COMPILE_DEFINITIONS

.. versionadded:: 4.4

Preprocessor definitions for compiling a source file.

The COMPILE_DEFINITIONS property may be set to a semicolon-separated list of preprocessor definitions using the syntax VAR or VAR=value. Function-style definitions are not supported. CMake will automatically escape the value correctly for the native build system (note that CMake language syntax may require escapes to specify some values).

CMake will automatically drop some definitions that are not supported by the native build tool. :generator:Xcode does not support per-configuration definitions on source files.

.. include:: /include/COMPILE_DEFINITIONS_DISCLAIMER.rst

Contents of COMPILE_DEFINITIONS may use :manual:cmake-generator-expressions(7) with the syntax $<...>. See the :manual:cmake-generator-expressions(7) manual for available expressions. However, :generator:Xcode does not support per-config per-source settings, so expressions that depend on the build configuration are not allowed with that generator.

Related properties:

Use :prop_fs:COMPILE_OPTIONS to pass additional compile flags.
Use :prop_fs:INCLUDE_DIRECTORIES to pass additional include directories.

Related commands:

:command:add_compile_definitions for directory-wide settings
:command:target_compile_definitions for target-specific settings
:command:set_source_files_properties for source-specific settings