diff options
Diffstat (limited to 'Help/policy/CMP0092.rst')
-rw-r--r-- | Help/policy/CMP0092.rst | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/Help/policy/CMP0092.rst b/Help/policy/CMP0092.rst new file mode 100644 index 0000000..8d3a288 --- /dev/null +++ b/Help/policy/CMP0092.rst @@ -0,0 +1,38 @@ +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 |