GCC默认定义的预编译宏

gcc -E -dM - 

在msys2中指向的结果为:

#define __DBL_MIN_EXP__ (-1021)#define __UINT_LEAST16_MAX__ 0xffff#define __ATOMIC_ACQUIRE 2#define __FLT_MIN__ 1.17549435082228750797e-38F#define __GCC_IEC_559_COMPLEX 2#define __UINT_LEAST8_TYPE__ unsigned char#define __SIZEOF_FLOAT80__ 16#define __INTMAX_C(c) c ## L#define __CHAR_BIT__ 8#define __UINT8_MAX__ 0xff#define __WINT_MAX__ 0xffffffffU#define __ORDER_LITTLE_ENDIAN__ 1234#define __SIZE_MAX__ 0xffffffffffffffffUL#define __WCHAR_MAX__ 0xffff#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_1 1#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 1#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 1#define __DBL_DENORM_MIN__ ((double)4.94065645841246544177e-324L)#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 1#define __GCC_ATOMIC_CHAR_LOCK_FREE 2#define __GCC_IEC_559 2#define __FLT_EVAL_METHOD__ 0#define __unix__ 1#define __GCC_ATOMIC_CHAR32_T_LOCK_FREE 2#define __x86_64 1#define __UINT_FAST64_MAX__ 0xffffffffffffffffUL#define __SIG_ATOMIC_TYPE__ int#define __DBL_MIN_10_EXP__ (-307)#define __FINITE_MATH_ONLY__ 0#define __GNUC_PATCHLEVEL__ 0#define __UINT_FAST8_MAX__ 0xff#define __has_include(STR) __has_include__(STR)#define _stdcall __attribute__((__stdcall__))#define __DEC64_MAX_EXP__ 385#define __INT8_C(c) c#define __UINT_LEAST64_MAX__ 0xffffffffffffffffUL#define __SHRT_MAX__ 0x7fff#define __LDBL_MAX__ 1.18973149535723176502e+4932L#define __UINT_LEAST8_MAX__ 0xff#define __GCC_ATOMIC_BOOL_LOCK_FREE 2#define __UINTMAX_TYPE__ long unsigned int#define __DEC32_EPSILON__ 1E-6DF#define __unix 1#define __UINT32_MAX__ 0xffffffffU#define __LDBL_MAX_EXP__ 16384#define __WINT_MIN__ 0U#define __SCHAR_MAX__ 0x7f#define __WCHAR_MIN__ 0#define __INT64_C(c) c ## L#define __DBL_DIG__ 15#define __GCC_ATOMIC_POINTER_LOCK_FREE 2#define __SIZEOF_INT__ 4#define __SIZEOF_POINTER__ 8#define __USER_LABEL_PREFIX__#define __STDC_HOSTED__ 1#define __LDBL_HAS_INFINITY__ 1#define __FLT_EPSILON__ 1.19209289550781250000e-7F#define __LDBL_MIN__ 3.36210314311209350626e-4932L#define __STDC_UTF_16__ 1#define __DEC32_MAX__ 9.999999E96DF#define __INT32_MAX__ 0x7fffffff#define __SIZEOF_LONG__ 8#define __UINT16_C(c) c#define __DECIMAL_DIG__ 21#define __has_include_next(STR) __has_include_next__(STR)#define __LDBL_HAS_QUIET_NAN__ 1#define __GNUC__ 5#define _cdecl __attribute__((__cdecl__))#define __MMX__ 1#define __FLT_HAS_DENORM__ 1#define __SIZEOF_LONG_DOUBLE__ 16#define __BIGGEST_ALIGNMENT__ 16#define __MSYS__ 1#define __DBL_MAX__ ((double)1.79769313486231570815e+308L)#define _thiscall __attribute__((__thiscall__))#define __INT_FAST32_MAX__ 0x7fffffffffffffffL#define __DBL_HAS_INFINITY__ 1#define __DEC32_MIN_EXP__ (-94)#define __INT_FAST16_TYPE__ long int#define _fastcall __attribute__((__fastcall__))#define __LDBL_HAS_DENORM__ 1#define __DEC128_MAX__ 9.999999999999999999999999999999999E6144DL#define __INT_LEAST32_MAX__ 0x7fffffff#define __DEC32_MIN__ 1E-95DF#define __DBL_MAX_EXP__ 1024#define __DEC128_EPSILON__ 1E-33DL#define __SSE2_MATH__ 1#define __ATOMIC_HLE_RELEASE 131072#define __PTRDIFF_MAX__ 0x7fffffffffffffffL#define __amd64 1#define __ATOMIC_HLE_ACQUIRE 65536#define __LONG_LONG_MAX__ 0x7fffffffffffffffLL#define __SIZEOF_SIZE_T__ 8#define __SIZEOF_WINT_T__ 4#define __GXX_ABI_VERSION 1009#define __FLT_MIN_EXP__ (-125)#define __INT_FAST64_TYPE__ long int#define __DBL_MIN__ ((double)2.22507385850720138309e-308L)#define __LP64__ 1#define __DECIMAL_BID_FORMAT__ 1#define __GXX_TYPEINFO_EQUALITY_INLINE 0#define __DEC128_MIN__ 1E-6143DL#define __REGISTER_PREFIX__#define __UINT16_MAX__ 0xffff#define __DBL_HAS_DENORM__ 1#define __cdecl __attribute__((__cdecl__))#define __UINT8_TYPE__ unsigned char#define __NO_INLINE__ 1#define __FLT_MANT_DIG__ 24#define __VERSION__ "5.3.0"#define __UINT64_C(c) c ## UL#define __GCC_ATOMIC_INT_LOCK_FREE 2#define __FLOAT_WORD_ORDER__ __ORDER_LITTLE_ENDIAN__#define __INT32_C(c) c#define __DEC64_EPSILON__ 1E-15DD#define __ORDER_PDP_ENDIAN__ 3412#define __DEC128_MIN_EXP__ (-6142)#define __INT_FAST32_TYPE__ long int#define __UINT_LEAST16_TYPE__ short unsigned int#define unix 1#define __INT16_MAX__ 0x7fff#define __SIZE_TYPE__ long unsigned int#define __UINT64_MAX__ 0xffffffffffffffffUL#define __INT8_TYPE__ signed char#define __FLT_RADIX__ 2#define __INT_LEAST16_TYPE__ short int#define __LDBL_EPSILON__ 1.08420217248550443401e-19L#define __UINTMAX_C(c) c ## UL#define __SSE_MATH__ 1#define __k8 1#define __SEH__ 1#define __SIG_ATOMIC_MAX__ 0x7fffffff#define __GCC_ATOMIC_WCHAR_T_LOCK_FREE 2#define __SIZEOF_PTRDIFF_T__ 8#define __CYGWIN__ 1#define __x86_64__ 1#define __DEC32_SUBNORMAL_MIN__ 0.000001E-95DF#define __INT_FAST16_MAX__ 0x7fffffffffffffffL#define __UINT_FAST32_MAX__ 0xffffffffffffffffUL#define __UINT_LEAST64_TYPE__ long unsigned int#define __FLT_HAS_QUIET_NAN__ 1#define __FLT_MAX_10_EXP__ 38#define __LONG_MAX__ 0x7fffffffffffffffL#define __DEC128_SUBNORMAL_MIN__ 0.000000000000000000000000000000001E-6143DL#define __FLT_HAS_INFINITY__ 1#define __UINT_FAST16_TYPE__ long unsigned int#define __DEC64_MAX__ 9.999999999999999E384DD#define __CHAR16_TYPE__ short unsigned int#define __PRAGMA_REDEFINE_EXTNAME 1#define __INT_LEAST16_MAX__ 0x7fff#define __DEC64_MANT_DIG__ 16#define __INT64_MAX__ 0x7fffffffffffffffL#define __UINT_LEAST32_MAX__ 0xffffffffU#define __GCC_ATOMIC_LONG_LOCK_FREE 2#define __INT_LEAST64_TYPE__ long int#define __INT16_TYPE__ short int#define __INT_LEAST8_TYPE__ signed char#define __STDC_VERSION__ 201112L#define __DEC32_MAX_EXP__ 97#define __INT_FAST8_MAX__ 0x7f#define __INTPTR_MAX__ 0x7fffffffffffffffL#define __GXX_MERGED_TYPEINFO_NAMES 0#define __stdcall __attribute__((__stdcall__))#define __SSE2__ 1#define __LDBL_MANT_DIG__ 64#define __DBL_HAS_QUIET_NAN__ 1#define __SIG_ATOMIC_MIN__ (-__SIG_ATOMIC_MAX__ - 1)#define __k8__ 1#define __INTPTR_TYPE__ long int#define __UINT16_TYPE__ short unsigned int#define __WCHAR_TYPE__ short unsigned int#define __SIZEOF_FLOAT__ 4#define __pic__ 1#define __UINTPTR_MAX__ 0xffffffffffffffffUL#define __DEC64_MIN_EXP__ (-382)#define __INT_FAST64_MAX__ 0x7fffffffffffffffL#define __GCC_ATOMIC_TEST_AND_SET_TRUEVAL 1#define __FLT_DIG__ 6#define __UINT_FAST64_TYPE__ long unsigned int#define __INT_MAX__ 0x7fffffff#define __amd64__ 1#define __code_model_medium__ 1#define __INT64_TYPE__ long int#define __FLT_MAX_EXP__ 128#define __ORDER_BIG_ENDIAN__ 4321#define __DBL_MANT_DIG__ 53#define __SIZEOF_FLOAT128__ 16#define __INT_LEAST64_MAX__ 0x7fffffffffffffffL#define __GCC_ATOMIC_CHAR16_T_LOCK_FREE 2#define __DEC64_MIN__ 1E-383DD#define __WINT_TYPE__ unsigned int#define __UINT_LEAST32_TYPE__ unsigned int#define __SIZEOF_SHORT__ 2#define __SSE__ 1#define __LDBL_MIN_EXP__ (-16381)#define __INT_LEAST8_MAX__ 0x7f#define __SIZEOF_INT128__ 16#define __LDBL_MAX_10_EXP__ 4932#define __ATOMIC_RELAXED 0#define __DBL_EPSILON__ ((double)2.22044604925031308085e-16L)#define __thiscall __attribute__((__thiscall__))#define _LP64 1#define __UINT8_C(c) c#define __INT_LEAST32_TYPE__ int#define __SIZEOF_WCHAR_T__ 2#define __UINT64_TYPE__ long unsigned int#define __INT_FAST8_TYPE__ signed char#define __fastcall __attribute__((__fastcall__))#define __GNUC_STDC_INLINE__ 1#define __DBL_DECIMAL_DIG__ 17#define __STDC_UTF_32__ 1#define __FXSR__ 1#define __DEC_EVAL_METHOD__ 2#define __UINT32_C(c) c ## U#define __INTMAX_MAX__ 0x7fffffffffffffffL#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__#define __FLT_DENORM_MIN__ 1.40129846432481707092e-45F#define __INT8_MAX__ 0x7f#define __PIC__ 1#define __UINT_FAST32_TYPE__ long unsigned int#define __CHAR32_TYPE__ unsigned int#define __FLT_MAX__ 3.40282346638528859812e+38F#define __INT32_TYPE__ int#define __SIZEOF_DOUBLE__ 8#define __FLT_MIN_10_EXP__ (-37)#define __INTMAX_TYPE__ long int#define __DEC128_MAX_EXP__ 6145#define __ATOMIC_CONSUME 1#define __GNUC_MINOR__ 3#define __UINTMAX_MAX__ 0xffffffffffffffffUL#define __DEC32_MANT_DIG__ 7#define __DBL_MAX_10_EXP__ 308#define __LDBL_DENORM_MIN__ 3.64519953188247460253e-4951L#define __INT16_C(c) c#define __STDC__ 1#define __PTRDIFF_TYPE__ long int#define __ATOMIC_SEQ_CST 5#define __UINT32_TYPE__ unsigned int#define __UINTPTR_TYPE__ long unsigned int#define __DEC64_SUBNORMAL_MIN__ 0.000000000000001E-383DD#define __DEC128_MANT_DIG__ 34#define __LDBL_MIN_10_EXP__ (-4931)#define __SIZEOF_LONG_LONG__ 8#define __GCC_ATOMIC_LLONG_LOCK_FREE 2#define __LDBL_DIG__ 18#define __FLT_DECIMAL_DIG__ 9#define __UINT_FAST16_MAX__ 0xffffffffffffffffUL#define __GCC_ATOMIC_SHORT_LOCK_FREE 2#define __UINT_FAST8_TYPE__ unsigned char#define __ATOMIC_ACQ_REL 4#define __ATOMIC_RELEASE 3#define __declspec(x) __attribute__((x))