SYSTEM

Specifies that a target is a system target. This has the following effects:

• Entries of INTERFACE_INCLUDE_DIRECTORIES are treated as system include directories when compiling consumers. Entries of INTERFACE_SYSTEM_INCLUDE_DIRECTORIES are not affected, and will always be treated as system include directories.
• On Apple platforms, If the FRAMEWORK target property is true, the frameworks directory is treated as system.

For imported targets, this property defaults to true, which means that their INTERFACE_INCLUDE_DIRECTORIES and, if the FRAMEWORK target property is true, frameworks directory are treated as system directories by default. If their SYSTEM property is false, then their INTERFACE_INCLUDE_DIRECTORIES as well as frameworks will not be treated as system. Use the EXPORT_NO_SYSTEM property to change how a target's SYSTEM property is set when it is installed.

For non-imported targets, this target property is initialized from the SYSTEM directory property when the target is created.