1 /*
2 * Copyright (c) 1999, 2019, 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 com.sun.tools.javac.jvm.PoolConstant.LoadableConstant;
29 import com.sun.tools.javac.tree.TreeInfo.PosKind;
30 import com.sun.tools.javac.util.*;
31 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
32 import com.sun.tools.javac.util.List;
33 import com.sun.tools.javac.code.*;
34 import com.sun.tools.javac.code.Attribute.TypeCompound;
35 import com.sun.tools.javac.code.Symbol.VarSymbol;
36 import com.sun.tools.javac.comp.*;
37 import com.sun.tools.javac.tree.*;
38
39 import com.sun.tools.javac.code.Symbol.*;
40 import com.sun.tools.javac.code.Type.*;
41 import com.sun.tools.javac.jvm.Code.*;
42 import com.sun.tools.javac.jvm.Items.*;
43 import com.sun.tools.javac.resources.CompilerProperties.Errors;
44 import com.sun.tools.javac.tree.EndPosTable;
45 import com.sun.tools.javac.tree.JCTree.*;
46
47 import static com.sun.tools.javac.code.Flags.*;
48 import static com.sun.tools.javac.code.Kinds.Kind.*;
49 import static com.sun.tools.javac.code.TypeTag.*;
50 import static com.sun.tools.javac.jvm.ByteCodes.*;
51 import static com.sun.tools.javac.jvm.CRTFlags.*;
52 import static com.sun.tools.javac.main.Option.*;
53 import static com.sun.tools.javac.tree.JCTree.Tag.*;
54
55 /** This pass maps flat Java (i.e. without inner classes) to bytecodes.
56 *
57 * <p><b>This is NOT part of any supported API.
58 * If you write code that depends on this, you do so at your own risk.
59 * This code and its internal interfaces are subject to change or
60 * deletion without notice.</b>
61 */
62 public class Gen extends JCTree.Visitor {
63 protected static final Context.Key<Gen> genKey = new Context.Key<>();
64
65 private final Log log;
66 private final Symtab syms;
67 private final Check chk;
68 private final Resolve rs;
69 private final TreeMaker make;
70 private final Names names;
71 private final Target target;
72 private final Name accessDollar;
73 private final Types types;
74 private final Lower lower;
75 private final Annotate annotate;
76 private final StringConcat concat;
77
78 /** Format of stackmap tables to be generated. */
79 private final Code.StackMapFormat stackMap;
80
81 /** A type that serves as the expected type for all method expressions.
82 */
83 private final Type methodType;
84
85 public static Gen instance(Context context) {
86 Gen instance = context.get(genKey);
87 if (instance == null)
88 instance = new Gen(context);
89 return instance;
90 }
91
92 /** Constant pool writer, set by genClass.
93 */
94 final PoolWriter poolWriter;
95
96 protected Gen(Context context) {
97 context.put(genKey, this);
98
99 names = Names.instance(context);
100 log = Log.instance(context);
101 syms = Symtab.instance(context);
102 chk = Check.instance(context);
103 rs = Resolve.instance(context);
104 make = TreeMaker.instance(context);
105 target = Target.instance(context);
106 types = Types.instance(context);
107 concat = StringConcat.instance(context);
108
109 methodType = new MethodType(null, null, null, syms.methodClass);
110 accessDollar = names.
111 fromString("access" + target.syntheticNameChar());
112 lower = Lower.instance(context);
113
114 Options options = Options.instance(context);
115 lineDebugInfo =
116 options.isUnset(G_CUSTOM) ||
117 options.isSet(G_CUSTOM, "lines");
118 varDebugInfo =
119 options.isUnset(G_CUSTOM)
120 ? options.isSet(G)
121 : options.isSet(G_CUSTOM, "vars");
122 genCrt = options.isSet(XJCOV);
123 debugCode = options.isSet("debug.code");
124 disableVirtualizedPrivateInvoke = options.isSet("disableVirtualizedPrivateInvoke");
125 poolWriter = new PoolWriter(types, names);
126
127 // ignore cldc because we cannot have both stackmap formats
128 this.stackMap = StackMapFormat.JSR202;
129 annotate = Annotate.instance(context);
130 }
131
132 /** Switches
133 */
134 private final boolean lineDebugInfo;
135 private final boolean varDebugInfo;
136 private final boolean genCrt;
137 private final boolean debugCode;
138 private boolean disableVirtualizedPrivateInvoke;
139
140 /** Code buffer, set by genMethod.
141 */
142 private Code code;
143
144 /** Items structure, set by genMethod.
145 */
146 private Items items;
147
148 /** Environment for symbol lookup, set by genClass
149 */
150 private Env<AttrContext> attrEnv;
151
152 /** The top level tree.
153 */
154 private JCCompilationUnit toplevel;
155
156 /** The number of code-gen errors in this class.
157 */
158 private int nerrs = 0;
159
160 /** An object containing mappings of syntax trees to their
161 * ending source positions.
162 */
163 EndPosTable endPosTable;
164
165 boolean inCondSwitchExpression;
166 Chain switchExpressionTrueChain;
167 Chain switchExpressionFalseChain;
168 List<LocalItem> stackBeforeSwitchExpression;
169 LocalItem switchResult;
170
171 /** Generate code to load an integer constant.
172 * @param n The integer to be loaded.
173 */
174 void loadIntConst(int n) {
175 items.makeImmediateItem(syms.intType, n).load();
176 }
177
178 /** The opcode that loads a zero constant of a given type code.
179 * @param tc The given type code (@see ByteCode).
180 */
181 public static int zero(int tc) {
182 switch(tc) {
183 case INTcode: case BYTEcode: case SHORTcode: case CHARcode:
184 return iconst_0;
185 case LONGcode:
186 return lconst_0;
187 case FLOATcode:
188 return fconst_0;
189 case DOUBLEcode:
190 return dconst_0;
191 default:
192 throw new AssertionError("zero");
193 }
194 }
195
196 /** The opcode that loads a one constant of a given type code.
197 * @param tc The given type code (@see ByteCode).
198 */
199 public static int one(int tc) {
200 return zero(tc) + 1;
201 }
202
203 /** Generate code to load -1 of the given type code (either int or long).
204 * @param tc The given type code (@see ByteCode).
205 */
206 void emitMinusOne(int tc) {
207 if (tc == LONGcode) {
208 items.makeImmediateItem(syms.longType, Long.valueOf(-1)).load();
209 } else {
210 code.emitop0(iconst_m1);
211 }
212 }
213
214 /** Construct a symbol to reflect the qualifying type that should
215 * appear in the byte code as per JLS 13.1.
216 *
217 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except
218 * for those cases where we need to work around VM bugs).
219 *
220 * For {@literal target <= 1.1}: If qualified variable or method is defined in a
221 * non-accessible class, clone it with the qualifier class as owner.
222 *
223 * @param sym The accessed symbol
224 * @param site The qualifier's type.
225 */
226 Symbol binaryQualifier(Symbol sym, Type site) {
227
228 if (site.hasTag(ARRAY)) {
229 if (sym == syms.lengthVar ||
230 sym.owner != syms.arrayClass)
231 return sym;
232 // array clone can be qualified by the array type in later targets
233 Symbol qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name,
234 site, syms.noSymbol);
235 return sym.clone(qualifier);
236 }
237
238 if (sym.owner == site.tsym ||
239 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) {
240 return sym;
241 }
242
243 // leave alone methods inherited from Object
244 // JLS 13.1.
245 if (sym.owner == syms.objectType.tsym)
246 return sym;
247
248 return sym.clone(site.tsym);
249 }
250
251 /** Insert a reference to given type in the constant pool,
252 * checking for an array with too many dimensions;
253 * return the reference's index.
254 * @param type The type for which a reference is inserted.
255 */
256 int makeRef(DiagnosticPosition pos, Type type) {
257 return poolWriter.putClass(checkDimension(pos, type));
258 }
259
260 /** Check if the given type is an array with too many dimensions.
261 */
262 private Type checkDimension(DiagnosticPosition pos, Type t) {
263 checkDimensionInternal(pos, t);
264 return t;
265 }
266
267 private void checkDimensionInternal(DiagnosticPosition pos, Type t) {
268 switch (t.getTag()) {
269 case METHOD:
270 checkDimension(pos, t.getReturnType());
271 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail)
272 checkDimension(pos, args.head);
273 break;
274 case ARRAY:
275 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) {
276 log.error(pos, Errors.LimitDimensions);
277 nerrs++;
278 }
279 break;
280 default:
281 break;
282 }
283 }
284
285 /** Create a tempory variable.
286 * @param type The variable's type.
287 */
288 LocalItem makeTemp(Type type) {
289 VarSymbol v = new VarSymbol(Flags.SYNTHETIC,
290 names.empty,
291 type,
292 env.enclMethod.sym);
293 code.newLocal(v);
294 return items.makeLocalItem(v);
295 }
296
297 /** Generate code to call a non-private method or constructor.
298 * @param pos Position to be used for error reporting.
299 * @param site The type of which the method is a member.
300 * @param name The method's name.
301 * @param argtypes The method's argument types.
302 * @param isStatic A flag that indicates whether we call a
303 * static or instance method.
304 */
305 void callMethod(DiagnosticPosition pos,
306 Type site, Name name, List<Type> argtypes,
307 boolean isStatic) {
308 Symbol msym = rs.
309 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null);
310 if (isStatic) items.makeStaticItem(msym).invoke();
311 else items.makeMemberItem(msym, name == names.init).invoke();
312 }
313
314 /** Is the given method definition an access method
315 * resulting from a qualified super? This is signified by an odd
316 * access code.
317 */
318 private boolean isAccessSuper(JCMethodDecl enclMethod) {
319 return
320 (enclMethod.mods.flags & SYNTHETIC) != 0 &&
321 isOddAccessName(enclMethod.name);
322 }
323
324 /** Does given name start with "access$" and end in an odd digit?
325 */
326 private boolean isOddAccessName(Name name) {
327 return
328 name.startsWith(accessDollar) &&
329 (name.getByteAt(name.getByteLength() - 1) & 1) == 1;
330 }
331
332 /* ************************************************************************
333 * Non-local exits
334 *************************************************************************/
335
336 /** Generate code to invoke the finalizer associated with given
337 * environment.
338 * Any calls to finalizers are appended to the environments `cont' chain.
339 * Mark beginning of gap in catch all range for finalizer.
340 */
341 void genFinalizer(Env<GenContext> env) {
342 if (code.isAlive() && env.info.finalize != null)
343 env.info.finalize.gen();
344 }
345
346 /** Generate code to call all finalizers of structures aborted by
347 * a non-local
348 * exit. Return target environment of the non-local exit.
349 * @param target The tree representing the structure that's aborted
350 * @param env The environment current at the non-local exit.
351 */
352 Env<GenContext> unwind(JCTree target, Env<GenContext> env) {
353 Env<GenContext> env1 = env;
354 while (true) {
355 genFinalizer(env1);
356 if (env1.tree == target) break;
357 env1 = env1.next;
358 }
359 return env1;
360 }
361
362 /** Mark end of gap in catch-all range for finalizer.
363 * @param env the environment which might contain the finalizer
364 * (if it does, env.info.gaps != null).
365 */
366 void endFinalizerGap(Env<GenContext> env) {
367 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1)
368 env.info.gaps.append(code.curCP());
369 }
370
371 /** Mark end of all gaps in catch-all ranges for finalizers of environments
372 * lying between, and including to two environments.
373 * @param from the most deeply nested environment to mark
374 * @param to the least deeply nested environment to mark
375 */
376 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) {
377 Env<GenContext> last = null;
378 while (last != to) {
379 endFinalizerGap(from);
380 last = from;
381 from = from.next;
382 }
383 }
384
385 /** Do any of the structures aborted by a non-local exit have
386 * finalizers that require an empty stack?
387 * @param target The tree representing the structure that's aborted
388 * @param env The environment current at the non-local exit.
389 */
390 boolean hasFinally(JCTree target, Env<GenContext> env) {
391 while (env.tree != target) {
392 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer())
393 return true;
394 env = env.next;
395 }
396 return false;
397 }
398
399 /* ************************************************************************
400 * Normalizing class-members.
401 *************************************************************************/
402
403 /** Distribute member initializer code into constructors and {@code <clinit>}
404 * method.
405 * @param defs The list of class member declarations.
406 * @param c The enclosing class.
407 */
408 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) {
409 ListBuffer<JCStatement> initCode = new ListBuffer<>();
410 ListBuffer<Attribute.TypeCompound> initTAs = new ListBuffer<>();
411 ListBuffer<JCStatement> clinitCode = new ListBuffer<>();
412 ListBuffer<Attribute.TypeCompound> clinitTAs = new ListBuffer<>();
413 ListBuffer<JCTree> methodDefs = new ListBuffer<>();
414 // Sort definitions into three listbuffers:
415 // - initCode for instance initializers
416 // - clinitCode for class initializers
417 // - methodDefs for method definitions
418 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
419 JCTree def = l.head;
420 switch (def.getTag()) {
421 case BLOCK:
422 JCBlock block = (JCBlock)def;
423 if ((block.flags & STATIC) != 0)
424 clinitCode.append(block);
425 else if ((block.flags & SYNTHETIC) == 0)
426 initCode.append(block);
427 break;
428 case METHODDEF:
429 methodDefs.append(def);
430 break;
431 case VARDEF:
432 JCVariableDecl vdef = (JCVariableDecl) def;
433 VarSymbol sym = vdef.sym;
434 checkDimension(vdef.pos(), sym.type);
435 if (vdef.init != null) {
436 if ((sym.flags() & STATIC) == 0) {
437 // Always initialize instance variables.
438 JCStatement init = make.at(vdef.pos()).
439 Assignment(sym, vdef.init);
440 initCode.append(init);
441 endPosTable.replaceTree(vdef, init);
442 initTAs.addAll(getAndRemoveNonFieldTAs(sym));
443 } else if (sym.getConstValue() == null) {
444 // Initialize class (static) variables only if
445 // they are not compile-time constants.
446 JCStatement init = make.at(vdef.pos).
447 Assignment(sym, vdef.init);
448 clinitCode.append(init);
449 endPosTable.replaceTree(vdef, init);
450 clinitTAs.addAll(getAndRemoveNonFieldTAs(sym));
451 } else {
452 checkStringConstant(vdef.init.pos(), sym.getConstValue());
453 /* if the init contains a reference to an external class, add it to the
454 * constant's pool
455 */
456 vdef.init.accept(classReferenceVisitor);
457 }
458 }
459 break;
460 default:
461 Assert.error();
462 }
463 }
464 // Insert any instance initializers into all constructors.
465 if (initCode.length() != 0) {
466 List<JCStatement> inits = initCode.toList();
467 initTAs.addAll(c.getInitTypeAttributes());
468 List<Attribute.TypeCompound> initTAlist = initTAs.toList();
469 for (JCTree t : methodDefs) {
470 normalizeMethod((JCMethodDecl)t, inits, initTAlist);
471 }
472 }
473 // If there are class initializers, create a <clinit> method
474 // that contains them as its body.
475 if (clinitCode.length() != 0) {
476 MethodSymbol clinit = new MethodSymbol(
477 STATIC | (c.flags() & STRICTFP),
478 names.clinit,
479 new MethodType(
480 List.nil(), syms.voidType,
481 List.nil(), syms.methodClass),
482 c);
483 c.members().enter(clinit);
484 List<JCStatement> clinitStats = clinitCode.toList();
485 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
486 block.endpos = TreeInfo.endPos(clinitStats.last());
487 methodDefs.append(make.MethodDef(clinit, block));
488
489 if (!clinitTAs.isEmpty())
490 clinit.appendUniqueTypeAttributes(clinitTAs.toList());
491 if (!c.getClassInitTypeAttributes().isEmpty())
492 clinit.appendUniqueTypeAttributes(c.getClassInitTypeAttributes());
493 }
494 // Return all method definitions.
495 return methodDefs.toList();
496 }
497
498 private List<Attribute.TypeCompound> getAndRemoveNonFieldTAs(VarSymbol sym) {
499 List<TypeCompound> tas = sym.getRawTypeAttributes();
500 ListBuffer<Attribute.TypeCompound> fieldTAs = new ListBuffer<>();
501 ListBuffer<Attribute.TypeCompound> nonfieldTAs = new ListBuffer<>();
502 for (TypeCompound ta : tas) {
503 Assert.check(ta.getPosition().type != TargetType.UNKNOWN);
504 if (ta.getPosition().type == TargetType.FIELD) {
505 fieldTAs.add(ta);
506 } else {
507 nonfieldTAs.add(ta);
508 }
509 }
510 sym.setTypeAttributes(fieldTAs.toList());
511 return nonfieldTAs.toList();
512 }
513
514 /** Check a constant value and report if it is a string that is
515 * too large.
516 */
517 private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
518 if (nerrs != 0 || // only complain about a long string once
519 constValue == null ||
520 !(constValue instanceof String) ||
521 ((String)constValue).length() < PoolWriter.MAX_STRING_LENGTH)
522 return;
523 log.error(pos, Errors.LimitString);
524 nerrs++;
525 }
526
527 /** Insert instance initializer code into initial constructor.
528 * @param md The tree potentially representing a
529 * constructor's definition.
530 * @param initCode The list of instance initializer statements.
531 * @param initTAs Type annotations from the initializer expression.
532 */
533 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode, List<TypeCompound> initTAs) {
534 if (md.name == names.init && TreeInfo.isInitialConstructor(md)) {
535 // We are seeing a constructor that does not call another
536 // constructor of the same class.
537 List<JCStatement> stats = md.body.stats;
538 ListBuffer<JCStatement> newstats = new ListBuffer<>();
539
540 if (stats.nonEmpty()) {
541 // Copy initializers of synthetic variables generated in
542 // the translation of inner classes.
543 while (TreeInfo.isSyntheticInit(stats.head)) {
544 newstats.append(stats.head);
545 stats = stats.tail;
546 }
547 // Copy superclass constructor call
548 newstats.append(stats.head);
549 stats = stats.tail;
550 // Copy remaining synthetic initializers.
551 while (stats.nonEmpty() &&
552 TreeInfo.isSyntheticInit(stats.head)) {
553 newstats.append(stats.head);
554 stats = stats.tail;
555 }
556 // Now insert the initializer code.
557 newstats.appendList(initCode);
558 // And copy all remaining statements.
559 while (stats.nonEmpty()) {
560 newstats.append(stats.head);
561 stats = stats.tail;
562 }
563 }
564 md.body.stats = newstats.toList();
565 if (md.body.endpos == Position.NOPOS)
566 md.body.endpos = TreeInfo.endPos(md.body.stats.last());
567
568 md.sym.appendUniqueTypeAttributes(initTAs);
569 }
570 }
571
572 /* ************************************************************************
573 * Traversal methods
574 *************************************************************************/
575
576 /** Visitor argument: The current environment.
577 */
578 Env<GenContext> env;
579
580 /** Visitor argument: The expected type (prototype).
581 */
582 Type pt;
583
584 /** Visitor result: The item representing the computed value.
585 */
586 Item result;
587
588 /** Visitor method: generate code for a definition, catching and reporting
589 * any completion failures.
590 * @param tree The definition to be visited.
591 * @param env The environment current at the definition.
592 */
593 public void genDef(JCTree tree, Env<GenContext> env) {
594 Env<GenContext> prevEnv = this.env;
595 try {
596 this.env = env;
597 tree.accept(this);
598 } catch (CompletionFailure ex) {
599 chk.completionError(tree.pos(), ex);
600 } finally {
601 this.env = prevEnv;
602 }
603 }
604
605 /** Derived visitor method: check whether CharacterRangeTable
606 * should be emitted, if so, put a new entry into CRTable
607 * and call method to generate bytecode.
608 * If not, just call method to generate bytecode.
609 * @see #genStat(JCTree, Env)
610 *
611 * @param tree The tree to be visited.
612 * @param env The environment to use.
613 * @param crtFlags The CharacterRangeTable flags
614 * indicating type of the entry.
615 */
616 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
617 if (!genCrt) {
618 genStat(tree, env);
619 return;
620 }
621 int startpc = code.curCP();
622 genStat(tree, env);
623 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK;
624 code.crt.put(tree, crtFlags, startpc, code.curCP());
625 }
626
627 /** Derived visitor method: generate code for a statement.
628 */
629 public void genStat(JCTree tree, Env<GenContext> env) {
630 if (code.isAlive()) {
631 code.statBegin(tree.pos);
632 genDef(tree, env);
633 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) {
634 // variables whose declarations are in a switch
635 // can be used even if the decl is unreachable.
636 code.newLocal(((JCVariableDecl) tree).sym);
637 }
638 }
639
640 /** Derived visitor method: check whether CharacterRangeTable
641 * should be emitted, if so, put a new entry into CRTable
642 * and call method to generate bytecode.
643 * If not, just call method to generate bytecode.
644 * @see #genStats(List, Env)
645 *
646 * @param trees The list of trees to be visited.
647 * @param env The environment to use.
648 * @param crtFlags The CharacterRangeTable flags
649 * indicating type of the entry.
650 */
651 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
652 if (!genCrt) {
653 genStats(trees, env);
654 return;
655 }
656 if (trees.length() == 1) { // mark one statement with the flags
657 genStat(trees.head, env, crtFlags | CRT_STATEMENT);
658 } else {
659 int startpc = code.curCP();
660 genStats(trees, env);
661 code.crt.put(trees, crtFlags, startpc, code.curCP());
662 }
663 }
664
665 /** Derived visitor method: generate code for a list of statements.
666 */
667 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) {
668 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
669 genStat(l.head, env, CRT_STATEMENT);
670 }
671
672 /** Derived visitor method: check whether CharacterRangeTable
673 * should be emitted, if so, put a new entry into CRTable
674 * and call method to generate bytecode.
675 * If not, just call method to generate bytecode.
676 * @see #genCond(JCTree,boolean)
677 *
678 * @param tree The tree to be visited.
679 * @param crtFlags The CharacterRangeTable flags
680 * indicating type of the entry.
681 */
682 public CondItem genCond(JCTree tree, int crtFlags) {
683 if (!genCrt) return genCond(tree, false);
684 int startpc = code.curCP();
685 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
686 code.crt.put(tree, crtFlags, startpc, code.curCP());
687 return item;
688 }
689
690 /** Derived visitor method: generate code for a boolean
691 * expression in a control-flow context.
692 * @param _tree The expression to be visited.
693 * @param markBranches The flag to indicate that the condition is
694 * a flow controller so produced conditions
695 * should contain a proper tree to generate
696 * CharacterRangeTable branches for them.
697 */
698 public CondItem genCond(JCTree _tree, boolean markBranches) {
699 JCTree inner_tree = TreeInfo.skipParens(_tree);
700 if (inner_tree.hasTag(CONDEXPR)) {
701 JCConditional tree = (JCConditional)inner_tree;
702 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
703 if (cond.isTrue()) {
704 code.resolve(cond.trueJumps);
705 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
706 if (markBranches) result.tree = tree.truepart;
707 return result;
708 }
709 if (cond.isFalse()) {
710 code.resolve(cond.falseJumps);
711 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
712 if (markBranches) result.tree = tree.falsepart;
713 return result;
714 }
715 Chain secondJumps = cond.jumpFalse();
716 code.resolve(cond.trueJumps);
717 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
718 if (markBranches) first.tree = tree.truepart;
719 Chain falseJumps = first.jumpFalse();
720 code.resolve(first.trueJumps);
721 Chain trueJumps = code.branch(goto_);
722 code.resolve(secondJumps);
723 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
724 CondItem result = items.makeCondItem(second.opcode,
725 Code.mergeChains(trueJumps, second.trueJumps),
726 Code.mergeChains(falseJumps, second.falseJumps));
727 if (markBranches) result.tree = tree.falsepart;
728 return result;
729 } else if (inner_tree.hasTag(SWITCH_EXPRESSION)) {
730 code.resolvePending();
731
732 boolean prevInCondSwitchExpression = inCondSwitchExpression;
733 Chain prevSwitchExpressionTrueChain = switchExpressionTrueChain;
734 Chain prevSwitchExpressionFalseChain = switchExpressionFalseChain;
735 try {
736 inCondSwitchExpression = true;
737 switchExpressionTrueChain = null;
738 switchExpressionFalseChain = null;
739 try {
740 doHandleSwitchExpression((JCSwitchExpression) inner_tree);
741 } catch (CompletionFailure ex) {
742 chk.completionError(_tree.pos(), ex);
743 code.state.stacksize = 1;
744 }
745 CondItem result = items.makeCondItem(goto_,
746 switchExpressionTrueChain,
747 switchExpressionFalseChain);
748 if (markBranches) result.tree = _tree;
749 return result;
750 } finally {
751 inCondSwitchExpression = prevInCondSwitchExpression;
752 switchExpressionTrueChain = prevSwitchExpressionTrueChain;
753 switchExpressionFalseChain = prevSwitchExpressionFalseChain;
754 }
755 } else if (inner_tree.hasTag(LETEXPR) && ((LetExpr) inner_tree).needsCond) {
756 code.resolvePending();
757
758 LetExpr tree = (LetExpr) inner_tree;
759 int limit = code.nextreg;
760 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
761 try {
762 genStats(tree.defs, env);
763 } finally {
764 code.setLetExprStackPos(prevLetExprStart);
765 }
766 CondItem result = genCond(tree.expr, markBranches);
767 code.endScopes(limit);
768 return result;
769 } else {
770 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
771 if (markBranches) result.tree = _tree;
772 return result;
773 }
774 }
775
776 public Code getCode() {
777 return code;
778 }
779
780 public Items getItems() {
781 return items;
782 }
783
784 public Env<AttrContext> getAttrEnv() {
785 return attrEnv;
786 }
787
788 /** Visitor class for expressions which might be constant expressions.
789 * This class is a subset of TreeScanner. Intended to visit trees pruned by
790 * Lower as long as constant expressions looking for references to any
791 * ClassSymbol. Any such reference will be added to the constant pool so
792 * automated tools can detect class dependencies better.
793 */
794 class ClassReferenceVisitor extends JCTree.Visitor {
795
796 @Override
797 public void visitTree(JCTree tree) {}
798
799 @Override
800 public void visitBinary(JCBinary tree) {
801 tree.lhs.accept(this);
802 tree.rhs.accept(this);
803 }
804
805 @Override
806 public void visitSelect(JCFieldAccess tree) {
807 if (tree.selected.type.hasTag(CLASS)) {
808 makeRef(tree.selected.pos(), tree.selected.type);
809 }
810 }
811
812 @Override
813 public void visitIdent(JCIdent tree) {
814 if (tree.sym.owner instanceof ClassSymbol) {
815 poolWriter.putClass((ClassSymbol)tree.sym.owner);
816 }
817 }
818
819 @Override
820 public void visitConditional(JCConditional tree) {
821 tree.cond.accept(this);
822 tree.truepart.accept(this);
823 tree.falsepart.accept(this);
824 }
825
826 @Override
827 public void visitUnary(JCUnary tree) {
828 tree.arg.accept(this);
829 }
830
831 @Override
832 public void visitParens(JCParens tree) {
833 tree.expr.accept(this);
834 }
835
836 @Override
837 public void visitTypeCast(JCTypeCast tree) {
838 tree.expr.accept(this);
839 }
840 }
841
842 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor();
843
844 /** Visitor method: generate code for an expression, catching and reporting
845 * any completion failures.
846 * @param tree The expression to be visited.
847 * @param pt The expression's expected type (proto-type).
848 */
849 public Item genExpr(JCTree tree, Type pt) {
850 Type prevPt = this.pt;
851 try {
852 if (tree.type.constValue() != null) {
853 // Short circuit any expressions which are constants
854 tree.accept(classReferenceVisitor);
855 checkStringConstant(tree.pos(), tree.type.constValue());
856 Symbol sym = TreeInfo.symbol(tree);
857 if (sym != null && isConstantDynamic(sym)) {
858 result = items.makeDynamicItem(sym);
859 } else {
860 result = items.makeImmediateItem(tree.type, tree.type.constValue());
861 }
862 } else {
863 this.pt = pt;
864 tree.accept(this);
865 }
866 return result.coerce(pt);
867 } catch (CompletionFailure ex) {
868 chk.completionError(tree.pos(), ex);
869 code.state.stacksize = 1;
870 return items.makeStackItem(pt);
871 } finally {
872 this.pt = prevPt;
873 }
874 }
875
876 public boolean isConstantDynamic(Symbol sym) {
877 return sym.kind == VAR &&
878 sym instanceof DynamicVarSymbol &&
879 ((DynamicVarSymbol)sym).isDynamic();
880 }
881
882 /** Derived visitor method: generate code for a list of method arguments.
883 * @param trees The argument expressions to be visited.
884 * @param pts The expression's expected types (i.e. the formal parameter
885 * types of the invoked method).
886 */
887 public void genArgs(List<JCExpression> trees, List<Type> pts) {
888 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
889 genExpr(l.head, pts.head).load();
890 pts = pts.tail;
891 }
892 // require lists be of same length
893 Assert.check(pts.isEmpty());
894 }
895
896 /* ************************************************************************
897 * Visitor methods for statements and definitions
898 *************************************************************************/
899
900 /** Thrown when the byte code size exceeds limit.
901 */
902 public static class CodeSizeOverflow extends RuntimeException {
903 private static final long serialVersionUID = 0;
904 public CodeSizeOverflow() {}
905 }
906
907 public void visitMethodDef(JCMethodDecl tree) {
908 // Create a new local environment that points pack at method
909 // definition.
910 Env<GenContext> localEnv = env.dup(tree);
911 localEnv.enclMethod = tree;
912 // The expected type of every return statement in this method
913 // is the method's return type.
914 this.pt = tree.sym.erasure(types).getReturnType();
915
916 checkDimension(tree.pos(), tree.sym.erasure(types));
917 genMethod(tree, localEnv, false);
918 }
919 //where
920 /** Generate code for a method.
921 * @param tree The tree representing the method definition.
922 * @param env The environment current for the method body.
923 * @param fatcode A flag that indicates whether all jumps are
924 * within 32K. We first invoke this method under
925 * the assumption that fatcode == false, i.e. all
926 * jumps are within 32K. If this fails, fatcode
927 * is set to true and we try again.
928 */
929 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
930 MethodSymbol meth = tree.sym;
931 int extras = 0;
932 // Count up extra parameters
933 if (meth.isConstructor()) {
934 extras++;
935 if (meth.enclClass().isInner() &&
936 !meth.enclClass().isStatic()) {
937 extras++;
938 }
939 } else if ((tree.mods.flags & STATIC) == 0) {
940 extras++;
941 }
942 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
943 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) + extras >
944 ClassFile.MAX_PARAMETERS) {
945 log.error(tree.pos(), Errors.LimitParameters);
946 nerrs++;
947 }
948
949 else if (tree.body != null) {
950 // Create a new code structure and initialize it.
951 int startpcCrt = initCode(tree, env, fatcode);
952
953 try {
954 genStat(tree.body, env);
955 } catch (CodeSizeOverflow e) {
956 // Failed due to code limit, try again with jsr/ret
957 startpcCrt = initCode(tree, env, fatcode);
958 genStat(tree.body, env);
959 }
960
961 if (code.state.stacksize != 0) {
962 log.error(tree.body.pos(), Errors.StackSimError(tree.sym));
963 throw new AssertionError();
964 }
965
966 // If last statement could complete normally, insert a
967 // return at the end.
968 if (code.isAlive()) {
969 code.statBegin(TreeInfo.endPos(tree.body));
970 if (env.enclMethod == null ||
971 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
972 code.emitop0(return_);
973 } else {
974 // sometime dead code seems alive (4415991);
975 // generate a small loop instead
976 int startpc = code.entryPoint();
977 CondItem c = items.makeCondItem(goto_);
978 code.resolve(c.jumpTrue(), startpc);
979 }
980 }
981 if (genCrt)
982 code.crt.put(tree.body,
983 CRT_BLOCK,
984 startpcCrt,
985 code.curCP());
986
987 code.endScopes(0);
988
989 // If we exceeded limits, panic
990 if (code.checkLimits(tree.pos(), log)) {
991 nerrs++;
992 return;
993 }
994
995 // If we generated short code but got a long jump, do it again
996 // with fatCode = true.
997 if (!fatcode && code.fatcode) genMethod(tree, env, true);
998
999 // Clean up
1000 if(stackMap == StackMapFormat.JSR202) {
1001 code.lastFrame = null;
1002 code.frameBeforeLast = null;
1003 }
1004
1005 // Compress exception table
1006 code.compressCatchTable();
1007
1008 // Fill in type annotation positions for exception parameters
1009 code.fillExceptionParameterPositions();
1010 }
1011 }
1012
1013 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1014 MethodSymbol meth = tree.sym;
1015
1016 // Create a new code structure.
1017 meth.code = code = new Code(meth,
1018 fatcode,
1019 lineDebugInfo ? toplevel.lineMap : null,
1020 varDebugInfo,
1021 stackMap,
1022 debugCode,
1023 genCrt ? new CRTable(tree, env.toplevel.endPositions)
1024 : null,
1025 syms,
1026 types,
1027 poolWriter);
1028 items = new Items(poolWriter, code, syms, types);
1029 if (code.debugCode) {
1030 System.err.println(meth + " for body " + tree);
1031 }
1032
1033 // If method is not static, create a new local variable address
1034 // for `this'.
1035 if ((tree.mods.flags & STATIC) == 0) {
1036 Type selfType = meth.owner.type;
1037 if (meth.isConstructor() && selfType != syms.objectType)
1038 selfType = UninitializedType.uninitializedThis(selfType);
1039 code.setDefined(
1040 code.newLocal(
1041 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1042 }
1043
1044 // Mark all parameters as defined from the beginning of
1045 // the method.
1046 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1047 checkDimension(l.head.pos(), l.head.sym.type);
1048 code.setDefined(code.newLocal(l.head.sym));
1049 }
1050
1051 // Get ready to generate code for method body.
1052 int startpcCrt = genCrt ? code.curCP() : 0;
1053 code.entryPoint();
1054
1055 // Suppress initial stackmap
1056 code.pendingStackMap = false;
1057
1058 return startpcCrt;
1059 }
1060
1061 public void visitVarDef(JCVariableDecl tree) {
1062 VarSymbol v = tree.sym;
1063 if (tree.init != null) {
1064 checkStringConstant(tree.init.pos(), v.getConstValue());
1065 if (v.getConstValue() == null || varDebugInfo) {
1066 Assert.check(code.isStatementStart());
1067 code.newLocal(v);
1068 genExpr(tree.init, v.erasure(types)).load();
1069 items.makeLocalItem(v).store();
1070 Assert.check(code.isStatementStart());
1071 }
1072 } else {
1073 code.newLocal(v);
1074 }
1075 checkDimension(tree.pos(), v.type);
1076 }
1077
1078 public void visitSkip(JCSkip tree) {
1079 }
1080
1081 public void visitBlock(JCBlock tree) {
1082 int limit = code.nextreg;
1083 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1084 genStats(tree.stats, localEnv);
1085 // End the scope of all block-local variables in variable info.
1086 if (!env.tree.hasTag(METHODDEF)) {
1087 code.statBegin(tree.endpos);
1088 code.endScopes(limit);
1089 code.pendingStatPos = Position.NOPOS;
1090 }
1091 }
1092
1093 public void visitDoLoop(JCDoWhileLoop tree) {
1094 genLoop(tree, tree.body, tree.cond, List.nil(), false);
1095 }
1096
1097 public void visitWhileLoop(JCWhileLoop tree) {
1098 genLoop(tree, tree.body, tree.cond, List.nil(), true);
1099 }
1100
1101 public void visitForLoop(JCForLoop tree) {
1102 int limit = code.nextreg;
1103 genStats(tree.init, env);
1104 genLoop(tree, tree.body, tree.cond, tree.step, true);
1105 code.endScopes(limit);
1106 }
1107 //where
1108 /** Generate code for a loop.
1109 * @param loop The tree representing the loop.
1110 * @param body The loop's body.
1111 * @param cond The loop's controling condition.
1112 * @param step "Step" statements to be inserted at end of
1113 * each iteration.
1114 * @param testFirst True if the loop test belongs before the body.
1115 */
1116 private void genLoop(JCStatement loop,
1117 JCStatement body,
1118 JCExpression cond,
1119 List<JCExpressionStatement> step,
1120 boolean testFirst) {
1121 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1122 int startpc = code.entryPoint();
1123 if (testFirst) { //while or for loop
1124 CondItem c;
1125 if (cond != null) {
1126 code.statBegin(cond.pos);
1127 Assert.check(code.isStatementStart());
1128 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1129 } else {
1130 c = items.makeCondItem(goto_);
1131 }
1132 Chain loopDone = c.jumpFalse();
1133 code.resolve(c.trueJumps);
1134 Assert.check(code.isStatementStart());
1135 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1136 code.resolve(loopEnv.info.cont);
1137 genStats(step, loopEnv);
1138 code.resolve(code.branch(goto_), startpc);
1139 code.resolve(loopDone);
1140 } else {
1141 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1142 code.resolve(loopEnv.info.cont);
1143 genStats(step, loopEnv);
1144 if (code.isAlive()) {
1145 CondItem c;
1146 if (cond != null) {
1147 code.statBegin(cond.pos);
1148 Assert.check(code.isStatementStart());
1149 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1150 } else {
1151 c = items.makeCondItem(goto_);
1152 }
1153 code.resolve(c.jumpTrue(), startpc);
1154 Assert.check(code.isStatementStart());
1155 code.resolve(c.falseJumps);
1156 }
1157 }
1158 Chain exit = loopEnv.info.exit;
1159 if (exit != null) {
1160 code.resolve(exit);
1161 exit.state.defined.excludeFrom(code.nextreg);
1162 }
1163 }
1164
1165 public void visitForeachLoop(JCEnhancedForLoop tree) {
1166 throw new AssertionError(); // should have been removed by Lower.
1167 }
1168
1169 public void visitLabelled(JCLabeledStatement tree) {
1170 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1171 genStat(tree.body, localEnv, CRT_STATEMENT);
1172 Chain exit = localEnv.info.exit;
1173 if (exit != null) {
1174 code.resolve(exit);
1175 exit.state.defined.excludeFrom(code.nextreg);
1176 }
1177 }
1178
1179 public void visitSwitch(JCSwitch tree) {
1180 handleSwitch(tree, tree.selector, tree.cases);
1181 }
1182
1183 @Override
1184 public void visitSwitchExpression(JCSwitchExpression tree) {
1185 code.resolvePending();
1186 boolean prevInCondSwitchExpression = inCondSwitchExpression;
1187 try {
1188 inCondSwitchExpression = false;
1189 doHandleSwitchExpression(tree);
1190 } finally {
1191 inCondSwitchExpression = prevInCondSwitchExpression;
1192 }
1193 result = items.makeStackItem(pt);
1194 }
1195
1196 private void doHandleSwitchExpression(JCSwitchExpression tree) {
1197 List<LocalItem> prevStackBeforeSwitchExpression = stackBeforeSwitchExpression;
1198 LocalItem prevSwitchResult = switchResult;
1199 int limit = code.nextreg;
1200 try {
1201 stackBeforeSwitchExpression = List.nil();
1202 switchResult = null;
1203 if (hasTry(tree)) {
1204 //if the switch expression contains try-catch, the catch handlers need to have
1205 //an empty stack. So stash whole stack to local variables, and restore it before
1206 //breaks:
1207 while (code.state.stacksize > 0) {
1208 Type type = code.state.peek();
1209 Name varName = names.fromString(target.syntheticNameChar() +
1210 "stack" +
1211 target.syntheticNameChar() +
1212 tree.pos +
1213 target.syntheticNameChar() +
1214 code.state.stacksize);
1215 VarSymbol var = new VarSymbol(Flags.SYNTHETIC, varName, type,
1216 this.env.enclMethod.sym);
1217 LocalItem item = items.new LocalItem(type, code.newLocal(var));
1218 stackBeforeSwitchExpression = stackBeforeSwitchExpression.prepend(item);
1219 item.store();
1220 }
1221 switchResult = makeTemp(tree.type);
1222 }
1223 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
1224 try {
1225 handleSwitch(tree, tree.selector, tree.cases);
1226 } finally {
1227 code.setLetExprStackPos(prevLetExprStart);
1228 }
1229 } finally {
1230 stackBeforeSwitchExpression = prevStackBeforeSwitchExpression;
1231 switchResult = prevSwitchResult;
1232 code.endScopes(limit);
1233 }
1234 }
1235 //where:
1236 private boolean hasTry(JCSwitchExpression tree) {
1237 boolean[] hasTry = new boolean[1];
1238 new TreeScanner() {
1239 @Override
1240 public void visitTry(JCTry tree) {
1241 hasTry[0] = true;
1242 }
1243
1244 @Override
1245 public void visitClassDef(JCClassDecl tree) {
1246 }
1247
1248 @Override
1249 public void visitLambda(JCLambda tree) {
1250 }
1251 }.scan(tree);
1252 return hasTry[0];
1253 }
1254
1255 private void handleSwitch(JCTree swtch, JCExpression selector, List<JCCase> cases) {
1256 int limit = code.nextreg;
1257 Assert.check(!selector.type.hasTag(CLASS));
1258 int startpcCrt = genCrt ? code.curCP() : 0;
1259 Assert.check(code.isStatementStart());
1260 Item sel = genExpr(selector, syms.intType);
1261 if (cases.isEmpty()) {
1262 // We are seeing: switch <sel> {}
1263 sel.load().drop();
1264 if (genCrt)
1265 code.crt.put(TreeInfo.skipParens(selector),
1266 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1267 } else {
1268 // We are seeing a nonempty switch.
1269 sel.load();
1270 if (genCrt)
1271 code.crt.put(TreeInfo.skipParens(selector),
1272 CRT_FLOW_CONTROLLER, startpcCrt, code.curCP());
1273 Env<GenContext> switchEnv = env.dup(swtch, new GenContext());
1274 switchEnv.info.isSwitch = true;
1275
1276 // Compute number of labels and minimum and maximum label values.
1277 // For each case, store its label in an array.
1278 int lo = Integer.MAX_VALUE; // minimum label.
1279 int hi = Integer.MIN_VALUE; // maximum label.
1280 int nlabels = 0; // number of labels.
1281
1282 int[] labels = new int[cases.length()]; // the label array.
1283 int defaultIndex = -1; // the index of the default clause.
1284
1285 List<JCCase> l = cases;
1286 for (int i = 0; i < labels.length; i++) {
1287 if (l.head.pats.nonEmpty()) {
1288 Assert.check(l.head.pats.size() == 1);
1289 int val = ((Number)l.head.pats.head.type.constValue()).intValue();
1290 labels[i] = val;
1291 if (val < lo) lo = val;
1292 if (hi < val) hi = val;
1293 nlabels++;
1294 } else {
1295 Assert.check(defaultIndex == -1);
1296 defaultIndex = i;
1297 }
1298 l = l.tail;
1299 }
1300
1301 // Determine whether to issue a tableswitch or a lookupswitch
1302 // instruction.
1303 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1304 long table_time_cost = 3; // comparisons
1305 long lookup_space_cost = 3 + 2 * (long) nlabels;
1306 long lookup_time_cost = nlabels;
1307 int opcode =
1308 nlabels > 0 &&
1309 table_space_cost + 3 * table_time_cost <=
1310 lookup_space_cost + 3 * lookup_time_cost
1311 ?
1312 tableswitch : lookupswitch;
1313
1314 int startpc = code.curCP(); // the position of the selector operation
1315 code.emitop0(opcode);
1316 code.align(4);
1317 int tableBase = code.curCP(); // the start of the jump table
1318 int[] offsets = null; // a table of offsets for a lookupswitch
1319 code.emit4(-1); // leave space for default offset
1320 if (opcode == tableswitch) {
1321 code.emit4(lo); // minimum label
1322 code.emit4(hi); // maximum label
1323 for (long i = lo; i <= hi; i++) { // leave space for jump table
1324 code.emit4(-1);
1325 }
1326 } else {
1327 code.emit4(nlabels); // number of labels
1328 for (int i = 0; i < nlabels; i++) {
1329 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1330 }
1331 offsets = new int[labels.length];
1332 }
1333 Code.State stateSwitch = code.state.dup();
1334 code.markDead();
1335
1336 // For each case do:
1337 l = cases;
1338 for (int i = 0; i < labels.length; i++) {
1339 JCCase c = l.head;
1340 l = l.tail;
1341
1342 int pc = code.entryPoint(stateSwitch);
1343 // Insert offset directly into code or else into the
1344 // offsets table.
1345 if (i != defaultIndex) {
1346 if (opcode == tableswitch) {
1347 code.put4(
1348 tableBase + 4 * (labels[i] - lo + 3),
1349 pc - startpc);
1350 } else {
1351 offsets[i] = pc - startpc;
1352 }
1353 } else {
1354 code.put4(tableBase, pc - startpc);
1355 }
1356
1357 // Generate code for the statements in this case.
1358 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1359 }
1360
1361 // Resolve all breaks.
1362 Chain exit = switchEnv.info.exit;
1363 if (exit != null) {
1364 code.resolve(exit);
1365 exit.state.defined.excludeFrom(limit);
1366 }
1367
1368 // If we have not set the default offset, we do so now.
1369 if (code.get4(tableBase) == -1) {
1370 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1371 }
1372
1373 if (opcode == tableswitch) {
1374 // Let any unfilled slots point to the default case.
1375 int defaultOffset = code.get4(tableBase);
1376 for (long i = lo; i <= hi; i++) {
1377 int t = (int)(tableBase + 4 * (i - lo + 3));
1378 if (code.get4(t) == -1)
1379 code.put4(t, defaultOffset);
1380 }
1381 } else {
1382 // Sort non-default offsets and copy into lookup table.
1383 if (defaultIndex >= 0)
1384 for (int i = defaultIndex; i < labels.length - 1; i++) {
1385 labels[i] = labels[i+1];
1386 offsets[i] = offsets[i+1];
1387 }
1388 if (nlabels > 0)
1389 qsort2(labels, offsets, 0, nlabels - 1);
1390 for (int i = 0; i < nlabels; i++) {
1391 int caseidx = tableBase + 8 * (i + 1);
1392 code.put4(caseidx, labels[i]);
1393 code.put4(caseidx + 4, offsets[i]);
1394 }
1395 }
1396 }
1397 code.endScopes(limit);
1398 }
1399 //where
1400 /** Sort (int) arrays of keys and values
1401 */
1402 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1403 int i = lo;
1404 int j = hi;
1405 int pivot = keys[(i+j)/2];
1406 do {
1407 while (keys[i] < pivot) i++;
1408 while (pivot < keys[j]) j--;
1409 if (i <= j) {
1410 int temp1 = keys[i];
1411 keys[i] = keys[j];
1412 keys[j] = temp1;
1413 int temp2 = values[i];
1414 values[i] = values[j];
1415 values[j] = temp2;
1416 i++;
1417 j--;
1418 }
1419 } while (i <= j);
1420 if (lo < j) qsort2(keys, values, lo, j);
1421 if (i < hi) qsort2(keys, values, i, hi);
1422 }
1423
1424 public void visitSynchronized(JCSynchronized tree) {
1425 int limit = code.nextreg;
1426 // Generate code to evaluate lock and save in temporary variable.
1427 final LocalItem lockVar = makeTemp(syms.objectType);
1428 Assert.check(code.isStatementStart());
1429 genExpr(tree.lock, tree.lock.type).load().duplicate();
1430 lockVar.store();
1431
1432 // Generate code to enter monitor.
1433 code.emitop0(monitorenter);
1434 code.state.lock(lockVar.reg);
1435
1436 // Generate code for a try statement with given body, no catch clauses
1437 // in a new environment with the "exit-monitor" operation as finalizer.
1438 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1439 syncEnv.info.finalize = new GenFinalizer() {
1440 void gen() {
1441 genLast();
1442 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1443 syncEnv.info.gaps.append(code.curCP());
1444 }
1445 void genLast() {
1446 if (code.isAlive()) {
1447 lockVar.load();
1448 code.emitop0(monitorexit);
1449 code.state.unlock(lockVar.reg);
1450 }
1451 }
1452 };
1453 syncEnv.info.gaps = new ListBuffer<>();
1454 genTry(tree.body, List.nil(), syncEnv);
1455 code.endScopes(limit);
1456 }
1457
1458 public void visitTry(final JCTry tree) {
1459 // Generate code for a try statement with given body and catch clauses,
1460 // in a new environment which calls the finally block if there is one.
1461 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1462 final Env<GenContext> oldEnv = env;
1463 tryEnv.info.finalize = new GenFinalizer() {
1464 void gen() {
1465 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1466 tryEnv.info.gaps.append(code.curCP());
1467 genLast();
1468 }
1469 void genLast() {
1470 if (tree.finalizer != null)
1471 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1472 }
1473 boolean hasFinalizer() {
1474 return tree.finalizer != null;
1475 }
1476
1477 @Override
1478 void afterBody() {
1479 if (tree.finalizer != null && (tree.finalizer.flags & BODY_ONLY_FINALIZE) != 0) {
1480 //for body-only finally, remove the GenFinalizer after try body
1481 //so that the finally is not generated to catch bodies:
1482 tryEnv.info.finalize = null;
1483 }
1484 }
1485
1486 };
1487 tryEnv.info.gaps = new ListBuffer<>();
1488 genTry(tree.body, tree.catchers, tryEnv);
1489 }
1490 //where
1491 /** Generate code for a try or synchronized statement
1492 * @param body The body of the try or synchronized statement.
1493 * @param catchers The lis of catch clauses.
1494 * @param env the environment current for the body.
1495 */
1496 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1497 int limit = code.nextreg;
1498 int startpc = code.curCP();
1499 Code.State stateTry = code.state.dup();
1500 genStat(body, env, CRT_BLOCK);
1501 int endpc = code.curCP();
1502 List<Integer> gaps = env.info.gaps.toList();
1503 code.statBegin(TreeInfo.endPos(body));
1504 genFinalizer(env);
1505 code.statBegin(TreeInfo.endPos(env.tree));
1506 Chain exitChain = code.branch(goto_);
1507 endFinalizerGap(env);
1508 env.info.finalize.afterBody();
1509 boolean hasFinalizer =
1510 env.info.finalize != null &&
1511 env.info.finalize.hasFinalizer();
1512 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1513 // start off with exception on stack
1514 code.entryPoint(stateTry, l.head.param.sym.type);
1515 genCatch(l.head, env, startpc, endpc, gaps);
1516 genFinalizer(env);
1517 if (hasFinalizer || l.tail.nonEmpty()) {
1518 code.statBegin(TreeInfo.endPos(env.tree));
1519 exitChain = Code.mergeChains(exitChain,
1520 code.branch(goto_));
1521 }
1522 endFinalizerGap(env);
1523 }
1524 if (hasFinalizer) {
1525 // Create a new register segement to avoid allocating
1526 // the same variables in finalizers and other statements.
1527 code.newRegSegment();
1528
1529 // Add a catch-all clause.
1530
1531 // start off with exception on stack
1532 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1533
1534 // Register all exception ranges for catch all clause.
1535 // The range of the catch all clause is from the beginning
1536 // of the try or synchronized block until the present
1537 // code pointer excluding all gaps in the current
1538 // environment's GenContext.
1539 int startseg = startpc;
1540 while (env.info.gaps.nonEmpty()) {
1541 int endseg = env.info.gaps.next().intValue();
1542 registerCatch(body.pos(), startseg, endseg,
1543 catchallpc, 0);
1544 startseg = env.info.gaps.next().intValue();
1545 }
1546 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1547 code.markStatBegin();
1548
1549 Item excVar = makeTemp(syms.throwableType);
1550 excVar.store();
1551 genFinalizer(env);
1552 code.resolvePending();
1553 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.END_POS));
1554 code.markStatBegin();
1555
1556 excVar.load();
1557 registerCatch(body.pos(), startseg,
1558 env.info.gaps.next().intValue(),
1559 catchallpc, 0);
1560 code.emitop0(athrow);
1561 code.markDead();
1562
1563 // If there are jsr's to this finalizer, ...
1564 if (env.info.cont != null) {
1565 // Resolve all jsr's.
1566 code.resolve(env.info.cont);
1567
1568 // Mark statement line number
1569 code.statBegin(TreeInfo.finalizerPos(env.tree, PosKind.FIRST_STAT_POS));
1570 code.markStatBegin();
1571
1572 // Save return address.
1573 LocalItem retVar = makeTemp(syms.throwableType);
1574 retVar.store();
1575
1576 // Generate finalizer code.
1577 env.info.finalize.genLast();
1578
1579 // Return.
1580 code.emitop1w(ret, retVar.reg);
1581 code.markDead();
1582 }
1583 }
1584 // Resolve all breaks.
1585 code.resolve(exitChain);
1586
1587 code.endScopes(limit);
1588 }
1589
1590 /** Generate code for a catch clause.
1591 * @param tree The catch clause.
1592 * @param env The environment current in the enclosing try.
1593 * @param startpc Start pc of try-block.
1594 * @param endpc End pc of try-block.
1595 */
1596 void genCatch(JCCatch tree,
1597 Env<GenContext> env,
1598 int startpc, int endpc,
1599 List<Integer> gaps) {
1600 if (startpc != endpc) {
1601 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypeExprs
1602 = catchTypesWithAnnotations(tree);
1603 while (gaps.nonEmpty()) {
1604 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1605 JCExpression subCatch = subCatch1.snd;
1606 int catchType = makeRef(tree.pos(), subCatch.type);
1607 int end = gaps.head.intValue();
1608 registerCatch(tree.pos(),
1609 startpc, end, code.curCP(),
1610 catchType);
1611 for (Attribute.TypeCompound tc : subCatch1.fst) {
1612 tc.position.setCatchInfo(catchType, startpc);
1613 }
1614 }
1615 gaps = gaps.tail;
1616 startpc = gaps.head.intValue();
1617 gaps = gaps.tail;
1618 }
1619 if (startpc < endpc) {
1620 for (Pair<List<Attribute.TypeCompound>, JCExpression> subCatch1 : catchTypeExprs) {
1621 JCExpression subCatch = subCatch1.snd;
1622 int catchType = makeRef(tree.pos(), subCatch.type);
1623 registerCatch(tree.pos(),
1624 startpc, endpc, code.curCP(),
1625 catchType);
1626 for (Attribute.TypeCompound tc : subCatch1.fst) {
1627 tc.position.setCatchInfo(catchType, startpc);
1628 }
1629 }
1630 }
1631 VarSymbol exparam = tree.param.sym;
1632 code.statBegin(tree.pos);
1633 code.markStatBegin();
1634 int limit = code.nextreg;
1635 code.newLocal(exparam);
1636 items.makeLocalItem(exparam).store();
1637 code.statBegin(TreeInfo.firstStatPos(tree.body));
1638 genStat(tree.body, env, CRT_BLOCK);
1639 code.endScopes(limit);
1640 code.statBegin(TreeInfo.endPos(tree.body));
1641 }
1642 }
1643 // where
1644 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotations(JCCatch tree) {
1645 return TreeInfo.isMultiCatch(tree) ?
1646 catchTypesWithAnnotationsFromMulticatch((JCTypeUnion)tree.param.vartype, tree.param.sym.getRawTypeAttributes()) :
1647 List.of(new Pair<>(tree.param.sym.getRawTypeAttributes(), tree.param.vartype));
1648 }
1649 // where
1650 List<Pair<List<Attribute.TypeCompound>, JCExpression>> catchTypesWithAnnotationsFromMulticatch(JCTypeUnion tree, List<TypeCompound> first) {
1651 List<JCExpression> alts = tree.alternatives;
1652 List<Pair<List<TypeCompound>, JCExpression>> res = List.of(new Pair<>(first, alts.head));
1653 alts = alts.tail;
1654
1655 while(alts != null && alts.head != null) {
1656 JCExpression alt = alts.head;
1657 if (alt instanceof JCAnnotatedType) {
1658 JCAnnotatedType a = (JCAnnotatedType)alt;
1659 res = res.prepend(new Pair<>(annotate.fromAnnotations(a.annotations), alt));
1660 } else {
1661 res = res.prepend(new Pair<>(List.nil(), alt));
1662 }
1663 alts = alts.tail;
1664 }
1665 return res.reverse();
1666 }
1667
1668 /** Register a catch clause in the "Exceptions" code-attribute.
1669 */
1670 void registerCatch(DiagnosticPosition pos,
1671 int startpc, int endpc,
1672 int handler_pc, int catch_type) {
1673 char startpc1 = (char)startpc;
1674 char endpc1 = (char)endpc;
1675 char handler_pc1 = (char)handler_pc;
1676 if (startpc1 == startpc &&
1677 endpc1 == endpc &&
1678 handler_pc1 == handler_pc) {
1679 code.addCatch(startpc1, endpc1, handler_pc1,
1680 (char)catch_type);
1681 } else {
1682 log.error(pos, Errors.LimitCodeTooLargeForTryStmt);
1683 nerrs++;
1684 }
1685 }
1686
1687 public void visitIf(JCIf tree) {
1688 int limit = code.nextreg;
1689 Chain thenExit = null;
1690 Assert.check(code.isStatementStart());
1691 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1692 CRT_FLOW_CONTROLLER);
1693 Chain elseChain = c.jumpFalse();
1694 Assert.check(code.isStatementStart());
1695 if (!c.isFalse()) {
1696 code.resolve(c.trueJumps);
1697 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1698 thenExit = code.branch(goto_);
1699 }
1700 if (elseChain != null) {
1701 code.resolve(elseChain);
1702 if (tree.elsepart != null) {
1703 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1704 }
1705 }
1706 code.resolve(thenExit);
1707 code.endScopes(limit);
1708 Assert.check(code.isStatementStart());
1709 }
1710
1711 public void visitExec(JCExpressionStatement tree) {
1712 // Optimize x++ to ++x and x-- to --x.
1713 JCExpression e = tree.expr;
1714 switch (e.getTag()) {
1715 case POSTINC:
1716 ((JCUnary) e).setTag(PREINC);
1717 break;
1718 case POSTDEC:
1719 ((JCUnary) e).setTag(PREDEC);
1720 break;
1721 }
1722 Assert.check(code.isStatementStart());
1723 genExpr(tree.expr, tree.expr.type).drop();
1724 Assert.check(code.isStatementStart());
1725 }
1726
1727 public void visitBreak(JCBreak tree) {
1728 Assert.check(code.isStatementStart());
1729 final Env<GenContext> targetEnv = unwindBreak(tree.target);
1730 targetEnv.info.addExit(code.branch(goto_));
1731 endFinalizerGaps(env, targetEnv);
1732 }
1733
1734 public void visitYield(JCYield tree) {
1735 Assert.check(code.isStatementStart());
1736 final Env<GenContext> targetEnv;
1737 if (inCondSwitchExpression) {
1738 CondItem value = genCond(tree.value, CRT_FLOW_TARGET);
1739 Chain falseJumps = value.jumpFalse();
1740
1741 code.resolve(value.trueJumps);
1742 Env<GenContext> localEnv = unwindBreak(tree.target);
1743 reloadStackBeforeSwitchExpr();
1744 Chain trueJumps = code.branch(goto_);
1745
1746 endFinalizerGaps(env, localEnv);
1747
1748 code.resolve(falseJumps);
1749 targetEnv = unwindBreak(tree.target);
1750 reloadStackBeforeSwitchExpr();
1751 falseJumps = code.branch(goto_);
1752
1753 if (switchExpressionTrueChain == null) {
1754 switchExpressionTrueChain = trueJumps;
1755 } else {
1756 switchExpressionTrueChain =
1757 Code.mergeChains(switchExpressionTrueChain, trueJumps);
1758 }
1759 if (switchExpressionFalseChain == null) {
1760 switchExpressionFalseChain = falseJumps;
1761 } else {
1762 switchExpressionFalseChain =
1763 Code.mergeChains(switchExpressionFalseChain, falseJumps);
1764 }
1765 } else {
1766 genExpr(tree.value, pt).load();
1767 if (switchResult != null)
1768 switchResult.store();
1769
1770 targetEnv = unwindBreak(tree.target);
1771
1772 if (code.isAlive()) {
1773 reloadStackBeforeSwitchExpr();
1774 if (switchResult != null)
1775 switchResult.load();
1776
1777 code.state.forceStackTop(tree.target.type);
1778 targetEnv.info.addExit(code.branch(goto_));
1779 code.markDead();
1780 }
1781 }
1782 endFinalizerGaps(env, targetEnv);
1783 }
1784 //where:
1785 /** As side-effect, might mark code as dead disabling any further emission.
1786 */
1787 private Env<GenContext> unwindBreak(JCTree target) {
1788 int tmpPos = code.pendingStatPos;
1789 Env<GenContext> targetEnv = unwind(target, env);
1790 code.pendingStatPos = tmpPos;
1791 return targetEnv;
1792 }
1793
1794 private void reloadStackBeforeSwitchExpr() {
1795 for (LocalItem li : stackBeforeSwitchExpression)
1796 li.load();
1797 }
1798
1799 public void visitContinue(JCContinue tree) {
1800 int tmpPos = code.pendingStatPos;
1801 Env<GenContext> targetEnv = unwind(tree.target, env);
1802 code.pendingStatPos = tmpPos;
1803 Assert.check(code.isStatementStart());
1804 targetEnv.info.addCont(code.branch(goto_));
1805 endFinalizerGaps(env, targetEnv);
1806 }
1807
1808 public void visitReturn(JCReturn tree) {
1809 int limit = code.nextreg;
1810 final Env<GenContext> targetEnv;
1811
1812 /* Save and then restore the location of the return in case a finally
1813 * is expanded (with unwind()) in the middle of our bytecodes.
1814 */
1815 int tmpPos = code.pendingStatPos;
1816 if (tree.expr != null) {
1817 Assert.check(code.isStatementStart());
1818 Item r = genExpr(tree.expr, pt).load();
1819 if (hasFinally(env.enclMethod, env)) {
1820 r = makeTemp(pt);
1821 r.store();
1822 }
1823 targetEnv = unwind(env.enclMethod, env);
1824 code.pendingStatPos = tmpPos;
1825 r.load();
1826 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
1827 } else {
1828 targetEnv = unwind(env.enclMethod, env);
1829 code.pendingStatPos = tmpPos;
1830 code.emitop0(return_);
1831 }
1832 endFinalizerGaps(env, targetEnv);
1833 code.endScopes(limit);
1834 }
1835
1836 public void visitThrow(JCThrow tree) {
1837 Assert.check(code.isStatementStart());
1838 genExpr(tree.expr, tree.expr.type).load();
1839 code.emitop0(athrow);
1840 Assert.check(code.isStatementStart());
1841 }
1842
1843 /* ************************************************************************
1844 * Visitor methods for expressions
1845 *************************************************************************/
1846
1847 public void visitApply(JCMethodInvocation tree) {
1848 setTypeAnnotationPositions(tree.pos);
1849 // Generate code for method.
1850 Item m = genExpr(tree.meth, methodType);
1851 // Generate code for all arguments, where the expected types are
1852 // the parameters of the method's external type (that is, any implicit
1853 // outer instance of a super(...) call appears as first parameter).
1854 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(tree.meth);
1855 genArgs(tree.args,
1856 msym.externalType(types).getParameterTypes());
1857 if (!msym.isDynamic()) {
1858 code.statBegin(tree.pos);
1859 }
1860 result = m.invoke();
1861 }
1862
1863 public void visitConditional(JCConditional tree) {
1864 Chain thenExit = null;
1865 code.statBegin(tree.cond.pos);
1866 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
1867 Chain elseChain = c.jumpFalse();
1868 if (!c.isFalse()) {
1869 code.resolve(c.trueJumps);
1870 int startpc = genCrt ? code.curCP() : 0;
1871 code.statBegin(tree.truepart.pos);
1872 genExpr(tree.truepart, pt).load();
1873 code.state.forceStackTop(tree.type);
1874 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
1875 startpc, code.curCP());
1876 thenExit = code.branch(goto_);
1877 }
1878 if (elseChain != null) {
1879 code.resolve(elseChain);
1880 int startpc = genCrt ? code.curCP() : 0;
1881 code.statBegin(tree.falsepart.pos);
1882 genExpr(tree.falsepart, pt).load();
1883 code.state.forceStackTop(tree.type);
1884 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
1885 startpc, code.curCP());
1886 }
1887 code.resolve(thenExit);
1888 result = items.makeStackItem(pt);
1889 }
1890
1891 private void setTypeAnnotationPositions(int treePos) {
1892 MethodSymbol meth = code.meth;
1893 boolean initOrClinit = code.meth.getKind() == javax.lang.model.element.ElementKind.CONSTRUCTOR
1894 || code.meth.getKind() == javax.lang.model.element.ElementKind.STATIC_INIT;
1895
1896 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
1897 if (ta.hasUnknownPosition())
1898 ta.tryFixPosition();
1899
1900 if (ta.position.matchesPos(treePos))
1901 ta.position.updatePosOffset(code.cp);
1902 }
1903
1904 if (!initOrClinit)
1905 return;
1906
1907 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
1908 if (ta.hasUnknownPosition())
1909 ta.tryFixPosition();
1910
1911 if (ta.position.matchesPos(treePos))
1912 ta.position.updatePosOffset(code.cp);
1913 }
1914
1915 ClassSymbol clazz = meth.enclClass();
1916 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
1917 if (!s.getKind().isField())
1918 continue;
1919
1920 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
1921 if (ta.hasUnknownPosition())
1922 ta.tryFixPosition();
1923
1924 if (ta.position.matchesPos(treePos))
1925 ta.position.updatePosOffset(code.cp);
1926 }
1927 }
1928 }
1929
1930 public void visitNewClass(JCNewClass tree) {
1931 // Enclosing instances or anonymous classes should have been eliminated
1932 // by now.
1933 Assert.check(tree.encl == null && tree.def == null);
1934 setTypeAnnotationPositions(tree.pos);
1935
1936 code.emitop2(new_, checkDimension(tree.pos(), tree.type), PoolWriter::putClass);
1937 code.emitop0(dup);
1938
1939 // Generate code for all arguments, where the expected types are
1940 // the parameters of the constructor's external type (that is,
1941 // any implicit outer instance appears as first parameter).
1942 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
1943
1944 items.makeMemberItem(tree.constructor, true).invoke();
1945 result = items.makeStackItem(tree.type);
1946 }
1947
1948 public void visitNewArray(JCNewArray tree) {
1949 setTypeAnnotationPositions(tree.pos);
1950
1951 if (tree.elems != null) {
1952 Type elemtype = types.elemtype(tree.type);
1953 loadIntConst(tree.elems.length());
1954 Item arr = makeNewArray(tree.pos(), tree.type, 1);
1955 int i = 0;
1956 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
1957 arr.duplicate();
1958 loadIntConst(i);
1959 i++;
1960 genExpr(l.head, elemtype).load();
1961 items.makeIndexedItem(elemtype).store();
1962 }
1963 result = arr;
1964 } else {
1965 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1966 genExpr(l.head, syms.intType).load();
1967 }
1968 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
1969 }
1970 }
1971 //where
1972 /** Generate code to create an array with given element type and number
1973 * of dimensions.
1974 */
1975 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
1976 Type elemtype = types.elemtype(type);
1977 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
1978 log.error(pos, Errors.LimitDimensions);
1979 nerrs++;
1980 }
1981 int elemcode = Code.arraycode(elemtype);
1982 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
1983 code.emitAnewarray(makeRef(pos, elemtype), type);
1984 } else if (elemcode == 1) {
1985 code.emitMultianewarray(ndims, makeRef(pos, type), type);
1986 } else {
1987 code.emitNewarray(elemcode, type);
1988 }
1989 return items.makeStackItem(type);
1990 }
1991
1992 public void visitParens(JCParens tree) {
1993 result = genExpr(tree.expr, tree.expr.type);
1994 }
1995
1996 public void visitAssign(JCAssign tree) {
1997 Item l = genExpr(tree.lhs, tree.lhs.type);
1998 genExpr(tree.rhs, tree.lhs.type).load();
1999 if (tree.rhs.type.hasTag(BOT)) {
2000 /* This is just a case of widening reference conversion that per 5.1.5 simply calls
2001 for "regarding a reference as having some other type in a manner that can be proved
2002 correct at compile time."
2003 */
2004 code.state.forceStackTop(tree.lhs.type);
2005 }
2006 result = items.makeAssignItem(l);
2007 }
2008
2009 public void visitAssignop(JCAssignOp tree) {
2010 OperatorSymbol operator = tree.operator;
2011 Item l;
2012 if (operator.opcode == string_add) {
2013 l = concat.makeConcat(tree);
2014 } else {
2015 // Generate code for first expression
2016 l = genExpr(tree.lhs, tree.lhs.type);
2017
2018 // If we have an increment of -32768 to +32767 of a local
2019 // int variable we can use an incr instruction instead of
2020 // proceeding further.
2021 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
2022 l instanceof LocalItem &&
2023 tree.lhs.type.getTag().isSubRangeOf(INT) &&
2024 tree.rhs.type.getTag().isSubRangeOf(INT) &&
2025 tree.rhs.type.constValue() != null) {
2026 int ival = ((Number) tree.rhs.type.constValue()).intValue();
2027 if (tree.hasTag(MINUS_ASG)) ival = -ival;
2028 ((LocalItem)l).incr(ival);
2029 result = l;
2030 return;
2031 }
2032 // Otherwise, duplicate expression, load one copy
2033 // and complete binary operation.
2034 l.duplicate();
2035 l.coerce(operator.type.getParameterTypes().head).load();
2036 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
2037 }
2038 result = items.makeAssignItem(l);
2039 }
2040
2041 public void visitUnary(JCUnary tree) {
2042 OperatorSymbol operator = tree.operator;
2043 if (tree.hasTag(NOT)) {
2044 CondItem od = genCond(tree.arg, false);
2045 result = od.negate();
2046 } else {
2047 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
2048 switch (tree.getTag()) {
2049 case POS:
2050 result = od.load();
2051 break;
2052 case NEG:
2053 result = od.load();
2054 code.emitop0(operator.opcode);
2055 break;
2056 case COMPL:
2057 result = od.load();
2058 emitMinusOne(od.typecode);
2059 code.emitop0(operator.opcode);
2060 break;
2061 case PREINC: case PREDEC:
2062 od.duplicate();
2063 if (od instanceof LocalItem &&
2064 (operator.opcode == iadd || operator.opcode == isub)) {
2065 ((LocalItem)od).incr(tree.hasTag(PREINC) ? 1 : -1);
2066 result = od;
2067 } else {
2068 od.load();
2069 code.emitop0(one(od.typecode));
2070 code.emitop0(operator.opcode);
2071 // Perform narrowing primitive conversion if byte,
2072 // char, or short. Fix for 4304655.
2073 if (od.typecode != INTcode &&
2074 Code.truncate(od.typecode) == INTcode)
2075 code.emitop0(int2byte + od.typecode - BYTEcode);
2076 result = items.makeAssignItem(od);
2077 }
2078 break;
2079 case POSTINC: case POSTDEC:
2080 od.duplicate();
2081 if (od instanceof LocalItem &&
2082 (operator.opcode == iadd || operator.opcode == isub)) {
2083 Item res = od.load();
2084 ((LocalItem)od).incr(tree.hasTag(POSTINC) ? 1 : -1);
2085 result = res;
2086 } else {
2087 Item res = od.load();
2088 od.stash(od.typecode);
2089 code.emitop0(one(od.typecode));
2090 code.emitop0(operator.opcode);
2091 // Perform narrowing primitive conversion if byte,
2092 // char, or short. Fix for 4304655.
2093 if (od.typecode != INTcode &&
2094 Code.truncate(od.typecode) == INTcode)
2095 code.emitop0(int2byte + od.typecode - BYTEcode);
2096 od.store();
2097 result = res;
2098 }
2099 break;
2100 case NULLCHK:
2101 result = od.load();
2102 code.emitop0(dup);
2103 genNullCheck(tree);
2104 break;
2105 default:
2106 Assert.error();
2107 }
2108 }
2109 }
2110
2111 /** Generate a null check from the object value at stack top. */
2112 private void genNullCheck(JCTree tree) {
2113 code.statBegin(tree.pos);
2114 callMethod(tree.pos(), syms.objectsType, names.requireNonNull,
2115 List.of(syms.objectType), true);
2116 code.emitop0(pop);
2117 }
2118
2119 public void visitBinary(JCBinary tree) {
2120 OperatorSymbol operator = tree.operator;
2121 if (operator.opcode == string_add) {
2122 result = concat.makeConcat(tree);
2123 } else if (tree.hasTag(AND)) {
2124 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2125 if (!lcond.isFalse()) {
2126 Chain falseJumps = lcond.jumpFalse();
2127 code.resolve(lcond.trueJumps);
2128 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2129 result = items.
2130 makeCondItem(rcond.opcode,
2131 rcond.trueJumps,
2132 Code.mergeChains(falseJumps,
2133 rcond.falseJumps));
2134 } else {
2135 result = lcond;
2136 }
2137 } else if (tree.hasTag(OR)) {
2138 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2139 if (!lcond.isTrue()) {
2140 Chain trueJumps = lcond.jumpTrue();
2141 code.resolve(lcond.falseJumps);
2142 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2143 result = items.
2144 makeCondItem(rcond.opcode,
2145 Code.mergeChains(trueJumps, rcond.trueJumps),
2146 rcond.falseJumps);
2147 } else {
2148 result = lcond;
2149 }
2150 } else {
2151 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
2152 od.load();
2153 result = completeBinop(tree.lhs, tree.rhs, operator);
2154 }
2155 }
2156
2157
2158 /** Complete generating code for operation, with left operand
2159 * already on stack.
2160 * @param lhs The tree representing the left operand.
2161 * @param rhs The tree representing the right operand.
2162 * @param operator The operator symbol.
2163 */
2164 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2165 MethodType optype = (MethodType)operator.type;
2166 int opcode = operator.opcode;
2167 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2168 rhs.type.constValue() instanceof Number &&
2169 ((Number) rhs.type.constValue()).intValue() == 0) {
2170 opcode = opcode + (ifeq - if_icmpeq);
2171 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2172 TreeInfo.isNull(rhs)) {
2173 opcode = opcode + (if_acmp_null - if_acmpeq);
2174 } else {
2175 // The expected type of the right operand is
2176 // the second parameter type of the operator, except for
2177 // shifts with long shiftcount, where we convert the opcode
2178 // to a short shift and the expected type to int.
2179 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2180 if (opcode >= ishll && opcode <= lushrl) {
2181 opcode = opcode + (ishl - ishll);
2182 rtype = syms.intType;
2183 }
2184 // Generate code for right operand and load.
2185 genExpr(rhs, rtype).load();
2186 // If there are two consecutive opcode instructions,
2187 // emit the first now.
2188 if (opcode >= (1 << preShift)) {
2189 code.emitop0(opcode >> preShift);
2190 opcode = opcode & 0xFF;
2191 }
2192 }
2193 if (opcode >= ifeq && opcode <= if_acmpne ||
2194 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2195 return items.makeCondItem(opcode);
2196 } else {
2197 code.emitop0(opcode);
2198 return items.makeStackItem(optype.restype);
2199 }
2200 }
2201
2202 public void visitTypeCast(JCTypeCast tree) {
2203 result = genExpr(tree.expr, tree.clazz.type).load();
2204 setTypeAnnotationPositions(tree.pos);
2205 // Additional code is only needed if we cast to a reference type
2206 // which is not statically a supertype of the expression's type.
2207 // For basic types, the coerce(...) in genExpr(...) will do
2208 // the conversion.
2209 if (!tree.clazz.type.isPrimitive() &&
2210 !types.isSameType(tree.expr.type, tree.clazz.type) &&
2211 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2212 code.emitop2(checkcast, checkDimension(tree.pos(), tree.clazz.type), PoolWriter::putClass);
2213 }
2214 }
2215
2216 public void visitWildcard(JCWildcard tree) {
2217 throw new AssertionError(this.getClass().getName());
2218 }
2219
2220 public void visitTypeTest(JCInstanceOf tree) {
2221 genExpr(tree.expr, tree.expr.type).load();
2222 setTypeAnnotationPositions(tree.pos);
2223 code.emitop2(instanceof_, makeRef(tree.pos(), tree.pattern.type));
2224 result = items.makeStackItem(syms.booleanType);
2225 }
2226
2227 public void visitIndexed(JCArrayAccess tree) {
2228 genExpr(tree.indexed, tree.indexed.type).load();
2229 genExpr(tree.index, syms.intType).load();
2230 result = items.makeIndexedItem(tree.type);
2231 }
2232
2233 public void visitIdent(JCIdent tree) {
2234 Symbol sym = tree.sym;
2235 if (tree.name == names._this || tree.name == names._super) {
2236 Item res = tree.name == names._this
2237 ? items.makeThisItem()
2238 : items.makeSuperItem();
2239 if (sym.kind == MTH) {
2240 // Generate code to address the constructor.
2241 res.load();
2242 res = items.makeMemberItem(sym, true);
2243 }
2244 result = res;
2245 } else if (isInvokeDynamic(sym) || isConstantDynamic(sym)) {
2246 if (isConstantDynamic(sym)) {
2247 setTypeAnnotationPositions(tree.pos);
2248 }
2249 result = items.makeDynamicItem(sym);
2250 } else if (sym.kind == VAR && (sym.owner.kind == MTH || sym.owner.kind == VAR)) {
2251 result = items.makeLocalItem((VarSymbol)sym);
2252 } else if ((sym.flags() & STATIC) != 0) {
2253 if (!isAccessSuper(env.enclMethod))
2254 sym = binaryQualifier(sym, env.enclClass.type);
2255 result = items.makeStaticItem(sym);
2256 } else {
2257 items.makeThisItem().load();
2258 sym = binaryQualifier(sym, env.enclClass.type);
2259 result = items.makeMemberItem(sym, nonVirtualForPrivateAccess(sym));
2260 }
2261 }
2262
2263 //where
2264 private boolean nonVirtualForPrivateAccess(Symbol sym) {
2265 boolean useVirtual = target.hasVirtualPrivateInvoke() &&
2266 !disableVirtualizedPrivateInvoke;
2267 return !useVirtual && ((sym.flags() & PRIVATE) != 0);
2268 }
2269
2270 public void visitSelect(JCFieldAccess tree) {
2271 Symbol sym = tree.sym;
2272
2273 if (tree.name == names._class) {
2274 code.emitLdc((LoadableConstant)checkDimension(tree.pos(), tree.selected.type));
2275 result = items.makeStackItem(pt);
2276 return;
2277 }
2278
2279 Symbol ssym = TreeInfo.symbol(tree.selected);
2280
2281 // Are we selecting via super?
2282 boolean selectSuper =
2283 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2284
2285 // Are we accessing a member of the superclass in an access method
2286 // resulting from a qualified super?
2287 boolean accessSuper = isAccessSuper(env.enclMethod);
2288
2289 Item base = (selectSuper)
2290 ? items.makeSuperItem()
2291 : genExpr(tree.selected, tree.selected.type);
2292
2293 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2294 // We are seeing a variable that is constant but its selecting
2295 // expression is not.
2296 if ((sym.flags() & STATIC) != 0) {
2297 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2298 base = base.load();
2299 base.drop();
2300 } else {
2301 base.load();
2302 genNullCheck(tree.selected);
2303 }
2304 result = items.
2305 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2306 } else {
2307 if (isInvokeDynamic(sym)) {
2308 result = items.makeDynamicItem(sym);
2309 return;
2310 } else {
2311 sym = binaryQualifier(sym, tree.selected.type);
2312 }
2313 if ((sym.flags() & STATIC) != 0) {
2314 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2315 base = base.load();
2316 base.drop();
2317 result = items.makeStaticItem(sym);
2318 } else {
2319 base.load();
2320 if (sym == syms.lengthVar) {
2321 code.emitop0(arraylength);
2322 result = items.makeStackItem(syms.intType);
2323 } else {
2324 result = items.
2325 makeMemberItem(sym,
2326 nonVirtualForPrivateAccess(sym) ||
2327 selectSuper || accessSuper);
2328 }
2329 }
2330 }
2331 }
2332
2333 public boolean isInvokeDynamic(Symbol sym) {
2334 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
2335 }
2336
2337 public void visitLiteral(JCLiteral tree) {
2338 if (tree.type.hasTag(BOT)) {
2339 code.emitop0(aconst_null);
2340 result = items.makeStackItem(tree.type);
2341 }
2342 else
2343 result = items.makeImmediateItem(tree.type, tree.value);
2344 }
2345
2346 public void visitLetExpr(LetExpr tree) {
2347 code.resolvePending();
2348
2349 int limit = code.nextreg;
2350 int prevLetExprStart = code.setLetExprStackPos(code.state.stacksize);
2351 try {
2352 genStats(tree.defs, env);
2353 } finally {
2354 code.setLetExprStackPos(prevLetExprStart);
2355 }
2356 result = genExpr(tree.expr, tree.expr.type).load();
2357 code.endScopes(limit);
2358 }
2359
2360 private void generateReferencesToPrunedTree(ClassSymbol classSymbol) {
2361 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
2362 if (prunedInfo != null) {
2363 for (JCTree prunedTree: prunedInfo) {
2364 prunedTree.accept(classReferenceVisitor);
2365 }
2366 }
2367 }
2368
2369 /* ************************************************************************
2370 * main method
2371 *************************************************************************/
2372
2373 /** Generate code for a class definition.
2374 * @param env The attribution environment that belongs to the
2375 * outermost class containing this class definition.
2376 * We need this for resolving some additional symbols.
2377 * @param cdef The tree representing the class definition.
2378 * @return True if code is generated with no errors.
2379 */
2380 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2381 try {
2382 attrEnv = env;
2383 ClassSymbol c = cdef.sym;
2384 this.toplevel = env.toplevel;
2385 this.endPosTable = toplevel.endPositions;
2386 /* method normalizeDefs() can add references to external classes into the constant pool
2387 */
2388 cdef.defs = normalizeDefs(cdef.defs, c);
2389 generateReferencesToPrunedTree(c);
2390 Env<GenContext> localEnv = new Env<>(cdef, new GenContext());
2391 localEnv.toplevel = env.toplevel;
2392 localEnv.enclClass = cdef;
2393
2394 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2395 genDef(l.head, localEnv);
2396 }
2397 if (poolWriter.size() > PoolWriter.MAX_ENTRIES) {
2398 log.error(cdef.pos(), Errors.LimitPool);
2399 nerrs++;
2400 }
2401 if (nerrs != 0) {
2402 // if errors, discard code
2403 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2404 if (l.head.hasTag(METHODDEF))
2405 ((JCMethodDecl) l.head).sym.code = null;
2406 }
2407 }
2408 cdef.defs = List.nil(); // discard trees
2409 return nerrs == 0;
2410 } finally {
2411 // note: this method does NOT support recursion.
2412 attrEnv = null;
2413 this.env = null;
2414 toplevel = null;
2415 endPosTable = null;
2416 nerrs = 0;
2417 }
2418 }
2419
2420 /* ************************************************************************
2421 * Auxiliary classes
2422 *************************************************************************/
2423
2424 /** An abstract class for finalizer generation.
2425 */
2426 abstract class GenFinalizer {
2427 /** Generate code to clean up when unwinding. */
2428 abstract void gen();
2429
2430 /** Generate code to clean up at last. */
2431 abstract void genLast();
2432
2433 /** Does this finalizer have some nontrivial cleanup to perform? */
2434 boolean hasFinalizer() { return true; }
2435
2436 /** Should be invoked after the try's body has been visited. */
2437 void afterBody() {}
2438 }
2439
2440 /** code generation contexts,
2441 * to be used as type parameter for environments.
2442 */
2443 static class GenContext {
2444
2445 /** A chain for all unresolved jumps that exit the current environment.
2446 */
2447 Chain exit = null;
2448
2449 /** A chain for all unresolved jumps that continue in the
2450 * current environment.
2451 */
2452 Chain cont = null;
2453
2454 /** A closure that generates the finalizer of the current environment.
2455 * Only set for Synchronized and Try contexts.
2456 */
2457 GenFinalizer finalize = null;
2458
2459 /** Is this a switch statement? If so, allocate registers
2460 * even when the variable declaration is unreachable.
2461 */
2462 boolean isSwitch = false;
2463
2464 /** A list buffer containing all gaps in the finalizer range,
2465 * where a catch all exception should not apply.
2466 */
2467 ListBuffer<Integer> gaps = null;
2468
2469 /** Add given chain to exit chain.
2470 */
2471 void addExit(Chain c) {
2472 exit = Code.mergeChains(c, exit);
2473 }
2474
2475 /** Add given chain to cont chain.
2476 */
2477 void addCont(Chain c) {
2478 cont = Code.mergeChains(c, cont);
2479 }
2480 }
2481
2482 }