[MIPS] Read/Write register for MIPS64

[slthakur]

Summary

Implementation of read/write for general purpose and special purpose registers for MIPS64.

[slthakur]

Increased code context.

[tberghammer]

Looks good with minor inline comment.

source/Plugins/Process/Linux/NativeRegisterContextLinux_mips64.h

81–83

Can you make this function private?

[clayborg]

lgtm

[slthakur]

Addressed review comment

source/Plugins/Process/Linux/NativeProcessLinux.cpp

#if defined (__arm64__) || defined (__aarch64__)
             {
                 lldb_private::ArchSpec arch;
                 if (monitor->GetArchitecture(arch))
                     m_value.SetBytes((void *)(((unsigned char *)(regs)) + m_offset), 8, arch.GetByteOrder());
                 else
                     m_error.SetErrorString("failed to get architecture");
             }
         }
+#elif defined (__mips__)
+        elf_gregset_t regs;
+        PTRACE(PTRACE_GETREGS, m_tid, NULL, &regs, sizeof regs, m_error);
+        if (m_error.Success())
+        {
+            lldb_private::ArchSpec arch;
+            if (monitor->GetArchitecture(arch))
+                m_value.SetBytes((void *)(((unsigned char *)(regs)) + m_offset), 8, arch.GetByteOrder());
+            else
+                m_error.SetErrorString("failed to get architecture");
+        }
 #else
         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_REGISTERS));
 
         lldb::addr_t data = static_cast<unsigned long>(PTRACE(PTRACE_PEEKUSER, m_tid, (void*)m_offset, nullptr, 0, m_error));
         if (m_error.Success())
             m_value = data;
 
         if (log)
#if defined (__arm64__) || defined (__aarch64__)
             ioVec.iov_len = sizeof regs;
             PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, sizeof regs, m_error);
             if (m_error.Success())
             {
                 ::memcpy((void *)(((unsigned char *)(&regs)) + m_offset), m_value.GetBytes(), 8);
                 PTRACE(PTRACE_SETREGSET, m_tid, &regset, &ioVec, sizeof regs, m_error);
             }
         }
+#elif defined (__mips__)
+        elf_gregset_t regs;
+        PTRACE(PTRACE_GETREGS, m_tid, NULL, &regs, sizeof regs, m_error);
+        if (m_error.Success())
+        {
+            ::memcpy((void *)(((unsigned char *)(&regs)) + m_offset), m_value.GetBytes(), 8);
+            PTRACE(PTRACE_SETREGS, m_tid, NULL, &regs, sizeof regs, m_error);
+        }
 #else
         void* buf;
         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_REGISTERS));
 
         buf = (void*) m_value.GetAsUInt64();
 
         if (log)
             log->Printf ("NativeProcessLinux::%s() reg %s: %p", __FUNCTION__, m_reg_name, buf);

source/Plugins/Process/Linux/NativeRegisterContextLinux_mips64.h

public:
             uint32_t concrete_frame_idx, RegisterInfoInterface *reg_info_interface_p);
 
         uint32_t
         GetRegisterSetCount () const override;
 
         const RegisterSet *
         GetRegisterSet (uint32_t set_index) const override;
 
+        lldb_private::Error
+        ReadRegisterRaw (uint32_t reg_index, RegisterValue &reg_value);
+
         Error
         ReadRegister (const RegisterInfo *reg_info, RegisterValue &reg_value) override;
 
         Error
         WriteRegister (const RegisterInfo *reg_info, const RegisterValue &reg_value) override;
 
         Error
         ReadAllRegisterValues (lldb::DataBufferSP &data_sp) override;
public:
         SetHardwareWatchpoint (lldb::addr_t addr, size_t size,
                 uint32_t watch_flags) override;
 
         lldb::addr_t
         GetWatchpointAddress (uint32_t wp_index) override;
 
         uint32_t
         NumSupportedHardwareWatchpoints () override;
+
+    private:
+
+        lldb_private::Error
+        WriteRegister(const uint32_t reg, const RegisterValue &value);
     };
 }
 
 #endif // #ifndef lldb_NativeRegisterContextLinux_mips64_h
 

source/Plugins/Process/Linux/NativeRegisterContextLinux_mips64.cpp

switch (GetRegisterInfoInterface ().GetTargetArchitecture ().GetMachine ())
             assert (false && "Unhandled target architecture.");
             return nullptr;
     }
 
     return nullptr;
 }
 
 lldb_private::Error
+NativeRegisterContextLinux_mips64::ReadRegisterRaw (uint32_t reg_index, RegisterValue &reg_value)
+{
+    Error error;
+
+    const RegisterInfo *const reg_info = GetRegisterInfoAtIndex (reg_index);
+    if (!reg_info)
+    {
+        error.SetErrorStringWithFormat ("register %" PRIu32 " not found", reg_index);
+        return error;
+    }
+
+    NativeProcessProtocolSP process_sp (m_thread.GetProcess ());
+    if (!process_sp)
+    {
+        error.SetErrorString ("NativeProcessProtocol is NULL");
+        return error;
+    }
+
+    NativeProcessLinux *const process_p = reinterpret_cast<NativeProcessLinux*> (process_sp.get ());
+    return process_p->ReadRegisterValue(m_thread.GetID(),
+                                        reg_info->byte_offset,
+                                        reg_info->name,
+                                        reg_info->byte_size,
+                                        reg_value);
+}
+
+lldb_private::Error
 NativeRegisterContextLinux_mips64::ReadRegister (const RegisterInfo *reg_info, RegisterValue &reg_value)
 {
     Error error;
-    error.SetErrorString ("MIPS TODO: NativeRegisterContextLinux_mips64::ReadRegister not implemented");
+
+    if (!reg_info)
+    {
+        error.SetErrorString ("reg_info NULL");
+        return error;
+    }
+
+    const uint32_t reg = reg_info->kinds[lldb::eRegisterKindLLDB];
+    if (reg == LLDB_INVALID_REGNUM)
+    {
+        // This is likely an internal register for lldb use only and should not be directly queried.
+        error.SetErrorStringWithFormat ("register \"%s\" is an internal-only lldb register, cannot read directly", reg_info->name);
+        return error;
+    }
+
+    error = ReadRegisterRaw(reg, reg_value);
+
+    if (error.Success ())
+    {
+        // If our return byte size was greater than the return value reg size, then
+        // use the type specified by reg_info rather than the uint64_t default
+        if (reg_value.GetByteSize() > reg_info->byte_size)
+            reg_value.SetType(reg_info);
+    }
+
     return error;
 }
 
 lldb_private::Error
-NativeRegisterContextLinux_mips64::WriteRegister (const RegisterInfo *reg_info, const RegisterValue &reg_value)
+NativeRegisterContextLinux_mips64::WriteRegister(const uint32_t reg,
+                                                 const RegisterValue &value)
 {
     Error error;
-    error.SetErrorString ("MIPS TODO: NativeRegisterContextLinux_mips64::WriteRegister not implemented");
+
+    uint32_t reg_to_write = reg;
+    RegisterValue value_to_write = value;
+
+    NativeProcessProtocolSP process_sp (m_thread.GetProcess ());
+    if (!process_sp)
+    {
+        error.SetErrorString ("NativeProcessProtocol is NULL");
+        return error;
+    }
+
+    const RegisterInfo *const register_to_write_info_p = GetRegisterInfoAtIndex (reg_to_write);
+    assert (register_to_write_info_p && "register to write does not have valid RegisterInfo");
+    if (!register_to_write_info_p)
+    {
+        error.SetErrorStringWithFormat ("NativeRegisterContextLinux_mips64::%s failed to get RegisterInfo for write register index %" PRIu32, __FUNCTION__, reg_to_write);
         return error;
     }
 
+    NativeProcessLinux *const process_p = reinterpret_cast<NativeProcessLinux*> (process_sp.get ());
+    return process_p->WriteRegisterValue(m_thread.GetID(),
+                                         register_to_write_info_p->byte_offset,
+                                         register_to_write_info_p->name,
+                                         value_to_write);
+}
+
+
+
+lldb_private::Error
+NativeRegisterContextLinux_mips64::WriteRegister (const RegisterInfo *reg_info, const RegisterValue &reg_value)
+{
+    assert (reg_info && "reg_info is null");
+
+    const uint32_t reg_index = reg_info->kinds[lldb::eRegisterKindLLDB];
+
+    if (reg_index == LLDB_INVALID_REGNUM)
+        return Error ("no lldb regnum for %s", reg_info && reg_info->name ? reg_info->name : "<unknown register>");
+
+    return WriteRegister(reg_index, reg_value);
+}
+
 lldb_private::Error
 NativeRegisterContextLinux_mips64::ReadAllRegisterValues (lldb::DataBufferSP &data_sp)
 {
     Error error;
     error.SetErrorString ("MIPS TODO: NativeRegisterContextLinux_mips64::ReadAllRegisterValues not implemented");
     return error;
 }