Fixed bug 4092 - CMake support for building everything in the "test" directory

Eric Wasylishen

Patch to support building the tests with cmake.
Disabled by default, use: "cmake .. -DSDL_TEST=YES" to enable the tests.

Tested on macOS 10.13 with the ninja, makefile, and Xcode generators, and Windows 10 with the Visual Studio 2017 generator.

CMakeLists.txt

@@ -340,6 +340,7 @@ set(SDL_SHARED ${SDL_SHARED_ENABLED_BY_DEFAULT} CACHE BOOL "Build a shared versi
 set(SDL_STATIC ON CACHE BOOL "Build a static version of the library")
 
 dep_option(SDL_STATIC_PIC      "Static version of the library should be built with Position Independent Code" OFF "SDL_STATIC" OFF)
+set_option(SDL_TEST            "Build the test directory" OFF)
 
 # General source files
 file(GLOB SOURCE_FILES
@@ -1746,6 +1747,15 @@ if(SDL_STATIC)
   target_include_directories(SDL2-static PUBLIC $<INSTALL_INTERFACE:include>)
 endif()
 
+##### Tests #####
+
+if(SDL_TEST)
+  file(GLOB TEST_SOURCES ${SDL2_SOURCE_DIR}/src/test/*.c)
+  add_library(SDL2_test STATIC ${TEST_SOURCES})
+  
+  add_subdirectory(test)
+endif()
+
 ##### Installation targets #####
 install(TARGETS ${_INSTALL_LIBS} EXPORT SDL2Targets
   LIBRARY DESTINATION "lib${LIB_SUFFIX}"