Almost all feature detection results are pre-filled on Windows
for performance, so none of the issues fixed here affected builds.
For good measure, this patch add missing detections and fixes others
to make sure they work even when omitting the pre-fill.
It also fixes detecting IPv6 for MS-DOS.
- fix `HAVE_STRUCT_TIMEVAL` detection for MSVC.
Follow-up to c1bc090d65#12495
- add `HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID` detection for Windows.
- fix `HAVE_STRDUP` detection for MSVC.
- fix `HAVE_SNPRINTF` detection for Windows.
Regression from 8e34505776#15164
- fix `HAVE_IOCTLSOCKET` detection for non-UWP MSVC.
- exclude `if_nametoindex` detection for Windows.
Although it exists on Windows, detection, usage and availability is
complicated, and curl doesn't use it on this platform.
Regression from 8e34505776#15164
- move IPv6 detections so that pre-filling and MS-DOS Watt-32
configuration applies to them. This fixes
`HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID` detection with MS-DOS.
Ref: https://github.com/curl/curl/actions/runs/13260511764/job/37015877585#step:7:306
Follow-up to a3585c9576#15543
Also:
- add debug option to test without pre-filling.
- replace `NOT LESS` with `GREATER_EQUAL`
Closes#16278
On Windows a successful `sched_yield()` detection requires mingw-w64
built with POSIX threads (not Win32 threads) and GCC (not llvm/clang).
(linking to `winpthread` via custom options may also work.)
In CMake builds, it was pre-cached as unavailable before this patch.
When detected (via autotools), it got only used for Windows XP or older
targets combined with a non-GCC, non-clang compiler that doesn't support
`__builtin_ia32_pause()`, or with the Intel C compiler. According to
`lib/easy_lock.h`.
mingw-w64 only supports GCC and clang, leaving a very narrow chance when
`shed_yield()` gets called on Windows. Even then, `sched_yield()` is
implemented in `winpthread` as `Sleep(0)`, which may or not be a useful.
It's also trivial to implement locally if it is, and such rare build
combination is also deemed useful.
Thus, this patch marks `sched_yields()` permanently unavailable on the
Windows platform also with autotools, and instead of pre-caching, skip
this feature check with CMake.
This syncs `HAVE_SCHED_YIELDS` between builds methods on Windows.
Follow-up to 9b517c8b69#11973
Follow-up to 23af112f55#8680Closes#16037
Replace `strtok_r()` detection with detection mingw-w64 version.
The use this version to pre-fill `HAVE_STRTOK_R`.
This gives use mingw-w64 version information for free.
Closes#16022
`stdatomic.h` and `_Atomic` were first available in gcc 4.9.0 and
llvm/clang 3.6. Set detection values accordingly and save these two
detections on configure runs.
Closes#16036
- cmake: add auto-detection. Sync this with autotools.
- enable for MS-DOS and AmigaOS builds.
(auto-detection doesn't work for cross-builds.)
- tidy up detection snippet.
- fix comment.
Closes#15868
