[Bug fortran/29537] ICE in gfc_match_common for blank common in BLOCK DATA unit

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

------- Comment #6 from aldot at gcc dot gnu dot org  2006-10-22 11:50 -------
> I think the code in comment #1 is valid.

Rejecting blank common in block data stmts would add a regression in
testsuite's blockdata_1.f90 like so:
me@s37:~/src/gcc-4.2/gcc/testsuite/gfortran.dg$ gfortran-4.2-HEAD -S -o foo.s
-W -Wall blockdata_1.f90 
 In file blockdata_1.f90:17

 common j
      1
Error: BLOCK DATA unit cannot contain blank COMMON at (1)
 In file blockdata_1.f90:18

 data j /1/
      1
Error: BLOCK DATA element 'j' at (1) must be in COMMON

So rejecting the blank common must be wrong, fwiw :)
--- match.c     (revision 117934)
+++ match.c     (working copy)
@@ -2327,16 +2328,20 @@ gfc_match_common (void)

       if (name[0] == '\0')
        {
+         if (gfc_current_ns->is_block_data)
+           {
+             gfc_error ("BLOCK DATA unit cannot contain blank COMMON at %C");
+             goto cleanup;
+           }
          t = &gfc_current_ns->blank_common;
          if (t->head == NULL)
            t->where = gfc_current_locus;
-         head = &t->head;
        }
       else
        {
          t = gfc_get_common (name, 0);
-         head = &t->head;
        }
+      head = &t->head;

       if (*head == NULL)
        tail = NULL;


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29537