The macro cc-option receives two parameters (the second may be empty). It returns the first parameter if it is a valid compiler option, otherwise the second one. It is not evaluated if the second parameter is a valid compiler option. This seems to be fine in virtually all cases, however there are scenarios where the second paramater needs to be evaluated too, and an empty value (or a third option) should be returned if it is not valid. The macro cc-option-3 receives three parameters and returns parameter 1 or 2 (in this order) if one of them is found to be a valid compiler option, and otherwise paramater 3. The macro __cc-option-3 works analogously. Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx> --- scripts/Kbuild.include | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index dd8e2dde0b34..dc83635f2317 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -113,6 +113,11 @@ as-instr = $(call try-run,\ __cc-option = $(call try-run,\ $(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4)) +# __cc-option-3 +# Usage: MY_CFLAGS += $(call __cc-option-3,$(CC),$(MY_CFLAGS),\ +# -mpreferred-stack-boundary=2,-mstack-alignment=4,) +__cc-option-3 = $(call __cc-option,$(1),$(2),$(3),$(call __cc-option,$(1),$(2),$(4),$(5))) + # Do not attempt to build with gcc plugins during cc-option tests. # (And this uses delayed resolution so the flags will be up to date.) CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS)) @@ -123,6 +128,10 @@ CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS)) cc-option = $(call __cc-option, $(CC),\ $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS),$(1),$(2)) +# cc-option-3 +# Usage: cflags-y += $(call cc-option-3,-mpreferred-stack-boundary=3,-mstack-alignment=8,) +cc-option-3 = $(call cc-option,$(1),$(call cc-option,$(2),$(3))) + # hostcc-option # Usage: cflags-y += $(call hostcc-option,-march=winchip-c6,-march=i586) hostcc-option = $(call __cc-option, $(HOSTCC),\ -- 2.14.0.rc0.284.gd933b75aa4-goog -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
