source == IFSRC_UNKNOWN
+       && (sym->attr.if_source == IFSRC_UNKNOWN
+           || sym->attr.if_source == IFSRC_IFBODY)
        && gsym->type != GSYM_UNKNOWN
        && gsym->ns
        && gsym->ns->resolved != -1
@@ -1902,7 +1903,7 @@ resolve_global_procedure (gfc_symbol *sy
                   sym->name, &sym->declared_at, gfc_typename (&sym->ts),
                   gfc_typename (&def_sym->ts));

-      if (def_sym->formal)
+      if (def_sym->formal && sym->attr.if_source != IFSRC_IFBODY)
        {
          gfc_formal_arglist *arg = def_sym->formal;
          for ( ; arg; arg = arg->next)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40873