ref: cbe4b116989c0bfec49b9ae7a1d9a85ead6648ae
dir: /sys/src/cmd/lex/parser.y/
%token CHAR CCL NCCL STR DELIM SCON ITER NEWE NULLS
%left SCON '/' NEWE
%left '|'
%left '$' '^'
%left CHAR CCL NCCL '(' '.' STR NULLS
%left ITER
%left CAT
%left '*' '+' '?'
%{
# include "ldefs.h"
#define YYSTYPE union _yystype_
union _yystype_
{
int i;
uchar *cp;
};
%}
%%
%{
int i;
int j,k;
int g;
uchar *p;
%}
acc : lexinput
={
# ifdef DEBUG
if(debug) sect2dump();
# endif
}
;
lexinput: defns delim prods end
| defns delim end
={
if(!funcflag)phead2();
funcflag = TRUE;
}
| error
={
# ifdef DEBUG
if(debug) {
sect1dump();
sect2dump();
}
# endif
}
;
end: delim | ;
defns: defns STR STR
={ strcpy((char*)dp,(char*)$2.cp);
def[dptr] = dp;
dp += strlen((char*)$2.cp) + 1;
strcpy((char*)dp,(char*)$3.cp);
subs[dptr++] = dp;
if(dptr >= DEFSIZE)
error("Too many definitions");
dp += strlen((char*)$3.cp) + 1;
if(dp >= dchar+DEFCHAR)
error("Definitions too long");
subs[dptr]=def[dptr]=0; /* for lookup - require ending null */
}
|
;
delim: DELIM
={
# ifdef DEBUG
if(sect == DEFSECTION && debug) sect1dump();
# endif
sect++;
}
;
prods: prods pr
={ $$.i = mn2(RNEWE,$1.i,$2.i);
}
| pr
={ $$.i = $1.i;}
;
pr: r NEWE
={
if(divflg == TRUE)
i = mn1(S1FINAL,casecount);
else i = mn1(FINAL,casecount);
$$.i = mn2(RCAT,$1.i,i);
divflg = FALSE;
casecount++;
}
| error NEWE
={
# ifdef DEBUG
if(debug) sect2dump();
# endif
}
r: CHAR
={ $$.i = mn0($1.i); }
| STR
={
p = $1.cp;
i = mn0(*p++);
while(*p)
i = mn2(RSTR,i,*p++);
$$.i = i;
}
| '.'
={ symbol['\n'] = 0;
if(psave == FALSE){
p = ccptr;
psave = ccptr;
for(i=1;i<'\n';i++){
symbol[i] = 1;
*ccptr++ = i;
}
for(i='\n'+1;i<NCH;i++){
symbol[i] = 1;
*ccptr++ = i;
}
*ccptr++ = 0;
if(ccptr > ccl+CCLSIZE)
error("Too many large character classes");
}
else
p = psave;
$$.i = mnp(RCCL, p);
cclinter(1);
}
| CCL
={ $$.i = mnp(RCCL,$1.cp); }
| NCCL
={ $$.i = mnp(RNCCL,$1.cp); }
| r '*'
={ $$.i = mn1(STAR,$1.i); }
| r '+'
={ $$.i = mn1(PLUS,$1.i); }
| r '?'
={ $$.i = mn1(QUEST,$1.i); }
| r '|' r
={ $$.i = mn2(BAR,$1.i,$3.i); }
| r r %prec CAT
={ $$.i = mn2(RCAT,$1.i,$2.i); }
| r '/' r
={ if(!divflg){
j = mn1(S2FINAL,-casecount);
i = mn2(RCAT,$1.i,j);
$$.i = mn2(DIV,i,$3.i);
}
else {
$$.i = mn2(RCAT,$1.i,$3.i);
warning("Extra slash removed");
}
divflg = TRUE;
}
| r ITER ',' ITER '}'
={ if($2.i > $4.i){
i = $2.i;
$2.i = $4.i;
$4.i = i;
}
if($4.i <= 0)
warning("Iteration range must be positive");
else {
j = $1.i;
for(k = 2; k<=$2.i;k++)
j = mn2(RCAT,j,dupl($1.i));
for(i = $2.i+1; i<=$4.i; i++){
g = dupl($1.i);
for(k=2;k<=i;k++)
g = mn2(RCAT,g,dupl($1.i));
j = mn2(BAR,j,g);
}
$$.i = j;
}
}
| r ITER '}'
={
if($2.i < 0)warning("Can't have negative iteration");
else if($2.i == 0) $$.i = mn0(RNULLS);
else {
j = $1.i;
for(k=2;k<=$2.i;k++)
j = mn2(RCAT,j,dupl($1.i));
$$.i = j;
}
}
| r ITER ',' '}'
={
/* from n to infinity */
if($2.i < 0)warning("Can't have negative iteration");
else if($2.i == 0) $$.i = mn1(STAR,$1.i);
else if($2.i == 1)$$.i = mn1(PLUS,$1.i);
else { /* >= 2 iterations minimum */
j = $1.i;
for(k=2;k<$2.i;k++)
j = mn2(RCAT,j,dupl($1.i));
k = mn1(PLUS,dupl($1.i));
$$.i = mn2(RCAT,j,k);
}
}
| SCON r
={ $$.i = mn2(RSCON,$2.i,$1.i); }
| '^' r
={ $$.i = mn1(CARAT,$2.i); }
| r '$'
={ i = mn0('\n');
if(!divflg){
j = mn1(S2FINAL,-casecount);
k = mn2(RCAT,$1.i,j);
$$.i = mn2(DIV,k,i);
}
else $$.i = mn2(RCAT,$1.i,i);
divflg = TRUE;
}
| '(' r ')'
={ $$.i = $2.i; }
| NULLS
={ $$.i = mn0(RNULLS); }
;
%%
int
yylex(void)
{
uchar *p;
int c, i;
uchar *t, *xp;
int n, j, k, x;
static int sectbegin;
static uchar token[TOKENSIZE];
static int iter;
# ifdef DEBUG
yylval.i = 0;
yylval.p = 0;
# endif
if(sect == DEFSECTION) { /* definitions section */
while(!eof) {
if(prev == '\n'){ /* next char is at beginning of line */
getl(p=buf);
switch(*p){
case '%':
switch(*(p+1)){
case '%':
lgate();
Bprint(&fout,"#define YYNEWLINE %d\n",'\n');
Bprint(&fout,"yylex(void){\nint nstr; extern int yyprevious;\n");
sectbegin = TRUE;
i = treesize*(sizeof(*name)+sizeof(*left)+
sizeof(*right)+sizeof(*nullstr)+sizeof(*parent))+ALITTLEEXTRA;
p = myalloc(i,1);
if(p == 0)
error("Too little core for parse tree");
free(p);
name = myalloc(treesize,sizeof(*name));
left = myalloc(treesize,sizeof(*left));
right = myalloc(treesize,sizeof(*right));
nullstr = myalloc(treesize,sizeof(*nullstr));
parent = myalloc(treesize,sizeof(*parent));
ptr = myalloc(treesize,sizeof(*ptr));
if(name == 0 || left == 0 || right == 0 || parent == 0 || nullstr == 0 || ptr == 0)
error("Too little core for parse tree");
return(freturn(DELIM));
case 'p': case 'P': /* has overridden number of positions */
while(*p && !isdigit(*p))p++;
maxpos = atol((char*)p);
# ifdef DEBUG
if (debug) print("positions (%%p) now %d\n",maxpos);
# endif
if(report == 2)report = 1;
continue;
case 'n': case 'N': /* has overridden number of states */
while(*p && !isdigit(*p))p++;
nstates = atol((char*)p);
# ifdef DEBUG
if(debug)print( " no. states (%%n) now %d\n",nstates);
# endif
if(report == 2)report = 1;
continue;
case 'e': case 'E': /* has overridden number of tree nodes */
while(*p && !isdigit(*p))p++;
treesize = atol((char*)p);
# ifdef DEBUG
if (debug) print("treesize (%%e) now %d\n",treesize);
# endif
if(report == 2)report = 1;
continue;
case 'o': case 'O':
while (*p && !isdigit(*p))p++;
outsize = atol((char*)p);
if (report ==2) report=1;
continue;
case 'a': case 'A': /* has overridden number of transitions */
while(*p && !isdigit(*p))p++;
if(report == 2)report = 1;
ntrans = atol((char*)p);
# ifdef DEBUG
if (debug)print("N. trans (%%a) now %d\n",ntrans);
# endif
continue;
case 'k': case 'K': /* overriden packed char classes */
while (*p && !isdigit(*p))p++;
if (report==2) report=1;
free(pchar);
pchlen = atol((char*)p);
# ifdef DEBUG
if (debug) print( "Size classes (%%k) now %d\n",pchlen);
# endif
pchar=pcptr=myalloc(pchlen, sizeof(*pchar));
continue;
case '{':
lgate();
while(getl(p) && strcmp((char*)p,"%}") != 0)
Bprint(&fout, "%s\n",(char*)p);
if(p[0] == '%') continue;
error("Premature eof");
case 's': case 'S': /* start conditions */
lgate();
while(*p && strchr(" \t,", *p) == 0) p++;
n = TRUE;
while(n){
while(*p && strchr(" \t,", *p)) p++;
t = p;
while(*p && strchr(" \t,", *p) == 0)p++;
if(!*p) n = FALSE;
*p++ = 0;
if (*t == 0) continue;
i = sptr*2;
Bprint(&fout,"#define %s %d\n",(char*)t,i);
strcpy((char*)sp, (char*)t);
sname[sptr++] = sp;
sname[sptr] = 0; /* required by lookup */
if(sptr >= STARTSIZE)
error("Too many start conditions");
sp += strlen((char*)sp) + 1;
if(sp >= stchar+STARTCHAR)
error("Start conditions too long");
}
continue;
default:
warning("Invalid request %s",p);
continue;
} /* end of switch after seeing '%' */
case ' ': case '\t': /* must be code */
lgate();
Bprint(&fout, "%s\n",(char*)p);
continue;
default: /* definition */
while(*p && !isspace(*p)) p++;
if(*p == 0)
continue;
prev = *p;
*p = 0;
bptr = p+1;
yylval.cp = buf;
if(isdigit(buf[0]))
warning("Substitution strings may not begin with digits");
return(freturn(STR));
}
}
/* still sect 1, but prev != '\n' */
else {
p = bptr;
while(*p && isspace(*p)) p++;
if(*p == 0)
warning("No translation given - null string assumed");
strcpy((char*)token, (char*)p);
yylval.cp = token;
prev = '\n';
return(freturn(STR));
}
}
/* end of section one processing */
} else if(sect == RULESECTION){ /* rules and actions */
while(!eof){
switch(c=gch()){
case '\0':
return(freturn(0));
case '\n':
if(prev == '\n') continue;
x = NEWE;
break;
case ' ':
case '\t':
if(sectbegin == TRUE){
cpyact();
while((c=gch()) && c != '\n');
continue;
}
if(!funcflag)phead2();
funcflag = TRUE;
Bprint(&fout,"case %d:\n",casecount);
if(cpyact())
Bprint(&fout,"break;\n");
while((c=gch()) && c != '\n');
if(peek == ' ' || peek == '\t' || sectbegin == TRUE){
warning("Executable statements should occur right after %%");
continue;
}
x = NEWE;
break;
case '%':
if(prev != '\n') goto character;
if(peek == '{'){ /* included code */
getl(buf);
while(!eof && getl(buf) && strcmp("%}",(char*)buf) != 0)
Bprint(&fout,"%s\n",(char*)buf);
continue;
}
if(peek == '%'){
gch();
gch();
x = DELIM;
break;
}
goto character;
case '|':
if(peek == ' ' || peek == '\t' || peek == '\n'){
Bprint(&fout,"%d\n",30000+casecount++);
continue;
}
x = '|';
break;
case '$':
if(peek == '\n' || peek == ' ' || peek == '\t' || peek == '|' || peek == '/'){
x = c;
break;
}
goto character;
case '^':
if(prev != '\n' && scon != TRUE) goto character; /* valid only at line begin */
x = c;
break;
case '?':
case '+':
case '.':
case '*':
case '(':
case ')':
case ',':
case '/':
x = c;
break;
case '}':
iter = FALSE;
x = c;
break;
case '{': /* either iteration or definition */
if(isdigit(c=gch())){ /* iteration */
iter = TRUE;
ieval:
i = 0;
while(isdigit(c)){
token[i++] = c;
c = gch();
}
token[i] = 0;
yylval.i = atol((char*)token);
munputc(c);
x = ITER;
break;
} else { /* definition */
i = 0;
while(c && c!='}'){
token[i++] = c;
c = gch();
}
token[i] = 0;
i = lookup(token,def);
if(i < 0)
warning("Definition %s not found",token);
else
munputs(subs[i]);
continue;
}
case '<': /* start condition ? */
if(prev != '\n') /* not at line begin, not start */
goto character;
t = slptr;
do {
i = 0;
c = gch();
while(c != ',' && c && c != '>'){
token[i++] = c;
c = gch();
}
token[i] = 0;
if(i == 0)
goto character;
i = lookup(token,sname);
if(i < 0) {
warning("Undefined start condition %s",token);
continue;
}
*slptr++ = i+1;
} while(c && c != '>');
*slptr++ = 0;
/* check if previous value re-usable */
for (xp=slist; xp<t; ){
if (strcmp((char*)xp, (char*)t)==0)
break;
while (*xp++);
}
if (xp<t){
/* re-use previous pointer to string */
slptr=t;
t=xp;
}
if(slptr > slist+STARTSIZE) /* note not packed ! */
error("Too many start conditions used");
yylval.cp = t;
x = SCON;
break;
case '"':
i = 0;
while((c=gch()) && c != '"' && c != '\n'){
if(c == '\\') c = usescape(gch());
token[i++] = c;
if(i > TOKENSIZE){
warning("String too long");
i = TOKENSIZE-1;
break;
}
}
if(c == '\n') {
yyline--;
warning("Non-terminated string");
yyline++;
}
token[i] = 0;
if(i == 0)x = NULLS;
else if(i == 1){
yylval.i = token[0];
x = CHAR;
} else {
yylval.cp = token;
x = STR;
}
break;
case '[':
for(i=1;i<NCH;i++) symbol[i] = 0;
x = CCL;
if((c = gch()) == '^'){
x = NCCL;
c = gch();
}
while(c != ']' && c){
if(c == '\\') c = usescape(gch());
symbol[c] = 1;
j = c;
if((c=gch()) == '-' && peek != ']'){ /* range specified */
c = gch();
if(c == '\\') c = usescape(gch());
k = c;
if(j > k) {
n = j;
j = k;
k = n;
}
if(!(('A' <= j && k <= 'Z') ||
('a' <= j && k <= 'z') ||
('0' <= j && k <= '9')))
warning("Non-portable Character Class");
for(n=j+1;n<=k;n++)
symbol[n] = 1; /* implementation dependent */
c = gch();
}
}
/* try to pack ccl's */
i = 0;
for(j=0;j<NCH;j++)
if(symbol[j])token[i++] = j;
token[i] = 0;
p = ccl;
while(p <ccptr && strcmp((char*)token,(char*)p) != 0)p++;
if(p < ccptr) /* found it */
yylval.cp = p;
else {
yylval.cp = ccptr;
strcpy((char*)ccptr,(char*)token);
ccptr += strlen((char*)token) + 1;
if(ccptr >= ccl+CCLSIZE)
error("Too many large character classes");
}
cclinter(x==CCL);
break;
case '\\':
c = usescape(gch());
default:
character:
if(iter){ /* second part of an iteration */
iter = FALSE;
if('0' <= c && c <= '9')
goto ieval;
}
if(isalpha(peek)){
i = 0;
yylval.cp = token;
token[i++] = c;
while(isalpha(peek))
token[i++] = gch();
if(peek == '?' || peek == '*' || peek == '+')
munputc(token[--i]);
token[i] = 0;
if(i == 1){
yylval.i = token[0];
x = CHAR;
}
else x = STR;
} else {
yylval.i = c;
x = CHAR;
}
}
scon = FALSE;
if(x == SCON)scon = TRUE;
sectbegin = FALSE;
return(freturn(x));
}
}
/* section three */
ptail();
# ifdef DEBUG
if(debug)
Bprint(&fout,"\n/*this comes from section three - debug */\n");
# endif
while(getl(buf) && !eof)
Bprint(&fout,"%s\n",(char*)buf);
return(freturn(0));
}
/* end of yylex */
# ifdef DEBUG
int
freturn(int i)
{
if(yydebug) {
print("now return ");
if(i < NCH) allprint(i);
else print("%d",i);
print(" yylval = ");
switch(i){
case STR: case CCL: case NCCL:
strpt(yylval.cp);
break;
case CHAR:
allprint(yylval.i);
break;
default:
print("%d",yylval.i);
break;
}
print("\n");
}
return(i);
}
# endif