here's my source code directory structure.
some project
libs
mylib1
...
3rdlibs1
...
apps
myapp1
...
My requirments are as follows:
3rdlibs1 should be compiled when using command. like "cmake -G ...".
3rdlibs1 should be compiled as static library.
mylib1 should be modular.
mylib1 depends on 3rdlibs.
myapp depends on mylib1, and it should only link to mylib1. It shouldn't depends on 3rdlibs or system libraries.
Can you give me some sample code. I know ExternalProject_Add can help me to compile 3rdlibs. But I really don't know how to do it.
I think other people may also be interesting to this question.
If you have all your sources in single file system tree, it is better to use add_subdirectory than ExternalProject. ExternalProject is for projects which are truly external, e.g. on remote server or VCS repository. Unlike add_subdirectory which can create target of any type, ExternalProject can create only UTILITY target, similar to add_custom_target command. UTILITY targets have limitations, e.g. you can not use them in target_link_libraries command. Using add_subdirectory is much simpler.
Top-level:
cmake_minimum_required(VERSION 3.7)
project("some_project")
set(CMAKE_CXX_STANDARD 14)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
add_subdirectory(libs/3rdlibs1)
add_subdirectory(libs/mylib1)
add_subdirectory(apps/myapp1)
App:
project("myapp1")
set(SRC_FILES ...)
add_executable(myapp1 ${SRC_FILES})
target_link_libraries(myapp1 PRIVATE mylib1)
Lib. As I understand from your description, 3rdlibs1 is optional dependency of mylib1. Otherwise, how can myapp use mylib1 without 3rdlibs1?
project("mylib1")
option(THIRD_LIBS_SUPPORT "description" OFF)
set(SRC_FILES ...)
add_library(mylib1 STATIC ${SRC_FILES})
#PUBLIC means that both mylib1 and its dependents use the headers
target_include_directories(mylib1 PUBLIC "${PROJECT_SOURCE_DIR}/include")
if(THIRD_LIBS_SUPPORT)
#PUBLIC means that 3rdlibs1 will be linked to mylib1 dependents
target_link_libraries(mylib1 PUBLIC 3rdlibs1)
target_compile_definitions(mylib1 PUBLIC -DTHIRD_LIBS_SUPPORT)
endif()
Related
I am building a C++ project from Github and want to deploy the code to a remote Linux machine. This is all new to me.
The project has a main.cpp, which includes the various headers/sources like a library.
The CMake outputs an executable (to represent main.cpp) AND a separate static library. The project also uses OpenSSL, which I have linked statically.
I presume the OpenSSL functions are included within the static library? So when I deploy, I don't need to copy-over or install any OpenSSL on the remote machine?
Is it possible to modify the CMake so the application and the library are merged in to one file?
I am trying to make deployment as simple as copying over a single file, if this is possible.
Any additional advice/references are most-welcome.
UPDATE the CMake script:
cmake_minimum_required(VERSION 3.20)
set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/CMake;${CMAKE_MODULE_PATH}")
project(helloworld C CXX)
set (CMAKE_CXX_STANDARD 20)
set (CMAKE_BUILD_TYPE Release)
set (BUILD_MAIN TRUE)
set (BUILD_SHARED_LIBS FALSE)
set (OPENSSL_USE_STATIC_LIBS TRUE)
set(CMAKE_POSITION_INDEPENDENT_CODE ON)
set( HELLOWORLD_HEADERS helloworld/File1.h helloworld/File2.h )
set( HELLOWORLD_SOURCES helloworld/File1.cpp helloworld/File2.cpp )
# Static library
add_library( helloworld ${HELLOWORLD_SOURCES} ${HELLOWORLD_HEADERS} )
# Rapidjson
include_directories(/tmp/rapidjson/include/)
# OpenSSL
if (NOT OPENSSL_FOUND)
find_package(OpenSSL REQUIRED)
endif()
add_definitions(${OPENSSL_DEFINITIONS})
target_include_directories(helloworld PUBLIC $<BUILD_INTERFACE:${OPENSSL_INCLUDE_DIR}>)
target_link_libraries(helloworld PRIVATE ${OPENSSL_LIBRARIES})
set( HELLOWORLD_INCLUDE_DIRS ${CMAKE_CURRENT_SOURCE_DIR})
include(GNUInstallDirs)
target_include_directories(helloworld PUBLIC
$<BUILD_INTERFACE:${HELLOWORLD_INCLUDE_DIRS}/>
$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}/helloworld>
)
set_target_properties(helloworld PROPERTIES PUBLIC_HEADER "${HELLOWORLD_HEADERS}")
add_library(helloworld::helloworld ALIAS helloworld)
option(HELLOWORLD_INSTALL "Install HelloWorld" TRUE)
if (HELLOWORLD_INSTALL)
install(TARGETS helloworld
EXPORT helloworld
ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/helloworld/
)
configure_file("${CMAKE_CURRENT_LIST_DIR}/helloworld-config.cmake.in" "${CMAKE_BINARY_DIR}/helloworld-config.cmake" #ONLY)
install(FILES "${CMAKE_BINARY_DIR}/helloworld-config.cmake" DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/helloworld")
install(EXPORT helloworld
FILE helloworld-targets.cmake
NAMESPACE helloworld::
DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/helloworld
)
endif()
if (BUILD_MAIN)
add_executable(main main.cpp)
target_link_libraries(main helloworld)
endif()
ITNOA
I it is very helpful to make URL of your GitHub's project, but I write some public notes about that
In generally in CMake for static linking your library to your executable, you can write simple like below (from official CMake example)
add_library(archive archive.cpp zip.cpp lzma.cpp)
add_executable(zipapp zipapp.cpp)
target_link_libraries(zipapp archive)
In above example your executable file is just work without needing .a library file and you can simple copy single file.
if you want to make all of thing static, you make sure all dependencies make static link to your project, like CMake: how to produce binaries "as static as possible"
if you want to prevent library creation, Probably in your CMake file, you can find add_library command, and add_executable command. you can remove add_library command and add all sources to add_executable command.
for example add_executable(a.out main.cpp lib.cpp)
A bit of background on what I am trying to achieve: I already have a project that I have developed in CMake (it is collection of CMake projects: basically a state machine with a few helper libraries). Now, I want to develop a GUI in Qt that this state machine can control (and make it do stuff). However, for the life of me, I cannot figure out how to properly export the library which has the Qt classes and functions to another CMake package's executable. I am on Windows, and using the Mingw-w64 compiler and make program.
I was experimenting with 2 simple CMake projects, one which has a simple Qt form (which I just copied from and modified this repository and the corresponding youtube video given in the README), and the other which has the executable. I was trying to link the first project with the second project, however, whenever I build the autogenerated makefile, it fails in the end, saying that symbols are undefined (For example undefined reference to run_stuff::run_stuff()'). I apologize if the files are dirty, I have been trying out various stuff to no avail.
Things I have tried:
I have followed the answer here very carefully.
I have tried setting CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS to ON, as suggested by many sites (like this one) for running DLLs
I have tried making the library static (hence doing away with the need for DLLs)
I have tried setting the target_include_dirs from private to public and also commenting out that line. (not sure what that does, but okay)
However, no matter what I do, I always end with linking errors in the end, and my executable in the second project is not able to access any functions from the Qt project. Any suggestions on what I should try next? Would be really helpful if you could point out errors I am making in my CMakeLists.txt files (once again apologies for the messy code and CMakeLists)
My project CMake file looks like this:
cmake_minimum_required(VERSION 3.14)
# if (WIN32)
# set(CMAKE_SHARED_LIBRARY_PREFIX "")
# endif ()
set(CMAKE_MAKE_PROGRAM $ENV{MAKE})
set(CMAKE_CONFIGURATION_TYPES "Release;RelWithDebInfo" CACHE STRING "" FORCE)
set(CMAKE_SUPPORT_WINDOWS_EXPORT_ALL_SYMBOLS ON)
set(WINDOWS_EXPORT_ALL_SYMBOLS ON)
add_subdirectory(QT6CMake)
add_subdirectory(Exec)
The library CMake file:
cmake_minimum_required(VERSION 3.14)
if (WIN32)
project(MY_PROJECT LANGUAGES CXX)
elseif(UNIX)
project(MY_PROJECT)
endif()
set(CMAKE_CONFIGURATION_TYPES "Release;RelWithDebInfo" CACHE STRING "" FORCE)
#======================= INCLUSION OF Qt =======================#
set(CMAKE_INCLUDE_CURRENT_DIR ON)
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTOUIC ON)
set(CMAKE_PREFIX_PATH $ENV{QTDIR})
find_package(Qt6Core REQUIRED)
find_package(Qt6Widgets REQUIRED)
#=================== INCLUSION OF Project Files ====================#
set(FORMS_DIR "${CMAKE_SOURCE_DIR}/forms")
set(INCLUDE_DIR "${CMAKE_SOURCE_DIR}/include")
set(SOURCE_DIR "${CMAKE_SOURCE_DIR}/src")
include_directories(${FORMS_DIR})
include_directories(${INCLUDE_DIR})
include_directories(${SOURCE_DIR})
file(GLOB_RECURSE SOURCES
"${FORMS_DIR}/*.ui"
"${FORMS_DIR}/*.qrc"
"${INCLUDE_DIR}/*.h"
"${SOURCE_DIR}/*.cpp"
)
#=================== SETUP EXECTUABLE ====================#
# Enable debug logging on RELWITHDEBINFO configuration
set_property(DIRECTORY APPEND PROPERTY COMPILE_DEFINITIONS
$<$<CONFIG:RELWITHDEBINFO>:QT_MESSAGELOGCONTEXT>
)
# Add the forms directory to the AUTOUIC search paths
set(CMAKE_AUTOUIC_SEARCH_PATHS ${CMAKE_AUTOUIC_SEARCH_PATHS} ${FORMS_DIR})
# Add the executable
if (WIN32)
add_executable(MY_PROJECT WIN32 ${SOURCES})
elseif(UNIX)
add_executable(MY_PROJECT ${SOURCES})
endif()
# Add the target includes for MY_PROJECT
target_include_directories(MY_PROJECT PRIVATE ${FORMS_DIR})
target_include_directories(MY_PROJECT PRIVATE ${INCLUDE_DIR})
target_include_directories(MY_PROJECT PRIVATE ${SOURCE_DIR})
#===================== LINKING LIBRARIES =======================#
target_link_libraries(MY_PROJECT Qt6::Widgets)
The Exec CMake file:
cmake_minimum_required(VERSION 3.14)
project(somexec)
add_definitions(${MY_PROJECT_DEFINITIONS})
include_directories(${MY_PROJECT_INCLUDE_DIRS})
if (WIN32)
add_executable(${PROJECT_NAME} WIN32 main.cpp)
elseif(UNIX)
add_executable(${PROJECT_NAME} main.cpp)
endif()
target_link_libraries(${PROJECT_NAME} MY_PROJECT)
Here is the codebase.
EDIT:
Finally the code seems to be working, courtesy of Guillaume Racicot's multiple edits and fixes. I am going to leave this repository public in case anyone wants to see the codebase. Also, right now, I don't understand all the CMake commands that he has used, will try to understand those as well
The CMake code from the tutorial uses very old fashioned and outdated CMake practices. It works when creating a simple project, but won't work when doing libraries. To share files between projects, you need to export the CMake targets. You can do that by creating this file first:
cmake/yourlibrary-config.cmake
include(CMakeFindDependencyMacro)
# write it like you find_package of your cmake scripts
find_dependency(Qt6 COMPONENTS Core Widgets REQUIRED)
include("${CMAKE_CURRENT_LIST_DIR}/yourlibrary-targets.cmake")
Then, add this to your main project cmake files. You should have a CMake file that looks like this:
cmake_minimum_required(VERSION 3.21)
project(yourlibrary CXX)
# First, create your library. List all the files one by one. Don't use globs
add_library(yourlibrary src/mainwindow.cpp)
# Then add an alias of your library to enable target syntax
add_library(yourlibrary::yourlibrary ALIAS yourlibrary)
# Automatically generate Qt ui and moc
set_target_properties(yourlibrary PROPERTIES
AUTOUIC ON
AUTOMOC ON
AUTOUIC_SEARCH_PATHS forms
)
# Then, include gnuinstalldir to get the platform's standard directories:
include(GNUInstallDirs)
# Then, carefully add your include directories. All of your `target_include_directories` must look like this
target_include_directories(yourlibrary PUBLIC
$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include> # include directory in your build tree
$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}> # include directory when installed
)
# Then, include Qt and link qt
find_package(Qt6 COMPONENTS Core Widgets REQUIRED)
target_link_libraries(yourlibrary PUBLIC Qt6::Core Qt6::Widgets)
# Now, create the install script. We install all header files under `include/yourlibrary` to install them in `<prefix>/include/yourlibrary`:
install(
DIRECTORY include/yourlibrary
DESTINATION ${CMAKE_INSTALL_INCLUDEDIR} FILES_MATCHING PATTERN "*.hpp" PATTERN "*.h"
)
# We add `yourlibrary` target into the export set.
# The export set will contain all targets to be imported by the other project.
# It also installs the library to the install script so they are installed:
install(TARGETS yourlibrary EXPORT yourlibrary-targets
LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
)
# Now, we install the export set. This will generate a CMake file exporting all the target for other projects to use:
install(EXPORT yourlibrary-targets
DESTINATION "${CMAKE_INSTALL_DATADIR}/cmake/yourlibrary"
NAMESPACE yourlibrary::
)
# Now, we also export the current buildtree. Other project will be able to import the project directly from a build dir:
configure_file(cmake/yourlibrary-config.cmake yourlibrary-config.cmake COPYONLY)
export(
EXPORT yourlibrary-targets
NAMESPACE yourlibrary::
FILE "${PROJECT_BINARY_DIR}/yourlibrary-targets.cmake"
)
# The file we created earlier:
install(
FILES cmake/yourlibrary-config.cmake
DESTINATION "${CMAKE_INSTALL_DATADIR}/cmake/yourlibrary"
)
I omitted the installation of the generated headers since they are usually considered private for the project.
For the library, have a source tree looking like this:
yourlibrary
├── cmake
│ └── yourlibrary-config.cmake
├── forms
│ └── mainwindow.ui
├── include
│ └── yourlibrary
│ └── mainwindow.h
├── src
│ └── mainwindow.cpp
└── CMakeLists.txt
To use the library, you have two choices.
Either you embed it in your project using add_subdirectory(yourlibrary)
Either you build it separately and use find_package(yourlibrary REQUIRED)
You can't do both.
I usually prefer using find_package, but it require a package manager to avoid manually building all dependencies.
If you use add_subdirectory
Then remove find_package(yourlibrary REQUIRED) from your project. Simply add the directory and have your main project file look like this:
cmake_minimum_required(VERSION 3.21)
project(exec LANGUAGES CXX)
# Embed the project
add_subdirectory(yourlibrary)
add_executable(myexec main.cpp)
target_link_libraries(myexec PUBLIC yourlibrary::yourlibrary)
I assume a project tree like this:
SampleProject
├── yourlibrary
│ └── ...
├── CMakeLists.txt
└── main.cpp
If you build yourlibrary separately
First, build the library and (optionally) install it in a known location.
Now, you can build your library that uses Qt. You will need a CMakeLists.txt that looks like this:
cmake_minimum_required(VERSION 3.21)
project(myexec LANGUAGES CXX)
# also finds Qt and all
find_package(yourlibrary REQUIRED)
add_executable(myexec main.cpp)
target_link_libraries(myexec PUBLIC yourlibrary::yourlibrary)
If you install the yourlibrary library, it will simply work. If you want to use it from its build tree, simply run the CMake command with -DCMAKE_PREFIX_PATH=/path/to/yourlibrary/build. It should point to the build directory of the library, or the installation prefix if you installed it in a custom location.
I have a large C++ library, and want to do some testing with GTest.
At the moment, the build is handled with CMake, in particular there is one CMakeLists.txt file in the root directory like the following
make_minimum_required(VERSION 3.13.0)
project(mylib)
find_package(PkgConfig REQUIRED)
set(CMAKE_BUILD_WITH_INSTALL_RPATH ON)
set(CMAKE_INSTALL_RPATH "${CMAKE_CURRENT_SOURCE_DIR}/lib/protobuf/src/.libs/")
set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
SET(BASEPATH "${CMAKE_SOURCE_DIR}")
INCLUDE_DIRECTORIES("${BASEPATH}")
add_executable(mylib run.cpp)
add_subdirectory(src)
add_subdirectory(proto)
target_include_directories(mylib PUBLIC
${CMAKE_CURRENT_SOURCE_DIR}/lib/math
${CMAKE_CURRENT_SOURCE_DIR}/lib/protobuf/src
... some dirs ...
)
target_link_directories(mylib PRIVATE
... some libs ..
)
target_link_libraries(mylib
${CMAKE_CURRENT_SOURCE_DIR}/lib/math
${CMAKE_CURRENT_SOURCE_DIR}/lib/protobuf/src
.....
)
target_compile_options(mylib PUBLIC -D_REENTRANT -fPIC)
Then in the src directory and every sub-directory there is a CMakeLists.txt file, for example this is in src/
target_sources(mylib
PUBLIC
includes.hpp
)
add_subdirectory(algorithms)
add_subdirectory(collectors)
add_subdirectory(hierarchies)
add_subdirectory(mixings)
add_subdirectory(runtime)
add_subdirectory(utils)
My question here is the following: what is the least painful way to integrate GTest in the current project? I was thinking of having a test/ subdirectory, like I've seen here: Adding Googletest To Existing CMake Project
However this example requires that for each executable you manually list all the files it includes. Is there a quicker way to use the sources that are already added to 'mylib'?
You can split the current mylib executable target into two targets
mylib, a library target that is very much like the current mylib target, but without the run.cpp file
mylib_exe an executable target that compiles run.cpp and links to mylib
Now your test files can link to mylib.
I would like to create two executables: one executable for the application, and one for the testing of the application. To that end, I have the following in my CMakeLists.txt file:
include_directories(include)
file(GLOB SOURCE "src/*.cc")
file(GLOB TEST "test/*.cc")
add_executable(interest_calc ${SOURCE})
add_executable(interest_calc_test "src/interest_calc.cc" ${TEST})
Since both src and test directories contain main functions, I have to manually add source files to the "test" executable. Is there another, non-manual, way to add required source files to the "test" executable?
Further, is there a better way to test functionality than creating a separate test executable? If so, what/how?
One way to improve your process would be to pull the guts of your executable into a library, then have a nominal "main" executable which just calls into your library and a "test" executable which exercises the library however you want to test it.
This way, any changes you need to make go into the library and the executable build process is untouched.
Edit to show CMake with your example:
include_directories(include)
file(GLOB SOURCE "src/*.cc")
# Remove main from library, only needed for exec.
list(REMOVE_ITEM SOURCE "main.cc")
file(GLOB TEST "test/*.cc")
add_library(interest_calc_lib STATIC ${SOURCE})
add_executable(interest_calc "main.cc")
target_link_libraries(interest_calc interest_calc_lib)
add_executable(interest_calc_test ${TEST})
target_link_libraries(interest_calc_test interest_calc_lib)
There are already some good answers from Soeren and mascoj but I would like to give a more concrete recommendation.
When you already have a CMakeLists.txt for your executable and you like to add testing, I recommend adding a static dummy library. This library can have all the sources of the executable except the main method (it may be easiest to single out the main method in a separate file if you do not have that already). Using a static library will give you two benefits:
The final executable will behave exactly as your current one, so there is no need to deal with distribution of a new, shared library
You do not need to deal with exporting symbols or throwing exceptions across shared object boundaries
The changes to your CMakeLists.txt can be quite small. I will give an example here, assuming you use cmake 3.0 or newer. First, an example of CMakeLists.txt before adding the dummy library:
project(MyProject)
set(SOURCES src/First.cc src/Second.cc src/Third.cc)
add_executable(${PROJECT_NAME} ${SOURCES} src/Main.cc)
target_include_directories(${PROJECT_NAME}
${CMAKE_CURRENT_SOURCE_DIR}/include
${CMAKE_CURRENT_SOURCE_DIR}/src
${CMAKE_CURRENT_BINARY_DIR})
target_compile_options(${PROJECT_NAME}
$<$<CXX_COMPILER_ID:GNU>:-Wall;-pedantic)
target_compile_definitions(${PROJECT_NAME}
$<$<CONFIG:Debug>:DEBUG;_DEBUG>)
set_target_properties(${PROJECT_NAME}
PROPERTIES CXX_STANDARD 14)
target_link_libraries(${PROJECT_NAME}
Threads::Threads)
To add the dummy library and testing, you need to introduce a new target with a different name. I choose here to use ${PROJECT_NAME}_lib because this will be very non-intrusive on the CMakeLists.txt. Here is the updated version. Notice the use of ${PROJECT_NAME}_lib in place of ${PROJECT_NAME} in almost all places. Most properties are now passed down to the executable by making them PUBLIC. Only calls to set_target_properties() are not transitive and must be duplicated for library and executable.
project(MyProject)
set(SOURCES src/First.cc src/Second.cc src/Third.cc)
add_library(${PROJECT_NAME}_lib STATIC ${SOURCES})
add_executable(${PROJECT_NAME} src/Main.cc)
target_include_directories(${PROJECT_NAME}_lib PUBLIC
${CMAKE_CURRENT_SOURCE_DIR}/include
${CMAKE_CURRENT_SOURCE_DIR}/src
${CMAKE_CURRENT_BINARY_DIR})
target_compile_options(${PROJECT_NAME}_lib PUBLIC
$<$<CXX_COMPILER_ID:GNU>:-Wall;-pedantic)
target_compile_definitions(${PROJECT_NAME}_lib PUBLIC
$<$<CONFIG:Debug>:DEBUG;_DEBUG>)
set_target_properties(${PROJECT_NAME}_lib
PROPERTIES CXX_STANDARD 14)
set_target_properties(${PROJECT_NAME}
PROPERTIES CXX_STANDARD 14)
target_link_libraries(${PROJECT_NAME}
${PROJECT_NAME}_lib
Threads::Threads)
Now you can link your tests against ${PROJECT_NAME}_lib with a different main method.
You could do like this :
In the current CMakeLists.txt, put these lines :
add_subdirectory(src)
add_subdirectory(test)
and then, in each directories add a CMakeLists.txt that link correctly sources to each files.
About test, I've heard that CMake can do test automation, but I don't really know how it works.
In my opinion the best solution is to create a library (shared or static) and two executables (one for the main program and one for the test main). After that you should link the library against the two applications.
In this answer I write down a explanation with a little example how you could managed the project with cmake.
I have a set of files that I want to make into a library and then use that library in another project. This it how it looks like right now
cmake_minimum_required(VERSION 2.8)
aux_source_directory(. SRC_LIST)
SET(CMAKE_CXX_FLAGS "-std=c++11 -fopenmp -fPIC")
add_library (helperlibs lib1.cpp lib2.cpp lib3.cpp lib4.cpp )
INSTALL(TARGETS helperlibs
DESTINATION "${HOME}/lib"
)
INSTALL(FILES lib1.h lib2.h lib3.h lib4.h helperheader.h
DESTINATION "${HOME}/include/helperlibs"
)
In this code Lib4 depends on Lib1-3 and Lib3 depends on Lib1-2 and Lib2 depends on Lib1. Each of these cpp files also depend on a helperheader.h file that contains some definitions and structs.
In my project I have the following CMake file
cmake_minimum_required(VERSION 2.8)
aux_source_directory(. SRC_LIST)
SET( CMAKE_CXX_FLAGS "-std=c++11 -fopenmp -fPIC")
SET(MYINCS ${HOME}/include/helperlibs)
SET(MYLIBDIR ${HOME}/lib)
SET(MYLIBS ${MYLIBDIR}/libhelperlibs.a )
include_directories(${MYINCS})
add_executable(main main.cpp)
target_link_libraries(main ${MYLIBS})
So what I am wondering if you want to create a static library and link to from a another project using cmake is this the way you should write?
Embed the search paths into the library target as properties and create an export.
This way executables in the same build tree will find the library and its include files without you having to specify paths (they become implicit).
I needed to read the cmake documentation carefully a few times before it dawned on me how it should work.
http://www.cmake.org/cmake/help/v3.0/manual/cmake-packages.7.html#creating-packages
http://www.cmake.org/cmake/help/v3.0/manual/cmake-buildsystem.7.html
excerpt from a live example:
add_library(trustportal-util ${CMAKE_CURRENT_LIST_FILE} ${_source_files} ${_disabled_source_files} )
target_link_libraries(trustportal-util ${Boost_LIBRARIES})
if(APPLE)
find_library(SECURITY_FRAMEWORK Security)
target_link_libraries(trustportal-util ${SECURITY_FRAMEWORK})
else()
find_library(LIB_SSL ssl)
find_library(LIB_CRYPTO crypto)
target_link_libraries(trustportal-util ${LIB_SSL} ${LIB_CRYPTO})
endif()
target_compile_definitions(trustportal-util PUBLIC BOOST_MOVE_USE_STANDARD_LIBRARY_MOVE)
target_include_directories(trustportal-util PUBLIC ${Boost_INCLUDE_DIRS})
target_include_directories(trustportal-util PRIVATE
$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
$<INSTALL_INTERFACE:include>)
target_include_directories(trustportal-util SYSTEM PUBLIC
$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
$<INSTALL_INTERFACE:include>)
install(TARGETS trustportal-util
EXPORT trustportal-utilExport
DESTINATION lib
INCLUDES DESTINATION include
)
INSTALL(EXPORT trustportal-utilExport DESTINATION lib)
One option is to do what you are currently doing where you place the includes and libs in a common location, perhaps /usr/include and /usr/lib on linux, or ${HOME} on both Windows/Linux, up to you.
Another option is available if you use git. You can include the project inside another using submodules. Then use include_directory(${submodule}) and build and link directly for every project. The advantage of this approach is that dependencies are more localised. One problem with this method is if you recursively do this, you may end up with duplicates of some projects and cmake will complain that two libraries have the same name.