Re: [Qemu-devel] [PATCH] libcacard: add libcacard.la target

[Alon Levy <alevy@redhat.com>]

On Mon, May 16, 2011 at 08:28:49AM -0500, Anthony Liguori wrote:
> On 05/16/2011 08:25 AM, Alon Levy wrote:
> >No flag to configure is required. Instead, added a libcacard.la target that
> >is not built by default, only when requested explicitly via:
> >
> >mkdir build
> >cd build
> >../configure
> >make libcacard.la
> >make install-libcacard
> >
> >Uses libtool to do actual linking of object files and shared library, and
> >installing. Tested only under linux, but supposed to work on other systems as
> >well.
> >
> >If libtool isn't found you get a message complaining about that, only at build
> >time (since it is not a default target I did not add a message at configure
> >time).
> >
> >Note: please ignore the following warning message, it is harmless, and fixing
> >it would require using libtool to build trace-dtrace.lo which, since it isn't
> >built by gcc, I don't know how to do.
> >
> >  *** Warning: Linking the shared library libcacard.la against the non-libtool
> >  *** objects  ../trace-dtrace.o is not portable!
> 
> I don't think slipping in libtool like this is such a good idea.

Forgot from my reply to Paolo: libtool is complaining about the only object I didn't
rebuild, trace-dtrace.o, the rest I've added rules specifically to rebuild into lo
(-fPIC'ed) objects under libcacard (including specifically any qemu support code). I
didn't do the same for trace-dtrace.o because a) I didn't find an easy way of doing it
on account of it not being built by gcc b) it wasn't a real problem like I mentioned in
the reply to Paolo.

> 
> Why do you need this target?
Answered in the reply to Paolo's email.

> 
> Isn't la just a static archive compiled with -fPIC?  Doesn't the
> whole code base need to be compiled with -fPIC then (and isn't the
> warning above a legitimate concern?).
> 
> Regards,
> 
> Anthony Liguori
> 
> >---
> >  Makefile           |   17 +++++++++++++++++
> >  configure          |   12 +++++++++++-
> >  libcacard/Makefile |   38 ++++++++++++++++++++++++++++++++++----
> >  3 files changed, 62 insertions(+), 5 deletions(-)
> >
> >diff --git a/Makefile b/Makefile
> >index 2b0438c..0215307 100644
> >--- a/Makefile
> >+++ b/Makefile
> >@@ -119,6 +119,23 @@ version.o: $(SRC_PATH)/version.rc config-host.mak
> >
> >  version-obj-$(CONFIG_WIN32) += version.o
> >  ######################################################################
> >+# Support building shared library libcacard
> >+
> >+.PHONY: libcacard.la install-libcacard
> >+ifeq ($(LIBTOOL),)
> >+libcacard.la:
> >+	@echo libtool is missing, please install and rerun configure
> >+
> >+install-libcacard:
> >+	@echo libtool is missing, please install and rerun configure
> >+else
> >+libcacard.la: $(GENERATED_HEADERS) $(oslib-obj-y) qemu-malloc.o qemu-timer-common.o $(trace-obj-y)
> >+	$(call quiet-command,$(MAKE) $(SUBDIR_MAKEFLAGS) -C libcacard V="$(V)" TARGET_DIR="$*/" libcacard.la,)
> >+
> >+install-libcacard: libcacard.la
> >+	$(call quiet-command,$(MAKE) $(SUBDIR_MAKEFLAGS) -C libcacard V="$(V)" TARGET_DIR="$*/" install-libcacard,)
> >+endif
> >+######################################################################
> >
> >  qemu-img.o: qemu-img-cmds.h
> >  qemu-img.o qemu-tool.o qemu-nbd.o qemu-io.o cmd.o: $(GENERATED_HEADERS)
> >diff --git a/configure b/configure
> >index 0627f1d..e62841e 100755
> >--- a/configure
> >+++ b/configure
> >@@ -1276,6 +1276,15 @@ if ! has $pkg_config; then
> >  fi
> >
> >  ##########################################
> >+# libtool probe
> >+
> >+if ! has libtool; then
> >+    libtool=
> >+else
> >+    libtool=libtool
> >+fi
> >+
> >+##########################################
> >  # Sparse probe
> >  if test "$sparse" != "no" ; then
> >    if has cgcc; then
> >@@ -3060,6 +3069,7 @@ echo "AR=$ar">>  $config_host_mak
> >  echo "OBJCOPY=$objcopy">>  $config_host_mak
> >  echo "LD=$ld">>  $config_host_mak
> >  echo "WINDRES=$windres">>  $config_host_mak
> >+echo "LIBTOOL=$libtool">>  $config_host_mak
> >  echo "CFLAGS=$CFLAGS">>  $config_host_mak
> >  echo "QEMU_CFLAGS=$QEMU_CFLAGS">>  $config_host_mak
> >  echo "QEMU_INCLUDES=$QEMU_INCLUDES">>  $config_host_mak
> >@@ -3595,7 +3605,7 @@ if [ "$source_path" != `pwd` ]; then
> >      # out of tree build
> >      mkdir -p libcacard
> >      rm -f libcacard/Makefile
> >-    ln -s "$source_path/libcacard/Makefile" libcacard/Makefile
> >+    symlink "$source_path/libcacard/Makefile" libcacard/Makefile
> >  fi
> >
> >  d=libuser
> >diff --git a/libcacard/Makefile b/libcacard/Makefile
> >index 1d34df0..3a5ad61 100644
> >--- a/libcacard/Makefile
> >+++ b/libcacard/Makefile
> >@@ -4,15 +4,45 @@
> >
> >  $(call set-vpath, $(SRC_PATH):$(SRC_PATH)/libcacard)
> >
> >-QEMU_OBJS=$(addprefix ../, $(oslib-obj-y) $(trace-obj-y) qemu-malloc.o qemu-timer-common.o)
> >+QEMU_TRACE_OBJS=$(addprefix ../,$(trace-obj-y))
> >+
> >+QEMU_BASE_OBJS=$(addprefix ../,$(oslib-obj-y) qemu-malloc.o qemu-timer-common.o)
> >+
> >+# objects linked against normal qemu binaries, not compiled with libtool
> >+QEMU_OBJS = $(QEMU_BASE_OBJS) $(QEMU_TRACE_OBJS)
> >+
> >+# objects linked into a shared library, built with libtool with -fPIC if required
> >+QEMU_BASE_OBJS_LIB=$(addsuffix .lo,$(basename $(QEMU_BASE_OBJS)))
> >+
> >+QEMU_OBJS_LIB = $(QEMU_BASE_OBJS_LIB) $(QEMU_TRACE_OBJS)
> >
> >  QEMU_CFLAGS+=-I../
> >
> >+libcacard.lib-y=$(addsuffix .lo,$(basename $(libcacard-y)))
> >+
> >  vscclient: $(libcacard-y) $(QEMU_OBJS) vscclient.o
> >-	$(call quiet-command,$(CC) $(libcacard_libs) -lrt -o $@ $^,"  LINK  $(TARGET_DIR)$@")
> >+	$(call quiet-command,$(CC) $(libcacard_libs) -lrt -o $@ $^,"  LINK  $@")
> >+
> >+clean:
> >+	rm -f *.o */*.o *.d */*.d *.a */*.a *~ */*~ vscclient libcacard.so *.lo .libs/* *.la
> >+	rm -Rf .libs
> >
> >  all: vscclient
> >
> >-clean:
> >-	rm -f *.o */*.o *.d */*.d *.a */*.a *~ */*~ vscclient
> >+ifeq ($(LIBTOOL),)
> >+libcacard.la:
> >+	@echo libtool is missing, please install and rerun configure
> >+
> >+install-libcacard:
> >+	@echo libtool is missing, please install and rerun configure
> >+else
> >+$(libcacard.lib-y) $(QEMU_BASE_OBJS_LIB) : %.lo: %.c
> >+	$(call quiet-command,libtool --mode=compile --quiet --tag=CC $(CC) $(QEMU_CFLAGS) $(QEMU_INCLUDES) $(QEMU_DGFLAGS) $(CFLAGS) -c -o $@ $<,"  lt CC $@")
> >+
> >+libcacard.la: $(libcacard.lib-y) $(QEMU_OBJS_LIB)
> >+	$(call quiet-command,libtool --mode=link --quiet --tag=CC $(CC) $(libcacard_libs) -lrt -rpath $(libdir) -o $@ $^,"  lt LINK $@")
> >
> >+install-libcacard: libcacard.la
> >+	$(INSTALL_DIR) "$(DESTDIR)$(libdir)"
> >+	libtool --mode=install $(INSTALL_PROG) libcacard.la "$(DESTDIR)$(libdir)"
> >+endif
>