[Bug fortran/57360] Implement a warning for implied save

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57360

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kargl at gcc dot gnu.org

--- Comment #6 from kargl at gcc dot gnu.org ---
With this patch, 

diff --git a/gcc/fortran/decl.cc b/gcc/fortran/decl.cc
index 503ecb8d9b5..abb3579893f 100644
--- a/gcc/fortran/decl.cc
+++ b/gcc/fortran/decl.cc
@@ -2278,7 +2278,12 @@ add_init_expr_to_sym (const char *name, gfc_expr
**initp, locus *var_locus)

       sym->value = init;
       if (sym->attr.save == SAVE_NONE)
-       sym->attr.save = SAVE_IMPLICIT;
+       {
+         sym->attr.save = SAVE_IMPLICIT;
+         if (warn_surprising)
+           gfc_warning (OPT_Wsurprising, "Entity %qs at %L has an implicit "
+                     "SAVE attribute", sym->name, &sym->declared_at);
+       }
       *initp = NULL;
     }

I see

% gfcx -o z a.f90 -Wsurprising && ./z
a.f90:2:13:

    2 |  integer :: i=1
      |             1
Warning: Entity ‘i’ at (1) has an implicit SAVE attribute [-Wsurprising]
           1