1 /*
2 * Copyright (c) 1999, 2018, 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.tools.javac.code.Types.UniqueType;
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 private final TransValues transValues;
79
80 /** Format of stackmap tables to be generated. */
81 private final Code.StackMapFormat stackMap;
82
83 /** A type that serves as the expected type for all method expressions.
84 */
85 private final Type methodType;
86
87 public static Gen instance(Context context) {
88 Gen instance = context.get(genKey);
89 if (instance == null)
90 instance = new Gen(context);
91 return instance;
92 }
93
94 /** Constant pool, reset by genClass.
95 */
96 private final Pool pool;
97
98 protected Gen(Context context) {
99 context.put(genKey, this);
100
101 names = Names.instance(context);
102 log = Log.instance(context);
103 syms = Symtab.instance(context);
104 chk = Check.instance(context);
105 rs = Resolve.instance(context);
106 make = TreeMaker.instance(context);
107 target = Target.instance(context);
108 types = Types.instance(context);
109 concat = StringConcat.instance(context);
110
111 methodType = new MethodType(null, null, null, syms.methodClass);
112 accessDollar = names.
113 fromString("access" + target.syntheticNameChar());
114 lower = Lower.instance(context);
115 transValues = TransValues.instance(context);
116
117 Options options = Options.instance(context);
118 lineDebugInfo =
119 options.isUnset(G_CUSTOM) ||
120 options.isSet(G_CUSTOM, "lines");
121 varDebugInfo =
122 options.isUnset(G_CUSTOM)
123 ? options.isSet(G)
124 : options.isSet(G_CUSTOM, "vars");
125 genCrt = options.isSet(XJCOV);
126 debugCode = options.isSet("debug.code");
127 disableVirtualizedPrivateInvoke = options.isSet("disableVirtualizedPrivateInvoke");
128 pool = new Pool(types);
129 staticInitValueFactory = options.isSet("staticInitValueFactory");
130
131 // ignore cldc because we cannot have both stackmap formats
132 this.stackMap = StackMapFormat.JSR202;
133 annotate = Annotate.instance(context);
134 }
135
136 /** Switches
137 */
138 private final boolean lineDebugInfo;
139 private final boolean varDebugInfo;
140 private final boolean genCrt;
141 private final boolean debugCode;
142 private boolean disableVirtualizedPrivateInvoke;
143
144 private boolean staticInitValueFactory;
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 boolean inCondSwitchExpression;
172 Chain switchExpressionTrueChain;
173 Chain switchExpressionFalseChain;
174 List<LocalItem> stackBeforeSwitchExpression;
175
176 /** Generate code to load an integer constant.
177 * @param n The integer to be loaded.
178 */
179 void loadIntConst(int n) {
180 items.makeImmediateItem(syms.intType, n).load();
181 }
182
183 /** The opcode that loads a zero constant of a given type code.
184 * @param tc The given type code (@see ByteCode).
185 */
186 public static int zero(int tc) {
187 switch(tc) {
188 case INTcode: case BYTEcode: case SHORTcode: case CHARcode:
189 return iconst_0;
190 case LONGcode:
191 return lconst_0;
192 case FLOATcode:
193 return fconst_0;
194 case DOUBLEcode:
195 return dconst_0;
196 default:
197 throw new AssertionError("zero");
198 }
199 }
200
201 /** The opcode that loads a one constant of a given type code.
202 * @param tc The given type code (@see ByteCode).
203 */
204 public static int one(int tc) {
205 return zero(tc) + 1;
206 }
207
208 /** Generate code to load -1 of the given type code (either int or long).
209 * @param tc The given type code (@see ByteCode).
210 */
211 void emitMinusOne(int tc) {
212 if (tc == LONGcode) {
213 items.makeImmediateItem(syms.longType, Long.valueOf(-1)).load();
214 } else {
215 code.emitop0(iconst_m1);
216 }
217 }
218
219 /** Construct a symbol to reflect the qualifying type that should
220 * appear in the byte code as per JLS 13.1.
221 *
222 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except
223 * for those cases where we need to work around VM bugs).
224 *
225 * For {@literal target <= 1.1}: If qualified variable or method is defined in a
226 * non-accessible class, clone it with the qualifier class as owner.
227 *
228 * @param sym The accessed symbol
229 * @param site The qualifier's type.
230 */
231 Symbol binaryQualifier(Symbol sym, Type site) {
232
233 if (site.hasTag(ARRAY)) {
234 if (sym == syms.lengthVar ||
235 sym.owner != syms.arrayClass)
236 return sym;
237 // array clone can be qualified by the array type in later targets
238 Symbol qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name,
239 site, syms.noSymbol);
240 return sym.clone(qualifier);
241 }
242
243 if (sym.owner == site.tsym ||
244 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) {
245 return sym;
246 }
247
248 // leave alone methods inherited from Object
249 // JLS 13.1.
250 if (sym.owner == syms.objectType.tsym)
251 return sym;
252
253 return sym.clone(site.tsym);
254 }
255
256 /** Insert a reference to given type in the constant pool,
257 * checking for an array with too many dimensions;
258 * return the reference's index.
259 * @param type The type for which a reference is inserted.
260 */
261 int makeRef(DiagnosticPosition pos, Type type, boolean emitQtype) {
262 checkDimension(pos, type);
263 if (type.isAnnotated()) {
264 return pool.put(emitQtype ? new UniqueType(type, types, false) : type);
265 } else {
266 return pool.put(type.hasTag(CLASS) ? emitQtype ? new UniqueType(type, types, false) : type.tsym : (Object)type);
267 }
268 }
269
270 /** Insert a reference to given type in the constant pool,
271 * checking for an array with too many dimensions;
272 * return the reference's index.
273 * @param type The type for which a reference is inserted.
274 */
275 int makeRef(DiagnosticPosition pos, Type type) {
276 return makeRef(pos, type, false);
277 }
278
279 /** Check if the given type is an array with too many dimensions.
280 */
281 private void checkDimension(DiagnosticPosition pos, Type t) {
282 switch (t.getTag()) {
283 case METHOD:
284 checkDimension(pos, t.getReturnType());
285 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail)
286 checkDimension(pos, args.head);
287 break;
288 case ARRAY:
289 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) {
290 log.error(pos, Errors.LimitDimensions);
291 nerrs++;
292 }
293 break;
294 default:
295 break;
296 }
297 }
298
299 /** Create a tempory variable.
300 * @param type The variable's type.
301 */
302 LocalItem makeTemp(Type type) {
303 VarSymbol v = new VarSymbol(Flags.SYNTHETIC,
304 names.empty,
305 type,
306 env.enclMethod.sym);
307 code.newLocal(v);
308 return items.makeLocalItem(v);
309 }
310
311 /** Generate code to call a non-private method or constructor.
312 * @param pos Position to be used for error reporting.
313 * @param site The type of which the method is a member.
314 * @param name The method's name.
315 * @param argtypes The method's argument types.
316 * @param isStatic A flag that indicates whether we call a
317 * static or instance method.
318 */
319 void callMethod(DiagnosticPosition pos,
320 Type site, Name name, List<Type> argtypes,
321 boolean isStatic) {
322 Symbol msym = rs.
323 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null);
324 if (isStatic) items.makeStaticItem(msym).invoke();
325 else items.makeMemberItem(msym, name == names.init).invoke();
326 }
327
328 /** Is the given method definition an access method
329 * resulting from a qualified super? This is signified by an odd
330 * access code.
331 */
332 private boolean isAccessSuper(JCMethodDecl enclMethod) {
333 return
334 (enclMethod.mods.flags & SYNTHETIC) != 0 &&
335 isOddAccessName(enclMethod.name);
336 }
337
338 /** Does given name start with "access$" and end in an odd digit?
339 */
340 private boolean isOddAccessName(Name name) {
341 return
342 name.startsWith(accessDollar) &&
343 (name.getByteAt(name.getByteLength() - 1) & 1) == 1;
344 }
345
346 /* ************************************************************************
347 * Non-local exits
348 *************************************************************************/
349
350 /** Generate code to invoke the finalizer associated with given
351 * environment.
352 * Any calls to finalizers are appended to the environments `cont' chain.
353 * Mark beginning of gap in catch all range for finalizer.
354 */
355 void genFinalizer(Env<GenContext> env) {
356 if (code.isAlive() && env.info.finalize != null)
357 env.info.finalize.gen();
358 }
359
360 /** Generate code to call all finalizers of structures aborted by
361 * a non-local
362 * exit. Return target environment of the non-local exit.
363 * @param target The tree representing the structure that's aborted
364 * @param env The environment current at the non-local exit.
365 */
366 Env<GenContext> unwind(JCTree target, Env<GenContext> env) {
367 Env<GenContext> env1 = env;
368 while (true) {
369 genFinalizer(env1);
370 if (env1.tree == target) break;
371 env1 = env1.next;
372 }
373 return env1;
374 }
375
376 /** Mark end of gap in catch-all range for finalizer.
377 * @param env the environment which might contain the finalizer
378 * (if it does, env.info.gaps != null).
379 */
380 void endFinalizerGap(Env<GenContext> env) {
381 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1)
382 env.info.gaps.append(code.curCP());
383 }
384
385 /** Mark end of all gaps in catch-all ranges for finalizers of environments
386 * lying between, and including to two environments.
387 * @param from the most deeply nested environment to mark
388 * @param to the least deeply nested environment to mark
389 */
390 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) {
391 Env<GenContext> last = null;
392 while (last != to) {
393 endFinalizerGap(from);
394 last = from;
395 from = from.next;
396 }
397 }
398
399 /** Do any of the structures aborted by a non-local exit have
400 * finalizers that require an empty stack?
401 * @param target The tree representing the structure that's aborted
402 * @param env The environment current at the non-local exit.
403 */
404 boolean hasFinally(JCTree target, Env<GenContext> env) {
405 while (env.tree != target) {
406 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer())
407 return true;
408 env = env.next;
409 }
410 return false;
411 }
412
413 /* ************************************************************************
414 * Normalizing class-members.
415 *************************************************************************/
416
417 /** Distribute member initializer code into constructors and {@code <clinit>}
418 * method.
419 * @param defs The list of class member declarations.
420 * @param c The enclosing class.
421 */
422 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) {
423 ListBuffer<JCStatement> initCode = new ListBuffer<>();
424 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>();
425 ListBuffer<JCStatement> clinitCode = new ListBuffer<>();
426 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>();
427 ListBuffer<JCTree> methodDefs = new ListBuffer<>();
428 // Sort definitions into three listbuffers:
429 // - initCode for instance initializers
430 // - clinitCode for class initializers
431 // - methodDefs for method definitions
432 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
433 JCTree def = l.head;
434 switch (def.getTag()) {
435 case BLOCK:
436 JCBlock block = (JCBlock)def;
437 if ((block.flags & STATIC) != 0)
438 clinitCode.append(block);
439 else if ((block.flags & SYNTHETIC) == 0)
440 initCode.append(block);
441 break;
442 case METHODDEF:
443 methodDefs.append(def);
444 break;
445 case VARDEF:
446 JCVariableDecl vdef = (JCVariableDecl) def;
447 VarSymbol sym = vdef.sym;
448 checkDimension(vdef.pos(), sym.type);
449 if (vdef.init != null) {
450 if ((sym.flags() & STATIC) == 0) {
451 // Always initialize instance variables.
452 JCStatement init = make.at(vdef.pos()).
453 Assignment(sym, vdef.init);
454 initCode.append(init);
455 endPosTable.replaceTree(vdef, init);
456 initTAs.addAll(getAndRemoveNonFieldTAs(sym));
457 } else if (sym.getConstValue() == null) {
458 // Initialize class (static) variables only if
459 // they are not compile-time constants.
460 JCStatement init = make.at(vdef.pos).
461 Assignment(sym, vdef.init);
462 clinitCode.append(init);
463 endPosTable.replaceTree(vdef, init);
464 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym));
465 } else {
466 checkStringConstant(vdef.init.pos(), sym.getConstValue());
467 /* if the init contains a reference to an external class, add it to the
468 * constant's pool
469 */
470 vdef.init.accept(classReferenceVisitor);
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.nil(), syms.voidType,
495 List.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, Errors.LimitString);
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 if (inner_tree.hasTag(SWITCH_EXPRESSION)) {
744 boolean prevInCondSwitchExpression = inCondSwitchExpression;
745 Chain prevSwitchExpressionTrueChain = switchExpressionTrueChain;
746 Chain prevSwitchExpressionFalseChain = switchExpressionFalseChain;
747 try {
748 inCondSwitchExpression = true;
749 switchExpressionTrueChain = null;
750 switchExpressionFalseChain = null;
751 try {
752 doHandleSwitchExpression((JCSwitchExpression) inner_tree);
753 } catch (CompletionFailure ex) {
754 chk.completionError(_tree.pos(), ex);
755 code.state.stacksize = 1;
756 }
757 CondItem result = items.makeCondItem(goto_,
758 switchExpressionTrueChain,
759 switchExpressionFalseChain);
760 if (markBranches) result.tree = _tree;
761 return result;
762 } finally {
763 inCondSwitchExpression = prevInCondSwitchExpression;
764 switchExpressionTrueChain = prevSwitchExpressionTrueChain;
765 switchExpressionFalseChain = prevSwitchExpressionFalseChain;
766 }
767 } else if (inner_tree.hasTag(LETEXPR) && ((LetExpr) inner_tree).needsCond) {
768 LetExpr tree = (LetExpr) inner_tree;
769 int limit = code.nextreg;
770 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
771 try {
772 genStats(tree.defs, env);
773 } finally {
774 code.setLetExprStackPos(prevLetExprStart);
775 }
776 CondItem result = genCond(tree.expr, markBranches);
777 code.endScopes(limit);
778 return result;
779 } else {
780 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
781 if (markBranches) result.tree = _tree;
782 return result;
783 }
784 }
785
786 public Code getCode() {
787 return code;
788 }
789
790 public Items getItems() {
791 return items;
792 }
793
794 public Env<AttrContext> getAttrEnv() {
795 return attrEnv;
796 }
797
798 /** Visitor class for expressions which might be constant expressions.
799 * This class is a subset of TreeScanner. Intended to visit trees pruned by
800 * Lower as long as constant expressions looking for references to any
801 * ClassSymbol. Any such reference will be added to the constant pool so
802 * automated tools can detect class dependencies better.
803 */
804 class ClassReferenceVisitor extends JCTree.Visitor {
805
806 @Override
807 public void visitTree(JCTree tree) {}
808
809 @Override
810 public void visitBinary(JCBinary tree) {
811 tree.lhs.accept(this);
812 tree.rhs.accept(this);
813 }
814
815 @Override
816 public void visitSelect(JCFieldAccess tree) {
817 if (tree.selected.type.hasTag(CLASS)) {
818 makeRef(tree.selected.pos(), tree.selected.type);
819 }
820 }
821
822 @Override
823 public void visitIdent(JCIdent tree) {
824 if (tree.sym.owner instanceof ClassSymbol) {
825 pool.put(tree.sym.owner);
826 }
827 }
828
829 @Override
830 public void visitConditional(JCConditional tree) {
831 tree.cond.accept(this);
832 tree.truepart.accept(this);
833 tree.falsepart.accept(this);
834 }
835
836 @Override
837 public void visitUnary(JCUnary tree) {
838 tree.arg.accept(this);
839 }
840
841 @Override
842 public void visitParens(JCParens tree) {
843 tree.expr.accept(this);
844 }
845
846 @Override
847 public void visitTypeCast(JCTypeCast tree) {
848 tree.expr.accept(this);
849 }
850 }
851
852 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor();
853
854 /** Visitor method: generate code for an expression, catching and reporting
855 * any completion failures.
856 * @param tree The expression to be visited.
857 * @param pt The expression's expected type (proto-type).
858 */
859 public Item genExpr(JCTree tree, Type pt) {
860 Type prevPt = this.pt;
861 try {
862 if (tree.type.constValue() != null) {
863 // Short circuit any expressions which are constants
864 tree.accept(classReferenceVisitor);
865 checkStringConstant(tree.pos(), tree.type.constValue());
866 result = items.makeImmediateItem(tree.type, tree.type.constValue());
867 } else {
868 this.pt = pt;
869 tree.accept(this);
870 }
871 return result.coerce(pt);
872 } catch (CompletionFailure ex) {
873 chk.completionError(tree.pos(), ex);
874 code.state.stacksize = 1;
875 return items.makeStackItem(pt);
876 } finally {
877 this.pt = prevPt;
878 }
879 }
880
881 /** Derived visitor method: generate code for a list of method arguments.
882 * @param trees The argument expressions to be visited.
883 * @param pts The expression's expected types (i.e. the formal parameter
884 * types of the invoked method).
885 */
886 public void genArgs(List<JCExpression> trees, List<Type> pts) {
887 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
888 genExpr(l.head, pts.head).load();
889 pts = pts.tail;
890 }
891 // require lists be of same length
892 Assert.check(pts.isEmpty());
893 }
894
895 /* ************************************************************************
896 * Visitor methods for statements and definitions
897 *************************************************************************/
898
899 /** Thrown when the byte code size exceeds limit.
900 */
901 public static class CodeSizeOverflow extends RuntimeException {
902 private static final long serialVersionUID = 0;
903 public CodeSizeOverflow() {}
904 }
905
906 public void visitMethodDef(JCMethodDecl tree) {
907 // Create a new local environment that points pack at method
908 // definition.
909 Env<GenContext> localEnv = env.dup(tree);
910 localEnv.enclMethod = tree;
911 // The expected type of every return statement in this method
912 // is the method's return type.
913 this.pt = tree.sym.erasure(types).getReturnType();
914
915 checkDimension(tree.pos(), tree.sym.erasure(types));
916 genMethod(tree, localEnv, false);
917 }
918 //where
919 /** Generate code for a method.
920 * @param tree The tree representing the method definition.
921 * @param env The environment current for the method body.
922 * @param fatcode A flag that indicates whether all jumps are
923 * within 32K. We first invoke this method under
924 * the assumption that fatcode == false, i.e. all
925 * jumps are within 32K. If this fails, fatcode
926 * is set to true and we try again.
927 */
928 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
929 MethodSymbol meth = tree.sym;
930 int extras = 0;
931 // Count up extra parameters
932 if (meth.isConstructor()) {
933 extras++;
934 if (meth.enclClass().isInner() &&
935 !meth.enclClass().isStatic()) {
936 extras++;
937 }
938 } else if ((tree.mods.flags & STATIC) == 0) {
939 extras++;
940 }
941 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
942 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
943 ClassFile.MAX_PARAMETERS) {
944 log.error(tree.pos(), Errors.LimitParameters);
945 nerrs++;
946 }
947
948 else if (tree.body != null) {
949 // Create a new code structure and initialize it.
950 int startpcCrt = initCode(tree, env, fatcode);
951
952 try {
953 genStat(tree.body, env);
954 } catch (CodeSizeOverflow e) {
955 // Failed due to code limit, try again with jsr/ret
956 startpcCrt = initCode(tree, env, fatcode);
957 genStat(tree.body, env);
958 }
959
960 if (code.state.stacksize != 0) {
961 log.error(tree.body.pos(), Errors.StackSimError(tree.sym));
962 throw new AssertionError();
963 }
964
965 // If last statement could complete normally, insert a
966 // return at the end.
967 if (code.isAlive()) {
968 code.statBegin(TreeInfo.endPos(tree.body));
969 if (env.enclMethod == null ||
970 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
971 code.emitop0(return_);
972 } else if (env.enclMethod.sym.isValueFactory(staticInitValueFactory)) {
973 items.makeLocalItem(env.enclMethod.factoryProduct).load();
974 code.emitop0(areturn);
975 } else {
976 // sometime dead code seems alive (4415991);
977 // generate a small loop instead
978 int startpc = code.entryPoint();
979 CondItem c = items.makeCondItem(goto_);
980 code.resolve(c.jumpTrue(), startpc);
981 }
982 }
983 if (genCrt)
984 code.crt.put(tree.body,
985 CRT_BLOCK,
986 startpcCrt,
987 code.curCP());
988
989 code.endScopes(0);
990
991 // If we exceeded limits, panic
992 if (code.checkLimits(tree.pos(), log)) {
993 nerrs++;
994 return;
995 }
996
997 // If we generated short code but got a long jump, do it again
998 // with fatCode = true.
999 if (!fatcode && code.fatcode) genMethod(tree, env, true);
1000
1001 // Clean up
1002 if(stackMap == StackMapFormat.JSR202) {
1003 code.lastFrame = null;
1004 code.frameBeforeLast = null;
1005 }
1006
1007 // Compress exception table
1008 code.compressCatchTable();
1009
1010 // Fill in type annotation positions for exception parameters
1011 code.fillExceptionParameterPositions();
1012 }
1013 }
1014
1015 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1016 MethodSymbol meth = tree.sym;
1017
1018 // Create a new code structure.
1019 meth.code = code = new Code(meth,
1020 fatcode,
1021 lineDebugInfo ? toplevel.lineMap : null,
1022 varDebugInfo,
1023 stackMap,
1024 debugCode,
1025 genCrt ? new CRTable(tree, env.toplevel.endPositions)
1026 : null,
1027 syms,
1028 types,
1029 pool);
1030 items = new Items(pool, code, syms, types);
1031 if (code.debugCode) {
1032 System.err.println(meth + " for body " + tree);
1033 }
1034
1035 // If method is not static, create a new local variable address
1036 // for `this'.
1037 if ((tree.mods.flags & STATIC) == 0) {
1038 Type selfType = meth.owner.type;
1039 if (meth.isConstructor() && selfType != syms.objectType)
1040 selfType = UninitializedType.uninitializedThis(selfType);
1041 code.setDefined(
1042 code.newLocal(
1043 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1044 }
1045
1046 // Mark all parameters as defined from the beginning of
1047 // the method.
1048 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1049 checkDimension(l.head.pos(), l.head.sym.type);
1050 code.setDefined(code.newLocal(l.head.sym));
1051 }
1052
1053 // Get ready to generate code for method body.
1054 int startpcCrt = genCrt ? code.curCP() : 0;
1055 code.entryPoint();
1056
1057 // Suppress initial stackmap
1058 code.pendingStackMap = false;
1059
1060 return startpcCrt;
1061 }
1062
1063 private void synthesizeValueMethod(JCMethodDecl methodDecl) {
1064
1065 Name name; List<Type> argTypes; Type resType;
1066
1067 switch (methodDecl.name.toString()) {
1068 case "hashCode":
1069 name = names.hashCode;
1070 argTypes = List.of(methodDecl.sym.owner.type);
1071 resType = methodDecl.restype.type;
1072 break;
1073 case "equals":
1074 name = names.equals;
1075 argTypes = List.of(methodDecl.sym.owner.type, syms.objectType);
1076 resType = methodDecl.restype.type;
1077 break;
1078 case "toString":
1079 name = names.toString;
1080 argTypes = List.of(methodDecl.sym.owner.type);
1081 resType = methodDecl.restype.type;
1082 break;
1083 default:
1084 throw new AssertionError("Unexpected synthetic method body");
1085 }
1086
1087 Type.MethodType indyType = new Type.MethodType(argTypes,
1088 resType,
1089 List.nil(),
1090 syms.methodClass);
1091
1092 List<Type> bsm_staticArgs = List.of(syms.methodHandleLookupType,
1093 syms.stringType,
1094 syms.methodTypeType);
1095
1096 Symbol bsm = rs.resolveInternalMethod(methodDecl.pos(),
1097 getAttrEnv(),
1098 syms.valueBootstrapMethods,
1099 names.fromString("makeBootstrapMethod"),
1100 bsm_staticArgs,
1101 null);
1102
1103 Symbol.DynamicMethodSymbol dynSym = new Symbol.DynamicMethodSymbol(name,
1104 syms.noSymbol,
1105 ClassFile.REF_invokeStatic,
1106 (Symbol.MethodSymbol)bsm,
1107 indyType,
1108 NO_STATIC_ARGS);
1109
1110
1111 switch (methodDecl.name.toString()) {
1112 case "hashCode":
1113 code.emitop0(aload_0);
1114 items.makeDynamicItem(dynSym).invoke();
1115 code.emitop0(ireturn);
1116 return;
1117 case "equals":
1118 code.emitop0(aload_0);
1119 code.emitop0(aload_1);
1120 items.makeDynamicItem(dynSym).invoke();
1121 code.emitop0(ireturn);
1122 return;
1123 case "toString":
1124 code.emitop0(aload_0);
1125 items.makeDynamicItem(dynSym).invoke();
1126 code.emitop0(areturn);
1127 return;
1128 }
1129 }
1130
1131 public void visitVarDef(JCVariableDecl tree) {
1132 VarSymbol v = tree.sym;
1133 if (tree.init != null) {
1134 checkStringConstant(tree.init.pos(), v.getConstValue());
1135 if (v.getConstValue() == null || varDebugInfo) {
1136 Assert.check(code.isStatementStart());
1137 code.newLocal(v);
1138 genExpr(tree.init, v.erasure(types)).load();
1139 items.makeLocalItem(v).store();
1140 Assert.check(code.isStatementStart());
1141 }
1142 } else {
1143 code.newLocal(v);
1144 }
1145 checkDimension(tree.pos(), v.type);
1146 }
1147
1148 public void visitSkip(JCSkip tree) {
1149 }
1150
1151 public void visitBlock(JCBlock tree) {
1152 if ((tree.flags & SYNTHETIC) != 0 && env.tree.hasTag(METHODDEF) && (((JCMethodDecl) env.tree).sym.owner.flags() & VALUE) != 0) {
1153 synthesizeValueMethod((JCMethodDecl) env.tree);
1154 return;
1155 }
1156 int limit = code.nextreg;
1157 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1158 genStats(tree.stats, localEnv);
1159 // End the scope of all block-local variables in variable info.
1160 if (!env.tree.hasTag(METHODDEF)) {
1161 code.statBegin(tree.endpos);
1162 code.endScopes(limit);
1163 code.pendingStatPos = Position.NOPOS;
1164 }
1165 }
1166
1167 public void visitDoLoop(JCDoWhileLoop tree) {
1168 genLoop(tree, tree.body, tree.cond, List.nil(), false);
1169 }
1170
1171 public void visitWhileLoop(JCWhileLoop tree) {
1172 genLoop(tree, tree.body, tree.cond, List.nil(), true);
1173 }
1174
1175 public void visitWithField(JCWithField tree) {
1176 switch(tree.field.getTag()) {
1177 case IDENT:
1178 Symbol sym = ((JCIdent) tree.field).sym;
1179 items.makeThisItem().load();
1180 genExpr(tree.value, tree.field.type).load();
1181 sym = binaryQualifier(sym, env.enclClass.type);
1182 code.emitop2(withfield, pool.put(sym));
1183 result = items.makeStackItem(tree.type);
1184 break;
1185 case SELECT:
1186 JCFieldAccess fieldAccess = (JCFieldAccess) tree.field;
1187 sym = TreeInfo.symbol(fieldAccess);
1188 // JDK-8207332: To maintain the order of side effects, must compute value ahead of field
1189 genExpr(tree.value, tree.field.type).load();
1190 genExpr(fieldAccess.selected, fieldAccess.selected.type).load();
1191 if (Code.width(tree.field.type) == 2) {
1192 code.emitop0(dup_x2);
1193 code.emitop0(pop);
1194 } else {
1195 code.emitop0(swap);
1196 }
1197 sym = binaryQualifier(sym, fieldAccess.selected.type);
1198 code.emitop2(withfield, pool.put(sym));
1199 result = items.makeStackItem(tree.type);
1200 break;
1201 default:
1202 Assert.check(false);
1203 }
1204 }
1205
1206 public void visitForLoop(JCForLoop tree) {
1207 int limit = code.nextreg;
1208 genStats(tree.init, env);
1209 genLoop(tree, tree.body, tree.cond, tree.step, true);
1210 code.endScopes(limit);
1211 }
1212 //where
1213 /** Generate code for a loop.
1214 * @param loop The tree representing the loop.
1215 * @param body The loop's body.
1216 * @param cond The loop's controling condition.
1217 * @param step "Step" statements to be inserted at end of
1218 * each iteration.
1219 * @param testFirst True if the loop test belongs before the body.
1220 */
1221 private void genLoop(JCStatement loop,
1222 JCStatement body,
1223 JCExpression cond,
1224 List<JCExpressionStatement> step,
1225 boolean testFirst) {
1226 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1227 int startpc = code.entryPoint();
1228 if (testFirst) { //while or for loop
1229 CondItem c;
1230 if (cond != null) {
1231 code.statBegin(cond.pos);
1232 Assert.check(code.isStatementStart());
1233 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1234 } else {
1235 c = items.makeCondItem(goto_);
1236 }
1237 Chain loopDone = c.jumpFalse();
1238 code.resolve(c.trueJumps);
1239 Assert.check(code.isStatementStart());
1240 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1241 code.resolve(loopEnv.info.cont);
1242 genStats(step, loopEnv);
1243 code.resolve(code.branch(goto_), startpc);
1244 code.resolve(loopDone);
1245 } else {
1246 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1247 code.resolve(loopEnv.info.cont);
1248 genStats(step, loopEnv);
1249 if (code.isAlive()) {
1250 CondItem c;
1251 if (cond != null) {
1252 code.statBegin(cond.pos);
1253 Assert.check(code.isStatementStart());
1254 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1255 } else {
1256 c = items.makeCondItem(goto_);
1257 }
1258 code.resolve(c.jumpTrue(), startpc);
1259 Assert.check(code.isStatementStart());
1260 code.resolve(c.falseJumps);
1261 }
1262 }
1263 Chain exit = loopEnv.info.exit;
1264 if (exit != null) {
1265 code.resolve(exit);
1266 exit.state.defined.excludeFrom(code.nextreg);
1267 }
1268 }
1269
1270 public void visitForeachLoop(JCEnhancedForLoop tree) {
1271 throw new AssertionError(); // should have been removed by Lower.
1272 }
1273
1274 public void visitLabelled(JCLabeledStatement tree) {
1275 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1276 genStat(tree.body, localEnv, CRT_STATEMENT);
1277 Chain exit = localEnv.info.exit;
1278 if (exit != null) {
1279 code.resolve(exit);
1280 exit.state.defined.excludeFrom(code.nextreg);
1281 }
1282 }
1283
1284 public void visitSwitch(JCSwitch tree) {
1285 handleSwitch(tree, tree.selector, tree.cases);
1286 }
1287
1288 @Override
1289 public void visitSwitchExpression(JCSwitchExpression tree) {
1290 code.resolvePending();
1291 boolean prevInCondSwitchExpression = inCondSwitchExpression;
1292 try {
1293 inCondSwitchExpression = false;
1294 doHandleSwitchExpression(tree);
1295 } finally {
1296 inCondSwitchExpression = prevInCondSwitchExpression;
1297 }
1298 result = items.makeStackItem(pt);
1299 }
1300
1301 private void doHandleSwitchExpression(JCSwitchExpression tree) {
1302 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
1303 int limit = code.nextreg;
1304 try {
1305 stackBeforeSwitchExpression = List.nil();
1306 if (hasTry(tree)) {
1307 //if the switch expression contains try-catch, the catch handlers need to have
1308 //an empty stack. So stash whole stack to local variables, and restore it before
1309 //breaks:
1310 while (code.state.stacksize > 0) {
1311 Type type = code.state.peek();
1312 Name varName = names.fromString(target.syntheticNameChar() +
1313 "stack" +
1314 target.syntheticNameChar() +
1315 tree.pos +
1316 target.syntheticNameChar() +
1317 code.state.stacksize);
1318 VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type,
1319 this.env.enclMethod.sym);
1320 LocalItem item = items.new LocalItem(type, code.newLocal(var));
1321 stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item);
1322 item.store();
1323 }
1324 }
1325 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
1326 try {
1327 handleSwitch(tree, tree.selector, tree.cases);
1328 } finally {
1329 code.setLetExprStackPos(prevLetExprStart);
1330 }
1331 } finally {
1332 stackBeforeSwitchExpression = prevStackBeforeSwitchExpression;
1333 code.endScopes(limit);
1334 }
1335 }
1336 //where:
1337 private boolean hasTry(JCSwitchExpression tree) {
1338 boolean[] hasTry = new boolean[1];
1339 new TreeScanner() {
1340 @Override
1341 public void visitTry(JCTry tree) {
1342 hasTry[0] = true;
1343 }
1344
1345 @Override
1346 public void visitClassDef(JCClassDecl tree) {
1347 }
1348
1349 @Override
1350 public void visitLambda(JCLambda tree) {
1351 }
1352 }.scan(tree);
1353 return hasTry[0];
1354 }
1355
1356 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases) {
1357 int limit = code.nextreg;
1358 Assert.check(!selector.type.hasTag(CLASS));
1359 int startpcCrt = genCrt ? code.curCP() : 0;
1360 Assert.check(code.isStatementStart());
1361 Item sel = genExpr(selector, syms.intType);
1362 if (cases.isEmpty()) {
1363 // We are seeing: switch <sel> {}
1364 sel.load().drop();
1365 if (genCrt)
1366 code.crt.put(TreeInfo.skipParens(selector),
1367 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1368 } else {
1369 // We are seeing a nonempty switch.
1370 sel.load();
1371 if (genCrt)
1372 code.crt.put(TreeInfo.skipParens(selector),
1373 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1374 Env<GenContext> switchEnv = env.dup(swtch, new GenContext());
1375 switchEnv.info.isSwitch = true;
1376
1377 // Compute number of labels and minimum and maximum label values.
1378 // For each case, store its label in an array.
1379 int lo = Integer.MAX_VALUE; // minimum label.
1380 int hi = Integer.MIN_VALUE; // maximum label.
1381 int nlabels = 0; // number of labels.
1382
1383 int[] labels = new int[cases.length()]; // the label array.
1384 int defaultIndex = -1; // the index of the default clause.
1385
1386 List<JCCase> l = cases;
1387 for (int i = 0; i < labels.length; i++) {
1388 if (l.head.pats.nonEmpty()) {
1389 Assert.check(l.head.pats.size() == 1);
1390 int val = ((Number)l.head.pats.head.type.constValue()).intValue();
1391 labels[i] = val;
1392 if (val < lo) lo = val;
1393 if (hi < val) hi = val;
1394 nlabels++;
1395 } else {
1396 Assert.check(defaultIndex == -1);
1397 defaultIndex = i;
1398 }
1399 l = l.tail;
1400 }
1401
1402 // Determine whether to issue a tableswitch or a lookupswitch
1403 // instruction.
1404 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1405 long table_time_cost = 3; // comparisons
1406 long lookup_space_cost = 3 + 2 * (long) nlabels;
1407 long lookup_time_cost = nlabels;
1408 int opcode =
1409 nlabels > 0 &&
1410 table_space_cost + 3 * table_time_cost <=
1411 lookup_space_cost + 3 * lookup_time_cost
1412 ?
1413 tableswitch : lookupswitch;
1414
1415 int startpc = code.curCP(); // the position of the selector operation
1416 code.emitop0(opcode);
1417 code.align(4);
1418 int tableBase = code.curCP(); // the start of the jump table
1419 int[] offsets = null; // a table of offsets for a lookupswitch
1420 code.emit4(-1); // leave space for default offset
1421 if (opcode == tableswitch) {
1422 code.emit4(lo); // minimum label
1423 code.emit4(hi); // maximum label
1424 for (long i = lo; i <= hi; i++) { // leave space for jump table
1425 code.emit4(-1);
1426 }
1427 } else {
1428 code.emit4(nlabels); // number of labels
1429 for (int i = 0; i < nlabels; i++) {
1430 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1431 }
1432 offsets = new int[labels.length];
1433 }
1434 Code.State stateSwitch = code.state.dup();
1435 code.markDead();
1436
1437 // For each case do:
1438 l = cases;
1439 for (int i = 0; i < labels.length; i++) {
1440 JCCase c = l.head;
1441 l = l.tail;
1442
1443 int pc = code.entryPoint(stateSwitch);
1444 // Insert offset directly into code or else into the
1445 // offsets table.
1446 if (i != defaultIndex) {
1447 if (opcode == tableswitch) {
1448 code.put4(
1449 tableBase + 4 * (labels[i] - lo + 3),
1450 pc - startpc);
1451 } else {
1452 offsets[i] = pc - startpc;
1453 }
1454 } else {
1455 code.put4(tableBase, pc - startpc);
1456 }
1457
1458 // Generate code for the statements in this case.
1459 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1460 }
1461
1462 // Resolve all breaks.
1463 Chain exit = switchEnv.info.exit;
1464 if (exit != null) {
1465 code.resolve(exit);
1466 exit.state.defined.excludeFrom(limit);
1467 }
1468
1469 // If we have not set the default offset, we do so now.
1470 if (code.get4(tableBase) == -1) {
1471 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1472 }
1473
1474 if (opcode == tableswitch) {
1475 // Let any unfilled slots point to the default case.
1476 int defaultOffset = code.get4(tableBase);
1477 for (long i = lo; i <= hi; i++) {
1478 int t = (int)(tableBase + 4 * (i - lo + 3));
1479 if (code.get4(t) == -1)
1480 code.put4(t, defaultOffset);
1481 }
1482 } else {
1483 // Sort non-default offsets and copy into lookup table.
1484 if (defaultIndex >= 0)
1485 for (int i = defaultIndex; i < labels.length - 1; i++) {
1486 labels[i] = labels[i+1];
1487 offsets[i] = offsets[i+1];
1488 }
1489 if (nlabels > 0)
1490 qsort2(labels, offsets, 0, nlabels - 1);
1491 for (int i = 0; i < nlabels; i++) {
1492 int caseidx = tableBase + 8 * (i + 1);
1493 code.put4(caseidx, labels[i]);
1494 code.put4(caseidx + 4, offsets[i]);
1495 }
1496 }
1497 }
1498 code.endScopes(limit);
1499 }
1500 //where
1501 /** Sort (int) arrays of keys and values
1502 */
1503 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1504 int i = lo;
1505 int j = hi;
1506 int pivot = keys[(i+j)/2];
1507 do {
1508 while (keys[i] < pivot) i++;
1509 while (pivot < keys[j]) j--;
1510 if (i <= j) {
1511 int temp1 = keys[i];
1512 keys[i] = keys[j];
1513 keys[j] = temp1;
1514 int temp2 = values[i];
1515 values[i] = values[j];
1516 values[j] = temp2;
1517 i++;
1518 j--;
1519 }
1520 } while (i <= j);
1521 if (lo < j) qsort2(keys, values, lo, j);
1522 if (i < hi) qsort2(keys, values, i, hi);
1523 }
1524
1525 public void visitSynchronized(JCSynchronized tree) {
1526 int limit = code.nextreg;
1527 // Generate code to evaluate lock and save in temporary variable.
1528 final LocalItem lockVar = makeTemp(syms.objectType);
1529 Assert.check(code.isStatementStart());
1530 genExpr(tree.lock, tree.lock.type).load().duplicate();
1531 lockVar.store();
1532
1533 // Generate code to enter monitor.
1534 code.emitop0(monitorenter);
1535 code.state.lock(lockVar.reg);
1536
1537 // Generate code for a try statement with given body, no catch clauses
1538 // in a new environment with the "exit-monitor" operation as finalizer.
1539 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1540 syncEnv.info.finalize = new GenFinalizer() {
1541 void gen() {
1542 genLast();
1543 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1544 syncEnv.info.gaps.append(code.curCP());
1545 }
1546 void genLast() {
1547 if (code.isAlive()) {
1548 lockVar.load();
1549 code.emitop0(monitorexit);
1550 code.state.unlock(lockVar.reg);
1551 }
1552 }
1553 };
1554 syncEnv.info.gaps = new ListBuffer<>();
1555 genTry(tree.body, List.nil(), syncEnv);
1556 code.endScopes(limit);
1557 }
1558
1559 public void visitTry(final JCTry tree) {
1560 // Generate code for a try statement with given body and catch clauses,
1561 // in a new environment which calls the finally block if there is one.
1562 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1563 final Env<GenContext> oldEnv = env;
1564 tryEnv.info.finalize = new GenFinalizer() {
1565 void gen() {
1566 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1567 tryEnv.info.gaps.append(code.curCP());
1568 genLast();
1569 }
1570 void genLast() {
1571 if (tree.finalizer != null)
1572 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1573 }
1574 boolean hasFinalizer() {
1575 return tree.finalizer != null;
1576 }
1577
1578 @Override
1579 void afterBody() {
1580 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1581 //for body-only finally, remove the GenFinalizer after try body
1582 //so that the finally is not generated to catch bodies:
1583 tryEnv.info.finalize = null;
1584 }
1585 }
1586
1587 };
1588 tryEnv.info.gaps = new ListBuffer<>();
1589 genTry(tree.body, tree.catchers, tryEnv);
1590 }
1591 //where
1592 /** Generate code for a try or synchronized statement
1593 * @param body The body of the try or synchronized statement.
1594 * @param catchers The lis of catch clauses.
1595 * @param env the environment current for the body.
1596 */
1597 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1598 int limit = code.nextreg;
1599 int startpc = code.curCP();
1600 Code.State stateTry = code.state.dup();
1601 genStat(body, env, CRT_BLOCK);
1602 int endpc = code.curCP();
1603 List<Integer> gaps = env.info.gaps.toList();
1604 code.statBegin(TreeInfo.endPos(body));
1605 genFinalizer(env);
1606 code.statBegin(TreeInfo.endPos(env.tree));
1607 Chain exitChain = code.branch(goto_);
1608 endFinalizerGap(env);
1609 env.info.finalize.afterBody();
1610 boolean hasFinalizer =
1611 env.info.finalize != null &&
1612 env.info.finalize.hasFinalizer();
1613 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1614 // start off with exception on stack
1615 code.entryPoint(stateTry, l.head.param.sym.type);
1616 genCatch(l.head, env, startpc, endpc, gaps);
1617 genFinalizer(env);
1618 if (hasFinalizer || l.tail.nonEmpty()) {
1619 code.statBegin(TreeInfo.endPos(env.tree));
1620 exitChain = Code.mergeChains(exitChain,
1621 code.branch(goto_));
1622 }
1623 endFinalizerGap(env);
1624 }
1625 if (hasFinalizer) {
1626 // Create a new register segement to avoid allocating
1627 // the same variables in finalizers and other statements.
1628 code.newRegSegment();
1629
1630 // Add a catch-all clause.
1631
1632 // start off with exception on stack
1633 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1634
1635 // Register all exception ranges for catch all clause.
1636 // The range of the catch all clause is from the beginning
1637 // of the try or synchronized block until the present
1638 // code pointer excluding all gaps in the current
1639 // environment's GenContext.
1640 int startseg = startpc;
1641 while (env.info.gaps.nonEmpty()) {
1642 int endseg = env.info.gaps.next().intValue();
1643 registerCatch(body.pos(), startseg, endseg,
1644 catchallpc, 0);
1645 startseg = env.info.gaps.next().intValue();
1646 }
1647 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1648 code.markStatBegin();
1649
1650 Item excVar = makeTemp(syms.throwableType);
1651 excVar.store();
1652 genFinalizer(env);
1653 code.resolvePending();
1654 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1655 code.markStatBegin();
1656
1657 excVar.load();
1658 registerCatch(body.pos(), startseg,
1659 env.info.gaps.next().intValue(),
1660 catchallpc, 0);
1661 code.emitop0(athrow);
1662 code.markDead();
1663
1664 // If there are jsr's to this finalizer, ...
1665 if (env.info.cont != null) {
1666 // Resolve all jsr's.
1667 code.resolve(env.info.cont);
1668
1669 // Mark statement line number
1670 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1671 code.markStatBegin();
1672
1673 // Save return address.
1674 LocalItem retVar = makeTemp(syms.throwableType);
1675 retVar.store();
1676
1677 // Generate finalizer code.
1678 env.info.finalize.genLast();
1679
1680 // Return.
1681 code.emitop1w(ret, retVar.reg);
1682 code.markDead();
1683 }
1684 }
1685 // Resolve all breaks.
1686 code.resolve(exitChain);
1687
1688 code.endScopes(limit);
1689 }
1690
1691 /** Generate code for a catch clause.
1692 * @param tree The catch clause.
1693 * @param env The environment current in the enclosing try.
1694 * @param startpc Start pc of try-block.
1695 * @param endpc End pc of try-block.
1696 */
1697 void genCatch(JCCatch tree,
1698 Env<GenContext> env,
1699 int startpc, int endpc,
1700 List<Integer> gaps) {
1701 if (startpc != endpc) {
1702 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs
1703 = catchTypesWithAnnotations(tree);
1704 while (gaps.nonEmpty()) {
1705 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1706 JCExpression subCatch = subCatch1.snd;
1707 int catchType = makeRef(tree.pos(), subCatch.type);
1708 int end = gaps.head.intValue();
1709 registerCatch(tree.pos(),
1710 startpc, end, code.curCP(),
1711 catchType);
1712 for (Attribute.TypeCompound tc : subCatch1.fst) {
1713 tc.position.setCatchInfo(catchType, startpc);
1714 }
1715 }
1716 gaps = gaps.tail;
1717 startpc = gaps.head.intValue();
1718 gaps = gaps.tail;
1719 }
1720 if (startpc < endpc) {
1721 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1722 JCExpression subCatch = subCatch1.snd;
1723 int catchType = makeRef(tree.pos(), subCatch.type);
1724 registerCatch(tree.pos(),
1725 startpc, endpc, code.curCP(),
1726 catchType);
1727 for (Attribute.TypeCompound tc : subCatch1.fst) {
1728 tc.position.setCatchInfo(catchType, startpc);
1729 }
1730 }
1731 }
1732 VarSymbol exparam = tree.param.sym;
1733 code.statBegin(tree.pos);
1734 code.markStatBegin();
1735 int limit = code.nextreg;
1736 code.newLocal(exparam);
1737 items.makeLocalItem(exparam).store();
1738 code.statBegin(TreeInfo.firstStatPos(tree.body));
1739 genStat(tree.body, env, CRT_BLOCK);
1740 code.endScopes(limit);
1741 code.statBegin(TreeInfo.endPos(tree.body));
1742 }
1743 }
1744 // where
1745 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) {
1746 return TreeInfo.isMultiCatch(tree) ?
1747 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) :
1748 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype));
1749 }
1750 // where
1751 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) {
1752 List<JCExpression> alts = tree.alternatives;
1753 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head));
1754 alts = alts.tail;
1755
1756 while(alts != null && alts.head != null) {
1757 JCExpression alt = alts.head;
1758 if (alt instanceof JCAnnotatedType) {
1759 JCAnnotatedType a = (JCAnnotatedType)alt;
1760 res = res.prepend(new Pair<>(annotate.fromAnnotations(a.annotations), alt));
1761 } else {
1762 res = res.prepend(new Pair<>(List.nil(), alt));
1763 }
1764 alts = alts.tail;
1765 }
1766 return res.reverse();
1767 }
1768
1769 /** Register a catch clause in the "Exceptions" code-attribute.
1770 */
1771 void registerCatch(DiagnosticPosition pos,
1772 int startpc, int endpc,
1773 int handler_pc, int catch_type) {
1774 char startpc1 = (char)startpc;
1775 char endpc1 = (char)endpc;
1776 char handler_pc1 = (char)handler_pc;
1777 if (startpc1 == startpc &&
1778 endpc1 == endpc &&
1779 handler_pc1 == handler_pc) {
1780 code.addCatch(startpc1, endpc1, handler_pc1,
1781 (char)catch_type);
1782 } else {
1783 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1784 nerrs++;
1785 }
1786 }
1787
1788 public void visitIf(JCIf tree) {
1789 int limit = code.nextreg;
1790 Chain thenExit = null;
1791 Assert.check(code.isStatementStart());
1792 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1793 CRT_FLOW_CONTROLLER);
1794 Chain elseChain = c.jumpFalse();
1795 Assert.check(code.isStatementStart());
1796 if (!c.isFalse()) {
1797 code.resolve(c.trueJumps);
1798 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1799 thenExit = code.branch(goto_);
1800 }
1801 if (elseChain != null) {
1802 code.resolve(elseChain);
1803 if (tree.elsepart != null) {
1804 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1805 }
1806 }
1807 code.resolve(thenExit);
1808 code.endScopes(limit);
1809 Assert.check(code.isStatementStart());
1810 }
1811
1812 public void visitExec(JCExpressionStatement tree) {
1813 // Optimize x++ to ++x and x-- to --x.
1814 JCExpression e = tree.expr;
1815 switch (e.getTag()) {
1816 case POSTINC:
1817 ((JCUnary) e).setTag(PREINC);
1818 break;
1819 case POSTDEC:
1820 ((JCUnary) e).setTag(PREDEC);
1821 break;
1822 }
1823 Assert.check(code.isStatementStart());
1824 genExpr(tree.expr, tree.expr.type).drop();
1825 Assert.check(code.isStatementStart());
1826 }
1827
1828 public void visitBreak(JCBreak tree) {
1829 Assert.check(code.isStatementStart());
1830 final Env<GenContext> targetEnv;
1831 if (tree.isValueBreak()) {
1832 //restore stack as it was before the switch expression:
1833 for (LocalItem li : stackBeforeSwitchExpression) {
1834 li.load();
1835 }
1836 if (inCondSwitchExpression) {
1837 CondItem value = genCond(tree.value, CRT_FLOW_TARGET);
1838 Chain falseJumps = value.jumpFalse();
1839 targetEnv = unwindBreak(tree);
1840 code.resolve(value.trueJumps);
1841 Chain trueJumps = code.branch(goto_);
1842 if (switchExpressionTrueChain == null) {
1843 switchExpressionTrueChain = trueJumps;
1844 } else {
1845 switchExpressionTrueChain =
1846 Code.mergeChains(switchExpressionTrueChain, trueJumps);
1847 }
1848 if (switchExpressionFalseChain == null) {
1849 switchExpressionFalseChain = falseJumps;
1850 } else {
1851 switchExpressionFalseChain =
1852 Code.mergeChains(switchExpressionFalseChain, falseJumps);
1853 }
1854 } else {
1855 genExpr(tree.value, pt).load();
1856 code.state.forceStackTop(tree.target.type);
1857 targetEnv = unwindBreak(tree);
1858 targetEnv.info.addExit(code.branch(goto_));
1859 }
1860 } else {
1861 targetEnv = unwindBreak(tree);
1862 targetEnv.info.addExit(code.branch(goto_));
1863 }
1864 endFinalizerGaps(env, targetEnv);
1865 }
1866 //where:
1867 private Env<GenContext> unwindBreak(JCBreak tree) {
1868 int tmpPos = code.pendingStatPos;
1869 Env<GenContext> targetEnv = unwind(tree.target, env);
1870 code.pendingStatPos = tmpPos;
1871 return targetEnv;
1872 }
1873
1874 public void visitContinue(JCContinue tree) {
1875 int tmpPos = code.pendingStatPos;
1876 Env<GenContext> targetEnv = unwind(tree.target, env);
1877 code.pendingStatPos = tmpPos;
1878 Assert.check(code.isStatementStart());
1879 targetEnv.info.addCont(code.branch(goto_));
1880 endFinalizerGaps(env, targetEnv);
1881 }
1882
1883 public void visitReturn(JCReturn tree) {
1884 int limit = code.nextreg;
1885 final Env<GenContext> targetEnv;
1886
1887 /* Save and then restore the location of the return in case a finally
1888 * is expanded (with unwind()) in the middle of our bytecodes.
1889 */
1890 int tmpPos = code.pendingStatPos;
1891 if (tree.expr != null) {
1892 Assert.check(code.isStatementStart());
1893 Item r = genExpr(tree.expr, pt).load();
1894 if (hasFinally(env.enclMethod, env)) {
1895 r = makeTemp(pt);
1896 r.store();
1897 }
1898 targetEnv = unwind(env.enclMethod, env);
1899 code.pendingStatPos = tmpPos;
1900 r.load();
1901 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
1902 } else {
1903 targetEnv = unwind(env.enclMethod, env);
1904 code.pendingStatPos = tmpPos;
1905 code.emitop0(return_);
1906 }
1907 endFinalizerGaps(env, targetEnv);
1908 code.endScopes(limit);
1909 }
1910
1911 public void visitThrow(JCThrow tree) {
1912 Assert.check(code.isStatementStart());
1913 genExpr(tree.expr, tree.expr.type).load();
1914 code.emitop0(athrow);
1915 Assert.check(code.isStatementStart());
1916 }
1917
1918 /* ************************************************************************
1919 * Visitor methods for expressions
1920 *************************************************************************/
1921
1922 public void visitApply(JCMethodInvocation tree) {
1923 setTypeAnnotationPositions(tree.pos);
1924 // Generate code for method.
1925 Item m = genExpr(tree.meth, methodType);
1926 // Generate code for all arguments, where the expected types are
1927 // the parameters of the method's external type (that is, any implicit
1928 // outer instance of a super(...) call appears as first parameter).
1929 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
1930 genArgs(tree.args,
1931 msym.externalType(types).getParameterTypes());
1932 if (!msym.isDynamic()) {
1933 code.statBegin(tree.pos);
1934 }
1935 result = m.invoke();
1936 }
1937
1938 public void visitConditional(JCConditional tree) {
1939 Chain thenExit = null;
1940 code.statBegin(tree.cond.pos);
1941 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
1942 Chain elseChain = c.jumpFalse();
1943 if (!c.isFalse()) {
1944 code.resolve(c.trueJumps);
1945 int startpc = genCrt ? code.curCP() : 0;
1946 code.statBegin(tree.truepart.pos);
1947 genExpr(tree.truepart, pt).load();
1948 code.state.forceStackTop(tree.type);
1949 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
1950 startpc, code.curCP());
1951 thenExit = code.branch(goto_);
1952 }
1953 if (elseChain != null) {
1954 code.resolve(elseChain);
1955 int startpc = genCrt ? code.curCP() : 0;
1956 code.statBegin(tree.falsepart.pos);
1957 genExpr(tree.falsepart, pt).load();
1958 code.state.forceStackTop(tree.type);
1959 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
1960 startpc, code.curCP());
1961 }
1962 code.resolve(thenExit);
1963 result = items.makeStackItem(pt);
1964 }
1965
1966 private void setTypeAnnotationPositions(int treePos) {
1967 MethodSymbol meth = code.meth;
1968 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR
1969 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT;
1970
1971 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
1972 if (ta.hasUnknownPosition())
1973 ta.tryFixPosition();
1974
1975 if (ta.position.matchesPos(treePos))
1976 ta.position.updatePosOffset(code.cp);
1977 }
1978
1979 if (!initOrClinit)
1980 return;
1981
1982 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
1983 if (ta.hasUnknownPosition())
1984 ta.tryFixPosition();
1985
1986 if (ta.position.matchesPos(treePos))
1987 ta.position.updatePosOffset(code.cp);
1988 }
1989
1990 ClassSymbol clazz = meth.enclClass();
1991 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
1992 if (!s.getKind().isField())
1993 continue;
1994
1995 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
1996 if (ta.hasUnknownPosition())
1997 ta.tryFixPosition();
1998
1999 if (ta.position.matchesPos(treePos))
2000 ta.position.updatePosOffset(code.cp);
2001 }
2002 }
2003 }
2004
2005 public void visitNewClass(JCNewClass tree) {
2006 // Enclosing instances or anonymous classes should have been eliminated
2007 // by now.
2008 Assert.check(tree.encl == null && tree.def == null);
2009 setTypeAnnotationPositions(tree.pos);
2010
2011 code.emitop2(new_, makeRef(tree.pos(), tree.type));
2012 code.emitop0(dup);
2013
2014 // Generate code for all arguments, where the expected types are
2015 // the parameters of the constructor's external type (that is,
2016 // any implicit outer instance appears as first parameter).
2017 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
2018
2019 items.makeMemberItem(tree.constructor, true).invoke();
2020
2021 result = items.makeStackItem(tree.type);
2022 }
2023
2024 public void visitNewArray(JCNewArray tree) {
2025 setTypeAnnotationPositions(tree.pos);
2026
2027 if (tree.elems != null) {
2028 Type elemtype = types.elemtype(tree.type);
2029 loadIntConst(tree.elems.length());
2030 Item arr = makeNewArray(tree.pos(), tree.type, 1);
2031 int i = 0;
2032 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
2033 arr.duplicate();
2034 loadIntConst(i);
2035 i++;
2036 genExpr(l.head, elemtype).load();
2037 items.makeIndexedItem(elemtype).store();
2038 }
2039 result = arr;
2040 } else {
2041 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
2042 genExpr(l.head, syms.intType).load();
2043 }
2044 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
2045 }
2046 }
2047 //where
2048 /** Generate code to create an array with given element type and number
2049 * of dimensions.
2050 */
2051 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
2052 Type elemtype = types.elemtype(type);
2053 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
2054 log.error(pos, Errors.LimitDimensions);
2055 nerrs++;
2056 }
2057 int elemcode = Code.arraycode(elemtype);
2058 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
2059 code.emitAnewarray(makeRef(pos, elemtype, types.isValue(elemtype)), type);
2060 } else if (elemcode == 1) {
2061 code.emitMultianewarray(ndims, makeRef(pos, type), type);
2062 } else {
2063 code.emitNewarray(elemcode, type);
2064 }
2065 return items.makeStackItem(type);
2066 }
2067
2068 public void visitParens(JCParens tree) {
2069 result = genExpr(tree.expr, tree.expr.type);
2070 }
2071
2072 public void visitAssign(JCAssign tree) {
2073 Item l = genExpr(tree.lhs, tree.lhs.type);
2074 genExpr(tree.rhs, tree.lhs.type).load();
2075 if (tree.rhs.type.hasTag(BOT)) {
2076 /* This is just a case of widening reference conversion that per 5.1.5 simply calls
2077 for "regarding a reference as having some other type in a manner that can be proved
2078 correct at compile time."
2079 */
2080 code.state.forceStackTop(tree.lhs.type);
2081 }
2082 result = items.makeAssignItem(l);
2083 }
2084
2085 public void visitAssignop(JCAssignOp tree) {
2086 OperatorSymbol operator = tree.operator;
2087 Item l;
2088 if (operator.opcode == string_add) {
2089 l = concat.makeConcat(tree);
2090 } else {
2091 // Generate code for first expression
2092 l = genExpr(tree.lhs, tree.lhs.type);
2093
2094 // If we have an increment of -32768 to +32767 of a local
2095 // int variable we can use an incr instruction instead of
2096 // proceeding further.
2097 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
2098 l instanceof LocalItem &&
2099 tree.lhs.type.getTag().isSubRangeOf(INT) &&
2100 tree.rhs.type.getTag().isSubRangeOf(INT) &&
2101 tree.rhs.type.constValue() != null) {
2102 int ival = ((Number) tree.rhs.type.constValue()).intValue();
2103 if (tree.hasTag(MINUS_ASG)) ival = -ival;
2104 ((LocalItem)l).incr(ival);
2105 result = l;
2106 return;
2107 }
2108 // Otherwise, duplicate expression, load one copy
2109 // and complete binary operation.
2110 l.duplicate();
2111 l.coerce(operator.type.getParameterTypes().head).load();
2112 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
2113 }
2114 result = items.makeAssignItem(l);
2115 }
2116
2117 public void visitUnary(JCUnary tree) {
2118 OperatorSymbol operator = tree.operator;
2119 if (tree.hasTag(NOT)) {
2120 CondItem od = genCond(tree.arg, false);
2121 result = od.negate();
2122 } else {
2123 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
2124 switch (tree.getTag()) {
2125 case POS:
2126 result = od.load();
2127 break;
2128 case NEG:
2129 result = od.load();
2130 code.emitop0(operator.opcode);
2131 break;
2132 case COMPL:
2133 result = od.load();
2134 emitMinusOne(od.typecode);
2135 code.emitop0(operator.opcode);
2136 break;
2137 case PREINC: case PREDEC:
2138 od.duplicate();
2139 if (od instanceof LocalItem &&
2140 (operator.opcode == iadd || operator.opcode == isub)) {
2141 ((LocalItem)od).incr(tree.hasTag(PREINC) ? 1 : -1);
2142 result = od;
2143 } else {
2144 od.load();
2145 code.emitop0(one(od.typecode));
2146 code.emitop0(operator.opcode);
2147 // Perform narrowing primitive conversion if byte,
2148 // char, or short. Fix for 4304655.
2149 if (od.typecode != INTcode &&
2150 Code.truncate(od.typecode) == INTcode)
2151 code.emitop0(int2byte + od.typecode - BYTEcode);
2152 result = items.makeAssignItem(od);
2153 }
2154 break;
2155 case POSTINC: case POSTDEC:
2156 od.duplicate();
2157 if (od instanceof LocalItem &&
2158 (operator.opcode == iadd || operator.opcode == isub)) {
2159 Item res = od.load();
2160 ((LocalItem)od).incr(tree.hasTag(POSTINC) ? 1 : -1);
2161 result = res;
2162 } else {
2163 Item res = od.load();
2164 od.stash(od.typecode);
2165 code.emitop0(one(od.typecode));
2166 code.emitop0(operator.opcode);
2167 // Perform narrowing primitive conversion if byte,
2168 // char, or short. Fix for 4304655.
2169 if (od.typecode != INTcode &&
2170 Code.truncate(od.typecode) == INTcode)
2171 code.emitop0(int2byte + od.typecode - BYTEcode);
2172 od.store();
2173 result = res;
2174 }
2175 break;
2176 case NULLCHK:
2177 result = od.load();
2178 code.emitop0(dup);
2179 genNullCheck(tree);
2180 break;
2181 default:
2182 Assert.error();
2183 }
2184 }
2185 }
2186
2187 /** Generate a null check from the object value at stack top. */
2188 private void genNullCheck(JCTree tree) {
2189 code.statBegin(tree.pos);
2190 callMethod(tree.pos(), syms.objectsType, names.requireNonNull,
2191 List.of(syms.objectType), true);
2192 code.emitop0(pop);
2193 }
2194
2195 public void visitBinary(JCBinary tree) {
2196 OperatorSymbol operator = tree.operator;
2197 if (operator.opcode == string_add) {
2198 result = concat.makeConcat(tree);
2199 } else if (tree.hasTag(AND)) {
2200 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2201 if (!lcond.isFalse()) {
2202 Chain falseJumps = lcond.jumpFalse();
2203 code.resolve(lcond.trueJumps);
2204 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2205 result = items.
2206 makeCondItem(rcond.opcode,
2207 rcond.trueJumps,
2208 Code.mergeChains(falseJumps,
2209 rcond.falseJumps));
2210 } else {
2211 result = lcond;
2212 }
2213 } else if (tree.hasTag(OR)) {
2214 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2215 if (!lcond.isTrue()) {
2216 Chain trueJumps = lcond.jumpTrue();
2217 code.resolve(lcond.falseJumps);
2218 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2219 result = items.
2220 makeCondItem(rcond.opcode,
2221 Code.mergeChains(trueJumps, rcond.trueJumps),
2222 rcond.falseJumps);
2223 } else {
2224 result = lcond;
2225 }
2226 } else {
2227 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
2228 od.load();
2229 result = completeBinop(tree.lhs, tree.rhs, operator);
2230 }
2231 }
2232
2233
2234 /** Complete generating code for operation, with left operand
2235 * already on stack.
2236 * @param lhs The tree representing the left operand.
2237 * @param rhs The tree representing the right operand.
2238 * @param operator The operator symbol.
2239 */
2240 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2241 MethodType optype = (MethodType)operator.type;
2242 int opcode = operator.opcode;
2243 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2244 rhs.type.constValue() instanceof Number &&
2245 ((Number) rhs.type.constValue()).intValue() == 0) {
2246 opcode = opcode + (ifeq - if_icmpeq);
2247 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2248 TreeInfo.isNull(rhs)) {
2249 opcode = opcode + (if_acmp_null - if_acmpeq);
2250 } else {
2251 // The expected type of the right operand is
2252 // the second parameter type of the operator, except for
2253 // shifts with long shiftcount, where we convert the opcode
2254 // to a short shift and the expected type to int.
2255 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2256 if (opcode >= ishll && opcode <= lushrl) {
2257 opcode = opcode + (ishl - ishll);
2258 rtype = syms.intType;
2259 }
2260 // Generate code for right operand and load.
2261 genExpr(rhs, rtype).load();
2262 // If there are two consecutive opcode instructions,
2263 // emit the first now.
2264 if (opcode >= (1 << preShift)) {
2265 code.emitop0(opcode >> preShift);
2266 opcode = opcode & 0xFF;
2267 }
2268 }
2269 if (opcode >= ifeq && opcode <= if_acmpne ||
2270 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2271 return items.makeCondItem(opcode);
2272 } else {
2273 code.emitop0(opcode);
2274 return items.makeStackItem(optype.restype);
2275 }
2276 }
2277
2278 public void visitTypeCast(JCTypeCast tree) {
2279 result = genExpr(tree.expr, tree.clazz.type).load();
2280 setTypeAnnotationPositions(tree.pos);
2281 // Additional code is only needed if we cast to a reference type
2282 // which is not statically a supertype of the expression's type.
2283 // For basic types, the coerce(...) in genExpr(...) will do
2284 // the conversion.
2285 if (!tree.clazz.type.isPrimitive() &&
2286 !types.isSameType(tree.expr.type, tree.clazz.type) &&
2287 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2288 code.emitop2(checkcast, makeRef(tree.pos(), tree.clazz.type, types.isValue(tree.clazz.type)));
2289 }
2290 }
2291
2292 public void visitWildcard(JCWildcard tree) {
2293 throw new AssertionError(this.getClass().getName());
2294 }
2295
2296 public void visitTypeTest(JCInstanceOf tree) {
2297 genExpr(tree.expr, tree.expr.type).load();
2298 setTypeAnnotationPositions(tree.pos);
2299 code.emitop2(instanceof_, makeRef(tree.pos(), tree.clazz.type));
2300 result = items.makeStackItem(syms.booleanType);
2301 }
2302
2303 public void visitIndexed(JCArrayAccess tree) {
2304 genExpr(tree.indexed, tree.indexed.type).load();
2305 genExpr(tree.index, syms.intType).load();
2306 result = items.makeIndexedItem(tree.type);
2307 }
2308
2309 public void visitIdent(JCIdent tree) {
2310 Symbol sym = tree.sym;
2311 if (tree.name == names._this || tree.name == names._super) {
2312 Item res = tree.name == names._this
2313 ? items.makeThisItem()
2314 : items.makeSuperItem();
2315 if (sym.kind == MTH) {
2316 // Generate code to address the constructor.
2317 res.load();
2318 res = items.makeMemberItem(sym, true);
2319 }
2320 result = res;
2321 } else if (sym.kind == VAR && (sym.owner.kind == MTH || sym.owner.kind == VAR)) {
2322 result = items.makeLocalItem((VarSymbol)sym);
2323 } else if (isInvokeDynamic(sym)) {
2324 result = items.makeDynamicItem(sym);
2325 } else if ((sym.flags() & STATIC) != 0) {
2326 if (!isAccessSuper(env.enclMethod))
2327 sym = binaryQualifier(sym, env.enclClass.type);
2328 result = items.makeStaticItem(sym);
2329 } else {
2330 items.makeThisItem().load();
2331 sym = binaryQualifier(sym, env.enclClass.type);
2332 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym));
2333 }
2334 }
2335
2336 //where
2337 private boolean nonVirtualForPrivateAccess(Symbol sym) {
2338 boolean useVirtual = target.hasVirtualPrivateInvoke() &&
2339 !disableVirtualizedPrivateInvoke;
2340 return !useVirtual && ((sym.flags() & PRIVATE) != 0);
2341 }
2342
2343 public void visitSelect(JCFieldAccess tree) {
2344 Symbol sym = tree.sym;
2345
2346 if (tree.name == names._class) {
2347 code.emitLdc(makeRef(tree.pos(), tree.selected.type));
2348 result = items.makeStackItem(pt);
2349 return;
2350 } else if (tree.name == names._default) {
2351 code.emitop2(defaultvalue, makeRef(tree.pos(), tree.type));
2352 result = items.makeStackItem(tree.type);
2353 return;
2354 }
2355
2356 Symbol ssym = TreeInfo.symbol(tree.selected);
2357
2358 // Are we selecting via super?
2359 boolean selectSuper =
2360 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2361
2362 // Are we accessing a member of the superclass in an access method
2363 // resulting from a qualified super?
2364 boolean accessSuper = isAccessSuper(env.enclMethod);
2365
2366 Item base = (selectSuper)
2367 ? items.makeSuperItem()
2368 : genExpr(tree.selected, tree.selected.type);
2369
2370 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2371 // We are seeing a variable that is constant but its selecting
2372 // expression is not.
2373 if ((sym.flags() & STATIC) != 0) {
2374 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2375 base = base.load();
2376 base.drop();
2377 } else {
2378 base.load();
2379 genNullCheck(tree.selected);
2380 }
2381 result = items.
2382 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2383 } else {
2384 if (isInvokeDynamic(sym)) {
2385 result = items.makeDynamicItem(sym);
2386 return;
2387 } else {
2388 sym = binaryQualifier(sym, tree.selected.type);
2389 }
2390 if ((sym.flags() & STATIC) != 0) {
2391 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2392 base = base.load();
2393 base.drop();
2394 result = items.makeStaticItem(sym);
2395 } else {
2396 base.load();
2397 if (sym == syms.lengthVar) {
2398 code.emitop0(arraylength);
2399 result = items.makeStackItem(syms.intType);
2400 } else {
2401 result = items.
2402 makeMemberItem(sym,
2403 nonVirtualForPrivateAccess(sym) ||
2404 selectSuper || accessSuper);
2405 }
2406 }
2407 }
2408 }
2409
2410 public boolean isInvokeDynamic(Symbol sym) {
2411 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
2412 }
2413
2414 public void visitLiteral(JCLiteral tree) {
2415 if (tree.type.hasTag(BOT)) {
2416 code.emitop0(aconst_null);
2417 result = items.makeStackItem(tree.type);
2418 }
2419 else
2420 result = items.makeImmediateItem(tree.type, tree.value);
2421 }
2422
2423 public void visitLetExpr(LetExpr tree) {
2424 int limit = code.nextreg;
2425 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
2426 try {
2427 genStats(tree.defs, env);
2428 } finally {
2429 code.setLetExprStackPos(prevLetExprStart);
2430 }
2431 result = genExpr(tree.expr, tree.expr.type).load();
2432 code.endScopes(limit);
2433 }
2434
2435 private void generateReferencesToPrunedTree(ClassSymbol classSymbol, Pool pool) {
2436 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
2437 if (prunedInfo != null) {
2438 for (JCTree prunedTree: prunedInfo) {
2439 prunedTree.accept(classReferenceVisitor);
2440 }
2441 }
2442 }
2443
2444 /* ************************************************************************
2445 * main method
2446 *************************************************************************/
2447
2448 /** Generate code for a class definition.
2449 * @param env The attribution environment that belongs to the
2450 * outermost class containing this class definition.
2451 * We need this for resolving some additional symbols.
2452 * @param cdef The tree representing the class definition.
2453 * @return True if code is generated with no errors.
2454 */
2455 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2456 try {
2457 attrEnv = env;
2458 ClassSymbol c = cdef.sym;
2459 this.toplevel = env.toplevel;
2460 this.endPosTable = toplevel.endPositions;
2461 c.pool = pool;
2462 pool.reset();
2463 /* method normalizeDefs() can add references to external classes into the constant pool
2464 */
2465 cdef.defs = normalizeDefs(cdef.defs, c);
2466 cdef = transValues.translateTopLevelClass(cdef, make);
2467 generateReferencesToPrunedTree(c, pool);
2468 Env<GenContext> localEnv = new Env<>(cdef, new GenContext());
2469 localEnv.toplevel = env.toplevel;
2470 localEnv.enclClass = cdef;
2471
2472 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2473 genDef(l.head, localEnv);
2474 }
2475 if (pool.numEntries() > Pool.MAX_ENTRIES) {
2476 log.error(cdef.pos(), Errors.LimitPool);
2477 nerrs++;
2478 }
2479 if (nerrs != 0) {
2480 // if errors, discard code
2481 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2482 if (l.head.hasTag(METHODDEF))
2483 ((JCMethodDecl) l.head).sym.code = null;
2484 }
2485 }
2486 cdef.defs = List.nil(); // discard trees
2487 return nerrs == 0;
2488 } finally {
2489 // note: this method does NOT support recursion.
2490 attrEnv = null;
2491 this.env = null;
2492 toplevel = null;
2493 endPosTable = null;
2494 nerrs = 0;
2495 }
2496 }
2497
2498 /* ************************************************************************
2499 * Auxiliary classes
2500 *************************************************************************/
2501
2502 /** An abstract class for finalizer generation.
2503 */
2504 abstract class GenFinalizer {
2505 /** Generate code to clean up when unwinding. */
2506 abstract void gen();
2507
2508 /** Generate code to clean up at last. */
2509 abstract void genLast();
2510
2511 /** Does this finalizer have some nontrivial cleanup to perform? */
2512 boolean hasFinalizer() { return true; }
2513
2514 /** Should be invoked after the try's body has been visited. */
2515 void afterBody() {}
2516 }
2517
2518 /** code generation contexts,
2519 * to be used as type parameter for environments.
2520 */
2521 static class GenContext {
2522
2523 /** A chain for all unresolved jumps that exit the current environment.
2524 */
2525 Chain exit = null;
2526
2527 /** A chain for all unresolved jumps that continue in the
2528 * current environment.
2529 */
2530 Chain cont = null;
2531
2532 /** A closure that generates the finalizer of the current environment.
2533 * Only set for Synchronized and Try contexts.
2534 */
2535 GenFinalizer finalize = null;
2536
2537 /** Is this a switch statement? If so, allocate registers
2538 * even when the variable declaration is unreachable.
2539 */
2540 boolean isSwitch = false;
2541
2542 /** A list buffer containing all gaps in the finalizer range,
2543 * where a catch all exception should not apply.
2544 */
2545 ListBuffer<Integer> gaps = null;
2546
2547 /** Add given chain to exit chain.
2548 */
2549 void addExit(Chain c) {
2550 exit = Code.mergeChains(c, exit);
2551 }
2552
2553 /** Add given chain to cont chain.
2554 */
2555 void addCont(Chain c) {
2556 cont = Code.mergeChains(c, cont);
2557 }
2558 }
2559
2560 }