base on commit 54e02179b, the llvm will build fail with gcc7.3, the error:
2338 [914/3268] Building CXX object projects/openmp/libomptarget/DeviceRTL/CMakeFiles/omptarget.devicertl.dir/src/Configuration.cpp.o
2339 FAILED: projects/openmp/libomptarget/DeviceRTL/CMakeFiles/omptarget.devicertl.dir/src/Configuration.cpp.o
2340 /usr/bin/ccache /usr/bin/g++ -DOMPTARGET_DEBUG -D_DEBUG -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Iprojects/openmp/libomptarget/DeviceRTL -I/hom e/zhongyunde/llvm-project-init-dev12x/openmp/libomptarget/DeviceRTL -Iinclude -I/home/zhongyunde/llvm-project-init-dev12x/llvm/include -I/home/zhongyunde/llvm-project-init-dev12x/openmp/li bomptarget/DeviceRTL/include -I/home/zhongyunde/llvm-project-init-dev12x/openmp/libomptarget/DeviceRTL/../include -Wall -fstack-protector-strong -fPIE -march=armv8-a -mlittle-endian -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-lon g-long -Wimplicit-fallthrough -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-c omment -Wmisleading-indentation -fdiagnostics-color -Wall -Wcast-qual -Wimplicit-fallthrough -Wsign-compare -Wno-extra -Wno-pedantic -Wno-maybe-uninitialized -std=c++14 -g -gsplit-dwarf -fopenmp -fopenmp-cuda-mode -foffload-lto -fvisibility=hidden -mllvm -openmp-opt-disable -nogpulib -nostdinc -DSHARED_SCRATCHPAD_SIZE=512 --offload-arch=sm_35 --offload-arch=sm_37 --offloa d-arch=sm_50 --offload-arch=sm_52 --offload-arch=sm_53 --offload-arch=sm_60 --offload-arch=sm_61 --offload-arch=sm_62 --offload-arch=sm_70 --offload-arch=sm_72 --offload-arch=sm_75 --offlo ad-arch=sm_80 --offload-arch=sm_86 --offload-arch=gfx700 --offload-arch=gfx701 --offload-arch=gfx801 --offload-arch=gfx803 --offload-arch=gfx900 --offload-arch=gfx902 --offload-arch=gfx906 --offload-arch=gfx908 --offload-arch=gfx90a --offload-arch=gfx90c --offload-arch=gfx940 --offload-arch=gfx1010 --offload-arch=gfx1030 --offload-arch=gfx1031 --offload-arch=gfx1032 --offlo ad-arch=gfx1033 --offload-arch=gfx1034 --offload-arch=gfx1035 --offload-arch=gfx1036 -std=c++17 -MD -MT projects/openmp/libomptarget/DeviceRTL/CMakeFiles/omptarget.devicertl.dir/src/Config uration.cpp.o -MF projects/openmp/libomptarget/DeviceRTL/CMakeFiles/omptarget.devicertl.dir/src/Configuration.cpp.o.d -o projects/openmp/libomptarget/DeviceRTL/CMakeFiles/omptarget.devicer tl.dir/src/Configuration.cpp.o -c /home/zhongyunde/llvm-project-init-dev12x/openmp/libomptarget/DeviceRTL/src/Configuration.cpp
2341 g++: error: unrecognized command line option '-fopenmp-cuda-mode'
2342 g++: error: unrecognized command line option '-foffload-lto'; did you mean '-foffload-abi='?
2343 g++: error: unrecognized command line option '-mllvm'
2344 g++: error: unrecognized command line option '-nogpulib'
2345 g++: error: unrecognized command line option '--offload-arch=sm_35'
2346 g++: error: unrecognized command line option '--offload-arch=sm_37'
2347 g++: error: unrecognized command line option '--offload-arch=sm_50'
2348 g++: error: unrecognized command line option '--offload-arch=sm_52'
2349 g++: error: unrecognized command line option '--offload-arch=sm_53'
2350 g++: error: unrecognized command line option '--offload-arch=sm_60'; did you mean '--offload-abi=lp64'?
2351 g++: error: unrecognized command line option '--offload-arch=sm_61'; did you mean '--offload-abi=lp64'?
2352 g++: error: unrecognized command line option '--offload-arch=sm_62'
2353 g++: error: unrecognized command line option '--offload-arch=sm_70'
2354 g++: error: unrecognized command line option '--offload-arch=sm_72'
2355 g++: error: unrecognized command line option '--offload-arch=sm_75'
2356 g++: error: unrecognized command line option '--offload-arch=sm_80'
2357 g++: error: unrecognized command line option '--offload-arch=sm_86'
2358 g++: error: unrecognized command line option '--offload-arch=gfx700'
2359 g++: error: unrecognized command line option '--offload-arch=gfx701'