Check CMAKE_POLICY_DEFAULT_CMP<NNNN> for a default when policy CMP<NNNN>
would otherwise be left unset. This allows users to set policies on the
command line when the project does not set them. One may do this to
quiet warnings or test whether a project will build with new behavior
without modifying code. There may also be cases when users want to
build an existing project release using new behavior for policies
unknown to the project at the time of the release.
Add the [.tweak] version component throughout the policy implementation.
Document all components for the cmake_policy(VERSION) command. Record
the tweak level in which each policy was introduced (0 for all current
policies). In generated documentation we report the tweak level only if
it is not zero. This preserves existing documentation.
This converts the CMake license to a pure 3-clause OSI-approved BSD
License. We drop the previous license clause requiring modified
versions to be plainly marked. We also update the CMake copyright to
cover the full development time range.
Isolation of policy changes inside scripts is important for protecting
the including context. This teaches include() and find_package() to
imply a cmake_policy(PUSH) and cmake_policy(POP) around the scripts they
load, with a NO_POLICY_SCOPE option to disable the behavior. This also
creates CMake Policy CMP0011 to provide compatibility. See issue #8192.
This teaches functions and macros to use policies recorded at creation
time when they are invoked. It restores the policies as a weak policy
stack entry so that any policies set by a function escape to its caller
as before.
This re-organizes the discussion of the policy stack in documentation of
the cmake_policy() command. The new organization clearer and easier to
extend with new information.
It is likely that projects or CMake modules in the future will need to
check the value of a policy setting. For example, if we add a policy
that affects the results of FindXYZ.cmake modules, the module code will
need to be able to check the policy.
- Add a paragraph introducing the policy mechanism
- Explicitly introduce the CMP<NNNN>, OLD, and NEW notation
- Note that setting policies by CMake version is preferred
- Fix SET signature to use CMP<NNNN> notation
- Add more details about the policy stack
- Remove CMP_0001 (no slash in target name) and restore
old CMAKE_BACKWARDS_COMPATIBILITY check for it
- Replace all checks of CMAKE_BACKWARDS_COMPATIBILITY
with cmLocalGenerator::NeedBackwardsCompatibility calls
- Create new CMP_0001 to determine whether or not
CMAKE_BACKWARDS_COMPATIBILITY is used.
(old = use, new = ignore)
- Show CMAKE_BACKWARDS_COMPATIBILITY in cache only when
CMP_0001 is set to OLD or WARN
- Update documentation of cmake_policy and cmake_minimum_required
to indicate their relationship and the 2.4 version boundary
- When no cmake policy version is set in top level makefile
implicitly call cmake_policy(VERSION 2.4) which restores
CMAKE_BACKWARDS_COMPATIBILITY and other 2.4 compatibility
- Fix tests MakeClean and Preprocess to call
cmake_policy(VERSION 2.6) because they depend on new policies
Brad King
Kitware Robot
Yury G. Kudryashov
Ken Martin