re PR c++/43906 (missing warnings the comparison between an address with a null point...

/cp
2014-08-06  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/43906
	* typeck.c (cp_build_binary_op): Extend to more cases the
	-Waddress warning.

/testsuite
2014-08-06  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/43906
	* g++.dg/warn/Waddress-1.C: New.

From-SVN: r213682

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index d9ad73cdbde5413a4be43770855e7ac3aaa86b8a..e4f12b12e2adec9424b0d9631d51653840c12f55 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2014-08-06  Paolo Carlini  <paolo.carlini@oracle.com>
+
+       PR c++/43906
+       * typeck.c (cp_build_binary_op): Extend to more cases the
+       -Waddress warning.
+
 2014-08-01  Braden Obrzut  <admin@maniacsvault.net>
 
        Implement constexpr variable templates

diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index 735cd5860409327f19a74604cbf4847cc70c5aab..353d921131d1c5d1dbc56a08f7054ee2fa07cb26 100644 (file)
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -4353,13 +4353,18 @@ cp_build_binary_op (location_t location,
          && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
              || code1 == COMPLEX_TYPE || code1 == ENUMERAL_TYPE))
        short_compare = 1;
-      else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
-              || (TYPE_PTRDATAMEM_P (type0) && TYPE_PTRDATAMEM_P (type1)))
-       result_type = composite_pointer_type (type0, type1, op0, op1,
-                                             CPO_COMPARISON, complain);
-      else if ((code0 == POINTER_TYPE || TYPE_PTRDATAMEM_P (type0))
-              && null_ptr_cst_p (op1))
-       {
+      else if (((code0 == POINTER_TYPE || TYPE_PTRDATAMEM_P (type0))
+               && null_ptr_cst_p (op1))
+              /* Handle, eg, (void*)0 (c++/43906), and more.  */
+              || (code0 == POINTER_TYPE
+                  && TYPE_PTR_P (type1) && integer_zerop (op1)))
+       {
+         if (TYPE_PTR_P (type1))
+           result_type = composite_pointer_type (type0, type1, op0, op1,
+                                                 CPO_COMPARISON, complain);
+         else
+           result_type = type0;
+
          if (TREE_CODE (op0) == ADDR_EXPR
              && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
            {
@@ -4368,11 +4373,19 @@ cp_build_binary_op (location_t location,
                warning (OPT_Waddress, "the address of %qD will never be NULL",
                         TREE_OPERAND (op0, 0));
            }
-         result_type = type0;
        }
-      else if ((code1 == POINTER_TYPE || TYPE_PTRDATAMEM_P (type1))
-              && null_ptr_cst_p (op0))
+      else if (((code1 == POINTER_TYPE || TYPE_PTRDATAMEM_P (type1))
+               && null_ptr_cst_p (op0))
+              /* Handle, eg, (void*)0 (c++/43906), and more.  */
+              || (code1 == POINTER_TYPE
+                  && TYPE_PTR_P (type0) && integer_zerop (op0)))
        {
+         if (TYPE_PTR_P (type0))
+           result_type = composite_pointer_type (type0, type1, op0, op1,
+                                                 CPO_COMPARISON, complain);
+         else
+           result_type = type1;
+
          if (TREE_CODE (op1) == ADDR_EXPR 
              && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
            {
@@ -4381,8 +4394,11 @@ cp_build_binary_op (location_t location,
                warning (OPT_Waddress, "the address of %qD will never be NULL",
                         TREE_OPERAND (op1, 0));
            }
-         result_type = type1;
        }
+      else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
+              || (TYPE_PTRDATAMEM_P (type0) && TYPE_PTRDATAMEM_P (type1)))
+       result_type = composite_pointer_type (type0, type1, op0, op1,
+                                             CPO_COMPARISON, complain);
       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);

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index ce1003c4e7d1280e027aa7c0405c04683f8c30ba..0c5c386032cdb604fe98f2708181d36c36f279b8 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2014-08-06  Paolo Carlini  <paolo.carlini@oracle.com>
+
+       PR c++/43906
+       * g++.dg/warn/Waddress-1.C: New.
+
 2014-08-06  Maciej W. Rozycki  <macro@codesourcery.com>
 
        * gcc.dg/pr44194-1.c: Remove an extraneous brace.

diff --git a/gcc/testsuite/g++.dg/warn/Waddress-1.C b/gcc/testsuite/g++.dg/warn/Waddress-1.C
new file mode 100644 (file)
index 0000000..8723ac9
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Waddress-1.C
@@ -0,0 +1,50 @@
+// PR c++/43906
+// { dg-options "-Waddress -pedantic" }
+
+extern void z();
+typedef void (*ptrf) ();
+typedef int (*ptrfn) (int);
+int n;
+const int m = 1;
+struct S { };
+struct T : S { };
+struct U;
+S s;
+T t;
+double d;
+
+void f()  { if (z) z(); }               // { dg-warning "address" }
+
+void gl() { if (z != 0) z(); }          // { dg-warning "address" }
+void hl() { if (z != (ptrf)0) z(); }    // { dg-warning "address" }
+void il() { if (z != (void*)0) z(); }   // { dg-warning "address|comparison" }
+void jl() { if (&n != (int*)0) z(); }   // { dg-warning "address" }
+void kl() { if (&m != (int*)0) z(); }   // { dg-warning "address" }
+void ll() { if (&s != (T*)0) z(); }     // { dg-warning "address" }
+void ml() { if (&t != (S*)0) z(); }     // { dg-warning "address" }
+
+void nl() { if (z != (S*)0) z(); }      // { dg-error "comparison" }
+// { dg-warning "address" "" { target *-*-* } 26 }
+void pl() { if (z != (ptrfn)0) z(); }   // { dg-error "comparison" }
+// { dg-warning "address" "" { target *-*-* } 28 }
+void ql() { if (&d != (int*)0) z(); }   // { dg-error "comparison" }
+// { dg-warning "address" "" { target *-*-* } 30 }
+void rl() { if (&s != (U*)0) z(); }     // { dg-error "comparison" }
+// { dg-warning "address" "" { target *-*-* } 32 }
+
+void gr() { if (0 != z) z(); }          // { dg-warning "address" }
+void hr() { if ((ptrf)0 != z) z(); }    // { dg-warning "address" }
+void ir() { if ((void*)0 != z) z(); }   // { dg-warning "address|comparison" }
+void jr() { if ((int*)0 != &n) z(); }   // { dg-warning "address" }
+void kr() { if ((int*)0 != &m) z(); }   // { dg-warning "address" }
+void lr() { if ((T*)0 != &s) z(); }     // { dg-warning "address" }
+void mr() { if ((S*)0 != &t) z(); }     // { dg-warning "address" }
+
+void nr() { if ((S*)0 != z) z(); }      // { dg-error "comparison" }
+// { dg-warning "address" "" { target *-*-* } 43 }
+void pr() { if ((ptrfn)0 != z) z(); }   // { dg-error "comparison" }
+// { dg-warning "address" "" { target *-*-* } 45 }
+void qr() { if ((int*)0 != &d) z(); }   // { dg-error "comparison" }
+// { dg-warning "address" "" { target *-*-* } 47 }
+void rr() { if ((U*)0 != &s) z(); }     // { dg-error "comparison" }
+// { dg-warning "address" "" { target *-*-* } 49 }