build: libgfxdr.so calls GF_FREE(), needs to link with -lglusterfs

The previous change to remove the xdrgen script exposed (or
created) a recursive build dependency: libglusterfs needs the
generated headers, and libgfxdr should be linked with libglusterfs
for GF_FREE/__gf_free.

(Much grumbling about libglusterfs being the kitchen sink of gluster
elided. This would not be necessary if there were two or more libs,
a gluster "runtime" library with common gluster code shared by the
xlators and daemons, and a utility library with things like the
rbtree, memory allocation, and whatnot.)

So. Link at build time or link at runtime? For truth-and-beauty, link
with libglusterfs.so at build time. Without truth-and-beauty, don't
link with libglusterfs and rely on the other things that link with
libglusterfs to provide resolution of __gf_free().

Truth-and-beauty it is. But how to generate the headers first, then
build libglusterfs, then come back and build libgfxdr? Autotools is a
maze of twisty passages, all different. Things that work with gnu
make on linux don't work with the BSD make. Finally I hit on this
solution. Add a shadow directory where make only generates the headers,
then build libglusterfs using the generated headers, and finally build
libgfxdr and link with libglusterfs.

See original BZ 1330604
change http://review.gluster.org/14085

Change-Id: Iede8a30e3103176cb8f0b054885f30fcb352492b
BUG: 1429696
Signed-off-by: Kaleb S. KEITHLEY <kkeithle@redhat.com>
Reviewed-on: https://review.gluster.org/16873
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Smoke: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Niels de Vos <ndevos@redhat.com>

1 files changed, 48 insertions, 0 deletions

diff --git a/rpc/xdr/gen/Makefile.am b/rpc/xdr/gen/Makefile.am
new file mode 100644
index 00000000000..fc6973c1821
--- /dev/null
+++ b/rpc/xdr/gen/Makefile.am
@@ -0,0 +1,48 @@
+XDRGENFILES = glusterfs3-xdr.x cli1-xdr.x nlm4-xdr.x nsm-xdr.x \
+	rpc-common-xdr.x glusterd1-xdr.x acl3-xdr.x portmap-xdr.x \
+	mount3udp.x changelog-xdr.x glusterfs-fops.x
+XDRHEADERS = $(XDRGENFILES:.x=.h)
+XDRSOURCES = $(XDRGENFILES:.x=.c)
+
+CLEANFILES = $(XDRSOURCES) $(XDRHEADERS)
+
+# trick automake into doing BUILT_SOURCES magic
+BUILT_SOURCES = $(XDRHEADERS) $(XDRSOURCES)
+
+xdrsrc=$(top_srcdir)/rpc/xdr/src
+
+# make's dependency resolution may mean that it decides to run
+# rpcgen again (unnecessarily), but as the .c file already exists,
+# rpcgen will exit with an error, resulting in a build error. We
+# could use a '-' (i.e. -@rpcgen ...) and suffer with noisy warnings
+# in the build. Or we do this crufty thing instead.
+$(XDRSOURCES): $(XDRGENFILES)
+	if [ ! -e $@ -o $(@:.c=.x) -nt $@ ]; then \
+		rpcgen -c -o $(@:.c=.tmp) $(@:.c=.x) && mv $(@:.c=.tmp) $@ ; \
+		cp $@ $(xdrsrc)/ ;\
+	fi
+
+# d*mn sed in netbsd6 doesn't do -i (inline)
+# (why are we still running smoke on netbsd6 and not netbsd7?)
+$(XDRHEADERS): $(XDRGENFILES)
+	if [ ! -e $@ -o $(@:.h=.x) -nt $@ ]; then \
+		rpcgen -h -o $(@:.h=.tmp) $(@:.h=.x) ; \
+		sed -e '/#ifndef/ s/-/_/g' -e '/#define/ s/-/_/g' -e '/#endif/ s/-/_/' \
+			$(@:.h=.tmp) > $@ && rm -f $(@:.h=.tmp) ; \
+		cp $@ $(xdrsrc)/ ; \
+	fi
+
+
+# link .x files when doing out-of-tree builds
+# have to use .PHONY here to force it; all versions of make
+# will think the file already exists "here" by virtue of the
+# VPATH. And we have to have the .x file in $cwd in order to
+# have rpcgen generate "nice" #include directives
+# i.e. (nice):
+# #include "acl3-xdr.h"
+# versus (not nice):
+# #include "../../../../foo/src/rpc/xdr/src/acl3-xdr.h"
+.PHONY : $(XDRGENFILES)
+$(XDRGENFILES):
+	@if [ ! -e $@ ]; then ln -s $(xdrsrc)/$@ . ; fi;
+