VFD SWMR: Normalization with develop (#1506)

* Brought over plugin and test script changes

* Removes remaining register keywords (#1481)

* Fixed warnings in the aux process code

* Minor fixes from develop

* Minor changes from develop, fixed format warnings

* Formatted source

* Added HD prefix to timespec_get

* Cleanup in new files

* Removes the MANIFEST file and unused release files (#1497)

* Removes the MANIFEST file and unused release files

* Updated tar command

* checkposix corrections

* More checkposix fixes

* Ripped out unused instrumentation functionality

* Brought over cache tagging changes from develop

* Changes to tagged metadata expulsion iteration

* Fixed typo

* Brought over H5O__free() changes from develop

* Brings (unused) parallel page buffer test in line with develop

* Moved the functionality in supervise.subr to test_vfd_swmr.sh

* Tools VFD parameter updates

* Committing clang-format changes

* H5F VFD SWMR refactoring

* Committing clang-format changes

* Misc changes

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

5 files changed, 169 insertions, 130 deletions

diff --git a/tools/lib/h5diff.c b/tools/lib/h5diff.c
index 2275c72..debd54a 100644
--- a/tools/lib/h5diff.c
+++ b/tools/lib/h5diff.c
@@ -648,14 +648,16 @@ h5diff(const char *fname1, const char *fname2, const char *objname1, const char
      *-------------------------------------------------------------------------
      */
     /* open file 1 */
-    if (opts->custom_vol[0]) {
-        if ((fapl1_id = h5tools_get_fapl(H5P_DEFAULT, &(opts->vol_info[0]), NULL)) < 0) {
+    if (opts->custom_vol[0] || opts->custom_vfd[0]) {
+        if ((fapl1_id = h5tools_get_fapl(H5P_DEFAULT, opts->custom_vol[0] ? &(opts->vol_info[0]) : NULL,
+                                         opts->custom_vfd[0] ? &(opts->vfd_info[0]) : NULL)) < 0) {
             parallel_print("h5diff: unable to create fapl for input file\n");
             H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "unable to create input fapl\n");
         }
     }
 
-    if ((file1_id = h5tools_fopen(fname1, H5F_ACC_RDONLY, fapl1_id, FALSE, NULL, (size_t)0)) < 0) {
+    if ((file1_id = h5tools_fopen(fname1, H5F_ACC_RDONLY, fapl1_id, (fapl1_id != H5P_DEFAULT), NULL,
+                                  (size_t)0)) < 0) {
         parallel_print("h5diff: <%s>: unable to open file\n", fname1);
         H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "<%s>: unable to open file\n", fname1);
     }
@@ -663,14 +665,16 @@ h5diff(const char *fname1, const char *fname2, const char *objname1, const char
 
     /* open file 2 */
 
-    if (opts->custom_vol[1]) {
-        if ((fapl2_id = h5tools_get_fapl(H5P_DEFAULT, &(opts->vol_info[1]), NULL)) < 0) {
+    if (opts->custom_vol[1] || opts->custom_vfd[1]) {
+        if ((fapl2_id = h5tools_get_fapl(H5P_DEFAULT, opts->custom_vol[1] ? &(opts->vol_info[1]) : NULL,
+                                         opts->custom_vfd[1] ? &(opts->vfd_info[1]) : NULL)) < 0) {
             parallel_print("h5diff: unable to create fapl for output file\n");
             H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "unable to create output fapl\n");
         }
     }
 
-    if ((file2_id = h5tools_fopen(fname2, H5F_ACC_RDONLY, fapl2_id, FALSE, NULL, (size_t)0)) < 0) {
+    if ((file2_id = h5tools_fopen(fname2, H5F_ACC_RDONLY, fapl2_id, (fapl2_id != H5P_DEFAULT), NULL,
+                                  (size_t)0)) < 0) {
         parallel_print("h5diff: <%s>: unable to open file\n", fname2);
         H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "<%s>: unable to open file\n", fname2);
     }
diff --git a/tools/lib/h5diff.h b/tools/lib/h5diff.h
index 87eff98..4afb3f6 100644
--- a/tools/lib/h5diff.h
+++ b/tools/lib/h5diff.h
@@ -89,7 +89,9 @@ typedef struct {
     char *                    obj_name[2];             /* name for object */
     struct subset_t *         sset[2];                 /* subsetting parameters */
     h5tools_vol_info_t        vol_info[2];             /* VOL information for input file, output file */
+    h5tools_vfd_info_t        vfd_info[2];             /* VFD information for input file, output file */
     hbool_t                   custom_vol[2];           /* Using a custom input, output VOL? */
+    hbool_t                   custom_vfd[2];           /* Using a custom input, output VFD? */
 } diff_opt_t;
 
 /*-------------------------------------------------------------------------
diff --git a/tools/lib/h5tools.c b/tools/lib/h5tools.c
index 45fc78c..a88b164 100644
--- a/tools/lib/h5tools.c
+++ b/tools/lib/h5tools.c
@@ -460,27 +460,29 @@ h5tools_set_error_file(const char *fname, int is_bin)
     return retvalue;
 }
 
+/*-------------------------------------------------------------------------
+ * Function: h5tools_set_up_vfd_swmr
+ *
+ * Purpose:  Set up VFD SWMR on the fapl
+ *
+ * Return:   positive - succeeded
+ *           negative - failed
+ *-------------------------------------------------------------------------
+ */
 static hid_t
-swmr_fapl_augment(hid_t fapl, const char *fname)
+h5tools_set_up_vfd_swmr(hid_t fapl, const char *fname)
 {
-    H5F_vfd_swmr_config_t *config = NULL; /* Configuration for VFD SWMR */
-    char *                 dname  = NULL;
+    H5F_vfd_swmr_config_t *config    = NULL; /* Configuration for VFD SWMR */
+    char *                 dname     = NULL;
+    hid_t                  ret_value = H5I_INVALID_HID;
 
-    /*
-     * Set up to open the file with VFD SWMR configured.
-     */
     /* Enable page buffering */
-    if (H5Pset_page_buffer_size(fapl, 4096, 100, 0) < 0) {
-        HDfprintf(rawerrorstream, "H5Pset_page_buffer_size failed\n");
-        return H5I_INVALID_HID;
-    }
+    if (H5Pset_page_buffer_size(fapl, 4096, 100, 0) < 0)
+        H5TOOLS_GOTO_ERROR(H5I_INVALID_HID, "H5Pset_page_buffer_size failed");
 
     /* Allocate memory for the configuration structure */
-    config = (H5F_vfd_swmr_config_t *)HDcalloc(1, sizeof(*config));
-    if (config == NULL) {
-        HDfprintf(rawerrorstream, "VFD SWMR config allocation failed\n");
-        return H5I_INVALID_HID;
-    }
+    if (NULL == (config = HDcalloc(1, sizeof(*config))))
+        H5TOOLS_GOTO_ERROR(H5I_INVALID_HID, "VFD SWMR config allocation failed");
 
     config->version           = H5F__CURR_VFD_SWMR_CONFIG_VERSION;
     config->tick_len          = 4;
@@ -488,26 +490,25 @@ swmr_fapl_augment(hid_t fapl, const char *fname)
     config->writer            = FALSE;
     config->md_pages_reserved = 128;
 
-    if (H5_dirname(fname, &dname) < 0) {
-        HDfprintf(rawerrorstream, "H5_dirname() failed\n");
-        return H5I_INVALID_HID;
-    }
+    if (H5_dirname(fname, &dname) < 0)
+        H5TOOLS_GOTO_ERROR(H5I_INVALID_HID, "H5_dirname() failed");
+
     HDsnprintf(config->md_file_path, sizeof(config->md_file_path), "%s/my_md_file", dname);
-    HDfree(dname);
 
     /* Enable VFD SWMR configuration */
-    if (H5Pset_vfd_swmr_config(fapl, config) < 0) {
-        HDfprintf(rawerrorstream, "H5Pset_vrd_swmr_config failed\n");
-        return H5I_INVALID_HID;
-    }
-    return fapl;
+    if (H5Pset_vfd_swmr_config(fapl, config) < 0)
+        H5TOOLS_GOTO_ERROR(H5I_INVALID_HID, "H5Pset_vrd_swmr_config failed");
+
+done:
+    HDfree(dname);
+    return ret_value;
 }
 
 /*-------------------------------------------------------------------------
  * Function: h5tools_set_fapl_vfd
  *
- * Purpose:  Given a VFL driver name, sets the appropriate driver on the
- *           specified FAPL.
+ * Purpose:  Given a VFL driver name or ID, sets the appropriate driver on
+ *           the specified FAPL.
  *
  * Return:   positive - succeeded
  *           negative - failed
@@ -518,110 +519,136 @@ h5tools_set_fapl_vfd(hid_t fapl_id, h5tools_vfd_info_t *vfd_info)
 {
     herr_t ret_value = SUCCEED;
 
-    /* Determine which driver the user wants to open the file with */
-    if (!HDstrcmp(vfd_info->name, drivernames[SWMR_VFD_IDX])) {
-        /* SWMR driver */
-        if (swmr_fapl_augment(fapl_id, vfd_info->fname) < 0)
-            H5TOOLS_GOTO_ERROR(FAIL, "swmr_fapl_augment failed");
-    }
-    else if (!HDstrcmp(vfd_info->name, drivernames[SEC2_VFD_IDX])) {
-        /* SEC2 Driver */
-        if (H5Pset_fapl_sec2(fapl_id) < 0)
-            H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_sec2 failed");
-    }
-    else if (!HDstrcmp(vfd_info->name, drivernames[DIRECT_VFD_IDX])) {
+    switch (vfd_info->type) {
+        case VFD_BY_NAME:
+            /* Determine which driver the user wants to open the file with */
+            if (!HDstrcmp(vfd_info->u.name, drivernames[SEC2_VFD_IDX])) {
+                /* SEC2 Driver */
+                if (H5Pset_fapl_sec2(fapl_id) < 0)
+                    H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_sec2 failed");
+            }
+            else if (!HDstrcmp(vfd_info->u.name, drivernames[DIRECT_VFD_IDX])) {
 #ifdef H5_HAVE_DIRECT
-        /* Direct Driver */
-        if (H5Pset_fapl_direct(fapl_id, 1024, 4096, 8 * 4096) < 0)
-            H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_direct failed");
+                /* Direct Driver */
+                if (H5Pset_fapl_direct(fapl_id, 1024, 4096, 8 * 4096) < 0)
+                    H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_direct failed");
 #else
-        H5TOOLS_GOTO_ERROR(FAIL, "Direct VFD is not enabled");
+                H5TOOLS_GOTO_ERROR(FAIL, "Direct VFD is not enabled");
 #endif
-    }
-    else if (!HDstrcmp(vfd_info->name, drivernames[LOG_VFD_IDX])) {
-        unsigned long long log_flags = H5FD_LOG_LOC_IO | H5FD_LOG_ALLOC;
+            }
+            else if (!HDstrcmp(vfd_info->u.name, drivernames[LOG_VFD_IDX])) {
+                unsigned long long log_flags = H5FD_LOG_LOC_IO | H5FD_LOG_ALLOC;
 
-        /* Log Driver */
-        if (H5Pset_fapl_log(fapl_id, NULL, log_flags, (size_t)0) < 0)
-            H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_log failed");
-    }
-    else if (!HDstrcmp(vfd_info->name, drivernames[WINDOWS_VFD_IDX])) {
+                /* Log Driver */
+                if (H5Pset_fapl_log(fapl_id, NULL, log_flags, (size_t)0) < 0)
+                    H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_log failed");
+            }
+            else if (!HDstrcmp(vfd_info->u.name, drivernames[WINDOWS_VFD_IDX])) {
 #ifdef H5_HAVE_WINDOWS
-        /* There is no Windows VFD - use SEC2 */
-        if (H5Pset_fapl_sec2(fapl_id) < 0)
-            H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_sec2 failed");
+                /* There is no Windows VFD - use SEC2 */
+                if (H5Pset_fapl_sec2(fapl_id) < 0)
+                    H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_sec2 failed");
 #else
-        H5TOOLS_GOTO_ERROR(FAIL, "Windows VFD is not enabled");
+                H5TOOLS_GOTO_ERROR(FAIL, "Windows VFD is not enabled");
 #endif
-    }
-    else if (!HDstrcmp(vfd_info->name, drivernames[STDIO_VFD_IDX])) {
-        /* Stdio Driver */
-        if (H5Pset_fapl_stdio(fapl_id) < 0)
-            H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_stdio failed");
-    }
-    else if (!HDstrcmp(vfd_info->name, drivernames[CORE_VFD_IDX])) {
-        /* Core Driver */
-        if (H5Pset_fapl_core(fapl_id, (size_t)H5_MB, TRUE) < 0)
-            H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_core failed");
-    }
-    else if (!HDstrcmp(vfd_info->name, drivernames[FAMILY_VFD_IDX])) {
-        /* FAMILY Driver */
-        /* Set member size to be 0 to indicate the current first member size
-         * is the member size.
-         */
-        if (H5Pset_fapl_family(fapl_id, (hsize_t)0, H5P_DEFAULT) < 0)
-            H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_family failed");
-    }
-    else if (!HDstrcmp(vfd_info->name, drivernames[SPLIT_VFD_IDX])) {
-        /* SPLIT Driver */
-        if (H5Pset_fapl_split(fapl_id, "-m.h5", H5P_DEFAULT, "-r.h5", H5P_DEFAULT) < 0)
-            H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_split failed");
-    }
-    else if (!HDstrcmp(vfd_info->name, drivernames[MULTI_VFD_IDX])) {
-        /* MULTI Driver */
-        if (H5Pset_fapl_multi(fapl_id, NULL, NULL, NULL, NULL, TRUE) < 0)
-            H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_multi failed");
-    }
-    else if (!HDstrcmp(vfd_info->name, drivernames[MPIO_VFD_IDX])) {
+            }
+            else if (!HDstrcmp(vfd_info->u.name, drivernames[STDIO_VFD_IDX])) {
+                /* Stdio Driver */
+                if (H5Pset_fapl_stdio(fapl_id) < 0)
+                    H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_stdio failed");
+            }
+            else if (!HDstrcmp(vfd_info->u.name, drivernames[CORE_VFD_IDX])) {
+                /* Core Driver */
+                if (H5Pset_fapl_core(fapl_id, (size_t)H5_MB, TRUE) < 0)
+                    H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_core failed");
+            }
+            else if (!HDstrcmp(vfd_info->u.name, drivernames[FAMILY_VFD_IDX])) {
+                /* FAMILY Driver */
+                /* Set member size to be 0 to indicate the current first member size
+                 * is the member size.
+                 */
+                if (H5Pset_fapl_family(fapl_id, (hsize_t)0, H5P_DEFAULT) < 0)
+                    H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_family failed");
+            }
+            else if (!HDstrcmp(vfd_info->u.name, drivernames[SPLIT_VFD_IDX])) {
+                /* SPLIT Driver */
+                if (H5Pset_fapl_split(fapl_id, "-m.h5", H5P_DEFAULT, "-r.h5", H5P_DEFAULT) < 0)
+                    H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_split failed");
+            }
+            else if (!HDstrcmp(vfd_info->u.name, drivernames[MULTI_VFD_IDX])) {
+                /* MULTI Driver */
+                if (H5Pset_fapl_multi(fapl_id, NULL, NULL, NULL, NULL, TRUE) < 0)
+                    H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_multi failed");
+            }
+            else if (!HDstrcmp(vfd_info->u.name, drivernames[MPIO_VFD_IDX])) {
 #ifdef H5_HAVE_PARALLEL
-        int mpi_initialized, mpi_finalized;
+                int mpi_initialized, mpi_finalized;
 
-        /* MPI-I/O Driver */
+                /* MPI-I/O Driver */
 
-        /* check if MPI is available. */
-        MPI_Initialized(&mpi_initialized);
-        MPI_Finalized(&mpi_finalized);
+                /* check if MPI is available. */
+                MPI_Initialized(&mpi_initialized);
+                MPI_Finalized(&mpi_finalized);
 
-        if (mpi_initialized && !mpi_finalized) {
-            if (H5Pset_fapl_mpio(fapl_id, MPI_COMM_WORLD, MPI_INFO_NULL) < 0)
-                H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_mpio failed");
-        }
+                if (mpi_initialized && !mpi_finalized) {
+                    if (H5Pset_fapl_mpio(fapl_id, MPI_COMM_WORLD, MPI_INFO_NULL) < 0)
+                        H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_mpio failed");
+                }
 #else
-        H5TOOLS_GOTO_ERROR(FAIL, "MPI-I/O VFD is not enabled");
+                H5TOOLS_GOTO_ERROR(FAIL, "MPI-I/O VFD is not enabled");
 #endif /* H5_HAVE_PARALLEL */
-    }
-    else if (!HDstrcmp(vfd_info->name, drivernames[ROS3_VFD_IDX])) {
+            }
+            else if (!HDstrcmp(vfd_info->u.name, drivernames[ROS3_VFD_IDX])) {
 #ifdef H5_HAVE_ROS3_VFD
-        if (!vfd_info->info)
-            H5TOOLS_GOTO_ERROR(FAIL, "Read-only S3 VFD info is invalid");
-        if (H5Pset_fapl_ros3(fapl_id, (H5FD_ros3_fapl_t *)vfd_info->info) < 0)
-            H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_ros3() failed");
+                if (!vfd_info->info)
+                    H5TOOLS_GOTO_ERROR(FAIL, "Read-only S3 VFD info is invalid");
+                if (H5Pset_fapl_ros3(fapl_id, (H5FD_ros3_fapl_t *)vfd_info->info) < 0)
+                    H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_ros3() failed");
 #else
-        H5TOOLS_GOTO_ERROR(FAIL, "Read-only S3 VFD is not enabled");
+                H5TOOLS_GOTO_ERROR(FAIL, "Read-only S3 VFD is not enabled");
 #endif
-    }
-    else if (!HDstrcmp(vfd_info->name, drivernames[HDFS_VFD_IDX])) {
+            }
+            else if (!HDstrcmp(vfd_info->u.name, drivernames[HDFS_VFD_IDX])) {
 #ifdef H5_HAVE_LIBHDFS
-        if (!vfd_info->info)
-            H5TOOLS_GOTO_ERROR(FAIL, "HDFS VFD info is invalid");
-        if (H5Pset_fapl_hdfs(fapl_id, (H5FD_hdfs_fapl_t *)vfd_info->info) < 0)
-            H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_hdfs() failed");
+                if (!vfd_info->info)
+                    H5TOOLS_GOTO_ERROR(FAIL, "HDFS VFD info is invalid");
+                if (H5Pset_fapl_hdfs(fapl_id, (H5FD_hdfs_fapl_t *)vfd_info->info) < 0)
+                    H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_hdfs() failed");
 #else
-        H5TOOLS_GOTO_ERROR(FAIL, "The HDFS VFD is not enabled");
+                H5TOOLS_GOTO_ERROR(FAIL, "The HDFS VFD is not enabled");
 #endif
+            }
+            else if (!HDstrcmp(vfd_info->u.name, drivernames[SWMR_VFD_IDX])) {
+                /* VFD SWMR driver */
+                if (h5tools_set_up_vfd_swmr(fapl_id, vfd_info->fname) < 0)
+                    H5TOOLS_GOTO_ERROR(FAIL, "swmr_fapl_augment failed");
+            }
+            else {
+                /*
+                 * Try to load VFD plugin.
+                 *
+                 * Currently, driver configuration strings are unsupported.
+                 */
+                if (H5Pset_driver_by_name(fapl_id, vfd_info->u.name, (const char *)vfd_info->info) < 0)
+                    H5TOOLS_GOTO_ERROR(FAIL, "can't load VFD plugin by driver name '%s'", vfd_info->u.name);
+            }
+
+            break;
+
+        case VFD_BY_VALUE:
+            /*
+             * Try to load VFD plugin.
+             *
+             * Currently, driver configuration strings are unsupported.
+             */
+            if (H5Pset_driver_by_value(fapl_id, vfd_info->u.value, (const char *)vfd_info->info) < 0)
+                H5TOOLS_GOTO_ERROR(FAIL, "can't load VFD plugin by driver value '%ld'",
+                                   (long int)vfd_info->u.value);
+            break;
+
+        default:
+            H5TOOLS_GOTO_ERROR(FAIL, "invalid VFD retrieval type");
     }
-    else
-        H5TOOLS_GOTO_ERROR(FAIL, "invalid VFD name");
 
 done:
     if (ret_value < 0) {
@@ -971,7 +998,7 @@ h5tools_fopen(const char *fname, unsigned flags, hid_t fapl_id, hbool_t use_spec
      * as TRUE, we should return failure now since the file couldn't be opened with
      * the VFL driver/VOL connector that was set on the FAPL by the caller.
      */
-    if (fid < 0 && use_specific_driver)
+    if (use_specific_driver)
         H5TOOLS_GOTO_ERROR(H5I_INVALID_HID, "failed to open file using specified FAPL");
 
     /*
@@ -1012,9 +1039,10 @@ h5tools_fopen(const char *fname, unsigned flags, hid_t fapl_id, hbool_t use_spec
                 if (drivernum == SWMR_VFD_IDX)
                     continue;
 
-                vfd_info.info  = NULL;
-                vfd_info.fname = fname;
-                vfd_info.name  = drivernames[drivernum];
+                vfd_info.type   = VFD_BY_NAME;
+                vfd_info.info   = NULL;
+                vfd_info.fname  = fname;
+                vfd_info.u.name = drivernames[drivernum];
 
                 /* Get a fapl reflecting the selected VOL connector and VFD */
                 if ((tmp_fapl_id = h5tools_get_fapl(fapl_id, &vol_info, &vfd_info)) < 0)
@@ -1085,7 +1113,7 @@ done:
 H5_ATTR_PURE static size_t
 h5tools_count_ncols(const char *s)
 {
-    register size_t i;
+    size_t i;
 
     for (i = 0; *s; s++)
         if (*s >= ' ')
diff --git a/tools/lib/h5tools.h b/tools/lib/h5tools.h
index 8f64dd3..0ae0daa 100644
--- a/tools/lib/h5tools.h
+++ b/tools/lib/h5tools.h
@@ -550,6 +550,7 @@ typedef struct h5tools_context_t {
  */
 
 typedef enum { VOL_BY_NAME, VOL_BY_VALUE } h5tools_vol_info_type_t;
+typedef enum { VFD_BY_NAME, VFD_BY_VALUE } h5tools_vfd_info_type_t;
 
 typedef struct h5tools_vol_info_t {
     h5tools_vol_info_type_t type;
@@ -565,14 +566,18 @@ typedef struct h5tools_vol_info_t {
 } h5tools_vol_info_t;
 
 typedef struct h5tools_vfd_info_t {
+    h5tools_vfd_info_type_t type;
 
     /* Pointer to information to be passed to the driver for its setup */
     const void *info;
 
-    /* Name of the VFD */
-    const char *name;
+    /* Field specifying either the driver's name or value (ID) */
+    union {
+        const char *       name;
+        H5FD_class_value_t value;
+    } u;
 
-    /* Name of the file to open with the VFD */
+    /* Name of the file to open with the VFD (only needed by VFD SWMR) */
     const char *fname;
 } h5tools_vfd_info_t;
 
diff --git a/tools/lib/h5tools_str.c b/tools/lib/h5tools_str.c
index 1fb2c68..5976044 100644
--- a/tools/lib/h5tools_str.c
+++ b/tools/lib/h5tools_str.c
@@ -1051,7 +1051,7 @@ h5tools_str_sprint(h5tools_str_t *str, const h5tool_format_t *info, hid_t contai
 
                 H5TOOLS_DEBUG("H5T_ENUM");
                 if (H5Tenum_nameof(type, vp, enum_name, sizeof enum_name) >= 0)
-                    h5tools_str_append(str, h5tools_escape(enum_name, sizeof(enum_name)));
+                    h5tools_str_append(str, "%s", h5tools_escape(enum_name, sizeof(enum_name)));
                 else {
                     size_t i;
                     if (1 == nsize)
@@ -1401,10 +1401,10 @@ h5tools_str_sprint_reference(h5tools_str_t *str, H5R_ref_t *ref_vp)
 static char *
 h5tools_escape(char *s /*in,out*/, size_t size)
 {
-    register size_t i;
-    const char *    escape;
-    char            octal[8];
-    size_t          n = HDstrlen(s);
+    size_t      i;
+    const char *escape;
+    char        octal[8];
+    size_t      n = HDstrlen(s);
 
     for (i = 0; i < n; i++) {
         switch (s[i]) {