[MacPorts] #54242: clang-3.8 build fails on 10.5 PPC due to fatal error: lipo: specifed architecture in libclang_rt.10.4.a does not match its cputype -- and workaround that allows build to succeed

[MacPorts]

#54242: clang-3.8 build fails on 10.5 PPC due to fatal error: lipo: specifed
architecture in libclang_rt.10.4.a does not match its cputype -- and
workaround that allows build to succeed
------------------------+----------------------
  Reporter:  kencu      |      Owner:  jeremyhu
      Type:  defect     |     Status:  assigned
  Priority:  Normal     |  Milestone:
 Component:  ports      |    Version:
Resolution:             |   Keywords:  powerpc
      Port:  clang-3.8  |
------------------------+----------------------

Comment (by kencu):

 The cmake logic in this file appears to contain the relevant code:

 {{{
 work/llvm-3.8.1.src/projects/compiler-rt/cmake/config-ix.cmake
 }}}
 and checks for the 10.4 RT arches like this:
 {{{

   # Figure out which arches to use for each OS
   darwin_get_toolchain_supported_archs(toolchain_arches)
   message(STATUS "Toolchain supported arches: ${toolchain_arches}")


  # Need to build a 10.4 compatible libclang_rt
     set(DARWIN_10.4_SYSROOT ${DARWIN_osx_SYSROOT})
     set(DARWIN_10.4_BUILTIN_MIN_VER 10.4)
     set(DARWIN_10.4_BUILTIN_MIN_VER_FLAG
         -mmacosx-version-min=${DARWIN_10.4_BUILTIN_MIN_VER})
     set(DARWIN_10.4_SKIP_CC_KEXT On)
     darwin_test_archs(10.4
       DARWIN_10.4_ARCHS
       ${toolchain_arches})
     message(STATUS "OSX 10.4 supported arches: ${DARWIN_10.4_ARCHS}")
     if(DARWIN_10.4_ARCHS)
       # don't include the Haswell slice in the 10.4 compatibility library
       list(REMOVE_ITEM DARWIN_10.4_ARCHS x86_64h)
       list(APPEND BUILTIN_SUPPORTED_OS 10.4)
     endif()
 }}}

 which calls darwin_get_toolchain_supported_archs which is in this file

 {{{
 work/llvm-3.8.1.src/projects/compiler-
 rt/cmake/Modules/CompilerRTDarwinUtils.cmake
 }}}

 {{{
 function(darwin_get_toolchain_supported_archs output_var)
   execute_process(
     COMMAND ld -v
     ERROR_VARIABLE LINKER_VERSION)

   string(REGEX MATCH "configured to support archs: ([^\n]+)"
          ARCHES_MATCHED "${LINKER_VERSION}")
   if(ARCHES_MATCHED)
     set(ARCHES "${CMAKE_MATCH_1}")
     message(STATUS "Got ld supported ARCHES: ${ARCHES}")
     string(REPLACE " " ";" ARCHES ${ARCHES})
   else()
     # If auto-detecting fails, fall back to a default set
     message(WARNING "Detecting supported architectures from 'ld -v'
 failed. Returning default set.")
     set(ARCHES "i386;x86_64;armv7;armv7s;arm64")
   endif()

   set(${output_var} ${ARCHES} PARENT_SCOPE)
 endfunction()
 }}}

 on 10.5 INTEL the `ld` test gives you proper archs:
 {{{
  ld -v
 @(#)PROGRAM:ld  PROJECT:ld64-127.2
 configured to support archs: i386 x86_64 ppc ppc64 armv6 armv7
 LTO support using: LLVM version 3.3
 }}}

 but on on 10.5 PPC you get this:
 {{{
 $ ld -v
 @(#)PROGRAM:ld  PROJECT:ld64-127.2
 LLVM version 3.3
 }}}

 so it goes to the defaults instead
 {{{

     set(ARCHES "i386;x86_64;armv7;armv7s;arm64")
 }}}
 which are wrong for ppc. I generated a simple patch to allowed that test
 to return:
 {{{
     set(ARCHES "i386;x86_64;ppc;ppc64;armv7;armv7s;arm64")
 }}}
 and I had hoped that might solve this error, but as you can see from the
 configuration listing above, even though it now returns the proper ARCHES
 from the `ld` test, the error still occurs, so the incorrect arch setting
 must be elsewhere.

--
Ticket URL: <https://trac.macports.org/ticket/54242#comment:3>
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