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1   /*
2    * Copyright (c) 1994, 2003, 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   */
25  
26  package sun.tools.tree;
27  
28  import sun.tools.java.*;
29  import sun.tools.asm.Assembler;
30  import java.io.PrintStream;
31  import java.util.Hashtable;
32  
33  /**
34   * WARNING: The contents of this source file are not part of any
35   * supported API.  Code that depends on them does so at its own risk:
36   * they are subject to change or removal without notice.
37   */
38  public
39  class MethodExpression extends NaryExpression {
40      Identifier id;
41      ClassDefinition clazz;   // The class in which the called method is defined
42      MemberDefinition field;
43      Expression implementation;
44  
45      private boolean isSuper;  // Set if qualified by 'super' or '<class>.super'.
46  
47      /**
48       * constructor
49       */
50      public MethodExpression(long where, Expression right, Identifier id, Expression args[]) {
51          super(METHOD, where, Type.tError, right, args);
52          this.id = id;
53      }
54      public MethodExpression(long where, Expression right, MemberDefinition field, Expression args[]) {
55          super(METHOD, where, field.getType().getReturnType(), right, args);
56          this.id = field.getName();
57          this.field = field;
58          this.clazz = field.getClassDefinition();
59      }
60  
61      // This is a hack used only within certain access methods generated by
62      // 'SourceClass.getAccessMember'.  It allows an 'invokespecial' instruction
63      // to be forced even though 'super' does not appear within the call.
64      // Such access methods are needed for access to protected methods when using
65      // the qualified '<class>.super.<method>(...)' notation.
66      public MethodExpression(long where, Expression right,
67                              MemberDefinition field, Expression args[], boolean forceSuper) {
68          this(where, right, field, args);
69          this.isSuper = forceSuper;
70      }
71  
72      public Expression getImplementation() {
73          if (implementation != null)
74              return implementation;
75          return this;
76      }
77  
78      /**
79       * Check expression type
80       */
81      public Vset checkValue(Environment env, Context ctx, Vset vset, Hashtable exp) {
82          ClassDeclaration c = null;
83          boolean isArray = false;
84          boolean staticRef = false;
85  
86          // Access method to use if required.
87          MemberDefinition implMethod = null;
88  
89          ClassDefinition ctxClass = ctx.field.getClassDefinition();
90  
91          // When calling a constructor, we may need to add an
92          // additional argument to transmit the outer instance link.
93          Expression args[] = this.args;
94          if (id.equals(idInit)){
95              ClassDefinition conCls = ctxClass;
96              try {
97                  Expression conOuter = null;
98                  if (right instanceof SuperExpression) {
99                      // outer.super(...)
100                     conCls = conCls.getSuperClass().getClassDefinition(env);
101                     conOuter = ((SuperExpression)right).outerArg;
102                 } else if (right instanceof ThisExpression) {
103                     // outer.this(...)
104                     conOuter = ((ThisExpression)right).outerArg;
105                 }
106                 args = NewInstanceExpression.
107                     insertOuterLink(env, ctx, where, conCls, conOuter, args);
108             } catch (ClassNotFound ee) {
109                 // the same error is handled elsewhere
110             }
111         }
112 
113         Type argTypes[] = new Type[args.length];
114 
115         // The effective accessing class, for access checking.
116         // This is normally the immediately enclosing class.
117         ClassDefinition sourceClass = ctxClass;
118 
119         try {
120             if (right == null) {
121                 staticRef = ctx.field.isStatic();
122                 // Find the first outer scope that mentions the method.
123                 ClassDefinition cdef = ctxClass;
124                 MemberDefinition m = null;
125                 for (; cdef != null; cdef = cdef.getOuterClass()) {
126                     m = cdef.findAnyMethod(env, id);
127                     if (m != null) {
128                         break;
129                     }
130                 }
131                 if (m == null) {
132                     // this is the scope for error diagnosis
133                     c = ctx.field.getClassDeclaration();
134                 } else {
135                     // found the innermost scope in which m occurs
136                     c = cdef.getClassDeclaration();
137 
138                     // Maybe an inherited method hides an apparent method.
139                     // Keep looking at enclosing scopes to find out.
140                     if (m.getClassDefinition() != cdef) {
141                         ClassDefinition cdef2 = cdef;
142                         while ((cdef2 = cdef2.getOuterClass()) != null) {
143                             MemberDefinition m2 = cdef2.findAnyMethod(env, id);
144                             if (m2 != null && m2.getClassDefinition() == cdef2) {
145                                 env.error(where, "inherited.hides.method",
146                                           id, cdef.getClassDeclaration(),
147                                           cdef2.getClassDeclaration());
148                                 break;
149                             }
150                         }
151                     }
152                 }
153             } else {
154                 if (id.equals(idInit)) {
155                     int thisN = ctx.getThisNumber();
156                     if (!ctx.field.isConstructor()) {
157                         env.error(where, "invalid.constr.invoke");
158                         return vset.addVar(thisN);
159                     }
160                     // As a consequence of the DA/DU rules in the JLS (draft of
161                     // forthcoming 2e), all variables are both definitely assigned
162                     // and definitely unassigned in unreachable code.  Normally, this
163                     // correctly suppresses DA/DU-related errors in such code.
164                     // The use of the DA status of the 'this' variable for the extra
165                     // check below on correct constructor usage, however, does not quite
166                     // fit into this DA/DU scheme.  The current representation of
167                     // Vsets for unreachable dead-ends, does not allow 'clearVar'
168                     // to work, as the DA/DU bits (all on) are implicitly represented
169                     // by the fact that the Vset is a dead-end.  The DA/DU status
170                     // of the 'this' variable is supposed to be temporarily
171                     // cleared at the beginning of a constructor and during the
172                     // checking of constructor arguments (see below in this method).
173                     // Since 'clearVar' has no effect on dead-ends, we may
174                     // find the 'this' variable in an erroneously definitely-assigned state.
175                     // As a workaround, we suppress the following error message when
176                     // the Vset is a dead-end, i.e., when we are in unreachable code.
177                     // Unfortunately, the special-case treatment of reachability for
178                     // if-then and if-then-else allows unreachable code in some circumstances,
179                     // thus it is possible that no error message will be emitted at all.
180                     // While this behavior is strictly incorrect (thus we call this a
181                     // workaround), the problematic code is indeed unreachable and will
182                     // not be executed.  In fact, it will be entirely omitted from the
183                     // translated program, and can cause no harm at runtime.  A correct
184                     // solution would require modifying the representation of the DA/DU
185                     // analysis to use finite Vsets only, restricting the universe
186                     // of variables about which assertions are made (even in unreachable
187                     // code) to variables that are actually in scope. Alternatively, the
188                     // Vset extension and the dead-end marker (currently a reserved value
189                     // of the extension) could be represented orthogonally.  In either case,
190                     // 'clearVar' could then be made to work on (non-canonical) dead ends.
191                     // See file 'Vset.java'.
192                     if (!vset.isReallyDeadEnd() && vset.testVar(thisN)) {
193                         env.error(where, "constr.invoke.not.first");
194                         return vset;
195                     }
196                     vset = vset.addVar(thisN);
197                     if (right instanceof SuperExpression) {
198                         // supers require this specific kind of checking
199                         vset = right.checkAmbigName(env, ctx, vset, exp, this);
200                     } else {
201                         vset = right.checkValue(env, ctx, vset, exp);
202                     }
203                 } else {
204                     vset = right.checkAmbigName(env, ctx, vset, exp, this);
205                     if (right.type == Type.tPackage) {
206                         FieldExpression.reportFailedPackagePrefix(env, right);
207                         return vset;
208                     }
209                     if (right instanceof TypeExpression) {
210                         staticRef = true;
211                     }
212                 }
213                 if (right.type.isType(TC_CLASS)) {
214                     c = env.getClassDeclaration(right.type);
215                 } else if (right.type.isType(TC_ARRAY)) {
216                     isArray = true;
217                     c = env.getClassDeclaration(Type.tObject);
218                 } else {
219                     if (!right.type.isType(TC_ERROR)) {
220                         env.error(where, "invalid.method.invoke", right.type);
221                     }
222                     return vset;
223                 }
224 
225                 // Normally, the effective accessing class is the innermost
226                 // class surrounding the current method call, but, for calls
227                 // of the form '<class>.super.<method>(...)', it is <class>.
228                 // This allows access to protected members of a superclass
229                 // from within a class nested within one of its subclasses.
230                 // Otherwise, for example, the call below to 'matchMethod'
231                 // may fail due to the rules for visibility of inaccessible
232                 // members.  For consistency, we treat qualified 'this' in
233                 // the same manner, as error diagnostics will be affected.
234                 // QUERY: Are there subtle unexplored language issues here?
235                 if (right instanceof FieldExpression) {
236                     Identifier id = ((FieldExpression)right).id;
237                     if (id == idThis) {
238                         sourceClass = ((FieldExpression)right).clazz;
239                     } else if (id == idSuper) {
240                         isSuper = true;
241                         sourceClass = ((FieldExpression)right).clazz;
242                     }
243                 } else if (right instanceof SuperExpression) {
244                     isSuper = true;
245                 }
246 
247                 // Fix for 4158650.  When we extend a protected inner
248                 // class in a different package, we may not have access
249                 // to the type of our superclass.  Allow the call to
250                 // the superclass constructor from within our constructor
251                 // Note that this check does not apply to constructor
252                 // calls in new instance expressions -- those are part
253                 // of NewInstanceExpression#check().
254                 if (id != idInit) {
255                     // Required by JLS 6.6.1.  Fixes 4143715.
256                     // (See also 4094658.)
257                     if (!FieldExpression.isTypeAccessible(where, env,
258                                                           right.type,
259                                                           sourceClass)) {
260                         ClassDeclaration cdecl =
261                             sourceClass.getClassDeclaration();
262                         if (staticRef) {
263                             env.error(where, "no.type.access",
264                                       id, right.type.toString(), cdecl);
265                         } else {
266                             env.error(where, "cant.access.member.type",
267                                       id, right.type.toString(), cdecl);
268                         }
269                     }
270                 }
271             }
272 
273             // Compose a list of argument types
274             boolean hasErrors = false;
275 
276             // "this" is not defined during argument checking
277             if (id.equals(idInit)) {
278                 vset = vset.clearVar(ctx.getThisNumber());
279             }
280 
281             for (int i = 0 ; i < args.length ; i++) {
282                 vset = args[i].checkValue(env, ctx, vset, exp);
283                 argTypes[i] = args[i].type;
284                 hasErrors = hasErrors || argTypes[i].isType(TC_ERROR);
285             }
286 
287             // "this" is defined after the constructor invocation
288             if (id.equals(idInit)) {
289                 vset = vset.addVar(ctx.getThisNumber());
290             }
291 
292             // Check if there are any type errors in the arguments
293             if (hasErrors) {
294                 return vset;
295             }
296 
297             // Get the method field, given the argument types
298             clazz = c.getClassDefinition(env);
299 
300             if (field == null) {
301 
302                 field = clazz.matchMethod(env, sourceClass, id, argTypes);
303 
304                 if (field == null) {
305                     if (id.equals(idInit)) {
306                         if (diagnoseMismatch(env, args, argTypes))
307                             return vset;
308                         String sig = clazz.getName().getName().toString();
309                         sig = Type.tMethod(Type.tError, argTypes).typeString(sig, false, false);
310                         env.error(where, "unmatched.constr", sig, c);
311                         return vset;
312                     }
313                     String sig = id.toString();
314                     sig = Type.tMethod(Type.tError, argTypes).typeString(sig, false, false);
315                     if (clazz.findAnyMethod(env, id) == null) {
316                         if (ctx.getField(env, id) != null) {
317                             env.error(where, "invalid.method", id, c);
318                         } else {
319                             env.error(where, "undef.meth", sig, c);
320                         }
321                     } else if (diagnoseMismatch(env, args, argTypes)) {
322                     } else {
323                         env.error(where, "unmatched.meth", sig, c);
324                     }
325                     return vset;
326                 }
327 
328             }
329 
330             type = field.getType().getReturnType();
331 
332             // Make sure that static references are allowed
333             if (staticRef && !field.isStatic()) {
334                 env.error(where, "no.static.meth.access",
335                           field, field.getClassDeclaration());
336                 return vset;
337             }
338 
339             if (field.isProtected()
340                 && !(right == null)
341                 && !(right instanceof SuperExpression
342                      // Extension of JLS 6.6.2 for qualified 'super'.
343                      || (right instanceof FieldExpression &&
344                          ((FieldExpression)right).id == idSuper))
345                 && !sourceClass.protectedAccess(env, field, right.type)) {
346                 env.error(where, "invalid.protected.method.use",
347                           field.getName(), field.getClassDeclaration(),
348                           right.type);
349                 return vset;
350             }
351 
352             // In <class>.super.<method>(), we cannot simply evaluate
353             // <class>.super to an object reference (as we would for
354             // <class>.super.<field>) and then perform an 'invokespecial'.
355             // An 'invokespecial' must be performed from within (a subclass of)
356             // the class in which the target method is located.
357             if (right instanceof FieldExpression &&
358                 ((FieldExpression)right).id == idSuper) {
359                 if (!field.isPrivate()) {
360                     // The private case is handled below.
361                     // Use an access method unless the effective accessing class
362                     // (the class qualifying the 'super') is the same as the
363                     // immediately enclosing class, i.e., the qualification was
364                     // unnecessary.
365                     if (sourceClass != ctxClass) {
366                         implMethod = sourceClass.getAccessMember(env, ctx, field, true);
367                     }
368                 }
369             }
370 
371             // Access method for private field if not in the same class.
372             if (implMethod == null && field.isPrivate()) {
373                 ClassDefinition cdef = field.getClassDefinition();
374                 if (cdef != ctxClass) {
375                     implMethod = cdef.getAccessMember(env, ctx, field, false);
376                 }
377             }
378 
379             // Make sure that we are not invoking an abstract method
380             if (field.isAbstract() && (right != null) && (right.op == SUPER)) {
381                 env.error(where, "invoke.abstract", field, field.getClassDeclaration());
382                 return vset;
383             }
384 
385             if (field.reportDeprecated(env)) {
386                 if (field.isConstructor()) {
387                     env.error(where, "warn.constr.is.deprecated", field);
388                 } else {
389                     env.error(where, "warn.meth.is.deprecated",
390                               field, field.getClassDefinition());
391                 }
392             }
393 
394             // Check for recursive constructor
395             if (field.isConstructor() && ctx.field.equals(field)) {
396                 env.error(where, "recursive.constr", field);
397             }
398 
399             // When a package-private class defines public or protected
400             // members, those members may sometimes be accessed from
401             // outside of the package in public subclasses.  In these
402             // cases, we need to massage the method call to refer to
403             // to an accessible subclass rather than the package-private
404             // parent class.  Part of fix for 4135692.
405 
406             // Find out if the class which contains this method
407             // call has access to the class which declares the
408             // public or protected method referent.
409             // We don't perform this translation on constructor calls.
410             if (sourceClass == ctxClass) {
411                 ClassDefinition declarer = field.getClassDefinition();
412                 if (!field.isConstructor() &&
413                     declarer.isPackagePrivate() &&
414                     !declarer.getName().getQualifier()
415                     .equals(sourceClass.getName().getQualifier())) {
416 
417                     //System.out.println("The access of member " +
418                     //             field + " declared in class " +
419                     //             declarer +
420                     //             " is not allowed by the VM from class  " +
421                     //             accessor +
422                     //             ".  Replacing with an access of class " +
423                     //             clazz);
424 
425                     // We cannot make this access at the VM level.
426                     // Construct a member which will stand for this
427                     // method in clazz and set `field' to refer to it.
428                     field =
429                         MemberDefinition.makeProxyMember(field, clazz, env);
430                 }
431             }
432 
433             sourceClass.addDependency(field.getClassDeclaration());
434             if (sourceClass != ctxClass) {
435                 ctxClass.addDependency(field.getClassDeclaration());
436             }
437 
438         } catch (ClassNotFound ee) {
439             env.error(where, "class.not.found", ee.name, ctx.field);
440             return vset;
441 
442         } catch (AmbiguousMember ee) {
443             env.error(where, "ambig.field", id, ee.field1, ee.field2);
444             return vset;
445         }
446 
447         // Make sure it is qualified
448         if ((right == null) && !field.isStatic()) {
449             right = ctx.findOuterLink(env, where, field);
450             vset = right.checkValue(env, ctx, vset, exp);
451         }
452 
453         // Cast arguments
454         argTypes = field.getType().getArgumentTypes();
455         for (int i = 0 ; i < args.length ; i++) {
456             args[i] = convert(env, ctx, argTypes[i], args[i]);
457         }
458 
459         if (field.isConstructor()) {
460             MemberDefinition m = field;
461             if (implMethod != null) {
462                 m = implMethod;
463             }
464             int nargs = args.length;
465             Expression[] newargs = args;
466             if (nargs > this.args.length) {
467                 // Argument was added above.
468                 // Maintain the model for hidden outer args in outer.super(...):
469                 Expression rightI;
470                 if (right instanceof SuperExpression) {
471                     rightI = new SuperExpression(right.where, ctx);
472                     ((SuperExpression)right).outerArg = args[0];
473                 } else if (right instanceof ThisExpression) {
474                     rightI = new ThisExpression(right.where, ctx);
475                 } else {
476                     throw new CompilerError("this.init");
477                 }
478                 if (implMethod != null) {
479                     // Need dummy argument for access method.
480                     // Dummy argument follows outer instance link.
481                     // Leave 'this.args' equal to 'newargs' but
482                     // without the outer instance link.
483                     newargs = new Expression[nargs+1];
484                     this.args = new Expression[nargs];
485                     newargs[0] = args[0]; // outer instance
486                     this.args[0] = newargs[1] = new NullExpression(where); // dummy argument
487                     for (int i = 1 ; i < nargs ; i++) {
488                         this.args[i] = newargs[i+1] = args[i];
489                     }
490                 } else {
491                     // Strip outer instance link from 'this.args'.
492                     // ASSERT(this.arg.length == nargs-1);
493                     for (int i = 1 ; i < nargs ; i++) {
494                         this.args[i-1] = args[i];
495                     }
496                 }
497                 implementation = new MethodExpression(where, rightI, m, newargs);
498                 implementation.type = type; // Is this needed?
499             } else {
500                 // No argument was added.
501                 if (implMethod != null) {
502                     // Need dummy argument for access method.
503                     // Dummy argument is first, as there is no outer instance link.
504                     newargs = new Expression[nargs+1];
505                     newargs[0] = new NullExpression(where);
506                     for (int i = 0 ; i < nargs ; i++) {
507                         newargs[i+1] = args[i];
508                     }
509                 }
510                 implementation = new MethodExpression(where, right, m, newargs);
511             }
512         } else {
513             // Have ordinary method.
514             // Argument should have been added only for a constructor.
515             if (args.length > this.args.length) {
516                 throw new CompilerError("method arg");
517             }
518             if (implMethod != null) {
519                 //System.out.println("Calling " + field + " via " + implMethod);
520                 Expression oldargs[] = this.args;
521                 if (field.isStatic()) {
522                     Expression call = new MethodExpression(where, null, implMethod, oldargs);
523                     implementation = new CommaExpression(where, right, call);
524                 } else {
525                     // Access method needs an explicit 'this' pointer.
526                     int nargs = oldargs.length;
527                     Expression newargs[] = new Expression[nargs+1];
528                     newargs[0] = right;
529                     for (int i = 0; i < nargs; i++) {
530                         newargs[i+1] = oldargs[i];
531                     }
532                     implementation = new MethodExpression(where, null, implMethod, newargs);
533                 }
534             }
535         }
536 
537         // Follow super() by variable initializations
538         if (ctx.field.isConstructor() &&
539             field.isConstructor() && (right != null) && (right.op == SUPER)) {
540             Expression e = makeVarInits(env, ctx);
541             if (e != null) {
542                 if (implementation == null)
543                     implementation = (Expression)this.clone();
544                 implementation = new CommaExpression(where, implementation, e);
545             }
546         }
547 
548         // Throw the declared exceptions.
549         ClassDeclaration exceptions[] = field.getExceptions(env);
550         if (isArray && (field.getName() == idClone) &&
551                (field.getType().getArgumentTypes().length == 0)) {
552             /* Arrays pretend that they have "public Object clone()" that doesn't
553              * throw anything, according to the language spec.
554              */
555             exceptions = new ClassDeclaration[0];
556             /* See if there's a bogus catch for it, to issue a warning. */
557             for (Context p = ctx; p != null; p = p.prev) {
558                 if (p.node != null && p.node.op == TRY) {
559                     ((TryStatement) p.node).arrayCloneWhere = where;
560                 }
561             }
562         }
563         for (int i = 0 ; i < exceptions.length ; i++) {
564             if (exp.get(exceptions[i]) == null) {
565                 exp.put(exceptions[i], this);
566             }
567         }
568 
569         // Mark all blank finals as definitely assigned following 'this(...)'.
570         // Correctness follows inductively from the requirement that all blank finals
571         // be definitely assigned at the completion of every constructor.
572         if (ctx.field.isConstructor() &&
573             field.isConstructor() && (right != null) && (right.op == THIS)) {
574             ClassDefinition cls = field.getClassDefinition();
575             for (MemberDefinition f = cls.getFirstMember() ; f != null ; f = f.getNextMember()) {
576                 if (f.isVariable() && f.isBlankFinal() && !f.isStatic()) {
577                     // Static variables should also be considered defined as well, but this
578                     // is handled in 'SourceClass.checkMembers', and we should not interfere.
579                     vset = vset.addVar(ctx.getFieldNumber(f));
580                 }
581             }
582         }
583 
584         return vset;
585     }
586 
587     /**
588      * Check void expression
589      */
590     public Vset check(Environment env, Context ctx, Vset vset, Hashtable exp) {
591         return checkValue(env, ctx, vset, exp);
592     }
593 
594     /**
595      * We're about to report a "unmatched method" error.
596      * Try to issue a better diagnostic by comparing the actual argument types
597      * with the method (or methods) available.
598      * In particular, if there is an argument which fails to match <em>any</em>
599      * method, we report a type mismatch error against that particular argument.
600      * The diagnostic will report a target type taken from one of the methods.
601      * <p>
602      * Return false if we couldn't think of anything smart to say.
603      */
604     boolean diagnoseMismatch(Environment env, Expression args[],
605                              Type argTypes[]) throws ClassNotFound {
606         Type margType[] = new Type[1];
607         boolean saidSomething = false;
608         int start = 0;
609         while (start < argTypes.length) {
610             int code = clazz.diagnoseMismatch(env, id, argTypes, start, margType);
611             String opName = (id.equals(idInit)) ? "constructor" : opNames[op];
612             if (code == -2) {
613                 env.error(where, "wrong.number.args", opName);
614                 saidSomething = true;
615             }
616             if (code < 0)  break;
617             int i = code >> 2;
618             boolean castOK = (code & 2) != 0;
619             boolean ambig = (code & 1) != 0;
620             Type targetType = margType[0];
621 
622             // At least one argument is offensive to all overloadings.
623             // targetType is one of the argument types it does not match.
624             String ttype = ""+targetType;
625 
626             // The message might be slightly misleading, if there are other
627             // argument types that also would match.  Hint at this:
628             //if (ambig)  ttype = "{"+ttype+";...}";
629 
630             if (castOK)
631                 env.error(args[i].where, "explicit.cast.needed", opName, argTypes[i], ttype);
632             else
633                 env.error(args[i].where, "incompatible.type", opName, argTypes[i], ttype);
634             saidSomething = true;
635             start = i+1;        // look for other bad arguments, too
636         }
637         return saidSomething;
638     }
639 
640     /**
641      * Inline
642      */
643     static final int MAXINLINECOST = Statement.MAXINLINECOST;
644 
645     private
646     Expression inlineMethod(Environment env, Context ctx, Statement s, boolean valNeeded) {
647         if (env.dump()) {
648             System.out.println("INLINE METHOD " + field + " in " + ctx.field);
649         }
650         LocalMember v[] = LocalMember.copyArguments(ctx, field);
651         Statement body[] = new Statement[v.length + 2];
652 
653         int n = 0;
654         if (field.isStatic()) {
655             body[0] = new ExpressionStatement(where, right);
656         } else {
657             if ((right != null) && (right.op == SUPER)) {
658                 right = new ThisExpression(right.where, ctx);
659             }
660             body[0] = new VarDeclarationStatement(where, v[n++], right);
661         }
662         for (int i = 0 ; i < args.length ; i++) {
663             body[i + 1] = new VarDeclarationStatement(where, v[n++], args[i]);
664         }
665         //System.out.print("BEFORE:"); s.print(System.out); System.out.println();
666         // Note: If !valNeeded, then all returns in the body of the method
667         // change to void returns.
668         body[body.length - 1] = (s != null) ? s.copyInline(ctx, valNeeded) : null;
669         //System.out.print("COPY:"); body[body.length - 1].print(System.out); System.out.println();
670         LocalMember.doneWithArguments(ctx, v);
671 
672         // Make sure the type matches what the return statements are returning.
673         Type type = valNeeded ? this.type : Type.tVoid;
674         Expression e = new InlineMethodExpression(where, type, field, new CompoundStatement(where, body));
675         return valNeeded ? e.inlineValue(env, ctx) : e.inline(env, ctx);
676     }
677 
678     public Expression inline(Environment env, Context ctx) {
679         if (implementation != null)
680             return implementation.inline(env, ctx);
681         try {
682             if (right != null) {
683                 right = field.isStatic() ? right.inline(env, ctx) : right.inlineValue(env, ctx);
684             }
685             for (int i = 0 ; i < args.length ; i++) {
686                 args[i] = args[i].inlineValue(env, ctx);
687             }
688 
689             // ctxClass is the current class trying to inline this method
690             ClassDefinition ctxClass = ctx.field.getClassDefinition();
691 
692             Expression e = this;
693             if (env.opt() && field.isInlineable(env, clazz.isFinal()) &&
694 
695                 // Don't inline if a qualified non-static method: the call
696                 // itself might throw NullPointerException as a side effect
697                 ((right == null) || (right.op==THIS) || field.isStatic()) &&
698 
699                 // We only allow the inlining if the current class can access
700                 // the field, the field's class, and right's declared type.
701                 ctxClass.permitInlinedAccess(env,
702                               field.getClassDeclaration()) &&
703                 ctxClass.permitInlinedAccess(env, field) &&
704                 (right==null || ctxClass.permitInlinedAccess(env,
705                               env.getClassDeclaration(right.type)))  &&
706 
707                 ((id == null) || !id.equals(idInit)) &&
708                 (!ctx.field.isInitializer()) && ctx.field.isMethod() &&
709                 (ctx.getInlineMemberContext(field) == null)) {
710                 Statement s = (Statement)field.getValue(env);
711                 if ((s == null) ||
712                     (s.costInline(MAXINLINECOST, env, ctx) < MAXINLINECOST))  {
713                     e = inlineMethod(env, ctx, s, false);
714                 }
715             }
716             return e;
717 
718         } catch (ClassNotFound e) {
719             throw new CompilerError(e);
720         }
721     }
722 
723     public Expression inlineValue(Environment env, Context ctx) {
724         if (implementation != null)
725             return implementation.inlineValue(env, ctx);
726         try {
727             if (right != null) {
728                 right = field.isStatic() ? right.inline(env, ctx) : right.inlineValue(env, ctx);
729             }
730             if (field.getName().equals(idInit)) {
731                 ClassDefinition refc = field.getClassDefinition();
732                 UplevelReference r = refc.getReferencesFrozen();
733                 if (r != null) {
734                     r.willCodeArguments(env, ctx);
735                 }
736             }
737             for (int i = 0 ; i < args.length ; i++) {
738                 args[i] = args[i].inlineValue(env, ctx);
739             }
740 
741             // ctxClass is the current class trying to inline this method
742             ClassDefinition ctxClass = ctx.field.getClassDefinition();
743 
744             if (env.opt() && field.isInlineable(env, clazz.isFinal()) &&
745 
746                 // Don't inline if a qualified non-static method: the call
747                 // itself might throw NullPointerException as a side effect
748                 ((right == null) || (right.op==THIS) || field.isStatic()) &&
749 
750                 // We only allow the inlining if the current class can access
751                 // the field, the field's class, and right's declared type.
752                 ctxClass.permitInlinedAccess(env,
753                               field.getClassDeclaration()) &&
754                 ctxClass.permitInlinedAccess(env, field) &&
755                 (right==null || ctxClass.permitInlinedAccess(env,
756                               env.getClassDeclaration(right.type)))  &&
757 
758                 (!ctx.field.isInitializer()) && ctx.field.isMethod() &&
759                 (ctx.getInlineMemberContext(field) == null)) {
760                 Statement s = (Statement)field.getValue(env);
761                 if ((s == null) ||
762                     (s.costInline(MAXINLINECOST, env, ctx) < MAXINLINECOST))  {
763                     return inlineMethod(env, ctx, s, true);
764                 }
765             }
766             return this;
767         } catch (ClassNotFound e) {
768             throw new CompilerError(e);
769         }
770     }
771 
772     public Expression copyInline(Context ctx) {
773         if (implementation != null)
774             return implementation.copyInline(ctx);
775         return super.copyInline(ctx);
776     }
777 
778     public int costInline(int thresh, Environment env, Context ctx) {
779         if (implementation != null)
780             return implementation.costInline(thresh, env, ctx);
781 
782         // for now, don't allow calls to super() to be inlined.  We may fix
783         // this later
784         if ((right != null) && (right.op == SUPER)) {
785             return thresh;
786         }
787         return super.costInline(thresh, env, ctx);
788     }
789 
790     /*
791      * Grab all instance initializer code from the class definition,
792      * and return as one bolus.  Note that we are assuming the
793      * the relevant fields have already been checked.
794      * (See the pre-pass in SourceClass.checkMembers which ensures this.)
795      */
796     private Expression makeVarInits(Environment env, Context ctx) {
797         // insert instance initializers
798         ClassDefinition clazz = ctx.field.getClassDefinition();
799         Expression e = null;
800         for (MemberDefinition f = clazz.getFirstMember() ; f != null ; f = f.getNextMember()) {
801             if ((f.isVariable() || f.isInitializer()) && !f.isStatic()) {
802                 try {
803                     f.check(env);
804                 } catch (ClassNotFound ee) {
805                     env.error(f.getWhere(), "class.not.found", ee.name,
806                               f.getClassDefinition());
807                 }
808                 Expression val = null;
809                 if (f.isUplevelValue()) {
810                     if (f != clazz.findOuterMember()) {
811                         // it's too early to accumulate these
812                         continue;
813                     }
814                     IdentifierExpression arg =
815                         new IdentifierExpression(where, f.getName());
816                     if (!arg.bind(env, ctx)) {
817                         throw new CompilerError("bind "+arg.id);
818                     }
819                     val = arg;
820                 } else if (f.isInitializer()) {
821                     Statement s = (Statement)f.getValue();
822                     val = new InlineMethodExpression(where, Type.tVoid, f, s);
823                 } else {
824                     val = (Expression)f.getValue();
825                 }
826                 // append all initializers to "e":
827                 // This section used to check for variables which were
828                 // initialized to their default values and elide such
829                 // initialization.  This is specifically disallowed by
830                 // JLS 12.5 numeral 4, which requires a textual ordering
831                 // on the execution of initializers.
832                 if ((val != null)) { //  && !val.equals(0)) {
833                     long p = f.getWhere();
834                     val = val.copyInline(ctx);
835                     Expression init = val;
836                     if (f.isVariable()) {
837                         Expression v = new ThisExpression(p, ctx);
838                     v = new FieldExpression(p, v, f);
839                     init = new AssignExpression(p, v, val);
840                     }
841                     e = (e == null) ? init : new CommaExpression(p, e, init);
842                 }
843             }
844         }
845         return e;
846     }
847 
848     /**
849      * Code
850      */
851     public void codeValue(Environment env, Context ctx, Assembler asm) {
852         if (implementation != null)
853             throw new CompilerError("codeValue");
854         int i = 0;              // argument index
855         if (field.isStatic()) {
856             if (right != null) {
857                 right.code(env, ctx, asm);
858             }
859         } else if (right == null) {
860             asm.add(where, opc_aload, new Integer(0));
861         } else if (right.op == SUPER) {
862             // 'super.<method>(...)', 'super(...)', or '<expr>.super(...)'
863             /*****
864             isSuper = true;
865             *****/
866             right.codeValue(env, ctx, asm);
867             if (idInit.equals(id)) {
868                 // 'super(...)' or '<expr>.super(...)' only
869                 ClassDefinition refc = field.getClassDefinition();
870                 UplevelReference r = refc.getReferencesFrozen();
871                 if (r != null) {
872                     // When calling a constructor for a class with
873                     // embedded uplevel references, add extra arguments.
874                     if (r.isClientOuterField()) {
875                         // the extra arguments are inserted after this one
876                         args[i++].codeValue(env, ctx, asm);
877                     }
878                     r.codeArguments(env, ctx, asm, where, field);
879                 }
880             }
881         } else {
882             right.codeValue(env, ctx, asm);
883             /*****
884             if (right.op == FIELD &&
885                 ((FieldExpression)right).id == idSuper) {
886                 // '<class>.super.<method>(...)'
887                 isSuper = true;
888             }
889             *****/
890         }
891 
892         for ( ; i < args.length ; i++) {
893             args[i].codeValue(env, ctx, asm);
894         }
895 
896         if (field.isStatic()) {
897             asm.add(where, opc_invokestatic, field);
898         } else if (field.isConstructor() || field.isPrivate() || isSuper) {
899             asm.add(where, opc_invokespecial, field);
900         } else if (field.getClassDefinition().isInterface()) {
901             asm.add(where, opc_invokeinterface, field);
902         } else {
903             asm.add(where, opc_invokevirtual, field);
904         }
905 
906         if (right != null && right.op == SUPER && idInit.equals(id)) {
907             // 'super(...)' or '<expr>.super(...)'
908             ClassDefinition refc = ctx.field.getClassDefinition();
909             UplevelReference r = refc.getReferencesFrozen();
910             if (r != null) {
911                 // After calling a superclass constructor in a class with
912                 // embedded uplevel references, initialize uplevel fields.
913                 r.codeInitialization(env, ctx, asm, where, field);
914             }
915         }
916     }
917 
918     /**
919      * Check if the first thing is a constructor invocation
920      */
921     public Expression firstConstructor() {
922         return id.equals(idInit) ? this : null;
923     }
924 
925     /**
926      * Print
927      */
928     public void print(PrintStream out) {
929         out.print("(" + opNames[op]);
930         if (right != null) {
931             out.print(" ");
932             right.print(out);
933         }
934         out.print(" " + ((id == null) ? idInit : id));
935         for (int i = 0 ; i < args.length ; i++) {
936             out.print(" ");
937             if (args[i] != null) {
938                 args[i].print(out);
939             } else {
940                 out.print("<null>");
941             }
942         }
943         out.print(")");
944         if (implementation != null) {
945             out.print("/IMPL=");
946             implementation.print(out);
947         }
948     }
949 }