gram.y

unix v7是最后一个广泛发布的研究型UNIX版本

%{#include "defs"
%}

%term NAME SHELLINE START MACRODEF COLON DOUBLECOLON GREATER
%union
	{
	struct shblock *yshblock;
	struct depblock *ydepblock;
	struct nameblock *ynameblock;
	}

%type <yshblock> SHELLINE, shlist, shellist
%type <ynameblock> NAME, namelist
%type <ydepblock> deplist, dlist


%%

%{
struct depblock *pp;
FSTATIC struct shblock *prevshp;

FSTATIC struct nameblock *lefts[NLEFTS];
struct nameblock *leftp;
FSTATIC int nlefts;

struct lineblock *lp, *lpp;
FSTATIC struct depblock *prevdep;
FSTATIC int sepc;
%}


file:
	| file comline
	;

comline:  START
	| MACRODEF
	| START namelist deplist shellist = {
	    while( --nlefts >= 0)
		{
		leftp = lefts[nlefts];
		if(leftp->septype == 0)
			leftp->septype = sepc;
		else if(leftp->septype != sepc)
			fprintf(stderr, "Inconsistent rules lines for `%s'\n",
				leftp->namep);
		else if(sepc==ALLDEPS && *(leftp->namep)!='.' && $4!=0)
			{
			for(lp=leftp->linep; lp->nxtlineblock!=0; lp=lp->nxtlineblock)
			    if(lp->shp)
				fprintf(stderr, "Multiple rules lines for `%s'\n",
				    leftp->namep);
			}

		lp = ALLOC(lineblock);
		lp->nxtlineblock = NULL;
		lp->depp = $3;
		lp->shp = $4;

		if(! unequal(leftp->namep, ".SUFFIXES") && $3==0)
			leftp->linep = 0;
		else if(leftp->linep == 0)
			leftp->linep = lp;
		else	{
			for(lpp = leftp->linep; lpp->nxtlineblock;
				lpp = lpp->nxtlineblock) ;
				if(sepc==ALLDEPS && leftp->namep[0]=='.')
					lpp->shp = 0;
			lpp->nxtlineblock = lp;
			}
		}
	}
	| error
	;

namelist: NAME	= { lefts[0] = $1; nlefts = 1; }
	| namelist NAME	= { lefts[nlefts++] = $2;
	    	if(nlefts>NLEFTS) fatal("Too many lefts"); }
	;

deplist:
		{
		char junk[10];
		sprintf(junk, "%d", yylineno);
		fatal1("Must be a separator on rules line %s", junk);
		}
	| dlist
	;

dlist:  sepchar	= { prevdep = 0;  $$ = 0; }
	| dlist NAME	= {
			  pp = ALLOC(depblock);
			  pp->nxtdepblock = NULL;
			  pp->depname = $2;
			  if(prevdep == 0) $$ = pp;
			  else  prevdep->nxtdepblock = pp;
			  prevdep = pp;
			  }
	;

sepchar:  COLON 	= { sepc = ALLDEPS; }
	| DOUBLECOLON	= { sepc = SOMEDEPS; }
	;

shellist:	= {$$ = 0; }
	| shlist = { $$ = $1; }
	;

shlist:	SHELLINE   = { $$ = $1;  prevshp = $1; }
	| shlist SHELLINE = { $$ = $1;
			prevshp->nxtshblock = $2;
			prevshp = $2;
			}
	;

%%

char *zznextc;	/* zero if need another line; otherwise points to next char */
int yylineno;
extern FILE * fin;

yylex()
{
register char *p;
register char *q;
char word[INMAX];

if(zznextc == 0)
	return( nextlin() );

while( isspace(*zznextc) )
	++zznextc;

if(*zznextc == '\0')
	return( nextlin() );

if(*zznextc == ':')
	{
	if(*++zznextc == ':')
		{
		++zznextc;
		return(DOUBLECOLON);
		}
	else	return(COLON);
	}

if(*zznextc == '>')
	{
	++zznextc;
	return(GREATER);
	}

if(*zznextc == ';')
	return( retsh(zznextc) );

p = zznextc;
q = word;

while( ! ( funny[*p] & TERMINAL) )
	*q++ = *p++;

if(p != zznextc)
	{
	*q = '\0';
	if((yylval.ynameblock=srchname(word))==0)
		yylval.ynameblock = makename(word);
	zznextc = p;
	return(NAME);
	}

else	{
	fprintf(stderr,"Bad character %c (octal %o), line %d",
		*zznextc,*zznextc,yylineno);
	fatal( (char *) NULL );
	}
return(0);	/* never executed */
}





retsh(q)
char *q;
{
register char *p;
struct shblock *sp;
char *copys();

for(p=q+1 ; *p==' '||*p=='\t' ; ++p)  ;

sp = ALLOC(shblock);
sp->nxtshblock = NULL;
sp->shbp = (fin == NULL ? p : copys(p) );
yylval.yshblock = sp;
zznextc = 0;
return(SHELLINE);
}

nextlin()
{
static char yytext[INMAX];
static char *yytextl	= yytext+INMAX;
char *text, templin[INMAX];
register char c;
register char *p, *t;
char lastch, *lastchp;
extern char **linesptr;
int incom;
int kc;

again:

	incom = NO;
	zznextc = 0;

if(fin == NULL)
	{
	if( (text = *linesptr++) == 0)
		return(0);
	++yylineno;
	}

else	{
	for(p = text = yytext ; p<yytextl ; *p++ = kc)
		switch(kc = getc(fin))
			{
			case '\t':
				if(p != yytext)
					break;
			case ';':
				incom = YES;
				break;

			case '#':
				if(! incom)
					kc = '\0';
				break;

			case '\n':
				++yylineno;
				if(p==yytext || p[-1]!='\\')
					{
					*p = '\0';
					goto endloop;
					}
				p[-1] = ' ';
				while( (kc=getc(fin))=='\t' || kc==' ' || kc=='\n')
					if(kc == '\n')
						++yylineno;
	
				if(kc != EOF)
					break;
			case EOF:
				*p = '\0';
				return(0);
			}

	fatal("line too long");
	}

endloop:

	if((c = text[0]) == '\t')
		return( retsh(text) );
	
	if(isalpha(c) || isdigit(c) || c==' ' || c=='.')
		for(p=text+1; *p!='\0'; )
			if(*p == ':')
				break;
			else if(*p++ == '=')
				{
				eqsign(text);
				return(MACRODEF);
				}

/* substitute for macros on dependency line up to the semicolon if any */

for(t = yytext ; *t!='\0' && *t!=';' ; ++t)
	;

lastchp = t;
lastch = *t;
*t = '\0';

subst(yytext, templin);		/* Substitute for macros on dependency lines */

if(lastch)
	{
	for(t = templin ; *t ; ++t)
		;
	*t = lastch;
	while( *++t = *++lastchp ) ;
	}

p = templin;
t = yytext;
while( *t++ = *p++ )
	;

for(p = zznextc = text ; *p ; ++p )
	if(*p!=' ' && *p!='\t')
		return(START);
goto again;
}