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Posting-Version: version B 2.10.1 6/24/83; site allegra.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!allegra!jpl
From: jpl@allegra.UUCP (John P. Linderman)
Newsgroups: net.bugs.4bsd,net.unix-wizards
Subject: bug in 4.2 /bin/make
Message-ID: <2728@allegra.UUCP>
Date: Thu, 23-Aug-84 13:03:19 EDT
Article-I.D.: allegra.2728
Posted: Thu Aug 23 13:03:19 1984
Date-Received: Fri, 24-Aug-84 04:44:18 EDT
Organization: AT&T Bell Laboratories, Murray Hill
Lines: 37

SYSNOPSIS:
    make sometimes dumps core with a memory fault or segmentation fault

REPEAT BY:
    Turn the following four lines into a makefile, and run make -nd
	foo:main.o
		cc main.o -o foo

	main.o:a/*.h

    When I do it, I get
	doname(foo,0)
	doname(main.o,1)
	sh: 24665 Memory fault - core dumped
    
    Neither the -n nor the -d are essential to generate the dump.
    The bug seems to depend on the presence of the directory reference
    in the dependency for main.o.

FIX:
    A quick runthrough with a version of make made with -g revealed that
    function expand() in file /usr/src/bin/make/doname.c was being invoked
    with a NULL depname pointer.  I didn't dig into the code to determine
    how the NULL pointer got to expand(), but adding the following check
    to expand() around lines 282-287 eliminates the core dumping and causes
    make to operate correctly.

	--- 282,288 -----
	  char *s1;
	  struct depblock *p, *srchdir();
	  
	+ if (q->depname == NULL) return;
	  s1 = q->depname->namep;
	  for(s=s1 ; ;) switch(*s++)
		{

John P. Linderman  Break Make Department  allegra!jpl