001    /*
002     * Copyright 2010-2013 JetBrains s.r.o.
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     * http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    
017    package org.jetbrains.jet.codegen;
018    
019    import com.intellij.openapi.progress.ProcessCanceledException;
020    import com.intellij.psi.PsiElement;
021    import org.jetbrains.annotations.NotNull;
022    import org.jetbrains.annotations.Nullable;
023    import org.jetbrains.asm4.AnnotationVisitor;
024    import org.jetbrains.asm4.Label;
025    import org.jetbrains.asm4.MethodVisitor;
026    import org.jetbrains.asm4.Type;
027    import org.jetbrains.asm4.commons.InstructionAdapter;
028    import org.jetbrains.asm4.commons.Method;
029    import org.jetbrains.jet.codegen.binding.CodegenBinding;
030    import org.jetbrains.jet.codegen.context.CodegenContext;
031    import org.jetbrains.jet.codegen.context.MethodContext;
032    import org.jetbrains.jet.codegen.signature.JvmMethodParameterKind;
033    import org.jetbrains.jet.codegen.signature.JvmMethodParameterSignature;
034    import org.jetbrains.jet.codegen.signature.JvmMethodSignature;
035    import org.jetbrains.jet.codegen.signature.JvmPropertyAccessorSignature;
036    import org.jetbrains.jet.codegen.signature.kotlin.JetMethodAnnotationWriter;
037    import org.jetbrains.jet.codegen.signature.kotlin.JetValueParameterAnnotationWriter;
038    import org.jetbrains.jet.codegen.state.GenerationState;
039    import org.jetbrains.jet.codegen.state.GenerationStateAware;
040    import org.jetbrains.jet.codegen.state.JetTypeMapper;
041    import org.jetbrains.jet.codegen.state.JetTypeMapperMode;
042    import org.jetbrains.jet.lang.descriptors.*;
043    import org.jetbrains.jet.lang.psi.JetNamedFunction;
044    import org.jetbrains.jet.lang.resolve.BindingContext;
045    import org.jetbrains.jet.lang.resolve.java.JvmAbi;
046    import org.jetbrains.jet.lang.resolve.java.JvmClassName;
047    import org.jetbrains.jet.lang.resolve.java.JvmStdlibNames;
048    import org.jetbrains.jet.lang.resolve.java.kt.DescriptorKindUtils;
049    import org.jetbrains.jet.lang.resolve.name.Name;
050    
051    import java.util.*;
052    
053    import static org.jetbrains.asm4.Opcodes.*;
054    import static org.jetbrains.jet.codegen.AsmUtil.*;
055    import static org.jetbrains.jet.codegen.CodegenUtil.*;
056    import static org.jetbrains.jet.codegen.binding.CodegenBinding.isLocalNamedFun;
057    import static org.jetbrains.jet.lang.resolve.BindingContextUtils.callableDescriptorToDeclaration;
058    import static org.jetbrains.jet.lang.resolve.BindingContextUtils.descriptorToDeclaration;
059    import static org.jetbrains.jet.lang.resolve.DescriptorUtils.isFunctionLiteral;
060    import static org.jetbrains.jet.lang.resolve.java.AsmTypeConstants.OBJECT_TYPE;
061    
062    public class FunctionCodegen extends GenerationStateAware {
063        private final CodegenContext owner;
064        private final ClassBuilder v;
065    
066        public FunctionCodegen(CodegenContext owner, ClassBuilder v, GenerationState state) {
067            super(state);
068            this.owner = owner;
069            this.v = v;
070        }
071    
072        public void gen(@NotNull JetNamedFunction function) {
073            SimpleFunctionDescriptor functionDescriptor = bindingContext.get(BindingContext.FUNCTION, function);
074            assert functionDescriptor != null;
075    
076            OwnerKind kind = owner.getContextKind();
077            JvmMethodSignature method = typeMapper.mapSignature(functionDescriptor, true, kind);
078    
079            if (kind != OwnerKind.TRAIT_IMPL || function.getBodyExpression() != null) {
080                boolean needJetAnnotations = kind != OwnerKind.TRAIT_IMPL;
081                generateMethod(function, method, needJetAnnotations, functionDescriptor,
082                               new FunctionGenerationStrategy.FunctionDefault(state, functionDescriptor, function));
083            }
084    
085            generateDefaultIfNeeded(owner.intoFunction(functionDescriptor), state, v, method, functionDescriptor, kind,
086                                    DefaultParameterValueLoader.DEFAULT);
087        }
088    
089        public void generateMethod(
090                @Nullable PsiElement origin,
091                @NotNull JvmMethodSignature jvmSignature,
092                boolean needJetAnnotations,
093                @NotNull FunctionDescriptor functionDescriptor,
094                @NotNull FunctionGenerationStrategy strategy
095        ) {
096            generateMethod(origin, jvmSignature, needJetAnnotations, functionDescriptor, owner.intoFunction(functionDescriptor), strategy);
097        }
098    
099        public void generateMethod(
100                @Nullable PsiElement origin,
101                @NotNull JvmMethodSignature jvmSignature,
102                boolean needJetAnnotations,
103                @NotNull FunctionDescriptor functionDescriptor,
104                @NotNull MethodContext methodContext,
105                @NotNull FunctionGenerationStrategy strategy
106        ) {
107    
108            Method asmMethod = jvmSignature.getAsmMethod();
109    
110            MethodVisitor mv = v.newMethod(origin,
111                                           getMethodAsmFlags(functionDescriptor, methodContext.getContextKind()),
112                                           asmMethod.getName(),
113                                           asmMethod.getDescriptor(),
114                                           jvmSignature.getGenericsSignature(),
115                                           null);
116    
117            AnnotationCodegen.forMethod(mv, typeMapper).genAnnotations(functionDescriptor);
118            if (state.getClassBuilderMode() == ClassBuilderMode.SIGNATURES) return;
119    
120            if (needJetAnnotations) {
121                genJetAnnotations(mv, functionDescriptor, jvmSignature);
122            }
123    
124            if (isAbstractMethod(functionDescriptor, methodContext.getContextKind())) return;
125    
126            if (state.getClassBuilderMode() == ClassBuilderMode.STUBS) {
127                genStubCode(mv);
128                return;
129            }
130    
131            generateMethodBody(mv, functionDescriptor, methodContext, jvmSignature, strategy);
132    
133            endVisit(mv, null, origin);
134    
135            generateBridgeIfNeeded(owner, state, v, jvmSignature.getAsmMethod(), functionDescriptor);
136    
137            methodContext.recordSyntheticAccessorIfNeeded(functionDescriptor, typeMapper);
138        }
139    
140        @Nullable
141        private Type getThisTypeForFunction(@NotNull FunctionDescriptor functionDescriptor, @NotNull MethodContext context) {
142            ReceiverParameterDescriptor expectedThisObject = functionDescriptor.getExpectedThisObject();
143            if (functionDescriptor instanceof ConstructorDescriptor) {
144                return typeMapper.mapType(functionDescriptor.getReturnType());
145            }
146            else if (expectedThisObject != null) {
147                return typeMapper.mapType(expectedThisObject.getType());
148            }
149            else if (isFunctionLiteral(functionDescriptor) || isLocalNamedFun(functionDescriptor)) {
150                return typeMapper.mapType(context.getThisDescriptor());
151            }
152            else {
153                return null;
154            }
155        }
156    
157        private void generateMethodBody(
158                @NotNull MethodVisitor mv,
159                @NotNull FunctionDescriptor functionDescriptor,
160                @NotNull MethodContext context,
161                @NotNull JvmMethodSignature signature,
162                @NotNull FunctionGenerationStrategy strategy
163        ) {
164            Collection<String> localVariableNames = new HashSet<String>(getParameterNamesAsStrings(functionDescriptor));
165    
166            Map<Name, Label> labelsForSharedVars = new HashMap<Name, Label>();
167    
168            mv.visitCode();
169    
170            Label methodBegin = new Label();
171            mv.visitLabel(methodBegin);
172    
173            OwnerKind kind = context.getContextKind();
174            if (kind instanceof OwnerKind.StaticDelegateKind) {
175                generateStaticDelegateMethodBody(mv, signature.getAsmMethod(), (OwnerKind.StaticDelegateKind) kind);
176            }
177            else {
178                FrameMap frameMap = strategy.getFrameMap(typeMapper, context);
179    
180                for (ValueParameterDescriptor parameter : functionDescriptor.getValueParameters()) {
181                    frameMap.enter(parameter, typeMapper.mapType(parameter));
182                }
183    
184                labelsForSharedVars.putAll(createSharedVarsForParameters(mv, functionDescriptor, frameMap));
185    
186                if (!JetTypeMapper.isAccessor(functionDescriptor)) {
187                    genNotNullAssertionsForParameters(new InstructionAdapter(mv), state, functionDescriptor, frameMap);
188                }
189    
190                strategy.generateBody(mv, signature, context);
191    
192                localVariableNames.addAll(strategy.getLocalVariableNames());
193            }
194    
195            Label methodEnd = new Label();
196            mv.visitLabel(methodEnd);
197    
198    
199            Type thisType = getThisTypeForFunction(functionDescriptor, context);
200            generateLocalVariableTable(mv, signature, functionDescriptor, thisType, methodBegin, methodEnd, localVariableNames, labelsForSharedVars, kind);
201        }
202    
203        @NotNull
204        private static List<String> getParameterNamesAsStrings(@NotNull FunctionDescriptor functionDescriptor) {
205            List<ValueParameterDescriptor> parameters = functionDescriptor.getValueParameters();
206            List<String> result = new ArrayList<String>(parameters.size());
207            for (ValueParameterDescriptor parameter : parameters) {
208                result.add(parameter.getName().asString());
209            }
210            return result;
211        }
212    
213        private void generateLocalVariableTable(
214                @NotNull MethodVisitor mv,
215                @NotNull JvmMethodSignature jvmMethodSignature,
216                @NotNull FunctionDescriptor functionDescriptor,
217                @Nullable Type thisType,
218                @NotNull Label methodBegin,
219                @NotNull Label methodEnd,
220                @NotNull Collection<String> localVariableNames,
221                @NotNull Map<Name, Label> labelsForSharedVars,
222                @NotNull OwnerKind ownerKind
223        ) {
224            Iterator<ValueParameterDescriptor> valueParameters = functionDescriptor.getValueParameters().iterator();
225            List<JvmMethodParameterSignature> params = jvmMethodSignature.getKotlinParameterTypes();
226            int shift = 0;
227    
228            boolean isStatic = AsmUtil.isStaticMethod(ownerKind, functionDescriptor);
229            if (!isStatic) {
230                //add this
231                if (thisType != null) {
232                    mv.visitLocalVariable("this", thisType.getDescriptor(), null, methodBegin, methodEnd, shift);
233                } else {
234                    //TODO: provide thisType for callable reference
235                }
236                shift++;
237            }
238    
239            for (int i = 0; i < params.size(); i++) {
240                JvmMethodParameterSignature param =  params.get(i);
241                JvmMethodParameterKind kind = param.getKind();
242                String parameterName = "$" + param.getKind().name().toLowerCase();
243    
244                if (needIndexForVar(kind)) {
245                    parameterName = parameterName + "$" + i;
246                }
247    
248                Type type = param.getAsmType();
249                if (kind == JvmMethodParameterKind.VALUE) {
250                    ValueParameterDescriptor parameter = valueParameters.next();
251                    Label divideLabel = labelsForSharedVars.get(parameter.getName());
252                    parameterName = parameter.getName().asString();
253                    if (divideLabel != null) {
254                        mv.visitLocalVariable(parameterName, type.getDescriptor(), null, methodBegin, divideLabel, shift);
255    
256                        String nameForSharedVar = createTmpVariableName(localVariableNames);
257                        localVariableNames.add(nameForSharedVar);
258    
259                        Type sharedVarType = typeMapper.getSharedVarType(parameter);
260                        mv.visitLocalVariable(nameForSharedVar, sharedVarType.getDescriptor(), null, divideLabel, methodEnd, shift);
261                        shift += Math.max(type.getSize(), sharedVarType.getSize());
262                        continue;
263                    }
264                }
265    
266                mv.visitLocalVariable(parameterName, type.getDescriptor(), null, methodBegin, methodEnd, shift);
267                shift += type.getSize();
268            }
269        }
270    
271        @NotNull
272        private Map<Name, Label> createSharedVarsForParameters(
273                @NotNull MethodVisitor mv,
274                @NotNull FunctionDescriptor functionDescriptor,
275                @NotNull FrameMap frameMap
276        ) {
277            Map<Name, Label> labelsForSharedVars = new HashMap<Name, Label>();
278    
279            for (ValueParameterDescriptor parameter : functionDescriptor.getValueParameters()) {
280                Type sharedVarType = typeMapper.getSharedVarType(parameter);
281                if (sharedVarType == null) {
282                    continue;
283                }
284    
285                Type localVarType = typeMapper.mapType(parameter);
286                int index = frameMap.getIndex(parameter);
287                mv.visitTypeInsn(NEW, sharedVarType.getInternalName());
288                mv.visitInsn(DUP);
289                mv.visitInsn(DUP);
290                mv.visitMethodInsn(INVOKESPECIAL, sharedVarType.getInternalName(), "<init>", "()V");
291                mv.visitVarInsn(localVarType.getOpcode(ILOAD), index);
292                mv.visitFieldInsn(PUTFIELD, sharedVarType.getInternalName(), "ref", StackValue.refType(localVarType).getDescriptor());
293    
294                Label labelForSharedVar = new Label();
295                mv.visitLabel(labelForSharedVar);
296    
297                labelsForSharedVars.put(parameter.getName(), labelForSharedVar);
298    
299                mv.visitVarInsn(sharedVarType.getOpcode(ISTORE), index);
300            }
301    
302            return labelsForSharedVars;
303        }
304    
305        private static void generateStaticDelegateMethodBody(
306                @NotNull MethodVisitor mv,
307                @NotNull Method asmMethod,
308                @NotNull OwnerKind.StaticDelegateKind dk
309        ) {
310            InstructionAdapter iv = new InstructionAdapter(mv);
311            Type[] argTypes = asmMethod.getArgumentTypes();
312    
313            // The first line of some namespace file is written to the line number attribute of a static delegate to allow to 'step into' it
314            // This is similar to what javac does with bridge methods
315            Label label = new Label();
316            iv.visitLabel(label);
317            iv.visitLineNumber(1, label);
318    
319            int k = 0;
320            for (Type argType : argTypes) {
321                iv.load(k, argType);
322                k += argType.getSize();
323            }
324            iv.invokestatic(dk.getOwnerClass(), asmMethod.getName(), asmMethod.getDescriptor());
325            iv.areturn(asmMethod.getReturnType());
326        }
327    
328        private void genJetAnnotations(
329                @NotNull MethodVisitor mv,
330                @NotNull FunctionDescriptor functionDescriptor,
331                @NotNull JvmMethodSignature jvmSignature
332        ) {
333    
334            if (functionDescriptor instanceof PropertyAccessorDescriptor) {
335                assert jvmSignature instanceof JvmPropertyAccessorSignature : "jvmSignature for property should have JvmPropertyAccessorSignature type";
336                PropertyCodegen.generateJetPropertyAnnotation(mv, (JvmPropertyAccessorSignature) jvmSignature,
337                        ((PropertyAccessorDescriptor) functionDescriptor).getCorrespondingProperty(), functionDescriptor.getVisibility());
338            }
339            else if (functionDescriptor instanceof SimpleFunctionDescriptor) {
340                assert !(jvmSignature instanceof JvmPropertyAccessorSignature) : "jvmSignature for function shouldn't have JvmPropertyAccessorSignature type";
341    
342                Modality modality = functionDescriptor.getModality();
343                JetMethodAnnotationWriter aw = JetMethodAnnotationWriter.visitAnnotation(mv);
344                int kotlinFlags = getFlagsForVisibility(functionDescriptor.getVisibility());
345                if (isInterface(functionDescriptor.getContainingDeclaration()) && modality != Modality.ABSTRACT) {
346                    kotlinFlags |= modality == Modality.FINAL
347                                    ? JvmStdlibNames.FLAG_FORCE_FINAL_BIT
348                                    : JvmStdlibNames.FLAG_FORCE_OPEN_BIT;
349                }
350                kotlinFlags |= DescriptorKindUtils.kindToFlags(functionDescriptor.getKind());
351                aw.writeFlags(kotlinFlags);
352                if (jvmSignature.getKotlinTypeParameter() != null) {
353                    aw.writeTypeParameters(jvmSignature.getKotlinTypeParameter());
354                }
355                aw.writeReturnType(jvmSignature.getKotlinReturnType());
356                aw.visitEnd();
357            }
358            else if (functionDescriptor instanceof ConstructorDescriptor) {
359                AnnotationVisitor jetConstructorVisitor = mv.visitAnnotation(JvmStdlibNames.JET_CONSTRUCTOR.getDescriptor(), true);
360    
361                int flagsValue = getFlagsForVisibility(functionDescriptor.getVisibility());
362                if (JvmStdlibNames.FLAGS_DEFAULT_VALUE != flagsValue) {
363                    jetConstructorVisitor.visit(JvmStdlibNames.JET_FLAGS_FIELD, flagsValue);
364                }
365    
366                jetConstructorVisitor.visitEnd();
367            }
368            else {
369                throw new IllegalStateException();
370            }
371    
372            Iterator<ValueParameterDescriptor> valueParameters = functionDescriptor.getValueParameters().iterator();
373            List<JvmMethodParameterSignature> kotlinParameterTypes = jvmSignature.getKotlinParameterTypes();
374    
375            assert kotlinParameterTypes != null;
376    
377            for (int i = 0; i < kotlinParameterTypes.size(); i++) {
378                JvmMethodParameterSignature param =  kotlinParameterTypes.get(i);
379                JvmMethodParameterKind kind = param.getKind();
380                String parameterName = "$" + param.getKind().name().toLowerCase();
381    
382                ValueParameterDescriptor parameterDescriptor = null;
383                if (kind == JvmMethodParameterKind.VALUE) {
384                    parameterDescriptor = valueParameters.next();
385                    parameterName = parameterDescriptor.getName().asString();
386                } else if (kind == JvmMethodParameterKind.ENUM_NAME || kind == JvmMethodParameterKind.ENUM_ORDINAL) {
387                    //we shouldn't generate annotations for invisible in runtime parameters otherwise we get bad RuntimeInvisibleParameterAnnotations error in javac
388                    continue;
389                } else if (needIndexForVar(kind)) {
390                    parameterName = parameterName + "$" + i;
391                }
392    
393                AnnotationCodegen.forParameter(i, mv, typeMapper).genAnnotations(parameterDescriptor);
394                JetValueParameterAnnotationWriter av = JetValueParameterAnnotationWriter.visitParameterAnnotation(mv, i);
395                av.writeName(parameterName);
396                if (kind == JvmMethodParameterKind.RECEIVER) {
397                    av.writeReceiver();
398                }
399                if (parameterDescriptor != null) {
400                    av.writeHasDefaultValue(parameterDescriptor.declaresDefaultValue());
401                    av.writeVararg(parameterDescriptor.getVarargElementType() != null);
402                }
403                av.writeType(param.getKotlinSignature());
404                av.visitEnd();
405            }
406        }
407    
408        private boolean needIndexForVar(JvmMethodParameterKind kind) {
409            return kind == JvmMethodParameterKind.SHARED_VAR || kind == JvmMethodParameterKind.SUPER_CALL_PARAM;
410        }
411    
412        public static void endVisit(MethodVisitor mv, @Nullable String description, @Nullable PsiElement method) {
413            try {
414                mv.visitMaxs(-1, -1);
415            }
416            catch (ProcessCanceledException e) {
417                throw e;
418            }
419            catch (Throwable t) {
420                throw new CompilationException(
421                        "wrong code generated" +
422                        (description != null ? " for " + description : "") +
423                        t.getClass().getName() +
424                        " " +
425                        t.getMessage(),
426                        t, method);
427            }
428            mv.visitEnd();
429        }
430    
431        static void generateBridgeIfNeeded(
432                CodegenContext owner,
433                GenerationState state,
434                ClassBuilder v,
435                Method jvmSignature,
436                FunctionDescriptor functionDescriptor
437        ) {
438            if (owner.getContextKind() == OwnerKind.TRAIT_IMPL) {
439                return;
440            }
441    
442            Method method =
443                    state.getTypeMapper().mapSignature(functionDescriptor).getAsmMethod();
444    
445            Queue<FunctionDescriptor> bfsQueue = new LinkedList<FunctionDescriptor>();
446            Set<FunctionDescriptor> visited = new HashSet<FunctionDescriptor>();
447    
448            bfsQueue.offer(functionDescriptor.getOriginal());
449            visited.add(functionDescriptor.getOriginal());
450            for (FunctionDescriptor overriddenDescriptor : functionDescriptor.getOverriddenDescriptors()) {
451                FunctionDescriptor orig = overriddenDescriptor.getOriginal();
452                if (!visited.contains(orig)) {
453                    bfsQueue.offer(overriddenDescriptor);
454                    visited.add(overriddenDescriptor);
455                }
456            }
457    
458            Set<Method> bridgesToGenerate = new HashSet<Method>();
459            while (!bfsQueue.isEmpty()) {
460                FunctionDescriptor descriptor = bfsQueue.poll();
461                if (descriptor.getKind() == CallableMemberDescriptor.Kind.DECLARATION) {
462                    Method overridden =
463                            state.getTypeMapper().mapSignature(descriptor.getOriginal()).getAsmMethod();
464                    if (differentMethods(method, overridden)) {
465                        bridgesToGenerate.add(overridden);
466                    }
467                    continue;
468                }
469    
470                for (FunctionDescriptor overriddenDescriptor : descriptor.getOverriddenDescriptors()) {
471                    FunctionDescriptor orig = overriddenDescriptor.getOriginal();
472                    if (!visited.contains(orig)) {
473                        bfsQueue.offer(orig);
474                        visited.add(orig);
475                    }
476                }
477            }
478    
479            for (Method overridden : bridgesToGenerate) {
480                generateBridge(owner, state, v, jvmSignature, functionDescriptor, overridden);
481            }
482        }
483    
484        static void generateConstructorWithoutParametersIfNeeded(
485                @NotNull GenerationState state,
486                @NotNull CallableMethod method,
487                @NotNull ConstructorDescriptor constructorDescriptor,
488                @NotNull ClassBuilder classBuilder
489        ) {
490            if (!isDefaultConstructorNeeded(state.getBindingContext(), constructorDescriptor)) {
491                return;
492            }
493            int flags = getVisibilityAccessFlag(constructorDescriptor);
494            MethodVisitor mv = classBuilder.newMethod(null, flags, "<init>", "()V", null, null);
495    
496            if (state.getClassBuilderMode() == ClassBuilderMode.SIGNATURES) {
497                return;
498            }
499            else if (state.getClassBuilderMode() == ClassBuilderMode.STUBS) {
500                genStubCode(mv);
501            }
502            else if (state.getClassBuilderMode() == ClassBuilderMode.FULL) {
503                InstructionAdapter v = new InstructionAdapter(mv);
504                mv.visitCode();
505    
506                JvmClassName ownerInternalName = method.getOwner();
507                Method jvmSignature = method.getSignature().getAsmMethod();
508                v.load(0, ownerInternalName.getAsmType()); // Load this on stack
509    
510                int mask = 0;
511                for (ValueParameterDescriptor parameterDescriptor : constructorDescriptor.getValueParameters()) {
512                    Type paramType = state.getTypeMapper().mapType(parameterDescriptor.getType());
513                    pushDefaultValueOnStack(paramType, v);
514                    mask |= (1 << parameterDescriptor.getIndex());
515                }
516                v.iconst(mask);
517                String desc = jvmSignature.getDescriptor().replace(")", "I)");
518                v.invokespecial(ownerInternalName.getInternalName(), "<init>", desc);
519                v.areturn(Type.VOID_TYPE);
520                endVisit(mv, "default constructor for " + ownerInternalName.getInternalName(), null);
521            }
522        }
523    
524        static void generateDefaultIfNeeded(
525                @NotNull MethodContext owner,
526                @NotNull GenerationState state,
527                @NotNull ClassBuilder v,
528                @NotNull JvmMethodSignature signature,
529                @NotNull FunctionDescriptor functionDescriptor,
530                @NotNull OwnerKind kind,
531                @NotNull DefaultParameterValueLoader loadStrategy
532        ) {
533            DeclarationDescriptor contextClass = owner.getContextDescriptor().getContainingDeclaration();
534    
535            if (kind != OwnerKind.TRAIT_IMPL &&
536                contextClass instanceof ClassDescriptor &&
537                ((ClassDescriptor) contextClass).getKind() == ClassKind.TRAIT) {
538                return;
539            }
540    
541            if (!isDefaultNeeded(functionDescriptor)) {
542                return;
543            }
544    
545            boolean isStatic = isStatic(kind);
546    
547            Method jvmSignature = signature.getAsmMethod();
548    
549            int flags = ACC_PUBLIC | ACC_SYNTHETIC; // TODO.
550    
551            JvmClassName ownerInternalName;
552            if (contextClass instanceof NamespaceDescriptor) {
553                ownerInternalName = state.getTypeMapper().getOwner(functionDescriptor, kind, true);
554            }
555            else {
556                ownerInternalName = JvmClassName.byType(state.getTypeMapper()
557                                                                .mapType(((ClassDescriptor) contextClass).getDefaultType(),
558                                                                         JetTypeMapperMode.IMPL));
559            }
560    
561            String descriptor = jvmSignature.getDescriptor().replace(")", "I)");
562            boolean isConstructor = "<init>".equals(jvmSignature.getName());
563            if (!isStatic && !isConstructor) {
564                descriptor = descriptor.replace("(", "(" + ownerInternalName.getDescriptor());
565            }
566            MethodVisitor mv = v.newMethod(null, flags | (isConstructor ? 0 : ACC_STATIC),
567                                                 isConstructor ? "<init>" : jvmSignature.getName() + JvmAbi.DEFAULT_PARAMS_IMPL_SUFFIX,
568                                                 descriptor, null, null);
569    
570            if (state.getClassBuilderMode() == ClassBuilderMode.STUBS) {
571                genStubCode(mv);
572            }
573            else if (state.getClassBuilderMode() == ClassBuilderMode.FULL) {
574                generateDefaultImpl(owner, state, signature, functionDescriptor, kind, isStatic, mv, loadStrategy);
575            }
576        }
577    
578        private static void generateDefaultImpl(
579                @NotNull MethodContext methodContext,
580                @NotNull GenerationState state,
581                @NotNull JvmMethodSignature signature,
582                @NotNull FunctionDescriptor functionDescriptor,
583                @NotNull OwnerKind kind,
584                boolean aStatic,
585                @NotNull MethodVisitor mv,
586                @NotNull DefaultParameterValueLoader loadStrategy
587        ) {
588            mv.visitCode();
589    
590            FrameMap frameMap = new FrameMap();
591    
592            if (!aStatic) {
593                frameMap.enterTemp(OBJECT_TYPE);
594            }
595    
596            Method jvmSignature = signature.getAsmMethod();
597            ExpressionCodegen codegen = new ExpressionCodegen(mv, frameMap, jvmSignature.getReturnType(), methodContext, state);
598    
599            Type[] argTypes = jvmSignature.getArgumentTypes();
600            List<ValueParameterDescriptor> paramDescrs = functionDescriptor.getValueParameters();
601            Iterator<ValueParameterDescriptor> iterator = paramDescrs.iterator();
602    
603            int countOfExtraVarsInMethodArgs = 0;
604            List<JvmMethodParameterSignature> params = signature.getKotlinParameterTypes();
605    
606            for (int i = 0; i < params.size(); i++) {
607                JvmMethodParameterSignature parameterSignature = params.get(i);
608                if (parameterSignature.getKind() != JvmMethodParameterKind.VALUE) {
609                    countOfExtraVarsInMethodArgs++;
610                    frameMap.enterTemp(parameterSignature.getAsmType());
611                } else {
612                    frameMap.enter(iterator.next(), parameterSignature.getAsmType());
613                }
614            }
615    
616            int maskIndex = frameMap.enterTemp(Type.INT_TYPE);
617    
618            InstructionAdapter iv = new InstructionAdapter(mv);
619            loadExplicitArgumentsOnStack(iv, OBJECT_TYPE, aStatic, signature);
620    
621            for (int index = 0; index < paramDescrs.size(); index++) {
622                ValueParameterDescriptor parameterDescriptor = paramDescrs.get(index);
623    
624                Type t = argTypes[countOfExtraVarsInMethodArgs + index];
625    
626                if (parameterDescriptor.declaresDefaultValue()) {
627                    iv.load(maskIndex, Type.INT_TYPE);
628                    iv.iconst(1 << index);
629                    iv.and(Type.INT_TYPE);
630                    Label loadArg = new Label();
631                    iv.ifeq(loadArg);
632    
633                    loadStrategy.putValueOnStack(parameterDescriptor, codegen);
634    
635                    int ind = frameMap.getIndex(parameterDescriptor);
636                    iv.store(ind, t);
637    
638                    iv.mark(loadArg);
639                }
640    
641                iv.load(frameMap.getIndex(parameterDescriptor), t);
642            }
643    
644            CallableMethod method = null;
645            if (functionDescriptor instanceof ConstructorDescriptor) {
646                method = state.getTypeMapper().mapToCallableMethod((ConstructorDescriptor) functionDescriptor);
647            } else {
648                method = state.getTypeMapper()
649                        .mapToCallableMethod(functionDescriptor, false, isCallInsideSameClassAsDeclared(functionDescriptor, methodContext),
650                                             isCallInsideSameModuleAsDeclared(functionDescriptor, methodContext), OwnerKind.IMPLEMENTATION);
651            }
652    
653            iv.visitMethodInsn(method.getInvokeOpcode(), method.getOwner().getInternalName(), method.getSignature().getAsmMethod().getName(),
654                               method.getSignature().getAsmMethod().getDescriptor());
655    
656            iv.areturn(jvmSignature.getReturnType());
657    
658            endVisit(mv, "default method", callableDescriptorToDeclaration(state.getBindingContext(), functionDescriptor));
659            mv.visitEnd();
660        }
661    
662    
663        private static void loadExplicitArgumentsOnStack(
664                @NotNull InstructionAdapter iv,
665                @NotNull Type ownerType,
666                boolean isStatic,
667                @NotNull JvmMethodSignature signature
668        ) {
669            int var = 0;
670            if (!isStatic) {
671                iv.load(var, ownerType);
672                var += ownerType.getSize();
673            }
674    
675            List<JvmMethodParameterSignature> params = signature.getKotlinParameterTypes();
676            for (int i = 0; i < params.size(); i++) {
677                JvmMethodParameterSignature parameterSignature = params.get(i);
678                if (parameterSignature.getKind() != JvmMethodParameterKind.VALUE) {
679                    Type type = parameterSignature.getAsmType();
680                    iv.load(var, type);
681                    var += type.getSize();
682                }
683            }
684        }
685    
686        private static boolean isDefaultNeeded(FunctionDescriptor functionDescriptor) {
687            boolean needed = false;
688            if (functionDescriptor != null) {
689                for (ValueParameterDescriptor parameterDescriptor : functionDescriptor.getValueParameters()) {
690                    if (parameterDescriptor.declaresDefaultValue()) {
691                        needed = true;
692                        break;
693                    }
694                }
695            }
696            return needed;
697        }
698    
699        private static boolean isDefaultConstructorNeeded(@NotNull BindingContext context, @NotNull ConstructorDescriptor constructorDescriptor) {
700            ClassDescriptor classDescriptor = constructorDescriptor.getContainingDeclaration();
701    
702            if (CodegenBinding.canHaveOuter(context, classDescriptor)) return false;
703    
704            if (classDescriptor.getVisibility() == Visibilities.PRIVATE ||
705                constructorDescriptor.getVisibility() == Visibilities.PRIVATE) return false;
706    
707            if (constructorDescriptor.getValueParameters().isEmpty()) return false;
708    
709            for (ValueParameterDescriptor parameterDescriptor : constructorDescriptor.getValueParameters()) {
710                if (!parameterDescriptor.declaresDefaultValue()) {
711                    return false;
712                }
713            }
714            return true;
715        }
716    
717        private static boolean differentMethods(Method method, Method overridden) {
718            if (!method.getReturnType().equals(overridden.getReturnType())) {
719                return true;
720            }
721            Type[] methodArgumentTypes = method.getArgumentTypes();
722            Type[] overriddenArgumentTypes = overridden.getArgumentTypes();
723            if (methodArgumentTypes.length != overriddenArgumentTypes.length) {
724                return true;
725            }
726            for (int i = 0; i != methodArgumentTypes.length; ++i) {
727                if (!methodArgumentTypes[i].equals(overriddenArgumentTypes[i])) {
728                    return true;
729                }
730            }
731            return false;
732        }
733    
734        private static void generateBridge(
735                CodegenContext owner,
736                GenerationState state,
737                ClassBuilder v,
738                Method jvmSignature,
739                FunctionDescriptor functionDescriptor,
740                Method overridden
741        ) {
742            int flags = ACC_PUBLIC | ACC_BRIDGE | ACC_SYNTHETIC; // TODO.
743    
744            MethodVisitor mv = v.newMethod(null, flags, jvmSignature.getName(), overridden.getDescriptor(), null, null);
745            if (state.getClassBuilderMode() == ClassBuilderMode.STUBS) {
746                genStubCode(mv);
747            }
748            else if (state.getClassBuilderMode() == ClassBuilderMode.FULL) {
749                mv.visitCode();
750    
751                Type[] argTypes = overridden.getArgumentTypes();
752                Type[] originalArgTypes = jvmSignature.getArgumentTypes();
753    
754                InstructionAdapter iv = new InstructionAdapter(mv);
755                iv.load(0, OBJECT_TYPE);
756                for (int i = 0, reg = 1; i < argTypes.length; i++) {
757                    StackValue.local(reg, argTypes[i]).put(originalArgTypes[i], iv);
758                    //noinspection AssignmentToForLoopParameter
759                    reg += argTypes[i].getSize();
760                }
761    
762                iv.invokevirtual(v.getThisName(), jvmSignature.getName(), jvmSignature.getDescriptor());
763    
764                StackValue.onStack(jvmSignature.getReturnType()).put(overridden.getReturnType(), iv);
765    
766                iv.areturn(overridden.getReturnType());
767                endVisit(mv, "bridge method", callableDescriptorToDeclaration(state.getBindingContext(), functionDescriptor));
768            }
769        }
770    
771        public void genDelegate(FunctionDescriptor functionDescriptor, FunctionDescriptor overriddenDescriptor, StackValue field) {
772            genDelegate(functionDescriptor, (ClassDescriptor) overriddenDescriptor.getContainingDeclaration(), field,
773                        typeMapper.mapSignature(functionDescriptor),
774                        typeMapper.mapSignature(overriddenDescriptor.getOriginal())
775            );
776        }
777    
778        public void genDelegate(
779                FunctionDescriptor functionDescriptor,
780                ClassDescriptor toClass,
781                StackValue field,
782                JvmMethodSignature jvmDelegateMethodSignature,
783                JvmMethodSignature jvmOverriddenMethodSignature
784        ) {
785            Method overriddenMethod = jvmOverriddenMethodSignature.getAsmMethod();
786            Method delegateMethod = jvmDelegateMethodSignature.getAsmMethod();
787    
788            int flags = ACC_PUBLIC | ACC_SYNTHETIC; // TODO.
789    
790            MethodVisitor mv = v.newMethod(null, flags, delegateMethod.getName(), delegateMethod.getDescriptor(), null, null);
791            if (state.getClassBuilderMode() == ClassBuilderMode.STUBS) {
792                genStubCode(mv);
793            }
794            else if (state.getClassBuilderMode() == ClassBuilderMode.FULL) {
795                mv.visitCode();
796    
797                Type[] argTypes = delegateMethod.getArgumentTypes();
798                Type[] originalArgTypes = overriddenMethod.getArgumentTypes();
799    
800                InstructionAdapter iv = new InstructionAdapter(mv);
801                iv.load(0, OBJECT_TYPE);
802                field.put(field.type, iv);
803                for (int i = 0, reg = 1; i < argTypes.length; i++) {
804                    StackValue.local(reg, argTypes[i]).put(originalArgTypes[i], iv);
805                    //noinspection AssignmentToForLoopParameter
806                    reg += argTypes[i].getSize();
807                }
808    
809                String internalName = typeMapper.mapType(toClass).getInternalName();
810                if (toClass.getKind() == ClassKind.TRAIT) {
811                    iv.invokeinterface(internalName, overriddenMethod.getName(), overriddenMethod.getDescriptor());
812                }
813                else {
814                    iv.invokevirtual(internalName, overriddenMethod.getName(), overriddenMethod.getDescriptor());
815                }
816    
817                StackValue.onStack(overriddenMethod.getReturnType()).put(delegateMethod.getReturnType(), iv);
818    
819                iv.areturn(delegateMethod.getReturnType());
820                endVisit(mv, "Delegate method " + functionDescriptor + " to " + jvmOverriddenMethodSignature,
821                         descriptorToDeclaration(bindingContext, functionDescriptor.getContainingDeclaration()));
822    
823                generateBridgeIfNeeded(owner, state, v, jvmDelegateMethodSignature.getAsmMethod(), functionDescriptor);
824            }
825        }
826    }