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 Type prevPt = this.pt;
881 try {
882 if (tree.type.constValue() != null) {
883 // Short circuit any expressions which are constants
884 tree.accept(classReferenceVisitor);
885 checkStringConstant(tree.pos(), tree.type.constValue());
886 Symbol sym = TreeInfo.symbol(tree);
887 if (sym != null && isConstantDynamic(sym)) {
888 result = items.makeDynamicItem(sym);
889 } else {
890 result = items.makeImmediateItem(tree.type, tree.type.constValue());
891 }
892 } else {
893 this.pt = pt;
894 tree.accept(this);
895 }
896 return result.coerce(pt);
897 } catch (CompletionFailure ex) {
898 chk.completionError(tree.pos(), ex);
899 code.state.stacksize = 1;
900 return items.makeStackItem(pt);
901 } finally {
902 this.pt = prevPt;
903 }
904 }
905
906 public boolean isConstantDynamic(Symbol sym) {
907 return sym.kind == VAR &&
908 sym instanceof DynamicVarSymbol dynamicVarSymbol &&
909 dynamicVarSymbol.isDynamic();
910 }
911
912 /** Derived visitor method: generate code for a list of method arguments.
913 * @param trees The argument expressions to be visited.
914 * @param pts The expression's expected types (i.e. the formal parameter
915 * types of the invoked method).
916 */
917 public void genArgs(List<JCExpression> trees, List<Type> pts) {
918 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
919 genExpr(l.head, pts.head).load();
920 pts = pts.tail;
921 }
922 // require lists be of same length
923 Assert.check(pts.isEmpty());
924 }
925
926 /* ************************************************************************
927 * Visitor methods for statements and definitions
928 *************************************************************************/
929
930 /** Thrown when the byte code size exceeds limit.
931 */
932 public static class CodeSizeOverflow extends RuntimeException {
933 private static final long serialVersionUID = 0;
934 public CodeSizeOverflow() {}
935 }
936
937 public void visitMethodDef(JCMethodDecl tree) {
938 // Create a new local environment that points pack at method
939 // definition.
940 Env<GenContext> localEnv = env.dup(tree);
941 localEnv.enclMethod = tree;
942 // The expected type of every return statement in this method
943 // is the method's return type.
944 this.pt = tree.sym.erasure(types).getReturnType();
945
946 checkDimension(tree.pos(), tree.sym.erasure(types));
947 genMethod(tree, localEnv, false);
948 }
949 //where
950 /** Generate code for a method.
951 * @param tree The tree representing the method definition.
952 * @param env The environment current for the method body.
953 * @param fatcode A flag that indicates whether all jumps are
954 * within 32K. We first invoke this method under
955 * the assumption that fatcode == false, i.e. all
956 * jumps are within 32K. If this fails, fatcode
957 * is set to true and we try again.
958 */
959 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
960 MethodSymbol meth = tree.sym;
961 int extras = 0;
962 // Count up extra parameters
963 if (meth.isConstructor()) {
964 extras++;
965 if (meth.enclClass().isInner() &&
966 !meth.enclClass().isStatic()) {
967 extras++;
968 }
969 } else if ((tree.mods.flags & STATIC) == 0) {
970 extras++;
971 }
972 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
973 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
974 ClassFile.MAX_PARAMETERS) {
975 log.error(tree.pos(), Errors.LimitParameters);
976 nerrs++;
977 }
978
979 else if (tree.body != null) {
980 // Create a new code structure and initialize it.
981 int startpcCrt = initCode(tree, env, fatcode);
982
983 try {
984 genStat(tree.body, env);
985 } catch (CodeSizeOverflow e) {
986 // Failed due to code limit, try again with jsr/ret
987 startpcCrt = initCode(tree, env, fatcode);
988 genStat(tree.body, env);
989 }
990
991 if (code.state.stacksize != 0) {
992 log.error(tree.body.pos(), Errors.StackSimError(tree.sym));
993 throw new AssertionError();
994 }
995
996 // If last statement could complete normally, insert a
997 // return at the end.
998 if (code.isAlive()) {
999 code.statBegin(TreeInfo.endPos(tree.body));
1000 if (env.enclMethod == null ||
1001 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
1002 code.emitop0(return_);
1003 } else if (env.enclMethod.sym.isValueObjectFactory()) {
1004 items.makeLocalItem(env.enclMethod.factoryProduct).load();
1005 code.emitop0(areturn);
1006 } else {
1007 // sometime dead code seems alive (4415991);
1008 // generate a small loop instead
1009 int startpc = code.entryPoint();
1010 CondItem c = items.makeCondItem(goto_);
1011 code.resolve(c.jumpTrue(), startpc);
1012 }
1013 }
1014 if (genCrt)
1015 code.crt.put(tree.body,
1016 CRT_BLOCK,
1017 startpcCrt,
1018 code.curCP());
1019
1020 code.endScopes(0);
1021
1022 // If we exceeded limits, panic
1023 if (code.checkLimits(tree.pos(), log)) {
1024 nerrs++;
1025 return;
1026 }
1027
1028 // If we generated short code but got a long jump, do it again
1029 // with fatCode = true.
1030 if (!fatcode && code.fatcode) genMethod(tree, env, true);
1031
1032 // Clean up
1033 if(stackMap == StackMapFormat.JSR202) {
1034 code.lastFrame = null;
1035 code.frameBeforeLast = null;
1036 }
1037
1038 // Compress exception table
1039 code.compressCatchTable();
1040
1041 // Fill in type annotation positions for exception parameters
1042 code.fillExceptionParameterPositions();
1043 }
1044 }
1045
1046 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1047 MethodSymbol meth = tree.sym;
1048
1049 // Create a new code structure.
1050 meth.code = code = new Code(meth,
1051 fatcode,
1052 lineDebugInfo ? toplevel.lineMap : null,
1053 varDebugInfo,
1054 stackMap,
1055 debugCode,
1056 genCrt ? new CRTable(tree, env.toplevel.endPositions)
1057 : null,
1058 syms,
1059 types,
1060 poolWriter);
1061 items = new Items(poolWriter, code, syms, types);
1062 if (code.debugCode) {
1063 System.err.println(meth + " for body " + tree);
1064 }
1065
1066 // If method is not static, create a new local variable address
1067 // for `this'.
1068 if ((tree.mods.flags & STATIC) == 0) {
1069 Type selfType = meth.owner.type;
1070 if (meth.isConstructor() && selfType != syms.objectType)
1071 selfType = UninitializedType.uninitializedThis(selfType);
1072 code.setDefined(
1073 code.newLocal(
1074 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1075 }
1076
1077 // Mark all parameters as defined from the beginning of
1078 // the method.
1079 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1080 checkDimension(l.head.pos(), l.head.sym.type);
1081 code.setDefined(code.newLocal(l.head.sym));
1082 }
1083
1084 // Get ready to generate code for method body.
1085 int startpcCrt = genCrt ? code.curCP() : 0;
1086 code.entryPoint();
1087
1088 // Suppress initial stackmap
1089 code.pendingStackMap = false;
1090
1091 return startpcCrt;
1092 }
1093
1094 public void visitVarDef(JCVariableDecl tree) {
1095 VarSymbol v = tree.sym;
1096 if (tree.init != null) {
1097 checkStringConstant(tree.init.pos(), v.getConstValue());
1098 if (v.getConstValue() == null || varDebugInfo) {
1099 Assert.check(code.isStatementStart());
1100 code.newLocal(v);
1101 genExpr(tree.init, v.erasure(types)).load();
1102 items.makeLocalItem(v).store();
1103 Assert.check(code.isStatementStart());
1104 }
1105 } else {
1106 code.newLocal(v);
1107 }
1108 checkDimension(tree.pos(), v.type);
1109 Type localType = v.erasure(types);
1110 if (localType.requiresPreload(env.enclClass.sym)) {
1111 poolWriter.enterPreloadClass((ClassSymbol) localType.tsym);
1112 }
1113 }
1114
1115 public void visitSkip(JCSkip tree) {
1116 }
1117
1118 public void visitBlock(JCBlock tree) {
1119 int limit = code.nextreg;
1120 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1121 genStats(tree.stats, localEnv);
1122 // End the scope of all block-local variables in variable info.
1123 if (!env.tree.hasTag(METHODDEF)) {
1124 code.statBegin(tree.endpos);
1125 code.endScopes(limit);
1126 code.pendingStatPos = Position.NOPOS;
1127 }
1128 }
1129
1130 public void visitDoLoop(JCDoWhileLoop tree) {
1131 genLoop(tree, tree.body, tree.cond, List.nil(), false);
1132 }
1133
1134 public void visitWhileLoop(JCWhileLoop tree) {
1135 genLoop(tree, tree.body, tree.cond, List.nil(), true);
1136 }
1137
1138 public void visitWithField(JCWithField tree) {
1139 switch(tree.field.getTag()) {
1140 case IDENT:
1141 Symbol sym = ((JCIdent) tree.field).sym;
1142 items.makeThisItem().load();
1143 genExpr(tree.value, tree.field.type).load();
1144 sym = binaryQualifier(sym, env.enclClass.type);
1145 code.emitop2(withfield, sym, PoolWriter::putMember);
1146 result = items.makeStackItem(tree.type);
1147 break;
1148 case SELECT:
1149 JCFieldAccess fieldAccess = (JCFieldAccess) tree.field;
1150 sym = TreeInfo.symbol(fieldAccess);
1151 // JDK-8207332: To maintain the order of side effects, must compute value ahead of field
1152 genExpr(tree.value, tree.field.type).load();
1153 genExpr(fieldAccess.selected, fieldAccess.selected.type).load();
1154 if (Code.width(tree.field.type) == 2) {
1155 code.emitop0(dup_x2);
1156 code.emitop0(pop);
1157 } else {
1158 code.emitop0(swap);
1159 }
1160 sym = binaryQualifier(sym, fieldAccess.selected.type);
1161 code.emitop2(withfield, sym, PoolWriter::putMember);
1162 result = items.makeStackItem(tree.type);
1163 break;
1164 default:
1165 Assert.check(false);
1166 }
1167 }
1168
1169 public void visitForLoop(JCForLoop tree) {
1170 int limit = code.nextreg;
1171 genStats(tree.init, env);
1172 genLoop(tree, tree.body, tree.cond, tree.step, true);
1173 code.endScopes(limit);
1174 }
1175 //where
1176 /** Generate code for a loop.
1177 * @param loop The tree representing the loop.
1178 * @param body The loop's body.
1179 * @param cond The loop's controlling condition.
1180 * @param step "Step" statements to be inserted at end of
1181 * each iteration.
1182 * @param testFirst True if the loop test belongs before the body.
1183 */
1184 private void genLoop(JCStatement loop,
1185 JCStatement body,
1186 JCExpression cond,
1187 List<JCExpressionStatement> step,
1188 boolean testFirst) {
1189 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1190 int startpc = code.entryPoint();
1191 if (testFirst) { //while or for loop
1192 CondItem c;
1193 if (cond != null) {
1194 code.statBegin(cond.pos);
1195 Assert.check(code.isStatementStart());
1196 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1197 } else {
1198 c = items.makeCondItem(goto_);
1199 }
1200 Chain loopDone = c.jumpFalse();
1201 code.resolve(c.trueJumps);
1202 Assert.check(code.isStatementStart());
1203 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1204 code.resolve(loopEnv.info.cont);
1205 genStats(step, loopEnv);
1206 code.resolve(code.branch(goto_), startpc);
1207 code.resolve(loopDone);
1208 } else {
1209 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1210 code.resolve(loopEnv.info.cont);
1211 genStats(step, loopEnv);
1212 if (code.isAlive()) {
1213 CondItem c;
1214 if (cond != null) {
1215 code.statBegin(cond.pos);
1216 Assert.check(code.isStatementStart());
1217 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1218 } else {
1219 c = items.makeCondItem(goto_);
1220 }
1221 code.resolve(c.jumpTrue(), startpc);
1222 Assert.check(code.isStatementStart());
1223 code.resolve(c.falseJumps);
1224 }
1225 }
1226 Chain exit = loopEnv.info.exit;
1227 if (exit != null) {
1228 code.resolve(exit);
1229 exit.state.defined.excludeFrom(code.nextreg);
1230 }
1231 }
1232
1233 public void visitForeachLoop(JCEnhancedForLoop tree) {
1234 throw new AssertionError(); // should have been removed by Lower.
1235 }
1236
1237 public void visitLabelled(JCLabeledStatement tree) {
1238 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1239 genStat(tree.body, localEnv, CRT_STATEMENT);
1240 Chain exit = localEnv.info.exit;
1241 if (exit != null) {
1242 code.resolve(exit);
1243 exit.state.defined.excludeFrom(code.nextreg);
1244 }
1245 }
1246
1247 public void visitSwitch(JCSwitch tree) {
1248 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1249 }
1250
1251 @Override
1252 public void visitSwitchExpression(JCSwitchExpression tree) {
1253 code.resolvePending();
1254 boolean prevInCondSwitchExpression = inCondSwitchExpression;
1255 try {
1256 inCondSwitchExpression = false;
1257 doHandleSwitchExpression(tree);
1258 } finally {
1259 inCondSwitchExpression = prevInCondSwitchExpression;
1260 }
1261 result = items.makeStackItem(pt);
1262 }
1263
1264 private void doHandleSwitchExpression(JCSwitchExpression tree) {
1265 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
1266 LocalItem prevSwitchResult = switchResult;
1267 int limit = code.nextreg;
1268 try {
1269 stackBeforeSwitchExpression = List.nil();
1270 switchResult = null;
1271 if (hasTry(tree)) {
1272 //if the switch expression contains try-catch, the catch handlers need to have
1273 //an empty stack. So stash whole stack to local variables, and restore it before
1274 //breaks:
1275 while (code.state.stacksize > 0) {
1276 Type type = code.state.peek();
1277 Name varName = names.fromString(target.syntheticNameChar() +
1278 "stack" +
1279 target.syntheticNameChar() +
1280 tree.pos +
1281 target.syntheticNameChar() +
1282 code.state.stacksize);
1283 VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type,
1284 this.env.enclMethod.sym);
1285 LocalItem item = items.new LocalItem(type, code.newLocal(var));
1286 stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item);
1287 item.store();
1288 }
1289 switchResult = makeTemp(tree.type);
1290 }
1291 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
1292 try {
1293 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1294 } finally {
1295 code.setLetExprStackPos(prevLetExprStart);
1296 }
1297 } finally {
1298 stackBeforeSwitchExpression = prevStackBeforeSwitchExpression;
1299 switchResult = prevSwitchResult;
1300 code.endScopes(limit);
1301 }
1302 }
1303 //where:
1304 private boolean hasTry(JCSwitchExpression tree) {
1305 boolean[] hasTry = new boolean[1];
1306 new TreeScanner() {
1307 @Override
1308 public void visitTry(JCTry tree) {
1309 hasTry[0] = true;
1310 }
1311
1312 @Override
1313 public void visitClassDef(JCClassDecl tree) {
1314 }
1315
1316 @Override
1317 public void visitLambda(JCLambda tree) {
1318 }
1319 }.scan(tree);
1320 return hasTry[0];
1321 }
1322
1323 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases,
1324 boolean patternSwitch) {
1325 int limit = code.nextreg;
1326 Assert.check(!selector.type.hasTag(CLASS));
1327 int switchStart = patternSwitch ? code.entryPoint() : -1;
1328 int startpcCrt = genCrt ? code.curCP() : 0;
1329 Assert.check(code.isStatementStart());
1330 Item sel = genExpr(selector, syms.intType);
1331 if (cases.isEmpty()) {
1332 // We are seeing: switch <sel> {}
1333 sel.load().drop();
1334 if (genCrt)
1335 code.crt.put(TreeInfo.skipParens(selector),
1336 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1337 } else {
1338 // We are seeing a nonempty switch.
1339 sel.load();
1340 if (genCrt)
1341 code.crt.put(TreeInfo.skipParens(selector),
1342 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1343 Env<GenContext> switchEnv = env.dup(swtch, new GenContext());
1344 switchEnv.info.isSwitch = true;
1345
1346 // Compute number of labels and minimum and maximum label values.
1347 // For each case, store its label in an array.
1348 int lo = Integer.MAX_VALUE; // minimum label.
1349 int hi = Integer.MIN_VALUE; // maximum label.
1350 int nlabels = 0; // number of labels.
1351
1352 int[] labels = new int[cases.length()]; // the label array.
1353 int defaultIndex = -1; // the index of the default clause.
1354
1355 List<JCCase> l = cases;
1356 for (int i = 0; i < labels.length; i++) {
1357 if (l.head.labels.head.isExpression()) {
1358 Assert.check(l.head.labels.size() == 1);
1359 int val = ((Number)((JCExpression) l.head.labels.head).type.constValue()).intValue();
1360 labels[i] = val;
1361 if (val < lo) lo = val;
1362 if (hi < val) hi = val;
1363 nlabels++;
1364 } else {
1365 Assert.check(defaultIndex == -1);
1366 defaultIndex = i;
1367 }
1368 l = l.tail;
1369 }
1370
1371 // Determine whether to issue a tableswitch or a lookupswitch
1372 // instruction.
1373 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1374 long table_time_cost = 3; // comparisons
1375 long lookup_space_cost = 3 + 2 * (long) nlabels;
1376 long lookup_time_cost = nlabels;
1377 int opcode =
1378 nlabels > 0 &&
1379 table_space_cost + 3 * table_time_cost <=
1380 lookup_space_cost + 3 * lookup_time_cost
1381 ?
1382 tableswitch : lookupswitch;
1383
1384 int startpc = code.curCP(); // the position of the selector operation
1385 code.emitop0(opcode);
1386 code.align(4);
1387 int tableBase = code.curCP(); // the start of the jump table
1388 int[] offsets = null; // a table of offsets for a lookupswitch
1389 code.emit4(-1); // leave space for default offset
1390 if (opcode == tableswitch) {
1391 code.emit4(lo); // minimum label
1392 code.emit4(hi); // maximum label
1393 for (long i = lo; i <= hi; i++) { // leave space for jump table
1394 code.emit4(-1);
1395 }
1396 } else {
1397 code.emit4(nlabels); // number of labels
1398 for (int i = 0; i < nlabels; i++) {
1399 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1400 }
1401 offsets = new int[labels.length];
1402 }
1403 Code.State stateSwitch = code.state.dup();
1404 code.markDead();
1405
1406 // For each case do:
1407 l = cases;
1408 for (int i = 0; i < labels.length; i++) {
1409 JCCase c = l.head;
1410 l = l.tail;
1411
1412 int pc = code.entryPoint(stateSwitch);
1413 // Insert offset directly into code or else into the
1414 // offsets table.
1415 if (i != defaultIndex) {
1416 if (opcode == tableswitch) {
1417 code.put4(
1418 tableBase + 4 * (labels[i] - lo + 3),
1419 pc - startpc);
1420 } else {
1421 offsets[i] = pc - startpc;
1422 }
1423 } else {
1424 code.put4(tableBase, pc - startpc);
1425 }
1426
1427 // Generate code for the statements in this case.
1428 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1429 }
1430
1431 if (switchEnv.info.cont != null) {
1432 Assert.check(patternSwitch);
1433 code.resolve(switchEnv.info.cont, switchStart);
1434 }
1435
1436 // Resolve all breaks.
1437 Chain exit = switchEnv.info.exit;
1438 if (exit != null) {
1439 code.resolve(exit);
1440 exit.state.defined.excludeFrom(limit);
1441 }
1442
1443 // If we have not set the default offset, we do so now.
1444 if (code.get4(tableBase) == -1) {
1445 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1446 }
1447
1448 if (opcode == tableswitch) {
1449 // Let any unfilled slots point to the default case.
1450 int defaultOffset = code.get4(tableBase);
1451 for (long i = lo; i <= hi; i++) {
1452 int t = (int)(tableBase + 4 * (i - lo + 3));
1453 if (code.get4(t) == -1)
1454 code.put4(t, defaultOffset);
1455 }
1456 } else {
1457 // Sort non-default offsets and copy into lookup table.
1458 if (defaultIndex >= 0)
1459 for (int i = defaultIndex; i < labels.length - 1; i++) {
1460 labels[i] = labels[i+1];
1461 offsets[i] = offsets[i+1];
1462 }
1463 if (nlabels > 0)
1464 qsort2(labels, offsets, 0, nlabels - 1);
1465 for (int i = 0; i < nlabels; i++) {
1466 int caseidx = tableBase + 8 * (i + 1);
1467 code.put4(caseidx, labels[i]);
1468 code.put4(caseidx + 4, offsets[i]);
1469 }
1470 }
1471 }
1472 code.endScopes(limit);
1473 }
1474 //where
1475 /** Sort (int) arrays of keys and values
1476 */
1477 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1478 int i = lo;
1479 int j = hi;
1480 int pivot = keys[(i+j)/2];
1481 do {
1482 while (keys[i] < pivot) i++;
1483 while (pivot < keys[j]) j--;
1484 if (i <= j) {
1485 int temp1 = keys[i];
1486 keys[i] = keys[j];
1487 keys[j] = temp1;
1488 int temp2 = values[i];
1489 values[i] = values[j];
1490 values[j] = temp2;
1491 i++;
1492 j--;
1493 }
1494 } while (i <= j);
1495 if (lo < j) qsort2(keys, values, lo, j);
1496 if (i < hi) qsort2(keys, values, i, hi);
1497 }
1498
1499 public void visitSynchronized(JCSynchronized tree) {
1500 int limit = code.nextreg;
1501 // Generate code to evaluate lock and save in temporary variable.
1502 final LocalItem lockVar = makeTemp(syms.objectType);
1503 Assert.check(code.isStatementStart());
1504 genExpr(tree.lock, tree.lock.type).load().duplicate();
1505 lockVar.store();
1506
1507 // Generate code to enter monitor.
1508 code.emitop0(monitorenter);
1509 code.state.lock(lockVar.reg);
1510
1511 // Generate code for a try statement with given body, no catch clauses
1512 // in a new environment with the "exit-monitor" operation as finalizer.
1513 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1514 syncEnv.info.finalize = new GenFinalizer() {
1515 void gen() {
1516 genLast();
1517 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1518 syncEnv.info.gaps.append(code.curCP());
1519 }
1520 void genLast() {
1521 if (code.isAlive()) {
1522 lockVar.load();
1523 code.emitop0(monitorexit);
1524 code.state.unlock(lockVar.reg);
1525 }
1526 }
1527 };
1528 syncEnv.info.gaps = new ListBuffer<>();
1529 genTry(tree.body, List.nil(), syncEnv);
1530 code.endScopes(limit);
1531 }
1532
1533 public void visitTry(final JCTry tree) {
1534 // Generate code for a try statement with given body and catch clauses,
1535 // in a new environment which calls the finally block if there is one.
1536 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1537 final Env<GenContext> oldEnv = env;
1538 tryEnv.info.finalize = new GenFinalizer() {
1539 void gen() {
1540 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1541 tryEnv.info.gaps.append(code.curCP());
1542 genLast();
1543 }
1544 void genLast() {
1545 if (tree.finalizer != null)
1546 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1547 }
1548 boolean hasFinalizer() {
1549 return tree.finalizer != null;
1550 }
1551
1552 @Override
1553 void afterBody() {
1554 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1555 //for body-only finally, remove the GenFinalizer after try body
1556 //so that the finally is not generated to catch bodies:
1557 tryEnv.info.finalize = null;
1558 }
1559 }
1560
1561 };
1562 tryEnv.info.gaps = new ListBuffer<>();
1563 genTry(tree.body, tree.catchers, tryEnv);
1564 }
1565 //where
1566 /** Generate code for a try or synchronized statement
1567 * @param body The body of the try or synchronized statement.
1568 * @param catchers The list of catch clauses.
1569 * @param env The current environment of the body.
1570 */
1571 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1572 int limit = code.nextreg;
1573 int startpc = code.curCP();
1574 Code.State stateTry = code.state.dup();
1575 genStat(body, env, CRT_BLOCK);
1576 int endpc = code.curCP();
1577 List<Integer> gaps = env.info.gaps.toList();
1578 code.statBegin(TreeInfo.endPos(body));
1579 genFinalizer(env);
1580 code.statBegin(TreeInfo.endPos(env.tree));
1581 Chain exitChain;
1582 boolean actualTry = env.tree.hasTag(TRY);
1583 if (startpc == endpc && actualTry) {
1584 exitChain = code.branch(dontgoto);
1585 } else {
1586 exitChain = code.branch(goto_);
1587 }
1588 endFinalizerGap(env);
1589 env.info.finalize.afterBody();
1590 boolean hasFinalizer =
1591 env.info.finalize != null &&
1592 env.info.finalize.hasFinalizer();
1593 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1594 // start off with exception on stack
1595 code.entryPoint(stateTry, l.head.param.sym.type);
1596 genCatch(l.head, env, startpc, endpc, gaps);
1597 genFinalizer(env);
1598 if (hasFinalizer || l.tail.nonEmpty()) {
1599 code.statBegin(TreeInfo.endPos(env.tree));
1600 exitChain = Code.mergeChains(exitChain,
1601 code.branch(goto_));
1602 }
1603 endFinalizerGap(env);
1604 }
1605 if (hasFinalizer && (startpc != endpc || !actualTry)) {
1606 // Create a new register segment to avoid allocating
1607 // the same variables in finalizers and other statements.
1608 code.newRegSegment();
1609
1610 // Add a catch-all clause.
1611
1612 // start off with exception on stack
1613 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1614
1615 // Register all exception ranges for catch all clause.
1616 // The range of the catch all clause is from the beginning
1617 // of the try or synchronized block until the present
1618 // code pointer excluding all gaps in the current
1619 // environment's GenContext.
1620 int startseg = startpc;
1621 while (env.info.gaps.nonEmpty()) {
1622 int endseg = env.info.gaps.next().intValue();
1623 registerCatch(body.pos(), startseg, endseg,
1624 catchallpc, 0);
1625 startseg = env.info.gaps.next().intValue();
1626 }
1627 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1628 code.markStatBegin();
1629
1630 Item excVar = makeTemp(syms.throwableType);
1631 excVar.store();
1632 genFinalizer(env);
1633 code.resolvePending();
1634 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1635 code.markStatBegin();
1636
1637 excVar.load();
1638 registerCatch(body.pos(), startseg,
1639 env.info.gaps.next().intValue(),
1640 catchallpc, 0);
1641 code.emitop0(athrow);
1642 code.markDead();
1643
1644 // If there are jsr's to this finalizer, ...
1645 if (env.info.cont != null) {
1646 // Resolve all jsr's.
1647 code.resolve(env.info.cont);
1648
1649 // Mark statement line number
1650 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1651 code.markStatBegin();
1652
1653 // Save return address.
1654 LocalItem retVar = makeTemp(syms.throwableType);
1655 retVar.store();
1656
1657 // Generate finalizer code.
1658 env.info.finalize.genLast();
1659
1660 // Return.
1661 code.emitop1w(ret, retVar.reg);
1662 code.markDead();
1663 }
1664 }
1665 // Resolve all breaks.
1666 code.resolve(exitChain);
1667
1668 code.endScopes(limit);
1669 }
1670
1671 /** Generate code for a catch clause.
1672 * @param tree The catch clause.
1673 * @param env The environment current in the enclosing try.
1674 * @param startpc Start pc of try-block.
1675 * @param endpc End pc of try-block.
1676 */
1677 void genCatch(JCCatch tree,
1678 Env<GenContext> env,
1679 int startpc, int endpc,
1680 List<Integer> gaps) {
1681 if (startpc != endpc) {
1682 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs
1683 = catchTypesWithAnnotations(tree);
1684 while (gaps.nonEmpty()) {
1685 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1686 JCExpression subCatch = subCatch1.snd;
1687 int catchType = makeRef(tree.pos(), subCatch.type);
1688 int end = gaps.head.intValue();
1689 registerCatch(tree.pos(),
1690 startpc, end, code.curCP(),
1691 catchType);
1692 for (Attribute.TypeCompound tc : subCatch1.fst) {
1693 tc.position.setCatchInfo(catchType, startpc);
1694 }
1695 }
1696 gaps = gaps.tail;
1697 startpc = gaps.head.intValue();
1698 gaps = gaps.tail;
1699 }
1700 if (startpc < endpc) {
1701 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1702 JCExpression subCatch = subCatch1.snd;
1703 int catchType = makeRef(tree.pos(), subCatch.type);
1704 registerCatch(tree.pos(),
1705 startpc, endpc, code.curCP(),
1706 catchType);
1707 for (Attribute.TypeCompound tc : subCatch1.fst) {
1708 tc.position.setCatchInfo(catchType, startpc);
1709 }
1710 }
1711 }
1712 VarSymbol exparam = tree.param.sym;
1713 code.statBegin(tree.pos);
1714 code.markStatBegin();
1715 int limit = code.nextreg;
1716 code.newLocal(exparam);
1717 items.makeLocalItem(exparam).store();
1718 code.statBegin(TreeInfo.firstStatPos(tree.body));
1719 genStat(tree.body, env, CRT_BLOCK);
1720 code.endScopes(limit);
1721 code.statBegin(TreeInfo.endPos(tree.body));
1722 }
1723 }
1724 // where
1725 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) {
1726 return TreeInfo.isMultiCatch(tree) ?
1727 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) :
1728 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype));
1729 }
1730 // where
1731 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) {
1732 List<JCExpression> alts = tree.alternatives;
1733 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head));
1734 alts = alts.tail;
1735
1736 while(alts != null && alts.head != null) {
1737 JCExpression alt = alts.head;
1738 if (alt instanceof JCAnnotatedType annotatedType) {
1739 res = res.prepend(new Pair<>(annotate.fromAnnotations(annotatedType.annotations), alt));
1740 } else {
1741 res = res.prepend(new Pair<>(List.nil(), alt));
1742 }
1743 alts = alts.tail;
1744 }
1745 return res.reverse();
1746 }
1747
1748 /** Register a catch clause in the "Exceptions" code-attribute.
1749 */
1750 void registerCatch(DiagnosticPosition pos,
1751 int startpc, int endpc,
1752 int handler_pc, int catch_type) {
1753 char startpc1 = (char)startpc;
1754 char endpc1 = (char)endpc;
1755 char handler_pc1 = (char)handler_pc;
1756 if (startpc1 == startpc &&
1757 endpc1 == endpc &&
1758 handler_pc1 == handler_pc) {
1759 code.addCatch(startpc1, endpc1, handler_pc1,
1760 (char)catch_type);
1761 } else {
1762 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1763 nerrs++;
1764 }
1765 }
1766
1767 public void visitIf(JCIf tree) {
1768 int limit = code.nextreg;
1769 Chain thenExit = null;
1770 Assert.check(code.isStatementStart());
1771 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1772 CRT_FLOW_CONTROLLER);
1773 Chain elseChain = c.jumpFalse();
1774 Assert.check(code.isStatementStart());
1775 if (!c.isFalse()) {
1776 code.resolve(c.trueJumps);
1777 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1778 thenExit = code.branch(goto_);
1779 }
1780 if (elseChain != null) {
1781 code.resolve(elseChain);
1782 if (tree.elsepart != null) {
1783 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1784 }
1785 }
1786 code.resolve(thenExit);
1787 code.endScopes(limit);
1788 Assert.check(code.isStatementStart());
1789 }
1790
1791 public void visitExec(JCExpressionStatement tree) {
1792 // Optimize x++ to ++x and x-- to --x.
1793 JCExpression e = tree.expr;
1794 switch (e.getTag()) {
1795 case POSTINC:
1796 ((JCUnary) e).setTag(PREINC);
1797 break;
1798 case POSTDEC:
1799 ((JCUnary) e).setTag(PREDEC);
1800 break;
1801 }
1802 Assert.check(code.isStatementStart());
1803 genExpr(tree.expr, tree.expr.type).drop();
1804 Assert.check(code.isStatementStart());
1805 }
1806
1807 public void visitBreak(JCBreak tree) {
1808 Assert.check(code.isStatementStart());
1809 final Env<GenContext> targetEnv = unwindBreak(tree.target);
1810 targetEnv.info.addExit(code.branch(goto_));
1811 endFinalizerGaps(env, targetEnv);
1812 }
1813
1814 public void visitYield(JCYield tree) {
1815 Assert.check(code.isStatementStart());
1816 final Env<GenContext> targetEnv;
1817 if (inCondSwitchExpression) {
1818 CondItem value = genCond(tree.value, CRT_FLOW_TARGET);
1819 Chain falseJumps = value.jumpFalse();
1820
1821 code.resolve(value.trueJumps);
1822 Env<GenContext> localEnv = unwindBreak(tree.target);
1823 reloadStackBeforeSwitchExpr();
1824 Chain trueJumps = code.branch(goto_);
1825
1826 endFinalizerGaps(env, localEnv);
1827
1828 code.resolve(falseJumps);
1829 targetEnv = unwindBreak(tree.target);
1830 reloadStackBeforeSwitchExpr();
1831 falseJumps = code.branch(goto_);
1832
1833 if (switchExpressionTrueChain == null) {
1834 switchExpressionTrueChain = trueJumps;
1835 } else {
1836 switchExpressionTrueChain =
1837 Code.mergeChains(switchExpressionTrueChain, trueJumps);
1838 }
1839 if (switchExpressionFalseChain == null) {
1840 switchExpressionFalseChain = falseJumps;
1841 } else {
1842 switchExpressionFalseChain =
1843 Code.mergeChains(switchExpressionFalseChain, falseJumps);
1844 }
1845 } else {
1846 genExpr(tree.value, pt).load();
1847 if (switchResult != null)
1848 switchResult.store();
1849
1850 targetEnv = unwindBreak(tree.target);
1851
1852 if (code.isAlive()) {
1853 reloadStackBeforeSwitchExpr();
1854 if (switchResult != null)
1855 switchResult.load();
1856
1857 code.state.forceStackTop(tree.target.type);
1858 targetEnv.info.addExit(code.branch(goto_));
1859 code.markDead();
1860 }
1861 }
1862 endFinalizerGaps(env, targetEnv);
1863 }
1864 //where:
1865 /** As side-effect, might mark code as dead disabling any further emission.
1866 */
1867 private Env<GenContext> unwindBreak(JCTree target) {
1868 int tmpPos = code.pendingStatPos;
1869 Env<GenContext> targetEnv = unwind(target, env);
1870 code.pendingStatPos = tmpPos;
1871 return targetEnv;
1872 }
1873
1874 private void reloadStackBeforeSwitchExpr() {
1875 for (LocalItem li : stackBeforeSwitchExpression)
1876 li.load();
1877 }
1878
1879 public void visitContinue(JCContinue tree) {
1880 int tmpPos = code.pendingStatPos;
1881 Env<GenContext> targetEnv = unwind(tree.target, env);
1882 code.pendingStatPos = tmpPos;
1883 Assert.check(code.isStatementStart());
1884 targetEnv.info.addCont(code.branch(goto_));
1885 endFinalizerGaps(env, targetEnv);
1886 }
1887
1888 public void visitReturn(JCReturn tree) {
1889 int limit = code.nextreg;
1890 final Env<GenContext> targetEnv;
1891
1892 /* Save and then restore the location of the return in case a finally
1893 * is expanded (with unwind()) in the middle of our bytecodes.
1894 */
1895 int tmpPos = code.pendingStatPos;
1896 if (tree.expr != null) {
1897 Assert.check(code.isStatementStart());
1898 Item r = genExpr(tree.expr, pt).load();
1899 if (hasFinally(env.enclMethod, env)) {
1900 r = makeTemp(pt);
1901 r.store();
1902 }
1903 targetEnv = unwind(env.enclMethod, env);
1904 code.pendingStatPos = tmpPos;
1905 r.load();
1906 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
1907 } else {
1908 targetEnv = unwind(env.enclMethod, env);
1909 code.pendingStatPos = tmpPos;
1910 code.emitop0(return_);
1911 }
1912 endFinalizerGaps(env, targetEnv);
1913 code.endScopes(limit);
1914 }
1915
1916 public void visitThrow(JCThrow tree) {
1917 Assert.check(code.isStatementStart());
1918 genExpr(tree.expr, tree.expr.type).load();
1919 code.emitop0(athrow);
1920 Assert.check(code.isStatementStart());
1921 }
1922
1923 /* ************************************************************************
1924 * Visitor methods for expressions
1925 *************************************************************************/
1926
1927 public void visitApply(JCMethodInvocation tree) {
1928 setTypeAnnotationPositions(tree.pos);
1929 // Generate code for method.
1930 Item m = genExpr(tree.meth, methodType);
1931 // Generate code for all arguments, where the expected types are
1932 // the parameters of the method's external type (that is, any implicit
1933 // outer instance of a super(...) call appears as first parameter).
1934 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
1935 genArgs(tree.args,
1936 msym.externalType(types).getParameterTypes());
1937 if (!msym.isDynamic()) {
1938 code.statBegin(tree.pos);
1939 }
1940 result = m.invoke();
1941 }
1942
1943 public void visitConditional(JCConditional tree) {
1944 Chain thenExit = null;
1945 code.statBegin(tree.cond.pos);
1946 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
1947 Chain elseChain = c.jumpFalse();
1948 if (!c.isFalse()) {
1949 code.resolve(c.trueJumps);
1950 int startpc = genCrt ? code.curCP() : 0;
1951 code.statBegin(tree.truepart.pos);
1952 genExpr(tree.truepart, pt).load();
1953 code.state.forceStackTop(tree.type);
1954 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
1955 startpc, code.curCP());
1956 thenExit = code.branch(goto_);
1957 }
1958 if (elseChain != null) {
1959 code.resolve(elseChain);
1960 int startpc = genCrt ? code.curCP() : 0;
1961 code.statBegin(tree.falsepart.pos);
1962 genExpr(tree.falsepart, pt).load();
1963 code.state.forceStackTop(tree.type);
1964 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
1965 startpc, code.curCP());
1966 }
1967 code.resolve(thenExit);
1968 result = items.makeStackItem(pt);
1969 }
1970
1971 private void setTypeAnnotationPositions(int treePos) {
1972 MethodSymbol meth = code.meth;
1973 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR
1974 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT;
1975
1976 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
1977 if (ta.hasUnknownPosition())
1978 ta.tryFixPosition();
1979
1980 if (ta.position.matchesPos(treePos))
1981 ta.position.updatePosOffset(code.cp);
1982 }
1983
1984 if (!initOrClinit)
1985 return;
1986
1987 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
1988 if (ta.hasUnknownPosition())
1989 ta.tryFixPosition();
1990
1991 if (ta.position.matchesPos(treePos))
1992 ta.position.updatePosOffset(code.cp);
1993 }
1994
1995 ClassSymbol clazz = meth.enclClass();
1996 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
1997 if (!s.getKind().isField())
1998 continue;
1999
2000 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
2001 if (ta.hasUnknownPosition())
2002 ta.tryFixPosition();
2003
2004 if (ta.position.matchesPos(treePos))
2005 ta.position.updatePosOffset(code.cp);
2006 }
2007 }
2008 }
2009
2010 public void visitNewClass(JCNewClass tree) {
2011 // Enclosing instances or anonymous classes should have been eliminated
2012 // by now.
2013 Assert.check(tree.encl == null && tree.def == null);
2014 setTypeAnnotationPositions(tree.pos);
2015
2016 code.emitop2(new_, checkDimension(tree.pos(), tree.type), PoolWriter::putClass);
2017 code.emitop0(dup);
2018
2019 // Generate code for all arguments, where the expected types are
2020 // the parameters of the constructor's external type (that is,
2021 // any implicit outer instance appears as first parameter).
2022 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
2023
2024 items.makeMemberItem(tree.constructor, true).invoke();
2025
2026 result = items.makeStackItem(tree.type);
2027 }
2028
2029 public void visitNewArray(JCNewArray tree) {
2030 setTypeAnnotationPositions(tree.pos);
2031
2032 if (tree.elems != null) {
2033 Type elemtype = types.elemtype(tree.type);
2034 loadIntConst(tree.elems.length());
2035 Item arr = makeNewArray(tree.pos(), tree.type, 1);
2036 int i = 0;
2037 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
2038 arr.duplicate();
2039 loadIntConst(i);
2040 i++;
2041 genExpr(l.head, elemtype).load();
2042 items.makeIndexedItem(elemtype).store();
2043 }
2044 result = arr;
2045 } else {
2046 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
2047 genExpr(l.head, syms.intType).load();
2048 }
2049 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
2050 }
2051 }
2052 //where
2053 /** Generate code to create an array with given element type and number
2054 * of dimensions.
2055 */
2056 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
2057 Type elemtype = types.elemtype(type);
2058 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
2059 log.error(pos, Errors.LimitDimensions);
2060 nerrs++;
2061 }
2062 int elemcode = Code.arraycode(elemtype);
2063 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
2064 code.emitAnewarray(makeRef(pos, elemtype, elemtype.isPrimitiveClass()), type);
2065 } else if (elemcode == 1) {
2066 code.emitMultianewarray(ndims, makeRef(pos, type), type);
2067 } else {
2068 code.emitNewarray(elemcode, type);
2069 }
2070 return items.makeStackItem(type);
2071 }
2072
2073 public void visitParens(JCParens tree) {
2074 result = genExpr(tree.expr, tree.expr.type);
2075 }
2076
2077 public void visitAssign(JCAssign tree) {
2078 Item l = genExpr(tree.lhs, tree.lhs.type);
2079 genExpr(tree.rhs, tree.lhs.type).load();
2080 if (tree.rhs.type.hasTag(BOT)) {
2081 /* This is just a case of widening reference conversion that per 5.1.5 simply calls
2082 for "regarding a reference as having some other type in a manner that can be proved
2083 correct at compile time."
2084 */
2085 code.state.forceStackTop(tree.lhs.type);
2086 }
2087 result = items.makeAssignItem(l);
2088 }
2089
2090 public void visitAssignop(JCAssignOp tree) {
2091 OperatorSymbol operator = tree.operator;
2092 Item l;
2093 if (operator.opcode == string_add) {
2094 l = concat.makeConcat(tree);
2095 } else {
2096 // Generate code for first expression
2097 l = genExpr(tree.lhs, tree.lhs.type);
2098
2099 // If we have an increment of -32768 to +32767 of a local
2100 // int variable we can use an incr instruction instead of
2101 // proceeding further.
2102 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
2103 l instanceof LocalItem localItem &&
2104 tree.lhs.type.getTag().isSubRangeOf(INT) &&
2105 tree.rhs.type.getTag().isSubRangeOf(INT) &&
2106 tree.rhs.type.constValue() != null) {
2107 int ival = ((Number) tree.rhs.type.constValue()).intValue();
2108 if (tree.hasTag(MINUS_ASG)) ival = -ival;
2109 localItem.incr(ival);
2110 result = l;
2111 return;
2112 }
2113 // Otherwise, duplicate expression, load one copy
2114 // and complete binary operation.
2115 l.duplicate();
2116 l.coerce(operator.type.getParameterTypes().head).load();
2117 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
2118 }
2119 result = items.makeAssignItem(l);
2120 }
2121
2122 public void visitUnary(JCUnary tree) {
2123 OperatorSymbol operator = tree.operator;
2124 if (tree.hasTag(NOT)) {
2125 CondItem od = genCond(tree.arg, false);
2126 result = od.negate();
2127 } else {
2128 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
2129 switch (tree.getTag()) {
2130 case POS:
2131 result = od.load();
2132 break;
2133 case NEG:
2134 result = od.load();
2135 code.emitop0(operator.opcode);
2136 break;
2137 case COMPL:
2138 result = od.load();
2139 emitMinusOne(od.typecode);
2140 code.emitop0(operator.opcode);
2141 break;
2142 case PREINC: case PREDEC:
2143 od.duplicate();
2144 if (od instanceof LocalItem localItem &&
2145 (operator.opcode == iadd || operator.opcode == isub)) {
2146 localItem.incr(tree.hasTag(PREINC) ? 1 : -1);
2147 result = od;
2148 } else {
2149 od.load();
2150 code.emitop0(one(od.typecode));
2151 code.emitop0(operator.opcode);
2152 // Perform narrowing primitive conversion if byte,
2153 // char, or short. Fix for 4304655.
2154 if (od.typecode != INTcode &&
2155 Code.truncate(od.typecode) == INTcode)
2156 code.emitop0(int2byte + od.typecode - BYTEcode);
2157 result = items.makeAssignItem(od);
2158 }
2159 break;
2160 case POSTINC: case POSTDEC:
2161 od.duplicate();
2162 if (od instanceof LocalItem localItem &&
2163 (operator.opcode == iadd || operator.opcode == isub)) {
2164 Item res = od.load();
2165 localItem.incr(tree.hasTag(POSTINC) ? 1 : -1);
2166 result = res;
2167 } else {
2168 Item res = od.load();
2169 od.stash(od.typecode);
2170 code.emitop0(one(od.typecode));
2171 code.emitop0(operator.opcode);
2172 // Perform narrowing primitive conversion if byte,
2173 // char, or short. Fix for 4304655.
2174 if (od.typecode != INTcode &&
2175 Code.truncate(od.typecode) == INTcode)
2176 code.emitop0(int2byte + od.typecode - BYTEcode);
2177 od.store();
2178 result = res;
2179 }
2180 break;
2181 case NULLCHK:
2182 result = od.load();
2183 code.emitop0(dup);
2184 genNullCheck(tree);
2185 break;
2186 default:
2187 Assert.error();
2188 }
2189 }
2190 }
2191
2192 /** Generate a null check from the object value at stack top. */
2193 private void genNullCheck(JCTree tree) {
2194 code.statBegin(tree.pos);
2195 callMethod(tree.pos(), syms.objectsType, names.requireNonNull,
2196 List.of(syms.objectType), true);
2197 code.emitop0(pop);
2198 }
2199
2200 public void visitBinary(JCBinary tree) {
2201 OperatorSymbol operator = tree.operator;
2202 if (operator.opcode == string_add) {
2203 result = concat.makeConcat(tree);
2204 } else if (tree.hasTag(AND)) {
2205 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2206 if (!lcond.isFalse()) {
2207 Chain falseJumps = lcond.jumpFalse();
2208 code.resolve(lcond.trueJumps);
2209 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2210 result = items.
2211 makeCondItem(rcond.opcode,
2212 rcond.trueJumps,
2213 Code.mergeChains(falseJumps,
2214 rcond.falseJumps));
2215 } else {
2216 result = lcond;
2217 }
2218 } else if (tree.hasTag(OR)) {
2219 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2220 if (!lcond.isTrue()) {
2221 Chain trueJumps = lcond.jumpTrue();
2222 code.resolve(lcond.falseJumps);
2223 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2224 result = items.
2225 makeCondItem(rcond.opcode,
2226 Code.mergeChains(trueJumps, rcond.trueJumps),
2227 rcond.falseJumps);
2228 } else {
2229 result = lcond;
2230 }
2231 } else {
2232 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
2233 od.load();
2234 result = completeBinop(tree.lhs, tree.rhs, operator);
2235 }
2236 }
2237
2238
2239 /** Complete generating code for operation, with left operand
2240 * already on stack.
2241 * @param lhs The tree representing the left operand.
2242 * @param rhs The tree representing the right operand.
2243 * @param operator The operator symbol.
2244 */
2245 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2246 MethodType optype = (MethodType)operator.type;
2247 int opcode = operator.opcode;
2248 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2249 rhs.type.constValue() instanceof Number number &&
2250 number.intValue() == 0) {
2251 opcode = opcode + (ifeq - if_icmpeq);
2252 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2253 TreeInfo.isNull(rhs)) {
2254 opcode = opcode + (if_acmp_null - if_acmpeq);
2255 } else {
2256 // The expected type of the right operand is
2257 // the second parameter type of the operator, except for
2258 // shifts with long shiftcount, where we convert the opcode
2259 // to a short shift and the expected type to int.
2260 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2261 if (opcode >= ishll && opcode <= lushrl) {
2262 opcode = opcode + (ishl - ishll);
2263 rtype = syms.intType;
2264 }
2265 // Generate code for right operand and load.
2266 genExpr(rhs, rtype).load();
2267 // If there are two consecutive opcode instructions,
2268 // emit the first now.
2269 if (opcode >= (1 << preShift)) {
2270 code.emitop0(opcode >> preShift);
2271 opcode = opcode & 0xFF;
2272 }
2273 }
2274 if (opcode >= ifeq && opcode <= if_acmpne ||
2275 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2276 return items.makeCondItem(opcode);
2277 } else {
2278 code.emitop0(opcode);
2279 return items.makeStackItem(optype.restype);
2280 }
2281 }
2282
2283 public void visitTypeCast(JCTypeCast tree) {
2284 result = genExpr(tree.expr, tree.clazz.type).load();
2285 setTypeAnnotationPositions(tree.pos);
2286 // Additional code is only needed if we cast to a reference type
2287 // which is not statically a supertype of the expression's type.
2288 // For basic types, the coerce(...) in genExpr(...) will do
2289 // the conversion.
2290 // primitive reference conversion is a nop when we bifurcate the primitive class, as the VM sees a subtyping relationship.
2291 if (!tree.clazz.type.isPrimitive() &&
2292 !types.isSameType(tree.expr.type, tree.clazz.type) &&
2293 (!tree.clazz.type.isReferenceProjection() || !types.isSameType(tree.clazz.type.valueProjection(), tree.expr.type) || true) &&
2294 !types.isSubtype(tree.expr.type, tree.clazz.type)) {
2295 checkDimension(tree.pos(), tree.clazz.type);
2296 if (tree.clazz.type.isPrimitiveClass()) {
2297 code.emitop2(checkcast, new ConstantPoolQType(tree.clazz.type, types), PoolWriter::putClass);
2298 } else {
2299 code.emitop2(checkcast, tree.clazz.type, PoolWriter::putClass);
2300 }
2301
2302 }
2303 }
2304
2305 public void visitWildcard(JCWildcard tree) {
2306 throw new AssertionError(this.getClass().getName());
2307 }
2308
2309 public void visitTypeTest(JCInstanceOf tree) {
2310 genExpr(tree.expr, tree.expr.type).load();
2311 setTypeAnnotationPositions(tree.pos);
2312 code.emitop2(instanceof_, makeRef(tree.pos(), tree.pattern.type));
2313 result = items.makeStackItem(syms.booleanType);
2314 }
2315
2316 public void visitIndexed(JCArrayAccess tree) {
2317 genExpr(tree.indexed, tree.indexed.type).load();
2318 genExpr(tree.index, syms.intType).load();
2319 result = items.makeIndexedItem(tree.type);
2320 }
2321
2322 public void visitIdent(JCIdent tree) {
2323 Symbol sym = tree.sym;
2324 if (tree.name == names._this || tree.name == names._super) {
2325 Item res = tree.name == names._this
2326 ? items.makeThisItem()
2327 : items.makeSuperItem();
2328 if (sym.kind == MTH) {
2329 // Generate code to address the constructor.
2330 res.load();
2331 res = items.makeMemberItem(sym, true);
2332 }
2333 result = res;
2334 } else if (isInvokeDynamic(sym) || isConstantDynamic(sym)) {
2335 if (isConstantDynamic(sym)) {
2336 setTypeAnnotationPositions(tree.pos);
2337 }
2338 result = items.makeDynamicItem(sym);
2339 } else if (sym.kind == VAR && (sym.owner.kind == MTH || sym.owner.kind == VAR)) {
2340 result = items.makeLocalItem((VarSymbol)sym);
2341 } else if ((sym.flags() & STATIC) != 0) {
2342 if (!isAccessSuper(env.enclMethod))
2343 sym = binaryQualifier(sym, env.enclClass.type);
2344 result = items.makeStaticItem(sym);
2345 } else {
2346 items.makeThisItem().load();
2347 sym = binaryQualifier(sym, env.enclClass.type);
2348 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym));
2349 }
2350 }
2351
2352 //where
2353 private boolean nonVirtualForPrivateAccess(Symbol sym) {
2354 boolean useVirtual = target.hasVirtualPrivateInvoke() &&
2355 !disableVirtualizedPrivateInvoke;
2356 return !useVirtual && ((sym.flags() & PRIVATE) != 0);
2357 }
2358
2359 public void visitSelect(JCFieldAccess tree) {
2360 Symbol sym = tree.sym;
2361
2362 if (tree.name == names._class) {
2363 code.emitLdc((LoadableConstant) tree.selected.type, makeRef(tree.pos(), tree.selected.type, tree.selected.type.isPrimitiveClass()));
2364 result = items.makeStackItem(pt);
2365 return;
2366 }
2367
2368 Symbol ssym = TreeInfo.symbol(tree.selected);
2369
2370 // Are we selecting via super?
2371 boolean selectSuper =
2372 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2373
2374 // Are we accessing a member of the superclass in an access method
2375 // resulting from a qualified super?
2376 boolean accessSuper = isAccessSuper(env.enclMethod);
2377
2378 Item base = (selectSuper)
2379 ? items.makeSuperItem()
2380 : genExpr(tree.selected, tree.selected.type);
2381
2382 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2383 // We are seeing a variable that is constant but its selecting
2384 // expression is not.
2385 if ((sym.flags() & STATIC) != 0) {
2386 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2387 base = base.load();
2388 base.drop();
2389 } else {
2390 base.load();
2391 genNullCheck(tree.selected);
2392 }
2393 result = items.
2394 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2395 } else {
2396 if (isInvokeDynamic(sym)) {
2397 result = items.makeDynamicItem(sym);
2398 return;
2399 } else {
2400 sym = binaryQualifier(sym, tree.selected.type);
2401 }
2402 if ((sym.flags() & STATIC) != 0) {
2403 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2404 base = base.load();
2405 base.drop();
2406 result = items.makeStaticItem(sym);
2407 } else {
2408 base.load();
2409 if (sym == syms.lengthVar) {
2410 code.emitop0(arraylength);
2411 result = items.makeStackItem(syms.intType);
2412 } else {
2413 result = items.
2414 makeMemberItem(sym,
2415 nonVirtualForPrivateAccess(sym) ||
2416 selectSuper || accessSuper);
2417 }
2418 }
2419 }
2420 }
2421
2422 public void visitDefaultValue(JCDefaultValue tree) {
2423 if (tree.type.isValueClass()) {
2424 code.emitop2(aconst_init, checkDimension(tree.pos(), tree.type), PoolWriter::putClass);
2425 } else if (tree.type.isReference()) {
2426 code.emitop0(aconst_null);
2427 } else {
2428 code.emitop0(zero(Code.typecode(tree.type)));
2429 }
2430 result = items.makeStackItem(tree.type);
2431 return;
2432 }
2433
2434 public boolean isInvokeDynamic(Symbol sym) {
2435 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
2436 }
2437
2438 public void visitLiteral(JCLiteral tree) {
2439 if (tree.type.hasTag(BOT)) {
2440 code.emitop0(aconst_null);
2441 result = items.makeStackItem(tree.type);
2442 }
2443 else
2444 result = items.makeImmediateItem(tree.type, tree.value);
2445 }
2446
2447 public void visitLetExpr(LetExpr tree) {
2448 code.resolvePending();
2449
2450 int limit = code.nextreg;
2451 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
2452 try {
2453 genStats(tree.defs, env);
2454 } finally {
2455 code.setLetExprStackPos(prevLetExprStart);
2456 }
2457 result = genExpr(tree.expr, tree.expr.type).load();
2458 code.endScopes(limit);
2459 }
2460
2461 private void generateReferencesToPrunedTree(ClassSymbol classSymbol) {
2462 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
2463 if (prunedInfo != null) {
2464 for (JCTree prunedTree: prunedInfo) {
2465 prunedTree.accept(classReferenceVisitor);
2466 }
2467 }
2468 }
2469
2470 /* ************************************************************************
2471 * main method
2472 *************************************************************************/
2473
2474 /** Generate code for a class definition.
2475 * @param env The attribution environment that belongs to the
2476 * outermost class containing this class definition.
2477 * We need this for resolving some additional symbols.
2478 * @param cdef The tree representing the class definition.
2479 * @return True if code is generated with no errors.
2480 */
2481 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2482 try {
2483 attrEnv = env;
2484 ClassSymbol c = cdef.sym;
2485 this.toplevel = env.toplevel;
2486 this.endPosTable = toplevel.endPositions;
2487 /* method normalizeDefs() can add references to external classes into the constant pool
2488 */
2489 cdef.defs = normalizeDefs(cdef.defs, c);
2490 cdef = transValues.translateTopLevelClass(cdef, make);
2491 generateReferencesToPrunedTree(c);
2492 Env<GenContext> localEnv = new Env<>(cdef, new GenContext());
2493 localEnv.toplevel = env.toplevel;
2494 localEnv.enclClass = cdef;
2495
2496 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2497 genDef(l.head, localEnv);
2498 }
2499 if (poolWriter.size() > PoolWriter.MAX_ENTRIES) {
2500 log.error(cdef.pos(), Errors.LimitPool);
2501 nerrs++;
2502 }
2503 if (nerrs != 0) {
2504 // if errors, discard code
2505 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2506 if (l.head.hasTag(METHODDEF))
2507 ((JCMethodDecl) l.head).sym.code = null;
2508 }
2509 }
2510 cdef.defs = List.nil(); // discard trees
2511 return nerrs == 0;
2512 } finally {
2513 // note: this method does NOT support recursion.
2514 attrEnv = null;
2515 this.env = null;
2516 toplevel = null;
2517 endPosTable = null;
2518 nerrs = 0;
2519 qualifiedSymbolCache.clear();
2520 }
2521 }
2522
2523 /* ************************************************************************
2524 * Auxiliary classes
2525 *************************************************************************/
2526
2527 /** An abstract class for finalizer generation.
2528 */
2529 abstract class GenFinalizer {
2530 /** Generate code to clean up when unwinding. */
2531 abstract void gen();
2532
2533 /** Generate code to clean up at last. */
2534 abstract void genLast();
2535
2536 /** Does this finalizer have some nontrivial cleanup to perform? */
2537 boolean hasFinalizer() { return true; }
2538
2539 /** Should be invoked after the try's body has been visited. */
2540 void afterBody() {}
2541 }
2542
2543 /** code generation contexts,
2544 * to be used as type parameter for environments.
2545 */
2546 static class GenContext {
2547
2548 /** A chain for all unresolved jumps that exit the current environment.
2549 */
2550 Chain exit = null;
2551
2552 /** A chain for all unresolved jumps that continue in the
2553 * current environment.
2554 */
2555 Chain cont = null;
2556
2557 /** A closure that generates the finalizer of the current environment.
2558 * Only set for Synchronized and Try contexts.
2559 */
2560 GenFinalizer finalize = null;
2561
2562 /** Is this a switch statement? If so, allocate registers
2563 * even when the variable declaration is unreachable.
2564 */
2565 boolean isSwitch = false;
2566
2567 /** A list buffer containing all gaps in the finalizer range,
2568 * where a catch all exception should not apply.
2569 */
2570 ListBuffer<Integer> gaps = null;
2571
2572 /** Add given chain to exit chain.
2573 */
2574 void addExit(Chain c) {
2575 exit = Code.mergeChains(c, exit);
2576 }
2577
2578 /** Add given chain to cont chain.
2579 */
2580 void addCont(Chain c) {
2581 cont = Code.mergeChains(c, cont);
2582 }
2583 }
2584
2585 }