kc3-lang/SDL

2017-10-12T08:47:02

Fixed bug 3866 - CMake error when trying to make the 'uninstall' target when it already exists Steve Robinson In my project, the 'uninstall' target is already created by the glew library. I get this error when SDL2 tries to create it: CMake Error at _build/3rdparty/SDL2/SDL2-2.0.6/CMakeLists.txt:1816 (add_custom_target): add_custom_target cannot create target "uninstall" because another target with the same name already exists. The existing target is a custom target created in source directory "D:/Code/sdl2-tutorial/_build/3rdparty/glew/glew-2.1.0/build/cmake". See documentation for policy CMP0002 for more details. To fix it, go to the bottom of the SDL2 CMakeLists.txt file. Add an if statement to check for the existence of the target before creating it. The end result looks like this: if(NOT TARGET uninstall) configure_file( "${CMAKE_CURRENT_SOURCE_DIR}/cmake_uninstall.cmake.in" "${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake" IMMEDIATE @ONLY) add_custom_target(uninstall COMMAND ${CMAKE_COMMAND} -P ${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake) endif() This is how the glew library deals with this possibility in their CMakeLists.txt file.

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c13794a..1a36967 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1808,10 +1808,12 @@ endif()
 
 ##### Uninstall target #####
 
-configure_file(
-    "${CMAKE_CURRENT_SOURCE_DIR}/cmake_uninstall.cmake.in"
-    "${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake"
-    IMMEDIATE @ONLY)
-
-add_custom_target(uninstall
-    COMMAND ${CMAKE_COMMAND} -P ${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake)
+if(NOT TARGET uninstall)
+  configure_file(
+      "${CMAKE_CURRENT_SOURCE_DIR}/cmake_uninstall.cmake.in"
+      "${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake"
+      IMMEDIATE @ONLY)
+
+  add_custom_target(uninstall
+      COMMAND ${CMAKE_COMMAND} -P ${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake)
+endif()