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src/share/classes/com/sun/tools/javac/jvm/Gen.java@7375d4979bd3
src/share/classes/com/sun/tools/javac/jvm/Gen.java
Mon, 14 Nov 2011 15:11:10 -0800
- author
- ksrini
- date
- Mon, 14 Nov 2011 15:11:10 -0800
- changeset 1138
- 7375d4979bd3
- parent 1127
- ca49d50318dc
- child 1157
- 3809292620c9
- permissions
- -rw-r--r--
7106166: (javac) re-factor EndPos parser
Reviewed-by: jjg
1 /*
2 * Copyright (c) 1999, 2011, 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 */
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.parser.EndPosTable;
41 import com.sun.tools.javac.tree.JCTree.*;
43 import static com.sun.tools.javac.code.Flags.*;
44 import static com.sun.tools.javac.code.Kinds.*;
45 import static com.sun.tools.javac.code.TypeTags.*;
46 import static com.sun.tools.javac.jvm.ByteCodes.*;
47 import static com.sun.tools.javac.jvm.CRTFlags.*;
48 import static com.sun.tools.javac.main.OptionName.*;
49 import static com.sun.tools.javac.tree.JCTree.Tag.*;
50 import static com.sun.tools.javac.tree.JCTree.Tag.BLOCK;
52 /** This pass maps flat Java (i.e. without inner classes) to bytecodes.
53 *
54 * <p><b>This is NOT part of any supported API.
55 * If you write code that depends on this, you do so at your own risk.
56 * This code and its internal interfaces are subject to change or
57 * deletion without notice.</b>
58 */
59 public class Gen extends JCTree.Visitor {
60 protected static final Context.Key<Gen> genKey =
61 new Context.Key<Gen>();
63 private final Log log;
64 private final Symtab syms;
65 private final Check chk;
66 private final Resolve rs;
67 private final TreeMaker make;
68 private final Names names;
69 private final Target target;
70 private final Type stringBufferType;
71 private final Map<Type,Symbol> stringBufferAppend;
72 private Name accessDollar;
73 private final Types types;
75 /** Switch: GJ mode?
76 */
77 private final boolean allowGenerics;
79 /** Set when Miranda method stubs are to be generated. */
80 private final boolean generateIproxies;
82 /** Format of stackmap tables to be generated. */
83 private final Code.StackMapFormat stackMap;
85 /** A type that serves as the expected type for all method expressions.
86 */
87 private final Type methodType;
89 public static Gen instance(Context context) {
90 Gen instance = context.get(genKey);
91 if (instance == null)
92 instance = new Gen(context);
93 return instance;
94 }
96 protected Gen(Context context) {
97 context.put(genKey, this);
99 names = Names.instance(context);
100 log = Log.instance(context);
101 syms = Symtab.instance(context);
102 chk = Check.instance(context);
103 rs = Resolve.instance(context);
104 make = TreeMaker.instance(context);
105 target = Target.instance(context);
106 types = Types.instance(context);
107 methodType = new MethodType(null, null, null, syms.methodClass);
108 allowGenerics = Source.instance(context).allowGenerics();
109 stringBufferType = target.useStringBuilder()
110 ? syms.stringBuilderType
111 : syms.stringBufferType;
112 stringBufferAppend = new HashMap<Type,Symbol>();
113 accessDollar = names.
114 fromString("access" + target.syntheticNameChar());
116 Options options = Options.instance(context);
117 lineDebugInfo =
118 options.isUnset(G_CUSTOM) ||
119 options.isSet(G_CUSTOM, "lines");
120 varDebugInfo =
121 options.isUnset(G_CUSTOM)
122 ? options.isSet(G)
123 : options.isSet(G_CUSTOM, "vars");
124 genCrt = options.isSet(XJCOV);
125 debugCode = options.isSet("debugcode");
126 allowInvokedynamic = target.hasInvokedynamic() || options.isSet("invokedynamic");
128 generateIproxies =
129 target.requiresIproxy() ||
130 options.isSet("miranda");
132 if (target.generateStackMapTable()) {
133 // ignore cldc because we cannot have both stackmap formats
134 this.stackMap = StackMapFormat.JSR202;
135 } else {
136 if (target.generateCLDCStackmap()) {
137 this.stackMap = StackMapFormat.CLDC;
138 } else {
139 this.stackMap = StackMapFormat.NONE;
140 }
141 }
143 // by default, avoid jsr's for simple finalizers
144 int setjsrlimit = 50;
145 String jsrlimitString = options.get("jsrlimit");
146 if (jsrlimitString != null) {
147 try {
148 setjsrlimit = Integer.parseInt(jsrlimitString);
149 } catch (NumberFormatException ex) {
150 // ignore ill-formed numbers for jsrlimit
151 }
152 }
153 this.jsrlimit = setjsrlimit;
154 this.useJsrLocally = false; // reset in visitTry
155 }
157 /** Switches
158 */
159 private final boolean lineDebugInfo;
160 private final boolean varDebugInfo;
161 private final boolean genCrt;
162 private final boolean debugCode;
163 private final boolean allowInvokedynamic;
165 /** Default limit of (approximate) size of finalizer to inline.
166 * Zero means always use jsr. 100 or greater means never use
167 * jsr.
168 */
169 private final int jsrlimit;
171 /** True if jsr is used.
172 */
173 private boolean useJsrLocally;
175 /* Constant pool, reset by genClass.
176 */
177 private Pool pool = new Pool();
179 /** Code buffer, set by genMethod.
180 */
181 private Code code;
183 /** Items structure, set by genMethod.
184 */
185 private Items items;
187 /** Environment for symbol lookup, set by genClass
188 */
189 private Env<AttrContext> attrEnv;
191 /** The top level tree.
192 */
193 private JCCompilationUnit toplevel;
195 /** The number of code-gen errors in this class.
196 */
197 private int nerrs = 0;
199 /** An object containing mappings of syntax trees to their
200 * ending source positions.
201 */
202 EndPosTable endPosTable;
204 /** Generate code to load an integer constant.
205 * @param n The integer to be loaded.
206 */
207 void loadIntConst(int n) {
208 items.makeImmediateItem(syms.intType, n).load();
209 }
211 /** The opcode that loads a zero constant of a given type code.
212 * @param tc The given type code (@see ByteCode).
213 */
214 public static int zero(int tc) {
215 switch(tc) {
216 case INTcode: case BYTEcode: case SHORTcode: case CHARcode:
217 return iconst_0;
218 case LONGcode:
219 return lconst_0;
220 case FLOATcode:
221 return fconst_0;
222 case DOUBLEcode:
223 return dconst_0;
224 default:
225 throw new AssertionError("zero");
226 }
227 }
229 /** The opcode that loads a one constant of a given type code.
230 * @param tc The given type code (@see ByteCode).
231 */
232 public static int one(int tc) {
233 return zero(tc) + 1;
234 }
236 /** Generate code to load -1 of the given type code (either int or long).
237 * @param tc The given type code (@see ByteCode).
238 */
239 void emitMinusOne(int tc) {
240 if (tc == LONGcode) {
241 items.makeImmediateItem(syms.longType, new Long(-1)).load();
242 } else {
243 code.emitop0(iconst_m1);
244 }
245 }
247 /** Construct a symbol to reflect the qualifying type that should
248 * appear in the byte code as per JLS 13.1.
249 *
250 * For target >= 1.2: Clone a method with the qualifier as owner (except
251 * for those cases where we need to work around VM bugs).
252 *
253 * For target <= 1.1: If qualified variable or method is defined in a
254 * non-accessible class, clone it with the qualifier class as owner.
255 *
256 * @param sym The accessed symbol
257 * @param site The qualifier's type.
258 */
259 Symbol binaryQualifier(Symbol sym, Type site) {
261 if (site.tag == ARRAY) {
262 if (sym == syms.lengthVar ||
263 sym.owner != syms.arrayClass)
264 return sym;
265 // array clone can be qualified by the array type in later targets
266 Symbol qualifier = target.arrayBinaryCompatibility()
267 ? new ClassSymbol(Flags.PUBLIC, site.tsym.name,
268 site, syms.noSymbol)
269 : syms.objectType.tsym;
270 return sym.clone(qualifier);
271 }
273 if (sym.owner == site.tsym ||
274 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) {
275 return sym;
276 }
277 if (!target.obeyBinaryCompatibility())
278 return rs.isAccessible(attrEnv, (TypeSymbol)sym.owner)
279 ? sym
280 : sym.clone(site.tsym);
282 if (!target.interfaceFieldsBinaryCompatibility()) {
283 if ((sym.owner.flags() & INTERFACE) != 0 && sym.kind == VAR)
284 return sym;
285 }
287 // leave alone methods inherited from Object
288 // JLS 13.1.
289 if (sym.owner == syms.objectType.tsym)
290 return sym;
292 if (!target.interfaceObjectOverridesBinaryCompatibility()) {
293 if ((sym.owner.flags() & INTERFACE) != 0 &&
294 syms.objectType.tsym.members().lookup(sym.name).scope != null)
295 return sym;
296 }
298 return sym.clone(site.tsym);
299 }
301 /** Insert a reference to given type in the constant pool,
302 * checking for an array with too many dimensions;
303 * return the reference's index.
304 * @param type The type for which a reference is inserted.
305 */
306 int makeRef(DiagnosticPosition pos, Type type) {
307 checkDimension(pos, type);
308 return pool.put(type.tag == CLASS ? (Object)type.tsym : (Object)type);
309 }
311 /** Check if the given type is an array with too many dimensions.
312 */
313 private void checkDimension(DiagnosticPosition pos, Type t) {
314 switch (t.tag) {
315 case METHOD:
316 checkDimension(pos, t.getReturnType());
317 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail)
318 checkDimension(pos, args.head);
319 break;
320 case ARRAY:
321 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) {
322 log.error(pos, "limit.dimensions");
323 nerrs++;
324 }
325 break;
326 default:
327 break;
328 }
329 }
331 /** Create a tempory variable.
332 * @param type The variable's type.
333 */
334 LocalItem makeTemp(Type type) {
335 VarSymbol v = new VarSymbol(Flags.SYNTHETIC,
336 names.empty,
337 type,
338 env.enclMethod.sym);
339 code.newLocal(v);
340 return items.makeLocalItem(v);
341 }
343 /** Generate code to call a non-private method or constructor.
344 * @param pos Position to be used for error reporting.
345 * @param site The type of which the method is a member.
346 * @param name The method's name.
347 * @param argtypes The method's argument types.
348 * @param isStatic A flag that indicates whether we call a
349 * static or instance method.
350 */
351 void callMethod(DiagnosticPosition pos,
352 Type site, Name name, List<Type> argtypes,
353 boolean isStatic) {
354 Symbol msym = rs.
355 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null);
356 if (isStatic) items.makeStaticItem(msym).invoke();
357 else items.makeMemberItem(msym, name == names.init).invoke();
358 }
360 /** Is the given method definition an access method
361 * resulting from a qualified super? This is signified by an odd
362 * access code.
363 */
364 private boolean isAccessSuper(JCMethodDecl enclMethod) {
365 return
366 (enclMethod.mods.flags & SYNTHETIC) != 0 &&
367 isOddAccessName(enclMethod.name);
368 }
370 /** Does given name start with "access$" and end in an odd digit?
371 */
372 private boolean isOddAccessName(Name name) {
373 return
374 name.startsWith(accessDollar) &&
375 (name.getByteAt(name.getByteLength() - 1) & 1) == 1;
376 }
378 /* ************************************************************************
379 * Non-local exits
380 *************************************************************************/
382 /** Generate code to invoke the finalizer associated with given
383 * environment.
384 * Any calls to finalizers are appended to the environments `cont' chain.
385 * Mark beginning of gap in catch all range for finalizer.
386 */
387 void genFinalizer(Env<GenContext> env) {
388 if (code.isAlive() && env.info.finalize != null)
389 env.info.finalize.gen();
390 }
392 /** Generate code to call all finalizers of structures aborted by
393 * a non-local
394 * exit. Return target environment of the non-local exit.
395 * @param target The tree representing the structure that's aborted
396 * @param env The environment current at the non-local exit.
397 */
398 Env<GenContext> unwind(JCTree target, Env<GenContext> env) {
399 Env<GenContext> env1 = env;
400 while (true) {
401 genFinalizer(env1);
402 if (env1.tree == target) break;
403 env1 = env1.next;
404 }
405 return env1;
406 }
408 /** Mark end of gap in catch-all range for finalizer.
409 * @param env the environment which might contain the finalizer
410 * (if it does, env.info.gaps != null).
411 */
412 void endFinalizerGap(Env<GenContext> env) {
413 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1)
414 env.info.gaps.append(code.curPc());
415 }
417 /** Mark end of all gaps in catch-all ranges for finalizers of environments
418 * lying between, and including to two environments.
419 * @param from the most deeply nested environment to mark
420 * @param to the least deeply nested environment to mark
421 */
422 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) {
423 Env<GenContext> last = null;
424 while (last != to) {
425 endFinalizerGap(from);
426 last = from;
427 from = from.next;
428 }
429 }
431 /** Do any of the structures aborted by a non-local exit have
432 * finalizers that require an empty stack?
433 * @param target The tree representing the structure that's aborted
434 * @param env The environment current at the non-local exit.
435 */
436 boolean hasFinally(JCTree target, Env<GenContext> env) {
437 while (env.tree != target) {
438 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer())
439 return true;
440 env = env.next;
441 }
442 return false;
443 }
445 /* ************************************************************************
446 * Normalizing class-members.
447 *************************************************************************/
449 /** Distribute member initializer code into constructors and <clinit>
450 * method.
451 * @param defs The list of class member declarations.
452 * @param c The enclosing class.
453 */
454 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) {
455 ListBuffer<JCStatement> initCode = new ListBuffer<JCStatement>();
456 ListBuffer<JCStatement> clinitCode = new ListBuffer<JCStatement>();
457 ListBuffer<JCTree> methodDefs = new ListBuffer<JCTree>();
458 // Sort definitions into three listbuffers:
459 // - initCode for instance initializers
460 // - clinitCode for class initializers
461 // - methodDefs for method definitions
462 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
463 JCTree def = l.head;
464 switch (def.getTag()) {
465 case BLOCK:
466 JCBlock block = (JCBlock)def;
467 if ((block.flags & STATIC) != 0)
468 clinitCode.append(block);
469 else
470 initCode.append(block);
471 break;
472 case METHODDEF:
473 methodDefs.append(def);
474 break;
475 case VARDEF:
476 JCVariableDecl vdef = (JCVariableDecl) def;
477 VarSymbol sym = vdef.sym;
478 checkDimension(vdef.pos(), sym.type);
479 if (vdef.init != null) {
480 if ((sym.flags() & STATIC) == 0) {
481 // Always initialize instance variables.
482 JCStatement init = make.at(vdef.pos()).
483 Assignment(sym, vdef.init);
484 initCode.append(init);
485 endPosTable.replaceTree(vdef, init);
486 } else if (sym.getConstValue() == null) {
487 // Initialize class (static) variables only if
488 // they are not compile-time constants.
489 JCStatement init = make.at(vdef.pos).
490 Assignment(sym, vdef.init);
491 clinitCode.append(init);
492 endPosTable.replaceTree(vdef, init);
493 } else {
494 checkStringConstant(vdef.init.pos(), sym.getConstValue());
495 }
496 }
497 break;
498 default:
499 Assert.error();
500 }
501 }
502 // Insert any instance initializers into all constructors.
503 if (initCode.length() != 0) {
504 List<JCStatement> inits = initCode.toList();
505 for (JCTree t : methodDefs) {
506 normalizeMethod((JCMethodDecl)t, inits);
507 }
508 }
509 // If there are class initializers, create a <clinit> method
510 // that contains them as its body.
511 if (clinitCode.length() != 0) {
512 MethodSymbol clinit = new MethodSymbol(
513 STATIC, names.clinit,
514 new MethodType(
515 List.<Type>nil(), syms.voidType,
516 List.<Type>nil(), syms.methodClass),
517 c);
518 c.members().enter(clinit);
519 List<JCStatement> clinitStats = clinitCode.toList();
520 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
521 block.endpos = TreeInfo.endPos(clinitStats.last());
522 methodDefs.append(make.MethodDef(clinit, block));
523 }
524 // Return all method definitions.
525 return methodDefs.toList();
526 }
528 /** Check a constant value and report if it is a string that is
529 * too large.
530 */
531 private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
532 if (nerrs != 0 || // only complain about a long string once
533 constValue == null ||
534 !(constValue instanceof String) ||
535 ((String)constValue).length() < Pool.MAX_STRING_LENGTH)
536 return;
537 log.error(pos, "limit.string");
538 nerrs++;
539 }
541 /** Insert instance initializer code into initial constructor.
542 * @param md The tree potentially representing a
543 * constructor's definition.
544 * @param initCode The list of instance initializer statements.
545 */
546 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode) {
547 if (md.name == names.init && TreeInfo.isInitialConstructor(md)) {
548 // We are seeing a constructor that does not call another
549 // constructor of the same class.
550 List<JCStatement> stats = md.body.stats;
551 ListBuffer<JCStatement> newstats = new ListBuffer<JCStatement>();
553 if (stats.nonEmpty()) {
554 // Copy initializers of synthetic variables generated in
555 // the translation of inner classes.
556 while (TreeInfo.isSyntheticInit(stats.head)) {
557 newstats.append(stats.head);
558 stats = stats.tail;
559 }
560 // Copy superclass constructor call
561 newstats.append(stats.head);
562 stats = stats.tail;
563 // Copy remaining synthetic initializers.
564 while (stats.nonEmpty() &&
565 TreeInfo.isSyntheticInit(stats.head)) {
566 newstats.append(stats.head);
567 stats = stats.tail;
568 }
569 // Now insert the initializer code.
570 newstats.appendList(initCode);
571 // And copy all remaining statements.
572 while (stats.nonEmpty()) {
573 newstats.append(stats.head);
574 stats = stats.tail;
575 }
576 }
577 md.body.stats = newstats.toList();
578 if (md.body.endpos == Position.NOPOS)
579 md.body.endpos = TreeInfo.endPos(md.body.stats.last());
580 }
581 }
583 /* ********************************************************************
584 * Adding miranda methods
585 *********************************************************************/
587 /** Add abstract methods for all methods defined in one of
588 * the interfaces of a given class,
589 * provided they are not already implemented in the class.
590 *
591 * @param c The class whose interfaces are searched for methods
592 * for which Miranda methods should be added.
593 */
594 void implementInterfaceMethods(ClassSymbol c) {
595 implementInterfaceMethods(c, c);
596 }
598 /** Add abstract methods for all methods defined in one of
599 * the interfaces of a given class,
600 * provided they are not already implemented in the class.
601 *
602 * @param c The class whose interfaces are searched for methods
603 * for which Miranda methods should be added.
604 * @param site The class in which a definition may be needed.
605 */
606 void implementInterfaceMethods(ClassSymbol c, ClassSymbol site) {
607 for (List<Type> l = types.interfaces(c.type); l.nonEmpty(); l = l.tail) {
608 ClassSymbol i = (ClassSymbol)l.head.tsym;
609 for (Scope.Entry e = i.members().elems;
610 e != null;
611 e = e.sibling)
612 {
613 if (e.sym.kind == MTH && (e.sym.flags() & STATIC) == 0)
614 {
615 MethodSymbol absMeth = (MethodSymbol)e.sym;
616 MethodSymbol implMeth = absMeth.binaryImplementation(site, types);
617 if (implMeth == null)
618 addAbstractMethod(site, absMeth);
619 else if ((implMeth.flags() & IPROXY) != 0)
620 adjustAbstractMethod(site, implMeth, absMeth);
621 }
622 }
623 implementInterfaceMethods(i, site);
624 }
625 }
627 /** Add an abstract methods to a class
628 * which implicitly implements a method defined in some interface
629 * implemented by the class. These methods are called "Miranda methods".
630 * Enter the newly created method into its enclosing class scope.
631 * Note that it is not entered into the class tree, as the emitter
632 * doesn't need to see it there to emit an abstract method.
633 *
634 * @param c The class to which the Miranda method is added.
635 * @param m The interface method symbol for which a Miranda method
636 * is added.
637 */
638 private void addAbstractMethod(ClassSymbol c,
639 MethodSymbol m) {
640 MethodSymbol absMeth = new MethodSymbol(
641 m.flags() | IPROXY | SYNTHETIC, m.name,
642 m.type, // was c.type.memberType(m), but now only !generics supported
643 c);
644 c.members().enter(absMeth); // add to symbol table
645 }
647 private void adjustAbstractMethod(ClassSymbol c,
648 MethodSymbol pm,
649 MethodSymbol im) {
650 MethodType pmt = (MethodType)pm.type;
651 Type imt = types.memberType(c.type, im);
652 pmt.thrown = chk.intersect(pmt.getThrownTypes(), imt.getThrownTypes());
653 }
655 /* ************************************************************************
656 * Traversal methods
657 *************************************************************************/
659 /** Visitor argument: The current environment.
660 */
661 Env<GenContext> env;
663 /** Visitor argument: The expected type (prototype).
664 */
665 Type pt;
667 /** Visitor result: The item representing the computed value.
668 */
669 Item result;
671 /** Visitor method: generate code for a definition, catching and reporting
672 * any completion failures.
673 * @param tree The definition to be visited.
674 * @param env The environment current at the definition.
675 */
676 public void genDef(JCTree tree, Env<GenContext> env) {
677 Env<GenContext> prevEnv = this.env;
678 try {
679 this.env = env;
680 tree.accept(this);
681 } catch (CompletionFailure ex) {
682 chk.completionError(tree.pos(), ex);
683 } finally {
684 this.env = prevEnv;
685 }
686 }
688 /** Derived visitor method: check whether CharacterRangeTable
689 * should be emitted, if so, put a new entry into CRTable
690 * and call method to generate bytecode.
691 * If not, just call method to generate bytecode.
692 * @see #genStat(Tree, Env)
693 *
694 * @param tree The tree to be visited.
695 * @param env The environment to use.
696 * @param crtFlags The CharacterRangeTable flags
697 * indicating type of the entry.
698 */
699 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
700 if (!genCrt) {
701 genStat(tree, env);
702 return;
703 }
704 int startpc = code.curPc();
705 genStat(tree, env);
706 if (tree.hasTag(BLOCK)) crtFlags |= CRT_BLOCK;
707 code.crt.put(tree, crtFlags, startpc, code.curPc());
708 }
710 /** Derived visitor method: generate code for a statement.
711 */
712 public void genStat(JCTree tree, Env<GenContext> env) {
713 if (code.isAlive()) {
714 code.statBegin(tree.pos);
715 genDef(tree, env);
716 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) {
717 // variables whose declarations are in a switch
718 // can be used even if the decl is unreachable.
719 code.newLocal(((JCVariableDecl) tree).sym);
720 }
721 }
723 /** Derived visitor method: check whether CharacterRangeTable
724 * should be emitted, if so, put a new entry into CRTable
725 * and call method to generate bytecode.
726 * If not, just call method to generate bytecode.
727 * @see #genStats(List, Env)
728 *
729 * @param trees The list of trees to be visited.
730 * @param env The environment to use.
731 * @param crtFlags The CharacterRangeTable flags
732 * indicating type of the entry.
733 */
734 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
735 if (!genCrt) {
736 genStats(trees, env);
737 return;
738 }
739 if (trees.length() == 1) { // mark one statement with the flags
740 genStat(trees.head, env, crtFlags | CRT_STATEMENT);
741 } else {
742 int startpc = code.curPc();
743 genStats(trees, env);
744 code.crt.put(trees, crtFlags, startpc, code.curPc());
745 }
746 }
748 /** Derived visitor method: generate code for a list of statements.
749 */
750 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) {
751 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
752 genStat(l.head, env, CRT_STATEMENT);
753 }
755 /** Derived visitor method: check whether CharacterRangeTable
756 * should be emitted, if so, put a new entry into CRTable
757 * and call method to generate bytecode.
758 * If not, just call method to generate bytecode.
759 * @see #genCond(Tree,boolean)
760 *
761 * @param tree The tree to be visited.
762 * @param crtFlags The CharacterRangeTable flags
763 * indicating type of the entry.
764 */
765 public CondItem genCond(JCTree tree, int crtFlags) {
766 if (!genCrt) return genCond(tree, false);
767 int startpc = code.curPc();
768 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
769 code.crt.put(tree, crtFlags, startpc, code.curPc());
770 return item;
771 }
773 /** Derived visitor method: generate code for a boolean
774 * expression in a control-flow context.
775 * @param _tree The expression to be visited.
776 * @param markBranches The flag to indicate that the condition is
777 * a flow controller so produced conditions
778 * should contain a proper tree to generate
779 * CharacterRangeTable branches for them.
780 */
781 public CondItem genCond(JCTree _tree, boolean markBranches) {
782 JCTree inner_tree = TreeInfo.skipParens(_tree);
783 if (inner_tree.hasTag(CONDEXPR)) {
784 JCConditional tree = (JCConditional)inner_tree;
785 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
786 if (cond.isTrue()) {
787 code.resolve(cond.trueJumps);
788 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
789 if (markBranches) result.tree = tree.truepart;
790 return result;
791 }
792 if (cond.isFalse()) {
793 code.resolve(cond.falseJumps);
794 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
795 if (markBranches) result.tree = tree.falsepart;
796 return result;
797 }
798 Chain secondJumps = cond.jumpFalse();
799 code.resolve(cond.trueJumps);
800 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
801 if (markBranches) first.tree = tree.truepart;
802 Chain falseJumps = first.jumpFalse();
803 code.resolve(first.trueJumps);
804 Chain trueJumps = code.branch(goto_);
805 code.resolve(secondJumps);
806 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
807 CondItem result = items.makeCondItem(second.opcode,
808 Code.mergeChains(trueJumps, second.trueJumps),
809 Code.mergeChains(falseJumps, second.falseJumps));
810 if (markBranches) result.tree = tree.falsepart;
811 return result;
812 } else {
813 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
814 if (markBranches) result.tree = _tree;
815 return result;
816 }
817 }
819 /** Visitor method: generate code for an expression, catching and reporting
820 * any completion failures.
821 * @param tree The expression to be visited.
822 * @param pt The expression's expected type (proto-type).
823 */
824 public Item genExpr(JCTree tree, Type pt) {
825 Type prevPt = this.pt;
826 try {
827 if (tree.type.constValue() != null) {
828 // Short circuit any expressions which are constants
829 checkStringConstant(tree.pos(), tree.type.constValue());
830 result = items.makeImmediateItem(tree.type, tree.type.constValue());
831 } else {
832 this.pt = pt;
833 tree.accept(this);
834 }
835 return result.coerce(pt);
836 } catch (CompletionFailure ex) {
837 chk.completionError(tree.pos(), ex);
838 code.state.stacksize = 1;
839 return items.makeStackItem(pt);
840 } finally {
841 this.pt = prevPt;
842 }
843 }
845 /** Derived visitor method: generate code for a list of method arguments.
846 * @param trees The argument expressions to be visited.
847 * @param pts The expression's expected types (i.e. the formal parameter
848 * types of the invoked method).
849 */
850 public void genArgs(List<JCExpression> trees, List<Type> pts) {
851 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
852 genExpr(l.head, pts.head).load();
853 pts = pts.tail;
854 }
855 // require lists be of same length
856 Assert.check(pts.isEmpty());
857 }
859 /* ************************************************************************
860 * Visitor methods for statements and definitions
861 *************************************************************************/
863 /** Thrown when the byte code size exceeds limit.
864 */
865 public static class CodeSizeOverflow extends RuntimeException {
866 private static final long serialVersionUID = 0;
867 public CodeSizeOverflow() {}
868 }
870 public void visitMethodDef(JCMethodDecl tree) {
871 // Create a new local environment that points pack at method
872 // definition.
873 Env<GenContext> localEnv = env.dup(tree);
874 localEnv.enclMethod = tree;
876 // The expected type of every return statement in this method
877 // is the method's return type.
878 this.pt = tree.sym.erasure(types).getReturnType();
880 checkDimension(tree.pos(), tree.sym.erasure(types));
881 genMethod(tree, localEnv, false);
882 }
883 //where
884 /** Generate code for a method.
885 * @param tree The tree representing the method definition.
886 * @param env The environment current for the method body.
887 * @param fatcode A flag that indicates whether all jumps are
888 * within 32K. We first invoke this method under
889 * the assumption that fatcode == false, i.e. all
890 * jumps are within 32K. If this fails, fatcode
891 * is set to true and we try again.
892 */
893 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
894 MethodSymbol meth = tree.sym;
895 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
896 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) +
897 (((tree.mods.flags & STATIC) == 0 || meth.isConstructor()) ? 1 : 0) >
898 ClassFile.MAX_PARAMETERS) {
899 log.error(tree.pos(), "limit.parameters");
900 nerrs++;
901 }
903 else if (tree.body != null) {
904 // Create a new code structure and initialize it.
905 int startpcCrt = initCode(tree, env, fatcode);
907 try {
908 genStat(tree.body, env);
909 } catch (CodeSizeOverflow e) {
910 // Failed due to code limit, try again with jsr/ret
911 startpcCrt = initCode(tree, env, fatcode);
912 genStat(tree.body, env);
913 }
915 if (code.state.stacksize != 0) {
916 log.error(tree.body.pos(), "stack.sim.error", tree);
917 throw new AssertionError();
918 }
920 // If last statement could complete normally, insert a
921 // return at the end.
922 if (code.isAlive()) {
923 code.statBegin(TreeInfo.endPos(tree.body));
924 if (env.enclMethod == null ||
925 env.enclMethod.sym.type.getReturnType().tag == VOID) {
926 code.emitop0(return_);
927 } else {
928 // sometime dead code seems alive (4415991);
929 // generate a small loop instead
930 int startpc = code.entryPoint();
931 CondItem c = items.makeCondItem(goto_);
932 code.resolve(c.jumpTrue(), startpc);
933 }
934 }
935 if (genCrt)
936 code.crt.put(tree.body,
937 CRT_BLOCK,
938 startpcCrt,
939 code.curPc());
941 code.endScopes(0);
943 // If we exceeded limits, panic
944 if (code.checkLimits(tree.pos(), log)) {
945 nerrs++;
946 return;
947 }
949 // If we generated short code but got a long jump, do it again
950 // with fatCode = true.
951 if (!fatcode && code.fatcode) genMethod(tree, env, true);
953 // Clean up
954 if(stackMap == StackMapFormat.JSR202) {
955 code.lastFrame = null;
956 code.frameBeforeLast = null;
957 }
959 //compress exception table
960 code.compressCatchTable();
961 }
962 }
964 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
965 MethodSymbol meth = tree.sym;
967 // Create a new code structure.
968 meth.code = code = new Code(meth,
969 fatcode,
970 lineDebugInfo ? toplevel.lineMap : null,
971 varDebugInfo,
972 stackMap,
973 debugCode,
974 genCrt ? new CRTable(tree, env.toplevel.endPositions)
975 : null,
976 syms,
977 types,
978 pool);
979 items = new Items(pool, code, syms, types);
980 if (code.debugCode)
981 System.err.println(meth + " for body " + tree);
983 // If method is not static, create a new local variable address
984 // for `this'.
985 if ((tree.mods.flags & STATIC) == 0) {
986 Type selfType = meth.owner.type;
987 if (meth.isConstructor() && selfType != syms.objectType)
988 selfType = UninitializedType.uninitializedThis(selfType);
989 code.setDefined(
990 code.newLocal(
991 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
992 }
994 // Mark all parameters as defined from the beginning of
995 // the method.
996 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
997 checkDimension(l.head.pos(), l.head.sym.type);
998 code.setDefined(code.newLocal(l.head.sym));
999 }
1001 // Get ready to generate code for method body.
1002 int startpcCrt = genCrt ? code.curPc() : 0;
1003 code.entryPoint();
1005 // Suppress initial stackmap
1006 code.pendingStackMap = false;
1008 return startpcCrt;
1009 }
1011 public void visitVarDef(JCVariableDecl tree) {
1012 VarSymbol v = tree.sym;
1013 code.newLocal(v);
1014 if (tree.init != null) {
1015 checkStringConstant(tree.init.pos(), v.getConstValue());
1016 if (v.getConstValue() == null || varDebugInfo) {
1017 genExpr(tree.init, v.erasure(types)).load();
1018 items.makeLocalItem(v).store();
1019 }
1020 }
1021 checkDimension(tree.pos(), v.type);
1022 }
1024 public void visitSkip(JCSkip tree) {
1025 }
1027 public void visitBlock(JCBlock tree) {
1028 int limit = code.nextreg;
1029 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1030 genStats(tree.stats, localEnv);
1031 // End the scope of all block-local variables in variable info.
1032 if (!env.tree.hasTag(METHODDEF)) {
1033 code.statBegin(tree.endpos);
1034 code.endScopes(limit);
1035 code.pendingStatPos = Position.NOPOS;
1036 }
1037 }
1039 public void visitDoLoop(JCDoWhileLoop tree) {
1040 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), false);
1041 }
1043 public void visitWhileLoop(JCWhileLoop tree) {
1044 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), true);
1045 }
1047 public void visitForLoop(JCForLoop tree) {
1048 int limit = code.nextreg;
1049 genStats(tree.init, env);
1050 genLoop(tree, tree.body, tree.cond, tree.step, true);
1051 code.endScopes(limit);
1052 }
1053 //where
1054 /** Generate code for a loop.
1055 * @param loop The tree representing the loop.
1056 * @param body The loop's body.
1057 * @param cond The loop's controling condition.
1058 * @param step "Step" statements to be inserted at end of
1059 * each iteration.
1060 * @param testFirst True if the loop test belongs before the body.
1061 */
1062 private void genLoop(JCStatement loop,
1063 JCStatement body,
1064 JCExpression cond,
1065 List<JCExpressionStatement> step,
1066 boolean testFirst) {
1067 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1068 int startpc = code.entryPoint();
1069 if (testFirst) {
1070 CondItem c;
1071 if (cond != null) {
1072 code.statBegin(cond.pos);
1073 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1074 } else {
1075 c = items.makeCondItem(goto_);
1076 }
1077 Chain loopDone = c.jumpFalse();
1078 code.resolve(c.trueJumps);
1079 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1080 code.resolve(loopEnv.info.cont);
1081 genStats(step, loopEnv);
1082 code.resolve(code.branch(goto_), startpc);
1083 code.resolve(loopDone);
1084 } else {
1085 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1086 code.resolve(loopEnv.info.cont);
1087 genStats(step, loopEnv);
1088 CondItem c;
1089 if (cond != null) {
1090 code.statBegin(cond.pos);
1091 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1092 } else {
1093 c = items.makeCondItem(goto_);
1094 }
1095 code.resolve(c.jumpTrue(), startpc);
1096 code.resolve(c.falseJumps);
1097 }
1098 code.resolve(loopEnv.info.exit);
1099 }
1101 public void visitForeachLoop(JCEnhancedForLoop tree) {
1102 throw new AssertionError(); // should have been removed by Lower.
1103 }
1105 public void visitLabelled(JCLabeledStatement tree) {
1106 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1107 genStat(tree.body, localEnv, CRT_STATEMENT);
1108 code.resolve(localEnv.info.exit);
1109 }
1111 public void visitSwitch(JCSwitch tree) {
1112 int limit = code.nextreg;
1113 Assert.check(tree.selector.type.tag != CLASS);
1114 int startpcCrt = genCrt ? code.curPc() : 0;
1115 Item sel = genExpr(tree.selector, syms.intType);
1116 List<JCCase> cases = tree.cases;
1117 if (cases.isEmpty()) {
1118 // We are seeing: switch <sel> {}
1119 sel.load().drop();
1120 if (genCrt)
1121 code.crt.put(TreeInfo.skipParens(tree.selector),
1122 CRT_FLOW_CONTROLLER, startpcCrt, code.curPc());
1123 } else {
1124 // We are seeing a nonempty switch.
1125 sel.load();
1126 if (genCrt)
1127 code.crt.put(TreeInfo.skipParens(tree.selector),
1128 CRT_FLOW_CONTROLLER, startpcCrt, code.curPc());
1129 Env<GenContext> switchEnv = env.dup(tree, new GenContext());
1130 switchEnv.info.isSwitch = true;
1132 // Compute number of labels and minimum and maximum label values.
1133 // For each case, store its label in an array.
1134 int lo = Integer.MAX_VALUE; // minimum label.
1135 int hi = Integer.MIN_VALUE; // maximum label.
1136 int nlabels = 0; // number of labels.
1138 int[] labels = new int[cases.length()]; // the label array.
1139 int defaultIndex = -1; // the index of the default clause.
1141 List<JCCase> l = cases;
1142 for (int i = 0; i < labels.length; i++) {
1143 if (l.head.pat != null) {
1144 int val = ((Number)l.head.pat.type.constValue()).intValue();
1145 labels[i] = val;
1146 if (val < lo) lo = val;
1147 if (hi < val) hi = val;
1148 nlabels++;
1149 } else {
1150 Assert.check(defaultIndex == -1);
1151 defaultIndex = i;
1152 }
1153 l = l.tail;
1154 }
1156 // Determine whether to issue a tableswitch or a lookupswitch
1157 // instruction.
1158 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1159 long table_time_cost = 3; // comparisons
1160 long lookup_space_cost = 3 + 2 * (long) nlabels;
1161 long lookup_time_cost = nlabels;
1162 int opcode =
1163 nlabels > 0 &&
1164 table_space_cost + 3 * table_time_cost <=
1165 lookup_space_cost + 3 * lookup_time_cost
1166 ?
1167 tableswitch : lookupswitch;
1169 int startpc = code.curPc(); // the position of the selector operation
1170 code.emitop0(opcode);
1171 code.align(4);
1172 int tableBase = code.curPc(); // the start of the jump table
1173 int[] offsets = null; // a table of offsets for a lookupswitch
1174 code.emit4(-1); // leave space for default offset
1175 if (opcode == tableswitch) {
1176 code.emit4(lo); // minimum label
1177 code.emit4(hi); // maximum label
1178 for (long i = lo; i <= hi; i++) { // leave space for jump table
1179 code.emit4(-1);
1180 }
1181 } else {
1182 code.emit4(nlabels); // number of labels
1183 for (int i = 0; i < nlabels; i++) {
1184 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1185 }
1186 offsets = new int[labels.length];
1187 }
1188 Code.State stateSwitch = code.state.dup();
1189 code.markDead();
1191 // For each case do:
1192 l = cases;
1193 for (int i = 0; i < labels.length; i++) {
1194 JCCase c = l.head;
1195 l = l.tail;
1197 int pc = code.entryPoint(stateSwitch);
1198 // Insert offset directly into code or else into the
1199 // offsets table.
1200 if (i != defaultIndex) {
1201 if (opcode == tableswitch) {
1202 code.put4(
1203 tableBase + 4 * (labels[i] - lo + 3),
1204 pc - startpc);
1205 } else {
1206 offsets[i] = pc - startpc;
1207 }
1208 } else {
1209 code.put4(tableBase, pc - startpc);
1210 }
1212 // Generate code for the statements in this case.
1213 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1214 }
1216 // Resolve all breaks.
1217 code.resolve(switchEnv.info.exit);
1219 // If we have not set the default offset, we do so now.
1220 if (code.get4(tableBase) == -1) {
1221 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1222 }
1224 if (opcode == tableswitch) {
1225 // Let any unfilled slots point to the default case.
1226 int defaultOffset = code.get4(tableBase);
1227 for (long i = lo; i <= hi; i++) {
1228 int t = (int)(tableBase + 4 * (i - lo + 3));
1229 if (code.get4(t) == -1)
1230 code.put4(t, defaultOffset);
1231 }
1232 } else {
1233 // Sort non-default offsets and copy into lookup table.
1234 if (defaultIndex >= 0)
1235 for (int i = defaultIndex; i < labels.length - 1; i++) {
1236 labels[i] = labels[i+1];
1237 offsets[i] = offsets[i+1];
1238 }
1239 if (nlabels > 0)
1240 qsort2(labels, offsets, 0, nlabels - 1);
1241 for (int i = 0; i < nlabels; i++) {
1242 int caseidx = tableBase + 8 * (i + 1);
1243 code.put4(caseidx, labels[i]);
1244 code.put4(caseidx + 4, offsets[i]);
1245 }
1246 }
1247 }
1248 code.endScopes(limit);
1249 }
1250 //where
1251 /** Sort (int) arrays of keys and values
1252 */
1253 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1254 int i = lo;
1255 int j = hi;
1256 int pivot = keys[(i+j)/2];
1257 do {
1258 while (keys[i] < pivot) i++;
1259 while (pivot < keys[j]) j--;
1260 if (i <= j) {
1261 int temp1 = keys[i];
1262 keys[i] = keys[j];
1263 keys[j] = temp1;
1264 int temp2 = values[i];
1265 values[i] = values[j];
1266 values[j] = temp2;
1267 i++;
1268 j--;
1269 }
1270 } while (i <= j);
1271 if (lo < j) qsort2(keys, values, lo, j);
1272 if (i < hi) qsort2(keys, values, i, hi);
1273 }
1275 public void visitSynchronized(JCSynchronized tree) {
1276 int limit = code.nextreg;
1277 // Generate code to evaluate lock and save in temporary variable.
1278 final LocalItem lockVar = makeTemp(syms.objectType);
1279 genExpr(tree.lock, tree.lock.type).load().duplicate();
1280 lockVar.store();
1282 // Generate code to enter monitor.
1283 code.emitop0(monitorenter);
1284 code.state.lock(lockVar.reg);
1286 // Generate code for a try statement with given body, no catch clauses
1287 // in a new environment with the "exit-monitor" operation as finalizer.
1288 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1289 syncEnv.info.finalize = new GenFinalizer() {
1290 void gen() {
1291 genLast();
1292 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1293 syncEnv.info.gaps.append(code.curPc());
1294 }
1295 void genLast() {
1296 if (code.isAlive()) {
1297 lockVar.load();
1298 code.emitop0(monitorexit);
1299 code.state.unlock(lockVar.reg);
1300 }
1301 }
1302 };
1303 syncEnv.info.gaps = new ListBuffer<Integer>();
1304 genTry(tree.body, List.<JCCatch>nil(), syncEnv);
1305 code.endScopes(limit);
1306 }
1308 public void visitTry(final JCTry tree) {
1309 // Generate code for a try statement with given body and catch clauses,
1310 // in a new environment which calls the finally block if there is one.
1311 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1312 final Env<GenContext> oldEnv = env;
1313 if (!useJsrLocally) {
1314 useJsrLocally =
1315 (stackMap == StackMapFormat.NONE) &&
1316 (jsrlimit <= 0 ||
1317 jsrlimit < 100 &&
1318 estimateCodeComplexity(tree.finalizer)>jsrlimit);
1319 }
1320 tryEnv.info.finalize = new GenFinalizer() {
1321 void gen() {
1322 if (useJsrLocally) {
1323 if (tree.finalizer != null) {
1324 Code.State jsrState = code.state.dup();
1325 jsrState.push(Code.jsrReturnValue);
1326 tryEnv.info.cont =
1327 new Chain(code.emitJump(jsr),
1328 tryEnv.info.cont,
1329 jsrState);
1330 }
1331 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1332 tryEnv.info.gaps.append(code.curPc());
1333 } else {
1334 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1335 tryEnv.info.gaps.append(code.curPc());
1336 genLast();
1337 }
1338 }
1339 void genLast() {
1340 if (tree.finalizer != null)
1341 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1342 }
1343 boolean hasFinalizer() {
1344 return tree.finalizer != null;
1345 }
1346 };
1347 tryEnv.info.gaps = new ListBuffer<Integer>();
1348 genTry(tree.body, tree.catchers, tryEnv);
1349 }
1350 //where
1351 /** Generate code for a try or synchronized statement
1352 * @param body The body of the try or synchronized statement.
1353 * @param catchers The lis of catch clauses.
1354 * @param env the environment current for the body.
1355 */
1356 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1357 int limit = code.nextreg;
1358 int startpc = code.curPc();
1359 Code.State stateTry = code.state.dup();
1360 genStat(body, env, CRT_BLOCK);
1361 int endpc = code.curPc();
1362 boolean hasFinalizer =
1363 env.info.finalize != null &&
1364 env.info.finalize.hasFinalizer();
1365 List<Integer> gaps = env.info.gaps.toList();
1366 code.statBegin(TreeInfo.endPos(body));
1367 genFinalizer(env);
1368 code.statBegin(TreeInfo.endPos(env.tree));
1369 Chain exitChain = code.branch(goto_);
1370 endFinalizerGap(env);
1371 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1372 // start off with exception on stack
1373 code.entryPoint(stateTry, l.head.param.sym.type);
1374 genCatch(l.head, env, startpc, endpc, gaps);
1375 genFinalizer(env);
1376 if (hasFinalizer || l.tail.nonEmpty()) {
1377 code.statBegin(TreeInfo.endPos(env.tree));
1378 exitChain = Code.mergeChains(exitChain,
1379 code.branch(goto_));
1380 }
1381 endFinalizerGap(env);
1382 }
1383 if (hasFinalizer) {
1384 // Create a new register segement to avoid allocating
1385 // the same variables in finalizers and other statements.
1386 code.newRegSegment();
1388 // Add a catch-all clause.
1390 // start off with exception on stack
1391 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1393 // Register all exception ranges for catch all clause.
1394 // The range of the catch all clause is from the beginning
1395 // of the try or synchronized block until the present
1396 // code pointer excluding all gaps in the current
1397 // environment's GenContext.
1398 int startseg = startpc;
1399 while (env.info.gaps.nonEmpty()) {
1400 int endseg = env.info.gaps.next().intValue();
1401 registerCatch(body.pos(), startseg, endseg,
1402 catchallpc, 0);
1403 startseg = env.info.gaps.next().intValue();
1404 }
1405 code.statBegin(TreeInfo.finalizerPos(env.tree));
1406 code.markStatBegin();
1408 Item excVar = makeTemp(syms.throwableType);
1409 excVar.store();
1410 genFinalizer(env);
1411 excVar.load();
1412 registerCatch(body.pos(), startseg,
1413 env.info.gaps.next().intValue(),
1414 catchallpc, 0);
1415 code.emitop0(athrow);
1416 code.markDead();
1418 // If there are jsr's to this finalizer, ...
1419 if (env.info.cont != null) {
1420 // Resolve all jsr's.
1421 code.resolve(env.info.cont);
1423 // Mark statement line number
1424 code.statBegin(TreeInfo.finalizerPos(env.tree));
1425 code.markStatBegin();
1427 // Save return address.
1428 LocalItem retVar = makeTemp(syms.throwableType);
1429 retVar.store();
1431 // Generate finalizer code.
1432 env.info.finalize.genLast();
1434 // Return.
1435 code.emitop1w(ret, retVar.reg);
1436 code.markDead();
1437 }
1438 }
1439 // Resolve all breaks.
1440 code.resolve(exitChain);
1442 code.endScopes(limit);
1443 }
1445 /** Generate code for a catch clause.
1446 * @param tree The catch clause.
1447 * @param env The environment current in the enclosing try.
1448 * @param startpc Start pc of try-block.
1449 * @param endpc End pc of try-block.
1450 */
1451 void genCatch(JCCatch tree,
1452 Env<GenContext> env,
1453 int startpc, int endpc,
1454 List<Integer> gaps) {
1455 if (startpc != endpc) {
1456 List<JCExpression> subClauses = TreeInfo.isMultiCatch(tree) ?
1457 ((JCTypeUnion)tree.param.vartype).alternatives :
1458 List.of(tree.param.vartype);
1459 while (gaps.nonEmpty()) {
1460 for (JCExpression subCatch : subClauses) {
1461 int catchType = makeRef(tree.pos(), subCatch.type);
1462 int end = gaps.head.intValue();
1463 registerCatch(tree.pos(),
1464 startpc, end, code.curPc(),
1465 catchType);
1466 }
1467 gaps = gaps.tail;
1468 startpc = gaps.head.intValue();
1469 gaps = gaps.tail;
1470 }
1471 if (startpc < endpc) {
1472 for (JCExpression subCatch : subClauses) {
1473 int catchType = makeRef(tree.pos(), subCatch.type);
1474 registerCatch(tree.pos(),
1475 startpc, endpc, code.curPc(),
1476 catchType);
1477 }
1478 }
1479 VarSymbol exparam = tree.param.sym;
1480 code.statBegin(tree.pos);
1481 code.markStatBegin();
1482 int limit = code.nextreg;
1483 int exlocal = code.newLocal(exparam);
1484 items.makeLocalItem(exparam).store();
1485 code.statBegin(TreeInfo.firstStatPos(tree.body));
1486 genStat(tree.body, env, CRT_BLOCK);
1487 code.endScopes(limit);
1488 code.statBegin(TreeInfo.endPos(tree.body));
1489 }
1490 }
1492 /** Register a catch clause in the "Exceptions" code-attribute.
1493 */
1494 void registerCatch(DiagnosticPosition pos,
1495 int startpc, int endpc,
1496 int handler_pc, int catch_type) {
1497 char startpc1 = (char)startpc;
1498 char endpc1 = (char)endpc;
1499 char handler_pc1 = (char)handler_pc;
1500 if (startpc1 == startpc &&
1501 endpc1 == endpc &&
1502 handler_pc1 == handler_pc) {
1503 code.addCatch(startpc1, endpc1, handler_pc1,
1504 (char)catch_type);
1505 } else {
1506 if (!useJsrLocally && !target.generateStackMapTable()) {
1507 useJsrLocally = true;
1508 throw new CodeSizeOverflow();
1509 } else {
1510 log.error(pos, "limit.code.too.large.for.try.stmt");
1511 nerrs++;
1512 }
1513 }
1514 }
1516 /** Very roughly estimate the number of instructions needed for
1517 * the given tree.
1518 */
1519 int estimateCodeComplexity(JCTree tree) {
1520 if (tree == null) return 0;
1521 class ComplexityScanner extends TreeScanner {
1522 int complexity = 0;
1523 public void scan(JCTree tree) {
1524 if (complexity > jsrlimit) return;
1525 super.scan(tree);
1526 }
1527 public void visitClassDef(JCClassDecl tree) {}
1528 public void visitDoLoop(JCDoWhileLoop tree)
1529 { super.visitDoLoop(tree); complexity++; }
1530 public void visitWhileLoop(JCWhileLoop tree)
1531 { super.visitWhileLoop(tree); complexity++; }
1532 public void visitForLoop(JCForLoop tree)
1533 { super.visitForLoop(tree); complexity++; }
1534 public void visitSwitch(JCSwitch tree)
1535 { super.visitSwitch(tree); complexity+=5; }
1536 public void visitCase(JCCase tree)
1537 { super.visitCase(tree); complexity++; }
1538 public void visitSynchronized(JCSynchronized tree)
1539 { super.visitSynchronized(tree); complexity+=6; }
1540 public void visitTry(JCTry tree)
1541 { super.visitTry(tree);
1542 if (tree.finalizer != null) complexity+=6; }
1543 public void visitCatch(JCCatch tree)
1544 { super.visitCatch(tree); complexity+=2; }
1545 public void visitConditional(JCConditional tree)
1546 { super.visitConditional(tree); complexity+=2; }
1547 public void visitIf(JCIf tree)
1548 { super.visitIf(tree); complexity+=2; }
1549 // note: for break, continue, and return we don't take unwind() into account.
1550 public void visitBreak(JCBreak tree)
1551 { super.visitBreak(tree); complexity+=1; }
1552 public void visitContinue(JCContinue tree)
1553 { super.visitContinue(tree); complexity+=1; }
1554 public void visitReturn(JCReturn tree)
1555 { super.visitReturn(tree); complexity+=1; }
1556 public void visitThrow(JCThrow tree)
1557 { super.visitThrow(tree); complexity+=1; }
1558 public void visitAssert(JCAssert tree)
1559 { super.visitAssert(tree); complexity+=5; }
1560 public void visitApply(JCMethodInvocation tree)
1561 { super.visitApply(tree); complexity+=2; }
1562 public void visitNewClass(JCNewClass tree)
1563 { scan(tree.encl); scan(tree.args); complexity+=2; }
1564 public void visitNewArray(JCNewArray tree)
1565 { super.visitNewArray(tree); complexity+=5; }
1566 public void visitAssign(JCAssign tree)
1567 { super.visitAssign(tree); complexity+=1; }
1568 public void visitAssignop(JCAssignOp tree)
1569 { super.visitAssignop(tree); complexity+=2; }
1570 public void visitUnary(JCUnary tree)
1571 { complexity+=1;
1572 if (tree.type.constValue() == null) super.visitUnary(tree); }
1573 public void visitBinary(JCBinary tree)
1574 { complexity+=1;
1575 if (tree.type.constValue() == null) super.visitBinary(tree); }
1576 public void visitTypeTest(JCInstanceOf tree)
1577 { super.visitTypeTest(tree); complexity+=1; }
1578 public void visitIndexed(JCArrayAccess tree)
1579 { super.visitIndexed(tree); complexity+=1; }
1580 public void visitSelect(JCFieldAccess tree)
1581 { super.visitSelect(tree);
1582 if (tree.sym.kind == VAR) complexity+=1; }
1583 public void visitIdent(JCIdent tree) {
1584 if (tree.sym.kind == VAR) {
1585 complexity+=1;
1586 if (tree.type.constValue() == null &&
1587 tree.sym.owner.kind == TYP)
1588 complexity+=1;
1589 }
1590 }
1591 public void visitLiteral(JCLiteral tree)
1592 { complexity+=1; }
1593 public void visitTree(JCTree tree) {}
1594 public void visitWildcard(JCWildcard tree) {
1595 throw new AssertionError(this.getClass().getName());
1596 }
1597 }
1598 ComplexityScanner scanner = new ComplexityScanner();
1599 tree.accept(scanner);
1600 return scanner.complexity;
1601 }
1603 public void visitIf(JCIf tree) {
1604 int limit = code.nextreg;
1605 Chain thenExit = null;
1606 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1607 CRT_FLOW_CONTROLLER);
1608 Chain elseChain = c.jumpFalse();
1609 if (!c.isFalse()) {
1610 code.resolve(c.trueJumps);
1611 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1612 thenExit = code.branch(goto_);
1613 }
1614 if (elseChain != null) {
1615 code.resolve(elseChain);
1616 if (tree.elsepart != null)
1617 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1618 }
1619 code.resolve(thenExit);
1620 code.endScopes(limit);
1621 }
1623 public void visitExec(JCExpressionStatement tree) {
1624 // Optimize x++ to ++x and x-- to --x.
1625 JCExpression e = tree.expr;
1626 switch (e.getTag()) {
1627 case POSTINC:
1628 ((JCUnary) e).setTag(PREINC);
1629 break;
1630 case POSTDEC:
1631 ((JCUnary) e).setTag(PREDEC);
1632 break;
1633 }
1634 genExpr(tree.expr, tree.expr.type).drop();
1635 }
1637 public void visitBreak(JCBreak tree) {
1638 Env<GenContext> targetEnv = unwind(tree.target, env);
1639 Assert.check(code.state.stacksize == 0);
1640 targetEnv.info.addExit(code.branch(goto_));
1641 endFinalizerGaps(env, targetEnv);
1642 }
1644 public void visitContinue(JCContinue tree) {
1645 Env<GenContext> targetEnv = unwind(tree.target, env);
1646 Assert.check(code.state.stacksize == 0);
1647 targetEnv.info.addCont(code.branch(goto_));
1648 endFinalizerGaps(env, targetEnv);
1649 }
1651 public void visitReturn(JCReturn tree) {
1652 int limit = code.nextreg;
1653 final Env<GenContext> targetEnv;
1654 if (tree.expr != null) {
1655 Item r = genExpr(tree.expr, pt).load();
1656 if (hasFinally(env.enclMethod, env)) {
1657 r = makeTemp(pt);
1658 r.store();
1659 }
1660 targetEnv = unwind(env.enclMethod, env);
1661 r.load();
1662 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
1663 } else {
1664 targetEnv = unwind(env.enclMethod, env);
1665 code.emitop0(return_);
1666 }
1667 endFinalizerGaps(env, targetEnv);
1668 code.endScopes(limit);
1669 }
1671 public void visitThrow(JCThrow tree) {
1672 genExpr(tree.expr, tree.expr.type).load();
1673 code.emitop0(athrow);
1674 }
1676 /* ************************************************************************
1677 * Visitor methods for expressions
1678 *************************************************************************/
1680 public void visitApply(JCMethodInvocation tree) {
1681 // Generate code for method.
1682 Item m = genExpr(tree.meth, methodType);
1683 // Generate code for all arguments, where the expected types are
1684 // the parameters of the method's external type (that is, any implicit
1685 // outer instance of a super(...) call appears as first parameter).
1686 genArgs(tree.args,
1687 TreeInfo.symbol(tree.meth).externalType(types).getParameterTypes());
1688 code.statBegin(tree.pos);
1689 code.markStatBegin();
1690 result = m.invoke();
1691 }
1693 public void visitConditional(JCConditional tree) {
1694 Chain thenExit = null;
1695 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
1696 Chain elseChain = c.jumpFalse();
1697 if (!c.isFalse()) {
1698 code.resolve(c.trueJumps);
1699 int startpc = genCrt ? code.curPc() : 0;
1700 genExpr(tree.truepart, pt).load();
1701 code.state.forceStackTop(tree.type);
1702 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
1703 startpc, code.curPc());
1704 thenExit = code.branch(goto_);
1705 }
1706 if (elseChain != null) {
1707 code.resolve(elseChain);
1708 int startpc = genCrt ? code.curPc() : 0;
1709 genExpr(tree.falsepart, pt).load();
1710 code.state.forceStackTop(tree.type);
1711 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
1712 startpc, code.curPc());
1713 }
1714 code.resolve(thenExit);
1715 result = items.makeStackItem(pt);
1716 }
1718 public void visitNewClass(JCNewClass tree) {
1719 // Enclosing instances or anonymous classes should have been eliminated
1720 // by now.
1721 Assert.check(tree.encl == null && tree.def == null);
1723 code.emitop2(new_, makeRef(tree.pos(), tree.type));
1724 code.emitop0(dup);
1726 // Generate code for all arguments, where the expected types are
1727 // the parameters of the constructor's external type (that is,
1728 // any implicit outer instance appears as first parameter).
1729 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
1731 items.makeMemberItem(tree.constructor, true).invoke();
1732 result = items.makeStackItem(tree.type);
1733 }
1735 public void visitNewArray(JCNewArray tree) {
1737 if (tree.elems != null) {
1738 Type elemtype = types.elemtype(tree.type);
1739 loadIntConst(tree.elems.length());
1740 Item arr = makeNewArray(tree.pos(), tree.type, 1);
1741 int i = 0;
1742 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
1743 arr.duplicate();
1744 loadIntConst(i);
1745 i++;
1746 genExpr(l.head, elemtype).load();
1747 items.makeIndexedItem(elemtype).store();
1748 }
1749 result = arr;
1750 } else {
1751 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1752 genExpr(l.head, syms.intType).load();
1753 }
1754 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
1755 }
1756 }
1757 //where
1758 /** Generate code to create an array with given element type and number
1759 * of dimensions.
1760 */
1761 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
1762 Type elemtype = types.elemtype(type);
1763 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
1764 log.error(pos, "limit.dimensions");
1765 nerrs++;
1766 }
1767 int elemcode = Code.arraycode(elemtype);
1768 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
1769 code.emitAnewarray(makeRef(pos, elemtype), type);
1770 } else if (elemcode == 1) {
1771 code.emitMultianewarray(ndims, makeRef(pos, type), type);
1772 } else {
1773 code.emitNewarray(elemcode, type);
1774 }
1775 return items.makeStackItem(type);
1776 }
1778 public void visitParens(JCParens tree) {
1779 result = genExpr(tree.expr, tree.expr.type);
1780 }
1782 public void visitAssign(JCAssign tree) {
1783 Item l = genExpr(tree.lhs, tree.lhs.type);
1784 genExpr(tree.rhs, tree.lhs.type).load();
1785 result = items.makeAssignItem(l);
1786 }
1788 public void visitAssignop(JCAssignOp tree) {
1789 OperatorSymbol operator = (OperatorSymbol) tree.operator;
1790 Item l;
1791 if (operator.opcode == string_add) {
1792 // Generate code to make a string buffer
1793 makeStringBuffer(tree.pos());
1795 // Generate code for first string, possibly save one
1796 // copy under buffer
1797 l = genExpr(tree.lhs, tree.lhs.type);
1798 if (l.width() > 0) {
1799 code.emitop0(dup_x1 + 3 * (l.width() - 1));
1800 }
1802 // Load first string and append to buffer.
1803 l.load();
1804 appendString(tree.lhs);
1806 // Append all other strings to buffer.
1807 appendStrings(tree.rhs);
1809 // Convert buffer to string.
1810 bufferToString(tree.pos());
1811 } else {
1812 // Generate code for first expression
1813 l = genExpr(tree.lhs, tree.lhs.type);
1815 // If we have an increment of -32768 to +32767 of a local
1816 // int variable we can use an incr instruction instead of
1817 // proceeding further.
1818 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
1819 l instanceof LocalItem &&
1820 tree.lhs.type.tag <= INT &&
1821 tree.rhs.type.tag <= INT &&
1822 tree.rhs.type.constValue() != null) {
1823 int ival = ((Number) tree.rhs.type.constValue()).intValue();
1824 if (tree.hasTag(MINUS_ASG)) ival = -ival;
1825 ((LocalItem)l).incr(ival);
1826 result = l;
1827 return;
1828 }
1829 // Otherwise, duplicate expression, load one copy
1830 // and complete binary operation.
1831 l.duplicate();
1832 l.coerce(operator.type.getParameterTypes().head).load();
1833 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
1834 }
1835 result = items.makeAssignItem(l);
1836 }
1838 public void visitUnary(JCUnary tree) {
1839 OperatorSymbol operator = (OperatorSymbol)tree.operator;
1840 if (tree.hasTag(NOT)) {
1841 CondItem od = genCond(tree.arg, false);
1842 result = od.negate();
1843 } else {
1844 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
1845 switch (tree.getTag()) {
1846 case POS:
1847 result = od.load();
1848 break;
1849 case NEG:
1850 result = od.load();
1851 code.emitop0(operator.opcode);
1852 break;
1853 case COMPL:
1854 result = od.load();
1855 emitMinusOne(od.typecode);
1856 code.emitop0(operator.opcode);
1857 break;
1858 case PREINC: case PREDEC:
1859 od.duplicate();
1860 if (od instanceof LocalItem &&
1861 (operator.opcode == iadd || operator.opcode == isub)) {
1862 ((LocalItem)od).incr(tree.hasTag(PREINC) ? 1 : -1);
1863 result = od;
1864 } else {
1865 od.load();
1866 code.emitop0(one(od.typecode));
1867 code.emitop0(operator.opcode);
1868 // Perform narrowing primitive conversion if byte,
1869 // char, or short. Fix for 4304655.
1870 if (od.typecode != INTcode &&
1871 Code.truncate(od.typecode) == INTcode)
1872 code.emitop0(int2byte + od.typecode - BYTEcode);
1873 result = items.makeAssignItem(od);
1874 }
1875 break;
1876 case POSTINC: case POSTDEC:
1877 od.duplicate();
1878 if (od instanceof LocalItem &&
1879 (operator.opcode == iadd || operator.opcode == isub)) {
1880 Item res = od.load();
1881 ((LocalItem)od).incr(tree.hasTag(POSTINC) ? 1 : -1);
1882 result = res;
1883 } else {
1884 Item res = od.load();
1885 od.stash(od.typecode);
1886 code.emitop0(one(od.typecode));
1887 code.emitop0(operator.opcode);
1888 // Perform narrowing primitive conversion if byte,
1889 // char, or short. Fix for 4304655.
1890 if (od.typecode != INTcode &&
1891 Code.truncate(od.typecode) == INTcode)
1892 code.emitop0(int2byte + od.typecode - BYTEcode);
1893 od.store();
1894 result = res;
1895 }
1896 break;
1897 case NULLCHK:
1898 result = od.load();
1899 code.emitop0(dup);
1900 genNullCheck(tree.pos());
1901 break;
1902 default:
1903 Assert.error();
1904 }
1905 }
1906 }
1908 /** Generate a null check from the object value at stack top. */
1909 private void genNullCheck(DiagnosticPosition pos) {
1910 callMethod(pos, syms.objectType, names.getClass,
1911 List.<Type>nil(), false);
1912 code.emitop0(pop);
1913 }
1915 public void visitBinary(JCBinary tree) {
1916 OperatorSymbol operator = (OperatorSymbol)tree.operator;
1917 if (operator.opcode == string_add) {
1918 // Create a string buffer.
1919 makeStringBuffer(tree.pos());
1920 // Append all strings to buffer.
1921 appendStrings(tree);
1922 // Convert buffer to string.
1923 bufferToString(tree.pos());
1924 result = items.makeStackItem(syms.stringType);
1925 } else if (tree.hasTag(AND)) {
1926 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
1927 if (!lcond.isFalse()) {
1928 Chain falseJumps = lcond.jumpFalse();
1929 code.resolve(lcond.trueJumps);
1930 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
1931 result = items.
1932 makeCondItem(rcond.opcode,
1933 rcond.trueJumps,
1934 Code.mergeChains(falseJumps,
1935 rcond.falseJumps));
1936 } else {
1937 result = lcond;
1938 }
1939 } else if (tree.hasTag(OR)) {
1940 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
1941 if (!lcond.isTrue()) {
1942 Chain trueJumps = lcond.jumpTrue();
1943 code.resolve(lcond.falseJumps);
1944 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
1945 result = items.
1946 makeCondItem(rcond.opcode,
1947 Code.mergeChains(trueJumps, rcond.trueJumps),
1948 rcond.falseJumps);
1949 } else {
1950 result = lcond;
1951 }
1952 } else {
1953 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
1954 od.load();
1955 result = completeBinop(tree.lhs, tree.rhs, operator);
1956 }
1957 }
1958 //where
1959 /** Make a new string buffer.
1960 */
1961 void makeStringBuffer(DiagnosticPosition pos) {
1962 code.emitop2(new_, makeRef(pos, stringBufferType));
1963 code.emitop0(dup);
1964 callMethod(
1965 pos, stringBufferType, names.init, List.<Type>nil(), false);
1966 }
1968 /** Append value (on tos) to string buffer (on tos - 1).
1969 */
1970 void appendString(JCTree tree) {
1971 Type t = tree.type.baseType();
1972 if (t.tag > lastBaseTag && t.tsym != syms.stringType.tsym) {
1973 t = syms.objectType;
1974 }
1975 items.makeMemberItem(getStringBufferAppend(tree, t), false).invoke();
1976 }
1977 Symbol getStringBufferAppend(JCTree tree, Type t) {
1978 Assert.checkNull(t.constValue());
1979 Symbol method = stringBufferAppend.get(t);
1980 if (method == null) {
1981 method = rs.resolveInternalMethod(tree.pos(),
1982 attrEnv,
1983 stringBufferType,
1984 names.append,
1985 List.of(t),
1986 null);
1987 stringBufferAppend.put(t, method);
1988 }
1989 return method;
1990 }
1992 /** Add all strings in tree to string buffer.
1993 */
1994 void appendStrings(JCTree tree) {
1995 tree = TreeInfo.skipParens(tree);
1996 if (tree.hasTag(PLUS) && tree.type.constValue() == null) {
1997 JCBinary op = (JCBinary) tree;
1998 if (op.operator.kind == MTH &&
1999 ((OperatorSymbol) op.operator).opcode == string_add) {
2000 appendStrings(op.lhs);
2001 appendStrings(op.rhs);
2002 return;
2003 }
2004 }
2005 genExpr(tree, tree.type).load();
2006 appendString(tree);
2007 }
2009 /** Convert string buffer on tos to string.
2010 */
2011 void bufferToString(DiagnosticPosition pos) {
2012 callMethod(
2013 pos,
2014 stringBufferType,
2015 names.toString,
2016 List.<Type>nil(),
2017 false);
2018 }
2020 /** Complete generating code for operation, with left operand
2021 * already on stack.
2022 * @param lhs The tree representing the left operand.
2023 * @param rhs The tree representing the right operand.
2024 * @param operator The operator symbol.
2025 */
2026 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2027 MethodType optype = (MethodType)operator.type;
2028 int opcode = operator.opcode;
2029 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2030 rhs.type.constValue() instanceof Number &&
2031 ((Number) rhs.type.constValue()).intValue() == 0) {
2032 opcode = opcode + (ifeq - if_icmpeq);
2033 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2034 TreeInfo.isNull(rhs)) {
2035 opcode = opcode + (if_acmp_null - if_acmpeq);
2036 } else {
2037 // The expected type of the right operand is
2038 // the second parameter type of the operator, except for
2039 // shifts with long shiftcount, where we convert the opcode
2040 // to a short shift and the expected type to int.
2041 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2042 if (opcode >= ishll && opcode <= lushrl) {
2043 opcode = opcode + (ishl - ishll);
2044 rtype = syms.intType;
2045 }
2046 // Generate code for right operand and load.
2047 genExpr(rhs, rtype).load();
2048 // If there are two consecutive opcode instructions,
2049 // emit the first now.
2050 if (opcode >= (1 << preShift)) {
2051 code.emitop0(opcode >> preShift);
2052 opcode = opcode & 0xFF;
2053 }
2054 }
2055 if (opcode >= ifeq && opcode <= if_acmpne ||
2056 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2057 return items.makeCondItem(opcode);
2058 } else {
2059 code.emitop0(opcode);
2060 return items.makeStackItem(optype.restype);
2061 }
2062 }
2064 public void visitTypeCast(JCTypeCast tree) {
2065 result = genExpr(tree.expr, tree.clazz.type).load();
2066 // Additional code is only needed if we cast to a reference type
2067 // which is not statically a supertype of the expression's type.
2068 // For basic types, the coerce(...) in genExpr(...) will do
2069 // the conversion.
2070 if (tree.clazz.type.tag > lastBaseTag &&
2071 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2072 code.emitop2(checkcast, makeRef(tree.pos(), tree.clazz.type));
2073 }
2074 }
2076 public void visitWildcard(JCWildcard tree) {
2077 throw new AssertionError(this.getClass().getName());
2078 }
2080 public void visitTypeTest(JCInstanceOf tree) {
2081 genExpr(tree.expr, tree.expr.type).load();
2082 code.emitop2(instanceof_, makeRef(tree.pos(), tree.clazz.type));
2083 result = items.makeStackItem(syms.booleanType);
2084 }
2086 public void visitIndexed(JCArrayAccess tree) {
2087 genExpr(tree.indexed, tree.indexed.type).load();
2088 genExpr(tree.index, syms.intType).load();
2089 result = items.makeIndexedItem(tree.type);
2090 }
2092 public void visitIdent(JCIdent tree) {
2093 Symbol sym = tree.sym;
2094 if (tree.name == names._this || tree.name == names._super) {
2095 Item res = tree.name == names._this
2096 ? items.makeThisItem()
2097 : items.makeSuperItem();
2098 if (sym.kind == MTH) {
2099 // Generate code to address the constructor.
2100 res.load();
2101 res = items.makeMemberItem(sym, true);
2102 }
2103 result = res;
2104 } else if (sym.kind == VAR && sym.owner.kind == MTH) {
2105 result = items.makeLocalItem((VarSymbol)sym);
2106 } else if ((sym.flags() & STATIC) != 0) {
2107 if (!isAccessSuper(env.enclMethod))
2108 sym = binaryQualifier(sym, env.enclClass.type);
2109 result = items.makeStaticItem(sym);
2110 } else {
2111 items.makeThisItem().load();
2112 sym = binaryQualifier(sym, env.enclClass.type);
2113 result = items.makeMemberItem(sym, (sym.flags() & PRIVATE) != 0);
2114 }
2115 }
2117 public void visitSelect(JCFieldAccess tree) {
2118 Symbol sym = tree.sym;
2120 if (tree.name == names._class) {
2121 Assert.check(target.hasClassLiterals());
2122 code.emitop2(ldc2, makeRef(tree.pos(), tree.selected.type));
2123 result = items.makeStackItem(pt);
2124 return;
2125 }
2127 Symbol ssym = TreeInfo.symbol(tree.selected);
2129 // Are we selecting via super?
2130 boolean selectSuper =
2131 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2133 // Are we accessing a member of the superclass in an access method
2134 // resulting from a qualified super?
2135 boolean accessSuper = isAccessSuper(env.enclMethod);
2137 Item base = (selectSuper)
2138 ? items.makeSuperItem()
2139 : genExpr(tree.selected, tree.selected.type);
2141 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2142 // We are seeing a variable that is constant but its selecting
2143 // expression is not.
2144 if ((sym.flags() & STATIC) != 0) {
2145 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2146 base = base.load();
2147 base.drop();
2148 } else {
2149 base.load();
2150 genNullCheck(tree.selected.pos());
2151 }
2152 result = items.
2153 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2154 } else {
2155 if (!accessSuper)
2156 sym = binaryQualifier(sym, tree.selected.type);
2157 if ((sym.flags() & STATIC) != 0) {
2158 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2159 base = base.load();
2160 base.drop();
2161 result = items.makeStaticItem(sym);
2162 } else {
2163 base.load();
2164 if (sym == syms.lengthVar) {
2165 code.emitop0(arraylength);
2166 result = items.makeStackItem(syms.intType);
2167 } else {
2168 result = items.
2169 makeMemberItem(sym,
2170 (sym.flags() & PRIVATE) != 0 ||
2171 selectSuper || accessSuper);
2172 }
2173 }
2174 }
2175 }
2177 public void visitLiteral(JCLiteral tree) {
2178 if (tree.type.tag == TypeTags.BOT) {
2179 code.emitop0(aconst_null);
2180 if (types.dimensions(pt) > 1) {
2181 code.emitop2(checkcast, makeRef(tree.pos(), pt));
2182 result = items.makeStackItem(pt);
2183 } else {
2184 result = items.makeStackItem(tree.type);
2185 }
2186 }
2187 else
2188 result = items.makeImmediateItem(tree.type, tree.value);
2189 }
2191 public void visitLetExpr(LetExpr tree) {
2192 int limit = code.nextreg;
2193 genStats(tree.defs, env);
2194 result = genExpr(tree.expr, tree.expr.type).load();
2195 code.endScopes(limit);
2196 }
2198 /* ************************************************************************
2199 * main method
2200 *************************************************************************/
2202 /** Generate code for a class definition.
2203 * @param env The attribution environment that belongs to the
2204 * outermost class containing this class definition.
2205 * We need this for resolving some additional symbols.
2206 * @param cdef The tree representing the class definition.
2207 * @return True if code is generated with no errors.
2208 */
2209 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2210 try {
2211 attrEnv = env;
2212 ClassSymbol c = cdef.sym;
2213 this.toplevel = env.toplevel;
2214 this.endPosTable = toplevel.endPositions;
2215 // If this is a class definition requiring Miranda methods,
2216 // add them.
2217 if (generateIproxies &&
2218 (c.flags() & (INTERFACE|ABSTRACT)) == ABSTRACT
2219 && !allowGenerics // no Miranda methods available with generics
2220 )
2221 implementInterfaceMethods(c);
2222 cdef.defs = normalizeDefs(cdef.defs, c);
2223 c.pool = pool;
2224 pool.reset();
2225 Env<GenContext> localEnv =
2226 new Env<GenContext>(cdef, new GenContext());
2227 localEnv.toplevel = env.toplevel;
2228 localEnv.enclClass = cdef;
2229 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2230 genDef(l.head, localEnv);
2231 }
2232 if (pool.numEntries() > Pool.MAX_ENTRIES) {
2233 log.error(cdef.pos(), "limit.pool");
2234 nerrs++;
2235 }
2236 if (nerrs != 0) {
2237 // if errors, discard code
2238 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2239 if (l.head.hasTag(METHODDEF))
2240 ((JCMethodDecl) l.head).sym.code = null;
2241 }
2242 }
2243 cdef.defs = List.nil(); // discard trees
2244 return nerrs == 0;
2245 } finally {
2246 // note: this method does NOT support recursion.
2247 attrEnv = null;
2248 this.env = null;
2249 toplevel = null;
2250 endPosTable = null;
2251 nerrs = 0;
2252 }
2253 }
2255 /* ************************************************************************
2256 * Auxiliary classes
2257 *************************************************************************/
2259 /** An abstract class for finalizer generation.
2260 */
2261 abstract class GenFinalizer {
2262 /** Generate code to clean up when unwinding. */
2263 abstract void gen();
2265 /** Generate code to clean up at last. */
2266 abstract void genLast();
2268 /** Does this finalizer have some nontrivial cleanup to perform? */
2269 boolean hasFinalizer() { return true; }
2270 }
2272 /** code generation contexts,
2273 * to be used as type parameter for environments.
2274 */
2275 static class GenContext {
2277 /** A chain for all unresolved jumps that exit the current environment.
2278 */
2279 Chain exit = null;
2281 /** A chain for all unresolved jumps that continue in the
2282 * current environment.
2283 */
2284 Chain cont = null;
2286 /** A closure that generates the finalizer of the current environment.
2287 * Only set for Synchronized and Try contexts.
2288 */
2289 GenFinalizer finalize = null;
2291 /** Is this a switch statement? If so, allocate registers
2292 * even when the variable declaration is unreachable.
2293 */
2294 boolean isSwitch = false;
2296 /** A list buffer containing all gaps in the finalizer range,
2297 * where a catch all exception should not apply.
2298 */
2299 ListBuffer<Integer> gaps = null;
2301 /** Add given chain to exit chain.
2302 */
2303 void addExit(Chain c) {
2304 exit = Code.mergeChains(c, exit);
2305 }
2307 /** Add given chain to cont chain.
2308 */
2309 void addCont(Chain c) {
2310 cont = Code.mergeChains(c, cont);
2311 }
2312 }
2313 }
