IDEA-149813 Decompiler has lost generic parameter

src/org/jetbrains/java/decompiler/main/ClassWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2016 JetBrains s.r.o.
+ * Copyright 2000-2017 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.
@@ -331,16 +331,9 @@ public class ClassWriter {
       buffer.append("class ");
     }
 
-    GenericClassDescriptor descriptor = null;
-    if (DecompilerContext.getOption(IFernflowerPreferences.DECOMPILE_GENERIC_SIGNATURES)) {
-      StructGenericSignatureAttribute attr = (StructGenericSignatureAttribute)cl.getAttributes().getWithKey("Signature");
-      if (attr != null) {
-        descriptor = GenericMain.parseClassSignature(attr.getSignature());
-      }
-    }
-
     buffer.append(node.simpleName);
 
+    GenericClassDescriptor descriptor = getGenericClassDescriptor(cl);
     if (descriptor != null && !descriptor.fparameters.isEmpty()) {
       appendTypeParameters(buffer, descriptor.fparameters, descriptor.fbounds);
     }
@@ -1051,7 +1044,17 @@ public class ClassWriter {
     }
   }
 
-  private static void appendTypeParameters(TextBuffer buffer, List<String> parameters, List<List<GenericType>> bounds) {
+  public static GenericClassDescriptor getGenericClassDescriptor(StructClass cl) {
+    if (DecompilerContext.getOption(IFernflowerPreferences.DECOMPILE_GENERIC_SIGNATURES)) {
+      StructGenericSignatureAttribute attr = (StructGenericSignatureAttribute)cl.getAttributes().getWithKey("Signature");
+      if (attr != null) {
+        return GenericMain.parseClassSignature(attr.getSignature());
+      }
+    }
+    return null;
+  }
+
+  public static void appendTypeParameters(TextBuffer buffer, List<String> parameters, List<List<GenericType>> bounds) {
     buffer.append('<');
 
     for (int i = 0; i < parameters.size(); i++) {

src/org/jetbrains/java/decompiler/modules/decompiler/exps/NewExprent.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2015 JetBrains s.r.o.
+ * Copyright 2000-2017 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.
@@ -21,12 +21,15 @@ import org.jetbrains.java.decompiler.main.ClassesProcessor.ClassNode;
 import org.jetbrains.java.decompiler.main.DecompilerContext;
 import org.jetbrains.java.decompiler.main.TextBuffer;
 import org.jetbrains.java.decompiler.main.collectors.BytecodeMappingTracer;
+import org.jetbrains.java.decompiler.main.extern.IFernflowerLogger;
 import org.jetbrains.java.decompiler.main.extern.IFernflowerPreferences;
 import org.jetbrains.java.decompiler.modules.decompiler.ExprProcessor;
 import org.jetbrains.java.decompiler.modules.decompiler.vars.CheckTypesResult;
 import org.jetbrains.java.decompiler.modules.decompiler.vars.VarVersionPair;
 import org.jetbrains.java.decompiler.struct.StructClass;
 import org.jetbrains.java.decompiler.struct.gen.VarType;
+import org.jetbrains.java.decompiler.struct.gen.generics.GenericClassDescriptor;
+import org.jetbrains.java.decompiler.struct.gen.generics.GenericMain;
 import org.jetbrains.java.decompiler.util.InterpreterUtil;
 import org.jetbrains.java.decompiler.util.ListStack;
 
@@ -181,7 +184,23 @@ public class NewExprent extends Exprent {
             typename = typename.substring(typename.lastIndexOf('.') + 1);
           }
         }
-        buf.append(typename);
+
+        GenericClassDescriptor descriptor = ClassWriter.getGenericClassDescriptor(child.classStruct);
+        if (descriptor != null) {
+          if (descriptor.superinterfaces.isEmpty()) {
+            buf.append(GenericMain.getGenericCastTypeName(descriptor.superclass));
+          }
+          else {
+            if (descriptor.superinterfaces.size() > 1) {
+              DecompilerContext.getLogger().writeMessage("Inconsistent anonymous class signature: " + child.classStruct.qualifiedName,
+                                                         IFernflowerLogger.Severity.WARN);
+            }
+            buf.append(GenericMain.getGenericCastTypeName(descriptor.superinterfaces.get(0)));
+          }
+        }
+        else {
+          buf.append(typename);
+        }
       }
 
       buf.append('(');

test/org/jetbrains/java/decompiler/SingleClassesTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2016 JetBrains s.r.o.
+ * Copyright 2000-2017 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.
@@ -76,6 +76,7 @@ public class SingleClassesTest {
   @Test public void testInnerLocal() { doTest("pkg/TestInnerLocal"); }
   @Test public void testInnerLocalPkg() { doTest("pkg/TestInnerLocalPkg"); }
   @Test public void testInnerSignature() { doTest("pkg/TestInnerSignature"); }
+  @Test public void testAnonymousSignature() { doTest("pkg/TestAnonymousSignature"); }
   @Test public void testParameterizedTypes() { doTest("pkg/TestParameterizedTypes"); }
   @Test public void testShadowing() { doTest("pkg/TestShadowing", "pkg/Shadow", "ext/Shadow"); }
   @Test public void testStringConcat() { doTest("pkg/TestStringConcat"); }

testData/results/TestAnonymousSignature.dec

@@ -0,0 +1,50 @@
+package pkg;
+
+import java.util.ArrayList;
+import java.util.Comparator;
+
+public class TestAnonymousSignature {
+   public static void main(String[] var0) {
+      System.out.println(new ArrayList<String>() {// 25
+         public int size() {
+            return super.size();// 28
+         }
+      });
+      System.out.println(new Comparator<String>() {// 33
+         public int compare(String var1, String var2) {
+            return 0;// 36
+         }
+      });
+   }// 39
+}
+
+class 'pkg/TestAnonymousSignature$1' {
+   method 'size ()I' {
+      1      9
+      4      9
+   }
+}
+
+class 'pkg/TestAnonymousSignature$2' {
+   method 'compare (Ljava/lang/String;Ljava/lang/String;)I' {
+      0      14
+      1      14
+   }
+}
+
+class 'pkg/TestAnonymousSignature' {
+   method 'main ([Ljava/lang/String;)V' {
+      0      7
+      a      7
+      d      12
+      17      12
+      1a      17
+   }
+}
+
+Lines mapping:
+25 <-> 8
+28 <-> 10
+33 <-> 13
+36 <-> 15
+39 <-> 18

testData/src/pkg/TestAnonymousSignature.java

@@ -0,0 +1,40 @@
+/*
+ * 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 pkg;
+
+import java.util.ArrayList;
+import java.util.Comparator;
+
+public class TestAnonymousSignature {
+  public static void main(String[] args) {
+    // anonymous from class
+    System.out.println(new ArrayList<String>() {
+      @Override
+      public int size() {
+        return super.size();
+      }
+    });
+
+    // anonymous from class
+    System.out.println(new Comparator<String>() {
+      @Override
+      public int compare(String o1, String o2) {
+        return 0;
+      }
+    });
+  }
+}