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