bool MethodVerifier::VerifyInstruction()

in runtime/verifier/method_verifier.cc [1099:1211]
104 lines of code
53 McCabe index (conditional complexity)

bool MethodVerifier::VerifyInstruction(const Instruction* inst, uint32_t code_offset) {
  if (UNLIKELY(inst->IsExperimental())) {
    // Experimental instructions don't yet have verifier support implementation.
    // While it is possible to use them by themselves, when we try to use stable instructions
    // with a virtual register that was created by an experimental instruction,
    // the data flow analysis will fail.
    Fail(VERIFY_ERROR_FORCE_INTERPRETER)
        << "experimental instruction is not supported by verifier; skipping verification";
    have_pending_experimental_failure_ = true;
    return false;
  }

  bool result = true;
  switch (inst->GetVerifyTypeArgumentA()) {
    case Instruction::kVerifyRegA:
      result = result && CheckRegisterIndex(inst->VRegA());
      break;
    case Instruction::kVerifyRegAWide:
      result = result && CheckWideRegisterIndex(inst->VRegA());
      break;
  }
  switch (inst->GetVerifyTypeArgumentB()) {
    case Instruction::kVerifyRegB:
      result = result && CheckRegisterIndex(inst->VRegB());
      break;
    case Instruction::kVerifyRegBField:
      result = result && CheckFieldIndex(inst->VRegB());
      break;
    case Instruction::kVerifyRegBMethod:
      result = result && CheckMethodIndex(inst->VRegB());
      break;
    case Instruction::kVerifyRegBNewInstance:
      result = result && CheckNewInstance(inst->VRegB());
      break;
    case Instruction::kVerifyRegBString:
      result = result && CheckStringIndex(inst->VRegB());
      break;
    case Instruction::kVerifyRegBType:
      result = result && CheckTypeIndex(inst->VRegB());
      break;
    case Instruction::kVerifyRegBWide:
      result = result && CheckWideRegisterIndex(inst->VRegB());
      break;
  }
  switch (inst->GetVerifyTypeArgumentC()) {
    case Instruction::kVerifyRegC:
      result = result && CheckRegisterIndex(inst->VRegC());
      break;
    case Instruction::kVerifyRegCField:
      result = result && CheckFieldIndex(inst->VRegC());
      break;
    case Instruction::kVerifyRegCNewArray:
      result = result && CheckNewArray(inst->VRegC());
      break;
    case Instruction::kVerifyRegCType:
      result = result && CheckTypeIndex(inst->VRegC());
      break;
    case Instruction::kVerifyRegCWide:
      result = result && CheckWideRegisterIndex(inst->VRegC());
      break;
    case Instruction::kVerifyRegCString:
      result = result && CheckStringIndex(inst->VRegC());
      break;
  }
  switch (inst->GetVerifyExtraFlags()) {
    case Instruction::kVerifyArrayData:
      result = result && CheckArrayData(code_offset);
      break;
    case Instruction::kVerifyBranchTarget:
      result = result && CheckBranchTarget(code_offset);
      break;
    case Instruction::kVerifySwitchTargets:
      result = result && CheckSwitchTargets(code_offset);
      break;
    case Instruction::kVerifyVarArgNonZero:
      // Fall-through.
    case Instruction::kVerifyVarArg: {
      // Instructions that can actually return a negative value shouldn't have this flag.
      uint32_t v_a = dchecked_integral_cast<uint32_t>(inst->VRegA());
      if ((inst->GetVerifyExtraFlags() == Instruction::kVerifyVarArgNonZero && v_a == 0) ||
          v_a > Instruction::kMaxVarArgRegs) {
        Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid arg count (" << v_a << ") in "
                                             "non-range invoke";
        return false;
      }

      uint32_t args[Instruction::kMaxVarArgRegs];
      inst->GetVarArgs(args);
      result = result && CheckVarArgRegs(v_a, args);
      break;
    }
    case Instruction::kVerifyVarArgRangeNonZero:
      // Fall-through.
    case Instruction::kVerifyVarArgRange:
      if (inst->GetVerifyExtraFlags() == Instruction::kVerifyVarArgRangeNonZero &&
          inst->VRegA() <= 0) {
        Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "invalid arg count (" << inst->VRegA() << ") in "
                                             "range invoke";
        return false;
      }
      result = result && CheckVarArgRangeRegs(inst->VRegA(), inst->VRegC());
      break;
    case Instruction::kVerifyError:
      Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "unexpected opcode " << inst->Name();
      result = false;
      break;
  }
  if (inst->GetVerifyIsRuntimeOnly() && Runtime::Current()->IsAotCompiler() && !verify_to_dump_) {
    Fail(VERIFY_ERROR_BAD_CLASS_HARD) << "opcode only expected at runtime " << inst->Name();
    result = false;
  }
  return result;
}