Getting a list of all predefined compiler macros

Andreas · February 16, 2019, 5:44pm

While working on Improving the canonical Arduino HX711 library for ESP32 and beyond, we had the need to reliably detect the target platform architecture the code is compiled for. After some investigations it turned out we should not rely on the board definition stuff circulating around the Arduino HAL too much, as a) we would have to enumerate all boards to check for them (Sisyphos) and b) when it really comes to hardware-related conditions, this would not help at all.

So, we started to investigate into the macros defined by the crossplatform compilers like "avr-gcc", "xtensa-lx106-elf-g++" and "arm-gcc" and want to just list them here for reference as we couldn’t find a complete list on the Web.

– avr-gcc specific compilation | AVR Freaks

Andreas · February 16, 2019, 5:47pm

`avr-gcc`

We conclude from the following summary that "#ifdef AVR" resp. "#if defined(AVR)" would be the right thing to check for the AVR target.

avr-gcc -dM -E

$ avr-gcc -dM -E - < /dev/null | sort | uniq

#define AVR 1
#define __ACCUM_EPSILON__ 0x1P-15K
#define __ACCUM_FBIT__ 15
#define __ACCUM_IBIT__ 16
#define __ACCUM_MAX__ 0X7FFFFFFFP-15K
#define __ACCUM_MIN__ (-0X1P15K-0X1P15K)
#define __ATOMIC_ACQUIRE 2
#define __ATOMIC_ACQ_REL 4
#define __ATOMIC_CONSUME 1
#define __ATOMIC_RELAXED 0
#define __ATOMIC_RELEASE 3
#define __ATOMIC_SEQ_CST 5
#define __AVR 1
#define __AVR_2_BYTE_PC__ 1
#define __AVR_ARCH__ 2
#define __AVR_ERRATA_SKIP__ 1
#define __AVR_HAVE_16BIT_SP__ 1
#define __AVR_HAVE_SPH__ 1
#define __AVR_SFR_OFFSET__ 0x20
#define __AVR__ 1
#define __BIGGEST_ALIGNMENT__ 1
#define __BUILTIN_AVR_ABSFX 1
#define __BUILTIN_AVR_ABSHK 1
#define __BUILTIN_AVR_ABSHR 1
#define __BUILTIN_AVR_ABSK 1
#define __BUILTIN_AVR_ABSLK 1
#define __BUILTIN_AVR_ABSLLK 1
#define __BUILTIN_AVR_ABSLLR 1
#define __BUILTIN_AVR_ABSLR 1
#define __BUILTIN_AVR_ABSR 1
#define __BUILTIN_AVR_BITSHK 1
#define __BUILTIN_AVR_BITSHR 1
#define __BUILTIN_AVR_BITSK 1
#define __BUILTIN_AVR_BITSLK 1
#define __BUILTIN_AVR_BITSLLK 1
#define __BUILTIN_AVR_BITSLLR 1
#define __BUILTIN_AVR_BITSLR 1
#define __BUILTIN_AVR_BITSR 1
#define __BUILTIN_AVR_BITSUHK 1
#define __BUILTIN_AVR_BITSUHR 1
#define __BUILTIN_AVR_BITSUK 1
#define __BUILTIN_AVR_BITSULK 1
#define __BUILTIN_AVR_BITSULLK 1
#define __BUILTIN_AVR_BITSULLR 1
#define __BUILTIN_AVR_BITSULR 1
#define __BUILTIN_AVR_BITSUR 1
#define __BUILTIN_AVR_CLI 1
#define __BUILTIN_AVR_COUNTLSFX 1
#define __BUILTIN_AVR_COUNTLSHK 1
#define __BUILTIN_AVR_COUNTLSHR 1
#define __BUILTIN_AVR_COUNTLSK 1
#define __BUILTIN_AVR_COUNTLSLK 1
#define __BUILTIN_AVR_COUNTLSLLK 1
#define __BUILTIN_AVR_COUNTLSLLR 1
#define __BUILTIN_AVR_COUNTLSLR 1
#define __BUILTIN_AVR_COUNTLSR 1
#define __BUILTIN_AVR_COUNTLSUHK 1
#define __BUILTIN_AVR_COUNTLSUHR 1
#define __BUILTIN_AVR_COUNTLSUK 1
#define __BUILTIN_AVR_COUNTLSULK 1
#define __BUILTIN_AVR_COUNTLSULLK 1
#define __BUILTIN_AVR_COUNTLSULLR 1
#define __BUILTIN_AVR_COUNTLSULR 1
#define __BUILTIN_AVR_COUNTLSUR 1
#define __BUILTIN_AVR_DELAY_CYCLES 1
#define __BUILTIN_AVR_FLASH_SEGMENT 1
#define __BUILTIN_AVR_FMUL 1
#define __BUILTIN_AVR_FMULS 1
#define __BUILTIN_AVR_FMULSU 1
#define __BUILTIN_AVR_HKBITS 1
#define __BUILTIN_AVR_HRBITS 1
#define __BUILTIN_AVR_INSERT_BITS 1
#define __BUILTIN_AVR_KBITS 1
#define __BUILTIN_AVR_LKBITS 1
#define __BUILTIN_AVR_LLKBITS 1
#define __BUILTIN_AVR_LLRBITS 1
#define __BUILTIN_AVR_LRBITS 1
#define __BUILTIN_AVR_NOP 1
#define __BUILTIN_AVR_NOPS 1
#define __BUILTIN_AVR_RBITS 1
#define __BUILTIN_AVR_ROUNDFX 1
#define __BUILTIN_AVR_ROUNDHK 1
#define __BUILTIN_AVR_ROUNDHR 1
#define __BUILTIN_AVR_ROUNDK 1
#define __BUILTIN_AVR_ROUNDLK 1
#define __BUILTIN_AVR_ROUNDLLK 1
#define __BUILTIN_AVR_ROUNDLLR 1
#define __BUILTIN_AVR_ROUNDLR 1
#define __BUILTIN_AVR_ROUNDR 1
#define __BUILTIN_AVR_ROUNDUHK 1
#define __BUILTIN_AVR_ROUNDUHR 1
#define __BUILTIN_AVR_ROUNDUK 1
#define __BUILTIN_AVR_ROUNDULK 1
#define __BUILTIN_AVR_ROUNDULLK 1
#define __BUILTIN_AVR_ROUNDULLR 1
#define __BUILTIN_AVR_ROUNDULR 1
#define __BUILTIN_AVR_ROUNDUR 1
#define __BUILTIN_AVR_SEI 1
#define __BUILTIN_AVR_SLEEP 1
#define __BUILTIN_AVR_SWAP 1
#define __BUILTIN_AVR_UHKBITS 1
#define __BUILTIN_AVR_UHRBITS 1
#define __BUILTIN_AVR_UKBITS 1
#define __BUILTIN_AVR_ULKBITS 1
#define __BUILTIN_AVR_ULLKBITS 1
#define __BUILTIN_AVR_ULLRBITS 1
#define __BUILTIN_AVR_ULRBITS 1
#define __BUILTIN_AVR_URBITS 1
#define __BUILTIN_AVR_WDR 1
#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
#define __CHAR16_TYPE__ unsigned int
#define __CHAR32_TYPE__ long unsigned int
#define __CHAR_BIT__ 8
#define __DA_FBIT__ 31
#define __DA_IBIT__ 32
#define __DBL_DECIMAL_DIG__ 9
#define __DBL_DENORM_MIN__ ((double)1.40129846e-45L)
#define __DBL_DIG__ 6
#define __DBL_EPSILON__ ((double)1.19209290e-7L)
#define __DBL_HAS_DENORM__ 1
#define __DBL_HAS_INFINITY__ 1
#define __DBL_HAS_QUIET_NAN__ 1
#define __DBL_MANT_DIG__ 24
#define __DBL_MAX_10_EXP__ 38
#define __DBL_MAX_EXP__ 128
#define __DBL_MAX__ ((double)3.40282347e+38L)
#define __DBL_MIN_10_EXP__ (-37)
#define __DBL_MIN_EXP__ (-125)
#define __DBL_MIN__ ((double)1.17549435e-38L)
#define __DEC128_EPSILON__ 1E-33DL
#define __DEC128_MANT_DIG__ 34
#define __DEC128_MAX_EXP__ 6145
#define __DEC128_MAX__ 9.999999999999999999999999999999999E6144DL
#define __DEC128_MIN_EXP__ (-6142)
#define __DEC128_MIN__ 1E-6143DL
#define __DEC128_SUBNORMAL_MIN__ 0.000000000000000000000000000000001E-6143DL
#define __DEC32_EPSILON__ 1E-6DF
#define __DEC32_MANT_DIG__ 7
#define __DEC32_MAX_EXP__ 97
#define __DEC32_MAX__ 9.999999E96DF
#define __DEC32_MIN_EXP__ (-94)
#define __DEC32_MIN__ 1E-95DF
#define __DEC32_SUBNORMAL_MIN__ 0.000001E-95DF
#define __DEC64_EPSILON__ 1E-15DD
#define __DEC64_MANT_DIG__ 16
#define __DEC64_MAX_EXP__ 385
#define __DEC64_MAX__ 9.999999999999999E384DD
#define __DEC64_MIN_EXP__ (-382)
#define __DEC64_MIN__ 1E-383DD
#define __DEC64_SUBNORMAL_MIN__ 0.000000000000001E-383DD
#define __DECIMAL_DIG__ 9
#define __DEC_EVAL_METHOD__ 2
#define __DQ_FBIT__ 63
#define __DQ_IBIT__ 0
#define __ELF__ 1
#define __FINITE_MATH_ONLY__ 0
#define __FLASH 1
#define __FLASH1 1
#define __FLASH2 1
#define __FLASH3 1
#define __FLASH4 1
#define __FLASH5 1
#define __FLOAT_WORD_ORDER__ __ORDER_LITTLE_ENDIAN__
#define __FLT32_DECIMAL_DIG__ 9
#define __FLT32_DENORM_MIN__ 1.40129846e-45F32
#define __FLT32_DIG__ 6
#define __FLT32_EPSILON__ 1.19209290e-7F32
#define __FLT32_HAS_DENORM__ 1
#define __FLT32_HAS_INFINITY__ 1
#define __FLT32_HAS_QUIET_NAN__ 1
#define __FLT32_MANT_DIG__ 24
#define __FLT32_MAX_10_EXP__ 38
#define __FLT32_MAX_EXP__ 128
#define __FLT32_MAX__ 3.40282347e+38F32
#define __FLT32_MIN_10_EXP__ (-37)
#define __FLT32_MIN_EXP__ (-125)
#define __FLT32_MIN__ 1.17549435e-38F32
#define __FLT_DECIMAL_DIG__ 9
#define __FLT_DENORM_MIN__ 1.40129846e-45F
#define __FLT_DIG__ 6
#define __FLT_EPSILON__ 1.19209290e-7F
#define __FLT_EVAL_METHOD_TS_18661_3__ 0
#define __FLT_EVAL_METHOD__ 0
#define __FLT_HAS_DENORM__ 1
#define __FLT_HAS_INFINITY__ 1
#define __FLT_HAS_QUIET_NAN__ 1
#define __FLT_MANT_DIG__ 24
#define __FLT_MAX_10_EXP__ 38
#define __FLT_MAX_EXP__ 128
#define __FLT_MAX__ 3.40282347e+38F
#define __FLT_MIN_10_EXP__ (-37)
#define __FLT_MIN_EXP__ (-125)
#define __FLT_MIN__ 1.17549435e-38F
#define __FLT_RADIX__ 2
#define __FRACT_EPSILON__ 0x1P-15R
#define __FRACT_FBIT__ 15
#define __FRACT_IBIT__ 0
#define __FRACT_MAX__ 0X7FFFP-15R
#define __FRACT_MIN__ (-0.5R-0.5R)
#define __GCC_ATOMIC_BOOL_LOCK_FREE 1
#define __GCC_ATOMIC_CHAR16_T_LOCK_FREE 1
#define __GCC_ATOMIC_CHAR32_T_LOCK_FREE 1
#define __GCC_ATOMIC_CHAR_LOCK_FREE 1
#define __GCC_ATOMIC_INT_LOCK_FREE 1
#define __GCC_ATOMIC_LLONG_LOCK_FREE 1
#define __GCC_ATOMIC_LONG_LOCK_FREE 1
#define __GCC_ATOMIC_POINTER_LOCK_FREE 1
#define __GCC_ATOMIC_SHORT_LOCK_FREE 1
#define __GCC_ATOMIC_TEST_AND_SET_TRUEVAL 1
#define __GCC_ATOMIC_WCHAR_T_LOCK_FREE 1
#define __GCC_IEC_559 0
#define __GCC_IEC_559_COMPLEX 0
#define __GNUC_MINOR__ 1
#define __GNUC_PATCHLEVEL__ 0
#define __GNUC_STDC_INLINE__ 1
#define __GNUC__ 8
#define __GXX_ABI_VERSION 1012
#define __HA_FBIT__ 7
#define __HA_IBIT__ 8
#define __HQ_FBIT__ 15
#define __HQ_IBIT__ 0
#define __INT16_C(c) c
#define __INT16_MAX__ 0x7fff
#define __INT16_TYPE__ int
#define __INT24_MAX__ 8388607L
#define __INT24_MIN__ (-__INT24_MAX__-1)
#define __INT32_C(c) c ## L
#define __INT32_MAX__ 0x7fffffffL
#define __INT32_TYPE__ long int
#define __INT64_C(c) c ## LL
#define __INT64_MAX__ 0x7fffffffffffffffLL
#define __INT64_TYPE__ long long int
#define __INT8_C(c) c
#define __INT8_MAX__ 0x7f
#define __INT8_TYPE__ signed char
#define __INTMAX_C(c) c ## LL
#define __INTMAX_MAX__ 0x7fffffffffffffffLL
#define __INTMAX_TYPE__ long long int
#define __INTMAX_WIDTH__ 64
#define __INTPTR_MAX__ 0x7fff
#define __INTPTR_TYPE__ int
#define __INTPTR_WIDTH__ 16
#define __INT_FAST16_MAX__ 0x7fff
#define __INT_FAST16_TYPE__ int
#define __INT_FAST16_WIDTH__ 16
#define __INT_FAST32_MAX__ 0x7fffffffL
#define __INT_FAST32_TYPE__ long int
#define __INT_FAST32_WIDTH__ 32
#define __INT_FAST64_MAX__ 0x7fffffffffffffffLL
#define __INT_FAST64_TYPE__ long long int
#define __INT_FAST64_WIDTH__ 64
#define __INT_FAST8_MAX__ 0x7f
#define __INT_FAST8_TYPE__ signed char
#define __INT_FAST8_WIDTH__ 8
#define __INT_LEAST16_MAX__ 0x7fff
#define __INT_LEAST16_TYPE__ int
#define __INT_LEAST16_WIDTH__ 16
#define __INT_LEAST32_MAX__ 0x7fffffffL
#define __INT_LEAST32_TYPE__ long int
#define __INT_LEAST32_WIDTH__ 32
#define __INT_LEAST64_MAX__ 0x7fffffffffffffffLL
#define __INT_LEAST64_TYPE__ long long int
#define __INT_LEAST64_WIDTH__ 64
#define __INT_LEAST8_MAX__ 0x7f
#define __INT_LEAST8_TYPE__ signed char
#define __INT_LEAST8_WIDTH__ 8
#define __INT_MAX__ 0x7fff
#define __INT_WIDTH__ 16
#define __LACCUM_EPSILON__ 0x1P-31LK
#define __LACCUM_FBIT__ 31
#define __LACCUM_IBIT__ 32
#define __LACCUM_MAX__ 0X7FFFFFFFFFFFFFFFP-31LK
#define __LACCUM_MIN__ (-0X1P31LK-0X1P31LK)
#define __LDBL_DECIMAL_DIG__ 9
#define __LDBL_DENORM_MIN__ 1.40129846e-45L
#define __LDBL_DIG__ 6
#define __LDBL_EPSILON__ 1.19209290e-7L
#define __LDBL_HAS_DENORM__ 1
#define __LDBL_HAS_INFINITY__ 1
#define __LDBL_HAS_QUIET_NAN__ 1
#define __LDBL_MANT_DIG__ 24
#define __LDBL_MAX_10_EXP__ 38
#define __LDBL_MAX_EXP__ 128
#define __LDBL_MAX__ 3.40282347e+38L
#define __LDBL_MIN_10_EXP__ (-37)
#define __LDBL_MIN_EXP__ (-125)
#define __LDBL_MIN__ 1.17549435e-38L
#define __LFRACT_EPSILON__ 0x1P-31LR
#define __LFRACT_FBIT__ 31
#define __LFRACT_IBIT__ 0
#define __LFRACT_MAX__ 0X7FFFFFFFP-31LR
#define __LFRACT_MIN__ (-0.5LR-0.5LR)
#define __LLACCUM_EPSILON__ 0x1P-47LLK
#define __LLACCUM_FBIT__ 47
#define __LLACCUM_IBIT__ 16
#define __LLACCUM_MAX__ 0X7FFFFFFFFFFFFFFFP-47LLK
#define __LLACCUM_MIN__ (-0X1P15LLK-0X1P15LLK)
#define __LLFRACT_EPSILON__ 0x1P-63LLR
#define __LLFRACT_FBIT__ 63
#define __LLFRACT_IBIT__ 0
#define __LLFRACT_MAX__ 0X7FFFFFFFFFFFFFFFP-63LLR
#define __LLFRACT_MIN__ (-0.5LLR-0.5LLR)
#define __LONG_LONG_MAX__ 0x7fffffffffffffffLL
#define __LONG_LONG_WIDTH__ 64
#define __LONG_MAX__ 0x7fffffffL
#define __LONG_WIDTH__ 32
#define __MEMX 1
#define __NO_INLINE__ 1
#define __ORDER_BIG_ENDIAN__ 4321
#define __ORDER_LITTLE_ENDIAN__ 1234
#define __ORDER_PDP_ENDIAN__ 3412
#define __PRAGMA_REDEFINE_EXTNAME 1
#define __PTRDIFF_MAX__ 0x7fff
#define __PTRDIFF_TYPE__ int
#define __PTRDIFF_WIDTH__ 16
#define __QQ_FBIT__ 7
#define __QQ_IBIT__ 0
#define __REGISTER_PREFIX__
#define __SACCUM_EPSILON__ 0x1P-7HK
#define __SACCUM_FBIT__ 7
#define __SACCUM_IBIT__ 8
#define __SACCUM_MAX__ 0X7FFFP-7HK
#define __SACCUM_MIN__ (-0X1P7HK-0X1P7HK)
#define __SA_FBIT__ 15
#define __SA_IBIT__ 16
#define __SCHAR_MAX__ 0x7f
#define __SCHAR_WIDTH__ 8
#define __SFRACT_EPSILON__ 0x1P-7HR
#define __SFRACT_FBIT__ 7
#define __SFRACT_IBIT__ 0
#define __SFRACT_MAX__ 0X7FP-7HR
#define __SFRACT_MIN__ (-0.5HR-0.5HR)
#define __SHRT_MAX__ 0x7fff
#define __SHRT_WIDTH__ 16
#define __SIG_ATOMIC_MAX__ 0x7f
#define __SIG_ATOMIC_MIN__ (-__SIG_ATOMIC_MAX__ - 1)
#define __SIG_ATOMIC_TYPE__ char
#define __SIG_ATOMIC_WIDTH__ 8
#define __SIZEOF_DOUBLE__ 4
#define __SIZEOF_FLOAT__ 4
#define __SIZEOF_INT__ 2
#define __SIZEOF_LONG_DOUBLE__ 4
#define __SIZEOF_LONG_LONG__ 8
#define __SIZEOF_LONG__ 4
#define __SIZEOF_POINTER__ 2
#define __SIZEOF_PTRDIFF_T__ 2
#define __SIZEOF_SHORT__ 2
#define __SIZEOF_SIZE_T__ 2
#define __SIZEOF_WCHAR_T__ 2
#define __SIZEOF_WINT_T__ 2
#define __SIZE_MAX__ 0xffffU
#define __SIZE_TYPE__ unsigned int
#define __SIZE_WIDTH__ 16
#define __SQ_FBIT__ 31
#define __SQ_IBIT__ 0
#define __STDC_HOSTED__ 1
#define __STDC_UTF_16__ 1
#define __STDC_UTF_32__ 1
#define __STDC_VERSION__ 201710L
#define __STDC__ 1
#define __TA_FBIT__ 47
#define __TA_IBIT__ 16
#define __TQ_FBIT__ 127
#define __TQ_IBIT__ 0
#define __UACCUM_EPSILON__ 0x1P-16UK
#define __UACCUM_FBIT__ 16
#define __UACCUM_IBIT__ 16
#define __UACCUM_MAX__ 0XFFFFFFFFP-16UK
#define __UACCUM_MIN__ 0.0UK
#define __UDA_FBIT__ 32
#define __UDA_IBIT__ 32
#define __UDQ_FBIT__ 64
#define __UDQ_IBIT__ 0
#define __UFRACT_EPSILON__ 0x1P-16UR
#define __UFRACT_FBIT__ 16
#define __UFRACT_IBIT__ 0
#define __UFRACT_MAX__ 0XFFFFP-16UR
#define __UFRACT_MIN__ 0.0UR
#define __UHA_FBIT__ 8
#define __UHA_IBIT__ 8
#define __UHQ_FBIT__ 16
#define __UHQ_IBIT__ 0
#define __UINT16_C(c) c ## U
#define __UINT16_MAX__ 0xffffU
#define __UINT16_TYPE__ unsigned int
#define __UINT24_MAX__ 16777215UL
#define __UINT32_C(c) c ## UL
#define __UINT32_MAX__ 0xffffffffUL
#define __UINT32_TYPE__ long unsigned int
#define __UINT64_C(c) c ## ULL
#define __UINT64_MAX__ 0xffffffffffffffffULL
#define __UINT64_TYPE__ long long unsigned int
#define __UINT8_C(c) c
#define __UINT8_MAX__ 0xff
#define __UINT8_TYPE__ unsigned char
#define __UINTMAX_C(c) c ## ULL
#define __UINTMAX_MAX__ 0xffffffffffffffffULL
#define __UINTMAX_TYPE__ long long unsigned int
#define __UINTPTR_MAX__ 0xffffU
#define __UINTPTR_TYPE__ unsigned int
#define __UINT_FAST16_MAX__ 0xffffU
#define __UINT_FAST16_TYPE__ unsigned int
#define __UINT_FAST32_MAX__ 0xffffffffUL
#define __UINT_FAST32_TYPE__ long unsigned int
#define __UINT_FAST64_MAX__ 0xffffffffffffffffULL
#define __UINT_FAST64_TYPE__ long long unsigned int
#define __UINT_FAST8_MAX__ 0xff
#define __UINT_FAST8_TYPE__ unsigned char
#define __UINT_LEAST16_MAX__ 0xffffU
#define __UINT_LEAST16_TYPE__ unsigned int
#define __UINT_LEAST32_MAX__ 0xffffffffUL
#define __UINT_LEAST32_TYPE__ long unsigned int
#define __UINT_LEAST64_MAX__ 0xffffffffffffffffULL
#define __UINT_LEAST64_TYPE__ long long unsigned int
#define __UINT_LEAST8_MAX__ 0xff
#define __UINT_LEAST8_TYPE__ unsigned char
#define __ULACCUM_EPSILON__ 0x1P-32ULK
#define __ULACCUM_FBIT__ 32
#define __ULACCUM_IBIT__ 32
#define __ULACCUM_MAX__ 0XFFFFFFFFFFFFFFFFP-32ULK
#define __ULACCUM_MIN__ 0.0ULK
#define __ULFRACT_EPSILON__ 0x1P-32ULR
#define __ULFRACT_FBIT__ 32
#define __ULFRACT_IBIT__ 0
#define __ULFRACT_MAX__ 0XFFFFFFFFP-32ULR
#define __ULFRACT_MIN__ 0.0ULR
#define __ULLACCUM_EPSILON__ 0x1P-48ULLK
#define __ULLACCUM_FBIT__ 48
#define __ULLACCUM_IBIT__ 16
#define __ULLACCUM_MAX__ 0XFFFFFFFFFFFFFFFFP-48ULLK
#define __ULLACCUM_MIN__ 0.0ULLK
#define __ULLFRACT_EPSILON__ 0x1P-64ULLR
#define __ULLFRACT_FBIT__ 64
#define __ULLFRACT_IBIT__ 0
#define __ULLFRACT_MAX__ 0XFFFFFFFFFFFFFFFFP-64ULLR
#define __ULLFRACT_MIN__ 0.0ULLR
#define __UQQ_FBIT__ 8
#define __UQQ_IBIT__ 0
#define __USACCUM_EPSILON__ 0x1P-8UHK
#define __USACCUM_FBIT__ 8
#define __USACCUM_IBIT__ 8
#define __USACCUM_MAX__ 0XFFFFP-8UHK
#define __USACCUM_MIN__ 0.0UHK
#define __USA_FBIT__ 16
#define __USA_IBIT__ 16
#define __USER_LABEL_PREFIX__
#define __USFRACT_EPSILON__ 0x1P-8UHR
#define __USFRACT_FBIT__ 8
#define __USFRACT_IBIT__ 0
#define __USFRACT_MAX__ 0XFFP-8UHR
#define __USFRACT_MIN__ 0.0UHR
#define __USING_SJLJ_EXCEPTIONS__ 1
#define __USQ_FBIT__ 32
#define __USQ_IBIT__ 0
#define __UTA_FBIT__ 48
#define __UTA_IBIT__ 16
#define __UTQ_FBIT__ 128
#define __UTQ_IBIT__ 0
#define __VERSION__ "8.1.0"
#define __WCHAR_MAX__ 0x7fff
#define __WCHAR_MIN__ (-__WCHAR_MAX__ - 1)
#define __WCHAR_TYPE__ int
#define __WCHAR_WIDTH__ 16
#define __WINT_MAX__ 0xffffU
#define __WINT_MIN__ 0U
#define __WINT_TYPE__ unsigned int
#define __WINT_WIDTH__ 16
#define __WITH_AVRLIBC__ 1
#define __has_include(STR) __has_include__(STR)
#define __has_include_next(STR) __has_include_next__(STR)

Andreas · February 16, 2019, 5:50pm

`xtensa-gcc`

We conclude from the following summary that "#ifdef __XTENSA__" resp. "#if defined(__XTENSA__)" would be the right thing to check for the Xtensa target.

xtensa-lx106-elf-gcc -dM -E

xtensa-lx106-elf-gcc -dM -E - < /dev/null | sort | uniq

#define __ATOMIC_ACQ_REL 4
#define __ATOMIC_ACQUIRE 2
#define __ATOMIC_CONSUME 1
#define __ATOMIC_RELAXED 0
#define __ATOMIC_RELEASE 3
#define __ATOMIC_SEQ_CST 5
#define __BIGGEST_ALIGNMENT__ 16
#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
#define __CHAR16_TYPE__ short unsigned int
#define __CHAR32_TYPE__ long unsigned int
#define __CHAR_BIT__ 8
#define __CHAR_UNSIGNED__ 1
#define __DBL_DECIMAL_DIG__ 17
#define __DBL_DENORM_MIN__ ((double)4.9406564584124654e-324L)
#define __DBL_DIG__ 15
#define __DBL_EPSILON__ ((double)2.2204460492503131e-16L)
#define __DBL_HAS_DENORM__ 1
#define __DBL_HAS_INFINITY__ 1
#define __DBL_HAS_QUIET_NAN__ 1
#define __DBL_MANT_DIG__ 53
#define __DBL_MAX_10_EXP__ 308
#define __DBL_MAX__ ((double)1.7976931348623157e+308L)
#define __DBL_MAX_EXP__ 1024
#define __DBL_MIN_10_EXP__ (-307)
#define __DBL_MIN__ ((double)2.2250738585072014e-308L)
#define __DBL_MIN_EXP__ (-1021)
#define __DEC128_EPSILON__ 1E-33DL
#define __DEC128_MANT_DIG__ 34
#define __DEC128_MAX__ 9.999999999999999999999999999999999E6144DL
#define __DEC128_MAX_EXP__ 6145
#define __DEC128_MIN__ 1E-6143DL
#define __DEC128_MIN_EXP__ (-6142)
#define __DEC128_SUBNORMAL_MIN__ 0.000000000000000000000000000000001E-6143DL
#define __DEC32_EPSILON__ 1E-6DF
#define __DEC32_MANT_DIG__ 7
#define __DEC32_MAX__ 9.999999E96DF
#define __DEC32_MAX_EXP__ 97
#define __DEC32_MIN__ 1E-95DF
#define __DEC32_MIN_EXP__ (-94)
#define __DEC32_SUBNORMAL_MIN__ 0.000001E-95DF
#define __DEC64_EPSILON__ 1E-15DD
#define __DEC64_MANT_DIG__ 16
#define __DEC64_MAX__ 9.999999999999999E384DD
#define __DEC64_MAX_EXP__ 385
#define __DEC64_MIN__ 1E-383DD
#define __DEC64_MIN_EXP__ (-382)
#define __DEC64_SUBNORMAL_MIN__ 0.000000000000001E-383DD
#define __DEC_EVAL_METHOD__ 2
#define __DECIMAL_DIG__ 17
#define __ELF__ 1
#define __FINITE_MATH_ONLY__ 0
#define __FLOAT_WORD_ORDER__ __ORDER_LITTLE_ENDIAN__
#define __FLT_DECIMAL_DIG__ 9
#define __FLT_DENORM_MIN__ 1.4012984643248171e-45F
#define __FLT_DIG__ 6
#define __FLT_EPSILON__ 1.1920928955078125e-7F
#define __FLT_EVAL_METHOD__ 0
#define __FLT_HAS_DENORM__ 1
#define __FLT_HAS_INFINITY__ 1
#define __FLT_HAS_QUIET_NAN__ 1
#define __FLT_MANT_DIG__ 24
#define __FLT_MAX_10_EXP__ 38
#define __FLT_MAX__ 3.4028234663852886e+38F
#define __FLT_MAX_EXP__ 128
#define __FLT_MIN_10_EXP__ (-37)
#define __FLT_MIN__ 1.1754943508222875e-38F
#define __FLT_MIN_EXP__ (-125)
#define __FLT_RADIX__ 2
#define __GCC_ATOMIC_BOOL_LOCK_FREE 1
#define __GCC_ATOMIC_CHAR16_T_LOCK_FREE 1
#define __GCC_ATOMIC_CHAR32_T_LOCK_FREE 1
#define __GCC_ATOMIC_CHAR_LOCK_FREE 1
#define __GCC_ATOMIC_INT_LOCK_FREE 1
#define __GCC_ATOMIC_LLONG_LOCK_FREE 1
#define __GCC_ATOMIC_LONG_LOCK_FREE 1
#define __GCC_ATOMIC_POINTER_LOCK_FREE 1
#define __GCC_ATOMIC_SHORT_LOCK_FREE 1
#define __GCC_ATOMIC_TEST_AND_SET_TRUEVAL 1
#define __GCC_ATOMIC_WCHAR_T_LOCK_FREE 1
#define __GNUC__ 4
#define __GNUC_GNU_INLINE__ 1
#define __GNUC_MINOR__ 8
#define __GNUC_PATCHLEVEL__ 2
#define __GXX_ABI_VERSION 1002
#define __INT16_C(c) c
#define __INT16_MAX__ 32767
#define __INT16_TYPE__ short int
#define __INT32_C(c) c ## L
#define __INT32_MAX__ 2147483647L
#define __INT32_TYPE__ long int
#define __INT64_C(c) c ## LL
#define __INT64_MAX__ 9223372036854775807LL
#define __INT64_TYPE__ long long int
#define __INT8_C(c) c
#define __INT8_MAX__ 127
#define __INT8_TYPE__ signed char
#define __INT_FAST16_MAX__ 2147483647
#define __INT_FAST16_TYPE__ int
#define __INT_FAST32_MAX__ 2147483647
#define __INT_FAST32_TYPE__ int
#define __INT_FAST64_MAX__ 9223372036854775807LL
#define __INT_FAST64_TYPE__ long long int
#define __INT_FAST8_MAX__ 2147483647
#define __INT_FAST8_TYPE__ int
#define __INT_LEAST16_MAX__ 32767
#define __INT_LEAST16_TYPE__ short int
#define __INT_LEAST32_MAX__ 2147483647L
#define __INT_LEAST32_TYPE__ long int
#define __INT_LEAST64_MAX__ 9223372036854775807LL
#define __INT_LEAST64_TYPE__ long long int
#define __INT_LEAST8_MAX__ 127
#define __INT_LEAST8_TYPE__ signed char
#define __INT_MAX__ 2147483647
#define __INTMAX_C(c) c ## LL
#define __INTMAX_MAX__ 9223372036854775807LL
#define __INTMAX_TYPE__ long long int
#define __INTPTR_MAX__ 2147483647
#define __INTPTR_TYPE__ int
#define __LDBL_DENORM_MIN__ 4.9406564584124654e-324L
#define __LDBL_DIG__ 15
#define __LDBL_EPSILON__ 2.2204460492503131e-16L
#define __LDBL_HAS_DENORM__ 1
#define __LDBL_HAS_INFINITY__ 1
#define __LDBL_HAS_QUIET_NAN__ 1
#define __LDBL_MANT_DIG__ 53
#define __LDBL_MAX_10_EXP__ 308
#define __LDBL_MAX__ 1.7976931348623157e+308L
#define __LDBL_MAX_EXP__ 1024
#define __LDBL_MIN_10_EXP__ (-307)
#define __LDBL_MIN__ 2.2250738585072014e-308L
#define __LDBL_MIN_EXP__ (-1021)
#define __LONG_LONG_MAX__ 9223372036854775807LL
#define __LONG_MAX__ 2147483647L
#define __NO_INLINE__ 1
#define __ORDER_BIG_ENDIAN__ 4321
#define __ORDER_LITTLE_ENDIAN__ 1234
#define __ORDER_PDP_ENDIAN__ 3412
#define __PRAGMA_REDEFINE_EXTNAME 1
#define __PTRDIFF_MAX__ 2147483647
#define __PTRDIFF_TYPE__ int
#define __REGISTER_PREFIX__
#define __SCHAR_MAX__ 127
#define __SHRT_MAX__ 32767
#define __SIG_ATOMIC_MAX__ 2147483647
#define __SIG_ATOMIC_MIN__ (-__SIG_ATOMIC_MAX__ - 1)
#define __SIG_ATOMIC_TYPE__ int
#define __SIZE_MAX__ 4294967295U
#define __SIZEOF_DOUBLE__ 8
#define __SIZEOF_FLOAT__ 4
#define __SIZEOF_INT__ 4
#define __SIZEOF_LONG__ 4
#define __SIZEOF_LONG_DOUBLE__ 8
#define __SIZEOF_LONG_LONG__ 8
#define __SIZEOF_POINTER__ 4
#define __SIZEOF_PTRDIFF_T__ 4
#define __SIZEOF_SHORT__ 2
#define __SIZEOF_SIZE_T__ 4
#define __SIZEOF_WCHAR_T__ 2
#define __SIZEOF_WINT_T__ 4
#define __SIZE_TYPE__ unsigned int
#define __STDC__ 1
#define __STDC_HOSTED__ 1
#define __UINT16_C(c) c
#define __UINT16_MAX__ 65535
#define __UINT16_TYPE__ short unsigned int
#define __UINT32_C(c) c ## UL
#define __UINT32_MAX__ 4294967295UL
#define __UINT32_TYPE__ long unsigned int
#define __UINT64_C(c) c ## ULL
#define __UINT64_MAX__ 18446744073709551615ULL
#define __UINT64_TYPE__ long long unsigned int
#define __UINT8_C(c) c
#define __UINT8_MAX__ 255
#define __UINT8_TYPE__ unsigned char
#define __UINT_FAST16_MAX__ 4294967295U
#define __UINT_FAST16_TYPE__ unsigned int
#define __UINT_FAST32_MAX__ 4294967295U
#define __UINT_FAST32_TYPE__ unsigned int
#define __UINT_FAST64_MAX__ 18446744073709551615ULL
#define __UINT_FAST64_TYPE__ long long unsigned int
#define __UINT_FAST8_MAX__ 4294967295U
#define __UINT_FAST8_TYPE__ unsigned int
#define __UINT_LEAST16_MAX__ 65535
#define __UINT_LEAST16_TYPE__ short unsigned int
#define __UINT_LEAST32_MAX__ 4294967295UL
#define __UINT_LEAST32_TYPE__ long unsigned int
#define __UINT_LEAST64_MAX__ 18446744073709551615ULL
#define __UINT_LEAST64_TYPE__ long long unsigned int
#define __UINT_LEAST8_MAX__ 255
#define __UINT_LEAST8_TYPE__ unsigned char
#define __UINTMAX_C(c) c ## ULL
#define __UINTMAX_MAX__ 18446744073709551615ULL
#define __UINTMAX_TYPE__ long long unsigned int
#define __UINTPTR_MAX__ 4294967295U
#define __UINTPTR_TYPE__ unsigned int
#define __USER_LABEL_PREFIX__
#define __VERSION__ "4.8.2"
#define __WCHAR_MAX__ 65535
#define __WCHAR_MIN__ 0
#define __WCHAR_TYPE__ short unsigned int
#define __WINT_MAX__ 4294967295U
#define __WINT_MIN__ 0U
#define __WINT_TYPE__ unsigned int
#define __xtensa__ 1
#define __XTENSA__ 1
#define __XTENSA_CALL0_ABI__ 1
#define __XTENSA_EL__ 1
#define __XTENSA_SOFT_FLOAT__ 1

Andreas · February 16, 2019, 7:18pm

`arm-gcc`

Todo.

Andreas · February 17, 2019, 5:43am

Just a quick note about how to tell an ESP8266 and an ESP32 apart:

#if defined(ARDUINO_ARCH_ESP8266) || defined(ARDUINO_ARCH_ESP32)

– Correct preprocessor directive syntax by per1234 · Pull Request #10 · sparkfun/SparkFun_CCS811_Arduino_Library · GitHub