re PR c++/70194 (missing -Waddress on constexpr pointer)

	PR c++/70194
	* typeck.c (warn_for_null_address): New function.
	(cp_build_binary_op): Call it.

	* g++.dg/warn/constexpr-70194.C: New test.

From-SVN: r234281

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index ac7387846feeefb2e8391b3b6c1334c768674be4..224e3fc5efd3fdb9228e6a943d250e54409cb52a 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2016-03-17  Marek Polacek  <polacek@redhat.com>
+
+       PR c++/70194
+       * typeck.c (warn_for_null_address): New function.
+       (cp_build_binary_op): Call it.
+
 2016-03-16  Jason Merrill  <jason@redhat.com>
 
        PR c++/70259

diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index 20f0afc74d7a5691e267647e1d8cd6e8d5caa7fb..447006cb327456b87bdfcb092d131cd85ed2e276 100644 (file)
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -3974,6 +3974,38 @@ build_vec_cmp (tree_code code, tree type,
   return build3 (VEC_COND_EXPR, type, cmp, minus_one_vec, zero_vec);
 }
 
+/* Possibly warn about an address never being NULL.  */
+
+static void
+warn_for_null_address (location_t location, tree op, tsubst_flags_t complain)
+{
+  if (!warn_address
+      || (complain & tf_warning) == 0
+      || c_inhibit_evaluation_warnings != 0
+      || TREE_NO_WARNING (op))
+    return;
+
+  tree cop = fold_non_dependent_expr (op);
+
+  if (TREE_CODE (cop) == ADDR_EXPR
+      && decl_with_nonnull_addr_p (TREE_OPERAND (cop, 0))
+      && !TREE_NO_WARNING (cop))
+    warning_at (location, OPT_Waddress, "the address of %qD will never "
+               "be NULL", TREE_OPERAND (cop, 0));
+
+  if (CONVERT_EXPR_P (op)
+      && TREE_CODE (TREE_TYPE (TREE_OPERAND (op, 0))) == REFERENCE_TYPE)
+    {
+      tree inner_op = op;
+      STRIP_NOPS (inner_op);
+
+      if (DECL_P (inner_op))
+       warning_at (location, OPT_Waddress,
+                   "the compiler can assume that the address of "
+                   "%qD will never be NULL", inner_op);
+    }
+}
+
 /* Build a binary-operation expression without default conversions.
    CODE is the kind of expression to build.
    LOCATION is the location_t of the operator in the source code.
@@ -4520,32 +4552,7 @@ cp_build_binary_op (location_t location,
          else
            result_type = type0;
 
-         if (TREE_CODE (op0) == ADDR_EXPR
-             && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
-           {
-             if ((complain & tf_warning)
-                 && c_inhibit_evaluation_warnings == 0
-                 && !TREE_NO_WARNING (op0))
-               warning (OPT_Waddress, "the address of %qD will never be NULL",
-                        TREE_OPERAND (op0, 0));
-           }
-
-         if (CONVERT_EXPR_P (op0)
-             && TREE_CODE (TREE_TYPE (TREE_OPERAND (op0, 0)))
-                == REFERENCE_TYPE)
-           {
-             tree inner_op0 = op0;
-             STRIP_NOPS (inner_op0);
-
-             if ((complain & tf_warning)
-                 && c_inhibit_evaluation_warnings == 0
-                 && !TREE_NO_WARNING (op0)
-                 && DECL_P (inner_op0))
-               warning_at (location, OPT_Waddress,
-                           "the compiler can assume that the address of "
-                           "%qD will never be NULL",
-                           inner_op0);
-           }
+         warn_for_null_address (location, op0, complain);
        }
       else if (((code1 == POINTER_TYPE || TYPE_PTRDATAMEM_P (type1))
                && null_ptr_cst_p (op0))
@@ -4559,32 +4566,7 @@ cp_build_binary_op (location_t location,
          else
            result_type = type1;
 
-         if (TREE_CODE (op1) == ADDR_EXPR 
-             && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
-           {
-             if ((complain & tf_warning)
-                 && c_inhibit_evaluation_warnings == 0
-                 && !TREE_NO_WARNING (op1))
-               warning (OPT_Waddress, "the address of %qD will never be NULL",
-                        TREE_OPERAND (op1, 0));
-           }
-
-         if (CONVERT_EXPR_P (op1)
-             && TREE_CODE (TREE_TYPE (TREE_OPERAND (op1, 0)))
-                == REFERENCE_TYPE)
-           {
-             tree inner_op1 = op1;
-             STRIP_NOPS (inner_op1);
-
-             if ((complain & tf_warning)
-                 && c_inhibit_evaluation_warnings == 0
-                 && !TREE_NO_WARNING (op1)
-                 && DECL_P (inner_op1))
-               warning_at (location, OPT_Waddress,
-                           "the compiler can assume that the address of "
-                           "%qD will never be NULL",
-                           inner_op1);
-           }
+         warn_for_null_address (location, op1, complain);
        }
       else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
               || (TYPE_PTRDATAMEM_P (type0) && TYPE_PTRDATAMEM_P (type1)))

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index f59e1c8213d5d0da971c5d0f14a63af3c327afc5..e27a4e178203cea076d7ef2bd696171584c49b13 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-03-17  Marek Polacek  <polacek@redhat.com>
+
+       PR c++/70194
+       * g++.dg/warn/constexpr-70194.C: New test.
+
 2016-03-16  Richard Henderson  <rth@redhat.com>
 
        PR middle-end/70240

diff --git a/gcc/testsuite/g++.dg/warn/constexpr-70194.C b/gcc/testsuite/g++.dg/warn/constexpr-70194.C
new file mode 100644 (file)
index 0000000..cdc56c0
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/constexpr-70194.C
@@ -0,0 +1,12 @@
+// PR c++/70194
+// { dg-do compile { target c++11 } }
+// { dg-options "-Wall" }
+
+int i;
+
+const bool b0 = &i == 0; // { dg-warning "the address of .i. will never be NULL" }
+constexpr int *p = &i;
+const bool b1 = p == 0; // { dg-warning "the address of .i. will never be NULL" }
+const bool b2 = 0 == p; // { dg-warning "the address of .i. will never be NULL" }
+const bool b3 = p != 0; // { dg-warning "the address of .i. will never be NULL" }
+const bool b4 = 0 != p; // { dg-warning "the address of .i. will never be NULL" }