- cmake: fix compiler warnings in `CheckNonblockingSocketSupport`.
detection functions.
Without this, these detections fail when `ENABLE_WERROR=ON`.
- cmake: disable ENABLE_WERROR for MSVC during symbol checks in `src`.
CMake's built-in symbol check function `check_symbol_exists()`
generate warnings with MSVC. With warnings considered errors, these
detections fail permanently. Our workaround is to disable
warnings-as-errors while running these checks.
```
CheckSymbolExists.c(8): warning C4054: 'type cast': from function pointer '__int64 (__cdecl *)(const char *,char **,int)' to data pointer 'int *'
in `return ((int*)(&strtoll))[argc];`
```
Ref: https://ci.appveyor.com/project/libssh2org/libssh2/builds/46537222/job/4vg4yg333mu2lg9b
- example: replace `strcasecmp()` with C89 `strcmp()`.
To avoid using CMake symbol checks in `example`.
Another option is to duplicate the `check_symbol_exists()` workaround
from `src`, but I figure it's not worth the complexity. We use
`strcasecmp()` solely to check optional command-line options for
example programs, and those are fine as lower-case.
Without this, these detections fail when `ENABLE_WERROR=ON`.
- also delete `__function__` detection/use in `example`.
To avoid the complexity for the sake of using it at a single place in
of the example's error branch. Replace that use with a literal name of
the function.
- cmake: also use `CMakePushCheckState` functions instead of manual
save/restore.
Closes#857
Before this patch, the `snprintf()` fallback logic for envs not
supporting this function (i.e. Visual Studio 2013 and older) varied
depending on build tool, and used different techniques in examples,
tests and libssh2 itself.
This patch aims to apply a common logic to libssh2 and examples/tests.
- libssh2: use local `snprintf()` fallback with all build tools.
We already had a local implementation, but only with CMake. Move that
to the library as `_libssh2_snprintf()`, and map `snprintf()` to it
when `HAVE_SNPRINTF` is not set.
Also change the length type from `int` to `size_t`, and fix
formatting.
- set or detect `HAVE_SNPRINTF` in non-CMake builds.
Detect in autotools. Keep existing logic in `win32/libssh2_config.h`.
Always set for OS/400, NetWare and VMS, keeping existing behaviour.
(OS/400 builds use a different local implementation)
- examples/tests: drop the CMake-specific fallback logic and map
`snprintf()` to `_snprintf()` for old MSVC versions, like we did
before with other build tools. This is unsafe, but should be fine for
these uses.
- `win32/libssh2_config.h`: make it easier to read.
Closes#812
