Re: [PATCH] gdb/solib: pass lm_info, original_name and name to solib constructor

[Guinevere Larsen <guinevere@redhat.com>]

On 6/3/25 12:32 PM, Simon Marchi wrote:
> diff --git a/gdb/solib-target.c b/gdb/solib-target.c
> index 68dc3cc92c0a..dce90a5f8c8e 100644
> --- a/gdb/solib-target.c
> +++ b/gdb/solib-target.c
> @@ -244,14 +244,7 @@ solib_target_current_sos (void)
>   
>     /* Build a struct solib for each entry on the list.  */
>     for (lm_info_target_up &info : library_list)
> -    {
> -      auto &new_solib = sos.emplace_back ();
> -
> -      /* We don't need a copy of the name in INFO anymore.  */
> -      new_solib.name = std::move (info->name);
> -      new_solib.original_name = new_solib.name;
> -      new_solib.lm_info = std::move (info);
> -    }
> +    sos.emplace_back (std::move (info), info->name, info->name);
This is a bad idea. I double checked with c++ folk and while no 
compilers warn about this, if the compiler evaluates things right to 
left (like gcc) this works, but if they evaluate left to right (like 
clang), then info->name will be de-referencing null and segfault. This 
might also depend on ABI, but the end result is the same: fragile at 
best. we'll need something that saves or moves info->name to pass it to 
the emplace_back constructor
>   
>     return sos;
>   }


-- 
Cheers,
Guinevere Larsen
She/Her/Hers