Re: [PATCH] nvptx: Add _ssize_t as _READ_WRITE_RETURN_TYPE in newlib/libc/include/sys/config.h

Hi Arijit!

On 2025-07-17T01:27:41+0530, Arijit Kumar Das <[email protected]> wrote:
> Here's the final commit. I hope it's okay :-)

Almost.  ;-)

> From 3089acec0f3b5606bffcbca3b6864023ccd2afa3 Mon Sep 17 00:00:00 2001
> From: Arijit Kumar Das <[email protected]>
> Date: Thu, 17 Jul 2025 01:01:03 +0530
> Subject: [PATCH] [nvptx]: Use _READ_WRITE_RETURN_TYPE for return type and
>  _READ_WRITE_BUFSIZE_TYPE for count in read() and write()

The important thing about this commit is the changes of types.  I'd say:

    nvptx: Change 'read' and 'write' to 'ssize_t' return type, and 'size_t count'

Your following text is just textually describing the commit:

> - Changed the return type of read() from int to _READ_WRITE_RETURN_TYPE as per conventions.
> - Changed the 'count' parameter of read() and write() to _READ_WRITE_BUFSIZE_TYPE.
> - Defined both of the above macros in libc/include/sys/config.h under __nvptx__.
> - _READ_WRITE_RETURN_TYPE defined as _ssize_t (ssize_t).
> - _READ_WRITE_BUFSIZE_TYPE defined as __size_t (size_t).

..., so I personally wouldn't include that.  Instead, you could add some
rationale, perhaps:

    ... to match their specification in POSIX, and enable large files.

> Signed-off-by: Arijit Kumar Das <[email protected]>
> ---
>  newlib/libc/include/sys/config.h  | 5 +++++
>  newlib/libc/machine/nvptx/misc.c  | 4 ++--
>  newlib/libc/machine/nvptx/write.c | 3 ++-
>  3 files changed, 9 insertions(+), 3 deletions(-)

> --- a/newlib/libc/include/sys/config.h
> +++ b/newlib/libc/include/sys/config.h
> @@ -12,6 +12,11 @@
>  #define __DYNAMIC_REENT__
>  #endif
>  
> +#ifdef __nvptx__
> +#define _READ_WRITE_RETURN_TYPE _ssize_t
> +#define _READ_WRITE_BUFSIZE_TYPE __size_t
> +#endif
> +
>  /* exceptions first */
>  #if defined(__H8500__) || defined(__W65__)
>  #define __SMALL_BITFIELDS

ACK.

But for the following two nvptx-specific implementation files:

> --- a/newlib/libc/machine/nvptx/misc.c
> +++ b/newlib/libc/machine/nvptx/misc.c

> -int
> -read(int fd, void *buf, size_t count) {
> +_READ_WRITE_RETURN_TYPE
> +read(int fd, void *buf, _READ_WRITE_BUFSIZE_TYPE count) {

> --- a/newlib/libc/machine/nvptx/write.c
> +++ b/newlib/libc/machine/nvptx/write.c

> -_READ_WRITE_RETURN_TYPE write (int fd, const void *buf, size_t count)
> +_READ_WRITE_RETURN_TYPE
> +write (int fd, const void *buf, _READ_WRITE_BUFSIZE_TYPE count)
>  {

..., I'd like you to use the actual types.  So, please here replace
'_READ_WRITE_RETURN_TYPE' with 'ssize_t', and revert back
'_READ_WRITE_BUFSIZE_TYPE' to 'size_t'.


Grüße
 Thomas