On Tue, Oct 15, 2019 at 12:29 AM Thomas Huth <thuth@xxxxxxxxxx> wrote: > > On 10/10/2019 20.35, Bill Wendling wrote: > > The "cc-option" macro should use "-Werror" to determine if a flag is > > supported. Otherwise the test may not return a nonzero result. Also > > conditionalize some of the warning flags which aren't supported by > > clang. > > > > Signed-off-by: Bill Wendling <morbo@xxxxxxxxxx> > > --- > > Makefile | 19 +++++++++++-------- > > 1 file changed, 11 insertions(+), 8 deletions(-) > > > > diff --git a/Makefile b/Makefile > > index 32414dc..3ec0458 100644 > > --- a/Makefile > > +++ b/Makefile > > @@ -46,30 +46,33 @@ include $(SRCDIR)/$(TEST_DIR)/Makefile > > # cc-option > > # Usage: OP_CFLAGS+=$(call cc-option, -falign-functions=0, -malign-functions=0) > > > > -cc-option = $(shell if $(CC) $(1) -S -o /dev/null -xc /dev/null \ > > +cc-option = $(shell if $(CC) -Werror $(1) -S -o /dev/null -xc /dev/null \ > > > /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi ;) > > > > COMMON_CFLAGS += -g $(autodepend-flags) > > -COMMON_CFLAGS += -Wall -Wwrite-strings -Wclobbered -Wempty-body -Wuninitialized > > -COMMON_CFLAGS += -Wignored-qualifiers -Wunused-but-set-parameter > > -COMMON_CFLAGS += -Werror > > +COMMON_CFLAGS += -Wall -Wwrite-strings -Wempty-body -Wuninitialized > > +COMMON_CFLAGS += -Wignored-qualifiers -Werror > > + > > frame-pointer-flag=-f$(if $(KEEP_FRAME_POINTER),no-,)omit-frame-pointer > > fomit_frame_pointer := $(call cc-option, $(frame-pointer-flag), "") > > fnostack_protector := $(call cc-option, -fno-stack-protector, "") > > fnostack_protector_all := $(call cc-option, -fno-stack-protector-all, "") > > -wno_frame_address := $(call cc-option, -Wno-frame-address, "") > > fno_pic := $(call cc-option, -fno-pic, "") > > no_pie := $(call cc-option, -no-pie, "") > > COMMON_CFLAGS += $(fomit_frame_pointer) > > COMMON_CFLAGS += $(fno_stack_protector) > > COMMON_CFLAGS += $(fno_stack_protector_all) > > -COMMON_CFLAGS += $(wno_frame_address) > > COMMON_CFLAGS += $(if $(U32_LONG_FMT),-D__U32_LONG_FMT__,) > > COMMON_CFLAGS += $(fno_pic) $(no_pie) > > > > +COMMON_CFLAGS += $(call cc-option, -Wno-frame-address, "") > > I think the old code used ":=" on purpose, so that the test is only done > once. With your new code, the test is now done each time COMMON_CFLAGS > gets evaluated, i.e. for each compiled object. > > Could you please rewrite this test to use the ":=" detour for all lines > that call cc-option? > Does it rerun the "cc-option" call if the COMMON_CFLAGS is initially defined with ":="? I ask because the kernel calls its version of cc-option in the way I have it above, but the original definition of the variable uses ":=". -bw
