File : 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) 1992-2015, 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_End_Labels : Boolean := False;
117 -- This can be set True by using the -gnatye switch. If it is True, then
118 -- optional END labels must always be present.
119
120 Style_Check_Form_Feeds : Boolean := False;
121 -- This can be set True by using the -gnatyf switch. If it is True, then
122 -- form feeds and vertical tabs are not allowed in the source text.
123
124 Style_Check_Horizontal_Tabs : Boolean := False;
125 -- This can be set True by using the -gnatyh switch. If it is True, then
126 -- horizontal tabs are not allowed in source text.
127
128 Style_Check_If_Then_Layout : Boolean := False;
129 -- This can be set True by using the -gnatyi switch. If it is True, then a
130 -- THEN keyword must either appear on the same line as the IF, or on a line
131 -- all on its own.
132 --
133 -- This permits one of two styles for IF-THEN layout. Either the IF and
134 -- THEN keywords are on the same line, where the condition is short enough,
135 -- or the conditions are continued over to the lines following the IF and
136 -- the THEN stands on its own. For example:
137 --
138 -- if X > Y then
139 --
140 -- if X > Y
141 -- and then Y < Z
142 -- then
143 --
144 -- if X > Y and then Z > 0
145 -- then
146 --
147 -- are allowed, but
148 --
149 -- if X > Y
150 -- and then B > C then
151 --
152 -- is not allowed.
153
154 Style_Check_Indentation : Column_Number range 0 .. 9 := 0;
155 -- This can be set non-zero by using the -gnaty? (? a digit) switch. If
156 -- it is non-zero it activates indentation checking with the indicated
157 -- indentation value. A value of zero turns off checking. The requirement
158 -- is that any new statement, line comment, declaration or keyword such
159 -- as END, start on a column that is a multiple of the indentation value.
160
161 Style_Check_Keyword_Casing : Boolean := False;
162 -- This can be set True by using the -gnatyk switch. If it is True, then
163 -- keywords are required to be in all lower case. This rule does not apply
164 -- to keywords such as digits appearing as an attribute name.
165
166 Style_Check_Layout : Boolean := False;
167 -- This can be set True by using the -gnatyl switch. If it is True, it
168 -- activates checks that constructs are indented as suggested by the
169 -- examples in the RM syntax, e.g. that the ELSE keyword must line up
170 -- with the IF keyword.
171
172 Style_Check_Max_Line_Length : Boolean := False;
173 -- This can be set True by using the -gnatym/M switches. If it is True, it
174 -- activates checking for a maximum line length of Style_Max_Line_Length
175 -- characters.
176
177 Style_Check_Max_Nesting_Level : Boolean := False;
178 -- This can be set True by using -gnatyLnnn with a value other than zero
179 -- (a value of zero resets it to False). If True, it activates checking
180 -- the maximum nesting level against Style_Max_Nesting_Level.
181
182 Style_Check_Missing_Overriding : Boolean := False;
183 -- This can be set True by using the -gnatyO switch. If it is True, then
184 -- "overriding" is required in subprogram declarations and bodies where
185 -- appropriate. Note that "not overriding" is never required.
186
187 Style_Check_Mode_In : Boolean := False;
188 -- This can be set True by using -gnatyI. If True, it activates checking
189 -- that mode IN is not used on its own (since it is the default).
190
191 Style_Check_Order_Subprograms : Boolean := False;
192 -- This can be set True by using the -gnatyo switch. If it is True, then
193 -- names of subprogram bodies must be in alphabetical order (not taking
194 -- casing into account).
195
196 Style_Check_Pragma_Casing : Boolean := False;
197 -- This can be set True by using the -gnatyp switch. If it is True, then
198 -- pragma names must use mixed case.
199
200 Style_Check_References : Boolean := False;
201 -- This can be set True by using the -gnatyr switch. If it is True, then
202 -- all references to declared identifiers are checked. The requirement
203 -- is that casing of the reference be the same as the casing of the
204 -- corresponding declaration.
205
206 Style_Check_Separate_Stmt_Lines : Boolean := False;
207 -- This can be set True by using the -gnatyS switch. If it is TRUE,
208 -- then for the case of keywords THEN (not preceded by AND) or ELSE (not
209 -- preceded by OR) which introduce a conditionally executed statement
210 -- sequence, there must be no tokens on the same line as the keyword, so
211 -- that coverage testing can clearly identify execution of the statement
212 -- sequence. A comment is permitted, as is THEN ABORT or a PRAGMA keyword
213 -- after ELSE (a common style to specify the condition for the ELSE).
214
215 Style_Check_Specs : Boolean := False;
216 -- This can be set True by using the -gnatys switches. If it is True, then
217 -- separate specs are required to be present for all procedures except
218 -- parameterless library level procedures. The exception means that typical
219 -- main programs do not require separate specs.
220
221 Style_Check_Standard : Boolean := False;
222 -- This can be set True by using the -gnatyn switch. If it is True, then
223 -- any references to names in Standard have to be cased in a manner that
224 -- is consistent with the Ada RM (usually Mixed case, as in Long_Integer)
225 -- but there are some exceptions (e.g. NUL, ASCII).
226
227 Style_Check_Tokens : Boolean := False;
228 -- This can be set True by using the -gnatyt switch. If it is True, then
229 -- the style check that requires canonical spacing between various
230 -- punctuation tokens as follows:
231 --
232 -- ABS and NOT must be followed by a space
233 --
234 -- => must be surrounded by spaces
235 --
236 -- <> must be preceded by a space or left paren
237 --
238 -- Binary operators other than ** must be surrounded by spaces.
239 --
240 -- There is no restriction on the layout of the ** binary operator.
241 --
242 -- Colon must be surrounded by spaces
243 --
244 -- Colon-equal (assignment) must be surrounded by spaces
245 --
246 -- Comma must be the first non-blank character on the line, or be
247 -- immediately preceded by a non-blank character, and must be followed
248 -- by a blank.
249 --
250 -- A space must precede a left paren following a digit or letter, and a
251 -- right paren must not be followed by a space (it can be at the end of
252 -- the line).
253 --
254 -- A right paren must either be the first non-blank character on a line,
255 -- or it must be preceded by a non-blank character.
256 --
257 -- A semicolon must not be preceded by a blank, and must not be followed
258 -- by a non-blank character.
259 --
260 -- A unary plus or minus may not be followed by a space
261 --
262 -- There must be one blank (and no other white space) between NOT and IN
263 --
264 -- A vertical bar must be surrounded by spaces
265 --
266 -- Note that a requirement that a token be preceded by a space is met by
267 -- placing the token at the start of the line, and similarly a requirement
268 -- that a token be followed by a space is met by placing the token at
269 -- the end of the line. Note that in the case where horizontal tabs are
270 -- permitted, a horizontal tab is acceptable for meeting the requirement
271 -- for a space.
272
273 Style_Check_Xtra_Parens : Boolean := False;
274 -- This can be set True by using the -gnatyx switch. If true, then it is
275 -- not allowed to enclose entire expressions in tests in parentheses
276 -- (C style), e.g. if (x = y) then ... is not allowed.
277
278 Style_Max_Line_Length : Nat := 0;
279 -- Value used to check maximum line length. Gets reset as a result of
280 -- use of -gnatym or -gnatyMnnn switches. This value is only read if
281 -- Style_Check_Max_Line_Length is True.
282
283 Style_Max_Nesting_Level : Nat := 0;
284 -- Value used to check maximum nesting level. Gets reset as a result
285 -- of use of the -gnatyLnnn switch. This value is only read if
286 -- Style_Check_Max_Nesting_Level is True.
287
288 -----------------
289 -- Subprograms --
290 -----------------
291
292 function RM_Column_Check return Boolean;
293 -- Determines whether style checking is active and the RM column check
294 -- mode is set requiring checking of RM format layout.
295
296 procedure Set_Default_Style_Check_Options;
297 -- This procedure is called to set the default style checking options in
298 -- response to a -gnaty switch with no suboptions or from -gnatyy.
299
300 procedure Set_GNAT_Style_Check_Options;
301 -- This procedure is called to set the default style checking options for
302 -- GNAT units (as set by -gnatg or -gnatyg).
303
304 Style_Msg_Buf : String (1 .. 80);
305 Style_Msg_Len : Natural;
306 -- Used to return
307
308 procedure Set_Style_Check_Options
309 (Options : String;
310 OK : out Boolean;
311 Err_Col : out Natural);
312 -- This procedure is called to set the style check options that correspond
313 -- to the characters in the given Options string. If all options are valid,
314 -- they are set in an additive manner: any previous options are retained
315 -- unless overridden, unless a minus is encountered, and then subsequent
316 -- style switches are subtracted from the current set.
317 --
318 -- If all options given are valid, then OK is True, Err_Col is set to
319 -- Options'Last + 1, and Style_Msg_Buf/Style_Msg_Len are unchanged.
320 --
321 -- If an invalid character is found, then OK is False on exit, and Err_Col
322 -- is the index in options of the bad character. In this case Style_Msg_Len
323 -- is set and Style_Msg_Buf (1 .. Style_Msg_Len) has a detailed message
324 -- describing the error.
325
326 procedure Set_Style_Check_Options (Options : String);
327 -- Like the above procedure, but used when the Options string is known to
328 -- be valid. This is for example appropriate for calls where the string was
329 -- obtained by Save_Style_Check_Options.
330
331 procedure Reset_Style_Check_Options;
332 -- Sets all style check options to off
333
334 subtype Style_Check_Options is String (1 .. 64);
335 -- Long enough string to hold all options from Save call below
336
337 procedure Save_Style_Check_Options (Options : out Style_Check_Options);
338 -- Sets Options to represent current selection of options. This set can be
339 -- restored by first calling Reset_Style_Check_Options, and then calling
340 -- Set_Style_Check_Options with the Options string.
341
342 end Stylesw;