aboutsummaryrefslogtreecommitdiff
path: root/gcc/config/sh/symbian.c
blob: 02b95f5970d8a426a56aba3d1f8abe2e26cde5ff (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
/* Routines for GCC for a Symbian OS targeted SH backend.
   Copyright (C) 2004 Free Software Foundation, Inc.
   Contributed by RedHat.
   Most of this code is stolen from i386/winnt.c.

   This file is part of GCC.

   GCC is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published
   by the Free Software Foundation; either version 2, or (at your
   option) any later version.

   GCC is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
   License for more details.

   You should have received a copy of the GNU General Public License
   along with GCC; see the file COPYING.  If not, write to
   the Free Software Foundation, 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "rtl.h"
#include "output.h"
#include "flags.h"
#include "tree.h"
#include "expr.h"
#include "tm_p.h"
#include "cp/cp-tree.h"	/* We need access to the OVL_... macros.  */
#include "toplev.h"

/* Select the level of debugging information to display.
   0 for no debugging.
   1 for informative messages about decisions to add attributes
   2 for verbose information about what is being done.  */
#define SYMBIAN_DEBUG 0
//#define SYMBIAN_DEBUG 1
//#define SYMBIAN_DEBUG 2

/* A unique character to encode declspec encoded objects.  */
#define SH_SYMBIAN_FLAG_CHAR "$"

/* Unique strings to prefix exported and imported objects.  */
#define DLL_IMPORT_PREFIX SH_SYMBIAN_FLAG_CHAR "i."
#define DLL_EXPORT_PREFIX SH_SYMBIAN_FLAG_CHAR "e."


/* Return the type that we should use to determine if DECL is
   imported or exported.  */

static tree
sh_symbian_associated_type (tree decl)
{
  tree t = NULL_TREE;

  if (TREE_CODE (TREE_TYPE (decl)) == METHOD_TYPE)
  /* Methods now inherit their dllimport/dllexport attributes correctly
     so there is no need to check their class.  In fact it is wrong to
     check their class since a method can remain unexported from an
     exported class.  */
    return t;

  /* Otherwise we can just take the DECL_CONTEXT as normal.  */
  if (DECL_CONTEXT (decl) && TYPE_P (DECL_CONTEXT (decl)))
    t = DECL_CONTEXT (decl);

  return t;
}

/* Return nonzero if DECL is a dllexport'd object.  */

bool
sh_symbian_dllexport_p (tree decl)
{
  tree exp;

  if (   TREE_CODE (decl) != VAR_DECL
      && TREE_CODE (decl) != FUNCTION_DECL)
    return false;

  exp = lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl));

  /* Class members get the dllexport status of their class.  */
  if (exp == NULL)
    {
      tree class = sh_symbian_associated_type (decl);

      if (class)
	exp = lookup_attribute ("dllexport", TYPE_ATTRIBUTES (class));
    }
#if SYMBIAN_DEBUG
  if (exp)
    {
      print_node_brief (stderr, "dllexport:", decl, 0);
      fprintf (stderr, "\n");
    }
  else
#if SYMBIAN_DEBUG < 2
    if (TREE_CODE (decl) != FUNCTION_DECL)
#endif
    {
      print_node_brief (stderr, "no dllexport:", decl, 0);
      fprintf (stderr, "\n");
    }
#endif
  return exp ? true : false;
}

/* Return nonzero if DECL is a dllimport'd object.  */

static bool
sh_symbian_dllimport_p (tree decl)
{
  tree imp;

  if (   TREE_CODE (decl) != VAR_DECL
      && TREE_CODE (decl) != FUNCTION_DECL)
    return false;

  imp = lookup_attribute ("dllimport", DECL_ATTRIBUTES (decl));
  if (imp)
    return true;

  /* Class members get the dllimport status of their class.  */
  imp = sh_symbian_associated_type (decl);
  if (! imp)
    return false;

  imp = lookup_attribute ("dllimport", TYPE_ATTRIBUTES (imp));
  if (!imp)
    return false;

  /* Don't mark defined functions as dllimport.  If the definition itself
     was marked with dllimport, then sh_symbian_handle_dll_attribute reports
     an error. This handles the case when the definition overrides an
     earlier declaration.  */
  if (TREE_CODE (decl) ==  FUNCTION_DECL
      && DECL_INITIAL (decl)
      && !DECL_INLINE (decl))
    {
      /* Don't warn about artificial methods.  */
      if (!DECL_ARTIFICIAL (decl))
	warning ("%H function '%D' is defined after prior declaration as dllimport: attribute ignored",
		 & DECL_SOURCE_LOCATION (decl), decl);
      return false;
    }

  /* We ignore the dllimport attribute for inline member functions.
     This differs from MSVC behavior which treats it like GNUC
     'extern inline' extension.   */
  else if (TREE_CODE (decl) == FUNCTION_DECL && DECL_INLINE (decl))
    {
      if (extra_warnings)
	warning ("%Hinline function '%D' is declared as dllimport: attribute ignored.",
		 & DECL_SOURCE_LOCATION (decl), decl);
      return false;
    }

  /*  Don't allow definitions of static data members in dllimport
      class.  Just ignore the attribute for vtable data.  */
  else if (TREE_CODE (decl) == VAR_DECL
	   && TREE_STATIC (decl)
	   && TREE_PUBLIC (decl)
	   && !DECL_EXTERNAL (decl))
    {
      if (!DECL_VIRTUAL_P (decl))
	error ("%Hdefinition of static data member '%D' of dllimport'd class.",
	       & DECL_SOURCE_LOCATION (decl), decl);
      return false;
    }

  /* Since we can't treat a pointer to a dllimport'd symbol as a
     constant address, we turn off the attribute on C++ virtual
     methods to allow creation of vtables using thunks.  Don't mark
     artificial methods either (in sh_symbian_associated_type, only
     COMDAT artificial method get import status from class context).  */
  else if (TREE_CODE (TREE_TYPE (decl)) == METHOD_TYPE
	   && (DECL_VIRTUAL_P (decl) || DECL_ARTIFICIAL (decl)))
    return false;

  return true;
}

/* Return nonzero if SYMBOL is marked as being dllexport'd.  */

bool
sh_symbian_dllexport_name_p (const char *symbol)
{
  return strncmp (DLL_EXPORT_PREFIX, symbol,
		  strlen (DLL_EXPORT_PREFIX)) == 0;
}

/* Return nonzero if SYMBOL is marked as being dllimport'd.  */


bool
sh_symbian_dllimport_name_p (const char *symbol)
{
  return strncmp (DLL_IMPORT_PREFIX, symbol,
		  strlen (DLL_IMPORT_PREFIX)) == 0;
}

/* Mark a DECL as being dllexport'd.
   Note that we override the previous setting (e.g.: dllimport).  */

static void
sh_symbian_mark_dllexport (tree decl)
{
  const char *oldname;
  char *newname;
  rtx rtlname;
  tree idp;

  rtlname = XEXP (DECL_RTL (decl), 0);

  if (GET_CODE (rtlname) == SYMBOL_REF)
    oldname = XSTR (rtlname, 0);
  else if (GET_CODE (rtlname) == MEM
	   && GET_CODE (XEXP (rtlname, 0)) == SYMBOL_REF)
    oldname = XSTR (XEXP (rtlname, 0), 0);
  else
    abort ();

  if (sh_symbian_dllimport_name_p (oldname))
    {
     /* Remove DLL_IMPORT_PREFIX.
	Note - we do not issue a warning here.  In Symbian's environment it
	is legitimate for a prototype to be marked as dllimport and the
	corresponding definition to be marked as dllexport.  The prototypes
	are in headers used everywhere and the definition is in a translation
	unit which has included the header in order to ensure argument
	correctness.  */
      oldname += strlen (DLL_IMPORT_PREFIX);
      DECL_NON_ADDR_CONST_P (decl) = 0;
    }
  else if (sh_symbian_dllexport_name_p (oldname))
    return; /* Already done.  */

  newname = alloca (strlen (DLL_EXPORT_PREFIX) + strlen (oldname) + 1);
  sprintf (newname, "%s%s", DLL_EXPORT_PREFIX, oldname);

  /* We pass newname through get_identifier to ensure it has a unique
     address.  RTL processing can sometimes peek inside the symbol ref
     and compare the string's addresses to see if two symbols are
     identical.  */
  idp = get_identifier (newname);

  XEXP (DECL_RTL (decl), 0) =
    gen_rtx_SYMBOL_REF (Pmode, IDENTIFIER_POINTER (idp));
}

/* Mark a DECL as being dllimport'd.  */

static void
sh_symbian_mark_dllimport (tree decl)
{
  const char *oldname;
  char *newname;
  tree idp;
  rtx rtlname;
  rtx newrtl;

  rtlname = XEXP (DECL_RTL (decl), 0);

  if (GET_CODE (rtlname) == SYMBOL_REF)
    oldname = XSTR (rtlname, 0);
  else if (GET_CODE (rtlname) == MEM
	   && GET_CODE (XEXP (rtlname, 0)) == SYMBOL_REF)
    oldname = XSTR (XEXP (rtlname, 0), 0);
  else
    abort ();

  if (sh_symbian_dllexport_name_p (oldname))
    {
      error ("`%s' declared as both exported to and imported from a DLL",
             IDENTIFIER_POINTER (DECL_NAME (decl)));
    }
  else if (sh_symbian_dllimport_name_p (oldname))
    {
      /* Already done, but do a sanity check to prevent assembler errors.  */
      if (!DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl))
	error ("%Hfailure in redeclaration of '%D': dllimport'd symbol lacks external linkage.",
	       &DECL_SOURCE_LOCATION (decl), decl);
    }
  else
    {
      newname = alloca (strlen (DLL_IMPORT_PREFIX) + strlen (oldname) + 1);
      sprintf (newname, "%s%s", DLL_IMPORT_PREFIX, oldname);

      /* We pass newname through get_identifier to ensure it has a unique
	 address.  RTL processing can sometimes peek inside the symbol ref
	 and compare the string's addresses to see if two symbols are
	 identical.  */
      idp = get_identifier (newname);
      newrtl = gen_rtx_SYMBOL_REF (Pmode, IDENTIFIER_POINTER (idp));
      XEXP (DECL_RTL (decl), 0) = newrtl;
    }
}

void
sh_symbian_encode_section_info (tree decl, rtx rtl, int first)
{
  default_encode_section_info (decl, rtl, first);

  /* Mark the decl so we can tell from the rtl whether
     the object is dllexport'd or dllimport'd.  */
  if (sh_symbian_dllexport_p (decl))
    sh_symbian_mark_dllexport (decl);
  else if (sh_symbian_dllimport_p (decl))
    sh_symbian_mark_dllimport (decl);
  /* It might be that DECL has already been marked as dllimport, but a
     subsequent definition nullified that.  The attribute is gone but
     DECL_RTL still has (DLL_IMPORT_PREFIX) prefixed. We need to remove
     that. Ditto for the DECL_NON_ADDR_CONST_P flag.  */
  else if (  (TREE_CODE (decl) == FUNCTION_DECL
	   || TREE_CODE (decl) == VAR_DECL)
	   && DECL_RTL (decl) != NULL_RTX
	   && GET_CODE (DECL_RTL (decl)) == MEM
	   && GET_CODE (XEXP (DECL_RTL (decl), 0)) == MEM
	   && GET_CODE (XEXP (XEXP (DECL_RTL (decl), 0), 0)) == SYMBOL_REF
	   && sh_symbian_dllimport_name_p (XSTR (XEXP (XEXP (DECL_RTL (decl), 0), 0), 0)))
    {
      const char * oldname = XSTR (XEXP (XEXP (DECL_RTL (decl), 0), 0), 0);
      /* Remove DLL_IMPORT_PREFIX.  */
      tree idp = get_identifier (oldname + strlen (DLL_IMPORT_PREFIX));
      rtx newrtl = gen_rtx_SYMBOL_REF (Pmode, IDENTIFIER_POINTER (idp));

      warning ("%H%s '%D' %s after being referenced with dllimport linkage.",
	       & DECL_SOURCE_LOCATION (decl),
	       TREE_CODE (decl) == VAR_DECL ? "variable" : "function",
	       decl, (DECL_INITIAL (decl) || !DECL_EXTERNAL (decl))
	       ? "defined locally" : "redeclared without dllimport attribute");

      XEXP (DECL_RTL (decl), 0) = newrtl;

      DECL_NON_ADDR_CONST_P (decl) = 0;
    }
}


/* Return the length of a function name prefix
    that starts with the character 'c'.  */

static int
sh_symbian_get_strip_length (int c)
{
  /* XXX Assumes strlen (DLL_EXPORT_PREFIX) == strlen (DLL_IMPORT_PREFIX).  */
  return (c == SH_SYMBIAN_FLAG_CHAR[0]) ? strlen (DLL_EXPORT_PREFIX) : 0;
}

/* Return a pointer to a function's name with any
   and all prefix encodings stripped from it.  */

const char *
sh_symbian_strip_name_encoding (const char *name)
{
  int skip;

  while ((skip = sh_symbian_get_strip_length (*name)))
    name += skip;

  return name;
}

/* Add the named attribute to the given node.  Copes with both DECLs and
   TYPEs.  Will only add the attribute if it is not already present.  */

static void
symbian_add_attribute (tree node, const char *attr_name)
{
  tree attrs;
  tree attr;

  attrs = DECL_P (node) ? DECL_ATTRIBUTES (node) : TYPE_ATTRIBUTES (node);

  if (lookup_attribute (attr_name, attrs) != NULL_TREE)
    return;

  attr = get_identifier (attr_name);

  (DECL_P (node) ? DECL_ATTRIBUTES (node) : TYPE_ATTRIBUTES (node))
    = tree_cons (attr, NULL_TREE, attrs);

#if SYMBIAN_DEBUG
  fprintf (stderr, "propogate %s attribute", attr_name);
  print_node_brief (stderr, " to", node, 0);
  fprintf (stderr, "\n");
#endif
}

/* Handle a "dllimport" or "dllexport" attribute;
   arguments as in struct attribute_spec.handler.  */

tree
sh_symbian_handle_dll_attribute (tree *pnode, tree name, tree args,
				 int flags, bool *no_add_attrs)
{
  tree thunk;
  tree node = *pnode;
  const char *attr = IDENTIFIER_POINTER (name);

  /* These attributes may apply to structure and union types being
     created, but otherwise should pass to the declaration involved.  */
  if (!DECL_P (node))
    {
      if (flags & ((int) ATTR_FLAG_DECL_NEXT
		   | (int) ATTR_FLAG_FUNCTION_NEXT
		   | (int) ATTR_FLAG_ARRAY_NEXT))
	{
	  warning ("`%s' attribute ignored", attr);
	  *no_add_attrs = true;
	  return tree_cons (name, args, NULL_TREE);
	}

      if (TREE_CODE (node) != RECORD_TYPE && TREE_CODE (node) != UNION_TYPE)
	{
	  warning ("`%s' attribute ignored", attr);
	  *no_add_attrs = true;
	}

      return NULL_TREE;
    }

  /* Report error on dllimport ambiguities
     seen now before they cause any damage.  */
  else if (is_attribute_p ("dllimport", name))
    {
      if (TREE_CODE (node) == VAR_DECL)
	{
	  if (DECL_INITIAL (node))
	    {
	      error ("%Hvariable `%D' definition is marked dllimport.",
		     & DECL_SOURCE_LOCATION (node), node);
	      *no_add_attrs = true;
	    }

	  /* `extern' needn't be specified with dllimport.
	     Specify `extern' now and hope for the best.  Sigh.  */
	  DECL_EXTERNAL (node) = 1;
	  /* Also, implicitly give dllimport'd variables declared within
	     a function global scope, unless declared static.  */
	  if (current_function_decl != NULL_TREE && ! TREE_STATIC (node))
  	    TREE_PUBLIC (node) = 1;
	}
    }

  /* If the node is an overloaded constructor or destructor, then we must
     make sure that the attribute is propagated along the overload chain,
     as it is these overloaded functions which will be emitted, rather than
     the user declared constructor itself.  */
  if (TREE_CODE (TREE_TYPE (node)) == METHOD_TYPE
      && (DECL_CONSTRUCTOR_P (node) || DECL_DESTRUCTOR_P (node)))
    {
      tree overload;

      for (overload = OVL_CHAIN (node); overload; overload = OVL_CHAIN (overload))
	{
	  tree node_args;
	  tree func_args;
	  tree function = OVL_CURRENT (overload);

	  if (! function
	      || ! DECL_P (function)
	      || (DECL_CONSTRUCTOR_P (node) && ! DECL_CONSTRUCTOR_P (function))
	      || (DECL_DESTRUCTOR_P (node)  && ! DECL_DESTRUCTOR_P (function)))
	    continue;

	  /* The arguments must match as well.  */
	  for (node_args = DECL_ARGUMENTS (node), func_args = DECL_ARGUMENTS (function);
	       node_args && func_args;
	       node_args = TREE_CHAIN (node_args), func_args = TREE_CHAIN (func_args))
	    if (TREE_TYPE (node_args) != TREE_TYPE (func_args))
	      break;

	  if (node_args || func_args)
	    {
	      /* We can ignore an extraneous __in_chrg arguments in the node.
		 GCC generated destructors, for example, will have this.  */
	      if ((node_args == NULL_TREE
		   || func_args != NULL_TREE)
		  && strcmp (IDENTIFIER_POINTER (DECL_NAME (node)), "__in_chrg") != 0)
		continue;
	    }

	  symbian_add_attribute (function, attr);

	  /* Propagate the attribute to any function thunks as well.  */
	  for (thunk = DECL_THUNKS (function); thunk; thunk = TREE_CHAIN (thunk))
	    if (TREE_CODE (thunk) == FUNCTION_DECL)
	      symbian_add_attribute (thunk, attr);
	}
    }

  if (TREE_CODE (node) == FUNCTION_DECL && DECL_VIRTUAL_P (node))
    {
      /* Propagate the attribute to any thunks of this function.  */
      for (thunk = DECL_THUNKS (node); thunk; thunk = TREE_CHAIN (thunk))
	if (TREE_CODE (thunk) == FUNCTION_DECL)
	  symbian_add_attribute (thunk, attr);
    }

  /*  Report error if symbol is not accessible at global scope.  */
  if (!TREE_PUBLIC (node)
      && (   TREE_CODE (node) == VAR_DECL
	  || TREE_CODE (node) == FUNCTION_DECL))
    {
      error ("%Hexternal linkage required for symbol '%D' because of '%s' attribute.",
	       & DECL_SOURCE_LOCATION (node), node, IDENTIFIER_POINTER (name));
      *no_add_attrs = true;
    }

#if SYMBIAN_DEBUG
  print_node_brief (stderr, "mark node", node, 0);
  fprintf (stderr, " as %s\n", attr);
#endif

  return NULL_TREE;
}

/* This code implements a specification for exporting the vtable and rtti of
   classes that have members with the dllexport or dllexport attributes.
   This specification is defined here:

     http://www.armdevzone.com/EABI/exported_class.txt

   Basically it says that a class's vtable and rtti should be exported if
   the following rules apply:

   - If it has any non-inline non-pure virtual functions,
     at least one of these need to be declared dllimport
     OR any of the constructors is declared dllimport.

   AND

   - The class has an inline constructor/destructor and
     a key-function (placement of vtable uniquely defined) that
     is defined in this translation unit.

   The specification also says that for classes which will have their
   vtables and rtti exported that their base class(es) might also need a
   similar exporting if:

   - Every base class needs to have its vtable & rtti exported
     as well, if the following the conditions hold true:
     + The base class has a non-inline declared non-pure virtual function
     + The base class is polymorphic (has or inherits any virtual functions)
       or the base class has any virtual base classes.  */

/* Decide if a base class of a class should
   also have its vtable and rtti exported.  */

static void
symbian_possibly_export_base_class (tree base_class)
{
  tree methods;
  int len;

  if (! (TYPE_CONTAINS_VPTR_P (base_class)))
    return;

  methods = CLASSTYPE_METHOD_VEC (base_class);
  len = methods ? TREE_VEC_LENGTH (methods) : 0;

  for (;len --;)
    {
      tree member = TREE_VEC_ELT (methods, len);

      if (! member)
	continue;

      for (member = OVL_CURRENT (member); member; member = OVL_NEXT (member))
	{
	  if (TREE_CODE (member) != FUNCTION_DECL)
	    continue;

	  if (DECL_CONSTRUCTOR_P (member) || DECL_DESTRUCTOR_P (member))
	    continue;

	  if (! DECL_VIRTUAL_P (member))
	    continue;

	  if (DECL_PURE_VIRTUAL_P (member))
	    continue;

	  if (DECL_INLINE (member))
	    continue;

	  break;
	}

      if (member)
	break;
    }

  if (len < 0)
    return;

  /* FIXME: According to the spec this base class should be exported, but
     a) how do we do this ? and
     b) it does not appear to be necessary for compliance with the Symbian
        OS which so far is the only consumer of this code.  */
#if SYMBIAN_DEBUG
  print_node_brief (stderr, "", base_class, 0);
  fprintf (stderr, " EXPORTed [base class of exported class]\n");
#endif
}

/* Decide if a class needs its vtable and rtti exporting.  */

static bool
symbian_export_vtable_and_rtti_p (tree ctype)
{
  bool inline_ctor_dtor;
  bool dllimport_ctor_dtor;
  bool dllimport_member;
  tree binfo, base_binfo;
  tree methods;
  tree key;
  int i;
  int len;

  /* Make sure that we are examining a class...  */
  if (TREE_CODE (ctype) != RECORD_TYPE)
    {
#if SYMBIAN_DEBUG
      print_node_brief (stderr, "", ctype, 0);
      fprintf (stderr, " does NOT need to be EXPORTed [not a class]\n");
#endif
      return false;
    }

  /* If the class does not have a key function it
     does not need to have its vtable exported.  */
  if ((key = CLASSTYPE_KEY_METHOD (ctype)) == NULL_TREE)
    {
#if SYMBIAN_DEBUG
      print_node_brief (stderr, "", ctype, 0);
      fprintf (stderr, " does NOT need to be EXPORTed [no key function]\n");
#endif
      return false;
    }

  /* If the key fn has not been defined
     then the class should not be exported.  */
  if (! TREE_ASM_WRITTEN (key))
    {
#if SYMBIAN_DEBUG
      print_node_brief (stderr, "", ctype, 0);
      fprintf (stderr, " does NOT need to be EXPORTed [key function not defined]\n");
#endif
      return false;
    }

  /* Check the class's member functions.  */
  inline_ctor_dtor = false;
  dllimport_ctor_dtor = false;
  dllimport_member = false;

  methods = CLASSTYPE_METHOD_VEC (ctype);
  len = methods ? TREE_VEC_LENGTH (methods) : 0;

  for (;len --;)
    {
      tree member = TREE_VEC_ELT (methods, len);

      if (! member)
	continue;

      for (member = OVL_CURRENT (member); member; member = OVL_NEXT (member))
	{
	  if (TREE_CODE (member) != FUNCTION_DECL)
	    continue;

	  if (DECL_CONSTRUCTOR_P (member) || DECL_DESTRUCTOR_P (member))
	    {
	      if (DECL_INLINE (member)
		  /* Ignore C++ backend created inline ctors/dtors.  */
		  && (   DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (member)
		      || DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (member)))
		inline_ctor_dtor = true;

	      if (lookup_attribute ("dllimport", DECL_ATTRIBUTES (member)))
		dllimport_ctor_dtor = true;
	    }
	  else
	    {
	      if (DECL_PURE_VIRTUAL_P (member))
		continue;

	      if (! DECL_VIRTUAL_P (member))
		continue;

	      if (DECL_INLINE (member))
		continue;

	      if (lookup_attribute ("dllimport", DECL_ATTRIBUTES (member)))
		dllimport_member = true;
	    }
	}
    }

  if (! dllimport_member && ! dllimport_ctor_dtor)
    {
#if SYMBIAN_DEBUG
      print_node_brief (stderr, "", ctype, 0);
      fprintf (stderr,
	       " does NOT need to be EXPORTed [no non-pure virtuals or ctors/dtors with dllimport]\n");
#endif
      return false;
    }

  if (! inline_ctor_dtor)
    {
#if SYMBIAN_DEBUG
      print_node_brief (stderr, "", ctype, 0);
      fprintf (stderr,
	       " does NOT need to be EXPORTed [no inline ctor/dtor]\n");
#endif
      return false;
    }

#if SYMBIAN_DEBUG
  print_node_brief (stderr, "", ctype, 0);
  fprintf (stderr, " DOES need to be EXPORTed\n");
#endif

  /* Now we must check and possibly export the base classes.  */
  for (i = 0, binfo = TYPE_BINFO (ctype);
       BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
    symbian_possibly_export_base_class (BINFO_TYPE (base_binfo));

  return true;
}

/* Add the named attribute to a class and its vtable and rtti.  */

static void
symbian_add_attribute_to_class_vtable_and_rtti (tree ctype, const char *attr_name)
{
  symbian_add_attribute (ctype, attr_name);

  /* If the vtable exists then they need annotating as well.  */
  if (CLASSTYPE_VTABLES (ctype))
    /* XXX - Do we need to annotate any vtables other than the primary ?  */
    symbian_add_attribute (CLASSTYPE_VTABLES (ctype), attr_name);

  /* If the rtti exists then it needs annotating as well.  */
  if (TYPE_MAIN_VARIANT (ctype)
      && CLASSTYPE_TYPEINFO_VAR (TYPE_MAIN_VARIANT (ctype)))
    symbian_add_attribute (CLASSTYPE_TYPEINFO_VAR (TYPE_MAIN_VARIANT (ctype)),
			   attr_name);
}

/* Decide if a class needs to have an attribute because
   one of its member functions has the attribute.  */

static bool
symbian_class_needs_attribute_p (tree ctype, const char *attribute_name)
{
  /* If the key function has the attribute then the class needs it too.  */
  if (TYPE_POLYMORPHIC_P (ctype)
      && CLASSTYPE_KEY_METHOD (ctype)
      && lookup_attribute (attribute_name,
			   DECL_ATTRIBUTES (CLASSTYPE_KEY_METHOD (ctype))))
    return true;

  /* Check the class's member functions.  */
  if (TREE_CODE (ctype) == RECORD_TYPE)
    {
      tree methods = CLASSTYPE_METHOD_VEC (ctype);
      unsigned int len = methods ? TREE_VEC_LENGTH (methods) : 0;

      for (;len --;)
	{
	  tree member = TREE_VEC_ELT (methods, len);

	  if (! member)
	    continue;

	  for (member = OVL_CURRENT (member);
	       member;
	       member = OVL_NEXT (member))
	    {
	      if (TREE_CODE (member) != FUNCTION_DECL)
		continue;

	      if (DECL_PURE_VIRTUAL_P (member))
		continue;

	      if (! DECL_VIRTUAL_P (member))
		continue;

	      if (lookup_attribute (attribute_name, DECL_ATTRIBUTES (member)))
		{
#if SYMBIAN_DEBUG
		  print_node_brief (stderr, "", ctype, 0);
		  fprintf (stderr, " inherits %s because", attribute_name);
		  print_node_brief (stderr, "", member, 0);
		  fprintf (stderr, " has it.\n");
#endif
		  return true;
		}
	    }
	}
    }

#if SYMBIAN_DEBUG
  print_node_brief (stderr, "", ctype, 0);
  fprintf (stderr, " does not inherit %s\n", attribute_name);
#endif
  return false;
}

int
symbian_import_export_class (tree ctype, int import_export)
{
  const char *attr_name = NULL;

  /* If we are exporting the class but it does not have the dllexport
     attribute then we may need to add it.  Similarly imported classes
     may need the dllimport attribute.  */
  switch (import_export)
    {
    case  1: attr_name = "dllexport"; break;
    case -1: attr_name = "dllimport"; break;
    default: break;
    }

  if (attr_name
      && ! lookup_attribute (attr_name, TYPE_ATTRIBUTES (ctype)))
    {
      if (symbian_class_needs_attribute_p (ctype, attr_name))
	symbian_add_attribute_to_class_vtable_and_rtti (ctype, attr_name);

      /* Classes can be forced to export their
	 vtable and rtti under certain conditions.  */
      if (symbian_export_vtable_and_rtti_p (ctype))
	{
	  symbian_add_attribute_to_class_vtable_and_rtti (ctype, "dllexport");

	  /* Make sure that the class and its vtable are exported.  */
	  import_export = 1;

	  if (CLASSTYPE_VTABLES (ctype))
	    DECL_EXTERNAL (CLASSTYPE_VTABLES (ctype)) = 1;

	  /* Check to make sure that if the class has a key method that
	     it is now on the list of keyed classes.  That way its vtable
	     will be emitted.  */
	  if (CLASSTYPE_KEY_METHOD (ctype))
	    {
	      tree class;

	      for (class = keyed_classes; class; class = TREE_CHAIN (class))
		if (class == ctype)
		  break;

	      if (class == NULL_TREE)
		{
#if SYMBIAN_DEBUG
		  print_node_brief (stderr, "Add node", ctype, 0);
		  fprintf (stderr, " to the keyed classes list\n");
#endif
		  keyed_classes = tree_cons (NULL_TREE, ctype, keyed_classes);
		}
	    }

	  /* Make sure that the typeinfo will be emitted as well.  */
	  if (CLASS_TYPE_P (ctype))
	    TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (CLASSTYPE_TYPEINFO_VAR (TYPE_MAIN_VARIANT (ctype)))) = 1;
	}
    }

  return import_export;
}

/* Dummy definition of this array for cc1 building purposes.  */
tree cp_global_trees[CPTI_MAX] __attribute__((weak));

#if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)

/* Dummy version of this G++ function for building cc1.  */
void lang_check_failed (const char *, int, const char *) __attribute__((weak));

void
lang_check_failed (const char *file, int line, const char *function)
{
  internal_error ("lang_* check: failed in %s, at %s:%d",
		  function, trim_filename (file), line);
}
#endif /* ENABLE_TREE_CHECKING */