Bug ID 37485
Summary LLDB reads wrong registers on 64bit Windows
OS Windows NT
Component All Bugs
LLDB reads wrong registers on 64bit Windows because RegisterContextWindows_x64::GetRegisterInfoAtIndex returns wrong reference. I encountered broken backtrace when the program stopped at function which does not have prologue code, such as compiled with '-fomit-frame-pointer'. In this situation, CFA is equal to rsp but LLDB reads r9. I investigated the cause. RegisterContextWindows_x64::GetRegisterInfoAtIndex depends the order of lldb_XXX_x86_64 values, but RegisterIndex/g_register_infos/g_gpr_reg_indices does not follow order. In source/Plugins/Process/Utility/lldb-x86-register-enums.h The order of GPRs is rax, rbx, rcx, rdx, rdi, rsi, rbp, rsp, r8, ... In source/Plugins/Process/Windows/Common/x64/RegisterContextWindows_x64.cpp The order of GPRs is rax, rbx, rcx, rdx, rdi, rsi, r8, r9, r10, ... I am using is what I built by myself on MinGW.