001 /*
002 * Copyright 1999-2008 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package com.sun.tools.javac.jvm;
027 import java.util.*;
028
029 import com.sun.tools.javac.util.*;
030 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
031 import com.sun.tools.javac.util.List;
032 import com.sun.tools.javac.code.*;
033 import com.sun.tools.javac.comp.*;
034 import com.sun.tools.javac.tree.*;
035
036 import com.sun.tools.javac.code.Symbol.*;
037 import com.sun.tools.javac.code.Type.*;
038 import com.sun.tools.javac.jvm.Code.*;
039 import com.sun.tools.javac.jvm.Items.*;
040 import com.sun.tools.javac.tree.JCTree.*;
041
042 import static com.sun.tools.javac.code.Flags.*;
043 import static com.sun.tools.javac.code.Kinds.*;
044 import static com.sun.tools.javac.code.TypeTags.*;
045 import static com.sun.tools.javac.jvm.ByteCodes.*;
046 import static com.sun.tools.javac.jvm.CRTFlags.*;
047
048 /** This pass maps flat Java (i.e. without inner classes) to bytecodes.
049 *
050 * <p><b>This is NOT part of any API supported by Sun Microsystems. If
051 * you write code that depends on this, you do so at your own risk.
052 * This code and its internal interfaces are subject to change or
053 * deletion without notice.</b>
054 */
055 public class Gen extends JCTree.Visitor {
056 protected static final Context.Key<Gen> genKey =
057 new Context.Key<Gen>();
058
059 private final Log log;
060 private final Symtab syms;
061 private final Check chk;
062 private final Resolve rs;
063 private final TreeMaker make;
064 private final Names names;
065 private final Target target;
066 private final Type stringBufferType;
067 private final Map<Type,Symbol> stringBufferAppend;
068 private Name accessDollar;
069 private final Types types;
070
071 /** Switch: GJ mode?
072 */
073 private final boolean allowGenerics;
074
075 /** Set when Miranda method stubs are to be generated. */
076 private final boolean generateIproxies;
077
078 /** Format of stackmap tables to be generated. */
079 private final Code.StackMapFormat stackMap;
080
081 /** A type that serves as the expected type for all method expressions.
082 */
083 private final Type methodType;
084
085 public static Gen instance(Context context) {
086 Gen instance = context.get(genKey);
087 if (instance == null)
088 instance = new Gen(context);
089 return instance;
090 }
091
092 protected Gen(Context context) {
093 context.put(genKey, this);
094
095 names = Names.instance(context);
096 log = Log.instance(context);
097 syms = Symtab.instance(context);
098 chk = Check.instance(context);
099 rs = Resolve.instance(context);
100 make = TreeMaker.instance(context);
101 target = Target.instance(context);
102 types = Types.instance(context);
103 methodType = new MethodType(null, null, null, syms.methodClass);
104 allowGenerics = Source.instance(context).allowGenerics();
105 stringBufferType = target.useStringBuilder()
106 ? syms.stringBuilderType
107 : syms.stringBufferType;
108 stringBufferAppend = new HashMap<Type,Symbol>();
109 accessDollar = names.
110 fromString("access" + target.syntheticNameChar());
111
112 Options options = Options.instance(context);
113 lineDebugInfo =
114 options.get("-g:") == null ||
115 options.get("-g:lines") != null;
116 varDebugInfo =
117 options.get("-g:") == null
118 ? options.get("-g") != null
119 : options.get("-g:vars") != null;
120 genCrt = options.get("-Xjcov") != null;
121 debugCode = options.get("debugcode") != null;
122
123 generateIproxies =
124 target.requiresIproxy() ||
125 options.get("miranda") != null;
126
127 if (target.generateStackMapTable()) {
128 // ignore cldc because we cannot have both stackmap formats
129 this.stackMap = StackMapFormat.JSR202;
130 } else {
131 if (target.generateCLDCStackmap()) {
132 this.stackMap = StackMapFormat.CLDC;
133 } else {
134 this.stackMap = StackMapFormat.NONE;
135 }
136 }
137
138 // by default, avoid jsr's for simple finalizers
139 int setjsrlimit = 50;
140 String jsrlimitString = options.get("jsrlimit");
141 if (jsrlimitString != null) {
142 try {
143 setjsrlimit = Integer.parseInt(jsrlimitString);
144 } catch (NumberFormatException ex) {
145 // ignore ill-formed numbers for jsrlimit
146 }
147 }
148 this.jsrlimit = setjsrlimit;
149 this.useJsrLocally = false; // reset in visitTry
150 }
151
152 /** Switches
153 */
154 private final boolean lineDebugInfo;
155 private final boolean varDebugInfo;
156 private final boolean genCrt;
157 private final boolean debugCode;
158
159 /** Default limit of (approximate) size of finalizer to inline.
160 * Zero means always use jsr. 100 or greater means never use
161 * jsr.
162 */
163 private final int jsrlimit;
164
165 /** True if jsr is used.
166 */
167 private boolean useJsrLocally;
168
169 /* Constant pool, reset by genClass.
170 */
171 private Pool pool = new Pool();
172
173 /** Code buffer, set by genMethod.
174 */
175 private Code code;
176
177 /** Items structure, set by genMethod.
178 */
179 private Items items;
180
181 /** Environment for symbol lookup, set by genClass
182 */
183 private Env<AttrContext> attrEnv;
184
185 /** The top level tree.
186 */
187 private JCCompilationUnit toplevel;
188
189 /** The number of code-gen errors in this class.
190 */
191 private int nerrs = 0;
192
193 /** A hash table mapping syntax trees to their ending source positions.
194 */
195 private Map<JCTree, Integer> endPositions;
196
197 /** Generate code to load an integer constant.
198 * @param n The integer to be loaded.
199 */
200 void loadIntConst(int n) {
201 items.makeImmediateItem(syms.intType, n).load();
202 }
203
204 /** The opcode that loads a zero constant of a given type code.
205 * @param tc The given type code (@see ByteCode).
206 */
207 public static int zero(int tc) {
208 switch(tc) {
209 case INTcode: case BYTEcode: case SHORTcode: case CHARcode:
210 return iconst_0;
211 case LONGcode:
212 return lconst_0;
213 case FLOATcode:
214 return fconst_0;
215 case DOUBLEcode:
216 return dconst_0;
217 default:
218 throw new AssertionError("zero");
219 }
220 }
221
222 /** The opcode that loads a one constant of a given type code.
223 * @param tc The given type code (@see ByteCode).
224 */
225 public static int one(int tc) {
226 return zero(tc) + 1;
227 }
228
229 /** Generate code to load -1 of the given type code (either int or long).
230 * @param tc The given type code (@see ByteCode).
231 */
232 void emitMinusOne(int tc) {
233 if (tc == LONGcode) {
234 items.makeImmediateItem(syms.longType, new Long(-1)).load();
235 } else {
236 code.emitop0(iconst_m1);
237 }
238 }
239
240 /** Construct a symbol to reflect the qualifying type that should
241 * appear in the byte code as per JLS 13.1.
242 *
243 * For target >= 1.2: Clone a method with the qualifier as owner (except
244 * for those cases where we need to work around VM bugs).
245 *
246 * For target <= 1.1: If qualified variable or method is defined in a
247 * non-accessible class, clone it with the qualifier class as owner.
248 *
249 * @param sym The accessed symbol
250 * @param site The qualifier's type.
251 */
252 Symbol binaryQualifier(Symbol sym, Type site) {
253
254 if (site.tag == ARRAY) {
255 if (sym == syms.lengthVar ||
256 sym.owner != syms.arrayClass)
257 return sym;
258 // array clone can be qualified by the array type in later targets
259 Symbol qualifier = target.arrayBinaryCompatibility()
260 ? new ClassSymbol(Flags.PUBLIC, site.tsym.name,
261 site, syms.noSymbol)
262 : syms.objectType.tsym;
263 return sym.clone(qualifier);
264 }
265
266 if (sym.owner == site.tsym ||
267 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) {
268 return sym;
269 }
270 if (!target.obeyBinaryCompatibility())
271 return rs.isAccessible(attrEnv, (TypeSymbol)sym.owner)
272 ? sym
273 : sym.clone(site.tsym);
274
275 if (!target.interfaceFieldsBinaryCompatibility()) {
276 if ((sym.owner.flags() & INTERFACE) != 0 && sym.kind == VAR)
277 return sym;
278 }
279
280 // leave alone methods inherited from Object
281 // JLS2 13.1.
282 if (sym.owner == syms.objectType.tsym)
283 return sym;
284
285 if (!target.interfaceObjectOverridesBinaryCompatibility()) {
286 if ((sym.owner.flags() & INTERFACE) != 0 &&
287 syms.objectType.tsym.members().lookup(sym.name).scope != null)
288 return sym;
289 }
290
291 return sym.clone(site.tsym);
292 }
293
294 /** Insert a reference to given type in the constant pool,
295 * checking for an array with too many dimensions;
296 * return the reference's index.
297 * @param type The type for which a reference is inserted.
298 */
299 int makeRef(DiagnosticPosition pos, Type type) {
300 checkDimension(pos, type);
301 return pool.put(type.tag == CLASS ? (Object)type.tsym : (Object)type);
302 }
303
304 /** Check if the given type is an array with too many dimensions.
305 */
306 private void checkDimension(DiagnosticPosition pos, Type t) {
307 switch (t.tag) {
308 case METHOD:
309 checkDimension(pos, t.getReturnType());
310 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail)
311 checkDimension(pos, args.head);
312 break;
313 case ARRAY:
314 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) {
315 log.error(pos, "limit.dimensions");
316 nerrs++;
317 }
318 break;
319 default:
320 break;
321 }
322 }
323
324 /** Create a tempory variable.
325 * @param type The variable's type.
326 */
327 LocalItem makeTemp(Type type) {
328 VarSymbol v = new VarSymbol(Flags.SYNTHETIC,
329 names.empty,
330 type,
331 env.enclMethod.sym);
332 code.newLocal(v);
333 return items.makeLocalItem(v);
334 }
335
336 /** Generate code to call a non-private method or constructor.
337 * @param pos Position to be used for error reporting.
338 * @param site The type of which the method is a member.
339 * @param name The method's name.
340 * @param argtypes The method's argument types.
341 * @param isStatic A flag that indicates whether we call a
342 * static or instance method.
343 */
344 void callMethod(DiagnosticPosition pos,
345 Type site, Name name, List<Type> argtypes,
346 boolean isStatic) {
347 Symbol msym = rs.
348 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null);
349 if (isStatic) items.makeStaticItem(msym).invoke();
350 else items.makeMemberItem(msym, name == names.init).invoke();
351 }
352
353 /** Is the given method definition an access method
354 * resulting from a qualified super? This is signified by an odd
355 * access code.
356 */
357 private boolean isAccessSuper(JCMethodDecl enclMethod) {
358 return
359 (enclMethod.mods.flags & SYNTHETIC) != 0 &&
360 isOddAccessName(enclMethod.name);
361 }
362
363 /** Does given name start with "access$" and end in an odd digit?
364 */
365 private boolean isOddAccessName(Name name) {
366 return
367 name.startsWith(accessDollar) &&
368 (name.getByteAt(name.getByteLength() - 1) & 1) == 1;
369 }
370
371 /* ************************************************************************
372 * Non-local exits
373 *************************************************************************/
374
375 /** Generate code to invoke the finalizer associated with given
376 * environment.
377 * Any calls to finalizers are appended to the environments `cont' chain.
378 * Mark beginning of gap in catch all range for finalizer.
379 */
380 void genFinalizer(Env<GenContext> env) {
381 if (code.isAlive() && env.info.finalize != null)
382 env.info.finalize.gen();
383 }
384
385 /** Generate code to call all finalizers of structures aborted by
386 * a non-local
387 * exit. Return target environment of the non-local exit.
388 * @param target The tree representing the structure that's aborted
389 * @param env The environment current at the non-local exit.
390 */
391 Env<GenContext> unwind(JCTree target, Env<GenContext> env) {
392 Env<GenContext> env1 = env;
393 while (true) {
394 genFinalizer(env1);
395 if (env1.tree == target) break;
396 env1 = env1.next;
397 }
398 return env1;
399 }
400
401 /** Mark end of gap in catch-all range for finalizer.
402 * @param env the environment which might contain the finalizer
403 * (if it does, env.info.gaps != null).
404 */
405 void endFinalizerGap(Env<GenContext> env) {
406 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1)
407 env.info.gaps.append(code.curPc());
408 }
409
410 /** Mark end of all gaps in catch-all ranges for finalizers of environments
411 * lying between, and including to two environments.
412 * @param from the most deeply nested environment to mark
413 * @param to the least deeply nested environment to mark
414 */
415 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) {
416 Env<GenContext> last = null;
417 while (last != to) {
418 endFinalizerGap(from);
419 last = from;
420 from = from.next;
421 }
422 }
423
424 /** Do any of the structures aborted by a non-local exit have
425 * finalizers that require an empty stack?
426 * @param target The tree representing the structure that's aborted
427 * @param env The environment current at the non-local exit.
428 */
429 boolean hasFinally(JCTree target, Env<GenContext> env) {
430 while (env.tree != target) {
431 if (env.tree.getTag() == JCTree.TRY && env.info.finalize.hasFinalizer())
432 return true;
433 env = env.next;
434 }
435 return false;
436 }
437
438 /* ************************************************************************
439 * Normalizing class-members.
440 *************************************************************************/
441
442 /** Distribute member initializer code into constructors and <clinit>
443 * method.
444 * @param defs The list of class member declarations.
445 * @param c The enclosing class.
446 */
447 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) {
448 ListBuffer<JCStatement> initCode = new ListBuffer<JCStatement>();
449 ListBuffer<JCStatement> clinitCode = new ListBuffer<JCStatement>();
450 ListBuffer<JCTree> methodDefs = new ListBuffer<JCTree>();
451 // Sort definitions into three listbuffers:
452 // - initCode for instance initializers
453 // - clinitCode for class initializers
454 // - methodDefs for method definitions
455 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
456 JCTree def = l.head;
457 switch (def.getTag()) {
458 case JCTree.BLOCK:
459 JCBlock block = (JCBlock)def;
460 if ((block.flags & STATIC) != 0)
461 clinitCode.append(block);
462 else
463 initCode.append(block);
464 break;
465 case JCTree.METHODDEF:
466 methodDefs.append(def);
467 break;
468 case JCTree.VARDEF:
469 JCVariableDecl vdef = (JCVariableDecl) def;
470 VarSymbol sym = vdef.sym;
471 checkDimension(vdef.pos(), sym.type);
472 if (vdef.init != null) {
473 if ((sym.flags() & STATIC) == 0) {
474 // Always initialize instance variables.
475 JCStatement init = make.at(vdef.pos()).
476 Assignment(sym, vdef.init);
477 initCode.append(init);
478 if (endPositions != null) {
479 Integer endPos = endPositions.remove(vdef);
480 if (endPos != null) endPositions.put(init, endPos);
481 }
482 } else if (sym.getConstValue() == null) {
483 // Initialize class (static) variables only if
484 // they are not compile-time constants.
485 JCStatement init = make.at(vdef.pos).
486 Assignment(sym, vdef.init);
487 clinitCode.append(init);
488 if (endPositions != null) {
489 Integer endPos = endPositions.remove(vdef);
490 if (endPos != null) endPositions.put(init, endPos);
491 }
492 } else {
493 checkStringConstant(vdef.init.pos(), sym.getConstValue());
494 }
495 }
496 break;
497 default:
498 assert false;
499 }
500 }
501 // Insert any instance initializers into all constructors.
502 if (initCode.length() != 0) {
503 List<JCStatement> inits = initCode.toList();
504 for (JCTree t : methodDefs) {
505 normalizeMethod((JCMethodDecl)t, inits);
506 }
507 }
508 // If there are class initializers, create a <clinit> method
509 // that contains them as its body.
510 if (clinitCode.length() != 0) {
511 MethodSymbol clinit = new MethodSymbol(
512 STATIC, names.clinit,
513 new MethodType(
514 List.<Type>nil(), syms.voidType,
515 List.<Type>nil(), syms.methodClass),
516 c);
517 c.members().enter(clinit);
518 List<JCStatement> clinitStats = clinitCode.toList();
519 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
520 block.endpos = TreeInfo.endPos(clinitStats.last());
521 methodDefs.append(make.MethodDef(clinit, block));
522 }
523 // Return all method definitions.
524 return methodDefs.toList();
525 }
526
527 /** Check a constant value and report if it is a string that is
528 * too large.
529 */
530 private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
531 if (nerrs != 0 || // only complain about a long string once
532 constValue == null ||
533 !(constValue instanceof String) ||
534 ((String)constValue).length() < Pool.MAX_STRING_LENGTH)
535 return;
536 log.error(pos, "limit.string");
537 nerrs++;
538 }
539
540 /** Insert instance initializer code into initial constructor.
541 * @param md The tree potentially representing a
542 * constructor's definition.
543 * @param initCode The list of instance initializer statements.
544 */
545 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode) {
546 if (md.name == names.init && TreeInfo.isInitialConstructor(md)) {
547 // We are seeing a constructor that does not call another
548 // constructor of the same class.
549 List<JCStatement> stats = md.body.stats;
550 ListBuffer<JCStatement> newstats = new ListBuffer<JCStatement>();
551
552 if (stats.nonEmpty()) {
553 // Copy initializers of synthetic variables generated in
554 // the translation of inner classes.
555 while (TreeInfo.isSyntheticInit(stats.head)) {
556 newstats.append(stats.head);
557 stats = stats.tail;
558 }
559 // Copy superclass constructor call
560 newstats.append(stats.head);
561 stats = stats.tail;
562 // Copy remaining synthetic initializers.
563 while (stats.nonEmpty() &&
564 TreeInfo.isSyntheticInit(stats.head)) {
565 newstats.append(stats.head);
566 stats = stats.tail;
567 }
568 // Now insert the initializer code.
569 newstats.appendList(initCode);
570 // And copy all remaining statements.
571 while (stats.nonEmpty()) {
572 newstats.append(stats.head);
573 stats = stats.tail;
574 }
575 }
576 md.body.stats = newstats.toList();
577 if (md.body.endpos == Position.NOPOS)
578 md.body.endpos = TreeInfo.endPos(md.body.stats.last());
579 }
580 }
581
582 /* ********************************************************************
583 * Adding miranda methods
584 *********************************************************************/
585
586 /** Add abstract methods for all methods defined in one of
587 * the interfaces of a given class,
588 * provided they are not already implemented in the class.
589 *
590 * @param c The class whose interfaces are searched for methods
591 * for which Miranda methods should be added.
592 */
593 void implementInterfaceMethods(ClassSymbol c) {
594 implementInterfaceMethods(c, c);
595 }
596
597 /** Add abstract methods for all methods defined in one of
598 * the interfaces of a given class,
599 * provided they are not already implemented in the class.
600 *
601 * @param c The class whose interfaces are searched for methods
602 * for which Miranda methods should be added.
603 * @param site The class in which a definition may be needed.
604 */
605 void implementInterfaceMethods(ClassSymbol c, ClassSymbol site) {
606 for (List<Type> l = types.interfaces(c.type); l.nonEmpty(); l = l.tail) {
607 ClassSymbol i = (ClassSymbol)l.head.tsym;
608 for (Scope.Entry e = i.members().elems;
609 e != null;
610 e = e.sibling)
611 {
612 if (e.sym.kind == MTH && (e.sym.flags() & STATIC) == 0)
613 {
614 MethodSymbol absMeth = (MethodSymbol)e.sym;
615 MethodSymbol implMeth = absMeth.binaryImplementation(site, types);
616 if (implMeth == null)
617 addAbstractMethod(site, absMeth);
618 else if ((implMeth.flags() & IPROXY) != 0)
619 adjustAbstractMethod(site, implMeth, absMeth);
620 }
621 }
622 implementInterfaceMethods(i, site);
623 }
624 }
625
626 /** Add an abstract methods to a class
627 * which implicitly implements a method defined in some interface
628 * implemented by the class. These methods are called "Miranda methods".
629 * Enter the newly created method into its enclosing class scope.
630 * Note that it is not entered into the class tree, as the emitter
631 * doesn't need to see it there to emit an abstract method.
632 *
633 * @param c The class to which the Miranda method is added.
634 * @param m The interface method symbol for which a Miranda method
635 * is added.
636 */
637 private void addAbstractMethod(ClassSymbol c,
638 MethodSymbol m) {
639 MethodSymbol absMeth = new MethodSymbol(
640 m.flags() | IPROXY | SYNTHETIC, m.name,
641 m.type, // was c.type.memberType(m), but now only !generics supported
642 c);
643 c.members().enter(absMeth); // add to symbol table
644 }
645
646 private void adjustAbstractMethod(ClassSymbol c,
647 MethodSymbol pm,
648 MethodSymbol im) {
649 MethodType pmt = (MethodType)pm.type;
650 Type imt = types.memberType(c.type, im);
651 pmt.thrown = chk.intersect(pmt.getThrownTypes(), imt.getThrownTypes());
652 }
653
654 /* ************************************************************************
655 * Traversal methods
656 *************************************************************************/
657
658 /** Visitor argument: The current environment.
659 */
660 Env<GenContext> env;
661
662 /** Visitor argument: The expected type (prototype).
663 */
664 Type pt;
665
666 /** Visitor result: The item representing the computed value.
667 */
668 Item result;
669
670 /** Visitor method: generate code for a definition, catching and reporting
671 * any completion failures.
672 * @param tree The definition to be visited.
673 * @param env The environment current at the definition.
674 */
675 public void genDef(JCTree tree, Env<GenContext> env) {
676 Env<GenContext> prevEnv = this.env;
677 try {
678 this.env = env;
679 tree.accept(this);
680 } catch (CompletionFailure ex) {
681 chk.completionError(tree.pos(), ex);
682 } finally {
683 this.env = prevEnv;
684 }
685 }
686
687 /** Derived visitor method: check whether CharacterRangeTable
688 * should be emitted, if so, put a new entry into CRTable
689 * and call method to generate bytecode.
690 * If not, just call method to generate bytecode.
691 * @see #genStat(Tree, Env)
692 *
693 * @param tree The tree to be visited.
694 * @param env The environment to use.
695 * @param crtFlags The CharacterRangeTable flags
696 * indicating type of the entry.
697 */
698 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
699 if (!genCrt) {
700 genStat(tree, env);
701 return;
702 }
703 int startpc = code.curPc();
704 genStat(tree, env);
705 if (tree.getTag() == JCTree.BLOCK) crtFlags |= CRT_BLOCK;
706 code.crt.put(tree, crtFlags, startpc, code.curPc());
707 }
708
709 /** Derived visitor method: generate code for a statement.
710 */
711 public void genStat(JCTree tree, Env<GenContext> env) {
712 if (code.isAlive()) {
713 code.statBegin(tree.pos);
714 genDef(tree, env);
715 } else if (env.info.isSwitch && tree.getTag() == JCTree.VARDEF) {
716 // variables whose declarations are in a switch
717 // can be used even if the decl is unreachable.
718 code.newLocal(((JCVariableDecl) tree).sym);
719 }
720 }
721
722 /** Derived visitor method: check whether CharacterRangeTable
723 * should be emitted, if so, put a new entry into CRTable
724 * and call method to generate bytecode.
725 * If not, just call method to generate bytecode.
726 * @see #genStats(List, Env)
727 *
728 * @param trees The list of trees to be visited.
729 * @param env The environment to use.
730 * @param crtFlags The CharacterRangeTable flags
731 * indicating type of the entry.
732 */
733 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
734 if (!genCrt) {
735 genStats(trees, env);
736 return;
737 }
738 if (trees.length() == 1) { // mark one statement with the flags
739 genStat(trees.head, env, crtFlags | CRT_STATEMENT);
740 } else {
741 int startpc = code.curPc();
742 genStats(trees, env);
743 code.crt.put(trees, crtFlags, startpc, code.curPc());
744 }
745 }
746
747 /** Derived visitor method: generate code for a list of statements.
748 */
749 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) {
750 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
751 genStat(l.head, env, CRT_STATEMENT);
752 }
753
754 /** Derived visitor method: check whether CharacterRangeTable
755 * should be emitted, if so, put a new entry into CRTable
756 * and call method to generate bytecode.
757 * If not, just call method to generate bytecode.
758 * @see #genCond(Tree,boolean)
759 *
760 * @param tree The tree to be visited.
761 * @param crtFlags The CharacterRangeTable flags
762 * indicating type of the entry.
763 */
764 public CondItem genCond(JCTree tree, int crtFlags) {
765 if (!genCrt) return genCond(tree, false);
766 int startpc = code.curPc();
767 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
768 code.crt.put(tree, crtFlags, startpc, code.curPc());
769 return item;
770 }
771
772 /** Derived visitor method: generate code for a boolean
773 * expression in a control-flow context.
774 * @param _tree The expression to be visited.
775 * @param markBranches The flag to indicate that the condition is
776 * a flow controller so produced conditions
777 * should contain a proper tree to generate
778 * CharacterRangeTable branches for them.
779 */
780 public CondItem genCond(JCTree _tree, boolean markBranches) {
781 JCTree inner_tree = TreeInfo.skipParens(_tree);
782 if (inner_tree.getTag() == JCTree.CONDEXPR) {
783 JCConditional tree = (JCConditional)inner_tree;
784 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
785 if (cond.isTrue()) {
786 code.resolve(cond.trueJumps);
787 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
788 if (markBranches) result.tree = tree.truepart;
789 return result;
790 }
791 if (cond.isFalse()) {
792 code.resolve(cond.falseJumps);
793 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
794 if (markBranches) result.tree = tree.falsepart;
795 return result;
796 }
797 Chain secondJumps = cond.jumpFalse();
798 code.resolve(cond.trueJumps);
799 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
800 if (markBranches) first.tree = tree.truepart;
801 Chain falseJumps = first.jumpFalse();
802 code.resolve(first.trueJumps);
803 Chain trueJumps = code.branch(goto_);
804 code.resolve(secondJumps);
805 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
806 CondItem result = items.makeCondItem(second.opcode,
807 code.mergeChains(trueJumps, second.trueJumps),
808 code.mergeChains(falseJumps, second.falseJumps));
809 if (markBranches) result.tree = tree.falsepart;
810 return result;
811 } else {
812 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
813 if (markBranches) result.tree = _tree;
814 return result;
815 }
816 }
817
818 /** Visitor method: generate code for an expression, catching and reporting
819 * any completion failures.
820 * @param tree The expression to be visited.
821 * @param pt The expression's expected type (proto-type).
822 */
823 public Item genExpr(JCTree tree, Type pt) {
824 Type prevPt = this.pt;
825 try {
826 if (tree.type.constValue() != null) {
827 // Short circuit any expressions which are constants
828 checkStringConstant(tree.pos(), tree.type.constValue());
829 result = items.makeImmediateItem(tree.type, tree.type.constValue());
830 } else {
831 this.pt = pt;
832 tree.accept(this);
833 }
834 return result.coerce(pt);
835 } catch (CompletionFailure ex) {
836 chk.completionError(tree.pos(), ex);
837 code.state.stacksize = 1;
838 return items.makeStackItem(pt);
839 } finally {
840 this.pt = prevPt;
841 }
842 }
843
844 /** Derived visitor method: generate code for a list of method arguments.
845 * @param trees The argument expressions to be visited.
846 * @param pts The expression's expected types (i.e. the formal parameter
847 * types of the invoked method).
848 */
849 public void genArgs(List<JCExpression> trees, List<Type> pts) {
850 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
851 genExpr(l.head, pts.head).load();
852 pts = pts.tail;
853 }
854 // require lists be of same length
855 assert pts.isEmpty();
856 }
857
858 /* ************************************************************************
859 * Visitor methods for statements and definitions
860 *************************************************************************/
861
862 /** Thrown when the byte code size exceeds limit.
863 */
864 public static class CodeSizeOverflow extends RuntimeException {
865 private static final long serialVersionUID = 0;
866 public CodeSizeOverflow() {}
867 }
868
869 public void visitMethodDef(JCMethodDecl tree) {
870 // Create a new local environment that points pack at method
871 // definition.
872 Env<GenContext> localEnv = env.dup(tree);
873 localEnv.enclMethod = tree;
874
875 // The expected type of every return statement in this method
876 // is the method's return type.
877 this.pt = tree.sym.erasure(types).getReturnType();
878
879 checkDimension(tree.pos(), tree.sym.erasure(types));
880 genMethod(tree, localEnv, false);
881 }
882 //where
883 /** Generate code for a method.
884 * @param tree The tree representing the method definition.
885 * @param env The environment current for the method body.
886 * @param fatcode A flag that indicates whether all jumps are
887 * within 32K. We first invoke this method under
888 * the assumption that fatcode == false, i.e. all
889 * jumps are within 32K. If this fails, fatcode
890 * is set to true and we try again.
891 */
892 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
893 MethodSymbol meth = tree.sym;
894 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
895 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) +
896 (((tree.mods.flags & STATIC) == 0 || meth.isConstructor()) ? 1 : 0) >
897 ClassFile.MAX_PARAMETERS) {
898 log.error(tree.pos(), "limit.parameters");
899 nerrs++;
900 }
901
902 else if (tree.body != null) {
903 // Create a new code structure and initialize it.
904 int startpcCrt = initCode(tree, env, fatcode);
905
906 try {
907 genStat(tree.body, env);
908 } catch (CodeSizeOverflow e) {
909 // Failed due to code limit, try again with jsr/ret
910 startpcCrt = initCode(tree, env, fatcode);
911 genStat(tree.body, env);
912 }
913
914 if (code.state.stacksize != 0) {
915 log.error(tree.body.pos(), "stack.sim.error", tree);
916 throw new AssertionError();
917 }
918
919 // If last statement could complete normally, insert a
920 // return at the end.
921 if (code.isAlive()) {
922 code.statBegin(TreeInfo.endPos(tree.body));
923 if (env.enclMethod == null ||
924 env.enclMethod.sym.type.getReturnType().tag == VOID) {
925 code.emitop0(return_);
926 } else {
927 // sometime dead code seems alive (4415991);
928 // generate a small loop instead
929 int startpc = code.entryPoint();
930 CondItem c = items.makeCondItem(goto_);
931 code.resolve(c.jumpTrue(), startpc);
932 }
933 }
934 if (genCrt)
935 code.crt.put(tree.body,
936 CRT_BLOCK,
937 startpcCrt,
938 code.curPc());
939
940 // End the scope of all local variables in variable info.
941 code.endScopes(0);
942
943 // If we exceeded limits, panic
944 if (code.checkLimits(tree.pos(), log)) {
945 nerrs++;
946 return;
947 }
948
949 // If we generated short code but got a long jump, do it again
950 // with fatCode = true.
951 if (!fatcode && code.fatcode) genMethod(tree, env, true);
952
953 // Clean up
954 if(stackMap == StackMapFormat.JSR202) {
955 code.lastFrame = null;
956 code.frameBeforeLast = null;
957 }
958 }
959 }
960
961 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
962 MethodSymbol meth = tree.sym;
963
964 // Create a new code structure.
965 meth.code = code = new Code(meth,
966 fatcode,
967 lineDebugInfo ? toplevel.lineMap : null,
968 varDebugInfo,
969 stackMap,
970 debugCode,
971 genCrt ? new CRTable(tree, env.toplevel.endPositions)
972 : null,
973 syms,
974 types,
975 pool);
976 items = new Items(pool, code, syms, types);
977 if (code.debugCode)
978 System.err.println(meth + " for body " + tree);
979
980 // If method is not static, create a new local variable address
981 // for `this'.
982 if ((tree.mods.flags & STATIC) == 0) {
983 Type selfType = meth.owner.type;
984 if (meth.isConstructor() && selfType != syms.objectType)
985 selfType = UninitializedType.uninitializedThis(selfType);
986 code.setDefined(
987 code.newLocal(
988 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
989 }
990
991 // Mark all parameters as defined from the beginning of
992 // the method.
993 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
994 checkDimension(l.head.pos(), l.head.sym.type);
995 code.setDefined(code.newLocal(l.head.sym));
996 }
997
998 // Get ready to generate code for method body.
999 int startpcCrt = genCrt ? code.curPc() : 0;
1000 code.entryPoint();
1001
1002 // Suppress initial stackmap
1003 code.pendingStackMap = false;
1004
1005 return startpcCrt;
1006 }
1007
1008 public void visitVarDef(JCVariableDecl tree) {
1009 VarSymbol v = tree.sym;
1010 code.newLocal(v);
1011 if (tree.init != null) {
1012 checkStringConstant(tree.init.pos(), v.getConstValue());
1013 if (v.getConstValue() == null || varDebugInfo) {
1014 genExpr(tree.init, v.erasure(types)).load();
1015 items.makeLocalItem(v).store();
1016 }
1017 }
1018 checkDimension(tree.pos(), v.type);
1019 }
1020
1021 public void visitSkip(JCSkip tree) {
1022 }
1023
1024 public void visitBlock(JCBlock tree) {
1025 int limit = code.nextreg;
1026 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1027 genStats(tree.stats, localEnv);
1028 // End the scope of all block-local variables in variable info.
1029 if (env.tree.getTag() != JCTree.METHODDEF) {
1030 code.statBegin(tree.endpos);
1031 code.endScopes(limit);
1032 code.pendingStatPos = Position.NOPOS;
1033 }
1034 }
1035
1036 public void visitDoLoop(JCDoWhileLoop tree) {
1037 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), false);
1038 }
1039
1040 public void visitWhileLoop(JCWhileLoop tree) {
1041 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), true);
1042 }
1043
1044 public void visitForLoop(JCForLoop tree) {
1045 int limit = code.nextreg;
1046 genStats(tree.init, env);
1047 genLoop(tree, tree.body, tree.cond, tree.step, true);
1048 code.endScopes(limit);
1049 }
1050 //where
1051 /** Generate code for a loop.
1052 * @param loop The tree representing the loop.
1053 * @param body The loop's body.
1054 * @param cond The loop's controling condition.
1055 * @param step "Step" statements to be inserted at end of
1056 * each iteration.
1057 * @param testFirst True if the loop test belongs before the body.
1058 */
1059 private void genLoop(JCStatement loop,
1060 JCStatement body,
1061 JCExpression cond,
1062 List<JCExpressionStatement> step,
1063 boolean testFirst) {
1064 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1065 int startpc = code.entryPoint();
1066 if (testFirst) {
1067 CondItem c;
1068 if (cond != null) {
1069 code.statBegin(cond.pos);
1070 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1071 } else {
1072 c = items.makeCondItem(goto_);
1073 }
1074 Chain loopDone = c.jumpFalse();
1075 code.resolve(c.trueJumps);
1076 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1077 code.resolve(loopEnv.info.cont);
1078 genStats(step, loopEnv);
1079 code.resolve(code.branch(goto_), startpc);
1080 code.resolve(loopDone);
1081 } else {
1082 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1083 code.resolve(loopEnv.info.cont);
1084 genStats(step, loopEnv);
1085 CondItem c;
1086 if (cond != null) {
1087 code.statBegin(cond.pos);
1088 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1089 } else {
1090 c = items.makeCondItem(goto_);
1091 }
1092 code.resolve(c.jumpTrue(), startpc);
1093 code.resolve(c.falseJumps);
1094 }
1095 code.resolve(loopEnv.info.exit);
1096 }
1097
1098 public void visitForeachLoop(JCEnhancedForLoop tree) {
1099 throw new AssertionError(); // should have been removed by Lower.
1100 }
1101
1102 public void visitLabelled(JCLabeledStatement tree) {
1103 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1104 genStat(tree.body, localEnv, CRT_STATEMENT);
1105 code.resolve(localEnv.info.exit);
1106 }
1107
1108 public void visitSwitch(JCSwitch tree) {
1109 int limit = code.nextreg;
1110 assert tree.selector.type.tag != CLASS;
1111 int startpcCrt = genCrt ? code.curPc() : 0;
1112 Item sel = genExpr(tree.selector, syms.intType);
1113 List<JCCase> cases = tree.cases;
1114 if (cases.isEmpty()) {
1115 // We are seeing: switch <sel> {}
1116 sel.load().drop();
1117 if (genCrt)
1118 code.crt.put(TreeInfo.skipParens(tree.selector),
1119 CRT_FLOW_CONTROLLER, startpcCrt, code.curPc());
1120 } else {
1121 // We are seeing a nonempty switch.
1122 sel.load();
1123 if (genCrt)
1124 code.crt.put(TreeInfo.skipParens(tree.selector),
1125 CRT_FLOW_CONTROLLER, startpcCrt, code.curPc());
1126 Env<GenContext> switchEnv = env.dup(tree, new GenContext());
1127 switchEnv.info.isSwitch = true;
1128
1129 // Compute number of labels and minimum and maximum label values.
1130 // For each case, store its label in an array.
1131 int lo = Integer.MAX_VALUE; // minimum label.
1132 int hi = Integer.MIN_VALUE; // maximum label.
1133 int nlabels = 0; // number of labels.
1134
1135 int[] labels = new int[cases.length()]; // the label array.
1136 int defaultIndex = -1; // the index of the default clause.
1137
1138 List<JCCase> l = cases;
1139 for (int i = 0; i < labels.length; i++) {
1140 if (l.head.pat != null) {
1141 int val = ((Number)l.head.pat.type.constValue()).intValue();
1142 labels[i] = val;
1143 if (val < lo) lo = val;
1144 if (hi < val) hi = val;
1145 nlabels++;
1146 } else {
1147 assert defaultIndex == -1;
1148 defaultIndex = i;
1149 }
1150 l = l.tail;
1151 }
1152
1153 // Determine whether to issue a tableswitch or a lookupswitch
1154 // instruction.
1155 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1156 long table_time_cost = 3; // comparisons
1157 long lookup_space_cost = 3 + 2 * (long) nlabels;
1158 long lookup_time_cost = nlabels;
1159 int opcode =
1160 nlabels > 0 &&
1161 table_space_cost + 3 * table_time_cost <=
1162 lookup_space_cost + 3 * lookup_time_cost
1163 ?
1164 tableswitch : lookupswitch;
1165
1166 int startpc = code.curPc(); // the position of the selector operation
1167 code.emitop0(opcode);
1168 code.align(4);
1169 int tableBase = code.curPc(); // the start of the jump table
1170 int[] offsets = null; // a table of offsets for a lookupswitch
1171 code.emit4(-1); // leave space for default offset
1172 if (opcode == tableswitch) {
1173 code.emit4(lo); // minimum label
1174 code.emit4(hi); // maximum label
1175 for (long i = lo; i <= hi; i++) { // leave space for jump table
1176 code.emit4(-1);
1177 }
1178 } else {
1179 code.emit4(nlabels); // number of labels
1180 for (int i = 0; i < nlabels; i++) {
1181 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1182 }
1183 offsets = new int[labels.length];
1184 }
1185 Code.State stateSwitch = code.state.dup();
1186 code.markDead();
1187
1188 // For each case do:
1189 l = cases;
1190 for (int i = 0; i < labels.length; i++) {
1191 JCCase c = l.head;
1192 l = l.tail;
1193
1194 int pc = code.entryPoint(stateSwitch);
1195 // Insert offset directly into code or else into the
1196 // offsets table.
1197 if (i != defaultIndex) {
1198 if (opcode == tableswitch) {
1199 code.put4(
1200 tableBase + 4 * (labels[i] - lo + 3),
1201 pc - startpc);
1202 } else {
1203 offsets[i] = pc - startpc;
1204 }
1205 } else {
1206 code.put4(tableBase, pc - startpc);
1207 }
1208
1209 // Generate code for the statements in this case.
1210 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1211 }
1212
1213 // Resolve all breaks.
1214 code.resolve(switchEnv.info.exit);
1215
1216 // If we have not set the default offset, we do so now.
1217 if (code.get4(tableBase) == -1) {
1218 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1219 }
1220
1221 if (opcode == tableswitch) {
1222 // Let any unfilled slots point to the default case.
1223 int defaultOffset = code.get4(tableBase);
1224 for (long i = lo; i <= hi; i++) {
1225 int t = (int)(tableBase + 4 * (i - lo + 3));
1226 if (code.get4(t) == -1)
1227 code.put4(t, defaultOffset);
1228 }
1229 } else {
1230 // Sort non-default offsets and copy into lookup table.
1231 if (defaultIndex >= 0)
1232 for (int i = defaultIndex; i < labels.length - 1; i++) {
1233 labels[i] = labels[i+1];
1234 offsets[i] = offsets[i+1];
1235 }
1236 if (nlabels > 0)
1237 qsort2(labels, offsets, 0, nlabels - 1);
1238 for (int i = 0; i < nlabels; i++) {
1239 int caseidx = tableBase + 8 * (i + 1);
1240 code.put4(caseidx, labels[i]);
1241 code.put4(caseidx + 4, offsets[i]);
1242 }
1243 }
1244 }
1245 code.endScopes(limit);
1246 }
1247 //where
1248 /** Sort (int) arrays of keys and values
1249 */
1250 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1251 int i = lo;
1252 int j = hi;
1253 int pivot = keys[(i+j)/2];
1254 do {
1255 while (keys[i] < pivot) i++;
1256 while (pivot < keys[j]) j--;
1257 if (i <= j) {
1258 int temp1 = keys[i];
1259 keys[i] = keys[j];
1260 keys[j] = temp1;
1261 int temp2 = values[i];
1262 values[i] = values[j];
1263 values[j] = temp2;
1264 i++;
1265 j--;
1266 }
1267 } while (i <= j);
1268 if (lo < j) qsort2(keys, values, lo, j);
1269 if (i < hi) qsort2(keys, values, i, hi);
1270 }
1271
1272 public void visitSynchronized(JCSynchronized tree) {
1273 int limit = code.nextreg;
1274 // Generate code to evaluate lock and save in temporary variable.
1275 final LocalItem lockVar = makeTemp(syms.objectType);
1276 genExpr(tree.lock, tree.lock.type).load().duplicate();
1277 lockVar.store();
1278
1279 // Generate code to enter monitor.
1280 code.emitop0(monitorenter);
1281 code.state.lock(lockVar.reg);
1282
1283 // Generate code for a try statement with given body, no catch clauses
1284 // in a new environment with the "exit-monitor" operation as finalizer.
1285 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1286 syncEnv.info.finalize = new GenFinalizer() {
1287 void gen() {
1288 genLast();
1289 assert syncEnv.info.gaps.length() % 2 == 0;
1290 syncEnv.info.gaps.append(code.curPc());
1291 }
1292 void genLast() {
1293 if (code.isAlive()) {
1294 lockVar.load();
1295 code.emitop0(monitorexit);
1296 code.state.unlock(lockVar.reg);
1297 }
1298 }
1299 };
1300 syncEnv.info.gaps = new ListBuffer<Integer>();
1301 genTry(tree.body, List.<JCCatch>nil(), syncEnv);
1302 code.endScopes(limit);
1303 }
1304
1305 public void visitTry(final JCTry tree) {
1306 // Generate code for a try statement with given body and catch clauses,
1307 // in a new environment which calls the finally block if there is one.
1308 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1309 final Env<GenContext> oldEnv = env;
1310 if (!useJsrLocally) {
1311 useJsrLocally =
1312 (stackMap == StackMapFormat.NONE) &&
1313 (jsrlimit <= 0 ||
1314 jsrlimit < 100 &&
1315 estimateCodeComplexity(tree.finalizer)>jsrlimit);
1316 }
1317 tryEnv.info.finalize = new GenFinalizer() {
1318 void gen() {
1319 if (useJsrLocally) {
1320 if (tree.finalizer != null) {
1321 Code.State jsrState = code.state.dup();
1322 jsrState.push(code.jsrReturnValue);
1323 tryEnv.info.cont =
1324 new Chain(code.emitJump(jsr),
1325 tryEnv.info.cont,
1326 jsrState);
1327 }
1328 assert tryEnv.info.gaps.length() % 2 == 0;
1329 tryEnv.info.gaps.append(code.curPc());
1330 } else {
1331 assert tryEnv.info.gaps.length() % 2 == 0;
1332 tryEnv.info.gaps.append(code.curPc());
1333 genLast();
1334 }
1335 }
1336 void genLast() {
1337 if (tree.finalizer != null)
1338 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1339 }
1340 boolean hasFinalizer() {
1341 return tree.finalizer != null;
1342 }
1343 };
1344 tryEnv.info.gaps = new ListBuffer<Integer>();
1345 genTry(tree.body, tree.catchers, tryEnv);
1346 }
1347 //where
1348 /** Generate code for a try or synchronized statement
1349 * @param body The body of the try or synchronized statement.
1350 * @param catchers The lis of catch clauses.
1351 * @param env the environment current for the body.
1352 */
1353 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1354 int limit = code.nextreg;
1355 int startpc = code.curPc();
1356 Code.State stateTry = code.state.dup();
1357 genStat(body, env, CRT_BLOCK);
1358 int endpc = code.curPc();
1359 boolean hasFinalizer =
1360 env.info.finalize != null &&
1361 env.info.finalize.hasFinalizer();
1362 List<Integer> gaps = env.info.gaps.toList();
1363 code.statBegin(TreeInfo.endPos(body));
1364 genFinalizer(env);
1365 code.statBegin(TreeInfo.endPos(env.tree));
1366 Chain exitChain = code.branch(goto_);
1367 endFinalizerGap(env);
1368 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1369 // start off with exception on stack
1370 code.entryPoint(stateTry, l.head.param.sym.type);
1371 genCatch(l.head, env, startpc, endpc, gaps);
1372 genFinalizer(env);
1373 if (hasFinalizer || l.tail.nonEmpty()) {
1374 code.statBegin(TreeInfo.endPos(env.tree));
1375 exitChain = code.mergeChains(exitChain,
1376 code.branch(goto_));
1377 }
1378 endFinalizerGap(env);
1379 }
1380 if (hasFinalizer) {
1381 // Create a new register segement to avoid allocating
1382 // the same variables in finalizers and other statements.
1383 code.newRegSegment();
1384
1385 // Add a catch-all clause.
1386
1387 // start off with exception on stack
1388 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1389
1390 // Register all exception ranges for catch all clause.
1391 // The range of the catch all clause is from the beginning
1392 // of the try or synchronized block until the present
1393 // code pointer excluding all gaps in the current
1394 // environment's GenContext.
1395 int startseg = startpc;
1396 while (env.info.gaps.nonEmpty()) {
1397 int endseg = env.info.gaps.next().intValue();
1398 registerCatch(body.pos(), startseg, endseg,
1399 catchallpc, 0);
1400 startseg = env.info.gaps.next().intValue();
1401 }
1402 code.statBegin(TreeInfo.finalizerPos(env.tree));
1403 code.markStatBegin();
1404
1405 Item excVar = makeTemp(syms.throwableType);
1406 excVar.store();
1407 genFinalizer(env);
1408 excVar.load();
1409 registerCatch(body.pos(), startseg,
1410 env.info.gaps.next().intValue(),
1411 catchallpc, 0);
1412 code.emitop0(athrow);
1413 code.markDead();
1414
1415 // If there are jsr's to this finalizer, ...
1416 if (env.info.cont != null) {
1417 // Resolve all jsr's.
1418 code.resolve(env.info.cont);
1419
1420 // Mark statement line number
1421 code.statBegin(TreeInfo.finalizerPos(env.tree));
1422 code.markStatBegin();
1423
1424 // Save return address.
1425 LocalItem retVar = makeTemp(syms.throwableType);
1426 retVar.store();
1427
1428 // Generate finalizer code.
1429 env.info.finalize.genLast();
1430
1431 // Return.
1432 code.emitop1w(ret, retVar.reg);
1433 code.markDead();
1434 }
1435 }
1436
1437 // Resolve all breaks.
1438 code.resolve(exitChain);
1439
1440 // End the scopes of all try-local variables in variable info.
1441 code.endScopes(limit);
1442 }
1443
1444 /** Generate code for a catch clause.
1445 * @param tree The catch clause.
1446 * @param env The environment current in the enclosing try.
1447 * @param startpc Start pc of try-block.
1448 * @param endpc End pc of try-block.
1449 */
1450 void genCatch(JCCatch tree,
1451 Env<GenContext> env,
1452 int startpc, int endpc,
1453 List<Integer> gaps) {
1454 if (startpc != endpc) {
1455 int catchType = makeRef(tree.pos(), tree.param.type);
1456 while (gaps.nonEmpty()) {
1457 int end = gaps.head.intValue();
1458 registerCatch(tree.pos(),
1459 startpc, end, code.curPc(),
1460 catchType);
1461 gaps = gaps.tail;
1462 startpc = gaps.head.intValue();
1463 gaps = gaps.tail;
1464 }
1465 if (startpc < endpc)
1466 registerCatch(tree.pos(),
1467 startpc, endpc, code.curPc(),
1468 catchType);
1469 VarSymbol exparam = tree.param.sym;
1470 code.statBegin(tree.pos);
1471 code.markStatBegin();
1472 int limit = code.nextreg;
1473 int exlocal = code.newLocal(exparam);
1474 items.makeLocalItem(exparam).store();
1475 code.statBegin(TreeInfo.firstStatPos(tree.body));
1476 genStat(tree.body, env, CRT_BLOCK);
1477 code.endScopes(limit);
1478 code.statBegin(TreeInfo.endPos(tree.body));
1479 }
1480 }
1481
1482 /** Register a catch clause in the "Exceptions" code-attribute.
1483 */
1484 void registerCatch(DiagnosticPosition pos,
1485 int startpc, int endpc,
1486 int handler_pc, int catch_type) {
1487 if (startpc != endpc) {
1488 char startpc1 = (char)startpc;
1489 char endpc1 = (char)endpc;
1490 char handler_pc1 = (char)handler_pc;
1491 if (startpc1 == startpc &&
1492 endpc1 == endpc &&
1493 handler_pc1 == handler_pc) {
1494 code.addCatch(startpc1, endpc1, handler_pc1,
1495 (char)catch_type);
1496 } else {
1497 if (!useJsrLocally && !target.generateStackMapTable()) {
1498 useJsrLocally = true;
1499 throw new CodeSizeOverflow();
1500 } else {
1501 log.error(pos, "limit.code.too.large.for.try.stmt");
1502 nerrs++;
1503 }
1504 }
1505 }
1506 }
1507
1508 /** Very roughly estimate the number of instructions needed for
1509 * the given tree.
1510 */
1511 int estimateCodeComplexity(JCTree tree) {
1512 if (tree == null) return 0;
1513 class ComplexityScanner extends TreeScanner {
1514 int complexity = 0;
1515 public void scan(JCTree tree) {
1516 if (complexity > jsrlimit) return;
1517 super.scan(tree);
1518 }
1519 public void visitClassDef(JCClassDecl tree) {}
1520 public void visitDoLoop(JCDoWhileLoop tree)
1521 { super.visitDoLoop(tree); complexity++; }
1522 public void visitWhileLoop(JCWhileLoop tree)
1523 { super.visitWhileLoop(tree); complexity++; }
1524 public void visitForLoop(JCForLoop tree)
1525 { super.visitForLoop(tree); complexity++; }
1526 public void visitSwitch(JCSwitch tree)
1527 { super.visitSwitch(tree); complexity+=5; }
1528 public void visitCase(JCCase tree)
1529 { super.visitCase(tree); complexity++; }
1530 public void visitSynchronized(JCSynchronized tree)
1531 { super.visitSynchronized(tree); complexity+=6; }
1532 public void visitTry(JCTry tree)
1533 { super.visitTry(tree);
1534 if (tree.finalizer != null) complexity+=6; }
1535 public void visitCatch(JCCatch tree)
1536 { super.visitCatch(tree); complexity+=2; }
1537 public void visitConditional(JCConditional tree)
1538 { super.visitConditional(tree); complexity+=2; }
1539 public void visitIf(JCIf tree)
1540 { super.visitIf(tree); complexity+=2; }
1541 // note: for break, continue, and return we don't take unwind() into account.
1542 public void visitBreak(JCBreak tree)
1543 { super.visitBreak(tree); complexity+=1; }
1544 public void visitContinue(JCContinue tree)
1545 { super.visitContinue(tree); complexity+=1; }
1546 public void visitReturn(JCReturn tree)
1547 { super.visitReturn(tree); complexity+=1; }
1548 public void visitThrow(JCThrow tree)
1549 { super.visitThrow(tree); complexity+=1; }
1550 public void visitAssert(JCAssert tree)
1551 { super.visitAssert(tree); complexity+=5; }
1552 public void visitApply(JCMethodInvocation tree)
1553 { super.visitApply(tree); complexity+=2; }
1554 public void visitNewClass(JCNewClass tree)
1555 { scan(tree.encl); scan(tree.args); complexity+=2; }
1556 public void visitNewArray(JCNewArray tree)
1557 { super.visitNewArray(tree); complexity+=5; }
1558 public void visitAssign(JCAssign tree)
1559 { super.visitAssign(tree); complexity+=1; }
1560 public void visitAssignop(JCAssignOp tree)
1561 { super.visitAssignop(tree); complexity+=2; }
1562 public void visitUnary(JCUnary tree)
1563 { complexity+=1;
1564 if (tree.type.constValue() == null) super.visitUnary(tree); }
1565 public void visitBinary(JCBinary tree)
1566 { complexity+=1;
1567 if (tree.type.constValue() == null) super.visitBinary(tree); }
1568 public void visitTypeTest(JCInstanceOf tree)
1569 { super.visitTypeTest(tree); complexity+=1; }
1570 public void visitIndexed(JCArrayAccess tree)
1571 { super.visitIndexed(tree); complexity+=1; }
1572 public void visitSelect(JCFieldAccess tree)
1573 { super.visitSelect(tree);
1574 if (tree.sym.kind == VAR) complexity+=1; }
1575 public void visitIdent(JCIdent tree) {
1576 if (tree.sym.kind == VAR) {
1577 complexity+=1;
1578 if (tree.type.constValue() == null &&
1579 tree.sym.owner.kind == TYP)
1580 complexity+=1;
1581 }
1582 }
1583 public void visitLiteral(JCLiteral tree)
1584 { complexity+=1; }
1585 public void visitTree(JCTree tree) {}
1586 public void visitWildcard(JCWildcard tree) {
1587 throw new AssertionError(this.getClass().getName());
1588 }
1589 }
1590 ComplexityScanner scanner = new ComplexityScanner();
1591 tree.accept(scanner);
1592 return scanner.complexity;
1593 }
1594
1595 public void visitIf(JCIf tree) {
1596 int limit = code.nextreg;
1597 Chain thenExit = null;
1598 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1599 CRT_FLOW_CONTROLLER);
1600 Chain elseChain = c.jumpFalse();
1601 if (!c.isFalse()) {
1602 code.resolve(c.trueJumps);
1603 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1604 thenExit = code.branch(goto_);
1605 }
1606 if (elseChain != null) {
1607 code.resolve(elseChain);
1608 if (tree.elsepart != null)
1609 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1610 }
1611 code.resolve(thenExit);
1612 code.endScopes(limit);
1613 }
1614
1615 public void visitExec(JCExpressionStatement tree) {
1616 // Optimize x++ to ++x and x-- to --x.
1617 JCExpression e = tree.expr;
1618 switch (e.getTag()) {
1619 case JCTree.POSTINC:
1620 ((JCUnary) e).setTag(JCTree.PREINC);
1621 break;
1622 case JCTree.POSTDEC:
1623 ((JCUnary) e).setTag(JCTree.PREDEC);
1624 break;
1625 }
1626 genExpr(tree.expr, tree.expr.type).drop();
1627 }
1628
1629 public void visitBreak(JCBreak tree) {
1630 Env<GenContext> targetEnv = unwind(tree.target, env);
1631 assert code.state.stacksize == 0;
1632 targetEnv.info.addExit(code.branch(goto_));
1633 endFinalizerGaps(env, targetEnv);
1634 }
1635
1636 public void visitContinue(JCContinue tree) {
1637 Env<GenContext> targetEnv = unwind(tree.target, env);
1638 assert code.state.stacksize == 0;
1639 targetEnv.info.addCont(code.branch(goto_));
1640 endFinalizerGaps(env, targetEnv);
1641 }
1642
1643 public void visitReturn(JCReturn tree) {
1644 int limit = code.nextreg;
1645 final Env<GenContext> targetEnv;
1646 if (tree.expr != null) {
1647 Item r = genExpr(tree.expr, pt).load();
1648 if (hasFinally(env.enclMethod, env)) {
1649 r = makeTemp(pt);
1650 r.store();
1651 }
1652 targetEnv = unwind(env.enclMethod, env);
1653 r.load();
1654 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
1655 } else {
1656 targetEnv = unwind(env.enclMethod, env);
1657 code.emitop0(return_);
1658 }
1659 endFinalizerGaps(env, targetEnv);
1660 code.endScopes(limit);
1661 }
1662
1663 public void visitThrow(JCThrow tree) {
1664 genExpr(tree.expr, tree.expr.type).load();
1665 code.emitop0(athrow);
1666 }
1667
1668 /* ************************************************************************
1669 * Visitor methods for expressions
1670 *************************************************************************/
1671
1672 public void visitApply(JCMethodInvocation tree) {
1673 // Generate code for method.
1674 Item m = genExpr(tree.meth, methodType);
1675 // Generate code for all arguments, where the expected types are
1676 // the parameters of the method's external type (that is, any implicit
1677 // outer instance of a super(...) call appears as first parameter).
1678 genArgs(tree.args,
1679 TreeInfo.symbol(tree.meth).externalType(types).getParameterTypes());
1680 result = m.invoke();
1681 }
1682
1683 public void visitConditional(JCConditional tree) {
1684 Chain thenExit = null;
1685 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
1686 Chain elseChain = c.jumpFalse();
1687 if (!c.isFalse()) {
1688 code.resolve(c.trueJumps);
1689 int startpc = genCrt ? code.curPc() : 0;
1690 genExpr(tree.truepart, pt).load();
1691 code.state.forceStackTop(tree.type);
1692 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
1693 startpc, code.curPc());
1694 thenExit = code.branch(goto_);
1695 }
1696 if (elseChain != null) {
1697 code.resolve(elseChain);
1698 int startpc = genCrt ? code.curPc() : 0;
1699 genExpr(tree.falsepart, pt).load();
1700 code.state.forceStackTop(tree.type);
1701 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
1702 startpc, code.curPc());
1703 }
1704 code.resolve(thenExit);
1705 result = items.makeStackItem(pt);
1706 }
1707
1708 public void visitNewClass(JCNewClass tree) {
1709 // Enclosing instances or anonymous classes should have been eliminated
1710 // by now.
1711 assert tree.encl == null && tree.def == null;
1712
1713 code.emitop2(new_, makeRef(tree.pos(), tree.type));
1714 code.emitop0(dup);
1715
1716 // Generate code for all arguments, where the expected types are
1717 // the parameters of the constructor's external type (that is,
1718 // any implicit outer instance appears as first parameter).
1719 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
1720
1721 items.makeMemberItem(tree.constructor, true).invoke();
1722 result = items.makeStackItem(tree.type);
1723 }
1724
1725 public void visitNewArray(JCNewArray tree) {
1726 if (tree.elems != null) {
1727 Type elemtype = types.elemtype(tree.type);
1728 loadIntConst(tree.elems.length());
1729 Item arr = makeNewArray(tree.pos(), tree.type, 1);
1730 int i = 0;
1731 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
1732 arr.duplicate();
1733 loadIntConst(i);
1734 i++;
1735 genExpr(l.head, elemtype).load();
1736 items.makeIndexedItem(elemtype).store();
1737 }
1738 result = arr;
1739 } else {
1740 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1741 genExpr(l.head, syms.intType).load();
1742 }
1743 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
1744 }
1745 }
1746 //where
1747 /** Generate code to create an array with given element type and number
1748 * of dimensions.
1749 */
1750 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
1751 Type elemtype = types.elemtype(type);
1752 if (types.dimensions(elemtype) + ndims > ClassFile.MAX_DIMENSIONS) {
1753 log.error(pos, "limit.dimensions");
1754 nerrs++;
1755 }
1756 int elemcode = Code.arraycode(elemtype);
1757 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
1758 code.emitAnewarray(makeRef(pos, elemtype), type);
1759 } else if (elemcode == 1) {
1760 code.emitMultianewarray(ndims, makeRef(pos, type), type);
1761 } else {
1762 code.emitNewarray(elemcode, type);
1763 }
1764 return items.makeStackItem(type);
1765 }
1766
1767 public void visitParens(JCParens tree) {
1768 result = genExpr(tree.expr, tree.expr.type);
1769 }
1770
1771 public void visitAssign(JCAssign tree) {
1772 Item l = genExpr(tree.lhs, tree.lhs.type);
1773 genExpr(tree.rhs, tree.lhs.type).load();
1774 result = items.makeAssignItem(l);
1775 }
1776
1777 public void visitAssignop(JCAssignOp tree) {
1778 OperatorSymbol operator = (OperatorSymbol) tree.operator;
1779 Item l;
1780 if (operator.opcode == string_add) {
1781 // Generate code to make a string buffer
1782 makeStringBuffer(tree.pos());
1783
1784 // Generate code for first string, possibly save one
1785 // copy under buffer
1786 l = genExpr(tree.lhs, tree.lhs.type);
1787 if (l.width() > 0) {
1788 code.emitop0(dup_x1 + 3 * (l.width() - 1));
1789 }
1790
1791 // Load first string and append to buffer.
1792 l.load();
1793 appendString(tree.lhs);
1794
1795 // Append all other strings to buffer.
1796 appendStrings(tree.rhs);
1797
1798 // Convert buffer to string.
1799 bufferToString(tree.pos());
1800 } else {
1801 // Generate code for first expression
1802 l = genExpr(tree.lhs, tree.lhs.type);
1803
1804 // If we have an increment of -32768 to +32767 of a local
1805 // int variable we can use an incr instruction instead of
1806 // proceeding further.
1807 if ((tree.getTag() == JCTree.PLUS_ASG || tree.getTag() == JCTree.MINUS_ASG) &&
1808 l instanceof LocalItem &&
1809 tree.lhs.type.tag <= INT &&
1810 tree.rhs.type.tag <= INT &&
1811 tree.rhs.type.constValue() != null) {
1812 int ival = ((Number) tree.rhs.type.constValue()).intValue();
1813 if (tree.getTag() == JCTree.MINUS_ASG) ival = -ival;
1814 ((LocalItem)l).incr(ival);
1815 result = l;
1816 return;
1817 }
1818 // Otherwise, duplicate expression, load one copy
1819 // and complete binary operation.
1820 l.duplicate();
1821 l.coerce(operator.type.getParameterTypes().head).load();
1822 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
1823 }
1824 result = items.makeAssignItem(l);
1825 }
1826
1827 public void visitUnary(JCUnary tree) {
1828 OperatorSymbol operator = (OperatorSymbol)tree.operator;
1829 if (tree.getTag() == JCTree.NOT) {
1830 CondItem od = genCond(tree.arg, false);
1831 result = od.negate();
1832 } else {
1833 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
1834 switch (tree.getTag()) {
1835 case JCTree.POS:
1836 result = od.load();
1837 break;
1838 case JCTree.NEG:
1839 result = od.load();
1840 code.emitop0(operator.opcode);
1841 break;
1842 case JCTree.COMPL:
1843 result = od.load();
1844 emitMinusOne(od.typecode);
1845 code.emitop0(operator.opcode);
1846 break;
1847 case JCTree.PREINC: case JCTree.PREDEC:
1848 od.duplicate();
1849 if (od instanceof LocalItem &&
1850 (operator.opcode == iadd || operator.opcode == isub)) {
1851 ((LocalItem)od).incr(tree.getTag() == JCTree.PREINC ? 1 : -1);
1852 result = od;
1853 } else {
1854 od.load();
1855 code.emitop0(one(od.typecode));
1856 code.emitop0(operator.opcode);
1857 // Perform narrowing primitive conversion if byte,
1858 // char, or short. Fix for 4304655.
1859 if (od.typecode != INTcode &&
1860 Code.truncate(od.typecode) == INTcode)
1861 code.emitop0(int2byte + od.typecode - BYTEcode);
1862 result = items.makeAssignItem(od);
1863 }
1864 break;
1865 case JCTree.POSTINC: case JCTree.POSTDEC:
1866 od.duplicate();
1867 if (od instanceof LocalItem &&
1868 (operator.opcode == iadd || operator.opcode == isub)) {
1869 Item res = od.load();
1870 ((LocalItem)od).incr(tree.getTag() == JCTree.POSTINC ? 1 : -1);
1871 result = res;
1872 } else {
1873 Item res = od.load();
1874 od.stash(od.typecode);
1875 code.emitop0(one(od.typecode));
1876 code.emitop0(operator.opcode);
1877 // Perform narrowing primitive conversion if byte,
1878 // char, or short. Fix for 4304655.
1879 if (od.typecode != INTcode &&
1880 Code.truncate(od.typecode) == INTcode)
1881 code.emitop0(int2byte + od.typecode - BYTEcode);
1882 od.store();
1883 result = res;
1884 }
1885 break;
1886 case JCTree.NULLCHK:
1887 result = od.load();
1888 code.emitop0(dup);
1889 genNullCheck(tree.pos());
1890 break;
1891 default:
1892 assert false;
1893 }
1894 }
1895 }
1896
1897 /** Generate a null check from the object value at stack top. */
1898 private void genNullCheck(DiagnosticPosition pos) {
1899 callMethod(pos, syms.objectType, names.getClass,
1900 List.<Type>nil(), false);
1901 code.emitop0(pop);
1902 }
1903
1904 public void visitBinary(JCBinary tree) {
1905 OperatorSymbol operator = (OperatorSymbol)tree.operator;
1906 if (operator.opcode == string_add) {
1907 // Create a string buffer.
1908 makeStringBuffer(tree.pos());
1909 // Append all strings to buffer.
1910 appendStrings(tree);
1911 // Convert buffer to string.
1912 bufferToString(tree.pos());
1913 result = items.makeStackItem(syms.stringType);
1914 } else if (tree.getTag() == JCTree.AND) {
1915 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
1916 if (!lcond.isFalse()) {
1917 Chain falseJumps = lcond.jumpFalse();
1918 code.resolve(lcond.trueJumps);
1919 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
1920 result = items.
1921 makeCondItem(rcond.opcode,
1922 rcond.trueJumps,
1923 code.mergeChains(falseJumps,
1924 rcond.falseJumps));
1925 } else {
1926 result = lcond;
1927 }
1928 } else if (tree.getTag() == JCTree.OR) {
1929 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
1930 if (!lcond.isTrue()) {
1931 Chain trueJumps = lcond.jumpTrue();
1932 code.resolve(lcond.falseJumps);
1933 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
1934 result = items.
1935 makeCondItem(rcond.opcode,
1936 code.mergeChains(trueJumps, rcond.trueJumps),
1937 rcond.falseJumps);
1938 } else {
1939 result = lcond;
1940 }
1941 } else {
1942 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
1943 od.load();
1944 result = completeBinop(tree.lhs, tree.rhs, operator);
1945 }
1946 }
1947 //where
1948 /** Make a new string buffer.
1949 */
1950 void makeStringBuffer(DiagnosticPosition pos) {
1951 code.emitop2(new_, makeRef(pos, stringBufferType));
1952 code.emitop0(dup);
1953 callMethod(
1954 pos, stringBufferType, names.init, List.<Type>nil(), false);
1955 }
1956
1957 /** Append value (on tos) to string buffer (on tos - 1).
1958 */
1959 void appendString(JCTree tree) {
1960 Type t = tree.type.baseType();
1961 if (t.tag > lastBaseTag && t.tsym != syms.stringType.tsym) {
1962 t = syms.objectType;
1963 }
1964 items.makeMemberItem(getStringBufferAppend(tree, t), false).invoke();
1965 }
1966 Symbol getStringBufferAppend(JCTree tree, Type t) {
1967 assert t.constValue() == null;
1968 Symbol method = stringBufferAppend.get(t);
1969 if (method == null) {
1970 method = rs.resolveInternalMethod(tree.pos(),
1971 attrEnv,
1972 stringBufferType,
1973 names.append,
1974 List.of(t),
1975 null);
1976 stringBufferAppend.put(t, method);
1977 }
1978 return method;
1979 }
1980
1981 /** Add all strings in tree to string buffer.
1982 */
1983 void appendStrings(JCTree tree) {
1984 tree = TreeInfo.skipParens(tree);
1985 if (tree.getTag() == JCTree.PLUS && tree.type.constValue() == null) {
1986 JCBinary op = (JCBinary) tree;
1987 if (op.operator.kind == MTH &&
1988 ((OperatorSymbol) op.operator).opcode == string_add) {
1989 appendStrings(op.lhs);
1990 appendStrings(op.rhs);
1991 return;
1992 }
1993 }
1994 genExpr(tree, tree.type).load();
1995 appendString(tree);
1996 }
1997
1998 /** Convert string buffer on tos to string.
1999 */
2000 void bufferToString(DiagnosticPosition pos) {
2001 callMethod(
2002 pos,
2003 stringBufferType,
2004 names.toString,
2005 List.<Type>nil(),
2006 false);
2007 }
2008
2009 /** Complete generating code for operation, with left operand
2010 * already on stack.
2011 * @param lhs The tree representing the left operand.
2012 * @param rhs The tree representing the right operand.
2013 * @param operator The operator symbol.
2014 */
2015 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2016 MethodType optype = (MethodType)operator.type;
2017 int opcode = operator.opcode;
2018 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2019 rhs.type.constValue() instanceof Number &&
2020 ((Number) rhs.type.constValue()).intValue() == 0) {
2021 opcode = opcode + (ifeq - if_icmpeq);
2022 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2023 TreeInfo.isNull(rhs)) {
2024 opcode = opcode + (if_acmp_null - if_acmpeq);
2025 } else {
2026 // The expected type of the right operand is
2027 // the second parameter type of the operator, except for
2028 // shifts with long shiftcount, where we convert the opcode
2029 // to a short shift and the expected type to int.
2030 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2031 if (opcode >= ishll && opcode <= lushrl) {
2032 opcode = opcode + (ishl - ishll);
2033 rtype = syms.intType;
2034 }
2035 // Generate code for right operand and load.
2036 genExpr(rhs, rtype).load();
2037 // If there are two consecutive opcode instructions,
2038 // emit the first now.
2039 if (opcode >= (1 << preShift)) {
2040 code.emitop0(opcode >> preShift);
2041 opcode = opcode & 0xFF;
2042 }
2043 }
2044 if (opcode >= ifeq && opcode <= if_acmpne ||
2045 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2046 return items.makeCondItem(opcode);
2047 } else {
2048 code.emitop0(opcode);
2049 return items.makeStackItem(optype.restype);
2050 }
2051 }
2052
2053 public void visitTypeCast(JCTypeCast tree) {
2054 result = genExpr(tree.expr, tree.clazz.type).load();
2055 // Additional code is only needed if we cast to a reference type
2056 // which is not statically a supertype of the expression's type.
2057 // For basic types, the coerce(...) in genExpr(...) will do
2058 // the conversion.
2059 if (tree.clazz.type.tag > lastBaseTag &&
2060 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2061 code.emitop2(checkcast, makeRef(tree.pos(), tree.clazz.type));
2062 }
2063 }
2064
2065 public void visitWildcard(JCWildcard tree) {
2066 throw new AssertionError(this.getClass().getName());
2067 }
2068
2069 public void visitTypeTest(JCInstanceOf tree) {
2070 genExpr(tree.expr, tree.expr.type).load();
2071 code.emitop2(instanceof_, makeRef(tree.pos(), tree.clazz.type));
2072 result = items.makeStackItem(syms.booleanType);
2073 }
2074
2075 public void visitIndexed(JCArrayAccess tree) {
2076 genExpr(tree.indexed, tree.indexed.type).load();
2077 genExpr(tree.index, syms.intType).load();
2078 result = items.makeIndexedItem(tree.type);
2079 }
2080
2081 public void visitIdent(JCIdent tree) {
2082 Symbol sym = tree.sym;
2083 if (tree.name == names._this || tree.name == names._super) {
2084 Item res = tree.name == names._this
2085 ? items.makeThisItem()
2086 : items.makeSuperItem();
2087 if (sym.kind == MTH) {
2088 // Generate code to address the constructor.
2089 res.load();
2090 res = items.makeMemberItem(sym, true);
2091 }
2092 result = res;
2093 } else if (sym.kind == VAR && sym.owner.kind == MTH) {
2094 result = items.makeLocalItem((VarSymbol)sym);
2095 } else if ((sym.flags() & STATIC) != 0) {
2096 if (!isAccessSuper(env.enclMethod))
2097 sym = binaryQualifier(sym, env.enclClass.type);
2098 result = items.makeStaticItem(sym);
2099 } else {
2100 items.makeThisItem().load();
2101 sym = binaryQualifier(sym, env.enclClass.type);
2102 result = items.makeMemberItem(sym, (sym.flags() & PRIVATE) != 0);
2103 }
2104 }
2105
2106 public void visitSelect(JCFieldAccess tree) {
2107 Symbol sym = tree.sym;
2108
2109 if (tree.name == names._class) {
2110 assert target.hasClassLiterals();
2111 code.emitop2(ldc2, makeRef(tree.pos(), tree.selected.type));
2112 result = items.makeStackItem(pt);
2113 return;
2114 }
2115
2116 Symbol ssym = TreeInfo.symbol(tree.selected);
2117
2118 // Are we selecting via super?
2119 boolean selectSuper =
2120 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2121
2122 // Are we accessing a member of the superclass in an access method
2123 // resulting from a qualified super?
2124 boolean accessSuper = isAccessSuper(env.enclMethod);
2125
2126 Item base = (selectSuper)
2127 ? items.makeSuperItem()
2128 : genExpr(tree.selected, tree.selected.type);
2129
2130 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2131 // We are seeing a variable that is constant but its selecting
2132 // expression is not.
2133 if ((sym.flags() & STATIC) != 0) {
2134 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2135 base = base.load();
2136 base.drop();
2137 } else {
2138 base.load();
2139 genNullCheck(tree.selected.pos());
2140 }
2141 result = items.
2142 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2143 } else {
2144 if (!accessSuper)
2145 sym = binaryQualifier(sym, tree.selected.type);
2146 if ((sym.flags() & STATIC) != 0) {
2147 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2148 base = base.load();
2149 base.drop();
2150 result = items.makeStaticItem(sym);
2151 } else {
2152 base.load();
2153 if (sym == syms.lengthVar) {
2154 code.emitop0(arraylength);
2155 result = items.makeStackItem(syms.intType);
2156 } else {
2157 result = items.
2158 makeMemberItem(sym,
2159 (sym.flags() & PRIVATE) != 0 ||
2160 selectSuper || accessSuper);
2161 }
2162 }
2163 }
2164 }
2165
2166 public void visitLiteral(JCLiteral tree) {
2167 if (tree.type.tag == TypeTags.BOT) {
2168 code.emitop0(aconst_null);
2169 if (types.dimensions(pt) > 1) {
2170 code.emitop2(checkcast, makeRef(tree.pos(), pt));
2171 result = items.makeStackItem(pt);
2172 } else {
2173 result = items.makeStackItem(tree.type);
2174 }
2175 }
2176 else
2177 result = items.makeImmediateItem(tree.type, tree.value);
2178 }
2179
2180 public void visitLetExpr(LetExpr tree) {
2181 int limit = code.nextreg;
2182 genStats(tree.defs, env);
2183 result = genExpr(tree.expr, tree.expr.type).load();
2184 code.endScopes(limit);
2185 }
2186
2187 /* ************************************************************************
2188 * main method
2189 *************************************************************************/
2190
2191 /** Generate code for a class definition.
2192 * @param env The attribution environment that belongs to the
2193 * outermost class containing this class definition.
2194 * We need this for resolving some additional symbols.
2195 * @param cdef The tree representing the class definition.
2196 * @return True if code is generated with no errors.
2197 */
2198 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2199 try {
2200 attrEnv = env;
2201 ClassSymbol c = cdef.sym;
2202 this.toplevel = env.toplevel;
2203 this.endPositions = toplevel.endPositions;
2204 // If this is a class definition requiring Miranda methods,
2205 // add them.
2206 if (generateIproxies &&
2207 (c.flags() & (INTERFACE|ABSTRACT)) == ABSTRACT
2208 && !allowGenerics // no Miranda methods available with generics
2209 )
2210 implementInterfaceMethods(c);
2211 cdef.defs = normalizeDefs(cdef.defs, c);
2212 c.pool = pool;
2213 pool.reset();
2214 Env<GenContext> localEnv =
2215 new Env<GenContext>(cdef, new GenContext());
2216 localEnv.toplevel = env.toplevel;
2217 localEnv.enclClass = cdef;
2218 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2219 genDef(l.head, localEnv);
2220 }
2221 if (pool.numEntries() > Pool.MAX_ENTRIES) {
2222 log.error(cdef.pos(), "limit.pool");
2223 nerrs++;
2224 }
2225 if (nerrs != 0) {
2226 // if errors, discard code
2227 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2228 if (l.head.getTag() == JCTree.METHODDEF)
2229 ((JCMethodDecl) l.head).sym.code = null;
2230 }
2231 }
2232 cdef.defs = List.nil(); // discard trees
2233 return nerrs == 0;
2234 } finally {
2235 // note: this method does NOT support recursion.
2236 attrEnv = null;
2237 this.env = null;
2238 toplevel = null;
2239 endPositions = null;
2240 nerrs = 0;
2241 }
2242 }
2243
2244 /* ************************************************************************
2245 * Auxiliary classes
2246 *************************************************************************/
2247
2248 /** An abstract class for finalizer generation.
2249 */
2250 abstract class GenFinalizer {
2251 /** Generate code to clean up when unwinding. */
2252 abstract void gen();
2253
2254 /** Generate code to clean up at last. */
2255 abstract void genLast();
2256
2257 /** Does this finalizer have some nontrivial cleanup to perform? */
2258 boolean hasFinalizer() { return true; }
2259 }
2260
2261 /** code generation contexts,
2262 * to be used as type parameter for environments.
2263 */
2264 static class GenContext {
2265
2266 /** A chain for all unresolved jumps that exit the current environment.
2267 */
2268 Chain exit = null;
2269
2270 /** A chain for all unresolved jumps that continue in the
2271 * current environment.
2272 */
2273 Chain cont = null;
2274
2275 /** A closure that generates the finalizer of the current environment.
2276 * Only set for Synchronized and Try contexts.
2277 */
2278 GenFinalizer finalize = null;
2279
2280 /** Is this a switch statement? If so, allocate registers
2281 * even when the variable declaration is unreachable.
2282 */
2283 boolean isSwitch = false;
2284
2285 /** A list buffer containing all gaps in the finalizer range,
2286 * where a catch all exception should not apply.
2287 */
2288 ListBuffer<Integer> gaps = null;
2289
2290 /** Add given chain to exit chain.
2291 */
2292 void addExit(Chain c) {
2293 exit = Code.mergeChains(c, exit);
2294 }
2295
2296 /** Add given chain to cont chain.
2297 */
2298 void addCont(Chain c) {
2299 cont = Code.mergeChains(c, cont);
2300 }
2301 }
2302 }