summaryrefslogtreecommitdiff
path: root/libcpp/traditional.c
blob: 7ff11bb205e57ff184782b678d7c3eefaaf2a806 (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
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
/* CPP Library - traditional lexical analysis and macro expansion.
   Copyright (C) 2002, 2004, 2005, 2007, 2008, 2009
   Free Software Foundation, Inc.
   Contributed by Neil Booth, May 2002

This program 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 3, or (at your option) any
later version.

This program 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 this program; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#include "config.h"
#include "system.h"
#include "cpplib.h"
#include "internal.h"

/* The replacement text of a function-like macro is stored as a
   contiguous sequence of aligned blocks, each representing the text
   between subsequent parameters.

   Each block comprises the text between its surrounding parameters,
   the length of that text, and the one-based index of the following
   parameter.  The final block in the replacement text is easily
   recognizable as it has an argument index of zero.  */

struct block
{
  unsigned int text_len;
  unsigned short arg_index;
  uchar text[1];
};

#define BLOCK_HEADER_LEN offsetof (struct block, text)
#define BLOCK_LEN(TEXT_LEN) CPP_ALIGN (BLOCK_HEADER_LEN + (TEXT_LEN))

/* Structure holding information about a function-like macro
   invocation.  */
struct fun_macro
{
  /* Memory buffer holding the trad_arg array.  */
  _cpp_buff *buff;

  /* An array of size the number of macro parameters + 1, containing
     the offsets of the start of each macro argument in the output
     buffer.  The argument continues until the character before the
     start of the next one.  */
  size_t *args;

  /* The hashnode of the macro.  */
  cpp_hashnode *node;

  /* The offset of the macro name in the output buffer.  */
  size_t offset;

  /* The line the macro name appeared on.  */
  source_location line;

  /* Zero-based index of argument being currently lexed.  */
  unsigned int argc;
};

/* Lexing state.  It is mostly used to prevent macro expansion.  */
enum ls {ls_none = 0,		/* Normal state.  */
	 ls_fun_open,		/* When looking for '('.  */
	 ls_fun_close,		/* When looking for ')'.  */
	 ls_defined,		/* After defined.  */
	 ls_defined_close,	/* Looking for ')' of defined().  */
	 ls_hash,		/* After # in preprocessor conditional.  */
	 ls_predicate,		/* After the predicate, maybe paren?  */
	 ls_answer};		/* In answer to predicate.  */

/* Lexing TODO: Maybe handle space in escaped newlines.  Stop lex.c
   from recognizing comments and directives during its lexing pass.  */

static const uchar *skip_whitespace (cpp_reader *, const uchar *, int);
static cpp_hashnode *lex_identifier (cpp_reader *, const uchar *);
static const uchar *copy_comment (cpp_reader *, const uchar *, int);
static void check_output_buffer (cpp_reader *, size_t);
static void push_replacement_text (cpp_reader *, cpp_hashnode *);
static bool scan_parameters (cpp_reader *, cpp_macro *);
static bool recursive_macro (cpp_reader *, cpp_hashnode *);
static void save_replacement_text (cpp_reader *, cpp_macro *, unsigned int);
static void maybe_start_funlike (cpp_reader *, cpp_hashnode *, const uchar *,
				 struct fun_macro *);
static void save_argument (struct fun_macro *, size_t);
static void replace_args_and_push (cpp_reader *, struct fun_macro *);
static size_t canonicalize_text (uchar *, const uchar *, size_t, uchar *);

/* Ensures we have N bytes' space in the output buffer, and
   reallocates it if not.  */
static void
check_output_buffer (cpp_reader *pfile, size_t n)
{
  /* We might need two bytes to terminate an unterminated comment, and
     one more to terminate the line with a NUL.  */
  n += 2 + 1;

  if (n > (size_t) (pfile->out.limit - pfile->out.cur))
    {
      size_t size = pfile->out.cur - pfile->out.base;
      size_t new_size = (size + n) * 3 / 2;

      pfile->out.base = XRESIZEVEC (unsigned char, pfile->out.base, new_size);
      pfile->out.limit = pfile->out.base + new_size;
      pfile->out.cur = pfile->out.base + size;
    }
}

/* Skip a C-style block comment in a macro as a result of -CC.
   Buffer->cur points to the initial asterisk of the comment.  */
static void
skip_macro_block_comment (cpp_reader *pfile)
{
  const uchar *cur = pfile->buffer->cur;

  cur++;
  if (*cur == '/')
    cur++;

  /* People like decorating comments with '*', so check for '/'
     instead for efficiency.  */
  while(! (*cur++ == '/' && cur[-2] == '*') )
    ;

  pfile->buffer->cur = cur;
}

/* CUR points to the asterisk introducing a comment in the current
   context.  IN_DEFINE is true if we are in the replacement text of a
   macro.

   The asterisk and following comment is copied to the buffer pointed
   to by pfile->out.cur, which must be of sufficient size.
   Unterminated comments are diagnosed, and correctly terminated in
   the output.  pfile->out.cur is updated depending upon IN_DEFINE,
   -C, -CC and pfile->state.in_directive.

   Returns a pointer to the first character after the comment in the
   input buffer.  */
static const uchar *
copy_comment (cpp_reader *pfile, const uchar *cur, int in_define)
{
  bool unterminated, copy = false;
  source_location src_loc = pfile->line_table->highest_line;
  cpp_buffer *buffer = pfile->buffer;

  buffer->cur = cur;
  if (pfile->context->prev)
    unterminated = false, skip_macro_block_comment (pfile);
  else
    unterminated = _cpp_skip_block_comment (pfile);
    
  if (unterminated)
    cpp_error_with_line (pfile, CPP_DL_ERROR, src_loc, 0,
			 "unterminated comment");

  /* Comments in directives become spaces so that tokens are properly
     separated when the ISO preprocessor re-lexes the line.  The
     exception is #define.  */
  if (pfile->state.in_directive)
    {
      if (in_define)
	{
	  if (CPP_OPTION (pfile, discard_comments_in_macro_exp))
	    pfile->out.cur--;
	  else
	    copy = true;
	}
      else
	pfile->out.cur[-1] = ' ';
    }
  else if (CPP_OPTION (pfile, discard_comments))
    pfile->out.cur--;
  else
    copy = true;

  if (copy)
    {
      size_t len = (size_t) (buffer->cur - cur);
      memcpy (pfile->out.cur, cur, len);
      pfile->out.cur += len;
      if (unterminated)
	{
	  *pfile->out.cur++ = '*';
	  *pfile->out.cur++ = '/';
	}
    }

  return buffer->cur;
}

/* CUR points to any character in the input buffer.  Skips over all
   contiguous horizontal white space and NULs, including comments if
   SKIP_COMMENTS, until reaching the first non-horizontal-whitespace
   character or the end of the current context.  Escaped newlines are
   removed.

   The whitespace is copied verbatim to the output buffer, except that
   comments are handled as described in copy_comment().
   pfile->out.cur is updated.

   Returns a pointer to the first character after the whitespace in
   the input buffer.  */
static const uchar *
skip_whitespace (cpp_reader *pfile, const uchar *cur, int skip_comments)
{
  uchar *out = pfile->out.cur;

  for (;;)
    {
      unsigned int c = *cur++;
      *out++ = c;

      if (is_nvspace (c))
	continue;

      if (c == '/' && *cur == '*' && skip_comments)
	{
	  pfile->out.cur = out;
	  cur = copy_comment (pfile, cur, false /* in_define */);
	  out = pfile->out.cur;
	  continue;
	}

      out--;
      break;
    }

  pfile->out.cur = out;
  return cur - 1;
}

/* Lexes and outputs an identifier starting at CUR, which is assumed
   to point to a valid first character of an identifier.  Returns
   the hashnode, and updates out.cur.  */
static cpp_hashnode *
lex_identifier (cpp_reader *pfile, const uchar *cur)
{
  size_t len;
  uchar *out = pfile->out.cur;
  cpp_hashnode *result;

  do
    *out++ = *cur++;
  while (is_numchar (*cur));

  CUR (pfile->context) = cur;
  len = out - pfile->out.cur;
  result = CPP_HASHNODE (ht_lookup (pfile->hash_table, pfile->out.cur,
				    len, HT_ALLOC));
  pfile->out.cur = out;
  return result;
}

/* Overlays the true file buffer temporarily with text of length LEN
   starting at START.  The true buffer is restored upon calling
   restore_buff().  */
void
_cpp_overlay_buffer (cpp_reader *pfile, const uchar *start, size_t len)
{
  cpp_buffer *buffer = pfile->buffer;

  pfile->overlaid_buffer = buffer;
  pfile->saved_cur = buffer->cur;
  pfile->saved_rlimit = buffer->rlimit;
  pfile->saved_line_base = buffer->next_line;
  buffer->need_line = false;

  buffer->cur = start;
  buffer->line_base = start;
  buffer->rlimit = start + len;
}

/* Restores a buffer overlaid by _cpp_overlay_buffer().  */
void
_cpp_remove_overlay (cpp_reader *pfile)
{
  cpp_buffer *buffer = pfile->overlaid_buffer;

  buffer->cur = pfile->saved_cur;
  buffer->rlimit = pfile->saved_rlimit;
  buffer->line_base = pfile->saved_line_base;
  buffer->need_line = true;

  pfile->overlaid_buffer = NULL;
}

/* Reads a logical line into the output buffer.  Returns TRUE if there
   is more text left in the buffer.  */
bool
_cpp_read_logical_line_trad (cpp_reader *pfile)
{
  do
    {
      if (pfile->buffer->need_line && !_cpp_get_fresh_line (pfile))
	return false;
    }
  while (!_cpp_scan_out_logical_line (pfile, NULL) || pfile->state.skipping);

  return pfile->buffer != NULL;
}

/* Set up state for finding the opening '(' of a function-like
   macro.  */
static void
maybe_start_funlike (cpp_reader *pfile, cpp_hashnode *node, const uchar *start, struct fun_macro *macro)
{
  unsigned int n = node->value.macro->paramc + 1;

  if (macro->buff)
    _cpp_release_buff (pfile, macro->buff);
  macro->buff = _cpp_get_buff (pfile, n * sizeof (size_t));
  macro->args = (size_t *) BUFF_FRONT (macro->buff);
  macro->node = node;
  macro->offset = start - pfile->out.base;
  macro->argc = 0;
}

/* Save the OFFSET of the start of the next argument to MACRO.  */
static void
save_argument (struct fun_macro *macro, size_t offset)
{
  macro->argc++;
  if (macro->argc <= macro->node->value.macro->paramc)
    macro->args[macro->argc] = offset;
}

/* Copies the next logical line in the current buffer (starting at
   buffer->cur) to the output buffer.  The output is guaranteed to
   terminate with a NUL character.  buffer->cur is updated.

   If MACRO is non-NULL, then we are scanning the replacement list of
   MACRO, and we call save_replacement_text() every time we meet an
   argument.  */
bool
_cpp_scan_out_logical_line (cpp_reader *pfile, cpp_macro *macro)
{
  bool result = true;
  cpp_context *context;
  const uchar *cur;
  uchar *out;
  struct fun_macro fmacro;
  unsigned int c, paren_depth = 0, quote;
  enum ls lex_state = ls_none;
  bool header_ok;
  const uchar *start_of_input_line;

  fmacro.buff = NULL;
  fmacro.args = NULL;
  fmacro.node = NULL;
  fmacro.offset = 0;
  fmacro.line = 0;
  fmacro.argc = 0;

  quote = 0;
  header_ok = pfile->state.angled_headers;
  CUR (pfile->context) = pfile->buffer->cur;
  RLIMIT (pfile->context) = pfile->buffer->rlimit;
  pfile->out.cur = pfile->out.base;
  pfile->out.first_line = pfile->line_table->highest_line;
  /* start_of_input_line is needed to make sure that directives really,
     really start at the first character of the line.  */
  start_of_input_line = pfile->buffer->cur;
 new_context:
  context = pfile->context;
  cur = CUR (context);
  check_output_buffer (pfile, RLIMIT (context) - cur);
  out = pfile->out.cur;

  for (;;)
    {
      if (!context->prev
	  && cur >= pfile->buffer->notes[pfile->buffer->cur_note].pos)
	{
	  pfile->buffer->cur = cur;
	  _cpp_process_line_notes (pfile, false);
	}
      c = *cur++;
      *out++ = c;

      /* Whitespace should "continue" out of the switch,
	 non-whitespace should "break" out of it.  */
      switch (c)
	{
	case ' ':
	case '\t':
	case '\f':
	case '\v':
	case '\0':
	  continue;

	case '\n':
	  /* If this is a macro's expansion, pop it.  */
	  if (context->prev)
	    {
	      pfile->out.cur = out - 1;
	      _cpp_pop_context (pfile);
	      goto new_context;
	    }

	  /* Omit the newline from the output buffer.  */
	  pfile->out.cur = out - 1;
	  pfile->buffer->cur = cur;
	  pfile->buffer->need_line = true;
	  CPP_INCREMENT_LINE (pfile, 0);

	  if ((lex_state == ls_fun_open || lex_state == ls_fun_close)
	      && !pfile->state.in_directive
	      && _cpp_get_fresh_line (pfile))
	    {
	      /* Newlines in arguments become a space, but we don't
		 clear any in-progress quote.  */
	      if (lex_state == ls_fun_close)
		out[-1] = ' ';
	      cur = pfile->buffer->cur;
	      continue;
	    }
	  goto done;

	case '<':
	  if (header_ok)
	    quote = '>';
	  break;
	case '>':
	  if (c == quote)
	    quote = 0;
	  break;

	case '"':
	case '\'':
	  if (c == quote)
	    quote = 0;
	  else if (!quote)
	    quote = c;
	  break;

	case '\\':
	  /* Skip escaped quotes here, it's easier than above.  */
	  if (*cur == '\\' || *cur == '"' || *cur == '\'')
	    *out++ = *cur++;
	  break;

	case '/':
	  /* Traditional CPP does not recognize comments within
	     literals.  */
	  if (!quote && *cur == '*')
	    {
	      pfile->out.cur = out;
	      cur = copy_comment (pfile, cur, macro != 0);
	      out = pfile->out.cur;
	      continue;
	    }
	  break;

	case '_':
	case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
	case 'g': case 'h': case 'i': case 'j': case 'k': case 'l':
	case 'm': case 'n': case 'o': case 'p': case 'q': case 'r':
	case 's': case 't': case 'u': case 'v': case 'w': case 'x':
	case 'y': case 'z':
	case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
	case 'G': case 'H': case 'I': case 'J': case 'K': case 'L':
	case 'M': case 'N': case 'O': case 'P': case 'Q': case 'R':
	case 'S': case 'T': case 'U': case 'V': case 'W': case 'X':
	case 'Y': case 'Z':
	  if (!pfile->state.skipping && (quote == 0 || macro))
	    {
	      cpp_hashnode *node;
	      uchar *out_start = out - 1;

	      pfile->out.cur = out_start;
	      node = lex_identifier (pfile, cur - 1);
	      out = pfile->out.cur;
	      cur = CUR (context);

	      if (node->type == NT_MACRO
		  /* Should we expand for ls_answer?  */
		  && (lex_state == ls_none || lex_state == ls_fun_open)
		  && !pfile->state.prevent_expansion)
		{
		  /* Macros invalidate MI optimization.  */
		  pfile->mi_valid = false;
		  if (! (node->flags & NODE_BUILTIN)
		      && node->value.macro->fun_like)
		    {
		      maybe_start_funlike (pfile, node, out_start, &fmacro);
		      lex_state = ls_fun_open;
		      fmacro.line = pfile->line_table->highest_line;
		      continue;
		    }
		  else if (!recursive_macro (pfile, node))
		    {
		      /* Remove the object-like macro's name from the
			 output, and push its replacement text.  */
		      pfile->out.cur = out_start;
		      push_replacement_text (pfile, node);
		      lex_state = ls_none;
		      goto new_context;
		    }
		}
	      else if (macro && (node->flags & NODE_MACRO_ARG) != 0)
		{
		  /* Found a parameter in the replacement text of a
		     #define.  Remove its name from the output.  */
		  pfile->out.cur = out_start;
		  save_replacement_text (pfile, macro, node->value.arg_index);
		  out = pfile->out.base;
		}
	      else if (lex_state == ls_hash)
		{
		  lex_state = ls_predicate;
		  continue;
		}
	      else if (pfile->state.in_expression
		       && node == pfile->spec_nodes.n_defined)
		{
		  lex_state = ls_defined;
		  continue;
		}
	    }
	  break;

	case '(':
	  if (quote == 0)
	    {
	      paren_depth++;
	      if (lex_state == ls_fun_open)
		{
		  if (recursive_macro (pfile, fmacro.node))
		    lex_state = ls_none;
		  else
		    {
		      lex_state = ls_fun_close;
		      paren_depth = 1;
		      out = pfile->out.base + fmacro.offset;
		      fmacro.args[0] = fmacro.offset;
		    }
		}
	      else if (lex_state == ls_predicate)
		lex_state = ls_answer;
	      else if (lex_state == ls_defined)
		lex_state = ls_defined_close;
	    }
	  break;

	case ',':
	  if (quote == 0 && lex_state == ls_fun_close && paren_depth == 1)
	    save_argument (&fmacro, out - pfile->out.base);
	  break;

	case ')':
	  if (quote == 0)
	    {
	      paren_depth--;
	      if (lex_state == ls_fun_close && paren_depth == 0)
		{
		  cpp_macro *m = fmacro.node->value.macro;

		  m->used = 1;
		  lex_state = ls_none;
		  save_argument (&fmacro, out - pfile->out.base);

		  /* A single zero-length argument is no argument.  */
		  if (fmacro.argc == 1
		      && m->paramc == 0
		      && out == pfile->out.base + fmacro.offset + 1)
		    fmacro.argc = 0;

		  if (_cpp_arguments_ok (pfile, m, fmacro.node, fmacro.argc))
		    {
		      /* Remove the macro's invocation from the
			 output, and push its replacement text.  */
		      pfile->out.cur = (pfile->out.base
					     + fmacro.offset);
		      CUR (context) = cur;
		      replace_args_and_push (pfile, &fmacro);
		      goto new_context;
		    }
		}
	      else if (lex_state == ls_answer || lex_state == ls_defined_close)
		lex_state = ls_none;
	    }
	  break;

	case '#':
	  if (cur - 1 == start_of_input_line
	      /* A '#' from a macro doesn't start a directive.  */
	      && !pfile->context->prev
	      && !pfile->state.in_directive)
	    {
	      /* A directive.  With the way _cpp_handle_directive
		 currently works, we only want to call it if either we
		 know the directive is OK, or we want it to fail and
		 be removed from the output.  If we want it to be
		 passed through (the assembler case) then we must not
		 call _cpp_handle_directive.  */
	      pfile->out.cur = out;
	      cur = skip_whitespace (pfile, cur, true /* skip_comments */);
	      out = pfile->out.cur;

	      if (*cur == '\n')
		{
		  /* Null directive.  Ignore it and don't invalidate
		     the MI optimization.  */
		  pfile->buffer->need_line = true;
		  CPP_INCREMENT_LINE (pfile, 0);
		  result = false;
		  goto done;
		}
	      else
		{
		  bool do_it = false;

		  if (is_numstart (*cur)
		      && CPP_OPTION (pfile, lang) != CLK_ASM)
		    do_it = true;
		  else if (is_idstart (*cur))
		    /* Check whether we know this directive, but don't
		       advance.  */
		    do_it = lex_identifier (pfile, cur)->is_directive;

		  if (do_it || CPP_OPTION (pfile, lang) != CLK_ASM)
		    {
		      /* This is a kludge.  We want to have the ISO
			 preprocessor lex the next token.  */
		      pfile->buffer->cur = cur;
		      _cpp_handle_directive (pfile, false /* indented */);
		      result = false;
		      goto done;
		    }
		}
	    }

	  if (pfile->state.in_expression)
	    {
	      lex_state = ls_hash;
	      continue;
	    }
	  break;

	default:
	  break;
	}

      /* Non-whitespace disables MI optimization and stops treating
	 '<' as a quote in #include.  */
      header_ok = false;
      if (!pfile->state.in_directive)
	pfile->mi_valid = false;

      if (lex_state == ls_none)
	continue;

      /* Some of these transitions of state are syntax errors.  The
	 ISO preprocessor will issue errors later.  */
      if (lex_state == ls_fun_open)
	/* Missing '('.  */
	lex_state = ls_none;
      else if (lex_state == ls_hash
	       || lex_state == ls_predicate
	       || lex_state == ls_defined)
	lex_state = ls_none;

      /* ls_answer and ls_defined_close keep going until ')'.  */
    }

 done:
  if (fmacro.buff)
    _cpp_release_buff (pfile, fmacro.buff);

  if (lex_state == ls_fun_close)
    cpp_error_with_line (pfile, CPP_DL_ERROR, fmacro.line, 0,
			 "unterminated argument list invoking macro \"%s\"",
			 NODE_NAME (fmacro.node));
  return result;
}

/* Push a context holding the replacement text of the macro NODE on
   the context stack.  NODE is either object-like, or a function-like
   macro with no arguments.  */
static void
push_replacement_text (cpp_reader *pfile, cpp_hashnode *node)
{
  size_t len;
  const uchar *text;
  uchar *buf;

  if (node->flags & NODE_BUILTIN)
    {
      text = _cpp_builtin_macro_text (pfile, node);
      len = ustrlen (text);
      buf = _cpp_unaligned_alloc (pfile, len + 1);
      memcpy (buf, text, len);
      buf[len]='\n';
      text = buf;
    }
  else
    {
      cpp_macro *macro = node->value.macro;
      macro->used = 1;
      text = macro->exp.text;
      macro->traditional = 1;
      len = macro->count;
    }

  _cpp_push_text_context (pfile, node, text, len);
}

/* Returns TRUE if traditional macro recursion is detected.  */
static bool
recursive_macro (cpp_reader *pfile, cpp_hashnode *node)
{
  bool recursing = !!(node->flags & NODE_DISABLED);

  /* Object-like macros that are already expanding are necessarily
     recursive.

     However, it is possible to have traditional function-like macros
     that are not infinitely recursive but recurse to any given depth.
     Further, it is easy to construct examples that get ever longer
     until the point they stop recursing.  So there is no easy way to
     detect true recursion; instead we assume any expansion more than
     20 deep since the first invocation of this macro must be
     recursing.  */
  if (recursing && node->value.macro->fun_like)
    {
      size_t depth = 0;
      cpp_context *context = pfile->context;

      do
	{
	  depth++;
	  if (context->macro == node && depth > 20)
	    break;
	  context = context->prev;
	}
      while (context);
      recursing = context != NULL;
    }

  if (recursing)
    cpp_error (pfile, CPP_DL_ERROR,
	       "detected recursion whilst expanding macro \"%s\"",
	       NODE_NAME (node));

  return recursing;
}

/* Return the length of the replacement text of a function-like or
   object-like non-builtin macro.  */
size_t
_cpp_replacement_text_len (const cpp_macro *macro)
{
  size_t len;

  if (macro->fun_like && (macro->paramc != 0))
    {
      const uchar *exp;

      len = 0;
      for (exp = macro->exp.text;;)
	{
	  struct block *b = (struct block *) exp;

	  len += b->text_len;
	  if (b->arg_index == 0)
	    break;
	  len += NODE_LEN (macro->params[b->arg_index - 1]);
	  exp += BLOCK_LEN (b->text_len);
	}
    }
  else
    len = macro->count;
  
  return len;
}

/* Copy the replacement text of MACRO to DEST, which must be of
   sufficient size.  It is not NUL-terminated.  The next character is
   returned.  */
uchar *
_cpp_copy_replacement_text (const cpp_macro *macro, uchar *dest)
{
  if (macro->fun_like && (macro->paramc != 0))
    {
      const uchar *exp;

      for (exp = macro->exp.text;;)
	{
	  struct block *b = (struct block *) exp;
	  cpp_hashnode *param;

	  memcpy (dest, b->text, b->text_len);
	  dest += b->text_len;
	  if (b->arg_index == 0)
	    break;
	  param = macro->params[b->arg_index - 1];
	  memcpy (dest, NODE_NAME (param), NODE_LEN (param));
	  dest += NODE_LEN (param);
	  exp += BLOCK_LEN (b->text_len);
	}
    }
  else
    {
      memcpy (dest, macro->exp.text, macro->count);
      dest += macro->count;
    }

  return dest;
}

/* Push a context holding the replacement text of the macro NODE on
   the context stack.  NODE is either object-like, or a function-like
   macro with no arguments.  */
static void
replace_args_and_push (cpp_reader *pfile, struct fun_macro *fmacro)
{
  cpp_macro *macro = fmacro->node->value.macro;

  if (macro->paramc == 0)
    push_replacement_text (pfile, fmacro->node);
  else
    {
      const uchar *exp;
      uchar *p;
      _cpp_buff *buff;
      size_t len = 0;
      int cxtquote = 0;

      /* Get an estimate of the length of the argument-replaced text.
	 This is a worst case estimate, assuming that every replacement
	 text character needs quoting.  */
      for (exp = macro->exp.text;;)
	{
	  struct block *b = (struct block *) exp;

	  len += b->text_len;
	  if (b->arg_index == 0)
	    break;
	  len += 2 * (fmacro->args[b->arg_index]
		      - fmacro->args[b->arg_index - 1] - 1);
	  exp += BLOCK_LEN (b->text_len);
	}

      /* Allocate room for the expansion plus \n.  */
      buff = _cpp_get_buff (pfile, len + 1);

      /* Copy the expansion and replace arguments.  */
      /* Accumulate actual length, including quoting as necessary */
      p = BUFF_FRONT (buff);
      len = 0;
      for (exp = macro->exp.text;;)
	{
	  struct block *b = (struct block *) exp;
	  size_t arglen;
	  int argquote;
	  uchar *base;
	  uchar *in;

	  len += b->text_len;
	  /* Copy the non-argument text literally, keeping
	     track of whether matching quotes have been seen. */
	  for (arglen = b->text_len, in = b->text; arglen > 0; arglen--)
	    {
	      if (*in == '"')
		cxtquote = ! cxtquote;
	      *p++ = *in++;
	    }
	  /* Done if no more arguments */
	  if (b->arg_index == 0)
	    break;
	  arglen = (fmacro->args[b->arg_index]
		    - fmacro->args[b->arg_index - 1] - 1);
	  base = pfile->out.base + fmacro->args[b->arg_index - 1];
	  in = base;
#if 0
	  /* Skip leading whitespace in the text for the argument to
	     be substituted. To be compatible with gcc 2.95, we would
	     also need to trim trailing whitespace. Gcc 2.95 trims
	     leading and trailing whitespace, which may be a bug.  The
	     current gcc testsuite explicitly checks that this leading
	     and trailing whitespace in actual arguments is
	     preserved. */
	  while (arglen > 0 && is_space (*in))
	    {
	      in++;
	      arglen--;
	    }
#endif
	  for (argquote = 0; arglen > 0; arglen--)
	    {
	      if (cxtquote && *in == '"')
		{
		  if (in > base && *(in-1) != '\\')
		    argquote = ! argquote;
		  /* Always add backslash before double quote if argument
		     is expanded in a quoted context */
		  *p++ = '\\';
		  len++;
		}
	      else if (cxtquote && argquote && *in == '\\')
		{
		  /* Always add backslash before a backslash in an argument
		     that is expanded in a quoted context and also in the
		     range of a quoted context in the argument itself. */
		  *p++ = '\\';
		  len++;
		}
	      *p++ = *in++;
	      len++;
	    }
	  exp += BLOCK_LEN (b->text_len);
	}

      /* \n-terminate.  */
      *p = '\n';
      _cpp_push_text_context (pfile, fmacro->node, BUFF_FRONT (buff), len);

      /* So we free buffer allocation when macro is left.  */
      pfile->context->buff = buff;
    }
}

/* Read and record the parameters, if any, of a function-like macro
   definition.  Destroys pfile->out.cur.

   Returns true on success, false on failure (syntax error or a
   duplicate parameter).  On success, CUR (pfile->context) is just
   past the closing parenthesis.  */
static bool
scan_parameters (cpp_reader *pfile, cpp_macro *macro)
{
  const uchar *cur = CUR (pfile->context) + 1;
  bool ok;

  for (;;)
    {
      cur = skip_whitespace (pfile, cur, true /* skip_comments */);

      if (is_idstart (*cur))
	{
	  ok = false;
	  if (_cpp_save_parameter (pfile, macro, lex_identifier (pfile, cur)))
	    break;
	  cur = skip_whitespace (pfile, CUR (pfile->context),
				 true /* skip_comments */);
	  if (*cur == ',')
	    {
	      cur++;
	      continue;
	    }
	  ok = (*cur == ')');
	  break;
	}

      ok = (*cur == ')' && macro->paramc == 0);
      break;
    }

  if (!ok)
    cpp_error (pfile, CPP_DL_ERROR, "syntax error in macro parameter list");

  CUR (pfile->context) = cur + (*cur == ')');

  return ok;
}

/* Save the text from pfile->out.base to pfile->out.cur as
   the replacement text for the current macro, followed by argument
   ARG_INDEX, with zero indicating the end of the replacement
   text.  */
static void
save_replacement_text (cpp_reader *pfile, cpp_macro *macro,
		       unsigned int arg_index)
{
  size_t len = pfile->out.cur - pfile->out.base;
  uchar *exp;

  if (macro->paramc == 0)
    {
      /* Object-like and function-like macros without parameters
	 simply store their \n-terminated replacement text.  */
      exp = _cpp_unaligned_alloc (pfile, len + 1);
      memcpy (exp, pfile->out.base, len);
      exp[len] = '\n';
      macro->exp.text = exp;
      macro->traditional = 1;
      macro->count = len;
    }
  else
    {
      /* Store the text's length (unsigned int), the argument index
	 (unsigned short, base 1) and then the text.  */
      size_t blen = BLOCK_LEN (len);
      struct block *block;

      if (macro->count + blen > BUFF_ROOM (pfile->a_buff))
	_cpp_extend_buff (pfile, &pfile->a_buff, macro->count + blen);

      exp = BUFF_FRONT (pfile->a_buff);
      block = (struct block *) (exp + macro->count);
      macro->exp.text = exp;
      macro->traditional = 1;

      /* Write out the block information.  */
      block->text_len = len;
      block->arg_index = arg_index;
      memcpy (block->text, pfile->out.base, len);

      /* Lex the rest into the start of the output buffer.  */
      pfile->out.cur = pfile->out.base;

      macro->count += blen;

      /* If we've finished, commit the memory.  */
      if (arg_index == 0)
	BUFF_FRONT (pfile->a_buff) += macro->count;
    }
}

/* Analyze and save the replacement text of a macro.  Returns true on
   success.  */
bool
_cpp_create_trad_definition (cpp_reader *pfile, cpp_macro *macro)
{
  const uchar *cur;
  uchar *limit;
  cpp_context *context = pfile->context;

  /* The context has not been set up for command line defines, and CUR
     has not been updated for the macro name for in-file defines.  */
  pfile->out.cur = pfile->out.base;
  CUR (context) = pfile->buffer->cur;
  RLIMIT (context) = pfile->buffer->rlimit;
  check_output_buffer (pfile, RLIMIT (context) - CUR (context));

  /* Is this a function-like macro?  */
  if (* CUR (context) == '(')
    {
      bool ok = scan_parameters (pfile, macro);

      /* Remember the params so we can clear NODE_MACRO_ARG flags.  */
      macro->params = (cpp_hashnode **) BUFF_FRONT (pfile->a_buff);

      /* Setting macro to NULL indicates an error occurred, and
	 prevents unnecessary work in _cpp_scan_out_logical_line.  */
      if (!ok)
	macro = NULL;
      else
	{
	  BUFF_FRONT (pfile->a_buff) = (uchar *) &macro->params[macro->paramc];
	  macro->fun_like = 1;
	}
    }

  /* Skip leading whitespace in the replacement text.  */
  pfile->buffer->cur
    = skip_whitespace (pfile, CUR (context),
		       CPP_OPTION (pfile, discard_comments_in_macro_exp));

  pfile->state.prevent_expansion++;
  _cpp_scan_out_logical_line (pfile, macro);
  pfile->state.prevent_expansion--;

  if (!macro)
    return false;

  /* Skip trailing white space.  */
  cur = pfile->out.base;
  limit = pfile->out.cur;
  while (limit > cur && is_space (limit[-1]))
    limit--;
  pfile->out.cur = limit;
  save_replacement_text (pfile, macro, 0);

  return true;
}

/* Copy SRC of length LEN to DEST, but convert all contiguous
   whitespace to a single space, provided it is not in quotes.  The
   quote currently in effect is pointed to by PQUOTE, and is updated
   by the function.  Returns the number of bytes copied.  */
static size_t
canonicalize_text (uchar *dest, const uchar *src, size_t len, uchar *pquote)
{
  uchar *orig_dest = dest;
  uchar quote = *pquote;

  while (len)
    {
      if (is_space (*src) && !quote)
	{
	  do
	    src++, len--;
	  while (len && is_space (*src));
	  *dest++ = ' ';
	}
      else
	{
	  if (*src == '\'' || *src == '"')
	    {
	      if (!quote)
		quote = *src;
	      else if (quote == *src)
		quote = 0;
	    }
	  *dest++ = *src++, len--;
	}
    }

  *pquote = quote;
  return dest - orig_dest;
}

/* Returns true if MACRO1 and MACRO2 have expansions different other
   than in the form of their whitespace.  */
bool
_cpp_expansions_different_trad (const cpp_macro *macro1,
				const cpp_macro *macro2)
{
  uchar *p1 = XNEWVEC (uchar, macro1->count + macro2->count);
  uchar *p2 = p1 + macro1->count;
  uchar quote1 = 0, quote2 = 0;
  bool mismatch;
  size_t len1, len2;

  if (macro1->paramc > 0)
    {
      const uchar *exp1 = macro1->exp.text, *exp2 = macro2->exp.text;

      mismatch = true;
      for (;;)
	{
	  struct block *b1 = (struct block *) exp1;
	  struct block *b2 = (struct block *) exp2;

	  if (b1->arg_index != b2->arg_index)
	    break;

	  len1 = canonicalize_text (p1, b1->text, b1->text_len, &quote1);
	  len2 = canonicalize_text (p2, b2->text, b2->text_len, &quote2);
	  if (len1 != len2 || memcmp (p1, p2, len1))
	    break;
	  if (b1->arg_index == 0)
	    {
	      mismatch = false;
	      break;
	    }
	  exp1 += BLOCK_LEN (b1->text_len);
	  exp2 += BLOCK_LEN (b2->text_len);
	}
    }
  else
    {
      len1 = canonicalize_text (p1, macro1->exp.text, macro1->count, &quote1);
      len2 = canonicalize_text (p2, macro2->exp.text, macro2->count, &quote2);
      mismatch = (len1 != len2 || memcmp (p1, p2, len1));
    }

  free (p1);
  return mismatch;
}