Summer Adventure 2018: Learning CMake #2
It has been two days since my last wrestle with CMake. In this time I continued to play around with the build system and test my various hypotheses about the way the system works. To provide at least the minimal structure necessary to articulate the experience, from henceforth I will try to recount and explain what I did in the order I did it in. Built-In Variables I wanted to test if my theory on how the setting of various global, provided variables affected the build chain (variables such as PROJECT_SOURCE_DIR, CMAKE_BINARY_DIR, etc). To that end I had a generated header file define the various variables as macros and my C++ printed these out. My theory was correct in that setting these variables changed as I predicted them to. However, I came to realise these variables, with the exception of output directories like CMAKE_RUNTIME_OUTPUT_DIR and CMAKE_ARCHIVE_OUTPUT_DIR, are intended to be used read-only and changing them once CMake has begun has no effect. It made sense to me peo