cpp.c

unix v7是最后一个广泛发布的研究型UNIX版本

							/* and fake start of 2nd */
							outp=inp=p-=3; *p++='/'; *p++='*'; *p++='*';
						} else p=refill(p);
					} else break;
				} else if (p[-1]=='\n') {
					++lineno[ifno]; if (!passcom) putc('\n',fout);
				} else if (eob(--p)) {
					if (!passcom) {inp=p; p=refill(p);}
					else if ((p-inp)>=BUFSIZ) {/* split long comment */
						inp=p; p=refill(p);
						putc('*',fout); putc('/',fout);
						outp=inp=p-=2; *p++='/'; *p++='*';
					} else p=refill(p);
				} else ++p; /* ignore null byte */
			}
		endcom:
			if (!passcom) {outp=inp=p; --flslvl; goto again;}
			break;
		}
		if (eob(--p)) p=refill(p);
		else break;
	} break;
# if gcos
	case '`':
# endif
	case '"': case '\'': {
		quoc=p[-1];
		for (;;) {
			while (!isquo(*p++));
			if (p[-1]==quoc) break;
			if (p[-1]=='\n') {--p; break;} /* bare \n terminates quotation */
			if (p[-1]=='\\') for (;;) {
				if (*p++=='\n') {++lineno[ifno]; break;} /* escaped \n ignored */
				if (eob(--p)) p=refill(p);
				else {++p; break;}
			} else if (eob(--p)) p=refill(p);
			else ++p;	/* it was a different quote character */
		}
	} break;
	case '\n': {
		++lineno[ifno]; if (isslo) {state=LF; return(p);}
prevlf:
		state=BEG;
		for (;;) {
			if (*p++=='#') return(p);
			if (eob(inp= --p)) p=refill(p);
			else goto again;
		}
	} break;
	case '0': case '1': case '2': case '3': case '4':
	case '5': case '6': case '7': case '8': case '9':
	for (;;) {
		while (isnum(*p++));
		if (eob(--p)) p=refill(p);
		else break;
	} break;
	case 'A': case 'B': case 'C': case 'D': case 'E':
	case 'F': case 'G': case 'H': case 'I': case 'J':
	case 'K': case 'L': case 'M': case 'N': case 'O':
	case 'P': case 'Q': case 'R': case 'S': case 'T':
	case 'U': case 'V': case 'W': case 'X': case 'Y':
	case 'Z': case '_':
	case 'a': case 'b': case 'c': case 'd': case 'e':
	case 'f': case 'g': case 'h': case 'i': case 'j':
	case 'k': case 'l': case 'm': case 'n': case 'o':
	case 'p': case 'q': case 'r': case 's': case 't':
	case 'u': case 'v': case 'w': case 'x': case 'y':
	case 'z':
#if scw1
#define tmac1(c,bit) if (!xmac1(c,bit,&)) goto nomac
#define xmac1(c,bit,op) ((macbit+COFF)[c] op (bit))
#else
#define tmac1(c,bit)
#define xmac1(c,bit,op)
#endif

#if scw2
#define tmac2(c0,c1,cpos) if (!xmac2(c0,c1,cpos,&)) goto nomac
#define xmac2(c0,c1,cpos,op)\
	((macbit+COFF)[(t21+COFF)[c0]+(t22+COFF)[c1]] op (t23+COFF+cpos)[c0])
#else
#define tmac2(c0,c1,cpos)
#define xmac2(c0,c1,cpos,op)
#endif

	if (flslvl) goto nomac;
	for (;;) {
		c= p[-1];                          tmac1(c,b0);
		i= *p++; if (!isid(i)) goto endid; tmac1(i,b1); tmac2(c,i,0);
		c= *p++; if (!isid(c)) goto endid; tmac1(c,b2); tmac2(i,c,1);
		i= *p++; if (!isid(i)) goto endid; tmac1(i,b3); tmac2(c,i,2);
		c= *p++; if (!isid(c)) goto endid; tmac1(c,b4); tmac2(i,c,3);
		i= *p++; if (!isid(i)) goto endid; tmac1(i,b5); tmac2(c,i,4);
		c= *p++; if (!isid(c)) goto endid; tmac1(c,b6); tmac2(i,c,5);
		i= *p++; if (!isid(i)) goto endid; tmac1(i,b7); tmac2(c,i,6);
		                                                tmac2(i,0,7);
		while (isid(*p++));
		if (eob(--p)) {refill(p); p=inp+1; continue;}
		goto lokid;
	endid:
		if (eob(--p)) {refill(p); p=inp+1; continue;}
		tmac2(p[-1],0,-1+(p-inp));
	lokid:
		slookup(inp,p,0); if (newp) {p=newp; goto again;}
		else break;
	nomac:
		while (isid(*p++));
		if (eob(--p)) {p=refill(p); goto nomac;}
		else break;
	} break;
	} /* end of switch */
	
	if (isslo) return(p);
} /* end of infinite loop */
}

char *
skipbl(p) register char *p; {/* get next non-blank token */
	do {outp=inp=p; p=cotoken(p);} while ((toktyp+COFF)[*inp]==BLANK);
	return(p);
}

char *
unfill(p) register char *p; {
/* take <= BUFSIZ chars from right end of buffer and put them on instack .
/* slide rest of buffer to the right, update pointers, return new p.
*/
	register char *np,*op; register int d;
	if (mactop>=MAXFRE) {
		pperror("%s: too much pushback",macnam);
		p=inp=pend; dump();	/* begin flushing pushback */
		while (mactop>inctop[ifno]) {p=refill(p); p=inp=pend; dump();}
	}
	if (fretop>0) np=bufstack[--fretop];
	else {
		np=savch; savch+=BUFSIZ;
		if (savch>=sbf+SBSIZE) {pperror("no space"); exit(exfail);}
		*savch++='\0';
	}
	instack[mactop]=np; op=pend-BUFSIZ; if (op<p) op=p;
	for (;;) {while (*np++= *op++); if (eob(op)) break;} /* out with old */
	endbuf[mactop++]=np;	/* mark end of saved text */
	np=pbuf+BUFSIZ; op=pend-BUFSIZ; pend=np; if (op<p) op=p;
	while (outp<op) *--np= *--op; /* slide over new */
	if (bob(np)) pperror("token too long");
	d=np-outp; outp+=d; inp+=d; macdam+=d; return(p+d);
}

char *
doincl(p) register char *p; {
	int filok,inctype;
	register char *cp; char **dirp,*nfil; char filname[BUFSIZ];

	p=skipbl(p); cp=filname;
	if (*inp++=='<') {/* special <> syntax */
		inctype=1;
		for (;;) {
			outp=inp=p; p=cotoken(p);
			if (*inp=='\n') {--p; *cp='\0'; break;}
			if (*inp=='>') {      *cp='\0'; break;}
# ifdef gimpel
			if (*inp=='.' && !intss()) *inp='#';
# endif
			while (inp<p) *cp++= *inp++;
		}
	} else if (inp[-1]=='"') {/* regular "" syntax */
		inctype=0;
# ifdef gimpel
		while (inp<p) {if (*inp=='.' && !intss()) *inp='#'; *cp++= *inp++;}
# else
		while (inp<p) *cp++= *inp++;
# endif
		if (*--cp=='"') *cp='\0';
	} else {pperror("bad include syntax",0); inctype=2;}
	/* flush current file to \n , then write \n */
	++flslvl; do {outp=inp=p; p=cotoken(p);} while (*inp!='\n'); --flslvl;
	inp=p; dump(); if (inctype==2) return(p);
	/* look for included file */
	if (ifno+1 >=MAXINC) {
		pperror("Unreasonable include nesting",0); return(p);
	}
	if((nfil=savch)>sbf+SBSIZE-BUFSIZ) {pperror("no space"); exit(exfail);}
	filok=0;
	for (dirp=dirs+inctype; *dirp; ++dirp) {
		if (
# if gcos
			strdex(filname, '/')
# else
			filname[0]=='/' 
# endif
				|| **dirp=='\0') strcpy(nfil,filname);
		else {
			strcpy(nfil,*dirp);
# if unix || gcos
			strcat(nfil,"/");
# endif
#ifdef ibm
#ifndef gimpel
			strcat(nfil,".");
#endif
#endif
			strcat(nfil,filname);
		}
		if (0<(fins[ifno+1]=open(nfil,READ))) {
			filok=1; fin=fins[++ifno]; break;
		}
	}
	if (filok==0) pperror("Can't find include file %s",filname);
	else {
		lineno[ifno]=1; fnames[ifno]=cp=nfil; while (*cp++); savch=cp;
		dirnams[ifno]=dirs[0]=trmdir(copy(nfil));
		sayline();
		/* save current contents of buffer */
		while (!eob(p)) p=unfill(p);
		inctop[ifno]=mactop;
	}
	return(p);
}

equfrm(a,p1,p2) register char *a,*p1,*p2; {
	register char c; int flag;
	c= *p2; *p2='\0';
	flag=strcmp(a,p1); *p2=c; return(flag==SAME);
}

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

	if (savch>sbf+SBSIZE-BUFSIZ) {pperror("too much defining"); return(p);}
	oldsavch=savch; /* to reclaim space if redefinition */
	++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); return(p);
	}
	np=slookup(pin,p,1);
	if (oldval=np->value) savch=oldsavch;	/* 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 ((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.
	*/
	oldsavch=psav=savch;
	for (;;) {/* accumulate definition until linefeed */
		outp=inp=p; p=cotoken(p); pin=inp;
		if (*pin=='\\' && pin[1]=='\n') 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,oldsavch)) {/* redefinition different from old */
			--lineno[ifno]; ppwarn("%s redefined",np->name); ++lineno[ifno];
			np->value=psav-1;
		} else psav=oldsavch; /* identical redef.; reclaim space */
	} else np->value=psav-1;
	--flslvl; inp=pin; savch=psav; return(p);
}

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

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==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 && np->value==0) ++trulvl;
		else ++flslvl;
	} else if (np==ifdloc) {/* ifdef */
		++flslvl; p=skipbl(p); np=slookup(inp,p,0); --flslvl;
		if (flslvl==0 && np->value!=0) ++trulvl;
		else ++flslvl;
	} else if (np==eifloc) {/* endif */
		if (flslvl) {if (--flslvl==0) sayline();}
		else if (trulvl) --trulvl;
		else pperror("If-less endif",0);
	} else if (np==elsloc) {/* else */
		if (flslvl) {
			if (--flslvl!=0) ++flslvl;
			else {++trulvl; sayline();}
		}
		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) ++trulvl; else ++flslvl;
#else
		newp=p;
		if (flslvl==0 && yyparse()) ++trulvl; else ++flslvl;
		p=newp;
#endif
	} else if (np==lneloc) {/* line */
		if (flslvl==0 && pflag==0) {
			outp=inp=p; *--outp='#'; while (*inp!='\n') p=cotoken(p);
			continue;
		}
	} 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;
}
}

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

	/* make definition look exactly like end of #define line */