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Merge from mainline (160224:163495).
[official-gcc/graphite-test-results.git] / gcc / ada / s-regpat.adb
blob1c0cf746a531e45bd5e8473b6c84d64d8944e309
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT LIBRARY COMPONENTS --
4 -- --
5 -- G N A T . R E G P A T --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1986 by University of Toronto. --
10 -- Copyright (C) 1999-2010, AdaCore --
11 -- --
12 -- GNAT is free software; you can redistribute it and/or modify it under --
13 -- terms of the GNU General Public License as published by the Free Soft- --
14 -- ware Foundation; either version 2, or (at your option) any later ver- --
15 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
16 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
17 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
18 -- for more details. You should have received a copy of the GNU General --
19 -- Public License distributed with GNAT; see file COPYING. If not, write --
20 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
21 -- Boston, MA 02110-1301, USA. --
22 -- --
23 -- As a special exception, if other files instantiate generics from this --
24 -- unit, or you link this unit with other files to produce an executable, --
25 -- this unit does not by itself cause the resulting executable to be --
26 -- covered by the GNU General Public License. This exception does not --
27 -- however invalidate any other reasons why the executable file might be --
28 -- covered by the GNU Public License. --
29 -- --
30 -- GNAT was originally developed by the GNAT team at New York University. --
31 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 -- --
33 ------------------------------------------------------------------------------
34
35 -- This is an altered Ada 95 version of the original V8 style regular
36 -- expression library written in C by Henry Spencer. Apart from the
37 -- translation to Ada, the interface has been considerably changed to
38 -- use the Ada String type instead of C-style nul-terminated strings.
39
40 -- Beware that some of this code is subtly aware of the way operator
41 -- precedence is structured in regular expressions. Serious changes in
42 -- regular-expression syntax might require a total rethink.
43
44 with System.IO; use System.IO;
45 with Ada.Characters.Handling; use Ada.Characters.Handling;
46 with Ada.Unchecked_Conversion;
47
48 package body System.Regpat is
49
50 Debug : constant Boolean := False;
51 -- Set to True to activate debug traces. This is normally set to constant
52 -- False to simply delete all the trace code. It is to be edited to True
53 -- for internal debugging of the package.
54
55 ----------------------------
56 -- Implementation details --
57 ----------------------------
58
59 -- This is essentially a linear encoding of a nondeterministic
60 -- finite-state machine, also known as syntax charts or
61 -- "railroad normal form" in parsing technology.
62
63 -- Each node is an opcode plus a "next" pointer, possibly plus an
64 -- operand. "Next" pointers of all nodes except BRANCH implement
65 -- concatenation; a "next" pointer with a BRANCH on both ends of it
66 -- is connecting two alternatives.
67
68 -- The operand of some types of node is a literal string; for others,
69 -- it is a node leading into a sub-FSM. In particular, the operand of
70 -- a BRANCH node is the first node of the branch.
71 -- (NB this is *not* a tree structure: the tail of the branch connects
72 -- to the thing following the set of BRANCHes).
73
74 -- You can see the exact byte-compiled version by using the Dump
75 -- subprogram. However, here are a few examples:
76
77 -- (a|b): 1 : BRANCH (next at 9)
78 -- 4 : EXACT (next at 17) operand=a
79 -- 9 : BRANCH (next at 17)
80 -- 12 : EXACT (next at 17) operand=b
81 -- 17 : EOP (next at 0)
82 --
83 -- (ab)*: 1 : CURLYX (next at 25) { 0, 32767}
84 -- 8 : OPEN 1 (next at 12)
85 -- 12 : EXACT (next at 18) operand=ab
86 -- 18 : CLOSE 1 (next at 22)
87 -- 22 : WHILEM (next at 0)
88 -- 25 : NOTHING (next at 28)
89 -- 28 : EOP (next at 0)
90
91 -- The opcodes are:
92
93 type Opcode is
94
95 -- Name Operand? Meaning
96
97 (EOP, -- no End of program
98 MINMOD, -- no Next operator is not greedy
99
100 -- Classes of characters
101
102 ANY, -- no Match any one character except newline
103 SANY, -- no Match any character, including new line
104 ANYOF, -- class Match any character in this class
105 EXACT, -- str Match this string exactly
106 EXACTF, -- str Match this string (case-folding is one)
107 NOTHING, -- no Match empty string
108 SPACE, -- no Match any whitespace character
109 NSPACE, -- no Match any non-whitespace character
110 DIGIT, -- no Match any numeric character
111 NDIGIT, -- no Match any non-numeric character
112 ALNUM, -- no Match any alphanumeric character
113 NALNUM, -- no Match any non-alphanumeric character
114
115 -- Branches
116
117 BRANCH, -- node Match this alternative, or the next
118
119 -- Simple loops (when the following node is one character in length)
120
121 STAR, -- node Match this simple thing 0 or more times
122 PLUS, -- node Match this simple thing 1 or more times
123 CURLY, -- 2num node Match this simple thing between n and m times.
124
125 -- Complex loops
126
127 CURLYX, -- 2num node Match this complex thing {n,m} times
128 -- The nums are coded on two characters each
129
130 WHILEM, -- no Do curly processing and see if rest matches
131
132 -- Matches after or before a word
133
134 BOL, -- no Match "" at beginning of line
135 MBOL, -- no Same, assuming multiline (match after \n)
136 SBOL, -- no Same, assuming single line (don't match at \n)
137 EOL, -- no Match "" at end of line
138 MEOL, -- no Same, assuming multiline (match before \n)
139 SEOL, -- no Same, assuming single line (don't match at \n)
140
141 BOUND, -- no Match "" at any word boundary
142 NBOUND, -- no Match "" at any word non-boundary
143
144 -- Parenthesis groups handling
145
146 REFF, -- num Match some already matched string, folded
147 OPEN, -- num Mark this point in input as start of #n
148 CLOSE); -- num Analogous to OPEN
149
150 for Opcode'Size use 8;
151
152 -- Opcode notes:
153
154 -- BRANCH
155 -- The set of branches constituting a single choice are hooked
156 -- together with their "next" pointers, since precedence prevents
157 -- anything being concatenated to any individual branch. The
158 -- "next" pointer of the last BRANCH in a choice points to the
159 -- thing following the whole choice. This is also where the
160 -- final "next" pointer of each individual branch points; each
161 -- branch starts with the operand node of a BRANCH node.
162
163 -- STAR,PLUS
164 -- '?', and complex '*' and '+', are implemented with CURLYX.
165 -- branches. Simple cases (one character per match) are implemented with
166 -- STAR and PLUS for speed and to minimize recursive plunges.
167
168 -- OPEN,CLOSE
169 -- ...are numbered at compile time.
170
171 -- EXACT, EXACTF
172 -- There are in fact two arguments, the first one is the length (minus
173 -- one of the string argument), coded on one character, the second
174 -- argument is the string itself, coded on length + 1 characters.
175
176 -- A node is one char of opcode followed by two chars of "next" pointer.
177 -- "Next" pointers are stored as two 8-bit pieces, high order first. The
178 -- value is a positive offset from the opcode of the node containing it.
179 -- An operand, if any, simply follows the node. (Note that much of the
180 -- code generation knows about this implicit relationship.)
181
182 -- Using two bytes for the "next" pointer is vast overkill for most
183 -- things, but allows patterns to get big without disasters.
184
185 Next_Pointer_Bytes : constant := 3;
186 -- Points after the "next pointer" data. An instruction is therefore:
187 -- 1 byte: instruction opcode
188 -- 2 bytes: pointer to next instruction
189 -- * bytes: optional data for the instruction
190
191 -----------------------
192 -- Character classes --
193 -----------------------
194 -- This is the implementation for character classes ([...]) in the
195 -- syntax for regular expressions. Each character (0..256) has an
196 -- entry into the table. This makes for a very fast matching
197 -- algorithm.
198
199 type Class_Byte is mod 256;
200 type Character_Class is array (Class_Byte range 0 .. 31) of Class_Byte;
201
202 type Bit_Conversion_Array is array (Class_Byte range 0 .. 7) of Class_Byte;
203 Bit_Conversion : constant Bit_Conversion_Array :=
204 (1, 2, 4, 8, 16, 32, 64, 128);
205
206 type Std_Class is (ANYOF_NONE,
207 ANYOF_ALNUM, -- Alphanumeric class [a-zA-Z0-9]
208 ANYOF_NALNUM,
209 ANYOF_SPACE, -- Space class [ \t\n\r\f]
210 ANYOF_NSPACE,
211 ANYOF_DIGIT, -- Digit class [0-9]
212 ANYOF_NDIGIT,
213 ANYOF_ALNUMC, -- Alphanumeric class [a-zA-Z0-9]
214 ANYOF_NALNUMC,
215 ANYOF_ALPHA, -- Alpha class [a-zA-Z]
216 ANYOF_NALPHA,
217 ANYOF_ASCII, -- Ascii class (7 bits) 0..127
218 ANYOF_NASCII,
219 ANYOF_CNTRL, -- Control class
220 ANYOF_NCNTRL,
221 ANYOF_GRAPH, -- Graphic class
222 ANYOF_NGRAPH,
223 ANYOF_LOWER, -- Lower case class [a-z]
224 ANYOF_NLOWER,
225 ANYOF_PRINT, -- printable class
226 ANYOF_NPRINT,
227 ANYOF_PUNCT, --
228 ANYOF_NPUNCT,
229 ANYOF_UPPER, -- Upper case class [A-Z]
230 ANYOF_NUPPER,
231 ANYOF_XDIGIT, -- Hexadecimal digit
232 ANYOF_NXDIGIT
233 );
234
235 procedure Set_In_Class
236 (Bitmap : in out Character_Class;
237 C : Character);
238 -- Set the entry to True for C in the class Bitmap
239
240 function Get_From_Class
241 (Bitmap : Character_Class;
242 C : Character) return Boolean;
243 -- Return True if the entry is set for C in the class Bitmap
244
245 procedure Reset_Class (Bitmap : out Character_Class);
246 -- Clear all the entries in the class Bitmap
247
248 pragma Inline (Set_In_Class);
249 pragma Inline (Get_From_Class);
250 pragma Inline (Reset_Class);
251
252 -----------------------
253 -- Local Subprograms --
254 -----------------------
255
256 function "=" (Left : Character; Right : Opcode) return Boolean;
257
258 function Is_Alnum (C : Character) return Boolean;
259 -- Return True if C is an alphanum character or an underscore ('_')
260
261 function Is_White_Space (C : Character) return Boolean;
262 -- Return True if C is a whitespace character
263
264 function Is_Printable (C : Character) return Boolean;
265 -- Return True if C is a printable character
266
267 function Operand (P : Pointer) return Pointer;
268 -- Return a pointer to the first operand of the node at P
269
270 function String_Length
271 (Program : Program_Data;
272 P : Pointer) return Program_Size;
273 -- Return the length of the string argument of the node at P
274
275 function String_Operand (P : Pointer) return Pointer;
276 -- Return a pointer to the string argument of the node at P
277
278 procedure Bitmap_Operand
279 (Program : Program_Data;
280 P : Pointer;
281 Op : out Character_Class);
282 -- Return a pointer to the string argument of the node at P
283
284 function Get_Next
285 (Program : Program_Data;
286 IP : Pointer) return Pointer;
287 -- Dig the next instruction pointer out of a node
288
289 procedure Optimize (Self : in out Pattern_Matcher);
290 -- Optimize a Pattern_Matcher by noting certain special cases
291
292 function Read_Natural
293 (Program : Program_Data;
294 IP : Pointer) return Natural;
295 -- Return the 2-byte natural coded at position IP
296
297 -- All of the subprograms above are tiny and should be inlined
298
299 pragma Inline ("=");
300 pragma Inline (Is_Alnum);
301 pragma Inline (Is_White_Space);
302 pragma Inline (Get_Next);
303 pragma Inline (Operand);
304 pragma Inline (Read_Natural);
305 pragma Inline (String_Length);
306 pragma Inline (String_Operand);
307
308 type Expression_Flags is record
309 Has_Width, -- Known never to match null string
310 Simple, -- Simple enough to be STAR/PLUS operand
311 SP_Start : Boolean; -- Starts with * or +
312 end record;
313
314 Worst_Expression : constant Expression_Flags := (others => False);
315 -- Worst case
316
317 procedure Dump_Until
318 (Program : Program_Data;
319 Index : in out Pointer;
320 Till : Pointer;
321 Indent : Natural;
322 Do_Print : Boolean := True);
323 -- Dump the program until the node Till (not included) is met. Every line
324 -- is indented with Index spaces at the beginning Dumps till the end if
325 -- Till is 0.
326
327 procedure Dump_Operation
328 (Program : Program_Data;
329 Index : Pointer;
330 Indent : Natural);
331 -- Same as above, but only dumps a single operation, and compute its
332 -- indentation from the program.
333
334 ---------
335 -- "=" --
336 ---------
337
338 function "=" (Left : Character; Right : Opcode) return Boolean is
339 begin
340 return Character'Pos (Left) = Opcode'Pos (Right);
341 end "=";
342
343 --------------------
344 -- Bitmap_Operand --
345 --------------------
346
347 procedure Bitmap_Operand
348 (Program : Program_Data;
349 P : Pointer;
350 Op : out Character_Class)
351 is
352 function Convert is new Ada.Unchecked_Conversion
353 (Program_Data, Character_Class);
354
355 begin
356 Op (0 .. 31) := Convert (Program (P + Next_Pointer_Bytes .. P + 34));
357 end Bitmap_Operand;
358
359 -------------
360 -- Compile --
361 -------------
362
363 procedure Compile
364 (Matcher : out Pattern_Matcher;
365 Expression : String;
366 Final_Code_Size : out Program_Size;
367 Flags : Regexp_Flags := No_Flags)
368 is
369 -- We can't allocate space until we know how big the compiled form
370 -- will be, but we can't compile it (and thus know how big it is)
371 -- until we've got a place to put the code. So we cheat: we compile
372 -- it twice, once with code generation turned off and size counting
373 -- turned on, and once "for real".
374
375 -- This also means that we don't allocate space until we are sure
376 -- that the thing really will compile successfully, and we never
377 -- have to move the code and thus invalidate pointers into it.
378
379 -- Beware that the optimization-preparation code in here knows
380 -- about some of the structure of the compiled regexp.
381
382 PM : Pattern_Matcher renames Matcher;
383 Program : Program_Data renames PM.Program;
384
385 Emit_Ptr : Pointer := Program_First;
386
387 Parse_Pos : Natural := Expression'First; -- Input-scan pointer
388 Parse_End : constant Natural := Expression'Last;
389
390 ----------------------------
391 -- Subprograms for Create --
392 ----------------------------
393
394 procedure Emit (B : Character);
395 -- Output the Character B to the Program. If code-generation is
396 -- disabled, simply increments the program counter.
397
398 function Emit_Node (Op : Opcode) return Pointer;
399 -- If code-generation is enabled, Emit_Node outputs the
400 -- opcode Op and reserves space for a pointer to the next node.
401 -- Return value is the location of new opcode, i.e. old Emit_Ptr.
402
403 procedure Emit_Natural (IP : Pointer; N : Natural);
404 -- Split N on two characters at position IP
405
406 procedure Emit_Class (Bitmap : Character_Class);
407 -- Emits a character class
408
409 procedure Case_Emit (C : Character);
410 -- Emit C, after converting is to lower-case if the regular
411 -- expression is case insensitive.
412
413 procedure Parse
414 (Parenthesized : Boolean;
415 Flags : out Expression_Flags;
416 IP : out Pointer);
417 -- Parse regular expression, i.e. main body or parenthesized thing
418 -- Caller must absorb opening parenthesis.
419
420 procedure Parse_Branch
421 (Flags : out Expression_Flags;
422 First : Boolean;
423 IP : out Pointer);
424 -- Implements the concatenation operator and handles '|'
425 -- First should be true if this is the first item of the alternative.
426
427 procedure Parse_Piece
428 (Expr_Flags : out Expression_Flags;
429 IP : out Pointer);
430 -- Parse something followed by possible [*+?]
431
432 procedure Parse_Atom
433 (Expr_Flags : out Expression_Flags;
434 IP : out Pointer);
435 -- Parse_Atom is the lowest level parse procedure.
436 --
437 -- Optimization: Gobbles an entire sequence of ordinary characters so
438 -- that it can turn them into a single node, which is smaller to store
439 -- and faster to run. Backslashed characters are exceptions, each
440 -- becoming a separate node; the code is simpler that way and it's
441 -- not worth fixing.
442
443 procedure Insert_Operator
444 (Op : Opcode;
445 Operand : Pointer;
446 Greedy : Boolean := True);
447 -- Insert_Operator inserts an operator in front of an already-emitted
448 -- operand and relocates the operand. This applies to PLUS and STAR.
449 -- If Minmod is True, then the operator is non-greedy.
450
451 function Insert_Operator_Before
452 (Op : Opcode;
453 Operand : Pointer;
454 Greedy : Boolean;
455 Opsize : Pointer) return Pointer;
456 -- Insert an operator before Operand (and move the latter forward in the
457 -- program). Opsize is the size needed to represent the operator. This
458 -- returns the position at which the operator was inserted, and moves
459 -- Emit_Ptr after the new position of the operand.
460
461 procedure Insert_Curly_Operator
462 (Op : Opcode;
463 Min : Natural;
464 Max : Natural;
465 Operand : Pointer;
466 Greedy : Boolean := True);
467 -- Insert an operator for CURLY ({Min}, {Min,} or {Min,Max}).
468 -- If Minmod is True, then the operator is non-greedy.
469
470 procedure Link_Tail (P, Val : Pointer);
471 -- Link_Tail sets the next-pointer at the end of a node chain
472
473 procedure Link_Operand_Tail (P, Val : Pointer);
474 -- Link_Tail on operand of first argument; noop if operand-less
475
476 procedure Fail (M : String);
477 pragma No_Return (Fail);
478 -- Fail with a diagnostic message, if possible
479
480 function Is_Curly_Operator (IP : Natural) return Boolean;
481 -- Return True if IP is looking at a '{' that is the beginning
482 -- of a curly operator, i.e. it matches {\d+,?\d*}
483
484 function Is_Mult (IP : Natural) return Boolean;
485 -- Return True if C is a regexp multiplier: '+', '*' or '?'
486
487 procedure Get_Curly_Arguments
488 (IP : Natural;
489 Min : out Natural;
490 Max : out Natural;
491 Greedy : out Boolean);
492 -- Parse the argument list for a curly operator.
493 -- It is assumed that IP is indeed pointing at a valid operator.
494 -- So what is IP and how come IP is not referenced in the body ???
495
496 procedure Parse_Character_Class (IP : out Pointer);
497 -- Parse a character class.
498 -- The calling subprogram should consume the opening '[' before.
499
500 procedure Parse_Literal
501 (Expr_Flags : out Expression_Flags;
502 IP : out Pointer);
503 -- Parse_Literal encodes a string of characters to be matched exactly
504
505 function Parse_Posix_Character_Class return Std_Class;
506 -- Parse a posix character class, like [:alpha:] or [:^alpha:].
507 -- The caller is supposed to absorb the opening [.
508
509 pragma Inline (Is_Mult);
510 pragma Inline (Emit_Natural);
511 pragma Inline (Parse_Character_Class); -- since used only once
512
513 ---------------
514 -- Case_Emit --
515 ---------------
516
517 procedure Case_Emit (C : Character) is
518 begin
519 if (Flags and Case_Insensitive) /= 0 then
520 Emit (To_Lower (C));
521
522 else
523 -- Dump current character
524
525 Emit (C);
526 end if;
527 end Case_Emit;
528
529 ----------
530 -- Emit --
531 ----------
532
533 procedure Emit (B : Character) is
534 begin
535 if Emit_Ptr <= PM.Size then
536 Program (Emit_Ptr) := B;
537 end if;
538
539 Emit_Ptr := Emit_Ptr + 1;
540 end Emit;
541
542 ----------------
543 -- Emit_Class --
544 ----------------
545
546 procedure Emit_Class (Bitmap : Character_Class) is
547 subtype Program31 is Program_Data (0 .. 31);
548
549 function Convert is new Ada.Unchecked_Conversion
550 (Character_Class, Program31);
551
552 begin
553 -- What is the mysterious constant 31 here??? Can't it be expressed
554 -- symbolically (size of integer - 1 or some such???). In any case
555 -- it should be declared as a constant (and referenced presumably
556 -- as this constant + 1 below.
557
558 if Emit_Ptr + 31 <= PM.Size then
559 Program (Emit_Ptr .. Emit_Ptr + 31) := Convert (Bitmap);
560 end if;
561
562 Emit_Ptr := Emit_Ptr + 32;
563 end Emit_Class;
564
565 ------------------
566 -- Emit_Natural --
567 ------------------
568
569 procedure Emit_Natural (IP : Pointer; N : Natural) is
570 begin
571 if IP + 1 <= PM.Size then
572 Program (IP + 1) := Character'Val (N / 256);
573 Program (IP) := Character'Val (N mod 256);
574 end if;
575 end Emit_Natural;
576
577 ---------------
578 -- Emit_Node --
579 ---------------
580
581 function Emit_Node (Op : Opcode) return Pointer is
582 Result : constant Pointer := Emit_Ptr;
583
584 begin
585 if Emit_Ptr + 2 <= PM.Size then
586 Program (Emit_Ptr) := Character'Val (Opcode'Pos (Op));
587 Program (Emit_Ptr + 1) := ASCII.NUL;
588 Program (Emit_Ptr + 2) := ASCII.NUL;
589 end if;
590
591 Emit_Ptr := Emit_Ptr + Next_Pointer_Bytes;
592 return Result;
593 end Emit_Node;
594
595 ----------
596 -- Fail --
597 ----------
598
599 procedure Fail (M : String) is
600 begin
601 raise Expression_Error with M;
602 end Fail;
603
604 -------------------------
605 -- Get_Curly_Arguments --
606 -------------------------
607
608 procedure Get_Curly_Arguments
609 (IP : Natural;
610 Min : out Natural;
611 Max : out Natural;
612 Greedy : out Boolean)
613 is
614 pragma Unreferenced (IP);
615
616 Save_Pos : Natural := Parse_Pos + 1;
617
618 begin
619 Min := 0;
620 Max := Max_Curly_Repeat;
621
622 while Expression (Parse_Pos) /= '}'
623 and then Expression (Parse_Pos) /= ','
624 loop
625 Parse_Pos := Parse_Pos + 1;
626 end loop;
627
628 Min := Natural'Value (Expression (Save_Pos .. Parse_Pos - 1));
629
630 if Expression (Parse_Pos) = ',' then
631 Save_Pos := Parse_Pos + 1;
632 while Expression (Parse_Pos) /= '}' loop
633 Parse_Pos := Parse_Pos + 1;
634 end loop;
635
636 if Save_Pos /= Parse_Pos then
637 Max := Natural'Value (Expression (Save_Pos .. Parse_Pos - 1));
638 end if;
639
640 else
641 Max := Min;
642 end if;
643
644 if Parse_Pos < Expression'Last
645 and then Expression (Parse_Pos + 1) = '?'
646 then
647 Greedy := False;
648 Parse_Pos := Parse_Pos + 1;
649
650 else
651 Greedy := True;
652 end if;
653 end Get_Curly_Arguments;
654
655 ---------------------------
656 -- Insert_Curly_Operator --
657 ---------------------------
658
659 procedure Insert_Curly_Operator
660 (Op : Opcode;
661 Min : Natural;
662 Max : Natural;
663 Operand : Pointer;
664 Greedy : Boolean := True)
665 is
666 Old : Pointer;
667 begin
668 Old := Insert_Operator_Before (Op, Operand, Greedy, Opsize => 7);
669 Emit_Natural (Old + Next_Pointer_Bytes, Min);
670 Emit_Natural (Old + Next_Pointer_Bytes + 2, Max);
671 end Insert_Curly_Operator;
672
673 ----------------------------
674 -- Insert_Operator_Before --
675 ----------------------------
676
677 function Insert_Operator_Before
678 (Op : Opcode;
679 Operand : Pointer;
680 Greedy : Boolean;
681 Opsize : Pointer) return Pointer
682 is
683 Dest : constant Pointer := Emit_Ptr;
684 Old : Pointer;
685 Size : Pointer := Opsize;
686
687 begin
688 -- If not greedy, we have to emit another opcode first
689
690 if not Greedy then
691 Size := Size + Next_Pointer_Bytes;
692 end if;
693
694 -- Move the operand in the byte-compilation, so that we can insert
695 -- the operator before it.
696
697 if Emit_Ptr + Size <= PM.Size then
698 Program (Operand + Size .. Emit_Ptr + Size) :=
699 Program (Operand .. Emit_Ptr);
700 end if;
701
702 -- Insert the operator at the position previously occupied by the
703 -- operand.
704
705 Emit_Ptr := Operand;
706
707 if not Greedy then
708 Old := Emit_Node (MINMOD);
709 Link_Tail (Old, Old + Next_Pointer_Bytes);
710 end if;
711
712 Old := Emit_Node (Op);
713 Emit_Ptr := Dest + Size;
714 return Old;
715 end Insert_Operator_Before;
716
717 ---------------------
718 -- Insert_Operator --
719 ---------------------
720
721 procedure Insert_Operator
722 (Op : Opcode;
723 Operand : Pointer;
724 Greedy : Boolean := True)
725 is
726 Discard : Pointer;
727 pragma Warnings (Off, Discard);
728 begin
729 Discard := Insert_Operator_Before
730 (Op, Operand, Greedy, Opsize => Next_Pointer_Bytes);
731 end Insert_Operator;
732
733 -----------------------
734 -- Is_Curly_Operator --
735 -----------------------
736
737 function Is_Curly_Operator (IP : Natural) return Boolean is
738 Scan : Natural := IP;
739
740 begin
741 if Expression (Scan) /= '{'
742 or else Scan + 2 > Expression'Last
743 or else not Is_Digit (Expression (Scan + 1))
744 then
745 return False;
746 end if;
747
748 Scan := Scan + 1;
749
750 -- The first digit
751
752 loop
753 Scan := Scan + 1;
754
755 if Scan > Expression'Last then
756 return False;
757 end if;
758
759 exit when not Is_Digit (Expression (Scan));
760 end loop;
761
762 if Expression (Scan) = ',' then
763 loop
764 Scan := Scan + 1;
765
766 if Scan > Expression'Last then
767 return False;
768 end if;
769
770 exit when not Is_Digit (Expression (Scan));
771 end loop;
772 end if;
773
774 return Expression (Scan) = '}';
775 end Is_Curly_Operator;
776
777 -------------
778 -- Is_Mult --
779 -------------
780
781 function Is_Mult (IP : Natural) return Boolean is
782 C : constant Character := Expression (IP);
783
784 begin
785 return C = '*'
786 or else C = '+'
787 or else C = '?'
788 or else (C = '{' and then Is_Curly_Operator (IP));
789 end Is_Mult;
790
791 -----------------------
792 -- Link_Operand_Tail --
793 -----------------------
794
795 procedure Link_Operand_Tail (P, Val : Pointer) is
796 begin
797 if P <= PM.Size and then Program (P) = BRANCH then
798 Link_Tail (Operand (P), Val);
799 end if;
800 end Link_Operand_Tail;
801
802 ---------------
803 -- Link_Tail --
804 ---------------
805
806 procedure Link_Tail (P, Val : Pointer) is
807 Scan : Pointer;
808 Temp : Pointer;
809 Offset : Pointer;
810
811 begin
812 -- Find last node (the size of the pattern matcher might be too
813 -- small, so don't try to read past its end).
814
815 Scan := P;
816 while Scan + Next_Pointer_Bytes <= PM.Size loop
817 Temp := Get_Next (Program, Scan);
818 exit when Temp = Scan;
819 Scan := Temp;
820 end loop;
821
822 Offset := Val - Scan;
823
824 Emit_Natural (Scan + 1, Natural (Offset));
825 end Link_Tail;
826
827 -----------
828 -- Parse --
829 -----------
830
831 -- Combining parenthesis handling with the base level of regular
832 -- expression is a trifle forced, but the need to tie the tails of the
833 -- the branches to what follows makes it hard to avoid.
834
835 procedure Parse
836 (Parenthesized : Boolean;
837 Flags : out Expression_Flags;
838 IP : out Pointer)
839 is
840 E : String renames Expression;
841 Br, Br2 : Pointer;
842 Ender : Pointer;
843 Par_No : Natural;
844 New_Flags : Expression_Flags;
845 Have_Branch : Boolean := False;
846
847 begin
848 Flags := (Has_Width => True, others => False); -- Tentatively
849
850 -- Make an OPEN node, if parenthesized
851
852 if Parenthesized then
853 if Matcher.Paren_Count > Max_Paren_Count then
854 Fail ("too many ()");
855 end if;
856
857 Par_No := Matcher.Paren_Count + 1;
858 Matcher.Paren_Count := Matcher.Paren_Count + 1;
859 IP := Emit_Node (OPEN);
860 Emit (Character'Val (Par_No));
861
862 else
863 IP := 0;
864 Par_No := 0;
865 end if;
866
867 -- Pick up the branches, linking them together
868
869 Parse_Branch (New_Flags, True, Br);
870
871 if Br = 0 then
872 IP := 0;
873 return;
874 end if;
875
876 if Parse_Pos <= Parse_End
877 and then E (Parse_Pos) = '|'
878 then
879 Insert_Operator (BRANCH, Br);
880 Have_Branch := True;
881 end if;
882
883 if IP /= 0 then
884 Link_Tail (IP, Br); -- OPEN -> first
885 else
886 IP := Br;
887 end if;
888
889 if not New_Flags.Has_Width then
890 Flags.Has_Width := False;
891 end if;
892
893 Flags.SP_Start := Flags.SP_Start or else New_Flags.SP_Start;
894
895 while Parse_Pos <= Parse_End
896 and then (E (Parse_Pos) = '|')
897 loop
898 Parse_Pos := Parse_Pos + 1;
899 Parse_Branch (New_Flags, False, Br);
900
901 if Br = 0 then
902 IP := 0;
903 return;
904 end if;
905
906 Link_Tail (IP, Br); -- BRANCH -> BRANCH
907
908 if not New_Flags.Has_Width then
909 Flags.Has_Width := False;
910 end if;
911
912 Flags.SP_Start := Flags.SP_Start or else New_Flags.SP_Start;
913 end loop;
914
915 -- Make a closing node, and hook it on the end
916
917 if Parenthesized then
918 Ender := Emit_Node (CLOSE);
919 Emit (Character'Val (Par_No));
920 else
921 Ender := Emit_Node (EOP);
922 end if;
923
924 Link_Tail (IP, Ender);
925
926 if Have_Branch and then Emit_Ptr <= PM.Size then
927
928 -- Hook the tails of the branches to the closing node
929
930 Br := IP;
931 loop
932 Link_Operand_Tail (Br, Ender);
933 Br2 := Get_Next (Program, Br);
934 exit when Br2 = Br;
935 Br := Br2;
936 end loop;
937 end if;
938
939 -- Check for proper termination
940
941 if Parenthesized then
942 if Parse_Pos > Parse_End or else E (Parse_Pos) /= ')' then
943 Fail ("unmatched ()");
944 end if;
945
946 Parse_Pos := Parse_Pos + 1;
947
948 elsif Parse_Pos <= Parse_End then
949 if E (Parse_Pos) = ')' then
950 Fail ("unmatched ()");
951 else
952 Fail ("junk on end"); -- "Can't happen"
953 end if;
954 end if;
955 end Parse;
956
957 ----------------
958 -- Parse_Atom --
959 ----------------
960
961 procedure Parse_Atom
962 (Expr_Flags : out Expression_Flags;
963 IP : out Pointer)
964 is
965 C : Character;
966
967 begin
968 -- Tentatively set worst expression case
969
970 Expr_Flags := Worst_Expression;
971
972 C := Expression (Parse_Pos);
973 Parse_Pos := Parse_Pos + 1;
974
975 case (C) is
976 when '^' =>
977 IP :=
978 Emit_Node
979 (if (Flags and Multiple_Lines) /= 0 then MBOL
980 elsif (Flags and Single_Line) /= 0 then SBOL
981 else BOL);
982
983 when '$' =>
984 IP :=
985 Emit_Node
986 (if (Flags and Multiple_Lines) /= 0 then MEOL
987 elsif (Flags and Single_Line) /= 0 then SEOL
988 else EOL);
989
990 when '.' =>
991 IP :=
992 Emit_Node
993 (if (Flags and Single_Line) /= 0 then SANY else ANY);
994
995 Expr_Flags.Has_Width := True;
996 Expr_Flags.Simple := True;
997
998 when '[' =>
999 Parse_Character_Class (IP);
1000 Expr_Flags.Has_Width := True;
1001 Expr_Flags.Simple := True;
1002
1003 when '(' =>
1004 declare
1005 New_Flags : Expression_Flags;
1006
1007 begin
1008 Parse (True, New_Flags, IP);
1009
1010 if IP = 0 then
1011 return;
1012 end if;
1013
1014 Expr_Flags.Has_Width :=
1015 Expr_Flags.Has_Width or else New_Flags.Has_Width;
1016 Expr_Flags.SP_Start :=
1017 Expr_Flags.SP_Start or else New_Flags.SP_Start;
1018 end;
1019
1020 when '|' | ASCII.LF | ')' =>
1021 Fail ("internal urp"); -- Supposed to be caught earlier
1022
1023 when '?' | '+' | '*' =>
1024 Fail (C & " follows nothing");
1025
1026 when '{' =>
1027 if Is_Curly_Operator (Parse_Pos - 1) then
1028 Fail (C & " follows nothing");
1029 else
1030 Parse_Literal (Expr_Flags, IP);
1031 end if;
1032
1033 when '\' =>
1034 if Parse_Pos > Parse_End then
1035 Fail ("trailing \");
1036 end if;
1037
1038 Parse_Pos := Parse_Pos + 1;
1039
1040 case Expression (Parse_Pos - 1) is
1041 when 'b' =>
1042 IP := Emit_Node (BOUND);
1043
1044 when 'B' =>
1045 IP := Emit_Node (NBOUND);
1046
1047 when 's' =>
1048 IP := Emit_Node (SPACE);
1049 Expr_Flags.Simple := True;
1050 Expr_Flags.Has_Width := True;
1051
1052 when 'S' =>
1053 IP := Emit_Node (NSPACE);
1054 Expr_Flags.Simple := True;
1055 Expr_Flags.Has_Width := True;
1056
1057 when 'd' =>
1058 IP := Emit_Node (DIGIT);
1059 Expr_Flags.Simple := True;
1060 Expr_Flags.Has_Width := True;
1061
1062 when 'D' =>
1063 IP := Emit_Node (NDIGIT);
1064 Expr_Flags.Simple := True;
1065 Expr_Flags.Has_Width := True;
1066
1067 when 'w' =>
1068 IP := Emit_Node (ALNUM);
1069 Expr_Flags.Simple := True;
1070 Expr_Flags.Has_Width := True;
1071
1072 when 'W' =>
1073 IP := Emit_Node (NALNUM);
1074 Expr_Flags.Simple := True;
1075 Expr_Flags.Has_Width := True;
1076
1077 when 'A' =>
1078 IP := Emit_Node (SBOL);
1079
1080 when 'G' =>
1081 IP := Emit_Node (SEOL);
1082
1083 when '0' .. '9' =>
1084 IP := Emit_Node (REFF);
1085
1086 declare
1087 Save : constant Natural := Parse_Pos - 1;
1088
1089 begin
1090 while Parse_Pos <= Expression'Last
1091 and then Is_Digit (Expression (Parse_Pos))
1092 loop
1093 Parse_Pos := Parse_Pos + 1;
1094 end loop;
1095
1096 Emit (Character'Val (Natural'Value
1097 (Expression (Save .. Parse_Pos - 1))));
1098 end;
1099
1100 when others =>
1101 Parse_Pos := Parse_Pos - 1;
1102 Parse_Literal (Expr_Flags, IP);
1103 end case;
1104
1105 when others =>
1106 Parse_Literal (Expr_Flags, IP);
1107 end case;
1108 end Parse_Atom;
1109
1110 ------------------
1111 -- Parse_Branch --
1112 ------------------
1113
1114 procedure Parse_Branch
1115 (Flags : out Expression_Flags;
1116 First : Boolean;
1117 IP : out Pointer)
1118 is
1119 E : String renames Expression;
1120 Chain : Pointer;
1121 Last : Pointer;
1122 New_Flags : Expression_Flags;
1123
1124 Discard : Pointer;
1125 pragma Warnings (Off, Discard);
1126
1127 begin
1128 Flags := Worst_Expression; -- Tentatively
1129 IP := (if First then Emit_Ptr else Emit_Node (BRANCH));
1130
1131 Chain := 0;
1132 while Parse_Pos <= Parse_End
1133 and then E (Parse_Pos) /= ')'
1134 and then E (Parse_Pos) /= ASCII.LF
1135 and then E (Parse_Pos) /= '|'
1136 loop
1137 Parse_Piece (New_Flags, Last);
1138
1139 if Last = 0 then
1140 IP := 0;
1141 return;
1142 end if;
1143
1144 Flags.Has_Width := Flags.Has_Width or else New_Flags.Has_Width;
1145
1146 if Chain = 0 then -- First piece
1147 Flags.SP_Start := Flags.SP_Start or else New_Flags.SP_Start;
1148 else
1149 Link_Tail (Chain, Last);
1150 end if;
1151
1152 Chain := Last;
1153 end loop;
1154
1155 -- Case where loop ran zero CURLY
1156
1157 if Chain = 0 then
1158 Discard := Emit_Node (NOTHING);
1159 end if;
1160 end Parse_Branch;
1161
1162 ---------------------------
1163 -- Parse_Character_Class --
1164 ---------------------------
1165
1166 procedure Parse_Character_Class (IP : out Pointer) is
1167 Bitmap : Character_Class;
1168 Invert : Boolean := False;
1169 In_Range : Boolean := False;
1170 Named_Class : Std_Class := ANYOF_NONE;
1171 Value : Character;
1172 Last_Value : Character := ASCII.NUL;
1173
1174 begin
1175 Reset_Class (Bitmap);
1176
1177 -- Do we have an invert character class ?
1178
1179 if Parse_Pos <= Parse_End
1180 and then Expression (Parse_Pos) = '^'
1181 then
1182 Invert := True;
1183 Parse_Pos := Parse_Pos + 1;
1184 end if;
1185
1186 -- First character can be ] or - without closing the class
1187
1188 if Parse_Pos <= Parse_End
1189 and then (Expression (Parse_Pos) = ']'
1190 or else Expression (Parse_Pos) = '-')
1191 then
1192 Set_In_Class (Bitmap, Expression (Parse_Pos));
1193 Parse_Pos := Parse_Pos + 1;
1194 end if;
1195
1196 -- While we don't have the end of the class
1197
1198 while Parse_Pos <= Parse_End
1199 and then Expression (Parse_Pos) /= ']'
1200 loop
1201 Named_Class := ANYOF_NONE;
1202 Value := Expression (Parse_Pos);
1203 Parse_Pos := Parse_Pos + 1;
1204
1205 -- Do we have a Posix character class
1206 if Value = '[' then
1207 Named_Class := Parse_Posix_Character_Class;
1208
1209 elsif Value = '\' then
1210 if Parse_Pos = Parse_End then
1211 Fail ("Trailing \");
1212 end if;
1213 Value := Expression (Parse_Pos);
1214 Parse_Pos := Parse_Pos + 1;
1215
1216 case Value is
1217 when 'w' => Named_Class := ANYOF_ALNUM;
1218 when 'W' => Named_Class := ANYOF_NALNUM;
1219 when 's' => Named_Class := ANYOF_SPACE;
1220 when 'S' => Named_Class := ANYOF_NSPACE;
1221 when 'd' => Named_Class := ANYOF_DIGIT;
1222 when 'D' => Named_Class := ANYOF_NDIGIT;
1223 when 'n' => Value := ASCII.LF;
1224 when 'r' => Value := ASCII.CR;
1225 when 't' => Value := ASCII.HT;
1226 when 'f' => Value := ASCII.FF;
1227 when 'e' => Value := ASCII.ESC;
1228 when 'a' => Value := ASCII.BEL;
1229
1230 -- when 'x' => ??? hexadecimal value
1231 -- when 'c' => ??? control character
1232 -- when '0'..'9' => ??? octal character
1233
1234 when others => null;
1235 end case;
1236 end if;
1237
1238 -- Do we have a character class?
1239
1240 if Named_Class /= ANYOF_NONE then
1241
1242 -- A range like 'a-\d' or 'a-[:digit:] is not a range
1243
1244 if In_Range then
1245 Set_In_Class (Bitmap, Last_Value);
1246 Set_In_Class (Bitmap, '-');
1247 In_Range := False;
1248 end if;
1249
1250 -- Expand the range
1251
1252 case Named_Class is
1253 when ANYOF_NONE => null;
1254
1255 when ANYOF_ALNUM | ANYOF_ALNUMC =>
1256 for Value in Class_Byte'Range loop
1257 if Is_Alnum (Character'Val (Value)) then
1258 Set_In_Class (Bitmap, Character'Val (Value));
1259 end if;
1260 end loop;
1261
1262 when ANYOF_NALNUM | ANYOF_NALNUMC =>
1263 for Value in Class_Byte'Range loop
1264 if not Is_Alnum (Character'Val (Value)) then
1265 Set_In_Class (Bitmap, Character'Val (Value));
1266 end if;
1267 end loop;
1268
1269 when ANYOF_SPACE =>
1270 for Value in Class_Byte'Range loop
1271 if Is_White_Space (Character'Val (Value)) then
1272 Set_In_Class (Bitmap, Character'Val (Value));
1273 end if;
1274 end loop;
1275
1276 when ANYOF_NSPACE =>
1277 for Value in Class_Byte'Range loop
1278 if not Is_White_Space (Character'Val (Value)) then
1279 Set_In_Class (Bitmap, Character'Val (Value));
1280 end if;
1281 end loop;
1282
1283 when ANYOF_DIGIT =>
1284 for Value in Class_Byte'Range loop
1285 if Is_Digit (Character'Val (Value)) then
1286 Set_In_Class (Bitmap, Character'Val (Value));
1287 end if;
1288 end loop;
1289
1290 when ANYOF_NDIGIT =>
1291 for Value in Class_Byte'Range loop
1292 if not Is_Digit (Character'Val (Value)) then
1293 Set_In_Class (Bitmap, Character'Val (Value));
1294 end if;
1295 end loop;
1296
1297 when ANYOF_ALPHA =>
1298 for Value in Class_Byte'Range loop
1299 if Is_Letter (Character'Val (Value)) then
1300 Set_In_Class (Bitmap, Character'Val (Value));
1301 end if;
1302 end loop;
1303
1304 when ANYOF_NALPHA =>
1305 for Value in Class_Byte'Range loop
1306 if not Is_Letter (Character'Val (Value)) then
1307 Set_In_Class (Bitmap, Character'Val (Value));
1308 end if;
1309 end loop;
1310
1311 when ANYOF_ASCII =>
1312 for Value in 0 .. 127 loop
1313 Set_In_Class (Bitmap, Character'Val (Value));
1314 end loop;
1315
1316 when ANYOF_NASCII =>
1317 for Value in 128 .. 255 loop
1318 Set_In_Class (Bitmap, Character'Val (Value));
1319 end loop;
1320
1321 when ANYOF_CNTRL =>
1322 for Value in Class_Byte'Range loop
1323 if Is_Control (Character'Val (Value)) then
1324 Set_In_Class (Bitmap, Character'Val (Value));
1325 end if;
1326 end loop;
1327
1328 when ANYOF_NCNTRL =>
1329 for Value in Class_Byte'Range loop
1330 if not Is_Control (Character'Val (Value)) then
1331 Set_In_Class (Bitmap, Character'Val (Value));
1332 end if;
1333 end loop;
1334
1335 when ANYOF_GRAPH =>
1336 for Value in Class_Byte'Range loop
1337 if Is_Graphic (Character'Val (Value)) then
1338 Set_In_Class (Bitmap, Character'Val (Value));
1339 end if;
1340 end loop;
1341
1342 when ANYOF_NGRAPH =>
1343 for Value in Class_Byte'Range loop
1344 if not Is_Graphic (Character'Val (Value)) then
1345 Set_In_Class (Bitmap, Character'Val (Value));
1346 end if;
1347 end loop;
1348
1349 when ANYOF_LOWER =>
1350 for Value in Class_Byte'Range loop
1351 if Is_Lower (Character'Val (Value)) then
1352 Set_In_Class (Bitmap, Character'Val (Value));
1353 end if;
1354 end loop;
1355
1356 when ANYOF_NLOWER =>
1357 for Value in Class_Byte'Range loop
1358 if not Is_Lower (Character'Val (Value)) then
1359 Set_In_Class (Bitmap, Character'Val (Value));
1360 end if;
1361 end loop;
1362
1363 when ANYOF_PRINT =>
1364 for Value in Class_Byte'Range loop
1365 if Is_Printable (Character'Val (Value)) then
1366 Set_In_Class (Bitmap, Character'Val (Value));
1367 end if;
1368 end loop;
1369
1370 when ANYOF_NPRINT =>
1371 for Value in Class_Byte'Range loop
1372 if not Is_Printable (Character'Val (Value)) then
1373 Set_In_Class (Bitmap, Character'Val (Value));
1374 end if;
1375 end loop;
1376
1377 when ANYOF_PUNCT =>
1378 for Value in Class_Byte'Range loop
1379 if Is_Printable (Character'Val (Value))
1380 and then not Is_White_Space (Character'Val (Value))
1381 and then not Is_Alnum (Character'Val (Value))
1382 then
1383 Set_In_Class (Bitmap, Character'Val (Value));
1384 end if;
1385 end loop;
1386
1387 when ANYOF_NPUNCT =>
1388 for Value in Class_Byte'Range loop
1389 if not Is_Printable (Character'Val (Value))
1390 or else Is_White_Space (Character'Val (Value))
1391 or else Is_Alnum (Character'Val (Value))
1392 then
1393 Set_In_Class (Bitmap, Character'Val (Value));
1394 end if;
1395 end loop;
1396
1397 when ANYOF_UPPER =>
1398 for Value in Class_Byte'Range loop
1399 if Is_Upper (Character'Val (Value)) then
1400 Set_In_Class (Bitmap, Character'Val (Value));
1401 end if;
1402 end loop;
1403
1404 when ANYOF_NUPPER =>
1405 for Value in Class_Byte'Range loop
1406 if not Is_Upper (Character'Val (Value)) then
1407 Set_In_Class (Bitmap, Character'Val (Value));
1408 end if;
1409 end loop;
1410
1411 when ANYOF_XDIGIT =>
1412 for Value in Class_Byte'Range loop
1413 if Is_Hexadecimal_Digit (Character'Val (Value)) then
1414 Set_In_Class (Bitmap, Character'Val (Value));
1415 end if;
1416 end loop;
1417
1418 when ANYOF_NXDIGIT =>
1419 for Value in Class_Byte'Range loop
1420 if not Is_Hexadecimal_Digit
1421 (Character'Val (Value))
1422 then
1423 Set_In_Class (Bitmap, Character'Val (Value));
1424 end if;
1425 end loop;
1426
1427 end case;
1428
1429 -- Not a character range
1430
1431 elsif not In_Range then
1432 Last_Value := Value;
1433
1434 if Parse_Pos > Expression'Last then
1435 Fail ("Empty character class []");
1436 end if;
1437
1438 if Expression (Parse_Pos) = '-'
1439 and then Parse_Pos < Parse_End
1440 and then Expression (Parse_Pos + 1) /= ']'
1441 then
1442 Parse_Pos := Parse_Pos + 1;
1443
1444 -- Do we have a range like '\d-a' and '[:space:]-a'
1445 -- which is not a real range
1446
1447 if Named_Class /= ANYOF_NONE then
1448 Set_In_Class (Bitmap, '-');
1449 else
1450 In_Range := True;
1451 end if;
1452
1453 else
1454 Set_In_Class (Bitmap, Value);
1455
1456 end if;
1457
1458 -- Else in a character range
1459
1460 else
1461 if Last_Value > Value then
1462 Fail ("Invalid Range [" & Last_Value'Img
1463 & "-" & Value'Img & "]");
1464 end if;
1465
1466 while Last_Value <= Value loop
1467 Set_In_Class (Bitmap, Last_Value);
1468 Last_Value := Character'Succ (Last_Value);
1469 end loop;
1470
1471 In_Range := False;
1472
1473 end if;
1474
1475 end loop;
1476
1477 -- Optimize case-insensitive ranges (put the upper case or lower
1478 -- case character into the bitmap)
1479
1480 if (Flags and Case_Insensitive) /= 0 then
1481 for C in Character'Range loop
1482 if Get_From_Class (Bitmap, C) then
1483 Set_In_Class (Bitmap, To_Lower (C));
1484 Set_In_Class (Bitmap, To_Upper (C));
1485 end if;
1486 end loop;
1487 end if;
1488
1489 -- Optimize inverted classes
1490
1491 if Invert then
1492 for J in Bitmap'Range loop
1493 Bitmap (J) := not Bitmap (J);
1494 end loop;
1495 end if;
1496
1497 Parse_Pos := Parse_Pos + 1;
1498
1499 -- Emit the class
1500
1501 IP := Emit_Node (ANYOF);
1502 Emit_Class (Bitmap);
1503 end Parse_Character_Class;
1504
1505 -------------------
1506 -- Parse_Literal --
1507 -------------------
1508
1509 -- This is a bit tricky due to quoted chars and due to
1510 -- the multiplier characters '*', '+', and '?' that
1511 -- take the SINGLE char previous as their operand.
1512
1513 -- On entry, the character at Parse_Pos - 1 is going to go
1514 -- into the string, no matter what it is. It could be
1515 -- following a \ if Parse_Atom was entered from the '\' case.
1516
1517 -- Basic idea is to pick up a good char in C and examine
1518 -- the next char. If Is_Mult (C) then twiddle, if it's a \
1519 -- then frozzle and if it's another magic char then push C and
1520 -- terminate the string. If none of the above, push C on the
1521 -- string and go around again.
1522
1523 -- Start_Pos is used to remember where "the current character"
1524 -- starts in the string, if due to an Is_Mult we need to back
1525 -- up and put the current char in a separate 1-character string.
1526 -- When Start_Pos is 0, C is the only char in the string;
1527 -- this is used in Is_Mult handling, and in setting the SIMPLE
1528 -- flag at the end.
1529
1530 procedure Parse_Literal
1531 (Expr_Flags : out Expression_Flags;
1532 IP : out Pointer)
1533 is
1534 Start_Pos : Natural := 0;
1535 C : Character;
1536 Length_Ptr : Pointer;
1537
1538 Has_Special_Operator : Boolean := False;
1539
1540 begin
1541 Parse_Pos := Parse_Pos - 1; -- Look at current character
1542
1543 IP :=
1544 Emit_Node
1545 (if (Flags and Case_Insensitive) /= 0 then EXACTF else EXACT);
1546
1547 Length_Ptr := Emit_Ptr;
1548 Emit_Ptr := String_Operand (IP);
1549
1550 Parse_Loop :
1551 loop
1552 C := Expression (Parse_Pos); -- Get current character
1553
1554 case C is
1555 when '.' | '[' | '(' | ')' | '|' | ASCII.LF | '$' | '^' =>
1556
1557 if Start_Pos = 0 then
1558 Start_Pos := Parse_Pos;
1559 Emit (C); -- First character is always emitted
1560 else
1561 exit Parse_Loop; -- Else we are done
1562 end if;
1563
1564 when '?' | '+' | '*' | '{' =>
1565
1566 if Start_Pos = 0 then
1567 Start_Pos := Parse_Pos;
1568 Emit (C); -- First character is always emitted
1569
1570 -- Are we looking at an operator, or is this
1571 -- simply a normal character ?
1572
1573 elsif not Is_Mult (Parse_Pos) then
1574 Start_Pos := Parse_Pos;
1575 Case_Emit (C);
1576
1577 else
1578 -- We've got something like "abc?d". Mark this as a
1579 -- special case. What we want to emit is a first
1580 -- constant string for "ab", then one for "c" that will
1581 -- ultimately be transformed with a CURLY operator, A
1582 -- special case has to be handled for "a?", since there
1583 -- is no initial string to emit.
1584
1585 Has_Special_Operator := True;
1586 exit Parse_Loop;
1587 end if;
1588
1589 when '\' =>
1590 Start_Pos := Parse_Pos;
1591
1592 if Parse_Pos = Parse_End then
1593 Fail ("Trailing \");
1594
1595 else
1596 case Expression (Parse_Pos + 1) is
1597 when 'b' | 'B' | 's' | 'S' | 'd' | 'D'
1598 | 'w' | 'W' | '0' .. '9' | 'G' | 'A'
1599 => exit Parse_Loop;
1600 when 'n' => Emit (ASCII.LF);
1601 when 't' => Emit (ASCII.HT);
1602 when 'r' => Emit (ASCII.CR);
1603 when 'f' => Emit (ASCII.FF);
1604 when 'e' => Emit (ASCII.ESC);
1605 when 'a' => Emit (ASCII.BEL);
1606 when others => Emit (Expression (Parse_Pos + 1));
1607 end case;
1608
1609 Parse_Pos := Parse_Pos + 1;
1610 end if;
1611
1612 when others =>
1613 Start_Pos := Parse_Pos;
1614 Case_Emit (C);
1615 end case;
1616
1617 exit Parse_Loop when Emit_Ptr - Length_Ptr = 254;
1618
1619 Parse_Pos := Parse_Pos + 1;
1620
1621 exit Parse_Loop when Parse_Pos > Parse_End;
1622 end loop Parse_Loop;
1623
1624 -- Is the string followed by a '*+?{' operator ? If yes, and if there
1625 -- is an initial string to emit, do it now.
1626
1627 if Has_Special_Operator
1628 and then Emit_Ptr >= Length_Ptr + Next_Pointer_Bytes
1629 then
1630 Emit_Ptr := Emit_Ptr - 1;
1631 Parse_Pos := Start_Pos;
1632 end if;
1633
1634 if Length_Ptr <= PM.Size then
1635 Program (Length_Ptr) := Character'Val (Emit_Ptr - Length_Ptr - 2);
1636 end if;
1637
1638 Expr_Flags.Has_Width := True;
1639
1640 -- Slight optimization when there is a single character
1641
1642 if Emit_Ptr = Length_Ptr + 2 then
1643 Expr_Flags.Simple := True;
1644 end if;
1645 end Parse_Literal;
1646
1647 -----------------
1648 -- Parse_Piece --
1649 -----------------
1650
1651 -- Note that the branching code sequences used for '?' and the
1652 -- general cases of '*' and + are somewhat optimized: they use
1653 -- the same NOTHING node as both the endmarker for their branch
1654 -- list and the body of the last branch. It might seem that
1655 -- this node could be dispensed with entirely, but the endmarker
1656 -- role is not redundant.
1657
1658 procedure Parse_Piece
1659 (Expr_Flags : out Expression_Flags;
1660 IP : out Pointer)
1661 is
1662 Op : Character;
1663 New_Flags : Expression_Flags;
1664 Greedy : Boolean := True;
1665
1666 begin
1667 Parse_Atom (New_Flags, IP);
1668
1669 if IP = 0 then
1670 return;
1671 end if;
1672
1673 if Parse_Pos > Parse_End
1674 or else not Is_Mult (Parse_Pos)
1675 then
1676 Expr_Flags := New_Flags;
1677 return;
1678 end if;
1679
1680 Op := Expression (Parse_Pos);
1681
1682 Expr_Flags :=
1683 (if Op /= '+'
1684 then (SP_Start => True, others => False)
1685 else (Has_Width => True, others => False));
1686
1687 -- Detect non greedy operators in the easy cases
1688
1689 if Op /= '{'
1690 and then Parse_Pos + 1 <= Parse_End
1691 and then Expression (Parse_Pos + 1) = '?'
1692 then
1693 Greedy := False;
1694 Parse_Pos := Parse_Pos + 1;
1695 end if;
1696
1697 -- Generate the byte code
1698
1699 case Op is
1700 when '*' =>
1701
1702 if New_Flags.Simple then
1703 Insert_Operator (STAR, IP, Greedy);
1704 else
1705 Link_Tail (IP, Emit_Node (WHILEM));
1706 Insert_Curly_Operator
1707 (CURLYX, 0, Max_Curly_Repeat, IP, Greedy);
1708 Link_Tail (IP, Emit_Node (NOTHING));
1709 end if;
1710
1711 when '+' =>
1712
1713 if New_Flags.Simple then
1714 Insert_Operator (PLUS, IP, Greedy);
1715 else
1716 Link_Tail (IP, Emit_Node (WHILEM));
1717 Insert_Curly_Operator
1718 (CURLYX, 1, Max_Curly_Repeat, IP, Greedy);
1719 Link_Tail (IP, Emit_Node (NOTHING));
1720 end if;
1721
1722 when '?' =>
1723 if New_Flags.Simple then
1724 Insert_Curly_Operator (CURLY, 0, 1, IP, Greedy);
1725 else
1726 Link_Tail (IP, Emit_Node (WHILEM));
1727 Insert_Curly_Operator (CURLYX, 0, 1, IP, Greedy);
1728 Link_Tail (IP, Emit_Node (NOTHING));
1729 end if;
1730
1731 when '{' =>
1732 declare
1733 Min, Max : Natural;
1734
1735 begin
1736 Get_Curly_Arguments (Parse_Pos, Min, Max, Greedy);
1737
1738 if New_Flags.Simple then
1739 Insert_Curly_Operator (CURLY, Min, Max, IP, Greedy);
1740 else
1741 Link_Tail (IP, Emit_Node (WHILEM));
1742 Insert_Curly_Operator (CURLYX, Min, Max, IP, Greedy);
1743 Link_Tail (IP, Emit_Node (NOTHING));
1744 end if;
1745 end;
1746
1747 when others =>
1748 null;
1749 end case;
1750
1751 Parse_Pos := Parse_Pos + 1;
1752
1753 if Parse_Pos <= Parse_End
1754 and then Is_Mult (Parse_Pos)
1755 then
1756 Fail ("nested *+{");
1757 end if;
1758 end Parse_Piece;
1759
1760 ---------------------------------
1761 -- Parse_Posix_Character_Class --
1762 ---------------------------------
1763
1764 function Parse_Posix_Character_Class return Std_Class is
1765 Invert : Boolean := False;
1766 Class : Std_Class := ANYOF_NONE;
1767 E : String renames Expression;
1768
1769 -- Class names. Note that code assumes that the length of all
1770 -- classes starting with the same letter have the same length.
1771
1772 Alnum : constant String := "alnum:]";
1773 Alpha : constant String := "alpha:]";
1774 Ascii_C : constant String := "ascii:]";
1775 Cntrl : constant String := "cntrl:]";
1776 Digit : constant String := "digit:]";
1777 Graph : constant String := "graph:]";
1778 Lower : constant String := "lower:]";
1779 Print : constant String := "print:]";
1780 Punct : constant String := "punct:]";
1781 Space : constant String := "space:]";
1782 Upper : constant String := "upper:]";
1783 Word : constant String := "word:]";
1784 Xdigit : constant String := "xdigit:]";
1785
1786 begin
1787 -- Case of character class specified
1788
1789 if Parse_Pos <= Parse_End
1790 and then Expression (Parse_Pos) = ':'
1791 then
1792 Parse_Pos := Parse_Pos + 1;
1793
1794 -- Do we have something like: [[:^alpha:]]
1795
1796 if Parse_Pos <= Parse_End
1797 and then Expression (Parse_Pos) = '^'
1798 then
1799 Invert := True;
1800 Parse_Pos := Parse_Pos + 1;
1801 end if;
1802
1803 -- Check for class names based on first letter
1804
1805 case Expression (Parse_Pos) is
1806 when 'a' =>
1807
1808 -- All 'a' classes have the same length (Alnum'Length)
1809
1810 if Parse_Pos + Alnum'Length - 1 <= Parse_End then
1811 if
1812 E (Parse_Pos .. Parse_Pos + Alnum'Length - 1) = Alnum
1813 then
1814 Class :=
1815 (if Invert then ANYOF_NALNUMC else ANYOF_ALNUMC);
1816 Parse_Pos := Parse_Pos + Alnum'Length;
1817
1818 elsif
1819 E (Parse_Pos .. Parse_Pos + Alpha'Length - 1) = Alpha
1820 then
1821 Class :=
1822 (if Invert then ANYOF_NALPHA else ANYOF_ALPHA);
1823 Parse_Pos := Parse_Pos + Alpha'Length;
1824
1825 elsif E (Parse_Pos .. Parse_Pos + Ascii_C'Length - 1) =
1826 Ascii_C
1827 then
1828 Class :=
1829 (if Invert then ANYOF_NASCII else ANYOF_ASCII);
1830 Parse_Pos := Parse_Pos + Ascii_C'Length;
1831 else
1832 Fail ("Invalid character class: " & E);
1833 end if;
1834
1835 else
1836 Fail ("Invalid character class: " & E);
1837 end if;
1838
1839 when 'c' =>
1840 if Parse_Pos + Cntrl'Length - 1 <= Parse_End
1841 and then
1842 E (Parse_Pos .. Parse_Pos + Cntrl'Length - 1) = Cntrl
1843 then
1844 Class := (if Invert then ANYOF_NCNTRL else ANYOF_CNTRL);
1845 Parse_Pos := Parse_Pos + Cntrl'Length;
1846 else
1847 Fail ("Invalid character class: " & E);
1848 end if;
1849
1850 when 'd' =>
1851 if Parse_Pos + Digit'Length - 1 <= Parse_End
1852 and then
1853 E (Parse_Pos .. Parse_Pos + Digit'Length - 1) = Digit
1854 then
1855 Class := (if Invert then ANYOF_NDIGIT else ANYOF_DIGIT);
1856 Parse_Pos := Parse_Pos + Digit'Length;
1857 end if;
1858
1859 when 'g' =>
1860 if Parse_Pos + Graph'Length - 1 <= Parse_End
1861 and then
1862 E (Parse_Pos .. Parse_Pos + Graph'Length - 1) = Graph
1863 then
1864 Class := (if Invert then ANYOF_NGRAPH else ANYOF_GRAPH);
1865 Parse_Pos := Parse_Pos + Graph'Length;
1866 else
1867 Fail ("Invalid character class: " & E);
1868 end if;
1869
1870 when 'l' =>
1871 if Parse_Pos + Lower'Length - 1 <= Parse_End
1872 and then
1873 E (Parse_Pos .. Parse_Pos + Lower'Length - 1) = Lower
1874 then
1875 Class := (if Invert then ANYOF_NLOWER else ANYOF_LOWER);
1876 Parse_Pos := Parse_Pos + Lower'Length;
1877 else
1878 Fail ("Invalid character class: " & E);
1879 end if;
1880
1881 when 'p' =>
1882
1883 -- All 'p' classes have the same length
1884
1885 if Parse_Pos + Print'Length - 1 <= Parse_End then
1886 if
1887 E (Parse_Pos .. Parse_Pos + Print'Length - 1) = Print
1888 then
1889 Class :=
1890 (if Invert then ANYOF_NPRINT else ANYOF_PRINT);
1891 Parse_Pos := Parse_Pos + Print'Length;
1892
1893 elsif
1894 E (Parse_Pos .. Parse_Pos + Punct'Length - 1) = Punct
1895 then
1896 Class :=
1897 (if Invert then ANYOF_NPUNCT else ANYOF_PUNCT);
1898 Parse_Pos := Parse_Pos + Punct'Length;
1899
1900 else
1901 Fail ("Invalid character class: " & E);
1902 end if;
1903
1904 else
1905 Fail ("Invalid character class: " & E);
1906 end if;
1907
1908 when 's' =>
1909 if Parse_Pos + Space'Length - 1 <= Parse_End
1910 and then
1911 E (Parse_Pos .. Parse_Pos + Space'Length - 1) = Space
1912 then
1913 Class := (if Invert then ANYOF_NSPACE else ANYOF_SPACE);
1914 Parse_Pos := Parse_Pos + Space'Length;
1915 else
1916 Fail ("Invalid character class: " & E);
1917 end if;
1918
1919 when 'u' =>
1920 if Parse_Pos + Upper'Length - 1 <= Parse_End
1921 and then
1922 E (Parse_Pos .. Parse_Pos + Upper'Length - 1) = Upper
1923 then
1924 Class := (if Invert then ANYOF_NUPPER else ANYOF_UPPER);
1925 Parse_Pos := Parse_Pos + Upper'Length;
1926 else
1927 Fail ("Invalid character class: " & E);
1928 end if;
1929
1930 when 'w' =>
1931 if Parse_Pos + Word'Length - 1 <= Parse_End
1932 and then
1933 E (Parse_Pos .. Parse_Pos + Word'Length - 1) = Word
1934 then
1935 Class := (if Invert then ANYOF_NALNUM else ANYOF_ALNUM);
1936 Parse_Pos := Parse_Pos + Word'Length;
1937 else
1938 Fail ("Invalid character class: " & E);
1939 end if;
1940
1941 when 'x' =>
1942 if Parse_Pos + Xdigit'Length - 1 <= Parse_End
1943 and then
1944 E (Parse_Pos .. Parse_Pos + Xdigit'Length - 1) = Xdigit
1945 then
1946 Class := (if Invert then ANYOF_NXDIGIT else ANYOF_XDIGIT);
1947 Parse_Pos := Parse_Pos + Xdigit'Length;
1948
1949 else
1950 Fail ("Invalid character class: " & E);
1951 end if;
1952
1953 when others =>
1954 Fail ("Invalid character class: " & E);
1955 end case;
1956
1957 -- Character class not specified
1958
1959 else
1960 return ANYOF_NONE;
1961 end if;
1962
1963 return Class;
1964 end Parse_Posix_Character_Class;
1965
1966 -- Local Declarations
1967
1968 Result : Pointer;
1969
1970 Expr_Flags : Expression_Flags;
1971 pragma Unreferenced (Expr_Flags);
1972
1973 -- Start of processing for Compile
1974
1975 begin
1976 Parse (False, Expr_Flags, Result);
1977
1978 if Result = 0 then
1979 Fail ("Couldn't compile expression");
1980 end if;
1981
1982 Final_Code_Size := Emit_Ptr - 1;
1983
1984 -- Do we want to actually compile the expression, or simply get the
1985 -- code size ???
1986
1987 if Emit_Ptr <= PM.Size then
1988 Optimize (PM);
1989 end if;
1990
1991 PM.Flags := Flags;
1992 end Compile;
1993
1994 function Compile
1995 (Expression : String;
1996 Flags : Regexp_Flags := No_Flags) return Pattern_Matcher
1997 is
1998 -- Assume the compiled regexp will fit in 1000 chars. If it does not we
1999 -- will have to compile a second time once the correct size is known. If
2000 -- it fits, we save a significant amount of time by avoiding the second
2001 -- compilation.
2002
2003 Dummy : Pattern_Matcher (1000);
2004 Size : Program_Size;
2005
2006 begin
2007 Compile (Dummy, Expression, Size, Flags);
2008
2009 if Size <= Dummy.Size then
2010 return Pattern_Matcher'
2011 (Size => Size,
2012 First => Dummy.First,
2013 Anchored => Dummy.Anchored,
2014 Must_Have => Dummy.Must_Have,
2015 Must_Have_Length => Dummy.Must_Have_Length,
2016 Paren_Count => Dummy.Paren_Count,
2017 Flags => Dummy.Flags,
2018 Program => Dummy.Program
2019 (Dummy.Program'First .. Dummy.Program'First + Size - 1));
2020 else
2021 -- We have to recompile now that we know the size
2022 -- ??? Can we use Ada05's return construct ?
2023 declare
2024 Result : Pattern_Matcher (Size);
2025 begin
2026 Compile (Result, Expression, Size, Flags);
2027 return Result;
2028 end;
2029 end if;
2030 end Compile;
2031
2032 procedure Compile
2033 (Matcher : out Pattern_Matcher;
2034 Expression : String;
2035 Flags : Regexp_Flags := No_Flags)
2036 is
2037 Size : Program_Size;
2038
2039 begin
2040 Compile (Matcher, Expression, Size, Flags);
2041
2042 if Size > Matcher.Size then
2043 raise Expression_Error with "Pattern_Matcher is too small";
2044 end if;
2045 end Compile;
2046
2047 --------------------
2048 -- Dump_Operation --
2049 --------------------
2050
2051 procedure Dump_Operation
2052 (Program : Program_Data;
2053 Index : Pointer;
2054 Indent : Natural)
2055 is
2056 Current : Pointer := Index;
2057 begin
2058 Dump_Until (Program, Current, Current + 1, Indent);
2059 end Dump_Operation;
2060
2061 ----------------
2062 -- Dump_Until --
2063 ----------------
2064
2065 procedure Dump_Until
2066 (Program : Program_Data;
2067 Index : in out Pointer;
2068 Till : Pointer;
2069 Indent : Natural;
2070 Do_Print : Boolean := True)
2071 is
2072 function Image (S : String) return String;
2073 -- Remove leading space
2074
2075 -----------
2076 -- Image --
2077 -----------
2078
2079 function Image (S : String) return String is
2080 begin
2081 if S (S'First) = ' ' then
2082 return S (S'First + 1 .. S'Last);
2083 else
2084 return S;
2085 end if;
2086 end Image;
2087
2088 -- Local variables
2089
2090 Op : Opcode;
2091 Next : Pointer;
2092 Length : Pointer;
2093 Local_Indent : Natural := Indent;
2094
2095 -- Start of processing for Dump_Until
2096
2097 begin
2098 while Index < Till loop
2099 Op := Opcode'Val (Character'Pos ((Program (Index))));
2100 Next := Get_Next (Program, Index);
2101
2102 if Do_Print then
2103 declare
2104 Point : constant String := Pointer'Image (Index);
2105 begin
2106 Put ((1 .. 4 - Point'Length => ' ')
2107 & Point & ":"
2108 & (1 .. Local_Indent * 2 => ' ') & Opcode'Image (Op));
2109 end;
2110
2111 -- Print the parenthesis number
2112
2113 if Op = OPEN or else Op = CLOSE or else Op = REFF then
2114 Put (Image (Natural'Image
2115 (Character'Pos
2116 (Program (Index + Next_Pointer_Bytes)))));
2117 end if;
2118
2119 if Next = Index then
2120 Put (" (-)");
2121 else
2122 Put (" (" & Image (Pointer'Image (Next)) & ")");
2123 end if;
2124 end if;
2125
2126 case Op is
2127 when ANYOF =>
2128 declare
2129 Bitmap : Character_Class;
2130 Last : Character := ASCII.NUL;
2131 Current : Natural := 0;
2132 Current_Char : Character;
2133
2134 begin
2135 Bitmap_Operand (Program, Index, Bitmap);
2136
2137 if Do_Print then
2138 Put ("[");
2139
2140 while Current <= 255 loop
2141 Current_Char := Character'Val (Current);
2142
2143 -- First item in a range
2144
2145 if Get_From_Class (Bitmap, Current_Char) then
2146 Last := Current_Char;
2147
2148 -- Search for the last item in the range
2149
2150 loop
2151 Current := Current + 1;
2152 exit when Current > 255;
2153 Current_Char := Character'Val (Current);
2154 exit when
2155 not Get_From_Class (Bitmap, Current_Char);
2156 end loop;
2157
2158 if not Is_Graphic (Last) then
2159 Put (Last'Img);
2160 else
2161 Put (Last);
2162 end if;
2163
2164 if Character'Succ (Last) /= Current_Char then
2165 Put ("\-" & Character'Pred (Current_Char));
2166 end if;
2167
2168 else
2169 Current := Current + 1;
2170 end if;
2171 end loop;
2172
2173 Put_Line ("]");
2174 end if;
2175
2176 Index := Index + Next_Pointer_Bytes + Bitmap'Length;
2177 end;
2178
2179 when EXACT | EXACTF =>
2180 Length := String_Length (Program, Index);
2181 if Do_Print then
2182 Put (" (" & Image (Program_Size'Image (Length + 1))
2183 & " chars) <"
2184 & String (Program (String_Operand (Index)
2185 .. String_Operand (Index)
2186 + Length)));
2187 Put_Line (">");
2188 end if;
2189
2190 Index := String_Operand (Index) + Length + 1;
2191
2192 -- Node operand
2193
2194 when BRANCH | STAR | PLUS =>
2195 if Do_Print then
2196 New_Line;
2197 end if;
2198
2199 Index := Index + Next_Pointer_Bytes;
2200 Dump_Until (Program, Index, Pointer'Min (Next, Till),
2201 Local_Indent + 1, Do_Print);
2202
2203 when CURLY | CURLYX =>
2204 if Do_Print then
2205 Put_Line
2206 (" {"
2207 & Image (Natural'Image
2208 (Read_Natural (Program, Index + Next_Pointer_Bytes)))
2209 & ","
2210 & Image (Natural'Image (Read_Natural (Program, Index + 5)))
2211 & "}");
2212 end if;
2213
2214 Index := Index + 7;
2215 Dump_Until (Program, Index, Pointer'Min (Next, Till),
2216 Local_Indent + 1, Do_Print);
2217
2218 when OPEN =>
2219 if Do_Print then
2220 New_Line;
2221 end if;
2222
2223 Index := Index + 4;
2224 Local_Indent := Local_Indent + 1;
2225
2226 when CLOSE | REFF =>
2227 if Do_Print then
2228 New_Line;
2229 end if;
2230
2231 Index := Index + 4;
2232
2233 if Op = CLOSE then
2234 Local_Indent := Local_Indent - 1;
2235 end if;
2236
2237 when others =>
2238 Index := Index + Next_Pointer_Bytes;
2239
2240 if Do_Print then
2241 New_Line;
2242 end if;
2243
2244 exit when Op = EOP;
2245 end case;
2246 end loop;
2247 end Dump_Until;
2248
2249 ----------
2250 -- Dump --
2251 ----------
2252
2253 procedure Dump (Self : Pattern_Matcher) is
2254 Program : Program_Data renames Self.Program;
2255 Index : Pointer := Program'First;
2256
2257 -- Start of processing for Dump
2258
2259 begin
2260 Put_Line ("Must start with (Self.First) = "
2261 & Character'Image (Self.First));
2262
2263 if (Self.Flags and Case_Insensitive) /= 0 then
2264 Put_Line (" Case_Insensitive mode");
2265 end if;
2266
2267 if (Self.Flags and Single_Line) /= 0 then
2268 Put_Line (" Single_Line mode");
2269 end if;
2270
2271 if (Self.Flags and Multiple_Lines) /= 0 then
2272 Put_Line (" Multiple_Lines mode");
2273 end if;
2274
2275 Dump_Until (Program, Index, Self.Program'Last + 1, 0);
2276 end Dump;
2277
2278 --------------------
2279 -- Get_From_Class --
2280 --------------------
2281
2282 function Get_From_Class
2283 (Bitmap : Character_Class;
2284 C : Character) return Boolean
2285 is
2286 Value : constant Class_Byte := Character'Pos (C);
2287 begin
2288 return
2289 (Bitmap (Value / 8) and Bit_Conversion (Value mod 8)) /= 0;
2290 end Get_From_Class;
2291
2292 --------------
2293 -- Get_Next --
2294 --------------
2295
2296 function Get_Next (Program : Program_Data; IP : Pointer) return Pointer is
2297 begin
2298 return IP + Pointer (Read_Natural (Program, IP + 1));
2299 end Get_Next;
2300
2301 --------------
2302 -- Is_Alnum --
2303 --------------
2304
2305 function Is_Alnum (C : Character) return Boolean is
2306 begin
2307 return Is_Alphanumeric (C) or else C = '_';
2308 end Is_Alnum;
2309
2310 ------------------
2311 -- Is_Printable --
2312 ------------------
2313
2314 function Is_Printable (C : Character) return Boolean is
2315 begin
2316 -- Printable if space or graphic character or other whitespace
2317 -- Other white space includes (HT/LF/VT/FF/CR = codes 9-13)
2318
2319 return C in Character'Val (32) .. Character'Val (126)
2320 or else C in ASCII.HT .. ASCII.CR;
2321 end Is_Printable;
2322
2323 --------------------
2324 -- Is_White_Space --
2325 --------------------
2326
2327 function Is_White_Space (C : Character) return Boolean is
2328 begin
2329 -- Note: HT = 9, LF = 10, VT = 11, FF = 12, CR = 13
2330
2331 return C = ' ' or else C in ASCII.HT .. ASCII.CR;
2332 end Is_White_Space;
2333
2334 -----------
2335 -- Match --
2336 -----------
2337
2338 procedure Match
2339 (Self : Pattern_Matcher;
2340 Data : String;
2341 Matches : out Match_Array;
2342 Data_First : Integer := -1;
2343 Data_Last : Positive := Positive'Last)
2344 is
2345 Program : Program_Data renames Self.Program; -- Shorter notation
2346
2347 First_In_Data : constant Integer := Integer'Max (Data_First, Data'First);
2348 Last_In_Data : constant Integer := Integer'Min (Data_Last, Data'Last);
2349
2350 -- Global work variables
2351
2352 Input_Pos : Natural; -- String-input pointer
2353 BOL_Pos : Natural; -- Beginning of input, for ^ check
2354 Matched : Boolean := False; -- Until proven True
2355
2356 Matches_Full : Match_Array (0 .. Natural'Max (Self.Paren_Count,
2357 Matches'Last));
2358 -- Stores the value of all the parenthesis pairs.
2359 -- We do not use directly Matches, so that we can also use back
2360 -- references (REFF) even if Matches is too small.
2361
2362 type Natural_Array is array (Match_Count range <>) of Natural;
2363 Matches_Tmp : Natural_Array (Matches_Full'Range);
2364 -- Save the opening position of parenthesis
2365
2366 Last_Paren : Natural := 0;
2367 -- Last parenthesis seen
2368
2369 Greedy : Boolean := True;
2370 -- True if the next operator should be greedy
2371
2372 type Current_Curly_Record;
2373 type Current_Curly_Access is access all Current_Curly_Record;
2374 type Current_Curly_Record is record
2375 Paren_Floor : Natural; -- How far back to strip parenthesis data
2376 Cur : Integer; -- How many instances of scan we've matched
2377 Min : Natural; -- Minimal number of scans to match
2378 Max : Natural; -- Maximal number of scans to match
2379 Greedy : Boolean; -- Whether to work our way up or down
2380 Scan : Pointer; -- The thing to match
2381 Next : Pointer; -- What has to match after it
2382 Lastloc : Natural; -- Where we started matching this scan
2383 Old_Cc : Current_Curly_Access; -- Before we started this one
2384 end record;
2385 -- Data used to handle the curly operator and the plus and star
2386 -- operators for complex expressions.
2387
2388 Current_Curly : Current_Curly_Access := null;
2389 -- The curly currently being processed
2390
2391 -----------------------
2392 -- Local Subprograms --
2393 -----------------------
2394
2395 function Index (Start : Positive; C : Character) return Natural;
2396 -- Find character C in Data starting at Start and return position
2397
2398 function Repeat
2399 (IP : Pointer;
2400 Max : Natural := Natural'Last) return Natural;
2401 -- Repeatedly match something simple, report how many
2402 -- It only matches on things of length 1.
2403 -- Starting from Input_Pos, it matches at most Max CURLY.
2404
2405 function Try (Pos : Positive) return Boolean;
2406 -- Try to match at specific point
2407
2408 function Match (IP : Pointer) return Boolean;
2409 -- This is the main matching routine. Conceptually the strategy
2410 -- is simple: check to see whether the current node matches,
2411 -- call self recursively to see whether the rest matches,
2412 -- and then act accordingly.
2413 --
2414 -- In practice Match makes some effort to avoid recursion, in
2415 -- particular by going through "ordinary" nodes (that don't
2416 -- need to know whether the rest of the match failed) by
2417 -- using a loop instead of recursion.
2418 -- Why is the above comment part of the spec rather than body ???
2419
2420 function Match_Whilem return Boolean;
2421 -- Return True if a WHILEM matches the Current_Curly
2422
2423 function Recurse_Match (IP : Pointer; From : Natural) return Boolean;
2424 pragma Inline (Recurse_Match);
2425 -- Calls Match recursively. It saves and restores the parenthesis
2426 -- status and location in the input stream correctly, so that
2427 -- backtracking is possible
2428
2429 function Match_Simple_Operator
2430 (Op : Opcode;
2431 Scan : Pointer;
2432 Next : Pointer;
2433 Greedy : Boolean) return Boolean;
2434 -- Return True it the simple operator (possibly non-greedy) matches
2435
2436 Dump_Indent : Integer := -1;
2437 procedure Dump_Current (Scan : Pointer; Prefix : Boolean := True);
2438 procedure Dump_Error (Msg : String);
2439 -- Debug: print the current context
2440
2441 pragma Inline (Index);
2442 pragma Inline (Repeat);
2443
2444 -- These are two complex functions, but used only once
2445
2446 pragma Inline (Match_Whilem);
2447 pragma Inline (Match_Simple_Operator);
2448
2449 -----------
2450 -- Index --
2451 -----------
2452
2453 function Index (Start : Positive; C : Character) return Natural is
2454 begin
2455 for J in Start .. Last_In_Data loop
2456 if Data (J) = C then
2457 return J;
2458 end if;
2459 end loop;
2460
2461 return 0;
2462 end Index;
2463
2464 -------------------
2465 -- Recurse_Match --
2466 -------------------
2467
2468 function Recurse_Match (IP : Pointer; From : Natural) return Boolean is
2469 L : constant Natural := Last_Paren;
2470 Tmp_F : constant Match_Array :=
2471 Matches_Full (From + 1 .. Matches_Full'Last);
2472 Start : constant Natural_Array :=
2473 Matches_Tmp (From + 1 .. Matches_Tmp'Last);
2474 Input : constant Natural := Input_Pos;
2475
2476 Dump_Indent_Save : constant Integer := Dump_Indent;
2477
2478 begin
2479 if Match (IP) then
2480 return True;
2481 end if;
2482
2483 Last_Paren := L;
2484 Matches_Full (Tmp_F'Range) := Tmp_F;
2485 Matches_Tmp (Start'Range) := Start;
2486 Input_Pos := Input;
2487 Dump_Indent := Dump_Indent_Save;
2488 return False;
2489 end Recurse_Match;
2490
2491 ------------------
2492 -- Dump_Current --
2493 ------------------
2494
2495 procedure Dump_Current (Scan : Pointer; Prefix : Boolean := True) is
2496 Length : constant := 10;
2497 Pos : constant String := Integer'Image (Input_Pos);
2498
2499 begin
2500 if Prefix then
2501 Put ((1 .. 5 - Pos'Length => ' '));
2502 Put (Pos & " <"
2503 & Data (Input_Pos
2504 .. Integer'Min (Last_In_Data, Input_Pos + Length - 1)));
2505 Put ((1 .. Length - 1 - Last_In_Data + Input_Pos => ' '));
2506 Put ("> |");
2507
2508 else
2509 Put (" ");
2510 end if;
2511
2512 Dump_Operation (Program, Scan, Indent => Dump_Indent);
2513 end Dump_Current;
2514
2515 ----------------
2516 -- Dump_Error --
2517 ----------------
2518
2519 procedure Dump_Error (Msg : String) is
2520 begin
2521 Put (" | ");
2522 Put ((1 .. Dump_Indent * 2 => ' '));
2523 Put_Line (Msg);
2524 end Dump_Error;
2525
2526 -----------
2527 -- Match --
2528 -----------
2529
2530 function Match (IP : Pointer) return Boolean is
2531 Scan : Pointer := IP;
2532 Next : Pointer;
2533 Op : Opcode;
2534 Result : Boolean;
2535
2536 begin
2537 Dump_Indent := Dump_Indent + 1;
2538
2539 State_Machine :
2540 loop
2541 pragma Assert (Scan /= 0);
2542
2543 -- Determine current opcode and count its usage in debug mode
2544
2545 Op := Opcode'Val (Character'Pos (Program (Scan)));
2546
2547 -- Calculate offset of next instruction. Second character is most
2548 -- significant in Program_Data.
2549
2550 Next := Get_Next (Program, Scan);
2551
2552 if Debug then
2553 Dump_Current (Scan);
2554 end if;
2555
2556 case Op is
2557 when EOP =>
2558 Dump_Indent := Dump_Indent - 1;
2559 return True; -- Success !
2560
2561 when BRANCH =>
2562 if Program (Next) /= BRANCH then
2563 Next := Operand (Scan); -- No choice, avoid recursion
2564
2565 else
2566 loop
2567 if Recurse_Match (Operand (Scan), 0) then
2568 Dump_Indent := Dump_Indent - 1;
2569 return True;
2570 end if;
2571
2572 Scan := Get_Next (Program, Scan);
2573 exit when Scan = 0 or else Program (Scan) /= BRANCH;
2574 end loop;
2575
2576 exit State_Machine;
2577 end if;
2578
2579 when NOTHING =>
2580 null;
2581
2582 when BOL =>
2583 exit State_Machine when Input_Pos /= BOL_Pos
2584 and then ((Self.Flags and Multiple_Lines) = 0
2585 or else Data (Input_Pos - 1) /= ASCII.LF);
2586
2587 when MBOL =>
2588 exit State_Machine when Input_Pos /= BOL_Pos
2589 and then Data (Input_Pos - 1) /= ASCII.LF;
2590
2591 when SBOL =>
2592 exit State_Machine when Input_Pos /= BOL_Pos;
2593
2594 when EOL =>
2595 exit State_Machine when Input_Pos <= Data'Last
2596 and then ((Self.Flags and Multiple_Lines) = 0
2597 or else Data (Input_Pos) /= ASCII.LF);
2598
2599 when MEOL =>
2600 exit State_Machine when Input_Pos <= Data'Last
2601 and then Data (Input_Pos) /= ASCII.LF;
2602
2603 when SEOL =>
2604 exit State_Machine when Input_Pos <= Data'Last;
2605
2606 when BOUND | NBOUND =>
2607
2608 -- Was last char in word ?
2609
2610 declare
2611 N : Boolean := False;
2612 Ln : Boolean := False;
2613
2614 begin
2615 if Input_Pos /= First_In_Data then
2616 N := Is_Alnum (Data (Input_Pos - 1));
2617 end if;
2618
2619 Ln :=
2620 (if Input_Pos > Last_In_Data
2621 then False
2622 else Is_Alnum (Data (Input_Pos)));
2623
2624 if Op = BOUND then
2625 if N = Ln then
2626 exit State_Machine;
2627 end if;
2628 else
2629 if N /= Ln then
2630 exit State_Machine;
2631 end if;
2632 end if;
2633 end;
2634
2635 when SPACE =>
2636 exit State_Machine when Input_Pos > Last_In_Data
2637 or else not Is_White_Space (Data (Input_Pos));
2638 Input_Pos := Input_Pos + 1;
2639
2640 when NSPACE =>
2641 exit State_Machine when Input_Pos > Last_In_Data
2642 or else Is_White_Space (Data (Input_Pos));
2643 Input_Pos := Input_Pos + 1;
2644
2645 when DIGIT =>
2646 exit State_Machine when Input_Pos > Last_In_Data
2647 or else not Is_Digit (Data (Input_Pos));
2648 Input_Pos := Input_Pos + 1;
2649
2650 when NDIGIT =>
2651 exit State_Machine when Input_Pos > Last_In_Data
2652 or else Is_Digit (Data (Input_Pos));
2653 Input_Pos := Input_Pos + 1;
2654
2655 when ALNUM =>
2656 exit State_Machine when Input_Pos > Last_In_Data
2657 or else not Is_Alnum (Data (Input_Pos));
2658 Input_Pos := Input_Pos + 1;
2659
2660 when NALNUM =>
2661 exit State_Machine when Input_Pos > Last_In_Data
2662 or else Is_Alnum (Data (Input_Pos));
2663 Input_Pos := Input_Pos + 1;
2664
2665 when ANY =>
2666 exit State_Machine when Input_Pos > Last_In_Data
2667 or else Data (Input_Pos) = ASCII.LF;
2668 Input_Pos := Input_Pos + 1;
2669
2670 when SANY =>
2671 exit State_Machine when Input_Pos > Last_In_Data;
2672 Input_Pos := Input_Pos + 1;
2673
2674 when EXACT =>
2675 declare
2676 Opnd : Pointer := String_Operand (Scan);
2677 Current : Positive := Input_Pos;
2678 Last : constant Pointer :=
2679 Opnd + String_Length (Program, Scan);
2680
2681 begin
2682 while Opnd <= Last loop
2683 exit State_Machine when Current > Last_In_Data
2684 or else Program (Opnd) /= Data (Current);
2685 Current := Current + 1;
2686 Opnd := Opnd + 1;
2687 end loop;
2688
2689 Input_Pos := Current;
2690 end;
2691
2692 when EXACTF =>
2693 declare
2694 Opnd : Pointer := String_Operand (Scan);
2695 Current : Positive := Input_Pos;
2696
2697 Last : constant Pointer :=
2698 Opnd + String_Length (Program, Scan);
2699
2700 begin
2701 while Opnd <= Last loop
2702 exit State_Machine when Current > Last_In_Data
2703 or else Program (Opnd) /= To_Lower (Data (Current));
2704 Current := Current + 1;
2705 Opnd := Opnd + 1;
2706 end loop;
2707
2708 Input_Pos := Current;
2709 end;
2710
2711 when ANYOF =>
2712 declare
2713 Bitmap : Character_Class;
2714 begin
2715 Bitmap_Operand (Program, Scan, Bitmap);
2716 exit State_Machine when Input_Pos > Last_In_Data
2717 or else not Get_From_Class (Bitmap, Data (Input_Pos));
2718 Input_Pos := Input_Pos + 1;
2719 end;
2720
2721 when OPEN =>
2722 declare
2723 No : constant Natural :=
2724 Character'Pos (Program (Operand (Scan)));
2725 begin
2726 Matches_Tmp (No) := Input_Pos;
2727 end;
2728
2729 when CLOSE =>
2730 declare
2731 No : constant Natural :=
2732 Character'Pos (Program (Operand (Scan)));
2733
2734 begin
2735 Matches_Full (No) := (Matches_Tmp (No), Input_Pos - 1);
2736
2737 if Last_Paren < No then
2738 Last_Paren := No;
2739 end if;
2740 end;
2741
2742 when REFF =>
2743 declare
2744 No : constant Natural :=
2745 Character'Pos (Program (Operand (Scan)));
2746
2747 Data_Pos : Natural;
2748
2749 begin
2750 -- If we haven't seen that parenthesis yet
2751
2752 if Last_Paren < No then
2753 Dump_Indent := Dump_Indent - 1;
2754
2755 if Debug then
2756 Dump_Error ("REFF: No match, backtracking");
2757 end if;
2758
2759 return False;
2760 end if;
2761
2762 Data_Pos := Matches_Full (No).First;
2763
2764 while Data_Pos <= Matches_Full (No).Last loop
2765 if Input_Pos > Last_In_Data
2766 or else Data (Input_Pos) /= Data (Data_Pos)
2767 then
2768 Dump_Indent := Dump_Indent - 1;
2769
2770 if Debug then
2771 Dump_Error ("REFF: No match, backtracking");
2772 end if;
2773
2774 return False;
2775 end if;
2776
2777 Input_Pos := Input_Pos + 1;
2778 Data_Pos := Data_Pos + 1;
2779 end loop;
2780 end;
2781
2782 when MINMOD =>
2783 Greedy := False;
2784
2785 when STAR | PLUS | CURLY =>
2786 declare
2787 Greed : constant Boolean := Greedy;
2788 begin
2789 Greedy := True;
2790 Result := Match_Simple_Operator (Op, Scan, Next, Greed);
2791 Dump_Indent := Dump_Indent - 1;
2792 return Result;
2793 end;
2794
2795 when CURLYX =>
2796
2797 -- Looking at something like:
2798
2799 -- 1: CURLYX {n,m} (->4)
2800 -- 2: code for complex thing (->3)
2801 -- 3: WHILEM (->0)
2802 -- 4: NOTHING
2803
2804 declare
2805 Min : constant Natural :=
2806 Read_Natural (Program, Scan + Next_Pointer_Bytes);
2807 Max : constant Natural :=
2808 Read_Natural
2809 (Program, Scan + Next_Pointer_Bytes + 2);
2810 Cc : aliased Current_Curly_Record;
2811
2812 Has_Match : Boolean;
2813
2814 begin
2815 Cc := (Paren_Floor => Last_Paren,
2816 Cur => -1,
2817 Min => Min,
2818 Max => Max,
2819 Greedy => Greedy,
2820 Scan => Scan + 7,
2821 Next => Next,
2822 Lastloc => 0,
2823 Old_Cc => Current_Curly);
2824 Greedy := True;
2825 Current_Curly := Cc'Unchecked_Access;
2826
2827 Has_Match := Match (Next - Next_Pointer_Bytes);
2828
2829 -- Start on the WHILEM
2830
2831 Current_Curly := Cc.Old_Cc;
2832 Dump_Indent := Dump_Indent - 1;
2833
2834 if not Has_Match then
2835 if Debug then
2836 Dump_Error ("CURLYX failed...");
2837 end if;
2838 end if;
2839
2840 return Has_Match;
2841 end;
2842
2843 when WHILEM =>
2844 Result := Match_Whilem;
2845 Dump_Indent := Dump_Indent - 1;
2846
2847 if Debug and then not Result then
2848 Dump_Error ("WHILEM: no match, backtracking");
2849 end if;
2850
2851 return Result;
2852 end case;
2853
2854 Scan := Next;
2855 end loop State_Machine;
2856
2857 if Debug then
2858 Dump_Error ("failed...");
2859 Dump_Indent := Dump_Indent - 1;
2860 end if;
2861
2862 -- If we get here, there is no match. For successful matches when EOP
2863 -- is the terminating point.
2864
2865 return False;
2866 end Match;
2867
2868 ---------------------------
2869 -- Match_Simple_Operator --
2870 ---------------------------
2871
2872 function Match_Simple_Operator
2873 (Op : Opcode;
2874 Scan : Pointer;
2875 Next : Pointer;
2876 Greedy : Boolean) return Boolean
2877 is
2878 Next_Char : Character := ASCII.NUL;
2879 Next_Char_Known : Boolean := False;
2880 No : Integer; -- Can be negative
2881 Min : Natural;
2882 Max : Natural := Natural'Last;
2883 Operand_Code : Pointer;
2884 Old : Natural;
2885 Last_Pos : Natural;
2886 Save : constant Natural := Input_Pos;
2887
2888 begin
2889 -- Lookahead to avoid useless match attempts when we know what
2890 -- character comes next.
2891
2892 if Program (Next) = EXACT then
2893 Next_Char := Program (String_Operand (Next));
2894 Next_Char_Known := True;
2895 end if;
2896
2897 -- Find the minimal and maximal values for the operator
2898
2899 case Op is
2900 when STAR =>
2901 Min := 0;
2902 Operand_Code := Operand (Scan);
2903
2904 when PLUS =>
2905 Min := 1;
2906 Operand_Code := Operand (Scan);
2907
2908 when others =>
2909 Min := Read_Natural (Program, Scan + Next_Pointer_Bytes);
2910 Max := Read_Natural (Program, Scan + Next_Pointer_Bytes + 2);
2911 Operand_Code := Scan + 7;
2912 end case;
2913
2914 if Debug then
2915 Dump_Current (Operand_Code, Prefix => False);
2916 end if;
2917
2918 -- Non greedy operators
2919
2920 if not Greedy then
2921
2922 -- Test we can repeat at least Min times
2923
2924 if Min /= 0 then
2925 No := Repeat (Operand_Code, Min);
2926
2927 if No < Min then
2928 if Debug then
2929 Dump_Error ("failed... matched" & No'Img & " times");
2930 end if;
2931
2932 return False;
2933 end if;
2934 end if;
2935
2936 Old := Input_Pos;
2937
2938 -- Find the place where 'next' could work
2939
2940 if Next_Char_Known then
2941
2942 -- Last position to check
2943
2944 if Max = Natural'Last then
2945 Last_Pos := Last_In_Data;
2946 else
2947 Last_Pos := Input_Pos + Max;
2948
2949 if Last_Pos > Last_In_Data then
2950 Last_Pos := Last_In_Data;
2951 end if;
2952 end if;
2953
2954 -- Look for the first possible opportunity
2955
2956 if Debug then
2957 Dump_Error ("Next_Char must be " & Next_Char);
2958 end if;
2959
2960 loop
2961 -- Find the next possible position
2962
2963 while Input_Pos <= Last_Pos
2964 and then Data (Input_Pos) /= Next_Char
2965 loop
2966 Input_Pos := Input_Pos + 1;
2967 end loop;
2968
2969 if Input_Pos > Last_Pos then
2970 return False;
2971 end if;
2972
2973 -- Check that we still match if we stop at the position we
2974 -- just found.
2975
2976 declare
2977 Num : constant Natural := Input_Pos - Old;
2978
2979 begin
2980 Input_Pos := Old;
2981
2982 if Debug then
2983 Dump_Error ("Would we still match at that position?");
2984 end if;
2985
2986 if Repeat (Operand_Code, Num) < Num then
2987 return False;
2988 end if;
2989 end;
2990
2991 -- Input_Pos now points to the new position
2992
2993 if Match (Get_Next (Program, Scan)) then
2994 return True;
2995 end if;
2996
2997 Old := Input_Pos;
2998 Input_Pos := Input_Pos + 1;
2999 end loop;
3000
3001 -- We do not know what the next character is
3002
3003 else
3004 while Max >= Min loop
3005 if Debug then
3006 Dump_Error ("Non-greedy repeat, N=" & Min'Img);
3007 Dump_Error ("Do we still match Next if we stop here?");
3008 end if;
3009
3010 -- If the next character matches
3011
3012 if Recurse_Match (Next, 1) then
3013 return True;
3014 end if;
3015
3016 Input_Pos := Save + Min;
3017
3018 -- Could not or did not match -- move forward
3019
3020 if Repeat (Operand_Code, 1) /= 0 then
3021 Min := Min + 1;
3022 else
3023 if Debug then
3024 Dump_Error ("Non-greedy repeat failed...");
3025 end if;
3026
3027 return False;
3028 end if;
3029 end loop;
3030 end if;
3031
3032 return False;
3033
3034 -- Greedy operators
3035
3036 else
3037 No := Repeat (Operand_Code, Max);
3038
3039 if Debug and then No < Min then
3040 Dump_Error ("failed... matched" & No'Img & " times");
3041 end if;
3042
3043 -- ??? Perl has some special code here in case the next
3044 -- instruction is of type EOL, since $ and \Z can match before
3045 -- *and* after newline at the end.
3046
3047 -- ??? Perl has some special code here in case (paren) is True
3048
3049 -- Else, if we don't have any parenthesis
3050
3051 while No >= Min loop
3052 if not Next_Char_Known
3053 or else (Input_Pos <= Last_In_Data
3054 and then Data (Input_Pos) = Next_Char)
3055 then
3056 if Match (Next) then
3057 return True;
3058 end if;
3059 end if;
3060
3061 -- Could not or did not work, we back up
3062
3063 No := No - 1;
3064 Input_Pos := Save + No;
3065 end loop;
3066
3067 return False;
3068 end if;
3069 end Match_Simple_Operator;
3070
3071 ------------------
3072 -- Match_Whilem --
3073 ------------------
3074
3075 -- This is really hard to understand, because after we match what we
3076 -- are trying to match, we must make sure the rest of the REx is going
3077 -- to match for sure, and to do that we have to go back UP the parse
3078 -- tree by recursing ever deeper. And if it fails, we have to reset
3079 -- our parent's current state that we can try again after backing off.
3080
3081 function Match_Whilem return Boolean is
3082 Cc : constant Current_Curly_Access := Current_Curly;
3083
3084 N : constant Natural := Cc.Cur + 1;
3085 Ln : Natural := 0;
3086
3087 Lastloc : constant Natural := Cc.Lastloc;
3088 -- Detection of 0-len
3089
3090 begin
3091 -- If degenerate scan matches "", assume scan done
3092
3093 if Input_Pos = Cc.Lastloc
3094 and then N >= Cc.Min
3095 then
3096 -- Temporarily restore the old context, and check that we
3097 -- match was comes after CURLYX.
3098
3099 Current_Curly := Cc.Old_Cc;
3100
3101 if Current_Curly /= null then
3102 Ln := Current_Curly.Cur;
3103 end if;
3104
3105 if Match (Cc.Next) then
3106 return True;
3107 end if;
3108
3109 if Current_Curly /= null then
3110 Current_Curly.Cur := Ln;
3111 end if;
3112
3113 Current_Curly := Cc;
3114 return False;
3115 end if;
3116
3117 -- First, just match a string of min scans
3118
3119 if N < Cc.Min then
3120 Cc.Cur := N;
3121 Cc.Lastloc := Input_Pos;
3122
3123 if Debug then
3124 Dump_Error
3125 ("Tests that we match at least" & Cc.Min'Img & " N=" & N'Img);
3126 end if;
3127
3128 if Match (Cc.Scan) then
3129 return True;
3130 end if;
3131
3132 Cc.Cur := N - 1;
3133 Cc.Lastloc := Lastloc;
3134
3135 if Debug then
3136 Dump_Error ("failed...");
3137 end if;
3138
3139 return False;
3140 end if;
3141
3142 -- Prefer next over scan for minimal matching
3143
3144 if not Cc.Greedy then
3145 Current_Curly := Cc.Old_Cc;
3146
3147 if Current_Curly /= null then
3148 Ln := Current_Curly.Cur;
3149 end if;
3150
3151 if Recurse_Match (Cc.Next, Cc.Paren_Floor) then
3152 return True;
3153 end if;
3154
3155 if Current_Curly /= null then
3156 Current_Curly.Cur := Ln;
3157 end if;
3158
3159 Current_Curly := Cc;
3160
3161 -- Maximum greed exceeded ?
3162
3163 if N >= Cc.Max then
3164 if Debug then
3165 Dump_Error ("failed...");
3166 end if;
3167 return False;
3168 end if;
3169
3170 -- Try scanning more and see if it helps
3171 Cc.Cur := N;
3172 Cc.Lastloc := Input_Pos;
3173
3174 if Debug then
3175 Dump_Error ("Next failed, what about Current?");
3176 end if;
3177
3178 if Recurse_Match (Cc.Scan, Cc.Paren_Floor) then
3179 return True;
3180 end if;
3181
3182 Cc.Cur := N - 1;
3183 Cc.Lastloc := Lastloc;
3184 return False;
3185 end if;
3186
3187 -- Prefer scan over next for maximal matching
3188
3189 if N < Cc.Max then -- more greed allowed ?
3190 Cc.Cur := N;
3191 Cc.Lastloc := Input_Pos;
3192
3193 if Debug then
3194 Dump_Error ("Recurse at current position");
3195 end if;
3196
3197 if Recurse_Match (Cc.Scan, Cc.Paren_Floor) then
3198 return True;
3199 end if;
3200 end if;
3201
3202 -- Failed deeper matches of scan, so see if this one works
3203
3204 Current_Curly := Cc.Old_Cc;
3205
3206 if Current_Curly /= null then
3207 Ln := Current_Curly.Cur;
3208 end if;
3209
3210 if Debug then
3211 Dump_Error ("Failed matching for later positions");
3212 end if;
3213
3214 if Match (Cc.Next) then
3215 return True;
3216 end if;
3217
3218 if Current_Curly /= null then
3219 Current_Curly.Cur := Ln;
3220 end if;
3221
3222 Current_Curly := Cc;
3223 Cc.Cur := N - 1;
3224 Cc.Lastloc := Lastloc;
3225
3226 if Debug then
3227 Dump_Error ("failed...");
3228 end if;
3229
3230 return False;
3231 end Match_Whilem;
3232
3233 ------------
3234 -- Repeat --
3235 ------------
3236
3237 function Repeat
3238 (IP : Pointer;
3239 Max : Natural := Natural'Last) return Natural
3240 is
3241 Scan : Natural := Input_Pos;
3242 Last : Natural;
3243 Op : constant Opcode := Opcode'Val (Character'Pos (Program (IP)));
3244 Count : Natural;
3245 C : Character;
3246 Is_First : Boolean := True;
3247 Bitmap : Character_Class;
3248
3249 begin
3250 if Max = Natural'Last or else Scan + Max - 1 > Last_In_Data then
3251 Last := Last_In_Data;
3252 else
3253 Last := Scan + Max - 1;
3254 end if;
3255
3256 case Op is
3257 when ANY =>
3258 while Scan <= Last
3259 and then Data (Scan) /= ASCII.LF
3260 loop
3261 Scan := Scan + 1;
3262 end loop;
3263
3264 when SANY =>
3265 Scan := Last + 1;
3266
3267 when EXACT =>
3268
3269 -- The string has only one character if Repeat was called
3270
3271 C := Program (String_Operand (IP));
3272 while Scan <= Last
3273 and then C = Data (Scan)
3274 loop
3275 Scan := Scan + 1;
3276 end loop;
3277
3278 when EXACTF =>
3279
3280 -- The string has only one character if Repeat was called
3281
3282 C := Program (String_Operand (IP));
3283 while Scan <= Last
3284 and then To_Lower (C) = Data (Scan)
3285 loop
3286 Scan := Scan + 1;
3287 end loop;
3288
3289 when ANYOF =>
3290 if Is_First then
3291 Bitmap_Operand (Program, IP, Bitmap);
3292 Is_First := False;
3293 end if;
3294
3295 while Scan <= Last
3296 and then Get_From_Class (Bitmap, Data (Scan))
3297 loop
3298 Scan := Scan + 1;
3299 end loop;
3300
3301 when ALNUM =>
3302 while Scan <= Last
3303 and then Is_Alnum (Data (Scan))
3304 loop
3305 Scan := Scan + 1;
3306 end loop;
3307
3308 when NALNUM =>
3309 while Scan <= Last
3310 and then not Is_Alnum (Data (Scan))
3311 loop
3312 Scan := Scan + 1;
3313 end loop;
3314
3315 when SPACE =>
3316 while Scan <= Last
3317 and then Is_White_Space (Data (Scan))
3318 loop
3319 Scan := Scan + 1;
3320 end loop;
3321
3322 when NSPACE =>
3323 while Scan <= Last
3324 and then not Is_White_Space (Data (Scan))
3325 loop
3326 Scan := Scan + 1;
3327 end loop;
3328
3329 when DIGIT =>
3330 while Scan <= Last
3331 and then Is_Digit (Data (Scan))
3332 loop
3333 Scan := Scan + 1;
3334 end loop;
3335
3336 when NDIGIT =>
3337 while Scan <= Last
3338 and then not Is_Digit (Data (Scan))
3339 loop
3340 Scan := Scan + 1;
3341 end loop;
3342
3343 when others =>
3344 raise Program_Error;
3345 end case;
3346
3347 Count := Scan - Input_Pos;
3348 Input_Pos := Scan;
3349 return Count;
3350 end Repeat;
3351
3352 ---------
3353 -- Try --
3354 ---------
3355
3356 function Try (Pos : Positive) return Boolean is
3357 begin
3358 Input_Pos := Pos;
3359 Last_Paren := 0;
3360 Matches_Full := (others => No_Match);
3361
3362 if Match (Program_First) then
3363 Matches_Full (0) := (Pos, Input_Pos - 1);
3364 return True;
3365 end if;
3366
3367 return False;
3368 end Try;
3369
3370 -- Start of processing for Match
3371
3372 begin
3373 -- Do we have the regexp Never_Match?
3374
3375 if Self.Size = 0 then
3376 Matches := (others => No_Match);
3377 return;
3378 end if;
3379
3380 -- If there is a "must appear" string, look for it
3381
3382 if Self.Must_Have_Length > 0 then
3383 declare
3384 First : constant Character := Program (Self.Must_Have);
3385 Must_First : constant Pointer := Self.Must_Have;
3386 Must_Last : constant Pointer :=
3387 Must_First + Pointer (Self.Must_Have_Length - 1);
3388 Next_Try : Natural := Index (First_In_Data, First);
3389
3390 begin
3391 while Next_Try /= 0
3392 and then Data (Next_Try .. Next_Try + Self.Must_Have_Length - 1)
3393 = String (Program (Must_First .. Must_Last))
3394 loop
3395 Next_Try := Index (Next_Try + 1, First);
3396 end loop;
3397
3398 if Next_Try = 0 then
3399 Matches := (others => No_Match);
3400 return; -- Not present
3401 end if;
3402 end;
3403 end if;
3404
3405 -- Mark beginning of line for ^
3406
3407 BOL_Pos := Data'First;
3408
3409 -- Simplest case first: an anchored match need be tried only once
3410
3411 if Self.Anchored and then (Self.Flags and Multiple_Lines) = 0 then
3412 Matched := Try (First_In_Data);
3413
3414 elsif Self.Anchored then
3415 declare
3416 Next_Try : Natural := First_In_Data;
3417 begin
3418 -- Test the first position in the buffer
3419 Matched := Try (Next_Try);
3420
3421 -- Else only test after newlines
3422
3423 if not Matched then
3424 while Next_Try <= Last_In_Data loop
3425 while Next_Try <= Last_In_Data
3426 and then Data (Next_Try) /= ASCII.LF
3427 loop
3428 Next_Try := Next_Try + 1;
3429 end loop;
3430
3431 Next_Try := Next_Try + 1;
3432
3433 if Next_Try <= Last_In_Data then
3434 Matched := Try (Next_Try);
3435 exit when Matched;
3436 end if;
3437 end loop;
3438 end if;
3439 end;
3440
3441 elsif Self.First /= ASCII.NUL then
3442 -- We know what char it must start with
3443
3444 declare
3445 Next_Try : Natural := Index (First_In_Data, Self.First);
3446
3447 begin
3448 while Next_Try /= 0 loop
3449 Matched := Try (Next_Try);
3450 exit when Matched;
3451 Next_Try := Index (Next_Try + 1, Self.First);
3452 end loop;
3453 end;
3454
3455 else
3456 -- Messy cases: try all locations (including for the empty string)
3457
3458 Matched := Try (First_In_Data);
3459
3460 if not Matched then
3461 for S in First_In_Data + 1 .. Last_In_Data loop
3462 Matched := Try (S);
3463 exit when Matched;
3464 end loop;
3465 end if;
3466 end if;
3467
3468 -- Matched has its value
3469
3470 for J in Last_Paren + 1 .. Matches'Last loop
3471 Matches_Full (J) := No_Match;
3472 end loop;
3473
3474 Matches := Matches_Full (Matches'Range);
3475 end Match;
3476
3477 -----------
3478 -- Match --
3479 -----------
3480
3481 function Match
3482 (Self : Pattern_Matcher;
3483 Data : String;
3484 Data_First : Integer := -1;
3485 Data_Last : Positive := Positive'Last) return Natural
3486 is
3487 Matches : Match_Array (0 .. 0);
3488
3489 begin
3490 Match (Self, Data, Matches, Data_First, Data_Last);
3491 if Matches (0) = No_Match then
3492 return Data'First - 1;
3493 else
3494 return Matches (0).First;
3495 end if;
3496 end Match;
3497
3498 function Match
3499 (Self : Pattern_Matcher;
3500 Data : String;
3501 Data_First : Integer := -1;
3502 Data_Last : Positive := Positive'Last) return Boolean
3503 is
3504 Matches : Match_Array (0 .. 0);
3505
3506 begin
3507 Match (Self, Data, Matches, Data_First, Data_Last);
3508 return Matches (0).First >= Data'First;
3509 end Match;
3510
3511 procedure Match
3512 (Expression : String;
3513 Data : String;
3514 Matches : out Match_Array;
3515 Size : Program_Size := Auto_Size;
3516 Data_First : Integer := -1;
3517 Data_Last : Positive := Positive'Last)
3518 is
3519 PM : Pattern_Matcher (Size);
3520 Finalize_Size : Program_Size;
3521 pragma Unreferenced (Finalize_Size);
3522 begin
3523 if Size = 0 then
3524 Match (Compile (Expression), Data, Matches, Data_First, Data_Last);
3525 else
3526 Compile (PM, Expression, Finalize_Size);
3527 Match (PM, Data, Matches, Data_First, Data_Last);
3528 end if;
3529 end Match;
3530
3531 -----------
3532 -- Match --
3533 -----------
3534
3535 function Match
3536 (Expression : String;
3537 Data : String;
3538 Size : Program_Size := Auto_Size;
3539 Data_First : Integer := -1;
3540 Data_Last : Positive := Positive'Last) return Natural
3541 is
3542 PM : Pattern_Matcher (Size);
3543 Final_Size : Program_Size;
3544 pragma Unreferenced (Final_Size);
3545 begin
3546 if Size = 0 then
3547 return Match (Compile (Expression), Data, Data_First, Data_Last);
3548 else
3549 Compile (PM, Expression, Final_Size);
3550 return Match (PM, Data, Data_First, Data_Last);
3551 end if;
3552 end Match;
3553
3554 -----------
3555 -- Match --
3556 -----------
3557
3558 function Match
3559 (Expression : String;
3560 Data : String;
3561 Size : Program_Size := Auto_Size;
3562 Data_First : Integer := -1;
3563 Data_Last : Positive := Positive'Last) return Boolean
3564 is
3565 Matches : Match_Array (0 .. 0);
3566 PM : Pattern_Matcher (Size);
3567 Final_Size : Program_Size;
3568 pragma Unreferenced (Final_Size);
3569 begin
3570 if Size = 0 then
3571 Match (Compile (Expression), Data, Matches, Data_First, Data_Last);
3572 else
3573 Compile (PM, Expression, Final_Size);
3574 Match (PM, Data, Matches, Data_First, Data_Last);
3575 end if;
3576
3577 return Matches (0).First >= Data'First;
3578 end Match;
3579
3580 -------------
3581 -- Operand --
3582 -------------
3583
3584 function Operand (P : Pointer) return Pointer is
3585 begin
3586 return P + Next_Pointer_Bytes;
3587 end Operand;
3588
3589 --------------
3590 -- Optimize --
3591 --------------
3592
3593 procedure Optimize (Self : in out Pattern_Matcher) is
3594 Scan : Pointer;
3595 Program : Program_Data renames Self.Program;
3596
3597 begin
3598 -- Start with safe defaults (no optimization):
3599 -- * No known first character of match
3600 -- * Does not necessarily start at beginning of line
3601 -- * No string known that has to appear in data
3602
3603 Self.First := ASCII.NUL;
3604 Self.Anchored := False;
3605 Self.Must_Have := Program'Last + 1;
3606 Self.Must_Have_Length := 0;
3607
3608 Scan := Program_First; -- First instruction (can be anything)
3609
3610 if Program (Scan) = EXACT then
3611 Self.First := Program (String_Operand (Scan));
3612
3613 elsif Program (Scan) = BOL
3614 or else Program (Scan) = SBOL
3615 or else Program (Scan) = MBOL
3616 then
3617 Self.Anchored := True;
3618 end if;
3619 end Optimize;
3620
3621 -----------------
3622 -- Paren_Count --
3623 -----------------
3624
3625 function Paren_Count (Regexp : Pattern_Matcher) return Match_Count is
3626 begin
3627 return Regexp.Paren_Count;
3628 end Paren_Count;
3629
3630 -----------
3631 -- Quote --
3632 -----------
3633
3634 function Quote (Str : String) return String is
3635 S : String (1 .. Str'Length * 2);
3636 Last : Natural := 0;
3637
3638 begin
3639 for J in Str'Range loop
3640 case Str (J) is
3641 when '^' | '$' | '|' | '*' | '+' | '?' | '{' |
3642 '}' | '[' | ']' | '(' | ')' | '\' | '.' =>
3643
3644 S (Last + 1) := '\';
3645 S (Last + 2) := Str (J);
3646 Last := Last + 2;
3647
3648 when others =>
3649 S (Last + 1) := Str (J);
3650 Last := Last + 1;
3651 end case;
3652 end loop;
3653
3654 return S (1 .. Last);
3655 end Quote;
3656
3657 ------------------
3658 -- Read_Natural --
3659 ------------------
3660
3661 function Read_Natural
3662 (Program : Program_Data;
3663 IP : Pointer) return Natural
3664 is
3665 begin
3666 return Character'Pos (Program (IP)) +
3667 256 * Character'Pos (Program (IP + 1));
3668 end Read_Natural;
3669
3670 -----------------
3671 -- Reset_Class --
3672 -----------------
3673
3674 procedure Reset_Class (Bitmap : out Character_Class) is
3675 begin
3676 Bitmap := (others => 0);
3677 end Reset_Class;
3678
3679 ------------------
3680 -- Set_In_Class --
3681 ------------------
3682
3683 procedure Set_In_Class
3684 (Bitmap : in out Character_Class;
3685 C : Character)
3686 is
3687 Value : constant Class_Byte := Character'Pos (C);
3688 begin
3689 Bitmap (Value / 8) := Bitmap (Value / 8)
3690 or Bit_Conversion (Value mod 8);
3691 end Set_In_Class;
3692
3693 -------------------
3694 -- String_Length --
3695 -------------------
3696
3697 function String_Length
3698 (Program : Program_Data;
3699 P : Pointer) return Program_Size
3700 is
3701 begin
3702 pragma Assert (Program (P) = EXACT or else Program (P) = EXACTF);
3703 return Character'Pos (Program (P + Next_Pointer_Bytes));
3704 end String_Length;
3705
3706 --------------------
3707 -- String_Operand --
3708 --------------------
3709
3710 function String_Operand (P : Pointer) return Pointer is
3711 begin
3712 return P + 4;
3713 end String_Operand;
3714
3715 end System.Regpat;
GCC graphite test results