[PATCH 2/2] remote.c, QCatchSyscalls: Build std::string instead of unique_xmalloc_ptr (Re: [RFA 4/6] Simple cleanup removals in remote.c)

[Simon Marchi]

On 2017-10-16 19:38, Pedro Alves wrote:
> diff --git a/gdb/remote.c b/gdb/remote.c
> index 6b77a9f..a6cb724 100644
> --- a/gdb/remote.c
> +++ b/gdb/remote.c
> @@ -2086,40 +2086,32 @@ remote_set_syscall_catchpoint (struct 
> target_ops *self,
>  			  pid, needed, any_count, n_sysno);
>      }
> 
> -  gdb::unique_xmalloc_ptr<char> built_packet;
> +  std::string built_packet;
>    if (needed)
>      {
>        /* Prepare a packet with the sysno list, assuming max 8+1
>  	 characters for a sysno.  If the resulting packet size is too
>  	 big, fallback on the non-selective packet.  */
>        const int maxpktsz = strlen ("QCatchSyscalls:1") + n_sysno * 9 + 
> 1;
> -
> -      built_packet.reset ((char *) xmalloc (maxpktsz));
> -      strcpy (built_packet.get (), "QCatchSyscalls:1");
> +      built_packet.reserve (maxpktsz);
> +      built_packet = "QCatchSyscalls:1";
>        if (!any_count)
>  	{
> -	  int i;
> -	  char *p;
> -
> -	  p = built_packet.get ();
> -	  p += strlen (p);
> -
>  	  /* Add in catch_packet each syscall to be caught (table[i] != 0).  
> */
> -	  for (i = 0; i < table_size; i++)
> +	  for (int i = 0; i < table_size; i++)
>  	    {
>  	      if (table[i] != 0)
> -		p += xsnprintf (p, built_packet.get () + maxpktsz - p,
> -				";%x", i);
> +		string_appendf (built_packet, ";%x", i);
>  	    }
>  	}
> -      if (strlen (built_packet.get ()) > get_remote_packet_size ())
> +      if (built_packet.size () > get_remote_packet_size ())
>  	{
>  	  /* catch_packet too big.  Fallback to less efficient
>  	     non selective mode, with GDB doing the filtering.  */
>  	  catch_packet = "QCatchSyscalls:1";
>  	}
>        else
> -	catch_packet = built_packet.get ();
> +	catch_packet = built_packet.c_str ();

You can get rid of built_packet, and make catch_packet the std::string.  
And then this last else branch can be removed.

Simon