Kbuild: use -fshort-wchar globally

Commit 971a69db7d ("Xen: don't warn about 2-byte wchar_t in efi")
added the --no-wchar-size-warning to the Makefile to avoid this
harmless warning:

arm-linux-gnueabi-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

Changing kbuild to use thin archives instead of recursive linking
unfortunately brings the same warning back during the final link.

The kernel does not use wchar_t string literals at this point, and
xen does not use wchar_t at all (only efi_char16_t), so the flag
has no effect, but as pointed out by Jan Beulich, adding a wchar_t
string literal would be bad here.

Since wchar_t is always defined as u16, independent of the toolchain
default, always passing -fshort-wchar is correct and lets us
remove the Xen specific hack along with fixing the warning.

Link: https://patchwork.kernel.org/patch/9275217/
Fixes: 971a69db7d ("Xen: don't warn about 2-byte wchar_t in efi")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This commit is contained in:
Arnd Bergmann 2017-07-26 15:36:23 +02:00 committed by Masahiro Yamada
parent 4e433fc4d1
commit 8c97023cf0
2 changed files with 1 additions and 4 deletions

View File

@ -396,7 +396,7 @@ LINUXINCLUDE := \
KBUILD_CPPFLAGS := -D__KERNEL__
KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-fno-strict-aliasing -fno-common \
-fno-strict-aliasing -fno-common -fshort-wchar \
-Werror-implicit-function-declaration \
-Wno-format-security \
-std=gnu89 $(call cc-option,-fno-PIE)

View File

@ -7,9 +7,6 @@ obj-y += xenbus/
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_ARM64) += arm-device.o
dom0-$(CONFIG_PCI) += pci.o
dom0-$(CONFIG_USB_SUPPORT) += dbgp.o