RFC: Replace libltdl with OPAL "dl" framework

README

@@ -8,7 +8,7 @@ Copyright (c) 2004-2008 High Performance Computing Center Stuttgart,
                         University of Stuttgart.  All rights reserved.
 Copyright (c) 2004-2007 The Regents of the University of California.
                         All rights reserved.
-Copyright (c) 2006-2014 Cisco Systems, Inc.  All rights reserved.
+Copyright (c) 2006-2015 Cisco Systems, Inc.  All rights reserved.
 Copyright (c) 2006-2011 Mellanox Technologies. All rights reserved.
 Copyright (c) 2006-2012 Oracle and/or its affiliates.  All rights reserved.
 Copyright (c) 2007      Myricom, Inc.  All rights reserved.
@@ -1977,6 +1977,7 @@ backtrace   - Debugging call stack backtrace support
 compress    - Compression algorithms
 crs         - Checkpoint and restart service
 db          - Internal database support
+dl          - Dynamic loading library interface
 event       - Event library (libevent) versioning support
 hwloc       - Hardware locality (hwloc) versioning support
 if          - OS IP interface support

autogen.pl

@@ -1,6 +1,6 @@
 #!/usr/bin/env perl
 #
-# Copyright (c) 2009-2014 Cisco Systems, Inc.  All rights reserved.
+# Copyright (c) 2009-2015 Cisco Systems, Inc.  All rights reserved.
 # Copyright (c) 2010      Oracle and/or its affiliates.  All rights reserved.
 # Copyright (c) 2013      Mellanox Technologies, Inc.
 #                         All rights reserved.
@@ -1265,7 +1265,6 @@ sub patch_autotools_output {
 verbose "==> Remove stale files\n";
 find_and_delete(qw/config.guess config.sub depcomp compile install-sh ltconfig
     ltmain.sh missing mkinstalldirs libtool/);
-system("rm -rf opal/libltdl");
 
 # Remove the old m4 file and write the new one
 verbose "==> Writing m4 file with autogen.pl results\n";
@@ -1292,26 +1291,6 @@ sub patch_autotools_output {
 
 #---------------------------------------------------------------------------
 
-# For FreeBSD (carried over from autogen.sh); apparently some versions
-# of automake don't so this (prior to 1.9.7...?).
-system("chmod u+w opal/libltdl/configure");
-
-#---------------------------------------------------------------------------
-
-++$step;
-verbose "\n$step. Patching autotools output on top-level tree :-(\n\n";
-
-# Patch preopen error in libltdl
-if (-f "opal/libltdl/loaders/preopen.c") {
-    verbose "=== Patching preopen error masking in libltdl\n";
-    safe_system("$patch_prog -N -p0 < config/libltdl-preopen-error.diff");
-    unlink("opal/libltdl/loaders/preopen.c.rej");
-}
-
-patch_autotools_output(".");
-
-#---------------------------------------------------------------------------
-
 verbose "
 ================================================
 Open MPI autogen: completed successfully.  w00t!

config/Makefile.am

@@ -9,7 +9,7 @@
 #                         University of Stuttgart.  All rights reserved.
 # Copyright (c) 2004-2005 The Regents of the University of California.
 #                         All rights reserved.
-# Copyright (c) 2006-2010 Cisco Systems, Inc.  All rights reserved.
+# Copyright (c) 2006-2015 Cisco Systems, Inc.  All rights reserved.
 # Copyright (c) 2010      Oracle and/or its affiliates.  All rights 
 #                         reserved.
 # Copyright (c) 2014      Intel, Inc. All rights reserved.
@@ -23,7 +23,6 @@
 EXTRA_DIST = \
         distscript.csh \
 	opal_get_version.m4sh \
-	libltdl-preopen-error.diff \
 	ltmain_pgi_tp.diff \
         opal_mca_priority_sort.pl
 

config/opal_check_cuda.m4

@@ -10,7 +10,7 @@ dnl Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
 dnl                         University of Stuttgart.  All rights reserved.
 dnl Copyright (c) 2004-2005 The Regents of the University of California.
 dnl                         All rights reserved.
-dnl Copyright (c) 2006-2010 Cisco Systems, Inc.  All rights reserved.
+dnl Copyright (c) 2006-2015 Cisco Systems, Inc.  All rights reserved.
 dnl Copyright (c) 2007      Sun Microsystems, Inc.  All rights reserved.
 dnl Copyright (c) 2009      IBM Corporation.  All rights reserved.
 dnl Copyright (c) 2009      Los Alamos National Security, LLC.  All rights
@@ -72,10 +72,12 @@ AS_IF([test "$with_cuda" = "no" || test "x$with_cuda" = "x"],
                             opal_cuda_incdir="$with_cuda/include"
                             AC_MSG_RESULT([found ($opal_cuda_incdir/cuda.h)])])])])])
 
-# We cannot have CUDA support without dlopen support.  Check for that and
-# error out if the user has also set --disable-dlopen.
-AS_IF([test "$enable_dlopen" = "no" && test "$opal_check_cuda_happy" = "yes"],
-    [AC_MSG_ERROR([--with-cuda cannot be used with --disable-dlopen.  Remove one of them and reconfigure.])])
+dnl We cannot have CUDA support without dlopen support.  HOWEVER, at
+dnl this point in configure, we can't know whether the DL framework
+dnl has been configured or not yet (it likely hasn't, since CUDA is a
+dnl common framework, and likely configured first).  So we have to
+dnl defer this check until later (see the OPAL_CHECK_CUDA_AFTER_OPAL_DL m4
+dnl macro, below).  :-(
 
 # If we have CUDA support, check to see if we have CUDA 4.1 support
 AS_IF([test "$opal_check_cuda_happy"="yes"],
@@ -142,3 +144,21 @@ AC_DEFINE_UNQUOTED([OPAL_CUDA_GDR_SUPPORT],$CUDA_VERSION_60_OR_GREATER,
                    [Whether we have CUDA GDR support available])
 
 ])
+
+dnl
+dnl CUDA support requires DL support (it dynamically opens the CUDA
+dnl library at run time).  But we do not check for OPAL DL support
+dnl until lafter the initial OPAL_CHECK_CUDA is called.  So put the
+dnl CUDA+DL check in a separate macro that can be called after the DL MCA
+dnl framework checks in the top-level configure.ac.
+dnl
+AC_DEFUN([OPAL_CHECK_CUDA_AFTER_OPAL_DL],[
+
+    # We cannot have CUDA support without OPAL DL support.  Error out
+    # if the user wants CUDA but we do not have OPAL DL support.
+    AS_IF([test $OPAL_HAVE_DL_SUPPORT -eq 0 && \
+           test "$opal_check_cuda_happy" = "yes"],
+          [AC_MSG_WARN([--with-cuda was specified, but dlopen support is disabled.])
+           AC_MSG_WARN([You must reconfigure Open MPI with dlopen ("dl") support.])
+           AC_MSG_ERROR([Cannot continue.])])
+])

config/opal_configure_options.m4

@@ -10,7 +10,7 @@ dnl Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
 dnl                         University of Stuttgart.  All rights reserved.
 dnl Copyright (c) 2004-2005 The Regents of the University of California.
 dnl                         All rights reserved.
-dnl Copyright (c) 2006-2014 Cisco Systems, Inc.  All rights reserved.
+dnl Copyright (c) 2006-2015 Cisco Systems, Inc.  All rights reserved.
 dnl Copyright (c) 2007      Sun Microsystems, Inc.  All rights reserved.
 dnl Copyright (c) 2009      IBM Corporation.  All rights reserved.
 dnl Copyright (c) 2009      Los Alamos National Security, LLC.  All rights

configure.ac

@@ -1157,6 +1157,18 @@ m4_ifdef([project_ompi], [OMPI_REQUIRE_ENDPOINT_TAG_FINI])
 # checkpoint results
 AC_CACHE_SAVE
 
+##################################
+# CUDA: part two
+##################################
+
+# This is somewhat gross to have a configure check for a common MCA
+# component outside of the normal MCA checks, but this check must come
+# after the opal DL MCA checks have done.  Someday this could perhaps
+# be done better by having some kind of "run this check at the end of
+# all other MCA checks" hook...?
+
+OPAL_CHECK_CUDA_AFTER_OPAL_DL
+
 ##################################
 # MPI Extended Interfaces
 ##################################
@@ -1218,8 +1230,6 @@ fi
 # a C++ compiler.
 AS_IF([test "$OMPI_WANT_FORTRAN_BINDINGS" != "1"],[F77=no FC=no])
 
-LT_CONFIG_LTDL_DIR([opal/libltdl], [subproject])
-LTDL_CONVENIENCE
 LT_INIT([dlopen win32-dll])
 
 # What's the suffix of shared libraries?  Inspired by generated
@@ -1256,8 +1266,6 @@ esac
 AC_SUBST(OPAL_DYN_LIB_PREFIX)
 AC_SUBST(OPAL_DYN_LIB_SUFFIX)
 
-OPAL_SETUP_LIBLTDL
-
 # Need the libtool binary before the rpathify stuff
 LT_OUTPUT