| CMP0025 |
| ------- |
| |
| Compiler id for Apple Clang is now ``AppleClang``. |
| |
| CMake 3.0 and above recognize that Apple Clang is a different compiler |
| than upstream Clang and that they have different version numbers. |
| CMake now prefers to present this to projects by setting the |
| :variable:`CMAKE_<LANG>_COMPILER_ID` variable to ``AppleClang`` instead |
| of ``Clang``. However, existing projects may assume the compiler id for |
| Apple Clang is just ``Clang`` as it was in CMake versions prior to 3.0. |
| Therefore this policy determines for Apple Clang which compiler id to |
| report in the :variable:`CMAKE_<LANG>_COMPILER_ID` variable after |
| language ``<LANG>`` is enabled by the :command:`project` or |
| :command:`enable_language` command. The policy must be set prior |
| to the invocation of either command. |
| |
| The OLD behavior for this policy is to use compiler id ``Clang``. The |
| NEW behavior for this policy is to use compiler id ``AppleClang``. |
| |
| This policy was introduced in CMake version 3.0. Use the |
| :command:`cmake_policy` command to set this policy to OLD or NEW explicitly. |
| Unlike most policies, CMake version |release| does *not* warn |
| by default when this policy is not set and simply uses OLD behavior. |
| See documentation of the |
| :variable:`CMAKE_POLICY_WARNING_CMP0025 <CMAKE_POLICY_WARNING_CMP<NNNN>>` |
| variable to control the warning. |
