1 /*
2 * Copyright (c) 1999, 2021, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.tools.javac.jvm;
27
28 import java.util.HashMap;
29 import java.util.Map;
30
31 import com.sun.tools.javac.jvm.PoolConstant.LoadableConstant;
32 import com.sun.tools.javac.tree.TreeInfo.PosKind;
33 import com.sun.tools.javac.util.*;
34 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
35 import com.sun.tools.javac.util.List;
36 import com.sun.tools.javac.code.*;
37 import com.sun.tools.javac.code.Attribute.TypeCompound;
38 import com.sun.tools.javac.code.Symbol.VarSymbol;
39 import com.sun.tools.javac.comp.*;
40 import com.sun.tools.javac.tree.*;
41
42 import com.sun.tools.javac.code.Symbol.*;
43 import com.sun.tools.javac.code.Type.*;
44 import com.sun.tools.javac.jvm.Code.*;
45 import com.sun.tools.javac.jvm.Items.*;
46 import com.sun.tools.javac.resources.CompilerProperties.Errors;
47 import com.sun.tools.javac.tree.EndPosTable;
48 import com.sun.tools.javac.tree.JCTree.*;
49
50 import static com.sun.tools.javac.code.Flags.*;
51 import static com.sun.tools.javac.code.Kinds.Kind.*;
52 import static com.sun.tools.javac.code.TypeTag.*;
53 import static com.sun.tools.javac.jvm.ByteCodes.*;
54 import static com.sun.tools.javac.jvm.CRTFlags.*;
55 import static com.sun.tools.javac.main.Option.*;
56 import static com.sun.tools.javac.tree.JCTree.Tag.*;
57
58 /** This pass maps flat Java (i.e. without inner classes) to bytecodes.
59 *
60 * <p><b>This is NOT part of any supported API.
61 * If you write code that depends on this, you do so at your own risk.
62 * This code and its internal interfaces are subject to change or
63 * deletion without notice.</b>
64 */
65 public class Gen extends JCTree.Visitor {
66 private static final Object[] NO_STATIC_ARGS = new Object[0];
67 protected static final Context.Key<Gen> genKey = new Context.Key<>();
68
69 private final Log log;
70 private final Symtab syms;
71 private final Check chk;
72 private final Resolve rs;
73 private final TreeMaker make;
74 private final Names names;
75 private final Target target;
76 private final Name accessDollar;
77 private final Types types;
78 private final Lower lower;
79 private final Annotate annotate;
80 private final StringConcat concat;
81 private final TransValues transValues;
82
83 /** Format of stackmap tables to be generated. */
84 private final Code.StackMapFormat stackMap;
85
86 /** A type that serves as the expected type for all method expressions.
87 */
88 private final Type methodType;
89
90 public static Gen instance(Context context) {
91 Gen instance = context.get(genKey);
92 if (instance == null)
93 instance = new Gen(context);
94 return instance;
95 }
96
97 /** Constant pool writer, set by genClass.
98 */
99 final PoolWriter poolWriter;
100
101 protected Gen(Context context) {
102 context.put(genKey, this);
103
104 names = Names.instance(context);
105 log = Log.instance(context);
106 syms = Symtab.instance(context);
107 chk = Check.instance(context);
108 rs = Resolve.instance(context);
109 make = TreeMaker.instance(context);
110 target = Target.instance(context);
111 types = Types.instance(context);
112 concat = StringConcat.instance(context);
113
114 methodType = new MethodType(null, null, null, syms.methodClass);
115 accessDollar = names.
116 fromString("access" + target.syntheticNameChar());
117 lower = Lower.instance(context);
118 transValues = TransValues.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 disableVirtualizedPrivateInvoke = options.isSet("disableVirtualizedPrivateInvoke");
131 poolWriter = new PoolWriter(types, names);
132
133 // ignore cldc because we cannot have both stackmap formats
134 this.stackMap = StackMapFormat.JSR202;
135 annotate = Annotate.instance(context);
136 qualifiedSymbolCache = new HashMap<>();
137 }
138
139 /** Switches
140 */
141 private final boolean lineDebugInfo;
142 private final boolean varDebugInfo;
143 private final boolean genCrt;
144 private final boolean debugCode;
145 private boolean disableVirtualizedPrivateInvoke;
146
147 /** Code buffer, set by genMethod.
148 */
149 private Code code;
150
151 /** Items structure, set by genMethod.
152 */
153 private Items items;
154
155 /** Environment for symbol lookup, set by genClass
156 */
157 private Env<AttrContext> attrEnv;
158
159 /** The top level tree.
160 */
161 private JCCompilationUnit toplevel;
162
163 /** The number of code-gen errors in this class.
164 */
165 private int nerrs = 0;
166
167 /** An object containing mappings of syntax trees to their
168 * ending source positions.
169 */
170 EndPosTable endPosTable;
171
172 boolean inCondSwitchExpression;
173 Chain switchExpressionTrueChain;
174 Chain switchExpressionFalseChain;
175 List<LocalItem> stackBeforeSwitchExpression;
176 LocalItem switchResult;
177
178 /** Cache the symbol to reflect the qualifying type.
179 * key: corresponding type
180 * value: qualified symbol
181 */
182 Map<Type, Symbol> qualifiedSymbolCache;
183
184 /** Generate code to load an integer constant.
185 * @param n The integer to be loaded.
186 */
187 void loadIntConst(int n) {
188 items.makeImmediateItem(syms.intType, n).load();
189 }
190
191 /** The opcode that loads a zero constant of a given type code.
192 * @param tc The given type code (@see ByteCode).
193 */
194 public static int zero(int tc) {
195 switch(tc) {
196 case INTcode: case BYTEcode: case SHORTcode: case CHARcode:
197 return iconst_0;
198 case LONGcode:
199 return lconst_0;
200 case FLOATcode:
201 return fconst_0;
202 case DOUBLEcode:
203 return dconst_0;
204 default:
205 throw new AssertionError("zero");
206 }
207 }
208
209 /** The opcode that loads a one constant of a given type code.
210 * @param tc The given type code (@see ByteCode).
211 */
212 public static int one(int tc) {
213 return zero(tc) + 1;
214 }
215
216 /** Generate code to load -1 of the given type code (either int or long).
217 * @param tc The given type code (@see ByteCode).
218 */
219 void emitMinusOne(int tc) {
220 if (tc == LONGcode) {
221 items.makeImmediateItem(syms.longType, Long.valueOf(-1)).load();
222 } else {
223 code.emitop0(iconst_m1);
224 }
225 }
226
227 /** Construct a symbol to reflect the qualifying type that should
228 * appear in the byte code as per JLS 13.1.
229 *
230 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except
231 * for those cases where we need to work around VM bugs).
232 *
233 * For {@literal target <= 1.1}: If qualified variable or method is defined in a
234 * non-accessible class, clone it with the qualifier class as owner.
235 *
236 * @param sym The accessed symbol
237 * @param site The qualifier's type.
238 */
239 Symbol binaryQualifier(Symbol sym, Type site) {
240
241 if (site.hasTag(ARRAY)) {
242 if (sym == syms.lengthVar ||
243 sym.owner != syms.arrayClass)
244 return sym;
245 // array clone can be qualified by the array type in later targets
246 Symbol qualifier;
247 if ((qualifier = qualifiedSymbolCache.get(site)) == null) {
248 qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name, site, syms.noSymbol);
249 qualifiedSymbolCache.put(site, qualifier);
250 }
251 return sym.clone(qualifier);
252 }
253
254 if (sym.owner == site.tsym ||
255 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) {
256 return sym;
257 }
258
259 // leave alone methods inherited from Object
260 // JLS 13.1.
261 if (sym.owner == syms.objectType.tsym)
262 return sym;
263
264 return sym.clone(site.tsym);
265 }
266
267 /** Insert a reference to given type in the constant pool,
268 * checking for an array with too many dimensions;
269 * return the reference's index.
270 * @param type The type for which a reference is inserted.
271 */
272 int makeRef(DiagnosticPosition pos, Type type, boolean emitQtype) {
273 checkDimension(pos, type);
274 if (emitQtype) {
275 return poolWriter.putClass(new ConstantPoolQType(type, types));
276 } else {
277 return poolWriter.putClass(type);
278 }
279 }
280
281 /** Insert a reference to given type in the constant pool,
282 * checking for an array with too many dimensions;
283 * return the reference's index.
284 * @param type The type for which a reference is inserted.
285 */
286 int makeRef(DiagnosticPosition pos, Type type) {
287 return makeRef(pos, type, false);
288 }
289
290 /** Check if the given type is an array with too many dimensions.
291 */
292 private Type checkDimension(DiagnosticPosition pos, Type t) {
293 checkDimensionInternal(pos, t);
294 return t;
295 }
296
297 private void checkDimensionInternal(DiagnosticPosition pos, Type t) {
298 switch (t.getTag()) {
299 case METHOD:
300 checkDimension(pos, t.getReturnType());
301 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail)
302 checkDimension(pos, args.head);
303 break;
304 case ARRAY:
305 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) {
306 log.error(pos, Errors.LimitDimensions);
307 nerrs++;
308 }
309 break;
310 default:
311 break;
312 }
313 }
314
315 /** Create a temporary variable.
316 * @param type The variable's type.
317 */
318 LocalItem makeTemp(Type type) {
319 VarSymbol v = new VarSymbol(Flags.SYNTHETIC,
320 names.empty,
321 type,
322 env.enclMethod.sym);
323 code.newLocal(v);
324 return items.makeLocalItem(v);
325 }
326
327 /** Generate code to call a non-private method or constructor.
328 * @param pos Position to be used for error reporting.
329 * @param site The type of which the method is a member.
330 * @param name The method's name.
331 * @param argtypes The method's argument types.
332 * @param isStatic A flag that indicates whether we call a
333 * static or instance method.
334 */
335 void callMethod(DiagnosticPosition pos,
336 Type site, Name name, List<Type> argtypes,
337 boolean isStatic) {
338 Symbol msym = rs.
339 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null);
340 if (isStatic) items.makeStaticItem(msym).invoke();
341 else items.makeMemberItem(msym, name == names.init).invoke();
342 }
343
344 /** Is the given method definition an access method
345 * resulting from a qualified super? This is signified by an odd
346 * access code.
347 */
348 private boolean isAccessSuper(JCMethodDecl enclMethod) {
349 return
350 (enclMethod.mods.flags & SYNTHETIC) != 0 &&
351 isOddAccessName(enclMethod.name);
352 }
353
354 /** Does given name start with "access$" and end in an odd digit?
355 */
356 private boolean isOddAccessName(Name name) {
357 return
358 name.startsWith(accessDollar) &&
359 (name.getByteAt(name.getByteLength() - 1) & 1) == 1;
360 }
361
362 /* ************************************************************************
363 * Non-local exits
364 *************************************************************************/
365
366 /** Generate code to invoke the finalizer associated with given
367 * environment.
368 * Any calls to finalizers are appended to the environments `cont' chain.
369 * Mark beginning of gap in catch all range for finalizer.
370 */
371 void genFinalizer(Env<GenContext> env) {
372 if (code.isAlive() && env.info.finalize != null)
373 env.info.finalize.gen();
374 }
375
376 /** Generate code to call all finalizers of structures aborted by
377 * a non-local
378 * exit. Return target environment of the non-local exit.
379 * @param target The tree representing the structure that's aborted
380 * @param env The environment current at the non-local exit.
381 */
382 Env<GenContext> unwind(JCTree target, Env<GenContext> env) {
383 Env<GenContext> env1 = env;
384 while (true) {
385 genFinalizer(env1);
386 if (env1.tree == target) break;
387 env1 = env1.next;
388 }
389 return env1;
390 }
391
392 /** Mark end of gap in catch-all range for finalizer.
393 * @param env the environment which might contain the finalizer
394 * (if it does, env.info.gaps != null).
395 */
396 void endFinalizerGap(Env<GenContext> env) {
397 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1)
398 env.info.gaps.append(code.curCP());
399 }
400
401 /** Mark end of all gaps in catch-all ranges for finalizers of environments
402 * lying between, and including to two environments.
403 * @param from the most deeply nested environment to mark
404 * @param to the least deeply nested environment to mark
405 */
406 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) {
407 Env<GenContext> last = null;
408 while (last != to) {
409 endFinalizerGap(from);
410 last = from;
411 from = from.next;
412 }
413 }
414
415 /** Do any of the structures aborted by a non-local exit have
416 * finalizers that require an empty stack?
417 * @param target The tree representing the structure that's aborted
418 * @param env The environment current at the non-local exit.
419 */
420 boolean hasFinally(JCTree target, Env<GenContext> env) {
421 while (env.tree != target) {
422 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer())
423 return true;
424 env = env.next;
425 }
426 return false;
427 }
428
429 /* ************************************************************************
430 * Normalizing class-members.
431 *************************************************************************/
432
433 /** Distribute member initializer code into constructors and {@code <clinit>}
434 * method.
435 * @param defs The list of class member declarations.
436 * @param c The enclosing class.
437 */
438 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) {
439 ListBuffer<JCStatement> initCode = new ListBuffer<>();
440 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>();
441 ListBuffer<JCStatement> clinitCode = new ListBuffer<>();
442 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>();
443 ListBuffer<JCTree> methodDefs = new ListBuffer<>();
444 // Sort definitions into three listbuffers:
445 // - initCode for instance initializers
446 // - clinitCode for class initializers
447 // - methodDefs for method definitions
448 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
449 JCTree def = l.head;
450 switch (def.getTag()) {
451 case BLOCK:
452 JCBlock block = (JCBlock)def;
453 if ((block.flags & STATIC) != 0)
454 clinitCode.append(block);
455 else if ((block.flags & SYNTHETIC) == 0)
456 initCode.append(block);
457 break;
458 case METHODDEF:
459 methodDefs.append(def);
460 break;
461 case VARDEF:
462 JCVariableDecl vdef = (JCVariableDecl) def;
463 VarSymbol sym = vdef.sym;
464 checkDimension(vdef.pos(), sym.type);
465 if (vdef.init != null) {
466 if ((sym.flags() & STATIC) == 0) {
467 // Always initialize instance variables.
468 JCStatement init = make.at(vdef.pos()).
469 Assignment(sym, vdef.init);
470 initCode.append(init);
471 endPosTable.replaceTree(vdef, init);
472 initTAs.addAll(getAndRemoveNonFieldTAs(sym));
473 } else if (sym.getConstValue() == null) {
474 // Initialize class (static) variables only if
475 // they are not compile-time constants.
476 JCStatement init = make.at(vdef.pos).
477 Assignment(sym, vdef.init);
478 clinitCode.append(init);
479 endPosTable.replaceTree(vdef, init);
480 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym));
481 } else {
482 checkStringConstant(vdef.init.pos(), sym.getConstValue());
483 /* if the init contains a reference to an external class, add it to the
484 * constant's pool
485 */
486 vdef.init.accept(classReferenceVisitor);
487 }
488 }
489 break;
490 default:
491 Assert.error();
492 }
493 }
494 // Insert any instance initializers into all constructors.
495 if (initCode.length() != 0) {
496 List<JCStatement> inits = initCode.toList();
497 initTAs.addAll(c.getInitTypeAttributes());
498 List<Attribute.TypeCompound> initTAlist = initTAs.toList();
499 for (JCTree t : methodDefs) {
500 normalizeMethod((JCMethodDecl)t, inits, initTAlist);
501 }
502 }
503 // If there are class initializers, create a <clinit> method
504 // that contains them as its body.
505 if (clinitCode.length() != 0) {
506 MethodSymbol clinit = new MethodSymbol(
507 STATIC | (c.flags() & STRICTFP),
508 names.clinit,
509 new MethodType(
510 List.nil(), syms.voidType,
511 List.nil(), syms.methodClass),
512 c);
513 c.members().enter(clinit);
514 List<JCStatement> clinitStats = clinitCode.toList();
515 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
516 block.endpos = TreeInfo.endPos(clinitStats.last());
517 methodDefs.append(make.MethodDef(clinit, block));
518
519 if (!clinitTAs.isEmpty())
520 clinit.appendUniqueTypeAttributes(clinitTAs.toList());
521 if (!c.getClassInitTypeAttributes().isEmpty())
522 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes());
523 }
524 // Return all method definitions.
525 return methodDefs.toList();
526 }
527
528 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) {
529 List<TypeCompound> tas = sym.getRawTypeAttributes();
530 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>();
531 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>();
532 for (TypeCompound ta : tas) {
533 Assert.check(ta.getPosition().type != TargetType.UNKNOWN);
534 if (ta.getPosition().type == TargetType.FIELD) {
535 fieldTAs.add(ta);
536 } else {
537 nonfieldTAs.add(ta);
538 }
539 }
540 sym.setTypeAttributes(fieldTAs.toList());
541 return nonfieldTAs.toList();
542 }
543
544 /** Check a constant value and report if it is a string that is
545 * too large.
546 */
547 private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
548 if (nerrs != 0 || // only complain about a long string once
549 constValue == null ||
550 !(constValue instanceof String str) ||
551 str.length() < PoolWriter.MAX_STRING_LENGTH)
552 return;
553 log.error(pos, Errors.LimitString);
554 nerrs++;
555 }
556
557 /** Insert instance initializer code into initial constructor.
558 * @param md The tree potentially representing a
559 * constructor's definition.
560 * @param initCode The list of instance initializer statements.
561 * @param initTAs Type annotations from the initializer expression.
562 */
563 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<TypeCompound> initTAs) {
564 if (md.name == names.init && TreeInfo.isInitialConstructor(md)) {
565 // We are seeing a constructor that does not call another
566 // constructor of the same class.
567 List<JCStatement> stats = md.body.stats;
568 ListBuffer<JCStatement> newstats = new ListBuffer<>();
569
570 if (stats.nonEmpty()) {
571 // Copy initializers of synthetic variables generated in
572 // the translation of inner classes.
573 while (TreeInfo.isSyntheticInit(stats.head)) {
574 newstats.append(stats.head);
575 stats = stats.tail;
576 }
577 // Copy superclass constructor call
578 newstats.append(stats.head);
579 stats = stats.tail;
580 // Copy remaining synthetic initializers.
581 while (stats.nonEmpty() &&
582 TreeInfo.isSyntheticInit(stats.head)) {
583 newstats.append(stats.head);
584 stats = stats.tail;
585 }
586 // Now insert the initializer code.
587 newstats.appendList(initCode);
588 // And copy all remaining statements.
589 while (stats.nonEmpty()) {
590 newstats.append(stats.head);
591 stats = stats.tail;
592 }
593 }
594 md.body.stats = newstats.toList();
595 if (md.body.endpos == Position.NOPOS)
596 md.body.endpos = TreeInfo.endPos(md.body.stats.last());
597
598 md.sym.appendUniqueTypeAttributes(initTAs);
599 }
600 }
601
602 /* ************************************************************************
603 * Traversal methods
604 *************************************************************************/
605
606 /** Visitor argument: The current environment.
607 */
608 Env<GenContext> env;
609
610 /** Visitor argument: The expected type (prototype).
611 */
612 Type pt;
613
614 /** Visitor result: The item representing the computed value.
615 */
616 Item result;
617
618 /** Visitor method: generate code for a definition, catching and reporting
619 * any completion failures.
620 * @param tree The definition to be visited.
621 * @param env The environment current at the definition.
622 */
623 public void genDef(JCTree tree, Env<GenContext> env) {
624 Env<GenContext> prevEnv = this.env;
625 try {
626 this.env = env;
627 tree.accept(this);
628 } catch (CompletionFailure ex) {
629 chk.completionError(tree.pos(), ex);
630 } finally {
631 this.env = prevEnv;
632 }
633 }
634
635 /** Derived visitor method: check whether CharacterRangeTable
636 * should be emitted, if so, put a new entry into CRTable
637 * and call method to generate bytecode.
638 * If not, just call method to generate bytecode.
639 * @see #genStat(JCTree, Env)
640 *
641 * @param tree The tree to be visited.
642 * @param env The environment to use.
643 * @param crtFlags The CharacterRangeTable flags
644 * indicating type of the entry.
645 */
646 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
647 if (!genCrt) {
648 genStat(tree, env);
649 return;
650 }
651 int startpc = code.curCP();
652 genStat(tree, env);
653 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK;
654 code.crt.put(tree, crtFlags, startpc, code.curCP());
655 }
656
657 /** Derived visitor method: generate code for a statement.
658 */
659 public void genStat(JCTree tree, Env<GenContext> env) {
660 if (code.isAlive()) {
661 code.statBegin(tree.pos);
662 genDef(tree, env);
663 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) {
664 // variables whose declarations are in a switch
665 // can be used even if the decl is unreachable.
666 code.newLocal(((JCVariableDecl) tree).sym);
667 }
668 }
669
670 /** Derived visitor method: check whether CharacterRangeTable
671 * should be emitted, if so, put a new entry into CRTable
672 * and call method to generate bytecode.
673 * If not, just call method to generate bytecode.
674 * @see #genStats(List, Env)
675 *
676 * @param trees The list of trees to be visited.
677 * @param env The environment to use.
678 * @param crtFlags The CharacterRangeTable flags
679 * indicating type of the entry.
680 */
681 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
682 if (!genCrt) {
683 genStats(trees, env);
684 return;
685 }
686 if (trees.length() == 1) { // mark one statement with the flags
687 genStat(trees.head, env, crtFlags | CRT_STATEMENT);
688 } else {
689 int startpc = code.curCP();
690 genStats(trees, env);
691 code.crt.put(trees, crtFlags, startpc, code.curCP());
692 }
693 }
694
695 /** Derived visitor method: generate code for a list of statements.
696 */
697 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) {
698 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
699 genStat(l.head, env, CRT_STATEMENT);
700 }
701
702 /** Derived visitor method: check whether CharacterRangeTable
703 * should be emitted, if so, put a new entry into CRTable
704 * and call method to generate bytecode.
705 * If not, just call method to generate bytecode.
706 * @see #genCond(JCTree,boolean)
707 *
708 * @param tree The tree to be visited.
709 * @param crtFlags The CharacterRangeTable flags
710 * indicating type of the entry.
711 */
712 public CondItem genCond(JCTree tree, int crtFlags) {
713 if (!genCrt) return genCond(tree, false);
714 int startpc = code.curCP();
715 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
716 code.crt.put(tree, crtFlags, startpc, code.curCP());
717 return item;
718 }
719
720 /** Derived visitor method: generate code for a boolean
721 * expression in a control-flow context.
722 * @param _tree The expression to be visited.
723 * @param markBranches The flag to indicate that the condition is
724 * a flow controller so produced conditions
725 * should contain a proper tree to generate
726 * CharacterRangeTable branches for them.
727 */
728 public CondItem genCond(JCTree _tree, boolean markBranches) {
729 JCTree inner_tree = TreeInfo.skipParens(_tree);
730 if (inner_tree.hasTag(CONDEXPR)) {
731 JCConditional tree = (JCConditional)inner_tree;
732 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
733 if (cond.isTrue()) {
734 code.resolve(cond.trueJumps);
735 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
736 if (markBranches) result.tree = tree.truepart;
737 return result;
738 }
739 if (cond.isFalse()) {
740 code.resolve(cond.falseJumps);
741 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
742 if (markBranches) result.tree = tree.falsepart;
743 return result;
744 }
745 Chain secondJumps = cond.jumpFalse();
746 code.resolve(cond.trueJumps);
747 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
748 if (markBranches) first.tree = tree.truepart;
749 Chain falseJumps = first.jumpFalse();
750 code.resolve(first.trueJumps);
751 Chain trueJumps = code.branch(goto_);
752 code.resolve(secondJumps);
753 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
754 CondItem result = items.makeCondItem(second.opcode,
755 Code.mergeChains(trueJumps, second.trueJumps),
756 Code.mergeChains(falseJumps, second.falseJumps));
757 if (markBranches) result.tree = tree.falsepart;
758 return result;
759 } else if (inner_tree.hasTag(SWITCH_EXPRESSION)) {
760 code.resolvePending();
761
762 boolean prevInCondSwitchExpression = inCondSwitchExpression;
763 Chain prevSwitchExpressionTrueChain = switchExpressionTrueChain;
764 Chain prevSwitchExpressionFalseChain = switchExpressionFalseChain;
765 try {
766 inCondSwitchExpression = true;
767 switchExpressionTrueChain = null;
768 switchExpressionFalseChain = null;
769 try {
770 doHandleSwitchExpression((JCSwitchExpression) inner_tree);
771 } catch (CompletionFailure ex) {
772 chk.completionError(_tree.pos(), ex);
773 code.state.stacksize = 1;
774 }
775 CondItem result = items.makeCondItem(goto_,
776 switchExpressionTrueChain,
777 switchExpressionFalseChain);
778 if (markBranches) result.tree = _tree;
779 return result;
780 } finally {
781 inCondSwitchExpression = prevInCondSwitchExpression;
782 switchExpressionTrueChain = prevSwitchExpressionTrueChain;
783 switchExpressionFalseChain = prevSwitchExpressionFalseChain;
784 }
785 } else if (inner_tree.hasTag(LETEXPR) && ((LetExpr) inner_tree).needsCond) {
786 code.resolvePending();
787
788 LetExpr tree = (LetExpr) inner_tree;
789 int limit = code.nextreg;
790 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
791 try {
792 genStats(tree.defs, env);
793 } finally {
794 code.setLetExprStackPos(prevLetExprStart);
795 }
796 CondItem result = genCond(tree.expr, markBranches);
797 code.endScopes(limit);
798 return result;
799 } else {
800 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
801 if (markBranches) result.tree = _tree;
802 return result;
803 }
804 }
805
806 public Code getCode() {
807 return code;
808 }
809
810 public Items getItems() {
811 return items;
812 }
813
814 public Env<AttrContext> getAttrEnv() {
815 return attrEnv;
816 }
817
818 /** Visitor class for expressions which might be constant expressions.
819 * This class is a subset of TreeScanner. Intended to visit trees pruned by
820 * Lower as long as constant expressions looking for references to any
821 * ClassSymbol. Any such reference will be added to the constant pool so
822 * automated tools can detect class dependencies better.
823 */
824 class ClassReferenceVisitor extends JCTree.Visitor {
825
826 @Override
827 public void visitTree(JCTree tree) {}
828
829 @Override
830 public void visitBinary(JCBinary tree) {
831 tree.lhs.accept(this);
832 tree.rhs.accept(this);
833 }
834
835 @Override
836 public void visitSelect(JCFieldAccess tree) {
837 if (tree.selected.type.hasTag(CLASS)) {
838 makeRef(tree.selected.pos(), tree.selected.type);
839 }
840 }
841
842 @Override
843 public void visitIdent(JCIdent tree) {
844 if (tree.sym.owner instanceof ClassSymbol classSymbol) {
845 poolWriter.putClass(classSymbol);
846 }
847 }
848
849 @Override
850 public void visitConditional(JCConditional tree) {
851 tree.cond.accept(this);
852 tree.truepart.accept(this);
853 tree.falsepart.accept(this);
854 }
855
856 @Override
857 public void visitUnary(JCUnary tree) {
858 tree.arg.accept(this);
859 }
860
861 @Override
862 public void visitParens(JCParens tree) {
863 tree.expr.accept(this);
864 }
865
866 @Override
867 public void visitTypeCast(JCTypeCast tree) {
868 tree.expr.accept(this);
869 }
870 }
871
872 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor();
873
874 /** Visitor method: generate code for an expression, catching and reporting
875 * any completion failures.
876 * @param tree The expression to be visited.
877 * @param pt The expression's expected type (proto-type).
878 */
879 public Item genExpr(JCTree tree, Type pt) {
880 if (!code.isAlive()) {
881 return items.makeStackItem(pt);
882 }
883
884 Type prevPt = this.pt;
885 try {
886 if (tree.type.constValue() != null) {
887 // Short circuit any expressions which are constants
888 tree.accept(classReferenceVisitor);
889 checkStringConstant(tree.pos(), tree.type.constValue());
890 Symbol sym = TreeInfo.symbol(tree);
891 if (sym != null && isConstantDynamic(sym)) {
892 result = items.makeDynamicItem(sym);
893 } else {
894 result = items.makeImmediateItem(tree.type, tree.type.constValue());
895 }
896 } else {
897 this.pt = pt;
898 tree.accept(this);
899 }
900 return result.coerce(pt);
901 } catch (CompletionFailure ex) {
902 chk.completionError(tree.pos(), ex);
903 code.state.stacksize = 1;
904 return items.makeStackItem(pt);
905 } finally {
906 this.pt = prevPt;
907 }
908 }
909
910 public boolean isConstantDynamic(Symbol sym) {
911 return sym.kind == VAR &&
912 sym instanceof DynamicVarSymbol dynamicVarSymbol &&
913 dynamicVarSymbol.isDynamic();
914 }
915
916 /** Derived visitor method: generate code for a list of method arguments.
917 * @param trees The argument expressions to be visited.
918 * @param pts The expression's expected types (i.e. the formal parameter
919 * types of the invoked method).
920 */
921 public void genArgs(List<JCExpression> trees, List<Type> pts) {
922 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
923 genExpr(l.head, pts.head).load();
924 pts = pts.tail;
925 }
926 // require lists be of same length
927 Assert.check(pts.isEmpty());
928 }
929
930 /* ************************************************************************
931 * Visitor methods for statements and definitions
932 *************************************************************************/
933
934 /** Thrown when the byte code size exceeds limit.
935 */
936 public static class CodeSizeOverflow extends RuntimeException {
937 private static final long serialVersionUID = 0;
938 public CodeSizeOverflow() {}
939 }
940
941 public void visitMethodDef(JCMethodDecl tree) {
942 // Create a new local environment that points pack at method
943 // definition.
944 Env<GenContext> localEnv = env.dup(tree);
945 localEnv.enclMethod = tree;
946 // The expected type of every return statement in this method
947 // is the method's return type.
948 this.pt = tree.sym.erasure(types).getReturnType();
949
950 checkDimension(tree.pos(), tree.sym.erasure(types));
951 genMethod(tree, localEnv, false);
952 }
953 //where
954 /** Generate code for a method.
955 * @param tree The tree representing the method definition.
956 * @param env The environment current for the method body.
957 * @param fatcode A flag that indicates whether all jumps are
958 * within 32K. We first invoke this method under
959 * the assumption that fatcode == false, i.e. all
960 * jumps are within 32K. If this fails, fatcode
961 * is set to true and we try again.
962 */
963 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
964 MethodSymbol meth = tree.sym;
965 int extras = 0;
966 // Count up extra parameters
967 if (meth.isConstructor()) {
968 extras++;
969 if (meth.enclClass().isInner() &&
970 !meth.enclClass().isStatic()) {
971 extras++;
972 }
973 } else if ((tree.mods.flags & STATIC) == 0) {
974 extras++;
975 }
976 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
977 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
978 ClassFile.MAX_PARAMETERS) {
979 log.error(tree.pos(), Errors.LimitParameters);
980 nerrs++;
981 }
982
983 else if (tree.body != null) {
984 // Create a new code structure and initialize it.
985 int startpcCrt = initCode(tree, env, fatcode);
986
987 try {
988 genStat(tree.body, env);
989 } catch (CodeSizeOverflow e) {
990 // Failed due to code limit, try again with jsr/ret
991 startpcCrt = initCode(tree, env, fatcode);
992 genStat(tree.body, env);
993 }
994
995 if (code.state.stacksize != 0) {
996 log.error(tree.body.pos(), Errors.StackSimError(tree.sym));
997 throw new AssertionError();
998 }
999
1000 // If last statement could complete normally, insert a
1001 // return at the end.
1002 if (code.isAlive()) {
1003 code.statBegin(TreeInfo.endPos(tree.body));
1004 if (env.enclMethod == null ||
1005 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
1006 code.emitop0(return_);
1007 } else if (env.enclMethod.sym.isValueObjectFactory()) {
1008 items.makeLocalItem(env.enclMethod.factoryProduct).load();
1009 code.emitop0(areturn);
1010 } else {
1011 // sometime dead code seems alive (4415991);
1012 // generate a small loop instead
1013 int startpc = code.entryPoint();
1014 CondItem c = items.makeCondItem(goto_);
1015 code.resolve(c.jumpTrue(), startpc);
1016 }
1017 }
1018 if (genCrt)
1019 code.crt.put(tree.body,
1020 CRT_BLOCK,
1021 startpcCrt,
1022 code.curCP());
1023
1024 code.endScopes(0);
1025
1026 // If we exceeded limits, panic
1027 if (code.checkLimits(tree.pos(), log)) {
1028 nerrs++;
1029 return;
1030 }
1031
1032 // If we generated short code but got a long jump, do it again
1033 // with fatCode = true.
1034 if (!fatcode && code.fatcode) genMethod(tree, env, true);
1035
1036 // Clean up
1037 if(stackMap == StackMapFormat.JSR202) {
1038 code.lastFrame = null;
1039 code.frameBeforeLast = null;
1040 }
1041
1042 // Compress exception table
1043 code.compressCatchTable();
1044
1045 // Fill in type annotation positions for exception parameters
1046 code.fillExceptionParameterPositions();
1047 }
1048 }
1049
1050 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1051 MethodSymbol meth = tree.sym;
1052
1053 // Create a new code structure.
1054 meth.code = code = new Code(meth,
1055 fatcode,
1056 lineDebugInfo ? toplevel.lineMap : null,
1057 varDebugInfo,
1058 stackMap,
1059 debugCode,
1060 genCrt ? new CRTable(tree, env.toplevel.endPositions)
1061 : null,
1062 syms,
1063 types,
1064 poolWriter);
1065 items = new Items(poolWriter, code, syms, types);
1066 if (code.debugCode) {
1067 System.err.println(meth + " for body " + tree);
1068 }
1069
1070 // If method is not static, create a new local variable address
1071 // for `this'.
1072 if ((tree.mods.flags & STATIC) == 0) {
1073 Type selfType = meth.owner.type;
1074 if (meth.isConstructor() && selfType != syms.objectType)
1075 selfType = UninitializedType.uninitializedThis(selfType);
1076 code.setDefined(
1077 code.newLocal(
1078 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1079 }
1080
1081 // Mark all parameters as defined from the beginning of
1082 // the method.
1083 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1084 checkDimension(l.head.pos(), l.head.sym.type);
1085 code.setDefined(code.newLocal(l.head.sym));
1086 }
1087
1088 // Get ready to generate code for method body.
1089 int startpcCrt = genCrt ? code.curCP() : 0;
1090 code.entryPoint();
1091
1092 // Suppress initial stackmap
1093 code.pendingStackMap = false;
1094
1095 return startpcCrt;
1096 }
1097
1098 public void visitVarDef(JCVariableDecl tree) {
1099 VarSymbol v = tree.sym;
1100 if (tree.init != null) {
1101 checkStringConstant(tree.init.pos(), v.getConstValue());
1102 if (v.getConstValue() == null || varDebugInfo) {
1103 Assert.check(code.isStatementStart());
1104 code.newLocal(v);
1105 genExpr(tree.init, v.erasure(types)).load();
1106 items.makeLocalItem(v).store();
1107 Assert.check(code.isStatementStart());
1108 }
1109 } else {
1110 code.newLocal(v);
1111 }
1112 checkDimension(tree.pos(), v.type);
1113 Type localType = v.erasure(types);
1114 if (localType.requiresPreload(env.enclClass.sym)) {
1115 poolWriter.enterPreloadClass((ClassSymbol) localType.tsym);
1116 }
1117 }
1118
1119 public void visitSkip(JCSkip tree) {
1120 }
1121
1122 public void visitBlock(JCBlock tree) {
1123 int limit = code.nextreg;
1124 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1125 genStats(tree.stats, localEnv);
1126 // End the scope of all block-local variables in variable info.
1127 if (!env.tree.hasTag(METHODDEF)) {
1128 code.statBegin(tree.endpos);
1129 code.endScopes(limit);
1130 code.pendingStatPos = Position.NOPOS;
1131 }
1132 }
1133
1134 public void visitDoLoop(JCDoWhileLoop tree) {
1135 genLoop(tree, tree.body, tree.cond, List.nil(), false);
1136 }
1137
1138 public void visitWhileLoop(JCWhileLoop tree) {
1139 genLoop(tree, tree.body, tree.cond, List.nil(), true);
1140 }
1141
1142 public void visitWithField(JCWithField tree) {
1143 switch(tree.field.getTag()) {
1144 case IDENT:
1145 Symbol sym = ((JCIdent) tree.field).sym;
1146 items.makeThisItem().load();
1147 genExpr(tree.value, tree.field.type).load();
1148 sym = binaryQualifier(sym, env.enclClass.type);
1149 code.emitop2(withfield, sym, PoolWriter::putMember);
1150 result = items.makeStackItem(tree.type);
1151 break;
1152 case SELECT:
1153 JCFieldAccess fieldAccess = (JCFieldAccess) tree.field;
1154 sym = TreeInfo.symbol(fieldAccess);
1155 // JDK-8207332: To maintain the order of side effects, must compute value ahead of field
1156 genExpr(tree.value, tree.field.type).load();
1157 genExpr(fieldAccess.selected, fieldAccess.selected.type).load();
1158 if (Code.width(tree.field.type) == 2) {
1159 code.emitop0(dup_x2);
1160 code.emitop0(pop);
1161 } else {
1162 code.emitop0(swap);
1163 }
1164 sym = binaryQualifier(sym, fieldAccess.selected.type);
1165 code.emitop2(withfield, sym, PoolWriter::putMember);
1166 result = items.makeStackItem(tree.type);
1167 break;
1168 default:
1169 Assert.check(false);
1170 }
1171 }
1172
1173 public void visitForLoop(JCForLoop tree) {
1174 int limit = code.nextreg;
1175 genStats(tree.init, env);
1176 genLoop(tree, tree.body, tree.cond, tree.step, true);
1177 code.endScopes(limit);
1178 }
1179 //where
1180 /** Generate code for a loop.
1181 * @param loop The tree representing the loop.
1182 * @param body The loop's body.
1183 * @param cond The loop's controlling condition.
1184 * @param step "Step" statements to be inserted at end of
1185 * each iteration.
1186 * @param testFirst True if the loop test belongs before the body.
1187 */
1188 private void genLoop(JCStatement loop,
1189 JCStatement body,
1190 JCExpression cond,
1191 List<JCExpressionStatement> step,
1192 boolean testFirst) {
1193 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1194 int startpc = code.entryPoint();
1195 if (testFirst) { //while or for loop
1196 CondItem c;
1197 if (cond != null) {
1198 code.statBegin(cond.pos);
1199 Assert.check(code.isStatementStart());
1200 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1201 } else {
1202 c = items.makeCondItem(goto_);
1203 }
1204 Chain loopDone = c.jumpFalse();
1205 code.resolve(c.trueJumps);
1206 Assert.check(code.isStatementStart());
1207 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1208 code.resolve(loopEnv.info.cont);
1209 genStats(step, loopEnv);
1210 code.resolve(code.branch(goto_), startpc);
1211 code.resolve(loopDone);
1212 } else {
1213 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1214 code.resolve(loopEnv.info.cont);
1215 genStats(step, loopEnv);
1216 if (code.isAlive()) {
1217 CondItem c;
1218 if (cond != null) {
1219 code.statBegin(cond.pos);
1220 Assert.check(code.isStatementStart());
1221 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1222 } else {
1223 c = items.makeCondItem(goto_);
1224 }
1225 code.resolve(c.jumpTrue(), startpc);
1226 Assert.check(code.isStatementStart());
1227 code.resolve(c.falseJumps);
1228 }
1229 }
1230 Chain exit = loopEnv.info.exit;
1231 if (exit != null) {
1232 code.resolve(exit);
1233 exit.state.defined.excludeFrom(code.nextreg);
1234 }
1235 }
1236
1237 public void visitForeachLoop(JCEnhancedForLoop tree) {
1238 throw new AssertionError(); // should have been removed by Lower.
1239 }
1240
1241 public void visitLabelled(JCLabeledStatement tree) {
1242 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1243 genStat(tree.body, localEnv, CRT_STATEMENT);
1244 Chain exit = localEnv.info.exit;
1245 if (exit != null) {
1246 code.resolve(exit);
1247 exit.state.defined.excludeFrom(code.nextreg);
1248 }
1249 }
1250
1251 public void visitSwitch(JCSwitch tree) {
1252 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1253 }
1254
1255 @Override
1256 public void visitSwitchExpression(JCSwitchExpression tree) {
1257 code.resolvePending();
1258 boolean prevInCondSwitchExpression = inCondSwitchExpression;
1259 try {
1260 inCondSwitchExpression = false;
1261 doHandleSwitchExpression(tree);
1262 } finally {
1263 inCondSwitchExpression = prevInCondSwitchExpression;
1264 }
1265 result = items.makeStackItem(pt);
1266 }
1267
1268 private void doHandleSwitchExpression(JCSwitchExpression tree) {
1269 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
1270 LocalItem prevSwitchResult = switchResult;
1271 int limit = code.nextreg;
1272 try {
1273 stackBeforeSwitchExpression = List.nil();
1274 switchResult = null;
1275 if (hasTry(tree)) {
1276 //if the switch expression contains try-catch, the catch handlers need to have
1277 //an empty stack. So stash whole stack to local variables, and restore it before
1278 //breaks:
1279 while (code.state.stacksize > 0) {
1280 Type type = code.state.peek();
1281 Name varName = names.fromString(target.syntheticNameChar() +
1282 "stack" +
1283 target.syntheticNameChar() +
1284 tree.pos +
1285 target.syntheticNameChar() +
1286 code.state.stacksize);
1287 VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type,
1288 this.env.enclMethod.sym);
1289 LocalItem item = items.new LocalItem(type, code.newLocal(var));
1290 stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item);
1291 item.store();
1292 }
1293 switchResult = makeTemp(tree.type);
1294 }
1295 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
1296 try {
1297 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1298 } finally {
1299 code.setLetExprStackPos(prevLetExprStart);
1300 }
1301 } finally {
1302 stackBeforeSwitchExpression = prevStackBeforeSwitchExpression;
1303 switchResult = prevSwitchResult;
1304 code.endScopes(limit);
1305 }
1306 }
1307 //where:
1308 private boolean hasTry(JCSwitchExpression tree) {
1309 boolean[] hasTry = new boolean[1];
1310 new TreeScanner() {
1311 @Override
1312 public void visitTry(JCTry tree) {
1313 hasTry[0] = true;
1314 }
1315
1316 @Override
1317 public void visitClassDef(JCClassDecl tree) {
1318 }
1319
1320 @Override
1321 public void visitLambda(JCLambda tree) {
1322 }
1323 }.scan(tree);
1324 return hasTry[0];
1325 }
1326
1327 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases,
1328 boolean patternSwitch) {
1329 int limit = code.nextreg;
1330 Assert.check(!selector.type.hasTag(CLASS));
1331 int switchStart = patternSwitch ? code.entryPoint() : -1;
1332 int startpcCrt = genCrt ? code.curCP() : 0;
1333 Assert.check(code.isStatementStart());
1334 Item sel = genExpr(selector, syms.intType);
1335 if (cases.isEmpty()) {
1336 // We are seeing: switch <sel> {}
1337 sel.load().drop();
1338 if (genCrt)
1339 code.crt.put(TreeInfo.skipParens(selector),
1340 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1341 } else {
1342 // We are seeing a nonempty switch.
1343 sel.load();
1344 if (genCrt)
1345 code.crt.put(TreeInfo.skipParens(selector),
1346 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1347 Env<GenContext> switchEnv = env.dup(swtch, new GenContext());
1348 switchEnv.info.isSwitch = true;
1349
1350 // Compute number of labels and minimum and maximum label values.
1351 // For each case, store its label in an array.
1352 int lo = Integer.MAX_VALUE; // minimum label.
1353 int hi = Integer.MIN_VALUE; // maximum label.
1354 int nlabels = 0; // number of labels.
1355
1356 int[] labels = new int[cases.length()]; // the label array.
1357 int defaultIndex = -1; // the index of the default clause.
1358
1359 List<JCCase> l = cases;
1360 for (int i = 0; i < labels.length; i++) {
1361 if (l.head.labels.head instanceof JCConstantCaseLabel constLabel) {
1362 Assert.check(l.head.labels.size() == 1);
1363 int val = ((Number) constLabel.expr.type.constValue()).intValue();
1364 labels[i] = val;
1365 if (val < lo) lo = val;
1366 if (hi < val) hi = val;
1367 nlabels++;
1368 } else {
1369 Assert.check(defaultIndex == -1);
1370 defaultIndex = i;
1371 }
1372 l = l.tail;
1373 }
1374
1375 // Determine whether to issue a tableswitch or a lookupswitch
1376 // instruction.
1377 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1378 long table_time_cost = 3; // comparisons
1379 long lookup_space_cost = 3 + 2 * (long) nlabels;
1380 long lookup_time_cost = nlabels;
1381 int opcode =
1382 nlabels > 0 &&
1383 table_space_cost + 3 * table_time_cost <=
1384 lookup_space_cost + 3 * lookup_time_cost
1385 ?
1386 tableswitch : lookupswitch;
1387
1388 int startpc = code.curCP(); // the position of the selector operation
1389 code.emitop0(opcode);
1390 code.align(4);
1391 int tableBase = code.curCP(); // the start of the jump table
1392 int[] offsets = null; // a table of offsets for a lookupswitch
1393 code.emit4(-1); // leave space for default offset
1394 if (opcode == tableswitch) {
1395 code.emit4(lo); // minimum label
1396 code.emit4(hi); // maximum label
1397 for (long i = lo; i <= hi; i++) { // leave space for jump table
1398 code.emit4(-1);
1399 }
1400 } else {
1401 code.emit4(nlabels); // number of labels
1402 for (int i = 0; i < nlabels; i++) {
1403 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1404 }
1405 offsets = new int[labels.length];
1406 }
1407 Code.State stateSwitch = code.state.dup();
1408 code.markDead();
1409
1410 // For each case do:
1411 l = cases;
1412 for (int i = 0; i < labels.length; i++) {
1413 JCCase c = l.head;
1414 l = l.tail;
1415
1416 int pc = code.entryPoint(stateSwitch);
1417 // Insert offset directly into code or else into the
1418 // offsets table.
1419 if (i != defaultIndex) {
1420 if (opcode == tableswitch) {
1421 code.put4(
1422 tableBase + 4 * (labels[i] - lo + 3),
1423 pc - startpc);
1424 } else {
1425 offsets[i] = pc - startpc;
1426 }
1427 } else {
1428 code.put4(tableBase, pc - startpc);
1429 }
1430
1431 // Generate code for the statements in this case.
1432 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1433 }
1434
1435 if (switchEnv.info.cont != null) {
1436 Assert.check(patternSwitch);
1437 code.resolve(switchEnv.info.cont, switchStart);
1438 }
1439
1440 // Resolve all breaks.
1441 Chain exit = switchEnv.info.exit;
1442 if (exit != null) {
1443 code.resolve(exit);
1444 exit.state.defined.excludeFrom(limit);
1445 }
1446
1447 // If we have not set the default offset, we do so now.
1448 if (code.get4(tableBase) == -1) {
1449 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1450 }
1451
1452 if (opcode == tableswitch) {
1453 // Let any unfilled slots point to the default case.
1454 int defaultOffset = code.get4(tableBase);
1455 for (long i = lo; i <= hi; i++) {
1456 int t = (int)(tableBase + 4 * (i - lo + 3));
1457 if (code.get4(t) == -1)
1458 code.put4(t, defaultOffset);
1459 }
1460 } else {
1461 // Sort non-default offsets and copy into lookup table.
1462 if (defaultIndex >= 0)
1463 for (int i = defaultIndex; i < labels.length - 1; i++) {
1464 labels[i] = labels[i+1];
1465 offsets[i] = offsets[i+1];
1466 }
1467 if (nlabels > 0)
1468 qsort2(labels, offsets, 0, nlabels - 1);
1469 for (int i = 0; i < nlabels; i++) {
1470 int caseidx = tableBase + 8 * (i + 1);
1471 code.put4(caseidx, labels[i]);
1472 code.put4(caseidx + 4, offsets[i]);
1473 }
1474 }
1475 }
1476 code.endScopes(limit);
1477 }
1478 //where
1479 /** Sort (int) arrays of keys and values
1480 */
1481 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1482 int i = lo;
1483 int j = hi;
1484 int pivot = keys[(i+j)/2];
1485 do {
1486 while (keys[i] < pivot) i++;
1487 while (pivot < keys[j]) j--;
1488 if (i <= j) {
1489 int temp1 = keys[i];
1490 keys[i] = keys[j];
1491 keys[j] = temp1;
1492 int temp2 = values[i];
1493 values[i] = values[j];
1494 values[j] = temp2;
1495 i++;
1496 j--;
1497 }
1498 } while (i <= j);
1499 if (lo < j) qsort2(keys, values, lo, j);
1500 if (i < hi) qsort2(keys, values, i, hi);
1501 }
1502
1503 public void visitSynchronized(JCSynchronized tree) {
1504 int limit = code.nextreg;
1505 // Generate code to evaluate lock and save in temporary variable.
1506 final LocalItem lockVar = makeTemp(syms.objectType);
1507 Assert.check(code.isStatementStart());
1508 genExpr(tree.lock, tree.lock.type).load().duplicate();
1509 lockVar.store();
1510
1511 // Generate code to enter monitor.
1512 code.emitop0(monitorenter);
1513 code.state.lock(lockVar.reg);
1514
1515 // Generate code for a try statement with given body, no catch clauses
1516 // in a new environment with the "exit-monitor" operation as finalizer.
1517 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1518 syncEnv.info.finalize = new GenFinalizer() {
1519 void gen() {
1520 genLast();
1521 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1522 syncEnv.info.gaps.append(code.curCP());
1523 }
1524 void genLast() {
1525 if (code.isAlive()) {
1526 lockVar.load();
1527 code.emitop0(monitorexit);
1528 code.state.unlock(lockVar.reg);
1529 }
1530 }
1531 };
1532 syncEnv.info.gaps = new ListBuffer<>();
1533 genTry(tree.body, List.nil(), syncEnv);
1534 code.endScopes(limit);
1535 }
1536
1537 public void visitTry(final JCTry tree) {
1538 // Generate code for a try statement with given body and catch clauses,
1539 // in a new environment which calls the finally block if there is one.
1540 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1541 final Env<GenContext> oldEnv = env;
1542 tryEnv.info.finalize = new GenFinalizer() {
1543 void gen() {
1544 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1545 tryEnv.info.gaps.append(code.curCP());
1546 genLast();
1547 }
1548 void genLast() {
1549 if (tree.finalizer != null)
1550 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1551 }
1552 boolean hasFinalizer() {
1553 return tree.finalizer != null;
1554 }
1555
1556 @Override
1557 void afterBody() {
1558 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1559 //for body-only finally, remove the GenFinalizer after try body
1560 //so that the finally is not generated to catch bodies:
1561 tryEnv.info.finalize = null;
1562 }
1563 }
1564
1565 };
1566 tryEnv.info.gaps = new ListBuffer<>();
1567 genTry(tree.body, tree.catchers, tryEnv);
1568 }
1569 //where
1570 /** Generate code for a try or synchronized statement
1571 * @param body The body of the try or synchronized statement.
1572 * @param catchers The list of catch clauses.
1573 * @param env The current environment of the body.
1574 */
1575 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1576 int limit = code.nextreg;
1577 int startpc = code.curCP();
1578 Code.State stateTry = code.state.dup();
1579 genStat(body, env, CRT_BLOCK);
1580 int endpc = code.curCP();
1581 List<Integer> gaps = env.info.gaps.toList();
1582 code.statBegin(TreeInfo.endPos(body));
1583 genFinalizer(env);
1584 code.statBegin(TreeInfo.endPos(env.tree));
1585 Chain exitChain;
1586 boolean actualTry = env.tree.hasTag(TRY);
1587 if (startpc == endpc && actualTry) {
1588 exitChain = code.branch(dontgoto);
1589 } else {
1590 exitChain = code.branch(goto_);
1591 }
1592 endFinalizerGap(env);
1593 env.info.finalize.afterBody();
1594 boolean hasFinalizer =
1595 env.info.finalize != null &&
1596 env.info.finalize.hasFinalizer();
1597 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1598 // start off with exception on stack
1599 code.entryPoint(stateTry, l.head.param.sym.type);
1600 genCatch(l.head, env, startpc, endpc, gaps);
1601 genFinalizer(env);
1602 if (hasFinalizer || l.tail.nonEmpty()) {
1603 code.statBegin(TreeInfo.endPos(env.tree));
1604 exitChain = Code.mergeChains(exitChain,
1605 code.branch(goto_));
1606 }
1607 endFinalizerGap(env);
1608 }
1609 if (hasFinalizer && (startpc != endpc || !actualTry)) {
1610 // Create a new register segment to avoid allocating
1611 // the same variables in finalizers and other statements.
1612 code.newRegSegment();
1613
1614 // Add a catch-all clause.
1615
1616 // start off with exception on stack
1617 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1618
1619 // Register all exception ranges for catch all clause.
1620 // The range of the catch all clause is from the beginning
1621 // of the try or synchronized block until the present
1622 // code pointer excluding all gaps in the current
1623 // environment's GenContext.
1624 int startseg = startpc;
1625 while (env.info.gaps.nonEmpty()) {
1626 int endseg = env.info.gaps.next().intValue();
1627 registerCatch(body.pos(), startseg, endseg,
1628 catchallpc, 0);
1629 startseg = env.info.gaps.next().intValue();
1630 }
1631 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1632 code.markStatBegin();
1633
1634 Item excVar = makeTemp(syms.throwableType);
1635 excVar.store();
1636 genFinalizer(env);
1637 code.resolvePending();
1638 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1639 code.markStatBegin();
1640
1641 excVar.load();
1642 registerCatch(body.pos(), startseg,
1643 env.info.gaps.next().intValue(),
1644 catchallpc, 0);
1645 code.emitop0(athrow);
1646 code.markDead();
1647
1648 // If there are jsr's to this finalizer, ...
1649 if (env.info.cont != null) {
1650 // Resolve all jsr's.
1651 code.resolve(env.info.cont);
1652
1653 // Mark statement line number
1654 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1655 code.markStatBegin();
1656
1657 // Save return address.
1658 LocalItem retVar = makeTemp(syms.throwableType);
1659 retVar.store();
1660
1661 // Generate finalizer code.
1662 env.info.finalize.genLast();
1663
1664 // Return.
1665 code.emitop1w(ret, retVar.reg);
1666 code.markDead();
1667 }
1668 }
1669 // Resolve all breaks.
1670 code.resolve(exitChain);
1671
1672 code.endScopes(limit);
1673 }
1674
1675 /** Generate code for a catch clause.
1676 * @param tree The catch clause.
1677 * @param env The environment current in the enclosing try.
1678 * @param startpc Start pc of try-block.
1679 * @param endpc End pc of try-block.
1680 */
1681 void genCatch(JCCatch tree,
1682 Env<GenContext> env,
1683 int startpc, int endpc,
1684 List<Integer> gaps) {
1685 if (startpc != endpc) {
1686 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs
1687 = catchTypesWithAnnotations(tree);
1688 while (gaps.nonEmpty()) {
1689 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1690 JCExpression subCatch = subCatch1.snd;
1691 int catchType = makeRef(tree.pos(), subCatch.type);
1692 int end = gaps.head.intValue();
1693 registerCatch(tree.pos(),
1694 startpc, end, code.curCP(),
1695 catchType);
1696 for (Attribute.TypeCompound tc : subCatch1.fst) {
1697 tc.position.setCatchInfo(catchType, startpc);
1698 }
1699 }
1700 gaps = gaps.tail;
1701 startpc = gaps.head.intValue();
1702 gaps = gaps.tail;
1703 }
1704 if (startpc < endpc) {
1705 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1706 JCExpression subCatch = subCatch1.snd;
1707 int catchType = makeRef(tree.pos(), subCatch.type);
1708 registerCatch(tree.pos(),
1709 startpc, endpc, code.curCP(),
1710 catchType);
1711 for (Attribute.TypeCompound tc : subCatch1.fst) {
1712 tc.position.setCatchInfo(catchType, startpc);
1713 }
1714 }
1715 }
1716 VarSymbol exparam = tree.param.sym;
1717 code.statBegin(tree.pos);
1718 code.markStatBegin();
1719 int limit = code.nextreg;
1720 code.newLocal(exparam);
1721 items.makeLocalItem(exparam).store();
1722 code.statBegin(TreeInfo.firstStatPos(tree.body));
1723 genStat(tree.body, env, CRT_BLOCK);
1724 code.endScopes(limit);
1725 code.statBegin(TreeInfo.endPos(tree.body));
1726 }
1727 }
1728 // where
1729 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) {
1730 return TreeInfo.isMultiCatch(tree) ?
1731 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) :
1732 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype));
1733 }
1734 // where
1735 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) {
1736 List<JCExpression> alts = tree.alternatives;
1737 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head));
1738 alts = alts.tail;
1739
1740 while(alts != null && alts.head != null) {
1741 JCExpression alt = alts.head;
1742 if (alt instanceof JCAnnotatedType annotatedType) {
1743 res = res.prepend(new Pair<>(annotate.fromAnnotations(annotatedType.annotations), alt));
1744 } else {
1745 res = res.prepend(new Pair<>(List.nil(), alt));
1746 }
1747 alts = alts.tail;
1748 }
1749 return res.reverse();
1750 }
1751
1752 /** Register a catch clause in the "Exceptions" code-attribute.
1753 */
1754 void registerCatch(DiagnosticPosition pos,
1755 int startpc, int endpc,
1756 int handler_pc, int catch_type) {
1757 char startpc1 = (char)startpc;
1758 char endpc1 = (char)endpc;
1759 char handler_pc1 = (char)handler_pc;
1760 if (startpc1 == startpc &&
1761 endpc1 == endpc &&
1762 handler_pc1 == handler_pc) {
1763 code.addCatch(startpc1, endpc1, handler_pc1,
1764 (char)catch_type);
1765 } else {
1766 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1767 nerrs++;
1768 }
1769 }
1770
1771 public void visitIf(JCIf tree) {
1772 int limit = code.nextreg;
1773 Chain thenExit = null;
1774 Assert.check(code.isStatementStart());
1775 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1776 CRT_FLOW_CONTROLLER);
1777 Chain elseChain = c.jumpFalse();
1778 Assert.check(code.isStatementStart());
1779 if (!c.isFalse()) {
1780 code.resolve(c.trueJumps);
1781 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1782 thenExit = code.branch(goto_);
1783 }
1784 if (elseChain != null) {
1785 code.resolve(elseChain);
1786 if (tree.elsepart != null) {
1787 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1788 }
1789 }
1790 code.resolve(thenExit);
1791 code.endScopes(limit);
1792 Assert.check(code.isStatementStart());
1793 }
1794
1795 public void visitExec(JCExpressionStatement tree) {
1796 // Optimize x++ to ++x and x-- to --x.
1797 JCExpression e = tree.expr;
1798 switch (e.getTag()) {
1799 case POSTINC:
1800 ((JCUnary) e).setTag(PREINC);
1801 break;
1802 case POSTDEC:
1803 ((JCUnary) e).setTag(PREDEC);
1804 break;
1805 }
1806 Assert.check(code.isStatementStart());
1807 genExpr(tree.expr, tree.expr.type).drop();
1808 Assert.check(code.isStatementStart());
1809 }
1810
1811 public void visitBreak(JCBreak tree) {
1812 Assert.check(code.isStatementStart());
1813 final Env<GenContext> targetEnv = unwindBreak(tree.target);
1814 targetEnv.info.addExit(code.branch(goto_));
1815 endFinalizerGaps(env, targetEnv);
1816 }
1817
1818 public void visitYield(JCYield tree) {
1819 Assert.check(code.isStatementStart());
1820 final Env<GenContext> targetEnv;
1821 if (inCondSwitchExpression) {
1822 CondItem value = genCond(tree.value, CRT_FLOW_TARGET);
1823 Chain falseJumps = value.jumpFalse();
1824
1825 code.resolve(value.trueJumps);
1826 Env<GenContext> localEnv = unwindBreak(tree.target);
1827 reloadStackBeforeSwitchExpr();
1828 Chain trueJumps = code.branch(goto_);
1829
1830 endFinalizerGaps(env, localEnv);
1831
1832 code.resolve(falseJumps);
1833 targetEnv = unwindBreak(tree.target);
1834 reloadStackBeforeSwitchExpr();
1835 falseJumps = code.branch(goto_);
1836
1837 if (switchExpressionTrueChain == null) {
1838 switchExpressionTrueChain = trueJumps;
1839 } else {
1840 switchExpressionTrueChain =
1841 Code.mergeChains(switchExpressionTrueChain, trueJumps);
1842 }
1843 if (switchExpressionFalseChain == null) {
1844 switchExpressionFalseChain = falseJumps;
1845 } else {
1846 switchExpressionFalseChain =
1847 Code.mergeChains(switchExpressionFalseChain, falseJumps);
1848 }
1849 } else {
1850 genExpr(tree.value, pt).load();
1851 if (switchResult != null)
1852 switchResult.store();
1853
1854 targetEnv = unwindBreak(tree.target);
1855
1856 if (code.isAlive()) {
1857 reloadStackBeforeSwitchExpr();
1858 if (switchResult != null)
1859 switchResult.load();
1860
1861 code.state.forceStackTop(tree.target.type);
1862 targetEnv.info.addExit(code.branch(goto_));
1863 code.markDead();
1864 }
1865 }
1866 endFinalizerGaps(env, targetEnv);
1867 }
1868 //where:
1869 /** As side-effect, might mark code as dead disabling any further emission.
1870 */
1871 private Env<GenContext> unwindBreak(JCTree target) {
1872 int tmpPos = code.pendingStatPos;
1873 Env<GenContext> targetEnv = unwind(target, env);
1874 code.pendingStatPos = tmpPos;
1875 return targetEnv;
1876 }
1877
1878 private void reloadStackBeforeSwitchExpr() {
1879 for (LocalItem li : stackBeforeSwitchExpression)
1880 li.load();
1881 }
1882
1883 public void visitContinue(JCContinue tree) {
1884 int tmpPos = code.pendingStatPos;
1885 Env<GenContext> targetEnv = unwind(tree.target, env);
1886 code.pendingStatPos = tmpPos;
1887 Assert.check(code.isStatementStart());
1888 targetEnv.info.addCont(code.branch(goto_));
1889 endFinalizerGaps(env, targetEnv);
1890 }
1891
1892 public void visitReturn(JCReturn tree) {
1893 int limit = code.nextreg;
1894 final Env<GenContext> targetEnv;
1895
1896 /* Save and then restore the location of the return in case a finally
1897 * is expanded (with unwind()) in the middle of our bytecodes.
1898 */
1899 int tmpPos = code.pendingStatPos;
1900 if (tree.expr != null) {
1901 Assert.check(code.isStatementStart());
1902 Item r = genExpr(tree.expr, pt).load();
1903 if (hasFinally(env.enclMethod, env)) {
1904 r = makeTemp(pt);
1905 r.store();
1906 }
1907 targetEnv = unwind(env.enclMethod, env);
1908 code.pendingStatPos = tmpPos;
1909 r.load();
1910 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
1911 } else {
1912 targetEnv = unwind(env.enclMethod, env);
1913 code.pendingStatPos = tmpPos;
1914 code.emitop0(return_);
1915 }
1916 endFinalizerGaps(env, targetEnv);
1917 code.endScopes(limit);
1918 }
1919
1920 public void visitThrow(JCThrow tree) {
1921 Assert.check(code.isStatementStart());
1922 genExpr(tree.expr, tree.expr.type).load();
1923 code.emitop0(athrow);
1924 Assert.check(code.isStatementStart());
1925 }
1926
1927 /* ************************************************************************
1928 * Visitor methods for expressions
1929 *************************************************************************/
1930
1931 public void visitApply(JCMethodInvocation tree) {
1932 setTypeAnnotationPositions(tree.pos);
1933 // Generate code for method.
1934 Item m = genExpr(tree.meth, methodType);
1935 // Generate code for all arguments, where the expected types are
1936 // the parameters of the method's external type (that is, any implicit
1937 // outer instance of a super(...) call appears as first parameter).
1938 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
1939 genArgs(tree.args,
1940 msym.externalType(types).getParameterTypes());
1941 if (!msym.isDynamic()) {
1942 code.statBegin(tree.pos);
1943 }
1944 result = m.invoke();
1945 }
1946
1947 public void visitConditional(JCConditional tree) {
1948 Chain thenExit = null;
1949 code.statBegin(tree.cond.pos);
1950 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
1951 Chain elseChain = c.jumpFalse();
1952 if (!c.isFalse()) {
1953 code.resolve(c.trueJumps);
1954 int startpc = genCrt ? code.curCP() : 0;
1955 code.statBegin(tree.truepart.pos);
1956 genExpr(tree.truepart, pt).load();
1957 code.state.forceStackTop(tree.type);
1958 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
1959 startpc, code.curCP());
1960 thenExit = code.branch(goto_);
1961 }
1962 if (elseChain != null) {
1963 code.resolve(elseChain);
1964 int startpc = genCrt ? code.curCP() : 0;
1965 code.statBegin(tree.falsepart.pos);
1966 genExpr(tree.falsepart, pt).load();
1967 code.state.forceStackTop(tree.type);
1968 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
1969 startpc, code.curCP());
1970 }
1971 code.resolve(thenExit);
1972 result = items.makeStackItem(pt);
1973 }
1974
1975 private void setTypeAnnotationPositions(int treePos) {
1976 MethodSymbol meth = code.meth;
1977 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR
1978 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT;
1979
1980 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
1981 if (ta.hasUnknownPosition())
1982 ta.tryFixPosition();
1983
1984 if (ta.position.matchesPos(treePos))
1985 ta.position.updatePosOffset(code.cp);
1986 }
1987
1988 if (!initOrClinit)
1989 return;
1990
1991 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
1992 if (ta.hasUnknownPosition())
1993 ta.tryFixPosition();
1994
1995 if (ta.position.matchesPos(treePos))
1996 ta.position.updatePosOffset(code.cp);
1997 }
1998
1999 ClassSymbol clazz = meth.enclClass();
2000 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
2001 if (!s.getKind().isField())
2002 continue;
2003
2004 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
2005 if (ta.hasUnknownPosition())
2006 ta.tryFixPosition();
2007
2008 if (ta.position.matchesPos(treePos))
2009 ta.position.updatePosOffset(code.cp);
2010 }
2011 }
2012 }
2013
2014 public void visitNewClass(JCNewClass tree) {
2015 // Enclosing instances or anonymous classes should have been eliminated
2016 // by now.
2017 Assert.check(tree.encl == null && tree.def == null);
2018 setTypeAnnotationPositions(tree.pos);
2019
2020 code.emitop2(new_, checkDimension(tree.pos(), tree.type), PoolWriter::putClass);
2021 code.emitop0(dup);
2022
2023 // Generate code for all arguments, where the expected types are
2024 // the parameters of the constructor's external type (that is,
2025 // any implicit outer instance appears as first parameter).
2026 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
2027
2028 items.makeMemberItem(tree.constructor, true).invoke();
2029
2030 result = items.makeStackItem(tree.type);
2031 }
2032
2033 public void visitNewArray(JCNewArray tree) {
2034 setTypeAnnotationPositions(tree.pos);
2035
2036 if (tree.elems != null) {
2037 Type elemtype = types.elemtype(tree.type);
2038 loadIntConst(tree.elems.length());
2039 Item arr = makeNewArray(tree.pos(), tree.type, 1);
2040 int i = 0;
2041 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
2042 arr.duplicate();
2043 loadIntConst(i);
2044 i++;
2045 genExpr(l.head, elemtype).load();
2046 items.makeIndexedItem(elemtype).store();
2047 }
2048 result = arr;
2049 } else {
2050 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
2051 genExpr(l.head, syms.intType).load();
2052 }
2053 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
2054 }
2055 }
2056 //where
2057 /** Generate code to create an array with given element type and number
2058 * of dimensions.
2059 */
2060 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
2061 Type elemtype = types.elemtype(type);
2062 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
2063 log.error(pos, Errors.LimitDimensions);
2064 nerrs++;
2065 }
2066 int elemcode = Code.arraycode(elemtype);
2067 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
2068 code.emitAnewarray(makeRef(pos, elemtype, elemtype.isPrimitiveClass()), type);
2069 } else if (elemcode == 1) {
2070 code.emitMultianewarray(ndims, makeRef(pos, type), type);
2071 } else {
2072 code.emitNewarray(elemcode, type);
2073 }
2074 return items.makeStackItem(type);
2075 }
2076
2077 public void visitParens(JCParens tree) {
2078 result = genExpr(tree.expr, tree.expr.type);
2079 }
2080
2081 public void visitAssign(JCAssign tree) {
2082 Item l = genExpr(tree.lhs, tree.lhs.type);
2083 genExpr(tree.rhs, tree.lhs.type).load();
2084 if (tree.rhs.type.hasTag(BOT)) {
2085 /* This is just a case of widening reference conversion that per 5.1.5 simply calls
2086 for "regarding a reference as having some other type in a manner that can be proved
2087 correct at compile time."
2088 */
2089 code.state.forceStackTop(tree.lhs.type);
2090 }
2091 result = items.makeAssignItem(l);
2092 }
2093
2094 public void visitAssignop(JCAssignOp tree) {
2095 OperatorSymbol operator = tree.operator;
2096 Item l;
2097 if (operator.opcode == string_add) {
2098 l = concat.makeConcat(tree);
2099 } else {
2100 // Generate code for first expression
2101 l = genExpr(tree.lhs, tree.lhs.type);
2102
2103 // If we have an increment of -32768 to +32767 of a local
2104 // int variable we can use an incr instruction instead of
2105 // proceeding further.
2106 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
2107 l instanceof LocalItem localItem &&
2108 tree.lhs.type.getTag().isSubRangeOf(INT) &&
2109 tree.rhs.type.getTag().isSubRangeOf(INT) &&
2110 tree.rhs.type.constValue() != null) {
2111 int ival = ((Number) tree.rhs.type.constValue()).intValue();
2112 if (tree.hasTag(MINUS_ASG)) ival = -ival;
2113 localItem.incr(ival);
2114 result = l;
2115 return;
2116 }
2117 // Otherwise, duplicate expression, load one copy
2118 // and complete binary operation.
2119 l.duplicate();
2120 l.coerce(operator.type.getParameterTypes().head).load();
2121 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
2122 }
2123 result = items.makeAssignItem(l);
2124 }
2125
2126 public void visitUnary(JCUnary tree) {
2127 OperatorSymbol operator = tree.operator;
2128 if (tree.hasTag(NOT)) {
2129 CondItem od = genCond(tree.arg, false);
2130 result = od.negate();
2131 } else {
2132 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
2133 switch (tree.getTag()) {
2134 case POS:
2135 result = od.load();
2136 break;
2137 case NEG:
2138 result = od.load();
2139 code.emitop0(operator.opcode);
2140 break;
2141 case COMPL:
2142 result = od.load();
2143 emitMinusOne(od.typecode);
2144 code.emitop0(operator.opcode);
2145 break;
2146 case PREINC: case PREDEC:
2147 od.duplicate();
2148 if (od instanceof LocalItem localItem &&
2149 (operator.opcode == iadd || operator.opcode == isub)) {
2150 localItem.incr(tree.hasTag(PREINC) ? 1 : -1);
2151 result = od;
2152 } else {
2153 od.load();
2154 code.emitop0(one(od.typecode));
2155 code.emitop0(operator.opcode);
2156 // Perform narrowing primitive conversion if byte,
2157 // char, or short. Fix for 4304655.
2158 if (od.typecode != INTcode &&
2159 Code.truncate(od.typecode) == INTcode)
2160 code.emitop0(int2byte + od.typecode - BYTEcode);
2161 result = items.makeAssignItem(od);
2162 }
2163 break;
2164 case POSTINC: case POSTDEC:
2165 od.duplicate();
2166 if (od instanceof LocalItem localItem &&
2167 (operator.opcode == iadd || operator.opcode == isub)) {
2168 Item res = od.load();
2169 localItem.incr(tree.hasTag(POSTINC) ? 1 : -1);
2170 result = res;
2171 } else {
2172 Item res = od.load();
2173 od.stash(od.typecode);
2174 code.emitop0(one(od.typecode));
2175 code.emitop0(operator.opcode);
2176 // Perform narrowing primitive conversion if byte,
2177 // char, or short. Fix for 4304655.
2178 if (od.typecode != INTcode &&
2179 Code.truncate(od.typecode) == INTcode)
2180 code.emitop0(int2byte + od.typecode - BYTEcode);
2181 od.store();
2182 result = res;
2183 }
2184 break;
2185 case NULLCHK:
2186 result = od.load();
2187 code.emitop0(dup);
2188 genNullCheck(tree);
2189 break;
2190 default:
2191 Assert.error();
2192 }
2193 }
2194 }
2195
2196 /** Generate a null check from the object value at stack top. */
2197 private void genNullCheck(JCTree tree) {
2198 code.statBegin(tree.pos);
2199 callMethod(tree.pos(), syms.objectsType, names.requireNonNull,
2200 List.of(syms.objectType), true);
2201 code.emitop0(pop);
2202 }
2203
2204 public void visitBinary(JCBinary tree) {
2205 OperatorSymbol operator = tree.operator;
2206 if (operator.opcode == string_add) {
2207 result = concat.makeConcat(tree);
2208 } else if (tree.hasTag(AND)) {
2209 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2210 if (!lcond.isFalse()) {
2211 Chain falseJumps = lcond.jumpFalse();
2212 code.resolve(lcond.trueJumps);
2213 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2214 result = items.
2215 makeCondItem(rcond.opcode,
2216 rcond.trueJumps,
2217 Code.mergeChains(falseJumps,
2218 rcond.falseJumps));
2219 } else {
2220 result = lcond;
2221 }
2222 } else if (tree.hasTag(OR)) {
2223 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2224 if (!lcond.isTrue()) {
2225 Chain trueJumps = lcond.jumpTrue();
2226 code.resolve(lcond.falseJumps);
2227 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2228 result = items.
2229 makeCondItem(rcond.opcode,
2230 Code.mergeChains(trueJumps, rcond.trueJumps),
2231 rcond.falseJumps);
2232 } else {
2233 result = lcond;
2234 }
2235 } else {
2236 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
2237 od.load();
2238 result = completeBinop(tree.lhs, tree.rhs, operator);
2239 }
2240 }
2241
2242
2243 /** Complete generating code for operation, with left operand
2244 * already on stack.
2245 * @param lhs The tree representing the left operand.
2246 * @param rhs The tree representing the right operand.
2247 * @param operator The operator symbol.
2248 */
2249 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2250 MethodType optype = (MethodType)operator.type;
2251 int opcode = operator.opcode;
2252 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2253 rhs.type.constValue() instanceof Number number &&
2254 number.intValue() == 0) {
2255 opcode = opcode + (ifeq - if_icmpeq);
2256 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2257 TreeInfo.isNull(rhs)) {
2258 opcode = opcode + (if_acmp_null - if_acmpeq);
2259 } else {
2260 // The expected type of the right operand is
2261 // the second parameter type of the operator, except for
2262 // shifts with long shiftcount, where we convert the opcode
2263 // to a short shift and the expected type to int.
2264 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2265 if (opcode >= ishll && opcode <= lushrl) {
2266 opcode = opcode + (ishl - ishll);
2267 rtype = syms.intType;
2268 }
2269 // Generate code for right operand and load.
2270 genExpr(rhs, rtype).load();
2271 // If there are two consecutive opcode instructions,
2272 // emit the first now.
2273 if (opcode >= (1 << preShift)) {
2274 code.emitop0(opcode >> preShift);
2275 opcode = opcode & 0xFF;
2276 }
2277 }
2278 if (opcode >= ifeq && opcode <= if_acmpne ||
2279 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2280 return items.makeCondItem(opcode);
2281 } else {
2282 code.emitop0(opcode);
2283 return items.makeStackItem(optype.restype);
2284 }
2285 }
2286
2287 public void visitTypeCast(JCTypeCast tree) {
2288 result = genExpr(tree.expr, tree.clazz.type).load();
2289 setTypeAnnotationPositions(tree.pos);
2290 // Additional code is only needed if we cast to a reference type
2291 // which is not statically a supertype of the expression's type.
2292 // For basic types, the coerce(...) in genExpr(...) will do
2293 // the conversion.
2294 // primitive reference conversion is a nop when we bifurcate the primitive class, as the VM sees a subtyping relationship.
2295 if (!tree.clazz.type.isPrimitive() &&
2296 !types.isSameType(tree.expr.type, tree.clazz.type) &&
2297 (!tree.clazz.type.isReferenceProjection() || !types.isSameType(tree.clazz.type.valueProjection(), tree.expr.type) || true) &&
2298 !types.isSubtype(tree.expr.type, tree.clazz.type)) {
2299 checkDimension(tree.pos(), tree.clazz.type);
2300 if (tree.clazz.type.isPrimitiveClass()) {
2301 code.emitop2(checkcast, new ConstantPoolQType(tree.clazz.type, types), PoolWriter::putClass);
2302 } else {
2303 code.emitop2(checkcast, tree.clazz.type, PoolWriter::putClass);
2304 }
2305
2306 }
2307 }
2308
2309 public void visitWildcard(JCWildcard tree) {
2310 throw new AssertionError(this.getClass().getName());
2311 }
2312
2313 public void visitTypeTest(JCInstanceOf tree) {
2314 genExpr(tree.expr, tree.expr.type).load();
2315 setTypeAnnotationPositions(tree.pos);
2316 code.emitop2(instanceof_, makeRef(tree.pos(), tree.pattern.type));
2317 result = items.makeStackItem(syms.booleanType);
2318 }
2319
2320 public void visitIndexed(JCArrayAccess tree) {
2321 genExpr(tree.indexed, tree.indexed.type).load();
2322 genExpr(tree.index, syms.intType).load();
2323 result = items.makeIndexedItem(tree.type);
2324 }
2325
2326 public void visitIdent(JCIdent tree) {
2327 Symbol sym = tree.sym;
2328 if (tree.name == names._this || tree.name == names._super) {
2329 Item res = tree.name == names._this
2330 ? items.makeThisItem()
2331 : items.makeSuperItem();
2332 if (sym.kind == MTH) {
2333 // Generate code to address the constructor.
2334 res.load();
2335 res = items.makeMemberItem(sym, true);
2336 }
2337 result = res;
2338 } else if (isInvokeDynamic(sym) || isConstantDynamic(sym)) {
2339 if (isConstantDynamic(sym)) {
2340 setTypeAnnotationPositions(tree.pos);
2341 }
2342 result = items.makeDynamicItem(sym);
2343 } else if (sym.kind == VAR && (sym.owner.kind == MTH || sym.owner.kind == VAR)) {
2344 result = items.makeLocalItem((VarSymbol)sym);
2345 } else if ((sym.flags() & STATIC) != 0) {
2346 if (!isAccessSuper(env.enclMethod))
2347 sym = binaryQualifier(sym, env.enclClass.type);
2348 result = items.makeStaticItem(sym);
2349 } else {
2350 items.makeThisItem().load();
2351 sym = binaryQualifier(sym, env.enclClass.type);
2352 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym));
2353 }
2354 }
2355
2356 //where
2357 private boolean nonVirtualForPrivateAccess(Symbol sym) {
2358 boolean useVirtual = target.hasVirtualPrivateInvoke() &&
2359 !disableVirtualizedPrivateInvoke;
2360 return !useVirtual && ((sym.flags() & PRIVATE) != 0);
2361 }
2362
2363 public void visitSelect(JCFieldAccess tree) {
2364 Symbol sym = tree.sym;
2365
2366 if (tree.name == names._class) {
2367 code.emitLdc((LoadableConstant) tree.selected.type, makeRef(tree.pos(), tree.selected.type, tree.selected.type.isPrimitiveClass()));
2368 result = items.makeStackItem(pt);
2369 return;
2370 }
2371
2372 Symbol ssym = TreeInfo.symbol(tree.selected);
2373
2374 // Are we selecting via super?
2375 boolean selectSuper =
2376 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2377
2378 // Are we accessing a member of the superclass in an access method
2379 // resulting from a qualified super?
2380 boolean accessSuper = isAccessSuper(env.enclMethod);
2381
2382 Item base = (selectSuper)
2383 ? items.makeSuperItem()
2384 : genExpr(tree.selected, tree.selected.type);
2385
2386 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2387 // We are seeing a variable that is constant but its selecting
2388 // expression is not.
2389 if ((sym.flags() & STATIC) != 0) {
2390 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2391 base = base.load();
2392 base.drop();
2393 } else {
2394 base.load();
2395 genNullCheck(tree.selected);
2396 }
2397 result = items.
2398 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2399 } else {
2400 if (isInvokeDynamic(sym)) {
2401 result = items.makeDynamicItem(sym);
2402 return;
2403 } else {
2404 sym = binaryQualifier(sym, tree.selected.type);
2405 }
2406 if ((sym.flags() & STATIC) != 0) {
2407 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2408 base = base.load();
2409 base.drop();
2410 result = items.makeStaticItem(sym);
2411 } else {
2412 base.load();
2413 if (sym == syms.lengthVar) {
2414 code.emitop0(arraylength);
2415 result = items.makeStackItem(syms.intType);
2416 } else {
2417 result = items.
2418 makeMemberItem(sym,
2419 nonVirtualForPrivateAccess(sym) ||
2420 selectSuper || accessSuper);
2421 }
2422 }
2423 }
2424 }
2425
2426 public void visitDefaultValue(JCDefaultValue tree) {
2427 if (tree.type.isValueClass()) {
2428 code.emitop2(aconst_init, checkDimension(tree.pos(), tree.type), PoolWriter::putClass);
2429 } else if (tree.type.isReference()) {
2430 code.emitop0(aconst_null);
2431 } else {
2432 code.emitop0(zero(Code.typecode(tree.type)));
2433 }
2434 result = items.makeStackItem(tree.type);
2435 return;
2436 }
2437
2438 public boolean isInvokeDynamic(Symbol sym) {
2439 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
2440 }
2441
2442 public void visitLiteral(JCLiteral tree) {
2443 if (tree.type.hasTag(BOT)) {
2444 code.emitop0(aconst_null);
2445 result = items.makeStackItem(tree.type);
2446 }
2447 else
2448 result = items.makeImmediateItem(tree.type, tree.value);
2449 }
2450
2451 public void visitLetExpr(LetExpr tree) {
2452 code.resolvePending();
2453
2454 int limit = code.nextreg;
2455 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
2456 try {
2457 genStats(tree.defs, env);
2458 } finally {
2459 code.setLetExprStackPos(prevLetExprStart);
2460 }
2461 result = genExpr(tree.expr, tree.expr.type).load();
2462 code.endScopes(limit);
2463 }
2464
2465 private void generateReferencesToPrunedTree(ClassSymbol classSymbol) {
2466 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
2467 if (prunedInfo != null) {
2468 for (JCTree prunedTree: prunedInfo) {
2469 prunedTree.accept(classReferenceVisitor);
2470 }
2471 }
2472 }
2473
2474 /* ************************************************************************
2475 * main method
2476 *************************************************************************/
2477
2478 /** Generate code for a class definition.
2479 * @param env The attribution environment that belongs to the
2480 * outermost class containing this class definition.
2481 * We need this for resolving some additional symbols.
2482 * @param cdef The tree representing the class definition.
2483 * @return True if code is generated with no errors.
2484 */
2485 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2486 try {
2487 attrEnv = env;
2488 ClassSymbol c = cdef.sym;
2489 this.toplevel = env.toplevel;
2490 this.endPosTable = toplevel.endPositions;
2491 /* method normalizeDefs() can add references to external classes into the constant pool
2492 */
2493 cdef.defs = normalizeDefs(cdef.defs, c);
2494 cdef = transValues.translateTopLevelClass(cdef, make);
2495 generateReferencesToPrunedTree(c);
2496 Env<GenContext> localEnv = new Env<>(cdef, new GenContext());
2497 localEnv.toplevel = env.toplevel;
2498 localEnv.enclClass = cdef;
2499
2500 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2501 genDef(l.head, localEnv);
2502 }
2503 if (poolWriter.size() > PoolWriter.MAX_ENTRIES) {
2504 log.error(cdef.pos(), Errors.LimitPool);
2505 nerrs++;
2506 }
2507 if (nerrs != 0) {
2508 // if errors, discard code
2509 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2510 if (l.head.hasTag(METHODDEF))
2511 ((JCMethodDecl) l.head).sym.code = null;
2512 }
2513 }
2514 cdef.defs = List.nil(); // discard trees
2515 return nerrs == 0;
2516 } finally {
2517 // note: this method does NOT support recursion.
2518 attrEnv = null;
2519 this.env = null;
2520 toplevel = null;
2521 endPosTable = null;
2522 nerrs = 0;
2523 qualifiedSymbolCache.clear();
2524 }
2525 }
2526
2527 /* ************************************************************************
2528 * Auxiliary classes
2529 *************************************************************************/
2530
2531 /** An abstract class for finalizer generation.
2532 */
2533 abstract class GenFinalizer {
2534 /** Generate code to clean up when unwinding. */
2535 abstract void gen();
2536
2537 /** Generate code to clean up at last. */
2538 abstract void genLast();
2539
2540 /** Does this finalizer have some nontrivial cleanup to perform? */
2541 boolean hasFinalizer() { return true; }
2542
2543 /** Should be invoked after the try's body has been visited. */
2544 void afterBody() {}
2545 }
2546
2547 /** code generation contexts,
2548 * to be used as type parameter for environments.
2549 */
2550 static class GenContext {
2551
2552 /** A chain for all unresolved jumps that exit the current environment.
2553 */
2554 Chain exit = null;
2555
2556 /** A chain for all unresolved jumps that continue in the
2557 * current environment.
2558 */
2559 Chain cont = null;
2560
2561 /** A closure that generates the finalizer of the current environment.
2562 * Only set for Synchronized and Try contexts.
2563 */
2564 GenFinalizer finalize = null;
2565
2566 /** Is this a switch statement? If so, allocate registers
2567 * even when the variable declaration is unreachable.
2568 */
2569 boolean isSwitch = false;
2570
2571 /** A list buffer containing all gaps in the finalizer range,
2572 * where a catch all exception should not apply.
2573 */
2574 ListBuffer<Integer> gaps = null;
2575
2576 /** Add given chain to exit chain.
2577 */
2578 void addExit(Chain c) {
2579 exit = Code.mergeChains(c, exit);
2580 }
2581
2582 /** Add given chain to cont chain.
2583 */
2584 void addCont(Chain c) {
2585 cont = Code.mergeChains(c, cont);
2586 }
2587 }
2588
2589 }