[Bug fortran/103259] [11/12 Regression] ICE in resolve_common_vars, at fortran/resolve.c:956

[kargl at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103259

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
                 CC|                            |kargl at gcc dot gnu.org
           Priority|P3                          |P4
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2021-11-15

--- Comment #1 from kargl at gcc dot gnu.org ---
Avoid a NULL pointer dereference.

diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c
index 705d2326a29..b0777e27512 100644
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -953,9 +953,15 @@ resolve_common_vars (gfc_common_head *common_block, bool
named_common)
     {
       gsym = gfc_find_gsymbol (gfc_gsym_root, csym->name);
       if (gsym && (gsym->type == GSYM_MODULE || gsym->type == GSYM_PROGRAM))
-       gfc_error_now ("Global entity %qs at %L cannot appear in a "
-                       "COMMON block at %L", gsym->name,
-                       &gsym->where, &csym->common_block->where);
+       {
+         if (csym->common_block)
+           gfc_error_now ("Global entity %qs at %L cannot appear in a "
+                          "COMMON block at %L", gsym->name, &gsym->where,
+                          &csym->common_block->where);
+         else
+           gfc_error_now ("Global entity %qs at %L cannot appear in a "
+                          "COMMON block", gsym->name, &gsym->where);
+       }

       /* gfc_add_in_common may have been called before, but the reported
errors
         have been ignored to continue parsing.