Re: More problems on HP-UX ... 6

["Andreas Vögele" <voegelas@gmx.net>]

Kevin Ryde writes:

>> According to my copy of "Programming in C" it should be okay to
>> pass a char instead of an int to iscntrl() etc.
>
> I think it was meant to be an int.  But if you're in 7-bit ascii then
> it doesn't make a difference.

Yes, but my German copy of "Programming in C, 2nd ed" says in section 
A.6.1: "A character [...] can be used everywhere in an expression where 
an integer object is required. [...]". And according to section A.7.3, 
subscript array references are expressions.

>> backtrace.c: In function `display_frame_expr':
>> backtrace.c:403: warning: subscript has type `char'
>>
>> numbers.c: In function `mem2uinteger':
>> numbers.c:2337: warning: subscript has type `char'
>> ...
>
> Thanks, I'll add some casts to "int".  They definitely want casts
> through "unsigned char", to protect against 8-bit values.

When I googled for the "subscripts has type char" problem I found a 
statement that says that casts to "int" could "cause problems" on other 
systems. Whatever that means.

Since the build only aborts if --enable-maintainer-mode, i.e. -Werror, 
is enabled I'd probably keep the "char" values. BTW, I use only one 
cast to fix this problem (in backtrace.c). In numbers.c I  changed the 
type of the variables to "int".



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