Re: [Autogen-users] 5.16.1 make check failure

[Bruce K. <bru...@gm...>]

Hi Dave,

You missed the point.  I do not want two functions:
  char const * fnc(char const * in)
as well as
  char * fnnc(char * in)
any more than libc wants two flavors of strstr(), for example.
So strstr() returns char * and it is up to the caller to be careful.
Perhaps the right thing is to pound the const-ness out of the
pointer inside the function instead of the wrapper, but that is
not the way I grew up all those years ago.

Instead, I'll cast it thus, beit in the function or macro:
   (char *)(uintptr_t)const_str_ptr

On Mon, Jun 18, 2012 at 11:39 AM, Dave Hart
<dav...@da...> wrote:
>  A void * cast would suffer the same warning.  If
> spn_ag_char_map_chars() accepts both const char * and char *
> arguments, the correct argument prototype is const char *.  It is safe
> to cast char * to const char *, but the reverse is not true

The returned result must be assignment compatible with the provided argument.
If the provided argument is not const, then the result is not const.

> I wish I understood why newer gcc isn't warning in the same situation
> -- but I believe it's wrong, as any stripping of const potentially
> violates the const contract (potentially because the consumers of
> de-consted pointers may not in fact write).

Then a convenient solution for the strstr class of functions needs to
be considered.
(Where the attribute of the result matches whatever was provided.)