private Description checkForReadBeforeInit()

in nullaway/src/main/java/com/uber/nullaway/NullAway.java [1185:1245]
50 lines of code
17 McCabe index (conditional complexity)

  private Description checkForReadBeforeInit(ExpressionTree tree, VisitorState state) {
    // do a bunch of filtering.  first, filter out anything outside an initializer
    TreePath path = state.getPath();
    TreePath enclosingBlockPath;
    if (config.assertsEnabled()) {
      enclosingBlockPath = NullabilityUtil.findEnclosingMethodOrLambdaOrInitializer(path);
    } else {
      enclosingBlockPath =
          NullabilityUtil.findEnclosingMethodOrLambdaOrInitializer(
              path, ImmutableSet.of(Tree.Kind.ASSERT));
    }
    if (enclosingBlockPath == null) {
      // is this possible?
      return Description.NO_MATCH;
    }
    if (!config.assertsEnabled()
        && enclosingBlockPath.getLeaf().getKind().equals(Tree.Kind.ASSERT)) {
      return Description.NO_MATCH;
    }
    if (!relevantInitializerMethodOrBlock(enclosingBlockPath, state)) {
      return Description.NO_MATCH;
    }

    // now, make sure we have a field read
    Symbol symbol = ASTHelpers.getSymbol(tree);
    if (symbol == null) {
      return Description.NO_MATCH;
    }
    if (!symbol.getKind().equals(ElementKind.FIELD)) {
      return Description.NO_MATCH;
    }

    // for static fields, make sure the enclosing init is a static method or block
    if (isStatic(symbol)) {
      Tree enclosing = enclosingBlockPath.getLeaf();
      if (enclosing instanceof MethodTree
          && !ASTHelpers.getSymbol((MethodTree) enclosing).isStatic()) {
        return Description.NO_MATCH;
      } else if (enclosing instanceof BlockTree && !((BlockTree) enclosing).isStatic()) {
        return Description.NO_MATCH;
      }
    }
    if (okToReadBeforeInitialized(path, state)) {
      // writing the field, not reading it
      return Description.NO_MATCH;
    }

    // check that the field might actually be problematic to read
    FieldInitEntities entities =
        castToNonNull(class2Entities.get(enclosingClassSymbol(enclosingBlockPath)));
    if (!(entities.nonnullInstanceFields().contains(symbol)
        || entities.nonnullStaticFields().contains(symbol))) {
      // field is either nullable or initialized at declaration
      return Description.NO_MATCH;
    }
    if (errorBuilder.symbolHasSuppressWarningsAnnotation(symbol, INITIALIZATION_CHECK_NAME)) {
      // also suppress checking read before init, as we may not find explicit initialization
      return Description.NO_MATCH;
    }
    return checkPossibleUninitFieldRead(tree, state, symbol, path, enclosingBlockPath);
  }