src/scan-gram.l

/* Bison Grammar Scanner                             -*- C -*-
   Copyright (C) 2002 Free Software Foundation, Inc.

   This file is part of Bison, the GNU Compiler Compiler.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307  USA
*/

%option debug nodefault noyywrap nounput never-interactive stack
%option prefix="gram_" outfile="lex.yy.c"

%{
#include "system.h"
#include "complain.h"
#include "quote.h"
#include "getargs.h"
#include "gram.h"
#include "reader.h"

/* Each time we match a string, move the end cursor to its end. */
#define YY_USER_INIT				\
do {						\
  LOCATION_RESET (*yylloc);			\
   /* This is only to avoid GCC warnings. */	\
  if (yycontrol) {;};				\
} while (0)

#define YY_USER_ACTION  LOCATION_COLUMNS (*yylloc, yyleng)
#define YY_LINES        LOCATION_LINES (*yylloc, yyleng); lineno += yyleng;
#define YY_STEP         LOCATION_STEP (*yylloc)


/* STRING_OBSTACK -- Used to store all the characters that we need to
   keep (to construct ID, STRINGS etc.).  Use the following macros to
   use it.

   Use YY_OBS_GROW to append what has just been matched, and
   YY_OBS_FINISH to end the string (it puts the ending 0).
   YY_OBS_FINISH also stores this string in LAST_STRING, which can be
   used, and which is used by YY_OBS_FREE to free the last string.  */

static struct obstack string_obstack;
char *last_string;

#define YY_OBS_GROW   \
  obstack_grow (&string_obstack, yytext, yyleng)

#define YY_OBS_FINISH					\
  do {							\
    obstack_1grow (&string_obstack, '\0');		\
    last_string = obstack_finish (&string_obstack);	\
  } while (0)

#define YY_OBS_FREE						\
  do {								\
    obstack_free (&string_obstack, last_string);		\
  } while (0)

void
scanner_last_string_free (void)
{
  YY_OBS_FREE;
}


static int braces_level = 0;
static int percent_percent_count = 0;

static void handle_action_dollar PARAMS ((char *cp, location_t location));
static void handle_destructor_dollar PARAMS ((char *cp, location_t location));
static void handle_at PARAMS ((char *cp));

%}
%x SC_COMMENT
%x SC_STRING SC_CHARACTER
%x SC_ESCAPED_STRING SC_ESCAPED_CHARACTER
%x SC_BRACED_CODE SC_PROLOGUE SC_EPILOGUE

id	 [.a-zA-Z][.a-zA-Z_0-9]*
int 	 [0-9]+
eols     (\n|\r|\n\r|\r\n)+
blanks   [ \t\f]+

%%
%{
  /* At each yylex invocation, mark the current position as the
     start of the next token.  */
#define TR_POS 0
#if TR_POS
  fprintf (stderr, "FOO1: %p: ", yylloc);
  LOCATION_PRINT (stderr, *yylloc);
  fprintf (stderr, "\n");
#endif
  YY_STEP;
#if TR_POS
  fprintf (stderr, "BAR1: ");
  LOCATION_PRINT (stderr, *yylloc);
  fprintf (stderr, "\n");
#endif
%}


  /*----------------------------.
  | Scanning Bison directives.  |
  `----------------------------*/
<INITIAL>
{
  "%binary"               return PERCENT_NONASSOC;
  "%debug"                return PERCENT_DEBUG;
  "%define"               return PERCENT_DEFINE;
  "%defines"              return PERCENT_DEFINES;
  "%destructor"           return PERCENT_DESTRUCTOR;
  "%error"[-_]"verbose"   return PERCENT_ERROR_VERBOSE;
  "%expect"               return PERCENT_EXPECT;
  "%file-prefix"          return PERCENT_FILE_PREFIX;
  "%fixed"[-_]"output"[-_]"files"   return PERCENT_YACC;
  "%left"                 return PERCENT_LEFT;
  "%locations"            return PERCENT_LOCATIONS;
  "%name"[-_]"prefix"     return PERCENT_NAME_PREFIX;
  "%no"[-_]"lines"        return PERCENT_NO_LINES;
  "%nonassoc"             return PERCENT_NONASSOC;
  "%nterm"                return PERCENT_NTERM;
  "%output"               return PERCENT_OUTPUT;
  "%prec"                 return PERCENT_PREC;
  "%pure"[-_]"parser"     return PERCENT_PURE_PARSER;
  "%right"                return PERCENT_RIGHT;
  "%skeleton"             return PERCENT_SKELETON;
  "%start"                return PERCENT_START;
  "%term"                 return PERCENT_TOKEN;
  "%token"                return PERCENT_TOKEN;
  "%token"[-_]"table"     return PERCENT_TOKEN_TABLE;
  "%type"                 return PERCENT_TYPE;
  "%union"                return PERCENT_UNION;
  "%verbose"              return PERCENT_VERBOSE;
  "%yacc"                 return PERCENT_YACC;

  "="                     return EQUAL;
  ":"                     return COLON;
  "|"                     return PIPE;
  ";"                     return SEMICOLON;

  {eols}      YY_LINES; YY_STEP;
  {blanks}    YY_STEP;
  {id}        {
    yylval->symbol = getsym (yytext, *yylloc);
    return ID;
  }

  {int}       yylval->integer = strtol (yytext, 0, 10); return INT;

  /* Characters.  We don't check there is only one.  */
  \'          YY_OBS_GROW; yy_push_state (SC_ESCAPED_CHARACTER);

  /* Strings. */
  \"          YY_OBS_GROW; yy_push_state (SC_ESCAPED_STRING);

  /* Comments. */
  "/*"        yy_push_state (SC_COMMENT);
  "//".*      YY_STEP;

  /* Prologue. */
  "%{"        yy_push_state (SC_PROLOGUE);

  /* Code in between braces.  */
  "{"         YY_OBS_GROW; ++braces_level; yy_push_state (SC_BRACED_CODE);

  /* A type. */
  "<"[^>]+">" {
    obstack_grow (&string_obstack, yytext + 1, yyleng - 2);
    YY_OBS_FINISH;
    yylval->string = last_string;
    return TYPE;
  }


  "%%"   {
    if (++percent_percent_count == 2)
      yy_push_state (SC_EPILOGUE);
    return PERCENT_PERCENT;
  }

  .           {
    LOCATION_PRINT (stderr, *yylloc);
    fprintf (stderr, ": invalid character: `%c'\n", *yytext);
    YY_STEP;
  }
}


  /*------------------------------------------------------------.
  | Whatever the start condition (but those which correspond to |
  | entity `swallowed' by Bison: SC_ESCAPED_STRING and          |
  | SC_ESCAPED_CHARACTER), no M4 character must escape as is.   |
  `------------------------------------------------------------*/

<SC_COMMENT,SC_STRING,SC_CHARACTER,SC_BRACED_CODE,SC_PROLOGUE,SC_EPILOGUE>
{
  \[          if (YY_START != SC_COMMENT) obstack_sgrow (&string_obstack, "@<:@");
  \]          if (YY_START != SC_COMMENT) obstack_sgrow (&string_obstack, "@:>@");
}


  /*-----------------------------------------------------------.
  | Scanning a C comment. The initial `/ *' is already eaten.  |
  `-----------------------------------------------------------*/

<SC_COMMENT>
{
  "*/" { /* End of the comment. */
    if (yy_top_state () == INITIAL)
      {
	YY_STEP;
      }
    else
      {
	YY_OBS_GROW;
      }
    yy_pop_state ();
  }

  [^\[\]*\n\r]+  	if (yy_top_state () != INITIAL) YY_OBS_GROW;
  {eols}	if (yy_top_state () != INITIAL) YY_OBS_GROW; YY_LINES;
  .             /* Stray `*'. */if (yy_top_state () != INITIAL) YY_OBS_GROW;

  <<EOF>> {
    LOCATION_PRINT (stderr, *yylloc);
    fprintf (stderr, ": unexpected end of file in a comment\n");
    yy_pop_state ();
  }
}


  /*----------------------------------------------------------------.
  | Scanning a C string, including its escapes.  The initial `"' is |
  | already eaten.                                                  |
  `----------------------------------------------------------------*/

<SC_ESCAPED_STRING>
{
  \" {
    assert (yy_top_state () == INITIAL);
    YY_OBS_GROW;
    YY_OBS_FINISH;
    yylval->string = last_string;
    yy_pop_state ();
    return STRING;
  }

  [^\"\n\r\\]+      YY_OBS_GROW;

  {eols}    obstack_1grow (&string_obstack, '\n'); YY_LINES;

  <<EOF>> {
    LOCATION_PRINT (stderr, *yylloc);
    fprintf (stderr, ": unexpected end of file in a string\n");
    assert (yy_top_state () == INITIAL);
    YY_OBS_FINISH;
    yylval->string = last_string;
    yy_pop_state ();
    return STRING;
  }
}

  /*---------------------------------------------------------------.
  | Scanning a C character, decoding its escapes.  The initial "'" |
  | is already eaten.                                              |
  `---------------------------------------------------------------*/

<SC_ESCAPED_CHARACTER>
{
  \' {
    YY_OBS_GROW;
    assert (yy_top_state () == INITIAL);
    {
      YY_OBS_FINISH;
      yylval->symbol = getsym (last_string, *yylloc);
      symbol_class_set (yylval->symbol, token_sym);
      symbol_user_token_number_set (yylval->symbol, last_string[1]);
      YY_OBS_FREE;
      yy_pop_state ();
      return ID;
    }
  }

  [^\'\n\r\\]      YY_OBS_GROW;

  {eols}    obstack_1grow (&string_obstack, '\n'); YY_LINES;

  <<EOF>> {
    LOCATION_PRINT (stderr, *yylloc);
    fprintf (stderr, ": unexpected end of file in a character\n");
    assert (yy_top_state () == INITIAL);
    YY_OBS_FINISH;
    yylval->string = last_string;
    yy_pop_state ();
    return CHARACTER;
  }
}


  /*----------------------------.
  | Decode escaped characters.  |
  `----------------------------*/

<SC_ESCAPED_STRING,SC_ESCAPED_CHARACTER>
{
  \\[0-7]{3}		{
    long c = strtol (yytext + 1, 0, 8);
    if (c > 255)
      {
	LOCATION_PRINT (stderr, *yylloc);
	fprintf (stderr, ": invalid escape: %s\n", yytext);
	YY_STEP;
      }
    else
      obstack_1grow (&string_obstack, c);
  }

  \\x[0-9a-fA-F]{2}	{
    obstack_1grow (&string_obstack, strtol (yytext + 2, 0, 16));
  }

  \\a	obstack_1grow (&string_obstack, '\a');
  \\b	obstack_1grow (&string_obstack, '\b');
  \\f	obstack_1grow (&string_obstack, '\f');
  \\n	obstack_1grow (&string_obstack, '\n');
  \\r	obstack_1grow (&string_obstack, '\r');
  \\t	obstack_1grow (&string_obstack, '\t');
  \\v	obstack_1grow (&string_obstack, '\v');
  \\[\\""]   obstack_1grow (&string_obstack, yytext[1]);
  \\.	{
    LOCATION_PRINT (stderr, *yylloc);
    fprintf (stderr, ": unrecognized escape: %s\n", yytext);
    YY_OBS_GROW;
  }
}


  /*----------------------------------------------------------.
  | Scanning a C character without decoding its escapes.  The |
  | initial "'" is already eaten.                             |
  `----------------------------------------------------------*/

<SC_CHARACTER>
{
  \' {
    YY_OBS_GROW;
    assert (yy_top_state () != INITIAL);
    yy_pop_state ();
  }

  [^\[\]\'\n\r\\]      YY_OBS_GROW;
  \\.                  YY_OBS_GROW;

  {eols}               YY_OBS_GROW; YY_LINES;

  <<EOF>> {
    LOCATION_PRINT (stderr, *yylloc);
    fprintf (stderr, ": unexpected end of file in a character\n");
    assert (yy_top_state () != INITIAL);
    yy_pop_state ();
  }
}


  /*----------------------------------------------------------------.
  | Scanning a C string, without decoding its escapes.  The initial |
  | `"' is already eaten.                                           |
  `----------------------------------------------------------------*/

<SC_STRING>
{
  \" {
    assert (yy_top_state () != INITIAL);
    YY_OBS_GROW;
    yy_pop_state ();
  }

  [^\[\]\"\n\r\\]+      YY_OBS_GROW;
  \\.                   YY_OBS_GROW;

  {eols}                YY_OBS_GROW; YY_LINES;

  <<EOF>> {
    LOCATION_PRINT (stderr, *yylloc);
    fprintf (stderr, ": unexpected end of file in a string\n");
    assert (yy_top_state () != INITIAL);
    yy_pop_state ();
  }
}


  /*---------------------------------------------------.
  | Strings, comments etc. can be found in user code.  |
  `---------------------------------------------------*/

<SC_BRACED_CODE,SC_PROLOGUE,SC_EPILOGUE>
{
  /* Characters.  We don't check there is only one.  */
  \'          YY_OBS_GROW; yy_push_state (SC_CHARACTER);

  /* Strings. */
  \"          YY_OBS_GROW; yy_push_state (SC_STRING);

  /* Comments. */
  "/*"        YY_OBS_GROW; yy_push_state (SC_COMMENT);
  "//".*      YY_OBS_GROW;
}


  /*---------------------------------------------------------------.
  | Scanning some code in braces (%union and actions). The initial |
  | "{" is already eaten.                                          |
  `---------------------------------------------------------------*/

<SC_BRACED_CODE>
{
  "}" {
    YY_OBS_GROW;
    if (--braces_level == 0)
      {
	yy_pop_state ();
	YY_OBS_FINISH;
	yylval->string = last_string;
	return BRACED_CODE;
      }
  }

  "{"  	        YY_OBS_GROW; braces_level++;

  "$"("<"[^>]+">")?(-?[0-9]+|"$") {
    switch (current_braced_code)
      {
      case action_braced_code:
	handle_action_dollar (yytext, *yylloc);
	break;

      case destructor_braced_code:
	handle_destructor_dollar (yytext, *yylloc);
	break;
      }
  }
  "@"(-?[0-9]+|"$")               { handle_at (yytext); }

  [^$@\[\]/\'\"\{\}\n\r]+ YY_OBS_GROW;
  {eols}	YY_OBS_GROW; YY_LINES;

  /* A lose $, or /, or etc. */
  .             YY_OBS_GROW;

  <<EOF>> {
    LOCATION_PRINT (stderr, *yylloc);
    fprintf (stderr, ": unexpected end of file in a braced code\n");
    yy_pop_state ();
    YY_OBS_FINISH;
    yylval->string = last_string;
    return BRACED_CODE;
  }

}


  /*--------------------------------------------------------------.
  | Scanning some prologue: from "%{" (already scanned) to "%}".  |
  `--------------------------------------------------------------*/

<SC_PROLOGUE>
{
  "%}" {
    yy_pop_state ();
    YY_OBS_FINISH;
    yylval->string = last_string;
    return PROLOGUE;
  }

  [^%\[\]/\'\"\n\r]+	  YY_OBS_GROW;
  "%"+[^%\}\n\r]+ YY_OBS_GROW;
  {eols}	  YY_OBS_GROW; YY_LINES;

  <<EOF>> {
    LOCATION_PRINT (stderr, *yylloc);
    fprintf (stderr, ": unexpected end of file in a prologue\n");
    yy_pop_state ();
    YY_OBS_FINISH;
    yylval->string = last_string;
    return PROLOGUE;
  }

}


  /*---------------------------------------------------------------.
  | Scanning the epilogue (everything after the second "%%", which |
  | has already been eaten.                                        |
  `---------------------------------------------------------------*/

<SC_EPILOGUE>
{
  ([^\[\]]|{eols})+  YY_OBS_GROW;

  <<EOF>> {
    yy_pop_state ();
    YY_OBS_FINISH;
    yylval->string = last_string;
    return EPILOGUE;
  }
}


%%

/*------------------------------------------------------------------.
| CP is pointing to a wannabee semantic value (i.e., a `$').        |
|                                                                   |
| Possible inputs: $[<TYPENAME>]($|integer)                         |
|                                                                   |
| Output to the STRING_OBSTACK a reference to this semantic value.  |
`------------------------------------------------------------------*/

static void
handle_action_dollar (char *cp, location_t location)
{
  const char *type_name = NULL;

  ++cp;

  /* Get the type name if explicit. */
  if (*cp == '<')
    {
      type_name = ++cp;
      while (*cp != '>')
	++cp;
      *cp = '\0';
      ++cp;
    }

  if (*cp == '$')
    {
      if (!type_name)
	type_name = symbol_list_n_type_name_get (current_rule, location, 0);
      if (!type_name && typed)
	complain_at (location, _("$$ of `%s' has no declared type"),
		     current_rule->sym->tag);
      if (!type_name)
	type_name = "";
      obstack_fgrow1 (&string_obstack,
		      "]b4_lhs_value([%s])[", type_name);
    }
  else if (isdigit (*cp) || *cp == '-')
    {
      /* RULE_LENGTH is the number of values in the current rule so
	 far, which says where to find `$0' with respect to the top of
	 the stack.  It is not the same as the rule->length in the
	 case of mid rule actions.  */
      int rule_length = symbol_list_length (current_rule->next);
      int n = strtol (cp, &cp, 10);

      if (n > rule_length)
	complain_at (location, _("invalid value: %s%d"), "$", n);
      else
	{
	  if (!type_name && n > 0)
	    type_name = symbol_list_n_type_name_get (current_rule, location,
						     n);
	  if (!type_name && typed)
	    complain_at (location, _("$%d of `%s' has no declared type"),
		      n, current_rule->sym->tag);
	  if (!type_name)
	    type_name = "";
	  obstack_fgrow3 (&string_obstack,
			  "]b4_rhs_value([%d], [%d], [%s])[",
			  rule_length, n, type_name);
	}
    }
  else
    {
      char buf[] = "$c";
      buf[1] = *cp;
      complain_at (location, _("%s is invalid"), quote (buf));
    }
}


/*---------------------------------------------------------------.
| CP is pointing to $$ in a destructor.  This should probably be |
| done once the grammar completely parsed, instead of during its |
| parsing, since that means %type must be specified before       |
| %destructor.                                                   |
`---------------------------------------------------------------*/

static void
handle_destructor_dollar (char *cp, location_t location)
{
  ++cp;
  if (*cp == '$')
    {
      /* FIXME: We should find something more robust.  */
      obstack_sgrow (&string_obstack, "b4_dollar_dollar");
    }
  else
    {
      char buf[] = "$c";
      buf[1] = *cp;
      complain_at (location, _("%s is invalid"), quote (buf));
    }
}

/*-------------------------------------------------------.
| CP is pointing to a location (i.e., a `@').  Output to |
| STRING_OBSTACK a reference to this location.           |
`-------------------------------------------------------*/

static void
handle_at (char *cp)
{
  locations_flag = 1;
  ++cp;

  if (*cp == '$')
    {
      obstack_sgrow (&string_obstack, "]b4_lhs_location[");
    }
  else if (isdigit (*cp) || *cp == '-')
    {
      /* RULE_LENGTH is the number of values in the current rule so
	 far, which says where to find `$0' with respect to the top of
	 the stack.  It is not the same as the rule->length in the
	 case of mid rule actions.  */
      int rule_length = symbol_list_length (current_rule->next);
      int n = strtol (cp, &cp, 10);

      if (n > rule_length)
	complain (_("invalid value: %s%d"), "@", n);
      else
	obstack_fgrow2 (&string_obstack, "]b4_rhs_location([%d], [%d])[",
			rule_length, n);
    }
  else
    {
      char buf[] = "@c";
      buf[1] = *cp;
      complain (_("%s is invalid"), quote (buf));
    }
}

void
scanner_initialize (void)
{
  obstack_init (&string_obstack);
}


void
scanner_free (void)
{
  obstack_free (&string_obstack, 0);
}
Commit	Line	Data
	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
	80	static int braces_level = 0;
	81	static int percent_percent_count = 0;
	82
	83	static void handle_action_dollar PARAMS ((char *cp, location_t location));
	84	static void handle_destructor_dollar PARAMS ((char *cp, location_t location));
	85	static void handle_at PARAMS ((char *cp));
	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	"%error"[-_]"verbose" return PERCENT_ERROR_VERBOSE;
	128	"%expect" return PERCENT_EXPECT;
	129	"%file-prefix" return PERCENT_FILE_PREFIX;
	130	"%fixed"[-_]"output"[-_]"files" return PERCENT_YACC;
	131	"%left" return PERCENT_LEFT;
	132	"%locations" return PERCENT_LOCATIONS;
	133	"%name"[-_]"prefix" return PERCENT_NAME_PREFIX;
	134	"%no"[-_]"lines" return PERCENT_NO_LINES;
	135	"%nonassoc" return PERCENT_NONASSOC;
	136	"%nterm" return PERCENT_NTERM;
	137	"%output" return PERCENT_OUTPUT;
	138	"%prec" return PERCENT_PREC;
	139	"%pure"[-_]"parser" return PERCENT_PURE_PARSER;
	140	"%right" return PERCENT_RIGHT;
	141	"%skeleton" return PERCENT_SKELETON;
	142	"%start" return PERCENT_START;
	143	"%term" return PERCENT_TOKEN;
	144	"%token" return PERCENT_TOKEN;
	145	"%token"[-_]"table" return PERCENT_TOKEN_TABLE;
	146	"%type" return PERCENT_TYPE;
	147	"%union" return PERCENT_UNION;
	148	"%verbose" return PERCENT_VERBOSE;
	149	"%yacc" return PERCENT_YACC;
	150
	151	"=" return EQUAL;
	152	":" return COLON;
	153	"\|" return PIPE;
	154	";" return SEMICOLON;
	155
	156	{eols} YY_LINES; YY_STEP;
	157	{blanks} YY_STEP;
	158	{id} {
	159	yylval->symbol = getsym (yytext, *yylloc);
	160	return ID;
	161	}
	162
	163	{int} yylval->integer = strtol (yytext, 0, 10); return INT;
	164
	165	/* Characters. We don't check there is only one. */
	166	\' YY_OBS_GROW; yy_push_state (SC_ESCAPED_CHARACTER);
	167
	168	/* Strings. */
	169	\" YY_OBS_GROW; yy_push_state (SC_ESCAPED_STRING);
	170
	171	/* Comments. */
	172	"/*" yy_push_state (SC_COMMENT);
	173	"//".* YY_STEP;
	174
	175	/* Prologue. */
	176	"%{" yy_push_state (SC_PROLOGUE);
	177
	178	/* Code in between braces. */
	179	"{" YY_OBS_GROW; ++braces_level; yy_push_state (SC_BRACED_CODE);
	180
	181	/* A type. */
	182	"<"[^>]+">" {
	183	obstack_grow (&string_obstack, yytext + 1, yyleng - 2);
	184	YY_OBS_FINISH;
	185	yylval->string = last_string;
	186	return TYPE;
	187	}
	188
	189
	190	"%%" {
	191	if (++percent_percent_count == 2)
	192	yy_push_state (SC_EPILOGUE);
	193	return PERCENT_PERCENT;
	194	}
	195
	196	. {
	197	LOCATION_PRINT (stderr, *yylloc);
	198	fprintf (stderr, ": invalid character: `%c'\n", *yytext);
	199	YY_STEP;
	200	}
	201	}
	202
	203
	204	/*------------------------------------------------------------.
	205	\| Whatever the start condition (but those which correspond to \|
	206	\| entity `swallowed' by Bison: SC_ESCAPED_STRING and \|
	207	\| SC_ESCAPED_CHARACTER), no M4 character must escape as is. \|
	208	`------------------------------------------------------------*/
	209
	210	<SC_COMMENT,SC_STRING,SC_CHARACTER,SC_BRACED_CODE,SC_PROLOGUE,SC_EPILOGUE>
	211	{
	212	\[ if (YY_START != SC_COMMENT) obstack_sgrow (&string_obstack, "@<:@");
	213	\] if (YY_START != SC_COMMENT) obstack_sgrow (&string_obstack, "@:>@");
	214	}
	215
	216
	217
	218	/*-----------------------------------------------------------.
	219	\| Scanning a C comment. The initial `/ *' is already eaten. \|
	220	`-----------------------------------------------------------*/
	221
	222	<SC_COMMENT>
	223	{
	224	"/" { / End of the comment. */
	225	if (yy_top_state () == INITIAL)
	226	{
	227	YY_STEP;
	228	}
	229	else
	230	{
	231	YY_OBS_GROW;
	232	}
	233	yy_pop_state ();
	234	}
	235
	236	[^\[\]*\n\r]+ if (yy_top_state () != INITIAL) YY_OBS_GROW;
	237	{eols} if (yy_top_state () != INITIAL) YY_OBS_GROW; YY_LINES;
	238	. /* Stray `'. /if (yy_top_state () != INITIAL) YY_OBS_GROW;
	239
	240	<<EOF>> {
	241	LOCATION_PRINT (stderr, *yylloc);
	242	fprintf (stderr, ": unexpected end of file in a comment\n");
	243	yy_pop_state ();
	244	}
	245	}
	246
	247
	248	/*----------------------------------------------------------------.
	249	\| Scanning a C string, including its escapes. The initial `"' is \|
	250	\| already eaten. \|
	251	`----------------------------------------------------------------*/
	252
	253	<SC_ESCAPED_STRING>
	254	{
	255	\" {
	256	assert (yy_top_state () == INITIAL);
	257	YY_OBS_GROW;
	258	YY_OBS_FINISH;
	259	yylval->string = last_string;
	260	yy_pop_state ();
	261	return STRING;
	262	}
	263
	264	[^\"\n\r\\]+ YY_OBS_GROW;
	265
	266	{eols} obstack_1grow (&string_obstack, '\n'); YY_LINES;
	267
	268	<<EOF>> {
	269	LOCATION_PRINT (stderr, *yylloc);
	270	fprintf (stderr, ": unexpected end of file in a string\n");
	271	assert (yy_top_state () == INITIAL);
	272	YY_OBS_FINISH;
	273	yylval->string = last_string;
	274	yy_pop_state ();
	275	return STRING;
	276	}
	277	}
	278
	279	/*---------------------------------------------------------------.
	280	\| Scanning a C character, decoding its escapes. The initial "'" \|
	281	\| is already eaten. \|
	282	`---------------------------------------------------------------*/
	283
	284	<SC_ESCAPED_CHARACTER>
	285	{
	286	\' {
	287	YY_OBS_GROW;
	288	assert (yy_top_state () == INITIAL);
	289	{
	290	YY_OBS_FINISH;
	291	yylval->symbol = getsym (last_string, *yylloc);
	292	symbol_class_set (yylval->symbol, token_sym);
	293	symbol_user_token_number_set (yylval->symbol, last_string[1]);
	294	YY_OBS_FREE;
	295	yy_pop_state ();
	296	return ID;
	297	}
	298	}
	299
	300	[^\'\n\r\\] YY_OBS_GROW;
	301
	302	{eols} obstack_1grow (&string_obstack, '\n'); YY_LINES;
	303
	304	<<EOF>> {
	305	LOCATION_PRINT (stderr, *yylloc);
	306	fprintf (stderr, ": unexpected end of file in a character\n");
	307	assert (yy_top_state () == INITIAL);
	308	YY_OBS_FINISH;
	309	yylval->string = last_string;
	310	yy_pop_state ();
	311	return CHARACTER;
	312	}
	313	}
	314
	315
	316	/*----------------------------.
	317	\| Decode escaped characters. \|
	318	`----------------------------*/
	319
	320	<SC_ESCAPED_STRING,SC_ESCAPED_CHARACTER>
	321	{
	322	\\[0-7]{3} {
	323	long c = strtol (yytext + 1, 0, 8);
	324	if (c > 255)
	325	{
	326	LOCATION_PRINT (stderr, *yylloc);
	327	fprintf (stderr, ": invalid escape: %s\n", yytext);
	328	YY_STEP;
	329	}
	330	else
	331	obstack_1grow (&string_obstack, c);
	332	}
	333
	334	\\x[0-9a-fA-F]{2} {
	335	obstack_1grow (&string_obstack, strtol (yytext + 2, 0, 16));
	336	}
	337
	338	\\a obstack_1grow (&string_obstack, '\a');
	339	\\b obstack_1grow (&string_obstack, '\b');
	340	\\f obstack_1grow (&string_obstack, '\f');
	341	\\n obstack_1grow (&string_obstack, '\n');
	342	\\r obstack_1grow (&string_obstack, '\r');
	343	\\t obstack_1grow (&string_obstack, '\t');
	344	\\v obstack_1grow (&string_obstack, '\v');
	345	\\[\\""] obstack_1grow (&string_obstack, yytext[1]);
	346	\\. {
	347	LOCATION_PRINT (stderr, *yylloc);
	348	fprintf (stderr, ": unrecognized escape: %s\n", yytext);
	349	YY_OBS_GROW;
	350	}
	351	}
	352
	353
	354	/*----------------------------------------------------------.
	355	\| Scanning a C character without decoding its escapes. The \|
	356	\| initial "'" is already eaten. \|
	357	`----------------------------------------------------------*/
	358
	359	<SC_CHARACTER>
	360	{
	361	\' {
	362	YY_OBS_GROW;
	363	assert (yy_top_state () != INITIAL);
	364	yy_pop_state ();
	365	}
	366
	367	[^\[\]\'\n\r\\] YY_OBS_GROW;
	368	\\. YY_OBS_GROW;
	369
	370	{eols} YY_OBS_GROW; YY_LINES;
	371
	372	<<EOF>> {
	373	LOCATION_PRINT (stderr, *yylloc);
	374	fprintf (stderr, ": unexpected end of file in a character\n");
	375	assert (yy_top_state () != INITIAL);
	376	yy_pop_state ();
	377	}
	378	}
	379
	380
	381	/*----------------------------------------------------------------.
	382	\| Scanning a C string, without decoding its escapes. The initial \|
	383	\| `"' is already eaten. \|
	384	`----------------------------------------------------------------*/
	385
	386	<SC_STRING>
	387	{
	388	\" {
	389	assert (yy_top_state () != INITIAL);
	390	YY_OBS_GROW;
	391	yy_pop_state ();
	392	}
	393
	394	[^\[\]\"\n\r\\]+ YY_OBS_GROW;
	395	\\. YY_OBS_GROW;
	396
	397	{eols} YY_OBS_GROW; YY_LINES;
	398
	399	<<EOF>> {
	400	LOCATION_PRINT (stderr, *yylloc);
	401	fprintf (stderr, ": unexpected end of file in a string\n");
	402	assert (yy_top_state () != INITIAL);
	403	yy_pop_state ();
	404	}
	405	}
	406
	407
	408	/*---------------------------------------------------.
	409	\| Strings, comments etc. can be found in user code. \|
	410	`---------------------------------------------------*/
	411
	412	<SC_BRACED_CODE,SC_PROLOGUE,SC_EPILOGUE>
	413	{
	414	/* Characters. We don't check there is only one. */
	415	\' YY_OBS_GROW; yy_push_state (SC_CHARACTER);
	416
	417	/* Strings. */
	418	\" YY_OBS_GROW; yy_push_state (SC_STRING);
	419
	420	/* Comments. */
	421	"/*" YY_OBS_GROW; yy_push_state (SC_COMMENT);
	422	"//".* YY_OBS_GROW;
	423	}
	424
	425
	426	/*---------------------------------------------------------------.
	427	\| Scanning some code in braces (%union and actions). The initial \|
	428	\| "{" is already eaten. \|
	429	`---------------------------------------------------------------*/
	430
	431	<SC_BRACED_CODE>
	432	{
	433	"}" {
	434	YY_OBS_GROW;
	435	if (--braces_level == 0)
	436	{
	437	yy_pop_state ();
	438	YY_OBS_FINISH;
	439	yylval->string = last_string;
	440	return BRACED_CODE;
	441	}
	442	}
	443
	444	"{" YY_OBS_GROW; braces_level++;
	445
	446	"$"("<"[^>]+">")?(-?[0-9]+\|"$") {
	447	switch (current_braced_code)
	448	{
	449	case action_braced_code:
	450	handle_action_dollar (yytext, *yylloc);
	451	break;
	452
	453	case destructor_braced_code:
	454	handle_destructor_dollar (yytext, *yylloc);
	455	break;
	456	}
	457	}
	458	"@"(-?[0-9]+\|"$") { handle_at (yytext); }
	459
	460	[^$@\[\]/\'\"\{\}\n\r]+ YY_OBS_GROW;
	461	{eols} YY_OBS_GROW; YY_LINES;
	462
	463	/* A lose $, or /, or etc. */
	464	. YY_OBS_GROW;
	465
	466	<<EOF>> {
	467	LOCATION_PRINT (stderr, *yylloc);
	468	fprintf (stderr, ": unexpected end of file in a braced code\n");
	469	yy_pop_state ();
	470	YY_OBS_FINISH;
	471	yylval->string = last_string;
	472	return BRACED_CODE;
	473	}
	474
	475	}
	476
	477
	478	/*--------------------------------------------------------------.
	479	\| Scanning some prologue: from "%{" (already scanned) to "%}". \|
	480	`--------------------------------------------------------------*/
	481
	482	<SC_PROLOGUE>
	483	{
	484	"%}" {
	485	yy_pop_state ();
	486	YY_OBS_FINISH;
	487	yylval->string = last_string;
	488	return PROLOGUE;
	489	}
	490
	491	[^%\[\]/\'\"\n\r]+ YY_OBS_GROW;
	492	"%"+[^%\}\n\r]+ YY_OBS_GROW;
	493	{eols} YY_OBS_GROW; YY_LINES;
	494
	495	<<EOF>> {
	496	LOCATION_PRINT (stderr, *yylloc);
	497	fprintf (stderr, ": unexpected end of file in a prologue\n");
	498	yy_pop_state ();
	499	YY_OBS_FINISH;
	500	yylval->string = last_string;
	501	return PROLOGUE;
	502	}
	503
	504	}
	505
	506
	507	/*---------------------------------------------------------------.
	508	\| Scanning the epilogue (everything after the second "%%", which \|
	509	\| has already been eaten. \|
	510	`---------------------------------------------------------------*/
	511
	512	<SC_EPILOGUE>
	513	{
	514	([^\[\]]\|{eols})+ YY_OBS_GROW;
	515
	516	<<EOF>> {
	517	yy_pop_state ();
	518	YY_OBS_FINISH;
	519	yylval->string = last_string;
	520	return EPILOGUE;
	521	}
	522	}
	523
	524
	525	%%
	526
	527	/*------------------------------------------------------------------.
	528	\| CP is pointing to a wannabee semantic value (i.e., a `$'). \|
	529	\| \|
	530	\| Possible inputs: $[<TYPENAME>]($\|integer) \|
	531	\| \|
	532	\| Output to the STRING_OBSTACK a reference to this semantic value. \|
	533	`------------------------------------------------------------------*/
	534
	535	static void
	536	handle_action_dollar (char *cp, location_t location)
	537	{
	538	const char *type_name = NULL;
	539
	540	++cp;
	541
	542	/* Get the type name if explicit. */
	543	if (*cp == '<')
	544	{
	545	type_name = ++cp;
	546	while (*cp != '>')
	547	++cp;
	548	*cp = '\0';
	549	++cp;
	550	}
	551
	552	if (*cp == '$')
	553	{
	554	if (!type_name)
	555	type_name = symbol_list_n_type_name_get (current_rule, location, 0);
	556	if (!type_name && typed)
	557	complain_at (location, _("$$ of `%s' has no declared type"),
	558	current_rule->sym->tag);
	559	if (!type_name)
	560	type_name = "";
	561	obstack_fgrow1 (&string_obstack,
	562	"]b4_lhs_value([%s])[", type_name);
	563	}
	564	else if (isdigit (cp) \|\| cp == '-')
	565	{
	566	/* RULE_LENGTH is the number of values in the current rule so
	567	far, which says where to find `$0' with respect to the top of
	568	the stack. It is not the same as the rule->length in the
	569	case of mid rule actions. */
	570	int rule_length = symbol_list_length (current_rule->next);
	571	int n = strtol (cp, &cp, 10);
	572
	573	if (n > rule_length)
	574	complain_at (location, _("invalid value: %s%d"), "$", n);
	575	else
	576	{
	577	if (!type_name && n > 0)
	578	type_name = symbol_list_n_type_name_get (current_rule, location,
	579	n);
	580	if (!type_name && typed)
	581	complain_at (location, _("$%d of `%s' has no declared type"),
	582	n, current_rule->sym->tag);
	583	if (!type_name)
	584	type_name = "";
	585	obstack_fgrow3 (&string_obstack,
	586	"]b4_rhs_value([%d], [%d], [%s])[",
	587	rule_length, n, type_name);
	588	}
	589	}
	590	else
	591	{
	592	char buf[] = "$c";
	593	buf[1] = *cp;
	594	complain_at (location, _("%s is invalid"), quote (buf));
	595	}
	596	}
	597
	598
	599	/*---------------------------------------------------------------.
	600	\| CP is pointing to $$ in a destructor. This should probably be \|
	601	\| done once the grammar completely parsed, instead of during its \|
	602	\| parsing, since that means %type must be specified before \|
	603	\| %destructor. \|
	604	`---------------------------------------------------------------*/
	605
	606	static void
	607	handle_destructor_dollar (char *cp, location_t location)
	608	{
	609	++cp;
	610	if (*cp == '$')
	611	{
	612	/* FIXME: We should find something more robust. */
	613	obstack_sgrow (&string_obstack, "b4_dollar_dollar");
	614	}
	615	else
	616	{
	617	char buf[] = "$c";
	618	buf[1] = *cp;
	619	complain_at (location, _("%s is invalid"), quote (buf));
	620	}
	621	}
	622
	623	/*-------------------------------------------------------.
	624	\| CP is pointing to a location (i.e., a `@'). Output to \|
	625	\| STRING_OBSTACK a reference to this location. \|
	626	`-------------------------------------------------------*/
	627
	628	static void
	629	handle_at (char *cp)
	630	{
	631	locations_flag = 1;
	632	++cp;
	633
	634	if (*cp == '$')
	635	{
	636	obstack_sgrow (&string_obstack, "]b4_lhs_location[");
	637	}
	638	else if (isdigit (cp) \|\| cp == '-')
	639	{
	640	/* RULE_LENGTH is the number of values in the current rule so
	641	far, which says where to find `$0' with respect to the top of
	642	the stack. It is not the same as the rule->length in the
	643	case of mid rule actions. */
	644	int rule_length = symbol_list_length (current_rule->next);
	645	int n = strtol (cp, &cp, 10);
	646
	647	if (n > rule_length)
	648	complain (_("invalid value: %s%d"), "@", n);
	649	else
	650	obstack_fgrow2 (&string_obstack, "]b4_rhs_location([%d], [%d])[",
	651	rule_length, n);
	652	}
	653	else
	654	{
	655	char buf[] = "@c";
	656	buf[1] = *cp;
	657	complain (_("%s is invalid"), quote (buf));
	658	}
	659	}
	660
	661	void
	662	scanner_initialize (void)
	663	{
	664	obstack_init (&string_obstack);
	665	}
	666
	667
	668	void
	669	scanner_free (void)
	670	{
	671	obstack_free (&string_obstack, 0);
	672	}