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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 | -- -- | |
| 598c3446 | 9 | -- $Revision$ |
| 38cbfe40 RK |
10 | -- -- |
| 11 | -- Copyright (C) 1986 by University of Toronto. -- | |
| 12 | -- Copyright (C) 1996-2001 Ada Core Technologies, Inc. -- | |
| 13 | -- -- | |
| 14 | -- GNAT is free software; you can redistribute it and/or modify it under -- | |
| 15 | -- terms of the GNU General Public License as published by the Free Soft- -- | |
| 16 | -- ware Foundation; either version 2, or (at your option) any later ver- -- | |
| 17 | -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- | |
| 18 | -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- | |
| 19 | -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- | |
| 20 | -- for more details. You should have received a copy of the GNU General -- | |
| 21 | -- Public License distributed with GNAT; see file COPYING. If not, write -- | |
| 22 | -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- | |
| 23 | -- MA 02111-1307, USA. -- | |
| 24 | -- -- | |
| 25 | -- As a special exception, if other files instantiate generics from this -- | |
| 26 | -- unit, or you link this unit with other files to produce an executable, -- | |
| 27 | -- this unit does not by itself cause the resulting executable to be -- | |
| 28 | -- covered by the GNU General Public License. This exception does not -- | |
| 29 | -- however invalidate any other reasons why the executable file might be -- | |
| 30 | -- covered by the GNU Public License. -- | |
| 31 | -- -- | |
| 32 | -- GNAT is maintained by Ada Core Technologies Inc (http://www.gnat.com). -- | |
| 33 | -- -- | |
| 34 | ------------------------------------------------------------------------------ | |
| 35 | ||
| 36 | -- This is an altered Ada 95 version of the original V8 style regular | |
| 37 | -- expression library written in C by Henry Spencer. Apart from the | |
| 38 | -- translation to Ada, the interface has been considerably changed to | |
| 39 | -- use the Ada String type instead of C-style nul-terminated strings. | |
| 40 | ||
| 41 | -- Beware that some of this code is subtly aware of the way operator | |
| 42 | -- precedence is structured in regular expressions. Serious changes in | |
| 43 | -- regular-expression syntax might require a total rethink. | |
| 44 | ||
| 45 | with System.IO; use System.IO; | |
| 46 | with Ada.Characters.Handling; use Ada.Characters.Handling; | |
| 47 | with Unchecked_Conversion; | |
| 48 | ||
| 49 | package body GNAT.Regpat is | |
| 50 | ||
| 51 | MAGIC : constant Character := Character'Val (10#0234#); | |
| 52 | -- The first byte of the regexp internal "program" is actually | |
| 53 | -- this magic number; the start node begins in the second byte. | |
| 54 | -- | |
| 55 | -- This is used to make sure that a regular expression was correctly | |
| 56 | -- compiled. | |
| 57 | ||
| 58 | ---------------------------- | |
| 59 | -- Implementation details -- | |
| 60 | ---------------------------- | |
| 61 | ||
| 62 | -- This is essentially a linear encoding of a nondeterministic | |
| 63 | -- finite-state machine, also known as syntax charts or | |
| 64 | -- "railroad normal form" in parsing technology. | |
| 65 | ||
| 66 | -- Each node is an opcode plus a "next" pointer, possibly plus an | |
| 67 | -- operand. "Next" pointers of all nodes except BRANCH implement | |
| 68 | -- concatenation; a "next" pointer with a BRANCH on both ends of it | |
| 69 | -- is connecting two alternatives. | |
| 70 | ||
| 71 | -- The operand of some types of node is a literal string; for others, | |
| 72 | -- it is a node leading into a sub-FSM. In particular, the operand of | |
| 73 | -- a BRANCH node is the first node of the branch. | |
| 74 | -- (NB this is *not* a tree structure: the tail of the branch connects | |
| 75 | -- to the thing following the set of BRANCHes). | |
| 76 | ||
| 77 | -- You can see the exact byte-compiled version by using the Dump | |
| 78 | -- subprogram. However, here are a few examples: | |
| 79 | ||
| 80 | -- (a|b): 1 : MAGIC | |
| 81 | -- 2 : BRANCH (next at 10) | |
| 82 | -- 5 : EXACT (next at 18) operand=a | |
| 83 | -- 10 : BRANCH (next at 18) | |
| 84 | -- 13 : EXACT (next at 18) operand=b | |
| 85 | -- 18 : EOP (next at 0) | |
| 86 | -- | |
| 87 | -- (ab)*: 1 : MAGIC | |
| 88 | -- 2 : CURLYX (next at 26) { 0, 32767} | |
| 89 | -- 9 : OPEN 1 (next at 13) | |
| 90 | -- 13 : EXACT (next at 19) operand=ab | |
| 91 | -- 19 : CLOSE 1 (next at 23) | |
| 92 | -- 23 : WHILEM (next at 0) | |
| 93 | -- 26 : NOTHING (next at 29) | |
| 94 | -- 29 : EOP (next at 0) | |
| 95 | ||
| 96 | -- The opcodes are: | |
| 97 | ||
| 98 | type Opcode is | |
| 99 | ||
| 100 | -- Name Operand? Meaning | |
| 101 | ||
| 102 | (EOP, -- no End of program | |
| 103 | MINMOD, -- no Next operator is not greedy | |
| 104 | ||
| 105 | -- Classes of characters | |
| 106 | ||
| 107 | ANY, -- no Match any one character except newline | |
| 108 | SANY, -- no Match any character, including new line | |
| 109 | ANYOF, -- class Match any character in this class | |
| 110 | EXACT, -- str Match this string exactly | |
| 111 | EXACTF, -- str Match this string (case-folding is one) | |
| 112 | NOTHING, -- no Match empty string | |
| 113 | SPACE, -- no Match any whitespace character | |
| 114 | NSPACE, -- no Match any non-whitespace character | |
| 115 | DIGIT, -- no Match any numeric character | |
| 116 | NDIGIT, -- no Match any non-numeric character | |
| 117 | ALNUM, -- no Match any alphanumeric character | |
| 118 | NALNUM, -- no Match any non-alphanumeric character | |
| 119 | ||
| 120 | -- Branches | |
| 121 | ||
| 122 | BRANCH, -- node Match this alternative, or the next | |
| 123 | ||
| 124 | -- Simple loops (when the following node is one character in length) | |
| 125 | ||
| 126 | STAR, -- node Match this simple thing 0 or more times | |
| 127 | PLUS, -- node Match this simple thing 1 or more times | |
| 128 | CURLY, -- 2num node Match this simple thing between n and m times. | |
| 129 | ||
| 130 | -- Complex loops | |
| 131 | ||
| 132 | CURLYX, -- 2num node Match this complex thing {n,m} times | |
| 133 | -- The nums are coded on two characters each. | |
| 134 | ||
| 135 | WHILEM, -- no Do curly processing and see if rest matches | |
| 136 | ||
| 137 | -- Matches after or before a word | |
| 138 | ||
| 139 | BOL, -- no Match "" at beginning of line | |
| 140 | MBOL, -- no Same, assuming mutiline (match after \n) | |
| 141 | SBOL, -- no Same, assuming single line (don't match at \n) | |
| 142 | EOL, -- no Match "" at end of line | |
| 143 | MEOL, -- no Same, assuming mutiline (match before \n) | |
| 144 | SEOL, -- no Same, assuming single line (don't match at \n) | |
| 145 | ||
| 146 | BOUND, -- no Match "" at any word boundary | |
| 147 | NBOUND, -- no Match "" at any word non-boundary | |
| 148 | ||
| 149 | -- Parenthesis groups handling | |
| 150 | ||
| 151 | REFF, -- num Match some already matched string, folded | |
| 152 | OPEN, -- num Mark this point in input as start of #n | |
| 153 | CLOSE); -- num Analogous to OPEN | |
| 154 | ||
| 155 | for Opcode'Size use 8; | |
| 156 | ||
| 157 | -- Opcode notes: | |
| 158 | ||
| 159 | -- BRANCH | |
| 160 | -- The set of branches constituting a single choice are hooked | |
| 161 | -- together with their "next" pointers, since precedence prevents | |
| 162 | -- anything being concatenated to any individual branch. The | |
| 163 | -- "next" pointer of the last BRANCH in a choice points to the | |
| 164 | -- thing following the whole choice. This is also where the | |
| 165 | -- final "next" pointer of each individual branch points; each | |
| 166 | -- branch starts with the operand node of a BRANCH node. | |
| 167 | ||
| 168 | -- STAR,PLUS | |
| 169 | -- '?', and complex '*' and '+', are implemented with CURLYX. | |
| 170 | -- branches. Simple cases (one character per match) are implemented with | |
| 171 | -- STAR and PLUS for speed and to minimize recursive plunges. | |
| 172 | ||
| 173 | -- OPEN,CLOSE | |
| 174 | -- ...are numbered at compile time. | |
| 175 | ||
| 176 | -- EXACT, EXACTF | |
| 177 | -- There are in fact two arguments, the first one is the length (minus | |
| 178 | -- one of the string argument), coded on one character, the second | |
| 179 | -- argument is the string itself, coded on length + 1 characters. | |
| 180 | ||
| 181 | -- A node is one char of opcode followed by two chars of "next" pointer. | |
| 182 | -- "Next" pointers are stored as two 8-bit pieces, high order first. The | |
| 183 | -- value is a positive offset from the opcode of the node containing it. | |
| 184 | -- An operand, if any, simply follows the node. (Note that much of the | |
| 185 | -- code generation knows about this implicit relationship.) | |
| 186 | ||
| 187 | -- Using two bytes for the "next" pointer is vast overkill for most | |
| 188 | -- things, but allows patterns to get big without disasters. | |
| 189 | ||
| 190 | ----------------------- | |
| 191 | -- Character classes -- | |
| 192 | ----------------------- | |
| 193 | -- This is the implementation for character classes ([...]) in the | |
| 194 | -- syntax for regular expressions. Each character (0..256) has an | |
| 195 | -- entry into the table. This makes for a very fast matching | |
| 196 | -- algorithm. | |
| 197 | ||
| 198 | type Class_Byte is mod 256; | |
| 199 | type Character_Class is array (Class_Byte range 0 .. 31) of Class_Byte; | |
| 200 | ||
| 201 | type Bit_Conversion_Array is array (Class_Byte range 0 .. 7) of Class_Byte; | |
| 202 | Bit_Conversion : constant Bit_Conversion_Array := | |
| 203 | (1, 2, 4, 8, 16, 32, 64, 128); | |
| 204 | ||
| 205 | type Std_Class is (ANYOF_NONE, | |
| 206 | ANYOF_ALNUM, -- Alphanumeric class [a-zA-Z0-9] | |
| 207 | ANYOF_NALNUM, | |
| 208 | ANYOF_SPACE, -- Space class [ \t\n\r\f] | |
| 209 | ANYOF_NSPACE, | |
| 210 | ANYOF_DIGIT, -- Digit class [0-9] | |
| 211 | ANYOF_NDIGIT, | |
| 212 | ANYOF_ALNUMC, -- Alphanumeric class [a-zA-Z0-9] | |
| 213 | ANYOF_NALNUMC, | |
| 214 | ANYOF_ALPHA, -- Alpha class [a-zA-Z] | |
| 215 | ANYOF_NALPHA, | |
| 216 | ANYOF_ASCII, -- Ascii class (7 bits) 0..127 | |
| 217 | ANYOF_NASCII, | |
| 218 | ANYOF_CNTRL, -- Control class | |
| 219 | ANYOF_NCNTRL, | |
| 220 | ANYOF_GRAPH, -- Graphic class | |
| 221 | ANYOF_NGRAPH, | |
| 222 | ANYOF_LOWER, -- Lower case class [a-z] | |
| 223 | ANYOF_NLOWER, | |
| 224 | ANYOF_PRINT, -- printable class | |
| 225 | ANYOF_NPRINT, | |
| 226 | ANYOF_PUNCT, -- | |
| 227 | ANYOF_NPUNCT, | |
| 228 | ANYOF_UPPER, -- Upper case class [A-Z] | |
| 229 | ANYOF_NUPPER, | |
| 230 | ANYOF_XDIGIT, -- Hexadecimal digit | |
| 231 | ANYOF_NXDIGIT | |
| 232 | ); | |
| 233 | ||
| 234 | procedure Set_In_Class | |
| 235 | (Bitmap : in out Character_Class; | |
| 236 | C : Character); | |
| 237 | -- Set the entry to True for C in the class Bitmap. | |
| 238 | ||
| 239 | function Get_From_Class | |
| 240 | (Bitmap : Character_Class; | |
| 241 | C : Character) | |
| 242 | return Boolean; | |
| 243 | -- Return True if the entry is set for C in the class Bitmap. | |
| 244 | ||
| 245 | procedure Reset_Class (Bitmap : in out Character_Class); | |
| 246 | -- Clear all the entries in the class Bitmap. | |
| 247 | ||
| 248 | pragma Inline_Always (Set_In_Class); | |
| 249 | pragma Inline_Always (Get_From_Class); | |
| 250 | pragma Inline_Always (Reset_Class); | |
| 251 | ||
| 252 | ----------------------- | |
| 253 | -- Local Subprograms -- | |
| 254 | ----------------------- | |
| 255 | ||
| 256 | function "+" (Left : Opcode; Right : Integer) return Opcode; | |
| 257 | function "-" (Left : Opcode; Right : Opcode) return Integer; | |
| 258 | function "=" (Left : Character; Right : Opcode) return Boolean; | |
| 259 | ||
| 260 | function Is_Alnum (C : Character) return Boolean; | |
| 261 | -- Return True if C is an alphanum character or an underscore ('_') | |
| 262 | ||
| 263 | function Is_Space (C : Character) return Boolean; | |
| 264 | -- Return True if C is a whitespace character | |
| 265 | ||
| 266 | function Is_Printable (C : Character) return Boolean; | |
| 267 | -- Return True if C is a printable character | |
| 268 | ||
| 269 | function Operand (P : Pointer) return Pointer; | |
| 270 | -- Return a pointer to the first operand of the node at P | |
| 271 | ||
| 272 | function String_Length | |
| 273 | (Program : Program_Data; | |
| 274 | P : Pointer) | |
| 275 | return Program_Size; | |
| 276 | -- Return the length of the string argument of the node at P | |
| 277 | ||
| 278 | function String_Operand (P : Pointer) return Pointer; | |
| 279 | -- Return a pointer to the string argument of the node at P | |
| 280 | ||
| 281 | procedure Bitmap_Operand | |
| 282 | (Program : Program_Data; | |
| 283 | P : Pointer; | |
| 284 | Op : out Character_Class); | |
| 285 | -- Return a pointer to the string argument of the node at P | |
| 286 | ||
| 287 | function Get_Next_Offset | |
| 288 | (Program : Program_Data; | |
| 289 | IP : Pointer) | |
| 290 | return Pointer; | |
| 291 | -- Get the offset field of a node. Used by Get_Next. | |
| 292 | ||
| 293 | function Get_Next | |
| 294 | (Program : Program_Data; | |
| 295 | IP : Pointer) | |
| 296 | return Pointer; | |
| 297 | -- Dig the next instruction pointer out of a node | |
| 298 | ||
| 299 | procedure Optimize (Self : in out Pattern_Matcher); | |
| 300 | -- Optimize a Pattern_Matcher by noting certain special cases | |
| 301 | ||
| 302 | function Read_Natural | |
| 303 | (Program : Program_Data; | |
| 304 | IP : Pointer) | |
| 305 | return Natural; | |
| 306 | -- Return the 2-byte natural coded at position IP. | |
| 307 | ||
| 308 | -- All of the subprograms above are tiny and should be inlined | |
| 309 | ||
| 310 | pragma Inline ("+"); | |
| 311 | pragma Inline ("-"); | |
| 312 | pragma Inline ("="); | |
| 313 | pragma Inline (Is_Alnum); | |
| 314 | pragma Inline (Is_Space); | |
| 315 | pragma Inline (Get_Next); | |
| 316 | pragma Inline (Get_Next_Offset); | |
| 317 | pragma Inline (Operand); | |
| 318 | pragma Inline (Read_Natural); | |
| 319 | pragma Inline (String_Length); | |
| 320 | pragma Inline (String_Operand); | |
| 321 | ||
| 322 | type Expression_Flags is record | |
| 323 | Has_Width, -- Known never to match null string | |
| 324 | Simple, -- Simple enough to be STAR/PLUS operand | |
| 325 | SP_Start : Boolean; -- Starts with * or + | |
| 326 | end record; | |
| 327 | ||
| 328 | Worst_Expression : constant Expression_Flags := (others => False); | |
| 329 | -- Worst case | |
| 330 | ||
| 331 | --------- | |
| 332 | -- "+" -- | |
| 333 | --------- | |
| 334 | ||
| 335 | function "+" (Left : Opcode; Right : Integer) return Opcode is | |
| 336 | begin | |
| 337 | return Opcode'Val (Opcode'Pos (Left) + Right); | |
| 338 | end "+"; | |
| 339 | ||
| 340 | --------- | |
| 341 | -- "-" -- | |
| 342 | --------- | |
| 343 | ||
| 344 | function "-" (Left : Opcode; Right : Opcode) return Integer is | |
| 345 | begin | |
| 346 | return Opcode'Pos (Left) - Opcode'Pos (Right); | |
| 347 | end "-"; | |
| 348 | ||
| 349 | --------- | |
| 350 | -- "=" -- | |
| 351 | --------- | |
| 352 | ||
| 353 | function "=" (Left : Character; Right : Opcode) return Boolean is | |
| 354 | begin | |
| 355 | return Character'Pos (Left) = Opcode'Pos (Right); | |
| 356 | end "="; | |
| 357 | ||
| 358 | -------------------- | |
| 359 | -- Bitmap_Operand -- | |
| 360 | -------------------- | |
| 361 | ||
| 362 | procedure Bitmap_Operand | |
| 363 | (Program : Program_Data; | |
| 364 | P : Pointer; | |
| 365 | Op : out Character_Class) | |
| 366 | is | |
| 367 | function Convert is new Unchecked_Conversion | |
| 368 | (Program_Data, Character_Class); | |
| 369 | ||
| 370 | begin | |
| 371 | Op (0 .. 31) := Convert (Program (P + 3 .. P + 34)); | |
| 372 | end Bitmap_Operand; | |
| 373 | ||
| 374 | ------------- | |
| 375 | -- Compile -- | |
| 376 | ------------- | |
| 377 | ||
| 378 | procedure Compile | |
| 379 | (Matcher : out Pattern_Matcher; | |
| 380 | Expression : String; | |
| 381 | Final_Code_Size : out Program_Size; | |
| 382 | Flags : Regexp_Flags := No_Flags) | |
| 383 | is | |
| 384 | -- We can't allocate space until we know how big the compiled form | |
| 385 | -- will be, but we can't compile it (and thus know how big it is) | |
| 386 | -- until we've got a place to put the code. So we cheat: we compile | |
| 387 | -- it twice, once with code generation turned off and size counting | |
| 388 | -- turned on, and once "for real". | |
| 389 | ||
| 390 | -- This also means that we don't allocate space until we are sure | |
| 391 | -- that the thing really will compile successfully, and we never | |
| 392 | -- have to move the code and thus invalidate pointers into it. | |
| 393 | ||
| 394 | -- Beware that the optimization-preparation code in here knows | |
| 395 | -- about some of the structure of the compiled regexp. | |
| 396 | ||
| 397 | PM : Pattern_Matcher renames Matcher; | |
| 398 | Program : Program_Data renames PM.Program; | |
| 399 | ||
| 400 | Emit_Code : constant Boolean := PM.Size > 0; | |
| 401 | Emit_Ptr : Pointer := Program_First; | |
| 402 | ||
| 403 | Parse_Pos : Natural := Expression'First; -- Input-scan pointer | |
| 404 | Parse_End : Natural := Expression'Last; | |
| 405 | ||
| 406 | ---------------------------- | |
| 407 | -- Subprograms for Create -- | |
| 408 | ---------------------------- | |
| 409 | ||
| 410 | procedure Emit (B : Character); | |
| 411 | -- Output the Character to the Program. | |
| 412 | -- If code-generation is disables, simply increments the program | |
| 413 | -- counter. | |
| 414 | ||
| 415 | function Emit_Node (Op : Opcode) return Pointer; | |
| 416 | -- If code-generation is enabled, Emit_Node outputs the | |
| 417 | -- opcode and reserves space for a pointer to the next node. | |
| 418 | -- Return value is the location of new opcode, ie old Emit_Ptr. | |
| 419 | ||
| 420 | procedure Emit_Natural (IP : Pointer; N : Natural); | |
| 421 | -- Split N on two characters at position IP. | |
| 422 | ||
| 423 | procedure Emit_Class (Bitmap : Character_Class); | |
| 424 | -- Emits a character class. | |
| 425 | ||
| 426 | procedure Case_Emit (C : Character); | |
| 427 | -- Emit C, after converting is to lower-case if the regular | |
| 428 | -- expression is case insensitive. | |
| 429 | ||
| 430 | procedure Parse | |
| 431 | (Parenthesized : Boolean; | |
| 432 | Flags : in out Expression_Flags; | |
| 433 | IP : out Pointer); | |
| 434 | -- Parse regular expression, i.e. main body or parenthesized thing | |
| 435 | -- Caller must absorb opening parenthesis. | |
| 436 | ||
| 437 | procedure Parse_Branch | |
| 438 | (Flags : in out Expression_Flags; | |
| 439 | First : Boolean; | |
| 440 | IP : out Pointer); | |
| 441 | -- Implements the concatenation operator and handles '|' | |
| 442 | -- First should be true if this is the first item of the alternative. | |
| 443 | ||
| 444 | procedure Parse_Piece | |
| 445 | (Expr_Flags : in out Expression_Flags; IP : out Pointer); | |
| 446 | -- Parse something followed by possible [*+?] | |
| 447 | ||
| 448 | procedure Parse_Atom | |
| 449 | (Expr_Flags : in out Expression_Flags; IP : out Pointer); | |
| 450 | -- Parse_Atom is the lowest level parse procedure. | |
| 451 | -- Optimization: gobbles an entire sequence of ordinary characters | |
| 452 | -- so that it can turn them into a single node, which is smaller to | |
| 453 | -- store and faster to run. Backslashed characters are exceptions, | |
| 454 | -- each becoming a separate node; the code is simpler that way and | |
| 455 | -- it's not worth fixing. | |
| 456 | ||
| 457 | procedure Insert_Operator | |
| 458 | (Op : Opcode; | |
| 459 | Operand : Pointer; | |
| 460 | Greedy : Boolean := True); | |
| 461 | -- Insert_Operator inserts an operator in front of an | |
| 462 | -- already-emitted operand and relocates the operand. | |
| 463 | -- This applies to PLUS and STAR. | |
| 464 | -- If Minmod is True, then the operator is non-greedy. | |
| 465 | ||
| 466 | procedure Insert_Curly_Operator | |
| 467 | (Op : Opcode; | |
| 468 | Min : Natural; | |
| 469 | Max : Natural; | |
| 470 | Operand : Pointer; | |
| 471 | Greedy : Boolean := True); | |
| 472 | -- Insert an operator for CURLY ({Min}, {Min,} or {Min,Max}). | |
| 473 | -- If Minmod is True, then the operator is non-greedy. | |
| 474 | ||
| 475 | procedure Link_Tail (P, Val : Pointer); | |
| 476 | -- Link_Tail sets the next-pointer at the end of a node chain | |
| 477 | ||
| 478 | procedure Link_Operand_Tail (P, Val : Pointer); | |
| 479 | -- Link_Tail on operand of first argument; nop if operandless | |
| 480 | ||
| 481 | function Next_Instruction (P : Pointer) return Pointer; | |
| 482 | -- Dig the "next" pointer out of a node | |
| 483 | ||
| 484 | procedure Fail (M : in String); | |
| 485 | -- Fail with a diagnostic message, if possible | |
| 486 | ||
| 487 | function Is_Curly_Operator (IP : Natural) return Boolean; | |
| 488 | -- Return True if IP is looking at a '{' that is the beginning | |
| 489 | -- of a curly operator, ie it matches {\d+,?\d*} | |
| 490 | ||
| 491 | function Is_Mult (IP : Natural) return Boolean; | |
| 492 | -- Return True if C is a regexp multiplier: '+', '*' or '?' | |
| 493 | ||
| 494 | procedure Get_Curly_Arguments | |
| 495 | (IP : Natural; | |
| 496 | Min : out Natural; | |
| 497 | Max : out Natural; | |
| 498 | Greedy : out Boolean); | |
| 499 | -- Parse the argument list for a curly operator. | |
| 500 | -- It is assumed that IP is indeed pointing at a valid operator. | |
| 501 | ||
| 502 | procedure Parse_Character_Class (IP : out Pointer); | |
| 503 | -- Parse a character class. | |
| 504 | -- The calling subprogram should consume the opening '[' before. | |
| 505 | ||
| 506 | procedure Parse_Literal (Expr_Flags : in out Expression_Flags; | |
| 507 | IP : out Pointer); | |
| 508 | -- Parse_Literal encodes a string of characters | |
| 509 | -- to be matched exactly. | |
| 510 | ||
| 511 | function Parse_Posix_Character_Class return Std_Class; | |
| 512 | -- Parse a posic character class, like [:alpha:] or [:^alpha:]. | |
| 513 | -- The called is suppoed to absorbe the opening [. | |
| 514 | ||
| 515 | pragma Inline_Always (Is_Mult); | |
| 516 | pragma Inline_Always (Emit_Natural); | |
| 517 | pragma Inline_Always (Parse_Character_Class); -- since used only once | |
| 518 | ||
| 519 | --------------- | |
| 520 | -- Case_Emit -- | |
| 521 | --------------- | |
| 522 | ||
| 523 | procedure Case_Emit (C : Character) is | |
| 524 | begin | |
| 525 | if (Flags and Case_Insensitive) /= 0 then | |
| 526 | Emit (To_Lower (C)); | |
| 527 | ||
| 528 | else | |
| 529 | -- Dump current character | |
| 530 | ||
| 531 | Emit (C); | |
| 532 | end if; | |
| 533 | end Case_Emit; | |
| 534 | ||
| 535 | ---------- | |
| 536 | -- Emit -- | |
| 537 | ---------- | |
| 538 | ||
| 539 | procedure Emit (B : Character) is | |
| 540 | begin | |
| 541 | if Emit_Code then | |
| 542 | Program (Emit_Ptr) := B; | |
| 543 | end if; | |
| 544 | ||
| 545 | Emit_Ptr := Emit_Ptr + 1; | |
| 546 | end Emit; | |
| 547 | ||
| 548 | ---------------- | |
| 549 | -- Emit_Class -- | |
| 550 | ---------------- | |
| 551 | ||
| 552 | procedure Emit_Class (Bitmap : Character_Class) is | |
| 553 | subtype Program31 is Program_Data (0 .. 31); | |
| 554 | ||
| 555 | function Convert is new Unchecked_Conversion | |
| 556 | (Character_Class, Program31); | |
| 557 | ||
| 558 | begin | |
| 559 | if Emit_Code then | |
| 560 | Program (Emit_Ptr .. Emit_Ptr + 31) := Convert (Bitmap); | |
| 561 | end if; | |
| 562 | ||
| 563 | Emit_Ptr := Emit_Ptr + 32; | |
| 564 | end Emit_Class; | |
| 565 | ||
| 566 | ------------------ | |
| 567 | -- Emit_Natural -- | |
| 568 | ------------------ | |
| 569 | ||
| 570 | procedure Emit_Natural (IP : Pointer; N : Natural) is | |
| 571 | begin | |
| 572 | if Emit_Code then | |
| 573 | Program (IP + 1) := Character'Val (N / 256); | |
| 574 | Program (IP) := Character'Val (N mod 256); | |
| 575 | end if; | |
| 576 | end Emit_Natural; | |
| 577 | ||
| 578 | --------------- | |
| 579 | -- Emit_Node -- | |
| 580 | --------------- | |
| 581 | ||
| 582 | function Emit_Node (Op : Opcode) return Pointer is | |
| 583 | Result : constant Pointer := Emit_Ptr; | |
| 584 | ||
| 585 | begin | |
| 586 | if Emit_Code then | |
| 587 | Program (Emit_Ptr) := Character'Val (Opcode'Pos (Op)); | |
| 588 | Program (Emit_Ptr + 1) := ASCII.NUL; | |
| 589 | Program (Emit_Ptr + 2) := ASCII.NUL; | |
| 590 | end if; | |
| 591 | ||
| 592 | Emit_Ptr := Emit_Ptr + 3; | |
| 593 | return Result; | |
| 594 | end Emit_Node; | |
| 595 | ||
| 596 | ---------- | |
| 597 | -- Fail -- | |
| 598 | ---------- | |
| 599 | ||
| 600 | procedure Fail (M : in String) is | |
| 601 | begin | |
| 602 | raise Expression_Error; | |
| 603 | end Fail; | |
| 604 | ||
| 605 | ------------------------- | |
| 606 | -- Get_Curly_Arguments -- | |
| 607 | ------------------------- | |
| 608 | ||
| 609 | procedure Get_Curly_Arguments | |
| 610 | (IP : Natural; | |
| 611 | Min : out Natural; | |
| 612 | Max : out Natural; | |
| 613 | Greedy : out Boolean) | |
| 614 | is | |
| 615 | Save_Pos : Natural := Parse_Pos + 1; | |
| 616 | ||
| 617 | begin | |
| 618 | Min := 0; | |
| 619 | Max := Max_Curly_Repeat; | |
| 620 | ||
| 621 | while Expression (Parse_Pos) /= '}' | |
| 622 | and then Expression (Parse_Pos) /= ',' | |
| 623 | loop | |
| 624 | Parse_Pos := Parse_Pos + 1; | |
| 625 | end loop; | |
| 626 | ||
| 627 | Min := Natural'Value (Expression (Save_Pos .. Parse_Pos - 1)); | |
| 628 | ||
| 629 | if Expression (Parse_Pos) = ',' then | |
| 630 | Save_Pos := Parse_Pos + 1; | |
| 631 | while Expression (Parse_Pos) /= '}' loop | |
| 632 | Parse_Pos := Parse_Pos + 1; | |
| 633 | end loop; | |
| 634 | ||
| 635 | if Save_Pos /= Parse_Pos then | |
| 636 | Max := Natural'Value (Expression (Save_Pos .. Parse_Pos - 1)); | |
| 637 | end if; | |
| 638 | ||
| 639 | else | |
| 640 | Max := Min; | |
| 641 | end if; | |
| 642 | ||
| 643 | if Parse_Pos < Expression'Last | |
| 644 | and then Expression (Parse_Pos + 1) = '?' | |
| 645 | then | |
| 646 | Greedy := False; | |
| 647 | Parse_Pos := Parse_Pos + 1; | |
| 648 | ||
| 649 | else | |
| 650 | Greedy := True; | |
| 651 | end if; | |
| 652 | end Get_Curly_Arguments; | |
| 653 | ||
| 654 | --------------------------- | |
| 655 | -- Insert_Curly_Operator -- | |
| 656 | --------------------------- | |
| 657 | ||
| 658 | procedure Insert_Curly_Operator | |
| 659 | (Op : Opcode; | |
| 660 | Min : Natural; | |
| 661 | Max : Natural; | |
| 662 | Operand : Pointer; | |
| 663 | Greedy : Boolean := True) | |
| 664 | is | |
| 665 | Dest : constant Pointer := Emit_Ptr; | |
| 666 | Old : Pointer; | |
| 667 | Size : Pointer := 7; | |
| 668 | ||
| 669 | begin | |
| 670 | -- If the operand is not greedy, insert an extra operand before it | |
| 671 | ||
| 672 | if not Greedy then | |
| 673 | Size := Size + 3; | |
| 674 | end if; | |
| 675 | ||
| 676 | -- Move the operand in the byte-compilation, so that we can insert | |
| 677 | -- the operator before it. | |
| 678 | ||
| 679 | if Emit_Code then | |
| 680 | Program (Operand + Size .. Emit_Ptr + Size) := | |
| 681 | Program (Operand .. Emit_Ptr); | |
| 682 | end if; | |
| 683 | ||
| 684 | -- Insert the operator at the position previously occupied by the | |
| 685 | -- operand. | |
| 686 | ||
| 687 | Emit_Ptr := Operand; | |
| 688 | ||
| 689 | if not Greedy then | |
| 690 | Old := Emit_Node (MINMOD); | |
| 691 | Link_Tail (Old, Old + 3); | |
| 692 | end if; | |
| 693 | ||
| 694 | Old := Emit_Node (Op); | |
| 695 | Emit_Natural (Old + 3, Min); | |
| 696 | Emit_Natural (Old + 5, Max); | |
| 697 | ||
| 698 | Emit_Ptr := Dest + Size; | |
| 699 | end Insert_Curly_Operator; | |
| 700 | ||
| 701 | --------------------- | |
| 702 | -- Insert_Operator -- | |
| 703 | --------------------- | |
| 704 | ||
| 705 | procedure Insert_Operator | |
| 706 | (Op : Opcode; | |
| 707 | Operand : Pointer; | |
| 708 | Greedy : Boolean := True) | |
| 709 | is | |
| 710 | Dest : constant Pointer := Emit_Ptr; | |
| 711 | Old : Pointer; | |
| 712 | Size : Pointer := 3; | |
| 713 | ||
| 714 | begin | |
| 715 | -- If not greedy, we have to emit another opcode first | |
| 716 | ||
| 717 | if not Greedy then | |
| 718 | Size := Size + 3; | |
| 719 | end if; | |
| 720 | ||
| 721 | -- Move the operand in the byte-compilation, so that we can insert | |
| 722 | -- the operator before it. | |
| 723 | ||
| 724 | if Emit_Code then | |
| 725 | Program (Operand + Size .. Emit_Ptr + Size) | |
| 726 | := Program (Operand .. Emit_Ptr); | |
| 727 | end if; | |
| 728 | ||
| 729 | -- Insert the operator at the position previously occupied by the | |
| 730 | -- operand. | |
| 731 | ||
| 732 | Emit_Ptr := Operand; | |
| 733 | ||
| 734 | if not Greedy then | |
| 735 | Old := Emit_Node (MINMOD); | |
| 736 | Link_Tail (Old, Old + 3); | |
| 737 | end if; | |
| 738 | ||
| 739 | Old := Emit_Node (Op); | |
| 740 | Emit_Ptr := Dest + Size; | |
| 741 | end Insert_Operator; | |
| 742 | ||
| 743 | ----------------------- | |
| 744 | -- Is_Curly_Operator -- | |
| 745 | ----------------------- | |
| 746 | ||
| 747 | function Is_Curly_Operator (IP : Natural) return Boolean is | |
| 748 | Scan : Natural := IP; | |
| 749 | ||
| 750 | begin | |
| 751 | if Expression (Scan) /= '{' | |
| 752 | or else Scan + 2 > Expression'Last | |
| 753 | or else not Is_Digit (Expression (Scan + 1)) | |
| 754 | then | |
| 755 | return False; | |
| 756 | end if; | |
| 757 | ||
| 758 | Scan := Scan + 1; | |
| 759 | ||
| 760 | -- The first digit | |
| 761 | ||
| 762 | loop | |
| 763 | Scan := Scan + 1; | |
| 764 | ||
| 765 | if Scan > Expression'Last then | |
| 766 | return False; | |
| 767 | end if; | |
| 768 | ||
| 769 | exit when not Is_Digit (Expression (Scan)); | |
| 770 | end loop; | |
| 771 | ||
| 772 | if Expression (Scan) = ',' then | |
| 773 | loop | |
| 774 | Scan := Scan + 1; | |
| 775 | ||
| 776 | if Scan > Expression'Last then | |
| 777 | return False; | |
| 778 | end if; | |
| 779 | ||
| 780 | exit when not Is_Digit (Expression (Scan)); | |
| 781 | end loop; | |
| 782 | end if; | |
| 783 | ||
| 784 | return Expression (Scan) = '}'; | |
| 785 | end Is_Curly_Operator; | |
| 786 | ||
| 787 | ------------- | |
| 788 | -- Is_Mult -- | |
| 789 | ------------- | |
| 790 | ||
| 791 | function Is_Mult (IP : Natural) return Boolean is | |
| 792 | C : constant Character := Expression (IP); | |
| 793 | ||
| 794 | begin | |
| 795 | return C = '*' | |
| 796 | or else C = '+' | |
| 797 | or else C = '?' | |
| 798 | or else (C = '{' and then Is_Curly_Operator (IP)); | |
| 799 | end Is_Mult; | |
| 800 | ||
| 801 | ----------------------- | |
| 802 | -- Link_Operand_Tail -- | |
| 803 | ----------------------- | |
| 804 | ||
| 805 | procedure Link_Operand_Tail (P, Val : Pointer) is | |
| 806 | begin | |
| 807 | if Emit_Code and then Program (P) = BRANCH then | |
| 808 | Link_Tail (Operand (P), Val); | |
| 809 | end if; | |
| 810 | end Link_Operand_Tail; | |
| 811 | ||
| 812 | --------------- | |
| 813 | -- Link_Tail -- | |
| 814 | --------------- | |
| 815 | ||
| 816 | procedure Link_Tail (P, Val : Pointer) is | |
| 817 | Scan : Pointer; | |
| 818 | Temp : Pointer; | |
| 819 | Offset : Pointer; | |
| 820 | ||
| 821 | begin | |
| 822 | if not Emit_Code then | |
| 823 | return; | |
| 824 | end if; | |
| 825 | ||
| 826 | -- Find last node | |
| 827 | ||
| 828 | Scan := P; | |
| 829 | loop | |
| 830 | Temp := Next_Instruction (Scan); | |
| 831 | exit when Temp = 0; | |
| 832 | Scan := Temp; | |
| 833 | end loop; | |
| 834 | ||
| 835 | Offset := Val - Scan; | |
| 836 | ||
| 837 | Emit_Natural (Scan + 1, Natural (Offset)); | |
| 838 | end Link_Tail; | |
| 839 | ||
| 840 | ---------------------- | |
| 841 | -- Next_Instruction -- | |
| 842 | ---------------------- | |
| 843 | ||
| 844 | function Next_Instruction (P : Pointer) return Pointer is | |
| 845 | Offset : Pointer; | |
| 846 | ||
| 847 | begin | |
| 848 | if not Emit_Code then | |
| 849 | return 0; | |
| 850 | end if; | |
| 851 | ||
| 852 | Offset := Get_Next_Offset (Program, P); | |
| 853 | ||
| 854 | if Offset = 0 then | |
| 855 | return 0; | |
| 856 | end if; | |
| 857 | ||
| 858 | return P + Offset; | |
| 859 | end Next_Instruction; | |
| 860 | ||
| 861 | ----------- | |
| 862 | -- Parse -- | |
| 863 | ----------- | |
| 864 | ||
| 865 | -- Combining parenthesis handling with the base level | |
| 866 | -- of regular expression is a trifle forced, but the | |
| 867 | -- need to tie the tails of the branches to what follows | |
| 868 | -- makes it hard to avoid. | |
| 869 | ||
| 870 | procedure Parse | |
| 871 | (Parenthesized : in Boolean; | |
| 872 | Flags : in out Expression_Flags; | |
| 873 | IP : out Pointer) | |
| 874 | is | |
| 875 | E : String renames Expression; | |
| 876 | Br : Pointer; | |
| 877 | Ender : Pointer; | |
| 878 | Par_No : Natural; | |
| 879 | New_Flags : Expression_Flags; | |
| 880 | Have_Branch : Boolean := False; | |
| 881 | ||
| 882 | begin | |
| 883 | Flags := (Has_Width => True, others => False); -- Tentatively | |
| 884 | ||
| 885 | -- Make an OPEN node, if parenthesized | |
| 886 | ||
| 887 | if Parenthesized then | |
| 888 | if Matcher.Paren_Count > Max_Paren_Count then | |
| 889 | Fail ("too many ()"); | |
| 890 | end if; | |
| 891 | ||
| 892 | Par_No := Matcher.Paren_Count + 1; | |
| 893 | Matcher.Paren_Count := Matcher.Paren_Count + 1; | |
| 894 | IP := Emit_Node (OPEN); | |
| 895 | Emit (Character'Val (Par_No)); | |
| 896 | ||
| 897 | else | |
| 898 | IP := 0; | |
| 899 | end if; | |
| 900 | ||
| 901 | -- Pick up the branches, linking them together | |
| 902 | ||
| 903 | Parse_Branch (New_Flags, True, Br); | |
| 904 | ||
| 905 | if Br = 0 then | |
| 906 | IP := 0; | |
| 907 | return; | |
| 908 | end if; | |
| 909 | ||
| 910 | if Parse_Pos <= Parse_End | |
| 911 | and then E (Parse_Pos) = '|' | |
| 912 | then | |
| 913 | Insert_Operator (BRANCH, Br); | |
| 914 | Have_Branch := True; | |
| 915 | end if; | |
| 916 | ||
| 917 | if IP /= 0 then | |
| 918 | Link_Tail (IP, Br); -- OPEN -> first | |
| 919 | else | |
| 920 | IP := Br; | |
| 921 | end if; | |
| 922 | ||
| 923 | if not New_Flags.Has_Width then | |
| 924 | Flags.Has_Width := False; | |
| 925 | end if; | |
| 926 | ||
| 927 | Flags.SP_Start := Flags.SP_Start or New_Flags.SP_Start; | |
| 928 | ||
| 929 | while Parse_Pos <= Parse_End | |
| 930 | and then (E (Parse_Pos) = '|') | |
| 931 | loop | |
| 932 | Parse_Pos := Parse_Pos + 1; | |
| 933 | Parse_Branch (New_Flags, False, Br); | |
| 934 | ||
| 935 | if Br = 0 then | |
| 936 | IP := 0; | |
| 937 | return; | |
| 938 | end if; | |
| 939 | ||
| 940 | Link_Tail (IP, Br); -- BRANCH -> BRANCH | |
| 941 | ||
| 942 | if not New_Flags.Has_Width then | |
| 943 | Flags.Has_Width := False; | |
| 944 | end if; | |
| 945 | ||
| 946 | Flags.SP_Start := Flags.SP_Start or New_Flags.SP_Start; | |
| 947 | end loop; | |
| 948 | ||
| 949 | -- Make a closing node, and hook it on the end | |
| 950 | ||
| 951 | if Parenthesized then | |
| 952 | Ender := Emit_Node (CLOSE); | |
| 953 | Emit (Character'Val (Par_No)); | |
| 954 | else | |
| 955 | Ender := Emit_Node (EOP); | |
| 956 | end if; | |
| 957 | ||
| 958 | Link_Tail (IP, Ender); | |
| 959 | ||
| 960 | if Have_Branch then | |
| 961 | ||
| 962 | -- Hook the tails of the branches to the closing node | |
| 963 | ||
| 964 | Br := IP; | |
| 965 | loop | |
| 966 | exit when Br = 0; | |
| 967 | Link_Operand_Tail (Br, Ender); | |
| 968 | Br := Next_Instruction (Br); | |
| 969 | end loop; | |
| 970 | end if; | |
| 971 | ||
| 972 | -- Check for proper termination | |
| 973 | ||
| 974 | if Parenthesized then | |
| 975 | if Parse_Pos > Parse_End or else E (Parse_Pos) /= ')' then | |
| 976 | Fail ("unmatched ()"); | |
| 977 | end if; | |
| 978 | ||
| 979 | Parse_Pos := Parse_Pos + 1; | |
| 980 | ||
| 981 | elsif Parse_Pos <= Parse_End then | |
| 982 | if E (Parse_Pos) = ')' then | |
| 983 | Fail ("unmatched ()"); | |
| 984 | else | |
| 985 | Fail ("junk on end"); -- "Can't happen" | |
| 986 | end if; | |
| 987 | end if; | |
| 988 | end Parse; | |
| 989 | ||
| 990 | ---------------- | |
| 991 | -- Parse_Atom -- | |
| 992 | ---------------- | |
| 993 | ||
| 994 | procedure Parse_Atom | |
| 995 | (Expr_Flags : in out Expression_Flags; | |
| 996 | IP : out Pointer) | |
| 997 | is | |
| 998 | C : Character; | |
| 999 | ||
| 1000 | begin | |
| 1001 | -- Tentatively set worst expression case | |
| 1002 | ||
| 1003 | Expr_Flags := Worst_Expression; | |
| 1004 | ||
| 1005 | C := Expression (Parse_Pos); | |
| 1006 | Parse_Pos := Parse_Pos + 1; | |
| 1007 | ||
| 1008 | case (C) is | |
| 1009 | when '^' => | |
| 1010 | if (Flags and Multiple_Lines) /= 0 then | |
| 1011 | IP := Emit_Node (MBOL); | |
| 1012 | elsif (Flags and Single_Line) /= 0 then | |
| 1013 | IP := Emit_Node (SBOL); | |
| 1014 | else | |
| 1015 | IP := Emit_Node (BOL); | |
| 1016 | end if; | |
| 1017 | ||
| 1018 | when '$' => | |
| 1019 | if (Flags and Multiple_Lines) /= 0 then | |
| 1020 | IP := Emit_Node (MEOL); | |
| 1021 | elsif (Flags and Single_Line) /= 0 then | |
| 1022 | IP := Emit_Node (SEOL); | |
| 1023 | else | |
| 1024 | IP := Emit_Node (EOL); | |
| 1025 | end if; | |
| 1026 | ||
| 1027 | when '.' => | |
| 1028 | if (Flags and Single_Line) /= 0 then | |
| 1029 | IP := Emit_Node (SANY); | |
| 1030 | else | |
| 1031 | IP := Emit_Node (ANY); | |
| 1032 | end if; | |
| 1033 | Expr_Flags.Has_Width := True; | |
| 1034 | Expr_Flags.Simple := True; | |
| 1035 | ||
| 1036 | when '[' => | |
| 1037 | Parse_Character_Class (IP); | |
| 1038 | Expr_Flags.Has_Width := True; | |
| 1039 | Expr_Flags.Simple := True; | |
| 1040 | ||
| 1041 | when '(' => | |
| 1042 | declare | |
| 1043 | New_Flags : Expression_Flags; | |
| 1044 | ||
| 1045 | begin | |
| 1046 | Parse (True, New_Flags, IP); | |
| 1047 | ||
| 1048 | if IP = 0 then | |
| 1049 | return; | |
| 1050 | end if; | |
| 1051 | ||
| 1052 | Expr_Flags.Has_Width := | |
| 1053 | Expr_Flags.Has_Width or New_Flags.Has_Width; | |
| 1054 | Expr_Flags.SP_Start := | |
| 1055 | Expr_Flags.SP_Start or New_Flags.SP_Start; | |
| 1056 | end; | |
| 1057 | ||
| 1058 | when '|' | ASCII.LF | ')' => | |
| 1059 | Fail ("internal urp"); -- Supposed to be caught earlier | |
| 1060 | ||
| 1061 | when '?' | '+' | '*' | '{' => | |
| 1062 | Fail ("?+*{ follows nothing"); | |
| 1063 | ||
| 1064 | when '\' => | |
| 1065 | if Parse_Pos > Parse_End then | |
| 1066 | Fail ("trailing \"); | |
| 1067 | end if; | |
| 1068 | ||
| 1069 | Parse_Pos := Parse_Pos + 1; | |
| 1070 | ||
| 1071 | case Expression (Parse_Pos - 1) is | |
| 1072 | when 'b' => | |
| 1073 | IP := Emit_Node (BOUND); | |
| 1074 | ||
| 1075 | when 'B' => | |
| 1076 | IP := Emit_Node (NBOUND); | |
| 1077 | ||
| 1078 | when 's' => | |
| 1079 | IP := Emit_Node (SPACE); | |
| 1080 | Expr_Flags.Simple := True; | |
| 1081 | Expr_Flags.Has_Width := True; | |
| 1082 | ||
| 1083 | when 'S' => | |
| 1084 | IP := Emit_Node (NSPACE); | |
| 1085 | Expr_Flags.Simple := True; | |
| 1086 | Expr_Flags.Has_Width := True; | |
| 1087 | ||
| 1088 | when 'd' => | |
| 1089 | IP := Emit_Node (DIGIT); | |
| 1090 | Expr_Flags.Simple := True; | |
| 1091 | Expr_Flags.Has_Width := True; | |
| 1092 | ||
| 1093 | when 'D' => | |
| 1094 | IP := Emit_Node (NDIGIT); | |
| 1095 | Expr_Flags.Simple := True; | |
| 1096 | Expr_Flags.Has_Width := True; | |
| 1097 | ||
| 1098 | when 'w' => | |
| 1099 | IP := Emit_Node (ALNUM); | |
| 1100 | Expr_Flags.Simple := True; | |
| 1101 | Expr_Flags.Has_Width := True; | |
| 1102 | ||
| 1103 | when 'W' => | |
| 1104 | IP := Emit_Node (NALNUM); | |
| 1105 | Expr_Flags.Simple := True; | |
| 1106 | Expr_Flags.Has_Width := True; | |
| 1107 | ||
| 1108 | when 'A' => | |
| 1109 | IP := Emit_Node (SBOL); | |
| 1110 | ||
| 1111 | when 'G' => | |
| 1112 | IP := Emit_Node (SEOL); | |
| 1113 | ||
| 1114 | when '0' .. '9' => | |
| 1115 | IP := Emit_Node (REFF); | |
| 1116 | ||
| 1117 | declare | |
| 1118 | Save : Natural := Parse_Pos - 1; | |
| 1119 | ||
| 1120 | begin | |
| 1121 | while Parse_Pos <= Expression'Last | |
| 1122 | and then Is_Digit (Expression (Parse_Pos)) | |
| 1123 | loop | |
| 1124 | Parse_Pos := Parse_Pos + 1; | |
| 1125 | end loop; | |
| 1126 | ||
| 1127 | Emit (Character'Val (Natural'Value | |
| 1128 | (Expression (Save .. Parse_Pos - 1)))); | |
| 1129 | end; | |
| 1130 | ||
| 1131 | when others => | |
| 1132 | Parse_Pos := Parse_Pos - 1; | |
| 1133 | Parse_Literal (Expr_Flags, IP); | |
| 1134 | end case; | |
| 1135 | ||
| 1136 | when others => Parse_Literal (Expr_Flags, IP); | |
| 1137 | end case; | |
| 1138 | end Parse_Atom; | |
| 1139 | ||
| 1140 | ------------------ | |
| 1141 | -- Parse_Branch -- | |
| 1142 | ------------------ | |
| 1143 | ||
| 1144 | procedure Parse_Branch | |
| 1145 | (Flags : in out Expression_Flags; | |
| 1146 | First : Boolean; | |
| 1147 | IP : out Pointer) | |
| 1148 | is | |
| 1149 | E : String renames Expression; | |
| 1150 | Chain : Pointer; | |
| 1151 | Last : Pointer; | |
| 1152 | New_Flags : Expression_Flags; | |
| 1153 | Dummy : Pointer; | |
| 1154 | ||
| 1155 | begin | |
| 1156 | Flags := Worst_Expression; -- Tentatively | |
| 1157 | ||
| 1158 | if First then | |
| 1159 | IP := Emit_Ptr; | |
| 1160 | else | |
| 1161 | IP := Emit_Node (BRANCH); | |
| 1162 | end if; | |
| 1163 | ||
| 1164 | Chain := 0; | |
| 1165 | ||
| 1166 | while Parse_Pos <= Parse_End | |
| 1167 | and then E (Parse_Pos) /= ')' | |
| 1168 | and then E (Parse_Pos) /= ASCII.LF | |
| 1169 | and then E (Parse_Pos) /= '|' | |
| 1170 | loop | |
| 1171 | Parse_Piece (New_Flags, Last); | |
| 1172 | ||
| 1173 | if Last = 0 then | |
| 1174 | IP := 0; | |
| 1175 | return; | |
| 1176 | end if; | |
| 1177 | ||
| 1178 | Flags.Has_Width := Flags.Has_Width or New_Flags.Has_Width; | |
| 1179 | ||
| 1180 | if Chain = 0 then -- First piece | |
| 1181 | Flags.SP_Start := Flags.SP_Start or New_Flags.SP_Start; | |
| 1182 | else | |
| 1183 | Link_Tail (Chain, Last); | |
| 1184 | end if; | |
| 1185 | ||
| 1186 | Chain := Last; | |
| 1187 | end loop; | |
| 1188 | ||
| 1189 | if Chain = 0 then -- Loop ran zero CURLY | |
| 1190 | Dummy := Emit_Node (NOTHING); | |
| 1191 | end if; | |
| 1192 | ||
| 1193 | end Parse_Branch; | |
| 1194 | ||
| 1195 | --------------------------- | |
| 1196 | -- Parse_Character_Class -- | |
| 1197 | --------------------------- | |
| 1198 | ||
| 1199 | procedure Parse_Character_Class (IP : out Pointer) is | |
| 1200 | Bitmap : Character_Class; | |
| 1201 | Invert : Boolean := False; | |
| 1202 | In_Range : Boolean := False; | |
| 1203 | Named_Class : Std_Class := ANYOF_NONE; | |
| 1204 | Value : Character; | |
| 1205 | Last_Value : Character := ASCII.Nul; | |
| 1206 | ||
| 1207 | begin | |
| 1208 | Reset_Class (Bitmap); | |
| 1209 | ||
| 1210 | -- Do we have an invert character class ? | |
| 1211 | ||
| 1212 | if Parse_Pos <= Parse_End | |
| 1213 | and then Expression (Parse_Pos) = '^' | |
| 1214 | then | |
| 1215 | Invert := True; | |
| 1216 | Parse_Pos := Parse_Pos + 1; | |
| 1217 | end if; | |
| 1218 | ||
| 1219 | -- First character can be ] or -, without closing the class. | |
| 1220 | ||
| 1221 | if Parse_Pos <= Parse_End | |
| 1222 | and then (Expression (Parse_Pos) = ']' | |
| 1223 | or else Expression (Parse_Pos) = '-') | |
| 1224 | then | |
| 1225 | Set_In_Class (Bitmap, Expression (Parse_Pos)); | |
| 1226 | Parse_Pos := Parse_Pos + 1; | |
| 1227 | end if; | |
| 1228 | ||
| 1229 | -- While we don't have the end of the class | |
| 1230 | ||
| 1231 | while Parse_Pos <= Parse_End | |
| 1232 | and then Expression (Parse_Pos) /= ']' | |
| 1233 | loop | |
| 1234 | Named_Class := ANYOF_NONE; | |
| 1235 | Value := Expression (Parse_Pos); | |
| 1236 | Parse_Pos := Parse_Pos + 1; | |
| 1237 | ||
| 1238 | -- Do we have a Posix character class | |
| 1239 | if Value = '[' then | |
| 1240 | Named_Class := Parse_Posix_Character_Class; | |
| 1241 | ||
| 1242 | elsif Value = '\' then | |
| 1243 | if Parse_Pos = Parse_End then | |
| 1244 | Fail ("Trailing \"); | |
| 1245 | end if; | |
| 1246 | Value := Expression (Parse_Pos); | |
| 1247 | Parse_Pos := Parse_Pos + 1; | |
| 1248 | ||
| 1249 | case Value is | |
| 1250 | when 'w' => Named_Class := ANYOF_ALNUM; | |
| 1251 | when 'W' => Named_Class := ANYOF_NALNUM; | |
| 1252 | when 's' => Named_Class := ANYOF_SPACE; | |
| 1253 | when 'S' => Named_Class := ANYOF_NSPACE; | |
| 1254 | when 'd' => Named_Class := ANYOF_DIGIT; | |
| 1255 | when 'D' => Named_Class := ANYOF_NDIGIT; | |
| 1256 | when 'n' => Value := ASCII.LF; | |
| 1257 | when 'r' => Value := ASCII.CR; | |
| 1258 | when 't' => Value := ASCII.HT; | |
| 1259 | when 'f' => Value := ASCII.FF; | |
| 1260 | when 'e' => Value := ASCII.ESC; | |
| 1261 | when 'a' => Value := ASCII.BEL; | |
| 1262 | ||
| 1263 | -- when 'x' => ??? hexadecimal value | |
| 1264 | -- when 'c' => ??? control character | |
| 1265 | -- when '0'..'9' => ??? octal character | |
| 1266 | ||
| 1267 | when others => null; | |
| 1268 | end case; | |
| 1269 | end if; | |
| 1270 | ||
| 1271 | -- Do we have a character class? | |
| 1272 | ||
| 1273 | if Named_Class /= ANYOF_NONE then | |
| 1274 | ||
| 1275 | -- A range like 'a-\d' or 'a-[:digit:] is not a range | |
| 1276 | ||
| 1277 | if In_Range then | |
| 1278 | Set_In_Class (Bitmap, Last_Value); | |
| 1279 | Set_In_Class (Bitmap, '-'); | |
| 1280 | In_Range := False; | |
| 1281 | end if; | |
| 1282 | ||
| 1283 | -- Expand the range | |
| 1284 | ||
| 1285 | case Named_Class is | |
| 1286 | when ANYOF_NONE => null; | |
| 1287 | ||
| 1288 | when ANYOF_ALNUM | ANYOF_ALNUMC => | |
| 1289 | for Value in Class_Byte'Range loop | |
| 1290 | if Is_Alnum (Character'Val (Value)) then | |
| 1291 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1292 | end if; | |
| 1293 | end loop; | |
| 1294 | ||
| 1295 | when ANYOF_NALNUM | ANYOF_NALNUMC => | |
| 1296 | for Value in Class_Byte'Range loop | |
| 1297 | if not Is_Alnum (Character'Val (Value)) then | |
| 1298 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1299 | end if; | |
| 1300 | end loop; | |
| 1301 | ||
| 1302 | when ANYOF_SPACE => | |
| 1303 | for Value in Class_Byte'Range loop | |
| 1304 | if Is_Space (Character'Val (Value)) then | |
| 1305 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1306 | end if; | |
| 1307 | end loop; | |
| 1308 | ||
| 1309 | when ANYOF_NSPACE => | |
| 1310 | for Value in Class_Byte'Range loop | |
| 1311 | if not Is_Space (Character'Val (Value)) then | |
| 1312 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1313 | end if; | |
| 1314 | end loop; | |
| 1315 | ||
| 1316 | when ANYOF_DIGIT => | |
| 1317 | for Value in Class_Byte'Range loop | |
| 1318 | if Is_Digit (Character'Val (Value)) then | |
| 1319 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1320 | end if; | |
| 1321 | end loop; | |
| 1322 | ||
| 1323 | when ANYOF_NDIGIT => | |
| 1324 | for Value in Class_Byte'Range loop | |
| 1325 | if not Is_Digit (Character'Val (Value)) then | |
| 1326 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1327 | end if; | |
| 1328 | end loop; | |
| 1329 | ||
| 1330 | when ANYOF_ALPHA => | |
| 1331 | for Value in Class_Byte'Range loop | |
| 1332 | if Is_Letter (Character'Val (Value)) then | |
| 1333 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1334 | end if; | |
| 1335 | end loop; | |
| 1336 | ||
| 1337 | when ANYOF_NALPHA => | |
| 1338 | for Value in Class_Byte'Range loop | |
| 1339 | if not Is_Letter (Character'Val (Value)) then | |
| 1340 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1341 | end if; | |
| 1342 | end loop; | |
| 1343 | ||
| 1344 | when ANYOF_ASCII => | |
| 1345 | for Value in 0 .. 127 loop | |
| 1346 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1347 | end loop; | |
| 1348 | ||
| 1349 | when ANYOF_NASCII => | |
| 1350 | for Value in 128 .. 255 loop | |
| 1351 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1352 | end loop; | |
| 1353 | ||
| 1354 | when ANYOF_CNTRL => | |
| 1355 | for Value in Class_Byte'Range loop | |
| 1356 | if Is_Control (Character'Val (Value)) then | |
| 1357 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1358 | end if; | |
| 1359 | end loop; | |
| 1360 | ||
| 1361 | when ANYOF_NCNTRL => | |
| 1362 | for Value in Class_Byte'Range loop | |
| 1363 | if not Is_Control (Character'Val (Value)) then | |
| 1364 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1365 | end if; | |
| 1366 | end loop; | |
| 1367 | ||
| 1368 | when ANYOF_GRAPH => | |
| 1369 | for Value in Class_Byte'Range loop | |
| 1370 | if Is_Graphic (Character'Val (Value)) then | |
| 1371 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1372 | end if; | |
| 1373 | end loop; | |
| 1374 | ||
| 1375 | when ANYOF_NGRAPH => | |
| 1376 | for Value in Class_Byte'Range loop | |
| 1377 | if not Is_Graphic (Character'Val (Value)) then | |
| 1378 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1379 | end if; | |
| 1380 | end loop; | |
| 1381 | ||
| 1382 | when ANYOF_LOWER => | |
| 1383 | for Value in Class_Byte'Range loop | |
| 1384 | if Is_Lower (Character'Val (Value)) then | |
| 1385 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1386 | end if; | |
| 1387 | end loop; | |
| 1388 | ||
| 1389 | when ANYOF_NLOWER => | |
| 1390 | for Value in Class_Byte'Range loop | |
| 1391 | if not Is_Lower (Character'Val (Value)) then | |
| 1392 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1393 | end if; | |
| 1394 | end loop; | |
| 1395 | ||
| 1396 | when ANYOF_PRINT => | |
| 1397 | for Value in Class_Byte'Range loop | |
| 1398 | if Is_Printable (Character'Val (Value)) then | |
| 1399 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1400 | end if; | |
| 1401 | end loop; | |
| 1402 | ||
| 1403 | when ANYOF_NPRINT => | |
| 1404 | for Value in Class_Byte'Range loop | |
| 1405 | if not Is_Printable (Character'Val (Value)) then | |
| 1406 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1407 | end if; | |
| 1408 | end loop; | |
| 1409 | ||
| 1410 | when ANYOF_PUNCT => | |
| 1411 | for Value in Class_Byte'Range loop | |
| 1412 | if Is_Printable (Character'Val (Value)) | |
| 1413 | and then not Is_Space (Character'Val (Value)) | |
| 1414 | and then not Is_Alnum (Character'Val (Value)) | |
| 1415 | then | |
| 1416 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1417 | end if; | |
| 1418 | end loop; | |
| 1419 | ||
| 1420 | when ANYOF_NPUNCT => | |
| 1421 | for Value in Class_Byte'Range loop | |
| 1422 | if not Is_Printable (Character'Val (Value)) | |
| 1423 | or else Is_Space (Character'Val (Value)) | |
| 1424 | or else Is_Alnum (Character'Val (Value)) | |
| 1425 | then | |
| 1426 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1427 | end if; | |
| 1428 | end loop; | |
| 1429 | ||
| 1430 | when ANYOF_UPPER => | |
| 1431 | for Value in Class_Byte'Range loop | |
| 1432 | if Is_Upper (Character'Val (Value)) then | |
| 1433 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1434 | end if; | |
| 1435 | end loop; | |
| 1436 | ||
| 1437 | when ANYOF_NUPPER => | |
| 1438 | for Value in Class_Byte'Range loop | |
| 1439 | if not Is_Upper (Character'Val (Value)) then | |
| 1440 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1441 | end if; | |
| 1442 | end loop; | |
| 1443 | ||
| 1444 | when ANYOF_XDIGIT => | |
| 1445 | for Value in Class_Byte'Range loop | |
| 1446 | if Is_Hexadecimal_Digit (Character'Val (Value)) then | |
| 1447 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1448 | end if; | |
| 1449 | end loop; | |
| 1450 | ||
| 1451 | when ANYOF_NXDIGIT => | |
| 1452 | for Value in Class_Byte'Range loop | |
| 1453 | if not Is_Hexadecimal_Digit | |
| 1454 | (Character'Val (Value)) | |
| 1455 | then | |
| 1456 | Set_In_Class (Bitmap, Character'Val (Value)); | |
| 1457 | end if; | |
| 1458 | end loop; | |
| 1459 | ||
| 1460 | end case; | |
| 1461 | ||
| 1462 | -- Not a character range | |
| 1463 | ||
| 1464 | elsif not In_Range then | |
| 1465 | Last_Value := Value; | |
| 1466 | ||
| 1467 | if Expression (Parse_Pos) = '-' | |
| 1468 | and then Parse_Pos < Parse_End | |
| 1469 | and then Expression (Parse_Pos + 1) /= ']' | |
| 1470 | then | |
| 1471 | Parse_Pos := Parse_Pos + 1; | |
| 1472 | ||
| 1473 | -- Do we have a range like '\d-a' and '[:space:]-a' | |
| 1474 | -- which is not a real range | |
| 1475 | ||
| 1476 | if Named_Class /= ANYOF_NONE then | |
| 1477 | Set_In_Class (Bitmap, '-'); | |
| 1478 | else | |
| 1479 | In_Range := True; | |
| 1480 | end if; | |
| 1481 | ||
| 1482 | else | |
| 1483 | Set_In_Class (Bitmap, Value); | |
| 1484 | ||
| 1485 | end if; | |
| 1486 | ||
| 1487 | -- Else in a character range | |
| 1488 | ||
| 1489 | else | |
| 1490 | if Last_Value > Value then | |
| 1491 | Fail ("Invalid Range [" & Last_Value'Img | |
| 1492 | & "-" & Value'Img & "]"); | |
| 1493 | end if; | |
| 1494 | ||
| 1495 | while Last_Value <= Value loop | |
| 1496 | Set_In_Class (Bitmap, Last_Value); | |
| 1497 | Last_Value := Character'Succ (Last_Value); | |
| 1498 | end loop; | |
| 1499 | ||
| 1500 | In_Range := False; | |
| 1501 | ||
| 1502 | end if; | |
| 1503 | ||
| 1504 | end loop; | |
| 1505 | ||
| 1506 | -- Optimize case-insensitive ranges (put the upper case or lower | |
| 1507 | -- case character into the bitmap) | |
| 1508 | ||
| 1509 | if (Flags and Case_Insensitive) /= 0 then | |
| 1510 | for C in Character'Range loop | |
| 1511 | if Get_From_Class (Bitmap, C) then | |
| 1512 | Set_In_Class (Bitmap, To_Lower (C)); | |
| 1513 | Set_In_Class (Bitmap, To_Upper (C)); | |
| 1514 | end if; | |
| 1515 | end loop; | |
| 1516 | end if; | |
| 1517 | ||
| 1518 | -- Optimize inverted classes | |
| 1519 | ||
| 1520 | if Invert then | |
| 1521 | for J in Bitmap'Range loop | |
| 1522 | Bitmap (J) := not Bitmap (J); | |
| 1523 | end loop; | |
| 1524 | end if; | |
| 1525 | ||
| 1526 | Parse_Pos := Parse_Pos + 1; | |
| 1527 | ||
| 1528 | -- Emit the class | |
| 1529 | ||
| 1530 | IP := Emit_Node (ANYOF); | |
| 1531 | Emit_Class (Bitmap); | |
| 1532 | end Parse_Character_Class; | |
| 1533 | ||
| 1534 | ------------------- | |
| 1535 | -- Parse_Literal -- | |
| 1536 | ------------------- | |
| 1537 | ||
| 1538 | -- This is a bit tricky due to quoted chars and due to | |
| 1539 | -- the multiplier characters '*', '+', and '?' that | |
| 1540 | -- take the SINGLE char previous as their operand. | |
| 1541 | -- | |
| 1542 | -- On entry, the character at Parse_Pos - 1 is going to go | |
| 1543 | -- into the string, no matter what it is. It could be | |
| 1544 | -- following a \ if Parse_Atom was entered from the '\' case. | |
| 1545 | -- | |
| 1546 | -- Basic idea is to pick up a good char in C and examine | |
| 1547 | -- the next char. If Is_Mult (C) then twiddle, if it's a \ | |
| 1548 | -- then frozzle and if it's another magic char then push C and | |
| 1549 | -- terminate the string. If none of the above, push C on the | |
| 1550 | -- string and go around again. | |
| 1551 | -- | |
| 1552 | -- Start_Pos is used to remember where "the current character" | |
| 1553 | -- starts in the string, if due to an Is_Mult we need to back | |
| 1554 | -- up and put the current char in a separate 1-character string. | |
| 1555 | -- When Start_Pos is 0, C is the only char in the string; | |
| 1556 | -- this is used in Is_Mult handling, and in setting the SIMPLE | |
| 1557 | -- flag at the end. | |
| 1558 | ||
| 1559 | procedure Parse_Literal | |
| 1560 | (Expr_Flags : in out Expression_Flags; | |
| 1561 | IP : out Pointer) | |
| 1562 | is | |
| 1563 | Start_Pos : Natural := 0; | |
| 1564 | C : Character; | |
| 1565 | Length_Ptr : Pointer; | |
| 598c3446 | 1566 | Has_Special_Operator : Boolean := False; |
| 38cbfe40 RK |
1567 | |
| 1568 | begin | |
| 1569 | Parse_Pos := Parse_Pos - 1; -- Look at current character | |
| 1570 | ||
| 1571 | if (Flags and Case_Insensitive) /= 0 then | |
| 1572 | IP := Emit_Node (EXACTF); | |
| 1573 | else | |
| 1574 | IP := Emit_Node (EXACT); | |
| 1575 | end if; | |
| 1576 | ||
| 1577 | Length_Ptr := Emit_Ptr; | |
| 1578 | Emit_Ptr := String_Operand (IP); | |
| 1579 | ||
| 1580 | Parse_Loop : | |
| 1581 | loop | |
| 1582 | ||
| 1583 | C := Expression (Parse_Pos); -- Get current character | |
| 1584 | ||
| 1585 | case C is | |
| 1586 | when '.' | '[' | '(' | ')' | '|' | ASCII.LF | '$' | '^' => | |
| 1587 | ||
| 1588 | if Start_Pos = 0 then | |
| 598c3446 | 1589 | Start_Pos := Parse_Pos; |
| 38cbfe40 RK |
1590 | Emit (C); -- First character is always emitted |
| 1591 | else | |
| 1592 | exit Parse_Loop; -- Else we are done | |
| 1593 | end if; | |
| 1594 | ||
| 1595 | when '?' | '+' | '*' | '{' => | |
| 1596 | ||
| 1597 | if Start_Pos = 0 then | |
| 598c3446 | 1598 | Start_Pos := Parse_Pos; |
| 38cbfe40 RK |
1599 | Emit (C); -- First character is always emitted |
| 1600 | ||
| 1601 | -- Are we looking at an operator, or is this | |
| 1602 | -- simply a normal character ? | |
| 1603 | elsif not Is_Mult (Parse_Pos) then | |
| 598c3446 GB |
1604 | Start_Pos := Parse_Pos; |
| 1605 | Case_Emit (C); | |
| 38cbfe40 RK |
1606 | else |
| 1607 | -- We've got something like "abc?d". Mark this as a | |
| 1608 | -- special case. What we want to emit is a first | |
| 1609 | -- constant string for "ab", then one for "c" that will | |
| 1610 | -- ultimately be transformed with a CURLY operator, A | |
| 1611 | -- special case has to be handled for "a?", since there | |
| 1612 | -- is no initial string to emit. | |
| 598c3446 | 1613 | Has_Special_Operator := True; |
| 38cbfe40 RK |
1614 | exit Parse_Loop; |
| 1615 | end if; | |
| 1616 | ||
| 1617 | when '\' => | |
| 598c3446 | 1618 | Start_Pos := Parse_Pos; |
| 38cbfe40 RK |
1619 | if Parse_Pos = Parse_End then |
| 1620 | Fail ("Trailing \"); | |
| 1621 | else | |
| 1622 | case Expression (Parse_Pos + 1) is | |
| 1623 | when 'b' | 'B' | 's' | 'S' | 'd' | 'D' | |
| 1624 | | 'w' | 'W' | '0' .. '9' | 'G' | 'A' | |
| 1625 | => exit Parse_Loop; | |
| 1626 | when 'n' => Emit (ASCII.LF); | |
| 1627 | when 't' => Emit (ASCII.HT); | |
| 1628 | when 'r' => Emit (ASCII.CR); | |
| 1629 | when 'f' => Emit (ASCII.FF); | |
| 1630 | when 'e' => Emit (ASCII.ESC); | |
| 1631 | when 'a' => Emit (ASCII.BEL); | |
| 1632 | when others => Emit (Expression (Parse_Pos + 1)); | |
| 1633 | end case; | |
| 1634 | Parse_Pos := Parse_Pos + 1; | |
| 1635 | end if; | |
| 1636 | ||
| 598c3446 GB |
1637 | when others => |
| 1638 | Start_Pos := Parse_Pos; | |
| 1639 | Case_Emit (C); | |
| 38cbfe40 RK |
1640 | end case; |
| 1641 | ||
| 1642 | exit Parse_Loop when Emit_Ptr - Length_Ptr = 254; | |
| 1643 | ||
| 38cbfe40 RK |
1644 | Parse_Pos := Parse_Pos + 1; |
| 1645 | ||
| 1646 | exit Parse_Loop when Parse_Pos > Parse_End; | |
| 1647 | end loop Parse_Loop; | |
| 1648 | ||
| 1649 | -- Is the string followed by a '*+?{' operator ? If yes, and if there | |
| 1650 | -- is an initial string to emit, do it now. | |
| 1651 | ||
| 598c3446 | 1652 | if Has_Special_Operator |
| 38cbfe40 RK |
1653 | and then Emit_Ptr >= Length_Ptr + 3 |
| 1654 | then | |
| 1655 | Emit_Ptr := Emit_Ptr - 1; | |
| 598c3446 | 1656 | Parse_Pos := Start_Pos; |
| 38cbfe40 RK |
1657 | end if; |
| 1658 | ||
| 1659 | if Emit_Code then | |
| 1660 | Program (Length_Ptr) := Character'Val (Emit_Ptr - Length_Ptr - 2); | |
| 1661 | end if; | |
| 1662 | ||
| 1663 | Expr_Flags.Has_Width := True; | |
| 1664 | ||
| 1665 | -- Slight optimization when there is a single character | |
| 1666 | ||
| 1667 | if Emit_Ptr = Length_Ptr + 2 then | |
| 1668 | Expr_Flags.Simple := True; | |
| 1669 | end if; | |
| 1670 | end Parse_Literal; | |
| 1671 | ||
| 1672 | ----------------- | |
| 1673 | -- Parse_Piece -- | |
| 1674 | ----------------- | |
| 1675 | ||
| 1676 | -- Note that the branching code sequences used for '?' and the | |
| 1677 | -- general cases of '*' and + are somewhat optimized: they use | |
| 1678 | -- the same NOTHING node as both the endmarker for their branch | |
| 1679 | -- list and the body of the last branch. It might seem that | |
| 1680 | -- this node could be dispensed with entirely, but the endmarker | |
| 1681 | -- role is not redundant. | |
| 1682 | ||
| 1683 | procedure Parse_Piece | |
| 1684 | (Expr_Flags : in out Expression_Flags; | |
| 1685 | IP : out Pointer) | |
| 1686 | is | |
| 1687 | Op : Character; | |
| 1688 | New_Flags : Expression_Flags; | |
| 1689 | Greedy : Boolean := True; | |
| 1690 | ||
| 1691 | begin | |
| 1692 | Parse_Atom (New_Flags, IP); | |
| 1693 | ||
| 1694 | if IP = 0 then | |
| 1695 | return; | |
| 1696 | end if; | |
| 1697 | ||
| 1698 | if Parse_Pos > Parse_End | |
| 1699 | or else not Is_Mult (Parse_Pos) | |
| 1700 | then | |
| 1701 | Expr_Flags := New_Flags; | |
| 1702 | return; | |
| 1703 | end if; | |
| 1704 | ||
| 1705 | Op := Expression (Parse_Pos); | |
| 1706 | ||
| 1707 | if Op /= '+' then | |
| 1708 | Expr_Flags := (SP_Start => True, others => False); | |
| 1709 | else | |
| 1710 | Expr_Flags := (Has_Width => True, others => False); | |
| 1711 | end if; | |
| 1712 | ||
| 1713 | -- Detect non greedy operators in the easy cases | |
| 1714 | ||
| 1715 | if Op /= '{' | |
| 1716 | and then Parse_Pos + 1 <= Parse_End | |
| 1717 | and then Expression (Parse_Pos + 1) = '?' | |
| 1718 | then | |
| 1719 | Greedy := False; | |
| 1720 | Parse_Pos := Parse_Pos + 1; | |
| 1721 | end if; | |
| 1722 | ||
| 1723 | -- Generate the byte code | |
| 1724 | ||
| 1725 | case Op is | |
| 1726 | when '*' => | |
| 1727 | ||
| 1728 | if New_Flags.Simple then | |
| 1729 | Insert_Operator (STAR, IP, Greedy); | |
| 1730 | else | |
| 1731 | Link_Tail (IP, Emit_Node (WHILEM)); | |
| 1732 | Insert_Curly_Operator | |
| 1733 | (CURLYX, 0, Max_Curly_Repeat, IP, Greedy); | |
| 1734 | Link_Tail (IP, Emit_Node (NOTHING)); | |
| 1735 | end if; | |
| 1736 | ||
| 1737 | when '+' => | |
| 1738 | ||
| 1739 | if New_Flags.Simple then | |
| 1740 | Insert_Operator (PLUS, IP, Greedy); | |
| 1741 | else | |
| 1742 | Link_Tail (IP, Emit_Node (WHILEM)); | |
| 1743 | Insert_Curly_Operator | |
| 1744 | (CURLYX, 1, Max_Curly_Repeat, IP, Greedy); | |
| 1745 | Link_Tail (IP, Emit_Node (NOTHING)); | |
| 1746 | end if; | |
| 1747 | ||
| 1748 | when '?' => | |
| 1749 | if New_Flags.Simple then | |
| 1750 | Insert_Curly_Operator (CURLY, 0, 1, IP, Greedy); | |
| 1751 | else | |
| 1752 | Link_Tail (IP, Emit_Node (WHILEM)); | |
| 1753 | Insert_Curly_Operator (CURLYX, 0, 1, IP, Greedy); | |
| 1754 | Link_Tail (IP, Emit_Node (NOTHING)); | |
| 1755 | end if; | |
| 1756 | ||
| 1757 | when '{' => | |
| 1758 | declare | |
| 1759 | Min, Max : Natural; | |
| 1760 | ||
| 1761 | begin | |
| 1762 | Get_Curly_Arguments (Parse_Pos, Min, Max, Greedy); | |
| 1763 | ||
| 1764 | if New_Flags.Simple then | |
| 1765 | Insert_Curly_Operator (CURLY, Min, Max, IP, Greedy); | |
| 1766 | else | |
| 1767 | Link_Tail (IP, Emit_Node (WHILEM)); | |
| 1768 | Insert_Curly_Operator (CURLYX, Min, Max, IP, Greedy); | |
| 1769 | Link_Tail (IP, Emit_Node (NOTHING)); | |
| 1770 | end if; | |
| 1771 | end; | |
| 1772 | ||
| 1773 | when others => | |
| 1774 | null; | |
| 1775 | end case; | |
| 1776 | ||
| 1777 | Parse_Pos := Parse_Pos + 1; | |
| 1778 | ||
| 1779 | if Parse_Pos <= Parse_End | |
| 1780 | and then Is_Mult (Parse_Pos) | |
| 1781 | then | |
| 1782 | Fail ("nested *+{"); | |
| 1783 | end if; | |
| 1784 | end Parse_Piece; | |
| 1785 | ||
| 1786 | --------------------------------- | |
| 1787 | -- Parse_Posix_Character_Class -- | |
| 1788 | --------------------------------- | |
| 1789 | ||
| 1790 | function Parse_Posix_Character_Class return Std_Class is | |
| 1791 | Invert : Boolean := False; | |
| 1792 | Class : Std_Class := ANYOF_NONE; | |
| 1793 | E : String renames Expression; | |
| 1794 | ||
| 1795 | begin | |
| 1796 | if Parse_Pos <= Parse_End | |
| 1797 | and then Expression (Parse_Pos) = ':' | |
| 1798 | then | |
| 1799 | Parse_Pos := Parse_Pos + 1; | |
| 1800 | ||
| 1801 | -- Do we have something like: [[:^alpha:]] | |
| 1802 | ||
| 1803 | if Parse_Pos <= Parse_End | |
| 1804 | and then Expression (Parse_Pos) = '^' | |
| 1805 | then | |
| 1806 | Invert := True; | |
| 1807 | Parse_Pos := Parse_Pos + 1; | |
| 1808 | end if; | |
| 1809 | ||
| 1810 | -- All classes have 6 characters at least | |
| 1811 | -- ??? magid constant 6 should have a name! | |
| 1812 | ||
| 1813 | if Parse_Pos + 6 <= Parse_End then | |
| 1814 | ||
| 1815 | case Expression (Parse_Pos) is | |
| 1816 | when 'a' => | |
| 1817 | if E (Parse_Pos .. Parse_Pos + 4) = "alnum:]" then | |
| 1818 | if Invert then | |
| 1819 | Class := ANYOF_NALNUMC; | |
| 1820 | else | |
| 1821 | Class := ANYOF_ALNUMC; | |
| 1822 | end if; | |
| 1823 | ||
| 1824 | elsif E (Parse_Pos .. Parse_Pos + 6) = "alpha:]" then | |
| 1825 | if Invert then | |
| 1826 | Class := ANYOF_NALPHA; | |
| 1827 | else | |
| 1828 | Class := ANYOF_ALPHA; | |
| 1829 | end if; | |
| 1830 | ||
| 1831 | elsif E (Parse_Pos .. Parse_Pos + 6) = "ascii:]" then | |
| 1832 | if Invert then | |
| 1833 | Class := ANYOF_NASCII; | |
| 1834 | else | |
| 1835 | Class := ANYOF_ASCII; | |
| 1836 | end if; | |
| 1837 | ||
| 1838 | end if; | |
| 1839 | ||
| 1840 | when 'c' => | |
| 1841 | if E (Parse_Pos .. Parse_Pos + 6) = "cntrl:]" then | |
| 1842 | if Invert then | |
| 1843 | Class := ANYOF_NCNTRL; | |
| 1844 | else | |
| 1845 | Class := ANYOF_CNTRL; | |
| 1846 | end if; | |
| 1847 | end if; | |
| 1848 | ||
| 1849 | when 'd' => | |
| 1850 | ||
| 1851 | if E (Parse_Pos .. Parse_Pos + 6) = "digit:]" then | |
| 1852 | if Invert then | |
| 1853 | Class := ANYOF_NDIGIT; | |
| 1854 | else | |
| 1855 | Class := ANYOF_DIGIT; | |
| 1856 | end if; | |
| 1857 | end if; | |
| 1858 | ||
| 1859 | when 'g' => | |
| 1860 | ||
| 1861 | if E (Parse_Pos .. Parse_Pos + 6) = "graph:]" then | |
| 1862 | if Invert then | |
| 1863 | Class := ANYOF_NGRAPH; | |
| 1864 | else | |
| 1865 | Class := ANYOF_GRAPH; | |
| 1866 | end if; | |
| 1867 | end if; | |
| 1868 | ||
| 1869 | when 'l' => | |
| 1870 | ||
| 1871 | if E (Parse_Pos .. Parse_Pos + 6) = "lower:]" then | |
| 1872 | if Invert then | |
| 1873 | Class := ANYOF_NLOWER; | |
| 1874 | else | |
| 1875 | Class := ANYOF_LOWER; | |
| 1876 | end if; | |
| 1877 | end if; | |
| 1878 | ||
| 1879 | when 'p' => | |
| 1880 | ||
| 1881 | if E (Parse_Pos .. Parse_Pos + 6) = "print:]" then | |
| 1882 | if Invert then | |
| 1883 | Class := ANYOF_NPRINT; | |
| 1884 | else | |
| 1885 | Class := ANYOF_PRINT; | |
| 1886 | end if; | |
| 1887 | ||
| 1888 | elsif E (Parse_Pos .. Parse_Pos + 6) = "punct:]" then | |
| 1889 | if Invert then | |
| 1890 | Class := ANYOF_NPUNCT; | |
| 1891 | else | |
| 1892 | Class := ANYOF_PUNCT; | |
| 1893 | end if; | |
| 1894 | end if; | |
| 1895 | ||
| 1896 | when 's' => | |
| 1897 | ||
| 1898 | if E (Parse_Pos .. Parse_Pos + 6) = "space:]" then | |
| 1899 | if Invert then | |
| 1900 | Class := ANYOF_NSPACE; | |
| 1901 | else | |
| 1902 | Class := ANYOF_SPACE; | |
| 1903 | end if; | |
| 1904 | end if; | |
| 1905 | ||
| 1906 | when 'u' => | |
| 1907 | ||
| 1908 | if E (Parse_Pos .. Parse_Pos + 6) = "upper:]" then | |
| 1909 | if Invert then | |
| 1910 | Class := ANYOF_NUPPER; | |
| 1911 | else | |
| 1912 | Class := ANYOF_UPPER; | |
| 1913 | end if; | |
| 1914 | end if; | |
| 1915 | ||
| 1916 | when 'w' => | |
| 1917 | ||
| 1918 | if E (Parse_Pos .. Parse_Pos + 5) = "word:]" then | |
| 1919 | if Invert then | |
| 1920 | Class := ANYOF_NALNUM; | |
| 1921 | else | |
| 1922 | Class := ANYOF_ALNUM; | |
| 1923 | end if; | |
| 1924 | ||
| 1925 | Parse_Pos := Parse_Pos - 1; | |
| 1926 | end if; | |
| 1927 | ||
| 1928 | when 'x' => | |
| 1929 | ||
| 1930 | if Parse_Pos + 7 <= Parse_End | |
| 1931 | and then E (Parse_Pos .. Parse_Pos + 7) = "xdigit:]" | |
| 1932 | then | |
| 1933 | if Invert then | |
| 1934 | Class := ANYOF_NXDIGIT; | |
| 1935 | else | |
| 1936 | Class := ANYOF_XDIGIT; | |
| 1937 | end if; | |
| 1938 | ||
| 1939 | Parse_Pos := Parse_Pos + 1; | |
| 1940 | end if; | |
| 1941 | ||
| 1942 | when others => | |
| 1943 | Class := ANYOF_NONE; | |
| 1944 | ||
| 1945 | end case; | |
| 1946 | ||
| 1947 | if Class /= ANYOF_NONE then | |
| 1948 | Parse_Pos := Parse_Pos + 7; | |
| 1949 | end if; | |
| 1950 | ||
| 1951 | else | |
| 1952 | Fail ("Invalid character class"); | |
| 1953 | end if; | |
| 1954 | ||
| 1955 | else | |
| 1956 | return ANYOF_NONE; | |
| 1957 | end if; | |
| 1958 | ||
| 1959 | return Class; | |
| 1960 | end Parse_Posix_Character_Class; | |
| 1961 | ||
| 1962 | Expr_Flags : Expression_Flags; | |
| 1963 | Result : Pointer; | |
| 1964 | ||
| 1965 | -- Start of processing for Compile | |
| 1966 | ||
| 1967 | begin | |
| 1968 | Emit (MAGIC); | |
| 1969 | Parse (False, Expr_Flags, Result); | |
| 1970 | ||
| 1971 | if Result = 0 then | |
| 1972 | Fail ("Couldn't compile expression"); | |
| 1973 | end if; | |
| 1974 | ||
| 1975 | Final_Code_Size := Emit_Ptr - 1; | |
| 1976 | ||
| 1977 | -- Do we want to actually compile the expression, or simply get the | |
| 1978 | -- code size ??? | |
| 1979 | ||
| 1980 | if Emit_Code then | |
| 1981 | Optimize (PM); | |
| 1982 | end if; | |
| 1983 | ||
| 1984 | PM.Flags := Flags; | |
| 1985 | end Compile; | |
| 1986 | ||
| 1987 | function Compile | |
| 1988 | (Expression : String; | |
| 1989 | Flags : Regexp_Flags := No_Flags) | |
| 1990 | return Pattern_Matcher | |
| 1991 | is | |
| 1992 | Size : Program_Size; | |
| 1993 | Dummy : Pattern_Matcher (0); | |
| 1994 | ||
| 1995 | begin | |
| 1996 | Compile (Dummy, Expression, Size, Flags); | |
| 1997 | ||
| 1998 | declare | |
| 1999 | Result : Pattern_Matcher (Size); | |
| 2000 | begin | |
| 2001 | Compile (Result, Expression, Size, Flags); | |
| 2002 | return Result; | |
| 2003 | end; | |
| 2004 | end Compile; | |
| 2005 | ||
| 2006 | procedure Compile | |
| 2007 | (Matcher : out Pattern_Matcher; | |
| 2008 | Expression : String; | |
| 2009 | Flags : Regexp_Flags := No_Flags) | |
| 2010 | is | |
| 2011 | Size : Program_Size; | |
| 2012 | ||
| 2013 | begin | |
| 2014 | Compile (Matcher, Expression, Size, Flags); | |
| 2015 | end Compile; | |
| 2016 | ||
| 2017 | ---------- | |
| 2018 | -- Dump -- | |
| 2019 | ---------- | |
| 2020 | ||
| 2021 | procedure Dump (Self : Pattern_Matcher) is | |
| 2022 | ||
| 2023 | -- Index : Pointer := Program_First + 1; | |
| 2024 | -- What is the above line for ??? | |
| 2025 | ||
| 2026 | Op : Opcode; | |
| 2027 | Program : Program_Data renames Self.Program; | |
| 2028 | ||
| 2029 | procedure Dump_Until | |
| 2030 | (Start : Pointer; | |
| 2031 | Till : Pointer; | |
| 2032 | Indent : Natural := 0); | |
| 2033 | -- Dump the program until the node Till (not included) is met. | |
| 2034 | -- Every line is indented with Index spaces at the beginning | |
| 2035 | -- Dumps till the end if Till is 0. | |
| 2036 | ||
| 2037 | ---------------- | |
| 2038 | -- Dump_Until -- | |
| 2039 | ---------------- | |
| 2040 | ||
| 2041 | procedure Dump_Until | |
| 2042 | (Start : Pointer; | |
| 2043 | Till : Pointer; | |
| 2044 | Indent : Natural := 0) | |
| 2045 | is | |
| 2046 | Next : Pointer; | |
| 2047 | Index : Pointer := Start; | |
| 2048 | Local_Indent : Natural := Indent; | |
| 2049 | Length : Pointer; | |
| 2050 | ||
| 2051 | begin | |
| 2052 | while Index < Till loop | |
| 2053 | ||
| 2054 | Op := Opcode'Val (Character'Pos ((Self.Program (Index)))); | |
| 2055 | ||
| 2056 | if Op = CLOSE then | |
| 2057 | Local_Indent := Local_Indent - 3; | |
| 2058 | end if; | |
| 2059 | ||
| 2060 | declare | |
| 2061 | Point : String := Pointer'Image (Index); | |
| 2062 | ||
| 2063 | begin | |
| 2064 | for J in 1 .. 6 - Point'Length loop | |
| 2065 | Put (' '); | |
| 2066 | end loop; | |
| 2067 | ||
| 2068 | Put (Point | |
| 2069 | & " : " | |
| 2070 | & (1 .. Local_Indent => ' ') | |
| 2071 | & Opcode'Image (Op)); | |
| 2072 | end; | |
| 2073 | ||
| 2074 | -- Print the parenthesis number | |
| 2075 | ||
| 2076 | if Op = OPEN or else Op = CLOSE or else Op = REFF then | |
| 2077 | Put (Natural'Image (Character'Pos (Program (Index + 3)))); | |
| 2078 | end if; | |
| 2079 | ||
| 2080 | Next := Index + Get_Next_Offset (Program, Index); | |
| 2081 | ||
| 2082 | if Next = Index then | |
| 2083 | Put (" (next at 0)"); | |
| 2084 | else | |
| 2085 | Put (" (next at " & Pointer'Image (Next) & ")"); | |
| 2086 | end if; | |
| 2087 | ||
| 2088 | case Op is | |
| 2089 | ||
| 2090 | -- Character class operand | |
| 2091 | ||
| 2092 | when ANYOF => null; | |
| 2093 | declare | |
| 2094 | Bitmap : Character_Class; | |
| 2095 | Last : Character := ASCII.Nul; | |
| 2096 | Current : Natural := 0; | |
| 2097 | ||
| 2098 | Current_Char : Character; | |
| 2099 | ||
| 2100 | begin | |
| 2101 | Bitmap_Operand (Program, Index, Bitmap); | |
| 2102 | Put (" operand="); | |
| 2103 | ||
| 2104 | while Current <= 255 loop | |
| 2105 | Current_Char := Character'Val (Current); | |
| 2106 | ||
| 2107 | -- First item in a range | |
| 2108 | ||
| 2109 | if Get_From_Class (Bitmap, Current_Char) then | |
| 2110 | Last := Current_Char; | |
| 2111 | ||
| 2112 | -- Search for the last item in the range | |
| 2113 | ||
| 2114 | loop | |
| 2115 | Current := Current + 1; | |
| 2116 | exit when Current > 255; | |
| 2117 | Current_Char := Character'Val (Current); | |
| 2118 | exit when | |
| 2119 | not Get_From_Class (Bitmap, Current_Char); | |
| 2120 | ||
| 2121 | end loop; | |
| 2122 | ||
| 2123 | if Last <= ' ' then | |
| 2124 | Put (Last'Img); | |
| 2125 | else | |
| 2126 | Put (Last); | |
| 2127 | end if; | |
| 2128 | ||
| 2129 | if Character'Succ (Last) /= Current_Char then | |
| 2130 | Put ("-" & Character'Pred (Current_Char)); | |
| 2131 | end if; | |
| 2132 | ||
| 2133 | else | |
| 2134 | Current := Current + 1; | |
| 2135 | end if; | |
| 2136 | end loop; | |
| 2137 | ||
| 2138 | New_Line; | |
| 2139 | Index := Index + 3 + Bitmap'Length; | |
| 2140 | end; | |
| 2141 | ||
| 2142 | -- string operand | |
| 2143 | ||
| 2144 | when EXACT | EXACTF => | |
| 2145 | Length := String_Length (Program, Index); | |
| 2146 | Put (" operand (length:" & Program_Size'Image (Length + 1) | |
| 2147 | & ") =" | |
| 2148 | & String (Program (String_Operand (Index) | |
| 2149 | .. String_Operand (Index) | |
| 2150 | + Length))); | |
| 2151 | Index := String_Operand (Index) + Length + 1; | |
| 2152 | New_Line; | |
| 2153 | ||
| 2154 | -- Node operand | |
| 2155 | ||
| 2156 | when BRANCH => | |
| 2157 | New_Line; | |
| 2158 | Dump_Until (Index + 3, Next, Local_Indent + 3); | |
| 2159 | Index := Next; | |
| 2160 | ||
| 2161 | when STAR | PLUS => | |
| 2162 | New_Line; | |
| 2163 | ||
| 2164 | -- Only one instruction | |
| 2165 | ||
| 2166 | Dump_Until (Index + 3, Index + 4, Local_Indent + 3); | |
| 2167 | Index := Next; | |
| 2168 | ||
| 2169 | when CURLY | CURLYX => | |
| 2170 | Put (" {" | |
| 2171 | & Natural'Image (Read_Natural (Program, Index + 3)) | |
| 2172 | & "," | |
| 2173 | & Natural'Image (Read_Natural (Program, Index + 5)) | |
| 2174 | & "}"); | |
| 2175 | New_Line; | |
| 2176 | Dump_Until (Index + 7, Next, Local_Indent + 3); | |
| 2177 | Index := Next; | |
| 2178 | ||
| 2179 | when OPEN => | |
| 2180 | New_Line; | |
| 2181 | Index := Index + 4; | |
| 2182 | Local_Indent := Local_Indent + 3; | |
| 2183 | ||
| 2184 | when CLOSE | REFF => | |
| 2185 | New_Line; | |
| 2186 | Index := Index + 4; | |
| 2187 | ||
| 2188 | when EOP => | |
| 2189 | Index := Index + 3; | |
| 2190 | New_Line; | |
| 2191 | exit; | |
| 2192 | ||
| 2193 | -- No operand | |
| 2194 | ||
| 2195 | when others => | |
| 2196 | Index := Index + 3; | |
| 2197 | New_Line; | |
| 2198 | end case; | |
| 2199 | end loop; | |
| 2200 | end Dump_Until; | |
| 2201 | ||
| 2202 | -- Start of processing for Dump | |
| 2203 | ||
| 2204 | begin | |
| 2205 | pragma Assert (Self.Program (Program_First) = MAGIC, | |
| 2206 | "Corrupted Pattern_Matcher"); | |
| 2207 | ||
| 2208 | Put_Line ("Must start with (Self.First) = " | |
| 2209 | & Character'Image (Self.First)); | |
| 2210 | ||
| 2211 | if (Self.Flags and Case_Insensitive) /= 0 then | |
| 2212 | Put_Line (" Case_Insensitive mode"); | |
| 2213 | end if; | |
| 2214 | ||
| 2215 | if (Self.Flags and Single_Line) /= 0 then | |
| 2216 | Put_Line (" Single_Line mode"); | |
| 2217 | end if; | |
| 2218 | ||
| 2219 | if (Self.Flags and Multiple_Lines) /= 0 then | |
| 2220 | Put_Line (" Multiple_Lines mode"); | |
| 2221 | end if; | |
| 2222 | ||
| 2223 | Put_Line (" 1 : MAGIC"); | |
| 2224 | Dump_Until (Program_First + 1, Self.Program'Last + 1); | |
| 2225 | end Dump; | |
| 2226 | ||
| 2227 | -------------------- | |
| 2228 | -- Get_From_Class -- | |
| 2229 | -------------------- | |
| 2230 | ||
| 2231 | function Get_From_Class | |
| 2232 | (Bitmap : Character_Class; | |
| 2233 | C : Character) | |
| 2234 | return Boolean | |
| 2235 | is | |
| 2236 | Value : constant Class_Byte := Character'Pos (C); | |
| 2237 | ||
| 2238 | begin | |
| 2239 | return (Bitmap (Value / 8) | |
| 2240 | and Bit_Conversion (Value mod 8)) /= 0; | |
| 2241 | end Get_From_Class; | |
| 2242 | ||
| 2243 | -------------- | |
| 2244 | -- Get_Next -- | |
| 2245 | -------------- | |
| 2246 | ||
| 2247 | function Get_Next (Program : Program_Data; IP : Pointer) return Pointer is | |
| 2248 | Offset : constant Pointer := Get_Next_Offset (Program, IP); | |
| 2249 | ||
| 2250 | begin | |
| 2251 | if Offset = 0 then | |
| 2252 | return 0; | |
| 2253 | else | |
| 2254 | return IP + Offset; | |
| 2255 | end if; | |
| 2256 | end Get_Next; | |
| 2257 | ||
| 2258 | --------------------- | |
| 2259 | -- Get_Next_Offset -- | |
| 2260 | --------------------- | |
| 2261 | ||
| 2262 | function Get_Next_Offset | |
| 2263 | (Program : Program_Data; | |
| 2264 | IP : Pointer) | |
| 2265 | return Pointer | |
| 2266 | is | |
| 2267 | begin | |
| 2268 | return Pointer (Read_Natural (Program, IP + 1)); | |
| 2269 | end Get_Next_Offset; | |
| 2270 | ||
| 2271 | -------------- | |
| 2272 | -- Is_Alnum -- | |
| 2273 | -------------- | |
| 2274 | ||
| 2275 | function Is_Alnum (C : Character) return Boolean is | |
| 2276 | begin | |
| 2277 | return Is_Alphanumeric (C) or else C = '_'; | |
| 2278 | end Is_Alnum; | |
| 2279 | ||
| 2280 | ------------------ | |
| 2281 | -- Is_Printable -- | |
| 2282 | ------------------ | |
| 2283 | ||
| 2284 | function Is_Printable (C : Character) return Boolean is | |
| 2285 | Value : constant Natural := Character'Pos (C); | |
| 2286 | ||
| 2287 | begin | |
| 2288 | return (Value > 32 and then Value < 127) | |
| 2289 | or else Is_Space (C); | |
| 2290 | end Is_Printable; | |
| 2291 | ||
| 2292 | -------------- | |
| 2293 | -- Is_Space -- | |
| 2294 | -------------- | |
| 2295 | ||
| 2296 | function Is_Space (C : Character) return Boolean is | |
| 2297 | begin | |
| 2298 | return C = ' ' | |
| 2299 | or else C = ASCII.HT | |
| 2300 | or else C = ASCII.CR | |
| 2301 | or else C = ASCII.LF | |
| 2302 | or else C = ASCII.VT | |
| 2303 | or else C = ASCII.FF; | |
| 2304 | end Is_Space; | |
| 2305 | ||
| 2306 | ----------- | |
| 2307 | -- Match -- | |
| 2308 | ----------- | |
| 2309 | ||
| 2310 | procedure Match | |
| 2311 | (Self : Pattern_Matcher; | |
| 2312 | Data : String; | |
| 2313 | Matches : out Match_Array) | |
| 2314 | is | |
| 2315 | Program : Program_Data renames Self.Program; -- Shorter notation | |
| 2316 | ||
| 2317 | -- Global work variables | |
| 2318 | ||
| 2319 | Input_Pos : Natural; -- String-input pointer | |
| 2320 | BOL_Pos : Natural; -- Beginning of input, for ^ check | |
| 2321 | Matched : Boolean := False; -- Until proven True | |
| 2322 | ||
| 2323 | Matches_Full : Match_Array (0 .. Natural'Max (Self.Paren_Count, | |
| 2324 | Matches'Last)); | |
| 2325 | -- Stores the value of all the parenthesis pairs. | |
| 2326 | -- We do not use directly Matches, so that we can also use back | |
| 2327 | -- references (REFF) even if Matches is too small. | |
| 2328 | ||
| 2329 | type Natural_Array is array (Match_Count range <>) of Natural; | |
| 2330 | Matches_Tmp : Natural_Array (Matches_Full'Range); | |
| 2331 | -- Save the opening position of parenthesis. | |
| 2332 | ||
| 2333 | Last_Paren : Natural := 0; | |
| 2334 | -- Last parenthesis seen | |
| 2335 | ||
| 2336 | Greedy : Boolean := True; | |
| 2337 | -- True if the next operator should be greedy | |
| 2338 | ||
| 2339 | type Current_Curly_Record; | |
| 2340 | type Current_Curly_Access is access all Current_Curly_Record; | |
| 2341 | type Current_Curly_Record is record | |
| 2342 | Paren_Floor : Natural; -- How far back to strip parenthesis data | |
| 2343 | Cur : Integer; -- How many instances of scan we've matched | |
| 2344 | Min : Natural; -- Minimal number of scans to match | |
| 2345 | Max : Natural; -- Maximal number of scans to match | |
| 2346 | Greedy : Boolean; -- Whether to work our way up or down | |
| 2347 | Scan : Pointer; -- The thing to match | |
| 2348 | Next : Pointer; -- What has to match after it | |
| 2349 | Lastloc : Natural; -- Where we started matching this scan | |
| 2350 | Old_Cc : Current_Curly_Access; -- Before we started this one | |
| 2351 | end record; | |
| 2352 | -- Data used to handle the curly operator and the plus and star | |
| 2353 | -- operators for complex expressions. | |
| 2354 | ||
| 2355 | Current_Curly : Current_Curly_Access := null; | |
| 2356 | -- The curly currently being processed. | |
| 2357 | ||
| 2358 | ----------------------- | |
| 2359 | -- Local Subprograms -- | |
| 2360 | ----------------------- | |
| 2361 | ||
| 2362 | function Index (Start : Positive; C : Character) return Natural; | |
| 2363 | -- Find character C in Data starting at Start and return position | |
| 2364 | ||
| 2365 | function Repeat | |
| 2366 | (IP : Pointer; | |
| 2367 | Max : Natural := Natural'Last) | |
| 2368 | return Natural; | |
| 2369 | -- Repeatedly match something simple, report how many | |
| 2370 | -- It only matches on things of length 1. | |
| 2371 | -- Starting from Input_Pos, it matches at most Max CURLY. | |
| 2372 | ||
| 2373 | function Try (Pos : in Positive) return Boolean; | |
| 2374 | -- Try to match at specific point | |
| 2375 | ||
| 2376 | function Match (IP : Pointer) return Boolean; | |
| 2377 | -- This is the main matching routine. Conceptually the strategy | |
| 2378 | -- is simple: check to see whether the current node matches, | |
| 2379 | -- call self recursively to see whether the rest matches, | |
| 2380 | -- and then act accordingly. | |
| 2381 | -- | |
| 2382 | -- In practice Match makes some effort to avoid recursion, in | |
| 2383 | -- particular by going through "ordinary" nodes (that don't | |
| 2384 | -- need to know whether the rest of the match failed) by | |
| 2385 | -- using a loop instead of recursion. | |
| 2386 | ||
| 2387 | function Match_Whilem (IP : Pointer) return Boolean; | |
| 2388 | -- Return True if a WHILEM matches | |
| 2389 | ||
| 2390 | function Recurse_Match (IP : Pointer; From : Natural) return Boolean; | |
| 2391 | pragma Inline (Recurse_Match); | |
| 2392 | -- Calls Match recursively. It saves and restores the parenthesis | |
| 2393 | -- status and location in the input stream correctly, so that | |
| 2394 | -- backtracking is possible | |
| 2395 | ||
| 2396 | function Match_Simple_Operator | |
| 2397 | (Op : Opcode; | |
| 2398 | Scan : Pointer; | |
| 2399 | Next : Pointer; | |
| 2400 | Greedy : Boolean) | |
| 2401 | return Boolean; | |
| 2402 | -- Return True it the simple operator (possibly non-greedy) matches | |
| 2403 | ||
| 2404 | pragma Inline_Always (Index); | |
| 2405 | pragma Inline_Always (Repeat); | |
| 2406 | ||
| 2407 | -- These are two complex functions, but used only once. | |
| 2408 | pragma Inline_Always (Match_Whilem); | |
| 2409 | pragma Inline_Always (Match_Simple_Operator); | |
| 2410 | ||
| 2411 | ----------- | |
| 2412 | -- Index -- | |
| 2413 | ----------- | |
| 2414 | ||
| 2415 | function Index | |
| 2416 | (Start : Positive; | |
| 2417 | C : Character) | |
| 2418 | return Natural | |
| 2419 | is | |
| 2420 | begin | |
| 2421 | for J in Start .. Data'Last loop | |
| 2422 | if Data (J) = C then | |
| 2423 | return J; | |
| 2424 | end if; | |
| 2425 | end loop; | |
| 2426 | ||
| 2427 | return 0; | |
| 2428 | end Index; | |
| 2429 | ||
| 2430 | ------------------- | |
| 2431 | -- Recurse_Match -- | |
| 2432 | ------------------- | |
| 2433 | ||
| 2434 | function Recurse_Match (IP : Pointer; From : Natural) return Boolean is | |
| 2435 | L : constant Natural := Last_Paren; | |
| 2436 | Tmp_F : constant Match_Array := | |
| 2437 | Matches_Full (From + 1 .. Matches_Full'Last); | |
| 2438 | Start : constant Natural_Array := | |
| 2439 | Matches_Tmp (From + 1 .. Matches_Tmp'Last); | |
| 2440 | Input : constant Natural := Input_Pos; | |
| 2441 | begin | |
| 2442 | if Match (IP) then | |
| 2443 | return True; | |
| 2444 | end if; | |
| 2445 | Last_Paren := L; | |
| 2446 | Matches_Full (Tmp_F'Range) := Tmp_F; | |
| 2447 | Matches_Tmp (Start'Range) := Start; | |
| 2448 | Input_Pos := Input; | |
| 2449 | return False; | |
| 2450 | end Recurse_Match; | |
| 2451 | ||
| 2452 | ----------- | |
| 2453 | -- Match -- | |
| 2454 | ----------- | |
| 2455 | ||
| 2456 | function Match (IP : Pointer) return Boolean is | |
| 2457 | Scan : Pointer := IP; | |
| 2458 | Next : Pointer; | |
| 2459 | Op : Opcode; | |
| 2460 | ||
| 2461 | begin | |
| 2462 | State_Machine : | |
| 2463 | loop | |
| 2464 | pragma Assert (Scan /= 0); | |
| 2465 | ||
| 2466 | -- Determine current opcode and count its usage in debug mode | |
| 2467 | ||
| 2468 | Op := Opcode'Val (Character'Pos (Program (Scan))); | |
| 2469 | ||
| 2470 | -- Calculate offset of next instruction. | |
| 2471 | -- Second character is most significant in Program_Data. | |
| 2472 | ||
| 2473 | Next := Get_Next (Program, Scan); | |
| 2474 | ||
| 2475 | case Op is | |
| 2476 | when EOP => | |
| 2477 | return True; -- Success ! | |
| 2478 | ||
| 2479 | when BRANCH => | |
| 2480 | if Program (Next) /= BRANCH then | |
| 2481 | Next := Operand (Scan); -- No choice, avoid recursion | |
| 2482 | ||
| 2483 | else | |
| 2484 | loop | |
| 2485 | if Recurse_Match (Operand (Scan), 0) then | |
| 2486 | return True; | |
| 2487 | end if; | |
| 2488 | ||
| 2489 | Scan := Get_Next (Program, Scan); | |
| 2490 | exit when Scan = 0 or Program (Scan) /= BRANCH; | |
| 2491 | end loop; | |
| 2492 | ||
| 2493 | exit State_Machine; | |
| 2494 | end if; | |
| 2495 | ||
| 2496 | when NOTHING => | |
| 2497 | null; | |
| 2498 | ||
| 2499 | when BOL => | |
| 2500 | exit State_Machine when | |
| 2501 | Input_Pos /= BOL_Pos | |
| 2502 | and then ((Self.Flags and Multiple_Lines) = 0 | |
| 2503 | or else Data (Input_Pos - 1) /= ASCII.LF); | |
| 2504 | ||
| 2505 | when MBOL => | |
| 2506 | exit State_Machine when | |
| 2507 | Input_Pos /= BOL_Pos | |
| 2508 | and then Data (Input_Pos - 1) /= ASCII.LF; | |
| 2509 | ||
| 2510 | when SBOL => | |
| 2511 | exit State_Machine when Input_Pos /= BOL_Pos; | |
| 2512 | ||
| 2513 | when EOL => | |
| 2514 | exit State_Machine when | |
| 2515 | Input_Pos <= Data'Last | |
| 2516 | and then ((Self.Flags and Multiple_Lines) = 0 | |
| 2517 | or else Data (Input_Pos) /= ASCII.LF); | |
| 2518 | ||
| 2519 | when MEOL => | |
| 2520 | exit State_Machine when | |
| 2521 | Input_Pos <= Data'Last | |
| 2522 | and then Data (Input_Pos) /= ASCII.LF; | |
| 2523 | ||
| 2524 | when SEOL => | |
| 2525 | exit State_Machine when Input_Pos <= Data'Last; | |
| 2526 | ||
| 2527 | when BOUND | NBOUND => | |
| 2528 | ||
| 2529 | -- Was last char in word ? | |
| 2530 | ||
| 2531 | declare | |
| 2532 | N : Boolean := False; | |
| 2533 | Ln : Boolean := False; | |
| 2534 | ||
| 2535 | begin | |
| 2536 | if Input_Pos /= Data'First then | |
| 2537 | N := Is_Alnum (Data (Input_Pos - 1)); | |
| 2538 | end if; | |
| 2539 | ||
| 2540 | if Input_Pos > Data'Last then | |
| 2541 | Ln := False; | |
| 2542 | else | |
| 2543 | Ln := Is_Alnum (Data (Input_Pos)); | |
| 2544 | end if; | |
| 2545 | ||
| 2546 | if Op = BOUND then | |
| 2547 | if N = Ln then | |
| 2548 | exit State_Machine; | |
| 2549 | end if; | |
| 2550 | else | |
| 2551 | if N /= Ln then | |
| 2552 | exit State_Machine; | |
| 2553 | end if; | |
| 2554 | end if; | |
| 2555 | end; | |
| 2556 | ||
| 2557 | when SPACE => | |
| 2558 | exit State_Machine when | |
| 2559 | Input_Pos > Data'Last | |
| 2560 | or else not Is_Space (Data (Input_Pos)); | |
| 2561 | Input_Pos := Input_Pos + 1; | |
| 2562 | ||
| 2563 | when NSPACE => | |
| 2564 | exit State_Machine when | |
| 2565 | Input_Pos > Data'Last | |
| 2566 | or else Is_Space (Data (Input_Pos)); | |
| 2567 | Input_Pos := Input_Pos + 1; | |
| 2568 | ||
| 2569 | when DIGIT => | |
| 2570 | exit State_Machine when | |
| 2571 | Input_Pos > Data'Last | |
| 2572 | or else not Is_Digit (Data (Input_Pos)); | |
| 2573 | Input_Pos := Input_Pos + 1; | |
| 2574 | ||
| 2575 | when NDIGIT => | |
| 2576 | exit State_Machine when | |
| 2577 | Input_Pos > Data'Last | |
| 2578 | or else Is_Digit (Data (Input_Pos)); | |
| 2579 | Input_Pos := Input_Pos + 1; | |
| 2580 | ||
| 2581 | when ALNUM => | |
| 2582 | exit State_Machine when | |
| 2583 | Input_Pos > Data'Last | |
| 2584 | or else not Is_Alnum (Data (Input_Pos)); | |
| 2585 | Input_Pos := Input_Pos + 1; | |
| 2586 | ||
| 2587 | when NALNUM => | |
| 2588 | exit State_Machine when | |
| 2589 | Input_Pos > Data'Last | |
| 2590 | or else Is_Alnum (Data (Input_Pos)); | |
| 2591 | Input_Pos := Input_Pos + 1; | |
| 2592 | ||
| 2593 | when ANY => | |
| 2594 | exit State_Machine when Input_Pos > Data'Last | |
| 2595 | or else Data (Input_Pos) = ASCII.LF; | |
| 2596 | Input_Pos := Input_Pos + 1; | |
| 2597 | ||
| 2598 | when SANY => | |
| 2599 | exit State_Machine when Input_Pos > Data'Last; | |
| 2600 | Input_Pos := Input_Pos + 1; | |
| 2601 | ||
| 2602 | when EXACT => | |
| 2603 | declare | |
| 2604 | Opnd : Pointer := String_Operand (Scan); | |
| 2605 | Current : Positive := Input_Pos; | |
| 2606 | Last : constant Pointer := | |
| 2607 | Opnd + String_Length (Program, Scan); | |
| 2608 | ||
| 2609 | begin | |
| 2610 | while Opnd <= Last loop | |
| 2611 | exit State_Machine when Current > Data'Last | |
| 2612 | or else Program (Opnd) /= Data (Current); | |
| 2613 | Current := Current + 1; | |
| 2614 | Opnd := Opnd + 1; | |
| 2615 | end loop; | |
| 2616 | ||
| 2617 | Input_Pos := Current; | |
| 2618 | end; | |
| 2619 | ||
| 2620 | when EXACTF => | |
| 2621 | declare | |
| 2622 | Opnd : Pointer := String_Operand (Scan); | |
| 2623 | Current : Positive := Input_Pos; | |
| 2624 | Last : constant Pointer := | |
| 2625 | Opnd + String_Length (Program, Scan); | |
| 2626 | ||
| 2627 | begin | |
| 2628 | while Opnd <= Last loop | |
| 2629 | exit State_Machine when Current > Data'Last | |
| 2630 | or else Program (Opnd) /= To_Lower (Data (Current)); | |
| 2631 | Current := Current + 1; | |
| 2632 | Opnd := Opnd + 1; | |
| 2633 | end loop; | |
| 2634 | ||
| 2635 | Input_Pos := Current; | |
| 2636 | end; | |
| 2637 | ||
| 2638 | when ANYOF => | |
| 2639 | declare | |
| 2640 | Bitmap : Character_Class; | |
| 2641 | ||
| 2642 | begin | |
| 2643 | Bitmap_Operand (Program, Scan, Bitmap); | |
| 2644 | exit State_Machine when | |
| 2645 | Input_Pos > Data'Last | |
| 2646 | or else not Get_From_Class (Bitmap, Data (Input_Pos)); | |
| 2647 | Input_Pos := Input_Pos + 1; | |
| 2648 | end; | |
| 2649 | ||
| 2650 | when OPEN => | |
| 2651 | declare | |
| 2652 | No : constant Natural := | |
| 2653 | Character'Pos (Program (Operand (Scan))); | |
| 2654 | begin | |
| 2655 | Matches_Tmp (No) := Input_Pos; | |
| 2656 | end; | |
| 2657 | ||
| 2658 | when CLOSE => | |
| 2659 | declare | |
| 2660 | No : constant Natural := | |
| 2661 | Character'Pos (Program (Operand (Scan))); | |
| 2662 | begin | |
| 2663 | Matches_Full (No) := (Matches_Tmp (No), Input_Pos - 1); | |
| 2664 | if Last_Paren < No then | |
| 2665 | Last_Paren := No; | |
| 2666 | end if; | |
| 2667 | end; | |
| 2668 | ||
| 2669 | when REFF => | |
| 2670 | declare | |
| 2671 | No : constant Natural := | |
| 2672 | Character'Pos (Program (Operand (Scan))); | |
| 2673 | Data_Pos : Natural; | |
| 2674 | ||
| 2675 | begin | |
| 2676 | -- If we haven't seen that parenthesis yet | |
| 2677 | ||
| 2678 | if Last_Paren < No then | |
| 2679 | return False; | |
| 2680 | end if; | |
| 2681 | ||
| 2682 | Data_Pos := Matches_Full (No).First; | |
| 2683 | while Data_Pos <= Matches_Full (No).Last loop | |
| 2684 | if Input_Pos > Data'Last | |
| 2685 | or else Data (Input_Pos) /= Data (Data_Pos) | |
| 2686 | then | |
| 2687 | return False; | |
| 2688 | end if; | |
| 2689 | ||
| 2690 | Input_Pos := Input_Pos + 1; | |
| 2691 | Data_Pos := Data_Pos + 1; | |
| 2692 | end loop; | |
| 2693 | end; | |
| 2694 | ||
| 2695 | when MINMOD => | |
| 2696 | Greedy := False; | |
| 2697 | ||
| 2698 | when STAR | PLUS | CURLY => | |
| 2699 | declare | |
| 2700 | Greed : constant Boolean := Greedy; | |
| 2701 | begin | |
| 2702 | Greedy := True; | |
| 2703 | return Match_Simple_Operator (Op, Scan, Next, Greed); | |
| 2704 | end; | |
| 2705 | ||
| 2706 | when CURLYX => | |
| 2707 | ||
| 2708 | -- Looking at something like: | |
| 2709 | -- 1: CURLYX {n,m} (->4) | |
| 2710 | -- 2: code for complex thing (->3) | |
| 2711 | -- 3: WHILEM (->0) | |
| 2712 | -- 4: NOTHING | |
| 2713 | ||
| 2714 | declare | |
| 2715 | Cc : aliased Current_Curly_Record; | |
| 2716 | Min : Natural := Read_Natural (Program, Scan + 3); | |
| 2717 | Max : Natural := Read_Natural (Program, Scan + 5); | |
| 2718 | ||
| 2719 | Has_Match : Boolean; | |
| 2720 | ||
| 2721 | begin | |
| 2722 | Cc := (Paren_Floor => Last_Paren, | |
| 2723 | Cur => -1, | |
| 2724 | Min => Min, | |
| 2725 | Max => Max, | |
| 2726 | Greedy => Greedy, | |
| 2727 | Scan => Scan + 7, | |
| 2728 | Next => Next, | |
| 2729 | Lastloc => 0, | |
| 2730 | Old_Cc => Current_Curly); | |
| 2731 | Current_Curly := Cc'Unchecked_Access; | |
| 2732 | ||
| 2733 | Has_Match := Match (Next - 3); | |
| 2734 | ||
| 2735 | -- Start on the WHILEM | |
| 2736 | ||
| 2737 | Current_Curly := Cc.Old_Cc; | |
| 2738 | return Has_Match; | |
| 2739 | end; | |
| 2740 | ||
| 2741 | when WHILEM => | |
| 2742 | return Match_Whilem (IP); | |
| 2743 | ||
| 2744 | when others => | |
| 2745 | raise Expression_Error; -- Invalid instruction | |
| 2746 | end case; | |
| 2747 | ||
| 2748 | Scan := Next; | |
| 2749 | end loop State_Machine; | |
| 2750 | ||
| 2751 | -- If we get here, there is no match. | |
| 2752 | -- For successful matches when EOP is the terminating point. | |
| 2753 | ||
| 2754 | return False; | |
| 2755 | end Match; | |
| 2756 | ||
| 2757 | --------------------------- | |
| 2758 | -- Match_Simple_Operator -- | |
| 2759 | --------------------------- | |
| 2760 | ||
| 2761 | function Match_Simple_Operator | |
| 2762 | (Op : Opcode; | |
| 2763 | Scan : Pointer; | |
| 2764 | Next : Pointer; | |
| 2765 | Greedy : Boolean) | |
| 2766 | return Boolean | |
| 2767 | is | |
| 2768 | Next_Char : Character := ASCII.Nul; | |
| 2769 | Next_Char_Known : Boolean := False; | |
| 2770 | No : Integer; -- Can be negative | |
| 2771 | Min : Natural; | |
| 2772 | Max : Natural := Natural'Last; | |
| 2773 | Operand_Code : Pointer; | |
| 2774 | Old : Natural; | |
| 2775 | Last_Pos : Natural; | |
| 2776 | Save : Natural := Input_Pos; | |
| 2777 | ||
| 2778 | begin | |
| 2779 | -- Lookahead to avoid useless match attempts | |
| 2780 | -- when we know what character comes next. | |
| 2781 | ||
| 2782 | if Program (Next) = EXACT then | |
| 2783 | Next_Char := Program (String_Operand (Next)); | |
| 2784 | Next_Char_Known := True; | |
| 2785 | end if; | |
| 2786 | ||
| 2787 | -- Find the minimal and maximal values for the operator | |
| 2788 | ||
| 2789 | case Op is | |
| 2790 | when STAR => | |
| 2791 | Min := 0; | |
| 2792 | Operand_Code := Operand (Scan); | |
| 2793 | ||
| 2794 | when PLUS => | |
| 2795 | Min := 1; | |
| 2796 | Operand_Code := Operand (Scan); | |
| 2797 | ||
| 2798 | when others => | |
| 2799 | Min := Read_Natural (Program, Scan + 3); | |
| 2800 | Max := Read_Natural (Program, Scan + 5); | |
| 2801 | Operand_Code := Scan + 7; | |
| 2802 | end case; | |
| 2803 | ||
| 2804 | -- Non greedy operators | |
| 2805 | ||
| 2806 | if not Greedy then | |
| 2807 | -- Test the minimal repetitions | |
| 2808 | ||
| 2809 | if Min /= 0 | |
| 2810 | and then Repeat (Operand_Code, Min) < Min | |
| 2811 | then | |
| 2812 | return False; | |
| 2813 | end if; | |
| 2814 | ||
| 2815 | Old := Input_Pos; | |
| 2816 | ||
| 2817 | -- Find the place where 'next' could work | |
| 2818 | ||
| 2819 | if Next_Char_Known then | |
| 2820 | -- Last position to check | |
| 2821 | ||
| 2822 | Last_Pos := Input_Pos + Max; | |
| 2823 | ||
| 2824 | if Last_Pos > Data'Last | |
| 2825 | or else Max = Natural'Last | |
| 2826 | then | |
| 2827 | Last_Pos := Data'Last; | |
| 2828 | end if; | |
| 2829 | ||
| 2830 | -- Look for the first possible opportunity | |
| 2831 | ||
| 2832 | loop | |
| 2833 | -- Find the next possible position | |
| 2834 | ||
| 2835 | while Input_Pos <= Last_Pos | |
| 2836 | and then Data (Input_Pos) /= Next_Char | |
| 2837 | loop | |
| 2838 | Input_Pos := Input_Pos + 1; | |
| 2839 | end loop; | |
| 2840 | ||
| 2841 | if Input_Pos > Last_Pos then | |
| 2842 | return False; | |
| 2843 | end if; | |
| 2844 | ||
| 2845 | -- Check that we still match if we stop | |
| 2846 | -- at the position we just found. | |
| 2847 | ||
| 2848 | declare | |
| 2849 | Num : constant Natural := Input_Pos - Old; | |
| 2850 | ||
| 2851 | begin | |
| 2852 | Input_Pos := Old; | |
| 2853 | ||
| 2854 | if Repeat (Operand_Code, Num) < Num then | |
| 2855 | return False; | |
| 2856 | end if; | |
| 2857 | end; | |
| 2858 | ||
| 2859 | -- Input_Pos now points to the new position | |
| 2860 | ||
| 2861 | if Match (Get_Next (Program, Scan)) then | |
| 2862 | return True; | |
| 2863 | end if; | |
| 2864 | ||
| 2865 | Old := Input_Pos; | |
| 2866 | Input_Pos := Input_Pos + 1; | |
| 2867 | end loop; | |
| 2868 | ||
| 2869 | -- We know what the next character is | |
| 2870 | ||
| 2871 | else | |
| 2872 | while Max >= Min loop | |
| 2873 | ||
| 2874 | -- If the next character matches | |
| 2875 | ||
| 2876 | if Match (Next) then | |
| 2877 | return True; | |
| 2878 | end if; | |
| 2879 | ||
| 2880 | Input_Pos := Save + Min; | |
| 2881 | ||
| 2882 | -- Could not or did not match -- move forward | |
| 2883 | ||
| 2884 | if Repeat (Operand_Code, 1) /= 0 then | |
| 2885 | Min := Min + 1; | |
| 2886 | else | |
| 2887 | return False; | |
| 2888 | end if; | |
| 2889 | end loop; | |
| 2890 | end if; | |
| 2891 | ||
| 2892 | return False; | |
| 2893 | ||
| 2894 | -- Greedy operators | |
| 2895 | ||
| 2896 | else | |
| 2897 | No := Repeat (Operand_Code, Max); | |
| 2898 | ||
| 2899 | -- ??? Perl has some special code here in case the | |
| 2900 | -- next instruction is of type EOL, since $ and \Z | |
| 2901 | -- can match before *and* after newline at the end. | |
| 2902 | ||
| 2903 | -- ??? Perl has some special code here in case (paren) | |
| 2904 | -- is True. | |
| 2905 | ||
| 2906 | -- Else, if we don't have any parenthesis | |
| 2907 | ||
| 2908 | while No >= Min loop | |
| 2909 | if not Next_Char_Known | |
| 2910 | or else (Input_Pos <= Data'Last | |
| 2911 | and then Data (Input_Pos) = Next_Char) | |
| 2912 | then | |
| 2913 | if Match (Next) then | |
| 2914 | return True; | |
| 2915 | end if; | |
| 2916 | end if; | |
| 2917 | ||
| 2918 | -- Could not or did not work, we back up | |
| 2919 | ||
| 2920 | No := No - 1; | |
| 2921 | Input_Pos := Save + No; | |
| 2922 | end loop; | |
| 2923 | return False; | |
| 2924 | end if; | |
| 2925 | end Match_Simple_Operator; | |
| 2926 | ||
| 2927 | ------------------ | |
| 2928 | -- Match_Whilem -- | |
| 2929 | ------------------ | |
| 2930 | ||
| 2931 | -- This is really hard to understand, because after we match what we're | |
| 2932 | -- trying to match, we must make sure the rest of the REx is going to | |
| 2933 | -- match for sure, and to do that we have to go back UP the parse tree | |
| 2934 | -- by recursing ever deeper. And if it fails, we have to reset our | |
| 2935 | -- parent's current state that we can try again after backing off. | |
| 2936 | ||
| 2937 | function Match_Whilem (IP : Pointer) return Boolean is | |
| 2938 | Cc : Current_Curly_Access := Current_Curly; | |
| 2939 | N : Natural := Cc.Cur + 1; | |
| 2940 | Ln : Natural; | |
| 2941 | Lastloc : Natural := Cc.Lastloc; | |
| 2942 | -- Detection of 0-len. | |
| 2943 | ||
| 2944 | begin | |
| 2945 | -- If degenerate scan matches "", assume scan done. | |
| 2946 | ||
| 2947 | if Input_Pos = Cc.Lastloc | |
| 2948 | and then N >= Cc.Min | |
| 2949 | then | |
| 2950 | -- Temporarily restore the old context, and check that we | |
| 2951 | -- match was comes after CURLYX. | |
| 2952 | ||
| 2953 | Current_Curly := Cc.Old_Cc; | |
| 2954 | ||
| 2955 | if Current_Curly /= null then | |
| 2956 | Ln := Current_Curly.Cur; | |
| 2957 | end if; | |
| 2958 | ||
| 2959 | if Match (Cc.Next) then | |
| 2960 | return True; | |
| 2961 | end if; | |
| 2962 | ||
| 2963 | if Current_Curly /= null then | |
| 2964 | Current_Curly.Cur := Ln; | |
| 2965 | end if; | |
| 2966 | ||
| 2967 | Current_Curly := Cc; | |
| 2968 | return False; | |
| 2969 | end if; | |
| 2970 | ||
| 2971 | -- First, just match a string of min scans. | |
| 2972 | ||
| 2973 | if N < Cc.Min then | |
| 2974 | Cc.Cur := N; | |
| 2975 | Cc.Lastloc := Input_Pos; | |
| 2976 | ||
| 2977 | if Match (Cc.Scan) then | |
| 2978 | return True; | |
| 2979 | end if; | |
| 2980 | ||
| 2981 | Cc.Cur := N - 1; | |
| 2982 | Cc.Lastloc := Lastloc; | |
| 2983 | return False; | |
| 2984 | end if; | |
| 2985 | ||
| 2986 | -- Prefer next over scan for minimal matching. | |
| 2987 | ||
| 2988 | if not Cc.Greedy then | |
| 2989 | Current_Curly := Cc.Old_Cc; | |
| 2990 | ||
| 2991 | if Current_Curly /= null then | |
| 2992 | Ln := Current_Curly.Cur; | |
| 2993 | end if; | |
| 2994 | ||
| 2995 | if Recurse_Match (Cc.Next, Cc.Paren_Floor) then | |
| 2996 | return True; | |
| 2997 | end if; | |
| 2998 | ||
| 2999 | if Current_Curly /= null then | |
| 3000 | Current_Curly.Cur := Ln; | |
| 3001 | end if; | |
| 3002 | ||
| 3003 | Current_Curly := Cc; | |
| 3004 | ||
| 3005 | -- Maximum greed exceeded ? | |
| 3006 | ||
| 3007 | if N >= Cc.Max then | |
| 3008 | return False; | |
| 3009 | end if; | |
| 3010 | ||
| 3011 | -- Try scanning more and see if it helps | |
| 3012 | Cc.Cur := N; | |
| 3013 | Cc.Lastloc := Input_Pos; | |
| 3014 | ||
| 3015 | if Recurse_Match (Cc.Scan, Cc.Paren_Floor) then | |
| 3016 | return True; | |
| 3017 | end if; | |
| 3018 | ||
| 3019 | Cc.Cur := N - 1; | |
| 3020 | Cc.Lastloc := Lastloc; | |
| 3021 | return False; | |
| 3022 | end if; | |
| 3023 | ||
| 3024 | -- Prefer scan over next for maximal matching | |
| 3025 | ||
| 3026 | if N < Cc.Max then -- more greed allowed ? | |
| 3027 | Cc.Cur := N; | |
| 3028 | Cc.Lastloc := Input_Pos; | |
| 3029 | ||
| 3030 | if Recurse_Match (Cc.Scan, Cc.Paren_Floor) then | |
| 3031 | return True; | |
| 3032 | end if; | |
| 3033 | end if; | |
| 3034 | ||
| 3035 | -- Failed deeper matches of scan, so see if this one works | |
| 3036 | ||
| 3037 | Current_Curly := Cc.Old_Cc; | |
| 3038 | ||
| 3039 | if Current_Curly /= null then | |
| 3040 | Ln := Current_Curly.Cur; | |
| 3041 | end if; | |
| 3042 | ||
| 3043 | if Match (Cc.Next) then | |
| 3044 | return True; | |
| 3045 | end if; | |
| 3046 | ||
| 3047 | if Current_Curly /= null then | |
| 3048 | Current_Curly.Cur := Ln; | |
| 3049 | end if; | |
| 3050 | ||
| 3051 | Current_Curly := Cc; | |
| 3052 | Cc.Cur := N - 1; | |
| 3053 | Cc.Lastloc := Lastloc; | |
| 3054 | return False; | |
| 3055 | end Match_Whilem; | |
| 3056 | ||
| 3057 | ------------ | |
| 3058 | -- Repeat -- | |
| 3059 | ------------ | |
| 3060 | ||
| 3061 | function Repeat | |
| 3062 | (IP : Pointer; | |
| 3063 | Max : Natural := Natural'Last) | |
| 3064 | return Natural | |
| 3065 | is | |
| 3066 | Scan : Natural := Input_Pos; | |
| 3067 | Last : Natural; | |
| 3068 | Op : constant Opcode := Opcode'Val (Character'Pos (Program (IP))); | |
| 3069 | Count : Natural; | |
| 3070 | C : Character; | |
| 3071 | Is_First : Boolean := True; | |
| 3072 | Bitmap : Character_Class; | |
| 3073 | ||
| 3074 | begin | |
| 3075 | if Max = Natural'Last or else Scan + Max - 1 > Data'Last then | |
| 3076 | Last := Data'Last; | |
| 3077 | else | |
| 3078 | Last := Scan + Max - 1; | |
| 3079 | end if; | |
| 3080 | ||
| 3081 | case Op is | |
| 3082 | when ANY => | |
| 3083 | while Scan <= Last | |
| 3084 | and then Data (Scan) /= ASCII.LF | |
| 3085 | loop | |
| 3086 | Scan := Scan + 1; | |
| 3087 | end loop; | |
| 3088 | ||
| 3089 | when SANY => | |
| 3090 | Scan := Last + 1; | |
| 3091 | ||
| 3092 | when EXACT => | |
| 3093 | ||
| 3094 | -- The string has only one character if Repeat was called | |
| 3095 | ||
| 3096 | C := Program (String_Operand (IP)); | |
| 3097 | while Scan <= Last | |
| 3098 | and then C = Data (Scan) | |
| 3099 | loop | |
| 3100 | Scan := Scan + 1; | |
| 3101 | end loop; | |
| 3102 | ||
| 3103 | when EXACTF => | |
| 3104 | ||
| 3105 | -- The string has only one character if Repeat was called | |
| 3106 | ||
| 3107 | C := Program (String_Operand (IP)); | |
| 3108 | while Scan <= Last | |
| 3109 | and then To_Lower (C) = Data (Scan) | |
| 3110 | loop | |
| 3111 | Scan := Scan + 1; | |
| 3112 | end loop; | |
| 3113 | ||
| 3114 | when ANYOF => | |
| 3115 | if Is_First then | |
| 3116 | Bitmap_Operand (Program, IP, Bitmap); | |
| 3117 | Is_First := False; | |
| 3118 | end if; | |
| 3119 | ||
| 3120 | while Scan <= Last | |
| 3121 | and then Get_From_Class (Bitmap, Data (Scan)) | |
| 3122 | loop | |
| 3123 | Scan := Scan + 1; | |
| 3124 | end loop; | |
| 3125 | ||
| 3126 | when ALNUM => | |
| 3127 | while Scan <= Last | |
| 3128 | and then Is_Alnum (Data (Scan)) | |
| 3129 | loop | |
| 3130 | Scan := Scan + 1; | |
| 3131 | end loop; | |
| 3132 | ||
| 3133 | when NALNUM => | |
| 3134 | while Scan <= Last | |
| 3135 | and then not Is_Alnum (Data (Scan)) | |
| 3136 | loop | |
| 3137 | Scan := Scan + 1; | |
| 3138 | end loop; | |
| 3139 | ||
| 3140 | when SPACE => | |
| 3141 | while Scan <= Last | |
| 3142 | and then Is_Space (Data (Scan)) | |
| 3143 | loop | |
| 3144 | Scan := Scan + 1; | |
| 3145 | end loop; | |
| 3146 | ||
| 3147 | when NSPACE => | |
| 3148 | while Scan <= Last | |
| 3149 | and then not Is_Space (Data (Scan)) | |
| 3150 | loop | |
| 3151 | Scan := Scan + 1; | |
| 3152 | end loop; | |
| 3153 | ||
| 3154 | when DIGIT => | |
| 3155 | while Scan <= Last | |
| 3156 | and then Is_Digit (Data (Scan)) | |
| 3157 | loop | |
| 3158 | Scan := Scan + 1; | |
| 3159 | end loop; | |
| 3160 | ||
| 3161 | when NDIGIT => | |
| 3162 | while Scan <= Last | |
| 3163 | and then not Is_Digit (Data (Scan)) | |
| 3164 | loop | |
| 3165 | Scan := Scan + 1; | |
| 3166 | end loop; | |
| 3167 | ||
| 3168 | when others => | |
| 3169 | raise Program_Error; | |
| 3170 | end case; | |
| 3171 | ||
| 3172 | Count := Scan - Input_Pos; | |
| 3173 | Input_Pos := Scan; | |
| 3174 | return Count; | |
| 3175 | end Repeat; | |
| 3176 | ||
| 3177 | --------- | |
| 3178 | -- Try -- | |
| 3179 | --------- | |
| 3180 | ||
| 3181 | function Try (Pos : in Positive) return Boolean is | |
| 3182 | begin | |
| 3183 | Input_Pos := Pos; | |
| 3184 | Last_Paren := 0; | |
| 3185 | Matches_Full := (others => No_Match); | |
| 3186 | ||
| 3187 | if Match (Program_First + 1) then | |
| 3188 | Matches_Full (0) := (Pos, Input_Pos - 1); | |
| 3189 | return True; | |
| 3190 | end if; | |
| 3191 | ||
| 3192 | return False; | |
| 3193 | end Try; | |
| 3194 | ||
| 3195 | -- Start of processing for Match | |
| 3196 | ||
| 3197 | begin | |
| 3198 | -- Do we have the regexp Never_Match? | |
| 3199 | ||
| 3200 | if Self.Size = 0 then | |
| 3201 | Matches (0) := No_Match; | |
| 3202 | return; | |
| 3203 | end if; | |
| 3204 | ||
| 3205 | -- Check validity of program | |
| 3206 | ||
| 3207 | pragma Assert | |
| 3208 | (Program (Program_First) = MAGIC, | |
| 3209 | "Corrupted Pattern_Matcher"); | |
| 3210 | ||
| 3211 | -- If there is a "must appear" string, look for it | |
| 3212 | ||
| 3213 | if Self.Must_Have_Length > 0 then | |
| 3214 | declare | |
| 3215 | First : constant Character := Program (Self.Must_Have); | |
| 3216 | Must_First : constant Pointer := Self.Must_Have; | |
| 3217 | Must_Last : constant Pointer := | |
| 3218 | Must_First + Pointer (Self.Must_Have_Length - 1); | |
| 3219 | Next_Try : Natural := Index (Data'First, First); | |
| 3220 | ||
| 3221 | begin | |
| 3222 | while Next_Try /= 0 | |
| 3223 | and then Data (Next_Try .. Next_Try + Self.Must_Have_Length - 1) | |
| 3224 | = String (Program (Must_First .. Must_Last)) | |
| 3225 | loop | |
| 3226 | Next_Try := Index (Next_Try + 1, First); | |
| 3227 | end loop; | |
| 3228 | ||
| 3229 | if Next_Try = 0 then | |
| 3230 | Matches_Full := (others => No_Match); | |
| 3231 | return; -- Not present | |
| 3232 | end if; | |
| 3233 | end; | |
| 3234 | end if; | |
| 3235 | ||
| 3236 | -- Mark beginning of line for ^ | |
| 3237 | ||
| 3238 | BOL_Pos := Data'First; | |
| 3239 | ||
| 3240 | -- Simplest case first: an anchored match need be tried only once | |
| 3241 | ||
| 3242 | if Self.Anchored and then (Self.Flags and Multiple_Lines) = 0 then | |
| 3243 | Matched := Try (Data'First); | |
| 3244 | ||
| 3245 | elsif Self.Anchored then | |
| 3246 | declare | |
| 3247 | Next_Try : Natural := Data'First; | |
| 3248 | begin | |
| 3249 | -- Test the first position in the buffer | |
| 3250 | Matched := Try (Next_Try); | |
| 3251 | ||
| 3252 | -- Else only test after newlines | |
| 3253 | ||
| 3254 | if not Matched then | |
| 3255 | while Next_Try <= Data'Last loop | |
| 3256 | while Next_Try <= Data'Last | |
| 3257 | and then Data (Next_Try) /= ASCII.LF | |
| 3258 | loop | |
| 3259 | Next_Try := Next_Try + 1; | |
| 3260 | end loop; | |
| 3261 | ||
| 3262 | Next_Try := Next_Try + 1; | |
| 3263 | ||
| 3264 | if Next_Try <= Data'Last then | |
| 3265 | Matched := Try (Next_Try); | |
| 3266 | exit when Matched; | |
| 3267 | end if; | |
| 3268 | end loop; | |
| 3269 | end if; | |
| 3270 | end; | |
| 3271 | ||
| 3272 | elsif Self.First /= ASCII.NUL then | |
| 3273 | ||
| 3274 | -- We know what char it must start with | |
| 3275 | ||
| 3276 | declare | |
| 3277 | Next_Try : Natural := Index (Data'First, Self.First); | |
| 3278 | ||
| 3279 | begin | |
| 3280 | while Next_Try /= 0 loop | |
| 3281 | Matched := Try (Next_Try); | |
| 3282 | exit when Matched; | |
| 3283 | Next_Try := Index (Next_Try + 1, Self.First); | |
| 3284 | end loop; | |
| 3285 | end; | |
| 3286 | ||
| 3287 | else | |
| 3288 | -- Messy cases: try all locations (including for the empty string) | |
| 3289 | ||
| 3290 | Matched := Try (Data'First); | |
| 3291 | ||
| 3292 | if not Matched then | |
| 3293 | for S in Data'First + 1 .. Data'Last loop | |
| 3294 | Matched := Try (S); | |
| 3295 | exit when Matched; | |
| 3296 | end loop; | |
| 3297 | end if; | |
| 3298 | end if; | |
| 3299 | ||
| 3300 | -- Matched has its value | |
| 3301 | ||
| 3302 | for J in Last_Paren + 1 .. Matches'Last loop | |
| 3303 | Matches_Full (J) := No_Match; | |
| 3304 | end loop; | |
| 3305 | ||
| 3306 | Matches := Matches_Full (Matches'Range); | |
| 3307 | return; | |
| 3308 | end Match; | |
| 3309 | ||
| 3310 | function Match | |
| 3311 | (Self : Pattern_Matcher; | |
| 3312 | Data : String) | |
| 3313 | return Natural | |
| 3314 | is | |
| 3315 | Matches : Match_Array (0 .. 0); | |
| 3316 | ||
| 3317 | begin | |
| 3318 | Match (Self, Data, Matches); | |
| 3319 | if Matches (0) = No_Match then | |
| 3320 | return Data'First - 1; | |
| 3321 | else | |
| 3322 | return Matches (0).First; | |
| 3323 | end if; | |
| 3324 | end Match; | |
| 3325 | ||
| 3326 | procedure Match | |
| 3327 | (Expression : String; | |
| 3328 | Data : String; | |
| 3329 | Matches : out Match_Array; | |
| 3330 | Size : Program_Size := 0) | |
| 3331 | is | |
| 3332 | PM : Pattern_Matcher (Size); | |
| 3333 | Finalize_Size : Program_Size; | |
| 3334 | ||
| 3335 | begin | |
| 3336 | if Size = 0 then | |
| 3337 | Match (Compile (Expression), Data, Matches); | |
| 3338 | else | |
| 3339 | Compile (PM, Expression, Finalize_Size); | |
| 3340 | Match (PM, Data, Matches); | |
| 3341 | end if; | |
| 3342 | end Match; | |
| 3343 | ||
| 3344 | function Match | |
| 3345 | (Expression : String; | |
| 3346 | Data : String; | |
| 3347 | Size : Program_Size := 0) | |
| 3348 | return Natural | |
| 3349 | is | |
| 3350 | PM : Pattern_Matcher (Size); | |
| 3351 | Final_Size : Program_Size; -- unused | |
| 3352 | ||
| 3353 | begin | |
| 3354 | if Size = 0 then | |
| 3355 | return Match (Compile (Expression), Data); | |
| 3356 | else | |
| 3357 | Compile (PM, Expression, Final_Size); | |
| 3358 | return Match (PM, Data); | |
| 3359 | end if; | |
| 3360 | end Match; | |
| 3361 | ||
| 3362 | function Match | |
| 3363 | (Expression : String; | |
| 3364 | Data : String; | |
| 3365 | Size : Program_Size := 0) | |
| 3366 | return Boolean | |
| 3367 | is | |
| 3368 | Matches : Match_Array (0 .. 0); | |
| 3369 | PM : Pattern_Matcher (Size); | |
| 3370 | Final_Size : Program_Size; -- unused | |
| 3371 | ||
| 3372 | begin | |
| 3373 | if Size = 0 then | |
| 3374 | Match (Compile (Expression), Data, Matches); | |
| 3375 | else | |
| 3376 | Compile (PM, Expression, Final_Size); | |
| 3377 | Match (PM, Data, Matches); | |
| 3378 | end if; | |
| 3379 | ||
| 3380 | return Matches (0).First >= Data'First; | |
| 3381 | end Match; | |
| 3382 | ||
| 3383 | ------------- | |
| 3384 | -- Operand -- | |
| 3385 | ------------- | |
| 3386 | ||
| 3387 | function Operand (P : Pointer) return Pointer is | |
| 3388 | begin | |
| 3389 | return P + 3; | |
| 3390 | end Operand; | |
| 3391 | ||
| 3392 | -------------- | |
| 3393 | -- Optimize -- | |
| 3394 | -------------- | |
| 3395 | ||
| 3396 | procedure Optimize (Self : in out Pattern_Matcher) is | |
| 3397 | Max_Length : Program_Size; | |
| 3398 | This_Length : Program_Size; | |
| 3399 | Longest : Pointer; | |
| 3400 | Scan : Pointer; | |
| 3401 | Program : Program_Data renames Self.Program; | |
| 3402 | ||
| 3403 | begin | |
| 3404 | -- Start with safe defaults (no optimization): | |
| 3405 | -- * No known first character of match | |
| 3406 | -- * Does not necessarily start at beginning of line | |
| 3407 | -- * No string known that has to appear in data | |
| 3408 | ||
| 3409 | Self.First := ASCII.NUL; | |
| 3410 | Self.Anchored := False; | |
| 3411 | Self.Must_Have := Program'Last + 1; | |
| 3412 | Self.Must_Have_Length := 0; | |
| 3413 | ||
| 3414 | Scan := Program_First + 1; -- First instruction (can be anything) | |
| 3415 | ||
| 3416 | if Program (Scan) = EXACT then | |
| 3417 | Self.First := Program (String_Operand (Scan)); | |
| 3418 | ||
| 3419 | elsif Program (Scan) = BOL | |
| 3420 | or else Program (Scan) = SBOL | |
| 3421 | or else Program (Scan) = MBOL | |
| 3422 | then | |
| 3423 | Self.Anchored := True; | |
| 3424 | end if; | |
| 3425 | ||
| 3426 | -- If there's something expensive in the regexp, find the | |
| 3427 | -- longest literal string that must appear and make it the | |
| 3428 | -- regmust. Resolve ties in favor of later strings, since | |
| 3429 | -- the regstart check works with the beginning of the regexp. | |
| 3430 | -- and avoiding duplication strengthens checking. Not a | |
| 3431 | -- strong reason, but sufficient in the absence of others. | |
| 3432 | ||
| 3433 | if False then -- if Flags.SP_Start then ??? | |
| 3434 | Longest := 0; | |
| 3435 | Max_Length := 0; | |
| 3436 | while Scan /= 0 loop | |
| 3437 | if Program (Scan) = EXACT or else Program (Scan) = EXACTF then | |
| 3438 | This_Length := String_Length (Program, Scan); | |
| 3439 | ||
| 3440 | if This_Length >= Max_Length then | |
| 3441 | Longest := String_Operand (Scan); | |
| 3442 | Max_Length := This_Length; | |
| 3443 | end if; | |
| 3444 | end if; | |
| 3445 | ||
| 3446 | Scan := Get_Next (Program, Scan); | |
| 3447 | end loop; | |
| 3448 | ||
| 3449 | Self.Must_Have := Longest; | |
| 3450 | Self.Must_Have_Length := Natural (Max_Length) + 1; | |
| 3451 | end if; | |
| 3452 | end Optimize; | |
| 3453 | ||
| 3454 | ----------------- | |
| 3455 | -- Paren_Count -- | |
| 3456 | ----------------- | |
| 3457 | ||
| 3458 | function Paren_Count (Regexp : Pattern_Matcher) return Match_Count is | |
| 3459 | begin | |
| 3460 | return Regexp.Paren_Count; | |
| 3461 | end Paren_Count; | |
| 3462 | ||
| 3463 | ----------- | |
| 3464 | -- Quote -- | |
| 3465 | ----------- | |
| 3466 | ||
| 3467 | function Quote (Str : String) return String is | |
| 3468 | S : String (1 .. Str'Length * 2); | |
| 3469 | Last : Natural := 0; | |
| 3470 | ||
| 3471 | begin | |
| 3472 | for J in Str'Range loop | |
| 3473 | case Str (J) is | |
| 3474 | when '^' | '$' | '|' | '*' | '+' | '?' | '{' | |
| 3475 | | '}' | '[' | ']' | '(' | ')' | '\' => | |
| 3476 | ||
| 3477 | S (Last + 1) := '\'; | |
| 3478 | S (Last + 2) := Str (J); | |
| 3479 | Last := Last + 2; | |
| 3480 | ||
| 3481 | when others => | |
| 3482 | S (Last + 1) := Str (J); | |
| 3483 | Last := Last + 1; | |
| 3484 | end case; | |
| 3485 | end loop; | |
| 3486 | ||
| 3487 | return S (1 .. Last); | |
| 3488 | end Quote; | |
| 3489 | ||
| 3490 | ------------------ | |
| 3491 | -- Read_Natural -- | |
| 3492 | ------------------ | |
| 3493 | ||
| 3494 | function Read_Natural | |
| 3495 | (Program : Program_Data; | |
| 3496 | IP : Pointer) | |
| 3497 | return Natural | |
| 3498 | is | |
| 3499 | begin | |
| 3500 | return Character'Pos (Program (IP)) + | |
| 3501 | 256 * Character'Pos (Program (IP + 1)); | |
| 3502 | end Read_Natural; | |
| 3503 | ||
| 3504 | ----------------- | |
| 3505 | -- Reset_Class -- | |
| 3506 | ----------------- | |
| 3507 | ||
| 3508 | procedure Reset_Class (Bitmap : in out Character_Class) is | |
| 3509 | begin | |
| 3510 | Bitmap := (others => 0); | |
| 3511 | end Reset_Class; | |
| 3512 | ||
| 3513 | ------------------ | |
| 3514 | -- Set_In_Class -- | |
| 3515 | ------------------ | |
| 3516 | ||
| 3517 | procedure Set_In_Class | |
| 3518 | (Bitmap : in out Character_Class; | |
| 3519 | C : Character) | |
| 3520 | is | |
| 3521 | Value : constant Class_Byte := Character'Pos (C); | |
| 3522 | ||
| 3523 | begin | |
| 3524 | Bitmap (Value / 8) := Bitmap (Value / 8) | |
| 3525 | or Bit_Conversion (Value mod 8); | |
| 3526 | end Set_In_Class; | |
| 3527 | ||
| 3528 | ------------------- | |
| 3529 | -- String_Length -- | |
| 3530 | ------------------- | |
| 3531 | ||
| 3532 | function String_Length | |
| 3533 | (Program : Program_Data; | |
| 3534 | P : Pointer) | |
| 3535 | return Program_Size | |
| 3536 | is | |
| 3537 | begin | |
| 3538 | pragma Assert (Program (P) = EXACT or else Program (P) = EXACTF); | |
| 3539 | return Character'Pos (Program (P + 3)); | |
| 3540 | end String_Length; | |
| 3541 | ||
| 3542 | -------------------- | |
| 3543 | -- String_Operand -- | |
| 3544 | -------------------- | |
| 3545 | ||
| 3546 | function String_Operand (P : Pointer) return Pointer is | |
| 3547 | begin | |
| 3548 | return P + 4; | |
| 3549 | end String_Operand; | |
| 3550 | ||
| 3551 | end GNAT.Regpat; |