CMAKECFLAGSRELEASE
CMAKE_C_FLAGS_RELEASE is a CMake cache variable that specifies the command-line options passed to the C compiler when building in the Release configuration. It is part of a family of per-configuration flags such as CMAKE_C_FLAGS_DEBUG and CMAKE_C_FLAGS_RELWITHDEBINFO, used by CMake to tailor compiler behavior for different build types. The value is a single string containing space-separated flags and is appended to the compiler invocation by the build system. Note that the conventional, documented name is CMAKE_C_FLAGS_RELEASE; there is no standard variable named CMAKECFLAGSRELEASE.
Usage depends on the generator. For single-configuration generators (such as Unix Makefiles or Ninja), the Release
Setting options can be done by passing flags on the command line with cmake -DCMAKE_C_FLAGS_RELEASE="-O3 -DNDEBUG" ..,
Modern CMake practice encourages using target_compile_options for per-target and per-configuration options, or generator expressions to apply
Note: The variable name is language-specific; there are analogous variables for C++: CMAKE_CXX_FLAGS_RELEASE, and the non-config-specific