[MacPorts] #61418: Wrong minimum clang version when compiler.thread_local_storage is yes and compiler.cxx_standard is 2014

[MacPorts]

#61418: Wrong minimum clang version when compiler.thread_local_storage is yes and
compiler.cxx_standard is 2014
-------------------------+--------------------
  Reporter:  ryandesign  |      Owner:  (none)
      Type:  defect      |     Status:  new
  Priority:  Normal      |  Milestone:
 Component:  base        |    Version:  2.6.3
Resolution:              |   Keywords:
      Port:              |
-------------------------+--------------------

Comment (by chrstphrchvz):

 I encountered an instance of this issue: https://github.com/macports
 /macports-ports/pull/8761#issuecomment-708126427

 There may be more ports recently impacted by this, as I was cleaning up
 compiler blacklist usage that looked addressed by
 https://github.com/macports/macports-base/pull/161 even if
 `compiler.cxx_standard` was 2014 or later.

 Would the following work instead?
 {{{
             if {${compiler.cxx_standard} >= 2017} {
                 set min_value [max_version $min_value 902.0.39.1]
             } elseif {${compiler.cxx_standard} >= 2014} {
                 set min_value [max_version $min_value 602.0.49]
             } elseif {${compiler.cxx_standard} >= 2011} {
                 set min_value [max_version $min_value 500.2.75]
             }
             if {${compiler.cxx_standard} >= 2011 &&
 ${compiler.thread_local_storage}} {
                 # macOS has supported thread-local storage since Mac OS X
 Lion.
                 # So __thread (GNU extension) and _Thread_local (C11)
 could be used.
                 # However, the C++11 keyword was not supported until Xcode
 8
                 #
 (https://developer.apple.com/library/archive/releasenotes/DeveloperTools
 /RN-
 Xcode/Chapters/Introduction.html#//apple_ref/doc/uid/TP40001051-CH1-SW127)
                 #
 (https://developer.apple.com/videos/play/wwdc2016-405/?time=354).
                 set min_value [max_version $min_value 800.0.38]
             }
 }}}

-- 
Ticket URL: <https://trac.macports.org/ticket/61418#comment:1>
MacPorts <https://www.macports.org/>
Ports system for macOS