clang/test/C/C2x/n3035.c

   1 // RUN: %clang_cc1 -triple x86_64 -ffreestanding -verify -std=c2x %s
   2
   3 /* WG14 N3035: yes
   4  * _BitInt Fixes
   5  */
   6
   7 #include <stdint.h>
   8
   9 /* intmax_t and uintmax_t don't need to be able to represent all of the values
  10  * of a bit-precise integer type. We test this by using a bit-precise integer
  11  * suffix on some huge values used within the preprocessor.
  12  */
  13 #if 0x1'FFFF'FFFF'FFFF'FFFFwb == 0 /* expected-error {{integer literal is too large to be represented in any integer type}} */
  14 #endif
  15
  16 /* Yet we can use that value as an initializer... */
  17 _BitInt(66) Val = 0x1'FFFF'FFFF'FFFF'FFFFwb;
  18
  19 /* ...so long as the type is wide enough. */
  20 intmax_t WrongVal = 0x1'FFFF'FFFF'FFFF'FFFFwb; /* expected-warning-re {{implicit conversion from '_BitInt(66)' to 'intmax_t' (aka '{{.*}}') changes value from 36893488147419103231 to -1}} */
  21
  22 /* None of the types in stdint.h may be defined in terms of a bit-precise
  23  * integer type. This macro presumes that if the type is not one of the builtin
  24  * scalar integer types, the type must be a bit-precise type. We're using this
  25  * because C does not have a particularly straightforward way to use _Generic
  26  * with arbitrary bit-precise integer types.
  27  */
  28 #define IS_NOT_BIT_PRECISE(TYPE) _Generic((TYPE){ 0 },                          \
  29                                    short : 1, int : 1, long : 1, long long : 1, \
  30                                    unsigned short : 1, unsigned int : 1,        \
  31                                    unsigned long : 1, unsigned long long : 1,   \
  32                                    char : 1, signed char : 1, unsigned char : 1,\
  33                                    default : 0)
  34 static_assert(IS_NOT_BIT_PRECISE(int8_t));
  35 static_assert(IS_NOT_BIT_PRECISE(uint8_t));
  36 static_assert(IS_NOT_BIT_PRECISE(int16_t));
  37 static_assert(IS_NOT_BIT_PRECISE(uint16_t));
  38 static_assert(IS_NOT_BIT_PRECISE(int32_t));
  39 static_assert(IS_NOT_BIT_PRECISE(uint32_t));
  40 static_assert(IS_NOT_BIT_PRECISE(int64_t));
  41 static_assert(IS_NOT_BIT_PRECISE(uint64_t));
  42 static_assert(IS_NOT_BIT_PRECISE(intmax_t));
  43 static_assert(IS_NOT_BIT_PRECISE(uintmax_t));
  44 static_assert(IS_NOT_BIT_PRECISE(intptr_t));
  45 static_assert(IS_NOT_BIT_PRECISE(uintptr_t));
  46
  47 /* FIXME: N3035 also added wording disallowing using a bit-precise integer type
  48  * as the compatible type for an enumerated type. However, we don't have a
  49  * direct way to test that, so we're claiming conformance without test
  50  * coverage.
  51  */