Re: [Qemu-devel] [PATCH v6 2/8] rule.mak: allow per object cflags and libs

[Paolo Bonzini <pbonzini@redhat.com>]

Il 11/09/2013 15:34, Fam Zheng ha scritto:
> Adds extract-libs in LINK to expand any "per object libs", the syntax to define
> such a libs options is like:
> 
>         foo.o-libs := $(CURL_LIBS)
> 
> in block/Makefile.objs.
> 
> Similarly,
> 
>         foo.o-cflags := $(FOO_CFLAGS)
> 
> is also supported.
> 
> "foo.o" must be listed a nested var (e.g. common-obj-y) to make the
> option variables effective.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  rules.mak | 19 ++++++++++++++++---
>  1 file changed, 16 insertions(+), 3 deletions(-)
> 
> diff --git a/rules.mak b/rules.mak
> index 9344c27..b1d53b5 100644
> --- a/rules.mak
> +++ b/rules.mak
> @@ -17,15 +17,17 @@ QEMU_DGFLAGS += -MMD -MP -MT $@ -MF $(*D)/$(*F).d
>  # Same as -I$(SRC_PATH) -I., but for the nested source/object directories
>  QEMU_INCLUDES += -I$(<D) -I$(@D)
>  
> +extract-libs = $(strip $(foreach o,$1,$($o-libs)))
> +
>  %.o: %.c
> -	$(call quiet-command,$(CC) $(QEMU_INCLUDES) $(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) -c -o $@ $<,"  CC    $(TARGET_DIR)$@")
> +	$(call quiet-command,$(CC) $(QEMU_INCLUDES) $(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) $($@-cflags) -c -o $@ $<,"  CC    $(TARGET_DIR)$@")
>  %.o: %.rc
>  	$(call quiet-command,$(WINDRES) -I. -o $@ $<,"  RC    $(TARGET_DIR)$@")
>  
>  ifeq ($(LIBTOOL),)
>  LINK = $(call quiet-command,$(CC) $(QEMU_CFLAGS) $(CFLAGS) $(LDFLAGS) -o $@ \
>         $(sort $(filter %.o, $1)) $(filter-out %.o, $1) $(version-obj-y) \
> -       $(LIBS),"  LINK  $(TARGET_DIR)$@")
> +       $(call extract-libs,$^) $(LIBS),"  LINK  $(TARGET_DIR)$@")
>  else
>  LIBTOOL += $(if $(V),,--quiet)
>  %.lo: %.c
> @@ -41,7 +43,7 @@ LINK = $(call quiet-command,\
>         $(sort $(filter %.o, $1)) $(filter-out %.o, $1) \
>         $(if $(filter %.lo %.la,$^),$(version-lobj-y),$(version-obj-y)) \
>         $(if $(filter %.lo %.la,$^),$(LIBTOOLFLAGS)) \
> -       $(LIBS),$(if $(filter %.lo %.la,$^),"lt LINK ", "  LINK  ")"$(TARGET_DIR)$@")
> +       $(call extract-libs,$^) $(LIBS),$(if $(filter %.lo %.la,$^),"lt LINK ", "  LINK  ")"$(TARGET_DIR)$@")
>  endif
>  
>  %.asm: %.S
> @@ -114,11 +116,22 @@ $(eval $1 = $(value save-$2-$1) $$(subdir-$2-$1))
>  $(eval save-$2-$1 :=)
>  endef
>  
> +define fix-obj-vars
> +$(foreach v,$($1), \
> +	$(if $($v-cflags), \
> +		$(eval $2$v-cflags := $($v-cflags)) \
> +		$(eval $v-cflags := )) \
> +	$(if $($v-libs), \
> +		$(eval $2$v-libs := $($v-libs)) \
> +		$(eval $v-libs := )))
> +endef
> +
>  define unnest-dir
>  $(foreach var,$(nested-vars),$(call push-var,$(var),$1/))
>  $(eval obj-parent-$1 := $(obj))
>  $(eval obj := $(if $(obj),$(obj)/$1,$1))
>  $(eval include $(SRC_PATH)/$1/Makefile.objs)
> +$(foreach v,$(nested-vars),$(call fix-obj-vars,$v,$(if $(obj),$(obj)/)))
>  $(eval obj := $(obj-parent-$1))
>  $(eval obj-parent-$1 := )
>  $(foreach var,$(nested-vars),$(call pop-var,$(var),$1/))
> 

I'm not sure this will work for targets in the toplevel directory when
obj-base is not empty.  This can be fixed later though, as part of a
general revamping of obj-base.  Please add a FIXME comment.

Paolo