[Bug c++/33738] -Wtype-limits misses a warning when comparing enums

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

------- Comment #5 from manu at gcc dot gnu dot org  2008-02-05 11:21 -------
You should use OPT_Wtype_limits instead of OPT_Wextra.

Also, the code could simply do:

+      tree op0 = TREE_OPERAND (cond, 0);
+      tree op1 = TREE_OPERAND (cond, 1);
+      tree type = TREE_TYPE (op0);
+      value_range_t *vr0 = get_value_range (op0);
+
+      if (vr0->type != VR_VARYING
+         && INTEGRAL_TYPE_P (type)
+         && vrp_val_is_min (vr0->min)
+         && vrp_val_is_max (vr0->max)
+         && is_gimple_min_invariant (op1))
+       {
+         location_t locus;
+         const char *warnmsg = NULL;
+
+         if (!EXPR_HAS_LOCATION (stmt))
+           locus = input_location;
+         else
+           locus = EXPR_LOCATION (stmt);
+
+         if (integer_zerop (ret))
+           warnmsg = G_("comparison always false due to limited range of "
+                        "data type");
+         else
+           warnmsg = G_("comparison always true due to limited range of "
+                        "data type");
+
+         warning (OPT_Wextra, "%H%s", &locus, warnmsg);
+       }


And BTW, what is G_ for?


-- 

manu at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2007-11-13 04:55:56         |2008-02-05 11:21:26
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33738