rarvm.cpp

我把unrar的代码整理成vc工程了

#include "rar.hpp"

#include "rarvmtbl.cpp"

RarVM::RarVM()
{
  Mem=NULL;
}


RarVM::~RarVM()
{
  delete[] Mem;
}


void RarVM::Init()
{
  if (Mem==NULL)
    Mem=new byte[VM_MEMSIZE+4];
}

/*********************************************************************
 IS_VM_MEM macro checks if address belongs to VM memory pool (Mem).
 Only Mem data are always low endian regardless of machine architecture,
 so we need to convert them to native format when reading or writing.
 VM registers have endianness of host machine.
**********************************************************************/
#define IS_VM_MEM(a) (((byte*)a)>=Mem && ((byte*)a)<Mem+VM_MEMSIZE)

inline uint RarVM::GetValue(bool ByteMode,uint *Addr)
{
  if (ByteMode)
  {
#ifdef BIG_ENDIAN
    if (IS_VM_MEM(Addr))
      return(*(byte *)Addr);
    else
      return(*Addr & 0xff);
#else
    return(*(byte *)Addr);
#endif
  }
  else
  {
#if defined(BIG_ENDIAN) || !defined(ALLOW_NOT_ALIGNED_INT)
    if (IS_VM_MEM(Addr))
    {
      byte *B=(byte *)Addr;
      return UINT32((uint)B[0]|((uint)B[1]<<8)|((uint)B[2]<<16)|((uint)B[3]<<24));
    }
    else
      return UINT32(*Addr);
#else
    return UINT32(*Addr);
#endif
  }
}

#if defined(BIG_ENDIAN) || !defined(ALLOW_NOT_ALIGNED_INT)
  #define GET_VALUE(ByteMode,Addr) GetValue(ByteMode,(uint *)Addr)
#else
  #define GET_VALUE(ByteMode,Addr) ((ByteMode) ? (*(byte *)(Addr)):UINT32(*(uint *)(Addr)))
#endif


inline void RarVM::SetValue(bool ByteMode,uint *Addr,uint Value)
{
  if (ByteMode)
  {
#ifdef BIG_ENDIAN
    if (IS_VM_MEM(Addr))
      *(byte *)Addr=Value;
    else
      *Addr=(*Addr & ~0xff)|(Value & 0xff);
#else
    *(byte *)Addr=Value;
#endif
  }
  else
  {
#if defined(BIG_ENDIAN) || !defined(ALLOW_NOT_ALIGNED_INT) || !defined(PRESENT_INT32)
    if (IS_VM_MEM(Addr))
    {
      ((byte *)Addr)[0]=(byte)Value;
      ((byte *)Addr)[1]=(byte)(Value>>8);
      ((byte *)Addr)[2]=(byte)(Value>>16);
      ((byte *)Addr)[3]=(byte)(Value>>24);
    }
    else
      *(uint *)Addr=Value;
#else
    *(uint32 *)Addr=Value;
#endif
  }
}

#if defined(BIG_ENDIAN) || !defined(ALLOW_NOT_ALIGNED_INT) || !defined(PRESENT_INT32)
  #define SET_VALUE(ByteMode,Addr,Value) SetValue(ByteMode,(uint *)Addr,Value)
#else
  #define SET_VALUE(ByteMode,Addr,Value) ((ByteMode) ? (*(byte *)(Addr)=(Value)):(*(uint32 *)(Addr)=((uint32)(Value))))
#endif


void RarVM::SetLowEndianValue(uint *Addr,uint Value)
{
#if defined(BIG_ENDIAN) || !defined(ALLOW_NOT_ALIGNED_INT) || !defined(PRESENT_INT32)
  ((byte *)Addr)[0]=(byte)Value;
  ((byte *)Addr)[1]=(byte)(Value>>8);
  ((byte *)Addr)[2]=(byte)(Value>>16);
  ((byte *)Addr)[3]=(byte)(Value>>24);
#else
  *(uint32 *)Addr=Value;
#endif
}


inline uint* RarVM::GetOperand(VM_PreparedOperand *CmdOp)
{
  if (CmdOp->Type==VM_OPREGMEM)
    return((uint *)&Mem[(*CmdOp->Addr+CmdOp->Base)&VM_MEMMASK]);
  else
    return(CmdOp->Addr);
}


void RarVM::Execute(VM_PreparedProgram *Prg)
{
  memcpy(R,Prg->InitR,sizeof(Prg->InitR));
  unsigned int GlobalSize=Min(Prg->GlobalData.Size(),VM_GLOBALMEMSIZE);
  if (GlobalSize)
    memcpy(Mem+VM_GLOBALMEMADDR,&Prg->GlobalData[0],GlobalSize);
  unsigned int StaticSize=Min(Prg->StaticData.Size(),VM_GLOBALMEMSIZE-GlobalSize);
  if (StaticSize)
    memcpy(Mem+VM_GLOBALMEMADDR+GlobalSize,&Prg->StaticData[0],StaticSize);

  R[7]=VM_MEMSIZE;
  Flags=0;

  VM_PreparedCommand *PreparedCode=Prg->AltCmd ? Prg->AltCmd:&Prg->Cmd[0];
  if (!ExecuteCode(PreparedCode,Prg->CmdCount))
    PreparedCode[0].OpCode=VM_RET;
  uint NewBlockPos=GET_VALUE(false,&Mem[VM_GLOBALMEMADDR+0x20])&VM_MEMMASK;
  uint NewBlockSize=GET_VALUE(false,&Mem[VM_GLOBALMEMADDR+0x1c])&VM_MEMMASK;
  if (NewBlockPos+NewBlockSize>=VM_MEMSIZE)
    NewBlockPos=NewBlockSize=0;
  Prg->FilteredData=Mem+NewBlockPos;
  Prg->FilteredDataSize=NewBlockSize;

  Prg->GlobalData.Reset();

  uint DataSize=Min(GET_VALUE(false,(uint*)&Mem[VM_GLOBALMEMADDR+0x30]),VM_GLOBALMEMSIZE-VM_FIXEDGLOBALSIZE);
  if (DataSize!=0)
  {
    Prg->GlobalData.Add(DataSize+VM_FIXEDGLOBALSIZE);
    memcpy(&Prg->GlobalData[0],&Mem[VM_GLOBALMEMADDR],DataSize+VM_FIXEDGLOBALSIZE);
  }
}


/*
Note:
  Due to performance considerations RAR VM may set VM_FS, VM_FC, VM_FZ
  incorrectly for byte operands. These flags are always valid only
  for 32-bit operands. Check implementation of concrete VM command
  to see if it sets flags right.
*/

#define SET_IP(IP)                      \
  if ((IP)>=CodeSize)                   \
    return(true);                       \
  if (--MaxOpCount<=0)                  \
    return(false);                      \
  Cmd=PreparedCode+(IP);

bool RarVM::ExecuteCode(VM_PreparedCommand *PreparedCode,int CodeSize)
{
  int MaxOpCount=25000000;
  VM_PreparedCommand *Cmd=PreparedCode;
  while (1)
  {
#ifndef NORARVM
    // Get addresses to quickly access operands.
    uint *Op1=GetOperand(&Cmd->Op1);
    uint *Op2=GetOperand(&Cmd->Op2);
#endif
    switch(Cmd->OpCode)
    {
#ifndef NORARVM
      case VM_MOV:
        SET_VALUE(Cmd->ByteMode,Op1,GET_VALUE(Cmd->ByteMode,Op2));
        break;
#ifdef VM_OPTIMIZE
      case VM_MOVB:
        SET_VALUE(true,Op1,GET_VALUE(true,Op2));
        break;
      case VM_MOVD:
        SET_VALUE(false,Op1,GET_VALUE(false,Op2));
        break;
#endif
      case VM_CMP:
        {
          uint Value1=GET_VALUE(Cmd->ByteMode,Op1);
          uint Result=UINT32(Value1-GET_VALUE(Cmd->ByteMode,Op2));
          Flags=Result==0 ? VM_FZ:(Result>Value1)|(Result&VM_FS);
        }
        break;
#ifdef VM_OPTIMIZE
      case VM_CMPB:
        {
          uint Value1=GET_VALUE(true,Op1);
          uint Result=UINT32(Value1-GET_VALUE(true,Op2));
          Flags=Result==0 ? VM_FZ:(Result>Value1)|(Result&VM_FS);
        }
        break;
      case VM_CMPD:
        {
          uint Value1=GET_VALUE(false,Op1);
          uint Result=UINT32(Value1-GET_VALUE(false,Op2));
          Flags=Result==0 ? VM_FZ:(Result>Value1)|(Result&VM_FS);
        }
        break;
#endif
      case VM_ADD:
        {
          uint Value1=GET_VALUE(Cmd->ByteMode,Op1);
          uint Result=UINT32(Value1+GET_VALUE(Cmd->ByteMode,Op2));
          if (Cmd->ByteMode)
          {
            Result&=0xff;
            Flags=(Result<Value1)|(Result==0 ? VM_FZ:((Result&0x80) ? VM_FS:0));
          }
          else
            Flags=(Result<Value1)|(Result==0 ? VM_FZ:(Result&VM_FS));
          SET_VALUE(Cmd->ByteMode,Op1,Result);
        }
        break;
#ifdef VM_OPTIMIZE
      case VM_ADDB:
        SET_VALUE(true,Op1,GET_VALUE(true,Op1)+GET_VALUE(true,Op2));
        break;
      case VM_ADDD:
        SET_VALUE(false,Op1,GET_VALUE(false,Op1)+GET_VALUE(false,Op2));
        break;
#endif
      case VM_SUB:
        {
          uint Value1=GET_VALUE(Cmd->ByteMode,Op1);
          uint Result=UINT32(Value1-GET_VALUE(Cmd->ByteMode,Op2));
          Flags=Result==0 ? VM_FZ:(Result>Value1)|(Result&VM_FS);
          SET_VALUE(Cmd->ByteMode,Op1,Result);
        }
        break;
#ifdef VM_OPTIMIZE
      case VM_SUBB:
        SET_VALUE(true,Op1,GET_VALUE(true,Op1)-GET_VALUE(true,Op2));
        break;
      case VM_SUBD:
        SET_VALUE(false,Op1,GET_VALUE(false,Op1)-GET_VALUE(false,Op2));
        break;
#endif
      case VM_JZ:
        if ((Flags & VM_FZ)!=0)
        {
          SET_IP(GET_VALUE(false,Op1));
          continue;
        }
        break;
      case VM_JNZ:
        if ((Flags & VM_FZ)==0)
        {
          SET_IP(GET_VALUE(false,Op1));
          continue;
        }
        break;
      case VM_INC:
        {
          uint Result=UINT32(GET_VALUE(Cmd->ByteMode,Op1)+1);
          if (Cmd->ByteMode)
            Result&=0xff;
          SET_VALUE(Cmd->ByteMode,Op1,Result);
          Flags=Result==0 ? VM_FZ:Result&VM_FS;
        }
        break;
#ifdef VM_OPTIMIZE
      case VM_INCB:
        SET_VALUE(true,Op1,GET_VALUE(true,Op1)+1);
        break;
      case VM_INCD:
        SET_VALUE(false,Op1,GET_VALUE(false,Op1)+1);
        break;
#endif
      case VM_DEC:
        {
          uint Result=UINT32(GET_VALUE(Cmd->ByteMode,Op1)-1);
          SET_VALUE(Cmd->ByteMode,Op1,Result);
          Flags=Result==0 ? VM_FZ:Result&VM_FS;
        }
        break;
#ifdef VM_OPTIMIZE
      case VM_DECB:
        SET_VALUE(true,Op1,GET_VALUE(true,Op1)-1);
        break;
      case VM_DECD:
        SET_VALUE(false,Op1,GET_VALUE(false,Op1)-1);
        break;
#endif
      case VM_JMP:
        SET_IP(GET_VALUE(false,Op1));
        continue;
      case VM_XOR:
        {
          uint Result=UINT32(GET_VALUE(Cmd->ByteMode,Op1)^GET_VALUE(Cmd->ByteMode,Op2));
          Flags=Result==0 ? VM_FZ:Result&VM_FS;
          SET_VALUE(Cmd->ByteMode,Op1,Result);
        }
        break;
      case VM_AND:
        {
          uint Result=UINT32(GET_VALUE(Cmd->ByteMode,Op1)&GET_VALUE(Cmd->ByteMode,Op2));
          Flags=Result==0 ? VM_FZ:Result&VM_FS;
          SET_VALUE(Cmd->ByteMode,Op1,Result);
        }
        break;
      case VM_OR:
        {
          uint Result=UINT32(GET_VALUE(Cmd->ByteMode,Op1)|GET_VALUE(Cmd->ByteMode,Op2));
          Flags=Result==0 ? VM_FZ:Result&VM_FS;
          SET_VALUE(Cmd->ByteMode,Op1,Result);
        }
        break;
      case VM_TEST:
        {
          uint Result=UINT32(GET_VALUE(Cmd->ByteMode,Op1)&GET_VALUE(Cmd->ByteMode,Op2));
          Flags=Result==0 ? VM_FZ:Result&VM_FS;
        }
        break;
      case VM_JS:
        if ((Flags & VM_FS)!=0)
        {
          SET_IP(GET_VALUE(false,Op1));
          continue;
        }
        break;
      case VM_JNS:
        if ((Flags & VM_FS)==0)
        {
          SET_IP(GET_VALUE(false,Op1));
          continue;
        }
        break;
      case VM_JB:
        if ((Flags & VM_FC)!=0)
        {
          SET_IP(GET_VALUE(false,Op1));
          continue;
        }
        break;
      case VM_JBE:
        if ((Flags & (VM_FC|VM_FZ))!=0)
        {
          SET_IP(GET_VALUE(false,Op1));
          continue;
        }
        break;
      case VM_JA:
        if ((Flags & (VM_FC|VM_FZ))==0)
        {
          SET_IP(GET_VALUE(false,Op1));
          continue;
        }
        break;
      case VM_JAE:
        if ((Flags & VM_FC)==0)
        {
          SET_IP(GET_VALUE(false,Op1));
          continue;
        }
        break;