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Cmake/docs/3.21/command/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 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.

Option De-duplication

The final set of options used for a target is constructed by accumulating options from the current target and the usage requirements of its dependencies. The set of options is de-duplicated to avoid repetition.

New in version 3.12: While beneficial for individual options, the de-duplication step can break up option groups. For example, -option A -option B becomes -option 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:-option A" "SHELL:-option B" becomes -option A -option B.


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)
    # lots of warnings and all warnings as errors
    add_compile_options(-Wall -Wextra -pedantic -Werror)

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.

The source file property COMPILE_OPTIONS adds options to one source file.

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