CMake target to just compile a source file

Question

I am writing a header-only library using C++17. I would like to include it in a "dummy" source file:

#include "my/library.h"
// EOF

The purpose is to ensure the library properly includes all of its dependencies. I also want to run static analyzers on it and compile it with as many compiler checks enabled as is practical.

To create a normal executable target I need to add the main() function, otherwise the linking stage will fail. I guess I can also create a static library target, which should work correctly, although it will create an artifact I do not need.

Is there any other alternative?

Answer 1

CMake can create a simple Object library, which will only be a .o or .obj file:

The OBJECT library type defines a non-archival collection of object files resulting from compiling the given source files.

To do this, use the OBJECT keyword with the add_library() command:

add_library(MyObj OBJECT ${CMAKE_CURRENT_SOURCE_DIR}/library.cpp)
target_include_directories(MyObj PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

You can later reference the object file(s) to be compiled into other libraries or executables:

add_library(MyLibrary STATIC 
    $<TARGET_OBJECTS:MyObj> 
    MyOtherSource.cpp 
    HelpersFunctions.cpp
)