add_compile_options

Add options to the compilation of source files.

add_compile_options(<option> ...)

Adds options to the COMPILE_OPTIONS directory property. These options are used when compiling targets from the current directory and below.

Arguments

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 or link 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.

Example

Since different compilers support different options, a typical use of this command is in a compiler-specific conditional clause:

if (MSVC)
    # warning level 4 and all warnings as errors
    add_compile_options(/W4 /WX)
else()
    # lots of warnings and all warnings as errors
    add_compile_options(-Wall -Wextra -pedantic -Werror)
endif()

See Also

This command can be used to add any options. However, for adding preprocessor definitions and include directories it is recommended to use the more specific commands add_compile_definitions() and include_directories().

The command target_compile_options() adds target-specific options.