Bootstrapped and regression tested on x86_64.
c: Emit -Wzero-as-null-pointer-constant for all integral types [PR117687]
Also warn for boolean, _BitInts, and enumeration constants when
warning for zero as a null pointer constant.
PR c/117687
gcc/c/ChangeLog:
* c-typeck.cc (parser_build_binary_op,build_conditional_expr,
convert_for_assignment): Adapt conditions.
testsuite/ChangeLog:
* gcc.dg/Wzero-as-null-pointer-constant-2.c: New test.
diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
index cab21e29004..3ce536aa946 100644
--- a/gcc/c/c-typeck.cc
+++ b/gcc/c/c-typeck.cc
@@ -5174,14 +5174,14 @@ parser_build_binary_op (location_t location, enum
tree_code code,
{
if ((TREE_CODE (type1) == POINTER_TYPE
|| TREE_CODE (type1) == NULLPTR_TYPE)
- && TREE_CODE (type2) == INTEGER_TYPE
+ && INTEGRAL_TYPE_P (type2)
&& null_pointer_constant_p (arg2.value))
warning_at (arg2.get_location(), OPT_Wzero_as_null_pointer_constant,
"zero as null pointer constant");
if ((TREE_CODE (type2) == POINTER_TYPE
|| TREE_CODE (type2) == NULLPTR_TYPE)
- && TREE_CODE (type1) == INTEGER_TYPE
+ && INTEGRAL_TYPE_P (type1)
&& null_pointer_constant_p (arg1.value))
warning_at (arg1.get_location(), OPT_Wzero_as_null_pointer_constant,
"zero as null pointer constant");
@@ -6524,8 +6524,6 @@ build_conditional_expr (location_t colon_loc, tree ifexp,
bool ifexp_bcp,
{
tree type1;
tree type2;
- enum tree_code code1;
- enum tree_code code2;
tree result_type = NULL;
tree semantic_result_type = NULL;
tree orig_op1 = op1, orig_op2 = op2;
@@ -6558,9 +6556,9 @@ build_conditional_expr (location_t colon_loc, tree ifexp,
bool ifexp_bcp,
tree bltin1 = NULL_TREE;
tree bltin2 = NULL_TREE;
type1 = type_or_builtin_type (op1, &bltin1);
- code1 = TREE_CODE (type1);
+ const enum tree_code code1 = TREE_CODE (type1);
type2 = type_or_builtin_type (op2, &bltin2);
- code2 = TREE_CODE (type2);
+ const enum tree_code code2 = TREE_CODE (type2);
if (code1 == POINTER_TYPE && reject_gcc_builtin (op1))
return error_mark_node;
@@ -6615,12 +6613,12 @@ build_conditional_expr (location_t colon_loc, tree
ifexp, bool ifexp_bcp,
&& c_inhibit_evaluation_warnings == 0)
{
if ((code1 == POINTER_TYPE || code1 == NULLPTR_TYPE)
- && code2 == INTEGER_TYPE && null_pointer_constant_p (orig_op2))
+ && INTEGRAL_TYPE_P (type2) && null_pointer_constant_p (orig_op2))
warning_at (op2_loc, OPT_Wzero_as_null_pointer_constant,
"zero as null pointer constant");
if ((code2 == POINTER_TYPE || code2 == NULLPTR_TYPE)
- && code1 == INTEGER_TYPE && null_pointer_constant_p (orig_op1))
+ && INTEGRAL_TYPE_P (type1) && null_pointer_constant_p (orig_op1))
warning_at (op1_loc, OPT_Wzero_as_null_pointer_constant,
"zero as null pointer constant");
}
@@ -9168,7 +9166,7 @@ convert_for_assignment (location_t location, location_t
expr_loc, tree type,
|| coder == BITINT_TYPE))
{
if (null_pointer_constant && c_inhibit_evaluation_warnings == 0
- && coder == INTEGER_TYPE)
+ && coder != NULLPTR_TYPE)
warning_at (location, OPT_Wzero_as_null_pointer_constant,
"zero as null pointer constant");
/* A NULLPTR type is just a nullptr always. */
diff --git a/gcc/testsuite/gcc.dg/Wzero-as-null-pointer-constant-2.c
b/gcc/testsuite/gcc.dg/Wzero-as-null-pointer-constant-2.c
new file mode 100644
index 00000000000..9b3e1c1a014
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Wzero-as-null-pointer-constant-2.c
@@ -0,0 +1,32 @@
+/* { dg-do compile } */
+/* { dg-options "-std=c23 -Wzero-as-null-pointer-constant" } */
+
+void foo(void*);
+
+void bar()
+{
+ enum { E = 0 };
+ constexpr _BitInt(4) b0 = 0;
+ foo(false); /* { dg-warning "zero as null pointer
constant" } */
+ foo(b0); /* { dg-warning "zero as null pointer
constant" } */
+ foo(E); /* { dg-warning "zero as null pointer
constant" } */
+
+ void *p = false; /* { dg-warning "zero as null pointer
constant" } */
+ void *r = b0; /* { dg-warning "zero as null pointer
constant" } */
+ void *t = E; /* { dg-warning "zero as null pointer
constant" } */
+
+ 1 ? false : p; /* { dg-warning "zero as null pointer
constant" } */
+ 1 ? p : false; /* { dg-warning "zero as null pointer
constant" } */
+ 1 ? b0 : p; /* { dg-warning "zero as null pointer
constant" } */
+ 1 ? p : b0; /* { dg-warning "zero as null pointer
constant" } */
+ 1 ? E : p; /* { dg-warning "zero as null pointer
constant" } */
+ 1 ? p : E; /* { dg-warning "zero as null pointer
constant" } */
+
+ if (p == false); /* { dg-warning "zero as null pointer
constant" } */
+ if (false == p); /* { dg-warning "zero as null pointer
constant" } */
+ if (p == b0); /* { dg-warning "zero as null pointer
constant" } */
+ if (b0 == p); /* { dg-warning "zero as null pointer
constant" } */
+ if (p == E); /* { dg-warning "zero as null pointer
constant" } */
+ if (E == p); /* { dg-warning "zero as null pointer
constant" } */
+}
+
