On 09/28/2011 11:02 PM, Paolo Carlini wrote:
Hi,
here submitter remarks that, inconsistently with the documentation,
with -Wextra the C++ front-end doesn't warn for ordered comparison of
pointer with integer zero. Thus I simply adapted the warning in the C
front-end. Is the patch Ok?
Better attaching the patch ;)
Paolo.
/cp
2011-09-28 Paolo Carlini <[email protected]>
PR c++/45278
* typeck.c (cp_build_binary_op): With -Wextra, warn for ordered
comparison of pointer with zero.
/testsuite
2011-09-28 Paolo Carlini <[email protected]>
PR c++/45278
* g++.dg/warn/Wextra-3.C: New.
Index: testsuite/g++.dg/warn/Wextra-3.C
===================================================================
--- testsuite/g++.dg/warn/Wextra-3.C (revision 0)
+++ testsuite/g++.dg/warn/Wextra-3.C (revision 0)
@@ -0,0 +1,9 @@
+// PR c++/45278
+// { dg-options "-Wextra" }
+
+extern void* p;
+
+int f1() { return ( p < 0 ? 1 : 0 ); } // { dg-warning "ordered comparison" }
+int f2() { return ( p <= 0 ? 1 : 0 ); } // { dg-warning "ordered comparison" }
+int f3() { return ( p > 0 ? 1 : 0 ); } // { dg-warning "ordered comparison" }
+int f4() { return ( p >= 0 ? 1 : 0 ); } // { dg-warning "ordered comparison" }
Index: cp/typeck.c
===================================================================
--- cp/typeck.c (revision 179319)
+++ cp/typeck.c (working copy)
@@ -4189,9 +4189,19 @@ cp_build_binary_op (location_t location,
result_type = composite_pointer_type (type0, type1, op0, op1,
CPO_COMPARISON, complain);
else if (code0 == POINTER_TYPE && null_ptr_cst_p (op1))
- result_type = type0;
+ {
+ result_type = type0;
+ if (extra_warnings && (complain & tf_warning))
+ warning (OPT_Wextra,
+ "ordered comparison of pointer with integer zero");
+ }
else if (code1 == POINTER_TYPE && null_ptr_cst_p (op0))
- result_type = type1;
+ {
+ result_type = type1;
+ if (extra_warnings && (complain & tf_warning))
+ warning (OPT_Wextra,
+ "ordered comparison of pointer with integer zero");
+ }
else if (null_ptr_cst_p (op0) && null_ptr_cst_p (op1))
/* One of the operands must be of nullptr_t type. */
result_type = TREE_TYPE (nullptr_node);
