Extract the install prefix from the shared library.

config/opal_config_libevent.m4

@@ -205,6 +205,7 @@ AC_DEFUN([_OPAL_CONFIG_LIBEVENT_INTERNAL], [
     OPAL_VAR_SCOPE_PUSH(subconfig_happy subconfig_prefix internal_libevent_location)
 
     AS_IF([test ! -z $prefix], [subconfig_prefix="--prefix=$prefix"])
+    AS_IF([test ! -z $libdir], [subconfig_prefix="--libdir=$libdir"])
 
     # Note: To update the version of libevent shipped, update the
     # constant in autogen.pl.

opal/mca/installdirs/base/installdirs_base_components.c

@@ -21,7 +21,11 @@
 #include "opal/mca/installdirs/installdirs.h"
 #include "opal/mca/mca.h"
 
+#include <sys/stat.h>
+#include <errno.h>
+
 opal_install_dirs_t opal_install_dirs = {0};
+static int opal_install_dir_warn_if_non_existent = 0;
 
 #define CONDITIONAL_COPY(target, origin, field)             \
     do {                                                    \
@@ -30,6 +34,23 @@ opal_install_dirs_t opal_install_dirs = {0};
         }                                                   \
     } while (0)
 
+#define CHECK_AND_COMPLAIN(field) \
+    do { \
+        if(!directory_exists(opal_install_dirs.field)) { \
+            fprintf(stderr, #field ":         %s\n", opal_install_dirs.field); \
+        } \
+    } while (0)
+
+static int directory_exists(const char *path)
+{
+    struct stat info;
+
+    if (0 != stat(path, &info)) {
+        return 0;
+    }
+    return S_ISDIR(info.st_mode);
+}
+
 static int opal_installdirs_base_open(mca_base_open_flag_t flags)
 {
     mca_base_component_list_item_t *component_item;
@@ -87,26 +108,30 @@ static int opal_installdirs_base_open(mca_base_open_flag_t flags)
     opal_install_dirs.opalincludedir = opal_install_dirs_expand_setup(
         opal_install_dirs.opalincludedir);
 
-#if 0
-    fprintf(stderr, "prefix:         %s\n", opal_install_dirs.prefix);
-    fprintf(stderr, "exec_prefix:    %s\n", opal_install_dirs.exec_prefix);
-    fprintf(stderr, "bindir:         %s\n", opal_install_dirs.bindir);
-    fprintf(stderr, "sbindir:        %s\n", opal_install_dirs.sbindir);
-    fprintf(stderr, "libexecdir:     %s\n", opal_install_dirs.libexecdir);
-    fprintf(stderr, "datarootdir:    %s\n", opal_install_dirs.datarootdir);
-    fprintf(stderr, "datadir:        %s\n", opal_install_dirs.datadir);
-    fprintf(stderr, "sysconfdir:     %s\n", opal_install_dirs.sysconfdir);
-    fprintf(stderr, "sharedstatedir: %s\n", opal_install_dirs.sharedstatedir);
-    fprintf(stderr, "localstatedir:  %s\n", opal_install_dirs.localstatedir);
-    fprintf(stderr, "libdir:         %s\n", opal_install_dirs.libdir);
-    fprintf(stderr, "includedir:     %s\n", opal_install_dirs.includedir);
-    fprintf(stderr, "infodir:        %s\n", opal_install_dirs.infodir);
-    fprintf(stderr, "mandir:         %s\n", opal_install_dirs.mandir);
-    fprintf(stderr, "pkgdatadir:     %s\n", opal_install_dirs.pkgdatadir);
-    fprintf(stderr, "pkglibdir:      %s\n", opal_install_dirs.pkglibdir);
-    fprintf(stderr, "pkgincludedir:  %s\n", opal_install_dirs.pkgincludedir);
-#endif
+    (void)mca_base_var_register("opal", "opal", "installdir", "warn",
+                                "Print a warning is any of the OMPI necessary paths cannot be found",
+                                MCA_BASE_VAR_TYPE_INT, NULL, 0, 0, OPAL_INFO_LVL_9,
+                                MCA_BASE_VAR_SCOPE_READONLY, &opal_install_dir_warn_if_non_existent);
 
+    if(opal_install_dir_warn_if_non_existent) {
+        CHECK_AND_COMPLAIN(prefix);
+        CHECK_AND_COMPLAIN(exec_prefix);
+        CHECK_AND_COMPLAIN(bindir);
+        //CHECK_AND_COMPLAIN(sbindir);
+        //CHECK_AND_COMPLAIN(libexecdir);
+        CHECK_AND_COMPLAIN(datarootdir);
+        CHECK_AND_COMPLAIN(datadir);
+        CHECK_AND_COMPLAIN(sysconfdir);
+        //CHECK_AND_COMPLAIN(sharedstatedir);
+        //CHECK_AND_COMPLAIN(localstatedir);
+        CHECK_AND_COMPLAIN(libdir);
+        CHECK_AND_COMPLAIN(includedir);
+        //CHECK_AND_COMPLAIN(infodir);
+        CHECK_AND_COMPLAIN(mandir);
+        CHECK_AND_COMPLAIN(opaldatadir);
+        CHECK_AND_COMPLAIN(opallibdir);
+        CHECK_AND_COMPLAIN(opalincludedir);
+    }
     /* NTH: Is it ok not to close the components? If not we can add a flag
        to mca_base_framework_components_close to indicate not to deregister
        variable groups */

opal/mca/installdirs/config/Makefile.am

@@ -18,4 +18,4 @@ libmca_installdirs_config_la_SOURCES = \
 
 # This file is generated; we do not want to include it in the tarball
 nodist_libmca_installdirs_config_la_SOURCES = \
-        install_dirs.h
+        ../install_dirs.h

opal/mca/installdirs/config/configure.m4

@@ -24,6 +24,6 @@ AC_DEFUN([MCA_opal_installdirs_config_COMPILE_MODE], [
 # ------------------------------------------------
 AC_DEFUN([MCA_opal_installdirs_config_CONFIG],[
     AC_CONFIG_FILES([opal/mca/installdirs/config/Makefile
-                     opal/mca/installdirs/config/install_dirs.h])
+                     opal/mca/installdirs/install_dirs.h])
 ])
 

opal/mca/installdirs/config/opal_installdirs_config.c

@@ -10,7 +10,7 @@
 
 #include "opal_config.h"
 
-#include "opal/mca/installdirs/config/install_dirs.h"
+#include "opal/mca/installdirs/install_dirs.h"
 #include "opal/mca/installdirs/installdirs.h"
 
 const opal_installdirs_base_component_t mca_installdirs_config_component = {

opal/mca/installdirs/runtime/Makefile.am

@@ -0,0 +1,14 @@
+#
+# Copyright (c) 2025      NVIDIA Corporation.  All rights reserved.
+# $COPYRIGHT$
+#
+# Additional copyrights may follow
+#
+# $HEADER$
+#
+
+noinst_LTLIBRARIES = libmca_installdirs_runtime.la
+
+libmca_installdirs_runtime_la_SOURCES = \
+	opal_installdirs_runtime.c
+libmca_installdirs_runtime_la_CPPFLAGS = -DOPAL_LIB_NAME=\"@OPAL_LIB_NAME@\"

opal/mca/installdirs/runtime/configure.m4

@@ -0,0 +1,45 @@
+# -*- shell-script -*-
+#
+# Copyright (c) 2025      NVIDIA Corporation.  All rights reserved.
+# $COPYRIGHT$
+#
+# Additional copyrights may follow
+#
+# $HEADER$
+#
+
+AC_DEFUN([MCA_opal_installdirs_runtime_PRIORITY], [5])
+
+AC_DEFUN([MCA_opal_installdirs_runtime_COMPILE_MODE], [
+    AC_MSG_CHECKING([for MCA component $2:$3 compile mode])
+    $4="static"
+    AC_MSG_RESULT([$$4])
+])
+
+# MCA_installdirs_config_CONFIG(action-if-can-compile,
+#                        [action-if-cant-compile])
+# ------------------------------------------------
+AC_DEFUN([MCA_opal_installdirs_runtime_CONFIG], [
+    # Check if we are building a shared library or not. Disable if static
+    AC_MSG_CHECKING([if shared libraries are enabled])
+    AS_IF([test "$enable_shared" != "yes"],
+          [installdirs_runtime_happy="no"],
+          [installdirs_runtime_happy="yes"])
+    AC_MSG_RESULT([$installdirs_runtime_happy])
+
+    # Check if dladdr is available
+    AS_IF([test "$installdirs_runtime_happy" = "yes"],
+          [AC_CHECK_HEADERS([dlfcn.h],
+                            [],
+                            [installdirs_runtime_happy="no"])])
+    AS_IF([test "$installdirs_runtime_happy" = "yes"],
+          [AC_CHECK_LIB([dl], [dladdr],
+                        [],
+                        [installdirs_runtime_happy="no"])
+          ])
+    #
+    AS_IF([test "$installdirs_runtime_happy" = "yes"],
+          [AC_CONFIG_FILES([opal/mca/installdirs/runtime/Makefile])
+           $1], [$2])
+])
+

opal/mca/installdirs/runtime/opal_installdirs_runtime.c

@@ -0,0 +1,111 @@
+/*
+ * Copyright (c) 2006-2007 Los Alamos National Security, LLC.  All rights
+ *                         reserved.
+ * Copyright (c) 2007      Cisco Systems, Inc.  All rights reserved.
+ * $COPYRIGHT$
+ *
+ * Additional copyrights may follow
+ *
+ * $HEADER$
+ */
+
+#include "opal_config.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "opal/constants.h"
+#include "opal/mca/installdirs/installdirs.h"
+#include "opal/runtime/opal.h"
+
+static int installdirs_runtime_open(void);
+
+opal_installdirs_base_component_t mca_installdirs_runtime_component = {
+    /* First, the mca_component_t struct containing meta information
+       about the component itself */
+    {OPAL_INSTALLDIRS_BASE_VERSION_2_0_0,
+
+     /* Component name and version */
+     "runtime", OPAL_MAJOR_VERSION, OPAL_MINOR_VERSION, OPAL_RELEASE_VERSION,
+
+     /* Component open and close functions */
+     installdirs_runtime_open, NULL},
+    {/* This component is checkpointable */
+     MCA_BASE_METADATA_PARAM_CHECKPOINT},
+
+    /* Next the opal_install_dirs_t install_dirs_data information */
+    {
+        NULL,
+    },
+};
+
+#include <dlfcn.h>
+#include "opal/util/basename.h"
+#include "opal/mca/installdirs/install_dirs.h"
+
+/**
+ * We are trying to solve a particular use case here, when the entire install tree
+ * of Open MPI (and its dependencies) has been moved into another location. Nothing
+ * fancy, the entire install tree has maintained his shape but changed the prefix.
+ */
+static int installdirs_runtime_open(void)
+{
+    Dl_info info;
+    void* opal_fct;
+    char* libname = NULL;
+    const char* base_prefix_path = OPAL_LIBDIR;
+
+    /* Casting from void* to fct pointer according to POSIX.1-2001 and POSIX.1-2008 */
+    *(void **)&opal_fct = dlsym(RTLD_DEFAULT, "opal_init_util");
+
+    if( 0 == dladdr(opal_fct, &info) ) {
+        goto bail_out_with_no_data;
+    }
+
+    /* If this build was both static and shared then this compoenent will be build and will exists
+     * even in the static library. We need to prevent setting a prefix for the OMPI library that
+     * is actually the application path. Check, if the name points to a library.
+     */
+    libname = opal_basename(info.dli_fname);
+    if( strncmp(libname, "lib", 3)) {  /* not a shared library */
+        base_prefix_path = OPAL_BINDIR;
+    } else {
+#if defined(OPAL_LIB_NAME)
+        /* Extra check using the installed name of the OPAL library */
+        if( strncmp(libname+3, OPAL_LIB_NAME, strlen(OPAL_LIB_NAME)) ) {  /* not a shared library */
+            goto bail_out_with_no_data;
+        }
+#endif  /* defined(OPAL_LIB_NAME) */
+    }
+    /* Remove the shared library name and it's first dirname to obtain a prefix. This
+     * is true in most cases, especially when the install directory was just moved
+     * moved around, but it is not necessarily always true.
+     */
+    char *prefix = NULL, *dname = opal_dirname(info.dli_fname);
+    int dname_idx = strlen(dname), dname_token = dname_idx;
+    for( int i = strlen(base_prefix_path); (i > 0) && (dname_idx > 0); i-- ) {
+        if( dname[dname_idx] != base_prefix_path[i] ) {
+            dname[dname_token] = '\0';
+            prefix = dname;
+            dname = NULL;  /* the string is now attached to the component, prevent it from being freed */
+            break;
+        }
+        if( dname[dname_idx] == OPAL_PATH_SEP[0] )
+            dname_token = dname_idx;
+        dname_idx--;
+    }
+
+    mca_installdirs_runtime_component.install_dirs_data.prefix = prefix;
+
+    /* If we goto here, there is some error. Unfortunately, we can't return an error from
+     * this function, the MCA infrastructure is not yet completely setup, and a call to
+     * mca_base_component_close will break.
+     * So, return success but provide no meaningfull data in the component.
+     */
+  bail_out_with_no_data:
+
+    free(libname);
+    free(dname);
+
+    return OPAL_SUCCESS;
+}

opal/mca/installdirs/runtime/owner.txt

@@ -0,0 +1,7 @@
+#
+# owner/status file
+# owner: institution that is responsible for this package
+# status: e.g. active, maintenance, unmaintained
+#
+owner: NVIDIA
+status: active