/**
* Fixes the error by assigning the result of the call to the receiver reference, or deleting the
* method call.
*/
public Description describe(MethodInvocationTree methodInvocationTree, VisitorState state) {
// Find the root of the field access chain, i.e. a.intern().trim() ==> a.
ExpressionTree identifierExpr = ASTHelpers.getRootAssignable(methodInvocationTree);
String identifierStr = null;
Type identifierType = null;
if (identifierExpr != null) {
identifierStr = identifierExpr.toString();
if (identifierExpr instanceof JCIdent) {
identifierType = ((JCIdent) identifierExpr).sym.type;
} else if (identifierExpr instanceof JCFieldAccess) {
identifierType = ((JCFieldAccess) identifierExpr).sym.type;
} else {
throw new IllegalStateException("Expected a JCIdent or a JCFieldAccess");
}
}
Type returnType =
ASTHelpers.getReturnType(((JCMethodInvocation) methodInvocationTree).getMethodSelect());
Fix fix;
if (identifierStr != null
&& !"this".equals(identifierStr)
&& returnType != null
&& state.getTypes().isAssignable(returnType, identifierType)) {
// Fix by assigning the assigning the result of the call to the root receiver reference.
fix = SuggestedFix.prefixWith(methodInvocationTree, identifierStr + " = ");
} else {
// Unclear what the programmer intended. Delete since we don't know what else to do.
Tree parent = state.getPath().getParentPath().getLeaf();
fix = SuggestedFix.delete(parent);
}
return describeMatch(methodInvocationTree, fix);
}
@Override
protected boolean matchArgument(ExpressionTree tree, VisitorState state) {
Type type = ASTHelpers.getType(tree);
if (!type.isReference()) {
return false;
}
ClassTree classTree = ASTHelpers.findEnclosingNode(state.getPath(), ClassTree.class);
if (classTree == null) {
return false;
}
Type classType = ASTHelpers.getType(classTree);
if (classType == null) {
return false;
}
if (inEqualsOrCompareTo(classType, type, state)) {
return false;
}
if (ASTHelpers.isSubtype(type, state.getSymtab().enumSym.type, state)) {
return false;
}
if (ASTHelpers.isSubtype(type, state.getSymtab().classType, state)) {
return false;
}
if (!implementsEquals(type, state)) {
return false;
}
return true;
}
@Override
public Description matchClass(ClassTree classTree, VisitorState state) {
TypeSymbol symbol = ASTHelpers.getSymbol(classTree);
if (symbol.getKind() != ElementKind.CLASS) {
return Description.NO_MATCH;
}
MethodTree equals = null;
for (Tree member : classTree.getMembers()) {
if (!(member instanceof MethodTree)) {
continue;
}
MethodTree methodTree = (MethodTree) member;
if (EQUALS_MATCHER.matches(methodTree, state)) {
equals = methodTree;
}
}
if (equals == null) {
return Description.NO_MATCH;
}
MethodSymbol hashCodeSym =
ASTHelpers.resolveExistingMethod(
state,
symbol,
state.getName("hashCode"),
ImmutableList.<Type>of(),
ImmutableList.<Type>of());
if (hashCodeSym.owner.equals(state.getSymtab().objectType.tsym)) {
return describeMatch(equals);
}
return Description.NO_MATCH;
}
@Override
public boolean matches(TryTree tryTree, VisitorState state) {
return ASTHelpers.findEnclosingNode(state.getPath(), DoWhileLoopTree.class) != null
|| ASTHelpers.findEnclosingNode(state.getPath(), EnhancedForLoopTree.class) != null
|| ASTHelpers.findEnclosingNode(state.getPath(), WhileLoopTree.class) != null
|| ASTHelpers.findEnclosingNode(state.getPath(), ForLoopTree.class) != null;
}
@Override
public boolean matches(ExpressionTree expressionTree, VisitorState state) {
Symbol sym = ASTHelpers.getSymbol(expressionTree);
if (sym == null) {
return false;
}
if (!(sym instanceof MethodSymbol)) {
throw new IllegalArgumentException(
"DescendantOf matcher expects a method call but found "
+ sym.getClass()
+ ". Expression: "
+ expressionTree);
}
if (sym.isStatic()) {
return false;
}
if (methodName.equals(sym.toString())) {
Type accessedReferenceType = sym.owner.type;
Type collectionType = state.getTypeFromString(fullClassName);
if (collectionType != null) {
return state
.getTypes()
.isSubtype(accessedReferenceType, state.getTypes().erasure(collectionType));
}
}
return false;
}
/** Return true if the given type is 'void' or 'Void'. */
public static boolean isVoidType(Type type, VisitorState state) {
if (type == null) {
return false;
}
return type.getKind() == TypeKind.VOID
|| state.getTypes().isSameType(Suppliers.JAVA_LANG_VOID_TYPE.get(state), type);
}
/** Returns true if {@code erasure(s) == erasure(t)}. */
public static boolean isSameType(Type s, Type t, VisitorState state) {
if (s == null || t == null) {
return false;
}
Types types = state.getTypes();
return types.isSameType(types.erasure(s), types.erasure(t));
}
@Override
public Description matchMethod(MethodTree methodTree, VisitorState state) {
// if method is itself annotated with @Inject or it has no ancestor methods, return NO_MATCH;
if (hasInjectAnnotation().matches(methodTree, state)) {
return Description.NO_MATCH;
}
boolean foundJavaxInject = false;
for (MethodSymbol superMethod :
ASTHelpers.findSuperMethods(ASTHelpers.getSymbol(methodTree), state.getTypes())) {
// With a Guice annotation, Guice will still inject the subclass-overridden method.
if (ASTHelpers.hasAnnotation(superMethod, GUICE_INJECT_ANNOTATION, state)) {
return Description.NO_MATCH;
}
// is not necessarily a match even if we find javax Inject on an ancestor
// since a higher up ancestor may have @com.google.inject.Inject
foundJavaxInject |= ASTHelpers.hasAnnotation(superMethod, JAVAX_INJECT_ANNOTATION, state);
}
if (foundJavaxInject) {
return describeMatch(
methodTree,
SuggestedFix.builder()
.addImport(JAVAX_INJECT_ANNOTATION)
.prefixWith(methodTree, "@Inject\n")
.build());
}
return Description.NO_MATCH;
}
/**
* Determines whether a symbol has an annotation of the given type. This includes annotations
* inherited from superclasses due to @Inherited.
*
* @param annotationType The type of the annotation to look for (e.g, "javax.annotation.Nullable")
*/
public static boolean hasAnnotation(Symbol sym, String annotationType, VisitorState state) {
Symbol annotationSym = state.getSymbolFromString(annotationType);
Symbol inheritedSym = state.getSymtab().inheritedType.tsym;
if ((sym == null) || (annotationSym == null)) {
return false;
}
if ((sym instanceof ClassSymbol) && (annotationSym.attribute(inheritedSym) != null)) {
while (sym != null) {
if (sym.attribute(annotationSym) != null) {
return true;
}
sym = ((ClassSymbol) sym).getSuperclass().tsym;
}
return false;
} else {
return sym.attribute(annotationSym) != null;
}
}
private boolean inEqualsOrCompareTo(Type classType, Type type, VisitorState state) {
MethodTree methodTree = ASTHelpers.findEnclosingNode(state.getPath(), MethodTree.class);
if (methodTree == null) {
return false;
}
MethodSymbol sym = ASTHelpers.getSymbol(methodTree);
if (sym == null || sym.isStatic()) {
return false;
}
Symbol compareTo = getOnlyMember(state, state.getSymtab().comparableType, "compareTo");
Symbol equals = getOnlyMember(state, state.getSymtab().objectType, "equals");
if (!sym.overrides(compareTo, classType.tsym, state.getTypes(), false)
&& !sym.overrides(equals, classType.tsym, state.getTypes(), false)) {
return false;
}
if (!ASTHelpers.isSameType(type, classType, state)) {
return false;
}
return true;
}
/** Check if the method declares or inherits an implementation of .equals() */
public static boolean implementsEquals(Type type, VisitorState state) {
Name equalsName = state.getName("equals");
Symbol objectEquals = getOnlyMember(state, state.getSymtab().objectType, "equals");
for (Type sup : state.getTypes().closure(type)) {
if (sup.tsym.isInterface()) {
continue;
}
if (ASTHelpers.isSameType(sup, state.getSymtab().objectType, state)) {
return false;
}
WriteableScope scope = sup.tsym.members();
if (scope == null) {
continue;
}
for (Symbol sym : scope.getSymbolsByName(equalsName)) {
if (sym.overrides(objectEquals, type.tsym, state.getTypes(), false)) {
return true;
}
}
}
return false;
}
@Override
public boolean matches(TryTree tryTree, VisitorState state) {
MethodTree enclosingMethodTree =
ASTHelpers.findEnclosingNode(state.getPath(), MethodTree.class);
Name name = enclosingMethodTree.getName();
return JUnitMatchers.looksLikeJUnit3SetUp.matches(enclosingMethodTree, state)
|| JUnitMatchers.looksLikeJUnit3TearDown.matches(enclosingMethodTree, state)
|| name.contentEquals("main")
// TODO(schmitt): Move to JUnitMatchers?
|| name.contentEquals("suite")
|| Matchers.hasAnnotation(JUNIT_BEFORE_ANNOTATION).matches(enclosingMethodTree, state)
|| Matchers.hasAnnotation(JUNIT_AFTER_ANNOTATION).matches(enclosingMethodTree, state);
}
private static Symbol getOnlyMember(VisitorState state, Type type, String name) {
return getOnlyElement(type.tsym.members().getSymbolsByName(state.getName(name)));
}
@Override
public Type get(VisitorState state) {
return ((JCTree) state.findEnclosing(ClassTree.class)).type;
}
@Override
public Type get(VisitorState state) {
return state.getSymtab().annotationType;
}
@Override
public Type get(VisitorState state) {
return state.getSymtab().objectType;
}
@Override
public Type get(VisitorState state) {
return state.getSymtab().booleanType;
}
@Override
public Type get(VisitorState state) {
return state.getTypeFromString("java.lang.Boolean");
}
/**
* Returns the {@link Nullness} for an expression as determined by the nullness dataflow analysis.
*/
public static Nullness getNullnessValue(
ExpressionTree expr, VisitorState state, NullnessAnalysis nullnessAnalysis) {
TreePath pathToExpr = new TreePath(state.getPath(), expr);
return nullnessAnalysis.getNullness(pathToExpr, state.context);
}