/* Capstone Disassembly Engine */

/* By Nguyen Anh Quynh <aquynh@gmail.com>, 2013-2019 */

#if defined(CAPSTONE_HAS_OSXKERNEL)

#include <Availability.h>

#include <libkern/libkern.h>

#else

#include <stdio.h>

#include <stdlib.h>

#endif

#include <string.h>

#include <assert.h>

#include "MCInst.h"

#include "utils.h"

#define MCINST_CACHE (ARR_SIZE(mcInst->Operands) - 1)

void MCInst_Init(MCInst *inst)

{

  // unnecessary to initialize in loop . its expensive and inst->size shuold be honored

  inst->Operands[0].Kind = kInvalid;

  inst->Operands[0].ImmVal = 0;

  inst->Opcode = 0;

  inst->OpcodePub = 0;

  inst->size = 0;

  inst->has_imm = false;

  inst->op1_size = 0;

  inst->ac_idx = 0;

  inst->popcode_adjust = 0;

  inst->assembly[0] = '\0';

  inst->wasm_data.type = WASM_OP_INVALID;

  inst->xAcquireRelease = 0;

  for (int i = 0; i < MAX_MC_OPS; ++i)

    inst->tied_op_idx[i] = -1;

  inst->isAliasInstr = false;

  inst->fillDetailOps = false;

}

void MCInst_clear(MCInst *inst)

{

  inst->size = 0;

}

// does not free @Op

void MCInst_insert0(MCInst *inst, int index, MCOperand *Op)

{

  assert(index < MAX_MC_OPS);

  int i;

  for(i = inst->size; i > index; i--)

    //memcpy(&(inst->Operands[i]), &(inst->Operands[i-1]), sizeof(MCOperand));

    inst->Operands[i] = inst->Operands[i-1];

  inst->Operands[index] = *Op;

  inst->size++;

}

void MCInst_setOpcode(MCInst *inst, unsigned Op)

{

  inst->Opcode = Op;

}

void MCInst_setOpcodePub(MCInst *inst, unsigned Op)

{

  inst->OpcodePub = Op;

}

unsigned MCInst_getOpcode(const MCInst *inst)

{

  return inst->Opcode;

}

unsigned MCInst_getOpcodePub(const MCInst *inst)

{

  return inst->OpcodePub;

}

MCOperand *MCInst_getOperand(MCInst *inst, unsigned i)

{

  assert(i < MAX_MC_OPS);

  return &inst->Operands[i];

}

unsigned MCInst_getNumOperands(const MCInst *inst)

{

  return inst->size;

}

// This addOperand2 function doesnt free Op

void MCInst_addOperand2(MCInst *inst, MCOperand *Op)

{

  assert(inst->size < MAX_MC_OPS);

  inst->Operands[inst->size] = *Op;

  inst->size++;

}

bool MCOperand_isValid(const MCOperand *op)

{

  return op->Kind != kInvalid;

}

bool MCOperand_isReg(const MCOperand *op)

{

  return op->Kind == kRegister;

}

bool MCOperand_isImm(const MCOperand *op)

{

  return op->Kind == kImmediate;

}

bool MCOperand_isFPImm(const MCOperand *op)

{

  return op->Kind == kFPImmediate;

}

bool MCOperand_isDFPImm(const MCOperand *op)

{

  return op->Kind == kDFPImmediate;

}

bool MCOperand_isExpr(const MCOperand *op)

{

  return op->Kind == kExpr;

}

bool MCOperand_isInst(const MCOperand *op)

{

  return op->Kind == kInst;

}

/// getReg - Returns the register number.

unsigned MCOperand_getReg(const MCOperand *op)

{

  return op->RegVal;

}

/// setReg - Set the register number.

void MCOperand_setReg(MCOperand *op, unsigned Reg)

{

  op->RegVal = Reg;

}

int64_t MCOperand_getImm(const MCOperand *op)

{

  return op->ImmVal;

}

void MCOperand_setImm(MCOperand *op, int64_t Val)

{

  op->ImmVal = Val;

}

double MCOperand_getFPImm(const MCOperand *op)

{

  return op->FPImmVal;

}

void MCOperand_setFPImm(MCOperand *op, double Val)

{

  op->FPImmVal = Val;

}

MCOperand *MCOperand_CreateReg1(MCInst *mcInst, unsigned Reg)

{

  MCOperand *op = &(mcInst->Operands[MCINST_CACHE]);

  op->MachineOperandType = kRegister;

  op->Kind = kRegister;

  op->RegVal = Reg;

  return op;

}

void MCOperand_CreateReg0(MCInst *mcInst, unsigned Reg)

{

  MCOperand *op = &(mcInst->Operands[mcInst->size]);

  mcInst->size++;

  op->MachineOperandType = kRegister;

  op->Kind = kRegister;

  op->RegVal = Reg;

}

MCOperand *MCOperand_CreateImm1(MCInst *mcInst, int64_t Val)

{

  MCOperand *op = &(mcInst->Operands[MCINST_CACHE]);

  op->MachineOperandType = kImmediate;

  op->Kind = kImmediate;

  op->ImmVal = Val;

  return op;

}

void MCOperand_CreateImm0(MCInst *mcInst, int64_t Val)

{

  assert(mcInst->size < MAX_MC_OPS);

  MCOperand *op = &(mcInst->Operands[mcInst->size]);

  mcInst->size++;

  op->MachineOperandType = kImmediate;

  op->Kind = kImmediate;

  op->ImmVal = Val;

}

/// Check if any operand of the MCInstrDesc is predicable

bool MCInst_isPredicable(const MCInstrDesc *MIDesc)

{

  const MCOperandInfo *OpInfo = MIDesc->OpInfo;

  unsigned NumOps = MIDesc->NumOperands;

  for (unsigned i = 0; i < NumOps; ++i) {

    if (MCOperandInfo_isPredicate(&OpInfo[i])) {

      return true;

    }

  }

  return false;

}

/// Checks if tied operands exist in the instruction and sets

/// - The writeback flag in detail

/// - Saves the indices of the tied destination operands.

void MCInst_handleWriteback(MCInst *MI, const MCInstrDesc *InstDesc)

{

  const MCOperandInfo *OpInfo = InstDesc[MCInst_getOpcode(MI)].OpInfo;

  unsigned short NumOps = InstDesc[MCInst_getOpcode(MI)].NumOperands;

  unsigned i;

  for (i = 0; i < NumOps; ++i) {

    if (MCOperandInfo_isTiedToOp(&OpInfo[i])) {

      int idx = MCOperandInfo_getOperandConstraint(

        &InstDesc[MCInst_getOpcode(MI)], i,

        MCOI_TIED_TO);

      if (idx == -1)

        continue;

      if (i >= MAX_MC_OPS) {

        assert(0 &&

               "Maximum number of MC operands reached.");

      }

      MI->tied_op_idx[i] = idx;

      if (MI->flat_insn->detail)

        MI->flat_insn->detail->writeback = true;

    }

  }

}

/// Check if operand with OpNum is tied by another operand

/// (operand is tying destination).

bool MCInst_opIsTied(const MCInst *MI, unsigned OpNum)

{

  assert(OpNum < MAX_MC_OPS && "Maximum number of MC operands exceeded.");

  for (int i = 0; i < MAX_MC_OPS; ++i) {

    if (MI->tied_op_idx[i] == OpNum)

      return true;

  }

  return false;

}

/// Check if operand with OpNum is tying another operand

/// (operand is tying src).

bool MCInst_opIsTying(const MCInst *MI, unsigned OpNum)

{

  assert(OpNum < MAX_MC_OPS && "Maximum number of MC operands exceeded.");

  return MI->tied_op_idx[OpNum] != -1;

}

/// Returns the value of the @MCInst operand at index @OpNum.

uint64_t MCInst_getOpVal(MCInst *MI, unsigned OpNum)

{

  assert(OpNum < MAX_MC_OPS);

  MCOperand *op = MCInst_getOperand(MI, OpNum);

  if (MCOperand_isReg(op))

    return MCOperand_getReg(op);

  else if (MCOperand_isImm(op))

    return MCOperand_getImm(op);

  else

    assert(0 && "Operand type not handled in this getter.");

  return MCOperand_getImm(op);

}

void MCInst_setIsAlias(MCInst *MI, bool Flag) {

  assert(MI);

  MI->isAliasInstr = Flag;

  MI->flat_insn->is_alias = Flag;

}

/// @brief Copies the relevant members of a temporary MCInst to

/// the main MCInst. This is used if TryDecode was run on a temporary MCInst.

/// @param MI The main MCInst

/// @param TmpMI The temporary MCInst.

void MCInst_updateWithTmpMI(MCInst *MI, MCInst *TmpMI) {

  MI->size = TmpMI->size;

  MI->Opcode = TmpMI->Opcode;

  assert(MI->size < MAX_MC_OPS);

  memcpy(MI->Operands, TmpMI->Operands, sizeof(MI->Operands[0]) * MI->size);

}