[MacPorts] #42654: cmake: upgrade to 3.0.0

[MacPorts]

#42654: cmake: upgrade to 3.0.0
----------------------+-------------------
  Reporter:  mojca@…  |      Owner:  css@…
      Type:  update   |     Status:  new
  Priority:  Normal   |  Milestone:
 Component:  ports    |    Version:
Resolution:           |   Keywords:
      Port:  cmake    |
----------------------+-------------------

Comment (by mojca@…):

 One "issue" I'm seeing is the following:
 {{{
  CMake Warning (dev) at CMakeLists.txt:5 (PROJECT):
    Policy CMP0025 is not set: Compiler id for Apple Clang is now
 AppleClang.
    Run "cmake --help-policy CMP0025" for policy details.  Use the
 cmake_policy
    command to set the policy and suppress this warning.

    Converting C compiler id "AppleClang" to "Clang" for compatibility.
  This warning is for project developers.  Use -Wno-dev to suppress it.
 }}}
 From `${prefix}/share/cmake-3.0/Help/policy/CMP0025.rst`:

 {{{
 CMP0025
 -------

 Compiler id for Apple Clang is now AppleClang.

 CMake >= 3.0 recognize that Apple Clang is a different compiler
 than upstream Clang and that they have different version numbers.
 CMake now prefers to present this to projects by setting
 CMAKE_<LANG>_COMPILER_ID to "AppleClang" instead of "Clang".  However,
 existing projects may assume the compiler id for Apple Clang is just
 "Clang" as it was in CMake < 3.0.  Therefore this policy determines
 for Apple Clang which compiler id to report in
 CMAKE_<LANG>_COMPILER_ID after <LANG> is enabled by the project() or
 enable_language() command.

 The OLD behavior for this policy is to use compiler id "Clang".  The
 NEW behavior for this policy is to use compiler id "AppleClang".

 This policy was introduced in CMake version 3.0.  CMake version
 |release| warns when the policy is not set and uses OLD behavior.  Use
 the cmake_policy command to set it to OLD or NEW explicitly.
 }}}

 But this needs to be reported to individual projects upstream and it
 doesn't seem to cause any problems.

 So far I didn't experience any troubles using CMake 3.0.

-- 
Ticket URL: <https://trac.macports.org/ticket/42654#comment:10>
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