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 if (tree.patternMatchingCatch != null) {
1078 Set<JCMethodInvocation> prevInvocationsWithPatternMatchingCatch = invocationsWithPatternMatchingCatch;
1079 ListBuffer<int[]> prevRanges = patternMatchingInvocationRanges;
1080 State startState = code.state.dup();
1081 try {
1082 invocationsWithPatternMatchingCatch = tree.patternMatchingCatch.calls2Handle();
1083 patternMatchingInvocationRanges = new ListBuffer<>();
1084 doVisitBlock(tree);
1085 } finally {
1086 Chain skipCatch = code.branch(goto_);
1087 JCCatch handler = tree.patternMatchingCatch.handler();
1088 code.entryPoint(startState, handler.param.sym.type);
1089 genPatternMatchingCatch(handler, env, patternMatchingInvocationRanges.toList());
1090 code.resolve(skipCatch);
1091 invocationsWithPatternMatchingCatch = prevInvocationsWithPatternMatchingCatch;
1092 patternMatchingInvocationRanges = prevRanges;
1093 }
1094 } else {
1095 doVisitBlock(tree);
1096 }
1097 }
1098
1099 private void doVisitBlock(JCBlock tree) {
1100 int limit = code.nextreg;
1101 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1102 genStats(tree.stats, localEnv);
1103 // End the scope of all block-local variables in variable info.
1104 if (!env.tree.hasTag(METHODDEF)) {
1105 code.statBegin(tree.endpos);
1106 code.endScopes(limit);
1107 code.pendingStatPos = Position.NOPOS;
1108 }
1109 }
1110
1111 public void visitDoLoop(JCDoWhileLoop tree) {
1112 genLoop(tree, tree.body, tree.cond, List.nil(), false);
1113 }
1114
1115 public void visitWhileLoop(JCWhileLoop tree) {
1116 genLoop(tree, tree.body, tree.cond, List.nil(), true);
1117 }
1118
1119 public void visitForLoop(JCForLoop tree) {
1120 int limit = code.nextreg;
1121 genStats(tree.init, env);
1122 genLoop(tree, tree.body, tree.cond, tree.step, true);
1123 code.endScopes(limit);
1124 }
1125 //where
1126 /** Generate code for a loop.
1127 * @param loop The tree representing the loop.
1128 * @param body The loop's body.
1129 * @param cond The loop's controlling condition.
1130 * @param step "Step" statements to be inserted at end of
1131 * each iteration.
1132 * @param testFirst True if the loop test belongs before the body.
1133 */
1134 private void genLoop(JCStatement loop,
1135 JCStatement body,
1136 JCExpression cond,
1137 List<JCExpressionStatement> step,
1138 boolean testFirst) {
1139 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1140 int startpc = code.entryPoint();
1141 if (testFirst) { //while or for loop
1142 CondItem c;
1143 if (cond != null) {
1144 code.statBegin(cond.pos);
1145 Assert.check(code.isStatementStart());
1146 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1147 } else {
1148 c = items.makeCondItem(goto_);
1149 }
1150 Chain loopDone = c.jumpFalse();
1151 code.resolve(c.trueJumps);
1152 Assert.check(code.isStatementStart());
1153 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1154 code.resolve(loopEnv.info.cont);
1155 genStats(step, loopEnv);
1156 code.resolve(code.branch(goto_), startpc);
1157 code.resolve(loopDone);
1158 } else {
1159 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1160 code.resolve(loopEnv.info.cont);
1161 genStats(step, loopEnv);
1162 if (code.isAlive()) {
1163 CondItem c;
1164 if (cond != null) {
1165 code.statBegin(cond.pos);
1166 Assert.check(code.isStatementStart());
1167 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1168 } else {
1169 c = items.makeCondItem(goto_);
1170 }
1171 code.resolve(c.jumpTrue(), startpc);
1172 Assert.check(code.isStatementStart());
1173 code.resolve(c.falseJumps);
1174 }
1175 }
1176 Chain exit = loopEnv.info.exit;
1177 if (exit != null) {
1178 code.resolve(exit);
1179 exit.state.defined.excludeFrom(code.nextreg);
1180 }
1181 }
1182
1183 public void visitForeachLoop(JCEnhancedForLoop tree) {
1184 throw new AssertionError(); // should have been removed by Lower.
1185 }
1186
1187 public void visitLabelled(JCLabeledStatement tree) {
1188 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1189 genStat(tree.body, localEnv, CRT_STATEMENT);
1190 Chain exit = localEnv.info.exit;
1191 if (exit != null) {
1192 code.resolve(exit);
1193 exit.state.defined.excludeFrom(code.nextreg);
1194 }
1195 }
1196
1197 public void visitSwitch(JCSwitch tree) {
1198 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1199 }
1200
1201 @Override
1202 public void visitSwitchExpression(JCSwitchExpression tree) {
1203 code.resolvePending();
1204 boolean prevInCondSwitchExpression = inCondSwitchExpression;
1205 try {
1206 inCondSwitchExpression = false;
1207 doHandleSwitchExpression(tree);
1208 } finally {
1209 inCondSwitchExpression = prevInCondSwitchExpression;
1210 }
1211 result = items.makeStackItem(pt);
1212 }
1213
1214 private void doHandleSwitchExpression(JCSwitchExpression tree) {
1215 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
1216 LocalItem prevSwitchResult = switchResult;
1217 int limit = code.nextreg;
1218 try {
1219 stackBeforeSwitchExpression = List.nil();
1220 switchResult = null;
1221 if (hasTry(tree)) {
1222 //if the switch expression contains try-catch, the catch handlers need to have
1223 //an empty stack. So stash whole stack to local variables, and restore it before
1224 //breaks:
1225 while (code.state.stacksize > 0) {
1226 Type type = code.state.peek();
1227 Name varName = names.fromString(target.syntheticNameChar() +
1228 "stack" +
1229 target.syntheticNameChar() +
1230 tree.pos +
1231 target.syntheticNameChar() +
1232 code.state.stacksize);
1233 VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type,
1234 this.env.enclMethod.sym);
1235 LocalItem item = items.new LocalItem(type, code.newLocal(var));
1236 stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item);
1237 item.store();
1238 }
1239 switchResult = makeTemp(tree.type);
1240 }
1241 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
1242 try {
1243 handleSwitch(tree, tree.selector, tree.cases, tree.patternSwitch);
1244 } finally {
1245 code.setLetExprStackPos(prevLetExprStart);
1246 }
1247 } finally {
1248 stackBeforeSwitchExpression = prevStackBeforeSwitchExpression;
1249 switchResult = prevSwitchResult;
1250 code.endScopes(limit);
1251 }
1252 }
1253 //where:
1254 private boolean hasTry(JCSwitchExpression tree) {
1255 class HasTryScanner extends TreeScanner {
1256 private boolean hasTry;
1257
1258 @Override
1259 public void visitTry(JCTry tree) {
1260 hasTry = true;
1261 }
1262
1263 @Override
1264 public void visitSynchronized(JCSynchronized tree) {
1265 hasTry = true;
1266 }
1267
1268 @Override
1269 public void visitClassDef(JCClassDecl tree) {
1270 }
1271
1272 @Override
1273 public void visitLambda(JCLambda tree) {
1274 }
1275 };
1276
1277 HasTryScanner hasTryScanner = new HasTryScanner();
1278
1279 hasTryScanner.scan(tree);
1280 return hasTryScanner.hasTry;
1281 }
1282
1283 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases,
1284 boolean patternSwitch) {
1285 int limit = code.nextreg;
1286 Assert.check(!selector.type.hasTag(CLASS));
1287 int switchStart = patternSwitch ? code.entryPoint() : -1;
1288 int startpcCrt = genCrt ? code.curCP() : 0;
1289 Assert.check(code.isStatementStart());
1290 Item sel = genExpr(selector, syms.intType);
1291 if (cases.isEmpty()) {
1292 // We are seeing: switch <sel> {}
1293 sel.load().drop();
1294 if (genCrt)
1295 code.crt.put(TreeInfo.skipParens(selector),
1296 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1297 } else {
1298 // We are seeing a nonempty switch.
1299 sel.load();
1300 if (genCrt)
1301 code.crt.put(TreeInfo.skipParens(selector),
1302 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1303 Env<GenContext> switchEnv = env.dup(swtch, new GenContext());
1304 switchEnv.info.isSwitch = true;
1305
1306 // Compute number of labels and minimum and maximum label values.
1307 // For each case, store its label in an array.
1308 int lo = Integer.MAX_VALUE; // minimum label.
1309 int hi = Integer.MIN_VALUE; // maximum label.
1310 int nlabels = 0; // number of labels.
1311
1312 int[] labels = new int[cases.length()]; // the label array.
1313 int defaultIndex = -1; // the index of the default clause.
1314
1315 List<JCCase> l = cases;
1316 for (int i = 0; i < labels.length; i++) {
1317 if (l.head.labels.head instanceof JCConstantCaseLabel constLabel) {
1318 Assert.check(l.head.labels.size() == 1);
1319 int val = ((Number) constLabel.expr.type.constValue()).intValue();
1320 labels[i] = val;
1321 if (val < lo) lo = val;
1322 if (hi < val) hi = val;
1323 nlabels++;
1324 } else {
1325 Assert.check(defaultIndex == -1);
1326 defaultIndex = i;
1327 }
1328 l = l.tail;
1329 }
1330
1331 // Determine whether to issue a tableswitch or a lookupswitch
1332 // instruction.
1333 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1334 long table_time_cost = 3; // comparisons
1335 long lookup_space_cost = 3 + 2 * (long) nlabels;
1336 long lookup_time_cost = nlabels;
1337 int opcode =
1338 nlabels > 0 &&
1339 table_space_cost + 3 * table_time_cost <=
1340 lookup_space_cost + 3 * lookup_time_cost
1341 ?
1342 tableswitch : lookupswitch;
1343
1344 int startpc = code.curCP(); // the position of the selector operation
1345 code.emitop0(opcode);
1346 code.align(4);
1347 int tableBase = code.curCP(); // the start of the jump table
1348 int[] offsets = null; // a table of offsets for a lookupswitch
1349 code.emit4(-1); // leave space for default offset
1350 if (opcode == tableswitch) {
1351 code.emit4(lo); // minimum label
1352 code.emit4(hi); // maximum label
1353 for (long i = lo; i <= hi; i++) { // leave space for jump table
1354 code.emit4(-1);
1355 }
1356 } else {
1357 code.emit4(nlabels); // number of labels
1358 for (int i = 0; i < nlabels; i++) {
1359 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1360 }
1361 offsets = new int[labels.length];
1362 }
1363 Code.State stateSwitch = code.state.dup();
1364 code.markDead();
1365
1366 // For each case do:
1367 l = cases;
1368 for (int i = 0; i < labels.length; i++) {
1369 JCCase c = l.head;
1370 l = l.tail;
1371
1372 int pc = code.entryPoint(stateSwitch);
1373 // Insert offset directly into code or else into the
1374 // offsets table.
1375 if (i != defaultIndex) {
1376 if (opcode == tableswitch) {
1377 code.put4(
1378 tableBase + 4 * (labels[i] - lo + 3),
1379 pc - startpc);
1380 } else {
1381 offsets[i] = pc - startpc;
1382 }
1383 } else {
1384 code.put4(tableBase, pc - startpc);
1385 }
1386
1387 // Generate code for the statements in this case.
1388 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1389 }
1390
1391 if (switchEnv.info.cont != null) {
1392 Assert.check(patternSwitch);
1393 code.resolve(switchEnv.info.cont, switchStart);
1394 }
1395
1396 // Resolve all breaks.
1397 Chain exit = switchEnv.info.exit;
1398 if (exit != null) {
1399 code.resolve(exit);
1400 exit.state.defined.excludeFrom(limit);
1401 }
1402
1403 // If we have not set the default offset, we do so now.
1404 if (code.get4(tableBase) == -1) {
1405 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1406 }
1407
1408 if (opcode == tableswitch) {
1409 // Let any unfilled slots point to the default case.
1410 int defaultOffset = code.get4(tableBase);
1411 for (long i = lo; i <= hi; i++) {
1412 int t = (int)(tableBase + 4 * (i - lo + 3));
1413 if (code.get4(t) == -1)
1414 code.put4(t, defaultOffset);
1415 }
1416 } else {
1417 // Sort non-default offsets and copy into lookup table.
1418 if (defaultIndex >= 0)
1419 for (int i = defaultIndex; i < labels.length - 1; i++) {
1420 labels[i] = labels[i+1];
1421 offsets[i] = offsets[i+1];
1422 }
1423 if (nlabels > 0)
1424 qsort2(labels, offsets, 0, nlabels - 1);
1425 for (int i = 0; i < nlabels; i++) {
1426 int caseidx = tableBase + 8 * (i + 1);
1427 code.put4(caseidx, labels[i]);
1428 code.put4(caseidx + 4, offsets[i]);
1429 }
1430 }
1431 }
1432 code.endScopes(limit);
1433 }
1434 //where
1435 /** Sort (int) arrays of keys and values
1436 */
1437 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1438 int i = lo;
1439 int j = hi;
1440 int pivot = keys[(i+j)/2];
1441 do {
1442 while (keys[i] < pivot) i++;
1443 while (pivot < keys[j]) j--;
1444 if (i <= j) {
1445 int temp1 = keys[i];
1446 keys[i] = keys[j];
1447 keys[j] = temp1;
1448 int temp2 = values[i];
1449 values[i] = values[j];
1450 values[j] = temp2;
1451 i++;
1452 j--;
1453 }
1454 } while (i <= j);
1455 if (lo < j) qsort2(keys, values, lo, j);
1456 if (i < hi) qsort2(keys, values, i, hi);
1457 }
1458
1459 public void visitSynchronized(JCSynchronized tree) {
1460 int limit = code.nextreg;
1461 // Generate code to evaluate lock and save in temporary variable.
1462 final LocalItem lockVar = makeTemp(syms.objectType);
1463 Assert.check(code.isStatementStart());
1464 genExpr(tree.lock, tree.lock.type).load().duplicate();
1465 lockVar.store();
1466
1467 // Generate code to enter monitor.
1468 code.emitop0(monitorenter);
1469 code.state.lock(lockVar.reg);
1470
1471 // Generate code for a try statement with given body, no catch clauses
1472 // in a new environment with the "exit-monitor" operation as finalizer.
1473 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1474 syncEnv.info.finalize = new GenFinalizer() {
1475 void gen() {
1476 genLast();
1477 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1478 syncEnv.info.gaps.append(code.curCP());
1479 }
1480 void genLast() {
1481 if (code.isAlive()) {
1482 lockVar.load();
1483 code.emitop0(monitorexit);
1484 code.state.unlock(lockVar.reg);
1485 }
1486 }
1487 };
1488 syncEnv.info.gaps = new ListBuffer<>();
1489 genTry(tree.body, List.nil(), syncEnv);
1490 code.endScopes(limit);
1491 }
1492
1493 public void visitTry(final JCTry tree) {
1494 // Generate code for a try statement with given body and catch clauses,
1495 // in a new environment which calls the finally block if there is one.
1496 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1497 final Env<GenContext> oldEnv = env;
1498 tryEnv.info.finalize = new GenFinalizer() {
1499 void gen() {
1500 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1501 tryEnv.info.gaps.append(code.curCP());
1502 genLast();
1503 }
1504 void genLast() {
1505 if (tree.finalizer != null)
1506 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1507 }
1508 boolean hasFinalizer() {
1509 return tree.finalizer != null;
1510 }
1511
1512 @Override
1513 void afterBody() {
1514 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1515 //for body-only finally, remove the GenFinalizer after try body
1516 //so that the finally is not generated to catch bodies:
1517 tryEnv.info.finalize = null;
1518 }
1519 }
1520
1521 };
1522 tryEnv.info.gaps = new ListBuffer<>();
1523 genTry(tree.body, tree.catchers, tryEnv);
1524 }
1525 //where
1526 /** Generate code for a try or synchronized statement
1527 * @param body The body of the try or synchronized statement.
1528 * @param catchers The list of catch clauses.
1529 * @param env The current environment of the body.
1530 */
1531 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1532 int limit = code.nextreg;
1533 int startpc = code.curCP();
1534 Code.State stateTry = code.state.dup();
1535 genStat(body, env, CRT_BLOCK);
1536 int endpc = code.curCP();
1537 List<Integer> gaps = env.info.gaps.toList();
1538 code.statBegin(TreeInfo.endPos(body));
1539 genFinalizer(env);
1540 code.statBegin(TreeInfo.endPos(env.tree));
1541 Chain exitChain;
1542 boolean actualTry = env.tree.hasTag(TRY);
1543 if (startpc == endpc && actualTry) {
1544 exitChain = code.branch(dontgoto);
1545 } else {
1546 exitChain = code.branch(goto_);
1547 }
1548 endFinalizerGap(env);
1549 env.info.finalize.afterBody();
1550 boolean hasFinalizer =
1551 env.info.finalize != null &&
1552 env.info.finalize.hasFinalizer();
1553 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1554 // start off with exception on stack
1555 code.entryPoint(stateTry, l.head.param.sym.type);
1556 genCatch(l.head, env, startpc, endpc, gaps);
1557 genFinalizer(env);
1558 if (hasFinalizer || l.tail.nonEmpty()) {
1559 code.statBegin(TreeInfo.endPos(env.tree));
1560 exitChain = Code.mergeChains(exitChain,
1561 code.branch(goto_));
1562 }
1563 endFinalizerGap(env);
1564 }
1565 if (hasFinalizer && (startpc != endpc || !actualTry)) {
1566 // Create a new register segment to avoid allocating
1567 // the same variables in finalizers and other statements.
1568 code.newRegSegment();
1569
1570 // Add a catch-all clause.
1571
1572 // start off with exception on stack
1573 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1574
1575 // Register all exception ranges for catch all clause.
1576 // The range of the catch all clause is from the beginning
1577 // of the try or synchronized block until the present
1578 // code pointer excluding all gaps in the current
1579 // environment's GenContext.
1580 int startseg = startpc;
1581 while (env.info.gaps.nonEmpty()) {
1582 int endseg = env.info.gaps.next().intValue();
1583 registerCatch(body.pos(), startseg, endseg,
1584 catchallpc, 0);
1585 startseg = env.info.gaps.next().intValue();
1586 }
1587 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1588 code.markStatBegin();
1589
1590 Item excVar = makeTemp(syms.throwableType);
1591 excVar.store();
1592 genFinalizer(env);
1593 code.resolvePending();
1594 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1595 code.markStatBegin();
1596
1597 excVar.load();
1598 registerCatch(body.pos(), startseg,
1599 env.info.gaps.next().intValue(),
1600 catchallpc, 0);
1601 code.emitop0(athrow);
1602 code.markDead();
1603
1604 // If there are jsr's to this finalizer, ...
1605 if (env.info.cont != null) {
1606 // Resolve all jsr's.
1607 code.resolve(env.info.cont);
1608
1609 // Mark statement line number
1610 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1611 code.markStatBegin();
1612
1613 // Save return address.
1614 LocalItem retVar = makeTemp(syms.throwableType);
1615 retVar.store();
1616
1617 // Generate finalizer code.
1618 env.info.finalize.genLast();
1619
1620 // Return.
1621 code.emitop1w(ret, retVar.reg);
1622 code.markDead();
1623 }
1624 }
1625 // Resolve all breaks.
1626 code.resolve(exitChain);
1627
1628 code.endScopes(limit);
1629 }
1630
1631 /** Generate code for a catch clause.
1632 * @param tree The catch clause.
1633 * @param env The environment current in the enclosing try.
1634 * @param startpc Start pc of try-block.
1635 * @param endpc End pc of try-block.
1636 */
1637 void genCatch(JCCatch tree,
1638 Env<GenContext> env,
1639 int startpc, int endpc,
1640 List<Integer> gaps) {
1641 if (startpc != endpc) {
1642 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs
1643 = catchTypesWithAnnotations(tree);
1644 while (gaps.nonEmpty()) {
1645 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1646 JCExpression subCatch = subCatch1.snd;
1647 int catchType = makeRef(tree.pos(), subCatch.type);
1648 int end = gaps.head.intValue();
1649 registerCatch(tree.pos(),
1650 startpc, end, code.curCP(),
1651 catchType);
1652 for (Attribute.TypeCompound tc : subCatch1.fst) {
1653 tc.position.setCatchInfo(catchType, startpc);
1654 }
1655 }
1656 gaps = gaps.tail;
1657 startpc = gaps.head.intValue();
1658 gaps = gaps.tail;
1659 }
1660 if (startpc < endpc) {
1661 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1662 JCExpression subCatch = subCatch1.snd;
1663 int catchType = makeRef(tree.pos(), subCatch.type);
1664 registerCatch(tree.pos(),
1665 startpc, endpc, code.curCP(),
1666 catchType);
1667 for (Attribute.TypeCompound tc : subCatch1.fst) {
1668 tc.position.setCatchInfo(catchType, startpc);
1669 }
1670 }
1671 }
1672 genCatchBlock(tree, env);
1673 }
1674 }
1675 void genPatternMatchingCatch(JCCatch tree,
1676 Env<GenContext> env,
1677 List<int[]> ranges) {
1678 for (int[] range : ranges) {
1679 JCExpression subCatch = tree.param.vartype;
1680 int catchType = makeRef(tree.pos(), subCatch.type);
1681 registerCatch(tree.pos(),
1682 range[0], range[1], code.curCP(),
1683 catchType);
1684 }
1685 genCatchBlock(tree, env);
1686 }
1687 void genCatchBlock(JCCatch tree, Env<GenContext> env) {
1688 VarSymbol exparam = tree.param.sym;
1689 code.statBegin(tree.pos);
1690 code.markStatBegin();
1691 int limit = code.nextreg;
1692 code.newLocal(exparam);
1693 items.makeLocalItem(exparam).store();
1694 code.statBegin(TreeInfo.firstStatPos(tree.body));
1695 genStat(tree.body, env, CRT_BLOCK);
1696 code.endScopes(limit);
1697 code.statBegin(TreeInfo.endPos(tree.body));
1698 }
1699 // where
1700 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) {
1701 return TreeInfo.isMultiCatch(tree) ?
1702 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) :
1703 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype));
1704 }
1705 // where
1706 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) {
1707 List<JCExpression> alts = tree.alternatives;
1708 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head));
1709 alts = alts.tail;
1710
1711 while(alts != null && alts.head != null) {
1712 JCExpression alt = alts.head;
1713 if (alt instanceof JCAnnotatedType annotatedType) {
1714 res = res.prepend(new Pair<>(annotate.fromAnnotations(annotatedType.annotations), alt));
1715 } else {
1716 res = res.prepend(new Pair<>(List.nil(), alt));
1717 }
1718 alts = alts.tail;
1719 }
1720 return res.reverse();
1721 }
1722
1723 /** Register a catch clause in the "Exceptions" code-attribute.
1724 */
1725 void registerCatch(DiagnosticPosition pos,
1726 int startpc, int endpc,
1727 int handler_pc, int catch_type) {
1728 char startpc1 = (char)startpc;
1729 char endpc1 = (char)endpc;
1730 char handler_pc1 = (char)handler_pc;
1731 if (startpc1 == startpc &&
1732 endpc1 == endpc &&
1733 handler_pc1 == handler_pc) {
1734 code.addCatch(startpc1, endpc1, handler_pc1,
1735 (char)catch_type);
1736 } else {
1737 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1738 nerrs++;
1739 }
1740 }
1741
1742 public void visitIf(JCIf tree) {
1743 int limit = code.nextreg;
1744 Chain thenExit = null;
1745 Assert.check(code.isStatementStart());
1746 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1747 CRT_FLOW_CONTROLLER);
1748 Chain elseChain = c.jumpFalse();
1749 Assert.check(code.isStatementStart());
1750 if (!c.isFalse()) {
1751 code.resolve(c.trueJumps);
1752 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1753 thenExit = code.branch(goto_);
1754 }
1755 if (elseChain != null) {
1756 code.resolve(elseChain);
1757 if (tree.elsepart != null) {
1758 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1759 }
1760 }
1761 code.resolve(thenExit);
1762 code.endScopes(limit);
1763 Assert.check(code.isStatementStart());
1764 }
1765
1766 public void visitExec(JCExpressionStatement tree) {
1767 // Optimize x++ to ++x and x-- to --x.
1768 JCExpression e = tree.expr;
1769 switch (e.getTag()) {
1770 case POSTINC:
1771 ((JCUnary) e).setTag(PREINC);
1772 break;
1773 case POSTDEC:
1774 ((JCUnary) e).setTag(PREDEC);
1775 break;
1776 }
1777 Assert.check(code.isStatementStart());
1778 genExpr(tree.expr, tree.expr.type).drop();
1779 Assert.check(code.isStatementStart());
1780 }
1781
1782 public void visitBreak(JCBreak tree) {
1783 Assert.check(code.isStatementStart());
1784 final Env<GenContext> targetEnv = unwindBreak(tree.target);
1785 targetEnv.info.addExit(code.branch(goto_));
1786 endFinalizerGaps(env, targetEnv);
1787 }
1788
1789 public void visitYield(JCYield tree) {
1790 Assert.check(code.isStatementStart());
1791 final Env<GenContext> targetEnv;
1792 if (inCondSwitchExpression) {
1793 CondItem value = genCond(tree.value, CRT_FLOW_TARGET);
1794 Chain falseJumps = value.jumpFalse();
1795
1796 code.resolve(value.trueJumps);
1797 Env<GenContext> localEnv = unwindBreak(tree.target);
1798 reloadStackBeforeSwitchExpr();
1799 Chain trueJumps = code.branch(goto_);
1800
1801 endFinalizerGaps(env, localEnv);
1802
1803 code.resolve(falseJumps);
1804 targetEnv = unwindBreak(tree.target);
1805 reloadStackBeforeSwitchExpr();
1806 falseJumps = code.branch(goto_);
1807
1808 if (switchExpressionTrueChain == null) {
1809 switchExpressionTrueChain = trueJumps;
1810 } else {
1811 switchExpressionTrueChain =
1812 Code.mergeChains(switchExpressionTrueChain, trueJumps);
1813 }
1814 if (switchExpressionFalseChain == null) {
1815 switchExpressionFalseChain = falseJumps;
1816 } else {
1817 switchExpressionFalseChain =
1818 Code.mergeChains(switchExpressionFalseChain, falseJumps);
1819 }
1820 } else {
1821 genExpr(tree.value, pt).load();
1822 if (switchResult != null)
1823 switchResult.store();
1824
1825 targetEnv = unwindBreak(tree.target);
1826
1827 if (code.isAlive()) {
1828 reloadStackBeforeSwitchExpr();
1829 if (switchResult != null)
1830 switchResult.load();
1831
1832 code.state.forceStackTop(tree.target.type);
1833 targetEnv.info.addExit(code.branch(goto_));
1834 code.markDead();
1835 }
1836 }
1837 endFinalizerGaps(env, targetEnv);
1838 }
1839 //where:
1840 /** As side-effect, might mark code as dead disabling any further emission.
1841 */
1842 private Env<GenContext> unwindBreak(JCTree target) {
1843 int tmpPos = code.pendingStatPos;
1844 Env<GenContext> targetEnv = unwind(target, env);
1845 code.pendingStatPos = tmpPos;
1846 return targetEnv;
1847 }
1848
1849 private void reloadStackBeforeSwitchExpr() {
1850 for (LocalItem li : stackBeforeSwitchExpression)
1851 li.load();
1852 }
1853
1854 public void visitContinue(JCContinue tree) {
1855 int tmpPos = code.pendingStatPos;
1856 Env<GenContext> targetEnv = unwind(tree.target, env);
1857 code.pendingStatPos = tmpPos;
1858 Assert.check(code.isStatementStart());
1859 targetEnv.info.addCont(code.branch(goto_));
1860 endFinalizerGaps(env, targetEnv);
1861 }
1862
1863 public void visitReturn(JCReturn tree) {
1864 int limit = code.nextreg;
1865 final Env<GenContext> targetEnv;
1866
1867 /* Save and then restore the location of the return in case a finally
1868 * is expanded (with unwind()) in the middle of our bytecodes.
1869 */
1870 int tmpPos = code.pendingStatPos;
1871 if (tree.expr != null) {
1872 Assert.check(code.isStatementStart());
1873 Item r = genExpr(tree.expr, pt).load();
1874 if (hasFinally(env.enclMethod, env)) {
1875 r = makeTemp(pt);
1876 r.store();
1877 }
1878 targetEnv = unwind(env.enclMethod, env);
1879 code.pendingStatPos = tmpPos;
1880 r.load();
1881 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
1882 } else {
1883 targetEnv = unwind(env.enclMethod, env);
1884 code.pendingStatPos = tmpPos;
1885 code.emitop0(return_);
1886 }
1887 endFinalizerGaps(env, targetEnv);
1888 code.endScopes(limit);
1889 }
1890
1891 public void visitThrow(JCThrow tree) {
1892 Assert.check(code.isStatementStart());
1893 genExpr(tree.expr, tree.expr.type).load();
1894 code.emitop0(athrow);
1895 Assert.check(code.isStatementStart());
1896 }
1897
1898 /* ************************************************************************
1899 * Visitor methods for expressions
1900 *************************************************************************/
1901
1902 public void visitApply(JCMethodInvocation tree) {
1903 setTypeAnnotationPositions(tree.pos);
1904 // Generate code for method.
1905 Item m = genExpr(tree.meth, methodType);
1906 // Generate code for all arguments, where the expected types are
1907 // the parameters of the method's external type (that is, any implicit
1908 // outer instance of a super(...) call appears as first parameter).
1909 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
1910 genArgs(tree.args,
1911 msym.externalType(types).getParameterTypes());
1912 if (!msym.isDynamic()) {
1913 code.statBegin(tree.pos);
1914 }
1915 if (invocationsWithPatternMatchingCatch.contains(tree)) {
1916 int start = code.curCP();
1917 result = m.invoke();
1918 patternMatchingInvocationRanges.add(new int[] {start, code.curCP()});
1919 } else {
1920 result = m.invoke();
1921 }
1922 }
1923
1924 public void visitConditional(JCConditional tree) {
1925 Chain thenExit = null;
1926 code.statBegin(tree.cond.pos);
1927 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
1928 Chain elseChain = c.jumpFalse();
1929 if (!c.isFalse()) {
1930 code.resolve(c.trueJumps);
1931 int startpc = genCrt ? code.curCP() : 0;
1932 code.statBegin(tree.truepart.pos);
1933 genExpr(tree.truepart, pt).load();
1934 code.state.forceStackTop(tree.type);
1935 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
1936 startpc, code.curCP());
1937 thenExit = code.branch(goto_);
1938 }
1939 if (elseChain != null) {
1940 code.resolve(elseChain);
1941 int startpc = genCrt ? code.curCP() : 0;
1942 code.statBegin(tree.falsepart.pos);
1943 genExpr(tree.falsepart, pt).load();
1944 code.state.forceStackTop(tree.type);
1945 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
1946 startpc, code.curCP());
1947 }
1948 code.resolve(thenExit);
1949 result = items.makeStackItem(pt);
1950 }
1951
1952 private void setTypeAnnotationPositions(int treePos) {
1953 MethodSymbol meth = code.meth;
1954 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR
1955 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT;
1956
1957 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
1958 if (ta.hasUnknownPosition())
1959 ta.tryFixPosition();
1960
1961 if (ta.position.matchesPos(treePos))
1962 ta.position.updatePosOffset(code.cp);
1963 }
1964
1965 if (!initOrClinit)
1966 return;
1967
1968 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
1969 if (ta.hasUnknownPosition())
1970 ta.tryFixPosition();
1971
1972 if (ta.position.matchesPos(treePos))
1973 ta.position.updatePosOffset(code.cp);
1974 }
1975
1976 ClassSymbol clazz = meth.enclClass();
1977 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
1978 if (!s.getKind().isField())
1979 continue;
1980
1981 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
1982 if (ta.hasUnknownPosition())
1983 ta.tryFixPosition();
1984
1985 if (ta.position.matchesPos(treePos))
1986 ta.position.updatePosOffset(code.cp);
1987 }
1988 }
1989 }
1990
1991 public void visitNewClass(JCNewClass tree) {
1992 // Enclosing instances or anonymous classes should have been eliminated
1993 // by now.
1994 Assert.check(tree.encl == null && tree.def == null);
1995 setTypeAnnotationPositions(tree.pos);
1996
1997 code.emitop2(new_, checkDimension(tree.pos(), tree.type), PoolWriter::putClass);
1998 code.emitop0(dup);
1999
2000 // Generate code for all arguments, where the expected types are
2001 // the parameters of the constructor's external type (that is,
2002 // any implicit outer instance appears as first parameter).
2003 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
2004
2005 items.makeMemberItem(tree.constructor, true).invoke();
2006 result = items.makeStackItem(tree.type);
2007 }
2008
2009 public void visitNewArray(JCNewArray tree) {
2010 setTypeAnnotationPositions(tree.pos);
2011
2012 if (tree.elems != null) {
2013 Type elemtype = types.elemtype(tree.type);
2014 loadIntConst(tree.elems.length());
2015 Item arr = makeNewArray(tree.pos(), tree.type, 1);
2016 int i = 0;
2017 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
2018 arr.duplicate();
2019 loadIntConst(i);
2020 i++;
2021 genExpr(l.head, elemtype).load();
2022 items.makeIndexedItem(elemtype).store();
2023 }
2024 result = arr;
2025 } else {
2026 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
2027 genExpr(l.head, syms.intType).load();
2028 }
2029 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
2030 }
2031 }
2032 //where
2033 /** Generate code to create an array with given element type and number
2034 * of dimensions.
2035 */
2036 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
2037 Type elemtype = types.elemtype(type);
2038 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
2039 log.error(pos, Errors.LimitDimensions);
2040 nerrs++;
2041 }
2042 int elemcode = Code.arraycode(elemtype);
2043 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
2044 code.emitAnewarray(makeRef(pos, elemtype), type);
2045 } else if (elemcode == 1) {
2046 code.emitMultianewarray(ndims, makeRef(pos, type), type);
2047 } else {
2048 code.emitNewarray(elemcode, type);
2049 }
2050 return items.makeStackItem(type);
2051 }
2052
2053 public void visitParens(JCParens tree) {
2054 result = genExpr(tree.expr, tree.expr.type);
2055 }
2056
2057 public void visitAssign(JCAssign tree) {
2058 Item l = genExpr(tree.lhs, tree.lhs.type);
2059 genExpr(tree.rhs, tree.lhs.type).load();
2060 if (tree.rhs.type.hasTag(BOT)) {
2061 /* This is just a case of widening reference conversion that per 5.1.5 simply calls
2062 for "regarding a reference as having some other type in a manner that can be proved
2063 correct at compile time."
2064 */
2065 code.state.forceStackTop(tree.lhs.type);
2066 }
2067 result = items.makeAssignItem(l);
2068 }
2069
2070 public void visitAssignop(JCAssignOp tree) {
2071 OperatorSymbol operator = tree.operator;
2072 Item l;
2073 if (operator.opcode == string_add) {
2074 l = concat.makeConcat(tree);
2075 } else {
2076 // Generate code for first expression
2077 l = genExpr(tree.lhs, tree.lhs.type);
2078
2079 // If we have an increment of -32768 to +32767 of a local
2080 // int variable we can use an incr instruction instead of
2081 // proceeding further.
2082 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
2083 l instanceof LocalItem localItem &&
2084 tree.lhs.type.getTag().isSubRangeOf(INT) &&
2085 tree.rhs.type.getTag().isSubRangeOf(INT) &&
2086 tree.rhs.type.constValue() != null) {
2087 int ival = ((Number) tree.rhs.type.constValue()).intValue();
2088 if (tree.hasTag(MINUS_ASG)) ival = -ival;
2089 localItem.incr(ival);
2090 result = l;
2091 return;
2092 }
2093 // Otherwise, duplicate expression, load one copy
2094 // and complete binary operation.
2095 l.duplicate();
2096 l.coerce(operator.type.getParameterTypes().head).load();
2097 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
2098 }
2099 result = items.makeAssignItem(l);
2100 }
2101
2102 public void visitUnary(JCUnary tree) {
2103 OperatorSymbol operator = tree.operator;
2104 if (tree.hasTag(NOT)) {
2105 CondItem od = genCond(tree.arg, false);
2106 result = od.negate();
2107 } else {
2108 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
2109 switch (tree.getTag()) {
2110 case POS:
2111 result = od.load();
2112 break;
2113 case NEG:
2114 result = od.load();
2115 code.emitop0(operator.opcode);
2116 break;
2117 case COMPL:
2118 result = od.load();
2119 emitMinusOne(od.typecode);
2120 code.emitop0(operator.opcode);
2121 break;
2122 case PREINC: case PREDEC:
2123 od.duplicate();
2124 if (od instanceof LocalItem localItem &&
2125 (operator.opcode == iadd || operator.opcode == isub)) {
2126 localItem.incr(tree.hasTag(PREINC) ? 1 : -1);
2127 result = od;
2128 } else {
2129 od.load();
2130 code.emitop0(one(od.typecode));
2131 code.emitop0(operator.opcode);
2132 // Perform narrowing primitive conversion if byte,
2133 // char, or short. Fix for 4304655.
2134 if (od.typecode != INTcode &&
2135 Code.truncate(od.typecode) == INTcode)
2136 code.emitop0(int2byte + od.typecode - BYTEcode);
2137 result = items.makeAssignItem(od);
2138 }
2139 break;
2140 case POSTINC: case POSTDEC:
2141 od.duplicate();
2142 if (od instanceof LocalItem localItem &&
2143 (operator.opcode == iadd || operator.opcode == isub)) {
2144 Item res = od.load();
2145 localItem.incr(tree.hasTag(POSTINC) ? 1 : -1);
2146 result = res;
2147 } else {
2148 Item res = od.load();
2149 od.stash(od.typecode);
2150 code.emitop0(one(od.typecode));
2151 code.emitop0(operator.opcode);
2152 // Perform narrowing primitive conversion if byte,
2153 // char, or short. Fix for 4304655.
2154 if (od.typecode != INTcode &&
2155 Code.truncate(od.typecode) == INTcode)
2156 code.emitop0(int2byte + od.typecode - BYTEcode);
2157 od.store();
2158 result = res;
2159 }
2160 break;
2161 case NULLCHK:
2162 result = od.load();
2163 code.emitop0(dup);
2164 genNullCheck(tree);
2165 break;
2166 default:
2167 Assert.error();
2168 }
2169 }
2170 }
2171
2172 /** Generate a null check from the object value at stack top. */
2173 private void genNullCheck(JCTree tree) {
2174 code.statBegin(tree.pos);
2175 callMethod(tree.pos(), syms.objectsType, names.requireNonNull,
2176 List.of(syms.objectType), true);
2177 code.emitop0(pop);
2178 }
2179
2180 public void visitBinary(JCBinary tree) {
2181 OperatorSymbol operator = tree.operator;
2182 if (operator.opcode == string_add) {
2183 result = concat.makeConcat(tree);
2184 } else if (tree.hasTag(AND)) {
2185 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2186 if (!lcond.isFalse()) {
2187 Chain falseJumps = lcond.jumpFalse();
2188 code.resolve(lcond.trueJumps);
2189 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2190 result = items.
2191 makeCondItem(rcond.opcode,
2192 rcond.trueJumps,
2193 Code.mergeChains(falseJumps,
2194 rcond.falseJumps));
2195 } else {
2196 result = lcond;
2197 }
2198 } else if (tree.hasTag(OR)) {
2199 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2200 if (!lcond.isTrue()) {
2201 Chain trueJumps = lcond.jumpTrue();
2202 code.resolve(lcond.falseJumps);
2203 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2204 result = items.
2205 makeCondItem(rcond.opcode,
2206 Code.mergeChains(trueJumps, rcond.trueJumps),
2207 rcond.falseJumps);
2208 } else {
2209 result = lcond;
2210 }
2211 } else {
2212 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
2213 od.load();
2214 result = completeBinop(tree.lhs, tree.rhs, operator);
2215 }
2216 }
2217
2218
2219 /** Complete generating code for operation, with left operand
2220 * already on stack.
2221 * @param lhs The tree representing the left operand.
2222 * @param rhs The tree representing the right operand.
2223 * @param operator The operator symbol.
2224 */
2225 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2226 MethodType optype = (MethodType)operator.type;
2227 int opcode = operator.opcode;
2228 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2229 rhs.type.constValue() instanceof Number number &&
2230 number.intValue() == 0) {
2231 opcode = opcode + (ifeq - if_icmpeq);
2232 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2233 TreeInfo.isNull(rhs)) {
2234 opcode = opcode + (if_acmp_null - if_acmpeq);
2235 } else {
2236 // The expected type of the right operand is
2237 // the second parameter type of the operator, except for
2238 // shifts with long shiftcount, where we convert the opcode
2239 // to a short shift and the expected type to int.
2240 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2241 if (opcode >= ishll && opcode <= lushrl) {
2242 opcode = opcode + (ishl - ishll);
2243 rtype = syms.intType;
2244 }
2245 // Generate code for right operand and load.
2246 genExpr(rhs, rtype).load();
2247 // If there are two consecutive opcode instructions,
2248 // emit the first now.
2249 if (opcode >= (1 << preShift)) {
2250 code.emitop0(opcode >> preShift);
2251 opcode = opcode & 0xFF;
2252 }
2253 }
2254 if (opcode >= ifeq && opcode <= if_acmpne ||
2255 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2256 return items.makeCondItem(opcode);
2257 } else {
2258 code.emitop0(opcode);
2259 return items.makeStackItem(optype.restype);
2260 }
2261 }
2262
2263 public void visitTypeCast(JCTypeCast tree) {
2264 result = genExpr(tree.expr, tree.clazz.type).load();
2265 setTypeAnnotationPositions(tree.pos);
2266 // Additional code is only needed if we cast to a reference type
2267 // which is not statically a supertype of the expression's type.
2268 // For basic types, the coerce(...) in genExpr(...) will do
2269 // the conversion.
2270 if (!tree.clazz.type.isPrimitive() &&
2271 !types.isSameType(tree.expr.type, tree.clazz.type) &&
2272 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2273 code.emitop2(checkcast, checkDimension(tree.pos(), tree.clazz.type), PoolWriter::putClass);
2274 }
2275 }
2276
2277 public void visitWildcard(JCWildcard tree) {
2278 throw new AssertionError(this.getClass().getName());
2279 }
2280
2281 public void visitTypeTest(JCInstanceOf tree) {
2282 genExpr(tree.expr, tree.expr.type).load();
2283 setTypeAnnotationPositions(tree.pos);
2284 code.emitop2(instanceof_, makeRef(tree.pos(), tree.pattern.type));
2285 result = items.makeStackItem(syms.booleanType);
2286 }
2287
2288 public void visitIndexed(JCArrayAccess tree) {
2289 genExpr(tree.indexed, tree.indexed.type).load();
2290 genExpr(tree.index, syms.intType).load();
2291 result = items.makeIndexedItem(tree.type);
2292 }
2293
2294 public void visitIdent(JCIdent tree) {
2295 Symbol sym = tree.sym;
2296 if (tree.name == names._this || tree.name == names._super) {
2297 Item res = tree.name == names._this
2298 ? items.makeThisItem()
2299 : items.makeSuperItem();
2300 if (sym.kind == MTH) {
2301 // Generate code to address the constructor.
2302 res.load();
2303 res = items.makeMemberItem(sym, true);
2304 }
2305 result = res;
2306 } else if (isInvokeDynamic(sym) || isConstantDynamic(sym)) {
2307 if (isConstantDynamic(sym)) {
2308 setTypeAnnotationPositions(tree.pos);
2309 }
2310 result = items.makeDynamicItem(sym);
2311 } else if (sym.kind == VAR && (sym.owner.kind == MTH || sym.owner.kind == VAR)) {
2312 result = items.makeLocalItem((VarSymbol)sym);
2313 } else if ((sym.flags() & STATIC) != 0) {
2314 if (!isAccessSuper(env.enclMethod))
2315 sym = binaryQualifier(sym, env.enclClass.type);
2316 result = items.makeStaticItem(sym);
2317 } else {
2318 items.makeThisItem().load();
2319 sym = binaryQualifier(sym, env.enclClass.type);
2320 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym));
2321 }
2322 }
2323
2324 //where
2325 private boolean nonVirtualForPrivateAccess(Symbol sym) {
2326 boolean useVirtual = target.hasVirtualPrivateInvoke() &&
2327 !disableVirtualizedPrivateInvoke;
2328 return !useVirtual && ((sym.flags() & PRIVATE) != 0);
2329 }
2330
2331 public void visitSelect(JCFieldAccess tree) {
2332 Symbol sym = tree.sym;
2333
2334 if (tree.name == names._class) {
2335 code.emitLdc((LoadableConstant)checkDimension(tree.pos(), tree.selected.type));
2336 result = items.makeStackItem(pt);
2337 return;
2338 }
2339
2340 Symbol ssym = TreeInfo.symbol(tree.selected);
2341
2342 // Are we selecting via super?
2343 boolean selectSuper =
2344 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2345
2346 // Are we accessing a member of the superclass in an access method
2347 // resulting from a qualified super?
2348 boolean accessSuper = isAccessSuper(env.enclMethod);
2349
2350 Item base = (selectSuper)
2351 ? items.makeSuperItem()
2352 : genExpr(tree.selected, tree.selected.type);
2353
2354 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2355 // We are seeing a variable that is constant but its selecting
2356 // expression is not.
2357 if ((sym.flags() & STATIC) != 0) {
2358 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2359 base = base.load();
2360 base.drop();
2361 } else {
2362 base.load();
2363 genNullCheck(tree.selected);
2364 }
2365 result = items.
2366 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2367 } else {
2368 if (isInvokeDynamic(sym)) {
2369 result = items.makeDynamicItem(sym);
2370 return;
2371 } else {
2372 sym = binaryQualifier(sym, tree.selected.type);
2373 }
2374 if ((sym.flags() & STATIC) != 0) {
2375 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2376 base = base.load();
2377 base.drop();
2378 result = items.makeStaticItem(sym);
2379 } else {
2380 base.load();
2381 if (sym == syms.lengthVar) {
2382 code.emitop0(arraylength);
2383 result = items.makeStackItem(syms.intType);
2384 } else {
2385 result = items.
2386 makeMemberItem(sym,
2387 nonVirtualForPrivateAccess(sym) ||
2388 selectSuper || accessSuper);
2389 }
2390 }
2391 }
2392 }
2393
2394 public boolean isInvokeDynamic(Symbol sym) {
2395 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
2396 }
2397
2398 public void visitLiteral(JCLiteral tree) {
2399 if (tree.type.hasTag(BOT)) {
2400 code.emitop0(aconst_null);
2401 result = items.makeStackItem(tree.type);
2402 }
2403 else
2404 result = items.makeImmediateItem(tree.type, tree.value);
2405 }
2406
2407 public void visitLetExpr(LetExpr tree) {
2408 code.resolvePending();
2409
2410 int limit = code.nextreg;
2411 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
2412 try {
2413 genStats(tree.defs, env);
2414 } finally {
2415 code.setLetExprStackPos(prevLetExprStart);
2416 }
2417 result = genExpr(tree.expr, tree.expr.type).load();
2418 code.endScopes(limit);
2419 }
2420
2421 private void generateReferencesToPrunedTree(ClassSymbol classSymbol) {
2422 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
2423 if (prunedInfo != null) {
2424 for (JCTree prunedTree: prunedInfo) {
2425 prunedTree.accept(classReferenceVisitor);
2426 }
2427 }
2428 }
2429
2430 /* ************************************************************************
2431 * main method
2432 *************************************************************************/
2433
2434 /** Generate code for a class definition.
2435 * @param env The attribution environment that belongs to the
2436 * outermost class containing this class definition.
2437 * We need this for resolving some additional symbols.
2438 * @param cdef The tree representing the class definition.
2439 * @return True if code is generated with no errors.
2440 */
2441 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2442 try {
2443 attrEnv = env;
2444 ClassSymbol c = cdef.sym;
2445 this.toplevel = env.toplevel;
2446 this.endPosTable = toplevel.endPositions;
2447 /* method normalizeDefs() can add references to external classes into the constant pool
2448 */
2449 cdef.defs = normalizeDefs(cdef.defs, c);
2450 generateReferencesToPrunedTree(c);
2451 Env<GenContext> localEnv = new Env<>(cdef, new GenContext());
2452 localEnv.toplevel = env.toplevel;
2453 localEnv.enclClass = cdef;
2454
2455 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2456 genDef(l.head, localEnv);
2457 }
2458 if (poolWriter.size() > PoolWriter.MAX_ENTRIES) {
2459 log.error(cdef.pos(), Errors.LimitPool);
2460 nerrs++;
2461 }
2462 if (nerrs != 0) {
2463 // if errors, discard code
2464 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2465 if (l.head.hasTag(METHODDEF))
2466 ((JCMethodDecl) l.head).sym.code = null;
2467 }
2468 }
2469 cdef.defs = List.nil(); // discard trees
2470 return nerrs == 0;
2471 } finally {
2472 // note: this method does NOT support recursion.
2473 attrEnv = null;
2474 this.env = null;
2475 toplevel = null;
2476 endPosTable = null;
2477 nerrs = 0;
2478 qualifiedSymbolCache.clear();
2479 }
2480 }
2481
2482 /* ************************************************************************
2483 * Auxiliary classes
2484 *************************************************************************/
2485
2486 /** An abstract class for finalizer generation.
2487 */
2488 abstract class GenFinalizer {
2489 /** Generate code to clean up when unwinding. */
2490 abstract void gen();
2491
2492 /** Generate code to clean up at last. */
2493 abstract void genLast();
2494
2495 /** Does this finalizer have some nontrivial cleanup to perform? */
2496 boolean hasFinalizer() { return true; }
2497
2498 /** Should be invoked after the try's body has been visited. */
2499 void afterBody() {}
2500 }
2501
2502 /** code generation contexts,
2503 * to be used as type parameter for environments.
2504 */
2505 static class GenContext {
2506
2507 /** A chain for all unresolved jumps that exit the current environment.
2508 */
2509 Chain exit = null;
2510
2511 /** A chain for all unresolved jumps that continue in the
2512 * current environment.
2513 */
2514 Chain cont = null;
2515
2516 /** A closure that generates the finalizer of the current environment.
2517 * Only set for Synchronized and Try contexts.
2518 */
2519 GenFinalizer finalize = null;
2520
2521 /** Is this a switch statement? If so, allocate registers
2522 * even when the variable declaration is unreachable.
2523 */
2524 boolean isSwitch = false;
2525
2526 /** A list buffer containing all gaps in the finalizer range,
2527 * where a catch all exception should not apply.
2528 */
2529 ListBuffer<Integer> gaps = null;
2530
2531 /** Add given chain to exit chain.
2532 */
2533 void addExit(Chain c) {
2534 exit = Code.mergeChains(c, exit);
2535 }
2536
2537 /** Add given chain to cont chain.
2538 */
2539 void addCont(Chain c) {
2540 cont = Code.mergeChains(c, cont);
2541 }
2542 }
2543
2544 }