From 08a90ba7d488b9ff265658e3a6d5c02d9b88f183 Mon Sep 17 00:00:00 2001
From: Andrey Breslav <andrey.breslav@jetbrains.com>
Date: Thu, 10 Oct 2013 14:02:28 +0400
Subject: [PATCH] Fixing EA-50643 - NPE: PropertyCodegen.generateBackingField

Do not return null as a method/field visitor
---
 .../jetbrains/jet/codegen/ClassBuilder.java   | 22 ++++++++++++++-----
 .../jet/asJava/StubClassBuilder.java          |  6 +++--
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/compiler/backend/src/org/jetbrains/jet/codegen/ClassBuilder.java b/compiler/backend/src/org/jetbrains/jet/codegen/ClassBuilder.java
index dcb6c102e34..f36a4510650 100644
--- a/compiler/backend/src/org/jetbrains/jet/codegen/ClassBuilder.java
+++ b/compiler/backend/src/org/jetbrains/jet/codegen/ClassBuilder.java
@@ -19,12 +19,12 @@ package org.jetbrains.jet.codegen;
 import com.intellij.psi.PsiElement;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
-import org.jetbrains.asm4.AnnotationVisitor;
-import org.jetbrains.asm4.ClassVisitor;
-import org.jetbrains.asm4.FieldVisitor;
-import org.jetbrains.asm4.MethodVisitor;
+import org.jetbrains.asm4.*;
 
 public abstract class ClassBuilder {
+    protected static final MethodVisitor EMPTY_METHOD_VISITOR = new MethodVisitor(Opcodes.ASM4) {};
+    protected static final FieldVisitor EMPTY_FIELD_VISITOR = new FieldVisitor(Opcodes.ASM4) {};
+
     private String thisName;
 
     private final MemberMap members = new MemberMap();
@@ -43,6 +43,7 @@ public abstract class ClassBuilder {
         }
     }
 
+    @NotNull
     public FieldVisitor newField(
             @Nullable PsiElement origin,
             int access,
@@ -51,9 +52,14 @@ public abstract class ClassBuilder {
             @Nullable String signature,
             @Nullable Object value
     ) {
-        return getVisitor().visitField(access, name, desc, signature, value);
+        FieldVisitor visitor = getVisitor().visitField(access, name, desc, signature, value);
+        if (visitor == null) {
+            return EMPTY_FIELD_VISITOR;
+        }
+        return visitor;
     }
 
+    @NotNull
     public MethodVisitor newMethod(
             @Nullable PsiElement origin,
             int access,
@@ -62,7 +68,11 @@ public abstract class ClassBuilder {
             @Nullable String signature,
             @Nullable String[] exceptions
     ) {
-        return getVisitor().visitMethod(access, name, desc, signature, exceptions);
+        MethodVisitor visitor = getVisitor().visitMethod(access, name, desc, signature, exceptions);
+        if (visitor == null) {
+            return EMPTY_METHOD_VISITOR;
+        }
+        return visitor;
     }
 
     @NotNull
diff --git a/compiler/jet.as.java.psi/src/org/jetbrains/jet/asJava/StubClassBuilder.java b/compiler/jet.as.java.psi/src/org/jetbrains/jet/asJava/StubClassBuilder.java
index 28970cdde0f..6521db00964 100644
--- a/compiler/jet.as.java.psi/src/org/jetbrains/jet/asJava/StubClassBuilder.java
+++ b/compiler/jet.as.java.psi/src/org/jetbrains/jet/asJava/StubClassBuilder.java
@@ -96,6 +96,7 @@ public class StubClassBuilder extends ClassBuilder {
         ((StubBase) v.getResult()).putUserData(ClsWrapperStubPsiFactory.ORIGIN_ELEMENT, origin);
     }
 
+    @NotNull
     @Override
     public MethodVisitor newMethod(
             @Nullable PsiElement origin,
@@ -107,7 +108,7 @@ public class StubClassBuilder extends ClassBuilder {
     ) {
         MethodVisitor internalVisitor = super.newMethod(origin, access, name, desc, signature, exceptions);
 
-        if (internalVisitor != null) {
+        if (internalVisitor != EMPTY_METHOD_VISITOR) {
             // If stub for method generated
             markLastChild(origin);
         }
@@ -115,6 +116,7 @@ public class StubClassBuilder extends ClassBuilder {
         return internalVisitor;
     }
 
+    @NotNull
     @Override
     public FieldVisitor newField(
             @Nullable PsiElement origin,
@@ -126,7 +128,7 @@ public class StubClassBuilder extends ClassBuilder {
     ) {
         FieldVisitor internalVisitor = super.newField(origin, access, name, desc, signature, value);
 
-        if (internalVisitor != null) {
+        if (internalVisitor != EMPTY_FIELD_VISITOR) {
             // If stub for field generated
             markLastChild(origin);
         }