1 /*
2  * Copyright (C) 2014 Google, Inc.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package dagger.internal.codegen;
17 
18 import com.google.auto.common.MoreElements;
19 import com.google.common.base.Predicate;
20 import com.google.common.collect.FluentIterable;
21 import com.google.common.collect.ImmutableSet;
22 import java.util.Set;
23 import javax.inject.Inject;
24 import javax.lang.model.element.AnnotationMirror;
25 import javax.lang.model.element.ExecutableElement;
26 import javax.lang.model.element.Modifier;
27 import javax.lang.model.element.TypeElement;
28 import javax.lang.model.element.VariableElement;
29 import javax.lang.model.util.ElementFilter;
30 
31 import static com.google.auto.common.MoreElements.isAnnotationPresent;
32 import static dagger.internal.codegen.ErrorMessages.INJECT_CONSTRUCTOR_ON_ABSTRACT_CLASS;
33 import static dagger.internal.codegen.ErrorMessages.INJECT_CONSTRUCTOR_ON_INNER_CLASS;
34 import static dagger.internal.codegen.ErrorMessages.INJECT_INTO_PRIVATE_CLASS;
35 import static dagger.internal.codegen.ErrorMessages.INJECT_ON_PRIVATE_CONSTRUCTOR;
36 import static dagger.internal.codegen.ErrorMessages.MULTIPLE_INJECT_CONSTRUCTORS;
37 import static dagger.internal.codegen.ErrorMessages.MULTIPLE_QUALIFIERS;
38 import static dagger.internal.codegen.ErrorMessages.MULTIPLE_SCOPES;
39 import static dagger.internal.codegen.ErrorMessages.QUALIFIER_ON_INJECT_CONSTRUCTOR;
40 import static dagger.internal.codegen.InjectionAnnotations.getQualifiers;
41 import static dagger.internal.codegen.InjectionAnnotations.getScopes;
42 import static javax.lang.model.element.Modifier.ABSTRACT;
43 import static javax.lang.model.element.Modifier.PRIVATE;
44 import static javax.lang.model.element.Modifier.STATIC;
45 
46 /**
47  * A {@linkplain ValidationReport validator} for {@link Inject} constructors.
48  *
49  * @author Gregory Kick
50  * @since 2.0
51  */
52 final class InjectConstructorValidator {
validate(ExecutableElement constructorElement)53   ValidationReport<TypeElement> validate(ExecutableElement constructorElement) {
54     ValidationReport.Builder<TypeElement> builder =
55         ValidationReport.about(MoreElements.asType(constructorElement.getEnclosingElement()));
56     if (constructorElement.getModifiers().contains(PRIVATE)) {
57       builder.addError(INJECT_ON_PRIVATE_CONSTRUCTOR, constructorElement);
58     }
59 
60     for (AnnotationMirror qualifier : getQualifiers(constructorElement)) {
61       builder.addError(QUALIFIER_ON_INJECT_CONSTRUCTOR, constructorElement, qualifier);
62     }
63 
64     for (VariableElement parameter : constructorElement.getParameters()) {
65       ImmutableSet<? extends AnnotationMirror> qualifiers = getQualifiers(parameter);
66       if (qualifiers.size() > 1) {
67         for (AnnotationMirror qualifier : qualifiers) {
68           builder.addError(MULTIPLE_QUALIFIERS, constructorElement, qualifier);
69         }
70       }
71     }
72 
73     TypeElement enclosingElement =
74         MoreElements.asType(constructorElement.getEnclosingElement());
75     Set<Modifier> typeModifiers = enclosingElement.getModifiers();
76 
77     if (typeModifiers.contains(PRIVATE)) {
78       builder.addError(INJECT_INTO_PRIVATE_CLASS, constructorElement);
79     }
80 
81     if (typeModifiers.contains(ABSTRACT)) {
82       builder.addError(INJECT_CONSTRUCTOR_ON_ABSTRACT_CLASS, constructorElement);
83     }
84 
85     if (enclosingElement.getNestingKind().isNested()
86         && !typeModifiers.contains(STATIC)) {
87       builder.addError(INJECT_CONSTRUCTOR_ON_INNER_CLASS, constructorElement);
88     }
89 
90     // This is computationally expensive, but probably preferable to a giant index
91     FluentIterable<ExecutableElement> injectConstructors = FluentIterable.from(
92         ElementFilter.constructorsIn(enclosingElement.getEnclosedElements()))
93             .filter(new Predicate<ExecutableElement>() {
94               @Override public boolean apply(ExecutableElement input) {
95                 return isAnnotationPresent(input, Inject.class);
96               }
97             });
98 
99     if (injectConstructors.size() > 1) {
100       builder.addError(MULTIPLE_INJECT_CONSTRUCTORS, constructorElement);
101     }
102 
103     ImmutableSet<? extends AnnotationMirror> scopes = getScopes(enclosingElement);
104     if (scopes.size() > 1) {
105       for (AnnotationMirror scope : scopes) {
106         builder.addError(MULTIPLE_SCOPES, enclosingElement, scope);
107       }
108     }
109 
110     return builder.build();
111   }
112 }
113