[TUHS] origins of void* -- Apology!

Steffen Nurpmeso steffen at sdaoden.eu
Thu Nov 9 09:33:21 AEST 2017


Warner Losh <imp at bsdimp.com> wrote:
 |On Wed, Nov 8, 2017 at 9:07 AM, Nemo <[1]cym224 at gmail.com[/1]> wrote:
 |On 6 November 2017 at 19:36, Ron Natalie <[2]ron at ronnatalie.com[/2]> wrote:
 |> It’s worse than that.   “char” is defined as neither signed nor unsigned.
 |> The signedness is implementation defined.    This was why we have \
 |> the inane
 |> “signed” keyword.
 ...
 |What was that story about porting an early UNIX to a machine with
 |different char polarity?  I dimly recall only a few problems.
 |
 |Doesn't even have to be very early... There's lots of 'assume char \
 |is signed bugs' in even modern code. So many that ARM gave up on the \
 |idea that 
 |unsigned char was good (since the underlying ARM architecture supported \
 |it better) and their modern ABIs are all signed char. The other thing \
 ..
 |When I was working on FreeBSD/arm only a decade ago, I'd routinely \
 |hit both of these issues...

I had one of those on Debian/arm64 (Bug#806300) no sooner but
November 2015, very friendly reported as

 |This symptom and the pattern of failures is typical of programs that
 |assume that plain char is signed. Fortunately there's a warning in
 |the build log that tells you exactly where the bug is:

(in fact already mentioned in some hidden archlinux forum, and
also to me in private by a Swede, but i failed to see, and forgot,
hu-hu!!, all in March 2015) introduced in December 2013 when
blindly fixing CC warnings (Many: fix gcc 4.8.2 -fstrict-overflow
-Wstrict-overflow=5).  Testing char not int against EOF is bad.

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)


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