1 /*
2 * Copyright (c) 1999, 2025, 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 PatternMatchingCatchConfiguration patternMatchingCatchConfiguration =
176 new PatternMatchingCatchConfiguration(Set.of(), null, null, null);
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 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>();
428 ListBuffer<JCStatement> clinitCode = new ListBuffer<>();
429 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>();
430 ListBuffer<JCTree> methodDefs = new ListBuffer<>();
431 // Sort definitions into three listbuffers:
432 // - initCode for instance initializers
433 // - clinitCode for class initializers
434 // - methodDefs for method definitions
435 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
436 JCTree def = l.head;
437 switch (def.getTag()) {
438 case BLOCK:
439 JCBlock block = (JCBlock)def;
440 if ((block.flags & STATIC) != 0)
441 clinitCode.append(block);
442 else if ((block.flags & SYNTHETIC) == 0)
443 initCode.append(block);
444 break;
445 case METHODDEF:
446 methodDefs.append(def);
447 break;
448 case VARDEF:
449 JCVariableDecl vdef = (JCVariableDecl) def;
450 VarSymbol sym = vdef.sym;
451 checkDimension(vdef.pos(), sym.type);
452 if (vdef.init != null) {
453 if ((sym.flags() & STATIC) == 0) {
454 // Always initialize instance variables.
455 JCStatement init = make.at(vdef.pos()).
456 Assignment(sym, vdef.init);
457 initCode.append(init);
458 endPosTable.replaceTree(vdef, init);
459 initTAs.addAll(getAndRemoveNonFieldTAs(sym));
460 } else if (sym.getConstValue() == null) {
461 // Initialize class (static) variables only if
462 // they are not compile-time constants.
463 JCStatement init = make.at(vdef.pos).
464 Assignment(sym, vdef.init);
465 clinitCode.append(init);
466 endPosTable.replaceTree(vdef, init);
467 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym));
468 } else {
469 checkStringConstant(vdef.init.pos(), sym.getConstValue());
470 /* if the init contains a reference to an external class, add it to the
471 * constant's pool
472 */
473 vdef.init.accept(classReferenceVisitor);
474 }
475 }
476 break;
477 default:
478 Assert.error();
479 }
480 }
481 // Insert any instance initializers into all constructors.
482 if (initCode.length() != 0) {
483 List<JCStatement> inits = initCode.toList();
484 initTAs.addAll(c.getInitTypeAttributes());
485 List<Attribute.TypeCompound> initTAlist = initTAs.toList();
486 for (JCTree t : methodDefs) {
487 normalizeMethod((JCMethodDecl)t, inits, initTAlist);
488 }
489 }
490 // If there are class initializers, create a <clinit> method
491 // that contains them as its body.
492 if (clinitCode.length() != 0) {
493 MethodSymbol clinit = new MethodSymbol(
494 STATIC | (c.flags() & STRICTFP),
495 names.clinit,
496 new MethodType(
497 List.nil(), syms.voidType,
498 List.nil(), syms.methodClass),
499 c);
500 c.members().enter(clinit);
501 List<JCStatement> clinitStats = clinitCode.toList();
502 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
503 block.bracePos = TreeInfo.endPos(clinitStats.last());
504 methodDefs.append(make.MethodDef(clinit, block));
505
506 if (!clinitTAs.isEmpty())
507 clinit.appendUniqueTypeAttributes(clinitTAs.toList());
508 if (!c.getClassInitTypeAttributes().isEmpty())
509 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes());
510 }
511 // Return all method definitions.
512 return methodDefs.toList();
513 }
514
515 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) {
516 List<TypeCompound> tas = sym.getRawTypeAttributes();
517 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>();
518 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>();
519 for (TypeCompound ta : tas) {
520 Assert.check(ta.getPosition().type != TargetType.UNKNOWN);
521 if (ta.getPosition().type == TargetType.FIELD) {
522 fieldTAs.add(ta);
523 } else {
524 nonfieldTAs.add(ta);
525 }
526 }
527 sym.setTypeAttributes(fieldTAs.toList());
528 return nonfieldTAs.toList();
529 }
530
531 /** Check a constant value and report if it is a string that is
532 * too large.
533 */
534 private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
535 if (nerrs != 0 || // only complain about a long string once
536 constValue == null ||
537 !(constValue instanceof String str) ||
538 str.length() < PoolWriter.MAX_STRING_LENGTH)
539 return;
540 log.error(pos, Errors.LimitString);
541 nerrs++;
542 }
543
544 /** Insert instance initializer code into constructors prior to the super() call.
545 * @param md The tree potentially representing a
546 * constructor's definition.
547 * @param initCode The list of instance initializer statements.
548 * @param initTAs Type annotations from the initializer expression.
549 */
550 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<TypeCompound> initTAs) {
551 if (TreeInfo.isConstructor(md) && TreeInfo.hasConstructorCall(md, names._super)) {
552 // We are seeing a constructor that has a super() call.
553 // Find the super() invocation and append the given initializer code.
554 TreeInfo.mapSuperCalls(md.body, supercall -> make.Block(0, initCode.prepend(supercall)));
555
556 if (md.body.bracePos == Position.NOPOS)
557 md.body.bracePos = TreeInfo.endPos(md.body.stats.last());
558
559 md.sym.appendUniqueTypeAttributes(initTAs);
560 }
561 }
562
563 /* ************************************************************************
564 * Traversal methods
565 *************************************************************************/
566
567 /** Visitor argument: The current environment.
568 */
569 Env<GenContext> env;
570
571 /** Visitor argument: The expected type (prototype).
572 */
573 Type pt;
574
575 /** Visitor result: The item representing the computed value.
576 */
577 Item result;
578
579 /** Visitor method: generate code for a definition, catching and reporting
580 * any completion failures.
581 * @param tree The definition to be visited.
582 * @param env The environment current at the definition.
583 */
584 public void genDef(JCTree tree, Env<GenContext> env) {
585 Env<GenContext> prevEnv = this.env;
586 try {
587 this.env = env;
588 tree.accept(this);
589 } catch (CompletionFailure ex) {
590 chk.completionError(tree.pos(), ex);
591 } finally {
592 this.env = prevEnv;
593 }
594 }
595
596 /** Derived visitor method: check whether CharacterRangeTable
597 * should be emitted, if so, put a new entry into CRTable
598 * and call method to generate bytecode.
599 * If not, just call method to generate bytecode.
600 * @see #genStat(JCTree, Env)
601 *
602 * @param tree The tree to be visited.
603 * @param env The environment to use.
604 * @param crtFlags The CharacterRangeTable flags
605 * indicating type of the entry.
606 */
607 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
608 if (!genCrt) {
609 genStat(tree, env);
610 return;
611 }
612 int startpc = code.curCP();
613 genStat(tree, env);
614 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK;
615 code.crt.put(tree, crtFlags, startpc, code.curCP());
616 }
617
618 /** Derived visitor method: generate code for a statement.
619 */
620 public void genStat(JCTree tree, Env<GenContext> env) {
621 if (code.isAlive()) {
622 code.statBegin(tree.pos);
623 genDef(tree, env);
624 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) {
625 // variables whose declarations are in a switch
626 // can be used even if the decl is unreachable.
627 code.newLocal(((JCVariableDecl) tree).sym);
628 }
629 }
630
631 /** Derived visitor method: check whether CharacterRangeTable
632 * should be emitted, if so, put a new entry into CRTable
633 * and call method to generate bytecode.
634 * If not, just call method to generate bytecode.
635 * @see #genStats(List, Env)
636 *
637 * @param trees The list of trees to be visited.
638 * @param env The environment to use.
639 * @param crtFlags The CharacterRangeTable flags
640 * indicating type of the entry.
641 */
642 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
643 if (!genCrt) {
644 genStats(trees, env);
645 return;
646 }
647 if (trees.length() == 1) { // mark one statement with the flags
648 genStat(trees.head, env, crtFlags | CRT_STATEMENT);
649 } else {
650 int startpc = code.curCP();
651 genStats(trees, env);
652 code.crt.put(trees, crtFlags, startpc, code.curCP());
653 }
654 }
655
656 /** Derived visitor method: generate code for a list of statements.
657 */
658 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) {
659 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
660 genStat(l.head, env, CRT_STATEMENT);
661 }
662
663 /** Derived visitor method: check whether CharacterRangeTable
664 * should be emitted, if so, put a new entry into CRTable
665 * and call method to generate bytecode.
666 * If not, just call method to generate bytecode.
667 * @see #genCond(JCTree,boolean)
668 *
669 * @param tree The tree to be visited.
670 * @param crtFlags The CharacterRangeTable flags
671 * indicating type of the entry.
672 */
673 public CondItem genCond(JCTree tree, int crtFlags) {
674 if (!genCrt) return genCond(tree, false);
675 int startpc = code.curCP();
676 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
677 code.crt.put(tree, crtFlags, startpc, code.curCP());
678 return item;
679 }
680
681 /** Derived visitor method: generate code for a boolean
682 * expression in a control-flow context.
683 * @param _tree The expression to be visited.
684 * @param markBranches The flag to indicate that the condition is
685 * a flow controller so produced conditions
686 * should contain a proper tree to generate
687 * CharacterRangeTable branches for them.
688 */
689 public CondItem genCond(JCTree _tree, boolean markBranches) {
690 JCTree inner_tree = TreeInfo.skipParens(_tree);
691 if (inner_tree.hasTag(CONDEXPR)) {
692 JCConditional tree = (JCConditional)inner_tree;
693 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
694 if (cond.isTrue()) {
695 code.resolve(cond.trueJumps);
696 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
697 if (markBranches) result.tree = tree.truepart;
698 return result;
699 }
700 if (cond.isFalse()) {
701 code.resolve(cond.falseJumps);
702 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
703 if (markBranches) result.tree = tree.falsepart;
704 return result;
705 }
706 Chain secondJumps = cond.jumpFalse();
707 code.resolve(cond.trueJumps);
708 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
709 if (markBranches) first.tree = tree.truepart;
710 Chain falseJumps = first.jumpFalse();
711 code.resolve(first.trueJumps);
712 Chain trueJumps = code.branch(goto_);
713 code.resolve(secondJumps);
714 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
715 CondItem result = items.makeCondItem(second.opcode,
716 Code.mergeChains(trueJumps, second.trueJumps),
717 Code.mergeChains(falseJumps, second.falseJumps));
718 if (markBranches) result.tree = tree.falsepart;
719 return result;
720 } else if (inner_tree.hasTag(SWITCH_EXPRESSION)) {
721 code.resolvePending();
722
723 boolean prevInCondSwitchExpression = inCondSwitchExpression;
724 Chain prevSwitchExpressionTrueChain = switchExpressionTrueChain;
725 Chain prevSwitchExpressionFalseChain = switchExpressionFalseChain;
726 try {
727 inCondSwitchExpression = true;
728 switchExpressionTrueChain = null;
729 switchExpressionFalseChain = null;
730 try {
731 doHandleSwitchExpression((JCSwitchExpression) inner_tree);
732 } catch (CompletionFailure ex) {
733 chk.completionError(_tree.pos(), ex);
734 code.state.stacksize = 1;
735 }
736 CondItem result = items.makeCondItem(goto_,
737 switchExpressionTrueChain,
738 switchExpressionFalseChain);
739 if (markBranches) result.tree = _tree;
740 return result;
741 } finally {
742 inCondSwitchExpression = prevInCondSwitchExpression;
743 switchExpressionTrueChain = prevSwitchExpressionTrueChain;
744 switchExpressionFalseChain = prevSwitchExpressionFalseChain;
745 }
746 } else if (inner_tree.hasTag(LETEXPR) && ((LetExpr) inner_tree).needsCond) {
747 code.resolvePending();
748
749 LetExpr tree = (LetExpr) inner_tree;
750 int limit = code.nextreg;
751 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
752 try {
753 genStats(tree.defs, env);
754 } finally {
755 code.setLetExprStackPos(prevLetExprStart);
756 }
757 CondItem result = genCond(tree.expr, markBranches);
758 code.endScopes(limit);
759 return result;
760 } else {
761 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
762 if (markBranches) result.tree = _tree;
763 return result;
764 }
765 }
766
767 public Code getCode() {
768 return code;
769 }
770
771 public Items getItems() {
772 return items;
773 }
774
775 public Env<AttrContext> getAttrEnv() {
776 return attrEnv;
777 }
778
779 /** Visitor class for expressions which might be constant expressions.
780 * This class is a subset of TreeScanner. Intended to visit trees pruned by
781 * Lower as long as constant expressions looking for references to any
782 * ClassSymbol. Any such reference will be added to the constant pool so
783 * automated tools can detect class dependencies better.
784 */
785 class ClassReferenceVisitor extends JCTree.Visitor {
786
787 @Override
788 public void visitTree(JCTree tree) {}
789
790 @Override
791 public void visitBinary(JCBinary tree) {
792 tree.lhs.accept(this);
793 tree.rhs.accept(this);
794 }
795
796 @Override
797 public void visitSelect(JCFieldAccess tree) {
798 if (tree.selected.type.hasTag(CLASS)) {
799 makeRef(tree.selected.pos(), tree.selected.type);
800 }
801 }
802
803 @Override
804 public void visitIdent(JCIdent tree) {
805 if (tree.sym.owner instanceof ClassSymbol classSymbol) {
806 poolWriter.putClass(classSymbol);
807 }
808 }
809
810 @Override
811 public void visitConditional(JCConditional tree) {
812 tree.cond.accept(this);
813 tree.truepart.accept(this);
814 tree.falsepart.accept(this);
815 }
816
817 @Override
818 public void visitUnary(JCUnary tree) {
819 tree.arg.accept(this);
820 }
821
822 @Override
823 public void visitParens(JCParens tree) {
824 tree.expr.accept(this);
825 }
826
827 @Override
828 public void visitTypeCast(JCTypeCast tree) {
829 tree.expr.accept(this);
830 }
831 }
832
833 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor();
834
835 /** Visitor method: generate code for an expression, catching and reporting
836 * any completion failures.
837 * @param tree The expression to be visited.
838 * @param pt The expression's expected type (proto-type).
839 */
840 public Item genExpr(JCTree tree, Type pt) {
841 if (!code.isAlive()) {
842 return items.makeStackItem(pt);
843 }
844
845 Type prevPt = this.pt;
846 try {
847 if (tree.type.constValue() != null) {
848 // Short circuit any expressions which are constants
849 tree.accept(classReferenceVisitor);
850 checkStringConstant(tree.pos(), tree.type.constValue());
851 Symbol sym = TreeInfo.symbol(tree);
852 if (sym != null && isConstantDynamic(sym)) {
853 result = items.makeDynamicItem(sym);
854 } else {
855 result = items.makeImmediateItem(tree.type, tree.type.constValue());
856 }
857 } else {
858 this.pt = pt;
859 tree.accept(this);
860 }
861 return result.coerce(pt);
862 } catch (CompletionFailure ex) {
863 chk.completionError(tree.pos(), ex);
864 code.state.stacksize = 1;
865 return items.makeStackItem(pt);
866 } finally {
867 this.pt = prevPt;
868 }
869 }
870
871 public boolean isConstantDynamic(Symbol sym) {
872 return sym.kind == VAR &&
873 sym instanceof DynamicVarSymbol dynamicVarSymbol &&
874 dynamicVarSymbol.isDynamic();
875 }
876
877 /** Derived visitor method: generate code for a list of method arguments.
878 * @param trees The argument expressions to be visited.
879 * @param pts The expression's expected types (i.e. the formal parameter
880 * types of the invoked method).
881 */
882 public void genArgs(List<JCExpression> trees, List<Type> pts) {
883 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
884 genExpr(l.head, pts.head).load();
885 pts = pts.tail;
886 }
887 // require lists be of same length
888 Assert.check(pts.isEmpty());
889 }
890
891 /* ************************************************************************
892 * Visitor methods for statements and definitions
893 *************************************************************************/
894
895 /** Thrown when the byte code size exceeds limit.
896 */
897 public static class CodeSizeOverflow extends RuntimeException {
898 private static final long serialVersionUID = 0;
899 public CodeSizeOverflow() {}
900 }
901
902 public void visitMethodDef(JCMethodDecl tree) {
903 // Create a new local environment that points pack at method
904 // definition.
905 Env<GenContext> localEnv = env.dup(tree);
906 localEnv.enclMethod = tree;
907 // The expected type of every return statement in this method
908 // is the method's return type.
909 this.pt = tree.sym.erasure(types).getReturnType();
910
911 checkDimension(tree.pos(), tree.sym.erasure(types));
912 genMethod(tree, localEnv, false);
913 }
914 //where
915 /** Generate code for a method.
916 * @param tree The tree representing the method definition.
917 * @param env The environment current for the method body.
918 * @param fatcode A flag that indicates whether all jumps are
919 * within 32K. We first invoke this method under
920 * the assumption that fatcode == false, i.e. all
921 * jumps are within 32K. If this fails, fatcode
922 * is set to true and we try again.
923 */
924 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
925 MethodSymbol meth = tree.sym;
926 int extras = 0;
927 // Count up extra parameters
928 if (meth.isConstructor()) {
929 extras++;
930 if (meth.enclClass().isInner() &&
931 !meth.enclClass().isStatic()) {
932 extras++;
933 }
934 } else if ((tree.mods.flags & STATIC) == 0) {
935 extras++;
936 }
937 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
938 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
939 ClassFile.MAX_PARAMETERS) {
940 log.error(tree.pos(), Errors.LimitParameters);
941 nerrs++;
942 }
943
944 else if (tree.body != null) {
945 // Create a new code structure and initialize it.
946 int startpcCrt = initCode(tree, env, fatcode);
947
948 try {
949 genStat(tree.body, env);
950 } catch (CodeSizeOverflow e) {
951 // Failed due to code limit, try again with jsr/ret
952 startpcCrt = initCode(tree, env, fatcode);
953 genStat(tree.body, env);
954 }
955
956 if (code.state.stacksize != 0) {
957 log.error(tree.body.pos(), Errors.StackSimError(tree.sym));
958 throw new AssertionError();
959 }
960
961 // If last statement could complete normally, insert a
962 // return at the end.
963 if (code.isAlive()) {
964 code.statBegin(TreeInfo.endPos(tree.body));
965 if (env.enclMethod == null ||
966 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
967 code.emitop0(return_);
968 } else {
969 // sometime dead code seems alive (4415991);
970 // generate a small loop instead
971 int startpc = code.entryPoint();
972 CondItem c = items.makeCondItem(goto_);
973 code.resolve(c.jumpTrue(), startpc);
974 }
975 }
976 if (genCrt)
977 code.crt.put(tree.body,
978 CRT_BLOCK,
979 startpcCrt,
980 code.curCP());
981
982 code.endScopes(0);
983
984 // If we exceeded limits, panic
985 if (code.checkLimits(tree.pos(), log)) {
986 nerrs++;
987 return;
988 }
989
990 // If we generated short code but got a long jump, do it again
991 // with fatCode = true.
992 if (!fatcode && code.fatcode) genMethod(tree, env, true);
993
994 // Clean up
995 if(stackMap == StackMapFormat.JSR202) {
996 code.lastFrame = null;
997 code.frameBeforeLast = null;
998 }
999
1000 // Compress exception table
1001 code.compressCatchTable();
1002
1003 // Fill in type annotation positions for exception parameters
1004 code.fillExceptionParameterPositions();
1005 }
1006 }
1007
1008 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1009 MethodSymbol meth = tree.sym;
1010
1011 // Create a new code structure.
1012 meth.code = code = new Code(meth,
1013 fatcode,
1014 lineDebugInfo ? toplevel.lineMap : null,
1015 varDebugInfo,
1016 stackMap,
1017 debugCode,
1018 genCrt ? new CRTable(tree, env.toplevel.endPositions)
1019 : null,
1020 syms,
1021 types,
1022 poolWriter);
1023 items = new Items(poolWriter, code, syms, types);
1024 if (code.debugCode) {
1025 System.err.println(meth + " for body " + tree);
1026 }
1027
1028 // If method is not static, create a new local variable address
1029 // for `this'.
1030 if ((tree.mods.flags & STATIC) == 0) {
1031 Type selfType = meth.owner.type;
1032 if (meth.isConstructor() && selfType != syms.objectType)
1033 selfType = UninitializedType.uninitializedThis(selfType);
1034 code.setDefined(
1035 code.newLocal(
1036 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1037 }
1038
1039 // Mark all parameters as defined from the beginning of
1040 // the method.
1041 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1042 checkDimension(l.head.pos(), l.head.sym.type);
1043 code.setDefined(code.newLocal(l.head.sym));
1044 }
1045
1046 // Get ready to generate code for method body.
1047 int startpcCrt = genCrt ? code.curCP() : 0;
1048 code.entryPoint();
1049
1050 // Suppress initial stackmap
1051 code.pendingStackMap = false;
1052
1053 return startpcCrt;
1054 }
1055
1056 public void visitVarDef(JCVariableDecl tree) {
1057 VarSymbol v = tree.sym;
1058 if (tree.init != null) {
1059 checkStringConstant(tree.init.pos(), v.getConstValue());
1060 if (v.getConstValue() == null || varDebugInfo) {
1061 Assert.check(code.isStatementStart());
1062 code.newLocal(v);
1063 genExpr(tree.init, v.erasure(types)).load();
1064 items.makeLocalItem(v).store();
1065 Assert.check(code.isStatementStart());
1066 }
1067 } else {
1068 code.newLocal(v);
1069 }
1070 checkDimension(tree.pos(), v.type);
1071 }
1072
1073 public void visitSkip(JCSkip tree) {
1074 }
1075
1076 public void visitBlock(JCBlock tree) {
1077 /* this method is heavily invoked, as expected, for deeply nested blocks, if blocks doesn't happen to have
1078 * patterns there will be an unnecessary tax on memory consumption every time this method is executed, for this
1079 * reason we have created helper methods and here at a higher level we just discriminate depending on the
1080 * presence, or not, of patterns in a given block
1081 */
1082 if (tree.patternMatchingCatch != null) {
1083 visitBlockWithPatterns(tree);
1084 } else {
1085 internalVisitBlock(tree);
1086 }
1087 }
1088
1089 private void visitBlockWithPatterns(JCBlock tree) {
1090 PatternMatchingCatchConfiguration prevConfiguration = patternMatchingCatchConfiguration;
1091 try {
1092 patternMatchingCatchConfiguration =
1093 new PatternMatchingCatchConfiguration(tree.patternMatchingCatch.calls2Handle(),
1094 new ListBuffer<int[]>(),
1095 tree.patternMatchingCatch.handler(),
1096 code.state.dup());
1097 internalVisitBlock(tree);
1098 } finally {
1099 generatePatternMatchingCatch(env);
1100 patternMatchingCatchConfiguration = prevConfiguration;
1101 }
1102 }
1103
1104 private void generatePatternMatchingCatch(Env<GenContext> env) {
1105 if (patternMatchingCatchConfiguration.handler != null &&
1106 !patternMatchingCatchConfiguration.ranges.isEmpty()) {
1107 Chain skipCatch = code.branch(goto_);
1108 JCCatch handler = patternMatchingCatchConfiguration.handler();
1109 code.entryPoint(patternMatchingCatchConfiguration.startState(),
1110 handler.param.sym.type);
1111 genPatternMatchingCatch(handler,
1112 env,
1113 patternMatchingCatchConfiguration.ranges.toList());
1114 code.resolve(skipCatch);
1115 }
1116 }
1117
1118 private void internalVisitBlock(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.bracePos);
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 visitForLoop(JCForLoop tree) {
1139 int limit = code.nextreg;
1140 genStats(tree.init, env);
1141 genLoop(tree, tree.body, tree.cond, tree.step, true);
1142 code.endScopes(limit);
1143 }
1144 //where
1145 /** Generate code for a loop.
1146 * @param loop The tree representing the loop.
1147 * @param body The loop's body.
1148 * @param cond The loop's controlling condition.
1149 * @param step "Step" statements to be inserted at end of
1150 * each iteration.
1151 * @param testFirst True if the loop test belongs before the body.
1152 */
1153 private void genLoop(JCStatement loop,
1154 JCStatement body,
1155 JCExpression cond,
1156 List<JCExpressionStatement> step,
1157 boolean testFirst) {
1158 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1159 int startpc = code.entryPoint();
1160 if (testFirst) { //while or for loop
1161 CondItem c;
1162 if (cond != null) {
1163 code.statBegin(cond.pos);
1164 Assert.check(code.isStatementStart());
1165 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1166 } else {
1167 c = items.makeCondItem(goto_);
1168 }
1169 Chain loopDone = c.jumpFalse();
1170 code.resolve(c.trueJumps);
1171 Assert.check(code.isStatementStart());
1172 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1173 code.resolve(loopEnv.info.cont);
1174 genStats(step, loopEnv);
1175 code.resolve(code.branch(goto_), startpc);
1176 code.resolve(loopDone);
1177 } else {
1178 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1179 code.resolve(loopEnv.info.cont);
1180 genStats(step, loopEnv);
1181 if (code.isAlive()) {
1182 CondItem c;
1183 if (cond != null) {
1184 code.statBegin(cond.pos);
1185 Assert.check(code.isStatementStart());
1186 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1187 } else {
1188 c = items.makeCondItem(goto_);
1189 }
1190 code.resolve(c.jumpTrue(), startpc);
1191 Assert.check(code.isStatementStart());
1192 code.resolve(c.falseJumps);
1193 }
1194 }
1195 code.resolve(loopEnv.info.exit);
1196 }
1197
1198 public void visitForeachLoop(JCEnhancedForLoop tree) {
1199 throw new AssertionError(); // should have been removed by Lower.
1200 }
1201
1202 public void visitLabelled(JCLabeledStatement tree) {
1203 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1204 genStat(tree.body, localEnv, CRT_STATEMENT);
1205 code.resolve(localEnv.info.exit);
1206 }
1207
1208 public void visitSwitch(JCSwitch tree) {
1209 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1210 }
1211
1212 @Override
1213 public void visitSwitchExpression(JCSwitchExpression tree) {
1214 code.resolvePending();
1215 boolean prevInCondSwitchExpression = inCondSwitchExpression;
1216 try {
1217 inCondSwitchExpression = false;
1218 doHandleSwitchExpression(tree);
1219 } finally {
1220 inCondSwitchExpression = prevInCondSwitchExpression;
1221 }
1222 result = items.makeStackItem(pt);
1223 }
1224
1225 private void doHandleSwitchExpression(JCSwitchExpression tree) {
1226 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
1227 LocalItem prevSwitchResult = switchResult;
1228 int limit = code.nextreg;
1229 try {
1230 stackBeforeSwitchExpression = List.nil();
1231 switchResult = null;
1232 if (hasTry(tree)) {
1233 //if the switch expression contains try-catch, the catch handlers need to have
1234 //an empty stack. So stash whole stack to local variables, and restore it before
1235 //breaks:
1236 while (code.state.stacksize > 0) {
1237 Type type = code.state.peek();
1238 Name varName = names.fromString(target.syntheticNameChar() +
1239 "stack" +
1240 target.syntheticNameChar() +
1241 tree.pos +
1242 target.syntheticNameChar() +
1243 code.state.stacksize);
1244 VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type,
1245 this.env.enclMethod.sym);
1246 LocalItem item = items.new LocalItem(type, code.newLocal(var));
1247 stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item);
1248 item.store();
1249 }
1250 switchResult = makeTemp(tree.type);
1251 }
1252 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
1253 try {
1254 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1255 } finally {
1256 code.setLetExprStackPos(prevLetExprStart);
1257 }
1258 } finally {
1259 stackBeforeSwitchExpression = prevStackBeforeSwitchExpression;
1260 switchResult = prevSwitchResult;
1261 code.endScopes(limit);
1262 }
1263 }
1264 //where:
1265 private boolean hasTry(JCSwitchExpression tree) {
1266 class HasTryScanner extends TreeScanner {
1267 private boolean hasTry;
1268
1269 @Override
1270 public void visitTry(JCTry tree) {
1271 hasTry = true;
1272 }
1273
1274 @Override
1275 public void visitSynchronized(JCSynchronized tree) {
1276 hasTry = true;
1277 }
1278
1279 @Override
1280 public void visitClassDef(JCClassDecl tree) {
1281 }
1282
1283 @Override
1284 public void visitLambda(JCLambda tree) {
1285 }
1286 };
1287
1288 HasTryScanner hasTryScanner = new HasTryScanner();
1289
1290 hasTryScanner.scan(tree);
1291 return hasTryScanner.hasTry;
1292 }
1293
1294 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases,
1295 boolean patternSwitch) {
1296 int limit = code.nextreg;
1297 Assert.check(!selector.type.hasTag(CLASS));
1298 int switchStart = patternSwitch ? code.entryPoint() : -1;
1299 int startpcCrt = genCrt ? code.curCP() : 0;
1300 Assert.check(code.isStatementStart());
1301 Item sel = genExpr(selector, syms.intType);
1302 if (cases.isEmpty()) {
1303 // We are seeing: switch <sel> {}
1304 sel.load().drop();
1305 if (genCrt)
1306 code.crt.put(TreeInfo.skipParens(selector),
1307 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1308 } else {
1309 // We are seeing a nonempty switch.
1310 sel.load();
1311 if (genCrt)
1312 code.crt.put(TreeInfo.skipParens(selector),
1313 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1314 Env<GenContext> switchEnv = env.dup(swtch, new GenContext());
1315 switchEnv.info.isSwitch = true;
1316
1317 // Compute number of labels and minimum and maximum label values.
1318 // For each case, store its label in an array.
1319 int lo = Integer.MAX_VALUE; // minimum label.
1320 int hi = Integer.MIN_VALUE; // maximum label.
1321 int nlabels = 0; // number of labels.
1322
1323 int[] labels = new int[cases.length()]; // the label array.
1324 int defaultIndex = -1; // the index of the default clause.
1325
1326 List<JCCase> l = cases;
1327 for (int i = 0; i < labels.length; i++) {
1328 if (l.head.labels.head instanceof JCConstantCaseLabel constLabel) {
1329 Assert.check(l.head.labels.size() == 1);
1330 int val = ((Number) constLabel.expr.type.constValue()).intValue();
1331 labels[i] = val;
1332 if (val < lo) lo = val;
1333 if (hi < val) hi = val;
1334 nlabels++;
1335 } else {
1336 Assert.check(defaultIndex == -1);
1337 defaultIndex = i;
1338 }
1339 l = l.tail;
1340 }
1341
1342 // Determine whether to issue a tableswitch or a lookupswitch
1343 // instruction.
1344 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1345 long table_time_cost = 3; // comparisons
1346 long lookup_space_cost = 3 + 2 * (long) nlabels;
1347 long lookup_time_cost = nlabels;
1348 int opcode =
1349 nlabels > 0 &&
1350 table_space_cost + 3 * table_time_cost <=
1351 lookup_space_cost + 3 * lookup_time_cost
1352 ?
1353 tableswitch : lookupswitch;
1354
1355 int startpc = code.curCP(); // the position of the selector operation
1356 code.emitop0(opcode);
1357 code.align(4);
1358 int tableBase = code.curCP(); // the start of the jump table
1359 int[] offsets = null; // a table of offsets for a lookupswitch
1360 code.emit4(-1); // leave space for default offset
1361 if (opcode == tableswitch) {
1362 code.emit4(lo); // minimum label
1363 code.emit4(hi); // maximum label
1364 for (long i = lo; i <= hi; i++) { // leave space for jump table
1365 code.emit4(-1);
1366 }
1367 } else {
1368 code.emit4(nlabels); // number of labels
1369 for (int i = 0; i < nlabels; i++) {
1370 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1371 }
1372 offsets = new int[labels.length];
1373 }
1374 Code.State stateSwitch = code.state.dup();
1375 code.markDead();
1376
1377 // For each case do:
1378 l = cases;
1379 for (int i = 0; i < labels.length; i++) {
1380 JCCase c = l.head;
1381 l = l.tail;
1382
1383 int pc = code.entryPoint(stateSwitch);
1384 // Insert offset directly into code or else into the
1385 // offsets table.
1386 if (i != defaultIndex) {
1387 if (opcode == tableswitch) {
1388 code.put4(
1389 tableBase + 4 * (labels[i] - lo + 3),
1390 pc - startpc);
1391 } else {
1392 offsets[i] = pc - startpc;
1393 }
1394 } else {
1395 code.put4(tableBase, pc - startpc);
1396 }
1397
1398 // Generate code for the statements in this case.
1399 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1400 }
1401
1402 if (switchEnv.info.cont != null) {
1403 Assert.check(patternSwitch);
1404 code.resolve(switchEnv.info.cont, switchStart);
1405 }
1406
1407 // Resolve all breaks.
1408 code.resolve(switchEnv.info.exit);
1409
1410 // If we have not set the default offset, we do so now.
1411 if (code.get4(tableBase) == -1) {
1412 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1413 }
1414
1415 if (opcode == tableswitch) {
1416 // Let any unfilled slots point to the default case.
1417 int defaultOffset = code.get4(tableBase);
1418 for (long i = lo; i <= hi; i++) {
1419 int t = (int)(tableBase + 4 * (i - lo + 3));
1420 if (code.get4(t) == -1)
1421 code.put4(t, defaultOffset);
1422 }
1423 } else {
1424 // Sort non-default offsets and copy into lookup table.
1425 if (defaultIndex >= 0)
1426 for (int i = defaultIndex; i < labels.length - 1; i++) {
1427 labels[i] = labels[i+1];
1428 offsets[i] = offsets[i+1];
1429 }
1430 if (nlabels > 0)
1431 qsort2(labels, offsets, 0, nlabels - 1);
1432 for (int i = 0; i < nlabels; i++) {
1433 int caseidx = tableBase + 8 * (i + 1);
1434 code.put4(caseidx, labels[i]);
1435 code.put4(caseidx + 4, offsets[i]);
1436 }
1437 }
1438
1439 if (swtch instanceof JCSwitchExpression) {
1440 // Emit line position for the end of a switch expression
1441 code.statBegin(TreeInfo.endPos(swtch));
1442 }
1443 }
1444 code.endScopes(limit);
1445 }
1446 //where
1447 /** Sort (int) arrays of keys and values
1448 */
1449 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1450 int i = lo;
1451 int j = hi;
1452 int pivot = keys[(i+j)/2];
1453 do {
1454 while (keys[i] < pivot) i++;
1455 while (pivot < keys[j]) j--;
1456 if (i <= j) {
1457 int temp1 = keys[i];
1458 keys[i] = keys[j];
1459 keys[j] = temp1;
1460 int temp2 = values[i];
1461 values[i] = values[j];
1462 values[j] = temp2;
1463 i++;
1464 j--;
1465 }
1466 } while (i <= j);
1467 if (lo < j) qsort2(keys, values, lo, j);
1468 if (i < hi) qsort2(keys, values, i, hi);
1469 }
1470
1471 public void visitSynchronized(JCSynchronized tree) {
1472 int limit = code.nextreg;
1473 // Generate code to evaluate lock and save in temporary variable.
1474 final LocalItem lockVar = makeTemp(syms.objectType);
1475 Assert.check(code.isStatementStart());
1476 genExpr(tree.lock, tree.lock.type).load().duplicate();
1477 lockVar.store();
1478
1479 // Generate code to enter monitor.
1480 code.emitop0(monitorenter);
1481 code.state.lock(lockVar.reg);
1482
1483 // Generate code for a try statement with given body, no catch clauses
1484 // in a new environment with the "exit-monitor" operation as finalizer.
1485 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1486 syncEnv.info.finalize = new GenFinalizer() {
1487 void gen() {
1488 genLast();
1489 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1490 syncEnv.info.gaps.append(code.curCP());
1491 }
1492 void genLast() {
1493 if (code.isAlive()) {
1494 lockVar.load();
1495 code.emitop0(monitorexit);
1496 code.state.unlock(lockVar.reg);
1497 }
1498 }
1499 };
1500 syncEnv.info.gaps = new ListBuffer<>();
1501 genTry(tree.body, List.nil(), syncEnv);
1502 code.endScopes(limit);
1503 }
1504
1505 public void visitTry(final JCTry tree) {
1506 // Generate code for a try statement with given body and catch clauses,
1507 // in a new environment which calls the finally block if there is one.
1508 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1509 final Env<GenContext> oldEnv = env;
1510 tryEnv.info.finalize = new GenFinalizer() {
1511 void gen() {
1512 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1513 tryEnv.info.gaps.append(code.curCP());
1514 genLast();
1515 }
1516 void genLast() {
1517 if (tree.finalizer != null)
1518 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1519 }
1520 boolean hasFinalizer() {
1521 return tree.finalizer != null;
1522 }
1523
1524 @Override
1525 void afterBody() {
1526 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1527 //for body-only finally, remove the GenFinalizer after try body
1528 //so that the finally is not generated to catch bodies:
1529 tryEnv.info.finalize = null;
1530 }
1531 }
1532
1533 };
1534 tryEnv.info.gaps = new ListBuffer<>();
1535 genTry(tree.body, tree.catchers, tryEnv);
1536 }
1537 //where
1538 /** Generate code for a try or synchronized statement
1539 * @param body The body of the try or synchronized statement.
1540 * @param catchers The list of catch clauses.
1541 * @param env The current environment of the body.
1542 */
1543 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1544 int limit = code.nextreg;
1545 int startpc = code.curCP();
1546 Code.State stateTry = code.state.dup();
1547 genStat(body, env, CRT_BLOCK);
1548 int endpc = code.curCP();
1549 List<Integer> gaps = env.info.gaps.toList();
1550 code.statBegin(TreeInfo.endPos(body));
1551 genFinalizer(env);
1552 code.statBegin(TreeInfo.endPos(env.tree));
1553 Chain exitChain;
1554 boolean actualTry = env.tree.hasTag(TRY);
1555 if (startpc == endpc && actualTry) {
1556 exitChain = code.branch(dontgoto);
1557 } else {
1558 exitChain = code.branch(goto_);
1559 }
1560 endFinalizerGap(env);
1561 env.info.finalize.afterBody();
1562 boolean hasFinalizer =
1563 env.info.finalize != null &&
1564 env.info.finalize.hasFinalizer();
1565 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1566 // start off with exception on stack
1567 code.entryPoint(stateTry, l.head.param.sym.type);
1568 genCatch(l.head, env, startpc, endpc, gaps);
1569 genFinalizer(env);
1570 if (hasFinalizer || l.tail.nonEmpty()) {
1571 code.statBegin(TreeInfo.endPos(env.tree));
1572 exitChain = Code.mergeChains(exitChain,
1573 code.branch(goto_));
1574 }
1575 endFinalizerGap(env);
1576 }
1577 if (hasFinalizer && (startpc != endpc || !actualTry)) {
1578 // Create a new register segment to avoid allocating
1579 // the same variables in finalizers and other statements.
1580 code.newRegSegment();
1581
1582 // Add a catch-all clause.
1583
1584 // start off with exception on stack
1585 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1586
1587 // Register all exception ranges for catch all clause.
1588 // The range of the catch all clause is from the beginning
1589 // of the try or synchronized block until the present
1590 // code pointer excluding all gaps in the current
1591 // environment's GenContext.
1592 int startseg = startpc;
1593 while (env.info.gaps.nonEmpty()) {
1594 int endseg = env.info.gaps.next().intValue();
1595 registerCatch(body.pos(), startseg, endseg,
1596 catchallpc, 0);
1597 startseg = env.info.gaps.next().intValue();
1598 }
1599 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1600 code.markStatBegin();
1601
1602 Item excVar = makeTemp(syms.throwableType);
1603 excVar.store();
1604 genFinalizer(env);
1605 code.resolvePending();
1606 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1607 code.markStatBegin();
1608
1609 excVar.load();
1610 registerCatch(body.pos(), startseg,
1611 env.info.gaps.next().intValue(),
1612 catchallpc, 0);
1613 code.emitop0(athrow);
1614 code.markDead();
1615
1616 // If there are jsr's to this finalizer, ...
1617 if (env.info.cont != null) {
1618 // Resolve all jsr's.
1619 code.resolve(env.info.cont);
1620
1621 // Mark statement line number
1622 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1623 code.markStatBegin();
1624
1625 // Save return address.
1626 LocalItem retVar = makeTemp(syms.throwableType);
1627 retVar.store();
1628
1629 // Generate finalizer code.
1630 env.info.finalize.genLast();
1631
1632 // Return.
1633 code.emitop1w(ret, retVar.reg);
1634 code.markDead();
1635 }
1636 }
1637 // Resolve all breaks.
1638 code.resolve(exitChain);
1639
1640 code.endScopes(limit);
1641 }
1642
1643 /** Generate code for a catch clause.
1644 * @param tree The catch clause.
1645 * @param env The environment current in the enclosing try.
1646 * @param startpc Start pc of try-block.
1647 * @param endpc End pc of try-block.
1648 */
1649 void genCatch(JCCatch tree,
1650 Env<GenContext> env,
1651 int startpc, int endpc,
1652 List<Integer> gaps) {
1653 if (startpc != endpc) {
1654 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs
1655 = catchTypesWithAnnotations(tree);
1656 while (gaps.nonEmpty()) {
1657 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1658 JCExpression subCatch = subCatch1.snd;
1659 int catchType = makeRef(tree.pos(), subCatch.type);
1660 int end = gaps.head.intValue();
1661 registerCatch(tree.pos(),
1662 startpc, end, code.curCP(),
1663 catchType);
1664 for (Attribute.TypeCompound tc : subCatch1.fst) {
1665 tc.position.setCatchInfo(catchType, startpc);
1666 }
1667 }
1668 gaps = gaps.tail;
1669 startpc = gaps.head.intValue();
1670 gaps = gaps.tail;
1671 }
1672 if (startpc < endpc) {
1673 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1674 JCExpression subCatch = subCatch1.snd;
1675 int catchType = makeRef(tree.pos(), subCatch.type);
1676 registerCatch(tree.pos(),
1677 startpc, endpc, code.curCP(),
1678 catchType);
1679 for (Attribute.TypeCompound tc : subCatch1.fst) {
1680 tc.position.setCatchInfo(catchType, startpc);
1681 }
1682 }
1683 }
1684 genCatchBlock(tree, env);
1685 }
1686 }
1687 void genPatternMatchingCatch(JCCatch tree,
1688 Env<GenContext> env,
1689 List<int[]> ranges) {
1690 for (int[] range : ranges) {
1691 JCExpression subCatch = tree.param.vartype;
1692 int catchType = makeRef(tree.pos(), subCatch.type);
1693 registerCatch(tree.pos(),
1694 range[0], range[1], code.curCP(),
1695 catchType);
1696 }
1697 genCatchBlock(tree, env);
1698 }
1699 void genCatchBlock(JCCatch tree, Env<GenContext> env) {
1700 VarSymbol exparam = tree.param.sym;
1701 code.statBegin(tree.pos);
1702 code.markStatBegin();
1703 int limit = code.nextreg;
1704 code.newLocal(exparam);
1705 items.makeLocalItem(exparam).store();
1706 code.statBegin(TreeInfo.firstStatPos(tree.body));
1707 genStat(tree.body, env, CRT_BLOCK);
1708 code.endScopes(limit);
1709 code.statBegin(TreeInfo.endPos(tree.body));
1710 }
1711 // where
1712 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) {
1713 return TreeInfo.isMultiCatch(tree) ?
1714 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) :
1715 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype));
1716 }
1717 // where
1718 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) {
1719 List<JCExpression> alts = tree.alternatives;
1720 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head));
1721 alts = alts.tail;
1722
1723 while(alts != null && alts.head != null) {
1724 JCExpression alt = alts.head;
1725 if (alt instanceof JCAnnotatedType annotatedType) {
1726 res = res.prepend(new Pair<>(annotate.fromAnnotations(annotatedType.annotations), alt));
1727 } else {
1728 res = res.prepend(new Pair<>(List.nil(), alt));
1729 }
1730 alts = alts.tail;
1731 }
1732 return res.reverse();
1733 }
1734
1735 /** Register a catch clause in the "Exceptions" code-attribute.
1736 */
1737 void registerCatch(DiagnosticPosition pos,
1738 int startpc, int endpc,
1739 int handler_pc, int catch_type) {
1740 char startpc1 = (char)startpc;
1741 char endpc1 = (char)endpc;
1742 char handler_pc1 = (char)handler_pc;
1743 if (startpc1 == startpc &&
1744 endpc1 == endpc &&
1745 handler_pc1 == handler_pc) {
1746 code.addCatch(startpc1, endpc1, handler_pc1,
1747 (char)catch_type);
1748 } else {
1749 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1750 nerrs++;
1751 }
1752 }
1753
1754 public void visitIf(JCIf tree) {
1755 int limit = code.nextreg;
1756 Chain thenExit = null;
1757 Assert.check(code.isStatementStart());
1758 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1759 CRT_FLOW_CONTROLLER);
1760 Chain elseChain = c.jumpFalse();
1761 Assert.check(code.isStatementStart());
1762 if (!c.isFalse()) {
1763 code.resolve(c.trueJumps);
1764 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1765 thenExit = code.branch(goto_);
1766 }
1767 if (elseChain != null) {
1768 code.resolve(elseChain);
1769 if (tree.elsepart != null) {
1770 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1771 }
1772 }
1773 code.resolve(thenExit);
1774 code.endScopes(limit);
1775 Assert.check(code.isStatementStart());
1776 }
1777
1778 public void visitExec(JCExpressionStatement tree) {
1779 // Optimize x++ to ++x and x-- to --x.
1780 JCExpression e = tree.expr;
1781 switch (e.getTag()) {
1782 case POSTINC:
1783 ((JCUnary) e).setTag(PREINC);
1784 break;
1785 case POSTDEC:
1786 ((JCUnary) e).setTag(PREDEC);
1787 break;
1788 }
1789 Assert.check(code.isStatementStart());
1790 genExpr(tree.expr, tree.expr.type).drop();
1791 Assert.check(code.isStatementStart());
1792 }
1793
1794 public void visitBreak(JCBreak tree) {
1795 Assert.check(code.isStatementStart());
1796 final Env<GenContext> targetEnv = unwindBreak(tree.target);
1797 targetEnv.info.addExit(code.branch(goto_));
1798 endFinalizerGaps(env, targetEnv);
1799 }
1800
1801 public void visitYield(JCYield tree) {
1802 Assert.check(code.isStatementStart());
1803 final Env<GenContext> targetEnv;
1804 if (inCondSwitchExpression) {
1805 CondItem value = genCond(tree.value, CRT_FLOW_TARGET);
1806 Chain falseJumps = value.jumpFalse();
1807
1808 code.resolve(value.trueJumps);
1809 Env<GenContext> localEnv = unwindBreak(tree.target);
1810 reloadStackBeforeSwitchExpr();
1811 Chain trueJumps = code.branch(goto_);
1812
1813 endFinalizerGaps(env, localEnv);
1814
1815 code.resolve(falseJumps);
1816 targetEnv = unwindBreak(tree.target);
1817 reloadStackBeforeSwitchExpr();
1818 falseJumps = code.branch(goto_);
1819
1820 if (switchExpressionTrueChain == null) {
1821 switchExpressionTrueChain = trueJumps;
1822 } else {
1823 switchExpressionTrueChain =
1824 Code.mergeChains(switchExpressionTrueChain, trueJumps);
1825 }
1826 if (switchExpressionFalseChain == null) {
1827 switchExpressionFalseChain = falseJumps;
1828 } else {
1829 switchExpressionFalseChain =
1830 Code.mergeChains(switchExpressionFalseChain, falseJumps);
1831 }
1832 } else {
1833 genExpr(tree.value, pt).load();
1834 if (switchResult != null)
1835 switchResult.store();
1836
1837 targetEnv = unwindBreak(tree.target);
1838
1839 if (code.isAlive()) {
1840 reloadStackBeforeSwitchExpr();
1841 if (switchResult != null)
1842 switchResult.load();
1843
1844 targetEnv.info.addExit(code.branch(goto_));
1845 code.markDead();
1846 }
1847 }
1848 endFinalizerGaps(env, targetEnv);
1849 }
1850 //where:
1851 /** As side-effect, might mark code as dead disabling any further emission.
1852 */
1853 private Env<GenContext> unwindBreak(JCTree target) {
1854 int tmpPos = code.pendingStatPos;
1855 Env<GenContext> targetEnv = unwind(target, env);
1856 code.pendingStatPos = tmpPos;
1857 return targetEnv;
1858 }
1859
1860 private void reloadStackBeforeSwitchExpr() {
1861 for (LocalItem li : stackBeforeSwitchExpression)
1862 li.load();
1863 }
1864
1865 public void visitContinue(JCContinue tree) {
1866 int tmpPos = code.pendingStatPos;
1867 Env<GenContext> targetEnv = unwind(tree.target, env);
1868 code.pendingStatPos = tmpPos;
1869 Assert.check(code.isStatementStart());
1870 targetEnv.info.addCont(code.branch(goto_));
1871 endFinalizerGaps(env, targetEnv);
1872 }
1873
1874 public void visitReturn(JCReturn tree) {
1875 int limit = code.nextreg;
1876 final Env<GenContext> targetEnv;
1877
1878 /* Save and then restore the location of the return in case a finally
1879 * is expanded (with unwind()) in the middle of our bytecodes.
1880 */
1881 int tmpPos = code.pendingStatPos;
1882 if (tree.expr != null) {
1883 Assert.check(code.isStatementStart());
1884 Item r = genExpr(tree.expr, pt).load();
1885 if (hasFinally(env.enclMethod, env)) {
1886 r = makeTemp(pt);
1887 r.store();
1888 }
1889 targetEnv = unwind(env.enclMethod, env);
1890 code.pendingStatPos = tmpPos;
1891 r.load();
1892 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
1893 } else {
1894 targetEnv = unwind(env.enclMethod, env);
1895 code.pendingStatPos = tmpPos;
1896 code.emitop0(return_);
1897 }
1898 endFinalizerGaps(env, targetEnv);
1899 code.endScopes(limit);
1900 }
1901
1902 public void visitThrow(JCThrow tree) {
1903 Assert.check(code.isStatementStart());
1904 genExpr(tree.expr, tree.expr.type).load();
1905 code.emitop0(athrow);
1906 Assert.check(code.isStatementStart());
1907 }
1908
1909 /* ************************************************************************
1910 * Visitor methods for expressions
1911 *************************************************************************/
1912
1913 public void visitApply(JCMethodInvocation tree) {
1914 setTypeAnnotationPositions(tree.pos);
1915 // Generate code for method.
1916 Item m = genExpr(tree.meth, methodType);
1917 // Generate code for all arguments, where the expected types are
1918 // the parameters of the method's external type (that is, any implicit
1919 // outer instance of a super(...) call appears as first parameter).
1920 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
1921 genArgs(tree.args,
1922 msym.externalType(types).getParameterTypes());
1923 if (!msym.isDynamic()) {
1924 code.statBegin(tree.pos);
1925 }
1926 if (patternMatchingCatchConfiguration.invocations().contains(tree)) {
1927 int start = code.curCP();
1928 result = m.invoke();
1929 patternMatchingCatchConfiguration.ranges().add(new int[] {start, code.curCP()});
1930 } else {
1931 if (msym.isConstructor() && TreeInfo.isConstructorCall(tree)) {
1932 //if this is a this(...) or super(...) call, there is a pending
1933 //"uninitialized this" before this call. One catch handler cannot
1934 //handle exceptions that may come from places with "uninitialized this"
1935 //and (initialized) this, hence generate one set of handlers here
1936 //for the "uninitialized this" case, and another set of handlers
1937 //will be generated at the end of the method for the initialized this,
1938 //if needed:
1939 generatePatternMatchingCatch(env);
1940 result = m.invoke();
1941 patternMatchingCatchConfiguration =
1942 patternMatchingCatchConfiguration.restart(code.state.dup());
1943 } else {
1944 result = m.invoke();
1945 }
1946 }
1947 }
1948
1949 public void visitConditional(JCConditional tree) {
1950 Chain thenExit = null;
1951 code.statBegin(tree.cond.pos);
1952 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
1953 Chain elseChain = c.jumpFalse();
1954 if (!c.isFalse()) {
1955 code.resolve(c.trueJumps);
1956 int startpc = genCrt ? code.curCP() : 0;
1957 code.statBegin(tree.truepart.pos);
1958 genExpr(tree.truepart, pt).load();
1959 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
1960 startpc, code.curCP());
1961 thenExit = code.branch(goto_);
1962 }
1963 if (elseChain != null) {
1964 code.resolve(elseChain);
1965 int startpc = genCrt ? code.curCP() : 0;
1966 code.statBegin(tree.falsepart.pos);
1967 genExpr(tree.falsepart, pt).load();
1968 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
1969 startpc, code.curCP());
1970 }
1971 code.resolve(thenExit);
1972 result = items.makeStackItem(pt);
1973 }
1974
1975 private void setTypeAnnotationPositions(int treePos) {
1976 MethodSymbol meth = code.meth;
1977 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR
1978 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT;
1979
1980 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
1981 if (ta.hasUnknownPosition())
1982 ta.tryFixPosition();
1983
1984 if (ta.position.matchesPos(treePos))
1985 ta.position.updatePosOffset(code.cp);
1986 }
1987
1988 if (!initOrClinit)
1989 return;
1990
1991 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
1992 if (ta.hasUnknownPosition())
1993 ta.tryFixPosition();
1994
1995 if (ta.position.matchesPos(treePos))
1996 ta.position.updatePosOffset(code.cp);
1997 }
1998
1999 ClassSymbol clazz = meth.enclClass();
2000 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
2001 if (!s.getKind().isField())
2002 continue;
2003
2004 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
2005 if (ta.hasUnknownPosition())
2006 ta.tryFixPosition();
2007
2008 if (ta.position.matchesPos(treePos))
2009 ta.position.updatePosOffset(code.cp);
2010 }
2011 }
2012 }
2013
2014 public void visitNewClass(JCNewClass tree) {
2015 // Enclosing instances or anonymous classes should have been eliminated
2016 // by now.
2017 Assert.check(tree.encl == null && tree.def == null);
2018 setTypeAnnotationPositions(tree.pos);
2019
2020 code.emitop2(new_, checkDimension(tree.pos(), tree.type), PoolWriter::putClass);
2021 code.emitop0(dup);
2022
2023 // Generate code for all arguments, where the expected types are
2024 // the parameters of the constructor's external type (that is,
2025 // any implicit outer instance appears as first parameter).
2026 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
2027
2028 items.makeMemberItem(tree.constructor, true).invoke();
2029 result = items.makeStackItem(tree.type);
2030 }
2031
2032 public void visitNewArray(JCNewArray tree) {
2033 setTypeAnnotationPositions(tree.pos);
2034
2035 if (tree.elems != null) {
2036 Type elemtype = types.elemtype(tree.type);
2037 loadIntConst(tree.elems.length());
2038 Item arr = makeNewArray(tree.pos(), tree.type, 1);
2039 int i = 0;
2040 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
2041 arr.duplicate();
2042 loadIntConst(i);
2043 i++;
2044 genExpr(l.head, elemtype).load();
2045 items.makeIndexedItem(elemtype).store();
2046 }
2047 result = arr;
2048 } else {
2049 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
2050 genExpr(l.head, syms.intType).load();
2051 }
2052 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
2053 }
2054 }
2055 //where
2056 /** Generate code to create an array with given element type and number
2057 * of dimensions.
2058 */
2059 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
2060 Type elemtype = types.elemtype(type);
2061 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
2062 log.error(pos, Errors.LimitDimensions);
2063 nerrs++;
2064 }
2065 int elemcode = Code.arraycode(elemtype);
2066 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
2067 code.emitAnewarray(makeRef(pos, elemtype), type);
2068 } else if (elemcode == 1) {
2069 code.emitMultianewarray(ndims, makeRef(pos, type), type);
2070 } else {
2071 code.emitNewarray(elemcode, type);
2072 }
2073 return items.makeStackItem(type);
2074 }
2075
2076 public void visitParens(JCParens tree) {
2077 result = genExpr(tree.expr, tree.expr.type);
2078 }
2079
2080 public void visitAssign(JCAssign tree) {
2081 Item l = genExpr(tree.lhs, tree.lhs.type);
2082 genExpr(tree.rhs, tree.lhs.type).load();
2083 if (tree.rhs.type.hasTag(BOT)) {
2084 /* This is just a case of widening reference conversion that per 5.1.5 simply calls
2085 for "regarding a reference as having some other type in a manner that can be proved
2086 correct at compile time."
2087 */
2088 code.state.forceStackTop(tree.lhs.type);
2089 }
2090 result = items.makeAssignItem(l);
2091 }
2092
2093 public void visitAssignop(JCAssignOp tree) {
2094 OperatorSymbol operator = tree.operator;
2095 Item l;
2096 if (operator.opcode == string_add) {
2097 l = concat.makeConcat(tree);
2098 } else {
2099 // Generate code for first expression
2100 l = genExpr(tree.lhs, tree.lhs.type);
2101
2102 // If we have an increment of -32768 to +32767 of a local
2103 // int variable we can use an incr instruction instead of
2104 // proceeding further.
2105 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
2106 l instanceof LocalItem localItem &&
2107 tree.lhs.type.getTag().isSubRangeOf(INT) &&
2108 tree.rhs.type.getTag().isSubRangeOf(INT) &&
2109 tree.rhs.type.constValue() != null) {
2110 int ival = ((Number) tree.rhs.type.constValue()).intValue();
2111 if (tree.hasTag(MINUS_ASG)) ival = -ival;
2112 localItem.incr(ival);
2113 result = l;
2114 return;
2115 }
2116 // Otherwise, duplicate expression, load one copy
2117 // and complete binary operation.
2118 l.duplicate();
2119 l.coerce(operator.type.getParameterTypes().head).load();
2120 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
2121 }
2122 result = items.makeAssignItem(l);
2123 }
2124
2125 public void visitUnary(JCUnary tree) {
2126 OperatorSymbol operator = tree.operator;
2127 if (tree.hasTag(NOT)) {
2128 CondItem od = genCond(tree.arg, false);
2129 result = od.negate();
2130 } else {
2131 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
2132 switch (tree.getTag()) {
2133 case POS:
2134 result = od.load();
2135 break;
2136 case NEG:
2137 result = od.load();
2138 code.emitop0(operator.opcode);
2139 break;
2140 case COMPL:
2141 result = od.load();
2142 emitMinusOne(od.typecode);
2143 code.emitop0(operator.opcode);
2144 break;
2145 case PREINC: case PREDEC:
2146 od.duplicate();
2147 if (od instanceof LocalItem localItem &&
2148 (operator.opcode == iadd || operator.opcode == isub)) {
2149 localItem.incr(tree.hasTag(PREINC) ? 1 : -1);
2150 result = od;
2151 } else {
2152 od.load();
2153 code.emitop0(one(od.typecode));
2154 code.emitop0(operator.opcode);
2155 // Perform narrowing primitive conversion if byte,
2156 // char, or short. Fix for 4304655.
2157 if (od.typecode != INTcode &&
2158 Code.truncate(od.typecode) == INTcode)
2159 code.emitop0(int2byte + od.typecode - BYTEcode);
2160 result = items.makeAssignItem(od);
2161 }
2162 break;
2163 case POSTINC: case POSTDEC:
2164 od.duplicate();
2165 if (od instanceof LocalItem localItem &&
2166 (operator.opcode == iadd || operator.opcode == isub)) {
2167 Item res = od.load();
2168 localItem.incr(tree.hasTag(POSTINC) ? 1 : -1);
2169 result = res;
2170 } else {
2171 Item res = od.load();
2172 od.stash(od.typecode);
2173 code.emitop0(one(od.typecode));
2174 code.emitop0(operator.opcode);
2175 // Perform narrowing primitive conversion if byte,
2176 // char, or short. Fix for 4304655.
2177 if (od.typecode != INTcode &&
2178 Code.truncate(od.typecode) == INTcode)
2179 code.emitop0(int2byte + od.typecode - BYTEcode);
2180 od.store();
2181 result = res;
2182 }
2183 break;
2184 case NULLCHK:
2185 result = od.load();
2186 code.emitop0(dup);
2187 genNullCheck(tree);
2188 break;
2189 default:
2190 Assert.error();
2191 }
2192 }
2193 }
2194
2195 /** Generate a null check from the object value at stack top. */
2196 private void genNullCheck(JCTree tree) {
2197 code.statBegin(tree.pos);
2198 callMethod(tree.pos(), syms.objectsType, names.requireNonNull,
2199 List.of(syms.objectType), true);
2200 code.emitop0(pop);
2201 }
2202
2203 public void visitBinary(JCBinary tree) {
2204 OperatorSymbol operator = tree.operator;
2205 if (operator.opcode == string_add) {
2206 result = concat.makeConcat(tree);
2207 } else if (tree.hasTag(AND)) {
2208 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2209 if (!lcond.isFalse()) {
2210 Chain falseJumps = lcond.jumpFalse();
2211 code.resolve(lcond.trueJumps);
2212 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2213 result = items.
2214 makeCondItem(rcond.opcode,
2215 rcond.trueJumps,
2216 Code.mergeChains(falseJumps,
2217 rcond.falseJumps));
2218 } else {
2219 result = lcond;
2220 }
2221 } else if (tree.hasTag(OR)) {
2222 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2223 if (!lcond.isTrue()) {
2224 Chain trueJumps = lcond.jumpTrue();
2225 code.resolve(lcond.falseJumps);
2226 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2227 result = items.
2228 makeCondItem(rcond.opcode,
2229 Code.mergeChains(trueJumps, rcond.trueJumps),
2230 rcond.falseJumps);
2231 } else {
2232 result = lcond;
2233 }
2234 } else {
2235 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
2236 od.load();
2237 result = completeBinop(tree.lhs, tree.rhs, operator);
2238 }
2239 }
2240
2241
2242 /** Complete generating code for operation, with left operand
2243 * already on stack.
2244 * @param lhs The tree representing the left operand.
2245 * @param rhs The tree representing the right operand.
2246 * @param operator The operator symbol.
2247 */
2248 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2249 MethodType optype = (MethodType)operator.type;
2250 int opcode = operator.opcode;
2251 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2252 rhs.type.constValue() instanceof Number number &&
2253 number.intValue() == 0) {
2254 opcode = opcode + (ifeq - if_icmpeq);
2255 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2256 TreeInfo.isNull(rhs)) {
2257 opcode = opcode + (if_acmp_null - if_acmpeq);
2258 } else {
2259 // The expected type of the right operand is
2260 // the second parameter type of the operator, except for
2261 // shifts with long shiftcount, where we convert the opcode
2262 // to a short shift and the expected type to int.
2263 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2264 if (opcode >= ishll && opcode <= lushrl) {
2265 opcode = opcode + (ishl - ishll);
2266 rtype = syms.intType;
2267 }
2268 // Generate code for right operand and load.
2269 genExpr(rhs, rtype).load();
2270 // If there are two consecutive opcode instructions,
2271 // emit the first now.
2272 if (opcode >= (1 << preShift)) {
2273 code.emitop0(opcode >> preShift);
2274 opcode = opcode & 0xFF;
2275 }
2276 }
2277 if (opcode >= ifeq && opcode <= if_acmpne ||
2278 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2279 return items.makeCondItem(opcode);
2280 } else {
2281 code.emitop0(opcode);
2282 return items.makeStackItem(optype.restype);
2283 }
2284 }
2285
2286 public void visitTypeCast(JCTypeCast tree) {
2287 result = genExpr(tree.expr, tree.clazz.type).load();
2288 setTypeAnnotationPositions(tree.pos);
2289 // Additional code is only needed if we cast to a reference type
2290 // which is not statically a supertype of the expression's type.
2291 // For basic types, the coerce(...) in genExpr(...) will do
2292 // the conversion.
2293 if (!tree.clazz.type.isPrimitive() &&
2294 !types.isSameType(tree.expr.type, tree.clazz.type) &&
2295 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2296 code.emitop2(checkcast, checkDimension(tree.pos(), tree.clazz.type), PoolWriter::putClass);
2297 }
2298 }
2299
2300 public void visitWildcard(JCWildcard tree) {
2301 throw new AssertionError(this.getClass().getName());
2302 }
2303
2304 public void visitTypeTest(JCInstanceOf tree) {
2305 genExpr(tree.expr, tree.expr.type).load();
2306 setTypeAnnotationPositions(tree.pos);
2307 code.emitop2(instanceof_, makeRef(tree.pos(), tree.pattern.type));
2308 result = items.makeStackItem(syms.booleanType);
2309 }
2310
2311 public void visitIndexed(JCArrayAccess tree) {
2312 genExpr(tree.indexed, tree.indexed.type).load();
2313 genExpr(tree.index, syms.intType).load();
2314 result = items.makeIndexedItem(tree.type);
2315 }
2316
2317 public void visitIdent(JCIdent tree) {
2318 Symbol sym = tree.sym;
2319 if (tree.name == names._this || tree.name == names._super) {
2320 Item res = tree.name == names._this
2321 ? items.makeThisItem()
2322 : items.makeSuperItem();
2323 if (sym.kind == MTH) {
2324 // Generate code to address the constructor.
2325 res.load();
2326 res = items.makeMemberItem(sym, true);
2327 }
2328 result = res;
2329 } else if (isInvokeDynamic(sym) || isConstantDynamic(sym)) {
2330 if (isConstantDynamic(sym)) {
2331 setTypeAnnotationPositions(tree.pos);
2332 }
2333 result = items.makeDynamicItem(sym);
2334 } else if (sym.kind == VAR && (sym.owner.kind == MTH || sym.owner.kind == VAR)) {
2335 result = items.makeLocalItem((VarSymbol)sym);
2336 } else if ((sym.flags() & STATIC) != 0) {
2337 if (!isAccessSuper(env.enclMethod))
2338 sym = binaryQualifier(sym, env.enclClass.type);
2339 result = items.makeStaticItem(sym);
2340 } else {
2341 items.makeThisItem().load();
2342 sym = binaryQualifier(sym, env.enclClass.type);
2343 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym));
2344 }
2345 }
2346
2347 //where
2348 private boolean nonVirtualForPrivateAccess(Symbol sym) {
2349 boolean useVirtual = target.hasVirtualPrivateInvoke() &&
2350 !disableVirtualizedPrivateInvoke;
2351 return !useVirtual && ((sym.flags() & PRIVATE) != 0);
2352 }
2353
2354 public void visitSelect(JCFieldAccess tree) {
2355 Symbol sym = tree.sym;
2356
2357 if (tree.name == names._class) {
2358 code.emitLdc((LoadableConstant)checkDimension(tree.pos(), tree.selected.type));
2359 result = items.makeStackItem(pt);
2360 return;
2361 }
2362
2363 Symbol ssym = TreeInfo.symbol(tree.selected);
2364
2365 // Are we selecting via super?
2366 boolean selectSuper =
2367 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2368
2369 // Are we accessing a member of the superclass in an access method
2370 // resulting from a qualified super?
2371 boolean accessSuper = isAccessSuper(env.enclMethod);
2372
2373 Item base = (selectSuper)
2374 ? items.makeSuperItem()
2375 : genExpr(tree.selected, tree.selected.type);
2376
2377 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2378 // We are seeing a variable that is constant but its selecting
2379 // expression is not.
2380 if ((sym.flags() & STATIC) != 0) {
2381 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2382 base = base.load();
2383 base.drop();
2384 } else {
2385 base.load();
2386 genNullCheck(tree.selected);
2387 }
2388 result = items.
2389 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2390 } else {
2391 if (isInvokeDynamic(sym)) {
2392 result = items.makeDynamicItem(sym);
2393 return;
2394 } else {
2395 sym = binaryQualifier(sym, tree.selected.type);
2396 }
2397 if ((sym.flags() & STATIC) != 0) {
2398 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2399 base = base.load();
2400 base.drop();
2401 result = items.makeStaticItem(sym);
2402 } else {
2403 base.load();
2404 if (sym == syms.lengthVar) {
2405 code.emitop0(arraylength);
2406 result = items.makeStackItem(syms.intType);
2407 } else {
2408 result = items.
2409 makeMemberItem(sym,
2410 nonVirtualForPrivateAccess(sym) ||
2411 selectSuper || accessSuper);
2412 }
2413 }
2414 }
2415 }
2416
2417 public boolean isInvokeDynamic(Symbol sym) {
2418 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
2419 }
2420
2421 public void visitLiteral(JCLiteral tree) {
2422 if (tree.type.hasTag(BOT)) {
2423 code.emitop0(aconst_null);
2424 result = items.makeStackItem(tree.type);
2425 }
2426 else
2427 result = items.makeImmediateItem(tree.type, tree.value);
2428 }
2429
2430 public void visitLetExpr(LetExpr tree) {
2431 code.resolvePending();
2432
2433 int limit = code.nextreg;
2434 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
2435 try {
2436 genStats(tree.defs, env);
2437 } finally {
2438 code.setLetExprStackPos(prevLetExprStart);
2439 }
2440 result = genExpr(tree.expr, tree.expr.type).load();
2441 code.endScopes(limit);
2442 }
2443
2444 private void generateReferencesToPrunedTree(ClassSymbol classSymbol) {
2445 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
2446 if (prunedInfo != null) {
2447 for (JCTree prunedTree: prunedInfo) {
2448 prunedTree.accept(classReferenceVisitor);
2449 }
2450 }
2451 }
2452
2453 /* ************************************************************************
2454 * main method
2455 *************************************************************************/
2456
2457 /** Generate code for a class definition.
2458 * @param env The attribution environment that belongs to the
2459 * outermost class containing this class definition.
2460 * We need this for resolving some additional symbols.
2461 * @param cdef The tree representing the class definition.
2462 * @return True if code is generated with no errors.
2463 */
2464 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2465 try {
2466 attrEnv = env;
2467 ClassSymbol c = cdef.sym;
2468 this.toplevel = env.toplevel;
2469 this.endPosTable = toplevel.endPositions;
2470 /* method normalizeDefs() can add references to external classes into the constant pool
2471 */
2472 cdef.defs = normalizeDefs(cdef.defs, c);
2473 generateReferencesToPrunedTree(c);
2474 Env<GenContext> localEnv = new Env<>(cdef, new GenContext());
2475 localEnv.toplevel = env.toplevel;
2476 localEnv.enclClass = cdef;
2477
2478 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2479 genDef(l.head, localEnv);
2480 }
2481 if (poolWriter.size() > PoolWriter.MAX_ENTRIES) {
2482 log.error(cdef.pos(), Errors.LimitPool);
2483 nerrs++;
2484 }
2485 if (nerrs != 0) {
2486 // if errors, discard code
2487 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2488 if (l.head.hasTag(METHODDEF))
2489 ((JCMethodDecl) l.head).sym.code = null;
2490 }
2491 }
2492 cdef.defs = List.nil(); // discard trees
2493 return nerrs == 0;
2494 } finally {
2495 // note: this method does NOT support recursion.
2496 attrEnv = null;
2497 this.env = null;
2498 toplevel = null;
2499 endPosTable = null;
2500 nerrs = 0;
2501 qualifiedSymbolCache.clear();
2502 }
2503 }
2504
2505 /* ************************************************************************
2506 * Auxiliary classes
2507 *************************************************************************/
2508
2509 /** An abstract class for finalizer generation.
2510 */
2511 abstract class GenFinalizer {
2512 /** Generate code to clean up when unwinding. */
2513 abstract void gen();
2514
2515 /** Generate code to clean up at last. */
2516 abstract void genLast();
2517
2518 /** Does this finalizer have some nontrivial cleanup to perform? */
2519 boolean hasFinalizer() { return true; }
2520
2521 /** Should be invoked after the try's body has been visited. */
2522 void afterBody() {}
2523 }
2524
2525 /** code generation contexts,
2526 * to be used as type parameter for environments.
2527 */
2528 final class GenContext {
2529
2530 /**
2531 * The top defined local variables for exit or continue branches to merge into.
2532 * It may contain uninitialized variables to be initialized by branched code,
2533 * so we cannot use Code.State.defined bits.
2534 */
2535 final int limit;
2536
2537 /** A chain for all unresolved jumps that exit the current environment.
2538 */
2539 Chain exit = null;
2540
2541 /** A chain for all unresolved jumps that continue in the
2542 * current environment.
2543 */
2544 Chain cont = null;
2545
2546 /** A closure that generates the finalizer of the current environment.
2547 * Only set for Synchronized and Try contexts.
2548 */
2549 GenFinalizer finalize = null;
2550
2551 /** Is this a switch statement? If so, allocate registers
2552 * even when the variable declaration is unreachable.
2553 */
2554 boolean isSwitch = false;
2555
2556 /** A list buffer containing all gaps in the finalizer range,
2557 * where a catch all exception should not apply.
2558 */
2559 ListBuffer<Integer> gaps = null;
2560
2561 GenContext() {
2562 var code = Gen.this.code;
2563 this.limit = code == null ? 0 : code.nextreg;
2564 }
2565
2566 /** Add given chain to exit chain.
2567 */
2568 void addExit(Chain c) {
2569 if (c != null) {
2570 c.state.defined.excludeFrom(limit);
2571 }
2572 exit = Code.mergeChains(c, exit);
2573 }
2574
2575 /** Add given chain to cont chain.
2576 */
2577 void addCont(Chain c) {
2578 if (c != null) {
2579 c.state.defined.excludeFrom(limit);
2580 }
2581 cont = Code.mergeChains(c, cont);
2582 }
2583 }
2584
2585 record PatternMatchingCatchConfiguration(Set<JCMethodInvocation> invocations,
2586 ListBuffer<int[]> ranges,
2587 JCCatch handler,
2588 State startState) {
2589 public PatternMatchingCatchConfiguration restart(State newState) {
2590 return new PatternMatchingCatchConfiguration(invocations(),
2591 new ListBuffer<int[]>(),
2592 handler(),
2593 newState);
2594 }
2595 }
2596 }