opa2: improve autoconf tests

configure.ac

@@ -317,7 +317,6 @@ OPTION_DEFAULT_ENABLE([tsampler], [ENABLE_TSAMPLER])
 OPTION_DEFAULT_ENABLE([cray_power_sampler], [ENABLE_CRAY_POWER_SAMPLER])
 dnl cray_power_sampler won't build with --disable-tsampler
 
-OPTION_DEFAULT_DISABLE([opa2], [ENABLE_OPA2])
 OPTION_DEFAULT_ENABLE([loadavg], [ENABLE_LOADAVG])
 OPTION_DEFAULT_ENABLE([vmstat], [ENABLE_VMSTAT])
 OPTION_DEFAULT_ENABLE([procdiskstats], [ENABLE_PROCDISKSTATS])
@@ -451,6 +450,18 @@ AS_IF([test "$enable_ibnet" = xyes],[
 		[AC_MSG_ERROR([ibnet required <infiniband/complib/cl_nodenamemap.h> not found ])])
 ])
 
+AC_ARG_ENABLE([opa2],
+	[AS_HELP_STRING([--enable-opa2], [require the opa2 plugin @<:@default=check@:>@])],
+	[],
+	[enable_opa2="check"])
+AM_CONDITIONAL([ENABLE_OPA2], [test "xenable_opa2" != xno])
+AS_IF([test "x$enable_opa2" = xyes],[
+	AS_IF([test "x$HAVE_LIBIBMAD" = xno],
+		[AC_MSG_ERROR([opa2 required libibmad or <infiniband/mad.h> not found])])
+	AS_IF([test "x$HAVE_LIBIBUMAD" = xno],
+		[AC_MSG_ERROR([opa2 required libibumad or <infiniband/umad.h> not found])])
+])
+
 # enable tx2mon by default only when sensible.
 AC_ARG_ENABLE([tx2mon],
 	[AS_HELP_STRING([--enable-tx2mon], [require components that depend upon tx2mon header) @<:@default=check@:>@])],

ldms/src/sampler/Makefile.am

@@ -286,13 +286,16 @@ endif
 endif
 
 if ENABLE_OPA2
-OPA2_LIBADD = -libmad -libumad -lpthread
+if HAVE_LIBIBMAD
+if HAVE_LIBIBUMAD
+OPA2_LIBADD = $(LTLIBIBMAD) $(LTLIBIBUMAD) -lpthread
 libopa2_la_SOURCES = opa2.c
-OPAINC=/usr/include/infiniband
-libopa2_la_CFLAGS = $(AM_CFLAGS) -I$(OPAINC)
+libopa2_la_CFLAGS = $(AM_CFLAGS) -I/usr/include/infiniband
 libopa2_la_LIBADD = $(AM_LDFLAGS) $(COMMON_LIBADD) $(OPA2_LIBADD) $(JOBID_LIBFLAGS)
 pkglib_LTLIBRARIES += libopa2.la
 endif
+endif
+endif
 
 if ENABLE_ATASMART
 libsampler_atasmart_la_SOURCES = sampler_atasmart.c