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