Wed, 23 Jan 2013 13:27:24 -0800
8006775: JSR 308: Compiler changes in JDK8
Reviewed-by: jjg
Contributed-by: mernst@cs.washington.edu, wmdietl@cs.washington.edu, mpapi@csail.mit.edu, mahmood@notnoop.com
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, 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(JCTree, 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.hasTag(Tag.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.hasTag(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(JCTree,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.hasTag(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 class for expressions which might be constant expressions.
823 * This class is a subset of TreeScanner. Intended to visit trees pruned by
824 * Lower as long as constant expressions looking for references to any
825 * ClassSymbol. Any such reference will be added to the constant pool so
826 * automated tools can detect class dependencies better.
827 */
828 class ClassReferenceVisitor extends JCTree.Visitor {
830 @Override
831 public void visitTree(JCTree tree) {}
833 @Override
834 public void visitBinary(JCBinary tree) {
835 tree.lhs.accept(this);
836 tree.rhs.accept(this);
837 }
839 @Override
840 public void visitSelect(JCFieldAccess tree) {
841 if (tree.selected.type.hasTag(CLASS)) {
842 makeRef(tree.selected.pos(), tree.selected.type);
843 }
844 }
846 @Override
847 public void visitIdent(JCIdent tree) {
848 if (tree.sym.owner instanceof ClassSymbol) {
849 pool.put(tree.sym.owner);
850 }
851 }
853 @Override
854 public void visitConditional(JCConditional tree) {
855 tree.cond.accept(this);
856 tree.truepart.accept(this);
857 tree.falsepart.accept(this);
858 }
860 @Override
861 public void visitUnary(JCUnary tree) {
862 tree.arg.accept(this);
863 }
865 @Override
866 public void visitParens(JCParens tree) {
867 tree.expr.accept(this);
868 }
870 @Override
871 public void visitTypeCast(JCTypeCast tree) {
872 tree.expr.accept(this);
873 }
874 }
876 private ClassReferenceVisitor classReferenceVisitor = new ClassReferenceVisitor();
878 /** Visitor method: generate code for an expression, catching and reporting
879 * any completion failures.
880 * @param tree The expression to be visited.
881 * @param pt The expression's expected type (proto-type).
882 */
883 public Item genExpr(JCTree tree, Type pt) {
884 Type prevPt = this.pt;
885 try {
886 if (tree.type.constValue() != null) {
887 // Short circuit any expressions which are constants
888 tree.accept(classReferenceVisitor);
889 checkStringConstant(tree.pos(), tree.type.constValue());
890 result = items.makeImmediateItem(tree.type, tree.type.constValue());
891 } else {
892 this.pt = pt;
893 tree.accept(this);
894 }
895 return result.coerce(pt);
896 } catch (CompletionFailure ex) {
897 chk.completionError(tree.pos(), ex);
898 code.state.stacksize = 1;
899 return items.makeStackItem(pt);
900 } finally {
901 this.pt = prevPt;
902 }
903 }
905 /** Derived visitor method: generate code for a list of method arguments.
906 * @param trees The argument expressions to be visited.
907 * @param pts The expression's expected types (i.e. the formal parameter
908 * types of the invoked method).
909 */
910 public void genArgs(List<JCExpression> trees, List<Type> pts) {
911 for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail) {
912 genExpr(l.head, pts.head).load();
913 pts = pts.tail;
914 }
915 // require lists be of same length
916 Assert.check(pts.isEmpty());
917 }
919 /* ************************************************************************
920 * Visitor methods for statements and definitions
921 *************************************************************************/
923 /** Thrown when the byte code size exceeds limit.
924 */
925 public static class CodeSizeOverflow extends RuntimeException {
926 private static final long serialVersionUID = 0;
927 public CodeSizeOverflow() {}
928 }
930 public void visitMethodDef(JCMethodDecl tree) {
931 // Create a new local environment that points pack at method
932 // definition.
933 Env<GenContext> localEnv = env.dup(tree);
934 localEnv.enclMethod = tree;
936 // The expected type of every return statement in this method
937 // is the method's return type.
938 this.pt = tree.sym.erasure(types).getReturnType();
940 checkDimension(tree.pos(), tree.sym.erasure(types));
941 genMethod(tree, localEnv, false);
942 }
943 //where
944 /** Generate code for a method.
945 * @param tree The tree representing the method definition.
946 * @param env The environment current for the method body.
947 * @param fatcode A flag that indicates whether all jumps are
948 * within 32K. We first invoke this method under
949 * the assumption that fatcode == false, i.e. all
950 * jumps are within 32K. If this fails, fatcode
951 * is set to true and we try again.
952 */
953 void genMethod(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
954 MethodSymbol meth = tree.sym;
955 // System.err.println("Generating " + meth + " in " + meth.owner); //DEBUG
956 if (Code.width(types.erasure(env.enclMethod.sym.type).getParameterTypes()) +
957 (((tree.mods.flags & STATIC) == 0 || meth.isConstructor()) ? 1 : 0) >
958 ClassFile.MAX_PARAMETERS) {
959 log.error(tree.pos(), "limit.parameters");
960 nerrs++;
961 }
963 else if (tree.body != null) {
964 // Create a new code structure and initialize it.
965 int startpcCrt = initCode(tree, env, fatcode);
967 try {
968 genStat(tree.body, env);
969 } catch (CodeSizeOverflow e) {
970 // Failed due to code limit, try again with jsr/ret
971 startpcCrt = initCode(tree, env, fatcode);
972 genStat(tree.body, env);
973 }
975 if (code.state.stacksize != 0) {
976 log.error(tree.body.pos(), "stack.sim.error", tree);
977 throw new AssertionError();
978 }
980 // If last statement could complete normally, insert a
981 // return at the end.
982 if (code.isAlive()) {
983 code.statBegin(TreeInfo.endPos(tree.body));
984 if (env.enclMethod == null ||
985 env.enclMethod.sym.type.getReturnType().hasTag(VOID)) {
986 code.emitop0(return_);
987 } else {
988 // sometime dead code seems alive (4415991);
989 // generate a small loop instead
990 int startpc = code.entryPoint();
991 CondItem c = items.makeCondItem(goto_);
992 code.resolve(c.jumpTrue(), startpc);
993 }
994 }
995 if (genCrt)
996 code.crt.put(tree.body,
997 CRT_BLOCK,
998 startpcCrt,
999 code.curPc());
1001 code.endScopes(0);
1003 // If we exceeded limits, panic
1004 if (code.checkLimits(tree.pos(), log)) {
1005 nerrs++;
1006 return;
1007 }
1009 // If we generated short code but got a long jump, do it again
1010 // with fatCode = true.
1011 if (!fatcode && code.fatcode) genMethod(tree, env, true);
1013 // Clean up
1014 if(stackMap == StackMapFormat.JSR202) {
1015 code.lastFrame = null;
1016 code.frameBeforeLast = null;
1017 }
1019 // Compress exception table
1020 code.compressCatchTable();
1022 // Fill in type annotation positions for exception parameters
1023 code.fillExceptionParameterPositions();
1024 }
1025 }
1027 private int initCode(JCMethodDecl tree, Env<GenContext> env, boolean fatcode) {
1028 MethodSymbol meth = tree.sym;
1030 // Create a new code structure.
1031 meth.code = code = new Code(meth,
1032 fatcode,
1033 lineDebugInfo ? toplevel.lineMap : null,
1034 varDebugInfo,
1035 stackMap,
1036 debugCode,
1037 genCrt ? new CRTable(tree, env.toplevel.endPositions)
1038 : null,
1039 syms,
1040 types,
1041 pool);
1042 items = new Items(pool, code, syms, types);
1043 if (code.debugCode)
1044 System.err.println(meth + " for body " + tree);
1046 // If method is not static, create a new local variable address
1047 // for `this'.
1048 if ((tree.mods.flags & STATIC) == 0) {
1049 Type selfType = meth.owner.type;
1050 if (meth.isConstructor() && selfType != syms.objectType)
1051 selfType = UninitializedType.uninitializedThis(selfType);
1052 code.setDefined(
1053 code.newLocal(
1054 new VarSymbol(FINAL, names._this, selfType, meth.owner)));
1055 }
1057 // Mark all parameters as defined from the beginning of
1058 // the method.
1059 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
1060 checkDimension(l.head.pos(), l.head.sym.type);
1061 code.setDefined(code.newLocal(l.head.sym));
1062 }
1064 // Get ready to generate code for method body.
1065 int startpcCrt = genCrt ? code.curPc() : 0;
1066 code.entryPoint();
1068 // Suppress initial stackmap
1069 code.pendingStackMap = false;
1071 return startpcCrt;
1072 }
1074 public void visitVarDef(JCVariableDecl tree) {
1075 VarSymbol v = tree.sym;
1076 code.newLocal(v);
1077 if (tree.init != null) {
1078 checkStringConstant(tree.init.pos(), v.getConstValue());
1079 if (v.getConstValue() == null || varDebugInfo) {
1080 genExpr(tree.init, v.erasure(types)).load();
1081 items.makeLocalItem(v).store();
1082 }
1083 }
1084 checkDimension(tree.pos(), v.type);
1085 }
1087 public void visitSkip(JCSkip tree) {
1088 }
1090 public void visitBlock(JCBlock tree) {
1091 int limit = code.nextreg;
1092 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1093 genStats(tree.stats, localEnv);
1094 // End the scope of all block-local variables in variable info.
1095 if (!env.tree.hasTag(METHODDEF)) {
1096 code.statBegin(tree.endpos);
1097 code.endScopes(limit);
1098 code.pendingStatPos = Position.NOPOS;
1099 }
1100 }
1102 public void visitDoLoop(JCDoWhileLoop tree) {
1103 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), false);
1104 }
1106 public void visitWhileLoop(JCWhileLoop tree) {
1107 genLoop(tree, tree.body, tree.cond, List.<JCExpressionStatement>nil(), true);
1108 }
1110 public void visitForLoop(JCForLoop tree) {
1111 int limit = code.nextreg;
1112 genStats(tree.init, env);
1113 genLoop(tree, tree.body, tree.cond, tree.step, true);
1114 code.endScopes(limit);
1115 }
1116 //where
1117 /** Generate code for a loop.
1118 * @param loop The tree representing the loop.
1119 * @param body The loop's body.
1120 * @param cond The loop's controling condition.
1121 * @param step "Step" statements to be inserted at end of
1122 * each iteration.
1123 * @param testFirst True if the loop test belongs before the body.
1124 */
1125 private void genLoop(JCStatement loop,
1126 JCStatement body,
1127 JCExpression cond,
1128 List<JCExpressionStatement> step,
1129 boolean testFirst) {
1130 Env<GenContext> loopEnv = env.dup(loop, new GenContext());
1131 int startpc = code.entryPoint();
1132 if (testFirst) {
1133 CondItem c;
1134 if (cond != null) {
1135 code.statBegin(cond.pos);
1136 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1137 } else {
1138 c = items.makeCondItem(goto_);
1139 }
1140 Chain loopDone = c.jumpFalse();
1141 code.resolve(c.trueJumps);
1142 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1143 code.resolve(loopEnv.info.cont);
1144 genStats(step, loopEnv);
1145 code.resolve(code.branch(goto_), startpc);
1146 code.resolve(loopDone);
1147 } else {
1148 genStat(body, loopEnv, CRT_STATEMENT | CRT_FLOW_TARGET);
1149 code.resolve(loopEnv.info.cont);
1150 genStats(step, loopEnv);
1151 CondItem c;
1152 if (cond != null) {
1153 code.statBegin(cond.pos);
1154 c = genCond(TreeInfo.skipParens(cond), CRT_FLOW_CONTROLLER);
1155 } else {
1156 c = items.makeCondItem(goto_);
1157 }
1158 code.resolve(c.jumpTrue(), startpc);
1159 code.resolve(c.falseJumps);
1160 }
1161 code.resolve(loopEnv.info.exit);
1162 }
1164 public void visitForeachLoop(JCEnhancedForLoop tree) {
1165 throw new AssertionError(); // should have been removed by Lower.
1166 }
1168 public void visitLabelled(JCLabeledStatement tree) {
1169 Env<GenContext> localEnv = env.dup(tree, new GenContext());
1170 genStat(tree.body, localEnv, CRT_STATEMENT);
1171 code.resolve(localEnv.info.exit);
1172 }
1174 public void visitSwitch(JCSwitch tree) {
1175 int limit = code.nextreg;
1176 Assert.check(!tree.selector.type.hasTag(CLASS));
1177 int startpcCrt = genCrt ? code.curPc() : 0;
1178 Item sel = genExpr(tree.selector, syms.intType);
1179 List<JCCase> cases = tree.cases;
1180 if (cases.isEmpty()) {
1181 // We are seeing: switch <sel> {}
1182 sel.load().drop();
1183 if (genCrt)
1184 code.crt.put(TreeInfo.skipParens(tree.selector),
1185 CRT_FLOW_CONTROLLER, startpcCrt, code.curPc());
1186 } else {
1187 // We are seeing a nonempty switch.
1188 sel.load();
1189 if (genCrt)
1190 code.crt.put(TreeInfo.skipParens(tree.selector),
1191 CRT_FLOW_CONTROLLER, startpcCrt, code.curPc());
1192 Env<GenContext> switchEnv = env.dup(tree, new GenContext());
1193 switchEnv.info.isSwitch = true;
1195 // Compute number of labels and minimum and maximum label values.
1196 // For each case, store its label in an array.
1197 int lo = Integer.MAX_VALUE; // minimum label.
1198 int hi = Integer.MIN_VALUE; // maximum label.
1199 int nlabels = 0; // number of labels.
1201 int[] labels = new int[cases.length()]; // the label array.
1202 int defaultIndex = -1; // the index of the default clause.
1204 List<JCCase> l = cases;
1205 for (int i = 0; i < labels.length; i++) {
1206 if (l.head.pat != null) {
1207 int val = ((Number)l.head.pat.type.constValue()).intValue();
1208 labels[i] = val;
1209 if (val < lo) lo = val;
1210 if (hi < val) hi = val;
1211 nlabels++;
1212 } else {
1213 Assert.check(defaultIndex == -1);
1214 defaultIndex = i;
1215 }
1216 l = l.tail;
1217 }
1219 // Determine whether to issue a tableswitch or a lookupswitch
1220 // instruction.
1221 long table_space_cost = 4 + ((long) hi - lo + 1); // words
1222 long table_time_cost = 3; // comparisons
1223 long lookup_space_cost = 3 + 2 * (long) nlabels;
1224 long lookup_time_cost = nlabels;
1225 int opcode =
1226 nlabels > 0 &&
1227 table_space_cost + 3 * table_time_cost <=
1228 lookup_space_cost + 3 * lookup_time_cost
1229 ?
1230 tableswitch : lookupswitch;
1232 int startpc = code.curPc(); // the position of the selector operation
1233 code.emitop0(opcode);
1234 code.align(4);
1235 int tableBase = code.curPc(); // the start of the jump table
1236 int[] offsets = null; // a table of offsets for a lookupswitch
1237 code.emit4(-1); // leave space for default offset
1238 if (opcode == tableswitch) {
1239 code.emit4(lo); // minimum label
1240 code.emit4(hi); // maximum label
1241 for (long i = lo; i <= hi; i++) { // leave space for jump table
1242 code.emit4(-1);
1243 }
1244 } else {
1245 code.emit4(nlabels); // number of labels
1246 for (int i = 0; i < nlabels; i++) {
1247 code.emit4(-1); code.emit4(-1); // leave space for lookup table
1248 }
1249 offsets = new int[labels.length];
1250 }
1251 Code.State stateSwitch = code.state.dup();
1252 code.markDead();
1254 // For each case do:
1255 l = cases;
1256 for (int i = 0; i < labels.length; i++) {
1257 JCCase c = l.head;
1258 l = l.tail;
1260 int pc = code.entryPoint(stateSwitch);
1261 // Insert offset directly into code or else into the
1262 // offsets table.
1263 if (i != defaultIndex) {
1264 if (opcode == tableswitch) {
1265 code.put4(
1266 tableBase + 4 * (labels[i] - lo + 3),
1267 pc - startpc);
1268 } else {
1269 offsets[i] = pc - startpc;
1270 }
1271 } else {
1272 code.put4(tableBase, pc - startpc);
1273 }
1275 // Generate code for the statements in this case.
1276 genStats(c.stats, switchEnv, CRT_FLOW_TARGET);
1277 }
1279 // Resolve all breaks.
1280 code.resolve(switchEnv.info.exit);
1282 // If we have not set the default offset, we do so now.
1283 if (code.get4(tableBase) == -1) {
1284 code.put4(tableBase, code.entryPoint(stateSwitch) - startpc);
1285 }
1287 if (opcode == tableswitch) {
1288 // Let any unfilled slots point to the default case.
1289 int defaultOffset = code.get4(tableBase);
1290 for (long i = lo; i <= hi; i++) {
1291 int t = (int)(tableBase + 4 * (i - lo + 3));
1292 if (code.get4(t) == -1)
1293 code.put4(t, defaultOffset);
1294 }
1295 } else {
1296 // Sort non-default offsets and copy into lookup table.
1297 if (defaultIndex >= 0)
1298 for (int i = defaultIndex; i < labels.length - 1; i++) {
1299 labels[i] = labels[i+1];
1300 offsets[i] = offsets[i+1];
1301 }
1302 if (nlabels > 0)
1303 qsort2(labels, offsets, 0, nlabels - 1);
1304 for (int i = 0; i < nlabels; i++) {
1305 int caseidx = tableBase + 8 * (i + 1);
1306 code.put4(caseidx, labels[i]);
1307 code.put4(caseidx + 4, offsets[i]);
1308 }
1309 }
1310 }
1311 code.endScopes(limit);
1312 }
1313 //where
1314 /** Sort (int) arrays of keys and values
1315 */
1316 static void qsort2(int[] keys, int[] values, int lo, int hi) {
1317 int i = lo;
1318 int j = hi;
1319 int pivot = keys[(i+j)/2];
1320 do {
1321 while (keys[i] < pivot) i++;
1322 while (pivot < keys[j]) j--;
1323 if (i <= j) {
1324 int temp1 = keys[i];
1325 keys[i] = keys[j];
1326 keys[j] = temp1;
1327 int temp2 = values[i];
1328 values[i] = values[j];
1329 values[j] = temp2;
1330 i++;
1331 j--;
1332 }
1333 } while (i <= j);
1334 if (lo < j) qsort2(keys, values, lo, j);
1335 if (i < hi) qsort2(keys, values, i, hi);
1336 }
1338 public void visitSynchronized(JCSynchronized tree) {
1339 int limit = code.nextreg;
1340 // Generate code to evaluate lock and save in temporary variable.
1341 final LocalItem lockVar = makeTemp(syms.objectType);
1342 genExpr(tree.lock, tree.lock.type).load().duplicate();
1343 lockVar.store();
1345 // Generate code to enter monitor.
1346 code.emitop0(monitorenter);
1347 code.state.lock(lockVar.reg);
1349 // Generate code for a try statement with given body, no catch clauses
1350 // in a new environment with the "exit-monitor" operation as finalizer.
1351 final Env<GenContext> syncEnv = env.dup(tree, new GenContext());
1352 syncEnv.info.finalize = new GenFinalizer() {
1353 void gen() {
1354 genLast();
1355 Assert.check(syncEnv.info.gaps.length() % 2 == 0);
1356 syncEnv.info.gaps.append(code.curPc());
1357 }
1358 void genLast() {
1359 if (code.isAlive()) {
1360 lockVar.load();
1361 code.emitop0(monitorexit);
1362 code.state.unlock(lockVar.reg);
1363 }
1364 }
1365 };
1366 syncEnv.info.gaps = new ListBuffer<Integer>();
1367 genTry(tree.body, List.<JCCatch>nil(), syncEnv);
1368 code.endScopes(limit);
1369 }
1371 public void visitTry(final JCTry tree) {
1372 // Generate code for a try statement with given body and catch clauses,
1373 // in a new environment which calls the finally block if there is one.
1374 final Env<GenContext> tryEnv = env.dup(tree, new GenContext());
1375 final Env<GenContext> oldEnv = env;
1376 if (!useJsrLocally) {
1377 useJsrLocally =
1378 (stackMap == StackMapFormat.NONE) &&
1379 (jsrlimit <= 0 ||
1380 jsrlimit < 100 &&
1381 estimateCodeComplexity(tree.finalizer)>jsrlimit);
1382 }
1383 tryEnv.info.finalize = new GenFinalizer() {
1384 void gen() {
1385 if (useJsrLocally) {
1386 if (tree.finalizer != null) {
1387 Code.State jsrState = code.state.dup();
1388 jsrState.push(Code.jsrReturnValue);
1389 tryEnv.info.cont =
1390 new Chain(code.emitJump(jsr),
1391 tryEnv.info.cont,
1392 jsrState);
1393 }
1394 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1395 tryEnv.info.gaps.append(code.curPc());
1396 } else {
1397 Assert.check(tryEnv.info.gaps.length() % 2 == 0);
1398 tryEnv.info.gaps.append(code.curPc());
1399 genLast();
1400 }
1401 }
1402 void genLast() {
1403 if (tree.finalizer != null)
1404 genStat(tree.finalizer, oldEnv, CRT_BLOCK);
1405 }
1406 boolean hasFinalizer() {
1407 return tree.finalizer != null;
1408 }
1409 };
1410 tryEnv.info.gaps = new ListBuffer<Integer>();
1411 genTry(tree.body, tree.catchers, tryEnv);
1412 }
1413 //where
1414 /** Generate code for a try or synchronized statement
1415 * @param body The body of the try or synchronized statement.
1416 * @param catchers The lis of catch clauses.
1417 * @param env the environment current for the body.
1418 */
1419 void genTry(JCTree body, List<JCCatch> catchers, Env<GenContext> env) {
1420 int limit = code.nextreg;
1421 int startpc = code.curPc();
1422 Code.State stateTry = code.state.dup();
1423 genStat(body, env, CRT_BLOCK);
1424 int endpc = code.curPc();
1425 boolean hasFinalizer =
1426 env.info.finalize != null &&
1427 env.info.finalize.hasFinalizer();
1428 List<Integer> gaps = env.info.gaps.toList();
1429 code.statBegin(TreeInfo.endPos(body));
1430 genFinalizer(env);
1431 code.statBegin(TreeInfo.endPos(env.tree));
1432 Chain exitChain = code.branch(goto_);
1433 endFinalizerGap(env);
1434 if (startpc != endpc) for (List<JCCatch> l = catchers; l.nonEmpty(); l = l.tail) {
1435 // start off with exception on stack
1436 code.entryPoint(stateTry, l.head.param.sym.type);
1437 genCatch(l.head, env, startpc, endpc, gaps);
1438 genFinalizer(env);
1439 if (hasFinalizer || l.tail.nonEmpty()) {
1440 code.statBegin(TreeInfo.endPos(env.tree));
1441 exitChain = Code.mergeChains(exitChain,
1442 code.branch(goto_));
1443 }
1444 endFinalizerGap(env);
1445 }
1446 if (hasFinalizer) {
1447 // Create a new register segement to avoid allocating
1448 // the same variables in finalizers and other statements.
1449 code.newRegSegment();
1451 // Add a catch-all clause.
1453 // start off with exception on stack
1454 int catchallpc = code.entryPoint(stateTry, syms.throwableType);
1456 // Register all exception ranges for catch all clause.
1457 // The range of the catch all clause is from the beginning
1458 // of the try or synchronized block until the present
1459 // code pointer excluding all gaps in the current
1460 // environment's GenContext.
1461 int startseg = startpc;
1462 while (env.info.gaps.nonEmpty()) {
1463 int endseg = env.info.gaps.next().intValue();
1464 registerCatch(body.pos(), startseg, endseg,
1465 catchallpc, 0);
1466 startseg = env.info.gaps.next().intValue();
1467 }
1468 code.statBegin(TreeInfo.finalizerPos(env.tree));
1469 code.markStatBegin();
1471 Item excVar = makeTemp(syms.throwableType);
1472 excVar.store();
1473 genFinalizer(env);
1474 excVar.load();
1475 registerCatch(body.pos(), startseg,
1476 env.info.gaps.next().intValue(),
1477 catchallpc, 0);
1478 code.emitop0(athrow);
1479 code.markDead();
1481 // If there are jsr's to this finalizer, ...
1482 if (env.info.cont != null) {
1483 // Resolve all jsr's.
1484 code.resolve(env.info.cont);
1486 // Mark statement line number
1487 code.statBegin(TreeInfo.finalizerPos(env.tree));
1488 code.markStatBegin();
1490 // Save return address.
1491 LocalItem retVar = makeTemp(syms.throwableType);
1492 retVar.store();
1494 // Generate finalizer code.
1495 env.info.finalize.genLast();
1497 // Return.
1498 code.emitop1w(ret, retVar.reg);
1499 code.markDead();
1500 }
1501 }
1502 // Resolve all breaks.
1503 code.resolve(exitChain);
1505 code.endScopes(limit);
1506 }
1508 /** Generate code for a catch clause.
1509 * @param tree The catch clause.
1510 * @param env The environment current in the enclosing try.
1511 * @param startpc Start pc of try-block.
1512 * @param endpc End pc of try-block.
1513 */
1514 void genCatch(JCCatch tree,
1515 Env<GenContext> env,
1516 int startpc, int endpc,
1517 List<Integer> gaps) {
1518 if (startpc != endpc) {
1519 List<JCExpression> subClauses = TreeInfo.isMultiCatch(tree) ?
1520 ((JCTypeUnion)tree.param.vartype).alternatives :
1521 List.of(tree.param.vartype);
1522 while (gaps.nonEmpty()) {
1523 for (JCExpression subCatch : subClauses) {
1524 int catchType = makeRef(tree.pos(), subCatch.type);
1525 int end = gaps.head.intValue();
1526 registerCatch(tree.pos(),
1527 startpc, end, code.curPc(),
1528 catchType);
1529 }
1530 gaps = gaps.tail;
1531 startpc = gaps.head.intValue();
1532 gaps = gaps.tail;
1533 }
1534 if (startpc < endpc) {
1535 for (JCExpression subCatch : subClauses) {
1536 int catchType = makeRef(tree.pos(), subCatch.type);
1537 registerCatch(tree.pos(),
1538 startpc, endpc, code.curPc(),
1539 catchType);
1540 }
1541 }
1542 VarSymbol exparam = tree.param.sym;
1543 code.statBegin(tree.pos);
1544 code.markStatBegin();
1545 int limit = code.nextreg;
1546 int exlocal = code.newLocal(exparam);
1547 items.makeLocalItem(exparam).store();
1548 code.statBegin(TreeInfo.firstStatPos(tree.body));
1549 genStat(tree.body, env, CRT_BLOCK);
1550 code.endScopes(limit);
1551 code.statBegin(TreeInfo.endPos(tree.body));
1552 }
1553 }
1555 /** Register a catch clause in the "Exceptions" code-attribute.
1556 */
1557 void registerCatch(DiagnosticPosition pos,
1558 int startpc, int endpc,
1559 int handler_pc, int catch_type) {
1560 char startpc1 = (char)startpc;
1561 char endpc1 = (char)endpc;
1562 char handler_pc1 = (char)handler_pc;
1563 if (startpc1 == startpc &&
1564 endpc1 == endpc &&
1565 handler_pc1 == handler_pc) {
1566 code.addCatch(startpc1, endpc1, handler_pc1,
1567 (char)catch_type);
1568 } else {
1569 if (!useJsrLocally && !target.generateStackMapTable()) {
1570 useJsrLocally = true;
1571 throw new CodeSizeOverflow();
1572 } else {
1573 log.error(pos, "limit.code.too.large.for.try.stmt");
1574 nerrs++;
1575 }
1576 }
1577 }
1579 /** Very roughly estimate the number of instructions needed for
1580 * the given tree.
1581 */
1582 int estimateCodeComplexity(JCTree tree) {
1583 if (tree == null) return 0;
1584 class ComplexityScanner extends TreeScanner {
1585 int complexity = 0;
1586 public void scan(JCTree tree) {
1587 if (complexity > jsrlimit) return;
1588 super.scan(tree);
1589 }
1590 public void visitClassDef(JCClassDecl tree) {}
1591 public void visitDoLoop(JCDoWhileLoop tree)
1592 { super.visitDoLoop(tree); complexity++; }
1593 public void visitWhileLoop(JCWhileLoop tree)
1594 { super.visitWhileLoop(tree); complexity++; }
1595 public void visitForLoop(JCForLoop tree)
1596 { super.visitForLoop(tree); complexity++; }
1597 public void visitSwitch(JCSwitch tree)
1598 { super.visitSwitch(tree); complexity+=5; }
1599 public void visitCase(JCCase tree)
1600 { super.visitCase(tree); complexity++; }
1601 public void visitSynchronized(JCSynchronized tree)
1602 { super.visitSynchronized(tree); complexity+=6; }
1603 public void visitTry(JCTry tree)
1604 { super.visitTry(tree);
1605 if (tree.finalizer != null) complexity+=6; }
1606 public void visitCatch(JCCatch tree)
1607 { super.visitCatch(tree); complexity+=2; }
1608 public void visitConditional(JCConditional tree)
1609 { super.visitConditional(tree); complexity+=2; }
1610 public void visitIf(JCIf tree)
1611 { super.visitIf(tree); complexity+=2; }
1612 // note: for break, continue, and return we don't take unwind() into account.
1613 public void visitBreak(JCBreak tree)
1614 { super.visitBreak(tree); complexity+=1; }
1615 public void visitContinue(JCContinue tree)
1616 { super.visitContinue(tree); complexity+=1; }
1617 public void visitReturn(JCReturn tree)
1618 { super.visitReturn(tree); complexity+=1; }
1619 public void visitThrow(JCThrow tree)
1620 { super.visitThrow(tree); complexity+=1; }
1621 public void visitAssert(JCAssert tree)
1622 { super.visitAssert(tree); complexity+=5; }
1623 public void visitApply(JCMethodInvocation tree)
1624 { super.visitApply(tree); complexity+=2; }
1625 public void visitNewClass(JCNewClass tree)
1626 { scan(tree.encl); scan(tree.args); complexity+=2; }
1627 public void visitNewArray(JCNewArray tree)
1628 { super.visitNewArray(tree); complexity+=5; }
1629 public void visitAssign(JCAssign tree)
1630 { super.visitAssign(tree); complexity+=1; }
1631 public void visitAssignop(JCAssignOp tree)
1632 { super.visitAssignop(tree); complexity+=2; }
1633 public void visitUnary(JCUnary tree)
1634 { complexity+=1;
1635 if (tree.type.constValue() == null) super.visitUnary(tree); }
1636 public void visitBinary(JCBinary tree)
1637 { complexity+=1;
1638 if (tree.type.constValue() == null) super.visitBinary(tree); }
1639 public void visitTypeTest(JCInstanceOf tree)
1640 { super.visitTypeTest(tree); complexity+=1; }
1641 public void visitIndexed(JCArrayAccess tree)
1642 { super.visitIndexed(tree); complexity+=1; }
1643 public void visitSelect(JCFieldAccess tree)
1644 { super.visitSelect(tree);
1645 if (tree.sym.kind == VAR) complexity+=1; }
1646 public void visitIdent(JCIdent tree) {
1647 if (tree.sym.kind == VAR) {
1648 complexity+=1;
1649 if (tree.type.constValue() == null &&
1650 tree.sym.owner.kind == TYP)
1651 complexity+=1;
1652 }
1653 }
1654 public void visitLiteral(JCLiteral tree)
1655 { complexity+=1; }
1656 public void visitTree(JCTree tree) {}
1657 public void visitWildcard(JCWildcard tree) {
1658 throw new AssertionError(this.getClass().getName());
1659 }
1660 }
1661 ComplexityScanner scanner = new ComplexityScanner();
1662 tree.accept(scanner);
1663 return scanner.complexity;
1664 }
1666 public void visitIf(JCIf tree) {
1667 int limit = code.nextreg;
1668 Chain thenExit = null;
1669 CondItem c = genCond(TreeInfo.skipParens(tree.cond),
1670 CRT_FLOW_CONTROLLER);
1671 Chain elseChain = c.jumpFalse();
1672 if (!c.isFalse()) {
1673 code.resolve(c.trueJumps);
1674 genStat(tree.thenpart, env, CRT_STATEMENT | CRT_FLOW_TARGET);
1675 thenExit = code.branch(goto_);
1676 }
1677 if (elseChain != null) {
1678 code.resolve(elseChain);
1679 if (tree.elsepart != null)
1680 genStat(tree.elsepart, env,CRT_STATEMENT | CRT_FLOW_TARGET);
1681 }
1682 code.resolve(thenExit);
1683 code.endScopes(limit);
1684 }
1686 public void visitExec(JCExpressionStatement tree) {
1687 // Optimize x++ to ++x and x-- to --x.
1688 JCExpression e = tree.expr;
1689 switch (e.getTag()) {
1690 case POSTINC:
1691 ((JCUnary) e).setTag(PREINC);
1692 break;
1693 case POSTDEC:
1694 ((JCUnary) e).setTag(PREDEC);
1695 break;
1696 }
1697 genExpr(tree.expr, tree.expr.type).drop();
1698 }
1700 public void visitBreak(JCBreak tree) {
1701 Env<GenContext> targetEnv = unwind(tree.target, env);
1702 Assert.check(code.state.stacksize == 0);
1703 targetEnv.info.addExit(code.branch(goto_));
1704 endFinalizerGaps(env, targetEnv);
1705 }
1707 public void visitContinue(JCContinue tree) {
1708 Env<GenContext> targetEnv = unwind(tree.target, env);
1709 Assert.check(code.state.stacksize == 0);
1710 targetEnv.info.addCont(code.branch(goto_));
1711 endFinalizerGaps(env, targetEnv);
1712 }
1714 public void visitReturn(JCReturn tree) {
1715 int limit = code.nextreg;
1716 final Env<GenContext> targetEnv;
1717 if (tree.expr != null) {
1718 Item r = genExpr(tree.expr, pt).load();
1719 if (hasFinally(env.enclMethod, env)) {
1720 r = makeTemp(pt);
1721 r.store();
1722 }
1723 targetEnv = unwind(env.enclMethod, env);
1724 r.load();
1725 code.emitop0(ireturn + Code.truncate(Code.typecode(pt)));
1726 } else {
1727 targetEnv = unwind(env.enclMethod, env);
1728 code.emitop0(return_);
1729 }
1730 endFinalizerGaps(env, targetEnv);
1731 code.endScopes(limit);
1732 }
1734 public void visitThrow(JCThrow tree) {
1735 genExpr(tree.expr, tree.expr.type).load();
1736 code.emitop0(athrow);
1737 }
1739 /* ************************************************************************
1740 * Visitor methods for expressions
1741 *************************************************************************/
1743 public void visitApply(JCMethodInvocation tree) {
1744 setTypeAnnotationPositions(tree.pos);
1745 // Generate code for method.
1746 Item m = genExpr(tree.meth, methodType);
1747 // Generate code for all arguments, where the expected types are
1748 // the parameters of the method's external type (that is, any implicit
1749 // outer instance of a super(...) call appears as first parameter).
1750 genArgs(tree.args,
1751 TreeInfo.symbol(tree.meth).externalType(types).getParameterTypes());
1752 code.statBegin(tree.pos);
1753 code.markStatBegin();
1754 result = m.invoke();
1755 }
1757 public void visitConditional(JCConditional tree) {
1758 Chain thenExit = null;
1759 CondItem c = genCond(tree.cond, CRT_FLOW_CONTROLLER);
1760 Chain elseChain = c.jumpFalse();
1761 if (!c.isFalse()) {
1762 code.resolve(c.trueJumps);
1763 int startpc = genCrt ? code.curPc() : 0;
1764 genExpr(tree.truepart, pt).load();
1765 code.state.forceStackTop(tree.type);
1766 if (genCrt) code.crt.put(tree.truepart, CRT_FLOW_TARGET,
1767 startpc, code.curPc());
1768 thenExit = code.branch(goto_);
1769 }
1770 if (elseChain != null) {
1771 code.resolve(elseChain);
1772 int startpc = genCrt ? code.curPc() : 0;
1773 genExpr(tree.falsepart, pt).load();
1774 code.state.forceStackTop(tree.type);
1775 if (genCrt) code.crt.put(tree.falsepart, CRT_FLOW_TARGET,
1776 startpc, code.curPc());
1777 }
1778 code.resolve(thenExit);
1779 result = items.makeStackItem(pt);
1780 }
1782 private void setTypeAnnotationPositions(int treePos) {
1783 MethodSymbol meth = code.meth;
1785 for (Attribute.TypeCompound ta : meth.getRawTypeAttributes()) {
1786 if (ta.position.pos == treePos) {
1787 ta.position.offset = code.cp;
1788 ta.position.lvarOffset = new int[] { code.cp };
1789 ta.position.isValidOffset = true;
1790 }
1791 }
1793 if (code.meth.getKind() != javax.lang.model.element.ElementKind.CONSTRUCTOR
1794 && code.meth.getKind() != javax.lang.model.element.ElementKind.STATIC_INIT)
1795 return;
1797 for (Attribute.TypeCompound ta : meth.owner.getRawTypeAttributes()) {
1798 if (ta.position.pos == treePos) {
1799 ta.position.offset = code.cp;
1800 ta.position.lvarOffset = new int[] { code.cp };
1801 ta.position.isValidOffset = true;
1802 }
1803 }
1805 ClassSymbol clazz = meth.enclClass();
1806 for (Symbol s : new com.sun.tools.javac.model.FilteredMemberList(clazz.members())) {
1807 if (!s.getKind().isField())
1808 continue;
1809 for (Attribute.TypeCompound ta : s.getRawTypeAttributes()) {
1810 if (ta.position.pos == treePos) {
1811 ta.position.offset = code.cp;
1812 ta.position.lvarOffset = new int[] { code.cp };
1813 ta.position.isValidOffset = true;
1814 }
1815 }
1816 }
1817 }
1819 public void visitNewClass(JCNewClass tree) {
1820 // Enclosing instances or anonymous classes should have been eliminated
1821 // by now.
1822 Assert.check(tree.encl == null && tree.def == null);
1823 setTypeAnnotationPositions(tree.pos);
1825 code.emitop2(new_, makeRef(tree.pos(), tree.type));
1826 code.emitop0(dup);
1828 // Generate code for all arguments, where the expected types are
1829 // the parameters of the constructor's external type (that is,
1830 // any implicit outer instance appears as first parameter).
1831 genArgs(tree.args, tree.constructor.externalType(types).getParameterTypes());
1833 items.makeMemberItem(tree.constructor, true).invoke();
1834 result = items.makeStackItem(tree.type);
1835 }
1837 public void visitNewArray(JCNewArray tree) {
1838 setTypeAnnotationPositions(tree.pos);
1840 if (tree.elems != null) {
1841 Type elemtype = types.elemtype(tree.type);
1842 loadIntConst(tree.elems.length());
1843 Item arr = makeNewArray(tree.pos(), tree.type, 1);
1844 int i = 0;
1845 for (List<JCExpression> l = tree.elems; l.nonEmpty(); l = l.tail) {
1846 arr.duplicate();
1847 loadIntConst(i);
1848 i++;
1849 genExpr(l.head, elemtype).load();
1850 items.makeIndexedItem(elemtype).store();
1851 }
1852 result = arr;
1853 } else {
1854 for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
1855 genExpr(l.head, syms.intType).load();
1856 }
1857 result = makeNewArray(tree.pos(), tree.type, tree.dims.length());
1858 }
1859 }
1860 //where
1861 /** Generate code to create an array with given element type and number
1862 * of dimensions.
1863 */
1864 Item makeNewArray(DiagnosticPosition pos, Type type, int ndims) {
1865 Type elemtype = types.elemtype(type);
1866 if (types.dimensions(type) > ClassFile.MAX_DIMENSIONS) {
1867 log.error(pos, "limit.dimensions");
1868 nerrs++;
1869 }
1870 int elemcode = Code.arraycode(elemtype);
1871 if (elemcode == 0 || (elemcode == 1 && ndims == 1)) {
1872 code.emitAnewarray(makeRef(pos, elemtype), type);
1873 } else if (elemcode == 1) {
1874 code.emitMultianewarray(ndims, makeRef(pos, type), type);
1875 } else {
1876 code.emitNewarray(elemcode, type);
1877 }
1878 return items.makeStackItem(type);
1879 }
1881 public void visitParens(JCParens tree) {
1882 result = genExpr(tree.expr, tree.expr.type);
1883 }
1885 public void visitAssign(JCAssign tree) {
1886 Item l = genExpr(tree.lhs, tree.lhs.type);
1887 genExpr(tree.rhs, tree.lhs.type).load();
1888 result = items.makeAssignItem(l);
1889 }
1891 public void visitAssignop(JCAssignOp tree) {
1892 OperatorSymbol operator = (OperatorSymbol) tree.operator;
1893 Item l;
1894 if (operator.opcode == string_add) {
1895 // Generate code to make a string buffer
1896 makeStringBuffer(tree.pos());
1898 // Generate code for first string, possibly save one
1899 // copy under buffer
1900 l = genExpr(tree.lhs, tree.lhs.type);
1901 if (l.width() > 0) {
1902 code.emitop0(dup_x1 + 3 * (l.width() - 1));
1903 }
1905 // Load first string and append to buffer.
1906 l.load();
1907 appendString(tree.lhs);
1909 // Append all other strings to buffer.
1910 appendStrings(tree.rhs);
1912 // Convert buffer to string.
1913 bufferToString(tree.pos());
1914 } else {
1915 // Generate code for first expression
1916 l = genExpr(tree.lhs, tree.lhs.type);
1918 // If we have an increment of -32768 to +32767 of a local
1919 // int variable we can use an incr instruction instead of
1920 // proceeding further.
1921 if ((tree.hasTag(PLUS_ASG) || tree.hasTag(MINUS_ASG)) &&
1922 l instanceof LocalItem &&
1923 tree.lhs.type.getTag().isSubRangeOf(INT) &&
1924 tree.rhs.type.getTag().isSubRangeOf(INT) &&
1925 tree.rhs.type.constValue() != null) {
1926 int ival = ((Number) tree.rhs.type.constValue()).intValue();
1927 if (tree.hasTag(MINUS_ASG)) ival = -ival;
1928 ((LocalItem)l).incr(ival);
1929 result = l;
1930 return;
1931 }
1932 // Otherwise, duplicate expression, load one copy
1933 // and complete binary operation.
1934 l.duplicate();
1935 l.coerce(operator.type.getParameterTypes().head).load();
1936 completeBinop(tree.lhs, tree.rhs, operator).coerce(tree.lhs.type);
1937 }
1938 result = items.makeAssignItem(l);
1939 }
1941 public void visitUnary(JCUnary tree) {
1942 OperatorSymbol operator = (OperatorSymbol)tree.operator;
1943 if (tree.hasTag(NOT)) {
1944 CondItem od = genCond(tree.arg, false);
1945 result = od.negate();
1946 } else {
1947 Item od = genExpr(tree.arg, operator.type.getParameterTypes().head);
1948 switch (tree.getTag()) {
1949 case POS:
1950 result = od.load();
1951 break;
1952 case NEG:
1953 result = od.load();
1954 code.emitop0(operator.opcode);
1955 break;
1956 case COMPL:
1957 result = od.load();
1958 emitMinusOne(od.typecode);
1959 code.emitop0(operator.opcode);
1960 break;
1961 case PREINC: case PREDEC:
1962 od.duplicate();
1963 if (od instanceof LocalItem &&
1964 (operator.opcode == iadd || operator.opcode == isub)) {
1965 ((LocalItem)od).incr(tree.hasTag(PREINC) ? 1 : -1);
1966 result = od;
1967 } else {
1968 od.load();
1969 code.emitop0(one(od.typecode));
1970 code.emitop0(operator.opcode);
1971 // Perform narrowing primitive conversion if byte,
1972 // char, or short. Fix for 4304655.
1973 if (od.typecode != INTcode &&
1974 Code.truncate(od.typecode) == INTcode)
1975 code.emitop0(int2byte + od.typecode - BYTEcode);
1976 result = items.makeAssignItem(od);
1977 }
1978 break;
1979 case POSTINC: case POSTDEC:
1980 od.duplicate();
1981 if (od instanceof LocalItem &&
1982 (operator.opcode == iadd || operator.opcode == isub)) {
1983 Item res = od.load();
1984 ((LocalItem)od).incr(tree.hasTag(POSTINC) ? 1 : -1);
1985 result = res;
1986 } else {
1987 Item res = od.load();
1988 od.stash(od.typecode);
1989 code.emitop0(one(od.typecode));
1990 code.emitop0(operator.opcode);
1991 // Perform narrowing primitive conversion if byte,
1992 // char, or short. Fix for 4304655.
1993 if (od.typecode != INTcode &&
1994 Code.truncate(od.typecode) == INTcode)
1995 code.emitop0(int2byte + od.typecode - BYTEcode);
1996 od.store();
1997 result = res;
1998 }
1999 break;
2000 case NULLCHK:
2001 result = od.load();
2002 code.emitop0(dup);
2003 genNullCheck(tree.pos());
2004 break;
2005 default:
2006 Assert.error();
2007 }
2008 }
2009 }
2011 /** Generate a null check from the object value at stack top. */
2012 private void genNullCheck(DiagnosticPosition pos) {
2013 callMethod(pos, syms.objectType, names.getClass,
2014 List.<Type>nil(), false);
2015 code.emitop0(pop);
2016 }
2018 public void visitBinary(JCBinary tree) {
2019 OperatorSymbol operator = (OperatorSymbol)tree.operator;
2020 if (operator.opcode == string_add) {
2021 // Create a string buffer.
2022 makeStringBuffer(tree.pos());
2023 // Append all strings to buffer.
2024 appendStrings(tree);
2025 // Convert buffer to string.
2026 bufferToString(tree.pos());
2027 result = items.makeStackItem(syms.stringType);
2028 } else if (tree.hasTag(AND)) {
2029 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2030 if (!lcond.isFalse()) {
2031 Chain falseJumps = lcond.jumpFalse();
2032 code.resolve(lcond.trueJumps);
2033 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2034 result = items.
2035 makeCondItem(rcond.opcode,
2036 rcond.trueJumps,
2037 Code.mergeChains(falseJumps,
2038 rcond.falseJumps));
2039 } else {
2040 result = lcond;
2041 }
2042 } else if (tree.hasTag(OR)) {
2043 CondItem lcond = genCond(tree.lhs, CRT_FLOW_CONTROLLER);
2044 if (!lcond.isTrue()) {
2045 Chain trueJumps = lcond.jumpTrue();
2046 code.resolve(lcond.falseJumps);
2047 CondItem rcond = genCond(tree.rhs, CRT_FLOW_TARGET);
2048 result = items.
2049 makeCondItem(rcond.opcode,
2050 Code.mergeChains(trueJumps, rcond.trueJumps),
2051 rcond.falseJumps);
2052 } else {
2053 result = lcond;
2054 }
2055 } else {
2056 Item od = genExpr(tree.lhs, operator.type.getParameterTypes().head);
2057 od.load();
2058 result = completeBinop(tree.lhs, tree.rhs, operator);
2059 }
2060 }
2061 //where
2062 /** Make a new string buffer.
2063 */
2064 void makeStringBuffer(DiagnosticPosition pos) {
2065 code.emitop2(new_, makeRef(pos, stringBufferType));
2066 code.emitop0(dup);
2067 callMethod(
2068 pos, stringBufferType, names.init, List.<Type>nil(), false);
2069 }
2071 /** Append value (on tos) to string buffer (on tos - 1).
2072 */
2073 void appendString(JCTree tree) {
2074 Type t = tree.type.baseType();
2075 if (!t.isPrimitive() && t.tsym != syms.stringType.tsym) {
2076 t = syms.objectType;
2077 }
2078 items.makeMemberItem(getStringBufferAppend(tree, t), false).invoke();
2079 }
2080 Symbol getStringBufferAppend(JCTree tree, Type t) {
2081 Assert.checkNull(t.constValue());
2082 Symbol method = stringBufferAppend.get(t);
2083 if (method == null) {
2084 method = rs.resolveInternalMethod(tree.pos(),
2085 attrEnv,
2086 stringBufferType,
2087 names.append,
2088 List.of(t),
2089 null);
2090 stringBufferAppend.put(t, method);
2091 }
2092 return method;
2093 }
2095 /** Add all strings in tree to string buffer.
2096 */
2097 void appendStrings(JCTree tree) {
2098 tree = TreeInfo.skipParens(tree);
2099 if (tree.hasTag(PLUS) && tree.type.constValue() == null) {
2100 JCBinary op = (JCBinary) tree;
2101 if (op.operator.kind == MTH &&
2102 ((OperatorSymbol) op.operator).opcode == string_add) {
2103 appendStrings(op.lhs);
2104 appendStrings(op.rhs);
2105 return;
2106 }
2107 }
2108 genExpr(tree, tree.type).load();
2109 appendString(tree);
2110 }
2112 /** Convert string buffer on tos to string.
2113 */
2114 void bufferToString(DiagnosticPosition pos) {
2115 callMethod(
2116 pos,
2117 stringBufferType,
2118 names.toString,
2119 List.<Type>nil(),
2120 false);
2121 }
2123 /** Complete generating code for operation, with left operand
2124 * already on stack.
2125 * @param lhs The tree representing the left operand.
2126 * @param rhs The tree representing the right operand.
2127 * @param operator The operator symbol.
2128 */
2129 Item completeBinop(JCTree lhs, JCTree rhs, OperatorSymbol operator) {
2130 MethodType optype = (MethodType)operator.type;
2131 int opcode = operator.opcode;
2132 if (opcode >= if_icmpeq && opcode <= if_icmple &&
2133 rhs.type.constValue() instanceof Number &&
2134 ((Number) rhs.type.constValue()).intValue() == 0) {
2135 opcode = opcode + (ifeq - if_icmpeq);
2136 } else if (opcode >= if_acmpeq && opcode <= if_acmpne &&
2137 TreeInfo.isNull(rhs)) {
2138 opcode = opcode + (if_acmp_null - if_acmpeq);
2139 } else {
2140 // The expected type of the right operand is
2141 // the second parameter type of the operator, except for
2142 // shifts with long shiftcount, where we convert the opcode
2143 // to a short shift and the expected type to int.
2144 Type rtype = operator.erasure(types).getParameterTypes().tail.head;
2145 if (opcode >= ishll && opcode <= lushrl) {
2146 opcode = opcode + (ishl - ishll);
2147 rtype = syms.intType;
2148 }
2149 // Generate code for right operand and load.
2150 genExpr(rhs, rtype).load();
2151 // If there are two consecutive opcode instructions,
2152 // emit the first now.
2153 if (opcode >= (1 << preShift)) {
2154 code.emitop0(opcode >> preShift);
2155 opcode = opcode & 0xFF;
2156 }
2157 }
2158 if (opcode >= ifeq && opcode <= if_acmpne ||
2159 opcode == if_acmp_null || opcode == if_acmp_nonnull) {
2160 return items.makeCondItem(opcode);
2161 } else {
2162 code.emitop0(opcode);
2163 return items.makeStackItem(optype.restype);
2164 }
2165 }
2167 public void visitTypeCast(JCTypeCast tree) {
2168 setTypeAnnotationPositions(tree.pos);
2169 result = genExpr(tree.expr, tree.clazz.type).load();
2170 // Additional code is only needed if we cast to a reference type
2171 // which is not statically a supertype of the expression's type.
2172 // For basic types, the coerce(...) in genExpr(...) will do
2173 // the conversion.
2174 if (!tree.clazz.type.isPrimitive() &&
2175 types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
2176 code.emitop2(checkcast, makeRef(tree.pos(), tree.clazz.type));
2177 }
2178 }
2180 public void visitWildcard(JCWildcard tree) {
2181 throw new AssertionError(this.getClass().getName());
2182 }
2184 public void visitTypeTest(JCInstanceOf tree) {
2185 setTypeAnnotationPositions(tree.pos);
2186 genExpr(tree.expr, tree.expr.type).load();
2187 code.emitop2(instanceof_, makeRef(tree.pos(), tree.clazz.type));
2188 result = items.makeStackItem(syms.booleanType);
2189 }
2191 public void visitIndexed(JCArrayAccess tree) {
2192 genExpr(tree.indexed, tree.indexed.type).load();
2193 genExpr(tree.index, syms.intType).load();
2194 result = items.makeIndexedItem(tree.type);
2195 }
2197 public void visitIdent(JCIdent tree) {
2198 Symbol sym = tree.sym;
2199 if (tree.name == names._this || tree.name == names._super) {
2200 Item res = tree.name == names._this
2201 ? items.makeThisItem()
2202 : items.makeSuperItem();
2203 if (sym.kind == MTH) {
2204 // Generate code to address the constructor.
2205 res.load();
2206 res = items.makeMemberItem(sym, true);
2207 }
2208 result = res;
2209 } else if (sym.kind == VAR && sym.owner.kind == MTH) {
2210 result = items.makeLocalItem((VarSymbol)sym);
2211 } else if (isInvokeDynamic(sym)) {
2212 result = items.makeDynamicItem(sym);
2213 } else if ((sym.flags() & STATIC) != 0) {
2214 if (!isAccessSuper(env.enclMethod))
2215 sym = binaryQualifier(sym, env.enclClass.type);
2216 result = items.makeStaticItem(sym);
2217 } else {
2218 items.makeThisItem().load();
2219 sym = binaryQualifier(sym, env.enclClass.type);
2220 result = items.makeMemberItem(sym, (sym.flags() & PRIVATE) != 0);
2221 }
2222 }
2224 public void visitSelect(JCFieldAccess tree) {
2225 Symbol sym = tree.sym;
2227 if (tree.name == names._class) {
2228 Assert.check(target.hasClassLiterals());
2229 code.emitop2(ldc2, makeRef(tree.pos(), tree.selected.type));
2230 result = items.makeStackItem(pt);
2231 return;
2232 }
2234 Symbol ssym = TreeInfo.symbol(tree.selected);
2236 // Are we selecting via super?
2237 boolean selectSuper =
2238 ssym != null && (ssym.kind == TYP || ssym.name == names._super);
2240 // Are we accessing a member of the superclass in an access method
2241 // resulting from a qualified super?
2242 boolean accessSuper = isAccessSuper(env.enclMethod);
2244 Item base = (selectSuper)
2245 ? items.makeSuperItem()
2246 : genExpr(tree.selected, tree.selected.type);
2248 if (sym.kind == VAR && ((VarSymbol) sym).getConstValue() != null) {
2249 // We are seeing a variable that is constant but its selecting
2250 // expression is not.
2251 if ((sym.flags() & STATIC) != 0) {
2252 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2253 base = base.load();
2254 base.drop();
2255 } else {
2256 base.load();
2257 genNullCheck(tree.selected.pos());
2258 }
2259 result = items.
2260 makeImmediateItem(sym.type, ((VarSymbol) sym).getConstValue());
2261 } else {
2262 if (isInvokeDynamic(sym)) {
2263 result = items.makeDynamicItem(sym);
2264 return;
2265 } else if (!accessSuper) {
2266 sym = binaryQualifier(sym, tree.selected.type);
2267 }
2268 if ((sym.flags() & STATIC) != 0) {
2269 if (!selectSuper && (ssym == null || ssym.kind != TYP))
2270 base = base.load();
2271 base.drop();
2272 result = items.makeStaticItem(sym);
2273 } else {
2274 base.load();
2275 if (sym == syms.lengthVar) {
2276 code.emitop0(arraylength);
2277 result = items.makeStackItem(syms.intType);
2278 } else {
2279 result = items.
2280 makeMemberItem(sym,
2281 (sym.flags() & PRIVATE) != 0 ||
2282 selectSuper || accessSuper);
2283 }
2284 }
2285 }
2286 }
2288 public boolean isInvokeDynamic(Symbol sym) {
2289 return sym.kind == MTH && ((MethodSymbol)sym).isDynamic();
2290 }
2292 public void visitLiteral(JCLiteral tree) {
2293 if (tree.type.hasTag(BOT)) {
2294 code.emitop0(aconst_null);
2295 if (types.dimensions(pt) > 1) {
2296 code.emitop2(checkcast, makeRef(tree.pos(), pt));
2297 result = items.makeStackItem(pt);
2298 } else {
2299 result = items.makeStackItem(tree.type);
2300 }
2301 }
2302 else
2303 result = items.makeImmediateItem(tree.type, tree.value);
2304 }
2306 public void visitLetExpr(LetExpr tree) {
2307 int limit = code.nextreg;
2308 genStats(tree.defs, env);
2309 result = genExpr(tree.expr, tree.expr.type).load();
2310 code.endScopes(limit);
2311 }
2313 private void generateReferencesToPrunedTree(ClassSymbol classSymbol, Pool pool) {
2314 List<JCTree> prunedInfo = lower.prunedTree.get(classSymbol);
2315 if (prunedInfo != null) {
2316 for (JCTree prunedTree: prunedInfo) {
2317 prunedTree.accept(classReferenceVisitor);
2318 }
2319 }
2320 }
2322 /* ************************************************************************
2323 * main method
2324 *************************************************************************/
2326 /** Generate code for a class definition.
2327 * @param env The attribution environment that belongs to the
2328 * outermost class containing this class definition.
2329 * We need this for resolving some additional symbols.
2330 * @param cdef The tree representing the class definition.
2331 * @return True if code is generated with no errors.
2332 */
2333 public boolean genClass(Env<AttrContext> env, JCClassDecl cdef) {
2334 try {
2335 attrEnv = env;
2336 ClassSymbol c = cdef.sym;
2337 this.toplevel = env.toplevel;
2338 this.endPosTable = toplevel.endPositions;
2339 // If this is a class definition requiring Miranda methods,
2340 // add them.
2341 if (generateIproxies &&
2342 (c.flags() & (INTERFACE|ABSTRACT)) == ABSTRACT
2343 && !allowGenerics // no Miranda methods available with generics
2344 )
2345 implementInterfaceMethods(c);
2346 cdef.defs = normalizeDefs(cdef.defs, c);
2347 c.pool = pool;
2348 pool.reset();
2349 generateReferencesToPrunedTree(c, pool);
2350 Env<GenContext> localEnv =
2351 new Env<GenContext>(cdef, new GenContext());
2352 localEnv.toplevel = env.toplevel;
2353 localEnv.enclClass = cdef;
2354 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2355 genDef(l.head, localEnv);
2356 }
2357 if (pool.numEntries() > Pool.MAX_ENTRIES) {
2358 log.error(cdef.pos(), "limit.pool");
2359 nerrs++;
2360 }
2361 if (nerrs != 0) {
2362 // if errors, discard code
2363 for (List<JCTree> l = cdef.defs; l.nonEmpty(); l = l.tail) {
2364 if (l.head.hasTag(METHODDEF))
2365 ((JCMethodDecl) l.head).sym.code = null;
2366 }
2367 }
2368 cdef.defs = List.nil(); // discard trees
2369 return nerrs == 0;
2370 } finally {
2371 // note: this method does NOT support recursion.
2372 attrEnv = null;
2373 this.env = null;
2374 toplevel = null;
2375 endPosTable = null;
2376 nerrs = 0;
2377 }
2378 }
2380 /* ************************************************************************
2381 * Auxiliary classes
2382 *************************************************************************/
2384 /** An abstract class for finalizer generation.
2385 */
2386 abstract class GenFinalizer {
2387 /** Generate code to clean up when unwinding. */
2388 abstract void gen();
2390 /** Generate code to clean up at last. */
2391 abstract void genLast();
2393 /** Does this finalizer have some nontrivial cleanup to perform? */
2394 boolean hasFinalizer() { return true; }
2395 }
2397 /** code generation contexts,
2398 * to be used as type parameter for environments.
2399 */
2400 static class GenContext {
2402 /** A chain for all unresolved jumps that exit the current environment.
2403 */
2404 Chain exit = null;
2406 /** A chain for all unresolved jumps that continue in the
2407 * current environment.
2408 */
2409 Chain cont = null;
2411 /** A closure that generates the finalizer of the current environment.
2412 * Only set for Synchronized and Try contexts.
2413 */
2414 GenFinalizer finalize = null;
2416 /** Is this a switch statement? If so, allocate registers
2417 * even when the variable declaration is unreachable.
2418 */
2419 boolean isSwitch = false;
2421 /** A list buffer containing all gaps in the finalizer range,
2422 * where a catch all exception should not apply.
2423 */
2424 ListBuffer<Integer> gaps = null;
2426 /** Add given chain to exit chain.
2427 */
2428 void addExit(Chain c) {
2429 exit = Code.mergeChains(c, exit);
2430 }
2432 /** Add given chain to cont chain.
2433 */
2434 void addCont(Chain c) {
2435 cont = Code.mergeChains(c, cont);
2436 }
2437 }
2438 }