CMake finds more than one main function

Question

I am trying to compile a project that has only one main function, but CMake find more.

My CMakeLists.txt is like:

Answer 1

In your executable you simply have 2 main functions (print out SRC_FILES by MESSAGE(${SRC_FILES})). One is in main.cpp and one in CMakeCXXCompilerId.cpp (which is a file that CMake generates to test if your CXX compiler works correctly). The GLOB_RECURSE probably finds and adds both of these files to SRC_FILES

Using FILE(GLOB ...) is tricky:

We do not recommend using GLOB to collect a list of source files from your source tree. If no CMakeLists.txt file changes when a source is added or removed then the generated build system cannot know when to ask CMake to regenerate.

You should list your source and header files in your CMakeLists.txt directly