Properly check for struct timespec

CMakeLists.txt

@@ -23,6 +23,7 @@ INCLUDE(CheckSymbolExists)
 INCLUDE(CheckCCompilerFlag)
 INCLUDE(CheckCSourceCompiles)
 INCLUDE(CheckTypeSize)
+include(CheckStructHasMember)
 include(CheckFileOffsetBits)
 include(GNUInstallDirs)
 
@@ -178,6 +179,13 @@ IF(CMAKE_COMPILER_IS_GNUCC)
     SET(CMAKE_REQUIRED_FLAGS "${OLD_REQUIRED_FLAGS}")
 ENDIF()
 
+# Check if we have a proper timespec declaration
+CHECK_STRUCT_HAS_MEMBER("struct timespec" tv_sec time.h HAVE_STRUCT_TIMESPEC)
+IF(HAVE_STRUCT_TIMESPEC)
+    # Define it here so we don't have to include config.h for it
+    ADD_DEFINITIONS("-DHAVE_STRUCT_TIMESPEC")
+ENDIF()
+
 # Some systems may need libatomic for C11 atomic functions to work
 SET(OLD_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
 SET(CMAKE_REQUIRED_LIBRARIES ${OLD_REQUIRED_LIBRARIES} atomic)

include/threads.h

@@ -33,17 +33,11 @@ typedef void (*altss_dtor_t)(void*);
 #include <windows.h>
 
 
-#if !defined(_TIMESPEC_DEFINED) && !(defined(_MSC_VER) && (_MSC_VER >= 1900))
-#define _TIMESPEC_DEFINED
+#ifndef HAVE_STRUCT_TIMESPEC
 struct timespec {
     time_t tv_sec;
     long tv_nsec;
 };
-
-struct itimerspec {
-    struct timespec it_interval;
-    struct timespec it_value;
-};
 #endif
 
 typedef DWORD althrd_t;