Policies in CMake are used to preserve backward compatible behavior
across multiple releases. When a new policy is introduced, newer CMake
versions will begin to warn about the backward compatible behavior. It
is possible to disable the warning by explicitly requesting the OLD, or
backward compatible behavior using the
It is also possible to request
NEW, or non-backward compatible behavior
for a policy, also avoiding the warning. Each policy can also be set to
OLD behavior explicitly on the command line with the
A policy is a deprecation mechanism and not a reliable feature toggle.
A policy should almost never be set to
OLD, except to silence warnings
in an otherwise frozen or stable codebase, or temporarily as part of a
larger migration path. The
OLD behavior of each policy is undesirable
and will be replaced with an error condition in a future release.
cmake_minimum_required() command does more than report an
error if a too-old version of CMake is used to build a project. It
also sets all policies introduced in that CMake version or earlier to
NEW behavior. To manage policies without increasing the minimum required
CMake version, the
if(POLICY) command may be used:
if(POLICY CMP0990) cmake_policy(SET CMP0990 NEW) endif()
This has the effect of using the
NEW behavior with newer CMake releases which
users may be using and not issuing a compatibility warning.
The setting of a policy is confined in some cases to not propagate to the
parent scope. For example, if the files read by the
find_package() command contain a use of
that policy setting will not affect the caller by default. Both commands accept
NO_POLICY_SCOPE keyword to control this behavior.
CMAKE_MINIMUM_REQUIRED_VERSION variable may also be used
to determine whether to report an error on use of deprecated macros or
- CMP0063: Honor visibility properties for all target types.
- CMP0062: Disallow install() of export() result.
- CMP0061: CTest does not by default tell make to ignore errors (-i).
- CMP0060: Link libraries by full path even in implicit directories.
- CMP0059: Do not treat DEFINITIONS as a built-in directory property.
- CMP0058: Ninja requires custom command byproducts to be explicit.
- CMP0057: Support new IN_LIST if() operator.
- CMP0050: Disallow add_custom_command SOURCE signatures.
- CMP0049: Do not expand variables in target source entries.
- CMP0048: project() command manages VERSION variables.
- CMP0047: Use QCC compiler id for the qcc drivers on QNX.
- CMP0046: Error on non-existent dependency in add_dependencies.
- CMP0045: Error on non-existent target in get_target_property.
- CMP0044: Case sensitive Lang_COMPILER_ID generator expressions.
- CMP0043: Ignore COMPILE_DEFINITIONS_Config properties.
- CMP0042: MACOSX_RPATH is enabled by default.
- CMP0041: Error on relative include with generator expression.
- CMP0040: The target in the TARGET signature of add_custom_command() must exist.
- CMP0039: Utility targets may not have link dependencies.
- CMP0038: Targets may not link directly to themselves.
- CMP0037: Target names should not be reserved and should match a validity pattern.
- CMP0036: The build_name command should not be called.
- CMP0035: The variable_requires command should not be called.
- CMP0034: The utility_source command should not be called.
- CMP0033: The export_library_dependencies command should not be called.
- CMP0032: The output_required_files command should not be called.
- CMP0031: The load_command command should not be called.
- CMP0030: The use_mangled_mesa command should not be called.
- CMP0029: The subdir_depends command should not be called.
- CMP0028: Double colon in target name means ALIAS or IMPORTED target.
- CMP0027: Conditionally linked imported targets with missing include directories.
- CMP0026: Disallow use of the LOCATION target property.
- CMP0025: Compiler id for Apple Clang is now AppleClang.
- CMP0024: Disallow include export result.
- CMP0023: Plain and keyword target_link_libraries signatures cannot be mixed.
- CMP0022: INTERFACE_LINK_LIBRARIES defines the link interface.
- CMP0021: Fatal error on relative paths in INCLUDE_DIRECTORIES target property.
- CMP0020: Automatically link Qt executables to qtmain target on Windows.
- CMP0019: Do not re-expand variables in include and link information.
- CMP0018: Ignore CMAKE_SHARED_LIBRARY_Lang_FLAGS variable.
- CMP0017: Prefer files from the CMake module directory when including from there.
- CMP0016: target_link_libraries() reports error if its only argument is not a target.
- CMP0015: link_directories() treats paths relative to the source dir.
- CMP0014: Input directories must have CMakeLists.txt.
- CMP0013: Duplicate binary directories are not allowed.
- CMP0012: if() recognizes numbers and boolean constants.
- CMP0011: Included scripts do automatic cmake_policy PUSH and POP.
- CMP0010: Bad variable reference syntax is an error.
- CMP0009: FILE GLOB_RECURSE calls should not follow symlinks by default.
- CMP0008: Libraries linked by full-path must have a valid library file name.
- CMP0007: list command no longer ignores empty elements.
- CMP0006: Installing MACOSX_BUNDLE targets requires a BUNDLE DESTINATION.
- CMP0005: Preprocessor definition values are now escaped automatically.
- CMP0004: Libraries linked may not have leading or trailing whitespace.
- CMP0003: Libraries linked via full path no longer produce linker search paths.
- CMP0002: Logical target names must be globally unique.
- CMP0001: CMAKE_BACKWARDS_COMPATIBILITY should no longer be used.
- CMP0000: A minimum required CMake version must be specified.