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@@ -21,7 +21,21 @@ for a policy, also avoiding the warning.
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The :command:`cmake_minimum_required` command does more than report an
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error if a too-old version of CMake is used to build a project. It
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also sets all policies introduced in that CMake version or earlier to
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-NEW behavior.
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+NEW behavior. To manage policies without increasing the minimum required
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+CMake version, the :command:`if(POLICY)` command may be used::
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+
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+ if(POLICY CMP0990)
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+ cmake_policy(SET CMP0990 NEW)
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+ endif()
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+
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+This has the effect of using the NEW behavior with newer CMake releases which
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+users may be using and not issuing a compatibility warning.
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+
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+The setting of a policy is confined in some cases to not propagate to the
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+parent scope. For example, if the files read by the :command:`include` command
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+or the :command:`find_package` command contain a use of :command:`cmake_policy`,
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+that policy setting will not affect the caller by default. Both commands accept
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+an optional ``NO_POLICY_SCOPE`` keyword to control this behavior.
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The :variable:`CMAKE_MINIMUM_REQUIRED_VERSION` variable may also be used
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to determine whether to report an error on use of deprecated macros or
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Stephen Kelly