[MacPorts] #67572: gperftools: arm: cmake arch check broken, causing build failures

[MacPorts]

#67572: gperftools: arm: cmake arch check broken, causing build failures
-------------------------+----------------------
  Reporter:  mascguy     |      Owner:  mascguy
      Type:  defect      |     Status:  assigned
  Priority:  Normal      |  Milestone:
 Component:  ports       |    Version:  2.8.1
Resolution:              |   Keywords:  arm
      Port:  gperftools  |
-------------------------+----------------------

Comment (by ryandesign):

 Looking at the config.h from @2.10_2 (using cmake) on an Apple Silicon
 Mac:

 {{{
 /* How to access the PC from a struct ucontext */
 #define PC_FROM_UCONTEXT
 }}}

 CMake is determining this with code in
 [https://github.com/gperftools/gperftools/blob/master/cmake/PCFromUContext.cmake
 cmake/PCFromUContext.cmake].

 Compared to config.h from @2.10_0 (using autotools) on the same Mac:

 {{{
 /* How to access the PC from a struct ucontext */
 #define PC_FROM_UCONTEXT uc_mcontext->__ss.__pc
 }}}

 Autotools is determining this with code in
 [https://github.com/gperftools/gperftools/blob/master/m4/pc_from_ucontext.m4
 m4/pc_from_ucontext.m4].

 Apple Silicon support
 [https://github.com/gperftools/gperftools/commit/151cbf5146cd5b359a4470860d1f7d8f6a843d62
 was added to m4/pc_from_ucontext.m4 3 years ago] but was never added to
 cmake/PCFromUContext.cmake.

-- 
Ticket URL: <https://trac.macports.org/ticket/67572#comment:10>
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