opal_check_libfabric.m4: add libfabric m4 macro

Similar to other m4 macros checking for the existence / usability of
external libraries.

config/opal_check_libfabric.m4

@@ -0,0 +1,83 @@
+dnl -*- shell-script -*-
+dnl
+dnl Copyright (c) 2015 Cisco Systems, Inc.  All rights reserved.
+dnl $COPYRIGHT$
+dnl
+dnl Additional copyrights may follow
+dnl
+dnl $HEADER$
+dnl
+
+
+# OPAL_CHECK_LIBFABRIC(prefix, [action-if-found], [action-if-not-found]
+# --------------------------------------------------------
+# Check if libfabric support can be found.
+#
+# Sets prefix_{CPPFLAGS, LDFLAGs, LIBS} as needed and runs
+# action-if-found if there is support; otherwise executes
+# action-if-not-found.
+#
+AC_DEFUN([OPAL_CHECK_LIBFABRIC],[
+    OPAL_VAR_SCOPE_PUSH([opal_check_libfabric_$1_save_CPPFLAGS opal_check_libfabric_$1_save_LDFLAGS opal_check_libfabric_$1_save_LIBS])
+
+    # Add --with options
+    AC_ARG_WITH([libfabric],
+        [AC_HELP_STRING([--with-libfabric=DIR],
+             [Specify location of libfabric installation, adding DIR/include to the default search location for libfabric headers, and DIR/lib or DIR/lib64 to the default search location for libfabric libraries.  Error if libfabric support cannot be found.])])
+    AC_ARG_WITH([libfabric-libdir],
+       [AC_HELP_STRING([--with-libfabric-libdir=DIR],
+             [Search for libfabric libraries in DIR])])
+
+    # Sanity check the --with values
+    OPAL_CHECK_WITHDIR([libfabric], [$with_libfabric],
+                       [include/rdma/fabric.h])
+    OPAL_CHECK_WITHDIR([libfabric-libdir], [$with_libfabric_libdir],
+                       [libfabric.*])
+
+    opal_check_libfabric_$1_save_CPPFLAGS=$CPPFLAGS
+    opal_check_libfabric_$1_save_LDFLAGS=$LDFLAGS
+    opal_check_libfabric_$1_save_LIBS=$LIBS
+
+    opal_check_libfabric_happy=1
+    AS_IF([test "$with_libfabric" = "no"],
+          [opal_check_libfabric_happy=0])
+
+    AS_IF([test $opal_check_libfabric_happy -eq 1],
+          [AC_MSG_CHECKING([looking for libfabric in])
+           AS_IF([test "$with_libfabric" != "yes"],
+                 [opal_libfabric_dir=$with_libfabric
+                  AC_MSG_RESULT([($opal_libfabric_dir)])],
+                 [AC_MSG_RESULT([(default search paths)])])
+           AS_IF([test ! -z "$with_libfabric_libdir" && \
+                  test "$with_libfabric_libdir" != "yes"],
+                 [opal_libfabric_libdir=$with_libfabric_libdir])
+          ])
+
+    AS_IF([test $opal_check_libfabric_happy -eq 1],
+        [OPAL_CHECK_PACKAGE([$1],
+                            [rdma/fabric.h],
+                            [fabric],
+                            [fi_getinfo],
+                            [],
+                            [$opal_libfabric_dir],
+                            [$opal_libfabric_libdir],
+                            [opal_check_libfabric_happy=1],
+                            [opal_check_libfabric_happy=0])])
+
+    CPPFLAGS=$opal_check_libfabric_$1_save_CPPFLAGS
+    LDFLAGS=$opal_check_libfabric_$1_save_LDFLAGS
+    LIBS=$opal_check_libfabric_$1_save_LIBS
+
+    AC_SUBST($1_CPPFLAGS)
+    AC_SUBST($1_LDFLAGS)
+    AC_SUBST($1_LIBS)
+
+    AS_IF([test $opal_check_libfabric_happy -eq 1],
+          [$2],
+          [AS_IF([test "$opal_want_libfabric" = "yes"],
+                 [AC_MSG_WARN([libfabric support requested (via --with-libfabric), but not found.])
+                  AC_MSG_ERROR([Cannot continue.])])
+           $3])
+
+    OPAL_VAR_SCOPE_POP
+])dnl