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src/share/classes/com/sun/tools/javac/jvm/Gen.java@af8417e590f4
src/share/classes/com/sun/tools/javac/jvm/Gen.java
Sun, 17 Feb 2013 16:44:55 -0500
- author
- dholmes
- date
- Sun, 17 Feb 2013 16:44:55 -0500
- changeset 1571
- af8417e590f4
- parent 1555
- 762d0af062f5
- child 1670
- 29c6984a1673
- permissions
- -rw-r--r--
Merge
1 /*
2 * Copyright (c) 1999, 2013, 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.tree.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.TypeTag.*;
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.Option.*;
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;
74 private final Lower lower;
76 /** Switch: GJ mode?
77 */
78 private final boolean allowGenerics;
80 /** Set when Miranda method stubs are to be generated. */
81 private final boolean generateIproxies;
83 /** Format of stackmap tables to be generated. */
84 private final Code.StackMapFormat stackMap;
86 /** A type that serves as the expected type for all method expressions.
87 */
88 private final Type methodType;
90 public static Gen instance(Context context) {
91 Gen instance = context.get(genKey);
92 if (instance == null)
93 instance = new Gen(context);
94 return instance;
95 }
97 /* Constant pool, reset by genClass.
98 */
99 private Pool pool;
101 protected Gen(Context context) {
102 context.put(genKey, this);
104 names = Names.instance(context);
105 log = Log.instance(context);
106 syms = Symtab.instance(context);
107 chk = Check.instance(context);
108 rs = Resolve.instance(context);
109 make = TreeMaker.instance(context);
110 target = Target.instance(context);
111 types = Types.instance(context);
112 methodType = new MethodType(null, null, null, syms.methodClass);
113 allowGenerics = Source.instance(context).allowGenerics();
114 stringBufferType = target.useStringBuilder()
115 ? syms.stringBuilderType
116 : syms.stringBufferType;
117 stringBufferAppend = new HashMap<Type,Symbol>();
118 accessDollar = names.
119 fromString("access" + target.syntheticNameChar());
120 lower = Lower.instance(context);
122 Options options = Options.instance(context);
123 lineDebugInfo =
124 options.isUnset(G_CUSTOM) ||
125 options.isSet(G_CUSTOM, "lines");
126 varDebugInfo =
127 options.isUnset(G_CUSTOM)
128 ? options.isSet(G)
129 : options.isSet(G_CUSTOM, "vars");
130 genCrt = options.isSet(XJCOV);
131 debugCode = options.isSet("debugcode");
132 allowInvokedynamic = target.hasInvokedynamic() || options.isSet("invokedynamic");
133 pool = new Pool(types);
135 generateIproxies =
136 target.requiresIproxy() ||
137 options.isSet("miranda");
139 if (target.generateStackMapTable()) {
140 // ignore cldc because we cannot have both stackmap formats
141 this.stackMap = StackMapFormat.JSR202;
142 } else {
143 if (target.generateCLDCStackmap()) {
144 this.stackMap = StackMapFormat.CLDC;
145 } else {
146 this.stackMap = StackMapFormat.NONE;
147 }
148 }
150 // by default, avoid jsr's for simple finalizers
151 int setjsrlimit = 50;
152 String jsrlimitString = options.get("jsrlimit");
153 if (jsrlimitString != null) {
154 try {
155 setjsrlimit = Integer.parseInt(jsrlimitString);
156 } catch (NumberFormatException ex) {
157 // ignore ill-formed numbers for jsrlimit
158 }
159 }
160 this.jsrlimit = setjsrlimit;
161 this.useJsrLocally = false; // reset in visitTry
162 }
164 /** Switches
165 */
166 private final boolean lineDebugInfo;
167 private final boolean varDebugInfo;
168 private final boolean genCrt;
169 private final boolean debugCode;
170 private final boolean allowInvokedynamic;
172 /** Default limit of (approximate) size of finalizer to inline.
173 * Zero means always use jsr. 100 or greater means never use
174 * jsr.
175 */
176 private final int jsrlimit;
178 /** True if jsr is used.
179 */
180 private boolean useJsrLocally;
182 /** Code buffer, set by genMethod.
183 */
184 private Code code;
186 /** Items structure, set by genMethod.
187 */
188 private Items items;
190 /** Environment for symbol lookup, set by genClass
191 */
192 private Env<AttrContext> attrEnv;
194 /** The top level tree.
195 */
196 private JCCompilationUnit toplevel;
198 /** The number of code-gen errors in this class.
199 */
200 private int nerrs = 0;
202 /** An object containing mappings of syntax trees to their
203 * ending source positions.
204 */
205 EndPosTable endPosTable;
207 /** Generate code to load an integer constant.
208 * @param n The integer to be loaded.
209 */
210 void loadIntConst(int n) {
211 items.makeImmediateItem(syms.intType, n).load();
212 }
214 /** The opcode that loads a zero constant of a given type code.
215 * @param tc The given type code (@see ByteCode).
216 */
217 public static int zero(int tc) {
218 switch(tc) {
219 case INTcode: case BYTEcode: case SHORTcode: case CHARcode:
220 return iconst_0;
221 case LONGcode:
222 return lconst_0;
223 case FLOATcode:
224 return fconst_0;
225 case DOUBLEcode:
226 return dconst_0;
227 default:
228 throw new AssertionError("zero");
229 }
230 }
232 /** The opcode that loads a one constant of a given type code.
233 * @param tc The given type code (@see ByteCode).
234 */
235 public static int one(int tc) {
236 return zero(tc) + 1;
237 }
239 /** Generate code to load -1 of the given type code (either int or long).
240 * @param tc The given type code (@see ByteCode).
241 */
242 void emitMinusOne(int tc) {
243 if (tc == LONGcode) {
244 items.makeImmediateItem(syms.longType, new Long(-1)).load();
245 } else {
246 code.emitop0(iconst_m1);
247 }
248 }
250 /** Construct a symbol to reflect the qualifying type that should
251 * appear in the byte code as per JLS 13.1.
252 *
253 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except
254 * for those cases where we need to work around VM bugs).
255 *
256 * For {@literal target <= 1.1}: If qualified variable or method is defined in a
257 * non-accessible class, clone it with the qualifier class as owner.
258 *
259 * @param sym The accessed symbol
260 * @param site The qualifier's type.
261 */
262 Symbol binaryQualifier(Symbol sym, Type site) {
264 if (site.hasTag(ARRAY)) {
265 if (sym == syms.lengthVar ||
266 sym.owner != syms.arrayClass)
267 return sym;
268 // array clone can be qualified by the array type in later targets
269 Symbol qualifier = target.arrayBinaryCompatibility()
270 ? new ClassSymbol(Flags.PUBLIC, site.tsym.name,
271 site, syms.noSymbol)
272 : syms.objectType.tsym;
273 return sym.clone(qualifier);
274 }
276 if (sym.owner == site.tsym ||
277 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) {
278 return sym;
279 }
280 if (!target.obeyBinaryCompatibility())
281 return rs.isAccessible(attrEnv, (TypeSymbol)sym.owner)
282 ? sym
283 : sym.clone(site.tsym);
285 if (!target.interfaceFieldsBinaryCompatibility()) {
286 if ((sym.owner.flags() & INTERFACE) != 0 && sym.kind == VAR)
287 return sym;
288 }
290 // leave alone methods inherited from Object
291 // JLS 13.1.
292 if (sym.owner == syms.objectType.tsym)
293 return sym;
295 if (!target.interfaceObjectOverridesBinaryCompatibility()) {
296 if ((sym.owner.flags() & INTERFACE) != 0 &&
297 syms.objectType.tsym.members().lookup(sym.name).scope != null)
298 return sym;
299 }
301 return sym.clone(site.tsym);
302 }
304 /** Insert a reference to given type in the constant pool,
305 * checking for an array with too many dimensions;
306 * return the reference's index.
307 * @param type The type for which a reference is inserted.
308 */
309 int makeRef(DiagnosticPosition pos, Type type) {
310 checkDimension(pos, type);
311 return pool.put(type.hasTag(CLASS) ? (Object)type.tsym : (Object)type);
312 }
314 /** Check if the given type is an array with too many dimensions.
315 */
316 private void checkDimension(DiagnosticPosition pos, Type t) {
317 switch (t.getTag()) {
318 case METHOD:
319 checkDimension(pos, t.getReturnType());
320 for (List<Type> args = t.getParameterTypes(); args.nonEmpty(); args = args.tail)
321 checkDimension(pos, args.head);
322 break;
323 case ARRAY:
324 if (types.dimensions(t) > ClassFile.MAX_DIMENSIONS) {
325 log.error(pos, "limit.dimensions");
326 nerrs++;
327 }
328 break;
329 default:
330 break;
331 }
332 }
334 /** Create a tempory variable.
335 * @param type The variable's type.
336 */
337 LocalItem makeTemp(Type type) {
338 VarSymbol v = new VarSymbol(Flags.SYNTHETIC,
339 names.empty,
340 type,
341 env.enclMethod.sym);
342 code.newLocal(v);
343 return items.makeLocalItem(v);
344 }
346 /** Generate code to call a non-private method or constructor.
347 * @param pos Position to be used for error reporting.
348 * @param site The type of which the method is a member.
349 * @param name The method's name.
350 * @param argtypes The method's argument types.
351 * @param isStatic A flag that indicates whether we call a
352 * static or instance method.
353 */
354 void callMethod(DiagnosticPosition pos,
355 Type site, Name name, List<Type> argtypes,
356 boolean isStatic) {
357 Symbol msym = rs.
358 resolveInternalMethod(pos, attrEnv, site, name, argtypes, null);
359 if (isStatic) items.makeStaticItem(msym).invoke();
360 else items.makeMemberItem(msym, name == names.init).invoke();
361 }
363 /** Is the given method definition an access method
364 * resulting from a qualified super? This is signified by an odd
365 * access code.
366 */
367 private boolean isAccessSuper(JCMethodDecl enclMethod) {
368 return
369 (enclMethod.mods.flags & SYNTHETIC) != 0 &&
370 isOddAccessName(enclMethod.name);
371 }
373 /** Does given name start with "access$" and end in an odd digit?
374 */
375 private boolean isOddAccessName(Name name) {
376 return
377 name.startsWith(accessDollar) &&
378 (name.getByteAt(name.getByteLength() - 1) & 1) == 1;
379 }
381 /* ************************************************************************
382 * Non-local exits
383 *************************************************************************/
385 /** Generate code to invoke the finalizer associated with given
386 * environment.
387 * Any calls to finalizers are appended to the environments `cont' chain.
388 * Mark beginning of gap in catch all range for finalizer.
389 */
390 void genFinalizer(Env<GenContext> env) {
391 if (code.isAlive() && env.info.finalize != null)
392 env.info.finalize.gen();
393 }
395 /** Generate code to call all finalizers of structures aborted by
396 * a non-local
397 * exit. Return target environment of the non-local exit.
398 * @param target The tree representing the structure that's aborted
399 * @param env The environment current at the non-local exit.
400 */
401 Env<GenContext> unwind(JCTree target, Env<GenContext> env) {
402 Env<GenContext> env1 = env;
403 while (true) {
404 genFinalizer(env1);
405 if (env1.tree == target) break;
406 env1 = env1.next;
407 }
408 return env1;
409 }
411 /** Mark end of gap in catch-all range for finalizer.
412 * @param env the environment which might contain the finalizer
413 * (if it does, env.info.gaps != null).
414 */
415 void endFinalizerGap(Env<GenContext> env) {
416 if (env.info.gaps != null && env.info.gaps.length() % 2 == 1)
417 env.info.gaps.append(code.curPc());
418 }
420 /** Mark end of all gaps in catch-all ranges for finalizers of environments
421 * lying between, and including to two environments.
422 * @param from the most deeply nested environment to mark
423 * @param to the least deeply nested environment to mark
424 */
425 void endFinalizerGaps(Env<GenContext> from, Env<GenContext> to) {
426 Env<GenContext> last = null;
427 while (last != to) {
428 endFinalizerGap(from);
429 last = from;
430 from = from.next;
431 }
432 }
434 /** Do any of the structures aborted by a non-local exit have
435 * finalizers that require an empty stack?
436 * @param target The tree representing the structure that's aborted
437 * @param env The environment current at the non-local exit.
438 */
439 boolean hasFinally(JCTree target, Env<GenContext> env) {
440 while (env.tree != target) {
441 if (env.tree.hasTag(TRY) && env.info.finalize.hasFinalizer())
442 return true;
443 env = env.next;
444 }
445 return false;
446 }
448 /* ************************************************************************
449 * Normalizing class-members.
450 *************************************************************************/
452 /** Distribute member initializer code into constructors and {@code <clinit>}
453 * method.
454 * @param defs The list of class member declarations.
455 * @param c The enclosing class.
456 */
457 List<JCTree> normalizeDefs(List<JCTree> defs, ClassSymbol c) {
458 ListBuffer<JCStatement> initCode = new ListBuffer<JCStatement>();
459 ListBuffer<JCStatement> clinitCode = new ListBuffer<JCStatement>();
460 ListBuffer<JCTree> methodDefs = new ListBuffer<JCTree>();
461 // Sort definitions into three listbuffers:
462 // - initCode for instance initializers
463 // - clinitCode for class initializers
464 // - methodDefs for method definitions
465 for (List<JCTree> l = defs; l.nonEmpty(); l = l.tail) {
466 JCTree def = l.head;
467 switch (def.getTag()) {
468 case BLOCK:
469 JCBlock block = (JCBlock)def;
470 if ((block.flags & STATIC) != 0)
471 clinitCode.append(block);
472 else
473 initCode.append(block);
474 break;
475 case METHODDEF:
476 methodDefs.append(def);
477 break;
478 case VARDEF:
479 JCVariableDecl vdef = (JCVariableDecl) def;
480 VarSymbol sym = vdef.sym;
481 checkDimension(vdef.pos(), sym.type);
482 if (vdef.init != null) {
483 if ((sym.flags() & STATIC) == 0) {
484 // Always initialize instance variables.
485 JCStatement init = make.at(vdef.pos()).
486 Assignment(sym, vdef.init);
487 initCode.append(init);
488 endPosTable.replaceTree(vdef, init);
489 } else if (sym.getConstValue() == null) {
490 // Initialize class (static) variables only if
491 // they are not compile-time constants.
492 JCStatement init = make.at(vdef.pos).
493 Assignment(sym, vdef.init);
494 clinitCode.append(init);
495 endPosTable.replaceTree(vdef, init);
496 } else {
497 checkStringConstant(vdef.init.pos(), sym.getConstValue());
498 }
499 }
500 break;
501 default:
502 Assert.error();
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 | (c.flags() & STRICTFP),
517 names.clinit,
518 new MethodType(
519 List.<Type>nil(), syms.voidType,
520 List.<Type>nil(), syms.methodClass),
521 c);
522 c.members().enter(clinit);
523 List<JCStatement> clinitStats = clinitCode.toList();
524 JCBlock block = make.at(clinitStats.head.pos()).Block(0, clinitStats);
525 block.endpos = TreeInfo.endPos(clinitStats.last());
526 methodDefs.append(make.MethodDef(clinit, block));
527 }
528 // Return all method definitions.
529 return methodDefs.toList();
530 }
532 /** Check a constant value and report if it is a string that is
533 * too large.
534 */
535 private void checkStringConstant(DiagnosticPosition pos, Object constValue) {
536 if (nerrs != 0 || // only complain about a long string once
537 constValue == null ||
538 !(constValue instanceof String) ||
539 ((String)constValue).length() < Pool.MAX_STRING_LENGTH)
540 return;
541 log.error(pos, "limit.string");
542 nerrs++;
543 }
545 /** Insert instance initializer code into initial constructor.
546 * @param md The tree potentially representing a
547 * constructor's definition.
548 * @param initCode The list of instance initializer statements.
549 */
550 void normalizeMethod(JCMethodDecl md, List<JCStatement> initCode) {
551 if (md.name == names.init && TreeInfo.isInitialConstructor(md)) {
552 // We are seeing a constructor that does not call another
553 // constructor of the same class.
554 List<JCStatement> stats = md.body.stats;
555 ListBuffer<JCStatement> newstats = new ListBuffer<JCStatement>();
557 if (stats.nonEmpty()) {
558 // Copy initializers of synthetic variables generated in
559 // the translation of inner classes.
560 while (TreeInfo.isSyntheticInit(stats.head)) {
561 newstats.append(stats.head);
562 stats = stats.tail;
563 }
564 // Copy superclass constructor call
565 newstats.append(stats.head);
566 stats = stats.tail;
567 // Copy remaining synthetic initializers.
568 while (stats.nonEmpty() &&
569 TreeInfo.isSyntheticInit(stats.head)) {
570 newstats.append(stats.head);
571 stats = stats.tail;
572 }
573 // Now insert the initializer code.
574 newstats.appendList(initCode);
575 // And copy all remaining statements.
576 while (stats.nonEmpty()) {
577 newstats.append(stats.head);
578 stats = stats.tail;
579 }
580 }
581 md.body.stats = newstats.toList();
582 if (md.body.endpos == Position.NOPOS)
583 md.body.endpos = TreeInfo.endPos(md.body.stats.last());
584 }
585 }
587 /* ********************************************************************
588 * Adding miranda methods
589 *********************************************************************/
591 /** Add abstract methods for all methods defined in one of
592 * the interfaces of a given class,
593 * provided they are not already implemented in the class.
594 *
595 * @param c The class whose interfaces are searched for methods
596 * for which Miranda methods should be added.
597 */
598 void implementInterfaceMethods(ClassSymbol c) {
599 implementInterfaceMethods(c, c);
600 }
602 /** Add abstract methods for all methods defined in one of
603 * the interfaces of a given class,
604 * provided they are not already implemented in the class.
605 *
606 * @param c The class whose interfaces are searched for methods
607 * for which Miranda methods should be added.
608 * @param site The class in which a definition may be needed.
609 */
610 void implementInterfaceMethods(ClassSymbol c, ClassSymbol site) {
611 for (List<Type> l = types.interfaces(c.type); l.nonEmpty(); l = l.tail) {
612 ClassSymbol i = (ClassSymbol)l.head.tsym;
613 for (Scope.Entry e = i.members().elems;
614 e != null;
615 e = e.sibling)
616 {
617 if (e.sym.kind == MTH && (e.sym.flags() & STATIC) == 0)
618 {
619 MethodSymbol absMeth = (MethodSymbol)e.sym;
620 MethodSymbol implMeth = absMeth.binaryImplementation(site, types);
621 if (implMeth == null)
622 addAbstractMethod(site, absMeth);
623 else if ((implMeth.flags() & IPROXY) != 0)
624 adjustAbstractMethod(site, implMeth, absMeth);
625 }
626 }
627 implementInterfaceMethods(i, site);
628 }
629 }
631 /** Add an abstract methods to a class
632 * which implicitly implements a method defined in some interface
633 * implemented by the class. These methods are called "Miranda methods".
634 * Enter the newly created method into its enclosing class scope.
635 * Note that it is not entered into the class tree, as the emitter
636 * doesn't need to see it there to emit an abstract method.
637 *
638 * @param c The class to which the Miranda method is added.
639 * @param m The interface method symbol for which a Miranda method
640 * is added.
641 */
642 private void addAbstractMethod(ClassSymbol c,
643 MethodSymbol m) {
644 MethodSymbol absMeth = new MethodSymbol(
645 m.flags() | IPROXY | SYNTHETIC, m.name,
646 m.type, // was c.type.memberType(m), but now only !generics supported
647 c);
648 c.members().enter(absMeth); // add to symbol table
649 }
651 private void adjustAbstractMethod(ClassSymbol c,
652 MethodSymbol pm,
653 MethodSymbol im) {
654 MethodType pmt = (MethodType)pm.type;
655 Type imt = types.memberType(c.type, im);
656 pmt.thrown = chk.intersect(pmt.getThrownTypes(), imt.getThrownTypes());
657 }
659 /* ************************************************************************
660 * Traversal methods
661 *************************************************************************/
663 /** Visitor argument: The current environment.
664 */
665 Env<GenContext> env;
667 /** Visitor argument: The expected type (prototype).
668 */
669 Type pt;
671 /** Visitor result: The item representing the computed value.
672 */
673 Item result;
675 /** Visitor method: generate code for a definition, catching and reporting
676 * any completion failures.
677 * @param tree The definition to be visited.
678 * @param env The environment current at the definition.
679 */
680 public void genDef(JCTree tree, Env<GenContext> env) {
681 Env<GenContext> prevEnv = this.env;
682 try {
683 this.env = env;
684 tree.accept(this);
685 } catch (CompletionFailure ex) {
686 chk.completionError(tree.pos(), ex);
687 } finally {
688 this.env = prevEnv;
689 }
690 }
692 /** Derived visitor method: check whether CharacterRangeTable
693 * should be emitted, if so, put a new entry into CRTable
694 * and call method to generate bytecode.
695 * If not, just call method to generate bytecode.
696 * @see #genStat(JCTree, Env)
697 *
698 * @param tree The tree to be visited.
699 * @param env The environment to use.
700 * @param crtFlags The CharacterRangeTable flags
701 * indicating type of the entry.
702 */
703 public void genStat(JCTree tree, Env<GenContext> env, int crtFlags) {
704 if (!genCrt) {
705 genStat(tree, env);
706 return;
707 }
708 int startpc = code.curPc();
709 genStat(tree, env);
710 if (tree.hasTag(Tag.BLOCK)) crtFlags |= CRT_BLOCK;
711 code.crt.put(tree, crtFlags, startpc, code.curPc());
712 }
714 /** Derived visitor method: generate code for a statement.
715 */
716 public void genStat(JCTree tree, Env<GenContext> env) {
717 if (code.isAlive()) {
718 code.statBegin(tree.pos);
719 genDef(tree, env);
720 } else if (env.info.isSwitch && tree.hasTag(VARDEF)) {
721 // variables whose declarations are in a switch
722 // can be used even if the decl is unreachable.
723 code.newLocal(((JCVariableDecl) tree).sym);
724 }
725 }
727 /** Derived visitor method: check whether CharacterRangeTable
728 * should be emitted, if so, put a new entry into CRTable
729 * and call method to generate bytecode.
730 * If not, just call method to generate bytecode.
731 * @see #genStats(List, Env)
732 *
733 * @param trees The list of trees to be visited.
734 * @param env The environment to use.
735 * @param crtFlags The CharacterRangeTable flags
736 * indicating type of the entry.
737 */
738 public void genStats(List<JCStatement> trees, Env<GenContext> env, int crtFlags) {
739 if (!genCrt) {
740 genStats(trees, env);
741 return;
742 }
743 if (trees.length() == 1) { // mark one statement with the flags
744 genStat(trees.head, env, crtFlags | CRT_STATEMENT);
745 } else {
746 int startpc = code.curPc();
747 genStats(trees, env);
748 code.crt.put(trees, crtFlags, startpc, code.curPc());
749 }
750 }
752 /** Derived visitor method: generate code for a list of statements.
753 */
754 public void genStats(List<? extends JCTree> trees, Env<GenContext> env) {
755 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
756 genStat(l.head, env, CRT_STATEMENT);
757 }
759 /** Derived visitor method: check whether CharacterRangeTable
760 * should be emitted, if so, put a new entry into CRTable
761 * and call method to generate bytecode.
762 * If not, just call method to generate bytecode.
763 * @see #genCond(JCTree,boolean)
764 *
765 * @param tree The tree to be visited.
766 * @param crtFlags The CharacterRangeTable flags
767 * indicating type of the entry.
768 */
769 public CondItem genCond(JCTree tree, int crtFlags) {
770 if (!genCrt) return genCond(tree, false);
771 int startpc = code.curPc();
772 CondItem item = genCond(tree, (crtFlags & CRT_FLOW_CONTROLLER) != 0);
773 code.crt.put(tree, crtFlags, startpc, code.curPc());
774 return item;
775 }
777 /** Derived visitor method: generate code for a boolean
778 * expression in a control-flow context.
779 * @param _tree The expression to be visited.
780 * @param markBranches The flag to indicate that the condition is
781 * a flow controller so produced conditions
782 * should contain a proper tree to generate
783 * CharacterRangeTable branches for them.
784 */
785 public CondItem genCond(JCTree _tree, boolean markBranches) {
786 JCTree inner_tree = TreeInfo.skipParens(_tree);
787 if (inner_tree.hasTag(CONDEXPR)) {
788 JCConditional tree = (JCConditional)inner_tree;
789 CondItem cond = genCond(tree.cond, CRT_FLOW_CONTROLLER);
790 if (cond.isTrue()) {
791 code.resolve(cond.trueJumps);
792 CondItem result = genCond(tree.truepart, CRT_FLOW_TARGET);
793 if (markBranches) result.tree = tree.truepart;
794 return result;
795 }
796 if (cond.isFalse()) {
797 code.resolve(cond.falseJumps);
798 CondItem result = genCond(tree.falsepart, CRT_FLOW_TARGET);
799 if (markBranches) result.tree = tree.falsepart;
800 return result;
801 }
802 Chain secondJumps = cond.jumpFalse();
803 code.resolve(cond.trueJumps);
804 CondItem first = genCond(tree.truepart, CRT_FLOW_TARGET);
805 if (markBranches) first.tree = tree.truepart;
806 Chain falseJumps = first.jumpFalse();
807 code.resolve(first.trueJumps);
808 Chain trueJumps = code.branch(goto_);
809 code.resolve(secondJumps);
810 CondItem second = genCond(tree.falsepart, CRT_FLOW_TARGET);
811 CondItem result = items.makeCondItem(second.opcode,
812 Code.mergeChains(trueJumps, second.trueJumps),
813 Code.mergeChains(falseJumps, second.falseJumps));
814 if (markBranches) result.tree = tree.falsepart;
815 return result;
816 } else {
817 CondItem result = genExpr(_tree, syms.booleanType).mkCond();
818 if (markBranches) result.tree = _tree;
819 return result;
820 }
821 }
823 /** Visitor class for expressions which might be constant expressions.
824 * This class is a subset of TreeScanner. Intended to visit trees pruned by
825 * Lower as long as constant expressions looking for references to any
826 * ClassSymbol. Any such reference will be added to the constant pool so
827 * automated tools can detect class dependencies better.
828 */
829 class ClassReferenceVisitor extends JCTree.Visitor {
831 @Override
832 public void visitTree(JCTree tree) {}
834 @Override
835 public void visitBinary(JCBinary tree) {
836 tree.lhs.accept(this);
837 tree.rhs.accept(this);
838 }
840 @Override
841 public void visitSelect(JCFieldAccess tree) {
842 if (tree.selected.type.hasTag(CLASS)) {
843 makeRef(tree.selected.pos(), tree.selected.type);
844 }
845 }
847 @Override
848 public void visitIdent(JCIdent tree) {
849 if (tree.sym.owner instanceof ClassSymbol) {
850 pool.put(tree.sym.owner);
851 }
852 }
854 @Override
855 public void visitConditional(JCConditional tree) {
856 tree.cond.accept(this);
857 tree.truepart.accept(this);
858 tree.falsepart.accept(this);
859 }
861 @Override
862 public void visitUnary(JCUnary tree) {
863 tree.arg.accept(this);
864 }
866 @Override
867 public void visitParens(JCParens tree) {
868 tree.expr.accept(this);
869 }
871 @Override
872 public void visitTypeCast(JCTypeCast tree) {
873 tree.expr.accept(this);
874 }
875 }
877 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor();
879 /** Visitor method: generate code for an expression, catching and reporting
880 * any completion failures.
881 * @param tree The expression to be visited.
882 * @param pt The expression's expected type (proto-type).
883 */
884 public Item genExpr(JCTree tree, Type pt) {
885 Type prevPt = this.pt;
886 try {
887 if (tree.type.constValue() != null) {
888 // Short circuit any expressions which are constants
889 tree.accept(classReferenceVisitor);
890 checkStringConstant(tree.pos(), tree.type.constValue());
891 result = items.makeImmediateItem(tree.type, tree.type.constValue());
892 } else {
893 this.pt = pt;
894 tree.accept(this);
895 }
896 return result.coerce(pt);
897 } catch (CompletionFailure ex) {
898 chk.completionError(tree.pos(), ex);
899 code.state.stacksize = 1;
900 return items.makeStackItem(pt);
901 } finally {
902 this.pt = prevPt;
903 }
904 }
906 /** Derived visitor method: generate code for a list of method arguments.
907 * @param trees The argument expressions to be visited.
908 * @param pts The expression's expected types (i.e. the formal parameter
909 * types of the invoked method).
910 */
911 public void genArgs(List<JCExpression> trees, List<Type> pts) {
912 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
913 genExpr(l.head, pts.head).load();
914 pts = pts.tail;
915 }
916 // require lists be of same length
917 Assert.check(pts.isEmpty());
918 }
920 /* ************************************************************************
921 * Visitor methods for statements and definitions
922 *************************************************************************/
924 /** Thrown when the byte code size exceeds limit.
925 */
926 public static class CodeSizeOverflow extends RuntimeException {
927 private static final long serialVersionUID = 0;
928 public CodeSizeOverflow() {}
929 }
931 public void visitMethodDef(JCMethodDecl tree) {
932 // Create a new local environment that points pack at method
933 // definition.
934 Env<GenContext> localEnv = env.dup(tree);
935 localEnv.enclMethod = tree;
937 // The expected type of every return statement in this method
938 // is the method's return type.
939 this.pt = tree.sym.erasure(types).getReturnType();
941 checkDimension(tree.pos(), tree.sym.erasure(types));
942 genMethod(tree, localEnv, false);
943 }
944 //where
945 /** Generate code for a method.
946 * @param tree The tree representing the method definition.
947 * @param env The environment current for the method body.
948 * @param fatcode A flag that indicates whether all jumps are
949 * within 32K. We first invoke this method under
950 * the assumption that fatcode == false, i.e. all
951 * jumps are within 32K. If this fails, fatcode
952 * is set to true and we try again.
953 */
954 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
955 MethodSymbol meth = tree.sym;
956 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
957 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) +
958 (((tree.mods.flags & STATIC) == 0 || meth.isConstructor()) ? 1 : 0) >
959 ClassFile.MAX_PARAMETERS) {
960 log.error(tree.pos(), "limit.parameters");
961 nerrs++;
962 }
964 else if (tree.body != null) {
965 // Create a new code structure and initialize it.
966 int startpcCrt = initCode(tree, env, fatcode);
968 try {
969 genStat(tree.body, env);
970 } catch (CodeSizeOverflow e) {
971 // Failed due to code limit, try again with jsr/ret
972 startpcCrt = initCode(tree, env, fatcode);
973 genStat(tree.body, env);
974 }
976 if (code.state.stacksize != 0) {
977 log.error(tree.body.pos(), "stack.sim.error", tree);
978 throw new AssertionError();
979 }
981 // If last statement could complete normally, insert a
982 // return at the end.
983 if (code.isAlive()) {
984 code.statBegin(TreeInfo.endPos(tree.body));
985 if (env.enclMethod == null ||
986 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
987 code.emitop0(return_);
988 } else {
989 // sometime dead code seems alive (4415991);
990 // generate a small loop instead
991 int startpc = code.entryPoint();
992 CondItem c = items.makeCondItem(goto_);
993 code.resolve(c.jumpTrue(), startpc);
994 }
995 }
996 if (genCrt)
997 code.crt.put(tree.body,
998 CRT_BLOCK,
999 startpcCrt,
1000 code.curPc());
1002 code.endScopes(0);
1004 // If we exceeded limits, panic
1005 if (code.checkLimits(tree.pos(), log)) {
1006 nerrs++;
1007 return;
1008 }
1010 // If we generated short code but got a long jump, do it again
1011 // with fatCode = true.
1012 if (!fatcode && code.fatcode) genMethod(tree, env, true);
1014 // Clean up
1015 if(stackMap == StackMapFormat.JSR202) {
1016 code.lastFrame = null;
1017 code.frameBeforeLast = null;
1018 }
1020 // Compress exception table
1021 code.compressCatchTable();
1023 // Fill in type annotation positions for exception parameters
1024 code.fillExceptionParameterPositions();
1025 }
1026 }
1028 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1029 MethodSymbol meth = tree.sym;
1031 // Create a new code structure.
1032 meth.code = code = new Code(meth,
1033 fatcode,
1034 lineDebugInfo ? toplevel.lineMap : null,
1035 varDebugInfo,
1036 stackMap,
1037 debugCode,
1038 genCrt ? new CRTable(tree, env.toplevel.endPositions)
1039 : null,
1040 syms,
1041 types,
1042 pool);
1043 items = new Items(pool, code, syms, types);
1044 if (code.debugCode)
1045 System.err.println(meth + " for body " + tree);
1047 // If method is not static, create a new local variable address
1048 // for `this'.
1049 if ((tree.mods.flags & STATIC) == 0) {
1050 Type selfType = meth.owner.type;
1051 if (meth.isConstructor() && selfType != syms.objectType)
1052 selfType = UninitializedType.uninitializedThis(selfType);
1053 code.setDefined(
1054 code.newLocal(
1055 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1056 }
1058 // Mark all parameters as defined from the beginning of
1059 // the method.
1060 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1061 checkDimension(l.head.pos(), l.head.sym.type);
1062 code.setDefined(code.newLocal(l.head.sym));
1063 }
1065 // Get ready to generate code for method body.
1066 int startpcCrt = genCrt ? code.curPc() : 0;
1067 code.entryPoint();
1069 // Suppress initial stackmap
1070 code.pendingStackMap = false;
1072 return startpcCrt;
1073 }
1075 public void visitVarDef(JCVariableDecl tree) {
1076 VarSymbol v = tree.sym;
1077 code.newLocal(v);
1078 if (tree.init != null) {
1079 checkStringConstant(tree.init.pos(), v.getConstValue());
1080 if (v.getConstValue() == null || varDebugInfo) {
1081 genExpr(tree.init, v.erasure(types)).load();
1082 items.makeLocalItem(v).store();
1083 }
1084 }
1085 checkDimension(tree.pos(), v.type);
1086 }
1088 public void visitSkip(JCSkip tree) {
1089 }
1091 public void visitBlock(JCBlock tree) {
1092 int limit = code.nextreg;
1093 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1094 genStats(tree.stats, localEnv);
1095 // End the scope of all block-local variables in variable info.
1096 if (!env.tree.hasTag(METHODDEF)) {
1097 code.statBegin(tree.endpos);
1098 code.endScopes(limit);
1099 code.pendingStatPos = Position.NOPOS;
1100 }
1101 }
1103 public void visitDoLoop(JCDoWhileLoop tree) {
1104 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), false);
1105 }
1107 public void visitWhileLoop(JCWhileLoop tree) {
1108 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), true);
1109 }
1111 public void visitForLoop(JCForLoop tree) {
1112 int limit = code.nextreg;
1113 genStats(tree.init, env);
1114 genLoop(tree, tree.body, tree.cond, tree.step, true);
1115 code.endScopes(limit);
1116 }
1117 //where
1118 /** Generate code for a loop.
1119 * @param loop The tree representing the loop.
1120 * @param body The loop's body.
1121 * @param cond The loop's controling condition.
1122 * @param step "Step" statements to be inserted at end of
1123 * each iteration.
1124 * @param testFirst True if the loop test belongs before the body.
1125 */
1126 private void genLoop(JCStatement loop,
1127 JCStatement body,
1128 JCExpression cond,
1129 List<JCExpressionStatement> step,
1130 boolean testFirst) {
1131 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1132 int startpc = code.entryPoint();
1133 if (testFirst) {
1134 CondItem c;
1135 if (cond != null) {
1136 code.statBegin(cond.pos);
1137 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1138 } else {
1139 c = items.makeCondItem(goto_);
1140 }
1141 Chain loopDone = c.jumpFalse();
1142 code.resolve(c.trueJumps);
1143 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1144 code.resolve(loopEnv.info.cont);
1145 genStats(step, loopEnv);
1146 code.resolve(code.branch(goto_), startpc);
1147 code.resolve(loopDone);
1148 } else {
1149 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1150 code.resolve(loopEnv.info.cont);
1151 genStats(step, loopEnv);
1152 CondItem c;
1153 if (cond != null) {
1154 code.statBegin(cond.pos);
1155 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1156 } else {
1157 c = items.makeCondItem(goto_);
1158 }
1159 code.resolve(c.jumpTrue(), startpc);
1160 code.resolve(c.falseJumps);
1161 }
1162 code.resolve(loopEnv.info.exit);
1163 }
1165 public void visitForeachLoop(JCEnhancedForLoop tree) {
1166 throw new AssertionError(); // should have been removed by Lower.
1167 }
1169 public void visitLabelled(JCLabeledStatement tree) {
1170 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1171 genStat(tree.body, localEnv, CRT_STATEMENT);
1172 code.resolve(localEnv.info.exit);
1173 }
1175 public void visitSwitch(JCSwitch tree) {
1176 int limit = code.nextreg;
1177 Assert.check(!tree.selector.type.hasTag(CLASS));
1178 int startpcCrt = genCrt ? code.curPc() : 0;
1179 Item sel = genExpr(tree.selector, syms.intType);
1180 List<JCCase> cases = tree.cases;
1181 if (cases.isEmpty()) {
1182 // We are seeing: switch <sel> {}
1183 sel.load().drop();
1184 if (genCrt)
1185 code.crt.put(TreeInfo.skipParens(tree.selector),
1186 CRT_FLOW_CONTROLLER, startpcCrt, code.curPc());
1187 } else {
1188 // We are seeing a nonempty switch.
1189 sel.load();
1190 if (genCrt)
1191 code.crt.put(TreeInfo.skipParens(tree.selector),
1192 CRT_FLOW_CONTROLLER, startpcCrt, code.curPc());
1193 Env<GenContext> switchEnv = env.dup(tree, new GenContext());
1194 switchEnv.info.isSwitch = true;
1196 // Compute number of labels and minimum and maximum label values.
1197 // For each case, store its label in an array.
1198 int lo = Integer.MAX_VALUE; // minimum label.
1199 int hi = Integer.MIN_VALUE; // maximum label.
1200 int nlabels = 0; // number of labels.
1202 int[] labels = new int[cases.length()]; // the label array.
1203 int defaultIndex = -1; // the index of the default clause.
1205 List<JCCase> l = cases;
1206 for (int i = 0; i < labels.length; i++) {
1207 if (l.head.pat != null) {
1208 int val = ((Number)l.head.pat.type.constValue()).intValue();
1209 labels[i] = val;
1210 if (val < lo) lo = val;
1211 if (hi < val) hi = val;
1212 nlabels++;
1213 } else {
1214 Assert.check(defaultIndex == -1);
1215 defaultIndex = i;
1216 }
1217 l = l.tail;
1218 }
1220 // Determine whether to issue a tableswitch or a lookupswitch
1221 // instruction.
1222 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1223 long table_time_cost = 3; // comparisons
1224 long lookup_space_cost = 3 + 2 * (long) nlabels;
1225 long lookup_time_cost = nlabels;
1226 int opcode =
1227 nlabels > 0 &&
1228 table_space_cost + 3 * table_time_cost <=
1229 lookup_space_cost + 3 * lookup_time_cost
1230 ?
1231 tableswitch : lookupswitch;
1233 int startpc = code.curPc(); // the position of the selector operation
1234 code.emitop0(opcode);
1235 code.align(4);
1236 int tableBase = code.curPc(); // the start of the jump table
1237 int[] offsets = null; // a table of offsets for a lookupswitch
1238 code.emit4(-1); // leave space for default offset
1239 if (opcode == tableswitch) {
1240 code.emit4(lo); // minimum label
1241 code.emit4(hi); // maximum label
1242 for (long i = lo; i <= hi; i++) { // leave space for jump table
1243 code.emit4(-1);
1244 }
1245 } else {
1246 code.emit4(nlabels); // number of labels
1247 for (int i = 0; i < nlabels; i++) {
1248 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1249 }
1250 offsets = new int[labels.length];
1251 }
1252 Code.State stateSwitch = code.state.dup();
1253 code.markDead();
1255 // For each case do:
1256 l = cases;
1257 for (int i = 0; i < labels.length; i++) {
1258 JCCase c = l.head;
1259 l = l.tail;
1261 int pc = code.entryPoint(stateSwitch);
1262 // Insert offset directly into code or else into the
1263 // offsets table.
1264 if (i != defaultIndex) {
1265 if (opcode == tableswitch) {
1266 code.put4(
1267 tableBase + 4 * (labels[i] - lo + 3),
1268 pc - startpc);
1269 } else {
1270 offsets[i] = pc - startpc;
1271 }
1272 } else {
1273 code.put4(tableBase, pc - startpc);
1274 }
1276 // Generate code for the statements in this case.
1277 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1278 }
1280 // Resolve all breaks.
1281 code.resolve(switchEnv.info.exit);
1283 // If we have not set the default offset, we do so now.
1284 if (code.get4(tableBase) == -1) {
1285 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1286 }
1288 if (opcode == tableswitch) {
1289 // Let any unfilled slots point to the default case.
1290 int defaultOffset = code.get4(tableBase);
1291 for (long i = lo; i <= hi; i++) {
1292 int t = (int)(tableBase + 4 * (i - lo + 3));
1293 if (code.get4(t) == -1)
1294 code.put4(t, defaultOffset);
1295 }
1296 } else {
1297 // Sort non-default offsets and copy into lookup table.
1298 if (defaultIndex >= 0)
1299 for (int i = defaultIndex; i < labels.length - 1; i++) {
1300 labels[i] = labels[i+1];
1301 offsets[i] = offsets[i+1];
1302 }
1303 if (nlabels > 0)
1304 qsort2(labels, offsets, 0, nlabels - 1);
1305 for (int i = 0; i < nlabels; i++) {
1306 int caseidx = tableBase + 8 * (i + 1);
1307 code.put4(caseidx, labels[i]);
1308 code.put4(caseidx + 4, offsets[i]);
1309 }
1310 }
1311 }
1312 code.endScopes(limit);
1313 }
1314 //where
1315 /** Sort (int) arrays of keys and values
1316 */
1317 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1318 int i = lo;
1319 int j = hi;
1320 int pivot = keys[(i+j)/2];
1321 do {
1322 while (keys[i] < pivot) i++;
1323 while (pivot < keys[j]) j--;
1324 if (i <= j) {
1325 int temp1 = keys[i];
1326 keys[i] = keys[j];
1327 keys[j] = temp1;
1328 int temp2 = values[i];
1329 values[i] = values[j];
1330 values[j] = temp2;
1331 i++;
1332 j--;
1333 }
1334 } while (i <= j);
1335 if (lo < j) qsort2(keys, values, lo, j);
1336 if (i < hi) qsort2(keys, values, i, hi);
1337 }
1339 public void visitSynchronized(JCSynchronized tree) {
1340 int limit = code.nextreg;
1341 // Generate code to evaluate lock and save in temporary variable.
1342 final LocalItem lockVar = makeTemp(syms.objectType);
1343 genExpr(tree.lock, tree.lock.type).load().duplicate();
1344 lockVar.store();
1346 // Generate code to enter monitor.
1347 code.emitop0(monitorenter);
1348 code.state.lock(lockVar.reg);
1350 // Generate code for a try statement with given body, no catch clauses
1351 // in a new environment with the "exit-monitor" operation as finalizer.
1352 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1353 syncEnv.info.finalize = new GenFinalizer() {
1354 void gen() {
1355 genLast();
1356 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1357 syncEnv.info.gaps.append(code.curPc());
1358 }
1359 void genLast() {
1360 if (code.isAlive()) {
1361 lockVar.load();
1362 code.emitop0(monitorexit);
1363 code.state.unlock(lockVar.reg);
1364 }
1365 }
1366 };
1367 syncEnv.info.gaps = new ListBuffer<Integer>();
1368 genTry(tree.body, List.<JCCatch>nil(), syncEnv);
1369 code.endScopes(limit);
1370 }
1372 public void visitTry(final JCTry tree) {
1373 // Generate code for a try statement with given body and catch clauses,
1374 // in a new environment which calls the finally block if there is one.
1375 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1376 final Env<GenContext> oldEnv = env;
1377 if (!useJsrLocally) {
1378 useJsrLocally =
1379 (stackMap == StackMapFormat.NONE) &&
1380 (jsrlimit <= 0 ||
1381 jsrlimit < 100 &&
1382 estimateCodeComplexity(tree.finalizer)>jsrlimit);
1383 }
1384 tryEnv.info.finalize = new GenFinalizer() {
1385 void gen() {
1386 if (useJsrLocally) {
1387 if (tree.finalizer != null) {
1388 Code.State jsrState = code.state.dup();
1389 jsrState.push(Code.jsrReturnValue);
1390 tryEnv.info.cont =
1391 new Chain(code.emitJump(jsr),
1392 tryEnv.info.cont,
1393 jsrState);
1394 }
1395 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1396 tryEnv.info.gaps.append(code.curPc());
1397 } else {
1398 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1399 tryEnv.info.gaps.append(code.curPc());
1400 genLast();
1401 }
1402 }
1403 void genLast() {
1404 if (tree.finalizer != null)
1405 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1406 }
1407 boolean hasFinalizer() {
1408 return tree.finalizer != null;
1409 }
1410 };
1411 tryEnv.info.gaps = new ListBuffer<Integer>();
1412 genTry(tree.body, tree.catchers, tryEnv);
1413 }
1414 //where
1415 /** Generate code for a try or synchronized statement
1416 * @param body The body of the try or synchronized statement.
1417 * @param catchers The lis of catch clauses.
1418 * @param env the environment current for the body.
1419 */
1420 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1421 int limit = code.nextreg;
1422 int startpc = code.curPc();
1423 Code.State stateTry = code.state.dup();
1424 genStat(body, env, CRT_BLOCK);
1425 int endpc = code.curPc();
1426 boolean hasFinalizer =
1427 env.info.finalize != null &&
1428 env.info.finalize.hasFinalizer();
1429 List<Integer> gaps = env.info.gaps.toList();
1430 code.statBegin(TreeInfo.endPos(body));
1431 genFinalizer(env);
1432 code.statBegin(TreeInfo.endPos(env.tree));
1433 Chain exitChain = code.branch(goto_);
1434 endFinalizerGap(env);
1435 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1436 // start off with exception on stack
1437 code.entryPoint(stateTry, l.head.param.sym.type);
1438 genCatch(l.head, env, startpc, endpc, gaps);
1439 genFinalizer(env);
1440 if (hasFinalizer || l.tail.nonEmpty()) {
1441 code.statBegin(TreeInfo.endPos(env.tree));
1442 exitChain = Code.mergeChains(exitChain,
1443 code.branch(goto_));
1444 }
1445 endFinalizerGap(env);
1446 }
1447 if (hasFinalizer) {
1448 // Create a new register segement to avoid allocating
1449 // the same variables in finalizers and other statements.
1450 code.newRegSegment();
1452 // Add a catch-all clause.
1454 // start off with exception on stack
1455 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1457 // Register all exception ranges for catch all clause.
1458 // The range of the catch all clause is from the beginning
1459 // of the try or synchronized block until the present
1460 // code pointer excluding all gaps in the current
1461 // environment's GenContext.
1462 int startseg = startpc;
1463 while (env.info.gaps.nonEmpty()) {
1464 int endseg = env.info.gaps.next().intValue();
1465 registerCatch(body.pos(), startseg, endseg,
1466 catchallpc, 0);
1467 startseg = env.info.gaps.next().intValue();
1468 }
1469 code.statBegin(TreeInfo.finalizerPos(env.tree));
1470 code.markStatBegin();
1472 Item excVar = makeTemp(syms.throwableType);
1473 excVar.store();
1474 genFinalizer(env);
1475 excVar.load();
1476 registerCatch(body.pos(), startseg,
1477 env.info.gaps.next().intValue(),
1478 catchallpc, 0);
1479 code.emitop0(athrow);
1480 code.markDead();
1482 // If there are jsr's to this finalizer, ...
1483 if (env.info.cont != null) {
1484 // Resolve all jsr's.
1485 code.resolve(env.info.cont);
1487 // Mark statement line number
1488 code.statBegin(TreeInfo.finalizerPos(env.tree));
1489 code.markStatBegin();
1491 // Save return address.
1492 LocalItem retVar = makeTemp(syms.throwableType);
1493 retVar.store();
1495 // Generate finalizer code.
1496 env.info.finalize.genLast();
1498 // Return.
1499 code.emitop1w(ret, retVar.reg);
1500 code.markDead();
1501 }
1502 }
1503 // Resolve all breaks.
1504 code.resolve(exitChain);
1506 code.endScopes(limit);
1507 }
1509 /** Generate code for a catch clause.
1510 * @param tree The catch clause.
1511 * @param env The environment current in the enclosing try.
1512 * @param startpc Start pc of try-block.
1513 * @param endpc End pc of try-block.
1514 */
1515 void genCatch(JCCatch tree,
1516 Env<GenContext> env,
1517 int startpc, int endpc,
1518 List<Integer> gaps) {
1519 if (startpc != endpc) {
1520 List<JCExpression> subClauses = TreeInfo.isMultiCatch(tree) ?
1521 ((JCTypeUnion)tree.param.vartype).alternatives :
1522 List.of(tree.param.vartype);
1523 while (gaps.nonEmpty()) {
1524 for (JCExpression subCatch : subClauses) {
1525 int catchType = makeRef(tree.pos(), subCatch.type);
1526 int end = gaps.head.intValue();
1527 registerCatch(tree.pos(),
1528 startpc, end, code.curPc(),
1529 catchType);
1530 }
1531 gaps = gaps.tail;
1532 startpc = gaps.head.intValue();
1533 gaps = gaps.tail;
1534 }
1535 if (startpc < endpc) {
1536 for (JCExpression subCatch : subClauses) {
1537 int catchType = makeRef(tree.pos(), subCatch.type);
1538 registerCatch(tree.pos(),
1539 startpc, endpc, code.curPc(),
1540 catchType);
1541 }
1542 }
1543 VarSymbol exparam = tree.param.sym;
1544 code.statBegin(tree.pos);
1545 code.markStatBegin();
1546 int limit = code.nextreg;
1547 int exlocal = code.newLocal(exparam);
1548 items.makeLocalItem(exparam).store();
1549 code.statBegin(TreeInfo.firstStatPos(tree.body));
1550 genStat(tree.body, env, CRT_BLOCK);
1551 code.endScopes(limit);
1552 code.statBegin(TreeInfo.endPos(tree.body));
1553 }
1554 }
1556 /** Register a catch clause in the "Exceptions" code-attribute.
1557 */
1558 void registerCatch(DiagnosticPosition pos,
1559 int startpc, int endpc,
1560 int handler_pc, int catch_type) {
1561 char startpc1 = (char)startpc;
1562 char endpc1 = (char)endpc;
1563 char handler_pc1 = (char)handler_pc;
1564 if (startpc1 == startpc &&
1565 endpc1 == endpc &&
1566 handler_pc1 == handler_pc) {
1567 code.addCatch(startpc1, endpc1, handler_pc1,
1568 (char)catch_type);
1569 } else {
1570 if (!useJsrLocally && !target.generateStackMapTable()) {
1571 useJsrLocally = true;
1572 throw new CodeSizeOverflow();
1573 } else {
1574 log.error(pos, "limit.code.too.large.for.try.stmt");
1575 nerrs++;
1576 }
1577 }
1578 }
1580 /** Very roughly estimate the number of instructions needed for
1581 * the given tree.
1582 */
1583 int estimateCodeComplexity(JCTree tree) {
1584 if (tree == null) return 0;
1585 class ComplexityScanner extends TreeScanner {
1586 int complexity = 0;
1587 public void scan(JCTree tree) {
1588 if (complexity > jsrlimit) return;
1589 super.scan(tree);
1590 }
1591 public void visitClassDef(JCClassDecl tree) {}
1592 public void visitDoLoop(JCDoWhileLoop tree)
1593 { super.visitDoLoop(tree); complexity++; }
1594 public void visitWhileLoop(JCWhileLoop tree)
1595 { super.visitWhileLoop(tree); complexity++; }
1596 public void visitForLoop(JCForLoop tree)
1597 { super.visitForLoop(tree); complexity++; }
1598 public void visitSwitch(JCSwitch tree)
1599 { super.visitSwitch(tree); complexity+=5; }
1600 public void visitCase(JCCase tree)
1601 { super.visitCase(tree); complexity++; }
1602 public void visitSynchronized(JCSynchronized tree)
1603 { super.visitSynchronized(tree); complexity+=6; }
1604 public void visitTry(JCTry tree)
1605 { super.visitTry(tree);
1606 if (tree.finalizer != null) complexity+=6; }
1607 public void visitCatch(JCCatch tree)
1608 { super.visitCatch(tree); complexity+=2; }
1609 public void visitConditional(JCConditional tree)
1610 { super.visitConditional(tree); complexity+=2; }
1611 public void visitIf(JCIf tree)
1612 { super.visitIf(tree); complexity+=2; }
1613 // note: for break, continue, and return we don't take unwind() into account.
1614 public void visitBreak(JCBreak tree)
1615 { super.visitBreak(tree); complexity+=1; }
1616 public void visitContinue(JCContinue tree)
1617 { super.visitContinue(tree); complexity+=1; }
1618 public void visitReturn(JCReturn tree)
1619 { super.visitReturn(tree); complexity+=1; }
1620 public void visitThrow(JCThrow tree)
1621 { super.visitThrow(tree); complexity+=1; }
1622 public void visitAssert(JCAssert tree)
1623 { super.visitAssert(tree); complexity+=5; }
1624 public void visitApply(JCMethodInvocation tree)
1625 { super.visitApply(tree); complexity+=2; }
1626 public void visitNewClass(JCNewClass tree)
1627 { scan(tree.encl); scan(tree.args); complexity+=2; }
1628 public void visitNewArray(JCNewArray tree)
1629 { super.visitNewArray(tree); complexity+=5; }
1630 public void visitAssign(JCAssign tree)
1631 { super.visitAssign(tree); complexity+=1; }
1632 public void visitAssignop(JCAssignOp tree)
1633 { super.visitAssignop(tree); complexity+=2; }
1634 public void visitUnary(JCUnary tree)
1635 { complexity+=1;
1636 if (tree.type.constValue() == null) super.visitUnary(tree); }
1637 public void visitBinary(JCBinary tree)
1638 { complexity+=1;
1639 if (tree.type.constValue() == null) super.visitBinary(tree); }
1640 public void visitTypeTest(JCInstanceOf tree)
1641 { super.visitTypeTest(tree); complexity+=1; }
1642 public void visitIndexed(JCArrayAccess tree)
1643 { super.visitIndexed(tree); complexity+=1; }
1644 public void visitSelect(JCFieldAccess tree)
1645 { super.visitSelect(tree);
1646 if (tree.sym.kind == VAR) complexity+=1; }
1647 public void visitIdent(JCIdent tree) {
1648 if (tree.sym.kind == VAR) {
1649 complexity+=1;
1650 if (tree.type.constValue() == null &&
1651 tree.sym.owner.kind == TYP)
1652 complexity+=1;
1653 }
1654 }
1655 public void visitLiteral(JCLiteral tree)
1656 { complexity+=1; }
1657 public void visitTree(JCTree tree) {}
1658 public void visitWildcard(JCWildcard tree) {
1659 throw new AssertionError(this.getClass().getName());
1660 }
1661 }
1662 ComplexityScanner scanner = new ComplexityScanner();
1663 tree.accept(scanner);
1664 return scanner.complexity;
1665 }
1667 public void visitIf(JCIf tree) {
1668 int limit = code.nextreg;
1669 Chain thenExit = null;
1670 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1671 CRT_FLOW_CONTROLLER);
1672 Chain elseChain = c.jumpFalse();
1673 if (!c.isFalse()) {
1674 code.resolve(c.trueJumps);
1675 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1676 thenExit = code.branch(goto_);
1677 }
1678 if (elseChain != null) {
1679 code.resolve(elseChain);
1680 if (tree.elsepart != null)
1681 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1682 }
1683 code.resolve(thenExit);
1684 code.endScopes(limit);
1685 }
1687 public void visitExec(JCExpressionStatement tree) {
1688 // Optimize x++ to ++x and x-- to --x.
1689 JCExpression e = tree.expr;
1690 switch (e.getTag()) {
1691 case POSTINC:
1692 ((JCUnary) e).setTag(PREINC);
1693 break;
1694 case POSTDEC:
1695 ((JCUnary) e).setTag(PREDEC);
1696 break;
1697 }
1698 genExpr(tree.expr, tree.expr.type).drop();
1699 }
1701 public void visitBreak(JCBreak tree) {
1702 Env<GenContext> targetEnv = unwind(tree.target, env);
1703 Assert.check(code.state.stacksize == 0);
1704 targetEnv.info.addExit(code.branch(goto_));
1705 endFinalizerGaps(env, targetEnv);
1706 }
1708 public void visitContinue(JCContinue tree) {
1709 Env<GenContext> targetEnv = unwind(tree.target, env);
1710 Assert.check(code.state.stacksize == 0);
1711 targetEnv.info.addCont(code.branch(goto_));
1712 endFinalizerGaps(env, targetEnv);
1713 }
1715 public void visitReturn(JCReturn tree) {
1716 int limit = code.nextreg;
1717 final Env<GenContext> targetEnv;
1718 if (tree.expr != null) {
1719 Item r = genExpr(tree.expr, pt).load();
1720 if (hasFinally(env.enclMethod, env)) {
1721 r = makeTemp(pt);
1722 r.store();
1723 }
1724 targetEnv = unwind(env.enclMethod, env);
1725 r.load();
1726 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
1727 } else {
1728 targetEnv = unwind(env.enclMethod, env);
1729 code.emitop0(return_);
1730 }
1731 endFinalizerGaps(env, targetEnv);
1732 code.endScopes(limit);
1733 }
1735 public void visitThrow(JCThrow tree) {
1736 genExpr(tree.expr, tree.expr.type).load();
1737 code.emitop0(athrow);
1738 }
1740 /* ************************************************************************
1741 * Visitor methods for expressions
1742 *************************************************************************/
1744 public void visitApply(JCMethodInvocation tree) {
1745 setTypeAnnotationPositions(tree.pos);
1746 // Generate code for method.
1747 Item m = genExpr(tree.meth, methodType);
1748 // Generate code for all arguments, where the expected types are
1749 // the parameters of the method's external type (that is, any implicit
1750 // outer instance of a super(...) call appears as first parameter).
1751 genArgs(tree.args,
1752 TreeInfo.symbol(tree.meth).externalType(types).getParameterTypes());
1753 code.statBegin(tree.pos);
1754 code.markStatBegin();
1755 result = m.invoke();
1756 }
1758 public void visitConditional(JCConditional tree) {
1759 Chain thenExit = null;
1760 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
1761 Chain elseChain = c.jumpFalse();
1762 if (!c.isFalse()) {
1763 code.resolve(c.trueJumps);
1764 int startpc = genCrt ? code.curPc() : 0;
1765 genExpr(tree.truepart, pt).load();
1766 code.state.forceStackTop(tree.type);
1767 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
1768 startpc, code.curPc());
1769 thenExit = code.branch(goto_);
1770 }
1771 if (elseChain != null) {
1772 code.resolve(elseChain);
1773 int startpc = genCrt ? code.curPc() : 0;
1774 genExpr(tree.falsepart, pt).load();
1775 code.state.forceStackTop(tree.type);
1776 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
1777 startpc, code.curPc());
1778 }
1779 code.resolve(thenExit);
1780 result = items.makeStackItem(pt);
1781 }
1783 private void setTypeAnnotationPositions(int treePos) {
1784 MethodSymbol meth = code.meth;
1786 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
1787 if (ta.position.pos == treePos) {
1788 ta.position.offset = code.cp;
1789 ta.position.lvarOffset = new int[] { code.cp };
1790 ta.position.isValidOffset = true;
1791 }
1792 }
1794 if (code.meth.getKind() != javax.lang.model.element.ElementKind.CONSTRUCTOR
1795 && code.meth.getKind() != javax.lang.model.element.ElementKind.STATIC_INIT)
1796 return;
1798 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
1799 if (ta.position.pos == treePos) {
1800 ta.position.offset = code.cp;
1801 ta.position.lvarOffset = new int[] { code.cp };
1802 ta.position.isValidOffset = true;
1803 }
1804 }
1806 ClassSymbol clazz = meth.enclClass();
1807 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
1808 if (!s.getKind().isField())
1809 continue;
1810 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
1811 if (ta.position.pos == treePos) {
1812 ta.position.offset = code.cp;
1813 ta.position.lvarOffset = new int[] { code.cp };
1814 ta.position.isValidOffset = true;
1815 }
1816 }
1817 }
1818 }
1820 public void visitNewClass(JCNewClass tree) {
1821 // Enclosing instances or anonymous classes should have been eliminated
1822 // by now.
1823 Assert.check(tree.encl == null && tree.def == null);
1824 setTypeAnnotationPositions(tree.pos);
1826 code.emitop2(new_, makeRef(tree.pos(), tree.type));
1827 code.emitop0(dup);
1829 // Generate code for all arguments, where the expected types are
1830 // the parameters of the constructor's external type (that is,
1831 // any implicit outer instance appears as first parameter).
1832 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
1834 items.makeMemberItem(tree.constructor, true).invoke();
1835 result = items.makeStackItem(tree.type);
1836 }
1838 public void visitNewArray(JCNewArray tree) {
1839 setTypeAnnotationPositions(tree.pos);
1841 if (tree.elems != null) {
1842 Type elemtype = types.elemtype(tree.type);
1843 loadIntConst(tree.elems.length());
1844 Item arr = makeNewArray(tree.pos(), tree.type, 1);
1845 int i = 0;
1846 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
1847 arr.duplicate();
1848 loadIntConst(i);
1849 i++;
1850 genExpr(l.head, elemtype).load();
1851 items.makeIndexedItem(elemtype).store();
1852 }
1853 result = arr;
1854 } else {
1855 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1856 genExpr(l.head, syms.intType).load();
1857 }
1858 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
1859 }
1860 }
1861 //where
1862 /** Generate code to create an array with given element type and number
1863 * of dimensions.
1864 */
1865 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
1866 Type elemtype = types.elemtype(type);
1867 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
1868 log.error(pos, "limit.dimensions");
1869 nerrs++;
1870 }
1871 int elemcode = Code.arraycode(elemtype);
1872 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
1873 code.emitAnewarray(makeRef(pos, elemtype), type);
1874 } else if (elemcode == 1) {
1875 code.emitMultianewarray(ndims, makeRef(pos, type), type);
1876 } else {
1877 code.emitNewarray(elemcode, type);
1878 }
1879 return items.makeStackItem(type);
1880 }
1882 public void visitParens(JCParens tree) {
1883 result = genExpr(tree.expr, tree.expr.type);
1884 }
1886 public void visitAssign(JCAssign tree) {
1887 Item l = genExpr(tree.lhs, tree.lhs.type);
1888 genExpr(tree.rhs, tree.lhs.type).load();
1889 result = items.makeAssignItem(l);
1890 }
1892 public void visitAssignop(JCAssignOp tree) {
1893 OperatorSymbol operator = (OperatorSymbol) tree.operator;
1894 Item l;
1895 if (operator.opcode == string_add) {
1896 // Generate code to make a string buffer
1897 makeStringBuffer(tree.pos());
1899 // Generate code for first string, possibly save one
1900 // copy under buffer
1901 l = genExpr(tree.lhs, tree.lhs.type);
1902 if (l.width() > 0) {
1903 code.emitop0(dup_x1 + 3 * (l.width() - 1));
1904 }
1906 // Load first string and append to buffer.
1907 l.load();
1908 appendString(tree.lhs);
1910 // Append all other strings to buffer.
1911 appendStrings(tree.rhs);
1913 // Convert buffer to string.
1914 bufferToString(tree.pos());
1915 } else {
1916 // Generate code for first expression
1917 l = genExpr(tree.lhs, tree.lhs.type);
1919 // If we have an increment of -32768 to +32767 of a local
1920 // int variable we can use an incr instruction instead of
1921 // proceeding further.
1922 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
1923 l instanceof LocalItem &&
1924 tree.lhs.type.getTag().isSubRangeOf(INT) &&
1925 tree.rhs.type.getTag().isSubRangeOf(INT) &&
1926 tree.rhs.type.constValue() != null) {
1927 int ival = ((Number) tree.rhs.type.constValue()).intValue();
1928 if (tree.hasTag(MINUS_ASG)) ival = -ival;
1929 ((LocalItem)l).incr(ival);
1930 result = l;
1931 return;
1932 }
1933 // Otherwise, duplicate expression, load one copy
1934 // and complete binary operation.
1935 l.duplicate();
1936 l.coerce(operator.type.getParameterTypes().head).load();
1937 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
1938 }
1939 result = items.makeAssignItem(l);
1940 }
1942 public void visitUnary(JCUnary tree) {
1943 OperatorSymbol operator = (OperatorSymbol)tree.operator;
1944 if (tree.hasTag(NOT)) {
1945 CondItem od = genCond(tree.arg, false);
1946 result = od.negate();
1947 } else {
1948 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
1949 switch (tree.getTag()) {
1950 case POS:
1951 result = od.load();
1952 break;
1953 case NEG:
1954 result = od.load();
1955 code.emitop0(operator.opcode);
1956 break;
1957 case COMPL:
1958 result = od.load();
1959 emitMinusOne(od.typecode);
1960 code.emitop0(operator.opcode);
1961 break;
1962 case PREINC: case PREDEC:
1963 od.duplicate();
1964 if (od instanceof LocalItem &&
1965 (operator.opcode == iadd || operator.opcode == isub)) {
1966 ((LocalItem)od).incr(tree.hasTag(PREINC) ? 1 : -1);
1967 result = od;
1968 } else {
1969 od.load();
1970 code.emitop0(one(od.typecode));
1971 code.emitop0(operator.opcode);
1972 // Perform narrowing primitive conversion if byte,
1973 // char, or short. Fix for 4304655.
1974 if (od.typecode != INTcode &&
1975 Code.truncate(od.typecode) == INTcode)
1976 code.emitop0(int2byte + od.typecode - BYTEcode);
1977 result = items.makeAssignItem(od);
1978 }
1979 break;
1980 case POSTINC: case POSTDEC:
1981 od.duplicate();
1982 if (od instanceof LocalItem &&
1983 (operator.opcode == iadd || operator.opcode == isub)) {
1984 Item res = od.load();
1985 ((LocalItem)od).incr(tree.hasTag(POSTINC) ? 1 : -1);
1986 result = res;
1987 } else {
1988 Item res = od.load();
1989 od.stash(od.typecode);
1990 code.emitop0(one(od.typecode));
1991 code.emitop0(operator.opcode);
1992 // Perform narrowing primitive conversion if byte,
1993 // char, or short. Fix for 4304655.
1994 if (od.typecode != INTcode &&
1995 Code.truncate(od.typecode) == INTcode)
1996 code.emitop0(int2byte + od.typecode - BYTEcode);
1997 od.store();
1998 result = res;
1999 }
2000 break;
2001 case NULLCHK:
2002 result = od.load();
2003 code.emitop0(dup);
2004 genNullCheck(tree.pos());
2005 break;
2006 default:
2007 Assert.error();
2008 }
2009 }
2010 }
2012 /** Generate a null check from the object value at stack top. */
2013 private void genNullCheck(DiagnosticPosition pos) {
2014 callMethod(pos, syms.objectType, names.getClass,
2015 List.<Type>nil(), false);
2016 code.emitop0(pop);
2017 }
2019 public void visitBinary(JCBinary tree) {
2020 OperatorSymbol operator = (OperatorSymbol)tree.operator;
2021 if (operator.opcode == string_add) {
2022 // Create a string buffer.
2023 makeStringBuffer(tree.pos());
2024 // Append all strings to buffer.
2025 appendStrings(tree);
2026 // Convert buffer to string.
2027 bufferToString(tree.pos());
2028 result = items.makeStackItem(syms.stringType);
2029 } else if (tree.hasTag(AND)) {
2030 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2031 if (!lcond.isFalse()) {
2032 Chain falseJumps = lcond.jumpFalse();
2033 code.resolve(lcond.trueJumps);
2034 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2035 result = items.
2036 makeCondItem(rcond.opcode,
2037 rcond.trueJumps,
2038 Code.mergeChains(falseJumps,
2039 rcond.falseJumps));
2040 } else {
2041 result = lcond;
2042 }
2043 } else if (tree.hasTag(OR)) {
2044 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2045 if (!lcond.isTrue()) {
2046 Chain trueJumps = lcond.jumpTrue();
2047 code.resolve(lcond.falseJumps);
2048 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2049 result = items.
2050 makeCondItem(rcond.opcode,
2051 Code.mergeChains(trueJumps, rcond.trueJumps),
2052 rcond.falseJumps);
2053 } else {
2054 result = lcond;
2055 }
2056 } else {
2057 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
2058 od.load();
2059 result = completeBinop(tree.lhs, tree.rhs, operator);
2060 }
2061 }
2062 //where
2063 /** Make a new string buffer.
2064 */
2065 void makeStringBuffer(DiagnosticPosition pos) {
2066 code.emitop2(new_, makeRef(pos, stringBufferType));
2067 code.emitop0(dup);
2068 callMethod(
2069 pos, stringBufferType, names.init, List.<Type>nil(), false);
2070 }
2072 /** Append value (on tos) to string buffer (on tos - 1).
2073 */
2074 void appendString(JCTree tree) {
2075 Type t = tree.type.baseType();
2076 if (!t.isPrimitive() && t.tsym != syms.stringType.tsym) {
2077 t = syms.objectType;
2078 }
2079 items.makeMemberItem(getStringBufferAppend(tree, t), false).invoke();
2080 }
2081 Symbol getStringBufferAppend(JCTree tree, Type t) {
2082 Assert.checkNull(t.constValue());
2083 Symbol method = stringBufferAppend.get(t);
2084 if (method == null) {
2085 method = rs.resolveInternalMethod(tree.pos(),
2086 attrEnv,
2087 stringBufferType,
2088 names.append,
2089 List.of(t),
2090 null);
2091 stringBufferAppend.put(t, method);
2092 }
2093 return method;
2094 }
2096 /** Add all strings in tree to string buffer.
2097 */
2098 void appendStrings(JCTree tree) {
2099 tree = TreeInfo.skipParens(tree);
2100 if (tree.hasTag(PLUS) && tree.type.constValue() == null) {
2101 JCBinary op = (JCBinary) tree;
2102 if (op.operator.kind == MTH &&
2103 ((OperatorSymbol) op.operator).opcode == string_add) {
2104 appendStrings(op.lhs);
2105 appendStrings(op.rhs);
2106 return;
2107 }
2108 }
2109 genExpr(tree, tree.type).load();
2110 appendString(tree);
2111 }
2113 /** Convert string buffer on tos to string.
2114 */
2115 void bufferToString(DiagnosticPosition pos) {
2116 callMethod(
2117 pos,
2118 stringBufferType,
2119 names.toString,
2120 List.<Type>nil(),
2121 false);
2122 }
2124 /** Complete generating code for operation, with left operand
2125 * already on stack.
2126 * @param lhs The tree representing the left operand.
2127 * @param rhs The tree representing the right operand.
2128 * @param operator The operator symbol.
2129 */
2130 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2131 MethodType optype = (MethodType)operator.type;
2132 int opcode = operator.opcode;
2133 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2134 rhs.type.constValue() instanceof Number &&
2135 ((Number) rhs.type.constValue()).intValue() == 0) {
2136 opcode = opcode + (ifeq - if_icmpeq);
2137 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2138 TreeInfo.isNull(rhs)) {
2139 opcode = opcode + (if_acmp_null - if_acmpeq);
2140 } else {
2141 // The expected type of the right operand is
2142 // the second parameter type of the operator, except for
2143 // shifts with long shiftcount, where we convert the opcode
2144 // to a short shift and the expected type to int.
2145 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2146 if (opcode >= ishll && opcode <= lushrl) {
2147 opcode = opcode + (ishl - ishll);
2148 rtype = syms.intType;
2149 }
2150 // Generate code for right operand and load.
2151 genExpr(rhs, rtype).load();
2152 // If there are two consecutive opcode instructions,
2153 // emit the first now.
2154 if (opcode >= (1 << preShift)) {
2155 code.emitop0(opcode >> preShift);
2156 opcode = opcode & 0xFF;
2157 }
2158 }
2159 if (opcode >= ifeq && opcode <= if_acmpne ||
2160 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2161 return items.makeCondItem(opcode);
2162 } else {
2163 code.emitop0(opcode);
2164 return items.makeStackItem(optype.restype);
2165 }
2166 }
2168 public void visitTypeCast(JCTypeCast tree) {
2169 setTypeAnnotationPositions(tree.pos);
2170 result = genExpr(tree.expr, tree.clazz.type).load();
2171 // Additional code is only needed if we cast to a reference type
2172 // which is not statically a supertype of the expression's type.
2173 // For basic types, the coerce(...) in genExpr(...) will do
2174 // the conversion.
2175 if (!tree.clazz.type.isPrimitive() &&
2176 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2177 code.emitop2(checkcast, makeRef(tree.pos(), tree.clazz.type));
2178 }
2179 }
2181 public void visitWildcard(JCWildcard tree) {
2182 throw new AssertionError(this.getClass().getName());
2183 }
2185 public void visitTypeTest(JCInstanceOf tree) {
2186 setTypeAnnotationPositions(tree.pos);
2187 genExpr(tree.expr, tree.expr.type).load();
2188 code.emitop2(instanceof_, makeRef(tree.pos(), tree.clazz.type));
2189 result = items.makeStackItem(syms.booleanType);
2190 }
2192 public void visitIndexed(JCArrayAccess tree) {
2193 genExpr(tree.indexed, tree.indexed.type).load();
2194 genExpr(tree.index, syms.intType).load();
2195 result = items.makeIndexedItem(tree.type);
2196 }
2198 public void visitIdent(JCIdent tree) {
2199 Symbol sym = tree.sym;
2200 if (tree.name == names._this || tree.name == names._super) {
2201 Item res = tree.name == names._this
2202 ? items.makeThisItem()
2203 : items.makeSuperItem();
2204 if (sym.kind == MTH) {
2205 // Generate code to address the constructor.
2206 res.load();
2207 res = items.makeMemberItem(sym, true);
2208 }
2209 result = res;
2210 } else if (sym.kind == VAR && sym.owner.kind == MTH) {
2211 result = items.makeLocalItem((VarSymbol)sym);
2212 } else if (isInvokeDynamic(sym)) {
2213 result = items.makeDynamicItem(sym);
2214 } else if ((sym.flags() & STATIC) != 0) {
2215 if (!isAccessSuper(env.enclMethod))
2216 sym = binaryQualifier(sym, env.enclClass.type);
2217 result = items.makeStaticItem(sym);
2218 } else {
2219 items.makeThisItem().load();
2220 sym = binaryQualifier(sym, env.enclClass.type);
2221 result = items.makeMemberItem(sym, (sym.flags() & PRIVATE) != 0);
2222 }
2223 }
2225 public void visitSelect(JCFieldAccess tree) {
2226 Symbol sym = tree.sym;
2228 if (tree.name == names._class) {
2229 Assert.check(target.hasClassLiterals());
2230 code.emitop2(ldc2, makeRef(tree.pos(), tree.selected.type));
2231 result = items.makeStackItem(pt);
2232 return;
2233 }
2235 Symbol ssym = TreeInfo.symbol(tree.selected);
2237 // Are we selecting via super?
2238 boolean selectSuper =
2239 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2241 // Are we accessing a member of the superclass in an access method
2242 // resulting from a qualified super?
2243 boolean accessSuper = isAccessSuper(env.enclMethod);
2245 Item base = (selectSuper)
2246 ? items.makeSuperItem()
2247 : genExpr(tree.selected, tree.selected.type);
2249 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2250 // We are seeing a variable that is constant but its selecting
2251 // expression is not.
2252 if ((sym.flags() & STATIC) != 0) {
2253 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2254 base = base.load();
2255 base.drop();
2256 } else {
2257 base.load();
2258 genNullCheck(tree.selected.pos());
2259 }
2260 result = items.
2261 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2262 } else {
2263 if (isInvokeDynamic(sym)) {
2264 result = items.makeDynamicItem(sym);
2265 return;
2266 } else if (!accessSuper) {
2267 sym = binaryQualifier(sym, tree.selected.type);
2268 }
2269 if ((sym.flags() & STATIC) != 0) {
2270 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2271 base = base.load();
2272 base.drop();
2273 result = items.makeStaticItem(sym);
2274 } else {
2275 base.load();
2276 if (sym == syms.lengthVar) {
2277 code.emitop0(arraylength);
2278 result = items.makeStackItem(syms.intType);
2279 } else {
2280 result = items.
2281 makeMemberItem(sym,
2282 (sym.flags() & PRIVATE) != 0 ||
2283 selectSuper || accessSuper);
2284 }
2285 }
2286 }
2287 }
2289 public boolean isInvokeDynamic(Symbol sym) {
2290 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
2291 }
2293 public void visitLiteral(JCLiteral tree) {
2294 if (tree.type.hasTag(BOT)) {
2295 code.emitop0(aconst_null);
2296 if (types.dimensions(pt) > 1) {
2297 code.emitop2(checkcast, makeRef(tree.pos(), pt));
2298 result = items.makeStackItem(pt);
2299 } else {
2300 result = items.makeStackItem(tree.type);
2301 }
2302 }
2303 else
2304 result = items.makeImmediateItem(tree.type, tree.value);
2305 }
2307 public void visitLetExpr(LetExpr tree) {
2308 int limit = code.nextreg;
2309 genStats(tree.defs, env);
2310 result = genExpr(tree.expr, tree.expr.type).load();
2311 code.endScopes(limit);
2312 }
2314 private void generateReferencesToPrunedTree(ClassSymbol classSymbol, Pool pool) {
2315 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
2316 if (prunedInfo != null) {
2317 for (JCTree prunedTree: prunedInfo) {
2318 prunedTree.accept(classReferenceVisitor);
2319 }
2320 }
2321 }
2323 /* ************************************************************************
2324 * main method
2325 *************************************************************************/
2327 /** Generate code for a class definition.
2328 * @param env The attribution environment that belongs to the
2329 * outermost class containing this class definition.
2330 * We need this for resolving some additional symbols.
2331 * @param cdef The tree representing the class definition.
2332 * @return True if code is generated with no errors.
2333 */
2334 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2335 try {
2336 attrEnv = env;
2337 ClassSymbol c = cdef.sym;
2338 this.toplevel = env.toplevel;
2339 this.endPosTable = toplevel.endPositions;
2340 // If this is a class definition requiring Miranda methods,
2341 // add them.
2342 if (generateIproxies &&
2343 (c.flags() & (INTERFACE|ABSTRACT)) == ABSTRACT
2344 && !allowGenerics // no Miranda methods available with generics
2345 )
2346 implementInterfaceMethods(c);
2347 cdef.defs = normalizeDefs(cdef.defs, c);
2348 c.pool = pool;
2349 pool.reset();
2350 generateReferencesToPrunedTree(c, pool);
2351 Env<GenContext> localEnv =
2352 new Env<GenContext>(cdef, new GenContext());
2353 localEnv.toplevel = env.toplevel;
2354 localEnv.enclClass = cdef;
2355 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2356 genDef(l.head, localEnv);
2357 }
2358 if (pool.numEntries() > Pool.MAX_ENTRIES) {
2359 log.error(cdef.pos(), "limit.pool");
2360 nerrs++;
2361 }
2362 if (nerrs != 0) {
2363 // if errors, discard code
2364 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2365 if (l.head.hasTag(METHODDEF))
2366 ((JCMethodDecl) l.head).sym.code = null;
2367 }
2368 }
2369 cdef.defs = List.nil(); // discard trees
2370 return nerrs == 0;
2371 } finally {
2372 // note: this method does NOT support recursion.
2373 attrEnv = null;
2374 this.env = null;
2375 toplevel = null;
2376 endPosTable = null;
2377 nerrs = 0;
2378 }
2379 }
2381 /* ************************************************************************
2382 * Auxiliary classes
2383 *************************************************************************/
2385 /** An abstract class for finalizer generation.
2386 */
2387 abstract class GenFinalizer {
2388 /** Generate code to clean up when unwinding. */
2389 abstract void gen();
2391 /** Generate code to clean up at last. */
2392 abstract void genLast();
2394 /** Does this finalizer have some nontrivial cleanup to perform? */
2395 boolean hasFinalizer() { return true; }
2396 }
2398 /** code generation contexts,
2399 * to be used as type parameter for environments.
2400 */
2401 static class GenContext {
2403 /** A chain for all unresolved jumps that exit the current environment.
2404 */
2405 Chain exit = null;
2407 /** A chain for all unresolved jumps that continue in the
2408 * current environment.
2409 */
2410 Chain cont = null;
2412 /** A closure that generates the finalizer of the current environment.
2413 * Only set for Synchronized and Try contexts.
2414 */
2415 GenFinalizer finalize = null;
2417 /** Is this a switch statement? If so, allocate registers
2418 * even when the variable declaration is unreachable.
2419 */
2420 boolean isSwitch = false;
2422 /** A list buffer containing all gaps in the finalizer range,
2423 * where a catch all exception should not apply.
2424 */
2425 ListBuffer<Integer> gaps = null;
2427 /** Add given chain to exit chain.
2428 */
2429 void addExit(Chain c) {
2430 exit = Code.mergeChains(c, exit);
2431 }
2433 /** Add given chain to cont chain.
2434 */
2435 void addCont(Chain c) {
2436 cont = Code.mergeChains(c, cont);
2437 }
2438 }
2439 }
