add_custom_command add_custom_target with sub-folders full example

This provides a full example on how to use cmake's add_custom_command and add_custom_target with different CMakeLists.txt in diferent folders.

Usage

• clone the repository
• cd add_custom_command_target_w_subfolders
• mkdir build; cd build
• cmake ..
• make (Here you see the comment "Generating ../../generator/out_gen/output.cpp"
• rm test
• make (Here you don't see the comment anymore)

Way it works

• Within the folder "generator" the corresponding CMakeLists.txt is called by the main one
• generate.sh takes the template "input.tmpl" file and generates the "output.cpp" within the "out_gen" folder
• Whenever "input.tmpl" is modified or "output.cpp" does not exist, the generte.sh command is called.
• A binary called "test" is created from "output.cpp"

Info

• The generate.sh script just copies input to output file.
• "input.tmpl" already has the source code that will go into "output.cpp"