Fix loading plugin fails with missing directory GH issue #3248 (#3325)

1 files changed, 31 insertions, 5 deletions

diff --git a/src/H5PLint.c b/src/H5PLint.c
index ff0be4e..6fbae7c 100644
--- a/src/H5PLint.c
+++ b/src/H5PLint.c
@@ -248,16 +248,22 @@ H5PL_load(H5PL_type_t type, H5PL_key_t key)
 
     /* Search in the table of already loaded plugin libraries */
     if (H5PL__find_plugin_in_cache(&search_params, &found, &plugin_info) < 0)
-        HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, NULL, "search in plugin cache  failed")
+        HGOTO_ERROR(H5E_PLUGIN, H5E_CANTGET, NULL, "search in plugin cache failed")
 
     /* 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)
@@ -268,9 +274,29 @@ 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. 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
  *