void ThrowNullPointerExceptionFromDexPC()

in runtime/common_throws.cc [404:543]
126 lines of code
55 McCabe index (conditional complexity)

void ThrowNullPointerExceptionFromDexPC() {
  uint32_t throw_dex_pc;
  ArtMethod* method = Thread::Current()->GetCurrentMethod(&throw_dex_pc);
  const DexFile::CodeItem* code = method->GetCodeItem();
  CHECK_LT(throw_dex_pc, code->insns_size_in_code_units_);
  const Instruction* instr = Instruction::At(&code->insns_[throw_dex_pc]);
  switch (instr->Opcode()) {
    case Instruction::INVOKE_DIRECT:
      ThrowNullPointerExceptionForMethodAccess(instr->VRegB_35c(), kDirect);
      break;
    case Instruction::INVOKE_DIRECT_RANGE:
      ThrowNullPointerExceptionForMethodAccess(instr->VRegB_3rc(), kDirect);
      break;
    case Instruction::INVOKE_VIRTUAL:
      ThrowNullPointerExceptionForMethodAccess(instr->VRegB_35c(), kVirtual);
      break;
    case Instruction::INVOKE_VIRTUAL_RANGE:
      ThrowNullPointerExceptionForMethodAccess(instr->VRegB_3rc(), kVirtual);
      break;
    case Instruction::INVOKE_INTERFACE:
      ThrowNullPointerExceptionForMethodAccess(instr->VRegB_35c(), kInterface);
      break;
    case Instruction::INVOKE_INTERFACE_RANGE:
      ThrowNullPointerExceptionForMethodAccess(instr->VRegB_3rc(), kInterface);
      break;
    case Instruction::INVOKE_VIRTUAL_QUICK:
    case Instruction::INVOKE_VIRTUAL_RANGE_QUICK: {
      // Since we replaced the method index, we ask the verifier to tell us which
      // method is invoked at this location.
      ArtMethod* invoked_method =
          verifier::MethodVerifier::FindInvokedMethodAtDexPc(method, throw_dex_pc);
      if (invoked_method != nullptr) {
        // NPE with precise message.
        ThrowNullPointerExceptionForMethodAccess(invoked_method, kVirtual);
      } else {
        // NPE with imprecise message.
        ThrowNullPointerException("Attempt to invoke a virtual method on a null object reference");
      }
      break;
    }
    case Instruction::IGET:
    case Instruction::IGET_WIDE:
    case Instruction::IGET_OBJECT:
    case Instruction::IGET_BOOLEAN:
    case Instruction::IGET_BYTE:
    case Instruction::IGET_CHAR:
    case Instruction::IGET_SHORT: {
      ArtField* field =
          Runtime::Current()->GetClassLinker()->ResolveField(instr->VRegC_22c(), method, false);
      ThrowNullPointerExceptionForFieldAccess(field, true /* read */);
      break;
    }
    case Instruction::IGET_QUICK:
    case Instruction::IGET_BOOLEAN_QUICK:
    case Instruction::IGET_BYTE_QUICK:
    case Instruction::IGET_CHAR_QUICK:
    case Instruction::IGET_SHORT_QUICK:
    case Instruction::IGET_WIDE_QUICK:
    case Instruction::IGET_OBJECT_QUICK: {
      // Since we replaced the field index, we ask the verifier to tell us which
      // field is accessed at this location.
      ArtField* field =
          verifier::MethodVerifier::FindAccessedFieldAtDexPc(method, throw_dex_pc);
      if (field != nullptr) {
        // NPE with precise message.
        ThrowNullPointerExceptionForFieldAccess(field, true /* read */);
      } else {
        // NPE with imprecise message.
        ThrowNullPointerException("Attempt to read from a field on a null object reference");
      }
      break;
    }
    case Instruction::IPUT:
    case Instruction::IPUT_WIDE:
    case Instruction::IPUT_OBJECT:
    case Instruction::IPUT_BOOLEAN:
    case Instruction::IPUT_BYTE:
    case Instruction::IPUT_CHAR:
    case Instruction::IPUT_SHORT: {
      ArtField* field =
          Runtime::Current()->GetClassLinker()->ResolveField(instr->VRegC_22c(), method, false);
      ThrowNullPointerExceptionForFieldAccess(field, false /* write */);
      break;
    }
    case Instruction::IPUT_QUICK:
    case Instruction::IPUT_BOOLEAN_QUICK:
    case Instruction::IPUT_BYTE_QUICK:
    case Instruction::IPUT_CHAR_QUICK:
    case Instruction::IPUT_SHORT_QUICK:
    case Instruction::IPUT_WIDE_QUICK:
    case Instruction::IPUT_OBJECT_QUICK: {
      // Since we replaced the field index, we ask the verifier to tell us which
      // field is accessed at this location.
      ArtField* field =
          verifier::MethodVerifier::FindAccessedFieldAtDexPc(method, throw_dex_pc);
      if (field != nullptr) {
        // NPE with precise message.
        ThrowNullPointerExceptionForFieldAccess(field, false /* write */);
      } else {
        // NPE with imprecise message.
        ThrowNullPointerException("Attempt to write to a field on a null object reference");
      }
      break;
    }
    case Instruction::AGET:
    case Instruction::AGET_WIDE:
    case Instruction::AGET_OBJECT:
    case Instruction::AGET_BOOLEAN:
    case Instruction::AGET_BYTE:
    case Instruction::AGET_CHAR:
    case Instruction::AGET_SHORT:
      ThrowException("Ljava/lang/NullPointerException;", nullptr,
                     "Attempt to read from null array");
      break;
    case Instruction::APUT:
    case Instruction::APUT_WIDE:
    case Instruction::APUT_OBJECT:
    case Instruction::APUT_BOOLEAN:
    case Instruction::APUT_BYTE:
    case Instruction::APUT_CHAR:
    case Instruction::APUT_SHORT:
      ThrowException("Ljava/lang/NullPointerException;", nullptr,
                     "Attempt to write to null array");
      break;
    case Instruction::ARRAY_LENGTH:
      ThrowException("Ljava/lang/NullPointerException;", nullptr,
                     "Attempt to get length of null array");
      break;
    default: {
      // TODO: We should have covered all the cases where we expect a NPE above, this
      //       message/logging is so we can improve any cases we've missed in the future.
      const DexFile* dex_file =
          method->GetDeclaringClass()->GetDexCache()->GetDexFile();
      ThrowException("Ljava/lang/NullPointerException;", nullptr,
                     StringPrintf("Null pointer exception during instruction '%s'",
                                  instr->DumpString(dex_file).c_str()).c_str());
      break;
    }
  }
}