v5.0: Change MCA component build style default to static

NEWS

@@ -20,7 +20,7 @@ Copyright (c) 2012      Sandia National Laboratories.  All rights reserved.
 Copyright (c) 2012      University of Houston. All rights reserved.
 Copyright (c) 2013      NVIDIA Corporation.  All rights reserved.
 Copyright (c) 2013-2018 Intel, Inc. All rights reserved.
-Copyright (c) 2018      Amazon.com, Inc. or its affiliates.  All Rights
+Copyright (c) 2018-2021 Amazon.com, Inc. or its affiliates.  All Rights
                         reserved.
 $COPYRIGHT$
 
@@ -80,6 +80,8 @@ Master (not on release branches yet)
   Currently, this means the Open SHMEM layer will only build if
   a MXM or UCX library is found.
 - Remove all vestiges of the C/R support
+- Change the default component build behavior to prefer building
+  components as part of libmpi.so instead of individual DSOs.
 
 4.0.5 -- August, 2020
 ---------------------

README.md

@@ -966,20 +966,116 @@ Additionally, if a search directory is specified in the form
   `--disable-wrapper-runpath`.
 
 * `--enable-dlopen`:
-  Build all of Open MPI's components as standalone Dynamic Shared
-  Objects (DSO's) that are loaded at run-time (this is the default).
-  The opposite of this option, `--disable-dlopen`, causes two things:
+  Enable loading of Open MPI components as standalone Dynamic
+  Shared Objects (DSOs) that are loaded at run-time.  This option is
+  enabled by default.
 
-  1. All of Open MPI's components will be built as part of Open MPI's
-     normal libraries (e.g., `libmpi`).
-  1. Open MPI will not attempt to open any DSO's at run-time.
+  The opposite of this option, --disable-dlopen, causes the following:
 
-  Note that this option does *not* imply that OMPI's libraries will be
-  built as static objects (e.g., `libmpi.a`).  It only specifies the
-  location of OMPI's components: standalone DSOs or folded into the
-  Open MPI libraries.  You can control whether Open MPI's libraries
-  are build as static or dynamic via `--enable|disable-static` and
-  `--enable|disable-shared`.
+  1. Open MPI will not attempt to open any DSOs at run-time.
+  1. configure behaves as if the --enable-mca-static argument was set.
+  1. configure will ignore the --enable-mca-dso argument.
+
+  See the description of --enable-mca-static / --enable-mca-dso for
+  more information.
+
+  Note that this option does *not* change how Open MPI's libraries
+  (libmpi, for example) will be built.  You can change whether Open
+  MPI builds static or dynamic libraries via the
+  --enable|disable-static and --enable|disable-shared arguments.
+
+* `--enable-mca-dso[=LIST]` and `--enable-mca-static[=LIST]`
+  These two options, along with --enable-mca-no-build, govern the
+  behavior of how Open MPI's frameworks and components are built.
+
+  The --enable-mca-dso option specifies which frameworks and/or
+  components are built as Dynamic Shared Objects (DSOs).
+  Specifically, DSOs are built as "plugins" outside of the core Open
+  MPI libraries, and are loaded by Open MPI at run time.
+
+  The --enable-mca-static option specifies which frameworks and/or
+  components are built as part of the core Open MPI libraries (i.e.,
+  they are not built as DSOs, and therefore do not need to be
+  separately discovered and opened at run time).
+
+  Both options can be used one of two ways:
+
+  1. --enable-mca-OPTION (with no value)
+  1. --enable-mca-OPTION=LIST
+
+  --enable-mca-OPTION=no or --disable-mca-OPTION are both legal
+  options, but have no impact on the selection logic described below.
+  Only affirmative options change the selection process.
+
+  LIST is a comma-delimited list of Open MPI frameworks and/or
+  framework+component tuples.  Examples:
+
+  * "btl" specifies the entire BTL framework
+  * "btl-tcp" specifies just the TCP component in the BTL framework
+  * "mtl,btl-tcp" specifies the entire MTL framework and the TCP
+     component in the BTL framework
+
+  Open MPI's configure script uses the values of these two options
+  when evaluating each component to determine how it should be built
+  by evaluating these conditions in order:
+
+  1. If an individual component's build behavior has been specified
+     via these two options, configure uses that behavior.
+  1. Otherwise, if the component is in a framework whose build
+     behavior has been specified via these two options, configure uses
+     that behavior.
+  1. Otherwise, configure uses the global default build behavior.
+
+  At each level of the selection process, if the component is
+  specified to be built as both a static and dso component, the static
+  option will win.
+
+  Note that as of Open MPI v5.0.0, configure's global default is to
+  build all components as static (i.e., part of the Open MPI core
+  libraries, not as DSO's).  Prior to Open MPI v5.0.0, the global
+  default behavior was to build most components as DSOs.
+
+  Also note that if the --disable-dlopen option is specified, then
+  Open MPI will not be able to search for DSOs at run time, and the
+  value of the --enable-mca-dso option will be silently ignored.
+
+  Some examples:
+
+  1. Default to building all components as static (i.e., as part of
+     the Open MPI core libraries -- no DSOs):
+
+     $ ./configure
+
+  1. Build all components as static, except the TCP BTL, which will be
+     built as a DSO:
+
+     $ ./configure --enable-mca-dso=btl-tcp
+
+  1. Build all components as static, except all BTL components, which
+     will be built as DSOs:
+
+     $ ./configure --enable-mca-dso=btl
+
+  1. Build all components as static, except all MTL components and the
+     TCP BTL component, which will be built as DSOs:
+
+     $ ./configure --enable-mca-dso=mtl,btl-tcp
+
+  1. Build all BTLs as static, except the TCP BTL, as the
+     <framework-component> option is more specific than the
+     <framework> option:
+
+     $ ./configure --enable-mca-dso=btl --enable-mca-static=btl-tcp
+
+  1. Build the TCP BTL as static, because the static option at the
+     same level always wins:
+
+     $ ./configure --enable-mca-dso=btl-tcp --enable-mca-static=btl-tcp
+
+* `--enable-mca-no-build=LIST`:
+  Comma-separated list of `<framework>-<component>` pairs that will not be
+  built. For example, `--enable-mca-no-build=btl-portals,oob-ud` will
+  disable building the portals BTL and the ud OOB component.
 
 * `--disable-show-load-errors-by-default`:
   Set the default value of the `mca_base_component_show_load_errors`
@@ -1022,11 +1118,6 @@ Additionally, if a search directory is specified in the form
   these libraries for their own purposes. This option is *not*
   intended for typical users of Open MPI.
 
-* `--enable-mca-no-build=LIST`:
-  Comma-separated list of `<type>-<component>` pairs that will not be
-  built. For example, `--enable-mca-no-build=btl-portals,oob-ud` will
-  disable building the portals BTL and the ud OOB component.
-
 
 ### Networking support / options
 

config/opal_configure_options.m4

@@ -275,8 +275,6 @@ AC_ARG_ENABLE([dlopen],
                      Disabling dlopen implies --disable-mca-dso.
                      (default: enabled)])])
 if test "$enable_dlopen" = "no" ; then
-    enable_mca_dso=no
-    enable_mca_static=yes
     OPAL_ENABLE_DLOPEN_SUPPORT=0
     AC_MSG_RESULT([no])
 else

config/opal_mca.m4

@@ -12,7 +12,7 @@ dnl Copyright (c) 2004-2005 The Regents of the University of California.
 dnl                         All rights reserved.
 dnl Copyright (c) 2010-2016 Cisco Systems, Inc.  All rights reserved.
 dnl Copyright (c) 2013-2017 Intel, Inc. All rights reserved.
-dnl Copyright (c) 2018      Amazon.com, Inc. or its affiliates.
+dnl Copyright (c) 2018-2021 Amazon.com, Inc. or its affiliates.
 dnl                         All Rights reserved.
 dnl $COPYRIGHT$
 dnl
@@ -68,16 +68,16 @@ AC_DEFUN([OPAL_MCA],[
                         type-component pairs that will be built as
                         run-time loadable components (as opposed to
                         statically linked in), if supported on this
-                        platform.  The default is to build all components
-                        as DSOs.])])
+                        platform.])])
     AC_ARG_ENABLE([mca-static],
         [AS_HELP_STRING([--enable-mca-static=LIST],
                        [Comma-separated list of types and/or
                         type-component pairs that will be built statically
                         linked into the library.  The default (if DSOs are
                         supported) is to build all components as DSOs.
                         Enabling a component as static disables it
-                        building as a DSO.])])
+                        building as a DSO.  The default is to build all
+                        components staticly.])])
     AC_ARG_ENABLE([mca-direct],
         [AS_HELP_STRING([--enable-mca-direct=LIST],
                        [Comma-separated list of type-component pairs that
@@ -168,14 +168,19 @@ AC_DEFUN([OPAL_MCA],[
     AC_MSG_CHECKING([which components should be run-time loadable])
     if test "$enable_static" != "no"; then
         DSO_all=0
-        msg=none
-    elif test -z "$enable_mca_dso" || test "$enable_mca_dso" = "yes"; then
-        DSO_all=1
-        msg=all
+        msg="none (static libraries built)"
+    elif test "$OPAL_ENABLE_DLOPEN_SUPPORT" = 0; then
+        DSO_all=0
+        msg="none (dlopen disabled)"
+    elif test -z "$enable_mca_dso"; then
+        DSO_all=0
+        msg=default
     elif test "$enable_mca_dso" = "no"; then
         DSO_all=0
         msg=none
-        enable_dlopen=no
+    elif test "$enable_mca_dso" = "yes"; then
+        DSO_all=1
+        msg=all
     else
         DSO_all=0
         ifs_save="$IFS"
@@ -196,12 +201,15 @@ AC_DEFUN([OPAL_MCA],[
     fi
 
     AC_MSG_CHECKING([which components should be static])
-    if test "$enable_mca_static" = "yes"; then
-        STATIC_all=1
-        msg=all
-    elif test -z "$enable_mca_static" || test "$enable_mca_static" = "no"; then
+    if test -z "$enable_mca_static" ; then
+        STATIC_all=0
+        msg=default
+    elif test "$enable_mca_static" = "no"; then
         STATIC_all=0
         msg=none
+    elif test "$enable_mca_static" = "yes"; then
+        STATIC_all=1
+        msg=all
     else
         STATIC_all=0
         ifs_save="$IFS"
@@ -706,20 +714,23 @@ AC_DEFUN([MCA_COMPONENT_COMPILE_MODE],[
         [str="STATIC_COMPONENT=\$STATIC_$2_$3"
          eval $str])
 
-    shared_mode_override=static
-
-    # Setup for either shared or static
-    if test "$STATIC_FRAMEWORK" = "1" || \
-       test "$STATIC_COMPONENT" = "1" || \
-       test "$STATIC_all" = "1" ; then
-        $4="static"
-    elif test "$shared_mode_override" = "dso" || \
-         test "$SHARED_FRAMEWORK" = "1" || \
-         test "$SHARED_COMPONENT" = "1" || \
-         test "$DSO_all" = "1"; then
-        $4="dso"
+    # Look for the most specific specifier between static/dso.  If
+    # there is a tie (either neither or both specified), prefer
+    # static.
+    if test "$STATIC_COMPONENT" = "1"; then
+        $4=static
+    elif test "SHARED_COMPONENT" = "1"; then
+        $4=dso
+    elif test "$STATIC_FRAMEWORK" = "1"; then
+        $4=static
+    elif test "$SHARED_FRAMEWORK" = "1"; then
+        $4=dso
+    elif test "$STATIC_all" = "1"; then
+        $4=static
+    elif test "$DSO_all" = "1"; then
+        $4=dso
     else
-        $4="static"
+        $4=static
     fi
 
     AC_MSG_CHECKING([for MCA component $2:$3 compile mode])