What's the gcc version to support build the llvm upstream?

hi, all:
when I update to the newest upstream, I find that the gcc 7.3.0 default on my system already can’t support to build it.

1、first I try to build with follwing flags, then it report error: /usr/bin/ld.gold: internal error in read_header_prolog, at …/…/gold/dwarf_reader.cc:1678

FLAGS = -Wall -fstack-protector-strong -fPIE -march=armv8-a -mlittle-endian -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Wall -Wextr       a -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-maybe-uninitialized -Wno-class-memaccess -Wn       o-noexcept-type -Wdelete-non-virtual-dtor -Wno-comment -Wmisleading-indentation -fdiagnostics-color -g    -fno-exceptions -fno-rtti -gsplit-dwarf -std=c++14

so I try to add option -gdwarf-2 according 27246 – ld.gold does not support DWARF5

2、then I rebuild the llvm , it come out a new fail:
include/c++/v1/__iterator/advance.h:63: error: undefined reference to ‘std::__1::__libcpp_assertion_handler(char const*, int, char const*, char const*)’

so I think we may alreay give up use the gcc 7.3 to build the llvm ?

7.3 should be supported for LLVM and Clang etc. but libc++ has higher requirements and the recommended build is to use runtime configuration for libc++.

See Building libc++ — libc++ 15.0.0git documentation

thanks very much, I tried to use libstdc++ instead, and it pass with gcc7.3