Xen: don't warn about 2-byte wchar_t in efi

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@arndb.de>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Fixes: 37060935dc04 ("ARM64: XEN: Add a function to initialize Xen specific UEFI runtime services")

diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index 9b7a35c9e51ddd5a9d3bdb3319cfb9f1a35ff627..030e91b38e32bcf077713e31b7cc56a5a35e5924 100644 (file)
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -8,6 +8,7 @@ nostackp := $(call cc-option, -fno-stack-protector)
 CFLAGS_features.o                      := $(nostackp)
 
 CFLAGS_efi.o                           += -fshort-wchar
+LDFLAGS                                        += $(call ld-option, --no-wchar-size-warning)
 
 dom0-$(CONFIG_PCI) += pci.o
 dom0-$(CONFIG_USB_SUPPORT) += dbgp.o