Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

   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
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
/* MD reader for GCC.
   Copyright (C) 1987-2020 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/>.  */

/* This file is compiled twice: once for the generator programs
   once for the compiler.  */
#ifdef GENERATOR_FILE
#include "bconfig.h"
#else
#include "config.h"
#endif
#include "system.h"
#include "coretypes.h"
#ifdef GENERATOR_FILE
#include "errors.h"
#endif /* #ifdef GENERATOR_FILE */
#include "statistics.h"
#include "vec.h"
#include "read-md.h"

#ifndef GENERATOR_FILE

/* Minimal reimplementation of errors.c for use by RTL frontend
   within cc1.  */

int have_error = 0;

#endif /* #ifndef GENERATOR_FILE */


/* 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 *);

/* Global singleton.  */

md_reader *md_reader_ptr;

/* 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 FILE_LOC.  */

void
md_reader::set_md_ptr_loc (const void *ptr, file_location file_loc)
{
  struct ptr_loc *loc;

  loc = (struct ptr_loc *) obstack_alloc (&m_ptr_loc_obstack,
					  sizeof (struct ptr_loc));
  loc->ptr = ptr;
  loc->loc = file_loc;
  *htab_find_slot (m_ptr_locs, loc, INSERT) = loc;
}

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

const md_reader::ptr_loc *
md_reader::get_md_ptr_loc (const void *ptr)
{
  return (const struct ptr_loc *) htab_find (m_ptr_locs, &ptr);
}

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

void
md_reader::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->loc);
}

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

void
md_reader::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->loc.lineno, loc->loc.filename);
}

/* Special fprint_md_ptr_loc for writing to STDOUT.  */
void
md_reader::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 *
md_reader::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 (&m_joined_conditions_obstack, result);
  obstack_ptr_grow (&m_joined_conditions_obstack, cond1);
  obstack_ptr_grow (&m_joined_conditions_obstack, cond2);
  entry = XOBFINISH (&m_joined_conditions_obstack, const void **);
  *htab_find_slot (m_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
md_reader::fprint_c_condition (FILE *outf, const char *cond)
{
  const char **halves = (const char **) htab_find (m_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
md_reader::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_at_1 (file_location loc, const char *msg, va_list ap)
{
  fprintf (stderr, "%s:%d:%d: ", loc.filename, loc.lineno, loc.colno);
  vfprintf (stderr, msg, ap);
  fputc ('\n', stderr);
}

/* A printf-like function for reporting a message against location LOC.  */

void
message_at (file_location loc, const char *msg, ...)
{
  va_list ap;

  va_start (ap, msg);
  message_at_1 (loc, msg, ap);
  va_end (ap);
}

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

void
error_at (file_location loc, const char *msg, ...)
{
  va_list ap;

  va_start (ap, msg);
  message_at_1 (loc, msg, ap);
  va_end (ap);
  have_error = 1;
}

/* Like message_at, but treat the condition as a fatal error.  */

void
fatal_at (file_location loc, const char *msg, ...)
{
  va_list ap;

  va_start (ap, msg);
  message_at_1 (loc, msg, ap);
  va_end (ap);
  exit (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:%d: error: ", md_reader_ptr->get_filename (),
	   md_reader_ptr->get_lineno (),
	   md_reader_ptr->get_colno ());
  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:%d: note: following context is `%s'\n",
	   md_reader_ptr->get_filename (),
	   md_reader_ptr->get_lineno (),
	   md_reader_ptr->get_colno (), 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;
	}
    }
}

/* Consume the next character, issuing a fatal error if it is not
   EXPECTED.  */

void
md_reader::require_char (char expected)
{
  int ch = read_char ();
  if (ch != expected)
    fatal_expected_char (expected, ch);
}

/* Consume any whitespace, then consume the next non-whitespace
   character, issuing a fatal error if it is not EXPECTED.  */

void
md_reader::require_char_ws (char expected)
{
  int ch = read_skip_spaces ();
  if (ch != expected)
    fatal_expected_char (expected, ch);
}

/* Consume any whitespace, then consume the next word (as per read_name),
   issuing a fatal error if it is not EXPECTED.  */

void
md_reader::require_word_ws (const char *expected)
{
  struct md_name name;
  read_name (&name);
  if (strcmp (name.string, expected))
    fatal_with_file_and_line ("missing '%s'", expected);
}

/* Read the next character from the file.  */

int
md_reader::read_char (void)
{
  int ch;

  ch = getc (m_read_md_file);
  if (ch == '\n')
    {
      m_read_md_lineno++;
      m_last_line_colno = m_read_md_colno;
      m_read_md_colno = 0;
    }
  else
    m_read_md_colno++;

  /* If we're filtering lines, treat everything before the range of
     interest as a space, and as EOF for everything after.  */
  if (m_first_line && m_last_line)
    {
      if (m_read_md_lineno < m_first_line)
	return ' ';
      if (m_read_md_lineno > m_last_line)
	return EOF;
    }

  return ch;
}

/* Put back CH, which was the last character read from the file.  */

void
md_reader::unread_char (int ch)
{
  if (ch == '\n')
    {
      m_read_md_lineno--;
      m_read_md_colno = m_last_line_colno;
    }
  else
    m_read_md_colno--;
  ungetc (ch, m_read_md_file);
}

/* Peek at the next character from the file without consuming it.  */

int
md_reader::peek_char (void)
{
  int ch = read_char ();
  unread_char (ch);
  return ch;
}

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

bool
md_reader::read_name_1 (struct md_name *name, file_location *out_loc)
{
  int c;
  size_t i;
  int angle_bracket_depth;

  c = read_skip_spaces ();

  *out_loc = get_current_location ();

  i = 0;
  angle_bracket_depth = 0;
  while (1)
    {
      if (c == '<')
	angle_bracket_depth++;

      if ((c == '>') && (angle_bracket_depth > 0))
	  angle_bracket_depth--;

      if (c == ' ' || c == '\n' || c == '\t' || c == '\f' || c == '\r'
	  || c == EOF)
	break;
      if (angle_bracket_depth == 0)
	{
	  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)
    return false;

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

  if (m_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 (m_md_constants, &tmp_def);
	  if (def)
	    name->string = def->value;
	}
      while (def);
    }

  return true;
}

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

file_location
md_reader::read_name (struct md_name *name)
{
  file_location loc;
  if (!read_name_1 (name, &loc))
    fatal_with_file_and_line ("missing name or number");
  return loc;
}

file_location
md_reader::read_name_or_nil (struct md_name *name)
{
  file_location loc;
  if (!read_name_1 (name, &loc))
    {
      file_location loc = get_current_location ();
      read_skip_construct (0, loc);
      /* Skip the ')'.  */
      read_char ();
      name->buffer[0] = 0;
      name->string = name->buffer;
    }
  return loc;
}

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

void
md_reader::read_escape ()
{
  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 (&m_string_obstack, '\\');
      break;

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

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

  obstack_1grow (&m_string_obstack, c);
}

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

char *
md_reader::read_quoted_string ()
{
  int c;

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

      obstack_1grow (&m_string_obstack, c);
    }

  obstack_1grow (&m_string_obstack, 0);
  return XOBFINISH (&m_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.  */

char *
md_reader::read_braced_string ()
{
  int c;
  int brace_depth = 1;  /* caller-processed */
  unsigned long starting_read_md_lineno = get_lineno ();

  obstack_1grow (&m_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 (&m_string_obstack, c);
    }

  obstack_1grow (&m_string_obstack, 0);
  return XOBFINISH (&m_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 *
md_reader::read_string (int star_if_braced)
{
  char *stringbuf;
  int saw_paren = 0;
  int c;

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

  file_location loc = get_current_location ();
  if (c == '"')
    stringbuf = read_quoted_string ();
  else if (c == '{')
    {
      if (star_if_braced)
	obstack_1grow (&m_string_obstack, '*');
      stringbuf = read_braced_string ();
    }
  else if (saw_paren && c == 'n')
    {
      /* Handle (nil) by returning NULL.  */
      require_char ('i');
      require_char ('l');
      require_char_ws (')');
      return NULL;
    }
  else
    fatal_with_file_and_line ("expected `\"' or `{', found `%c'", c);

  if (saw_paren)
    require_char_ws (')');

  set_md_ptr_loc (stringbuf, loc);
  return stringbuf;
}

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

void
md_reader::read_skip_construct (int depth, file_location loc)
{
  struct md_name name;
  int c;

  do
    {
      c = read_skip_spaces ();
      if (c == EOF)
	{
	  error_at (loc, "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".  */

void
md_reader::handle_constants ()
{
  int c;
  htab_t defs;

  require_char_ws ('[');

  /* Disable constant expansion during definition processing.  */
  defs = m_md_constants;
  m_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);

      require_char_ws (')');
    }
  m_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
md_reader::traverse_md_constants (htab_trav callback, void *info)
{
  htab_traverse (get_md_constants (), callback, info);
}

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

static char *
md_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.  */

void
md_reader::handle_enum (file_location loc, 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 (m_enum_types, &enum_name, INSERT);
  if (*slot)
    {
      def = (struct enum_type *) *slot;
      if (def->md_p != md_p)
	error_at (loc, "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;
    }

  require_char_ws ('[');

  while ((c = read_skip_spaces ()) != ']')
    {
      if (c == EOF)
	{
	  error_at (loc, "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 (get_md_constants (), value_name,
			      md_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 *
md_reader::lookup_enum_type (const char *name)
{
  return (struct enum_type *) htab_find (m_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
md_reader::traverse_enum_types (htab_trav callback, void *info)
{
  htab_traverse (m_enum_types, callback, info);
}


/* Constructor for md_reader.  */

md_reader::md_reader (bool compact)
: m_compact (compact),
  m_toplevel_fname (NULL),
  m_base_dir (NULL),
  m_read_md_file (NULL),
  m_read_md_filename (NULL),
  m_read_md_lineno (0),
  m_read_md_colno (0),
  m_first_dir_md_include (NULL),
  m_last_dir_md_include_ptr (&m_first_dir_md_include),
  m_first_line (0),
  m_last_line (0),
  m_first_overload (NULL),
  m_next_overload_ptr (&m_first_overload),
  m_overloads_htab (NULL)
{
  /* Set the global singleton pointer.  */
  md_reader_ptr = this;

  obstack_init (&m_string_obstack);

  m_ptr_locs = htab_create (161, leading_ptr_hash, leading_ptr_eq_p, 0);
  obstack_init (&m_ptr_loc_obstack);

  m_joined_conditions = htab_create (161, leading_ptr_hash, leading_ptr_eq_p, 0);
  obstack_init (&m_joined_conditions_obstack);

  m_md_constants = htab_create (31, leading_string_hash,
				leading_string_eq_p, (htab_del) 0);

  m_enum_types = htab_create (31, leading_string_hash,
			      leading_string_eq_p, (htab_del) 0);

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

/* md_reader's destructor.  */

md_reader::~md_reader ()
{
  free (m_base_dir);

  htab_delete (m_enum_types);

  htab_delete (m_md_constants);

  obstack_free (&m_joined_conditions_obstack, NULL);
  htab_delete (m_joined_conditions);

  obstack_free (&m_ptr_loc_obstack, NULL);
  htab_delete (m_ptr_locs);

  obstack_free (&m_string_obstack, NULL);

  /* Clear the global singleton pointer.  */
  md_reader_ptr = NULL;
}

/* 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.  */

void
md_reader::handle_include (file_location loc)
{
  const char *filename;
  const char *old_filename;
  int old_lineno, old_colno;
  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 = m_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 (m_base_dir)
	pathname = concat (m_base_dir, filename, NULL);
      else
	pathname = xstrdup (filename);
      input_file = fopen (pathname, "r");
    }

  if (input_file == NULL)
    {
      free (pathname);
      error_at (loc, "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 = m_read_md_file;
  old_filename = m_read_md_filename;
  old_lineno = m_read_md_lineno;
  old_colno = m_read_md_colno;

  if (include_callback)
    include_callback (pathname);

  m_read_md_file = input_file;
  m_read_md_filename = pathname;

  handle_file ();

  /* Restore the old cursor.  */
  m_read_md_file = old_file;
  m_read_md_filename = old_filename;
  m_read_md_lineno = old_lineno;
  m_read_md_colno = old_colno;

  /* 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.  */

void
md_reader::handle_file ()
{
  struct md_name directive;
  int c;

  m_read_md_lineno = 1;
  m_read_md_colno = 0;
  while ((c = read_skip_spaces ()) != EOF)
    {
      file_location loc = get_current_location ();
      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 (loc, true);
      else if (strcmp (directive.string, "define_c_enum") == 0)
	handle_enum (loc, false);
      else if (strcmp (directive.string, "include") == 0)
	handle_include (loc);
      else
	handle_unknown_directive (loc, directive.string);

      require_char_ws (')');
    }
  fclose (m_read_md_file);
}

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

void
md_reader::handle_toplevel_file ()
{
  const char *base;

  m_toplevel_fname = m_read_md_filename;
  base = lbasename (m_toplevel_fname);
  if (base == m_toplevel_fname)
    m_base_dir = NULL;
  else
    m_base_dir = xstrndup (m_toplevel_fname, base - m_toplevel_fname);

  handle_file ();
}

file_location
md_reader::get_current_location () const
{
  return file_location (m_read_md_filename, m_read_md_lineno, m_read_md_colno);
}

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

void
md_reader::add_include_path (const char *arg)
{
  struct file_name_list *dirtmp;

  dirtmp = XNEW (struct file_name_list);
  dirtmp->next = 0;
  dirtmp->fname = arg;
  *m_last_dir_md_include_ptr = dirtmp;
  m_last_dir_md_include_ptr = &dirtmp->next;
}

#ifdef GENERATOR_FILE

/* 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.  */

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

  /* 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')
	      add_include_path (argv[i] + 2);
	    else if (++i < argc)
	      add_include_path (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");

	      m_read_md_file = stdin;
	      m_read_md_filename = "<stdin>";
	      handle_toplevel_file ();
	      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.  */
      m_read_md_filename = argv[i];
      m_read_md_file = fopen (m_read_md_filename, "r");
      if (m_read_md_file == 0)
	{
	  perror (m_read_md_filename);
	  return false;
	}
      handle_toplevel_file ();
      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)
    {
      m_read_md_file = stdin;
      m_read_md_filename = "<stdin>";
      handle_toplevel_file ();
    }

  return !have_error;
}

#endif /* #ifdef GENERATOR_FILE */

/* Read FILENAME.  */

bool
md_reader::read_file (const char *filename)
{
  m_read_md_filename = filename;
  m_read_md_file = fopen (m_read_md_filename, "r");
  if (m_read_md_file == 0)
    {
      perror (m_read_md_filename);
      return false;
    }
  handle_toplevel_file ();
  return !have_error;
}

/* Read FILENAME, filtering to just the given lines.  */

bool
md_reader::read_file_fragment (const char *filename,
			       int first_line,
			       int last_line)
{
  m_read_md_filename = filename;
  m_read_md_file = fopen (m_read_md_filename, "r");
  if (m_read_md_file == 0)
    {
      perror (m_read_md_filename);
      return false;
    }
  m_first_line = first_line;
  m_last_line = last_line;
  handle_toplevel_file ();
  return !have_error;
}

/* class noop_reader : public md_reader */

/* A dummy implementation which skips unknown directives.  */
void
noop_reader::handle_unknown_directive (file_location loc, const char *)
{
  read_skip_construct (1, loc);
}