aboutsummaryrefslogtreecommitdiff
path: root/gas/macro.c
blob: 2173d00a17cb5ad19691666df49a526775fd2cd6 (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
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
/* macro.c - macro support for gas
   Copyright 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
   Free Software Foundation, Inc.

   Written by Steve and Judy Chamberlain of Cygnus Support,
      sac@cygnus.com

   This file is part of GAS, the GNU Assembler.

   GAS 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.

   GAS 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 GAS; 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"

#ifndef __GNUC__
# if HAVE_ALLOCA_H
#  include <alloca.h>
# else
#  ifdef _AIX
/* Indented so that pre-ansi C compilers will ignore it, rather than
   choke on it.  Some versions of AIX require this to be the first
   thing in the file.  */
 #pragma alloca
#  else
#   ifndef alloca /* predefined by HP cc +Olibcalls */
#    if !defined (__STDC__) && !defined (__hpux)
extern char *alloca ();
#    else
extern void *alloca ();
#    endif /* __STDC__, __hpux */
#   endif /* alloca */
#  endif /* _AIX */
# endif /* HAVE_ALLOCA_H */
#endif /* __GNUC__ */

#include <stdio.h>
#ifdef HAVE_STRING_H
#include <string.h>
#else
#include <strings.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include "as.h"
#include "libiberty.h"
#include "safe-ctype.h"
#include "sb.h"
#include "hash.h"
#include "macro.h"

#include "asintl.h"

/* The routines in this file handle macro definition and expansion.
   They are called by gas.  */

/* Internal functions.  */

static int get_token (int, sb *, sb *);
static int getstring (int, sb *, sb *);
static int get_any_string (int, sb *, sb *, int, int);
static int do_formals (macro_entry *, int, sb *);
static int get_apost_token (int, sb *, sb *, int);
static int sub_actual (int, sb *, sb *, struct hash_control *, int, sb *, int);
static const char *macro_expand_body
  (sb *, sb *, formal_entry *, struct hash_control *, int);
static const char *macro_expand (int, sb *, macro_entry *, sb *);

#define ISWHITE(x) ((x) == ' ' || (x) == '\t')

#define ISSEP(x) \
 ((x) == ' ' || (x) == '\t' || (x) == ',' || (x) == '"' || (x) == ';' \
  || (x) == ')' || (x) == '(' \
  || ((macro_alternate || macro_mri) && ((x) == '<' || (x) == '>')))

#define ISBASE(x) \
  ((x) == 'b' || (x) == 'B' \
   || (x) == 'q' || (x) == 'Q' \
   || (x) == 'h' || (x) == 'H' \
   || (x) == 'd' || (x) == 'D')

/* The macro hash table.  */

struct hash_control *macro_hash;

/* Whether any macros have been defined.  */

int macro_defined;

/* Whether we are in alternate syntax mode.  */

static int macro_alternate;

/* Whether we are in MRI mode.  */

static int macro_mri;

/* Whether we should strip '@' characters.  */

static int macro_strip_at;

/* Function to use to parse an expression.  */

static int (*macro_expr) (const char *, int, sb *, int *);

/* Number of macro expansions that have been done.  */

static int macro_number;

/* Initialize macro processing.  */

void
macro_init (int alternate, int mri, int strip_at,
	    int (*expr) (const char *, int, sb *, int *))
{
  macro_hash = hash_new ();
  macro_defined = 0;
  macro_alternate = alternate;
  macro_mri = mri;
  macro_strip_at = strip_at;
  macro_expr = expr;
}

/* Switch in and out of alternate mode on the fly.  */

void
macro_set_alternate (int alternate)
{
  macro_alternate = alternate;
}

/* Switch in and out of MRI mode on the fly.  */

void
macro_mri_mode (int mri)
{
  macro_mri = mri;
}

/* Read input lines till we get to a TO string.
   Increase nesting depth if we get a FROM string.
   Put the results into sb at PTR.
   Add a new input line to an sb using GET_LINE.
   Return 1 on success, 0 on unexpected EOF.  */

int
buffer_and_nest (const char *from, const char *to, sb *ptr,
		 int (*get_line) (sb *))
{
  int from_len = strlen (from);
  int to_len = strlen (to);
  int depth = 1;
  int line_start = ptr->len;

  int more = get_line (ptr);

  while (more)
    {
      /* Try and find the first pseudo op on the line.  */
      int i = line_start;

      if (! macro_alternate && ! macro_mri)
	{
	  /* With normal syntax we can suck what we want till we get
	     to the dot.  With the alternate, labels have to start in
	     the first column, since we cant tell what's a label and
	     whats a pseudoop.  */

	  /* Skip leading whitespace.  */
	  while (i < ptr->len && ISWHITE (ptr->ptr[i]))
	    i++;

	  /* Skip over a label.  */
	  while (i < ptr->len
		 && (ISALNUM (ptr->ptr[i])
		     || ptr->ptr[i] == '_'
		     || ptr->ptr[i] == '$'))
	    i++;

	  /* And a colon.  */
	  if (i < ptr->len
	      && ptr->ptr[i] == ':')
	    i++;

	}
      /* Skip trailing whitespace.  */
      while (i < ptr->len && ISWHITE (ptr->ptr[i]))
	i++;

      if (i < ptr->len && (ptr->ptr[i] == '.'
			   || macro_alternate
			   || macro_mri))
	{
	  if (ptr->ptr[i] == '.')
	    i++;
	  if (strncasecmp (ptr->ptr + i, from, from_len) == 0
	      && (ptr->len == (i + from_len)
		  || ! ISALNUM (ptr->ptr[i + from_len])))
	    depth++;
	  if (strncasecmp (ptr->ptr + i, to, to_len) == 0
	      && (ptr->len == (i + to_len)
		  || ! ISALNUM (ptr->ptr[i + to_len])))
	    {
	      depth--;
	      if (depth == 0)
		{
		  /* Reset the string to not include the ending rune.  */
		  ptr->len = line_start;
		  break;
		}
	    }
	}

      /* Add the original end-of-line char to the end and keep running.  */
      sb_add_char (ptr, more);
      line_start = ptr->len;
      more = get_line (ptr);
    }

  /* Return 1 on success, 0 on unexpected EOF.  */
  return depth == 0;
}

/* Pick up a token.  */

static int
get_token (int idx, sb *in, sb *name)
{
  if (idx < in->len
      && (ISALPHA (in->ptr[idx])
	  || in->ptr[idx] == '_'
	  || in->ptr[idx] == '$'))
    {
      sb_add_char (name, in->ptr[idx++]);
      while (idx < in->len
	     && (ISALNUM (in->ptr[idx])
		 || in->ptr[idx] == '_'
		 || in->ptr[idx] == '$'))
	{
	  sb_add_char (name, in->ptr[idx++]);
	}
    }
  /* Ignore trailing &.  */
  if (macro_alternate && idx < in->len && in->ptr[idx] == '&')
    idx++;
  return idx;
}

/* Pick up a string.  */

static int
getstring (int idx, sb *in, sb *acc)
{
  idx = sb_skip_white (idx, in);

  while (idx < in->len
	 && (in->ptr[idx] == '"'
	     || (in->ptr[idx] == '<' && (macro_alternate || macro_mri))
	     || (in->ptr[idx] == '\'' && macro_alternate)))
    {
      if (in->ptr[idx] == '<')
	{
	  int nest = 0;
	  idx++;
	  while ((in->ptr[idx] != '>' || nest)
		 && idx < in->len)
	    {
	      if (in->ptr[idx] == '!')
		{
		  idx++;
		  sb_add_char (acc, in->ptr[idx++]);
		}
	      else
		{
		  if (in->ptr[idx] == '>')
		    nest--;
		  if (in->ptr[idx] == '<')
		    nest++;
		  sb_add_char (acc, in->ptr[idx++]);
		}
	    }
	  idx++;
	}
      else if (in->ptr[idx] == '"' || in->ptr[idx] == '\'')
	{
	  char tchar = in->ptr[idx];
	  int escaped = 0;

	  idx++;

	  while (idx < in->len)
	    {
	      if (in->ptr[idx - 1] == '\\')
		escaped ^= 1;
	      else
		escaped = 0;

	      if (macro_alternate && in->ptr[idx] == '!')
		{
		  idx ++;

		  sb_add_char (acc, in->ptr[idx]);

		  idx ++;
		}
	      else if (escaped && in->ptr[idx] == tchar)
		{
		  sb_add_char (acc, tchar);
		  idx ++;
		}
	      else
		{
		  if (in->ptr[idx] == tchar)
		    {
		      idx ++;

		      if (idx >= in->len || in->ptr[idx] != tchar)
			break;
		    }

		  sb_add_char (acc, in->ptr[idx]);
		  idx ++;
		}
	    }
	}
    }

  return idx;
}

/* Fetch string from the input stream,
   rules:
    'Bxyx<whitespace>  	-> return 'Bxyza
    %<char>		-> return string of decimal value of x
    "<string>"		-> return string
    xyx<whitespace>     -> return xyz
*/

static int
get_any_string (int idx, sb *in, sb *out, int expand, int pretend_quoted)
{
  sb_reset (out);
  idx = sb_skip_white (idx, in);

  if (idx < in->len)
    {
      if (in->len > idx + 2 && in->ptr[idx + 1] == '\'' && ISBASE (in->ptr[idx]))
	{
	  while (!ISSEP (in->ptr[idx]))
	    sb_add_char (out, in->ptr[idx++]);
	}
      else if (in->ptr[idx] == '%'
	       && macro_alternate
	       && expand)
	{
	  int val;
	  char buf[20];
	  /* Turns the next expression into a string.  */
	  /* xgettext: no-c-format */
	  idx = (*macro_expr) (_("% operator needs absolute expression"),
			       idx + 1,
			       in,
			       &val);
	  sprintf (buf, "%d", val);
	  sb_add_string (out, buf);
	}
      else if (in->ptr[idx] == '"'
	       || (in->ptr[idx] == '<' && (macro_alternate || macro_mri))
	       || (macro_alternate && in->ptr[idx] == '\''))
	{
	  if (macro_alternate
	      && ! macro_strip_at
	      && expand)
	    {
	      /* Keep the quotes.  */
	      sb_add_char (out, '\"');

	      idx = getstring (idx, in, out);
	      sb_add_char (out, '\"');
	    }
	  else
	    {
	      idx = getstring (idx, in, out);
	    }
	}
      else
	{
	  while (idx < in->len
		 && (in->ptr[idx] == '"'
		     || in->ptr[idx] == '\''
		     || pretend_quoted
		     || (in->ptr[idx] != ' '
			 && in->ptr[idx] != '\t'
			 && in->ptr[idx] != ','
			 && (in->ptr[idx] != '<'
			     || (! macro_alternate && ! macro_mri)))))
	    {
	      if (in->ptr[idx] == '"'
		  || in->ptr[idx] == '\'')
		{
		  char tchar = in->ptr[idx];
		  sb_add_char (out, in->ptr[idx++]);
		  while (idx < in->len
			 && in->ptr[idx] != tchar)
		    sb_add_char (out, in->ptr[idx++]);
		  if (idx == in->len)
		    return idx;
		}
	      sb_add_char (out, in->ptr[idx++]);
	    }
	}
    }

  return idx;
}

/* Pick up the formal parameters of a macro definition.  */

static int
do_formals (macro_entry *macro, int idx, sb *in)
{
  formal_entry **p = &macro->formals;

  macro->formal_count = 0;
  macro->formal_hash = hash_new ();
  idx = sb_skip_white (idx, in);
  while (idx < in->len)
    {
      formal_entry *formal;
      int cidx;

      formal = (formal_entry *) xmalloc (sizeof (formal_entry));

      sb_new (&formal->name);
      sb_new (&formal->def);
      sb_new (&formal->actual);

      idx = get_token (idx, in, &formal->name);
      if (formal->name.len == 0)
	{
	  if (macro->formal_count)
	    --idx;
	  break;
	}
      idx = sb_skip_white (idx, in);
      /* This is a formal.  */
      if (idx < in->len && in->ptr[idx] == '=')
	{
	  /* Got a default.  */
	  idx = get_any_string (idx + 1, in, &formal->def, 1, 0);
	  idx = sb_skip_white (idx, in);
	}

      /* Add to macro's hash table.  */
      hash_jam (macro->formal_hash, sb_terminate (&formal->name), formal);

      formal->index = macro->formal_count++;
      cidx = idx;
      idx = sb_skip_comma (idx, in);
      if (idx != cidx && idx >= in->len)
	{
	  idx = cidx;
	  break;
	}
      *p = formal;
      p = &formal->next;
      *p = NULL;
    }

  if (macro_mri)
    {
      formal_entry *formal;
      const char *name;

      /* Add a special NARG formal, which macro_expand will set to the
         number of arguments.  */
      formal = (formal_entry *) xmalloc (sizeof (formal_entry));

      sb_new (&formal->name);
      sb_new (&formal->def);
      sb_new (&formal->actual);

      /* The same MRI assemblers which treat '@' characters also use
         the name $NARG.  At least until we find an exception.  */
      if (macro_strip_at)
	name = "$NARG";
      else
	name = "NARG";

      sb_add_string (&formal->name, name);

      /* Add to macro's hash table.  */
      hash_jam (macro->formal_hash, name, formal);

      formal->index = NARG_INDEX;
      *p = formal;
      formal->next = NULL;
    }

  return idx;
}

/* Define a new macro.  Returns NULL on success, otherwise returns an
   error message.  If NAMEP is not NULL, *NAMEP is set to the name of
   the macro which was defined.  */

const char *
define_macro (int idx, sb *in, sb *label,
	      int (*get_line) (sb *), const char **namep)
{
  macro_entry *macro;
  sb name;
  const char *namestr;

  macro = (macro_entry *) xmalloc (sizeof (macro_entry));
  sb_new (&macro->sub);
  sb_new (&name);

  macro->formal_count = 0;
  macro->formals = 0;

  idx = sb_skip_white (idx, in);
  if (! buffer_and_nest ("MACRO", "ENDM", &macro->sub, get_line))
    return _("unexpected end of file in macro definition");
  if (label != NULL && label->len != 0)
    {
      sb_add_sb (&name, label);
      if (idx < in->len && in->ptr[idx] == '(')
	{
	  /* It's the label: MACRO (formals,...)  sort  */
	  idx = do_formals (macro, idx + 1, in);
	  if (idx >= in->len || in->ptr[idx] != ')')
	    return _("missing ) after formals");
	  idx = sb_skip_white (idx + 1, in);
	}
      else
	{
	  /* It's the label: MACRO formals,...  sort  */
	  idx = do_formals (macro, idx, in);
	}
    }
  else
    {
      int cidx;

      idx = get_token (idx, in, &name);
      if (name.len == 0)
	return _("Missing macro name");
      cidx = sb_skip_white (idx, in);
      idx = sb_skip_comma (cidx, in);
      if (idx == cidx || idx < in->len)
	idx = do_formals (macro, idx, in);
      else
	idx = cidx;
    }
  if (idx < in->len)
    return _("Bad macro parameter list");

  /* And stick it in the macro hash table.  */
  for (idx = 0; idx < name.len; idx++)
    name.ptr[idx] = TOLOWER (name.ptr[idx]);
  namestr = sb_terminate (&name);
  if (hash_find (macro_hash, namestr))
    return _("Macro with this name was already defined");
  hash_jam (macro_hash, namestr, (PTR) macro);

  macro_defined = 1;

  if (namep != NULL)
    *namep = namestr;

  return NULL;
}

/* Scan a token, and then skip KIND.  */

static int
get_apost_token (int idx, sb *in, sb *name, int kind)
{
  idx = get_token (idx, in, name);
  if (idx < in->len
      && in->ptr[idx] == kind
      && (! macro_mri || macro_strip_at)
      && (! macro_strip_at || kind == '@'))
    idx++;
  return idx;
}

/* Substitute the actual value for a formal parameter.  */

static int
sub_actual (int start, sb *in, sb *t, struct hash_control *formal_hash,
	    int kind, sb *out, int copyifnotthere)
{
  int src;
  formal_entry *ptr;

  src = get_apost_token (start, in, t, kind);
  /* See if it's in the macro's hash table, unless this is
     macro_strip_at and kind is '@' and the token did not end in '@'.  */
  if (macro_strip_at
      && kind == '@'
      && (src == start || in->ptr[src - 1] != '@'))
    ptr = NULL;
  else
    ptr = (formal_entry *) hash_find (formal_hash, sb_terminate (t));
  if (ptr)
    {
      if (ptr->actual.len)
	{
	  sb_add_sb (out, &ptr->actual);
	}
      else
	{
	  sb_add_sb (out, &ptr->def);
	}
    }
  else if (kind == '&')
    {
      /* Doing this permits people to use & in macro bodies.  */
      sb_add_char (out, '&');
      sb_add_sb (out, t);
    }
  else if (copyifnotthere)
    {
      sb_add_sb (out, t);
    }
  else
    {
      sb_add_char (out, '\\');
      sb_add_sb (out, t);
    }
  return src;
}

/* Expand the body of a macro.  */

static const char *
macro_expand_body (sb *in, sb *out, formal_entry *formals,
		   struct hash_control *formal_hash, int locals)
{
  sb t;
  int src = 0;
  int inquote = 0;
  formal_entry *loclist = NULL;

  sb_new (&t);

  while (src < in->len)
    {
      if (in->ptr[src] == '&')
	{
	  sb_reset (&t);
	  if (macro_mri)
	    {
	      if (src + 1 < in->len && in->ptr[src + 1] == '&')
		src = sub_actual (src + 2, in, &t, formal_hash, '\'', out, 1);
	      else
		sb_add_char (out, in->ptr[src++]);
	    }
	  else
	    {
	      /* FIXME: Why do we do this?  */
	      src = sub_actual (src + 1, in, &t, formal_hash, '&', out, 0);
	    }
	}
      else if (in->ptr[src] == '\\')
	{
	  src++;
	  if (in->ptr[src] == '(')
	    {
	      /* Sub in till the next ')' literally.  */
	      src++;
	      while (src < in->len && in->ptr[src] != ')')
		{
		  sb_add_char (out, in->ptr[src++]);
		}
	      if (in->ptr[src] == ')')
		src++;
	      else
		return _("missplaced )");
	    }
	  else if (in->ptr[src] == '@')
	    {
	      /* Sub in the macro invocation number.  */

	      char buffer[10];
	      src++;
	      sprintf (buffer, "%d", macro_number);
	      sb_add_string (out, buffer);
	    }
	  else if (in->ptr[src] == '&')
	    {
	      /* This is a preprocessor variable name, we don't do them
		 here.  */
	      sb_add_char (out, '\\');
	      sb_add_char (out, '&');
	      src++;
	    }
	  else if (macro_mri && ISALNUM (in->ptr[src]))
	    {
	      int ind;
	      formal_entry *f;

	      if (ISDIGIT (in->ptr[src]))
		ind = in->ptr[src] - '0';
	      else if (ISUPPER (in->ptr[src]))
		ind = in->ptr[src] - 'A' + 10;
	      else
		ind = in->ptr[src] - 'a' + 10;
	      ++src;
	      for (f = formals; f != NULL; f = f->next)
		{
		  if (f->index == ind - 1)
		    {
		      if (f->actual.len != 0)
			sb_add_sb (out, &f->actual);
		      else
			sb_add_sb (out, &f->def);
		      break;
		    }
		}
	    }
	  else
	    {
	      sb_reset (&t);
	      src = sub_actual (src, in, &t, formal_hash, '\'', out, 0);
	    }
	}
      else if ((macro_alternate || macro_mri)
	       && (ISALPHA (in->ptr[src])
		   || in->ptr[src] == '_'
		   || in->ptr[src] == '$')
	       && (! inquote
		   || ! macro_strip_at
		   || (src > 0 && in->ptr[src - 1] == '@')))
	{
	  if (! locals
	      || src + 5 >= in->len
	      || strncasecmp (in->ptr + src, "LOCAL", 5) != 0
	      || ! ISWHITE (in->ptr[src + 5]))
	    {
	      sb_reset (&t);
	      src = sub_actual (src, in, &t, formal_hash,
				(macro_strip_at && inquote) ? '@' : '\'',
				out, 1);
	    }
	  else
	    {
	      formal_entry *f;

	      src = sb_skip_white (src + 5, in);
	      while (in->ptr[src] != '\n')
		{
		  static int loccnt;
		  char buf[20];
		  const char *err;

		  f = (formal_entry *) xmalloc (sizeof (formal_entry));
		  sb_new (&f->name);
		  sb_new (&f->def);
		  sb_new (&f->actual);
		  f->index = LOCAL_INDEX;
		  f->next = loclist;
		  loclist = f;

		  src = get_token (src, in, &f->name);
		  ++loccnt;
		  sprintf (buf, IS_ELF ? ".LL%04x" : "LL%04x", loccnt);
		  sb_add_string (&f->actual, buf);

		  err = hash_jam (formal_hash, sb_terminate (&f->name), f);
		  if (err != NULL)
		    return err;

		  src = sb_skip_comma (src, in);
		}
	    }
	}
      else if (in->ptr[src] == '"'
	       || (macro_mri && in->ptr[src] == '\''))
	{
	  inquote = !inquote;
	  sb_add_char (out, in->ptr[src++]);
	}
      else if (in->ptr[src] == '@' && macro_strip_at)
	{
	  ++src;
	  if (src < in->len
	      && in->ptr[src] == '@')
	    {
	      sb_add_char (out, '@');
	      ++src;
	    }
	}
      else if (macro_mri
	       && in->ptr[src] == '='
	       && src + 1 < in->len
	       && in->ptr[src + 1] == '=')
	{
	  formal_entry *ptr;

	  sb_reset (&t);
	  src = get_token (src + 2, in, &t);
	  ptr = (formal_entry *) hash_find (formal_hash, sb_terminate (&t));
	  if (ptr == NULL)
	    {
	      /* FIXME: We should really return a warning string here,
                 but we can't, because the == might be in the MRI
                 comment field, and, since the nature of the MRI
                 comment field depends upon the exact instruction
                 being used, we don't have enough information here to
                 figure out whether it is or not.  Instead, we leave
                 the == in place, which should cause a syntax error if
                 it is not in a comment.  */
	      sb_add_char (out, '=');
	      sb_add_char (out, '=');
	      sb_add_sb (out, &t);
	    }
	  else
	    {
	      if (ptr->actual.len)
		{
		  sb_add_string (out, "-1");
		}
	      else
		{
		  sb_add_char (out, '0');
		}
	    }
	}
      else
	{
	  sb_add_char (out, in->ptr[src++]);
	}
    }

  sb_kill (&t);

  while (loclist != NULL)
    {
      formal_entry *f;

      f = loclist->next;
      /* Setting the value to NULL effectively deletes the entry.  We
         avoid calling hash_delete because it doesn't reclaim memory.  */
      hash_jam (formal_hash, sb_terminate (&loclist->name), NULL);
      sb_kill (&loclist->name);
      sb_kill (&loclist->def);
      sb_kill (&loclist->actual);
      free (loclist);
      loclist = f;
    }

  return NULL;
}

/* Assign values to the formal parameters of a macro, and expand the
   body.  */

static const char *
macro_expand (int idx, sb *in, macro_entry *m, sb *out)
{
  sb t;
  formal_entry *ptr;
  formal_entry *f;
  int is_positional = 0;
  int is_keyword = 0;
  int narg = 0;
  const char *err;

  sb_new (&t);

  /* Reset any old value the actuals may have.  */
  for (f = m->formals; f; f = f->next)
    sb_reset (&f->actual);
  f = m->formals;
  while (f != NULL && f->index < 0)
    f = f->next;

  if (macro_mri)
    {
      /* The macro may be called with an optional qualifier, which may
         be referred to in the macro body as \0.  */
      if (idx < in->len && in->ptr[idx] == '.')
	{
	  /* The Microtec assembler ignores this if followed by a white space.
	     (Macro invocation with empty extension) */
	  idx++;
	  if (    idx < in->len
		  && in->ptr[idx] != ' '
		  && in->ptr[idx] != '\t')
	    {
	      formal_entry *n;

	      n = (formal_entry *) xmalloc (sizeof (formal_entry));
	      sb_new (&n->name);
	      sb_new (&n->def);
	      sb_new (&n->actual);
	      n->index = QUAL_INDEX;

	      n->next = m->formals;
	      m->formals = n;

	      idx = get_any_string (idx, in, &n->actual, 1, 0);
	    }
	}
    }

  /* Peel off the actuals and store them away in the hash tables' actuals.  */
  idx = sb_skip_white (idx, in);
  while (idx < in->len)
    {
      int scan;

      /* Look and see if it's a positional or keyword arg.  */
      scan = idx;
      while (scan < in->len
	     && !ISSEP (in->ptr[scan])
	     && !(macro_mri && in->ptr[scan] == '\'')
	     && (!macro_alternate && in->ptr[scan] != '='))
	scan++;
      if (scan < in->len && !macro_alternate && in->ptr[scan] == '=')
	{
	  is_keyword = 1;

	  /* It's OK to go from positional to keyword.  */

	  /* This is a keyword arg, fetch the formal name and
	     then the actual stuff.  */
	  sb_reset (&t);
	  idx = get_token (idx, in, &t);
	  if (in->ptr[idx] != '=')
	    return _("confusion in formal parameters");

	  /* Lookup the formal in the macro's list.  */
	  ptr = (formal_entry *) hash_find (m->formal_hash, sb_terminate (&t));
	  if (!ptr)
	    return _("macro formal argument does not exist");
	  else
	    {
	      /* Insert this value into the right place.  */
	      sb_reset (&ptr->actual);
	      idx = get_any_string (idx + 1, in, &ptr->actual, 0, 0);
	      if (ptr->actual.len > 0)
		++narg;
	    }
	}
      else
	{
	  /* This is a positional arg.  */
	  is_positional = 1;
	  if (is_keyword)
	    return _("can't mix positional and keyword arguments");

	  if (!f)
	    {
	      formal_entry **pf;
	      int c;

	      if (!macro_mri)
		return _("too many positional arguments");

	      f = (formal_entry *) xmalloc (sizeof (formal_entry));
	      sb_new (&f->name);
	      sb_new (&f->def);
	      sb_new (&f->actual);
	      f->next = NULL;

	      c = -1;
	      for (pf = &m->formals; *pf != NULL; pf = &(*pf)->next)
		if ((*pf)->index >= c)
		  c = (*pf)->index + 1;
	      if (c == -1)
		c = 0;
	      *pf = f;
	      f->index = c;
	    }

	  sb_reset (&f->actual);
	  idx = get_any_string (idx, in, &f->actual, 1, 0);
	  if (f->actual.len > 0)
	    ++narg;
	  do
	    {
	      f = f->next;
	    }
	  while (f != NULL && f->index < 0);
	}

      if (! macro_mri)
	idx = sb_skip_comma (idx, in);
      else
	{
	  if (in->ptr[idx] == ',')
	    ++idx;
	  if (ISWHITE (in->ptr[idx]))
	    break;
	}
    }

  if (macro_mri)
    {
      char buffer[20];

      sb_reset (&t);
      sb_add_string (&t, macro_strip_at ? "$NARG" : "NARG");
      ptr = (formal_entry *) hash_find (m->formal_hash, sb_terminate (&t));
      sb_reset (&ptr->actual);
      sprintf (buffer, "%d", narg);
      sb_add_string (&ptr->actual, buffer);
    }

  err = macro_expand_body (&m->sub, out, m->formals, m->formal_hash, 1);
  if (err != NULL)
    return err;

  /* Discard any unnamed formal arguments.  */
  if (macro_mri)
    {
      formal_entry **pf;

      pf = &m->formals;
      while (*pf != NULL)
	{
	  if ((*pf)->name.len != 0)
	    pf = &(*pf)->next;
	  else
	    {
	      sb_kill (&(*pf)->name);
	      sb_kill (&(*pf)->def);
	      sb_kill (&(*pf)->actual);
	      f = (*pf)->next;
	      free (*pf);
	      *pf = f;
	    }
	}
    }

  sb_kill (&t);
  macro_number++;

  return NULL;
}

/* Check for a macro.  If one is found, put the expansion into
   *EXPAND.  Return 1 if a macro is found, 0 otherwise.  */

int
check_macro (const char *line, sb *expand,
	     const char **error, macro_entry **info)
{
  const char *s;
  char *copy, *cs;
  macro_entry *macro;
  sb line_sb;

  if (! ISALPHA (*line)
      && *line != '_'
      && *line != '$'
      && (! macro_mri || *line != '.'))
    return 0;

  s = line + 1;
  while (ISALNUM (*s)
	 || *s == '_'
	 || *s == '$')
    ++s;

  copy = (char *) alloca (s - line + 1);
  memcpy (copy, line, s - line);
  copy[s - line] = '\0';
  for (cs = copy; *cs != '\0'; cs++)
    *cs = TOLOWER (*cs);

  macro = (macro_entry *) hash_find (macro_hash, copy);

  if (macro == NULL)
    return 0;

  /* Wrap the line up in an sb.  */
  sb_new (&line_sb);
  while (*s != '\0' && *s != '\n' && *s != '\r')
    sb_add_char (&line_sb, *s++);

  sb_new (expand);
  *error = macro_expand (0, &line_sb, macro, expand);

  sb_kill (&line_sb);

  /* Export the macro information if requested.  */
  if (info)
    *info = macro;

  return 1;
}

/* Delete a macro.  */

void
delete_macro (const char *name)
{
  hash_delete (macro_hash, name);
}

/* Handle the MRI IRP and IRPC pseudo-ops.  These are handled as a
   combined macro definition and execution.  This returns NULL on
   success, or an error message otherwise.  */

const char *
expand_irp (int irpc, int idx, sb *in, sb *out, int (*get_line) (sb *))
{
  const char *mn;
  sb sub;
  formal_entry f;
  struct hash_control *h;
  const char *err;

  if (irpc)
    mn = "IRPC";
  else
    mn = "IRP";

  idx = sb_skip_white (idx, in);

  sb_new (&sub);
  if (! buffer_and_nest (mn, "ENDR", &sub, get_line))
    return _("unexpected end of file in irp or irpc");

  sb_new (&f.name);
  sb_new (&f.def);
  sb_new (&f.actual);

  idx = get_token (idx, in, &f.name);
  if (f.name.len == 0)
    return _("missing model parameter");

  h = hash_new ();
  err = hash_jam (h, sb_terminate (&f.name), &f);
  if (err != NULL)
    return err;

  f.index = 1;
  f.next = NULL;

  sb_reset (out);

  idx = sb_skip_comma (idx, in);
  if (idx >= in->len)
    {
      /* Expand once with a null string.  */
      err = macro_expand_body (&sub, out, &f, h, 0);
      if (err != NULL)
	return err;
    }
  else
    {
      if (irpc && in->ptr[idx] == '"')
	++idx;
      while (idx < in->len)
	{
	  if (!irpc)
	    idx = get_any_string (idx, in, &f.actual, 1, 0);
	  else
	    {
	      if (in->ptr[idx] == '"')
		{
		  int nxt;

		  nxt = sb_skip_white (idx + 1, in);
		  if (nxt >= in->len)
		    {
		      idx = nxt;
		      break;
		    }
		}
	      sb_reset (&f.actual);
	      sb_add_char (&f.actual, in->ptr[idx]);
	      ++idx;
	    }
	  err = macro_expand_body (&sub, out, &f, h, 0);
	  if (err != NULL)
	    return err;
	  if (!irpc)
	    idx = sb_skip_comma (idx, in);
	  else
	    idx = sb_skip_white (idx, in);
	}
    }

  hash_die (h);
  sb_kill (&sub);

  return NULL;
}