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 org.jetbrains.annotations.NotNull;
020    import org.jetbrains.jet.codegen.context.MethodContext;
021    import org.jetbrains.jet.codegen.state.GenerationState;
022    import org.jetbrains.jet.codegen.state.JetTypeMapper;
023    import org.jetbrains.jet.lang.descriptors.CallableDescriptor;
024    import org.jetbrains.jet.lang.psi.JetDeclarationWithBody;
025    import org.jetbrains.jet.lang.resolve.java.jvmSignature.JvmMethodSignature;
026    import org.jetbrains.org.objectweb.asm.MethodVisitor;
027    
028    public abstract class FunctionGenerationStrategy {
029    
030        private FrameMap frameMap;
031    
032        public abstract void generateBody(
033                @NotNull MethodVisitor mv,
034                @NotNull JvmMethodSignature signature,
035                @NotNull MethodContext context,
036                @NotNull MemberCodegen<?> parentCodegen
037        );
038    
039        @NotNull
040        protected FrameMap createFrameMap(@NotNull JetTypeMapper typeMapper, @NotNull MethodContext context) {
041            return context.prepareFrame(typeMapper);
042        }
043    
044        @NotNull
045        public FrameMap getFrameMap(@NotNull JetTypeMapper typeMapper, @NotNull MethodContext context) {
046            if (frameMap == null) {
047                frameMap = createFrameMap(typeMapper, context);
048            }
049            return frameMap;
050        }
051    
052        public static class FunctionDefault extends CodegenBased<CallableDescriptor> {
053            private final JetDeclarationWithBody declaration;
054    
055            public FunctionDefault(
056                    @NotNull GenerationState state,
057                    @NotNull CallableDescriptor descriptor,
058                    @NotNull JetDeclarationWithBody declaration
059            ) {
060                super(state, descriptor);
061                this.declaration = declaration;
062            }
063    
064            @Override
065            public void doGenerateBody(@NotNull ExpressionCodegen codegen, @NotNull JvmMethodSignature signature) {
066                codegen.returnExpression(declaration.getBodyExpression());
067            }
068        }
069    
070        public abstract static class CodegenBased<T extends CallableDescriptor> extends FunctionGenerationStrategy {
071            protected final GenerationState state;
072            protected final T callableDescriptor;
073    
074            public CodegenBased(@NotNull GenerationState state, @NotNull T callableDescriptor) {
075                this.state = state;
076                this.callableDescriptor = callableDescriptor;
077            }
078    
079            @Override
080            public final void generateBody(
081                    @NotNull MethodVisitor mv,
082                    @NotNull JvmMethodSignature signature,
083                    @NotNull MethodContext context,
084                    @NotNull MemberCodegen<?> parentCodegen
085            ) {
086                ExpressionCodegen codegen = new ExpressionCodegen(mv, getFrameMap(state.getTypeMapper(), context),
087                                                                  signature.getReturnType(), context, state, parentCodegen);
088                doGenerateBody(codegen, signature);
089            }
090    
091            public abstract void doGenerateBody(@NotNull ExpressionCodegen codegen, @NotNull JvmMethodSignature signature);
092        }
093    }