[svn-r460] Changes since 19980707

----------------------

./bin/trace
./src/H5.c
./src/H5private.h
./src/H5A.c
./src/H5D.c
./src/H5F.c
./src/H5G.c
./src/H5P.c
./src/H5Pprivate.h
./src/H5S.c
./src/H5T.c
	Output-only arguments have their addresses printed during
	tracing and added symbolic output for the H5F_driver_t
	arguments.  That's another reason that we should be careful to
	add `/*out*/' after arguments that are output-only and
	`/*in,out*/' after arguments that are used for both input and
	output values.

	No internal function calls H5Pget_class() anymore.

./src/H5T.c
./src/H5Tconv.c
./src/H5Tpkg.h
./src/H5Tpublic.h
	Added H5Tget_overflow() and H5Tset_overflow() so the
	application can query or set a function that will be called
	whenever an overflow occurs.  Implemented as documented in
	previous e-mail except the overflow handler gets two buffers:
	one that contains the source value and one to receive the
	optional destination value.

./test/dtypes.c
	Tests overflow handler.

./src/H5.c
	We have to declare fdopen() because I'm getting errors when
	compiling on Irix64 even though we include <stdio.h> as
	documented in the fdopen() man page.

14 files changed, 397 insertions, 150 deletions

diff --git a/src/H5.c b/src/H5.c
index 8f770b9..dd185b1 100644
--- a/src/H5.c
+++ b/src/H5.c
@@ -42,6 +42,9 @@ static char             RcsId[] = "@(#)$Revision$";
 #include <sys/time.h>
 #include <sys/resource.h>
 
+/* We need this on Irix64 even though we've included stdio.h as documented */
+FILE *fdopen(int fd, const char *mode);
+
 /* private headers */
 #include <H5private.h>          /*library                 		*/
 #include <H5ACprivate.h>        /*cache                           	*/
@@ -95,7 +98,7 @@ H5_init_library(void)
 	const char *s = getenv ("HDF5_TRACE");
 	if (s && isdigit(*s)) {
 	    int fd = HDstrtol (s, NULL, 0);
-	    H5_trace_g = fdopen (fd, "w");
+	    H5_trace_g = HDfdopen (fd, "w");
 	}
     }
 #endif
@@ -1123,6 +1126,48 @@ H5_trace (hbool_t returning, const char *func, const char *type, ...)
 	    }
 	    break;
 
+	case 'F':
+	    switch (type[1]) {
+	    case 'd':
+		if (ptr) {
+		    fprintf(out, "0x%lx", (unsigned long)vp);
+		} else {
+		    H5F_driver_t driver = va_arg(ap, H5F_driver_t);
+		    switch (driver) {
+		    case H5F_LOW_ERROR:
+			fprintf(out, "H5F_LOW_ERROR");
+			break;
+		    case H5F_LOW_STDIO:
+			fprintf(out, "H5F_LOW_STDIO");
+			break;
+		    case H5F_LOW_SEC2:
+			fprintf(out, "H5F_LOW_SEC2");
+			break;
+		    case H5F_LOW_MPIO:
+			fprintf(out, "H5F_LOW_MPIO");
+			break;
+		    case H5F_LOW_CORE:
+			fprintf(out, "H5F_LOW_CORE");
+			break;
+		    case H5F_LOW_SPLIT:
+			fprintf(out, "H5F_LOW_SPLIT");
+			break;
+		    case H5F_LOW_FAMILY:
+			fprintf(out, "H5F_LOW_FAMILY");
+			break;
+		    default:
+			fprintf(out, "%ld", (long)driver);
+			break;
+		    }
+		}
+		break;
+
+	    default:
+		fprintf(out, "BADTYPE(F%c)", type[1]);
+		goto error;
+	    }
+	    break;
+
 	case 'G':
 	    switch (type[1]) {
 	    case 'l':
diff --git a/src/H5A.c b/src/H5A.c
index 0d97803..8b7cfe6 100644
--- a/src/H5A.c
+++ b/src/H5A.c
@@ -195,7 +195,7 @@ H5Acreate (hid_t loc_id, const char *name, hid_t datatype, hid_t dataspace,
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a data space");
     }
     if (H5P_DEFAULT!=create_plist &&
-	(H5P_DATASET_CREATE != H5Pget_class(create_plist) ||
+	(H5P_DATASET_CREATE != H5P_get_class(create_plist) ||
 	 NULL == H5I_object(create_plist))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a dataset creation property list");
diff --git a/src/H5D.c b/src/H5D.c
index 653d8e3..f232785 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -209,7 +209,7 @@ H5Dcreate (hid_t loc_id, const char *name, hid_t type_id, hid_t space_id,
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a data space");
     }
     if (create_parms_id >= 0) {
-	if (H5P_DATASET_CREATE != H5Pget_class(create_parms_id) ||
+	if (H5P_DATASET_CREATE != H5P_get_class(create_parms_id) ||
 	    NULL == (create_parms = H5I_object(create_parms_id))) {
 	    HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 			  "not a dataset creation property list");
@@ -552,8 +552,8 @@ H5Dread (hid_t dataset_id, hid_t mem_type_id, hid_t mem_space_id,
     const H5D_xfer_t	   *xfer_parms = NULL;
 
     FUNC_ENTER(H5Dread, FAIL);
-    H5TRACE5("e","iiiii",dataset_id,mem_type_id,mem_space_id,file_space_id,
-             xfer_parms_id);
+    H5TRACE6("e","iiiiix",dataset_id,mem_type_id,mem_space_id,file_space_id,
+             xfer_parms_id,buf);
 
     /* check arguments */
     if (H5_DATASET != H5I_group(dataset_id) ||
@@ -579,7 +579,7 @@ H5Dread (hid_t dataset_id, hid_t mem_type_id, hid_t mem_space_id,
     }
     if (H5P_DEFAULT == xfer_parms_id) {
 	xfer_parms = &H5D_xfer_dflt;
-    } else if (H5P_DATASET_XFER != H5Pget_class(xfer_parms_id) ||
+    } else if (H5P_DATASET_XFER != H5P_get_class(xfer_parms_id) ||
 	       NULL == (xfer_parms = H5I_object(xfer_parms_id))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not xfer parms");
     }
@@ -670,7 +670,7 @@ H5Dwrite (hid_t dataset_id, hid_t mem_type_id, hid_t mem_space_id,
     }
     if (H5P_DEFAULT == xfer_parms_id) {
 	xfer_parms = &H5D_xfer_dflt;
-    } else if (H5P_DATASET_XFER != H5Pget_class(xfer_parms_id) ||
+    } else if (H5P_DATASET_XFER != H5P_get_class(xfer_parms_id) ||
 	       NULL == (xfer_parms = H5I_object(xfer_parms_id))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not xfer parms");
     }
diff --git a/src/H5E.c b/src/H5E.c
index 1344b65..eb02ba6 100644
--- a/src/H5E.c
+++ b/src/H5E.c
@@ -223,7 +223,7 @@ herr_t
 H5Eclear (void)
 {
     FUNC_ENTER (H5Eclear, FAIL);
-    H5TRACE0("e", "");
+    H5TRACE0("e","");
     /* FUNC_ENTER() does all the work */
     FUNC_LEAVE (SUCCEED);
 }
diff --git a/src/H5F.c b/src/H5F.c
index 4914408..e946b17 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -1153,14 +1153,14 @@ H5Fcreate (const char *filename, unsigned flags, hid_t create_id,
     }
     if (H5P_DEFAULT==create_id) {
 	create_parms = &H5F_create_dflt;
-    } else if (H5P_FILE_CREATE!=H5Pget_class (create_id) ||
+    } else if (H5P_FILE_CREATE!=H5P_get_class (create_id) ||
 	       NULL == (create_parms = H5I_object(create_id))) {
 	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		    "not a file creation property list");
     }
     if (H5P_DEFAULT==access_id) {
 	access_parms = &H5F_access_dflt;
-    } else if (H5P_FILE_ACCESS!=H5Pget_class (access_id) ||
+    } else if (H5P_FILE_ACCESS!=H5P_get_class (access_id) ||
 	       NULL == (access_parms = H5I_object(access_id))) {
 	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		    "not a file access property list");
@@ -1259,7 +1259,7 @@ H5Fopen (const char *filename, unsigned flags, hid_t access_id)
     }
     if (H5P_DEFAULT==access_id) {
 	access_parms = &H5F_access_dflt;
-    } else if (H5P_FILE_ACCESS!=H5Pget_class (access_id) ||
+    } else if (H5P_FILE_ACCESS!=H5P_get_class (access_id) ||
 	       NULL == (access_parms = H5I_object(access_id))) {
 	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		    "not a file access property list");
diff --git a/src/H5G.c b/src/H5G.c
index f1e65fb..7e279a5 100644
--- a/src/H5G.c
+++ b/src/H5G.c
@@ -654,7 +654,7 @@ H5Gstat (hid_t loc_id, const char *name, hbool_t follow_link,
     H5G_t	*loc = NULL;
     
     FUNC_ENTER (H5Gstat, FAIL);
-    H5TRACE3("e","isb",loc_id,name,follow_link);
+    H5TRACE4("e","isbx",loc_id,name,follow_link,statbuf);
 
     /* Check arguments */
     if (NULL==(loc=H5G_loc (loc_id))) {
@@ -697,7 +697,7 @@ H5Gget_linkval (hid_t loc_id, const char *name, size_t size, char *buf/*out*/)
     H5G_t	*loc = NULL;
     
     FUNC_ENTER (H5Gget_linkval, FAIL);
-    H5TRACE3("e","isz",loc_id,name,size);
+    H5TRACE4("e","iszx",loc_id,name,size,buf);
 
     /* Check arguments */
     if (NULL==(loc=H5G_loc (loc_id))) {
diff --git a/src/H5P.c b/src/H5P.c
index 94aff95..459e7d6 100644
--- a/src/H5P.c
+++ b/src/H5P.c
@@ -263,7 +263,7 @@ H5Pclose (hid_t tid)
     H5TRACE1("e","i",tid);
 
     /* Check arguments */
-    if ((type=H5Pget_class (tid))<0 ||
+    if ((type=H5P_get_class (tid))<0 ||
 	NULL==(tmpl=H5I_object (tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list");
     }
@@ -381,12 +381,13 @@ H5P_close (H5P_class_t type, void *tmpl)
  *-------------------------------------------------------------------------
  */
 H5P_class_t
-H5Pget_class(hid_t tid)
+H5Pget_class (hid_t tid)
 {
     H5I_group_t		    group;
     H5P_class_t		    ret_value = H5P_NO_CLASS;
 
     FUNC_ENTER(H5Pget_class, H5P_NO_CLASS);
+    H5TRACE1("p","i",tid);
 
     if ((group = H5I_group(tid)) < 0 ||
 #ifndef NDEBUG
@@ -399,6 +400,44 @@ H5Pget_class(hid_t tid)
     ret_value = (H5P_class_t)(group - H5_TEMPLATE_0);
     FUNC_LEAVE(ret_value);
 }
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5P_get_class
+ *
+ * Purpose:	Internal function for getting the property list class.
+ *
+ * Return:	Success:	A property list class
+ *
+ *		Failure:	H5P_NO_CLASS (-1)
+ *
+ * Programmer:	Robb Matzke
+ *              Tuesday, July  7, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+H5P_class_t
+H5P_get_class(hid_t tid)
+{
+    H5I_group_t		    group;
+    H5P_class_t		    ret_value = H5P_NO_CLASS;
+
+    FUNC_ENTER(H5P_get_class, H5P_NO_CLASS);
+
+    if ((group = H5I_group(tid)) < 0 ||
+#ifndef NDEBUG
+	group >= H5_TEMPLATE_MAX ||
+#endif
+	group < H5_TEMPLATE_0) {
+	HRETURN_ERROR(H5E_ATOM, H5E_BADATOM, H5P_NO_CLASS,
+		      "not a property list");
+    }
+    ret_value = (H5P_class_t)(group - H5_TEMPLATE_0);
+    FUNC_LEAVE(ret_value);
+}
+    
 
 /*-------------------------------------------------------------------------
  * Function:	H5Pget_version
@@ -433,10 +472,10 @@ H5Pget_version (hid_t tid, int *boot/*out*/, int *freelist/*out*/,
     H5F_create_t	   *tmpl = NULL;
 
     FUNC_ENTER(H5Pget_version, FAIL);
-    H5TRACE1("e","i",tid);
+    H5TRACE5("e","ixxxx",tid,boot,freelist,stab,shhdr);
 
     /* Check arguments */
-    if (H5P_FILE_CREATE != H5Pget_class(tid) ||
+    if (H5P_FILE_CREATE != H5P_get_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a file creation property list");
@@ -477,7 +516,7 @@ H5Pset_userblock (hid_t tid, hsize_t size)
     H5TRACE2("e","ih",tid,size);
 
     /* Check arguments */
-    if (H5P_FILE_CREATE != H5Pget_class(tid) ||
+    if (H5P_FILE_CREATE != H5P_get_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a file creation property list");
@@ -522,7 +561,7 @@ H5Pget_userblock (hid_t tid, hsize_t *size)
     H5TRACE2("e","i*h",tid,size);
 
     /* Check args */
-    if (H5P_FILE_CREATE != H5Pget_class(tid) ||
+    if (H5P_FILE_CREATE != H5P_get_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a file creation property list");
@@ -571,7 +610,7 @@ H5Pset_alignment (hid_t fapl_id, hsize_t threshold, hsize_t alignment)
     H5TRACE3("e","ihh",fapl_id,threshold,alignment);
 
     /* Check args */
-    if (H5P_FILE_ACCESS != H5Pget_class (fapl_id) ||
+    if (H5P_FILE_ACCESS != H5P_get_class (fapl_id) ||
 	NULL == (fapl = H5I_object (fapl_id))) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
 		       "not a file access property list");
@@ -614,10 +653,10 @@ H5Pget_alignment (hid_t fapl_id, hsize_t *threshold/*out*/,
     H5F_access_t	*fapl = NULL;
 
     FUNC_ENTER (H5Pget_alignment, FAIL);
-    H5TRACE1("e","i",fapl_id);
+    H5TRACE3("e","ixx",fapl_id,threshold,alignment);
 
     /* Check args */
-    if (H5P_FILE_ACCESS != H5Pget_class (fapl_id) ||
+    if (H5P_FILE_ACCESS != H5P_get_class (fapl_id) ||
 	NULL == (fapl = H5I_object (fapl_id))) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
 		       "not a file access property list");
@@ -658,7 +697,7 @@ H5Pset_sizes (hid_t tid, size_t sizeof_addr, size_t sizeof_size)
     H5TRACE3("e","izz",tid,sizeof_addr,sizeof_size);
 
     /* Check arguments */
-    if (H5P_FILE_CREATE != H5Pget_class(tid) ||
+    if (H5P_FILE_CREATE != H5P_get_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a file creation property list");
@@ -711,10 +750,10 @@ H5Pget_sizes (hid_t tid,
     H5F_create_t	   *tmpl = NULL;
 
     FUNC_ENTER(H5Pget_sizes, FAIL);
-    H5TRACE1("e","i",tid);
+    H5TRACE3("e","ixx",tid,sizeof_addr,sizeof_size);
 
     /* Check args */
-    if (H5P_FILE_CREATE != H5Pget_class(tid) ||
+    if (H5P_FILE_CREATE != H5P_get_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a file creation property list");
@@ -766,7 +805,7 @@ H5Pset_sym_k (hid_t tid, int ik, int lk)
     H5TRACE3("e","iIsIs",tid,ik,lk);
 
     /* Check arguments */
-    if (H5P_FILE_CREATE != H5Pget_class(tid) ||
+    if (H5P_FILE_CREATE != H5P_get_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a file creation property list");
@@ -806,10 +845,10 @@ H5Pget_sym_k (hid_t tid, int *ik /*out */ , int *lk /*out */ )
     H5F_create_t	   *tmpl = NULL;
 
     FUNC_ENTER(H5Pget_sym_k, FAIL);
-    H5TRACE1("e","i",tid);
+    H5TRACE3("e","ixx",tid,ik,lk);
 
     /* Check arguments */
-    if (H5P_FILE_CREATE != H5Pget_class(tid) ||
+    if (H5P_FILE_CREATE != H5P_get_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a file creation property list");
@@ -850,7 +889,7 @@ H5Pset_istore_k (hid_t tid, int ik)
     H5TRACE2("e","iIs",tid,ik);
 
     /* Check arguments */
-    if (H5P_FILE_CREATE != H5Pget_class(tid) ||
+    if (H5P_FILE_CREATE != H5P_get_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a file creation property list");
@@ -889,10 +928,10 @@ H5Pget_istore_k (hid_t tid, int *ik /*out */ )
     H5F_create_t	   *tmpl = NULL;
 
     FUNC_ENTER(H5Pget_istore_k, FAIL);
-    H5TRACE1("e","i",tid);
+    H5TRACE2("e","ix",tid,ik);
 
     /* Check arguments */
-    if (H5P_FILE_CREATE != H5Pget_class(tid) ||
+    if (H5P_FILE_CREATE != H5P_get_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a file creation property list");
@@ -929,7 +968,7 @@ H5Pset_layout (hid_t tid, H5D_layout_t layout)
     H5TRACE2("e","iDl",tid,layout);
 
     /* Check arguments */
-    if (H5P_DATASET_CREATE != H5Pget_class(tid) ||
+    if (H5P_DATASET_CREATE != H5P_get_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a dataset creation property list");
@@ -961,14 +1000,15 @@ H5Pset_layout (hid_t tid, H5D_layout_t layout)
  *-------------------------------------------------------------------------
  */
 H5D_layout_t
-H5Pget_layout(hid_t tid)
+H5Pget_layout (hid_t tid)
 {
     H5D_create_t	   *tmpl = NULL;
 
     FUNC_ENTER(H5Pget_layout, H5D_LAYOUT_ERROR);
+    H5TRACE1("Dl","i",tid);
 
     /* Check arguments */
-    if (H5P_DATASET_CREATE != H5Pget_class(tid) ||
+    if (H5P_DATASET_CREATE != H5P_get_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, H5D_LAYOUT_ERROR,
 		      "not a dataset creation property list");
@@ -1007,7 +1047,7 @@ H5Pset_chunk (hid_t tid, int ndims, const hsize_t dim[])
     H5TRACE3("e","iIs*h",tid,ndims,dim);
 
     /* Check arguments */
-    if (H5P_DATASET_CREATE != H5Pget_class(tid) ||
+    if (H5P_DATASET_CREATE != H5P_get_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a dataset creation property list");
@@ -1067,10 +1107,10 @@ H5Pget_chunk (hid_t tid, int max_ndims, hsize_t dim[]/*out*/)
     H5D_create_t	*tmpl = NULL;
 
     FUNC_ENTER(H5Pget_chunk, FAIL);
-    H5TRACE2("Is","iIs",tid,max_ndims);
+    H5TRACE3("Is","iIsx",tid,max_ndims,dim);
 
     /* Check arguments */
-    if (H5P_DATASET_CREATE != H5Pget_class(tid) ||
+    if (H5P_DATASET_CREATE != H5P_get_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a dataset creation property list");
@@ -1125,7 +1165,7 @@ H5Pset_external (hid_t plist_id, const char *name, off_t offset, hsize_t size)
     H5TRACE4("e","isoh",plist_id,name,offset,size);
 
     /* Check arguments */
-    if (H5P_DATASET_CREATE != H5Pget_class(plist_id) ||
+    if (H5P_DATASET_CREATE != H5P_get_class(plist_id) ||
 	NULL == (plist = H5I_object(plist_id))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a dataset creation property list");
@@ -1205,7 +1245,7 @@ H5Pget_external_count (hid_t plist_id)
     H5TRACE1("Is","i",plist_id);
     
     /* Check arguments */
-    if (H5P_DATASET_CREATE != H5Pget_class(plist_id) ||
+    if (H5P_DATASET_CREATE != H5P_get_class(plist_id) ||
 	NULL == (plist = H5I_object(plist_id))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a dataset creation property list");
@@ -1251,10 +1291,10 @@ H5Pget_external (hid_t plist_id, int idx, size_t name_size, char *name/*out*/,
     H5D_create_t	*plist = NULL;
     
     FUNC_ENTER (H5Pget_external, FAIL);
-    H5TRACE3("e","iIsz",plist_id,idx,name_size);
+    H5TRACE6("e","iIszxxx",plist_id,idx,name_size,name,offset,size);
     
     /* Check arguments */
-    if (H5P_DATASET_CREATE != H5Pget_class(plist_id) ||
+    if (H5P_DATASET_CREATE != H5P_get_class(plist_id) ||
 	NULL == (plist = H5I_object(plist_id))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a dataset creation property list");
@@ -1298,9 +1338,10 @@ H5Pget_driver (hid_t tid)
     H5F_access_t	*tmpl = NULL;
 
     FUNC_ENTER (H5Pget_driver, H5F_LOW_ERROR);
+    H5TRACE1("Fd","i",tid);
 
     /* Check arguments */
-    if (H5P_FILE_ACCESS != H5Pget_class (tid) ||
+    if (H5P_FILE_ACCESS != H5P_get_class (tid) ||
 	NULL == (tmpl = H5I_object (tid))) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, H5F_LOW_ERROR,
 		       "not a file access property list");
@@ -1337,7 +1378,7 @@ H5Pset_stdio (hid_t tid)
     H5TRACE1("e","i",tid);
 
     /* Check arguments */
-    if (H5P_FILE_ACCESS != H5Pget_class(tid) ||
+    if (H5P_FILE_ACCESS != H5P_get_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a file access property list");
@@ -1378,7 +1419,7 @@ H5Pget_stdio (hid_t tid)
     H5TRACE1("e","i",tid);
 
     /* Check arguments */
-    if (H5P_FILE_ACCESS != H5Pget_class (tid) ||
+    if (H5P_FILE_ACCESS != H5P_get_class (tid) ||
 	NULL == (tmpl = H5I_object (tid))) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
 		       "not a file access property list");
@@ -1419,7 +1460,7 @@ H5Pset_sec2 (hid_t tid)
     H5TRACE1("e","i",tid);
 
     /* Check arguments */
-    if (H5P_FILE_ACCESS != H5Pget_class(tid) ||
+    if (H5P_FILE_ACCESS != H5P_get_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a file access property list");
@@ -1460,7 +1501,7 @@ H5Pget_sec2 (hid_t tid)
     H5TRACE1("e","i",tid);
 
     /* Check arguments */
-    if (H5P_FILE_ACCESS != H5Pget_class (tid) ||
+    if (H5P_FILE_ACCESS != H5P_get_class (tid) ||
 	NULL == (tmpl = H5I_object (tid))) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
 		       "not a file access property list");
@@ -1505,7 +1546,7 @@ H5Pset_core (hid_t tid, size_t increment)
     H5TRACE2("e","iz",tid,increment);
 
     /* Check arguments */
-    if (H5P_FILE_ACCESS != H5Pget_class(tid) ||
+    if (H5P_FILE_ACCESS != H5P_get_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a file access property list");
@@ -1550,10 +1591,10 @@ H5Pget_core (hid_t tid, size_t *increment/*out*/)
     H5F_access_t	*tmpl = NULL;
 
     FUNC_ENTER (H5Pget_core, FAIL);
-    H5TRACE1("e","i",tid);
+    H5TRACE2("e","ix",tid,increment);
 
     /* Check arguments */
-    if (H5P_FILE_ACCESS != H5Pget_class (tid) ||
+    if (H5P_FILE_ACCESS != H5P_get_class (tid) ||
 	NULL == (tmpl = H5I_object (tid))) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
 		       "not a file access property list");
@@ -1601,19 +1642,19 @@ H5Pset_split (hid_t tid, const char *meta_ext, hid_t meta_tid,
     H5TRACE5("e","isisi",tid,meta_ext,meta_tid,raw_ext,raw_tid);
 
     /* Check arguments */
-    if (H5P_FILE_ACCESS != H5Pget_class(tid) ||
+    if (H5P_FILE_ACCESS != H5P_get_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a file access property list");
     }
     if (H5P_DEFAULT!=meta_tid &&
-	(H5P_FILE_ACCESS != H5Pget_class(meta_tid) ||
+	(H5P_FILE_ACCESS != H5P_get_class(meta_tid) ||
 	 NULL == (meta_tmpl = H5I_object(meta_tid)))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a file access property list");
     }
     if (H5P_DEFAULT!=raw_tid &&
-	(H5P_FILE_ACCESS != H5Pget_class(raw_tid) ||
+	(H5P_FILE_ACCESS != H5P_get_class(raw_tid) ||
 	 NULL == (raw_tmpl = H5I_object(raw_tid)))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a file access property list");
@@ -1666,10 +1707,11 @@ H5Pget_split (hid_t tid, size_t meta_ext_size, char *meta_ext/*out*/,
     H5F_access_t	*tmpl = NULL;
 
     FUNC_ENTER (H5Pget_split, FAIL);
-    H5TRACE3("e","izz",tid,meta_ext_size,raw_ext_size);
+    H5TRACE7("e","izxxzxx",tid,meta_ext_size,meta_ext,meta_properties,
+             raw_ext_size,raw_ext,raw_properties);
 
     /* Check arguments */
-    if (H5P_FILE_ACCESS != H5Pget_class (tid) ||
+    if (H5P_FILE_ACCESS != H5P_get_class (tid) ||
 	NULL == (tmpl = H5I_object (tid))) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
 		       "not a file access property list");
@@ -1748,7 +1790,7 @@ H5Pset_family (hid_t tid, hsize_t memb_size, hid_t memb_tid)
     H5TRACE3("e","ihi",tid,memb_size,memb_tid);
 
     /* Check arguments */
-    if (H5P_FILE_ACCESS != H5Pget_class(tid) ||
+    if (H5P_FILE_ACCESS != H5P_get_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a file access property list");
@@ -1758,7 +1800,7 @@ H5Pset_family (hid_t tid, hsize_t memb_size, hid_t memb_tid)
 		       "family member size is too small");
     }
     if (H5P_DEFAULT!=memb_tid &&
-	(H5P_FILE_ACCESS != H5Pget_class(memb_tid) ||
+	(H5P_FILE_ACCESS != H5P_get_class(memb_tid) ||
 	 NULL == (tmpl = H5I_object(memb_tid)))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a file access property list");
@@ -1802,10 +1844,10 @@ H5Pget_family (hid_t tid, hsize_t *memb_size/*out*/, hid_t *memb_tid/*out*/)
     H5F_access_t	*tmpl = NULL;
 
     FUNC_ENTER (H5Pget_family, FAIL);
-    H5TRACE1("e","i",tid);
+    H5TRACE3("e","ixx",tid,memb_size,memb_tid);
 
     /* Check arguments */
-    if (H5P_FILE_ACCESS != H5Pget_class (tid) ||
+    if (H5P_FILE_ACCESS != H5P_get_class (tid) ||
 	NULL == (tmpl = H5I_object (tid))) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
 		       "not a file access property list");
@@ -1864,7 +1906,7 @@ H5Pset_cache (hid_t tid, int mdc_nelmts, size_t rdcc_nbytes,
     H5TRACE4("e","iIszd",tid,mdc_nelmts,rdcc_nbytes,rdcc_w0);
 
     /* Check arguments */
-    if (H5P_FILE_ACCESS!=H5Pget_class (tid) ||
+    if (H5P_FILE_ACCESS!=H5P_get_class (tid) ||
 	NULL==(fapl=H5I_object (tid))) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
 		       "not a file access property list");
@@ -1918,7 +1960,7 @@ H5Pget_cache (hid_t tid, int *mdc_nelmts, size_t *rdcc_nbytes,
     H5TRACE4("e","i*Is*z*d",tid,mdc_nelmts,rdcc_nbytes,rdcc_w0);
 
     /* Check arguments */
-    if (H5P_FILE_ACCESS!=H5Pget_class (tid) ||
+    if (H5P_FILE_ACCESS!=H5P_get_class (tid) ||
 	NULL==(fapl=H5I_object (tid))) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
 		       "not a file access property list");
@@ -1971,7 +2013,7 @@ H5Pset_buffer (hid_t plist_id, size_t size, void *tconv, void *bkg)
     H5TRACE4("e","izxx",plist_id,size,tconv,bkg);
 
     /* Check arguments */
-    if (H5P_DATASET_XFER != H5Pget_class (plist_id) ||
+    if (H5P_DATASET_XFER != H5P_get_class (plist_id) ||
 	NULL == (plist = H5I_object (plist_id))) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
 		       "not a dataset transfer property list");
@@ -2012,10 +2054,10 @@ H5Pget_buffer (hid_t plist_id, void **tconv/*out*/, void **bkg/*out*/)
     H5D_xfer_t		*plist = NULL;
     
     FUNC_ENTER (H5Pget_buffer, 0);
-    H5TRACE1("z","i",plist_id);
+    H5TRACE3("z","ixx",plist_id,tconv,bkg);
 
     /* Check arguments */
-    if (H5P_DATASET_XFER != H5Pget_class (plist_id) ||
+    if (H5P_DATASET_XFER != H5P_get_class (plist_id) ||
 	NULL == (plist = H5I_object (plist_id))) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, 0,
 		       "not a dataset transfer property list");
@@ -2058,7 +2100,7 @@ H5Pset_preserve (hid_t plist_id, hbool_t status)
     H5TRACE2("e","ib",plist_id,status);
 
     /* Check arguments */
-    if (H5P_DATASET_XFER != H5Pget_class (plist_id) ||
+    if (H5P_DATASET_XFER != H5P_get_class (plist_id) ||
 	NULL == (plist = H5I_object (plist_id))) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
 		       "not a dataset transfer property list");
@@ -2096,7 +2138,7 @@ H5Pget_preserve (hid_t plist_id)
     H5TRACE1("Is","i",plist_id);
 
     /* Check arguments */
-    if (H5P_DATASET_XFER != H5Pget_class (plist_id) ||
+    if (H5P_DATASET_XFER != H5P_get_class (plist_id) ||
 	NULL == (plist = H5I_object (plist_id))) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
 		       "not a dataset transfer property list");
@@ -2141,7 +2183,7 @@ H5Pset_compression (hid_t plist_id, H5Z_method_t method, unsigned int flags,
     H5TRACE5("e","iZmIuzx",plist_id,method,flags,cd_size,client_data);
 
     /* Check arguments */
-    if (H5P_DATASET_CREATE!=H5Pget_class (plist_id) ||
+    if (H5P_DATASET_CREATE!=H5P_get_class (plist_id) ||
 	NULL==(plist=H5I_object (plist_id))) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
 		       "not a dataset creation property list");
@@ -2190,14 +2232,15 @@ H5Pset_compression (hid_t plist_id, H5Z_method_t method, unsigned int flags,
  */
 H5Z_method_t
 H5Pget_compression (hid_t plist_id, unsigned int *flags/*out*/,
-		    size_t *cd_size/*in,out*/, void *client_data/*out*/)
+		    size_t *cd_size/*in_out*/, void *client_data/*out*/)
 {
     H5D_create_t	*plist = NULL;
     
     FUNC_ENTER (H5Pget_compression, FAIL);
+    H5TRACE4("Zm","ix*zx",plist_id,flags,cd_size,client_data);
     
     /* Check arguments */
-    if (H5P_DATASET_CREATE!=H5Pget_class (plist_id) ||
+    if (H5P_DATASET_CREATE!=H5P_get_class (plist_id) ||
 	NULL==(plist=H5I_object (plist_id))) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
 		       "not a dataset creation property list");
@@ -2247,7 +2290,7 @@ H5Pset_deflate (hid_t plist_id, int level)
     H5TRACE2("e","iIs",plist_id,level);
 
     /* Check arguments */
-    if (H5P_DATASET_CREATE!=H5Pget_class (plist_id) ||
+    if (H5P_DATASET_CREATE!=H5P_get_class (plist_id) ||
 	NULL==(plist=H5I_object (plist_id))) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
 		       "not a dataset creation property list");
@@ -2295,7 +2338,7 @@ H5Pget_deflate (hid_t plist_id)
     H5TRACE1("Is","i",plist_id);
     
     /* Check arguments */
-    if (H5P_DATASET_CREATE!=H5Pget_class (plist_id) ||
+    if (H5P_DATASET_CREATE!=H5P_get_class (plist_id) ||
 	NULL==(plist=H5I_object (plist_id))) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
 		       "not a dataset creation property list");
@@ -2371,7 +2414,7 @@ H5Pset_mpi (hid_t tid, MPI_Comm comm, MPI_Info info)
     H5TRACE3("e","iMcMi",tid,comm,info);
 
     /* Check arguments */
-    if (H5P_FILE_ACCESS != H5Pget_class(tid) ||
+    if (H5P_FILE_ACCESS != H5P_get_class(tid) ||
 	NULL == (tmpl = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a file access property list");
@@ -2426,7 +2469,7 @@ H5Pget_mpi (hid_t tid, MPI_Comm *comm, MPI_Info *info)
     H5TRACE3("e","i*Mc*Mi",tid,comm,info);
 
     /* Check arguments */
-    if (H5P_FILE_ACCESS != H5Pget_class (tid) ||
+    if (H5P_FILE_ACCESS != H5P_get_class (tid) ||
 	NULL == (tmpl = H5I_object (tid))) {
 	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
 		       "not a file access property list");
@@ -2488,7 +2531,7 @@ H5Pset_xfer (hid_t tid, H5D_transfer_t data_xfer_mode)
     H5TRACE2("e","iDt",tid,data_xfer_mode);
 
     /* Check arguments */
-    if (H5P_DATASET_XFER != H5Pget_class(tid) ||
+    if (H5P_DATASET_XFER != H5P_get_class(tid) ||
 	NULL == (plist = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a dataset transfer property list");
@@ -2538,7 +2581,7 @@ H5Pget_xfer (hid_t tid, H5D_transfer_t *data_xfer_mode)
     H5TRACE2("e","i*Dt",tid,data_xfer_mode);
 
     /* Check arguments */
-    if (H5P_DATASET_XFER != H5Pget_class(tid) ||
+    if (H5P_DATASET_XFER != H5P_get_class(tid) ||
 	NULL == (plist = H5I_object(tid))) {
 	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
 		      "not a dataset transfer property list");
@@ -2588,7 +2631,7 @@ H5Pcopy (hid_t tid)
 
     /* Check args */
     if (NULL == (tmpl = H5I_object(tid)) ||
-	(type = H5Pget_class(tid)) < 0 ||
+	(type = H5P_get_class(tid)) < 0 ||
 	(group = H5I_group(tid)) < 0) {
 	HRETURN_ERROR(H5E_ATOM, H5E_BADATOM, FAIL,
 		      "unable to unatomize property list");
diff --git a/src/H5Pprivate.h b/src/H5Pprivate.h
index d1b877b..36c8652 100644
--- a/src/H5Pprivate.h
+++ b/src/H5Pprivate.h
@@ -25,5 +25,6 @@
 hid_t H5P_create (H5P_class_t type, void *tmpl);
 void *H5P_copy (H5P_class_t type, const void *src);
 herr_t H5P_close (H5P_class_t type, void *tmpl);
+H5P_class_t H5P_get_class(hid_t tid);
 
 #endif
diff --git a/src/H5S.c b/src/H5S.c
index 3899ee8..54bb777 100644
--- a/src/H5S.c
+++ b/src/H5S.c
@@ -694,7 +694,7 @@ H5Sget_dims (hid_t space_id, hsize_t dims[]/*out*/, hsize_t maxdims[]/*out*/)
     intn		   ret_value = 0;
 
     FUNC_ENTER(H5Sget_dims, FAIL);
-    H5TRACE1("Is","i",space_id);
+    H5TRACE3("Is","ixx",space_id,dims,maxdims);
 
     /* Check args */
     if (H5_DATASPACE != H5I_group(space_id) || NULL == (ds = H5I_object(space_id))) {
diff --git a/src/H5T.c b/src/H5T.c
index 8026516..d9280eb 100644
--- a/src/H5T.c
+++ b/src/H5T.c
@@ -99,6 +99,9 @@ static intn H5T_nsoft_g = 0;			/*num soft funcs defined */
 static intn H5T_asoft_g = 0;			/*num slots allocated	*/
 static H5T_soft_t *H5T_soft_g = NULL;		/*master soft list	*/
 
+/* The overflow handler */
+H5T_overflow_t H5T_overflow_g = NULL;
+
 /*--------------------------------------------------------------------------
 NAME
    H5T_init_interface -- Initialize interface-specific information
@@ -1201,11 +1204,12 @@ H5Tlock (hid_t type_id)
  *-------------------------------------------------------------------------
  */
 H5T_class_t
-H5Tget_class(hid_t type_id)
+H5Tget_class (hid_t type_id)
 {
     H5T_t	*dt = NULL;
 
     FUNC_ENTER(H5Tget_class, H5T_NO_CLASS);
+    H5TRACE1("Tt","i",type_id);
 
     /* Check args */
     if (H5_DATATYPE != H5I_group(type_id) ||
@@ -1384,12 +1388,13 @@ H5Tset_size (hid_t type_id, size_t size)
  *-------------------------------------------------------------------------
  */
 H5T_order_t
-H5Tget_order(hid_t type_id)
+H5Tget_order (hid_t type_id)
 {
     H5T_t		*dt = NULL;
     H5T_order_t		order;
 
     FUNC_ENTER(H5Tget_order, H5T_ORDER_ERROR);
+    H5TRACE1("To","i",type_id);
 
     /* Check args */
     if (H5_DATATYPE != H5I_group(type_id) ||
@@ -1751,7 +1756,7 @@ H5Tget_pad (hid_t type_id, H5T_pad_t *lsb/*out*/, H5T_pad_t *msb/*out*/)
     H5T_t	*dt = NULL;
 
     FUNC_ENTER(H5Tget_pad, FAIL);
-    H5TRACE1("e","i",type_id);
+    H5TRACE3("e","ixx",type_id,lsb,msb);
 
     /* Check args */
     if (H5_DATATYPE != H5I_group(type_id) ||
@@ -1830,12 +1835,13 @@ H5Tset_pad (hid_t type_id, H5T_pad_t lsb, H5T_pad_t msb)
  *-------------------------------------------------------------------------
  */
 H5T_sign_t
-H5Tget_sign(hid_t type_id)
+H5Tget_sign (hid_t type_id)
 {
     H5T_t		*dt = NULL;
     H5T_sign_t		sign;
 
     FUNC_ENTER(H5Tget_sign, H5T_SGN_ERROR);
+    H5TRACE1("Ts","i",type_id);
 
     /* Check args */
     if (H5_DATATYPE != H5I_group(type_id) ||
@@ -1925,7 +1931,7 @@ H5Tget_fields (hid_t type_id, size_t *spos/*out*/,
     H5T_t	*dt = NULL;
 
     FUNC_ENTER(H5Tget_fields, FAIL);
-    H5TRACE1("e","i",type_id);
+    H5TRACE6("e","ixxxxx",type_id,spos,epos,esize,mpos,msize);
 
     /* Check args */
     if (H5_DATATYPE != H5I_group(type_id) ||
@@ -2126,12 +2132,13 @@ H5Tset_ebias (hid_t type_id, size_t ebias)
  *-------------------------------------------------------------------------
  */
 H5T_norm_t
-H5Tget_norm(hid_t type_id)
+H5Tget_norm (hid_t type_id)
 {
     H5T_t	*dt = NULL;
     H5T_norm_t	norm;
 
     FUNC_ENTER(H5Tget_norm, H5T_NORM_ERROR);
+    H5TRACE1("Tn","i",type_id);
 
     /* Check args */
     if (H5_DATATYPE != H5I_group(type_id) ||
@@ -2213,12 +2220,13 @@ H5Tset_norm (hid_t type_id, H5T_norm_t norm)
  *-------------------------------------------------------------------------
  */
 H5T_pad_t
-H5Tget_inpad(hid_t type_id)
+H5Tget_inpad (hid_t type_id)
 {
     H5T_t	*dt = NULL;
     H5T_pad_t	pad;
 
     FUNC_ENTER(H5Tget_inpad, H5T_PAD_ERROR);
+    H5TRACE1("Tp","i",type_id);
 
     /* Check args */
     if (H5_DATATYPE != H5I_group(type_id) ||
@@ -2302,12 +2310,13 @@ H5Tset_inpad (hid_t type_id, H5T_pad_t pad)
  *-------------------------------------------------------------------------
  */
 H5T_cset_t
-H5Tget_cset(hid_t type_id)
+H5Tget_cset (hid_t type_id)
 {
     H5T_t	*dt = NULL;
     H5T_cset_t	cset;
 
     FUNC_ENTER(H5Tget_cset, H5T_CSET_ERROR);
+    H5TRACE1("Tc","i",type_id);
 
     /* Check args */
     if (H5_DATATYPE != H5I_group(type_id) ||
@@ -2390,12 +2399,13 @@ H5Tset_cset (hid_t type_id, H5T_cset_t cset)
  *-------------------------------------------------------------------------
  */
 H5T_str_t
-H5Tget_strpad(hid_t type_id)
+H5Tget_strpad (hid_t type_id)
 {
     H5T_t	*dt = NULL;
     H5T_str_t	strpad;
 
     FUNC_ENTER(H5Tget_strpad, H5T_STR_ERROR);
+    H5TRACE1("Tz","i",type_id);
 
     /* Check args */
     if (H5_DATATYPE != H5I_group(type_id) ||
@@ -2614,7 +2624,7 @@ H5Tget_member_dims (hid_t type_id, int membno,
     intn	ndims, i;
 
     FUNC_ENTER(H5Tget_member_dims, FAIL);
-    H5TRACE2("Is","iIs",type_id,membno);
+    H5TRACE4("Is","iIsxx",type_id,membno,dims,perm);
 
     /* Check args */
     if (H5_DATATYPE != H5I_group(type_id) ||
@@ -2831,7 +2841,8 @@ H5Tpack (hid_t type_id)
  *-------------------------------------------------------------------------
  */
 herr_t
-H5Tregister_hard (const char *name, hid_t src_id, hid_t dst_id, H5T_conv_t func)
+H5Tregister_hard (const char *name, hid_t src_id, hid_t dst_id,
+		  H5T_conv_t func)
 {
     H5T_t	*src = NULL;
     H5T_t	*dst = NULL;
@@ -3139,12 +3150,13 @@ H5Tunregister (H5T_conv_t func)
  *-------------------------------------------------------------------------
  */
 H5T_conv_t
-H5Tfind(hid_t src_id, hid_t dst_id, H5T_cdata_t **pcdata)
+H5Tfind (hid_t src_id, hid_t dst_id, H5T_cdata_t **pcdata)
 {
     H5T_conv_t	ret_value = NULL;
     H5T_t	*src = NULL, *dst = NULL;
 
     FUNC_ENTER(H5Tfind, NULL);
+    H5TRACE3("x","iix",src_id,dst_id,pcdata);
 
     /* Check args */
     if (H5_DATATYPE != H5I_group(src_id) ||
@@ -3228,6 +3240,71 @@ H5Tconvert (hid_t src_id, hid_t dst_id, size_t nelmts, void *buf,
     FUNC_LEAVE (SUCCEED);
 }
 
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Tget_overflow
+ *
+ * Purpose:	Returns a pointer to the current global overflow function.
+ *		This is an application-defined function that is called
+ *		whenever a data type conversion causes an overflow.
+ *
+ * Return:	Success:	Ptr to an application-defined function.
+ *
+ *		Failure:	NULL (this can happen if no overflow handling
+ *				function is registered).
+ *
+ * Programmer:	Robb Matzke
+ *              Tuesday, July  7, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+H5T_overflow_t
+H5Tget_overflow (void)
+{
+    FUNC_ENTER(H5Tget_overflow, NULL);
+    H5TRACE0("x","");
+
+    if (NULL==H5T_overflow_g) {
+	HRETURN_ERROR(H5E_DATATYPE, H5E_UNINITIALIZED, NULL,
+		      "no overflow handling function is registered");
+    }
+
+    FUNC_LEAVE(H5T_overflow_g);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Tset_overflow
+ *
+ * Purpose:	Sets the overflow handler to be the specified function.  FUNC
+ *		will be called for all data type conversions that result in
+ *		an overflow.  See the definition of `H5T_overflow_t' for
+ *		documentation of arguments and return values.  The NULL
+ *		pointer may be passed to remove the overflow handler.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Tuesday, July  7, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Tset_overflow (H5T_overflow_t func)
+{
+    FUNC_ENTER(H5Tset_overflow, FAIL);
+    H5TRACE1("e","x",func);
+    H5T_overflow_g = func;
+    FUNC_LEAVE(SUCCEED);
+}
+
+
 /*-------------------------------------------------------------------------
  * API functions are above; library-private functions are below...
  *------------------------------------------------------------------------- 
diff --git a/src/H5Tconv.c b/src/H5Tconv.c
index 930b330..211caf7 100644
--- a/src/H5Tconv.c
+++ b/src/H5Tconv.c
@@ -14,6 +14,7 @@
 #include <H5MMprivate.h>
 #include <H5Tpkg.h>
 #include <math.h>		/*for ceil()				     */
+#include <float.h>		/*for FLT_MAX and HUGE_VAL		     */
 
 /* Conversion data for H5T_conv_struct() */
 typedef struct H5T_conv_struct_t {
@@ -551,6 +552,9 @@ H5T_conv_struct(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t nelmts,
  *
  * Modifications:
  *
+ * 	Robb Matzke, 7 Jul 1998
+ *	Added overflow handling.
+ *
  *-------------------------------------------------------------------------
  */
 herr_t
@@ -701,8 +705,11 @@ H5T_conv_i_i (hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata,
 				 dst->u.atomic.prec-src->u.atomic.prec, FALSE);
 		} else if (first>=dst->u.atomic.prec) {
 		    /*overflow*/
-		    H5T_bit_set (d, dst->u.atomic.offset, dst->u.atomic.prec,
-				 TRUE);
+		    if (!H5T_overflow_g ||
+			(H5T_overflow_g)(src_id, dst_id, s, d)<0) {
+			H5T_bit_set (d, dst->u.atomic.offset,
+				     dst->u.atomic.prec, TRUE);
+		    }
 		} else {
 		    H5T_bit_copy (d, dst->u.atomic.offset,
 				  s, src->u.atomic.offset,
@@ -715,13 +722,16 @@ H5T_conv_i_i (hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata,
 		 * If the source is signed and the destination isn't then we
 		 * can have overflow if the source contains more bits than
 		 * the destination (destination is set to the maximum
-		 * possible value) or underflow if the source is negative
+		 * possible value) or overflow if the source is negative
 		 * (destination is set to zero).
 		 */
 		if (first+1 == src->u.atomic.prec) {
-		    /*underflow*/
-		    H5T_bit_set (d, dst->u.atomic.offset, dst->u.atomic.prec,
-				 FALSE);
+		    /*overflow*/
+		    if (!H5T_overflow_g ||
+			(H5T_overflow_g)(src_id, dst_id, s, d)<0) {
+			H5T_bit_set (d, dst->u.atomic.offset,
+				     dst->u.atomic.prec, FALSE);
+		    }
 		} else if (src->u.atomic.prec < dst->u.atomic.prec) {
 		    H5T_bit_copy (d, dst->u.atomic.offset,
 				  s, src->u.atomic.offset,
@@ -731,8 +741,11 @@ H5T_conv_i_i (hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata,
 				 FALSE);
 		} else if (first>=dst->u.atomic.prec) {
 		    /*overflow*/
-		    H5T_bit_set (d, dst->u.atomic.offset, dst->u.atomic.prec,
-				 TRUE);
+		    if (!H5T_overflow_g ||
+			(H5T_overflow_g)(src_id, dst_id, s, d)<0) {
+			H5T_bit_set (d, dst->u.atomic.offset,
+				     dst->u.atomic.prec, TRUE);
+		    }
 		} else {
 		    H5T_bit_copy (d, dst->u.atomic.offset,
 				  s, src->u.atomic.offset,
@@ -748,10 +761,13 @@ H5T_conv_i_i (hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata,
 		 */
 		if (first+1 >= dst->u.atomic.prec) {
 		    /*overflow*/
-		    H5T_bit_set (d, dst->u.atomic.offset,
-				 dst->u.atomic.prec-1, TRUE);
-		    H5T_bit_set (d, dst->u.atomic.offset+dst->u.atomic.prec-1,
-				 1, FALSE);
+		    if (!H5T_overflow_g ||
+			(H5T_overflow_g)(src_id, dst_id, s, d)<0) {
+			H5T_bit_set (d, dst->u.atomic.offset,
+				     dst->u.atomic.prec-1, TRUE);
+			H5T_bit_set (d, (dst->u.atomic.offset +
+					 dst->u.atomic.prec-1), 1, FALSE);
+		    }
 		} else if (src->u.atomic.prec<dst->u.atomic.prec) {
 		    H5T_bit_copy (d, dst->u.atomic.offset,
 				  s, src->u.atomic.offset,
@@ -767,7 +783,7 @@ H5T_conv_i_i (hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata,
 	    } else if (first+1 == src->u.atomic.prec) {
 		/*
 		 * Both the source and the destination are signed and the
-		 * source value is negative.  We could experience underflow
+		 * source value is negative.  We could experience overflow
 		 * if the destination isn't wide enough in which case the
 		 * destination is set to a negative number with the largest
 		 * possible magnitude.
@@ -778,11 +794,14 @@ H5T_conv_i_i (hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata,
 		size_t fz = (size_t)sfz;
 		
 		if (sfz>=0 && fz+1>=dst->u.atomic.prec) {
-		    /*underflow*/
-		    H5T_bit_set (d, dst->u.atomic.offset, dst->u.atomic.prec-1,
-				 FALSE);
-		    H5T_bit_set (d, dst->u.atomic.offset+dst->u.atomic.prec-1,
-				 1, TRUE);
+		    /*overflow*/
+		    if (!H5T_overflow_g ||
+			(H5T_overflow_g)(src_id, dst_id, s, d)<0) {
+			H5T_bit_set (d, dst->u.atomic.offset,
+				     dst->u.atomic.prec-1, FALSE);
+			H5T_bit_set (d, (dst->u.atomic.offset +
+					 dst->u.atomic.prec-1), 1, TRUE);
+		    }
 		} else if (src->u.atomic.prec<dst->u.atomic.prec) {
 		    H5T_bit_copy (d, dst->u.atomic.offset,
 				  s, src->u.atomic.offset,
@@ -804,10 +823,13 @@ H5T_conv_i_i (hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata,
 		 */
 		if (first+1>=dst->u.atomic.prec) {
 		    /*overflow*/
-		    H5T_bit_set (d, dst->u.atomic.offset, dst->u.atomic.prec-1,
-				 TRUE);
-		    H5T_bit_set (d, dst->u.atomic.offset+dst->u.atomic.prec-1,
-				 1, FALSE);
+		    if (!H5T_overflow_g ||
+			(H5T_overflow_g)(src_id, dst_id, s, d)<0) {
+			H5T_bit_set (d, dst->u.atomic.offset,
+				     dst->u.atomic.prec-1, TRUE);
+			H5T_bit_set (d, (dst->u.atomic.offset +
+					 dst->u.atomic.prec-1), 1, FALSE);
+		    }
 		} else if (src->u.atomic.prec<dst->u.atomic.prec) {
 		    H5T_bit_copy (d, dst->u.atomic.offset,
 				  s, src->u.atomic.offset,
@@ -888,6 +910,9 @@ H5T_conv_i_i (hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata,
  *
  * Modifications:
  *
+ * 	Robb Matzke, 7 Jul 1998
+ *	Added overflow handling.
+ *
  *-------------------------------------------------------------------------
  */
 herr_t
@@ -1143,12 +1168,30 @@ H5T_conv_f_f (hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata,
 		/*
 		 * The exponent is too large to fit in the available region
 		 * or it results in the maximum possible value.  Use positive
-		 * or negative infinity instead.
+		 * or negative infinity instead unless the application
+		 * specifies something else.  Before calling the overflow
+		 * handler make sure the source buffer we hand it is in the
+		 * original byte order.
 		 */
+		if (H5T_overflow_g) {
+		    uint8 over_src[256];
+		    assert(src_p->size<=sizeof over_src);
+		    if (H5T_ORDER_BE==src.order) {
+			for (i=0; i<src_p->size; i++) {
+			    over_src[src_p->size-(i+1)] = s[i];
+			}
+		    } else {
+			for (i=0; i<src_p->size; i++) {
+			    over_src[i] = s[i];
+			}
+		    }
+		    if ((H5T_overflow_g)(src_id, dst_id, over_src, d)>=0) {
+			goto next;
+		    }
+		}
 		expo = expo_max;
 		H5T_bit_set(d, dst.u.f.mpos, dst.u.f.msize, FALSE);
 		msize = 0;
-		
 	    }
 
 	    /*
@@ -1239,6 +1282,7 @@ H5T_conv_f_f (hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata,
 	     * If we had used a temporary buffer for the destination then we
 	     * should copy the value to the true destination buffer.
 	     */
+	next:
 	    if (d==dbuf) HDmemcpy (dp, d, dst_p->size);
 	    sp += direction * src_p->size;
 	    dp += direction * dst_p->size;
@@ -1324,12 +1368,14 @@ H5T_conv_float_double (hid_t __unused__ src_id, hid_t __unused__ dst_id,
  *
  * Modifications:
  *
+ * 	Robb Matzke, 7 Jul 1998
+ *	Added overflow handling.
+ *
  *-------------------------------------------------------------------------
  */
 herr_t
-H5T_conv_double_float (hid_t __unused__ src_id, hid_t __unused__ dst_id,
-		       H5T_cdata_t *cdata, size_t nelmts, void *buf,
-		       void __unused__ *bkg)
+H5T_conv_double_float (hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata,
+		       size_t nelmts, void *buf, void __unused__ *bkg)
 {
     size_t	elmtno;			/*element number		*/
     double	*s;			/*source buffer			*/
@@ -1349,8 +1395,20 @@ H5T_conv_double_float (hid_t __unused__ src_id, hid_t __unused__ dst_id,
 	s = (double*)buf;
 	d = (float*)buf;
 
-	for (elmtno=0; elmtno<nelmts; elmtno++) {
-	    *d++ = *s++;
+	for (elmtno=0; elmtno<nelmts; elmtno++, d++, s++) {
+	    if (*s > FLT_MAX) {
+		if (!H5T_overflow_g ||
+		    (H5T_overflow_g)(src_id, dst_id, s, d)<0) {
+		    *d = HUGE_VAL;
+		}
+	    } else if (*s < -FLT_MAX) {
+		if (!H5T_overflow_g ||
+		    (H5T_overflow_g)(src_id, dst_id, s, d)<0) {
+		    *d = -HUGE_VAL;
+		}
+	    } else {
+		*d = *s;
+	    }
 	}
 	break;
 	    
diff --git a/src/H5Tpkg.h b/src/H5Tpkg.h
index a411916..e53a5e0 100644
--- a/src/H5Tpkg.h
+++ b/src/H5Tpkg.h
@@ -116,6 +116,9 @@ typedef enum H5T_sdir_t {
     H5T_BIT_MSB				/*search msb toward lsb		     */
 } H5T_sdir_t;
 
+/* The overflow handler */
+extern H5T_overflow_t H5T_overflow_g;
+
 /* Function prototypes for H5T package scope */
 H5T_path_t *H5T_path_find (const char *name, const H5T_t *src,
 			   const H5T_t *dst, hbool_t create, H5T_conv_t func);
diff --git a/src/H5Tpublic.h b/src/H5Tpublic.h
index 56ad7c3..89491fc 100644
--- a/src/H5Tpublic.h
+++ b/src/H5Tpublic.h
@@ -118,6 +118,19 @@ typedef struct H5T_cdata_t {
 typedef herr_t (*H5T_conv_t) (hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata,
 			      size_t nelmts, void *buf, void *bkg);
 
+/*
+ * If an error occurs during a data type conversion then the function
+ * registered with H5Tset_overflow() is called.  It's arguments are the
+ * source and destination data types, a buffer which has the source value,
+ * and a buffer to receive an optional result for the overflow conversion.
+ * If the overflow handler chooses a value for the result it should return
+ * non-negative; otherwise the hdf5 library will choose an appropriate
+ * result.
+ */
+typedef herr_t (*H5T_overflow_t)(hid_t src_id, hid_t dst_id,
+				 void *src_buf, void *dst_buf);
+
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -379,6 +392,8 @@ herr_t H5Tunregister (H5T_conv_t func);
 H5T_conv_t H5Tfind (hid_t src_id, hid_t dst_id, H5T_cdata_t **pcdata);
 herr_t H5Tconvert (hid_t src_id, hid_t dst_id, size_t nelmts, void *buf,
 		   void *background);
+H5T_overflow_t H5Tget_overflow(void);
+herr_t H5Tset_overflow(H5T_overflow_t func);
 
 #ifdef __cplusplus
 }
diff --git a/src/H5private.h b/src/H5private.h
index 82f0add..2dac272 100644
--- a/src/H5private.h
+++ b/src/H5private.h
@@ -481,40 +481,45 @@ extern char *strdup(const char *s);
  *------------------------------------------------------------------------- 
  */
 #ifdef H5_DEBUG_API
-#define H5TRACE_DECL			  const char *RTYPE=NULL
-#define H5TRACE0(R,T)			  RTYPE=R;			      \
-                                          H5_trace(0,FUNC,T)
-#define H5TRACE1(R,T,A0)		  RTYPE=R;			      \
-                                          H5_trace(0,FUNC,T,#A0,A0)
-#define H5TRACE2(R,T,A0,A1)		  RTYPE=R;			      \
-                                          H5_trace(0,FUNC,T,#A0,A0,#A1,A1)
-#define H5TRACE3(R,T,A0,A1,A2)	  	  RTYPE=R;			      \
-                                          H5_trace(0,FUNC,T,#A0,A0,#A1,A1,    \
-                                                   #A2,A2)
-#define H5TRACE4(R,T,A0,A1,A2,A3)	  RTYPE=R;			      \
-                                          H5_trace(0,FUNC,T,#A0,A0,#A1,A1,    \
-                                                   #A2,A2,#A3,A3)
-#define H5TRACE5(R,T,A0,A1,A2,A3,A4)	  RTYPE=R;			      \
-                                          H5_trace(0,FUNC,T,#A0,A0,#A1,A1,    \
-                                                   #A2,A2,#A3,A3,#A4,A4)
-#define H5TRACE6(R,T,A0,A1,A2,A3,A4,A5)	  RTYPE=R;			      \
-                                          H5_trace(0,FUNC,T,#A0,A0,#A1,A1,    \
-                                                   #A2,A2,#A3,A3,#A4,A4,      \
-                                                   #A5,A5)
-#define H5TRACE_RETURN(V)		  if (RTYPE) {			      \
-                                             H5_trace(1,NULL,RTYPE,NULL,V);   \
-                                             RTYPE=NULL;		      \
-                                          }
+#define H5TRACE_DECL			   const char *RTYPE=NULL
+#define H5TRACE0(R,T)			   RTYPE=R;			      \
+                                           H5_trace(0,FUNC,T)
+#define H5TRACE1(R,T,A0)		   RTYPE=R;			      \
+                                           H5_trace(0,FUNC,T,#A0,A0)
+#define H5TRACE2(R,T,A0,A1)		   RTYPE=R;			      \
+                                           H5_trace(0,FUNC,T,#A0,A0,#A1,A1)
+#define H5TRACE3(R,T,A0,A1,A2)	  	   RTYPE=R;			      \
+                                           H5_trace(0,FUNC,T,#A0,A0,#A1,A1,   \
+                                                    #A2,A2)
+#define H5TRACE4(R,T,A0,A1,A2,A3)	   RTYPE=R;			      \
+                                           H5_trace(0,FUNC,T,#A0,A0,#A1,A1,   \
+                                                    #A2,A2,#A3,A3)
+#define H5TRACE5(R,T,A0,A1,A2,A3,A4)	   RTYPE=R;			      \
+                                           H5_trace(0,FUNC,T,#A0,A0,#A1,A1,   \
+                                                    #A2,A2,#A3,A3,#A4,A4)
+#define H5TRACE6(R,T,A0,A1,A2,A3,A4,A5)	   RTYPE=R;			      \
+                                           H5_trace(0,FUNC,T,#A0,A0,#A1,A1,   \
+                                                    #A2,A2,#A3,A3,#A4,A4,     \
+                                                    #A5,A5)
+#define H5TRACE7(R,T,A0,A1,A2,A3,A4,A5,A6) RTYPE=R;			      \
+                                           H5_trace(0,FUNC,T,#A0,A0,#A1,A1,   \
+                                                    #A2,A2,#A3,A3,#A4,A4,     \
+                                                    #A5,A5,#A6,A6)
+#define H5TRACE_RETURN(V)		   if (RTYPE) {			      \
+                                              H5_trace(1,NULL,RTYPE,NULL,V);  \
+                                              RTYPE=NULL;		      \
+                                           }
 #else
-#define H5TRACE_DECL			  /*void*/
-#define H5TRACE0(R,T)			  /*void*/
-#define H5TRACE1(R,T,A0)		  /*void*/
-#define H5TRACE2(R,T,A0,A1)		  /*void*/
-#define H5TRACE3(R,T,A0,A1,A2)		  /*void*/
-#define H5TRACE4(R,T,A0,A1,A2,A3)	  /*void*/
-#define H5TRACE5(R,T,A0,A1,A2,A3,A4)	  /*void*/
-#define H5TRACE6(R,T,A0,A1,A2,A3,A4,A5)	  /*void*/
-#define H5TRACE_RETURN(V)		  /*void*/
+#define H5TRACE_DECL			   /*void*/
+#define H5TRACE0(R,T)			   /*void*/
+#define H5TRACE1(R,T,A0)		   /*void*/
+#define H5TRACE2(R,T,A0,A1)		   /*void*/
+#define H5TRACE3(R,T,A0,A1,A2)		   /*void*/
+#define H5TRACE4(R,T,A0,A1,A2,A3)	   /*void*/
+#define H5TRACE5(R,T,A0,A1,A2,A3,A4)	   /*void*/
+#define H5TRACE6(R,T,A0,A1,A2,A3,A4,A5)	   /*void*/
+#define H5TRACE7(R,T,A0,A1,A2,A3,A4,A5,A6) /*void*/
+#define H5TRACE_RETURN(V)		   /*void*/
 #endif
 
 void H5_trace (hbool_t returning, const char *func, const char *type, ...);