while using "l" unconditionally gave the right behavior due to
matching sizes/representations, it was technically UB and produced
compiler warnings with format string checking.
somehow I missed this when removing the corresponding
__STDC_LIMIT_MACROS and __STDC_CONSTANT_MACROS nonsense from stdint.h.
these were all attempts by the C committee to guess what the C++
committee would want, and the guesses turned out to be wrong.
most importantly, the format/scan macros for the [u]int_fast16_t and
[u]int_fast32_t types were defined incorrectly assuming these types
would match the native word/pointer size. this is incorrect on any
64-bit system; the "fast" types for 16- and 32-bit integers are simply
int.
another issue which was "only a warning" (despite being UB) is that
the choice of "l" versus "ll" was incorrect for 64-bit types on 64-bit
machines. while it would "work" to always use "long long" for 64-bit
types, we use "long" on 64-bit machines to match what glibc does and
what the ABI documents recommend. the macro definitions were probably
right in very old versions of musl, but became wrong when we aligned
most closely with the 'standard' ABI. checking UINTPTR_MAX is an easy
way to get the system wordsize without pulling in new headers.
finally, the useless __PRIPTR macro to allow the underlying type of
[u]intptr_t to vary has been removed. we are using "long" on all
targets, and thankfully this matches what glibc does, so I do not
envision ever needing to change it. thus, the "l" has just been
incorporated directly in the strings.
to deal with the fact that the public headers may be used with pre-c99
compilers, __restrict is used in place of restrict, and defined
appropriately for any supported compiler. we also avoid the form
[restrict] since older versions of gcc rejected it due to a bug in the
original c99 standard, and instead use the form *restrict.
Rich Felker