src/scan-gram.l

   1 /* Bison Grammar Scanner                             -*- C -*-
   2    Copyright (C) 2002 Free Software Foundation, Inc.
   3
   4    This file is part of Bison, the GNU Compiler Compiler.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307  USA
  20 */
  21
  22 %option debug nodefault noyywrap nounput never-interactive stack
  23 %option prefix="gram_" outfile="lex.yy.c"
  24
  25 %{
  26 #include "system.h"
  27 #include "complain.h"
  28 #include "quote.h"
  29 #include "getargs.h"
  30 #include "gram.h"
  31 #include "reader.h"
  32
  33 /* Each time we match a string, move the end cursor to its end. */
  34 #define YY_USER_INIT                            \
  35 do {                                            \
  36   LOCATION_RESET (*yylloc);                     \
  37    /* This is only to avoid GCC warnings. */    \
  38   if (yycontrol) {;};                           \
  39 } while (0)
  40
  41 #define YY_USER_ACTION  LOCATION_COLUMNS (*yylloc, yyleng)
  42 #define YY_LINES        LOCATION_LINES (*yylloc, yyleng); lineno += yyleng;
  43 #define YY_STEP         LOCATION_STEP (*yylloc)
  44
  45
  46 /* STRING_OBSTACK -- Used to store all the characters that we need to
  47    keep (to construct ID, STRINGS etc.).  Use the following macros to
  48    use it.
  49
  50    Use YY_OBS_GROW to append what has just been matched, and
  51    YY_OBS_FINISH to end the string (it puts the ending 0).
  52    YY_OBS_FINISH also stores this string in LAST_STRING, which can be
  53    used, and which is used by YY_OBS_FREE to free the last string.  */
  54
  55 static struct obstack string_obstack;
  56 char *last_string;
  57
  58 #define YY_OBS_GROW   \
  59   obstack_grow (&string_obstack, yytext, yyleng)
  60
  61 #define YY_OBS_FINISH                                   \
  62   do {                                                  \
  63     obstack_1grow (&string_obstack, '\0');              \
  64     last_string = obstack_finish (&string_obstack);     \
  65   } while (0)
  66
  67 #define YY_OBS_FREE                                             \
  68   do {                                                          \
  69     obstack_free (&string_obstack, last_string);                \
  70   } while (0)
  71
  72 void
  73 scanner_last_string_free (void)
  74 {
  75   YY_OBS_FREE;
  76 }
  77
  78
  79 static int braces_level = 0;
  80 static int percent_percent_count = 0;
  81
  82 static void handle_dollar PARAMS ((braced_code_t code_kind,
  83                                    char *cp, location_t location));
  84 static void handle_at PARAMS ((braced_code_t code_kind,
  85                                char *cp, location_t location));
  86
  87 %}
  88 %x SC_COMMENT
  89 %x SC_STRING SC_CHARACTER
  90 %x SC_ESCAPED_STRING SC_ESCAPED_CHARACTER
  91 %x SC_BRACED_CODE SC_PROLOGUE SC_EPILOGUE
  92
  93 id       [.a-zA-Z][.a-zA-Z_0-9]*
  94 int      [0-9]+
  95 eols     (\n|\r|\n\r|\r\n)+
  96 blanks   [ \t\f]+
  97
  98 %%
  99 %{
 100   /* At each yylex invocation, mark the current position as the
 101      start of the next token.  */
 102 #define TR_POS 0
 103 #if TR_POS
 104   fprintf (stderr, "FOO1: %p: ", yylloc);
 105   LOCATION_PRINT (stderr, *yylloc);
 106   fprintf (stderr, "\n");
 107 #endif
 108   YY_STEP;
 109 #if TR_POS
 110   fprintf (stderr, "BAR1: ");
 111   LOCATION_PRINT (stderr, *yylloc);
 112   fprintf (stderr, "\n");
 113 #endif
 114 %}
 115
 116
 117   /*----------------------------.
 118   | Scanning Bison directives.  |
 119   `----------------------------*/
 120 <INITIAL>
 121 {
 122   "%binary"               return PERCENT_NONASSOC;
 123   "%debug"                return PERCENT_DEBUG;
 124   "%define"               return PERCENT_DEFINE;
 125   "%defines"              return PERCENT_DEFINES;
 126   "%destructor"           return PERCENT_DESTRUCTOR;
 127   "%dprec"                return PERCENT_DPREC;
 128   "%error"[-_]"verbose"   return PERCENT_ERROR_VERBOSE;
 129   "%expect"               return PERCENT_EXPECT;
 130   "%file-prefix"          return PERCENT_FILE_PREFIX;
 131   "%fixed"[-_]"output"[-_]"files"   return PERCENT_YACC;
 132   "%glr"[-_]"parser"      return PERCENT_GLR_PARSER;
 133   "%left"                 return PERCENT_LEFT;
 134   "%locations"            return PERCENT_LOCATIONS;
 135   "%merge"                return PERCENT_MERGE;
 136   "%name"[-_]"prefix"     return PERCENT_NAME_PREFIX;
 137   "%no"[-_]"lines"        return PERCENT_NO_LINES;
 138   "%nonassoc"             return PERCENT_NONASSOC;
 139   "%nterm"                return PERCENT_NTERM;
 140   "%output"               return PERCENT_OUTPUT;
 141   "%prec"                 return PERCENT_PREC;
 142   "%printer"              return PERCENT_PRINTER;
 143   "%pure"[-_]"parser"     return PERCENT_PURE_PARSER;
 144   "%right"                return PERCENT_RIGHT;
 145   "%skeleton"             return PERCENT_SKELETON;
 146   "%start"                return PERCENT_START;
 147   "%term"                 return PERCENT_TOKEN;
 148   "%token"                return PERCENT_TOKEN;
 149   "%token"[-_]"table"     return PERCENT_TOKEN_TABLE;
 150   "%type"                 return PERCENT_TYPE;
 151   "%union"                return PERCENT_UNION;
 152   "%verbose"              return PERCENT_VERBOSE;
 153   "%yacc"                 return PERCENT_YACC;
 154
 155   "="                     return EQUAL;
 156   ":"                     return COLON;
 157   "|"                     return PIPE;
 158   ";"                     return SEMICOLON;
 159
 160   {eols}      YY_LINES; YY_STEP;
 161   {blanks}    YY_STEP;
 162   {id}        {
 163     yylval->symbol = getsym (yytext, *yylloc);
 164     return ID;
 165   }
 166
 167   {int}       yylval->integer = strtol (yytext, 0, 10); return INT;
 168
 169   /* Characters.  We don't check there is only one.  */
 170   \'          YY_OBS_GROW; yy_push_state (SC_ESCAPED_CHARACTER);
 171
 172   /* Strings. */
 173   \"          YY_OBS_GROW; yy_push_state (SC_ESCAPED_STRING);
 174
 175   /* Comments. */
 176   "/*"        yy_push_state (SC_COMMENT);
 177   "//".*      YY_STEP;
 178
 179   /* Prologue. */
 180   "%{"        yy_push_state (SC_PROLOGUE);
 181
 182   /* Code in between braces.  */
 183   "{"         YY_OBS_GROW; ++braces_level; yy_push_state (SC_BRACED_CODE);
 184
 185   /* A type. */
 186   "<"[^>]+">" {
 187     obstack_grow (&string_obstack, yytext + 1, yyleng - 2);
 188     YY_OBS_FINISH;
 189     yylval->string = last_string;
 190     return TYPE;
 191   }
 192
 193
 194   "%%"   {
 195     if (++percent_percent_count == 2)
 196       yy_push_state (SC_EPILOGUE);
 197     return PERCENT_PERCENT;
 198   }
 199
 200   .           {
 201     LOCATION_PRINT (stderr, *yylloc);
 202     fprintf (stderr, ": invalid character: `%c'\n", *yytext);
 203     YY_STEP;
 204   }
 205 }
 206
 207
 208   /*------------------------------------------------------------.
 209   | Whatever the start condition (but those which correspond to |
 210   | entity `swallowed' by Bison: SC_ESCAPED_STRING and          |
 211   | SC_ESCAPED_CHARACTER), no M4 character must escape as is.   |
 212   `------------------------------------------------------------*/
 213
 214 <SC_COMMENT,SC_STRING,SC_CHARACTER,SC_BRACED_CODE,SC_PROLOGUE,SC_EPILOGUE>
 215 {
 216   \[          if (YY_START != SC_COMMENT) obstack_sgrow (&string_obstack, "@<:@");
 217   \]          if (YY_START != SC_COMMENT) obstack_sgrow (&string_obstack, "@:>@");
 218 }
 219
 220
 221
 222   /*-----------------------------------------------------------.
 223   | Scanning a C comment. The initial `/ *' is already eaten.  |
 224   `-----------------------------------------------------------*/
 225
 226 <SC_COMMENT>
 227 {
 228   "*/" { /* End of the comment. */
 229     if (yy_top_state () == INITIAL)
 230       {
 231         YY_STEP;
 232       }
 233     else
 234       {
 235         YY_OBS_GROW;
 236       }
 237     yy_pop_state ();
 238   }
 239
 240   [^\[\]*\n\r]+         if (yy_top_state () != INITIAL) YY_OBS_GROW;
 241   {eols}        if (yy_top_state () != INITIAL) YY_OBS_GROW; YY_LINES;
 242   .             /* Stray `*'. */if (yy_top_state () != INITIAL) YY_OBS_GROW;
 243
 244   <<EOF>> {
 245     LOCATION_PRINT (stderr, *yylloc);
 246     fprintf (stderr, ": unexpected end of file in a comment\n");
 247     yy_pop_state ();
 248   }
 249 }
 250
 251
 252   /*----------------------------------------------------------------.
 253   | Scanning a C string, including its escapes.  The initial `"' is |
 254   | already eaten.                                                  |
 255   `----------------------------------------------------------------*/
 256
 257 <SC_ESCAPED_STRING>
 258 {
 259   \" {
 260     assert (yy_top_state () == INITIAL);
 261     YY_OBS_GROW;
 262     YY_OBS_FINISH;
 263     yylval->string = last_string;
 264     yy_pop_state ();
 265     return STRING;
 266   }
 267
 268   [^\"\n\r\\]+      YY_OBS_GROW;
 269
 270   {eols}    obstack_1grow (&string_obstack, '\n'); YY_LINES;
 271
 272   <<EOF>> {
 273     LOCATION_PRINT (stderr, *yylloc);
 274     fprintf (stderr, ": unexpected end of file in a string\n");
 275     assert (yy_top_state () == INITIAL);
 276     YY_OBS_FINISH;
 277     yylval->string = last_string;
 278     yy_pop_state ();
 279     return STRING;
 280   }
 281 }
 282
 283   /*---------------------------------------------------------------.
 284   | Scanning a C character, decoding its escapes.  The initial "'" |
 285   | is already eaten.                                              |
 286   `---------------------------------------------------------------*/
 287
 288 <SC_ESCAPED_CHARACTER>
 289 {
 290   \' {
 291     YY_OBS_GROW;
 292     assert (yy_top_state () == INITIAL);
 293     {
 294       YY_OBS_FINISH;
 295       yylval->symbol = getsym (last_string, *yylloc);
 296       symbol_class_set (yylval->symbol, token_sym, *yylloc);
 297       symbol_user_token_number_set (yylval->symbol, last_string[1], *yylloc);
 298       YY_OBS_FREE;
 299       yy_pop_state ();
 300       return ID;
 301     }
 302   }
 303
 304   [^\'\n\r\\]      YY_OBS_GROW;
 305
 306   {eols}    obstack_1grow (&string_obstack, '\n'); YY_LINES;
 307
 308   <<EOF>> {
 309     LOCATION_PRINT (stderr, *yylloc);
 310     fprintf (stderr, ": unexpected end of file in a character\n");
 311     assert (yy_top_state () == INITIAL);
 312     YY_OBS_FINISH;
 313     yylval->string = last_string;
 314     yy_pop_state ();
 315     return CHARACTER;
 316   }
 317 }
 318
 319
 320   /*----------------------------.
 321   | Decode escaped characters.  |
 322   `----------------------------*/
 323
 324 <SC_ESCAPED_STRING,SC_ESCAPED_CHARACTER>
 325 {
 326   \\[0-7]{3}            {
 327     long c = strtol (yytext + 1, 0, 8);
 328     if (c > 255)
 329       {
 330         LOCATION_PRINT (stderr, *yylloc);
 331         fprintf (stderr, ": invalid escape: %s\n", quote (yytext));
 332         YY_STEP;
 333       }
 334     else
 335       obstack_1grow (&string_obstack, c);
 336   }
 337
 338   \\x[0-9a-fA-F]{2}     {
 339     obstack_1grow (&string_obstack, strtol (yytext + 2, 0, 16));
 340   }
 341
 342   \\a   obstack_1grow (&string_obstack, '\a');
 343   \\b   obstack_1grow (&string_obstack, '\b');
 344   \\f   obstack_1grow (&string_obstack, '\f');
 345   \\n   obstack_1grow (&string_obstack, '\n');
 346   \\r   obstack_1grow (&string_obstack, '\r');
 347   \\t   obstack_1grow (&string_obstack, '\t');
 348   \\v   obstack_1grow (&string_obstack, '\v');
 349   \\[\\""]   obstack_1grow (&string_obstack, yytext[1]);
 350   \\(.|\n)      {
 351     LOCATION_PRINT (stderr, *yylloc);
 352     fprintf (stderr, ": unrecognized escape: %s\n", quote (yytext));
 353     YY_OBS_GROW;
 354   }
 355   /* FLex wants this rule, in case of a `\<<EOF>>'. */
 356   \\                   YY_OBS_GROW;
 357 }
 358
 359
 360   /*----------------------------------------------------------.
 361   | Scanning a C character without decoding its escapes.  The |
 362   | initial "'" is already eaten.                             |
 363   `----------------------------------------------------------*/
 364
 365 <SC_CHARACTER>
 366 {
 367   \' {
 368     YY_OBS_GROW;
 369     assert (yy_top_state () != INITIAL);
 370     yy_pop_state ();
 371   }
 372
 373   [^\[\]\'\n\r\\]+     YY_OBS_GROW;
 374   \\(.|\n)             YY_OBS_GROW;
 375   /* FLex wants this rule, in case of a `\<<EOF>>'. */
 376   \\                   YY_OBS_GROW;
 377
 378   {eols}               YY_OBS_GROW; YY_LINES;
 379
 380   <<EOF>> {
 381     LOCATION_PRINT (stderr, *yylloc);
 382     fprintf (stderr, ": unexpected end of file in a character\n");
 383     assert (yy_top_state () != INITIAL);
 384     yy_pop_state ();
 385   }
 386 }
 387
 388
 389   /*----------------------------------------------------------------.
 390   | Scanning a C string, without decoding its escapes.  The initial |
 391   | `"' is already eaten.                                           |
 392   `----------------------------------------------------------------*/
 393
 394 <SC_STRING>
 395 {
 396   \" {
 397     assert (yy_top_state () != INITIAL);
 398     YY_OBS_GROW;
 399     yy_pop_state ();
 400   }
 401
 402   [^\[\]\"\n\r\\]+      YY_OBS_GROW;
 403   \\(.|\n)              YY_OBS_GROW;
 404   /* FLex wants this rule, in case of a `\<<EOF>>'. */
 405   \\                   YY_OBS_GROW;
 406
 407   {eols}                YY_OBS_GROW; YY_LINES;
 408
 409   <<EOF>> {
 410     LOCATION_PRINT (stderr, *yylloc);
 411     fprintf (stderr, ": unexpected end of file in a string\n");
 412     assert (yy_top_state () != INITIAL);
 413     yy_pop_state ();
 414   }
 415 }
 416
 417
 418   /*---------------------------------------------------.
 419   | Strings, comments etc. can be found in user code.  |
 420   `---------------------------------------------------*/
 421
 422 <SC_BRACED_CODE,SC_PROLOGUE,SC_EPILOGUE>
 423 {
 424   /* Characters.  We don't check there is only one.  */
 425   \'          YY_OBS_GROW; yy_push_state (SC_CHARACTER);
 426
 427   /* Strings. */
 428   \"          YY_OBS_GROW; yy_push_state (SC_STRING);
 429
 430   /* Comments. */
 431   "/*"        YY_OBS_GROW; yy_push_state (SC_COMMENT);
 432   "//".*      YY_OBS_GROW;
 433
 434   /* Not comments. */
 435   "/"         YY_OBS_GROW;
 436 }
 437
 438
 439   /*---------------------------------------------------------------.
 440   | Scanning some code in braces (%union and actions). The initial |
 441   | "{" is already eaten.                                          |
 442   `---------------------------------------------------------------*/
 443
 444 <SC_BRACED_CODE>
 445 {
 446   "}" {
 447     YY_OBS_GROW;
 448     if (--braces_level == 0)
 449       {
 450         yy_pop_state ();
 451         YY_OBS_FINISH;
 452         yylval->string = last_string;
 453         return BRACED_CODE;
 454       }
 455   }
 456
 457   "{"           YY_OBS_GROW; braces_level++;
 458
 459   "$"("<"[^>]+">")?(-?[0-9]+|"$") { handle_dollar (current_braced_code,
 460                                                    yytext, *yylloc); }
 461   "@"(-?[0-9]+|"$")               { handle_at (current_braced_code,
 462                                                yytext, *yylloc); }
 463
 464   [^$@\[\]/\'\"\{\}\n\r]+ YY_OBS_GROW;
 465   {eols}        YY_OBS_GROW; YY_LINES;
 466
 467   /* A lose $, or /, or etc. */
 468   .             YY_OBS_GROW;
 469
 470   <<EOF>> {
 471     LOCATION_PRINT (stderr, *yylloc);
 472     fprintf (stderr, ": unexpected end of file in a braced code\n");
 473     yy_pop_state ();
 474     YY_OBS_FINISH;
 475     yylval->string = last_string;
 476     return BRACED_CODE;
 477   }
 478
 479 }
 480
 481
 482   /*--------------------------------------------------------------.
 483   | Scanning some prologue: from "%{" (already scanned) to "%}".  |
 484   `--------------------------------------------------------------*/
 485
 486 <SC_PROLOGUE>
 487 {
 488   "%}" {
 489     yy_pop_state ();
 490     YY_OBS_FINISH;
 491     yylval->string = last_string;
 492     return PROLOGUE;
 493   }
 494
 495   [^%\[\]/\'\"\n\r]+ YY_OBS_GROW;
 496   "%"                YY_OBS_GROW;
 497   {eols}             YY_OBS_GROW; YY_LINES;
 498
 499   <<EOF>> {
 500     LOCATION_PRINT (stderr, *yylloc);
 501     fprintf (stderr, ": unexpected end of file in a prologue\n");
 502     yy_pop_state ();
 503     YY_OBS_FINISH;
 504     yylval->string = last_string;
 505     return PROLOGUE;
 506   }
 507 }
 508
 509
 510   /*---------------------------------------------------------------.
 511   | Scanning the epilogue (everything after the second "%%", which |
 512   | has already been eaten.                                        |
 513   `---------------------------------------------------------------*/
 514
 515 <SC_EPILOGUE>
 516 {
 517   ([^\[\]]|{eols})+  YY_OBS_GROW;
 518
 519   <<EOF>> {
 520     yy_pop_state ();
 521     YY_OBS_FINISH;
 522     yylval->string = last_string;
 523     return EPILOGUE;
 524   }
 525 }
 526
 527
 528 %%
 529
 530 /*------------------------------------------------------------------.
 531 | TEXT is pointing to a wannabee semantic value (i.e., a `$').      |
 532 |                                                                   |
 533 | Possible inputs: $[<TYPENAME>]($|integer)                         |
 534 |                                                                   |
 535 | Output to the STRING_OBSTACK a reference to this semantic value.  |
 536 `------------------------------------------------------------------*/
 537
 538 static inline void
 539 handle_action_dollar (char *text, location_t location)
 540 {
 541   const char *type_name = NULL;
 542   char *cp = text + 1;
 543
 544   /* Get the type name if explicit. */
 545   if (*cp == '<')
 546     {
 547       type_name = ++cp;
 548       while (*cp != '>')
 549         ++cp;
 550       *cp = '\0';
 551       ++cp;
 552     }
 553
 554   if (*cp == '$')
 555     {
 556       if (!type_name)
 557         type_name = symbol_list_n_type_name_get (current_rule, location, 0);
 558       if (!type_name && typed)
 559         complain_at (location, _("$$ of `%s' has no declared type"),
 560                      symbol_tag_get (current_rule->sym));
 561       if (!type_name)
 562         type_name = "";
 563       obstack_fgrow1 (&string_obstack,
 564                       "]b4_lhs_value([%s])[", type_name);
 565     }
 566   else if (isdigit (*cp) || *cp == '-')
 567     {
 568       /* RULE_LENGTH is the number of values in the current rule so
 569          far, which says where to find `$0' with respect to the top of
 570          the stack.  It is not the same as the rule->length in the
 571          case of mid rule actions.  */
 572       int rule_length = symbol_list_length (current_rule->next);
 573       int n = strtol (cp, &cp, 10);
 574
 575       if (n > rule_length)
 576         complain_at (location, _("invalid value: %s%d"), "$", n);
 577       else
 578         {
 579           if (!type_name && n > 0)
 580             type_name = symbol_list_n_type_name_get (current_rule, location,
 581                                                      n);
 582           if (!type_name && typed)
 583             complain_at (location, _("$%d of `%s' has no declared type"),
 584                       n, symbol_tag_get (current_rule->sym));
 585           if (!type_name)
 586             type_name = "";
 587           obstack_fgrow3 (&string_obstack,
 588                           "]b4_rhs_value([%d], [%d], [%s])[",
 589                           rule_length, n, type_name);
 590         }
 591     }
 592   else
 593     {
 594       complain_at (location, _("%s is invalid"), quote (text));
 595     }
 596 }
 597
 598
 599 /*---------------------------------------------------------------.
 600 | TEXT is expexted tp be $$ in some code associated to a symbol: |
 601 | destructor or printer.                                         |
 602 `---------------------------------------------------------------*/
 603
 604 static inline void
 605 handle_symbol_code_dollar (char *text, location_t location)
 606 {
 607   char *cp = text + 1;
 608   if (*cp == '$')
 609     obstack_sgrow (&string_obstack, "]b4_dollar_dollar[");
 610   else
 611     complain_at (location, _("%s is invalid"), quote (text));
 612 }
 613
 614
 615 /*-----------------------------------------------------------------.
 616 | Dispatch onto handle_action_dollar, or handle_destructor_dollar, |
 617 | depending upon CODE_KIND.                                        |
 618 `-----------------------------------------------------------------*/
 619
 620 static void
 621 handle_dollar (braced_code_t braced_code_kind,
 622                char *text, location_t location)
 623 {
 624   switch (braced_code_kind)
 625     {
 626     case action_braced_code:
 627       handle_action_dollar (text, location);
 628       break;
 629
 630     case destructor_braced_code:
 631     case printer_braced_code:
 632       handle_symbol_code_dollar (text, location);
 633       break;
 634     }
 635 }
 636
 637
 638 /*------------------------------------------------------.
 639 | TEXT is a location token (i.e., a `@...').  Output to |
 640 | STRING_OBSTACK a reference to this location.          |
 641 `------------------------------------------------------*/
 642
 643 static inline void
 644 handle_action_at (char *text, location_t location)
 645 {
 646   char *cp = text + 1;
 647   locations_flag = 1;
 648
 649   if (*cp == '$')
 650     {
 651       obstack_sgrow (&string_obstack, "]b4_lhs_location[");
 652     }
 653   else if (isdigit (*cp) || *cp == '-')
 654     {
 655       /* RULE_LENGTH is the number of values in the current rule so
 656          far, which says where to find `$0' with respect to the top of
 657          the stack.  It is not the same as the rule->length in the
 658          case of mid rule actions.  */
 659       int rule_length = symbol_list_length (current_rule->next);
 660       int n = strtol (cp, &cp, 10);
 661
 662       if (n > rule_length)
 663         complain_at (location, _("invalid value: %s%d"), "@", n);
 664       else
 665         obstack_fgrow2 (&string_obstack, "]b4_rhs_location([%d], [%d])[",
 666                         rule_length, n);
 667     }
 668   else
 669     {
 670       complain_at (location, _("%s is invalid"), quote (text));
 671     }
 672 }
 673
 674
 675 /*---------------------------------------------------------------.
 676 | TEXT is expexted tp be @$ in some code associated to a symbol: |
 677 | destructor or printer.                                         |
 678 `---------------------------------------------------------------*/
 679
 680 static inline void
 681 handle_symbol_code_at (char *text, location_t location)
 682 {
 683   char *cp = text + 1;
 684   if (*cp == '$')
 685     obstack_sgrow (&string_obstack, "]b4_at_dollar[");
 686   else
 687     complain_at (location, _("%s is invalid"), quote (text));
 688 }
 689
 690
 691 /*-------------------------------------------------------------------.
 692 | Dispatch onto handle_action_at, or handle_destructor_at, depending |
 693 | upon CODE_KIND.                                                    |
 694 `-------------------------------------------------------------------*/
 695
 696 static void
 697 handle_at (braced_code_t braced_code_kind,
 698            char *text, location_t location)
 699 {
 700   switch (braced_code_kind)
 701     {
 702     case action_braced_code:
 703       handle_action_at (text, location);
 704       break;
 705
 706     case destructor_braced_code:
 707     case printer_braced_code:
 708       handle_symbol_code_at (text, location);
 709       break;
 710     }
 711 }
 712
 713
 714 /*-------------------------.
 715 | Initialize the scanner.  |
 716 `-------------------------*/
 717
 718 void
 719 scanner_initialize (void)
 720 {
 721   obstack_init (&string_obstack);
 722 }
 723
 724
 725 /*-----------------------------------------------.
 726 | Free all the memory allocated to the scanner.  |
 727 `-----------------------------------------------*/
 728
 729 void
 730 scanner_free (void)
 731 {
 732   obstack_free (&string_obstack, 0);
 733 }