Mon, 03 Jun 2013 17:09:26 -0700
8006615: [doclint] move remaining messages into resource bundle
Reviewed-by: mcimadamore, vromero
1 /*
2 * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
26 package com.sun.tools.javac.comp;
28 import com.sun.tools.javac.code.*;
29 import com.sun.tools.javac.jvm.*;
30 import com.sun.tools.javac.util.*;
32 import static com.sun.tools.javac.code.TypeTag.BOOLEAN;
34 import static com.sun.tools.javac.jvm.ByteCodes.*;
36 /** Helper class for constant folding, used by the attribution phase.
37 * This class is marked strictfp as mandated by JLS 15.4.
38 *
39 * <p><b>This is NOT part of any supported API.
40 * If you write code that depends on this, you do so at your own risk.
41 * This code and its internal interfaces are subject to change or
42 * deletion without notice.</b>
43 */
44 strictfp class ConstFold {
45 protected static final Context.Key<ConstFold> constFoldKey =
46 new Context.Key<ConstFold>();
48 private Symtab syms;
50 public static ConstFold instance(Context context) {
51 ConstFold instance = context.get(constFoldKey);
52 if (instance == null)
53 instance = new ConstFold(context);
54 return instance;
55 }
57 private ConstFold(Context context) {
58 context.put(constFoldKey, this);
60 syms = Symtab.instance(context);
61 }
63 static final Integer minusOne = -1;
64 static final Integer zero = 0;
65 static final Integer one = 1;
67 /** Convert boolean to integer (true = 1, false = 0).
68 */
69 private static Integer b2i(boolean b) {
70 return b ? one : zero;
71 }
72 private static int intValue(Object x) { return ((Number)x).intValue(); }
73 private static long longValue(Object x) { return ((Number)x).longValue(); }
74 private static float floatValue(Object x) { return ((Number)x).floatValue(); }
75 private static double doubleValue(Object x) { return ((Number)x).doubleValue(); }
77 /** Fold binary or unary operation, returning constant type reflecting the
78 * operations result. Return null if fold failed due to an
79 * arithmetic exception.
80 * @param opcode The operation's opcode instruction (usually a byte code),
81 * as entered by class Symtab.
82 * @param argtypes The operation's argument types (a list of length 1 or 2).
83 * Argument types are assumed to have non-null constValue's.
84 */
85 Type fold(int opcode, List<Type> argtypes) {
86 int argCount = argtypes.length();
87 if (argCount == 1)
88 return fold1(opcode, argtypes.head);
89 else if (argCount == 2)
90 return fold2(opcode, argtypes.head, argtypes.tail.head);
91 else
92 throw new AssertionError();
93 }
95 /** Fold unary operation.
96 * @param opcode The operation's opcode instruction (usually a byte code),
97 * as entered by class Symtab.
98 * opcode's ifeq to ifge are for postprocessing
99 * xcmp; ifxx pairs of instructions.
100 * @param operand The operation's operand type.
101 * Argument types are assumed to have non-null constValue's.
102 */
103 Type fold1(int opcode, Type operand) {
104 try {
105 Object od = operand.constValue();
106 switch (opcode) {
107 case nop:
108 return operand;
109 case ineg: // unary -
110 return syms.intType.constType(-intValue(od));
111 case ixor: // ~
112 return syms.intType.constType(~intValue(od));
113 case bool_not: // !
114 return syms.booleanType.constType(b2i(intValue(od) == 0));
115 case ifeq:
116 return syms.booleanType.constType(b2i(intValue(od) == 0));
117 case ifne:
118 return syms.booleanType.constType(b2i(intValue(od) != 0));
119 case iflt:
120 return syms.booleanType.constType(b2i(intValue(od) < 0));
121 case ifgt:
122 return syms.booleanType.constType(b2i(intValue(od) > 0));
123 case ifle:
124 return syms.booleanType.constType(b2i(intValue(od) <= 0));
125 case ifge:
126 return syms.booleanType.constType(b2i(intValue(od) >= 0));
128 case lneg: // unary -
129 return syms.longType.constType(new Long(-longValue(od)));
130 case lxor: // ~
131 return syms.longType.constType(new Long(~longValue(od)));
133 case fneg: // unary -
134 return syms.floatType.constType(new Float(-floatValue(od)));
136 case dneg: // ~
137 return syms.doubleType.constType(new Double(-doubleValue(od)));
139 default:
140 return null;
141 }
142 } catch (ArithmeticException e) {
143 return null;
144 }
145 }
147 /** Fold binary operation.
148 * @param opcode The operation's opcode instruction (usually a byte code),
149 * as entered by class Symtab.
150 * opcode's ifeq to ifge are for postprocessing
151 * xcmp; ifxx pairs of instructions.
152 * @param left The type of the operation's left operand.
153 * @param right The type of the operation's right operand.
154 */
155 Type fold2(int opcode, Type left, Type right) {
156 try {
157 if (opcode > ByteCodes.preMask) {
158 // we are seeing a composite instruction of the form xcmp; ifxx.
159 // In this case fold both instructions separately.
160 Type t1 = fold2(opcode >> ByteCodes.preShift, left, right);
161 return (t1.constValue() == null) ? t1
162 : fold1(opcode & ByteCodes.preMask, t1);
163 } else {
164 Object l = left.constValue();
165 Object r = right.constValue();
166 switch (opcode) {
167 case iadd:
168 return syms.intType.constType(intValue(l) + intValue(r));
169 case isub:
170 return syms.intType.constType(intValue(l) - intValue(r));
171 case imul:
172 return syms.intType.constType(intValue(l) * intValue(r));
173 case idiv:
174 return syms.intType.constType(intValue(l) / intValue(r));
175 case imod:
176 return syms.intType.constType(intValue(l) % intValue(r));
177 case iand:
178 return (left.hasTag(BOOLEAN)
179 ? syms.booleanType : syms.intType)
180 .constType(intValue(l) & intValue(r));
181 case bool_and:
182 return syms.booleanType.constType(b2i((intValue(l) & intValue(r)) != 0));
183 case ior:
184 return (left.hasTag(BOOLEAN)
185 ? syms.booleanType : syms.intType)
186 .constType(intValue(l) | intValue(r));
187 case bool_or:
188 return syms.booleanType.constType(b2i((intValue(l) | intValue(r)) != 0));
189 case ixor:
190 return (left.hasTag(BOOLEAN)
191 ? syms.booleanType : syms.intType)
192 .constType(intValue(l) ^ intValue(r));
193 case ishl: case ishll:
194 return syms.intType.constType(intValue(l) << intValue(r));
195 case ishr: case ishrl:
196 return syms.intType.constType(intValue(l) >> intValue(r));
197 case iushr: case iushrl:
198 return syms.intType.constType(intValue(l) >>> intValue(r));
199 case if_icmpeq:
200 return syms.booleanType.constType(
201 b2i(intValue(l) == intValue(r)));
202 case if_icmpne:
203 return syms.booleanType.constType(
204 b2i(intValue(l) != intValue(r)));
205 case if_icmplt:
206 return syms.booleanType.constType(
207 b2i(intValue(l) < intValue(r)));
208 case if_icmpgt:
209 return syms.booleanType.constType(
210 b2i(intValue(l) > intValue(r)));
211 case if_icmple:
212 return syms.booleanType.constType(
213 b2i(intValue(l) <= intValue(r)));
214 case if_icmpge:
215 return syms.booleanType.constType(
216 b2i(intValue(l) >= intValue(r)));
218 case ladd:
219 return syms.longType.constType(
220 new Long(longValue(l) + longValue(r)));
221 case lsub:
222 return syms.longType.constType(
223 new Long(longValue(l) - longValue(r)));
224 case lmul:
225 return syms.longType.constType(
226 new Long(longValue(l) * longValue(r)));
227 case ldiv:
228 return syms.longType.constType(
229 new Long(longValue(l) / longValue(r)));
230 case lmod:
231 return syms.longType.constType(
232 new Long(longValue(l) % longValue(r)));
233 case land:
234 return syms.longType.constType(
235 new Long(longValue(l) & longValue(r)));
236 case lor:
237 return syms.longType.constType(
238 new Long(longValue(l) | longValue(r)));
239 case lxor:
240 return syms.longType.constType(
241 new Long(longValue(l) ^ longValue(r)));
242 case lshl: case lshll:
243 return syms.longType.constType(
244 new Long(longValue(l) << intValue(r)));
245 case lshr: case lshrl:
246 return syms.longType.constType(
247 new Long(longValue(l) >> intValue(r)));
248 case lushr:
249 return syms.longType.constType(
250 new Long(longValue(l) >>> intValue(r)));
251 case lcmp:
252 if (longValue(l) < longValue(r))
253 return syms.intType.constType(minusOne);
254 else if (longValue(l) > longValue(r))
255 return syms.intType.constType(one);
256 else
257 return syms.intType.constType(zero);
258 case fadd:
259 return syms.floatType.constType(
260 new Float(floatValue(l) + floatValue(r)));
261 case fsub:
262 return syms.floatType.constType(
263 new Float(floatValue(l) - floatValue(r)));
264 case fmul:
265 return syms.floatType.constType(
266 new Float(floatValue(l) * floatValue(r)));
267 case fdiv:
268 return syms.floatType.constType(
269 new Float(floatValue(l) / floatValue(r)));
270 case fmod:
271 return syms.floatType.constType(
272 new Float(floatValue(l) % floatValue(r)));
273 case fcmpg: case fcmpl:
274 if (floatValue(l) < floatValue(r))
275 return syms.intType.constType(minusOne);
276 else if (floatValue(l) > floatValue(r))
277 return syms.intType.constType(one);
278 else if (floatValue(l) == floatValue(r))
279 return syms.intType.constType(zero);
280 else if (opcode == fcmpg)
281 return syms.intType.constType(one);
282 else
283 return syms.intType.constType(minusOne);
284 case dadd:
285 return syms.doubleType.constType(
286 new Double(doubleValue(l) + doubleValue(r)));
287 case dsub:
288 return syms.doubleType.constType(
289 new Double(doubleValue(l) - doubleValue(r)));
290 case dmul:
291 return syms.doubleType.constType(
292 new Double(doubleValue(l) * doubleValue(r)));
293 case ddiv:
294 return syms.doubleType.constType(
295 new Double(doubleValue(l) / doubleValue(r)));
296 case dmod:
297 return syms.doubleType.constType(
298 new Double(doubleValue(l) % doubleValue(r)));
299 case dcmpg: case dcmpl:
300 if (doubleValue(l) < doubleValue(r))
301 return syms.intType.constType(minusOne);
302 else if (doubleValue(l) > doubleValue(r))
303 return syms.intType.constType(one);
304 else if (doubleValue(l) == doubleValue(r))
305 return syms.intType.constType(zero);
306 else if (opcode == dcmpg)
307 return syms.intType.constType(one);
308 else
309 return syms.intType.constType(minusOne);
310 case if_acmpeq:
311 return syms.booleanType.constType(b2i(l.equals(r)));
312 case if_acmpne:
313 return syms.booleanType.constType(b2i(!l.equals(r)));
314 case string_add:
315 return syms.stringType.constType(
316 left.stringValue() + right.stringValue());
317 default:
318 return null;
319 }
320 }
321 } catch (ArithmeticException e) {
322 return null;
323 }
324 }
326 /** Coerce constant type to target type.
327 * @param etype The source type of the coercion,
328 * which is assumed to be a constant type compatible with
329 * ttype.
330 * @param ttype The target type of the coercion.
331 */
332 Type coerce(Type etype, Type ttype) {
333 // WAS if (etype.baseType() == ttype.baseType())
334 if (etype.tsym.type == ttype.tsym.type)
335 return etype;
336 if (etype.isNumeric()) {
337 Object n = etype.constValue();
338 switch (ttype.getTag()) {
339 case BYTE:
340 return syms.byteType.constType(0 + (byte)intValue(n));
341 case CHAR:
342 return syms.charType.constType(0 + (char)intValue(n));
343 case SHORT:
344 return syms.shortType.constType(0 + (short)intValue(n));
345 case INT:
346 return syms.intType.constType(intValue(n));
347 case LONG:
348 return syms.longType.constType(longValue(n));
349 case FLOAT:
350 return syms.floatType.constType(floatValue(n));
351 case DOUBLE:
352 return syms.doubleType.constType(doubleValue(n));
353 }
354 }
355 return ttype;
356 }
357 }