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

#ifndef lldb_UnwindMacOSXFrameBackchain_h_
#define lldb_UnwindMacOSXFrameBackchain_h_

// C Includes
// C++ Includes
#include <vector>

// Other libraries and framework includes
// Project includes
#include "lldb/lldb-private.h"
#include "lldb/Target/Unwind.h"

class UnwindMacOSXFrameBackchain : public lldb_private::Unwind
{
public: 
    UnwindMacOSXFrameBackchain (lldb_private::Thread &thread);

    ~UnwindMacOSXFrameBackchain() override = default;

protected:
    void
    DoClear() override
    {
        m_cursors.clear();
    }

    uint32_t
    DoGetFrameCount() override;

    bool
    DoGetFrameInfoAtIndex(uint32_t frame_idx,
                          lldb::addr_t& cfa,
                          lldb::addr_t& pc) override;
    
    lldb::RegisterContextSP
    DoCreateRegisterContextForFrame(lldb_private::StackFrame *frame) override;

    friend class RegisterContextMacOSXFrameBackchain;

    struct Cursor
    {
        lldb::addr_t pc;    // Program counter
        lldb::addr_t fp;    // Frame pointer for us with backchain
    };

private:
    std::vector<Cursor> m_cursors;

    size_t
    GetStackFrameData_i386 (const lldb_private::ExecutionContext &exe_ctx);

    size_t
    GetStackFrameData_x86_64 (const lldb_private::ExecutionContext &exe_ctx);

    //------------------------------------------------------------------
    // For UnwindMacOSXFrameBackchain only
    //------------------------------------------------------------------
    DISALLOW_COPY_AND_ASSIGN (UnwindMacOSXFrameBackchain);
};

#endif // lldb_UnwindMacOSXFrameBackchain_h_