@Override
public Description matchCompilationUnit(CompilationUnitTree tree, VisitorState state) {
if (tree.getTypeDecls().size() <= 1) {
// package-info.java files have zero top-level declarations, everything
// else should have exactly one.
return Description.NO_MATCH;
}
if (tree.getPackageName() == null) {
// Real code doesn't use the default package.
return Description.NO_MATCH;
}
List<String> names = new ArrayList<>();
for (Tree member : tree.getTypeDecls()) {
if (member instanceof ClassTree) {
ClassTree classMember = (ClassTree) member;
switch (classMember.getKind()) {
case CLASS:
case INTERFACE:
case ANNOTATION_TYPE:
case ENUM:
SuppressWarnings suppression =
ASTHelpers.getAnnotation(classMember, SuppressWarnings.class);
if (suppression != null
&& !Collections.disjoint(Arrays.asList(suppression.value()), allNames())) {
// If any top-level classes have @SuppressWarnings("TopLevel"), ignore
// this compilation unit. We can't rely on the normal suppression
// mechanism because the only enclosing element is the package declaration,
// and @SuppressWarnings can't be applied to packages.
return Description.NO_MATCH;
}
names.add(classMember.getSimpleName().toString());
break;
default:
break;
}
}
}
if (names.size() <= 1) {
// this can happen with multiple type declarations if some of them are
// empty (e.g. ";" at the top level counts as an empty type decl)
return Description.NO_MATCH;
}
String message =
String.format(
"Expected at most one top-level class declaration, instead found: %s",
Joiner.on(", ").join(names));
return buildDescription(tree.getPackageName()).setMessage(message).build();
}
private boolean suppressWarning(Declaration declaration, String warning) {
SuppressWarnings suppressionInfo = declaration.getAnnotation(SuppressWarnings.class);
return suppressionInfo != null && Arrays.asList(suppressionInfo.value()).contains(warning);
}