CMakeLists Multiple Source Files - c

Question

Hi I have a directory called "Question 1" with the following structure:
.idea
cmake-build-debug
1a.c
1b.c
1c.c
CMakeLists.txt
.idea and cmake-build-debug are folders containing other data which come default when creating a project (I'm using CLion), the other 3 are my source files i.e. 1a.c, 1b.c, 1c.c. My CMakeLists.txt file contains the following:
cmake_minimum_required(VERSION 3.7)
project(CLion)
set(CMAKE_C_STANDARD 99)
set(SOURCE_FILES 1b.c)
add_executable(CLion ${SOURCE_FILES})
As you can imagine per above I can only run the source file 1b.c. How do I edit CMakeLists.txt so that I can build an executable for each source file?

Answer 1

Each add_executable() call in your CMakeLists.txt specifies a separate executable to build. Since you want three executables, you need three such calls.
Furthermore, each executable needs a different name. In the case where each executable is built from its own source file, it is conventional for the names of the sources and executables to be related. In particular, I would expect the executable built from 1b.c to be named 1b.
Putting that together, here's one way to do it:
cmake_minimum_required(VERSION 3.7)
project(CLion)
set(CMAKE_C_STANDARD 99)
add_executable(1a 1a.c)
add_executable(1b 1b.c)
add_executable(1c 1c.c)
Note that you don't need to use a variable to designate the source files for an executable. Moreover, if you want to use variables then there is nothing special about the variable name SOURCE_FILES. For example, you could needlessly complicate the above example by introducing per-target source variables, like so:
cmake_minimum_required(VERSION 3.7)
project(CLion)
set(CMAKE_C_STANDARD 99)
set(SOURCES_1A 1a.c)
set(SOURCES_1B 1b.c)
set(SOURCES_1C 1c.c)
add_executable(1a ${SOURCES_1A})
add_executable(1b ${SOURCES_1B})
add_executable(1c ${SOURCES_1C})