| CMP0117 |
| ------- |
| |
| .. versionadded:: 3.20 |
| |
| MSVC RTTI flag ``/GR`` is not added to |
| :variable:`CMAKE_CXX_FLAGS <CMAKE_<LANG>_FLAGS>` by default. |
| |
| When using MSVC-like compilers in CMake 3.19 and below, the RTTI flag |
| ``/GR`` is added to :variable:`CMAKE_CXX_FLAGS <CMAKE_<LANG>_FLAGS>` by |
| default. This behavior is left from support for MSVC versions from Visual |
| Studio 2003 and below that did not enable RTTI by default. It is no longer |
| necessary. Furthermore, it is problematic for projects that want to change |
| to ``/GR-`` programmatically. In particular, it requires string editing of |
| the :variable:`CMAKE_CXX_FLAGS <CMAKE_<LANG>_FLAGS>` variable with knowledge |
| of the CMake builtin default so it can be replaced. |
| |
| CMake 3.20 and above prefer to leave out ``/GR`` from the value of |
| :variable:`CMAKE_CXX_FLAGS <CMAKE_<LANG>_FLAGS>` by default. |
| |
| This policy provides compatibility with projects that have not been updated |
| to expect the lack of the ``/GR`` flag. The policy setting takes effect as |
| of the first :command:`project` or :command:`enable_language` command that |
| initializes :variable:`CMAKE_CXX_FLAGS <CMAKE_<LANG>_FLAGS>`. |
| |
| .. note:: |
| |
| Once the policy has taken effect at the top of a project for a given |
| language, that choice must be used throughout the tree for that language. |
| In projects that have nested projects in subdirectories, be sure to |
| convert everything together. |
| |
| The ``OLD`` behavior for this policy is to place the MSVC ``/GR`` flag in the |
| default :variable:`CMAKE_CXX_FLAGS <CMAKE_<LANG>_FLAGS>` cache entry. The |
| ``NEW`` behavior for this policy is to *not* place the MSVC ``/GR`` flag in |
| the default cache entry. |
| |
| This policy was introduced in CMake version 3.20. Use the |
| :command:`cmake_policy` command to set it to ``OLD`` or ``NEW`` explicitly. |
| Unlike many policies, CMake version |release| does *not* warn |
| when this policy is not set and simply uses ``OLD`` behavior. |
| |
| .. include:: DEPRECATED.txt |