/*
 * See the dyninst/COPYRIGHT file for copyright information.
 *
 * We provide the Paradyn Tools (below described as "Paradyn")
 * on an AS IS basis, and do not warrant its validity or performance.
 * We reserve the right to update, modify, or discontinue this
 * software at any time.  We shall have no obligation to supply such
 * updates or modifications or any other form of support to you.
 *
 * By your use of Paradyn, you understand and agree that we (or any
 * other person or entity with proprietary rights in Paradyn) are
 * under no obligation to provide either maintenance services,
 * update services, notices of latent defects, or correction of
 * defects for Paradyn.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "h/dyninstAPI_RT.h"
#include "src/RTcommon.h"
#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>

#if defined(__GNUC__)
#    include <unistd.h>
#    define FAST_CALL __attribute__((fastcall))
#elif defined(os_windows)
#    define FAST_CALL __fastcall
#endif

/* Code to assist in remapping memory operations that were affected
 * by our instrumentation */

extern void
DYNINST_stopThread(void*, void*, void*, void*);

#if _MSC_VER
struct MemoryMapper RTmemoryMapper = { 0, 0, 0, 0 };
#else
struct MemoryMapper RTmemoryMapper = { 0, 0, 0, 0, { { 0 } } };
#endif
extern FILE* stOut;

// #define DEBUG_MEM_EM

unsigned long
RTtranslateMemory(unsigned long input, unsigned long origAddr, unsigned long currAddr)
{
    /* Standard nonblocking synchronization construct */
    int          index;
    int          min;
    int          max;
    volatile int guard2;
    (void) origAddr; /* unused parameter */
    (void) currAddr; /* unused parameter */

    do
    {
        guard2 = RTmemoryMapper.guard2;
        min    = 0;
        max    = (RTmemoryMapper.size - 1);
        do
        {
            index = min + ((max - min) / 2);
            if(input >= RTmemoryMapper.elements[index].lo)
            {
                /* Either correct or too low */
                if(input < RTmemoryMapper.elements[index].hi)
                {
                    break;
                }
                else
                {
                    min = index + 1;
                }
            }
            else
            {
                /* Too high */
                max = index - 1;
            }
        } while(min <= max);
    } while(guard2 != RTmemoryMapper.guard1);

    if(min <= max)
    {
        if(RTmemoryMapper.elements[index].shift == -1)
        {
            return 0;
        }
        else
        {
            return input + RTmemoryMapper.elements[index].shift;
        }
    }
    else
    {
        return input;
    }
    return 0;
}

unsigned long
RTtranslateMemoryShift(unsigned long input, unsigned long origAddr,
                       unsigned long currAddr)
{
    /* Standard nonblocking synchronization construct */
    int          index;
    int          min;
    int          max;
    volatile int guard2;
    (void) origAddr; /* unused parameter */
    (void) currAddr; /* unused parameter */

    do
    {
        guard2 = RTmemoryMapper.guard2;
        min    = 0;
        max    = (RTmemoryMapper.size - 1);
        do
        {
            index = min + ((max - min) / 2);
            if(input >= RTmemoryMapper.elements[index].lo)
            {
                /* Either correct or too low */
                if(input < RTmemoryMapper.elements[index].hi)
                {
                    break;
                }
                else
                {
                    min = index + 1;
                }
            }
            else
            {
                /* Too high */
                max = index - 1;
            }
        } while(min <= max);
    } while(guard2 != RTmemoryMapper.guard1);

    if(min <= max)
    {
        if(RTmemoryMapper.elements[index].shift == -1)
        {
            fflush(stOut);
            return -1 * input;
        }
        else
        {
            return RTmemoryMapper.elements[index].shift;
        }
    }
    else
    {
        return 0;
    }
    return 0;
}

int RTuntranslatedEntryCounter;
extern void
DYNINST_stopThread(void* pointAddr, void* callBackID, void* flags, void* calculation);

void
RThandleShadow(void* direction, void* pointAddr, void* callbackID, void* flags,
               void* calculation)
{
    (void) calculation; /* unused parameter */
    if((int) ((long) direction) == 1)
    {
        if(RTuntranslatedEntryCounter == 0)
        {
            // Entering a system call...
            DYNINST_stopThread(pointAddr, callbackID, flags, (void*) 1);
        }
        RTuntranslatedEntryCounter++;
    }
    else
    {
        if(RTuntranslatedEntryCounter > 0)
        {
            RTuntranslatedEntryCounter--;
        }
        if(RTuntranslatedEntryCounter == 0)
        {
            DYNINST_stopThread(pointAddr, callbackID, flags, (void*) 0);
        }
    }
}