Re: [PATCH] Canonicalize conversion operators

[Pedro Alves <palves@redhat.com>]

On 10/17/2017 11:12 PM, Keith Seitz wrote:
> Consider a conversion operator such as:
> 
> operator foo const* const* ();
> 
> There are two small parser problems, highlighted by this test:
> 
> (gdb) p operator foo const* const*
> There is no field named operatorfoo const* const *
> 
> GDB is looking up the symbol "operatorfoo const* const*" -- it is missing a
> space between the keyword "operator" and the type name "foo const* const*".
> Pedro also discovered this problem and has a patch for it pending on his
> cxx-breakpoint-improvements branch.
> 
> However, something not address by Pedro's patch is that this input of the
> user-defined type needs to be canonicalized so that different "spellings" of
> the type are recognized:
> 
> (gdb) p operator const foo* const *
> There is no field named operator const foo* const *
> 

Indeed.


> @@ -1630,7 +1630,13 @@ oper:	OPERATOR NEW
>  
>  			  c_print_type ($2, NULL, &buf, -1, 0,
>  					&type_print_raw_options);
> -			  $$ = operator_stoken (buf.c_str ());
> +
> +			  /* This also needs canonicalization.  */
> +			  std::string canon
> +			    = " " + cp_canonicalize_string (buf.c_str ());
> +			  if (canon.length () == 1)
> +			    canon = " " + buf.string ();
> +			  $$ = operator_stoken (canon.c_str ());

The length() == 1 check gave me pause.  It's checking that
cp_canonicalize_string returned empty of course, but it
wasn't super clear on a quick skim.

I think you could write it like this, making that part clearer,
and also saving a few string dups and copies:

			  /* This also needs canonicalization.  */
			  std::string canon
			    = cp_canonicalize_string (buf.c_str ());
			  if (canon.empty ())
			    canon = std::move (buf.string ());
			  $$ = operator_stoken ((" " + canon).c_str ());


>  
> +# Make sure conversion operator names are canonicalized and properly
> +# "spelled."

Period should outside the quote, I think.

Otherwise OK.

Thanks,
Pedro Alves