//===-- RegisterContext.h ---------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef liblldb_RegisterContext_h_
#define liblldb_RegisterContext_h_

// C Includes
// C++ Includes
// Other libraries and framework includes
// Project includes
#include "lldb/lldb-private.h"
#include "lldb/Target/ExecutionContextScope.h"

namespace lldb_private {

class RegisterContext :
    public std::enable_shared_from_this<RegisterContext>,
    public ExecutionContextScope
{
public:
    //------------------------------------------------------------------
    // Constructors and Destructors
    //------------------------------------------------------------------
    RegisterContext (Thread &thread, uint32_t concrete_frame_idx);

    ~RegisterContext() override;

    void
    InvalidateIfNeeded (bool force);

    //------------------------------------------------------------------
    // Subclasses must override these functions
    //------------------------------------------------------------------
    virtual void
    InvalidateAllRegisters () = 0;

    virtual size_t
    GetRegisterCount () = 0;

    virtual const RegisterInfo *
    GetRegisterInfoAtIndex (size_t reg) = 0;

    virtual size_t
    GetRegisterSetCount () = 0;

    virtual const RegisterSet *
    GetRegisterSet (size_t reg_set) = 0;

    virtual bool
    ReadRegister (const RegisterInfo *reg_info, RegisterValue &reg_value) = 0;

    virtual bool
    WriteRegister (const RegisterInfo *reg_info, const RegisterValue &reg_value) = 0;
    
    virtual bool
    ReadAllRegisterValues (lldb::DataBufferSP &data_sp)
    {
        return false;
    }
    
    virtual bool
    WriteAllRegisterValues (const lldb::DataBufferSP &data_sp)
    {
        return false;
    }

    // These two functions are used to implement "push" and "pop" of register states.  They are used primarily
    // for expression evaluation, where we need to push a new state (storing the old one in data_sp) and then
    // restoring the original state by passing the data_sp we got from ReadAllRegisters to WriteAllRegisterValues.
    // ReadAllRegisters will do what is necessary to return a coherent set of register values for this thread, which
    // may mean e.g. interrupting a thread that is sitting in a kernel trap.  That is a somewhat disruptive operation,
    // so these API's should only be used when this behavior is needed.
    
    virtual bool
    ReadAllRegisterValues (lldb_private::RegisterCheckpoint &reg_checkpoint);
    
    virtual bool
    WriteAllRegisterValues (const lldb_private::RegisterCheckpoint &reg_checkpoint);
    
    bool
    CopyFromRegisterContext (lldb::RegisterContextSP context);

    //------------------------------------------------------------------
    /// Convert from a given register numbering scheme to the lldb register 
    /// numbering scheme
    ///
    /// There may be multiple ways to enumerate the registers for a given
    /// architecture.  ABI references will specify one to be used with
    /// DWARF, the register numberings from process plugin, there may
    /// be a variation used for eh_frame unwind instructions (e.g. on Darwin),
    /// and so on.  Register 5 by itself is meaningless - RegisterKind
    /// enumeration tells you what context that number should be translated as.
    ///
    /// Inside lldb, register numbers are in the eRegisterKindLLDB scheme;
    /// arguments which take a register number should take one in that
    /// scheme.
    ///
    /// eRegisterKindGeneric is a special numbering scheme which gives us 
    /// constant values for the pc, frame register, stack register, etc., for
    /// use within lldb.  They may not be defined for all architectures but
    /// it allows generic code to translate these common registers into the
    /// lldb numbering scheme.
    ///
    /// This method translates a given register kind + register number into
    /// the eRegisterKindLLDB register numbering.
    ///
    /// @param [in] kind
    ///     The register numbering scheme (RegisterKind) that the following
    ///     register number is in.
    ///
    /// @param [in] num
    ///     A register number in the 'kind' register numbering scheme.
    ///
    /// @return
    ///     The equivalent register number in the eRegisterKindLLDB
    ///     numbering scheme, if possible, else LLDB_INVALID_REGNUM.
    //------------------------------------------------------------------
    virtual uint32_t
    ConvertRegisterKindToRegisterNumber (lldb::RegisterKind kind, uint32_t num) = 0;

    //------------------------------------------------------------------
    // Subclasses can override these functions if desired
    //------------------------------------------------------------------
    virtual uint32_t
    NumSupportedHardwareBreakpoints ();

    virtual uint32_t
    SetHardwareBreakpoint (lldb::addr_t addr, size_t size);

    virtual bool
    ClearHardwareBreakpoint (uint32_t hw_idx);

    virtual uint32_t
    NumSupportedHardwareWatchpoints ();

    virtual uint32_t
    SetHardwareWatchpoint (lldb::addr_t addr, size_t size, bool read, bool write);

    virtual bool
    ClearHardwareWatchpoint (uint32_t hw_index);

    virtual bool
    HardwareSingleStep (bool enable);
    
    virtual Error
    ReadRegisterValueFromMemory (const lldb_private::RegisterInfo *reg_info, lldb::addr_t src_addr, uint32_t src_len, RegisterValue &reg_value);

    virtual Error
    WriteRegisterValueToMemory (const lldb_private::RegisterInfo *reg_info, lldb::addr_t dst_addr, uint32_t dst_len, const RegisterValue &reg_value);

    //------------------------------------------------------------------
    // Subclasses should not override these
    //------------------------------------------------------------------
    virtual lldb::tid_t
    GetThreadID() const;

    virtual Thread &
    GetThread ()
    {
        return m_thread;
    }

    const RegisterInfo *
    GetRegisterInfoByName (const char *reg_name, uint32_t start_idx = 0);

    const RegisterInfo *
    GetRegisterInfo (lldb::RegisterKind reg_kind, uint32_t reg_num);

    uint64_t
    GetPC (uint64_t fail_value = LLDB_INVALID_ADDRESS);

    bool
    SetPC (uint64_t pc);

    bool SetPC (Address addr);

    uint64_t
    GetSP (uint64_t fail_value = LLDB_INVALID_ADDRESS);

    bool
    SetSP (uint64_t sp);

    uint64_t
    GetFP (uint64_t fail_value = LLDB_INVALID_ADDRESS);

    bool
    SetFP (uint64_t fp);

    const char *
    GetRegisterName (uint32_t reg);

    uint64_t
    GetReturnAddress (uint64_t fail_value = LLDB_INVALID_ADDRESS);

    uint64_t
    GetFlags (uint64_t fail_value = 0);

    uint64_t
    ReadRegisterAsUnsigned (uint32_t reg, uint64_t fail_value);

    uint64_t
    ReadRegisterAsUnsigned (const RegisterInfo *reg_info, uint64_t fail_value);
    
    bool
    WriteRegisterFromUnsigned (uint32_t reg, uint64_t uval);

    bool
    WriteRegisterFromUnsigned (const RegisterInfo *reg_info, uint64_t uval);

    bool
    ConvertBetweenRegisterKinds (lldb::RegisterKind source_rk, uint32_t source_regnum, lldb::RegisterKind target_rk, uint32_t& target_regnum);

    //------------------------------------------------------------------
    // lldb::ExecutionContextScope pure virtual functions
    //------------------------------------------------------------------
    lldb::TargetSP
    CalculateTarget() override;
    
    lldb::ProcessSP
    CalculateProcess() override;
    
    lldb::ThreadSP
    CalculateThread() override;
    
    lldb::StackFrameSP
    CalculateStackFrame() override;

    void
    CalculateExecutionContext(ExecutionContext &exe_ctx) override;

    uint32_t
    GetStopID () const
    {
        return m_stop_id;
    }

    void
    SetStopID (uint32_t stop_id)
    {
        m_stop_id = stop_id;
    }

protected:
    //------------------------------------------------------------------
    // Classes that inherit from RegisterContext can see and modify these
    //------------------------------------------------------------------
    Thread &m_thread;               // The thread that this register context belongs to.
    uint32_t m_concrete_frame_idx;    // The concrete frame index for this register context
    uint32_t m_stop_id;             // The stop ID that any data in this context is valid for
private:
    //------------------------------------------------------------------
    // For RegisterContext only
    //------------------------------------------------------------------
    DISALLOW_COPY_AND_ASSIGN (RegisterContext);
};

} // namespace lldb_private

#endif // liblldb_RegisterContext_h_
