1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2007, Free Software Foundation, Inc. --
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. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 -- This version of the Style package implements the standard GNAT style
27 -- checking rules. For documentation of these rules, see comments on the
28 -- individual procedures.
30 with Casing; use Casing;
31 with Csets; use Csets;
32 with Err_Vars; use Err_Vars;
34 with Scans; use Scans;
35 with Sinput; use Sinput;
36 with Stylesw; use Stylesw;
38 package body Styleg is
42 Blank_Lines : Nat := 0;
43 -- Counts number of empty lines seen. Reset to zero if a non-empty line
44 -- is encountered. Used to check for trailing blank lines in Check_EOF,
45 -- and for multiple blank lines.
47 Blank_Line_Location : Source_Ptr;
48 -- Remembers location of first blank line in a series. Used to issue an
49 -- appropriate diagnostic if subsequent blank lines or the end of file
52 -----------------------
53 -- Local Subprograms --
54 -----------------------
56 procedure Check_No_Space_After;
57 -- Checks that there is a non-white space character after the current
58 -- token, or white space followed by a comment, or the end of line.
59 -- Issue error message if not.
61 procedure Check_No_Space_Before;
62 -- Check that token is first token on line, or else is not preceded
63 -- by white space. Signal error of space not allowed if not.
65 procedure Check_Separate_Stmt_Lines_Cont;
66 -- Non-inlined continuation of Check_Separate_Stmt_Lines
68 function Determine_Token_Casing return Casing_Type;
69 -- Determine casing of current token
71 procedure Error_Space_Not_Allowed (S : Source_Ptr);
72 -- Posts an error message indicating that a space is not allowed
73 -- at the given source location.
75 procedure Error_Space_Required (S : Source_Ptr);
76 -- Posts an error message indicating that a space is required at
77 -- the given source location.
79 function Is_White_Space (C : Character) return Boolean;
80 pragma Inline (Is_White_Space);
81 -- Returns True for space, HT, VT or FF, False otherwise
83 procedure Require_Following_Space;
84 pragma Inline (Require_Following_Space);
85 -- Require token to be followed by white space. Used only if in GNAT
86 -- style checking mode.
88 procedure Require_Preceding_Space;
89 pragma Inline (Require_Preceding_Space);
90 -- Require token to be preceded by white space. Used only if in GNAT
91 -- style checking mode.
93 ----------------------
94 -- Check_Abs_Or_Not --
95 ----------------------
97 -- In check tokens mode (-gnatyt), ABS/NOT must be followed by a space
99 procedure Check_Abs_Not is
101 if Style_Check_Tokens then
102 if Source (Scan_Ptr) > ' ' then
103 Error_Space_Required (Scan_Ptr);
108 ----------------------
109 -- Check_Apostrophe --
110 ----------------------
112 -- Do not allow space before or after apostrophe
114 procedure Check_Apostrophe is
116 if Style_Check_Tokens then
117 Check_No_Space_After;
119 end Check_Apostrophe;
125 -- In check tokens mode (-gnatys), arrow must be surrounded by spaces
127 procedure Check_Arrow is
129 if Style_Check_Tokens then
130 Require_Preceding_Space;
131 Require_Following_Space;
135 --------------------------
136 -- Check_Attribute_Name --
137 --------------------------
139 -- In check attribute casing mode (-gnatya), attribute names must be
140 -- mixed case, i.e. start with an upper case letter, and otherwise
141 -- lower case, except after an underline character.
143 procedure Check_Attribute_Name (Reserved : Boolean) is
144 pragma Warnings (Off, Reserved);
146 if Style_Check_Attribute_Casing then
147 if Determine_Token_Casing /= Mixed_Case then
148 Error_Msg_SC ("(style) bad capitalization, mixed case required");
151 end Check_Attribute_Name;
153 ---------------------------
154 -- Check_Binary_Operator --
155 ---------------------------
157 -- In check token mode (-gnatyt), binary operators other than the special
158 -- case of exponentiation require surrounding space characters.
160 procedure Check_Binary_Operator is
162 if Style_Check_Tokens then
163 Require_Preceding_Space;
164 Require_Following_Space;
166 end Check_Binary_Operator;
172 -- In check token mode (-gnatyt), box must be preceded by a space or by
173 -- a left parenthesis. Spacing checking on the surrounding tokens takes
174 -- care of the remaining checks.
176 procedure Check_Box is
178 if Style_Check_Tokens then
179 if Prev_Token /= Tok_Left_Paren then
180 Require_Preceding_Space;
189 -- In check token mode (-gnatyt), colon must be surrounded by spaces
191 procedure Check_Colon is
193 if Style_Check_Tokens then
194 Require_Preceding_Space;
195 Require_Following_Space;
199 -----------------------
200 -- Check_Colon_Equal --
201 -----------------------
203 -- In check token mode (-gnatyt), := must be surrounded by spaces
205 procedure Check_Colon_Equal is
207 if Style_Check_Tokens then
208 Require_Preceding_Space;
209 Require_Following_Space;
211 end Check_Colon_Equal;
217 -- In check token mode (-gnatyt), comma must be either the first
218 -- token on a line, or be preceded by a non-blank character.
219 -- It must also always be followed by a blank.
221 procedure Check_Comma is
223 if Style_Check_Tokens then
224 Check_No_Space_Before;
226 if Source (Scan_Ptr) > ' ' then
227 Error_Space_Required (Scan_Ptr);
236 -- In check comment mode (-gnatyc) there are several requirements on the
237 -- format of comments. The following are permissible comment formats:
239 -- 1. Any comment that is not at the start of a line, i.e. where the
240 -- initial minuses are not the first non-blank characters on the
241 -- line must have at least one blank after the second minus.
243 -- 2. A row of all minuses of any length is permitted (see procedure
244 -- box above in the source of this routine).
246 -- 3. A comment line starting with two minuses and a space, and ending
247 -- with a space and two minuses. Again see the procedure title box
248 -- immediately above in the source.
250 -- 4. A full line comment where two spaces follow the two minus signs.
251 -- This is the normal comment format in GNAT style, as typified by
252 -- the comments you are reading now.
254 -- 5. A full line comment where the first character after the second
255 -- minus is a special character, i.e. a character in the ASCII
256 -- range 16#21#..16#2F# or 16#3A#..16#3F#. This allows special
257 -- comments, such as those generated by gnatprep, or those that
258 -- appear in the SPARK annotation language to be accepted.
260 -- Note: for GNAT internal files (-gnatg switch set on for the
261 -- compilation), the only special sequence recognized and allowed
262 -- is --! as generated by gnatprep.
264 procedure Check_Comment is
268 function Is_Box_Comment return Boolean;
269 -- Returns True if the last two characters on the line are -- which
270 -- characterizes a box comment (as for example follows this spec).
276 function Is_Box_Comment return Boolean is
280 -- Do we need to worry about UTF_32 line terminators here ???
283 while Source (S) not in Line_Terminator loop
287 return Source (S - 1) = '-' and then Source (S - 2) = '-';
290 -- Start of processing for Check_Comment
293 -- Can never have a non-blank character preceding the first minus
295 if Style_Check_Comments then
296 if Scan_Ptr > Source_First (Current_Source_File)
297 and then Source (Scan_Ptr - 1) > ' '
299 Error_Msg_S ("(style) space required");
303 -- For a comment that is not at the start of the line, the only
304 -- requirement is that we cannot have a non-blank character after
305 -- the second minus sign.
307 if Scan_Ptr /= First_Non_Blank_Location then
308 if Style_Check_Comments then
309 if Source (Scan_Ptr + 2) > ' ' then
310 Error_Msg ("(style) space required", Scan_Ptr + 2);
316 -- Case of a comment that is at the start of a line
319 -- First check, must be in appropriately indented column
321 if Style_Check_Indentation /= 0 then
322 if Start_Column rem Style_Check_Indentation /= 0 then
323 Error_Msg_S ("(style) bad column");
328 -- If we are not checking comments, nothing to do
330 if not Style_Check_Comments then
334 -- Case of not followed by a blank. Usually wrong, but there are
335 -- some exceptions that we permit.
337 if Source (Scan_Ptr + 2) /= ' ' then
338 C := Source (Scan_Ptr + 2);
340 -- Case of -- all on its own on a line is OK
346 -- Case of --x, x special character is OK (gnatprep/SPARK/etc.)
347 -- This is not permitted in internal GNAT implementation units
348 -- except for the case of --! as used by gnatprep output.
356 if Character'Pos (C) in 16#21# .. 16#2F#
358 Character'Pos (C) in 16#3A# .. 16#3F#
364 -- The only other case in which we allow a character after
365 -- the -- other than a space is when we have a row of minus
366 -- signs (case of header lines for a box comment for example).
369 while Source (S) >= ' ' loop
370 if Source (S) /= '-' then
371 if Is_Box_Comment then
372 Error_Space_Required (Scan_Ptr + 2);
374 Error_Msg ("(style) two spaces required", Scan_Ptr + 2);
383 -- If we are followed by a blank, then the comment is OK if the
384 -- character following this blank is another blank or a format
387 elsif Source (Scan_Ptr + 3) <= ' ' then
390 -- Here is the case where we only have one blank after the two
391 -- minus signs, which is an error unless the line ends with two
392 -- minus signs, the case of a box comment.
394 elsif not Is_Box_Comment then
395 Error_Space_Required (Scan_Ptr + 3);
404 -- In check token mode (-gnatyt), colon must be surrounded by spaces
406 procedure Check_Dot_Dot is
408 if Style_Check_Tokens then
409 Require_Preceding_Space;
410 Require_Following_Space;
418 -- In check blanks at end mode, check no blank lines precede the EOF
420 procedure Check_EOF is
422 if Style_Check_Blank_Lines then
424 -- We expect one blank line, from the EOF, but no more than one
426 if Blank_Lines = 2 then
428 ("(style) blank line not allowed at end of file",
429 Blank_Line_Location);
431 elsif Blank_Lines >= 3 then
433 ("(style) blank lines not allowed at end of file",
434 Blank_Line_Location);
439 -----------------------------------
440 -- Check_Exponentiation_Operator --
441 -----------------------------------
443 -- No spaces are required for the ** operator in GNAT style check mode
445 procedure Check_Exponentiation_Operator is
448 end Check_Exponentiation_Operator;
454 -- In check horizontal tab mode (-gnatyh), tab characters are not allowed
456 procedure Check_HT is
458 if Style_Check_Horizontal_Tabs then
459 Error_Msg_S ("(style) horizontal tab not allowed");
463 -----------------------
464 -- Check_Indentation --
465 -----------------------
467 -- In check indentation mode (-gnatyn for n a digit), a new statement or
468 -- declaration is required to start in a column that is a multiple of the
469 -- indentiation amount.
471 procedure Check_Indentation is
473 if Style_Check_Indentation /= 0 then
474 if Token_Ptr = First_Non_Blank_Location
475 and then Start_Column rem Style_Check_Indentation /= 0
477 Error_Msg_SC ("(style) bad indentation");
480 end Check_Indentation;
482 ----------------------
483 -- Check_Left_Paren --
484 ----------------------
486 -- In tone check mode (-gnatyt), left paren must not be preceded by an
487 -- identifier character or digit (a separating space is required) and
488 -- may never be followed by a space.
490 procedure Check_Left_Paren is
492 if Style_Check_Tokens then
493 if Token_Ptr > Source_First (Current_Source_File)
494 and then Identifier_Char (Source (Token_Ptr - 1))
496 Error_Space_Required (Token_Ptr);
499 Check_No_Space_After;
501 end Check_Left_Paren;
503 ---------------------------
504 -- Check_Line_Max_Length --
505 ---------------------------
507 -- In check max line length mode (-gnatym), the line length must
508 -- not exceed the permitted maximum value.
510 procedure Check_Line_Max_Length (Len : Int) is
512 if Style_Check_Max_Line_Length then
513 if Len > Style_Max_Line_Length then
515 ("(style) this line is too long",
516 Current_Line_Start + Source_Ptr (Style_Max_Line_Length));
519 end Check_Line_Max_Length;
521 ---------------------------
522 -- Check_Line_Terminator --
523 ---------------------------
525 -- In check blanks at end mode (-gnatyb), lines may not end with a
528 -- In check form feeds mode (-gnatyf), the line terminator may not
529 -- be either of the characters FF or VT.
531 -- In check DOS line terminators node (-gnatyd), the line terminator
532 -- must be a single LF, without a following CR.
534 procedure Check_Line_Terminator (Len : Int) is
538 -- Length of line (adjusted down for blanks at end of line)
541 -- Reset count of blank lines if first line
543 if Get_Logical_Line_Number (Scan_Ptr) = 1 then
547 -- Check FF/VT terminators
549 if Style_Check_Form_Feeds then
550 if Source (Scan_Ptr) = ASCII.FF then
551 Error_Msg_S ("(style) form feed not allowed");
552 elsif Source (Scan_Ptr) = ASCII.VT then
553 Error_Msg_S ("(style) vertical tab not allowed");
557 -- Check DOS line terminator (ignore EOF, since we only get called
558 -- with an EOF if it is the last character in the buffer, and was
559 -- therefore not present in the sources
561 if Style_Check_DOS_Line_Terminator then
562 if Source (Scan_Ptr) = EOF then
564 elsif Source (Scan_Ptr) /= LF
565 or else Source (Scan_Ptr + 1) = CR
567 Error_Msg_S ("(style) incorrect line terminator");
571 -- Remove trailing spaces
574 while L > 0 and then Is_White_Space (Source (S - 1)) loop
579 -- Issue message for blanks at end of line if option enabled
581 if Style_Check_Blanks_At_End and then L < Len then
583 ("(style) trailing spaces not permitted", S);
586 -- Deal with empty (blank) line
590 -- Increment blank line count
592 Blank_Lines := Blank_Lines + 1;
594 -- If first blank line, record location for later error message
596 if Blank_Lines = 1 then
597 Blank_Line_Location := Scan_Ptr;
600 -- Non-blank line, check for previous multiple blank lines
603 if Style_Check_Blank_Lines and then Blank_Lines > 1 then
605 ("(style) multiple blank lines", Blank_Line_Location);
608 -- And reset blank line count
612 end Check_Line_Terminator;
614 --------------------------
615 -- Check_No_Space_After --
616 --------------------------
618 procedure Check_No_Space_After is
622 if Is_White_Space (Source (Scan_Ptr)) then
624 -- Allow one or more spaces if followed by comment
628 if Source (S) = '-' and then Source (S + 1) = '-' then
631 elsif Is_White_Space (Source (S)) then
639 Error_Space_Not_Allowed (Scan_Ptr);
641 end Check_No_Space_After;
643 ---------------------------
644 -- Check_No_Space_Before --
645 ---------------------------
647 procedure Check_No_Space_Before is
649 if Token_Ptr > First_Non_Blank_Location
650 and then Source (Token_Ptr - 1) <= ' '
652 Error_Space_Not_Allowed (Token_Ptr - 1);
654 end Check_No_Space_Before;
656 -----------------------
657 -- Check_Pragma_Name --
658 -----------------------
660 -- In check pragma casing mode (-gnatyp), pragma names must be mixed
661 -- case, i.e. start with an upper case letter, and otherwise lower case,
662 -- except after an underline character.
664 procedure Check_Pragma_Name is
666 if Style_Check_Pragma_Casing then
667 if Determine_Token_Casing /= Mixed_Case then
668 Error_Msg_SC ("(style) bad capitalization, mixed case required");
671 end Check_Pragma_Name;
673 -----------------------
674 -- Check_Right_Paren --
675 -----------------------
677 -- In check tokens mode (-gnatyt), right paren must never be preceded by
678 -- a space unless it is the initial non-blank character on the line.
680 procedure Check_Right_Paren is
682 if Style_Check_Tokens then
683 Check_No_Space_Before;
685 end Check_Right_Paren;
687 ---------------------
688 -- Check_Semicolon --
689 ---------------------
691 -- In check tokens mode (-gnatyt), semicolon does not permit a preceding
692 -- space and a following space is required.
694 procedure Check_Semicolon is
696 if Style_Check_Tokens then
697 Check_No_Space_Before;
699 if Source (Scan_Ptr) > ' ' then
700 Error_Space_Required (Scan_Ptr);
705 -------------------------------
706 -- Check_Separate_Stmt_Lines --
707 -------------------------------
709 procedure Check_Separate_Stmt_Lines is
711 if Style_Check_Separate_Stmt_Lines then
712 Check_Separate_Stmt_Lines_Cont;
714 end Check_Separate_Stmt_Lines;
716 ------------------------------------
717 -- Check_Separate_Stmt_Lines_Cont --
718 ------------------------------------
720 procedure Check_Separate_Stmt_Lines_Cont is
724 -- Skip past white space
727 while Is_White_Space (Source (S)) loop
731 -- Line terminator is OK
733 if Source (S) in Line_Terminator then
738 elsif Source (S) = '-' and then Source (S + 1) = '-' then
741 -- ABORT keyword is OK after THEN (THEN ABORT case)
743 elsif Token = Tok_Then
744 and then (Source (S + 0) = 'a' or else Source (S + 0) = 'A')
745 and then (Source (S + 1) = 'b' or else Source (S + 1) = 'B')
746 and then (Source (S + 2) = 'o' or else Source (S + 2) = 'O')
747 and then (Source (S + 3) = 'r' or else Source (S + 3) = 'R')
748 and then (Source (S + 4) = 't' or else Source (S + 4) = 'T')
749 and then (Source (S + 5) in Line_Terminator
750 or else Is_White_Space (Source (S + 5)))
754 -- PRAGMA keyword is OK after ELSE
756 elsif Token = Tok_Else
757 and then (Source (S + 0) = 'p' or else Source (S + 0) = 'P')
758 and then (Source (S + 1) = 'r' or else Source (S + 1) = 'R')
759 and then (Source (S + 2) = 'a' or else Source (S + 2) = 'A')
760 and then (Source (S + 3) = 'g' or else Source (S + 3) = 'G')
761 and then (Source (S + 4) = 'm' or else Source (S + 4) = 'M')
762 and then (Source (S + 5) = 'a' or else Source (S + 5) = 'A')
763 and then (Source (S + 6) in Line_Terminator
764 or else Is_White_Space (Source (S + 6)))
768 -- Otherwise we have the style violation we are looking for
771 if Token = Tok_Then then
773 ("(style) no statements may follow THEN on same line", S);
776 ("(style) no statements may follow ELSE on same line", S);
779 end Check_Separate_Stmt_Lines_Cont;
785 -- In check if then layout mode (-gnatyi), we expect a THEN keyword
786 -- to appear either on the same line as the IF, or on a separate line
787 -- after multiple conditions. In any case, it may not appear on the
788 -- line immediately following the line with the IF.
790 procedure Check_Then (If_Loc : Source_Ptr) is
792 if Style_Check_If_Then_Layout then
793 if Get_Physical_Line_Number (Token_Ptr) =
794 Get_Physical_Line_Number (If_Loc) + 1
796 Error_Msg_SC ("(style) misplaced THEN");
801 -------------------------------
802 -- Check_Unary_Plus_Or_Minus --
803 -------------------------------
805 -- In check tokem mode (-gnatyt), unary plus or minus must not be
806 -- followed by a space.
808 procedure Check_Unary_Plus_Or_Minus is
810 if Style_Check_Tokens then
811 Check_No_Space_After;
813 end Check_Unary_Plus_Or_Minus;
815 ------------------------
816 -- Check_Vertical_Bar --
817 ------------------------
819 -- In check token mode (-gnatyt), vertical bar must be surrounded by spaces
821 procedure Check_Vertical_Bar is
823 if Style_Check_Tokens then
824 Require_Preceding_Space;
825 Require_Following_Space;
827 end Check_Vertical_Bar;
829 -----------------------
830 -- Check_Xtra_Parens --
831 -----------------------
833 procedure Check_Xtra_Parens (Loc : Source_Ptr) is
835 if Style_Check_Xtra_Parens then
836 Error_Msg ("redundant parentheses?", Loc);
838 end Check_Xtra_Parens;
840 ----------------------------
841 -- Determine_Token_Casing --
842 ----------------------------
844 function Determine_Token_Casing return Casing_Type is
846 return Determine_Casing (Source (Token_Ptr .. Scan_Ptr - 1));
847 end Determine_Token_Casing;
849 -----------------------------
850 -- Error_Space_Not_Allowed --
851 -----------------------------
853 procedure Error_Space_Not_Allowed (S : Source_Ptr) is
855 Error_Msg ("(style) space not allowed", S);
856 end Error_Space_Not_Allowed;
858 --------------------------
859 -- Error_Space_Required --
860 --------------------------
862 procedure Error_Space_Required (S : Source_Ptr) is
864 Error_Msg ("(style) space required", S);
865 end Error_Space_Required;
871 function Is_White_Space (C : Character) return Boolean is
873 return C = ' ' or else C = HT;
880 function Mode_In_Check return Boolean is
882 return Style_Check and Style_Check_Mode_In;
889 -- In check end/exit labels mode (-gnatye), always require the name of
890 -- a subprogram or package to be present on the END, so this is an error.
892 procedure No_End_Name (Name : Node_Id) is
894 if Style_Check_End_Labels then
895 Error_Msg_Node_1 := Name;
896 Error_Msg_SP ("(style) `END &` required");
904 -- In check end/exit labels mode (-gnatye), always require the name of
905 -- the loop to be present on the EXIT when exiting a named loop.
907 procedure No_Exit_Name (Name : Node_Id) is
909 if Style_Check_End_Labels then
910 Error_Msg_Node_1 := Name;
911 Error_Msg_SP ("(style) `EXIT &` required");
915 ----------------------------
916 -- Non_Lower_Case_Keyword --
917 ----------------------------
919 -- In check casing mode (-gnatyk), reserved keywords must be be spelled
920 -- in all lower case (excluding keywords range, access, delta and digits
921 -- used as attribute designators).
923 procedure Non_Lower_Case_Keyword is
925 if Style_Check_Keyword_Casing then
926 Error_Msg_SC ("(style) reserved words must be all lower case");
928 end Non_Lower_Case_Keyword;
930 -----------------------------
931 -- Require_Following_Space --
932 -----------------------------
934 procedure Require_Following_Space is
936 if Source (Scan_Ptr) > ' ' then
937 Error_Space_Required (Scan_Ptr);
939 end Require_Following_Space;
941 -----------------------------
942 -- Require_Preceding_Space --
943 -----------------------------
945 procedure Require_Preceding_Space is
947 if Token_Ptr > Source_First (Current_Source_File)
948 and then Source (Token_Ptr - 1) > ' '
950 Error_Space_Required (Token_Ptr);
952 end Require_Preceding_Space;
954 ---------------------
955 -- RM_Column_Check --
956 ---------------------
958 function RM_Column_Check return Boolean is
960 return Style_Check and Style_Check_Layout;