/* (c) 1979 Regents of the University of California */ # include "ey.h" /* * * * * e y a c c * * * * */ /**** NB ----- * * This version of yacc, known as "eyacc" has been slightly but * importantly modified to allow error recovery in the UNIX Pascal * translator "pi" and also in "pix". * * Changes here include: * * 1) Enumeration of test actions when "error" is an input token. * * 2) Change to the encoding of the action entries. Test entries * are encoded as the arithmetic inverse of the symbol being tested * for. This is an optimization that makes the parser run at the * same speed even though, with error productions and enumerated * lookaheads, it would normally be much slower. Of course the * same thing could be done to the regular yacc... * * 3) Different table sizes * * 4) Recognizes form feeds * * 5) Also most of the numbers for the sizes of the tables have been * increased, to an extent to allow for "eyacc"ing of the Pascal grammar * and of a grammar which I have for "EUCLID". * * There seem to be subtle dependencies between the various magic * numbers... I found some of them but to be safe most of the limits * are very generous... for this reason "eyacc" will most likely * have to run separate i/d... no matter. * * Bill Joy * Computer Science Division * EECS Department * University of California, Berkeley * Berkeley, California 94704 * * Office: (415) 642-4948 * Home: (415) 524-4510 ****/ /* features to be fixed up ... *** Print estimate of total space needed for parser *** Either list inputs on y.output, or list empty prdn's in states *** Mention nonterms not used (or, rules. not reduced) as nonfatal error *** Output states where conflicts were found by default on y.output *** Engage in newspeak: production=>grammar rules, term=>token, etc. *** handle # define, #ifdef, etc., in yacc actions, %{ %} */ /* new features to be added *** reductions by single productions ( by request ) *** follow sets for start symbol *** option to only do slr(1) *** easily changed array names on output *** allocate core, rather than predefined *** input controlled by a grammar *** support multiple choices for conflicts *** better conflict diagnostics */ extern char *symnam(); main(argc,argv) int argc; char *argv[]; { auto int n; whereami(); setup(argc,argv); /* initialize and read productions */ tbitset = (nterms+16)/16; cpres(); /* make table of which productions yield a given nonterminal */ cempty(); /* make a table of which nonterminals can match the empty string */ cpfir(); /* make a table of e free first lists */ stagen(); /* generate the states */ output(); /* write the states and the tables */ go2out(); summary(); windup(); } whereami(){ /* sets the variable machine to UNIX, GCOS, or IBM */ int i; i = 1; i = i << 30; if( i == 0 ) { machine = UNIX; return; } i = i << 4; if( i == 0 ){ machine = IBM; return; } machine = GCOS; } windup(){ /* no errors, do the optimization if appropriate */ char *cp; int i; if( !oflag ) cexit(0); switch( machine ){ case GCOS: if( rflag ){ if( foutput<0 ) system( "./yopt -r" ); else system( "./yopt -rv" ); } else { if( foutput<0 ) system( "./yopt" ); else system( "./yopt -v" ); } cexit(0); /* terminate */ case UNIX: cp = "/usr/nlib/yaccopt"; if( rflag ) execl( cp, cp, (foutput<0)?"-r":"-rv", 0 ); else if( foutput<0 ) execl( cp, cp, 0 ); else execl( cp, cp, "-v", 0 ); error( "optimization execl call fails" ); case IBM: if( rflag ){ if( foutput<0 ) system( "MH2019.yaccopt -r" ); else system( "MH2019.yaccopt -rv" ); } else { if( foutput<0 ) system( "MH2019.yaccopt" ); else system( "MH2019.yaccopt -v" ); } cexit(0); } } settty() /* sets the output file to y.output */ { cflush( foutput ); /* a bit of a cheat */ cout = foutput; } settab(){ /* sets the output file to y.tab.c */ cflush( ftable ); cout = ftable; } char *chcopy( p, q ) char *p, *q; { /* copies string q into p, returning next free char ptr */ while( *p = *q++ ) ++p; return( p ); } char *writem(pp) struct item *pp; { /* creates output string for item pointed to by pp */ int i,*p; static char sarr[100]; char *q; for( p=pp->pitem; *p>0 ; ++p ) ; p = prdptr[-*p]; q = chcopy( sarr, nontrst[*p-NTBASE].name ); q = chcopy( q, " : " ); for(;;){ *q++ = ++p==(pp->pitem) ? '_' : ' '; if((i = *p) <= 0) break; q = chcopy( q, symnam(i) ); } *q = '\0' ; return( sarr ); } char *symnam(i){ /* return a pointer to the name of symbol i */ char *cp; cp = (i>=NTBASE) ? nontrst[i-NTBASE].name : trmset[i].name ; if( *cp == ' ' ) ++cp; return( cp ); } summary(){ /* output the summary on the tty */ int i, s, *pn; if( !rflag ){ settab(); fprintf( cout , "\nint nterms %d;",nterms); fprintf( cout , "\nint nnonter %d;", nnonter); fprintf( cout , "\nint nstate %d;", nstate); fprintf( cout , "\nchar *yysterm[] {"); for (i=1;i<=nterms;i++) if( trmset[i].value >= 0400 ) fprintf( cout , "\n\"%s\",",symnam(i)); fprintf( cout , "\n0 };\n" ); fprintf( cout , "\nchar *yysnter[] {"); for (i=0;i= memsiz) error("memory overflow"); return(omem); } aryfil( v, n, c ) int *v,n,c; { /* set elements 0 through n-1 to c */ int i; for( i=0; ilset; if( pp == 0 ) fprintf( cout , "\tNULL"); else { fprintf( cout , " { " ); for( j=1; j<=nterms; ++j ){ if( (pp[j>>4]>>(j&017) )&01 != 0 ) fprintf( cout , "%s ", symnam(j) ); } fprintf( cout , "}" ); } }