https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80498
--- Comment #6 from jonne <gcc at zutt dot org> --- I installed gdb with homebrew. I think it was compiled with debugging symbols, because of: $ otool -Iv /usr/local/opt/gdb/bin/gdb | head -5 /usr/local/opt/gdb/bin/gdb: Indirect symbols for (__TEXT,__stubs) 452 entries address index name 0x00000001002d05e6 15149 _iconv 0x00000001002d05ec 15150 _iconv_close $ dsymutil -s /usr/local/opt/gdb/bin/gdb | head ---------------------------------------------------------------------- Symbol table for: '/usr/local/opt/gdb/bin/gdb' (x86_64) ---------------------------------------------------------------------- Index n_strx n_type n_sect n_desc n_value ======== -------- ------------------ ------ ------ ---------------- [ 0] 00038668 0e ( SECT ) 01 0000 0000000100003365 '__ZL22amd64_get_insn_detailsPhP10amd64_insn' [ 1] 00038694 0e ( SECT ) 01 0000 000000010000371f '__ZL11amd64_ret_pPK10amd64_insn' [ 2] 000386b4 0e ( SECT ) 01 0000 000000010000374d '__ZL12amd64_call_pPK10amd64_insn' [ 3] 000386d5 0e ( SECT ) 01 0000 000000010000378a '__ZL21amd64_supply_fpregsetPK6regsetP8regcacheiPKvm' [ 4] 00038709 0e ( SECT ) 01 0000 00000001000037fd '__ZL22amd64_collect_fpregsetPK6regsetPK8regcacheiPvm' (gdb) bt #0 0x00007fffc8342bc9 in ?? () #1 0x00007fff5fbfd540 in ?? () #2 0x0000000100479300 in ?? () #3 0x00007fff5fbfc4f0 in ?? () #4 0x000000010016b551 in ?? () #5 0x00007fff00000000 in ?? () #6 0x0000000100000001 in ?? () #7 0x00007fff5fbfc560 in ?? () #8 0x000000005fbfc550 in ?? () #9 0x0000000100076970 in std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > std::__cxx11::regex_traits<char>::lookup_collatename<char const*>(char const*, char const*) const::__collatenames () #10 0x00000001015ae000 in ?? () #11 0x00007fff5fbfc4e0 in ?? () #12 0x000000000000000c in ?? () #13 0x0000000100478e9b in ?? () #14 0x0000000100046fbb in _GLOBAL__sub_I_00099_1_m.cpp () Backtrace stopped: previous frame inner to this frame (corrupt stack?) (gdb) frame 9 #9 0x0000000100076970 in std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > std::__cxx11::regex_traits<char>::lookup_collatename<char const*>(char const*, char const*) const::__collatenames () (gdb) display/i $pc1: x/i $pc A syntax error in expression, near `: x/i $pc'. (gdb) display/i $pc1 2: x/i $pc1 <error: Value can't be converted to integer.> (gdb) x/i $pc => 0x100076970 <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1680>: adc %ah,(%rdx) (gdb) frame 8 #8 0x000000005fbfc550 in ?? () (gdb) display/i $pc1 3: x/i $pc1 <error: Value can't be converted to integer.> (gdb) display/i $pc 4: x/i $pc => 0x5fbfc550: <error: Cannot access memory at address 0x5fbfc550> (gdb) x/i $pc1 Value can't be converted to integer. (gdb) x/i $pc => 0x5fbfc550: Cannot access memory at address 0x5fbfc550 Here's a fragment shown by 'layout asm' after 'frame 9' >│0x100076970 <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1680> adc %ah,(%rdx) │ │0x100076972 <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1682> add $0x100,%eax │ │0x100076977 <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1687> add %cl,0x0(%rdx) │ │0x10007697a <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1690> add %al,(%rax) │ │0x10007697c <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1692> sbb %eax,(%rax) │ │0x10007697e <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1694> add %al,(%rax) │ │0x100076980 <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1696> push %rax │ │0x100076981 <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1697> and 0x100(%rip),%al # 0x100076a87 <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collaten│ │0x100076987 <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1703> add %cl,0x0(%rdi) │ │0x10007698a <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1706> add %al,(%rax) │ │0x10007698c <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1708> and (%rax),%eax │ │0x10007698e <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1710> add %al,(%rax) │ │0x100076990 <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1712> add %al,(%rax) │ │0x100076992 <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1714> add %al,(%rax) │ │0x100076994 <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1716> add %al,(%rax) │ │0x100076996 <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1718> add %al,(%rax) │ │0x100076998 <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1720> add %al,(%rax) │ │0x10007699a <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1722> add %al,(%rax) │ │0x10007699c <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1724> add %al,(%rax) │ │0x10007699e <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1726> add %al,(%rax) │ │0x1000769a0 <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_stringIcSt11char_traitsIcESaIcEEET_SA_E14__collatenames+1728> loopne 0x10007694c <_ZZNKSt7__cxx1112regex_traitsIcE18lookup_collatenameIPKcEENS_12basic_strin│ Seems like frames 5 and 8 cannot be read: (gdb) frame 0 #0 0x00007fffc8342bc9 in ?? () (gdb) frame 1 #1 0x00007fff5fbfd540 in ?? () (gdb) up #2 0x0000000100479300 in ?? () (gdb) up #3 0x00007fff5fbfc4f0 in ?? () (gdb) up #4 0x000000010016b551 in ?? () (gdb) up #5 0x00007fff00000000 in ?? () Cannot access memory at address 0x7fff00000000 (gdb) up #6 0x0000000100000001 in ?? () (gdb) up #7 0x00007fff5fbfc560 in ?? () (gdb) up #8 0x000000005fbfc550 in ?? () Cannot access memory at address 0x5fbfc550 (gdb) up #9 0x0000000100076970 in std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > std::__cxx11::regex_traits<char>::lookup_collatename<char const*>(char const*, char const*) const::__collatenames () Sorry, I'm not sure what I can show you exactly.