This file is indexed.

/usr/share/ada/adainclude/gnatprj/styleg.adb is in libgnatprj4.9-dev 4.9.3-3ubuntu5.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

   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
------------------------------------------------------------------------------
--                                                                          --
--                         GNAT COMPILER COMPONENTS                         --
--                                                                          --
--                               S T Y L E G                                --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--          Copyright (C) 1992-2013, Free Software Foundation, Inc.         --
--                                                                          --
-- GNAT is free software;  you can  redistribute it  and/or modify it under --
-- terms of the  GNU General Public License as published  by the Free Soft- --
-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT 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  distributed with GNAT; see file COPYING3.  If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license.          --
--                                                                          --
-- GNAT was originally developed  by the GNAT team at  New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc.      --
--                                                                          --
------------------------------------------------------------------------------

--  This version of the Style package implements the standard GNAT style
--  checking rules. For documentation of these rules, see comments on the
--  individual procedures.

with Atree;    use Atree;
with Casing;   use Casing;
with Csets;    use Csets;
with Einfo;    use Einfo;
with Err_Vars; use Err_Vars;
with Opt;      use Opt;
with Scans;    use Scans;
with Sinfo;    use Sinfo;
with Sinput;   use Sinput;
with Stylesw;  use Stylesw;

package body Styleg is

   use ASCII;

   Blank_Lines : Nat := 0;
   --  Counts number of empty lines seen. Reset to zero if a non-empty line
   --  is encountered. Used to check for trailing blank lines in Check_EOF,
   --  and for multiple blank lines.

   Blank_Line_Location : Source_Ptr;
   --  Remembers location of first blank line in a series. Used to issue an
   --  appropriate diagnostic if subsequent blank lines or the end of file
   --  is encountered.

   -----------------------
   -- Local Subprograms --
   -----------------------

   procedure Check_No_Space_After;
   --  Checks that there is a non-white space character after the current
   --  token, or white space followed by a comment, or the end of line.
   --  Issue error message if not.

   procedure Check_No_Space_Before;
   --  Check that token is first token on line, or else is not preceded
   --  by white space. Signal error of space not allowed if not.

   procedure Check_Separate_Stmt_Lines_Cont;
   --  Non-inlined continuation of Check_Separate_Stmt_Lines

   function Determine_Token_Casing return Casing_Type;
   --  Determine casing of current token

   procedure Error_Space_Not_Allowed (S : Source_Ptr);
   --  Posts an error message indicating that a space is not allowed
   --  at the given source location.

   procedure Error_Space_Required (S : Source_Ptr);
   --  Posts an error message indicating that a space is required at
   --  the given source location.

   function Is_White_Space (C : Character) return Boolean;
   pragma Inline (Is_White_Space);
   --  Returns True for space or HT, False otherwise
   --  What about VT and FF, should they return True ???

   procedure Require_Following_Space;
   pragma Inline (Require_Following_Space);
   --  Require token to be followed by white space. Used only if in GNAT
   --  style checking mode.

   procedure Require_Preceding_Space;
   pragma Inline (Require_Preceding_Space);
   --  Require token to be preceded by white space. Used only if in GNAT
   --  style checking mode.

   ----------------------
   -- Check_Abs_Or_Not --
   ----------------------

   --  In check token mode (-gnatyt), ABS/NOT must be followed by a space

   procedure Check_Abs_Not is
   begin
      if Style_Check_Tokens then
         if Source (Scan_Ptr) > ' ' then -- ???
            Error_Space_Required (Scan_Ptr);
         end if;
      end if;
   end Check_Abs_Not;

   ----------------------
   -- Check_Apostrophe --
   ----------------------

   --  Do not allow space before or after apostrophe -- OR AFTER???

   procedure Check_Apostrophe is
   begin
      if Style_Check_Tokens then
         Check_No_Space_After;
      end if;
   end Check_Apostrophe;

   -----------------
   -- Check_Arrow --
   -----------------

   --  In check tokens mode (-gnatys), arrow must be surrounded by spaces

   procedure Check_Arrow is
   begin
      if Style_Check_Tokens then
         Require_Preceding_Space;
         Require_Following_Space;
      end if;
   end Check_Arrow;

   --------------------------
   -- Check_Attribute_Name --
   --------------------------

   --  In check attribute casing mode (-gnatya), attribute names must be
   --  mixed case, i.e. start with an upper case letter, and otherwise
   --  lower case, except after an underline character.

   procedure Check_Attribute_Name (Reserved : Boolean) is
      pragma Warnings (Off, Reserved);
   begin
      if Style_Check_Attribute_Casing then
         if Determine_Token_Casing /= Mixed_Case then
            Error_Msg_SC -- CODEFIX
              ("(style) bad capitalization, mixed case required");
         end if;
      end if;
   end Check_Attribute_Name;

   ---------------------------
   -- Check_Binary_Operator --
   ---------------------------

   --  In check token mode (-gnatyt), binary operators other than the special
   --  case of exponentiation require surrounding space characters.

   procedure Check_Binary_Operator is
   begin
      if Style_Check_Tokens then
         Require_Preceding_Space;
         Require_Following_Space;
      end if;
   end Check_Binary_Operator;

   ----------------------------
   -- Check_Boolean_Operator --
   ----------------------------

   procedure Check_Boolean_Operator (Node : Node_Id) is

      function OK_Boolean_Operand (N : Node_Id) return Boolean;
      --  Returns True for simple variable, or "not X1" or "X1 and X2" or
      --  "X1 or X2" where X1, X2 are recursively OK_Boolean_Operand's.

      ------------------------
      -- OK_Boolean_Operand --
      ------------------------

      function OK_Boolean_Operand (N : Node_Id) return Boolean is
      begin
         if Nkind_In (N, N_Identifier, N_Expanded_Name) then
            return True;

         elsif Nkind (N) = N_Op_Not then
            return OK_Boolean_Operand (Original_Node (Right_Opnd (N)));

         elsif Nkind_In (N, N_Op_And, N_Op_Or) then
            return OK_Boolean_Operand (Original_Node (Left_Opnd (N)))
                     and then
                   OK_Boolean_Operand (Original_Node (Right_Opnd (N)));

         else
            return False;
         end if;
      end OK_Boolean_Operand;

   --  Start of processing for Check_Boolean_Operator

   begin
      if Style_Check_Boolean_And_Or
        and then Comes_From_Source (Node)
      then
         declare
            Orig : constant Node_Id := Original_Node (Node);

         begin
            if Nkind_In (Orig, N_Op_And, N_Op_Or) then
               declare
                  L : constant Node_Id := Original_Node (Left_Opnd  (Orig));
                  R : constant Node_Id := Original_Node (Right_Opnd (Orig));

               begin
                  --  First OK case, simple boolean constants/identifiers

                  if OK_Boolean_Operand (L)
                       and then
                     OK_Boolean_Operand (R)
                  then
                     return;

                  --  Second OK case, modular types

                  elsif Is_Modular_Integer_Type (Etype (Node)) then
                     return;

                  --  Third OK case, array types

                  elsif Is_Array_Type (Etype (Node)) then
                     return;

                  --  Otherwise we have an error

                  elsif Nkind (Orig) = N_Op_And then
                     Error_Msg -- CODEFIX
                       ("(style) `AND THEN` required", Sloc (Orig));
                  else
                     Error_Msg -- CODEFIX
                       ("(style) `OR ELSE` required", Sloc (Orig));
                  end if;
               end;
            end if;
         end;
      end if;
   end Check_Boolean_Operator;

   ---------------
   -- Check_Box --
   ---------------

   --  In check token mode (-gnatyt), box must be preceded by a space or by
   --  a left parenthesis. Spacing checking on the surrounding tokens takes
   --  care of the remaining checks.

   procedure Check_Box is
   begin
      if Style_Check_Tokens then
         if Prev_Token /= Tok_Left_Paren then
            Require_Preceding_Space;
         end if;
      end if;
   end Check_Box;

   -----------------
   -- Check_Colon --
   -----------------

   --  In check token mode (-gnatyt), colon must be surrounded by spaces

   procedure Check_Colon is
   begin
      if Style_Check_Tokens then
         Require_Preceding_Space;
         Require_Following_Space;
      end if;
   end Check_Colon;

   -----------------------
   -- Check_Colon_Equal --
   -----------------------

   --  In check token mode (-gnatyt), := must be surrounded by spaces

   procedure Check_Colon_Equal is
   begin
      if Style_Check_Tokens then
         Require_Preceding_Space;
         Require_Following_Space;
      end if;
   end Check_Colon_Equal;

   -----------------
   -- Check_Comma --
   -----------------

   --  In check token mode (-gnatyt), comma must be either the first
   --  token on a line, or be preceded by a non-blank character.
   --  It must also always be followed by a blank.

   procedure Check_Comma is
   begin
      if Style_Check_Tokens then
         Check_No_Space_Before;

         if Source (Scan_Ptr) > ' ' then
            Error_Space_Required (Scan_Ptr);
         end if;
      end if;
   end Check_Comma;

   -------------------
   -- Check_Comment --
   -------------------

   --  In check comment mode (-gnatyc) there are several requirements on the
   --  format of comments. The following are permissible comment formats:

   --    1. Any comment that is not at the start of a line, i.e. where the
   --       initial minuses are not the first non-blank characters on the
   --       line must have at least one blank after the second minus or a
   --       special character as defined in rule 5.

   --    2. A row of all minuses of any length is permitted (see procedure
   --       box above in the source of this routine).

   --    3. A comment line starting with two minuses and a space, and ending
   --       with a space and two minuses. Again see the procedure title box
   --       immediately above in the source.

   --    4. A full line comment where two spaces follow the two minus signs.
   --       This is the normal comment format in GNAT style, as typified by
   --       the comments you are reading now.

   --    5. A full line comment where the first character after the second
   --       minus is a special character, i.e. a character in the ASCII
   --       range 16#21#..16#2F# or 16#3A#..16#3F#. This allows special
   --       comments, such as those generated by gnatprep, or those that
   --       appear in the SPARK annotation language to be accepted.

   --       Note: for GNAT internal files (-gnatg switch set on for the
   --       compilation), the only special sequence recognized and allowed
   --       is --! as generated by gnatprep.

   --    6. In addition, the comment must be properly indented if comment
   --       indentation checking is active (Style_Check_Indentation non-zero).
   --       Either the start column must be a multiple of this indentation,
   --       or the indentation must match that of the next non-blank line,
   --       or must match the indentation of the immediately preciding line
   --       if it is non-blank.

   procedure Check_Comment is
      S : Source_Ptr;
      C : Character;

      function Is_Box_Comment return Boolean;
      --  Returns True if the last two characters on the line are -- which
      --  characterizes a box comment (as for example follows this spec).

      function Is_Special_Character (C : Character) return Boolean;
      --  Determines if C is a special character (see rule 5 above)

      function Same_Column_As_Next_Non_Blank_Line return Boolean;
      --  Called for a full line comment. If the indentation of this comment
      --  matches that of the next non-blank line in the source, then True is
      --  returned, otherwise False.

      function Same_Column_As_Previous_Line return Boolean;
      --  Called for a full line comment. If the previous line is blank, then
      --  returns False. Otherwise, if the indentation of this comment matches
      --  that of the previous line in the source, then True is returned,
      --  otherwise False.

      --------------------
      -- Is_Box_Comment --
      --------------------

      function Is_Box_Comment return Boolean is
         S : Source_Ptr;

      begin
         --  Do we need to worry about UTF_32 line terminators here ???

         S := Scan_Ptr + 3;
         while Source (S) not in Line_Terminator loop
            S := S + 1;
         end loop;

         return Source (S - 1) = '-' and then Source (S - 2) = '-';
      end Is_Box_Comment;

      --------------------------
      -- Is_Special_Character --
      --------------------------

      function Is_Special_Character (C : Character) return Boolean is
      begin
         if GNAT_Mode then
            return C = '!';
         else
            return
              Character'Pos (C) in 16#21# .. 16#2F#
                or else
              Character'Pos (C) in 16#3A# .. 16#3F#;
         end if;
      end Is_Special_Character;

      ----------------------------------------
      -- Same_Column_As_Next_Non_Blank_Line --
      ----------------------------------------

      function Same_Column_As_Next_Non_Blank_Line return Boolean is
         P : Source_Ptr;

      begin
         --  Step to end of line

         P := Scan_Ptr + 2;
         while Source (P) not in Line_Terminator loop
            P := P + 1;
         end loop;

         --  Step past blanks, and line terminators (UTF_32 case???)

         while Source (P) <= ' ' and then Source (P) /= EOF loop
            P := P + 1;
         end loop;

         --  Compare columns

         return Get_Column_Number (Scan_Ptr) = Get_Column_Number (P);
      end Same_Column_As_Next_Non_Blank_Line;

      ----------------------------------
      -- Same_Column_As_Previous_Line --
      ----------------------------------

      function Same_Column_As_Previous_Line return Boolean is
         S, P : Source_Ptr;

      begin
         --  Point S to start of this line, and P to start of previous line

         S := Line_Start (Scan_Ptr);
         P := S;
         Backup_Line (P);

         --  Step P to first non-blank character on line

         loop
            --  If we get back to start of current line, then the previous line
            --  was blank, and we always return False in that situation.

            if P = S then
               return False;
            end if;

            exit when Source (P) /= ' ' and then Source (P) /= ASCII.HT;
            P := P + 1;
         end loop;

         --  Compare columns

         return Get_Column_Number (Scan_Ptr) = Get_Column_Number (P);
      end Same_Column_As_Previous_Line;

   --  Start of processing for Check_Comment

   begin
      --  Can never have a non-blank character preceding the first minus

      if Style_Check_Comments then
         if Scan_Ptr > Source_First (Current_Source_File)
           and then Source (Scan_Ptr - 1) > ' '
         then
            Error_Msg_S -- CODEFIX
              ("(style) space required");
         end if;
      end if;

      --  For a comment that is not at the start of the line, the only
      --  requirement is that we cannot have a non-blank character after
      --  the second minus sign or a special character.

      if Scan_Ptr /= First_Non_Blank_Location then
         if Style_Check_Comments then
            if Source (Scan_Ptr + 2) > ' '
              and then not Is_Special_Character (Source (Scan_Ptr + 2))
            then
               Error_Msg -- CODEFIX
                 ("(style) space required", Scan_Ptr + 2);
            end if;
         end if;

         return;

      --  Case of a comment that is at the start of a line

      else
         --  First check, must be in appropriately indented column

         if Style_Check_Indentation /= 0 then
            if Start_Column rem Style_Check_Indentation /= 0 then
               if not Same_Column_As_Next_Non_Blank_Line
                 and then not Same_Column_As_Previous_Line
               then
                  Error_Msg_S -- CODEFIX
                    ("(style) bad column");
               end if;

               return;
            end if;
         end if;

         --  If we are not checking comments, nothing more to do

         if not Style_Check_Comments then
            return;
         end if;

         --  Case of not followed by a blank. Usually wrong, but there are
         --  some exceptions that we permit.

         if Source (Scan_Ptr + 2) /= ' ' then
            C := Source (Scan_Ptr + 2);

            --  Case of -- all on its own on a line is OK

            if C < ' ' then
               return;
            end if;

            --  Case of --x, x special character is OK (gnatprep/SPARK/etc.)
            --  This is not permitted in internal GNAT implementation units
            --  except for the case of --! as used by gnatprep output.

            if Is_Special_Character (C) then
               return;
            end if;

            --  The only other case in which we allow a character after
            --  the -- other than a space is when we have a row of minus
            --  signs (case of header lines for a box comment for example).

            S := Scan_Ptr + 2;
            while Source (S) >= ' ' loop
               if Source (S) /= '-' then
                  if Is_Box_Comment
                    or else Style_Check_Comments_Spacing = 1
                  then
                     Error_Space_Required (Scan_Ptr + 2);
                  else
                     Error_Msg -- CODEFIX
                       ("(style) two spaces required", Scan_Ptr + 2);
                  end if;

                  return;
               end if;

               S := S + 1;
            end loop;

         --  If we are followed by a blank, then the comment is OK if the
         --  character following this blank is another blank or a format
         --  effector, or if the required comment spacing is 1.

         elsif Source (Scan_Ptr + 3) <= ' '
           or else Style_Check_Comments_Spacing = 1
         then
            return;

         --  Here is the case where we only have one blank after the two minus
         --  signs, with Style_Check_Comments_Spacing set to 2, which is an
         --  error unless the line ends with two minus signs, the case of a
         --  box comment.

         elsif not Is_Box_Comment then
            Error_Space_Required (Scan_Ptr + 3);
         end if;
      end if;
   end Check_Comment;

   -------------------
   -- Check_Dot_Dot --
   -------------------

   --  In check token mode (-gnatyt), ".." must be surrounded by spaces

   procedure Check_Dot_Dot is
   begin
      if Style_Check_Tokens then
         Require_Preceding_Space;
         Require_Following_Space;
      end if;
   end Check_Dot_Dot;

   ---------------
   -- Check_EOF --
   ---------------

   --  In check blanks at end mode, check no blank lines precede the EOF

   procedure Check_EOF is
   begin
      if Style_Check_Blank_Lines then

         --  We expect one blank line, from the EOF, but no more than one

         if Blank_Lines = 2 then
            Error_Msg -- CODEFIX
              ("(style) blank line not allowed at end of file",
               Blank_Line_Location);

         elsif Blank_Lines >= 3 then
            Error_Msg -- CODEFIX
              ("(style) blank lines not allowed at end of file",
               Blank_Line_Location);
         end if;
      end if;
   end Check_EOF;

   -----------------------------------
   -- Check_Exponentiation_Operator --
   -----------------------------------

   --  No spaces are required for the ** operator in GNAT style check mode

   procedure Check_Exponentiation_Operator is
   begin
      null;
   end Check_Exponentiation_Operator;

   --------------
   -- Check_HT --
   --------------

   --  In check horizontal tab mode (-gnatyh), tab characters are not allowed

   procedure Check_HT is
   begin
      if Style_Check_Horizontal_Tabs then
         Error_Msg_S -- CODEFIX
           ("(style) horizontal tab not allowed");
      end if;
   end Check_HT;

   -----------------------
   -- Check_Indentation --
   -----------------------

   --  In check indentation mode (-gnaty? for ? a digit), a new statement or
   --  declaration is required to start in a column that is a multiple of the
   --  indentation amount.

   procedure Check_Indentation is
   begin
      if Style_Check_Indentation /= 0 then
         if Token_Ptr = First_Non_Blank_Location
           and then Start_Column rem Style_Check_Indentation /= 0
         then
            Error_Msg_SC -- CODEFIX
              ("(style) bad indentation");
         end if;
      end if;
   end Check_Indentation;

   ----------------------
   -- Check_Left_Paren --
   ----------------------

   --  In check token mode (-gnatyt), left paren must not be preceded by an
   --  identifier character or digit (a separating space is required) and may
   --  never be followed by a space.

   procedure Check_Left_Paren is
   begin
      if Style_Check_Tokens then
         if Token_Ptr > Source_First (Current_Source_File)
           and then Identifier_Char (Source (Token_Ptr - 1))
         then
            Error_Space_Required (Token_Ptr);
         end if;

         Check_No_Space_After;
      end if;
   end Check_Left_Paren;

   ---------------------------
   -- Check_Line_Max_Length --
   ---------------------------

   --  In check max line length mode (-gnatym), the line length must
   --  not exceed the permitted maximum value.

   procedure Check_Line_Max_Length (Len : Int) is
   begin
      if Style_Check_Max_Line_Length then
         if Len > Style_Max_Line_Length then
            Error_Msg
              ("(style) this line is too long",
               Current_Line_Start + Source_Ptr (Style_Max_Line_Length));
         end if;
      end if;
   end Check_Line_Max_Length;

   ---------------------------
   -- Check_Line_Terminator --
   ---------------------------

   --  In check blanks at end mode (-gnatyb), lines may not end with a
   --  trailing space.

   --  In check form feeds mode (-gnatyf), the line terminator may not
   --  be either of the characters FF or VT.

   --  In check DOS line terminators node (-gnatyd), the line terminator
   --  must be a single LF, without a following CR.

   procedure Check_Line_Terminator (Len : Int) is
      S : Source_Ptr;

      L : Int := Len;
      --  Length of line (adjusted down for blanks at end of line)

   begin
      --  Reset count of blank lines if first line

      if Get_Logical_Line_Number (Scan_Ptr) = 1 then
         Blank_Lines := 0;
      end if;

      --  Check FF/VT terminators

      if Style_Check_Form_Feeds then
         if Source (Scan_Ptr) = ASCII.FF then
            Error_Msg_S -- CODEFIX
              ("(style) form feed not allowed");
         elsif Source (Scan_Ptr) = ASCII.VT then
            Error_Msg_S -- CODEFIX
              ("(style) vertical tab not allowed");
         end if;
      end if;

      --  Check DOS line terminator

      if Style_Check_DOS_Line_Terminator then

         --  Ignore EOF, since we only get called with an EOF if it is the last
         --  character in the buffer (and was therefore not in the source
         --  file), since the terminating EOF is added to stop the scan.

         if Source (Scan_Ptr) = EOF then
            null;

         --  Bad terminator if we don't have an LF

         elsif Source (Scan_Ptr) /= LF then
            Error_Msg_S ("(style) incorrect line terminator");
         end if;
      end if;

      --  Remove trailing spaces

      S := Scan_Ptr;
      while L > 0 and then Is_White_Space (Source (S - 1)) loop
         S := S - 1;
         L := L - 1;
      end loop;

      --  Issue message for blanks at end of line if option enabled

      if Style_Check_Blanks_At_End and then L < Len then
         Error_Msg -- CODEFIX
           ("(style) trailing spaces not permitted", S);
      end if;

      --  Deal with empty (blank) line

      if L = 0 then

         --  Increment blank line count

         Blank_Lines := Blank_Lines + 1;

         --  If first blank line, record location for later error message

         if Blank_Lines = 1 then
            Blank_Line_Location := Scan_Ptr;
         end if;

      --  Non-blank line, check for previous multiple blank lines

      else
         if Style_Check_Blank_Lines and then Blank_Lines > 1 then
            Error_Msg -- CODEFIX
              ("(style) multiple blank lines", Blank_Line_Location);
         end if;

         --  And reset blank line count

         Blank_Lines := 0;
      end if;
   end Check_Line_Terminator;

   ------------------
   -- Check_Not_In --
   ------------------

   --  In check tokens mode, only one space between NOT and IN

   procedure Check_Not_In is
   begin
      if Style_Check_Tokens then
         if Source (Token_Ptr - 1) /= ' '
           or else Token_Ptr - Prev_Token_Ptr /= 4
         then -- CODEFIX?
            Error_Msg
              ("(style) single space must separate NOT and IN", Token_Ptr - 1);
         end if;
      end if;
   end Check_Not_In;

   --------------------------
   -- Check_No_Space_After --
   --------------------------

   procedure Check_No_Space_After is
      S : Source_Ptr;

   begin
      if Is_White_Space (Source (Scan_Ptr)) then

         --  Allow one or more spaces if followed by comment

         S := Scan_Ptr + 1;
         loop
            if Source (S) = '-' and then Source (S + 1) = '-' then
               return;

            elsif Is_White_Space (Source (S)) then
               S := S + 1;

            else
               exit;
            end if;
         end loop;

         Error_Space_Not_Allowed (Scan_Ptr);
      end if;
   end Check_No_Space_After;

   ---------------------------
   -- Check_No_Space_Before --
   ---------------------------

   procedure Check_No_Space_Before is
   begin
      if Token_Ptr > First_Non_Blank_Location
         and then Source (Token_Ptr - 1) <= ' '
      then
         Error_Space_Not_Allowed (Token_Ptr - 1);
      end if;
   end Check_No_Space_Before;

   -----------------------
   -- Check_Pragma_Name --
   -----------------------

   --  In check pragma casing mode (-gnatyp), pragma names must be mixed
   --  case, i.e. start with an upper case letter, and otherwise lower case,
   --  except after an underline character.

   procedure Check_Pragma_Name is
   begin
      if Style_Check_Pragma_Casing then
         if Determine_Token_Casing /= Mixed_Case then
            Error_Msg_SC -- CODEFIX
              ("(style) bad capitalization, mixed case required");
         end if;
      end if;
   end Check_Pragma_Name;

   -----------------------
   -- Check_Right_Paren --
   -----------------------

   --  In check token mode (-gnatyt), right paren must not be immediately
   --  followed by an identifier character, and must never be preceded by
   --  a space unless it is the initial non-blank character on the line.

   procedure Check_Right_Paren is
   begin
      if Style_Check_Tokens then
         if Identifier_Char (Source (Token_Ptr + 1)) then
            Error_Space_Required (Token_Ptr + 1);
         end if;

         Check_No_Space_Before;
      end if;
   end Check_Right_Paren;

   ---------------------
   -- Check_Semicolon --
   ---------------------

   --  In check token mode (-gnatyt), semicolon does not permit a preceding
   --  space and a following space is required.

   procedure Check_Semicolon is
   begin
      if Style_Check_Tokens then
         Check_No_Space_Before;

         if Source (Scan_Ptr) > ' ' then
            Error_Space_Required (Scan_Ptr);
         end if;
      end if;
   end Check_Semicolon;

   -------------------------------
   -- Check_Separate_Stmt_Lines --
   -------------------------------

   procedure Check_Separate_Stmt_Lines is
   begin
      if Style_Check_Separate_Stmt_Lines then
         Check_Separate_Stmt_Lines_Cont;
      end if;
   end Check_Separate_Stmt_Lines;

   ------------------------------------
   -- Check_Separate_Stmt_Lines_Cont --
   ------------------------------------

   procedure Check_Separate_Stmt_Lines_Cont is
      S : Source_Ptr;

   begin
      --  Skip past white space

      S := Scan_Ptr;
      while Is_White_Space (Source (S)) loop
         S := S + 1;
      end loop;

      --  Line terminator is OK

      if Source (S) in Line_Terminator then
         return;

      --  Comment is OK

      elsif Source (S) = '-' and then Source (S + 1) = '-' then
         return;

      --  ABORT keyword is OK after THEN (THEN ABORT case)

      elsif Token = Tok_Then
        and then (Source (S + 0) = 'a' or else Source (S + 0) = 'A')
        and then (Source (S + 1) = 'b' or else Source (S + 1) = 'B')
        and then (Source (S + 2) = 'o' or else Source (S + 2) = 'O')
        and then (Source (S + 3) = 'r' or else Source (S + 3) = 'R')
        and then (Source (S + 4) = 't' or else Source (S + 4) = 'T')
        and then (Source (S + 5) in Line_Terminator
                   or else Is_White_Space (Source (S + 5)))
      then
         return;

      --  PRAGMA keyword is OK after ELSE

      elsif Token = Tok_Else
        and then (Source (S + 0) = 'p' or else Source (S + 0) = 'P')
        and then (Source (S + 1) = 'r' or else Source (S + 1) = 'R')
        and then (Source (S + 2) = 'a' or else Source (S + 2) = 'A')
        and then (Source (S + 3) = 'g' or else Source (S + 3) = 'G')
        and then (Source (S + 4) = 'm' or else Source (S + 4) = 'M')
        and then (Source (S + 5) = 'a' or else Source (S + 5) = 'A')
        and then (Source (S + 6) in Line_Terminator
                   or else Is_White_Space (Source (S + 6)))
      then
         return;

         --  Otherwise we have the style violation we are looking for

      else
         if Token = Tok_Then then
            Error_Msg -- CODEFIX
              ("(style) no statements may follow THEN on same line", S);
         else
            Error_Msg
              ("(style) no statements may follow ELSE on same line", S);
         end if;
      end if;
   end Check_Separate_Stmt_Lines_Cont;

   ----------------
   -- Check_Then --
   ----------------

   --  In check if then layout mode (-gnatyi), we expect a THEN keyword
   --  to appear either on the same line as the IF, or on a separate line
   --  if the IF statement extends for more than one line.

   procedure Check_Then (If_Loc : Source_Ptr) is
   begin
      if Style_Check_If_Then_Layout then
         declare
            If_Line   : constant Physical_Line_Number :=
              Get_Physical_Line_Number (If_Loc);
            Then_Line : constant Physical_Line_Number :=
              Get_Physical_Line_Number (Token_Ptr);
         begin
            if If_Line = Then_Line then
               null;
            elsif Token_Ptr /= First_Non_Blank_Location then
               Error_Msg_SC ("(style) misplaced THEN");
            end if;
         end;
      end if;
   end Check_Then;

   -------------------------------
   -- Check_Unary_Plus_Or_Minus --
   -------------------------------

   --  In check token mode (-gnatyt), unary plus or minus must not be
   --  followed by a space.

   procedure Check_Unary_Plus_Or_Minus is
   begin
      if Style_Check_Tokens then
         Check_No_Space_After;
      end if;
   end Check_Unary_Plus_Or_Minus;

   ------------------------
   -- Check_Vertical_Bar --
   ------------------------

   --  In check token mode (-gnatyt), vertical bar must be surrounded by spaces

   procedure Check_Vertical_Bar is
   begin
      if Style_Check_Tokens then
         Require_Preceding_Space;
         Require_Following_Space;
      end if;
   end Check_Vertical_Bar;

   -----------------------
   -- Check_Xtra_Parens --
   -----------------------

   procedure Check_Xtra_Parens (Loc : Source_Ptr) is
   begin
      if Style_Check_Xtra_Parens then
         Error_Msg -- CODEFIX
           ("redundant parentheses?", Loc);
      end if;
   end Check_Xtra_Parens;

   ----------------------------
   -- Determine_Token_Casing --
   ----------------------------

   function Determine_Token_Casing return Casing_Type is
   begin
      return Determine_Casing (Source (Token_Ptr .. Scan_Ptr - 1));
   end Determine_Token_Casing;

   -----------------------------
   -- Error_Space_Not_Allowed --
   -----------------------------

   procedure Error_Space_Not_Allowed (S : Source_Ptr) is
   begin
      Error_Msg -- CODEFIX
        ("(style) space not allowed", S);
   end Error_Space_Not_Allowed;

   --------------------------
   -- Error_Space_Required --
   --------------------------

   procedure Error_Space_Required (S : Source_Ptr) is
   begin
      Error_Msg -- CODEFIX
        ("(style) space required", S);
   end Error_Space_Required;

   --------------------
   -- Is_White_Space --
   --------------------

   function Is_White_Space (C : Character) return Boolean is
   begin
      return C = ' ' or else C = HT;
   end Is_White_Space;

   -------------------
   -- Mode_In_Check --
   -------------------

   function Mode_In_Check return Boolean is
   begin
      return Style_Check and Style_Check_Mode_In;
   end Mode_In_Check;

   -----------------
   -- No_End_Name --
   -----------------

   --  In check end/exit labels mode (-gnatye), always require the name of
   --  a subprogram or package to be present on the END, so this is an error.

   procedure No_End_Name (Name : Node_Id) is
   begin
      if Style_Check_End_Labels then
         Error_Msg_Node_1 := Name;
         Error_Msg_SP -- CODEFIX
           ("(style) `END &` required");
      end if;
   end No_End_Name;

   ------------------
   -- No_Exit_Name --
   ------------------

   --  In check end/exit labels mode (-gnatye), always require the name of
   --  the loop to be present on the EXIT when exiting a named loop.

   procedure No_Exit_Name (Name : Node_Id) is
   begin
      if Style_Check_End_Labels then
         Error_Msg_Node_1 := Name;
         Error_Msg_SP -- CODEFIX
           ("(style) `EXIT &` required");
      end if;
   end No_Exit_Name;

   ----------------------------
   -- Non_Lower_Case_Keyword --
   ----------------------------

   --  In check casing mode (-gnatyk), reserved keywords must be spelled
   --  in all lower case (excluding keywords range, access, delta and digits
   --  used as attribute designators).

   procedure Non_Lower_Case_Keyword is
   begin
      if Style_Check_Keyword_Casing then
         Error_Msg_SC -- CODEFIX
           ("(style) reserved words must be all lower case");
      end if;
   end Non_Lower_Case_Keyword;

   -----------------------------
   -- Require_Following_Space --
   -----------------------------

   procedure Require_Following_Space is
   begin
      if Source (Scan_Ptr) > ' ' then
         Error_Space_Required (Scan_Ptr);
      end if;
   end Require_Following_Space;

   -----------------------------
   -- Require_Preceding_Space --
   -----------------------------

   procedure Require_Preceding_Space is
   begin
      if Token_Ptr > Source_First (Current_Source_File)
        and then Source (Token_Ptr - 1) > ' '
      then
         Error_Space_Required (Token_Ptr);
      end if;
   end Require_Preceding_Space;

end Styleg;