diff --git a/CMakeLists.txt b/CMakeLists.txt
index ec8d50fd5..524481d67 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -822,7 +822,7 @@ if(SDL_ASSEMBLY)
         set(HAVE_ARMSIMD TRUE)
         set(SDL_ARM_SIMD_BLITTERS 1)
         file(GLOB ARMSIMD_SOURCES ${SDL2_SOURCE_DIR}/src/video/arm/pixman-arm-simd*.S)
-        set(SOURCE_FILES ${SOURCE_FILES} ${ARMSIMD_SOURCES})
+        list(APPEND SOURCE_FILES ${ARMSIMD_SOURCES})
         set(WARN_ABOUT_ARM_SIMD_ASM_MIT TRUE)
       endif()
     endif()
@@ -850,7 +850,7 @@ if(SDL_ASSEMBLY)
         set(HAVE_ARMNEON TRUE)
         set(SDL_ARM_NEON_BLITTERS 1)
         file(GLOB ARMNEON_SOURCES ${SDL2_SOURCE_DIR}/src/video/arm/pixman-arm-neon*.S)
-        set(SOURCE_FILES ${SOURCE_FILES} ${ARMNEON_SOURCES})
+        list(APPEND SOURCE_FILES ${ARMNEON_SOURCES})
         set(WARN_ABOUT_ARM_NEON_ASM_MIT TRUE)
       endif()
     endif()
@@ -1013,14 +1013,14 @@ if(SDL_AUDIO)
   if(SDL_DUMMYAUDIO)
     set(SDL_AUDIO_DRIVER_DUMMY 1)
     file(GLOB DUMMYAUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/dummy/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${DUMMYAUDIO_SOURCES})
+    list(APPEND SOURCE_FILES ${DUMMYAUDIO_SOURCES})
     set(HAVE_DUMMYAUDIO TRUE)
     set(HAVE_SDL_AUDIO TRUE)
   endif()
   if(SDL_DISKAUDIO)
     set(SDL_AUDIO_DRIVER_DISK 1)
     file(GLOB DISKAUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/disk/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${DISKAUDIO_SOURCES})
+    list(APPEND SOURCE_FILES ${DISKAUDIO_SOURCES})
     set(HAVE_DISKAUDIO TRUE)
     set(HAVE_SDL_AUDIO TRUE)
   endif()
@@ -1033,7 +1033,7 @@ if(UNIX OR APPLE)
   if(SDL_LOADSO AND HAVE_DLOPEN)
     set(SDL_LOADSO_DLOPEN 1)
     file(GLOB DLOPEN_SOURCES ${SDL2_SOURCE_DIR}/src/loadso/dlopen/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${DLOPEN_SOURCES})
+    list(APPEND SOURCE_FILES ${DLOPEN_SOURCES})
     set(HAVE_SDL_LOADSO TRUE)
   endif()
 endif()
@@ -1047,7 +1047,7 @@ if(SDL_JOYSTICK)
     set(HAVE_VIRTUAL_JOYSTICK TRUE)
     set(SDL_JOYSTICK_VIRTUAL 1)
     file(GLOB JOYSTICK_VIRTUAL_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/virtual/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${JOYSTICK_VIRTUAL_SOURCES})
+    list(APPEND SOURCE_FILES ${JOYSTICK_VIRTUAL_SOURCES})
   endif()
 endif()
 
@@ -1055,14 +1055,14 @@ if(SDL_VIDEO)
   if(SDL_DUMMYVIDEO)
     set(SDL_VIDEO_DRIVER_DUMMY 1)
     file(GLOB VIDEO_DUMMY_SOURCES ${SDL2_SOURCE_DIR}/src/video/dummy/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${VIDEO_DUMMY_SOURCES})
+    list(APPEND SOURCE_FILES ${VIDEO_DUMMY_SOURCES})
     set(HAVE_DUMMYVIDEO TRUE)
     set(HAVE_SDL_VIDEO TRUE)
   endif()
   if(SDL_OFFSCREEN)
     set(SDL_VIDEO_DRIVER_OFFSCREEN 1)
     file(GLOB VIDEO_OFFSCREEN_SOURCES ${SDL2_SOURCE_DIR}/src/video/offscreen/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${VIDEO_OFFSCREEN_SOURCES})
+    list(APPEND SOURCE_FILES ${VIDEO_OFFSCREEN_SOURCES})
     set(HAVE_OFFSCREEN TRUE)
     set(HAVE_SDL_VIDEO TRUE)
   endif()
@@ -1071,11 +1071,11 @@ endif()
 # Platform-specific options and settings
 if(ANDROID)
   file(GLOB ANDROID_CORE_SOURCES ${SDL2_SOURCE_DIR}/src/core/android/*.c)
-  set(SOURCE_FILES ${SOURCE_FILES} ${ANDROID_CORE_SOURCES} ${ANDROID_NDK}/sources/android/cpufeatures/cpu-features.c)
+  list(APPEND SOURCE_FILES ${ANDROID_CORE_SOURCES} ${ANDROID_NDK}/sources/android/cpufeatures/cpu-features.c)
 
   if(SDL_MISC)
     file(GLOB ANDROID_MISC_SOURCES ${SDL2_SOURCE_DIR}/src/misc/android/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${ANDROID_MISC_SOURCES})
+    list(APPEND SOURCE_FILES ${ANDROID_MISC_SOURCES})
     set(HAVE_SDL_MISC TRUE)
   endif()
 
@@ -1094,31 +1094,31 @@ if(ANDROID)
   if(SDL_AUDIO)
     set(SDL_AUDIO_DRIVER_ANDROID 1)
     file(GLOB ANDROID_AUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/android/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${ANDROID_AUDIO_SOURCES})
+    list(APPEND SOURCE_FILES ${ANDROID_AUDIO_SOURCES})
 
     set(SDL_AUDIO_DRIVER_OPENSLES 1)
     file(GLOB OPENSLES_AUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/openslES/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${OPENSLES_AUDIO_SOURCES})
+    list(APPEND SOURCE_FILES ${OPENSLES_AUDIO_SOURCES})
 
     find_library(ANDROID_OPENSLES_LIBRARY OpenSLES)
     list(APPEND EXTRA_LIBS ${ANDROID_DL_LIBRARY} ${ANDROID_OPENSLES_LIBRARY})
 
     set(SDL_AUDIO_DRIVER_AAUDIO 1)
     file(GLOB AAUDIO_AUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/aaudio/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${AAUDIO_AUDIO_SOURCES})
+    list(APPEND SOURCE_FILES ${AAUDIO_AUDIO_SOURCES})
 
     set(HAVE_SDL_AUDIO TRUE)
   endif()
   if(SDL_FILESYSTEM)
     set(SDL_FILESYSTEM_ANDROID 1)
     file(GLOB ANDROID_FILESYSTEM_SOURCES ${SDL2_SOURCE_DIR}/src/filesystem/android/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${ANDROID_FILESYSTEM_SOURCES})
+    list(APPEND SOURCE_FILES ${ANDROID_FILESYSTEM_SOURCES})
     set(HAVE_SDL_FILESYSTEM TRUE)
   endif()
   if(SDL_HAPTIC)
     set(SDL_HAPTIC_ANDROID 1)
     file(GLOB ANDROID_HAPTIC_SOURCES ${SDL2_SOURCE_DIR}/src/haptic/android/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${ANDROID_HAPTIC_SOURCES})
+    list(APPEND SOURCE_FILES ${ANDROID_HAPTIC_SOURCES})
     set(HAVE_SDL_HAPTIC TRUE)
   endif()
   if(SDL_HIDAPI)
@@ -1127,42 +1127,42 @@ if(ANDROID)
   if(SDL_JOYSTICK)
     set(SDL_JOYSTICK_ANDROID 1)
     file(GLOB ANDROID_JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/android/*.c ${SDL2_SOURCE_DIR}/src/joystick/steam/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${ANDROID_JOYSTICK_SOURCES})
+    list(APPEND SOURCE_FILES ${ANDROID_JOYSTICK_SOURCES})
     set(HAVE_SDL_JOYSTICK TRUE)
   endif()
   if(SDL_LOADSO)
     set(SDL_LOADSO_DLOPEN 1)
     file(GLOB LOADSO_SOURCES ${SDL2_SOURCE_DIR}/src/loadso/dlopen/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${LOADSO_SOURCES})
+    list(APPEND SOURCE_FILES ${LOADSO_SOURCES})
     set(HAVE_SDL_LOADSO TRUE)
   endif()
   if(SDL_POWER)
     set(SDL_POWER_ANDROID 1)
     file(GLOB ANDROID_POWER_SOURCES ${SDL2_SOURCE_DIR}/src/power/android/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${ANDROID_POWER_SOURCES})
+    list(APPEND SOURCE_FILES ${ANDROID_POWER_SOURCES})
     set(HAVE_SDL_POWER TRUE)
   endif()
   if(SDL_LOCALE)
     file(GLOB ANDROID_LOCALE_SOURCES ${SDL2_SOURCE_DIR}/src/locale/android/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${ANDROID_LOCALE_SOURCES})
+    list(APPEND SOURCE_FILES ${ANDROID_LOCALE_SOURCES})
     set(HAVE_SDL_LOCALE TRUE)
   endif()
   if(SDL_TIMERS)
     set(SDL_TIMER_UNIX 1)
     file(GLOB TIMER_SOURCES ${SDL2_SOURCE_DIR}/src/timer/unix/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${TIMER_SOURCES})
+    list(APPEND SOURCE_FILES ${TIMER_SOURCES})
     set(HAVE_SDL_TIMERS TRUE)
   endif()
   if(SDL_SENSOR)
     set(SDL_SENSOR_ANDROID 1)
     set(HAVE_SDL_SENSORS TRUE)
     file(GLOB ANDROID_SENSOR_SOURCES ${SDL2_SOURCE_DIR}/src/sensor/android/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${ANDROID_SENSOR_SOURCES})
+    list(APPEND SOURCE_FILES ${ANDROID_SENSOR_SOURCES})
   endif()
   if(SDL_VIDEO)
     set(SDL_VIDEO_DRIVER_ANDROID 1)
     file(GLOB ANDROID_VIDEO_SOURCES ${SDL2_SOURCE_DIR}/src/video/android/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${ANDROID_VIDEO_SOURCES})
+    list(APPEND SOURCE_FILES ${ANDROID_VIDEO_SOURCES})
     set(HAVE_SDL_VIDEO TRUE)
 
     # Core stuff
@@ -1211,42 +1211,42 @@ elseif(EMSCRIPTEN)
 
   if(SDL_MISC)
     file(GLOB EMSRIPTEN_MISC_SOURCES ${SDL2_SOURCE_DIR}/src/misc/emscripten/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${EMSRIPTEN_MISC_SOURCES})
+    list(APPEND SOURCE_FILES ${EMSRIPTEN_MISC_SOURCES})
     set(HAVE_SDL_MISC TRUE)
   endif()
   if(SDL_AUDIO)
     set(SDL_AUDIO_DRIVER_EMSCRIPTEN 1)
     file(GLOB EM_AUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/emscripten/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${EM_AUDIO_SOURCES})
+    list(APPEND SOURCE_FILES ${EM_AUDIO_SOURCES})
     set(HAVE_SDL_AUDIO TRUE)
   endif()
   if(SDL_FILESYSTEM)
     set(SDL_FILESYSTEM_EMSCRIPTEN 1)
     file(GLOB EM_FILESYSTEM_SOURCES ${SDL2_SOURCE_DIR}/src/filesystem/emscripten/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${EM_FILESYSTEM_SOURCES})
+    list(APPEND SOURCE_FILES ${EM_FILESYSTEM_SOURCES})
     set(HAVE_SDL_FILESYSTEM TRUE)
   endif()
   if(SDL_JOYSTICK)
     set(SDL_JOYSTICK_EMSCRIPTEN 1)
     file(GLOB EM_JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/emscripten/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${EM_JOYSTICK_SOURCES})
+    list(APPEND SOURCE_FILES ${EM_JOYSTICK_SOURCES})
     set(HAVE_SDL_JOYSTICK TRUE)
   endif()
   if(SDL_POWER)
     set(SDL_POWER_EMSCRIPTEN 1)
     file(GLOB EM_POWER_SOURCES ${SDL2_SOURCE_DIR}/src/power/emscripten/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${EM_POWER_SOURCES})
+    list(APPEND SOURCE_FILES ${EM_POWER_SOURCES})
     set(HAVE_SDL_POWER TRUE)
   endif()
   if(SDL_LOCALE)
     file(GLOB LOCALE_SOURCES ${SDL2_SOURCE_DIR}/src/locale/emscripten/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${LOCALE_SOURCES})
+    list(APPEND SOURCE_FILES ${LOCALE_SOURCES})
     set(HAVE_SDL_LOCALE TRUE)
   endif()
   if(SDL_TIMERS)
     set(SDL_TIMER_UNIX 1)
     file(GLOB TIMER_SOURCES ${SDL2_SOURCE_DIR}/src/timer/unix/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${TIMER_SOURCES})
+    list(APPEND SOURCE_FILES ${TIMER_SOURCES})
     set(HAVE_SDL_TIMERS TRUE)
 
     if(SDL_CLOCK_GETTIME)
@@ -1256,7 +1256,7 @@ elseif(EMSCRIPTEN)
   if(SDL_VIDEO)
     set(SDL_VIDEO_DRIVER_EMSCRIPTEN 1)
     file(GLOB EM_VIDEO_SOURCES ${SDL2_SOURCE_DIR}/src/video/emscripten/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${EM_VIDEO_SOURCES})
+    list(APPEND SOURCE_FILES ${EM_VIDEO_SOURCES})
     set(HAVE_SDL_VIDEO TRUE)
 
     #enable gles
@@ -1275,17 +1275,17 @@ elseif(UNIX AND NOT APPLE AND NOT ANDROID AND NOT RISCOS AND NOT HAIKU)
     if(SYSV5 OR SOLARIS OR HPUX)
         set(SDL_AUDIO_DRIVER_SUNAUDIO 1)
         file(GLOB SUN_AUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/sun/*.c)
-        set(SOURCE_FILES ${SOURCE_FILES} ${SUN_AUDIO_SOURCES})
+        list(APPEND SOURCE_FILES ${SUN_AUDIO_SOURCES})
         set(HAVE_SDL_AUDIO TRUE)
     elseif(NETBSD)
         set(SDL_AUDIO_DRIVER_NETBSD 1)
         file(GLOB NETBSD_AUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/netbsd/*.c)
-        set(SOURCE_FILES ${SOURCE_FILES} ${NETBSD_AUDIO_SOURCES})
+        list(APPEND SOURCE_FILES ${NETBSD_AUDIO_SOURCES})
         set(HAVE_SDL_AUDIO TRUE)
     elseif(AIX)
         set(SDL_AUDIO_DRIVER_PAUDIO 1)
         file(GLOB AIX_AUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/paudio/*.c)
-        set(SOURCE_FILES ${SOURCE_FILES} ${AIX_AUDIO_SOURCES})
+        list(APPEND SOURCE_FILES ${AIX_AUDIO_SOURCES})
         set(HAVE_SDL_AUDIO TRUE)
     endif()
     CheckOSS()
@@ -1323,7 +1323,7 @@ elseif(UNIX AND NOT APPLE AND NOT ANDROID AND NOT RISCOS AND NOT HAIKU)
 
   if(UNIX)
     file(GLOB CORE_UNIX_SOURCES ${SDL2_SOURCE_DIR}/src/core/unix/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${CORE_UNIX_SOURCES})
+    list(APPEND SOURCE_FILES ${CORE_UNIX_SOURCES})
 
     check_c_source_compiles("
         #include <linux/input.h>
@@ -1360,7 +1360,7 @@ elseif(UNIX AND NOT APPLE AND NOT ANDROID AND NOT RISCOS AND NOT HAIKU)
     if(SDL_HAPTIC AND HAVE_INPUT_EVENTS)
       set(SDL_HAPTIC_LINUX 1)
       file(GLOB HAPTIC_SOURCES ${SDL2_SOURCE_DIR}/src/haptic/linux/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${HAPTIC_SOURCES})
+      list(APPEND SOURCE_FILES ${HAPTIC_SOURCES})
       set(HAVE_SDL_HAPTIC TRUE)
     endif()
 
@@ -1420,37 +1420,37 @@ elseif(UNIX AND NOT APPLE AND NOT ANDROID AND NOT RISCOS AND NOT HAIKU)
     endif()
 
     if(HAVE_DBUS_DBUS_H)
-      set(SOURCE_FILES ${SOURCE_FILES} "${SDL2_SOURCE_DIR}/src/core/linux/SDL_dbus.c")
+      list(APPEND SOURCE_FILES "${SDL2_SOURCE_DIR}/src/core/linux/SDL_dbus.c")
     endif()
 
     if(SDL_USE_IME)
-      set(SOURCE_FILES ${SOURCE_FILES} "${SDL2_SOURCE_DIR}/src/core/linux/SDL_ime.c")
+      list(APPEND SOURCE_FILES "${SDL2_SOURCE_DIR}/src/core/linux/SDL_ime.c")
     endif()
 
     if(HAVE_IBUS_IBUS_H)
-      set(SOURCE_FILES ${SOURCE_FILES} "${SDL2_SOURCE_DIR}/src/core/linux/SDL_ibus.c")
+      list(APPEND SOURCE_FILES "${SDL2_SOURCE_DIR}/src/core/linux/SDL_ibus.c")
     endif()
 
     if(HAVE_FCITX)
-      set(SOURCE_FILES ${SOURCE_FILES} "${SDL2_SOURCE_DIR}/src/core/linux/SDL_fcitx.c")
+      list(APPEND SOURCE_FILES "${SDL2_SOURCE_DIR}/src/core/linux/SDL_fcitx.c")
     endif()
 
     if(HAVE_LIBUDEV_H)
-      set(SOURCE_FILES ${SOURCE_FILES} "${SDL2_SOURCE_DIR}/src/core/linux/SDL_udev.c")
+      list(APPEND SOURCE_FILES "${SDL2_SOURCE_DIR}/src/core/linux/SDL_udev.c")
     endif()
 
     if(HAVE_INPUT_EVENTS)
-      set(SOURCE_FILES ${SOURCE_FILES} "${SDL2_SOURCE_DIR}/src/core/linux/SDL_evdev.c")
-      set(SOURCE_FILES ${SOURCE_FILES} "${SDL2_SOURCE_DIR}/src/core/linux/SDL_evdev_kbd.c")
+      list(APPEND SOURCE_FILES "${SDL2_SOURCE_DIR}/src/core/linux/SDL_evdev.c")
+      list(APPEND SOURCE_FILES "${SDL2_SOURCE_DIR}/src/core/linux/SDL_evdev_kbd.c")
     endif()
 
     if(HAVE_INPUT_KBIO)
-      set(SOURCE_FILES ${SOURCE_FILES} "${SDL2_SOURCE_DIR}/src/core/freebsd/SDL_evdev_kbd_freebsd.c")
+      list(APPEND SOURCE_FILES "${SDL2_SOURCE_DIR}/src/core/freebsd/SDL_evdev_kbd_freebsd.c")
     endif()
 
     # Always compiled for Linux, unconditionally:
-    set(SOURCE_FILES ${SOURCE_FILES} "${SDL2_SOURCE_DIR}/src/core/linux/SDL_evdev_capabilities.c")
-    set(SOURCE_FILES ${SOURCE_FILES} "${SDL2_SOURCE_DIR}/src/core/linux/SDL_threadprio.c")
+    list(APPEND SOURCE_FILES "${SDL2_SOURCE_DIR}/src/core/linux/SDL_evdev_capabilities.c")
+    list(APPEND SOURCE_FILES "${SDL2_SOURCE_DIR}/src/core/linux/SDL_threadprio.c")
 
     # src/core/unix/*.c is included in a generic if(UNIX) section, elsewhere.
   endif()
@@ -1466,7 +1466,7 @@ elseif(UNIX AND NOT APPLE AND NOT ANDROID AND NOT RISCOS AND NOT HAIKU)
     if(LINUX AND NOT ANDROID)
       set(SDL_JOYSTICK_LINUX 1)
       file(GLOB JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/linux/*.c ${SDL2_SOURCE_DIR}/src/joystick/steam/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${JOYSTICK_SOURCES})
+      list(APPEND SOURCE_FILES ${JOYSTICK_SOURCES})
       set(HAVE_SDL_JOYSTICK TRUE)
     endif()
   endif()
@@ -1493,7 +1493,7 @@ elseif(UNIX AND NOT APPLE AND NOT ANDROID AND NOT RISCOS AND NOT HAIKU)
 
   if(SDL_MISC)
     file(GLOB MISC_SOURCES ${SDL2_SOURCE_DIR}/src/misc/unix/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${MISC_SOURCES})
+    list(APPEND SOURCE_FILES ${MISC_SOURCES})
     set(HAVE_SDL_MISC TRUE)
   endif()
 
@@ -1501,28 +1501,28 @@ elseif(UNIX AND NOT APPLE AND NOT ANDROID AND NOT RISCOS AND NOT HAIKU)
     if(LINUX)
       set(SDL_POWER_LINUX 1)
       file(GLOB POWER_SOURCES ${SDL2_SOURCE_DIR}/src/power/linux/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${POWER_SOURCES})
+      list(APPEND SOURCE_FILES ${POWER_SOURCES})
       set(HAVE_SDL_POWER TRUE)
     endif()
   endif()
 
   if(SDL_LOCALE)
     file(GLOB LOCALE_SOURCES ${SDL2_SOURCE_DIR}/src/locale/unix/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${LOCALE_SOURCES})
+    list(APPEND SOURCE_FILES ${LOCALE_SOURCES})
     set(HAVE_SDL_LOCALE TRUE)
   endif()
 
   if(SDL_FILESYSTEM)
     set(SDL_FILESYSTEM_UNIX 1)
     file(GLOB FILESYSTEM_SOURCES ${SDL2_SOURCE_DIR}/src/filesystem/unix/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${FILESYSTEM_SOURCES})
+    list(APPEND SOURCE_FILES ${FILESYSTEM_SOURCES})
     set(HAVE_SDL_FILESYSTEM TRUE)
   endif()
 
   if(SDL_TIMERS)
     set(SDL_TIMER_UNIX 1)
     file(GLOB TIMER_SOURCES ${SDL2_SOURCE_DIR}/src/timer/unix/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${TIMER_SOURCES})
+    list(APPEND SOURCE_FILES ${TIMER_SOURCES})
     set(HAVE_SDL_TIMERS TRUE)
   endif()
 
@@ -1552,7 +1552,7 @@ elseif(WINDOWS)
     int main(int argc, char **argv) { return 0; }" HAVE_WIN32_CC)
 
   file(GLOB CORE_SOURCES ${SDL2_SOURCE_DIR}/src/core/windows/*.c)
-  set(SOURCE_FILES ${SOURCE_FILES} ${CORE_SOURCES})
+  list(APPEND SOURCE_FILES ${CORE_SOURCES})
 
   if(WINDOWS_STORE)
     file(GLOB WINRT_SOURCE_FILES ${SDL2_SOURCE_DIR}/src/core/winrt/*.c ${SDL2_SOURCE_DIR}/src/core/winrt/*.cpp)
@@ -1573,7 +1573,7 @@ elseif(WINDOWS)
     else()
       file(GLOB MISC_SOURCES ${SDL2_SOURCE_DIR}/src/misc/windows/*.c)
     endif()
-    set(SOURCE_FILES ${SOURCE_FILES} ${MISC_SOURCES})
+    list(APPEND SOURCE_FILES ${MISC_SOURCES})
     set(HAVE_SDL_MISC TRUE)
   endif()
 
@@ -1651,14 +1651,14 @@ elseif(WINDOWS)
     if(NOT WINDOWS_STORE)
       set(SDL_AUDIO_DRIVER_WINMM 1)
       file(GLOB WINMM_AUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/winmm/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${WINMM_AUDIO_SOURCES})
+      list(APPEND SOURCE_FILES ${WINMM_AUDIO_SOURCES})
       set(HAVE_SDL_AUDIO TRUE)
     endif()
 
     if(HAVE_DSOUND_H AND NOT WINDOWS_STORE)
       set(SDL_AUDIO_DRIVER_DSOUND 1)
       file(GLOB DSOUND_AUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/directsound/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${DSOUND_AUDIO_SOURCES})
+      list(APPEND SOURCE_FILES ${DSOUND_AUDIO_SOURCES})
       set(HAVE_SDL_AUDIO TRUE)
     endif()
 
@@ -1669,7 +1669,7 @@ elseif(WINDOWS)
       if(WINDOWS_STORE)
         list(APPEND WASAPI_AUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/wasapi/SDL_wasapi_winrt.cpp)
       endif()
-      set(SOURCE_FILES ${SOURCE_FILES} ${WASAPI_AUDIO_SOURCES})
+      list(APPEND SOURCE_FILES ${WASAPI_AUDIO_SOURCES})
       set(HAVE_SDL_AUDIO TRUE)
     endif()
   endif()
@@ -1690,7 +1690,7 @@ elseif(WINDOWS)
       set(SDL_VIDEO_DRIVER_WINDOWS 1)
       file(GLOB WIN_VIDEO_SOURCES ${SDL2_SOURCE_DIR}/src/video/windows/*.c)
     endif()
-    set(SOURCE_FILES ${SOURCE_FILES} ${WIN_VIDEO_SOURCES})
+    list(APPEND SOURCE_FILES ${WIN_VIDEO_SOURCES})
 
     if(SDL_RENDER_D3D AND HAVE_D3D_H AND NOT WINDOWS_STORE)
       set(SDL_VIDEO_RENDER_D3D 1)
@@ -1724,16 +1724,16 @@ elseif(WINDOWS)
     set(SDL_SENSOR_WINDOWS 1)
     set(HAVE_SDL_SENSORS TRUE)
     file(GLOB WINDOWS_SENSOR_SOURCES ${SDL2_SOURCE_DIR}/src/sensor/windows/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${WINDOWS_SENSOR_SOURCES})
+    list(APPEND SOURCE_FILES ${WINDOWS_SENSOR_SOURCES})
   endif()
 
   if(SDL_POWER)
     if(WINDOWS_STORE)
       set(SDL_POWER_WINRT 1)
-      set(SOURCE_FILES ${SOURCE_FILES} ${SDL2_SOURCE_DIR}/src/power/winrt/SDL_syspower.cpp)
+      list(APPEND SOURCE_FILES ${SDL2_SOURCE_DIR}/src/power/winrt/SDL_syspower.cpp)
     else()
       set(SDL_POWER_WINDOWS 1)
-      set(SOURCE_FILES ${SOURCE_FILES} ${SDL2_SOURCE_DIR}/src/power/windows/SDL_syspower.c)
+      list(APPEND SOURCE_FILES ${SDL2_SOURCE_DIR}/src/power/windows/SDL_syspower.c)
       set(HAVE_SDL_POWER TRUE)
     endif()
   endif()
@@ -1744,7 +1744,7 @@ elseif(WINDOWS)
     else()
       file(GLOB LOCALE_SOURCES ${SDL2_SOURCE_DIR}/src/locale/windows/*.c)
     endif()
-    set(SOURCE_FILES ${SOURCE_FILES} ${LOCALE_SOURCES})
+    list(APPEND SOURCE_FILES ${LOCALE_SOURCES})
     set(HAVE_SDL_LOCALE TRUE)
   endif()
 
@@ -1755,7 +1755,7 @@ elseif(WINDOWS)
     else()
       file(GLOB FILESYSTEM_SOURCES ${SDL2_SOURCE_DIR}/src/filesystem/windows/*.c)
     endif()
-    set(SOURCE_FILES ${SOURCE_FILES} ${FILESYSTEM_SOURCES})
+    list(APPEND SOURCE_FILES ${FILESYSTEM_SOURCES})
     set(HAVE_SDL_FILESYSTEM TRUE)
   endif()
 
@@ -1776,19 +1776,19 @@ elseif(WINDOWS)
   if(SDL_TIMERS)
     set(SDL_TIMER_WINDOWS 1)
     file(GLOB TIMER_SOURCES ${SDL2_SOURCE_DIR}/src/timer/windows/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${TIMER_SOURCES})
+    list(APPEND SOURCE_FILES ${TIMER_SOURCES})
     set(HAVE_SDL_TIMERS TRUE)
   endif()
 
   if(SDL_LOADSO)
     set(SDL_LOADSO_WINDOWS 1)
     file(GLOB LOADSO_SOURCES ${SDL2_SOURCE_DIR}/src/loadso/windows/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${LOADSO_SOURCES})
+    list(APPEND SOURCE_FILES ${LOADSO_SOURCES})
     set(HAVE_SDL_LOADSO TRUE)
   endif()
 
   file(GLOB CORE_SOURCES ${SDL2_SOURCE_DIR}/src/core/windows/*.c)
-  set(SOURCE_FILES ${SOURCE_FILES} ${CORE_SOURCES})
+  list(APPEND SOURCE_FILES ${CORE_SOURCES})
 
   if(SDL_VIDEO)
     if(SDL_OPENGL AND NOT WINDOWS_STORE)
@@ -1817,7 +1817,7 @@ elseif(WINDOWS)
 
   if(SDL_JOYSTICK)
     file(GLOB JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/windows/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${JOYSTICK_SOURCES})
+    list(APPEND SOURCE_FILES ${JOYSTICK_SOURCES})
 
     if(NOT WINDOWS_STORE)
       set(SDL_JOYSTICK_RAWINPUT 1)
@@ -1850,7 +1850,7 @@ elseif(WINDOWS)
         file(GLOB HAPTIC_SOURCES ${SDL2_SOURCE_DIR}/src/haptic/dummy/*.c)
         set(SDL_HAPTIC_DUMMY 1)
       endif()
-      set(SOURCE_FILES ${SOURCE_FILES} ${HAPTIC_SOURCES})
+      list(APPEND SOURCE_FILES ${HAPTIC_SOURCES})
       set(HAVE_SDL_HAPTIC TRUE)
     endif()
   endif()
@@ -1896,14 +1896,14 @@ elseif(APPLE)
     else()
       file(GLOB MISC_SOURCES ${SDL2_SOURCE_DIR}/src/misc/macosx/*.m)
     endif()
-    set(SOURCE_FILES ${SOURCE_FILES} ${MISC_SOURCES})
+    list(APPEND SOURCE_FILES ${MISC_SOURCES})
     set(HAVE_SDL_MISC TRUE)
   endif()
 
   if(SDL_AUDIO)
     set(SDL_AUDIO_DRIVER_COREAUDIO 1)
     file(GLOB AUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/coreaudio/*.m)
-    set(SOURCE_FILES ${SOURCE_FILES} ${AUDIO_SOURCES})
+    list(APPEND SOURCE_FILES ${AUDIO_SOURCES})
     set(HAVE_SDL_AUDIO TRUE)
     set(SDL_FRAMEWORK_COREAUDIO 1)
     set(SDL_FRAMEWORK_AUDIOTOOLBOX 1)
@@ -1955,7 +1955,7 @@ elseif(APPLE)
       set(SDL_FRAMEWORK_IOKIT 1)
       set(SDL_FRAMEWORK_FF 1)
     endif()
-    set(SOURCE_FILES ${SOURCE_FILES} ${JOYSTICK_SOURCES} ${MFI_JOYSTICK_SOURCES})
+    list(APPEND SOURCE_FILES ${JOYSTICK_SOURCES} ${MFI_JOYSTICK_SOURCES})
     set(HAVE_SDL_JOYSTICK TRUE)
   endif()
 
@@ -1969,7 +1969,7 @@ elseif(APPLE)
       set(SDL_FRAMEWORK_IOKIT 1)
       set(SDL_FRAMEWORK_FF 1)
     endif()
-    set(SOURCE_FILES ${SOURCE_FILES} ${HAPTIC_SOURCES})
+    list(APPEND SOURCE_FILES ${HAPTIC_SOURCES})
     set(HAVE_SDL_HAPTIC TRUE)
   endif()
 
@@ -1982,27 +1982,27 @@ elseif(APPLE)
       set(SDL_POWER_MACOSX 1)
       set(SDL_FRAMEWORK_IOKIT 1)
     endif()
-    set(SOURCE_FILES ${SOURCE_FILES} ${POWER_SOURCES})
+    list(APPEND SOURCE_FILES ${POWER_SOURCES})
     set(HAVE_SDL_POWER TRUE)
   endif()
 
   if(SDL_LOCALE)
     file(GLOB LOCALE_SOURCES ${SDL2_SOURCE_DIR}/src/locale/macosx/*.m)
-    set(SOURCE_FILES ${SOURCE_FILES} ${LOCALE_SOURCES})
+    list(APPEND SOURCE_FILES ${LOCALE_SOURCES})
     set(HAVE_SDL_LOCALE TRUE)
   endif()
 
   if(SDL_TIMERS)
     set(SDL_TIMER_UNIX 1)
     file(GLOB TIMER_SOURCES ${SDL2_SOURCE_DIR}/src/timer/unix/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${TIMER_SOURCES})
+    list(APPEND SOURCE_FILES ${TIMER_SOURCES})
     set(HAVE_SDL_TIMERS TRUE)
   endif(SDL_TIMERS)
 
   if(SDL_FILESYSTEM)
     set(SDL_FILESYSTEM_COCOA 1)
     file(GLOB FILESYSTEM_SOURCES ${SDL2_SOURCE_DIR}/src/filesystem/cocoa/*.m)
-    set(SOURCE_FILES ${SOURCE_FILES} ${FILESYSTEM_SOURCES})
+    list(APPEND SOURCE_FILES ${FILESYSTEM_SOURCES})
     set(HAVE_SDL_FILESYSTEM TRUE)
   endif()
 
@@ -2011,7 +2011,7 @@ elseif(APPLE)
       set(SDL_SENSOR_COREMOTION 1)
       set(HAVE_SDL_SENSORS TRUE)
       file(GLOB SENSOR_SOURCES ${SDL2_SOURCE_DIR}/src/sensor/coremotion/*.m)
-      set(SOURCE_FILES ${SOURCE_FILES} ${SENSOR_SOURCES})
+      list(APPEND SOURCE_FILES ${SENSOR_SOURCES})
     endif()
   endif()
 
@@ -2025,7 +2025,7 @@ elseif(APPLE)
       set(SDL_IPHONE_KEYBOARD 1)
       set(SDL_IPHONE_LAUNCHSCREEN 1)
       file(GLOB UIKITVIDEO_SOURCES ${SDL2_SOURCE_DIR}/src/video/uikit/*.m)
-      set(SOURCE_FILES ${SOURCE_FILES} ${UIKITVIDEO_SOURCES})
+      list(APPEND SOURCE_FILES ${UIKITVIDEO_SOURCES})
       set(HAVE_SDL_VIDEO TRUE)
     else()
       CheckCOCOA()
@@ -2073,7 +2073,7 @@ elseif(APPLE)
         endif()
         if(SDL_RENDER_METAL)
           file(GLOB RENDER_METAL_SOURCES ${SDL2_SOURCE_DIR}/src/render/metal/*.m)
-          set(SOURCE_FILES ${SOURCE_FILES} ${RENDER_METAL_SOURCES})
+          list(APPEND SOURCE_FILES ${RENDER_METAL_SOURCES})
           set(SDL_VIDEO_RENDER_METAL 1)
           set(HAVE_RENDER_METAL TRUE)
         endif()
@@ -2173,27 +2173,27 @@ elseif(HAIKU)
   if(SDL_AUDIO)
     set(SDL_AUDIO_DRIVER_HAIKU 1)
     file(GLOB HAIKU_AUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/haiku/*.cc)
-    set(SOURCE_FILES ${SOURCE_FILES} ${HAIKU_AUDIO_SOURCES})
+    list(APPEND SOURCE_FILES ${HAIKU_AUDIO_SOURCES})
     set(HAVE_SDL_AUDIO TRUE)
   endif()
 
   if(SDL_JOYSTICK)
     set(SDL_JOYSTICK_HAIKU 1)
     file(GLOB HAIKU_JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/haiku/*.cc)
-    set(SOURCE_FILES ${SOURCE_FILES} ${HAIKU_JOYSTICK_SOURCES})
+    list(APPEND SOURCE_FILES ${HAIKU_JOYSTICK_SOURCES})
     set(HAVE_SDL_JOYSTICK TRUE)
   endif()
 
   if(SDL_MISC)
     file(GLOB MISC_SOURCES ${SDL2_SOURCE_DIR}/src/misc/haiku/*.cc)
-    set(SOURCE_FILES ${SOURCE_FILES} ${MISC_SOURCES})
+    list(APPEND SOURCE_FILES ${MISC_SOURCES})
     set(HAVE_SDL_MISC TRUE)
   endif()
 
   if(SDL_VIDEO)
     set(SDL_VIDEO_DRIVER_HAIKU 1)
     file(GLOB HAIKUVIDEO_SOURCES ${SDL2_SOURCE_DIR}/src/video/haiku/*.cc)
-    set(SOURCE_FILES ${SOURCE_FILES} ${HAIKUVIDEO_SOURCES})
+    list(APPEND SOURCE_FILES ${HAIKUVIDEO_SOURCES})
     set(HAVE_SDL_VIDEO TRUE)
 
     if(SDL_OPENGL)
@@ -2209,32 +2209,32 @@ elseif(HAIKU)
   if(SDL_FILESYSTEM)
     set(SDL_FILESYSTEM_HAIKU 1)
     file(GLOB FILESYSTEM_SOURCES ${SDL2_SOURCE_DIR}/src/filesystem/haiku/*.cc)
-    set(SOURCE_FILES ${SOURCE_FILES} ${FILESYSTEM_SOURCES})
+    list(APPEND SOURCE_FILES ${FILESYSTEM_SOURCES})
     set(HAVE_SDL_FILESYSTEM TRUE)
   endif()
 
   if(SDL_TIMERS)
     set(SDL_TIMER_HAIKU 1)
     file(GLOB TIMER_SOURCES ${SDL2_SOURCE_DIR}/src/timer/haiku/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${TIMER_SOURCES})
+    list(APPEND SOURCE_FILES ${TIMER_SOURCES})
     set(HAVE_SDL_TIMERS TRUE)
   endif()
 
   if(SDL_POWER)
     set(SDL_POWER_HAIKU 1)
     file(GLOB HAIKU_POWER_SOURCES ${SDL2_SOURCE_DIR}/src/power/haiku/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${HAIKU_POWER_SOURCES})
+    list(APPEND SOURCE_FILES ${HAIKU_POWER_SOURCES})
     set(HAVE_SDL_POWER TRUE)
   endif()
 
   if(SDL_LOCALE)
     file(GLOB LOCALE_SOURCES ${SDL2_SOURCE_DIR}/src/locale/haiku/*.cc)
-    set(SOURCE_FILES ${SOURCE_FILES} ${LOCALE_SOURCES})
+    list(APPEND SOURCE_FILES ${LOCALE_SOURCES})
     set(HAVE_SDL_LOCALE TRUE)
   endif()
 
   file(GLOB MAIN_SOURCES ${SDL2_SOURCE_DIR}/src/main/haiku/*.cc)
-  set(SOURCE_FILES ${SOURCE_FILES} ${MAIN_SOURCES})
+  list(APPEND SOURCE_FILES ${MAIN_SOURCES})
 
   CheckPTHREAD()
   list(APPEND EXTRA_LIBS root be media game device textencoding)
@@ -2242,28 +2242,28 @@ elseif(HAIKU)
 elseif(RISCOS)
   if(SDL_MISC)
     file(GLOB MISC_SOURCES ${SDL2_SOURCE_DIR}/src/misc/riscos/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${MISC_SOURCES})
+    list(APPEND SOURCE_FILES ${MISC_SOURCES})
     set(HAVE_SDL_MISC TRUE)
   endif()
 
   if(SDL_VIDEO)
     set(SDL_VIDEO_DRIVER_RISCOS 1)
     file(GLOB RISCOSVIDEO_SOURCES ${SDL2_SOURCE_DIR}/src/video/riscos/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${RISCOSVIDEO_SOURCES})
+    list(APPEND SOURCE_FILES ${RISCOSVIDEO_SOURCES})
     set(HAVE_SDL_VIDEO TRUE)
   endif()
 
   if(SDL_FILESYSTEM)
     set(SDL_FILESYSTEM_RISCOS 1)
     file(GLOB FILESYSTEM_SOURCES ${SDL2_SOURCE_DIR}/src/filesystem/riscos/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${FILESYSTEM_SOURCES})
+    list(APPEND SOURCE_FILES ${FILESYSTEM_SOURCES})
     set(HAVE_SDL_FILESYSTEM TRUE)
   endif()
 
   if(SDL_TIMERS)
     set(SDL_TIMER_UNIX 1)
     file(GLOB TIMER_SOURCES ${SDL2_SOURCE_DIR}/src/timer/unix/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${TIMER_SOURCES})
+    list(APPEND SOURCE_FILES ${TIMER_SOURCES})
     set(HAVE_SDL_TIMERS TRUE)
 
     if(SDL_CLOCK_GETTIME)
@@ -2286,32 +2286,32 @@ elseif(VITA)
 
   if(SDL_MISC)
     file(GLOB MISC_SOURCES ${SDL2_SOURCE_DIR}/src/misc/vita/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${MISC_SOURCES})
+    list(APPEND SOURCE_FILES ${MISC_SOURCES})
     set(HAVE_SDL_MISC TRUE)
   endif()
 
   if(SDL_AUDIO)
     set(SDL_AUDIO_DRIVER_VITA 1)
     file(GLOB VITA_AUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/vita/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${VITA_AUDIO_SOURCES})
+    list(APPEND SOURCE_FILES ${VITA_AUDIO_SOURCES})
     set(HAVE_SDL_AUDIO TRUE)
   endif()
   if(SDL_FILESYSTEM)
     set(SDL_FILESYSTEM_VITA 1)
     file(GLOB VITA_FILESYSTEM_SOURCES ${SDL2_SOURCE_DIR}/src/filesystem/vita/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${VITA_FILESYSTEM_SOURCES})
+    list(APPEND SOURCE_FILES ${VITA_FILESYSTEM_SOURCES})
     set(HAVE_SDL_FILESYSTEM TRUE)
   endif()
   if(SDL_JOYSTICK)
     set(SDL_JOYSTICK_VITA 1)
     file(GLOB VITA_JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/vita/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${VITA_JOYSTICK_SOURCES})
+    list(APPEND SOURCE_FILES ${VITA_JOYSTICK_SOURCES})
     set(HAVE_SDL_JOYSTICK TRUE)
   endif()
   if(SDL_POWER)
     set(SDL_POWER_VITA 1)
     file(GLOB VITA_POWER_SOURCES ${SDL2_SOURCE_DIR}/src/power/vita/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${VITA_POWER_SOURCES})
+    list(APPEND SOURCE_FILES ${VITA_POWER_SOURCES})
     set(HAVE_SDL_POWER TRUE)
   endif()
   if(SDL_THREADS)
@@ -2326,25 +2326,25 @@ elseif(VITA)
   endif()
   if(SDL_LOCALE)
     file(GLOB LOCALE_SOURCES ${SDL2_SOURCE_DIR}/src/locale/vita/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${LOCALE_SOURCES})
+    list(APPEND SOURCE_FILES ${LOCALE_SOURCES})
     set(HAVE_SDL_LOCALE TRUE)
   endif()
   if(SDL_TIMERS)
     set(SDL_TIMER_VITA 1)
     file(GLOB TIMER_SOURCES ${SDL2_SOURCE_DIR}/src/timer/vita/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${TIMER_SOURCES})
+    list(APPEND SOURCE_FILES ${TIMER_SOURCES})
     set(HAVE_SDL_TIMERS TRUE)
   endif()
   if(SDL_SENSOR)
     set(SDL_SENSOR_VITA 1)
     set(HAVE_SDL_SENSORS TRUE)
     file(GLOB VITA_SENSOR_SOURCES ${SDL2_SOURCE_DIR}/src/sensor/vita/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${VITA_SENSOR_SOURCES})
+    list(APPEND SOURCE_FILES ${VITA_SENSOR_SOURCES})
   endif()
   if(SDL_VIDEO)
     set(SDL_VIDEO_DRIVER_VITA 1)
     file(GLOB VITA_VIDEO_SOURCES ${SDL2_SOURCE_DIR}/src/video/vita/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${VITA_VIDEO_SOURCES})
+    list(APPEND SOURCE_FILES ${VITA_VIDEO_SOURCES})
     set(HAVE_SDL_VIDEO TRUE)
 
     if(VIDEO_VITA_PIB)
@@ -2435,12 +2435,12 @@ elseif(VITA)
 #  set(HAVE_ARMSIMD TRUE)
 #  set(SDL_ARM_SIMD_BLITTERS 1)
 #  file(GLOB ARMSIMD_SOURCES ${SDL2_SOURCE_DIR}/src/video/arm/pixman-arm-simd*.S)
-#  set(SOURCE_FILES ${SOURCE_FILES} ${ARMSIMD_SOURCES})
+#  list(APPEND SOURCE_FILES ${ARMSIMD_SOURCES})
 
 #  set(HAVE_ARMNEON TRUE)
 #  set(SDL_ARM_NEON_BLITTERS 1)
 #  file(GLOB ARMNEON_SOURCES ${SDL2_SOURCE_DIR}/src/video/arm/pixman-arm-neon*.S)
-#  set(SOURCE_FILES ${SOURCE_FILES} ${ARMNEON_SOURCES})
+#  list(APPEND SOURCE_FILES ${ARMNEON_SOURCES})
 
 #  set_property(SOURCE ${SDL2_SOURCE_DIR}/src/video/arm/pixman-arm-simd-asm.S PROPERTY LANGUAGE C)
 #  set_property(SOURCE ${SDL2_SOURCE_DIR}/src/video/arm/pixman-arm-neon-asm.S PROPERTY LANGUAGE C)
@@ -2460,44 +2460,44 @@ elseif(PSP)
   if(SDL_AUDIO)
     set(SDL_AUDIO_DRIVER_PSP 1)
     file(GLOB PSP_AUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/psp/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${PSP_AUDIO_SOURCES})
+    list(APPEND SOURCE_FILES ${PSP_AUDIO_SOURCES})
     set(HAVE_SDL_AUDIO TRUE)
   endif()
   if(SDL_FILESYSTEM)
     set(SDL_FILESYSTEM_PSP 1)
     file(GLOB PSP_FILESYSTEM_SOURCES ${SDL2_SOURCE_DIR}/src/filesystem/psp/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${PSP_FILESYSTEM_SOURCES})
+    list(APPEND SOURCE_FILES ${PSP_FILESYSTEM_SOURCES})
     set(HAVE_SDL_FILESYSTEM TRUE)
   endif()
   if(SDL_JOYSTICK)
     set(SDL_JOYSTICK_PSP 1)
     file(GLOB PSP_JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/psp/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${PSP_JOYSTICK_SOURCES})
+    list(APPEND SOURCE_FILES ${PSP_JOYSTICK_SOURCES})
     set(HAVE_SDL_JOYSTICK TRUE)
   endif()
   if(SDL_POWER)
     set(SDL_POWER_PSP 1)
     file(GLOB PSP_POWER_SOURCES ${SDL2_SOURCE_DIR}/src/power/psp/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${PSP_POWER_SOURCES})
+    list(APPEND SOURCE_FILES ${PSP_POWER_SOURCES})
     set(HAVE_SDL_POWER TRUE)
   endif()
   if(SDL_THREADS)
     set(SDL_THREAD_PSP 1)
     file(GLOB PSP_THREAD_SOURCES ${SDL2_SOURCE_DIR}/src/thread/generic/SDL_systls.c ${SDL2_SOURCE_DIR}/src/thread/psp/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${PSP_THREAD_SOURCES})
+    list(APPEND SOURCE_FILES ${PSP_THREAD_SOURCES})
     set(HAVE_SDL_THREADS TRUE)
   endif()
   if(SDL_TIMERS)
     set(SDL_TIMER_PSP 1)
     file(GLOB PSP_TIMER_SOURCES ${SDL2_SOURCE_DIR}/src/timer/psp/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${PSP_TIMER_SOURCES})
+    list(APPEND SOURCE_FILES ${PSP_TIMER_SOURCES})
     set(HAVE_SDL_TIMERS TRUE)
   endif()
   if(SDL_VIDEO)
     set(SDL_VIDEO_DRIVER_PSP 1)
     set(SDL_VIDEO_RENDER_PSP 1)
     file(GLOB PSP_VIDEO_SOURCES ${SDL2_SOURCE_DIR}/src/video/psp/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${PSP_VIDEO_SOURCES})
+    list(APPEND SOURCE_FILES ${PSP_VIDEO_SOURCES})
     set(SDL_VIDEO_OPENGL 1)
     set(HAVE_SDL_VIDEO TRUE)
   endif()
@@ -2519,57 +2519,57 @@ elseif(OS2)
   list(APPEND EXTRA_CFLAGS "-DOS2EMX_PLAIN_CHAR")
 
   file(GLOB CORE_SOURCES ${SDL2_SOURCE_DIR}/src/core/os2/*.c)
-  set(SOURCE_FILES ${SOURCE_FILES} ${CORE_SOURCES})
+  list(APPEND SOURCE_FILES ${CORE_SOURCES})
   if(NOT (HAVE_ICONV AND HAVE_ICONV_H))
     file(GLOB CORE_SOURCES ${SDL2_SOURCE_DIR}/src/core/os2/geniconv/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${CORE_SOURCES})
+    list(APPEND SOURCE_FILES ${CORE_SOURCES})
   endif()
 
   if(SDL_THREADS)
     set(SDL_THREAD_OS2 1)
     file(GLOB OS2_THREAD_SOURCES ${SDL2_SOURCE_DIR}/src/thread/os2/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${OS2_THREAD_SOURCES})
+    list(APPEND SOURCE_FILES ${OS2_THREAD_SOURCES})
     set(HAVE_SDL_THREADS TRUE)
   endif()
 
   if(SDL_TIMERS)
     set(SDL_TIMER_UNIX 1)
     file(GLOB OS2_TIMER_SOURCES ${SDL2_SOURCE_DIR}/src/timer/os2/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${OS2_TIMER_SOURCES})
+    list(APPEND SOURCE_FILES ${OS2_TIMER_SOURCES})
     set(HAVE_SDL_TIMERS TRUE)
   endif()
 
   if(SDL_LOADSO)
     set(SDL_LOADSO_OS2 1)
     file(GLOB OS2_LOADSO_SOURCES ${SDL2_SOURCE_DIR}/src/loadso/os2/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${OS2_LOADSO_SOURCES})
+    list(APPEND SOURCE_FILES ${OS2_LOADSO_SOURCES})
     set(HAVE_SDL_LOADSO TRUE)
   endif()
 
   if(SDL_FILESYSTEM)
     set(SDL_FILESYSTEM_OS2 1)
     file(GLOB FILESYSTEM_SOURCES ${SDL2_SOURCE_DIR}/src/filesystem/os2/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${FILESYSTEM_SOURCES})
+    list(APPEND SOURCE_FILES ${FILESYSTEM_SOURCES})
     set(HAVE_SDL_FILESYSTEM TRUE)
   endif()
 
   if(SDL_LOCALE)
     file(GLOB LOCALE_SOURCES ${SDL2_SOURCE_DIR}/src/locale/unix/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${LOCALE_SOURCES})
+    list(APPEND SOURCE_FILES ${LOCALE_SOURCES})
     set(HAVE_SDL_LOCALE TRUE)
   endif()
 
   if(SDL_VIDEO)
     set(SDL_VIDEO_DRIVER_OS2 1)
     file(GLOB OS2_VIDEO_SOURCES ${SDL2_SOURCE_DIR}/src/video/os2/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${OS2_VIDEO_SOURCES})
+    list(APPEND SOURCE_FILES ${OS2_VIDEO_SOURCES})
     set(HAVE_SDL_VIDEO TRUE)
   endif()
 
   if(SDL_AUDIO)
     set(SDL_AUDIO_DRIVER_OS2 1)
     file(GLOB OS2_AUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/os2/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${OS2_AUDIO_SOURCES})
+    list(APPEND SOURCE_FILES ${OS2_AUDIO_SOURCES})
     set(HAVE_SDL_AUDIO TRUE)
     list(APPEND EXTRA_LIBS mmpm2)
   endif()
@@ -2577,7 +2577,7 @@ elseif(OS2)
   if(SDL_JOYSTICK)
     set(SDL_JOYSTICK_OS2 1)
     file(GLOB OS2_JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/os2/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${OS2_JOYSTICK_SOURCES})
+    list(APPEND SOURCE_FILES ${OS2_JOYSTICK_SOURCES})
     set(HAVE_SDL_JOYSTICK TRUE)
   endif()
 
@@ -2603,59 +2603,59 @@ endif()
 if(NOT HAVE_SDL_AUDIO)
   set(SDL_AUDIO_DRIVER_DUMMY 1)
   file(GLOB AUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/dummy/*.c)
-  set(SOURCE_FILES ${SOURCE_FILES} ${AUDIO_SOURCES})
+  list(APPEND SOURCE_FILES ${AUDIO_SOURCES})
 endif()
 if(NOT HAVE_SDL_VIDEO)
   set(SDL_VIDEO_DRIVER_DUMMY 1)
   file(GLOB VIDEO_SOURCES ${SDL2_SOURCE_DIR}/src/video/dummy/*.c)
-  set(SOURCE_FILES ${SOURCE_FILES} ${VIDEO_SOURCES})
+  list(APPEND SOURCE_FILES ${VIDEO_SOURCES})
 endif()
 if(NOT HAVE_SDL_JOYSTICK)
   set(SDL_JOYSTICK_DUMMY 1)
   file(GLOB JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/dummy/*.c)
-  set(SOURCE_FILES ${SOURCE_FILES} ${JOYSTICK_SOURCES})
+  list(APPEND SOURCE_FILES ${JOYSTICK_SOURCES})
 endif()
 if(NOT HAVE_SDL_HAPTIC)
   set(SDL_HAPTIC_DUMMY 1)
   file(GLOB HAPTIC_SOURCES ${SDL2_SOURCE_DIR}/src/haptic/dummy/*.c)
-  set(SOURCE_FILES ${SOURCE_FILES} ${HAPTIC_SOURCES})
+  list(APPEND SOURCE_FILES ${HAPTIC_SOURCES})
 endif()
 if(NOT HAVE_SDL_SENSORS)
   set(SDL_SENSOR_DUMMY 1)
   file(GLOB SENSORS_SOURCES ${SDL2_SOURCE_DIR}/src/sensor/dummy/*.c)
-  set(SOURCE_FILES ${SOURCE_FILES} ${SENSORS_SOURCES})
+  list(APPEND SOURCE_FILES ${SENSORS_SOURCES})
 endif()
 if(NOT HAVE_SDL_LOADSO)
   set(SDL_LOADSO_DUMMY 1)
   file(GLOB LOADSO_SOURCES ${SDL2_SOURCE_DIR}/src/loadso/dummy/*.c)
-  set(SOURCE_FILES ${SOURCE_FILES} ${LOADSO_SOURCES})
+  list(APPEND SOURCE_FILES ${LOADSO_SOURCES})
 endif()
 if(NOT HAVE_SDL_FILESYSTEM)
   set(SDL_FILESYSTEM_DUMMY 1)
   file(GLOB FILESYSTEM_SOURCES ${SDL2_SOURCE_DIR}/src/filesystem/dummy/*.c)
-  set(SOURCE_FILES ${SOURCE_FILES} ${FILESYSTEM_SOURCES})
+  list(APPEND SOURCE_FILES ${FILESYSTEM_SOURCES})
 endif()
 if(NOT HAVE_SDL_LOCALE)
   set(SDL_LOCALE_DUMMY 1)
   file(GLOB LOCALE_SOURCES ${SDL2_SOURCE_DIR}/src/locale/dummy/*.c)
-  set(SOURCE_FILES ${SOURCE_FILES} ${LOCALE_SOURCES})
+  list(APPEND SOURCE_FILES ${LOCALE_SOURCES})
 endif()
 if(NOT HAVE_SDL_MISC)
   set(SDL_MISC_DUMMY 1)
   file(GLOB MISC_SOURCES ${SDL2_SOURCE_DIR}/src/misc/dummy/*.c)
-  set(SOURCE_FILES ${SOURCE_FILES} ${MISC_SOURCES})
+  list(APPEND SOURCE_FILES ${MISC_SOURCES})
 endif()
 
 # We always need to have threads and timers around
 if(NOT HAVE_SDL_THREADS)
   set(SDL_THREADS_DISABLED 1)
   file(GLOB THREADS_SOURCES ${SDL2_SOURCE_DIR}/src/thread/generic/*.c)
-  set(SOURCE_FILES ${SOURCE_FILES} ${THREADS_SOURCES})
+  list(APPEND SOURCE_FILES ${THREADS_SOURCES})
 endif()
 if(NOT HAVE_SDL_TIMERS)
   set(SDL_TIMER_DUMMY 1)
   file(GLOB TIMER_SOURCES ${SDL2_SOURCE_DIR}/src/timer/dummy/*.c)
-  set(SOURCE_FILES ${SOURCE_FILES} ${TIMER_SOURCES})
+  list(APPEND SOURCE_FILES ${TIMER_SOURCES})
 endif()
 
 if(NOT SDLMAIN_SOURCES)
diff --git a/cmake/sdlchecks.cmake b/cmake/sdlchecks.cmake
index a9b76601f..fd98ffb14 100644
--- a/cmake/sdlchecks.cmake
+++ b/cmake/sdlchecks.cmake
@@ -83,7 +83,7 @@ macro(CheckOSS)
         set(SDL_AUDIO_DRIVER_OSS_SOUNDCARD_H 1)
       endif()
       set(SDL_AUDIO_DRIVER_OSS 1)
-      set(SOURCE_FILES ${SOURCE_FILES} ${OSS_SOURCES})
+      list(APPEND SOURCE_FILES ${OSS_SOURCES})
       if(NETBSD OR OPENBSD)
         list(APPEND EXTRA_LIBS ossaudio)
       endif()
@@ -106,7 +106,7 @@ macro(CheckALSA)
     if(HAVE_LIBASOUND)
       set(HAVE_ALSA TRUE)
       file(GLOB ALSA_SOURCES ${SDL2_SOURCE_DIR}/src/audio/alsa/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${ALSA_SOURCES})
+      list(APPEND SOURCE_FILES ${ALSA_SOURCES})
       set(SDL_AUDIO_DRIVER_ALSA 1)
       if(SDL_ALSA_SHARED AND NOT HAVE_SDL_LOADSO)
         message_warn("You must have SDL_LoadObject() support for dynamic ALSA loading")
@@ -134,7 +134,7 @@ macro(CheckPipewire)
         if(PKG_PIPEWIRE_FOUND)
             set(HAVE_PIPEWIRE TRUE)
             file(GLOB PIPEWIRE_SOURCES ${SDL2_SOURCE_DIR}/src/audio/pipewire/*.c)
-            set(SOURCE_FILES ${SOURCE_FILES} ${PIPEWIRE_SOURCES})
+            list(APPEND SOURCE_FILES ${PIPEWIRE_SOURCES})
             set(SDL_AUDIO_DRIVER_PIPEWIRE 1)
             list(APPEND EXTRA_CFLAGS ${PKG_PIPEWIRE_CFLAGS})
             if(SDL_PIPEWIRE_SHARED AND NOT HAVE_SDL_LOADSO)
@@ -163,7 +163,7 @@ macro(CheckPulseAudio)
     if(PKG_PULSEAUDIO_FOUND)
       set(HAVE_PULSEAUDIO TRUE)
       file(GLOB PULSEAUDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/pulseaudio/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${PULSEAUDIO_SOURCES})
+      list(APPEND SOURCE_FILES ${PULSEAUDIO_SOURCES})
       set(SDL_AUDIO_DRIVER_PULSEAUDIO 1)
       list(APPEND EXTRA_CFLAGS ${PKG_PULSEAUDIO_CFLAGS})
       if(SDL_PULSEAUDIO_SHARED AND NOT HAVE_SDL_LOADSO)
@@ -192,7 +192,7 @@ macro(CheckJACK)
     if(PKG_JACK_FOUND)
       set(HAVE_JACK TRUE)
       file(GLOB JACK_SOURCES ${SDL2_SOURCE_DIR}/src/audio/jack/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${JACK_SOURCES})
+      list(APPEND SOURCE_FILES ${JACK_SOURCES})
       set(SDL_AUDIO_DRIVER_JACK 1)
       list(APPEND EXTRA_CFLAGS ${PKG_JACK_CFLAGS})
       if(SDL_JACK_SHARED AND NOT HAVE_SDL_LOADSO)
@@ -221,7 +221,7 @@ macro(CheckESD)
     if(PKG_ESD_FOUND)
       set(HAVE_ESD TRUE)
       file(GLOB ESD_SOURCES ${SDL2_SOURCE_DIR}/src/audio/esd/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${ESD_SOURCES})
+      list(APPEND SOURCE_FILES ${ESD_SOURCES})
       set(SDL_AUDIO_DRIVER_ESD 1)
       list(APPEND EXTRA_CFLAGS ${PKG_ESD_CFLAGS})
       if(SDL_ESD_SHARED AND NOT HAVE_SDL_LOADSO)
@@ -254,7 +254,7 @@ macro(CheckARTS)
       execute_process(CMD_ARTSLIBS ${ARTS_CONFIG} --libs
         OUTPUT_VARIABLE ARTS_LIBS OUTPUT_STRIP_TRAILING_WHITESPACE)
       file(GLOB ARTS_SOURCES ${SDL2_SOURCE_DIR}/src/audio/arts/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${ARTS_SOURCES})
+      list(APPEND SOURCE_FILES ${ARTS_SOURCES})
       set(SDL_AUDIO_DRIVER_ARTS 1)
       set(HAVE_ARTS TRUE)
       if(SDL_ARTS_SHARED AND NOT HAVE_SDL_LOADSO)
@@ -286,7 +286,7 @@ macro(CheckNAS)
     if(HAVE_NAS_H AND D_NAS_LIB)
       set(HAVE_NAS TRUE)
       file(GLOB NAS_SOURCES ${SDL2_SOURCE_DIR}/src/audio/nas/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${NAS_SOURCES})
+      list(APPEND SOURCE_FILES ${NAS_SOURCES})
       set(SDL_AUDIO_DRIVER_NAS 1)
       if(SDL_NAS_SHARED AND NOT HAVE_SDL_LOADSO)
         message_warn("You must have SDL_LoadObject() support for dynamic NAS loading")
@@ -316,7 +316,7 @@ macro(CheckSNDIO)
     if(HAVE_SNDIO_H AND D_SNDIO_LIB)
       set(HAVE_SNDIO TRUE)
       file(GLOB SNDIO_SOURCES ${SDL2_SOURCE_DIR}/src/audio/sndio/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${SNDIO_SOURCES})
+      list(APPEND SOURCE_FILES ${SNDIO_SOURCES})
       set(SDL_AUDIO_DRIVER_SNDIO 1)
       if(SDL_SNDIO_SHARED AND NOT HAVE_SDL_LOADSO)
         message_warn("You must have SDL_LoadObject() support for dynamic sndio loading")
@@ -344,7 +344,7 @@ macro(CheckFusionSound)
     if(PKG_FUSIONSOUND_FOUND)
       set(HAVE_FUSIONSOUND TRUE)
       file(GLOB FUSIONSOUND_SOURCES ${SDL2_SOURCE_DIR}/src/audio/fusionsound/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${FUSIONSOUND_SOURCES})
+      list(APPEND SOURCE_FILES ${FUSIONSOUND_SOURCES})
       set(SDL_AUDIO_DRIVER_FUSIONSOUND 1)
       list(APPEND EXTRA_CFLAGS ${PKG_FUSIONSOUND_CFLAGS})
       if(FUSIONSOUND_SHARED AND NOT HAVE_SDL_LOADSO)
@@ -433,7 +433,7 @@ macro(CheckX11)
       set(HAVE_SDL_VIDEO TRUE)
 
       file(GLOB X11_SOURCES ${SDL2_SOURCE_DIR}/src/video/x11/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${X11_SOURCES})
+      list(APPEND SOURCE_FILES ${X11_SOURCES})
       set(SDL_VIDEO_DRIVER_X11 1)
 
       # !!! FIXME: why is this disabled for Apple?
@@ -599,7 +599,7 @@ macro(WaylandProtocolGen _SCANNER _CODE_MODE _XML _PROTL)
         ARGS "${_CODE_MODE}" "${_XML}" "${_WAYLAND_PROT_C_CODE}"
     )
 
-    set(SOURCE_FILES ${SOURCE_FILES} "${_WAYLAND_PROT_C_CODE}")
+    list(APPEND SOURCE_FILES "${_WAYLAND_PROT_C_CODE}")
 endmacro()
 
 # Requires:
@@ -642,7 +642,7 @@ macro(CheckWayland)
       set(HAVE_SDL_VIDEO TRUE)
 
       file(GLOB WAYLAND_SOURCES ${SDL2_SOURCE_DIR}/src/video/wayland/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${WAYLAND_SOURCES})
+      list(APPEND SOURCE_FILES ${WAYLAND_SOURCES})
 
       # We have to generate some protocol interface code for some unstable Wayland features.
       file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/wayland-generated-protocols")
@@ -711,7 +711,7 @@ macro(CheckCOCOA)
     endif()
     if(HAVE_COCOA)
       file(GLOB COCOA_SOURCES ${SDL2_SOURCE_DIR}/src/video/cocoa/*.m)
-      set(SOURCE_FILES ${SOURCE_FILES} ${COCOA_SOURCES})
+      list(APPEND SOURCE_FILES ${COCOA_SOURCES})
       set(SDL_VIDEO_DRIVER_COCOA 1)
       set(HAVE_SDL_VIDEO TRUE)
     endif()
@@ -729,7 +729,7 @@ macro(CheckDirectFB)
     if(PKG_DIRECTFB_FOUND)
       set(HAVE_DIRECTFB TRUE)
       file(GLOB DIRECTFB_SOURCES ${SDL2_SOURCE_DIR}/src/video/directfb/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${DIRECTFB_SOURCES})
+      list(APPEND SOURCE_FILES ${DIRECTFB_SOURCES})
       set(SDL_VIDEO_DRIVER_DIRECTFB 1)
       set(SDL_VIDEO_RENDER_DIRECTFB 1)
       list(APPEND EXTRA_CFLAGS ${PKG_DIRECTFB_CFLAGS})
@@ -765,7 +765,7 @@ macro(CheckVivante)
       set(HAVE_SDL_VIDEO TRUE)
 
       file(GLOB VIVANTE_SOURCES ${SDL2_SOURCE_DIR}/src/video/vivante/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${VIVANTE_SOURCES})
+      list(APPEND SOURCE_FILES ${VIVANTE_SOURCES})
       set(SDL_VIDEO_DRIVER_VIVANTE 1)
       if(HAVE_VIVANTE_VDK)
         set(SDL_VIDEO_DRIVER_VIVANTE_VDK 1)
@@ -1127,7 +1127,7 @@ macro(CheckUSBHID)
     endif()
     set(SDL_JOYSTICK_USBHID 1)
     file(GLOB BSD_JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/bsd/*.c)
-    set(SOURCE_FILES ${SOURCE_FILES} ${BSD_JOYSTICK_SOURCES})
+    list(APPEND SOURCE_FILES ${BSD_JOYSTICK_SOURCES})
     list(APPEND EXTRA_CFLAGS ${USB_CFLAGS})
     list(APPEND EXTRA_LIBS ${USB_LIBS})
     set(HAVE_SDL_JOYSTICK TRUE)
@@ -1166,10 +1166,10 @@ macro(CheckHIDAPI)
 
   if(HAVE_HIDAPI)
     if(ANDROID)
-      set(SOURCE_FILES ${SOURCE_FILES} ${SDL2_SOURCE_DIR}/src/hidapi/android/hid.cpp)
+      list(APPEND SOURCE_FILES ${SDL2_SOURCE_DIR}/src/hidapi/android/hid.cpp)
     endif()
     if(IOS OR TVOS)
-      set(SOURCE_FILES ${SOURCE_FILES} ${SDL2_SOURCE_DIR}/src/hidapi/ios/hid.m)
+      list(APPEND SOURCE_FILES ${SDL2_SOURCE_DIR}/src/hidapi/ios/hid.m)
       set(SDL_FRAMEWORK_COREBLUETOOTH 1)
     endif()
     set(HAVE_SDL_HIDAPI TRUE)
@@ -1179,7 +1179,7 @@ macro(CheckHIDAPI)
       set(HAVE_SDL_JOYSTICK TRUE)
       set(HAVE_HIDAPI_JOYSTICK TRUE)
       file(GLOB HIDAPI_JOYSTICK_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/hidapi/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${HIDAPI_JOYSTICK_SOURCES})
+      list(APPEND SOURCE_FILES ${HIDAPI_JOYSTICK_SOURCES})
     endif()
   endif()
 endmacro()
@@ -1215,7 +1215,7 @@ macro(CheckRPI)
       set(HAVE_SDL_VIDEO TRUE)
       set(SDL_VIDEO_DRIVER_RPI 1)
       file(GLOB VIDEO_RPI_SOURCES ${SDL2_SOURCE_DIR}/src/video/raspberry/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${VIDEO_RPI_SOURCES})
+      list(APPEND SOURCE_FILES ${VIDEO_RPI_SOURCES})
       list(APPEND EXTRA_LIBS ${VIDEO_RPI_LIBRARIES})
       # !!! FIXME: shouldn't be using CMAKE_C_FLAGS, right?
       set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${VIDEO_RPI_INCLUDE_FLAGS} ${VIDEO_RPI_LIBRARY_FLAGS}")
@@ -1242,7 +1242,7 @@ macro(CheckKMSDRM)
       set(HAVE_SDL_VIDEO TRUE)
 
       file(GLOB KMSDRM_SOURCES ${SDL2_SOURCE_DIR}/src/video/kmsdrm/*.c)
-      set(SOURCE_FILES ${SOURCE_FILES} ${KMSDRM_SOURCES})
+      list(APPEND SOURCE_FILES ${KMSDRM_SOURCES})
 
       list(APPEND EXTRA_CFLAGS ${KMSDRM_CFLAGS})