Answers

The following are the answers to this chapter’s questions:

1. Commands that are added with add_custom_command are executed at build time, while commands that are added with execute_process are executed at configuration time.
2. One signature is used to create custom build steps, while the other is used to generate files.
3. Only POST_BUILD is reliably supported across all generators.
4. Variables can be defined either as ${VAR} or @VAR@.
5. Variable substitution can be controlled by either passing @ONLY, which only replaces variables defined as @VAR@, or by specifying the COPYONLY option, which does not perform any substitution at all.
6. With cmake -E, common tasks can be executed directly. With cmake -P, .cmake files can be executed as scripts.