Fix loading plugin fails with missing directory GH issue #3248 (#3324)

4 files changed, 44 insertions, 19 deletions

diff --git a/src/H5PLint.c b/src/H5PLint.c
index e29bc10..1b58be1 100644
--- a/src/H5PLint.c
+++ b/src/H5PLint.c
@@ -258,11 +258,17 @@ H5PL_load(H5PL_type_t type, const H5PL_key_t *key)
     /* If not found, try iterating through the path table to find an appropriate plugin */
     if (!found)
         if (H5PL__find_plugin_in_path_table(&search_params, &found, &plugin_info) < 0)
-            HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, NULL, "search in path table failed")
+            HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, NULL,
+                        "can't find plugin in the paths either set by HDF5_PLUGIN_PATH, or default location, "
+                        "or set by H5PLxxx functions")
 
     /* Set the return value we found the plugin */
     if (found)
         ret_value = plugin_info;
+    else
+        HGOTO_ERROR(H5E_PLUGIN, H5E_NOTFOUND, NULL,
+                    "can't find plugin. Check either HDF5_PLUGIN_PATH, default location, "
+                    "or path set by H5PLxxx functions")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -273,9 +279,31 @@ done:
  *
  * Purpose:     Opens a plugin.
  *
- *              The success parameter will be set to TRUE and the plugin_info
- *              parameter will be filled in on success. Otherwise, they
- *              will be FALSE and NULL, respectively.
+ *              `path` specifies the path to the plugin library file.
+ *
+ *              `type` specifies the type of plugin being searched for and
+ *              will be used to verify that a loaded plugin matches the
+ *              type requested. H5PL_TYPE_NONE may be passed, in which case
+ *              no plugin type verification is performed. This is most
+ *              useful when iterating over available plugins without regard
+ *              to their types.
+ *
+ *              `key` specifies the information that will be used to find a
+ *              specific plugin. For filter plugins, this is typically an
+ *              integer identifier. For VOL connectors, this
+ *              is typically either an integer identifier or a name string.
+ *              After a plugin has been opened, this information will be
+ *              compared against the relevant information provided by the
+ *              plugin to ensure that the plugin is a match. If
+ *              H5PL_TYPE_NONE is provided for `type`, then `key` should be
+ *              NULL.
+ *
+ *              On successful open of a plugin, the `success` parameter
+ *              will be set to TRUE and the `plugin_type` and `plugin_info`
+ *              parameters will be filled appropriately. On failure, the
+ *              `success` parameter will be set to FALSE, the `plugin_type`
+ *              parameter will be set to H5PL_TYPE_ERROR and the
+ *              `plugin_info` parameter will be set to NULL.
  *
  * Return:      SUCCEED/FAIL
  *
diff --git a/src/H5PLpath.c b/src/H5PLpath.c
index a6734cb..10a668c 100644
--- a/src/H5PLpath.c
+++ b/src/H5PLpath.c
@@ -615,9 +615,9 @@ H5PL__path_table_iterate_process_path(const char *plugin_path, H5PL_iterate_type
     HDassert(plugin_path);
     HDassert(iter_op);
 
-    /* Open the directory */
+    /* Open the directory - skip the path if the directory can't be opened */
     if (!(dirp = HDopendir(plugin_path)))
-        HGOTO_ERROR(H5E_PLUGIN, H5E_OPENERROR, H5_ITER_ERROR, "can't open directory: %s", plugin_path)
+        HGOTO_DONE(H5_ITER_CONT);
 
     /* Iterate through all entries in the directory */
     while (NULL != (dp = HDreaddir(dirp))) {
@@ -710,7 +710,7 @@ H5PL__path_table_iterate_process_path(const char *plugin_path, H5PL_iterate_type
      * skip the path if the directory can't be opened */
     HDsnprintf(service, sizeof(service), "%s\\*.dll", plugin_path);
     if ((hFind = FindFirstFileA(service, &fdFile)) == INVALID_HANDLE_VALUE)
-        HGOTO_ERROR(H5E_PLUGIN, H5E_OPENERROR, H5_ITER_ERROR, "can't open directory")
+        HGOTO_DONE(H5_ITER_CONT);
 
     /* Loop over all the files */
     do {
@@ -799,8 +799,7 @@ H5PL__find_plugin_in_path_table(const H5PL_search_params_t *search_params, hbool
 
         /* Search for the plugin in this path */
         if (H5PL__find_plugin_in_path(search_params, found, H5PL_paths_g[u], plugin_info) < 0)
-            HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, FAIL, "search in path %s encountered an error",
-                        H5PL_paths_g[u])
+            HERROR(H5E_PLUGIN, H5E_CANTGET, "search in path %s encountered an error", H5PL_paths_g[u]);
 
         /* Break out if found */
         if (*found) {
@@ -852,7 +851,8 @@ H5PL__find_plugin_in_path(const H5PL_search_params_t *search_params, hbool_t *fo
 
     /* Open the directory */
     if (!(dirp = HDopendir(dir)))
-        HGOTO_ERROR(H5E_PLUGIN, H5E_OPENERROR, FAIL, "can't open directory: %s", dir)
+        HGOTO_ERROR(H5E_PLUGIN, H5E_OPENERROR, FAIL, "can't open directory (%s). Please verify its existence",
+                    dir)
 
     /* Iterate through all entries in the directory */
     while (NULL != (dp = HDreaddir(dirp))) {
diff --git a/src/H5PLplugin_cache.c b/src/H5PLplugin_cache.c
index cf0fd23..b74f6a1 100644
--- a/src/H5PLplugin_cache.c
+++ b/src/H5PLplugin_cache.c
@@ -273,7 +273,7 @@ H5PL__find_plugin_in_cache(const H5PL_search_params_t *search_params, hbool_t *f
 
             /* Get the "get plugin info" function from the plugin. */
             if (NULL == (get_plugin_info_function = (H5PL_get_plugin_info_t)H5PL_GET_LIB_FUNC(
-                             (H5PL_cache_g[u]).handle, "H5PLget_plugin_info")))
+                             H5PL_cache_g[u].handle, "H5PLget_plugin_info")))
                 HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, FAIL, "can't get function for H5PLget_plugin_info")
 
             /* Call the "get plugin info" function */
@@ -286,9 +286,7 @@ H5PL__find_plugin_in_cache(const H5PL_search_params_t *search_params, hbool_t *f
 
             /* No need to continue processing */
             break;
-
-        } /* end if */
-
+        }
     } /* end for */
 
 done:
diff --git a/src/H5PLpublic.h b/src/H5PLpublic.h
index a886375..8ef1c3e 100644
--- a/src/H5PLpublic.h
+++ b/src/H5PLpublic.h
@@ -17,8 +17,7 @@
 #ifndef H5PLpublic_H
 #define H5PLpublic_H
 
-/* Public headers needed by this file */
-#include "H5public.h" /* Generic Functions                    */
+#include "H5public.h" /* Generic Functions                        */
 
 /*******************/
 /* Public Typedefs */
@@ -93,9 +92,9 @@ H5_DLL herr_t H5PLset_loading_state(unsigned int plugin_control_mask);
  * \brief Queries the loadability of dynamic plugin types
  *
  * \param[out] plugin_control_mask List of dynamic plugin types that are enabled or disabled.\n
- *                                 A plugin bit set to 0 (zero) indicates that that the dynamic plugin type is
+ *                                 A plugin bit set to 0 (zero) indicates that the dynamic plugin type is
  *                                 disabled.\n
- *                                 A plugin bit set to 1 (one) indicates that that the dynamic plugin type is
+ *                                 A plugin bit set to 1 (one) indicates that the dynamic plugin type is
  *                                 enabled.\n
  *                                 If the value of \p plugin_control_mask is negative, all dynamic plugin
  *                                 types are enabled.\n
@@ -103,7 +102,7 @@ H5_DLL herr_t H5PLset_loading_state(unsigned int plugin_control_mask);
  *                                 are disabled.
  * \return \herr_t
  *
- * \details H5PLget_loading_state() retrieves the bitmask that controls whether a certain type of plugins
+ * \details H5PLget_loading_state() retrieves the bitmask that controls whether a certain type of plugin
  *          (e.g.: filters, VOL drivers) will be loaded by the HDF5 library.
  *
  *          Bit positions allocated to date are specified in \ref H5PL_type_t as follows: