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.asm4.MethodVisitor;
021    import org.jetbrains.asm4.Type;
022    import org.jetbrains.jet.codegen.context.MethodContext;
023    import org.jetbrains.jet.codegen.signature.JvmMethodSignature;
024    import org.jetbrains.jet.codegen.state.GenerationState;
025    import org.jetbrains.jet.codegen.state.JetTypeMapper;
026    import org.jetbrains.jet.lang.descriptors.CallableDescriptor;
027    import org.jetbrains.jet.lang.psi.JetDeclarationWithBody;
028    
029    import java.util.ArrayList;
030    import java.util.Collection;
031    
032    public abstract class FunctionGenerationStrategy {
033    
034        private final Collection<String> localVariableNames = new ArrayList<String>();
035    
036        private FrameMap frameMap;
037    
038        public abstract void generateBody(
039                @NotNull MethodVisitor mv,
040                @NotNull JvmMethodSignature signature,
041                @NotNull MethodContext context
042        );
043    
044        protected void addLocalVariableName(@NotNull String name) {
045            localVariableNames.add(name);
046        }
047    
048        @NotNull
049        public Collection<String> getLocalVariableNames() {
050            return localVariableNames;
051        }
052    
053        @NotNull
054        protected FrameMap createFrameMap(@NotNull JetTypeMapper typeMapper, @NotNull MethodContext context) {
055            return context.prepareFrame(typeMapper);
056        }
057    
058        @NotNull
059        public FrameMap getFrameMap(@NotNull JetTypeMapper typeMapper, @NotNull MethodContext context) {
060            if (frameMap == null) {
061                frameMap = createFrameMap(typeMapper, context);
062            }
063            return frameMap;
064        }
065    
066        public static class FunctionDefault extends CodegenBased<CallableDescriptor> {
067    
068            private final JetDeclarationWithBody declaration;
069    
070            public FunctionDefault(
071                    @NotNull GenerationState state,
072                    @NotNull CallableDescriptor descriptor,
073                    @NotNull JetDeclarationWithBody declaration
074            ) {
075                super(state, descriptor);
076                this.declaration = declaration;
077            }
078    
079            @Override
080            public void doGenerateBody(@NotNull ExpressionCodegen codegen, @NotNull JvmMethodSignature signature) {
081                codegen.returnExpression(declaration.getBodyExpression());
082            }
083        }
084    
085        public abstract static class CodegenBased<T extends CallableDescriptor> extends FunctionGenerationStrategy {
086    
087            protected final GenerationState state;
088    
089            protected final T callableDescriptor;
090    
091            public CodegenBased(@NotNull GenerationState state, T callableDescriptor) {
092                this.state = state;
093                this.callableDescriptor = callableDescriptor;
094            }
095    
096            @Override
097            public void generateBody(
098                    @NotNull MethodVisitor mv,
099                    @NotNull JvmMethodSignature signature,
100                    @NotNull MethodContext context
101            ) {
102                ExpressionCodegen codegen = initializeExpressionCodegen(signature, context, mv, signature.getAsmMethod().getReturnType());
103                doGenerateBody(codegen, signature);
104                generateLocalVarNames(codegen);
105            }
106    
107            abstract public void doGenerateBody(@NotNull ExpressionCodegen codegen, @NotNull JvmMethodSignature signature);
108    
109            @NotNull
110            public ExpressionCodegen initializeExpressionCodegen(
111                    JvmMethodSignature signature,
112                    MethodContext context,
113                    MethodVisitor mv,
114                    Type returnType
115            ) {
116                return new ExpressionCodegen(mv, getFrameMap(state.getTypeMapper(), context), returnType, context, state);
117            }
118    
119            public void generateLocalVarNames(@NotNull ExpressionCodegen codegen) {
120                for (String name : codegen.getLocalVariableNamesForExpression()) {
121                    addLocalVariableName(name);
122                }
123            }
124        }
125    }