Add a check for -ldl, stolen from xorg-server's configure.ac.

Signed-off-by: Nicolas Chauvet <kwizart@gmail.com>

configure.ac

@@ -20,6 +20,12 @@ PKG_CHECK_MODULES(X11, x11)
 AC_SUBST(X11_CFLAGS)
 AC_SUBST(X11_LIBS)
 
+dnl Check to see if dlopen is in default libraries (like Solaris, which
+dnl has it in libc), or if libdl is needed to get it.
+AC_CHECK_FUNC([dlopen], [],
+        AC_CHECK_LIB([dl], [dlopen], DLOPEN_LIBS="-ldl"))
+AC_SUBST([DLOPEN_LIBS])
+
 AC_OUTPUT([Makefile
            src/Makefile
            trace/Makefile

src/Makefile.am

@@ -7,6 +7,9 @@ lib_LTLIBRARIES = libvdpau.la
 libvdpau_la_SOURCES = \
     vdpau_wrapper.c
 
+libvdpau_la_LIBADD = \
+    $(DLOPEN_LIBS)
+
 libvdpau_la_LDFLAGS = -version-info 1:0:0 -no-undefined
 
 libvdpauincludedir = $(includedir)/vdpau

trace/Makefile.am

@@ -7,6 +7,9 @@ lib_LTLIBRARIES = libvdpau_trace.la
 libvdpau_trace_la_SOURCES = \
     vdpau_trace.cpp
 
+libvdpau_trace_la_LIBADD = \
+    $(DLOPEN_LIBS)
+
 libvdpau_trace_la_LDFLAGS = -avoid-version -module -no-undefined
 
 libvdpau_traceincludedir = $(includedir)/vdpau