Merge remote-tracking branch 'origin/master'

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

@@ -0,0 +1,215 @@
+package org.jetbrains.jet.codegen;
+
+import org.jetbrains.annotations.Nullable;
+import org.jetbrains.jet.codegen.signature.JetSignatureWriter;
+import org.objectweb.asm.Type;
+import org.objectweb.asm.signature.SignatureVisitor;
+import org.objectweb.asm.signature.SignatureWriter;
+import org.objectweb.asm.util.CheckSignatureAdapter;
+
+import java.util.Stack;
+
+/**
+ * @author Stepan Koltsov
+ */
+public class BothSignatureWriter {
+
+    private static final boolean DEBUG_SIGNATURE_WRITER = true;
+
+    enum Mode {
+        METHOD(CheckSignatureAdapter.METHOD_SIGNATURE),
+        CLASS(CheckSignatureAdapter.CLASS_SIGNATURE),
+        ;
+        
+        private final int asmType;
+
+        Mode(int asmType) {
+            this.asmType = asmType;
+        }
+    }
+    
+    private final SignatureWriter signatureWriter = new SignatureWriter();
+    private final SignatureVisitor signatureVisitor;
+
+    private final JetSignatureWriter jetSignatureWriter = new JetSignatureWriter();
+
+    private final Mode mode;
+
+    public BothSignatureWriter(Mode mode) {
+        this.mode = mode;
+        if (DEBUG_SIGNATURE_WRITER) {
+            signatureVisitor = new CheckSignatureAdapter(mode.asmType, signatureWriter);
+        } else {
+            signatureVisitor = signatureWriter;
+        }
+    }
+
+    // TODO: ignore when debugging is disabled
+    private Stack<SignatureVisitor> visitors = new Stack<SignatureVisitor>();
+
+    private void push(SignatureVisitor visitor) {
+        visitors.push(visitor);
+    }
+
+    private void pop() {
+        visitors.pop();
+    }
+
+
+
+    private SignatureVisitor signatureVisitor() {
+        return !visitors.isEmpty() ? visitors.peek() : signatureVisitor;
+    }
+    
+    private void checkTopLevel() {
+        if (DEBUG_SIGNATURE_WRITER) {
+            if (!visitors.isEmpty()) {
+                throw new IllegalStateException();
+            }
+        }
+    }
+    
+    private void checkMode(Mode mode) {
+        if (DEBUG_SIGNATURE_WRITER) {
+            if (mode != this.mode) {
+                throw new IllegalStateException();
+            }
+        }
+    }
+
+
+    /**
+     * Shortcut
+     */
+    public void writeAsmType(Type asmType) {
+        switch (asmType.getSort()) {
+            case Type.OBJECT:
+                writeClassBegin(asmType.getInternalName());
+                writeClassEnd();
+                return;
+            case Type.ARRAY:
+                writeArrayType();
+                writeAsmType(asmType.getElementType());
+                writeArrayEnd();
+                return;
+            default:
+                String descriptor = asmType.getDescriptor();
+                if (descriptor.length() != 1) {
+                    throw new IllegalStateException();
+                }
+                signatureVisitor().visitBaseType(descriptor.charAt(0));
+        }
+    }
+    
+    public void writeClassBegin(String internalName) {
+        signatureVisitor().visitClassType(internalName);
+    }
+
+    public void writeClassEnd() {
+        signatureVisitor().visitEnd();
+    }
+
+    public void writeArrayType() {
+        push(signatureVisitor().visitArrayType());
+    }
+    
+    public void writeArrayEnd() {
+        pop();
+    }
+
+    public void writeTypeArgument(char c) {
+        push(signatureVisitor().visitTypeArgument(c));
+    }
+    
+    public void writeTypeArgumentEnd() {
+        pop();
+    }
+
+    public void writeTypeVariable(final String name) {
+        signatureVisitor().visitTypeVariable(name);
+    }
+    
+    public void writeFormalTypeParameter(final String name) {
+        checkTopLevel();
+
+        signatureVisitor().visitFormalTypeParameter(name);
+    }
+
+    public void writeClassBound() {
+        push(signatureVisitor().visitClassBound());
+    }
+    
+    public void writeClassBoundEnd() {
+        pop();
+    }
+
+    public void writeInterfaceBound() {
+        push(signatureVisitor().visitInterfaceBound());
+    }
+
+    public void writeInterfaceBoundEnd() {
+        pop();
+    }
+
+    public void writeParameterType() {
+        push(signatureVisitor().visitParameterType());
+    }
+    
+    public void writeParameterTypeEnd() {
+        pop();
+    }
+
+    public void writeReturnType() {
+        push(signatureVisitor().visitReturnType());
+    }
+    
+    public void writeReturnTypeEnd() {
+        pop();
+    }
+
+    public void writeSuperclass() {
+        checkTopLevel();
+        checkMode(Mode.CLASS);
+
+        push(signatureVisitor().visitSuperclass());
+    }
+    
+    public void writeSuperclassEnd() {
+        pop();
+        if (!visitors.isEmpty()) {
+            throw new IllegalStateException();
+        }
+    }
+
+    public void writeInterface() {
+        checkTopLevel();
+        checkMode(Mode.CLASS);
+
+        push(signatureVisitor().visitInterface());
+    }
+
+    public void writeInterfaceEnd() {
+        pop();
+        if (!visitors.isEmpty()) {
+            throw new IllegalStateException();
+        }
+    }
+
+
+
+
+    @Nullable
+    public String makeJavaString() {
+        if (!visitors.isEmpty()) {
+            throw new IllegalStateException();
+        }
+        return signatureWriter.toString();
+    }
+
+    @Nullable
+    public String makeKotlinString() {
+        // TODO: not implemented yet
+        return null;
+    }
+
+}

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

@@ -57,26 +57,18 @@ public class CodegenUtil {
         return (ClassDescriptor) outerDescriptor;
     }
 
-    public static boolean hasOuterTypeInfo(ClassDescriptor descriptor) {
-        ClassDescriptor outerClassDescriptor = getOuterClassDescriptor(descriptor);
-        if(outerClassDescriptor == null)
-            return false;
-
-        if(outerClassDescriptor.getTypeConstructor().getParameters().size() > 0)
-            return true;
-
-        return hasOuterTypeInfo(outerClassDescriptor);
-    }
-
-    public static boolean hasDerivedTypeInfoField(JetType type, boolean exceptOwn) {
-        if(!exceptOwn) {
-            if(!isInterface(type))
-                if(hasTypeInfoField(type))
-                    return true;
+    public static boolean hasDerivedTypeInfoField(JetType type) {
+        for (JetType jetType : type.getConstructor().getSupertypes()) {
+            if(hasTypeInfoField(jetType))
+                return true;
         }
 
-        for (JetType jetType : type.getConstructor().getSupertypes()) {
-            if(hasDerivedTypeInfoField(jetType, false))
+        return false;
+    }
+
+    public static boolean requireTypeInfoConstructorArg(JetType type) {
+        for (TypeParameterDescriptor parameter : type.getConstructor().getParameters()) {
+            if(parameter.isReified())
                 return true;
         }
 
@@ -87,22 +79,10 @@ public class CodegenUtil {
         if(isInterface(type))
             return false;
 
-        List<TypeParameterDescriptor> parameters = type.getConstructor().getParameters();
-        for (TypeParameterDescriptor parameter : parameters) {
-            if(parameter.isReified())
-                return true;
-        }
+        if(requireTypeInfoConstructorArg(type))
+            return true;
 
-        for (JetType jetType : type.getConstructor().getSupertypes()) {
-            if(hasTypeInfoField(jetType))
-                return true;
-        }
-
-        ClassDescriptor outerClassDescriptor = getOuterClassDescriptor(type.getConstructor().getDeclarationDescriptor());
-        if(outerClassDescriptor == null || isClassObject(type.getConstructor().getDeclarationDescriptor()))
-            return false;
-
-        return hasTypeInfoField(outerClassDescriptor.getDefaultType());
+        return hasDerivedTypeInfoField(type);
     }
 
     public static FunctionDescriptor createInvoke(ExpressionAsFunctionDescriptor fd) {

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

@@ -12,11 +12,11 @@ import java.util.List;
 
 /**
  * @author yole
+ * @author alex.tkachman
  */
 public class ConstructorFrameMap extends FrameMap {
     private int myOuterThisIndex = -1;
-    private int myFirstTypeParameter = -1;
-    private int myTypeParameterCount = 0;
+    private int myTypeInfoIndex  = -1;
 
     public ConstructorFrameMap(CallableMethod callableMethod, @Nullable ConstructorDescriptor descriptor, ClassDescriptor classDescriptor, OwnerKind kind) {
         enterTemp(); // this
@@ -27,15 +27,8 @@ public class ConstructorFrameMap extends FrameMap {
         }
 
         if (classDescriptor != null) {
-            List<TypeParameterDescriptor> parameters = classDescriptor.getTypeConstructor().getParameters();
-            for (TypeParameterDescriptor parameter : parameters) {
-                if(parameter.isReified()) {
-                    int index = enterTemp();
-                    myTypeParameterCount++;
-                    if(myFirstTypeParameter == -1) {
-                        myFirstTypeParameter = index;
-                    }
-                }
+            if (CodegenUtil.requireTypeInfoConstructorArg(classDescriptor.getDefaultType())) {
+                myTypeInfoIndex = enterTemp();
             }
         }
 
@@ -54,11 +47,7 @@ public class ConstructorFrameMap extends FrameMap {
         return myOuterThisIndex;
     }
 
-    public int getFirstTypeParameter() {
-        return myFirstTypeParameter;
-    }
-
-    public int getTypeParameterCount() {
-        return myTypeParameterCount;
+    public int getTypeInfoIndex() {
+        return myTypeInfoIndex;
     }
 }

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

@@ -979,7 +979,7 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> {
         }
         else if (descriptor instanceof TypeParameterDescriptor) {
             TypeParameterDescriptor typeParameterDescriptor = (TypeParameterDescriptor) descriptor;
-            loadTypeParameterTypeInfo(typeParameterDescriptor);
+            loadTypeParameterTypeInfo(typeParameterDescriptor, null);
             v.invokevirtual("jet/typeinfo/TypeInfo", "getClassObject", "()Ljava/lang/Object;");
             v.checkcast(asmType(typeParameterDescriptor.getClassObjectType()));
 
@@ -2033,26 +2033,32 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> {
 
     private void pushTypeArguments(ResolvedCall<? extends CallableDescriptor> resolvedCall) {
         if(resolvedCall != null) {
-            Map<TypeParameterDescriptor, JetType> typeArguments = resolvedCall.getTypeArguments();
-            CallableDescriptor resultingDescriptor = resolvedCall.getCandidateDescriptor();
-            for (TypeParameterDescriptor typeParameterDescriptor : resultingDescriptor.getTypeParameters()) {
-                if(typeParameterDescriptor.isReified()) {
-                    JetType jetType = typeArguments.get(typeParameterDescriptor);
-                    generateTypeInfo(jetType);
+            if(resolvedCall.getResultingDescriptor() instanceof ConstructorDescriptor) {
+                ConstructorDescriptor constructorDescriptor = (ConstructorDescriptor) resolvedCall.getResultingDescriptor();
+                ClassDescriptor containingDeclaration = constructorDescriptor.getContainingDeclaration();
+                if(CodegenUtil.requireTypeInfoConstructorArg(containingDeclaration.getDefaultType())) {
+                    generateTypeInfo(containingDeclaration.getDefaultType(), resolvedCall.getTypeArguments());
+                }
+            }
+            else {
+                Map<TypeParameterDescriptor, JetType> typeArguments = resolvedCall.getTypeArguments();
+                CallableDescriptor resultingDescriptor = resolvedCall.getCandidateDescriptor();
+                for (TypeParameterDescriptor typeParameterDescriptor : resultingDescriptor.getTypeParameters()) {
+                    if(typeParameterDescriptor.isReified()) {
+                        JetType jetType = typeArguments.get(typeParameterDescriptor);
+                        generateTypeInfo(jetType, typeArguments);
+                    }
                 }
             }
         }
         else {
             throw new UnsupportedOperationException();
-//            for (JetTypeProjection jetTypeArgument : expression.getTypeArguments()) {
-//                pushTypeArgument(jetTypeArgument);
-//            }
         }
     }
 
     public void pushTypeArgument(JetTypeProjection jetTypeArgument) {
         JetType typeArgument = bindingContext.get(BindingContext.TYPE, jetTypeArgument.getTypeReference());
-        generateTypeInfo(typeArgument);
+        generateTypeInfo(typeArgument, null);
     }
 
     private Type generateJavaConstructorCall(JetCallExpression expression) {
@@ -2091,7 +2097,7 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> {
         if(isArray) {
             JetType elementType = typeMapper.getGenericsElementType(arrayType);
             if(elementType != null) {
-                generateTypeInfo(elementType);
+                generateTypeInfo(elementType, null);
                 gen(args.get(0).getArgumentExpression(), Type.INT_TYPE);
                 v.invokevirtual("jet/typeinfo/TypeInfo", "newArray", "(I)[Ljava/lang/Object;");
             }
@@ -2193,9 +2199,9 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> {
                 if(getterDescriptor.getReceiverParameter().exists()) {
                     index++;
                 }
-                for (TypeParameterDescriptor typeParameterDescriptor : getterDescriptor.getTypeParameters()) {
+                for (TypeParameterDescriptor typeParameterDescriptor : resolvedGetCall.getCandidateDescriptor().getTypeParameters()) {
                     if(typeParameterDescriptor.isReified()) {
-                        generateTypeInfo(resolvedGetCall.getTypeArguments().get(typeParameterDescriptor));
+                        generateTypeInfo(resolvedGetCall.getTypeArguments().get(typeParameterDescriptor), null);
                         index++;
                     }
                 }
@@ -2215,7 +2221,7 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> {
                 }
                 for (TypeParameterDescriptor typeParameterDescriptor : setterDescriptor.getOriginal().getTypeParameters()) {
                     if(typeParameterDescriptor.isReified()) {
-                        generateTypeInfo(resolvedSetCall.getTypeArguments().get(typeParameterDescriptor));
+                        generateTypeInfo(resolvedSetCall.getTypeArguments().get(typeParameterDescriptor), null);
                         index++;
                     }
                 }
@@ -2503,7 +2509,7 @@ If finally block is present, its last expression is the value of try expression.
             }
         }
         else {
-            generateTypeInfo(jetType);
+            generateTypeInfo(jetType, null);
             expressionToGen.put(TYPE_OBJECT, v);
             if (leaveExpressionOnStack) {
                 v.dupX1();
@@ -2512,7 +2518,7 @@ If finally block is present, its last expression is the value of try expression.
         }
     }
 
-    public void generateTypeInfo(JetType jetType) {
+    public void generateTypeInfo(JetType jetType, Map<TypeParameterDescriptor, JetType> typeArguments) {
         String knownTypeInfo = typeMapper.isKnownTypeInfo(jetType);
         if(knownTypeInfo != null) {
             v.getstatic("jet/typeinfo/TypeInfo", knownTypeInfo, "Ljet/typeinfo/TypeInfo;");
@@ -2521,7 +2527,7 @@ If finally block is present, its last expression is the value of try expression.
 
         DeclarationDescriptor declarationDescriptor = jetType.getConstructor().getDeclarationDescriptor();
         if (declarationDescriptor instanceof TypeParameterDescriptor) {
-            loadTypeParameterTypeInfo((TypeParameterDescriptor) declarationDescriptor);
+            loadTypeParameterTypeInfo((TypeParameterDescriptor) declarationDescriptor, typeArguments);
             return;
         }
 
@@ -2551,7 +2557,7 @@ If finally block is present, its last expression is the value of try expression.
                 TypeProjection argument = arguments.get(i);
                 v.dup();
                 v.iconst(i);
-                generateTypeInfo(argument.getType());
+                generateTypeInfo(argument.getType(), typeArguments);
                 genTypeInfoToProjection(v, argument.getProjectionKind());
                 v.astore(TYPE_OBJECT);
             }
@@ -2573,12 +2579,21 @@ If finally block is present, its last expression is the value of try expression.
             throw new UnsupportedOperationException(variance.toString());
     }
 
-    private void loadTypeParameterTypeInfo(TypeParameterDescriptor typeParameterDescriptor) {
+    private void loadTypeParameterTypeInfo(TypeParameterDescriptor typeParameterDescriptor, @Nullable Map<TypeParameterDescriptor, JetType> typeArguments) {
         final StackValue value = typeParameterExpressions.get(typeParameterDescriptor);
         if (value != null) {
             value.put(TYPE_TYPEINFO, v);
             return;
         }
+        
+        if(typeArguments != null) {
+            JetType jetType = typeArguments.get(typeParameterDescriptor);
+            if(jetType != null && !jetType.equals(typeParameterDescriptor.getDefaultType())) {
+                generateTypeInfo(jetType, typeArguments);
+                return;
+            }
+        }
+        
         DeclarationDescriptor containingDeclaration = typeParameterDescriptor.getContainingDeclaration();
         if (context.getThisDescriptor() != null) {
             ClassDescriptor descriptor = context.getThisDescriptor();
@@ -2589,8 +2604,13 @@ If finally block is present, its last expression is the value of try expression.
             if (containingDeclaration == context.getThisDescriptor()) {
                 if(!CodegenUtil.isInterface(descriptor)) {
                     if (CodegenUtil.hasTypeInfoField(defaultType)) {
-                        v.load(0, TYPE_OBJECT);
-                        v.getfield(ownerType.getInternalName(), "$typeInfo", "Ljet/typeinfo/TypeInfo;");
+                        if(!(context instanceof CodegenContext.ConstructorContext)) {
+                            v.load(0, TYPE_OBJECT);
+                            v.getfield(ownerType.getInternalName(), "$typeInfo", "Ljet/typeinfo/TypeInfo;");
+                        }
+                        else {
+                            v.load(((ConstructorFrameMap)myFrameMap).getTypeInfoIndex(), TYPE_OBJECT);
+                        }
                     }
                     else {
                         v.getstatic(ownerType.getInternalName(), "$typeInfo", "Ljet/typeinfo/TypeInfo;");
@@ -2598,16 +2618,16 @@ If finally block is present, its last expression is the value of try expression.
                 }
                 else {
                     v.load(0, TYPE_OBJECT);
-                    v.invokeinterface("jet/JetObject", "getTypeInfo", "()Ljet/typeinfo/TypeInfo;");
+                    v.invokeinterface(TYPE_JET_OBJECT.getInternalName(), "getTypeInfo", "()Ljet/typeinfo/TypeInfo;");
                 }
             }
             else {
                 v.load(0, TYPE_OBJECT);
-                v.invokeinterface("jet/JetObject", "getTypeInfo", "()Ljet/typeinfo/TypeInfo;");
                 while(descriptor != containingDeclaration) {
                     descriptor = CodegenUtil.getOuterClassDescriptor(descriptor);
-                    v.invokevirtual("jet/typeinfo/TypeInfo", "getOuterTypeInfo", "()Ljet/typeinfo/TypeInfo;");
+                    v.invokeinterface(TYPE_JET_OBJECT.getInternalName(), "getOuterObject", "()Ljet/JetObject;");
                 }
+                v.invokeinterface(TYPE_JET_OBJECT.getInternalName(), "getTypeInfo", "()Ljet/typeinfo/TypeInfo;");
             }
             v.aconst(ownerType);
             v.iconst(typeParameterDescriptor.getIndex());
@@ -2737,7 +2757,7 @@ If finally block is present, its last expression is the value of try expression.
 
         v.anew(tupleType);
         v.dup();
-        generateTypeInfo(new ProjectionErasingJetType(bindingContext.get(BindingContext.EXPRESSION_TYPE, expression)));
+        generateTypeInfo(new ProjectionErasingJetType(bindingContext.get(BindingContext.EXPRESSION_TYPE, expression)), null);
         for (JetExpression entry : entries) {
             gen(entry, TYPE_OBJECT);
         }

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

@@ -6,7 +6,7 @@ import org.jetbrains.jet.lang.descriptors.*;
 import org.jetbrains.jet.lang.psi.*;
 import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.lang.resolve.DescriptorUtils;
-import org.jetbrains.jet.lang.resolve.StdlibNames;
+import org.jetbrains.jet.lang.resolve.java.StdlibNames;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverDescriptor;
 import org.objectweb.asm.AnnotationVisitor;
 import org.objectweb.asm.Label;
@@ -86,7 +86,7 @@ public class FunctionCodegen {
             if(v.generateCode()) {
                 int start = 0;
                 if(kind != OwnerKind.TRAIT_IMPL) {
-                    AnnotationVisitor av = mv.visitAnnotation(StdlibNames.JET_METHOD_TYPE.getDescriptor(), true);
+                    AnnotationVisitor av = mv.visitAnnotation(JetTypeMapper.JET_METHOD_TYPE.getDescriptor(), true);
                     if(functionDescriptor.getReturnType().isNullable()) {
                         av.visit(StdlibNames.JET_METHOD_NULLABLE_RETURN_TYPE_FIELD, true);
                     }
@@ -94,15 +94,15 @@ public class FunctionCodegen {
                 }
 
                 if(kind == OwnerKind.TRAIT_IMPL) {
-                    AnnotationVisitor av = mv.visitParameterAnnotation(start++, StdlibNames.JET_PARAMETER_DESCRIPTOR, true);
-                    av.visit(StdlibNames.JET_PARAMETER_NAME_FIELD, "this$self");
+                    AnnotationVisitor av = mv.visitParameterAnnotation(start++, StdlibNames.JET_VALUE_PARAMETER_DESCRIPTOR, true);
+                    av.visit(StdlibNames.JET_VALUE_PARAMETER_NAME_FIELD, "this$self");
                     av.visitEnd();
                 }
                 if(receiverParameter.exists()) {
-                    AnnotationVisitor av = mv.visitParameterAnnotation(start++, StdlibNames.JET_PARAMETER_DESCRIPTOR, true);
-                    av.visit(StdlibNames.JET_PARAMETER_NAME_FIELD, "this$receiver");
+                    AnnotationVisitor av = mv.visitParameterAnnotation(start++, StdlibNames.JET_VALUE_PARAMETER_DESCRIPTOR, true);
+                    av.visit(StdlibNames.JET_VALUE_PARAMETER_NAME_FIELD, "this$receiver");
                     if(receiverParameter.getType().isNullable()) {
-                        av.visit(StdlibNames.JET_PARAMETER_NULLABLE_FIELD, true);
+                        av.visit(StdlibNames.JET_VALUE_PARAMETER_NULLABLE_FIELD, true);
                     }
                     av.visitEnd();
                 }
@@ -112,14 +112,14 @@ public class FunctionCodegen {
                     av.visitEnd();
                 }
                 for(int i = 0; i != paramDescrs.size(); ++i) {
-                    AnnotationVisitor av = mv.visitParameterAnnotation(i + start, StdlibNames.JET_PARAMETER_DESCRIPTOR, true);
+                    AnnotationVisitor av = mv.visitParameterAnnotation(i + start, StdlibNames.JET_VALUE_PARAMETER_DESCRIPTOR, true);
                     ValueParameterDescriptor parameterDescriptor = paramDescrs.get(i);
-                    av.visit(StdlibNames.JET_PARAMETER_NAME_FIELD, parameterDescriptor.getName());
+                    av.visit(StdlibNames.JET_VALUE_PARAMETER_NAME_FIELD, parameterDescriptor.getName());
                     if(parameterDescriptor.hasDefaultValue()) {
-                        av.visit(StdlibNames.JET_PARAMETER_HAS_DEFAULT_VALUE_FIELD, true);
+                        av.visit(StdlibNames.JET_VALUE_PARAMETER_HAS_DEFAULT_VALUE_FIELD, true);
                     }
                     if(parameterDescriptor.getOutType().isNullable()) {
-                        av.visit(StdlibNames.JET_PARAMETER_NULLABLE_FIELD, true);
+                        av.visit(StdlibNames.JET_VALUE_PARAMETER_NULLABLE_FIELD, true);
                     }
                     av.visitEnd();
                 }

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

@@ -6,6 +6,7 @@ import org.jetbrains.jet.lang.descriptors.*;
 import org.jetbrains.jet.lang.psi.*;
 import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.lang.resolve.OverridingUtil;
+import org.jetbrains.jet.lang.resolve.java.StdlibNames;
 import org.jetbrains.jet.lang.resolve.constants.CompileTimeConstant;
 import org.jetbrains.jet.lang.types.JetType;
 import org.jetbrains.jet.lang.types.TypeProjection;
@@ -16,9 +17,6 @@ import org.objectweb.asm.Opcodes;
 import org.objectweb.asm.Type;
 import org.objectweb.asm.commons.InstructionAdapter;
 import org.objectweb.asm.commons.Method;
-import org.objectweb.asm.signature.SignatureVisitor;
-import org.objectweb.asm.signature.SignatureWriter;
-import org.objectweb.asm.util.CheckSignatureAdapter;
 
 import java.util.*;
 
@@ -29,7 +27,9 @@ import java.util.*;
  */
 public class ImplementationBodyCodegen extends ClassBodyCodegen {
     private JetDelegationSpecifier superCall;
-    private String superClass = "java/lang/Object";
+    private String superClass;
+    @Nullable // null means java/lang/Object
+    private JetType superClassType;
     private final JetTypeMapper typeMapper;
     private final BindingContext bindingContext;
 
@@ -39,28 +39,11 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
         bindingContext = state.getBindingContext();
     }
 
-    private Set<String> getSuperInterfaces(JetClassOrObject aClass) {
-        List<JetDelegationSpecifier> delegationSpecifiers = aClass.getDelegationSpecifiers();
-        Set<String> superInterfaces = new LinkedHashSet<String>();
-
-        for (JetDelegationSpecifier specifier : delegationSpecifiers) {
-            JetType superType = bindingContext.get(BindingContext.TYPE, specifier.getTypeReference());
-            assert superType != null;
-            ClassDescriptor superClassDescriptor = (ClassDescriptor) superType.getConstructor().getDeclarationDescriptor();
-            if(CodegenUtil.isInterface(superClassDescriptor)) {
-                superInterfaces.add(typeMapper.getFQName(superClassDescriptor));
-            }
-        }
-        return superInterfaces;
-    }
-
     @Override
     protected void generateDeclaration() {
         getSuperClass();
 
-        List<String> interfaces = new ArrayList<String>();
-        interfaces.add("jet/JetObject");
-        interfaces.addAll(getSuperInterfaces(myClass));
+        JvmClassSignature signature = signature();
 
         boolean isAbstract = false;
         boolean isInterface = false;
@@ -77,10 +60,10 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
                       Opcodes.ACC_PUBLIC | (isAbstract ? Opcodes.ACC_ABSTRACT : 0) | (isInterface
                                                                                       ? Opcodes.ACC_INTERFACE
                                                                                       : 0/*Opcodes.ACC_SUPER*/),
-                      jvmName(),
-                      genericSignature(),
-                      superClass,
-                      interfaces.toArray(new String[interfaces.size()])
+                      signature.getName(),
+                      signature.getGenericSignature(),
+                      signature.getSuperclassName(),
+                      signature.getInterfaces().toArray(new String[0])
         );
         v.visitSource(myClass.getContainingFile().getName(), null);
 
@@ -94,30 +77,57 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
             annotationVisitor.visitEnd();
         }
     }
+    
+    private JvmClassSignature signature() {
+        String genericSignature;
+        List<String> superInterfaces;
 
-    @Nullable
-    private String genericSignature() {
-        List<TypeParameterDescriptor> typeParameters = descriptor.getTypeConstructor().getParameters();
-        
-        SignatureWriter signatureWriter = new SignatureWriter();
-        SignatureVisitor signatureVisitor = JetTypeMapper.DEBUG_SIGNATURE_WRITER
-                ? new CheckSignatureAdapter(CheckSignatureAdapter.CLASS_SIGNATURE, signatureWriter)
-                : signatureWriter;
-        for (TypeParameterDescriptor typeParameter : typeParameters) {
-            signatureVisitor.visitFormalTypeParameter(typeParameter.getName());
-            SignatureVisitor classBoundVisitor = signatureVisitor.visitClassBound();
-            // TODO: wrong
-            JetTypeMapper.visitAsmType(classBoundVisitor, JetTypeMapper.TYPE_OBJECT);
+        {
+            LinkedHashSet<String> superInterfacesLinkedHashSet = new LinkedHashSet<String>();
+
+            BothSignatureWriter signatureVisitor = new BothSignatureWriter(BothSignatureWriter.Mode.CLASS);
+
+
+            {   // type parameters
+                List<TypeParameterDescriptor> typeParameters = descriptor.getTypeConstructor().getParameters();
+                typeMapper.writeFormalTypeParameters(typeParameters, signatureVisitor);
+            }
+
+
+            {   // superclass
+                signatureVisitor.writeSuperclass();
+                if (superClassType == null) {
+                    signatureVisitor.writeClassBegin(superClass);
+                    signatureVisitor.writeClassEnd();
+                } else {
+                    typeMapper.mapType(superClassType, OwnerKind.IMPLEMENTATION, signatureVisitor, true);
+                }
+                signatureVisitor.writeSuperclassEnd();
+            }
+
+
+            {   // superinterfaces
+                superInterfacesLinkedHashSet.add(StdlibNames.JET_OBJECT_INTERNAL);
+
+                for (JetDelegationSpecifier specifier : myClass.getDelegationSpecifiers()) {
+                    JetType superType = bindingContext.get(BindingContext.TYPE, specifier.getTypeReference());
+                    assert superType != null;
+                    ClassDescriptor superClassDescriptor = (ClassDescriptor) superType.getConstructor().getDeclarationDescriptor();
+                    if (CodegenUtil.isInterface(superClassDescriptor)) {
+                        signatureVisitor.writeInterface();
+                        Type jvmName = typeMapper.mapType(superType, OwnerKind.IMPLEMENTATION, signatureVisitor, true);
+                        signatureVisitor.writeInterfaceEnd();
+                        superInterfacesLinkedHashSet.add(jvmName.getInternalName());
+                    }
+                }
+
+                superInterfaces = new ArrayList<String>(superInterfacesLinkedHashSet);
+            }
+
+            // TODO: null if class is not generic and does not have generic superclasses
+            genericSignature = signatureVisitor.makeJavaString();
         }
-        SignatureVisitor superclassSignatureVisitor = signatureVisitor.visitSuperclass();
-        // TODO: wrong
-        superclassSignatureVisitor.visitClassType("java/lang/Object");
-        // TODO: add interfaces
-        superclassSignatureVisitor.visitEnd();
-
-        // TODO: return null if class is not generic and does not have generic superclasses
-
-        return signatureWriter.toString();
+        return new JvmClassSignature(jvmName(), superClass, superInterfaces, genericSignature);
     }
 
     private String jvmName() {
@@ -125,6 +135,9 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
     }
 
     protected void getSuperClass() {
+        superClass = "java/lang/Object";
+        superClassType = null;
+
         List<JetDelegationSpecifier> delegationSpecifiers = myClass.getDelegationSpecifiers();
 
         if(myClass instanceof JetClass && ((JetClass) myClass).isTrait())
@@ -136,6 +149,7 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
                 assert superType != null;
                 ClassDescriptor superClassDescriptor = (ClassDescriptor) superType.getConstructor().getDeclarationDescriptor();
                 if(!CodegenUtil.isInterface(superClassDescriptor)) {
+                    superClassType = superType;
                     superClass = typeMapper.mapType(superClassDescriptor.getDefaultType(), kind).getInternalName();
                     superCall = specifier;
                 }
@@ -305,8 +319,7 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
                 parameterTypes.add(typeMapper.mapType(CodegenUtil.getOuterClassDescriptor(descriptor).getDefaultType(), OwnerKind.IMPLEMENTATION));
             }
 
-            List<TypeParameterDescriptor> typeParameters = descriptor.getTypeConstructor().getParameters();
-            for (int n = typeParameters.size(); n > 0; n--) {
+            if (CodegenUtil.requireTypeInfoConstructorArg(descriptor.getDefaultType())) {
                 parameterTypes.add(JetTypeMapper.TYPE_TYPEINFO);
             }
 
@@ -365,12 +378,12 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
         final InstructionAdapter iv = new InstructionAdapter(mv);
         ExpressionCodegen codegen = new ExpressionCodegen(mv, frameMap, Type.VOID_TYPE, constructorContext, state);
 
-        for(int slot = 0; slot != frameMap.getTypeParameterCount(); ++slot) {
-            if(constructorDescriptor != null)
-                codegen.addTypeParameter(constructorDescriptor.getTypeParameters().get(slot), StackValue.local(frameMap.getFirstTypeParameter() + slot, JetTypeMapper.TYPE_TYPEINFO));
-            else
-                codegen.addTypeParameter(descriptor.getTypeConstructor().getParameters().get(slot), StackValue.local(frameMap.getFirstTypeParameter() + slot, JetTypeMapper.TYPE_TYPEINFO));
-        }
+//        for(int slot = 0; slot != frameMap.getTypeParameterCount(); ++slot) {
+//            if(constructorDescriptor != null)
+//                codegen.addTypeParameter(constructorDescriptor.getTypeParameters().get(slot), StackValue.local(frameMap.getFirstTypeParameter() + slot, JetTypeMapper.TYPE_TYPEINFO));
+//            else
+//                codegen.addTypeParameter(descriptor.getTypeConstructor().getParameters().get(slot), StackValue.local(frameMap.getFirstTypeParameter() + slot, JetTypeMapper.TYPE_TYPEINFO));
+//        }
 
         String classname = typeMapper.mapType(descriptor.getDefaultType(), kind).getInternalName();
         final Type classType = Type.getType("L" + classname + ";");
@@ -399,7 +412,7 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
                     parameterTypes.add(typeMapper.mapType(CodegenUtil.getOuterClassDescriptor(descriptor).getDefaultType(), OwnerKind.IMPLEMENTATION));
                 }
                 for(TypeProjection typeParameterDescriptor : superType.getArguments()) {
-                    codegen.generateTypeInfo(typeParameterDescriptor.getType());
+                    codegen.generateTypeInfo(typeParameterDescriptor.getType(), null);
                     parameterTypes.add(JetTypeMapper.TYPE_TYPEINFO);
                 }
                 Method superCallMethod = new Method("<init>", Type.VOID_TYPE, parameterTypes.toArray(new Type[parameterTypes.size()]));
@@ -447,10 +460,21 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
             iv.load(0, classType);
             iv.load(frameMap.getOuterThisIndex(), type);
             iv.putfield(classname, fieldName, interfaceDesc);
+
+            Type outerType = typeMapper.mapType(outerDescriptor.getDefaultType());
+            MethodVisitor outer = v.newMethod(myClass, Opcodes.ACC_PUBLIC, "getOuterObject", "()Ljet/JetObject;", null, null);
+            outer.visitCode();
+            outer.visitVarInsn(Opcodes.ALOAD, 0);
+            outer.visitFieldInsn(Opcodes.GETFIELD, classname, "this$0", outerType.getDescriptor());
+            outer.visitInsn(Opcodes.ARETURN);
+            outer.visitMaxs(0, 0);
+            outer.visitEnd();
         }
 
-        if (CodegenUtil.hasTypeInfoField(descriptor.getDefaultType()) && kind == OwnerKind.IMPLEMENTATION) {
-            generateTypeInfoInitializer(frameMap.getFirstTypeParameter(), frameMap.getTypeParameterCount(), iv);
+        if (CodegenUtil.requireTypeInfoConstructorArg(descriptor.getDefaultType()) && kind == OwnerKind.IMPLEMENTATION) {
+            iv.load(0, JetTypeMapper.TYPE_OBJECT);
+            iv.load(frameMap.getTypeInfoIndex(), JetTypeMapper.TYPE_OBJECT);
+            iv.invokevirtual(typeMapper.mapType(descriptor.getDefaultType(), OwnerKind.IMPLEMENTATION).getInternalName(), "$setTypeInfo", "(Ljet/typeinfo/TypeInfo;)V");
         }
 
         if(closure != null) {
@@ -691,46 +715,6 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
         }
     }
 
-    protected void generateTypeInfoInitializer(int firstTypeParameter, int typeParamCount, InstructionAdapter iv) {
-        iv.load(0, JetTypeMapper.TYPE_OBJECT);
-
-        iv.aconst(typeMapper.mapType(descriptor.getDefaultType(), OwnerKind.IMPLEMENTATION));
-        iv.iconst(0);
-
-        if(CodegenUtil.hasOuterTypeInfo(descriptor)) {
-            iv.load(1, JetTypeMapper.TYPE_OBJECT);
-            iv.invokeinterface("jet/JetObject", "getTypeInfo", "()Ljet/typeinfo/TypeInfo;");
-        }
-
-        if(typeParamCount != 0) {
-            iv.iconst(typeParamCount);
-            iv.newarray(JetTypeMapper.TYPE_TYPEINFOPROJECTION);
-
-            for (int i = 0; i < typeParamCount; i++) {
-                iv.dup();
-                iv.iconst(i);
-                iv.load(firstTypeParameter + i, JetTypeMapper.TYPE_OBJECT);
-                iv.checkcast(JetTypeMapper.TYPE_TYPEINFOPROJECTION);
-                iv.astore(JetTypeMapper.TYPE_OBJECT);
-            }
-
-            if(CodegenUtil.hasOuterTypeInfo(descriptor)) {
-                iv.invokestatic("jet/typeinfo/TypeInfo", "getTypeInfo", "(Ljava/lang/Class;ZLjet/typeinfo/TypeInfo;[Ljet/typeinfo/TypeInfoProjection;)Ljet/typeinfo/TypeInfo;");
-            }
-            else
-                iv.invokestatic("jet/typeinfo/TypeInfo", "getTypeInfo", "(Ljava/lang/Class;Z[Ljet/typeinfo/TypeInfoProjection;)Ljet/typeinfo/TypeInfo;");
-        }
-        else {
-            if(CodegenUtil.hasOuterTypeInfo(descriptor)) {
-                iv.invokestatic("jet/typeinfo/TypeInfo", "getTypeInfo", "(Ljava/lang/Class;ZLjet/typeinfo/TypeInfo;)Ljet/typeinfo/TypeInfo;");
-            }
-            else
-                iv.invokestatic("jet/typeinfo/TypeInfo", "getTypeInfo", "(Ljava/lang/Class;Z)Ljet/typeinfo/TypeInfo;");
-        }
-
-        iv.invokevirtual(typeMapper.mapType(descriptor.getDefaultType(), OwnerKind.IMPLEMENTATION).getInternalName(), "$setTypeInfo", "(Ljet/typeinfo/TypeInfo;)V");
-    }
-
     protected void generateInitializers(ExpressionCodegen codegen, InstructionAdapter iv) {
         for (JetDeclaration declaration : myClass.getDeclarations()) {
             if (declaration instanceof JetProperty) {
@@ -827,15 +811,14 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
             return;
 
         JetType defaultType = descriptor.getDefaultType();
-        if(CodegenUtil.hasTypeInfoField(defaultType)) {
-            if(!CodegenUtil.hasDerivedTypeInfoField(defaultType, true)) {
+        if(CodegenUtil.requireTypeInfoConstructorArg(defaultType)) {
+            if(!CodegenUtil.hasDerivedTypeInfoField(defaultType)) {
                 v.newField(myClass, Opcodes.ACC_PROTECTED, "$typeInfo", "Ljet/typeinfo/TypeInfo;", null, null);
 
                 MethodVisitor mv = v.newMethod(myClass, Opcodes.ACC_PUBLIC, "getTypeInfo", "()Ljet/typeinfo/TypeInfo;", null, null);
-                InstructionAdapter iv = null;
                 if (v.generateCode()) {
                     mv.visitCode();
-                    iv = new InstructionAdapter(mv);
+                    InstructionAdapter iv = new InstructionAdapter(mv);
                     String owner = typeMapper.mapType(descriptor.getDefaultType(), OwnerKind.IMPLEMENTATION).getInternalName();
                     iv.load(0, JetTypeMapper.TYPE_OBJECT);
                     iv.getfield(owner, "$typeInfo", "Ljet/typeinfo/TypeInfo;");
@@ -847,7 +830,7 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
                 mv = v.newMethod(myClass, Opcodes.ACC_PROTECTED | Opcodes.ACC_FINAL, "$setTypeInfo", "(Ljet/typeinfo/TypeInfo;)V", null, null);
                 if (v.generateCode()) {
                     mv.visitCode();
-                    iv = new InstructionAdapter(mv);
+                    InstructionAdapter iv = new InstructionAdapter(mv);
                     String owner = typeMapper.mapType(descriptor.getDefaultType(), OwnerKind.IMPLEMENTATION).getInternalName();
                     iv.load(0, JetTypeMapper.TYPE_OBJECT);
                     iv.load(1, JetTypeMapper.TYPE_OBJECT);
@@ -884,14 +867,7 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
             public void generate(InstructionAdapter v) {
                 v.aconst(typeMapper.mapType(descriptor.getDefaultType(), OwnerKind.IMPLEMENTATION));
                 v.iconst(0);
-                ClassDescriptor outerClassDescriptor = CodegenUtil.getOuterClassDescriptor(descriptor);
-                if(outerClassDescriptor == null || CodegenUtil.isClassObject(descriptor)) {
-                    v.invokestatic("jet/typeinfo/TypeInfo", "getTypeInfo", "(Ljava/lang/Class;Z)Ljet/typeinfo/TypeInfo;");
-                }
-                else {
-                    v.getstatic(typeMapper.mapType(outerClassDescriptor.getDefaultType(), OwnerKind.IMPLEMENTATION).getInternalName(), "$staticTypeInfo", "Ljet/typeinfo/TypeInfo;");
-                    v.invokestatic("jet/typeinfo/TypeInfo", "getTypeInfo", "(Ljava/lang/Class;ZLjet/typeinfo/TypeInfo;)Ljet/typeinfo/TypeInfo;");
-                }
+                v.invokestatic("jet/typeinfo/TypeInfo", "getTypeInfo", "(Ljava/lang/Class;Z)Ljet/typeinfo/TypeInfo;");
                 v.putstatic(typeMapper.mapType(descriptor.getDefaultType(), kind).getInternalName(), "$staticTypeInfo", "Ljet/typeinfo/TypeInfo;");
             }
         });

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

@@ -18,9 +18,6 @@ import org.jetbrains.jet.lexer.JetTokens;
 import org.objectweb.asm.Opcodes;
 import org.objectweb.asm.Type;
 import org.objectweb.asm.commons.Method;
-import org.objectweb.asm.signature.SignatureVisitor;
-import org.objectweb.asm.signature.SignatureWriter;
-import org.objectweb.asm.util.CheckSignatureAdapter;
 
 import java.util.*;
 
@@ -57,6 +54,9 @@ public class JetTypeMapper {
     public static final Type ARRAY_DOUBLE_TYPE = Type.getType(double[].class);
     public static final Type ARRAY_BOOL_TYPE = Type.getType(boolean[].class);
     public static final Type ARRAY_GENERIC_TYPE = Type.getType(Object[].class);
+    public static final Type JET_PARAMETER_TYPE = Type.getObjectType("jet/typeinfo/JetValueParameter");
+    public static final Type JET_TYPE_PARAMETER_TYPE = Type.getObjectType("jet/typeinfo/JetTypeParameter");
+    public static final Type JET_METHOD_TYPE = Type.getObjectType("jet/typeinfo/JetMethod");
 
     private final JetStandardLibrary standardLibrary;
     private final BindingContext bindingContext;
@@ -86,7 +86,11 @@ public class JetTypeMapper {
     public static final Type TYPE_LONG_ITERATOR = Type.getObjectType("jet/LongIterator");
     public static final Type TYPE_FLOAT_ITERATOR = Type.getObjectType("jet/FloatIterator");
     public static final Type TYPE_DOUBLE_ITERATOR = Type.getObjectType("jet/DoubleIterator");
-    
+
+    public JetStandardLibrary getStandardLibrary() {
+        return standardLibrary;
+    }
+
     public JetTypeMapper(JetStandardLibrary standardLibrary, BindingContext bindingContext) {
         this.standardLibrary = standardLibrary;
         this.bindingContext = bindingContext;
@@ -158,10 +162,10 @@ public class JetTypeMapper {
         return mapReturnType(jetType, null);
     }
 
-    @NotNull private Type mapReturnType(final JetType jetType, @Nullable SignatureVisitor signatureVisitor) {
+    @NotNull private Type mapReturnType(final JetType jetType, @Nullable BothSignatureWriter signatureVisitor) {
         if (jetType.equals(JetStandardClasses.getUnitType()) || jetType.equals(JetStandardClasses.getNothingType())) {
             if (signatureVisitor != null) {
-                signatureVisitor.visitBaseType('V');
+                signatureVisitor.writeAsmType(Type.VOID_TYPE);
             }
             return Type.VOID_TYPE;
         }
@@ -219,10 +223,10 @@ public class JetTypeMapper {
     }
     
     @NotNull public Type mapType(final JetType jetType) {
-        return mapType(jetType, (SignatureVisitor) null);
+        return mapType(jetType, (BothSignatureWriter) null);
     }
 
-    @NotNull private Type mapType(JetType jetType, @Nullable SignatureVisitor signatureVisitor) {
+    @NotNull private Type mapType(JetType jetType, @Nullable BothSignatureWriter signatureVisitor) {
         return mapType(jetType, OwnerKind.IMPLEMENTATION, signatureVisitor);
     }
 
@@ -230,17 +234,22 @@ public class JetTypeMapper {
         return mapType(jetType, kind, null);
     }
 
-    @NotNull private Type mapType(JetType jetType, OwnerKind kind, @Nullable SignatureVisitor signatureVisitor) {
+    @NotNull private Type mapType(JetType jetType, OwnerKind kind, @Nullable BothSignatureWriter signatureVisitor) {
         return mapType(jetType, kind, signatureVisitor, false);
     }
 
-    @NotNull private Type mapType(JetType jetType, OwnerKind kind, @Nullable SignatureVisitor signatureVisitor, boolean boxPrimitive) {
+    @NotNull public Type mapType(JetType jetType, OwnerKind kind, @Nullable BothSignatureWriter signatureVisitor, boolean boxPrimitive) {
         Type known = knowTypes.get(jetType);
         if (known != null) {
             return mapKnownAsmType(jetType, known, signatureVisitor, boxPrimitive);
         }
 
         DeclarationDescriptor descriptor = jetType.getConstructor().getDeclarationDescriptor();
+
+        if (ErrorUtils.isError(descriptor)) {
+            throw new IllegalStateException("should not compile an error type");
+        }
+
         if (standardLibrary.getArray().equals(descriptor)) {
             if (jetType.getArguments().size() != 1) {
                 throw new UnsupportedOperationException("arrays must have one type argument");
@@ -248,8 +257,9 @@ public class JetTypeMapper {
             JetType memberType = jetType.getArguments().get(0).getType();
             
             if (signatureVisitor != null) {
-                SignatureVisitor arraySignatureVisitor = signatureVisitor.visitArrayType();
-                mapType(memberType, kind, arraySignatureVisitor, true);
+                signatureVisitor.writeArrayType();
+                mapType(memberType, kind, signatureVisitor, true);
+                signatureVisitor.writeArrayEnd();
             }
             
             if (!isGenericsArray(jetType)) {
@@ -272,13 +282,14 @@ public class JetTypeMapper {
             Type asmType = Type.getObjectType(name + (kind == OwnerKind.TRAIT_IMPL ? "$$TImpl" : ""));
 
             if (signatureVisitor != null) {
-                signatureVisitor.visitClassType(asmType.getInternalName());
+                signatureVisitor.writeClassBegin(asmType.getInternalName());
                 for (TypeProjection proj : jetType.getArguments()) {
                     // TODO: +-
-                    SignatureVisitor argumentSignatureVisitor = signatureVisitor.visitTypeArgument('=');
-                    mapType(proj.getType(), kind, argumentSignatureVisitor, true);
+                    signatureVisitor.writeTypeArgument('=');
+                    mapType(proj.getType(), kind, signatureVisitor, true);
+                    signatureVisitor.writeTypeArgumentEnd();
                 }
-                signatureVisitor.visitEnd();
+                signatureVisitor.writeClassEnd();
             }
 
             return asmType;
@@ -287,7 +298,7 @@ public class JetTypeMapper {
         if (descriptor instanceof TypeParameterDescriptor) {
             if (signatureVisitor != null) {
                 TypeParameterDescriptor typeParameterDescriptor = (TypeParameterDescriptor) jetType.getConstructor().getDeclarationDescriptor();
-                signatureVisitor.visitTypeVariable(typeParameterDescriptor.getName());
+                signatureVisitor.writeTypeVariable(typeParameterDescriptor.getName());
             }
 
             return mapType(((TypeParameterDescriptor) descriptor).getUpperBoundsAsType(), kind);
@@ -296,7 +307,7 @@ public class JetTypeMapper {
         throw new UnsupportedOperationException("Unknown type " + jetType);
     }
     
-    private Type mapKnownAsmType(JetType jetType, Type asmType, @Nullable SignatureVisitor signatureVisitor, boolean genericTypeParameter) {
+    private Type mapKnownAsmType(JetType jetType, Type asmType, @Nullable BothSignatureWriter signatureVisitor, boolean genericTypeParameter) {
         if (signatureVisitor != null) {
             if (genericTypeParameter) {
                 visitAsmType(signatureVisitor, boxType(asmType));
@@ -307,23 +318,8 @@ public class JetTypeMapper {
         return asmType;
     }
 
-    public static void visitAsmType(SignatureVisitor visitor, Type asmType) {
-        switch (asmType.getSort()) {
-        case Type.OBJECT:
-            visitor.visitClassType(asmType.getInternalName());
-            visitor.visitEnd();
-            return;
-        case Type.ARRAY:
-            SignatureVisitor elementSignatureVisitor = visitor.visitArrayType();
-            visitAsmType(elementSignatureVisitor, asmType.getElementType());
-            return;
-        default:
-            String descriptor = asmType.getDescriptor();
-            if (descriptor.length() != 1) {
-                throw new IllegalStateException();
-            }
-            visitor.visitBaseType(descriptor.charAt(0));
-        }
+    public static void visitAsmType(BothSignatureWriter visitor, Type asmType) {
+        visitor.writeAsmType(asmType);
     }
 
     public static Type unboxType(final Type type) {
@@ -379,8 +375,6 @@ public class JetTypeMapper {
         return asmType;
     }
 
-    public static final boolean DEBUG_SIGNATURE_WRITER = true;
-
     public CallableMethod mapToCallableMethod(FunctionDescriptor functionDescriptor, boolean superCall, OwnerKind kind) {
         if(functionDescriptor == null)
             return null;
@@ -444,22 +438,12 @@ public class JetTypeMapper {
             needGenericSignature = false;
         }
         
-        SignatureWriter signatureWriter = null;
-        SignatureVisitor signatureVisitor = null;
+        BothSignatureWriter signatureVisitor = null;
         if (needGenericSignature) {
-            signatureWriter = new SignatureWriter();
-            signatureVisitor = DEBUG_SIGNATURE_WRITER ? new CheckSignatureAdapter(CheckSignatureAdapter.METHOD_SIGNATURE, signatureWriter) : signatureWriter;
+            signatureVisitor = new BothSignatureWriter(BothSignatureWriter.Mode.METHOD);
         }
 
-        for (TypeParameterDescriptor typeParameterDescriptor : f.getTypeParameters()) {
-            if (signatureVisitor != null) {
-                signatureVisitor.visitFormalTypeParameter(typeParameterDescriptor.getName());
-                SignatureVisitor classBoundVisitor = signatureVisitor.visitClassBound();
-                // TODO: wrong base
-                visitAsmType(classBoundVisitor, TYPE_OBJECT);
-                // TODO: interfaces
-            }
-        }
+        writeFormalTypeParameters(f.getTypeParameters(), signatureVisitor);
 
         final ReceiverDescriptor receiverTypeRef = f.getReceiverParameter();
         final JetType receiverType = !receiverTypeRef.exists() ? null : receiverTypeRef.getType();
@@ -477,24 +461,98 @@ public class JetTypeMapper {
             parameterTypes.add(type);
         }
         if (receiverType != null) {
-            parameterTypes.add(mapType(receiverType, signatureVisitor != null ? signatureVisitor.visitParameterType() : null));
+            if (signatureVisitor != null) {
+                signatureVisitor.writeParameterType();
+            }
+            parameterTypes.add(mapType(receiverType, signatureVisitor));
+            if (signatureVisitor != null) {
+                signatureVisitor.writeParameterTypeEnd();
+            }
         }
         for (TypeParameterDescriptor parameterDescriptor : f.getTypeParameters()) {
             if(parameterDescriptor.isReified()) {
                 parameterTypes.add(TYPE_TYPEINFO);
                 if (signatureVisitor != null) {
-                    visitAsmType(signatureVisitor.visitParameterType(), TYPE_TYPEINFO);
+                    signatureVisitor.writeParameterType();
+                    visitAsmType(signatureVisitor, TYPE_TYPEINFO);
+                    signatureVisitor.writeParameterTypeEnd();
                 }
             }
         }
         for (ValueParameterDescriptor parameter : parameters) {
-            Type type = mapType(parameter.getOutType(), signatureVisitor != null ? signatureVisitor.visitParameterType() : null);
+            if (signatureVisitor != null) {
+                signatureVisitor.writeParameterType();
+            }
+            Type type = mapType(parameter.getOutType(), signatureVisitor);
+            if (signatureVisitor != null) {
+                signatureVisitor.writeParameterTypeEnd();
+            }
             valueParameterTypes.add(type);
             parameterTypes.add(type);
         }
-        Type returnType = f instanceof ConstructorDescriptor ? Type.VOID_TYPE : mapReturnType(f.getReturnType(), signatureVisitor != null ? signatureVisitor.visitReturnType() : null);
+        Type returnType;
+        if (f instanceof ConstructorDescriptor) {
+            returnType = Type.VOID_TYPE;
+            if (signatureVisitor != null) {
+                signatureVisitor.writeReturnType();
+                visitAsmType(signatureVisitor, Type.VOID_TYPE);
+                signatureVisitor.writeReturnTypeEnd();
+            }
+        } else {
+            if (signatureVisitor != null) {
+                signatureVisitor.writeReturnType();
+                returnType = mapReturnType(f.getReturnType(), signatureVisitor);
+                signatureVisitor.writeReturnTypeEnd();
+            }
+            else {
+                returnType = mapReturnType(f.getReturnType(), null);
+            }
+        }
         Method method = new Method(f.getName(), returnType, parameterTypes.toArray(new Type[parameterTypes.size()]));
-        return new JvmMethodSignature(method, signatureWriter != null ? signatureWriter.toString() : null);
+        return new JvmMethodSignature(method, signatureVisitor != null ? signatureVisitor.makeJavaString() : null);
+    }
+
+
+    public void writeFormalTypeParameters(List<TypeParameterDescriptor> typeParameters, BothSignatureWriter signatureVisitor) {
+        if (signatureVisitor == null) {
+            return;
+        }
+
+        for (TypeParameterDescriptor typeParameterDescriptor : typeParameters) {
+            writeFormalTypeParameter(typeParameterDescriptor, signatureVisitor);
+        }
+    }
+
+    private void writeFormalTypeParameter(TypeParameterDescriptor typeParameterDescriptor, BothSignatureWriter signatureVisitor) {
+        signatureVisitor.writeFormalTypeParameter(typeParameterDescriptor.getName());
+
+        classBound:
+        {
+            signatureVisitor.writeClassBound();
+
+            for (JetType jetType : typeParameterDescriptor.getUpperBounds()) {
+                if (jetType.getConstructor().getDeclarationDescriptor() instanceof ClassDescriptor) {
+                    if (!CodegenUtil.isInterface(jetType)) {
+                        mapType(jetType, signatureVisitor);
+                        break classBound;
+                    }
+                }
+            }
+
+            // "extends Object" seems to be not optional according to ClassFileFormat-Java5.pdf
+        }
+        signatureVisitor.writeClassBoundEnd();
+
+        for (JetType jetType : typeParameterDescriptor.getUpperBounds()) {
+            if (jetType.getConstructor().getDeclarationDescriptor() instanceof ClassDescriptor) {
+                if (CodegenUtil.isInterface(jetType)) {
+                    signatureVisitor.writeInterfaceBound();
+                    mapType(jetType, signatureVisitor);
+                    signatureVisitor.writeInterfaceBoundEnd();
+                }
+            }
+        }
+
     }
 
     public JvmMethodSignature mapSignature(String name, FunctionDescriptor f) {
@@ -575,10 +633,8 @@ public class JetTypeMapper {
             parameterTypes.add(mapType(CodegenUtil.getOuterClassDescriptor(classDescriptor).getDefaultType(), OwnerKind.IMPLEMENTATION));
         }
 
-        List<TypeParameterDescriptor> typeParameters = classDescriptor.getTypeConstructor().getParameters();
-        for (TypeParameterDescriptor typeParameter : typeParameters) {
-            if(typeParameter.isReified())
-                parameterTypes.add(TYPE_TYPEINFO);
+        if (CodegenUtil.requireTypeInfoConstructorArg(classDescriptor.getDefaultType())) {
+            parameterTypes.add(TYPE_TYPEINFO);
         }
 
         for (ValueParameterDescriptor parameter : parameters) {

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

@@ -0,0 +1,36 @@
+package org.jetbrains.jet.codegen;
+
+import java.util.List;
+
+/**
+ * @author Stepan Koltsov
+ */
+public class JvmClassSignature {
+    private final String name;
+    private final String superclassName;
+    private final List<String> interfaces;
+    private final String genericSignature;
+
+    public JvmClassSignature(String name, String superclassName, List<String> interfaces, String genericSignature) {
+        this.name = name;
+        this.superclassName = superclassName;
+        this.interfaces = interfaces;
+        this.genericSignature = genericSignature;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public String getSuperclassName() {
+        return superclassName;
+    }
+
+    public List<String> getInterfaces() {
+        return interfaces;
+    }
+
+    public String getGenericSignature() {
+        return genericSignature;
+    }
+}

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

@@ -2,10 +2,12 @@ package org.jetbrains.jet.codegen;
 
 import com.intellij.psi.PsiFile;
 import org.jetbrains.jet.lang.descriptors.DeclarationDescriptor;
+import org.jetbrains.jet.lang.descriptors.NamespaceDescriptor;
 import org.jetbrains.jet.lang.descriptors.PropertyDescriptor;
 import org.jetbrains.jet.lang.psi.*;
 import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.lang.resolve.java.JavaClassDescriptor;
+import org.jetbrains.jet.lang.types.JetStandardClasses;
 import org.jetbrains.jet.lang.types.JetType;
 import org.jetbrains.jet.lang.types.TypeProjection;
 import org.jetbrains.jet.lang.types.TypeUtils;
@@ -42,7 +44,8 @@ public class NamespaceCodegen {
     }
 
     public void generate(JetNamespace namespace) {
-        final CodegenContext context = CodegenContext.STATIC.intoNamespace(state.getBindingContext().get(BindingContext.NAMESPACE, namespace));
+        NamespaceDescriptor descriptor = state.getBindingContext().get(BindingContext.NAMESPACE, namespace);
+        final CodegenContext context = CodegenContext.STATIC.intoNamespace(descriptor);
 
         final FunctionCodegen functionCodegen = new FunctionCodegen(context, v, state);
         final PropertyCodegen propertyCodegen = new PropertyCodegen(context, v, functionCodegen, state);
@@ -145,7 +148,7 @@ public class NamespaceCodegen {
         }
 
         DeclarationDescriptor declarationDescriptor = jetType.getConstructor().getDeclarationDescriptor();
-        if(!jetType.equals(root) && jetType.getArguments().size() == 0 && !(declarationDescriptor instanceof JavaClassDescriptor)) {
+        if(!jetType.equals(root) && jetType.getArguments().size() == 0 && !(declarationDescriptor instanceof JavaClassDescriptor) && !JetStandardClasses.getAny().equals(declarationDescriptor)) {
             // TODO: we need some better checks here
             v.getstatic(typeMapper.mapType(jetType, OwnerKind.IMPLEMENTATION).getInternalName(), "$typeInfo", "Ljet/typeinfo/TypeInfo;");
             return;

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

@@ -7,6 +7,7 @@ import org.jetbrains.jet.lang.descriptors.*;
 import org.jetbrains.jet.lang.psi.JetExpression;
 import org.jetbrains.jet.lang.resolve.calls.ResolvedCall;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverDescriptor;
+import org.jetbrains.jet.lang.types.JetType;
 import org.jetbrains.jet.lexer.JetTokens;
 import org.objectweb.asm.Label;
 import org.objectweb.asm.Opcodes;
@@ -629,7 +630,7 @@ public abstract class StackValue {
 
                 for (TypeParameterDescriptor typeParameterDescriptor : setterDescriptor.getOriginal().getTypeParameters()) {
                     if(typeParameterDescriptor.isReified()) {
-                        codegen.generateTypeInfo(resolvedSetCall.getTypeArguments().get(typeParameterDescriptor));
+                        codegen.generateTypeInfo(resolvedSetCall.getTypeArguments().get(typeParameterDescriptor), null);
                     }
                 }
 
@@ -1010,7 +1011,8 @@ public abstract class StackValue {
                         return codegen.typeMapper.mapType(callableMethod.getReceiverClass());
                     }
                     else {
-                        return codegen.typeMapper.mapType(callableMethod.getThisType());
+                        JetType thisType = callableMethod.getThisType();
+                        return codegen.typeMapper.mapType(thisType);
                     }
                 }
                 else {

compiler/backend/src/org/jetbrains/jet/codegen/intrinsics/ArrayIterator.java

@@ -5,14 +5,12 @@ import org.jetbrains.jet.codegen.ExpressionCodegen;
 import org.jetbrains.jet.codegen.JetTypeMapper;
 import org.jetbrains.jet.codegen.StackValue;
 import org.jetbrains.jet.lang.descriptors.ClassDescriptor;
-import org.jetbrains.jet.lang.descriptors.DeclarationDescriptor;
 import org.jetbrains.jet.lang.descriptors.FunctionDescriptor;
 import org.jetbrains.jet.lang.psi.JetCallExpression;
 import org.jetbrains.jet.lang.psi.JetExpression;
 import org.jetbrains.jet.lang.psi.JetSimpleNameExpression;
 import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.lang.types.JetStandardLibrary;
-import org.jetbrains.jet.lang.types.JetType;
 import org.objectweb.asm.Type;
 import org.objectweb.asm.commons.InstructionAdapter;
 
@@ -30,7 +28,7 @@ public class ArrayIterator implements IntrinsicMethod {
         ClassDescriptor containingDeclaration = (ClassDescriptor) funDescriptor.getContainingDeclaration().getOriginal();
         JetStandardLibrary standardLibrary = codegen.getState().getStandardLibrary();
         if(containingDeclaration.equals(standardLibrary.getArray())) {
-            codegen.generateTypeInfo(funDescriptor.getReturnType().getArguments().get(0).getType());
+            codegen.generateTypeInfo(funDescriptor.getReturnType().getArguments().get(0).getType(), null);
             v.invokestatic("jet/runtime/ArrayIterator", "iterator", "([Ljava/lang/Object;Ljet/typeinfo/TypeInfo;)Ljet/Iterator;");
             return StackValue.onStack(JetTypeMapper.TYPE_ITERATOR);
         }

compiler/backend/src/org/jetbrains/jet/codegen/intrinsics/ValueTypeInfo.java

@@ -17,7 +17,7 @@ public class ValueTypeInfo implements IntrinsicMethod {
     @Override
     public StackValue generate(ExpressionCodegen codegen, InstructionAdapter v, Type expectedType, PsiElement element, List<JetExpression> arguments, StackValue receiver) {
         codegen.gen(arguments.get(0), JetTypeMapper.TYPE_JET_OBJECT);
-        v.invokeinterface("jet/JetObject", "getTypeInfo", "()Ljet/typeinfo/TypeInfo;");
+        v.invokeinterface(JetTypeMapper.TYPE_JET_OBJECT.getInternalName(), "getTypeInfo", "()Ljet/typeinfo/TypeInfo;");
         return StackValue.onStack(JetTypeMapper.TYPE_TYPEINFO);
     }
 }

compiler/backend/src/org/jetbrains/jet/codegen/signature/JetSignatureReader.java

@@ -0,0 +1,161 @@
+package org.jetbrains.jet.codegen.signature;
+
+import org.objectweb.asm.signature.SignatureReader;
+import org.objectweb.asm.signature.SignatureVisitor;
+
+/**
+ * @author Stepan Koltsov
+ * 
+ * @see SignatureReader
+ */
+public class JetSignatureReader {
+    
+    private final String signature;
+
+    public JetSignatureReader(String signature) {
+        this.signature = signature;
+    }
+
+
+    public void accept(final JetSignatureVisitor v) {
+        String signature = this.signature;
+        int len = signature.length();
+        int pos;
+        char c;
+
+        if (signature.charAt(0) == '<') {
+            pos = 2;
+            do {
+                int end = signature.indexOf(':', pos);
+                v.visitFormalTypeParameter(signature.substring(pos - 1, end));
+                pos = end + 1;
+
+                c = signature.charAt(pos);
+                if (c == 'L' || c == '[' || c == 'T') {
+                    pos = parseType(signature, pos, v.visitClassBound());
+                }
+
+                while ((c = signature.charAt(pos++)) == ':') {
+                    pos = parseType(signature, pos, v.visitInterfaceBound());
+                }
+            } while (c != '>');
+        } else {
+            pos = 0;
+        }
+
+        if (signature.charAt(pos) == '(') {
+            pos++;
+            while (signature.charAt(pos) != ')') {
+                pos = parseType(signature, pos, v.visitParameterType());
+            }
+            pos = parseType(signature, pos + 1, v.visitReturnType());
+            while (pos < len) {
+                pos = parseType(signature, pos + 1, v.visitExceptionType());
+            }
+        } else {
+            pos = parseType(signature, pos, v.visitSuperclass());
+            while (pos < len) {
+                pos = parseType(signature, pos, v.visitInterface());
+            }
+        }
+    }
+
+
+    private static int parseType(
+            final String signature,
+            int pos,
+            final JetSignatureVisitor v)
+    {
+        char c;
+        int start, end;
+        boolean visited, inner;
+        String name;
+
+        boolean nullable = false;
+        if (signature.charAt(pos) == '?') {
+            nullable = true;
+            pos++;
+        }
+
+        switch (c = signature.charAt(pos++)) {
+            case 'Z':
+            case 'C':
+            case 'B':
+            case 'S':
+            case 'I':
+            case 'F':
+            case 'J':
+            case 'D':
+            case 'V':
+                v.visitBaseType(c, nullable);
+                return pos;
+
+            case '[':
+                return parseType(signature, pos, v.visitArrayType(nullable));
+
+            case 'T':
+                end = signature.indexOf(';', pos);
+                v.visitTypeVariable(signature.substring(pos, end), nullable);
+                return end + 1;
+
+            default: // case 'L':
+                start = pos;
+                visited = false;
+                inner = false;
+                for (;;) {
+                    switch (c = signature.charAt(pos++)) {
+                        case '.':
+                        case ';':
+                            if (!visited) {
+                                name = signature.substring(start, pos - 1);
+                                if (inner) {
+                                    v.visitInnerClassType(name, nullable);
+                                } else {
+                                    v.visitClassType(name, nullable);
+                                }
+                            }
+                            if (c == ';') {
+                                v.visitEnd();
+                                return pos;
+                            }
+                            start = pos;
+                            visited = false;
+                            inner = true;
+                            break;
+
+                        case '<':
+                            name = signature.substring(start, pos - 1);
+                            if (inner) {
+                                v.visitInnerClassType(name, nullable);
+                            } else {
+                                v.visitClassType(name, nullable);
+                            }
+                            visited = true;
+                            top: for (;;) {
+                                switch (c = signature.charAt(pos)) {
+                                    case '>':
+                                        break top;
+                                    case '*':
+                                        ++pos;
+                                        v.visitTypeArgument();
+                                        break;
+                                    case '+':
+                                    case '-':
+                                        pos = parseType(signature,
+                                                        pos + 1,
+                                                        v.visitTypeArgument(c));
+                                        break;
+                                    default:
+                                        pos = parseType(signature,
+                                                        pos,
+                                                        v.visitTypeArgument('='));
+                                        break;
+                                }
+                            }
+                    }
+                }
+        }
+    }
+
+
+}

compiler/backend/src/org/jetbrains/jet/codegen/signature/JetSignatureVisitor.java

@@ -0,0 +1,141 @@
+package org.jetbrains.jet.codegen.signature;
+
+import org.objectweb.asm.signature.SignatureVisitor;
+
+/**
+ * @author Stepan Koltsov
+ *
+ * @see SignatureVisitor
+ * @url http://confluence.jetbrains.net/display/JET/Jet+Signatures
+ */
+public interface JetSignatureVisitor {
+
+    /**
+     * Wildcard for an "extends" type argument.
+     */
+    char EXTENDS = '+';
+
+    /**
+     * Wildcard for a "super" type argument.
+     */
+    char SUPER = '-';
+
+    /**
+     * Wildcard for a normal type argument.
+     */
+    char INSTANCEOF = '=';
+
+    /**
+     * Visits a formal type parameter.
+     *
+     * @param name the name of the formal parameter.
+     */
+    void visitFormalTypeParameter(String name);
+
+    /**
+     * Visits the class bound of the last visited formal type parameter.
+     *
+     * @return a non null visitor to visit the signature of the class bound.
+     */
+    JetSignatureVisitor visitClassBound();
+
+    /**
+     * Visits an interface bound of the last visited formal type parameter.
+     *
+     * @return a non null visitor to visit the signature of the interface bound.
+     */
+    JetSignatureVisitor visitInterfaceBound();
+
+    /**
+     * Visits the type of the super class.
+     *
+     * @return a non null visitor to visit the signature of the super class
+     *         type.
+     */
+    JetSignatureVisitor visitSuperclass();
+
+    /**
+     * Visits the type of an interface implemented by the class.
+     *
+     * @return a non null visitor to visit the signature of the interface type.
+     */
+    JetSignatureVisitor visitInterface();
+
+    /**
+     * Visits the type of a method parameter.
+     *
+     * @return a non null visitor to visit the signature of the parameter type.
+     */
+    JetSignatureVisitor visitParameterType();
+
+    /**
+     * Visits the return type of the method.
+     *
+     * @return a non null visitor to visit the signature of the return type.
+     */
+    JetSignatureVisitor visitReturnType();
+
+    /**
+     * Visits the type of a method exception.
+     *
+     * @return a non null visitor to visit the signature of the exception type.
+     */
+    JetSignatureVisitor visitExceptionType();
+
+    /**
+     * Visits a signature corresponding to a primitive type.
+     *
+     * @param descriptor the descriptor of the primitive type, or 'V' for
+     *        <tt>void</tt>.
+     */
+    void visitBaseType(char descriptor, boolean nullable);
+
+    /**
+     * Visits a signature corresponding to a type variable.
+     *
+     * @param name the name of the type variable.
+     */
+    void visitTypeVariable(String name, boolean nullable);
+
+    /**
+     * Visits a signature corresponding to an array type.
+     *
+     * @return a non null visitor to visit the signature of the array element
+     *         type.
+     */
+    JetSignatureVisitor visitArrayType(boolean nullable);
+
+    /**
+     * Starts the visit of a signature corresponding to a class or interface
+     * type.
+     *
+     * @param name the internal name of the class or interface.
+     */
+    void visitClassType(String name, boolean nullable);
+
+    /**
+     * Visits an inner class.
+     *
+     * @param name the local name of the inner class in its enclosing class.
+     */
+    void visitInnerClassType(String name, boolean nullable);
+
+    /**
+     * Visits an unbounded type argument of the last visited class or inner
+     * class type.
+     */
+    void visitTypeArgument();
+
+    /**
+     * Visits a type argument of the last visited class or inner class type.
+     *
+     * @param wildcard '+', '-' or '='.
+     * @return a non null visitor to visit the signature of the type argument.
+     */
+    JetSignatureVisitor visitTypeArgument(char wildcard);
+
+    /**
+     * Ends the visit of a signature corresponding to a class or interface type.
+     */
+    void visitEnd();
+}

compiler/backend/src/org/jetbrains/jet/codegen/signature/JetSignatureWriter.java

@@ -0,0 +1,201 @@
+package org.jetbrains.jet.codegen.signature;
+
+import org.objectweb.asm.signature.SignatureWriter;
+
+/**
+ * @author Stepan Koltsov
+ *
+ * @see SignatureWriter
+ */
+public class JetSignatureWriter implements JetSignatureVisitor {
+
+    /**
+     * Buffer used to construct the signature.
+     */
+    private final StringBuffer buf = new StringBuffer();
+
+    /**
+     * Indicates if the signature contains formal type parameters.
+     */
+    private boolean hasFormals;
+
+    /**
+     * Indicates if the signature contains method parameter types.
+     */
+    private boolean hasParameters;
+
+    /**
+     * Stack used to keep track of class types that have arguments. Each element
+     * of this stack is a boolean encoded in one bit. The top of the stack is
+     * the lowest order bit. Pushing false = *2, pushing true = *2+1, popping =
+     * /2.
+     */
+    private int argumentStack;
+
+    /**
+     * Constructs a new {@link SignatureWriter} object.
+     */
+    public JetSignatureWriter() {
+    }
+
+    // ------------------------------------------------------------------------
+    // Implementation of the SignatureVisitor interface
+    // ------------------------------------------------------------------------
+
+    @Override
+    public void visitFormalTypeParameter(final String name) {
+        if (!hasFormals) {
+            hasFormals = true;
+            buf.append('<');
+        }
+        buf.append(name);
+        buf.append(':');
+    }
+
+    @Override
+    public JetSignatureWriter visitClassBound() {
+        return this;
+    }
+
+    @Override
+    public JetSignatureWriter visitInterfaceBound() {
+        buf.append(':');
+        return this;
+    }
+
+    @Override
+    public JetSignatureWriter visitSuperclass() {
+        endFormals();
+        return this;
+    }
+
+    @Override
+    public JetSignatureWriter visitInterface() {
+        return this;
+    }
+
+    @Override
+    public JetSignatureWriter visitParameterType() {
+        endFormals();
+        if (!hasParameters) {
+            hasParameters = true;
+            buf.append('(');
+        }
+        return this;
+    }
+
+    @Override
+    public JetSignatureWriter visitReturnType() {
+        endFormals();
+        if (!hasParameters) {
+            buf.append('(');
+        }
+        buf.append(')');
+        return this;
+    }
+
+    @Override
+    public JetSignatureWriter visitExceptionType() {
+        buf.append('^');
+        return this;
+    }
+
+    private void visitNullabe(boolean nullable) {
+        if (nullable) {
+            buf.append('?');
+        }
+    }
+
+    @Override
+    public void visitBaseType(final char descriptor, boolean nullable) {
+        visitNullabe(nullable);
+        buf.append(descriptor);
+    }
+
+    @Override
+    public void visitTypeVariable(final String name, boolean nullable) {
+        visitNullabe(nullable);
+        buf.append('T');
+        buf.append(name);
+        buf.append(';');
+    }
+
+    @Override
+    public JetSignatureWriter visitArrayType(boolean nullable) {
+        visitNullabe(nullable);
+        buf.append('[');
+        return this;
+    }
+
+    @Override
+    public void visitClassType(final String name, boolean nullable) {
+        visitNullabe(nullable);
+        buf.append('L');
+        buf.append(name);
+        argumentStack *= 2;
+    }
+
+    @Override
+    public void visitInnerClassType(final String name, boolean nullable) {
+        endArguments();
+        visitNullabe(nullable);
+        buf.append('.');
+        buf.append(name);
+        argumentStack *= 2;
+    }
+
+    @Override
+    public void visitTypeArgument() {
+        if (argumentStack % 2 == 0) {
+            ++argumentStack;
+            buf.append('<');
+        }
+        buf.append('*');
+    }
+
+    @Override
+    public JetSignatureWriter visitTypeArgument(final char wildcard) {
+        if (argumentStack % 2 == 0) {
+            ++argumentStack;
+            buf.append('<');
+        }
+        if (wildcard != '=') {
+            buf.append(wildcard);
+        }
+        return this;
+    }
+
+    @Override
+    public void visitEnd() {
+        endArguments();
+        buf.append(';');
+    }
+
+    public String toString() {
+        return buf.toString();
+    }
+
+    // ------------------------------------------------------------------------
+    // Utility methods
+    // ------------------------------------------------------------------------
+
+    /**
+     * Ends the formal type parameters section of the signature.
+     */
+    private void endFormals() {
+        if (hasFormals) {
+            hasFormals = false;
+            buf.append('>');
+        }
+    }
+
+    /**
+     * Ends the type arguments of a class or inner class type.
+     */
+    private void endArguments() {
+        if (argumentStack % 2 != 0) {
+            buf.append('>');
+        }
+        argumentStack /= 2;
+    }
+}

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaDescriptorResolver.java

@@ -14,7 +14,6 @@ import org.jetbrains.jet.lang.descriptors.*;
 import org.jetbrains.jet.lang.descriptors.annotations.AnnotationDescriptor;
 import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.lang.resolve.DescriptorUtils;
-import org.jetbrains.jet.lang.resolve.StdlibNames;
 import org.jetbrains.jet.lang.types.*;
 import org.jetbrains.jet.plugin.JetFileType;
 
@@ -370,13 +369,13 @@ public class JavaDescriptorResolver {
             PsiNameValuePair[] attributes = annotation.getParameterList().getAttributes();
             attributes.toString();
 
-            if (annotation.getQualifiedName().equals(StdlibNames.JET_PARAMETER_CLASS)) {
-                PsiLiteralExpression nameExpression = (PsiLiteralExpression) annotation.findAttributeValue(StdlibNames.JET_PARAMETER_NAME_FIELD);
+            if (annotation.getQualifiedName().equals(StdlibNames.JET_VALUE_PARAMETER_CLASS)) {
+                PsiLiteralExpression nameExpression = (PsiLiteralExpression) annotation.findAttributeValue(StdlibNames.JET_VALUE_PARAMETER_NAME_FIELD);
                 if (nameExpression != null) {
                     name = (String) nameExpression.getValue();
                 }
                 
-                PsiLiteralExpression nullableExpression = (PsiLiteralExpression) annotation.findAttributeValue(StdlibNames.JET_PARAMETER_NULLABLE_FIELD);
+                PsiLiteralExpression nullableExpression = (PsiLiteralExpression) annotation.findAttributeValue(StdlibNames.JET_VALUE_PARAMETER_NULLABLE_FIELD);
                 if (nullableExpression != null) {
                     nullable = (Boolean) nullableExpression.getValue();
                 } else {

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaPackageScope.java

@@ -58,7 +58,6 @@ public class JavaPackageScope extends JetScopeImpl {
             return Collections.emptySet();
         }
 
-        System.out.println(psiClass.getQualifiedName());
         return semanticServices.getDescriptorResolver().resolveFunctionGroup(containingDescriptor, psiClass, null, name, true);
 //            return Collections.emptySet();
     }
@@ -78,6 +77,7 @@ public class JavaPackageScope extends JetScopeImpl {
             final PsiPackage javaPackage = semanticServices.getDescriptorResolver().findPackage(packageFQN);
 
             if (javaPackage != null) {
+                boolean isKotlinNamespace = semanticServices.getKotlinNamespaceDescriptor(javaPackage.getQualifiedName()) != null;
                 final JavaDescriptorResolver descriptorResolver = semanticServices.getDescriptorResolver();
 
                 for (PsiPackage psiSubPackage : javaPackage.getSubPackages()) {
@@ -85,6 +85,8 @@ public class JavaPackageScope extends JetScopeImpl {
                 }
 
                 for (PsiClass psiClass : javaPackage.getClasses()) {
+                    if (isKotlinNamespace && "namespace".equals(psiClass.getName())) continue;
+
                     // If this is a Kotlin class, we have already taken it through a containing namespace descriptor
                     ClassDescriptor kotlinClassDescriptor = semanticServices.getKotlinClassDescriptor(psiClass.getQualifiedName());
                     if (kotlinClassDescriptor != null) {

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/StdlibNames.java

@@ -0,0 +1,36 @@
+package org.jetbrains.jet.lang.resolve.java;
+
+import org.objectweb.asm.Type;
+
+/**
+ * @author Stepan Koltsov
+ */
+public class StdlibNames {
+
+    public static final String JET_VALUE_PARAMETER_CLASS = "jet.typeinfo.JetValueParameter";
+    public static final String JET_VALUE_PARAMETER_DESCRIPTOR = "Ljet/typeinfo/JetValueParameter;";
+    
+    public static final String JET_VALUE_PARAMETER_NAME_FIELD = "name";
+    public static final String JET_VALUE_PARAMETER_HAS_DEFAULT_VALUE_FIELD = "hasDefaultValue";
+    public static final String JET_VALUE_PARAMETER_NULLABLE_FIELD = "nullable";
+
+
+    public static final String JET_TYPE_PARAMETER_CLASS = "jet.typeinfo.JetTypeParameter";
+    public static final String JET_TYPE_PARAMETER_DESCRIPTOR = "Ljet/typeinfo/JetTypeParameter;";
+    
+    public static final String JET_TYPE_PARAMETER_NAME_FIELD = "name";
+
+
+    public static final String JET_METHOD_CLASS = "jet.typeinfo.JetMethod";
+    public static final String JET_METHOD_DESCRIPTOR = "Ljet/typeinfo/JetMethod;";
+    
+    public static final String JET_METHOD_NULLABLE_RETURN_TYPE_FIELD = "nullableReturnType";
+
+
+    public static final String JET_OBJECT_INTERNAL = "jet/JetObject";
+    public static final String JET_OBJECT_CLASS = "jet.JetObject";
+    public static final String JET_OBJECT_DESCRIPTOR = "Ljet/JetObject;";
+
+    private StdlibNames() {
+    }
+}

compiler/frontend/src/org/jetbrains/jet/lang/psi/JetPsiUtil.java

@@ -131,11 +131,15 @@ public class JetPsiUtil {
     public static String getFQName(JetClass jetClass) {
         JetNamedDeclaration parent = PsiTreeUtil.getParentOfType(jetClass, JetNamespace.class, JetClass.class);
         if (parent instanceof JetNamespace) {
-            return getFQName(((JetNamespace) parent)) + "." + jetClass.getName();
+            return makeFQName(getFQName(((JetNamespace) parent)), jetClass);
         }
         if (parent instanceof JetClass) {
-            return getFQName(((JetClass) parent)) + "." + jetClass.getName();
+            return makeFQName(getFQName(((JetClass) parent)), jetClass);
         }
         return jetClass.getName();
     }
+
+    private static String makeFQName(String prefix, JetClass jetClass) {
+        return (prefix.length() == 0 ? "" : prefix + ".") + jetClass.getName();
+    }
 }

compiler/frontend/src/org/jetbrains/jet/lang/resolve/StdlibNames.java

@@ -1,32 +0,0 @@
-package org.jetbrains.jet.lang.resolve;
-
-import org.objectweb.asm.Type;
-
-/**
- * @author Stepan Koltsov
- */
-public class StdlibNames {
-    
-    public static final Type JET_PARAMETER_TYPE = Type.getObjectType("jet/typeinfo/JetParameter");
-    public static final String JET_PARAMETER_CLASS = "jet.typeinfo.JetParameter";
-    public static final String JET_PARAMETER_DESCRIPTOR = "Ljet/typeinfo/JetParameter;";
-    
-    public static final String JET_PARAMETER_NAME_FIELD = "name";
-    public static final String JET_PARAMETER_HAS_DEFAULT_VALUE_FIELD = "hasDefaultValue";
-    public static final String JET_PARAMETER_NULLABLE_FIELD = "nullable";
-    
-    
-    public static final Type JET_TYPE_PARAMETER_TYPE = Type.getObjectType("jet/typeinfo/JetTypeParameter");
-    public static final String JET_TYPE_PARAMETER_CLASS = "jet.typeinfo.JetTypeParameter";
-    public static final String JET_TYPE_PARAMETER_DESCRIPTOR = "Ljet/typeinfo/JetTypeParameter;";
-    
-    public static final String JET_TYPE_PARAMETER_NAME_FIELD = "name";
-    
-    
-    public static final Type JET_METHOD_TYPE = Type.getObjectType("jet/typeinfo/JetMethod");
-    public static final String JET_METHOD_CLASS = "jet.typeinfo.JetMethod";
-    public static final String JET_METHOD_DESCRIPTOR = "Ljet/typeinfo/JetMethod;";
-    
-    public static final String JET_METHOD_NULLABLE_RETURN_TYPE_FIELD = "nullableReturnType";
-    
-}

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/CallResolver.java

@@ -29,6 +29,9 @@ import static org.jetbrains.jet.lang.resolve.BindingContext.*;
 import static org.jetbrains.jet.lang.resolve.calls.ResolutionStatus.*;
 import static org.jetbrains.jet.lang.resolve.calls.ResolvedCallImpl.MAP_TO_CANDIDATE;
 import static org.jetbrains.jet.lang.resolve.calls.ResolvedCallImpl.MAP_TO_RESULT;
+import static org.jetbrains.jet.lang.resolve.calls.inference.ConstraintType.EXPECTED_TYPE;
+import static org.jetbrains.jet.lang.resolve.calls.inference.ConstraintType.RECEIVER;
+import static org.jetbrains.jet.lang.resolve.calls.inference.ConstraintType.VALUE_ARGUMENT;
 import static org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverDescriptor.NO_RECEIVER;
 import static org.jetbrains.jet.lang.types.TypeUtils.NO_EXPECTED_TYPE;
 
@@ -470,7 +473,7 @@ public class CallResolver {
                             ExpressionTypingServices temporaryServices = new ExpressionTypingServices(semanticServices, traceForUnknown);
                             JetType type = temporaryServices.getType(scope, expression, substituteDontCare.substitute(valueParameterDescriptor.getOutType(), Variance.INVARIANT));
                             if (type != null) {
-                                constraintSystem.addSubtypingConstraint(type, effectiveExpectedType);
+                                constraintSystem.addSubtypingConstraint(VALUE_ARGUMENT.assertSubtyping(type, effectiveExpectedType));
                             }
                             else {
                                 candidateCall.argumentHasNoType();
@@ -483,12 +486,12 @@ public class CallResolver {
                     ReceiverDescriptor receiverArgument = candidateCall.getReceiverArgument();
                     ReceiverDescriptor receiverParameter = candidateWithFreshVariables.getReceiverParameter();
                     if (receiverArgument.exists() && receiverParameter.exists()) {
-                        constraintSystem.addSubtypingConstraint(receiverArgument.getType(), receiverParameter.getType());
+                        constraintSystem.addSubtypingConstraint(RECEIVER.assertSubtyping(receiverArgument.getType(), receiverParameter.getType()));
                     }
 
                     // Return type
                     if (expectedType != NO_EXPECTED_TYPE) {
-                        constraintSystem.addSubtypingConstraint(candidateWithFreshVariables.getReturnType(), expectedType);
+                        constraintSystem.addSubtypingConstraint(EXPECTED_TYPE.assertSubtyping(candidateWithFreshVariables.getReturnType(), expectedType));
                     }
 
                     // Solution

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/ResolutionDebugInfo.java

@@ -5,7 +5,7 @@ import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.psi.PsiElement;
 import org.jetbrains.jet.lang.descriptors.CallableDescriptor;
 import org.jetbrains.jet.lang.descriptors.TypeParameterDescriptor;
-import org.jetbrains.jet.lang.resolve.calls.inference.ConstraintSystemImpl;
+import org.jetbrains.jet.lang.resolve.calls.inference.BoundsOwner;
 import org.jetbrains.jet.lang.resolve.calls.inference.ConstraintSystemSolution;
 import org.jetbrains.jet.lang.types.JetType;
 import org.jetbrains.jet.util.slicedmap.*;
@@ -22,8 +22,8 @@ public class ResolutionDebugInfo {
     public static final WritableSlice<One, ResolvedCall<? extends CallableDescriptor>> RESULT = Slices.createSimpleSlice();
     public static final WritableSlice<One, StringBuilder> ERRORS = Slices.createSimpleSlice();
     public static final WritableSlice<One, StringBuilder> LOG = Slices.createSimpleSlice();
-    public static final WritableSlice<One, Map<TypeParameterDescriptor, ConstraintSystemImpl.TypeValue>> BOUNDS_FOR_UNKNOWNS = Slices.createSimpleSlice();
-    public static final WritableSlice<One, Map<JetType, ConstraintSystemImpl.TypeValue>> BOUNDS_FOR_KNOWNS = Slices.createSimpleSlice();
+    public static final WritableSlice<One, Map<TypeParameterDescriptor, BoundsOwner>> BOUNDS_FOR_UNKNOWNS = Slices.createSimpleSlice();
+    public static final WritableSlice<One, Map<JetType, BoundsOwner>> BOUNDS_FOR_KNOWNS = Slices.createSimpleSlice();
     public static final WritableSlice<One, ConstraintSystemSolution> SOLUTION = Slices.createSimpleSlice();
     public static final WritableSlice<One, Collection<TypeParameterDescriptor>> UNKNOWNS = Slices.createSimpleSlice();
 

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/ResolvedCall.java

@@ -13,11 +13,11 @@ import java.util.Map;
  * @author abreslav
  */
 public interface ResolvedCall<D extends CallableDescriptor> {
-    /** A target callable descriptor as it was accessible in the corresponding scope, i.e. with type parameters not substituted */
+    /** A target callable descriptor as it was accessible in the corresponding scope, i.e. with type arguments not substituted */
     @NotNull
     D getCandidateDescriptor();
 
-    /** Type parameters are substituted */
+    /** Type arguments are substituted. This descriptor is guaranteed to have NO declared type parameters */
     @NotNull
     D getResultingDescriptor();
 

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/BoundsOwner.java

@@ -0,0 +1,16 @@
+package org.jetbrains.jet.lang.resolve.calls.inference;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Set;
+
+/**
+ * @author abreslav
+ */
+public interface BoundsOwner {
+    @NotNull
+    Set<TypeValue> getUpperBounds();
+
+    @NotNull
+    Set<TypeValue> getLowerBounds();
+}

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintResolutionListener.java

@@ -12,11 +12,11 @@ public interface ConstraintResolutionListener {
 
     public static final ConstraintResolutionListener DO_NOTHING = new ConstraintResolutionListener() {
         @Override
-        public void constraintsForUnknown(TypeParameterDescriptor typeParameterDescriptor, ConstraintSystemImpl.TypeValue typeValue) {
+        public void constraintsForUnknown(TypeParameterDescriptor typeParameterDescriptor, BoundsOwner typeValue) {
         }
 
         @Override
-        public void constraintsForKnownType(JetType type, ConstraintSystemImpl.TypeValue typeValue) {
+        public void constraintsForKnownType(JetType type, BoundsOwner typeValue) {
         }
 
         @Override
@@ -24,18 +24,18 @@ public interface ConstraintResolutionListener {
         }
 
         @Override
-        public void log(Object message) {
+        public void log(Object... messageFragments) {
         }
 
         @Override
-        public void error(Object message) {
+        public void error(Object... messageFragments) {
         }
     };
 
-    void constraintsForUnknown(TypeParameterDescriptor typeParameterDescriptor, ConstraintSystemImpl.TypeValue typeValue);
-    void constraintsForKnownType(JetType type, ConstraintSystemImpl.TypeValue typeValue);
+    void constraintsForUnknown(TypeParameterDescriptor typeParameterDescriptor, BoundsOwner typeValue);
+    void constraintsForKnownType(JetType type, BoundsOwner typeValue);
     void done(ConstraintSystemSolution solution, Set<TypeParameterDescriptor> typeParameterDescriptors);
 
-    void log(Object message);
-    void error(Object message);
+    void log(Object... messageFragments);
+    void error(Object... messageFragments);
 }

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintSystem.java

@@ -2,7 +2,6 @@ package org.jetbrains.jet.lang.resolve.calls.inference;
 
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.lang.descriptors.TypeParameterDescriptor;
-import org.jetbrains.jet.lang.types.JetType;
 import org.jetbrains.jet.lang.types.Variance;
 
 /**
@@ -11,7 +10,7 @@ import org.jetbrains.jet.lang.types.Variance;
 public interface ConstraintSystem {
     void registerTypeVariable(@NotNull TypeParameterDescriptor typeParameterDescriptor, @NotNull Variance positionVariance);
 
-    void addSubtypingConstraint(@NotNull JetType lower, @NotNull JetType upper);
+    void addSubtypingConstraint(@NotNull SubtypingConstraint constraint);
 
     @NotNull
     ConstraintSystemSolution solve();

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintSystemImpl.java

@@ -143,7 +143,7 @@ public class ConstraintSystemImpl implements ConstraintSystem {
                                 }
                             }
 
-                            listener.log("minimal solution from lowerbounds for " + this + " is " + commonSupertype);
+                            listener.log("minimal solution from lowerbounds for ", this, " is ", commonSupertype);
                             value = new KnownType(commonSupertype);
                         }
                         else {
@@ -247,10 +247,10 @@ public class ConstraintSystemImpl implements ConstraintSystem {
         }
 
         @Override
-        public boolean assertEqualTypes(@NotNull JetType a, @NotNull JetType b, TypeCheckingProcedure typeCheckingProcedure) {
+        public boolean assertEqualTypes(@NotNull JetType a, @NotNull JetType b, @NotNull TypeCheckingProcedure typeCheckingProcedure) {
             boolean result = delegate.assertEqualTypes(a, b, typeCheckingProcedure);
             if (!result) {
-                listener.error("-- Failed to equate " + a + " and " + b);
+                listener.error("-- Failed to equate ", a, " and ", b);
             }
             return result;
         }
@@ -259,16 +259,16 @@ public class ConstraintSystemImpl implements ConstraintSystem {
         public boolean assertEqualTypeConstructors(@NotNull TypeConstructor a, @NotNull TypeConstructor b) {
             boolean result = delegate.assertEqualTypeConstructors(a, b);
             if (!result) {
-                listener.error("-- Type constructors are not equal: " + a + " and " + b);
+                listener.error("-- Type constructors are not equal: ", a, " and ", b);
             }
             return result;
         }
 
         @Override
-        public boolean assertSubtype(@NotNull JetType subtype, @NotNull JetType supertype, TypeCheckingProcedure typeCheckingProcedure) {
+        public boolean assertSubtype(@NotNull JetType subtype, @NotNull JetType supertype, @NotNull TypeCheckingProcedure typeCheckingProcedure) {
             boolean result = delegate.assertSubtype(subtype, supertype, typeCheckingProcedure);
             if (!result) {
-                listener.error("-- " + subtype + " can't be a subtype of " + supertype);
+                listener.error("-- ", subtype, " can't be a subtype of ", supertype);
             }
             return result;
         }
@@ -277,7 +277,7 @@ public class ConstraintSystemImpl implements ConstraintSystem {
         public boolean noCorrespondingSupertype(@NotNull JetType subtype, @NotNull JetType supertype) {
             boolean result = delegate.noCorrespondingSupertype(subtype, supertype);
             if (!result) {
-                listener.error("-- " + subtype + " has no supertype corresponding to " + supertype);
+                listener.error("-- ", subtype, " has no supertype corresponding to ", supertype);
             }
             return result;
         }
@@ -294,7 +294,7 @@ public class ConstraintSystemImpl implements ConstraintSystem {
     private TypeCheckingProcedure createConstraintExpander() {
         return new TypeCheckingProcedure(new TypeConstraintBuilderAdapter(new TypingConstraints() {
             @Override
-            public boolean assertEqualTypes(@NotNull JetType a, @NotNull JetType b, TypeCheckingProcedure typeCheckingProcedure) {
+            public boolean assertEqualTypes(@NotNull JetType a, @NotNull JetType b, @NotNull TypeCheckingProcedure typeCheckingProcedure) {
                 TypeValue aValue = getTypeValueFor(a);
                 TypeValue bValue = getTypeValueFor(b);
 
@@ -309,7 +309,7 @@ public class ConstraintSystemImpl implements ConstraintSystem {
             }
 
             @Override
-            public boolean assertSubtype(@NotNull JetType subtype, @NotNull JetType supertype, TypeCheckingProcedure typeCheckingProcedure) {
+            public boolean assertSubtype(@NotNull JetType subtype, @NotNull JetType supertype, @NotNull TypeCheckingProcedure typeCheckingProcedure) {
                 TypeValue subtypeValue = getTypeValueFor(subtype);
                 TypeValue supertypeValue = getTypeValueFor(supertype);
 
@@ -382,14 +382,14 @@ public class ConstraintSystemImpl implements ConstraintSystem {
     }
 
     @Override
-    public void addSubtypingConstraint(@NotNull JetType lower, @NotNull JetType upper) {
-        TypeValue typeValueForLower = getTypeValueFor(lower);
-        TypeValue typeValueForUpper = getTypeValueFor(upper);
+    public void addSubtypingConstraint(@NotNull SubtypingConstraint constraint) {
+        TypeValue typeValueForLower = getTypeValueFor(constraint.getSubtype());
+        TypeValue typeValueForUpper = getTypeValueFor(constraint.getSupertype());
         addSubtypingConstraintOnTypeValues(typeValueForLower, typeValueForUpper);
     }
 
     private void addSubtypingConstraintOnTypeValues(TypeValue typeValueForLower, TypeValue typeValueForUpper) {
-        listener.log("Constraint added: " + typeValueForLower + " :< " + typeValueForUpper);
+        listener.log("Constraint added: ", typeValueForLower, " :< ", typeValueForUpper);
         if (typeValueForLower != typeValueForUpper) {
             typeValueForLower.addUpperBound(typeValueForUpper);
             typeValueForUpper.addLowerBound(typeValueForLower);
@@ -409,14 +409,22 @@ public class ConstraintSystemImpl implements ConstraintSystem {
                     KnownType knownBoundType = (KnownType) upperBound;
                     boolean ok = constraintExpander.isSubtypeOf(jetType, knownBoundType.getType());
                     if (!ok) {
-                        listener.error("Error while expanding '" + jetType + " :< " + knownBoundType.getType() + "'");
+                        listener.error("Error while expanding '", jetType, " :< ", knownBoundType.getType(), "'");
                         return new Solution().registerError("Mismatch while expanding constraints");
                     }
                 }
             }
 
-            // Lower bounds?
-
+            for (TypeValue lowerBound : typeValue.getLowerBounds()) {
+                if (lowerBound instanceof KnownType) {
+                    KnownType knownBoundType = (KnownType) lowerBound;
+                    boolean ok = constraintExpander.isSubtypeOf(knownBoundType.getType(), jetType);
+                    if (!ok) {
+                        listener.error("Error while expanding '" + knownBoundType.getType() + " :< " + jetType + "'");
+                        return new Solution().registerError("Mismatch while expanding constraints");
+                    }
+                }
+            }
         }
 
         // Fill in upper bounds from type parameter bounds
@@ -435,11 +443,11 @@ public class ConstraintSystemImpl implements ConstraintSystem {
         }
 
         for (UnknownType unknownType : unknownTypes.values()) {
-            listener.constraintsForUnknown(unknownType.getTypeParameterDescriptor(), unknownType);
+//            listener.constraintsForUnknown(unknownType.getTypeParameterDescriptor(), unknownType);
         }
 
         for (KnownType knownType : knownTypes.values()) {
-            listener.constraintsForKnownType(knownType.getType(), knownType);
+//            listener.constraintsForKnownType(knownType.getType(), knownType);
         }
 
         // Find inconsistencies
@@ -469,14 +477,14 @@ public class ConstraintSystemImpl implements ConstraintSystem {
                 JetType boundingType = solution.getSubstitutor().substitute(upperBound.getValue().getType(), Variance.INVARIANT);
                 if (!typeChecker.isSubtypeOf(type, boundingType)) { // TODO
                     solution.registerError("Constraint violation: " + type + " is not a subtype of " + boundingType);
-                    listener.error("Constraint violation: " + type + " :< " + boundingType);
+                    listener.error("Constraint violation: ", type, " :< ", boundingType);
                 }
             }
             for (TypeValue lowerBound : typeValue.getLowerBounds()) {
                 JetType boundingType = solution.getSubstitutor().substitute(lowerBound.getValue().getType(), Variance.INVARIANT);
                 if (!typeChecker.isSubtypeOf(boundingType, type)) {
                     solution.registerError("Constraint violation: " + boundingType + " is not a subtype of " + type);
-                    listener.error("Constraint violation: " + boundingType + " :< " + type);
+                    listener.error("Constraint violation: ", boundingType, " :< ", type);
                 }
             }
         }
@@ -534,7 +542,7 @@ public class ConstraintSystemImpl implements ConstraintSystem {
 
                     TypeProjection typeProjection = new TypeProjection(getValue(descriptor));
 
-                    listener.log(descriptor + " |-> " + typeProjection);
+                    listener.log(descriptor, " |-> ", typeProjection);
 
                     return typeProjection;
                 }

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintSystemWithPriorities.java

@@ -0,0 +1,470 @@
+package org.jetbrains.jet.lang.resolve.calls.inference;
+
+import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.jet.lang.descriptors.DeclarationDescriptor;
+import org.jetbrains.jet.lang.descriptors.TypeParameterDescriptor;
+import org.jetbrains.jet.lang.types.*;
+import org.jetbrains.jet.lang.types.checker.JetTypeChecker;
+import org.jetbrains.jet.lang.types.checker.TypeCheckingProcedure;
+import org.jetbrains.jet.lang.types.checker.TypingConstraints;
+
+import java.util.*;
+
+import static org.jetbrains.jet.lang.resolve.calls.inference.ConstraintType.PARAMETER_BOUND;
+
+/**
+ * @author abreslav
+ */
+public class ConstraintSystemWithPriorities implements ConstraintSystem {
+
+    public static final Comparator<SubtypingConstraint> SUBTYPING_CONSTRAINT_ORDER = new Comparator<SubtypingConstraint>() {
+        @Override
+        public int compare(SubtypingConstraint o1, SubtypingConstraint o2) {
+            return o1.getType().compareTo(o2.getType());
+        }
+    };
+
+    private static class LoopInTypeVariableConstraintsException extends RuntimeException {
+        public LoopInTypeVariableConstraintsException() {}
+    }
+
+    //==========================================================================================================================================================
+
+    private final Map<JetType, TypeValue> knownTypes = Maps.newLinkedHashMap(); // linked - for easier debugging
+    private final Map<TypeParameterDescriptor, TypeValue> unknownTypes = Maps.newLinkedHashMap(); // linked - for easier debugging
+    private final Set<TypeValue> unsolvedUnknowns = Sets.newLinkedHashSet(); // linked - for easier debugging
+    private final PriorityQueue<SubtypingConstraint> constraintQueue = new PriorityQueue<SubtypingConstraint>(10, SUBTYPING_CONSTRAINT_ORDER);
+
+    private final JetTypeChecker typeChecker = JetTypeChecker.INSTANCE;
+    private final TypeCheckingProcedure constraintExpander;
+    private final ConstraintResolutionListener listener;
+
+    public ConstraintSystemWithPriorities(ConstraintResolutionListener listener) {
+        this.listener = listener;
+        this.constraintExpander = createConstraintExpander();
+    }
+
+    @NotNull
+    private TypeValue getTypeValueFor(@NotNull JetType type) {
+        DeclarationDescriptor declarationDescriptor = type.getConstructor().getDeclarationDescriptor();
+        if (declarationDescriptor instanceof TypeParameterDescriptor) {
+            TypeParameterDescriptor typeParameterDescriptor = (TypeParameterDescriptor) declarationDescriptor;
+            // Checking that this is not a T?, but exactly T
+            if (typeParameterDescriptor.getDefaultType().isNullable() == type.isNullable()) {
+                TypeValue unknownType = unknownTypes.get(typeParameterDescriptor);
+                if (unknownType != null) {
+                    return unknownType;
+                }
+            }
+        }
+
+        TypeValue typeValue = knownTypes.get(type);
+        if (typeValue == null) {
+            typeValue = new TypeValue(type);
+            knownTypes.put(type, typeValue);
+        }
+        return typeValue;
+    }
+
+    @Override
+    public void registerTypeVariable(@NotNull TypeParameterDescriptor typeParameterDescriptor, @NotNull Variance positionVariance) {
+        assert !unknownTypes.containsKey(typeParameterDescriptor);
+        TypeValue typeValue = new TypeValue(typeParameterDescriptor, positionVariance);
+        unknownTypes.put(typeParameterDescriptor, typeValue);
+        unsolvedUnknowns.add(typeValue);
+    }
+
+    @NotNull
+    private TypeValue getTypeVariable(TypeParameterDescriptor typeParameterDescriptor) {
+        TypeValue unknownType = unknownTypes.get(typeParameterDescriptor);
+        if (unknownType == null) {
+            throw new IllegalArgumentException("This type parameter is not an unknown in this constraint system: " + typeParameterDescriptor);
+        }
+        return unknownType;
+    }
+
+    @Override
+    public void addSubtypingConstraint(@NotNull SubtypingConstraint constraint) {
+        constraintQueue.add(constraint);
+    }
+
+    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+    // Constraint expansion
+    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+    private TypeCheckingProcedure createConstraintExpander() {
+        return new TypeCheckingProcedure(new TypeConstraintBuilderAdapter(new TypingConstraints() {
+            @Override
+            public boolean assertEqualTypes(@NotNull JetType a, @NotNull JetType b, @NotNull TypeCheckingProcedure typeCheckingProcedure) {
+                TypeValue aValue = getTypeValueFor(a);
+                TypeValue bValue = getTypeValueFor(b);
+
+                return expandEqualityConstraint(aValue, bValue);
+            }
+
+            @Override
+            public boolean assertEqualTypeConstructors(@NotNull TypeConstructor a, @NotNull TypeConstructor b) {
+                return a.equals(b)
+                       || unknownTypes.containsKey(a.getDeclarationDescriptor())
+                       || unknownTypes.containsKey(b.getDeclarationDescriptor());
+            }
+
+            @Override
+            public boolean assertSubtype(@NotNull JetType subtype, @NotNull JetType supertype, @NotNull TypeCheckingProcedure typeCheckingProcedure) {
+                TypeValue subtypeValue = getTypeValueFor(subtype);
+                TypeValue supertypeValue = getTypeValueFor(supertype);
+
+                if (someUnknown(subtypeValue, supertypeValue)) {
+                    expandSubtypingConstraint(subtypeValue, supertypeValue);
+                }
+                return true; // For known types further expansion happens automatically
+            }
+
+            @Override
+            public boolean noCorrespondingSupertype(@NotNull JetType subtype, @NotNull JetType supertype) {
+                // If some of the types is an unknown, the constraint must be generated, and we should carry on
+                // otherwise there can be no solution, and we should fail
+                TypeValue subTypeValue = getTypeValueFor(subtype);
+                TypeValue superTypeValue = getTypeValueFor(supertype);
+                boolean someUnknown = someUnknown(subTypeValue, superTypeValue);
+                if (someUnknown) {
+                    expandSubtypingConstraint(subTypeValue, superTypeValue);
+                }
+                return someUnknown;
+            }
+
+            private boolean someUnknown(TypeValue subtypeValue, TypeValue supertypeValue) {
+                return !subtypeValue.isKnown() || !supertypeValue.isKnown();
+            }
+
+        }, listener));
+    }
+
+    private boolean assignValueTo(TypeValue unknown, JetType value) {
+        if (unknown.hasValue()) {
+            // If we have already assigned a value to this unknown,
+            // it is a conflict to assign another one, unless this new one is equal to the previous
+            return TypeUtils.equalTypes(unknown.getType(), value);
+        }
+        unsolvedUnknowns.remove(unknown);
+        unknown.setValue(value);
+        return true;
+    }
+
+    private boolean mergeUnknowns(@NotNull TypeValue a, @NotNull TypeValue b) {
+        assert !a.isKnown() && !b.isKnown();
+        listener.error("!!!mergeUnknowns() is not implemented!!!");
+        return false;
+    }
+
+    public boolean expandEqualityConstraint(TypeValue a, TypeValue b) {
+        if (a.isKnown() && b.isKnown()) {
+            return constraintExpander.equalTypes(a.getType(), b.getType());            
+        }
+
+        // At least one of them is unknown
+        if (a.isKnown()) {
+            TypeValue tmp = a;
+            a = b;
+            b = tmp;
+        }
+
+        // Now a is definitely unknown
+        if (b.isKnown()) {
+            return assignValueTo(a, b.getType());
+        }
+
+        // They are both unknown
+        return mergeUnknowns(a, b);
+    }
+
+    private boolean expandSubtypingConstraint(TypeValue lower, TypeValue upper) {
+        listener.log("Constraint added: ", lower, " :< ", upper);
+
+        if (lower == upper) return true;
+
+        // Remember for a later check
+        lower.addUpperBound(upper);
+        upper.addLowerBound(lower);
+
+        if (lower.isKnown() && upper.isKnown()) {
+            // Two known types: expand constraints
+            return constraintExpander.isSubtypeOf(lower.getType(), upper.getType());
+        }
+        else if (!lower.isKnown() && !upper.isKnown()) {
+            // Two unknown types: merge them into one variable
+            return mergeUnknowns(lower, upper);
+        }
+        else {
+            // One unknown and one known
+            if (upper.isKnown()) {
+                if (TypeUtils.canHaveSubtypes(typeChecker, upper.getType())) {
+                    // Upper bound is final -> we have to equate the lower bounds to it
+                    return expandEqualityConstraint(lower, upper);
+                }
+                if (lower.getLowerBounds().contains(upper)) {
+                    // upper :< lower :< upper
+                    return expandEqualityConstraint(lower, upper);
+                }
+            }
+            else {
+                if (upper.getUpperBounds().contains(lower)) {
+                    // lower :< upper :< lower
+                    return expandEqualityConstraint(lower, upper);
+                }
+            }
+        }
+        return true;
+    }
+
+    @Override
+    @NotNull
+    public ConstraintSystemSolution solve() {
+        Solution solution = new Solution();
+        // At this point we only have type values, no bounds added for them, no values computed for unknown types
+
+        // Generate low-priority constraints from bounds
+        for (Map.Entry<TypeParameterDescriptor, TypeValue> entry : Sets.newHashSet(unknownTypes.entrySet())) {
+            TypeParameterDescriptor typeParameterDescriptor = entry.getKey();
+            TypeValue typeValue = entry.getValue();
+            for (JetType upperBound : typeParameterDescriptor.getUpperBounds()) {
+                addSubtypingConstraint(PARAMETER_BOUND.assertSubtyping(typeValue.getOriginalType(), getTypeValueFor(upperBound).getOriginalType()));
+            }
+            for (JetType lowerBound : typeParameterDescriptor.getLowerBounds()) {
+                addSubtypingConstraint(PARAMETER_BOUND.assertSubtyping(getTypeValueFor(lowerBound).getOriginalType(), typeValue.getOriginalType()));
+            }
+        }
+
+        // Expand and solve constraints
+        while (!constraintQueue.isEmpty()) {
+            SubtypingConstraint constraint = constraintQueue.poll();
+
+            // Apply constraint
+            TypeValue lower = getTypeValueFor(constraint.getSubtype());
+            TypeValue upper = getTypeValueFor(constraint.getSupertype());
+            boolean success = expandSubtypingConstraint(lower, upper);
+            if (!success) {
+                solution.registerError(constraint.getErrorMessage());
+                break;
+            }
+
+            // (???) Propagate info
+
+            // Any unknowns left?
+            if (unsolvedUnknowns.isEmpty()) break;
+        }
+
+        // Now, let's check the rest of the constraints
+
+        // Expand custom bounds, e.g. List<T> <: List<Int>
+//        for (Map.Entry<JetType, TypeValue> entry : Sets.newHashSet(knownTypes.entrySet())) {
+//            JetType jetType = entry.getKey();
+//            TypeValue typeValue = entry.getValue();
+//
+//            for (TypeValue upperBound : typeValue.getUpperBounds()) {
+//                if (upperBound.isKnown()) {
+//                    boolean ok = constraintExpander.isSubtypeOf(jetType, upperBound.getType());
+//                    if (!ok) {
+//                        listener.error("Error while expanding '" + jetType + " :< " + upperBound.getType() + "'");
+//                        return new Solution().registerError("Mismatch while expanding constraints");
+//                    }
+//                }
+//            }
+//
+//            // Lower bounds. Probably not needed for known types, as everything is symmetrical anyway
+//        }
+
+        // effective bounds for each node
+//        Set<TypeValue> visited = Sets.newHashSet();
+//        for (TypeValue unknownType : unknownTypes.values()) {
+//            transitiveClosure(unknownType, visited);
+//        }
+
+        for (TypeValue unknownType : unknownTypes.values()) {
+            listener.constraintsForUnknown(unknownType.getTypeParameterDescriptor(), unknownType);
+        }
+        for (TypeValue knownType : knownTypes.values()) {
+            listener.constraintsForKnownType(knownType.getType(), knownType);
+        }
+
+        // Find inconsistencies
+
+        // Compute values and check that all bounds are respected by solutions:
+        // we have set some of them from equality constraints with known types
+        // and thus the bounds may be violated if some of the constraints conflict
+        for (TypeValue unknownType : unknownTypes.values()) {
+            check(unknownType, solution);
+        }
+        for (TypeValue knownType : knownTypes.values()) {
+            check(knownType, solution);
+        }
+
+        listener.done(solution, unknownTypes.keySet());
+
+        return solution;
+    }
+
+    private void transitiveClosure(TypeValue current, Set<TypeValue> visited) {
+        if (!visited.add(current)) {
+            return;
+        }
+
+        for (TypeValue upperBound : Sets.newHashSet(current.getUpperBounds())) {
+            if (upperBound.isKnown()) {
+                continue;
+            }
+            transitiveClosure(upperBound, visited);
+            Set<TypeValue> upperBounds = upperBound.getUpperBounds();
+            for (TypeValue transitiveBound : upperBounds) {
+                expandSubtypingConstraint(current, transitiveBound);
+            }
+        }
+    }
+
+    private void check(TypeValue typeValue, Solution solution) {
+        try {
+            JetType resultingType = typeValue.getType();
+            JetType type = solution.getSubstitutor().substitute(resultingType, Variance.INVARIANT); // TODO
+            for (TypeValue upperBound : typeValue.getUpperBounds()) {
+                JetType boundingType = solution.getSubstitutor().substitute(upperBound.getType(), Variance.INVARIANT);
+                if (!typeChecker.isSubtypeOf(type, boundingType)) { // TODO
+                    solution.registerError("Constraint violation: " + type + " is not a subtype of " + boundingType);
+                    listener.error("Constraint violation: ", type, " :< ", boundingType);
+                }
+            }
+            for (TypeValue lowerBound : typeValue.getLowerBounds()) {
+                JetType boundingType = solution.getSubstitutor().substitute(lowerBound.getType(), Variance.INVARIANT);
+                if (!typeChecker.isSubtypeOf(boundingType, type)) {
+                    solution.registerError("Constraint violation: " + boundingType + " is not a subtype of " + type);
+                    listener.error("Constraint violation: ", boundingType, " :< ", type);
+                }
+            }
+        }
+        catch (LoopInTypeVariableConstraintsException e) {
+            listener.error("Loop detected");
+            solution.registerError("[TODO] Loop in constraints");
+        }
+    }
+
+    private static class Error implements SolutionStatus {
+
+        private final String message;
+
+        private Error(String message) {
+            this.message = message;
+        }
+
+        @Override
+        public boolean isSuccessful() {
+            return false;
+        }
+
+        @Override
+        public String toString() {
+            return message;
+        }
+    }
+
+    public class Solution implements ConstraintSystemSolution {
+        private final TypeSubstitutor typeSubstitutor = TypeSubstitutor.create(new TypeSubstitutor.TypeSubstitution() {
+            @Override
+            public TypeProjection get(TypeConstructor key) {
+                DeclarationDescriptor declarationDescriptor = key.getDeclarationDescriptor();
+                if (declarationDescriptor instanceof TypeParameterDescriptor) {
+                    TypeParameterDescriptor descriptor = (TypeParameterDescriptor) declarationDescriptor;
+
+                    if (!unknownTypes.containsKey(descriptor)) return null;
+
+                    TypeProjection typeProjection = new TypeProjection(getValue(descriptor));
+
+                    listener.log(descriptor, " |-> ", typeProjection);
+
+                    return typeProjection;
+                }
+                return null;
+            }
+
+            @Override
+            public boolean isEmpty() {
+                return false;
+            }
+        });
+
+        private SolutionStatus status;
+
+        public Solution() {
+            this.status = SolutionStatus.SUCCESS;
+        }
+
+        private Solution registerError(String message) {
+            status = new Error(message);
+            return this;
+        }
+
+        @NotNull
+        @Override
+        public SolutionStatus getStatus() {
+            return status;
+        }
+
+        @Override
+        public JetType getValue(TypeParameterDescriptor typeParameterDescriptor) {
+            return getTypeVariable(typeParameterDescriptor).getType();
+        }
+
+        @NotNull
+        @Override
+        public TypeSubstitutor getSubstitutor() {
+            return typeSubstitutor;
+        }
+
+    }
+    private static final class TypeConstraintBuilderAdapter implements TypingConstraints {
+        private final TypingConstraints delegate;
+        private final ConstraintResolutionListener listener;
+
+        private TypeConstraintBuilderAdapter(TypingConstraints delegate, ConstraintResolutionListener listener) {
+            this.delegate = delegate;
+            this.listener = listener;
+        }
+
+        @Override
+        public boolean assertEqualTypes(@NotNull JetType a, @NotNull JetType b, @NotNull TypeCheckingProcedure typeCheckingProcedure) {
+            boolean result = delegate.assertEqualTypes(a, b, typeCheckingProcedure);
+            if (!result) {
+                listener.error("-- Failed to equate ", a, " and ", b);
+            }
+            return result;
+        }
+
+        @Override
+        public boolean assertEqualTypeConstructors(@NotNull TypeConstructor a, @NotNull TypeConstructor b) {
+            boolean result = delegate.assertEqualTypeConstructors(a, b);
+            if (!result) {
+                listener.error("-- Type constructors are not equal: ", a, " and ", b);
+            }
+            return result;
+        }
+
+        @Override
+        public boolean assertSubtype(@NotNull JetType subtype, @NotNull JetType supertype, @NotNull TypeCheckingProcedure typeCheckingProcedure) {
+            boolean result = delegate.assertSubtype(subtype, supertype, typeCheckingProcedure);
+            if (!result) {
+                listener.error("-- " + subtype + " can't be a subtype of " + supertype);
+            }
+            return result;
+        }
+
+        @Override
+        public boolean noCorrespondingSupertype(@NotNull JetType subtype, @NotNull JetType supertype) {
+            boolean result = delegate.noCorrespondingSupertype(subtype, supertype);
+            if (!result) {
+                listener.error("-- " + subtype + " has no supertype corresponding to " + supertype);
+            }
+            return result;
+        }
+    }
+
+}

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintType.java

@@ -0,0 +1,35 @@
+package org.jetbrains.jet.lang.resolve.calls.inference;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.jet.lang.types.JetType;
+
+import java.text.MessageFormat;
+
+/**
+ * @author abreslav
+ */
+public enum ConstraintType implements Comparable<ConstraintType> {
+    // The order of these constants DOES matter
+    // they are compared according to ordinal() values
+    // First element has the highest priority
+    RECEIVER("{0} is not a subtype of the expected receiver type {1}"),
+    VALUE_ARGUMENT("Type mismatch: argument type is {0}, but {1} was expected"),
+    EXPECTED_TYPE("Resulting type is {0} but {1} was expected"),
+    PARAMETER_BOUND("Type parameter bound is not satisfied: {0} is not a subtype of {1}");
+
+    private final String errorMessageTemplate; // {0} is subtype, {1} is supertye
+
+    private ConstraintType(@NotNull String errorMessageTemplate) {
+        this.errorMessageTemplate = errorMessageTemplate;
+    }
+
+    @NotNull
+    public SubtypingConstraint assertSubtyping(@NotNull JetType subtype, @NotNull JetType supertype) {
+        return new SubtypingConstraint(this, subtype, supertype);
+    }
+
+    @NotNull
+    public String makeErrorMessage(@NotNull SubtypingConstraint constraint) {
+        return MessageFormat.format(errorMessageTemplate, constraint.getSubtype(), constraint.getSupertype());
+    }
+}

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/DebugConstraintResolutionListener.java

@@ -23,9 +23,9 @@ public class DebugConstraintResolutionListener implements ConstraintResolutionLi
     }
 
     @Override
-    public void constraintsForUnknown(TypeParameterDescriptor typeParameterDescriptor, ConstraintSystemImpl.TypeValue typeValue) {
+    public void constraintsForUnknown(TypeParameterDescriptor typeParameterDescriptor, BoundsOwner typeValue) {
         if (!ResolutionDebugInfo.isResolutionDebugEnabled()) return;
-        Map<TypeParameterDescriptor, ConstraintSystemImpl.TypeValue> map = debugInfo.get(BOUNDS_FOR_UNKNOWNS);
+        Map<TypeParameterDescriptor, BoundsOwner> map = debugInfo.get(BOUNDS_FOR_UNKNOWNS);
         if (map == null) {
             map = Maps.newLinkedHashMap();
             debugInfo.set(BOUNDS_FOR_UNKNOWNS, map);
@@ -34,9 +34,9 @@ public class DebugConstraintResolutionListener implements ConstraintResolutionLi
     }
 
     @Override
-    public void constraintsForKnownType(JetType type, ConstraintSystemImpl.TypeValue typeValue) {
+    public void constraintsForKnownType(JetType type, BoundsOwner typeValue) {
         if (!ResolutionDebugInfo.isResolutionDebugEnabled()) return;
-        Map<JetType,ConstraintSystemImpl.TypeValue> map = debugInfo.get(BOUNDS_FOR_KNOWNS);
+        Map<JetType,BoundsOwner> map = debugInfo.get(BOUNDS_FOR_KNOWNS);
         if (map == null) {
             map = Maps.newLinkedHashMap();
             debugInfo.set(BOUNDS_FOR_KNOWNS, map);
@@ -52,24 +52,30 @@ public class DebugConstraintResolutionListener implements ConstraintResolutionLi
     }
 
     @Override
-    public void log(Object message) {
+    public void log(Object... messageFragments) {
         if (!ResolutionDebugInfo.isResolutionDebugEnabled()) return;
         StringBuilder stringBuilder = debugInfo.get(LOG);
         if (stringBuilder == null) {
             stringBuilder = new StringBuilder();
             debugInfo.set(LOG, stringBuilder);
         }
-        stringBuilder.append(message).append("\n");
+        for (Object m : messageFragments) {
+            stringBuilder.append(m);
+        }
+        stringBuilder.append("\n");
     }
 
     @Override
-    public void error(Object message) {
+    public void error(Object... messageFragments) {
         if (!ResolutionDebugInfo.isResolutionDebugEnabled()) return;
         StringBuilder stringBuilder = debugInfo.get(ERRORS);
         if (stringBuilder == null) {
             stringBuilder = new StringBuilder();
             debugInfo.set(ERRORS, stringBuilder);
         }
-        stringBuilder.append(message).append("\n");
+        for (Object m : messageFragments) {
+            stringBuilder.append(m);
+        }
+        stringBuilder.append("\n");
     }
 }

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/PrintingConstraintResolutionListener.java

@@ -12,13 +12,13 @@ import java.util.Set;
 public class PrintingConstraintResolutionListener implements ConstraintResolutionListener {
 
     @Override
-    public void constraintsForUnknown(TypeParameterDescriptor typeParameterDescriptor, ConstraintSystemImpl.TypeValue typeValue) {
+    public void constraintsForUnknown(TypeParameterDescriptor typeParameterDescriptor, BoundsOwner typeValue) {
         println("Constraints for " + typeParameterDescriptor);
         printTypeValue(typeValue);
     }
 
     @Override
-    public void constraintsForKnownType(JetType type, ConstraintSystemImpl.TypeValue typeValue) {
+    public void constraintsForKnownType(JetType type, BoundsOwner typeValue) {
         println("Constraints for " + type);
         printTypeValue(typeValue);
     }
@@ -31,20 +31,24 @@ public class PrintingConstraintResolutionListener implements ConstraintResolutio
     }
 
     @Override
-    public void log(Object message) {
-        println(message);
+    public void log(Object... messageFragments) {
+        for (Object fragment : messageFragments) {
+            println(fragment);
+        }
     }
 
     @Override
-    public void error(Object message) {
-        println(message);
+    public void error(Object... messageFragments) {
+        for (Object fragment : messageFragments) {
+            println(fragment);
+        }
     }
 
-    private void printTypeValue(ConstraintSystemImpl.TypeValue typeValue) {
-        for (ConstraintSystemImpl.TypeValue bound : typeValue.getUpperBounds()) {
+    private void printTypeValue(BoundsOwner typeValue) {
+        for (BoundsOwner bound : typeValue.getUpperBounds()) {
             println(" :< " + bound);
         }
-        for (ConstraintSystemImpl.TypeValue bound : typeValue.getLowerBounds()) {
+        for (BoundsOwner bound : typeValue.getLowerBounds()) {
             println(" :> " + bound);
         }
     }

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/SubtypingConstraint.java

@@ -0,0 +1,39 @@
+package org.jetbrains.jet.lang.resolve.calls.inference;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.jet.lang.types.JetType;
+
+/**
+ * @author abreslav
+ */
+public class SubtypingConstraint {
+    private final ConstraintType type;
+    private final JetType subtype;
+    private final JetType supertype;
+
+    public SubtypingConstraint(@NotNull ConstraintType type, @NotNull JetType subtype, @NotNull JetType supertype) {
+        this.type = type;
+        this.subtype = subtype;
+        this.supertype = supertype;
+    }
+
+    @NotNull
+    public JetType getSubtype() {
+        return subtype;
+    }
+
+    @NotNull
+    public JetType getSupertype() {
+        return supertype;
+    }
+
+    @NotNull
+    public ConstraintType getType() {
+        return type;
+    }
+
+    @NotNull
+    public String getErrorMessage() {
+        return type.makeErrorMessage(this);
+    }
+}

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/TypeValue.java

@@ -0,0 +1,82 @@
+package org.jetbrains.jet.lang.resolve.calls.inference;
+
+import com.google.common.collect.Sets;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.jet.lang.descriptors.TypeParameterDescriptor;
+import org.jetbrains.jet.lang.types.JetType;
+import org.jetbrains.jet.lang.types.Variance;
+
+import java.util.Set;
+
+/**
+* @author abreslav
+*/
+public class TypeValue implements BoundsOwner {
+    private final Set<TypeValue> upperBounds = Sets.newLinkedHashSet();
+    private final Set<TypeValue> lowerBounds = Sets.newLinkedHashSet();
+
+    private final Variance positionVariance;
+    private final TypeParameterDescriptor typeParameterDescriptor; // Null for known types
+    private final JetType originalType;
+    private JetType value; // For an unknown — the value found by constraint resolution, for a known — just it's value
+
+    // Unknown type
+    public TypeValue(@NotNull TypeParameterDescriptor typeParameterDescriptor, @NotNull Variance positionVariance) {
+        this.positionVariance = positionVariance;
+        this.typeParameterDescriptor = typeParameterDescriptor;
+        this.originalType = typeParameterDescriptor.getDefaultType();
+    }
+
+    // Known type
+    public TypeValue(@NotNull JetType knownType) {
+        this.positionVariance = null;
+        this.typeParameterDescriptor = null;
+        this.originalType = knownType;
+    }
+
+    public boolean isKnown() {
+        return typeParameterDescriptor == null;
+    }
+
+    public TypeParameterDescriptor getTypeParameterDescriptor() {
+        return typeParameterDescriptor;
+    }
+
+    @Override
+    @NotNull
+    public Set<TypeValue> getUpperBounds() {
+        return upperBounds;
+    }
+
+    @Override
+    @NotNull
+    public Set<TypeValue> getLowerBounds() {
+        return lowerBounds;
+    }
+
+    @NotNull
+    public JetType getType() {
+        return value;
+    }
+
+    @NotNull
+    public JetType getOriginalType() {
+        return originalType;
+    }
+
+    public void addUpperBound(@NotNull TypeValue bound) {
+        upperBounds.add(bound);
+    }
+
+    public void addLowerBound(@NotNull TypeValue bound) {
+        lowerBounds.add(bound);
+    }
+
+    public void setValue(@NotNull JetType value) {
+        this.value = value;
+    }
+
+    public boolean hasValue() {
+        return value != null;
+    }
+}

compiler/frontend/src/org/jetbrains/jet/lang/types/ErrorUtils.java

@@ -203,7 +203,7 @@ public class ErrorUtils {
     }
 
     public static boolean isError(@NotNull DeclarationDescriptor candidate) {
-        return candidate.getContainingDeclaration() == getErrorClass() || candidate == ERROR_MODULE;
+        return candidate == getErrorClass() || candidate.getContainingDeclaration() == getErrorClass() || candidate == ERROR_MODULE;
     }
 
     private static class ErrorTypeImpl implements JetType {

compiler/frontend/src/org/jetbrains/jet/lang/types/TypeSubstitutor.java

@@ -1,19 +1,41 @@
 package org.jetbrains.jet.lang.types;
 
+import com.google.common.collect.Sets;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.lang.descriptors.TypeParameterDescriptor;
 import org.jetbrains.jet.lang.resolve.scopes.SubstitutingScope;
 
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 
 /**
  * @author abreslav
  */
 public class TypeSubstitutor {
 
+    public static TypeSubstitutor makeConstantSubstitutor(Collection<TypeParameterDescriptor> typeParameterDescriptors, JetType type) {
+        final Set<TypeConstructor> constructors = Sets.newHashSet();
+        for (TypeParameterDescriptor typeParameterDescriptor : typeParameterDescriptors) {
+            constructors.add(typeParameterDescriptor.getTypeConstructor());
+        }
+        final TypeProjection projection = new TypeProjection(type);
+
+        return create(new TypeSubstitution() {
+            @Override
+            public TypeProjection get(TypeConstructor key) {
+                if (constructors.contains(key)) {
+                    return projection;
+                }
+                return null;
+            }
+
+            @Override
+            public boolean isEmpty() {
+                return false;
+            }
+        });
+    }
+
     public interface TypeSubstitution {
         TypeSubstitution EMPTY = new TypeSubstitution() {
             @Override

compiler/frontend/src/org/jetbrains/jet/lang/types/checker/JetTypeChecker.java

@@ -46,7 +46,7 @@ public class JetTypeChecker {
 
     private static class TypeCheckerTypingConstraints implements TypingConstraints {
         @Override
-        public boolean assertEqualTypes(@NotNull JetType a, @NotNull JetType b, TypeCheckingProcedure typeCheckingProcedure) {
+        public boolean assertEqualTypes(@NotNull JetType a, @NotNull JetType b, @NotNull TypeCheckingProcedure typeCheckingProcedure) {
             return typeCheckingProcedure.equalTypes(a, b);
 //            return TypeUtils.equalTypes(a, b);
         }
@@ -57,7 +57,7 @@ public class JetTypeChecker {
         }
 
         @Override
-        public boolean assertSubtype(@NotNull JetType subtype, @NotNull JetType supertype, TypeCheckingProcedure typeCheckingProcedure) {
+        public boolean assertSubtype(@NotNull JetType subtype, @NotNull JetType supertype, @NotNull TypeCheckingProcedure typeCheckingProcedure) {
             return typeCheckingProcedure.isSubtypeOf(subtype, supertype);
         }
 

compiler/frontend/src/org/jetbrains/jet/lang/types/checker/TypingConstraints.java

@@ -8,11 +8,11 @@ import org.jetbrains.jet.lang.types.TypeConstructor;
  * Methods of this class return true to continue type checking and false to fail
  */
 public interface TypingConstraints {
-    boolean assertEqualTypes(@NotNull JetType a, @NotNull JetType b, TypeCheckingProcedure typeCheckingProcedure);
+    boolean assertEqualTypes(@NotNull JetType a, @NotNull JetType b, @NotNull TypeCheckingProcedure typeCheckingProcedure);
 
     boolean assertEqualTypeConstructors(@NotNull TypeConstructor a, @NotNull TypeConstructor b);
 
-    boolean assertSubtype(@NotNull JetType subtype, @NotNull JetType supertype, TypeCheckingProcedure typeCheckingProcedure);
+    boolean assertSubtype(@NotNull JetType subtype, @NotNull JetType supertype, @NotNull TypeCheckingProcedure typeCheckingProcedure);
 
     boolean noCorrespondingSupertype(@NotNull JetType subtype, @NotNull JetType supertype);
 }

compiler/testData/codegen/inputStreamIterator.jet

@@ -1,3 +1,4 @@
+import std.*
 import std.io.*
 
 import java.io.*

compiler/testData/codegen/regressions/kt259.jet

@@ -1,4 +1,5 @@
 class A() {}
+
 open class B<T>() {
     fun isT (a : Any?) : Boolean {
         return a is T
@@ -167,7 +168,6 @@ fun t26 () : Boolean {
 }
 
 fun box() : String {
-/*
     if(!t1()) {
         return "t1 failed"
     }
@@ -243,7 +243,6 @@ fun box() : String {
      if(!t25()) {
          return "t25 failed"
      }
-     */
      if(!t26()) {
          return "t26 failed"
      }

compiler/testData/codegen/regressions/kt785.jet

@@ -0,0 +1,13 @@
+class A() {
+    var x : Int = 0
+
+    var z = { () =>
+        x++
+    }
+}
+
+fun box() : String {
+    val a = A()
+    a.z()  //problem is here
+    return if (a.x == 1) "OK" else "fail"
+}

compiler/testData/codegen/regressions/kt796_797.jet

@@ -0,0 +1,8 @@
+fun <T> Array<T>?.get(i : Int?) = this.sure().get(i.sure())
+fun <T> array(vararg t : T) : Array<T> = t
+
+fun box() : String {
+    val a : Array<String>? = array<String>("Str", "Str2")
+    val i : Int? = 1
+    return if(a[i] == "Str2") "OK" else "fail"
+}

compiler/testData/codegen/typeInfo/inheritance.jet

@@ -1,4 +1,4 @@
-open class A<T> () {
+open class A<out T> () {
    fun plus(e: T) = B<T> (e)
 }
 
@@ -6,4 +6,6 @@ class B<T> (val e: T) : A<T>() {
    fun add() = B<T> (e)
 }
 
-fun box() = if( A<String>().plus("239").add().e == "239" ) "OK" else "fail"
+fun box() : String {
+    return if(A<String>().plus("239").add().e == "239" ) "OK" else "fail"
+}

compiler/testData/codegen/typeInfo/inner.jet

@@ -4,7 +4,6 @@ class Box<T>() {
     }
 
     class Inner2() : Inner() {
-
     }
 
     fun inner() = Inner2()

compiler/testData/compileJavaAgainstKotlin/class/ExtendsAbstractListT.java

@@ -0,0 +1,6 @@
+class ExtendsAbstractListT {
+    {
+        Mine<String> mine = null;
+        java.util.List<String> list = mine;
+    }
+}

compiler/testData/compileJavaAgainstKotlin/class/ExtendsAbstractListT.kt

@@ -0,0 +1 @@
+abstract class Mine<T>() : java.util.AbstractList<T>()

compiler/testData/compileJavaAgainstKotlin/class/ImplementsListString.java

@@ -0,0 +1,7 @@
+
+class PlainExtendsListString {
+    {
+        Mine mine = null;
+        java.util.List<String> list = mine;
+    }
+}

compiler/testData/compileJavaAgainstKotlin/class/ImplementsListString.kt

@@ -0,0 +1 @@
+abstract class Mine : java.util.List<String>

compiler/testData/compileJavaAgainstKotlin/class/ImplementsMapPP.java

@@ -0,0 +1,7 @@
+
+class ImplementsMapPP {
+    {
+        Mine<String, Integer> mine = null;
+        java.util.Map<Integer, String> map = mine;
+    }
+}

compiler/testData/compileJavaAgainstKotlin/class/ImplementsMapPP.kt

@@ -0,0 +1 @@
+abstract class Mine<P1, P2> : java.util.Map<P2, P1>

compiler/testData/compileJavaAgainstKotlin/method/QExtendsListString.java

@@ -0,0 +1,8 @@
+
+class Question {
+    // id2 is to prevent java type parameter type inference
+    static <T> T id2(T p) { return p; }
+    {
+        java.util.List<String> s = id2(namespace.id((jet.typeinfo.TypeInfo) null, null));
+    }
+}

compiler/testData/compileJavaAgainstKotlin/method/QExtendsListString.kt

@@ -0,0 +1,3 @@
+import java.util.List
+
+fun <P1 : List<String>> id(p: P1) = p

compiler/testData/compileJavaAgainstKotlin/method/QExtendsString.java

@@ -0,0 +1,8 @@
+
+class Question {
+    // id2 is to prevent java type parameter type inference
+    static <T> T id2(T p) { return p; }
+    {
+        String s = id2(namespace.id((jet.typeinfo.TypeInfo) null, null));
+    }
+}

compiler/testData/compileJavaAgainstKotlin/method/QExtendsString.kt

@@ -0,0 +1 @@
+fun <T : String> id(p: T) = p

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

@@ -24,7 +24,7 @@ public class ClassGenTest extends CodegenTestCase {
 
     public void testArrayListInheritance() throws Exception {
         loadFile("classes/inheritingFromArrayList.jet");
-
+        System.out.println(generateToText());
         final Class aClass = loadClass("Foo", generateClassesInFile());
         assertInstanceOf(aClass.newInstance(), List.class);
     }

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

@@ -81,6 +81,10 @@ public class FunctionGenTest extends CodegenTestCase {
         blackBoxFile("regressions/kt395.jet");
     }
 
+    public void testKt785 () {
+//        blackBoxFile("regressions/kt785.jet");
+    }
+
     public void testFunction () throws InvocationTargetException, IllegalAccessException {
         blackBoxFile("functions/functionExpression.jet");
     }

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

@@ -140,7 +140,7 @@ public class TypeInfoTest extends CodegenTestCase {
 
     public void testInner() throws Exception {
         blackBoxFile("typeInfo/inner.jet");
-//        System.out.println(generateToText());
+        System.out.println(generateToText());
     }
 
     public void testInheritance() throws Exception {
@@ -148,4 +148,3 @@ public class TypeInfoTest extends CodegenTestCase {
         System.out.println(generateToText());
     }
 }
-

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

@@ -74,4 +74,8 @@ public class VarArgTest extends CodegenTestCase {
         createEnvironmentWithFullJdk();
         blackBoxFile("regressions/kt581.jet");
     }
+
+    public void testKt797() {
+        blackBoxFile("regressions/kt796_797.jet");
+    }
 }