]>
Commit | Line | Data |
---|---|---|
fbf5a39b AC |
1 | ------------------------------------------------------------------------------ |
2 | -- -- | |
3 | -- GNAT COMPILER COMPONENTS -- | |
4 | -- -- | |
5 | -- S C N G -- | |
6 | -- -- | |
7 | -- B o d y -- | |
8 | -- -- | |
555360a5 | 9 | -- Copyright (C) 1992-2004 Free Software Foundation, Inc. -- |
fbf5a39b AC |
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 2, 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 COPYING. If not, write -- | |
19 | -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- | |
20 | -- MA 02111-1307, USA. -- | |
21 | -- -- | |
22 | -- GNAT was originally developed by the GNAT team at New York University. -- | |
23 | -- Extensive contributions were provided by Ada Core Technologies Inc. -- | |
24 | -- -- | |
25 | ------------------------------------------------------------------------------ | |
26 | ||
27 | with Csets; use Csets; | |
28 | with Err_Vars; use Err_Vars; | |
fbf5a39b AC |
29 | with Namet; use Namet; |
30 | with Opt; use Opt; | |
31 | with Scans; use Scans; | |
32 | with Sinput; use Sinput; | |
33 | with Snames; use Snames; | |
34 | with Stringt; use Stringt; | |
35 | with Stylesw; use Stylesw; | |
36 | with Uintp; use Uintp; | |
37 | with Urealp; use Urealp; | |
38 | with Widechar; use Widechar; | |
39 | ||
40 | with System.CRC32; | |
41 | with System.WCh_Con; use System.WCh_Con; | |
42 | ||
43 | package body Scng is | |
44 | ||
45 | use ASCII; | |
46 | -- Make control characters visible | |
47 | ||
48 | Special_Characters : array (Character) of Boolean := (others => False); | |
49 | -- For characters that are Special token, the value is True | |
50 | ||
c45b6ae0 AC |
51 | Comment_Is_Token : Boolean := False; |
52 | -- True if comments are tokens | |
53 | ||
fbf5a39b AC |
54 | End_Of_Line_Is_Token : Boolean := False; |
55 | -- True if End_Of_Line is a token | |
56 | ||
57 | ----------------------- | |
58 | -- Local Subprograms -- | |
59 | ----------------------- | |
60 | ||
6b6fcd3e AC |
61 | procedure Accumulate_Token_Checksum; |
62 | pragma Inline (Accumulate_Token_Checksum); | |
63 | ||
fbf5a39b AC |
64 | procedure Accumulate_Checksum (C : Character); |
65 | pragma Inline (Accumulate_Checksum); | |
66 | -- This routine accumulates the checksum given character C. During the | |
67 | -- scanning of a source file, this routine is called with every character | |
68 | -- in the source, excluding blanks, and all control characters (except | |
69 | -- that ESC is included in the checksum). Upper case letters not in string | |
70 | -- literals are folded by the caller. See Sinput spec for the documentation | |
71 | -- of the checksum algorithm. Note: checksum values are only used if we | |
72 | -- generate code, so it is not necessary to worry about making the right | |
73 | -- sequence of calls in any error situation. | |
74 | ||
75 | procedure Accumulate_Checksum (C : Char_Code); | |
76 | pragma Inline (Accumulate_Checksum); | |
77 | -- This version is identical, except that the argument, C, is a character | |
78 | -- code value instead of a character. This is used when wide characters | |
79 | -- are scanned. We use the character code rather than the ASCII characters | |
80 | -- so that the checksum is independent of wide character encoding method. | |
81 | ||
82 | procedure Initialize_Checksum; | |
83 | pragma Inline (Initialize_Checksum); | |
84 | -- Initialize checksum value | |
85 | ||
86 | ------------------------- | |
87 | -- Accumulate_Checksum -- | |
88 | ------------------------- | |
89 | ||
90 | procedure Accumulate_Checksum (C : Character) is | |
91 | begin | |
92 | System.CRC32.Update (System.CRC32.CRC32 (Checksum), C); | |
93 | end Accumulate_Checksum; | |
94 | ||
95 | procedure Accumulate_Checksum (C : Char_Code) is | |
96 | begin | |
97 | Accumulate_Checksum (Character'Val (C / 256)); | |
98 | Accumulate_Checksum (Character'Val (C mod 256)); | |
99 | end Accumulate_Checksum; | |
100 | ||
6b6fcd3e AC |
101 | ------------------------------- |
102 | -- Accumulate_Token_Checksum -- | |
103 | ------------------------------- | |
104 | ||
105 | procedure Accumulate_Token_Checksum is | |
106 | begin | |
107 | System.CRC32.Update | |
108 | (System.CRC32.CRC32 (Checksum), | |
109 | Character'Val (Token_Type'Pos (Token))); | |
110 | end Accumulate_Token_Checksum; | |
111 | ||
fbf5a39b AC |
112 | ---------------------------- |
113 | -- Determine_Token_Casing -- | |
114 | ---------------------------- | |
115 | ||
116 | function Determine_Token_Casing return Casing_Type is | |
117 | begin | |
118 | return Determine_Casing (Source (Token_Ptr .. Scan_Ptr - 1)); | |
119 | end Determine_Token_Casing; | |
120 | ||
121 | ------------------------- | |
122 | -- Initialize_Checksum -- | |
123 | ------------------------- | |
124 | ||
125 | procedure Initialize_Checksum is | |
126 | begin | |
127 | System.CRC32.Initialize (System.CRC32.CRC32 (Checksum)); | |
128 | end Initialize_Checksum; | |
129 | ||
130 | ------------------------ | |
131 | -- Initialize_Scanner -- | |
132 | ------------------------ | |
133 | ||
134 | procedure Initialize_Scanner | |
135 | (Unit : Unit_Number_Type; | |
136 | Index : Source_File_Index) | |
137 | is | |
138 | begin | |
139 | -- Set up Token_Type values in Names Table entries for reserved keywords | |
140 | -- We use the Pos value of the Token_Type value. Note we are relying on | |
141 | -- the fact that Token_Type'Val (0) is not a reserved word! | |
142 | ||
143 | Set_Name_Table_Byte (Name_Abort, Token_Type'Pos (Tok_Abort)); | |
144 | Set_Name_Table_Byte (Name_Abs, Token_Type'Pos (Tok_Abs)); | |
145 | Set_Name_Table_Byte (Name_Abstract, Token_Type'Pos (Tok_Abstract)); | |
146 | Set_Name_Table_Byte (Name_Accept, Token_Type'Pos (Tok_Accept)); | |
147 | Set_Name_Table_Byte (Name_Access, Token_Type'Pos (Tok_Access)); | |
148 | Set_Name_Table_Byte (Name_And, Token_Type'Pos (Tok_And)); | |
149 | Set_Name_Table_Byte (Name_Aliased, Token_Type'Pos (Tok_Aliased)); | |
150 | Set_Name_Table_Byte (Name_All, Token_Type'Pos (Tok_All)); | |
151 | Set_Name_Table_Byte (Name_Array, Token_Type'Pos (Tok_Array)); | |
152 | Set_Name_Table_Byte (Name_At, Token_Type'Pos (Tok_At)); | |
153 | Set_Name_Table_Byte (Name_Begin, Token_Type'Pos (Tok_Begin)); | |
154 | Set_Name_Table_Byte (Name_Body, Token_Type'Pos (Tok_Body)); | |
155 | Set_Name_Table_Byte (Name_Case, Token_Type'Pos (Tok_Case)); | |
156 | Set_Name_Table_Byte (Name_Constant, Token_Type'Pos (Tok_Constant)); | |
157 | Set_Name_Table_Byte (Name_Declare, Token_Type'Pos (Tok_Declare)); | |
158 | Set_Name_Table_Byte (Name_Delay, Token_Type'Pos (Tok_Delay)); | |
159 | Set_Name_Table_Byte (Name_Delta, Token_Type'Pos (Tok_Delta)); | |
160 | Set_Name_Table_Byte (Name_Digits, Token_Type'Pos (Tok_Digits)); | |
161 | Set_Name_Table_Byte (Name_Do, Token_Type'Pos (Tok_Do)); | |
162 | Set_Name_Table_Byte (Name_Else, Token_Type'Pos (Tok_Else)); | |
163 | Set_Name_Table_Byte (Name_Elsif, Token_Type'Pos (Tok_Elsif)); | |
164 | Set_Name_Table_Byte (Name_End, Token_Type'Pos (Tok_End)); | |
165 | Set_Name_Table_Byte (Name_Entry, Token_Type'Pos (Tok_Entry)); | |
166 | Set_Name_Table_Byte (Name_Exception, Token_Type'Pos (Tok_Exception)); | |
167 | Set_Name_Table_Byte (Name_Exit, Token_Type'Pos (Tok_Exit)); | |
168 | Set_Name_Table_Byte (Name_For, Token_Type'Pos (Tok_For)); | |
169 | Set_Name_Table_Byte (Name_Function, Token_Type'Pos (Tok_Function)); | |
170 | Set_Name_Table_Byte (Name_Generic, Token_Type'Pos (Tok_Generic)); | |
171 | Set_Name_Table_Byte (Name_Goto, Token_Type'Pos (Tok_Goto)); | |
172 | Set_Name_Table_Byte (Name_If, Token_Type'Pos (Tok_If)); | |
173 | Set_Name_Table_Byte (Name_In, Token_Type'Pos (Tok_In)); | |
174 | Set_Name_Table_Byte (Name_Is, Token_Type'Pos (Tok_Is)); | |
175 | Set_Name_Table_Byte (Name_Limited, Token_Type'Pos (Tok_Limited)); | |
176 | Set_Name_Table_Byte (Name_Loop, Token_Type'Pos (Tok_Loop)); | |
177 | Set_Name_Table_Byte (Name_Mod, Token_Type'Pos (Tok_Mod)); | |
178 | Set_Name_Table_Byte (Name_New, Token_Type'Pos (Tok_New)); | |
179 | Set_Name_Table_Byte (Name_Not, Token_Type'Pos (Tok_Not)); | |
180 | Set_Name_Table_Byte (Name_Null, Token_Type'Pos (Tok_Null)); | |
181 | Set_Name_Table_Byte (Name_Of, Token_Type'Pos (Tok_Of)); | |
182 | Set_Name_Table_Byte (Name_Or, Token_Type'Pos (Tok_Or)); | |
183 | Set_Name_Table_Byte (Name_Others, Token_Type'Pos (Tok_Others)); | |
184 | Set_Name_Table_Byte (Name_Out, Token_Type'Pos (Tok_Out)); | |
185 | Set_Name_Table_Byte (Name_Package, Token_Type'Pos (Tok_Package)); | |
186 | Set_Name_Table_Byte (Name_Pragma, Token_Type'Pos (Tok_Pragma)); | |
187 | Set_Name_Table_Byte (Name_Private, Token_Type'Pos (Tok_Private)); | |
188 | Set_Name_Table_Byte (Name_Procedure, Token_Type'Pos (Tok_Procedure)); | |
189 | Set_Name_Table_Byte (Name_Protected, Token_Type'Pos (Tok_Protected)); | |
190 | Set_Name_Table_Byte (Name_Raise, Token_Type'Pos (Tok_Raise)); | |
191 | Set_Name_Table_Byte (Name_Range, Token_Type'Pos (Tok_Range)); | |
192 | Set_Name_Table_Byte (Name_Record, Token_Type'Pos (Tok_Record)); | |
193 | Set_Name_Table_Byte (Name_Rem, Token_Type'Pos (Tok_Rem)); | |
194 | Set_Name_Table_Byte (Name_Renames, Token_Type'Pos (Tok_Renames)); | |
195 | Set_Name_Table_Byte (Name_Requeue, Token_Type'Pos (Tok_Requeue)); | |
196 | Set_Name_Table_Byte (Name_Return, Token_Type'Pos (Tok_Return)); | |
197 | Set_Name_Table_Byte (Name_Reverse, Token_Type'Pos (Tok_Reverse)); | |
198 | Set_Name_Table_Byte (Name_Select, Token_Type'Pos (Tok_Select)); | |
199 | Set_Name_Table_Byte (Name_Separate, Token_Type'Pos (Tok_Separate)); | |
200 | Set_Name_Table_Byte (Name_Subtype, Token_Type'Pos (Tok_Subtype)); | |
201 | Set_Name_Table_Byte (Name_Tagged, Token_Type'Pos (Tok_Tagged)); | |
202 | Set_Name_Table_Byte (Name_Task, Token_Type'Pos (Tok_Task)); | |
203 | Set_Name_Table_Byte (Name_Terminate, Token_Type'Pos (Tok_Terminate)); | |
204 | Set_Name_Table_Byte (Name_Then, Token_Type'Pos (Tok_Then)); | |
205 | Set_Name_Table_Byte (Name_Type, Token_Type'Pos (Tok_Type)); | |
206 | Set_Name_Table_Byte (Name_Until, Token_Type'Pos (Tok_Until)); | |
207 | Set_Name_Table_Byte (Name_Use, Token_Type'Pos (Tok_Use)); | |
208 | Set_Name_Table_Byte (Name_When, Token_Type'Pos (Tok_When)); | |
209 | Set_Name_Table_Byte (Name_While, Token_Type'Pos (Tok_While)); | |
210 | Set_Name_Table_Byte (Name_With, Token_Type'Pos (Tok_With)); | |
211 | Set_Name_Table_Byte (Name_Xor, Token_Type'Pos (Tok_Xor)); | |
212 | ||
213 | -- Initialize scan control variables | |
214 | ||
215 | Current_Source_File := Index; | |
216 | Source := Source_Text (Current_Source_File); | |
217 | Current_Source_Unit := Unit; | |
218 | Scan_Ptr := Source_First (Current_Source_File); | |
219 | Token := No_Token; | |
220 | Token_Ptr := Scan_Ptr; | |
221 | Current_Line_Start := Scan_Ptr; | |
222 | Token_Node := Empty; | |
223 | Token_Name := No_Name; | |
224 | Start_Column := Set_Start_Column; | |
225 | First_Non_Blank_Location := Scan_Ptr; | |
226 | ||
227 | Initialize_Checksum; | |
228 | ||
229 | -- Do not call Scan, otherwise the License stuff does not work in Scn. | |
230 | ||
231 | end Initialize_Scanner; | |
232 | ||
233 | ------------------------------ | |
234 | -- Reset_Special_Characters -- | |
235 | ------------------------------ | |
236 | ||
237 | procedure Reset_Special_Characters is | |
238 | begin | |
239 | Special_Characters := (others => False); | |
240 | end Reset_Special_Characters; | |
241 | ||
242 | ---------- | |
243 | -- Scan -- | |
244 | ---------- | |
245 | ||
246 | procedure Scan is | |
247 | ||
c45b6ae0 AC |
248 | Start_Of_Comment : Source_Ptr; |
249 | ||
fbf5a39b AC |
250 | procedure Check_End_Of_Line; |
251 | -- Called when end of line encountered. Checks that line is not | |
252 | -- too long, and that other style checks for the end of line are met. | |
253 | ||
254 | function Double_Char_Token (C : Character) return Boolean; | |
255 | -- This function is used for double character tokens like := or <>. It | |
256 | -- checks if the character following Source (Scan_Ptr) is C, and if so | |
257 | -- bumps Scan_Ptr past the pair of characters and returns True. A space | |
258 | -- between the two characters is also recognized with an appropriate | |
259 | -- error message being issued. If C is not present, False is returned. | |
260 | -- Note that Double_Char_Token can only be used for tokens defined in | |
261 | -- the Ada syntax (it's use for error cases like && is not appropriate | |
262 | -- since we do not want a junk message for a case like &-space-&). | |
263 | ||
264 | procedure Error_Illegal_Character; | |
265 | -- Give illegal character error, Scan_Ptr points to character. | |
266 | -- On return, Scan_Ptr is bumped past the illegal character. | |
267 | ||
268 | procedure Error_Illegal_Wide_Character; | |
269 | -- Give illegal wide character message. On return, Scan_Ptr is bumped | |
270 | -- past the illegal character, which may still leave us pointing to | |
271 | -- junk, not much we can do if the escape sequence is messed up! | |
272 | ||
273 | procedure Error_Long_Line; | |
274 | -- Signal error of excessively long line | |
275 | ||
276 | procedure Error_No_Double_Underline; | |
277 | -- Signal error of double underline character | |
278 | ||
279 | procedure Nlit; | |
280 | -- This is the procedure for scanning out numeric literals. On entry, | |
281 | -- Scan_Ptr points to the digit that starts the numeric literal (the | |
282 | -- checksum for this character has not been accumulated yet). On return | |
283 | -- Scan_Ptr points past the last character of the numeric literal, Token | |
284 | -- and Token_Node are set appropriately, and the checksum is updated. | |
285 | ||
286 | procedure Slit; | |
287 | -- This is the procedure for scanning out string literals. On entry, | |
288 | -- Scan_Ptr points to the opening string quote (the checksum for this | |
289 | -- character has not been accumulated yet). On return Scan_Ptr points | |
290 | -- past the closing quote of the string literal, Token and Token_Node | |
291 | -- are set appropriately, and the checksum is upated. | |
292 | ||
293 | ----------------------- | |
294 | -- Check_End_Of_Line -- | |
295 | ----------------------- | |
296 | ||
297 | procedure Check_End_Of_Line is | |
298 | Len : constant Int := Int (Scan_Ptr) - Int (Current_Line_Start); | |
299 | ||
300 | begin | |
301 | if Style_Check and Style_Check_Max_Line_Length then | |
302 | Style.Check_Line_Terminator (Len); | |
303 | ||
5950a3ac AC |
304 | -- If style checking is inactive, check maximum line length against |
305 | -- standard value. Note that we take this from Opt.Max_Line_Length | |
306 | -- rather than Hostparm.Max_Line_Length because we do not want to | |
307 | -- impose any limit during scanning of configuration pragma files, | |
308 | -- and Opt.Max_Line_Length (normally set to Hostparm.Max_Line_Length) | |
309 | -- is reset to Column_Number'Max during scanning of such files. | |
310 | ||
311 | elsif Len > Opt.Max_Line_Length then | |
fbf5a39b AC |
312 | Error_Long_Line; |
313 | end if; | |
314 | end Check_End_Of_Line; | |
315 | ||
316 | ----------------------- | |
317 | -- Double_Char_Token -- | |
318 | ----------------------- | |
319 | ||
320 | function Double_Char_Token (C : Character) return Boolean is | |
321 | begin | |
322 | if Source (Scan_Ptr + 1) = C then | |
323 | Accumulate_Checksum (C); | |
324 | Scan_Ptr := Scan_Ptr + 2; | |
325 | return True; | |
326 | ||
327 | elsif Source (Scan_Ptr + 1) = ' ' | |
328 | and then Source (Scan_Ptr + 2) = C | |
329 | then | |
330 | Scan_Ptr := Scan_Ptr + 1; | |
331 | Error_Msg_S ("no space allowed here"); | |
332 | Scan_Ptr := Scan_Ptr + 2; | |
333 | return True; | |
334 | ||
335 | else | |
336 | return False; | |
337 | end if; | |
338 | end Double_Char_Token; | |
339 | ||
340 | ----------------------------- | |
341 | -- Error_Illegal_Character -- | |
342 | ----------------------------- | |
343 | ||
344 | procedure Error_Illegal_Character is | |
345 | begin | |
346 | Error_Msg_S ("illegal character"); | |
347 | Scan_Ptr := Scan_Ptr + 1; | |
348 | end Error_Illegal_Character; | |
349 | ||
350 | ---------------------------------- | |
351 | -- Error_Illegal_Wide_Character -- | |
352 | ---------------------------------- | |
353 | ||
354 | procedure Error_Illegal_Wide_Character is | |
355 | begin | |
555360a5 | 356 | Error_Msg_S ("illegal wide character, check -gnatW switch"); |
fbf5a39b AC |
357 | Scan_Ptr := Scan_Ptr + 1; |
358 | end Error_Illegal_Wide_Character; | |
359 | ||
360 | --------------------- | |
361 | -- Error_Long_Line -- | |
362 | --------------------- | |
363 | ||
364 | procedure Error_Long_Line is | |
365 | begin | |
366 | Error_Msg | |
367 | ("this line is too long", | |
5950a3ac | 368 | Current_Line_Start + Source_Ptr (Opt.Max_Line_Length)); |
fbf5a39b AC |
369 | end Error_Long_Line; |
370 | ||
371 | ------------------------------- | |
372 | -- Error_No_Double_Underline -- | |
373 | ------------------------------- | |
374 | ||
375 | procedure Error_No_Double_Underline is | |
376 | begin | |
377 | Error_Msg_S ("two consecutive underlines not permitted"); | |
378 | end Error_No_Double_Underline; | |
379 | ||
380 | ---------- | |
381 | -- Nlit -- | |
382 | ---------- | |
383 | ||
384 | procedure Nlit is | |
385 | ||
386 | C : Character; | |
387 | -- Current source program character | |
388 | ||
389 | Base_Char : Character; | |
390 | -- Either # or : (character at start of based number) | |
391 | ||
392 | Base : Int; | |
393 | -- Value of base | |
394 | ||
395 | UI_Base : Uint; | |
396 | -- Value of base in Uint format | |
397 | ||
398 | UI_Int_Value : Uint; | |
399 | -- Value of integer scanned by Scan_Integer in Uint format | |
400 | ||
401 | UI_Num_Value : Uint; | |
402 | -- Value of integer in numeric value being scanned | |
403 | ||
404 | Scale : Int; | |
405 | -- Scale value for real literal | |
406 | ||
407 | UI_Scale : Uint; | |
408 | -- Scale in Uint format | |
409 | ||
410 | Exponent_Is_Negative : Boolean; | |
411 | -- Set true for negative exponent | |
412 | ||
413 | Extended_Digit_Value : Int; | |
414 | -- Extended digit value | |
415 | ||
416 | Point_Scanned : Boolean; | |
417 | -- Flag for decimal point scanned in numeric literal | |
418 | ||
419 | ----------------------- | |
420 | -- Local Subprograms -- | |
421 | ----------------------- | |
422 | ||
423 | procedure Error_Digit_Expected; | |
424 | -- Signal error of bad digit, Scan_Ptr points to the location at | |
425 | -- which the digit was expected on input, and is unchanged on return. | |
426 | ||
427 | procedure Scan_Integer; | |
428 | -- Procedure to scan integer literal. On entry, Scan_Ptr points to | |
429 | -- a digit, on exit Scan_Ptr points past the last character of | |
430 | -- the integer. | |
6b6fcd3e | 431 | -- |
fbf5a39b AC |
432 | -- For each digit encountered, UI_Int_Value is multiplied by 10, |
433 | -- and the value of the digit added to the result. In addition, | |
434 | -- the value in Scale is decremented by one for each actual digit | |
435 | -- scanned. | |
436 | ||
437 | -------------------------- | |
438 | -- Error_Digit_Expected -- | |
439 | -------------------------- | |
440 | ||
441 | procedure Error_Digit_Expected is | |
442 | begin | |
443 | Error_Msg_S ("digit expected"); | |
444 | end Error_Digit_Expected; | |
445 | ||
15ce9ca2 AC |
446 | ------------------ |
447 | -- Scan_Integer -- | |
448 | ------------------ | |
fbf5a39b AC |
449 | |
450 | procedure Scan_Integer is | |
451 | C : Character; | |
452 | -- Next character scanned | |
453 | ||
454 | begin | |
455 | C := Source (Scan_Ptr); | |
456 | ||
457 | -- Loop through digits (allowing underlines) | |
458 | ||
459 | loop | |
460 | Accumulate_Checksum (C); | |
461 | UI_Int_Value := | |
462 | UI_Int_Value * 10 + (Character'Pos (C) - Character'Pos ('0')); | |
463 | Scan_Ptr := Scan_Ptr + 1; | |
464 | Scale := Scale - 1; | |
465 | C := Source (Scan_Ptr); | |
466 | ||
467 | if C = '_' then | |
30c20106 AC |
468 | |
469 | -- We do not accumulate the '_' in the checksum, so that | |
470 | -- 1_234 is equivalent to 1234, and does not trigger | |
471 | -- compilation for "minimal recompilation" (gnatmake -m). | |
fbf5a39b AC |
472 | |
473 | loop | |
474 | Scan_Ptr := Scan_Ptr + 1; | |
475 | C := Source (Scan_Ptr); | |
476 | exit when C /= '_'; | |
477 | Error_No_Double_Underline; | |
478 | end loop; | |
479 | ||
480 | if C not in '0' .. '9' then | |
481 | Error_Digit_Expected; | |
482 | exit; | |
483 | end if; | |
484 | ||
485 | else | |
486 | exit when C not in '0' .. '9'; | |
487 | end if; | |
488 | end loop; | |
489 | ||
490 | end Scan_Integer; | |
491 | ||
492 | ---------------------------------- | |
493 | -- Start of Processing for Nlit -- | |
494 | ---------------------------------- | |
495 | ||
496 | begin | |
497 | Base := 10; | |
498 | UI_Base := Uint_10; | |
499 | UI_Int_Value := Uint_0; | |
500 | Scale := 0; | |
501 | Scan_Integer; | |
502 | Scale := 0; | |
503 | Point_Scanned := False; | |
504 | UI_Num_Value := UI_Int_Value; | |
505 | ||
506 | -- Various possibilities now for continuing the literal are | |
507 | -- period, E/e (for exponent), or :/# (for based literal). | |
508 | ||
509 | Scale := 0; | |
510 | C := Source (Scan_Ptr); | |
511 | ||
512 | if C = '.' then | |
513 | ||
514 | -- Scan out point, but do not scan past .. which is a range | |
515 | -- sequence, and must not be eaten up scanning a numeric literal. | |
516 | ||
517 | while C = '.' and then Source (Scan_Ptr + 1) /= '.' loop | |
518 | Accumulate_Checksum ('.'); | |
519 | ||
520 | if Point_Scanned then | |
521 | Error_Msg_S ("duplicate point ignored"); | |
522 | end if; | |
523 | ||
524 | Point_Scanned := True; | |
525 | Scan_Ptr := Scan_Ptr + 1; | |
526 | C := Source (Scan_Ptr); | |
527 | ||
528 | if C not in '0' .. '9' then | |
529 | Error_Msg | |
530 | ("real literal cannot end with point", Scan_Ptr - 1); | |
531 | else | |
532 | Scan_Integer; | |
533 | UI_Num_Value := UI_Int_Value; | |
534 | end if; | |
535 | end loop; | |
536 | ||
537 | -- Based literal case. The base is the value we already scanned. | |
538 | -- In the case of colon, we insist that the following character | |
539 | -- is indeed an extended digit or a period. This catches a number | |
540 | -- of common errors, as well as catching the well known tricky | |
541 | -- bug otherwise arising from "x : integer range 1 .. 10:= 6;" | |
542 | ||
543 | elsif C = '#' | |
544 | or else (C = ':' and then | |
545 | (Source (Scan_Ptr + 1) = '.' | |
546 | or else | |
547 | Source (Scan_Ptr + 1) in '0' .. '9' | |
548 | or else | |
549 | Source (Scan_Ptr + 1) in 'A' .. 'Z' | |
550 | or else | |
551 | Source (Scan_Ptr + 1) in 'a' .. 'z')) | |
552 | then | |
553 | if C = ':' and then Warn_On_Obsolescent_Feature then | |
554 | Error_Msg_S | |
555 | ("use of "":"" is an obsolescent feature ('R'M 'J.2(3))?"); | |
556 | Error_Msg_S | |
557 | ("\use ""'#"" instead?"); | |
558 | end if; | |
559 | ||
560 | Accumulate_Checksum (C); | |
561 | Base_Char := C; | |
562 | UI_Base := UI_Int_Value; | |
563 | ||
564 | if UI_Base < 2 or else UI_Base > 16 then | |
565 | Error_Msg_SC ("base not 2-16"); | |
566 | UI_Base := Uint_16; | |
567 | end if; | |
568 | ||
569 | Base := UI_To_Int (UI_Base); | |
570 | Scan_Ptr := Scan_Ptr + 1; | |
571 | ||
572 | -- Scan out extended integer [. integer] | |
573 | ||
574 | C := Source (Scan_Ptr); | |
575 | UI_Int_Value := Uint_0; | |
576 | Scale := 0; | |
577 | ||
578 | loop | |
579 | if C in '0' .. '9' then | |
580 | Accumulate_Checksum (C); | |
581 | Extended_Digit_Value := | |
582 | Int'(Character'Pos (C)) - Int'(Character'Pos ('0')); | |
583 | ||
584 | elsif C in 'A' .. 'F' then | |
585 | Accumulate_Checksum (Character'Val (Character'Pos (C) + 32)); | |
586 | Extended_Digit_Value := | |
587 | Int'(Character'Pos (C)) - Int'(Character'Pos ('A')) + 10; | |
588 | ||
589 | elsif C in 'a' .. 'f' then | |
590 | Accumulate_Checksum (C); | |
591 | Extended_Digit_Value := | |
592 | Int'(Character'Pos (C)) - Int'(Character'Pos ('a')) + 10; | |
593 | ||
594 | else | |
595 | Error_Msg_S ("extended digit expected"); | |
596 | exit; | |
597 | end if; | |
598 | ||
599 | if Extended_Digit_Value >= Base then | |
600 | Error_Msg_S ("digit '>= base"); | |
601 | end if; | |
602 | ||
603 | UI_Int_Value := UI_Int_Value * UI_Base + Extended_Digit_Value; | |
604 | Scale := Scale - 1; | |
605 | Scan_Ptr := Scan_Ptr + 1; | |
606 | C := Source (Scan_Ptr); | |
607 | ||
608 | if C = '_' then | |
609 | loop | |
610 | Accumulate_Checksum ('_'); | |
611 | Scan_Ptr := Scan_Ptr + 1; | |
612 | C := Source (Scan_Ptr); | |
613 | exit when C /= '_'; | |
614 | Error_No_Double_Underline; | |
615 | end loop; | |
616 | ||
617 | elsif C = '.' then | |
618 | Accumulate_Checksum ('.'); | |
619 | ||
620 | if Point_Scanned then | |
621 | Error_Msg_S ("duplicate point ignored"); | |
622 | end if; | |
623 | ||
624 | Scan_Ptr := Scan_Ptr + 1; | |
625 | C := Source (Scan_Ptr); | |
626 | Point_Scanned := True; | |
627 | Scale := 0; | |
628 | ||
629 | elsif C = Base_Char then | |
630 | Accumulate_Checksum (C); | |
631 | Scan_Ptr := Scan_Ptr + 1; | |
632 | exit; | |
633 | ||
634 | elsif C = '#' or else C = ':' then | |
635 | Error_Msg_S ("based number delimiters must match"); | |
636 | Scan_Ptr := Scan_Ptr + 1; | |
637 | exit; | |
638 | ||
639 | elsif not Identifier_Char (C) then | |
640 | if Base_Char = '#' then | |
641 | Error_Msg_S ("missing '#"); | |
642 | else | |
643 | Error_Msg_S ("missing ':"); | |
644 | end if; | |
645 | ||
646 | exit; | |
647 | end if; | |
648 | ||
649 | end loop; | |
650 | ||
651 | UI_Num_Value := UI_Int_Value; | |
652 | end if; | |
653 | ||
654 | -- Scan out exponent | |
655 | ||
656 | if not Point_Scanned then | |
657 | Scale := 0; | |
658 | UI_Scale := Uint_0; | |
659 | else | |
660 | UI_Scale := UI_From_Int (Scale); | |
661 | end if; | |
662 | ||
663 | if Source (Scan_Ptr) = 'e' or else Source (Scan_Ptr) = 'E' then | |
664 | Accumulate_Checksum ('e'); | |
665 | Scan_Ptr := Scan_Ptr + 1; | |
666 | Exponent_Is_Negative := False; | |
667 | ||
668 | if Source (Scan_Ptr) = '+' then | |
669 | Accumulate_Checksum ('+'); | |
670 | Scan_Ptr := Scan_Ptr + 1; | |
671 | ||
672 | elsif Source (Scan_Ptr) = '-' then | |
673 | Accumulate_Checksum ('-'); | |
674 | ||
675 | if not Point_Scanned then | |
676 | Error_Msg_S | |
677 | ("negative exponent not allowed for integer literal"); | |
678 | else | |
679 | Exponent_Is_Negative := True; | |
680 | end if; | |
681 | ||
682 | Scan_Ptr := Scan_Ptr + 1; | |
683 | end if; | |
684 | ||
685 | UI_Int_Value := Uint_0; | |
686 | ||
687 | if Source (Scan_Ptr) in '0' .. '9' then | |
688 | Scan_Integer; | |
689 | else | |
690 | Error_Digit_Expected; | |
691 | end if; | |
692 | ||
693 | if Exponent_Is_Negative then | |
694 | UI_Scale := UI_Scale - UI_Int_Value; | |
695 | else | |
696 | UI_Scale := UI_Scale + UI_Int_Value; | |
697 | end if; | |
698 | end if; | |
699 | ||
700 | -- Case of real literal to be returned | |
701 | ||
702 | if Point_Scanned then | |
703 | Token := Tok_Real_Literal; | |
704 | Real_Literal_Value := | |
705 | UR_From_Components ( | |
706 | Num => UI_Num_Value, | |
707 | Den => -UI_Scale, | |
708 | Rbase => Base); | |
709 | ||
710 | -- Case of integer literal to be returned | |
711 | ||
712 | else | |
713 | Token := Tok_Integer_Literal; | |
714 | ||
715 | if UI_Scale = 0 then | |
716 | Int_Literal_Value := UI_Num_Value; | |
717 | ||
718 | -- Avoid doing possibly expensive calculations in cases like | |
719 | -- parsing 163E800_000# when semantics will not be done anyway. | |
720 | -- This is especially useful when parsing garbled input. | |
721 | ||
722 | elsif Operating_Mode /= Check_Syntax | |
723 | and then (Serious_Errors_Detected = 0 or else Try_Semantics) | |
724 | then | |
725 | Int_Literal_Value := UI_Num_Value * UI_Base ** UI_Scale; | |
726 | ||
727 | else | |
728 | Int_Literal_Value := No_Uint; | |
729 | ||
730 | end if; | |
731 | ||
732 | end if; | |
733 | ||
6b6fcd3e AC |
734 | Accumulate_Token_Checksum; |
735 | ||
fbf5a39b AC |
736 | return; |
737 | ||
738 | end Nlit; | |
739 | ||
740 | ---------- | |
741 | -- Slit -- | |
742 | ---------- | |
743 | ||
744 | procedure Slit is | |
745 | ||
746 | Delimiter : Character; | |
747 | -- Delimiter (first character of string) | |
748 | ||
749 | C : Character; | |
750 | -- Current source program character | |
751 | ||
752 | Code : Char_Code; | |
753 | -- Current character code value | |
754 | ||
755 | Err : Boolean; | |
756 | -- Error flag for Scan_Wide call | |
757 | ||
758 | procedure Error_Bad_String_Char; | |
759 | -- Signal bad character in string/character literal. On entry | |
760 | -- Scan_Ptr points to the improper character encountered during | |
761 | -- the scan. Scan_Ptr is not modified, so it still points to the bad | |
762 | -- character on return. | |
763 | ||
764 | procedure Error_Unterminated_String; | |
765 | -- Procedure called if a line terminator character is encountered | |
766 | -- during scanning a string, meaning that the string is not properly | |
767 | -- terminated. | |
768 | ||
769 | procedure Set_String; | |
770 | -- Procedure used to distinguish between string and operator symbol. | |
771 | -- On entry the string has been scanned out, and its characters start | |
772 | -- at Token_Ptr and end one character before Scan_Ptr. On exit Token | |
773 | -- is set to Tok_String_Literal or Tok_Operator_Symbol as | |
774 | -- appropriate, and Token_Node is appropriately initialized. | |
775 | -- In addition, in the operator symbol case, Token_Name is | |
776 | -- appropriately set. | |
777 | ||
778 | --------------------------- | |
779 | -- Error_Bad_String_Char -- | |
780 | --------------------------- | |
781 | ||
782 | procedure Error_Bad_String_Char is | |
783 | C : constant Character := Source (Scan_Ptr); | |
784 | ||
785 | begin | |
786 | if C = HT then | |
787 | Error_Msg_S ("horizontal tab not allowed in string"); | |
788 | ||
789 | elsif C = VT or else C = FF then | |
790 | Error_Msg_S ("format effector not allowed in string"); | |
791 | ||
792 | elsif C in Upper_Half_Character then | |
793 | Error_Msg_S ("(Ada 83) upper half character not allowed"); | |
794 | ||
795 | else | |
796 | Error_Msg_S ("control character not allowed in string"); | |
797 | end if; | |
798 | end Error_Bad_String_Char; | |
799 | ||
800 | ------------------------------- | |
801 | -- Error_Unterminated_String -- | |
802 | ------------------------------- | |
803 | ||
804 | procedure Error_Unterminated_String is | |
805 | begin | |
806 | -- An interesting little refinement. Consider the following | |
807 | -- examples: | |
808 | ||
809 | -- A := "this is an unterminated string; | |
810 | -- A := "this is an unterminated string & | |
811 | -- P(A, "this is a parameter that didn't get terminated); | |
812 | ||
813 | -- We fiddle a little to do slightly better placement in these | |
814 | -- cases also if there is white space at the end of the line we | |
815 | -- place the flag at the start of this white space, not at the | |
816 | -- end. Note that we only have to test for blanks, since tabs | |
817 | -- aren't allowed in strings in the first place and would have | |
818 | -- caused an error message. | |
819 | ||
820 | -- Two more cases that we treat specially are: | |
821 | ||
822 | -- A := "this string uses the wrong terminator' | |
823 | -- A := "this string uses the wrong terminator' & | |
824 | ||
825 | -- In these cases we give a different error message as well | |
826 | ||
827 | -- We actually reposition the scan pointer to the point where we | |
828 | -- place the flag in these cases, since it seems a better bet on | |
829 | -- the original intention. | |
830 | ||
831 | while Source (Scan_Ptr - 1) = ' ' | |
832 | or else Source (Scan_Ptr - 1) = '&' | |
833 | loop | |
834 | Scan_Ptr := Scan_Ptr - 1; | |
835 | Unstore_String_Char; | |
836 | end loop; | |
837 | ||
838 | -- Check for case of incorrect string terminator, but single quote | |
839 | -- is not considered incorrect if the opening terminator misused | |
840 | -- a single quote (error message already given). | |
841 | ||
842 | if Delimiter /= ''' | |
843 | and then Source (Scan_Ptr - 1) = ''' | |
844 | then | |
845 | Unstore_String_Char; | |
846 | Error_Msg | |
847 | ("incorrect string terminator character", Scan_Ptr - 1); | |
848 | return; | |
849 | end if; | |
850 | ||
851 | if Source (Scan_Ptr - 1) = ';' then | |
852 | Scan_Ptr := Scan_Ptr - 1; | |
853 | Unstore_String_Char; | |
854 | ||
855 | if Source (Scan_Ptr - 1) = ')' then | |
856 | Scan_Ptr := Scan_Ptr - 1; | |
857 | Unstore_String_Char; | |
858 | end if; | |
859 | end if; | |
860 | ||
861 | Error_Msg_S ("missing string quote"); | |
862 | end Error_Unterminated_String; | |
863 | ||
864 | ---------------- | |
865 | -- Set_String -- | |
866 | ---------------- | |
867 | ||
868 | procedure Set_String is | |
869 | Slen : constant Int := Int (Scan_Ptr - Token_Ptr - 2); | |
870 | C1 : Character; | |
871 | C2 : Character; | |
872 | C3 : Character; | |
873 | ||
874 | begin | |
875 | -- Token_Name is currently set to Error_Name. The following | |
876 | -- section of code resets Token_Name to the proper Name_Op_xx | |
877 | -- value if the string is a valid operator symbol, otherwise it is | |
878 | -- left set to Error_Name. | |
879 | ||
880 | if Slen = 1 then | |
881 | C1 := Source (Token_Ptr + 1); | |
882 | ||
883 | case C1 is | |
884 | when '=' => | |
885 | Token_Name := Name_Op_Eq; | |
886 | ||
887 | when '>' => | |
888 | Token_Name := Name_Op_Gt; | |
889 | ||
890 | when '<' => | |
891 | Token_Name := Name_Op_Lt; | |
892 | ||
893 | when '+' => | |
894 | Token_Name := Name_Op_Add; | |
895 | ||
896 | when '-' => | |
897 | Token_Name := Name_Op_Subtract; | |
898 | ||
899 | when '&' => | |
900 | Token_Name := Name_Op_Concat; | |
901 | ||
902 | when '*' => | |
903 | Token_Name := Name_Op_Multiply; | |
904 | ||
905 | when '/' => | |
906 | Token_Name := Name_Op_Divide; | |
907 | ||
908 | when others => | |
909 | null; | |
910 | end case; | |
911 | ||
912 | elsif Slen = 2 then | |
913 | C1 := Source (Token_Ptr + 1); | |
914 | C2 := Source (Token_Ptr + 2); | |
915 | ||
916 | if C1 = '*' and then C2 = '*' then | |
917 | Token_Name := Name_Op_Expon; | |
918 | ||
919 | elsif C2 = '=' then | |
920 | ||
921 | if C1 = '/' then | |
922 | Token_Name := Name_Op_Ne; | |
923 | elsif C1 = '<' then | |
924 | Token_Name := Name_Op_Le; | |
925 | elsif C1 = '>' then | |
926 | Token_Name := Name_Op_Ge; | |
927 | end if; | |
928 | ||
929 | elsif (C1 = 'O' or else C1 = 'o') and then -- OR | |
930 | (C2 = 'R' or else C2 = 'r') | |
931 | then | |
932 | Token_Name := Name_Op_Or; | |
933 | end if; | |
934 | ||
935 | elsif Slen = 3 then | |
936 | C1 := Source (Token_Ptr + 1); | |
937 | C2 := Source (Token_Ptr + 2); | |
938 | C3 := Source (Token_Ptr + 3); | |
939 | ||
940 | if (C1 = 'A' or else C1 = 'a') and then -- AND | |
941 | (C2 = 'N' or else C2 = 'n') and then | |
942 | (C3 = 'D' or else C3 = 'd') | |
943 | then | |
944 | Token_Name := Name_Op_And; | |
945 | ||
946 | elsif (C1 = 'A' or else C1 = 'a') and then -- ABS | |
947 | (C2 = 'B' or else C2 = 'b') and then | |
948 | (C3 = 'S' or else C3 = 's') | |
949 | then | |
950 | Token_Name := Name_Op_Abs; | |
951 | ||
952 | elsif (C1 = 'M' or else C1 = 'm') and then -- MOD | |
953 | (C2 = 'O' or else C2 = 'o') and then | |
954 | (C3 = 'D' or else C3 = 'd') | |
955 | then | |
956 | Token_Name := Name_Op_Mod; | |
957 | ||
958 | elsif (C1 = 'N' or else C1 = 'n') and then -- NOT | |
959 | (C2 = 'O' or else C2 = 'o') and then | |
960 | (C3 = 'T' or else C3 = 't') | |
961 | then | |
962 | Token_Name := Name_Op_Not; | |
963 | ||
964 | elsif (C1 = 'R' or else C1 = 'r') and then -- REM | |
965 | (C2 = 'E' or else C2 = 'e') and then | |
966 | (C3 = 'M' or else C3 = 'm') | |
967 | then | |
968 | Token_Name := Name_Op_Rem; | |
969 | ||
970 | elsif (C1 = 'X' or else C1 = 'x') and then -- XOR | |
971 | (C2 = 'O' or else C2 = 'o') and then | |
972 | (C3 = 'R' or else C3 = 'r') | |
973 | then | |
974 | Token_Name := Name_Op_Xor; | |
975 | end if; | |
976 | ||
977 | end if; | |
978 | ||
979 | -- If it is an operator symbol, then Token_Name is set. | |
980 | -- If it is some other string value, then Token_Name still | |
981 | -- contains Error_Name. | |
982 | ||
983 | if Token_Name = Error_Name then | |
984 | Token := Tok_String_Literal; | |
985 | ||
986 | else | |
987 | Token := Tok_Operator_Symbol; | |
988 | end if; | |
989 | ||
990 | end Set_String; | |
991 | ||
992 | ---------- | |
993 | -- Slit -- | |
994 | ---------- | |
995 | ||
996 | begin | |
997 | -- On entry, Scan_Ptr points to the opening character of the string | |
998 | -- which is either a percent, double quote, or apostrophe | |
999 | -- (single quote). The latter case is an error detected by | |
1000 | -- the character literal circuit. | |
1001 | ||
1002 | Delimiter := Source (Scan_Ptr); | |
1003 | Accumulate_Checksum (Delimiter); | |
1004 | Start_String; | |
1005 | Scan_Ptr := Scan_Ptr + 1; | |
1006 | ||
1007 | -- Loop to scan out characters of string literal | |
1008 | ||
1009 | loop | |
1010 | C := Source (Scan_Ptr); | |
1011 | ||
1012 | if C = Delimiter then | |
1013 | Accumulate_Checksum (C); | |
1014 | Scan_Ptr := Scan_Ptr + 1; | |
1015 | exit when Source (Scan_Ptr) /= Delimiter; | |
1016 | Code := Get_Char_Code (C); | |
1017 | Accumulate_Checksum (C); | |
1018 | Scan_Ptr := Scan_Ptr + 1; | |
1019 | ||
1020 | else | |
1021 | if C = '"' and then Delimiter = '%' then | |
1022 | Error_Msg_S | |
1023 | ("quote not allowed in percent delimited string"); | |
1024 | Code := Get_Char_Code (C); | |
1025 | Scan_Ptr := Scan_Ptr + 1; | |
1026 | ||
1027 | elsif (C = ESC | |
1028 | and then | |
1029 | Wide_Character_Encoding_Method | |
1030 | in WC_ESC_Encoding_Method) | |
1031 | or else | |
1032 | (C in Upper_Half_Character | |
1033 | and then | |
1034 | Upper_Half_Encoding) | |
1035 | or else | |
1036 | (C = '[' | |
1037 | and then | |
1038 | Source (Scan_Ptr + 1) = '"' | |
1039 | and then | |
1040 | Identifier_Char (Source (Scan_Ptr + 2))) | |
1041 | then | |
1042 | Scan_Wide (Source, Scan_Ptr, Code, Err); | |
1043 | Accumulate_Checksum (Code); | |
1044 | ||
1045 | if Err then | |
1046 | Error_Illegal_Wide_Character; | |
1047 | Code := Get_Char_Code (' '); | |
1048 | end if; | |
1049 | ||
1050 | else | |
1051 | Accumulate_Checksum (C); | |
1052 | ||
1053 | if C not in Graphic_Character then | |
1054 | if C in Line_Terminator then | |
1055 | Error_Unterminated_String; | |
1056 | exit; | |
1057 | ||
1058 | elsif C in Upper_Half_Character then | |
0ab80019 | 1059 | if Ada_Version = Ada_83 then |
fbf5a39b AC |
1060 | Error_Bad_String_Char; |
1061 | end if; | |
1062 | ||
1063 | else | |
1064 | Error_Bad_String_Char; | |
1065 | end if; | |
1066 | end if; | |
1067 | ||
1068 | Code := Get_Char_Code (C); | |
1069 | Scan_Ptr := Scan_Ptr + 1; | |
1070 | end if; | |
1071 | end if; | |
1072 | ||
1073 | Store_String_Char (Code); | |
1074 | ||
1075 | if not In_Character_Range (Code) then | |
1076 | Wide_Character_Found := True; | |
1077 | end if; | |
1078 | end loop; | |
1079 | ||
1080 | String_Literal_Id := End_String; | |
1081 | Set_String; | |
1082 | return; | |
1083 | ||
1084 | end Slit; | |
1085 | ||
1086 | -- Start of body of Scan | |
1087 | ||
1088 | begin | |
1089 | Prev_Token := Token; | |
1090 | Prev_Token_Ptr := Token_Ptr; | |
1091 | Token_Name := Error_Name; | |
1092 | ||
1093 | -- The following loop runs more than once only if a format effector | |
1094 | -- (tab, vertical tab, form feed, line feed, carriage return) is | |
1095 | -- encountered and skipped, or some error situation, such as an | |
1096 | -- illegal character, is encountered. | |
1097 | ||
1098 | loop | |
1099 | -- Skip past blanks, loop is opened up for speed | |
1100 | ||
1101 | while Source (Scan_Ptr) = ' ' loop | |
1102 | ||
1103 | if Source (Scan_Ptr + 1) /= ' ' then | |
1104 | Scan_Ptr := Scan_Ptr + 1; | |
1105 | exit; | |
1106 | end if; | |
1107 | ||
1108 | if Source (Scan_Ptr + 2) /= ' ' then | |
1109 | Scan_Ptr := Scan_Ptr + 2; | |
1110 | exit; | |
1111 | end if; | |
1112 | ||
1113 | if Source (Scan_Ptr + 3) /= ' ' then | |
1114 | Scan_Ptr := Scan_Ptr + 3; | |
1115 | exit; | |
1116 | end if; | |
1117 | ||
1118 | if Source (Scan_Ptr + 4) /= ' ' then | |
1119 | Scan_Ptr := Scan_Ptr + 4; | |
1120 | exit; | |
1121 | end if; | |
1122 | ||
1123 | if Source (Scan_Ptr + 5) /= ' ' then | |
1124 | Scan_Ptr := Scan_Ptr + 5; | |
1125 | exit; | |
1126 | end if; | |
1127 | ||
1128 | if Source (Scan_Ptr + 6) /= ' ' then | |
1129 | Scan_Ptr := Scan_Ptr + 6; | |
1130 | exit; | |
1131 | end if; | |
1132 | ||
1133 | if Source (Scan_Ptr + 7) /= ' ' then | |
1134 | Scan_Ptr := Scan_Ptr + 7; | |
1135 | exit; | |
1136 | end if; | |
1137 | ||
1138 | Scan_Ptr := Scan_Ptr + 8; | |
1139 | end loop; | |
1140 | ||
1141 | -- We are now at a non-blank character, which is the first character | |
1142 | -- of the token we will scan, and hence the value of Token_Ptr. | |
1143 | ||
1144 | Token_Ptr := Scan_Ptr; | |
1145 | ||
1146 | -- Here begins the main case statement which transfers control on | |
1147 | -- the basis of the non-blank character we have encountered. | |
1148 | ||
1149 | case Source (Scan_Ptr) is | |
1150 | ||
1151 | -- Line terminator characters | |
1152 | ||
1153 | when CR | LF | FF | VT => Line_Terminator_Case : begin | |
1154 | ||
1155 | -- Check line too long | |
1156 | ||
1157 | Check_End_Of_Line; | |
1158 | ||
1159 | -- Set Token_Ptr, if End_Of_Line is a token, for the case when | |
1160 | -- it is a physical line. | |
1161 | ||
1162 | if End_Of_Line_Is_Token then | |
1163 | Token_Ptr := Scan_Ptr; | |
1164 | end if; | |
1165 | ||
1166 | declare | |
1167 | Physical : Boolean; | |
1168 | ||
1169 | begin | |
1170 | Skip_Line_Terminators (Scan_Ptr, Physical); | |
1171 | ||
1172 | -- If we are at start of physical line, update scan pointers | |
1173 | -- to reflect the start of the new line. | |
1174 | ||
1175 | if Physical then | |
1176 | Current_Line_Start := Scan_Ptr; | |
1177 | Start_Column := Set_Start_Column; | |
1178 | First_Non_Blank_Location := Scan_Ptr; | |
1179 | ||
1180 | -- If End_Of_Line is a token, we return it as it is | |
1181 | -- a physical line. | |
1182 | ||
1183 | if End_Of_Line_Is_Token then | |
1184 | Token := Tok_End_Of_Line; | |
1185 | return; | |
1186 | end if; | |
1187 | end if; | |
1188 | end; | |
1189 | end Line_Terminator_Case; | |
1190 | ||
1191 | -- Horizontal tab, just skip past it | |
1192 | ||
1193 | when HT => | |
1194 | if Style_Check then Style.Check_HT; end if; | |
1195 | Scan_Ptr := Scan_Ptr + 1; | |
1196 | ||
1197 | -- End of file character, treated as an end of file only if it | |
1198 | -- is the last character in the buffer, otherwise it is ignored. | |
1199 | ||
1200 | when EOF => | |
1201 | if Scan_Ptr = Source_Last (Current_Source_File) then | |
1202 | Check_End_Of_Line; | |
1203 | Token := Tok_EOF; | |
1204 | return; | |
1205 | ||
1206 | else | |
1207 | Scan_Ptr := Scan_Ptr + 1; | |
1208 | end if; | |
1209 | ||
1210 | -- Ampersand | |
1211 | ||
1212 | when '&' => | |
1213 | Accumulate_Checksum ('&'); | |
1214 | ||
1215 | if Source (Scan_Ptr + 1) = '&' then | |
1216 | Error_Msg_S ("'&'& should be `AND THEN`"); | |
1217 | Scan_Ptr := Scan_Ptr + 2; | |
1218 | Token := Tok_And; | |
1219 | return; | |
1220 | ||
1221 | else | |
1222 | Scan_Ptr := Scan_Ptr + 1; | |
1223 | Token := Tok_Ampersand; | |
1224 | return; | |
1225 | end if; | |
1226 | ||
1227 | -- Asterisk (can be multiplication operator or double asterisk | |
1228 | -- which is the exponentiation compound delimiter). | |
1229 | ||
1230 | when '*' => | |
1231 | Accumulate_Checksum ('*'); | |
1232 | ||
1233 | if Source (Scan_Ptr + 1) = '*' then | |
1234 | Accumulate_Checksum ('*'); | |
1235 | Scan_Ptr := Scan_Ptr + 2; | |
1236 | Token := Tok_Double_Asterisk; | |
1237 | return; | |
1238 | ||
1239 | else | |
1240 | Scan_Ptr := Scan_Ptr + 1; | |
1241 | Token := Tok_Asterisk; | |
1242 | return; | |
1243 | end if; | |
1244 | ||
1245 | -- Colon, which can either be an isolated colon, or part of an | |
1246 | -- assignment compound delimiter. | |
1247 | ||
1248 | when ':' => | |
1249 | Accumulate_Checksum (':'); | |
1250 | ||
1251 | if Double_Char_Token ('=') then | |
1252 | Token := Tok_Colon_Equal; | |
1253 | if Style_Check then Style.Check_Colon_Equal; end if; | |
1254 | return; | |
1255 | ||
1256 | elsif Source (Scan_Ptr + 1) = '-' | |
1257 | and then Source (Scan_Ptr + 2) /= '-' | |
1258 | then | |
1259 | Token := Tok_Colon_Equal; | |
1260 | Error_Msg (":- should be :=", Scan_Ptr); | |
1261 | Scan_Ptr := Scan_Ptr + 2; | |
1262 | return; | |
1263 | ||
1264 | else | |
1265 | Scan_Ptr := Scan_Ptr + 1; | |
1266 | Token := Tok_Colon; | |
1267 | if Style_Check then Style.Check_Colon; end if; | |
1268 | return; | |
1269 | end if; | |
1270 | ||
1271 | -- Left parenthesis | |
1272 | ||
1273 | when '(' => | |
1274 | Accumulate_Checksum ('('); | |
1275 | Scan_Ptr := Scan_Ptr + 1; | |
1276 | Token := Tok_Left_Paren; | |
1277 | if Style_Check then Style.Check_Left_Paren; end if; | |
1278 | return; | |
1279 | ||
1280 | -- Left bracket | |
1281 | ||
1282 | when '[' => | |
1283 | if Source (Scan_Ptr + 1) = '"' then | |
1284 | Name_Len := 0; | |
1285 | goto Scan_Identifier; | |
1286 | ||
1287 | else | |
1288 | Error_Msg_S ("illegal character, replaced by ""("""); | |
1289 | Scan_Ptr := Scan_Ptr + 1; | |
1290 | Token := Tok_Left_Paren; | |
1291 | return; | |
1292 | end if; | |
1293 | ||
1294 | -- Left brace | |
1295 | ||
1296 | when '{' => | |
1297 | Error_Msg_S ("illegal character, replaced by ""("""); | |
1298 | Scan_Ptr := Scan_Ptr + 1; | |
1299 | Token := Tok_Left_Paren; | |
1300 | return; | |
1301 | ||
1302 | -- Comma | |
1303 | ||
1304 | when ',' => | |
1305 | Accumulate_Checksum (','); | |
1306 | Scan_Ptr := Scan_Ptr + 1; | |
1307 | Token := Tok_Comma; | |
1308 | if Style_Check then Style.Check_Comma; end if; | |
1309 | return; | |
1310 | ||
1311 | -- Dot, which is either an isolated period, or part of a double | |
1312 | -- dot compound delimiter sequence. We also check for the case of | |
1313 | -- a digit following the period, to give a better error message. | |
1314 | ||
1315 | when '.' => | |
1316 | Accumulate_Checksum ('.'); | |
1317 | ||
1318 | if Double_Char_Token ('.') then | |
1319 | Token := Tok_Dot_Dot; | |
1320 | if Style_Check then Style.Check_Dot_Dot; end if; | |
1321 | return; | |
1322 | ||
1323 | elsif Source (Scan_Ptr + 1) in '0' .. '9' then | |
1324 | Error_Msg_S ("numeric literal cannot start with point"); | |
1325 | Scan_Ptr := Scan_Ptr + 1; | |
1326 | ||
1327 | else | |
1328 | Scan_Ptr := Scan_Ptr + 1; | |
1329 | Token := Tok_Dot; | |
1330 | return; | |
1331 | end if; | |
1332 | ||
1333 | -- Equal, which can either be an equality operator, or part of the | |
1334 | -- arrow (=>) compound delimiter. | |
1335 | ||
1336 | when '=' => | |
1337 | Accumulate_Checksum ('='); | |
1338 | ||
1339 | if Double_Char_Token ('>') then | |
1340 | Token := Tok_Arrow; | |
1341 | if Style_Check then Style.Check_Arrow; end if; | |
1342 | return; | |
1343 | ||
1344 | elsif Source (Scan_Ptr + 1) = '=' then | |
1345 | Error_Msg_S ("== should be ="); | |
1346 | Scan_Ptr := Scan_Ptr + 1; | |
1347 | end if; | |
1348 | ||
1349 | Scan_Ptr := Scan_Ptr + 1; | |
1350 | Token := Tok_Equal; | |
1351 | return; | |
1352 | ||
1353 | -- Greater than, which can be a greater than operator, greater than | |
1354 | -- or equal operator, or first character of a right label bracket. | |
1355 | ||
1356 | when '>' => | |
1357 | Accumulate_Checksum ('>'); | |
1358 | ||
1359 | if Double_Char_Token ('=') then | |
1360 | Token := Tok_Greater_Equal; | |
1361 | return; | |
1362 | ||
1363 | elsif Double_Char_Token ('>') then | |
1364 | Token := Tok_Greater_Greater; | |
1365 | return; | |
1366 | ||
1367 | else | |
1368 | Scan_Ptr := Scan_Ptr + 1; | |
1369 | Token := Tok_Greater; | |
1370 | return; | |
1371 | end if; | |
1372 | ||
1373 | -- Less than, which can be a less than operator, less than or equal | |
1374 | -- operator, or the first character of a left label bracket, or the | |
1375 | -- first character of a box (<>) compound delimiter. | |
1376 | ||
1377 | when '<' => | |
1378 | Accumulate_Checksum ('<'); | |
1379 | ||
1380 | if Double_Char_Token ('=') then | |
1381 | Token := Tok_Less_Equal; | |
1382 | return; | |
1383 | ||
1384 | elsif Double_Char_Token ('>') then | |
1385 | Token := Tok_Box; | |
1386 | if Style_Check then Style.Check_Box; end if; | |
1387 | return; | |
1388 | ||
1389 | elsif Double_Char_Token ('<') then | |
1390 | Token := Tok_Less_Less; | |
1391 | return; | |
1392 | ||
1393 | else | |
1394 | Scan_Ptr := Scan_Ptr + 1; | |
1395 | Token := Tok_Less; | |
1396 | return; | |
1397 | end if; | |
1398 | ||
1399 | -- Minus, which is either a subtraction operator, or the first | |
1400 | -- character of double minus starting a comment | |
1401 | ||
1402 | when '-' => Minus_Case : begin | |
1403 | if Source (Scan_Ptr + 1) = '>' then | |
1404 | Error_Msg_S ("invalid token"); | |
1405 | Scan_Ptr := Scan_Ptr + 2; | |
1406 | Token := Tok_Arrow; | |
1407 | return; | |
1408 | ||
1409 | elsif Source (Scan_Ptr + 1) /= '-' then | |
1410 | Accumulate_Checksum ('-'); | |
1411 | Scan_Ptr := Scan_Ptr + 1; | |
1412 | Token := Tok_Minus; | |
1413 | return; | |
1414 | ||
1415 | -- Comment | |
1416 | ||
1417 | else -- Source (Scan_Ptr + 1) = '-' then | |
1418 | if Style_Check then Style.Check_Comment; end if; | |
1419 | Scan_Ptr := Scan_Ptr + 2; | |
c45b6ae0 | 1420 | Start_Of_Comment := Scan_Ptr; |
fbf5a39b AC |
1421 | |
1422 | -- Loop to scan comment (this loop runs more than once only if | |
1423 | -- a horizontal tab or other non-graphic character is scanned) | |
1424 | ||
1425 | loop | |
1426 | -- Scan to non graphic character (opened up for speed) | |
1427 | ||
1428 | loop | |
1429 | exit when Source (Scan_Ptr) not in Graphic_Character; | |
1430 | Scan_Ptr := Scan_Ptr + 1; | |
1431 | exit when Source (Scan_Ptr) not in Graphic_Character; | |
1432 | Scan_Ptr := Scan_Ptr + 1; | |
1433 | exit when Source (Scan_Ptr) not in Graphic_Character; | |
1434 | Scan_Ptr := Scan_Ptr + 1; | |
1435 | exit when Source (Scan_Ptr) not in Graphic_Character; | |
1436 | Scan_Ptr := Scan_Ptr + 1; | |
1437 | exit when Source (Scan_Ptr) not in Graphic_Character; | |
1438 | Scan_Ptr := Scan_Ptr + 1; | |
1439 | end loop; | |
1440 | ||
1441 | -- Keep going if horizontal tab | |
1442 | ||
1443 | if Source (Scan_Ptr) = HT then | |
1444 | if Style_Check then Style.Check_HT; end if; | |
1445 | Scan_Ptr := Scan_Ptr + 1; | |
1446 | ||
1447 | -- Terminate scan of comment if line terminator | |
1448 | ||
1449 | elsif Source (Scan_Ptr) in Line_Terminator then | |
1450 | exit; | |
1451 | ||
1452 | -- Terminate scan of comment if end of file encountered | |
1453 | -- (embedded EOF character or real last character in file) | |
1454 | ||
1455 | elsif Source (Scan_Ptr) = EOF then | |
1456 | exit; | |
1457 | ||
1458 | -- Keep going if character in 80-FF range, or is ESC. These | |
1459 | -- characters are allowed in comments by RM-2.1(1), 2.7(2). | |
1460 | -- They are allowed even in Ada 83 mode according to the | |
1461 | -- approved AI. ESC was added to the AI in June 93. | |
1462 | ||
1463 | elsif Source (Scan_Ptr) in Upper_Half_Character | |
1464 | or else Source (Scan_Ptr) = ESC | |
1465 | then | |
1466 | Scan_Ptr := Scan_Ptr + 1; | |
1467 | ||
1468 | -- Otherwise we have an illegal comment character | |
1469 | ||
1470 | else | |
1471 | Error_Illegal_Character; | |
1472 | end if; | |
1473 | ||
1474 | end loop; | |
1475 | ||
c45b6ae0 AC |
1476 | -- Note that, except when comments are tokens, we do NOT |
1477 | -- execute a return here, instead we fall through to reexecute | |
1478 | -- the scan loop to look for a token. | |
1479 | ||
1480 | if Comment_Is_Token then | |
1481 | Name_Len := Integer (Scan_Ptr - Start_Of_Comment); | |
1482 | Name_Buffer (1 .. Name_Len) := | |
1483 | String (Source (Start_Of_Comment .. Scan_Ptr - 1)); | |
1484 | Comment_Id := Name_Find; | |
1485 | Token := Tok_Comment; | |
1486 | return; | |
1487 | end if; | |
fbf5a39b AC |
1488 | end if; |
1489 | end Minus_Case; | |
1490 | ||
1491 | -- Double quote starting a string literal | |
1492 | ||
1493 | when '"' => | |
1494 | Slit; | |
1495 | Post_Scan; | |
1496 | return; | |
1497 | ||
1498 | -- Percent starting a string literal | |
1499 | ||
1500 | when '%' => | |
1501 | if Warn_On_Obsolescent_Feature then | |
1502 | Error_Msg_S | |
1503 | ("use of ""'%"" is an obsolescent feature ('R'M 'J.2(4))?"); | |
1504 | Error_Msg_S | |
1505 | ("\use """""" instead?"); | |
1506 | end if; | |
1507 | ||
1508 | Slit; | |
1509 | Post_Scan; | |
1510 | return; | |
1511 | ||
1512 | -- Apostrophe. This can either be the start of a character literal, | |
1513 | -- or an isolated apostrophe used in a qualified expression or an | |
1514 | -- attribute. We treat it as a character literal if it does not | |
1515 | -- follow a right parenthesis, identifier, the keyword ALL or | |
1516 | -- a literal. This means that we correctly treat constructs like: | |
1517 | ||
1518 | -- A := CHARACTER'('A'); | |
1519 | ||
1520 | -- Note that RM-2.2(7) does not require a separator between | |
1521 | -- "CHARACTER" and "'" in the above. | |
1522 | ||
1523 | when ''' => Char_Literal_Case : declare | |
1524 | Code : Char_Code; | |
1525 | Err : Boolean; | |
1526 | ||
1527 | begin | |
1528 | Accumulate_Checksum ('''); | |
1529 | Scan_Ptr := Scan_Ptr + 1; | |
1530 | ||
1531 | -- Here is where we make the test to distinguish the cases. Treat | |
1532 | -- as apostrophe if previous token is an identifier, right paren | |
1533 | -- or the reserved word "all" (latter case as in A.all'Address) | |
1534 | -- (or the reserved word "project" in project files). | |
1535 | -- Also treat it as apostrophe after a literal (this catches | |
1536 | -- some legitimate cases, like A."abs"'Address, and also gives | |
1537 | -- better error behavior for impossible cases like 123'xxx). | |
1538 | ||
1539 | if Prev_Token = Tok_Identifier | |
1540 | or else Prev_Token = Tok_Right_Paren | |
1541 | or else Prev_Token = Tok_All | |
1542 | or else Prev_Token = Tok_Project | |
1543 | or else Prev_Token in Token_Class_Literal | |
1544 | then | |
1545 | Token := Tok_Apostrophe; | |
1546 | if Style_Check then Style.Check_Apostrophe; end if; | |
1547 | return; | |
1548 | ||
1549 | -- Otherwise the apostrophe starts a character literal | |
1550 | ||
1551 | else | |
1552 | -- Case of wide character literal with ESC or [ encoding | |
1553 | ||
1554 | if (Source (Scan_Ptr) = ESC | |
1555 | and then | |
1556 | Wide_Character_Encoding_Method in WC_ESC_Encoding_Method) | |
1557 | or else | |
1558 | (Source (Scan_Ptr) in Upper_Half_Character | |
1559 | and then | |
1560 | Upper_Half_Encoding) | |
1561 | or else | |
1562 | (Source (Scan_Ptr) = '[' | |
1563 | and then | |
1564 | Source (Scan_Ptr + 1) = '"') | |
1565 | then | |
1566 | Scan_Wide (Source, Scan_Ptr, Code, Err); | |
1567 | Accumulate_Checksum (Code); | |
1568 | ||
1569 | if Err then | |
1570 | Error_Illegal_Wide_Character; | |
1571 | end if; | |
1572 | ||
1573 | if Source (Scan_Ptr) /= ''' then | |
1574 | Error_Msg_S ("missing apostrophe"); | |
1575 | else | |
1576 | Scan_Ptr := Scan_Ptr + 1; | |
1577 | end if; | |
1578 | ||
1579 | -- If we do not find a closing quote in the expected place then | |
1580 | -- assume that we have a misguided attempt at a string literal. | |
1581 | ||
1582 | -- However, if previous token is RANGE, then we return an | |
1583 | -- apostrophe instead since this gives better error recovery | |
1584 | ||
1585 | elsif Source (Scan_Ptr + 1) /= ''' then | |
1586 | ||
1587 | if Prev_Token = Tok_Range then | |
1588 | Token := Tok_Apostrophe; | |
1589 | return; | |
1590 | ||
1591 | else | |
1592 | Scan_Ptr := Scan_Ptr - 1; | |
1593 | Error_Msg_S | |
1594 | ("strings are delimited by double quote character"); | |
1595 | Slit; | |
1596 | Post_Scan; | |
1597 | return; | |
1598 | end if; | |
1599 | ||
1600 | -- Otherwise we have a (non-wide) character literal | |
1601 | ||
1602 | else | |
1603 | Accumulate_Checksum (Source (Scan_Ptr)); | |
1604 | ||
1605 | if Source (Scan_Ptr) not in Graphic_Character then | |
1606 | if Source (Scan_Ptr) in Upper_Half_Character then | |
0ab80019 | 1607 | if Ada_Version = Ada_83 then |
fbf5a39b AC |
1608 | Error_Illegal_Character; |
1609 | end if; | |
1610 | ||
1611 | else | |
1612 | Error_Illegal_Character; | |
1613 | end if; | |
1614 | end if; | |
1615 | ||
1616 | Code := Get_Char_Code (Source (Scan_Ptr)); | |
1617 | Scan_Ptr := Scan_Ptr + 2; | |
1618 | end if; | |
1619 | ||
1620 | -- Fall through here with Scan_Ptr updated past the closing | |
1621 | -- quote, and Code set to the Char_Code value for the literal | |
1622 | ||
1623 | Accumulate_Checksum ('''); | |
1624 | Token := Tok_Char_Literal; | |
1625 | Set_Character_Literal_Name (Code); | |
1626 | Token_Name := Name_Find; | |
1627 | Character_Code := Code; | |
1628 | Post_Scan; | |
1629 | return; | |
1630 | end if; | |
1631 | end Char_Literal_Case; | |
1632 | ||
1633 | -- Right parenthesis | |
1634 | ||
1635 | when ')' => | |
1636 | Accumulate_Checksum (')'); | |
1637 | Scan_Ptr := Scan_Ptr + 1; | |
1638 | Token := Tok_Right_Paren; | |
1639 | if Style_Check then Style.Check_Right_Paren; end if; | |
1640 | return; | |
1641 | ||
1642 | -- Right bracket or right brace, treated as right paren | |
1643 | ||
1644 | when ']' | '}' => | |
1645 | Error_Msg_S ("illegal character, replaced by "")"""); | |
1646 | Scan_Ptr := Scan_Ptr + 1; | |
1647 | Token := Tok_Right_Paren; | |
1648 | return; | |
1649 | ||
1650 | -- Slash (can be division operator or first character of not equal) | |
1651 | ||
1652 | when '/' => | |
1653 | Accumulate_Checksum ('/'); | |
1654 | ||
1655 | if Double_Char_Token ('=') then | |
1656 | Token := Tok_Not_Equal; | |
1657 | return; | |
1658 | else | |
1659 | Scan_Ptr := Scan_Ptr + 1; | |
1660 | Token := Tok_Slash; | |
1661 | return; | |
1662 | end if; | |
1663 | ||
1664 | -- Semicolon | |
1665 | ||
1666 | when ';' => | |
1667 | Accumulate_Checksum (';'); | |
1668 | Scan_Ptr := Scan_Ptr + 1; | |
1669 | Token := Tok_Semicolon; | |
1670 | if Style_Check then Style.Check_Semicolon; end if; | |
1671 | return; | |
1672 | ||
1673 | -- Vertical bar | |
1674 | ||
1675 | when '|' => Vertical_Bar_Case : begin | |
1676 | Accumulate_Checksum ('|'); | |
1677 | ||
1678 | -- Special check for || to give nice message | |
1679 | ||
1680 | if Source (Scan_Ptr + 1) = '|' then | |
1681 | Error_Msg_S ("""'|'|"" should be `OR ELSE`"); | |
1682 | Scan_Ptr := Scan_Ptr + 2; | |
1683 | Token := Tok_Or; | |
1684 | return; | |
1685 | ||
1686 | else | |
1687 | Scan_Ptr := Scan_Ptr + 1; | |
1688 | Token := Tok_Vertical_Bar; | |
1689 | if Style_Check then Style.Check_Vertical_Bar; end if; | |
1690 | return; | |
1691 | end if; | |
1692 | end Vertical_Bar_Case; | |
1693 | ||
1694 | -- Exclamation, replacement character for vertical bar | |
1695 | ||
1696 | when '!' => Exclamation_Case : begin | |
1697 | Accumulate_Checksum ('!'); | |
1698 | ||
1699 | if Warn_On_Obsolescent_Feature then | |
1700 | Error_Msg_S | |
1701 | ("use of ""'!"" is an obsolescent feature ('R'M 'J.2(2))?"); | |
1702 | Error_Msg_S | |
1703 | ("\use ""'|"" instead?"); | |
1704 | end if; | |
1705 | ||
1706 | if Source (Scan_Ptr + 1) = '=' then | |
1707 | Error_Msg_S ("'!= should be /="); | |
1708 | Scan_Ptr := Scan_Ptr + 2; | |
1709 | Token := Tok_Not_Equal; | |
1710 | return; | |
1711 | ||
1712 | else | |
1713 | Scan_Ptr := Scan_Ptr + 1; | |
1714 | Token := Tok_Vertical_Bar; | |
1715 | return; | |
1716 | end if; | |
1717 | ||
1718 | end Exclamation_Case; | |
1719 | ||
1720 | -- Plus | |
1721 | ||
1722 | when '+' => Plus_Case : begin | |
1723 | Accumulate_Checksum ('+'); | |
1724 | Scan_Ptr := Scan_Ptr + 1; | |
1725 | Token := Tok_Plus; | |
1726 | return; | |
1727 | end Plus_Case; | |
1728 | ||
1729 | -- Digits starting a numeric literal | |
1730 | ||
1731 | when '0' .. '9' => | |
1732 | Nlit; | |
1733 | ||
1734 | if Identifier_Char (Source (Scan_Ptr)) then | |
1735 | Error_Msg_S | |
1736 | ("delimiter required between literal and identifier"); | |
1737 | end if; | |
1738 | Post_Scan; | |
1739 | return; | |
1740 | ||
1741 | -- Lower case letters | |
1742 | ||
1743 | when 'a' .. 'z' => | |
1744 | Name_Len := 1; | |
1745 | Name_Buffer (1) := Source (Scan_Ptr); | |
1746 | Accumulate_Checksum (Name_Buffer (1)); | |
1747 | Scan_Ptr := Scan_Ptr + 1; | |
1748 | goto Scan_Identifier; | |
1749 | ||
1750 | -- Upper case letters | |
1751 | ||
1752 | when 'A' .. 'Z' => | |
1753 | Name_Len := 1; | |
1754 | Name_Buffer (1) := | |
1755 | Character'Val (Character'Pos (Source (Scan_Ptr)) + 32); | |
1756 | Accumulate_Checksum (Name_Buffer (1)); | |
1757 | Scan_Ptr := Scan_Ptr + 1; | |
1758 | goto Scan_Identifier; | |
1759 | ||
1760 | -- Underline character | |
1761 | ||
1762 | when '_' => | |
1763 | if Special_Characters ('_') then | |
1764 | Token_Ptr := Scan_Ptr; | |
1765 | Scan_Ptr := Scan_Ptr + 1; | |
1766 | Token := Tok_Special; | |
1767 | Special_Character := '_'; | |
1768 | return; | |
1769 | end if; | |
1770 | ||
1771 | Error_Msg_S ("identifier cannot start with underline"); | |
1772 | Name_Len := 1; | |
1773 | Name_Buffer (1) := '_'; | |
1774 | Scan_Ptr := Scan_Ptr + 1; | |
1775 | goto Scan_Identifier; | |
1776 | ||
1777 | -- Space (not possible, because we scanned past blanks) | |
1778 | ||
1779 | when ' ' => | |
1780 | raise Program_Error; | |
1781 | ||
1782 | -- Characters in top half of ASCII 8-bit chart | |
1783 | ||
1784 | when Upper_Half_Character => | |
1785 | ||
1786 | -- Wide character case. Note that Scan_Identifier will issue | |
1787 | -- an appropriate message if wide characters are not allowed | |
1788 | -- in identifiers. | |
1789 | ||
1790 | if Upper_Half_Encoding then | |
1791 | Name_Len := 0; | |
1792 | goto Scan_Identifier; | |
1793 | ||
1794 | -- Otherwise we have OK Latin-1 character | |
1795 | ||
1796 | else | |
1797 | -- Upper half characters may possibly be identifier letters | |
1798 | -- but can never be digits, so Identifier_Char can be used | |
1799 | -- to test for a valid start of identifier character. | |
1800 | ||
1801 | if Identifier_Char (Source (Scan_Ptr)) then | |
1802 | Name_Len := 0; | |
1803 | goto Scan_Identifier; | |
1804 | else | |
1805 | Error_Illegal_Character; | |
1806 | end if; | |
1807 | end if; | |
1808 | ||
1809 | when ESC => | |
1810 | ||
1811 | -- ESC character, possible start of identifier if wide characters | |
1812 | -- using ESC encoding are allowed in identifiers, which we can | |
1813 | -- tell by looking at the Identifier_Char flag for ESC, which is | |
1814 | -- only true if these conditions are met. | |
1815 | ||
1816 | if Identifier_Char (ESC) then | |
1817 | Name_Len := 0; | |
1818 | goto Scan_Identifier; | |
1819 | else | |
1820 | Error_Illegal_Wide_Character; | |
1821 | end if; | |
1822 | ||
1823 | -- Invalid control characters | |
1824 | ||
1825 | when NUL | SOH | STX | ETX | EOT | ENQ | ACK | BEL | BS | SO | | |
1826 | SI | DLE | DC1 | DC2 | DC3 | DC4 | NAK | SYN | ETB | CAN | | |
1827 | EM | FS | GS | RS | US | DEL | |
1828 | => | |
1829 | Error_Illegal_Character; | |
1830 | ||
1831 | -- Invalid graphic characters | |
1832 | ||
1833 | when '#' | '$' | '?' | '@' | '`' | '\' | '^' | '~' => | |
1834 | -- If Set_Special_Character has been called for this character, | |
1835 | -- set Scans.Special_Character and return a Special token. | |
1836 | ||
1837 | if Special_Characters (Source (Scan_Ptr)) then | |
1838 | Token_Ptr := Scan_Ptr; | |
1839 | Token := Tok_Special; | |
1840 | Special_Character := Source (Scan_Ptr); | |
1841 | Scan_Ptr := Scan_Ptr + 1; | |
1842 | return; | |
1843 | ||
1844 | -- otherwise, this is an illegal character | |
1845 | ||
1846 | else | |
1847 | Error_Illegal_Character; | |
1848 | end if; | |
1849 | ||
1850 | -- End switch on non-blank character | |
1851 | ||
1852 | end case; | |
1853 | ||
1854 | -- End loop past format effectors. The exit from this loop is by | |
1855 | -- executing a return statement following completion of token scan | |
1856 | -- (control never falls out of this loop to the code which follows) | |
1857 | ||
1858 | end loop; | |
1859 | ||
1860 | -- Identifier scanning routine. On entry, some initial characters | |
1861 | -- of the identifier may have already been stored in Name_Buffer. | |
1862 | -- If so, Name_Len has the number of characters stored. otherwise | |
1863 | -- Name_Len is set to zero on entry. | |
1864 | ||
1865 | <<Scan_Identifier>> | |
1866 | ||
1867 | -- This loop scans as fast as possible past lower half letters | |
1868 | -- and digits, which we expect to be the most common characters. | |
1869 | ||
1870 | loop | |
1871 | if Source (Scan_Ptr) in 'a' .. 'z' | |
1872 | or else Source (Scan_Ptr) in '0' .. '9' | |
1873 | then | |
1874 | Name_Buffer (Name_Len + 1) := Source (Scan_Ptr); | |
1875 | Accumulate_Checksum (Source (Scan_Ptr)); | |
1876 | ||
1877 | elsif Source (Scan_Ptr) in 'A' .. 'Z' then | |
1878 | Name_Buffer (Name_Len + 1) := | |
1879 | Character'Val (Character'Pos (Source (Scan_Ptr)) + 32); | |
1880 | Accumulate_Checksum (Name_Buffer (Name_Len + 1)); | |
1881 | else | |
1882 | exit; | |
1883 | end if; | |
1884 | ||
1885 | -- Open out the loop a couple of times for speed | |
1886 | ||
1887 | if Source (Scan_Ptr + 1) in 'a' .. 'z' | |
1888 | or else Source (Scan_Ptr + 1) in '0' .. '9' | |
1889 | then | |
1890 | Name_Buffer (Name_Len + 2) := Source (Scan_Ptr + 1); | |
1891 | Accumulate_Checksum (Source (Scan_Ptr + 1)); | |
1892 | ||
1893 | elsif Source (Scan_Ptr + 1) in 'A' .. 'Z' then | |
1894 | Name_Buffer (Name_Len + 2) := | |
1895 | Character'Val (Character'Pos (Source (Scan_Ptr + 1)) + 32); | |
1896 | Accumulate_Checksum (Name_Buffer (Name_Len + 2)); | |
1897 | ||
1898 | else | |
1899 | Scan_Ptr := Scan_Ptr + 1; | |
1900 | Name_Len := Name_Len + 1; | |
1901 | exit; | |
1902 | end if; | |
1903 | ||
1904 | if Source (Scan_Ptr + 2) in 'a' .. 'z' | |
1905 | or else Source (Scan_Ptr + 2) in '0' .. '9' | |
1906 | then | |
1907 | Name_Buffer (Name_Len + 3) := Source (Scan_Ptr + 2); | |
1908 | Accumulate_Checksum (Source (Scan_Ptr + 2)); | |
1909 | ||
1910 | elsif Source (Scan_Ptr + 2) in 'A' .. 'Z' then | |
1911 | Name_Buffer (Name_Len + 3) := | |
1912 | Character'Val (Character'Pos (Source (Scan_Ptr + 2)) + 32); | |
1913 | Accumulate_Checksum (Name_Buffer (Name_Len + 3)); | |
1914 | else | |
1915 | Scan_Ptr := Scan_Ptr + 2; | |
1916 | Name_Len := Name_Len + 2; | |
1917 | exit; | |
1918 | end if; | |
1919 | ||
1920 | if Source (Scan_Ptr + 3) in 'a' .. 'z' | |
1921 | or else Source (Scan_Ptr + 3) in '0' .. '9' | |
1922 | then | |
1923 | Name_Buffer (Name_Len + 4) := Source (Scan_Ptr + 3); | |
1924 | Accumulate_Checksum (Source (Scan_Ptr + 3)); | |
1925 | ||
1926 | elsif Source (Scan_Ptr + 3) in 'A' .. 'Z' then | |
1927 | Name_Buffer (Name_Len + 4) := | |
1928 | Character'Val (Character'Pos (Source (Scan_Ptr + 3)) + 32); | |
1929 | Accumulate_Checksum (Name_Buffer (Name_Len + 4)); | |
1930 | ||
1931 | else | |
1932 | Scan_Ptr := Scan_Ptr + 3; | |
1933 | Name_Len := Name_Len + 3; | |
1934 | exit; | |
1935 | end if; | |
1936 | ||
1937 | Scan_Ptr := Scan_Ptr + 4; | |
1938 | Name_Len := Name_Len + 4; | |
1939 | end loop; | |
1940 | ||
1941 | -- If we fall through, then we have encountered either an underline | |
1942 | -- character, or an extended identifier character (i.e. one from the | |
1943 | -- upper half), or a wide character, or an identifier terminator. | |
1944 | -- The initial test speeds us up in the most common case where we | |
1945 | -- have an identifier terminator. Note that ESC is an identifier | |
1946 | -- character only if a wide character encoding method that uses | |
1947 | -- ESC encoding is active, so if we find an ESC character we know | |
1948 | -- that we have a wide character. | |
1949 | ||
1950 | if Identifier_Char (Source (Scan_Ptr)) then | |
1951 | ||
1952 | -- Case of underline | |
1953 | ||
1954 | if Source (Scan_Ptr) = '_' then | |
1955 | Accumulate_Checksum ('_'); | |
1956 | ||
1957 | -- Check error case of identifier ending with underscore | |
1958 | -- In this case we ignore the underscore and do not store it. | |
1959 | ||
1960 | if not Identifier_Char (Source (Scan_Ptr + 1)) then | |
1961 | Error_Msg_S ("identifier cannot end with underline"); | |
1962 | Scan_Ptr := Scan_Ptr + 1; | |
1963 | ||
1964 | -- Check error case of two underscores. In this case we do | |
1965 | -- not store the first underscore (we will store the second) | |
1966 | ||
1967 | elsif Source (Scan_Ptr + 1) = '_' then | |
1968 | Error_No_Double_Underline; | |
1969 | ||
1970 | -- Normal case of legal underscore | |
1971 | ||
1972 | else | |
1973 | Name_Len := Name_Len + 1; | |
1974 | Name_Buffer (Name_Len) := '_'; | |
1975 | end if; | |
1976 | ||
1977 | Scan_Ptr := Scan_Ptr + 1; | |
1978 | goto Scan_Identifier; | |
1979 | ||
1980 | -- Upper half character | |
1981 | ||
1982 | elsif Source (Scan_Ptr) in Upper_Half_Character | |
1983 | and then not Upper_Half_Encoding | |
1984 | then | |
1985 | Accumulate_Checksum (Source (Scan_Ptr)); | |
1986 | Store_Encoded_Character | |
1987 | (Get_Char_Code (Fold_Lower (Source (Scan_Ptr)))); | |
1988 | Scan_Ptr := Scan_Ptr + 1; | |
1989 | goto Scan_Identifier; | |
1990 | ||
1991 | -- Left bracket not followed by a quote terminates an identifier. | |
1992 | -- This is an error, but we don't want to give a junk error msg | |
1993 | -- about wide characters in this case! | |
1994 | ||
1995 | elsif Source (Scan_Ptr) = '[' | |
1996 | and then Source (Scan_Ptr + 1) /= '"' | |
1997 | then | |
1998 | null; | |
1999 | ||
2000 | -- We know we have a wide character encoding here (the current | |
2001 | -- character is either ESC, left bracket, or an upper half | |
2002 | -- character depending on the encoding method). | |
2003 | ||
2004 | else | |
2005 | -- Scan out the wide character and insert the appropriate | |
2006 | -- encoding into the name table entry for the identifier. | |
2007 | ||
2008 | declare | |
2009 | Sptr : constant Source_Ptr := Scan_Ptr; | |
2010 | Code : Char_Code; | |
2011 | Err : Boolean; | |
2012 | Chr : Character; | |
2013 | ||
2014 | begin | |
2015 | Scan_Wide (Source, Scan_Ptr, Code, Err); | |
2016 | ||
2017 | -- If error, signal error | |
2018 | ||
2019 | if Err then | |
2020 | Error_Illegal_Wide_Character; | |
2021 | ||
2022 | -- If the character scanned is a normal identifier | |
2023 | -- character, then we treat it that way. | |
2024 | ||
2025 | elsif In_Character_Range (Code) | |
2026 | and then Identifier_Char (Get_Character (Code)) | |
2027 | then | |
2028 | Chr := Get_Character (Code); | |
2029 | Accumulate_Checksum (Chr); | |
2030 | Store_Encoded_Character | |
2031 | (Get_Char_Code (Fold_Lower (Chr))); | |
2032 | ||
2033 | -- Character is not normal identifier character, store | |
2034 | -- it in encoded form. | |
2035 | ||
2036 | else | |
2037 | Accumulate_Checksum (Code); | |
2038 | Store_Encoded_Character (Code); | |
2039 | ||
2040 | -- Make sure we are allowing wide characters in | |
2041 | -- identifiers. Note that we allow wide character | |
2042 | -- notation for an OK identifier character. This | |
2043 | -- in particular allows bracket or other notation | |
2044 | -- to be used for upper half letters. | |
2045 | ||
2046 | if Identifier_Character_Set /= 'w' then | |
2047 | Error_Msg | |
2048 | ("wide character not allowed in identifier", Sptr); | |
2049 | end if; | |
2050 | end if; | |
2051 | end; | |
2052 | ||
2053 | goto Scan_Identifier; | |
2054 | end if; | |
2055 | end if; | |
2056 | ||
2057 | -- Scan of identifier is complete. The identifier is stored in | |
2058 | -- Name_Buffer, and Scan_Ptr points past the last character. | |
2059 | ||
2060 | Token_Name := Name_Find; | |
2061 | ||
2062 | -- Here is where we check if it was a keyword | |
2063 | ||
2064 | if Get_Name_Table_Byte (Token_Name) /= 0 | |
0ab80019 AC |
2065 | and then (Ada_Version >= Ada_95 |
2066 | or else Token_Name not in Ada_95_Reserved_Words) | |
fbf5a39b AC |
2067 | then |
2068 | Token := Token_Type'Val (Get_Name_Table_Byte (Token_Name)); | |
2069 | ||
2070 | -- Deal with possible style check for non-lower case keyword, | |
2071 | -- but we don't treat ACCESS, DELTA, DIGITS, RANGE as keywords | |
2072 | -- for this purpose if they appear as attribute designators. | |
2073 | -- Actually we only check the first character for speed. | |
2074 | ||
2075 | if Style_Check | |
2076 | and then Source (Token_Ptr) <= 'Z' | |
2077 | and then (Prev_Token /= Tok_Apostrophe | |
2078 | or else | |
2079 | (Token /= Tok_Access | |
2080 | and then Token /= Tok_Delta | |
2081 | and then Token /= Tok_Digits | |
2082 | and then Token /= Tok_Range)) | |
2083 | then | |
2084 | Style.Non_Lower_Case_Keyword; | |
2085 | end if; | |
2086 | ||
2087 | -- We must reset Token_Name since this is not an identifier | |
2088 | -- and if we leave Token_Name set, the parser gets confused | |
2089 | -- because it thinks it is dealing with an identifier instead | |
2090 | -- of the corresponding keyword. | |
2091 | ||
2092 | Token_Name := No_Name; | |
6b6fcd3e | 2093 | Accumulate_Token_Checksum; |
fbf5a39b AC |
2094 | return; |
2095 | ||
2096 | -- It is an identifier after all | |
2097 | ||
2098 | else | |
2099 | Token := Tok_Identifier; | |
6b6fcd3e | 2100 | Accumulate_Token_Checksum; |
fbf5a39b AC |
2101 | Post_Scan; |
2102 | return; | |
2103 | end if; | |
2104 | end Scan; | |
6b6fcd3e | 2105 | |
c45b6ae0 AC |
2106 | -------------------------- |
2107 | -- Set_Comment_As_Token -- | |
2108 | -------------------------- | |
2109 | ||
2110 | procedure Set_Comment_As_Token (Value : Boolean) is | |
2111 | begin | |
2112 | Comment_Is_Token := Value; | |
2113 | end Set_Comment_As_Token; | |
fbf5a39b AC |
2114 | |
2115 | ------------------------------ | |
2116 | -- Set_End_Of_Line_As_Token -- | |
2117 | ------------------------------ | |
2118 | ||
2119 | procedure Set_End_Of_Line_As_Token (Value : Boolean) is | |
2120 | begin | |
2121 | End_Of_Line_Is_Token := Value; | |
2122 | end Set_End_Of_Line_As_Token; | |
2123 | ||
2124 | --------------------------- | |
2125 | -- Set_Special_Character -- | |
2126 | --------------------------- | |
2127 | ||
2128 | procedure Set_Special_Character (C : Character) is | |
2129 | begin | |
2130 | case C is | |
2131 | when '#' | '$' | '_' | '?' | '@' | '`' | '\' | '^' | '~' => | |
2132 | Special_Characters (C) := True; | |
2133 | ||
2134 | when others => | |
2135 | null; | |
2136 | end case; | |
2137 | end Set_Special_Character; | |
2138 | ||
2139 | ---------------------- | |
2140 | -- Set_Start_Column -- | |
2141 | ---------------------- | |
2142 | ||
2143 | -- Note: it seems at first glance a little expensive to compute this value | |
2144 | -- for every source line (since it is certainly not used for all source | |
2145 | -- lines). On the other hand, it doesn't take much more work to skip past | |
2146 | -- the initial white space on the line counting the columns than it would | |
2147 | -- to scan past the white space using the standard scanning circuits. | |
2148 | ||
2149 | function Set_Start_Column return Column_Number is | |
2150 | Start_Column : Column_Number := 0; | |
2151 | ||
2152 | begin | |
2153 | -- Outer loop scans past horizontal tab characters | |
2154 | ||
2155 | Tabs_Loop : loop | |
2156 | ||
2157 | -- Inner loop scans past blanks as fast as possible, bumping Scan_Ptr | |
2158 | -- past the blanks and adjusting Start_Column to account for them. | |
2159 | ||
2160 | Blanks_Loop : loop | |
2161 | if Source (Scan_Ptr) = ' ' then | |
2162 | if Source (Scan_Ptr + 1) = ' ' then | |
2163 | if Source (Scan_Ptr + 2) = ' ' then | |
2164 | if Source (Scan_Ptr + 3) = ' ' then | |
2165 | if Source (Scan_Ptr + 4) = ' ' then | |
2166 | if Source (Scan_Ptr + 5) = ' ' then | |
2167 | if Source (Scan_Ptr + 6) = ' ' then | |
2168 | Scan_Ptr := Scan_Ptr + 7; | |
2169 | Start_Column := Start_Column + 7; | |
2170 | else | |
2171 | Scan_Ptr := Scan_Ptr + 6; | |
2172 | Start_Column := Start_Column + 6; | |
2173 | exit Blanks_Loop; | |
2174 | end if; | |
2175 | else | |
2176 | Scan_Ptr := Scan_Ptr + 5; | |
2177 | Start_Column := Start_Column + 5; | |
2178 | exit Blanks_Loop; | |
2179 | end if; | |
2180 | else | |
2181 | Scan_Ptr := Scan_Ptr + 4; | |
2182 | Start_Column := Start_Column + 4; | |
2183 | exit Blanks_Loop; | |
2184 | end if; | |
2185 | else | |
2186 | Scan_Ptr := Scan_Ptr + 3; | |
2187 | Start_Column := Start_Column + 3; | |
2188 | exit Blanks_Loop; | |
2189 | end if; | |
2190 | else | |
2191 | Scan_Ptr := Scan_Ptr + 2; | |
2192 | Start_Column := Start_Column + 2; | |
2193 | exit Blanks_Loop; | |
2194 | end if; | |
2195 | else | |
2196 | Scan_Ptr := Scan_Ptr + 1; | |
2197 | Start_Column := Start_Column + 1; | |
2198 | exit Blanks_Loop; | |
2199 | end if; | |
2200 | else | |
2201 | exit Blanks_Loop; | |
2202 | end if; | |
2203 | end loop Blanks_Loop; | |
2204 | ||
2205 | -- Outer loop keeps going only if a horizontal tab follows | |
2206 | ||
2207 | if Source (Scan_Ptr) = HT then | |
2208 | if Style_Check then Style.Check_HT; end if; | |
2209 | Scan_Ptr := Scan_Ptr + 1; | |
2210 | Start_Column := (Start_Column / 8) * 8 + 8; | |
2211 | else | |
2212 | exit Tabs_Loop; | |
2213 | end if; | |
2214 | ||
2215 | end loop Tabs_Loop; | |
2216 | ||
2217 | return Start_Column; | |
2218 | end Set_Start_Column; | |
2219 | ||
2220 | end Scng; |