1 /*
2 * Copyright (c) 2017, 2020, Oracle and/or its affiliates. All rights reserved.
3 */
4 /*
5 * Licensed to the Apache Software Foundation (ASF) under one or more
6 * contributor license agreements. See the NOTICE file distributed with
7 * this work for additional information regarding copyright ownership.
8 * The ASF licenses this file to You under the Apache License, Version 2.0
9 * (the "License"); you may not use this file except in compliance with
10 * the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS,
16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17 * See the License for the specific language governing permissions and
18 * limitations under the License.
19 */
20
21 package com.sun.org.apache.bcel.internal.util;
22
23 import java.io.PrintWriter;
24 import java.util.ArrayList;
25 import java.util.HashMap;
26 import java.util.List;
27 import java.util.Locale;
28 import java.util.Map;
29
30 import com.sun.org.apache.bcel.internal.Const;
31 import com.sun.org.apache.bcel.internal.classfile.Utility;
32 import com.sun.org.apache.bcel.internal.generic.AllocationInstruction;
33 import com.sun.org.apache.bcel.internal.generic.ArrayInstruction;
34 import com.sun.org.apache.bcel.internal.generic.ArrayType;
35 import com.sun.org.apache.bcel.internal.generic.BranchHandle;
36 import com.sun.org.apache.bcel.internal.generic.BranchInstruction;
37 import com.sun.org.apache.bcel.internal.generic.CHECKCAST;
38 import com.sun.org.apache.bcel.internal.generic.CPInstruction;
39 import com.sun.org.apache.bcel.internal.generic.CodeExceptionGen;
40 import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
41 import com.sun.org.apache.bcel.internal.generic.ConstantPushInstruction;
42 import com.sun.org.apache.bcel.internal.generic.EmptyVisitor;
43 import com.sun.org.apache.bcel.internal.generic.FieldInstruction;
44 import com.sun.org.apache.bcel.internal.generic.IINC;
45 import com.sun.org.apache.bcel.internal.generic.INSTANCEOF;
46 import com.sun.org.apache.bcel.internal.generic.Instruction;
47 import com.sun.org.apache.bcel.internal.generic.InstructionConst;
48 import com.sun.org.apache.bcel.internal.generic.InstructionHandle;
49 import com.sun.org.apache.bcel.internal.generic.InvokeInstruction;
50 import com.sun.org.apache.bcel.internal.generic.LDC;
51 import com.sun.org.apache.bcel.internal.generic.LDC2_W;
52 import com.sun.org.apache.bcel.internal.generic.LocalVariableInstruction;
53 import com.sun.org.apache.bcel.internal.generic.MULTIANEWARRAY;
54 import com.sun.org.apache.bcel.internal.generic.MethodGen;
55 import com.sun.org.apache.bcel.internal.generic.NEWARRAY;
56 import com.sun.org.apache.bcel.internal.generic.ObjectType;
57 import com.sun.org.apache.bcel.internal.generic.RET;
58 import com.sun.org.apache.bcel.internal.generic.ReturnInstruction;
59 import com.sun.org.apache.bcel.internal.generic.Select;
60 import com.sun.org.apache.bcel.internal.generic.Type;
61
62 /**
63 * Factory creates il.append() statements, and sets instruction targets.
64 * A helper class for BCELifier.
65 *
66 * @see BCELifier
67 * @LastModified: Jan 2020
68 */
69 class BCELFactory extends EmptyVisitor {
70
71 private static final String CONSTANT_PREFIX = Const.class.getSimpleName()+".";
72 private final MethodGen _mg;
73 private final PrintWriter _out;
74 private final ConstantPoolGen _cp;
75
76
77 BCELFactory(final MethodGen mg, final PrintWriter out) {
78 _mg = mg;
79 _cp = mg.getConstantPool();
80 _out = out;
81 }
82
83 private final Map<Instruction, InstructionHandle> branch_map = new HashMap<>();
84
85
86 public void start() {
87 if (!_mg.isAbstract() && !_mg.isNative()) {
88 for (InstructionHandle ih = _mg.getInstructionList().getStart(); ih != null; ih = ih
89 .getNext()) {
90 final Instruction i = ih.getInstruction();
91 if (i instanceof BranchInstruction) {
92 branch_map.put(i, ih); // memorize container
93 }
94 if (ih.hasTargeters()) {
95 if (i instanceof BranchInstruction) {
96 _out.println(" InstructionHandle ih_" + ih.getPosition() + ";");
97 } else {
98 _out.print(" InstructionHandle ih_" + ih.getPosition() + " = ");
99 }
100 } else {
101 _out.print(" ");
102 }
103 if (!visitInstruction(i)) {
104 i.accept(this);
105 }
106 }
107 updateBranchTargets();
108 updateExceptionHandlers();
109 }
110 }
111
112
113 private boolean visitInstruction( final Instruction i ) {
114 final short opcode = i.getOpcode();
115 if ((InstructionConst.getInstruction(opcode) != null)
116 && !(i instanceof ConstantPushInstruction) && !(i instanceof ReturnInstruction)) { // Handled below
117 _out.println("il.append(InstructionConst."
118 + i.getName().toUpperCase(Locale.ENGLISH) + ");");
119 return true;
120 }
121 return false;
122 }
123
124
125 @Override
126 public void visitLocalVariableInstruction( final LocalVariableInstruction i ) {
127 final short opcode = i.getOpcode();
128 final Type type = i.getType(_cp);
129 if (opcode == Const.IINC) {
130 _out.println("il.append(new IINC(" + i.getIndex() + ", " + ((IINC) i).getIncrement()
131 + "));");
132 } else {
133 final String kind = (opcode < Const.ISTORE) ? "Load" : "Store";
134 _out.println("il.append(_factory.create" + kind + "(" + BCELifier.printType(type)
135 + ", " + i.getIndex() + "));");
136 }
137 }
138
139
140 @Override
141 public void visitArrayInstruction( final ArrayInstruction i ) {
142 final short opcode = i.getOpcode();
143 final Type type = i.getType(_cp);
144 final String kind = (opcode < Const.IASTORE) ? "Load" : "Store";
145 _out.println("il.append(_factory.createArray" + kind + "(" + BCELifier.printType(type)
146 + "));");
147 }
148
149
150 @Override
151 public void visitFieldInstruction( final FieldInstruction i ) {
152 final short opcode = i.getOpcode();
153 final String class_name = i.getReferenceType(_cp).getSignature();
154 final String field_name = i.getFieldName(_cp);
155 final Type type = i.getFieldType(_cp);
156 _out.println("il.append(_factory.createFieldAccess(\"" + class_name + "\", \"" + field_name
157 + "\", " + BCELifier.printType(type) + ", " + CONSTANT_PREFIX
158 + Const.getOpcodeName(opcode).toUpperCase(Locale.ENGLISH) + "));");
159 }
160
161
162 @Override
163 public void visitInvokeInstruction( final InvokeInstruction i ) {
164 final short opcode = i.getOpcode();
165 final String class_name = i.getReferenceType(_cp).getSignature();
166 final String method_name = i.getMethodName(_cp);
167 final Type type = i.getReturnType(_cp);
168 final Type[] arg_types = i.getArgumentTypes(_cp);
169 _out.println("il.append(_factory.createInvoke(\"" + class_name + "\", \"" + method_name
170 + "\", " + BCELifier.printType(type) + ", "
171 + BCELifier.printArgumentTypes(arg_types) + ", " + CONSTANT_PREFIX
172 + Const.getOpcodeName(opcode).toUpperCase(Locale.ENGLISH) + "));");
173 }
174
175
176 @Override
177 @SuppressWarnings("fallthrough") // by design for case Const.ANEWARRAY
178 public void visitAllocationInstruction( final AllocationInstruction i ) {
179 Type type;
180 if (i instanceof CPInstruction) {
181 type = ((CPInstruction) i).getType(_cp);
182 } else {
183 type = ((NEWARRAY) i).getType();
184 }
185 final short opcode = ((Instruction) i).getOpcode();
186 int dim = 1;
187 switch (opcode) {
188 case Const.NEW:
189 _out.println("il.append(_factory.createNew(\"" + ((ObjectType) type).getClassName()
190 + "\"));");
191 break;
192 case Const.MULTIANEWARRAY:
193 dim = ((MULTIANEWARRAY) i).getDimensions();
194 //$FALL-THROUGH$
195 case Const.ANEWARRAY:
196 case Const.NEWARRAY:
197 if (type instanceof ArrayType) {
198 type = ((ArrayType) type).getBasicType();
199 }
200 _out.println("il.append(_factory.createNewArray(" + BCELifier.printType(type)
201 + ", (short) " + dim + "));");
202 break;
203 default:
204 throw new RuntimeException("Oops: " + opcode);
205 }
206 }
207
208
209 private void createConstant( final Object value ) {
210 String embed = value.toString();
211 if (value instanceof String) {
212 embed = '"' + Utility.convertString(embed) + '"';
213 } else if (value instanceof Character) {
214 embed = "(char)0x" + Integer.toHexString(((Character) value).charValue());
215 } else if (value instanceof Float) {
216 embed += "f";
217 } else if (value instanceof Long) {
218 embed += "L";
219 } else if (value instanceof ObjectType) {
220 final ObjectType ot = (ObjectType) value;
221 embed = "new ObjectType(\""+ot.getClassName()+"\")";
222 }
223
224 _out.println("il.append(new PUSH(_cp, " + embed + "));");
225 }
226
227
228 @Override
229 public void visitLDC( final LDC i ) {
230 createConstant(i.getValue(_cp));
231 }
232
233
234 @Override
235 public void visitLDC2_W( final LDC2_W i ) {
236 createConstant(i.getValue(_cp));
237 }
238
239
240 @Override
241 public void visitConstantPushInstruction( final ConstantPushInstruction i ) {
242 createConstant(i.getValue());
243 }
244
245
246 @Override
247 public void visitINSTANCEOF( final INSTANCEOF i ) {
248 final Type type = i.getType(_cp);
249 _out.println("il.append(new INSTANCEOF(_cp.addClass(" + BCELifier.printType(type) + ")));");
250 }
251
252
253 @Override
254 public void visitCHECKCAST( final CHECKCAST i ) {
255 final Type type = i.getType(_cp);
256 _out.println("il.append(_factory.createCheckCast(" + BCELifier.printType(type) + "));");
257 }
258
259
260 @Override
261 public void visitReturnInstruction( final ReturnInstruction i ) {
262 final Type type = i.getType(_cp);
263 _out.println("il.append(_factory.createReturn(" + BCELifier.printType(type) + "));");
264 }
265
266 // Memorize BranchInstructions that need an update
267 private final List<BranchInstruction> branches = new ArrayList<>();
268
269
270 @Override
271 public void visitBranchInstruction( final BranchInstruction bi ) {
272 final BranchHandle bh = (BranchHandle) branch_map.get(bi);
273 final int pos = bh.getPosition();
274 final String name = bi.getName() + "_" + pos;
275 if (bi instanceof Select) {
276 final Select s = (Select) bi;
277 branches.add(bi);
278 final StringBuilder args = new StringBuilder("new int[] { ");
279 final int[] matchs = s.getMatchs();
280 for (int i = 0; i < matchs.length; i++) {
281 args.append(matchs[i]);
282 if (i < matchs.length - 1) {
283 args.append(", ");
284 }
285 }
286 args.append(" }");
287 _out.print("Select " + name + " = new " + bi.getName().toUpperCase(Locale.ENGLISH)
288 + "(" + args + ", new InstructionHandle[] { ");
289 for (int i = 0; i < matchs.length; i++) {
290 _out.print("null");
291 if (i < matchs.length - 1) {
292 _out.print(", ");
293 }
294 }
295 _out.println(" }, null);");
296 } else {
297 final int t_pos = bh.getTarget().getPosition();
298 String target;
299 if (pos > t_pos) {
300 target = "ih_" + t_pos;
301 } else {
302 branches.add(bi);
303 target = "null";
304 }
305 _out.println(" BranchInstruction " + name + " = _factory.createBranchInstruction("
306 + CONSTANT_PREFIX + bi.getName().toUpperCase(Locale.ENGLISH) + ", " + target
307 + ");");
308 }
309 if (bh.hasTargeters()) {
310 _out.println(" ih_" + pos + " = il.append(" + name + ");");
311 } else {
312 _out.println(" il.append(" + name + ");");
313 }
314 }
315
316
317 @Override
318 public void visitRET( final RET i ) {
319 _out.println("il.append(new RET(" + i.getIndex() + ")));");
320 }
321
322
323 private void updateBranchTargets() {
324 for (final BranchInstruction bi : branches) {
325 final BranchHandle bh = (BranchHandle) branch_map.get(bi);
326 final int pos = bh.getPosition();
327 final String name = bi.getName() + "_" + pos;
328 int t_pos = bh.getTarget().getPosition();
329 _out.println(" " + name + ".setTarget(ih_" + t_pos + ");");
330 if (bi instanceof Select) {
331 final InstructionHandle[] ihs = ((Select) bi).getTargets();
332 for (int j = 0; j < ihs.length; j++) {
333 t_pos = ihs[j].getPosition();
334 _out.println(" " + name + ".setTarget(" + j + ", ih_" + t_pos + ");");
335 }
336 }
337 }
338 }
339
340
341 private void updateExceptionHandlers() {
342 final CodeExceptionGen[] handlers = _mg.getExceptionHandlers();
343 for (final CodeExceptionGen h : handlers) {
344 final String type = (h.getCatchType() == null) ? "null" : BCELifier.printType(h
345 .getCatchType());
346 _out.println(" method.addExceptionHandler(" + "ih_" + h.getStartPC().getPosition()
347 + ", " + "ih_" + h.getEndPC().getPosition() + ", " + "ih_"
348 + h.getHandlerPC().getPosition() + ", " + type + ");");
349 }
350 }
351 }