aboutsummaryrefslogtreecommitdiff
path: root/src/core/lombok/javac/handlers/HandleCleanup.java
blob: cbbdc007da27a00fef1815cf418a02978ccb59b7 (plain)
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
/*
 * Copyright © 2009-2010 Reinier Zwitserloot, Roel Spilker and Robbert Jan Grootjans.
 * 
 * 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.handlers.JavacHandlerUtil.markAnnotationAsProcessed;
import lombok.Cleanup;
import lombok.core.AnnotationValues;
import lombok.core.AST.Kind;
import lombok.javac.JavacAnnotationHandler;
import lombok.javac.JavacNode;

import org.mangosdk.spi.ProviderFor;

import com.sun.tools.javac.code.TypeTags;
import com.sun.tools.javac.tree.JCTree;
import com.sun.tools.javac.tree.TreeMaker;
import com.sun.tools.javac.tree.JCTree.JCAnnotation;
import com.sun.tools.javac.tree.JCTree.JCAssign;
import com.sun.tools.javac.tree.JCTree.JCBinary;
import com.sun.tools.javac.tree.JCTree.JCBlock;
import com.sun.tools.javac.tree.JCTree.JCCase;
import com.sun.tools.javac.tree.JCTree.JCCatch;
import com.sun.tools.javac.tree.JCTree.JCExpression;
import com.sun.tools.javac.tree.JCTree.JCExpressionStatement;
import com.sun.tools.javac.tree.JCTree.JCFieldAccess;
import com.sun.tools.javac.tree.JCTree.JCIdent;
import com.sun.tools.javac.tree.JCTree.JCIf;
import com.sun.tools.javac.tree.JCTree.JCMethodDecl;
import com.sun.tools.javac.tree.JCTree.JCMethodInvocation;
import com.sun.tools.javac.tree.JCTree.JCStatement;
import com.sun.tools.javac.tree.JCTree.JCTypeCast;
import com.sun.tools.javac.tree.JCTree.JCVariableDecl;
import com.sun.tools.javac.util.List;
import com.sun.tools.javac.util.Name;

/**
 * Handles the {@code lombok.Cleanup} annotation for javac.
 */
@ProviderFor(JavacAnnotationHandler.class)
public class HandleCleanup implements JavacAnnotationHandler<Cleanup> {
	@Override public boolean handle(AnnotationValues<Cleanup> annotation, JCAnnotation ast, JavacNode annotationNode) {
		markAnnotationAsProcessed(annotationNode, Cleanup.class);
		String cleanupName = annotation.getInstance().value();
		if (cleanupName.length() == 0) {
			annotationNode.addError("cleanupName cannot be the empty string.");
			return true;
		}
		
		if (annotationNode.up().getKind() != Kind.LOCAL) {
			annotationNode.addError("@Cleanup is legal only on local variable declarations.");
			return true;
		}
		
		JCVariableDecl decl = (JCVariableDecl)annotationNode.up().get();
		
		if (decl.init == null) {
			annotationNode.addError("@Cleanup variable declarations need to be initialized.");
			return true;
		}
		
		JavacNode ancestor = annotationNode.up().directUp();
		JCTree blockNode = ancestor.get();
		
		final List<JCStatement> statements;
		if (blockNode instanceof JCBlock) {
			statements = ((JCBlock)blockNode).stats;
		} else if (blockNode instanceof JCCase) {
			statements = ((JCCase)blockNode).stats;
		} else if (blockNode instanceof JCMethodDecl) {
			statements = ((JCMethodDecl)blockNode).body.stats;
		} else {
			annotationNode.addError("@Cleanup is legal only on a local variable declaration inside a block.");
			return true;
		}
		
		boolean seenDeclaration = false;
		List<JCStatement> tryBlock = List.nil();
		List<JCStatement> newStatements = List.nil();
		for (JCStatement statement : statements) {
			if (!seenDeclaration) {
				if (statement == decl) seenDeclaration = true;
				newStatements = newStatements.append(statement);
			} else {
				tryBlock = tryBlock.append(statement);
			}
		}
		
		if (!seenDeclaration) {
			annotationNode.addError("LOMBOK BUG: Can't find this local variable declaration inside its parent.");
			return true;
		}
		
		doAssignmentCheck(annotationNode, tryBlock, decl.name);
		
		TreeMaker maker = annotationNode.getTreeMaker();
		JCFieldAccess cleanupMethod = maker.Select(maker.Ident(decl.name), annotationNode.toName(cleanupName));
		List<JCStatement> cleanupCall = List.<JCStatement>of(maker.Exec(
				maker.Apply(List.<JCExpression>nil(), cleanupMethod, List.<JCExpression>nil())));
		
		JCMethodInvocation preventNullAnalysis = maker.Apply(List.<JCExpression>nil(), JavacHandlerUtil.chainDotsString(maker, annotationNode, "lombok.Lombok.preventNullAnalysis"), List.<JCExpression>of(maker.Ident(decl.name)));
		JCBinary isNull = maker.Binary(JCTree.NE, preventNullAnalysis, maker.Literal(TypeTags.BOT, null));
		
		JCIf ifNotNullCleanup = maker.If(isNull, maker.Block(0, cleanupCall), null);
		
		JCBlock finalizer = maker.Block(0, List.<JCStatement>of(ifNotNullCleanup));
		
		newStatements = newStatements.append(maker.Try(maker.Block(0, tryBlock), List.<JCCatch>nil(), finalizer));
		
		if (blockNode instanceof JCBlock) {
			((JCBlock)blockNode).stats = newStatements;
		} else if (blockNode instanceof JCCase) {
			((JCCase)blockNode).stats = newStatements;
		} else if (blockNode instanceof JCMethodDecl) {
			((JCMethodDecl)blockNode).body.stats = newStatements;
		} else throw new AssertionError("Should not get here");
		
		ancestor.rebuild();
		
		return true;
	}
	
	private void doAssignmentCheck(JavacNode node, List<JCStatement> statements, Name name) {
		for (JCStatement statement : statements) doAssignmentCheck0(node, statement, name);
	}
	
	private void doAssignmentCheck0(JavacNode node, JCTree statement, Name name) {
		if (statement instanceof JCAssign) doAssignmentCheck0(node, ((JCAssign)statement).rhs, name);
		if (statement instanceof JCExpressionStatement) doAssignmentCheck0(node,
				((JCExpressionStatement)statement).expr, name);
		if (statement instanceof JCVariableDecl) doAssignmentCheck0(node, ((JCVariableDecl)statement).init, name);
		if (statement instanceof JCTypeCast) doAssignmentCheck0(node, ((JCTypeCast)statement).expr, name);
		if (statement instanceof JCIdent) {
			if (((JCIdent)statement).name.contentEquals(name)) {
				JavacNode problemNode = node.getNodeFor(statement);
				if (problemNode != null) problemNode.addWarning(
				"You're assigning an auto-cleanup variable to something else. This is a bad idea.");
			}
		}
	}
	
	@Override public boolean isResolutionBased() {
		return false;
	}
}