Re: bin/50827 (sh -c ': "${x=$((1))}"' gives bogus syntax error)

[Robert Elz <kre%munnari.OZ.AU@localhost>]

The following reply was made to PR bin/50827; it has been noted by GNATS.

From: Robert Elz <kre%munnari.OZ.AU@localhost>
To: Christos Zoulas <christos%zoulas.com@localhost>
Cc: gnats-bugs%NetBSD.org@localhost, gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost,
        rhansen%rhansen.org@localhost
Subject: Re: bin/50827 (sh -c ': "${x=$((1))}"' gives bogus syntax error)
Date: Sun, 21 Feb 2016 08:19:00 +0700

     Date:        Sat, 20 Feb 2016 12:33:30 -0500
     From:        Christos Zoulas <christos%zoulas.com@localhost>
     Message-ID:  <61B42472-7C43-4B93-8185-D902A81727B5%zoulas.com@localhost>
 
   | > wow the 43469 one was giving me trouble for a while!
 
 Don't jump for joy just yet.  The two expressions in the PR both work
 (produce the same, correct, result) but there is potential for much
 other breakage I have not yet tested, plus more variants of the expr
 in question tha also need to work, also yet untested.
 
 So some progress, but too early to open the champaign...
 
 While here I'll ask another question ... the code in sh is sprinkled
 with "volatile" all over the place (particularly in the area I have
 been looking.)   I gather this is to appease gcc wrt setjmp/longmp
 (the FreeBSD code has a comment - or maybe commit log entry - simply
 refusing to go that route...)   Does anyone mind if I strip out most
 of that, and add "just the right" volatile vars, so the trap longjmp
 stuff works (at least in the token reading functions) - or should work,
 modulo whatever nonsense gcc gets up to, and remove it from all the
 rest?  (If I do that I'll make it a separate patch.)   All that (unnecessary)
 volatile nonsense has to be slowing shell execution, and with my fixes,
 it will be even worse.   Until I remove it so I can measure the effect, I
 don't know how much difference it really makes, but ...   And of course,
 nothing will happen there until the substantive changes are all fully
 tested (and corrected if needed.)
 
 kre