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
017package org.jetbrains.jet.codegen;
018
019import org.jetbrains.annotations.NotNull;
020import org.jetbrains.asm4.MethodVisitor;
021import org.jetbrains.asm4.Type;
022import org.jetbrains.asm4.commons.InstructionAdapter;
023import org.jetbrains.jet.codegen.context.CodegenContext;
024import org.jetbrains.jet.codegen.state.GenerationState;
025import org.jetbrains.jet.codegen.state.GenerationStateAware;
026import org.jetbrains.jet.codegen.state.JetTypeMapperMode;
027import org.jetbrains.jet.lang.descriptors.FunctionDescriptor;
028import org.jetbrains.jet.lang.descriptors.NamespaceDescriptor;
029import org.jetbrains.jet.lang.descriptors.SimpleFunctionDescriptor;
030import org.jetbrains.jet.lang.psi.JetFile;
031import org.jetbrains.jet.lang.resolve.BindingContext;
032import org.jetbrains.jet.lang.resolve.DescriptorUtils;
033import org.jetbrains.jet.lang.resolve.java.JvmClassName;
034import org.jetbrains.jet.lang.resolve.java.PackageClassUtils;
035import org.jetbrains.jet.lang.resolve.java.descriptor.ClassDescriptorFromJvmBytecode;
036import org.jetbrains.jet.lang.resolve.java.sam.SingleAbstractMethodUtils;
037import org.jetbrains.jet.lang.resolve.name.FqName;
038import org.jetbrains.jet.lang.resolve.name.Name;
039import org.jetbrains.jet.lang.types.JetType;
040
041import static org.jetbrains.asm4.Opcodes.*;
042import static org.jetbrains.jet.codegen.AsmUtil.NO_FLAG_PACKAGE_PRIVATE;
043import static org.jetbrains.jet.codegen.AsmUtil.genStubCode;
044import static org.jetbrains.jet.lang.resolve.java.AsmTypeConstants.OBJECT_TYPE;
045
046public class SamWrapperCodegen extends GenerationStateAware {
047    private static final String FUNCTION_FIELD_NAME = "function";
048
049    @NotNull private final ClassDescriptorFromJvmBytecode samInterface;
050
051    public SamWrapperCodegen(@NotNull GenerationState state, @NotNull ClassDescriptorFromJvmBytecode samInterface) {
052        super(state);
053        this.samInterface = samInterface;
054    }
055
056    public JvmClassName genWrapper(@NotNull JetFile file) {
057        // Name for generated class, in form of whatever$1
058        JvmClassName name = JvmClassName.byInternalName(getWrapperName(file));
059
060        // e.g. (T, T) -> Int
061        JetType functionType = samInterface.getFunctionTypeForSamInterface();
062        assert functionType != null : samInterface.toString();
063        // e.g. compare(T, T)
064        SimpleFunctionDescriptor interfaceFunction = SingleAbstractMethodUtils.getAbstractMethodOfSamInterface(samInterface);
065
066        ClassBuilder cv = state.getFactory().newVisitor(name.getInternalName(), file);
067        cv.defineClass(file,
068                       V1_6,
069                       ACC_FINAL,
070                       name.getInternalName(),
071                       null,
072                       OBJECT_TYPE.getInternalName(),
073                       new String[]{JvmClassName.byClassDescriptor(samInterface).getInternalName()}
074        );
075        cv.visitSource(file.getName(), null);
076
077        // e.g. ASM type for Function2
078        Type functionAsmType = state.getTypeMapper().mapType(functionType, JetTypeMapperMode.VALUE);
079
080        cv.newField(null,
081                    ACC_SYNTHETIC | ACC_PRIVATE | ACC_FINAL,
082                    FUNCTION_FIELD_NAME,
083                    functionAsmType.getDescriptor(),
084                    null,
085                    null);
086
087        generateConstructor(name.getAsmType(), functionAsmType, cv);
088        generateMethod(name.getAsmType(), functionAsmType, cv, interfaceFunction, functionType);
089
090        cv.done();
091
092        return name;
093    }
094
095    private void generateConstructor(Type ownerType, Type functionType, ClassBuilder cv) {
096        MethodVisitor mv = cv.newMethod(null, NO_FLAG_PACKAGE_PRIVATE, "<init>", Type.getMethodDescriptor(Type.VOID_TYPE, functionType), null, null);
097
098        if (state.getClassBuilderMode() == ClassBuilderMode.STUBS) {
099            genStubCode(mv);
100        }
101        else if (state.getClassBuilderMode() == ClassBuilderMode.FULL) {
102            mv.visitCode();
103            InstructionAdapter iv = new InstructionAdapter(mv);
104
105            // super constructor
106            iv.load(0, OBJECT_TYPE);
107            iv.invokespecial(OBJECT_TYPE.getInternalName(), "<init>", "()V");
108
109            // save parameter to field
110            iv.load(0, OBJECT_TYPE);
111            iv.load(1, functionType);
112            iv.putfield(ownerType.getInternalName(), FUNCTION_FIELD_NAME, functionType.getDescriptor());
113
114            iv.visitInsn(RETURN);
115            FunctionCodegen.endVisit(iv, "constructor of SAM wrapper", null);
116        }
117    }
118
119    private void generateMethod(
120            Type ownerType,
121            Type functionType,
122            ClassBuilder cv,
123            SimpleFunctionDescriptor interfaceFunction,
124            JetType functionJetType
125    ) {
126
127        // using static context to avoid creating ClassDescriptor and everything else
128        FunctionCodegen codegen = new FunctionCodegen(CodegenContext.STATIC, cv, state);
129
130        FunctionDescriptor invokeFunction = functionJetType.getMemberScope()
131                .getFunctions(Name.identifier("invoke")).iterator().next().getOriginal();
132        StackValue functionField = StackValue.field(functionType, JvmClassName.byType(ownerType), FUNCTION_FIELD_NAME, false);
133        codegen.genDelegate(interfaceFunction, invokeFunction, functionField);
134    }
135
136    private String getWrapperName(@NotNull JetFile containingFile) {
137        NamespaceDescriptor namespace = state.getBindingContext().get(BindingContext.FILE_TO_NAMESPACE, containingFile);
138        assert namespace != null : "couldn't find namespace for file: " + containingFile.getVirtualFile();
139        FqName fqName = DescriptorUtils.getFQName(namespace).toSafe();
140        String packageInternalName = JvmClassName.byFqNameWithoutInnerClasses(
141                PackageClassUtils.getPackageClassFqName(fqName)).getInternalName();
142        return packageInternalName + "$sam$" + samInterface.getName().asString() + "$" +
143               Integer.toHexString(CodegenUtil.getPathHashCode(containingFile) * 31 + DescriptorUtils.getFQName(samInterface).hashCode());
144    }
145}