KT-2280 Recursive function declared in function results in VerifyError

#KT-2280 Fixed

A closure's constructor should not take an instance of itself as an
argument, because it would require caller to pass yet uninitialized
value. Instead it should initialize a corresponding field with 'this'

compiler/backend/src/org/jetbrains/jet/codegen/ClosureCodegen.java

@@ -146,7 +146,7 @@ public class ClosureCodegen extends ObjectOrClosureCodegen {
         if (enclosingType == null)
             captureThis = null;
 
-        final Method constructor = generateConstructor(funClass, fun);
+        final Method constructor = generateConstructor(funClass, fun, funDescriptor);
 
         if (captureThis != null) {
             cv.newField(fun, ACC_FINAL, "this$0", enclosingType.getDescriptor(), null, null);
@@ -160,6 +160,9 @@ public class ClosureCodegen extends ObjectOrClosureCodegen {
 
         final GeneratedAnonymousClassDescriptor answer = new GeneratedAnonymousClassDescriptor(name, constructor, captureThis, captureReceiver);
         for (DeclarationDescriptor descriptor : closure.keySet()) {
+            if (descriptor == funDescriptor) {
+                continue;
+            }
             if (descriptor instanceof VariableDescriptor) {
                 final EnclosedValueDescriptor valueDescriptor = closure.get(descriptor);
                 answer.addArg(valueDescriptor.getOuterValue());
@@ -253,13 +256,16 @@ public class ClosureCodegen extends ObjectOrClosureCodegen {
         }
     }
 
-    private Method generateConstructor(JvmClassName funClass, PsiElement fun) {
+    private Method generateConstructor(JvmClassName funClass, JetExpression fun, FunctionDescriptor funDescriptor) {
         int argCount = captureThis != null ? 1 : 0;
         argCount += (captureReceiver != null ? 1 : 0);
 
         ArrayList<DeclarationDescriptor> variableDescriptors = new ArrayList<DeclarationDescriptor>();
         
         for (DeclarationDescriptor descriptor : closure.keySet()) {
+            if (descriptor == funDescriptor) {
+                continue;
+            }
             if (descriptor instanceof VariableDescriptor && !(descriptor instanceof PropertyDescriptor)) {
                 argCount++;
                 variableDescriptors.add(descriptor);
@@ -284,7 +290,13 @@ public class ClosureCodegen extends ObjectOrClosureCodegen {
             argTypes[i++] = captureReceiver;
         }
 
+        boolean putFieldForMyself = false;
+
         for (DeclarationDescriptor descriptor : closure.keySet()) {
+            if (descriptor == funDescriptor) {
+                putFieldForMyself = true;
+                continue;
+            }
             if (descriptor instanceof VariableDescriptor && !(descriptor instanceof PropertyDescriptor)) {
                 final Type sharedVarType = state.getInjector().getJetTypeMapper().getSharedVarType(descriptor);
                 final Type type;
@@ -336,6 +348,14 @@ public class ClosureCodegen extends ObjectOrClosureCodegen {
                 StackValue.field(type, name, fieldName, false).store(type, iv);
             }
 
+            if (putFieldForMyself) {
+                Type type = name.getAsmType();
+                String fieldName = "$" + funDescriptor.getName();
+                iv.load(0, type);
+                iv.dup();
+                StackValue.field(type, name, fieldName, false).store(type, iv);
+            }
+
             iv.visitInsn(RETURN);
 
             FunctionCodegen.endVisit(iv, "constructor", fun);

compiler/testData/codegen/classes/recursiveClosure.kt

@@ -0,0 +1,7 @@
+fun foo(s: String): String {
+    fun bar(count: Int): String =
+        if (count == 0) s else bar(count - 1)
+    return bar(239)
+}
+
+fun box(): String = foo("OK")

compiler/testData/codegen/regressions/kt2280.kt

@@ -0,0 +1,7 @@
+fun box(): String {
+    fun rmrf(i: Int) {
+        if (i > 0) rmrf(i - 1)
+    }
+    rmrf(5)
+    return "OK"
+}

compiler/tests/org/jetbrains/jet/codegen/ClosuresGenTest.java

@@ -66,4 +66,8 @@ public class ClosuresGenTest extends CodegenTestCase {
     public void testKt2151() {
         blackBoxFile("regressions/kt2151.kt");
     }
+
+    public void testRecursiveClosure() {
+        blackBoxFile("classes/recursiveClosure.kt");
+    }
 }

compiler/tests/org/jetbrains/jet/codegen/FunctionGenTest.java

@@ -125,6 +125,10 @@ public class FunctionGenTest extends CodegenTestCase {
         blackBoxFile("regressions/kt2481.kt");
     }
 
+    public void testKt2280() {
+        blackBoxFile("regressions/kt2280.kt");
+    }
+
     public static class WithJavaFunctionGenTest extends CodegenTestCase {
         private void blackBoxFileWithJava(@NotNull String ktFile) throws Exception {
             File javaClassesTempDirectory = new File(FileUtil.getTempDirectory(), "java-classes");