IDEA-127301: handling of static method references

src/de/fernflower/main/ClassWriter.java

@@ -134,6 +134,16 @@ public class ClassWriter {
 
 		DecompilerContext.getLogger().startWriteClass(node.simpleName);
 
+		if(node.lambda_information.is_method_reference) {
+
+			writer.write(ExprProcessor.getCastTypeName(new VarType(node.lambda_information.content_class_name, false)));
+    		writer.write("::");
+    		writer.write(node.lambda_information.content_method_name);
+    
+    		writer.flush();
+			
+		} else {
+		
     		// lambda method
     		StructMethod mt = cl.getMethod(node.lambda_information.content_method_key);
     		MethodWrapper meth = wrapper.getMethodWrapper(mt.getName(), mt.getDescriptor());
@@ -191,6 +201,7 @@ public class ClassWriter {
     		writer.write(InterpreterUtil.getIndentString(indent));
     		writer.write("}");
     		writer.flush();
+		}
 
 		DecompilerContext.setProperty(DecompilerContext.CURRENT_CLASSNODE, nodeold);
 

src/de/fernflower/main/ClassesProcessor.java

@@ -41,6 +41,7 @@ import de.fernflower.modules.decompiler.exps.InvocationExprent;
 import de.fernflower.modules.decompiler.vars.VarVersionPaar;
 import de.fernflower.struct.StructClass;
 import de.fernflower.struct.StructContext;
+import de.fernflower.struct.StructMethod;
 import de.fernflower.struct.attr.StructInnerClassesAttribute;
 import de.fernflower.struct.gen.VarType;
 import de.fernflower.util.InterpreterUtil;
@@ -378,7 +379,7 @@ public class ClassesProcessor {
 		
 		public LambdaInformation lambda_information;
 		
-		public ClassNode(String content_method_name, String content_method_descriptor, String lambda_class_name, String lambda_method_name, 
+		public ClassNode(String content_class_name, String content_method_name, String content_method_descriptor, String lambda_class_name, String lambda_method_name, 
 												String lambda_method_descriptor, StructClass classStruct) { // lambda class constructor
 			this.type = CLASS_LAMBDA;
 			this.classStruct = classStruct; // 'parent' class containing the static function 
@@ -389,13 +390,22 @@ public class ClassesProcessor {
 			lambda_information.method_name = lambda_method_name;
 			lambda_information.method_descriptor = lambda_method_descriptor;
 			
+			lambda_information.content_class_name = content_class_name;
 			lambda_information.content_method_name = content_method_name;
 			lambda_information.content_method_descriptor = content_method_descriptor;
 			lambda_information.content_method_key = InterpreterUtil.makeUniqueKey(lambda_information.content_method_name, lambda_information.content_method_descriptor);
 
 			anonimousClassType = new VarType(lambda_class_name, true);
 			
-			lambda_information.is_content_method_static = ((classStruct.getMethod(content_method_name, content_method_descriptor).getAccessFlags() & CodeConstants.ACC_STATIC) != 0);
+			if(content_class_name != classStruct.qualifiedName) { // method reference. FIXME: class name alone doesn't cover it. Synthetic flag seems to be the only 'reliable' difference.
+				lambda_information.is_method_reference = true;
+				lambda_information.is_content_method_static = true; // FIXME: consider argument flag
+			} else {
+				StructMethod mt = classStruct.getMethod(content_method_name, content_method_descriptor);
+
+				lambda_information.is_method_reference = false;
+				lambda_information.is_content_method_static = ((mt.getAccessFlags() & CodeConstants.ACC_STATIC) != 0);
+			}
 		}
 		
 		public ClassNode(int type, StructClass classStruct) {
@@ -419,10 +429,13 @@ public class ClassesProcessor {
 			public String method_name;
 			public String method_descriptor;
 			
+			public String content_class_name;
 			public String content_method_name;
 			public String content_method_descriptor;
+			
 			public String content_method_key;
 			
+			public boolean is_method_reference;
 			public boolean is_content_method_static; 
 		}
 	}

src/de/fernflower/main/rels/LambdaProcessor.java

@@ -50,7 +50,9 @@ public class LambdaProcessor {
 		}
 		
 		StructBootstrapMethodsAttribute bootstrap = (StructBootstrapMethodsAttribute)cl.getAttributes().getWithKey(StructGeneralAttribute.ATTRIBUTE_BOOTSTRAP_METHODS);
-		if(bootstrap != null && bootstrap.getMethodsNumber() > 0) {
+		if(bootstrap == null || bootstrap.getMethodsNumber() == 0) {
+			return false; // no bootstrap constants in pool
+		}
 
 		Set<Integer> lambda_methods = new HashSet<Integer>();
 		
@@ -66,7 +68,7 @@ public class LambdaProcessor {
 		}
 		
 		if(lambda_methods.isEmpty()) {
-				return false;
+			return false; // no lambda bootstrap constant found 
 		}
 		
 		Map<String, String> mapMethodsLambda = new HashMap<String, String>(); 
@@ -96,8 +98,8 @@ public class LambdaProcessor {
 							
 							LinkConstant content_method_handle = (LinkConstant)bootstrap_arguments.get(1);
 
-								ClassNode node_lambda = clprocessor.new ClassNode(content_method_handle.elementname, content_method_handle.descriptor, lambda_class_name, 
-																																	lambda_method_name, lambda_method_descriptor, cl);
+							ClassNode node_lambda = clprocessor.new ClassNode(content_method_handle.classname, content_method_handle.elementname, content_method_handle.descriptor, 
+									                                          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());
 
@@ -110,6 +112,8 @@ public class LambdaProcessor {
 					}
 				}
 			}
+			
+			mt.releaseResources();
 		}
 		
 		// build class hierarchy on lambda 
@@ -127,8 +131,6 @@ public class LambdaProcessor {
 		
 		// FIXME: mixed hierarchy? 
 			
-		}
-		
 		return false;
 	}
 	

src/de/fernflower/main/rels/NestedClassProcessor.java

@@ -112,6 +112,10 @@ public class NestedClassProcessor {
 	
 	private void setLambdaVars(ClassNode parent, ClassNode child) {
 
+		if(child.lambda_information.is_method_reference) { // method reference, no code and no parameters
+			return;
+		}
+		
 		final MethodWrapper meth = parent.wrapper.getMethods().getWithKey(child.lambda_information.content_method_key);
 		final MethodWrapper encmeth = parent.wrapper.getMethods().getWithKey(child.enclosingMethod);