| CMP0092 |
| ------- |
| |
| MSVC warning flags are not in :variable:`CMAKE_<LANG>_FLAGS` by default. |
| |
| When using MSVC-like compilers in CMake 3.14 and below, warning flags |
| like ``/W3`` are added to :variable:`CMAKE_<LANG>_FLAGS` by default. |
| This is problematic for projects that want to choose a different warning |
| level programmatically. In particular, it requires string editing of the |
| :variable:`CMAKE_<LANG>_FLAGS` variables with knowledge of the |
| CMake builtin defaults so they can be replaced. |
| |
| CMake 3.15 and above prefer to leave out warning flags from the value of |
| :variable:`CMAKE_<LANG>_FLAGS` by default. |
| |
| This policy provides compatibility with projects that have not been updated |
| to expect the lack of warning flags. The policy setting takes effect as of |
| the first :command:`project` or :command:`enable_language` command that |
| initializes :variable:`CMAKE_<LANG>_FLAGS` for a given lanuage ``<LANG>``. |
| |
| .. 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 MSVC warning flags in the |
| default :variable:`CMAKE_<LANG>_FLAGS` cache entries. The ``NEW`` behavior |
| for this policy is to *not* place MSVC warning flags in the default cache |
| entries. |
| |
| This policy was introduced in CMake version 3.15. 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 |