gcc/ada/stylesw.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                              S T Y L E S W                               --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2020, Free Software Foundation, Inc.         --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 3,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT; see file COPYING3.  If not, go to --
  19 -- http://www.gnu.org/licenses for a complete copy of the license.          --
  20 --                                                                          --
  21 -- GNAT was originally developed  by the GNAT team at  New York University. --
  22 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  23 --                                                                          --
  24 ------------------------------------------------------------------------------
  25
  26 --  This package contains the style switches used for setting style options.
  27 --  The only clients of this package are the body of Style and the body of
  28 --  Switches. All other style checking issues are handled using the public
  29 --  interfaces in the spec of Style.
  30
  31 with Types; use Types;
  32
  33 package Stylesw is
  34
  35    --------------------------
  36    -- Style Check Switches --
  37    --------------------------
  38
  39    --  These flags are used to control the details of the style checking
  40    --  options. The default values shown here correspond to no style checking.
  41
  42    --  If any of these values is set to a non-default value, then
  43    --  Opt.Style_Check is set True to activate calls to this package.
  44
  45    --  The actual mechanism for setting these switches to other than default
  46    --  values is via the Set_Style_Check_Options procedure or through a call to
  47    --  Set_Default_Style_Check_Options. They should not be set directly in any
  48    --  other manner.
  49
  50    Style_Check_Array_Attribute_Index : Boolean := False;
  51    --  This can be set True by using the -gnatyA switch. If it is True then
  52    --  index numbers for array attributes (like Length) are required to be
  53    --  absent for one-dimensional arrays and present for multi-dimensional
  54    --  array attribute references.
  55
  56    Style_Check_Attribute_Casing : Boolean := False;
  57    --  This can be set True by using the -gnatya switch. If it is True, then
  58    --  attribute names (including keywords such as digits used as attribute
  59    --  names) must be in mixed case.
  60
  61    Style_Check_Blanks_At_End : Boolean := False;
  62    --  This can be set True by using the -gnatyb switch. If it is True, then
  63    --  spaces at the end of lines are not permitted.
  64
  65    Style_Check_Blank_Lines : Boolean := False;
  66    --  This can be set True by using the -gnatyu switch. If it is True, then
  67    --  multiple blank lines are not permitted, and there may not be a blank
  68    --  line at the end of the file.
  69
  70    Style_Check_Boolean_And_Or : Boolean := False;
  71    --  This can be set True by using the -gnatyB switch. If it is True, then
  72    --  the use of AND THEN/OR ELSE rather than AND/OR is required except for
  73    --  the following cases:
  74    --
  75    --     a) Both operands are simple Boolean constants or variables
  76    --     b) Both operands are of a modular type
  77    --     c) Both operands are of an array type
  78
  79    Style_Check_Comments : Boolean := False;
  80    --  This can be set True by using the -gnatyc switch. If it is True, then
  81    --  comments are style checked as follows:
  82    --
  83    --    All comments must be at the start of the line, or the first minus must
  84    --    be preceded by at least one space.
  85    --
  86    --    For a comment that is not at the start of a line, the only requirement
  87    --    is that a space follow the comment characters.
  88    --
  89    --    For a comment that is at the start of the line, one of the following
  90    --    conditions must hold:
  91    --
  92    --      The comment characters are the only non-blank characters on the line
  93    --
  94    --      The comment characters are followed by an exclamation point (the
  95    --      sequence --! is used by gnatprep for marking deleted lines).
  96    --
  97    --      The comment characters are followed by two space characters if
  98    --      Comment_Spacing = 2, else by one character if Comment_Spacing = 1.
  99    --
 100    --      The line consists entirely of minus signs
 101    --
 102    --      The comment characters are followed by a single space, and the last
 103    --      two characters on the line are also comment characters.
 104    --
 105    --  Note: the reason for the last two conditions is to allow "boxed"
 106    --  comments where only a single space separates the comment characters.
 107
 108    Style_Check_Comments_Spacing : Nat range 1 .. 2;
 109    --  Spacing required for comments, valid only if Style_Check_Comments true.
 110
 111    Style_Check_DOS_Line_Terminator : Boolean := False;
 112    --  This can be set true by using the -gnatyd switch. If it is True, then
 113    --  the line terminator must be a single LF, without an associated CR (e.g.
 114    --  DOS line terminator sequence CR/LF not allowed).
 115
 116    Style_Check_Mixed_Case_Decls : Boolean := False;
 117    --  This can be set True by using the -gnatyD switch. If it is True, then
 118    --  declared identifiers must be in Mixed_Case.
 119
 120    Style_Check_End_Labels : Boolean := False;
 121    --  This can be set True by using the -gnatye switch. If it is True, then
 122    --  optional END labels must always be present.
 123
 124    Style_Check_Form_Feeds : Boolean := False;
 125    --  This can be set True by using the -gnatyf switch. If it is True, then
 126    --  form feeds and vertical tabs are not allowed in the source text.
 127
 128    Style_Check_Horizontal_Tabs : Boolean := False;
 129    --  This can be set True by using the -gnatyh switch. If it is True, then
 130    --  horizontal tabs are not allowed in source text.
 131
 132    Style_Check_If_Then_Layout : Boolean := False;
 133    --  This can be set True by using the -gnatyi switch. If it is True, then a
 134    --  THEN keyword must either appear on the same line as the IF, or on a line
 135    --  all on its own.
 136    --
 137    --  This permits one of two styles for IF-THEN layout. Either the IF and
 138    --  THEN keywords are on the same line, where the condition is short enough,
 139    --  or the conditions are continued over to the lines following the IF and
 140    --  the THEN stands on its own. For example:
 141    --
 142    --    if X > Y then
 143    --
 144    --    if X > Y
 145    --      and then Y < Z
 146    --    then
 147    --
 148    --    if X > Y and then Z > 0
 149    --    then
 150    --
 151    --  are allowed, but
 152    --
 153    --    if X > Y
 154    --      and then B > C then
 155    --
 156    --  is not allowed.
 157
 158    Style_Check_Indentation : Column_Number range 0 .. 9 := 0;
 159    --  This can be set non-zero by using the -gnaty? (? a digit) switch. If
 160    --  it is non-zero it activates indentation checking with the indicated
 161    --  indentation value. A value of zero turns off checking. The requirement
 162    --  is that any new statement, line comment, declaration or keyword such
 163    --  as END, start on a column that is a multiple of the indentation value.
 164
 165    Style_Check_Keyword_Casing : Boolean := False;
 166    --  This can be set True by using the -gnatyk switch. If it is True, then
 167    --  keywords are required to be in all lower case. This rule does not apply
 168    --  to keywords such as digits appearing as an attribute name.
 169
 170    Style_Check_Layout : Boolean := False;
 171    --  This can be set True by using the -gnatyl switch. If it is True, it
 172    --  activates checks that constructs are indented as suggested by the
 173    --  examples in the RM syntax, e.g. that the ELSE keyword must line up
 174    --  with the IF keyword.
 175
 176    Style_Check_Max_Line_Length : Boolean := False;
 177    --  This can be set True by using the -gnatym/M switches. If it is True, it
 178    --  activates checking for a maximum line length of Style_Max_Line_Length
 179    --  characters.
 180
 181    Style_Check_Max_Nesting_Level : Boolean := False;
 182    --  This can be set True by using -gnatyLnnn with a value other than zero
 183    --  (a value of zero resets it to False). If True, it activates checking
 184    --  the maximum nesting level against Style_Max_Nesting_Level.
 185
 186    Style_Check_Missing_Overriding : Boolean := False;
 187    --  This can be set True by using the -gnatyO switch. If it is True, then
 188    --  "overriding" is required in subprogram declarations and bodies where
 189    --  appropriate. Note that "not overriding" is never required.
 190
 191    Style_Check_Mode_In : Boolean := False;
 192    --  This can be set True by using -gnatyI. If True, it activates checking
 193    --  that mode IN is not used on its own (since it is the default).
 194
 195    Style_Check_Order_Subprograms : Boolean := False;
 196    --  This can be set True by using the -gnatyo switch. If it is True, then
 197    --  names of subprogram bodies must be in alphabetical order (not taking
 198    --  casing into account).
 199
 200    Style_Check_Pragma_Casing : Boolean := False;
 201    --  This can be set True by using the -gnatyp switch. If it is True, then
 202    --  pragma names must use mixed case.
 203
 204    Style_Check_References : Boolean := False;
 205    --  This can be set True by using the -gnatyr switch. If it is True, then
 206    --  all references to declared identifiers are checked. The requirement
 207    --  is that casing of the reference be the same as the casing of the
 208    --  corresponding declaration.
 209
 210    Style_Check_Separate_Stmt_Lines : Boolean := False;
 211    --  This can be set True by using the -gnatyS switch. If it is TRUE,
 212    --  then for the case of keywords THEN (not preceded by AND) or ELSE (not
 213    --  preceded by OR) which introduce a conditionally executed statement
 214    --  sequence, there must be no tokens on the same line as the keyword, so
 215    --  that coverage testing can clearly identify execution of the statement
 216    --  sequence. A comment is permitted, as is THEN ABORT or a PRAGMA keyword
 217    --  after ELSE (a common style to specify the condition for the ELSE).
 218
 219    Style_Check_Specs : Boolean := False;
 220    --  This can be set True by using the -gnatys switches. If it is True, then
 221    --  separate specs are required to be present for all procedures except
 222    --  parameterless library level procedures. The exception means that typical
 223    --  main programs do not require separate specs.
 224
 225    Style_Check_Standard : Boolean := False;
 226    --  This can be set True by using the -gnatyn switch. If it is True, then
 227    --  any references to names in Standard have to be cased in a manner that
 228    --  is consistent with the Ada RM (usually Mixed case, as in Long_Integer)
 229    --  but there are some exceptions (e.g. NUL, ASCII).
 230
 231    Style_Check_Tokens : Boolean := False;
 232    --  This can be set True by using the -gnatyt switch. If it is True, then
 233    --  the style check that requires canonical spacing between various
 234    --  punctuation tokens as follows:
 235    --
 236    --    ABS and NOT must be followed by a space
 237    --
 238    --    => must be surrounded by spaces
 239    --
 240    --    <> must be preceded by a space or left paren
 241    --
 242    --    Binary operators other than ** must be surrounded by spaces.
 243    --
 244    --    There is no restriction on the layout of the ** binary operator.
 245    --
 246    --    Colon must be surrounded by spaces
 247    --
 248    --    Colon-equal (assignment) must be surrounded by spaces
 249    --
 250    --    Comma must be the first non-blank character on the line, or be
 251    --    immediately preceded by a non-blank character, and must be followed
 252    --    by a blank.
 253    --
 254    --    A space must precede a left paren following a digit or letter, and a
 255    --    right paren must not be followed by a space (it can be at the end of
 256    --    the line).
 257    --
 258    --    A right paren must either be the first non-blank character on a line,
 259    --    or it must be preceded by a non-blank character.
 260    --
 261    --    A semicolon must not be preceded by a blank, and must not be followed
 262    --    by a non-blank character.
 263    --
 264    --    A unary plus or minus may not be followed by a space
 265    --
 266    --    There must be one blank (and no other white space) between NOT and IN
 267    --
 268    --    A vertical bar must be surrounded by spaces
 269    --
 270    --  Note that a requirement that a token be preceded by a space is met by
 271    --  placing the token at the start of the line, and similarly a requirement
 272    --  that a token be followed by a space is met by placing the token at
 273    --  the end of the line. Note that in the case where horizontal tabs are
 274    --  permitted, a horizontal tab is acceptable for meeting the requirement
 275    --  for a space.
 276
 277    Style_Check_Xtra_Parens : Boolean := False;
 278    --  This can be set True by using the -gnatyx switch. If true, then it is
 279    --  not allowed to enclose entire expressions in tests in parentheses
 280    --  (C style), e.g. if (x = y) then ... is not allowed.
 281
 282    Style_Max_Line_Length : Nat := 0;
 283    --  Value used to check maximum line length. Gets reset as a result of
 284    --  use of -gnatym or -gnatyMnnn switches. This value is only read if
 285    --  Style_Check_Max_Line_Length is True.
 286
 287    Style_Max_Nesting_Level : Nat := 0;
 288    --  Value used to check maximum nesting level. Gets reset as a result
 289    --  of use of the -gnatyLnnn switch. This value is only read if
 290    --  Style_Check_Max_Nesting_Level is True.
 291
 292    -----------------
 293    -- Subprograms --
 294    -----------------
 295
 296    function RM_Column_Check return Boolean;
 297    --  Determines whether style checking is active and the RM column check
 298    --  mode is set requiring checking of RM format layout.
 299
 300    procedure Set_Default_Style_Check_Options;
 301    --  This procedure is called to set the default style checking options in
 302    --  response to a -gnaty switch with no suboptions or from -gnatyy.
 303
 304    procedure Set_GNAT_Style_Check_Options;
 305    --  This procedure is called to set the default style checking options for
 306    --  GNAT units (as set by -gnatg or -gnatyg).
 307
 308    Style_Msg_Buf : String (1 .. 80);
 309    Style_Msg_Len : Natural;
 310    --  Used to return
 311
 312    procedure Set_Style_Check_Options
 313      (Options  : String;
 314       OK       : out Boolean;
 315       Err_Col  : out Natural);
 316    --  This procedure is called to set the style check options that correspond
 317    --  to the characters in the given Options string. If all options are valid,
 318    --  they are set in an additive manner: any previous options are retained
 319    --  unless overridden, unless a minus is encountered, and then subsequent
 320    --  style switches are subtracted from the current set.
 321    --
 322    --  If all options given are valid, then OK is True, Err_Col is set to
 323    --  Options'Last + 1, and Style_Msg_Buf/Style_Msg_Len are unchanged.
 324    --
 325    --  If an invalid character is found, then OK is False on exit, and Err_Col
 326    --  is the index in options of the bad character. In this case Style_Msg_Len
 327    --  is set and Style_Msg_Buf (1 .. Style_Msg_Len) has a detailed message
 328    --  describing the error.
 329
 330    procedure Set_Style_Check_Options (Options : String);
 331    --  Like the above procedure, but used when the Options string is known to
 332    --  be valid. This is for example appropriate for calls where the string was
 333    --  obtained by Save_Style_Check_Options.
 334
 335    procedure Reset_Style_Check_Options;
 336    --  Sets all style check options to off
 337
 338    subtype Style_Check_Options is String (1 .. 64);
 339    --  Long enough string to hold all options from Save call below
 340
 341    procedure Save_Style_Check_Options (Options : out Style_Check_Options);
 342    --  Sets Options to represent current selection of options. This set can be
 343    --  restored by first calling Reset_Style_Check_Options, and then calling
 344    --  Set_Style_Check_Options with the Options string.
 345
 346 end Stylesw;