Yongtao Hu's blog

CMake sumup

Posted on Edited on Disqus:

CMakeLists.txt for Lib project:

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# add path of headers to include_directories
include_directories(include)

# STATIC for static lib, and SHARED for dynamic
FILE(GLOB SOURCES
	src/*.h
    src/*.cpp
)
add_library(mylib STATIC ${SOURCES})

# link libs, list all of them
target_link_libraries(mylib
    -lib-name-.lib
)

CMakeLists.txt for EXE project:

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# Set the minimum required version of cmake.
cmake_minimum_required(VERSION 2.6)

# Set the entire solution name.
project(testProject)

# Add path of headers to include_directories.
include_directories(include)
include_directories(lib/mylib)
include_directories(external/-external-lib-/include)

# Add an executable to the project using the specified source files.
file(GLOB SOURCES
    src/*.*
	lib/-external-lib-/source/*.h
    lib/-external-lib-/source/*.cpp
    test/main.cpp
)
add_executable(${PROJECT_NAME} ${SOURCES})

# add mylib lib project
add_subdirectory(lib/mylib)
target_link_libraries(${PROJECT_NAME} mylib)

# add opencv lib
find_package(OpenCV 2 REQUIRED)
include_directories(${OPENCV_INCLUDE_DIRS})
link_directories(${OPENCV_LIBRARY_DIRS})
add_definitions(${OPENCV_DEFINITIONS})
target_link_libraries(${PROJECT_NAME}${OpenCV_LIBS})

Remarks:

  1. For add_executable(): actually there is no need to add headers here, but is essential to load them also in project view.
  2. To use name that contains spaces, use \ before spaces to escape them.
  3. To group source files in VS (e.g. put given source files into new folder under VS), use
    • source_group(<name> FILES <src>...) (use ${SOURCES} for files list defined earlier), or
    • source_group(<name> REGULAR_EXPRESSION <regex>) (e.g. use .*..* for normal *.*)
  4. Link different libraries for Debug and Release mode: 
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      target_link_libraries(testProj
          debug -path-to-debug-lib-/lib_debug.lib
    optimized -path-to-release-lib-/lib.lib
      )
  5. CMake for setting highest warning level can be: 
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    # set highest warnings level, and treat them as errors
    if(MSVC)
        # c++
        if(CMAKE_CXX_FLAGS MATCHES "/W[0-4]")
            string(REGEX REPLACE "/W[0-4]" "/W4 /WX" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
        else()
            set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /W4 /WX")
        endif()

        # c
        if(CMAKE_C_FLAGS MATCHES "/W[0-4]")
            string(REGEX REPLACE "/W[0-4]" "/W4 /WX" CMAKE_C_FLAGS "${CMAKE_C_FLAGS}")
        else()
            set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} /W4 /WX")
        endif()
    elseif(CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_GNUCXX)
        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Werror -Wconversion -Wno-long-long -pedantic")
    elseif(CMAKE_COMPILER_IS_GNUC)
        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Werror -Wconversion -Wno-long-long -pedantic")
    endif()
  6. Enable OpenMP: 
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    # enable openmp
    find_package(OpenMP)
    if (OPENMP_FOUND)
    	set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${OpenMP_C_FLAGS}")
    	set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}")
    endif()
  7. for copying all needed data files to binary dir (when cmake), there are two ways:
    • List all the files, e.g., 
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      file(GLOB files_needed
      	test/test-data/*.*
      	lib/-external-lib-/models/*.dat
      	lib/-matlab-/*.m
      )
      file(COPY ${files_needed} DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
    • List only the folders that contain the data, e.g., 
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      file(GLOB files_needed
      	test/test-data
      	lib/-external-lib-/models
      	lib/-matlab-
      )
      file(COPY ${files_needed} DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
      The difference is that: the first method only copy the listed files to the binary dir without directory structure, while the second will copy all the files in these folders, as well as with directory structure (only the least parent will retain), i.e. there will be three folders named test-data, models and -matlab- in the binary dir after copying.