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src/share/classes/com/sun/tools/javac/jvm/Gen.java@005bec70ca27
src/share/classes/com/sun/tools/javac/jvm/Gen.java
Fri, 18 Jun 2010 15:12:04 -0700
- author
- jrose
- date
- Fri, 18 Jun 2010 15:12:04 -0700
- changeset 573
- 005bec70ca27
- parent 554
- 9d9f26857129
- parent 571
- f0e3ec1f9d9f
- child 591
- d1d7595fa824
- permissions
- -rw-r--r--
Merge
1 /*
2 * Copyright (c) 1999, 2009, 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 javax.lang.model.element.ElementKind;
31 import com.sun.tools.javac.util.*;
32 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
33 import com.sun.tools.javac.util.List;
34 import com.sun.tools.javac.code.*;
35 import com.sun.tools.javac.comp.*;
36 import com.sun.tools.javac.tree.*;
38 import com.sun.tools.javac.code.Symbol.*;
39 import com.sun.tools.javac.code.Type.*;
40 import com.sun.tools.javac.jvm.Code.*;
41 import com.sun.tools.javac.jvm.Items.*;
42 import com.sun.tools.javac.tree.JCTree.*;
44 import static com.sun.tools.javac.code.Flags.*;
45 import static com.sun.tools.javac.code.Kinds.*;
46 import static com.sun.tools.javac.code.TypeTags.*;
47 import static com.sun.tools.javac.jvm.ByteCodes.*;
48 import static com.sun.tools.javac.jvm.CRTFlags.*;
50 /** This pass maps flat Java (i.e. without inner classes) to bytecodes.
51 *
52 * <p><b>This is NOT part of any API supported by Sun Microsystems. If
53 * you write code that depends on this, you do so at your own risk.
54 * This code and its internal interfaces are subject to change or
55 * deletion without notice.</b>
56 */
57 public class Gen extends JCTree.Visitor {
58 protected static final Context.Key<Gen> genKey =
59 new Context.Key<Gen>();
61 private final Log log;
62 private final Symtab syms;
63 private final Check chk;
64 private final Resolve rs;
65 private final TreeMaker make;
66 private final Names names;
67 private final Target target;
68 private final Type stringBufferType;
69 private final Map<Type,Symbol> stringBufferAppend;
70 private Name accessDollar;
71 private final Types types;
73 /** Switch: GJ mode?
74 */
75 private final boolean allowGenerics;
77 /** Set when Miranda method stubs are to be generated. */
78 private final boolean generateIproxies;
80 /** Format of stackmap tables to be generated. */
81 private final Code.StackMapFormat stackMap;
83 /** A type that serves as the expected type for all method expressions.
84 */
85 private final Type methodType;
87 public static Gen instance(Context context) {
88 Gen instance = context.get(genKey);
89 if (instance == null)
90 instance = new Gen(context);
91 return instance;
92 }
94 protected Gen(Context context) {
95 context.put(genKey, this);
97 names = Names.instance(context);
98 log = Log.instance(context);
99 syms = Symtab.instance(context);
100 chk = Check.instance(context);
101 rs = Resolve.instance(context);
102 make = TreeMaker.instance(context);
103 target = Target.instance(context);
104 types = Types.instance(context);
105 methodType = new MethodType(null, null, null, syms.methodClass);
106 allowGenerics = Source.instance(context).allowGenerics();
107 stringBufferType = target.useStringBuilder()
108 ? syms.stringBuilderType
109 : syms.stringBufferType;
110 stringBufferAppend = new HashMap<Type,Symbol>();
111 accessDollar = names.
112 fromString("access" + target.syntheticNameChar());
114 Options options = Options.instance(context);
115 lineDebugInfo =
116 options.get("-g:") == null ||
117 options.get("-g:lines") != null;
118 varDebugInfo =
119 options.get("-g:") == null
120 ? options.get("-g") != null
121 : options.get("-g:vars") != null;
122 genCrt = options.get("-Xjcov") != null;
123 debugCode = options.get("debugcode") != null;
124 allowInvokedynamic = target.hasInvokedynamic() || options.get("invokedynamic") != null;
126 generateIproxies =
127 target.requiresIproxy() ||
128 options.get("miranda") != null;
130 if (target.generateStackMapTable()) {
131 // ignore cldc because we cannot have both stackmap formats
132 this.stackMap = StackMapFormat.JSR202;
133 } else {
134 if (target.generateCLDCStackmap()) {
135 this.stackMap = StackMapFormat.CLDC;
136 } else {
137 this.stackMap = StackMapFormat.NONE;
138 }
139 }
141 // by default, avoid jsr's for simple finalizers
142 int setjsrlimit = 50;
143 String jsrlimitString = options.get("jsrlimit");
144 if (jsrlimitString != null) {
145 try {
146 setjsrlimit = Integer.parseInt(jsrlimitString);
147 } catch (NumberFormatException ex) {
148 // ignore ill-formed numbers for jsrlimit
149 }
150 }
151 this.jsrlimit = setjsrlimit;
152 this.useJsrLocally = false; // reset in visitTry
153 }
155 /** Switches
156 */
157 private final boolean lineDebugInfo;
158 private final boolean varDebugInfo;
159 private final boolean genCrt;
160 private final boolean debugCode;
161 private final boolean allowInvokedynamic;
163 /** Default limit of (approximate) size of finalizer to inline.
164 * Zero means always use jsr. 100 or greater means never use
165 * jsr.
166 */
167 private final int jsrlimit;
169 /** True if jsr is used.
170 */
171 private boolean useJsrLocally;
173 /* Constant pool, reset by genClass.
174 */
175 private Pool pool = new Pool();
177 /** Code buffer, set by genMethod.
178 */
179 private Code code;
181 /** Items structure, set by genMethod.
182 */
183 private Items items;
185 /** Environment for symbol lookup, set by genClass
186 */
187 private Env<AttrContext> attrEnv;
189 /** The top level tree.
190 */
191 private JCCompilationUnit toplevel;
193 /** The number of code-gen errors in this class.
194 */
195 private int nerrs = 0;
197 /** A hash table mapping syntax trees to their ending source positions.
198 */
199 private Map<JCTree, Integer> endPositions;
201 /** Generate code to load an integer constant.
202 * @param n The integer to be loaded.
203 */
204 void loadIntConst(int n) {
205 items.makeImmediateItem(syms.intType, n).load();
206 }
208 /** The opcode that loads a zero constant of a given type code.
209 * @param tc The given type code (@see ByteCode).
210 */
211 public static int zero(int tc) {
212 switch(tc) {
213 case INTcode: case BYTEcode: case SHORTcode: case CHARcode:
214 return iconst_0;
215 case LONGcode:
216 return lconst_0;
217 case FLOATcode:
218 return fconst_0;
219 case DOUBLEcode:
220 return dconst_0;
221 default:
222 throw new AssertionError("zero");
223 }
224 }
226 /** The opcode that loads a one constant of a given type code.
227 * @param tc The given type code (@see ByteCode).
228 */
229 public static int one(int tc) {
230 return zero(tc) + 1;
231 }
233 /** Generate code to load -1 of the given type code (either int or long).
234 * @param tc The given type code (@see ByteCode).
235 */
236 void emitMinusOne(int tc) {
237 if (tc == LONGcode) {
238 items.makeImmediateItem(syms.longType, new Long(-1)).load();
239 } else {
240 code.emitop0(iconst_m1);
241 }
242 }
244 /** Construct a symbol to reflect the qualifying type that should
245 * appear in the byte code as per JLS 13.1.
246 *
247 * For target >= 1.2: Clone a method with the qualifier as owner (except
248 * for those cases where we need to work around VM bugs).
249 *
250 * For target <= 1.1: If qualified variable or method is defined in a
251 * non-accessible class, clone it with the qualifier class as owner.
252 *
253 * @param sym The accessed symbol
254 * @param site The qualifier's type.
255 */
256 Symbol binaryQualifier(Symbol sym, Type site) {
258 if (site.tag == ARRAY) {
259 if (sym == syms.lengthVar ||
260 sym.owner != syms.arrayClass)
261 return sym;
262 // array clone can be qualified by the array type in later targets
263 Symbol qualifier = target.arrayBinaryCompatibility()
264 ? new ClassSymbol(Flags.PUBLIC, site.tsym.name,
265 site, syms.noSymbol)
266 : syms.objectType.tsym;
267 return sym.clone(qualifier);
268 }
270 if (sym.owner == site.tsym ||
271 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) {
272 return sym;
273 }
274 if (!target.obeyBinaryCompatibility())
275 return rs.isAccessible(attrEnv, (TypeSymbol)sym.owner)
276 ? sym
277 : sym.clone(site.tsym);
279 if (!target.interfaceFieldsBinaryCompatibility()) {
280 if ((sym.owner.flags() & INTERFACE) != 0 && sym.kind == VAR)
281 return sym;
282 }
284 // leave alone methods inherited from Object
285 // JLS2 13.1.
286 if (sym.owner == syms.objectType.tsym)
287 return sym;
289 if (!target.interfaceObjectOverridesBinaryCompatibility()) {
290 if ((sym.owner.flags() & INTERFACE) != 0 &&
291 syms.objectType.tsym.members().lookup(sym.name).scope != null)
292 return sym;
293 }
295 return sym.clone(site.tsym);
296 }
298 /** Insert a reference to given type in the constant pool,
299 * checking for an array with too many dimensions;
300 * return the reference's index.
301 * @param type The type for which a reference is inserted.
302 */
303 int makeRef(DiagnosticPosition pos, Type type) {
304 checkDimension(pos, type);
305 return pool.put(type.tag == CLASS ? (Object)type.tsym : (Object)type);
306 }
308 /** Check if the given type is an array with too many dimensions.
309 */
310 private void checkDimension(DiagnosticPosition pos, Type t) {
311 switch (t.tag) {
312 case METHOD:
313 checkDimension(pos, t.getReturnType());
314 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail)
315 checkDimension(pos, args.head);
316 break;
317 case ARRAY:
318 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) {
319 log.error(pos, "limit.dimensions");
320 nerrs++;
321 }
322 break;
323 default:
324 break;
325 }
326 }
328 /** Create a tempory variable.
329 * @param type The variable's type.
330 */
331 LocalItem makeTemp(Type type) {
332 VarSymbol v = new VarSymbol(Flags.SYNTHETIC,
333 names.empty,
334 type,
335 env.enclMethod.sym);
336 code.newLocal(v);
337 return items.makeLocalItem(v);
338 }
340 /** Generate code to call a non-private method or constructor.
341 * @param pos Position to be used for error reporting.
342 * @param site The type of which the method is a member.
343 * @param name The method's name.
344 * @param argtypes The method's argument types.
345 * @param isStatic A flag that indicates whether we call a
346 * static or instance method.
347 */
348 void callMethod(DiagnosticPosition pos,
349 Type site, Name name, List<Type> argtypes,
350 boolean isStatic) {
351 Symbol msym = rs.
352 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null);
353 if (isStatic) items.makeStaticItem(msym).invoke();
354 else items.makeMemberItem(msym, name == names.init).invoke();
355 }
357 /** Is the given method definition an access method
358 * resulting from a qualified super? This is signified by an odd
359 * access code.
360 */
361 private boolean isAccessSuper(JCMethodDecl enclMethod) {
362 return
363 (enclMethod.mods.flags & SYNTHETIC) != 0 &&
364 isOddAccessName(enclMethod.name);
365 }
367 /** Does given name start with "access$" and end in an odd digit?
368 */
369 private boolean isOddAccessName(Name name) {
370 return
371 name.startsWith(accessDollar) &&
372 (name.getByteAt(name.getByteLength() - 1) & 1) == 1;
373 }
375 /* ************************************************************************
376 * Non-local exits
377 *************************************************************************/
379 /** Generate code to invoke the finalizer associated with given
380 * environment.
381 * Any calls to finalizers are appended to the environments `cont' chain.
382 * Mark beginning of gap in catch all range for finalizer.
383 */
384 void genFinalizer(Env<GenContext> env) {
385 if (code.isAlive() && env.info.finalize != null)
386 env.info.finalize.gen();
387 }
389 /** Generate code to call all finalizers of structures aborted by
390 * a non-local
391 * exit. Return target environment of the non-local exit.
392 * @param target The tree representing the structure that's aborted
393 * @param env The environment current at the non-local exit.
394 */
395 Env<GenContext> unwind(JCTree target, Env<GenContext> env) {
396 Env<GenContext> env1 = env;
397 while (true) {
398 genFinalizer(env1);
399 if (env1.tree == target) break;
400 env1 = env1.next;
401 }
402 return env1;
403 }
405 /** Mark end of gap in catch-all range for finalizer.
406 * @param env the environment which might contain the finalizer
407 * (if it does, env.info.gaps != null).
408 */
409 void endFinalizerGap(Env<GenContext> env) {
410 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1)
411 env.info.gaps.append(code.curPc());
412 }
414 /** Mark end of all gaps in catch-all ranges for finalizers of environments
415 * lying between, and including to two environments.
416 * @param from the most deeply nested environment to mark
417 * @param to the least deeply nested environment to mark
418 */
419 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) {
420 Env<GenContext> last = null;
421 while (last != to) {
422 endFinalizerGap(from);
423 last = from;
424 from = from.next;
425 }
426 }
428 /** Do any of the structures aborted by a non-local exit have
429 * finalizers that require an empty stack?
430 * @param target The tree representing the structure that's aborted
431 * @param env The environment current at the non-local exit.
432 */
433 boolean hasFinally(JCTree target, Env<GenContext> env) {
434 while (env.tree != target) {
435 if (env.tree.getTag() == JCTree.TRY && env.info.finalize.hasFinalizer())
436 return true;
437 env = env.next;
438 }
439 return false;
440 }
442 /* ************************************************************************
443 * Normalizing class-members.
444 *************************************************************************/
446 /** Distribute member initializer code into constructors and <clinit>
447 * method.
448 * @param defs The list of class member declarations.
449 * @param c The enclosing class.
450 */
451 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) {
452 ListBuffer<JCStatement> initCode = new ListBuffer<JCStatement>();
453 ListBuffer<JCStatement> clinitCode = new ListBuffer<JCStatement>();
454 ListBuffer<JCTree> methodDefs = new ListBuffer<JCTree>();
455 // Sort definitions into three listbuffers:
456 // - initCode for instance initializers
457 // - clinitCode for class initializers
458 // - methodDefs for method definitions
459 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
460 JCTree def = l.head;
461 switch (def.getTag()) {
462 case JCTree.BLOCK:
463 JCBlock block = (JCBlock)def;
464 if ((block.flags & STATIC) != 0)
465 clinitCode.append(block);
466 else
467 initCode.append(block);
468 break;
469 case JCTree.METHODDEF:
470 methodDefs.append(def);
471 break;
472 case JCTree.VARDEF:
473 JCVariableDecl vdef = (JCVariableDecl) def;
474 VarSymbol sym = vdef.sym;
475 checkDimension(vdef.pos(), sym.type);
476 if (vdef.init != null) {
477 if ((sym.flags() & STATIC) == 0) {
478 // Always initialize instance variables.
479 JCStatement init = make.at(vdef.pos()).
480 Assignment(sym, vdef.init);
481 initCode.append(init);
482 if (endPositions != null) {
483 Integer endPos = endPositions.remove(vdef);
484 if (endPos != null) endPositions.put(init, endPos);
485 }
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 if (endPositions != null) {
493 Integer endPos = endPositions.remove(vdef);
494 if (endPos != null) endPositions.put(init, endPos);
495 }
496 } else {
497 checkStringConstant(vdef.init.pos(), sym.getConstValue());
498 }
499 }
500 break;
501 default:
502 assert false;
503 }
504 }
505 // Insert any instance initializers into all constructors.
506 if (initCode.length() != 0) {
507 List<JCStatement> inits = initCode.toList();
508 for (JCTree t : methodDefs) {
509 normalizeMethod((JCMethodDecl)t, inits);
510 }
511 }
512 // If there are class initializers, create a <clinit> method
513 // that contains them as its body.
514 if (clinitCode.length() != 0) {
515 MethodSymbol clinit = new MethodSymbol(
516 STATIC, names.clinit,
517 new MethodType(
518 List.<Type>nil(), syms.voidType,
519 List.<Type>nil(), syms.methodClass),
520 c);
521 c.members().enter(clinit);
522 List<JCStatement> clinitStats = clinitCode.toList();
523 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
524 block.endpos = TreeInfo.endPos(clinitStats.last());
525 methodDefs.append(make.MethodDef(clinit, block));
526 }
527 // Return all method definitions.
528 return methodDefs.toList();
529 }
531 /** Check a constant value and report if it is a string that is
532 * too large.
533 */
534 private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
535 if (nerrs != 0 || // only complain about a long string once
536 constValue == null ||
537 !(constValue instanceof String) ||
538 ((String)constValue).length() < Pool.MAX_STRING_LENGTH)
539 return;
540 log.error(pos, "limit.string");
541 nerrs++;
542 }
544 /** Insert instance initializer code into initial constructor.
545 * @param md The tree potentially representing a
546 * constructor's definition.
547 * @param initCode The list of instance initializer statements.
548 */
549 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode) {
550 if (md.name == names.init && TreeInfo.isInitialConstructor(md)) {
551 // We are seeing a constructor that does not call another
552 // constructor of the same class.
553 List<JCStatement> stats = md.body.stats;
554 ListBuffer<JCStatement> newstats = new ListBuffer<JCStatement>();
556 if (stats.nonEmpty()) {
557 // Copy initializers of synthetic variables generated in
558 // the translation of inner classes.
559 while (TreeInfo.isSyntheticInit(stats.head)) {
560 newstats.append(stats.head);
561 stats = stats.tail;
562 }
563 // Copy superclass constructor call
564 newstats.append(stats.head);
565 stats = stats.tail;
566 // Copy remaining synthetic initializers.
567 while (stats.nonEmpty() &&
568 TreeInfo.isSyntheticInit(stats.head)) {
569 newstats.append(stats.head);
570 stats = stats.tail;
571 }
572 // Now insert the initializer code.
573 newstats.appendList(initCode);
574 // And copy all remaining statements.
575 while (stats.nonEmpty()) {
576 newstats.append(stats.head);
577 stats = stats.tail;
578 }
579 }
580 md.body.stats = newstats.toList();
581 if (md.body.endpos == Position.NOPOS)
582 md.body.endpos = TreeInfo.endPos(md.body.stats.last());
583 }
584 }
586 /* ********************************************************************
587 * Adding miranda methods
588 *********************************************************************/
590 /** Add abstract methods for all methods defined in one of
591 * the interfaces of a given class,
592 * provided they are not already implemented in the class.
593 *
594 * @param c The class whose interfaces are searched for methods
595 * for which Miranda methods should be added.
596 */
597 void implementInterfaceMethods(ClassSymbol c) {
598 implementInterfaceMethods(c, c);
599 }
601 /** Add abstract methods for all methods defined in one of
602 * the interfaces of a given class,
603 * provided they are not already implemented in the class.
604 *
605 * @param c The class whose interfaces are searched for methods
606 * for which Miranda methods should be added.
607 * @param site The class in which a definition may be needed.
608 */
609 void implementInterfaceMethods(ClassSymbol c, ClassSymbol site) {
610 for (List<Type> l = types.interfaces(c.type); l.nonEmpty(); l = l.tail) {
611 ClassSymbol i = (ClassSymbol)l.head.tsym;
612 for (Scope.Entry e = i.members().elems;
613 e != null;
614 e = e.sibling)
615 {
616 if (e.sym.kind == MTH && (e.sym.flags() & STATIC) == 0)
617 {
618 MethodSymbol absMeth = (MethodSymbol)e.sym;
619 MethodSymbol implMeth = absMeth.binaryImplementation(site, types);
620 if (implMeth == null)
621 addAbstractMethod(site, absMeth);
622 else if ((implMeth.flags() & IPROXY) != 0)
623 adjustAbstractMethod(site, implMeth, absMeth);
624 }
625 }
626 implementInterfaceMethods(i, site);
627 }
628 }
630 /** Add an abstract methods to a class
631 * which implicitly implements a method defined in some interface
632 * implemented by the class. These methods are called "Miranda methods".
633 * Enter the newly created method into its enclosing class scope.
634 * Note that it is not entered into the class tree, as the emitter
635 * doesn't need to see it there to emit an abstract method.
636 *
637 * @param c The class to which the Miranda method is added.
638 * @param m The interface method symbol for which a Miranda method
639 * is added.
640 */
641 private void addAbstractMethod(ClassSymbol c,
642 MethodSymbol m) {
643 MethodSymbol absMeth = new MethodSymbol(
644 m.flags() | IPROXY | SYNTHETIC, m.name,
645 m.type, // was c.type.memberType(m), but now only !generics supported
646 c);
647 c.members().enter(absMeth); // add to symbol table
648 }
650 private void adjustAbstractMethod(ClassSymbol c,
651 MethodSymbol pm,
652 MethodSymbol im) {
653 MethodType pmt = (MethodType)pm.type;
654 Type imt = types.memberType(c.type, im);
655 pmt.thrown = chk.intersect(pmt.getThrownTypes(), imt.getThrownTypes());
656 }
658 /* ************************************************************************
659 * Traversal methods
660 *************************************************************************/
662 /** Visitor argument: The current environment.
663 */
664 Env<GenContext> env;
666 /** Visitor argument: The expected type (prototype).
667 */
668 Type pt;
670 /** Visitor result: The item representing the computed value.
671 */
672 Item result;
674 /** Visitor method: generate code for a definition, catching and reporting
675 * any completion failures.
676 * @param tree The definition to be visited.
677 * @param env The environment current at the definition.
678 */
679 public void genDef(JCTree tree, Env<GenContext> env) {
680 Env<GenContext> prevEnv = this.env;
681 try {
682 this.env = env;
683 tree.accept(this);
684 } catch (CompletionFailure ex) {
685 chk.completionError(tree.pos(), ex);
686 } finally {
687 this.env = prevEnv;
688 }
689 }
691 /** Derived visitor method: check whether CharacterRangeTable
692 * should be emitted, if so, put a new entry into CRTable
693 * and call method to generate bytecode.
694 * If not, just call method to generate bytecode.
695 * @see #genStat(Tree, Env)
696 *
697 * @param tree The tree to be visited.
698 * @param env The environment to use.
699 * @param crtFlags The CharacterRangeTable flags
700 * indicating type of the entry.
701 */
702 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
703 if (!genCrt) {
704 genStat(tree, env);
705 return;
706 }
707 int startpc = code.curPc();
708 genStat(tree, env);
709 if (tree.getTag() == JCTree.BLOCK) crtFlags |= CRT_BLOCK;
710 code.crt.put(tree, crtFlags, startpc, code.curPc());
711 }
713 /** Derived visitor method: generate code for a statement.
714 */
715 public void genStat(JCTree tree, Env<GenContext> env) {
716 if (code.isAlive()) {
717 code.statBegin(tree.pos);
718 genDef(tree, env);
719 } else if (env.info.isSwitch && tree.getTag() == JCTree.VARDEF) {
720 // variables whose declarations are in a switch
721 // can be used even if the decl is unreachable.
722 code.newLocal(((JCVariableDecl) tree).sym);
723 }
724 }
726 /** Derived visitor method: check whether CharacterRangeTable
727 * should be emitted, if so, put a new entry into CRTable
728 * and call method to generate bytecode.
729 * If not, just call method to generate bytecode.
730 * @see #genStats(List, Env)
731 *
732 * @param trees The list of trees to be visited.
733 * @param env The environment to use.
734 * @param crtFlags The CharacterRangeTable flags
735 * indicating type of the entry.
736 */
737 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
738 if (!genCrt) {
739 genStats(trees, env);
740 return;
741 }
742 if (trees.length() == 1) { // mark one statement with the flags
743 genStat(trees.head, env, crtFlags | CRT_STATEMENT);
744 } else {
745 int startpc = code.curPc();
746 genStats(trees, env);
747 code.crt.put(trees, crtFlags, startpc, code.curPc());
748 }
749 }
751 /** Derived visitor method: generate code for a list of statements.
752 */
753 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) {
754 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
755 genStat(l.head, env, CRT_STATEMENT);
756 }
758 /** Derived visitor method: check whether CharacterRangeTable
759 * should be emitted, if so, put a new entry into CRTable
760 * and call method to generate bytecode.
761 * If not, just call method to generate bytecode.
762 * @see #genCond(Tree,boolean)
763 *
764 * @param tree The tree to be visited.
765 * @param crtFlags The CharacterRangeTable flags
766 * indicating type of the entry.
767 */
768 public CondItem genCond(JCTree tree, int crtFlags) {
769 if (!genCrt) return genCond(tree, false);
770 int startpc = code.curPc();
771 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
772 code.crt.put(tree, crtFlags, startpc, code.curPc());
773 return item;
774 }
776 /** Derived visitor method: generate code for a boolean
777 * expression in a control-flow context.
778 * @param _tree The expression to be visited.
779 * @param markBranches The flag to indicate that the condition is
780 * a flow controller so produced conditions
781 * should contain a proper tree to generate
782 * CharacterRangeTable branches for them.
783 */
784 public CondItem genCond(JCTree _tree, boolean markBranches) {
785 JCTree inner_tree = TreeInfo.skipParens(_tree);
786 if (inner_tree.getTag() == JCTree.CONDEXPR) {
787 JCConditional tree = (JCConditional)inner_tree;
788 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
789 if (cond.isTrue()) {
790 code.resolve(cond.trueJumps);
791 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
792 if (markBranches) result.tree = tree.truepart;
793 return result;
794 }
795 if (cond.isFalse()) {
796 code.resolve(cond.falseJumps);
797 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
798 if (markBranches) result.tree = tree.falsepart;
799 return result;
800 }
801 Chain secondJumps = cond.jumpFalse();
802 code.resolve(cond.trueJumps);
803 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
804 if (markBranches) first.tree = tree.truepart;
805 Chain falseJumps = first.jumpFalse();
806 code.resolve(first.trueJumps);
807 Chain trueJumps = code.branch(goto_);
808 code.resolve(secondJumps);
809 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
810 CondItem result = items.makeCondItem(second.opcode,
811 Code.mergeChains(trueJumps, second.trueJumps),
812 Code.mergeChains(falseJumps, second.falseJumps));
813 if (markBranches) result.tree = tree.falsepart;
814 return result;
815 } else {
816 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
817 if (markBranches) result.tree = _tree;
818 return result;
819 }
820 }
822 /** Visitor method: generate code for an expression, catching and reporting
823 * any completion failures.
824 * @param tree The expression to be visited.
825 * @param pt The expression's expected type (proto-type).
826 */
827 public Item genExpr(JCTree tree, Type pt) {
828 Type prevPt = this.pt;
829 try {
830 if (tree.type.constValue() != null) {
831 // Short circuit any expressions which are constants
832 checkStringConstant(tree.pos(), tree.type.constValue());
833 result = items.makeImmediateItem(tree.type, tree.type.constValue());
834 } else {
835 this.pt = pt;
836 tree.accept(this);
837 }
838 return result.coerce(pt);
839 } catch (CompletionFailure ex) {
840 chk.completionError(tree.pos(), ex);
841 code.state.stacksize = 1;
842 return items.makeStackItem(pt);
843 } finally {
844 this.pt = prevPt;
845 }
846 }
848 /** Derived visitor method: generate code for a list of method arguments.
849 * @param trees The argument expressions to be visited.
850 * @param pts The expression's expected types (i.e. the formal parameter
851 * types of the invoked method).
852 */
853 public void genArgs(List<JCExpression> trees, List<Type> pts) {
854 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
855 genExpr(l.head, pts.head).load();
856 pts = pts.tail;
857 }
858 // require lists be of same length
859 assert pts.isEmpty();
860 }
862 /* ************************************************************************
863 * Visitor methods for statements and definitions
864 *************************************************************************/
866 /** Thrown when the byte code size exceeds limit.
867 */
868 public static class CodeSizeOverflow extends RuntimeException {
869 private static final long serialVersionUID = 0;
870 public CodeSizeOverflow() {}
871 }
873 public void visitMethodDef(JCMethodDecl tree) {
874 // Create a new local environment that points pack at method
875 // definition.
876 Env<GenContext> localEnv = env.dup(tree);
877 localEnv.enclMethod = tree;
879 // The expected type of every return statement in this method
880 // is the method's return type.
881 this.pt = tree.sym.erasure(types).getReturnType();
883 checkDimension(tree.pos(), tree.sym.erasure(types));
884 genMethod(tree, localEnv, false);
885 }
886 //where
887 /** Generate code for a method.
888 * @param tree The tree representing the method definition.
889 * @param env The environment current for the method body.
890 * @param fatcode A flag that indicates whether all jumps are
891 * within 32K. We first invoke this method under
892 * the assumption that fatcode == false, i.e. all
893 * jumps are within 32K. If this fails, fatcode
894 * is set to true and we try again.
895 */
896 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
897 MethodSymbol meth = tree.sym;
898 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
899 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) +
900 (((tree.mods.flags & STATIC) == 0 || meth.isConstructor()) ? 1 : 0) >
901 ClassFile.MAX_PARAMETERS) {
902 log.error(tree.pos(), "limit.parameters");
903 nerrs++;
904 }
906 else if (tree.body != null) {
907 // Create a new code structure and initialize it.
908 int startpcCrt = initCode(tree, env, fatcode);
910 try {
911 genStat(tree.body, env);
912 } catch (CodeSizeOverflow e) {
913 // Failed due to code limit, try again with jsr/ret
914 startpcCrt = initCode(tree, env, fatcode);
915 genStat(tree.body, env);
916 }
918 if (code.state.stacksize != 0) {
919 log.error(tree.body.pos(), "stack.sim.error", tree);
920 throw new AssertionError();
921 }
923 // If last statement could complete normally, insert a
924 // return at the end.
925 if (code.isAlive()) {
926 code.statBegin(TreeInfo.endPos(tree.body));
927 if (env.enclMethod == null ||
928 env.enclMethod.sym.type.getReturnType().tag == VOID) {
929 code.emitop0(return_);
930 } else {
931 // sometime dead code seems alive (4415991);
932 // generate a small loop instead
933 int startpc = code.entryPoint();
934 CondItem c = items.makeCondItem(goto_);
935 code.resolve(c.jumpTrue(), startpc);
936 }
937 }
938 if (genCrt)
939 code.crt.put(tree.body,
940 CRT_BLOCK,
941 startpcCrt,
942 code.curPc());
944 code.endScopes(0);
946 // If we exceeded limits, panic
947 if (code.checkLimits(tree.pos(), log)) {
948 nerrs++;
949 return;
950 }
952 // If we generated short code but got a long jump, do it again
953 // with fatCode = true.
954 if (!fatcode && code.fatcode) genMethod(tree, env, true);
956 // Clean up
957 if(stackMap == StackMapFormat.JSR202) {
958 code.lastFrame = null;
959 code.frameBeforeLast = null;
960 }
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.getTag() != JCTree.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 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 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 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 tryEnv.info.gaps.length() % 2 == 0;
1332 tryEnv.info.gaps.append(code.curPc());
1333 } else {
1334 assert 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 }
1440 // Resolve all breaks.
1441 code.resolve(exitChain);
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 List<JCExpression> subClauses = TreeInfo.isMultiCatch(tree) ?
1458 ((JCTypeDisjoint)tree.param.vartype).components :
1459 List.of(tree.param.vartype);
1460 for (JCExpression subCatch : subClauses) {
1461 int catchType = makeRef(tree.pos(), subCatch.type);
1462 List<Integer> lGaps = gaps;
1463 while (lGaps.nonEmpty()) {
1464 int end = lGaps.head.intValue();
1465 registerCatch(tree.pos(),
1466 startpc, end, code.curPc(),
1467 catchType);
1468 lGaps = lGaps.tail;
1469 startpc = lGaps.head.intValue();
1470 lGaps = lGaps.tail;
1471 }
1472 if (startpc < endpc)
1473 registerCatch(tree.pos(),
1474 startpc, endpc, code.curPc(),
1475 catchType);
1476 }
1477 VarSymbol exparam = tree.param.sym;
1478 code.statBegin(tree.pos);
1479 code.markStatBegin();
1480 int limit = code.nextreg;
1481 int exlocal = code.newLocal(exparam);
1482 items.makeLocalItem(exparam).store();
1483 code.statBegin(TreeInfo.firstStatPos(tree.body));
1484 genStat(tree.body, env, CRT_BLOCK);
1485 code.endScopes(limit);
1486 code.statBegin(TreeInfo.endPos(tree.body));
1487 }
1488 }
1490 /** Register a catch clause in the "Exceptions" code-attribute.
1491 */
1492 void registerCatch(DiagnosticPosition pos,
1493 int startpc, int endpc,
1494 int handler_pc, int catch_type) {
1495 if (startpc != endpc) {
1496 char startpc1 = (char)startpc;
1497 char endpc1 = (char)endpc;
1498 char handler_pc1 = (char)handler_pc;
1499 if (startpc1 == startpc &&
1500 endpc1 == endpc &&
1501 handler_pc1 == handler_pc) {
1502 code.addCatch(startpc1, endpc1, handler_pc1,
1503 (char)catch_type);
1504 } else {
1505 if (!useJsrLocally && !target.generateStackMapTable()) {
1506 useJsrLocally = true;
1507 throw new CodeSizeOverflow();
1508 } else {
1509 log.error(pos, "limit.code.too.large.for.try.stmt");
1510 nerrs++;
1511 }
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 JCTree.POSTINC:
1628 ((JCUnary) e).setTag(JCTree.PREINC);
1629 break;
1630 case JCTree.POSTDEC:
1631 ((JCUnary) e).setTag(JCTree.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 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 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 setTypeAnnotationPositions(tree.pos);
1682 // Generate code for method.
1683 Item m = genExpr(tree.meth, methodType);
1684 // Generate code for all arguments, where the expected types are
1685 // the parameters of the method's external type (that is, any implicit
1686 // outer instance of a super(...) call appears as first parameter).
1687 genArgs(tree.args,
1688 TreeInfo.symbol(tree.meth).externalType(types).getParameterTypes());
1689 result = m.invoke();
1690 }
1692 public void visitConditional(JCConditional tree) {
1693 Chain thenExit = null;
1694 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
1695 Chain elseChain = c.jumpFalse();
1696 if (!c.isFalse()) {
1697 code.resolve(c.trueJumps);
1698 int startpc = genCrt ? code.curPc() : 0;
1699 genExpr(tree.truepart, pt).load();
1700 code.state.forceStackTop(tree.type);
1701 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
1702 startpc, code.curPc());
1703 thenExit = code.branch(goto_);
1704 }
1705 if (elseChain != null) {
1706 code.resolve(elseChain);
1707 int startpc = genCrt ? code.curPc() : 0;
1708 genExpr(tree.falsepart, pt).load();
1709 code.state.forceStackTop(tree.type);
1710 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
1711 startpc, code.curPc());
1712 }
1713 code.resolve(thenExit);
1714 result = items.makeStackItem(pt);
1715 }
1717 private void setTypeAnnotationPositions(int treePos) {
1718 MethodSymbol meth = code.meth;
1720 for (Attribute.TypeCompound ta : meth.typeAnnotations) {
1721 if (ta.position.pos == treePos) {
1722 ta.position.offset = code.cp;
1723 ta.position.lvarOffset = new int[] { code.cp };
1724 ta.position.isValidOffset = true;
1725 }
1726 }
1728 if (code.meth.getKind() != ElementKind.CONSTRUCTOR
1729 && code.meth.getKind() != ElementKind.STATIC_INIT)
1730 return;
1732 for (Attribute.TypeCompound ta : meth.owner.typeAnnotations) {
1733 if (ta.position.pos == treePos) {
1734 ta.position.offset = code.cp;
1735 ta.position.lvarOffset = new int[] { code.cp };
1736 ta.position.isValidOffset = true;
1737 }
1738 }
1740 ClassSymbol clazz = meth.enclClass();
1741 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
1742 if (!s.getKind().isField())
1743 continue;
1744 for (Attribute.TypeCompound ta : s.typeAnnotations) {
1745 if (ta.position.pos == treePos) {
1746 ta.position.offset = code.cp;
1747 ta.position.lvarOffset = new int[] { code.cp };
1748 ta.position.isValidOffset = true;
1749 }
1750 }
1751 }
1752 }
1754 public void visitNewClass(JCNewClass tree) {
1755 // Enclosing instances or anonymous classes should have been eliminated
1756 // by now.
1757 assert tree.encl == null && tree.def == null;
1758 setTypeAnnotationPositions(tree.pos);
1760 code.emitop2(new_, makeRef(tree.pos(), tree.type));
1761 code.emitop0(dup);
1763 // Generate code for all arguments, where the expected types are
1764 // the parameters of the constructor's external type (that is,
1765 // any implicit outer instance appears as first parameter).
1766 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
1768 items.makeMemberItem(tree.constructor, true).invoke();
1769 result = items.makeStackItem(tree.type);
1770 }
1772 public void visitNewArray(JCNewArray tree) {
1773 setTypeAnnotationPositions(tree.pos);
1775 if (tree.elems != null) {
1776 Type elemtype = types.elemtype(tree.type);
1777 loadIntConst(tree.elems.length());
1778 Item arr = makeNewArray(tree.pos(), tree.type, 1);
1779 int i = 0;
1780 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
1781 arr.duplicate();
1782 loadIntConst(i);
1783 i++;
1784 genExpr(l.head, elemtype).load();
1785 items.makeIndexedItem(elemtype).store();
1786 }
1787 result = arr;
1788 } else {
1789 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1790 genExpr(l.head, syms.intType).load();
1791 }
1792 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
1793 }
1794 }
1795 //where
1796 /** Generate code to create an array with given element type and number
1797 * of dimensions.
1798 */
1799 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
1800 Type elemtype = types.elemtype(type);
1801 if (types.dimensions(elemtype) + ndims > ClassFile.MAX_DIMENSIONS) {
1802 log.error(pos, "limit.dimensions");
1803 nerrs++;
1804 }
1805 int elemcode = Code.arraycode(elemtype);
1806 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
1807 code.emitAnewarray(makeRef(pos, elemtype), type);
1808 } else if (elemcode == 1) {
1809 code.emitMultianewarray(ndims, makeRef(pos, type), type);
1810 } else {
1811 code.emitNewarray(elemcode, type);
1812 }
1813 return items.makeStackItem(type);
1814 }
1816 public void visitParens(JCParens tree) {
1817 result = genExpr(tree.expr, tree.expr.type);
1818 }
1820 public void visitAssign(JCAssign tree) {
1821 Item l = genExpr(tree.lhs, tree.lhs.type);
1822 genExpr(tree.rhs, tree.lhs.type).load();
1823 result = items.makeAssignItem(l);
1824 }
1826 public void visitAssignop(JCAssignOp tree) {
1827 OperatorSymbol operator = (OperatorSymbol) tree.operator;
1828 Item l;
1829 if (operator.opcode == string_add) {
1830 // Generate code to make a string buffer
1831 makeStringBuffer(tree.pos());
1833 // Generate code for first string, possibly save one
1834 // copy under buffer
1835 l = genExpr(tree.lhs, tree.lhs.type);
1836 if (l.width() > 0) {
1837 code.emitop0(dup_x1 + 3 * (l.width() - 1));
1838 }
1840 // Load first string and append to buffer.
1841 l.load();
1842 appendString(tree.lhs);
1844 // Append all other strings to buffer.
1845 appendStrings(tree.rhs);
1847 // Convert buffer to string.
1848 bufferToString(tree.pos());
1849 } else {
1850 // Generate code for first expression
1851 l = genExpr(tree.lhs, tree.lhs.type);
1853 // If we have an increment of -32768 to +32767 of a local
1854 // int variable we can use an incr instruction instead of
1855 // proceeding further.
1856 if ((tree.getTag() == JCTree.PLUS_ASG || tree.getTag() == JCTree.MINUS_ASG) &&
1857 l instanceof LocalItem &&
1858 tree.lhs.type.tag <= INT &&
1859 tree.rhs.type.tag <= INT &&
1860 tree.rhs.type.constValue() != null) {
1861 int ival = ((Number) tree.rhs.type.constValue()).intValue();
1862 if (tree.getTag() == JCTree.MINUS_ASG) ival = -ival;
1863 ((LocalItem)l).incr(ival);
1864 result = l;
1865 return;
1866 }
1867 // Otherwise, duplicate expression, load one copy
1868 // and complete binary operation.
1869 l.duplicate();
1870 l.coerce(operator.type.getParameterTypes().head).load();
1871 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
1872 }
1873 result = items.makeAssignItem(l);
1874 }
1876 public void visitUnary(JCUnary tree) {
1877 OperatorSymbol operator = (OperatorSymbol)tree.operator;
1878 if (tree.getTag() == JCTree.NOT) {
1879 CondItem od = genCond(tree.arg, false);
1880 result = od.negate();
1881 } else {
1882 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
1883 switch (tree.getTag()) {
1884 case JCTree.POS:
1885 result = od.load();
1886 break;
1887 case JCTree.NEG:
1888 result = od.load();
1889 code.emitop0(operator.opcode);
1890 break;
1891 case JCTree.COMPL:
1892 result = od.load();
1893 emitMinusOne(od.typecode);
1894 code.emitop0(operator.opcode);
1895 break;
1896 case JCTree.PREINC: case JCTree.PREDEC:
1897 od.duplicate();
1898 if (od instanceof LocalItem &&
1899 (operator.opcode == iadd || operator.opcode == isub)) {
1900 ((LocalItem)od).incr(tree.getTag() == JCTree.PREINC ? 1 : -1);
1901 result = od;
1902 } else {
1903 od.load();
1904 code.emitop0(one(od.typecode));
1905 code.emitop0(operator.opcode);
1906 // Perform narrowing primitive conversion if byte,
1907 // char, or short. Fix for 4304655.
1908 if (od.typecode != INTcode &&
1909 Code.truncate(od.typecode) == INTcode)
1910 code.emitop0(int2byte + od.typecode - BYTEcode);
1911 result = items.makeAssignItem(od);
1912 }
1913 break;
1914 case JCTree.POSTINC: case JCTree.POSTDEC:
1915 od.duplicate();
1916 if (od instanceof LocalItem &&
1917 (operator.opcode == iadd || operator.opcode == isub)) {
1918 Item res = od.load();
1919 ((LocalItem)od).incr(tree.getTag() == JCTree.POSTINC ? 1 : -1);
1920 result = res;
1921 } else {
1922 Item res = od.load();
1923 od.stash(od.typecode);
1924 code.emitop0(one(od.typecode));
1925 code.emitop0(operator.opcode);
1926 // Perform narrowing primitive conversion if byte,
1927 // char, or short. Fix for 4304655.
1928 if (od.typecode != INTcode &&
1929 Code.truncate(od.typecode) == INTcode)
1930 code.emitop0(int2byte + od.typecode - BYTEcode);
1931 od.store();
1932 result = res;
1933 }
1934 break;
1935 case JCTree.NULLCHK:
1936 result = od.load();
1937 code.emitop0(dup);
1938 genNullCheck(tree.pos());
1939 break;
1940 default:
1941 assert false;
1942 }
1943 }
1944 }
1946 /** Generate a null check from the object value at stack top. */
1947 private void genNullCheck(DiagnosticPosition pos) {
1948 callMethod(pos, syms.objectType, names.getClass,
1949 List.<Type>nil(), false);
1950 code.emitop0(pop);
1951 }
1953 public void visitBinary(JCBinary tree) {
1954 OperatorSymbol operator = (OperatorSymbol)tree.operator;
1955 if (operator.opcode == string_add) {
1956 // Create a string buffer.
1957 makeStringBuffer(tree.pos());
1958 // Append all strings to buffer.
1959 appendStrings(tree);
1960 // Convert buffer to string.
1961 bufferToString(tree.pos());
1962 result = items.makeStackItem(syms.stringType);
1963 } else if (tree.getTag() == JCTree.AND) {
1964 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
1965 if (!lcond.isFalse()) {
1966 Chain falseJumps = lcond.jumpFalse();
1967 code.resolve(lcond.trueJumps);
1968 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
1969 result = items.
1970 makeCondItem(rcond.opcode,
1971 rcond.trueJumps,
1972 Code.mergeChains(falseJumps,
1973 rcond.falseJumps));
1974 } else {
1975 result = lcond;
1976 }
1977 } else if (tree.getTag() == JCTree.OR) {
1978 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
1979 if (!lcond.isTrue()) {
1980 Chain trueJumps = lcond.jumpTrue();
1981 code.resolve(lcond.falseJumps);
1982 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
1983 result = items.
1984 makeCondItem(rcond.opcode,
1985 Code.mergeChains(trueJumps, rcond.trueJumps),
1986 rcond.falseJumps);
1987 } else {
1988 result = lcond;
1989 }
1990 } else {
1991 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
1992 od.load();
1993 result = completeBinop(tree.lhs, tree.rhs, operator);
1994 }
1995 }
1996 //where
1997 /** Make a new string buffer.
1998 */
1999 void makeStringBuffer(DiagnosticPosition pos) {
2000 code.emitop2(new_, makeRef(pos, stringBufferType));
2001 code.emitop0(dup);
2002 callMethod(
2003 pos, stringBufferType, names.init, List.<Type>nil(), false);
2004 }
2006 /** Append value (on tos) to string buffer (on tos - 1).
2007 */
2008 void appendString(JCTree tree) {
2009 Type t = tree.type.baseType();
2010 if (t.tag > lastBaseTag && t.tsym != syms.stringType.tsym) {
2011 t = syms.objectType;
2012 }
2013 items.makeMemberItem(getStringBufferAppend(tree, t), false).invoke();
2014 }
2015 Symbol getStringBufferAppend(JCTree tree, Type t) {
2016 assert t.constValue() == null;
2017 Symbol method = stringBufferAppend.get(t);
2018 if (method == null) {
2019 method = rs.resolveInternalMethod(tree.pos(),
2020 attrEnv,
2021 stringBufferType,
2022 names.append,
2023 List.of(t),
2024 null);
2025 stringBufferAppend.put(t, method);
2026 }
2027 return method;
2028 }
2030 /** Add all strings in tree to string buffer.
2031 */
2032 void appendStrings(JCTree tree) {
2033 tree = TreeInfo.skipParens(tree);
2034 if (tree.getTag() == JCTree.PLUS && tree.type.constValue() == null) {
2035 JCBinary op = (JCBinary) tree;
2036 if (op.operator.kind == MTH &&
2037 ((OperatorSymbol) op.operator).opcode == string_add) {
2038 appendStrings(op.lhs);
2039 appendStrings(op.rhs);
2040 return;
2041 }
2042 }
2043 genExpr(tree, tree.type).load();
2044 appendString(tree);
2045 }
2047 /** Convert string buffer on tos to string.
2048 */
2049 void bufferToString(DiagnosticPosition pos) {
2050 callMethod(
2051 pos,
2052 stringBufferType,
2053 names.toString,
2054 List.<Type>nil(),
2055 false);
2056 }
2058 /** Complete generating code for operation, with left operand
2059 * already on stack.
2060 * @param lhs The tree representing the left operand.
2061 * @param rhs The tree representing the right operand.
2062 * @param operator The operator symbol.
2063 */
2064 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2065 MethodType optype = (MethodType)operator.type;
2066 int opcode = operator.opcode;
2067 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2068 rhs.type.constValue() instanceof Number &&
2069 ((Number) rhs.type.constValue()).intValue() == 0) {
2070 opcode = opcode + (ifeq - if_icmpeq);
2071 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2072 TreeInfo.isNull(rhs)) {
2073 opcode = opcode + (if_acmp_null - if_acmpeq);
2074 } else {
2075 // The expected type of the right operand is
2076 // the second parameter type of the operator, except for
2077 // shifts with long shiftcount, where we convert the opcode
2078 // to a short shift and the expected type to int.
2079 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2080 if (opcode >= ishll && opcode <= lushrl) {
2081 opcode = opcode + (ishl - ishll);
2082 rtype = syms.intType;
2083 }
2084 // Generate code for right operand and load.
2085 genExpr(rhs, rtype).load();
2086 // If there are two consecutive opcode instructions,
2087 // emit the first now.
2088 if (opcode >= (1 << preShift)) {
2089 code.emitop0(opcode >> preShift);
2090 opcode = opcode & 0xFF;
2091 }
2092 }
2093 if (opcode >= ifeq && opcode <= if_acmpne ||
2094 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2095 return items.makeCondItem(opcode);
2096 } else {
2097 code.emitop0(opcode);
2098 return items.makeStackItem(optype.restype);
2099 }
2100 }
2102 public void visitTypeCast(JCTypeCast tree) {
2103 setTypeAnnotationPositions(tree.pos);
2104 result = genExpr(tree.expr, tree.clazz.type).load();
2105 // Additional code is only needed if we cast to a reference type
2106 // which is not statically a supertype of the expression's type.
2107 // For basic types, the coerce(...) in genExpr(...) will do
2108 // the conversion.
2109 if (tree.clazz.type.tag > lastBaseTag &&
2110 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2111 code.emitop2(checkcast, makeRef(tree.pos(), tree.clazz.type));
2112 }
2113 }
2115 public void visitWildcard(JCWildcard tree) {
2116 throw new AssertionError(this.getClass().getName());
2117 }
2119 public void visitTypeTest(JCInstanceOf tree) {
2120 setTypeAnnotationPositions(tree.pos);
2122 genExpr(tree.expr, tree.expr.type).load();
2123 code.emitop2(instanceof_, makeRef(tree.pos(), tree.clazz.type));
2124 result = items.makeStackItem(syms.booleanType);
2125 }
2127 public void visitIndexed(JCArrayAccess tree) {
2128 genExpr(tree.indexed, tree.indexed.type).load();
2129 genExpr(tree.index, syms.intType).load();
2130 result = items.makeIndexedItem(tree.type);
2131 }
2133 public void visitIdent(JCIdent tree) {
2134 Symbol sym = tree.sym;
2135 if (tree.name == names._this || tree.name == names._super) {
2136 Item res = tree.name == names._this
2137 ? items.makeThisItem()
2138 : items.makeSuperItem();
2139 if (sym.kind == MTH) {
2140 // Generate code to address the constructor.
2141 res.load();
2142 res = items.makeMemberItem(sym, true);
2143 }
2144 result = res;
2145 } else if (sym.kind == VAR && sym.owner.kind == MTH) {
2146 result = items.makeLocalItem((VarSymbol)sym);
2147 } else if ((sym.flags() & STATIC) != 0) {
2148 if (!isAccessSuper(env.enclMethod))
2149 sym = binaryQualifier(sym, env.enclClass.type);
2150 result = items.makeStaticItem(sym);
2151 } else {
2152 items.makeThisItem().load();
2153 sym = binaryQualifier(sym, env.enclClass.type);
2154 result = items.makeMemberItem(sym, (sym.flags() & PRIVATE) != 0);
2155 }
2156 }
2158 public void visitSelect(JCFieldAccess tree) {
2159 Symbol sym = tree.sym;
2161 if (tree.name == names._class) {
2162 assert target.hasClassLiterals();
2163 setTypeAnnotationPositions(tree.pos);
2164 code.emitop2(ldc2, makeRef(tree.pos(), tree.selected.type));
2165 result = items.makeStackItem(pt);
2166 return;
2167 } else if (tree.name == names.TYPE) {
2168 // Set the annotation positions for primitive class literals
2169 // (e.g. int.class) which have been converted to TYPE field
2170 // access on the corresponding boxed type (e.g. Integer.TYPE).
2171 setTypeAnnotationPositions(tree.pos);
2172 }
2174 Symbol ssym = TreeInfo.symbol(tree.selected);
2176 // Are we selecting via super?
2177 boolean selectSuper =
2178 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2180 // Are we accessing a member of the superclass in an access method
2181 // resulting from a qualified super?
2182 boolean accessSuper = isAccessSuper(env.enclMethod);
2184 Item base = (selectSuper)
2185 ? items.makeSuperItem()
2186 : genExpr(tree.selected, tree.selected.type);
2188 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2189 // We are seeing a variable that is constant but its selecting
2190 // expression is not.
2191 if ((sym.flags() & STATIC) != 0) {
2192 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2193 base = base.load();
2194 base.drop();
2195 } else {
2196 base.load();
2197 genNullCheck(tree.selected.pos());
2198 }
2199 result = items.
2200 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2201 } else if (allowInvokedynamic && sym.kind == MTH && ssym == syms.invokeDynamicType.tsym) {
2202 base.drop();
2203 result = items.makeDynamicItem(sym);
2204 } else {
2205 if (!accessSuper)
2206 sym = binaryQualifier(sym, tree.selected.type);
2207 if ((sym.flags() & STATIC) != 0) {
2208 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2209 base = base.load();
2210 base.drop();
2211 result = items.makeStaticItem(sym);
2212 } else {
2213 base.load();
2214 if (sym == syms.lengthVar) {
2215 code.emitop0(arraylength);
2216 result = items.makeStackItem(syms.intType);
2217 } else {
2218 result = items.
2219 makeMemberItem(sym,
2220 (sym.flags() & PRIVATE) != 0 ||
2221 selectSuper || accessSuper);
2222 }
2223 }
2224 }
2225 }
2227 public void visitLiteral(JCLiteral tree) {
2228 if (tree.type.tag == TypeTags.BOT) {
2229 code.emitop0(aconst_null);
2230 if (types.dimensions(pt) > 1) {
2231 code.emitop2(checkcast, makeRef(tree.pos(), pt));
2232 result = items.makeStackItem(pt);
2233 } else {
2234 result = items.makeStackItem(tree.type);
2235 }
2236 }
2237 else
2238 result = items.makeImmediateItem(tree.type, tree.value);
2239 }
2241 public void visitLetExpr(LetExpr tree) {
2242 int limit = code.nextreg;
2243 genStats(tree.defs, env);
2244 result = genExpr(tree.expr, tree.expr.type).load();
2245 code.endScopes(limit);
2246 }
2248 /* ************************************************************************
2249 * main method
2250 *************************************************************************/
2252 /** Generate code for a class definition.
2253 * @param env The attribution environment that belongs to the
2254 * outermost class containing this class definition.
2255 * We need this for resolving some additional symbols.
2256 * @param cdef The tree representing the class definition.
2257 * @return True if code is generated with no errors.
2258 */
2259 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2260 try {
2261 attrEnv = env;
2262 ClassSymbol c = cdef.sym;
2263 this.toplevel = env.toplevel;
2264 this.endPositions = toplevel.endPositions;
2265 // If this is a class definition requiring Miranda methods,
2266 // add them.
2267 if (generateIproxies &&
2268 (c.flags() & (INTERFACE|ABSTRACT)) == ABSTRACT
2269 && !allowGenerics // no Miranda methods available with generics
2270 )
2271 implementInterfaceMethods(c);
2272 cdef.defs = normalizeDefs(cdef.defs, c);
2273 c.pool = pool;
2274 pool.reset();
2275 Env<GenContext> localEnv =
2276 new Env<GenContext>(cdef, new GenContext());
2277 localEnv.toplevel = env.toplevel;
2278 localEnv.enclClass = cdef;
2279 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2280 genDef(l.head, localEnv);
2281 }
2282 if (pool.numEntries() > Pool.MAX_ENTRIES) {
2283 log.error(cdef.pos(), "limit.pool");
2284 nerrs++;
2285 }
2286 if (nerrs != 0) {
2287 // if errors, discard code
2288 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2289 if (l.head.getTag() == JCTree.METHODDEF)
2290 ((JCMethodDecl) l.head).sym.code = null;
2291 }
2292 }
2293 cdef.defs = List.nil(); // discard trees
2294 return nerrs == 0;
2295 } finally {
2296 // note: this method does NOT support recursion.
2297 attrEnv = null;
2298 this.env = null;
2299 toplevel = null;
2300 endPositions = null;
2301 nerrs = 0;
2302 }
2303 }
2305 /* ************************************************************************
2306 * Auxiliary classes
2307 *************************************************************************/
2309 /** An abstract class for finalizer generation.
2310 */
2311 abstract class GenFinalizer {
2312 /** Generate code to clean up when unwinding. */
2313 abstract void gen();
2315 /** Generate code to clean up at last. */
2316 abstract void genLast();
2318 /** Does this finalizer have some nontrivial cleanup to perform? */
2319 boolean hasFinalizer() { return true; }
2320 }
2322 /** code generation contexts,
2323 * to be used as type parameter for environments.
2324 */
2325 static class GenContext {
2327 /** A chain for all unresolved jumps that exit the current environment.
2328 */
2329 Chain exit = null;
2331 /** A chain for all unresolved jumps that continue in the
2332 * current environment.
2333 */
2334 Chain cont = null;
2336 /** A closure that generates the finalizer of the current environment.
2337 * Only set for Synchronized and Try contexts.
2338 */
2339 GenFinalizer finalize = null;
2341 /** Is this a switch statement? If so, allocate registers
2342 * even when the variable declaration is unreachable.
2343 */
2344 boolean isSwitch = false;
2346 /** A list buffer containing all gaps in the finalizer range,
2347 * where a catch all exception should not apply.
2348 */
2349 ListBuffer<Integer> gaps = null;
2351 /** Add given chain to exit chain.
2352 */
2353 void addExit(Chain c) {
2354 exit = Code.mergeChains(c, exit);
2355 }
2357 /** Add given chain to cont chain.
2358 */
2359 void addCont(Chain c) {
2360 cont = Code.mergeChains(c, cont);
2361 }
2362 }
2363 }
