DwarfCfiAutomaton.h

/*
 * Copyright (c) 2008-2014, Pedigree Developers
 *
 * Please see the CONTRIB file in the root of the source tree for a full
 * list of contributors.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef DWARFCFIAUTOMATON_H
#define DWARFCFIAUTOMATON_H

#include "pedigree/kernel/debugger/DwarfState.h"
#include "pedigree/kernel/processor/types.h"

// These three are different - they have a delta/register number stored in the
// lower 6 bits.
#define DW_CFA_advance_loc 0x40
#define DW_CFA_offset 0x80
#define DW_CFA_restore 0xc0

#define DW_CFA_nop 0x00
#define DW_CFA_set_loc 0x01
#define DW_CFA_advance_loc1 0x02
#define DW_CFA_advance_loc2 0x03
#define DW_CFA_advance_loc4 0x04
#define DW_CFA_offset_extended 0x05
#define DW_CFA_restore_extended 0x06
#define DW_CFA_undefined 0x07
#define DW_CFA_same_value 0x08
#define DW_CFA_register 0x09
#define DW_CFA_remember_state 0x0a
#define DW_CFA_restore_state 0x0b
#define DW_CFA_def_cfa 0x0c
#define DW_CFA_def_cfa_register 0x0d
#define DW_CFA_def_cfa_offset 0x0e
#define DW_CFA_def_cfa_expression 0x0f
#define DW_CFA_expression 0x10
#define DW_CFA_offset_extended_sf 0x11
#define DW_CFA_def_cfa_sf 0x12
#define DW_CFA_def_cfa_offset_sf 0x13
#define DW_CFA_val_offset 0x14
#define DW_CFA_val_offset_sf 0x15
#define DW_CFA_val_expression 0x16
#define DW_CFA_lo_user 0x1c
#define DW_CFA_hi_user 0x3f
#define DW_CFA_GNU_args_size 0x2e  // GNU extension

class DwarfCfiAutomaton
{
  public:
    DwarfCfiAutomaton();
    ~DwarfCfiAutomaton();

    void initialise(
        const DwarfState &startingState, uintptr_t nCodeLocation,
        size_t nCodeLen, int32_t nCodeAlignmentFactor,
        int32_t nDataAlignmentFactor, uintptr_t nStartingPc);

    DwarfState *
    execute(uintptr_t nCodeLocation, size_t nCodeLen, uintptr_t nBreakAt);

  private:
    void executeInstruction(uintptr_t &nLocation, uintptr_t &nPc);

    DwarfState m_InitialState;

    DwarfState m_CurrentState;

    int32_t m_nCodeAlignmentFactor;

    int32_t m_nDataAlignmentFactor;

    uintptr_t m_nStartingPc;
};

#endif