unofficial mirror of emacs-devel@gnu.org 
 help / color / mirror / code / Atom feed
blob f42c3e97b97784e7bf39cf28cd21b22ead12c4d4 46862 bytes (raw)
name: src/buffer.h 	 # note: path name is non-authoritative(*)

   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
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
 
/* Header file for the buffer manipulation primitives.

Copyright (C) 1985-1986, 1993-1995, 1997-2019 Free Software Foundation,
Inc.

This file is part of GNU Emacs.

GNU Emacs 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 of the License, or (at
your option) any later version.

GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */

#ifndef EMACS_BUFFER_H
#define EMACS_BUFFER_H

#include <sys/types.h>
#include <time.h>

#include "character.h"
#include "lisp.h"

INLINE_HEADER_BEGIN

/* Accessing the parameters of the current buffer.  */

/* These macros come in pairs, one for the char position
   and one for the byte position.  */

/* Position of beginning of buffer.  */
#define BEG (1)
#define BEG_BYTE (BEG)

/* Position of beginning of accessible range of buffer.  */
#define BEGV (current_buffer->begv)
#define BEGV_BYTE (current_buffer->begv_byte)

/* Position of point in buffer.  The "+ 0" makes this
   not an l-value, so you can't assign to it.  Use SET_PT instead.  */
#define PT (current_buffer->pt + 0)
#define PT_BYTE (current_buffer->pt_byte + 0)

/* Position of gap in buffer.  */
#define GPT (current_buffer->text->gpt)
#define GPT_BYTE (current_buffer->text->gpt_byte)

/* Position of end of accessible range of buffer.  */
#define ZV (current_buffer->zv)
#define ZV_BYTE (current_buffer->zv_byte)

/* Position of end of buffer.  */
#define Z (current_buffer->text->z)
#define Z_BYTE (current_buffer->text->z_byte)

/* Macros for the addresses of places in the buffer.  */

/* Address of beginning of buffer.  */
#define BEG_ADDR (current_buffer->text->beg)

/* Address of beginning of accessible range of buffer.  */
#define BEGV_ADDR (BYTE_POS_ADDR (current_buffer->begv_byte))

/* Address of point in buffer.  */
#define PT_ADDR (BYTE_POS_ADDR (current_buffer->pt_byte))

/* Address of beginning of gap in buffer.  */
#define GPT_ADDR (current_buffer->text->beg + current_buffer->text->gpt_byte - BEG_BYTE)

/* Address of end of gap in buffer.  */
#define GAP_END_ADDR (current_buffer->text->beg + current_buffer->text->gpt_byte + current_buffer->text->gap_size - BEG_BYTE)

/* Address of end of accessible range of buffer.  */
#define ZV_ADDR (BYTE_POS_ADDR (current_buffer->zv_byte))

/* Address of end of buffer.  */
#define Z_ADDR (current_buffer->text->beg + current_buffer->text->gap_size + current_buffer->text->z_byte - BEG_BYTE)

/* Size of gap.  */
#define GAP_SIZE (current_buffer->text->gap_size)

/* Modification count.  */
#define MODIFF (current_buffer->text->modiff)

/* Character modification count.  */
#define CHARS_MODIFF (current_buffer->text->chars_modiff)

/* Overlay modification count.  */
#define OVERLAY_MODIFF (current_buffer->text->overlay_modiff)

/* Modification count as of last visit or save.  */
#define SAVE_MODIFF (current_buffer->text->save_modiff)

/* BUFFER_CEILING_OF (resp. BUFFER_FLOOR_OF), when applied to n, return
   the max (resp. min) p such that

   BYTE_POS_ADDR (p) - BYTE_POS_ADDR (n) == p - n       */

#define BUFFER_CEILING_OF(BYTEPOS) \
  (((BYTEPOS) < GPT_BYTE && GPT < ZV ? GPT_BYTE : ZV_BYTE) - 1)
#define BUFFER_FLOOR_OF(BYTEPOS) \
  (BEGV <= GPT && GPT_BYTE <= (BYTEPOS) ? GPT_BYTE : BEGV_BYTE)
\f
/* Similar macros to operate on a specified buffer.
   Note that many of these evaluate the buffer argument more than once.  */

/* Position of beginning of buffer.  */
#define BUF_BEG(buf) (BEG)
#define BUF_BEG_BYTE(buf) (BEG_BYTE)

/* The BUF_BEGV[_BYTE], BUF_ZV[_BYTE], and BUF_PT[_BYTE] macros cannot
   be used for assignment; use SET_BUF_* macros below for that.  */

/* Position of beginning of accessible range of buffer.  */
#define BUF_BEGV(buf)					\
   (buf == current_buffer ? BEGV			\
    : NILP (BVAR (buf, begv_marker)) ? buf->begv	\
    : marker_position (BVAR (buf, begv_marker)))

#define BUF_BEGV_BYTE(buf)				\
   (buf == current_buffer ? BEGV_BYTE			\
    : NILP (BVAR (buf, begv_marker)) ? buf->begv_byte	\
    : marker_byte_position (BVAR (buf, begv_marker)))

/* Position of point in buffer.  */
#define BUF_PT(buf)					\
   (buf == current_buffer ? PT				\
    : NILP (BVAR (buf, pt_marker)) ? buf->pt		\
    : marker_position (BVAR (buf, pt_marker)))

#define BUF_PT_BYTE(buf)				\
   (buf == current_buffer ? PT_BYTE			\
    : NILP (BVAR (buf, pt_marker)) ? buf->pt_byte	\
    : marker_byte_position (BVAR (buf, pt_marker)))

/* Position of end of accessible range of buffer.  */
#define BUF_ZV(buf)					\
   (buf == current_buffer ? ZV				\
    : NILP (BVAR (buf, zv_marker)) ? buf->zv		\
    : marker_position (BVAR (buf, zv_marker)))

#define BUF_ZV_BYTE(buf)				\
   (buf == current_buffer ? ZV_BYTE			\
    : NILP (BVAR (buf, zv_marker)) ? buf->zv_byte	\
    : marker_byte_position (BVAR (buf, zv_marker)))

/* Position of gap in buffer.  */
#define BUF_GPT(buf) ((buf)->text->gpt)
#define BUF_GPT_BYTE(buf) ((buf)->text->gpt_byte)

/* Position of end of buffer.  */
#define BUF_Z(buf) ((buf)->text->z)
#define BUF_Z_BYTE(buf) ((buf)->text->z_byte)

/* Address of beginning of buffer.  */
#define BUF_BEG_ADDR(buf) ((buf)->text->beg)

/* Address of beginning of gap of buffer.  */
#define BUF_GPT_ADDR(buf) ((buf)->text->beg + (buf)->text->gpt_byte - BEG_BYTE)

/* Address of end of buffer.  */
#define BUF_Z_ADDR(buf) ((buf)->text->beg + (buf)->text->gap_size + (buf)->text->z_byte - BEG_BYTE)

/* Address of end of gap in buffer.  */
#define BUF_GAP_END_ADDR(buf) ((buf)->text->beg + (buf)->text->gpt_byte + (buf)->text->gap_size - BEG_BYTE)

/* Size of gap.  */
#define BUF_GAP_SIZE(buf) ((buf)->text->gap_size)

/* Modification count.  */
#define BUF_MODIFF(buf) ((buf)->text->modiff)

/* Character modification count.  */
#define BUF_CHARS_MODIFF(buf) ((buf)->text->chars_modiff)

/* Modification count as of last visit or save.  */
#define BUF_SAVE_MODIFF(buf) ((buf)->text->save_modiff)

/* Overlay modification count.  */
#define BUF_OVERLAY_MODIFF(buf) ((buf)->text->overlay_modiff)

/* Modification count as of last auto-save.  */
/* FIXME: should we move this into ->text->auto_save_modiff?  */
#define BUF_AUTOSAVE_MODIFF(buf) ((buf)->auto_save_modified)

/* Compaction count.  */
#define BUF_COMPACT(buf) ((buf)->text->compact)

/* Marker chain of buffer.  */
#define BUF_MARKERS(buf) ((buf)->text->markers)

#define BUF_UNCHANGED_MODIFIED(buf) \
  ((buf)->text->unchanged_modified)

#define BUF_OVERLAY_UNCHANGED_MODIFIED(buf) \
  ((buf)->text->overlay_unchanged_modified)
#define BUF_BEG_UNCHANGED(buf) ((buf)->text->beg_unchanged)
#define BUF_END_UNCHANGED(buf) ((buf)->text->end_unchanged)

#define UNCHANGED_MODIFIED \
  BUF_UNCHANGED_MODIFIED (current_buffer)
#define OVERLAY_UNCHANGED_MODIFIED \
  BUF_OVERLAY_UNCHANGED_MODIFIED (current_buffer)
#define BEG_UNCHANGED BUF_BEG_UNCHANGED (current_buffer)
#define END_UNCHANGED BUF_END_UNCHANGED (current_buffer)

/* Compute how many characters at the top and bottom of BUF are
   unchanged when the range START..END is modified.  This computation
   must be done each time BUF is modified.  */

#define BUF_COMPUTE_UNCHANGED(buf, start, end)				\
  do									\
    {									\
      if (BUF_UNCHANGED_MODIFIED (buf) == BUF_MODIFF (buf)		\
	  && (BUF_OVERLAY_UNCHANGED_MODIFIED (buf)			\
	      == BUF_OVERLAY_MODIFF (buf)))				\
	{								\
	  BUF_BEG_UNCHANGED (buf) = (start) - BUF_BEG (buf);		\
	  BUF_END_UNCHANGED (buf) = BUF_Z (buf) - (end);		\
	}								\
      else								\
	{								\
	  if (BUF_Z (buf) - (end) < BUF_END_UNCHANGED (buf))		\
	    BUF_END_UNCHANGED (buf) = BUF_Z (buf) - (end);		\
	  if ((start) - BUF_BEG (buf) < BUF_BEG_UNCHANGED (buf))	\
	    BUF_BEG_UNCHANGED (buf) = (start) - BUF_BEG (buf);		\
	}								\
    }									\
  while (false)

\f
/* Macros to set PT in the current buffer, or another buffer.  */

#define SET_PT(position) (set_point (position))
#define TEMP_SET_PT(position) (temp_set_point (current_buffer, (position)))

#define SET_PT_BOTH(position, byte) (set_point_both (position, byte))
#define TEMP_SET_PT_BOTH(position, byte) \
  (temp_set_point_both (current_buffer, (position), (byte)))

#define BUF_TEMP_SET_PT(buffer, position) \
  (temp_set_point ((buffer), (position)))

extern void set_point (ptrdiff_t);
extern void temp_set_point (struct buffer *, ptrdiff_t);
extern void set_point_both (ptrdiff_t, ptrdiff_t);
extern void temp_set_point_both (struct buffer *,
				 ptrdiff_t, ptrdiff_t);
extern void set_point_from_marker (Lisp_Object);
extern void enlarge_buffer_text (struct buffer *, ptrdiff_t);

\f
/* Macros for setting the BEGV, ZV or PT of a given buffer.

   The ..._BOTH macros take both a charpos and a bytepos,
   which must correspond to each other.

   The macros without ..._BOTH take just a charpos,
   and compute the bytepos from it.  */

#define SET_BUF_BEGV(buf, charpos)				 \
  ((buf)->begv_byte = buf_charpos_to_bytepos ((buf), (charpos)), \
   (buf)->begv = (charpos))

#define SET_BUF_ZV(buf, charpos)				\
  ((buf)->zv_byte = buf_charpos_to_bytepos ((buf), (charpos)),	\
   (buf)->zv = (charpos))

#define SET_BUF_BEGV_BOTH(buf, charpos, byte)		\
  ((buf)->begv = (charpos),				\
   (buf)->begv_byte = (byte))

#define SET_BUF_ZV_BOTH(buf, charpos, byte)		\
  ((buf)->zv = (charpos),				\
   (buf)->zv_byte = (byte))

#define SET_BUF_PT_BOTH(buf, charpos, byte)		\
  ((buf)->pt = (charpos),				\
   (buf)->pt_byte = (byte))
\f
/* Macros to access a character or byte in the current buffer,
   or convert between a byte position and an address.
   These macros do not check that the position is in range.  */

/* Maximum number of bytes in a buffer.
   A buffer cannot contain more bytes than a 1-origin fixnum can represent,
   nor can it be so large that C pointer arithmetic stops working.
   The ptrdiff_t cast ensures that this is signed, not unsigned.  */
#define BUF_BYTES_MAX \
  (ptrdiff_t) min (MOST_POSITIVE_FIXNUM - 1, min (SIZE_MAX, PTRDIFF_MAX))

/* Maximum gap size after compact_buffer, in bytes.  Also
   used in make_gap_larger to get some extra reserved space.  */

#define GAP_BYTES_DFL 2000

/* Minimum gap size after compact_buffer, in bytes.  Also
   used in make_gap_smaller to avoid too small gap size.  */

#define GAP_BYTES_MIN 20

/* Return the address of byte position N in current buffer.  */

#define BYTE_POS_ADDR(n) \
  (((n) >= GPT_BYTE ? GAP_SIZE : 0) + (n) + BEG_ADDR - BEG_BYTE)

/* Return the address of char position N.  */

#define CHAR_POS_ADDR(n)			\
  (((n) >= GPT ? GAP_SIZE : 0)			\
   + buf_charpos_to_bytepos (current_buffer, n)	\
   + BEG_ADDR - BEG_BYTE)

/* Convert a character position to a byte position.  */

#define CHAR_TO_BYTE(charpos)			\
  (buf_charpos_to_bytepos (current_buffer, charpos))

/* Convert a byte position to a character position.  */

#define BYTE_TO_CHAR(bytepos)			\
  (buf_bytepos_to_charpos (current_buffer, bytepos))

/* Convert PTR, the address of a byte in the buffer, into a byte position.  */

#define PTR_BYTE_POS(ptr) \
  ((ptr) - (current_buffer)->text->beg					    \
   - (ptr - (current_buffer)->text->beg <= GPT_BYTE - BEG_BYTE ? 0 : GAP_SIZE) \
   + BEG_BYTE)

/* Return character at byte position POS.  See the caveat WARNING for
   FETCH_MULTIBYTE_CHAR below.  */

#define FETCH_CHAR(pos)				      	\
  (!NILP (BVAR (current_buffer, enable_multibyte_characters))	\
   ? FETCH_MULTIBYTE_CHAR ((pos))		      	\
   : FETCH_BYTE ((pos)))

/* Return the byte at byte position N.  */

#define FETCH_BYTE(n) *(BYTE_POS_ADDR ((n)))

/* Return character at byte position POS.  If the current buffer is unibyte
   and the character is not ASCII, make the returning character
   multibyte.  */

#define FETCH_CHAR_AS_MULTIBYTE(pos)			\
  (!NILP (BVAR (current_buffer, enable_multibyte_characters))	\
   ? FETCH_MULTIBYTE_CHAR ((pos))			\
   : UNIBYTE_TO_CHAR (FETCH_BYTE ((pos))))

\f
/* Macros for accessing a character or byte,
   or converting between byte positions and addresses,
   in a specified buffer.  */

/* Return the address of character at byte position POS in buffer BUF.
   Note that both arguments can be computed more than once.  */

#define BUF_BYTE_ADDRESS(buf, pos) \
  ((buf)->text->beg + (pos) - BEG_BYTE \
   + ((pos) >= (buf)->text->gpt_byte ? (buf)->text->gap_size : 0))

/* Return the address of character at char position POS in buffer BUF.
   Note that both arguments can be computed more than once.  */

#define BUF_CHAR_ADDRESS(buf, pos) \
  ((buf)->text->beg + buf_charpos_to_bytepos ((buf), (pos)) - BEG_BYTE	\
   + ((pos) >= (buf)->text->gpt ? (buf)->text->gap_size : 0))

/* Convert PTR, the address of a char in buffer BUF,
   into a character position.  */

#define BUF_PTR_BYTE_POS(buf, ptr)				\
  ((ptr) - (buf)->text->beg					\
   - (ptr - (buf)->text->beg <= BUF_GPT_BYTE (buf) - BEG_BYTE	\
      ? 0 : BUF_GAP_SIZE ((buf)))				\
   + BEG_BYTE)

/* Return the character at byte position POS in buffer BUF.   */

#define BUF_FETCH_CHAR(buf, pos)	      	\
  (!NILP (buf->enable_multibyte_characters)	\
   ? BUF_FETCH_MULTIBYTE_CHAR ((buf), (pos))    \
   : BUF_FETCH_BYTE ((buf), (pos)))

/* Return character at byte position POS in buffer BUF.  If BUF is
   unibyte and the character is not ASCII, make the returning
   character multibyte.  */

#define BUF_FETCH_CHAR_AS_MULTIBYTE(buf, pos)           \
  (! NILP (BVAR ((buf), enable_multibyte_characters))   \
   ? BUF_FETCH_MULTIBYTE_CHAR ((buf), (pos))            \
   : UNIBYTE_TO_CHAR (BUF_FETCH_BYTE ((buf), (pos))))

/* Return the byte at byte position N in buffer BUF.   */

#define BUF_FETCH_BYTE(buf, n) \
  *(BUF_BYTE_ADDRESS ((buf), (n)))
\f
/* Define the actual buffer data structures.  */

/* This data structure describes the actual text contents of a buffer.
   It is shared between indirect buffers and their base buffer.  */

struct buffer_text
  {
    /* Actual address of buffer contents.  If REL_ALLOC is defined,
       this address might change when blocks are relocated which can
       e.g. happen when malloc is called.  So, don't pass a pointer
       into a buffer's text to functions that malloc.  */
    unsigned char *beg;

    ptrdiff_t gpt;		/* Char pos of gap in buffer.  */
    ptrdiff_t z;		/* Char pos of end of buffer.  */
    ptrdiff_t gpt_byte;		/* Byte pos of gap in buffer.  */
    ptrdiff_t z_byte;		/* Byte pos of end of buffer.  */
    ptrdiff_t gap_size;		/* Size of buffer's gap.  */
    modiff_count modiff;	/* This counts buffer-modification events
				   for this buffer.  It is incremented for
				   each such event, and never otherwise
				   changed.  */
    modiff_count chars_modiff;	/* This is modified with character change
				   events for this buffer.  It is set to
				   modiff for each such event, and never
				   otherwise changed.  */
    modiff_count save_modiff;	/* Previous value of modiff, as of last
				   time buffer visited or saved a file.  */

    modiff_count overlay_modiff; /* Counts modifications to overlays.  */

    modiff_count compact;	/* Set to modiff each time when compact_buffer
				   is called for this buffer.  */

    /* Minimum value of GPT - BEG since last redisplay that finished.  */
    ptrdiff_t beg_unchanged;

    /* Minimum value of Z - GPT since last redisplay that finished.  */
    ptrdiff_t end_unchanged;

    /* MODIFF as of last redisplay that finished; if it matches MODIFF,
       beg_unchanged and end_unchanged contain no useful information.  */
    modiff_count unchanged_modified;

    /* BUF_OVERLAY_MODIFF of current buffer, as of last redisplay that
       finished; if it matches BUF_OVERLAY_MODIFF, beg_unchanged and
       end_unchanged contain no useful information.  */
    modiff_count overlay_unchanged_modified;

    /* Properties of this buffer's text.  */
    INTERVAL intervals;

    /* The markers that refer to this buffer.
       This is actually a single marker ---
       successive elements in its marker `chain'
       are the other markers referring to this buffer.
       This is a singly linked unordered list, which means that it's
       very cheap to add a marker to the list and it's also very cheap
       to move a marker within a buffer.  */
    struct Lisp_Marker *markers;

    /* Usually false.  Temporarily true in decode_coding_gap to
       prevent Fgarbage_collect from shrinking the gap and losing
       not-yet-decoded bytes.  */
    bool_bf inhibit_shrinking : 1;

    /* True if it needs to be redisplayed.  */
    bool_bf redisplay : 1;
  };

/* Most code should use this macro to access Lisp fields in struct buffer.  */

#define BVAR(buf, field) ((buf)->field ## _)

/* This is the structure that the buffer Lisp object points to.  */

struct buffer
{
  union vectorlike_header header;

  /* The name of this buffer.  */
  Lisp_Object name_;

  /* The name of the file visited in this buffer, or nil.  */
  Lisp_Object filename_;

  /* Directory for expanding relative file names.  */
  Lisp_Object directory_;

  /* True if this buffer has been backed up (if you write to the visited
     file and it hasn't been backed up, then a backup will be made).  */
  Lisp_Object backed_up_;

  /* Length of file when last read or saved.
     -1 means auto saving turned off because buffer shrank a lot.
     -2 means don't turn off auto saving if buffer shrinks.
       (That value is used with buffer-swap-text.)
     This is not in the  struct buffer_text
     because it's not used in indirect buffers at all.  */
  Lisp_Object save_length_;

  /* File name used for auto-saving this buffer.
     This is not in the  struct buffer_text
     because it's not used in indirect buffers at all.  */
  Lisp_Object auto_save_file_name_;

  /* Non-nil if buffer read-only.  */
  Lisp_Object read_only_;

  /* "The mark".  This is a marker which may
     point into this buffer or may point nowhere.  */
  Lisp_Object mark_;

  /* Alist of elements (SYMBOL . VALUE-IN-THIS-BUFFER) for all
     per-buffer variables of this buffer.  For locally unbound
     symbols, just the symbol appears as the element.  */
  Lisp_Object local_var_alist_;

  /* Symbol naming major mode (e.g., lisp-mode).  */
  Lisp_Object major_mode_;

  /* Pretty name of major mode (e.g., "Lisp"). */
  Lisp_Object mode_name_;

  /* Mode line element that controls format of mode line.  */
  Lisp_Object mode_line_format_;

  /* Analogous to mode_line_format for the line displayed at the top
     of windows.  Nil means don't display that line.  */
  Lisp_Object header_line_format_;

  /* Keys that are bound local to this buffer.  */
  Lisp_Object keymap_;

  /* This buffer's local abbrev table.  */
  Lisp_Object abbrev_table_;

  /* This buffer's syntax table.  */
  Lisp_Object syntax_table_;

  /* This buffer's category table.  */
  Lisp_Object category_table_;

  /* Values of several buffer-local variables.  */
  /* tab-width is buffer-local so that redisplay can find it
     in buffers that are not current.  */
  Lisp_Object case_fold_search_;
  Lisp_Object tab_width_;
  Lisp_Object fill_column_;
  Lisp_Object left_margin_;

  /* Function to call when insert space past fill column.  */
  Lisp_Object auto_fill_function_;

  /* Case table for case-conversion in this buffer.
     This char-table maps each char into its lower-case version.  */
  Lisp_Object downcase_table_;

  /* Char-table mapping each char to its upper-case version.  */
  Lisp_Object upcase_table_;

  /* Char-table for conversion for case-folding search.  */
  Lisp_Object case_canon_table_;

  /* Char-table of equivalences for case-folding search.  */
  Lisp_Object case_eqv_table_;

  /* Non-nil means do not display continuation lines.  */
  Lisp_Object truncate_lines_;

  /* Non-nil means to use word wrapping when displaying continuation lines.  */
  Lisp_Object word_wrap_;

  /* Non-nil means display ctl chars with uparrow.  */
  Lisp_Object ctl_arrow_;

  /* Non-nil means reorder bidirectional text for display in the
     visual order.  */
  Lisp_Object bidi_display_reordering_;

  /* If non-nil, specifies which direction of text to force in all the
     paragraphs of the buffer.  Nil means determine paragraph
     direction dynamically for each paragraph.  */
  Lisp_Object bidi_paragraph_direction_;

  /* If non-nil, a regular expression for bidi paragraph separator.  */
  Lisp_Object bidi_paragraph_separate_re_;

  /* If non-nil, a regular expression for bidi paragraph start.  */
  Lisp_Object bidi_paragraph_start_re_;

  /* Non-nil means do selective display;
     see doc string in syms_of_buffer (buffer.c) for details.  */
  Lisp_Object selective_display_;

  /* Non-nil means show ... at end of line followed by invisible lines.  */
  Lisp_Object selective_display_ellipses_;

  /* Alist of (FUNCTION . STRING) for each minor mode enabled in buffer.  */
  Lisp_Object minor_modes_;

  /* t if "self-insertion" should overwrite; `binary' if it should also
     overwrite newlines and tabs - for editing executables and the like.  */
  Lisp_Object overwrite_mode_;

  /* Non-nil means abbrev mode is on.  Expand abbrevs automatically.  */
  Lisp_Object abbrev_mode_;

  /* Display table to use for text in this buffer.  */
  Lisp_Object display_table_;

  /* t means the mark and region are currently active.  */
  Lisp_Object mark_active_;

  /* Non-nil means the buffer contents are regarded as multi-byte
     form of characters, not a binary code.  */
  Lisp_Object enable_multibyte_characters_;

  /* Coding system to be used for encoding the buffer contents on
     saving.  */
  Lisp_Object buffer_file_coding_system_;

  /* List of symbols naming the file format used for visited file.  */
  Lisp_Object file_format_;

  /* List of symbols naming the file format used for auto-save file.  */
  Lisp_Object auto_save_file_format_;

  /* True if the newline position cache, width run cache and BIDI paragraph
     cache are enabled.  See search.c, indent.c and bidi.c for details.  */
  Lisp_Object cache_long_scans_;

  /* If the width run cache is enabled, this table contains the
     character widths width_run_cache (see above) assumes.  When we
     do a thorough redisplay, we compare this against the buffer's
     current display table to see whether the display table has
     affected the widths of any characters.  If it has, we
     invalidate the width run cache, and re-initialize width_table.  */
  Lisp_Object width_table_;

  /* In an indirect buffer, or a buffer that is the base of an
     indirect buffer, this holds a marker that records
     PT for this buffer when the buffer is not current.  */
  Lisp_Object pt_marker_;

  /* In an indirect buffer, or a buffer that is the base of an
     indirect buffer, this holds a marker that records
     BEGV for this buffer when the buffer is not current.  */
  Lisp_Object begv_marker_;

  /* In an indirect buffer, or a buffer that is the base of an
     indirect buffer, this holds a marker that records
     ZV for this buffer when the buffer is not current.  */
  Lisp_Object zv_marker_;

  /* This holds the point value before the last scroll operation.
     Explicitly setting point sets this to nil.  */
  Lisp_Object point_before_scroll_;

  /* Truename of the visited file, or nil.  */
  Lisp_Object file_truename_;

  /* Invisibility spec of this buffer.
     t => any non-nil `invisible' property means invisible.
     A list => `invisible' property means invisible
     if it is memq in that list.  */
  Lisp_Object invisibility_spec_;

  /* This is the last window that was selected with this buffer in it,
     or nil if that window no longer displays this buffer.  */
  Lisp_Object last_selected_window_;

  /* Incremented each time the buffer is displayed in a window.  */
  Lisp_Object display_count_;

  /* Widths of left and right marginal areas for windows displaying
     this buffer.  */
  Lisp_Object left_margin_cols_;
  Lisp_Object right_margin_cols_;

  /* Widths of left and right fringe areas for windows displaying
     this buffer.  */
  Lisp_Object left_fringe_width_;
  Lisp_Object right_fringe_width_;

  /* Non-nil means fringes are drawn outside display margins;
     othersize draw them between margin areas and text.  */
  Lisp_Object fringes_outside_margins_;

  /* Width, height and types of scroll bar areas for windows displaying
     this buffer.  */
  Lisp_Object scroll_bar_width_;
  Lisp_Object scroll_bar_height_;
  Lisp_Object vertical_scroll_bar_type_;
  Lisp_Object horizontal_scroll_bar_type_;

  /* Non-nil means indicate lines not displaying text (in a style
     like vi).  */
  Lisp_Object indicate_empty_lines_;

  /* Non-nil means indicate buffer boundaries and scrolling.  */
  Lisp_Object indicate_buffer_boundaries_;

  /* Logical to physical fringe bitmap mappings.  */
  Lisp_Object fringe_indicator_alist_;

  /* Logical to physical cursor bitmap mappings.  */
  Lisp_Object fringe_cursor_alist_;

  /* Time stamp updated each time this buffer is displayed in a window.  */
  Lisp_Object display_time_;

  /* If scrolling the display because point is below the bottom of a
     window showing this buffer, try to choose a window start so
     that point ends up this number of lines from the top of the
     window.  Nil means that scrolling method isn't used.  */
  Lisp_Object scroll_up_aggressively_;

  /* If scrolling the display because point is above the top of a
     window showing this buffer, try to choose a window start so
     that point ends up this number of lines from the bottom of the
     window.  Nil means that scrolling method isn't used.  */
  Lisp_Object scroll_down_aggressively_;

  /* Desired cursor type in this buffer.  See the doc string of
     per-buffer variable `cursor-type'.  */
  Lisp_Object cursor_type_;

  /* An integer > 0 means put that number of pixels below text lines
     in the display of this buffer.  */
  Lisp_Object extra_line_spacing_;

  /* Cursor type to display in non-selected windows.
     t means to use hollow box cursor.
     See `cursor-type' for other values.  */
  Lisp_Object cursor_in_non_selected_windows_;

  /* No more Lisp_Object beyond cursor_in_non_selected_windows_.
     Except undo_list, which is handled specially in Fgarbage_collect.  */

  /* This structure holds the coordinates of the buffer contents
     in ordinary buffers.  In indirect buffers, this is not used.  */
  struct buffer_text own_text;

  /* This points to the `struct buffer_text' that used for this buffer.
     In an ordinary buffer, this is the own_text field above.
     In an indirect buffer, this is the own_text field of another buffer.  */
  struct buffer_text *text;

  /* Next buffer, in chain of all buffers, including killed ones.  */
  struct buffer *next;

  /* Char position of point in buffer.  */
  ptrdiff_t pt;

  /* Byte position of point in buffer.  */
  ptrdiff_t pt_byte;

  /* Char position of beginning of accessible range.  */
  ptrdiff_t begv;

  /* Byte position of beginning of accessible range.  */
  ptrdiff_t begv_byte;

  /* Char position of end of accessible range.  */
  ptrdiff_t zv;

  /* Byte position of end of accessible range.  */
  ptrdiff_t zv_byte;

  /* In an indirect buffer, this points to the base buffer.
     In an ordinary buffer, it is 0.  */
  struct buffer *base_buffer;

  /* In an indirect buffer, this is -1.  In an ordinary buffer,
     it's the number of indirect buffers that share our text;
     zero means that we're the only owner of this text.  */
  int indirections;

  /* Number of windows showing this buffer.  Always -1 for
     an indirect buffer since it counts as its base buffer.  */
  int window_count;

  /* A non-zero value in slot IDX means that per-buffer variable
     with index IDX has a local value in this buffer.  The index IDX
     for a buffer-local variable is stored in that variable's slot
     in buffer_local_flags as a Lisp integer.  If the index is -1,
     this means the variable is always local in all buffers.  */
#define MAX_PER_BUFFER_VARS 50
  char local_flags[MAX_PER_BUFFER_VARS];

  /* Set to the modtime of the visited file when read or written.
     modtime.tv_nsec == NONEXISTENT_MODTIME_NSECS means
     visited file was nonexistent.  modtime.tv_nsec ==
     UNKNOWN_MODTIME_NSECS means visited file modtime unknown;
     in no case complain about any mismatch on next save attempt.  */
#define NONEXISTENT_MODTIME_NSECS (-1)
#define UNKNOWN_MODTIME_NSECS (-2)
  struct timespec modtime;

  /* Size of the file when modtime was set.  This is used to detect the
     case where the file grew while we were reading it, so the modtime
     is still the same (since it's rounded up to seconds) but we're actually
     not up-to-date.  -1 means the size is unknown.  Only meaningful if
     modtime is actually set.  */
  off_t modtime_size;

  /* The value of text->modiff at the last auto-save.  */
  modiff_count auto_save_modified;

  /* The value of text->modiff at the last display error.
     Redisplay of this buffer is inhibited until it changes again.  */
  modiff_count display_error_modiff;

  /* The time at which we detected a failure to auto-save,
     Or 0 if we didn't have a failure.  */
  time_t auto_save_failure_time;

  /* Position in buffer at which display started
     the last time this buffer was displayed.  */
  ptrdiff_t last_window_start;

  /* If the long line scan cache is enabled (i.e. the buffer-local
     variable cache-long-line-scans is non-nil), newline_cache
     points to the newline cache, and width_run_cache points to the
     width run cache.

     The newline cache records which stretches of the buffer are
     known *not* to contain newlines, so that they can be skipped
     quickly when we search for newlines.

     The width run cache records which stretches of the buffer are
     known to contain characters whose widths are all the same.  If
     the width run cache maps a character to a value > 0, that value is
     the character's width; if it maps a character to zero, we don't
     know what its width is.  This allows compute_motion to process
     such regions very quickly, using algebra instead of inspecting
     each character.   See also width_table, below.

     The latter cache is used to speedup bidi_find_paragraph_start.  */
  struct region_cache *newline_cache;
  struct region_cache *width_run_cache;
  struct region_cache *bidi_paragraph_cache;

  /* Non-zero means disable redisplay optimizations when rebuilding the glyph
     matrices (but not when redrawing).  */
  bool_bf prevent_redisplay_optimizations_p : 1;

  /* Non-zero whenever the narrowing is changed in this buffer.  */
  bool_bf clip_changed : 1;

  /* Non-zero for internally used temporary buffers that don't need to
     run hooks kill-buffer-hook, buffer-list-update-hook, and
     kill-buffer-query-functions.  This is used in coding.c to avoid
     slowing down en/decoding when there are a lot of these hooks
     defined.  */
  bool_bf inhibit_buffer_hooks : 1;

  /* List of overlays that end at or before the current center,
     in order of end-position.  */
  struct Lisp_Overlay *overlays_before;

  /* List of overlays that end after  the current center,
     in order of start-position.  */
  struct Lisp_Overlay *overlays_after;

  /* Position where the overlay lists are centered.  */
  ptrdiff_t overlay_center;

  /* Changes in the buffer are recorded here for undo, and t means
     don't record anything.  This information belongs to the base
     buffer of an indirect buffer.  But we can't store it in the
     struct buffer_text because local variables have to be right in
     the struct buffer. So we copy it around in set_buffer_internal.  */
  Lisp_Object undo_list_;
};

INLINE bool
BUFFERP (Lisp_Object a)
{
  return PSEUDOVECTORP (a, PVEC_BUFFER);
}

INLINE void
CHECK_BUFFER (Lisp_Object x)
{
  CHECK_TYPE (BUFFERP (x), Qbufferp, x);
}

INLINE struct buffer *
XBUFFER (Lisp_Object a)
{
  eassert (BUFFERP (a));
  return XUNTAG (a, Lisp_Vectorlike, struct buffer);
}

/* Most code should use these functions to set Lisp fields in struct
   buffer.  (Some setters that are private to a single .c file are
   defined as static in those files.)  */
INLINE void
bset_bidi_paragraph_direction (struct buffer *b, Lisp_Object val)
{
  b->bidi_paragraph_direction_ = val;
}
INLINE void
bset_cache_long_scans (struct buffer *b, Lisp_Object val)
{
  b->cache_long_scans_ = val;
}
INLINE void
bset_case_canon_table (struct buffer *b, Lisp_Object val)
{
  b->case_canon_table_ = val;
}
INLINE void
bset_case_eqv_table (struct buffer *b, Lisp_Object val)
{
  b->case_eqv_table_ = val;
}
INLINE void
bset_directory (struct buffer *b, Lisp_Object val)
{
  b->directory_ = val;
}
INLINE void
bset_display_count (struct buffer *b, Lisp_Object val)
{
  b->display_count_ = val;
}
INLINE void
bset_left_margin_cols (struct buffer *b, Lisp_Object val)
{
  b->left_margin_cols_ = val;
}
INLINE void
bset_right_margin_cols (struct buffer *b, Lisp_Object val)
{
  b->right_margin_cols_ = val;
}
INLINE void
bset_display_time (struct buffer *b, Lisp_Object val)
{
  b->display_time_ = val;
}
INLINE void
bset_downcase_table (struct buffer *b, Lisp_Object val)
{
  b->downcase_table_ = val;
}
INLINE void
bset_enable_multibyte_characters (struct buffer *b, Lisp_Object val)
{
  b->enable_multibyte_characters_ = val;
}
INLINE void
bset_filename (struct buffer *b, Lisp_Object val)
{
  b->filename_ = val;
}
INLINE void
bset_keymap (struct buffer *b, Lisp_Object val)
{
  b->keymap_ = val;
}
INLINE void
bset_last_selected_window (struct buffer *b, Lisp_Object val)
{
  b->last_selected_window_ = val;
}
INLINE void
bset_local_var_alist (struct buffer *b, Lisp_Object val)
{
  b->local_var_alist_ = val;
}
INLINE void
bset_mark_active (struct buffer *b, Lisp_Object val)
{
  b->mark_active_ = val;
}
INLINE void
bset_point_before_scroll (struct buffer *b, Lisp_Object val)
{
  b->point_before_scroll_ = val;
}
INLINE void
bset_read_only (struct buffer *b, Lisp_Object val)
{
  b->read_only_ = val;
}
INLINE void
bset_truncate_lines (struct buffer *b, Lisp_Object val)
{
  b->truncate_lines_ = val;
}
INLINE void
bset_undo_list (struct buffer *b, Lisp_Object val)
{
  b->undo_list_ = val;
}
INLINE void
bset_upcase_table (struct buffer *b, Lisp_Object val)
{
  b->upcase_table_ = val;
}
INLINE void
bset_width_table (struct buffer *b, Lisp_Object val)
{
  b->width_table_ = val;
}

/* Number of Lisp_Objects at the beginning of struct buffer.
   If you add, remove, or reorder Lisp_Objects within buffer
   structure, make sure that this is still correct.  */

#define BUFFER_LISP_SIZE						\
  PSEUDOVECSIZE (struct buffer, cursor_in_non_selected_windows_)

/* Allocated size of the struct buffer part beyond leading
   Lisp_Objects, in word_size units.  */

#define BUFFER_REST_SIZE (VECSIZE (struct buffer) - BUFFER_LISP_SIZE)

/* Initialize the pseudovector header of buffer object.  BUFFER_LISP_SIZE
   is required for GC, but BUFFER_REST_SIZE is set up just to be consistent
   with other pseudovectors.  */

#define BUFFER_PVEC_INIT(b)                                    \
  XSETPVECTYPESIZE (b, PVEC_BUFFER, BUFFER_LISP_SIZE, BUFFER_REST_SIZE)

/* Convenient check whether buffer B is live.  */

#define BUFFER_LIVE_P(b) (!NILP (BVAR (b, name)))

/* Convenient check whether buffer B is hidden (i.e. its name
   starts with a space).  Caller must ensure that B is live.  */

#define BUFFER_HIDDEN_P(b) (SREF (BVAR (b, name), 0) == ' ')

/* Verify indirection counters.  */

#define BUFFER_CHECK_INDIRECTION(b)			\
  do {							\
    if (BUFFER_LIVE_P (b))				\
      {							\
	if (b->base_buffer)				\
	  {						\
	    eassert (b->indirections == -1);		\
	    eassert (b->base_buffer->indirections > 0);	\
	  }						\
	else						\
	  eassert (b->indirections >= 0);		\
      }							\
  } while (false)

/* Chain of all buffers, including killed ones.  */

extern struct buffer *all_buffers;

/* Used to iterate over the chain above.  */

#define FOR_EACH_BUFFER(b) \
  for ((b) = all_buffers; (b); (b) = (b)->next)

/* This structure holds the default values of the buffer-local variables
   that have special slots in each buffer.
   The default value occupies the same slot in this structure
   as an individual buffer's value occupies in that buffer.
   Setting the default value also goes through the alist of buffers
   and stores into each buffer that does not say it has a local value.  */

extern struct buffer buffer_defaults;

/* This structure marks which slots in a buffer have corresponding
   default values in buffer_defaults.
   Each such slot has a nonzero value in this structure.
   The value has only one nonzero bit.

   When a buffer has its own local value for a slot,
   the entry for that slot (found in the same slot in this structure)
   is turned on in the buffer's local_flags array.

   If a slot in this structure is zero, then even though there may
   be a Lisp-level local variable for the slot, it has no default value,
   and the corresponding slot in buffer_defaults is not used.  */


extern struct buffer buffer_local_flags;

/* For each buffer slot, this points to the Lisp symbol name
   for that slot in the current buffer.  It is 0 for slots
   that don't have such names.  */

extern struct buffer buffer_local_symbols;
\f
extern void delete_all_overlays (struct buffer *);
extern void reset_buffer (struct buffer *);
extern void compact_buffer (struct buffer *);
extern void evaporate_overlays (ptrdiff_t);
extern ptrdiff_t overlays_at (EMACS_INT, bool, Lisp_Object **,
			      ptrdiff_t *, ptrdiff_t *, ptrdiff_t *, bool);
extern ptrdiff_t sort_overlays (Lisp_Object *, ptrdiff_t, struct window *);
extern void recenter_overlay_lists (struct buffer *, ptrdiff_t);
extern ptrdiff_t overlay_strings (ptrdiff_t, struct window *, unsigned char **);
extern void validate_region (Lisp_Object *, Lisp_Object *);
extern void set_buffer_internal_1 (struct buffer *);
extern void set_buffer_internal_2 (struct buffer *);
extern void set_buffer_temp (struct buffer *);
extern Lisp_Object buffer_local_value (Lisp_Object, Lisp_Object);
extern void record_buffer (Lisp_Object);
extern void fix_overlays_before (struct buffer *, ptrdiff_t, ptrdiff_t);
extern void mmap_set_vars (bool);
extern void restore_buffer (Lisp_Object);
extern void set_buffer_if_live (Lisp_Object);

/* Return B as a struct buffer pointer, defaulting to the current buffer.  */

INLINE struct buffer *
decode_buffer (Lisp_Object b)
{
  return NILP (b) ? current_buffer : (CHECK_BUFFER (b), XBUFFER (b));
}

/* Set the current buffer to B.

   We previously set windows_or_buffers_changed here to invalidate
   global unchanged information in beg_unchanged and end_unchanged.
   This is no longer necessary because we now compute unchanged
   information on a buffer-basis.  Every action affecting other
   windows than the selected one requires a select_window at some
   time, and that increments windows_or_buffers_changed.  */

INLINE void
set_buffer_internal (struct buffer *b)
{
  if (current_buffer != b)
    set_buffer_internal_1 (b);
}

/* Arrange to go back to the original buffer after the next
   call to unbind_to if the original buffer is still alive.  */

INLINE void
record_unwind_current_buffer (void)
{
  record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ());
}

/* Get overlays at POSN into array OVERLAYS with NOVERLAYS elements.
   If NEXTP is non-NULL, return next overlay there.
   See overlay_at arg CHANGE_REQ for meaning of CHRQ arg.  */

#define GET_OVERLAYS_AT(posn, overlays, noverlays, nextp, chrq)		\
  do {									\
    ptrdiff_t maxlen = 40;						\
    SAFE_NALLOCA (overlays, 1, maxlen);					\
    (noverlays) = overlays_at (posn, false, &(overlays), &maxlen,	\
			       nextp, NULL, chrq);			\
    if ((noverlays) > maxlen)						\
      {									\
	maxlen = noverlays;						\
	SAFE_NALLOCA (overlays, 1, maxlen);				\
	(noverlays) = overlays_at (posn, false, &(overlays), &maxlen,	\
				   nextp, NULL, chrq);			\
      }									\
  } while (false)

extern Lisp_Object Vbuffer_alist;

/* FOR_EACH_LIVE_BUFFER (LIST_VAR, BUF_VAR) followed by a statement is
   a `for' loop which iterates over the buffers from Vbuffer_alist.  */

#define FOR_EACH_LIVE_BUFFER(list_var, buf_var)			\
  FOR_EACH_ALIST_VALUE (Vbuffer_alist, list_var, buf_var)

/* Get text properties of B.  */

INLINE INTERVAL
buffer_intervals (struct buffer *b)
{
  eassert (b->text != NULL);
  return b->text->intervals;
}

/* Set text properties of B to I.  */

INLINE void
set_buffer_intervals (struct buffer *b, INTERVAL i)
{
  eassert (b->text != NULL);
  b->text->intervals = i;
}

/* Non-zero if current buffer has overlays.  */

INLINE bool
buffer_has_overlays (void)
{
  return current_buffer->overlays_before || current_buffer->overlays_after;
}

/* Return character code of multi-byte form at byte position POS.  If POS
   doesn't point the head of valid multi-byte form, only the byte at
   POS is returned.  No range checking.  */

INLINE int
FETCH_MULTIBYTE_CHAR (ptrdiff_t pos)
{
  unsigned char *p = BYTE_POS_ADDR (pos);
  return STRING_CHAR (p);
}

/* Return character code of multi-byte form at byte position POS in BUF.
   If POS doesn't point the head of valid multi-byte form, only the byte at
   POS is returned.  No range checking.  */

INLINE int
BUF_FETCH_MULTIBYTE_CHAR (struct buffer *buf, ptrdiff_t pos)
{
  unsigned char *p
    = ((pos >= BUF_GPT_BYTE (buf) ? BUF_GAP_SIZE (buf) : 0)
       + pos + BUF_BEG_ADDR (buf) - BEG_BYTE);
  return STRING_CHAR (p);
}

/* Return number of windows showing B.  */

INLINE int
buffer_window_count (struct buffer *b)
{
  if (b->base_buffer)
    b = b->base_buffer;
  eassert (b->window_count >= 0);
  return b->window_count;
}

/* Overlays */

/* Return the marker that stands for where OV starts in the buffer.  */

#define OVERLAY_START(OV) XOVERLAY (OV)->start

/* Return the marker that stands for where OV ends in the buffer.  */

#define OVERLAY_END(OV) XOVERLAY (OV)->end

/* Return the plist of overlay OV.  */

#define OVERLAY_PLIST(OV) XOVERLAY (OV)->plist

/* Return the actual buffer position for the marker P.
   We assume you know which buffer it's pointing into.  */

#define OVERLAY_POSITION(P) \
 (MARKERP (P) ? marker_position (P) : (emacs_abort (), 0))

\f
/***********************************************************************
			Buffer-local Variables
 ***********************************************************************/

/* Number of per-buffer variables used.  */

extern int last_per_buffer_idx;

/* Return the offset in bytes of member VAR of struct buffer
   from the start of a buffer structure.  */

#define PER_BUFFER_VAR_OFFSET(VAR) \
  offsetof (struct buffer, VAR ## _)

/* Used to iterate over normal Lisp_Object fields of struct buffer (all
   Lisp_Objects except undo_list).  If you add, remove, or reorder
   Lisp_Objects in a struct buffer, make sure that this is still correct.  */

#define FOR_EACH_PER_BUFFER_OBJECT_AT(offset)				 \
  for (offset = PER_BUFFER_VAR_OFFSET (name);				 \
       offset <= PER_BUFFER_VAR_OFFSET (cursor_in_non_selected_windows); \
       offset += word_size)

/* Return the index of buffer-local variable VAR.  Each per-buffer
   variable has an index > 0 associated with it, except when it always
   has buffer-local values, in which case the index is -1.  If this is
   0, this is a bug and means that the slot of VAR in
   buffer_local_flags wasn't initialized.  */

#define PER_BUFFER_VAR_IDX(VAR) \
    PER_BUFFER_IDX (PER_BUFFER_VAR_OFFSET (VAR))

/* Value is true if the variable with index IDX has a local value
   in buffer B.  */

#define PER_BUFFER_VALUE_P(B, IDX)		\
    (((IDX) < 0 || IDX >= last_per_buffer_idx)	\
     ? (emacs_abort (), false)			\
     : ((B)->local_flags[IDX] != 0))

/* Set whether per-buffer variable with index IDX has a buffer-local
   value in buffer B.  VAL zero means it hasn't.  */

#define SET_PER_BUFFER_VALUE_P(B, IDX, VAL)	\
     do {						\
       if ((IDX) < 0 || (IDX) >= last_per_buffer_idx)	\
	 emacs_abort ();				\
       (B)->local_flags[IDX] = (VAL);			\
     } while (false)

/* Return the index value of the per-buffer variable at offset OFFSET
   in the buffer structure.

   If the slot OFFSET has a corresponding default value in
   buffer_defaults, the index value is positive and has only one
   nonzero bit.  When a buffer has its own local value for a slot, the
   bit for that slot (found in the same slot in this structure) is
   turned on in the buffer's local_flags array.

   If the index value is -1, even though there may be a
   DEFVAR_PER_BUFFER for the slot, there is no default value for it;
   and the corresponding slot in buffer_defaults is not used.

   If the index value is -2, then there is no DEFVAR_PER_BUFFER for
   the slot, but there is a default value which is copied into each
   new buffer.

   If a slot in this structure corresponding to a DEFVAR_PER_BUFFER is
   zero, that is a bug */


#define PER_BUFFER_IDX(OFFSET) \
      XFIXNUM (*(Lisp_Object *)((OFFSET) + (char *) &buffer_local_flags))

/* Functions to get and set default value of the per-buffer
   variable at offset OFFSET in the buffer structure.  */

INLINE Lisp_Object
per_buffer_default (int offset)
{
  return *(Lisp_Object *)(offset + (char *) &buffer_defaults);
}

INLINE void
set_per_buffer_default (int offset, Lisp_Object value)
{
  *(Lisp_Object *)(offset + (char *) &buffer_defaults) = value;
}

/* Functions to get and set buffer-local value of the per-buffer
   variable at offset OFFSET in the buffer structure.  */

INLINE Lisp_Object
per_buffer_value (struct buffer *b, int offset)
{
  return *(Lisp_Object *)(offset + (char *) b);
}

INLINE void
set_per_buffer_value (struct buffer *b, int offset, Lisp_Object value)
{
  *(Lisp_Object *)(offset + (char *) b) = value;
}

/* Downcase a character C, or make no change if that cannot be done.  */
INLINE int
downcase (int c)
{
  Lisp_Object downcase_table = BVAR (current_buffer, downcase_table);
  Lisp_Object down = CHAR_TABLE_REF (downcase_table, c);
  return FIXNATP (down) ? XFIXNAT (down) : c;
}

/* Upcase a character C, or make no change if that cannot be done. */
INLINE int
upcase (int c)
{
  Lisp_Object upcase_table = BVAR (current_buffer, upcase_table);
  Lisp_Object up = CHAR_TABLE_REF (upcase_table, c);
  return FIXNATP (up) ? XFIXNAT (up) : c;
}

/* True if C is upper case.  */
INLINE bool
uppercasep (int c)
{
  return downcase (c) != c;
}

/* True if C is lower case.  */
INLINE bool
lowercasep (int c)
{
  return !uppercasep (c) && upcase (c) != c;
}

INLINE_HEADER_END

#endif /* EMACS_BUFFER_H */

debug log:

solving f42c3e97b9 ...
found f42c3e97b9 in https://git.savannah.gnu.org/cgit/emacs.git

(*) Git path names are given by the tree(s) the blob belongs to.
    Blobs themselves have no identifier aside from the hash of its contents.^

Code repositories for project(s) associated with this public inbox

	https://git.savannah.gnu.org/cgit/emacs.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).