Implemented better rendering for parameters with default values in decompiler and descriptor renderer.

#KT-1582 fixed

compiler/frontend/src/org/jetbrains/jet/resolve/DescriptorRenderer.java

@@ -79,7 +79,11 @@ public class DescriptorRenderer implements Renderer<DeclarationDescriptor> {
 
         @Override
         public Void visitValueParameterDescriptor(ValueParameterDescriptor descriptor, StringBuilder builder) {
-            return super.visitVariableDescriptor(descriptor, builder);
+            super.visitVariableDescriptor(descriptor, builder);
+            if (descriptor.hasDefaultValue()) {
+                builder.append(" = ...");
+            }
+            return null;
         }
     };
 

compiler/testData/renderer/GlobalFunctions.kt

@@ -15,7 +15,7 @@ public fun Int.ext() : Int {}
 //internal final fun int() : jet.String defined in <module>.<root>.rendererTest
 //internal final fun int2(val ints : jet.IntArray) : jet.Int defined in <module>.<root>.rendererTest
 //value-parameter vararg val ints : jet.IntArray defined in <module>.<root>.rendererTest.int2
-//private final fun prv(val a : jet.String, val b : jet.Int) : jet.Int defined in <module>.<root>.rendererTest
+//private final fun prv(val a : jet.String, val b : jet.Int = ...) : jet.Int defined in <module>.<root>.rendererTest
 //value-parameter val a : jet.String defined in <module>.<root>.rendererTest.prv
 //value-parameter val b : jet.Int defined in <module>.<root>.rendererTest.prv
 //public final fun jet.Int.ext() : jet.Int defined in <module>.<root>.rendererTest

idea/src/org/jetbrains/jet/plugin/libraries/DecompiledDataFactory.java

@@ -179,7 +179,9 @@ class DecompiledDataFactory {
 
     private void appendDescriptor(DeclarationDescriptor descriptor, String indent) {
         int startOffset = myBuilder.length();
-        myBuilder.append(DescriptorRenderer.COMPACT.render(descriptor));
+        String renderedDescriptor = DescriptorRenderer.COMPACT.render(descriptor);
+        renderedDescriptor = renderedDescriptor.replace("= ...", "= " + DECOMPILED_COMMENT);
+        myBuilder.append(renderedDescriptor);
         int endOffset = myBuilder.length();
 
         if (descriptor instanceof FunctionDescriptor || descriptor instanceof PropertyDescriptor) {

idea/testData/libraries/decompiled/namespace.kt

@@ -17,7 +17,7 @@ package testData.libraries
 
 [public final fun func(val a : jet.Int, val b : jet.Int) : Unit { /* compiled code */ }]
 
-[public final fun func(val a : jet.Int, val b : jet.String) : Unit { /* compiled code */ }]
+[public final fun func(val a : jet.Int, val b : jet.String = /* compiled code */) : Unit { /* compiled code */ }]
 
 [public final fun func(val str : jet.String) : Unit { /* compiled code */ }]