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

[Fam Zheng]

On Tue, 09/10 08:34, Paolo Bonzini wrote:
> 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 <address@hidden>
> 
> 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

You are right, I'd do it respectively, since...

> 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.
> 
it's not working.

The base point of unnesting is fixed to SRC_PATH:

    define unnest-dir
    ...
    $(eval include $(SRC_PATH)/$1/Makefile.objs)
    ...
    endef

So it can't unnest  "../". block-obj-y = ./ makes a little more sense, but
$(obj) can be messed, again.

Do you think two calls of unnest-vars OK?

    nested-vars = obj-y
    dummy := $(call unnest-vars)
    include $(SRC_PATH)/Makefile.objs
    obj-base := ..
    nested-vars = block-obj-y common-obj-y
    dummy := $(call unnest-vars)

> > +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
> > 
>