On Fri, 09/06 12:09, Paolo Bonzini wrote:
> Il 06/09/2013 09:28, Fam Zheng ha scritto:
> > Add necessary rules and flags for shared object generation.
> > $(common-obj-m) will include $(block-obj-m), like $(common-obj-y) does
> > for $(block-obj-y). The new rules introduced here are:
> >
> > 0) For all %.so compiling:
> >
> > QEMU_CFLAGS += -shared -fPIC
> >
> > 1) %.o in $(common-obj-m) is compiled to %.o, with "QEMU_CFLAGS +=
> > -shared -fPIC". Then linked to %.so.
> >
> > 2) %.mo in $(common-obj-m) is the placeholder for %.so for pattern
> > matching in Makefile. It's linked to "-shared" with all its dependencies
> > (multiple *.o) as input. Which means the list of depended objects must
> > be ruled out in each sub-Makefile.objs with an variable:
> >
> > $(obj)/foo.mo-obj := $(addprefix $(obj)/,bar.o baz.o qux.o)
> >
> > Notice that $(obj)/ is required for both target and dependency in the
> > rule. DSO suffix (.so) is configure variable (.dll for Windows).
>
> Some kinks to iron, but this is really well-architected. You took all
> the best parts of mjt's patches and fixed almost all the ugly ones. Kudos!
>
> > Signed-off-by: Fam Zheng <f...@redhat.com>
> > ---
> > Makefile | 32 +++++++++++++++++++++++++++++---
> > Makefile.objs | 14 +++++++++++++-
> > configure | 3 +++
> > rules.mak | 10 ++++++++++
> > 4 files changed, 55 insertions(+), 4 deletions(-)
> >
> > diff --git a/Makefile b/Makefile
> > index 806946e..cf47ea9 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -56,7 +56,7 @@ Makefile: ;
> > configure: ;
> >
> > .PHONY: all clean cscope distclean dvi html info install install-doc \
> > - pdf recurse-all speed test dist
> > + pdf recurse-all speed test dist modules
> >
> > $(call set-vpath, $(SRC_PATH))
> >
> > @@ -121,7 +121,30 @@ ifeq ($(CONFIG_SMARTCARD_NSS),y)
> > include $(SRC_PATH)/libcacard/Makefile
> > endif
> >
> > -all: $(DOCS) $(TOOLS) $(HELPERS-y) recurse-all
> > +all: $(DOCS) $(TOOLS) $(HELPERS-y) recurse-all modules
> > +
> > +mod-obj-m = $(patsubst %.o,%$(DSOSUF),$(filter %.o,$(common-obj-m))) \
> > + $(patsubst %.mo,%$(DSOSUF),$(filter %.mo,$(common-obj-m)))
>
>
> Why common-obj-m only, what about block-obj-m?
>
Because common-obj-m = $(block-obj-m), in Makefile.objs below.
> Perhaps adding to mod-obj-m (better name: modules-m) can be done in
> unnest-vars?
It looks more straightforward for me to do here, and it's used very locally.
>
> > +# Generate rules for single file modules (%.so: %.o).
> > +$(foreach o,$(filter %.o,$(common-obj-m)),$(eval \
> > + $(patsubst %.o,%.so,$o): $o ))
>
> If you subst %.o to %.mo, you can use the same set of rules for both cases.
>
> > +# For multi file modules, dependencies should be listed explicitly in
> > +# Makefile.objs as
> > +# $(obj)/foo.mo-obj := $(obj)/bar.o $(obj)/biz.o
>
> Why not
>
> $(obj)/foo.mo: $(obj)/bar.o $(obj)/biz.o
>
> ?
>
Because I don't know how to expand foo.mo to bar.o and biz.o: I expand "foo.mo"
to "bar.o biz.o" in the link command line, to skip creating to foo.mo, or
libfoo.a, if it's to be linked static:
block-obj-y += foo.mo
That's for avoiding ar and ln -r.
> > +$(foreach o,$(filter %.mo,$(mod-obj-m)),$(eval \
> > + $o: $($o-obj)))
> > +
> > +%.mo:
> > + $(if $(BUILD_DYNAMIC), \
> > + $(call quiet-command,$(CC) $(sort $^) -shared -o $@," LD[M]
> > $(TARGET_DIR)$@"), \
> > + $(call quiet-command,$(AR) rcs $@ $(sort $^)," AR
> > $(TARGET_DIR)$@"))
>
> I think we can always build modules dynamically. If the
> module/no-module configure option decides whether an object moves
> between *-obj-y and *-obj-m, statically-linked modules will just go on
> the linker command line with no need for $(AR) or
> --whole-archive/--no-whole-archive.
>
I don't understand, do you mean a "cc -shared" output can be statically linked
into a executable?
> I'm missing where is the .so built (or I guess it can just be
> hard-linked?) from the .mo file.
>
> IIRC -shared is not portable to Darwin. Darwin has separate file
> formats for dynamic libraries (.dylib) and loadable modules (.so), so it
> needs "-bundle" instad. All this screams "just use libtool"...
>
> > +
> > +
> > +modules: $(mod-obj-m)
> > +modules: BUILD_DYNAMIC = 1
> > +modules: QEMU_CFLAGS += -shared -fPIC
>
> -shared is not needed here, only -fPIC. Again, libtool would abstract
> this nicely. But it's fine if you prefer to have v3 still without
> libtool and only working on ELF systems.
>
> In fact, you probably don't need a special modules target. You can just
> add $(mod-obj-m) to "all".
>
> >
> > config-host.h: config-host.h-timestamp
> > config-host.h-timestamp: config-host.mak
> > @@ -155,7 +178,7 @@ subdir-dtc:dtc/libfdt dtc/tests
> > dtc/%:
> > mkdir -p $@
> >
> > -$(SUBDIR_RULES): libqemuutil.a libqemustub.a $(common-obj-y)
> > +$(SUBDIR_RULES): libqemuutil.a libqemustub.a $(common-obj-y)
> > $(common-obj-m)
> >
> > ROMSUBDIR_RULES=$(patsubst %,romsubdir-%, $(ROMS))
> > romsubdir-%:
> > @@ -235,6 +258,9 @@ clean:
> > rm -f qemu-options.def
> > find . -name '*.[oda]' -type f -exec rm -f {} +
> > find . -name '*.l[oa]' -type f -exec rm -f {} +
> > + find . -name '*'$(DSOSUF) -type f -exec rm -f {} +
> > + find . -name '*.mo' -type f -exec rm -f {} +
> > +
> > rm -f $(TOOLS) $(HELPERS-y) qemu-ga TAGS cscope.* *.pod *~ */*~
> > rm -Rf .libs
> > rm -f qemu-img-cmds.h
> > diff --git a/Makefile.objs b/Makefile.objs
> > index f46a4cd..8984a20 100644
> > --- a/Makefile.objs
> > +++ b/Makefile.objs
> > @@ -19,6 +19,8 @@ block-obj-y += qemu-coroutine.o qemu-coroutine-lock.o
> > qemu-coroutine-io.o
> > block-obj-y += qemu-coroutine-sleep.o
> > block-obj-y += coroutine-$(CONFIG_COROUTINE_BACKEND).o
> >
> > +block-obj-m = block/
> > +
> > ifeq ($(CONFIG_VIRTIO)$(CONFIG_VIRTFS)$(CONFIG_PCI),yyy)
> > # Lots of the fsdev/9pcode is pulled in by vl.c via qemu_fsdev_add.
> > # only pull in the actual virtio-9p device if we also enabled virtio.
> > @@ -83,6 +85,9 @@ common-obj-$(CONFIG_SMARTCARD_NSS) += $(libcacard-y)
> >
> > common-obj-y += qmp-marshal.o
> > common-obj-y += qmp.o hmp.o
> > +
> > +common-obj-m = $(block-obj-m)
> > +
> > endif
> >
> > ######################################################################
> > @@ -121,5 +126,12 @@ nested-vars += \
> > util-obj-y \
> > qga-obj-y \
> > block-obj-y \
> > - common-obj-y
> > + block-obj-m \
> > + common-obj-y \
> > + common-obj-m
> > +
> > dummy := $(call unnest-vars)
> > +
> > +# static linked mods are expanded to .o list
> > +dummy := $(call expand-mod-obj,common-obj-y)
> > +dummy := $(call expand-mod-obj,block-obj-y)
> > diff --git a/configure b/configure
> > index af6b048..75abb87 100755
> > --- a/configure
> > +++ b/configure
> > @@ -190,6 +190,7 @@ mingw32="no"
> > gcov="no"
> > gcov_tool="gcov"
> > EXESUF=""
> > +DSOSUF=".so"
> > prefix="/usr/local"
> > mandir="\${prefix}/share/man"
> > datadir="\${prefix}/share"
> > @@ -584,6 +585,7 @@ fi
> >
> > if test "$mingw32" = "yes" ; then
> > EXESUF=".exe"
> > + DSOSUF=".dll"
> > QEMU_CFLAGS="-DWIN32_LEAN_AND_MEAN -DWINVER=0x501 $QEMU_CFLAGS"
> > # enable C99/POSIX format strings (needs mingw32-runtime 3.15 or later)
> > QEMU_CFLAGS="-D__USE_MINGW_ANSI_STDIO=1 $QEMU_CFLAGS"
> > @@ -4175,6 +4177,7 @@ echo "LIBTOOLFLAGS=$LIBTOOLFLAGS" >> $config_host_mak
> > echo "LIBS+=$LIBS" >> $config_host_mak
> > echo "LIBS_TOOLS+=$libs_tools" >> $config_host_mak
> > echo "EXESUF=$EXESUF" >> $config_host_mak
> > +echo "DSOSUF=$DSOSUF" >> $config_host_mak
> > echo "LIBS_QGA+=$libs_qga" >> $config_host_mak
> > echo "POD2MAN=$POD2MAN" >> $config_host_mak
> > echo "TRANSLATE_OPT_CFLAGS=$TRANSLATE_OPT_CFLAGS" >> $config_host_mak
> > diff --git a/rules.mak b/rules.mak
> > index e581d55..0a39499 100644
> > --- a/rules.mak
> > +++ b/rules.mak
> > @@ -58,6 +58,10 @@ endif
> > %.o: %.dtrace
> > $(call quiet-command,dtrace -o $@ -G -s $<, " GEN $(TARGET_DIR)$@")
> >
> > +%$(DSOSUF): QEMU_CLFAGS += -shared -fPIC
> > +%$(DSOSUF): %.o
> > + $(call quiet-command,$(LD) $< -o $@ -shared," LD[M] $(TARGET_DIR)$@")
> > +
>
> As mentioned above, I think these four lines are not needed and you can
> always go through the "modules" or $(mod-obj-m) targets. In fact,
> CLFAGS sounds dubious. :)
>
> Paolo
>
> > %$(EXESUF): %.o
> > $(call LINK,$^)
> >
> > @@ -145,3 +149,9 @@ $(shell mkdir -p $(sort $(foreach
> > var,$(nested-vars),$(dir $($(var))))))
> > $(foreach var,$(nested-vars), $(eval \
> > -include $(addsuffix *.d, $(sort $(dir $($(var)))))))
> > endef
> > +
> > +define expand-mod-obj
> > +$(eval pref = $(if $(obj-base),$(obj-base)/,))
> > +$(eval t = $(foreach o,$($1),$(if $($(pref)$o-obj),$($(pref)$o-obj),$o)))
> > +$(eval $1 = $t)
> > +endef
> >
>
