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About 0.5KiB of additional compression in the parser tables. (CVS 2764)

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FossilOrigin-Name: f39974ebd81f274dc4cf6cf94e6e87ee7b4a0814
This commit is contained in:
drh
2005-11-06 04:06:59 +00:00
parent 152410fade
commit fd405314d3
4 changed files with 153 additions and 76 deletions
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145
tool/lemon.c
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@ -120,7 +120,8 @@ struct symbol {
int index; /* Index number for this symbol */
enum {
TERMINAL,
NONTERMINAL
NONTERMINAL,
MULTITERMINAL
} type; /* Symbols are all either TERMINALS or NTs */
struct rule *rule; /* Linked list of rules of this (if an NT) */
struct symbol *fallback; /* fallback token in case this token doesn't parse */
@ -141,6 +142,9 @@ struct symbol {
int dtnum; /* The data type number. In the parser, the value
** stack is a union. The .yy%d element of this
** union is the correct data type for this object */
/* The following fields are used by MULTITERMINALs only */
int nsubsym; /* Number of constituent symbols in the MULTI */
struct symbol **subsym; /* Array of constituent symbols */
};
/* Each production rule in the grammar is stored in the following
@ -585,11 +589,18 @@ struct lemon *xp;
struct rule *rp;
for(rp=xp->rule; rp; rp=rp->next){
if( rp->precsym==0 ){
int i;
for(i=0; i<rp->nrhs; i++){
if( rp->rhs[i]->prec>=0 ){
int i, j;
for(i=0; i<rp->nrhs && rp->precsym==0; i++){
struct symbol *sp = rp->rhs[i];
if( sp->type==MULTITERMINAL ){
for(j=0; j<sp->nsubsym; j++){
if( sp->subsym[j]->prec>=0 ){
rp->precsym = sp->subsym[j];
break;
}
}
}else if( sp->prec>=0 ){
rp->precsym = rp->rhs[i];
break;
}
}
}
@ -605,7 +616,7 @@ struct lemon *xp;
void FindFirstSets(lemp)
struct lemon *lemp;
{
int i;
int i, j;
struct rule *rp;
int progress;
@ -622,7 +633,8 @@ struct lemon *lemp;
for(rp=lemp->rule; rp; rp=rp->next){
if( rp->lhs->lambda ) continue;
for(i=0; i<rp->nrhs; i++){
if( rp->rhs[i]->lambda==B_FALSE ) break;
struct symbol *sp = rp->rhs[i];
if( sp->type!=TERMINAL || sp->lambda==B_FALSE ) break;
}
if( i==rp->nrhs ){
rp->lhs->lambda = B_TRUE;
@ -642,6 +654,11 @@ struct lemon *lemp;
if( s2->type==TERMINAL ){
progress += SetAdd(s1->firstset,s2->index);
break;
}else if( s2->type==MULTITERMINAL ){
for(j=0; j<s2->nsubsym; j++){
progress += SetAdd(s1->firstset,s2->subsym[j]->index);
}
break;
}else if( s1==s2 ){
if( s1->lambda==B_FALSE ) break;
}else{
@ -688,7 +705,7 @@ symbol instead.",lemp->start,lemp->rule->lhs->name);
for(rp=lemp->rule; rp; rp=rp->next){
int i;
for(i=0; i<rp->nrhs; i++){
if( rp->rhs[i]==sp ){
if( rp->rhs[i]==sp ){ /* FIX ME: Deal with multiterminals */
ErrorMsg(lemp->filename,0,
"The start symbol \"%s\" occurs on the \
right-hand side of a rule. This will result in a parser which \
@ -760,6 +777,24 @@ struct lemon *lemp;
return stp;
}
/*
** Return true if two symbols are the same.
*/
int same_symbol(a,b)
struct symbol *a;
struct symbol *b;
{
int i;
if( a==b ) return 1;
if( a->type!=MULTITERMINAL ) return 0;
if( b->type!=MULTITERMINAL ) return 0;
if( a->nsubsym!=b->nsubsym ) return 0;
for(i=0; i<a->nsubsym; i++){
if( a->subsym[i]!=b->subsym[i] ) return 0;
}
return 1;
}
/* Construct all successor states to the given state. A "successor"
** state is any state which can be reached by a shift action.
*/
@ -792,7 +827,7 @@ struct state *stp; /* The state from which successors are computed */
if( bcfp->status==COMPLETE ) continue; /* Already used */
if( bcfp->dot>=bcfp->rp->nrhs ) continue; /* Can't shift this one */
bsp = bcfp->rp->rhs[bcfp->dot]; /* Get symbol after dot */
if( bsp!=sp ) continue; /* Must be same as for "cfp" */
if( !same_symbol(bsp,sp) ) continue; /* Must be same as for "cfp" */
bcfp->status = COMPLETE; /* Mark this config as used */
new = Configlist_addbasis(bcfp->rp,bcfp->dot+1);
Plink_add(&new->bplp,bcfp);
@ -804,7 +839,14 @@ struct state *stp; /* The state from which successors are computed */
/* The state "newstp" is reached from the state "stp" by a shift action
** on the symbol "sp" */
Action_add(&stp->ap,SHIFT,sp,(char *)newstp);
if( sp->type==MULTITERMINAL ){
int i;
for(i=0; i<sp->nsubsym; i++){
Action_add(&stp->ap,SHIFT,sp->subsym[i],(char*)newstp);
}
}else{
Action_add(&stp->ap,SHIFT,sp,(char *)newstp);
}
}
}
@ -1167,6 +1209,12 @@ struct lemon *lemp;
if( xsp->type==TERMINAL ){
SetAdd(newcfp->fws,xsp->index);
break;
}else if( xsp->type==MULTITERMINAL ){
int k;
for(k=0; k<xsp->nsubsym; k++){
SetAdd(newcfp->fws, xsp->subsym[k]->index);
}
break;
}else{
SetUnion(newcfp->fws,xsp->firstset);
if( xsp->lambda==B_FALSE ) break;
@ -2091,7 +2139,7 @@ to follow the previous rule.");
}else if( isalpha(x[0]) ){
if( psp->nrhs>=MAXRHS ){
ErrorMsg(psp->filename,psp->tokenlineno,
"Too many symbol on RHS or rule beginning at \"%s\".",
"Too many symbols on RHS or rule beginning at \"%s\".",
x);
psp->errorcnt++;
psp->state = RESYNC_AFTER_RULE_ERROR;
@ -2100,6 +2148,27 @@ to follow the previous rule.");
psp->alias[psp->nrhs] = 0;
psp->nrhs++;
}
}else if( (x[0]=='|' || x[0]=='/') && psp->nrhs>0 ){
struct symbol *msp = psp->rhs[psp->nrhs-1];
if( msp->type!=MULTITERMINAL ){
struct symbol *origsp = msp;
msp = malloc(sizeof(*msp));
memset(msp, 0, sizeof(*msp));
msp->type = MULTITERMINAL;
msp->nsubsym = 1;
msp->subsym = malloc(sizeof(struct symbol*));
msp->subsym[0] = origsp;
msp->name = origsp->name;
psp->rhs[psp->nrhs-1] = msp;
}
msp->nsubsym++;
msp->subsym = realloc(msp->subsym, sizeof(struct symbol*)*msp->nsubsym);
msp->subsym[msp->nsubsym-1] = Symbol_new(&x[1]);
if( islower(x[1]) || islower(msp->subsym[0]->name[0]) ){
ErrorMsg(psp->filename,psp->tokenlineno,
"Cannot form a compound containing a non-terminal");
psp->errorcnt++;
}
}else if( x[0]=='(' && psp->nrhs>0 ){
psp->state = RHS_ALIAS_1;
}else{
@ -2487,6 +2556,10 @@ struct lemon *gp;
}else if( c==':' && cp[1]==':' && cp[2]=='=' ){ /* The operator "::=" */
cp += 3;
nextcp = cp;
}else if( (c=='/' || c=='|') && isalpha(cp[1]) ){
cp += 2;
while( (c = *cp)!=0 && (isalnum(c) || c=='_') ) cp++;
nextcp = cp;
}else{ /* All other (one character) operators */
cp++;
nextcp = cp;
@ -2646,15 +2719,21 @@ struct lemon *lemp;
}
for(rp=lemp->rule; rp; rp=rp->next){
printf("%s",rp->lhs->name);
/* if( rp->lhsalias ) printf("(%s)",rp->lhsalias); */
/* if( rp->lhsalias ) printf("(%s)",rp->lhsalias); */
printf(" ::=");
for(i=0; i<rp->nrhs; i++){
printf(" %s",rp->rhs[i]->name);
/* if( rp->rhsalias[i] ) printf("(%s)",rp->rhsalias[i]); */
sp = rp->rhs[i];
printf(" %s", sp->name);
if( sp->type==MULTITERMINAL ){
for(j=1; j<sp->nsubsym; j++){
printf("|%s", sp->subsym[j]->name);
}
}
/* if( rp->rhsalias[i] ) printf("(%s)",rp->rhsalias[i]); */
}
printf(".");
if( rp->precsym ) printf(" [%s]",rp->precsym->name);
/* if( rp->code ) printf("\n %s",rp->code); */
/* if( rp->code ) printf("\n %s",rp->code); */
printf("\n");
}
}
@ -2664,18 +2743,25 @@ FILE *fp;
struct config *cfp;
{
struct rule *rp;
int i;
struct symbol *sp;
int i, j;
rp = cfp->rp;
fprintf(fp,"%s ::=",rp->lhs->name);
for(i=0; i<=rp->nrhs; i++){
if( i==cfp->dot ) fprintf(fp," *");
if( i==rp->nrhs ) break;
fprintf(fp," %s",rp->rhs[i]->name);
sp = rp->rhs[i];
fprintf(fp," %s", sp->name);
if( sp->type==MULTITERMINAL ){
for(j=1; j<sp->nsubsym; j++){
fprintf(fp,"|%s",sp->subsym[j]->name);
}
}
}
}
/* #define TEST */
#ifdef TEST
#if 0
/* Print a set */
PRIVATE void SetPrint(out,set,lemp)
FILE *out;
@ -2769,7 +2855,7 @@ struct lemon *lemp;
}
ConfigPrint(fp,cfp);
fprintf(fp,"\n");
#ifdef TEST
#if 0
SetPrint(fp,cfp->fws,lemp);
PlinkPrint(fp,cfp->fplp,"To ");
PlinkPrint(fp,cfp->bplp,"From");
@ -3113,8 +3199,14 @@ PRIVATE void translate_code(struct lemon *lemp, struct rule *rp){
** the token number of X, not the value of X */
append_str("yymsp[%d].major",-1,i-rp->nrhs+1,0);
}else{
append_str("yymsp[%d].minor.yy%d",0,
i-rp->nrhs+1,rp->rhs[i]->dtnum);
struct symbol *sp = rp->rhs[i];
int dtnum;
if( sp->type==MULTITERMINAL ){
dtnum = sp->subsym[0]->dtnum;
}else{
dtnum = sp->dtnum;
}
append_str("yymsp[%d].minor.yy%d",0,i-rp->nrhs+1, dtnum);
}
cp = xp;
used[i] = 1;
@ -3636,7 +3728,16 @@ int mhflag; /* Output in makeheaders format if true */
for(i=0, rp=lemp->rule; rp; rp=rp->next, i++){
assert( rp->index==i );
fprintf(out," /* %3d */ \"%s ::=", i, rp->lhs->name);
for(j=0; j<rp->nrhs; j++) fprintf(out," %s",rp->rhs[j]->name);
for(j=0; j<rp->nrhs; j++){
struct symbol *sp = rp->rhs[j];
fprintf(out," %s", sp->name);
if( sp->type==MULTITERMINAL ){
int k;
for(k=1; k<sp->nsubsym; k++){
fprintf(out,"|%s",sp->subsym[k]->name);
}
}
}
fprintf(out,"\",\n"); lineno++;
}
tplt_xfer(lemp->name,in,out,&lineno);