Re: [PATCH 5/5] gdbsupport: add path_join function

[Simon Marchi <simon.marchi@polymtl.ca>]

On 2022-04-18 15:09, Pedro Alves wrote:
> On 2022-04-18 19:43, Simon Marchi via Gdb-patches wrote:
>>> One implementation could be:
>>>
>>>     /* The real worker can be compiled in a .cc file if you wish.  */
>>>     extern std::string path_join_1 (std::string a, std::string b);
>>>
>>>     template <typename ...Args)
>>>     std::string
>>>     path_join (std::string a, std::string b, Args... comps)
>>>     {
>>>       return path_join (path_join (a, b), comps...);
>>>     }
>>>
>>>     template <>
>>>     std::string
>>>     path_join (std::string a, std::string b)
>>>     {
>>>       return path_join_1 (a, b);
>>>     }
>>>
>>> I do not pretend this is optimal (it is not).  In this POC I pass all
>>> arguments as std::string and by value, this is probably not what you
>>> want to do in a production grade implementation, but this just gives the
>>> overall idea.
>>>
>>> What do you think?
>> If you can make it work using gdb::string_view or const char *, I think
>> it would be ok.  I'll give it a try.  But otherwise, I am personally
>> fine with the sentinel nullptr, given that the compiler gives you a
>> warning if you forget it.
> 
> I think it would just work as is you replace std::string with const char *
> in Lancelot's snippet above.  FWIW, I had the same thought as Lancelot
> about using variable templates instead of varargs.
> 
> OOC, is there any place in GDB that wants to pass more than two components
> to path_join?  I skimmed the patch and didn't notice one.

I am not aware of one, I'd be happy to make path_join just have two
parameters and be done with it.

Simon