1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
|
/*
* Copyright (C) 2013-2014 The Project Lombok Authors.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package lombok.javac.handlers;
import static lombok.javac.Javac.*;
import static lombok.javac.handlers.JavacHandlerUtil.*;
import org.mangosdk.spi.ProviderFor;
import com.sun.tools.javac.tree.JCTree.JCAnnotation;
import com.sun.tools.javac.tree.JCTree.JCBinary;
import com.sun.tools.javac.tree.JCTree.JCBlock;
import com.sun.tools.javac.tree.JCTree.JCExpression;
import com.sun.tools.javac.tree.JCTree.JCIdent;
import com.sun.tools.javac.tree.JCTree.JCIf;
import com.sun.tools.javac.tree.JCTree.JCLiteral;
import com.sun.tools.javac.tree.JCTree.JCMethodDecl;
import com.sun.tools.javac.tree.JCTree.JCParens;
import com.sun.tools.javac.tree.JCTree.JCStatement;
import com.sun.tools.javac.tree.JCTree.JCSynchronized;
import com.sun.tools.javac.tree.JCTree.JCThrow;
import com.sun.tools.javac.tree.JCTree.JCTry;
import com.sun.tools.javac.tree.JCTree.JCVariableDecl;
import com.sun.tools.javac.util.List;
import lombok.NonNull;
import lombok.core.AnnotationValues;
import lombok.core.HandlerPriority;
import lombok.core.AST.Kind;
import lombok.javac.JavacAnnotationHandler;
import lombok.javac.JavacNode;
import static lombok.javac.JavacTreeMaker.TypeTag.*;
import static lombok.javac.JavacTreeMaker.TreeTag.*;
@ProviderFor(JavacAnnotationHandler.class)
@HandlerPriority(value = 512) // 2^9; onParameter=@__(@NonNull) has to run first.
public class HandleNonNull extends JavacAnnotationHandler<NonNull> {
@Override public void handle(AnnotationValues<NonNull> annotation, JCAnnotation ast, JavacNode annotationNode) {
if (annotationNode.up().getKind() == Kind.FIELD) {
// This is meaningless unless the field is used to generate a method (@Setter, @RequiredArgsConstructor, etc),
// but in that case those handlers will take care of it. However, we DO check if the annotation is applied to
// a primitive, because those handlers trigger on any annotation named @NonNull and we only want the warning
// behaviour on _OUR_ 'lombok.NonNull'.
try {
if (isPrimitive(((JCVariableDecl) annotationNode.up().get()).vartype)) {
annotationNode.addWarning("@NonNull is meaningless on a primitive.");
}
} catch (Exception ignore) {}
return;
}
if (annotationNode.up().getKind() != Kind.ARGUMENT) return;
JCMethodDecl declaration;
try {
declaration = (JCMethodDecl) annotationNode.up().up().get();
} catch (Exception e) {
return;
}
// if (JavacHandlerUtil.isGenerated(declaration)) return;
if (declaration.body == null) {
annotationNode.addWarning("@NonNull is meaningless on a parameter of an abstract method.");
return;
}
// Possibly, if 'declaration instanceof ConstructorDeclaration', fetch declaration.constructorCall, search it for any references to our parameter,
// and if they exist, create a new method in the class: 'private static <T> T lombok$nullCheck(T expr, String msg) {if (expr == null) throw NPE; return expr;}' and
// wrap all references to it in the super/this to a call to this method.
JCStatement nullCheck = recursiveSetGeneratedBy(generateNullCheck(annotationNode.getTreeMaker(), annotationNode.up()), ast, annotationNode.getContext());
if (nullCheck == null) {
// @NonNull applied to a primitive. Kinda pointless. Let's generate a warning.
annotationNode.addWarning("@NonNull is meaningless on a primitive.");
return;
}
List<JCStatement> statements = declaration.body.stats;
String expectedName = annotationNode.up().getName();
/* Abort if the null check is already there, delving into try and synchronized statements */ {
List<JCStatement> stats = statements;
int idx = 0;
while (stats.size() > idx) {
JCStatement stat = stats.get(idx++);
if (JavacHandlerUtil.isConstructorCall(stat)) continue;
if (stat instanceof JCTry) {
stats = ((JCTry) stat).body.stats;
idx = 0;
continue;
}
if (stat instanceof JCSynchronized) {
stats = ((JCSynchronized) stat).body.stats;
idx = 0;
continue;
}
String varNameOfNullCheck = returnVarNameIfNullCheck(stat);
if (varNameOfNullCheck == null) break;
if (varNameOfNullCheck.equals(expectedName)) return;
}
}
List<JCStatement> tail = statements;
List<JCStatement> head = List.nil();
for (JCStatement stat : statements) {
if (JavacHandlerUtil.isConstructorCall(stat) || (JavacHandlerUtil.isGenerated(stat) && isNullCheck(stat))) {
tail = tail.tail;
head = head.prepend(stat);
continue;
}
break;
}
List<JCStatement> newList = tail.prepend(nullCheck);
for (JCStatement stat : head) newList = newList.prepend(stat);
declaration.body.stats = newList;
}
public boolean isNullCheck(JCStatement stat) {
return returnVarNameIfNullCheck(stat) != null;
}
/**
* Checks if the statement is of the form 'if (x == null) {throw WHATEVER;},
* where the block braces are optional. If it is of this form, returns "x".
* If it is not of this form, returns null.
*/
public String returnVarNameIfNullCheck(JCStatement stat) {
if (!(stat instanceof JCIf)) return null;
/* Check that the if's statement is a throw statement, possibly in a block. */ {
JCStatement then = ((JCIf) stat).thenpart;
if (then instanceof JCBlock) {
List<JCStatement> stats = ((JCBlock) then).stats;
if (stats.length() == 0) return null;
then = stats.get(0);
}
if (!(then instanceof JCThrow)) return null;
}
/* Check that the if's conditional is like 'x == null'. Return from this method (don't generate
a nullcheck) if 'x' is equal to our own variable's name: There's already a nullcheck here. */ {
JCExpression cond = ((JCIf) stat).cond;
while (cond instanceof JCParens) cond = ((JCParens) cond).expr;
if (!(cond instanceof JCBinary)) return null;
JCBinary bin = (JCBinary) cond;
if (!CTC_EQUAL.equals(treeTag(bin))) return null;
if (!(bin.lhs instanceof JCIdent)) return null;
if (!(bin.rhs instanceof JCLiteral)) return null;
if (!CTC_BOT.equals(typeTag(bin.rhs))) return null;
return ((JCIdent) bin.lhs).name.toString();
}
}
}
|
