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 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.endpos = 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.endpos == Position.NOPOS)
557 md.body.endpos = 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 Set<JCMethodInvocation> prevInvocationsWithPatternMatchingCatch = invocationsWithPatternMatchingCatch;
1091 ListBuffer<int[]> prevRanges = patternMatchingInvocationRanges;
1092 State startState = code.state.dup();
1093 try {
1094 invocationsWithPatternMatchingCatch = tree.patternMatchingCatch.calls2Handle();
1095 patternMatchingInvocationRanges = new ListBuffer<>();
1096 internalVisitBlock(tree);
1097 } finally {
1098 Chain skipCatch = code.branch(goto_);
1099 JCCatch handler = tree.patternMatchingCatch.handler();
1100 code.entryPoint(startState, handler.param.sym.type);
1101 genPatternMatchingCatch(handler, env, patternMatchingInvocationRanges.toList());
1102 code.resolve(skipCatch);
1103 invocationsWithPatternMatchingCatch = prevInvocationsWithPatternMatchingCatch;
1104 patternMatchingInvocationRanges = prevRanges;
1105 }
1106 }
1107
1108 private void internalVisitBlock(JCBlock tree) {
1109 int limit = code.nextreg;
1110 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1111 genStats(tree.stats, localEnv);
1112 // End the scope of all block-local variables in variable info.
1113 if (!env.tree.hasTag(METHODDEF)) {
1114 code.statBegin(tree.endpos);
1115 code.endScopes(limit);
1116 code.pendingStatPos = Position.NOPOS;
1117 }
1118 }
1119
1120 public void visitDoLoop(JCDoWhileLoop tree) {
1121 genLoop(tree, tree.body, tree.cond, List.nil(), false);
1122 }
1123
1124 public void visitWhileLoop(JCWhileLoop tree) {
1125 genLoop(tree, tree.body, tree.cond, List.nil(), true);
1126 }
1127
1128 public void visitForLoop(JCForLoop tree) {
1129 int limit = code.nextreg;
1130 genStats(tree.init, env);
1131 genLoop(tree, tree.body, tree.cond, tree.step, true);
1132 code.endScopes(limit);
1133 }
1134 //where
1135 /** Generate code for a loop.
1136 * @param loop The tree representing the loop.
1137 * @param body The loop's body.
1138 * @param cond The loop's controlling condition.
1139 * @param step "Step" statements to be inserted at end of
1140 * each iteration.
1141 * @param testFirst True if the loop test belongs before the body.
1142 */
1143 private void genLoop(JCStatement loop,
1144 JCStatement body,
1145 JCExpression cond,
1146 List<JCExpressionStatement> step,
1147 boolean testFirst) {
1148 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1149 int startpc = code.entryPoint();
1150 if (testFirst) { //while or for loop
1151 CondItem c;
1152 if (cond != null) {
1153 code.statBegin(cond.pos);
1154 Assert.check(code.isStatementStart());
1155 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1156 } else {
1157 c = items.makeCondItem(goto_);
1158 }
1159 Chain loopDone = c.jumpFalse();
1160 code.resolve(c.trueJumps);
1161 Assert.check(code.isStatementStart());
1162 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1163 code.resolve(loopEnv.info.cont);
1164 genStats(step, loopEnv);
1165 code.resolve(code.branch(goto_), startpc);
1166 code.resolve(loopDone);
1167 } else {
1168 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1169 code.resolve(loopEnv.info.cont);
1170 genStats(step, loopEnv);
1171 if (code.isAlive()) {
1172 CondItem c;
1173 if (cond != null) {
1174 code.statBegin(cond.pos);
1175 Assert.check(code.isStatementStart());
1176 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1177 } else {
1178 c = items.makeCondItem(goto_);
1179 }
1180 code.resolve(c.jumpTrue(), startpc);
1181 Assert.check(code.isStatementStart());
1182 code.resolve(c.falseJumps);
1183 }
1184 }
1185 Chain exit = loopEnv.info.exit;
1186 if (exit != null) {
1187 code.resolve(exit);
1188 exit.state.defined.excludeFrom(code.nextreg);
1189 }
1190 }
1191
1192 public void visitForeachLoop(JCEnhancedForLoop tree) {
1193 throw new AssertionError(); // should have been removed by Lower.
1194 }
1195
1196 public void visitLabelled(JCLabeledStatement tree) {
1197 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1198 genStat(tree.body, localEnv, CRT_STATEMENT);
1199 Chain exit = localEnv.info.exit;
1200 if (exit != null) {
1201 code.resolve(exit);
1202 exit.state.defined.excludeFrom(code.nextreg);
1203 }
1204 }
1205
1206 public void visitSwitch(JCSwitch tree) {
1207 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1208 }
1209
1210 @Override
1211 public void visitSwitchExpression(JCSwitchExpression tree) {
1212 code.resolvePending();
1213 boolean prevInCondSwitchExpression = inCondSwitchExpression;
1214 try {
1215 inCondSwitchExpression = false;
1216 doHandleSwitchExpression(tree);
1217 } finally {
1218 inCondSwitchExpression = prevInCondSwitchExpression;
1219 }
1220 result = items.makeStackItem(pt);
1221 }
1222
1223 private void doHandleSwitchExpression(JCSwitchExpression tree) {
1224 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
1225 LocalItem prevSwitchResult = switchResult;
1226 int limit = code.nextreg;
1227 try {
1228 stackBeforeSwitchExpression = List.nil();
1229 switchResult = null;
1230 if (hasTry(tree)) {
1231 //if the switch expression contains try-catch, the catch handlers need to have
1232 //an empty stack. So stash whole stack to local variables, and restore it before
1233 //breaks:
1234 while (code.state.stacksize > 0) {
1235 Type type = code.state.peek();
1236 Name varName = names.fromString(target.syntheticNameChar() +
1237 "stack" +
1238 target.syntheticNameChar() +
1239 tree.pos +
1240 target.syntheticNameChar() +
1241 code.state.stacksize);
1242 VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type,
1243 this.env.enclMethod.sym);
1244 LocalItem item = items.new LocalItem(type, code.newLocal(var));
1245 stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item);
1246 item.store();
1247 }
1248 switchResult = makeTemp(tree.type);
1249 }
1250 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
1251 try {
1252 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1253 } finally {
1254 code.setLetExprStackPos(prevLetExprStart);
1255 }
1256 } finally {
1257 stackBeforeSwitchExpression = prevStackBeforeSwitchExpression;
1258 switchResult = prevSwitchResult;
1259 code.endScopes(limit);
1260 }
1261 }
1262 //where:
1263 private boolean hasTry(JCSwitchExpression tree) {
1264 class HasTryScanner extends TreeScanner {
1265 private boolean hasTry;
1266
1267 @Override
1268 public void visitTry(JCTry tree) {
1269 hasTry = true;
1270 }
1271
1272 @Override
1273 public void visitSynchronized(JCSynchronized tree) {
1274 hasTry = true;
1275 }
1276
1277 @Override
1278 public void visitClassDef(JCClassDecl tree) {
1279 }
1280
1281 @Override
1282 public void visitLambda(JCLambda tree) {
1283 }
1284 };
1285
1286 HasTryScanner hasTryScanner = new HasTryScanner();
1287
1288 hasTryScanner.scan(tree);
1289 return hasTryScanner.hasTry;
1290 }
1291
1292 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases,
1293 boolean patternSwitch) {
1294 int limit = code.nextreg;
1295 Assert.check(!selector.type.hasTag(CLASS));
1296 int switchStart = patternSwitch ? code.entryPoint() : -1;
1297 int startpcCrt = genCrt ? code.curCP() : 0;
1298 Assert.check(code.isStatementStart());
1299 Item sel = genExpr(selector, syms.intType);
1300 if (cases.isEmpty()) {
1301 // We are seeing: switch <sel> {}
1302 sel.load().drop();
1303 if (genCrt)
1304 code.crt.put(TreeInfo.skipParens(selector),
1305 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1306 } else {
1307 // We are seeing a nonempty switch.
1308 sel.load();
1309 if (genCrt)
1310 code.crt.put(TreeInfo.skipParens(selector),
1311 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1312 Env<GenContext> switchEnv = env.dup(swtch, new GenContext());
1313 switchEnv.info.isSwitch = true;
1314
1315 // Compute number of labels and minimum and maximum label values.
1316 // For each case, store its label in an array.
1317 int lo = Integer.MAX_VALUE; // minimum label.
1318 int hi = Integer.MIN_VALUE; // maximum label.
1319 int nlabels = 0; // number of labels.
1320
1321 int[] labels = new int[cases.length()]; // the label array.
1322 int defaultIndex = -1; // the index of the default clause.
1323
1324 List<JCCase> l = cases;
1325 for (int i = 0; i < labels.length; i++) {
1326 if (l.head.labels.head instanceof JCConstantCaseLabel constLabel) {
1327 Assert.check(l.head.labels.size() == 1);
1328 int val = ((Number) constLabel.expr.type.constValue()).intValue();
1329 labels[i] = val;
1330 if (val < lo) lo = val;
1331 if (hi < val) hi = val;
1332 nlabels++;
1333 } else {
1334 Assert.check(defaultIndex == -1);
1335 defaultIndex = i;
1336 }
1337 l = l.tail;
1338 }
1339
1340 // Determine whether to issue a tableswitch or a lookupswitch
1341 // instruction.
1342 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1343 long table_time_cost = 3; // comparisons
1344 long lookup_space_cost = 3 + 2 * (long) nlabels;
1345 long lookup_time_cost = nlabels;
1346 int opcode =
1347 nlabels > 0 &&
1348 table_space_cost + 3 * table_time_cost <=
1349 lookup_space_cost + 3 * lookup_time_cost
1350 ?
1351 tableswitch : lookupswitch;
1352
1353 int startpc = code.curCP(); // the position of the selector operation
1354 code.emitop0(opcode);
1355 code.align(4);
1356 int tableBase = code.curCP(); // the start of the jump table
1357 int[] offsets = null; // a table of offsets for a lookupswitch
1358 code.emit4(-1); // leave space for default offset
1359 if (opcode == tableswitch) {
1360 code.emit4(lo); // minimum label
1361 code.emit4(hi); // maximum label
1362 for (long i = lo; i <= hi; i++) { // leave space for jump table
1363 code.emit4(-1);
1364 }
1365 } else {
1366 code.emit4(nlabels); // number of labels
1367 for (int i = 0; i < nlabels; i++) {
1368 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1369 }
1370 offsets = new int[labels.length];
1371 }
1372 Code.State stateSwitch = code.state.dup();
1373 code.markDead();
1374
1375 // For each case do:
1376 l = cases;
1377 for (int i = 0; i < labels.length; i++) {
1378 JCCase c = l.head;
1379 l = l.tail;
1380
1381 int pc = code.entryPoint(stateSwitch);
1382 // Insert offset directly into code or else into the
1383 // offsets table.
1384 if (i != defaultIndex) {
1385 if (opcode == tableswitch) {
1386 code.put4(
1387 tableBase + 4 * (labels[i] - lo + 3),
1388 pc - startpc);
1389 } else {
1390 offsets[i] = pc - startpc;
1391 }
1392 } else {
1393 code.put4(tableBase, pc - startpc);
1394 }
1395
1396 // Generate code for the statements in this case.
1397 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1398 }
1399
1400 if (switchEnv.info.cont != null) {
1401 Assert.check(patternSwitch);
1402 code.resolve(switchEnv.info.cont, switchStart);
1403 }
1404
1405 // Resolve all breaks.
1406 Chain exit = switchEnv.info.exit;
1407 if (exit != null) {
1408 code.resolve(exit);
1409 exit.state.defined.excludeFrom(limit);
1410 }
1411
1412 // If we have not set the default offset, we do so now.
1413 if (code.get4(tableBase) == -1) {
1414 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1415 }
1416
1417 if (opcode == tableswitch) {
1418 // Let any unfilled slots point to the default case.
1419 int defaultOffset = code.get4(tableBase);
1420 for (long i = lo; i <= hi; i++) {
1421 int t = (int)(tableBase + 4 * (i - lo + 3));
1422 if (code.get4(t) == -1)
1423 code.put4(t, defaultOffset);
1424 }
1425 } else {
1426 // Sort non-default offsets and copy into lookup table.
1427 if (defaultIndex >= 0)
1428 for (int i = defaultIndex; i < labels.length - 1; i++) {
1429 labels[i] = labels[i+1];
1430 offsets[i] = offsets[i+1];
1431 }
1432 if (nlabels > 0)
1433 qsort2(labels, offsets, 0, nlabels - 1);
1434 for (int i = 0; i < nlabels; i++) {
1435 int caseidx = tableBase + 8 * (i + 1);
1436 code.put4(caseidx, labels[i]);
1437 code.put4(caseidx + 4, offsets[i]);
1438 }
1439 }
1440
1441 if (swtch instanceof JCSwitchExpression) {
1442 // Emit line position for the end of a switch expression
1443 code.statBegin(TreeInfo.endPos(swtch));
1444 }
1445 }
1446 code.endScopes(limit);
1447 }
1448 //where
1449 /** Sort (int) arrays of keys and values
1450 */
1451 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1452 int i = lo;
1453 int j = hi;
1454 int pivot = keys[(i+j)/2];
1455 do {
1456 while (keys[i] < pivot) i++;
1457 while (pivot < keys[j]) j--;
1458 if (i <= j) {
1459 int temp1 = keys[i];
1460 keys[i] = keys[j];
1461 keys[j] = temp1;
1462 int temp2 = values[i];
1463 values[i] = values[j];
1464 values[j] = temp2;
1465 i++;
1466 j--;
1467 }
1468 } while (i <= j);
1469 if (lo < j) qsort2(keys, values, lo, j);
1470 if (i < hi) qsort2(keys, values, i, hi);
1471 }
1472
1473 public void visitSynchronized(JCSynchronized tree) {
1474 int limit = code.nextreg;
1475 // Generate code to evaluate lock and save in temporary variable.
1476 final LocalItem lockVar = makeTemp(syms.objectType);
1477 Assert.check(code.isStatementStart());
1478 genExpr(tree.lock, tree.lock.type).load().duplicate();
1479 lockVar.store();
1480
1481 // Generate code to enter monitor.
1482 code.emitop0(monitorenter);
1483 code.state.lock(lockVar.reg);
1484
1485 // Generate code for a try statement with given body, no catch clauses
1486 // in a new environment with the "exit-monitor" operation as finalizer.
1487 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1488 syncEnv.info.finalize = new GenFinalizer() {
1489 void gen() {
1490 genLast();
1491 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1492 syncEnv.info.gaps.append(code.curCP());
1493 }
1494 void genLast() {
1495 if (code.isAlive()) {
1496 lockVar.load();
1497 code.emitop0(monitorexit);
1498 code.state.unlock(lockVar.reg);
1499 }
1500 }
1501 };
1502 syncEnv.info.gaps = new ListBuffer<>();
1503 genTry(tree.body, List.nil(), syncEnv);
1504 code.endScopes(limit);
1505 }
1506
1507 public void visitTry(final JCTry tree) {
1508 // Generate code for a try statement with given body and catch clauses,
1509 // in a new environment which calls the finally block if there is one.
1510 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1511 final Env<GenContext> oldEnv = env;
1512 tryEnv.info.finalize = new GenFinalizer() {
1513 void gen() {
1514 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1515 tryEnv.info.gaps.append(code.curCP());
1516 genLast();
1517 }
1518 void genLast() {
1519 if (tree.finalizer != null)
1520 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1521 }
1522 boolean hasFinalizer() {
1523 return tree.finalizer != null;
1524 }
1525
1526 @Override
1527 void afterBody() {
1528 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1529 //for body-only finally, remove the GenFinalizer after try body
1530 //so that the finally is not generated to catch bodies:
1531 tryEnv.info.finalize = null;
1532 }
1533 }
1534
1535 };
1536 tryEnv.info.gaps = new ListBuffer<>();
1537 genTry(tree.body, tree.catchers, tryEnv);
1538 }
1539 //where
1540 /** Generate code for a try or synchronized statement
1541 * @param body The body of the try or synchronized statement.
1542 * @param catchers The list of catch clauses.
1543 * @param env The current environment of the body.
1544 */
1545 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1546 int limit = code.nextreg;
1547 int startpc = code.curCP();
1548 Code.State stateTry = code.state.dup();
1549 genStat(body, env, CRT_BLOCK);
1550 int endpc = code.curCP();
1551 List<Integer> gaps = env.info.gaps.toList();
1552 code.statBegin(TreeInfo.endPos(body));
1553 genFinalizer(env);
1554 code.statBegin(TreeInfo.endPos(env.tree));
1555 Chain exitChain;
1556 boolean actualTry = env.tree.hasTag(TRY);
1557 if (startpc == endpc && actualTry) {
1558 exitChain = code.branch(dontgoto);
1559 } else {
1560 exitChain = code.branch(goto_);
1561 }
1562 endFinalizerGap(env);
1563 env.info.finalize.afterBody();
1564 boolean hasFinalizer =
1565 env.info.finalize != null &&
1566 env.info.finalize.hasFinalizer();
1567 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1568 // start off with exception on stack
1569 code.entryPoint(stateTry, l.head.param.sym.type);
1570 genCatch(l.head, env, startpc, endpc, gaps);
1571 genFinalizer(env);
1572 if (hasFinalizer || l.tail.nonEmpty()) {
1573 code.statBegin(TreeInfo.endPos(env.tree));
1574 exitChain = Code.mergeChains(exitChain,
1575 code.branch(goto_));
1576 }
1577 endFinalizerGap(env);
1578 }
1579 if (hasFinalizer && (startpc != endpc || !actualTry)) {
1580 // Create a new register segment to avoid allocating
1581 // the same variables in finalizers and other statements.
1582 code.newRegSegment();
1583
1584 // Add a catch-all clause.
1585
1586 // start off with exception on stack
1587 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1588
1589 // Register all exception ranges for catch all clause.
1590 // The range of the catch all clause is from the beginning
1591 // of the try or synchronized block until the present
1592 // code pointer excluding all gaps in the current
1593 // environment's GenContext.
1594 int startseg = startpc;
1595 while (env.info.gaps.nonEmpty()) {
1596 int endseg = env.info.gaps.next().intValue();
1597 registerCatch(body.pos(), startseg, endseg,
1598 catchallpc, 0);
1599 startseg = env.info.gaps.next().intValue();
1600 }
1601 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1602 code.markStatBegin();
1603
1604 Item excVar = makeTemp(syms.throwableType);
1605 excVar.store();
1606 genFinalizer(env);
1607 code.resolvePending();
1608 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1609 code.markStatBegin();
1610
1611 excVar.load();
1612 registerCatch(body.pos(), startseg,
1613 env.info.gaps.next().intValue(),
1614 catchallpc, 0);
1615 code.emitop0(athrow);
1616 code.markDead();
1617
1618 // If there are jsr's to this finalizer, ...
1619 if (env.info.cont != null) {
1620 // Resolve all jsr's.
1621 code.resolve(env.info.cont);
1622
1623 // Mark statement line number
1624 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1625 code.markStatBegin();
1626
1627 // Save return address.
1628 LocalItem retVar = makeTemp(syms.throwableType);
1629 retVar.store();
1630
1631 // Generate finalizer code.
1632 env.info.finalize.genLast();
1633
1634 // Return.
1635 code.emitop1w(ret, retVar.reg);
1636 code.markDead();
1637 }
1638 }
1639 // Resolve all breaks.
1640 code.resolve(exitChain);
1641
1642 code.endScopes(limit);
1643 }
1644
1645 /** Generate code for a catch clause.
1646 * @param tree The catch clause.
1647 * @param env The environment current in the enclosing try.
1648 * @param startpc Start pc of try-block.
1649 * @param endpc End pc of try-block.
1650 */
1651 void genCatch(JCCatch tree,
1652 Env<GenContext> env,
1653 int startpc, int endpc,
1654 List<Integer> gaps) {
1655 if (startpc != endpc) {
1656 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs
1657 = catchTypesWithAnnotations(tree);
1658 while (gaps.nonEmpty()) {
1659 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1660 JCExpression subCatch = subCatch1.snd;
1661 int catchType = makeRef(tree.pos(), subCatch.type);
1662 int end = gaps.head.intValue();
1663 registerCatch(tree.pos(),
1664 startpc, end, code.curCP(),
1665 catchType);
1666 for (Attribute.TypeCompound tc : subCatch1.fst) {
1667 tc.position.setCatchInfo(catchType, startpc);
1668 }
1669 }
1670 gaps = gaps.tail;
1671 startpc = gaps.head.intValue();
1672 gaps = gaps.tail;
1673 }
1674 if (startpc < endpc) {
1675 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1676 JCExpression subCatch = subCatch1.snd;
1677 int catchType = makeRef(tree.pos(), subCatch.type);
1678 registerCatch(tree.pos(),
1679 startpc, endpc, code.curCP(),
1680 catchType);
1681 for (Attribute.TypeCompound tc : subCatch1.fst) {
1682 tc.position.setCatchInfo(catchType, startpc);
1683 }
1684 }
1685 }
1686 genCatchBlock(tree, env);
1687 }
1688 }
1689 void genPatternMatchingCatch(JCCatch tree,
1690 Env<GenContext> env,
1691 List<int[]> ranges) {
1692 for (int[] range : ranges) {
1693 JCExpression subCatch = tree.param.vartype;
1694 int catchType = makeRef(tree.pos(), subCatch.type);
1695 registerCatch(tree.pos(),
1696 range[0], range[1], code.curCP(),
1697 catchType);
1698 }
1699 genCatchBlock(tree, env);
1700 }
1701 void genCatchBlock(JCCatch tree, Env<GenContext> env) {
1702 VarSymbol exparam = tree.param.sym;
1703 code.statBegin(tree.pos);
1704 code.markStatBegin();
1705 int limit = code.nextreg;
1706 code.newLocal(exparam);
1707 items.makeLocalItem(exparam).store();
1708 code.statBegin(TreeInfo.firstStatPos(tree.body));
1709 genStat(tree.body, env, CRT_BLOCK);
1710 code.endScopes(limit);
1711 code.statBegin(TreeInfo.endPos(tree.body));
1712 }
1713 // where
1714 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) {
1715 return TreeInfo.isMultiCatch(tree) ?
1716 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) :
1717 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype));
1718 }
1719 // where
1720 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) {
1721 List<JCExpression> alts = tree.alternatives;
1722 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head));
1723 alts = alts.tail;
1724
1725 while(alts != null && alts.head != null) {
1726 JCExpression alt = alts.head;
1727 if (alt instanceof JCAnnotatedType annotatedType) {
1728 res = res.prepend(new Pair<>(annotate.fromAnnotations(annotatedType.annotations), alt));
1729 } else {
1730 res = res.prepend(new Pair<>(List.nil(), alt));
1731 }
1732 alts = alts.tail;
1733 }
1734 return res.reverse();
1735 }
1736
1737 /** Register a catch clause in the "Exceptions" code-attribute.
1738 */
1739 void registerCatch(DiagnosticPosition pos,
1740 int startpc, int endpc,
1741 int handler_pc, int catch_type) {
1742 char startpc1 = (char)startpc;
1743 char endpc1 = (char)endpc;
1744 char handler_pc1 = (char)handler_pc;
1745 if (startpc1 == startpc &&
1746 endpc1 == endpc &&
1747 handler_pc1 == handler_pc) {
1748 code.addCatch(startpc1, endpc1, handler_pc1,
1749 (char)catch_type);
1750 } else {
1751 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1752 nerrs++;
1753 }
1754 }
1755
1756 public void visitIf(JCIf tree) {
1757 int limit = code.nextreg;
1758 Chain thenExit = null;
1759 Assert.check(code.isStatementStart());
1760 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1761 CRT_FLOW_CONTROLLER);
1762 Chain elseChain = c.jumpFalse();
1763 Assert.check(code.isStatementStart());
1764 if (!c.isFalse()) {
1765 code.resolve(c.trueJumps);
1766 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1767 thenExit = code.branch(goto_);
1768 }
1769 if (elseChain != null) {
1770 code.resolve(elseChain);
1771 if (tree.elsepart != null) {
1772 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1773 }
1774 }
1775 code.resolve(thenExit);
1776 code.endScopes(limit);
1777 Assert.check(code.isStatementStart());
1778 }
1779
1780 public void visitExec(JCExpressionStatement tree) {
1781 // Optimize x++ to ++x and x-- to --x.
1782 JCExpression e = tree.expr;
1783 switch (e.getTag()) {
1784 case POSTINC:
1785 ((JCUnary) e).setTag(PREINC);
1786 break;
1787 case POSTDEC:
1788 ((JCUnary) e).setTag(PREDEC);
1789 break;
1790 }
1791 Assert.check(code.isStatementStart());
1792 genExpr(tree.expr, tree.expr.type).drop();
1793 Assert.check(code.isStatementStart());
1794 }
1795
1796 public void visitBreak(JCBreak tree) {
1797 Assert.check(code.isStatementStart());
1798 final Env<GenContext> targetEnv = unwindBreak(tree.target);
1799 targetEnv.info.addExit(code.branch(goto_));
1800 endFinalizerGaps(env, targetEnv);
1801 }
1802
1803 public void visitYield(JCYield tree) {
1804 Assert.check(code.isStatementStart());
1805 final Env<GenContext> targetEnv;
1806 if (inCondSwitchExpression) {
1807 CondItem value = genCond(tree.value, CRT_FLOW_TARGET);
1808 Chain falseJumps = value.jumpFalse();
1809
1810 code.resolve(value.trueJumps);
1811 Env<GenContext> localEnv = unwindBreak(tree.target);
1812 reloadStackBeforeSwitchExpr();
1813 Chain trueJumps = code.branch(goto_);
1814
1815 endFinalizerGaps(env, localEnv);
1816
1817 code.resolve(falseJumps);
1818 targetEnv = unwindBreak(tree.target);
1819 reloadStackBeforeSwitchExpr();
1820 falseJumps = code.branch(goto_);
1821
1822 if (switchExpressionTrueChain == null) {
1823 switchExpressionTrueChain = trueJumps;
1824 } else {
1825 switchExpressionTrueChain =
1826 Code.mergeChains(switchExpressionTrueChain, trueJumps);
1827 }
1828 if (switchExpressionFalseChain == null) {
1829 switchExpressionFalseChain = falseJumps;
1830 } else {
1831 switchExpressionFalseChain =
1832 Code.mergeChains(switchExpressionFalseChain, falseJumps);
1833 }
1834 } else {
1835 genExpr(tree.value, pt).load();
1836 if (switchResult != null)
1837 switchResult.store();
1838
1839 targetEnv = unwindBreak(tree.target);
1840
1841 if (code.isAlive()) {
1842 reloadStackBeforeSwitchExpr();
1843 if (switchResult != null)
1844 switchResult.load();
1845
1846 code.state.forceStackTop(tree.target.type);
1847 targetEnv.info.addExit(code.branch(goto_));
1848 code.markDead();
1849 }
1850 }
1851 endFinalizerGaps(env, targetEnv);
1852 }
1853 //where:
1854 /** As side-effect, might mark code as dead disabling any further emission.
1855 */
1856 private Env<GenContext> unwindBreak(JCTree target) {
1857 int tmpPos = code.pendingStatPos;
1858 Env<GenContext> targetEnv = unwind(target, env);
1859 code.pendingStatPos = tmpPos;
1860 return targetEnv;
1861 }
1862
1863 private void reloadStackBeforeSwitchExpr() {
1864 for (LocalItem li : stackBeforeSwitchExpression)
1865 li.load();
1866 }
1867
1868 public void visitContinue(JCContinue tree) {
1869 int tmpPos = code.pendingStatPos;
1870 Env<GenContext> targetEnv = unwind(tree.target, env);
1871 code.pendingStatPos = tmpPos;
1872 Assert.check(code.isStatementStart());
1873 targetEnv.info.addCont(code.branch(goto_));
1874 endFinalizerGaps(env, targetEnv);
1875 }
1876
1877 public void visitReturn(JCReturn tree) {
1878 int limit = code.nextreg;
1879 final Env<GenContext> targetEnv;
1880
1881 /* Save and then restore the location of the return in case a finally
1882 * is expanded (with unwind()) in the middle of our bytecodes.
1883 */
1884 int tmpPos = code.pendingStatPos;
1885 if (tree.expr != null) {
1886 Assert.check(code.isStatementStart());
1887 Item r = genExpr(tree.expr, pt).load();
1888 if (hasFinally(env.enclMethod, env)) {
1889 r = makeTemp(pt);
1890 r.store();
1891 }
1892 targetEnv = unwind(env.enclMethod, env);
1893 code.pendingStatPos = tmpPos;
1894 r.load();
1895 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
1896 } else {
1897 targetEnv = unwind(env.enclMethod, env);
1898 code.pendingStatPos = tmpPos;
1899 code.emitop0(return_);
1900 }
1901 endFinalizerGaps(env, targetEnv);
1902 code.endScopes(limit);
1903 }
1904
1905 public void visitThrow(JCThrow tree) {
1906 Assert.check(code.isStatementStart());
1907 genExpr(tree.expr, tree.expr.type).load();
1908 code.emitop0(athrow);
1909 Assert.check(code.isStatementStart());
1910 }
1911
1912 /* ************************************************************************
1913 * Visitor methods for expressions
1914 *************************************************************************/
1915
1916 public void visitApply(JCMethodInvocation tree) {
1917 setTypeAnnotationPositions(tree.pos);
1918 // Generate code for method.
1919 Item m = genExpr(tree.meth, methodType);
1920 // Generate code for all arguments, where the expected types are
1921 // the parameters of the method's external type (that is, any implicit
1922 // outer instance of a super(...) call appears as first parameter).
1923 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
1924 genArgs(tree.args,
1925 msym.externalType(types).getParameterTypes());
1926 if (!msym.isDynamic()) {
1927 code.statBegin(tree.pos);
1928 }
1929 if (invocationsWithPatternMatchingCatch.contains(tree)) {
1930 int start = code.curCP();
1931 result = m.invoke();
1932 patternMatchingInvocationRanges.add(new int[] {start, code.curCP()});
1933 } else {
1934 result = m.invoke();
1935 }
1936 }
1937
1938 public void visitConditional(JCConditional tree) {
1939 Chain thenExit = null;
1940 code.statBegin(tree.cond.pos);
1941 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
1942 Chain elseChain = c.jumpFalse();
1943 if (!c.isFalse()) {
1944 code.resolve(c.trueJumps);
1945 int startpc = genCrt ? code.curCP() : 0;
1946 code.statBegin(tree.truepart.pos);
1947 genExpr(tree.truepart, pt).load();
1948 code.state.forceStackTop(tree.type);
1949 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
1950 startpc, code.curCP());
1951 thenExit = code.branch(goto_);
1952 }
1953 if (elseChain != null) {
1954 code.resolve(elseChain);
1955 int startpc = genCrt ? code.curCP() : 0;
1956 code.statBegin(tree.falsepart.pos);
1957 genExpr(tree.falsepart, pt).load();
1958 code.state.forceStackTop(tree.type);
1959 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
1960 startpc, code.curCP());
1961 }
1962 code.resolve(thenExit);
1963 result = items.makeStackItem(pt);
1964 }
1965
1966 private void setTypeAnnotationPositions(int treePos) {
1967 MethodSymbol meth = code.meth;
1968 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR
1969 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT;
1970
1971 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
1972 if (ta.hasUnknownPosition())
1973 ta.tryFixPosition();
1974
1975 if (ta.position.matchesPos(treePos))
1976 ta.position.updatePosOffset(code.cp);
1977 }
1978
1979 if (!initOrClinit)
1980 return;
1981
1982 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
1983 if (ta.hasUnknownPosition())
1984 ta.tryFixPosition();
1985
1986 if (ta.position.matchesPos(treePos))
1987 ta.position.updatePosOffset(code.cp);
1988 }
1989
1990 ClassSymbol clazz = meth.enclClass();
1991 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
1992 if (!s.getKind().isField())
1993 continue;
1994
1995 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
1996 if (ta.hasUnknownPosition())
1997 ta.tryFixPosition();
1998
1999 if (ta.position.matchesPos(treePos))
2000 ta.position.updatePosOffset(code.cp);
2001 }
2002 }
2003 }
2004
2005 public void visitNewClass(JCNewClass tree) {
2006 // Enclosing instances or anonymous classes should have been eliminated
2007 // by now.
2008 Assert.check(tree.encl == null && tree.def == null);
2009 setTypeAnnotationPositions(tree.pos);
2010
2011 code.emitop2(new_, checkDimension(tree.pos(), tree.type), PoolWriter::putClass);
2012 code.emitop0(dup);
2013
2014 // Generate code for all arguments, where the expected types are
2015 // the parameters of the constructor's external type (that is,
2016 // any implicit outer instance appears as first parameter).
2017 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
2018
2019 items.makeMemberItem(tree.constructor, true).invoke();
2020 result = items.makeStackItem(tree.type);
2021 }
2022
2023 public void visitNewArray(JCNewArray tree) {
2024 setTypeAnnotationPositions(tree.pos);
2025
2026 if (tree.elems != null) {
2027 Type elemtype = types.elemtype(tree.type);
2028 loadIntConst(tree.elems.length());
2029 Item arr = makeNewArray(tree.pos(), tree.type, 1);
2030 int i = 0;
2031 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
2032 arr.duplicate();
2033 loadIntConst(i);
2034 i++;
2035 genExpr(l.head, elemtype).load();
2036 items.makeIndexedItem(elemtype).store();
2037 }
2038 result = arr;
2039 } else {
2040 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
2041 genExpr(l.head, syms.intType).load();
2042 }
2043 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
2044 }
2045 }
2046 //where
2047 /** Generate code to create an array with given element type and number
2048 * of dimensions.
2049 */
2050 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
2051 Type elemtype = types.elemtype(type);
2052 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
2053 log.error(pos, Errors.LimitDimensions);
2054 nerrs++;
2055 }
2056 int elemcode = Code.arraycode(elemtype);
2057 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
2058 code.emitAnewarray(makeRef(pos, elemtype), type);
2059 } else if (elemcode == 1) {
2060 code.emitMultianewarray(ndims, makeRef(pos, type), type);
2061 } else {
2062 code.emitNewarray(elemcode, type);
2063 }
2064 return items.makeStackItem(type);
2065 }
2066
2067 public void visitParens(JCParens tree) {
2068 result = genExpr(tree.expr, tree.expr.type);
2069 }
2070
2071 public void visitAssign(JCAssign tree) {
2072 Item l = genExpr(tree.lhs, tree.lhs.type);
2073 genExpr(tree.rhs, tree.lhs.type).load();
2074 if (tree.rhs.type.hasTag(BOT)) {
2075 /* This is just a case of widening reference conversion that per 5.1.5 simply calls
2076 for "regarding a reference as having some other type in a manner that can be proved
2077 correct at compile time."
2078 */
2079 code.state.forceStackTop(tree.lhs.type);
2080 }
2081 result = items.makeAssignItem(l);
2082 }
2083
2084 public void visitAssignop(JCAssignOp tree) {
2085 OperatorSymbol operator = tree.operator;
2086 Item l;
2087 if (operator.opcode == string_add) {
2088 l = concat.makeConcat(tree);
2089 } else {
2090 // Generate code for first expression
2091 l = genExpr(tree.lhs, tree.lhs.type);
2092
2093 // If we have an increment of -32768 to +32767 of a local
2094 // int variable we can use an incr instruction instead of
2095 // proceeding further.
2096 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
2097 l instanceof LocalItem localItem &&
2098 tree.lhs.type.getTag().isSubRangeOf(INT) &&
2099 tree.rhs.type.getTag().isSubRangeOf(INT) &&
2100 tree.rhs.type.constValue() != null) {
2101 int ival = ((Number) tree.rhs.type.constValue()).intValue();
2102 if (tree.hasTag(MINUS_ASG)) ival = -ival;
2103 localItem.incr(ival);
2104 result = l;
2105 return;
2106 }
2107 // Otherwise, duplicate expression, load one copy
2108 // and complete binary operation.
2109 l.duplicate();
2110 l.coerce(operator.type.getParameterTypes().head).load();
2111 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
2112 }
2113 result = items.makeAssignItem(l);
2114 }
2115
2116 public void visitUnary(JCUnary tree) {
2117 OperatorSymbol operator = tree.operator;
2118 if (tree.hasTag(NOT)) {
2119 CondItem od = genCond(tree.arg, false);
2120 result = od.negate();
2121 } else {
2122 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
2123 switch (tree.getTag()) {
2124 case POS:
2125 result = od.load();
2126 break;
2127 case NEG:
2128 result = od.load();
2129 code.emitop0(operator.opcode);
2130 break;
2131 case COMPL:
2132 result = od.load();
2133 emitMinusOne(od.typecode);
2134 code.emitop0(operator.opcode);
2135 break;
2136 case PREINC: case PREDEC:
2137 od.duplicate();
2138 if (od instanceof LocalItem localItem &&
2139 (operator.opcode == iadd || operator.opcode == isub)) {
2140 localItem.incr(tree.hasTag(PREINC) ? 1 : -1);
2141 result = od;
2142 } else {
2143 od.load();
2144 code.emitop0(one(od.typecode));
2145 code.emitop0(operator.opcode);
2146 // Perform narrowing primitive conversion if byte,
2147 // char, or short. Fix for 4304655.
2148 if (od.typecode != INTcode &&
2149 Code.truncate(od.typecode) == INTcode)
2150 code.emitop0(int2byte + od.typecode - BYTEcode);
2151 result = items.makeAssignItem(od);
2152 }
2153 break;
2154 case POSTINC: case POSTDEC:
2155 od.duplicate();
2156 if (od instanceof LocalItem localItem &&
2157 (operator.opcode == iadd || operator.opcode == isub)) {
2158 Item res = od.load();
2159 localItem.incr(tree.hasTag(POSTINC) ? 1 : -1);
2160 result = res;
2161 } else {
2162 Item res = od.load();
2163 od.stash(od.typecode);
2164 code.emitop0(one(od.typecode));
2165 code.emitop0(operator.opcode);
2166 // Perform narrowing primitive conversion if byte,
2167 // char, or short. Fix for 4304655.
2168 if (od.typecode != INTcode &&
2169 Code.truncate(od.typecode) == INTcode)
2170 code.emitop0(int2byte + od.typecode - BYTEcode);
2171 od.store();
2172 result = res;
2173 }
2174 break;
2175 case NULLCHK:
2176 result = od.load();
2177 code.emitop0(dup);
2178 genNullCheck(tree);
2179 break;
2180 default:
2181 Assert.error();
2182 }
2183 }
2184 }
2185
2186 /** Generate a null check from the object value at stack top. */
2187 private void genNullCheck(JCTree tree) {
2188 code.statBegin(tree.pos);
2189 callMethod(tree.pos(), syms.objectsType, names.requireNonNull,
2190 List.of(syms.objectType), true);
2191 code.emitop0(pop);
2192 }
2193
2194 public void visitBinary(JCBinary tree) {
2195 OperatorSymbol operator = tree.operator;
2196 if (operator.opcode == string_add) {
2197 result = concat.makeConcat(tree);
2198 } else if (tree.hasTag(AND)) {
2199 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2200 if (!lcond.isFalse()) {
2201 Chain falseJumps = lcond.jumpFalse();
2202 code.resolve(lcond.trueJumps);
2203 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2204 result = items.
2205 makeCondItem(rcond.opcode,
2206 rcond.trueJumps,
2207 Code.mergeChains(falseJumps,
2208 rcond.falseJumps));
2209 } else {
2210 result = lcond;
2211 }
2212 } else if (tree.hasTag(OR)) {
2213 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2214 if (!lcond.isTrue()) {
2215 Chain trueJumps = lcond.jumpTrue();
2216 code.resolve(lcond.falseJumps);
2217 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2218 result = items.
2219 makeCondItem(rcond.opcode,
2220 Code.mergeChains(trueJumps, rcond.trueJumps),
2221 rcond.falseJumps);
2222 } else {
2223 result = lcond;
2224 }
2225 } else {
2226 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
2227 od.load();
2228 result = completeBinop(tree.lhs, tree.rhs, operator);
2229 }
2230 }
2231
2232
2233 /** Complete generating code for operation, with left operand
2234 * already on stack.
2235 * @param lhs The tree representing the left operand.
2236 * @param rhs The tree representing the right operand.
2237 * @param operator The operator symbol.
2238 */
2239 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2240 MethodType optype = (MethodType)operator.type;
2241 int opcode = operator.opcode;
2242 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2243 rhs.type.constValue() instanceof Number number &&
2244 number.intValue() == 0) {
2245 opcode = opcode + (ifeq - if_icmpeq);
2246 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2247 TreeInfo.isNull(rhs)) {
2248 opcode = opcode + (if_acmp_null - if_acmpeq);
2249 } else {
2250 // The expected type of the right operand is
2251 // the second parameter type of the operator, except for
2252 // shifts with long shiftcount, where we convert the opcode
2253 // to a short shift and the expected type to int.
2254 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2255 if (opcode >= ishll && opcode <= lushrl) {
2256 opcode = opcode + (ishl - ishll);
2257 rtype = syms.intType;
2258 }
2259 // Generate code for right operand and load.
2260 genExpr(rhs, rtype).load();
2261 // If there are two consecutive opcode instructions,
2262 // emit the first now.
2263 if (opcode >= (1 << preShift)) {
2264 code.emitop0(opcode >> preShift);
2265 opcode = opcode & 0xFF;
2266 }
2267 }
2268 if (opcode >= ifeq && opcode <= if_acmpne ||
2269 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2270 return items.makeCondItem(opcode);
2271 } else {
2272 code.emitop0(opcode);
2273 return items.makeStackItem(optype.restype);
2274 }
2275 }
2276
2277 public void visitTypeCast(JCTypeCast tree) {
2278 result = genExpr(tree.expr, tree.clazz.type).load();
2279 setTypeAnnotationPositions(tree.pos);
2280 // Additional code is only needed if we cast to a reference type
2281 // which is not statically a supertype of the expression's type.
2282 // For basic types, the coerce(...) in genExpr(...) will do
2283 // the conversion.
2284 if (!tree.clazz.type.isPrimitive() &&
2285 !types.isSameType(tree.expr.type, tree.clazz.type) &&
2286 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2287 code.emitop2(checkcast, checkDimension(tree.pos(), tree.clazz.type), PoolWriter::putClass);
2288 }
2289 }
2290
2291 public void visitWildcard(JCWildcard tree) {
2292 throw new AssertionError(this.getClass().getName());
2293 }
2294
2295 public void visitTypeTest(JCInstanceOf tree) {
2296 genExpr(tree.expr, tree.expr.type).load();
2297 setTypeAnnotationPositions(tree.pos);
2298 code.emitop2(instanceof_, makeRef(tree.pos(), tree.pattern.type));
2299 result = items.makeStackItem(syms.booleanType);
2300 }
2301
2302 public void visitIndexed(JCArrayAccess tree) {
2303 genExpr(tree.indexed, tree.indexed.type).load();
2304 genExpr(tree.index, syms.intType).load();
2305 result = items.makeIndexedItem(tree.type);
2306 }
2307
2308 public void visitIdent(JCIdent tree) {
2309 Symbol sym = tree.sym;
2310 if (tree.name == names._this || tree.name == names._super) {
2311 Item res = tree.name == names._this
2312 ? items.makeThisItem()
2313 : items.makeSuperItem();
2314 if (sym.kind == MTH) {
2315 // Generate code to address the constructor.
2316 res.load();
2317 res = items.makeMemberItem(sym, true);
2318 }
2319 result = res;
2320 } else if (isInvokeDynamic(sym) || isConstantDynamic(sym)) {
2321 if (isConstantDynamic(sym)) {
2322 setTypeAnnotationPositions(tree.pos);
2323 }
2324 result = items.makeDynamicItem(sym);
2325 } else if (sym.kind == VAR && (sym.owner.kind == MTH || sym.owner.kind == VAR)) {
2326 result = items.makeLocalItem((VarSymbol)sym);
2327 } else if ((sym.flags() & STATIC) != 0) {
2328 if (!isAccessSuper(env.enclMethod))
2329 sym = binaryQualifier(sym, env.enclClass.type);
2330 result = items.makeStaticItem(sym);
2331 } else {
2332 items.makeThisItem().load();
2333 sym = binaryQualifier(sym, env.enclClass.type);
2334 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym));
2335 }
2336 }
2337
2338 //where
2339 private boolean nonVirtualForPrivateAccess(Symbol sym) {
2340 boolean useVirtual = target.hasVirtualPrivateInvoke() &&
2341 !disableVirtualizedPrivateInvoke;
2342 return !useVirtual && ((sym.flags() & PRIVATE) != 0);
2343 }
2344
2345 public void visitSelect(JCFieldAccess tree) {
2346 Symbol sym = tree.sym;
2347
2348 if (tree.name == names._class) {
2349 code.emitLdc((LoadableConstant)checkDimension(tree.pos(), tree.selected.type));
2350 result = items.makeStackItem(pt);
2351 return;
2352 }
2353
2354 Symbol ssym = TreeInfo.symbol(tree.selected);
2355
2356 // Are we selecting via super?
2357 boolean selectSuper =
2358 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2359
2360 // Are we accessing a member of the superclass in an access method
2361 // resulting from a qualified super?
2362 boolean accessSuper = isAccessSuper(env.enclMethod);
2363
2364 Item base = (selectSuper)
2365 ? items.makeSuperItem()
2366 : genExpr(tree.selected, tree.selected.type);
2367
2368 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2369 // We are seeing a variable that is constant but its selecting
2370 // expression is not.
2371 if ((sym.flags() & STATIC) != 0) {
2372 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2373 base = base.load();
2374 base.drop();
2375 } else {
2376 base.load();
2377 genNullCheck(tree.selected);
2378 }
2379 result = items.
2380 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2381 } else {
2382 if (isInvokeDynamic(sym)) {
2383 result = items.makeDynamicItem(sym);
2384 return;
2385 } else {
2386 sym = binaryQualifier(sym, tree.selected.type);
2387 }
2388 if ((sym.flags() & STATIC) != 0) {
2389 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2390 base = base.load();
2391 base.drop();
2392 result = items.makeStaticItem(sym);
2393 } else {
2394 base.load();
2395 if (sym == syms.lengthVar) {
2396 code.emitop0(arraylength);
2397 result = items.makeStackItem(syms.intType);
2398 } else {
2399 result = items.
2400 makeMemberItem(sym,
2401 nonVirtualForPrivateAccess(sym) ||
2402 selectSuper || accessSuper);
2403 }
2404 }
2405 }
2406 }
2407
2408 public boolean isInvokeDynamic(Symbol sym) {
2409 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
2410 }
2411
2412 public void visitLiteral(JCLiteral tree) {
2413 if (tree.type.hasTag(BOT)) {
2414 code.emitop0(aconst_null);
2415 result = items.makeStackItem(tree.type);
2416 }
2417 else
2418 result = items.makeImmediateItem(tree.type, tree.value);
2419 }
2420
2421 public void visitLetExpr(LetExpr tree) {
2422 code.resolvePending();
2423
2424 int limit = code.nextreg;
2425 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
2426 try {
2427 genStats(tree.defs, env);
2428 } finally {
2429 code.setLetExprStackPos(prevLetExprStart);
2430 }
2431 result = genExpr(tree.expr, tree.expr.type).load();
2432 code.endScopes(limit);
2433 }
2434
2435 private void generateReferencesToPrunedTree(ClassSymbol classSymbol) {
2436 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
2437 if (prunedInfo != null) {
2438 for (JCTree prunedTree: prunedInfo) {
2439 prunedTree.accept(classReferenceVisitor);
2440 }
2441 }
2442 }
2443
2444 /* ************************************************************************
2445 * main method
2446 *************************************************************************/
2447
2448 /** Generate code for a class definition.
2449 * @param env The attribution environment that belongs to the
2450 * outermost class containing this class definition.
2451 * We need this for resolving some additional symbols.
2452 * @param cdef The tree representing the class definition.
2453 * @return True if code is generated with no errors.
2454 */
2455 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2456 try {
2457 attrEnv = env;
2458 ClassSymbol c = cdef.sym;
2459 this.toplevel = env.toplevel;
2460 this.endPosTable = toplevel.endPositions;
2461 /* method normalizeDefs() can add references to external classes into the constant pool
2462 */
2463 cdef.defs = normalizeDefs(cdef.defs, c);
2464 generateReferencesToPrunedTree(c);
2465 Env<GenContext> localEnv = new Env<>(cdef, new GenContext());
2466 localEnv.toplevel = env.toplevel;
2467 localEnv.enclClass = cdef;
2468
2469 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2470 genDef(l.head, localEnv);
2471 }
2472 if (poolWriter.size() > PoolWriter.MAX_ENTRIES) {
2473 log.error(cdef.pos(), Errors.LimitPool);
2474 nerrs++;
2475 }
2476 if (nerrs != 0) {
2477 // if errors, discard code
2478 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2479 if (l.head.hasTag(METHODDEF))
2480 ((JCMethodDecl) l.head).sym.code = null;
2481 }
2482 }
2483 cdef.defs = List.nil(); // discard trees
2484 return nerrs == 0;
2485 } finally {
2486 // note: this method does NOT support recursion.
2487 attrEnv = null;
2488 this.env = null;
2489 toplevel = null;
2490 endPosTable = null;
2491 nerrs = 0;
2492 qualifiedSymbolCache.clear();
2493 }
2494 }
2495
2496 /* ************************************************************************
2497 * Auxiliary classes
2498 *************************************************************************/
2499
2500 /** An abstract class for finalizer generation.
2501 */
2502 abstract class GenFinalizer {
2503 /** Generate code to clean up when unwinding. */
2504 abstract void gen();
2505
2506 /** Generate code to clean up at last. */
2507 abstract void genLast();
2508
2509 /** Does this finalizer have some nontrivial cleanup to perform? */
2510 boolean hasFinalizer() { return true; }
2511
2512 /** Should be invoked after the try's body has been visited. */
2513 void afterBody() {}
2514 }
2515
2516 /** code generation contexts,
2517 * to be used as type parameter for environments.
2518 */
2519 static class GenContext {
2520
2521 /** A chain for all unresolved jumps that exit the current environment.
2522 */
2523 Chain exit = null;
2524
2525 /** A chain for all unresolved jumps that continue in the
2526 * current environment.
2527 */
2528 Chain cont = null;
2529
2530 /** A closure that generates the finalizer of the current environment.
2531 * Only set for Synchronized and Try contexts.
2532 */
2533 GenFinalizer finalize = null;
2534
2535 /** Is this a switch statement? If so, allocate registers
2536 * even when the variable declaration is unreachable.
2537 */
2538 boolean isSwitch = false;
2539
2540 /** A list buffer containing all gaps in the finalizer range,
2541 * where a catch all exception should not apply.
2542 */
2543 ListBuffer<Integer> gaps = null;
2544
2545 /** Add given chain to exit chain.
2546 */
2547 void addExit(Chain c) {
2548 exit = Code.mergeChains(c, exit);
2549 }
2550
2551 /** Add given chain to cont chain.
2552 */
2553 void addCont(Chain c) {
2554 cont = Code.mergeChains(c, cont);
2555 }
2556 }
2557
2558 }