Merge branch 'cmake-thread' of https://github.com/MaartenBent/wxWidgets

CMake: Link thread library only when necessary.

This also fixes finding threads under Android.

See #24356.

build/cmake/config.cmake

@@ -178,12 +178,8 @@ function(wx_write_config)
 
     set(CC ${CMAKE_C_COMPILER})
     set(CXX ${CMAKE_CXX_COMPILER})
-    set(WXCONFIG_CFLAGS)
-    set(WXCONFIG_LDFLAGS)
-    if(CMAKE_USE_PTHREADS_INIT)
-        set(WXCONFIG_CFLAGS "-pthread")
-        set(WXCONFIG_LDFLAGS "-pthread")
-    endif()
+    set(WXCONFIG_CFLAGS ${CMAKE_THREAD_LIBS_INIT})
+    set(WXCONFIG_LDFLAGS ${CMAKE_THREAD_LIBS_INIT})
     set(WXCONFIG_CPPFLAGS)
     if(wxBUILD_SHARED)
         wx_string_append(WXCONFIG_CPPFLAGS " -DWXUSINGDLL")

build/cmake/functions.cmake

@@ -177,12 +177,9 @@ function(wx_set_common_target_properties target_name)
         target_compile_definitions(${target_name} PUBLIC "-D_FILE_OFFSET_BITS=64")
     endif()
 
-    if(CMAKE_USE_PTHREADS_INIT)
-        target_compile_options(${target_name} PRIVATE "-pthread")
-        # clang++.exe: warning: argument unused during compilation: '-pthread' [-Wunused-command-line-argument]
-        if(NOT (WIN32 AND "${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang"))
-            set_target_properties(${target_name} PROPERTIES LINK_FLAGS "-pthread")
-        endif()
+    if(CMAKE_THREAD_LIBS_INIT)
+        target_compile_options(${target_name} PRIVATE ${CMAKE_THREAD_LIBS_INIT})
+        target_link_libraries(${target_name} PUBLIC ${CMAKE_THREAD_LIBS_INIT})
     endif()
     wx_set_source_groups()
 endfunction()

build/cmake/init.cmake

@@ -330,8 +330,15 @@ if(wxUSE_INTL AND NOT wxUSE_FILE)
 endif()
 
 if(wxUSE_THREADS)
+    if(ANDROID)
+        # Android has pthreads but FindThreads fails due to missing pthread_cancel
+        set(CMAKE_USE_PTHREADS_INIT 1)
+        set(CMAKE_THREAD_LIBS_INIT "")
+        set(Threads_FOUND TRUE)
+    else()
         find_package(Threads REQUIRED)
     endif()
+endif()
 
 if(wxUSE_LIBLZMA)
     find_package(LibLZMA)

build/cmake/setup.cmake

@@ -403,7 +403,7 @@ endif(UNIX)
 
 if(CMAKE_USE_PTHREADS_INIT)
     cmake_push_check_state(RESET)
-    set(CMAKE_REQUIRED_LIBRARIES pthread)
+    set(CMAKE_REQUIRED_LIBRARIES ${CMAKE_THREAD_LIBS_INIT})
     wx_check_cxx_source_compiles("
         void *p;
         pthread_cleanup_push(ThreadCleanupFunc, p);