Remainder of vol_normalization changes (dataset, attribute, files, objects).

1 files changed, 273 insertions, 259 deletions

diff --git a/src/H5A.c b/src/H5A.c
index a0408c3..6f810be 100644
--- a/src/H5A.c
+++ b/src/H5A.c
@@ -16,22 +16,21 @@
 /****************/
 
 #include "H5Amodule.h"          /* This source code file is part of the H5A module */
-#define H5O_FRIEND		/*suppress error about including H5Opkg	*/
+#define H5O_FRIEND              /* Suppress error about including H5Opkg */
 
 
 /***********/
 /* Headers */
 /***********/
-#include "H5private.h"		/* Generic Functions			*/
-#include "H5Apkg.h"		/* Attributes				*/
-#include "H5CXprivate.h"        /* API Contexts                         */
-#include "H5Eprivate.h"		/* Error handling		  	*/
-#include "H5FLprivate.h"	/* Free Lists				*/
-#include "H5Iprivate.h"		/* IDs			  		*/
-#include "H5MMprivate.h"	/* Memory management			*/
-#include "H5Opkg.h"		/* Object headers			*/
-#include "H5Sprivate.h"		/* Dataspace functions			*/
-#include "H5SMprivate.h"	/* Shared Object Header Messages	*/
+#include "H5private.h"          /* Generic Functions                        */
+#include "H5Apkg.h"             /* Attributes                               */
+#include "H5CXprivate.h"        /* API Contexts                             */
+#include "H5Eprivate.h"         /* Error handling                           */
+#include "H5FLprivate.h"        /* Free Lists                               */
+#include "H5Iprivate.h"         /* IDs                                      */
+#include "H5MMprivate.h"        /* Memory management                        */
+#include "H5Opkg.h"             /* Object headers                           */
+#include "H5Sprivate.h"         /* Dataspace functions                      */
 
 
 /****************/
@@ -123,7 +122,7 @@ H5A__init_package(void)
      * Create attribute ID type.
      */
     if(H5I_register_type(H5I_ATTR_CLS) < 0)
-        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTINIT, FAIL, "unable to initialize interface")
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "unable to initialize interface")
 
     /* Mark "top" of interface as initialized, too */
     H5A_top_package_initialize_s = TRUE;
@@ -216,33 +215,38 @@ H5A_term_package(void)
 
 
 /*--------------------------------------------------------------------------
- NAME
-    H5Acreate2
- PURPOSE
-    Creates an attribute on an object
- USAGE
-    hid_t H5Acreate2(loc_id, attr_name, type_id, space_id, acpl_id,
-            aapl_id)
-        hid_t loc_id;       IN: Object (dataset or group) to be attached to
-        const char *attr_name;  IN: Name of attribute to locate and open
-        hid_t type_id;          IN: ID of datatype for attribute
-        hid_t space_id;         IN: ID of dataspace for attribute
-        hid_t acpl_id;          IN: ID of creation property list (currently not used)
-        hid_t aapl_id;          IN: Attribute access property list
- RETURNS
-    Non-negative on success/Negative on failure
-
- DESCRIPTION
-        This function creates an attribute which is attached to the object
-    specified with 'loc_id'.  The name specified with 'attr_name' for
-    each attribute for an object must be unique for that object.  The 'type_id'
-    and 'space_id' are created with the H5T and H5S interfaces respectively.
-    The 'aapl_id' property list is currently unused, but will be used in the
-    future for optional attribute access properties.  The attribute ID returned
-    from this function must be released with H5Aclose or resource leaks will
-    develop.
-
---------------------------------------------------------------------------*/
+ * Function:    H5Acreate2
+ *
+ * Purpose:     Creates an attribute on an object
+ *
+ * Usage:
+ *              hid_t H5Acreate2(loc_id, attr_name, type_id, space_id, acpl_id,
+ *                  aapl_id)
+ *
+ * Description: This function creates an attribute which is attached to the
+ *              object specified with 'loc_id'. The name specified with
+ *              'attr_name' for each attribute for an object must be unique
+ *              for that object. The 'type_id' and 'space_id' are created
+ *              with the H5T and H5S interfaces respectively. The 'aapl_id'
+ *              property list is currently unused, but will be used in the
+ *              future for optional attribute access properties. The
+ *              attribute ID returned from this function must be released
+ *              with H5Aclose or resource leaks will develop.
+ *
+ * Parameters:
+ *              hid_t loc_id;           IN: Object (dataset or group) to be attached to
+ *              const char *attr_name;  IN: Name of attribute to locate and open
+ *              hid_t type_id;          IN: ID of datatype for attribute
+ *              hid_t space_id;         IN: ID of dataspace for attribute
+ *              hid_t acpl_id;          IN: ID of creation property list (currently not used)
+ *              hid_t aapl_id;          IN: Attribute access property list
+ *
+ * Return:      Success:    An ID for the created attribute
+ *
+ *              Failure:    H5I_INVALID_HID
+ *
+ *-------------------------------------------------------------------------
+ */
 hid_t
 H5Acreate2(hid_t loc_id, const char *attr_name, hid_t type_id, hid_t space_id,
     hid_t acpl_id, hid_t aapl_id)
@@ -251,41 +255,44 @@ H5Acreate2(hid_t loc_id, const char *attr_name, hid_t type_id, hid_t space_id,
     H5G_loc_t           loc;                    /* Object location */
     H5T_t		*type;                  /* Datatype to use for attribute */
     H5S_t		*space;                 /* Dataspace to use for attribute */
-    hid_t		ret_value;              /* Return value */
+    hid_t           ret_value = H5I_INVALID_HID;        /* Return value                 */
 
-    FUNC_ENTER_API(FAIL)
+    FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE6("i", "i*siiii", loc_id, attr_name, type_id, space_id, acpl_id, aapl_id);
 
-    /* check arguments */
+    /* Check arguments */
     if(H5I_ATTR == H5I_get_type(loc_id))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "location is not valid for an attribute")
     if(H5G_loc(loc_id, &loc) < 0)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a location")
     if(0 == (H5F_INTENT(loc.oloc->file) & H5F_ACC_RDWR))
-	HGOTO_ERROR(H5E_ARGS, H5E_WRITEERROR, FAIL, "no write intent on file")
-    if(!attr_name || !*attr_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
+        HGOTO_ERROR(H5E_ARGS, H5E_WRITEERROR, H5I_INVALID_HID, "no write intent on file")
+    if(!attr_name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "attr_name parameter cannot be NULL")
+    if(!*attr_name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "attr_name parameter cannot be an empty string")
     if(NULL == (type = (H5T_t *)H5I_object_verify(type_id, H5I_DATATYPE)))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a type")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a type")
     if(NULL == (space = (H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE)))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataspace")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a dataspace")
 
     /* Verify access property list and set up collective metadata if appropriate */
     if(H5CX_set_apl(&aapl_id, H5P_CLS_AACC, loc_id, TRUE) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, H5I_INVALID_HID, "can't set access property list info")
 
-    /* Go do the real work for attaching the attribute to the object */
+    /* Create the attribute */
     if(NULL == (attr = H5A__create(&loc, attr_name, type, space, acpl_id)))
-	HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "unable to create attribute")
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, H5I_INVALID_HID, "unable to create attribute")
 
     /* Register the new attribute and get an ID for it */
     if((ret_value = H5I_register(H5I_ATTR, attr, TRUE)) < 0)
-        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register attribute for ID")
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize attribute handle")
 
 done:
     /* Cleanup on failure */
-    if(ret_value < 0 && attr && H5A__close(attr) < 0)
-        HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+    if(H5I_INVALID_HID == ret_value)
+        if(attr && H5A__close(attr) < 0)
+            HDONE_ERROR(H5E_ATTR, H5E_CLOSEERROR, H5I_INVALID_HID, "can't close attribute")
 
     FUNC_LEAVE_API(ret_value)
 } /* H5Acreate2() */
@@ -308,7 +315,7 @@ done:
         hid_t aapl_id;          IN: Attribute access property list
         hid_t lapl_id;          IN: Link access property list
  RETURNS
-    Non-negative on success/Negative on failure
+    Non-negative on success/H5I_INVALID_HID on failure
 
  DESCRIPTION
         This function creates an attribute which is attached to the object
@@ -330,27 +337,27 @@ H5Acreate_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     H5G_loc_t           loc;                    /* Object location */
     H5T_t		*type;                  /* Datatype to use for attribute */
     H5S_t		*space;                 /* Dataspace to use for attribute */
-    hid_t		ret_value;              /* Return value */
+    hid_t               ret_value = H5I_INVALID_HID;    /* Return value */
 
-    FUNC_ENTER_API(FAIL)
+    FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE8("i", "i*s*siiiii", loc_id, obj_name, attr_name, type_id, space_id,
              acpl_id, aapl_id, lapl_id);
 
-    /* check arguments */
+    /* Check arguments */
     if(H5I_ATTR == H5I_get_type(loc_id))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "location is not valid for an attribute")
     if(H5G_loc(loc_id, &loc) < 0)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a location")
     if(0 == (H5F_INTENT(loc.oloc->file) & H5F_ACC_RDWR))
-	HGOTO_ERROR(H5E_ARGS, H5E_WRITEERROR, FAIL, "no write intent on file")
+        HGOTO_ERROR(H5E_ARGS, H5E_WRITEERROR, H5I_INVALID_HID, "no write intent on file")
     if(!obj_name || !*obj_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no object name")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "no object name")
     if(!attr_name || !*attr_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "no attribute name")
     if(NULL == (type = (H5T_t *)H5I_object_verify(type_id, H5I_DATATYPE)))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a type")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a type")
     if(NULL == (space = (H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE)))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataspace")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a dataspace")
 
     /* Verify access property list and set up collective metadata if appropriate */
     if(H5CX_set_apl(&aapl_id, H5P_CLS_AACC, loc_id, TRUE) < 0)
@@ -358,22 +365,23 @@ H5Acreate_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
 
     if(H5P_DEFAULT != lapl_id) {
         if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
-            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not link access property list ID")
         H5CX_set_lapl(lapl_id);
-    } /* end if */
+    }
 
-    /* Create the attribute on the object */
+    /* Create the attribute */
     if(NULL == (attr = H5A__create_by_name(&loc, obj_name, attr_name, type, space, acpl_id)))
-	HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "unable to create attribute")
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, H5I_INVALID_HID, "unable to create attribute")
 
     /* Register the new attribute and get an ID for it */
     if((ret_value = H5I_register(H5I_ATTR, attr, TRUE)) < 0)
-        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register attribute for ID")
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize attribute handle")
 
 done:
     /* Cleanup on failure */
-    if(ret_value < 0 && attr && H5A__close(attr) < 0)
-        HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+    if(H5I_INVALID_HID == ret_value)
+        if(attr && H5A__close(attr) < 0)
+            HDONE_ERROR(H5E_ATTR, H5E_CLOSEERROR, H5I_INVALID_HID, "can't close attribute")
 
     FUNC_LEAVE_API(ret_value)
 } /* H5Acreate_by_name() */
@@ -390,7 +398,7 @@ done:
         const char *attr_name;  IN: Name of attribute to locate and open
         hid_t aapl_id;          IN: Attribute access property list
  RETURNS
-    ID of attribute on success, negative on failure
+    ID of attribute on success, H5I_INVALID_HID on failure
 
  DESCRIPTION
         This function opens an existing attribute for access.  The attribute
@@ -403,36 +411,38 @@ H5Aopen(hid_t loc_id, const char *attr_name, hid_t aapl_id)
 {
     H5G_loc_t    	loc;            /* Object location */
     H5A_t               *attr = NULL;   /* Attribute opened */
-    hid_t		ret_value;
+    hid_t ret_value = H5I_INVALID_HID;
 
-    FUNC_ENTER_API(FAIL)
+    FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE3("i", "i*si", loc_id, attr_name, aapl_id);
 
-    /* check arguments */
+    /* Check arguments */
     if(H5I_ATTR == H5I_get_type(loc_id))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "location is not valid for an attribute")
     if(H5G_loc(loc_id, &loc) < 0)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-    if(!attr_name || !*attr_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a location")
+    if(!attr_name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "name parameter cannot be NULL")
+    if(!*attr_name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "name parameter cannot be an empty string")
 
     /* Verify access property list and set up collective metadata if appropriate */
     if(H5CX_set_apl(&aapl_id, H5P_CLS_AACC, loc_id, FALSE) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access property list info")
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, H5I_INVALID_HID, "can't set access property list info")
 
-    /* Read in attribute from object header */
+    /* Open the attribute */
     if(NULL == (attr = H5A__open(&loc, attr_name)))
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to load attribute info from object header for attribute: '%s'", attr_name)
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, H5I_INVALID_HID, "unable to open attribute: '%s'", attr_name)
 
     /* Register the attribute and get an ID for it */
     if((ret_value = H5I_register(H5I_ATTR, attr, TRUE)) < 0)
-        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register attribute for ID")
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize attribute handle")
 
 done:
     /* Cleanup on failure */
-    if(ret_value < 0)
+    if(H5I_INVALID_HID == ret_value)
         if(attr && H5A__close(attr) < 0)
-            HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+            HDONE_ERROR(H5E_ATTR, H5E_CLOSEERROR, H5I_INVALID_HID, "can't close attribute")
 
     FUNC_LEAVE_API(ret_value)
 } /* H5Aopen() */
@@ -451,7 +461,7 @@ done:
         hid_t aapl_id;          IN: Attribute access property list
         hid_t lapl_id;          IN: Link access property list
  RETURNS
-    ID of attribute on success, negative on failure
+    ID of attribute on success, H5I_INVALID_HID on failure
 
  DESCRIPTION
         This function opens an existing attribute for access.  The attribute
@@ -465,47 +475,48 @@ H5Aopen_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
 {
     H5G_loc_t    	loc;            /* Object location */
     H5A_t               *attr = NULL;   /* Attribute opened */
-    hid_t		ret_value;
+    hid_t ret_value = H5I_INVALID_HID;
 
-    FUNC_ENTER_API(FAIL)
+    FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE5("i", "i*s*sii", loc_id, obj_name, attr_name, aapl_id, lapl_id);
 
-    /* check arguments */
+    /* Check arguments */
     if(H5I_ATTR == H5I_get_type(loc_id))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "location is not valid for an attribute")
     if(H5G_loc(loc_id, &loc) < 0)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a location")
     if(!obj_name || !*obj_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no object name")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "no object name")
     if(!attr_name || !*attr_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "no attribute name")
 
     /* Verify access property list and set up collective metadata if appropriate */
     if(H5CX_set_apl(&aapl_id, H5P_CLS_AACC, loc_id, FALSE) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access property list info")
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, H5I_INVALID_HID, "can't set access property list info")
 
+    /* Set lapl_id and add to context */
     if(H5P_DEFAULT != lapl_id) {
         if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
-            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not link access property list ID")
         H5CX_set_lapl(lapl_id);
-    } /* end if */
+    }
 
-    /* Open the attribute on the object header */
+    /* Open the attribute */
     if(NULL == (attr = H5A__open_by_name(&loc, obj_name, attr_name)))
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "can't open attribute")
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, H5I_INVALID_HID, "can't open attribute")
 
     /* Register the attribute and get an ID for it */
     if((ret_value = H5I_register(H5I_ATTR, attr, TRUE)) < 0)
-        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register attribute for ID")
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize attribute handle")
 
 done:
     /* Cleanup on failure */
-    if(ret_value < 0)
+    if(H5I_INVALID_HID == ret_value)
         if(attr && H5A__close(attr) < 0)
-            HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+            HDONE_ERROR(H5E_ATTR, H5E_CLOSEERROR, H5I_INVALID_HID, "can't close attribute")
 
     FUNC_LEAVE_API(ret_value)
-} /* H5Aopen_by_name() */
+} /* end H5Aopen_by_name() */
 
 
 /*--------------------------------------------------------------------------
@@ -524,7 +535,7 @@ done:
         hid_t aapl_id;          IN: Attribute access property list
         hid_t lapl_id;          IN: Link access property list
  RETURNS
-    ID of attribute on success, negative on failure
+    ID of attribute on success, H5I_INVALID_HID on failure
 
  DESCRIPTION
         This function opens an existing attribute for access.  The attribute
@@ -538,47 +549,48 @@ H5Aopen_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
 {
     H5A_t       *attr = NULL;   /* Attribute opened */
     H5G_loc_t	loc;	        /* Object location */
-    hid_t	ret_value;      /* Return value */
+    hid_t ret_value = H5I_INVALID_HID;                  /* Return value */
 
-    FUNC_ENTER_API(FAIL)
+    FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE7("i", "i*sIiIohii", loc_id, obj_name, idx_type, order, n, aapl_id,
              lapl_id);
 
-    /* check arguments */
+    /* Check arguments */
     if(H5I_ATTR == H5I_get_type(loc_id))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "location is not valid for an attribute")
     if(H5G_loc(loc_id, &loc) < 0)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a location")
     if(!obj_name || !*obj_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no object name")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "no object name")
     if(idx_type <= H5_INDEX_UNKNOWN || idx_type >= H5_INDEX_N)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid index type specified")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "invalid index type specified")
     if(order <= H5_ITER_UNKNOWN || order >= H5_ITER_N)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid iteration order specified")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "invalid iteration order specified")
 
     /* Verify access property list and set up collective metadata if appropriate */
     if(H5CX_set_apl(&aapl_id, H5P_CLS_AACC, loc_id, FALSE) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access property list info")
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, H5I_INVALID_HID, "can't set access property list info")
 
+    /* Set lapl_id and add to context */
     if(H5P_DEFAULT != lapl_id) {
         if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
-            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not link access property list ID")
         H5CX_set_lapl(lapl_id);
-    } /* end if */
+    }
 
-    /* Open the attribute in the object header */
+    /* Open the attribute */
     if(NULL == (attr = H5A__open_by_idx(&loc, obj_name, idx_type, order, n)))
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open attribute")
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, H5I_INVALID_HID, "unable to open attribute")
 
     /* Register the attribute and get an ID for it */
     if((ret_value = H5I_register(H5I_ATTR, attr, TRUE)) < 0)
-        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register attribute for ID")
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize attribute handle")
 
 done:
     /* Cleanup on failure */
-    if(ret_value < 0)
+    if(H5I_INVALID_HID == ret_value)
         if(attr && H5A__close(attr) < 0)
-            HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+            HDONE_ERROR(H5E_ATTR, H5E_CLOSEERROR, H5I_INVALID_HID, "can't close attribute")
 
     FUNC_LEAVE_API(ret_value)
 } /* H5Aopen_by_idx() */
@@ -603,26 +615,26 @@ done:
 herr_t
 H5Awrite(hid_t attr_id, hid_t dtype_id, const void *buf)
 {
-    H5A_t *attr;                /* Attribute object for ID */
+    H5A_t          *attr;                   /* Attribute object for ID */
     H5T_t *mem_type;            /* Memory datatype */
-    herr_t ret_value;           /* Return value */
+    herr_t          ret_value;              /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE3("e", "ii*x", attr_id, dtype_id, buf);
 
-    /* check arguments */
+    /* Check arguments */
     if(NULL == (attr = (H5A_t *)H5I_object_verify(attr_id, H5I_ATTR)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an attribute")
     if(NULL == (mem_type = (H5T_t *)H5I_object_verify(dtype_id, H5I_DATATYPE)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a datatype")
     if(NULL == buf)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "null attribute buffer")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "buf parameter can't be NULL")
 
     /* Set up collective metadata if appropriate */
     if(H5CX_set_loc(attr_id) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set collective metadata read")
 
-    /* Go write the actual data to the attribute */
+    /* Write the attribute data */
     if((ret_value = H5A__write(attr, mem_type, buf)) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_WRITEERROR, FAIL, "unable to write attribute")
 
@@ -650,22 +662,22 @@ done:
 herr_t
 H5Aread(hid_t attr_id, hid_t dtype_id, void *buf)
 {
-    H5A_t *attr;                /* Attribute object for ID */
+    H5A_t          *attr;               /* Attribute object for ID */
     H5T_t *mem_type;            /* Memory datatype */
-    herr_t ret_value;           /* Return value */
+    herr_t          ret_value;          /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE3("e", "ii*x", attr_id, dtype_id, buf);
 
-    /* check arguments */
+    /* Check arguments */
     if(NULL == (attr = (H5A_t *)H5I_object_verify(attr_id, H5I_ATTR)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an attribute")
     if(NULL == (mem_type = (H5T_t *)H5I_object_verify(dtype_id, H5I_DATATYPE)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a datatype")
     if(NULL == buf)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "null attribute buffer")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "buf parameter can't be NULL")
 
-    /* Go write the actual data to the attribute */
+    /* Read the attribute data */
     if((ret_value = H5A__read(attr, mem_type, buf)) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_READERROR, FAIL, "unable to read attribute")
 
@@ -683,7 +695,7 @@ done:
     hid_t H5Aget_space (attr_id)
         hid_t attr_id;       IN: Attribute to get dataspace of
  RETURNS
-    A dataspace ID on success, negative on failure
+    A dataspace ID on success, H5I_INVALID_HID on failure
 
  DESCRIPTION
         This function retrieves a copy of the dataspace for an attribute.
@@ -693,18 +705,20 @@ done:
 hid_t
 H5Aget_space(hid_t attr_id)
 {
-    H5A_t	*attr;                  /* Attribute object for ID */
-    hid_t	ret_value;              /* Return value */
+    H5A_t	       *attr        = NULL;                 /* Attribute object for ID */
+    hid_t           ret_value   = H5I_INVALID_HID;      /* Return value */
 
-    FUNC_ENTER_API(FAIL)
+    FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE1("i", "i", attr_id);
 
-    /* check arguments */
+    /* Check arguments */
     if(NULL == (attr = (H5A_t *)H5I_object_verify(attr_id, H5I_ATTR)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an attribute")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not an attribute")
 
+    /* Get the dataspace */
     if((ret_value = H5A_get_space(attr)) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get space ID of attribute")
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, H5I_INVALID_HID, "unable to get dataspace of attribute")
+
 done:
     FUNC_LEAVE_API(ret_value)
 } /* H5Aget_space() */
@@ -719,7 +733,7 @@ done:
     hid_t H5Aget_type (attr_id)
         hid_t attr_id;       IN: Attribute to get datatype of
  RETURNS
-    A datatype ID on success, negative on failure
+    A datatype ID on success, H5I_INVALID_HID on failure
 
  DESCRIPTION
         This function retrieves a copy of the datatype for an attribute.
@@ -729,18 +743,19 @@ done:
 hid_t
 H5Aget_type(hid_t attr_id)
 {
-    H5A_t *attr;        /* Attribute object for ID */
-    hid_t ret_value;     /* Return value */
+    H5A_t          *attr        = NULL;                 /* Attribute object for ID */
+    hid_t           ret_value   = H5I_INVALID_HID;      /* Return value */
 
-    FUNC_ENTER_API(FAIL)
+    FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE1("i", "i", attr_id);
 
-    /* check arguments */
+    /* Check arguments */
     if(NULL == (attr = (H5A_t *)H5I_object_verify(attr_id, H5I_ATTR)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an attribute")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not an attribute")
 
+    /* Get the datatype */
     if((ret_value = H5A__get_type(attr)) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get datatype ID of attribute")
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, H5I_INVALID_HID, "unable to get datatype of attribute")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -757,7 +772,7 @@ done:
         hid_t attr_id;      IN: Attribute to get name of
  RETURNS
     This function returns the ID of a copy of the attribute's creation
-    property list, or negative on failure.
+    property list, or H5I_INVALID_HID on failure.
 
  ERRORS
 
@@ -769,20 +784,21 @@ done:
 hid_t
 H5Aget_create_plist(hid_t attr_id)
 {
-    H5A_t		*attr;               /* Attribute object for ID */
-    hid_t		ret_value;
+    H5A_t		   *attr        = NULL;                 /* Attribute object for ID */
+    hid_t           ret_value   = H5I_INVALID_HID;      /* Return value */
 
-    FUNC_ENTER_API(FAIL)
+    FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE1("i", "i", attr_id);
 
     HDassert(H5P_LST_ATTRIBUTE_CREATE_ID_g != -1);
 
-    /* Get attribute and default attribute creation property list*/
+    /* Check arguments */
     if(NULL == (attr = (H5A_t *)H5I_object_verify(attr_id, H5I_ATTR)))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an attribute")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not an attribute")
 
+    /* Get the acpl */
     if((ret_value = H5A__get_create_plist(attr)) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get creation property list for attr")
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, H5I_INVALID_HID, "unable to get creation property list for attribute")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -813,21 +829,21 @@ done:
 ssize_t
 H5Aget_name(hid_t attr_id, size_t buf_size, char *buf)
 {
-    H5A_t		*my_attr;               /* Attribute object for ID */
-    ssize_t		ret_value;
+    H5A_t		       *attr        = NULL;             /* Attribute object for ID */
+    ssize_t             ret_value   = -1;
 
-    FUNC_ENTER_API(FAIL)
+    FUNC_ENTER_API((-1))
     H5TRACE3("Zs", "iz*s", attr_id, buf_size, buf);
 
     /* check arguments */
-    if(NULL == (my_attr = (H5A_t *)H5I_object_verify(attr_id, H5I_ATTR)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an attribute")
+    if(NULL == (attr = (H5A_t *)H5I_object_verify(attr_id, H5I_ATTR)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, (-1), "not an attribute")
     if(!buf && buf_size)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid buffer")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, (-1), "buf cannot be NULL if buf_size is non-zero")
 
-    /* Call private function in turn */
-    if(0 > (ret_value = H5A__get_name(my_attr, buf_size, buf)))
-	HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "can't get attribute name")
+    /* Get the attribute name */
+    if((ret_value = H5A__get_name(attr, buf_size, buf)) < 0)
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, (-1), "unable to get attribute name")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -866,15 +882,15 @@ H5Aget_name_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
 
     /* Check args */
     if(H5I_ATTR == H5I_get_type(loc_id))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
     if(H5G_loc(loc_id, &loc) < 0)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!obj_name || !*obj_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
     if(idx_type <= H5_INDEX_UNKNOWN || idx_type >= H5_INDEX_N)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid index type specified")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid index type specified")
     if(order <= H5_ITER_UNKNOWN || order >= H5_ITER_N)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid iteration order specified")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid iteration order specified")
 
     /* Verify access property list and set up collective metadata if appropriate */
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
@@ -887,12 +903,12 @@ H5Aget_name_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     /* Get the length of the name */
     ret_value = (ssize_t)HDstrlen(attr->shared->name);
 
-    /* Copy the name into the user's buffer, if given */
+    /* Get the name and store in the user's buffer */
     if(name) {
         HDstrncpy(name, attr->shared->name, MIN((size_t)(ret_value + 1), size));
         if((size_t)ret_value >= size)
             name[size - 1]='\0';
-    } /* end if */
+    }
 
 done:
     /* Release resources */
@@ -929,11 +945,11 @@ H5Aget_storage_size(hid_t attr_id)
     FUNC_ENTER_API(0)
     H5TRACE1("h", "i", attr_id);
 
-    /* Check args */
+    /* Check arguments */
     if(NULL == (attr = (H5A_t *)H5I_object_verify(attr_id, H5I_ATTR)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "not an attribute")
 
-    /* Set return value */
+    /* Get the storage size */
     ret_value = attr->shared->data_size;
 
 done:
@@ -963,13 +979,13 @@ H5Aget_info(hid_t attr_id, H5A_info_t *ainfo)
     FUNC_ENTER_API(FAIL)
     H5TRACE2("e", "i*x", attr_id, ainfo);
 
-    /* Check args */
+    /* Check arguments */
     if(NULL == (attr = (H5A_t *)H5I_object_verify(attr_id, H5I_ATTR)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an attribute")
 
     /* Get the attribute information */
     if(H5A__get_info(attr, ainfo) < 0)
-	HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to get attribute info")
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to get attribute info")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -1002,13 +1018,13 @@ H5Aget_info_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
 
     /* Check args */
     if(H5I_ATTR == H5I_get_type(loc_id))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
     if(H5G_loc(loc_id, &loc) < 0)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!obj_name || !*obj_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no object name")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no object name")
     if(!attr_name || !*attr_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
     if(NULL == ainfo)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid info pointer")
 
@@ -1022,7 +1038,7 @@ H5Aget_info_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
 
     /* Get the attribute information */
     if(H5A__get_info(attr, ainfo) < 0)
-	HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to get attribute info")
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to get attribute info")
 
 done:
     /* Release resources */
@@ -1061,15 +1077,15 @@ H5Aget_info_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
 
     /* Check args */
     if(H5I_ATTR == H5I_get_type(loc_id))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
     if(H5G_loc(loc_id, &loc) < 0)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!obj_name || !*obj_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
     if(idx_type <= H5_INDEX_UNKNOWN || idx_type >= H5_INDEX_N)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid index type specified")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid index type specified")
     if(order <= H5_ITER_UNKNOWN || order >= H5_ITER_N)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid iteration order specified")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid iteration order specified")
     if(NULL == ainfo)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid info pointer")
 
@@ -1083,7 +1099,7 @@ H5Aget_info_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
 
     /* Get the attribute information */
     if(H5A__get_info(attr, ainfo) < 0)
-	HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to get attribute info")
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to get attribute info")
 
 done:
     /* Release resources */
@@ -1095,12 +1111,11 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Arename
+ * Function:    H5Arename
  *
  * Purpose:     Rename an attribute
  *
- * Return:	Success:             Non-negative
- *		Failure:             Negative
+ * Return:      SUCCEED/FAIL
  *
  * Programmer:	Raymond Lu
  *              October 23, 2002
@@ -1117,25 +1132,25 @@ H5Arename(hid_t loc_id, const char *old_name, const char *new_name)
 
     /* check arguments */
     if(!old_name || !new_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "name is nil")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "name is nil")
     if(H5I_ATTR == H5I_get_type(loc_id))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
 
     /* Avoid thrashing things if the names are the same */
     if(HDstrcmp(old_name, new_name)) {
         H5G_loc_t loc;                /* Object location */
   
         if(H5G_loc(loc_id, &loc) < 0)
-            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
 
-    /* Set up collective metadata if appropriate */
-    if(H5CX_set_loc(loc_id) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set collective metadata read")
+        /* Set up collective metadata if appropriate */
+        if(H5CX_set_loc(loc_id) < 0)
+            HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set collective metadata read")
 
-        /* Call private attribute rename routine */
+        /* Rename the attribute */
         if(H5O__attr_rename(loc.oloc, old_name, new_name) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTRENAME, FAIL, "can't rename attribute")
-    } /* end if */
+    }
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -1143,12 +1158,11 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Arename_by_name
+ * Function:    H5Arename_by_name
  *
  * Purpose:     Rename an attribute
  *
- * Return:	Success:             Non-negative
- *		Failure:             Negative
+ * Return:      SUCCEED/FAIL
  *
  * Programmer:	Quincey Koziol
  *              February 20, 2007
@@ -1167,13 +1181,13 @@ H5Arename_by_name(hid_t loc_id, const char *obj_name, const char *old_attr_name,
 
     /* check arguments */
     if(H5I_ATTR == H5I_get_type(loc_id))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
     if(!obj_name || !*obj_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no object name")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no object name")
     if(!old_attr_name || !*old_attr_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no old attribute name")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no old attribute name")
     if(!new_attr_name || !*new_attr_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no new attribute name")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no new attribute name")
 
     /* Avoid thrashing things if the names are the same */
     if(HDstrcmp(old_attr_name, new_attr_name)) {
@@ -1183,13 +1197,14 @@ H5Arename_by_name(hid_t loc_id, const char *obj_name, const char *old_attr_name,
         if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, TRUE) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access property list info")
 
+        /* Get the location object */
         if(H5G_loc(loc_id, &loc) < 0)
-            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
 
-        /* Call private attribute rename routine */
+        /* Rename the attribute */
         if(H5A__rename_by_name(loc, obj_name, old_attr_name, new_attr_name) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTRENAME, FAIL, "can't rename attribute")
-    } /* end if */
+    }
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -1248,15 +1263,15 @@ H5Aiterate2(hid_t loc_id, H5_index_t idx_type, H5_iter_order_t order,
 
     /* check arguments */
     if(H5I_ATTR == H5I_get_type(loc_id))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
     if(idx_type <= H5_INDEX_UNKNOWN || idx_type >= H5_INDEX_N)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid index type specified")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid index type specified")
     if(order <= H5_ITER_UNKNOWN || order >= H5_ITER_N)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid iteration order specified")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid iteration order specified")
 
-    /* Call attribute iteration routine */
+    /* Iterate over attributes */
     if((ret_value = H5A__iterate(loc_id, idx_type, order, idx, op, op_data)) < 0)
-        HERROR(H5E_ATTR, H5E_BADITER, "error iterating over attributes");
+        HGOTO_ERROR(H5E_ATTR, H5E_BADITER, FAIL, "error iterating over attributes")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -1312,7 +1327,7 @@ H5Aiterate_by_name(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     hid_t lapl_id)
 {
     H5G_loc_t	loc;	        /* Object location */
-    herr_t	ret_value;      /* Return value */
+    herr_t   ret_value = SUCCEED;      /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE8("e", "i*sIiIo*hx*xi", loc_id, obj_name, idx_type, order, idx, op,
@@ -1320,23 +1335,23 @@ H5Aiterate_by_name(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
 
     /* check arguments */
     if(H5I_ATTR == H5I_get_type(loc_id))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
     if(H5G_loc(loc_id, &loc) < 0)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!obj_name || !*obj_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no object name")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no object name")
     if(idx_type <= H5_INDEX_UNKNOWN || idx_type >= H5_INDEX_N)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid index type specified")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid index type specified")
     if(order <= H5_ITER_UNKNOWN || order >= H5_ITER_N)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid iteration order specified")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid iteration order specified")
 
     /* Verify access property list and set up collective metadata if appropriate */
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access property list info")
 
-    /* Call attribute iteration by name routine */
+    /* Iterate over attributes */
     if((ret_value = H5A__iterate_by_name(&loc, obj_name, idx_type, order, idx, op, op_data)) < 0)
-        HERROR(H5E_ATTR, H5E_BADITER, "error iterating over attributes");
+        HGOTO_ERROR(H5E_ATTR, H5E_BADITER, FAIL, "attribute iteration failed");
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -1361,24 +1376,26 @@ herr_t
 H5Adelete(hid_t loc_id, const char *name)
 {
     H5G_loc_t	loc;		        /* Object location */
-    herr_t	ret_value = SUCCEED;    /* Return value */
+    herr_t	            ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE2("e", "i*s", loc_id, name);
 
-    /* check arguments */
+    /* Check arguments */
     if(H5I_ATTR == H5I_get_type(loc_id))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
     if(H5G_loc(loc_id, &loc) < 0)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-    if(!name || !*name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+    if(!name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "name parameter cannot be NULL")
+    if(!*name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "name parameter cannot be an empty string")
 
     /* Set up collective metadata if appropriate */
     if(H5CX_set_loc(loc_id) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set collective metadata read")
 
-    /* Delete the attribute from the location */
+    /* Delete the attribute */
     if(H5O__attr_remove(loc.oloc, name) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
 
@@ -1413,21 +1430,21 @@ H5Adelete_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     FUNC_ENTER_API(FAIL)
     H5TRACE4("e", "i*s*si", loc_id, obj_name, attr_name, lapl_id);
 
-    /* check arguments */
+    /* Check arguments */
     if(H5I_ATTR == H5I_get_type(loc_id))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
     if(H5G_loc(loc_id, &loc) < 0)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!obj_name || !*obj_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no object name")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no object name")
     if(!attr_name || !*attr_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
 
     /* Verify access property list and set up collective metadata if appropriate */
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, TRUE) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access property list info")
 
-    /* Delete the attribute from the location */
+    /* Delete the attribute */
     if(H5A__delete_by_name(&loc, obj_name, attr_name) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
 
@@ -1472,15 +1489,15 @@ H5Adelete_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
 
     /* check arguments */
     if(H5I_ATTR == H5I_get_type(loc_id))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
     if(H5G_loc(loc_id, &loc) < 0)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!obj_name || !*obj_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no object name")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no object name")
     if(idx_type <= H5_INDEX_UNKNOWN || idx_type >= H5_INDEX_N)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid index type specified")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid index type specified")
     if(order <= H5_ITER_UNKNOWN || order >= H5_ITER_N)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid iteration order specified")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid iteration order specified")
 
     /* Verify access property list and set up collective metadata if appropriate */
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, TRUE) < 0)
@@ -1495,21 +1512,17 @@ done:
 } /* H5Adelete_by_idx() */
 
 
-/*--------------------------------------------------------------------------
- NAME
-    H5Aclose
- PURPOSE
-    Close an attribute ID
- USAGE
-    herr_t H5Aclose (attr_id)
-        hid_t attr_id;       IN: Attribute to release access to
- RETURNS
-    Non-negative on success/Negative on failure
-
- DESCRIPTION
-        This function releases an attribute from use.  Further use of the
-    attribute ID will result in undefined behavior.
---------------------------------------------------------------------------*/
+/*-------------------------------------------------------------------------
+ * Function:    H5Aclose
+ *
+ * Purpose:     Closes access to an attribute and releases resources used by
+ *              it. It is illegal to subsequently use that same dataset
+ *              ID in calls to other attribute functions.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
 herr_t
 H5Aclose(hid_t attr_id)
 {
@@ -1518,7 +1531,7 @@ H5Aclose(hid_t attr_id)
     FUNC_ENTER_API(FAIL)
     H5TRACE1("e", "i", attr_id);
 
-    /* check arguments */
+    /* Check arguments */
     if(NULL == H5I_object_verify(attr_id, H5I_ATTR))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an attribute")
 
@@ -1554,12 +1567,12 @@ H5Aexists(hid_t obj_id, const char *attr_name)
     FUNC_ENTER_API(FAIL)
     H5TRACE2("t", "i*s", obj_id, attr_name);
 
-    /* check arguments */
-    if (H5I_ATTR == H5I_get_type(obj_id))
+    /* Check arguments */
+    if(H5I_ATTR == H5I_get_type(obj_id))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
-    if (H5G_loc(obj_id, &loc) < 0)
+    if(H5G_loc(obj_id, &loc) < 0)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-    if (!attr_name || !*attr_name)
+    if(!attr_name || !*attr_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
 
     /* Check if the attribute exists */
@@ -1595,20 +1608,21 @@ H5Aexists_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     H5TRACE4("t", "i*s*si", loc_id, obj_name, attr_name, lapl_id);
 
     /* check arguments */
-    if (H5I_ATTR == H5I_get_type(loc_id))
+    if(H5I_ATTR == H5I_get_type(loc_id))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
-    if (H5G_loc(loc_id, &loc) < 0)
+    if(H5G_loc(loc_id, &loc) < 0)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-    if (!obj_name || !*obj_name)
+    if(!obj_name || !*obj_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no object name")
-    if (!attr_name || !*attr_name)
+    if(!attr_name || !*attr_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
 
     /* Verify access property list and set up collective metadata if appropriate */
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access property list info")
 
-    if ((ret_value = H5A__exists_by_name(loc, obj_name, attr_name)) < 0)
+    /* Check existence of attribute */
+    if((ret_value = H5A__exists_by_name(loc, obj_name, attr_name)) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to determine if attribute exists")
 
 done: