1BSD/eyacc/ey1.c
# 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
*/
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;
cflush(1);
if( !oflag ) cexit(0);
for( i=3; i<10; ++i ) cclose(i);
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();
printf("\nint nterms %d;",nterms);
printf("\nint nnonter %d;", nnonter);
printf("\nint nstate %d;", nstate);
printf("\nchar *yysterm[] {");
for (i=1;i<=nterms;i++) if( trmset[i].value >= 0400 ) printf("\n\"%s\",",symnam(i));
printf( "\n0 };\n" );
printf("\nchar *yysnter[] {");
for (i=0;i<nnonter;i++) printf("\n\"%s\",",nontrst[i].name);
printf("\n\"%s\" };\n",nontrst[nnonter].name);
}
settty();
printf("\n%d/%d terminals, %d/%d nonterminals\n", nterms, tlim,
nnonter, ntlim );
printf("%d/%d grammar rules, %d/%d states\n", nprod, prdlim, nstate, stsize );
printf("%d shift/reduce, %d reduce/reduce conflicts reported\n", zzsrconf, zzrrconf );
pn = pstate[nstate+1];
printf("%d/%d working sets used\n", zzcwset, wssize );
printf("memory: states,etc. %d/%d, parser %d/%d\n", pn-mem0, memsiz,
memact, actsiz );
printf("%d/%d distinct lookahead sets\n", nlset, lsetsz );
printf("%d extra closures\n", zzclose - 2*nstate );
printf("%d action entries\n", zzacent );
printf("%d action entries saved through merging %d states\n",zzacsave,zznsave);
printf("%d goto entries\n", zzgoent );
printf("%d entries saved by goto default\n", zzgobest );
if( zzsrconf!=0 || zzrrconf!=0 ){
cflush( errfileno );
cout = errfileno;
printf("\nconflicts: ");
if( zzsrconf )printf( "%d shift/reduce" , zzsrconf );
if( zzsrconf && zzrrconf )printf( ", " );
if( zzrrconf )printf( "%d reduce/reduce" , zzrrconf );
printf( "\n" );
}
}
error(s,a1){ /* write out error comment */
int c;
++nerrors;
cflush( errfileno );
cout = errfileno; /* set output to tty */
printf("\n fatal error: ");
printf(s,a1);
printf(", line %d\n", lineno );
if( !fatfl ) return;
summary();
cexit(1);
}
arrset(s) char s[]; {
printf("\nint %s[] {0", s );
arrndx = 1;
}
arrval(n){
printf(",%d",n);
if( (++arrndx%10) == 0 ) printf("\n");
}
arrdone(){
printf(",-1};\n");
}
copy(v) char *v; { /* copy ctokn to v */
char *p;
p=ctokn;
while( *v++ = *p++ );
}
compare(v) char *v; { /* compare ctokn with v */
char *p;
for( p=ctokn; ; ++p ){
if( *p != *v++ ) return( 0 );
if( *p == 0 ) return(1);
}
}
int *yalloc(n){ /* allocate n+1 words from vector mem */
int *omem;
omem = mem;
mem =+ n+1;
if(mem-mem0 >= 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; i<n; ++i ) v[i] = c;
}
union( a, b, c ) int *a, *b, *c; {
/* set a to the union of b and c */
/* a may equal b */
/* return 1 if c is not a subset of b, 0 otherwise */
_REGISTER int i, x, sub;
sub = 0;
for( i=0; i<tbitset; ++i ){
x = b[i] | c[i];
if( x != b[i] ) sub=1;
a[i] = x;
}
return( sub );
}
prlook( pp ) int *pp;{
int j;
pp = pp->lset;
if( pp == 0 ) printf("\tNULL");
else {
printf(" { " );
for( j=1; j<=nterms; ++j ){
if( (pp[j>>4]>>(j&017) )&01 != 0 ) printf( "%s ", symnam(j) );
}
printf( "}" );
}
}