cpp.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

{  char *pin;
   char *psav,*space;
   pin=inp;
   space=psav=malloc(WORK_AREA);
   for(;;) { /* accumulate pragma until linefeed */
      outp=inp=p;
      p=cotoken(p);
      pin=inp;
      if (*pin=='\n') break;
      while ( pin <p) *psav++= *pin++;
   }
   *psav = '\0';
   fprintf(fout,"# %d $pragma %s \n", lineno[ifno], space );
   return(p);
}

char *
dodef(p) register char *p; {/* process '#define' */
	register char *pin,*psav,*cf;
	char **pf,**qf; register int b;int c,params;
	register struct symtab *np;
	char *oldval;
	char *space, *newspace;
	char *formal[MAXFRM]; /* formal[n] is name of nth formal */
	char formtxt[BUFSIZ]; /* space for formal names */
	int opt_passcom=passcom;

	passcom=0;	/* don't put comments in macro expansions */

	++flslvl; /* prevent macro expansion during 'define' */
	p=skipbl(p); pin=inp;
	if ((toktyp+COFF)[*pin]!=IDENT) {
		ppwarn("illegal macro name"); while (*inp!='\n') p=skipbl(p);
		passcom=opt_passcom; return(p);
	}
	np=slookup(pin,p,1);
	if (oldval=np->value) free(lastcopy);	/* was previously defined */
	b=1; cf=pin;
	while (cf<p) {/* update macbit */
		c= *cf++; xmac1(c,b,|=); b=(b+b)&0xFF;
		if (cf!=p) xmac2(c,*cf,-1+(cf-pin),|=);
		else xmac2(c,0,-1+(cf-pin),|=);
	}
	params=0; outp=inp=p; p=cotoken(p); pin=inp;
	if (*pin=='(') {/* with parameters; identify the formals */
		cf=formtxt; pf=formal;
		for (;;) {
			p=skipbl(p); pin=inp;
			if (*pin=='\n') {
				--lineno[ifno]; --p; pperror("%s: missing )",np->name); break;
			}
			if (*pin==')') break;
			if (*pin==',') continue;
			if ((*pin=='\\') && (*++pin=='\n')) /* 3-9-88 LFL */
			    continue;
			if ((toktyp+COFF)[*pin]!=IDENT) {
				c= *p; *p='\0'; pperror("bad formal: %s",pin); *p=c;
			} else if (pf>= &formal[MAXFRM]) {
				c= *p; *p='\0'; pperror("too many formals: %s",pin); *p=c;
			} else {
				*pf++=cf; while (pin<p) *cf++= *pin++; *cf++='\0'; ++params;
			}
		}
		if (params==0) --params; /* #define foo() ... */
	} else if (*pin=='\n') {--lineno[ifno]; --p;}
	/* remember beginning of macro body, so that we can
	/* warn if a redefinition is different from old value.
	*/
	space=psav=malloc(WORK_AREA);
	if (space==NULL) {
		pperror("too much defining");
		passcom=opt_passcom;
		return(p);
	}
	*psav++ = '\0';
	for (;;) {/* accumulate definition until linefeed */
		outp=inp=p; p=cotoken(p); pin=inp;
		if (*pin=='\\' && pin[1]=='\n') {putc('\n',fout); continue;}	/* ignore escaped lf */
		if (*pin=='\n') break;
		if (params) {/* mark the appearance of formals in the definiton */
			if ((toktyp+COFF)[*pin]==IDENT) {
				for (qf=pf; --qf>=formal; ) {
					if (equfrm(*qf,pin,p)) {
						*psav++=qf-formal+1; *psav++=WARN; pin=p; break;
					}
				}
			} else if (*pin=='"' || *pin=='\''
# if gcos
					|| *pin=='`'
# endif
						) {/* inside quotation marks, too */
				char quoc= *pin;
				for (*psav++= *pin++; pin<p && *pin!=quoc; ) {
					while (pin<p && !isid(*pin)) *psav++= *pin++;
					cf=pin; while (cf<p && isid(*cf)) ++cf;
					for (qf=pf; --qf>=formal; ) {
						if (equfrm(*qf,pin,cf)) {
							*psav++=qf-formal+1; *psav++=WARN; pin=cf; break;
						}
					}
					while (pin<cf) *psav++= *pin++;
				}
			}
		}
		while (pin<p) *psav++= *pin++;
	}
	*psav++=params; *psav++='\0';
	if ((cf=oldval)!=NULL) {/* redefinition */
		--cf;	/* skip no. of params, which may be zero */
		while (*--cf);	/* go back to the beginning */
		if (0!=strcmp(++cf,space+1)) {/* redefinition different from old */
			--lineno[ifno]; ppwarn("%s redefined",np->name); ++lineno[ifno];
			np->value=psav-1;
		} else free(space); /* identical redef.; reclaim space */
	} else np->value=psav-1;
	--flslvl; inp=pin;
	if (np->value == psav-1) {
                if ((psav-space)<= WORK_AREA) {
          		newspace = realloc(space, psav-space);
		        if (newspace==NULL) {pperror("no space");exit(exfail);}
			/*
			 * Adjust pointer in case this moved.
			 */
			np->value += newspace-space;
		      }
                else {pperror("macro definition too long");exit(exfail);}
                    
	}
	passcom=opt_passcom;
	return(p);
}

#define fasscan() ptrtab=fastab+COFF
#define sloscan() ptrtab=slotab+COFF

void	/* DAG -- bug fix (was (char *)) */
control(p) register char *p; {/* find and handle preprocessor control lines */
	register struct symtab *np;
for (;;) {
	fasscan(); p=cotoken(p); if (*inp=='\n') ++inp; dump();
	sloscan(); p=skipbl(p);
	*--inp=SALT; outp=inp; ++flslvl; np=slookup(inp,p,0); --flslvl;
	if (np==defloc) {/* define */
		if (flslvl==0) {p=dodef(p); continue;}
        } else if (np== pragmaloc) { /* pragma */
             if ( flslvl==0) {p=dopragma(p);continue;}
	} else if (np==incloc) {/* include */
		if (flslvl==0) {p=doincl(p); continue;}
	} else if (np==ifnloc) {/* ifndef */
		++flslvl; p=skipbl(p); np=slookup(inp,p,0); --flslvl;
		if (flslvl==0)
			if(ifdone[trulvl] = np->value==0)
				++trulvl;
			else
				++flslvl;
		else ++flslvl;
	} else if (np==ifdloc) {/* ifdef */
		++flslvl; p=skipbl(p); np=slookup(inp,p,0); --flslvl;
		if (flslvl==0)
			if (ifdone[trulvl] = np->value!=0)
				++trulvl;
			else
				++flslvl;
		else ++flslvl;
	} else if (np==eifloc) {/* endif */
		if (flslvl) {if (--flslvl==0) sayline(CONT);}
		else if (trulvl) ifdone[--trulvl] = 0;	/* DAG */
		else pperror("If-less endif",0);
	} else if (np==elsloc) {/* else */
		if (flslvl) {
			if (--flslvl!=0 || ifdone[trulvl]) ++flslvl;
			else {++trulvl; sayline(CONT);}
		}
		else if (trulvl) {++flslvl; --trulvl;}
		else pperror("If-less else",0);
	} else if (np==udfloc) {/* undefine */
		if (flslvl==0) {
			++flslvl; p=skipbl(p); slookup(inp,p,DROP); --flslvl;
		}
	} else if (np==ifloc) {/* if */
#if tgp
		pperror(" IF not implemented, true assumed", 0);
		if (flslvl==0) ifdone[trulvl++] = 1; else ++flslvl;
#else
		newp=p;
		if (flslvl==0)
		{
			if (ifdone[trulvl] = yyparse())	/* DAG */
				++trulvl;
			else
				++flslvl;
		}
		else ++flslvl;
		p=newp;
#endif
	} else if (np==eliloc) {/* elif */	/* DAG -- added */
#if tgp
		pperror (" ELIF not implemented, true assumed", (char *) 0, (char *) 0);
		if (flslvl)
		{
			if (--flslvl == 0 && !ifdone[trulvl])
			{
				ifdone[trulvl++] = 1;
				--lineno[ifno];
				sayline (CONT);
				++lineno[ifno];
			}
			else
				++flslvl;
		}
		else if (trulvl)
		{
			++flslvl;
			--trulvl;
		}
		else
			pperror ( "If-less elif", (char *) 0, (char *) 0);
#else
		newp = p;
		if (flslvl)
		{
			if (--flslvl == 0 && !ifdone[trulvl] && yyparse ())
			{
				ifdone[trulvl++] = 1;
/*	Yyparse() finished this line.  Back up.  jlr009 */
				--lineno[ifno];
				sayline (CONT);
				++lineno[ifno];
			}
			else
				++flslvl;
		}
		else if (trulvl)
		{
			++flslvl;
			--trulvl;
		}
		else
			pperror ( "If-less elif", (char *) 0, (char *) 0);
		p = newp;
#endif
	} else if (np==lneloc) {/* line */
		if (flslvl==0 && pflag==0) {
			char *savestring();
			char filename[BUFSIZ], *cp = filename;
			outp=inp=p; *--outp='#';
			/* Find the line number.. */
			do {
				p = cotoken(p);
			} while (!isnum(*inp) && *inp != '\n');
			if (isnum(*inp))
				lineno[ifno] = atoi(inp)-1;
			/* Skip over the blank token */
			inp = p;
			if (*inp != '\n') {
				p = cotoken(p); inp = p;
			}
			/* Add a quote if missing..  */
			if (*inp != '\n') {
				p = cotoken(p);
				/* Add a quote if missing..  */
				if (*inp == '"')
					inp++;
				else {
					dump();
					*--outp = '"';
				}
				while (*inp != '\n') {
					while (inp < p && *inp != '"' &&
						cp < filename+sizeof(filename))
						*cp++ = *inp++;
					if (*inp == '"')
						break;
					inp = p; p = cotoken(p);
				}
				fnames[ifno] = savestring(filename, cp);
				/* Add a quote if missing..  */
				if (*inp != '"') {
					dump();
					*--outp = '"';
				}
			}
			while (*inp != '\n')
				p = cotoken(p);
			continue;
		}
	} else if (np==identloc) {/* ident (for Sys 5r3 compat) */
		/* remove this cause we don't want to want to pass it
		 * -- if we ever do remove this comment around the following
		 * 	code
		 *	while(*inp!='\n') p=cotoken(p);
		 */
	} else if (*++inp=='\n') outp=inp;	/* allows blank line after # */
	else pperror("undefined control",0);
	/* flush to lf */
	++flslvl; while (*inp!='\n') {outp=inp=p; p=cotoken(p);} --flslvl;
}
}

char *
savestring(start, finish)
	register char *start, *finish;
{
	register char *retbuf;
	register char *cp;

	retbuf = (char *) calloc(finish - start + 1, sizeof (char));
	cp = retbuf;
	while (start < finish)
		*cp++ = *start++;
	*cp = 0;
	return(retbuf);
}

struct symtab *
stsym(s) register char *s; {
	char buf[BUFSIZ]; register char *p;

	/* make definition look exactly like end of #define line */
	/* copy to avoid running off end of world when param list is at end */
	p=buf; while (*p++= *s++);
	p=buf; while (isid(*p++)); /* skip first identifier */
	if (*--p=='=') {*p++=' '; while (*p++);}
	else {s=" 1"; while (*p++= *s++);}
	pend=p; *--p='\n';
	sloscan(); dodef(buf); return(lastsym);
}

struct symtab *
ppsym(s) register char *s; {/* kluge */
	register struct symtab *sp;
	register char *name;

	cinit=SALT; sp=stsym(s); name = malloc(strlen(sp->name)+1+1);
	name[0] = '#'; strcpy(name+1, sp->name); sp->name = name;
	cinit=0; return(sp);
}

#ifdef notdef
/* VARARGS1 */
pperror(s,x,y) char *s; {
	if (fnames[ifno][0]) fprintf(stderr,
# if gcos
			"*%c*   \"%s\", line ", exfail >= 0 ? 'F' : 'W',
# else
			"%s: ",
# endif
				 fnames[ifno]);
	fprintf(stderr, "%d: ",lineno[ifno]);
	fprintf(stderr, s, x, y);
	fprintf(stderr,"\n");
	++exfail;
}
#endif

/* VARARGS1 */
pperror(s,x,y) char *s; {
	fprintf(stderr, "cpp: error ");
	if (fnames[ifno][0])
		fprintf(stderr, "%s:", fnames[ifno]);
	fprintf(stderr, "%d: ", lineno[ifno]);
	fprintf(stderr, s, x, y);
	fprintf(stderr,"\n");
	++exfail;
}

/* VARARGS1 */
ppwarn(s,x,y) char *s; {
	fprintf(stderr, "cpp: warning ");
	if (fnames[ifno][0])
		fprintf(stderr, "%s:", fnames[ifno]);
	fprintf(stderr, "%d: ", lineno[ifno]);
	fprintf(stderr, s, x, y);
	fprintf(stderr,"\n");
}

yyerror(s,a,b) char *s; {
	pperror(s,a,b);
}

struct symtab *
lookup(namep, enterf)
register char *namep;
{
	register char *np, *snp;
	register int c, i; int around;
	register struct symtab *sp;

	/* namep had better not be too long (currently, <=NCPS chars) */
	np=namep; around=0; i=cinit;
	while (c= *np++) i += i+c; c=i;	/* c=i for register usage on pdp11 */
	c %= symsiz; if (c<0) c += symsiz;
	sp = &stab[c];
	while (snp=sp->name) {
		np = namep;
		while (*snp++ == *np) if (*np++ == '\0') {
				if (enterf==DROP) {sp->name[0]= DROP; sp->value=0;}
				return(lastsym=sp);
			}
		if (--sp < &stab[0])
			if (around) {pperror("too many defines", 0); exit(exfail);}
			else {++around; sp = &stab[symsiz-1];}
	}
	if (enterf==1) sp->name=namep;
	return(lastsym=sp);
}

struct symtab *
slookup(p1,p2,enterf) register char *p1,*p2; register int enterf;{
	register char *p3; char c2,c3; register struct symtab *np;
	         c2= *p2; *p2='\0';	/* mark end of token */
	if ((p2-p1)>NCPS) p3=p1+NCPS; else p3=p2;
			 c3= *p3; *p3='\0';	/* truncate to NCPS chars or less */