1 cananian 1.3.2.4 // InGen.java, created Sun Sep 13 22:49:20 1998 by cananian
2 cananian 1.2 // Copyright (C) 1998 C. Scott Ananian <cananian@alumni.princeton.edu>
3 cananian 1.2 // Licensed under the terms of the GNU GPL; see COPYING for details.
4 cananian 1.1 package harpoon.IR.Bytecode;
5 cananian 1.1
6 cananian 1.3.2.3 import harpoon.ClassFile.HClass;
7 cananian 1.1 import harpoon.Util.Util;
8 cananian 1.1
9 cananian 1.1 /**
10 cananian 1.1 * <code>InGen</code> is used for non-branching instructions.
11 cananian 1.1 * An <code>InGen</code> has an opcode and optional operands.
12 cananian 1.1 * An <code>InGen</code> has exactly one predecessor and exactly
13 cananian 1.1 * one successor.<p>
14 cananian 1.1 * Note that <code>InGen</code> contain <code>Operand</code> objects
15 cananian 1.1 * for all <b>relevant</b>, explicit or implicit operands of the
16 cananian 1.1 * bytecode instruction. This means that, for example, an
17 cananian 1.1 * <code>iload_0</code> will be given an <Code>OpLocalVariable</code>
18 cananian 1.1 * operand corresponding to the implicit '0', and conversely that
19 cananian 1.1 * <code>invokeinterface</code> will <b>not</b> contain operands for
20 cananian 1.1 * the <code>nargs</code> operand (which is obvious from the method
21 cananian 1.1 * signature) nor for the dummy placeholder value which trails the
22 cananian 1.1 * opcode in the raw bytecode array.
23 cananian 1.1 *
24 cananian 1.3.2.6 * @author C. Scott Ananian <cananian@alumni.princeton.edu>
25 cananian 1.4 * @version $Id: InGen.java,v 1.4 2002/02/25 21:04:17 cananian Exp $
26 cananian 1.1 */
27 cananian 1.1 public class InGen extends Instr {
28 cananian 1.3.2.2 final byte opcode;
29 cananian 1.3.2.2 final Operand operands[];
30 cananian 1.1
31 cananian 1.1 /** Create an <code>InGen</code> from a chunk of bytecode starting at
32 cananian 1.1 * offset <code>pc</code>. <code>parent</code> is used to lookup
33 cananian 1.1 * <code>constant_pool</code> references. */
34 cananian 1.1 public InGen(String sourcefile, int linenumber,
35 cananian 1.1 byte[] code, int pc, Code parent) {
36 cananian 1.1 super(sourcefile, linenumber);
37 cananian 1.3.2.2 this.opcode = (code[pc]==Op.WIDE)?code[pc+1]:code[pc];
38 cananian 1.1 // Make operands, if necessary.
39 cananian 1.1 switch(code[pc]) {
40 cananian 1.1 // Constant local variable index 0:
41 cananian 1.1 case Op.ALOAD_0:
42 cananian 1.1 case Op.ASTORE_0:
43 cananian 1.1 case Op.DLOAD_0:
44 cananian 1.1 case Op.DSTORE_0:
45 cananian 1.1 case Op.FLOAD_0:
46 cananian 1.1 case Op.FSTORE_0:
47 cananian 1.1 case Op.ILOAD_0:
48 cananian 1.1 case Op.ISTORE_0:
49 cananian 1.1 case Op.LLOAD_0:
50 cananian 1.1 case Op.LSTORE_0:
51 cananian 1.1 operands = new Operand[] { new OpLocalVariable(0) };
52 cananian 1.1 break;
53 cananian 1.1 // Constant local variable index 1:
54 cananian 1.1 case Op.ALOAD_1:
55 cananian 1.1 case Op.ASTORE_1:
56 cananian 1.1 case Op.DLOAD_1:
57 cananian 1.1 case Op.DSTORE_1:
58 cananian 1.1 case Op.FLOAD_1:
59 cananian 1.1 case Op.FSTORE_1:
60 cananian 1.1 case Op.ILOAD_1:
61 cananian 1.1 case Op.ISTORE_1:
62 cananian 1.1 case Op.LLOAD_1:
63 cananian 1.1 case Op.LSTORE_1:
64 cananian 1.1 operands = new Operand[] { new OpLocalVariable(1) };
65 cananian 1.1 break;
66 cananian 1.1 // Constant local variable index 2:
67 cananian 1.1 case Op.ALOAD_2:
68 cananian 1.1 case Op.ASTORE_2:
69 cananian 1.1 case Op.DLOAD_2:
70 cananian 1.1 case Op.DSTORE_2:
71 cananian 1.1 case Op.FLOAD_2:
72 cananian 1.1 case Op.FSTORE_2:
73 cananian 1.1 case Op.ILOAD_2:
74 cananian 1.1 case Op.ISTORE_2:
75 cananian 1.1 case Op.LLOAD_2:
76 cananian 1.1 case Op.LSTORE_2:
77 cananian 1.1 operands = new Operand[] { new OpLocalVariable(2) };
78 cananian 1.1 break;
79 cananian 1.1 // Constant local variable index 3:
80 cananian 1.1 case Op.ALOAD_3:
81 cananian 1.1 case Op.ASTORE_3:
82 cananian 1.1 case Op.DLOAD_3:
83 cananian 1.1 case Op.DSTORE_3:
84 cananian 1.1 case Op.FLOAD_3:
85 cananian 1.1 case Op.FSTORE_3:
86 cananian 1.1 case Op.ILOAD_3:
87 cananian 1.1 case Op.ISTORE_3:
88 cananian 1.1 case Op.LLOAD_3:
89 cananian 1.1 case Op.LSTORE_3:
90 cananian 1.1 operands = new Operand[] { new OpLocalVariable(3) };
91 cananian 1.1 break;
92 cananian 1.1 // Local variable index
93 cananian 1.1 case Op.ALOAD:
94 cananian 1.1 case Op.ASTORE:
95 cananian 1.1 case Op.DLOAD:
96 cananian 1.1 case Op.DSTORE:
97 cananian 1.1 case Op.FLOAD:
98 cananian 1.1 case Op.FSTORE:
99 cananian 1.1 case Op.ILOAD:
100 cananian 1.1 case Op.ISTORE:
101 cananian 1.1 case Op.LLOAD:
102 cananian 1.1 case Op.LSTORE:
103 cananian 1.1 operands = new Operand[] { new OpLocalVariable(u1(code,pc+1)) };
104 cananian 1.1 break;
105 cananian 1.1 // Class
106 cananian 1.1 case Op.ANEWARRAY:
107 cananian 1.1 case Op.CHECKCAST:
108 cananian 1.1 case Op.INSTANCEOF:
109 cananian 1.1 case Op.NEW:
110 cananian 1.1 operands = new Operand[] { new OpClass(parent, u2(code,pc+1)) };
111 cananian 1.1 break;
112 cananian 1.1 // Field
113 cananian 1.1 case Op.GETFIELD:
114 cananian 1.1 case Op.GETSTATIC:
115 cananian 1.1 case Op.PUTFIELD:
116 cananian 1.1 case Op.PUTSTATIC:
117 cananian 1.1 operands = new Operand[] { new OpField(parent, u2(code,pc+1)) };
118 cananian 1.1 break;
119 cananian 1.1 // Method
120 cananian 1.1 case Op.INVOKESPECIAL:
121 cananian 1.1 case Op.INVOKESTATIC:
122 cananian 1.1 case Op.INVOKEVIRTUAL:
123 cananian 1.1 case Op.INVOKEINTERFACE: // note that we discard an unnecessary operand.
124 cananian 1.1 operands = new Operand[] { new OpMethod(parent, u2(code,pc+1)) };
125 cananian 1.1 break;
126 cananian 1.1 // Byte
127 cananian 1.1 case Op.BIPUSH:
128 cananian 1.1 case Op.NEWARRAY:
129 cananian 1.1 operands = new Operand[] {
130 cananian 1.1 new OpConstant(new Byte(code[pc+1]), HClass.Byte)
131 cananian 1.1 };
132 cananian 1.1 break;
133 cananian 1.1 // Short
134 cananian 1.1 case Op.SIPUSH:
135 cananian 1.1 operands = new Operand[] {
136 cananian 1.1 new OpConstant(new Short((short)u2(code,pc+1)), HClass.Short)
137 cananian 1.1 };
138 cananian 1.1 break;
139 cananian 1.1 // Integer constant.
140 cananian 1.1 case Op.ICONST_M1:
141 cananian 1.1 case Op.ICONST_0:
142 cananian 1.1 case Op.ICONST_1:
143 cananian 1.1 case Op.ICONST_2:
144 cananian 1.1 case Op.ICONST_3:
145 cananian 1.1 case Op.ICONST_4:
146 cananian 1.1 case Op.ICONST_5:
147 cananian 1.1 operands = new Operand[] {
148 cananian 1.1 new OpConstant(new Integer((int)(code[pc]-Op.ICONST_0)), HClass.Int)
149 cananian 1.1 };
150 cananian 1.1 break;
151 cananian 1.1 // Long constant.
152 cananian 1.1 case Op.LCONST_0:
153 cananian 1.1 case Op.LCONST_1:
154 cananian 1.1 operands = new Operand[] {
155 cananian 1.1 new OpConstant(new Long((long)(code[pc]-Op.LCONST_0)), HClass.Long)
156 cananian 1.1 };
157 cananian 1.1 break;
158 cananian 1.1 // Floating-point constant.
159 cananian 1.1 case Op.FCONST_0:
160 cananian 1.1 case Op.FCONST_1:
161 cananian 1.1 case Op.FCONST_2:
162 cananian 1.1 operands = new Operand[] {
163 cananian 1.1 new OpConstant(new Float((float)(code[pc]-Op.FCONST_0)), HClass.Float)
164 cananian 1.3 };
165 cananian 1.3 break;
166 cananian 1.3 // Double constant.
167 cananian 1.3 case Op.DCONST_0:
168 cananian 1.3 case Op.DCONST_1:
169 cananian 1.3 operands = new Operand[] {
170 cananian 1.3 new OpConstant(new Double((double)(code[pc]-Op.DCONST_0)),
171 cananian 1.3 HClass.Double)
172 cananian 1.1 };
173 cananian 1.1 break;
174 cananian 1.1 // General constant.
175 cananian 1.1 case Op.LDC:
176 cananian 1.1 operands = new Operand[] { new OpConstant(parent, u1(code,pc+1)) };
177 cananian 1.1 break;
178 cananian 1.1 case Op.LDC_W:
179 cananian 1.1 case Op.LDC2_W:
180 cananian 1.1 operands = new Operand[] { new OpConstant(parent, u2(code,pc+1)) };
181 cananian 1.1 break;
182 cananian 1.1 // Odd-balls
183 cananian 1.1 case Op.IINC:
184 cananian 1.1 operands = new Operand[] {
185 cananian 1.1 new OpLocalVariable(u1(code,pc+1)),
186 cananian 1.1 new OpConstant(new Integer((int)code[pc+2]), HClass.Int)
187 cananian 1.1 };
188 cananian 1.1 break;
189 cananian 1.1 case Op.MULTIANEWARRAY:
190 cananian 1.1 operands = new Operand[] {
191 cananian 1.1 new OpClass(parent, u2(code,pc+1)),
192 cananian 1.1 new OpConstant(new Integer(u1(code,pc+3)), HClass.Int)
193 cananian 1.1 };
194 cananian 1.1 break;
195 cananian 1.1 case Op.RET:
196 cananian 1.1 operands = new Operand[] {
197 cananian 1.1 new OpConstant(new Integer(u1(code,pc+1)), HClass.Int)
198 cananian 1.1 };
199 cananian 1.1 break;
200 cananian 1.1 case Op.WIDE: // this is evil.
201 cananian 1.1 if (code[pc+1]==Op.IINC) // very evil.
202 cananian 1.1 operands = new Operand[] {
203 cananian 1.3.2.2 new OpLocalVariable(u2(code, pc+2)),
204 cananian 1.3.2.5 new OpConstant(new Integer(s2(code,pc+4)), HClass.Int)
205 cananian 1.1 };
206 cananian 1.3.2.2 else
207 cananian 1.3.2.2 operands = new Operand[] { new OpLocalVariable(u2(code, pc+2)) };
208 cananian 1.1 break;
209 cananian 1.1 // Takes an operand, but don't belong:
210 cananian 1.1 case Op.GOTO:
211 cananian 1.1 case Op.GOTO_W:
212 cananian 1.1 case Op.IF_ACMPEQ:
213 cananian 1.1 case Op.IF_ACMPNE:
214 cananian 1.1 case Op.IF_ICMPEQ:
215 cananian 1.1 case Op.IF_ICMPNE:
216 cananian 1.1 case Op.IF_ICMPLT:
217 cananian 1.1 case Op.IF_ICMPGE:
218 cananian 1.1 case Op.IF_ICMPGT:
219 cananian 1.1 case Op.IF_ICMPLE:
220 cananian 1.1 case Op.IFEQ:
221 cananian 1.1 case Op.IFNE:
222 cananian 1.1 case Op.IFLT:
223 cananian 1.1 case Op.IFGE:
224 cananian 1.1 case Op.IFGT:
225 cananian 1.1 case Op.IFLE:
226 cananian 1.1 case Op.IFNONNULL:
227 cananian 1.1 case Op.IFNULL:
228 cananian 1.1 case Op.JSR:
229 cananian 1.1 case Op.JSR_W:
230 cananian 1.1 case Op.LOOKUPSWITCH:
231 cananian 1.1 case Op.TABLESWITCH:
232 cananian 1.1 throw new Error("Branch operations are not InGen's.");
233 cananian 1.1 default:
234 cananian 1.1 operands = new Operand[0];
235 cananian 1.1 break;
236 cananian 1.1 }
237 cananian 1.1 // done. yay.
238 cananian 1.1 }
239 cananian 1.1 /** Create an integer from an unsigned byte. */
240 cananian 1.1 static int u1(byte[] code, int pc) {
241 cananian 1.1 return ((int) code[pc]) & 0xFF;
242 cananian 1.1 }
243 cananian 1.1 /** Create an integer from an unsigned two-byte quantity (big-endian). */
244 cananian 1.1 static int u2(byte[] code, int pc) {
245 cananian 1.1 return (u1(code,pc) << 8) | u1(code,pc+1);
246 cananian 1.1 }
247 cananian 1.3.2.5 /** Create an integer from a signed two-byte quantity (big-endian). */
248 cananian 1.3.2.5 static int s2(byte[] code, int pc) {
249 cananian 1.3.2.5 int s = u2(code, pc);
250 cananian 1.3.2.5 return (s&0x8000)==0 ? s : (s | ~0xFFFF);
251 cananian 1.1 }
252 cananian 1.1
253 cananian 1.1 /** Return the bytecode opcode of this instruction.
254 cananian 1.1 * @see Op */
255 cananian 1.1 public byte getOpcode() { return opcode; }
256 cananian 1.1 /** Return a specific operand of this instruction. */
257 cananian 1.1 public Operand getOperand(int i) { return operands[i]; }
258 cananian 1.1 /** Get all the operands of this instruction. */
259 cananian 1.3.2.1 public Operand[] getOperands() {
260 cananian 1.3.2.1 return (Operand[]) Util.safeCopy(Operand.arrayFactory, operands);
261 cananian 1.3.2.1 }
262 cananian 1.1
263 cananian 1.1 // provide run-time checks on arity.
264 cananian 1.1 /** @see Instr#addPrev */
265 cananian 1.1 void addPrev(Instr prev) {
266 cananian 1.1 if (this.prev.size()>=1)
267 cananian 1.1 throw new Error("Only one predecessor for InGen allowed.");
268 cananian 1.1 super.addPrev(prev);
269 cananian 1.1 }
270 cananian 1.1 /** @see Instr#addNext */
271 cananian 1.1 void addNext(Instr next) {
272 cananian 1.1 if (this.next.size()>=1)
273 cananian 1.1 throw new Error("Only one successor for InGen allowed.");
274 cananian 1.1 super.addNext(next);
275 cananian 1.1 }
276 cananian 1.1
277 cananian 1.1 /** Return human-readable instruction string. */
278 cananian 1.1 public String toString() {
279 cananian 1.1 StringBuffer sb = new StringBuffer(Op.toString(opcode));
280 cananian 1.1 sb.append(' ');
281 cananian 1.1 for (int i=0; i<operands.length; i++) {
282 cananian 1.1 sb.append(operands[i].toString());
283 cananian 1.1 if (i<operands.length-1)
284 cananian 1.1 sb.append(", ");
285 cananian 1.1 }
286 cananian 1.1 return sb.toString();
287 cananian 1.1 }
288 cananian 1.1
289 cananian 1.1 }