Re: [Qemu-devel] [PATCH V6 1/5] libqblock build system

[wenchao xia <xiaxia347os@163.com>]

> On Sun, Oct 7, 2012 at 5:32 AM, Wenchao Xia <xiaxia347os@163.com> wrote:
>> From: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
>>
>>    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                       |   11 +++++-
>>   libqblock/Makefile             |   72 ++++++++++++++++++++++++++++++++++++++++
>>   libqblock/libqblock.pc.in      |   13 +++++++
>>   3 files changed, 95 insertions(+), 1 deletions(-)
>>   create mode 100644 libqblock/Makefile
>>   create mode 100644 libqblock/libqblock-error.c
>>   create mode 100644 libqblock/libqblock-error.h
>>   create mode 100644 libqblock/libqblock-internal.h
>>   create mode 100644 libqblock/libqblock-types.h
>>   create mode 100644 libqblock/libqblock.c
>>   create mode 100644 libqblock/libqblock.h
>>   create mode 100644 libqblock/libqblock.pc.in
>>
>> diff --git a/Makefile b/Makefile
>> index a9c22bf..53006c1 100644
>> --- a/Makefile
>> +++ b/Makefile
>> @@ -169,6 +169,15 @@ 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
>> +libqblock.la:
>> +       $(call quiet-command,$(MAKE) $(SUBDIR_MAKEFLAGS) -C libqblock V="$(V)" TARGET_DIR="$*/" libqblock.la,)
>
> Does not work for out of tree build:
> $ make -C obj-amd64 libqblock.la
> make: Entering directory `/src/qemu/obj-amd64'
> make: Entering an unknown directory
> make: *** libqblock: No such file or directory.  Stop.
> make: Leaving an unknown directory
> make: *** [libqblock.la] Error 2
> make: Leaving directory `/src/qemu/obj-amd64'
>
> If I fake what 'configure' should be doing and add the directory and
> link to Makefile, there are still problems:
> $ make -C obj-amd64 libqblock.la
> make: Entering directory `/src/qemu/obj-amd64'
> make[1]: *** No rule to make target `libqblock.lo', needed by
> `libqblock.la'.  Stop.
> make: *** [libqblock.la] Error 2
>
   Could u give more tip about this error? what is obj-amd64?
My understanding is you tried to build the library from another
directory similar as:
/extend_disk/xiawenc/qemu/qemu have the qemu source code, then
[xiawenc@RedHat62GAWSWenchao xiawenc]$ pwd
/extend_disk/xiawenc
[xiawenc@RedHat62GAWSWenchao xiawenc]$ make -C qemu/qemu libqblock.la
failed.
Please correct me.

> I think the library should be built by default, like vscclient which
> probably nobody uses.
>
   libvirt can't link to it now for OOM issue, but I will wrapper the
APIs with RPC later.

>> +
>> +install-libqblock:
>> +       $(call quiet-command,$(MAKE) $(SUBDIR_MAKEFLAGS) -C libqblock V="$(V)" TARGET_DIR="$*/" install-libqblock,)
>> +###########################################################################
>> +
>>   vscclient$(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  $@")
>>
>> @@ -232,7 +241,7 @@ 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/libqblock/Makefile b/libqblock/Makefile
>> new file mode 100644
>> index 0000000..cd5f4c1
>> --- /dev/null
>> +++ b/libqblock/Makefile
>> @@ -0,0 +1,72 @@
>> +###########################################################################
>> +# 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)
>> +
>> +#library objects
>> +libqblock-y=libqblock.o libqblock-error.o
>> +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
>> +
>> +
>> +QEMU_OBJS= $(libqblock-y) $(block-obj-y) $(tools-obj-y)
>> +QEMU_OBJS_LIB=$(patsubst %.o, %.lo, $(QEMU_OBJS))
>> +
>> +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 $(LIBS_TOOLS)
>> +
>> +#header files to be installed
>> +libqblock-pub-headers=libqblock.h libqblock-types.h libqblock-error.h
>> +libqblock_includedir=$(includedir)/qblock
>> +libqblock_srcpath=$(SRC_PATH)/libqblock
>> +
>> +#################################################################
>> +# Runtime rules
>> +#################################################################
>> +clean:
>> +       rm -f *.lo *.o *.d *.la libqblock-test trace.c trace.c-timestamp *.pc
>> +       rm -rf .libs block trace audio fsdev hw net qapi qga qom slirp ui
>> +
>> +all: libqblock.la libqblock.pc
>> +# Dummy command so that make thinks it has done something
>> +       @true
>> +
>> +libqblock.la: $(QEMU_OBJS_LIB)
>> +       $(call quiet-command,$(LIBTOOL) --mode=link --quiet --tag=CC $(CC) -rpath $(libdir) -o $@ $^ $(LIBS),"  lt LINK $@")
>> +
>> +libqblock.pc: $(libqblock_srcpath)/libqblock.pc.in
>> +       $(call quiet-command,sed -e 's|@LIBDIR@|$(libdir)|' \
>> +               -e 's|@INCLUDEDIR@|$(libqblock_includedir)|' \
>> +           -e 's|@VERSION@|$(shell cat $(SRC_PATH)/VERSION)|' \
>> +               -e 's|@PREFIX@|$(prefix)|' \
>> +               < $(libqblock_srcpath)/libqblock.pc.in > libqblock.pc,\
>> +       "  GEN   $@")
>> +
>> +.PHONY: install-libqblock
>> +
>> +install-libqblock: libqblock.la libqblock.pc
>> +       $(INSTALL_DIR) "$(DESTDIR)$(libdir)"
>> +       $(INSTALL_DIR) "$(DESTDIR)$(libdir)/pkgconfig"
>> +       $(INSTALL_DIR) "$(DESTDIR)$(libqblock_includedir)"
>> +       $(LIBTOOL) --mode=install $(INSTALL_DATA) libqblock.la "$(DESTDIR)$(libdir)"
>> +       $(LIBTOOL) --mode=install $(INSTALL_DATA) libqblock.pc "$(DESTDIR)$(libdir)/pkgconfig"
>> +       $(LIBTOOL) --mode=install $(INSTALL_DATA) $(libqblock-pub-headers) "$(DESTDIR)$(libqblock_includedir)"
>> diff --git a/libqblock/libqblock-error.c b/libqblock/libqblock-error.c
>> new file mode 100644
>> index 0000000..e69de29
>> diff --git a/libqblock/libqblock-error.h b/libqblock/libqblock-error.h
>> new file mode 100644
>> index 0000000..e69de29
>> diff --git a/libqblock/libqblock-internal.h b/libqblock/libqblock-internal.h
>> new file mode 100644
>> index 0000000..e69de29
>> diff --git a/libqblock/libqblock-types.h b/libqblock/libqblock-types.h
>> new file mode 100644
>> index 0000000..e69de29
>> diff --git a/libqblock/libqblock.c b/libqblock/libqblock.c
>> new file mode 100644
>> index 0000000..e69de29
>> diff --git a/libqblock/libqblock.h b/libqblock/libqblock.h
>> new file mode 100644
>> index 0000000..e69de29
>> diff --git a/libqblock/libqblock.pc.in b/libqblock/libqblock.pc.in
>> new file mode 100644
>> index 0000000..d2a7d06
>> --- /dev/null
>> +++ b/libqblock/libqblock.pc.in
>> @@ -0,0 +1,13 @@
>> +prefix=@PREFIX@
>> +exec_prefix=${prefix}
>> +libdir=@LIBDIR@
>> +includedir=@INCLUDEDIR@
>> +
>> +Name: qblock
>> +Description: QEMU block layer library
>> +Version: @VERSION@
>> +
>> +Requires:  rt gthread-2.0 glib-2.0 z curl cap-ng uuid
>> +Libs: -L${libdir} -lqblock
>> +Libs.private:
>> +Cflags: -I${includedir}
>> --
>> 1.7.1
>>
>>
>>