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

[Paolo Bonzini <pbonzini@redhat.com>]

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 <xiawenc@linux.vnet.ibm.com>
> ---
>  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?

(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).

> +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?

> +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

Do not put yet the libqblock-test rules in here, please.

Paolo

> +	@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
>