On Thu, Apr 12, 2012 at 10:35 PM, Sam Ravnborg <sam@xxxxxxxxxxxx> wrote:
> On Thu, Apr 12, 2012 at 10:17:07PM +0200, Geert Uytterhoeven wrote:
>> On Thu, Apr 12, 2012 at 22:07, Sam Ravnborg <sam@xxxxxxxxxxxx> wrote:
>> > Could you try this:
>> >
>> > cc-disable-opt = $(call try-run,\
>> > $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -f$(strip $(1)) -c -xc /dev/null -o "$TMP",-fno-$(strip $(1)))
>> >
>> > KBUILD_CFLAGS += $(call cc-disable-opt, ipa-cp-clone)
>> >
>> >
>> > It will try if "gcc -fipa-cp-clone" is supported,
>> > and add -fno-ipa-cp-clone in that case.
>>
>> Unfortunately not:
>>
>> m68k-linux-gnu-gcc -Wp,-MD,kernel/.bounds.s.d -nostdinc -isystem
>> /usr/lib/gcc/m68k-linux-gnu/4.1.2/include
>> -I/scratch/geert/linux/linux-next/arch/m68k/include
>> Iarch/m68k/include/generated -Iinclude -include
>> /scratch/geert/linux/linux-next/include/linux/kconfig.h -D__KERNEL__
>> -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing
>> -fno-common -Werror-implicit-function-declaration -Wno-format-security
>> -fno-delete-null-pointer-checks -Os -fno-reorder-blocks
>> -fno-ipa-cp-clone -pipe -fno-strength-reduce -ffixed-a2
>> -fno-omit-frame-pointer -fno-optimize-sibling-calls -g
>> -D"KBUILD_STR(s)=#s" -D"KBUILD_BASENAME=KBUILD_STR(bounds)"
>> -D"KBUILD_MODNAME=KBUILD_STR(bounds)" -fverbose-asm -S -o
>> kernel/bounds.s kernel/bounds.c
>> cc1: error: unrecognized command line option "-fno-ipa-cp-clone"
>> make[1]: *** [kernel/bounds.s] Error 1
>> make: *** [prepare0] Error 2
>
> So with the above command-line gcc fails with an exit code for -fno-ipa-cp-clone.
> But with cc-option it does not.
>
> Can you dig out the command-line used for cc-option?
> We may be able to analyze why it fails in the above case, but
> not with cc-option.
gcc -D__KERNEL__ -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs
-fno-strict-aliasing -fno-common -Werror-implicit-function-declaration
-Wno-format-security -fno-delete-null-pointer-checks -Os
-fno-ipa-cp-clone -c -xc /dev/null -o .6376.tmp
So it's running "gcc" instead of "m68k-linux-gnu-gcc".
I used the gmail-damaged patch below to get the command in /tmp/x.
diff --git a/Makefile b/Makefile
index d17a616..0e0cbb9 100644
--- a/Makefile
+++ b/Makefile
@@ -567,7 +567,7 @@ ifdef CONFIG_READABLE_ASM
# ipa clone creates specialized cloned functions
# partial inlining inlines only parts of functions
KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
- $(call cc-option,-fno-ipa-cp-clone,) \
+ $(call cc-option2,-fno-ipa-cp-clone,) \
$(call cc-option,-fno-partial-inlining)
endif
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index 6a3ee98..41c80bf 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -94,6 +94,16 @@ try-run = $(shell set -e; \
fi; \
rm -f "$$TMP" "$$TMPO")
+try-run2 = $(shell set -e; \
+ TMP="$(TMPOUT).$$$$.tmp"; \
+ TMPO="$(TMPOUT).$$$$.o"; \
+ echo "$(1)" > /tmp/x; \
+ if ($(1)) >/dev/null 2>&1; \
+ then echo "$(2)"; \
+ else echo "$(3)"; \
+ fi; \
+ rm -f "$$TMP" "$$TMPO")
+
# as-option
# Usage: cflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
@@ -112,6 +122,9 @@ as-instr = $(call try-run,\
cc-option = $(call try-run,\
$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -xc
/dev/null -o "$$TMP",$(1),$(2))
+cc-option2 = $(call try-run2,\
+ $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -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,\
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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