fatbase

parse.y (17941B)

---

 /*	$OpenBSD: parse.y,v 1.8 2003/06/04 17:34:44 millert Exp $	*/
 
 /* parse.y - parser for flex input */
 
 %token CHAR NUMBER SECTEND SCDECL XSCDECL NAME PREVCCL EOF_OP
 %token OPTION_OP OPT_OUTFILE OPT_PREFIX OPT_YYCLASS
 
 %token CCE_ALNUM CCE_ALPHA CCE_BLANK CCE_CNTRL CCE_DIGIT CCE_GRAPH
 %token CCE_LOWER CCE_PRINT CCE_PUNCT CCE_SPACE CCE_UPPER CCE_XDIGIT
 
 %{
 /*-
  * Copyright (c) 1990 The Regents of the University of California.
  * All rights reserved.
  *
  * This code is derived from software contributed to Berkeley by
  * Vern Paxson.
  * 
  * The United States Government has rights in this work pursuant
  * to contract no. DE-AC03-76SF00098 between the United States
  * Department of Energy and the University of California.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * Neither the name of the University nor the names of its contributors
  * may be used to endorse or promote products derived from this software
  * without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE.
  */
 
 /* $Header: /cvs/src/usr.bin/lex/parse.y,v 1.8 2003/06/04 17:34:44 millert Exp $ */
 
 
 /* Some versions of bison are broken in that they use alloca() but don't
  * declare it properly.  The following is the patented (just kidding!)
  * #ifdef chud to fix the problem, courtesy of Francois Pinard.
  */
 #ifdef YYBISON
 /* AIX requires this to be the first thing in the file.  What a piece.  */
 # ifdef _AIX
  #pragma alloca
 # endif
 #endif
 
 #include "flexdef.h"
 
 /* The remainder of the alloca() cruft has to come after including flexdef.h,
  * so HAVE_ALLOCA_H is (possibly) defined.
  */
 #ifdef YYBISON
 # ifdef __GNUC__
 #  ifndef alloca
 #   define alloca __builtin_alloca
 #  endif
 # else
 #  if HAVE_ALLOCA_H
 #   include <alloca.h>
 #  else
 #   ifdef __hpux
 void *alloca ();
 #   else
 #    ifdef __TURBOC__
 #     include <malloc.h>
 #    else
 char *alloca ();
 #    endif
 #   endif
 #  endif
 # endif
 #endif
 
 /* Bletch, ^^^^ that was ugly! */
 
 
 int pat, scnum, eps, headcnt, trailcnt, anyccl, lastchar, i, rulelen;
 int trlcontxt, xcluflg, currccl, cclsorted, varlength, variable_trail_rule;
 
 int *scon_stk;
 int scon_stk_ptr;
 
 static int madeany = false;  /* whether we've made the '.' character class */
 int previous_continued_action;	/* whether the previous rule's action was '|' */
 
 /* Expand a POSIX character class expression. */
 #define CCL_EXPR(func) \
 	{ \
 	int c; \
 	for ( c = 0; c < csize; ++c ) \
 		if ( isascii(c) && func(c) ) \
 			ccladd( currccl, c ); \
 	}
 
 /* While POSIX defines isblank(), it's not ANSI C. */
 #define IS_BLANK(c) ((c) == ' ' || (c) == '\t')
 
 /* On some over-ambitious machines, such as DEC Alpha's, the default
  * token type is "long" instead of "int"; this leads to problems with
  * declaring yylval in flexdef.h.  But so far, all the yacc's I've seen
  * wrap their definitions of YYSTYPE with "#ifndef YYSTYPE"'s, so the
  * following should ensure that the default token type is "int".
  */
 #define YYSTYPE int
 
 %}
 
 %%
 goal		:  initlex sect1 sect1end sect2 initforrule
 			{ /* add default rule */
 			int def_rule;
 
 			pat = cclinit();
 			cclnegate( pat );
 
 			def_rule = mkstate( -pat );
 
 			/* Remember the number of the default rule so we
 			 * don't generate "can't match" warnings for it.
 			 */
 			default_rule = num_rules;
 
 			finish_rule( def_rule, false, 0, 0 );
 
 			for ( i = 1; i <= lastsc; ++i )
 				scset[i] = mkbranch( scset[i], def_rule );
 
 			if ( spprdflt )
 				add_action(
 				"YY_FATAL_ERROR( \"flex scanner jammed\" )" );
 			else
 				add_action( "ECHO" );
 
 			add_action( ";\n\tYY_BREAK\n" );
 			}
 		;
 
 initlex		:
 			{ /* initialize for processing rules */
 
 			/* Create default DFA start condition. */
 			scinstal( "INITIAL", false );
 			}
 		;
 
 sect1		:  sect1 startconddecl namelist1
 		|  sect1 options
 		|
 		|  error
 			{ synerr( "unknown error processing section 1" ); }
 		;
 
 sect1end	:  SECTEND
 			{
 			check_options();
 			scon_stk = allocate_integer_array( lastsc + 1 );
 			scon_stk_ptr = 0;
 			}
 		;
 
 startconddecl	:  SCDECL
 			{ xcluflg = false; }
 
 		|  XSCDECL
 			{ xcluflg = true; }
 		;
 
 namelist1	:  namelist1 NAME
 			{ scinstal( nmstr, xcluflg ); }
 
 		|  NAME
 			{ scinstal( nmstr, xcluflg ); }
 
 		|  error
 			{ synerr( "bad start condition list" ); }
 		;
 
 options		:  OPTION_OP optionlist
 		;
 
 optionlist	:  optionlist option
 		|
 		;
 
 option		:  OPT_OUTFILE '=' NAME
 			{
 			outfilename = copy_string( nmstr );
 			did_outfilename = 1;
 			}
 		|  OPT_PREFIX '=' NAME
 			{ prefix = copy_string( nmstr ); }
 		|  OPT_YYCLASS '=' NAME
 			{ yyclass = copy_string( nmstr ); }
 		;
 
 sect2		:  sect2 scon initforrule flexrule '\n'
 			{ scon_stk_ptr = $2; }
 		|  sect2 scon '{' sect2 '}'
 			{ scon_stk_ptr = $2; }
 		|
 		;
 
 initforrule	:
 			{
 			/* Initialize for a parse of one rule. */
 			trlcontxt = variable_trail_rule = varlength = false;
 			trailcnt = headcnt = rulelen = 0;
 			current_state_type = STATE_NORMAL;
 			previous_continued_action = continued_action;
 			in_rule = true;
 
 			new_rule();
 			}
 		;
 
 flexrule	:  '^' rule
 			{
 			pat = $2;
 			finish_rule( pat, variable_trail_rule,
 				headcnt, trailcnt );
 
 			if ( scon_stk_ptr > 0 )
 				{
 				for ( i = 1; i <= scon_stk_ptr; ++i )
 					scbol[scon_stk[i]] =
 						mkbranch( scbol[scon_stk[i]],
 								pat );
 				}
 
 			else
 				{
 				/* Add to all non-exclusive start conditions,
 				 * including the default (0) start condition.
 				 */
 
 				for ( i = 1; i <= lastsc; ++i )
 					if ( ! scxclu[i] )
 						scbol[i] = mkbranch( scbol[i],
 									pat );
 				}
 
 			if ( ! bol_needed )
 				{
 				bol_needed = true;
 
 				if ( performance_report > 1 )
 					pinpoint_message(
 			"'^' operator results in sub-optimal performance" );
 				}
 			}
 
 		|  rule
 			{
 			pat = $1;
 			finish_rule( pat, variable_trail_rule,
 				headcnt, trailcnt );
 
 			if ( scon_stk_ptr > 0 )
 				{
 				for ( i = 1; i <= scon_stk_ptr; ++i )
 					scset[scon_stk[i]] =
 						mkbranch( scset[scon_stk[i]],
 								pat );
 				}
 
 			else
 				{
 				for ( i = 1; i <= lastsc; ++i )
 					if ( ! scxclu[i] )
 						scset[i] =
 							mkbranch( scset[i],
 								pat );
 				}
 			}
 
 		|  EOF_OP
 			{
 			if ( scon_stk_ptr > 0 )
 				build_eof_action();
 	
 			else
 				{
 				/* This EOF applies to all start conditions
 				 * which don't already have EOF actions.
 				 */
 				for ( i = 1; i <= lastsc; ++i )
 					if ( ! sceof[i] )
 						scon_stk[++scon_stk_ptr] = i;
 
 				if ( scon_stk_ptr == 0 )
 					warn(
 			"all start conditions already have <<EOF>> rules" );
 
 				else
 					build_eof_action();
 				}
 			}
 
 		|  error
 			{ synerr( "unrecognized rule" ); }
 		;
 
 scon_stk_ptr	:
 			{ $$ = scon_stk_ptr; }
 		;
 
 scon		:  '<' scon_stk_ptr namelist2 '>'
 			{ $$ = $2; }
 
 		|  '<' '*' '>'
 			{
 			$$ = scon_stk_ptr;
 
 			for ( i = 1; i <= lastsc; ++i )
 				{
 				int j;
 
 				for ( j = 1; j <= scon_stk_ptr; ++j )
 					if ( scon_stk[j] == i )
 						break;
 
 				if ( j > scon_stk_ptr )
 					scon_stk[++scon_stk_ptr] = i;
 				}
 			}
 
 		|
 			{ $$ = scon_stk_ptr; }
 		;
 
 namelist2	:  namelist2 ',' sconname
 
 		|  sconname
 
 		|  error
 			{ synerr( "bad start condition list" ); }
 		;
 
 sconname	:  NAME
 			{
 			if ( (scnum = sclookup( nmstr )) == 0 )
 				format_pinpoint_message(
 					"undeclared start condition %s",
 					nmstr );
 			else
 				{
 				for ( i = 1; i <= scon_stk_ptr; ++i )
 					if ( scon_stk[i] == scnum )
 						{
 						format_warn(
 							"<%s> specified twice",
 							scname[scnum] );
 						break;
 						}
 
 				if ( i > scon_stk_ptr )
 					scon_stk[++scon_stk_ptr] = scnum;
 				}
 			}
 		;
 
 rule		:  re2 re
 			{
 			if ( transchar[lastst[$2]] != SYM_EPSILON )
 				/* Provide final transition \now/ so it
 				 * will be marked as a trailing context
 				 * state.
 				 */
 				$2 = link_machines( $2,
 						mkstate( SYM_EPSILON ) );
 
 			mark_beginning_as_normal( $2 );
 			current_state_type = STATE_NORMAL;
 
 			if ( previous_continued_action )
 				{
 				/* We need to treat this as variable trailing
 				 * context so that the backup does not happen
 				 * in the action but before the action switch
 				 * statement.  If the backup happens in the
 				 * action, then the rules "falling into" this
 				 * one's action will *also* do the backup,
 				 * erroneously.
 				 */
 				if ( ! varlength || headcnt != 0 )
 					warn(
 		"trailing context made variable due to preceding '|' action" );
 
 				/* Mark as variable. */
 				varlength = true;
 				headcnt = 0;
 				}
 
 			if ( lex_compat || (varlength && headcnt == 0) )
 				{ /* variable trailing context rule */
 				/* Mark the first part of the rule as the
 				 * accepting "head" part of a trailing
 				 * context rule.
 				 *
 				 * By the way, we didn't do this at the
 				 * beginning of this production because back
 				 * then current_state_type was set up for a
 				 * trail rule, and add_accept() can create
 				 * a new state ...
 				 */
 				add_accept( $1,
 					num_rules | YY_TRAILING_HEAD_MASK );
 				variable_trail_rule = true;
 				}
 			
 			else
 				trailcnt = rulelen;
 
 			$$ = link_machines( $1, $2 );
 			}
 
 		|  re2 re '$'
 			{ synerr( "trailing context used twice" ); }
 
 		|  re '$'
 			{
 			headcnt = 0;
 			trailcnt = 1;
 			rulelen = 1;
 			varlength = false;
 
 			current_state_type = STATE_TRAILING_CONTEXT;
 
 			if ( trlcontxt )
 				{
 				synerr( "trailing context used twice" );
 				$$ = mkstate( SYM_EPSILON );
 				}
 
 			else if ( previous_continued_action )
 				{
 				/* See the comment in the rule for "re2 re"
 				 * above.
 				 */
 				warn(
 		"trailing context made variable due to preceding '|' action" );
 
 				varlength = true;
 				}
 
 			if ( lex_compat || varlength )
 				{
 				/* Again, see the comment in the rule for
 				 * "re2 re" above.
 				 */
 				add_accept( $1,
 					num_rules | YY_TRAILING_HEAD_MASK );
 				variable_trail_rule = true;
 				}
 
 			trlcontxt = true;
 
 			eps = mkstate( SYM_EPSILON );
 			$$ = link_machines( $1,
 				link_machines( eps, mkstate( '\n' ) ) );
 			}
 
 		|  re
 			{
 			$$ = $1;
 
 			if ( trlcontxt )
 				{
 				if ( lex_compat || (varlength && headcnt == 0) )
 					/* Both head and trail are
 					 * variable-length.
 					 */
 					variable_trail_rule = true;
 				else
 					trailcnt = rulelen;
 				}
 			}
 		;
 
 
 re		:  re '|' series
 			{
 			varlength = true;
 			$$ = mkor( $1, $3 );
 			}
 
 		|  series
 			{ $$ = $1; }
 		;
 
 
 re2		:  re '/'
 			{
 			/* This rule is written separately so the
 			 * reduction will occur before the trailing
 			 * series is parsed.
 			 */
 
 			if ( trlcontxt )
 				synerr( "trailing context used twice" );
 			else
 				trlcontxt = true;
 
 			if ( varlength )
 				/* We hope the trailing context is
 				 * fixed-length.
 				 */
 				varlength = false;
 			else
 				headcnt = rulelen;
 
 			rulelen = 0;
 
 			current_state_type = STATE_TRAILING_CONTEXT;
 			$$ = $1;
 			}
 		;
 
 series		:  series singleton
 			{
 			/* This is where concatenation of adjacent patterns
 			 * gets done.
 			 */
 			$$ = link_machines( $1, $2 );
 			}
 
 		|  singleton
 			{ $$ = $1; }
 		;
 
 singleton	:  singleton '*'
 			{
 			varlength = true;
 
 			$$ = mkclos( $1 );
 			}
 
 		|  singleton '+'
 			{
 			varlength = true;
 			$$ = mkposcl( $1 );
 			}
 
 		|  singleton '?'
 			{
 			varlength = true;
 			$$ = mkopt( $1 );
 			}
 
 		|  singleton '{' NUMBER ',' NUMBER '}'
 			{
 			varlength = true;
 
 			if ( $3 > $5 || $3 < 0 )
 				{
 				synerr( "bad iteration values" );
 				$$ = $1;
 				}
 			else
 				{
 				if ( $3 == 0 )
 					{
 					if ( $5 <= 0 )
 						{
 						synerr(
 						"bad iteration values" );
 						$$ = $1;
 						}
 					else
 						$$ = mkopt(
 							mkrep( $1, 1, $5 ) );
 					}
 				else
 					$$ = mkrep( $1, $3, $5 );
 				}
 			}
 
 		|  singleton '{' NUMBER ',' '}'
 			{
 			varlength = true;
 
 			if ( $3 <= 0 )
 				{
 				synerr( "iteration value must be positive" );
 				$$ = $1;
 				}
 
 			else
 				$$ = mkrep( $1, $3, INFINITY );
 			}
 
 		|  singleton '{' NUMBER '}'
 			{
 			/* The singleton could be something like "(foo)",
 			 * in which case we have no idea what its length
 			 * is, so we punt here.
 			 */
 			varlength = true;
 
 			if ( $3 <= 0 )
 				{
 				synerr( "iteration value must be positive" );
 				$$ = $1;
 				}
 
 			else
 				$$ = link_machines( $1,
 						copysingl( $1, $3 - 1 ) );
 			}
 
 		|  '.'
 			{
 			if ( ! madeany )
 				{
 				/* Create the '.' character class. */
 				anyccl = cclinit();
 				ccladd( anyccl, '\n' );
 				cclnegate( anyccl );
 
 				if ( useecs )
 					mkeccl( ccltbl + cclmap[anyccl],
 						ccllen[anyccl], nextecm,
 						ecgroup, csize, csize );
 
 				madeany = true;
 				}
 
 			++rulelen;
 
 			$$ = mkstate( -anyccl );
 			}
 
 		|  fullccl
 			{
 			if ( ! cclsorted )
 				/* Sort characters for fast searching.  We
 				 * use a shell sort since this list could
 				 * be large.
 				 */
 				cshell( ccltbl + cclmap[$1], ccllen[$1], true );
 
 			if ( useecs )
 				mkeccl( ccltbl + cclmap[$1], ccllen[$1],
 					nextecm, ecgroup, csize, csize );
 
 			++rulelen;
 
 			$$ = mkstate( -$1 );
 			}
 
 		|  PREVCCL
 			{
 			++rulelen;
 
 			$$ = mkstate( -$1 );
 			}
 
 		|  '"' string '"'
 			{ $$ = $2; }
 
 		|  '(' re ')'
 			{ $$ = $2; }
 
 		|  CHAR
 			{
 			++rulelen;
 
 			if ( caseins && $1 >= 'A' && $1 <= 'Z' )
 				$1 = clower( $1 );
 
 			$$ = mkstate( $1 );
 			}
 		;
 
 fullccl		:  '[' ccl ']'
 			{ $$ = $2; }
 
 		|  '[' '^' ccl ']'
 			{
 			cclnegate( $3 );
 			$$ = $3;
 			}
 		;
 
 ccl		:  ccl CHAR '-' CHAR
 			{
 			if ( caseins )
 				{
 				if ( $2 >= 'A' && $2 <= 'Z' )
 					$2 = clower( $2 );
 				if ( $4 >= 'A' && $4 <= 'Z' )
 					$4 = clower( $4 );
 				}
 
 			if ( $2 > $4 )
 				synerr( "negative range in character class" );
 
 			else
 				{
 				for ( i = $2; i <= $4; ++i )
 					ccladd( $1, i );
 
 				/* Keep track if this ccl is staying in
 				 * alphabetical order.
 				 */
 				cclsorted = cclsorted && ($2 > lastchar);
 				lastchar = $4;
 				}
 
 			$$ = $1;
 			}
 
 		|  ccl CHAR
 			{
 			if ( caseins && $2 >= 'A' && $2 <= 'Z' )
 				$2 = clower( $2 );
 
 			ccladd( $1, $2 );
 			cclsorted = cclsorted && ($2 > lastchar);
 			lastchar = $2;
 			$$ = $1;
 			}
 
 		|  ccl ccl_expr
 			{
 			/* Too hard to properly maintain cclsorted. */
 			cclsorted = false;
 			$$ = $1;
 			}
 
 		|
 			{
 			cclsorted = true;
 			lastchar = 0;
 			currccl = $$ = cclinit();
 			}
 		;
 
 ccl_expr:	   CCE_ALNUM	{ CCL_EXPR(isalnum) }
 		|  CCE_ALPHA	{ CCL_EXPR(isalpha) }
 		|  CCE_BLANK	{ CCL_EXPR(IS_BLANK) }
 		|  CCE_CNTRL	{ CCL_EXPR(iscntrl) }
 		|  CCE_DIGIT	{ CCL_EXPR(isdigit) }
 		|  CCE_GRAPH	{ CCL_EXPR(isgraph) }
 		|  CCE_LOWER	{ CCL_EXPR(islower) }
 		|  CCE_PRINT	{ CCL_EXPR(isprint) }
 		|  CCE_PUNCT	{ CCL_EXPR(ispunct) }
 		|  CCE_SPACE	{ CCL_EXPR(isspace) }
 		|  CCE_UPPER	{
 				if ( caseins )
 					CCL_EXPR(islower)
 				else
 					CCL_EXPR(isupper)
 				}
 		|  CCE_XDIGIT	{ CCL_EXPR(isxdigit) }
 		;
 		
 string		:  string CHAR
 			{
 			if ( caseins && $2 >= 'A' && $2 <= 'Z' )
 				$2 = clower( $2 );
 
 			++rulelen;
 
 			$$ = link_machines( $1, mkstate( $2 ) );
 			}
 
 		|
 			{ $$ = mkstate( SYM_EPSILON ); }
 		;
 
 %%
 
 
 /* build_eof_action - build the "<<EOF>>" action for the active start
  *                    conditions
  */
 
 void build_eof_action()
 	{
 	register int i;
 	char action_text[MAXLINE];
 
 	for ( i = 1; i <= scon_stk_ptr; ++i )
 		{
 		if ( sceof[scon_stk[i]] )
 			format_pinpoint_message(
 				"multiple <<EOF>> rules for start condition %s",
 				scname[scon_stk[i]] );
 
 		else
 			{
 			sceof[scon_stk[i]] = true;
 			snprintf( action_text, sizeof action_text,
 				"case YY_STATE_EOF(%s):\n",
 				scname[scon_stk[i]] );
 			add_action( action_text );
 			}
 		}
 
 	line_directive_out( (FILE *) 0, 1 );
 
 	/* This isn't a normal rule after all - don't count it as
 	 * such, so we don't have any holes in the rule numbering
 	 * (which make generating "rule can never match" warnings
 	 * more difficult.
 	 */
 	--num_rules;
 	++num_eof_rules;
 	}
 
 
 /* format_synerr - write out formatted syntax error */
 
 void format_synerr( msg, arg )
 char msg[], arg[];
 	{
 	char errmsg[MAXLINE];
 
 	(void) snprintf( errmsg, sizeof errmsg, msg, arg );
 	synerr( errmsg );
 	}
 
 
 /* synerr - report a syntax error */
 
 void synerr( str )
 char str[];
 	{
 	syntaxerror = true;
 	pinpoint_message( str );
 	}
 
 
 /* format_warn - write out formatted warning */
 
 void format_warn( msg, arg )
 char msg[], arg[];
 	{
 	char warn_msg[MAXLINE];
 
 	(void) snprintf( warn_msg, sizeof warn_msg, msg, arg );
 	warn( warn_msg );
 	}
 
 
 /* warn - report a warning, unless -w was given */
 
 void warn( str )
 char str[];
 	{
 	line_warning( str, linenum );
 	}
 
 /* format_pinpoint_message - write out a message formatted with one string,
  *			     pinpointing its location
  */
 
 void format_pinpoint_message( msg, arg )
 char msg[], arg[];
 	{
 	char errmsg[MAXLINE];
 
 	(void) snprintf( errmsg, sizeof errmsg, msg, arg );
 	pinpoint_message( errmsg );
 	}
 
 
 /* pinpoint_message - write out a message, pinpointing its location */
 
 void pinpoint_message( str )
 char str[];
 	{
 	line_pinpoint( str, linenum );
 	}
 
 
 /* line_warning - report a warning at a given line, unless -w was given */
 
 void line_warning( str, line )
 char str[];
 int line;
 	{
 	char warning[MAXLINE];
 
 	if ( ! nowarn )
 		{
 		snprintf( warning, sizeof warning, "warning, %s", str );
 		line_pinpoint( warning, line );
 		}
 	}
 
 
 /* line_pinpoint - write out a message, pinpointing it at the given line */
 
 void line_pinpoint( str, line )
 char str[];
 int line;
 	{
 	fprintf( stderr, "\"%s\", line %d: %s\n", infilename, line, str );
 	}
 
 
 /* yyerror - eat up an error message from the parser;
  *	     currently, messages are ignore
  */
 
 void yyerror( msg )
 char msg[];
 	{
 	}