[LLDB][MIPS] Make register read/write to set/get the size of register according to abi.

[slthakur]

Summary

For O32 abi register size should be 4 bytes.
For N32 and N64 abi register size should be 8 bytes.
This patch will make register read/write to set/get the size of register according to abi.

[tberghammer]

Looks good

source/Plugins/Process/Linux/NativeRegisterContextLinux_mips64.cpp

1391

(nit): I would prefer to use the following syntax, but don't feel strongly about it:

(arch.GetFlags() & lldb_private::ArchSpec::eMIPSABI_O32) ? 4 : 8

[slthakur]

Committed in revision 256834

source/Plugins/Process/Linux/NativeRegisterContextLinux_mips64.cpp

NativeRegisterContextLinux_mips64::DoReadRegisterValue(uint32_t offset,
 
     // Clear all bits in RegisterValue before writing actual value read from ptrace to avoid garbage value in 32-bit MSB 
     value.SetBytes((void *)(((unsigned char *)&regs) + offset), 8, GetByteOrder());
     Error error = NativeProcessLinux::PtraceWrapper(PTRACE_GETREGS, m_thread.GetID(), NULL, &regs, sizeof regs);
     if (error.Success())
     {
         lldb_private::ArchSpec arch;
         if (m_thread.GetProcess()->GetArchitecture(arch))
-            value.SetBytes((void *)(((unsigned char *)&regs) + offset + 4 * (arch.GetMachine() == llvm::Triple::mips)), arch.GetAddressByteSize(), arch.GetByteOrder());
+            value.SetBytes((void *)(((unsigned char *)&regs) + offset + 4 * (arch.GetMachine() == llvm::Triple::mips)), 4 + (!(arch.GetFlags() & lldb_private::ArchSpec::eMIPSABI_O32) * 4), arch.GetByteOrder());
         else
             error.SetErrorString("failed to get architecture");
     }
     return error;
 }
 
 Error
 NativeRegisterContextLinux_mips64::DoWriteRegisterValue(uint32_t offset,
                                                         const char* reg_name,
                                                         const RegisterValue &value)
 {
     GPR_linux_mips regs;
     Error error = NativeProcessLinux::PtraceWrapper(PTRACE_GETREGS, m_thread.GetID(), NULL, &regs, sizeof regs);
     if (error.Success())
     {
-        ::memcpy((void *)(((unsigned char *)(&regs)) + offset), value.GetBytes(), 8);
+        lldb_private::ArchSpec arch;
+        if (m_thread.GetProcess()->GetArchitecture(arch))
+        {
+            ::memcpy((void *)(((unsigned char *)(&regs)) + offset), value.GetBytes(), 4 + (!(arch.GetFlags() & lldb_private::ArchSpec::eMIPSABI_O32) * 4));
             error = NativeProcessLinux::PtraceWrapper(PTRACE_SETREGS, m_thread.GetID(), NULL, &regs, sizeof regs);
         }
+        else
+            error.SetErrorString("failed to get architecture");
+    }
     return error;
 }
 
 Error
 NativeRegisterContextLinux_mips64::DoReadWatchPointRegisterValue(lldb::tid_t tid, void* watch_readback)
 {
     return NativeProcessLinux::PtraceWrapper( PTRACE_GET_WATCH_REGS, m_thread.GetID(), watch_readback);
 }
 
 Error
 NativeRegisterContextLinux_mips64::DoWriteWatchPointRegisterValue(lldb::tid_t tid, void* watch_reg_value)
 {
     return NativeProcessLinux::PtraceWrapper(PTRACE_SET_WATCH_REGS, m_thread.GetID(), watch_reg_value);
 }
 
 #endif // defined (__mips__)