Default value for C_EXTENSIONS property of targets.
This variable is used to initialize the C_EXTENSIONS property on all targets. See that target property for additional information.
See the cmake-compile-features(7) manual for information on compile features and a list of supported compilers.
© 2000–2018 Kitware, Inc. and Contributors
Licensed under the BSD 3-clause License.
https://cmake.org/cmake/help/v3.12/variable/CMAKE_C_EXTENSIONS.html