kbuild: enable 'make CFLAGS=...' to add additional options to CC
The variable CFLAGS is a wellknown variable and the usage by
kbuild may result in unexpected behaviour.
On top of that several people over time has asked for a way to
pass in additional flags to gcc.
This patch replace use of CFLAGS with KBUILD_CFLAGS all over the
tree and enabling one to use:
make CFLAGS=...
to specify additional gcc commandline options.
One usecase is when trying to find gcc bugs but other
use cases has been requested too.
Patch was tested on following architectures:
alpha, arm, i386, x86_64, mips, sparc, sparc64, ia64, m68k
Test was simple to do a defconfig build, apply the patch and check
that nothing got rebuild.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index 677bc6c..b1a7c7d 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -75,7 +75,7 @@
# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
as-option = $(call try-run,\
- $(CC) $(CFLAGS) $(1) -c -xassembler /dev/null -o "$$TMP",$(1),$(2))
+ $(CC) $(KBUILD_CFLAGS) $(1) -c -xassembler /dev/null -o "$$TMP",$(1),$(2))
# as-instr
# Usage: cflags-y += $(call as-instr,instr,option1,option2)
@@ -87,12 +87,12 @@
# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
cc-option = $(call try-run,\
- $(CC) $(CFLAGS) $(1) -S -xc /dev/null -o "$$TMP",$(1),$(2))
+ $(CC) $(KBUILD_CFLAGS) $(1) -S -xc /dev/null -o "$$TMP",$(1),$(2))
# cc-option-yn
# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
cc-option-yn = $(call try-run,\
- $(CC) $(CFLAGS) $(1) -S -xc /dev/null -o "$$TMP",y,n)
+ $(CC) $(KBUILD_CFLAGS) $(1) -S -xc /dev/null -o "$$TMP",y,n)
# cc-option-align
# Prefix align with either -falign or -malign