1 files changed, 151 insertions, 0 deletions
diff --git a/plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/main/rels/LambdaProcessor.java b/plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/main/rels/LambdaProcessor.java
new file mode 100644
index 000000000000..743ce1215381
--- /dev/null
+++ b/plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/main/rels/LambdaProcessor.java
@@ -0,0 +1,151 @@
+/*
+ * Copyright 2000-2014 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jetbrains.java.decompiler.main.rels;
+
+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;
+
+import java.io.IOException;
+import java.util.*;
+
+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 = 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;
+  }
+}