[lttng-dev] [PATCH lttng-ust] Fix linking failure when cross-compiling

[Adrien Vergé]

Examples binaries in doc/examples require libs in liblttng-ust/.libs/,
and those libs require other libs in the same directory.  For instance
liblttng-ust.so uses liblttng-ust-tracepoint.so symbols, so the latter
is needed to properly link example programs.  Currently, ld is given
the lib dir only via -rpath (used for linking executables dependencies)
but not via -rpath-link (used for linking libs dependencies).

When compiling regularly, this does not seem to be a problem (maybe ld
is smart enough).  However when cross-compiling with the
arm-linux-gnueabihf toolchain, -rpath-link is needed otherwise linking
fails with:

arm-linux-gnueabihf/bin/ld: warning: liblttng-ust-tracepoint.so.0, needed by ../../../liblttng-ust/.libs//liblttng-ust.so, not found (try using -rpath or -rpath-link)

This patch adds -rpath-link to doc/examples/Makefile.am.

Signed-off-by: Adrien Vergé <adrienverge at gmail.com>
---
 doc/examples/Makefile.am | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/examples/Makefile.am b/doc/examples/Makefile.am
index 1fd0084..0690597 100644
--- a/doc/examples/Makefile.am
+++ b/doc/examples/Makefile.am
@@ -75,7 +75,7 @@ all-local:
 		rel_build_subdir="../"; \
 	fi; \
 	for subdir in $(SUBDIRS_PROXY); do \
-		(cd $$subdir && $(MAKE) AM_CC="$(CC)" AM_CPPFLAGS="$(CPPFLAGS) -I$$rel_src_subdir$(top_srcdir)/include/ -I$$rel_build_subdir$(top_builddir)/include/" AM_CFLAGS='$(CFLAGS)' AM_LDFLAGS='$(LDFLAGS) -L../../../liblttng-ust/.libs/ -Wl,-rpath="$(PWD)/../../liblttng-ust/.libs/"' LTTNG_GEN_TP_PATH="../../../tools/" $(AM_MAKEFLAGS) all && cd ..) || exit 1; \
+		(cd $$subdir && $(MAKE) AM_CC="$(CC)" AM_CPPFLAGS="$(CPPFLAGS) -I$$rel_src_subdir$(top_srcdir)/include/ -I$$rel_build_subdir$(top_builddir)/include/" AM_CFLAGS='$(CFLAGS)' AM_LDFLAGS='$(LDFLAGS) -L../../../liblttng-ust/.libs -Wl,-rpath="$(PWD)/../../liblttng-ust/.libs/" -Wl,-rpath-link="$(PWD)/../../liblttng-ust/.libs/"' LTTNG_GEN_TP_PATH="../../../tools/" $(AM_MAKEFLAGS) all && cd ..) || exit 1; \
 	done; \
 	if [ x"$(SUBDIRS_JUL)" != x"" ]; then \
 		for subdir in $(SUBDIRS_JUL); do \
-- 
1.9.1