Generate static accessors fro protected functions in different packages

#KT-4617 Fixed

compiler/backend/src/org/jetbrains/jet/codegen/context/CodegenContext.java

@@ -39,6 +39,7 @@ import java.util.HashMap;
 import java.util.Map;
 
 import static org.jetbrains.asm4.Opcodes.ACC_PRIVATE;
+import static org.jetbrains.asm4.Opcodes.ACC_PROTECTED;
 import static org.jetbrains.jet.codegen.AsmUtil.CAPTURED_THIS_FIELD;
 import static org.jetbrains.jet.codegen.AsmUtil.getVisibilityAccessFlag;
 import static org.jetbrains.jet.codegen.binding.CodegenBinding.*;
@@ -405,8 +406,9 @@ public abstract class CodegenContext<T extends DeclarationDescriptor> {
 
     @NotNull
     private MemberDescriptor accessibleDescriptorIfNeeded(CallableMemberDescriptor descriptor, boolean fromOutsideContext) {
-        int flag = getAccessFlags(descriptor);
+        CallableMemberDescriptor unwrappedDescriptor = DescriptorUtils.unwrapFakeOverride(descriptor);
-        if ((flag & ACC_PRIVATE) == 0) {
+        int flag = getAccessFlags(unwrappedDescriptor);
+        if ((flag & ACC_PRIVATE) == 0 && (flag & ACC_PROTECTED) == 0) {
             return descriptor;
         }
 
@@ -438,7 +440,24 @@ public abstract class CodegenContext<T extends DeclarationDescriptor> {
             }
         }
 
-        return (MemberDescriptor) (descriptorContext != null ? descriptorContext.getAccessor(descriptor) : descriptor);
+        if (descriptorContext == null) {
+            return descriptor;
+        }
+
+        if ((flag & ACC_PROTECTED) != 0) {
+            PackageFragmentDescriptor unwrappedDescriptorPackage =
+                    DescriptorUtils.getParentOfType(unwrappedDescriptor, PackageFragmentDescriptor.class, false);
+            PackageFragmentDescriptor contextDescriptorPackage =
+                    DescriptorUtils.getParentOfType(descriptorContext.getContextDescriptor(), PackageFragmentDescriptor.class, false);
+
+            boolean inSamePackage = contextDescriptorPackage != null && unwrappedDescriptorPackage != null &&
+                                    unwrappedDescriptorPackage.getFqName().equals(contextDescriptorPackage.getFqName());
+            if (inSamePackage) {
+                return descriptor;
+            }
+        }
+
+        return (MemberDescriptor) descriptorContext.getAccessor(descriptor);
     }
 
     private void addChild(@NotNull CodegenContext child) {

compiler/testData/codegen/boxMultiFile/accessorForProtected/1.kt

@@ -0,0 +1,4 @@
+import b.B
+import a.BSamePackage
+
+fun box() = if (B().test() == BSamePackage().test()) "OK" else "fail"

compiler/testData/codegen/boxMultiFile/accessorForProtected/2.kt

@@ -0,0 +1,14 @@
+package a
+
+open class A {
+    protected fun protectedFun(): String = "OK"
+}
+
+class BSamePackage: A() {
+    fun test(): String {
+        val a = {
+            protectedFun()
+        }
+        return a()
+    }
+}

compiler/testData/codegen/boxMultiFile/accessorForProtected/3.kt

@@ -0,0 +1,12 @@
+package b
+
+import a.A
+
+class B: A() {
+    fun test(): String {
+        val a = {
+            protectedFun()
+        }
+        return a()
+    }
+}

compiler/testData/codegen/bytecodeText/accessorForProtected.kt

@@ -0,0 +1,16 @@
+package a
+
+open class A {
+    protected fun protectedFun(): String = "OK"
+}
+
+class BSamePackage: A() {
+    fun test(): String {
+        val a = {
+            protectedFun()
+        }
+        return a()
+    }
+}
+
+// 0 INVOKESTATIC a/BSamePackage.protectedFun

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

@@ -33,6 +33,11 @@ import org.jetbrains.jet.codegen.AbstractBytecodeTextTest;
 @TestMetadata("compiler/testData/codegen/bytecodeText")
 @InnerTestClasses({BytecodeTextTestGenerated.Constants.class, BytecodeTextTestGenerated.DirectInvoke.class, BytecodeTextTestGenerated.Statements.class})
 public class BytecodeTextTestGenerated extends AbstractBytecodeTextTest {
+    @TestMetadata("accessorForProtected.kt")
+    public void testAccessorForProtected() throws Exception {
+        doTest("compiler/testData/codegen/bytecodeText/accessorForProtected.kt");
+    }
+    
     public void testAllFilesPresentInBytecodeText() throws Exception {
         JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), "org.jetbrains.jet.generators.tests.TestsPackage", new File("compiler/testData/codegen/bytecodeText"), Pattern.compile("^(.+)\\.kt$"), true);
     }

compiler/tests/org/jetbrains/jet/codegen/generated/BlackBoxMultiFileCodegenTestGenerated.java

@@ -32,6 +32,11 @@ import org.jetbrains.jet.codegen.generated.AbstractBlackBoxCodegenTest;
 @SuppressWarnings("all")
 @TestMetadata("compiler/testData/codegen/boxMultiFile")
 public class BlackBoxMultiFileCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
+    @TestMetadata("accessorForProtected")
+    public void testAccessorForProtected() throws Exception {
+        doTestMultiFile("compiler/testData/codegen/boxMultiFile/accessorForProtected");
+    }
+    
     public void testAllFilesPresentInBoxMultiFile() throws Exception {
         JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), "org.jetbrains.jet.generators.tests.TestsPackage", new File("compiler/testData/codegen/boxMultiFile"), Pattern.compile("^([^\\.]+)$"), false);
     }