Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!think!zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!rutgers!att!cbnewsd!jrstu
From: jrstu@cbnewsd.ATT.COM (james.stuhlmacher)
Newsgroups: comp.os.minix
Subject: make(1) keeps on compiling when interrupt is pressed
Message-ID: <12429@cbnewsd.ATT.COM>
Date: 3 Jan 90 03:39:36 GMT
Reply-To: jrstu@cbnewsd.ATT.COM (james.stuhlmacher,ih,)
Organization: AT&T Bell Laboratories
Lines: 76

This is a reposting.

About a month ago I posted an article stating that make(1)
does not quit completely when you press the interrupt key.  It
just stops the one compile and starts the next.  I blamed this on
system(3) that was ignoring the SIGINT signal.  Terrence Holm wrote
me a letter explaining that system(3) should ignore signals in
case you start an interactive shell via it.  He also said that
make(1) should look at the exit status of system(3) to determine
whether it should completely stop or not.

This made sense so I looked at the code for make(1) and it DOES
look at the exit status.  Before I could proceed, Bruce Evans
wrote a letter to me saying its all sh(1)s fault because it does
not return the interrupt status of its interrupted child.  (System(3)
calls "sh -c command".)  Thus sh(1) was returning 0 when it should
have been returning the number of the signal that aborted its child.
System(3) simply passes on the exit status of sh(1) to the program
that called system(3).

Bruce also sent me the patch below to fix the bug.  After looking
through the code, I think this is the correct fix.  This patch has
been redone for v1.5.0.

#! /bin/sh
# This is a shell archive.  Remove anything before this line, then unpack
# it by saving it into a file and typing "sh file".  To overwrite existing
# files, type "sh file -c".  You can also feed this as standard input via
# unshar, or by typing "sh <file", e.g..  If this archive is complete, you
# will see the following message at the end:
#		"End of shell archive."
# Contents:  sh3.cdif
# Wrapped by jims@stu on Tue Jan  2 11:14:54 1990
PATH=/bin:/usr/bin:/usr/ucb ; export PATH
if test -f 'sh3.cdif' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'sh3.cdif'\"
else
echo shar: Extracting \"'sh3.cdif'\" \(343 characters\)
sed "s/^X//" >'sh3.cdif' <<'END_OF_FILE'
X*** osh3.c	Tue Jan  2 10:39:45 1990
X--- nsh3.c	Tue Jan  2 11:06:00 1990
X***************
X*** 509,516 ****
X  			if (canintr)
X  				intr = 0;
X  		}
X! 		else
X! 			onintr();
X  	return(rv);
X  }
X  
X--- 509,519 ----
X  			if (canintr)
X  				intr = 0;
X  		}
X! 		else {
X! 			if (exstat == 0)
X! 				exstat = rv;
X! 			onintr();
X! 		}
X  	return(rv);
X  }
X  
END_OF_FILE
if test 343 -ne `wc -c <'sh3.cdif'`; then
    echo shar: \"'sh3.cdif'\" unpacked with wrong size!
fi
# end of 'sh3.cdif'
fi
echo shar: End of shell archive.
exit 0


Jim Stuhlmacher
j.stuhlmacher@ATT.com
..!att!ihlpb!jims