Mercurial > jdk8-mips64-public > langtools / file revision
src/share/classes/com/sun/tools/javac/jvm/Gen.java@22872b24d38c
src/share/classes/com/sun/tools/javac/jvm/Gen.java
Tue, 16 Jun 2009 10:46:37 +0100
- author
- mcimadamore
- date
- Tue, 16 Jun 2009 10:46:37 +0100
- changeset 299
- 22872b24d38c
- parent 267
- e2722bd43f3a
- child 308
- 03944ee4fac4
- permissions
- -rw-r--r--
6638712: Inference with wildcard types causes selection of inapplicable method
Summary: Added global sanity check in order to make sure that return type inference does not violate bounds constraints
Reviewed-by: jjg
1 /*
2 * Copyright 1999-2008 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
26 package com.sun.tools.javac.jvm;
27 import java.util.*;
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.comp.*;
34 import com.sun.tools.javac.tree.*;
36 import com.sun.tools.javac.code.Symbol.*;
37 import com.sun.tools.javac.code.Type.*;
38 import com.sun.tools.javac.jvm.Code.*;
39 import com.sun.tools.javac.jvm.Items.*;
40 import com.sun.tools.javac.tree.JCTree.*;
42 import static com.sun.tools.javac.code.Flags.*;
43 import static com.sun.tools.javac.code.Kinds.*;
44 import static com.sun.tools.javac.code.TypeTags.*;
45 import static com.sun.tools.javac.jvm.ByteCodes.*;
46 import static com.sun.tools.javac.jvm.CRTFlags.*;
48 /** This pass maps flat Java (i.e. without inner classes) to bytecodes.
49 *
50 * <p><b>This is NOT part of any API supported by Sun Microsystems. If
51 * you write code that depends on this, you do so at your own risk.
52 * This code and its internal interfaces are subject to change or
53 * deletion without notice.</b>
54 */
55 public class Gen extends JCTree.Visitor {
56 protected static final Context.Key<Gen> genKey =
57 new Context.Key<Gen>();
59 private final Log log;
60 private final Symtab syms;
61 private final Check chk;
62 private final Resolve rs;
63 private final TreeMaker make;
64 private final Names names;
65 private final Target target;
66 private final Type stringBufferType;
67 private final Map<Type,Symbol> stringBufferAppend;
68 private Name accessDollar;
69 private final Types types;
71 /** Switch: GJ mode?
72 */
73 private final boolean allowGenerics;
75 /** Set when Miranda method stubs are to be generated. */
76 private final boolean generateIproxies;
78 /** Format of stackmap tables to be generated. */
79 private final Code.StackMapFormat stackMap;
81 /** A type that serves as the expected type for all method expressions.
82 */
83 private final Type methodType;
85 public static Gen instance(Context context) {
86 Gen instance = context.get(genKey);
87 if (instance == null)
88 instance = new Gen(context);
89 return instance;
90 }
92 protected Gen(Context context) {
93 context.put(genKey, this);
95 names = Names.instance(context);
96 log = Log.instance(context);
97 syms = Symtab.instance(context);
98 chk = Check.instance(context);
99 rs = Resolve.instance(context);
100 make = TreeMaker.instance(context);
101 target = Target.instance(context);
102 types = Types.instance(context);
103 methodType = new MethodType(null, null, null, syms.methodClass);
104 allowGenerics = Source.instance(context).allowGenerics();
105 stringBufferType = target.useStringBuilder()
106 ? syms.stringBuilderType
107 : syms.stringBufferType;
108 stringBufferAppend = new HashMap<Type,Symbol>();
109 accessDollar = names.
110 fromString("access" + target.syntheticNameChar());
112 Options options = Options.instance(context);
113 lineDebugInfo =
114 options.get("-g:") == null ||
115 options.get("-g:lines") != null;
116 varDebugInfo =
117 options.get("-g:") == null
118 ? options.get("-g") != null
119 : options.get("-g:vars") != null;
120 genCrt = options.get("-Xjcov") != null;
121 debugCode = options.get("debugcode") != null;
122 allowInvokedynamic = options.get("invokedynamic") != null;
124 generateIproxies =
125 target.requiresIproxy() ||
126 options.get("miranda") != null;
128 if (target.generateStackMapTable()) {
129 // ignore cldc because we cannot have both stackmap formats
130 this.stackMap = StackMapFormat.JSR202;
131 } else {
132 if (target.generateCLDCStackmap()) {
133 this.stackMap = StackMapFormat.CLDC;
134 } else {
135 this.stackMap = StackMapFormat.NONE;
136 }
137 }
139 // by default, avoid jsr's for simple finalizers
140 int setjsrlimit = 50;
141 String jsrlimitString = options.get("jsrlimit");
142 if (jsrlimitString != null) {
143 try {
144 setjsrlimit = Integer.parseInt(jsrlimitString);
145 } catch (NumberFormatException ex) {
146 // ignore ill-formed numbers for jsrlimit
147 }
148 }
149 this.jsrlimit = setjsrlimit;
150 this.useJsrLocally = false; // reset in visitTry
151 }
153 /** Switches
154 */
155 private final boolean lineDebugInfo;
156 private final boolean varDebugInfo;
157 private final boolean genCrt;
158 private final boolean debugCode;
159 private final boolean allowInvokedynamic;
161 /** Default limit of (approximate) size of finalizer to inline.
162 * Zero means always use jsr. 100 or greater means never use
163 * jsr.
164 */
165 private final int jsrlimit;
167 /** True if jsr is used.
168 */
169 private boolean useJsrLocally;
171 /* Constant pool, reset by genClass.
172 */
173 private Pool pool = new Pool();
175 /** Code buffer, set by genMethod.
176 */
177 private Code code;
179 /** Items structure, set by genMethod.
180 */
181 private Items items;
183 /** Environment for symbol lookup, set by genClass
184 */
185 private Env<AttrContext> attrEnv;
187 /** The top level tree.
188 */
189 private JCCompilationUnit toplevel;
191 /** The number of code-gen errors in this class.
192 */
193 private int nerrs = 0;
195 /** A hash table mapping syntax trees to their ending source positions.
196 */
197 private Map<JCTree, Integer> endPositions;
199 /** Generate code to load an integer constant.
200 * @param n The integer to be loaded.
201 */
202 void loadIntConst(int n) {
203 items.makeImmediateItem(syms.intType, n).load();
204 }
206 /** The opcode that loads a zero constant of a given type code.
207 * @param tc The given type code (@see ByteCode).
208 */
209 public static int zero(int tc) {
210 switch(tc) {
211 case INTcode: case BYTEcode: case SHORTcode: case CHARcode:
212 return iconst_0;
213 case LONGcode:
214 return lconst_0;
215 case FLOATcode:
216 return fconst_0;
217 case DOUBLEcode:
218 return dconst_0;
219 default:
220 throw new AssertionError("zero");
221 }
222 }
224 /** The opcode that loads a one constant of a given type code.
225 * @param tc The given type code (@see ByteCode).
226 */
227 public static int one(int tc) {
228 return zero(tc) + 1;
229 }
231 /** Generate code to load -1 of the given type code (either int or long).
232 * @param tc The given type code (@see ByteCode).
233 */
234 void emitMinusOne(int tc) {
235 if (tc == LONGcode) {
236 items.makeImmediateItem(syms.longType, new Long(-1)).load();
237 } else {
238 code.emitop0(iconst_m1);
239 }
240 }
242 /** Construct a symbol to reflect the qualifying type that should
243 * appear in the byte code as per JLS 13.1.
244 *
245 * For target >= 1.2: Clone a method with the qualifier as owner (except
246 * for those cases where we need to work around VM bugs).
247 *
248 * For target <= 1.1: If qualified variable or method is defined in a
249 * non-accessible class, clone it with the qualifier class as owner.
250 *
251 * @param sym The accessed symbol
252 * @param site The qualifier's type.
253 */
254 Symbol binaryQualifier(Symbol sym, Type site) {
256 if (site.tag == ARRAY) {
257 if (sym == syms.lengthVar ||
258 sym.owner != syms.arrayClass)
259 return sym;
260 // array clone can be qualified by the array type in later targets
261 Symbol qualifier = target.arrayBinaryCompatibility()
262 ? new ClassSymbol(Flags.PUBLIC, site.tsym.name,
263 site, syms.noSymbol)
264 : syms.objectType.tsym;
265 return sym.clone(qualifier);
266 }
268 if (sym.owner == site.tsym ||
269 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) {
270 return sym;
271 }
272 if (!target.obeyBinaryCompatibility())
273 return rs.isAccessible(attrEnv, (TypeSymbol)sym.owner)
274 ? sym
275 : sym.clone(site.tsym);
277 if (!target.interfaceFieldsBinaryCompatibility()) {
278 if ((sym.owner.flags() & INTERFACE) != 0 && sym.kind == VAR)
279 return sym;
280 }
282 // leave alone methods inherited from Object
283 // JLS2 13.1.
284 if (sym.owner == syms.objectType.tsym)
285 return sym;
287 if (!target.interfaceObjectOverridesBinaryCompatibility()) {
288 if ((sym.owner.flags() & INTERFACE) != 0 &&
289 syms.objectType.tsym.members().lookup(sym.name).scope != null)
290 return sym;
291 }
293 return sym.clone(site.tsym);
294 }
296 /** Insert a reference to given type in the constant pool,
297 * checking for an array with too many dimensions;
298 * return the reference's index.
299 * @param type The type for which a reference is inserted.
300 */
301 int makeRef(DiagnosticPosition pos, Type type) {
302 checkDimension(pos, type);
303 return pool.put(type.tag == CLASS ? (Object)type.tsym : (Object)type);
304 }
306 /** Check if the given type is an array with too many dimensions.
307 */
308 private void checkDimension(DiagnosticPosition pos, Type t) {
309 switch (t.tag) {
310 case METHOD:
311 checkDimension(pos, t.getReturnType());
312 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail)
313 checkDimension(pos, args.head);
314 break;
315 case ARRAY:
316 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) {
317 log.error(pos, "limit.dimensions");
318 nerrs++;
319 }
320 break;
321 default:
322 break;
323 }
324 }
326 /** Create a tempory variable.
327 * @param type The variable's type.
328 */
329 LocalItem makeTemp(Type type) {
330 VarSymbol v = new VarSymbol(Flags.SYNTHETIC,
331 names.empty,
332 type,
333 env.enclMethod.sym);
334 code.newLocal(v);
335 return items.makeLocalItem(v);
336 }
338 /** Generate code to call a non-private method or constructor.
339 * @param pos Position to be used for error reporting.
340 * @param site The type of which the method is a member.
341 * @param name The method's name.
342 * @param argtypes The method's argument types.
343 * @param isStatic A flag that indicates whether we call a
344 * static or instance method.
345 */
346 void callMethod(DiagnosticPosition pos,
347 Type site, Name name, List<Type> argtypes,
348 boolean isStatic) {
349 Symbol msym = rs.
350 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null);
351 if (isStatic) items.makeStaticItem(msym).invoke();
352 else items.makeMemberItem(msym, name == names.init).invoke();
353 }
355 /** Is the given method definition an access method
356 * resulting from a qualified super? This is signified by an odd
357 * access code.
358 */
359 private boolean isAccessSuper(JCMethodDecl enclMethod) {
360 return
361 (enclMethod.mods.flags & SYNTHETIC) != 0 &&
362 isOddAccessName(enclMethod.name);
363 }
365 /** Does given name start with "access$" and end in an odd digit?
366 */
367 private boolean isOddAccessName(Name name) {
368 return
369 name.startsWith(accessDollar) &&
370 (name.getByteAt(name.getByteLength() - 1) & 1) == 1;
371 }
373 /* ************************************************************************
374 * Non-local exits
375 *************************************************************************/
377 /** Generate code to invoke the finalizer associated with given
378 * environment.
379 * Any calls to finalizers are appended to the environments `cont' chain.
380 * Mark beginning of gap in catch all range for finalizer.
381 */
382 void genFinalizer(Env<GenContext> env) {
383 if (code.isAlive() && env.info.finalize != null)
384 env.info.finalize.gen();
385 }
387 /** Generate code to call all finalizers of structures aborted by
388 * a non-local
389 * exit. Return target environment of the non-local exit.
390 * @param target The tree representing the structure that's aborted
391 * @param env The environment current at the non-local exit.
392 */
393 Env<GenContext> unwind(JCTree target, Env<GenContext> env) {
394 Env<GenContext> env1 = env;
395 while (true) {
396 genFinalizer(env1);
397 if (env1.tree == target) break;
398 env1 = env1.next;
399 }
400 return env1;
401 }
403 /** Mark end of gap in catch-all range for finalizer.
404 * @param env the environment which might contain the finalizer
405 * (if it does, env.info.gaps != null).
406 */
407 void endFinalizerGap(Env<GenContext> env) {
408 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1)
409 env.info.gaps.append(code.curPc());
410 }
412 /** Mark end of all gaps in catch-all ranges for finalizers of environments
413 * lying between, and including to two environments.
414 * @param from the most deeply nested environment to mark
415 * @param to the least deeply nested environment to mark
416 */
417 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) {
418 Env<GenContext> last = null;
419 while (last != to) {
420 endFinalizerGap(from);
421 last = from;
422 from = from.next;
423 }
424 }
426 /** Do any of the structures aborted by a non-local exit have
427 * finalizers that require an empty stack?
428 * @param target The tree representing the structure that's aborted
429 * @param env The environment current at the non-local exit.
430 */
431 boolean hasFinally(JCTree target, Env<GenContext> env) {
432 while (env.tree != target) {
433 if (env.tree.getTag() == JCTree.TRY && env.info.finalize.hasFinalizer())
434 return true;
435 env = env.next;
436 }
437 return false;
438 }
440 /* ************************************************************************
441 * Normalizing class-members.
442 *************************************************************************/
444 /** Distribute member initializer code into constructors and <clinit>
445 * method.
446 * @param defs The list of class member declarations.
447 * @param c The enclosing class.
448 */
449 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) {
450 ListBuffer<JCStatement> initCode = new ListBuffer<JCStatement>();
451 ListBuffer<JCStatement> clinitCode = new ListBuffer<JCStatement>();
452 ListBuffer<JCTree> methodDefs = new ListBuffer<JCTree>();
453 // Sort definitions into three listbuffers:
454 // - initCode for instance initializers
455 // - clinitCode for class initializers
456 // - methodDefs for method definitions
457 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
458 JCTree def = l.head;
459 switch (def.getTag()) {
460 case JCTree.BLOCK:
461 JCBlock block = (JCBlock)def;
462 if ((block.flags & STATIC) != 0)
463 clinitCode.append(block);
464 else
465 initCode.append(block);
466 break;
467 case JCTree.METHODDEF:
468 methodDefs.append(def);
469 break;
470 case JCTree.VARDEF:
471 JCVariableDecl vdef = (JCVariableDecl) def;
472 VarSymbol sym = vdef.sym;
473 checkDimension(vdef.pos(), sym.type);
474 if (vdef.init != null) {
475 if ((sym.flags() & STATIC) == 0) {
476 // Always initialize instance variables.
477 JCStatement init = make.at(vdef.pos()).
478 Assignment(sym, vdef.init);
479 initCode.append(init);
480 if (endPositions != null) {
481 Integer endPos = endPositions.remove(vdef);
482 if (endPos != null) endPositions.put(init, endPos);
483 }
484 } else if (sym.getConstValue() == null) {
485 // Initialize class (static) variables only if
486 // they are not compile-time constants.
487 JCStatement init = make.at(vdef.pos).
488 Assignment(sym, vdef.init);
489 clinitCode.append(init);
490 if (endPositions != null) {
491 Integer endPos = endPositions.remove(vdef);
492 if (endPos != null) endPositions.put(init, endPos);
493 }
494 } else {
495 checkStringConstant(vdef.init.pos(), sym.getConstValue());
496 }
497 }
498 break;
499 default:
500 assert false;
501 }
502 }
503 // Insert any instance initializers into all constructors.
504 if (initCode.length() != 0) {
505 List<JCStatement> inits = initCode.toList();
506 for (JCTree t : methodDefs) {
507 normalizeMethod((JCMethodDecl)t, inits);
508 }
509 }
510 // If there are class initializers, create a <clinit> method
511 // that contains them as its body.
512 if (clinitCode.length() != 0) {
513 MethodSymbol clinit = new MethodSymbol(
514 STATIC, names.clinit,
515 new MethodType(
516 List.<Type>nil(), syms.voidType,
517 List.<Type>nil(), syms.methodClass),
518 c);
519 c.members().enter(clinit);
520 List<JCStatement> clinitStats = clinitCode.toList();
521 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
522 block.endpos = TreeInfo.endPos(clinitStats.last());
523 methodDefs.append(make.MethodDef(clinit, block));
524 }
525 // Return all method definitions.
526 return methodDefs.toList();
527 }
529 /** Check a constant value and report if it is a string that is
530 * too large.
531 */
532 private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
533 if (nerrs != 0 || // only complain about a long string once
534 constValue == null ||
535 !(constValue instanceof String) ||
536 ((String)constValue).length() < Pool.MAX_STRING_LENGTH)
537 return;
538 log.error(pos, "limit.string");
539 nerrs++;
540 }
542 /** Insert instance initializer code into initial constructor.
543 * @param md The tree potentially representing a
544 * constructor's definition.
545 * @param initCode The list of instance initializer statements.
546 */
547 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode) {
548 if (md.name == names.init && TreeInfo.isInitialConstructor(md)) {
549 // We are seeing a constructor that does not call another
550 // constructor of the same class.
551 List<JCStatement> stats = md.body.stats;
552 ListBuffer<JCStatement> newstats = new ListBuffer<JCStatement>();
554 if (stats.nonEmpty()) {
555 // Copy initializers of synthetic variables generated in
556 // the translation of inner classes.
557 while (TreeInfo.isSyntheticInit(stats.head)) {
558 newstats.append(stats.head);
559 stats = stats.tail;
560 }
561 // Copy superclass constructor call
562 newstats.append(stats.head);
563 stats = stats.tail;
564 // Copy remaining synthetic initializers.
565 while (stats.nonEmpty() &&
566 TreeInfo.isSyntheticInit(stats.head)) {
567 newstats.append(stats.head);
568 stats = stats.tail;
569 }
570 // Now insert the initializer code.
571 newstats.appendList(initCode);
572 // And copy all remaining statements.
573 while (stats.nonEmpty()) {
574 newstats.append(stats.head);
575 stats = stats.tail;
576 }
577 }
578 md.body.stats = newstats.toList();
579 if (md.body.endpos == Position.NOPOS)
580 md.body.endpos = TreeInfo.endPos(md.body.stats.last());
581 }
582 }
584 /* ********************************************************************
585 * Adding miranda methods
586 *********************************************************************/
588 /** Add abstract methods for all methods defined in one of
589 * the interfaces of a given class,
590 * provided they are not already implemented in the class.
591 *
592 * @param c The class whose interfaces are searched for methods
593 * for which Miranda methods should be added.
594 */
595 void implementInterfaceMethods(ClassSymbol c) {
596 implementInterfaceMethods(c, c);
597 }
599 /** Add abstract methods for all methods defined in one of
600 * the interfaces of a given class,
601 * provided they are not already implemented in the class.
602 *
603 * @param c The class whose interfaces are searched for methods
604 * for which Miranda methods should be added.
605 * @param site The class in which a definition may be needed.
606 */
607 void implementInterfaceMethods(ClassSymbol c, ClassSymbol site) {
608 for (List<Type> l = types.interfaces(c.type); l.nonEmpty(); l = l.tail) {
609 ClassSymbol i = (ClassSymbol)l.head.tsym;
610 for (Scope.Entry e = i.members().elems;
611 e != null;
612 e = e.sibling)
613 {
614 if (e.sym.kind == MTH && (e.sym.flags() & STATIC) == 0)
615 {
616 MethodSymbol absMeth = (MethodSymbol)e.sym;
617 MethodSymbol implMeth = absMeth.binaryImplementation(site, types);
618 if (implMeth == null)
619 addAbstractMethod(site, absMeth);
620 else if ((implMeth.flags() & IPROXY) != 0)
621 adjustAbstractMethod(site, implMeth, absMeth);
622 }
623 }
624 implementInterfaceMethods(i, site);
625 }
626 }
628 /** Add an abstract methods to a class
629 * which implicitly implements a method defined in some interface
630 * implemented by the class. These methods are called "Miranda methods".
631 * Enter the newly created method into its enclosing class scope.
632 * Note that it is not entered into the class tree, as the emitter
633 * doesn't need to see it there to emit an abstract method.
634 *
635 * @param c The class to which the Miranda method is added.
636 * @param m The interface method symbol for which a Miranda method
637 * is added.
638 */
639 private void addAbstractMethod(ClassSymbol c,
640 MethodSymbol m) {
641 MethodSymbol absMeth = new MethodSymbol(
642 m.flags() | IPROXY | SYNTHETIC, m.name,
643 m.type, // was c.type.memberType(m), but now only !generics supported
644 c);
645 c.members().enter(absMeth); // add to symbol table
646 }
648 private void adjustAbstractMethod(ClassSymbol c,
649 MethodSymbol pm,
650 MethodSymbol im) {
651 MethodType pmt = (MethodType)pm.type;
652 Type imt = types.memberType(c.type, im);
653 pmt.thrown = chk.intersect(pmt.getThrownTypes(), imt.getThrownTypes());
654 }
656 /* ************************************************************************
657 * Traversal methods
658 *************************************************************************/
660 /** Visitor argument: The current environment.
661 */
662 Env<GenContext> env;
664 /** Visitor argument: The expected type (prototype).
665 */
666 Type pt;
668 /** Visitor result: The item representing the computed value.
669 */
670 Item result;
672 /** Visitor method: generate code for a definition, catching and reporting
673 * any completion failures.
674 * @param tree The definition to be visited.
675 * @param env The environment current at the definition.
676 */
677 public void genDef(JCTree tree, Env<GenContext> env) {
678 Env<GenContext> prevEnv = this.env;
679 try {
680 this.env = env;
681 tree.accept(this);
682 } catch (CompletionFailure ex) {
683 chk.completionError(tree.pos(), ex);
684 } finally {
685 this.env = prevEnv;
686 }
687 }
689 /** Derived visitor method: check whether CharacterRangeTable
690 * should be emitted, if so, put a new entry into CRTable
691 * and call method to generate bytecode.
692 * If not, just call method to generate bytecode.
693 * @see #genStat(Tree, Env)
694 *
695 * @param tree The tree to be visited.
696 * @param env The environment to use.
697 * @param crtFlags The CharacterRangeTable flags
698 * indicating type of the entry.
699 */
700 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
701 if (!genCrt) {
702 genStat(tree, env);
703 return;
704 }
705 int startpc = code.curPc();
706 genStat(tree, env);
707 if (tree.getTag() == JCTree.BLOCK) crtFlags |= CRT_BLOCK;
708 code.crt.put(tree, crtFlags, startpc, code.curPc());
709 }
711 /** Derived visitor method: generate code for a statement.
712 */
713 public void genStat(JCTree tree, Env<GenContext> env) {
714 if (code.isAlive()) {
715 code.statBegin(tree.pos);
716 genDef(tree, env);
717 } else if (env.info.isSwitch && tree.getTag() == JCTree.VARDEF) {
718 // variables whose declarations are in a switch
719 // can be used even if the decl is unreachable.
720 code.newLocal(((JCVariableDecl) tree).sym);
721 }
722 }
724 /** Derived visitor method: check whether CharacterRangeTable
725 * should be emitted, if so, put a new entry into CRTable
726 * and call method to generate bytecode.
727 * If not, just call method to generate bytecode.
728 * @see #genStats(List, Env)
729 *
730 * @param trees The list of trees to be visited.
731 * @param env The environment to use.
732 * @param crtFlags The CharacterRangeTable flags
733 * indicating type of the entry.
734 */
735 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
736 if (!genCrt) {
737 genStats(trees, env);
738 return;
739 }
740 if (trees.length() == 1) { // mark one statement with the flags
741 genStat(trees.head, env, crtFlags | CRT_STATEMENT);
742 } else {
743 int startpc = code.curPc();
744 genStats(trees, env);
745 code.crt.put(trees, crtFlags, startpc, code.curPc());
746 }
747 }
749 /** Derived visitor method: generate code for a list of statements.
750 */
751 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) {
752 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
753 genStat(l.head, env, CRT_STATEMENT);
754 }
756 /** Derived visitor method: check whether CharacterRangeTable
757 * should be emitted, if so, put a new entry into CRTable
758 * and call method to generate bytecode.
759 * If not, just call method to generate bytecode.
760 * @see #genCond(Tree,boolean)
761 *
762 * @param tree The tree to be visited.
763 * @param crtFlags The CharacterRangeTable flags
764 * indicating type of the entry.
765 */
766 public CondItem genCond(JCTree tree, int crtFlags) {
767 if (!genCrt) return genCond(tree, false);
768 int startpc = code.curPc();
769 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
770 code.crt.put(tree, crtFlags, startpc, code.curPc());
771 return item;
772 }
774 /** Derived visitor method: generate code for a boolean
775 * expression in a control-flow context.
776 * @param _tree The expression to be visited.
777 * @param markBranches The flag to indicate that the condition is
778 * a flow controller so produced conditions
779 * should contain a proper tree to generate
780 * CharacterRangeTable branches for them.
781 */
782 public CondItem genCond(JCTree _tree, boolean markBranches) {
783 JCTree inner_tree = TreeInfo.skipParens(_tree);
784 if (inner_tree.getTag() == JCTree.CONDEXPR) {
785 JCConditional tree = (JCConditional)inner_tree;
786 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
787 if (cond.isTrue()) {
788 code.resolve(cond.trueJumps);
789 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
790 if (markBranches) result.tree = tree.truepart;
791 return result;
792 }
793 if (cond.isFalse()) {
794 code.resolve(cond.falseJumps);
795 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
796 if (markBranches) result.tree = tree.falsepart;
797 return result;
798 }
799 Chain secondJumps = cond.jumpFalse();
800 code.resolve(cond.trueJumps);
801 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
802 if (markBranches) first.tree = tree.truepart;
803 Chain falseJumps = first.jumpFalse();
804 code.resolve(first.trueJumps);
805 Chain trueJumps = code.branch(goto_);
806 code.resolve(secondJumps);
807 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
808 CondItem result = items.makeCondItem(second.opcode,
809 code.mergeChains(trueJumps, second.trueJumps),
810 code.mergeChains(falseJumps, second.falseJumps));
811 if (markBranches) result.tree = tree.falsepart;
812 return result;
813 } else {
814 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
815 if (markBranches) result.tree = _tree;
816 return result;
817 }
818 }
820 /** Visitor method: generate code for an expression, catching and reporting
821 * any completion failures.
822 * @param tree The expression to be visited.
823 * @param pt The expression's expected type (proto-type).
824 */
825 public Item genExpr(JCTree tree, Type pt) {
826 Type prevPt = this.pt;
827 try {
828 if (tree.type.constValue() != null) {
829 // Short circuit any expressions which are constants
830 checkStringConstant(tree.pos(), tree.type.constValue());
831 result = items.makeImmediateItem(tree.type, tree.type.constValue());
832 } else {
833 this.pt = pt;
834 tree.accept(this);
835 }
836 return result.coerce(pt);
837 } catch (CompletionFailure ex) {
838 chk.completionError(tree.pos(), ex);
839 code.state.stacksize = 1;
840 return items.makeStackItem(pt);
841 } finally {
842 this.pt = prevPt;
843 }
844 }
846 /** Derived visitor method: generate code for a list of method arguments.
847 * @param trees The argument expressions to be visited.
848 * @param pts The expression's expected types (i.e. the formal parameter
849 * types of the invoked method).
850 */
851 public void genArgs(List<JCExpression> trees, List<Type> pts) {
852 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
853 genExpr(l.head, pts.head).load();
854 pts = pts.tail;
855 }
856 // require lists be of same length
857 assert pts.isEmpty();
858 }
860 /* ************************************************************************
861 * Visitor methods for statements and definitions
862 *************************************************************************/
864 /** Thrown when the byte code size exceeds limit.
865 */
866 public static class CodeSizeOverflow extends RuntimeException {
867 private static final long serialVersionUID = 0;
868 public CodeSizeOverflow() {}
869 }
871 public void visitMethodDef(JCMethodDecl tree) {
872 // Create a new local environment that points pack at method
873 // definition.
874 Env<GenContext> localEnv = env.dup(tree);
875 localEnv.enclMethod = tree;
877 // The expected type of every return statement in this method
878 // is the method's return type.
879 this.pt = tree.sym.erasure(types).getReturnType();
881 checkDimension(tree.pos(), tree.sym.erasure(types));
882 genMethod(tree, localEnv, false);
883 }
884 //where
885 /** Generate code for a method.
886 * @param tree The tree representing the method definition.
887 * @param env The environment current for the method body.
888 * @param fatcode A flag that indicates whether all jumps are
889 * within 32K. We first invoke this method under
890 * the assumption that fatcode == false, i.e. all
891 * jumps are within 32K. If this fails, fatcode
892 * is set to true and we try again.
893 */
894 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
895 MethodSymbol meth = tree.sym;
896 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
897 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) +
898 (((tree.mods.flags & STATIC) == 0 || meth.isConstructor()) ? 1 : 0) >
899 ClassFile.MAX_PARAMETERS) {
900 log.error(tree.pos(), "limit.parameters");
901 nerrs++;
902 }
904 else if (tree.body != null) {
905 // Create a new code structure and initialize it.
906 int startpcCrt = initCode(tree, env, fatcode);
908 try {
909 genStat(tree.body, env);
910 } catch (CodeSizeOverflow e) {
911 // Failed due to code limit, try again with jsr/ret
912 startpcCrt = initCode(tree, env, fatcode);
913 genStat(tree.body, env);
914 }
916 if (code.state.stacksize != 0) {
917 log.error(tree.body.pos(), "stack.sim.error", tree);
918 throw new AssertionError();
919 }
921 // If last statement could complete normally, insert a
922 // return at the end.
923 if (code.isAlive()) {
924 code.statBegin(TreeInfo.endPos(tree.body));
925 if (env.enclMethod == null ||
926 env.enclMethod.sym.type.getReturnType().tag == VOID) {
927 code.emitop0(return_);
928 } else {
929 // sometime dead code seems alive (4415991);
930 // generate a small loop instead
931 int startpc = code.entryPoint();
932 CondItem c = items.makeCondItem(goto_);
933 code.resolve(c.jumpTrue(), startpc);
934 }
935 }
936 if (genCrt)
937 code.crt.put(tree.body,
938 CRT_BLOCK,
939 startpcCrt,
940 code.curPc());
942 // End the scope of all local variables in variable info.
943 code.endScopes(0);
945 // If we exceeded limits, panic
946 if (code.checkLimits(tree.pos(), log)) {
947 nerrs++;
948 return;
949 }
951 // If we generated short code but got a long jump, do it again
952 // with fatCode = true.
953 if (!fatcode && code.fatcode) genMethod(tree, env, true);
955 // Clean up
956 if(stackMap == StackMapFormat.JSR202) {
957 code.lastFrame = null;
958 code.frameBeforeLast = null;
959 }
960 }
961 }
963 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
964 MethodSymbol meth = tree.sym;
966 // Create a new code structure.
967 meth.code = code = new Code(meth,
968 fatcode,
969 lineDebugInfo ? toplevel.lineMap : null,
970 varDebugInfo,
971 stackMap,
972 debugCode,
973 genCrt ? new CRTable(tree, env.toplevel.endPositions)
974 : null,
975 syms,
976 types,
977 pool);
978 items = new Items(pool, code, syms, types);
979 if (code.debugCode)
980 System.err.println(meth + " for body " + tree);
982 // If method is not static, create a new local variable address
983 // for `this'.
984 if ((tree.mods.flags & STATIC) == 0) {
985 Type selfType = meth.owner.type;
986 if (meth.isConstructor() && selfType != syms.objectType)
987 selfType = UninitializedType.uninitializedThis(selfType);
988 code.setDefined(
989 code.newLocal(
990 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
991 }
993 // Mark all parameters as defined from the beginning of
994 // the method.
995 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
996 checkDimension(l.head.pos(), l.head.sym.type);
997 code.setDefined(code.newLocal(l.head.sym));
998 }
1000 // Get ready to generate code for method body.
1001 int startpcCrt = genCrt ? code.curPc() : 0;
1002 code.entryPoint();
1004 // Suppress initial stackmap
1005 code.pendingStackMap = false;
1007 return startpcCrt;
1008 }
1010 public void visitVarDef(JCVariableDecl tree) {
1011 VarSymbol v = tree.sym;
1012 code.newLocal(v);
1013 if (tree.init != null) {
1014 checkStringConstant(tree.init.pos(), v.getConstValue());
1015 if (v.getConstValue() == null || varDebugInfo) {
1016 genExpr(tree.init, v.erasure(types)).load();
1017 items.makeLocalItem(v).store();
1018 }
1019 }
1020 checkDimension(tree.pos(), v.type);
1021 }
1023 public void visitSkip(JCSkip tree) {
1024 }
1026 public void visitBlock(JCBlock tree) {
1027 int limit = code.nextreg;
1028 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1029 genStats(tree.stats, localEnv);
1030 // End the scope of all block-local variables in variable info.
1031 if (env.tree.getTag() != JCTree.METHODDEF) {
1032 code.statBegin(tree.endpos);
1033 code.endScopes(limit);
1034 code.pendingStatPos = Position.NOPOS;
1035 }
1036 }
1038 public void visitDoLoop(JCDoWhileLoop tree) {
1039 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), false);
1040 }
1042 public void visitWhileLoop(JCWhileLoop tree) {
1043 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), true);
1044 }
1046 public void visitForLoop(JCForLoop tree) {
1047 int limit = code.nextreg;
1048 genStats(tree.init, env);
1049 genLoop(tree, tree.body, tree.cond, tree.step, true);
1050 code.endScopes(limit);
1051 }
1052 //where
1053 /** Generate code for a loop.
1054 * @param loop The tree representing the loop.
1055 * @param body The loop's body.
1056 * @param cond The loop's controling condition.
1057 * @param step "Step" statements to be inserted at end of
1058 * each iteration.
1059 * @param testFirst True if the loop test belongs before the body.
1060 */
1061 private void genLoop(JCStatement loop,
1062 JCStatement body,
1063 JCExpression cond,
1064 List<JCExpressionStatement> step,
1065 boolean testFirst) {
1066 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1067 int startpc = code.entryPoint();
1068 if (testFirst) {
1069 CondItem c;
1070 if (cond != null) {
1071 code.statBegin(cond.pos);
1072 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1073 } else {
1074 c = items.makeCondItem(goto_);
1075 }
1076 Chain loopDone = c.jumpFalse();
1077 code.resolve(c.trueJumps);
1078 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1079 code.resolve(loopEnv.info.cont);
1080 genStats(step, loopEnv);
1081 code.resolve(code.branch(goto_), startpc);
1082 code.resolve(loopDone);
1083 } else {
1084 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1085 code.resolve(loopEnv.info.cont);
1086 genStats(step, loopEnv);
1087 CondItem c;
1088 if (cond != null) {
1089 code.statBegin(cond.pos);
1090 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1091 } else {
1092 c = items.makeCondItem(goto_);
1093 }
1094 code.resolve(c.jumpTrue(), startpc);
1095 code.resolve(c.falseJumps);
1096 }
1097 code.resolve(loopEnv.info.exit);
1098 }
1100 public void visitForeachLoop(JCEnhancedForLoop tree) {
1101 throw new AssertionError(); // should have been removed by Lower.
1102 }
1104 public void visitLabelled(JCLabeledStatement tree) {
1105 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1106 genStat(tree.body, localEnv, CRT_STATEMENT);
1107 code.resolve(localEnv.info.exit);
1108 }
1110 public void visitSwitch(JCSwitch tree) {
1111 int limit = code.nextreg;
1112 assert tree.selector.type.tag != CLASS;
1113 int startpcCrt = genCrt ? code.curPc() : 0;
1114 Item sel = genExpr(tree.selector, syms.intType);
1115 List<JCCase> cases = tree.cases;
1116 if (cases.isEmpty()) {
1117 // We are seeing: switch <sel> {}
1118 sel.load().drop();
1119 if (genCrt)
1120 code.crt.put(TreeInfo.skipParens(tree.selector),
1121 CRT_FLOW_CONTROLLER, startpcCrt, code.curPc());
1122 } else {
1123 // We are seeing a nonempty switch.
1124 sel.load();
1125 if (genCrt)
1126 code.crt.put(TreeInfo.skipParens(tree.selector),
1127 CRT_FLOW_CONTROLLER, startpcCrt, code.curPc());
1128 Env<GenContext> switchEnv = env.dup(tree, new GenContext());
1129 switchEnv.info.isSwitch = true;
1131 // Compute number of labels and minimum and maximum label values.
1132 // For each case, store its label in an array.
1133 int lo = Integer.MAX_VALUE; // minimum label.
1134 int hi = Integer.MIN_VALUE; // maximum label.
1135 int nlabels = 0; // number of labels.
1137 int[] labels = new int[cases.length()]; // the label array.
1138 int defaultIndex = -1; // the index of the default clause.
1140 List<JCCase> l = cases;
1141 for (int i = 0; i < labels.length; i++) {
1142 if (l.head.pat != null) {
1143 int val = ((Number)l.head.pat.type.constValue()).intValue();
1144 labels[i] = val;
1145 if (val < lo) lo = val;
1146 if (hi < val) hi = val;
1147 nlabels++;
1148 } else {
1149 assert defaultIndex == -1;
1150 defaultIndex = i;
1151 }
1152 l = l.tail;
1153 }
1155 // Determine whether to issue a tableswitch or a lookupswitch
1156 // instruction.
1157 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1158 long table_time_cost = 3; // comparisons
1159 long lookup_space_cost = 3 + 2 * (long) nlabels;
1160 long lookup_time_cost = nlabels;
1161 int opcode =
1162 nlabels > 0 &&
1163 table_space_cost + 3 * table_time_cost <=
1164 lookup_space_cost + 3 * lookup_time_cost
1165 ?
1166 tableswitch : lookupswitch;
1168 int startpc = code.curPc(); // the position of the selector operation
1169 code.emitop0(opcode);
1170 code.align(4);
1171 int tableBase = code.curPc(); // the start of the jump table
1172 int[] offsets = null; // a table of offsets for a lookupswitch
1173 code.emit4(-1); // leave space for default offset
1174 if (opcode == tableswitch) {
1175 code.emit4(lo); // minimum label
1176 code.emit4(hi); // maximum label
1177 for (long i = lo; i <= hi; i++) { // leave space for jump table
1178 code.emit4(-1);
1179 }
1180 } else {
1181 code.emit4(nlabels); // number of labels
1182 for (int i = 0; i < nlabels; i++) {
1183 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1184 }
1185 offsets = new int[labels.length];
1186 }
1187 Code.State stateSwitch = code.state.dup();
1188 code.markDead();
1190 // For each case do:
1191 l = cases;
1192 for (int i = 0; i < labels.length; i++) {
1193 JCCase c = l.head;
1194 l = l.tail;
1196 int pc = code.entryPoint(stateSwitch);
1197 // Insert offset directly into code or else into the
1198 // offsets table.
1199 if (i != defaultIndex) {
1200 if (opcode == tableswitch) {
1201 code.put4(
1202 tableBase + 4 * (labels[i] - lo + 3),
1203 pc - startpc);
1204 } else {
1205 offsets[i] = pc - startpc;
1206 }
1207 } else {
1208 code.put4(tableBase, pc - startpc);
1209 }
1211 // Generate code for the statements in this case.
1212 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1213 }
1215 // Resolve all breaks.
1216 code.resolve(switchEnv.info.exit);
1218 // If we have not set the default offset, we do so now.
1219 if (code.get4(tableBase) == -1) {
1220 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1221 }
1223 if (opcode == tableswitch) {
1224 // Let any unfilled slots point to the default case.
1225 int defaultOffset = code.get4(tableBase);
1226 for (long i = lo; i <= hi; i++) {
1227 int t = (int)(tableBase + 4 * (i - lo + 3));
1228 if (code.get4(t) == -1)
1229 code.put4(t, defaultOffset);
1230 }
1231 } else {
1232 // Sort non-default offsets and copy into lookup table.
1233 if (defaultIndex >= 0)
1234 for (int i = defaultIndex; i < labels.length - 1; i++) {
1235 labels[i] = labels[i+1];
1236 offsets[i] = offsets[i+1];
1237 }
1238 if (nlabels > 0)
1239 qsort2(labels, offsets, 0, nlabels - 1);
1240 for (int i = 0; i < nlabels; i++) {
1241 int caseidx = tableBase + 8 * (i + 1);
1242 code.put4(caseidx, labels[i]);
1243 code.put4(caseidx + 4, offsets[i]);
1244 }
1245 }
1246 }
1247 code.endScopes(limit);
1248 }
1249 //where
1250 /** Sort (int) arrays of keys and values
1251 */
1252 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1253 int i = lo;
1254 int j = hi;
1255 int pivot = keys[(i+j)/2];
1256 do {
1257 while (keys[i] < pivot) i++;
1258 while (pivot < keys[j]) j--;
1259 if (i <= j) {
1260 int temp1 = keys[i];
1261 keys[i] = keys[j];
1262 keys[j] = temp1;
1263 int temp2 = values[i];
1264 values[i] = values[j];
1265 values[j] = temp2;
1266 i++;
1267 j--;
1268 }
1269 } while (i <= j);
1270 if (lo < j) qsort2(keys, values, lo, j);
1271 if (i < hi) qsort2(keys, values, i, hi);
1272 }
1274 public void visitSynchronized(JCSynchronized tree) {
1275 int limit = code.nextreg;
1276 // Generate code to evaluate lock and save in temporary variable.
1277 final LocalItem lockVar = makeTemp(syms.objectType);
1278 genExpr(tree.lock, tree.lock.type).load().duplicate();
1279 lockVar.store();
1281 // Generate code to enter monitor.
1282 code.emitop0(monitorenter);
1283 code.state.lock(lockVar.reg);
1285 // Generate code for a try statement with given body, no catch clauses
1286 // in a new environment with the "exit-monitor" operation as finalizer.
1287 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1288 syncEnv.info.finalize = new GenFinalizer() {
1289 void gen() {
1290 genLast();
1291 assert syncEnv.info.gaps.length() % 2 == 0;
1292 syncEnv.info.gaps.append(code.curPc());
1293 }
1294 void genLast() {
1295 if (code.isAlive()) {
1296 lockVar.load();
1297 code.emitop0(monitorexit);
1298 code.state.unlock(lockVar.reg);
1299 }
1300 }
1301 };
1302 syncEnv.info.gaps = new ListBuffer<Integer>();
1303 genTry(tree.body, List.<JCCatch>nil(), syncEnv);
1304 code.endScopes(limit);
1305 }
1307 public void visitTry(final JCTry tree) {
1308 // Generate code for a try statement with given body and catch clauses,
1309 // in a new environment which calls the finally block if there is one.
1310 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1311 final Env<GenContext> oldEnv = env;
1312 if (!useJsrLocally) {
1313 useJsrLocally =
1314 (stackMap == StackMapFormat.NONE) &&
1315 (jsrlimit <= 0 ||
1316 jsrlimit < 100 &&
1317 estimateCodeComplexity(tree.finalizer)>jsrlimit);
1318 }
1319 tryEnv.info.finalize = new GenFinalizer() {
1320 void gen() {
1321 if (useJsrLocally) {
1322 if (tree.finalizer != null) {
1323 Code.State jsrState = code.state.dup();
1324 jsrState.push(code.jsrReturnValue);
1325 tryEnv.info.cont =
1326 new Chain(code.emitJump(jsr),
1327 tryEnv.info.cont,
1328 jsrState);
1329 }
1330 assert tryEnv.info.gaps.length() % 2 == 0;
1331 tryEnv.info.gaps.append(code.curPc());
1332 } else {
1333 assert tryEnv.info.gaps.length() % 2 == 0;
1334 tryEnv.info.gaps.append(code.curPc());
1335 genLast();
1336 }
1337 }
1338 void genLast() {
1339 if (tree.finalizer != null)
1340 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1341 }
1342 boolean hasFinalizer() {
1343 return tree.finalizer != null;
1344 }
1345 };
1346 tryEnv.info.gaps = new ListBuffer<Integer>();
1347 genTry(tree.body, tree.catchers, tryEnv);
1348 }
1349 //where
1350 /** Generate code for a try or synchronized statement
1351 * @param body The body of the try or synchronized statement.
1352 * @param catchers The lis of catch clauses.
1353 * @param env the environment current for the body.
1354 */
1355 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1356 int limit = code.nextreg;
1357 int startpc = code.curPc();
1358 Code.State stateTry = code.state.dup();
1359 genStat(body, env, CRT_BLOCK);
1360 int endpc = code.curPc();
1361 boolean hasFinalizer =
1362 env.info.finalize != null &&
1363 env.info.finalize.hasFinalizer();
1364 List<Integer> gaps = env.info.gaps.toList();
1365 code.statBegin(TreeInfo.endPos(body));
1366 genFinalizer(env);
1367 code.statBegin(TreeInfo.endPos(env.tree));
1368 Chain exitChain = code.branch(goto_);
1369 endFinalizerGap(env);
1370 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1371 // start off with exception on stack
1372 code.entryPoint(stateTry, l.head.param.sym.type);
1373 genCatch(l.head, env, startpc, endpc, gaps);
1374 genFinalizer(env);
1375 if (hasFinalizer || l.tail.nonEmpty()) {
1376 code.statBegin(TreeInfo.endPos(env.tree));
1377 exitChain = code.mergeChains(exitChain,
1378 code.branch(goto_));
1379 }
1380 endFinalizerGap(env);
1381 }
1382 if (hasFinalizer) {
1383 // Create a new register segement to avoid allocating
1384 // the same variables in finalizers and other statements.
1385 code.newRegSegment();
1387 // Add a catch-all clause.
1389 // start off with exception on stack
1390 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1392 // Register all exception ranges for catch all clause.
1393 // The range of the catch all clause is from the beginning
1394 // of the try or synchronized block until the present
1395 // code pointer excluding all gaps in the current
1396 // environment's GenContext.
1397 int startseg = startpc;
1398 while (env.info.gaps.nonEmpty()) {
1399 int endseg = env.info.gaps.next().intValue();
1400 registerCatch(body.pos(), startseg, endseg,
1401 catchallpc, 0);
1402 startseg = env.info.gaps.next().intValue();
1403 }
1404 code.statBegin(TreeInfo.finalizerPos(env.tree));
1405 code.markStatBegin();
1407 Item excVar = makeTemp(syms.throwableType);
1408 excVar.store();
1409 genFinalizer(env);
1410 excVar.load();
1411 registerCatch(body.pos(), startseg,
1412 env.info.gaps.next().intValue(),
1413 catchallpc, 0);
1414 code.emitop0(athrow);
1415 code.markDead();
1417 // If there are jsr's to this finalizer, ...
1418 if (env.info.cont != null) {
1419 // Resolve all jsr's.
1420 code.resolve(env.info.cont);
1422 // Mark statement line number
1423 code.statBegin(TreeInfo.finalizerPos(env.tree));
1424 code.markStatBegin();
1426 // Save return address.
1427 LocalItem retVar = makeTemp(syms.throwableType);
1428 retVar.store();
1430 // Generate finalizer code.
1431 env.info.finalize.genLast();
1433 // Return.
1434 code.emitop1w(ret, retVar.reg);
1435 code.markDead();
1436 }
1437 }
1439 // Resolve all breaks.
1440 code.resolve(exitChain);
1442 // End the scopes of all try-local variables in variable info.
1443 code.endScopes(limit);
1444 }
1446 /** Generate code for a catch clause.
1447 * @param tree The catch clause.
1448 * @param env The environment current in the enclosing try.
1449 * @param startpc Start pc of try-block.
1450 * @param endpc End pc of try-block.
1451 */
1452 void genCatch(JCCatch tree,
1453 Env<GenContext> env,
1454 int startpc, int endpc,
1455 List<Integer> gaps) {
1456 if (startpc != endpc) {
1457 int catchType = makeRef(tree.pos(), tree.param.type);
1458 while (gaps.nonEmpty()) {
1459 int end = gaps.head.intValue();
1460 registerCatch(tree.pos(),
1461 startpc, end, code.curPc(),
1462 catchType);
1463 gaps = gaps.tail;
1464 startpc = gaps.head.intValue();
1465 gaps = gaps.tail;
1466 }
1467 if (startpc < endpc)
1468 registerCatch(tree.pos(),
1469 startpc, endpc, code.curPc(),
1470 catchType);
1471 VarSymbol exparam = tree.param.sym;
1472 code.statBegin(tree.pos);
1473 code.markStatBegin();
1474 int limit = code.nextreg;
1475 int exlocal = code.newLocal(exparam);
1476 items.makeLocalItem(exparam).store();
1477 code.statBegin(TreeInfo.firstStatPos(tree.body));
1478 genStat(tree.body, env, CRT_BLOCK);
1479 code.endScopes(limit);
1480 code.statBegin(TreeInfo.endPos(tree.body));
1481 }
1482 }
1484 /** Register a catch clause in the "Exceptions" code-attribute.
1485 */
1486 void registerCatch(DiagnosticPosition pos,
1487 int startpc, int endpc,
1488 int handler_pc, int catch_type) {
1489 if (startpc != endpc) {
1490 char startpc1 = (char)startpc;
1491 char endpc1 = (char)endpc;
1492 char handler_pc1 = (char)handler_pc;
1493 if (startpc1 == startpc &&
1494 endpc1 == endpc &&
1495 handler_pc1 == handler_pc) {
1496 code.addCatch(startpc1, endpc1, handler_pc1,
1497 (char)catch_type);
1498 } else {
1499 if (!useJsrLocally && !target.generateStackMapTable()) {
1500 useJsrLocally = true;
1501 throw new CodeSizeOverflow();
1502 } else {
1503 log.error(pos, "limit.code.too.large.for.try.stmt");
1504 nerrs++;
1505 }
1506 }
1507 }
1508 }
1510 /** Very roughly estimate the number of instructions needed for
1511 * the given tree.
1512 */
1513 int estimateCodeComplexity(JCTree tree) {
1514 if (tree == null) return 0;
1515 class ComplexityScanner extends TreeScanner {
1516 int complexity = 0;
1517 public void scan(JCTree tree) {
1518 if (complexity > jsrlimit) return;
1519 super.scan(tree);
1520 }
1521 public void visitClassDef(JCClassDecl tree) {}
1522 public void visitDoLoop(JCDoWhileLoop tree)
1523 { super.visitDoLoop(tree); complexity++; }
1524 public void visitWhileLoop(JCWhileLoop tree)
1525 { super.visitWhileLoop(tree); complexity++; }
1526 public void visitForLoop(JCForLoop tree)
1527 { super.visitForLoop(tree); complexity++; }
1528 public void visitSwitch(JCSwitch tree)
1529 { super.visitSwitch(tree); complexity+=5; }
1530 public void visitCase(JCCase tree)
1531 { super.visitCase(tree); complexity++; }
1532 public void visitSynchronized(JCSynchronized tree)
1533 { super.visitSynchronized(tree); complexity+=6; }
1534 public void visitTry(JCTry tree)
1535 { super.visitTry(tree);
1536 if (tree.finalizer != null) complexity+=6; }
1537 public void visitCatch(JCCatch tree)
1538 { super.visitCatch(tree); complexity+=2; }
1539 public void visitConditional(JCConditional tree)
1540 { super.visitConditional(tree); complexity+=2; }
1541 public void visitIf(JCIf tree)
1542 { super.visitIf(tree); complexity+=2; }
1543 // note: for break, continue, and return we don't take unwind() into account.
1544 public void visitBreak(JCBreak tree)
1545 { super.visitBreak(tree); complexity+=1; }
1546 public void visitContinue(JCContinue tree)
1547 { super.visitContinue(tree); complexity+=1; }
1548 public void visitReturn(JCReturn tree)
1549 { super.visitReturn(tree); complexity+=1; }
1550 public void visitThrow(JCThrow tree)
1551 { super.visitThrow(tree); complexity+=1; }
1552 public void visitAssert(JCAssert tree)
1553 { super.visitAssert(tree); complexity+=5; }
1554 public void visitApply(JCMethodInvocation tree)
1555 { super.visitApply(tree); complexity+=2; }
1556 public void visitNewClass(JCNewClass tree)
1557 { scan(tree.encl); scan(tree.args); complexity+=2; }
1558 public void visitNewArray(JCNewArray tree)
1559 { super.visitNewArray(tree); complexity+=5; }
1560 public void visitAssign(JCAssign tree)
1561 { super.visitAssign(tree); complexity+=1; }
1562 public void visitAssignop(JCAssignOp tree)
1563 { super.visitAssignop(tree); complexity+=2; }
1564 public void visitUnary(JCUnary tree)
1565 { complexity+=1;
1566 if (tree.type.constValue() == null) super.visitUnary(tree); }
1567 public void visitBinary(JCBinary tree)
1568 { complexity+=1;
1569 if (tree.type.constValue() == null) super.visitBinary(tree); }
1570 public void visitTypeTest(JCInstanceOf tree)
1571 { super.visitTypeTest(tree); complexity+=1; }
1572 public void visitIndexed(JCArrayAccess tree)
1573 { super.visitIndexed(tree); complexity+=1; }
1574 public void visitSelect(JCFieldAccess tree)
1575 { super.visitSelect(tree);
1576 if (tree.sym.kind == VAR) complexity+=1; }
1577 public void visitIdent(JCIdent tree) {
1578 if (tree.sym.kind == VAR) {
1579 complexity+=1;
1580 if (tree.type.constValue() == null &&
1581 tree.sym.owner.kind == TYP)
1582 complexity+=1;
1583 }
1584 }
1585 public void visitLiteral(JCLiteral tree)
1586 { complexity+=1; }
1587 public void visitTree(JCTree tree) {}
1588 public void visitWildcard(JCWildcard tree) {
1589 throw new AssertionError(this.getClass().getName());
1590 }
1591 }
1592 ComplexityScanner scanner = new ComplexityScanner();
1593 tree.accept(scanner);
1594 return scanner.complexity;
1595 }
1597 public void visitIf(JCIf tree) {
1598 int limit = code.nextreg;
1599 Chain thenExit = null;
1600 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1601 CRT_FLOW_CONTROLLER);
1602 Chain elseChain = c.jumpFalse();
1603 if (!c.isFalse()) {
1604 code.resolve(c.trueJumps);
1605 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1606 thenExit = code.branch(goto_);
1607 }
1608 if (elseChain != null) {
1609 code.resolve(elseChain);
1610 if (tree.elsepart != null)
1611 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1612 }
1613 code.resolve(thenExit);
1614 code.endScopes(limit);
1615 }
1617 public void visitExec(JCExpressionStatement tree) {
1618 // Optimize x++ to ++x and x-- to --x.
1619 JCExpression e = tree.expr;
1620 switch (e.getTag()) {
1621 case JCTree.POSTINC:
1622 ((JCUnary) e).setTag(JCTree.PREINC);
1623 break;
1624 case JCTree.POSTDEC:
1625 ((JCUnary) e).setTag(JCTree.PREDEC);
1626 break;
1627 }
1628 genExpr(tree.expr, tree.expr.type).drop();
1629 }
1631 public void visitBreak(JCBreak tree) {
1632 Env<GenContext> targetEnv = unwind(tree.target, env);
1633 assert code.state.stacksize == 0;
1634 targetEnv.info.addExit(code.branch(goto_));
1635 endFinalizerGaps(env, targetEnv);
1636 }
1638 public void visitContinue(JCContinue tree) {
1639 Env<GenContext> targetEnv = unwind(tree.target, env);
1640 assert code.state.stacksize == 0;
1641 targetEnv.info.addCont(code.branch(goto_));
1642 endFinalizerGaps(env, targetEnv);
1643 }
1645 public void visitReturn(JCReturn tree) {
1646 int limit = code.nextreg;
1647 final Env<GenContext> targetEnv;
1648 if (tree.expr != null) {
1649 Item r = genExpr(tree.expr, pt).load();
1650 if (hasFinally(env.enclMethod, env)) {
1651 r = makeTemp(pt);
1652 r.store();
1653 }
1654 targetEnv = unwind(env.enclMethod, env);
1655 r.load();
1656 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
1657 } else {
1658 targetEnv = unwind(env.enclMethod, env);
1659 code.emitop0(return_);
1660 }
1661 endFinalizerGaps(env, targetEnv);
1662 code.endScopes(limit);
1663 }
1665 public void visitThrow(JCThrow tree) {
1666 genExpr(tree.expr, tree.expr.type).load();
1667 code.emitop0(athrow);
1668 }
1670 /* ************************************************************************
1671 * Visitor methods for expressions
1672 *************************************************************************/
1674 public void visitApply(JCMethodInvocation tree) {
1675 // Generate code for method.
1676 Item m = genExpr(tree.meth, methodType);
1677 // Generate code for all arguments, where the expected types are
1678 // the parameters of the method's external type (that is, any implicit
1679 // outer instance of a super(...) call appears as first parameter).
1680 genArgs(tree.args,
1681 TreeInfo.symbol(tree.meth).externalType(types).getParameterTypes());
1682 result = m.invoke();
1683 }
1685 public void visitConditional(JCConditional tree) {
1686 Chain thenExit = null;
1687 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
1688 Chain elseChain = c.jumpFalse();
1689 if (!c.isFalse()) {
1690 code.resolve(c.trueJumps);
1691 int startpc = genCrt ? code.curPc() : 0;
1692 genExpr(tree.truepart, pt).load();
1693 code.state.forceStackTop(tree.type);
1694 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
1695 startpc, code.curPc());
1696 thenExit = code.branch(goto_);
1697 }
1698 if (elseChain != null) {
1699 code.resolve(elseChain);
1700 int startpc = genCrt ? code.curPc() : 0;
1701 genExpr(tree.falsepart, pt).load();
1702 code.state.forceStackTop(tree.type);
1703 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
1704 startpc, code.curPc());
1705 }
1706 code.resolve(thenExit);
1707 result = items.makeStackItem(pt);
1708 }
1710 public void visitNewClass(JCNewClass tree) {
1711 // Enclosing instances or anonymous classes should have been eliminated
1712 // by now.
1713 assert tree.encl == null && tree.def == null;
1715 code.emitop2(new_, makeRef(tree.pos(), tree.type));
1716 code.emitop0(dup);
1718 // Generate code for all arguments, where the expected types are
1719 // the parameters of the constructor's external type (that is,
1720 // any implicit outer instance appears as first parameter).
1721 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
1723 items.makeMemberItem(tree.constructor, true).invoke();
1724 result = items.makeStackItem(tree.type);
1725 }
1727 public void visitNewArray(JCNewArray tree) {
1728 if (tree.elems != null) {
1729 Type elemtype = types.elemtype(tree.type);
1730 loadIntConst(tree.elems.length());
1731 Item arr = makeNewArray(tree.pos(), tree.type, 1);
1732 int i = 0;
1733 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
1734 arr.duplicate();
1735 loadIntConst(i);
1736 i++;
1737 genExpr(l.head, elemtype).load();
1738 items.makeIndexedItem(elemtype).store();
1739 }
1740 result = arr;
1741 } else {
1742 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1743 genExpr(l.head, syms.intType).load();
1744 }
1745 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
1746 }
1747 }
1748 //where
1749 /** Generate code to create an array with given element type and number
1750 * of dimensions.
1751 */
1752 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
1753 Type elemtype = types.elemtype(type);
1754 if (types.dimensions(elemtype) + ndims > ClassFile.MAX_DIMENSIONS) {
1755 log.error(pos, "limit.dimensions");
1756 nerrs++;
1757 }
1758 int elemcode = Code.arraycode(elemtype);
1759 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
1760 code.emitAnewarray(makeRef(pos, elemtype), type);
1761 } else if (elemcode == 1) {
1762 code.emitMultianewarray(ndims, makeRef(pos, type), type);
1763 } else {
1764 code.emitNewarray(elemcode, type);
1765 }
1766 return items.makeStackItem(type);
1767 }
1769 public void visitParens(JCParens tree) {
1770 result = genExpr(tree.expr, tree.expr.type);
1771 }
1773 public void visitAssign(JCAssign tree) {
1774 Item l = genExpr(tree.lhs, tree.lhs.type);
1775 genExpr(tree.rhs, tree.lhs.type).load();
1776 result = items.makeAssignItem(l);
1777 }
1779 public void visitAssignop(JCAssignOp tree) {
1780 OperatorSymbol operator = (OperatorSymbol) tree.operator;
1781 Item l;
1782 if (operator.opcode == string_add) {
1783 // Generate code to make a string buffer
1784 makeStringBuffer(tree.pos());
1786 // Generate code for first string, possibly save one
1787 // copy under buffer
1788 l = genExpr(tree.lhs, tree.lhs.type);
1789 if (l.width() > 0) {
1790 code.emitop0(dup_x1 + 3 * (l.width() - 1));
1791 }
1793 // Load first string and append to buffer.
1794 l.load();
1795 appendString(tree.lhs);
1797 // Append all other strings to buffer.
1798 appendStrings(tree.rhs);
1800 // Convert buffer to string.
1801 bufferToString(tree.pos());
1802 } else {
1803 // Generate code for first expression
1804 l = genExpr(tree.lhs, tree.lhs.type);
1806 // If we have an increment of -32768 to +32767 of a local
1807 // int variable we can use an incr instruction instead of
1808 // proceeding further.
1809 if ((tree.getTag() == JCTree.PLUS_ASG || tree.getTag() == JCTree.MINUS_ASG) &&
1810 l instanceof LocalItem &&
1811 tree.lhs.type.tag <= INT &&
1812 tree.rhs.type.tag <= INT &&
1813 tree.rhs.type.constValue() != null) {
1814 int ival = ((Number) tree.rhs.type.constValue()).intValue();
1815 if (tree.getTag() == JCTree.MINUS_ASG) ival = -ival;
1816 ((LocalItem)l).incr(ival);
1817 result = l;
1818 return;
1819 }
1820 // Otherwise, duplicate expression, load one copy
1821 // and complete binary operation.
1822 l.duplicate();
1823 l.coerce(operator.type.getParameterTypes().head).load();
1824 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
1825 }
1826 result = items.makeAssignItem(l);
1827 }
1829 public void visitUnary(JCUnary tree) {
1830 OperatorSymbol operator = (OperatorSymbol)tree.operator;
1831 if (tree.getTag() == JCTree.NOT) {
1832 CondItem od = genCond(tree.arg, false);
1833 result = od.negate();
1834 } else {
1835 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
1836 switch (tree.getTag()) {
1837 case JCTree.POS:
1838 result = od.load();
1839 break;
1840 case JCTree.NEG:
1841 result = od.load();
1842 code.emitop0(operator.opcode);
1843 break;
1844 case JCTree.COMPL:
1845 result = od.load();
1846 emitMinusOne(od.typecode);
1847 code.emitop0(operator.opcode);
1848 break;
1849 case JCTree.PREINC: case JCTree.PREDEC:
1850 od.duplicate();
1851 if (od instanceof LocalItem &&
1852 (operator.opcode == iadd || operator.opcode == isub)) {
1853 ((LocalItem)od).incr(tree.getTag() == JCTree.PREINC ? 1 : -1);
1854 result = od;
1855 } else {
1856 od.load();
1857 code.emitop0(one(od.typecode));
1858 code.emitop0(operator.opcode);
1859 // Perform narrowing primitive conversion if byte,
1860 // char, or short. Fix for 4304655.
1861 if (od.typecode != INTcode &&
1862 Code.truncate(od.typecode) == INTcode)
1863 code.emitop0(int2byte + od.typecode - BYTEcode);
1864 result = items.makeAssignItem(od);
1865 }
1866 break;
1867 case JCTree.POSTINC: case JCTree.POSTDEC:
1868 od.duplicate();
1869 if (od instanceof LocalItem &&
1870 (operator.opcode == iadd || operator.opcode == isub)) {
1871 Item res = od.load();
1872 ((LocalItem)od).incr(tree.getTag() == JCTree.POSTINC ? 1 : -1);
1873 result = res;
1874 } else {
1875 Item res = od.load();
1876 od.stash(od.typecode);
1877 code.emitop0(one(od.typecode));
1878 code.emitop0(operator.opcode);
1879 // Perform narrowing primitive conversion if byte,
1880 // char, or short. Fix for 4304655.
1881 if (od.typecode != INTcode &&
1882 Code.truncate(od.typecode) == INTcode)
1883 code.emitop0(int2byte + od.typecode - BYTEcode);
1884 od.store();
1885 result = res;
1886 }
1887 break;
1888 case JCTree.NULLCHK:
1889 result = od.load();
1890 code.emitop0(dup);
1891 genNullCheck(tree.pos());
1892 break;
1893 default:
1894 assert false;
1895 }
1896 }
1897 }
1899 /** Generate a null check from the object value at stack top. */
1900 private void genNullCheck(DiagnosticPosition pos) {
1901 callMethod(pos, syms.objectType, names.getClass,
1902 List.<Type>nil(), false);
1903 code.emitop0(pop);
1904 }
1906 public void visitBinary(JCBinary tree) {
1907 OperatorSymbol operator = (OperatorSymbol)tree.operator;
1908 if (operator.opcode == string_add) {
1909 // Create a string buffer.
1910 makeStringBuffer(tree.pos());
1911 // Append all strings to buffer.
1912 appendStrings(tree);
1913 // Convert buffer to string.
1914 bufferToString(tree.pos());
1915 result = items.makeStackItem(syms.stringType);
1916 } else if (tree.getTag() == JCTree.AND) {
1917 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
1918 if (!lcond.isFalse()) {
1919 Chain falseJumps = lcond.jumpFalse();
1920 code.resolve(lcond.trueJumps);
1921 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
1922 result = items.
1923 makeCondItem(rcond.opcode,
1924 rcond.trueJumps,
1925 code.mergeChains(falseJumps,
1926 rcond.falseJumps));
1927 } else {
1928 result = lcond;
1929 }
1930 } else if (tree.getTag() == JCTree.OR) {
1931 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
1932 if (!lcond.isTrue()) {
1933 Chain trueJumps = lcond.jumpTrue();
1934 code.resolve(lcond.falseJumps);
1935 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
1936 result = items.
1937 makeCondItem(rcond.opcode,
1938 code.mergeChains(trueJumps, rcond.trueJumps),
1939 rcond.falseJumps);
1940 } else {
1941 result = lcond;
1942 }
1943 } else {
1944 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
1945 od.load();
1946 result = completeBinop(tree.lhs, tree.rhs, operator);
1947 }
1948 }
1949 //where
1950 /** Make a new string buffer.
1951 */
1952 void makeStringBuffer(DiagnosticPosition pos) {
1953 code.emitop2(new_, makeRef(pos, stringBufferType));
1954 code.emitop0(dup);
1955 callMethod(
1956 pos, stringBufferType, names.init, List.<Type>nil(), false);
1957 }
1959 /** Append value (on tos) to string buffer (on tos - 1).
1960 */
1961 void appendString(JCTree tree) {
1962 Type t = tree.type.baseType();
1963 if (t.tag > lastBaseTag && t.tsym != syms.stringType.tsym) {
1964 t = syms.objectType;
1965 }
1966 items.makeMemberItem(getStringBufferAppend(tree, t), false).invoke();
1967 }
1968 Symbol getStringBufferAppend(JCTree tree, Type t) {
1969 assert t.constValue() == null;
1970 Symbol method = stringBufferAppend.get(t);
1971 if (method == null) {
1972 method = rs.resolveInternalMethod(tree.pos(),
1973 attrEnv,
1974 stringBufferType,
1975 names.append,
1976 List.of(t),
1977 null);
1978 stringBufferAppend.put(t, method);
1979 }
1980 return method;
1981 }
1983 /** Add all strings in tree to string buffer.
1984 */
1985 void appendStrings(JCTree tree) {
1986 tree = TreeInfo.skipParens(tree);
1987 if (tree.getTag() == JCTree.PLUS && tree.type.constValue() == null) {
1988 JCBinary op = (JCBinary) tree;
1989 if (op.operator.kind == MTH &&
1990 ((OperatorSymbol) op.operator).opcode == string_add) {
1991 appendStrings(op.lhs);
1992 appendStrings(op.rhs);
1993 return;
1994 }
1995 }
1996 genExpr(tree, tree.type).load();
1997 appendString(tree);
1998 }
2000 /** Convert string buffer on tos to string.
2001 */
2002 void bufferToString(DiagnosticPosition pos) {
2003 callMethod(
2004 pos,
2005 stringBufferType,
2006 names.toString,
2007 List.<Type>nil(),
2008 false);
2009 }
2011 /** Complete generating code for operation, with left operand
2012 * already on stack.
2013 * @param lhs The tree representing the left operand.
2014 * @param rhs The tree representing the right operand.
2015 * @param operator The operator symbol.
2016 */
2017 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2018 MethodType optype = (MethodType)operator.type;
2019 int opcode = operator.opcode;
2020 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2021 rhs.type.constValue() instanceof Number &&
2022 ((Number) rhs.type.constValue()).intValue() == 0) {
2023 opcode = opcode + (ifeq - if_icmpeq);
2024 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2025 TreeInfo.isNull(rhs)) {
2026 opcode = opcode + (if_acmp_null - if_acmpeq);
2027 } else {
2028 // The expected type of the right operand is
2029 // the second parameter type of the operator, except for
2030 // shifts with long shiftcount, where we convert the opcode
2031 // to a short shift and the expected type to int.
2032 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2033 if (opcode >= ishll && opcode <= lushrl) {
2034 opcode = opcode + (ishl - ishll);
2035 rtype = syms.intType;
2036 }
2037 // Generate code for right operand and load.
2038 genExpr(rhs, rtype).load();
2039 // If there are two consecutive opcode instructions,
2040 // emit the first now.
2041 if (opcode >= (1 << preShift)) {
2042 code.emitop0(opcode >> preShift);
2043 opcode = opcode & 0xFF;
2044 }
2045 }
2046 if (opcode >= ifeq && opcode <= if_acmpne ||
2047 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2048 return items.makeCondItem(opcode);
2049 } else {
2050 code.emitop0(opcode);
2051 return items.makeStackItem(optype.restype);
2052 }
2053 }
2055 public void visitTypeCast(JCTypeCast tree) {
2056 result = genExpr(tree.expr, tree.clazz.type).load();
2057 // Additional code is only needed if we cast to a reference type
2058 // which is not statically a supertype of the expression's type.
2059 // For basic types, the coerce(...) in genExpr(...) will do
2060 // the conversion.
2061 if (tree.clazz.type.tag > lastBaseTag &&
2062 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2063 code.emitop2(checkcast, makeRef(tree.pos(), tree.clazz.type));
2064 }
2065 }
2067 public void visitWildcard(JCWildcard tree) {
2068 throw new AssertionError(this.getClass().getName());
2069 }
2071 public void visitTypeTest(JCInstanceOf tree) {
2072 genExpr(tree.expr, tree.expr.type).load();
2073 code.emitop2(instanceof_, makeRef(tree.pos(), tree.clazz.type));
2074 result = items.makeStackItem(syms.booleanType);
2075 }
2077 public void visitIndexed(JCArrayAccess tree) {
2078 genExpr(tree.indexed, tree.indexed.type).load();
2079 genExpr(tree.index, syms.intType).load();
2080 result = items.makeIndexedItem(tree.type);
2081 }
2083 public void visitIdent(JCIdent tree) {
2084 Symbol sym = tree.sym;
2085 if (tree.name == names._this || tree.name == names._super) {
2086 Item res = tree.name == names._this
2087 ? items.makeThisItem()
2088 : items.makeSuperItem();
2089 if (sym.kind == MTH) {
2090 // Generate code to address the constructor.
2091 res.load();
2092 res = items.makeMemberItem(sym, true);
2093 }
2094 result = res;
2095 } else if (sym.kind == VAR && sym.owner.kind == MTH) {
2096 result = items.makeLocalItem((VarSymbol)sym);
2097 } else if ((sym.flags() & STATIC) != 0) {
2098 if (!isAccessSuper(env.enclMethod))
2099 sym = binaryQualifier(sym, env.enclClass.type);
2100 result = items.makeStaticItem(sym);
2101 } else {
2102 items.makeThisItem().load();
2103 sym = binaryQualifier(sym, env.enclClass.type);
2104 result = items.makeMemberItem(sym, (sym.flags() & PRIVATE) != 0);
2105 }
2106 }
2108 public void visitSelect(JCFieldAccess tree) {
2109 Symbol sym = tree.sym;
2111 if (tree.name == names._class) {
2112 assert target.hasClassLiterals();
2113 code.emitop2(ldc2, makeRef(tree.pos(), tree.selected.type));
2114 result = items.makeStackItem(pt);
2115 return;
2116 }
2118 Symbol ssym = TreeInfo.symbol(tree.selected);
2120 // Are we selecting via super?
2121 boolean selectSuper =
2122 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2124 // Are we accessing a member of the superclass in an access method
2125 // resulting from a qualified super?
2126 boolean accessSuper = isAccessSuper(env.enclMethod);
2128 Item base = (selectSuper)
2129 ? items.makeSuperItem()
2130 : genExpr(tree.selected, tree.selected.type);
2132 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2133 // We are seeing a variable that is constant but its selecting
2134 // expression is not.
2135 if ((sym.flags() & STATIC) != 0) {
2136 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2137 base = base.load();
2138 base.drop();
2139 } else {
2140 base.load();
2141 genNullCheck(tree.selected.pos());
2142 }
2143 result = items.
2144 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2145 } else if (allowInvokedynamic && sym.kind == MTH && ssym == syms.invokeDynamicType.tsym) {
2146 base.drop();
2147 result = items.makeDynamicItem(sym);
2148 } else {
2149 if (!accessSuper)
2150 sym = binaryQualifier(sym, tree.selected.type);
2151 if ((sym.flags() & STATIC) != 0) {
2152 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2153 base = base.load();
2154 base.drop();
2155 result = items.makeStaticItem(sym);
2156 } else {
2157 base.load();
2158 if (sym == syms.lengthVar) {
2159 code.emitop0(arraylength);
2160 result = items.makeStackItem(syms.intType);
2161 } else {
2162 result = items.
2163 makeMemberItem(sym,
2164 (sym.flags() & PRIVATE) != 0 ||
2165 selectSuper || accessSuper);
2166 }
2167 }
2168 }
2169 }
2171 public void visitLiteral(JCLiteral tree) {
2172 if (tree.type.tag == TypeTags.BOT) {
2173 code.emitop0(aconst_null);
2174 if (types.dimensions(pt) > 1) {
2175 code.emitop2(checkcast, makeRef(tree.pos(), pt));
2176 result = items.makeStackItem(pt);
2177 } else {
2178 result = items.makeStackItem(tree.type);
2179 }
2180 }
2181 else
2182 result = items.makeImmediateItem(tree.type, tree.value);
2183 }
2185 public void visitLetExpr(LetExpr tree) {
2186 int limit = code.nextreg;
2187 genStats(tree.defs, env);
2188 result = genExpr(tree.expr, tree.expr.type).load();
2189 code.endScopes(limit);
2190 }
2192 /* ************************************************************************
2193 * main method
2194 *************************************************************************/
2196 /** Generate code for a class definition.
2197 * @param env The attribution environment that belongs to the
2198 * outermost class containing this class definition.
2199 * We need this for resolving some additional symbols.
2200 * @param cdef The tree representing the class definition.
2201 * @return True if code is generated with no errors.
2202 */
2203 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2204 try {
2205 attrEnv = env;
2206 ClassSymbol c = cdef.sym;
2207 this.toplevel = env.toplevel;
2208 this.endPositions = toplevel.endPositions;
2209 // If this is a class definition requiring Miranda methods,
2210 // add them.
2211 if (generateIproxies &&
2212 (c.flags() & (INTERFACE|ABSTRACT)) == ABSTRACT
2213 && !allowGenerics // no Miranda methods available with generics
2214 )
2215 implementInterfaceMethods(c);
2216 cdef.defs = normalizeDefs(cdef.defs, c);
2217 c.pool = pool;
2218 pool.reset();
2219 Env<GenContext> localEnv =
2220 new Env<GenContext>(cdef, new GenContext());
2221 localEnv.toplevel = env.toplevel;
2222 localEnv.enclClass = cdef;
2223 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2224 genDef(l.head, localEnv);
2225 }
2226 if (pool.numEntries() > Pool.MAX_ENTRIES) {
2227 log.error(cdef.pos(), "limit.pool");
2228 nerrs++;
2229 }
2230 if (nerrs != 0) {
2231 // if errors, discard code
2232 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2233 if (l.head.getTag() == JCTree.METHODDEF)
2234 ((JCMethodDecl) l.head).sym.code = null;
2235 }
2236 }
2237 cdef.defs = List.nil(); // discard trees
2238 return nerrs == 0;
2239 } finally {
2240 // note: this method does NOT support recursion.
2241 attrEnv = null;
2242 this.env = null;
2243 toplevel = null;
2244 endPositions = null;
2245 nerrs = 0;
2246 }
2247 }
2249 /* ************************************************************************
2250 * Auxiliary classes
2251 *************************************************************************/
2253 /** An abstract class for finalizer generation.
2254 */
2255 abstract class GenFinalizer {
2256 /** Generate code to clean up when unwinding. */
2257 abstract void gen();
2259 /** Generate code to clean up at last. */
2260 abstract void genLast();
2262 /** Does this finalizer have some nontrivial cleanup to perform? */
2263 boolean hasFinalizer() { return true; }
2264 }
2266 /** code generation contexts,
2267 * to be used as type parameter for environments.
2268 */
2269 static class GenContext {
2271 /** A chain for all unresolved jumps that exit the current environment.
2272 */
2273 Chain exit = null;
2275 /** A chain for all unresolved jumps that continue in the
2276 * current environment.
2277 */
2278 Chain cont = null;
2280 /** A closure that generates the finalizer of the current environment.
2281 * Only set for Synchronized and Try contexts.
2282 */
2283 GenFinalizer finalize = null;
2285 /** Is this a switch statement? If so, allocate registers
2286 * even when the variable declaration is unreachable.
2287 */
2288 boolean isSwitch = false;
2290 /** A list buffer containing all gaps in the finalizer range,
2291 * where a catch all exception should not apply.
2292 */
2293 ListBuffer<Integer> gaps = null;
2295 /** Add given chain to exit chain.
2296 */
2297 void addExit(Chain c) {
2298 exit = Code.mergeChains(c, exit);
2299 }
2301 /** Add given chain to cont chain.
2302 */
2303 void addCont(Chain c) {
2304 cont = Code.mergeChains(c, cont);
2305 }
2306 }
2307 }
