Re: [PATCH] Xen: don't warn about 2-byte wchar_t in efi

[Arnd Bergmann]

On Monday 16 May 2016 12:08:17 Stefano Stabellini wrote:
> On Wed, 11 May 2016, Arnd Bergmann wrote:
> > The XEN UEFI code has become available on the ARM architecture
> > recently, but now causes a link-time warning:
> > 
> > ld: warning: drivers/xen/efi.o uses 2-byte wchar_t yet the output is to use 4-byte wchar_t; use of wchar_t values across objects may fail
> > 
> > This seems harmless, because the efi code only uses 2-byte
> > characters when interacting with EFI, so we don't pass on those
> > strings to elsewhere in the system, and we just need to
> > silence the warning.
> > 
> > It is not clear to me whether we actually need to build the file
> > with the -fshort-wchar flag, but if we do, then we should also
> > pass --no-wchar-size-warning to the linker, to avoid the warning.
> > 
> > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> > Fixes: 37060935dc04 ("ARM64: XEN: Add a function to initialize Xen specific UEFI runtime services")
> 
> Given that drivers/xen/efi.c doesn't actually use any wchar_t, it is not
> clear to me whether we need to pass -fshort-wchar either. However this
> patch is correct any, so I committed it to xentip.

Right, I was wondering about that too, but it has been this way since the
code was first merged, so I couldn't figure out if removing the flag
had any side-effects.

	Arnd