add_definitions

Add -D define flags to the compilation of source files.

.. code-block:: cmake

add_definitions(-DFOO -DBAR ...)

Adds definitions to the compiler command line for targets in the current directory, whether added before or after this command is invoked, and for the ones in sub-directories added after. This command can be used to add any flags, but it is intended to add preprocessor definitions.

.. note::

This command has been superseded by alternatives:

Use :command:add_compile_definitions to add preprocessor definitions.
Use :command:include_directories to add include directories.
Use :command:add_compile_options to add other options.

Flags beginning in -D or /D that look like preprocessor definitions are automatically added to the :prop_dir:COMPILE_DEFINITIONS directory property for the current directory. Definitions with non-trivial values may be left in the set of flags instead of being converted for reasons of backwards compatibility. See documentation of the :prop_dir:directory <COMPILE_DEFINITIONS>, :prop_tgt:target <COMPILE_DEFINITIONS>, :prop_sf:source file <COMPILE_DEFINITIONS> COMPILE_DEFINITIONS properties for details on adding preprocessor definitions to specific scopes and configurations.