src/scan-code.l

   1 /* Bison Action Scanner                             -*- C -*-
   2
   3    Copyright (C) 2006-2012 Free Software Foundation, Inc.
   4
   5    This file is part of Bison, the GNU Compiler Compiler.
   6
   7    This program is free software: you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation, either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 %option debug nodefault noinput nounput noyywrap never-interactive
  21 %option prefix="code_" outfile="lex.yy.c"
  22
  23 %{
  24 /* Work around a bug in flex 2.5.31.  See Debian bug 333231
  25    <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=333231>.  */
  26 #undef code_wrap
  27 #define code_wrap() 1
  28
  29 #define FLEX_PREFIX(Id) code_ ## Id
  30 #include <src/flex-scanner.h>
  31
  32 #include <src/complain.h>
  33 #include <src/reader.h>
  34 #include <src/getargs.h>
  35 #include <src/muscle-tab.h>
  36 #include <src/scan-code.h>
  37 #include <src/symlist.h>
  38
  39 #include <c-ctype.h>
  40 #include <get-errno.h>
  41 #include <quote.h>
  42
  43 /* The current calling start condition: SC_RULE_ACTION or
  44    SC_SYMBOL_ACTION. */
  45 # define YY_DECL static char *code_lex (code_props *self, int sc_context)
  46 YY_DECL;
  47
  48 #define YY_USER_ACTION  location_compute (loc, &loc->end, yytext, yyleng);
  49
  50 static void handle_action_dollar (symbol_list *rule, char *cp,
  51                                   location dollar_loc);
  52 static void handle_action_at (symbol_list *rule, char *cp, location at_loc);
  53
  54 /* A string to be pushed to obstack after dollar/at has been handled. */
  55 static char *ref_tail_fields;
  56
  57 static location the_location;
  58 static location *loc = &the_location;
  59
  60 /* A string representing the most recent translation.  */
  61 static char *last_string;
  62
  63 /* True if an untyped $$ or $n was seen.  */
  64 static bool untyped_var_seen;
  65
  66 %}
  67  /* C and C++ comments in code. */
  68 %x SC_COMMENT SC_LINE_COMMENT
  69  /* Strings and characters in code. */
  70 %x SC_STRING SC_CHARACTER
  71  /* Whether in a rule or symbol action.  Specifies the translation
  72     of $ and @.  */
  73 %x SC_RULE_ACTION SC_SYMBOL_ACTION
  74
  75
  76 /* POSIX says that a tag must be both an id and a C union member, but
  77    historically almost any character is allowed in a tag.  We disallow
  78    NUL and newline, as this simplifies our implementation.  */
  79 tag      [^\0\n>]+
  80
  81 /* Zero or more instances of backslash-newline.  Following GCC, allow
  82    white space between the backslash and the newline.  */
  83 splice   (\\[ \f\t\v]*\n)*
  84
  85 /* C style identifier. Must start with letter. Will be used for
  86    named symbol references. Shall be kept synchronized with
  87    scan-gram.l "letter" and "id". */
  88 letter    [.abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_]
  89 id        {letter}({letter}|[-0-9])*
  90 ref      -?[0-9]+|{id}|"["{id}"]"|"$"
  91
  92 %%
  93
  94 %{
  95   /* Nesting level of the current code in braces.  */
  96   int braces_level = 0;
  97
  98   /* Whether a semicolon is probably needed.
  99      The heuristic is that a semicolon is not needed after '{', '}', ';',
 100      or a C preprocessor directive, and that whitespaces and comments
 101      do not affect this flag.
 102      Note that '{' does not need a semicolon because of '{}'.
 103      A semicolon may be needed before a cpp direcive, but don't bother.  */
 104   bool need_semicolon = false;
 105
 106   /* Whether in a C preprocessor directive.  Don't use a start condition
 107      for this because, at the end of strings and comments, we still need
 108      to know whether we're in a directive.  */
 109   bool in_cpp = false;
 110
 111   /* This scanner is special: it is invoked only once, henceforth
 112      is expected to return only once.  This initialization is
 113      therefore done once per action to translate. */
 114   aver (sc_context == SC_SYMBOL_ACTION
 115         || sc_context == SC_RULE_ACTION
 116         || sc_context == INITIAL);
 117   BEGIN sc_context;
 118 %}
 119
 120   /*------------------------------------------------------------.
 121   | Scanning a C comment.  The initial '/ *' is already eaten.  |
 122   `------------------------------------------------------------*/
 123
 124 <SC_COMMENT>
 125 {
 126   "*"{splice}"/"  STRING_GROW; BEGIN sc_context;
 127 }
 128
 129
 130   /*--------------------------------------------------------------.
 131   | Scanning a line comment.  The initial '//' is already eaten.  |
 132   `--------------------------------------------------------------*/
 133
 134 <SC_LINE_COMMENT>
 135 {
 136   "\n"           STRING_GROW; BEGIN sc_context;
 137   {splice}       STRING_GROW;
 138 }
 139
 140
 141   /*--------------------------------------------.
 142   | Scanning user-code characters and strings.  |
 143   `--------------------------------------------*/
 144
 145 <SC_CHARACTER,SC_STRING>
 146 {
 147   {splice}|\\{splice}.  STRING_GROW;
 148 }
 149
 150 <SC_CHARACTER>
 151 {
 152   "'"           STRING_GROW; BEGIN sc_context;
 153 }
 154
 155 <SC_STRING>
 156 {
 157   "\""          STRING_GROW; BEGIN sc_context;
 158 }
 159
 160
 161 <SC_RULE_ACTION,SC_SYMBOL_ACTION>{
 162   "'" {
 163     STRING_GROW;
 164     BEGIN SC_CHARACTER;
 165     need_semicolon = true;
 166   }
 167   "\"" {
 168     STRING_GROW;
 169     BEGIN SC_STRING;
 170     need_semicolon = true;
 171   }
 172   "/"{splice}"*" {
 173     STRING_GROW;
 174     BEGIN SC_COMMENT;
 175   }
 176   "/"{splice}"/" {
 177     STRING_GROW;
 178     BEGIN SC_LINE_COMMENT;
 179   }
 180 }
 181
 182 <SC_RULE_ACTION>
 183 {
 184   "$"("<"{tag}">")?{ref}  {
 185     ref_tail_fields = 0;
 186     handle_action_dollar (self->rule, yytext, *loc);
 187     if (ref_tail_fields) {
 188       obstack_sgrow (&obstack_for_string, ref_tail_fields);
 189     }
 190     need_semicolon = true;
 191   }
 192   "@"{ref} {
 193     ref_tail_fields = 0;
 194     handle_action_at (self->rule, yytext, *loc);
 195     if (ref_tail_fields) {
 196       obstack_sgrow (&obstack_for_string, ref_tail_fields);
 197     }
 198     need_semicolon = true;
 199   }
 200   "$"  {
 201     complain_at (*loc, Wother, _("stray '$'"));
 202     obstack_sgrow (&obstack_for_string, "$][");
 203     need_semicolon = true;
 204   }
 205   "@"  {
 206     complain_at (*loc, Wother, _("stray '@'"));
 207     obstack_sgrow (&obstack_for_string, "@@");
 208     need_semicolon = true;
 209   }
 210   "["  {
 211     obstack_sgrow (&obstack_for_string, "@{");
 212     need_semicolon = true;
 213   }
 214   "]"  {
 215     obstack_sgrow (&obstack_for_string, "@}");
 216     need_semicolon = true;
 217   }
 218
 219   ";"  STRING_GROW;                 need_semicolon = false;
 220   "{"  STRING_GROW; ++braces_level; need_semicolon = false;
 221   "}"  {
 222     bool outer_brace = --braces_level == 0;
 223
 224     /* As an undocumented Bison extension, append ';' before the last
 225        brace in braced code, so that the user code can omit trailing
 226        ';'.  But do not append ';' if emulating Yacc, since Yacc does
 227        not append one.  */
 228     if (outer_brace && !yacc_flag && language_prio == default_prio
 229         && skeleton_prio == default_prio && need_semicolon && ! in_cpp)
 230       {
 231         complain_at (*loc, Wother,
 232                      _("a ';' might be needed at the end of action code"));
 233         complain_at (*loc, Wother,
 234                      _("future versions of Bison will not add the ';'"));
 235         obstack_1grow (&obstack_for_string, ';');
 236       }
 237
 238     STRING_GROW;
 239     need_semicolon = false;
 240   }
 241
 242   /* Preprocessing directives should only be recognized at the beginning
 243      of lines, allowing whitespace including comments, but in C/C++,
 244      '#' can only be the start of preprocessor directives or within
 245      '#define' directives anyway, so don't bother with begin of line.  */
 246   "#"       STRING_GROW; in_cpp = true;
 247
 248   {splice}  STRING_GROW;
 249   [\n\r]    STRING_GROW; if (in_cpp) in_cpp = need_semicolon = false;
 250   [ \t\f]   STRING_GROW;
 251
 252   /* YYFAIL is undocumented and was formally deprecated in Bison
 253      2.4.2.  */
 254   YYFAIL {
 255     STRING_GROW; need_semicolon = true;
 256     complain_at (*loc, Wother,
 257                  _("use of YYFAIL, which is deprecated and will be removed"));
 258   }
 259
 260   /* The sole purpose of this is to make sure identifiers that merely
 261      contain YYFAIL don't produce the above warning.  */
 262   [A-Za-z_][0-9A-Za-z_]* STRING_GROW; need_semicolon = true;
 263
 264   . STRING_GROW; need_semicolon = true;
 265 }
 266
 267 <SC_SYMBOL_ACTION>
 268 {
 269   "$$" {
 270     obstack_sgrow (&obstack_for_string, "]b4_dollar_dollar[");
 271     self->is_value_used = true;
 272   }
 273   "@$" {
 274     obstack_sgrow (&obstack_for_string, "]b4_at_dollar[");
 275     muscle_percent_define_ensure("locations", the_location, true);
 276   }
 277 }
 278
 279
 280   /*-----------------------------------------.
 281   | Escape M4 quoting characters in C code.  |
 282   `-----------------------------------------*/
 283
 284 <*>
 285 {
 286   \$    obstack_sgrow (&obstack_for_string, "$][");
 287   \@    obstack_sgrow (&obstack_for_string, "@@");
 288   \[    obstack_sgrow (&obstack_for_string, "@{");
 289   \]    obstack_sgrow (&obstack_for_string, "@}");
 290 }
 291
 292   /*-----------------------------------------------------.
 293   | By default, grow the string obstack with the input.  |
 294   `-----------------------------------------------------*/
 295
 296 <*>.|\n STRING_GROW;
 297
 298  /* End of processing. */
 299 <*><<EOF>>       {
 300                    STRING_FINISH;
 301                    return last_string;
 302                  }
 303
 304 %%
 305
 306 static inline bool
 307 is_dot_or_dash (char ch)
 308 {
 309   return ch == '.' || ch == '-';
 310 }
 311
 312 static inline bool
 313 contains_dot_or_dash (const char* p)
 314 {
 315   for (; *p; ++p)
 316     if (is_dot_or_dash (*p))
 317       return true;
 318   return false;
 319 }
 320
 321 /* Defines a variant of a symbolic name resolution. */
 322 typedef struct
 323 {
 324   /* Index in symbol list. */
 325   unsigned symbol_index;
 326
 327   /* Matched symbol id and loc. */
 328   uniqstr id;
 329   location loc;
 330
 331   /* Hiding named reference. */
 332   named_ref* hidden_by;
 333
 334   /* Error flags. May contain zero (no errors) or
 335      a combination of VARIANT_* values. */
 336   unsigned err;
 337 } variant;
 338
 339 /* Set when the variant refers to a symbol hidden
 340    by an explicit symbol reference. */
 341 #define VARIANT_HIDDEN (1 << 0)
 342
 343 /* Set when the variant refers to a symbol containing
 344    dots or dashes. Will require explicit bracketing. */
 345 #define VARIANT_BAD_BRACKETING (1 << 1)
 346
 347 /* Set when the variant refers to a symbol which is
 348    not visible from current midrule. */
 349 #define VARIANT_NOT_VISIBLE_FROM_MIDRULE (1 << 2)
 350
 351 static variant *variant_table = 0;
 352 static unsigned variant_table_size = 0;
 353 static unsigned variant_count = 0;
 354
 355 static variant *
 356 variant_table_grow (void)
 357 {
 358   ++variant_count;
 359   if (variant_count > variant_table_size)
 360     {
 361       while (variant_count > variant_table_size)
 362         variant_table_size = 2 * variant_table_size + 3;
 363       variant_table = xnrealloc (variant_table, variant_table_size,
 364                                  sizeof *variant_table);
 365     }
 366   return &variant_table[variant_count - 1];
 367 }
 368
 369 static void
 370 variant_table_free (void)
 371 {
 372   free (variant_table);
 373   variant_table = 0;
 374   variant_table_size = variant_count = 0;
 375 }
 376
 377 static char *
 378 find_prefix_end (const char *prefix, char *begin, char *end)
 379 {
 380   char *ptr = begin;
 381
 382   for (; *prefix && ptr != end; ++prefix, ++ptr)
 383     if (*prefix != *ptr)
 384       return 0;
 385
 386   if (*prefix)
 387     return 0;
 388
 389   return ptr;
 390 }
 391
 392 static variant *
 393 variant_add (uniqstr id, location id_loc, unsigned symbol_index,
 394              char *cp, char *cp_end, bool explicit_bracketing)
 395 {
 396   char *prefix_end;
 397
 398   prefix_end = find_prefix_end (id, cp, cp_end);
 399   if (prefix_end &&
 400       (prefix_end == cp_end ||
 401        (!explicit_bracketing && is_dot_or_dash (*prefix_end))))
 402     {
 403       variant *r = variant_table_grow ();
 404       r->symbol_index = symbol_index;
 405       r->id = id;
 406       r->loc = id_loc;
 407       r->hidden_by = NULL;
 408       r->err = 0;
 409       return r;
 410     }
 411   else
 412     return NULL;
 413 }
 414
 415 static const char *
 416 get_at_spec(unsigned symbol_index)
 417 {
 418   static char at_buf[20];
 419   if (symbol_index == 0)
 420     strcpy (at_buf, "$$");
 421   else
 422     snprintf (at_buf, sizeof at_buf, "$%u", symbol_index);
 423   return at_buf;
 424 }
 425
 426 static void
 427 show_sub_messages (const char* cp, bool explicit_bracketing,
 428                    int midrule_rhs_index, char dollar_or_at,
 429                    bool is_warning, unsigned indent)
 430 {
 431   unsigned i;
 432
 433   for (i = 0; i < variant_count; ++i)
 434     {
 435       const variant *var = &variant_table[i];
 436       const char *at_spec = get_at_spec (var->symbol_index);
 437
 438       if (var->err == 0)
 439         {
 440           if (is_warning)
 441             complain_at_indent (var->loc, Wother, &indent,
 442                                 _("refers to: %c%s at %s"), dollar_or_at,
 443                                 var->id, at_spec);
 444           else
 445             complain_at_indent (var->loc, complaint, &indent,
 446                                 _("refers to: %c%s at %s"), dollar_or_at,
 447                                 var->id, at_spec);
 448         }
 449       else
 450         {
 451           static struct obstack msg_buf;
 452           const char *tail = explicit_bracketing ? "" :
 453             cp + strlen (var->id);
 454           const char *id = var->hidden_by ? var->hidden_by->id :
 455             var->id;
 456           location id_loc = var->hidden_by ? var->hidden_by->loc :
 457             var->loc;
 458
 459           /* Create the explanation message. */
 460           obstack_init (&msg_buf);
 461
 462           obstack_fgrow1 (&msg_buf, _("possibly meant: %c"), dollar_or_at);
 463           if (contains_dot_or_dash (id))
 464             obstack_fgrow1 (&msg_buf, "[%s]", id);
 465           else
 466             obstack_sgrow (&msg_buf, id);
 467           obstack_sgrow (&msg_buf, tail);
 468
 469           if (var->err & VARIANT_HIDDEN)
 470             {
 471               obstack_fgrow1 (&msg_buf, _(", hiding %c"), dollar_or_at);
 472               if (contains_dot_or_dash (var->id))
 473                 obstack_fgrow1 (&msg_buf, "[%s]", var->id);
 474               else
 475                 obstack_sgrow (&msg_buf, var->id);
 476               obstack_sgrow (&msg_buf, tail);
 477             }
 478
 479           obstack_fgrow1 (&msg_buf, _(" at %s"), at_spec);
 480
 481           if (var->err & VARIANT_NOT_VISIBLE_FROM_MIDRULE)
 482             {
 483               const char *format =
 484                 _(", cannot be accessed from mid-rule action at $%d");
 485               obstack_fgrow1 (&msg_buf, format, midrule_rhs_index);
 486             }
 487
 488           obstack_1grow (&msg_buf, '\0');
 489           if (is_warning)
 490             complain_at_indent (id_loc, Wother, &indent, "%s",
 491                                 (char *) obstack_finish (&msg_buf));
 492           else
 493             complain_at_indent (id_loc, complaint, &indent, "%s",
 494                                 (char *) obstack_finish (&msg_buf));
 495           obstack_free (&msg_buf, 0);
 496         }
 497     }
 498 }
 499
 500 /* Returned from "parse_ref" when the reference
 501    is inappropriate. */
 502 #define INVALID_REF (INT_MIN)
 503
 504 /* Returned from "parse_ref" when the reference
 505    points to LHS ($$) of the current rule or midrule. */
 506 #define LHS_REF (INT_MIN + 1)
 507
 508 /* Sub-messages indent. */
 509 #define SUB_INDENT (4)
 510
 511 /* Parse named or positional reference. In case of positional
 512    references, can return negative values for $-n "deep" stack
 513    accesses. */
 514 static long int
 515 parse_ref (char *cp, symbol_list *rule, int rule_length,
 516            int midrule_rhs_index, char *text, location text_loc,
 517            char dollar_or_at)
 518 {
 519   symbol_list *l;
 520   char *cp_end;
 521   bool explicit_bracketing;
 522   unsigned i;
 523   unsigned valid_variants = 0;
 524   unsigned valid_variant_index = 0;
 525
 526   if ('$' == *cp)
 527     return LHS_REF;
 528
 529   if (c_isdigit (*cp) || (*cp == '-' && c_isdigit (* (cp + 1))))
 530     {
 531       long int num = strtol (cp, &cp, 10);
 532       if (1 - INT_MAX + rule_length <= num && num <= rule_length)
 533         return num;
 534       else
 535         {
 536           complain_at (text_loc, complaint, _("integer out of range: %s"),
 537                        quote (text));
 538           return INVALID_REF;
 539         }
 540     }
 541
 542   if ('[' == *cp)
 543     {
 544       /* Ignore the brackets. */
 545       char *p;
 546       for (p = ++cp; *p != ']'; ++p)
 547         continue;
 548       cp_end = p;
 549
 550       explicit_bracketing = true;
 551     }
 552   else
 553     {
 554       /* Take all characters of the name. */
 555       char* p;
 556       for (p = cp; *p; ++p)
 557         if (is_dot_or_dash (*p))
 558           {
 559             ref_tail_fields = p;
 560             break;
 561           }
 562       for (p = cp; *p; ++p)
 563         continue;
 564       cp_end = p;
 565
 566       explicit_bracketing = false;
 567     }
 568
 569   /* Add all relevant variants. */
 570   {
 571     unsigned symbol_index;
 572     variant_count = 0;
 573     for (symbol_index = 0, l = rule; !symbol_list_null (l);
 574          ++symbol_index, l = l->next)
 575       {
 576         variant *var;
 577         if (l->content_type != SYMLIST_SYMBOL)
 578           continue;
 579
 580         var = variant_add (l->content.sym->tag, l->sym_loc,
 581                            symbol_index, cp, cp_end, explicit_bracketing);
 582         if (var && l->named_ref)
 583           var->hidden_by = l->named_ref;
 584
 585         if (l->named_ref)
 586           variant_add (l->named_ref->id, l->named_ref->loc,
 587                        symbol_index, cp, cp_end, explicit_bracketing);
 588       }
 589   }
 590
 591   /* Check errors. */
 592   for (i = 0; i < variant_count; ++i)
 593     {
 594       variant *var = &variant_table[i];
 595       unsigned symbol_index = var->symbol_index;
 596
 597       /* Check visibility from mid-rule actions. */
 598       if (midrule_rhs_index != 0
 599           && (symbol_index == 0 || midrule_rhs_index < symbol_index))
 600         var->err |= VARIANT_NOT_VISIBLE_FROM_MIDRULE;
 601
 602       /* Check correct bracketing. */
 603       if (!explicit_bracketing && contains_dot_or_dash (var->id))
 604         var->err |= VARIANT_BAD_BRACKETING;
 605
 606       /* Check using of hidden symbols. */
 607       if (var->hidden_by)
 608         var->err |= VARIANT_HIDDEN;
 609
 610       if (!var->err)
 611         {
 612           valid_variant_index = i;
 613           ++valid_variants;
 614         }
 615     }
 616
 617   switch (valid_variants)
 618     {
 619     case 0:
 620       {
 621         unsigned len = (explicit_bracketing || !ref_tail_fields) ?
 622           cp_end - cp : ref_tail_fields - cp;
 623         unsigned indent = 0;
 624
 625         complain_at_indent (text_loc, complaint, &indent,
 626                             _("invalid reference: %s"), quote (text));
 627         indent += SUB_INDENT;
 628         if (len == 0)
 629           {
 630             location sym_loc = text_loc;
 631             sym_loc.start.column += 1;
 632             sym_loc.end = sym_loc.start;
 633             const char *format =
 634               _("syntax error after '%c', expecting integer, letter,"
 635                 " '_', '[', or '$'");
 636             complain_at_indent (sym_loc, complaint, &indent, format,
 637                                 dollar_or_at);
 638           }
 639         else if (midrule_rhs_index)
 640           {
 641             const char *format =
 642               _("symbol not found in production before $%d: %.*s");
 643             complain_at_indent (rule->location, complaint, &indent, format,
 644                                 midrule_rhs_index, len, cp);
 645           }
 646         else
 647           {
 648             const char *format =
 649               _("symbol not found in production: %.*s");
 650             complain_at_indent (rule->location, complaint, &indent, format,
 651                                 len, cp);
 652           }
 653
 654         if (variant_count > 0)
 655           show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
 656                              dollar_or_at, false, indent);
 657         return INVALID_REF;
 658       }
 659     case 1:
 660       {
 661         unsigned indent = 0;
 662         if (variant_count > 1)
 663           {
 664             complain_at_indent (text_loc, Wother, &indent,
 665                                 _("misleading reference: %s"), quote (text));
 666             show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
 667                                dollar_or_at, true, indent + SUB_INDENT);
 668           }
 669         {
 670           unsigned symbol_index =
 671             variant_table[valid_variant_index].symbol_index;
 672           return (symbol_index == midrule_rhs_index) ? LHS_REF : symbol_index;
 673         }
 674       }
 675     case 2:
 676     default:
 677       {
 678         unsigned indent = 0;
 679         complain_at_indent (text_loc, complaint, &indent,
 680                             _("ambiguous reference: %s"), quote (text));
 681         show_sub_messages (cp, explicit_bracketing, midrule_rhs_index,
 682                            dollar_or_at, false, indent + SUB_INDENT);
 683         return INVALID_REF;
 684       }
 685     }
 686
 687   /* Not reachable. */
 688   return INVALID_REF;
 689 }
 690
 691 /* Keeps track of the maximum number of semantic values to the left of
 692    a handle (those referenced by $0, $-1, etc.) are required by the
 693    semantic actions of this grammar. */
 694 int max_left_semantic_context = 0;
 695
 696
 697 /*------------------------------------------------------------------.
 698 | TEXT is pointing to a wannabee semantic value (i.e., a '$').      |
 699 |                                                                   |
 700 | Possible inputs: $[<TYPENAME>]($|integer)                         |
 701 |                                                                   |
 702 | Output to OBSTACK_FOR_STRING a reference to this semantic value.  |
 703 `------------------------------------------------------------------*/
 704
 705 static void
 706 handle_action_dollar (symbol_list *rule, char *text, location dollar_loc)
 707 {
 708   char const *type_name = NULL;
 709   char *cp = text + 1;
 710   char *gt_ptr = 0;
 711   symbol_list *effective_rule;
 712   int effective_rule_length;
 713   int n;
 714
 715   if (rule->midrule_parent_rule)
 716     {
 717       effective_rule = rule->midrule_parent_rule;
 718       effective_rule_length = rule->midrule_parent_rhs_index - 1;
 719     }
 720   else
 721     {
 722       effective_rule = rule;
 723       effective_rule_length = symbol_list_length (rule->next);
 724     }
 725
 726   /* Get the type name if explicit. */
 727   if (*cp == '<')
 728     {
 729       type_name = ++cp;
 730       while (*cp != '>')
 731         ++cp;
 732
 733       /* The '>' symbol will be later replaced by '\0'. Original
 734          'text' is needed for error messages. */
 735       gt_ptr = cp;
 736       ++cp;
 737       if (untyped_var_seen)
 738         complain_at (dollar_loc, complaint,
 739                   _("explicit type given in untyped grammar"));
 740       tag_seen = true;
 741     }
 742
 743   n = parse_ref (cp, effective_rule, effective_rule_length,
 744                  rule->midrule_parent_rhs_index, text, dollar_loc, '$');
 745
 746   if (gt_ptr)
 747     *gt_ptr = '\0';
 748
 749   switch (n)
 750     {
 751     case INVALID_REF:
 752       break;
 753
 754     case LHS_REF:
 755       if (!type_name)
 756         type_name = symbol_list_n_type_name_get (rule, dollar_loc, 0);
 757
 758       if (!type_name)
 759         {
 760           if (union_seen | tag_seen)
 761             {
 762               if (rule->midrule_parent_rule)
 763                 complain_at (dollar_loc, complaint,
 764                              _("$$ for the midrule at $%d of %s"
 765                                " has no declared type"),
 766                              rule->midrule_parent_rhs_index,
 767                              quote (effective_rule->content.sym->tag));
 768               else
 769                 complain_at (dollar_loc, complaint,
 770                              _("$$ of %s has no declared type"),
 771                              quote (rule->content.sym->tag));
 772             }
 773           else
 774             untyped_var_seen = true;
 775           type_name = "";
 776         }
 777
 778       obstack_fgrow1 (&obstack_for_string,
 779                       "]b4_lhs_value([%s])[", type_name);
 780       rule->action_props.is_value_used = true;
 781       break;
 782
 783     default:
 784       if (max_left_semantic_context < 1 - n)
 785         max_left_semantic_context = 1 - n;
 786       if (!type_name && 0 < n)
 787         type_name =
 788           symbol_list_n_type_name_get (effective_rule, dollar_loc, n);
 789       if (!type_name)
 790         {
 791           if (union_seen | tag_seen)
 792             complain_at (dollar_loc, complaint,
 793                          _("$%s of %s has no declared type"), cp,
 794                          quote (effective_rule->content.sym->tag));
 795           else
 796             untyped_var_seen = true;
 797           type_name = "";
 798         }
 799
 800       obstack_fgrow3 (&obstack_for_string,
 801                       "]b4_rhs_value(%d, %d, [%s])[",
 802                       effective_rule_length, n, type_name);
 803       if (n > 0)
 804         symbol_list_n_get (effective_rule, n)->action_props.is_value_used =
 805           true;
 806       break;
 807     }
 808 }
 809
 810
 811 /*------------------------------------------------------.
 812 | TEXT is a location token (i.e., a '@...').  Output to |
 813 | OBSTACK_FOR_STRING a reference to this location.      |
 814 `------------------------------------------------------*/
 815
 816 static void
 817 handle_action_at (symbol_list *rule, char *text, location at_loc)
 818 {
 819   char *cp = text + 1;
 820   symbol_list *effective_rule;
 821   int effective_rule_length;
 822   int n;
 823
 824   if (rule->midrule_parent_rule)
 825     {
 826       effective_rule = rule->midrule_parent_rule;
 827       effective_rule_length = rule->midrule_parent_rhs_index - 1;
 828     }
 829   else
 830     {
 831       effective_rule = rule;
 832       effective_rule_length = symbol_list_length (rule->next);
 833     }
 834
 835   muscle_percent_define_ensure("locations", at_loc, true);
 836
 837   n = parse_ref (cp, effective_rule, effective_rule_length,
 838                        rule->midrule_parent_rhs_index, text, at_loc, '@');
 839   switch (n)
 840     {
 841     case INVALID_REF:
 842       break;
 843
 844     case LHS_REF:
 845       obstack_sgrow (&obstack_for_string, "]b4_lhs_location[");
 846       break;
 847
 848     default:
 849       obstack_fgrow2 (&obstack_for_string, "]b4_rhs_location(%d, %d)[",
 850                       effective_rule_length, n);
 851       break;
 852     }
 853 }
 854
 855
 856 /*-------------------------.
 857 | Initialize the scanner.  |
 858 `-------------------------*/
 859
 860 /* Translate the dollars and ats in \a self, in the context \a sc_context
 861    (SC_RULE_ACTION, SC_SYMBOL_ACTION, INITIAL).  */
 862
 863 static char const *
 864 translate_action (code_props *self, int sc_context)
 865 {
 866   char *res;
 867   static bool initialized = false;
 868   if (!initialized)
 869     {
 870       obstack_init (&obstack_for_string);
 871       yy_flex_debug = 0;
 872       initialized = true;
 873     }
 874
 875   loc->start = loc->end = self->location.start;
 876   yy_switch_to_buffer (yy_scan_string (self->code));
 877   res = code_lex (self, sc_context);
 878   yy_delete_buffer (YY_CURRENT_BUFFER);
 879
 880   return res;
 881 }
 882
 883 /*------------------------------------------------------------------------.
 884 | Implementation of the public interface as documented in "scan-code.h".  |
 885 `------------------------------------------------------------------------*/
 886
 887 void
 888 code_props_none_init (code_props *self)
 889 {
 890   *self = code_props_none;
 891 }
 892
 893 code_props code_props_none = CODE_PROPS_NONE_INIT;
 894
 895 void
 896 code_props_plain_init (code_props *self, char const *code,
 897                        location code_loc)
 898 {
 899   code_props_none_init (self);
 900   self->kind = CODE_PROPS_PLAIN;
 901   self->code = code;
 902   self->location = code_loc;
 903 }
 904
 905 void
 906 code_props_symbol_action_init (code_props *self, char const *code,
 907                                location code_loc)
 908 {
 909   code_props_none_init (self);
 910   self->kind = CODE_PROPS_SYMBOL_ACTION;
 911   self->code = code;
 912   self->location = code_loc;
 913 }
 914
 915 void
 916 code_props_rule_action_init (code_props *self, char const *code,
 917                              location code_loc, symbol_list *rule,
 918                              named_ref *name, bool is_predicate)
 919 {
 920   code_props_none_init (self);
 921   self->kind = CODE_PROPS_RULE_ACTION;
 922   self->code = code;
 923   self->location = code_loc;
 924   self->rule = rule;
 925   self->named_ref = name;
 926   self->is_predicate = is_predicate;
 927 }
 928
 929 void
 930 code_props_translate_code (code_props *self)
 931 {
 932   switch (self->kind)
 933     {
 934       case CODE_PROPS_NONE:
 935         break;
 936       case CODE_PROPS_PLAIN:
 937         self->code = translate_action (self, INITIAL);
 938         break;
 939       case CODE_PROPS_SYMBOL_ACTION:
 940         self->code = translate_action (self, SC_SYMBOL_ACTION);
 941         break;
 942       case CODE_PROPS_RULE_ACTION:
 943         self->code = translate_action (self, SC_RULE_ACTION);
 944         break;
 945     }
 946 }
 947
 948 void
 949 code_scanner_last_string_free (void)
 950 {
 951   STRING_FREE;
 952 }
 953
 954 void
 955 code_scanner_free (void)
 956 {
 957   obstack_free (&obstack_for_string, 0);
 958   variant_table_free ();
 959
 960   /* Reclaim Flex's buffers.  */
 961   yylex_destroy ();
 962 }