neo-decompiler 0.11.0

export function findMnemonicFrom(instructions, start, mnemonic) {
  for (let i = start; i < instructions.length; i++) {
    if (instructions[i].opcode.mnemonic === mnemonic) return i;
  }
  return -1;
}

export function findTryFrom(instructions, start) {
  for (let i = start; i < instructions.length; i++) {
    const mnemonic = instructions[i].opcode.mnemonic;
    if (mnemonic === "TRY" || mnemonic === "TRY_L") return i;
  }
  return -1;
}

export function tryHandlerTargets(instruction) {
  if (instruction.opcode.mnemonic !== "TRY" && instruction.opcode.mnemonic !== "TRY_L") {
    return null;
  }

  const operand = instruction.operand;
  if (operand === null || operand.kind !== "Bytes") {
    return null;
  }

  const bytes = operand.value;
  let catchDelta;
  let finallyDelta;

  if (bytes.length === 2) {
    catchDelta = bytes[0];
    finallyDelta = bytes[1];
    if (catchDelta > 127) catchDelta -= 256;
    if (finallyDelta > 127) finallyDelta -= 256;
  } else if (bytes.length === 8) {
    catchDelta = bytes[0] | (bytes[1] << 8) | (bytes[2] << 16) | (bytes[3] << 24);
    finallyDelta = bytes[4] | (bytes[5] << 8) | (bytes[6] << 16) | (bytes[7] << 24);
    if (catchDelta > 2147483647) catchDelta -= 4294967296;
    if (finallyDelta > 2147483647) finallyDelta -= 4294967296;
  } else {
    return null;
  }

  const width = 1 + bytes.length;
  const bodyStart = instruction.offset + width;

  let catchTarget = null;
  if (catchDelta !== 0) {
    const target = instruction.offset + catchDelta;
    if (target > instruction.offset) {
      catchTarget = target;
    }
  }

  let finallyTarget = null;
  if (finallyDelta !== 0) {
    const target = instruction.offset + finallyDelta;
    if (target > instruction.offset) {
      finallyTarget = target;
    }
  }

  return { bodyStart, catchTarget, finallyTarget };
}