[PATCH] kbuild, LLVMLinux: Add -Werror to cc-option to support clang

From: Arnd Bergmann
Date: Fri Mar 31 2017 - 16:39:56 EST


From: Mark Charlebois <charlebm@xxxxxxxxx>

Clang will warn about unknown warnings but will not return false
unless -Werror is set. GCC will return false if an unknown
warning is passed.

Adding -Werror make both compiler behave the same.

[arnd: it turns out we need the same patch for testing whether -ffunction-sections
works right with gcc. I've build tested extensively with this patch
applied, so let's just merge this one now.]

Signed-off-by: Mark Charlebois <charlebm@xxxxxxxxx>
Signed-off-by: Behan Webster <behanw@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Jan-Simon MÃller <dl9pf@xxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
scripts/Kbuild.include | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index d6ca649cb0e9..a70fd26204de 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -116,12 +116,12 @@ CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS))
# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)

cc-option = $(call try-run,\
- $(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
+ $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))

# cc-option-yn
# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
cc-option-yn = $(call try-run,\
- $(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
+ $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)

# cc-option-align
# Prefix align with either -falign or -malign
@@ -131,7 +131,7 @@ cc-option-align = $(subst -functions=0,,\
# cc-disable-warning
# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
cc-disable-warning = $(call try-run,\
- $(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
+ $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))

# cc-name
# Expands to either gcc or clang
--
2.9.0