[MinGW32] missing timespec_get()

[gvanem]

Trying to build for MinGW with the minimal features possible:

cmake -G "MinGW Makefiles" -DWITH_XML_BACKEND=0 -DWITH_SERIAL_BACKEND=0 -DWITH_USB_BACKEND=0 -DENABLE_IPV6=0 -DPYTHON_BINDINGS=0 -DWITH_NETWORK_BACKEND=0 ..

Yields:

F:\gv\dx-radio\libiio\tests\iio_common.c: In function 'get_time_us':
F:\gv\dx-radio\libiio\tests\iio_common.c:455:2: warning: implicit declaration of function 'timespec_get'
[-Wimplicit-function-declaration]
  455 |  timespec_get(&tp, TIME_UTC);
      |  ^~~~~~~~~~~~
F:\gv\dx-radio\libiio\tests\iio_common.c:455:20: error: 'TIME_UTC' undeclared (first use in this function)
  455 |  timespec_get(&tp, TIME_UTC);
      |                    ^~~~~~~~

My MinGW (TDM / gcc version 10.3.0) do have an inlined clock_gettime() in it's <pthread_time.h>
(which gets included in <time.h> for _POSIX_C_SOURCE > 2).
But inlined only for __MINGW64__! So I tried this patch:

--- a/tests/iio_common.c 2022-04-04 10:17:44
+++ b/tests/iio_common.c 2022-04-06 10:59:46
@@ -451,7 +451,9 @@
 {
        struct timespec tp;

-#ifdef _WIN32
+#if defined(__MINGW32__)
+       __pthread_clock_gettime(CLOCK_REALTIME, &tp);
+#elif defined(_WIN32)
        timespec_get(&tp, TIME_UTC);
 #else
        clock_gettime(CLOCK_REALTIME, &tp);

The above compiles and links for both -DBUILD_SHARED_LIBS=0 and -DBUILD_SHARED_LIBS=1.

[pcercuei]

Since you say that your MinGW does have clock_gettime(), why not:

#if defined(_WIN32) && !defined(__MINGW32__)
    timespec_get(&tp, TIME_UTC);
#else
    clock_gettime(CLOCK_REALTIME, &tp);
#endif

[gvanem]

But it is inlined only for __MINGW64__ / x64; excluding 32-bit targets.
But this issue is really not important for me. I've abandoned MinGW some years ago due to such messy issues.
So feel free to close or fix at own will.

[gvanem]

Besides your CMakeLists.txt is really not for x86 on MINGW (-m32) at all.
How does this hellish Cmake system choose to build 32-bit targets?

[pcercuei]

Besides your CMakeLists.txt is really not for x86 on MINGW (-m32) at all. How does this hellish Cmake system choose to build 32-bit targets?

Easy - just use a 32-bit MinGW toolchain :)