Compiling a static executable with CMake

Question

for a project I need to create an executable that includes all the libraries that I used (opencv, cgal) in order to execute it on a computer that has not those libraries. Currently, this is my CMakeLists.txt (I use linux).

cmake_minimum_required(VERSION 2.8)
#set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -Wall")
set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -Wall -O2")
project( labeling )
set(CMAKE_FIND_LIBRARY_SUFFIXES ".a")
add_library(OpenCV STATIC IMPORTED)
add_library(CGAL STATIC IMPORTED COMPONENTS Core)
add_library(GMP STATIC IMPORTED)
find_package(OpenCV REQUIRED)
find_package(CGAL QUIET COMPONENTS Core )
find_library(GMP_LIBRARY gmp /usr/lib)

include(src)
include( ${CGAL_USE_FILE} )
include( CGAL_CreateSingleSourceCGALProgram )


set(EXECUTABLE_OUTPUT_PATH ../bin)
set(CMAKE_EXE_LINKER_FLAGS "-static-libgcc -static-libstdc++")

include_directories( src )
include_directories( ${OpenCV_INCLUDE_DIRS} )

file(GLOB_RECURSE nei_SRC "src/*.cpp")
add_executable( nei_segmentation ${nei_SRC})
target_link_libraries( nei_segmentation ${OpenCV_LIBS} ${GMP_LIBRARY})

In such a way only GMP and some other c++ libraries are included in my executable. My question is: How can I create a makefile in order to automatically including all the libraries in a static manner and creating only a "big" executable that contains all the libraries? Can you help me?

Answer 1

As global CMake settings, add these lines before add_executable, valid for gcc/clang:

set(CMAKE_FIND_LIBRARY_SUFFIXES ".a")
set(BUILD_SHARED_LIBS OFF)
set(CMAKE_EXE_LINKER_FLAGS "-static")

On Modern CMake (3.x+ - target_link_libraries doc), you can apply the flag to specific targets, in this way:

target_link_libraries(your_target_name -static)

If you're using MSVC, you have to set the compiler and linker flags:

set(CMAKE_FIND_LIBRARY_SUFFIXES ".lib")
target_compile_options(your_target_name [PUBLIC|PRIVATE] /MT)
target_link_options(your_target_name [PUBLIC|PRIVATE] /INCREMENTAL:NO /NODEFAULTLIB:MSVCRT)

or alternatively also:

set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")

and if you are using MFC, you need to specify the flag to 1 see here:

set(CMAKE_MFC_FLAG 1) 

Answer 2

Add these lines after add_executable(MyExec "main.c") (for example) :

target_link_libraries(MyExec PUBLIC "-static")

or before: link_libraries("-static")