libgcc9/gcc9: build fails with clang-9.0 during build of gencondmd: Undefined symbols for architecture x86_64: "ix86_binary_operator_ok(rtx_code, machine_mode, rtx_def**)"

[kencu (Ken)]

During the build of gcc9 with clang-9.0, the build fails with the error(s) as above.

Building gcc9 with clang-8.0 succeeds, but there are many warnings at the same point in the build.

Obviously will need to be reported upstream, but in the meantime, building gcc9 with clang-9.0 is no bueno.

I don't know yet about gcc 8,7,6,5, or 4

[kencu (Ken)]

I discovered this on SnowLeopard, but the same build failure happens on Mojave with clang-9.0:

/opt/local/bin/clang++-mp-9.0 -arch x86_64 -std=gnu++98   -g  -DIN_GCC    -fno-strict-aliasing -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wno-format -Wmissing-format-attribute -Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -fno-common  -DHAVE_CONFIG_H  -DGENERATOR_FILE -fno-PIE -Wl,-no_pie -L/opt/local/lib -Wl,-headerpad_max_install_names -Wl,-syslibroot,/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk -no-pie -o build/gencondmd \
	    build/gencondmd.o ../build-x86_64-apple-darwin18/libiberty/libiberty.a
clang: warning: argument unused during compilation: '-no-pie' [-Wunused-command-line-argument]
Undefined symbols for architecture x86_64:
  "ix86_binary_operator_ok(rtx_code, machine_mode, rtx_def**)", referenced from:
      ___cxx_global_var_init.95 in gencondmd.o
... and more

[kencu (Ken)]

Upstream bug report <​https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92061>

[kencu (Ken)]

In e29edf4b96db25bb99c40d6092c6a6bf64b5fe2c/macports-ports (master):

libgcc9/gcc9, libgcc-devel, gcc10: harmonize blacklisting

these ports are very similar wrt blacklisting
they don't build properly with macports-clang < 3.8
they don't build at all with clang-9.0 at present

see: #59253
see: #58493