New in version 3.1.

Boolean specifying whether compiler specific extensions are requested.

This property specifies whether compiler specific extensions should be used. For some compilers, this results in adding a flag such as -std=gnu11 instead of -std=c11 to the compile line. This property is ON by default. The basic C standard level is controlled by the C_STANDARD target property.

See the cmake-compile-features(7) manual for information on compile features and a list of supported compilers.

This property is initialized by the value of the CMAKE_C_EXTENSIONS variable if it is set when a target is created.