libcacard: add libcacard.la target

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).

New build artifacts:
 .libs subdirectories (at <buildroot> and <buildroot>/libcacard)
 *.lo files (at same locations as the respective o files)

Added %.lo : %.c rule that uses libtool.
Updated clean rule to clean up those artifacts.
Added specific rule to call dtrace with libtool wrapper (note that because of
a current upstream dtrace bug fixed by systemtap b1568fd85 commit the -fPIC flag
isn't actually passed on. still current dtrace+libtool produced object links fine).
If libtool is missing any of the following targets will complain and exit 1:
 any subdir: *.lo
 root and libcacard: libcacard.la, libcacard-instsall

Tested to link and load with all tracing backends.

5 files changed, 74 insertions, 6 deletions

diff --git a/Makefile b/Makefile
index 096480befa..b3ffbe2407 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"; exit 1
+
+install-libcacard:
+	@echo "libtool is missing, please install and rerun configure"; exit 1
+else
+libcacard.la: $(GENERATED_HEADERS) $(oslib-obj-y) qemu-malloc.o qemu-timer-common.o $(addsuffix .lo, $(basename $(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)
@@ -149,7 +166,8 @@ clean:
 # avoid old build problems by removing potentially incorrect old files
 	rm -f config.mak op-i386.h opc-i386.h gen-op-i386.h op-arm.h opc-arm.h gen-op-arm.h
 	rm -f qemu-options.def
-	rm -f *.o *.d *.a $(TOOLS) TAGS cscope.* *.pod *~ */*~
+	rm -f *.o *.d *.a *.lo $(TOOLS) TAGS cscope.* *.pod *~ */*~
+	rm -Rf .libs
 	rm -f slirp/*.o slirp/*.d audio/*.o audio/*.d block/*.o block/*.d net/*.o net/*.d fsdev/*.o fsdev/*.d ui/*.o ui/*.d
 	rm -f qemu-img-cmds.h
 	rm -f trace.c trace.h trace.c-timestamp trace.h-timestamp
diff --git a/Makefile.objs b/Makefile.objs
index 52d8b23045..f617ed5b7e 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -347,6 +347,14 @@ trace-dtrace.dtrace-timestamp: $(SRC_PATH)/trace-events config-host.mak
 trace-dtrace.o: trace-dtrace.dtrace $(GENERATED_HEADERS)
 	$(call quiet-command,dtrace -o $@ -G -s $<, "  GEN trace-dtrace.o")
 
+ifeq ($(LIBTOOL),)
+trace-dtrace.lo: trace-dtrace.dtrace
+	@echo "missing libtool. please install and rerun configure."; exit 1
+else
+trace-dtrace.lo: trace-dtrace.dtrace
+	$(call quiet-command,libtool --mode=compile --tag=CC dtrace -o $@ -G -s $<, "  lt GEN trace-dtrace.o")
+endif
+
 simpletrace.o: simpletrace.c $(GENERATED_HEADERS)
 
 ifeq ($(TRACE_BACKEND),dtrace)
diff --git a/configure b/configure
index 767c3831f4..a6e9d1c85a 100755
--- a/configure
+++ b/configure
@@ -1280,6 +1280,15 @@ if ! has $pkg_config; then
 fi
 
 ##########################################
+# libtool probe
+
+if ! has libtool; then
+    libtool=
+else
+    libtool=libtool
+fi
+
+##########################################
 # Sparse probe
 if test "$sparse" != "no" ; then
   if has cgcc; then
@@ -3047,6 +3056,7 @@ echo "AR=$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" >> $config_host_mak
@@ -3580,7 +3590,7 @@ if [ "$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 1d34df0004..9802c37ee8 100644
--- a/libcacard/Makefile
+++ b/libcacard/Makefile
@@ -4,15 +4,39 @@
 
 $(call set-vpath, $(SRC_PATH):$(SRC_PATH)/libcacard)
 
-QEMU_OBJS=$(addprefix ../, $(oslib-obj-y) $(trace-obj-y) qemu-malloc.o qemu-timer-common.o)
+# objects linked against normal qemu binaries, not compiled with libtool
+QEMU_OBJS=$(addprefix ../,$(oslib-obj-y) qemu-malloc.o qemu-timer-common.o $(trace-obj-y))
+
+# objects linked into a shared library, built with libtool with -fPIC if required
+QEMU_OBJS_LIB=$(addsuffix .lo,$(basename $(QEMU_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 *.lo .libs/* *.la
+	rm -Rf .libs
 
 all: vscclient
 
-clean:
-	rm -f *.o */*.o *.d */*.d *.a */*.a *~ */*~ vscclient
+#########################################################################
+# Rules for building libcacard standalone library
+
+ifeq ($(LIBTOOL),)
+libcacard.la:
+	@echo "libtool is missing, please install and rerun configure"; exit 1
+
+install-libcacard:
+	@echo "libtool is missing, please install and rerun configure"; exit 1
+else
+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
diff --git a/rules.mak b/rules.mak
index ed59c9e82b..612ae37093 100644
--- a/rules.mak
+++ b/rules.mak
@@ -17,6 +17,14 @@ QEMU_DGFLAGS += -MMD -MP -MT $@ -MF $(*D)/$(*F).d
 %.o: %.c
 	$(call quiet-command,$(CC) $(QEMU_CFLAGS) $(QEMU_INCLUDES) $(QEMU_DGFLAGS) $(CFLAGS) -c -o $@ $<,"  CC    $(TARGET_DIR)$@")
 
+ifeq ($(LIBTOOL),)
+%.lo: %.c
+	@echo "missing libtool. please install and rerun configure"; exit 1
+else
+%.lo: %.c
+	$(call quiet-command,libtool --mode=compile --quiet --tag=CC $(CC) $(QEMU_CFLAGS) $(QEMU_INCLUDES) $(QEMU_DGFLAGS) $(CFLAGS) -c -o $@ $<,"  lt CC $@")
+endif
+
 %.o: %.S
 	$(call quiet-command,$(CC) $(QEMU_CFLAGS) $(QEMU_INCLUDES) $(QEMU_DGFLAGS) $(CFLAGS) -c -o $@ $<,"  AS    $(TARGET_DIR)$@")