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);			\
  yylloc->file = infile;			\
   /* 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);
#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;

/* Within well-formed rules, 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.

   Outside of well-formed rules, RULE_LENGTH has an undefined value.  */
static int rule_length;

static void handle_dollar PARAMS ((braced_code_t code_kind,
				   char *cp, location_t location));
static void handle_at PARAMS ((braced_code_t code_kind,
			       char *cp, location_t location));

%}
%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.  */
  YY_STEP;
%}


  /*----------------------------.
  | Scanning Bison directives.  |
  `----------------------------*/
<INITIAL>
{
  "%binary"               return PERCENT_NONASSOC;
  "%debug"                return PERCENT_DEBUG;
  "%define"               return PERCENT_DEFINE;
  "%defines"              return PERCENT_DEFINES;
  "%destructor"           return PERCENT_DESTRUCTOR;
  "%dprec"		  return PERCENT_DPREC;
  "%error"[-_]"verbose"   return PERCENT_ERROR_VERBOSE;
  "%expect"               return PERCENT_EXPECT;
  "%file-prefix"          return PERCENT_FILE_PREFIX;
  "%fixed"[-_]"output"[-_]"files"   return PERCENT_YACC;
  "%glr-parser"           return PERCENT_GLR_PARSER;
  "%left"                 return PERCENT_LEFT;
  "%locations"            return PERCENT_LOCATIONS;
  "%merge"		  return PERCENT_MERGE;
  "%name"[-_]"prefix"     return PERCENT_NAME_PREFIX;
  "%no"[-_]"lines"        return PERCENT_NO_LINES;
  "%nonassoc"             return PERCENT_NONASSOC;
  "%nterm"                return PERCENT_NTERM;
  "%output"               return PERCENT_OUTPUT;
  "%parse-param"          return PERCENT_PARSE_PARAM;
  "%prec"                 { rule_length--; return PERCENT_PREC; }
  "%printer"              return PERCENT_PRINTER;
  "%pure"[-_]"parser"     return PERCENT_PURE_PARSER;
  "%right"                return PERCENT_RIGHT;
  "%lex-param"            return PERCENT_LEX_PARAM;
  "%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;
  ":"                     { rule_length = 0; return COLON; }
  "|"                     { rule_length = 0; return PIPE; }
  ","                     return COMMA;
  ";"                     return SEMICOLON;

  {eols}      YY_LINES; YY_STEP;
  {blanks}    YY_STEP;
  {id}        {
    yylval->symbol = symbol_get (yytext, *yylloc);
    rule_length++;
    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 ();
    rule_length++;
    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 = symbol_get (last_string, *yylloc);
      symbol_class_set (yylval->symbol, token_sym, *yylloc);
      symbol_user_token_number_set (yylval->symbol,
				    (unsigned char) last_string[1], *yylloc);
      YY_OBS_FREE;
      yy_pop_state ();
      rule_length++;
      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"), quote (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]);
  \\(.|\n)	{
    LOCATION_PRINT (stderr, *yylloc);
    fprintf (stderr, _(": unrecognized escape: %s\n"), quote (yytext));
    YY_OBS_GROW;
  }
  /* FLex wants this rule, in case of a `\<<EOF>>'. */
  \\                   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;
  \\(.|\n)             YY_OBS_GROW;
  /* FLex wants this rule, in case of a `\<<EOF>>'. */
  \\                   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;
  \\(.|\n)              YY_OBS_GROW;
  /* FLex wants this rule, in case of a `\<<EOF>>'. */
  \\                   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;

  /* Not comments. */
  "/"         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;
	rule_length++;
	return BRACED_CODE;
      }
  }

  "{"  	        YY_OBS_GROW; braces_level++;

  "$"("<"[^>]+">")?(-?[0-9]+|"$") { handle_dollar (current_braced_code,
						   yytext, *yylloc); }
  "@"(-?[0-9]+|"$")               { handle_at (current_braced_code,
					       yytext, *yylloc); }

  [^$@\[\]/\'\"\{\}\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;
  "%"                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;
  }
}


%%

/*------------------------------------------------------------------.
| TEXT 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 inline void
handle_action_dollar (char *text, location_t location)
{
  const char *type_name = NULL;
  char *cp = text + 1;

  /* 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 (('0' <= *cp && *cp <= '9') || *cp == '-')
    {
      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
    {
      complain_at (location, _("%s is invalid"), quote (text));
    }
}


/*---------------------------------------------------------------.
| TEXT is expexted tp be $$ in some code associated to a symbol: |
| destructor or printer.                                         |
`---------------------------------------------------------------*/

static inline void
handle_symbol_code_dollar (char *text, location_t location)
{
  char *cp = text + 1;
  if (*cp == '$')
    obstack_sgrow (&string_obstack, "]b4_dollar_dollar[");
  else
    complain_at (location, _("%s is invalid"), quote (text));
}


/*-----------------------------------------------------------------.
| Dispatch onto handle_action_dollar, or handle_destructor_dollar, |
| depending upon CODE_KIND.                                        |
`-----------------------------------------------------------------*/

static void
handle_dollar (braced_code_t braced_code_kind,
	       char *text, location_t location)
{
  switch (braced_code_kind)
    {
    case action_braced_code:
      handle_action_dollar (text, location);
      break;

    case destructor_braced_code:
    case printer_braced_code:
      handle_symbol_code_dollar (text, location);
      break;
    }
}


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

static inline void
handle_action_at (char *text, location_t location)
{
  char *cp = text + 1;
  locations_flag = 1;

  if (*cp == '$')
    {
      obstack_sgrow (&string_obstack, "]b4_lhs_location[");
    }
  else if (('0' <= *cp && *cp <= '9') || *cp == '-')
    {
      int n = strtol (cp, &cp, 10);

      if (n > rule_length)
	complain_at (location, _("invalid value: %s%d"), "@", n);
      else
	obstack_fgrow2 (&string_obstack, "]b4_rhs_location([%d], [%d])[",
			rule_length, n);
    }
  else
    {
      complain_at (location, _("%s is invalid"), quote (text));
    }
}


/*---------------------------------------------------------------.
| TEXT is expexted tp be @$ in some code associated to a symbol: |
| destructor or printer.                                         |
`---------------------------------------------------------------*/

static inline void
handle_symbol_code_at (char *text, location_t location)
{
  char *cp = text + 1;
  if (*cp == '$')
    obstack_sgrow (&string_obstack, "]b4_at_dollar[");
  else
    complain_at (location, _("%s is invalid"), quote (text));
}


/*-------------------------------------------------------------------.
| Dispatch onto handle_action_at, or handle_destructor_at, depending |
| upon CODE_KIND.                                                    |
`-------------------------------------------------------------------*/

static void
handle_at (braced_code_t braced_code_kind,
	   char *text, location_t location)
{
  switch (braced_code_kind)
    {
    case action_braced_code:
      handle_action_at (text, location);
      break;

    case destructor_braced_code:
    case printer_braced_code:
      handle_symbol_code_at (text, location);
      break;
    }
}


/*-------------------------.
| Initialize the scanner.  |
`-------------------------*/

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


/*-----------------------------------------------.
| Free all the memory allocated to the scanner.  |
`-----------------------------------------------*/

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