Method StepInternal

src/interp/interp.cc:1315–2187

}

RunResult Thread::StepInternal(Trap::Ptr* out_trap) {
  using O = Opcode;

  u32& pc = frames_.back().offset;
  auto& istream = mod_->desc().istream;

  if (trace_stream_) {
    istream.Trace(trace_stream_, pc, trace_source_.get());
  }

  // clang-format off
  auto instr = istream.Read(&pc);
  switch (instr.op) {
    case O::Unreachable:
      return TRAP("unreachable executed");

    case O::Br:
      pc = instr.imm_u32;
      break;

    case O::BrIf:
      if (Pop<u32>()) {
        pc = instr.imm_u32;
      }
      break;

    case O::BrOnNonNull: {
      Ref ref = Pop<Ref>();
      if (ref != Ref::Null) {
        Push(ref);
        pc = instr.imm_u32;
      }
      break;
    }

    case O::BrOnNull: {
      Ref ref = Pop<Ref>();
      if (ref == Ref::Null) {
        pc = instr.imm_u32;
      } else {
        Push(ref);
      }
      break;
    }

    case O::BrTable: {
      auto key = Pop<u32>();
      if (key >= instr.imm_u32) {
        key = instr.imm_u32;
      }
      pc += key * Istream::kBrTableEntrySize;
      break;
    }

    case O::Return:
      return PopCall();

    case O::Call: {