Adds options to the compilation of source files.

add_compile_options(<option> ...)

Adds options to the compiler command line for targets in the current directory and below that are added after this command is invoked. See documentation of the directory and target COMPILE_OPTIONS properties.

This command can be used to add any options, but alternative commands exist to add preprocessor definitions (target_compile_definitions() and add_compile_definitions()) or include directories (target_include_directories() and include_directories()).

Arguments to add_compile_options may use “generator expressions” with the syntax $<...>. See the cmake-generator-expressions(7) manual for available expressions. See the cmake-buildsystem(7) manual for more on defining buildsystem properties.

The final set of compile options used for a target is constructed by accumulating options from the current target and the usage requirements of it dependencies. The set of options is de-duplicated to avoid repetition. While beneficial for individual options, the de-duplication step can break up option groups. For example, -D A -D B becomes -D A B. One may specify a group of options using shell-like quoting along with a SHELL: prefix. The SHELL: prefix is dropped and the rest of the option string is parsed using the separate_arguments() UNIX_COMMAND mode. For example, "SHELL:-D A" "SHELL:-D B" becomes -D A -D B.