summaryrefslogtreecommitdiff
path: root/gcc/read-md.c
blob: c108d51fd069742187831cb7132b080118e89822 (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
/* MD reader for GCC.
   Copyright (C) 1987-2013 Free Software Foundation, Inc.

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 3, 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 COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#include "bconfig.h"
#include "system.h"
#include "coretypes.h"
#include "hashtab.h"
#include "errors.h"
#include "read-md.h"

/* Associates PTR (which can be a string, etc.) with the file location
   specified by FILENAME and LINENO.  */
struct ptr_loc {
  const void *ptr;
  const char *filename;
  int lineno;
};

/* A singly-linked list of filenames.  */
struct file_name_list {
  struct file_name_list *next;
  const char *fname;
};

/* Obstack used for allocating MD strings.  */
struct obstack string_obstack;

/* A table of ptr_locs, hashed on the PTR field.  */
static htab_t ptr_locs;

/* An obstack for the above.  Plain xmalloc is a bit heavyweight for a
   small structure like ptr_loc.  */
static struct obstack ptr_loc_obstack;

/* A hash table of triples (A, B, C), where each of A, B and C is a condition
   and A is equivalent to "B && C".  This is used to keep track of the source
   of conditions that are made up of separate MD strings (such as the split
   condition of a define_insn_and_split).  */
static htab_t joined_conditions;

/* An obstack for allocating joined_conditions entries.  */
static struct obstack joined_conditions_obstack;

/* The file we are reading.  */
FILE *read_md_file;

/* The filename of READ_MD_FILE.  */
const char *read_md_filename;

/* The current line number in READ_MD_FILE.  */
int read_md_lineno;

/* The name of the toplevel file that indirectly included READ_MD_FILE.  */
const char *in_fname;

/* The directory part of IN_FNAME.  NULL if IN_FNAME is a bare filename.  */
static char *base_dir;

/* The first directory to search.  */
static struct file_name_list *first_dir_md_include;

/* A pointer to the null terminator of the md include chain.  */
static struct file_name_list **last_dir_md_include_ptr = &first_dir_md_include;

/* This callback will be invoked whenever an md include directive is
   processed.  To be used for creation of the dependency file.  */
void (*include_callback) (const char *);

/* The current maximum length of directory names in the search path
   for include files.  (Altered as we get more of them.)  */
static size_t max_include_len;

/* A table of md_constant structures, hashed by name.  Null if no
   constant expansion should occur.  */
static htab_t md_constants;

/* A table of enum_type structures, hashed by name.  */
static htab_t enum_types;

static void handle_file (directive_handler_t);

/* Given an object that starts with a char * name field, return a hash
   code for its name.  */

hashval_t
leading_string_hash (const void *def)
{
  return htab_hash_string (*(const char *const *) def);
}

/* Given two objects that start with char * name fields, return true if
   they have the same name.  */

int
leading_string_eq_p (const void *def1, const void *def2)
{
  return strcmp (*(const char *const *) def1,
		 *(const char *const *) def2) == 0;
}

/* Return a hash value for the pointer pointed to by DEF.  */

static hashval_t
leading_ptr_hash (const void *def)
{
  return htab_hash_pointer (*(const void *const *) def);
}

/* Return true if DEF1 and DEF2 are pointers to the same pointer.  */

static int
leading_ptr_eq_p (const void *def1, const void *def2)
{
  return *(const void *const *) def1 == *(const void *const *) def2;
}

/* Associate PTR with the file position given by FILENAME and LINENO.  */

static void
set_md_ptr_loc (const void *ptr, const char *filename, int lineno)
{
  struct ptr_loc *loc;

  loc = (struct ptr_loc *) obstack_alloc (&ptr_loc_obstack,
					  sizeof (struct ptr_loc));
  loc->ptr = ptr;
  loc->filename = filename;
  loc->lineno = lineno;
  *htab_find_slot (ptr_locs, loc, INSERT) = loc;
}

/* Return the position associated with pointer PTR.  Return null if no
   position was set.  */

static const struct ptr_loc *
get_md_ptr_loc (const void *ptr)
{
  return (const struct ptr_loc *) htab_find (ptr_locs, &ptr);
}

/* Associate NEW_PTR with the same file position as OLD_PTR.  */

void
copy_md_ptr_loc (const void *new_ptr, const void *old_ptr)
{
  const struct ptr_loc *loc = get_md_ptr_loc (old_ptr);
  if (loc != 0)
    set_md_ptr_loc (new_ptr, loc->filename, loc->lineno);
}

/* If PTR is associated with a known file position, print a #line
   directive for it to OUTF.  */

void
fprint_md_ptr_loc (FILE *outf, const void *ptr)
{
  const struct ptr_loc *loc = get_md_ptr_loc (ptr);
  if (loc != 0)
    fprintf (outf, "#line %d \"%s\"\n", loc->lineno, loc->filename);
}

/* Special fprint_md_ptr_loc for writing to STDOUT.  */
void
print_md_ptr_loc (const void *ptr)
{
  fprint_md_ptr_loc (stdout, ptr);
}

/* Return a condition that satisfies both COND1 and COND2.  Either string
   may be null or empty.  */

const char *
join_c_conditions (const char *cond1, const char *cond2)
{
  char *result;
  const void **entry;

  if (cond1 == 0 || cond1[0] == 0)
    return cond2;

  if (cond2 == 0 || cond2[0] == 0)
    return cond1;

  if (strcmp (cond1, cond2) == 0)
    return cond1;

  result = concat ("(", cond1, ") && (", cond2, ")", NULL);
  obstack_ptr_grow (&joined_conditions_obstack, result);
  obstack_ptr_grow (&joined_conditions_obstack, cond1);
  obstack_ptr_grow (&joined_conditions_obstack, cond2);
  entry = XOBFINISH (&joined_conditions_obstack, const void **);
  *htab_find_slot (joined_conditions, entry, INSERT) = entry;
  return result;
}

/* Print condition COND to OUTF, wrapped in brackets.  If COND was created
   by join_c_conditions, recursively invoke this function for the original
   conditions and join the result with "&&".  Otherwise print a #line
   directive for COND if its original file position is known.  */

void
fprint_c_condition (FILE *outf, const char *cond)
{
  const char **halves = (const char **) htab_find (joined_conditions, &cond);
  if (halves != 0)
    {
      fprintf (outf, "(");
      fprint_c_condition (outf, halves[1]);
      fprintf (outf, " && ");
      fprint_c_condition (outf, halves[2]);
      fprintf (outf, ")");
    }
  else
    {
      fputc ('\n', outf);
      fprint_md_ptr_loc (outf, cond);
      fprintf (outf, "(%s)", cond);
    }
}

/* Special fprint_c_condition for writing to STDOUT.  */

void
print_c_condition (const char *cond)
{
  fprint_c_condition (stdout, cond);
}

/* A vfprintf-like function for reporting an error against line LINENO
   of the current MD file.  */

static void ATTRIBUTE_PRINTF(2,0)
message_with_line_1 (int lineno, const char *msg, va_list ap)
{
  fprintf (stderr, "%s:%d: ", read_md_filename, lineno);
  vfprintf (stderr, msg, ap);
  fputc ('\n', stderr);
}

/* A printf-like function for reporting an error against line LINENO
   in the current MD file.  */

void
message_with_line (int lineno, const char *msg, ...)
{
  va_list ap;

  va_start (ap, msg);
  message_with_line_1 (lineno, msg, ap);
  va_end (ap);
}

/* Like message_with_line, but treat the condition as an error.  */

void
error_with_line (int lineno, const char *msg, ...)
{
  va_list ap;

  va_start (ap, msg);
  message_with_line_1 (lineno, msg, ap);
  va_end (ap);
  have_error = 1;
}

/* A printf-like function for reporting an error against the current
   position in the MD file.  */

void
fatal_with_file_and_line (const char *msg, ...)
{
  char context[64];
  size_t i;
  int c;
  va_list ap;

  va_start (ap, msg);

  fprintf (stderr, "%s:%d: ", read_md_filename, read_md_lineno);
  vfprintf (stderr, msg, ap);
  putc ('\n', stderr);

  /* Gather some following context.  */
  for (i = 0; i < sizeof (context)-1; ++i)
    {
      c = read_char ();
      if (c == EOF)
	break;
      if (c == '\r' || c == '\n')
	{
	  unread_char (c);
	  break;
	}
      context[i] = c;
    }
  context[i] = '\0';

  fprintf (stderr, "%s:%d: following context is `%s'\n",
	   read_md_filename, read_md_lineno, context);

  va_end (ap);
  exit (1);
}

/* Report that we found character ACTUAL when we expected to find
   character EXPECTED.  */

void
fatal_expected_char (int expected, int actual)
{
  if (actual == EOF)
    fatal_with_file_and_line ("expected character `%c', found EOF",
			      expected);
  else
    fatal_with_file_and_line ("expected character `%c', found `%c'",
			      expected, actual);
}

/* Read chars from the MD file until a non-whitespace char and return that.
   Comments, both Lisp style and C style, are treated as whitespace.  */

int
read_skip_spaces (void)
{
  int c;

  while (1)
    {
      c = read_char ();
      switch (c)
	{
	case ' ': case '\t': case '\f': case '\r': case '\n':
	  break;

	case ';':
	  do
	    c = read_char ();
	  while (c != '\n' && c != EOF);
	  break;

	case '/':
	  {
	    int prevc;
	    c = read_char ();
	    if (c != '*')
	      {
		unread_char (c);
		fatal_with_file_and_line ("stray '/' in file");
	      }

	    prevc = 0;
	    while ((c = read_char ()) && c != EOF)
	      {
		if (prevc == '*' && c == '/')
		  break;
	        prevc = c;
	      }
	  }
	  break;

	default:
	  return c;
	}
    }
}

/* Read an rtx code name into NAME.  It is terminated by any of the
   punctuation chars of rtx printed syntax.  */

void
read_name (struct md_name *name)
{
  int c;
  size_t i;

  c = read_skip_spaces ();

  i = 0;
  while (1)
    {
      if (c == ' ' || c == '\n' || c == '\t' || c == '\f' || c == '\r'
	  || c == EOF)
	break;
      if (c == ':' || c == ')' || c == ']' || c == '"' || c == '/'
	  || c == '(' || c == '[')
	{
	  unread_char (c);
	  break;
	}

      if (i == sizeof (name->buffer) - 1)
	fatal_with_file_and_line ("name too long");
      name->buffer[i++] = c;

      c = read_char ();
    }

  if (i == 0)
    fatal_with_file_and_line ("missing name or number");

  name->buffer[i] = 0;
  name->string = name->buffer;

  if (md_constants)
    {
      /* Do constant expansion.  */
      struct md_constant *def;

      do
	{
	  struct md_constant tmp_def;

	  tmp_def.name = name->string;
	  def = (struct md_constant *) htab_find (md_constants, &tmp_def);
	  if (def)
	    name->string = def->value;
	}
      while (def);
    }
}

/* Subroutine of the string readers.  Handles backslash escapes.
   Caller has read the backslash, but not placed it into the obstack.  */

static void
read_escape (void)
{
  int c = read_char ();

  switch (c)
    {
      /* Backslash-newline is replaced by nothing, as in C.  */
    case '\n':
      return;

      /* \" \' \\ are replaced by the second character.  */
    case '\\':
    case '"':
    case '\'':
      break;

      /* Standard C string escapes:
	 \a \b \f \n \r \t \v
	 \[0-7] \x
	 all are passed through to the output string unmolested.
	 In normal use these wind up in a string constant processed
	 by the C compiler, which will translate them appropriately.
	 We do not bother checking that \[0-7] are followed by up to
	 two octal digits, or that \x is followed by N hex digits.
	 \? \u \U are left out because they are not in traditional C.  */
    case 'a': case 'b': case 'f': case 'n': case 'r': case 't': case 'v':
    case '0': case '1': case '2': case '3': case '4': case '5': case '6':
    case '7': case 'x':
      obstack_1grow (&string_obstack, '\\');
      break;

      /* \; makes stuff for a C string constant containing
	 newline and tab.  */
    case ';':
      obstack_grow (&string_obstack, "\\n\\t", 4);
      return;

      /* pass anything else through, but issue a warning.  */
    default:
      fprintf (stderr, "%s:%d: warning: unrecognized escape \\%c\n",
	       read_md_filename, read_md_lineno, c);
      obstack_1grow (&string_obstack, '\\');
      break;
    }

  obstack_1grow (&string_obstack, c);
}

/* Read a double-quoted string onto the obstack.  Caller has scanned
   the leading quote.  */

char *
read_quoted_string (void)
{
  int c;

  while (1)
    {
      c = read_char (); /* Read the string  */
      if (c == '\\')
	{
	  read_escape ();
	  continue;
	}
      else if (c == '"' || c == EOF)
	break;

      obstack_1grow (&string_obstack, c);
    }

  obstack_1grow (&string_obstack, 0);
  return XOBFINISH (&string_obstack, char *);
}

/* Read a braced string (a la Tcl) onto the string obstack.  Caller
   has scanned the leading brace.  Note that unlike quoted strings,
   the outermost braces _are_ included in the string constant.  */

static char *
read_braced_string (void)
{
  int c;
  int brace_depth = 1;  /* caller-processed */
  unsigned long starting_read_md_lineno = read_md_lineno;

  obstack_1grow (&string_obstack, '{');
  while (brace_depth)
    {
      c = read_char (); /* Read the string  */

      if (c == '{')
	brace_depth++;
      else if (c == '}')
	brace_depth--;
      else if (c == '\\')
	{
	  read_escape ();
	  continue;
	}
      else if (c == EOF)
	fatal_with_file_and_line
	  ("missing closing } for opening brace on line %lu",
	   starting_read_md_lineno);

      obstack_1grow (&string_obstack, c);
    }

  obstack_1grow (&string_obstack, 0);
  return XOBFINISH (&string_obstack, char *);
}

/* Read some kind of string constant.  This is the high-level routine
   used by read_rtx.  It handles surrounding parentheses, leading star,
   and dispatch to the appropriate string constant reader.  */

char *
read_string (int star_if_braced)
{
  char *stringbuf;
  int saw_paren = 0;
  int c, old_lineno;

  c = read_skip_spaces ();
  if (c == '(')
    {
      saw_paren = 1;
      c = read_skip_spaces ();
    }

  old_lineno = read_md_lineno;
  if (c == '"')
    stringbuf = read_quoted_string ();
  else if (c == '{')
    {
      if (star_if_braced)
	obstack_1grow (&string_obstack, '*');
      stringbuf = read_braced_string ();
    }
  else
    fatal_with_file_and_line ("expected `\"' or `{', found `%c'", c);

  if (saw_paren)
    {
      c = read_skip_spaces ();
      if (c != ')')
	fatal_expected_char (')', c);
    }

  set_md_ptr_loc (stringbuf, read_md_filename, old_lineno);
  return stringbuf;
}

/* Skip the rest of a construct that started at line LINENO and that
   is currently nested by DEPTH levels of parentheses.  */

void
read_skip_construct (int depth, int lineno)
{
  struct md_name name;
  int c;

  do
    {
      c = read_skip_spaces ();
      if (c == EOF)
	{
	  error_with_line (lineno, "unterminated construct");
	  exit (1);
	}
      switch (c)
	{
	case '(':
	  depth++;
	  break;

	case ')':
	  depth--;
	  break;

	case ':':
	case '[':
	case ']':
	case '/':
	  break;

	case '\"':
	case '{':
	  unread_char (c);
	  read_string (false);
	  break;

	default:
	  unread_char (c);
	  read_name (&name);
	  break;
	}
    }
  while (depth > 0);
  unread_char (c);
}

/* Given a string, return the number of comma-separated elements in it.
   Return 0 for the null string.  */

int
n_comma_elts (const char *s)
{
  int n;

  if (*s == '\0')
    return 0;

  for (n = 1; *s; s++)
    if (*s == ',')
      n++;

  return n;
}

/* Given a pointer to a (char *), return a pointer to the beginning of the
   next comma-separated element in the string.  Advance the pointer given
   to the end of that element.  Return NULL if at end of string.  Caller
   is responsible for copying the string if necessary.  White space between
   a comma and an element is ignored.  */

const char *
scan_comma_elt (const char **pstr)
{
  const char *start;
  const char *p = *pstr;

  if (*p == ',')
    p++;
  while (ISSPACE (*p))
    p++;

  if (*p == '\0')
    return NULL;

  start = p;

  while (*p != ',' && *p != '\0')
    p++;

  *pstr = p;
  return start;
}

/* Convert STRING to uppercase.  */

void
upcase_string (char *string)
{
  int i;

  for (i = 0; string[i]; i++)
    string[i] = TOUPPER (string[i]);
}

/* Add a NAME = VALUE definition to md_constants-style hash table DEFS,
   where both NAME and VALUE are malloc()ed strings.  PARENT_ENUM is the
   enum to which NAME belongs, or null if NAME is a stand-alone constant.  */

static struct md_constant *
add_constant (htab_t defs, char *name, char *value,
	      struct enum_type *parent_enum)
{
  struct md_constant *def, tmp_def;
  void **entry_ptr;

  tmp_def.name = name;
  entry_ptr = htab_find_slot (defs, &tmp_def, INSERT);
  if (*entry_ptr)
    {
      def = (struct md_constant *) *entry_ptr;
      if (strcmp (def->value, value) != 0)
	fatal_with_file_and_line ("redefinition of `%s', was `%s', now `%s'",
				  def->name, def->value, value);
      else if (parent_enum || def->parent_enum)
	fatal_with_file_and_line ("redefinition of `%s'", def->name);
      free (name);
      free (value);
    }
  else
    {
      def = XNEW (struct md_constant);
      def->name = name;
      def->value = value;
      def->parent_enum = parent_enum;
      *entry_ptr = def;
    }
  return def;
}

/* Process a define_constants directive, starting with the optional space
   after the "define_constants".  */

static void
handle_constants (void)
{
  int c;
  htab_t defs;

  c = read_skip_spaces ();
  if (c != '[')
    fatal_expected_char ('[', c);

  /* Disable constant expansion during definition processing.  */
  defs = md_constants;
  md_constants = 0;
  while ( (c = read_skip_spaces ()) != ']')
    {
      struct md_name name, value;

      if (c != '(')
	fatal_expected_char ('(', c);

      read_name (&name);
      read_name (&value);
      add_constant (defs, xstrdup (name.string), xstrdup (value.string), 0);

      c = read_skip_spaces ();
      if (c != ')')
	fatal_expected_char (')', c);
    }
  md_constants = defs;
}

/* For every constant definition, call CALLBACK with two arguments:
   a pointer a pointer to the constant definition and INFO.
   Stop when CALLBACK returns zero.  */

void
traverse_md_constants (htab_trav callback, void *info)
{
  htab_traverse (md_constants, callback, info);
}

/* Return a malloc()ed decimal string that represents number NUMBER.  */

static char *
decimal_string (int number)
{
  /* A safe overestimate.  +1 for sign, +1 for null terminator.  */
  char buffer[sizeof (int) * CHAR_BIT + 1 + 1];

  sprintf (buffer, "%d", number);
  return xstrdup (buffer);
}

/* Process a define_enum or define_c_enum directive, starting with
   the optional space after the "define_enum".  LINENO is the line
   number on which the directive started and MD_P is true if the
   directive is a define_enum rather than a define_c_enum.  */

static void
handle_enum (int lineno, bool md_p)
{
  char *enum_name, *value_name;
  struct md_name name;
  struct enum_type *def;
  struct enum_value *ev;
  void **slot;
  int c;

  enum_name = read_string (false);
  slot = htab_find_slot (enum_types, &enum_name, INSERT);
  if (*slot)
    {
      def = (struct enum_type *) *slot;
      if (def->md_p != md_p)
	error_with_line (lineno, "redefining `%s' as a different type of enum",
			 enum_name);
    }
  else
    {
      def = XNEW (struct enum_type);
      def->name = enum_name;
      def->md_p = md_p;
      def->values = 0;
      def->tail_ptr = &def->values;
      def->num_values = 0;
      *slot = def;
    }

  c = read_skip_spaces ();
  if (c != '[')
    fatal_expected_char ('[', c);

  while ((c = read_skip_spaces ()) != ']')
    {
      if (c == EOF)
	{
	  error_with_line (lineno, "unterminated construct");
	  exit (1);
	}
      unread_char (c);
      read_name (&name);

      ev = XNEW (struct enum_value);
      ev->next = 0;
      if (md_p)
	{
	  value_name = concat (def->name, "_", name.string, NULL);
	  upcase_string (value_name);
	  ev->name = xstrdup (name.string);
	}
      else
	{
	  value_name = xstrdup (name.string);
	  ev->name = value_name;
	}
      ev->def = add_constant (md_constants, value_name,
			      decimal_string (def->num_values), def);

      *def->tail_ptr = ev;
      def->tail_ptr = &ev->next;
      def->num_values++;
    }
}

/* Try to find the definition of the given enum.  Return null on failure.  */

struct enum_type *
lookup_enum_type (const char *name)
{
  return (struct enum_type *) htab_find (enum_types, &name);
}

/* For every enum definition, call CALLBACK with two arguments:
   a pointer to the constant definition and INFO.  Stop when CALLBACK
   returns zero.  */

void
traverse_enum_types (htab_trav callback, void *info)
{
  htab_traverse (enum_types, callback, info);
}

/* Process an "include" directive, starting with the optional space
   after the "include".  Read in the file and use HANDLE_DIRECTIVE
   to process each unknown directive.  LINENO is the line number on
   which the "include" occurred.  */

static void
handle_include (int lineno, directive_handler_t handle_directive)
{
  const char *filename;
  const char *old_filename;
  int old_lineno;
  char *pathname;
  FILE *input_file, *old_file;

  filename = read_string (false);
  input_file = NULL;

  /* If the specified file name is absolute, skip the include stack.  */
  if (!IS_ABSOLUTE_PATH (filename))
    {
      struct file_name_list *stackp;

      /* Search the directory path, trying to open the file.  */
      for (stackp = first_dir_md_include; stackp; stackp = stackp->next)
	{
	  static const char sep[2] = { DIR_SEPARATOR, '\0' };

	  pathname = concat (stackp->fname, sep, filename, NULL);
	  input_file = fopen (pathname, "r");
	  if (input_file != NULL)
	    break;
	  free (pathname);
	}
    }

  /* If we haven't managed to open the file yet, try combining the
     filename with BASE_DIR.  */
  if (input_file == NULL)
    {
      if (base_dir)
	pathname = concat (base_dir, filename, NULL);
      else
	pathname = xstrdup (filename);
      input_file = fopen (pathname, "r");
    }

  if (input_file == NULL)
    {
      free (pathname);
      error_with_line (lineno, "include file `%s' not found", filename);
      return;
    }

  /* Save the old cursor.  Note that the LINENO argument to this
     function is the beginning of the include statement, while
     read_md_lineno has already been advanced.  */
  old_file = read_md_file;
  old_filename = read_md_filename;
  old_lineno = read_md_lineno;

  if (include_callback)
    include_callback (pathname);

  read_md_file = input_file;
  read_md_filename = pathname;
  handle_file (handle_directive);

  /* Restore the old cursor.  */
  read_md_file = old_file;
  read_md_filename = old_filename;
  read_md_lineno = old_lineno;

  /* Do not free the pathname.  It is attached to the various rtx
     queue elements.  */
}

/* Process the current file, assuming that read_md_file and
   read_md_filename are valid.  Use HANDLE_DIRECTIVE to handle
   unknown directives.  */

static void
handle_file (directive_handler_t handle_directive)
{
  struct md_name directive;
  int c, lineno;

  read_md_lineno = 1;
  while ((c = read_skip_spaces ()) != EOF)
    {
      lineno = read_md_lineno;
      if (c != '(')
	fatal_expected_char ('(', c);

      read_name (&directive);
      if (strcmp (directive.string, "define_constants") == 0)
	handle_constants ();
      else if (strcmp (directive.string, "define_enum") == 0)
	handle_enum (lineno, true);
      else if (strcmp (directive.string, "define_c_enum") == 0)
	handle_enum (lineno, false);
      else if (strcmp (directive.string, "include") == 0)
	handle_include (lineno, handle_directive);
      else if (handle_directive)
	handle_directive (lineno, directive.string);
      else
	read_skip_construct (1, lineno);

      c = read_skip_spaces ();
      if (c != ')')
	fatal_expected_char (')', c);
    }
  fclose (read_md_file);
}

/* Like handle_file, but for top-level files.  Set up in_fname and
   base_dir accordingly.  */

static void
handle_toplevel_file (directive_handler_t handle_directive)
{
  const char *base;

  in_fname = read_md_filename;
  base = lbasename (in_fname);
  if (base == in_fname)
    base_dir = NULL;
  else
    base_dir = xstrndup (in_fname, base - in_fname);

  handle_file (handle_directive);
}

/* Parse a -I option with argument ARG.  */

static void
parse_include (const char *arg)
{
  struct file_name_list *dirtmp;

  dirtmp = XNEW (struct file_name_list);
  dirtmp->next = 0;
  dirtmp->fname = arg;
  *last_dir_md_include_ptr = dirtmp;
  last_dir_md_include_ptr = &dirtmp->next;
  if (strlen (dirtmp->fname) > max_include_len)
    max_include_len = strlen (dirtmp->fname);
}

/* The main routine for reading .md files.  Try to process all the .md
   files specified on the command line and return true if no error occurred.

   ARGC and ARGV are the arguments to main.

   PARSE_OPT, if nonnull, is passed all unknown command-line arguments.
   It should return true if it recognizes the argument or false if a
   generic error should be reported.

   If HANDLE_DIRECTIVE is nonnull, the parser calls it for each
   unknown directive, otherwise it just skips such directives.
   See the comment above the directive_handler_t definition for
   details about the callback's interface.  */

bool
read_md_files (int argc, char **argv, bool (*parse_opt) (const char *),
	       directive_handler_t handle_directive)
{
  int i;
  bool no_more_options;
  bool already_read_stdin;
  int num_files;

  /* Initialize global data.  */
  obstack_init (&string_obstack);
  ptr_locs = htab_create (161, leading_ptr_hash, leading_ptr_eq_p, 0);
  obstack_init (&ptr_loc_obstack);
  joined_conditions = htab_create (161, leading_ptr_hash, leading_ptr_eq_p, 0);
  obstack_init (&joined_conditions_obstack);
  md_constants = htab_create (31, leading_string_hash,
			      leading_string_eq_p, (htab_del) 0);
  enum_types = htab_create (31, leading_string_hash,
			    leading_string_eq_p, (htab_del) 0);

  /* Unlock the stdio streams.  */
  unlock_std_streams ();

  /* First we loop over all the options.  */
  for (i = 1; i < argc; i++)
    if (argv[i][0] == '-')
      {
	/* An argument consisting of exactly one dash is a request to
	   read stdin.  This will be handled in the second loop.  */
	if (argv[i][1] == '\0')
	  continue;

	/* An argument consisting of just two dashes causes option
	   parsing to cease.  */
	if (argv[i][1] == '-' && argv[i][2] == '\0')
	  break;

	if (argv[i][1] == 'I')
	  {
	    if (argv[i][2] != '\0')
	      parse_include (argv[i] + 2);
	    else if (++i < argc)
	      parse_include (argv[i]);
	    else
	      fatal ("directory name missing after -I option");
	    continue;
	  }

	/* The program may have provided a callback so it can
	   accept its own options.  */
	if (parse_opt && parse_opt (argv[i]))
	  continue;

	fatal ("invalid option `%s'", argv[i]);
      }

  /* Now loop over all input files.  */
  num_files = 0;
  no_more_options = false;
  already_read_stdin = false;
  for (i = 1; i < argc; i++)
    {
      if (argv[i][0] == '-')
	{
	  if (argv[i][1] == '\0')
	    {
	      /* Read stdin.  */
	      if (already_read_stdin)
		fatal ("cannot read standard input twice");

	      read_md_file = stdin;
	      read_md_filename = "<stdin>";
	      handle_toplevel_file (handle_directive);
	      already_read_stdin = true;
	      continue;
	    }
	  else if (argv[i][1] == '-' && argv[i][2] == '\0')
	    {
	      /* No further arguments are to be treated as options.  */
	      no_more_options = true;
	      continue;
	    }
	  else if (!no_more_options)
	    continue;
	}

      /* If we get here we are looking at a non-option argument, i.e.
	 a file to be processed.  */
      read_md_filename = argv[i];
      read_md_file = fopen (read_md_filename, "r");
      if (read_md_file == 0)
	{
	  perror (read_md_filename);
	  return false;
	}
      handle_toplevel_file (handle_directive);
      num_files++;
    }

  /* If we get to this point without having seen any files to process,
     read the standard input now.  */
  if (num_files == 0 && !already_read_stdin)
    {
      read_md_file = stdin;
      read_md_filename = "<stdin>";
      handle_toplevel_file (handle_directive);
    }

  return !have_error;
}