1 /*
2 * Copyright (c) 1999, 2017, 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 com.sun.source.tree.NewClassTree.CreationMode;
29 import com.sun.tools.javac.tree.TreeInfo.PosKind;
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.resources.CompilerProperties.Errors;
44 import com.sun.tools.javac.tree.EndPosTable;
45 import com.sun.tools.javac.tree.JCTree.*;
46
47 import static com.sun.tools.javac.code.Flags.*;
48 import static com.sun.tools.javac.code.Kinds.Kind.*;
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 private static final Object[] NO_STATIC_ARGS = new Object[0];
64 protected static final Context.Key<Gen> genKey = new Context.Key<>();
65
66 private final Log log;
67 private final Symtab syms;
68 private final Check chk;
69 private final Resolve rs;
70 private final TreeMaker make;
71 private final Names names;
72 private final Target target;
73 private final Name accessDollar;
74 private final Types types;
75 private final Lower lower;
76 private final Annotate annotate;
77 private final StringConcat concat;
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 /**
87 * Are we presently traversing a let expression ? Yes if depth != 0
88 */
89 private int letExprDepth;
90
91 public static Gen instance(Context context) {
92 Gen instance = context.get(genKey);
93 if (instance == null)
94 instance = new Gen(context);
95 return instance;
96 }
97
98 /** Constant pool, reset by genClass.
99 */
100 private final Pool pool;
101
102 protected Gen(Context context) {
103 context.put(genKey, this);
104
105 names = Names.instance(context);
106 log = Log.instance(context);
107 syms = Symtab.instance(context);
108 chk = Check.instance(context);
109 rs = Resolve.instance(context);
110 make = TreeMaker.instance(context);
111 target = Target.instance(context);
112 types = Types.instance(context);
113 concat = StringConcat.instance(context);
114
115 methodType = new MethodType(null, null, null, syms.methodClass);
116 accessDollar = names.
117 fromString("access" + target.syntheticNameChar());
118 lower = Lower.instance(context);
119
120 Options options = Options.instance(context);
121 lineDebugInfo =
122 options.isUnset(G_CUSTOM) ||
123 options.isSet(G_CUSTOM, "lines");
124 varDebugInfo =
125 options.isUnset(G_CUSTOM)
126 ? options.isSet(G)
127 : options.isSet(G_CUSTOM, "vars");
128 genCrt = options.isSet(XJCOV);
129 debugCode = options.isSet("debug.code");
130 allowBetterNullChecks = target.hasObjects();
131 pool = new Pool(types);
132
133 // ignore cldc because we cannot have both stackmap formats
134 this.stackMap = StackMapFormat.JSR202;
135 annotate = Annotate.instance(context);
136 }
137
138 /** Switches
139 */
140 private final boolean lineDebugInfo;
141 private final boolean varDebugInfo;
142 private final boolean genCrt;
143 private final boolean debugCode;
144 private final boolean allowBetterNullChecks;
145
146 /** Code buffer, set by genMethod.
147 */
148 private Code code;
149
150 /** Items structure, set by genMethod.
151 */
152 private Items items;
153
154 /** Environment for symbol lookup, set by genClass
155 */
156 private Env<AttrContext> attrEnv;
157
158 /** The top level tree.
159 */
160 private JCCompilationUnit toplevel;
161
162 /** The number of code-gen errors in this class.
163 */
164 private int nerrs = 0;
165
166 /** An object containing mappings of syntax trees to their
167 * ending source positions.
168 */
169 EndPosTable endPosTable;
170
171 /** Generate code to load an integer constant.
172 * @param n The integer to be loaded.
173 */
174 void loadIntConst(int n) {
175 items.makeImmediateItem(syms.intType, n).load();
176 }
177
178 /** The opcode that loads a zero constant of a given type code.
179 * @param tc The given type code (@see ByteCode).
180 */
181 public static int zero(int tc) {
182 switch(tc) {
183 case INTcode: case BYTEcode: case SHORTcode: case CHARcode:
184 return iconst_0;
185 case LONGcode:
186 return lconst_0;
187 case FLOATcode:
188 return fconst_0;
189 case DOUBLEcode:
190 return dconst_0;
191 default:
192 throw new AssertionError("zero");
193 }
194 }
195
196 /** The opcode that loads a one constant of a given type code.
197 * @param tc The given type code (@see ByteCode).
198 */
199 public static int one(int tc) {
200 return zero(tc) + 1;
201 }
202
203 /** Generate code to load -1 of the given type code (either int or long).
204 * @param tc The given type code (@see ByteCode).
205 */
206 void emitMinusOne(int tc) {
207 if (tc == LONGcode) {
208 items.makeImmediateItem(syms.longType, Long.valueOf(-1)).load();
209 } else {
210 code.emitop0(iconst_m1);
211 }
212 }
213
214 /** Construct a symbol to reflect the qualifying type that should
215 * appear in the byte code as per JLS 13.1.
216 *
217 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except
218 * for those cases where we need to work around VM bugs).
219 *
220 * For {@literal target <= 1.1}: If qualified variable or method is defined in a
221 * non-accessible class, clone it with the qualifier class as owner.
222 *
223 * @param sym The accessed symbol
224 * @param site The qualifier's type.
225 */
226 Symbol binaryQualifier(Symbol sym, Type site) {
227
228 if (site.hasTag(ARRAY)) {
229 if (sym == syms.lengthVar ||
230 sym.owner != syms.arrayClass)
231 return sym;
232 // array clone can be qualified by the array type in later targets
233 Symbol qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name,
234 site, syms.noSymbol);
235 return sym.clone(qualifier);
236 }
237
238 if (sym.owner == site.tsym ||
239 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) {
240 return sym;
241 }
242
243 // leave alone methods inherited from Object
244 // JLS 13.1.
245 if (sym.owner == syms.objectType.tsym)
246 return sym;
247
248 return sym.clone(site.tsym);
249 }
250
251 /** Insert a reference to given type in the constant pool,
252 * checking for an array with too many dimensions;
253 * return the reference's index.
254 * @param type The type for which a reference is inserted.
255 */
256 int makeRef(DiagnosticPosition pos, Type type) {
257 checkDimension(pos, type);
258 if (type.isAnnotated()) {
259 return pool.put((Object)type);
260 } else {
261 return pool.put(type.hasTag(CLASS) ? (Object)type.tsym : (Object)type);
262 }
263 }
264
265 /** Check if the given type is an array with too many dimensions.
266 */
267 private void checkDimension(DiagnosticPosition pos, Type t) {
268 switch (t.getTag()) {
269 case METHOD:
270 checkDimension(pos, t.getReturnType());
271 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail)
272 checkDimension(pos, args.head);
273 break;
274 case ARRAY:
275 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) {
276 log.error(pos, Errors.LimitDimensions);
277 nerrs++;
278 }
279 break;
280 default:
281 break;
282 }
283 }
284
285 /** Create a tempory variable.
286 * @param type The variable's type.
287 */
288 LocalItem makeTemp(Type type) {
289 VarSymbol v = new VarSymbol(Flags.SYNTHETIC,
290 names.empty,
291 type,
292 env.enclMethod.sym);
293 code.newLocal(v);
294 return items.makeLocalItem(v);
295 }
296
297 /** Generate code to call a non-private method or constructor.
298 * @param pos Position to be used for error reporting.
299 * @param site The type of which the method is a member.
300 * @param name The method's name.
301 * @param argtypes The method's argument types.
302 * @param isStatic A flag that indicates whether we call a
303 * static or instance method.
304 */
305 void callMethod(DiagnosticPosition pos,
306 Type site, Name name, List<Type> argtypes,
307 boolean isStatic) {
308 Symbol msym = rs.
309 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null);
310 if (isStatic) items.makeStaticItem(msym).invoke();
311 else items.makeMemberItem(msym, name == names.init).invoke();
312 }
313
314 /** Is the given method definition an access method
315 * resulting from a qualified super? This is signified by an odd
316 * access code.
317 */
318 private boolean isAccessSuper(JCMethodDecl enclMethod) {
319 return
320 (enclMethod.mods.flags & SYNTHETIC) != 0 &&
321 isOddAccessName(enclMethod.name);
322 }
323
324 /** Does given name start with "access$" and end in an odd digit?
325 */
326 private boolean isOddAccessName(Name name) {
327 return
328 name.startsWith(accessDollar) &&
329 (name.getByteAt(name.getByteLength() - 1) & 1) == 1;
330 }
331
332 /* ************************************************************************
333 * Non-local exits
334 *************************************************************************/
335
336 /** Generate code to invoke the finalizer associated with given
337 * environment.
338 * Any calls to finalizers are appended to the environments `cont' chain.
339 * Mark beginning of gap in catch all range for finalizer.
340 */
341 void genFinalizer(Env<GenContext> env) {
342 if (code.isAlive() && env.info.finalize != null)
343 env.info.finalize.gen();
344 }
345
346 /** Generate code to call all finalizers of structures aborted by
347 * a non-local
348 * exit. Return target environment of the non-local exit.
349 * @param target The tree representing the structure that's aborted
350 * @param env The environment current at the non-local exit.
351 */
352 Env<GenContext> unwind(JCTree target, Env<GenContext> env) {
353 Env<GenContext> env1 = env;
354 while (true) {
355 genFinalizer(env1);
356 if (env1.tree == target) break;
357 env1 = env1.next;
358 }
359 return env1;
360 }
361
362 /** Mark end of gap in catch-all range for finalizer.
363 * @param env the environment which might contain the finalizer
364 * (if it does, env.info.gaps != null).
365 */
366 void endFinalizerGap(Env<GenContext> env) {
367 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1)
368 env.info.gaps.append(code.curCP());
369 }
370
371 /** Mark end of all gaps in catch-all ranges for finalizers of environments
372 * lying between, and including to two environments.
373 * @param from the most deeply nested environment to mark
374 * @param to the least deeply nested environment to mark
375 */
376 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) {
377 Env<GenContext> last = null;
378 while (last != to) {
379 endFinalizerGap(from);
380 last = from;
381 from = from.next;
382 }
383 }
384
385 /** Do any of the structures aborted by a non-local exit have
386 * finalizers that require an empty stack?
387 * @param target The tree representing the structure that's aborted
388 * @param env The environment current at the non-local exit.
389 */
390 boolean hasFinally(JCTree target, Env<GenContext> env) {
391 while (env.tree != target) {
392 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer())
393 return true;
394 env = env.next;
395 }
396 return false;
397 }
398
399 /* ************************************************************************
400 * Normalizing class-members.
401 *************************************************************************/
402
403 /** Distribute member initializer code into constructors and {@code <clinit>}
404 * method.
405 * @param defs The list of class member declarations.
406 * @param c The enclosing class.
407 */
408 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) {
409 ListBuffer<JCStatement> initCode = new ListBuffer<>();
410 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>();
411 ListBuffer<JCStatement> clinitCode = new ListBuffer<>();
412 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>();
413 ListBuffer<JCTree> methodDefs = new ListBuffer<>();
414 // Sort definitions into three listbuffers:
415 // - initCode for instance initializers
416 // - clinitCode for class initializers
417 // - methodDefs for method definitions
418 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
419 JCTree def = l.head;
420 switch (def.getTag()) {
421 case BLOCK:
422 JCBlock block = (JCBlock)def;
423 if ((block.flags & STATIC) != 0)
424 clinitCode.append(block);
425 else if ((block.flags & SYNTHETIC) == 0)
426 initCode.append(block);
427 break;
428 case METHODDEF:
429 methodDefs.append(def);
430 break;
431 case VARDEF:
432 JCVariableDecl vdef = (JCVariableDecl) def;
433 VarSymbol sym = vdef.sym;
434 checkDimension(vdef.pos(), sym.type);
435 if (vdef.init != null) {
436 if ((sym.flags() & STATIC) == 0) {
437 // Always initialize instance variables.
438 JCStatement init = make.at(vdef.pos()).
439 Assignment(sym, vdef.init);
440 initCode.append(init);
441 endPosTable.replaceTree(vdef, init);
442 initTAs.addAll(getAndRemoveNonFieldTAs(sym));
443 } else if (sym.getConstValue() == null) {
444 // Initialize class (static) variables only if
445 // they are not compile-time constants.
446 JCStatement init = make.at(vdef.pos).
447 Assignment(sym, vdef.init);
448 clinitCode.append(init);
449 endPosTable.replaceTree(vdef, init);
450 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym));
451 } else {
452 checkStringConstant(vdef.init.pos(), sym.getConstValue());
453 /* if the init contains a reference to an external class, add it to the
454 * constant's pool
455 */
456 vdef.init.accept(classReferenceVisitor);
457 }
458 }
459 break;
460 default:
461 Assert.error();
462 }
463 }
464 // Insert any instance initializers into all constructors.
465 if (initCode.length() != 0) {
466 List<JCStatement> inits = initCode.toList();
467 initTAs.addAll(c.getInitTypeAttributes());
468 List<Attribute.TypeCompound> initTAlist = initTAs.toList();
469 for (JCTree t : methodDefs) {
470 normalizeMethod((JCMethodDecl)t, inits, initTAlist);
471 }
472 }
473 // If there are class initializers, create a <clinit> method
474 // that contains them as its body.
475 if (clinitCode.length() != 0) {
476 MethodSymbol clinit = new MethodSymbol(
477 STATIC | (c.flags() & STRICTFP),
478 names.clinit,
479 new MethodType(
480 List.nil(), syms.voidType,
481 List.nil(), syms.methodClass),
482 c);
483 c.members().enter(clinit);
484 List<JCStatement> clinitStats = clinitCode.toList();
485 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
486 block.endpos = TreeInfo.endPos(clinitStats.last());
487 methodDefs.append(make.MethodDef(clinit, block));
488
489 if (!clinitTAs.isEmpty())
490 clinit.appendUniqueTypeAttributes(clinitTAs.toList());
491 if (!c.getClassInitTypeAttributes().isEmpty())
492 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes());
493 }
494 // Return all method definitions.
495 return methodDefs.toList();
496 }
497
498 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) {
499 List<TypeCompound> tas = sym.getRawTypeAttributes();
500 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>();
501 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>();
502 for (TypeCompound ta : tas) {
503 Assert.check(ta.getPosition().type != TargetType.UNKNOWN);
504 if (ta.getPosition().type == TargetType.FIELD) {
505 fieldTAs.add(ta);
506 } else {
507 nonfieldTAs.add(ta);
508 }
509 }
510 sym.setTypeAttributes(fieldTAs.toList());
511 return nonfieldTAs.toList();
512 }
513
514 /** Check a constant value and report if it is a string that is
515 * too large.
516 */
517 private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
518 if (nerrs != 0 || // only complain about a long string once
519 constValue == null ||
520 !(constValue instanceof String) ||
521 ((String)constValue).length() < Pool.MAX_STRING_LENGTH)
522 return;
523 log.error(pos, Errors.LimitString);
524 nerrs++;
525 }
526
527 /** Insert instance initializer code into initial constructor.
528 * @param md The tree potentially representing a
529 * constructor's definition.
530 * @param initCode The list of instance initializer statements.
531 * @param initTAs Type annotations from the initializer expression.
532 */
533 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<TypeCompound> initTAs) {
534 if (md.name == names.init && TreeInfo.isInitialConstructor(md)) {
535 // We are seeing a constructor that does not call another
536 // constructor of the same class.
537 List<JCStatement> stats = md.body.stats;
538 ListBuffer<JCStatement> newstats = new ListBuffer<>();
539
540 if (stats.nonEmpty()) {
541 // Copy initializers of synthetic variables generated in
542 // the translation of inner classes.
543 while (TreeInfo.isSyntheticInit(stats.head)) {
544 newstats.append(stats.head);
545 stats = stats.tail;
546 }
547 // Copy superclass constructor call
548 newstats.append(stats.head);
549 stats = stats.tail;
550 // Copy remaining synthetic initializers.
551 while (stats.nonEmpty() &&
552 TreeInfo.isSyntheticInit(stats.head)) {
553 newstats.append(stats.head);
554 stats = stats.tail;
555 }
556 // Now insert the initializer code.
557 newstats.appendList(initCode);
558 // And copy all remaining statements.
559 while (stats.nonEmpty()) {
560 newstats.append(stats.head);
561 stats = stats.tail;
562 }
563 }
564 md.body.stats = newstats.toList();
565 if (md.body.endpos == Position.NOPOS)
566 md.body.endpos = TreeInfo.endPos(md.body.stats.last());
567
568 md.sym.appendUniqueTypeAttributes(initTAs);
569 }
570 }
571
572 /* ************************************************************************
573 * Traversal methods
574 *************************************************************************/
575
576 /** Visitor argument: The current environment.
577 */
578 Env<GenContext> env;
579
580 /** Visitor argument: The expected type (prototype).
581 */
582 Type pt;
583
584 /** Visitor result: The item representing the computed value.
585 */
586 Item result;
587
588 /** Visitor method: generate code for a definition, catching and reporting
589 * any completion failures.
590 * @param tree The definition to be visited.
591 * @param env The environment current at the definition.
592 */
593 public void genDef(JCTree tree, Env<GenContext> env) {
594 Env<GenContext> prevEnv = this.env;
595 try {
596 this.env = env;
597 tree.accept(this);
598 } catch (CompletionFailure ex) {
599 chk.completionError(tree.pos(), ex);
600 } finally {
601 this.env = prevEnv;
602 }
603 }
604
605 /** Derived visitor method: check whether CharacterRangeTable
606 * should be emitted, if so, put a new entry into CRTable
607 * and call method to generate bytecode.
608 * If not, just call method to generate bytecode.
609 * @see #genStat(JCTree, Env)
610 *
611 * @param tree The tree to be visited.
612 * @param env The environment to use.
613 * @param crtFlags The CharacterRangeTable flags
614 * indicating type of the entry.
615 */
616 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
617 if (!genCrt) {
618 genStat(tree, env);
619 return;
620 }
621 int startpc = code.curCP();
622 genStat(tree, env);
623 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK;
624 code.crt.put(tree, crtFlags, startpc, code.curCP());
625 }
626
627 /** Derived visitor method: generate code for a statement.
628 */
629 public void genStat(JCTree tree, Env<GenContext> env) {
630 if (code.isAlive()) {
631 code.statBegin(tree.pos);
632 genDef(tree, env);
633 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) {
634 // variables whose declarations are in a switch
635 // can be used even if the decl is unreachable.
636 code.newLocal(((JCVariableDecl) tree).sym);
637 }
638 }
639
640 /** Derived visitor method: check whether CharacterRangeTable
641 * should be emitted, if so, put a new entry into CRTable
642 * and call method to generate bytecode.
643 * If not, just call method to generate bytecode.
644 * @see #genStats(List, Env)
645 *
646 * @param trees The list of trees to be visited.
647 * @param env The environment to use.
648 * @param crtFlags The CharacterRangeTable flags
649 * indicating type of the entry.
650 */
651 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
652 if (!genCrt) {
653 genStats(trees, env);
654 return;
655 }
656 if (trees.length() == 1) { // mark one statement with the flags
657 genStat(trees.head, env, crtFlags | CRT_STATEMENT);
658 } else {
659 int startpc = code.curCP();
660 genStats(trees, env);
661 code.crt.put(trees, crtFlags, startpc, code.curCP());
662 }
663 }
664
665 /** Derived visitor method: generate code for a list of statements.
666 */
667 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) {
668 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
669 genStat(l.head, env, CRT_STATEMENT);
670 }
671
672 /** Derived visitor method: check whether CharacterRangeTable
673 * should be emitted, if so, put a new entry into CRTable
674 * and call method to generate bytecode.
675 * If not, just call method to generate bytecode.
676 * @see #genCond(JCTree,boolean)
677 *
678 * @param tree The tree to be visited.
679 * @param crtFlags The CharacterRangeTable flags
680 * indicating type of the entry.
681 */
682 public CondItem genCond(JCTree tree, int crtFlags) {
683 if (!genCrt) return genCond(tree, false);
684 int startpc = code.curCP();
685 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
686 code.crt.put(tree, crtFlags, startpc, code.curCP());
687 return item;
688 }
689
690 /** Derived visitor method: generate code for a boolean
691 * expression in a control-flow context.
692 * @param _tree The expression to be visited.
693 * @param markBranches The flag to indicate that the condition is
694 * a flow controller so produced conditions
695 * should contain a proper tree to generate
696 * CharacterRangeTable branches for them.
697 */
698 public CondItem genCond(JCTree _tree, boolean markBranches) {
699 JCTree inner_tree = TreeInfo.skipParens(_tree);
700 if (inner_tree.hasTag(CONDEXPR)) {
701 JCConditional tree = (JCConditional)inner_tree;
702 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
703 if (cond.isTrue()) {
704 code.resolve(cond.trueJumps);
705 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
706 if (markBranches) result.tree = tree.truepart;
707 return result;
708 }
709 if (cond.isFalse()) {
710 code.resolve(cond.falseJumps);
711 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
712 if (markBranches) result.tree = tree.falsepart;
713 return result;
714 }
715 Chain secondJumps = cond.jumpFalse();
716 code.resolve(cond.trueJumps);
717 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
718 if (markBranches) first.tree = tree.truepart;
719 Chain falseJumps = first.jumpFalse();
720 code.resolve(first.trueJumps);
721 Chain trueJumps = code.branch(goto_);
722 code.resolve(secondJumps);
723 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
724 CondItem result = items.makeCondItem(second.opcode,
725 Code.mergeChains(trueJumps, second.trueJumps),
726 Code.mergeChains(falseJumps, second.falseJumps));
727 if (markBranches) result.tree = tree.falsepart;
728 return result;
729 } else {
730 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
731 if (markBranches) result.tree = _tree;
732 return result;
733 }
734 }
735
736 public Code getCode() {
737 return code;
738 }
739
740 public Items getItems() {
741 return items;
742 }
743
744 public Env<AttrContext> getAttrEnv() {
745 return attrEnv;
746 }
747
748 /** Visitor class for expressions which might be constant expressions.
749 * This class is a subset of TreeScanner. Intended to visit trees pruned by
750 * Lower as long as constant expressions looking for references to any
751 * ClassSymbol. Any such reference will be added to the constant pool so
752 * automated tools can detect class dependencies better.
753 */
754 class ClassReferenceVisitor extends JCTree.Visitor {
755
756 @Override
757 public void visitTree(JCTree tree) {}
758
759 @Override
760 public void visitBinary(JCBinary tree) {
761 tree.lhs.accept(this);
762 tree.rhs.accept(this);
763 }
764
765 @Override
766 public void visitSelect(JCFieldAccess tree) {
767 if (tree.selected.type.hasTag(CLASS)) {
768 makeRef(tree.selected.pos(), tree.selected.type);
769 }
770 }
771
772 @Override
773 public void visitIdent(JCIdent tree) {
774 if (tree.sym.owner instanceof ClassSymbol) {
775 pool.put(tree.sym.owner);
776 }
777 }
778
779 @Override
780 public void visitConditional(JCConditional tree) {
781 tree.cond.accept(this);
782 tree.truepart.accept(this);
783 tree.falsepart.accept(this);
784 }
785
786 @Override
787 public void visitUnary(JCUnary tree) {
788 tree.arg.accept(this);
789 }
790
791 @Override
792 public void visitParens(JCParens tree) {
793 tree.expr.accept(this);
794 }
795
796 @Override
797 public void visitTypeCast(JCTypeCast tree) {
798 tree.expr.accept(this);
799 }
800 }
801
802 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor();
803
804 /** Visitor method: generate code for an expression, catching and reporting
805 * any completion failures.
806 * @param tree The expression to be visited.
807 * @param pt The expression's expected type (proto-type).
808 */
809 public Item genExpr(JCTree tree, Type pt) {
810 Type prevPt = this.pt;
811 try {
812 if (tree.type.constValue() != null) {
813 // Short circuit any expressions which are constants
814 tree.accept(classReferenceVisitor);
815 checkStringConstant(tree.pos(), tree.type.constValue());
816 result = items.makeImmediateItem(tree.type, tree.type.constValue());
817 } else {
818 this.pt = pt;
819 tree.accept(this);
820 }
821 return result.coerce(pt);
822 } catch (CompletionFailure ex) {
823 chk.completionError(tree.pos(), ex);
824 code.state.stacksize = 1;
825 return items.makeStackItem(pt);
826 } finally {
827 this.pt = prevPt;
828 }
829 }
830
831 /** Derived visitor method: generate code for a list of method arguments.
832 * @param trees The argument expressions to be visited.
833 * @param pts The expression's expected types (i.e. the formal parameter
834 * types of the invoked method).
835 */
836 public void genArgs(List<JCExpression> trees, List<Type> pts) {
837 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
838 genExpr(l.head, pts.head).load();
839 pts = pts.tail;
840 }
841 // require lists be of same length
842 Assert.check(pts.isEmpty());
843 }
844
845 /* ************************************************************************
846 * Visitor methods for statements and definitions
847 *************************************************************************/
848
849 /** Thrown when the byte code size exceeds limit.
850 */
851 public static class CodeSizeOverflow extends RuntimeException {
852 private static final long serialVersionUID = 0;
853 public CodeSizeOverflow() {}
854 }
855
856 public void visitMethodDef(JCMethodDecl tree) {
857 // Create a new local environment that points pack at method
858 // definition.
859 Env<GenContext> localEnv = env.dup(tree);
860 localEnv.enclMethod = tree;
861 // The expected type of every return statement in this method
862 // is the method's return type.
863 this.pt = tree.sym.erasure(types).getReturnType();
864
865 checkDimension(tree.pos(), tree.sym.erasure(types));
866 genMethod(tree, localEnv, false);
867 }
868 //where
869 /** Generate code for a method.
870 * @param tree The tree representing the method definition.
871 * @param env The environment current for the method body.
872 * @param fatcode A flag that indicates whether all jumps are
873 * within 32K. We first invoke this method under
874 * the assumption that fatcode == false, i.e. all
875 * jumps are within 32K. If this fails, fatcode
876 * is set to true and we try again.
877 */
878 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
879 MethodSymbol meth = tree.sym;
880 int extras = 0;
881 // Count up extra parameters
882 if (meth.isConstructor()) {
883 extras++;
884 if (meth.enclClass().isInner() &&
885 !meth.enclClass().isStatic()) {
886 extras++;
887 }
888 } else if ((tree.mods.flags & STATIC) == 0) {
889 extras++;
890 }
891 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
892 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
893 ClassFile.MAX_PARAMETERS) {
894 log.error(tree.pos(), Errors.LimitParameters);
895 nerrs++;
896 }
897
898 else if (tree.body != null) {
899 // Create a new code structure and initialize it.
900 int startpcCrt = initCode(tree, env, fatcode);
901
902 try {
903 genStat(tree.body, env);
904 } catch (CodeSizeOverflow e) {
905 // Failed due to code limit, try again with jsr/ret
906 startpcCrt = initCode(tree, env, fatcode);
907 genStat(tree.body, env);
908 }
909
910 if (code.state.stacksize != 0) {
911 log.error(tree.body.pos(), Errors.StackSimError(tree.sym));
912 throw new AssertionError();
913 }
914
915 // If last statement could complete normally, insert a
916 // return at the end.
917 if (code.isAlive()) {
918 code.statBegin(TreeInfo.endPos(tree.body));
919 if (env.enclMethod == null ||
920 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
921 code.emitop0(return_);
922 } else {
923 // sometime dead code seems alive (4415991);
924 // generate a small loop instead
925 int startpc = code.entryPoint();
926 CondItem c = items.makeCondItem(goto_);
927 code.resolve(c.jumpTrue(), startpc);
928 }
929 }
930 if (genCrt)
931 code.crt.put(tree.body,
932 CRT_BLOCK,
933 startpcCrt,
934 code.curCP());
935
936 code.endScopes(0);
937
938 // If we exceeded limits, panic
939 if (code.checkLimits(tree.pos(), log)) {
940 nerrs++;
941 return;
942 }
943
944 // If we generated short code but got a long jump, do it again
945 // with fatCode = true.
946 if (!fatcode && code.fatcode) genMethod(tree, env, true);
947
948 // Clean up
949 if(stackMap == StackMapFormat.JSR202) {
950 code.lastFrame = null;
951 code.frameBeforeLast = null;
952 }
953
954 // Compress exception table
955 code.compressCatchTable();
956
957 // Fill in type annotation positions for exception parameters
958 code.fillExceptionParameterPositions();
959 }
960 }
961
962 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
963 MethodSymbol meth = tree.sym;
964
965 // Create a new code structure.
966 meth.code = code = new Code(meth,
967 fatcode,
968 lineDebugInfo ? toplevel.lineMap : null,
969 varDebugInfo,
970 stackMap,
971 debugCode,
972 genCrt ? new CRTable(tree, env.toplevel.endPositions)
973 : null,
974 syms,
975 types,
976 pool);
977 items = new Items(pool, code, syms, types);
978 if (code.debugCode) {
979 System.err.println(meth + " for body " + tree);
980 }
981
982 // If method is not static, create a new local variable address
983 // for `this'.
984 if ((tree.mods.flags & STATIC) == 0) {
985 Type selfType = meth.owner.type;
986 if (meth.isConstructor() && selfType != syms.objectType)
987 selfType = UninitializedType.uninitializedThis(selfType);
988 code.setDefined(
989 code.newLocal(
990 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
991 }
992
993 // Mark all parameters as defined from the beginning of
994 // the method.
995 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
996 checkDimension(l.head.pos(), l.head.sym.type);
997 code.setDefined(code.newLocal(l.head.sym));
998 }
999
1000 // Get ready to generate code for method body.
1001 int startpcCrt = genCrt ? code.curCP() : 0;
1002 code.entryPoint();
1003
1004 // Suppress initial stackmap
1005 code.pendingStackMap = false;
1006
1007 return startpcCrt;
1008 }
1009
1010 private void synthesizeValueMethod(JCMethodDecl methodDecl) {
1011
1012 Name name; List<Type> argTypes; Type resType;
1013
1014 switch (methodDecl.name.toString()) {
1015 case "hashCode":
1016 name = names.hashCode;
1017 argTypes = List.of(syms.objectType);
1018 resType = methodDecl.restype.type;
1019 break;
1020 case "equals":
1021 name = names.equals;
1022 argTypes = List.of(syms.objectType, syms.objectType);
1023 resType = methodDecl.restype.type;
1024 break;
1025 case "toString":
1026 name = names.toString;
1027 argTypes = List.of(syms.objectType);
1028 resType = methodDecl.restype.type;
1029 break;
1030 case "longHashCode":
1031 name = names.fromString("longHashCode");
1032 argTypes = List.of(syms.objectType);
1033 resType = methodDecl.restype.type;
1034 break;
1035 default:
1036 throw new AssertionError("Unexpected synthetic method body");
1037 }
1038
1039 Type.MethodType indyType = new Type.MethodType(argTypes,
1040 resType,
1041 List.nil(),
1042 syms.methodClass);
1043
1044 List<Type> bsm_staticArgs = List.of(syms.methodHandleLookupType,
1045 syms.stringType,
1046 syms.methodTypeType);
1047
1048 Symbol bsm = rs.resolveInternalMethod(methodDecl.pos(),
1049 getAttrEnv(),
1050 syms.valueBootstrapMethods,
1051 names.fromString("makeBootstrapMethod"),
1052 bsm_staticArgs,
1053 null);
1054
1055 Symbol.DynamicMethodSymbol dynSym = new Symbol.DynamicMethodSymbol(name,
1056 syms.noSymbol,
1057 ClassFile.REF_invokeStatic,
1058 (Symbol.MethodSymbol)bsm,
1059 indyType,
1060 NO_STATIC_ARGS);
1061
1062
1063 switch (methodDecl.name.toString()) {
1064 case "hashCode":
1065 code.emitop0(aload_0);
1066 items.makeDynamicItem(dynSym).invoke();
1067 code.emitop0(ireturn);
1068 return;
1069 case "equals":
1070 code.emitop0(aload_0);
1071 code.emitop0(aload_1);
1072 items.makeDynamicItem(dynSym).invoke();
1073 code.emitop0(ireturn);
1074 return;
1075 case "toString":
1076 code.emitop0(aload_0);
1077 items.makeDynamicItem(dynSym).invoke();
1078 code.emitop0(areturn);
1079 return;
1080 case "longHashCode":
1081 code.emitop0(aload_0);
1082 items.makeDynamicItem(dynSym).invoke();
1083 code.emitop0(lreturn);
1084 return;
1085 }
1086 }
1087
1088 public void visitVarDef(JCVariableDecl tree) {
1089 VarSymbol v = tree.sym;
1090 code.newLocal(v);
1091 if (tree.init != null) {
1092 checkStringConstant(tree.init.pos(), v.getConstValue());
1093 if (v.getConstValue() == null || varDebugInfo) {
1094 Assert.check(letExprDepth != 0 || code.state.stacksize == 0);
1095 genExpr(tree.init, v.erasure(types)).load();
1096 items.makeLocalItem(v).store();
1097 Assert.check(letExprDepth != 0 || code.state.stacksize == 0);
1098 }
1099 }
1100 checkDimension(tree.pos(), v.type);
1101 }
1102
1103 public void visitSkip(JCSkip tree) {
1104 }
1105
1106 public void visitBlock(JCBlock tree) {
1107 if ((tree.flags & SYNTHETIC) != 0 && env.tree.hasTag(METHODDEF) && (((JCMethodDecl) env.tree).sym.owner.flags() & VALUE) != 0) {
1108 synthesizeValueMethod((JCMethodDecl) env.tree);
1109 return;
1110 }
1111 int limit = code.nextreg;
1112 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1113 genStats(tree.stats, localEnv);
1114 // End the scope of all block-local variables in variable info.
1115 if (!env.tree.hasTag(METHODDEF)) {
1116 code.statBegin(tree.endpos);
1117 code.endScopes(limit);
1118 code.pendingStatPos = Position.NOPOS;
1119 }
1120 }
1121
1122 public void visitDoLoop(JCDoWhileLoop tree) {
1123 genLoop(tree, tree.body, tree.cond, List.nil(), false);
1124 }
1125
1126 public void visitWhileLoop(JCWhileLoop tree) {
1127 genLoop(tree, tree.body, tree.cond, List.nil(), true);
1128 }
1129
1130 public void visitWithField(JCWithField tree) {
1131 switch(tree.field.getTag()) {
1132 case IDENT:
1133 Symbol sym = ((JCIdent) tree.field).sym;
1134 items.makeThisItem().load();
1135 genExpr(tree.value, tree.field.type).load();
1136 sym = binaryQualifier(sym, env.enclClass.type);
1137 code.emitop2(withfield, pool.put(sym));
1138 result = items.makeStackItem(tree.type);
1139 break;
1140 case SELECT:
1141 JCFieldAccess fieldAccess = (JCFieldAccess) tree.field;
1142 sym = TreeInfo.symbol(fieldAccess);
1143 genExpr(fieldAccess.selected, fieldAccess.selected.type).load();
1144 genExpr(tree.value, tree.field.type).load();
1145 sym = binaryQualifier(sym, fieldAccess.selected.type);
1146 code.emitop2(withfield, pool.put(sym));
1147 result = items.makeStackItem(tree.type);
1148 break;
1149 default:
1150 Assert.check(false);
1151 }
1152 }
1153
1154 public void visitForLoop(JCForLoop tree) {
1155 int limit = code.nextreg;
1156 genStats(tree.init, env);
1157 genLoop(tree, tree.body, tree.cond, tree.step, true);
1158 code.endScopes(limit);
1159 }
1160 //where
1161 /** Generate code for a loop.
1162 * @param loop The tree representing the loop.
1163 * @param body The loop's body.
1164 * @param cond The loop's controling condition.
1165 * @param step "Step" statements to be inserted at end of
1166 * each iteration.
1167 * @param testFirst True if the loop test belongs before the body.
1168 */
1169 private void genLoop(JCStatement loop,
1170 JCStatement body,
1171 JCExpression cond,
1172 List<JCExpressionStatement> step,
1173 boolean testFirst) {
1174 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1175 int startpc = code.entryPoint();
1176 if (testFirst) { //while or for loop
1177 CondItem c;
1178 if (cond != null) {
1179 code.statBegin(cond.pos);
1180 Assert.check(code.state.stacksize == 0);
1181 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1182 } else {
1183 c = items.makeCondItem(goto_);
1184 }
1185 Chain loopDone = c.jumpFalse();
1186 code.resolve(c.trueJumps);
1187 Assert.check(code.state.stacksize == 0);
1188 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1189 code.resolve(loopEnv.info.cont);
1190 genStats(step, loopEnv);
1191 code.resolve(code.branch(goto_), startpc);
1192 code.resolve(loopDone);
1193 } else {
1194 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1195 code.resolve(loopEnv.info.cont);
1196 genStats(step, loopEnv);
1197 if (code.isAlive()) {
1198 CondItem c;
1199 if (cond != null) {
1200 code.statBegin(cond.pos);
1201 Assert.check(code.state.stacksize == 0);
1202 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1203 } else {
1204 c = items.makeCondItem(goto_);
1205 }
1206 code.resolve(c.jumpTrue(), startpc);
1207 Assert.check(code.state.stacksize == 0);
1208 code.resolve(c.falseJumps);
1209 }
1210 }
1211 Chain exit = loopEnv.info.exit;
1212 if (exit != null) {
1213 code.resolve(exit);
1214 exit.state.defined.excludeFrom(code.nextreg);
1215 }
1216 }
1217
1218 public void visitForeachLoop(JCEnhancedForLoop tree) {
1219 throw new AssertionError(); // should have been removed by Lower.
1220 }
1221
1222 public void visitLabelled(JCLabeledStatement tree) {
1223 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1224 genStat(tree.body, localEnv, CRT_STATEMENT);
1225 Chain exit = localEnv.info.exit;
1226 if (exit != null) {
1227 code.resolve(exit);
1228 exit.state.defined.excludeFrom(code.nextreg);
1229 }
1230 }
1231
1232 public void visitSwitch(JCSwitch tree) {
1233 int limit = code.nextreg;
1234 Assert.check(!tree.selector.type.hasTag(CLASS));
1235 int startpcCrt = genCrt ? code.curCP() : 0;
1236 Assert.check(code.state.stacksize == 0);
1237 Item sel = genExpr(tree.selector, syms.intType);
1238 List<JCCase> cases = tree.cases;
1239 if (cases.isEmpty()) {
1240 // We are seeing: switch <sel> {}
1241 sel.load().drop();
1242 if (genCrt)
1243 code.crt.put(TreeInfo.skipParens(tree.selector),
1244 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1245 } else {
1246 // We are seeing a nonempty switch.
1247 sel.load();
1248 if (genCrt)
1249 code.crt.put(TreeInfo.skipParens(tree.selector),
1250 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1251 Env<GenContext> switchEnv = env.dup(tree, new GenContext());
1252 switchEnv.info.isSwitch = true;
1253
1254 // Compute number of labels and minimum and maximum label values.
1255 // For each case, store its label in an array.
1256 int lo = Integer.MAX_VALUE; // minimum label.
1257 int hi = Integer.MIN_VALUE; // maximum label.
1258 int nlabels = 0; // number of labels.
1259
1260 int[] labels = new int[cases.length()]; // the label array.
1261 int defaultIndex = -1; // the index of the default clause.
1262
1263 List<JCCase> l = cases;
1264 for (int i = 0; i < labels.length; i++) {
1265 if (l.head.pat != null) {
1266 int val = ((Number)l.head.pat.type.constValue()).intValue();
1267 labels[i] = val;
1268 if (val < lo) lo = val;
1269 if (hi < val) hi = val;
1270 nlabels++;
1271 } else {
1272 Assert.check(defaultIndex == -1);
1273 defaultIndex = i;
1274 }
1275 l = l.tail;
1276 }
1277
1278 // Determine whether to issue a tableswitch or a lookupswitch
1279 // instruction.
1280 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1281 long table_time_cost = 3; // comparisons
1282 long lookup_space_cost = 3 + 2 * (long) nlabels;
1283 long lookup_time_cost = nlabels;
1284 int opcode =
1285 nlabels > 0 &&
1286 table_space_cost + 3 * table_time_cost <=
1287 lookup_space_cost + 3 * lookup_time_cost
1288 ?
1289 tableswitch : lookupswitch;
1290
1291 int startpc = code.curCP(); // the position of the selector operation
1292 code.emitop0(opcode);
1293 code.align(4);
1294 int tableBase = code.curCP(); // the start of the jump table
1295 int[] offsets = null; // a table of offsets for a lookupswitch
1296 code.emit4(-1); // leave space for default offset
1297 if (opcode == tableswitch) {
1298 code.emit4(lo); // minimum label
1299 code.emit4(hi); // maximum label
1300 for (long i = lo; i <= hi; i++) { // leave space for jump table
1301 code.emit4(-1);
1302 }
1303 } else {
1304 code.emit4(nlabels); // number of labels
1305 for (int i = 0; i < nlabels; i++) {
1306 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1307 }
1308 offsets = new int[labels.length];
1309 }
1310 Code.State stateSwitch = code.state.dup();
1311 code.markDead();
1312
1313 // For each case do:
1314 l = cases;
1315 for (int i = 0; i < labels.length; i++) {
1316 JCCase c = l.head;
1317 l = l.tail;
1318
1319 int pc = code.entryPoint(stateSwitch);
1320 // Insert offset directly into code or else into the
1321 // offsets table.
1322 if (i != defaultIndex) {
1323 if (opcode == tableswitch) {
1324 code.put4(
1325 tableBase + 4 * (labels[i] - lo + 3),
1326 pc - startpc);
1327 } else {
1328 offsets[i] = pc - startpc;
1329 }
1330 } else {
1331 code.put4(tableBase, pc - startpc);
1332 }
1333
1334 // Generate code for the statements in this case.
1335 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1336 }
1337
1338 // Resolve all breaks.
1339 Chain exit = switchEnv.info.exit;
1340 if (exit != null) {
1341 code.resolve(exit);
1342 exit.state.defined.excludeFrom(limit);
1343 }
1344
1345 // If we have not set the default offset, we do so now.
1346 if (code.get4(tableBase) == -1) {
1347 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1348 }
1349
1350 if (opcode == tableswitch) {
1351 // Let any unfilled slots point to the default case.
1352 int defaultOffset = code.get4(tableBase);
1353 for (long i = lo; i <= hi; i++) {
1354 int t = (int)(tableBase + 4 * (i - lo + 3));
1355 if (code.get4(t) == -1)
1356 code.put4(t, defaultOffset);
1357 }
1358 } else {
1359 // Sort non-default offsets and copy into lookup table.
1360 if (defaultIndex >= 0)
1361 for (int i = defaultIndex; i < labels.length - 1; i++) {
1362 labels[i] = labels[i+1];
1363 offsets[i] = offsets[i+1];
1364 }
1365 if (nlabels > 0)
1366 qsort2(labels, offsets, 0, nlabels - 1);
1367 for (int i = 0; i < nlabels; i++) {
1368 int caseidx = tableBase + 8 * (i + 1);
1369 code.put4(caseidx, labels[i]);
1370 code.put4(caseidx + 4, offsets[i]);
1371 }
1372 }
1373 }
1374 code.endScopes(limit);
1375 }
1376 //where
1377 /** Sort (int) arrays of keys and values
1378 */
1379 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1380 int i = lo;
1381 int j = hi;
1382 int pivot = keys[(i+j)/2];
1383 do {
1384 while (keys[i] < pivot) i++;
1385 while (pivot < keys[j]) j--;
1386 if (i <= j) {
1387 int temp1 = keys[i];
1388 keys[i] = keys[j];
1389 keys[j] = temp1;
1390 int temp2 = values[i];
1391 values[i] = values[j];
1392 values[j] = temp2;
1393 i++;
1394 j--;
1395 }
1396 } while (i <= j);
1397 if (lo < j) qsort2(keys, values, lo, j);
1398 if (i < hi) qsort2(keys, values, i, hi);
1399 }
1400
1401 public void visitSynchronized(JCSynchronized tree) {
1402 int limit = code.nextreg;
1403 // Generate code to evaluate lock and save in temporary variable.
1404 final LocalItem lockVar = makeTemp(syms.objectType);
1405 Assert.check(code.state.stacksize == 0);
1406 genExpr(tree.lock, tree.lock.type).load().duplicate();
1407 lockVar.store();
1408
1409 // Generate code to enter monitor.
1410 code.emitop0(monitorenter);
1411 code.state.lock(lockVar.reg);
1412
1413 // Generate code for a try statement with given body, no catch clauses
1414 // in a new environment with the "exit-monitor" operation as finalizer.
1415 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1416 syncEnv.info.finalize = new GenFinalizer() {
1417 void gen() {
1418 genLast();
1419 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1420 syncEnv.info.gaps.append(code.curCP());
1421 }
1422 void genLast() {
1423 if (code.isAlive()) {
1424 lockVar.load();
1425 code.emitop0(monitorexit);
1426 code.state.unlock(lockVar.reg);
1427 }
1428 }
1429 };
1430 syncEnv.info.gaps = new ListBuffer<>();
1431 genTry(tree.body, List.nil(), syncEnv);
1432 code.endScopes(limit);
1433 }
1434
1435 public void visitTry(final JCTry tree) {
1436 // Generate code for a try statement with given body and catch clauses,
1437 // in a new environment which calls the finally block if there is one.
1438 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1439 final Env<GenContext> oldEnv = env;
1440 tryEnv.info.finalize = new GenFinalizer() {
1441 void gen() {
1442 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1443 tryEnv.info.gaps.append(code.curCP());
1444 genLast();
1445 }
1446 void genLast() {
1447 if (tree.finalizer != null)
1448 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1449 }
1450 boolean hasFinalizer() {
1451 return tree.finalizer != null;
1452 }
1453
1454 @Override
1455 void afterBody() {
1456 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1457 //for body-only finally, remove the GenFinalizer after try body
1458 //so that the finally is not generated to catch bodies:
1459 tryEnv.info.finalize = null;
1460 }
1461 }
1462
1463 };
1464 tryEnv.info.gaps = new ListBuffer<>();
1465 genTry(tree.body, tree.catchers, tryEnv);
1466 }
1467 //where
1468 /** Generate code for a try or synchronized statement
1469 * @param body The body of the try or synchronized statement.
1470 * @param catchers The lis of catch clauses.
1471 * @param env the environment current for the body.
1472 */
1473 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1474 int limit = code.nextreg;
1475 int startpc = code.curCP();
1476 Code.State stateTry = code.state.dup();
1477 genStat(body, env, CRT_BLOCK);
1478 int endpc = code.curCP();
1479 List<Integer> gaps = env.info.gaps.toList();
1480 code.statBegin(TreeInfo.endPos(body));
1481 genFinalizer(env);
1482 code.statBegin(TreeInfo.endPos(env.tree));
1483 Chain exitChain = code.branch(goto_);
1484 endFinalizerGap(env);
1485 env.info.finalize.afterBody();
1486 boolean hasFinalizer =
1487 env.info.finalize != null &&
1488 env.info.finalize.hasFinalizer();
1489 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1490 // start off with exception on stack
1491 code.entryPoint(stateTry, l.head.param.sym.type);
1492 genCatch(l.head, env, startpc, endpc, gaps);
1493 genFinalizer(env);
1494 if (hasFinalizer || l.tail.nonEmpty()) {
1495 code.statBegin(TreeInfo.endPos(env.tree));
1496 exitChain = Code.mergeChains(exitChain,
1497 code.branch(goto_));
1498 }
1499 endFinalizerGap(env);
1500 }
1501 if (hasFinalizer) {
1502 // Create a new register segement to avoid allocating
1503 // the same variables in finalizers and other statements.
1504 code.newRegSegment();
1505
1506 // Add a catch-all clause.
1507
1508 // start off with exception on stack
1509 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1510
1511 // Register all exception ranges for catch all clause.
1512 // The range of the catch all clause is from the beginning
1513 // of the try or synchronized block until the present
1514 // code pointer excluding all gaps in the current
1515 // environment's GenContext.
1516 int startseg = startpc;
1517 while (env.info.gaps.nonEmpty()) {
1518 int endseg = env.info.gaps.next().intValue();
1519 registerCatch(body.pos(), startseg, endseg,
1520 catchallpc, 0);
1521 startseg = env.info.gaps.next().intValue();
1522 }
1523 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1524 code.markStatBegin();
1525
1526 Item excVar = makeTemp(syms.throwableType);
1527 excVar.store();
1528 genFinalizer(env);
1529 code.resolvePending();
1530 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1531 code.markStatBegin();
1532
1533 excVar.load();
1534 registerCatch(body.pos(), startseg,
1535 env.info.gaps.next().intValue(),
1536 catchallpc, 0);
1537 code.emitop0(athrow);
1538 code.markDead();
1539
1540 // If there are jsr's to this finalizer, ...
1541 if (env.info.cont != null) {
1542 // Resolve all jsr's.
1543 code.resolve(env.info.cont);
1544
1545 // Mark statement line number
1546 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1547 code.markStatBegin();
1548
1549 // Save return address.
1550 LocalItem retVar = makeTemp(syms.throwableType);
1551 retVar.store();
1552
1553 // Generate finalizer code.
1554 env.info.finalize.genLast();
1555
1556 // Return.
1557 code.emitop1w(ret, retVar.reg);
1558 code.markDead();
1559 }
1560 }
1561 // Resolve all breaks.
1562 code.resolve(exitChain);
1563
1564 code.endScopes(limit);
1565 }
1566
1567 /** Generate code for a catch clause.
1568 * @param tree The catch clause.
1569 * @param env The environment current in the enclosing try.
1570 * @param startpc Start pc of try-block.
1571 * @param endpc End pc of try-block.
1572 */
1573 void genCatch(JCCatch tree,
1574 Env<GenContext> env,
1575 int startpc, int endpc,
1576 List<Integer> gaps) {
1577 if (startpc != endpc) {
1578 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs
1579 = catchTypesWithAnnotations(tree);
1580 while (gaps.nonEmpty()) {
1581 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1582 JCExpression subCatch = subCatch1.snd;
1583 int catchType = makeRef(tree.pos(), subCatch.type);
1584 int end = gaps.head.intValue();
1585 registerCatch(tree.pos(),
1586 startpc, end, code.curCP(),
1587 catchType);
1588 for (Attribute.TypeCompound tc : subCatch1.fst) {
1589 tc.position.setCatchInfo(catchType, startpc);
1590 }
1591 }
1592 gaps = gaps.tail;
1593 startpc = gaps.head.intValue();
1594 gaps = gaps.tail;
1595 }
1596 if (startpc < endpc) {
1597 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1598 JCExpression subCatch = subCatch1.snd;
1599 int catchType = makeRef(tree.pos(), subCatch.type);
1600 registerCatch(tree.pos(),
1601 startpc, endpc, code.curCP(),
1602 catchType);
1603 for (Attribute.TypeCompound tc : subCatch1.fst) {
1604 tc.position.setCatchInfo(catchType, startpc);
1605 }
1606 }
1607 }
1608 VarSymbol exparam = tree.param.sym;
1609 code.statBegin(tree.pos);
1610 code.markStatBegin();
1611 int limit = code.nextreg;
1612 code.newLocal(exparam);
1613 items.makeLocalItem(exparam).store();
1614 code.statBegin(TreeInfo.firstStatPos(tree.body));
1615 genStat(tree.body, env, CRT_BLOCK);
1616 code.endScopes(limit);
1617 code.statBegin(TreeInfo.endPos(tree.body));
1618 }
1619 }
1620 // where
1621 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) {
1622 return TreeInfo.isMultiCatch(tree) ?
1623 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) :
1624 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype));
1625 }
1626 // where
1627 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) {
1628 List<JCExpression> alts = tree.alternatives;
1629 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head));
1630 alts = alts.tail;
1631
1632 while(alts != null && alts.head != null) {
1633 JCExpression alt = alts.head;
1634 if (alt instanceof JCAnnotatedType) {
1635 JCAnnotatedType a = (JCAnnotatedType)alt;
1636 res = res.prepend(new Pair<>(annotate.fromAnnotations(a.annotations), alt));
1637 } else {
1638 res = res.prepend(new Pair<>(List.nil(), alt));
1639 }
1640 alts = alts.tail;
1641 }
1642 return res.reverse();
1643 }
1644
1645 /** Register a catch clause in the "Exceptions" code-attribute.
1646 */
1647 void registerCatch(DiagnosticPosition pos,
1648 int startpc, int endpc,
1649 int handler_pc, int catch_type) {
1650 char startpc1 = (char)startpc;
1651 char endpc1 = (char)endpc;
1652 char handler_pc1 = (char)handler_pc;
1653 if (startpc1 == startpc &&
1654 endpc1 == endpc &&
1655 handler_pc1 == handler_pc) {
1656 code.addCatch(startpc1, endpc1, handler_pc1,
1657 (char)catch_type);
1658 } else {
1659 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1660 nerrs++;
1661 }
1662 }
1663
1664 public void visitIf(JCIf tree) {
1665 int limit = code.nextreg;
1666 Chain thenExit = null;
1667 Assert.check(code.state.stacksize == 0);
1668 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1669 CRT_FLOW_CONTROLLER);
1670 Chain elseChain = c.jumpFalse();
1671 Assert.check(code.state.stacksize == 0);
1672 if (!c.isFalse()) {
1673 code.resolve(c.trueJumps);
1674 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1675 thenExit = code.branch(goto_);
1676 }
1677 if (elseChain != null) {
1678 code.resolve(elseChain);
1679 if (tree.elsepart != null) {
1680 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1681 }
1682 }
1683 code.resolve(thenExit);
1684 code.endScopes(limit);
1685 Assert.check(code.state.stacksize == 0);
1686 }
1687
1688 public void visitExec(JCExpressionStatement tree) {
1689 // Optimize x++ to ++x and x-- to --x.
1690 JCExpression e = tree.expr;
1691 switch (e.getTag()) {
1692 case POSTINC:
1693 ((JCUnary) e).setTag(PREINC);
1694 break;
1695 case POSTDEC:
1696 ((JCUnary) e).setTag(PREDEC);
1697 break;
1698 }
1699 Assert.check(code.state.stacksize == 0);
1700 genExpr(tree.expr, tree.expr.type).drop();
1701 Assert.check(code.state.stacksize == 0);
1702 }
1703
1704 public void visitBreak(JCBreak tree) {
1705 int tmpPos = code.pendingStatPos;
1706 Env<GenContext> targetEnv = unwind(tree.target, env);
1707 code.pendingStatPos = tmpPos;
1708 Assert.check(code.state.stacksize == 0);
1709 targetEnv.info.addExit(code.branch(goto_));
1710 endFinalizerGaps(env, targetEnv);
1711 }
1712
1713 public void visitContinue(JCContinue tree) {
1714 int tmpPos = code.pendingStatPos;
1715 Env<GenContext> targetEnv = unwind(tree.target, env);
1716 code.pendingStatPos = tmpPos;
1717 Assert.check(code.state.stacksize == 0);
1718 targetEnv.info.addCont(code.branch(goto_));
1719 endFinalizerGaps(env, targetEnv);
1720 }
1721
1722 public void visitReturn(JCReturn tree) {
1723 int limit = code.nextreg;
1724 final Env<GenContext> targetEnv;
1725
1726 /* Save and then restore the location of the return in case a finally
1727 * is expanded (with unwind()) in the middle of our bytecodes.
1728 */
1729 int tmpPos = code.pendingStatPos;
1730 if (tree.expr != null) {
1731 Assert.check(code.state.stacksize == 0);
1732 Item r = genExpr(tree.expr, pt).load();
1733 if (hasFinally(env.enclMethod, env)) {
1734 r = makeTemp(pt);
1735 r.store();
1736 }
1737 targetEnv = unwind(env.enclMethod, env);
1738 code.pendingStatPos = tmpPos;
1739 r.load();
1740 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
1741 } else {
1742 targetEnv = unwind(env.enclMethod, env);
1743 code.pendingStatPos = tmpPos;
1744 code.emitop0(return_);
1745 }
1746 endFinalizerGaps(env, targetEnv);
1747 code.endScopes(limit);
1748 }
1749
1750 public void visitThrow(JCThrow tree) {
1751 Assert.check(code.state.stacksize == 0);
1752 genExpr(tree.expr, tree.expr.type).load();
1753 code.emitop0(athrow);
1754 Assert.check(code.state.stacksize == 0);
1755 }
1756
1757 /* ************************************************************************
1758 * Visitor methods for expressions
1759 *************************************************************************/
1760
1761 public void visitApply(JCMethodInvocation tree) {
1762 setTypeAnnotationPositions(tree.pos);
1763 // Generate code for method.
1764 Item m = genExpr(tree.meth, methodType);
1765 // Generate code for all arguments, where the expected types are
1766 // the parameters of the method's external type (that is, any implicit
1767 // outer instance of a super(...) call appears as first parameter).
1768 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
1769 genArgs(tree.args,
1770 msym.externalType(types).getParameterTypes());
1771 if (!msym.isDynamic()) {
1772 code.statBegin(tree.pos);
1773 }
1774 result = m.invoke();
1775 }
1776
1777 public void visitConditional(JCConditional tree) {
1778 Chain thenExit = null;
1779 code.statBegin(tree.cond.pos);
1780 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
1781 Chain elseChain = c.jumpFalse();
1782 if (!c.isFalse()) {
1783 code.resolve(c.trueJumps);
1784 int startpc = genCrt ? code.curCP() : 0;
1785 code.statBegin(tree.truepart.pos);
1786 genExpr(tree.truepart, pt).load();
1787 code.state.forceStackTop(tree.type);
1788 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
1789 startpc, code.curCP());
1790 thenExit = code.branch(goto_);
1791 }
1792 if (elseChain != null) {
1793 code.resolve(elseChain);
1794 int startpc = genCrt ? code.curCP() : 0;
1795 code.statBegin(tree.falsepart.pos);
1796 genExpr(tree.falsepart, pt).load();
1797 code.state.forceStackTop(tree.type);
1798 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
1799 startpc, code.curCP());
1800 }
1801 code.resolve(thenExit);
1802 result = items.makeStackItem(pt);
1803 }
1804
1805 private void setTypeAnnotationPositions(int treePos) {
1806 MethodSymbol meth = code.meth;
1807 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR
1808 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT;
1809
1810 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
1811 if (ta.hasUnknownPosition())
1812 ta.tryFixPosition();
1813
1814 if (ta.position.matchesPos(treePos))
1815 ta.position.updatePosOffset(code.cp);
1816 }
1817
1818 if (!initOrClinit)
1819 return;
1820
1821 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
1822 if (ta.hasUnknownPosition())
1823 ta.tryFixPosition();
1824
1825 if (ta.position.matchesPos(treePos))
1826 ta.position.updatePosOffset(code.cp);
1827 }
1828
1829 ClassSymbol clazz = meth.enclClass();
1830 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
1831 if (!s.getKind().isField())
1832 continue;
1833
1834 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
1835 if (ta.hasUnknownPosition())
1836 ta.tryFixPosition();
1837
1838 if (ta.position.matchesPos(treePos))
1839 ta.position.updatePosOffset(code.cp);
1840 }
1841 }
1842 }
1843
1844 public void visitNewClass(JCNewClass tree) {
1845 // Enclosing instances or anonymous classes should have been eliminated
1846 // by now.
1847 Assert.check(tree.encl == null && tree.def == null);
1848 setTypeAnnotationPositions(tree.pos);
1849
1850 Type newType = tree.type;
1851
1852 if (types.isValue(newType)) {
1853 Assert.check(tree.creationMode == CreationMode.DEFAULT_VALUE);
1854 Assert.check(tree.constructorType.getParameterTypes().isEmpty());
1855 code.emitop2(defaultvalue, makeRef(tree.pos(), newType));
1856 } else {
1857 code.emitop2(new_, makeRef(tree.pos(), tree.type));
1858 code.emitop0(dup);
1859
1860 // Generate code for all arguments, where the expected types are
1861 // the parameters of the constructor's external type (that is,
1862 // any implicit outer instance appears as first parameter).
1863 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
1864
1865 items.makeMemberItem(tree.constructor, true).invoke();
1866 }
1867 result = items.makeStackItem(tree.type);
1868 }
1869
1870 public void visitNewArray(JCNewArray tree) {
1871 setTypeAnnotationPositions(tree.pos);
1872
1873 if (tree.elems != null) {
1874 Type elemtype = types.elemtype(tree.type);
1875 loadIntConst(tree.elems.length());
1876 Item arr = makeNewArray(tree.pos(), tree.type, 1);
1877 int i = 0;
1878 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
1879 arr.duplicate();
1880 loadIntConst(i);
1881 i++;
1882 genExpr(l.head, elemtype).load();
1883 items.makeIndexedItem(elemtype).store();
1884 }
1885 result = arr;
1886 } else {
1887 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1888 genExpr(l.head, syms.intType).load();
1889 }
1890 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
1891 }
1892 }
1893 //where
1894 /** Generate code to create an array with given element type and number
1895 * of dimensions.
1896 */
1897 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
1898 Type elemtype = types.elemtype(type);
1899 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
1900 log.error(pos, Errors.LimitDimensions);
1901 nerrs++;
1902 }
1903 int elemcode = Code.arraycode(elemtype);
1904 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
1905 code.emitAnewarray(makeRef(pos, elemtype), type);
1906 } else if (elemcode == 1) {
1907 code.emitMultianewarray(ndims, makeRef(pos, type), type);
1908 } else {
1909 code.emitNewarray(elemcode, type);
1910 }
1911 return items.makeStackItem(type);
1912 }
1913
1914 public void visitParens(JCParens tree) {
1915 result = genExpr(tree.expr, tree.expr.type);
1916 }
1917
1918 public void visitAssign(JCAssign tree) {
1919 Item l = genExpr(tree.lhs, tree.lhs.type);
1920 genExpr(tree.rhs, tree.lhs.type).load();
1921 if (tree.rhs.type.hasTag(BOT)) {
1922 /* This is just a case of widening reference conversion that per 5.1.5 simply calls
1923 for "regarding a reference as having some other type in a manner that can be proved
1924 correct at compile time."
1925 */
1926 code.state.forceStackTop(tree.lhs.type);
1927 }
1928 result = items.makeAssignItem(l);
1929 }
1930
1931 public void visitAssignop(JCAssignOp tree) {
1932 OperatorSymbol operator = tree.operator;
1933 Item l;
1934 if (operator.opcode == string_add) {
1935 l = concat.makeConcat(tree);
1936 } else {
1937 // Generate code for first expression
1938 l = genExpr(tree.lhs, tree.lhs.type);
1939
1940 // If we have an increment of -32768 to +32767 of a local
1941 // int variable we can use an incr instruction instead of
1942 // proceeding further.
1943 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
1944 l instanceof LocalItem &&
1945 tree.lhs.type.getTag().isSubRangeOf(INT) &&
1946 tree.rhs.type.getTag().isSubRangeOf(INT) &&
1947 tree.rhs.type.constValue() != null) {
1948 int ival = ((Number) tree.rhs.type.constValue()).intValue();
1949 if (tree.hasTag(MINUS_ASG)) ival = -ival;
1950 ((LocalItem)l).incr(ival);
1951 result = l;
1952 return;
1953 }
1954 // Otherwise, duplicate expression, load one copy
1955 // and complete binary operation.
1956 l.duplicate();
1957 l.coerce(operator.type.getParameterTypes().head).load();
1958 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
1959 }
1960 result = items.makeAssignItem(l);
1961 }
1962
1963 public void visitUnary(JCUnary tree) {
1964 OperatorSymbol operator = tree.operator;
1965 if (tree.hasTag(NOT)) {
1966 CondItem od = genCond(tree.arg, false);
1967 result = od.negate();
1968 } else {
1969 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
1970 switch (tree.getTag()) {
1971 case POS:
1972 result = od.load();
1973 break;
1974 case NEG:
1975 result = od.load();
1976 code.emitop0(operator.opcode);
1977 break;
1978 case COMPL:
1979 result = od.load();
1980 emitMinusOne(od.typecode);
1981 code.emitop0(operator.opcode);
1982 break;
1983 case PREINC: case PREDEC:
1984 od.duplicate();
1985 if (od instanceof LocalItem &&
1986 (operator.opcode == iadd || operator.opcode == isub)) {
1987 ((LocalItem)od).incr(tree.hasTag(PREINC) ? 1 : -1);
1988 result = od;
1989 } else {
1990 od.load();
1991 code.emitop0(one(od.typecode));
1992 code.emitop0(operator.opcode);
1993 // Perform narrowing primitive conversion if byte,
1994 // char, or short. Fix for 4304655.
1995 if (od.typecode != INTcode &&
1996 Code.truncate(od.typecode) == INTcode)
1997 code.emitop0(int2byte + od.typecode - BYTEcode);
1998 result = items.makeAssignItem(od);
1999 }
2000 break;
2001 case POSTINC: case POSTDEC:
2002 od.duplicate();
2003 if (od instanceof LocalItem &&
2004 (operator.opcode == iadd || operator.opcode == isub)) {
2005 Item res = od.load();
2006 ((LocalItem)od).incr(tree.hasTag(POSTINC) ? 1 : -1);
2007 result = res;
2008 } else {
2009 Item res = od.load();
2010 od.stash(od.typecode);
2011 code.emitop0(one(od.typecode));
2012 code.emitop0(operator.opcode);
2013 // Perform narrowing primitive conversion if byte,
2014 // char, or short. Fix for 4304655.
2015 if (od.typecode != INTcode &&
2016 Code.truncate(od.typecode) == INTcode)
2017 code.emitop0(int2byte + od.typecode - BYTEcode);
2018 od.store();
2019 result = res;
2020 }
2021 break;
2022 case NULLCHK:
2023 result = od.load();
2024 code.emitop0(dup);
2025 genNullCheck(tree);
2026 break;
2027 default:
2028 Assert.error();
2029 }
2030 }
2031 }
2032
2033 /** Generate a null check from the object value at stack top. */
2034 private void genNullCheck(JCTree tree) {
2035 code.statBegin(tree.pos);
2036 if (allowBetterNullChecks) {
2037 callMethod(tree.pos(), syms.objectsType, names.requireNonNull,
2038 List.of(syms.objectType), true);
2039 } else {
2040 callMethod(tree.pos(), syms.objectType, names.getClass,
2041 List.nil(), false);
2042 }
2043 code.emitop0(pop);
2044 }
2045
2046 public void visitBinary(JCBinary tree) {
2047 OperatorSymbol operator = tree.operator;
2048 if (operator.opcode == string_add) {
2049 result = concat.makeConcat(tree);
2050 } else if (tree.hasTag(AND)) {
2051 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2052 if (!lcond.isFalse()) {
2053 Chain falseJumps = lcond.jumpFalse();
2054 code.resolve(lcond.trueJumps);
2055 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2056 result = items.
2057 makeCondItem(rcond.opcode,
2058 rcond.trueJumps,
2059 Code.mergeChains(falseJumps,
2060 rcond.falseJumps));
2061 } else {
2062 result = lcond;
2063 }
2064 } else if (tree.hasTag(OR)) {
2065 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2066 if (!lcond.isTrue()) {
2067 Chain trueJumps = lcond.jumpTrue();
2068 code.resolve(lcond.falseJumps);
2069 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2070 result = items.
2071 makeCondItem(rcond.opcode,
2072 Code.mergeChains(trueJumps, rcond.trueJumps),
2073 rcond.falseJumps);
2074 } else {
2075 result = lcond;
2076 }
2077 } else {
2078 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
2079 od.load();
2080 result = completeBinop(tree.lhs, tree.rhs, operator);
2081 }
2082 }
2083
2084
2085 /** Complete generating code for operation, with left operand
2086 * already on stack.
2087 * @param lhs The tree representing the left operand.
2088 * @param rhs The tree representing the right operand.
2089 * @param operator The operator symbol.
2090 */
2091 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2092 MethodType optype = (MethodType)operator.type;
2093 int opcode = operator.opcode;
2094 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2095 rhs.type.constValue() instanceof Number &&
2096 ((Number) rhs.type.constValue()).intValue() == 0) {
2097 opcode = opcode + (ifeq - if_icmpeq);
2098 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2099 TreeInfo.isNull(rhs)) {
2100 opcode = opcode + (if_acmp_null - if_acmpeq);
2101 } else {
2102 // The expected type of the right operand is
2103 // the second parameter type of the operator, except for
2104 // shifts with long shiftcount, where we convert the opcode
2105 // to a short shift and the expected type to int.
2106 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2107 if (opcode >= ishll && opcode <= lushrl) {
2108 opcode = opcode + (ishl - ishll);
2109 rtype = syms.intType;
2110 }
2111 // Generate code for right operand and load.
2112 genExpr(rhs, rtype).load();
2113 // If there are two consecutive opcode instructions,
2114 // emit the first now.
2115 if (opcode >= (1 << preShift)) {
2116 code.emitop0(opcode >> preShift);
2117 opcode = opcode & 0xFF;
2118 }
2119 }
2120 if (opcode >= ifeq && opcode <= if_acmpne ||
2121 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2122 return items.makeCondItem(opcode);
2123 } else {
2124 code.emitop0(opcode);
2125 return items.makeStackItem(optype.restype);
2126 }
2127 }
2128
2129 public void visitTypeCast(JCTypeCast tree) {
2130 result = genExpr(tree.expr, tree.clazz.type).load();
2131 setTypeAnnotationPositions(tree.pos);
2132 // Additional code is only needed if we cast to a reference type
2133 // which is not statically a supertype of the expression's type.
2134 // For basic types, the coerce(...) in genExpr(...) will do
2135 // the conversion.
2136 if (!tree.clazz.type.isPrimitive() &&
2137 !types.isSameType(tree.expr.type, tree.clazz.type) &&
2138 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2139 code.emitop2(checkcast, makeRef(tree.pos(), tree.clazz.type));
2140 }
2141 }
2142
2143 public void visitWildcard(JCWildcard tree) {
2144 throw new AssertionError(this.getClass().getName());
2145 }
2146
2147 public void visitTypeTest(JCInstanceOf tree) {
2148 genExpr(tree.expr, tree.expr.type).load();
2149 setTypeAnnotationPositions(tree.pos);
2150 code.emitop2(instanceof_, makeRef(tree.pos(), tree.clazz.type));
2151 result = items.makeStackItem(syms.booleanType);
2152 }
2153
2154 public void visitIndexed(JCArrayAccess tree) {
2155 genExpr(tree.indexed, tree.indexed.type).load();
2156 genExpr(tree.index, syms.intType).load();
2157 result = items.makeIndexedItem(tree.type);
2158 }
2159
2160 public void visitIdent(JCIdent tree) {
2161 Symbol sym = tree.sym;
2162 if (tree.name == names._this || tree.name == names._super) {
2163 Item res = tree.name == names._this
2164 ? items.makeThisItem()
2165 : items.makeSuperItem();
2166 if (sym.kind == MTH) {
2167 // Generate code to address the constructor.
2168 res.load();
2169 res = items.makeMemberItem(sym, true);
2170 }
2171 result = res;
2172 } else if (sym.kind == VAR && sym.owner.kind == MTH) {
2173 result = items.makeLocalItem((VarSymbol)sym);
2174 } else if (isInvokeDynamic(sym)) {
2175 result = items.makeDynamicItem(sym);
2176 } else if ((sym.flags() & STATIC) != 0) {
2177 if (!isAccessSuper(env.enclMethod))
2178 sym = binaryQualifier(sym, env.enclClass.type);
2179 result = items.makeStaticItem(sym);
2180 } else {
2181 items.makeThisItem().load();
2182 sym = binaryQualifier(sym, env.enclClass.type);
2183 result = items.makeMemberItem(sym, (sym.flags() & PRIVATE) != 0);
2184 }
2185 }
2186
2187 public void visitSelect(JCFieldAccess tree) {
2188 Symbol sym = tree.sym;
2189
2190 if (tree.name == names._class) {
2191 code.emitLdc(makeRef(tree.pos(), tree.selected.type));
2192 result = items.makeStackItem(pt);
2193 return;
2194 }
2195
2196 Symbol ssym = TreeInfo.symbol(tree.selected);
2197
2198 // Are we selecting via super?
2199 boolean selectSuper =
2200 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2201
2202 // Are we accessing a member of the superclass in an access method
2203 // resulting from a qualified super?
2204 boolean accessSuper = isAccessSuper(env.enclMethod);
2205
2206 Item base = (selectSuper)
2207 ? items.makeSuperItem()
2208 : genExpr(tree.selected, tree.selected.type);
2209
2210 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2211 // We are seeing a variable that is constant but its selecting
2212 // expression is not.
2213 if ((sym.flags() & STATIC) != 0) {
2214 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2215 base = base.load();
2216 base.drop();
2217 } else {
2218 base.load();
2219 genNullCheck(tree.selected);
2220 }
2221 result = items.
2222 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2223 } else {
2224 if (isInvokeDynamic(sym)) {
2225 result = items.makeDynamicItem(sym);
2226 return;
2227 } else {
2228 sym = binaryQualifier(sym, tree.selected.type);
2229 }
2230 if ((sym.flags() & STATIC) != 0) {
2231 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2232 base = base.load();
2233 base.drop();
2234 result = items.makeStaticItem(sym);
2235 } else {
2236 base.load();
2237 if (sym == syms.lengthVar) {
2238 code.emitop0(arraylength);
2239 result = items.makeStackItem(syms.intType);
2240 } else {
2241 result = items.
2242 makeMemberItem(sym,
2243 (sym.flags() & PRIVATE) != 0 ||
2244 selectSuper || accessSuper);
2245 }
2246 }
2247 }
2248 }
2249
2250 public boolean isInvokeDynamic(Symbol sym) {
2251 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
2252 }
2253
2254 public void visitLiteral(JCLiteral tree) {
2255 if (tree.type.hasTag(BOT)) {
2256 code.emitop0(aconst_null);
2257 result = items.makeStackItem(tree.type);
2258 }
2259 else
2260 result = items.makeImmediateItem(tree.type, tree.value);
2261 }
2262
2263 public void visitLetExpr(LetExpr tree) {
2264 letExprDepth++;
2265 int limit = code.nextreg;
2266 genStats(tree.defs, env);
2267 result = genExpr(tree.expr, tree.expr.type).load();
2268 code.endScopes(limit);
2269 letExprDepth--;
2270 }
2271
2272 private void generateReferencesToPrunedTree(ClassSymbol classSymbol, Pool pool) {
2273 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
2274 if (prunedInfo != null) {
2275 for (JCTree prunedTree: prunedInfo) {
2276 prunedTree.accept(classReferenceVisitor);
2277 }
2278 }
2279 }
2280
2281 /* ************************************************************************
2282 * main method
2283 *************************************************************************/
2284
2285 /** Generate code for a class definition.
2286 * @param env The attribution environment that belongs to the
2287 * outermost class containing this class definition.
2288 * We need this for resolving some additional symbols.
2289 * @param cdef The tree representing the class definition.
2290 * @return True if code is generated with no errors.
2291 */
2292 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2293 try {
2294 attrEnv = env;
2295 ClassSymbol c = cdef.sym;
2296 this.toplevel = env.toplevel;
2297 this.endPosTable = toplevel.endPositions;
2298 c.pool = pool;
2299 pool.reset();
2300 /* method normalizeDefs() can add references to external classes into the constant pool
2301 */
2302 cdef.defs = normalizeDefs(cdef.defs, c);
2303 generateReferencesToPrunedTree(c, pool);
2304 Env<GenContext> localEnv = new Env<>(cdef, new GenContext());
2305 localEnv.toplevel = env.toplevel;
2306 localEnv.enclClass = cdef;
2307
2308 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2309 genDef(l.head, localEnv);
2310 }
2311 if (pool.numEntries() > Pool.MAX_ENTRIES) {
2312 log.error(cdef.pos(), Errors.LimitPool);
2313 nerrs++;
2314 }
2315 if (nerrs != 0) {
2316 // if errors, discard code
2317 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2318 if (l.head.hasTag(METHODDEF))
2319 ((JCMethodDecl) l.head).sym.code = null;
2320 }
2321 }
2322 cdef.defs = List.nil(); // discard trees
2323 return nerrs == 0;
2324 } finally {
2325 // note: this method does NOT support recursion.
2326 attrEnv = null;
2327 this.env = null;
2328 toplevel = null;
2329 endPosTable = null;
2330 nerrs = 0;
2331 }
2332 }
2333
2334 /* ************************************************************************
2335 * Auxiliary classes
2336 *************************************************************************/
2337
2338 /** An abstract class for finalizer generation.
2339 */
2340 abstract class GenFinalizer {
2341 /** Generate code to clean up when unwinding. */
2342 abstract void gen();
2343
2344 /** Generate code to clean up at last. */
2345 abstract void genLast();
2346
2347 /** Does this finalizer have some nontrivial cleanup to perform? */
2348 boolean hasFinalizer() { return true; }
2349
2350 /** Should be invoked after the try's body has been visited. */
2351 void afterBody() {}
2352 }
2353
2354 /** code generation contexts,
2355 * to be used as type parameter for environments.
2356 */
2357 static class GenContext {
2358
2359 /** A chain for all unresolved jumps that exit the current environment.
2360 */
2361 Chain exit = null;
2362
2363 /** A chain for all unresolved jumps that continue in the
2364 * current environment.
2365 */
2366 Chain cont = null;
2367
2368 /** A closure that generates the finalizer of the current environment.
2369 * Only set for Synchronized and Try contexts.
2370 */
2371 GenFinalizer finalize = null;
2372
2373 /** Is this a switch statement? If so, allocate registers
2374 * even when the variable declaration is unreachable.
2375 */
2376 boolean isSwitch = false;
2377
2378 /** A list buffer containing all gaps in the finalizer range,
2379 * where a catch all exception should not apply.
2380 */
2381 ListBuffer<Integer> gaps = null;
2382
2383 /** Add given chain to exit chain.
2384 */
2385 void addExit(Chain c) {
2386 exit = Code.mergeChains(c, exit);
2387 }
2388
2389 /** Add given chain to cont chain.
2390 */
2391 void addCont(Chain c) {
2392 cont = Code.mergeChains(c, cont);
2393 }
2394 }
2395
2396 }