Cmake link library target link error - c++

Question

Hi I have problem with linkg Glfw and other libraries using cmake.
From command line i compile like this
g++ main.cpp -lGL -lGLU -lGLEW -lglfw
But I wanted to use cmake for compiling. I tried to use target_linkg_libraries but this produce error
CMake Error at CMakeLists.txt:18 (target_link_libraries): Cannot
specify link libraries for target "GL" which is not built by this
project.
I tried do this using add definitions. I dont see error but this don't link libraries.
cmake_minimum_required (VERSION 2.6)
project (test)
find_package(OpenGL REQUIRED)
find_package(GLEW REQUIRED)
ADD_DEFINITIONS(
-lGL
-lGLU
-lGLEW
-lglfw
)
add_executable(test.out
main.cpp
)
target_link_libraries(GL GLU GLEW glfw)

Answer 1

The syntax for target_link_libraries is:
target_link_libraries(your_executable_name libraries_list)
And you don't have to add add_definition statements (target_link_libraries adds this options)
There are also some useful variables provided by OpenGL and GLEW packages.
Your CMakeLists.txt should be like:
cmake_minimum_required (VERSION 2.6)
project (test)
find_package(OpenGL REQUIRED)
find_package(GLEW REQUIRED)
include_directories(${OPENGL_INCLUDE_DIR} ${GLEW_INCLUDE_DIRS})
add_executable(test
main.cpp
)
target_link_libraries(test ${OPENGL_LIBRARIES} ${GLEW_LIBRARIES})
One important detail to keep in mind is to place the target_link_libraries after the add_executable (or add_library) line.