@@ -324,8 +324,10 @@ static bool nonnull_check_p (tree, unsigned HOST_WIDE_INT);
if they match the mask.
Masks for languages:
- C --std=c89: D_C99 | D_CXXONLY | D_OBJC | D_CXX_OBJC
- C --std=c99: D_CXXONLY | D_OBJC
+ C --std=c89: D_C99 | D_C2X | D_CXXONLY | D_OBJC | D_CXX_OBJC
+ C --std=c99: D_C2X | D_CXXONLY | D_OBJC
+ C --std=c17: D_C2X | D_CXXONLY | D_OBJC
+ C --std=c2x: D_CXXONLY | D_OBJC
ObjC is like C except that D_OBJC and D_CXX_OBJC are not set
C++ --std=c++98: D_CONLY | D_CXX11 | D_CXX20 | D_OBJC
C++ --std=c++11: D_CONLY | D_CXX20 | D_OBJC
@@ -500,7 +502,7 @@ const struct c_common_resword c_common_reswords[] =
{ "namespace", RID_NAMESPACE, D_CXXONLY | D_CXXWARN },
{ "new", RID_NEW, D_CXXONLY | D_CXXWARN },
{ "noexcept", RID_NOEXCEPT, D_CXXONLY | D_CXX11 | D_CXXWARN },
- { "nullptr", RID_NULLPTR, D_CXXONLY | D_CXX11 | D_CXXWARN },
+ { "nullptr", RID_NULLPTR, D_C2X | D_CXX11 | D_CXXWARN },
{ "operator", RID_OPERATOR, D_CXXONLY | D_CXXWARN },
{ "private", RID_PRIVATE, D_CXX_OBJC | D_CXXWARN },
{ "protected", RID_PROTECTED, D_CXX_OBJC | D_CXXWARN },
@@ -4723,6 +4725,18 @@ c_common_nodes_and_builtins (void)
null_node = make_int_cst (1, 1);
TREE_TYPE (null_node) = c_common_type_for_size (POINTER_SIZE, 0);
+ /* Create the built-in nullptr node. This part of its initialization is
+ common to C and C++. The front ends can further adjust its definition
+ in {c,cxx}_init_decl_processing. In particular, we aren't setting the
+ alignment here for C++ backward ABI bug compatibility. */
+ nullptr_type_node = make_node (NULLPTR_TYPE);
+ TYPE_SIZE (nullptr_type_node) = bitsize_int (GET_MODE_BITSIZE (ptr_mode));
+ TYPE_SIZE_UNIT (nullptr_type_node) = size_int (GET_MODE_SIZE (ptr_mode));
+ TYPE_UNSIGNED (nullptr_type_node) = 1;
+ TYPE_PRECISION (nullptr_type_node) = GET_MODE_BITSIZE (ptr_mode);
+ SET_TYPE_MODE (nullptr_type_node, ptr_mode);
+ nullptr_node = build_int_cst (nullptr_type_node, 0);
+
/* Since builtin_types isn't gc'ed, don't export these nodes. */
memset (builtin_types, 0, sizeof (builtin_types));
}
@@ -375,6 +375,8 @@ enum c_tree_index
CTI_DEFAULT_FUNCTION_TYPE,
CTI_NULL,
+ CTI_NULLPTR,
+ CTI_NULLPTR_TYPE,
/* These are not types, but we have to look them up all the time. */
CTI_FUNCTION_NAME_DECL,
@@ -409,7 +411,7 @@ struct c_common_resword
{
const char *const word;
ENUM_BITFIELD(rid) const rid : 16;
- const unsigned int disable : 16;
+ const unsigned int disable : 32;
};
/* Mode used to build pointers (VOIDmode means ptr_mode). */
@@ -447,19 +449,20 @@ extern machine_mode c_default_pointer_mode;
#define D_CONLY 0x0001 /* C only (not in C++). */
#define D_CXXONLY 0x0002 /* C++ only (not in C). */
#define D_C99 0x0004 /* In C, C99 only. */
-#define D_CXX11 0x0008 /* In C++, C++11 only. */
-#define D_EXT 0x0010 /* GCC extension. */
-#define D_EXT89 0x0020 /* GCC extension incorporated in C99. */
-#define D_ASM 0x0040 /* Disabled by -fno-asm. */
-#define D_OBJC 0x0080 /* In Objective C and neither C nor C++. */
-#define D_CXX_OBJC 0x0100 /* In Objective C, and C++, but not C. */
-#define D_CXXWARN 0x0200 /* In C warn with -Wcxx-compat. */
-#define D_CXX_CONCEPTS 0x0400 /* In C++, only with concepts. */
-#define D_TRANSMEM 0X0800 /* C++ transactional memory TS. */
-#define D_CXX_CHAR8_T 0X1000 /* In C++, only with -fchar8_t. */
-#define D_CXX20 0x2000 /* In C++, C++20 only. */
-#define D_CXX_COROUTINES 0x4000 /* In C++, only with coroutines. */
-#define D_CXX_MODULES 0x8000 /* In C++, only with modules. */
+#define D_C2X 0x0008 /* In C, C2X only. */
+#define D_CXX11 0x0010 /* In C++, C++11 only. */
+#define D_EXT 0x0020 /* GCC extension. */
+#define D_EXT89 0x0040 /* GCC extension incorporated in C99. */
+#define D_ASM 0x0080 /* Disabled by -fno-asm. */
+#define D_OBJC 0x0100 /* In Objective C and neither C nor C++. */
+#define D_CXX_OBJC 0x0200 /* In Objective C, and C++, but not C. */
+#define D_CXXWARN 0x0400 /* In C warn with -Wcxx-compat. */
+#define D_CXX_CONCEPTS 0x0800 /* In C++, only with concepts. */
+#define D_TRANSMEM 0x1000 /* C++ transactional memory TS. */
+#define D_CXX_CHAR8_T 0x2000 /* In C++, only with -fchar8_t. */
+#define D_CXX20 0x4000 /* In C++, C++20 only. */
+#define D_CXX_COROUTINES 0x8000 /* In C++, only with coroutines. */
+#define D_CXX_MODULES 0x10000 /* In C++, only with modules. */
#define D_CXX_CONCEPTS_FLAGS D_CXXONLY | D_CXX_CONCEPTS
#define D_CXX_CHAR8_T_FLAGS D_CXXONLY | D_CXX_CHAR8_T
@@ -534,6 +537,9 @@ extern const unsigned int num_c_common_reswords;
/* The node for C++ `__null'. */
#define null_node c_global_trees[CTI_NULL]
+/* The nodes for `nullptr'. */
+#define nullptr_node c_global_trees[CTI_NULLPTR]
+#define nullptr_type_node c_global_trees[CTI_NULLPTR_TYPE]
extern GTY(()) tree c_global_trees[CTI_MAX];
@@ -1009,6 +1015,9 @@ extern void c_parse_final_cleanups (void);
#define DECL_UNNAMED_BIT_FIELD(NODE) \
(DECL_C_BIT_FIELD (NODE) && !DECL_NAME (NODE))
+/* True iff TYPE is cv decltype(nullptr). */
+#define NULLPTR_TYPE_P(TYPE) (TREE_CODE (TYPE) == NULLPTR_TYPE)
+
extern tree do_case (location_t, tree, tree);
extern tree build_stmt (location_t, enum tree_code, ...);
extern tree build_real_imag_expr (location_t, enum tree_code, tree);
@@ -321,6 +321,7 @@ pp_c_pointer (c_pretty_printer *pp, tree t)
_Bool -- C99
_Complex -- C99
_Imaginary -- C99
+ nullptr_t -- C23
struct-or-union-specifier
enum-specifier
typedef-name.
@@ -424,6 +425,9 @@ c_pretty_printer::simple_type_specifier (tree t)
else
translate_string ("<anonymous>");
break;
+ case NULLPTR_TYPE:
+ pp_c_ws_string (this, "nullptr_t");
+ break;
default:
pp_unsupported_tree (this, t);
@@ -678,6 +682,7 @@ c_pretty_printer::direct_abstract_declarator (tree t)
case COMPLEX_TYPE:
case TYPE_DECL:
case ERROR_MARK:
+ case NULLPTR_TYPE:
break;
default:
@@ -1219,6 +1224,8 @@ c_pretty_printer::constant (tree e)
pp_c_character_constant (this, e);
else if (TREE_CODE (type) == ENUMERAL_TYPE)
pp_c_enumeration_constant (this, e);
+ else if (NULLPTR_TYPE_P (type))
+ pp_string (this, "nullptr");
else
pp_c_integer_constant (this, e);
}
@@ -133,6 +133,20 @@ c_convert (tree type, tree expr, bool init_const)
(loc, type, c_objc_common_truthvalue_conversion (input_location, expr));
case POINTER_TYPE:
+ /* The type nullptr_t may be converted to a pointer type. The result is
+ a null pointer value. */
+ if (NULLPTR_TYPE_P (TREE_TYPE (e)))
+ {
+ /* To make sure that (void *)nullptr is not a null pointer constant,
+ build_c_cast will create an additional NOP_EXPR around the result
+ of this conversion. */
+ if (TREE_SIDE_EFFECTS (e))
+ ret = build2 (COMPOUND_EXPR, type, e, build_int_cst (type, 0));
+ else
+ ret = build_int_cst (type, 0);
+ goto maybe_fold;
+ }
+ gcc_fallthrough ();
case REFERENCE_TYPE:
ret = convert_to_pointer (type, e);
goto maybe_fold;
@@ -180,7 +194,16 @@ c_convert (tree type, tree expr, bool init_const)
return ret;
}
- error ("conversion to non-scalar type requested");
+ /* If we are converting to nullptr_t, don't say "non-scalar type" because
+ the nullptr_t type is a scalar type. Only nullptr_t shall be converted
+ to nullptr_t. */
+ if (code == NULLPTR_TYPE)
+ {
+ error ("conversion from %qT to %qT", TREE_TYPE (e), type);
+ inform (input_location, "only %qT can be converted to %qT", type, type);
+ }
+ else
+ error ("conversion to non-scalar type requested");
return error_mark_node;
}
@@ -4531,6 +4531,12 @@ c_init_decl_processing (void)
pushdecl (build_decl (UNKNOWN_LOCATION, TYPE_DECL, get_identifier ("_Bool"),
boolean_type_node));
+ /* C-specific nullptr initialization. */
+ record_builtin_type (RID_MAX, "nullptr_t", nullptr_type_node);
+ /* The size and alignment of nullptr_t is the same as for a pointer to
+ character type. */
+ SET_TYPE_ALIGN (nullptr_type_node, GET_MODE_ALIGNMENT (ptr_mode));
+
input_location = save_loc;
make_fname_decl = c_make_fname_decl;
@@ -119,6 +119,8 @@ c_parse_init (void)
mask |= D_CXXONLY;
if (!flag_isoc99)
mask |= D_C99;
+ if (!flag_isoc2x)
+ mask |= D_C2X;
if (flag_no_asm)
{
mask |= D_ASM | D_EXT;
@@ -10243,6 +10245,14 @@ c_parser_postfix_expression (c_parser *parser)
"%<depend%> clause");
expr.set_error ();
break;
+ /* C23 'nullptr' literal. */
+ case RID_NULLPTR:
+ c_parser_consume_token (parser);
+ expr.value = nullptr_node;
+ set_c_expr_source_range (&expr, tok_range);
+ pedwarn_c11 (loc, OPT_Wpedantic,
+ "ISO C does not support %qs before C2X", "nullptr");
+ break;
default:
c_parser_error (parser, "expected expression");
expr.set_error ();
@@ -133,6 +133,13 @@ null_pointer_constant_p (const_tree expr)
/* This should really operate on c_expr structures, but they aren't
yet available everywhere required. */
tree type = TREE_TYPE (expr);
+
+ /* An integer constant expression with the value 0, such an expression
+ cast to type void*, or the predefined constant nullptr, are a null
+ pointer constant. */
+ if (expr == nullptr_node)
+ return true;
+
return (TREE_CODE (expr) == INTEGER_CST
&& !TREE_OVERFLOW (expr)
&& integer_zerop (expr)
@@ -4575,7 +4582,7 @@ build_unary_op (location_t location, enum tree_code code, tree xarg,
case TRUTH_NOT_EXPR:
if (typecode != INTEGER_TYPE && typecode != FIXED_POINT_TYPE
&& typecode != REAL_TYPE && typecode != POINTER_TYPE
- && typecode != COMPLEX_TYPE)
+ && typecode != COMPLEX_TYPE && typecode != NULLPTR_TYPE)
{
error_at (location,
"wrong type argument to unary exclamation mark");
@@ -5515,6 +5522,13 @@ build_conditional_expr (location_t colon_loc, tree ifexp, bool ifexp_bcp,
}
result_type = type2;
}
+ /* 6.5.15: "if one is a null pointer constant (other than a pointer) or has
+ type nullptr_t and the other is a pointer, the result type is the pointer
+ type." */
+ else if (code1 == NULLPTR_TYPE && code2 == POINTER_TYPE)
+ result_type = type2;
+ else if (code1 == POINTER_TYPE && code2 == NULLPTR_TYPE)
+ result_type = type1;
if (!result_type)
{
@@ -7613,12 +7627,13 @@ convert_for_assignment (location_t location, location_t expr_loc, tree type,
error_at (location, msg);
return error_mark_node;
}
- else if (codel == POINTER_TYPE && coder == INTEGER_TYPE)
+ else if (codel == POINTER_TYPE
+ && (coder == INTEGER_TYPE || coder == NULLPTR_TYPE))
{
- /* An explicit constant 0 can convert to a pointer,
- or one that results from arithmetic, even including
- a cast to integer type. */
- if (!null_pointer_constant)
+ /* An explicit constant 0 or type nullptr_t can convert to a pointer,
+ or one that results from arithmetic, even including a cast to
+ integer type. */
+ if (!null_pointer_constant && coder != NULLPTR_TYPE)
switch (errtype)
{
case ic_argpass:
@@ -7691,7 +7706,10 @@ convert_for_assignment (location_t location, location_t expr_loc, tree type,
return convert (type, rhs);
}
- else if (codel == BOOLEAN_TYPE && coder == POINTER_TYPE)
+ else if (codel == BOOLEAN_TYPE
+ /* The type nullptr_t may be converted to bool. The
+ result is false. */
+ && (coder == POINTER_TYPE || coder == NULLPTR_TYPE))
{
tree ret;
bool save = in_late_binary_op;
@@ -12107,10 +12125,10 @@ build_binary_op (location_t location, enum tree_code code,
case TRUTH_XOR_EXPR:
if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE
|| code0 == REAL_TYPE || code0 == COMPLEX_TYPE
- || code0 == FIXED_POINT_TYPE)
+ || code0 == FIXED_POINT_TYPE || code0 == NULLPTR_TYPE)
&& (code1 == INTEGER_TYPE || code1 == POINTER_TYPE
|| code1 == REAL_TYPE || code1 == COMPLEX_TYPE
- || code1 == FIXED_POINT_TYPE))
+ || code1 == FIXED_POINT_TYPE || code1 == NULLPTR_TYPE))
{
/* Result of these operations is always an int,
but that does not mean the operands should be
@@ -12418,6 +12436,27 @@ build_binary_op (location_t location, enum tree_code code,
result_type = type1;
pedwarn (location, 0, "comparison between pointer and integer");
}
+ /* 6.5.9: One of the following shall hold:
+ -- both operands have type nullptr_t; */
+ else if (code0 == NULLPTR_TYPE && code1 == NULLPTR_TYPE)
+ {
+ result_type = nullptr_type_node;
+ /* No need to convert the operands to result_type later. */
+ converted = 1;
+ }
+ /* -- one operand has type nullptr_t and the other is a null pointer
+ constant. We will have to convert the former to the type of the
+ latter, because during gimplification we can't have mismatching
+ comparison operand type. We convert from nullptr_t to the other
+ type, since only nullptr_t can be converted to nullptr_t. Also,
+ even a constant 0 is a null pointer constant, so we may have to
+ create a pointer type from its type. */
+ else if (code0 == NULLPTR_TYPE && null_pointer_constant_p (orig_op1))
+ result_type = (INTEGRAL_TYPE_P (type1)
+ ? build_pointer_type (type1) : type1);
+ else if (code1 == NULLPTR_TYPE && null_pointer_constant_p (orig_op0))
+ result_type = (INTEGRAL_TYPE_P (type0)
+ ? build_pointer_type (type0) : type0);
if ((TREE_CODE (TREE_TYPE (orig_op0)) == BOOLEAN_TYPE
|| truth_value_p (TREE_CODE (orig_op0)))
^ (TREE_CODE (TREE_TYPE (orig_op1)) == BOOLEAN_TYPE
@@ -187,9 +187,6 @@ enum cp_tree_index
CPTI_NOEXCEPT_FALSE_SPEC,
CPTI_NOEXCEPT_DEFERRED_SPEC,
- CPTI_NULLPTR,
- CPTI_NULLPTR_TYPE,
-
CPTI_ANY_TARG,
CPTI_MODULE_HWM,
@@ -254,8 +251,6 @@ extern GTY(()) tree cp_global_trees[CPTI_MAX];
#define conv_op_marker cp_global_trees[CPTI_CONV_OP_MARKER]
#define abort_fndecl cp_global_trees[CPTI_ABORT_FNDECL]
#define current_aggr cp_global_trees[CPTI_AGGR_TAG]
-#define nullptr_node cp_global_trees[CPTI_NULLPTR]
-#define nullptr_type_node cp_global_trees[CPTI_NULLPTR_TYPE]
/* std::align_val_t */
#define align_type_node cp_global_trees[CPTI_ALIGN_TYPE]
@@ -4405,9 +4400,6 @@ get_vec_init_expr (tree t)
|| TREE_CODE (TYPE) == REAL_TYPE \
|| TREE_CODE (TYPE) == COMPLEX_TYPE)
-/* True iff TYPE is cv decltype(nullptr). */
-#define NULLPTR_TYPE_P(TYPE) (TREE_CODE (TYPE) == NULLPTR_TYPE)
-
/* [basic.types]
Arithmetic types, enumeration types, pointer types,
@@ -4793,16 +4793,10 @@ cxx_init_decl_processing (void)
}
}
- nullptr_type_node = make_node (NULLPTR_TYPE);
- TYPE_SIZE (nullptr_type_node) = bitsize_int (GET_MODE_BITSIZE (ptr_mode));
- TYPE_SIZE_UNIT (nullptr_type_node) = size_int (GET_MODE_SIZE (ptr_mode));
- TYPE_UNSIGNED (nullptr_type_node) = 1;
- TYPE_PRECISION (nullptr_type_node) = GET_MODE_BITSIZE (ptr_mode);
+ /* C++-specific nullptr initialization. */
if (abi_version_at_least (9))
SET_TYPE_ALIGN (nullptr_type_node, GET_MODE_ALIGNMENT (ptr_mode));
- SET_TYPE_MODE (nullptr_type_node, ptr_mode);
record_builtin_type (RID_MAX, "decltype(nullptr)", nullptr_type_node);
- nullptr_node = build_int_cst (nullptr_type_node, 0);
}
if (! supports_one_only ())
@@ -443,6 +443,14 @@ typedef struct {
#endif
#endif /* C++11. */
+#if (defined (__STDC_VERSION__) && __STDC_VERSION__ > 201710L)
+#ifndef _GCC_NULLPTR_T
+#define _GCC_NULLPTR_T
+ typedef __typeof__(nullptr) nullptr_t;
+/* ??? This doesn't define __STDC_VERSION_STDDEF_H__ yet. */
+#endif
+#endif /* C23. */
+
#endif /* _STDDEF_H was defined this time */
#endif /* !_STDDEF_H && !_STDDEF_H_ && !_ANSI_STDDEF_H && !__STDDEF_H__
new file mode 100644
@@ -0,0 +1,10 @@
+/* Test that in pre-C23 modes, nullptr is a normal identifier,
+ not a keyword. */
+/* { dg-options "-std=c11 -pedantic-errors" } */
+
+int nullptr;
+
+void
+f (int nullptr)
+{
+}
new file mode 100644
@@ -0,0 +1,10 @@
+/* Test that in pre-C23 modes, nullptr is a normal identifier,
+ not a keyword. */
+/* { dg-options "-std=c17 -pedantic-errors" } */
+
+int nullptr;
+
+void
+f (int nullptr)
+{
+}
new file mode 100644
@@ -0,0 +1,10 @@
+/* Test that we don't predefine `nullptr' pre-C2X. */
+/* { dg-do compile } */
+/* { dg-options "-std=c17 -pedantic-errors" } */
+
+int *
+fn (int *p)
+{
+ p = nullptr; /* { dg-error "'nullptr' undeclared" } */
+ return p;
+}
new file mode 100644
@@ -0,0 +1,298 @@
+/* Test valid usage of C23 nullptr. */
+/* { dg-do run } */
+/* { dg-options "-std=c2x -pedantic-errors -Wall -Wextra -Wno-unused-variable" } */
+
+#include <stdarg.h>
+
+typedef __typeof__(nullptr) nullptr_t;
+
+void f1 (nullptr_t) { }
+void f2 (int *) { }
+void f3 (_Bool) { }
+nullptr_t cmp (void) { return nullptr; }
+
+/* The type nullptr_t shall not be converted to any type other than void, bool or
+ a pointer type. No type other than nullptr_t shall be converted to nullptr_t. */
+void
+test1 (void)
+{
+ const nullptr_t nptr = nullptr;
+ static nullptr_t static_nptr;
+ int *p1 = nullptr;
+ void *p2 = nullptr;
+ float *p3 = nullptr;
+ void (*p4)(int) = nullptr;
+ int (*p5)[10] = nullptr;
+ int *p6 = nptr;
+ void *p7 = nptr;
+ float *p8 = nptr;
+ void (*p9)(int) = nptr;
+ int (*p10)[10] = nptr;
+ int *p11 = (int *) nullptr;
+ int *p12 = (int *) nptr;
+ int *p13 = (nullptr);
+ int *p14 = _Generic(0, int : nullptr);
+ if (nullptr || p1 || p2 || p3 || p4 || p5 || p6 || p7 || p8 || p9 || p10
+ || p11 || p12 || p13 || p14)
+ __builtin_abort ();
+
+ _Bool b1 = nullptr;
+ _Bool b2 = (_Bool) nullptr;
+ _Bool b3 = nptr;
+ _Bool b4 = (_Bool) nptr;
+ _Bool b5 = _Generic(0, int : nullptr);
+ if (b1 || b2 || b3 || b4 || b5 || (_Bool) nullptr || (_Bool) nptr)
+ __builtin_abort ();
+
+ __auto_type a1 = nullptr;
+ __auto_type a2 = nptr;
+
+ /* We can convert nullptr_t to nullptr_t. */
+ __typeof__(nullptr) x = nullptr;
+ f1 (x);
+ f1 (nullptr);
+ f1 (_Generic(0, int : nullptr));
+ f2 (x);
+ f2 (nullptr);
+ f3 (nullptr);
+
+ const nullptr_t np1 = nullptr;
+ const nullptr_t np2 = np1;
+ (void) nullptr;
+ (void) np1;
+ (void) np2;
+ (void) cmp ();
+ (void)(nullptr_t) nullptr;
+}
+
+/* Test valid comparison. */
+void
+test2 (int *p)
+{
+ /* If both operands have type nullptr_t or one operand has type nullptr_t
+ and the other is a null pointer constant, they compare equal. */
+ const nullptr_t nptr = nullptr;
+ int r = 0;
+
+ /* Both operands have type nullptr_t. */
+ r |= nullptr != nullptr;
+ r |= cmp () != nullptr;
+ r |= nullptr != cmp ();
+ r |= !(nullptr == nullptr);
+ r |= !(cmp () == nullptr);
+ r |= !(nullptr == cmp ());
+ r |= nptr != nptr;
+ r |= cmp () != nptr;
+ r |= nptr != cmp ();
+ r |= !(nptr == nptr);
+ r |= !(cmp () == nptr);
+ r |= !(nptr == cmp ());
+
+ /* One operand has type nullptr_t and the other is a null pointer constant. */
+ r |= nullptr != (void *) 0;
+ r |= _Generic(0, int : nullptr) != (void *) 0;
+ r |= (nullptr) != (void *) 0;
+ r |= !(nullptr == (void *) 0);
+ r |= (void *) 0 != nullptr;
+ r |= (void *) 0 != (nullptr);
+ r |= !((void *) 0 == nullptr);
+ r |= nullptr != 0;
+ r |= _Generic(0, int : nullptr) != 0;
+ r |= (nullptr) != 0;
+ r |= 0 != nullptr;
+ r |= 0 != (nullptr);
+ r |= !(nullptr == 0);
+ r |= !(0 == nullptr);
+ r |= nullptr != 0u;
+ r |= 0u != nullptr;
+ r |= !(nullptr == 0u);
+ r |= !(0u == nullptr);
+ r |= nptr != (void *) 0;
+ r |= !(nptr == (void *) 0);
+ r |= (void *) 0 != nptr;
+ r |= !((void *) 0 == nptr);
+ r |= nptr != 0;
+ r |= 0 != nptr;
+ r |= !(nptr == 0);
+ r |= !(0 == nptr);
+ r |= nptr != 0u;
+ r |= 0u != nptr;
+ r |= !(nptr == 0u);
+ r |= !(0u == nptr);
+ r |= nptr != _Generic(0, int : nullptr);
+ r |= _Generic(0, int : nullptr) != nptr;
+ if (r)
+ __builtin_abort ();
+
+ /* One operand is a pointer and the other is a null pointer constant. */
+ (void) (p == nullptr);
+ (void) (p != nullptr);
+ (void) (nullptr == p);
+ (void) (nullptr != p);
+ (void) (p == (nullptr));
+ (void) (p != (nullptr));
+ (void) ((nullptr) == p);
+ (void) ((nullptr) != p);
+ (void) ((void *)nullptr == nullptr);
+ (void) ((void *)nullptr != nullptr);
+ (void) (nullptr == (void *)nullptr);
+ (void) (nullptr != (void *)nullptr);
+ (void) (p == _Generic(0, int : nullptr));
+ (void) (p != _Generic(0, int : nullptr));
+ (void) (_Generic(0, int : nullptr) == p);
+ (void) (_Generic(0, int : nullptr) != p);
+}
+
+/* Test ?:. */
+void
+test3 (int *p, _Bool b)
+{
+ int x = nullptr ? 1 : 2;
+ (void) x;
+ const nullptr_t nptr = nullptr;
+ /* One of the following shall hold for the second and third operands:
+ -- both operands have nullptr_t type. */
+ __auto_type r1 = b ? nullptr : nullptr;
+ __auto_type r2 = b ? nptr : nptr;
+ /* -- one operand is a pointer and the other is a null pointer constant
+ or has type nullptr_t; */
+ __auto_type r3 = b ? p : nullptr;
+ __auto_type r4 = b ? nullptr : p;
+ __auto_type r5 = b ? nptr : p;
+ __auto_type r6 = b ? p : nptr;
+ __auto_type r7 = b ? 0 : p;
+ __auto_type r8 = b ? p : 0;
+ __auto_type r9 = b ? p : cmp ();
+ __auto_type r10 = b ? cmp () : p;
+ __auto_type r11 = b ? p : _Generic(0, int : nullptr);
+ __auto_type r12 = b ? _Generic(0, int : nullptr) : p;
+}
+
+void test_arg1 (const nullptr_t, _Atomic nullptr_t, volatile nullptr_t) { }
+void test_arg2 (_Atomic int *, const int *, volatile int *) { }
+void test_arg3 (_Atomic _Bool, const _Bool, volatile _Bool) { }
+nullptr_t retn (void) { return nullptr; }
+_Atomic int *ai (void) { return nullptr; }
+const int *ci (void) { return nullptr; }
+volatile int *vi (void) { return nullptr; }
+_Bool retb (void) { return nullptr; }
+
+/* Simple assignment. */
+void
+test4 (void)
+{
+ /* -- the left operand has an atomic, qualified, or unqualified version of
+ the nullptr_t type and the type of the right is nullptr_t; */
+ nullptr_t n1;
+ const nullptr_t n2 = nullptr;
+ _Atomic nullptr_t n3 = nullptr;
+ volatile nullptr_t n4 = nullptr;
+ _Atomic volatile nullptr_t n5 = nullptr;
+ n1 = nullptr;
+ n3 = nullptr;
+ n4 = nullptr;
+ n5 = nullptr;
+ n5 = _Generic(0, int : nullptr);
+ /* -- the left operand is an atomic, qualified, or unqualified pointer,
+ and the type of the right is nullptr_t; */
+ int *p1 = cmp ();
+ _Atomic int *p2 = cmp ();
+ const int *volatile p3 = cmp ();
+ const int *const *const p4 = cmp ();
+ double (*const p5)(void) = n1;
+ p2 = _Generic(0, int : nullptr);
+ p3 = nullptr;
+ /* -- the left operand is an atomic, qualified, or unqualified bool, and
+ the type of the right is nullptr_t; */
+ _Bool b1;
+ b1 = cmp ();
+ const _Bool b2 = nullptr;
+ _Atomic _Bool b3;
+ b3 = n1;
+ (void) b1;
+ (void) b3;
+ (void) n3;
+ (void) n4;
+ (void) n5;
+ (void) p2;
+ (void) p3;
+
+ test_arg1 (nullptr, nullptr, nullptr);
+ test_arg2 (nullptr, nullptr, nullptr);
+ test_arg3 (nullptr, nullptr, nullptr);
+}
+
+/* var_arg etc. */
+static void
+test5 (int i, ...)
+{
+ va_list ap;
+ va_start (ap, i);
+ if (va_arg (ap, void *))
+ __builtin_abort ();
+}
+
+/* Operand of alignas, sizeof or typeof operators. */
+void
+test6 (void)
+{
+ _Static_assert (sizeof (nullptr) == sizeof (void *), "sizeof (nullptr)");
+ _Static_assert (sizeof (nullptr_t) == sizeof (void *), "sizeof (nullptr_t)");
+ _Static_assert (sizeof (nullptr) == sizeof (char *), "sizeof (nullptr)");
+ _Static_assert (sizeof (nullptr_t) == sizeof (char *), "sizeof (nullptr_t)");
+ _Static_assert (_Alignof (nullptr_t) == _Alignof (char *), "_Alignof (nullptr_t)");
+ __typeof__(nullptr) t = nullptr;
+ f1 (t);
+ _Alignas (nullptr_t) char i1 = 'q';
+
+ _Static_assert (_Generic (nullptr, nullptr_t: 1, default: 0) == 1, "_Generic");
+ _Static_assert (_Generic (t, nullptr_t: 1, default: 0) == 1, "_Generic");
+ _Static_assert (_Generic (cmp (), nullptr_t: 1, default: 0) == 1, "_Generic");
+ _Static_assert (_Generic (0, nullptr_t: 1, int: 2, default: 0) == 2, "_Generic");
+ _Static_assert (_Generic ((void *)0, nullptr_t: 1, void *: 2, default: 0) == 2, "_Generic");
+ _Static_assert (_Generic (nullptr, nullptr_t: 1, void *: 2, default: 0) == 1, "_Generic");
+}
+
+/* Play with !, ||, &&. */
+void
+test7 (void)
+{
+ if (nullptr)
+ __builtin_abort ();
+ if (1 && nullptr)
+ __builtin_abort ();
+ if (0 || nullptr)
+ __builtin_abort ();
+ if (nullptr && 1)
+ __builtin_abort ();
+ if (nullptr || 0)
+ __builtin_abort ();
+ if (!nullptr)
+ {
+ }
+ else
+ __builtin_abort ();
+ while (nullptr)
+ __builtin_abort ();
+ int i = 0;
+ do
+ ++i;
+ while (nullptr);
+ if (i != 1)
+ __builtin_abort ();
+ for (;nullptr;)
+ __builtin_abort ();
+}
+
+int
+main (void)
+{
+ int i = 42;
+ test1 ();
+ test2 (&i);
+ test3 (&i, 0);
+ test4 ();
+ test5 (42, nullptr);
+ test6 ();
+ test7 ();
+}
new file mode 100644
@@ -0,0 +1,9 @@
+/* Test nullptr_t from <stddef.h>. */
+/* { dg-do compile } */
+/* { dg-options "-std=c2x -pedantic-errors" } */
+
+#include <stddef.h>
+
+void f(nullptr_t);
+_Static_assert (sizeof (nullptr_t) == sizeof (char *), "sizeof (nullptr_t)");
+_Static_assert (_Alignof (nullptr_t) == _Alignof (char *), "_Alignof (nullptr_t)");
new file mode 100644
@@ -0,0 +1,80 @@
+/* Test wrong usage of C23 nullptr. */
+/* { dg-do compile } */
+/* { dg-options "-std=c2x -pedantic-errors -Wall -Wextra -Wno-unused-variable" } */
+
+typedef __typeof__(nullptr) nullptr_t;
+
+void g (nullptr_t); /* { dg-message "expected .nullptr_t. but argument is of type .int." } */
+nullptr_t cmp (void);
+
+void
+test1 (int *p)
+{
+ (void) (p > nullptr); /* { dg-error "ordered comparison" } */
+ (void) (p >= nullptr); /* { dg-error "ordered comparison" } */
+ (void) (p < nullptr); /* { dg-error "ordered comparison" } */
+ (void) (p <= nullptr); /* { dg-error "ordered comparison" } */
+ (void) (nullptr == 1); /* { dg-error "invalid operands" } */
+ (void) (1 == nullptr); /* { dg-error "invalid operands" } */
+ (void) (nullptr != 1); /* { dg-error "invalid operands" } */
+ (void) (1 != nullptr); /* { dg-error "invalid operands" } */
+ (void) (1 > nullptr); /* { dg-error "invalid operands" } */
+
+ /* "(nullptr_t)nullptr" has type nullptr_t but isn't an NPC. */
+ (void) ((nullptr_t)nullptr == p); /* { dg-error "invalid operands" } */
+ (void) ((nullptr_t)nullptr != p); /* { dg-error "invalid operands" } */
+ (void) (p == (nullptr_t)nullptr); /* { dg-error "invalid operands" } */
+ (void) (p != (nullptr_t)nullptr); /* { dg-error "invalid operands" } */
+ (void) (cmp () == p); /* { dg-error "invalid operands" } */
+ (void) (cmp () != p); /* { dg-error "invalid operands" } */
+ (void) (p == cmp ()); /* { dg-error "invalid operands" } */
+ (void) (p != cmp ()); /* { dg-error "invalid operands" } */
+ /* "(void *)nullptr" is not an NPC, either. */
+ (void) ((void *)nullptr == cmp ()); /* { dg-error "invalid operands" } */
+ (void) ((void *)nullptr != cmp ()); /* { dg-error "invalid operands" } */
+ (void) (cmp () == (void *)nullptr); /* { dg-error "invalid operands" } */
+ (void) (cmp () != (void *)nullptr); /* { dg-error "invalid operands" } */
+}
+
+void
+test2 (void)
+{
+ const nullptr_t nptr = nullptr;
+ int p = nullptr; /* { dg-error "incompatible types" } */
+ float d = nullptr; /* { dg-error "incompatible types" } */
+ char arr[10] = { nullptr }; /* { dg-error "incompatible types" } */
+
+ /* No type other than nullptr_t shall be converted to nullptr_t. */
+ const nullptr_t n = 0; /* { dg-error "invalid initializer" } */
+ +(nullptr_t) 0; /* { dg-error "conversion from .int. to .nullptr_t." } */
+
+ g (0); /* { dg-error "incompatible type" } */
+
+ int i = 42 + nullptr; /* { dg-error "invalid operands" } */
+
+ /* The assignment of an object of type nullptr_t with a value of another
+ type, even if the value is a null pointer constant, is a constraint
+ violation. */
+ nullptr_t m;
+ m = 0; /* { dg-error "incompatible types" } */
+ (void) m;
+ nullptr_t o = 0; /* { dg-error "invalid initializer" } */
+
+ switch (nullptr); /* { dg-error "switch quantity not an integer" } */
+}
+
+/* If a second or third operand of type nullptr_t is used that is not a null
+ pointer constant and the other operand is not a pointer or does not have
+ itself nullptr_t, a constraint is violated even if that other operand is
+ a null pointer constant such as 0. */
+void
+test3 (_Bool b, int i)
+{
+ const nullptr_t nptr = nullptr;
+ __auto_type a1 = b ? nptr : i; /* { dg-error "type mismatch" } */
+ __auto_type a2 = b ? i : nptr; /* { dg-error "type mismatch" } */
+ __auto_type a3 = b ? nptr : 0; /* { dg-error "type mismatch" } */
+ __auto_type a4 = b ? 0 : nptr; /* { dg-error "type mismatch" } */
+ __auto_type a5 = b ? 0 : nullptr; /* { dg-error "type mismatch" } */
+ __auto_type a6 = b ? nullptr : 0; /* { dg-error "type mismatch" } */
+}
new file mode 100644
@@ -0,0 +1,11 @@
+/* Test that -Wc11-c2x-compat issues a warning (not a pedwarn) about
+ `nullptr' in C2X. */
+/* { dg-do compile } */
+/* { dg-options "-std=c2x -pedantic-errors -Wc11-c2x-compat" } */
+
+int *
+fn (int *p)
+{
+ p = nullptr; /* { dg-warning "ISO C does not support .nullptr. before C2X" } */
+ return p;
+}
new file mode 100644
@@ -0,0 +1,14 @@
+/* Test that we don't lose side-effects when converting from nullptr_t. */
+/* { dg-do run } */
+/* { dg-options "-std=c2x -pedantic-errors" } */
+
+int i;
+nullptr_t fn () { ++i; return nullptr; }
+
+int
+main ()
+{
+ int *p = fn ();
+ if (i != 1)
+ __builtin_abort ();
+}