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 import java.util.Set;
31
32 import com.sun.tools.javac.jvm.PoolConstant.LoadableConstant;
33 import com.sun.tools.javac.tree.TreeInfo.PosKind;
34 import com.sun.tools.javac.util.*;
35 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
36 import com.sun.tools.javac.util.List;
37 import com.sun.tools.javac.code.*;
38 import com.sun.tools.javac.code.Attribute.TypeCompound;
39 import com.sun.tools.javac.code.Symbol.VarSymbol;
40 import com.sun.tools.javac.comp.*;
41 import com.sun.tools.javac.tree.*;
42
43 import com.sun.tools.javac.code.Symbol.*;
44 import com.sun.tools.javac.code.Type.*;
45 import com.sun.tools.javac.jvm.Code.*;
46 import com.sun.tools.javac.jvm.Items.*;
47 import com.sun.tools.javac.resources.CompilerProperties.Errors;
48 import com.sun.tools.javac.tree.EndPosTable;
49 import com.sun.tools.javac.tree.JCTree.*;
50
51 import static com.sun.tools.javac.code.Flags.*;
52 import static com.sun.tools.javac.code.Kinds.Kind.*;
53 import static com.sun.tools.javac.code.TypeTag.*;
54 import static com.sun.tools.javac.jvm.ByteCodes.*;
55 import static com.sun.tools.javac.jvm.CRTFlags.*;
56 import static com.sun.tools.javac.main.Option.*;
57 import static com.sun.tools.javac.tree.JCTree.Tag.*;
58
59 /** This pass maps flat Java (i.e. without inner classes) to bytecodes.
60 *
61 * <p><b>This is NOT part of any supported API.
62 * If you write code that depends on this, you do so at your own risk.
63 * This code and its internal interfaces are subject to change or
64 * deletion without notice.</b>
65 */
66 public class Gen extends JCTree.Visitor {
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 String accessDollar;
77 private final Types types;
78 private final Lower lower;
79 private final Annotate annotate;
80 private final StringConcat concat;
81
82 /** Format of stackmap tables to be generated. */
83 private final Code.StackMapFormat stackMap;
84
85 /** A type that serves as the expected type for all method expressions.
86 */
87 private final Type methodType;
88
89 public static Gen instance(Context context) {
90 Gen instance = context.get(genKey);
91 if (instance == null)
92 instance = new Gen(context);
93 return instance;
94 }
95
96 /** Constant pool writer, set by genClass.
97 */
98 final PoolWriter poolWriter;
99
100 @SuppressWarnings("this-escape")
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 = "access" + target.syntheticNameChar();
116 lower = Lower.instance(context);
117
118 Options options = Options.instance(context);
119 lineDebugInfo =
120 options.isUnset(G_CUSTOM) ||
121 options.isSet(G_CUSTOM, "lines");
122 varDebugInfo =
123 options.isUnset(G_CUSTOM)
124 ? options.isSet(G)
125 : options.isSet(G_CUSTOM, "vars");
126 genCrt = options.isSet(XJCOV);
127 debugCode = options.isSet("debug.code");
128 disableVirtualizedPrivateInvoke = options.isSet("disableVirtualizedPrivateInvoke");
129 poolWriter = new PoolWriter(types, names);
130
131 // ignore cldc because we cannot have both stackmap formats
132 this.stackMap = StackMapFormat.JSR202;
133 annotate = Annotate.instance(context);
134 qualifiedSymbolCache = new HashMap<>();
135 }
136
137 /** Switches
138 */
139 private final boolean lineDebugInfo;
140 private final boolean varDebugInfo;
141 private final boolean genCrt;
142 private final boolean debugCode;
143 private boolean disableVirtualizedPrivateInvoke;
144
145 /** Code buffer, set by genMethod.
146 */
147 private Code code;
148
149 /** Items structure, set by genMethod.
150 */
151 private Items items;
152
153 /** Environment for symbol lookup, set by genClass
154 */
155 private Env<AttrContext> attrEnv;
156
157 /** The top level tree.
158 */
159 private JCCompilationUnit toplevel;
160
161 /** The number of code-gen errors in this class.
162 */
163 private int nerrs = 0;
164
165 /** An object containing mappings of syntax trees to their
166 * ending source positions.
167 */
168 EndPosTable endPosTable;
169
170 boolean inCondSwitchExpression;
171 Chain switchExpressionTrueChain;
172 Chain switchExpressionFalseChain;
173 List<LocalItem> stackBeforeSwitchExpression;
174 LocalItem switchResult;
175 Set<JCMethodInvocation> invocationsWithPatternMatchingCatch = Set.of();
176 ListBuffer<int[]> patternMatchingInvocationRanges;
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) {
273 return poolWriter.putClass(checkDimension(pos, type));
274 }
275
276 /** Check if the given type is an array with too many dimensions.
277 */
278 private Type checkDimension(DiagnosticPosition pos, Type t) {
279 checkDimensionInternal(pos, t);
280 return t;
281 }
282
283 private void checkDimensionInternal(DiagnosticPosition pos, Type t) {
284 switch (t.getTag()) {
285 case METHOD:
286 checkDimension(pos, t.getReturnType());
287 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail)
288 checkDimension(pos, args.head);
289 break;
290 case ARRAY:
291 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) {
292 log.error(pos, Errors.LimitDimensions);
293 nerrs++;
294 }
295 break;
296 default:
297 break;
298 }
299 }
300
301 /** Create a temporary variable.
302 * @param type The variable's type.
303 */
304 LocalItem makeTemp(Type type) {
305 VarSymbol v = new VarSymbol(Flags.SYNTHETIC,
306 names.empty,
307 type,
308 env.enclMethod.sym);
309 code.newLocal(v);
310 return items.makeLocalItem(v);
311 }
312
313 /** Generate code to call a non-private method or constructor.
314 * @param pos Position to be used for error reporting.
315 * @param site The type of which the method is a member.
316 * @param name The method's name.
317 * @param argtypes The method's argument types.
318 * @param isStatic A flag that indicates whether we call a
319 * static or instance method.
320 */
321 void callMethod(DiagnosticPosition pos,
322 Type site, Name name, List<Type> argtypes,
323 boolean isStatic) {
324 Symbol msym = rs.
325 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null);
326 if (isStatic) items.makeStaticItem(msym).invoke();
327 else items.makeMemberItem(msym, name == names.init).invoke();
328 }
329
330 /** Is the given method definition an access method
331 * resulting from a qualified super? This is signified by an odd
332 * access code.
333 */
334 private boolean isAccessSuper(JCMethodDecl enclMethod) {
335 return
336 (enclMethod.mods.flags & SYNTHETIC) != 0 &&
337 isOddAccessName(enclMethod.name);
338 }
339
340 /** Does given name start with "access$" and end in an odd digit?
341 */
342 private boolean isOddAccessName(Name name) {
343 final String string = name.toString();
344 return
345 string.startsWith(accessDollar) &&
346 (string.charAt(string.length() - 1) & 1) != 0;
347 }
348
349 /* ************************************************************************
350 * Non-local exits
351 *************************************************************************/
352
353 /** Generate code to invoke the finalizer associated with given
354 * environment.
355 * Any calls to finalizers are appended to the environments `cont' chain.
356 * Mark beginning of gap in catch all range for finalizer.
357 */
358 void genFinalizer(Env<GenContext> env) {
359 if (code.isAlive() && env.info.finalize != null)
360 env.info.finalize.gen();
361 }
362
363 /** Generate code to call all finalizers of structures aborted by
364 * a non-local
365 * exit. Return target environment of the non-local exit.
366 * @param target The tree representing the structure that's aborted
367 * @param env The environment current at the non-local exit.
368 */
369 Env<GenContext> unwind(JCTree target, Env<GenContext> env) {
370 Env<GenContext> env1 = env;
371 while (true) {
372 genFinalizer(env1);
373 if (env1.tree == target) break;
374 env1 = env1.next;
375 }
376 return env1;
377 }
378
379 /** Mark end of gap in catch-all range for finalizer.
380 * @param env the environment which might contain the finalizer
381 * (if it does, env.info.gaps != null).
382 */
383 void endFinalizerGap(Env<GenContext> env) {
384 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1)
385 env.info.gaps.append(code.curCP());
386 }
387
388 /** Mark end of all gaps in catch-all ranges for finalizers of environments
389 * lying between, and including to two environments.
390 * @param from the most deeply nested environment to mark
391 * @param to the least deeply nested environment to mark
392 */
393 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) {
394 Env<GenContext> last = null;
395 while (last != to) {
396 endFinalizerGap(from);
397 last = from;
398 from = from.next;
399 }
400 }
401
402 /** Do any of the structures aborted by a non-local exit have
403 * finalizers that require an empty stack?
404 * @param target The tree representing the structure that's aborted
405 * @param env The environment current at the non-local exit.
406 */
407 boolean hasFinally(JCTree target, Env<GenContext> env) {
408 while (env.tree != target) {
409 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer())
410 return true;
411 env = env.next;
412 }
413 return false;
414 }
415
416 /* ************************************************************************
417 * Normalizing class-members.
418 *************************************************************************/
419
420 /** Distribute member initializer code into constructors and {@code <clinit>}
421 * method.
422 * @param defs The list of class member declarations.
423 * @param c The enclosing class.
424 */
425 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) {
426 ListBuffer<JCStatement> initCode = new ListBuffer<>();
427 // only used for value classes
428 ListBuffer<JCStatement> initBlocks = new ListBuffer<>();
429 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>();
430 ListBuffer<JCStatement> clinitCode = new ListBuffer<>();
431 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>();
432 ListBuffer<JCTree> methodDefs = new ListBuffer<>();
433 // Sort definitions into three listbuffers:
434 // - initCode for instance initializers
435 // - clinitCode for class initializers
436 // - methodDefs for method definitions
437 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
438 JCTree def = l.head;
439 switch (def.getTag()) {
440 case BLOCK:
441 JCBlock block = (JCBlock)def;
442 if ((block.flags & STATIC) != 0)
443 clinitCode.append(block);
444 else if ((block.flags & SYNTHETIC) == 0) {
445 if (c.isValueClass()) {
446 initBlocks.append(block);
447 } else {
448 initCode.append(block);
449 }
450 }
451 break;
452 case METHODDEF:
453 methodDefs.append(def);
454 break;
455 case VARDEF:
456 JCVariableDecl vdef = (JCVariableDecl) def;
457 VarSymbol sym = vdef.sym;
458 checkDimension(vdef.pos(), sym.type);
459 if (vdef.init != null) {
460 if ((sym.flags() & STATIC) == 0) {
461 // Always initialize instance variables.
462 JCStatement init = make.at(vdef.pos()).
463 Assignment(sym, vdef.init);
464 initCode.append(init);
465 endPosTable.replaceTree(vdef, init);
466 initTAs.addAll(getAndRemoveNonFieldTAs(sym));
467 } else if (sym.getConstValue() == null) {
468 // Initialize class (static) variables only if
469 // they are not compile-time constants.
470 JCStatement init = make.at(vdef.pos).
471 Assignment(sym, vdef.init);
472 clinitCode.append(init);
473 endPosTable.replaceTree(vdef, init);
474 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym));
475 } else {
476 checkStringConstant(vdef.init.pos(), sym.getConstValue());
477 /* if the init contains a reference to an external class, add it to the
478 * constant's pool
479 */
480 vdef.init.accept(classReferenceVisitor);
481 }
482 }
483 break;
484 default:
485 Assert.error();
486 }
487 }
488 // Insert any instance initializers into all constructors.
489 if (initCode.length() != 0 || initBlocks.length() != 0) {
490 initTAs.addAll(c.getInitTypeAttributes());
491 List<Attribute.TypeCompound> initTAlist = initTAs.toList();
492 for (JCTree t : methodDefs) {
493 normalizeMethod((JCMethodDecl)t, initCode.toList(), initBlocks.toList(), initTAlist);
494 }
495 }
496 // If there are class initializers, create a <clinit> method
497 // that contains them as its body.
498 if (clinitCode.length() != 0) {
499 MethodSymbol clinit = new MethodSymbol(
500 STATIC | (c.flags() & STRICTFP),
501 names.clinit,
502 new MethodType(
503 List.nil(), syms.voidType,
504 List.nil(), syms.methodClass),
505 c);
506 c.members().enter(clinit);
507 List<JCStatement> clinitStats = clinitCode.toList();
508 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
509 block.endpos = TreeInfo.endPos(clinitStats.last());
510 methodDefs.append(make.MethodDef(clinit, block));
511
512 if (!clinitTAs.isEmpty())
513 clinit.appendUniqueTypeAttributes(clinitTAs.toList());
514 if (!c.getClassInitTypeAttributes().isEmpty())
515 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes());
516 }
517 // Return all method definitions.
518 return methodDefs.toList();
519 }
520
521 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) {
522 List<TypeCompound> tas = sym.getRawTypeAttributes();
523 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>();
524 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>();
525 for (TypeCompound ta : tas) {
526 Assert.check(ta.getPosition().type != TargetType.UNKNOWN);
527 if (ta.getPosition().type == TargetType.FIELD) {
528 fieldTAs.add(ta);
529 } else {
530 nonfieldTAs.add(ta);
531 }
532 }
533 sym.setTypeAttributes(fieldTAs.toList());
534 return nonfieldTAs.toList();
535 }
536
537 /** Check a constant value and report if it is a string that is
538 * too large.
539 */
540 private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
541 if (nerrs != 0 || // only complain about a long string once
542 constValue == null ||
543 !(constValue instanceof String str) ||
544 str.length() < PoolWriter.MAX_STRING_LENGTH)
545 return;
546 log.error(pos, Errors.LimitString);
547 nerrs++;
548 }
549
550 /** Insert instance initializer code into constructors prior to the super() call.
551 * @param md The tree potentially representing a
552 * constructor's definition.
553 * @param initCode The list of instance initializer statements.
554 * @param initTAs Type annotations from the initializer expression.
555 */
556 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<JCStatement> initBlocks, List<TypeCompound> initTAs) {
557 if (TreeInfo.isConstructor(md) && TreeInfo.hasConstructorCall(md, names._super)) {
558 // We are seeing a constructor that has a super() call.
559 // Find the super() invocation and append the given initializer code.
560 if (md.sym.owner.isValueClass()) {
561 rewriteInitializersIfNeeded(md, initCode);
562 TreeInfo.mapSuperCalls(md.body, supercall -> make.Block(0, initCode.append(supercall).appendList(initBlocks)));
563 } else {
564 TreeInfo.mapSuperCalls(md.body, supercall -> make.Block(0, initCode.prepend(supercall)));
565 }
566
567 if (md.body.endpos == Position.NOPOS)
568 md.body.endpos = TreeInfo.endPos(md.body.stats.last());
569
570 md.sym.appendUniqueTypeAttributes(initTAs);
571 }
572 }
573
574 void rewriteInitializersIfNeeded(JCMethodDecl md, List<JCStatement> initCode) {
575 if (lower.initializerOuterThis.containsKey(md.sym.owner)) {
576 InitializerVisitor initializerVisitor = new InitializerVisitor(md, lower.initializerOuterThis.get(md.sym.owner));
577 for (JCStatement init : initCode) {
578 initializerVisitor.scan(init);
579 }
580 }
581 }
582
583 class InitializerVisitor extends TreeScanner {
584 JCMethodDecl md;
585 Set<JCExpression> exprSet;
586
587 InitializerVisitor(JCMethodDecl md, Set<JCExpression> exprSet) {
588 this.md = md;
589 this.exprSet = exprSet;
590 }
591
592 @Override
593 public void visitTree(JCTree tree) {}
594
595 @Override
596 public void visitIdent(JCIdent tree) {
597 if (exprSet.contains(tree)) {
598 for (JCVariableDecl param: md.params) {
599 if (param.name == tree.name &&
600 ((param.sym.flags_field & (MANDATED | NOOUTERTHIS)) == (MANDATED | NOOUTERTHIS))) {
601 tree.sym = param.sym;
602 }
603 }
604 }
605 }
606 }
607
608 /* ************************************************************************
609 * Traversal methods
610 *************************************************************************/
611
612 /** Visitor argument: The current environment.
613 */
614 Env<GenContext> env;
615
616 /** Visitor argument: The expected type (prototype).
617 */
618 Type pt;
619
620 /** Visitor result: The item representing the computed value.
621 */
622 Item result;
623
624 /** Visitor method: generate code for a definition, catching and reporting
625 * any completion failures.
626 * @param tree The definition to be visited.
627 * @param env The environment current at the definition.
628 */
629 public void genDef(JCTree tree, Env<GenContext> env) {
630 Env<GenContext> prevEnv = this.env;
631 try {
632 this.env = env;
633 tree.accept(this);
634 } catch (CompletionFailure ex) {
635 chk.completionError(tree.pos(), ex);
636 } finally {
637 this.env = prevEnv;
638 }
639 }
640
641 /** Derived visitor method: check whether CharacterRangeTable
642 * should be emitted, if so, put a new entry into CRTable
643 * and call method to generate bytecode.
644 * If not, just call method to generate bytecode.
645 * @see #genStat(JCTree, Env)
646 *
647 * @param tree The tree to be visited.
648 * @param env The environment to use.
649 * @param crtFlags The CharacterRangeTable flags
650 * indicating type of the entry.
651 */
652 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
653 if (!genCrt) {
654 genStat(tree, env);
655 return;
656 }
657 int startpc = code.curCP();
658 genStat(tree, env);
659 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK;
660 code.crt.put(tree, crtFlags, startpc, code.curCP());
661 }
662
663 /** Derived visitor method: generate code for a statement.
664 */
665 public void genStat(JCTree tree, Env<GenContext> env) {
666 if (code.isAlive()) {
667 code.statBegin(tree.pos);
668 genDef(tree, env);
669 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) {
670 // variables whose declarations are in a switch
671 // can be used even if the decl is unreachable.
672 code.newLocal(((JCVariableDecl) tree).sym);
673 }
674 }
675
676 /** Derived visitor method: check whether CharacterRangeTable
677 * should be emitted, if so, put a new entry into CRTable
678 * and call method to generate bytecode.
679 * If not, just call method to generate bytecode.
680 * @see #genStats(List, Env)
681 *
682 * @param trees The list of trees to be visited.
683 * @param env The environment to use.
684 * @param crtFlags The CharacterRangeTable flags
685 * indicating type of the entry.
686 */
687 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
688 if (!genCrt) {
689 genStats(trees, env);
690 return;
691 }
692 if (trees.length() == 1) { // mark one statement with the flags
693 genStat(trees.head, env, crtFlags | CRT_STATEMENT);
694 } else {
695 int startpc = code.curCP();
696 genStats(trees, env);
697 code.crt.put(trees, crtFlags, startpc, code.curCP());
698 }
699 }
700
701 /** Derived visitor method: generate code for a list of statements.
702 */
703 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) {
704 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
705 genStat(l.head, env, CRT_STATEMENT);
706 }
707
708 /** Derived visitor method: check whether CharacterRangeTable
709 * should be emitted, if so, put a new entry into CRTable
710 * and call method to generate bytecode.
711 * If not, just call method to generate bytecode.
712 * @see #genCond(JCTree,boolean)
713 *
714 * @param tree The tree to be visited.
715 * @param crtFlags The CharacterRangeTable flags
716 * indicating type of the entry.
717 */
718 public CondItem genCond(JCTree tree, int crtFlags) {
719 if (!genCrt) return genCond(tree, false);
720 int startpc = code.curCP();
721 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
722 code.crt.put(tree, crtFlags, startpc, code.curCP());
723 return item;
724 }
725
726 /** Derived visitor method: generate code for a boolean
727 * expression in a control-flow context.
728 * @param _tree The expression to be visited.
729 * @param markBranches The flag to indicate that the condition is
730 * a flow controller so produced conditions
731 * should contain a proper tree to generate
732 * CharacterRangeTable branches for them.
733 */
734 public CondItem genCond(JCTree _tree, boolean markBranches) {
735 JCTree inner_tree = TreeInfo.skipParens(_tree);
736 if (inner_tree.hasTag(CONDEXPR)) {
737 JCConditional tree = (JCConditional)inner_tree;
738 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
739 if (cond.isTrue()) {
740 code.resolve(cond.trueJumps);
741 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
742 if (markBranches) result.tree = tree.truepart;
743 return result;
744 }
745 if (cond.isFalse()) {
746 code.resolve(cond.falseJumps);
747 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
748 if (markBranches) result.tree = tree.falsepart;
749 return result;
750 }
751 Chain secondJumps = cond.jumpFalse();
752 code.resolve(cond.trueJumps);
753 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
754 if (markBranches) first.tree = tree.truepart;
755 Chain falseJumps = first.jumpFalse();
756 code.resolve(first.trueJumps);
757 Chain trueJumps = code.branch(goto_);
758 code.resolve(secondJumps);
759 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
760 CondItem result = items.makeCondItem(second.opcode,
761 Code.mergeChains(trueJumps, second.trueJumps),
762 Code.mergeChains(falseJumps, second.falseJumps));
763 if (markBranches) result.tree = tree.falsepart;
764 return result;
765 } else if (inner_tree.hasTag(SWITCH_EXPRESSION)) {
766 code.resolvePending();
767
768 boolean prevInCondSwitchExpression = inCondSwitchExpression;
769 Chain prevSwitchExpressionTrueChain = switchExpressionTrueChain;
770 Chain prevSwitchExpressionFalseChain = switchExpressionFalseChain;
771 try {
772 inCondSwitchExpression = true;
773 switchExpressionTrueChain = null;
774 switchExpressionFalseChain = null;
775 try {
776 doHandleSwitchExpression((JCSwitchExpression) inner_tree);
777 } catch (CompletionFailure ex) {
778 chk.completionError(_tree.pos(), ex);
779 code.state.stacksize = 1;
780 }
781 CondItem result = items.makeCondItem(goto_,
782 switchExpressionTrueChain,
783 switchExpressionFalseChain);
784 if (markBranches) result.tree = _tree;
785 return result;
786 } finally {
787 inCondSwitchExpression = prevInCondSwitchExpression;
788 switchExpressionTrueChain = prevSwitchExpressionTrueChain;
789 switchExpressionFalseChain = prevSwitchExpressionFalseChain;
790 }
791 } else if (inner_tree.hasTag(LETEXPR) && ((LetExpr) inner_tree).needsCond) {
792 code.resolvePending();
793
794 LetExpr tree = (LetExpr) inner_tree;
795 int limit = code.nextreg;
796 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
797 try {
798 genStats(tree.defs, env);
799 } finally {
800 code.setLetExprStackPos(prevLetExprStart);
801 }
802 CondItem result = genCond(tree.expr, markBranches);
803 code.endScopes(limit);
804 return result;
805 } else {
806 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
807 if (markBranches) result.tree = _tree;
808 return result;
809 }
810 }
811
812 public Code getCode() {
813 return code;
814 }
815
816 public Items getItems() {
817 return items;
818 }
819
820 public Env<AttrContext> getAttrEnv() {
821 return attrEnv;
822 }
823
824 /** Visitor class for expressions which might be constant expressions.
825 * This class is a subset of TreeScanner. Intended to visit trees pruned by
826 * Lower as long as constant expressions looking for references to any
827 * ClassSymbol. Any such reference will be added to the constant pool so
828 * automated tools can detect class dependencies better.
829 */
830 class ClassReferenceVisitor extends JCTree.Visitor {
831
832 @Override
833 public void visitTree(JCTree tree) {}
834
835 @Override
836 public void visitBinary(JCBinary tree) {
837 tree.lhs.accept(this);
838 tree.rhs.accept(this);
839 }
840
841 @Override
842 public void visitSelect(JCFieldAccess tree) {
843 if (tree.selected.type.hasTag(CLASS)) {
844 makeRef(tree.selected.pos(), tree.selected.type);
845 }
846 }
847
848 @Override
849 public void visitIdent(JCIdent tree) {
850 if (tree.sym.owner instanceof ClassSymbol classSymbol) {
851 poolWriter.putClass(classSymbol);
852 }
853 }
854
855 @Override
856 public void visitConditional(JCConditional tree) {
857 tree.cond.accept(this);
858 tree.truepart.accept(this);
859 tree.falsepart.accept(this);
860 }
861
862 @Override
863 public void visitUnary(JCUnary tree) {
864 tree.arg.accept(this);
865 }
866
867 @Override
868 public void visitParens(JCParens tree) {
869 tree.expr.accept(this);
870 }
871
872 @Override
873 public void visitTypeCast(JCTypeCast tree) {
874 tree.expr.accept(this);
875 }
876 }
877
878 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor();
879
880 /** Visitor method: generate code for an expression, catching and reporting
881 * any completion failures.
882 * @param tree The expression to be visited.
883 * @param pt The expression's expected type (proto-type).
884 */
885 public Item genExpr(JCTree tree, Type pt) {
886 if (!code.isAlive()) {
887 return items.makeStackItem(pt);
888 }
889
890 Type prevPt = this.pt;
891 try {
892 if (tree.type.constValue() != null) {
893 // Short circuit any expressions which are constants
894 tree.accept(classReferenceVisitor);
895 checkStringConstant(tree.pos(), tree.type.constValue());
896 Symbol sym = TreeInfo.symbol(tree);
897 if (sym != null && isConstantDynamic(sym)) {
898 result = items.makeDynamicItem(sym);
899 } else {
900 result = items.makeImmediateItem(tree.type, tree.type.constValue());
901 }
902 } else {
903 this.pt = pt;
904 tree.accept(this);
905 }
906 return result.coerce(pt);
907 } catch (CompletionFailure ex) {
908 chk.completionError(tree.pos(), ex);
909 code.state.stacksize = 1;
910 return items.makeStackItem(pt);
911 } finally {
912 this.pt = prevPt;
913 }
914 }
915
916 public boolean isConstantDynamic(Symbol sym) {
917 return sym.kind == VAR &&
918 sym instanceof DynamicVarSymbol dynamicVarSymbol &&
919 dynamicVarSymbol.isDynamic();
920 }
921
922 /** Derived visitor method: generate code for a list of method arguments.
923 * @param trees The argument expressions to be visited.
924 * @param pts The expression's expected types (i.e. the formal parameter
925 * types of the invoked method).
926 */
927 public void genArgs(List<JCExpression> trees, List<Type> pts) {
928 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
929 genExpr(l.head, pts.head).load();
930 pts = pts.tail;
931 }
932 // require lists be of same length
933 Assert.check(pts.isEmpty());
934 }
935
936 /* ************************************************************************
937 * Visitor methods for statements and definitions
938 *************************************************************************/
939
940 /** Thrown when the byte code size exceeds limit.
941 */
942 public static class CodeSizeOverflow extends RuntimeException {
943 private static final long serialVersionUID = 0;
944 public CodeSizeOverflow() {}
945 }
946
947 public void visitMethodDef(JCMethodDecl tree) {
948 // Create a new local environment that points pack at method
949 // definition.
950 Env<GenContext> localEnv = env.dup(tree);
951 localEnv.enclMethod = tree;
952 // The expected type of every return statement in this method
953 // is the method's return type.
954 this.pt = tree.sym.erasure(types).getReturnType();
955
956 checkDimension(tree.pos(), tree.sym.erasure(types));
957 genMethod(tree, localEnv, false);
958 }
959 //where
960 /** Generate code for a method.
961 * @param tree The tree representing the method definition.
962 * @param env The environment current for the method body.
963 * @param fatcode A flag that indicates whether all jumps are
964 * within 32K. We first invoke this method under
965 * the assumption that fatcode == false, i.e. all
966 * jumps are within 32K. If this fails, fatcode
967 * is set to true and we try again.
968 */
969 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
970 MethodSymbol meth = tree.sym;
971 int extras = 0;
972 // Count up extra parameters
973 if (meth.isConstructor()) {
974 extras++;
975 if (meth.enclClass().isInner() &&
976 !meth.enclClass().isStatic()) {
977 extras++;
978 }
979 } else if ((tree.mods.flags & STATIC) == 0) {
980 extras++;
981 }
982 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
983 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
984 ClassFile.MAX_PARAMETERS) {
985 log.error(tree.pos(), Errors.LimitParameters);
986 nerrs++;
987 }
988
989 else if (tree.body != null) {
990 // Create a new code structure and initialize it.
991 int startpcCrt = initCode(tree, env, fatcode);
992
993 try {
994 genStat(tree.body, env);
995 } catch (CodeSizeOverflow e) {
996 // Failed due to code limit, try again with jsr/ret
997 startpcCrt = initCode(tree, env, fatcode);
998 genStat(tree.body, env);
999 }
1000
1001 if (code.state.stacksize != 0) {
1002 log.error(tree.body.pos(), Errors.StackSimError(tree.sym));
1003 throw new AssertionError();
1004 }
1005
1006 // If last statement could complete normally, insert a
1007 // return at the end.
1008 if (code.isAlive()) {
1009 code.statBegin(TreeInfo.endPos(tree.body));
1010 if (env.enclMethod == null ||
1011 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
1012 code.emitop0(return_);
1013 } else {
1014 // sometime dead code seems alive (4415991);
1015 // generate a small loop instead
1016 int startpc = code.entryPoint();
1017 CondItem c = items.makeCondItem(goto_);
1018 code.resolve(c.jumpTrue(), startpc);
1019 }
1020 }
1021 if (genCrt)
1022 code.crt.put(tree.body,
1023 CRT_BLOCK,
1024 startpcCrt,
1025 code.curCP());
1026
1027 code.endScopes(0);
1028
1029 // If we exceeded limits, panic
1030 if (code.checkLimits(tree.pos(), log)) {
1031 nerrs++;
1032 return;
1033 }
1034
1035 // If we generated short code but got a long jump, do it again
1036 // with fatCode = true.
1037 if (!fatcode && code.fatcode) genMethod(tree, env, true);
1038
1039 // Clean up
1040 if(stackMap == StackMapFormat.JSR202) {
1041 code.lastFrame = null;
1042 code.frameBeforeLast = null;
1043 }
1044
1045 // Compress exception table
1046 code.compressCatchTable();
1047
1048 // Fill in type annotation positions for exception parameters
1049 code.fillExceptionParameterPositions();
1050 }
1051 }
1052
1053 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1054 MethodSymbol meth = tree.sym;
1055
1056 // Create a new code structure.
1057 meth.code = code = new Code(meth,
1058 fatcode,
1059 lineDebugInfo ? toplevel.lineMap : null,
1060 varDebugInfo,
1061 stackMap,
1062 debugCode,
1063 genCrt ? new CRTable(tree, env.toplevel.endPositions)
1064 : null,
1065 syms,
1066 types,
1067 poolWriter);
1068 items = new Items(poolWriter, code, syms, types);
1069 if (code.debugCode) {
1070 System.err.println(meth + " for body " + tree);
1071 }
1072
1073 // If method is not static, create a new local variable address
1074 // for `this'.
1075 if ((tree.mods.flags & STATIC) == 0) {
1076 Type selfType = meth.owner.type;
1077 if (meth.isConstructor() && selfType != syms.objectType)
1078 selfType = UninitializedType.uninitializedThis(selfType);
1079 code.setDefined(
1080 code.newLocal(
1081 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1082 }
1083
1084 // Mark all parameters as defined from the beginning of
1085 // the method.
1086 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1087 checkDimension(l.head.pos(), l.head.sym.type);
1088 code.setDefined(code.newLocal(l.head.sym));
1089 }
1090
1091 // Get ready to generate code for method body.
1092 int startpcCrt = genCrt ? code.curCP() : 0;
1093 code.entryPoint();
1094
1095 // Suppress initial stackmap
1096 code.pendingStackMap = false;
1097
1098 return startpcCrt;
1099 }
1100
1101 public void visitVarDef(JCVariableDecl tree) {
1102 VarSymbol v = tree.sym;
1103 if (tree.init != null) {
1104 checkStringConstant(tree.init.pos(), v.getConstValue());
1105 if (v.getConstValue() == null || varDebugInfo) {
1106 Assert.check(code.isStatementStart());
1107 code.newLocal(v);
1108 genExpr(tree.init, v.erasure(types)).load();
1109 items.makeLocalItem(v).store();
1110 Assert.check(code.isStatementStart());
1111 }
1112 } else {
1113 code.newLocal(v);
1114 }
1115 checkDimension(tree.pos(), v.type);
1116 }
1117
1118 public void visitSkip(JCSkip tree) {
1119 }
1120
1121 public void visitBlock(JCBlock tree) {
1122 if (tree.patternMatchingCatch != null) {
1123 Set<JCMethodInvocation> prevInvocationsWithPatternMatchingCatch = invocationsWithPatternMatchingCatch;
1124 ListBuffer<int[]> prevRanges = patternMatchingInvocationRanges;
1125 State startState = code.state.dup();
1126 try {
1127 invocationsWithPatternMatchingCatch = tree.patternMatchingCatch.calls2Handle();
1128 patternMatchingInvocationRanges = new ListBuffer<>();
1129 doVisitBlock(tree);
1130 } finally {
1131 Chain skipCatch = code.branch(goto_);
1132 JCCatch handler = tree.patternMatchingCatch.handler();
1133 code.entryPoint(startState, handler.param.sym.type);
1134 genPatternMatchingCatch(handler, env, patternMatchingInvocationRanges.toList());
1135 code.resolve(skipCatch);
1136 invocationsWithPatternMatchingCatch = prevInvocationsWithPatternMatchingCatch;
1137 patternMatchingInvocationRanges = prevRanges;
1138 }
1139 } else {
1140 doVisitBlock(tree);
1141 }
1142 }
1143
1144 private void doVisitBlock(JCBlock tree) {
1145 int limit = code.nextreg;
1146 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1147 genStats(tree.stats, localEnv);
1148 // End the scope of all block-local variables in variable info.
1149 if (!env.tree.hasTag(METHODDEF)) {
1150 code.statBegin(tree.endpos);
1151 code.endScopes(limit);
1152 code.pendingStatPos = Position.NOPOS;
1153 }
1154 }
1155
1156 public void visitDoLoop(JCDoWhileLoop tree) {
1157 genLoop(tree, tree.body, tree.cond, List.nil(), false);
1158 }
1159
1160 public void visitWhileLoop(JCWhileLoop tree) {
1161 genLoop(tree, tree.body, tree.cond, List.nil(), true);
1162 }
1163
1164 public void visitForLoop(JCForLoop tree) {
1165 int limit = code.nextreg;
1166 genStats(tree.init, env);
1167 genLoop(tree, tree.body, tree.cond, tree.step, true);
1168 code.endScopes(limit);
1169 }
1170 //where
1171 /** Generate code for a loop.
1172 * @param loop The tree representing the loop.
1173 * @param body The loop's body.
1174 * @param cond The loop's controlling condition.
1175 * @param step "Step" statements to be inserted at end of
1176 * each iteration.
1177 * @param testFirst True if the loop test belongs before the body.
1178 */
1179 private void genLoop(JCStatement loop,
1180 JCStatement body,
1181 JCExpression cond,
1182 List<JCExpressionStatement> step,
1183 boolean testFirst) {
1184 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1185 int startpc = code.entryPoint();
1186 if (testFirst) { //while or for loop
1187 CondItem c;
1188 if (cond != null) {
1189 code.statBegin(cond.pos);
1190 Assert.check(code.isStatementStart());
1191 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1192 } else {
1193 c = items.makeCondItem(goto_);
1194 }
1195 Chain loopDone = c.jumpFalse();
1196 code.resolve(c.trueJumps);
1197 Assert.check(code.isStatementStart());
1198 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1199 code.resolve(loopEnv.info.cont);
1200 genStats(step, loopEnv);
1201 code.resolve(code.branch(goto_), startpc);
1202 code.resolve(loopDone);
1203 } else {
1204 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1205 code.resolve(loopEnv.info.cont);
1206 genStats(step, loopEnv);
1207 if (code.isAlive()) {
1208 CondItem c;
1209 if (cond != null) {
1210 code.statBegin(cond.pos);
1211 Assert.check(code.isStatementStart());
1212 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1213 } else {
1214 c = items.makeCondItem(goto_);
1215 }
1216 code.resolve(c.jumpTrue(), startpc);
1217 Assert.check(code.isStatementStart());
1218 code.resolve(c.falseJumps);
1219 }
1220 }
1221 Chain exit = loopEnv.info.exit;
1222 if (exit != null) {
1223 code.resolve(exit);
1224 exit.state.defined.excludeFrom(code.nextreg);
1225 }
1226 }
1227
1228 public void visitForeachLoop(JCEnhancedForLoop tree) {
1229 throw new AssertionError(); // should have been removed by Lower.
1230 }
1231
1232 public void visitLabelled(JCLabeledStatement tree) {
1233 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1234 genStat(tree.body, localEnv, CRT_STATEMENT);
1235 Chain exit = localEnv.info.exit;
1236 if (exit != null) {
1237 code.resolve(exit);
1238 exit.state.defined.excludeFrom(code.nextreg);
1239 }
1240 }
1241
1242 public void visitSwitch(JCSwitch tree) {
1243 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1244 }
1245
1246 @Override
1247 public void visitSwitchExpression(JCSwitchExpression tree) {
1248 code.resolvePending();
1249 boolean prevInCondSwitchExpression = inCondSwitchExpression;
1250 try {
1251 inCondSwitchExpression = false;
1252 doHandleSwitchExpression(tree);
1253 } finally {
1254 inCondSwitchExpression = prevInCondSwitchExpression;
1255 }
1256 result = items.makeStackItem(pt);
1257 }
1258
1259 private void doHandleSwitchExpression(JCSwitchExpression tree) {
1260 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
1261 LocalItem prevSwitchResult = switchResult;
1262 int limit = code.nextreg;
1263 try {
1264 stackBeforeSwitchExpression = List.nil();
1265 switchResult = null;
1266 if (hasTry(tree)) {
1267 //if the switch expression contains try-catch, the catch handlers need to have
1268 //an empty stack. So stash whole stack to local variables, and restore it before
1269 //breaks:
1270 while (code.state.stacksize > 0) {
1271 Type type = code.state.peek();
1272 Name varName = names.fromString(target.syntheticNameChar() +
1273 "stack" +
1274 target.syntheticNameChar() +
1275 tree.pos +
1276 target.syntheticNameChar() +
1277 code.state.stacksize);
1278 VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type,
1279 this.env.enclMethod.sym);
1280 LocalItem item = items.new LocalItem(type, code.newLocal(var));
1281 stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item);
1282 item.store();
1283 }
1284 switchResult = makeTemp(tree.type);
1285 }
1286 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
1287 try {
1288 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1289 } finally {
1290 code.setLetExprStackPos(prevLetExprStart);
1291 }
1292 } finally {
1293 stackBeforeSwitchExpression = prevStackBeforeSwitchExpression;
1294 switchResult = prevSwitchResult;
1295 code.endScopes(limit);
1296 }
1297 }
1298 //where:
1299 private boolean hasTry(JCSwitchExpression tree) {
1300 class HasTryScanner extends TreeScanner {
1301 private boolean hasTry;
1302
1303 @Override
1304 public void visitTry(JCTry tree) {
1305 hasTry = true;
1306 }
1307
1308 @Override
1309 public void visitSynchronized(JCSynchronized tree) {
1310 hasTry = true;
1311 }
1312
1313 @Override
1314 public void visitClassDef(JCClassDecl tree) {
1315 }
1316
1317 @Override
1318 public void visitLambda(JCLambda tree) {
1319 }
1320 };
1321
1322 HasTryScanner hasTryScanner = new HasTryScanner();
1323
1324 hasTryScanner.scan(tree);
1325 return hasTryScanner.hasTry;
1326 }
1327
1328 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases,
1329 boolean patternSwitch) {
1330 int limit = code.nextreg;
1331 Assert.check(!selector.type.hasTag(CLASS));
1332 int switchStart = patternSwitch ? code.entryPoint() : -1;
1333 int startpcCrt = genCrt ? code.curCP() : 0;
1334 Assert.check(code.isStatementStart());
1335 Item sel = genExpr(selector, syms.intType);
1336 if (cases.isEmpty()) {
1337 // We are seeing: switch <sel> {}
1338 sel.load().drop();
1339 if (genCrt)
1340 code.crt.put(TreeInfo.skipParens(selector),
1341 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1342 } else {
1343 // We are seeing a nonempty switch.
1344 sel.load();
1345 if (genCrt)
1346 code.crt.put(TreeInfo.skipParens(selector),
1347 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1348 Env<GenContext> switchEnv = env.dup(swtch, new GenContext());
1349 switchEnv.info.isSwitch = true;
1350
1351 // Compute number of labels and minimum and maximum label values.
1352 // For each case, store its label in an array.
1353 int lo = Integer.MAX_VALUE; // minimum label.
1354 int hi = Integer.MIN_VALUE; // maximum label.
1355 int nlabels = 0; // number of labels.
1356
1357 int[] labels = new int[cases.length()]; // the label array.
1358 int defaultIndex = -1; // the index of the default clause.
1359
1360 List<JCCase> l = cases;
1361 for (int i = 0; i < labels.length; i++) {
1362 if (l.head.labels.head instanceof JCConstantCaseLabel constLabel) {
1363 Assert.check(l.head.labels.size() == 1);
1364 int val = ((Number) constLabel.expr.type.constValue()).intValue();
1365 labels[i] = val;
1366 if (val < lo) lo = val;
1367 if (hi < val) hi = val;
1368 nlabels++;
1369 } else {
1370 Assert.check(defaultIndex == -1);
1371 defaultIndex = i;
1372 }
1373 l = l.tail;
1374 }
1375
1376 // Determine whether to issue a tableswitch or a lookupswitch
1377 // instruction.
1378 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1379 long table_time_cost = 3; // comparisons
1380 long lookup_space_cost = 3 + 2 * (long) nlabels;
1381 long lookup_time_cost = nlabels;
1382 int opcode =
1383 nlabels > 0 &&
1384 table_space_cost + 3 * table_time_cost <=
1385 lookup_space_cost + 3 * lookup_time_cost
1386 ?
1387 tableswitch : lookupswitch;
1388
1389 int startpc = code.curCP(); // the position of the selector operation
1390 code.emitop0(opcode);
1391 code.align(4);
1392 int tableBase = code.curCP(); // the start of the jump table
1393 int[] offsets = null; // a table of offsets for a lookupswitch
1394 code.emit4(-1); // leave space for default offset
1395 if (opcode == tableswitch) {
1396 code.emit4(lo); // minimum label
1397 code.emit4(hi); // maximum label
1398 for (long i = lo; i <= hi; i++) { // leave space for jump table
1399 code.emit4(-1);
1400 }
1401 } else {
1402 code.emit4(nlabels); // number of labels
1403 for (int i = 0; i < nlabels; i++) {
1404 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1405 }
1406 offsets = new int[labels.length];
1407 }
1408 Code.State stateSwitch = code.state.dup();
1409 code.markDead();
1410
1411 // For each case do:
1412 l = cases;
1413 for (int i = 0; i < labels.length; i++) {
1414 JCCase c = l.head;
1415 l = l.tail;
1416
1417 int pc = code.entryPoint(stateSwitch);
1418 // Insert offset directly into code or else into the
1419 // offsets table.
1420 if (i != defaultIndex) {
1421 if (opcode == tableswitch) {
1422 code.put4(
1423 tableBase + 4 * (labels[i] - lo + 3),
1424 pc - startpc);
1425 } else {
1426 offsets[i] = pc - startpc;
1427 }
1428 } else {
1429 code.put4(tableBase, pc - startpc);
1430 }
1431
1432 // Generate code for the statements in this case.
1433 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1434 }
1435
1436 if (switchEnv.info.cont != null) {
1437 Assert.check(patternSwitch);
1438 code.resolve(switchEnv.info.cont, switchStart);
1439 }
1440
1441 // Resolve all breaks.
1442 Chain exit = switchEnv.info.exit;
1443 if (exit != null) {
1444 code.resolve(exit);
1445 exit.state.defined.excludeFrom(limit);
1446 }
1447
1448 // If we have not set the default offset, we do so now.
1449 if (code.get4(tableBase) == -1) {
1450 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1451 }
1452
1453 if (opcode == tableswitch) {
1454 // Let any unfilled slots point to the default case.
1455 int defaultOffset = code.get4(tableBase);
1456 for (long i = lo; i <= hi; i++) {
1457 int t = (int)(tableBase + 4 * (i - lo + 3));
1458 if (code.get4(t) == -1)
1459 code.put4(t, defaultOffset);
1460 }
1461 } else {
1462 // Sort non-default offsets and copy into lookup table.
1463 if (defaultIndex >= 0)
1464 for (int i = defaultIndex; i < labels.length - 1; i++) {
1465 labels[i] = labels[i+1];
1466 offsets[i] = offsets[i+1];
1467 }
1468 if (nlabels > 0)
1469 qsort2(labels, offsets, 0, nlabels - 1);
1470 for (int i = 0; i < nlabels; i++) {
1471 int caseidx = tableBase + 8 * (i + 1);
1472 code.put4(caseidx, labels[i]);
1473 code.put4(caseidx + 4, offsets[i]);
1474 }
1475 }
1476
1477 if (swtch instanceof JCSwitchExpression) {
1478 // Emit line position for the end of a switch expression
1479 code.statBegin(TreeInfo.endPos(swtch));
1480 }
1481 }
1482 code.endScopes(limit);
1483 }
1484 //where
1485 /** Sort (int) arrays of keys and values
1486 */
1487 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1488 int i = lo;
1489 int j = hi;
1490 int pivot = keys[(i+j)/2];
1491 do {
1492 while (keys[i] < pivot) i++;
1493 while (pivot < keys[j]) j--;
1494 if (i <= j) {
1495 int temp1 = keys[i];
1496 keys[i] = keys[j];
1497 keys[j] = temp1;
1498 int temp2 = values[i];
1499 values[i] = values[j];
1500 values[j] = temp2;
1501 i++;
1502 j--;
1503 }
1504 } while (i <= j);
1505 if (lo < j) qsort2(keys, values, lo, j);
1506 if (i < hi) qsort2(keys, values, i, hi);
1507 }
1508
1509 public void visitSynchronized(JCSynchronized tree) {
1510 int limit = code.nextreg;
1511 // Generate code to evaluate lock and save in temporary variable.
1512 final LocalItem lockVar = makeTemp(syms.objectType);
1513 Assert.check(code.isStatementStart());
1514 genExpr(tree.lock, tree.lock.type).load().duplicate();
1515 lockVar.store();
1516
1517 // Generate code to enter monitor.
1518 code.emitop0(monitorenter);
1519 code.state.lock(lockVar.reg);
1520
1521 // Generate code for a try statement with given body, no catch clauses
1522 // in a new environment with the "exit-monitor" operation as finalizer.
1523 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1524 syncEnv.info.finalize = new GenFinalizer() {
1525 void gen() {
1526 genLast();
1527 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1528 syncEnv.info.gaps.append(code.curCP());
1529 }
1530 void genLast() {
1531 if (code.isAlive()) {
1532 lockVar.load();
1533 code.emitop0(monitorexit);
1534 code.state.unlock(lockVar.reg);
1535 }
1536 }
1537 };
1538 syncEnv.info.gaps = new ListBuffer<>();
1539 genTry(tree.body, List.nil(), syncEnv);
1540 code.endScopes(limit);
1541 }
1542
1543 public void visitTry(final JCTry tree) {
1544 // Generate code for a try statement with given body and catch clauses,
1545 // in a new environment which calls the finally block if there is one.
1546 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1547 final Env<GenContext> oldEnv = env;
1548 tryEnv.info.finalize = new GenFinalizer() {
1549 void gen() {
1550 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1551 tryEnv.info.gaps.append(code.curCP());
1552 genLast();
1553 }
1554 void genLast() {
1555 if (tree.finalizer != null)
1556 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1557 }
1558 boolean hasFinalizer() {
1559 return tree.finalizer != null;
1560 }
1561
1562 @Override
1563 void afterBody() {
1564 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1565 //for body-only finally, remove the GenFinalizer after try body
1566 //so that the finally is not generated to catch bodies:
1567 tryEnv.info.finalize = null;
1568 }
1569 }
1570
1571 };
1572 tryEnv.info.gaps = new ListBuffer<>();
1573 genTry(tree.body, tree.catchers, tryEnv);
1574 }
1575 //where
1576 /** Generate code for a try or synchronized statement
1577 * @param body The body of the try or synchronized statement.
1578 * @param catchers The list of catch clauses.
1579 * @param env The current environment of the body.
1580 */
1581 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1582 int limit = code.nextreg;
1583 int startpc = code.curCP();
1584 Code.State stateTry = code.state.dup();
1585 genStat(body, env, CRT_BLOCK);
1586 int endpc = code.curCP();
1587 List<Integer> gaps = env.info.gaps.toList();
1588 code.statBegin(TreeInfo.endPos(body));
1589 genFinalizer(env);
1590 code.statBegin(TreeInfo.endPos(env.tree));
1591 Chain exitChain;
1592 boolean actualTry = env.tree.hasTag(TRY);
1593 if (startpc == endpc && actualTry) {
1594 exitChain = code.branch(dontgoto);
1595 } else {
1596 exitChain = code.branch(goto_);
1597 }
1598 endFinalizerGap(env);
1599 env.info.finalize.afterBody();
1600 boolean hasFinalizer =
1601 env.info.finalize != null &&
1602 env.info.finalize.hasFinalizer();
1603 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1604 // start off with exception on stack
1605 code.entryPoint(stateTry, l.head.param.sym.type);
1606 genCatch(l.head, env, startpc, endpc, gaps);
1607 genFinalizer(env);
1608 if (hasFinalizer || l.tail.nonEmpty()) {
1609 code.statBegin(TreeInfo.endPos(env.tree));
1610 exitChain = Code.mergeChains(exitChain,
1611 code.branch(goto_));
1612 }
1613 endFinalizerGap(env);
1614 }
1615 if (hasFinalizer && (startpc != endpc || !actualTry)) {
1616 // Create a new register segment to avoid allocating
1617 // the same variables in finalizers and other statements.
1618 code.newRegSegment();
1619
1620 // Add a catch-all clause.
1621
1622 // start off with exception on stack
1623 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1624
1625 // Register all exception ranges for catch all clause.
1626 // The range of the catch all clause is from the beginning
1627 // of the try or synchronized block until the present
1628 // code pointer excluding all gaps in the current
1629 // environment's GenContext.
1630 int startseg = startpc;
1631 while (env.info.gaps.nonEmpty()) {
1632 int endseg = env.info.gaps.next().intValue();
1633 registerCatch(body.pos(), startseg, endseg,
1634 catchallpc, 0);
1635 startseg = env.info.gaps.next().intValue();
1636 }
1637 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1638 code.markStatBegin();
1639
1640 Item excVar = makeTemp(syms.throwableType);
1641 excVar.store();
1642 genFinalizer(env);
1643 code.resolvePending();
1644 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1645 code.markStatBegin();
1646
1647 excVar.load();
1648 registerCatch(body.pos(), startseg,
1649 env.info.gaps.next().intValue(),
1650 catchallpc, 0);
1651 code.emitop0(athrow);
1652 code.markDead();
1653
1654 // If there are jsr's to this finalizer, ...
1655 if (env.info.cont != null) {
1656 // Resolve all jsr's.
1657 code.resolve(env.info.cont);
1658
1659 // Mark statement line number
1660 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1661 code.markStatBegin();
1662
1663 // Save return address.
1664 LocalItem retVar = makeTemp(syms.throwableType);
1665 retVar.store();
1666
1667 // Generate finalizer code.
1668 env.info.finalize.genLast();
1669
1670 // Return.
1671 code.emitop1w(ret, retVar.reg);
1672 code.markDead();
1673 }
1674 }
1675 // Resolve all breaks.
1676 code.resolve(exitChain);
1677
1678 code.endScopes(limit);
1679 }
1680
1681 /** Generate code for a catch clause.
1682 * @param tree The catch clause.
1683 * @param env The environment current in the enclosing try.
1684 * @param startpc Start pc of try-block.
1685 * @param endpc End pc of try-block.
1686 */
1687 void genCatch(JCCatch tree,
1688 Env<GenContext> env,
1689 int startpc, int endpc,
1690 List<Integer> gaps) {
1691 if (startpc != endpc) {
1692 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs
1693 = catchTypesWithAnnotations(tree);
1694 while (gaps.nonEmpty()) {
1695 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1696 JCExpression subCatch = subCatch1.snd;
1697 int catchType = makeRef(tree.pos(), subCatch.type);
1698 int end = gaps.head.intValue();
1699 registerCatch(tree.pos(),
1700 startpc, end, code.curCP(),
1701 catchType);
1702 for (Attribute.TypeCompound tc : subCatch1.fst) {
1703 tc.position.setCatchInfo(catchType, startpc);
1704 }
1705 }
1706 gaps = gaps.tail;
1707 startpc = gaps.head.intValue();
1708 gaps = gaps.tail;
1709 }
1710 if (startpc < endpc) {
1711 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1712 JCExpression subCatch = subCatch1.snd;
1713 int catchType = makeRef(tree.pos(), subCatch.type);
1714 registerCatch(tree.pos(),
1715 startpc, endpc, code.curCP(),
1716 catchType);
1717 for (Attribute.TypeCompound tc : subCatch1.fst) {
1718 tc.position.setCatchInfo(catchType, startpc);
1719 }
1720 }
1721 }
1722 genCatchBlock(tree, env);
1723 }
1724 }
1725 void genPatternMatchingCatch(JCCatch tree,
1726 Env<GenContext> env,
1727 List<int[]> ranges) {
1728 for (int[] range : ranges) {
1729 JCExpression subCatch = tree.param.vartype;
1730 int catchType = makeRef(tree.pos(), subCatch.type);
1731 registerCatch(tree.pos(),
1732 range[0], range[1], code.curCP(),
1733 catchType);
1734 }
1735 genCatchBlock(tree, env);
1736 }
1737 void genCatchBlock(JCCatch tree, Env<GenContext> env) {
1738 VarSymbol exparam = tree.param.sym;
1739 code.statBegin(tree.pos);
1740 code.markStatBegin();
1741 int limit = code.nextreg;
1742 code.newLocal(exparam);
1743 items.makeLocalItem(exparam).store();
1744 code.statBegin(TreeInfo.firstStatPos(tree.body));
1745 genStat(tree.body, env, CRT_BLOCK);
1746 code.endScopes(limit);
1747 code.statBegin(TreeInfo.endPos(tree.body));
1748 }
1749 // where
1750 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) {
1751 return TreeInfo.isMultiCatch(tree) ?
1752 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) :
1753 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype));
1754 }
1755 // where
1756 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) {
1757 List<JCExpression> alts = tree.alternatives;
1758 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head));
1759 alts = alts.tail;
1760
1761 while(alts != null && alts.head != null) {
1762 JCExpression alt = alts.head;
1763 if (alt instanceof JCAnnotatedType annotatedType) {
1764 res = res.prepend(new Pair<>(annotate.fromAnnotations(annotatedType.annotations), alt));
1765 } else {
1766 res = res.prepend(new Pair<>(List.nil(), alt));
1767 }
1768 alts = alts.tail;
1769 }
1770 return res.reverse();
1771 }
1772
1773 /** Register a catch clause in the "Exceptions" code-attribute.
1774 */
1775 void registerCatch(DiagnosticPosition pos,
1776 int startpc, int endpc,
1777 int handler_pc, int catch_type) {
1778 char startpc1 = (char)startpc;
1779 char endpc1 = (char)endpc;
1780 char handler_pc1 = (char)handler_pc;
1781 if (startpc1 == startpc &&
1782 endpc1 == endpc &&
1783 handler_pc1 == handler_pc) {
1784 code.addCatch(startpc1, endpc1, handler_pc1,
1785 (char)catch_type);
1786 } else {
1787 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1788 nerrs++;
1789 }
1790 }
1791
1792 public void visitIf(JCIf tree) {
1793 int limit = code.nextreg;
1794 Chain thenExit = null;
1795 Assert.check(code.isStatementStart());
1796 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1797 CRT_FLOW_CONTROLLER);
1798 Chain elseChain = c.jumpFalse();
1799 Assert.check(code.isStatementStart());
1800 if (!c.isFalse()) {
1801 code.resolve(c.trueJumps);
1802 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1803 thenExit = code.branch(goto_);
1804 }
1805 if (elseChain != null) {
1806 code.resolve(elseChain);
1807 if (tree.elsepart != null) {
1808 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1809 }
1810 }
1811 code.resolve(thenExit);
1812 code.endScopes(limit);
1813 Assert.check(code.isStatementStart());
1814 }
1815
1816 public void visitExec(JCExpressionStatement tree) {
1817 // Optimize x++ to ++x and x-- to --x.
1818 JCExpression e = tree.expr;
1819 switch (e.getTag()) {
1820 case POSTINC:
1821 ((JCUnary) e).setTag(PREINC);
1822 break;
1823 case POSTDEC:
1824 ((JCUnary) e).setTag(PREDEC);
1825 break;
1826 }
1827 Assert.check(code.isStatementStart());
1828 genExpr(tree.expr, tree.expr.type).drop();
1829 Assert.check(code.isStatementStart());
1830 }
1831
1832 public void visitBreak(JCBreak tree) {
1833 Assert.check(code.isStatementStart());
1834 final Env<GenContext> targetEnv = unwindBreak(tree.target);
1835 targetEnv.info.addExit(code.branch(goto_));
1836 endFinalizerGaps(env, targetEnv);
1837 }
1838
1839 public void visitYield(JCYield tree) {
1840 Assert.check(code.isStatementStart());
1841 final Env<GenContext> targetEnv;
1842 if (inCondSwitchExpression) {
1843 CondItem value = genCond(tree.value, CRT_FLOW_TARGET);
1844 Chain falseJumps = value.jumpFalse();
1845
1846 code.resolve(value.trueJumps);
1847 Env<GenContext> localEnv = unwindBreak(tree.target);
1848 reloadStackBeforeSwitchExpr();
1849 Chain trueJumps = code.branch(goto_);
1850
1851 endFinalizerGaps(env, localEnv);
1852
1853 code.resolve(falseJumps);
1854 targetEnv = unwindBreak(tree.target);
1855 reloadStackBeforeSwitchExpr();
1856 falseJumps = code.branch(goto_);
1857
1858 if (switchExpressionTrueChain == null) {
1859 switchExpressionTrueChain = trueJumps;
1860 } else {
1861 switchExpressionTrueChain =
1862 Code.mergeChains(switchExpressionTrueChain, trueJumps);
1863 }
1864 if (switchExpressionFalseChain == null) {
1865 switchExpressionFalseChain = falseJumps;
1866 } else {
1867 switchExpressionFalseChain =
1868 Code.mergeChains(switchExpressionFalseChain, falseJumps);
1869 }
1870 } else {
1871 genExpr(tree.value, pt).load();
1872 if (switchResult != null)
1873 switchResult.store();
1874
1875 targetEnv = unwindBreak(tree.target);
1876
1877 if (code.isAlive()) {
1878 reloadStackBeforeSwitchExpr();
1879 if (switchResult != null)
1880 switchResult.load();
1881
1882 code.state.forceStackTop(tree.target.type);
1883 targetEnv.info.addExit(code.branch(goto_));
1884 code.markDead();
1885 }
1886 }
1887 endFinalizerGaps(env, targetEnv);
1888 }
1889 //where:
1890 /** As side-effect, might mark code as dead disabling any further emission.
1891 */
1892 private Env<GenContext> unwindBreak(JCTree target) {
1893 int tmpPos = code.pendingStatPos;
1894 Env<GenContext> targetEnv = unwind(target, env);
1895 code.pendingStatPos = tmpPos;
1896 return targetEnv;
1897 }
1898
1899 private void reloadStackBeforeSwitchExpr() {
1900 for (LocalItem li : stackBeforeSwitchExpression)
1901 li.load();
1902 }
1903
1904 public void visitContinue(JCContinue tree) {
1905 int tmpPos = code.pendingStatPos;
1906 Env<GenContext> targetEnv = unwind(tree.target, env);
1907 code.pendingStatPos = tmpPos;
1908 Assert.check(code.isStatementStart());
1909 targetEnv.info.addCont(code.branch(goto_));
1910 endFinalizerGaps(env, targetEnv);
1911 }
1912
1913 public void visitReturn(JCReturn tree) {
1914 int limit = code.nextreg;
1915 final Env<GenContext> targetEnv;
1916
1917 /* Save and then restore the location of the return in case a finally
1918 * is expanded (with unwind()) in the middle of our bytecodes.
1919 */
1920 int tmpPos = code.pendingStatPos;
1921 if (tree.expr != null) {
1922 Assert.check(code.isStatementStart());
1923 Item r = genExpr(tree.expr, pt).load();
1924 if (hasFinally(env.enclMethod, env)) {
1925 r = makeTemp(pt);
1926 r.store();
1927 }
1928 targetEnv = unwind(env.enclMethod, env);
1929 code.pendingStatPos = tmpPos;
1930 r.load();
1931 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
1932 } else {
1933 targetEnv = unwind(env.enclMethod, env);
1934 code.pendingStatPos = tmpPos;
1935 code.emitop0(return_);
1936 }
1937 endFinalizerGaps(env, targetEnv);
1938 code.endScopes(limit);
1939 }
1940
1941 public void visitThrow(JCThrow tree) {
1942 Assert.check(code.isStatementStart());
1943 genExpr(tree.expr, tree.expr.type).load();
1944 code.emitop0(athrow);
1945 Assert.check(code.isStatementStart());
1946 }
1947
1948 /* ************************************************************************
1949 * Visitor methods for expressions
1950 *************************************************************************/
1951
1952 public void visitApply(JCMethodInvocation tree) {
1953 setTypeAnnotationPositions(tree.pos);
1954 // Generate code for method.
1955 Item m = genExpr(tree.meth, methodType);
1956 // Generate code for all arguments, where the expected types are
1957 // the parameters of the method's external type (that is, any implicit
1958 // outer instance of a super(...) call appears as first parameter).
1959 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
1960 genArgs(tree.args,
1961 msym.externalType(types).getParameterTypes());
1962 if (!msym.isDynamic()) {
1963 code.statBegin(tree.pos);
1964 }
1965 if (invocationsWithPatternMatchingCatch.contains(tree)) {
1966 int start = code.curCP();
1967 result = m.invoke();
1968 patternMatchingInvocationRanges.add(new int[] {start, code.curCP()});
1969 } else {
1970 result = m.invoke();
1971 }
1972 }
1973
1974 public void visitConditional(JCConditional tree) {
1975 Chain thenExit = null;
1976 code.statBegin(tree.cond.pos);
1977 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
1978 Chain elseChain = c.jumpFalse();
1979 if (!c.isFalse()) {
1980 code.resolve(c.trueJumps);
1981 int startpc = genCrt ? code.curCP() : 0;
1982 code.statBegin(tree.truepart.pos);
1983 genExpr(tree.truepart, pt).load();
1984 code.state.forceStackTop(tree.type);
1985 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
1986 startpc, code.curCP());
1987 thenExit = code.branch(goto_);
1988 }
1989 if (elseChain != null) {
1990 code.resolve(elseChain);
1991 int startpc = genCrt ? code.curCP() : 0;
1992 code.statBegin(tree.falsepart.pos);
1993 genExpr(tree.falsepart, pt).load();
1994 code.state.forceStackTop(tree.type);
1995 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
1996 startpc, code.curCP());
1997 }
1998 code.resolve(thenExit);
1999 result = items.makeStackItem(pt);
2000 }
2001
2002 private void setTypeAnnotationPositions(int treePos) {
2003 MethodSymbol meth = code.meth;
2004 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR
2005 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT;
2006
2007 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
2008 if (ta.hasUnknownPosition())
2009 ta.tryFixPosition();
2010
2011 if (ta.position.matchesPos(treePos))
2012 ta.position.updatePosOffset(code.cp);
2013 }
2014
2015 if (!initOrClinit)
2016 return;
2017
2018 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
2019 if (ta.hasUnknownPosition())
2020 ta.tryFixPosition();
2021
2022 if (ta.position.matchesPos(treePos))
2023 ta.position.updatePosOffset(code.cp);
2024 }
2025
2026 ClassSymbol clazz = meth.enclClass();
2027 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
2028 if (!s.getKind().isField())
2029 continue;
2030
2031 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
2032 if (ta.hasUnknownPosition())
2033 ta.tryFixPosition();
2034
2035 if (ta.position.matchesPos(treePos))
2036 ta.position.updatePosOffset(code.cp);
2037 }
2038 }
2039 }
2040
2041 public void visitNewClass(JCNewClass tree) {
2042 // Enclosing instances or anonymous classes should have been eliminated
2043 // by now.
2044 Assert.check(tree.encl == null && tree.def == null);
2045 setTypeAnnotationPositions(tree.pos);
2046
2047 code.emitop2(new_, checkDimension(tree.pos(), tree.type), PoolWriter::putClass);
2048 code.emitop0(dup);
2049
2050 // Generate code for all arguments, where the expected types are
2051 // the parameters of the constructor's external type (that is,
2052 // any implicit outer instance appears as first parameter).
2053 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
2054
2055 items.makeMemberItem(tree.constructor, true).invoke();
2056 result = items.makeStackItem(tree.type);
2057 }
2058
2059 public void visitNewArray(JCNewArray tree) {
2060 setTypeAnnotationPositions(tree.pos);
2061
2062 if (tree.elems != null) {
2063 Type elemtype = types.elemtype(tree.type);
2064 loadIntConst(tree.elems.length());
2065 Item arr = makeNewArray(tree.pos(), tree.type, 1);
2066 int i = 0;
2067 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
2068 arr.duplicate();
2069 loadIntConst(i);
2070 i++;
2071 genExpr(l.head, elemtype).load();
2072 items.makeIndexedItem(elemtype).store();
2073 }
2074 result = arr;
2075 } else {
2076 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
2077 genExpr(l.head, syms.intType).load();
2078 }
2079 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
2080 }
2081 }
2082 //where
2083 /** Generate code to create an array with given element type and number
2084 * of dimensions.
2085 */
2086 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
2087 Type elemtype = types.elemtype(type);
2088 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
2089 log.error(pos, Errors.LimitDimensions);
2090 nerrs++;
2091 }
2092 int elemcode = Code.arraycode(elemtype);
2093 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
2094 code.emitAnewarray(makeRef(pos, elemtype), type);
2095 } else if (elemcode == 1) {
2096 code.emitMultianewarray(ndims, makeRef(pos, type), type);
2097 } else {
2098 code.emitNewarray(elemcode, type);
2099 }
2100 return items.makeStackItem(type);
2101 }
2102
2103 public void visitParens(JCParens tree) {
2104 result = genExpr(tree.expr, tree.expr.type);
2105 }
2106
2107 public void visitAssign(JCAssign tree) {
2108 Item l = genExpr(tree.lhs, tree.lhs.type);
2109 genExpr(tree.rhs, tree.lhs.type).load();
2110 if (tree.rhs.type.hasTag(BOT)) {
2111 /* This is just a case of widening reference conversion that per 5.1.5 simply calls
2112 for "regarding a reference as having some other type in a manner that can be proved
2113 correct at compile time."
2114 */
2115 code.state.forceStackTop(tree.lhs.type);
2116 }
2117 result = items.makeAssignItem(l);
2118 }
2119
2120 public void visitAssignop(JCAssignOp tree) {
2121 OperatorSymbol operator = tree.operator;
2122 Item l;
2123 if (operator.opcode == string_add) {
2124 l = concat.makeConcat(tree);
2125 } else {
2126 // Generate code for first expression
2127 l = genExpr(tree.lhs, tree.lhs.type);
2128
2129 // If we have an increment of -32768 to +32767 of a local
2130 // int variable we can use an incr instruction instead of
2131 // proceeding further.
2132 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
2133 l instanceof LocalItem localItem &&
2134 tree.lhs.type.getTag().isSubRangeOf(INT) &&
2135 tree.rhs.type.getTag().isSubRangeOf(INT) &&
2136 tree.rhs.type.constValue() != null) {
2137 int ival = ((Number) tree.rhs.type.constValue()).intValue();
2138 if (tree.hasTag(MINUS_ASG)) ival = -ival;
2139 localItem.incr(ival);
2140 result = l;
2141 return;
2142 }
2143 // Otherwise, duplicate expression, load one copy
2144 // and complete binary operation.
2145 l.duplicate();
2146 l.coerce(operator.type.getParameterTypes().head).load();
2147 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
2148 }
2149 result = items.makeAssignItem(l);
2150 }
2151
2152 public void visitUnary(JCUnary tree) {
2153 OperatorSymbol operator = tree.operator;
2154 if (tree.hasTag(NOT)) {
2155 CondItem od = genCond(tree.arg, false);
2156 result = od.negate();
2157 } else {
2158 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
2159 switch (tree.getTag()) {
2160 case POS:
2161 result = od.load();
2162 break;
2163 case NEG:
2164 result = od.load();
2165 code.emitop0(operator.opcode);
2166 break;
2167 case COMPL:
2168 result = od.load();
2169 emitMinusOne(od.typecode);
2170 code.emitop0(operator.opcode);
2171 break;
2172 case PREINC: case PREDEC:
2173 od.duplicate();
2174 if (od instanceof LocalItem localItem &&
2175 (operator.opcode == iadd || operator.opcode == isub)) {
2176 localItem.incr(tree.hasTag(PREINC) ? 1 : -1);
2177 result = od;
2178 } else {
2179 od.load();
2180 code.emitop0(one(od.typecode));
2181 code.emitop0(operator.opcode);
2182 // Perform narrowing primitive conversion if byte,
2183 // char, or short. Fix for 4304655.
2184 if (od.typecode != INTcode &&
2185 Code.truncate(od.typecode) == INTcode)
2186 code.emitop0(int2byte + od.typecode - BYTEcode);
2187 result = items.makeAssignItem(od);
2188 }
2189 break;
2190 case POSTINC: case POSTDEC:
2191 od.duplicate();
2192 if (od instanceof LocalItem localItem &&
2193 (operator.opcode == iadd || operator.opcode == isub)) {
2194 Item res = od.load();
2195 localItem.incr(tree.hasTag(POSTINC) ? 1 : -1);
2196 result = res;
2197 } else {
2198 Item res = od.load();
2199 od.stash(od.typecode);
2200 code.emitop0(one(od.typecode));
2201 code.emitop0(operator.opcode);
2202 // Perform narrowing primitive conversion if byte,
2203 // char, or short. Fix for 4304655.
2204 if (od.typecode != INTcode &&
2205 Code.truncate(od.typecode) == INTcode)
2206 code.emitop0(int2byte + od.typecode - BYTEcode);
2207 od.store();
2208 result = res;
2209 }
2210 break;
2211 case NULLCHK:
2212 result = od.load();
2213 code.emitop0(dup);
2214 genNullCheck(tree);
2215 break;
2216 default:
2217 Assert.error();
2218 }
2219 }
2220 }
2221
2222 /** Generate a null check from the object value at stack top. */
2223 private void genNullCheck(JCTree tree) {
2224 code.statBegin(tree.pos);
2225 callMethod(tree.pos(), syms.objectsType, names.requireNonNull,
2226 List.of(syms.objectType), true);
2227 code.emitop0(pop);
2228 }
2229
2230 public void visitBinary(JCBinary tree) {
2231 OperatorSymbol operator = tree.operator;
2232 if (operator.opcode == string_add) {
2233 result = concat.makeConcat(tree);
2234 } else if (tree.hasTag(AND)) {
2235 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2236 if (!lcond.isFalse()) {
2237 Chain falseJumps = lcond.jumpFalse();
2238 code.resolve(lcond.trueJumps);
2239 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2240 result = items.
2241 makeCondItem(rcond.opcode,
2242 rcond.trueJumps,
2243 Code.mergeChains(falseJumps,
2244 rcond.falseJumps));
2245 } else {
2246 result = lcond;
2247 }
2248 } else if (tree.hasTag(OR)) {
2249 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2250 if (!lcond.isTrue()) {
2251 Chain trueJumps = lcond.jumpTrue();
2252 code.resolve(lcond.falseJumps);
2253 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2254 result = items.
2255 makeCondItem(rcond.opcode,
2256 Code.mergeChains(trueJumps, rcond.trueJumps),
2257 rcond.falseJumps);
2258 } else {
2259 result = lcond;
2260 }
2261 } else {
2262 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
2263 od.load();
2264 result = completeBinop(tree.lhs, tree.rhs, operator);
2265 }
2266 }
2267
2268
2269 /** Complete generating code for operation, with left operand
2270 * already on stack.
2271 * @param lhs The tree representing the left operand.
2272 * @param rhs The tree representing the right operand.
2273 * @param operator The operator symbol.
2274 */
2275 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2276 MethodType optype = (MethodType)operator.type;
2277 int opcode = operator.opcode;
2278 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2279 rhs.type.constValue() instanceof Number number &&
2280 number.intValue() == 0) {
2281 opcode = opcode + (ifeq - if_icmpeq);
2282 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2283 TreeInfo.isNull(rhs)) {
2284 opcode = opcode + (if_acmp_null - if_acmpeq);
2285 } else {
2286 // The expected type of the right operand is
2287 // the second parameter type of the operator, except for
2288 // shifts with long shiftcount, where we convert the opcode
2289 // to a short shift and the expected type to int.
2290 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2291 if (opcode >= ishll && opcode <= lushrl) {
2292 opcode = opcode + (ishl - ishll);
2293 rtype = syms.intType;
2294 }
2295 // Generate code for right operand and load.
2296 genExpr(rhs, rtype).load();
2297 // If there are two consecutive opcode instructions,
2298 // emit the first now.
2299 if (opcode >= (1 << preShift)) {
2300 code.emitop0(opcode >> preShift);
2301 opcode = opcode & 0xFF;
2302 }
2303 }
2304 if (opcode >= ifeq && opcode <= if_acmpne ||
2305 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2306 return items.makeCondItem(opcode);
2307 } else {
2308 code.emitop0(opcode);
2309 return items.makeStackItem(optype.restype);
2310 }
2311 }
2312
2313 public void visitTypeCast(JCTypeCast tree) {
2314 result = genExpr(tree.expr, tree.clazz.type).load();
2315 setTypeAnnotationPositions(tree.pos);
2316 // Additional code is only needed if we cast to a reference type
2317 // which is not statically a supertype of the expression's type.
2318 // For basic types, the coerce(...) in genExpr(...) will do
2319 // the conversion.
2320 if (!tree.clazz.type.isPrimitive() &&
2321 !types.isSameType(tree.expr.type, tree.clazz.type) &&
2322 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2323 code.emitop2(checkcast, checkDimension(tree.pos(), tree.clazz.type), PoolWriter::putClass);
2324 }
2325 }
2326
2327 public void visitWildcard(JCWildcard tree) {
2328 throw new AssertionError(this.getClass().getName());
2329 }
2330
2331 public void visitTypeTest(JCInstanceOf tree) {
2332 genExpr(tree.expr, tree.expr.type).load();
2333 setTypeAnnotationPositions(tree.pos);
2334 code.emitop2(instanceof_, makeRef(tree.pos(), tree.pattern.type));
2335 result = items.makeStackItem(syms.booleanType);
2336 }
2337
2338 public void visitIndexed(JCArrayAccess tree) {
2339 genExpr(tree.indexed, tree.indexed.type).load();
2340 genExpr(tree.index, syms.intType).load();
2341 result = items.makeIndexedItem(tree.type);
2342 }
2343
2344 public void visitIdent(JCIdent tree) {
2345 Symbol sym = tree.sym;
2346 if (tree.name == names._this || tree.name == names._super) {
2347 Item res = tree.name == names._this
2348 ? items.makeThisItem()
2349 : items.makeSuperItem();
2350 if (sym.kind == MTH) {
2351 // Generate code to address the constructor.
2352 res.load();
2353 res = items.makeMemberItem(sym, true);
2354 }
2355 result = res;
2356 } else if (isInvokeDynamic(sym) || isConstantDynamic(sym)) {
2357 if (isConstantDynamic(sym)) {
2358 setTypeAnnotationPositions(tree.pos);
2359 }
2360 result = items.makeDynamicItem(sym);
2361 } else if (sym.kind == VAR && (sym.owner.kind == MTH || sym.owner.kind == VAR)) {
2362 result = items.makeLocalItem((VarSymbol)sym);
2363 } else if ((sym.flags() & STATIC) != 0) {
2364 if (!isAccessSuper(env.enclMethod))
2365 sym = binaryQualifier(sym, env.enclClass.type);
2366 result = items.makeStaticItem(sym);
2367 } else {
2368 items.makeThisItem().load();
2369 sym = binaryQualifier(sym, env.enclClass.type);
2370 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym));
2371 }
2372 }
2373
2374 //where
2375 private boolean nonVirtualForPrivateAccess(Symbol sym) {
2376 boolean useVirtual = target.hasVirtualPrivateInvoke() &&
2377 !disableVirtualizedPrivateInvoke;
2378 return !useVirtual && ((sym.flags() & PRIVATE) != 0);
2379 }
2380
2381 public void visitSelect(JCFieldAccess tree) {
2382 Symbol sym = tree.sym;
2383
2384 if (tree.name == names._class) {
2385 code.emitLdc((LoadableConstant)checkDimension(tree.pos(), tree.selected.type));
2386 result = items.makeStackItem(pt);
2387 return;
2388 }
2389
2390 Symbol ssym = TreeInfo.symbol(tree.selected);
2391
2392 // Are we selecting via super?
2393 boolean selectSuper =
2394 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2395
2396 // Are we accessing a member of the superclass in an access method
2397 // resulting from a qualified super?
2398 boolean accessSuper = isAccessSuper(env.enclMethod);
2399
2400 Item base = (selectSuper)
2401 ? items.makeSuperItem()
2402 : genExpr(tree.selected, tree.selected.type);
2403
2404 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2405 // We are seeing a variable that is constant but its selecting
2406 // expression is not.
2407 if ((sym.flags() & STATIC) != 0) {
2408 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2409 base = base.load();
2410 base.drop();
2411 } else {
2412 base.load();
2413 genNullCheck(tree.selected);
2414 }
2415 result = items.
2416 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2417 } else {
2418 if (isInvokeDynamic(sym)) {
2419 result = items.makeDynamicItem(sym);
2420 return;
2421 } else {
2422 sym = binaryQualifier(sym, tree.selected.type);
2423 }
2424 if ((sym.flags() & STATIC) != 0) {
2425 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2426 base = base.load();
2427 base.drop();
2428 result = items.makeStaticItem(sym);
2429 } else {
2430 base.load();
2431 if (sym == syms.lengthVar) {
2432 code.emitop0(arraylength);
2433 result = items.makeStackItem(syms.intType);
2434 } else {
2435 result = items.
2436 makeMemberItem(sym,
2437 nonVirtualForPrivateAccess(sym) ||
2438 selectSuper || accessSuper);
2439 }
2440 }
2441 }
2442 }
2443
2444 public boolean isInvokeDynamic(Symbol sym) {
2445 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
2446 }
2447
2448 public void visitLiteral(JCLiteral tree) {
2449 if (tree.type.hasTag(BOT)) {
2450 code.emitop0(aconst_null);
2451 result = items.makeStackItem(tree.type);
2452 }
2453 else
2454 result = items.makeImmediateItem(tree.type, tree.value);
2455 }
2456
2457 public void visitLetExpr(LetExpr tree) {
2458 code.resolvePending();
2459
2460 int limit = code.nextreg;
2461 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
2462 try {
2463 genStats(tree.defs, env);
2464 } finally {
2465 code.setLetExprStackPos(prevLetExprStart);
2466 }
2467 result = genExpr(tree.expr, tree.expr.type).load();
2468 code.endScopes(limit);
2469 }
2470
2471 private void generateReferencesToPrunedTree(ClassSymbol classSymbol) {
2472 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
2473 if (prunedInfo != null) {
2474 for (JCTree prunedTree: prunedInfo) {
2475 prunedTree.accept(classReferenceVisitor);
2476 }
2477 }
2478 }
2479
2480 /* ************************************************************************
2481 * main method
2482 *************************************************************************/
2483
2484 /** Generate code for a class definition.
2485 * @param env The attribution environment that belongs to the
2486 * outermost class containing this class definition.
2487 * We need this for resolving some additional symbols.
2488 * @param cdef The tree representing the class definition.
2489 * @return True if code is generated with no errors.
2490 */
2491 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2492 try {
2493 attrEnv = env;
2494 ClassSymbol c = cdef.sym;
2495 this.toplevel = env.toplevel;
2496 this.endPosTable = toplevel.endPositions;
2497 /* method normalizeDefs() can add references to external classes into the constant pool
2498 */
2499 cdef.defs = normalizeDefs(cdef.defs, c);
2500 generateReferencesToPrunedTree(c);
2501 Env<GenContext> localEnv = new Env<>(cdef, new GenContext());
2502 localEnv.toplevel = env.toplevel;
2503 localEnv.enclClass = cdef;
2504
2505 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2506 genDef(l.head, localEnv);
2507 }
2508 if (poolWriter.size() > PoolWriter.MAX_ENTRIES) {
2509 log.error(cdef.pos(), Errors.LimitPool);
2510 nerrs++;
2511 }
2512 if (nerrs != 0) {
2513 // if errors, discard code
2514 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2515 if (l.head.hasTag(METHODDEF))
2516 ((JCMethodDecl) l.head).sym.code = null;
2517 }
2518 }
2519 cdef.defs = List.nil(); // discard trees
2520 return nerrs == 0;
2521 } finally {
2522 // note: this method does NOT support recursion.
2523 attrEnv = null;
2524 this.env = null;
2525 toplevel = null;
2526 endPosTable = null;
2527 nerrs = 0;
2528 qualifiedSymbolCache.clear();
2529 }
2530 }
2531
2532 /* ************************************************************************
2533 * Auxiliary classes
2534 *************************************************************************/
2535
2536 /** An abstract class for finalizer generation.
2537 */
2538 abstract class GenFinalizer {
2539 /** Generate code to clean up when unwinding. */
2540 abstract void gen();
2541
2542 /** Generate code to clean up at last. */
2543 abstract void genLast();
2544
2545 /** Does this finalizer have some nontrivial cleanup to perform? */
2546 boolean hasFinalizer() { return true; }
2547
2548 /** Should be invoked after the try's body has been visited. */
2549 void afterBody() {}
2550 }
2551
2552 /** code generation contexts,
2553 * to be used as type parameter for environments.
2554 */
2555 static class GenContext {
2556
2557 /** A chain for all unresolved jumps that exit the current environment.
2558 */
2559 Chain exit = null;
2560
2561 /** A chain for all unresolved jumps that continue in the
2562 * current environment.
2563 */
2564 Chain cont = null;
2565
2566 /** A closure that generates the finalizer of the current environment.
2567 * Only set for Synchronized and Try contexts.
2568 */
2569 GenFinalizer finalize = null;
2570
2571 /** Is this a switch statement? If so, allocate registers
2572 * even when the variable declaration is unreachable.
2573 */
2574 boolean isSwitch = false;
2575
2576 /** A list buffer containing all gaps in the finalizer range,
2577 * where a catch all exception should not apply.
2578 */
2579 ListBuffer<Integer> gaps = null;
2580
2581 /** Add given chain to exit chain.
2582 */
2583 void addExit(Chain c) {
2584 exit = Code.mergeChains(c, exit);
2585 }
2586
2587 /** Add given chain to cont chain.
2588 */
2589 void addCont(Chain c) {
2590 cont = Code.mergeChains(c, cont);
2591 }
2592 }
2593
2594 }