001    /*
002     * Copyright 2010-2014 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.when;
018    
019    import org.jetbrains.annotations.NotNull;
020    import org.jetbrains.jet.codegen.ExpressionCodegen;
021    import org.jetbrains.jet.lang.psi.JetWhenExpression;
022    import org.jetbrains.jet.lang.resolve.constants.CompileTimeConstant;
023    import org.jetbrains.jet.lang.resolve.constants.EnumValue;
024    import org.jetbrains.org.objectweb.asm.Label;
025    import org.jetbrains.org.objectweb.asm.Type;
026    
027    public class EnumSwitchCodegen extends SwitchCodegen {
028        private final WhenByEnumsMapping mapping;
029    
030        public EnumSwitchCodegen(
031                @NotNull JetWhenExpression expression,
032                boolean isStatement,
033                @NotNull ExpressionCodegen codegen,
034                @NotNull WhenByEnumsMapping mapping
035        ) {
036            super(expression, isStatement, codegen);
037            this.mapping = mapping;
038        }
039    
040        @Override
041        protected void generateSubject() {
042            codegen.getState().getMappingsClassesForWhenByEnum().generateMappingsClassForExpression(expression);
043    
044            super.generateSubject();
045            generateNullCheckIfNeeded();
046    
047            v.getstatic(
048                    mapping.getMappingsClassInternalName(),
049                    mapping.getFieldName(),
050                    MappingClassesForWhenByEnumCodegen.MAPPINGS_FIELD_DESCRIPTOR
051            );
052    
053            v.swap();
054    
055            Type enumType = codegen.getState().getTypeMapper().mapClass(mapping.getEnumClassDescriptor());
056            v.invokevirtual(enumType.getInternalName(), "ordinal", Type.getMethodDescriptor(Type.INT_TYPE), false);
057            v.aload(Type.INT_TYPE);
058        }
059    
060        @Override
061        protected void processConstant(@NotNull CompileTimeConstant constant, @NotNull Label entryLabel) {
062            assert constant instanceof EnumValue : "guaranteed by usage contract";
063            putTransitionOnce(mapping.getIndexByEntry((EnumValue) constant), entryLabel);
064        }
065    }