[MacPorts] #70085: root6: use MacPorts llvm, if possible, and disable it completely on powerpc

[MacPorts]

#70085: root6: use MacPorts llvm, if possible, and disable it completely on powerpc
--------------------------+--------------------
 Reporter:  barracuda156  |      Owner:  (none)
     Type:  defect        |     Status:  new
 Priority:  Normal        |  Milestone:
Component:  ports         |    Version:  2.9.3
 Keywords:  powerpc       |       Port:  root6
--------------------------+--------------------
 Why does it need to build a bundled version of LLVM and why is it forced
 onto a user at all, given that it is not supported on some archs?

 To a little surprise, build fails:
 {{{
 make[2]: Entering directory
 `/opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_science_root6/root6/work/build'
 [ 27%] Linking CXX executable ../../../../bin/clang-tblgen
 cd
 /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_science_root6/root6/work/build/interpreter
 /llvm-project/llvm/tools/clang/utils/TableGen && /opt/local/bin/cmake -E
 cmake_link_script CMakeFiles/clang-tblgen.dir/link.txt --verbose=ON
 /opt/local/bin/g++-mp-13 -pipe -Os -DNDEBUG
 -isystem/opt/local/include/LegacySupport -I/opt/local/include
 -D_GLIBCXX_USE_CXX11_ABI=0 -std=c++17 -Wno-implicit-fallthrough -Wno-
 noexcept-type -m32 -pipe -W -Wshadow -Wall -Woverloaded-virtual -fsigned-
 char -fno-common -pthread  -fPIC -fno-semantic-interposition -fvisibility-
 inlines-hidden -Werror=date-time -w -fno-common -Woverloaded-virtual -fno-
 strict-aliasing -O3 -DNDEBUG -arch ppc -mmacosx-version-min=10.6
 -Wl,-search_paths_first -Wl,-headerpad_max_install_names -m64
 -Wl,-headerpad_max_install_names -L/opt/local/lib -lMacportsLegacySupport
 -Wl,-rpath,/opt/local/lib/libgcc -mmacosx-version-min=10.6
 -Wl,-dead_strip "CMakeFiles/obj.clang-tblgen.dir/ASTTableGen.cpp.o"
 "CMakeFiles/obj.clang-tblgen.dir/ClangASTNodesEmitter.cpp.o"
 "CMakeFiles/obj.clang-tblgen.dir/ClangASTPropertiesEmitter.cpp.o"
 "CMakeFiles/obj.clang-tblgen.dir/ClangAttrEmitter.cpp.o" "CMakeFiles/obj
 .clang-tblgen.dir/ClangCommentCommandInfoEmitter.cpp.o" "CMakeFiles/obj
 .clang-tblgen.dir/ClangCommentHTMLNamedCharacterReferenceEmitter.cpp.o"
 "CMakeFiles/obj.clang-tblgen.dir/ClangCommentHTMLTagsEmitter.cpp.o"
 "CMakeFiles/obj.clang-tblgen.dir/ClangDataCollectorsEmitter.cpp.o"
 "CMakeFiles/obj.clang-tblgen.dir/ClangDiagnosticsEmitter.cpp.o"
 "CMakeFiles/obj.clang-tblgen.dir/ClangOpcodesEmitter.cpp.o"
 "CMakeFiles/obj.clang-tblgen.dir/ClangOpenCLBuiltinEmitter.cpp.o"
 "CMakeFiles/obj.clang-tblgen.dir/ClangOptionDocEmitter.cpp.o"
 "CMakeFiles/obj.clang-tblgen.dir/ClangSACheckersEmitter.cpp.o"
 "CMakeFiles/obj.clang-tblgen.dir/ClangSyntaxEmitter.cpp.o" "CMakeFiles/obj
 .clang-tblgen.dir/ClangTypeNodesEmitter.cpp.o" "CMakeFiles/obj.clang-
 tblgen.dir/MveEmitter.cpp.o" "CMakeFiles/obj.clang-
 tblgen.dir/NeonEmitter.cpp.o" "CMakeFiles/obj.clang-
 tblgen.dir/RISCVVEmitter.cpp.o" "CMakeFiles/obj.clang-
 tblgen.dir/SveEmitter.cpp.o" "CMakeFiles/obj.clang-
 tblgen.dir/TableGen.cpp.o" -o ../../../../bin/clang-tblgen
 ../../../../lib/libLLVMSupport.a ../../../../lib/libLLVMTableGen.a
 ../../../../lib/libLLVMSupport.a -lm /opt/local/lib/libz.dylib
 /opt/local/lib/libcurses.dylib ../../../../lib/libLLVMDemangle.a
 -lemutls_w
 g++-mp-13: warning: '-m64' conflicts with '-arch ppc' ('-m64' ignored)
 ld: could not find entry point "start" (perhaps missing crt1.o)
 collect2: error: ld returned 1 exit status
 make[2]: *** [interpreter/llvm-project/llvm/bin/clang-tblgen] Error 1
 }}}

 Errors suggest that the very setup is wrong also.

-- 
Ticket URL: <https://trac.macports.org/ticket/70085>
MacPorts <https://www.macports.org/>
Ports system for macOS