cpp.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

char *
refill(p) register char *p; {
/* dump buffer.  save chars from inp to p.  read into buffer at pbuf,
/* contiguous with p.  update pointers, return new p.
*/
	register char *np,*op; register int ninbuf;
	dump(); np=pbuf-(p-inp); op=inp;
	if (bob(np+1)) {pperror("token too long"); np=pbeg; p=inp+BUFSIZ;}
	macdam += np-inp; outp=inp=np;
	while (op<p) *np++= *op++;
	p=np;
	for (;;) {
		if (mactop>inctop[ifno]) {/* retrieve hunk of pushed-back macro text */
			op=instack[--mactop]; np=pbuf;
			do {while (*np++= *op++);} while (op<endbuf[mactop]); pend=np-1;
			/* make buffer space avail for 'include' processing */
			if (fretop<MAXFRE) bufstack[fretop++]=instack[mactop];
			return(p);
		} else {/* get more text from file(s) */
			maclvl=0;
			if (0<(ninbuf=read(fin,pbuf,BUFSIZ))) {
				pend=pbuf+ninbuf; *pend='\0';
				return(p);
			}
			/* end of #include file */
			if (ifno==0) {/* end of input */
				if (plvl!=0) {
					int n=plvl,tlin=lineno[ifno]; char *tfil=fnames[ifno];
					lineno[ifno]=maclin; fnames[ifno]=macfil;
					pperror("%s: unterminated macro call",macnam);
					lineno[ifno]=tlin; fnames[ifno]=tfil;
					np=p; *np++='\n';	/* shut off unterminated quoted string */
					while (--n>=0) *np++=')';	/* supply missing parens */
					pend=np; *np='\0'; if (plvl<0) plvl=0;
					return(p);
				}
				if (trulvl || flslvl)
					if (incomment)
						pperror("unterminated comment");
					else
						pperror("missing endif");
				inp=p; dump(); exit(exfail);
			}
			close(fin); fin=fins[--ifno]; dirs[0]=dirnams[ifno]; sayline(BACK);
		}
	}
}

#define BEG 0
#define LF 1

char *
cotoken(p) register char *p; {
	register int c,i; char quoc;
	static int state = BEG;

	if (state!=BEG) goto prevlf;
for (;;) {
again:
	while (!isspc(*p++));
	switch (*(inp=p-1)) {
	case 0: {
		if (eob(--p)) {p=refill(p); goto again;}
		else ++p; /* ignore null byte */
	} break;
	case '|': case '&': for (;;) {/* sloscan only */
		if (*p++== *inp) break;
		if (eob(--p)) p=refill(p);
		else break;
	} break;
	case '=': case '!': for (;;) {/* sloscan only */
		if (*p++=='=') break;
		if (eob(--p)) p=refill(p);
		else break;
	} break;
	case '<': case '>': for (;;) {/* sloscan only */
		if (*p++=='=' || p[-2]==p[-1]) break;
		if (eob(--p)) p=refill(p);
		else break;
	} break;
	case '\\': for (;;) {
		if (*p++=='\n') {++lineno[ifno]; break;}
		if (eob(--p)) p=refill(p);
		else {++p; break;}
	} break;
	case '/': 
	  for (;;) {
		if (*p=='/' && eolcom) {
			p++;
			incomment++;
			if (!passcom) {inp=p-2; dump(); ++flslvl;}
			for (;;) {
				while (*p && *p++ != '\n');
				if (p[-1]=='\n') {
					p--;
					goto endcpluscom;
				} else if (eob(--p)) {
					if(!passcom) {inp=p; p=refill(p);}
					else if ((p-inp) >= BUFSIZ) {/* split long comment */
						inp=p; refill(p);
					} else p=refill(p);
				} else p+=2; /* jlr012 ignore null byte */
			}
		endcpluscom:
			if (!passcom) {outp=inp=p; --flslvl;}
			incomment--;
			goto prevlf; /* AR's "newline"->++lineno jlr009 */
			break;
		}
		else if (*p++=='*') {	/* C style comment */
			incomment++;
			if (!passcom) {inp=p-2; dump(); ++flslvl;}
			for (;;) {
				while (!iscom(*p++));
				if (p[-1]=='*') for (;;) {
					if (*p++=='/') goto endcom;
					if (eob(--p)) {
						if (!passcom) {inp=p; p=refill(p);}
						else if ((p-inp)>=BUFSIZ) {/* split long comment */
							inp=p; p=refill(p);	/* last char written is '*' */
							cputc('/',fout);	/* terminate first part */
							/* 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);
						cputc('*',fout); cputc('/',fout);
						outp=inp=p-=2; *p++='/'; *p++='*';
					} else p=refill(p);
				} else ++p; /* ignore null byte */
			}
		endcom:
			incomment--;
			if (!passcom) {outp=inp=p; --flslvl; goto again;}
			break;
		}
		if (eob(--p)) p=refill(p);
		else break;
	} break;
	  /* 3-9-88 LFL */
	  /* Handle pascal comments if appropriate */
	case '(':
	  if (*p != '*') break;
	  /* else fallthrough */
	case '{':
	  if (!pascal_file) break;
	  /* LFL 6-19-88 */
	  if (flslvl) break;	/* Don't bother with comments after #if 0 */
	  if (p[-1] == '{') --p;
	  incomment++;
	  if (!passcom) {
	    *inp++=' ';		/* 8-4-88 LFL - Hack to handle const{}a=1; */
	    dump();
	    ++flslvl;
	  }
	  for (;;) {		/* Loop until out of comment */
	    ++p;
	    if eob(p) {
	      if (!passcom)
		inp = p;
	      p = refill(p);
	    }
	    if (*p=='}')
	      break;
	    if (*p=='*') {
	      if (eob(++p)) {
		if (!passcom)
		  inp = p;
		p = refill(p);
	      }
	      if (*p==')')
		break;
	      else
		--p;		/* Undo eob(++p) LFL 6-19-88 */
	    }
	    if (*p == '\n') {
	      ++lineno[ifno];
	      putc('\n',fout);
	    }
	  }
	  if (eob(++p)) {
	    if (!passcom) 
	      inp = p;
	    p = refill(p);
	  }
	  incomment--;
	  if (!passcom) {
	    outp=inp=p;
	    flslvl--;
	  }
	  goto again;
	  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': {
/* newline: jlr009 -- not needed with fix to AR's code */
		++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 (*(p-1) == '.') {
                        if (*p == '.'){ p++; break;}
                     }                         
                }
		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=malloc(BUFSIZ+1);
		if (np==NULL) {pperror("no space"); exit(exfail);}
		np[BUFSIZ]='\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; {
	register int filok,inctype;
	register char *cp; register char **dirp,*nfil; char filname[BUFSIZ];

	p=skipbl(p); cp=filname;
	if (*inp++=='<') {/* special <> syntax */
		inctype=1;
		++flslvl;	/* prevent macro expansion */
		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++;
		}
		--flslvl;	/* reenable macro expansion */
	} 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=malloc(BUFSIZ))==NULL) {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);free(nfil);}
	else {
		nfil=realloc(nfil,strlen(nfil)+1);
		lineno[ifno]=1; fnames[ifno]=nfil;
		dirnams[ifno]=dirs[0]=trmdir(copy(nfil));
		sayline(START);
		/* 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; register int flag;
	c= *p2; *p2='\0';
	flag=strcmp(a,p1); *p2=c; return(flag==SAME);

}

char *
dopragma(p)   /* process '#pragma' */
   char *p;