[[C++ PATCH]] Implement C++2a P0330R2 - Literal Suffixes for ptrdiff_t and size_t

[Jakub Jelinek]

On Mon, Feb 01, 2021 at 01:46:13PM -0500, Ed Smith-Rowland wrote:
> @@ -0,0 +1,8 @@
> +// { dg-do compile { target c++23 } }
> +
> +#include <cstddef>
> +#include <type_traits>
> +
> +static_assert(std::is_same_v<decltype(123zu), std::size_t>);
> +static_assert(std::is_same_v<decltype(456z), std::ptrdiff_t>);

Shouldn't this be std::make_signed<std::size_t>::type instead of std::ptrdiff_t

> +std::ptrdiff_t pd1 = 1234z; // { dg-warning "use of C\+\+23 ptrdiff_t integer constant" "" { target c++20_down } }
> +std::ptrdiff_t PD1 = 5678Z; // { dg-warning "use of C\+\+23 ptrdiff_t integer constant" "" { target c++20_down } }

Ditto here.

> +	  const char *message = (result & CPP_N_UNSIGNED) == CPP_N_UNSIGNED
> +				? N_("use of C++23 size_t integer constant")
> +				: N_("use of C++23 ptrdiff_t integer constant");

And here too (perhaps %<make_signed<size_t>::type%> )?
And maybe %<size_t%> too.

> --- a/libcpp/include/cpplib.h
> +++ b/libcpp/include/cpplib.h
> @@ -500,6 +500,9 @@ struct cpp_options
>    /* Nonzero means tokenize C++20 module directives.  */
>    unsigned char module_directives;
>  
> +  /* Nonzero for C++23 ptrdiff_t and size_t literals.  */

And drop "ptrdiff_t and " here?

> +#define CPP_N_SIZE_T	0x2000000 /* C++23 size_t or ptrdiff_t literal  */

And " or ptrdiff_t" here?

While ptrdiff_t will usually be the same type, seems there is e.g.:
config/darwin.h:#define SIZE_TYPE "long unsigned int"
config/darwin.h:#define PTRDIFF_TYPE "int"
config/i386/djgpp.h:#define SIZE_TYPE "long unsigned int"
config/i386/djgpp.h:#define PTRDIFF_TYPE "int"
config/m32c/m32c.h:#define PTRDIFF_TYPE (TARGET_A16 ? "int" : "long int")
config/m32c/m32c.h:#define SIZE_TYPE "unsigned int"
config/rs6000/rs6000.h:#define PTRDIFF_TYPE "int"
config/rs6000/rs6000.h:#define SIZE_TYPE "long unsigned int"
config/s390/linux.h:#define SIZE_TYPE "long unsigned int"
config/s390/linux.h:#define PTRDIFF_TYPE (TARGET_64BIT ? "long int" : "int")
config/visium/visium.h:#define SIZE_TYPE "unsigned int"
config/visium/visium.h:#define PTRDIFF_TYPE "long int"
config/vms/vms.h:#define SIZE_TYPE  "unsigned int"
config/vms/vms.h:#define PTRDIFF_TYPE (flag_vms_pointer_size == VMS_POINTER_SIZE_NONE ? \
config/vms/vms.h-                      "int" : "long long int")
so quite a few differences.

	Jakub