Re: [Qemu-devel] [RFC PATCH v3 1/5] make.rule: fix $(obj) to a real relative path

[Paolo Bonzini <pbonzini@redhat.com>]

Il 10/09/2013 03:02, Fam Zheng ha scritto:
> Makefile.target includes rule.mak and unnested common-obj-y, then prefix
> them with '../', this will ignore object specific QEMU_CFLAGS in subdir
> Makefile.objs:
> 
>     $(obj)/curl.o: QEMU_CFLAGS += $(CURL_CFLAGS)
> 
> Because $(obj) here is './block', instead of '../block'. This doesn't
> hurt compiling because we basically build all .o from top Makefile,
> before entering Makefile.target, but it will affact arriving per-object
> libs support.
> 
> The starting point of $(obj) is fixed in $(obj-base) before including
> ./Makefile.objs, to get consistency with nested Makefile rules in target
> rule and variable definition.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>

Glad this worked. )

> -dummy := $(call unnest-vars)
> diff --git a/Makefile.target b/Makefile.target
> index 9a49852..381022d 100644
> --- a/Makefile.target
> +++ b/Makefile.target
> @@ -143,13 +143,15 @@ endif # CONFIG_SOFTMMU
>  # Workaround for http://gcc.gnu.org/PR55489, see configure.
>  %/translate.o: QEMU_CFLAGS += $(TRANSLATE_OPT_CFLAGS)
>  
> -nested-vars += obj-y
> +nested-vars += obj-y block-obj-y common-obj-y
>  
>  # This resolves all nested paths, so it must come last

This comment is now obsolete.

>  include $(SRC_PATH)/Makefile.objs
> +obj-base := ..

Strictly speaking obj-base=.. is incorrect for obj-y, isn't it?  Does it
work if you do

block-obj-y = ../
common-obj-y = ../

instead of including $(SRC_PATH)/Makefile.objs? Then obj-base can be
empty and is not needed.

But the patch looks good already, I'm asking mostly to get a better
understanding of the system.

Paolo

> +dummy := $(call unnest-vars)
>  
>  all-obj-y = $(obj-y)
> -all-obj-y += $(addprefix ../, $(common-obj-y))
> +all-obj-y += $(addprefix ../, $(common-obj-y) $(block-obj-y))
>  
>  ifndef CONFIG_HAIKU
>  LIBS+=-lm
> diff --git a/configure b/configure
> index e989609..cc3cd4d 100755
> --- a/configure
> +++ b/configure
> @@ -2251,6 +2251,7 @@ fi
>  if $pkg_config --atleast-version=$glib_req_ver gthread-2.0; then
>      glib_cflags=`$pkg_config --cflags gthread-2.0`
>      glib_libs=`$pkg_config --libs gthread-2.0`
> +    CFLAGS="$glib_cflags $CFLAGS"
>      LIBS="$glib_libs $LIBS"
>      libs_qga="$glib_libs $libs_qga"
>  else
> diff --git a/rules.mak b/rules.mak
> index 4499745..3ff7d7a 100644
> --- a/rules.mak
> +++ b/rules.mak
> @@ -103,7 +103,7 @@ clean: clean-timestamp
>  
>  # magic to descend into other directories
>  
> -obj := .
> +obj = $(obj-base)
>  old-nested-dirs :=
>  
>  define push-var
> @@ -119,9 +119,11 @@ endef
>  
>  define unnest-dir
>  $(foreach var,$(nested-vars),$(call push-var,$(var),$1/))
> -$(eval obj := $(obj)/$1)
> +$(eval obj-parent-$1 := $(obj))
> +$(eval obj := $(if $(obj),$(obj)/$1,$1))
>  $(eval include $(SRC_PATH)/$1/Makefile.objs)
> -$(eval obj := $(patsubst %/$1,%,$(obj)))
> +$(eval obj := $(obj-parent-$1))
> +$(eval obj-parent-$1 := )
>  $(foreach var,$(nested-vars),$(call pop-var,$(var),$1/))
>  endef
>  
> diff --git a/tests/Makefile b/tests/Makefile
> index baba9e9..15ef039 100644
> --- a/tests/Makefile
> +++ b/tests/Makefile
> @@ -110,6 +110,10 @@ test-qapi-obj-y = tests/test-qapi-visit.o tests/test-qapi-types.o
>  $(test-obj-y): QEMU_INCLUDES += -Itests
>  QEMU_CFLAGS += -I$(SRC_PATH)/tests
>  
> +nested-vars := block-obj-y
> +obj-base := ..
> +dummy := $(call unnest-vars)
> +
>  tests/test-x86-cpuid.o: QEMU_INCLUDES += -I$(SRC_PATH)/target-i386
>  
>  tests/check-qint$(EXESUF): tests/check-qint.o libqemuutil.a
>