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From: Keith Thompson <kst-u@mib.org>
Newsgroups: comp.lang.c
Subject: Re: Warning: assignment from incompatible pointer type
Date: Thu, 22 Jun 2017 12:28:18 -0700
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Richard Heathfield <rjh@cpax.org.uk> writes:
> On 22/06/17 19:41, David Brown wrote:
>> On 22/06/17 19:26, bartc wrote:
>>> On 22/06/2017 18:21, Keith Thompson wrote:
>
> <snip>
>
>>>> As you know, the signedness of plain char is implementation-defined.
>>>
>>> But IME it tends to be signed.
>>
>> On x86 it is usually signed.  On other targets, it can be different.
>
> On IBM mainframe systems (eg MVS), it is often unsigned. (I /think/ it's 
> always unsigned on systems that use EBCDIC, but I don't know for sure, 
> so I'll stick to 'often' for now.)

Assuming CHAR_BIT==8 (and I seriously doubt that an EBCDIC-based
implementation would have CHAR_BIT>8), plain char has to be unsigned
in an EBCDIC implementation.

6.2.5p3: "If a member of the basic execution character set is stored
in a char object, its value is guaranteed to be nonnegative."
Most members of the basic execution character set, including all
the letters and digits, have EBCDIC codes exceeding 127.

[...]

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"