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Path: utzoo!mnetor!seismo!ut-sally!pyramid!decwrl!sun!guy
From: guy@sun.uucp (Guy Harris)
Newsgroups: net.bugs.4bsd
Subject: Some "lex" cleanups and bug fixes
Message-ID: <5669@sun.uucp>
Date: Wed, 30-Jul-86 17:16:14 EDT
Article-I.D.: sun.5669
Posted: Wed Jul 30 17:16:14 1986
Date-Received: Thu, 31-Jul-86 21:43:40 EDT
Distribution: net
Organization: Sun Microsystems, Inc.
Lines: 302

Index:	usr.bin/lex/lmain.c usr.bin/lex/sub1.c usr.bin/lex/parser.y 4.3BSD

Description:
	1) A couple of bits of code here are really sloppy when it comes
	   to pointers vs. integers.

	2) Some other bits of code are sloppy when it comes to - surprise! -
	   dereferencing NULL pointers.
Repeat-By:
	Try "lex -Q anything.l", or "lex </dev/null" (if "lex" isn't
	given a source file, it reads from standard input) if your
	machine dumps core when dereferencing null pointers.
Fix:
	See following context diffs.  (Yes, I know it says "4.3beta".
	"lex" hasn't changed since then.)

*** /archwizard/4.3beta/usr/src/usr.bin/lex/lmain.c	Thu Feb 21 13:35:28 1985
--- ./lmain.c	Thu Jan  2 14:02:45 1986
***************
*** 128,134
  dp =	dchar = myalloc(DEFCHAR,sizeof(*dchar));
  	sname = (char **) myalloc(STARTSIZE,sizeof(*sname));
  sp = 	schar = myalloc(STARTCHAR,sizeof(*schar));
! 	if(ccl == 0 || def == 0 || subs == 0 || dchar == 0 || sname == 0 || schar == 0)
  		error("Too little core to begin");
  	}
  free1core(){

--- 128,134 -----
  dp =	dchar = myalloc(DEFCHAR,sizeof(*dchar));
  	sname = (char **) myalloc(STARTSIZE,sizeof(*sname));
  sp = 	schar = myalloc(STARTCHAR,sizeof(*schar));
! 	if(ccl == 0 || pchar == 0 || def == 0 || subs == 0 || dchar == 0 || sname == 0 || schar == 0)
  		error("Too little core to begin");
  	}
  free1core(){
***************
*** 194,199
    int a,b; {
  	register char *i;
  	i = calloc(a, b);
  	if(i==0)
  		warning("OOPS - calloc returns a 0");
  	else if(i == (char *)-1){

--- 194,200 -----
    int a,b; {
  	register char *i;
  	i = calloc(a, b);
+ # ifdef DEBUG
  	if(i==0)
  		warning("OOPS - calloc returns a 0");
  # endif
***************
*** 196,204
  	i = calloc(a, b);
  	if(i==0)
  		warning("OOPS - calloc returns a 0");
- 	else if(i == (char *)-1){
- # ifdef DEBUG
- 		warning("calloc returns a -1");
  # endif
  		return(0);
  		}

--- 197,202 -----
  # ifdef DEBUG
  	if(i==0)
  		warning("OOPS - calloc returns a 0");
  # endif
  	return(i);
  	}
***************
*** 200,207
  # ifdef DEBUG
  		warning("calloc returns a -1");
  # endif
- 		return(0);
- 		}
  	return(i);
  	}
  # ifdef DEBUG

--- 198,203 -----
  	if(i==0)
  		warning("OOPS - calloc returns a 0");
  # endif
  	return(i);
  	}
  # ifdef DEBUG
***************
*** 207,213
  # ifdef DEBUG
  buserr(){
  	fflush(errorf);
! 	fflush(fout);
  	fflush(stdout);
  	fprintf(errorf,"Bus error\n");
  	if(report == 1)statistics();

--- 203,210 -----
  # ifdef DEBUG
  buserr(){
  	fflush(errorf);
! 	if(fout != NULL)
! 		fflush(fout);
  	fflush(stdout);
  	fprintf(errorf,"Bus error\n");
  	if(report == 1)statistics();
***************
*** 215,221
  	}
  segviol(){
  	fflush(errorf);
! 	fflush(fout);
  	fflush(stdout);
  	fprintf(errorf,"Segmentation violation\n");
  	if(report == 1)statistics();

--- 212,219 -----
  	}
  segviol(){
  	fflush(errorf);
! 	if(fout != NULL)
! 		fflush(fout);
  	fflush(stdout);
  	fprintf(errorf,"Segmentation violation\n");
  	if(report == 1)statistics();

*** /archwizard/4.3beta/usr/src/usr.bin/lex/sub1.c	Thu Feb 21 13:34:53 1985
--- ./sub1.c	Thu Jan  2 14:05:09 1986
***************
*** 62,68
  	fprintf(errorf,s,p,d);
  	putc('\n',errorf);
  	fflush(errorf);
! 	fflush(fout);
  	fflush(stdout);
  	}
  index(a,s)

--- 62,69 -----
  	fprintf(errorf,s,p,d);
  	putc('\n',errorf);
  	fflush(errorf);
! 	if(fout != NULL)
! 		fflush(fout);
  	fflush(stdout);
  	}
  index(a,s)

*** /archwizard/4.3beta/usr/src/usr.bin/lex/parser.y	Mon Jan 13 15:33:13 1986
--- ./parser.y	Mon Jan 13 15:19:36 1986
***************
*** 216,222
  yylex(){
  	register char *p;
  	register int c, i;
! 	char  *t, *xp;
  	int n, j, k, x;
  	static int sectbegin;
  	static char token[TOKENSIZE];

--- 216,223 -----
  yylex(){
  	register char *p;
  	register int c, i;
! 	char  *t;
! 	register char *xp;
  	int n, j, k, x;
  	static int sectbegin;
  	static char token[TOKENSIZE];
***************
*** 241,248
  						sectbegin = TRUE;
  						i = treesize*(sizeof(*name)+sizeof(*left)+
  							sizeof(*right)+sizeof(*nullstr)+sizeof(*parent))+ALITTLEEXTRA;
! 						c = myalloc(i,1);
! 						if(c == 0)
  							error("Too little core for parse tree");
  						p = c;
  						cfree(p,i,1);

--- 242,249 -----
  						sectbegin = TRUE;
  						i = treesize*(sizeof(*name)+sizeof(*left)+
  							sizeof(*right)+sizeof(*nullstr)+sizeof(*parent))+ALITTLEEXTRA;
! 						xp = myalloc(i,1);
! 						if(xp == 0)
  							error("Too little core for parse tree");
  						cfree((char *)xp,i,1);
  						name = (int *)myalloc(treesize,sizeof(*name));
***************
*** 244,254
  						c = myalloc(i,1);
  						if(c == 0)
  							error("Too little core for parse tree");
! 						p = c;
! 						cfree(p,i,1);
! 						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));
  						if(name == 0 || left == 0 || right == 0 || parent == 0 || nullstr == 0)

--- 245,254 -----
  						xp = myalloc(i,1);
  						if(xp == 0)
  							error("Too little core for parse tree");
! 						cfree((char *)xp,i,1);
! 						name = (int *)myalloc(treesize,sizeof(*name));
! 						left = (int *)myalloc(treesize,sizeof(*left));
! 						right = (int *)myalloc(treesize,sizeof(*right));
  						nullstr = myalloc(treesize,sizeof(*nullstr));
  						parent = (int *)myalloc(treesize,sizeof(*parent));
  						if(name == 0 || left == 0 || right == 0 || parent == 0 || nullstr == 0)
***************
*** 250,256
  						left = myalloc(treesize,sizeof(*left));
  						right = myalloc(treesize,sizeof(*right));
  						nullstr = myalloc(treesize,sizeof(*nullstr));
! 						parent = myalloc(treesize,sizeof(*parent));
  						if(name == 0 || left == 0 || right == 0 || parent == 0 || nullstr == 0)
  							error("Too little core for parse tree");
  						return(freturn(DELIM));

--- 250,256 -----
  						left = (int *)myalloc(treesize,sizeof(*left));
  						right = (int *)myalloc(treesize,sizeof(*right));
  						nullstr = myalloc(treesize,sizeof(*nullstr));
! 						parent = (int *)myalloc(treesize,sizeof(*parent));
  						if(name == 0 || left == 0 || right == 0 || parent == 0 || nullstr == 0)
  							error("Too little core for parse tree");
  						return(freturn(DELIM));
***************
*** 294,300
  					case 'k': case 'K': /* overriden packed char classes */
  						while (*p && !digit(*p))p++;
  						if (report==2) report=1;
! 						cfree(pchar, pchlen, sizeof(*pchar));
  						pchlen = siconv(p);
  # ifdef DEBUG
  						if (debug) printf( "Size classes (%%k) now %d\n",pchlen);

--- 294,300 -----
  					case 'k': case 'K': /* overriden packed char classes */
  						while (*p && !digit(*p))p++;
  						if (report==2) report=1;
! 						cfree((char *)pchar, pchlen, sizeof(*pchar));
  						pchlen = siconv(p);
  # ifdef DEBUG
  						if (debug) printf( "Size classes (%%k) now %d\n",pchlen);
***************
*** 419,424
  		/* end of section one processing */
  		}
  	else if(sect == RULESECTION){		/* rules and actions */
  		while(!eof){
  			switch(c=gch()){
  			case '\0':

--- 419,430 -----
  		/* end of section one processing */
  		}
  	else if(sect == RULESECTION){		/* rules and actions */
+ 		/*
+ 		 * If it is required that one of the items given above
+ 		 * which causes a call to "lgate" must have been called
+ 		 * by now, this should be an error instead.
+ 		 */
+ 		lgate();
  		while(!eof){
  			switch(c=gch()){
  			case '\0':
***************
*** 678,683
  			}
  		}
  	/* section three */
  	ptail();
  # ifdef DEBUG
  	if(debug)

--- 684,696 -----
  			}
  		}
  	/* section three */
+ 	/*
+ 	 * If it is required that one of the items given above
+ 	 * which causes a call to "lgate" must have been called
+ 	 * by now, this should be an error instead.  (If it hasn't
+ 	 * been done by now, do we have a null "lex" program?)
+ 	 */
+ 	lgate();
  	ptail();
  # ifdef DEBUG
  	if(debug)
-- 
	Guy Harris
	{ihnp4, decvax, seismo, decwrl, ...}!sun!guy
	guy@sun.com (or guy@sun.arpa)