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.inline;
018
019 import org.jetbrains.annotations.NotNull;
020 import org.jetbrains.annotations.Nullable;
021 import org.jetbrains.kotlin.codegen.StackValue;
022 import org.jetbrains.kotlin.resolve.jvm.AsmTypes;
023 import org.jetbrains.org.objectweb.asm.Label;
024 import org.jetbrains.org.objectweb.asm.MethodVisitor;
025 import org.jetbrains.org.objectweb.asm.Opcodes;
026 import org.jetbrains.org.objectweb.asm.commons.InstructionAdapter;
027
028 import static org.jetbrains.kotlin.codegen.inline.LocalVarRemapper.RemapStatus.*;
029
030 public class LocalVarRemapper {
031 private final Parameters params;
032 private final int actualParamsSize;
033 private final StackValue[] remapValues;
034 private final int additionalShift;
035
036 public LocalVarRemapper(@NotNull Parameters params, int additionalShift) {
037 this.additionalShift = additionalShift;
038 this.params = params;
039
040 remapValues = new StackValue[params.getArgsSizeOnStack()];
041
042 int realSize = 0;
043 for (ParameterInfo info : params) {
044 Integer shift = params.getDeclarationSlot(info);
045 if (!info.isSkippedOrRemapped()) {
046 remapValues[shift] = StackValue.local(realSize, AsmTypes.OBJECT_TYPE);
047 realSize += info.getType().getSize();
048 }
049 else {
050 remapValues[shift] = info.isRemapped() ? info.getRemapValue() : null;
051 }
052 }
053
054 actualParamsSize = realSize;
055 }
056
057 @NotNull
058 private RemapInfo doRemap(int index) {
059 int remappedIndex;
060
061 if (index < params.getArgsSizeOnStack()) {
062 ParameterInfo info = params.getParameterByDeclarationSlot(index);
063 StackValue remapped = remapValues[index];
064 if (info.isSkipped || remapped == null) {
065 return new RemapInfo(info);
066 }
067 if (info.isRemapped()) {
068 return new RemapInfo(remapped, info, REMAPPED);
069 }
070 else {
071 remappedIndex = ((StackValue.Local) remapped).index;
072 }
073 }
074 else {
075 //captured params are not used directly in this inlined method, they are used in closure
076 remappedIndex = actualParamsSize - params.getArgsSizeOnStack() + index;
077 }
078
079 return new RemapInfo(StackValue.local(remappedIndex + additionalShift, AsmTypes.OBJECT_TYPE), null, SHIFT);
080 }
081
082 @NotNull
083 public RemapInfo remap(int index) {
084 RemapInfo info = doRemap(index);
085 if (FAIL == info.status) {
086 assert info.parameterInfo != null : "Parameter info should be not null";
087 throw new RuntimeException("Trying to access skipped parameter: " + info.parameterInfo.type + " at " +index);
088 }
089 return info;
090 }
091
092 public void visitIincInsn(int var, int increment, @NotNull MethodVisitor mv) {
093 RemapInfo remap = remap(var);
094 assert remap.value instanceof StackValue.Local : "Remapped value should be a local: " + remap.value;
095 mv.visitIincInsn(((StackValue.Local) remap.value).index, increment);
096 }
097
098 public void visitLocalVariable(
099 @NotNull String name,
100 @NotNull String desc,
101 @Nullable String signature,
102 @NotNull Label start,
103 @NotNull Label end,
104 int index,
105 MethodVisitor mv
106 ) {
107 RemapInfo info = doRemap(index);
108 //add entries only for shifted vars
109 if (SHIFT == info.status) {
110 mv.visitLocalVariable(name, desc, signature, start, end, ((StackValue.Local) info.value).index);
111 }
112 }
113
114 public void visitVarInsn(int opcode, int var, @NotNull InstructionAdapter mv) {
115 RemapInfo remapInfo = remap(var);
116 StackValue value = remapInfo.value;
117 if (value instanceof StackValue.Local) {
118 if (remapInfo.parameterInfo != null) {
119 //All remapped value parameters can't be rewritten except case of default ones.
120 //On remapping default parameter to actual value there is only one instruction that writes to it according to mask value
121 //but if such parameter remapped then it passed and this mask branch code never executed
122 //TODO add assertion about parameter default value: descriptor is required
123 opcode = value.type.getOpcode(InlineCodegenUtil.isStoreInstruction(opcode) ? Opcodes.ISTORE : Opcodes.ILOAD);
124 }
125 mv.visitVarInsn(opcode, ((StackValue.Local) value).index);
126 if (remapInfo.parameterInfo != null) {
127 StackValue.coerce(value.type, remapInfo.parameterInfo.type, mv);
128 }
129 }
130 else {
131 assert remapInfo.parameterInfo != null : "Non local value should have parameter info";
132 value.put(remapInfo.parameterInfo.type, mv);
133 }
134 }
135
136 public enum RemapStatus {
137 SHIFT,
138 REMAPPED,
139 FAIL
140 }
141
142 public static class RemapInfo {
143 public final StackValue value;
144 public final ParameterInfo parameterInfo;
145 public final RemapStatus status;
146
147 public RemapInfo(@NotNull StackValue value, @Nullable ParameterInfo parameterInfo, @NotNull RemapStatus remapStatus) {
148 this.value = value;
149 this.parameterInfo = parameterInfo;
150 this.status = remapStatus;
151 }
152
153 public RemapInfo(@NotNull ParameterInfo parameterInfo) {
154 this.value = null;
155 this.parameterInfo = parameterInfo;
156 this.status = FAIL;
157 }
158 }
159 }