Comment by debugnik
3 months ago
How can anyone be this interested in maintaining an annex k implementation when it's widely regarded as a design failure, specially the global constraint handler. There's a reason why most C toolchains don't support it.
It's only regarded as design failure by the linux folks. Maybe because it came from Microsoft, NIH syndrome.
A global constraint handler is still by far better than dynamic env handlers, and most of the existing libc/POSIX design failures.
You can disable this global constraint handler btw.
> Maybe because it came from Microsoft, NIH syndrome.
No it is because you still need to get the size calculation correct, so it doesn't actually have any benefit over the strn... family other than being different.
Also a memcpy that can fail at runtime, seems to be only complicating things. If anything it should fail at compile time.
If the optimizer cannot see the sizes, it has to defer the error to run-time. If it sees it (as with _FORTIFY_SOURCE=3) it fails at compile0-time already. The difference to _FORTIFY_SOURCE is that it guarantees to fail, whereas with _FORTIFY_SOURCE you never know.
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Microsoft doesn't implement Annex K, either. They ship an non-conforming implementation. Literally no one cares about the "standardized" Annex K version.
FWIW, it's heavily used inside Microsoft and is actually pretty nice when combined with all the static analysis tools that are mandatory parts of the dev cycle.
AFAIK Microsoft's API is still a previous iteration not compliant with the standard annex K.
## Microsoft Windows/MINGW_HAS_SECURE_API
* `fopen_s`, `freopen_s` deviate in the API: restrict is missing.
* `strtok_s`, `wcstok_s`,`vsnprintf_s` miss the dmax argument.
* `vsnprintf_s` adds a maxarg argument.
* `vswprintf` adds a maxarg argument on w32. (with `__STRICT_ANSI__` undefined)
* no `strnlen` on mingw32.
* no `errno_t` return type for `qsort_s`, only `void`.
* reversed argument order for `localtime_s` and `gmtime_s`.
* older mingw versions have `wchar.h` with only 2 functions: `wcscmp`, `wcslen`
* no `RSIZE_MAX`
* `memmove_s` does not clear dest with ERANGE when `count > dmax` and EINVAL when src is a NULL pointer.
* `vsprintf_s`, `sprintf_s` return `-1` on all errors, not just encoding errors. (Wrong standard)
* With `wcsrtombs` (used by `wcsrtomb_s`) the `retval` result includes the terminating zero, i.e. the result is `+1` from the spec.
`getenv_s` returns in len the size of the env buffer, not the len, as described in the standard (https://en.cppreference.com/w/c/program/getenv). The Microsoft size is len + 1. Their usage example is also wrong: https://learn.microsoft.com/en-us/cpp/c-runtime-library/refe...