Re: [Qemu-devel] [PATCH V3 1/5] libqblock build system

[Wenchao Xia]

于 2012-9-18 18:05, Paolo Bonzini 写道:
> Il 18/09/2012 11:01, Wenchao Xia ha scritto:
> >    Libqblock was placed in new directory ./libqblock, libtool will build
> > dynamic library there, source files of block layer remains in ./block.
> > So block related source code will generate 3 sets of binary, first is old
> > ones used in qemu, second and third are non PIC and PIC ones in ./libqblock.
> >    GCC compiler flag visibility=hidden was used with special macro, to export
> > only symbols that was marked as PUBLIC.
> >
> > Signed-off-by: Wenchao Xia <address@hidden>
> > ---
> >   Makefile                    |   13 ++++++++-
> >   Makefile.objs               |    6 ++++
> >   libqblock/Makefile          |   64 +++++++++++++++++++++++++++++++++++++++++++
> >   3 files changed, 82 insertions(+), 1 deletions(-)
> >   create mode 100644 libqblock/Makefile
> >   create mode 100644 libqblock/libqblock-error.c
> >   create mode 100644 libqblock/libqblock.c
> >
> > diff --git a/Makefile b/Makefile
> > index 971e92f..b0b9b8d 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -164,6 +164,17 @@ qemu-io$(EXESUF): qemu-io.o cmd.o $(tools-obj-y) 
> > $(block-obj-y)
> >
> >   qemu-bridge-helper$(EXESUF): qemu-bridge-helper.o
> >
> > +######################################################################
> > +# Support building shared library libqblock
> > +ifeq ($(LIBTOOL),)
> > +$(libqblock-lib-la):
> > +       @echo "libtool is missing, please install and rerun configure"; exit 1
> > +else
> > +$(libqblock-lib-la):
> > +       $(call quiet-command,$(MAKE) $(SUBDIR_MAKEFLAGS) -C libqblock V="$(V)" 
> > TARGET_DIR="$*/" $(libqblock-lib-la),)
> > +endif
> > +###########################################################################
> > +
> >   vscclient$(EXESUF): $(libcacard-y) $(oslib-obj-y) $(trace-obj-y) 
> > $(tools-obj-y) qemu-timer-common.o libcacard/vscclient.o
> >         $(call quiet-command,$(CC) $(LDFLAGS) -o $@ $^ $(libcacard_libs) $(LIBS),"  
> > LINK  $@")
> >
> > @@ -227,7 +238,7 @@ clean:
> >         rm -rf qapi-generated
> >         rm -rf qga/qapi-generated
> >         $(MAKE) -C tests/tcg clean
> > -       for d in $(ALL_SUBDIRS) $(QEMULIBS) libcacard; do \
> > +       for d in $(ALL_SUBDIRS) $(QEMULIBS) libcacard libqblock; do \
> >         if test -d $$d; then $(MAKE) -C $$d $@ || exit 1; fi; \
> >         rm -f $$d/qemu-options.def; \
> >           done
> > diff --git a/Makefile.objs b/Makefile.objs
> > index 4412757..8a4c9fc 100644
> > --- a/Makefile.objs
> > +++ b/Makefile.objs
> > @@ -248,3 +248,9 @@ nested-vars += \
> >         common-obj-y \
> >         extra-obj-y
> >   dummy := $(call unnest-vars)
> > +
> > +#############################################################################
> > +# libqblock
> > +
> > +libqblock-lib-la = libqblock.la
> > +libqblock-lib-path = libqblock
> > diff --git a/libqblock/Makefile b/libqblock/Makefile
> > new file mode 100644
> > index 0000000..bf7abcc
> > --- /dev/null
> > +++ b/libqblock/Makefile
> > @@ -0,0 +1,64 @@
> > +###########################################################################
> > +# libqblock Makefile
> > +# Todo:
> > +#    1 trace related files is generated in this directory, move
> > +#  them to the root directory.
> > +##########################################################################
> > +-include ../config-host.mak
> > +-include $(SRC_PATH)/Makefile.objs
> > +-include $(SRC_PATH)/rules.mak
> > +
> > +#############################################################################
> > +# Library settings
> > +#############################################################################
> > +$(call set-vpath, $(SRC_PATH))
> > +
> > +#expand the foldered vars,especially ./block
> > +dummy := $(call unnest-vars-1)
> > +
> > +#library objects
> > +tools-obj-y = $(oslib-obj-y) $(trace-obj-y) qemu-tool.o qemu-timer.o \
> > +       qemu-timer-common.o main-loop.o notify.o \
> > +       iohandler.o cutils.o iov.o async.o
> > +tools-obj-$(CONFIG_POSIX) += compatfd.o
>
> Do you really need all of these?
  I guess only some .o are needed, but not sure how to pick them out, 
is there some tools which can help detect which object files are needed
in final linkage?

> (BTW, I posted recently a patch to move tools-obj-y to Makefile.objs.
> It doesn't apply anymore, I'll repost---but the conflicts are trivial).
  greate, then I can use tools-obj-y directly.

> > +libqblock-y=libqblock.o libqblock-error.o
> > +libqblock-lib-y=$(patsubst %.o,%.lo,$(libqblock-y))
> > +
> > +QEMU_OBJS=$(tools-obj-y) $(block-obj-y)
> > +QEMU_OBJS_FILTERED=$(filter %.o,$(QEMU_OBJS))
>
> What does this filter out?
  $(block-obj-y) contains /block, which would cause trouble in building,
so filtered it out.

> Paolo
>
> > +QEMU_OBJS_LIB=$(patsubst %.o, %.lo,$(QEMU_OBJS_FILTERED))
> > +
> > +QEMU_CFLAGS+= -I../ -I../include
> > +#adding magic macro define for symbol hiding and exposing
> > +QEMU_CFLAGS+= -fvisibility=hidden -D LIBQB_BUILD
> > +
> > +#dependency libraries
> > +LIBS+=-lz $(LIBS_TOOLS)
> > +
> > +#################################################################
> > +# Runtime rules
> > +#################################################################
> > +clean:
> > +       rm -f *.lo *.o *.d *.la libqblock-test trace.c trace.c-timestamp
> > +       rm -rf .libs block trace
> > +
> > +all: libqblock-test
> > +       @true
> > +
> > +help:
> > +       @echo type make libqblock-test at root dirtory, libtool is required
> > +
> > +#make dir block at runtime which would hold the output of block/*.c
> > +block:
> > +       @mkdir block
> > +
> > +ifeq ($(LIBTOOL),)
> > +$(libqblock-lib-la):
> > +       @echo "libtool is missing, please install and rerun configure"; exit 1
> > +else
> > +$(libqblock-lib-la): $(libqblock-lib-y) $(QEMU_OBJS_LIB)
> > +       $(call quiet-command,$(LIBTOOL) --mode=link --quiet --tag=CC $(CC) -rpath 
> > $(libdir) -o $@ $^ $(LIBS),"  lt LINK $@")
> > +endif
> > +
> > +.PHONY: libqblock.la
> > diff --git a/libqblock/libqblock-error.c b/libqblock/libqblock-error.c
> > new file mode 100644
> > index 0000000..e69de29
> > diff --git a/libqblock/libqblock.c b/libqblock/libqblock.c
> > new file mode 100644
> > index 0000000..e69de29


--
Best Regards

Wenchao Xia