[MacPorts] #54068: mozjs17 @17.0.0_5 won't build (on PPC Tiger, Mac OS X 10.4.11) because sys/sysctl.h does not provide _SC_NPROCESSORS_ONLN but HW_NCPU

[MacPorts]

#54068: mozjs17  @17.0.0_5 won't build (on PPC Tiger, Mac OS X 10.4.11) because
sys/sysctl.h does not provide _SC_NPROCESSORS_ONLN but HW_NCPU
------------------------+-------------------
  Reporter:  ballapete  |      Owner:
      Type:  defect     |     Status:  new
  Priority:  Normal     |  Milestone:
 Component:  ports      |    Version:  2.4.1
Resolution:             |   Keywords:
      Port:  mozjs17    |
------------------------+-------------------

Comment (by ballapete):

 Replying to [comment:3 kencu]:
 > Good work .. see also
 > <https://github.com/macports/macports-
 ports/commit/4678a5ef46617d3d8ba1ab4f82c7fe1182f9f9df>

 OK! So your recommendation is to first include `AvailabilityMacros.h` (or
 `Availability.h`) in order to have a means to determine the macOS or Mac
 OS X version which is independently defined of the C compiler used?
 (Because some C compilers might not define that macro?) Of course a
 "globally" valid patch should start with `#ifdef __APPLE__`.

 So a good patch should look like this?

 {{{
 #ifdef __APPLE__                                                        #
 this block only for Macs
 # ifndef __MAC_OS_X_VERSION_MIN_REQUIRED                                #
 are AvailabilityMacros.h or Availability.h not yet included?
 #  if __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >= 1050             #
 then for Leopard and later…
 #   include <Availability.h>                                            #
 …either include this…
 #  else
 #   include <AvailabilityMacros.h>                                      #
 …or include that
 #  endif
 # endif
 # if __MAC_OS_X_VERSION_MIN_REQUIRED < 1050                             #
 and for some OS versions do this…

 /* whatever */

 # else                                                                  #
 …for others do that

 /* whatever else*/

 # endif                                                                 #
 finish OS version discrimination
 #endif                                                                  #
 finish Apple case
 }}}

 It would mean some effort if someone else would need to perform the
 quality control *I* put into my work…

--
Ticket URL: <https://trac.macports.org/ticket/54068#comment:4>
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