Re: [Gnu-arch-users] hackerlab, tla, and `char' signedness

[Ludovic Courtès]

Hi,

Andy Tai <address@hidden> writes:

> I have reservations about this...  while these warnings (also seen on x86)
> from gcc 4 are indications of possible problems, I am not sure in eacn case
> the intention of people when using char mean they are unsigned.
> This may have other unseen consequences.  Maybe it is better to go to the code
> and fix the warnings.

To summarize:

1. `unsigned char', `signed char', and `char' are all different, even
   though `char' ``usually'' (meaning that this is
   implementation-dependent, unspecified behavior) behaves as one of the
   two others;

2. the type of literal strings is `char *'.

Therefore, suppose you have:

  extern int str_casecmp (const t_uchar * a, const t_uchar * b);

Passing a literal string to `str_casecmp ()' will raise a warning.
Fixing it in the code would require casting each and every literal
string to `t_uchar *', which is not reasonable.  I'm sure you'll agree.
;-)

I don't think passing `-funsigned-char' is likely to have undesired
consequences since currently `char' is (wrongfully) assumed to be
`unsigned'.

Thanks,
Ludovic.