[SOLVED] Specifying source code for add_library in cmake

Issue

I am trying to understand this package meant to be built with cmake. I am having trouble understanding how the CMakeLists.txt of the same package is finding the source code needed to create a shared library file. Specifically, in the line (Line13 of the same file):

add_library(HelloWorld SHARED HelloWorld)

the first HelloWorld is the target's name & the 2nd HelloWorld is supposed to be the source (code). But there is no source file called HelloWorld in the same directory. There are only HelloWorld.hh & HelloWorld.cc files. And there is a class called HelloWorld in the hello_world namespace in the .cc & .hh files.

So, does the build tool automatically search for files of any extension starting with the name HelloWorld? How does the above Line13 work? I'm using cmake 3.22.1 & the build is passing.

Thanks!

Solution

Refer to CMake policy CMP0115.

The OLD behavior for this policy is to implicitly append known extensions to source files if they can't be found.

In CMake 3.22, if the source extension isn't mentioned and the cmake_policy() command is not sent, the OLD behavior is used and a warning is shown encouraging developers to mention the extension explicitly.

Answered By - PhiloRobotist

Answer Checked By - Katrina (WPSolving Volunteer)