Examples with UnionTypeTree com.sun.source.tree.UnionTypeTree used on opensource projects

Example 1 with UnionTypeTree

use of com.sun.source.tree.UnionTypeTree in project error-prone by google.

the class ClassNewInstance method fixExceptions.

// if the match occurrs inside the body of a try statement with existing catch clauses
// update or add a catch block to handle the new exceptions
private boolean fixExceptions(final VisitorState state, SuggestedFix.Builder fix) {
    TryTree tryTree = null;
    OUTER: for (TreePath path = state.getPath(); path != null; path = path.getParentPath()) {
        if (path.getLeaf() instanceof CatchTree) {
            // don't add more catch blocks if newInstance() was called in a catch block
            return false;
        } else if (path.getLeaf() instanceof TryTree && !((TryTree) path.getLeaf()).getCatches().isEmpty()) {
            tryTree = (TryTree) path.getLeaf();
            break;
        }
    }
    if (tryTree == null) {
        return false;
    }
    ImmutableMap.Builder<Type, CatchTree> catches = ImmutableMap.builder();
    for (CatchTree c : tryTree.getCatches()) {
        catches.put(ASTHelpers.getType(c.getParameter().getType()), c);
    }
    UnhandledResult<CatchTree> result = unhandled(catches.build(), state);
    if (result.unhandled.isEmpty()) {
        // no fix needed
        return true;
    }
    {
        // if there's an existing multi-catch at the end that handles reflective exceptions,
        // replace all of them with ROE and leave any non-reflective exceptions.
        // earlier catch blocks are left unchanged.
        CatchTree last = Iterables.getLast(tryTree.getCatches());
        Tree lastType = last.getParameter().getType();
        if (lastType.getKind() == Tree.Kind.UNION_TYPE) {
            Type roe = state.getTypeFromString(ReflectiveOperationException.class.getName());
            Set<String> exceptions = new LinkedHashSet<>();
            boolean foundReflective = false;
            for (Tree alternate : ((UnionTypeTree) lastType).getTypeAlternatives()) {
                if (ASTHelpers.isSubtype(ASTHelpers.getType(alternate), roe, state)) {
                    foundReflective = true;
                    exceptions.add("ReflectiveOperationException");
                } else {
                    exceptions.add(state.getSourceForNode(alternate));
                }
            }
            if (foundReflective) {
                fix.replace(lastType, Joiner.on(" | ").join(exceptions));
                return true;
            }
        }
    }
    // check for duplicated catch blocks that handle reflective exceptions exactly the same way,
    // and merge them into a single block that catches ROE
    Set<String> uniq = new HashSet<>();
    for (CatchTree ct : result.handles.values()) {
        uniq.add(state.getSourceForNode(ct.getBlock()));
    }
    // the catch blocks are all unique, append a new fresh one
    if (uniq.size() != 1) {
        CatchTree last = Iterables.getLast(tryTree.getCatches());
        // borrow the variable name of the previous catch variable, in case the naive 'e' conflicts
        // with something in the current scope
        String name = last.getParameter().getName().toString();
        fix.postfixWith(last, String.format("catch (ReflectiveOperationException %s) {" + " throw new LinkageError(%s.getMessage(), %s); }", name, name, name));
        return true;
    }
    // if the catch blocks contain calls to newInstance, don't delete any of them to avoid
    // overlapping fixes
    final AtomicBoolean newInstanceInCatch = new AtomicBoolean(false);
    ((JCTree) result.handles.values().iterator().next()).accept(new TreeScanner() {

        @Override
        public void visitApply(JCTree.JCMethodInvocation tree) {
            if (NEW_INSTANCE.matches(tree, state)) {
                newInstanceInCatch.set(true);
            }
        }
    });
    if (newInstanceInCatch.get()) {
        fix.replace(Iterables.getLast(result.handles.values()).getParameter().getType(), "ReflectiveOperationException");
        return true;
    }
    // otherwise, merge the duplicated catch blocks into a single block that
    // handles ROE
    boolean first = true;
    for (CatchTree ct : result.handles.values()) {
        if (first) {
            fix.replace(ct.getParameter().getType(), "ReflectiveOperationException");
            first = false;
        } else {
            fix.delete(ct);
        }
    }
    return true;
}