src/scan-gram.l

   1 /* Bison Grammar Scanner                             -*- C -*-
   2
   3    Copyright (C) 2002-2013 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 noyywrap never-interactive
  21 %option prefix="gram_" 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 gram_wrap
  27 #define gram_wrap() 1
  28
  29 #define FLEX_PREFIX(Id) gram_ ## Id
  30 #include <src/flex-scanner.h>
  31
  32 #include <src/complain.h>
  33 #include <src/files.h>
  34 #include <src/getargs.h>
  35 #include <src/gram.h>
  36 #include <quotearg.h>
  37 #include <src/reader.h>
  38 #include <src/uniqstr.h>
  39
  40 #include <c-ctype.h>
  41 #include <mbswidth.h>
  42 #include <quote.h>
  43
  44 #include <src/scan-gram.h>
  45
  46 #define YY_DECL GRAM_LEX_DECL
  47
  48 #define YY_USER_INIT                                    \
  49    code_start = scanner_cursor = loc->start;            \
  50
  51 /* Location of scanner cursor.  */
  52 static boundary scanner_cursor;
  53
  54 #define YY_USER_ACTION  location_compute (loc, &scanner_cursor, yytext, yyleng);
  55
  56 static size_t no_cr_read (FILE *, char *, size_t);
  57 #define YY_INPUT(buf, result, size) ((result) = no_cr_read (yyin, buf, size))
  58
  59 #define RETURN_PERCENT_PARAM(Value)                     \
  60   RETURN_VALUE(PERCENT_PARAM, param, param_ ## Value)
  61
  62 #define RETURN_PERCENT_FLAG(Value)                              \
  63   RETURN_VALUE(PERCENT_FLAG, uniqstr, uniqstr_new (Value))
  64
  65 #define RETURN_VALUE(Token, Field, Value)       \
  66   do {                                          \
  67     val->Field = Value;                         \
  68     return Token;                               \
  69   } while (0)
  70
  71 #define ROLLBACK_CURRENT_TOKEN                                  \
  72   do {                                                          \
  73     scanner_cursor.column -= mbsnwidth (yytext, yyleng, 0);     \
  74     yyless (0);                                                 \
  75   } while (0)
  76
  77 #define DEPRECATED(Msg)                                         \
  78   do {                                                          \
  79     size_t i;                                                   \
  80     deprecated_directive (loc, yytext, Msg);                    \
  81     scanner_cursor.column -= mbsnwidth (Msg, strlen (Msg), 0);  \
  82     for (i = strlen (Msg); i != 0; --i)                         \
  83       unput (Msg[i - 1]);                                       \
  84   } while (0)
  85
  86 /* A string representing the most recently saved token.  */
  87 static char *last_string;
  88
  89 /* Bracketed identifier. */
  90 static uniqstr bracketed_id_str = 0;
  91 static location bracketed_id_loc;
  92 static boundary bracketed_id_start;
  93 static int bracketed_id_context_state = 0;
  94
  95 void
  96 gram_scanner_last_string_free (void)
  97 {
  98   STRING_FREE;
  99 }
 100
 101 static void handle_syncline (char *, location);
 102 static unsigned long int scan_integer (char const *p, int base, location loc);
 103 static int convert_ucn_to_byte (char const *hex_text);
 104 static void unexpected_eof (boundary, char const *);
 105 static void unexpected_newline (boundary, char const *);
 106
 107 %}
 108  /* A C-like comment in directives/rules. */
 109 %x SC_YACC_COMMENT
 110  /* Strings and characters in directives/rules. */
 111 %x SC_ESCAPED_STRING SC_ESCAPED_CHARACTER
 112  /* A identifier was just read in directives/rules.  Special state
 113     to capture the sequence 'identifier :'. */
 114 %x SC_AFTER_IDENTIFIER
 115
 116  /* POSIX says that a tag must be both an id and a C union member, but
 117     historically almost any character is allowed in a tag.  We
 118     disallow NUL, as this simplifies our implementation.  We match
 119     angle brackets in nested pairs: several languages use them for
 120     generics/template types.  */
 121 %x SC_TAG
 122
 123  /* Four types of user code:
 124     - prologue (code between '%{' '%}' in the first section, before %%);
 125     - actions, printers, union, etc, (between braced in the middle section);
 126     - epilogue (everything after the second %%).
 127     - predicate (code between '%?{' and '{' in middle section); */
 128 %x SC_PROLOGUE SC_BRACED_CODE SC_EPILOGUE SC_PREDICATE
 129  /* C and C++ comments in code. */
 130 %x SC_COMMENT SC_LINE_COMMENT
 131  /* Strings and characters in code. */
 132 %x SC_STRING SC_CHARACTER
 133  /* Bracketed identifiers support. */
 134 %x SC_BRACKETED_ID SC_RETURN_BRACKETED_ID
 135
 136 letter    [.abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_]
 137 notletter [^.abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_]{-}[%\{]
 138 id        {letter}({letter}|[-0-9])*
 139 int       [0-9]+
 140
 141 /* Zero or more instances of backslash-newline.  Following GCC, allow
 142    white space between the backslash and the newline.  */
 143 splice   (\\[ \f\t\v]*\n)*
 144
 145 /* An equal sign, with optional leading whitespaces. This is used in some
 146    deprecated constructs. */
 147 eqopt    ([[:space:]]*=)?
 148
 149 %%
 150 %{
 151   /* Nesting level.  Either for nested braces, or nested angle brackets
 152      (but not mixed).  */
 153   int nesting PACIFY_CC (= 0);
 154
 155   /* Parent context state, when applicable.  */
 156   int context_state PACIFY_CC (= 0);
 157
 158   /* Location of most recent identifier, when applicable.  */
 159   location id_loc PACIFY_CC (= empty_location);
 160
 161   /* Where containing code started, when applicable.  Its initial
 162      value is relevant only when yylex is invoked in the SC_EPILOGUE
 163      start condition.  */
 164   boundary code_start = scanner_cursor;
 165
 166   /* Where containing comment or string or character literal started,
 167      when applicable.  */
 168   boundary token_start PACIFY_CC (= scanner_cursor);
 169 %}
 170
 171
 172   /*-----------------------.
 173   | Scanning white space.  |
 174   `-----------------------*/
 175
 176 <INITIAL,SC_AFTER_IDENTIFIER,SC_BRACKETED_ID,SC_RETURN_BRACKETED_ID>
 177 {
 178   /* Comments and white space.  */
 179   "," {
 180      complain (loc, Wother, _("stray ',' treated as white space"));
 181   }
 182   [ \f\n\t\v]  |
 183   "//".*       continue;
 184   "/*" {
 185     token_start = loc->start;
 186     context_state = YY_START;
 187     BEGIN SC_YACC_COMMENT;
 188   }
 189
 190   /* #line directives are not documented, and may be withdrawn or
 191      modified in future versions of Bison.  */
 192   ^"#line "{int}(" \"".*"\"")?"\n" {
 193     handle_syncline (yytext + sizeof "#line " - 1, *loc);
 194   }
 195 }
 196
 197
 198   /*----------------------------.
 199   | Scanning Bison directives.  |
 200   `----------------------------*/
 201
 202   /* For directives that are also command line options, the regex must be
 203         "%..."
 204      after "[-_]"s are removed, and the directive must match the --long
 205      option name, with a single string argument.  Otherwise, add exceptions
 206      to ../build-aux/cross-options.pl.  */
 207
 208 <INITIAL>
 209 {
 210   "%binary"                         return PERCENT_NONASSOC;
 211   "%code"                           return PERCENT_CODE;
 212   "%debug"                          RETURN_PERCENT_FLAG("parse.trace");
 213   "%default-prec"                   return PERCENT_DEFAULT_PREC;
 214   "%define"                         return PERCENT_DEFINE;
 215   "%defines"                        return PERCENT_DEFINES;
 216   "%destructor"                     return PERCENT_DESTRUCTOR;
 217   "%dprec"                          return PERCENT_DPREC;
 218   "%empty"                          return PERCENT_EMPTY;
 219   "%error-verbose"                  return PERCENT_ERROR_VERBOSE;
 220   "%expect"                         return PERCENT_EXPECT;
 221   "%expect-rr"                      return PERCENT_EXPECT_RR;
 222   "%file-prefix"                    return PERCENT_FILE_PREFIX;
 223   "%fixed-output-files"             return PERCENT_YACC;
 224   "%initial-action"                 return PERCENT_INITIAL_ACTION;
 225   "%glr-parser"                     return PERCENT_GLR_PARSER;
 226   "%language"                       return PERCENT_LANGUAGE;
 227   "%left"                           return PERCENT_LEFT;
 228   "%lex-param"                      RETURN_PERCENT_PARAM(lex);
 229   "%locations"                      RETURN_PERCENT_FLAG("locations");
 230   "%merge"                          return PERCENT_MERGE;
 231   "%name-prefix"                    return PERCENT_NAME_PREFIX;
 232   "%no-default-prec"                return PERCENT_NO_DEFAULT_PREC;
 233   "%no-lines"                       return PERCENT_NO_LINES;
 234   "%nonassoc"                       return PERCENT_NONASSOC;
 235   "%nondeterministic-parser"        return PERCENT_NONDETERMINISTIC_PARSER;
 236   "%nterm"                          return PERCENT_NTERM;
 237   "%output"                         return PERCENT_OUTPUT;
 238   "%param"                          RETURN_PERCENT_PARAM(both);
 239   "%parse-param"                    RETURN_PERCENT_PARAM(parse);
 240   "%prec"                           return PERCENT_PREC;
 241   "%precedence"                     return PERCENT_PRECEDENCE;
 242   "%printer"                        return PERCENT_PRINTER;
 243   "%pure-parser"                    RETURN_PERCENT_FLAG("api.pure");
 244   "%require"                        return PERCENT_REQUIRE;
 245   "%right"                          return PERCENT_RIGHT;
 246   "%skeleton"                       return PERCENT_SKELETON;
 247   "%start"                          return PERCENT_START;
 248   "%term"                           return PERCENT_TOKEN;
 249   "%token"                          return PERCENT_TOKEN;
 250   "%token-table"                    return PERCENT_TOKEN_TABLE;
 251   "%type"                           return PERCENT_TYPE;
 252   "%union"                          return PERCENT_UNION;
 253   "%verbose"                        return PERCENT_VERBOSE;
 254   "%yacc"                           return PERCENT_YACC;
 255
 256   /* deprecated */
 257   "%default"[-_]"prec"              DEPRECATED("%default-prec");
 258   "%error"[-_]"verbose"             DEPRECATED("%define parse.error verbose");
 259   "%expect"[-_]"rr"                 DEPRECATED("%expect-rr");
 260   "%file-prefix"{eqopt}             DEPRECATED("%file-prefix");
 261   "%fixed"[-_]"output"[-_]"files"   DEPRECATED("%fixed-output-files");
 262   "%name"[-_]"prefix"{eqopt}        DEPRECATED("%name-prefix");
 263   "%no"[-_]"default"[-_]"prec"      DEPRECATED("%no-default-prec");
 264   "%no"[-_]"lines"                  DEPRECATED("%no-lines");
 265   "%output"{eqopt}                  DEPRECATED("%output");
 266   "%pure"[-_]"parser"               DEPRECATED("%pure-parser");
 267   "%token"[-_]"table"               DEPRECATED("%token-table");
 268
 269   "%"{id}|"%"{notletter}([[:graph:]])+ {
 270     complain (loc, complaint, _("invalid directive: %s"), quote (yytext));
 271   }
 272
 273   "="                     return EQUAL;
 274   "|"                     return PIPE;
 275   ";"                     return SEMICOLON;
 276
 277   {id} {
 278     val->uniqstr = uniqstr_new (yytext);
 279     id_loc = *loc;
 280     bracketed_id_str = NULL;
 281     BEGIN SC_AFTER_IDENTIFIER;
 282   }
 283
 284   {int} {
 285     val->integer = scan_integer (yytext, 10, *loc);
 286     return INT;
 287   }
 288   0[xX][0-9abcdefABCDEF]+ {
 289     val->integer = scan_integer (yytext, 16, *loc);
 290     return INT;
 291   }
 292
 293   /* Identifiers may not start with a digit.  Yet, don't silently
 294      accept "1FOO" as "1 FOO".  */
 295   {int}{id} {
 296     complain (loc, complaint, _("invalid identifier: %s"), quote (yytext));
 297   }
 298
 299   /* Characters.  */
 300   "'"         token_start = loc->start; BEGIN SC_ESCAPED_CHARACTER;
 301
 302   /* Strings. */
 303   "\""        token_start = loc->start; BEGIN SC_ESCAPED_STRING;
 304
 305   /* Prologue. */
 306   "%{"        code_start = loc->start; BEGIN SC_PROLOGUE;
 307
 308   /* Code in between braces.  */
 309   "{" {
 310     STRING_GROW;
 311     nesting = 0;
 312     code_start = loc->start;
 313     BEGIN SC_BRACED_CODE;
 314   }
 315
 316   /* Semantic predicate. */
 317   "%?"[ \f\n\t\v]*"{" {
 318     nesting = 0;
 319     code_start = loc->start;
 320     BEGIN SC_PREDICATE;
 321   }
 322
 323   /* A type. */
 324   "<*>"       return TAG_ANY;
 325   "<>"        return TAG_NONE;
 326   "<"         {
 327     nesting = 0;
 328     token_start = loc->start;
 329     BEGIN SC_TAG;
 330   }
 331
 332   "%%" {
 333     static int percent_percent_count;
 334     if (++percent_percent_count == 2)
 335       BEGIN SC_EPILOGUE;
 336     return PERCENT_PERCENT;
 337   }
 338
 339   "[" {
 340     bracketed_id_str = NULL;
 341     bracketed_id_start = loc->start;
 342     bracketed_id_context_state = YY_START;
 343     BEGIN SC_BRACKETED_ID;
 344   }
 345
 346   [^\[%A-Za-z0-9_<>{}\"\'*;|=/, \f\n\t\v]+|. {
 347     complain (loc, complaint, "%s: %s",
 348               ngettext ("invalid character", "invalid characters", yyleng),
 349               quote_mem (yytext, yyleng));
 350   }
 351
 352   <<EOF>> {
 353     loc->start = loc->end = scanner_cursor;
 354     yyterminate ();
 355   }
 356 }
 357
 358
 359   /*--------------------------------------------------------------.
 360   | Supporting \0 complexifies our implementation for no expected |
 361   | added value.                                                  |
 362   `--------------------------------------------------------------*/
 363
 364 <SC_ESCAPED_CHARACTER,SC_ESCAPED_STRING,SC_TAG>
 365 {
 366   \0        complain (loc, complaint, _("invalid null character"));
 367 }
 368
 369
 370   /*-----------------------------------------------------------------.
 371   | Scanning after an identifier, checking whether a colon is next.  |
 372   `-----------------------------------------------------------------*/
 373
 374 <SC_AFTER_IDENTIFIER>
 375 {
 376   "[" {
 377     if (bracketed_id_str)
 378       {
 379         ROLLBACK_CURRENT_TOKEN;
 380         BEGIN SC_RETURN_BRACKETED_ID;
 381         *loc = id_loc;
 382         return ID;
 383       }
 384     else
 385       {
 386         bracketed_id_start = loc->start;
 387         bracketed_id_context_state = YY_START;
 388         BEGIN SC_BRACKETED_ID;
 389       }
 390   }
 391   ":" {
 392     BEGIN (bracketed_id_str ? SC_RETURN_BRACKETED_ID : INITIAL);
 393     *loc = id_loc;
 394     return ID_COLON;
 395   }
 396   . {
 397     ROLLBACK_CURRENT_TOKEN;
 398     BEGIN (bracketed_id_str ? SC_RETURN_BRACKETED_ID : INITIAL);
 399     *loc = id_loc;
 400     return ID;
 401   }
 402   <<EOF>> {
 403     BEGIN (bracketed_id_str ? SC_RETURN_BRACKETED_ID : INITIAL);
 404     *loc = id_loc;
 405     return ID;
 406   }
 407 }
 408
 409   /*--------------------------------.
 410   | Scanning bracketed identifiers. |
 411   `--------------------------------*/
 412
 413 <SC_BRACKETED_ID>
 414 {
 415   {id} {
 416     if (bracketed_id_str)
 417       {
 418         complain (loc, complaint,
 419                   _("unexpected identifier in bracketed name: %s"),
 420                   quote (yytext));
 421       }
 422     else
 423       {
 424         bracketed_id_str = uniqstr_new (yytext);
 425         bracketed_id_loc = *loc;
 426       }
 427   }
 428   "]" {
 429     BEGIN bracketed_id_context_state;
 430     if (bracketed_id_str)
 431       {
 432         if (INITIAL == bracketed_id_context_state)
 433           {
 434             val->uniqstr = bracketed_id_str;
 435             bracketed_id_str = 0;
 436             *loc = bracketed_id_loc;
 437             return BRACKETED_ID;
 438           }
 439       }
 440     else
 441       complain (loc, complaint, _("an identifier expected"));
 442   }
 443
 444   [^\].A-Za-z0-9_/ \f\n\t\v]+|. {
 445     complain (loc, complaint, "%s: %s",
 446               ngettext ("invalid character in bracketed name",
 447                         "invalid characters in bracketed name", yyleng),
 448               quote_mem (yytext, yyleng));
 449   }
 450
 451   <<EOF>> {
 452     BEGIN bracketed_id_context_state;
 453     unexpected_eof (bracketed_id_start, "]");
 454   }
 455 }
 456
 457 <SC_RETURN_BRACKETED_ID>
 458 {
 459   . {
 460     ROLLBACK_CURRENT_TOKEN;
 461     val->uniqstr = bracketed_id_str;
 462     bracketed_id_str = 0;
 463     *loc = bracketed_id_loc;
 464     BEGIN INITIAL;
 465     return BRACKETED_ID;
 466   }
 467 }
 468
 469
 470   /*---------------------------------------------------------------.
 471   | Scanning a Yacc comment.  The initial '/ *' is already eaten.  |
 472   `---------------------------------------------------------------*/
 473
 474 <SC_YACC_COMMENT>
 475 {
 476   "*/"     BEGIN context_state;
 477   .|\n     continue;
 478   <<EOF>>  unexpected_eof (token_start, "*/"); BEGIN context_state;
 479 }
 480
 481
 482   /*------------------------------------------------------------.
 483   | Scanning a C comment.  The initial '/ *' is already eaten.  |
 484   `------------------------------------------------------------*/
 485
 486 <SC_COMMENT>
 487 {
 488   "*"{splice}"/"  STRING_GROW; BEGIN context_state;
 489   <<EOF>>         unexpected_eof (token_start, "*/"); BEGIN context_state;
 490 }
 491
 492
 493   /*--------------------------------------------------------------.
 494   | Scanning a line comment.  The initial '//' is already eaten.  |
 495   `--------------------------------------------------------------*/
 496
 497 <SC_LINE_COMMENT>
 498 {
 499   "\n"           STRING_GROW; BEGIN context_state;
 500   {splice}       STRING_GROW;
 501   <<EOF>>        BEGIN context_state;
 502 }
 503
 504
 505   /*------------------------------------------------.
 506   | Scanning a Bison string, including its escapes. |
 507   | The initial quote is already eaten.             |
 508   `------------------------------------------------*/
 509
 510 <SC_ESCAPED_STRING>
 511 {
 512   "\"" {
 513     STRING_FINISH;
 514     loc->start = token_start;
 515     val->chars = last_string;
 516     BEGIN INITIAL;
 517     return STRING;
 518   }
 519   <<EOF>>   unexpected_eof (token_start, "\"");
 520   "\n"      unexpected_newline (token_start, "\"");
 521 }
 522
 523   /*----------------------------------------------------------.
 524   | Scanning a Bison character literal, decoding its escapes. |
 525   | The initial quote is already eaten.                       |
 526   `----------------------------------------------------------*/
 527
 528 <SC_ESCAPED_CHARACTER>
 529 {
 530   "'" {
 531     STRING_FINISH;
 532     loc->start = token_start;
 533     val->character = last_string[0];
 534
 535     /* FIXME: Eventually, make these errors.  */
 536     if (last_string[0] == '\0')
 537     {
 538       complain (loc, Wother, _("empty character literal"));
 539       /* '\0' seems dangerous even if we are about to complain.  */
 540       val->character = '\'';
 541     }
 542     else if (last_string[1] != '\0')
 543       complain (loc, Wother,
 544                 _("extra characters in character literal"));
 545     STRING_FREE;
 546     BEGIN INITIAL;
 547     return CHAR;
 548   }
 549   "\n"      unexpected_newline (token_start, "'");
 550   <<EOF>>   unexpected_eof (token_start, "'");
 551 }
 552
 553
 554
 555   /*--------------------------------------------------------------.
 556   | Scanning a tag.  The initial angle bracket is already eaten.  |
 557   `--------------------------------------------------------------*/
 558
 559 <SC_TAG>
 560 {
 561   ">" {
 562     --nesting;
 563     if (nesting < 0)
 564       {
 565         STRING_FINISH;
 566         loc->start = token_start;
 567         val->uniqstr = uniqstr_new (last_string);
 568         STRING_FREE;
 569         BEGIN INITIAL;
 570         return TAG;
 571       }
 572     STRING_GROW;
 573   }
 574
 575   ([^<>]|->)+ STRING_GROW;
 576   "<"+   STRING_GROW; nesting += yyleng;
 577
 578   <<EOF>>   unexpected_eof (token_start, ">");
 579 }
 580
 581   /*----------------------------.
 582   | Decode escaped characters.  |
 583   `----------------------------*/
 584
 585 <SC_ESCAPED_STRING,SC_ESCAPED_CHARACTER>
 586 {
 587   \\[0-7]{1,3} {
 588     unsigned long int c = strtoul (yytext + 1, NULL, 8);
 589     if (!c || UCHAR_MAX < c)
 590       complain (loc, complaint, _("invalid number after \\-escape: %s"),
 591                    yytext+1);
 592     else
 593       obstack_1grow (&obstack_for_string, c);
 594   }
 595
 596   \\x[0-9abcdefABCDEF]+ {
 597     verify (UCHAR_MAX < ULONG_MAX);
 598     unsigned long int c = strtoul (yytext + 2, NULL, 16);
 599     if (!c || UCHAR_MAX < c)
 600       complain (loc, complaint, _("invalid number after \\-escape: %s"),
 601                    yytext+1);
 602     else
 603       obstack_1grow (&obstack_for_string, c);
 604   }
 605
 606   \\a   obstack_1grow (&obstack_for_string, '\a');
 607   \\b   obstack_1grow (&obstack_for_string, '\b');
 608   \\f   obstack_1grow (&obstack_for_string, '\f');
 609   \\n   obstack_1grow (&obstack_for_string, '\n');
 610   \\r   obstack_1grow (&obstack_for_string, '\r');
 611   \\t   obstack_1grow (&obstack_for_string, '\t');
 612   \\v   obstack_1grow (&obstack_for_string, '\v');
 613
 614   /* \\[\"\'?\\] would be shorter, but it confuses xgettext.  */
 615   \\("\""|"'"|"?"|"\\")  obstack_1grow (&obstack_for_string, yytext[1]);
 616
 617   \\(u|U[0-9abcdefABCDEF]{4})[0-9abcdefABCDEF]{4} {
 618     int c = convert_ucn_to_byte (yytext);
 619     if (c <= 0)
 620       complain (loc, complaint, _("invalid number after \\-escape: %s"),
 621                    yytext+1);
 622     else
 623       obstack_1grow (&obstack_for_string, c);
 624   }
 625   \\(.|\n)      {
 626     char const *p = yytext + 1;
 627     /* Quote only if escaping won't make the character visible.  */
 628     if (c_isspace ((unsigned char) *p) && c_isprint ((unsigned char) *p))
 629       p = quote (p);
 630     else
 631       p = quotearg_style_mem (escape_quoting_style, p, 1);
 632     complain (loc, complaint, _("invalid character after \\-escape: %s"),
 633                  p);
 634   }
 635 }
 636
 637   /*--------------------------------------------.
 638   | Scanning user-code characters and strings.  |
 639   `--------------------------------------------*/
 640
 641 <SC_CHARACTER,SC_STRING>
 642 {
 643   {splice}|\\{splice}[^\n\[\]]  STRING_GROW;
 644 }
 645
 646 <SC_CHARACTER>
 647 {
 648   "'"           STRING_GROW; BEGIN context_state;
 649   \n            unexpected_newline (token_start, "'");
 650   <<EOF>>       unexpected_eof (token_start, "'");
 651 }
 652
 653 <SC_STRING>
 654 {
 655   "\""          STRING_GROW; BEGIN context_state;
 656   \n            unexpected_newline (token_start, "\"");
 657   <<EOF>>       unexpected_eof (token_start, "\"");
 658 }
 659
 660
 661   /*---------------------------------------------------.
 662   | Strings, comments etc. can be found in user code.  |
 663   `---------------------------------------------------*/
 664
 665 <SC_BRACED_CODE,SC_PROLOGUE,SC_EPILOGUE,SC_PREDICATE>
 666 {
 667   "'" {
 668     STRING_GROW;
 669     context_state = YY_START;
 670     token_start = loc->start;
 671     BEGIN SC_CHARACTER;
 672   }
 673   "\"" {
 674     STRING_GROW;
 675     context_state = YY_START;
 676     token_start = loc->start;
 677     BEGIN SC_STRING;
 678   }
 679   "/"{splice}"*" {
 680     STRING_GROW;
 681     context_state = YY_START;
 682     token_start = loc->start;
 683     BEGIN SC_COMMENT;
 684   }
 685   "/"{splice}"/" {
 686     STRING_GROW;
 687     context_state = YY_START;
 688     BEGIN SC_LINE_COMMENT;
 689   }
 690 }
 691
 692
 693
 694   /*-----------------------------------------------------------.
 695   | Scanning some code in braces (actions, predicates). The    |
 696   | initial "{" is already eaten.                              |
 697   `-----------------------------------------------------------*/
 698
 699 <SC_BRACED_CODE,SC_PREDICATE>
 700 {
 701   "{"|"<"{splice}"%"  STRING_GROW; nesting++;
 702   "%"{splice}">"      STRING_GROW; nesting--;
 703
 704   /* Tokenize '<<%' correctly (as '<<' '%') rather than incorrrectly
 705      (as '<' '<%').  */
 706   "<"{splice}"<"  STRING_GROW;
 707
 708   <<EOF>>   unexpected_eof (code_start, "}");
 709 }
 710
 711 <SC_BRACED_CODE>
 712 {
 713   "}" {
 714     obstack_1grow (&obstack_for_string, '}');
 715
 716     --nesting;
 717     if (nesting < 0)
 718       {
 719         STRING_FINISH;
 720         loc->start = code_start;
 721         val->code = last_string;
 722         BEGIN INITIAL;
 723         return BRACED_CODE;
 724       }
 725   }
 726 }
 727
 728 <SC_PREDICATE>
 729 {
 730   "}" {
 731     --nesting;
 732     if (nesting < 0)
 733       {
 734         STRING_FINISH;
 735         loc->start = code_start;
 736         val->code = last_string;
 737         BEGIN INITIAL;
 738         return BRACED_PREDICATE;
 739       }
 740     else
 741       obstack_1grow (&obstack_for_string, '}');
 742   }
 743 }
 744
 745   /*--------------------------------------------------------------.
 746   | Scanning some prologue: from "%{" (already scanned) to "%}".  |
 747   `--------------------------------------------------------------*/
 748
 749 <SC_PROLOGUE>
 750 {
 751   "%}" {
 752     STRING_FINISH;
 753     loc->start = code_start;
 754     val->chars = last_string;
 755     BEGIN INITIAL;
 756     return PROLOGUE;
 757   }
 758
 759   <<EOF>>   unexpected_eof (code_start, "%}");
 760 }
 761
 762
 763   /*---------------------------------------------------------------.
 764   | Scanning the epilogue (everything after the second "%%", which |
 765   | has already been eaten).                                       |
 766   `---------------------------------------------------------------*/
 767
 768 <SC_EPILOGUE>
 769 {
 770   <<EOF>> {
 771     STRING_FINISH;
 772     loc->start = code_start;
 773     val->chars = last_string;
 774     BEGIN INITIAL;
 775     return EPILOGUE;
 776   }
 777 }
 778
 779
 780   /*-----------------------------------------------------.
 781   | By default, grow the string obstack with the input.  |
 782   `-----------------------------------------------------*/
 783
 784 <SC_COMMENT,SC_LINE_COMMENT,SC_BRACED_CODE,SC_PREDICATE,SC_PROLOGUE,SC_EPILOGUE,SC_STRING,SC_CHARACTER,SC_ESCAPED_STRING,SC_ESCAPED_CHARACTER>. |
 785   <SC_COMMENT,SC_LINE_COMMENT,SC_BRACED_CODE,SC_PREDICATE,SC_PROLOGUE,SC_EPILOGUE>\n    STRING_GROW;
 786
 787 %%
 788
 789 /* Read bytes from FP into buffer BUF of size SIZE.  Return the
 790    number of bytes read.  Remove '\r' from input, treating \r\n
 791    and isolated \r as \n.  */
 792
 793 static size_t
 794 no_cr_read (FILE *fp, char *buf, size_t size)
 795 {
 796   size_t bytes_read = fread (buf, 1, size, fp);
 797   if (bytes_read)
 798     {
 799       char *w = memchr (buf, '\r', bytes_read);
 800       if (w)
 801         {
 802           char const *r = ++w;
 803           char const *lim = buf + bytes_read;
 804
 805           for (;;)
 806             {
 807               /* Found an '\r'.  Treat it like '\n', but ignore any
 808                  '\n' that immediately follows.  */
 809               w[-1] = '\n';
 810               if (r == lim)
 811                 {
 812                   int ch = getc (fp);
 813                   if (ch != '\n' && ungetc (ch, fp) != ch)
 814                     break;
 815                 }
 816               else if (*r == '\n')
 817                 r++;
 818
 819               /* Copy until the next '\r'.  */
 820               do
 821                 {
 822                   if (r == lim)
 823                     return w - buf;
 824                 }
 825               while ((*w++ = *r++) != '\r');
 826             }
 827
 828           return w - buf;
 829         }
 830     }
 831
 832   return bytes_read;
 833 }
 834
 835
 836
 837 /*------------------------------------------------------.
 838 | Scan NUMBER for a base-BASE integer at location LOC.  |
 839 `------------------------------------------------------*/
 840
 841 static unsigned long int
 842 scan_integer (char const *number, int base, location loc)
 843 {
 844   verify (INT_MAX < ULONG_MAX);
 845   unsigned long int num = strtoul (number, NULL, base);
 846
 847   if (INT_MAX < num)
 848     {
 849       complain (&loc, complaint, _("integer out of range: %s"),
 850                    quote (number));
 851       num = INT_MAX;
 852     }
 853
 854   return num;
 855 }
 856
 857
 858 /*------------------------------------------------------------------.
 859 | Convert universal character name UCN to a single-byte character,  |
 860 | and return that character.  Return -1 if UCN does not correspond  |
 861 | to a single-byte character.                                       |
 862 `------------------------------------------------------------------*/
 863
 864 static int
 865 convert_ucn_to_byte (char const *ucn)
 866 {
 867   verify (UCHAR_MAX <= INT_MAX);
 868   unsigned long int code = strtoul (ucn + 2, NULL, 16);
 869
 870   /* FIXME: Currently we assume Unicode-compatible unibyte characters
 871      on ASCII hosts (i.e., Latin-1 on hosts with 8-bit bytes).  On
 872      non-ASCII hosts we support only the portable C character set.
 873      These limitations should be removed once we add support for
 874      multibyte characters.  */
 875
 876   if (UCHAR_MAX < code)
 877     return -1;
 878
 879 #if ! ('$' == 0x24 && '@' == 0x40 && '`' == 0x60 && '~' == 0x7e)
 880   {
 881     /* A non-ASCII host.  Use CODE to index into a table of the C
 882        basic execution character set, which is guaranteed to exist on
 883        all Standard C platforms.  This table also includes '$', '@',
 884        and '`', which are not in the basic execution character set but
 885        which are unibyte characters on all the platforms that we know
 886        about.  */
 887     static signed char const table[] =
 888       {
 889         '\0',   -1,   -1,   -1,   -1,   -1,   -1, '\a',
 890         '\b', '\t', '\n', '\v', '\f', '\r',   -1,   -1,
 891           -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
 892           -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
 893          ' ',  '!',  '"',  '#',  '$',  '%',  '&', '\'',
 894          '(',  ')',  '*',  '+',  ',',  '-',  '.',  '/',
 895          '0',  '1',  '2',  '3',  '4',  '5',  '6',  '7',
 896          '8',  '9',  ':',  ';',  '<',  '=',  '>',  '?',
 897          '@',  'A',  'B',  'C',  'D',  'E',  'F',  'G',
 898          'H',  'I',  'J',  'K',  'L',  'M',  'N',  'O',
 899          'P',  'Q',  'R',  'S',  'T',  'U',  'V',  'W',
 900          'X',  'Y',  'Z',  '[', '\\',  ']',  '^',  '_',
 901          '`',  'a',  'b',  'c',  'd',  'e',  'f',  'g',
 902          'h',  'i',  'j',  'k',  'l',  'm',  'n',  'o',
 903          'p',  'q',  'r',  's',  't',  'u',  'v',  'w',
 904          'x',  'y',  'z',  '{',  '|',  '}',  '~'
 905       };
 906
 907     code = code < sizeof table ? table[code] : -1;
 908   }
 909 #endif
 910
 911   return code;
 912 }
 913
 914
 915 /*---------------------------------------------------------------------.
 916 | Handle '#line INT( "FILE")?\n'.  ARGS has already skipped '#line '.  |
 917 `---------------------------------------------------------------------*/
 918
 919 static void
 920 handle_syncline (char *args, location loc)
 921 {
 922   char *file;
 923   unsigned long int lineno = strtoul (args, &file, 10);
 924   if (INT_MAX <= lineno)
 925     {
 926       complain (&loc, Wother, _("line number overflow"));
 927       lineno = INT_MAX;
 928     }
 929
 930   file = strchr (file, '"');
 931   if (file)
 932     {
 933       *strchr (file + 1, '"') = '\0';
 934       current_file = uniqstr_new (file + 1);
 935     }
 936   boundary_set (&scanner_cursor, current_file, lineno, 1);
 937 }
 938
 939
 940 /*----------------------------------------------------------------.
 941 | For a token or comment starting at START, report message MSGID, |
 942 | which should say that an end marker was found before the        |
 943 | expected TOKEN_END. Then, pretend that TOKEN_END was found.     |
 944 `----------------------------------------------------------------*/
 945
 946 static void
 947 unexpected_end (boundary start, char const *msgid, char const *token_end)
 948 {
 949   location loc;
 950   loc.start = start;
 951   loc.end = scanner_cursor;
 952   size_t i = strlen (token_end);
 953
 954 /* Adjust scanner cursor so that any later message does not count
 955      the characters about to be inserted.  */
 956   scanner_cursor.column -= i;
 957
 958   while (i != 0)
 959     unput (token_end[--i]);
 960
 961   token_end = quote (token_end);
 962   /* Instead of '\'', display "'".  */
 963   if (STREQ (token_end, "'\\''"))
 964     token_end = "\"'\"";
 965   complain (&loc, complaint, _(msgid), token_end);
 966 }
 967
 968
 969 /*------------------------------------------------------------------------.
 970 | Report an unexpected EOF in a token or comment starting at START.       |
 971 | An end of file was encountered and the expected TOKEN_END was missing.  |
 972 | After reporting the problem, pretend that TOKEN_END was found.          |
 973 `------------------------------------------------------------------------*/
 974
 975 static void
 976 unexpected_eof (boundary start, char const *token_end)
 977 {
 978   unexpected_end (start, N_("missing %s at end of file"), token_end);
 979 }
 980
 981
 982 /*----------------------------------------.
 983 | Likewise, but for unexpected newlines.  |
 984 `----------------------------------------*/
 985
 986 static void
 987 unexpected_newline (boundary start, char const *token_end)
 988 {
 989   unexpected_end (start, N_("missing %s at end of line"), token_end);
 990 }
 991
 992
 993 /*-------------------------.
 994 | Initialize the scanner.  |
 995 `-------------------------*/
 996
 997 void
 998 gram_scanner_initialize (void)
 999 {
1000   obstack_init (&obstack_for_string);
1001 }
1002
1003
1004 /*-----------------------------------------------.
1005 | Free all the memory allocated to the scanner.  |
1006 `-----------------------------------------------*/
1007
1008 void
1009 gram_scanner_free (void)
1010 {
1011   obstack_free (&obstack_for_string, 0);
1012   /* Reclaim Flex's buffers.  */
1013   yylex_destroy ();
1014 }