001    /*
002     * Copyright 2010-2015 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.kotlin.codegen;
018    
019    import org.jetbrains.annotations.NotNull;
020    import org.jetbrains.kotlin.codegen.context.CodegenContext;
021    import org.jetbrains.kotlin.codegen.state.GenerationState;
022    import org.jetbrains.kotlin.codegen.state.JetTypeMapper;
023    import org.jetbrains.kotlin.descriptors.*;
024    import org.jetbrains.kotlin.descriptors.impl.ClassDescriptorImpl;
025    import org.jetbrains.kotlin.descriptors.impl.SimpleFunctionDescriptorImpl;
026    import org.jetbrains.kotlin.load.java.descriptors.JavaClassDescriptor;
027    import org.jetbrains.kotlin.load.kotlin.PackageClassUtils;
028    import org.jetbrains.kotlin.load.kotlin.PackagePartClassUtils;
029    import org.jetbrains.kotlin.name.FqName;
030    import org.jetbrains.kotlin.name.Name;
031    import org.jetbrains.kotlin.psi.JetFile;
032    import org.jetbrains.kotlin.resolve.DescriptorUtils;
033    import org.jetbrains.kotlin.types.JetType;
034    import org.jetbrains.kotlin.types.expressions.OperatorConventions;
035    import org.jetbrains.org.objectweb.asm.MethodVisitor;
036    import org.jetbrains.org.objectweb.asm.Type;
037    import org.jetbrains.org.objectweb.asm.commons.InstructionAdapter;
038    
039    import java.util.Collections;
040    
041    import static org.jetbrains.kotlin.codegen.AsmUtil.*;
042    import static org.jetbrains.kotlin.load.java.JvmAnnotationNames.KotlinSyntheticClass;
043    import static org.jetbrains.kotlin.resolve.jvm.AsmTypes.OBJECT_TYPE;
044    import static org.jetbrains.kotlin.resolve.jvm.diagnostics.DiagnosticsPackage.OtherOrigin;
045    import static org.jetbrains.org.objectweb.asm.Opcodes.*;
046    
047    public class SamWrapperCodegen {
048        private static final String FUNCTION_FIELD_NAME = "function";
049    
050        private final GenerationState state;
051        private final JetTypeMapper typeMapper;
052        private final SamType samType;
053        private final MemberCodegen<?> parentCodegen;
054    
055        public SamWrapperCodegen(@NotNull GenerationState state, @NotNull SamType samType, @NotNull MemberCodegen<?> parentCodegen) {
056            this.state = state;
057            this.typeMapper = state.getTypeMapper();
058            this.samType = samType;
059            this.parentCodegen = parentCodegen;
060        }
061    
062        public Type genWrapper(@NotNull JetFile file) {
063            // Name for generated class, in form of whatever$1
064            FqName fqName = getWrapperName(file);
065            Type asmType = asmTypeByFqNameWithoutInnerClasses(fqName);
066    
067            // e.g. (T, T) -> Int
068            JetType functionType = samType.getKotlinFunctionType();
069    
070            ClassDescriptor classDescriptor = new ClassDescriptorImpl(
071                    samType.getJavaClassDescriptor().getContainingDeclaration(),
072                    fqName.shortName(),
073                    Modality.FINAL,
074                    Collections.singleton(samType.getType()),
075                    SourceElement.NO_SOURCE
076            );
077            // e.g. compare(T, T)
078            SimpleFunctionDescriptor erasedInterfaceFunction = samType.getAbstractMethod().getOriginal().copy(
079                    classDescriptor,
080                    Modality.FINAL,
081                    Visibilities.PUBLIC,
082                    CallableMemberDescriptor.Kind.SYNTHESIZED,
083                    /*copyOverrides=*/ false
084            );
085    
086            ClassBuilder cv = state.getFactory().newVisitor(OtherOrigin(erasedInterfaceFunction), asmType, file);
087            cv.defineClass(file,
088                           V1_6,
089                           ACC_FINAL,
090                           asmType.getInternalName(),
091                           null,
092                           OBJECT_TYPE.getInternalName(),
093                           new String[]{ typeMapper.mapType(samType.getType()).getInternalName() }
094            );
095            cv.visitSource(file.getName(), null);
096    
097            writeKotlinSyntheticClassAnnotation(cv, KotlinSyntheticClass.Kind.SAM_WRAPPER);
098    
099            // e.g. ASM type for Function2
100            Type functionAsmType = typeMapper.mapType(functionType);
101    
102            cv.newField(OtherOrigin(erasedInterfaceFunction),
103                        ACC_SYNTHETIC | ACC_PRIVATE | ACC_FINAL,
104                        FUNCTION_FIELD_NAME,
105                        functionAsmType.getDescriptor(),
106                        null,
107                        null);
108    
109            generateConstructor(asmType, functionAsmType, cv);
110            generateMethod(asmType, functionAsmType, cv, erasedInterfaceFunction, functionType);
111    
112            cv.done();
113    
114            return asmType;
115        }
116    
117        private void generateConstructor(Type ownerType, Type functionType, ClassBuilder cv) {
118            MethodVisitor mv = cv.newMethod(OtherOrigin(samType.getJavaClassDescriptor()),
119                                            NO_FLAG_PACKAGE_PRIVATE, "<init>", Type.getMethodDescriptor(Type.VOID_TYPE, functionType), null, null);
120    
121            if (state.getClassBuilderMode() == ClassBuilderMode.FULL) {
122                mv.visitCode();
123                InstructionAdapter iv = new InstructionAdapter(mv);
124    
125                // super constructor
126                iv.load(0, OBJECT_TYPE);
127                iv.invokespecial(OBJECT_TYPE.getInternalName(), "<init>", "()V", false);
128    
129                // save parameter to field
130                iv.load(0, OBJECT_TYPE);
131                iv.load(1, functionType);
132                iv.putfield(ownerType.getInternalName(), FUNCTION_FIELD_NAME, functionType.getDescriptor());
133    
134                iv.visitInsn(RETURN);
135                FunctionCodegen.endVisit(iv, "constructor of SAM wrapper", null);
136            }
137        }
138    
139        private void generateMethod(
140                Type ownerType,
141                Type functionType,
142                ClassBuilder cv,
143                SimpleFunctionDescriptor erasedInterfaceFunction,
144                JetType functionJetType
145        ) {
146            // using static context to avoid creating ClassDescriptor and everything else
147            FunctionCodegen codegen = new FunctionCodegen(CodegenContext.STATIC.intoClass(
148                    (ClassDescriptor) erasedInterfaceFunction.getContainingDeclaration(), OwnerKind.IMPLEMENTATION, state), cv, state, parentCodegen);
149    
150            FunctionDescriptor invokeFunction =
151                    functionJetType.getMemberScope().getFunctions(OperatorConventions.INVOKE).iterator().next().getOriginal();
152            StackValue functionField = StackValue.field(functionType, ownerType, FUNCTION_FIELD_NAME, false, StackValue.none());
153            codegen.genDelegate(erasedInterfaceFunction, invokeFunction, functionField);
154    
155            // generate sam bridges
156            // TODO: erasedInterfaceFunction is actually not an interface function, but function in generated class
157            SimpleFunctionDescriptor originalInterfaceErased = samType.getAbstractMethod().getOriginal();
158            SimpleFunctionDescriptorImpl descriptorForBridges = SimpleFunctionDescriptorImpl
159                    .create(erasedInterfaceFunction.getContainingDeclaration(), erasedInterfaceFunction.getAnnotations(), originalInterfaceErased.getName(),
160                            CallableMemberDescriptor.Kind.DECLARATION, erasedInterfaceFunction.getSource());
161    
162            descriptorForBridges
163                    .initialize(null, originalInterfaceErased.getDispatchReceiverParameter(), originalInterfaceErased.getTypeParameters(),
164                                originalInterfaceErased.getValueParameters(), originalInterfaceErased.getReturnType(), Modality.OPEN,
165                                originalInterfaceErased.getVisibility());
166    
167            descriptorForBridges.addOverriddenDescriptor(originalInterfaceErased);
168            codegen.generateBridges(descriptorForBridges);
169        }
170    
171        @NotNull
172        private FqName getWrapperName(@NotNull JetFile containingFile) {
173            FqName packageClassFqName = PackageClassUtils.getPackageClassFqName(containingFile.getPackageFqName());
174            JavaClassDescriptor descriptor = samType.getJavaClassDescriptor();
175            int hash = PackagePartClassUtils.getPathHashCode(containingFile.getVirtualFile()) * 31 +
176                    DescriptorUtils.getFqNameSafe(descriptor).hashCode();
177            String shortName = String.format(
178                    "%s$sam$%s$%08x",
179                    packageClassFqName.shortName().asString(),
180                    descriptor.getName().asString(),
181                    hash
182            );
183            return packageClassFqName.parent().child(Name.identifier(shortName));
184        }
185    }