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2014-12-12 Marc Glisse <marc.glisse@inria.fr>
[official-gcc.git] / gcc / ada / scng.adb
blob3e31e5af82d57fd8c0803b119418be71ed95c528
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- S C N G --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2014, 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 with Atree; use Atree;
27 with Csets; use Csets;
28 with Hostparm; use Hostparm;
29 with Namet; use Namet;
30 with Opt; use Opt;
31 with Restrict; use Restrict;
32 with Rident; use Rident;
33 with Scans; use Scans;
34 with Sinput; use Sinput;
35 with Snames; use Snames;
36 with Stringt; use Stringt;
37 with Stylesw; use Stylesw;
38 with Uintp; use Uintp;
39 with Urealp; use Urealp;
40 with Widechar; use Widechar;
41
42 pragma Warnings (Off);
43 -- This package is used also by gnatcoll
44 with System.CRC32;
45 with System.UTF_32; use System.UTF_32;
46 with System.WCh_Con; use System.WCh_Con;
47 pragma Warnings (On);
48
49 package body Scng is
50
51 use ASCII;
52 -- Make control characters visible
53
54 Special_Characters : array (Character) of Boolean := (others => False);
55 -- For characters that are Special token, the value is True
56
57 Comment_Is_Token : Boolean := False;
58 -- True if comments are tokens
59
60 End_Of_Line_Is_Token : Boolean := False;
61 -- True if End_Of_Line is a token
62
63 -----------------------
64 -- Local Subprograms --
65 -----------------------
66
67 procedure Accumulate_Token_Checksum;
68 pragma Inline (Accumulate_Token_Checksum);
69 -- Called after each numeric literal and identifier/keyword. For keywords,
70 -- the token used is Tok_Identifier. This allows detection of additional
71 -- spaces added in sources when using the builder switch -m.
72
73 procedure Accumulate_Token_Checksum_GNAT_6_3;
74 -- Used in place of Accumulate_Token_Checksum for GNAT versions 5.04 to
75 -- 6.3, when Tok_Some was not included in Token_Type and the actual
76 -- Token_Type was used for keywords. This procedure is never used in the
77 -- compiler or gnatmake, only in gprbuild.
78
79 procedure Accumulate_Token_Checksum_GNAT_5_03;
80 -- Used in place of Accumulate_Token_Checksum for GNAT version 5.03, when
81 -- Tok_Interface, Tok_Some, Tok_Synchronized and Tok_Overriding were not
82 -- included in Token_Type and the actual Token_Type was used for keywords.
83 -- This procedure is never used in the compiler or gnatmake, only in
84 -- gprbuild.
85
86 procedure Accumulate_Checksum (C : Character);
87 pragma Inline (Accumulate_Checksum);
88 -- This routine accumulates the checksum given character C. During the
89 -- scanning of a source file, this routine is called with every character
90 -- in the source, excluding blanks, and all control characters (except
91 -- that ESC is included in the checksum). Upper case letters not in string
92 -- literals are folded by the caller. See Sinput spec for the documentation
93 -- of the checksum algorithm. Note: checksum values are only used if we
94 -- generate code, so it is not necessary to worry about making the right
95 -- sequence of calls in any error situation.
96
97 procedure Accumulate_Checksum (C : Char_Code);
98 pragma Inline (Accumulate_Checksum);
99 -- This version is identical, except that the argument, C, is a character
100 -- code value instead of a character. This is used when wide characters
101 -- are scanned. We use the character code rather than the ASCII characters
102 -- so that the checksum is independent of wide character encoding method.
103
104 procedure Initialize_Checksum;
105 pragma Inline (Initialize_Checksum);
106 -- Initialize checksum value
107
108 -------------------------
109 -- Accumulate_Checksum --
110 -------------------------
111
112 procedure Accumulate_Checksum (C : Character) is
113 begin
114 System.CRC32.Update (System.CRC32.CRC32 (Checksum), C);
115 end Accumulate_Checksum;
116
117 procedure Accumulate_Checksum (C : Char_Code) is
118 begin
119 if C > 16#FFFF# then
120 Accumulate_Checksum (Character'Val (C / 2 ** 24));
121 Accumulate_Checksum (Character'Val ((C / 2 ** 16) mod 256));
122 Accumulate_Checksum (Character'Val ((C / 256) mod 256));
123 else
124 Accumulate_Checksum (Character'Val (C / 256));
125 end if;
126
127 Accumulate_Checksum (Character'Val (C mod 256));
128 end Accumulate_Checksum;
129
130 -------------------------------
131 -- Accumulate_Token_Checksum --
132 -------------------------------
133
134 procedure Accumulate_Token_Checksum is
135 begin
136 System.CRC32.Update
137 (System.CRC32.CRC32 (Checksum),
138 Character'Val (Token_Type'Pos (Token)));
139 end Accumulate_Token_Checksum;
140
141 ----------------------------------------
142 -- Accumulate_Token_Checksum_GNAT_6_3 --
143 ----------------------------------------
144
145 procedure Accumulate_Token_Checksum_GNAT_6_3 is
146 begin
147 -- Individual values of Token_Type are used, instead of subranges, so
148 -- that additions or suppressions of enumerated values in type
149 -- Token_Type are detected by the compiler.
150
151 case Token is
152 when Tok_Integer_Literal | Tok_Real_Literal | Tok_String_Literal |
153 Tok_Char_Literal | Tok_Operator_Symbol | Tok_Identifier |
154 Tok_Double_Asterisk | Tok_Ampersand | Tok_Minus | Tok_Plus |
155 Tok_Asterisk | Tok_Mod | Tok_Rem | Tok_Slash | Tok_New |
156 Tok_Abs | Tok_Others | Tok_Null | Tok_Dot | Tok_Apostrophe |
157 Tok_Left_Paren | Tok_Delta | Tok_Digits | Tok_Range |
158 Tok_Right_Paren | Tok_Comma | Tok_And | Tok_Or | Tok_Xor |
159 Tok_Less | Tok_Equal | Tok_Greater | Tok_Not_Equal |
160 Tok_Greater_Equal | Tok_Less_Equal | Tok_In | Tok_Not |
161 Tok_Box | Tok_Colon_Equal | Tok_Colon | Tok_Greater_Greater |
162 Tok_Abstract | Tok_Access | Tok_Aliased | Tok_All | Tok_Array |
163 Tok_At | Tok_Body | Tok_Constant | Tok_Do | Tok_Is |
164 Tok_Interface | Tok_Limited | Tok_Of | Tok_Out | Tok_Record |
165 Tok_Renames | Tok_Reverse =>
166
167 System.CRC32.Update
168 (System.CRC32.CRC32 (Checksum),
169 Character'Val (Token_Type'Pos (Token)));
170
171 when Tok_Some =>
172
173 System.CRC32.Update
174 (System.CRC32.CRC32 (Checksum),
175 Character'Val (Token_Type'Pos (Tok_Identifier)));
176
177 when Tok_Tagged | Tok_Then | Tok_Less_Less | Tok_Abort | Tok_Accept |
178 Tok_Case | Tok_Delay | Tok_Else | Tok_Elsif | Tok_End |
179 Tok_Exception | Tok_Exit | Tok_Goto | Tok_If | Tok_Pragma |
180 Tok_Raise | Tok_Requeue | Tok_Return | Tok_Select |
181 Tok_Terminate | Tok_Until | Tok_When | Tok_Begin | Tok_Declare |
182 Tok_For | Tok_Loop | Tok_While | Tok_Entry | Tok_Protected |
183 Tok_Task | Tok_Type | Tok_Subtype | Tok_Overriding |
184 Tok_Synchronized | Tok_Use | Tok_Function | Tok_Generic |
185 Tok_Package | Tok_Procedure | Tok_Private | Tok_With |
186 Tok_Separate | Tok_EOF | Tok_Semicolon | Tok_Arrow |
187 Tok_Vertical_Bar | Tok_Dot_Dot | Tok_Project | Tok_Extends |
188 Tok_External | Tok_External_As_List | Tok_Comment |
189 Tok_End_Of_Line | Tok_Special | Tok_SPARK_Hide | No_Token =>
190
191 System.CRC32.Update
192 (System.CRC32.CRC32 (Checksum),
193 Character'Val (Token_Type'Pos (Token_Type'Pred (Token))));
194 end case;
195 end Accumulate_Token_Checksum_GNAT_6_3;
196
197 -----------------------------------------
198 -- Accumulate_Token_Checksum_GNAT_5_03 --
199 -----------------------------------------
200
201 procedure Accumulate_Token_Checksum_GNAT_5_03 is
202 begin
203 -- Individual values of Token_Type are used, instead of subranges, so
204 -- that additions or suppressions of enumerated values in type
205 -- Token_Type are detected by the compiler.
206
207 case Token is
208 when Tok_Integer_Literal | Tok_Real_Literal | Tok_String_Literal |
209 Tok_Char_Literal | Tok_Operator_Symbol | Tok_Identifier |
210 Tok_Double_Asterisk | Tok_Ampersand | Tok_Minus | Tok_Plus |
211 Tok_Asterisk | Tok_Mod | Tok_Rem | Tok_Slash | Tok_New |
212 Tok_Abs | Tok_Others | Tok_Null | Tok_Dot | Tok_Apostrophe |
213 Tok_Left_Paren | Tok_Delta | Tok_Digits | Tok_Range |
214 Tok_Right_Paren | Tok_Comma | Tok_And | Tok_Or | Tok_Xor |
215 Tok_Less | Tok_Equal | Tok_Greater | Tok_Not_Equal |
216 Tok_Greater_Equal | Tok_Less_Equal | Tok_In | Tok_Not |
217 Tok_Box | Tok_Colon_Equal | Tok_Colon | Tok_Greater_Greater |
218 Tok_Abstract | Tok_Access | Tok_Aliased | Tok_All | Tok_Array |
219 Tok_At | Tok_Body | Tok_Constant | Tok_Do | Tok_Is =>
220
221 System.CRC32.Update
222 (System.CRC32.CRC32 (Checksum),
223 Character'Val (Token_Type'Pos (Token)));
224
225 when Tok_Interface | Tok_Some | Tok_Overriding | Tok_Synchronized =>
226 System.CRC32.Update
227 (System.CRC32.CRC32 (Checksum),
228 Character'Val (Token_Type'Pos (Tok_Identifier)));
229
230 when Tok_Limited | Tok_Of | Tok_Out | Tok_Record |
231 Tok_Renames | Tok_Reverse =>
232
233 System.CRC32.Update
234 (System.CRC32.CRC32 (Checksum),
235 Character'Val (Token_Type'Pos (Token) - 1));
236
237 when Tok_Tagged | Tok_Then | Tok_Less_Less | Tok_Abort | Tok_Accept |
238 Tok_Case | Tok_Delay | Tok_Else | Tok_Elsif | Tok_End |
239 Tok_Exception | Tok_Exit | Tok_Goto | Tok_If | Tok_Pragma |
240 Tok_Raise | Tok_Requeue | Tok_Return | Tok_Select |
241 Tok_Terminate | Tok_Until | Tok_When | Tok_Begin | Tok_Declare |
242 Tok_For | Tok_Loop | Tok_While | Tok_Entry | Tok_Protected |
243 Tok_Task | Tok_Type | Tok_Subtype =>
244
245 System.CRC32.Update
246 (System.CRC32.CRC32 (Checksum),
247 Character'Val (Token_Type'Pos (Token) - 2));
248
249 when Tok_Use | Tok_Function | Tok_Generic |
250 Tok_Package | Tok_Procedure | Tok_Private | Tok_With |
251 Tok_Separate | Tok_EOF | Tok_Semicolon | Tok_Arrow |
252 Tok_Vertical_Bar | Tok_Dot_Dot | Tok_Project | Tok_Extends |
253 Tok_External | Tok_External_As_List | Tok_Comment |
254 Tok_End_Of_Line | Tok_Special | Tok_SPARK_Hide | No_Token =>
255
256 System.CRC32.Update
257 (System.CRC32.CRC32 (Checksum),
258 Character'Val (Token_Type'Pos (Token) - 4));
259 end case;
260 end Accumulate_Token_Checksum_GNAT_5_03;
261
262 -----------------------
263 -- Check_End_Of_Line --
264 -----------------------
265
266 procedure Check_End_Of_Line is
267 Len : constant Int :=
268 Int (Scan_Ptr) -
269 Int (Current_Line_Start) -
270 Wide_Char_Byte_Count;
271
272 -- Start of processing for Check_End_Of_Line
273
274 begin
275 if Style_Check then
276 Style.Check_Line_Terminator (Len);
277 end if;
278
279 -- Deal with checking maximum line length
280
281 if Style_Check and Style_Check_Max_Line_Length then
282 Style.Check_Line_Max_Length (Len);
283
284 -- If style checking is inactive, check maximum line length against
285 -- standard value.
286
287 elsif Len > Max_Line_Length then
288 Error_Msg
289 ("this line is too long",
290 Current_Line_Start + Source_Ptr (Max_Line_Length));
291 end if;
292
293 -- Now one more checking circuit. Normally we are only enforcing a limit
294 -- of physical characters, with tabs counting as one character. But if
295 -- after tab expansion we would have a total line length that exceeded
296 -- 32766, that would really cause trouble, because column positions
297 -- would exceed the maximum we allow for a column count. Note: the limit
298 -- is 32766 rather than 32767, since we use a value of 32767 for special
299 -- purposes (see Sinput). Now we really do not want to go messing with
300 -- tabs in the normal case, so what we do is to check for a line that
301 -- has more than 4096 physical characters. Any shorter line could not
302 -- be a problem, even if it was all tabs.
303
304 if Len >= 4096 then
305 declare
306 Col : Natural;
307 Ptr : Source_Ptr;
308
309 begin
310 Col := 1;
311 Ptr := Current_Line_Start;
312 loop
313 exit when Ptr = Scan_Ptr;
314
315 if Source (Ptr) = ASCII.HT then
316 Col := (Col - 1 + 8) / 8 * 8 + 1;
317 else
318 Col := Col + 1;
319 end if;
320
321 if Col > 32766 then
322 Error_Msg
323 ("this line is longer than 32766 characters",
324 Current_Line_Start);
325 raise Unrecoverable_Error;
326 end if;
327
328 Ptr := Ptr + 1;
329 end loop;
330 end;
331 end if;
332
333 -- Reset wide character byte count for next line
334
335 Wide_Char_Byte_Count := 0;
336 end Check_End_Of_Line;
337
338 ----------------------------
339 -- Determine_Token_Casing --
340 ----------------------------
341
342 function Determine_Token_Casing return Casing_Type is
343 begin
344 return Determine_Casing (Source (Token_Ptr .. Scan_Ptr - 1));
345 end Determine_Token_Casing;
346
347 -------------------------
348 -- Initialize_Checksum --
349 -------------------------
350
351 procedure Initialize_Checksum is
352 begin
353 System.CRC32.Initialize (System.CRC32.CRC32 (Checksum));
354 end Initialize_Checksum;
355
356 ------------------------
357 -- Initialize_Scanner --
358 ------------------------
359
360 procedure Initialize_Scanner (Index : Source_File_Index) is
361 begin
362 -- Establish reserved words
363
364 Scans.Initialize_Ada_Keywords;
365
366 -- Initialize scan control variables
367
368 Current_Source_File := Index;
369 Source := Source_Text (Current_Source_File);
370 Scan_Ptr := Source_First (Current_Source_File);
371 Token := No_Token;
372 Token_Ptr := Scan_Ptr;
373 Current_Line_Start := Scan_Ptr;
374 Token_Node := Empty;
375 Token_Name := No_Name;
376 Start_Column := Set_Start_Column;
377 First_Non_Blank_Location := Scan_Ptr;
378
379 Initialize_Checksum;
380 Wide_Char_Byte_Count := 0;
381
382 -- Do not call Scan, otherwise the License stuff does not work in Scn
383
384 end Initialize_Scanner;
385
386 ------------------------------
387 -- Reset_Special_Characters --
388 ------------------------------
389
390 procedure Reset_Special_Characters is
391 begin
392 Special_Characters := (others => False);
393 end Reset_Special_Characters;
394
395 ----------
396 -- Scan --
397 ----------
398
399 procedure Scan is
400
401 Start_Of_Comment : Source_Ptr;
402 -- Record start of comment position
403
404 Underline_Found : Boolean;
405 -- During scanning of an identifier, set to True if last character
406 -- scanned was an underline or other punctuation character. This
407 -- is used to flag the error of two underlines/punctuations in a
408 -- row or ending an identifier with a underline/punctuation. Here
409 -- punctuation means any UTF_32 character in the Unicode category
410 -- Punctuation,Connector.
411
412 Wptr : Source_Ptr;
413 -- Used to remember start of last wide character scanned
414
415 function Double_Char_Token (C : Character) return Boolean;
416 -- This function is used for double character tokens like := or <>. It
417 -- checks if the character following Source (Scan_Ptr) is C, and if so
418 -- bumps Scan_Ptr past the pair of characters and returns True. A space
419 -- between the two characters is also recognized with an appropriate
420 -- error message being issued. If C is not present, False is returned.
421 -- Note that Double_Char_Token can only be used for tokens defined in
422 -- the Ada syntax (it's use for error cases like && is not appropriate
423 -- since we do not want a junk message for a case like &-space-&).
424
425 procedure Error_Illegal_Character;
426 -- Give illegal character error, Scan_Ptr points to character. On
427 -- return, Scan_Ptr is bumped past the illegal character.
428
429 procedure Error_Illegal_Wide_Character;
430 -- Give illegal wide character message. On return, Scan_Ptr is bumped
431 -- past the illegal character, which may still leave us pointing to
432 -- junk, not much we can do if the escape sequence is messed up.
433
434 procedure Error_No_Double_Underline;
435 -- Signal error of two underline or punctuation characters in a row.
436 -- Called with Scan_Ptr pointing to second underline/punctuation char.
437
438 procedure Nlit;
439 -- This is the procedure for scanning out numeric literals. On entry,
440 -- Scan_Ptr points to the digit that starts the numeric literal (the
441 -- checksum for this character has not been accumulated yet). On return
442 -- Scan_Ptr points past the last character of the numeric literal, Token
443 -- and Token_Node are set appropriately, and the checksum is updated.
444
445 procedure Slit;
446 -- This is the procedure for scanning out string literals. On entry,
447 -- Scan_Ptr points to the opening string quote (the checksum for this
448 -- character has not been accumulated yet). On return Scan_Ptr points
449 -- past the closing quote of the string literal, Token and Token_Node
450 -- are set appropriately, and the checksum is updated.
451
452 procedure Skip_Other_Format_Characters;
453 -- Skips past any "other format" category characters at the current
454 -- cursor location (does not skip past spaces or any other characters).
455
456 function Start_Of_Wide_Character return Boolean;
457 -- Returns True if the scan pointer is pointing to the start of a wide
458 -- character sequence, does not modify the scan pointer in any case.
459
460 -----------------------
461 -- Double_Char_Token --
462 -----------------------
463
464 function Double_Char_Token (C : Character) return Boolean is
465 begin
466 if Source (Scan_Ptr + 1) = C then
467 Accumulate_Checksum (C);
468 Scan_Ptr := Scan_Ptr + 2;
469 return True;
470
471 elsif Source (Scan_Ptr + 1) = ' '
472 and then Source (Scan_Ptr + 2) = C
473 then
474 Scan_Ptr := Scan_Ptr + 1;
475 Error_Msg_S -- CODEFIX
476 ("no space allowed here");
477 Scan_Ptr := Scan_Ptr + 2;
478 return True;
479
480 else
481 return False;
482 end if;
483 end Double_Char_Token;
484
485 -----------------------------
486 -- Error_Illegal_Character --
487 -----------------------------
488
489 procedure Error_Illegal_Character is
490 begin
491 Error_Msg_S ("illegal character");
492 Scan_Ptr := Scan_Ptr + 1;
493 end Error_Illegal_Character;
494
495 ----------------------------------
496 -- Error_Illegal_Wide_Character --
497 ----------------------------------
498
499 procedure Error_Illegal_Wide_Character is
500 begin
501 Scan_Ptr := Scan_Ptr + 1;
502 Error_Msg ("illegal wide character", Wptr);
503 end Error_Illegal_Wide_Character;
504
505 -------------------------------
506 -- Error_No_Double_Underline --
507 -------------------------------
508
509 procedure Error_No_Double_Underline is
510 begin
511 Underline_Found := False;
512
513 -- There are four cases, and we special case the messages
514
515 if Source (Scan_Ptr) = '_' then
516 if Source (Scan_Ptr - 1) = '_' then
517 Error_Msg_S -- CODEFIX
518 ("two consecutive underlines not permitted");
519 else
520 Error_Msg_S ("underline cannot follow punctuation character");
521 end if;
522
523 else
524 if Source (Scan_Ptr - 1) = '_' then
525 Error_Msg_S ("punctuation character cannot follow underline");
526 else
527 Error_Msg_S
528 ("two consecutive punctuation characters not permitted");
529 end if;
530 end if;
531 end Error_No_Double_Underline;
532
533 ----------
534 -- Nlit --
535 ----------
536
537 procedure Nlit is
538
539 C : Character;
540 -- Current source program character
541
542 Base_Char : Character;
543 -- Either # or : (character at start of based number)
544
545 Base : Int;
546 -- Value of base
547
548 UI_Base : Uint;
549 -- Value of base in Uint format
550
551 UI_Int_Value : Uint;
552 -- Value of integer scanned by Scan_Integer in Uint format
553
554 UI_Num_Value : Uint;
555 -- Value of integer in numeric value being scanned
556
557 Scale : Int;
558 -- Scale value for real literal
559
560 UI_Scale : Uint;
561 -- Scale in Uint format
562
563 Exponent_Is_Negative : Boolean;
564 -- Set true for negative exponent
565
566 Extended_Digit_Value : Int;
567 -- Extended digit value
568
569 Point_Scanned : Boolean;
570 -- Flag for decimal point scanned in numeric literal
571
572 -----------------------
573 -- Local Subprograms --
574 -----------------------
575
576 procedure Error_Digit_Expected;
577 -- Signal error of bad digit, Scan_Ptr points to the location at
578 -- which the digit was expected on input, and is unchanged on return.
579
580 procedure Scan_Integer;
581 -- Scan integer literal. On entry, Scan_Ptr points to a digit, on
582 -- exit Scan_Ptr points past the last character of the integer.
583 --
584 -- For each digit encountered, UI_Int_Value is multiplied by 10, and
585 -- the value of the digit added to the result. In addition, the value
586 -- in Scale is decremented by one for each actual digit scanned.
587
588 --------------------------
589 -- Error_Digit_Expected --
590 --------------------------
591
592 procedure Error_Digit_Expected is
593 begin
594 Error_Msg_S ("digit expected");
595 end Error_Digit_Expected;
596
597 ------------------
598 -- Scan_Integer --
599 ------------------
600
601 procedure Scan_Integer is
602 C : Character;
603 -- Next character scanned
604
605 begin
606 C := Source (Scan_Ptr);
607
608 -- Loop through digits (allowing underlines)
609
610 loop
611 Accumulate_Checksum (C);
612 UI_Int_Value :=
613 UI_Int_Value * 10 + (Character'Pos (C) - Character'Pos ('0'));
614 Scan_Ptr := Scan_Ptr + 1;
615 Scale := Scale - 1;
616 C := Source (Scan_Ptr);
617
618 -- Case of underline encountered
619
620 if C = '_' then
621
622 -- We do not accumulate the '_' in the checksum, so that
623 -- 1_234 is equivalent to 1234, and does not trigger
624 -- compilation for "minimal recompilation" (gnatmake -m).
625
626 loop
627 Scan_Ptr := Scan_Ptr + 1;
628 C := Source (Scan_Ptr);
629 exit when C /= '_';
630 Error_No_Double_Underline;
631 end loop;
632
633 if C not in '0' .. '9' then
634 Error_Digit_Expected;
635 exit;
636 end if;
637
638 else
639 exit when C not in '0' .. '9';
640 end if;
641 end loop;
642 end Scan_Integer;
643
644 -- Start of Processing for Nlit
645
646 begin
647 Base := 10;
648 UI_Base := Uint_10;
649 UI_Int_Value := Uint_0;
650 Based_Literal_Uses_Colon := False;
651 Scale := 0;
652 Scan_Integer;
653 Point_Scanned := False;
654 UI_Num_Value := UI_Int_Value;
655
656 -- Various possibilities now for continuing the literal are period,
657 -- E/e (for exponent), or :/# (for based literal).
658
659 Scale := 0;
660 C := Source (Scan_Ptr);
661
662 if C = '.' then
663
664 -- Scan out point, but do not scan past .. which is a range
665 -- sequence, and must not be eaten up scanning a numeric literal.
666
667 while C = '.' and then Source (Scan_Ptr + 1) /= '.' loop
668 Accumulate_Checksum ('.');
669
670 if Point_Scanned then
671 Error_Msg_S ("duplicate point ignored");
672 end if;
673
674 Point_Scanned := True;
675 Scan_Ptr := Scan_Ptr + 1;
676 C := Source (Scan_Ptr);
677
678 if C not in '0' .. '9' then
679 Error_Msg
680 ("real literal cannot end with point", Scan_Ptr - 1);
681 else
682 Scan_Integer;
683 UI_Num_Value := UI_Int_Value;
684 end if;
685 end loop;
686
687 -- Based literal case. The base is the value we already scanned.
688 -- In the case of colon, we insist that the following character
689 -- is indeed an extended digit or a period. This catches a number
690 -- of common errors, as well as catching the well known tricky
691 -- bug otherwise arising from "x : integer range 1 .. 10:= 6;"
692
693 elsif C = '#'
694 or else (C = ':' and then
695 (Source (Scan_Ptr + 1) = '.'
696 or else
697 Source (Scan_Ptr + 1) in '0' .. '9'
698 or else
699 Source (Scan_Ptr + 1) in 'A' .. 'Z'
700 or else
701 Source (Scan_Ptr + 1) in 'a' .. 'z'))
702 then
703 Accumulate_Checksum (C);
704 Base_Char := C;
705 UI_Base := UI_Int_Value;
706
707 if Base_Char = ':' then
708 Based_Literal_Uses_Colon := True;
709 end if;
710
711 if UI_Base < 2 or else UI_Base > 16 then
712 Error_Msg_SC ("base not 2-16");
713 UI_Base := Uint_16;
714 end if;
715
716 Base := UI_To_Int (UI_Base);
717 Scan_Ptr := Scan_Ptr + 1;
718
719 -- Scan out extended integer [. integer]
720
721 C := Source (Scan_Ptr);
722 UI_Int_Value := Uint_0;
723 Scale := 0;
724
725 loop
726 if C in '0' .. '9' then
727 Accumulate_Checksum (C);
728 Extended_Digit_Value :=
729 Int'(Character'Pos (C)) - Int'(Character'Pos ('0'));
730
731 elsif C in 'A' .. 'F' then
732 Accumulate_Checksum (Character'Val (Character'Pos (C) + 32));
733 Extended_Digit_Value :=
734 Int'(Character'Pos (C)) - Int'(Character'Pos ('A')) + 10;
735
736 elsif C in 'a' .. 'f' then
737 Accumulate_Checksum (C);
738 Extended_Digit_Value :=
739 Int'(Character'Pos (C)) - Int'(Character'Pos ('a')) + 10;
740
741 else
742 Error_Msg_S ("extended digit expected");
743 exit;
744 end if;
745
746 if Extended_Digit_Value >= Base then
747 Error_Msg_S ("digit '>= base");
748 end if;
749
750 UI_Int_Value := UI_Int_Value * UI_Base + Extended_Digit_Value;
751 Scale := Scale - 1;
752 Scan_Ptr := Scan_Ptr + 1;
753 C := Source (Scan_Ptr);
754
755 if C = '_' then
756 loop
757 Accumulate_Checksum ('_');
758 Scan_Ptr := Scan_Ptr + 1;
759 C := Source (Scan_Ptr);
760 exit when C /= '_';
761 Error_No_Double_Underline;
762 end loop;
763
764 elsif C = '.' then
765 Accumulate_Checksum ('.');
766
767 if Point_Scanned then
768 Error_Msg_S ("duplicate point ignored");
769 end if;
770
771 Scan_Ptr := Scan_Ptr + 1;
772 C := Source (Scan_Ptr);
773 Point_Scanned := True;
774 Scale := 0;
775
776 elsif C = Base_Char then
777 Accumulate_Checksum (C);
778 Scan_Ptr := Scan_Ptr + 1;
779 exit;
780
781 elsif C = '#' or else C = ':' then
782 Error_Msg_S ("based number delimiters must match");
783 Scan_Ptr := Scan_Ptr + 1;
784 exit;
785
786 elsif not Identifier_Char (C) then
787 if Base_Char = '#' then
788 Error_Msg_S -- CODEFIX
789 ("missing '#");
790 else
791 Error_Msg_S -- CODEFIX
792 ("missing ':");
793 end if;
794
795 exit;
796 end if;
797
798 end loop;
799
800 UI_Num_Value := UI_Int_Value;
801 end if;
802
803 -- Scan out exponent
804
805 if not Point_Scanned then
806 Scale := 0;
807 UI_Scale := Uint_0;
808 else
809 UI_Scale := UI_From_Int (Scale);
810 end if;
811
812 if Source (Scan_Ptr) = 'e' or else Source (Scan_Ptr) = 'E' then
813 Accumulate_Checksum ('e');
814 Scan_Ptr := Scan_Ptr + 1;
815 Exponent_Is_Negative := False;
816
817 if Source (Scan_Ptr) = '+' then
818 Accumulate_Checksum ('+');
819 Scan_Ptr := Scan_Ptr + 1;
820
821 elsif Source (Scan_Ptr) = '-' then
822 Accumulate_Checksum ('-');
823
824 if not Point_Scanned then
825 Error_Msg_S
826 ("negative exponent not allowed for integer literal");
827 else
828 Exponent_Is_Negative := True;
829 end if;
830
831 Scan_Ptr := Scan_Ptr + 1;
832 end if;
833
834 UI_Int_Value := Uint_0;
835
836 if Source (Scan_Ptr) in '0' .. '9' then
837 Scan_Integer;
838 else
839 Error_Digit_Expected;
840 end if;
841
842 if Exponent_Is_Negative then
843 UI_Scale := UI_Scale - UI_Int_Value;
844 else
845 UI_Scale := UI_Scale + UI_Int_Value;
846 end if;
847 end if;
848
849 -- Case of real literal to be returned
850
851 if Point_Scanned then
852 Token := Tok_Real_Literal;
853 Real_Literal_Value :=
854 UR_From_Components (
855 Num => UI_Num_Value,
856 Den => -UI_Scale,
857 Rbase => Base);
858
859 -- Case of integer literal to be returned
860
861 else
862 Token := Tok_Integer_Literal;
863
864 if UI_Scale = 0 then
865 Int_Literal_Value := UI_Num_Value;
866
867 -- Avoid doing possibly expensive calculations in cases like
868 -- parsing 163E800_000# when semantics will not be done anyway.
869 -- This is especially useful when parsing garbled input.
870
871 elsif Operating_Mode /= Check_Syntax
872 and then (Serious_Errors_Detected = 0 or else Try_Semantics)
873 then
874 Int_Literal_Value := UI_Num_Value * UI_Base ** UI_Scale;
875
876 else
877 Int_Literal_Value := No_Uint;
878 end if;
879 end if;
880
881 if Checksum_Accumulate_Token_Checksum then
882 Accumulate_Token_Checksum;
883 end if;
884
885 return;
886 end Nlit;
887
888 ----------
889 -- Slit --
890 ----------
891
892 procedure Slit is
893
894 Delimiter : Character;
895 -- Delimiter (first character of string)
896
897 C : Character;
898 -- Current source program character
899
900 Code : Char_Code;
901 -- Current character code value
902
903 Err : Boolean;
904 -- Error flag for Scan_Wide call
905
906 String_Start : Source_Ptr;
907 -- Point to first character of string
908
909 procedure Error_Bad_String_Char;
910 -- Signal bad character in string/character literal. On entry
911 -- Scan_Ptr points to the improper character encountered during the
912 -- scan. Scan_Ptr is not modified, so it still points to the bad
913 -- character on return.
914
915 procedure Error_Unterminated_String;
916 -- Procedure called if a line terminator character is encountered
917 -- during scanning a string, meaning that the string is not properly
918 -- terminated.
919
920 procedure Set_String;
921 -- Procedure used to distinguish between string and operator symbol.
922 -- On entry the string has been scanned out, and its characters start
923 -- at Token_Ptr and end one character before Scan_Ptr. On exit Token
924 -- is set to Tok_String_Literal/Tok_Operator_Symbol as appropriate,
925 -- and Token_Node is appropriately initialized. In addition, in the
926 -- operator symbol case, Token_Name is appropriately set, and the
927 -- flags [Wide_]Wide_Character_Found are set appropriately.
928
929 ---------------------------
930 -- Error_Bad_String_Char --
931 ---------------------------
932
933 procedure Error_Bad_String_Char is
934 C : constant Character := Source (Scan_Ptr);
935
936 begin
937 if C = HT then
938 Error_Msg_S ("horizontal tab not allowed in string");
939
940 elsif C = VT or else C = FF then
941 Error_Msg_S ("format effector not allowed in string");
942
943 elsif C in Upper_Half_Character then
944 Error_Msg_S ("(Ada 83) upper half character not allowed");
945
946 else
947 Error_Msg_S ("control character not allowed in string");
948 end if;
949 end Error_Bad_String_Char;
950
951 -------------------------------
952 -- Error_Unterminated_String --
953 -------------------------------
954
955 procedure Error_Unterminated_String is
956 S : Source_Ptr;
957
958 begin
959 -- An interesting little refinement. Consider the following
960 -- examples:
961
962 -- A := "this is an unterminated string;
963 -- A := "this is an unterminated string &
964 -- P(A, "this is a parameter that didn't get terminated);
965 -- P("this is a parameter that didn't get terminated, A);
966
967 -- We fiddle a little to do slightly better placement in these
968 -- cases also if there is white space at the end of the line we
969 -- place the flag at the start of this white space, not at the
970 -- end. Note that we only have to test for blanks, since tabs
971 -- aren't allowed in strings in the first place and would have
972 -- caused an error message.
973
974 -- Two more cases that we treat specially are:
975
976 -- A := "this string uses the wrong terminator'
977 -- A := "this string uses the wrong terminator' &
978
979 -- In these cases we give a different error message as well
980
981 -- We actually reposition the scan pointer to the point where we
982 -- place the flag in these cases, since it seems a better bet on
983 -- the original intention.
984
985 while Source (Scan_Ptr - 1) = ' '
986 or else Source (Scan_Ptr - 1) = '&'
987 loop
988 Scan_Ptr := Scan_Ptr - 1;
989 Unstore_String_Char;
990 end loop;
991
992 -- Check for case of incorrect string terminator, but single quote
993 -- is not considered incorrect if the opening terminator misused
994 -- a single quote (error message already given).
995
996 if Delimiter /= '''
997 and then Source (Scan_Ptr - 1) = '''
998 then
999 Unstore_String_Char;
1000 Error_Msg
1001 ("incorrect string terminator character", Scan_Ptr - 1);
1002 return;
1003 end if;
1004
1005 -- Backup over semicolon or right-paren/semicolon sequence
1006
1007 if Source (Scan_Ptr - 1) = ';' then
1008 Scan_Ptr := Scan_Ptr - 1;
1009 Unstore_String_Char;
1010
1011 if Source (Scan_Ptr - 1) = ')' then
1012 Scan_Ptr := Scan_Ptr - 1;
1013 Unstore_String_Char;
1014 end if;
1015 end if;
1016
1017 -- See if there is a comma in the string, if so, guess that
1018 -- the first comma terminates the string.
1019
1020 S := String_Start;
1021 while S < Scan_Ptr loop
1022 if Source (S) = ',' then
1023 while Scan_Ptr > S loop
1024 Scan_Ptr := Scan_Ptr - 1;
1025 Unstore_String_Char;
1026 end loop;
1027
1028 exit;
1029 end if;
1030
1031 S := S + 1;
1032 end loop;
1033
1034 -- Now we have adjusted the scan pointer, give message
1035
1036 Error_Msg_S -- CODEFIX
1037 ("missing string quote");
1038 end Error_Unterminated_String;
1039
1040 ----------------
1041 -- Set_String --
1042 ----------------
1043
1044 procedure Set_String is
1045 Slen : constant Int := Int (Scan_Ptr - Token_Ptr - 2);
1046 C1 : Character;
1047 C2 : Character;
1048 C3 : Character;
1049
1050 begin
1051 -- Token_Name is currently set to Error_Name. The following
1052 -- section of code resets Token_Name to the proper Name_Op_xx
1053 -- value if the string is a valid operator symbol, otherwise it is
1054 -- left set to Error_Name.
1055
1056 if Slen = 1 then
1057 C1 := Source (Token_Ptr + 1);
1058
1059 case C1 is
1060 when '=' =>
1061 Token_Name := Name_Op_Eq;
1062
1063 when '>' =>
1064 Token_Name := Name_Op_Gt;
1065
1066 when '<' =>
1067 Token_Name := Name_Op_Lt;
1068
1069 when '+' =>
1070 Token_Name := Name_Op_Add;
1071
1072 when '-' =>
1073 Token_Name := Name_Op_Subtract;
1074
1075 when '&' =>
1076 Token_Name := Name_Op_Concat;
1077
1078 when '*' =>
1079 Token_Name := Name_Op_Multiply;
1080
1081 when '/' =>
1082 Token_Name := Name_Op_Divide;
1083
1084 when others =>
1085 null;
1086 end case;
1087
1088 elsif Slen = 2 then
1089 C1 := Source (Token_Ptr + 1);
1090 C2 := Source (Token_Ptr + 2);
1091
1092 if C1 = '*' and then C2 = '*' then
1093 Token_Name := Name_Op_Expon;
1094
1095 elsif C2 = '=' then
1096
1097 if C1 = '/' then
1098 Token_Name := Name_Op_Ne;
1099 elsif C1 = '<' then
1100 Token_Name := Name_Op_Le;
1101 elsif C1 = '>' then
1102 Token_Name := Name_Op_Ge;
1103 end if;
1104
1105 elsif (C1 = 'O' or else C1 = 'o') and then -- OR
1106 (C2 = 'R' or else C2 = 'r')
1107 then
1108 Token_Name := Name_Op_Or;
1109 end if;
1110
1111 elsif Slen = 3 then
1112 C1 := Source (Token_Ptr + 1);
1113 C2 := Source (Token_Ptr + 2);
1114 C3 := Source (Token_Ptr + 3);
1115
1116 if (C1 = 'A' or else C1 = 'a') and then -- AND
1117 (C2 = 'N' or else C2 = 'n') and then
1118 (C3 = 'D' or else C3 = 'd')
1119 then
1120 Token_Name := Name_Op_And;
1121
1122 elsif (C1 = 'A' or else C1 = 'a') and then -- ABS
1123 (C2 = 'B' or else C2 = 'b') and then
1124 (C3 = 'S' or else C3 = 's')
1125 then
1126 Token_Name := Name_Op_Abs;
1127
1128 elsif (C1 = 'M' or else C1 = 'm') and then -- MOD
1129 (C2 = 'O' or else C2 = 'o') and then
1130 (C3 = 'D' or else C3 = 'd')
1131 then
1132 Token_Name := Name_Op_Mod;
1133
1134 elsif (C1 = 'N' or else C1 = 'n') and then -- NOT
1135 (C2 = 'O' or else C2 = 'o') and then
1136 (C3 = 'T' or else C3 = 't')
1137 then
1138 Token_Name := Name_Op_Not;
1139
1140 elsif (C1 = 'R' or else C1 = 'r') and then -- REM
1141 (C2 = 'E' or else C2 = 'e') and then
1142 (C3 = 'M' or else C3 = 'm')
1143 then
1144 Token_Name := Name_Op_Rem;
1145
1146 elsif (C1 = 'X' or else C1 = 'x') and then -- XOR
1147 (C2 = 'O' or else C2 = 'o') and then
1148 (C3 = 'R' or else C3 = 'r')
1149 then
1150 Token_Name := Name_Op_Xor;
1151 end if;
1152
1153 end if;
1154
1155 -- If it is an operator symbol, then Token_Name is set. If it is
1156 -- some other string value, then Token_Name still contains
1157 -- Error_Name.
1158
1159 if Token_Name = Error_Name then
1160 Token := Tok_String_Literal;
1161
1162 else
1163 Token := Tok_Operator_Symbol;
1164 end if;
1165 end Set_String;
1166
1167 -- Start of processing for Slit
1168
1169 begin
1170 -- On entry, Scan_Ptr points to the opening character of the string
1171 -- which is either a percent, double quote, or apostrophe (single
1172 -- quote). The latter case is an error detected by the character
1173 -- literal circuit.
1174
1175 String_Start := Scan_Ptr;
1176
1177 Delimiter := Source (Scan_Ptr);
1178 Accumulate_Checksum (Delimiter);
1179
1180 Start_String;
1181 Wide_Character_Found := False;
1182 Wide_Wide_Character_Found := False;
1183 Scan_Ptr := Scan_Ptr + 1;
1184
1185 -- Loop to scan out characters of string literal
1186
1187 loop
1188 C := Source (Scan_Ptr);
1189
1190 if C = Delimiter then
1191 Accumulate_Checksum (C);
1192 Scan_Ptr := Scan_Ptr + 1;
1193 exit when Source (Scan_Ptr) /= Delimiter;
1194 Code := Get_Char_Code (C);
1195 Accumulate_Checksum (C);
1196 Scan_Ptr := Scan_Ptr + 1;
1197
1198 else
1199 if C = '"' and then Delimiter = '%' then
1200 Error_Msg_S
1201 ("quote not allowed in percent delimited string");
1202 Code := Get_Char_Code (C);
1203 Scan_Ptr := Scan_Ptr + 1;
1204
1205 elsif Start_Of_Wide_Character then
1206 Wptr := Scan_Ptr;
1207 Scan_Wide (Source, Scan_Ptr, Code, Err);
1208
1209 if Err then
1210 Error_Illegal_Wide_Character;
1211 Code := Get_Char_Code (' ');
1212 end if;
1213
1214 Accumulate_Checksum (Code);
1215
1216 -- In Ada 95 mode we allow any wide characters in a string
1217 -- but in Ada 2005, the set of characters allowed has been
1218 -- restricted to graphic characters.
1219
1220 if Ada_Version >= Ada_2005
1221 and then Is_UTF_32_Non_Graphic (UTF_32 (Code))
1222 then
1223 Error_Msg
1224 ("(Ada 2005) non-graphic character not permitted " &
1225 "in string literal", Wptr);
1226 end if;
1227
1228 else
1229 Accumulate_Checksum (C);
1230
1231 if C not in Graphic_Character then
1232 if C in Line_Terminator then
1233 Error_Unterminated_String;
1234 exit;
1235
1236 elsif C in Upper_Half_Character then
1237 if Ada_Version = Ada_83 then
1238 Error_Bad_String_Char;
1239 end if;
1240
1241 else
1242 Error_Bad_String_Char;
1243 end if;
1244 end if;
1245
1246 Code := Get_Char_Code (C);
1247 Scan_Ptr := Scan_Ptr + 1;
1248 end if;
1249 end if;
1250
1251 Store_String_Char (Code);
1252
1253 if not In_Character_Range (Code) then
1254 if In_Wide_Character_Range (Code) then
1255 Wide_Character_Found := True;
1256 else
1257 Wide_Wide_Character_Found := True;
1258 end if;
1259 end if;
1260 end loop;
1261
1262 String_Literal_Id := End_String;
1263 Set_String;
1264 return;
1265 end Slit;
1266
1267 ----------------------------------
1268 -- Skip_Other_Format_Characters --
1269 ----------------------------------
1270
1271 procedure Skip_Other_Format_Characters is
1272 P : Source_Ptr;
1273 Code : Char_Code;
1274 Err : Boolean;
1275
1276 begin
1277 while Start_Of_Wide_Character loop
1278 P := Scan_Ptr;
1279 Scan_Wide (Source, Scan_Ptr, Code, Err);
1280
1281 if not Is_UTF_32_Other (UTF_32 (Code)) then
1282 Scan_Ptr := P;
1283 return;
1284 end if;
1285 end loop;
1286 end Skip_Other_Format_Characters;
1287
1288 -----------------------------
1289 -- Start_Of_Wide_Character --
1290 -----------------------------
1291
1292 function Start_Of_Wide_Character return Boolean is
1293 C : constant Character := Source (Scan_Ptr);
1294
1295 begin
1296 -- ESC encoding method with ESC present
1297
1298 if C = ESC
1299 and then Wide_Character_Encoding_Method in WC_ESC_Encoding_Method
1300 then
1301 return True;
1302
1303 -- Upper half character with upper half encoding
1304
1305 elsif C in Upper_Half_Character and then Upper_Half_Encoding then
1306 return True;
1307
1308 -- Brackets encoding
1309
1310 elsif C = '['
1311 and then Source (Scan_Ptr + 1) = '"'
1312 and then Identifier_Char (Source (Scan_Ptr + 2))
1313 then
1314 return True;
1315
1316 -- Not the start of a wide character
1317
1318 else
1319 return False;
1320 end if;
1321 end Start_Of_Wide_Character;
1322
1323 -- Start of processing for Scan
1324
1325 begin
1326 Prev_Token := Token;
1327 Prev_Token_Ptr := Token_Ptr;
1328 Token_Name := Error_Name;
1329
1330 -- The following loop runs more than once only if a format effector
1331 -- (tab, vertical tab, form feed, line feed, carriage return) is
1332 -- encountered and skipped, or some error situation, such as an
1333 -- illegal character, is encountered.
1334
1335 <<Scan_Next_Character>>
1336
1337 loop
1338 -- Skip past blanks, loop is opened up for speed
1339
1340 while Source (Scan_Ptr) = ' ' loop
1341 if Source (Scan_Ptr + 1) /= ' ' then
1342 Scan_Ptr := Scan_Ptr + 1;
1343 exit;
1344 end if;
1345
1346 if Source (Scan_Ptr + 2) /= ' ' then
1347 Scan_Ptr := Scan_Ptr + 2;
1348 exit;
1349 end if;
1350
1351 if Source (Scan_Ptr + 3) /= ' ' then
1352 Scan_Ptr := Scan_Ptr + 3;
1353 exit;
1354 end if;
1355
1356 if Source (Scan_Ptr + 4) /= ' ' then
1357 Scan_Ptr := Scan_Ptr + 4;
1358 exit;
1359 end if;
1360
1361 if Source (Scan_Ptr + 5) /= ' ' then
1362 Scan_Ptr := Scan_Ptr + 5;
1363 exit;
1364 end if;
1365
1366 if Source (Scan_Ptr + 6) /= ' ' then
1367 Scan_Ptr := Scan_Ptr + 6;
1368 exit;
1369 end if;
1370
1371 if Source (Scan_Ptr + 7) /= ' ' then
1372 Scan_Ptr := Scan_Ptr + 7;
1373 exit;
1374 end if;
1375
1376 Scan_Ptr := Scan_Ptr + 8;
1377 end loop;
1378
1379 -- We are now at a non-blank character, which is the first character
1380 -- of the token we will scan, and hence the value of Token_Ptr.
1381
1382 Token_Ptr := Scan_Ptr;
1383
1384 -- Here begins the main case statement which transfers control on the
1385 -- basis of the non-blank character we have encountered.
1386
1387 case Source (Scan_Ptr) is
1388
1389 -- Line terminator characters
1390
1391 when CR | LF | FF | VT =>
1392 goto Scan_Line_Terminator;
1393
1394 -- Horizontal tab, just skip past it
1395
1396 when HT =>
1397 if Style_Check then
1398 Style.Check_HT;
1399 end if;
1400
1401 Scan_Ptr := Scan_Ptr + 1;
1402
1403 -- End of file character, treated as an end of file only if it is
1404 -- the last character in the buffer, otherwise it is ignored.
1405
1406 when EOF =>
1407 if Scan_Ptr = Source_Last (Current_Source_File) then
1408 Check_End_Of_Line;
1409
1410 if Style_Check then
1411 Style.Check_EOF;
1412 end if;
1413
1414 Token := Tok_EOF;
1415 return;
1416 else
1417 Scan_Ptr := Scan_Ptr + 1;
1418 end if;
1419
1420 -- Ampersand
1421
1422 when '&' =>
1423 Accumulate_Checksum ('&');
1424
1425 if Source (Scan_Ptr + 1) = '&' then
1426 Error_Msg_S -- CODEFIX
1427 ("'&'& should be `AND THEN`");
1428 Scan_Ptr := Scan_Ptr + 2;
1429 Token := Tok_And;
1430 return;
1431
1432 else
1433 Scan_Ptr := Scan_Ptr + 1;
1434 Token := Tok_Ampersand;
1435 return;
1436 end if;
1437
1438 -- Asterisk (can be multiplication operator or double asterisk which
1439 -- is the exponentiation compound delimiter).
1440
1441 when '*' =>
1442 Accumulate_Checksum ('*');
1443
1444 if Source (Scan_Ptr + 1) = '*' then
1445 Accumulate_Checksum ('*');
1446 Scan_Ptr := Scan_Ptr + 2;
1447 Token := Tok_Double_Asterisk;
1448 return;
1449
1450 else
1451 Scan_Ptr := Scan_Ptr + 1;
1452 Token := Tok_Asterisk;
1453 return;
1454 end if;
1455
1456 -- Colon, which can either be an isolated colon, or part of an
1457 -- assignment compound delimiter.
1458
1459 when ':' =>
1460 Accumulate_Checksum (':');
1461
1462 if Double_Char_Token ('=') then
1463 Token := Tok_Colon_Equal;
1464
1465 if Style_Check then
1466 Style.Check_Colon_Equal;
1467 end if;
1468
1469 return;
1470
1471 elsif Source (Scan_Ptr + 1) = '-'
1472 and then Source (Scan_Ptr + 2) /= '-'
1473 then
1474 Token := Tok_Colon_Equal;
1475 Error_Msg -- CODEFIX
1476 (":- should be :=", Scan_Ptr);
1477 Scan_Ptr := Scan_Ptr + 2;
1478 return;
1479
1480 else
1481 Scan_Ptr := Scan_Ptr + 1;
1482 Token := Tok_Colon;
1483
1484 if Style_Check then
1485 Style.Check_Colon;
1486 end if;
1487
1488 return;
1489 end if;
1490
1491 -- Left parenthesis
1492
1493 when '(' =>
1494 Accumulate_Checksum ('(');
1495 Scan_Ptr := Scan_Ptr + 1;
1496 Token := Tok_Left_Paren;
1497
1498 if Style_Check then
1499 Style.Check_Left_Paren;
1500 end if;
1501
1502 return;
1503
1504 -- Left bracket
1505
1506 when '[' =>
1507 if Source (Scan_Ptr + 1) = '"' then
1508 goto Scan_Wide_Character;
1509
1510 else
1511 Error_Msg_S ("illegal character, replaced by ""(""");
1512 Scan_Ptr := Scan_Ptr + 1;
1513 Token := Tok_Left_Paren;
1514 return;
1515 end if;
1516
1517 -- Left brace
1518
1519 when '{' =>
1520 Error_Msg_S ("illegal character, replaced by ""(""");
1521 Scan_Ptr := Scan_Ptr + 1;
1522 Token := Tok_Left_Paren;
1523 return;
1524
1525 -- Comma
1526
1527 when ',' =>
1528 Accumulate_Checksum (',');
1529 Scan_Ptr := Scan_Ptr + 1;
1530 Token := Tok_Comma;
1531
1532 if Style_Check then
1533 Style.Check_Comma;
1534 end if;
1535
1536 return;
1537
1538 -- Dot, which is either an isolated period, or part of a double dot
1539 -- compound delimiter sequence. We also check for the case of a
1540 -- digit following the period, to give a better error message.
1541
1542 when '.' =>
1543 Accumulate_Checksum ('.');
1544
1545 if Double_Char_Token ('.') then
1546 Token := Tok_Dot_Dot;
1547
1548 if Style_Check then
1549 Style.Check_Dot_Dot;
1550 end if;
1551
1552 return;
1553
1554 elsif Source (Scan_Ptr + 1) in '0' .. '9' then
1555 Error_Msg_S ("numeric literal cannot start with point");
1556 Scan_Ptr := Scan_Ptr + 1;
1557
1558 else
1559 Scan_Ptr := Scan_Ptr + 1;
1560 Token := Tok_Dot;
1561 return;
1562 end if;
1563
1564 -- Equal, which can either be an equality operator, or part of the
1565 -- arrow (=>) compound delimiter.
1566
1567 when '=' =>
1568 Accumulate_Checksum ('=');
1569
1570 if Double_Char_Token ('>') then
1571 Token := Tok_Arrow;
1572
1573 if Style_Check then
1574 Style.Check_Arrow (Inside_Depends);
1575 end if;
1576
1577 return;
1578
1579 elsif Source (Scan_Ptr + 1) = '=' then
1580 Error_Msg_S -- CODEFIX
1581 ("== should be =");
1582 Scan_Ptr := Scan_Ptr + 1;
1583 end if;
1584
1585 Scan_Ptr := Scan_Ptr + 1;
1586 Token := Tok_Equal;
1587 return;
1588
1589 -- Greater than, which can be a greater than operator, greater than
1590 -- or equal operator, or first character of a right label bracket.
1591
1592 when '>' =>
1593 Accumulate_Checksum ('>');
1594
1595 if Double_Char_Token ('=') then
1596 Token := Tok_Greater_Equal;
1597 return;
1598
1599 elsif Double_Char_Token ('>') then
1600 Token := Tok_Greater_Greater;
1601 return;
1602
1603 else
1604 Scan_Ptr := Scan_Ptr + 1;
1605 Token := Tok_Greater;
1606 return;
1607 end if;
1608
1609 -- Less than, which can be a less than operator, less than or equal
1610 -- operator, or the first character of a left label bracket, or the
1611 -- first character of a box (<>) compound delimiter.
1612
1613 when '<' =>
1614 Accumulate_Checksum ('<');
1615
1616 if Double_Char_Token ('=') then
1617 Token := Tok_Less_Equal;
1618 return;
1619
1620 elsif Double_Char_Token ('>') then
1621 Token := Tok_Box;
1622
1623 if Style_Check then
1624 Style.Check_Box;
1625 end if;
1626
1627 return;
1628
1629 elsif Double_Char_Token ('<') then
1630 Token := Tok_Less_Less;
1631 return;
1632
1633 else
1634 Scan_Ptr := Scan_Ptr + 1;
1635 Token := Tok_Less;
1636 return;
1637 end if;
1638
1639 -- Minus, which is either a subtraction operator, or the first
1640 -- character of double minus starting a comment
1641
1642 when '-' => Minus_Case : begin
1643 if Source (Scan_Ptr + 1) = '>' then
1644 Error_Msg_S ("invalid token");
1645 Scan_Ptr := Scan_Ptr + 2;
1646 Token := Tok_Arrow;
1647 return;
1648
1649 elsif Source (Scan_Ptr + 1) /= '-' then
1650 Accumulate_Checksum ('-');
1651 Scan_Ptr := Scan_Ptr + 1;
1652 Token := Tok_Minus;
1653 return;
1654
1655 -- Comment
1656
1657 else -- Source (Scan_Ptr + 1) = '-' then
1658 if Style_Check then
1659 Style.Check_Comment;
1660 end if;
1661
1662 Scan_Ptr := Scan_Ptr + 2;
1663
1664 -- If we are in preprocessor mode with Replace_In_Comments set,
1665 -- then we return the "--" as a token on its own.
1666
1667 if Replace_In_Comments then
1668 Token := Tok_Comment;
1669 return;
1670 end if;
1671
1672 -- Otherwise scan out the comment
1673
1674 Start_Of_Comment := Scan_Ptr;
1675
1676 -- Loop to scan comment (this loop runs more than once only if
1677 -- a horizontal tab or other non-graphic character is scanned)
1678
1679 loop
1680 -- Scan to non graphic character (opened up for speed)
1681
1682 -- Note that we just eat left brackets, which means that
1683 -- bracket notation cannot be used for end of line
1684 -- characters in comments. This seems a reasonable choice,
1685 -- since no one would ever use brackets notation in a real
1686 -- program in this situation, and if we allow brackets
1687 -- notation, we forbid some valid comments which contain a
1688 -- brackets sequence that happens to match an end of line
1689 -- character.
1690
1691 loop
1692 exit when Source (Scan_Ptr) not in Graphic_Character;
1693 Scan_Ptr := Scan_Ptr + 1;
1694 exit when Source (Scan_Ptr) not in Graphic_Character;
1695 Scan_Ptr := Scan_Ptr + 1;
1696 exit when Source (Scan_Ptr) not in Graphic_Character;
1697 Scan_Ptr := Scan_Ptr + 1;
1698 exit when Source (Scan_Ptr) not in Graphic_Character;
1699 Scan_Ptr := Scan_Ptr + 1;
1700 exit when Source (Scan_Ptr) not in Graphic_Character;
1701 Scan_Ptr := Scan_Ptr + 1;
1702 end loop;
1703
1704 -- Keep going if horizontal tab
1705
1706 if Source (Scan_Ptr) = HT then
1707 if Style_Check then
1708 Style.Check_HT;
1709 end if;
1710
1711 Scan_Ptr := Scan_Ptr + 1;
1712
1713 -- Terminate scan of comment if line terminator
1714
1715 elsif Source (Scan_Ptr) in Line_Terminator then
1716 exit;
1717
1718 -- Terminate scan of comment if end of file encountered
1719 -- (embedded EOF character or real last character in file)
1720
1721 elsif Source (Scan_Ptr) = EOF then
1722 exit;
1723
1724 -- If we have a wide character, we have to scan it out,
1725 -- because it might be a legitimate line terminator
1726
1727 elsif Start_Of_Wide_Character then
1728 declare
1729 Wptr : constant Source_Ptr := Scan_Ptr;
1730 Code : Char_Code;
1731 Err : Boolean;
1732
1733 begin
1734 Scan_Wide (Source, Scan_Ptr, Code, Err);
1735
1736 -- If not well formed wide character, then just skip
1737 -- past it and ignore it.
1738
1739 if Err then
1740 Scan_Ptr := Wptr + 1;
1741
1742 -- If UTF_32 terminator, terminate comment scan
1743
1744 elsif Is_UTF_32_Line_Terminator (UTF_32 (Code)) then
1745 Scan_Ptr := Wptr;
1746 exit;
1747 end if;
1748 end;
1749
1750 -- Keep going if character in 80-FF range, or is ESC. These
1751 -- characters are allowed in comments by RM-2.1(1), 2.7(2).
1752 -- They are allowed even in Ada 83 mode according to the
1753 -- approved AI. ESC was added to the AI in June 93.
1754
1755 elsif Source (Scan_Ptr) in Upper_Half_Character
1756 or else Source (Scan_Ptr) = ESC
1757 then
1758 Scan_Ptr := Scan_Ptr + 1;
1759
1760 -- Otherwise we have an illegal comment character
1761
1762 else
1763 Error_Illegal_Character;
1764 end if;
1765 end loop;
1766
1767 -- Note that, except when comments are tokens, we do NOT
1768 -- execute a return here, instead we fall through to reexecute
1769 -- the scan loop to look for a token.
1770
1771 if Comment_Is_Token then
1772 Name_Len := Integer (Scan_Ptr - Start_Of_Comment);
1773 Name_Buffer (1 .. Name_Len) :=
1774 String (Source (Start_Of_Comment .. Scan_Ptr - 1));
1775 Comment_Id := Name_Find;
1776 Token := Tok_Comment;
1777 return;
1778 end if;
1779
1780 -- If the SPARK restriction is set for this unit, then generate
1781 -- a token Tok_SPARK_Hide for a SPARK HIDE directive.
1782
1783 if Restriction_Check_Required (SPARK_05)
1784 and then Source (Start_Of_Comment) = '#'
1785 then
1786 declare
1787 Scan_SPARK_Ptr : Source_Ptr;
1788
1789 begin
1790 Scan_SPARK_Ptr := Start_Of_Comment + 1;
1791
1792 -- Scan out blanks
1793
1794 while Source (Scan_SPARK_Ptr) = ' '
1795 or else Source (Scan_SPARK_Ptr) = HT
1796 loop
1797 Scan_SPARK_Ptr := Scan_SPARK_Ptr + 1;
1798 end loop;
1799
1800 -- Recognize HIDE directive. SPARK input cannot be
1801 -- encoded as wide characters, so only deal with
1802 -- lower/upper case.
1803
1804 if (Source (Scan_SPARK_Ptr) = 'h'
1805 or else Source (Scan_SPARK_Ptr) = 'H')
1806 and then (Source (Scan_SPARK_Ptr + 1) = 'i'
1807 or else Source (Scan_SPARK_Ptr + 1) = 'I')
1808 and then (Source (Scan_SPARK_Ptr + 2) = 'd'
1809 or else Source (Scan_SPARK_Ptr + 2) = 'D')
1810 and then (Source (Scan_SPARK_Ptr + 3) = 'e'
1811 or else Source (Scan_SPARK_Ptr + 3) = 'E')
1812 and then (Source (Scan_SPARK_Ptr + 4) = ' '
1813 or else Source (Scan_SPARK_Ptr + 4) = HT)
1814 then
1815 Token := Tok_SPARK_Hide;
1816 return;
1817 end if;
1818 end;
1819 end if;
1820 end if;
1821 end Minus_Case;
1822
1823 -- Double quote or percent starting a string literal
1824
1825 when '"' | '%' =>
1826 Slit;
1827 Post_Scan;
1828 return;
1829
1830 -- Apostrophe. This can either be the start of a character literal,
1831 -- or an isolated apostrophe used in a qualified expression or an
1832 -- attribute. We treat it as a character literal if it does not
1833 -- follow a right parenthesis, identifier, the keyword ALL or
1834 -- a literal. This means that we correctly treat constructs like:
1835
1836 -- A := CHARACTER'('A');
1837
1838 -- Note that RM-2.2(7) does not require a separator between
1839 -- "CHARACTER" and "'" in the above.
1840
1841 when ''' => Char_Literal_Case : declare
1842 Code : Char_Code;
1843 Err : Boolean;
1844
1845 begin
1846 Accumulate_Checksum (''');
1847 Scan_Ptr := Scan_Ptr + 1;
1848
1849 -- Here is where we make the test to distinguish the cases. Treat
1850 -- as apostrophe if previous token is an identifier, right paren
1851 -- or the reserved word "all" (latter case as in A.all'Address)
1852 -- (or the reserved word "project" in project files). Also treat
1853 -- it as apostrophe after a literal (this catches some legitimate
1854 -- cases, like A."abs"'Address, and also gives better error
1855 -- behavior for impossible cases like 123'xxx).
1856
1857 if Prev_Token = Tok_Identifier
1858 or else Prev_Token = Tok_Right_Paren
1859 or else Prev_Token = Tok_All
1860 or else Prev_Token = Tok_Project
1861 or else Prev_Token in Token_Class_Literal
1862 then
1863 Token := Tok_Apostrophe;
1864
1865 if Style_Check then
1866 Style.Check_Apostrophe;
1867 end if;
1868
1869 return;
1870
1871 -- Otherwise the apostrophe starts a character literal
1872
1873 else
1874 -- Case of wide character literal
1875
1876 if Start_Of_Wide_Character then
1877 Wptr := Scan_Ptr;
1878 Scan_Wide (Source, Scan_Ptr, Code, Err);
1879 Accumulate_Checksum (Code);
1880
1881 if Err then
1882 Error_Illegal_Wide_Character;
1883 Code := Character'Pos (' ');
1884
1885 -- In Ada 95 mode we allow any wide character in a character
1886 -- literal, but in Ada 2005, the set of characters allowed
1887 -- is restricted to graphic characters.
1888
1889 elsif Ada_Version >= Ada_2005
1890 and then Is_UTF_32_Non_Graphic (UTF_32 (Code))
1891 then
1892 Error_Msg -- CODEFIX????
1893 ("(Ada 2005) non-graphic character not permitted " &
1894 "in character literal", Wptr);
1895 end if;
1896
1897 if Source (Scan_Ptr) /= ''' then
1898 Error_Msg_S ("missing apostrophe");
1899 else
1900 Scan_Ptr := Scan_Ptr + 1;
1901 end if;
1902
1903 -- If we do not find a closing quote in the expected place then
1904 -- assume that we have a misguided attempt at a string literal.
1905
1906 -- However, if previous token is RANGE, then we return an
1907 -- apostrophe instead since this gives better error recovery
1908
1909 elsif Source (Scan_Ptr + 1) /= ''' then
1910 if Prev_Token = Tok_Range then
1911 Token := Tok_Apostrophe;
1912 return;
1913
1914 else
1915 Scan_Ptr := Scan_Ptr - 1;
1916 Error_Msg_S
1917 ("strings are delimited by double quote character");
1918 Slit;
1919 Post_Scan;
1920 return;
1921 end if;
1922
1923 -- Otherwise we have a (non-wide) character literal
1924
1925 else
1926 Accumulate_Checksum (Source (Scan_Ptr));
1927
1928 if Source (Scan_Ptr) not in Graphic_Character then
1929 if Source (Scan_Ptr) in Upper_Half_Character then
1930 if Ada_Version = Ada_83 then
1931 Error_Illegal_Character;
1932 end if;
1933
1934 else
1935 Error_Illegal_Character;
1936 end if;
1937 end if;
1938
1939 Code := Get_Char_Code (Source (Scan_Ptr));
1940 Scan_Ptr := Scan_Ptr + 2;
1941 end if;
1942
1943 -- Fall through here with Scan_Ptr updated past the closing
1944 -- quote, and Code set to the Char_Code value for the literal
1945
1946 Accumulate_Checksum (''');
1947 Token := Tok_Char_Literal;
1948 Set_Character_Literal_Name (Code);
1949 Token_Name := Name_Find;
1950 Character_Code := Code;
1951 Post_Scan;
1952 return;
1953 end if;
1954 end Char_Literal_Case;
1955
1956 -- Right parenthesis
1957
1958 when ')' =>
1959 Accumulate_Checksum (')');
1960 Scan_Ptr := Scan_Ptr + 1;
1961 Token := Tok_Right_Paren;
1962
1963 if Style_Check then
1964 Style.Check_Right_Paren;
1965 end if;
1966
1967 return;
1968
1969 -- Right bracket or right brace, treated as right paren
1970
1971 when ']' | '}' =>
1972 Error_Msg_S ("illegal character, replaced by "")""");
1973 Scan_Ptr := Scan_Ptr + 1;
1974 Token := Tok_Right_Paren;
1975 return;
1976
1977 -- Slash (can be division operator or first character of not equal)
1978
1979 when '/' =>
1980 Accumulate_Checksum ('/');
1981
1982 if Double_Char_Token ('=') then
1983 Token := Tok_Not_Equal;
1984 return;
1985 else
1986 Scan_Ptr := Scan_Ptr + 1;
1987 Token := Tok_Slash;
1988 return;
1989 end if;
1990
1991 -- Semicolon
1992
1993 when ';' =>
1994 Accumulate_Checksum (';');
1995 Scan_Ptr := Scan_Ptr + 1;
1996 Token := Tok_Semicolon;
1997
1998 if Style_Check then
1999 Style.Check_Semicolon;
2000 end if;
2001
2002 return;
2003
2004 -- Vertical bar
2005
2006 when '|' => Vertical_Bar_Case : begin
2007 Accumulate_Checksum ('|');
2008
2009 -- Special check for || to give nice message
2010
2011 if Source (Scan_Ptr + 1) = '|' then
2012 Error_Msg_S -- CODEFIX
2013 ("""'|'|"" should be `OR ELSE`");
2014 Scan_Ptr := Scan_Ptr + 2;
2015 Token := Tok_Or;
2016 return;
2017
2018 else
2019 Scan_Ptr := Scan_Ptr + 1;
2020 Token := Tok_Vertical_Bar;
2021
2022 if Style_Check then
2023 Style.Check_Vertical_Bar;
2024 end if;
2025
2026 Post_Scan;
2027 return;
2028 end if;
2029 end Vertical_Bar_Case;
2030
2031 -- Exclamation, replacement character for vertical bar
2032
2033 when '!' => Exclamation_Case : begin
2034 Accumulate_Checksum ('!');
2035
2036 if Source (Scan_Ptr + 1) = '=' then
2037 Error_Msg_S -- CODEFIX
2038 ("'!= should be /=");
2039 Scan_Ptr := Scan_Ptr + 2;
2040 Token := Tok_Not_Equal;
2041 return;
2042
2043 else
2044 Scan_Ptr := Scan_Ptr + 1;
2045 Token := Tok_Vertical_Bar;
2046 Post_Scan;
2047 return;
2048 end if;
2049 end Exclamation_Case;
2050
2051 -- Plus
2052
2053 when '+' => Plus_Case : begin
2054 Accumulate_Checksum ('+');
2055 Scan_Ptr := Scan_Ptr + 1;
2056 Token := Tok_Plus;
2057 return;
2058 end Plus_Case;
2059
2060 -- Digits starting a numeric literal
2061
2062 when '0' .. '9' =>
2063
2064 -- First a bit of a scan ahead to see if we have a case of an
2065 -- identifier starting with a digit (remembering exponent case).
2066
2067 declare
2068 C : constant Character := Source (Scan_Ptr + 1);
2069
2070 begin
2071 -- OK literal if digit followed by digit or underscore
2072
2073 if C in '0' .. '9' or else C = '_' then
2074 null;
2075
2076 -- OK literal if digit not followed by identifier char
2077
2078 elsif not Identifier_Char (C) then
2079 null;
2080
2081 -- OK literal if digit followed by e/E followed by digit/sign.
2082 -- We also allow underscore after the E, which is an error, but
2083 -- better handled by Nlit than deciding this is an identifier.
2084
2085 elsif (C = 'e' or else C = 'E')
2086 and then (Source (Scan_Ptr + 2) in '0' .. '9'
2087 or else Source (Scan_Ptr + 2) = '+'
2088 or else Source (Scan_Ptr + 2) = '-'
2089 or else Source (Scan_Ptr + 2) = '_')
2090 then
2091 null;
2092
2093 -- Here we have what really looks like an identifier that
2094 -- starts with a digit, so give error msg.
2095
2096 else
2097 Error_Msg_S ("identifier may not start with digit");
2098 Name_Len := 1;
2099 Underline_Found := False;
2100 Name_Buffer (1) := Source (Scan_Ptr);
2101 Accumulate_Checksum (Name_Buffer (1));
2102 Scan_Ptr := Scan_Ptr + 1;
2103 goto Scan_Identifier;
2104 end if;
2105 end;
2106
2107 -- Here we have an OK integer literal
2108
2109 Nlit;
2110
2111 -- Check for proper delimiter, ignoring other format characters
2112
2113 Skip_Other_Format_Characters;
2114
2115 if Identifier_Char (Source (Scan_Ptr)) then
2116 Error_Msg_S
2117 ("delimiter required between literal and identifier");
2118 end if;
2119
2120 Post_Scan;
2121 return;
2122
2123 -- Lower case letters
2124
2125 when 'a' .. 'z' =>
2126 Name_Len := 1;
2127 Underline_Found := False;
2128 Name_Buffer (1) := Source (Scan_Ptr);
2129 Accumulate_Checksum (Name_Buffer (1));
2130 Scan_Ptr := Scan_Ptr + 1;
2131 goto Scan_Identifier;
2132
2133 -- Upper case letters
2134
2135 when 'A' .. 'Z' =>
2136 Name_Len := 1;
2137 Underline_Found := False;
2138 Name_Buffer (1) :=
2139 Character'Val (Character'Pos (Source (Scan_Ptr)) + 32);
2140 Accumulate_Checksum (Name_Buffer (1));
2141 Scan_Ptr := Scan_Ptr + 1;
2142 goto Scan_Identifier;
2143
2144 -- Underline character
2145
2146 when '_' =>
2147 if Special_Characters ('_') then
2148 Token_Ptr := Scan_Ptr;
2149 Scan_Ptr := Scan_Ptr + 1;
2150 Token := Tok_Special;
2151 Special_Character := '_';
2152 return;
2153 end if;
2154
2155 Error_Msg_S ("identifier cannot start with underline");
2156 Name_Len := 1;
2157 Name_Buffer (1) := '_';
2158 Scan_Ptr := Scan_Ptr + 1;
2159 Underline_Found := False;
2160 goto Scan_Identifier;
2161
2162 -- Space (not possible, because we scanned past blanks)
2163
2164 when ' ' =>
2165 raise Program_Error;
2166
2167 -- Characters in top half of ASCII 8-bit chart
2168
2169 when Upper_Half_Character =>
2170
2171 -- Wide character case
2172
2173 if Upper_Half_Encoding then
2174 goto Scan_Wide_Character;
2175
2176 -- Otherwise we have OK Latin-1 character
2177
2178 else
2179 -- Upper half characters may possibly be identifier letters
2180 -- but can never be digits, so Identifier_Char can be used to
2181 -- test for a valid start of identifier character.
2182
2183 if Identifier_Char (Source (Scan_Ptr)) then
2184 Name_Len := 0;
2185 Underline_Found := False;
2186 goto Scan_Identifier;
2187 else
2188 Error_Illegal_Character;
2189 end if;
2190 end if;
2191
2192 when ESC =>
2193
2194 -- ESC character, possible start of identifier if wide characters
2195 -- using ESC encoding are allowed in identifiers, which we can
2196 -- tell by looking at the Identifier_Char flag for ESC, which is
2197 -- only true if these conditions are met. In Ada 2005 mode, may
2198 -- also be valid UTF_32 space or line terminator character.
2199
2200 if Identifier_Char (ESC) then
2201 Name_Len := 0;
2202 goto Scan_Wide_Character;
2203 else
2204 Error_Illegal_Character;
2205 end if;
2206
2207 -- Invalid control characters
2208
2209 when NUL | SOH | STX | ETX | EOT | ENQ | ACK | BEL | BS | ASCII.SO |
2210 SI | DLE | DC1 | DC2 | DC3 | DC4 | NAK | SYN | ETB | CAN |
2211 EM | FS | GS | RS | US | DEL
2212 =>
2213 Error_Illegal_Character;
2214
2215 -- Invalid graphic characters
2216
2217 when '#' | '$' | '?' | '@' | '`' | '\' | '^' | '~' =>
2218
2219 -- If Set_Special_Character has been called for this character,
2220 -- set Scans.Special_Character and return a Special token.
2221
2222 if Special_Characters (Source (Scan_Ptr)) then
2223 Token_Ptr := Scan_Ptr;
2224 Token := Tok_Special;
2225 Special_Character := Source (Scan_Ptr);
2226 Scan_Ptr := Scan_Ptr + 1;
2227 return;
2228
2229 -- Check for something looking like a preprocessor directive
2230
2231 elsif Source (Scan_Ptr) = '#'
2232 and then (Source (Scan_Ptr + 1 .. Scan_Ptr + 2) = "if"
2233 or else
2234 Source (Scan_Ptr + 1 .. Scan_Ptr + 5) = "elsif"
2235 or else
2236 Source (Scan_Ptr + 1 .. Scan_Ptr + 4) = "else"
2237 or else
2238 Source (Scan_Ptr + 1 .. Scan_Ptr + 3) = "end")
2239 then
2240 Error_Msg_S
2241 ("preprocessor directive ignored, preprocessor not active");
2242
2243 -- Skip to end of line
2244
2245 loop
2246 if Source (Scan_Ptr) in Graphic_Character
2247 or else
2248 Source (Scan_Ptr) = HT
2249 then
2250 Scan_Ptr := Scan_Ptr + 1;
2251
2252 -- Done if line terminator or EOF
2253
2254 elsif Source (Scan_Ptr) in Line_Terminator
2255 or else
2256 Source (Scan_Ptr) = EOF
2257 then
2258 exit;
2259
2260 -- If we have a wide character, we have to scan it out,
2261 -- because it might be a legitimate line terminator
2262
2263 elsif Start_Of_Wide_Character then
2264 declare
2265 Wptr : constant Source_Ptr := Scan_Ptr;
2266 Code : Char_Code;
2267 Err : Boolean;
2268
2269 begin
2270 Scan_Wide (Source, Scan_Ptr, Code, Err);
2271
2272 -- If not well formed wide character, then just skip
2273 -- past it and ignore it.
2274
2275 if Err then
2276 Scan_Ptr := Wptr + 1;
2277
2278 -- If UTF_32 terminator, terminate comment scan
2279
2280 elsif Is_UTF_32_Line_Terminator (UTF_32 (Code)) then
2281 Scan_Ptr := Wptr;
2282 exit;
2283 end if;
2284 end;
2285
2286 -- Else keep going (don't worry about bad comment chars
2287 -- in this context, we just want to find the end of line.
2288
2289 else
2290 Scan_Ptr := Scan_Ptr + 1;
2291 end if;
2292 end loop;
2293
2294 -- Otherwise, this is an illegal character
2295
2296 else
2297 Error_Illegal_Character;
2298 end if;
2299
2300 -- End switch on non-blank character
2301
2302 end case;
2303
2304 -- End loop past format effectors. The exit from this loop is by
2305 -- executing a return statement following completion of token scan
2306 -- (control never falls out of this loop to the code which follows)
2307
2308 end loop;
2309
2310 -- Wide_Character scanning routine. On entry we have encountered the
2311 -- initial character of a wide character sequence.
2312
2313 <<Scan_Wide_Character>>
2314
2315 declare
2316 Code : Char_Code;
2317 Cat : Category;
2318 Err : Boolean;
2319
2320 begin
2321 Wptr := Scan_Ptr;
2322 Scan_Wide (Source, Scan_Ptr, Code, Err);
2323
2324 -- If bad wide character, signal error and continue scan
2325
2326 if Err then
2327 Error_Illegal_Wide_Character;
2328 goto Scan_Next_Character;
2329 end if;
2330
2331 Cat := Get_Category (UTF_32 (Code));
2332
2333 -- If OK letter, reset scan ptr and go scan identifier
2334
2335 if Is_UTF_32_Letter (Cat) then
2336 Scan_Ptr := Wptr;
2337 Name_Len := 0;
2338 Underline_Found := False;
2339 goto Scan_Identifier;
2340
2341 -- If OK wide space, ignore and keep scanning (we do not include
2342 -- any ignored spaces in checksum)
2343
2344 elsif Is_UTF_32_Space (Cat) then
2345 goto Scan_Next_Character;
2346
2347 -- If other format character, ignore and keep scanning (again we
2348 -- do not include in the checksum) (this is for AI-0079).
2349
2350 elsif Is_UTF_32_Other (Cat) then
2351 goto Scan_Next_Character;
2352
2353 -- If OK wide line terminator, terminate current line
2354
2355 elsif Is_UTF_32_Line_Terminator (UTF_32 (Code)) then
2356 Scan_Ptr := Wptr;
2357 goto Scan_Line_Terminator;
2358
2359 -- Punctuation is an error (at start of identifier)
2360
2361 elsif Is_UTF_32_Punctuation (Cat) then
2362 Error_Msg ("identifier cannot start with punctuation", Wptr);
2363 Scan_Ptr := Wptr;
2364 Name_Len := 0;
2365 Underline_Found := False;
2366 goto Scan_Identifier;
2367
2368 -- Mark character is an error (at start of identifier)
2369
2370 elsif Is_UTF_32_Mark (Cat) then
2371 Error_Msg ("identifier cannot start with mark character", Wptr);
2372 Scan_Ptr := Wptr;
2373 Name_Len := 0;
2374 Underline_Found := False;
2375 goto Scan_Identifier;
2376
2377 -- Extended digit character is an error. Could be bad start of
2378 -- identifier or bad literal. Not worth doing too much to try to
2379 -- distinguish these cases, but we will do a little bit.
2380
2381 elsif Is_UTF_32_Digit (Cat) then
2382 Error_Msg
2383 ("identifier cannot start with digit character", Wptr);
2384 Scan_Ptr := Wptr;
2385 Name_Len := 0;
2386 Underline_Found := False;
2387 goto Scan_Identifier;
2388
2389 -- All other wide characters are illegal here
2390
2391 else
2392 Error_Illegal_Wide_Character;
2393 goto Scan_Next_Character;
2394 end if;
2395 end;
2396
2397 -- Routine to scan line terminator. On entry Scan_Ptr points to a
2398 -- character which is one of FF,LR,CR,VT, or one of the wide characters
2399 -- that is treated as a line terminator.
2400
2401 <<Scan_Line_Terminator>>
2402
2403 -- Check line too long
2404
2405 Check_End_Of_Line;
2406
2407 -- Set Token_Ptr, if End_Of_Line is a token, for the case when it is
2408 -- a physical line.
2409
2410 if End_Of_Line_Is_Token then
2411 Token_Ptr := Scan_Ptr;
2412 end if;
2413
2414 declare
2415 Physical : Boolean;
2416
2417 begin
2418 Skip_Line_Terminators (Scan_Ptr, Physical);
2419
2420 -- If we are at start of physical line, update scan pointers to
2421 -- reflect the start of the new line.
2422
2423 if Physical then
2424 Current_Line_Start := Scan_Ptr;
2425 Start_Column := Set_Start_Column;
2426 First_Non_Blank_Location := Scan_Ptr;
2427
2428 -- If End_Of_Line is a token, we return it as it is a
2429 -- physical line.
2430
2431 if End_Of_Line_Is_Token then
2432 Token := Tok_End_Of_Line;
2433 return;
2434 end if;
2435 end if;
2436 end;
2437
2438 goto Scan_Next_Character;
2439
2440 -- Identifier scanning routine. On entry, some initial characters of
2441 -- the identifier may have already been stored in Name_Buffer. If so,
2442 -- Name_Len has the number of characters stored, otherwise Name_Len is
2443 -- set to zero on entry. Underline_Found is also set False on entry.
2444
2445 <<Scan_Identifier>>
2446
2447 -- This loop scans as fast as possible past lower half letters and
2448 -- digits, which we expect to be the most common characters.
2449
2450 loop
2451 if Source (Scan_Ptr) in 'a' .. 'z'
2452 or else Source (Scan_Ptr) in '0' .. '9'
2453 then
2454 Name_Buffer (Name_Len + 1) := Source (Scan_Ptr);
2455 Accumulate_Checksum (Source (Scan_Ptr));
2456
2457 elsif Source (Scan_Ptr) in 'A' .. 'Z' then
2458 Name_Buffer (Name_Len + 1) :=
2459 Character'Val (Character'Pos (Source (Scan_Ptr)) + 32);
2460 Accumulate_Checksum (Name_Buffer (Name_Len + 1));
2461
2462 else
2463 exit;
2464 end if;
2465
2466 Underline_Found := False;
2467 Scan_Ptr := Scan_Ptr + 1;
2468 Name_Len := Name_Len + 1;
2469 end loop;
2470
2471 -- If we fall through, then we have encountered either an underline
2472 -- character, or an extended identifier character (i.e. one from the
2473 -- upper half), or a wide character, or an identifier terminator. The
2474 -- initial test speeds us up in the most common case where we have
2475 -- an identifier terminator. Note that ESC is an identifier character
2476 -- only if a wide character encoding method that uses ESC encoding
2477 -- is active, so if we find an ESC character we know that we have a
2478 -- wide character.
2479
2480 if Identifier_Char (Source (Scan_Ptr))
2481 or else (Source (Scan_Ptr) in Upper_Half_Character
2482 and then Upper_Half_Encoding)
2483 then
2484 -- Case of underline
2485
2486 if Source (Scan_Ptr) = '_' then
2487 Accumulate_Checksum ('_');
2488
2489 if Underline_Found then
2490 Error_No_Double_Underline;
2491 else
2492 Underline_Found := True;
2493 Name_Len := Name_Len + 1;
2494 Name_Buffer (Name_Len) := '_';
2495 end if;
2496
2497 Scan_Ptr := Scan_Ptr + 1;
2498 goto Scan_Identifier;
2499
2500 -- Upper half character
2501
2502 elsif Source (Scan_Ptr) in Upper_Half_Character
2503 and then not Upper_Half_Encoding
2504 then
2505 Accumulate_Checksum (Source (Scan_Ptr));
2506 Store_Encoded_Character
2507 (Get_Char_Code (Fold_Lower (Source (Scan_Ptr))));
2508 Scan_Ptr := Scan_Ptr + 1;
2509 Underline_Found := False;
2510 goto Scan_Identifier;
2511
2512 -- Left bracket not followed by a quote terminates an identifier.
2513 -- This is an error, but we don't want to give a junk error msg
2514 -- about wide characters in this case.
2515
2516 elsif Source (Scan_Ptr) = '['
2517 and then Source (Scan_Ptr + 1) /= '"'
2518 then
2519 null;
2520
2521 -- We know we have a wide character encoding here (the current
2522 -- character is either ESC, left bracket, or an upper half
2523 -- character depending on the encoding method).
2524
2525 else
2526 -- Scan out the wide character and insert the appropriate
2527 -- encoding into the name table entry for the identifier.
2528
2529 declare
2530 Code : Char_Code;
2531 Err : Boolean;
2532 Chr : Character;
2533 Cat : Category;
2534
2535 begin
2536 Wptr := Scan_Ptr;
2537 Scan_Wide (Source, Scan_Ptr, Code, Err);
2538
2539 -- If error, signal error
2540
2541 if Err then
2542 Error_Illegal_Wide_Character;
2543
2544 -- If the character scanned is a normal identifier
2545 -- character, then we treat it that way.
2546
2547 elsif In_Character_Range (Code)
2548 and then Identifier_Char (Get_Character (Code))
2549 then
2550 Chr := Get_Character (Code);
2551 Accumulate_Checksum (Chr);
2552 Store_Encoded_Character
2553 (Get_Char_Code (Fold_Lower (Chr)));
2554 Underline_Found := False;
2555
2556 -- Here if not a normal identifier character
2557
2558 else
2559 Cat := Get_Category (UTF_32 (Code));
2560
2561 -- Wide character in Unicode category "Other, Format"
2562 -- is not accepted in an identifier. This is because it
2563 -- it is considered a security risk (AI-0091).
2564
2565 -- However, it is OK for such a character to appear at
2566 -- the end of an identifier.
2567
2568 if Is_UTF_32_Other (Cat) then
2569 if not Identifier_Char (Source (Scan_Ptr)) then
2570 goto Scan_Identifier_Complete;
2571 else
2572 Error_Msg
2573 ("identifier cannot contain other_format "
2574 & "character", Wptr);
2575 goto Scan_Identifier;
2576 end if;
2577
2578 -- Wide character in category Separator,Space terminates
2579
2580 elsif Is_UTF_32_Space (Cat) then
2581 goto Scan_Identifier_Complete;
2582 end if;
2583
2584 -- Here if wide character is part of the identifier
2585
2586 -- Make sure we are allowing wide characters in
2587 -- identifiers. Note that we allow wide character
2588 -- notation for an OK identifier character. This in
2589 -- particular allows bracket or other notation to be
2590 -- used for upper half letters.
2591
2592 -- Wide characters are always allowed in Ada 2005
2593
2594 if Identifier_Character_Set /= 'w'
2595 and then Ada_Version < Ada_2005
2596 then
2597 Error_Msg
2598 ("wide character not allowed in identifier", Wptr);
2599 end if;
2600
2601 -- If OK letter, store it folding to upper case. Note
2602 -- that we include the folded letter in the checksum.
2603
2604 if Is_UTF_32_Letter (Cat) then
2605 Code :=
2606 Char_Code (UTF_32_To_Upper_Case (UTF_32 (Code)));
2607 Accumulate_Checksum (Code);
2608 Store_Encoded_Character (Code);
2609 Underline_Found := False;
2610
2611 -- If OK extended digit or mark, then store it
2612
2613 elsif Is_UTF_32_Digit (Cat)
2614 or else Is_UTF_32_Mark (Cat)
2615 then
2616 Accumulate_Checksum (Code);
2617 Store_Encoded_Character (Code);
2618 Underline_Found := False;
2619
2620 -- Wide punctuation is also stored, but counts as an
2621 -- underline character for error checking purposes.
2622
2623 elsif Is_UTF_32_Punctuation (Cat) then
2624 Accumulate_Checksum (Code);
2625
2626 if Underline_Found then
2627 declare
2628 Cend : constant Source_Ptr := Scan_Ptr;
2629 begin
2630 Scan_Ptr := Wptr;
2631 Error_No_Double_Underline;
2632 Scan_Ptr := Cend;
2633 end;
2634
2635 else
2636 Store_Encoded_Character (Code);
2637 Underline_Found := True;
2638 end if;
2639
2640 -- Any other wide character is not acceptable
2641
2642 else
2643 Error_Msg
2644 ("invalid wide character in identifier", Wptr);
2645 end if;
2646 end if;
2647
2648 goto Scan_Identifier;
2649 end;
2650 end if;
2651 end if;
2652
2653 -- Scan of identifier is complete. The identifier is stored in
2654 -- Name_Buffer, and Scan_Ptr points past the last character.
2655
2656 <<Scan_Identifier_Complete>>
2657 Token_Name := Name_Find;
2658
2659 -- Check for identifier ending with underline or punctuation char
2660
2661 if Underline_Found then
2662 Underline_Found := False;
2663
2664 if Source (Scan_Ptr - 1) = '_' then
2665 Error_Msg
2666 ("identifier cannot end with underline", Scan_Ptr - 1);
2667 else
2668 Error_Msg
2669 ("identifier cannot end with punctuation character", Wptr);
2670 end if;
2671 end if;
2672
2673 -- We will assume it is an identifier, not a keyword, so that the
2674 -- checksum is independent of the Ada version.
2675
2676 Token := Tok_Identifier;
2677
2678 -- Here is where we check if it was a keyword
2679
2680 if Is_Keyword_Name (Token_Name) then
2681 if Opt.Checksum_GNAT_6_3 then
2682 Token := Token_Type'Val (Get_Name_Table_Byte (Token_Name));
2683
2684 if Checksum_Accumulate_Token_Checksum then
2685 if Checksum_GNAT_5_03 then
2686 Accumulate_Token_Checksum_GNAT_5_03;
2687 else
2688 Accumulate_Token_Checksum_GNAT_6_3;
2689 end if;
2690 end if;
2691
2692 else
2693 Accumulate_Token_Checksum;
2694 Token := Token_Type'Val (Get_Name_Table_Byte (Token_Name));
2695 end if;
2696
2697 -- Keyword style checks
2698
2699 if Style_Check then
2700
2701 -- Deal with possible style check for non-lower case keyword,
2702 -- but we don't treat ACCESS, DELTA, DIGITS, RANGE as keywords
2703 -- for this purpose if they appear as attribute designators.
2704 -- Actually we only check the first character for speed.
2705
2706 -- Ada 2005 (AI-284): Do not apply the style check in case of
2707 -- "pragma Interface"
2708
2709 -- Ada 2005 (AI-340): Do not apply the style check in case of
2710 -- MOD attribute.
2711
2712 if Source (Token_Ptr) <= 'Z'
2713 and then (Prev_Token /= Tok_Apostrophe
2714 or else
2715 (Token /= Tok_Access and then
2716 Token /= Tok_Delta and then
2717 Token /= Tok_Digits and then
2718 Token /= Tok_Mod and then
2719 Token /= Tok_Range))
2720 and then (Token /= Tok_Interface
2721 or else
2722 (Token = Tok_Interface
2723 and then Prev_Token /= Tok_Pragma))
2724 then
2725 Style.Non_Lower_Case_Keyword;
2726 end if;
2727
2728 -- Check THEN/ELSE style rules. These do not apply to AND THEN
2729 -- or OR ELSE, and do not apply in if expressions.
2730
2731 if (Token = Tok_Then and then Prev_Token /= Tok_And)
2732 or else
2733 (Token = Tok_Else and then Prev_Token /= Tok_Or)
2734 then
2735 if Inside_If_Expression = 0 then
2736 Style.Check_Separate_Stmt_Lines;
2737 end if;
2738 end if;
2739 end if;
2740
2741 -- We must reset Token_Name since this is not an identifier and
2742 -- if we leave Token_Name set, the parser gets confused because
2743 -- it thinks it is dealing with an identifier instead of the
2744 -- corresponding keyword.
2745
2746 Token_Name := No_Name;
2747 return;
2748
2749 -- It is an identifier after all
2750
2751 else
2752 if Checksum_Accumulate_Token_Checksum then
2753 Accumulate_Token_Checksum;
2754 end if;
2755
2756 Post_Scan;
2757 return;
2758 end if;
2759 end Scan;
2760
2761 --------------------------
2762 -- Set_Comment_As_Token --
2763 --------------------------
2764
2765 procedure Set_Comment_As_Token (Value : Boolean) is
2766 begin
2767 Comment_Is_Token := Value;
2768 end Set_Comment_As_Token;
2769
2770 ------------------------------
2771 -- Set_End_Of_Line_As_Token --
2772 ------------------------------
2773
2774 procedure Set_End_Of_Line_As_Token (Value : Boolean) is
2775 begin
2776 End_Of_Line_Is_Token := Value;
2777 end Set_End_Of_Line_As_Token;
2778
2779 ---------------------------
2780 -- Set_Special_Character --
2781 ---------------------------
2782
2783 procedure Set_Special_Character (C : Character) is
2784 begin
2785 case C is
2786 when '#' | '$' | '_' | '?' | '@' | '`' | '\' | '^' | '~' =>
2787 Special_Characters (C) := True;
2788
2789 when others =>
2790 null;
2791 end case;
2792 end Set_Special_Character;
2793
2794 ----------------------
2795 -- Set_Start_Column --
2796 ----------------------
2797
2798 -- Note: it seems at first glance a little expensive to compute this value
2799 -- for every source line (since it is certainly not used for all source
2800 -- lines). On the other hand, it doesn't take much more work to skip past
2801 -- the initial white space on the line counting the columns than it would
2802 -- to scan past the white space using the standard scanning circuits.
2803
2804 function Set_Start_Column return Column_Number is
2805 Start_Column : Column_Number := 0;
2806
2807 begin
2808 -- Outer loop scans past horizontal tab characters
2809
2810 Tabs_Loop : loop
2811
2812 -- Inner loop scans past blanks as fast as possible, bumping Scan_Ptr
2813 -- past the blanks and adjusting Start_Column to account for them.
2814
2815 Blanks_Loop : loop
2816 if Source (Scan_Ptr) = ' ' then
2817 if Source (Scan_Ptr + 1) = ' ' then
2818 if Source (Scan_Ptr + 2) = ' ' then
2819 if Source (Scan_Ptr + 3) = ' ' then
2820 if Source (Scan_Ptr + 4) = ' ' then
2821 if Source (Scan_Ptr + 5) = ' ' then
2822 if Source (Scan_Ptr + 6) = ' ' then
2823 Scan_Ptr := Scan_Ptr + 7;
2824 Start_Column := Start_Column + 7;
2825 else
2826 Scan_Ptr := Scan_Ptr + 6;
2827 Start_Column := Start_Column + 6;
2828 exit Blanks_Loop;
2829 end if;
2830 else
2831 Scan_Ptr := Scan_Ptr + 5;
2832 Start_Column := Start_Column + 5;
2833 exit Blanks_Loop;
2834 end if;
2835 else
2836 Scan_Ptr := Scan_Ptr + 4;
2837 Start_Column := Start_Column + 4;
2838 exit Blanks_Loop;
2839 end if;
2840 else
2841 Scan_Ptr := Scan_Ptr + 3;
2842 Start_Column := Start_Column + 3;
2843 exit Blanks_Loop;
2844 end if;
2845 else
2846 Scan_Ptr := Scan_Ptr + 2;
2847 Start_Column := Start_Column + 2;
2848 exit Blanks_Loop;
2849 end if;
2850 else
2851 Scan_Ptr := Scan_Ptr + 1;
2852 Start_Column := Start_Column + 1;
2853 exit Blanks_Loop;
2854 end if;
2855 else
2856 exit Blanks_Loop;
2857 end if;
2858 end loop Blanks_Loop;
2859
2860 -- Outer loop keeps going only if a horizontal tab follows
2861
2862 if Source (Scan_Ptr) = HT then
2863 if Style_Check then
2864 Style.Check_HT;
2865 end if;
2866
2867 Scan_Ptr := Scan_Ptr + 1;
2868 Start_Column := (Start_Column / 8) * 8 + 8;
2869 else
2870 exit Tabs_Loop;
2871 end if;
2872 end loop Tabs_Loop;
2873
2874 return Start_Column;
2875
2876 -- A constraint error can happen only if we have a compiler with checks on
2877 -- and a line with a ludicrous number of tabs or spaces at the start. In
2878 -- such a case, we really don't care if Start_Column is right or not.
2879
2880 exception
2881 when Constraint_Error =>
2882 return Start_Column;
2883 end Set_Start_Column;
2884
2885 end Scng;
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