diff --git a/src/h5core/h5_attribs.c b/src/h5core/h5_attribs.c
index 055d81a..caa8b93 100644
--- a/src/h5core/h5_attribs.c
+++ b/src/h5core/h5_attribs.c
@@ -81,7 +81,7 @@ h5_read_attrib (
 
 	if (mode != H5_ATTRIB_FILE) CHECK_TIMEGROUP( f );
 
-	hid_t id;
+	hid_t id = 0;
 	TRY (get_hdf5_obj_id(f, mode, &id));
 	TRY (h5priv_read_attrib (id, attrib_name, attrib_type, attrib_value));
 	H5_CORE_API_RETURN (H5_SUCCESS);
@@ -161,7 +161,7 @@ h5_write_attrib (
 	if (mode != H5_ATTRIB_FILE) CHECK_TIMEGROUP( f );
 	CHECK_WRITABLE_MODE( f );
 
-	hid_t id;
+	hid_t id = 0;
 	TRY (get_hdf5_obj_id(f, mode, &id));
 	TRY (h5priv_write_attrib (id, attrib_name, attrib_type,
 				  attrib_value, attrib_nelem));
@@ -245,7 +245,7 @@ h5_get_attrib_info (
 
 	if (mode != H5_ATTRIB_FILE) CHECK_TIMEGROUP( f );
 
-	hid_t id;
+	hid_t id = 0;
 	TRY (get_hdf5_obj_id(f, mode, &id));
 	TRY (h5priv_get_attrib_info (id, attrib_idx, attrib_name, len_attrib_name,
 				     attrib_type, attrib_nelem));
@@ -267,7 +267,7 @@ h5_get_num_attribs (
 	H5_CORE_API_ENTER2 (h5_ssize_t,
 			    "f=%p, mode=%d", f, mode);
 	if (mode != H5_ATTRIB_FILE) CHECK_TIMEGROUP( f );
-	hid_t id;
+	hid_t id = 0;
 	TRY (get_hdf5_obj_id(f, mode, &id));
 	H5_CORE_API_RETURN (hdf5_get_num_attribute (id));
 }
diff --git a/src/h5core/h5_core_private.h b/src/h5core/h5_core_private.h
index dece6d5..e500a32 100644
--- a/src/h5core/h5_core_private.h
+++ b/src/h5core/h5_core_private.h
@@ -81,6 +81,22 @@
 #define MALLOC_WRAPPER_LEAVE(value)	__FUNC_LEAVE(value)
 #define MALLOC_WRAPPER_RETURN(value)	__FUNC_RETURN(value, H5_DEBUG_MALLOC)
 
+#define MPI_WRAPPER_ENTER(type)	__FUNC_ENTER(type)
+#define MPI_WRAPPER_ENTER0(type)		\
+	__FUNC_ENTER0(type, H5_DEBUG_MPI)
+#define MPI_WRAPPER_ENTER1(type, fmt, a1)		\
+	__FUNC_ENTER1(type, fmt, a1, H5_DEBUG_MPI)
+#define MPI_WRAPPER_ENTER2(type, fmt, a1, a2)		\
+	__FUNC_ENTER2(type, fmt, a1, a2, H5_DEBUG_MPI)
+#define MPI_WRAPPER_ENTER3(type, fmt, a1, a2, a3)		\
+	__FUNC_ENTER3(type, fmt, a1, a2, a3, H5_DEBUG_MPI)
+#define MPI_WRAPPER_ENTER4(type, fmt, a1, a2, a3, a4)		\
+	__FUNC_ENTER4(type, fmt, a1, a2, a3, a4, H5_DEBUG_MPI)
+#define MPI_WRAPPER_ENTER5(type, fmt, a1, a2, a3, a4, a5)	\
+	__FUNC_ENTER5(type, fmt, a1, a2, a3, a4, a5, H5_DEBUG_MPI)
+#define MPI_WRAPPER_LEAVE(value)	__FUNC_LEAVE(value)
+#define MPI_WRAPPER_RETURN(value)	__FUNC_RETURN(value, H5_DEBUG_MPI)
+
 /* WARNING! Changing these values will alter the data model and introduce
  * file incompatibilities with previous versions. */
 #define H5_DATANAME_LEN		64
diff --git a/src/h5core/h5_mpi.c b/src/h5core/h5_mpi.c
index bbd96a8..94fef91 100644
--- a/src/h5core/h5_mpi.c
+++ b/src/h5core/h5_mpi.c
@@ -12,6 +12,9 @@ h5priv_mpi_recv(
 	const int tag,
 	const MPI_Comm comm
 	) {
+	MPI_WRAPPER_ENTER4 (h5_err_t,
+			   "buf=0x%p, count=%d, type=?, from=%d, tag=%d, comm=?",
+			   buf, count, from, tag);
 	int err = MPI_Recv(
 		buf,
 		count,
@@ -22,8 +25,8 @@ h5priv_mpi_recv(
 		MPI_STATUS_IGNORE
 		);
 	if (err != MPI_SUCCESS)
-		return h5_error (H5_ERR_MPI, "Cannot receive data");
-	return H5_SUCCESS;
+		MPI_WRAPPER_LEAVE (h5_error (H5_ERR_MPI, "Cannot receive data"));
+	MPI_WRAPPER_RETURN (H5_SUCCESS);
 }
 
 h5_err_t
@@ -35,6 +38,9 @@ h5priv_mpi_send(
 	const int tag,
 	const MPI_Comm comm
 	) {
+	MPI_WRAPPER_ENTER4 (h5_err_t,
+			   "buf=0x%p, count=%d, type=?, to=%d, tag=%d, comm=?",
+			   buf, count, to, tag);
 	int err = MPI_Send(
 		buf,
 		count,
@@ -44,8 +50,8 @@ h5priv_mpi_send(
 		comm
 		);
 	if (err != MPI_SUCCESS)
-		return h5_error (H5_ERR_MPI, "Cannot send data");
-	return H5_SUCCESS;
+		MPI_WRAPPER_LEAVE (h5_error (H5_ERR_MPI, "Cannot send data"));
+	MPI_WRAPPER_RETURN (H5_SUCCESS);
 }
 
 h5_err_t
@@ -56,6 +62,9 @@ h5priv_mpi_bcast (
 	const int root,
 	const MPI_Comm comm
 	) {
+	MPI_WRAPPER_ENTER3 (h5_err_t,
+			   "buf=0x%p, count=%d, type=?, root=%d, comm=?",
+			   buf, count, root);
 	int err = MPI_Bcast(
 		buf,
 		count,
@@ -64,8 +73,8 @@ h5priv_mpi_bcast (
 		comm
 		);
 	if (err != MPI_SUCCESS)
-		return h5_error (H5_ERR_MPI, "Cannot perform broadcast");
-	return H5_SUCCESS;
+		MPI_WRAPPER_LEAVE (h5_error (H5_ERR_MPI, "Cannot perform broadcast"));
+	MPI_WRAPPER_RETURN (H5_SUCCESS);
 }
 
 
@@ -78,6 +87,9 @@ h5priv_mpi_sum (
 	const MPI_Datatype type,
 	const MPI_Comm comm
 	) {
+	MPI_WRAPPER_ENTER3 (h5_err_t,
+			   "sendbuf=0x%p, recvbuf=0x%p, count=%d, type=?, comm=?",
+			    sendbuf, recvbuf, count);
 	int err = MPI_Allreduce(
 		sendbuf,
 		recvbuf,
@@ -87,8 +99,8 @@ h5priv_mpi_sum (
 		comm
 		);
 	if (err != MPI_SUCCESS)
-		return h5_error (H5_ERR_MPI, "Cannot perform sum reduction");
-	return H5_SUCCESS;
+		MPI_WRAPPER_LEAVE (h5_error (H5_ERR_MPI, "Cannot perform sum reduction"));
+	MPI_WRAPPER_RETURN (H5_SUCCESS);
 }
 
 h5_err_t
@@ -99,6 +111,9 @@ h5priv_mpi_prefix_sum (
 	const MPI_Datatype type,
 	const MPI_Comm comm
 	) {
+	MPI_WRAPPER_ENTER3 (h5_err_t,
+			   "sendbuf=0x%p, recvbuf=0x%p, count=%d, type=?, comm=?",
+			    sendbuf, recvbuf, count);
 	int err = MPI_Scan(
 		sendbuf,
 		recvbuf,
@@ -108,8 +123,8 @@ h5priv_mpi_prefix_sum (
 		comm
 		);
 	if (err != MPI_SUCCESS)
-		return h5_error (H5_ERR_MPI, "Cannot perform prefix sum");
-	return H5_SUCCESS;
+		MPI_WRAPPER_LEAVE (h5_error (H5_ERR_MPI, "Cannot perform prefix sum"));
+	MPI_WRAPPER_RETURN (H5_SUCCESS);
 }
 
 h5_err_t
@@ -122,6 +137,9 @@ h5priv_mpi_allgather (
 	const MPI_Datatype recvtype,
 	const MPI_Comm comm
 	) {
+	MPI_WRAPPER_ENTER4 (h5_err_t,
+			   "sendbuf=0x%p, sendcount=%d, sendtype=?, recvbuf=0x%p, recvcount=%d, recvtype=?, comm=?",
+			    sendbuf, sendcount, recvbuf, recvcount);
 	int err = MPI_Allgather (
 		sendbuf,
 		sendcount,
@@ -131,8 +149,8 @@ h5priv_mpi_allgather (
 		recvtype,
 		comm);
 	if (err != MPI_SUCCESS)
-		return h5_error (H5_ERR_MPI, "Cannot gather data");
-	return H5_SUCCESS;
+		MPI_WRAPPER_LEAVE (h5_error (H5_ERR_MPI, "Cannot gather data"));
+	MPI_WRAPPER_RETURN (H5_SUCCESS);
 }
 
 h5_err_t
@@ -140,10 +158,12 @@ h5priv_mpi_comm_size (
 	MPI_Comm comm,
 	int* size
 	) {
+	MPI_WRAPPER_ENTER1 (h5_err_t,
+			    "comm=?, size=0x%p", size);
 	int err = MPI_Comm_size (comm, size);
 	if (err != MPI_SUCCESS)
-		return h5_error (H5_ERR_MPI, "Cannot get communicator size");
-	return H5_SUCCESS;
+		MPI_WRAPPER_LEAVE (h5_error (H5_ERR_MPI, "Cannot get communicator size"));
+	MPI_WRAPPER_RETURN (H5_SUCCESS);
 }
 
 
@@ -152,10 +172,12 @@ h5priv_mpi_comm_rank (
 	MPI_Comm comm,
 	int* rank
 	) {
+	MPI_WRAPPER_ENTER1 (h5_err_t,
+			    "comm=?, rank=0x%p", rank);
 	int err = MPI_Comm_rank (comm, rank);
 	if (err != MPI_SUCCESS)
-		return h5_error (H5_ERR_MPI, "Cannot get this task's rank");
-	return H5_SUCCESS;
+		MPI_WRAPPER_LEAVE (h5_error (H5_ERR_MPI, "Cannot get this task's rank"));
+	MPI_WRAPPER_RETURN (H5_SUCCESS);
 }
 
 h5_err_t
@@ -164,24 +186,26 @@ h5priv_mpi_type_contiguous (
 	const MPI_Datatype oldtype,
 	MPI_Datatype *const newtype
 	) {
+	MPI_WRAPPER_ENTER1 (h5_err_t, "nelems=%lu, oldtype=?, newtype=?", (long unsigned)nelems);
 	int err;
 	err = MPI_Type_contiguous ( nelems, oldtype, newtype );
 	if (err != MPI_SUCCESS)
-		return h5_error (H5_ERR_MPI, "Cannot create new MPI type");
+		MPI_WRAPPER_LEAVE (h5_error (H5_ERR_MPI, "Cannot create new MPI type"));
 	err = MPI_Type_commit ( newtype );
 	if (err != MPI_SUCCESS)
-		return h5_error (H5_ERR_MPI, "Cannot commit new MPI type");
-	return H5_SUCCESS;
+		MPI_WRAPPER_LEAVE (h5_error (H5_ERR_MPI, "Cannot commit new MPI type"));
+	MPI_WRAPPER_RETURN (H5_SUCCESS);
 }
 
 h5_err_t
 h5priv_mpi_type_free (
 	MPI_Datatype *type
 	) {
+	MPI_WRAPPER_ENTER1 (h5_err_t, "type=0x%p", type);
 	int err = MPI_Type_free( type );
 	if (err != MPI_SUCCESS)
-		return h5_error(H5_ERR_MPI, "Cannot free MPI type");
-	return H5_SUCCESS;
+		MPI_WRAPPER_LEAVE (h5_error(H5_ERR_MPI, "Cannot free MPI type"));
+	MPI_WRAPPER_RETURN (H5_SUCCESS);
 }
 
 h5_err_t
@@ -193,11 +217,13 @@ h5priv_mpi_cart_create (
 	int reorder,
 	MPI_Comm *new_comm
 	) {
+	MPI_WRAPPER_ENTER5 (h5_err_t, "old_comm=?, ndims=%d, dims=0x%p, period=0x%p, reorder=%d, new_comm=0x%p",
+			    ndims, dims, period, reorder, new_comm);
 	int err = MPI_Cart_create(
 		old_comm, ndims, dims, period, reorder, new_comm);
 	if (err != MPI_SUCCESS)
-		return h5_error(H5_ERR_MPI, "Cannot create cartesian grid");
-	return H5_SUCCESS;
+		MPI_WRAPPER_LEAVE (h5_error(H5_ERR_MPI, "Cannot create cartesian grid"));
+	MPI_WRAPPER_RETURN (H5_SUCCESS);
 }
 
 h5_err_t
@@ -207,10 +233,12 @@ h5priv_mpi_cart_coords (
 	int maxdim,
 	int *coords
 	) {
+	MPI_WRAPPER_ENTER3 (h5_err_t, "comm=?, rank=%d, maxdim=%d, coords=0x%p",
+			    rank, maxdim, coords);
 	int err = MPI_Cart_coords( comm, rank, maxdim, coords );
 	if (err != MPI_SUCCESS)
-		return h5_error(H5_ERR_MPI, "Cannot create cartesian grid");
-	return H5_SUCCESS;
+		MPI_WRAPPER_LEAVE (h5_error(H5_ERR_MPI, "Cannot create cartesian grid"));
+	MPI_WRAPPER_RETURN (H5_SUCCESS);
 }
 
 #endif // PARALLEL_IO
diff --git a/src/include/h5core/h5_core.h b/src/include/h5core/h5_core.h
index b11bb07..e03ca15 100644
--- a/src/include/h5core/h5_core.h
+++ b/src/include/h5core/h5_core.h
@@ -13,8 +13,10 @@ extern "C" {
 #define H5_DEBUG_PRIV_API	(1<<5)
 #define H5_DEBUG_PRIV_FUNC	(1<<6)
 #define H5_DEBUG_HDF5		(1<<7)
-#define H5_DEBUG_MALLOC		(1<<8)
-#define H5_DEBUG_CLIB		(1<<9)
+#define H5_DEBUG_MPI		(1<<8)
+#define H5_DEBUG_MALLOC		(1<<9)
+#define H5_DEBUG_CLIB		(1<<10)
+
 #define H5_DEBUG_ALL		(-1)
 
 extern char* h5_rfmts[];