Thank you for your informations! However, there are still many bug in gcc-6.4.0 installation(see attachment below). It seems something complicated, but it's necessary for the installation of some soft. Is there a solution for all the bugs, like a bug-fixed 6.4.0 version? I need to install a old version gcc(<7.0). Thank you! Regards! Jianhao = = = = = = = = = = = = = = = attached message: /home/rx/program/gcc-6.4.0/x86_64-pc-linux-gnu/libssp/../.././libssp/gets-chk.c:74: warning: the `gets' function is dangerous and should not be used. ../../.././libsanitizer/sanitizer_common/sanitizer_posix.cc: In function ‘__sanitizer::fd_t __sanitizer::OpenFile(const char*, __sanitizer::FileAccessMode, __sanitizer::error_t*)’: ../../.././libsanitizer/sanitizer_common/sanitizer_posix.cc:179:27: warning: ‘flags’ may be used uninitialized in this function [-Wmaybe-uninitialized] fd_t res = internal_open(filename, flags, 0660); ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~ In file included from ../../.././libsanitizer/asan/asan_interceptors.cc:196:0: ../../.././libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc: In function ‘__sanitizer::uptr __interceptor_ptrace(int, int, void*, void*)’: ../../.././libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:2449:21: warning: ‘local_iovec.__sanitizer::__sanitizer_iovec::iov_len’ may be used uninitialized in this function [-Wmaybe-uninitialized] __sanitizer_iovec local_iovec; ^~~~~~~~~~~ ../../.././libsanitizer/asan/asan_interceptors.cc:56:34: warning: ‘local_iovec.__sanitizer::__sanitizer_iovec::iov_base’ may be used uninitialized in this function [-Wmaybe-uninitialized] uptr __offset = (uptr)(offset); \ ^ In file included from ../../.././libsanitizer/asan/asan_interceptors.cc:196:0: ../../.././libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:2449:21: note: ‘local_iovec.__sanitizer::__sanitizer_iovec::iov_base’ was declared here __sanitizer_iovec local_iovec; ^~~~~~~~~~~ In file included from ../../.././libsanitizer/tsan/tsan_interceptors.cc:2338:0: ../../.././libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc: In function ‘__sanitizer::uptr __interceptor_ptrace(int, int, void*, void*)’: ../../.././libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:2498:58: warning: ‘local_iovec.__sanitizer::__sanitizer_iovec::iov_len’ may be used uninitialized in this function [-Wmaybe-uninitialized] local_iovec.iov_len); ^ ../../.././libsanitizer/tsan/tsan_interceptors.cc:2240:20: warning: ‘local_iovec.__sanitizer::__sanitizer_iovec::iov_base’ may be used uninitialized in this function [-Wmaybe-uninitialized] MemoryAccessRange(((TsanInterceptorContext *)ctx)->thr, \ ^ In file included from ../../.././libsanitizer/tsan/tsan_interceptors.cc:2338:0: ../../.././libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:2449:21: note: ‘local_iovec.__sanitizer::__sanitizer_iovec::iov_base’ was declared here __sanitizer_iovec local_iovec; ^~~~~~~~~~~ Jonathan Wakely <jwakely.gcc@xxxxxxxxx> 于2018年9月26日周三 下午4:58写道: > On Wed, 26 Sep 2018 at 02:07, C.J. wrote: > > > > Dear specialists, > > > > I tried to install gcc6.4.0 in Fedora28, while something wrong happened > as > > following. > > > > In file included from ../.././libgcc/unwind-dw2.c:401:0: > > ./md-unwind-support.h: In function ‘x86_64_fallback_frame_state’: > > ./md-unwind-support.h:65:47: error: dereferencing pointer to > incomplete > > type ‘struct ucontex_t’ > > Are you sure the error says "ucontex_t"? That's not a valid type. It > should be either "struct ucontext" or ucontext_t. Not "struct > ucontex_t". > > Assuming it really says "struct ucontext" the fix you need is: > > https://gcc.gnu.org/viewcvs/gcc/trunk/libgcc/config/i386/linux-unwind.h?r1=249731&r2=249730&pathrev=249731 > -- Best regards! C.J.