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
|
package org.jetbrains.java.decompiler.main.rels;
import java.io.IOException;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.jetbrains.java.decompiler.code.CodeConstants;
import org.jetbrains.java.decompiler.code.Instruction;
import org.jetbrains.java.decompiler.code.InstructionSequence;
import org.jetbrains.java.decompiler.main.ClassesProcessor;
import org.jetbrains.java.decompiler.main.ClassesProcessor.ClassNode;
import org.jetbrains.java.decompiler.main.DecompilerContext;
import org.jetbrains.java.decompiler.struct.StructClass;
import org.jetbrains.java.decompiler.struct.StructMethod;
import org.jetbrains.java.decompiler.struct.attr.StructBootstrapMethodsAttribute;
import org.jetbrains.java.decompiler.struct.attr.StructGeneralAttribute;
import org.jetbrains.java.decompiler.struct.consts.LinkConstant;
import org.jetbrains.java.decompiler.struct.consts.PooledConstant;
import org.jetbrains.java.decompiler.struct.consts.PrimitiveConstant;
import org.jetbrains.java.decompiler.struct.gen.MethodDescriptor;
import org.jetbrains.java.decompiler.util.InterpreterUtil;
public class LambdaProcessor {
private static final String JAVAC_LAMBDA_CLASS = "java/lang/invoke/LambdaMetafactory";
private static final String JAVAC_LAMBDA_METHOD = "metafactory";
private static final String JAVAC_LAMBDA_METHOD_DESCRIPTOR = "(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;";
public void processClass(ClassNode node) throws IOException {
for(ClassNode child : node.nested) {
processClass(child);
}
if(node.nested.isEmpty()) {
hasLambda(node);
}
}
public boolean hasLambda(ClassNode node) throws IOException {
ClassesProcessor clprocessor = DecompilerContext.getClassprocessor();
StructClass cl = node.classStruct;
if(cl.getBytecodeVersion() < CodeConstants.BYTECODE_JAVA_8) { // lamda beginning with Java 8
return false;
}
StructBootstrapMethodsAttribute bootstrap = (StructBootstrapMethodsAttribute)cl.getAttributes().getWithKey(StructGeneralAttribute.ATTRIBUTE_BOOTSTRAP_METHODS);
if(bootstrap == null || bootstrap.getMethodsNumber() == 0) {
return false; // no bootstrap constants in pool
}
Set<Integer> lambda_methods = new HashSet<Integer>();
// find lambda bootstrap constants
for(int i = 0; i < bootstrap.getMethodsNumber(); ++i) {
LinkConstant method_ref = bootstrap.getMethodReference(i); // method handle
if(JAVAC_LAMBDA_CLASS.equals(method_ref.classname) &&
JAVAC_LAMBDA_METHOD.equals(method_ref.elementname) &&
JAVAC_LAMBDA_METHOD_DESCRIPTOR.equals(method_ref.descriptor)) { // check for javac lambda structure. FIXME: extend for Eclipse etc. at some point
lambda_methods.add(i);
}
}
if(lambda_methods.isEmpty()) {
return false; // no lambda bootstrap constant found
}
Map<String, String> mapMethodsLambda = new HashMap<String, String>();
// iterate over code and find invocations of bootstrap methods. Replace them with anonymous classes.
for(StructMethod mt: cl.getMethods()) {
mt.expandData();
InstructionSequence seq = mt.getInstructionSequence();
if(seq != null && seq.length() > 0) {
int len = seq.length();
for(int i = 0; i < len; ++i) {
Instruction instr = seq.getInstr(i);
if(instr.opcode == CodeConstants.opc_invokedynamic) {
LinkConstant invoke_dynamic = cl.getPool().getLinkConstant(instr.getOperand(0));
if(lambda_methods.contains(invoke_dynamic.index1)) { // lambda invocation found
List<PooledConstant> bootstrap_arguments = bootstrap.getMethodArguments(invoke_dynamic.index1);
MethodDescriptor md = MethodDescriptor.parseDescriptor(invoke_dynamic.descriptor);
String lambda_class_name = md.ret.value;
String lambda_method_name = invoke_dynamic.elementname;
String lambda_method_descriptor = ((PrimitiveConstant)bootstrap_arguments.get(2)).getString(); // method type
LinkConstant content_method_handle = (LinkConstant)bootstrap_arguments.get(1);
ClassNode node_lambda = clprocessor.new ClassNode(content_method_handle.classname, content_method_handle.elementname,
content_method_handle.descriptor, content_method_handle.index1,
lambda_class_name, lambda_method_name, lambda_method_descriptor, cl);
node_lambda.simpleName = cl.qualifiedName + "##Lambda_" + invoke_dynamic.index1 + "_" + invoke_dynamic.index2;
node_lambda.enclosingMethod = InterpreterUtil.makeUniqueKey(mt.getName(), mt.getDescriptor());
node.nested.add(node_lambda);
node_lambda.parent = node;
clprocessor.getMapRootClasses().put(node_lambda.simpleName, node_lambda);
mapMethodsLambda.put(node_lambda.lambda_information.content_method_key, node_lambda.simpleName);
}
}
}
}
mt.releaseResources();
}
// build class hierarchy on lambda
for(ClassNode nd : node.nested) {
if(nd.type == ClassNode.CLASS_LAMBDA) {
String parent_class_name = mapMethodsLambda.get(nd.enclosingMethod);
if(parent_class_name != null) {
ClassNode parent_class = clprocessor.getMapRootClasses().get(parent_class_name);
parent_class.nested.add(nd);
nd.parent = parent_class;
}
}
}
// FIXME: mixed hierarchy?
return false;
}
}
|
