Re: [PATCH v2 0/3] Inline helpers into Rust without full LTO

[Geert Uytterhoeven]

Hi Arnd,

On Thu, 26 Mar 2026 at 22:34, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> On Thu, Mar 26, 2026, at 16:18, Russell King (Oracle) wrote:
> > On Thu, Mar 26, 2026 at 03:31:26PM +0100, Christian Schrefl wrote:
> >> On 3/26/26 2:47 PM, Miguel Ojeda wrote:
> >> > On Thu, Mar 26, 2026 at 11:10 AM Alice Ryhl <aliceryhl@xxxxxxxxxx> wrote:
> >
> > I'm not sure if this is still true, but I believe it used to be the case
> > that the -linux-gnueabi target has one behaviour for enums (fixed size)
> > whereas -none-eabi, the size of the type depends on the range of values
> > included in the enum.
>
> I checked Debian's arm-none-eabi-gcc, which indeed still has this behavior:
>
> $ echo 'enum { A, B } x = sizeof(x);' | arm-none-eabi-gcc -xc - -O2 -o- -S | grep -A1 x:
> x:
>         .byte   1
>
> and I see the same thing for the hexagon target in clang, but none
> of the other targets that Linux runs on. In particular, clang always
> behaves like linux-gnueabi even when targeting plain eabi.
>
> $ echo 'enum { A, B } x = sizeof(x);' | clang --target=arm-none-eabi -xc - -O2 -o- -S | grep -A1 x:
> x:
>         .long   4
>
> I noticed a similar issue with m68k-linux, which has a bitfield
> alignment different from anything else on gcc, but uses the normal
> behavior on clang.

Ugh, I wasn't aware of that. Adrian, did you know?

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds