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src/share/classes/com/sun/tools/javac/jvm/Gen.java@9ca8d8713094
src/share/classes/com/sun/tools/javac/jvm/Gen.java
Thu, 12 Oct 2017 19:50:01 +0800
- author
- aoqi
- date
- Thu, 12 Oct 2017 19:50:01 +0800
- changeset 2702
- 9ca8d8713094
- parent 2657
- d42678403377
- parent 2525
- 2eb010b6cb22
- child 2893
- ca5783d9a597
- permissions
- -rw-r--r--
merge
1 /*
2 * Copyright (c) 1999, 2014, 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.jvm;
28 import java.util.*;
30 import com.sun.tools.javac.util.*;
31 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
32 import com.sun.tools.javac.util.List;
33 import com.sun.tools.javac.code.*;
34 import com.sun.tools.javac.code.Attribute.TypeCompound;
35 import com.sun.tools.javac.code.Symbol.VarSymbol;
36 import com.sun.tools.javac.comp.*;
37 import com.sun.tools.javac.tree.*;
39 import com.sun.tools.javac.code.Symbol.*;
40 import com.sun.tools.javac.code.Type.*;
41 import com.sun.tools.javac.jvm.Code.*;
42 import com.sun.tools.javac.jvm.Items.*;
43 import com.sun.tools.javac.tree.EndPosTable;
44 import com.sun.tools.javac.tree.JCTree.*;
46 import static com.sun.tools.javac.code.Flags.*;
47 import static com.sun.tools.javac.code.Kinds.*;
48 import static com.sun.tools.javac.code.TypeTag.*;
49 import static com.sun.tools.javac.jvm.ByteCodes.*;
50 import static com.sun.tools.javac.jvm.CRTFlags.*;
51 import static com.sun.tools.javac.main.Option.*;
52 import static com.sun.tools.javac.tree.JCTree.Tag.*;
54 /** This pass maps flat Java (i.e. without inner classes) to bytecodes.
55 *
56 * <p><b>This is NOT part of any supported API.
57 * If you write code that depends on this, you do so at your own risk.
58 * This code and its internal interfaces are subject to change or
59 * deletion without notice.</b>
60 */
61 public class Gen extends JCTree.Visitor {
62 protected static final Context.Key<Gen> genKey =
63 new Context.Key<Gen>();
65 private final Log log;
66 private final Symtab syms;
67 private final Check chk;
68 private final Resolve rs;
69 private final TreeMaker make;
70 private final Names names;
71 private final Target target;
72 private final Type stringBufferType;
73 private final Map<Type,Symbol> stringBufferAppend;
74 private Name accessDollar;
75 private final Types types;
76 private final Lower lower;
77 private final Flow flow;
79 /** Switch: GJ mode?
80 */
81 private final boolean allowGenerics;
83 /** Set when Miranda method stubs are to be generated. */
84 private final boolean generateIproxies;
86 /** Format of stackmap tables to be generated. */
87 private final Code.StackMapFormat stackMap;
89 /** A type that serves as the expected type for all method expressions.
90 */
91 private final Type methodType;
93 public static Gen instance(Context context) {
94 Gen instance = context.get(genKey);
95 if (instance == null)
96 instance = new Gen(context);
97 return instance;
98 }
100 /** Constant pool, reset by genClass.
101 */
102 private Pool pool;
104 /** LVTRanges info.
105 */
106 private LVTRanges lvtRanges;
108 private final boolean typeAnnoAsserts;
110 protected Gen(Context context) {
111 context.put(genKey, this);
113 names = Names.instance(context);
114 log = Log.instance(context);
115 syms = Symtab.instance(context);
116 chk = Check.instance(context);
117 rs = Resolve.instance(context);
118 make = TreeMaker.instance(context);
119 target = Target.instance(context);
120 types = Types.instance(context);
121 methodType = new MethodType(null, null, null, syms.methodClass);
122 allowGenerics = Source.instance(context).allowGenerics();
123 stringBufferType = target.useStringBuilder()
124 ? syms.stringBuilderType
125 : syms.stringBufferType;
126 stringBufferAppend = new HashMap<Type,Symbol>();
127 accessDollar = names.
128 fromString("access" + target.syntheticNameChar());
129 flow = Flow.instance(context);
130 lower = Lower.instance(context);
132 Options options = Options.instance(context);
133 lineDebugInfo =
134 options.isUnset(G_CUSTOM) ||
135 options.isSet(G_CUSTOM, "lines");
136 varDebugInfo =
137 options.isUnset(G_CUSTOM)
138 ? options.isSet(G)
139 : options.isSet(G_CUSTOM, "vars");
140 if (varDebugInfo) {
141 lvtRanges = LVTRanges.instance(context);
142 }
143 genCrt = options.isSet(XJCOV);
144 debugCode = options.isSet("debugcode");
145 allowInvokedynamic = target.hasInvokedynamic() || options.isSet("invokedynamic");
146 pool = new Pool(types);
147 typeAnnoAsserts = options.isSet("TypeAnnotationAsserts");
149 generateIproxies =
150 target.requiresIproxy() ||
151 options.isSet("miranda");
153 if (target.generateStackMapTable()) {
154 // ignore cldc because we cannot have both stackmap formats
155 this.stackMap = StackMapFormat.JSR202;
156 } else {
157 if (target.generateCLDCStackmap()) {
158 this.stackMap = StackMapFormat.CLDC;
159 } else {
160 this.stackMap = StackMapFormat.NONE;
161 }
162 }
164 // by default, avoid jsr's for simple finalizers
165 int setjsrlimit = 50;
166 String jsrlimitString = options.get("jsrlimit");
167 if (jsrlimitString != null) {
168 try {
169 setjsrlimit = Integer.parseInt(jsrlimitString);
170 } catch (NumberFormatException ex) {
171 // ignore ill-formed numbers for jsrlimit
172 }
173 }
174 this.jsrlimit = setjsrlimit;
175 this.useJsrLocally = false; // reset in visitTry
176 }
178 /** Switches
179 */
180 private final boolean lineDebugInfo;
181 private final boolean varDebugInfo;
182 private final boolean genCrt;
183 private final boolean debugCode;
184 private final boolean allowInvokedynamic;
186 /** Default limit of (approximate) size of finalizer to inline.
187 * Zero means always use jsr. 100 or greater means never use
188 * jsr.
189 */
190 private final int jsrlimit;
192 /** True if jsr is used.
193 */
194 private boolean useJsrLocally;
196 /** Code buffer, set by genMethod.
197 */
198 private Code code;
200 /** Items structure, set by genMethod.
201 */
202 private Items items;
204 /** Environment for symbol lookup, set by genClass
205 */
206 private Env<AttrContext> attrEnv;
208 /** The top level tree.
209 */
210 private JCCompilationUnit toplevel;
212 /** The number of code-gen errors in this class.
213 */
214 private int nerrs = 0;
216 /** An object containing mappings of syntax trees to their
217 * ending source positions.
218 */
219 EndPosTable endPosTable;
221 /** Generate code to load an integer constant.
222 * @param n The integer to be loaded.
223 */
224 void loadIntConst(int n) {
225 items.makeImmediateItem(syms.intType, n).load();
226 }
228 /** The opcode that loads a zero constant of a given type code.
229 * @param tc The given type code (@see ByteCode).
230 */
231 public static int zero(int tc) {
232 switch(tc) {
233 case INTcode: case BYTEcode: case SHORTcode: case CHARcode:
234 return iconst_0;
235 case LONGcode:
236 return lconst_0;
237 case FLOATcode:
238 return fconst_0;
239 case DOUBLEcode:
240 return dconst_0;
241 default:
242 throw new AssertionError("zero");
243 }
244 }
246 /** The opcode that loads a one constant of a given type code.
247 * @param tc The given type code (@see ByteCode).
248 */
249 public static int one(int tc) {
250 return zero(tc) + 1;
251 }
253 /** Generate code to load -1 of the given type code (either int or long).
254 * @param tc The given type code (@see ByteCode).
255 */
256 void emitMinusOne(int tc) {
257 if (tc == LONGcode) {
258 items.makeImmediateItem(syms.longType, new Long(-1)).load();
259 } else {
260 code.emitop0(iconst_m1);
261 }
262 }
264 /** Construct a symbol to reflect the qualifying type that should
265 * appear in the byte code as per JLS 13.1.
266 *
267 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except
268 * for those cases where we need to work around VM bugs).
269 *
270 * For {@literal target <= 1.1}: If qualified variable or method is defined in a
271 * non-accessible class, clone it with the qualifier class as owner.
272 *
273 * @param sym The accessed symbol
274 * @param site The qualifier's type.
275 */
276 Symbol binaryQualifier(Symbol sym, Type site) {
278 if (site.hasTag(ARRAY)) {
279 if (sym == syms.lengthVar ||
280 sym.owner != syms.arrayClass)
281 return sym;
282 // array clone can be qualified by the array type in later targets
283 Symbol qualifier = target.arrayBinaryCompatibility()
284 ? new ClassSymbol(Flags.PUBLIC, site.tsym.name,
285 site, syms.noSymbol)
286 : syms.objectType.tsym;
287 return sym.clone(qualifier);
288 }
290 if (sym.owner == site.tsym ||
291 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) {
292 return sym;
293 }
294 if (!target.obeyBinaryCompatibility())
295 return rs.isAccessible(attrEnv, (TypeSymbol)sym.owner)
296 ? sym
297 : sym.clone(site.tsym);
299 if (!target.interfaceFieldsBinaryCompatibility()) {
300 if ((sym.owner.flags() & INTERFACE) != 0 && sym.kind == VAR)
301 return sym;
302 }
304 // leave alone methods inherited from Object
305 // JLS 13.1.
306 if (sym.owner == syms.objectType.tsym)
307 return sym;
309 if (!target.interfaceObjectOverridesBinaryCompatibility()) {
310 if ((sym.owner.flags() & INTERFACE) != 0 &&
311 syms.objectType.tsym.members().lookup(sym.name).scope != null)
312 return sym;
313 }
315 return sym.clone(site.tsym);
316 }
318 /** Insert a reference to given type in the constant pool,
319 * checking for an array with too many dimensions;
320 * return the reference's index.
321 * @param type The type for which a reference is inserted.
322 */
323 int makeRef(DiagnosticPosition pos, Type type) {
324 checkDimension(pos, type);
325 if (type.isAnnotated()) {
326 // Treat annotated types separately - we don't want
327 // to collapse all of them - at least for annotated
328 // exceptions.
329 // TODO: review this.
330 return pool.put((Object)type);
331 } else {
332 return pool.put(type.hasTag(CLASS) ? (Object)type.tsym : (Object)type);
333 }
334 }
336 /** Check if the given type is an array with too many dimensions.
337 */
338 private void checkDimension(DiagnosticPosition pos, Type t) {
339 switch (t.getTag()) {
340 case METHOD:
341 checkDimension(pos, t.getReturnType());
342 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail)
343 checkDimension(pos, args.head);
344 break;
345 case ARRAY:
346 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) {
347 log.error(pos, "limit.dimensions");
348 nerrs++;
349 }
350 break;
351 default:
352 break;
353 }
354 }
356 /** Create a tempory variable.
357 * @param type The variable's type.
358 */
359 LocalItem makeTemp(Type type) {
360 VarSymbol v = new VarSymbol(Flags.SYNTHETIC,
361 names.empty,
362 type,
363 env.enclMethod.sym);
364 code.newLocal(v);
365 return items.makeLocalItem(v);
366 }
368 /** Generate code to call a non-private method or constructor.
369 * @param pos Position to be used for error reporting.
370 * @param site The type of which the method is a member.
371 * @param name The method's name.
372 * @param argtypes The method's argument types.
373 * @param isStatic A flag that indicates whether we call a
374 * static or instance method.
375 */
376 void callMethod(DiagnosticPosition pos,
377 Type site, Name name, List<Type> argtypes,
378 boolean isStatic) {
379 Symbol msym = rs.
380 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null);
381 if (isStatic) items.makeStaticItem(msym).invoke();
382 else items.makeMemberItem(msym, name == names.init).invoke();
383 }
385 /** Is the given method definition an access method
386 * resulting from a qualified super? This is signified by an odd
387 * access code.
388 */
389 private boolean isAccessSuper(JCMethodDecl enclMethod) {
390 return
391 (enclMethod.mods.flags & SYNTHETIC) != 0 &&
392 isOddAccessName(enclMethod.name);
393 }
395 /** Does given name start with "access$" and end in an odd digit?
396 */
397 private boolean isOddAccessName(Name name) {
398 return
399 name.startsWith(accessDollar) &&
400 (name.getByteAt(name.getByteLength() - 1) & 1) == 1;
401 }
403 /* ************************************************************************
404 * Non-local exits
405 *************************************************************************/
407 /** Generate code to invoke the finalizer associated with given
408 * environment.
409 * Any calls to finalizers are appended to the environments `cont' chain.
410 * Mark beginning of gap in catch all range for finalizer.
411 */
412 void genFinalizer(Env<GenContext> env) {
413 if (code.isAlive() && env.info.finalize != null)
414 env.info.finalize.gen();
415 }
417 /** Generate code to call all finalizers of structures aborted by
418 * a non-local
419 * exit. Return target environment of the non-local exit.
420 * @param target The tree representing the structure that's aborted
421 * @param env The environment current at the non-local exit.
422 */
423 Env<GenContext> unwind(JCTree target, Env<GenContext> env) {
424 Env<GenContext> env1 = env;
425 while (true) {
426 genFinalizer(env1);
427 if (env1.tree == target) break;
428 env1 = env1.next;
429 }
430 return env1;
431 }
433 /** Mark end of gap in catch-all range for finalizer.
434 * @param env the environment which might contain the finalizer
435 * (if it does, env.info.gaps != null).
436 */
437 void endFinalizerGap(Env<GenContext> env) {
438 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1)
439 env.info.gaps.append(code.curCP());
440 }
442 /** Mark end of all gaps in catch-all ranges for finalizers of environments
443 * lying between, and including to two environments.
444 * @param from the most deeply nested environment to mark
445 * @param to the least deeply nested environment to mark
446 */
447 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) {
448 Env<GenContext> last = null;
449 while (last != to) {
450 endFinalizerGap(from);
451 last = from;
452 from = from.next;
453 }
454 }
456 /** Do any of the structures aborted by a non-local exit have
457 * finalizers that require an empty stack?
458 * @param target The tree representing the structure that's aborted
459 * @param env The environment current at the non-local exit.
460 */
461 boolean hasFinally(JCTree target, Env<GenContext> env) {
462 while (env.tree != target) {
463 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer())
464 return true;
465 env = env.next;
466 }
467 return false;
468 }
470 /* ************************************************************************
471 * Normalizing class-members.
472 *************************************************************************/
474 /** Distribute member initializer code into constructors and {@code <clinit>}
475 * method.
476 * @param defs The list of class member declarations.
477 * @param c The enclosing class.
478 */
479 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) {
480 ListBuffer<JCStatement> initCode = new ListBuffer<JCStatement>();
481 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<Attribute.TypeCompound>();
482 ListBuffer<JCStatement> clinitCode = new ListBuffer<JCStatement>();
483 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<Attribute.TypeCompound>();
484 ListBuffer<JCTree> methodDefs = new ListBuffer<JCTree>();
485 // Sort definitions into three listbuffers:
486 // - initCode for instance initializers
487 // - clinitCode for class initializers
488 // - methodDefs for method definitions
489 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
490 JCTree def = l.head;
491 switch (def.getTag()) {
492 case BLOCK:
493 JCBlock block = (JCBlock)def;
494 if ((block.flags & STATIC) != 0)
495 clinitCode.append(block);
496 else
497 initCode.append(block);
498 break;
499 case METHODDEF:
500 methodDefs.append(def);
501 break;
502 case VARDEF:
503 JCVariableDecl vdef = (JCVariableDecl) def;
504 VarSymbol sym = vdef.sym;
505 checkDimension(vdef.pos(), sym.type);
506 if (vdef.init != null) {
507 if ((sym.flags() & STATIC) == 0) {
508 // Always initialize instance variables.
509 JCStatement init = make.at(vdef.pos()).
510 Assignment(sym, vdef.init);
511 initCode.append(init);
512 endPosTable.replaceTree(vdef, init);
513 initTAs.addAll(getAndRemoveNonFieldTAs(sym));
514 } else if (sym.getConstValue() == null) {
515 // Initialize class (static) variables only if
516 // they are not compile-time constants.
517 JCStatement init = make.at(vdef.pos).
518 Assignment(sym, vdef.init);
519 clinitCode.append(init);
520 endPosTable.replaceTree(vdef, init);
521 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym));
522 } else {
523 checkStringConstant(vdef.init.pos(), sym.getConstValue());
524 }
525 }
526 break;
527 default:
528 Assert.error();
529 }
530 }
531 // Insert any instance initializers into all constructors.
532 if (initCode.length() != 0) {
533 List<JCStatement> inits = initCode.toList();
534 initTAs.addAll(c.getInitTypeAttributes());
535 List<Attribute.TypeCompound> initTAlist = initTAs.toList();
536 for (JCTree t : methodDefs) {
537 normalizeMethod((JCMethodDecl)t, inits, initTAlist);
538 }
539 }
540 // If there are class initializers, create a <clinit> method
541 // that contains them as its body.
542 if (clinitCode.length() != 0) {
543 MethodSymbol clinit = new MethodSymbol(
544 STATIC | (c.flags() & STRICTFP),
545 names.clinit,
546 new MethodType(
547 List.<Type>nil(), syms.voidType,
548 List.<Type>nil(), syms.methodClass),
549 c);
550 c.members().enter(clinit);
551 List<JCStatement> clinitStats = clinitCode.toList();
552 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
553 block.endpos = TreeInfo.endPos(clinitStats.last());
554 methodDefs.append(make.MethodDef(clinit, block));
556 if (!clinitTAs.isEmpty())
557 clinit.appendUniqueTypeAttributes(clinitTAs.toList());
558 if (!c.getClassInitTypeAttributes().isEmpty())
559 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes());
560 }
561 // Return all method definitions.
562 return methodDefs.toList();
563 }
565 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) {
566 List<TypeCompound> tas = sym.getRawTypeAttributes();
567 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<Attribute.TypeCompound>();
568 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<Attribute.TypeCompound>();
569 for (TypeCompound ta : tas) {
570 if (ta.getPosition().type == TargetType.FIELD) {
571 fieldTAs.add(ta);
572 } else {
573 if (typeAnnoAsserts) {
574 Assert.error("Type annotation does not have a valid positior");
575 }
577 nonfieldTAs.add(ta);
578 }
579 }
580 sym.setTypeAttributes(fieldTAs.toList());
581 return nonfieldTAs.toList();
582 }
584 /** Check a constant value and report if it is a string that is
585 * too large.
586 */
587 private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
588 if (nerrs != 0 || // only complain about a long string once
589 constValue == null ||
590 !(constValue instanceof String) ||
591 ((String)constValue).length() < Pool.MAX_STRING_LENGTH)
592 return;
593 log.error(pos, "limit.string");
594 nerrs++;
595 }
597 /** Insert instance initializer code into initial constructor.
598 * @param md The tree potentially representing a
599 * constructor's definition.
600 * @param initCode The list of instance initializer statements.
601 * @param initTAs Type annotations from the initializer expression.
602 */
603 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<TypeCompound> initTAs) {
604 if (md.name == names.init && TreeInfo.isInitialConstructor(md)) {
605 // We are seeing a constructor that does not call another
606 // constructor of the same class.
607 List<JCStatement> stats = md.body.stats;
608 ListBuffer<JCStatement> newstats = new ListBuffer<JCStatement>();
610 if (stats.nonEmpty()) {
611 // Copy initializers of synthetic variables generated in
612 // the translation of inner classes.
613 while (TreeInfo.isSyntheticInit(stats.head)) {
614 newstats.append(stats.head);
615 stats = stats.tail;
616 }
617 // Copy superclass constructor call
618 newstats.append(stats.head);
619 stats = stats.tail;
620 // Copy remaining synthetic initializers.
621 while (stats.nonEmpty() &&
622 TreeInfo.isSyntheticInit(stats.head)) {
623 newstats.append(stats.head);
624 stats = stats.tail;
625 }
626 // Now insert the initializer code.
627 newstats.appendList(initCode);
628 // And copy all remaining statements.
629 while (stats.nonEmpty()) {
630 newstats.append(stats.head);
631 stats = stats.tail;
632 }
633 }
634 md.body.stats = newstats.toList();
635 if (md.body.endpos == Position.NOPOS)
636 md.body.endpos = TreeInfo.endPos(md.body.stats.last());
638 md.sym.appendUniqueTypeAttributes(initTAs);
639 }
640 }
642 /* ********************************************************************
643 * Adding miranda methods
644 *********************************************************************/
646 /** Add abstract methods for all methods defined in one of
647 * the interfaces of a given class,
648 * provided they are not already implemented in the class.
649 *
650 * @param c The class whose interfaces are searched for methods
651 * for which Miranda methods should be added.
652 */
653 void implementInterfaceMethods(ClassSymbol c) {
654 implementInterfaceMethods(c, c);
655 }
657 /** Add abstract methods for all methods defined in one of
658 * the interfaces of a given class,
659 * provided they are not already implemented in the class.
660 *
661 * @param c The class whose interfaces are searched for methods
662 * for which Miranda methods should be added.
663 * @param site The class in which a definition may be needed.
664 */
665 void implementInterfaceMethods(ClassSymbol c, ClassSymbol site) {
666 for (List<Type> l = types.interfaces(c.type); l.nonEmpty(); l = l.tail) {
667 ClassSymbol i = (ClassSymbol)l.head.tsym;
668 for (Scope.Entry e = i.members().elems;
669 e != null;
670 e = e.sibling)
671 {
672 if (e.sym.kind == MTH && (e.sym.flags() & STATIC) == 0)
673 {
674 MethodSymbol absMeth = (MethodSymbol)e.sym;
675 MethodSymbol implMeth = absMeth.binaryImplementation(site, types);
676 if (implMeth == null)
677 addAbstractMethod(site, absMeth);
678 else if ((implMeth.flags() & IPROXY) != 0)
679 adjustAbstractMethod(site, implMeth, absMeth);
680 }
681 }
682 implementInterfaceMethods(i, site);
683 }
684 }
686 /** Add an abstract methods to a class
687 * which implicitly implements a method defined in some interface
688 * implemented by the class. These methods are called "Miranda methods".
689 * Enter the newly created method into its enclosing class scope.
690 * Note that it is not entered into the class tree, as the emitter
691 * doesn't need to see it there to emit an abstract method.
692 *
693 * @param c The class to which the Miranda method is added.
694 * @param m The interface method symbol for which a Miranda method
695 * is added.
696 */
697 private void addAbstractMethod(ClassSymbol c,
698 MethodSymbol m) {
699 MethodSymbol absMeth = new MethodSymbol(
700 m.flags() | IPROXY | SYNTHETIC, m.name,
701 m.type, // was c.type.memberType(m), but now only !generics supported
702 c);
703 c.members().enter(absMeth); // add to symbol table
704 }
706 private void adjustAbstractMethod(ClassSymbol c,
707 MethodSymbol pm,
708 MethodSymbol im) {
709 MethodType pmt = (MethodType)pm.type;
710 Type imt = types.memberType(c.type, im);
711 pmt.thrown = chk.intersect(pmt.getThrownTypes(), imt.getThrownTypes());
712 }
714 /* ************************************************************************
715 * Traversal methods
716 *************************************************************************/
718 /** Visitor argument: The current environment.
719 */
720 Env<GenContext> env;
722 /** Visitor argument: The expected type (prototype).
723 */
724 Type pt;
726 /** Visitor result: The item representing the computed value.
727 */
728 Item result;
730 /** Visitor method: generate code for a definition, catching and reporting
731 * any completion failures.
732 * @param tree The definition to be visited.
733 * @param env The environment current at the definition.
734 */
735 public void genDef(JCTree tree, Env<GenContext> env) {
736 Env<GenContext> prevEnv = this.env;
737 try {
738 this.env = env;
739 tree.accept(this);
740 } catch (CompletionFailure ex) {
741 chk.completionError(tree.pos(), ex);
742 } finally {
743 this.env = prevEnv;
744 }
745 }
747 /** Derived visitor method: check whether CharacterRangeTable
748 * should be emitted, if so, put a new entry into CRTable
749 * and call method to generate bytecode.
750 * If not, just call method to generate bytecode.
751 * @see #genStat(JCTree, Env)
752 *
753 * @param tree The tree to be visited.
754 * @param env The environment to use.
755 * @param crtFlags The CharacterRangeTable flags
756 * indicating type of the entry.
757 */
758 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
759 if (!genCrt) {
760 genStat(tree, env);
761 return;
762 }
763 int startpc = code.curCP();
764 genStat(tree, env);
765 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK;
766 code.crt.put(tree, crtFlags, startpc, code.curCP());
767 }
769 /** Derived visitor method: generate code for a statement.
770 */
771 public void genStat(JCTree tree, Env<GenContext> env) {
772 if (code.isAlive()) {
773 code.statBegin(tree.pos);
774 genDef(tree, env);
775 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) {
776 // variables whose declarations are in a switch
777 // can be used even if the decl is unreachable.
778 code.newLocal(((JCVariableDecl) tree).sym);
779 }
780 }
782 /** Derived visitor method: check whether CharacterRangeTable
783 * should be emitted, if so, put a new entry into CRTable
784 * and call method to generate bytecode.
785 * If not, just call method to generate bytecode.
786 * @see #genStats(List, Env)
787 *
788 * @param trees The list of trees to be visited.
789 * @param env The environment to use.
790 * @param crtFlags The CharacterRangeTable flags
791 * indicating type of the entry.
792 */
793 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
794 if (!genCrt) {
795 genStats(trees, env);
796 return;
797 }
798 if (trees.length() == 1) { // mark one statement with the flags
799 genStat(trees.head, env, crtFlags | CRT_STATEMENT);
800 } else {
801 int startpc = code.curCP();
802 genStats(trees, env);
803 code.crt.put(trees, crtFlags, startpc, code.curCP());
804 }
805 }
807 /** Derived visitor method: generate code for a list of statements.
808 */
809 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) {
810 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
811 genStat(l.head, env, CRT_STATEMENT);
812 }
814 /** Derived visitor method: check whether CharacterRangeTable
815 * should be emitted, if so, put a new entry into CRTable
816 * and call method to generate bytecode.
817 * If not, just call method to generate bytecode.
818 * @see #genCond(JCTree,boolean)
819 *
820 * @param tree The tree to be visited.
821 * @param crtFlags The CharacterRangeTable flags
822 * indicating type of the entry.
823 */
824 public CondItem genCond(JCTree tree, int crtFlags) {
825 if (!genCrt) return genCond(tree, false);
826 int startpc = code.curCP();
827 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
828 code.crt.put(tree, crtFlags, startpc, code.curCP());
829 return item;
830 }
832 /** Derived visitor method: generate code for a boolean
833 * expression in a control-flow context.
834 * @param _tree The expression to be visited.
835 * @param markBranches The flag to indicate that the condition is
836 * a flow controller so produced conditions
837 * should contain a proper tree to generate
838 * CharacterRangeTable branches for them.
839 */
840 public CondItem genCond(JCTree _tree, boolean markBranches) {
841 JCTree inner_tree = TreeInfo.skipParens(_tree);
842 if (inner_tree.hasTag(CONDEXPR)) {
843 JCConditional tree = (JCConditional)inner_tree;
844 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
845 if (cond.isTrue()) {
846 code.resolve(cond.trueJumps);
847 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
848 if (markBranches) result.tree = tree.truepart;
849 return result;
850 }
851 if (cond.isFalse()) {
852 code.resolve(cond.falseJumps);
853 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
854 if (markBranches) result.tree = tree.falsepart;
855 return result;
856 }
857 Chain secondJumps = cond.jumpFalse();
858 code.resolve(cond.trueJumps);
859 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
860 if (markBranches) first.tree = tree.truepart;
861 Chain falseJumps = first.jumpFalse();
862 code.resolve(first.trueJumps);
863 Chain trueJumps = code.branch(goto_);
864 code.resolve(secondJumps);
865 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
866 CondItem result = items.makeCondItem(second.opcode,
867 Code.mergeChains(trueJumps, second.trueJumps),
868 Code.mergeChains(falseJumps, second.falseJumps));
869 if (markBranches) result.tree = tree.falsepart;
870 return result;
871 } else {
872 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
873 if (markBranches) result.tree = _tree;
874 return result;
875 }
876 }
878 /** Visitor class for expressions which might be constant expressions.
879 * This class is a subset of TreeScanner. Intended to visit trees pruned by
880 * Lower as long as constant expressions looking for references to any
881 * ClassSymbol. Any such reference will be added to the constant pool so
882 * automated tools can detect class dependencies better.
883 */
884 class ClassReferenceVisitor extends JCTree.Visitor {
886 @Override
887 public void visitTree(JCTree tree) {}
889 @Override
890 public void visitBinary(JCBinary tree) {
891 tree.lhs.accept(this);
892 tree.rhs.accept(this);
893 }
895 @Override
896 public void visitSelect(JCFieldAccess tree) {
897 if (tree.selected.type.hasTag(CLASS)) {
898 makeRef(tree.selected.pos(), tree.selected.type);
899 }
900 }
902 @Override
903 public void visitIdent(JCIdent tree) {
904 if (tree.sym.owner instanceof ClassSymbol) {
905 pool.put(tree.sym.owner);
906 }
907 }
909 @Override
910 public void visitConditional(JCConditional tree) {
911 tree.cond.accept(this);
912 tree.truepart.accept(this);
913 tree.falsepart.accept(this);
914 }
916 @Override
917 public void visitUnary(JCUnary tree) {
918 tree.arg.accept(this);
919 }
921 @Override
922 public void visitParens(JCParens tree) {
923 tree.expr.accept(this);
924 }
926 @Override
927 public void visitTypeCast(JCTypeCast tree) {
928 tree.expr.accept(this);
929 }
930 }
932 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor();
934 /** Visitor method: generate code for an expression, catching and reporting
935 * any completion failures.
936 * @param tree The expression to be visited.
937 * @param pt The expression's expected type (proto-type).
938 */
939 public Item genExpr(JCTree tree, Type pt) {
940 Type prevPt = this.pt;
941 try {
942 if (tree.type.constValue() != null) {
943 // Short circuit any expressions which are constants
944 tree.accept(classReferenceVisitor);
945 checkStringConstant(tree.pos(), tree.type.constValue());
946 result = items.makeImmediateItem(tree.type, tree.type.constValue());
947 } else {
948 this.pt = pt;
949 tree.accept(this);
950 }
951 return result.coerce(pt);
952 } catch (CompletionFailure ex) {
953 chk.completionError(tree.pos(), ex);
954 code.state.stacksize = 1;
955 return items.makeStackItem(pt);
956 } finally {
957 this.pt = prevPt;
958 }
959 }
961 /** Derived visitor method: generate code for a list of method arguments.
962 * @param trees The argument expressions to be visited.
963 * @param pts The expression's expected types (i.e. the formal parameter
964 * types of the invoked method).
965 */
966 public void genArgs(List<JCExpression> trees, List<Type> pts) {
967 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
968 genExpr(l.head, pts.head).load();
969 pts = pts.tail;
970 }
971 // require lists be of same length
972 Assert.check(pts.isEmpty());
973 }
975 /* ************************************************************************
976 * Visitor methods for statements and definitions
977 *************************************************************************/
979 /** Thrown when the byte code size exceeds limit.
980 */
981 public static class CodeSizeOverflow extends RuntimeException {
982 private static final long serialVersionUID = 0;
983 public CodeSizeOverflow() {}
984 }
986 public void visitMethodDef(JCMethodDecl tree) {
987 // Create a new local environment that points pack at method
988 // definition.
989 Env<GenContext> localEnv = env.dup(tree);
990 localEnv.enclMethod = tree;
991 // The expected type of every return statement in this method
992 // is the method's return type.
993 this.pt = tree.sym.erasure(types).getReturnType();
995 checkDimension(tree.pos(), tree.sym.erasure(types));
996 genMethod(tree, localEnv, false);
997 }
998 //where
999 /** Generate code for a method.
1000 * @param tree The tree representing the method definition.
1001 * @param env The environment current for the method body.
1002 * @param fatcode A flag that indicates whether all jumps are
1003 * within 32K. We first invoke this method under
1004 * the assumption that fatcode == false, i.e. all
1005 * jumps are within 32K. If this fails, fatcode
1006 * is set to true and we try again.
1007 */
1008 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1009 MethodSymbol meth = tree.sym;
1010 int extras = 0;
1011 // Count up extra parameters
1012 if (meth.isConstructor()) {
1013 extras++;
1014 if (meth.enclClass().isInner() &&
1015 !meth.enclClass().isStatic()) {
1016 extras++;
1017 }
1018 } else if ((tree.mods.flags & STATIC) == 0) {
1019 extras++;
1020 }
1021 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
1022 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
1023 ClassFile.MAX_PARAMETERS) {
1024 log.error(tree.pos(), "limit.parameters");
1025 nerrs++;
1026 }
1028 else if (tree.body != null) {
1029 // Create a new code structure and initialize it.
1030 int startpcCrt = initCode(tree, env, fatcode);
1032 try {
1033 genStat(tree.body, env);
1034 } catch (CodeSizeOverflow e) {
1035 // Failed due to code limit, try again with jsr/ret
1036 startpcCrt = initCode(tree, env, fatcode);
1037 genStat(tree.body, env);
1038 }
1040 if (code.state.stacksize != 0) {
1041 log.error(tree.body.pos(), "stack.sim.error", tree);
1042 throw new AssertionError();
1043 }
1045 // If last statement could complete normally, insert a
1046 // return at the end.
1047 if (code.isAlive()) {
1048 code.statBegin(TreeInfo.endPos(tree.body));
1049 if (env.enclMethod == null ||
1050 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
1051 code.emitop0(return_);
1052 } else {
1053 // sometime dead code seems alive (4415991);
1054 // generate a small loop instead
1055 int startpc = code.entryPoint();
1056 CondItem c = items.makeCondItem(goto_);
1057 code.resolve(c.jumpTrue(), startpc);
1058 }
1059 }
1060 if (genCrt)
1061 code.crt.put(tree.body,
1062 CRT_BLOCK,
1063 startpcCrt,
1064 code.curCP());
1066 code.endScopes(0);
1068 // If we exceeded limits, panic
1069 if (code.checkLimits(tree.pos(), log)) {
1070 nerrs++;
1071 return;
1072 }
1074 // If we generated short code but got a long jump, do it again
1075 // with fatCode = true.
1076 if (!fatcode && code.fatcode) genMethod(tree, env, true);
1078 // Clean up
1079 if(stackMap == StackMapFormat.JSR202) {
1080 code.lastFrame = null;
1081 code.frameBeforeLast = null;
1082 }
1084 // Compress exception table
1085 code.compressCatchTable();
1087 // Fill in type annotation positions for exception parameters
1088 code.fillExceptionParameterPositions();
1089 }
1090 }
1092 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1093 MethodSymbol meth = tree.sym;
1095 // Create a new code structure.
1096 meth.code = code = new Code(meth,
1097 fatcode,
1098 lineDebugInfo ? toplevel.lineMap : null,
1099 varDebugInfo,
1100 stackMap,
1101 debugCode,
1102 genCrt ? new CRTable(tree, env.toplevel.endPositions)
1103 : null,
1104 syms,
1105 types,
1106 pool,
1107 varDebugInfo ? lvtRanges : null);
1108 items = new Items(pool, code, syms, types);
1109 if (code.debugCode) {
1110 System.err.println(meth + " for body " + tree);
1111 }
1113 // If method is not static, create a new local variable address
1114 // for `this'.
1115 if ((tree.mods.flags & STATIC) == 0) {
1116 Type selfType = meth.owner.type;
1117 if (meth.isConstructor() && selfType != syms.objectType)
1118 selfType = UninitializedType.uninitializedThis(selfType);
1119 code.setDefined(
1120 code.newLocal(
1121 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1122 }
1124 // Mark all parameters as defined from the beginning of
1125 // the method.
1126 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1127 checkDimension(l.head.pos(), l.head.sym.type);
1128 code.setDefined(code.newLocal(l.head.sym));
1129 }
1131 // Get ready to generate code for method body.
1132 int startpcCrt = genCrt ? code.curCP() : 0;
1133 code.entryPoint();
1135 // Suppress initial stackmap
1136 code.pendingStackMap = false;
1138 return startpcCrt;
1139 }
1141 public void visitVarDef(JCVariableDecl tree) {
1142 VarSymbol v = tree.sym;
1143 code.newLocal(v);
1144 if (tree.init != null) {
1145 checkStringConstant(tree.init.pos(), v.getConstValue());
1146 if (v.getConstValue() == null || varDebugInfo) {
1147 genExpr(tree.init, v.erasure(types)).load();
1148 items.makeLocalItem(v).store();
1149 }
1150 }
1151 checkDimension(tree.pos(), v.type);
1152 }
1154 public void visitSkip(JCSkip tree) {
1155 }
1157 public void visitBlock(JCBlock tree) {
1158 int limit = code.nextreg;
1159 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1160 genStats(tree.stats, localEnv);
1161 // End the scope of all block-local variables in variable info.
1162 if (!env.tree.hasTag(METHODDEF)) {
1163 code.statBegin(tree.endpos);
1164 code.endScopes(limit);
1165 code.pendingStatPos = Position.NOPOS;
1166 }
1167 }
1169 public void visitDoLoop(JCDoWhileLoop tree) {
1170 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), false);
1171 }
1173 public void visitWhileLoop(JCWhileLoop tree) {
1174 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), true);
1175 }
1177 public void visitForLoop(JCForLoop tree) {
1178 int limit = code.nextreg;
1179 genStats(tree.init, env);
1180 genLoop(tree, tree.body, tree.cond, tree.step, true);
1181 code.endScopes(limit);
1182 }
1183 //where
1184 /** Generate code for a loop.
1185 * @param loop The tree representing the loop.
1186 * @param body The loop's body.
1187 * @param cond The loop's controling condition.
1188 * @param step "Step" statements to be inserted at end of
1189 * each iteration.
1190 * @param testFirst True if the loop test belongs before the body.
1191 */
1192 private void genLoop(JCStatement loop,
1193 JCStatement body,
1194 JCExpression cond,
1195 List<JCExpressionStatement> step,
1196 boolean testFirst) {
1197 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1198 int startpc = code.entryPoint();
1199 if (testFirst) { //while or for loop
1200 CondItem c;
1201 if (cond != null) {
1202 code.statBegin(cond.pos);
1203 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1204 } else {
1205 c = items.makeCondItem(goto_);
1206 }
1207 Chain loopDone = c.jumpFalse();
1208 code.resolve(c.trueJumps);
1209 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1210 if (varDebugInfo) {
1211 checkLoopLocalVarRangeEnding(loop, body,
1212 LoopLocalVarRangeEndingPoint.BEFORE_STEPS);
1213 }
1214 code.resolve(loopEnv.info.cont);
1215 genStats(step, loopEnv);
1216 if (varDebugInfo) {
1217 checkLoopLocalVarRangeEnding(loop, body,
1218 LoopLocalVarRangeEndingPoint.AFTER_STEPS);
1219 }
1220 code.resolve(code.branch(goto_), startpc);
1221 code.resolve(loopDone);
1222 } else {
1223 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1224 if (varDebugInfo) {
1225 checkLoopLocalVarRangeEnding(loop, body,
1226 LoopLocalVarRangeEndingPoint.BEFORE_STEPS);
1227 }
1228 code.resolve(loopEnv.info.cont);
1229 genStats(step, loopEnv);
1230 if (varDebugInfo) {
1231 checkLoopLocalVarRangeEnding(loop, body,
1232 LoopLocalVarRangeEndingPoint.AFTER_STEPS);
1233 }
1234 CondItem c;
1235 if (cond != null) {
1236 code.statBegin(cond.pos);
1237 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1238 } else {
1239 c = items.makeCondItem(goto_);
1240 }
1241 code.resolve(c.jumpTrue(), startpc);
1242 code.resolve(c.falseJumps);
1243 }
1244 code.resolve(loopEnv.info.exit);
1245 if (loopEnv.info.exit != null) {
1246 loopEnv.info.exit.state.defined.excludeFrom(code.nextreg);
1247 }
1248 }
1250 private enum LoopLocalVarRangeEndingPoint {
1251 BEFORE_STEPS,
1252 AFTER_STEPS,
1253 }
1255 /**
1256 * Checks whether we have reached an alive range ending point for local
1257 * variables after a loop.
1258 *
1259 * Local variables alive range ending point for loops varies depending
1260 * on the loop type. The range can be closed before or after the code
1261 * for the steps sentences has been generated.
1262 *
1263 * - While loops has no steps so in that case the range is closed just
1264 * after the body of the loop.
1265 *
1266 * - For-like loops may have steps so as long as the steps sentences
1267 * can possibly contain non-synthetic local variables, the alive range
1268 * for local variables must be closed after the steps in this case.
1269 */
1270 private void checkLoopLocalVarRangeEnding(JCTree loop, JCTree body,
1271 LoopLocalVarRangeEndingPoint endingPoint) {
1272 if (varDebugInfo && lvtRanges.containsKey(code.meth, body)) {
1273 switch (endingPoint) {
1274 case BEFORE_STEPS:
1275 if (!loop.hasTag(FORLOOP)) {
1276 code.closeAliveRanges(body);
1277 }
1278 break;
1279 case AFTER_STEPS:
1280 if (loop.hasTag(FORLOOP)) {
1281 code.closeAliveRanges(body);
1282 }
1283 break;
1284 }
1285 }
1286 }
1288 public void visitForeachLoop(JCEnhancedForLoop tree) {
1289 throw new AssertionError(); // should have been removed by Lower.
1290 }
1292 public void visitLabelled(JCLabeledStatement tree) {
1293 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1294 genStat(tree.body, localEnv, CRT_STATEMENT);
1295 code.resolve(localEnv.info.exit);
1296 }
1298 public void visitSwitch(JCSwitch tree) {
1299 int limit = code.nextreg;
1300 Assert.check(!tree.selector.type.hasTag(CLASS));
1301 int startpcCrt = genCrt ? code.curCP() : 0;
1302 Item sel = genExpr(tree.selector, syms.intType);
1303 List<JCCase> cases = tree.cases;
1304 if (cases.isEmpty()) {
1305 // We are seeing: switch <sel> {}
1306 sel.load().drop();
1307 if (genCrt)
1308 code.crt.put(TreeInfo.skipParens(tree.selector),
1309 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1310 } else {
1311 // We are seeing a nonempty switch.
1312 sel.load();
1313 if (genCrt)
1314 code.crt.put(TreeInfo.skipParens(tree.selector),
1315 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1316 Env<GenContext> switchEnv = env.dup(tree, new GenContext());
1317 switchEnv.info.isSwitch = true;
1319 // Compute number of labels and minimum and maximum label values.
1320 // For each case, store its label in an array.
1321 int lo = Integer.MAX_VALUE; // minimum label.
1322 int hi = Integer.MIN_VALUE; // maximum label.
1323 int nlabels = 0; // number of labels.
1325 int[] labels = new int[cases.length()]; // the label array.
1326 int defaultIndex = -1; // the index of the default clause.
1328 List<JCCase> l = cases;
1329 for (int i = 0; i < labels.length; i++) {
1330 if (l.head.pat != null) {
1331 int val = ((Number)l.head.pat.type.constValue()).intValue();
1332 labels[i] = val;
1333 if (val < lo) lo = val;
1334 if (hi < val) hi = val;
1335 nlabels++;
1336 } else {
1337 Assert.check(defaultIndex == -1);
1338 defaultIndex = i;
1339 }
1340 l = l.tail;
1341 }
1343 // Determine whether to issue a tableswitch or a lookupswitch
1344 // instruction.
1345 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1346 long table_time_cost = 3; // comparisons
1347 long lookup_space_cost = 3 + 2 * (long) nlabels;
1348 long lookup_time_cost = nlabels;
1349 int opcode =
1350 nlabels > 0 &&
1351 table_space_cost + 3 * table_time_cost <=
1352 lookup_space_cost + 3 * lookup_time_cost
1353 ?
1354 tableswitch : lookupswitch;
1356 int startpc = code.curCP(); // the position of the selector operation
1357 code.emitop0(opcode);
1358 code.align(4);
1359 int tableBase = code.curCP(); // the start of the jump table
1360 int[] offsets = null; // a table of offsets for a lookupswitch
1361 code.emit4(-1); // leave space for default offset
1362 if (opcode == tableswitch) {
1363 code.emit4(lo); // minimum label
1364 code.emit4(hi); // maximum label
1365 for (long i = lo; i <= hi; i++) { // leave space for jump table
1366 code.emit4(-1);
1367 }
1368 } else {
1369 code.emit4(nlabels); // number of labels
1370 for (int i = 0; i < nlabels; i++) {
1371 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1372 }
1373 offsets = new int[labels.length];
1374 }
1375 Code.State stateSwitch = code.state.dup();
1376 code.markDead();
1378 // For each case do:
1379 l = cases;
1380 for (int i = 0; i < labels.length; i++) {
1381 JCCase c = l.head;
1382 l = l.tail;
1384 int pc = code.entryPoint(stateSwitch);
1385 // Insert offset directly into code or else into the
1386 // offsets table.
1387 if (i != defaultIndex) {
1388 if (opcode == tableswitch) {
1389 code.put4(
1390 tableBase + 4 * (labels[i] - lo + 3),
1391 pc - startpc);
1392 } else {
1393 offsets[i] = pc - startpc;
1394 }
1395 } else {
1396 code.put4(tableBase, pc - startpc);
1397 }
1399 // Generate code for the statements in this case.
1400 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1401 if (varDebugInfo && lvtRanges.containsKey(code.meth, c.stats.last())) {
1402 code.closeAliveRanges(c.stats.last());
1403 }
1404 }
1406 // Resolve all breaks.
1407 code.resolve(switchEnv.info.exit);
1409 // If we have not set the default offset, we do so now.
1410 if (code.get4(tableBase) == -1) {
1411 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1412 }
1414 if (opcode == tableswitch) {
1415 // Let any unfilled slots point to the default case.
1416 int defaultOffset = code.get4(tableBase);
1417 for (long i = lo; i <= hi; i++) {
1418 int t = (int)(tableBase + 4 * (i - lo + 3));
1419 if (code.get4(t) == -1)
1420 code.put4(t, defaultOffset);
1421 }
1422 } else {
1423 // Sort non-default offsets and copy into lookup table.
1424 if (defaultIndex >= 0)
1425 for (int i = defaultIndex; i < labels.length - 1; i++) {
1426 labels[i] = labels[i+1];
1427 offsets[i] = offsets[i+1];
1428 }
1429 if (nlabels > 0)
1430 qsort2(labels, offsets, 0, nlabels - 1);
1431 for (int i = 0; i < nlabels; i++) {
1432 int caseidx = tableBase + 8 * (i + 1);
1433 code.put4(caseidx, labels[i]);
1434 code.put4(caseidx + 4, offsets[i]);
1435 }
1436 }
1437 }
1438 code.endScopes(limit);
1439 }
1440 //where
1441 /** Sort (int) arrays of keys and values
1442 */
1443 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1444 int i = lo;
1445 int j = hi;
1446 int pivot = keys[(i+j)/2];
1447 do {
1448 while (keys[i] < pivot) i++;
1449 while (pivot < keys[j]) j--;
1450 if (i <= j) {
1451 int temp1 = keys[i];
1452 keys[i] = keys[j];
1453 keys[j] = temp1;
1454 int temp2 = values[i];
1455 values[i] = values[j];
1456 values[j] = temp2;
1457 i++;
1458 j--;
1459 }
1460 } while (i <= j);
1461 if (lo < j) qsort2(keys, values, lo, j);
1462 if (i < hi) qsort2(keys, values, i, hi);
1463 }
1465 public void visitSynchronized(JCSynchronized tree) {
1466 int limit = code.nextreg;
1467 // Generate code to evaluate lock and save in temporary variable.
1468 final LocalItem lockVar = makeTemp(syms.objectType);
1469 genExpr(tree.lock, tree.lock.type).load().duplicate();
1470 lockVar.store();
1472 // Generate code to enter monitor.
1473 code.emitop0(monitorenter);
1474 code.state.lock(lockVar.reg);
1476 // Generate code for a try statement with given body, no catch clauses
1477 // in a new environment with the "exit-monitor" operation as finalizer.
1478 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1479 syncEnv.info.finalize = new GenFinalizer() {
1480 void gen() {
1481 genLast();
1482 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1483 syncEnv.info.gaps.append(code.curCP());
1484 }
1485 void genLast() {
1486 if (code.isAlive()) {
1487 lockVar.load();
1488 code.emitop0(monitorexit);
1489 code.state.unlock(lockVar.reg);
1490 }
1491 }
1492 };
1493 syncEnv.info.gaps = new ListBuffer<Integer>();
1494 genTry(tree.body, List.<JCCatch>nil(), syncEnv);
1495 code.endScopes(limit);
1496 }
1498 public void visitTry(final JCTry tree) {
1499 // Generate code for a try statement with given body and catch clauses,
1500 // in a new environment which calls the finally block if there is one.
1501 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1502 final Env<GenContext> oldEnv = env;
1503 if (!useJsrLocally) {
1504 useJsrLocally =
1505 (stackMap == StackMapFormat.NONE) &&
1506 (jsrlimit <= 0 ||
1507 jsrlimit < 100 &&
1508 estimateCodeComplexity(tree.finalizer)>jsrlimit);
1509 }
1510 tryEnv.info.finalize = new GenFinalizer() {
1511 void gen() {
1512 if (useJsrLocally) {
1513 if (tree.finalizer != null) {
1514 Code.State jsrState = code.state.dup();
1515 jsrState.push(Code.jsrReturnValue);
1516 tryEnv.info.cont =
1517 new Chain(code.emitJump(jsr),
1518 tryEnv.info.cont,
1519 jsrState);
1520 }
1521 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1522 tryEnv.info.gaps.append(code.curCP());
1523 } else {
1524 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1525 tryEnv.info.gaps.append(code.curCP());
1526 genLast();
1527 }
1528 }
1529 void genLast() {
1530 if (tree.finalizer != null)
1531 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1532 }
1533 boolean hasFinalizer() {
1534 return tree.finalizer != null;
1535 }
1536 };
1537 tryEnv.info.gaps = new ListBuffer<Integer>();
1538 genTry(tree.body, tree.catchers, tryEnv);
1539 }
1540 //where
1541 /** Generate code for a try or synchronized statement
1542 * @param body The body of the try or synchronized statement.
1543 * @param catchers The lis of catch clauses.
1544 * @param env the environment current for the body.
1545 */
1546 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1547 int limit = code.nextreg;
1548 int startpc = code.curCP();
1549 Code.State stateTry = code.state.dup();
1550 genStat(body, env, CRT_BLOCK);
1551 int endpc = code.curCP();
1552 boolean hasFinalizer =
1553 env.info.finalize != null &&
1554 env.info.finalize.hasFinalizer();
1555 List<Integer> gaps = env.info.gaps.toList();
1556 code.statBegin(TreeInfo.endPos(body));
1557 genFinalizer(env);
1558 code.statBegin(TreeInfo.endPos(env.tree));
1559 Chain exitChain = code.branch(goto_);
1560 if (varDebugInfo && lvtRanges.containsKey(code.meth, body)) {
1561 code.closeAliveRanges(body);
1562 }
1563 endFinalizerGap(env);
1564 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1565 // start off with exception on stack
1566 code.entryPoint(stateTry, l.head.param.sym.type);
1567 genCatch(l.head, env, startpc, endpc, gaps);
1568 genFinalizer(env);
1569 if (hasFinalizer || l.tail.nonEmpty()) {
1570 code.statBegin(TreeInfo.endPos(env.tree));
1571 exitChain = Code.mergeChains(exitChain,
1572 code.branch(goto_));
1573 }
1574 endFinalizerGap(env);
1575 }
1576 if (hasFinalizer) {
1577 // Create a new register segement to avoid allocating
1578 // the same variables in finalizers and other statements.
1579 code.newRegSegment();
1581 // Add a catch-all clause.
1583 // start off with exception on stack
1584 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1586 // Register all exception ranges for catch all clause.
1587 // The range of the catch all clause is from the beginning
1588 // of the try or synchronized block until the present
1589 // code pointer excluding all gaps in the current
1590 // environment's GenContext.
1591 int startseg = startpc;
1592 while (env.info.gaps.nonEmpty()) {
1593 int endseg = env.info.gaps.next().intValue();
1594 registerCatch(body.pos(), startseg, endseg,
1595 catchallpc, 0);
1596 startseg = env.info.gaps.next().intValue();
1597 }
1598 code.statBegin(TreeInfo.finalizerPos(env.tree));
1599 code.markStatBegin();
1601 Item excVar = makeTemp(syms.throwableType);
1602 excVar.store();
1603 genFinalizer(env);
1604 excVar.load();
1605 registerCatch(body.pos(), startseg,
1606 env.info.gaps.next().intValue(),
1607 catchallpc, 0);
1608 code.emitop0(athrow);
1609 code.markDead();
1611 // If there are jsr's to this finalizer, ...
1612 if (env.info.cont != null) {
1613 // Resolve all jsr's.
1614 code.resolve(env.info.cont);
1616 // Mark statement line number
1617 code.statBegin(TreeInfo.finalizerPos(env.tree));
1618 code.markStatBegin();
1620 // Save return address.
1621 LocalItem retVar = makeTemp(syms.throwableType);
1622 retVar.store();
1624 // Generate finalizer code.
1625 env.info.finalize.genLast();
1627 // Return.
1628 code.emitop1w(ret, retVar.reg);
1629 code.markDead();
1630 }
1631 }
1632 // Resolve all breaks.
1633 code.resolve(exitChain);
1635 code.endScopes(limit);
1636 }
1638 /** Generate code for a catch clause.
1639 * @param tree The catch clause.
1640 * @param env The environment current in the enclosing try.
1641 * @param startpc Start pc of try-block.
1642 * @param endpc End pc of try-block.
1643 */
1644 void genCatch(JCCatch tree,
1645 Env<GenContext> env,
1646 int startpc, int endpc,
1647 List<Integer> gaps) {
1648 if (startpc != endpc) {
1649 List<JCExpression> subClauses = TreeInfo.isMultiCatch(tree) ?
1650 ((JCTypeUnion)tree.param.vartype).alternatives :
1651 List.of(tree.param.vartype);
1652 while (gaps.nonEmpty()) {
1653 for (JCExpression subCatch : subClauses) {
1654 int catchType = makeRef(tree.pos(), subCatch.type);
1655 int end = gaps.head.intValue();
1656 registerCatch(tree.pos(),
1657 startpc, end, code.curCP(),
1658 catchType);
1659 if (subCatch.type.isAnnotated()) {
1660 for (Attribute.TypeCompound tc :
1661 subCatch.type.getAnnotationMirrors()) {
1662 tc.position.type_index = catchType;
1663 }
1664 }
1665 }
1666 gaps = gaps.tail;
1667 startpc = gaps.head.intValue();
1668 gaps = gaps.tail;
1669 }
1670 if (startpc < endpc) {
1671 for (JCExpression subCatch : subClauses) {
1672 int catchType = makeRef(tree.pos(), subCatch.type);
1673 registerCatch(tree.pos(),
1674 startpc, endpc, code.curCP(),
1675 catchType);
1676 if (subCatch.type.isAnnotated()) {
1677 for (Attribute.TypeCompound tc :
1678 subCatch.type.getAnnotationMirrors()) {
1679 tc.position.type_index = catchType;
1680 }
1681 }
1682 }
1683 }
1684 VarSymbol exparam = tree.param.sym;
1685 code.statBegin(tree.pos);
1686 code.markStatBegin();
1687 int limit = code.nextreg;
1688 int exlocal = code.newLocal(exparam);
1689 items.makeLocalItem(exparam).store();
1690 code.statBegin(TreeInfo.firstStatPos(tree.body));
1691 genStat(tree.body, env, CRT_BLOCK);
1692 code.endScopes(limit);
1693 code.statBegin(TreeInfo.endPos(tree.body));
1694 }
1695 }
1697 /** Register a catch clause in the "Exceptions" code-attribute.
1698 */
1699 void registerCatch(DiagnosticPosition pos,
1700 int startpc, int endpc,
1701 int handler_pc, int catch_type) {
1702 char startpc1 = (char)startpc;
1703 char endpc1 = (char)endpc;
1704 char handler_pc1 = (char)handler_pc;
1705 if (startpc1 == startpc &&
1706 endpc1 == endpc &&
1707 handler_pc1 == handler_pc) {
1708 code.addCatch(startpc1, endpc1, handler_pc1,
1709 (char)catch_type);
1710 } else {
1711 if (!useJsrLocally && !target.generateStackMapTable()) {
1712 useJsrLocally = true;
1713 throw new CodeSizeOverflow();
1714 } else {
1715 log.error(pos, "limit.code.too.large.for.try.stmt");
1716 nerrs++;
1717 }
1718 }
1719 }
1721 /** Very roughly estimate the number of instructions needed for
1722 * the given tree.
1723 */
1724 int estimateCodeComplexity(JCTree tree) {
1725 if (tree == null) return 0;
1726 class ComplexityScanner extends TreeScanner {
1727 int complexity = 0;
1728 public void scan(JCTree tree) {
1729 if (complexity > jsrlimit) return;
1730 super.scan(tree);
1731 }
1732 public void visitClassDef(JCClassDecl tree) {}
1733 public void visitDoLoop(JCDoWhileLoop tree)
1734 { super.visitDoLoop(tree); complexity++; }
1735 public void visitWhileLoop(JCWhileLoop tree)
1736 { super.visitWhileLoop(tree); complexity++; }
1737 public void visitForLoop(JCForLoop tree)
1738 { super.visitForLoop(tree); complexity++; }
1739 public void visitSwitch(JCSwitch tree)
1740 { super.visitSwitch(tree); complexity+=5; }
1741 public void visitCase(JCCase tree)
1742 { super.visitCase(tree); complexity++; }
1743 public void visitSynchronized(JCSynchronized tree)
1744 { super.visitSynchronized(tree); complexity+=6; }
1745 public void visitTry(JCTry tree)
1746 { super.visitTry(tree);
1747 if (tree.finalizer != null) complexity+=6; }
1748 public void visitCatch(JCCatch tree)
1749 { super.visitCatch(tree); complexity+=2; }
1750 public void visitConditional(JCConditional tree)
1751 { super.visitConditional(tree); complexity+=2; }
1752 public void visitIf(JCIf tree)
1753 { super.visitIf(tree); complexity+=2; }
1754 // note: for break, continue, and return we don't take unwind() into account.
1755 public void visitBreak(JCBreak tree)
1756 { super.visitBreak(tree); complexity+=1; }
1757 public void visitContinue(JCContinue tree)
1758 { super.visitContinue(tree); complexity+=1; }
1759 public void visitReturn(JCReturn tree)
1760 { super.visitReturn(tree); complexity+=1; }
1761 public void visitThrow(JCThrow tree)
1762 { super.visitThrow(tree); complexity+=1; }
1763 public void visitAssert(JCAssert tree)
1764 { super.visitAssert(tree); complexity+=5; }
1765 public void visitApply(JCMethodInvocation tree)
1766 { super.visitApply(tree); complexity+=2; }
1767 public void visitNewClass(JCNewClass tree)
1768 { scan(tree.encl); scan(tree.args); complexity+=2; }
1769 public void visitNewArray(JCNewArray tree)
1770 { super.visitNewArray(tree); complexity+=5; }
1771 public void visitAssign(JCAssign tree)
1772 { super.visitAssign(tree); complexity+=1; }
1773 public void visitAssignop(JCAssignOp tree)
1774 { super.visitAssignop(tree); complexity+=2; }
1775 public void visitUnary(JCUnary tree)
1776 { complexity+=1;
1777 if (tree.type.constValue() == null) super.visitUnary(tree); }
1778 public void visitBinary(JCBinary tree)
1779 { complexity+=1;
1780 if (tree.type.constValue() == null) super.visitBinary(tree); }
1781 public void visitTypeTest(JCInstanceOf tree)
1782 { super.visitTypeTest(tree); complexity+=1; }
1783 public void visitIndexed(JCArrayAccess tree)
1784 { super.visitIndexed(tree); complexity+=1; }
1785 public void visitSelect(JCFieldAccess tree)
1786 { super.visitSelect(tree);
1787 if (tree.sym.kind == VAR) complexity+=1; }
1788 public void visitIdent(JCIdent tree) {
1789 if (tree.sym.kind == VAR) {
1790 complexity+=1;
1791 if (tree.type.constValue() == null &&
1792 tree.sym.owner.kind == TYP)
1793 complexity+=1;
1794 }
1795 }
1796 public void visitLiteral(JCLiteral tree)
1797 { complexity+=1; }
1798 public void visitTree(JCTree tree) {}
1799 public void visitWildcard(JCWildcard tree) {
1800 throw new AssertionError(this.getClass().getName());
1801 }
1802 }
1803 ComplexityScanner scanner = new ComplexityScanner();
1804 tree.accept(scanner);
1805 return scanner.complexity;
1806 }
1808 public void visitIf(JCIf tree) {
1809 int limit = code.nextreg;
1810 Chain thenExit = null;
1811 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1812 CRT_FLOW_CONTROLLER);
1813 Chain elseChain = c.jumpFalse();
1814 if (!c.isFalse()) {
1815 code.resolve(c.trueJumps);
1816 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1817 thenExit = code.branch(goto_);
1818 if (varDebugInfo && lvtRanges.containsKey(code.meth, tree.thenpart)) {
1819 code.closeAliveRanges(tree.thenpart, code.cp);
1820 }
1821 }
1822 if (elseChain != null) {
1823 code.resolve(elseChain);
1824 if (tree.elsepart != null) {
1825 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1826 if (varDebugInfo && lvtRanges.containsKey(code.meth, tree.elsepart)) {
1827 code.closeAliveRanges(tree.elsepart);
1828 }
1829 }
1830 }
1831 code.resolve(thenExit);
1832 code.endScopes(limit);
1833 }
1835 public void visitExec(JCExpressionStatement tree) {
1836 // Optimize x++ to ++x and x-- to --x.
1837 JCExpression e = tree.expr;
1838 switch (e.getTag()) {
1839 case POSTINC:
1840 ((JCUnary) e).setTag(PREINC);
1841 break;
1842 case POSTDEC:
1843 ((JCUnary) e).setTag(PREDEC);
1844 break;
1845 }
1846 genExpr(tree.expr, tree.expr.type).drop();
1847 }
1849 public void visitBreak(JCBreak tree) {
1850 Env<GenContext> targetEnv = unwind(tree.target, env);
1851 Assert.check(code.state.stacksize == 0);
1852 targetEnv.info.addExit(code.branch(goto_));
1853 endFinalizerGaps(env, targetEnv);
1854 }
1856 public void visitContinue(JCContinue tree) {
1857 Env<GenContext> targetEnv = unwind(tree.target, env);
1858 Assert.check(code.state.stacksize == 0);
1859 targetEnv.info.addCont(code.branch(goto_));
1860 endFinalizerGaps(env, targetEnv);
1861 }
1863 public void visitReturn(JCReturn tree) {
1864 int limit = code.nextreg;
1865 final Env<GenContext> targetEnv;
1866 if (tree.expr != null) {
1867 Item r = genExpr(tree.expr, pt).load();
1868 if (hasFinally(env.enclMethod, env)) {
1869 r = makeTemp(pt);
1870 r.store();
1871 }
1872 targetEnv = unwind(env.enclMethod, env);
1873 r.load();
1874 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
1875 } else {
1876 /* If we have a statement like:
1877 *
1878 * return;
1879 *
1880 * we need to store the code.pendingStatPos value before generating
1881 * the finalizer.
1882 */
1883 int tmpPos = code.pendingStatPos;
1884 targetEnv = unwind(env.enclMethod, env);
1885 code.pendingStatPos = tmpPos;
1886 code.emitop0(return_);
1887 }
1888 endFinalizerGaps(env, targetEnv);
1889 code.endScopes(limit);
1890 }
1892 public void visitThrow(JCThrow tree) {
1893 genExpr(tree.expr, tree.expr.type).load();
1894 code.emitop0(athrow);
1895 }
1897 /* ************************************************************************
1898 * Visitor methods for expressions
1899 *************************************************************************/
1901 public void visitApply(JCMethodInvocation tree) {
1902 setTypeAnnotationPositions(tree.pos);
1903 // Generate code for method.
1904 Item m = genExpr(tree.meth, methodType);
1905 // Generate code for all arguments, where the expected types are
1906 // the parameters of the method's external type (that is, any implicit
1907 // outer instance of a super(...) call appears as first parameter).
1908 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
1909 genArgs(tree.args,
1910 msym.externalType(types).getParameterTypes());
1911 if (!msym.isDynamic()) {
1912 code.statBegin(tree.pos);
1913 }
1914 result = m.invoke();
1915 }
1917 public void visitConditional(JCConditional tree) {
1918 Chain thenExit = null;
1919 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
1920 Chain elseChain = c.jumpFalse();
1921 if (!c.isFalse()) {
1922 code.resolve(c.trueJumps);
1923 int startpc = genCrt ? code.curCP() : 0;
1924 genExpr(tree.truepart, pt).load();
1925 code.state.forceStackTop(tree.type);
1926 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
1927 startpc, code.curCP());
1928 thenExit = code.branch(goto_);
1929 }
1930 if (elseChain != null) {
1931 code.resolve(elseChain);
1932 int startpc = genCrt ? code.curCP() : 0;
1933 genExpr(tree.falsepart, pt).load();
1934 code.state.forceStackTop(tree.type);
1935 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
1936 startpc, code.curCP());
1937 }
1938 code.resolve(thenExit);
1939 result = items.makeStackItem(pt);
1940 }
1942 private void setTypeAnnotationPositions(int treePos) {
1943 MethodSymbol meth = code.meth;
1944 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR
1945 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT;
1947 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
1948 if (ta.hasUnknownPosition())
1949 ta.tryFixPosition();
1951 if (ta.position.matchesPos(treePos))
1952 ta.position.updatePosOffset(code.cp);
1953 }
1955 if (!initOrClinit)
1956 return;
1958 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
1959 if (ta.hasUnknownPosition())
1960 ta.tryFixPosition();
1962 if (ta.position.matchesPos(treePos))
1963 ta.position.updatePosOffset(code.cp);
1964 }
1966 ClassSymbol clazz = meth.enclClass();
1967 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
1968 if (!s.getKind().isField())
1969 continue;
1971 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
1972 if (ta.hasUnknownPosition())
1973 ta.tryFixPosition();
1975 if (ta.position.matchesPos(treePos))
1976 ta.position.updatePosOffset(code.cp);
1977 }
1978 }
1979 }
1981 public void visitNewClass(JCNewClass tree) {
1982 // Enclosing instances or anonymous classes should have been eliminated
1983 // by now.
1984 Assert.check(tree.encl == null && tree.def == null);
1985 setTypeAnnotationPositions(tree.pos);
1987 code.emitop2(new_, makeRef(tree.pos(), tree.type));
1988 code.emitop0(dup);
1990 // Generate code for all arguments, where the expected types are
1991 // the parameters of the constructor's external type (that is,
1992 // any implicit outer instance appears as first parameter).
1993 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
1995 items.makeMemberItem(tree.constructor, true).invoke();
1996 result = items.makeStackItem(tree.type);
1997 }
1999 public void visitNewArray(JCNewArray tree) {
2000 setTypeAnnotationPositions(tree.pos);
2002 if (tree.elems != null) {
2003 Type elemtype = types.elemtype(tree.type);
2004 loadIntConst(tree.elems.length());
2005 Item arr = makeNewArray(tree.pos(), tree.type, 1);
2006 int i = 0;
2007 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
2008 arr.duplicate();
2009 loadIntConst(i);
2010 i++;
2011 genExpr(l.head, elemtype).load();
2012 items.makeIndexedItem(elemtype).store();
2013 }
2014 result = arr;
2015 } else {
2016 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
2017 genExpr(l.head, syms.intType).load();
2018 }
2019 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
2020 }
2021 }
2022 //where
2023 /** Generate code to create an array with given element type and number
2024 * of dimensions.
2025 */
2026 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
2027 Type elemtype = types.elemtype(type);
2028 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
2029 log.error(pos, "limit.dimensions");
2030 nerrs++;
2031 }
2032 int elemcode = Code.arraycode(elemtype);
2033 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
2034 code.emitAnewarray(makeRef(pos, elemtype), type);
2035 } else if (elemcode == 1) {
2036 code.emitMultianewarray(ndims, makeRef(pos, type), type);
2037 } else {
2038 code.emitNewarray(elemcode, type);
2039 }
2040 return items.makeStackItem(type);
2041 }
2043 public void visitParens(JCParens tree) {
2044 result = genExpr(tree.expr, tree.expr.type);
2045 }
2047 public void visitAssign(JCAssign tree) {
2048 Item l = genExpr(tree.lhs, tree.lhs.type);
2049 genExpr(tree.rhs, tree.lhs.type).load();
2050 result = items.makeAssignItem(l);
2051 }
2053 public void visitAssignop(JCAssignOp tree) {
2054 OperatorSymbol operator = (OperatorSymbol) tree.operator;
2055 Item l;
2056 if (operator.opcode == string_add) {
2057 // Generate code to make a string buffer
2058 makeStringBuffer(tree.pos());
2060 // Generate code for first string, possibly save one
2061 // copy under buffer
2062 l = genExpr(tree.lhs, tree.lhs.type);
2063 if (l.width() > 0) {
2064 code.emitop0(dup_x1 + 3 * (l.width() - 1));
2065 }
2067 // Load first string and append to buffer.
2068 l.load();
2069 appendString(tree.lhs);
2071 // Append all other strings to buffer.
2072 appendStrings(tree.rhs);
2074 // Convert buffer to string.
2075 bufferToString(tree.pos());
2076 } else {
2077 // Generate code for first expression
2078 l = genExpr(tree.lhs, tree.lhs.type);
2080 // If we have an increment of -32768 to +32767 of a local
2081 // int variable we can use an incr instruction instead of
2082 // proceeding further.
2083 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
2084 l instanceof LocalItem &&
2085 tree.lhs.type.getTag().isSubRangeOf(INT) &&
2086 tree.rhs.type.getTag().isSubRangeOf(INT) &&
2087 tree.rhs.type.constValue() != null) {
2088 int ival = ((Number) tree.rhs.type.constValue()).intValue();
2089 if (tree.hasTag(MINUS_ASG)) ival = -ival;
2090 ((LocalItem)l).incr(ival);
2091 result = l;
2092 return;
2093 }
2094 // Otherwise, duplicate expression, load one copy
2095 // and complete binary operation.
2096 l.duplicate();
2097 l.coerce(operator.type.getParameterTypes().head).load();
2098 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
2099 }
2100 result = items.makeAssignItem(l);
2101 }
2103 public void visitUnary(JCUnary tree) {
2104 OperatorSymbol operator = (OperatorSymbol)tree.operator;
2105 if (tree.hasTag(NOT)) {
2106 CondItem od = genCond(tree.arg, false);
2107 result = od.negate();
2108 } else {
2109 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
2110 switch (tree.getTag()) {
2111 case POS:
2112 result = od.load();
2113 break;
2114 case NEG:
2115 result = od.load();
2116 code.emitop0(operator.opcode);
2117 break;
2118 case COMPL:
2119 result = od.load();
2120 emitMinusOne(od.typecode);
2121 code.emitop0(operator.opcode);
2122 break;
2123 case PREINC: case PREDEC:
2124 od.duplicate();
2125 if (od instanceof LocalItem &&
2126 (operator.opcode == iadd || operator.opcode == isub)) {
2127 ((LocalItem)od).incr(tree.hasTag(PREINC) ? 1 : -1);
2128 result = od;
2129 } else {
2130 od.load();
2131 code.emitop0(one(od.typecode));
2132 code.emitop0(operator.opcode);
2133 // Perform narrowing primitive conversion if byte,
2134 // char, or short. Fix for 4304655.
2135 if (od.typecode != INTcode &&
2136 Code.truncate(od.typecode) == INTcode)
2137 code.emitop0(int2byte + od.typecode - BYTEcode);
2138 result = items.makeAssignItem(od);
2139 }
2140 break;
2141 case POSTINC: case POSTDEC:
2142 od.duplicate();
2143 if (od instanceof LocalItem &&
2144 (operator.opcode == iadd || operator.opcode == isub)) {
2145 Item res = od.load();
2146 ((LocalItem)od).incr(tree.hasTag(POSTINC) ? 1 : -1);
2147 result = res;
2148 } else {
2149 Item res = od.load();
2150 od.stash(od.typecode);
2151 code.emitop0(one(od.typecode));
2152 code.emitop0(operator.opcode);
2153 // Perform narrowing primitive conversion if byte,
2154 // char, or short. Fix for 4304655.
2155 if (od.typecode != INTcode &&
2156 Code.truncate(od.typecode) == INTcode)
2157 code.emitop0(int2byte + od.typecode - BYTEcode);
2158 od.store();
2159 result = res;
2160 }
2161 break;
2162 case NULLCHK:
2163 result = od.load();
2164 code.emitop0(dup);
2165 genNullCheck(tree.pos());
2166 break;
2167 default:
2168 Assert.error();
2169 }
2170 }
2171 }
2173 /** Generate a null check from the object value at stack top. */
2174 private void genNullCheck(DiagnosticPosition pos) {
2175 callMethod(pos, syms.objectType, names.getClass,
2176 List.<Type>nil(), false);
2177 code.emitop0(pop);
2178 }
2180 public void visitBinary(JCBinary tree) {
2181 OperatorSymbol operator = (OperatorSymbol)tree.operator;
2182 if (operator.opcode == string_add) {
2183 // Create a string buffer.
2184 makeStringBuffer(tree.pos());
2185 // Append all strings to buffer.
2186 appendStrings(tree);
2187 // Convert buffer to string.
2188 bufferToString(tree.pos());
2189 result = items.makeStackItem(syms.stringType);
2190 } else if (tree.hasTag(AND)) {
2191 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2192 if (!lcond.isFalse()) {
2193 Chain falseJumps = lcond.jumpFalse();
2194 code.resolve(lcond.trueJumps);
2195 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2196 result = items.
2197 makeCondItem(rcond.opcode,
2198 rcond.trueJumps,
2199 Code.mergeChains(falseJumps,
2200 rcond.falseJumps));
2201 } else {
2202 result = lcond;
2203 }
2204 } else if (tree.hasTag(OR)) {
2205 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2206 if (!lcond.isTrue()) {
2207 Chain trueJumps = lcond.jumpTrue();
2208 code.resolve(lcond.falseJumps);
2209 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2210 result = items.
2211 makeCondItem(rcond.opcode,
2212 Code.mergeChains(trueJumps, rcond.trueJumps),
2213 rcond.falseJumps);
2214 } else {
2215 result = lcond;
2216 }
2217 } else {
2218 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
2219 od.load();
2220 result = completeBinop(tree.lhs, tree.rhs, operator);
2221 }
2222 }
2223 //where
2224 /** Make a new string buffer.
2225 */
2226 void makeStringBuffer(DiagnosticPosition pos) {
2227 code.emitop2(new_, makeRef(pos, stringBufferType));
2228 code.emitop0(dup);
2229 callMethod(
2230 pos, stringBufferType, names.init, List.<Type>nil(), false);
2231 }
2233 /** Append value (on tos) to string buffer (on tos - 1).
2234 */
2235 void appendString(JCTree tree) {
2236 Type t = tree.type.baseType();
2237 if (!t.isPrimitive() && t.tsym != syms.stringType.tsym) {
2238 t = syms.objectType;
2239 }
2240 items.makeMemberItem(getStringBufferAppend(tree, t), false).invoke();
2241 }
2242 Symbol getStringBufferAppend(JCTree tree, Type t) {
2243 Assert.checkNull(t.constValue());
2244 Symbol method = stringBufferAppend.get(t);
2245 if (method == null) {
2246 method = rs.resolveInternalMethod(tree.pos(),
2247 attrEnv,
2248 stringBufferType,
2249 names.append,
2250 List.of(t),
2251 null);
2252 stringBufferAppend.put(t, method);
2253 }
2254 return method;
2255 }
2257 /** Add all strings in tree to string buffer.
2258 */
2259 void appendStrings(JCTree tree) {
2260 tree = TreeInfo.skipParens(tree);
2261 if (tree.hasTag(PLUS) && tree.type.constValue() == null) {
2262 JCBinary op = (JCBinary) tree;
2263 if (op.operator.kind == MTH &&
2264 ((OperatorSymbol) op.operator).opcode == string_add) {
2265 appendStrings(op.lhs);
2266 appendStrings(op.rhs);
2267 return;
2268 }
2269 }
2270 genExpr(tree, tree.type).load();
2271 appendString(tree);
2272 }
2274 /** Convert string buffer on tos to string.
2275 */
2276 void bufferToString(DiagnosticPosition pos) {
2277 callMethod(
2278 pos,
2279 stringBufferType,
2280 names.toString,
2281 List.<Type>nil(),
2282 false);
2283 }
2285 /** Complete generating code for operation, with left operand
2286 * already on stack.
2287 * @param lhs The tree representing the left operand.
2288 * @param rhs The tree representing the right operand.
2289 * @param operator The operator symbol.
2290 */
2291 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2292 MethodType optype = (MethodType)operator.type;
2293 int opcode = operator.opcode;
2294 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2295 rhs.type.constValue() instanceof Number &&
2296 ((Number) rhs.type.constValue()).intValue() == 0) {
2297 opcode = opcode + (ifeq - if_icmpeq);
2298 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2299 TreeInfo.isNull(rhs)) {
2300 opcode = opcode + (if_acmp_null - if_acmpeq);
2301 } else {
2302 // The expected type of the right operand is
2303 // the second parameter type of the operator, except for
2304 // shifts with long shiftcount, where we convert the opcode
2305 // to a short shift and the expected type to int.
2306 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2307 if (opcode >= ishll && opcode <= lushrl) {
2308 opcode = opcode + (ishl - ishll);
2309 rtype = syms.intType;
2310 }
2311 // Generate code for right operand and load.
2312 genExpr(rhs, rtype).load();
2313 // If there are two consecutive opcode instructions,
2314 // emit the first now.
2315 if (opcode >= (1 << preShift)) {
2316 code.emitop0(opcode >> preShift);
2317 opcode = opcode & 0xFF;
2318 }
2319 }
2320 if (opcode >= ifeq && opcode <= if_acmpne ||
2321 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2322 return items.makeCondItem(opcode);
2323 } else {
2324 code.emitop0(opcode);
2325 return items.makeStackItem(optype.restype);
2326 }
2327 }
2329 public void visitTypeCast(JCTypeCast tree) {
2330 setTypeAnnotationPositions(tree.pos);
2331 result = genExpr(tree.expr, tree.clazz.type).load();
2332 // Additional code is only needed if we cast to a reference type
2333 // which is not statically a supertype of the expression's type.
2334 // For basic types, the coerce(...) in genExpr(...) will do
2335 // the conversion.
2336 if (!tree.clazz.type.isPrimitive() &&
2337 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2338 code.emitop2(checkcast, makeRef(tree.pos(), tree.clazz.type));
2339 }
2340 }
2342 public void visitWildcard(JCWildcard tree) {
2343 throw new AssertionError(this.getClass().getName());
2344 }
2346 public void visitTypeTest(JCInstanceOf tree) {
2347 setTypeAnnotationPositions(tree.pos);
2348 genExpr(tree.expr, tree.expr.type).load();
2349 code.emitop2(instanceof_, makeRef(tree.pos(), tree.clazz.type));
2350 result = items.makeStackItem(syms.booleanType);
2351 }
2353 public void visitIndexed(JCArrayAccess tree) {
2354 genExpr(tree.indexed, tree.indexed.type).load();
2355 genExpr(tree.index, syms.intType).load();
2356 result = items.makeIndexedItem(tree.type);
2357 }
2359 public void visitIdent(JCIdent tree) {
2360 Symbol sym = tree.sym;
2361 if (tree.name == names._this || tree.name == names._super) {
2362 Item res = tree.name == names._this
2363 ? items.makeThisItem()
2364 : items.makeSuperItem();
2365 if (sym.kind == MTH) {
2366 // Generate code to address the constructor.
2367 res.load();
2368 res = items.makeMemberItem(sym, true);
2369 }
2370 result = res;
2371 } else if (sym.kind == VAR && sym.owner.kind == MTH) {
2372 result = items.makeLocalItem((VarSymbol)sym);
2373 } else if (isInvokeDynamic(sym)) {
2374 result = items.makeDynamicItem(sym);
2375 } else if ((sym.flags() & STATIC) != 0) {
2376 if (!isAccessSuper(env.enclMethod))
2377 sym = binaryQualifier(sym, env.enclClass.type);
2378 result = items.makeStaticItem(sym);
2379 } else {
2380 items.makeThisItem().load();
2381 sym = binaryQualifier(sym, env.enclClass.type);
2382 result = items.makeMemberItem(sym, (sym.flags() & PRIVATE) != 0);
2383 }
2384 }
2386 public void visitSelect(JCFieldAccess tree) {
2387 Symbol sym = tree.sym;
2389 if (tree.name == names._class) {
2390 Assert.check(target.hasClassLiterals());
2391 code.emitLdc(makeRef(tree.pos(), tree.selected.type));
2392 result = items.makeStackItem(pt);
2393 return;
2394 }
2396 Symbol ssym = TreeInfo.symbol(tree.selected);
2398 // Are we selecting via super?
2399 boolean selectSuper =
2400 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2402 // Are we accessing a member of the superclass in an access method
2403 // resulting from a qualified super?
2404 boolean accessSuper = isAccessSuper(env.enclMethod);
2406 Item base = (selectSuper)
2407 ? items.makeSuperItem()
2408 : genExpr(tree.selected, tree.selected.type);
2410 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2411 // We are seeing a variable that is constant but its selecting
2412 // expression is not.
2413 if ((sym.flags() & STATIC) != 0) {
2414 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2415 base = base.load();
2416 base.drop();
2417 } else {
2418 base.load();
2419 genNullCheck(tree.selected.pos());
2420 }
2421 result = items.
2422 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2423 } else {
2424 if (isInvokeDynamic(sym)) {
2425 result = items.makeDynamicItem(sym);
2426 return;
2427 } else {
2428 sym = binaryQualifier(sym, tree.selected.type);
2429 }
2430 if ((sym.flags() & STATIC) != 0) {
2431 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2432 base = base.load();
2433 base.drop();
2434 result = items.makeStaticItem(sym);
2435 } else {
2436 base.load();
2437 if (sym == syms.lengthVar) {
2438 code.emitop0(arraylength);
2439 result = items.makeStackItem(syms.intType);
2440 } else {
2441 result = items.
2442 makeMemberItem(sym,
2443 (sym.flags() & PRIVATE) != 0 ||
2444 selectSuper || accessSuper);
2445 }
2446 }
2447 }
2448 }
2450 public boolean isInvokeDynamic(Symbol sym) {
2451 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
2452 }
2454 public void visitLiteral(JCLiteral tree) {
2455 if (tree.type.hasTag(BOT)) {
2456 code.emitop0(aconst_null);
2457 if (types.dimensions(pt) > 1) {
2458 code.emitop2(checkcast, makeRef(tree.pos(), pt));
2459 result = items.makeStackItem(pt);
2460 } else {
2461 result = items.makeStackItem(tree.type);
2462 }
2463 }
2464 else
2465 result = items.makeImmediateItem(tree.type, tree.value);
2466 }
2468 public void visitLetExpr(LetExpr tree) {
2469 int limit = code.nextreg;
2470 genStats(tree.defs, env);
2471 result = genExpr(tree.expr, tree.expr.type).load();
2472 code.endScopes(limit);
2473 }
2475 private void generateReferencesToPrunedTree(ClassSymbol classSymbol, Pool pool) {
2476 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
2477 if (prunedInfo != null) {
2478 for (JCTree prunedTree: prunedInfo) {
2479 prunedTree.accept(classReferenceVisitor);
2480 }
2481 }
2482 }
2484 /* ************************************************************************
2485 * main method
2486 *************************************************************************/
2488 /** Generate code for a class definition.
2489 * @param env The attribution environment that belongs to the
2490 * outermost class containing this class definition.
2491 * We need this for resolving some additional symbols.
2492 * @param cdef The tree representing the class definition.
2493 * @return True if code is generated with no errors.
2494 */
2495 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2496 try {
2497 attrEnv = env;
2498 ClassSymbol c = cdef.sym;
2499 this.toplevel = env.toplevel;
2500 this.endPosTable = toplevel.endPositions;
2501 // If this is a class definition requiring Miranda methods,
2502 // add them.
2503 if (generateIproxies &&
2504 (c.flags() & (INTERFACE|ABSTRACT)) == ABSTRACT
2505 && !allowGenerics // no Miranda methods available with generics
2506 )
2507 implementInterfaceMethods(c);
2508 cdef.defs = normalizeDefs(cdef.defs, c);
2509 c.pool = pool;
2510 pool.reset();
2511 generateReferencesToPrunedTree(c, pool);
2512 Env<GenContext> localEnv =
2513 new Env<GenContext>(cdef, new GenContext());
2514 localEnv.toplevel = env.toplevel;
2515 localEnv.enclClass = cdef;
2517 /* We must not analyze synthetic methods
2518 */
2519 if (varDebugInfo && (cdef.sym.flags() & SYNTHETIC) == 0) {
2520 try {
2521 new LVTAssignAnalyzer().analyzeTree(localEnv);
2522 } catch (Throwable e) {
2523 throw e;
2524 }
2525 }
2527 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2528 genDef(l.head, localEnv);
2529 }
2530 if (pool.numEntries() > Pool.MAX_ENTRIES) {
2531 log.error(cdef.pos(), "limit.pool");
2532 nerrs++;
2533 }
2534 if (nerrs != 0) {
2535 // if errors, discard code
2536 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2537 if (l.head.hasTag(METHODDEF))
2538 ((JCMethodDecl) l.head).sym.code = null;
2539 }
2540 }
2541 cdef.defs = List.nil(); // discard trees
2542 return nerrs == 0;
2543 } finally {
2544 // note: this method does NOT support recursion.
2545 attrEnv = null;
2546 this.env = null;
2547 toplevel = null;
2548 endPosTable = null;
2549 nerrs = 0;
2550 }
2551 }
2553 /* ************************************************************************
2554 * Auxiliary classes
2555 *************************************************************************/
2557 /** An abstract class for finalizer generation.
2558 */
2559 abstract class GenFinalizer {
2560 /** Generate code to clean up when unwinding. */
2561 abstract void gen();
2563 /** Generate code to clean up at last. */
2564 abstract void genLast();
2566 /** Does this finalizer have some nontrivial cleanup to perform? */
2567 boolean hasFinalizer() { return true; }
2568 }
2570 /** code generation contexts,
2571 * to be used as type parameter for environments.
2572 */
2573 static class GenContext {
2575 /** A chain for all unresolved jumps that exit the current environment.
2576 */
2577 Chain exit = null;
2579 /** A chain for all unresolved jumps that continue in the
2580 * current environment.
2581 */
2582 Chain cont = null;
2584 /** A closure that generates the finalizer of the current environment.
2585 * Only set for Synchronized and Try contexts.
2586 */
2587 GenFinalizer finalize = null;
2589 /** Is this a switch statement? If so, allocate registers
2590 * even when the variable declaration is unreachable.
2591 */
2592 boolean isSwitch = false;
2594 /** A list buffer containing all gaps in the finalizer range,
2595 * where a catch all exception should not apply.
2596 */
2597 ListBuffer<Integer> gaps = null;
2599 /** Add given chain to exit chain.
2600 */
2601 void addExit(Chain c) {
2602 exit = Code.mergeChains(c, exit);
2603 }
2605 /** Add given chain to cont chain.
2606 */
2607 void addCont(Chain c) {
2608 cont = Code.mergeChains(c, cont);
2609 }
2610 }
2612 class LVTAssignAnalyzer
2613 extends Flow.AbstractAssignAnalyzer<LVTAssignAnalyzer.LVTAssignPendingExit> {
2615 final LVTBits lvtInits;
2617 /* This class is anchored to a context dependent tree. The tree can
2618 * vary inside the same instruction for example in the switch instruction
2619 * the same FlowBits instance can be anchored to the whole tree, or
2620 * to a given case. The aim is to always anchor the bits to the tree
2621 * capable of closing a DA range.
2622 */
2623 class LVTBits extends Bits {
2625 JCTree currentTree;
2626 private int[] oldBits = null;
2627 BitsState stateBeforeOp;
2629 @Override
2630 public void clear() {
2631 generalOp(null, -1, BitsOpKind.CLEAR);
2632 }
2634 @Override
2635 protected void internalReset() {
2636 super.internalReset();
2637 oldBits = null;
2638 }
2640 @Override
2641 public Bits assign(Bits someBits) {
2642 // bits can be null
2643 oldBits = bits;
2644 stateBeforeOp = currentState;
2645 super.assign(someBits);
2646 changed();
2647 return this;
2648 }
2650 @Override
2651 public void excludeFrom(int start) {
2652 generalOp(null, start, BitsOpKind.EXCL_RANGE);
2653 }
2655 @Override
2656 public void excl(int x) {
2657 Assert.check(x >= 0);
2658 generalOp(null, x, BitsOpKind.EXCL_BIT);
2659 }
2661 @Override
2662 public Bits andSet(Bits xs) {
2663 return generalOp(xs, -1, BitsOpKind.AND_SET);
2664 }
2666 @Override
2667 public Bits orSet(Bits xs) {
2668 return generalOp(xs, -1, BitsOpKind.OR_SET);
2669 }
2671 @Override
2672 public Bits diffSet(Bits xs) {
2673 return generalOp(xs, -1, BitsOpKind.DIFF_SET);
2674 }
2676 @Override
2677 public Bits xorSet(Bits xs) {
2678 return generalOp(xs, -1, BitsOpKind.XOR_SET);
2679 }
2681 private Bits generalOp(Bits xs, int i, BitsOpKind opKind) {
2682 Assert.check(currentState != BitsState.UNKNOWN);
2683 oldBits = dupBits();
2684 stateBeforeOp = currentState;
2685 switch (opKind) {
2686 case AND_SET:
2687 super.andSet(xs);
2688 break;
2689 case OR_SET:
2690 super.orSet(xs);
2691 break;
2692 case XOR_SET:
2693 super.xorSet(xs);
2694 break;
2695 case DIFF_SET:
2696 super.diffSet(xs);
2697 break;
2698 case CLEAR:
2699 super.clear();
2700 break;
2701 case EXCL_BIT:
2702 super.excl(i);
2703 break;
2704 case EXCL_RANGE:
2705 super.excludeFrom(i);
2706 break;
2707 }
2708 changed();
2709 return this;
2710 }
2712 /* The tree we need to anchor the bits instance to.
2713 */
2714 LVTBits at(JCTree tree) {
2715 this.currentTree = tree;
2716 return this;
2717 }
2719 /* If the instance should be changed but the tree is not a closing
2720 * tree then a reset is needed or the former tree can mistakingly be
2721 * used.
2722 */
2723 LVTBits resetTree() {
2724 this.currentTree = null;
2725 return this;
2726 }
2728 /** This method will be called after any operation that causes a change to
2729 * the bits. Subclasses can thus override it in order to extract information
2730 * from the changes produced to the bits by the given operation.
2731 */
2732 public void changed() {
2733 if (currentTree != null &&
2734 stateBeforeOp != BitsState.UNKNOWN &&
2735 trackTree(currentTree)) {
2736 List<VarSymbol> locals = lvtRanges
2737 .getVars(currentMethod, currentTree);
2738 locals = locals != null ?
2739 locals : List.<VarSymbol>nil();
2740 for (JCVariableDecl vardecl : vardecls) {
2741 //once the first is null, the rest will be so.
2742 if (vardecl == null) {
2743 break;
2744 }
2745 if (trackVar(vardecl.sym) && bitChanged(vardecl.sym.adr)) {
2746 locals = locals.prepend(vardecl.sym);
2747 }
2748 }
2749 if (!locals.isEmpty()) {
2750 lvtRanges.setEntry(currentMethod,
2751 currentTree, locals);
2752 }
2753 }
2754 }
2756 boolean bitChanged(int x) {
2757 boolean isMemberOfBits = isMember(x);
2758 int[] tmp = bits;
2759 bits = oldBits;
2760 boolean isMemberOfOldBits = isMember(x);
2761 bits = tmp;
2762 return (!isMemberOfBits && isMemberOfOldBits);
2763 }
2765 boolean trackVar(VarSymbol var) {
2766 return (var.owner.kind == MTH &&
2767 (var.flags() & PARAMETER) == 0 &&
2768 trackable(var));
2769 }
2771 boolean trackTree(JCTree tree) {
2772 switch (tree.getTag()) {
2773 // of course a method closes the alive range of a local variable.
2774 case METHODDEF:
2775 // for while loops we want only the body
2776 case WHILELOOP:
2777 return false;
2778 }
2779 return true;
2780 }
2782 }
2784 public class LVTAssignPendingExit extends
2785 Flow.AbstractAssignAnalyzer<LVTAssignPendingExit>.AbstractAssignPendingExit {
2787 LVTAssignPendingExit(JCTree tree, final Bits inits, final Bits uninits) {
2788 super(tree, inits, uninits);
2789 }
2791 @Override
2792 public void resolveJump(JCTree tree) {
2793 lvtInits.at(tree);
2794 super.resolveJump(tree);
2795 }
2796 }
2798 private LVTAssignAnalyzer() {
2799 flow.super();
2800 lvtInits = new LVTBits();
2801 inits = lvtInits;
2802 }
2804 @Override
2805 protected void markDead(JCTree tree) {
2806 lvtInits.at(tree).inclRange(returnadr, nextadr);
2807 super.markDead(tree);
2808 }
2810 @Override
2811 protected void merge(JCTree tree) {
2812 lvtInits.at(tree);
2813 super.merge(tree);
2814 }
2816 boolean isSyntheticOrMandated(Symbol sym) {
2817 return (sym.flags() & (SYNTHETIC | MANDATED)) != 0;
2818 }
2820 @Override
2821 protected boolean trackable(VarSymbol sym) {
2822 if (isSyntheticOrMandated(sym)) {
2823 //fast check to avoid tracking synthetic or mandated variables
2824 return false;
2825 }
2826 return super.trackable(sym);
2827 }
2829 @Override
2830 protected void initParam(JCVariableDecl def) {
2831 if (!isSyntheticOrMandated(def.sym)) {
2832 super.initParam(def);
2833 }
2834 }
2836 @Override
2837 protected void assignToInits(JCTree tree, Bits bits) {
2838 lvtInits.at(tree);
2839 lvtInits.assign(bits);
2840 }
2842 @Override
2843 protected void andSetInits(JCTree tree, Bits bits) {
2844 lvtInits.at(tree);
2845 lvtInits.andSet(bits);
2846 }
2848 @Override
2849 protected void orSetInits(JCTree tree, Bits bits) {
2850 lvtInits.at(tree);
2851 lvtInits.orSet(bits);
2852 }
2854 @Override
2855 protected void exclVarFromInits(JCTree tree, int adr) {
2856 lvtInits.at(tree);
2857 lvtInits.excl(adr);
2858 }
2860 @Override
2861 protected LVTAssignPendingExit createNewPendingExit(JCTree tree, Bits inits, Bits uninits) {
2862 return new LVTAssignPendingExit(tree, inits, uninits);
2863 }
2865 MethodSymbol currentMethod;
2867 @Override
2868 public void visitMethodDef(JCMethodDecl tree) {
2869 if ((tree.sym.flags() & (SYNTHETIC | GENERATEDCONSTR)) != 0
2870 && (tree.sym.flags() & LAMBDA_METHOD) == 0) {
2871 return;
2872 }
2873 if (tree.name.equals(names.clinit)) {
2874 return;
2875 }
2876 boolean enumClass = (tree.sym.owner.flags() & ENUM) != 0;
2877 if (enumClass &&
2878 (tree.name.equals(names.valueOf) ||
2879 tree.name.equals(names.values) ||
2880 tree.name.equals(names.init))) {
2881 return;
2882 }
2883 currentMethod = tree.sym;
2885 super.visitMethodDef(tree);
2886 }
2888 }
2890 }
