/* parse.y - parser for flex input */ %token CHAR NUMBER SECTEND SCDECL XSCDECL WHITESPACE NAME PREVCCL EOF_OP %{ /*- * 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 are permitted provided * that: (1) source distributions retain this entire copyright notice and * comment, and (2) distributions including binaries display the following * acknowledgement: ``This product includes software developed by the * University of California, Berkeley and its contributors'' in the * documentation or other materials provided with the distribution and in * all advertising materials mentioning features or use of this software. * 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. */ #ifndef lint static char rcsid[] = "@(#) $Id$ (LBL)"; #endif #include "flexdef.h" int pat, scnum, eps, headcnt, trailcnt, anyccl, lastchar, i, actvp, rulelen; int trlcontxt, xcluflg, cclsorted, varlength, variable_trail_rule; Char clower(); static int madeany = false; /* whether we've made the '.' character class */ int previous_continued_action; /* whether the previous rule's action was '|' */ %} %% goal : initlex sect1 sect1end sect2 initforrule { /* add default rule */ int def_rule; pat = cclinit(); cclnegate( pat ); def_rule = mkstate( -pat ); finish_rule( def_rule, false, 0, 0 ); for ( i = 1; i <= lastsc; ++i ) scset[i] = mkbranch( scset[i], def_rule ); if ( spprdflt ) fputs( "YY_FATAL_ERROR( \"flex scanner jammed\" )", temp_action_file ); else fputs( "ECHO", temp_action_file ); fputs( ";\n\tYY_BREAK\n", temp_action_file ); } ; initlex : { /* initialize for processing rules */ /* create default DFA start condition */ scinstal( "INITIAL", false ); } ; sect1 : sect1 startconddecl WHITESPACE namelist1 '\n' | | error '\n' { synerr( "unknown error processing section 1" ); } ; sect1end : SECTEND ; startconddecl : SCDECL { /* these productions are separate from the s1object * rule because the semantics must be done before * we parse the remainder of an s1object */ xcluflg = false; } | XSCDECL { xcluflg = true; } ; namelist1 : namelist1 WHITESPACE NAME { scinstal( nmstr, xcluflg ); } | NAME { scinstal( nmstr, xcluflg ); } | error { synerr( "bad start condition list" ); } ; sect2 : sect2 initforrule flexrule '\n' | ; 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; new_rule(); } ; flexrule : scon '^' rule { pat = $3; finish_rule( pat, variable_trail_rule, headcnt, trailcnt ); for ( i = 1; i <= actvp; ++i ) scbol[actvsc[i]] = mkbranch( scbol[actvsc[i]], pat ); if ( ! bol_needed ) { bol_needed = true; if ( performance_report ) pinpoint_message( "'^' operator results in sub-optimal performance" ); } } | scon rule { pat = $2; finish_rule( pat, variable_trail_rule, headcnt, trailcnt ); for ( i = 1; i <= actvp; ++i ) scset[actvsc[i]] = mkbranch( scset[actvsc[i]], pat ); } | '^' rule { pat = $2; finish_rule( pat, variable_trail_rule, headcnt, trailcnt ); /* 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 ) pinpoint_message( "'^' operator results in sub-optimal performance" ); } } | rule { pat = $1; finish_rule( pat, variable_trail_rule, headcnt, trailcnt ); for ( i = 1; i <= lastsc; ++i ) if ( ! scxclu[i] ) scset[i] = mkbranch( scset[i], pat ); } | scon EOF_OP { build_eof_action(); } | EOF_OP { /* this EOF applies to all start conditions * which don't already have EOF actions */ actvp = 0; for ( i = 1; i <= lastsc; ++i ) if ( ! sceof[i] ) actvsc[++actvp] = i; if ( actvp == 0 ) pinpoint_message( "warning - all start conditions already have <> rules" ); else build_eof_action(); } | error { synerr( "unrecognized rule" ); } ; scon : '<' namelist2 '>' ; namelist2 : namelist2 ',' NAME { if ( (scnum = sclookup( nmstr )) == 0 ) format_pinpoint_message( "undeclared start condition %s", nmstr ); else actvsc[++actvp] = scnum; } | NAME { if ( (scnum = sclookup( nmstr )) == 0 ) format_pinpoint_message( "undeclared start condition %s", nmstr ); else actvsc[actvp = 1] = scnum; } | error { synerr( "bad start condition list" ); } ; 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 ) { fprintf( stderr, "%s: warning - trailing context rule at line %d made variable because\n", program_name, linenum ); fprintf( stderr, " of preceding '|' action\n" ); } /* mark as variable */ varlength = true; headcnt = 0; } if ( 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; $$ = link_machines( $1, $2 ); } | re2 re '$' { synerr( "trailing context used twice" ); } | re '$' { if ( trlcontxt ) { synerr( "trailing context used twice" ); $$ = mkstate( SYM_EPSILON ); } else if ( previous_continued_action ) { /* see the comment in the rule for "re2 re" * above */ if ( ! varlength || headcnt != 0 ) { fprintf( stderr, "%s: warning - trailing context rule at line %d made variable because\n", program_name, linenum ); fprintf( stderr, " of preceding '|' action\n" ); } /* mark as variable */ varlength = true; headcnt = 0; } trlcontxt = true; if ( ! varlength ) headcnt = rulelen; ++rulelen; trailcnt = 1; eps = mkstate( SYM_EPSILON ); $$ = link_machines( $1, link_machines( eps, mkstate( '\n' ) ) ); } | re { $$ = $1; if ( trlcontxt ) { if ( 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" ); $$ = $1; } else { if ( $3 == 0 ) $$ = mkopt( mkrep( $1, $3, $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 ']' { /* *Sigh* - to be compatible Unix lex, negated ccls * match newlines */ #ifdef NOTDEF ccladd( $3, '\n' ); /* negated ccls don't match '\n' */ cclsorted = false; /* because we added the newline */ #endif cclnegate( $3 ); $$ = $3; } ; ccl : ccl CHAR '-' CHAR { if ( $2 > $4 ) synerr( "negative range in character class" ); else { if ( caseins ) { if ( $2 >= 'A' && $2 <= 'Z' ) $2 = clower( $2 ); if ( $4 >= 'A' && $4 <= 'Z' ) $4 = clower( $4 ); } for ( i = $2; i <= $4; ++i ) ccladd( $1, i ); /* keep track if this ccl is staying in alphabetical * order */ cclsorted = cclsorted && ($2 > lastchar); lastchar = $4; } $$ = $1; } | ccl CHAR { if ( caseins ) if ( $2 >= 'A' && $2 <= 'Z' ) $2 = clower( $2 ); ccladd( $1, $2 ); cclsorted = cclsorted && ($2 > lastchar); lastchar = $2; $$ = $1; } | { cclsorted = true; lastchar = 0; $$ = cclinit(); } ; string : string CHAR { if ( caseins ) if ( $2 >= 'A' && $2 <= 'Z' ) $2 = clower( $2 ); ++rulelen; $$ = link_machines( $1, mkstate( $2 ) ); } | { $$ = mkstate( SYM_EPSILON ); } ; %% /* build_eof_action - build the "<>" action for the active start * conditions */ void build_eof_action() { register int i; for ( i = 1; i <= actvp; ++i ) { if ( sceof[actvsc[i]] ) format_pinpoint_message( "multiple <> rules for start condition %s", scname[actvsc[i]] ); else { sceof[actvsc[i]] = true; fprintf( temp_action_file, "case YY_STATE_EOF(%s):\n", scname[actvsc[i]] ); } } line_directive_out( temp_action_file ); } /* synerr - report a syntax error */ void synerr( str ) char str[]; { syntaxerror = true; pinpoint_message( str ); } /* 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) sprintf( errmsg, msg, arg ); pinpoint_message( errmsg ); } /* pinpoint_message - write out a message, pinpointing its location */ void pinpoint_message( str ) char str[]; { fprintf( stderr, "\"%s\", line %d: %s\n", infilename, linenum, str ); } /* yyerror - eat up an error message from the parser; * currently, messages are ignore */ void yyerror( msg ) char msg[]; { }