1 /*
2 * Copyright (c) 1999, 2015, 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 */
25
26 package com.sun.tools.javac.jvm;
27
28 import java.util.*;
29
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.*;
38
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.*;
45
46 import static com.sun.tools.javac.code.Flags.*;
47 import static com.sun.tools.javac.code.Kinds.Kind.*;
48 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE;
49 import static com.sun.tools.javac.code.TypeTag.*;
50 import static com.sun.tools.javac.jvm.ByteCodes.*;
51 import static com.sun.tools.javac.jvm.CRTFlags.*;
52 import static com.sun.tools.javac.main.Option.*;
53 import static com.sun.tools.javac.tree.JCTree.Tag.*;
54
55 /** This pass maps flat Java (i.e. without inner classes) to bytecodes.
56 *
57 * <p><b>This is NOT part of any supported API.
58 * If you write code that depends on this, you do so at your own risk.
59 * This code and its internal interfaces are subject to change or
60 * deletion without notice.</b>
61 */
62 public class Gen extends JCTree.Visitor {
63 protected static final Context.Key<Gen> genKey = new Context.Key<>();
64
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;
78
79 /** Format of stackmap tables to be generated. */
80 private final Code.StackMapFormat stackMap;
81
82 /** A type that serves as the expected type for all method expressions.
83 */
84 private final Type methodType;
85
86 public static Gen instance(Context context) {
87 Gen instance = context.get(genKey);
88 if (instance == null)
89 instance = new Gen(context);
90 return instance;
91 }
92
93 /** Constant pool, reset by genClass.
94 */
95 private Pool pool;
96
97 protected Gen(Context context) {
98 context.put(genKey, this);
99
100 names = Names.instance(context);
101 log = Log.instance(context);
102 syms = Symtab.instance(context);
103 chk = Check.instance(context);
104 rs = Resolve.instance(context);
105 make = TreeMaker.instance(context);
106 target = Target.instance(context);
107 types = Types.instance(context);
108 methodType = new MethodType(null, null, null, syms.methodClass);
109 stringBufferType = syms.stringBuilderType;
110 stringBufferAppend = new HashMap<>();
111 accessDollar = names.
112 fromString("access" + target.syntheticNameChar());
113 flow = Flow.instance(context);
114 lower = Lower.instance(context);
115
116 Options options = Options.instance(context);
117 lineDebugInfo =
118 options.isUnset(G_CUSTOM) ||
119 options.isSet(G_CUSTOM, "lines");
120 varDebugInfo =
121 options.isUnset(G_CUSTOM)
122 ? options.isSet(G)
123 : options.isSet(G_CUSTOM, "vars");
124 genCrt = options.isSet(XJCOV);
125 debugCode = options.isSet("debugcode");
126 allowInvokedynamic = target.hasInvokedynamic() || options.isSet("invokedynamic");
127 pool = new Pool(types);
128
129 // ignore cldc because we cannot have both stackmap formats
130 this.stackMap = StackMapFormat.JSR202;
131
132 // by default, avoid jsr's for simple finalizers
133 int setjsrlimit = 50;
134 String jsrlimitString = options.get("jsrlimit");
135 if (jsrlimitString != null) {
136 try {
137 setjsrlimit = Integer.parseInt(jsrlimitString);
138 } catch (NumberFormatException ex) {
139 // ignore ill-formed numbers for jsrlimit
140 }
141 }
142 this.jsrlimit = setjsrlimit;
143 this.useJsrLocally = false; // reset in visitTry
144 }
145
146 /** Switches
147 */
148 private final boolean lineDebugInfo;
149 private final boolean varDebugInfo;
150 private final boolean genCrt;
151 private final boolean debugCode;
152 private final boolean allowInvokedynamic;
153
154 /** Default limit of (approximate) size of finalizer to inline.
155 * Zero means always use jsr. 100 or greater means never use
156 * jsr.
157 */
158 private final int jsrlimit;
159
160 /** True if jsr is used.
161 */
162 private boolean useJsrLocally;
163
164 /** Code buffer, set by genMethod.
165 */
166 private Code code;
167
168 /** Items structure, set by genMethod.
169 */
170 private Items items;
171
172 /** Environment for symbol lookup, set by genClass
173 */
174 private Env<AttrContext> attrEnv;
175
176 /** The top level tree.
177 */
178 private JCCompilationUnit toplevel;
179
180 /** The number of code-gen errors in this class.
181 */
182 private int nerrs = 0;
183
184 /** An object containing mappings of syntax trees to their
185 * ending source positions.
186 */
187 EndPosTable endPosTable;
188
189 /** Generate code to load an integer constant.
190 * @param n The integer to be loaded.
191 */
192 void loadIntConst(int n) {
193 items.makeImmediateItem(syms.intType, n).load();
194 }
195
196 /** The opcode that loads a zero constant of a given type code.
197 * @param tc The given type code (@see ByteCode).
198 */
199 public static int zero(int tc) {
200 switch(tc) {
201 case INTcode: case BYTEcode: case SHORTcode: case CHARcode:
202 return iconst_0;
203 case LONGcode:
204 return lconst_0;
205 case FLOATcode:
206 return fconst_0;
207 case DOUBLEcode:
208 return dconst_0;
209 default:
210 throw new AssertionError("zero");
211 }
212 }
213
214 /** The opcode that loads a one constant of a given type code.
215 * @param tc The given type code (@see ByteCode).
216 */
217 public static int one(int tc) {
218 return zero(tc) + 1;
219 }
220
221 /** Generate code to load -1 of the given type code (either int or long).
222 * @param tc The given type code (@see ByteCode).
223 */
224 void emitMinusOne(int tc) {
225 if (tc == LONGcode) {
226 items.makeImmediateItem(syms.longType, new Long(-1)).load();
227 } else {
228 code.emitop0(iconst_m1);
229 }
230 }
231
232 /** Construct a symbol to reflect the qualifying type that should
233 * appear in the byte code as per JLS 13.1.
234 *
235 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except
236 * for those cases where we need to work around VM bugs).
237 *
238 * For {@literal target <= 1.1}: If qualified variable or method is defined in a
239 * non-accessible class, clone it with the qualifier class as owner.
240 *
241 * @param sym The accessed symbol
242 * @param site The qualifier's type.
243 */
244 Symbol binaryQualifier(Symbol sym, Type site) {
245
246 if (site.hasTag(ARRAY)) {
247 if (sym == syms.lengthVar ||
248 sym.owner != syms.arrayClass)
249 return sym;
250 // array clone can be qualified by the array type in later targets
251 Symbol qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name,
252 site, syms.noSymbol);
253 return sym.clone(qualifier);
254 }
255
256 if (sym.owner == site.tsym ||
257 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) {
258 return sym;
259 }
260
261 // leave alone methods inherited from Object
262 // JLS 13.1.
263 if (sym.owner == syms.objectType.tsym)
264 return sym;
265
266 return sym.clone(site.tsym);
267 }
268
269 /** Insert a reference to given type in the constant pool,
270 * checking for an array with too many dimensions;
271 * return the reference's index.
272 * @param type The type for which a reference is inserted.
273 */
274 int makeRef(DiagnosticPosition pos, Type type) {
275 checkDimension(pos, type);
276 if (type.isAnnotated()) {
277 return pool.put((Object)type);
278 } else {
279 return pool.put(type.hasTag(CLASS) ? (Object)type.tsym : (Object)type);
280 }
281 }
282
283 /** Check if the given type is an array with too many dimensions.
284 */
285 private void checkDimension(DiagnosticPosition pos, Type t) {
286 switch (t.getTag()) {
287 case METHOD:
288 checkDimension(pos, t.getReturnType());
289 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail)
290 checkDimension(pos, args.head);
291 break;
292 case ARRAY:
293 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) {
294 log.error(pos, "limit.dimensions");
295 nerrs++;
296 }
297 break;
298 default:
299 break;
300 }
301 }
302
303 /** Create a tempory variable.
304 * @param type The variable's type.
305 */
306 LocalItem makeTemp(Type type) {
307 VarSymbol v = new VarSymbol(Flags.SYNTHETIC,
308 names.empty,
309 type,
310 env.enclMethod.sym);
311 code.newLocal(v);
312 return items.makeLocalItem(v);
313 }
314
315 /** Generate code to call a non-private method or constructor.
316 * @param pos Position to be used for error reporting.
317 * @param site The type of which the method is a member.
318 * @param name The method's name.
319 * @param argtypes The method's argument types.
320 * @param isStatic A flag that indicates whether we call a
321 * static or instance method.
322 */
323 void callMethod(DiagnosticPosition pos,
324 Type site, Name name, List<Type> argtypes,
325 boolean isStatic) {
326 Symbol msym = rs.
327 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null);
328 if (isStatic) items.makeStaticItem(msym).invoke();
329 else items.makeMemberItem(msym, name == names.init).invoke();
330 }
331
332 /** Is the given method definition an access method
333 * resulting from a qualified super? This is signified by an odd
334 * access code.
335 */
336 private boolean isAccessSuper(JCMethodDecl enclMethod) {
337 return
338 (enclMethod.mods.flags & SYNTHETIC) != 0 &&
339 isOddAccessName(enclMethod.name);
340 }
341
342 /** Does given name start with "access$" and end in an odd digit?
343 */
344 private boolean isOddAccessName(Name name) {
345 return
346 name.startsWith(accessDollar) &&
347 (name.getByteAt(name.getByteLength() - 1) & 1) == 1;
348 }
349
350 /* ************************************************************************
351 * Non-local exits
352 *************************************************************************/
353
354 /** Generate code to invoke the finalizer associated with given
355 * environment.
356 * Any calls to finalizers are appended to the environments `cont' chain.
357 * Mark beginning of gap in catch all range for finalizer.
358 */
359 void genFinalizer(Env<GenContext> env) {
360 if (code.isAlive() && env.info.finalize != null)
361 env.info.finalize.gen();
362 }
363
364 /** Generate code to call all finalizers of structures aborted by
365 * a non-local
366 * exit. Return target environment of the non-local exit.
367 * @param target The tree representing the structure that's aborted
368 * @param env The environment current at the non-local exit.
369 */
370 Env<GenContext> unwind(JCTree target, Env<GenContext> env) {
371 Env<GenContext> env1 = env;
372 while (true) {
373 genFinalizer(env1);
374 if (env1.tree == target) break;
375 env1 = env1.next;
376 }
377 return env1;
378 }
379
380 /** Mark end of gap in catch-all range for finalizer.
381 * @param env the environment which might contain the finalizer
382 * (if it does, env.info.gaps != null).
383 */
384 void endFinalizerGap(Env<GenContext> env) {
385 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1)
386 env.info.gaps.append(code.curCP());
387 }
388
389 /** Mark end of all gaps in catch-all ranges for finalizers of environments
390 * lying between, and including to two environments.
391 * @param from the most deeply nested environment to mark
392 * @param to the least deeply nested environment to mark
393 */
394 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) {
395 Env<GenContext> last = null;
396 while (last != to) {
397 endFinalizerGap(from);
398 last = from;
399 from = from.next;
400 }
401 }
402
403 /** Do any of the structures aborted by a non-local exit have
404 * finalizers that require an empty stack?
405 * @param target The tree representing the structure that's aborted
406 * @param env The environment current at the non-local exit.
407 */
408 boolean hasFinally(JCTree target, Env<GenContext> env) {
409 while (env.tree != target) {
410 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer())
411 return true;
412 env = env.next;
413 }
414 return false;
415 }
416
417 /* ************************************************************************
418 * Normalizing class-members.
419 *************************************************************************/
420
421 /** Distribute member initializer code into constructors and {@code <clinit>}
422 * method.
423 * @param defs The list of class member declarations.
424 * @param c The enclosing class.
425 */
426 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) {
427 ListBuffer<JCStatement> initCode = new ListBuffer<>();
428 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>();
429 ListBuffer<JCStatement> clinitCode = new ListBuffer<>();
430 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>();
431 ListBuffer<JCTree> methodDefs = new ListBuffer<>();
432 // Sort definitions into three listbuffers:
433 // - initCode for instance initializers
434 // - clinitCode for class initializers
435 // - methodDefs for method definitions
436 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
437 JCTree def = l.head;
438 switch (def.getTag()) {
439 case BLOCK:
440 JCBlock block = (JCBlock)def;
441 if ((block.flags & STATIC) != 0)
442 clinitCode.append(block);
443 else if ((block.flags & SYNTHETIC) == 0)
444 initCode.append(block);
445 break;
446 case METHODDEF:
447 methodDefs.append(def);
448 break;
449 case VARDEF:
450 JCVariableDecl vdef = (JCVariableDecl) def;
451 VarSymbol sym = vdef.sym;
452 checkDimension(vdef.pos(), sym.type);
453 if (vdef.init != null) {
454 if ((sym.flags() & STATIC) == 0) {
455 // Always initialize instance variables.
456 JCStatement init = make.at(vdef.pos()).
457 Assignment(sym, vdef.init);
458 initCode.append(init);
459 endPosTable.replaceTree(vdef, init);
460 initTAs.addAll(getAndRemoveNonFieldTAs(sym));
461 } else if (sym.getConstValue() == null) {
462 // Initialize class (static) variables only if
463 // they are not compile-time constants.
464 JCStatement init = make.at(vdef.pos).
465 Assignment(sym, vdef.init);
466 clinitCode.append(init);
467 endPosTable.replaceTree(vdef, init);
468 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym));
469 } else {
470 checkStringConstant(vdef.init.pos(), sym.getConstValue());
471 }
472 }
473 break;
474 default:
475 Assert.error();
476 }
477 }
478 // Insert any instance initializers into all constructors.
479 if (initCode.length() != 0) {
480 List<JCStatement> inits = initCode.toList();
481 initTAs.addAll(c.getInitTypeAttributes());
482 List<Attribute.TypeCompound> initTAlist = initTAs.toList();
483 for (JCTree t : methodDefs) {
484 normalizeMethod((JCMethodDecl)t, inits, initTAlist);
485 }
486 }
487 // If there are class initializers, create a <clinit> method
488 // that contains them as its body.
489 if (clinitCode.length() != 0) {
490 MethodSymbol clinit = new MethodSymbol(
491 STATIC | (c.flags() & STRICTFP),
492 names.clinit,
493 new MethodType(
494 List.<Type>nil(), syms.voidType,
495 List.<Type>nil(), syms.methodClass),
496 c);
497 c.members().enter(clinit);
498 List<JCStatement> clinitStats = clinitCode.toList();
499 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
500 block.endpos = TreeInfo.endPos(clinitStats.last());
501 methodDefs.append(make.MethodDef(clinit, block));
502
503 if (!clinitTAs.isEmpty())
504 clinit.appendUniqueTypeAttributes(clinitTAs.toList());
505 if (!c.getClassInitTypeAttributes().isEmpty())
506 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes());
507 }
508 // Return all method definitions.
509 return methodDefs.toList();
510 }
511
512 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) {
513 List<TypeCompound> tas = sym.getRawTypeAttributes();
514 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>();
515 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>();
516 for (TypeCompound ta : tas) {
517 Assert.check(ta.getPosition().type != TargetType.UNKNOWN);
518 if (ta.getPosition().type == TargetType.FIELD) {
519 fieldTAs.add(ta);
520 } else {
521 nonfieldTAs.add(ta);
522 }
523 }
524 sym.setTypeAttributes(fieldTAs.toList());
525 return nonfieldTAs.toList();
526 }
527
528 /** Check a constant value and report if it is a string that is
529 * too large.
530 */
531 private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
532 if (nerrs != 0 || // only complain about a long string once
533 constValue == null ||
534 !(constValue instanceof String) ||
535 ((String)constValue).length() < Pool.MAX_STRING_LENGTH)
536 return;
537 log.error(pos, "limit.string");
538 nerrs++;
539 }
540
541 /** Insert instance initializer code into initial constructor.
542 * @param md The tree potentially representing a
543 * constructor's definition.
544 * @param initCode The list of instance initializer statements.
545 * @param initTAs Type annotations from the initializer expression.
546 */
547 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<TypeCompound> initTAs) {
548 if (md.name == names.init && TreeInfo.isInitialConstructor(md)) {
549 // We are seeing a constructor that does not call another
550 // constructor of the same class.
551 List<JCStatement> stats = md.body.stats;
552 ListBuffer<JCStatement> newstats = new ListBuffer<>();
553
554 if (stats.nonEmpty()) {
555 // Copy initializers of synthetic variables generated in
556 // the translation of inner classes.
557 while (TreeInfo.isSyntheticInit(stats.head)) {
558 newstats.append(stats.head);
559 stats = stats.tail;
560 }
561 // Copy superclass constructor call
562 newstats.append(stats.head);
563 stats = stats.tail;
564 // Copy remaining synthetic initializers.
565 while (stats.nonEmpty() &&
566 TreeInfo.isSyntheticInit(stats.head)) {
567 newstats.append(stats.head);
568 stats = stats.tail;
569 }
570 // Now insert the initializer code.
571 newstats.appendList(initCode);
572 // And copy all remaining statements.
573 while (stats.nonEmpty()) {
574 newstats.append(stats.head);
575 stats = stats.tail;
576 }
577 }
578 md.body.stats = newstats.toList();
579 if (md.body.endpos == Position.NOPOS)
580 md.body.endpos = TreeInfo.endPos(md.body.stats.last());
581
582 md.sym.appendUniqueTypeAttributes(initTAs);
583 }
584 }
585
586 /* ************************************************************************
587 * Traversal methods
588 *************************************************************************/
589
590 /** Visitor argument: The current environment.
591 */
592 Env<GenContext> env;
593
594 /** Visitor argument: The expected type (prototype).
595 */
596 Type pt;
597
598 /** Visitor result: The item representing the computed value.
599 */
600 Item result;
601
602 /** Visitor method: generate code for a definition, catching and reporting
603 * any completion failures.
604 * @param tree The definition to be visited.
605 * @param env The environment current at the definition.
606 */
607 public void genDef(JCTree tree, Env<GenContext> env) {
608 Env<GenContext> prevEnv = this.env;
609 try {
610 this.env = env;
611 tree.accept(this);
612 } catch (CompletionFailure ex) {
613 chk.completionError(tree.pos(), ex);
614 } finally {
615 this.env = prevEnv;
616 }
617 }
618
619 /** Derived visitor method: check whether CharacterRangeTable
620 * should be emitted, if so, put a new entry into CRTable
621 * and call method to generate bytecode.
622 * If not, just call method to generate bytecode.
623 * @see #genStat(JCTree, Env)
624 *
625 * @param tree The tree to be visited.
626 * @param env The environment to use.
627 * @param crtFlags The CharacterRangeTable flags
628 * indicating type of the entry.
629 */
630 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
631 if (!genCrt) {
632 genStat(tree, env);
633 return;
634 }
635 int startpc = code.curCP();
636 genStat(tree, env);
637 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK;
638 code.crt.put(tree, crtFlags, startpc, code.curCP());
639 }
640
641 /** Derived visitor method: generate code for a statement.
642 */
643 public void genStat(JCTree tree, Env<GenContext> env) {
644 if (code.isAlive()) {
645 code.statBegin(tree.pos);
646 genDef(tree, env);
647 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) {
648 // variables whose declarations are in a switch
649 // can be used even if the decl is unreachable.
650 code.newLocal(((JCVariableDecl) tree).sym);
651 }
652 }
653
654 /** Derived visitor method: check whether CharacterRangeTable
655 * should be emitted, if so, put a new entry into CRTable
656 * and call method to generate bytecode.
657 * If not, just call method to generate bytecode.
658 * @see #genStats(List, Env)
659 *
660 * @param trees The list of trees to be visited.
661 * @param env The environment to use.
662 * @param crtFlags The CharacterRangeTable flags
663 * indicating type of the entry.
664 */
665 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
666 if (!genCrt) {
667 genStats(trees, env);
668 return;
669 }
670 if (trees.length() == 1) { // mark one statement with the flags
671 genStat(trees.head, env, crtFlags | CRT_STATEMENT);
672 } else {
673 int startpc = code.curCP();
674 genStats(trees, env);
675 code.crt.put(trees, crtFlags, startpc, code.curCP());
676 }
677 }
678
679 /** Derived visitor method: generate code for a list of statements.
680 */
681 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) {
682 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
683 genStat(l.head, env, CRT_STATEMENT);
684 }
685
686 /** Derived visitor method: check whether CharacterRangeTable
687 * should be emitted, if so, put a new entry into CRTable
688 * and call method to generate bytecode.
689 * If not, just call method to generate bytecode.
690 * @see #genCond(JCTree,boolean)
691 *
692 * @param tree The tree to be visited.
693 * @param crtFlags The CharacterRangeTable flags
694 * indicating type of the entry.
695 */
696 public CondItem genCond(JCTree tree, int crtFlags) {
697 if (!genCrt) return genCond(tree, false);
698 int startpc = code.curCP();
699 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
700 code.crt.put(tree, crtFlags, startpc, code.curCP());
701 return item;
702 }
703
704 /** Derived visitor method: generate code for a boolean
705 * expression in a control-flow context.
706 * @param _tree The expression to be visited.
707 * @param markBranches The flag to indicate that the condition is
708 * a flow controller so produced conditions
709 * should contain a proper tree to generate
710 * CharacterRangeTable branches for them.
711 */
712 public CondItem genCond(JCTree _tree, boolean markBranches) {
713 JCTree inner_tree = TreeInfo.skipParens(_tree);
714 if (inner_tree.hasTag(CONDEXPR)) {
715 JCConditional tree = (JCConditional)inner_tree;
716 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
717 if (cond.isTrue()) {
718 code.resolve(cond.trueJumps);
719 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
720 if (markBranches) result.tree = tree.truepart;
721 return result;
722 }
723 if (cond.isFalse()) {
724 code.resolve(cond.falseJumps);
725 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
726 if (markBranches) result.tree = tree.falsepart;
727 return result;
728 }
729 Chain secondJumps = cond.jumpFalse();
730 code.resolve(cond.trueJumps);
731 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
732 if (markBranches) first.tree = tree.truepart;
733 Chain falseJumps = first.jumpFalse();
734 code.resolve(first.trueJumps);
735 Chain trueJumps = code.branch(goto_);
736 code.resolve(secondJumps);
737 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
738 CondItem result = items.makeCondItem(second.opcode,
739 Code.mergeChains(trueJumps, second.trueJumps),
740 Code.mergeChains(falseJumps, second.falseJumps));
741 if (markBranches) result.tree = tree.falsepart;
742 return result;
743 } else {
744 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
745 if (markBranches) result.tree = _tree;
746 return result;
747 }
748 }
749
750 /** Visitor class for expressions which might be constant expressions.
751 * This class is a subset of TreeScanner. Intended to visit trees pruned by
752 * Lower as long as constant expressions looking for references to any
753 * ClassSymbol. Any such reference will be added to the constant pool so
754 * automated tools can detect class dependencies better.
755 */
756 class ClassReferenceVisitor extends JCTree.Visitor {
757
758 @Override
759 public void visitTree(JCTree tree) {}
760
761 @Override
762 public void visitBinary(JCBinary tree) {
763 tree.lhs.accept(this);
764 tree.rhs.accept(this);
765 }
766
767 @Override
768 public void visitSelect(JCFieldAccess tree) {
769 if (tree.selected.type.hasTag(CLASS)) {
770 makeRef(tree.selected.pos(), tree.selected.type);
771 }
772 }
773
774 @Override
775 public void visitIdent(JCIdent tree) {
776 if (tree.sym.owner instanceof ClassSymbol) {
777 pool.put(tree.sym.owner);
778 }
779 }
780
781 @Override
782 public void visitConditional(JCConditional tree) {
783 tree.cond.accept(this);
784 tree.truepart.accept(this);
785 tree.falsepart.accept(this);
786 }
787
788 @Override
789 public void visitUnary(JCUnary tree) {
790 tree.arg.accept(this);
791 }
792
793 @Override
794 public void visitParens(JCParens tree) {
795 tree.expr.accept(this);
796 }
797
798 @Override
799 public void visitTypeCast(JCTypeCast tree) {
800 tree.expr.accept(this);
801 }
802 }
803
804 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor();
805
806 /** Visitor method: generate code for an expression, catching and reporting
807 * any completion failures.
808 * @param tree The expression to be visited.
809 * @param pt The expression's expected type (proto-type).
810 */
811 public Item genExpr(JCTree tree, Type pt) {
812 Type prevPt = this.pt;
813 try {
814 if (tree.type.constValue() != null) {
815 // Short circuit any expressions which are constants
816 tree.accept(classReferenceVisitor);
817 checkStringConstant(tree.pos(), tree.type.constValue());
818 result = items.makeImmediateItem(tree.type, tree.type.constValue());
819 } else {
820 this.pt = pt;
821 tree.accept(this);
822 }
823 return result.coerce(pt);
824 } catch (CompletionFailure ex) {
825 chk.completionError(tree.pos(), ex);
826 code.state.stacksize = 1;
827 return items.makeStackItem(pt);
828 } finally {
829 this.pt = prevPt;
830 }
831 }
832
833 /** Derived visitor method: generate code for a list of method arguments.
834 * @param trees The argument expressions to be visited.
835 * @param pts The expression's expected types (i.e. the formal parameter
836 * types of the invoked method).
837 */
838 public void genArgs(List<JCExpression> trees, List<Type> pts) {
839 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
840 genExpr(l.head, pts.head).load();
841 pts = pts.tail;
842 }
843 // require lists be of same length
844 Assert.check(pts.isEmpty());
845 }
846
847 /* ************************************************************************
848 * Visitor methods for statements and definitions
849 *************************************************************************/
850
851 /** Thrown when the byte code size exceeds limit.
852 */
853 public static class CodeSizeOverflow extends RuntimeException {
854 private static final long serialVersionUID = 0;
855 public CodeSizeOverflow() {}
856 }
857
858 public void visitMethodDef(JCMethodDecl tree) {
859 // Create a new local environment that points pack at method
860 // definition.
861 Env<GenContext> localEnv = env.dup(tree);
862 localEnv.enclMethod = tree;
863 // The expected type of every return statement in this method
864 // is the method's return type.
865 this.pt = tree.sym.erasure(types).getReturnType();
866
867 checkDimension(tree.pos(), tree.sym.erasure(types));
868 genMethod(tree, localEnv, false);
869 }
870 //where
871 /** Generate code for a method.
872 * @param tree The tree representing the method definition.
873 * @param env The environment current for the method body.
874 * @param fatcode A flag that indicates whether all jumps are
875 * within 32K. We first invoke this method under
876 * the assumption that fatcode == false, i.e. all
877 * jumps are within 32K. If this fails, fatcode
878 * is set to true and we try again.
879 */
880 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
881 MethodSymbol meth = tree.sym;
882 int extras = 0;
883 // Count up extra parameters
884 if (meth.isConstructor()) {
885 extras++;
886 if (meth.enclClass().isInner() &&
887 !meth.enclClass().isStatic()) {
888 extras++;
889 }
890 } else if ((tree.mods.flags & STATIC) == 0) {
891 extras++;
892 }
893 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
894 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
895 ClassFile.MAX_PARAMETERS) {
896 log.error(tree.pos(), "limit.parameters");
897 nerrs++;
898 }
899
900 else if (tree.body != null) {
901 // Create a new code structure and initialize it.
902 int startpcCrt = initCode(tree, env, fatcode);
903
904 try {
905 genStat(tree.body, env);
906 } catch (CodeSizeOverflow e) {
907 // Failed due to code limit, try again with jsr/ret
908 startpcCrt = initCode(tree, env, fatcode);
909 genStat(tree.body, env);
910 }
911
912 if (code.state.stacksize != 0) {
913 log.error(tree.body.pos(), "stack.sim.error", tree);
914 throw new AssertionError();
915 }
916
917 // If last statement could complete normally, insert a
918 // return at the end.
919 if (code.isAlive()) {
920 code.statBegin(TreeInfo.endPos(tree.body));
921 if (env.enclMethod == null ||
922 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
923 code.emitop0(return_);
924 } else {
925 // sometime dead code seems alive (4415991);
926 // generate a small loop instead
927 int startpc = code.entryPoint();
928 CondItem c = items.makeCondItem(goto_);
929 code.resolve(c.jumpTrue(), startpc);
930 }
931 }
932 if (genCrt)
933 code.crt.put(tree.body,
934 CRT_BLOCK,
935 startpcCrt,
936 code.curCP());
937
938 code.endScopes(0);
939
940 // If we exceeded limits, panic
941 if (code.checkLimits(tree.pos(), log)) {
942 nerrs++;
943 return;
944 }
945
946 // If we generated short code but got a long jump, do it again
947 // with fatCode = true.
948 if (!fatcode && code.fatcode) genMethod(tree, env, true);
949
950 // Clean up
951 if(stackMap == StackMapFormat.JSR202) {
952 code.lastFrame = null;
953 code.frameBeforeLast = null;
954 }
955
956 // Compress exception table
957 code.compressCatchTable();
958
959 // Fill in type annotation positions for exception parameters
960 code.fillExceptionParameterPositions();
961 }
962 }
963
964 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
965 MethodSymbol meth = tree.sym;
966
967 // Create a new code structure.
968 meth.code = code = new Code(meth,
969 fatcode,
970 lineDebugInfo ? toplevel.lineMap : null,
971 varDebugInfo,
972 stackMap,
973 debugCode,
974 genCrt ? new CRTable(tree, env.toplevel.endPositions)
975 : null,
976 syms,
977 types,
978 pool);
979 items = new Items(pool, code, syms, types);
980 if (code.debugCode) {
981 System.err.println(meth + " for body " + tree);
982 }
983
984 // If method is not static, create a new local variable address
985 // for `this'.
986 if ((tree.mods.flags & STATIC) == 0) {
987 Type selfType = meth.owner.type;
988 if (meth.isConstructor() && selfType != syms.objectType)
989 selfType = UninitializedType.uninitializedThis(selfType);
990 code.setDefined(
991 code.newLocal(
992 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
993 }
994
995 // Mark all parameters as defined from the beginning of
996 // the method.
997 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
998 checkDimension(l.head.pos(), l.head.sym.type);
999 code.setDefined(code.newLocal(l.head.sym));
1000 }
1001
1002 // Get ready to generate code for method body.
1003 int startpcCrt = genCrt ? code.curCP() : 0;
1004 code.entryPoint();
1005
1006 // Suppress initial stackmap
1007 code.pendingStackMap = false;
1008
1009 return startpcCrt;
1010 }
1011
1012 public void visitVarDef(JCVariableDecl tree) {
1013 VarSymbol v = tree.sym;
1014 code.newLocal(v);
1015 if (tree.init != null) {
1016 checkStringConstant(tree.init.pos(), v.getConstValue());
1017 if (v.getConstValue() == null || varDebugInfo) {
1018 genExpr(tree.init, v.erasure(types)).load();
1019 items.makeLocalItem(v).store();
1020 }
1021 }
1022 checkDimension(tree.pos(), v.type);
1023 }
1024
1025 public void visitSkip(JCSkip tree) {
1026 }
1027
1028 public void visitBlock(JCBlock tree) {
1029 int limit = code.nextreg;
1030 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1031 genStats(tree.stats, localEnv);
1032 // End the scope of all block-local variables in variable info.
1033 if (!env.tree.hasTag(METHODDEF)) {
1034 code.statBegin(tree.endpos);
1035 code.endScopes(limit);
1036 code.pendingStatPos = Position.NOPOS;
1037 }
1038 }
1039
1040 public void visitDoLoop(JCDoWhileLoop tree) {
1041 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), false);
1042 }
1043
1044 public void visitWhileLoop(JCWhileLoop tree) {
1045 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), true);
1046 }
1047
1048 public void visitForLoop(JCForLoop tree) {
1049 int limit = code.nextreg;
1050 genStats(tree.init, env);
1051 genLoop(tree, tree.body, tree.cond, tree.step, true);
1052 code.endScopes(limit);
1053 }
1054 //where
1055 /** Generate code for a loop.
1056 * @param loop The tree representing the loop.
1057 * @param body The loop's body.
1058 * @param cond The loop's controling condition.
1059 * @param step "Step" statements to be inserted at end of
1060 * each iteration.
1061 * @param testFirst True if the loop test belongs before the body.
1062 */
1063 private void genLoop(JCStatement loop,
1064 JCStatement body,
1065 JCExpression cond,
1066 List<JCExpressionStatement> step,
1067 boolean testFirst) {
1068 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1069 int startpc = code.entryPoint();
1070 if (testFirst) { //while or for loop
1071 CondItem c;
1072 if (cond != null) {
1073 code.statBegin(cond.pos);
1074 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1075 } else {
1076 c = items.makeCondItem(goto_);
1077 }
1078 Chain loopDone = c.jumpFalse();
1079 code.resolve(c.trueJumps);
1080 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1081 code.resolve(loopEnv.info.cont);
1082 genStats(step, loopEnv);
1083 code.resolve(code.branch(goto_), startpc);
1084 code.resolve(loopDone);
1085 } else {
1086 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1087 code.resolve(loopEnv.info.cont);
1088 genStats(step, loopEnv);
1089 CondItem c;
1090 if (cond != null) {
1091 code.statBegin(cond.pos);
1092 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1093 } else {
1094 c = items.makeCondItem(goto_);
1095 }
1096 code.resolve(c.jumpTrue(), startpc);
1097 code.resolve(c.falseJumps);
1098 }
1099 Chain exit = loopEnv.info.exit;
1100 if (exit != null) {
1101 code.resolve(exit);
1102 exit.state.defined.excludeFrom(code.nextreg);
1103 }
1104 }
1105
1106 public void visitForeachLoop(JCEnhancedForLoop tree) {
1107 throw new AssertionError(); // should have been removed by Lower.
1108 }
1109
1110 public void visitLabelled(JCLabeledStatement tree) {
1111 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1112 genStat(tree.body, localEnv, CRT_STATEMENT);
1113 Chain exit = localEnv.info.exit;
1114 if (exit != null) {
1115 code.resolve(exit);
1116 exit.state.defined.excludeFrom(code.nextreg);
1117 }
1118 }
1119
1120 public void visitSwitch(JCSwitch tree) {
1121 int limit = code.nextreg;
1122 Assert.check(!tree.selector.type.hasTag(CLASS));
1123 int startpcCrt = genCrt ? code.curCP() : 0;
1124 Item sel = genExpr(tree.selector, syms.intType);
1125 List<JCCase> cases = tree.cases;
1126 if (cases.isEmpty()) {
1127 // We are seeing: switch <sel> {}
1128 sel.load().drop();
1129 if (genCrt)
1130 code.crt.put(TreeInfo.skipParens(tree.selector),
1131 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1132 } else {
1133 // We are seeing a nonempty switch.
1134 sel.load();
1135 if (genCrt)
1136 code.crt.put(TreeInfo.skipParens(tree.selector),
1137 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1138 Env<GenContext> switchEnv = env.dup(tree, new GenContext());
1139 switchEnv.info.isSwitch = true;
1140
1141 // Compute number of labels and minimum and maximum label values.
1142 // For each case, store its label in an array.
1143 int lo = Integer.MAX_VALUE; // minimum label.
1144 int hi = Integer.MIN_VALUE; // maximum label.
1145 int nlabels = 0; // number of labels.
1146
1147 int[] labels = new int[cases.length()]; // the label array.
1148 int defaultIndex = -1; // the index of the default clause.
1149
1150 List<JCCase> l = cases;
1151 for (int i = 0; i < labels.length; i++) {
1152 if (l.head.pat != null) {
1153 int val = ((Number)l.head.pat.type.constValue()).intValue();
1154 labels[i] = val;
1155 if (val < lo) lo = val;
1156 if (hi < val) hi = val;
1157 nlabels++;
1158 } else {
1159 Assert.check(defaultIndex == -1);
1160 defaultIndex = i;
1161 }
1162 l = l.tail;
1163 }
1164
1165 // Determine whether to issue a tableswitch or a lookupswitch
1166 // instruction.
1167 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1168 long table_time_cost = 3; // comparisons
1169 long lookup_space_cost = 3 + 2 * (long) nlabels;
1170 long lookup_time_cost = nlabels;
1171 int opcode =
1172 nlabels > 0 &&
1173 table_space_cost + 3 * table_time_cost <=
1174 lookup_space_cost + 3 * lookup_time_cost
1175 ?
1176 tableswitch : lookupswitch;
1177
1178 int startpc = code.curCP(); // the position of the selector operation
1179 code.emitop0(opcode);
1180 code.align(4);
1181 int tableBase = code.curCP(); // the start of the jump table
1182 int[] offsets = null; // a table of offsets for a lookupswitch
1183 code.emit4(-1); // leave space for default offset
1184 if (opcode == tableswitch) {
1185 code.emit4(lo); // minimum label
1186 code.emit4(hi); // maximum label
1187 for (long i = lo; i <= hi; i++) { // leave space for jump table
1188 code.emit4(-1);
1189 }
1190 } else {
1191 code.emit4(nlabels); // number of labels
1192 for (int i = 0; i < nlabels; i++) {
1193 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1194 }
1195 offsets = new int[labels.length];
1196 }
1197 Code.State stateSwitch = code.state.dup();
1198 code.markDead();
1199
1200 // For each case do:
1201 l = cases;
1202 for (int i = 0; i < labels.length; i++) {
1203 JCCase c = l.head;
1204 l = l.tail;
1205
1206 int pc = code.entryPoint(stateSwitch);
1207 // Insert offset directly into code or else into the
1208 // offsets table.
1209 if (i != defaultIndex) {
1210 if (opcode == tableswitch) {
1211 code.put4(
1212 tableBase + 4 * (labels[i] - lo + 3),
1213 pc - startpc);
1214 } else {
1215 offsets[i] = pc - startpc;
1216 }
1217 } else {
1218 code.put4(tableBase, pc - startpc);
1219 }
1220
1221 // Generate code for the statements in this case.
1222 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1223 }
1224
1225 // Resolve all breaks.
1226 Chain exit = switchEnv.info.exit;
1227 if (exit != null) {
1228 code.resolve(exit);
1229 exit.state.defined.excludeFrom(code.nextreg);
1230 }
1231
1232 // If we have not set the default offset, we do so now.
1233 if (code.get4(tableBase) == -1) {
1234 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1235 }
1236
1237 if (opcode == tableswitch) {
1238 // Let any unfilled slots point to the default case.
1239 int defaultOffset = code.get4(tableBase);
1240 for (long i = lo; i <= hi; i++) {
1241 int t = (int)(tableBase + 4 * (i - lo + 3));
1242 if (code.get4(t) == -1)
1243 code.put4(t, defaultOffset);
1244 }
1245 } else {
1246 // Sort non-default offsets and copy into lookup table.
1247 if (defaultIndex >= 0)
1248 for (int i = defaultIndex; i < labels.length - 1; i++) {
1249 labels[i] = labels[i+1];
1250 offsets[i] = offsets[i+1];
1251 }
1252 if (nlabels > 0)
1253 qsort2(labels, offsets, 0, nlabels - 1);
1254 for (int i = 0; i < nlabels; i++) {
1255 int caseidx = tableBase + 8 * (i + 1);
1256 code.put4(caseidx, labels[i]);
1257 code.put4(caseidx + 4, offsets[i]);
1258 }
1259 }
1260 }
1261 code.endScopes(limit);
1262 }
1263 //where
1264 /** Sort (int) arrays of keys and values
1265 */
1266 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1267 int i = lo;
1268 int j = hi;
1269 int pivot = keys[(i+j)/2];
1270 do {
1271 while (keys[i] < pivot) i++;
1272 while (pivot < keys[j]) j--;
1273 if (i <= j) {
1274 int temp1 = keys[i];
1275 keys[i] = keys[j];
1276 keys[j] = temp1;
1277 int temp2 = values[i];
1278 values[i] = values[j];
1279 values[j] = temp2;
1280 i++;
1281 j--;
1282 }
1283 } while (i <= j);
1284 if (lo < j) qsort2(keys, values, lo, j);
1285 if (i < hi) qsort2(keys, values, i, hi);
1286 }
1287
1288 public void visitSynchronized(JCSynchronized tree) {
1289 int limit = code.nextreg;
1290 // Generate code to evaluate lock and save in temporary variable.
1291 final LocalItem lockVar = makeTemp(syms.objectType);
1292 genExpr(tree.lock, tree.lock.type).load().duplicate();
1293 lockVar.store();
1294
1295 // Generate code to enter monitor.
1296 code.emitop0(monitorenter);
1297 code.state.lock(lockVar.reg);
1298
1299 // Generate code for a try statement with given body, no catch clauses
1300 // in a new environment with the "exit-monitor" operation as finalizer.
1301 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1302 syncEnv.info.finalize = new GenFinalizer() {
1303 void gen() {
1304 genLast();
1305 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1306 syncEnv.info.gaps.append(code.curCP());
1307 }
1308 void genLast() {
1309 if (code.isAlive()) {
1310 lockVar.load();
1311 code.emitop0(monitorexit);
1312 code.state.unlock(lockVar.reg);
1313 }
1314 }
1315 };
1316 syncEnv.info.gaps = new ListBuffer<>();
1317 genTry(tree.body, List.<JCCatch>nil(), syncEnv);
1318 code.endScopes(limit);
1319 }
1320
1321 public void visitTry(final JCTry tree) {
1322 // Generate code for a try statement with given body and catch clauses,
1323 // in a new environment which calls the finally block if there is one.
1324 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1325 final Env<GenContext> oldEnv = env;
1326 if (!useJsrLocally) {
1327 useJsrLocally =
1328 (stackMap == StackMapFormat.NONE) &&
1329 (jsrlimit <= 0 ||
1330 jsrlimit < 100 &&
1331 estimateCodeComplexity(tree.finalizer)>jsrlimit);
1332 }
1333 tryEnv.info.finalize = new GenFinalizer() {
1334 void gen() {
1335 if (useJsrLocally) {
1336 if (tree.finalizer != null) {
1337 Code.State jsrState = code.state.dup();
1338 jsrState.push(Code.jsrReturnValue);
1339 tryEnv.info.cont =
1340 new Chain(code.emitJump(jsr),
1341 tryEnv.info.cont,
1342 jsrState);
1343 }
1344 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1345 tryEnv.info.gaps.append(code.curCP());
1346 } else {
1347 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1348 tryEnv.info.gaps.append(code.curCP());
1349 genLast();
1350 }
1351 }
1352 void genLast() {
1353 if (tree.finalizer != null)
1354 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1355 }
1356 boolean hasFinalizer() {
1357 return tree.finalizer != null;
1358 }
1359 };
1360 tryEnv.info.gaps = new ListBuffer<>();
1361 genTry(tree.body, tree.catchers, tryEnv);
1362 }
1363 //where
1364 /** Generate code for a try or synchronized statement
1365 * @param body The body of the try or synchronized statement.
1366 * @param catchers The lis of catch clauses.
1367 * @param env the environment current for the body.
1368 */
1369 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1370 int limit = code.nextreg;
1371 int startpc = code.curCP();
1372 Code.State stateTry = code.state.dup();
1373 genStat(body, env, CRT_BLOCK);
1374 int endpc = code.curCP();
1375 boolean hasFinalizer =
1376 env.info.finalize != null &&
1377 env.info.finalize.hasFinalizer();
1378 List<Integer> gaps = env.info.gaps.toList();
1379 code.statBegin(TreeInfo.endPos(body));
1380 genFinalizer(env);
1381 code.statBegin(TreeInfo.endPos(env.tree));
1382 Chain exitChain = code.branch(goto_);
1383 endFinalizerGap(env);
1384 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1385 // start off with exception on stack
1386 code.entryPoint(stateTry, l.head.param.sym.type);
1387 genCatch(l.head, env, startpc, endpc, gaps);
1388 genFinalizer(env);
1389 if (hasFinalizer || l.tail.nonEmpty()) {
1390 code.statBegin(TreeInfo.endPos(env.tree));
1391 exitChain = Code.mergeChains(exitChain,
1392 code.branch(goto_));
1393 }
1394 endFinalizerGap(env);
1395 }
1396 if (hasFinalizer) {
1397 // Create a new register segement to avoid allocating
1398 // the same variables in finalizers and other statements.
1399 code.newRegSegment();
1400
1401 // Add a catch-all clause.
1402
1403 // start off with exception on stack
1404 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1405
1406 // Register all exception ranges for catch all clause.
1407 // The range of the catch all clause is from the beginning
1408 // of the try or synchronized block until the present
1409 // code pointer excluding all gaps in the current
1410 // environment's GenContext.
1411 int startseg = startpc;
1412 while (env.info.gaps.nonEmpty()) {
1413 int endseg = env.info.gaps.next().intValue();
1414 registerCatch(body.pos(), startseg, endseg,
1415 catchallpc, 0);
1416 startseg = env.info.gaps.next().intValue();
1417 }
1418 code.statBegin(TreeInfo.finalizerPos(env.tree));
1419 code.markStatBegin();
1420
1421 Item excVar = makeTemp(syms.throwableType);
1422 excVar.store();
1423 genFinalizer(env);
1424 excVar.load();
1425 registerCatch(body.pos(), startseg,
1426 env.info.gaps.next().intValue(),
1427 catchallpc, 0);
1428 code.emitop0(athrow);
1429 code.markDead();
1430
1431 // If there are jsr's to this finalizer, ...
1432 if (env.info.cont != null) {
1433 // Resolve all jsr's.
1434 code.resolve(env.info.cont);
1435
1436 // Mark statement line number
1437 code.statBegin(TreeInfo.finalizerPos(env.tree));
1438 code.markStatBegin();
1439
1440 // Save return address.
1441 LocalItem retVar = makeTemp(syms.throwableType);
1442 retVar.store();
1443
1444 // Generate finalizer code.
1445 env.info.finalize.genLast();
1446
1447 // Return.
1448 code.emitop1w(ret, retVar.reg);
1449 code.markDead();
1450 }
1451 }
1452 // Resolve all breaks.
1453 code.resolve(exitChain);
1454
1455 code.endScopes(limit);
1456 }
1457
1458 /** Generate code for a catch clause.
1459 * @param tree The catch clause.
1460 * @param env The environment current in the enclosing try.
1461 * @param startpc Start pc of try-block.
1462 * @param endpc End pc of try-block.
1463 */
1464 void genCatch(JCCatch tree,
1465 Env<GenContext> env,
1466 int startpc, int endpc,
1467 List<Integer> gaps) {
1468 if (startpc != endpc) {
1469 List<JCExpression> subClauses = TreeInfo.isMultiCatch(tree) ?
1470 ((JCTypeUnion)tree.param.vartype).alternatives :
1471 List.of(tree.param.vartype);
1472 while (gaps.nonEmpty()) {
1473 for (JCExpression subCatch : subClauses) {
1474 int catchType = makeRef(tree.pos(), subCatch.type);
1475 int end = gaps.head.intValue();
1476 registerCatch(tree.pos(),
1477 startpc, end, code.curCP(),
1478 catchType);
1479 if (subCatch.type.isAnnotated()) {
1480 for (Attribute.TypeCompound tc :
1481 subCatch.type.getAnnotationMirrors()) {
1482 tc.position.setCatchInfo(catchType, startpc);
1483 }
1484 }
1485 }
1486 gaps = gaps.tail;
1487 startpc = gaps.head.intValue();
1488 gaps = gaps.tail;
1489 }
1490 if (startpc < endpc) {
1491 for (JCExpression subCatch : subClauses) {
1492 int catchType = makeRef(tree.pos(), subCatch.type);
1493 registerCatch(tree.pos(),
1494 startpc, endpc, code.curCP(),
1495 catchType);
1496 if (subCatch.type.isAnnotated()) {
1497 for (Attribute.TypeCompound tc :
1498 subCatch.type.getAnnotationMirrors()) {
1499 tc.position.setCatchInfo(catchType, startpc);
1500 }
1501 }
1502 }
1503 }
1504 VarSymbol exparam = tree.param.sym;
1505 code.statBegin(tree.pos);
1506 code.markStatBegin();
1507 int limit = code.nextreg;
1508 int exlocal = code.newLocal(exparam);
1509 items.makeLocalItem(exparam).store();
1510 code.statBegin(TreeInfo.firstStatPos(tree.body));
1511 genStat(tree.body, env, CRT_BLOCK);
1512 code.endScopes(limit);
1513 code.statBegin(TreeInfo.endPos(tree.body));
1514 }
1515 }
1516
1517 /** Register a catch clause in the "Exceptions" code-attribute.
1518 */
1519 void registerCatch(DiagnosticPosition pos,
1520 int startpc, int endpc,
1521 int handler_pc, int catch_type) {
1522 char startpc1 = (char)startpc;
1523 char endpc1 = (char)endpc;
1524 char handler_pc1 = (char)handler_pc;
1525 if (startpc1 == startpc &&
1526 endpc1 == endpc &&
1527 handler_pc1 == handler_pc) {
1528 code.addCatch(startpc1, endpc1, handler_pc1,
1529 (char)catch_type);
1530 } else {
1531 log.error(pos, "limit.code.too.large.for.try.stmt");
1532 nerrs++;
1533 }
1534 }
1535
1536 /** Very roughly estimate the number of instructions needed for
1537 * the given tree.
1538 */
1539 int estimateCodeComplexity(JCTree tree) {
1540 if (tree == null) return 0;
1541 class ComplexityScanner extends TreeScanner {
1542 int complexity = 0;
1543 public void scan(JCTree tree) {
1544 if (complexity > jsrlimit) return;
1545 super.scan(tree);
1546 }
1547 public void visitClassDef(JCClassDecl tree) {}
1548 public void visitDoLoop(JCDoWhileLoop tree)
1549 { super.visitDoLoop(tree); complexity++; }
1550 public void visitWhileLoop(JCWhileLoop tree)
1551 { super.visitWhileLoop(tree); complexity++; }
1552 public void visitForLoop(JCForLoop tree)
1553 { super.visitForLoop(tree); complexity++; }
1554 public void visitSwitch(JCSwitch tree)
1555 { super.visitSwitch(tree); complexity+=5; }
1556 public void visitCase(JCCase tree)
1557 { super.visitCase(tree); complexity++; }
1558 public void visitSynchronized(JCSynchronized tree)
1559 { super.visitSynchronized(tree); complexity+=6; }
1560 public void visitTry(JCTry tree)
1561 { super.visitTry(tree);
1562 if (tree.finalizer != null) complexity+=6; }
1563 public void visitCatch(JCCatch tree)
1564 { super.visitCatch(tree); complexity+=2; }
1565 public void visitConditional(JCConditional tree)
1566 { super.visitConditional(tree); complexity+=2; }
1567 public void visitIf(JCIf tree)
1568 { super.visitIf(tree); complexity+=2; }
1569 // note: for break, continue, and return we don't take unwind() into account.
1570 public void visitBreak(JCBreak tree)
1571 { super.visitBreak(tree); complexity+=1; }
1572 public void visitContinue(JCContinue tree)
1573 { super.visitContinue(tree); complexity+=1; }
1574 public void visitReturn(JCReturn tree)
1575 { super.visitReturn(tree); complexity+=1; }
1576 public void visitThrow(JCThrow tree)
1577 { super.visitThrow(tree); complexity+=1; }
1578 public void visitAssert(JCAssert tree)
1579 { super.visitAssert(tree); complexity+=5; }
1580 public void visitApply(JCMethodInvocation tree)
1581 { super.visitApply(tree); complexity+=2; }
1582 public void visitNewClass(JCNewClass tree)
1583 { scan(tree.encl); scan(tree.args); complexity+=2; }
1584 public void visitNewArray(JCNewArray tree)
1585 { super.visitNewArray(tree); complexity+=5; }
1586 public void visitAssign(JCAssign tree)
1587 { super.visitAssign(tree); complexity+=1; }
1588 public void visitAssignop(JCAssignOp tree)
1589 { super.visitAssignop(tree); complexity+=2; }
1590 public void visitUnary(JCUnary tree)
1591 { complexity+=1;
1592 if (tree.type.constValue() == null) super.visitUnary(tree); }
1593 public void visitBinary(JCBinary tree)
1594 { complexity+=1;
1595 if (tree.type.constValue() == null) super.visitBinary(tree); }
1596 public void visitTypeTest(JCInstanceOf tree)
1597 { super.visitTypeTest(tree); complexity+=1; }
1598 public void visitIndexed(JCArrayAccess tree)
1599 { super.visitIndexed(tree); complexity+=1; }
1600 public void visitSelect(JCFieldAccess tree)
1601 { super.visitSelect(tree);
1602 if (tree.sym.kind == VAR) complexity+=1; }
1603 public void visitIdent(JCIdent tree) {
1604 if (tree.sym.kind == VAR) {
1605 complexity+=1;
1606 if (tree.type.constValue() == null &&
1607 tree.sym.owner.kind == TYP)
1608 complexity+=1;
1609 }
1610 }
1611 public void visitLiteral(JCLiteral tree)
1612 { complexity+=1; }
1613 public void visitTree(JCTree tree) {}
1614 public void visitWildcard(JCWildcard tree) {
1615 throw new AssertionError(this.getClass().getName());
1616 }
1617 }
1618 ComplexityScanner scanner = new ComplexityScanner();
1619 tree.accept(scanner);
1620 return scanner.complexity;
1621 }
1622
1623 public void visitIf(JCIf tree) {
1624 int limit = code.nextreg;
1625 Chain thenExit = null;
1626 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1627 CRT_FLOW_CONTROLLER);
1628 Chain elseChain = c.jumpFalse();
1629 if (!c.isFalse()) {
1630 code.resolve(c.trueJumps);
1631 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1632 thenExit = code.branch(goto_);
1633 }
1634 if (elseChain != null) {
1635 code.resolve(elseChain);
1636 if (tree.elsepart != null) {
1637 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1638 }
1639 }
1640 code.resolve(thenExit);
1641 code.endScopes(limit);
1642 }
1643
1644 public void visitExec(JCExpressionStatement tree) {
1645 // Optimize x++ to ++x and x-- to --x.
1646 JCExpression e = tree.expr;
1647 switch (e.getTag()) {
1648 case POSTINC:
1649 ((JCUnary) e).setTag(PREINC);
1650 break;
1651 case POSTDEC:
1652 ((JCUnary) e).setTag(PREDEC);
1653 break;
1654 }
1655 genExpr(tree.expr, tree.expr.type).drop();
1656 }
1657
1658 public void visitBreak(JCBreak tree) {
1659 Env<GenContext> targetEnv = unwind(tree.target, env);
1660 Assert.check(code.state.stacksize == 0);
1661 targetEnv.info.addExit(code.branch(goto_));
1662 endFinalizerGaps(env, targetEnv);
1663 }
1664
1665 public void visitContinue(JCContinue tree) {
1666 Env<GenContext> targetEnv = unwind(tree.target, env);
1667 Assert.check(code.state.stacksize == 0);
1668 targetEnv.info.addCont(code.branch(goto_));
1669 endFinalizerGaps(env, targetEnv);
1670 }
1671
1672 public void visitReturn(JCReturn tree) {
1673 int limit = code.nextreg;
1674 final Env<GenContext> targetEnv;
1675 if (tree.expr != null) {
1676 Item r = genExpr(tree.expr, pt).load();
1677 if (hasFinally(env.enclMethod, env)) {
1678 r = makeTemp(pt);
1679 r.store();
1680 }
1681 targetEnv = unwind(env.enclMethod, env);
1682 r.load();
1683 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
1684 } else {
1685 /* If we have a statement like:
1686 *
1687 * return;
1688 *
1689 * we need to store the code.pendingStatPos value before generating
1690 * the finalizer.
1691 */
1692 int tmpPos = code.pendingStatPos;
1693 targetEnv = unwind(env.enclMethod, env);
1694 code.pendingStatPos = tmpPos;
1695 code.emitop0(return_);
1696 }
1697 endFinalizerGaps(env, targetEnv);
1698 code.endScopes(limit);
1699 }
1700
1701 public void visitThrow(JCThrow tree) {
1702 genExpr(tree.expr, tree.expr.type).load();
1703 code.emitop0(athrow);
1704 }
1705
1706 /* ************************************************************************
1707 * Visitor methods for expressions
1708 *************************************************************************/
1709
1710 public void visitApply(JCMethodInvocation tree) {
1711 setTypeAnnotationPositions(tree.pos);
1712 // Generate code for method.
1713 Item m = genExpr(tree.meth, methodType);
1714 // Generate code for all arguments, where the expected types are
1715 // the parameters of the method's external type (that is, any implicit
1716 // outer instance of a super(...) call appears as first parameter).
1717 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
1718 genArgs(tree.args,
1719 msym.externalType(types).getParameterTypes());
1720 if (!msym.isDynamic()) {
1721 code.statBegin(tree.pos);
1722 }
1723 result = m.invoke();
1724 }
1725
1726 public void visitConditional(JCConditional tree) {
1727 Chain thenExit = null;
1728 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
1729 Chain elseChain = c.jumpFalse();
1730 if (!c.isFalse()) {
1731 code.resolve(c.trueJumps);
1732 int startpc = genCrt ? code.curCP() : 0;
1733 code.statBegin(tree.truepart.pos);
1734 genExpr(tree.truepart, pt).load();
1735 code.state.forceStackTop(tree.type);
1736 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
1737 startpc, code.curCP());
1738 thenExit = code.branch(goto_);
1739 }
1740 if (elseChain != null) {
1741 code.resolve(elseChain);
1742 int startpc = genCrt ? code.curCP() : 0;
1743 code.statBegin(tree.falsepart.pos);
1744 genExpr(tree.falsepart, pt).load();
1745 code.state.forceStackTop(tree.type);
1746 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
1747 startpc, code.curCP());
1748 }
1749 code.resolve(thenExit);
1750 result = items.makeStackItem(pt);
1751 }
1752
1753 private void setTypeAnnotationPositions(int treePos) {
1754 MethodSymbol meth = code.meth;
1755 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR
1756 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT;
1757
1758 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
1759 if (ta.hasUnknownPosition())
1760 ta.tryFixPosition();
1761
1762 if (ta.position.matchesPos(treePos))
1763 ta.position.updatePosOffset(code.cp);
1764 }
1765
1766 if (!initOrClinit)
1767 return;
1768
1769 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
1770 if (ta.hasUnknownPosition())
1771 ta.tryFixPosition();
1772
1773 if (ta.position.matchesPos(treePos))
1774 ta.position.updatePosOffset(code.cp);
1775 }
1776
1777 ClassSymbol clazz = meth.enclClass();
1778 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
1779 if (!s.getKind().isField())
1780 continue;
1781
1782 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
1783 if (ta.hasUnknownPosition())
1784 ta.tryFixPosition();
1785
1786 if (ta.position.matchesPos(treePos))
1787 ta.position.updatePosOffset(code.cp);
1788 }
1789 }
1790 }
1791
1792 public void visitNewClass(JCNewClass tree) {
1793 // Enclosing instances or anonymous classes should have been eliminated
1794 // by now.
1795 Assert.check(tree.encl == null && tree.def == null);
1796 setTypeAnnotationPositions(tree.pos);
1797
1798 code.emitop2(new_, makeRef(tree.pos(), tree.type));
1799 code.emitop0(dup);
1800
1801 // Generate code for all arguments, where the expected types are
1802 // the parameters of the constructor's external type (that is,
1803 // any implicit outer instance appears as first parameter).
1804 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
1805
1806 items.makeMemberItem(tree.constructor, true).invoke();
1807 result = items.makeStackItem(tree.type);
1808 }
1809
1810 public void visitNewArray(JCNewArray tree) {
1811 setTypeAnnotationPositions(tree.pos);
1812
1813 if (tree.elems != null) {
1814 Type elemtype = types.elemtype(tree.type);
1815 loadIntConst(tree.elems.length());
1816 Item arr = makeNewArray(tree.pos(), tree.type, 1);
1817 int i = 0;
1818 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
1819 arr.duplicate();
1820 loadIntConst(i);
1821 i++;
1822 genExpr(l.head, elemtype).load();
1823 items.makeIndexedItem(elemtype).store();
1824 }
1825 result = arr;
1826 } else {
1827 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1828 genExpr(l.head, syms.intType).load();
1829 }
1830 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
1831 }
1832 }
1833 //where
1834 /** Generate code to create an array with given element type and number
1835 * of dimensions.
1836 */
1837 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
1838 Type elemtype = types.elemtype(type);
1839 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
1840 log.error(pos, "limit.dimensions");
1841 nerrs++;
1842 }
1843 int elemcode = Code.arraycode(elemtype);
1844 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
1845 code.emitAnewarray(makeRef(pos, elemtype), type);
1846 } else if (elemcode == 1) {
1847 code.emitMultianewarray(ndims, makeRef(pos, type), type);
1848 } else {
1849 code.emitNewarray(elemcode, type);
1850 }
1851 return items.makeStackItem(type);
1852 }
1853
1854 public void visitParens(JCParens tree) {
1855 result = genExpr(tree.expr, tree.expr.type);
1856 }
1857
1858 public void visitAssign(JCAssign tree) {
1859 Item l = genExpr(tree.lhs, tree.lhs.type);
1860 genExpr(tree.rhs, tree.lhs.type).load();
1861 result = items.makeAssignItem(l);
1862 }
1863
1864 public void visitAssignop(JCAssignOp tree) {
1865 OperatorSymbol operator = (OperatorSymbol) tree.operator;
1866 Item l;
1867 if (operator.opcode == string_add) {
1868 // Generate code to make a string buffer
1869 makeStringBuffer(tree.pos());
1870
1871 // Generate code for first string, possibly save one
1872 // copy under buffer
1873 l = genExpr(tree.lhs, tree.lhs.type);
1874 if (l.width() > 0) {
1875 code.emitop0(dup_x1 + 3 * (l.width() - 1));
1876 }
1877
1878 // Load first string and append to buffer.
1879 l.load();
1880 appendString(tree.lhs);
1881
1882 // Append all other strings to buffer.
1883 appendStrings(tree.rhs);
1884
1885 // Convert buffer to string.
1886 bufferToString(tree.pos());
1887 } else {
1888 // Generate code for first expression
1889 l = genExpr(tree.lhs, tree.lhs.type);
1890
1891 // If we have an increment of -32768 to +32767 of a local
1892 // int variable we can use an incr instruction instead of
1893 // proceeding further.
1894 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
1895 l instanceof LocalItem &&
1896 tree.lhs.type.getTag().isSubRangeOf(INT) &&
1897 tree.rhs.type.getTag().isSubRangeOf(INT) &&
1898 tree.rhs.type.constValue() != null) {
1899 int ival = ((Number) tree.rhs.type.constValue()).intValue();
1900 if (tree.hasTag(MINUS_ASG)) ival = -ival;
1901 ((LocalItem)l).incr(ival);
1902 result = l;
1903 return;
1904 }
1905 // Otherwise, duplicate expression, load one copy
1906 // and complete binary operation.
1907 l.duplicate();
1908 l.coerce(operator.type.getParameterTypes().head).load();
1909 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
1910 }
1911 result = items.makeAssignItem(l);
1912 }
1913
1914 public void visitUnary(JCUnary tree) {
1915 OperatorSymbol operator = (OperatorSymbol)tree.operator;
1916 if (tree.hasTag(NOT)) {
1917 CondItem od = genCond(tree.arg, false);
1918 result = od.negate();
1919 } else {
1920 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
1921 switch (tree.getTag()) {
1922 case POS:
1923 result = od.load();
1924 break;
1925 case NEG:
1926 result = od.load();
1927 code.emitop0(operator.opcode);
1928 break;
1929 case COMPL:
1930 result = od.load();
1931 emitMinusOne(od.typecode);
1932 code.emitop0(operator.opcode);
1933 break;
1934 case PREINC: case PREDEC:
1935 od.duplicate();
1936 if (od instanceof LocalItem &&
1937 (operator.opcode == iadd || operator.opcode == isub)) {
1938 ((LocalItem)od).incr(tree.hasTag(PREINC) ? 1 : -1);
1939 result = od;
1940 } else {
1941 od.load();
1942 code.emitop0(one(od.typecode));
1943 code.emitop0(operator.opcode);
1944 // Perform narrowing primitive conversion if byte,
1945 // char, or short. Fix for 4304655.
1946 if (od.typecode != INTcode &&
1947 Code.truncate(od.typecode) == INTcode)
1948 code.emitop0(int2byte + od.typecode - BYTEcode);
1949 result = items.makeAssignItem(od);
1950 }
1951 break;
1952 case POSTINC: case POSTDEC:
1953 od.duplicate();
1954 if (od instanceof LocalItem &&
1955 (operator.opcode == iadd || operator.opcode == isub)) {
1956 Item res = od.load();
1957 ((LocalItem)od).incr(tree.hasTag(POSTINC) ? 1 : -1);
1958 result = res;
1959 } else {
1960 Item res = od.load();
1961 od.stash(od.typecode);
1962 code.emitop0(one(od.typecode));
1963 code.emitop0(operator.opcode);
1964 // Perform narrowing primitive conversion if byte,
1965 // char, or short. Fix for 4304655.
1966 if (od.typecode != INTcode &&
1967 Code.truncate(od.typecode) == INTcode)
1968 code.emitop0(int2byte + od.typecode - BYTEcode);
1969 od.store();
1970 result = res;
1971 }
1972 break;
1973 case NULLCHK:
1974 result = od.load();
1975 code.emitop0(dup);
1976 genNullCheck(tree.pos());
1977 break;
1978 default:
1979 Assert.error();
1980 }
1981 }
1982 }
1983
1984 /** Generate a null check from the object value at stack top. */
1985 private void genNullCheck(DiagnosticPosition pos) {
1986 callMethod(pos, syms.objectType, names.getClass,
1987 List.<Type>nil(), false);
1988 code.emitop0(pop);
1989 }
1990
1991 public void visitBinary(JCBinary tree) {
1992 OperatorSymbol operator = (OperatorSymbol)tree.operator;
1993 if (operator.opcode == string_add) {
1994 // Create a string buffer.
1995 makeStringBuffer(tree.pos());
1996 // Append all strings to buffer.
1997 appendStrings(tree);
1998 // Convert buffer to string.
1999 bufferToString(tree.pos());
2000 result = items.makeStackItem(syms.stringType);
2001 } else if (tree.hasTag(AND)) {
2002 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2003 if (!lcond.isFalse()) {
2004 Chain falseJumps = lcond.jumpFalse();
2005 code.resolve(lcond.trueJumps);
2006 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2007 result = items.
2008 makeCondItem(rcond.opcode,
2009 rcond.trueJumps,
2010 Code.mergeChains(falseJumps,
2011 rcond.falseJumps));
2012 } else {
2013 result = lcond;
2014 }
2015 } else if (tree.hasTag(OR)) {
2016 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2017 if (!lcond.isTrue()) {
2018 Chain trueJumps = lcond.jumpTrue();
2019 code.resolve(lcond.falseJumps);
2020 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2021 result = items.
2022 makeCondItem(rcond.opcode,
2023 Code.mergeChains(trueJumps, rcond.trueJumps),
2024 rcond.falseJumps);
2025 } else {
2026 result = lcond;
2027 }
2028 } else {
2029 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
2030 od.load();
2031 result = completeBinop(tree.lhs, tree.rhs, operator);
2032 }
2033 }
2034 //where
2035 /** Make a new string buffer.
2036 */
2037 void makeStringBuffer(DiagnosticPosition pos) {
2038 code.emitop2(new_, makeRef(pos, stringBufferType));
2039 code.emitop0(dup);
2040 callMethod(
2041 pos, stringBufferType, names.init, List.<Type>nil(), false);
2042 }
2043
2044 /** Append value (on tos) to string buffer (on tos - 1).
2045 */
2046 void appendString(JCTree tree) {
2047 Type t = tree.type.baseType();
2048 if (!t.isPrimitive() && t.tsym != syms.stringType.tsym) {
2049 t = syms.objectType;
2050 }
2051 items.makeMemberItem(getStringBufferAppend(tree, t), false).invoke();
2052 }
2053 Symbol getStringBufferAppend(JCTree tree, Type t) {
2054 Assert.checkNull(t.constValue());
2055 Symbol method = stringBufferAppend.get(t);
2056 if (method == null) {
2057 method = rs.resolveInternalMethod(tree.pos(),
2058 attrEnv,
2059 stringBufferType,
2060 names.append,
2061 List.of(t),
2062 null);
2063 stringBufferAppend.put(t, method);
2064 }
2065 return method;
2066 }
2067
2068 /** Add all strings in tree to string buffer.
2069 */
2070 void appendStrings(JCTree tree) {
2071 tree = TreeInfo.skipParens(tree);
2072 if (tree.hasTag(PLUS) && tree.type.constValue() == null) {
2073 JCBinary op = (JCBinary) tree;
2074 if (op.operator.kind == MTH &&
2075 ((OperatorSymbol) op.operator).opcode == string_add) {
2076 appendStrings(op.lhs);
2077 appendStrings(op.rhs);
2078 return;
2079 }
2080 }
2081 genExpr(tree, tree.type).load();
2082 appendString(tree);
2083 }
2084
2085 /** Convert string buffer on tos to string.
2086 */
2087 void bufferToString(DiagnosticPosition pos) {
2088 callMethod(
2089 pos,
2090 stringBufferType,
2091 names.toString,
2092 List.<Type>nil(),
2093 false);
2094 }
2095
2096 /** Complete generating code for operation, with left operand
2097 * already on stack.
2098 * @param lhs The tree representing the left operand.
2099 * @param rhs The tree representing the right operand.
2100 * @param operator The operator symbol.
2101 */
2102 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2103 MethodType optype = (MethodType)operator.type;
2104 int opcode = operator.opcode;
2105 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2106 rhs.type.constValue() instanceof Number &&
2107 ((Number) rhs.type.constValue()).intValue() == 0) {
2108 opcode = opcode + (ifeq - if_icmpeq);
2109 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2110 TreeInfo.isNull(rhs)) {
2111 opcode = opcode + (if_acmp_null - if_acmpeq);
2112 } else {
2113 // The expected type of the right operand is
2114 // the second parameter type of the operator, except for
2115 // shifts with long shiftcount, where we convert the opcode
2116 // to a short shift and the expected type to int.
2117 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2118 if (opcode >= ishll && opcode <= lushrl) {
2119 opcode = opcode + (ishl - ishll);
2120 rtype = syms.intType;
2121 }
2122 // Generate code for right operand and load.
2123 genExpr(rhs, rtype).load();
2124 // If there are two consecutive opcode instructions,
2125 // emit the first now.
2126 if (opcode >= (1 << preShift)) {
2127 code.emitop0(opcode >> preShift);
2128 opcode = opcode & 0xFF;
2129 }
2130 }
2131 if (opcode >= ifeq && opcode <= if_acmpne ||
2132 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2133 return items.makeCondItem(opcode);
2134 } else {
2135 code.emitop0(opcode);
2136 return items.makeStackItem(optype.restype);
2137 }
2138 }
2139
2140 public void visitTypeCast(JCTypeCast tree) {
2141 setTypeAnnotationPositions(tree.pos);
2142 result = genExpr(tree.expr, tree.clazz.type).load();
2143 // Additional code is only needed if we cast to a reference type
2144 // which is not statically a supertype of the expression's type.
2145 // For basic types, the coerce(...) in genExpr(...) will do
2146 // the conversion.
2147 if (!tree.clazz.type.isPrimitive() &&
2148 !types.isSameType(tree.expr.type, tree.clazz.type) &&
2149 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2150 code.emitop2(checkcast, makeRef(tree.pos(), tree.clazz.type));
2151 }
2152 }
2153
2154 public void visitWildcard(JCWildcard tree) {
2155 throw new AssertionError(this.getClass().getName());
2156 }
2157
2158 public void visitTypeTest(JCInstanceOf tree) {
2159 setTypeAnnotationPositions(tree.pos);
2160 genExpr(tree.expr, tree.expr.type).load();
2161 code.emitop2(instanceof_, makeRef(tree.pos(), tree.clazz.type));
2162 result = items.makeStackItem(syms.booleanType);
2163 }
2164
2165 public void visitIndexed(JCArrayAccess tree) {
2166 genExpr(tree.indexed, tree.indexed.type).load();
2167 genExpr(tree.index, syms.intType).load();
2168 result = items.makeIndexedItem(tree.type);
2169 }
2170
2171 public void visitIdent(JCIdent tree) {
2172 Symbol sym = tree.sym;
2173 if (tree.name == names._this || tree.name == names._super) {
2174 Item res = tree.name == names._this
2175 ? items.makeThisItem()
2176 : items.makeSuperItem();
2177 if (sym.kind == MTH) {
2178 // Generate code to address the constructor.
2179 res.load();
2180 res = items.makeMemberItem(sym, true);
2181 }
2182 result = res;
2183 } else if (sym.kind == VAR && sym.owner.kind == MTH) {
2184 result = items.makeLocalItem((VarSymbol)sym);
2185 } else if (isInvokeDynamic(sym)) {
2186 result = items.makeDynamicItem(sym);
2187 } else if ((sym.flags() & STATIC) != 0) {
2188 if (!isAccessSuper(env.enclMethod))
2189 sym = binaryQualifier(sym, env.enclClass.type);
2190 result = items.makeStaticItem(sym);
2191 } else {
2192 items.makeThisItem().load();
2193 sym = binaryQualifier(sym, env.enclClass.type);
2194 result = items.makeMemberItem(sym, (sym.flags() & PRIVATE) != 0);
2195 }
2196 }
2197
2198 public void visitSelect(JCFieldAccess tree) {
2199 Symbol sym = tree.sym;
2200
2201 if (tree.name == names._class) {
2202 code.emitLdc(makeRef(tree.pos(), tree.selected.type));
2203 result = items.makeStackItem(pt);
2204 return;
2205 }
2206
2207 Symbol ssym = TreeInfo.symbol(tree.selected);
2208
2209 // Are we selecting via super?
2210 boolean selectSuper =
2211 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2212
2213 // Are we accessing a member of the superclass in an access method
2214 // resulting from a qualified super?
2215 boolean accessSuper = isAccessSuper(env.enclMethod);
2216
2217 Item base = (selectSuper)
2218 ? items.makeSuperItem()
2219 : genExpr(tree.selected, tree.selected.type);
2220
2221 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2222 // We are seeing a variable that is constant but its selecting
2223 // expression is not.
2224 if ((sym.flags() & STATIC) != 0) {
2225 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2226 base = base.load();
2227 base.drop();
2228 } else {
2229 base.load();
2230 genNullCheck(tree.selected.pos());
2231 }
2232 result = items.
2233 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2234 } else {
2235 if (isInvokeDynamic(sym)) {
2236 result = items.makeDynamicItem(sym);
2237 return;
2238 } else {
2239 sym = binaryQualifier(sym, tree.selected.type);
2240 }
2241 if ((sym.flags() & STATIC) != 0) {
2242 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2243 base = base.load();
2244 base.drop();
2245 result = items.makeStaticItem(sym);
2246 } else {
2247 base.load();
2248 if (sym == syms.lengthVar) {
2249 code.emitop0(arraylength);
2250 result = items.makeStackItem(syms.intType);
2251 } else {
2252 result = items.
2253 makeMemberItem(sym,
2254 (sym.flags() & PRIVATE) != 0 ||
2255 selectSuper || accessSuper);
2256 }
2257 }
2258 }
2259 }
2260
2261 public boolean isInvokeDynamic(Symbol sym) {
2262 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
2263 }
2264
2265 public void visitLiteral(JCLiteral tree) {
2266 if (tree.type.hasTag(BOT)) {
2267 code.emitop0(aconst_null);
2268 if (types.dimensions(pt) > 1) {
2269 code.emitop2(checkcast, makeRef(tree.pos(), pt));
2270 result = items.makeStackItem(pt);
2271 } else {
2272 result = items.makeStackItem(tree.type);
2273 }
2274 }
2275 else
2276 result = items.makeImmediateItem(tree.type, tree.value);
2277 }
2278
2279 public void visitLetExpr(LetExpr tree) {
2280 int limit = code.nextreg;
2281 genStats(tree.defs, env);
2282 result = genExpr(tree.expr, tree.expr.type).load();
2283 code.endScopes(limit);
2284 }
2285
2286 private void generateReferencesToPrunedTree(ClassSymbol classSymbol, Pool pool) {
2287 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
2288 if (prunedInfo != null) {
2289 for (JCTree prunedTree: prunedInfo) {
2290 prunedTree.accept(classReferenceVisitor);
2291 }
2292 }
2293 }
2294
2295 /* ************************************************************************
2296 * main method
2297 *************************************************************************/
2298
2299 /** Generate code for a class definition.
2300 * @param env The attribution environment that belongs to the
2301 * outermost class containing this class definition.
2302 * We need this for resolving some additional symbols.
2303 * @param cdef The tree representing the class definition.
2304 * @return True if code is generated with no errors.
2305 */
2306 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2307 try {
2308 attrEnv = env;
2309 ClassSymbol c = cdef.sym;
2310 this.toplevel = env.toplevel;
2311 this.endPosTable = toplevel.endPositions;
2312 cdef.defs = normalizeDefs(cdef.defs, c);
2313 c.pool = pool;
2314 pool.reset();
2315 generateReferencesToPrunedTree(c, pool);
2316 Env<GenContext> localEnv = new Env<>(cdef, new GenContext());
2317 localEnv.toplevel = env.toplevel;
2318 localEnv.enclClass = cdef;
2319
2320 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2321 genDef(l.head, localEnv);
2322 }
2323 if (pool.numEntries() > Pool.MAX_ENTRIES) {
2324 log.error(cdef.pos(), "limit.pool");
2325 nerrs++;
2326 }
2327 if (nerrs != 0) {
2328 // if errors, discard code
2329 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2330 if (l.head.hasTag(METHODDEF))
2331 ((JCMethodDecl) l.head).sym.code = null;
2332 }
2333 }
2334 cdef.defs = List.nil(); // discard trees
2335 return nerrs == 0;
2336 } finally {
2337 // note: this method does NOT support recursion.
2338 attrEnv = null;
2339 this.env = null;
2340 toplevel = null;
2341 endPosTable = null;
2342 nerrs = 0;
2343 }
2344 }
2345
2346 /* ************************************************************************
2347 * Auxiliary classes
2348 *************************************************************************/
2349
2350 /** An abstract class for finalizer generation.
2351 */
2352 abstract class GenFinalizer {
2353 /** Generate code to clean up when unwinding. */
2354 abstract void gen();
2355
2356 /** Generate code to clean up at last. */
2357 abstract void genLast();
2358
2359 /** Does this finalizer have some nontrivial cleanup to perform? */
2360 boolean hasFinalizer() { return true; }
2361 }
2362
2363 /** code generation contexts,
2364 * to be used as type parameter for environments.
2365 */
2366 static class GenContext {
2367
2368 /** A chain for all unresolved jumps that exit the current environment.
2369 */
2370 Chain exit = null;
2371
2372 /** A chain for all unresolved jumps that continue in the
2373 * current environment.
2374 */
2375 Chain cont = null;
2376
2377 /** A closure that generates the finalizer of the current environment.
2378 * Only set for Synchronized and Try contexts.
2379 */
2380 GenFinalizer finalize = null;
2381
2382 /** Is this a switch statement? If so, allocate registers
2383 * even when the variable declaration is unreachable.
2384 */
2385 boolean isSwitch = false;
2386
2387 /** A list buffer containing all gaps in the finalizer range,
2388 * where a catch all exception should not apply.
2389 */
2390 ListBuffer<Integer> gaps = null;
2391
2392 /** Add given chain to exit chain.
2393 */
2394 void addExit(Chain c) {
2395 exit = Code.mergeChains(c, exit);
2396 }
2397
2398 /** Add given chain to cont chain.
2399 */
2400 void addCont(Chain c) {
2401 cont = Code.mergeChains(c, cont);
2402 }
2403 }
2404
2405 }