Fix build on msys2 mingw64

Something changed over night with pthread and `nanosleep()` in msys2
causing build failure for Shotcut CI. The ugly thing about it is that
pthread must be manually linked in a manner unknown by CMake's
FindThreads module. My workaround uses CMake `string()` over the iconv
lib until someone finds a better way because there is no (win)pthread
for pkg-config.

Author: ddennedy

.gitignore

@@ -67,4 +67,5 @@ src/modules/glaxnimate/mltglaxnimate-qt6_autogen/
 out
 src/swig/ruby/markdown/
 CMakeLists.txt.user
+.cache/
 

CMakeLists.txt

@@ -183,6 +183,9 @@ if(WIN32)
     find_package(dlfcn-win32 REQUIRED)
     set(CMAKE_DL_LIBS dlfcn-win32::dl)
   endif()
+  if(MINGW)
+    string(REPLACE "iconv" "pthread" MLT_PTHREAD_LIBS "${Iconv_LIBRARY}")
+  endif()
 endif()
 
 pkg_check_modules(sdl2 IMPORTED_TARGET sdl2)

src/framework/CMakeLists.txt

@@ -96,6 +96,7 @@ set_target_properties(mlt PROPERTIES
 
 if(WIN32)
   if(MINGW)
+    target_link_libraries(mlt PRIVATE ${MLT_PTHREAD_LIBS})
     target_link_options(mlt PRIVATE -Wl,--output-def,${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/libmlt-${MLT_VERSION_MAJOR}.def)
     install(FILES "${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/libmlt-${MLT_VERSION_MAJOR}.def" DESTINATION ${CMAKE_INSTALL_LIBDIR})
   endif()

src/framework/mlt_types.h

@@ -2,7 +2,7 @@
  * \file mlt_types.h
  * \brief Provides forward definitions of all public types
  *
- * Copyright (C) 2003-2023 Meltytech, LLC
+ * Copyright (C) 2003-2025 Meltytech, LLC
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -22,10 +22,6 @@
 #ifndef MLT_TYPES_H
 #define MLT_TYPES_H
 
-#ifndef GCC_VERSION
-#define GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__)
-#endif
-
 #ifdef __cplusplus
 extern "C" {
 #endif

src/melt/CMakeLists.txt

@@ -10,6 +10,7 @@ if(TARGET PkgConfig::sdl2 AND NOT ANDROID)
     target_link_libraries(melt PRIVATE PkgConfig::sdl2)
     target_compile_definitions(melt PRIVATE HAVE_SDL2)
     if(MINGW)
+        target_link_libraries(melt PRIVATE ${MLT_PTHREAD_LIBS})
         target_link_libraries(melt PRIVATE mingw32)
     endif()
 endif()

src/modules/avformat/CMakeLists.txt

@@ -28,6 +28,9 @@ target_compile_definitions(mltavformat PRIVATE FILTERS)
 
 if(WIN32)
   target_compile_definitions(mltavformat PRIVATE AVDATADIR="share/ffmpeg/")
+  if(MINGW)
+    target_link_libraries(mltavformat PRIVATE ${MLT_PTHREAD_LIBS})
+  endif()
 endif()
 
 if(TARGET PkgConfig::libavcodec)

src/modules/sdl2/CMakeLists.txt

@@ -14,6 +14,10 @@ target_compile_options(mltsdl2 PRIVATE ${MLT_COMPILE_OPTIONS})
 
 target_link_libraries(mltsdl2 PRIVATE mlt m Threads::Threads PkgConfig::sdl2)
 
+if(MINGW)
+  target_link_libraries(mltsdl2 PRIVATE ${MLT_PTHREAD_LIBS})
+endif()
+
 set_target_properties(mltsdl2 PROPERTIES LIBRARY_OUTPUT_DIRECTORY "${MLT_MODULE_OUTPUT_DIRECTORY}")
 
 install(TARGETS mltsdl2 LIBRARY DESTINATION ${MLT_INSTALL_MODULE_DIR})

src/win32/win32.c

@@ -46,16 +46,17 @@ int usleep(unsigned int useconds)
 	return 0;
 }
 
-
-int nanosleep( const struct timespec * rqtp, struct timespec * rmtp )
+#ifndef WIN_PTHREADS_TIME_H
+int nanosleep(const struct timespec * rqtp, struct timespec * rmtp)
 {
 	if (rqtp->tv_nsec > 999999999) {
 		/* The time interval specified 1,000,000 or more microseconds. */
 		errno = EINVAL;
 		return -1;
 	}
-	return usleep( rqtp->tv_sec * 1000000 + rqtp->tv_nsec / 1000 );
-} 
+    return usleep(rqtp->tv_sec * 1000000 + rqtp->tv_nsec / 1000);
+}
+#endif
 
 int setenv(const char *name, const char *value, int overwrite)
 {