Re: [PATCH] [gdbsupport] Poison ctype.h / cctype functions

[Tom de Vries <tdevries@suse.de>]

On 3/23/26 3:17 PM, Tom Tromey wrote:
>>>>>> "Tom" == Tom de Vries <tdevries@suse.de> writes:
> 
> Tom> GDB generally uses c_isprint instead of isprint or std::isprint [1].
> Tom> Poison uses of ctype.h / cctype functions in gdbsupport/poison.h.
> 
> Tom> This excludes isupper, islower and toupper because they're currently used in
> Tom> GDB.  Add a fixme to find out whether these exceptions are ok, and if so
> Tom> document why, otherwise fix them.
> 
> Tom> +#define POISON_CCTYPE(F)					\
> Tom> +  template<typename T>						\
> Tom> +  F								\
> Tom> +  {								\
> Tom> +    static_assert (false, "Please use gnulib's c-ctype.h");	\
> Tom> +    return 0;							\
> Tom> +  }
> Tom> +
> Tom> +/* Poisoning of some functions is disabled:
> Tom> +   - isupper, because it's used in ada_decode.
> 
> This is just an oversight.
> 

I've submitted a patch for this ( 
https://sourceware.org/pipermail/gdb-patches/2026-March/226148.html ).

Thanks,
- Tom

> Tom> +   - islower and toupper, because they're used in UNCTRL from readline,
> Tom> +     which is used in tui_redisplay_readline and gdb_fnprint.
> 
> Can't really touch readline but we could write our own UNCTRL variant.
> 
> Tom> +POISON_CCTYPE (int isalnum (T c));
> Tom> +POISON_CCTYPE (int std::isalnum (T c));
> 
> I suspect redefining standard functions like this is not allowed in C++.
> 
> Tom