Show widths of standard integer types when C23 x_WIDTH macros not available

intwidth.c

#include <limits.h>
#include <stdint.h>

/* Number of bits in inttype_MAX, or in any (1<<k)-1 where 0 <= k < 2040 */
/* (Attributed to Hallvard B. Furuseth.) */
#define IMAX_BITS(m) ((m)/((m)%255+1) / 255%255*8 + 7-86/((m)%255+12))

/* Helper macros. */
#define MY___WIDTH(x)           IMAX_BITS(x##_MAX)
#define MY__U__WIDTH(x)         MY___WIDTH(U##x)

/*
 * Note: the type of the MY_xxx_WIDTH constants defined below
 * might not be `int`, so be careful when using them where default argument
 * promotions are in effect because they may need an explicit type conversion
 * (type cast).  However, they do have the advantage of being usable in
 * constant expressions for preprocessor `#if` and `#elif` directives.
 */
#define MY_BOOL_WIDTH           1

#define MY_SHRT_WIDTH           MY__U__WIDTH(SHRT)
#define MY_USHRT_WIDTH          MY__U__WIDTH(SHRT)
#define MY_INT_WIDTH            MY__U__WIDTH(INT)
#define MY_UINT_WIDTH           MY__U__WIDTH(INT)
#define MY_LONG_WIDTH           MY__U__WIDTH(LONG)
#define MY_ULONG_WIDTH          MY__U__WIDTH(LONG)
#define MY_LLONG_WIDTH          MY__U__WIDTH(LLONG)
#define MY_ULLONG_WIDTH         MY__U__WIDTH(LLONG)

#ifdef INT8_MAX
#define MY_INT8_WIDTH           8
#define MY_UINT8_WIDTH          8
#endif

#ifdef INT16_MAX
#define MY_INT16_WIDTH          16
#define MY_UINT16_WIDTH         16
#endif

#ifdef INT32_MAX
#define MY_INT32_WIDTH          32
#define MY_UINT32_WIDTH         32
#endif

#ifdef INT64_MAX
#define MY_INT64_WIDTH          64
#define MY_UINT64_WIDTH         64
#endif

#define MY_INT_LEAST8_WIDTH     MY__U__WIDTH(INT_LEAST8)
#define MY_UINT_LEAST8_WIDTH    MY__U__WIDTH(INT_LEAST8)
#define MY_INT_LEAST16_WIDTH    MY__U__WIDTH(INT_LEAST16)
#define MY_UINT_LEAST16_WIDTH   MY__U__WIDTH(INT_LEAST16)
#define MY_INT_LEAST32_WIDTH    MY__U__WIDTH(INT_LEAST32)
#define MY_UINT_LEAST32_WIDTH   MY__U__WIDTH(INT_LEAST32)
#define MY_INT_LEAST64_WIDTH    MY__U__WIDTH(INT_LEAST64)
#define MY_UINT_LEAST64_WIDTH   MY__U__WIDTH(INT_LEAST64)

#define MY_INT_FAST8_WIDTH      MY__U__WIDTH(INT_FAST8)
#define MY_UINT_FAST8_WIDTH     MY__U__WIDTH(INT_FAST8)
#define MY_INT_FAST16_WIDTH     MY__U__WIDTH(INT_FAST16)
#define MY_UINT_FAST16_WIDTH    MY__U__WIDTH(INT_FAST16)
#define MY_INT_FAST32_WIDTH     MY__U__WIDTH(INT_FAST32)
#define MY_UINT_FAST32_WIDTH    MY__U__WIDTH(INT_FAST32)
#define MY_INT_FAST64_WIDTH     MY__U__WIDTH(INT_FAST64)
#define MY_UINT_FAST64_WIDTH    MY__U__WIDTH(INT_FAST64)

#define MY_INTPTR_WIDTH         MY__U__WIDTH(INTPTR)
#define MY_UINTPTR_WIDTH        MY__U__WIDTH(INTPTR)

#define MY_INTMAX_WIDTH         MY__U__WIDTH(INTMAX)
#define MY_UINTMAX_WIDTH        MY__U__WIDTH(INTMAX)

#define MY_PTRDIFF_WIDTH        (MY___WIDTH(PTRDIFF) + 1)

#if SIG_ATOMIC_MIN
#define MY_SIG_ATOMIC_WIDTH     (MY___WIDTH(SIG_ATOMIC) + 1)
#else
#define MY_SIG_ATOMIC_WIDTH     MY___WIDTH(SIG_ATOMIC)
#endif

#define MY_SIZE_WIDTH           MY___WIDTH(SIZE)

#if WCHAR_MIN
#define MY_WCHAR_WIDTH          (MY___WIDTH(WCHAR) + 1)
#else
#define MY_WCHAR_WIDTH          MY___WIDTH(WCHAR)
#endif

#if WINT_MIN
#define MY_WINT_WIDTH           (MY___WIDTH(WINT) + 1)
#else
#define MY_WINT_WIDTH           MY___WIDTH(WINT)
#endif


#include <stdio.h>

#define PRINT(name) printf("%s = %d\n", #name, (int)name);

int main(void)
{
    PRINT(MY_BOOL_WIDTH);
    PRINT(MY_SHRT_WIDTH);
    PRINT(MY_USHRT_WIDTH);
    PRINT(MY_INT_WIDTH);
    PRINT(MY_UINT_WIDTH);
    PRINT(MY_LONG_WIDTH);
    PRINT(MY_ULONG_WIDTH);
    PRINT(MY_LLONG_WIDTH);
    PRINT(MY_ULLONG_WIDTH);
#ifdef INT8_MAX
    PRINT(MY_INT8_WIDTH);
    PRINT(MY_UINT8_WIDTH);
#endif
#ifdef INT16_MAX
    PRINT(MY_INT16_WIDTH);
    PRINT(MY_UINT16_WIDTH);
#endif
#ifdef INT32_MAX
    PRINT(MY_INT32_WIDTH);
    PRINT(MY_UINT32_WIDTH);
#endif
#ifdef INT64_MAX
    PRINT(MY_INT64_WIDTH);
    PRINT(MY_UINT64_WIDTH);
#endif
    PRINT(MY_INT_LEAST8_WIDTH);
    PRINT(MY_UINT_LEAST8_WIDTH);
    PRINT(MY_INT_LEAST16_WIDTH);
    PRINT(MY_UINT_LEAST16_WIDTH);
    PRINT(MY_INT_LEAST32_WIDTH);
    PRINT(MY_UINT_LEAST32_WIDTH);
    PRINT(MY_INT_LEAST64_WIDTH);
    PRINT(MY_UINT_LEAST64_WIDTH);
    PRINT(MY_INT_FAST8_WIDTH);
    PRINT(MY_UINT_FAST8_WIDTH);
    PRINT(MY_INT_FAST16_WIDTH);
    PRINT(MY_UINT_FAST16_WIDTH);
    PRINT(MY_INT_FAST32_WIDTH);
    PRINT(MY_UINT_FAST32_WIDTH);
    PRINT(MY_INT_FAST64_WIDTH);
    PRINT(MY_UINT_FAST64_WIDTH);
    PRINT(MY_INTPTR_WIDTH);
    PRINT(MY_UINTPTR_WIDTH);
    PRINT(MY_INTMAX_WIDTH);
    PRINT(MY_UINTMAX_WIDTH);
    PRINT(MY_PTRDIFF_WIDTH);
    PRINT(MY_SIG_ATOMIC_WIDTH);
    PRINT(MY_SIZE_WIDTH);
    PRINT(MY_WCHAR_WIDTH);
    PRINT(MY_WINT_WIDTH);
    return 0;
}