Approximating flexible types in decompiled text

idea/idea-analysis/src/org/jetbrains/jet/plugin/libraries/DecompiledTextFactory.kt

@@ -30,6 +30,8 @@ import org.jetbrains.jet.lang.resolve.DescriptorUtils.isEnumEntry
 import org.jetbrains.jet.lang.resolve.DescriptorUtils.isSyntheticClassObject
 import org.jetbrains.jet.lang.types.error.MissingDependencyErrorClass
 import org.jetbrains.jet.lang.resolve.dataClassUtils.isComponentLike
+import org.jetbrains.jet.plugin.util.IdeDescriptorRenderers
+import org.jetbrains.jet.lang.types.isFlexible
 
 public fun buildDecompiledText(
         classFile: VirtualFile,
@@ -53,9 +55,12 @@ public fun buildDecompiledText(
 }
 
 private val DECOMPILED_COMMENT = "/* compiled code */"
+private val FLEXIBLE_TYPE_COMMENT = "/* platform type */"
+
 public val descriptorRendererForDecompiler: DescriptorRenderer = DescriptorRendererBuilder()
         .setWithDefinedIn(false)
         .setClassWithPrimaryConstructor(true)
+        .setTypeNormalizer(IdeDescriptorRenderers.APPROXIMATE_FLEXIBLE_TYPES)
         .build()
 
 //TODO: should use more accurate way to identify descriptors
@@ -99,6 +104,13 @@ private fun buildDecompiledText(packageFqName: FqName, descriptors: List<Declara
         builder.append(header)
         var endOffset = builder.length()
 
+        if (descriptor is CallableDescriptor) {
+            //NOTE: assuming that only return types can be flexible
+            if (descriptor.getReturnType().isFlexible()) {
+                builder.append(" ").append(FLEXIBLE_TYPE_COMMENT)
+            }
+        }
+
         if (descriptor is FunctionDescriptor || descriptor is PropertyDescriptor) {
             if ((descriptor as MemberDescriptor).getModality() != Modality.ABSTRACT) {
                 if (descriptor is FunctionDescriptor) {

idea/testData/libraries/decompiledText/FlexibleTypes.expected.kt

@@ -0,0 +1,12 @@
+// IntelliJ API Decompiler stub source generated from a class file
+// Implementation of methods is not available
+
+package test
+
+internal abstract class FlexibleTypes() {
+    internal abstract val p: kotlin.Int? /* platform type */
+
+    internal abstract fun collection(): kotlin.List<kotlin.Any> /* platform type */
+
+    internal final fun withBody(): kotlin.Int? /* platform type */ { /* compiled code */ }
+}

idea/testData/libraries/decompiledText/FlexibleTypes/FlexibleTypes.kt

@@ -0,0 +1,11 @@
+package test
+
+import kotlin.internal.flexible.ft
+
+abstract class FlexibleTypes() {
+    abstract fun collection(): ft<List<Int>, List<Any>>
+
+    abstract val p: ft<Int, Int?>
+
+    fun withBody(): ft<Int, Int?> { return 1 }
+}

idea/testData/libraries/decompiledText/FlexibleTypes/ft.kt

@@ -0,0 +1,3 @@
+package kotlin.internal.flexible
+
+class ft<L, U>

idea/tests/org/jetbrains/jet/plugin/libraries/DecompiledTextTestGenerated.java

@@ -61,6 +61,12 @@ public class DecompiledTextTestGenerated extends AbstractDecompiledTextTest {
         doTest(fileName);
     }
 
+    @TestMetadata("FlexibleTypes")
+    public void testFlexibleTypes() throws Exception {
+        String fileName = JetTestUtils.navigationMetadata("idea/testData/libraries/decompiledText/FlexibleTypes/");
+        doTest(fileName);
+    }
+
     @TestMetadata("FunctionTypes")
     public void testFunctionTypes() throws Exception {
         String fileName = JetTestUtils.navigationMetadata("idea/testData/libraries/decompiledText/FunctionTypes/");