Merge pull request #9581 from bwbarrett/feature/mpi-ext-know-if-selected

Add post_config hook for MPI extensions

Author: bosilca

config/ompi_ext.m4

@@ -34,6 +34,9 @@ AC_DEFUN([OMPI_EXT],[
     dnl for OPAL_CONFIGURE_USER env variable
     AC_REQUIRE([OPAL_CONFIGURE_SETUP])
 
+    m4_ifdef([ompi_mpiext_list], [],
+             [m4_fatal([Could not find MPI Extensions list.  Aborting.])])
+
     # Note that we do not build DSO's here -- we *only* build convenience
     # libraries that get slurped into higher-level libraries
     #
@@ -42,7 +45,7 @@ AC_DEFUN([OMPI_EXT],[
     #
     AC_ARG_ENABLE([mpi-ext],
         [AS_HELP_STRING([--enable-mpi-ext[=LIST]],
-                       [Comma-separated list of extensions that should be built.  Possible values: ompi_mpiext_list.  Example: "--enable-mpi-ext=foo,bar" will enable building the MPI extensions "foo" and "bar".  If LIST is empty or the special value "all", then all available MPI extensions will be built (default: all).])])
+                       [Comma-separated list of extensions that should be built.  Possible values: ]m4_quote(ompi_mpiext_list)[.  Example: "--enable-mpi-ext=foo,bar" will enable building the MPI extensions "foo" and "bar".  If LIST is empty or the special value "all", then all available MPI extensions will be built (default: all).])])
 
     # print some nice messages about what we're about to do...
     AC_MSG_CHECKING([for available MPI Extensions])
@@ -74,9 +77,6 @@ AC_DEFUN([OMPI_EXT],[
     AC_MSG_RESULT([$msg])
     unset msg
 
-    m4_ifdef([ompi_mpiext_list], [],
-             [m4_fatal([Could not find MPI Extensions list.  Aborting.])])
-
     EXT_CONFIGURE
 ])
 
@@ -390,6 +390,9 @@ AC_DEFUN([EXT_CONFIGURE_M4_CONFIG_COMPONENT],[
     AS_IF([test $should_build -eq 1],
           [EXT_PROCESS_COMPONENT([$1], [$2], [$3], [$4], [$5], [$6], [$7])],
           [EXT_PROCESS_DEAD_COMPONENT([$1], [$2])])
+
+    m4_ifdef([OMPI_MPIEXT_$1_POST_CONFIG],
+             [OMPI_MPIEXT_$1_POST_CONFIG($should_build)])
 ])
 
 ######################################################################

ompi/mpiext/example/configure.m4

@@ -55,3 +55,12 @@ AC_DEFUN([OMPI_MPIEXT_example_NEED_INIT], [1])
 # libraries for any of the bindings.  If finer-grained control is needed
 # someday, we may need to split this into multiple macros.
 #AC_DEFUN([OMPI_MPIEXT_example_HAVE_OBJECT], [0])
+
+# This is a hook that runs after the CONFIG macro and after the
+# configure system decides if this extension will be built (such
+# as if it was disabled by configure option).  This is a great
+# place to put any globally-visible AC_DEFINE or AM_CONDITIONAL
+# macros that are based on this component building.
+AC_DEFUN([OMPI_MPIEXT_example_POST_CONFIG], [
+  opal_show_verbose "example component build result: $1"
+])