diff --git a/.gitattributes b/.gitattributes
index e05abd7..66d0215 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -487,6 +487,7 @@ src/include/h5core/h5_hdf5.h -text
 src/include/h5core/h5_maps.h -text
 src/include/h5core/h5_openclose.h -text
 src/include/h5core/h5_readwrite.h -text
+src/include/h5core/h5_syscall.h -text
 src/include/h5core/h5_types.h -text
 src/include/h5core/h5b_attribs.h -text
 src/include/h5core/h5b_model.h -text
diff --git a/src/C/H5.c b/src/C/H5.c
index 52173c8..3f6aeef 100644
--- a/src/C/H5.c
+++ b/src/C/H5.c
@@ -64,8 +64,9 @@ h5_err_t
 H5CloseFile (
 	h5_file_t* const f		/*!< file handle		*/
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5_close_file (f);
+	H5_API_ENTER;
+	h5_err_t h5err = h5_close_file (f);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -79,8 +80,9 @@ h5_err_t
 H5CheckFile (
 	h5_file_t* const f		/*!< file handle		*/
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5_check_filehandle (f);
+	H5_API_ENTER;
+	h5_err_t h5err = h5_check_filehandle (f);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -99,9 +101,9 @@ H5SetStepNameFormat (
 	const char* name,		/*!< Prefix			*/
 	const h5_int64_t width		/*!< Width of the number	*/
 	) {
-	H5_ENTER_API (f, __func__);
-
-	return h5_set_stepname_fmt (f, name, width);
+	H5_API_ENTER;
+	h5_err_t h5err = h5_set_stepname_fmt (f, name, width);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -119,9 +121,9 @@ H5GetStepNameFormat (
 	const h5_size_t l_name,		/*!< length of buffer name	*/
 	int* width			/*!< OUT: Width of the number	*/
 	) {
-	H5_ENTER_API (f, __func__);
-
-	return h5_get_stepname_fmt (f, name, l_name, width);
+	H5_API_ENTER;
+	h5_err_t h5err = h5_get_stepname_fmt (f, name, l_name, width);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -137,8 +139,9 @@ H5SetStep (
 	const h5_id_t step		/*!< [in]  Step to set. */
 	) {
 
-	H5_ENTER_API (f, __func__);
-	return h5_set_step (f, step);
+	H5_API_ENTER;
+	h5_err_t h5err = h5_set_step (f, step);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -153,8 +156,9 @@ H5GetStep (
 	h5_file_t* const f		/*!< Handle to open file */
 	) {
 
-	H5_ENTER_API (f, __func__);
-	return h5_get_step (f);
+	H5_API_ENTER;
+	h5_id_t id = h5_get_step (f);
+	H5_API_RETURN (id);
 }
 
 /*!
@@ -171,8 +175,9 @@ int
 H5GetNumProcs (
 	h5_file_t* const f
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5_get_num_procs(f);
+	H5_API_ENTER;
+	int nprocs = h5_get_num_procs(f);
+	H5_API_RETURN (nprocs);
 }
 
 /*!
@@ -192,10 +197,9 @@ h5_ssize_t
 H5GetNumSteps (
 	h5_file_t* const f
 	) {
-
-	H5_ENTER_API (f, __func__);
-
-	return h5_get_num_steps(f);
+	H5_API_ENTER;
+	h5_ssize_t nsteps = h5_get_num_steps(f);
+	H5_API_RETURN (nsteps);
 }
 
 /*!
@@ -213,10 +217,9 @@ H5HasStep (
 	h5_file_t* const f,
 	h5_id_t stepno
 	) {
-  
-	H5_ENTER_API (f, __func__);
-
-	return h5_has_step (f, stepno);
+  	H5_API_ENTER;
+	h5_err_t h5err = h5_has_step (f, stepno);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -230,10 +233,9 @@ h5_err_t
 H5StartTraverseSteps (
 	h5_file_t* const f		/*!< Handle to open file */
 	) {
-
-	H5_ENTER_API (f, __func__);
-
-	return h5_start_traverse_steps (f);
+	H5_API_ENTER;
+	h5_err_t h5err = h5_start_traverse_steps (f);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -247,10 +249,9 @@ h5_err_t
 H5TraverseSteps (
 	h5_file_t* const f		/*!< Handle to open file */
 	) {
-
-	H5_ENTER_API (f, __func__);
-
-	return h5_traverse_steps (f);
+	H5_API_ENTER;
+	h5_err_t h5err = h5_traverse_steps (f);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -275,10 +276,9 @@ H5SetThrottle (
 	h5_file_t* f,
 	int factor
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_set_throttle( f, factor );
+	H5_API_ENTER( f, __func__ );
+	h5_err_t h5err = h5_set_throttle( f, factor );
+	H5_API_RETURN (h5err);
 }
 #endif // PARALLEL_IO
 
diff --git a/src/C/H5Block.c b/src/C/H5Block.c
index 6e06d8d..4711f8a 100644
--- a/src/C/H5Block.c
+++ b/src/C/H5Block.c
@@ -72,10 +72,9 @@ h5_int64_t
 H5Block3dHasView (
 	h5_file_t *const f	/*!< IN: File handle */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_3d_has_view(f);
+	H5_API_ENTER;
+	h5_int64_t retval = h5b_3d_has_view(f);
+	H5_API_RETURN (retval);
 }
 
 /*!
@@ -101,10 +100,9 @@ H5Block3dSetView (
 	const h5_int64_t k_start,	/*!< IN: start index of \c k	*/ 
 	const h5_int64_t k_end	        /*!< IN: end index of \c k	*/
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_3d_set_view(f, i_start, i_end, j_start, j_end, k_start, k_end);
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_3d_set_view(f, i_start, i_end, j_start, j_end, k_start, k_end);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -124,10 +122,9 @@ H5Block3dGetView (
 	h5_size_t *k_start,	/*!< OUT: start index of \c k	*/ 
 	h5_size_t *k_end	/*!< OUT: end index of \c k	*/ 
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_3d_get_view(f, i_start, i_end, j_start, j_end, k_start, k_end);
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_3d_get_view(f, i_start, i_end, j_start, j_end, k_start, k_end);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -147,10 +144,9 @@ H5Block3dGetReducedView (
 	h5_size_t *const k_start,	/*!< OUT: start index of \c j */ 
 	h5_size_t *const k_end		/*!< OUT: end index of \c j */ 
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_3d_get_reduced_view(f, i_start, i_end, j_start, j_end, k_start, k_end);
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_3d_get_reduced_view(f, i_start, i_end, j_start, j_end, k_start, k_end);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -168,10 +164,9 @@ H5Block3dSetChunk (
 	const h5_size_t j,		/*!< IN: size of \c j */  
 	const h5_size_t k		/*!< IN: size of \c k */ 
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_3d_set_chunk(f, i, j, k);
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_3d_set_chunk(f, i, j, k);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -189,10 +184,9 @@ H5Block3dGetChunk (
 	h5_size_t *const j,		/*!< OUT: size of \c j */  
 	h5_size_t *const k		/*!< OUT: size of \c k */ 
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_3d_get_chunk(f, field_name, i, j, k);
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_3d_get_chunk(f, field_name, i, j, k);
+	H5_API_RETURN (h5err);
 }
 
 #ifdef PARALLEL_IO
@@ -217,10 +211,9 @@ H5Block3dSetGrid (
 	const h5_size_t j,		/*!< IN: dimension in \c j */  
 	const h5_size_t k		/*!< IN: dimension in \c k */ 
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_3d_set_grid(f, i, j, k);
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_3d_set_grid(f, i, j, k);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -239,10 +232,9 @@ H5Block3dGetGridCoords (
 	h5_int64_t *j,			/*!< OUT: index in \c j */  
 	h5_int64_t *k			/*!< OUT: index in \c k */ 
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_3d_get_grid_coords(f, proc, i, j, k);
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_3d_get_grid_coords(f, proc, i, j, k);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -263,10 +255,9 @@ H5Block3dSetDims (
 	const h5_size_t j,		/*!< IN: dimension in \c j */  
 	const h5_size_t k		/*!< IN: dimension in \c k */ 
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_3d_set_dims(f, i, j, k);
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_3d_set_dims(f, i, j, k);
+	H5_API_RETURN (h5err);
 }
 #endif
 
@@ -289,10 +280,9 @@ H5Block3dSetHalo (
 	const h5_size_t j,		/*!< IN: radius in \c j */  
 	const h5_size_t k		/*!< IN: radius in \c k */ 
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_3d_set_halo(f, i, j, k);
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_3d_set_halo(f, i, j, k);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -306,10 +296,9 @@ h5_size_t
 H5BlockGetNumFields (
 	h5_file_t *const f			/*!< IN: file handle */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_get_num_fields(f);
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_get_num_fields(f);
+	H5_API_RETURN (h5err);
 }
 
 
@@ -340,11 +329,10 @@ H5BlockGetFieldInfo (
 	h5_size_t *elem_rank,			/*!< OUT: element rank */
 	h5_int64_t *type			/*!< OUT: datatype */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_get_field_info (f,
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_get_field_info (f,
 		idx, name, len_name, field_rank, field_dims, elem_rank, type);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -364,11 +352,10 @@ H5BlockGetFieldInfoByName (
 	h5_size_t *elem_rank,			/*!< OUT: element rank */
 	h5_int64_t *type		/*!< OUT: datatype */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_get_field_info_by_name (f,
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_get_field_info_by_name (f,
 		name, field_rank, field_dims, elem_rank, type );
+	H5_API_RETURN (h5err);
 }
 
 /********************** reading and writing attribute ************************/
@@ -388,16 +375,15 @@ H5BlockWriteFieldAttribString (
 	const char *attrib_name,		/*!< IN: attribute name */
 	const char *value			/*!< IN: attribute value */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_write_field_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_write_field_attrib (
 		f,
 		field_name,
 		attrib_name,
 		H5T_NATIVE_CHAR,
 		value,
 		strlen(value) + 1 );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -415,15 +401,14 @@ H5BlockReadFieldAttribString (
 	const char *attrib_name,		/*!< IN: attribute name */
 	char *buffer			        /*!< OUT: attribute value */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_read_field_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_read_field_attrib (
 		f,
 		field_name,
 		attrib_name,
 		H5_STRING_T,
 		(void*)buffer);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -438,10 +423,9 @@ H5BlockGetNumFieldAttribs (
 	h5_file_t *const f,			/*<! IN: file handle */
 	const char *field_name			/*<! IN: field name */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_get_num_field_attribs(f, field_name);
+	H5_API_ENTER;
+	h5_ssize_t nattribs = h5b_get_num_field_attribs(f, field_name);
+	H5_API_RETURN (nattribs);
 }
 
 /*!
@@ -469,10 +453,8 @@ H5BlockGetFieldAttribInfo (
 	h5_int64_t *attrib_type,	/*<! OUT: Type of value. */
 	h5_size_t *attrib_nelem         /*<! OUT: Number of elements */
 	) {
-	
-	H5_ENTER_API ( f, __func__ );
-
-	return h5b_get_field_attrib_info (
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_get_field_attrib_info (
 		f,
 		field_name,
 		attrib_idx,
@@ -480,5 +462,6 @@ H5BlockGetFieldAttribInfo (
 		len_of_attrib_name,
 		attrib_type,
 		attrib_nelem );
+	H5_API_RETURN (h5err);
 }
 
diff --git a/src/C/H5Block_readwrite.c b/src/C/H5Block_readwrite.c
index 794a219..6383759 100644
--- a/src/C/H5Block_readwrite.c
+++ b/src/C/H5Block_readwrite.c
@@ -19,10 +19,9 @@ H5Block3dWriteScalarFieldFloat64 (
 	const char *name,	       /*!< IN: name of dataset to write */
 	const h5_float64_t *data      /*!< IN: scalar data to write */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_write_scalar_data(f, name, (void*)data, H5T_NATIVE_DOUBLE );
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_write_scalar_data(f, name, (void*)data, H5T_NATIVE_DOUBLE );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -42,10 +41,9 @@ H5Block3dReadScalarFieldFloat64 (
 	const char *name,	       /*!< IN: name of dataset to read */
 	h5_float64_t *data	  /*!< OUT: ptr to read buffer */
 	) {
-
-	H5_ENTER_API( f, __func__ );	
-
-	return h5b_read_scalar_data(f, name, (void*)data, H5T_NATIVE_DOUBLE);
+	H5_API_ENTER;	
+	h5_err_t h5err = h5b_read_scalar_data(f, name, (void*)data, H5T_NATIVE_DOUBLE);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -69,11 +67,10 @@ H5Block3dWriteVector3dFieldFloat64 (
 	const h5_float64_t *y_data, /*!< IN: Y axis data */
 	const h5_float64_t *z_data  /*!< IN: Z axis data */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_write_vector3d_data(f, name,
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_write_vector3d_data(f, name,
 		(void*)x_data, (void*)y_data, (void*)z_data, H5T_NATIVE_DOUBLE);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -97,11 +94,10 @@ H5Block3dReadVector3dFieldFloat64 (
 	h5_float64_t *y_data, /*!< OUT: Y axis data */
 	h5_float64_t *z_data  /*!< OUT: Z axis data */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-	
-	return h5b_read_vector3d_data(f, name,
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_read_vector3d_data(f, name,
 		(void*)x_data, (void*)y_data, (void*)z_data, H5T_NATIVE_DOUBLE);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -121,10 +117,9 @@ H5Block3dWriteScalarFieldFloat32 (
 	const char *name,	       /*!< IN: name of dataset to write */
 	const h5_float32_t *data      /*!< IN: scalar data to write */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_write_scalar_data(f, name, (void*)data, H5T_NATIVE_FLOAT );
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_write_scalar_data(f, name, (void*)data, H5T_NATIVE_FLOAT );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -144,10 +139,9 @@ H5Block3dReadScalarFieldFloat32 (
 	const char *name,	       /*!< IN: name of dataset to read */
 	h5_float32_t *data	  /*!< OUT: ptr to read buffer */
 	) {
-
-	H5_ENTER_API( f, __func__ );	
-
-	return h5b_read_scalar_data(f, name, (void*)data, H5T_NATIVE_FLOAT);
+	H5_API_ENTER;	
+	h5_err_t h5err = h5b_read_scalar_data(f, name, (void*)data, H5T_NATIVE_FLOAT);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -171,11 +165,10 @@ H5Block3dWriteVector3dFieldFloat32 (
 	const h5_float32_t *y_data, /*!< IN: Y axis data */
 	const h5_float32_t *z_data  /*!< IN: Z axis data */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_write_vector3d_data(f, name,
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_write_vector3d_data(f, name,
 		(void*)x_data, (void*)y_data, (void*)z_data, H5T_NATIVE_FLOAT);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -199,11 +192,10 @@ H5Block3dReadVector3dFieldFloat32 (
 	h5_float32_t *y_data, /*!< OUT: Y axis data */
 	h5_float32_t *z_data  /*!< OUT: Z axis data */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-	
-	return h5b_read_vector3d_data(f, name,
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_read_vector3d_data(f, name,
 		(void*)x_data, (void*)y_data, (void*)z_data, H5T_NATIVE_FLOAT);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -223,10 +215,9 @@ H5Block3dWriteScalarFieldInt64 (
 	const char *name,	       /*!< IN: name of dataset to write */
 	const h5_int64_t *data      /*!< IN: scalar data to write */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_write_scalar_data(f, name, (void*)data, H5T_NATIVE_INT64 );
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_write_scalar_data(f, name, (void*)data, H5T_NATIVE_INT64 );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -246,10 +237,9 @@ H5Block3dReadScalarFieldInt64 (
 	const char *name,	       /*!< IN: name of dataset to read */
 	h5_int64_t *data	  /*!< OUT: ptr to read buffer */
 	) {
-
-	H5_ENTER_API( f, __func__ );	
-
-	return h5b_read_scalar_data(f, name, (void*)data, H5T_NATIVE_INT64);
+	H5_API_ENTER;	
+	h5_err_t h5err = h5b_read_scalar_data(f, name, (void*)data, H5T_NATIVE_INT64);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -273,11 +263,10 @@ H5Block3dWriteVector3dFieldInt64 (
 	const h5_int64_t *y_data, /*!< IN: Y axis data */
 	const h5_int64_t *z_data  /*!< IN: Z axis data */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_write_vector3d_data(f, name,
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_write_vector3d_data(f, name,
 		(void*)x_data, (void*)y_data, (void*)z_data, H5T_NATIVE_INT64);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -301,11 +290,10 @@ H5Block3dReadVector3dFieldInt64 (
 	h5_int64_t *y_data, /*!< OUT: Y axis data */
 	h5_int64_t *z_data  /*!< OUT: Z axis data */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-	
-	return h5b_read_vector3d_data(f, name,
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_read_vector3d_data(f, name,
 		(void*)x_data, (void*)y_data, (void*)z_data, H5T_NATIVE_INT64);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -325,10 +313,9 @@ H5Block3dWriteScalarFieldInt32 (
 	const char *name,	       /*!< IN: name of dataset to write */
 	const h5_int32_t *data      /*!< IN: scalar data to write */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_write_scalar_data(f, name, (void*)data, H5T_NATIVE_INT32 );
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_write_scalar_data(f, name, (void*)data, H5T_NATIVE_INT32 );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -348,10 +335,9 @@ H5Block3dReadScalarFieldInt32 (
 	const char *name,	       /*!< IN: name of dataset to read */
 	h5_int32_t *data	  /*!< OUT: ptr to read buffer */
 	) {
-
-	H5_ENTER_API( f, __func__ );	
-
-	return h5b_read_scalar_data(f, name, (void*)data, H5T_NATIVE_INT32);
+	H5_API_ENTER;	
+	h5_err_t h5err = h5b_read_scalar_data(f, name, (void*)data, H5T_NATIVE_INT32);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -375,11 +361,10 @@ H5Block3dWriteVector3dFieldInt32 (
 	const h5_int32_t *y_data, /*!< IN: Y axis data */
 	const h5_int32_t *z_data  /*!< IN: Z axis data */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5b_write_vector3d_data(f, name,
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_write_vector3d_data(f, name,
 		(void*)x_data, (void*)y_data, (void*)z_data, H5T_NATIVE_INT32);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -403,11 +388,10 @@ H5Block3dReadVector3dFieldInt32 (
 	h5_int32_t *y_data, /*!< OUT: Y axis data */
 	h5_int32_t *z_data  /*!< OUT: Z axis data */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-	
-	return h5b_read_vector3d_data(f, name,
+	H5_API_ENTER;
+	h5_err_t h5err = h5b_read_vector3d_data(f, name,
 		(void*)x_data, (void*)y_data, (void*)z_data, H5T_NATIVE_INT32);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -426,16 +410,15 @@ H5BlockWriteFieldAttribFloat64 (
 	const h5_float64_t *values,		/*!< IN: attribute values */
 	const h5_size_t nvalues			/*!< IN: number of elements */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_write_field_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_write_field_attrib (
 		f,
 		field_name,
 		attrib_name,
                 H5T_NATIVE_DOUBLE,
                 values,
 		nvalues );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -453,15 +436,14 @@ H5BlockReadFieldAttribFloat64 (
 	const char *attrib_name,		/*!< IN: attribute name */
 	h5_float64_t *buffer		        /*!< OUT: attribute values */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_read_field_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_read_field_attrib (
 		f,
 		field_name,
 		attrib_name,
                 H5T_NATIVE_DOUBLE,
                 (void*)buffer);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -480,16 +462,15 @@ H5BlockWriteFieldAttribFloat32 (
 	const h5_float32_t *values,		/*!< IN: attribute values */
 	const h5_size_t nvalues			/*!< IN: number of elements */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_write_field_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_write_field_attrib (
 		f,
 		field_name,
 		attrib_name,
                 H5T_NATIVE_FLOAT,
                 values,
 		nvalues );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -507,15 +488,14 @@ H5BlockReadFieldAttribFloat32 (
 	const char *attrib_name,		/*!< IN: attribute name */
 	h5_float32_t *buffer		        /*!< OUT: attribute values */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_read_field_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_read_field_attrib (
 		f,
 		field_name,
 		attrib_name,
                 H5T_NATIVE_FLOAT,
                 (void*)buffer);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -534,16 +514,15 @@ H5BlockWriteFieldAttribInt64 (
 	const h5_int64_t *values,		/*!< IN: attribute values */
 	const h5_size_t nvalues			/*!< IN: number of elements */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_write_field_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_write_field_attrib (
 		f,
 		field_name,
 		attrib_name,
                 H5T_NATIVE_INT64,
                 values,
 		nvalues );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -561,15 +540,14 @@ H5BlockReadFieldAttribInt64 (
 	const char *attrib_name,		/*!< IN: attribute name */
 	h5_int64_t *buffer		        /*!< OUT: attribute values */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_read_field_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_read_field_attrib (
 		f,
 		field_name,
 		attrib_name,
                 H5T_NATIVE_INT64,
                 (void*)buffer);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -588,16 +566,15 @@ H5BlockWriteFieldAttribInt32 (
 	const h5_int32_t *values,		/*!< IN: attribute values */
 	const h5_size_t nvalues			/*!< IN: number of elements */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_write_field_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_write_field_attrib (
 		f,
 		field_name,
 		attrib_name,
                 H5T_NATIVE_INT32,
                 values,
 		nvalues );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -615,13 +592,12 @@ H5BlockReadFieldAttribInt32 (
 	const char *attrib_name,		/*!< IN: attribute name */
 	h5_int32_t *buffer		        /*!< OUT: attribute values */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_read_field_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_read_field_attrib (
 		f,
 		field_name,
 		attrib_name,
                 H5T_NATIVE_INT32,
                 (void*)buffer);
+	H5_API_RETURN (h5err);
 }
diff --git a/src/C/H5Fed.c b/src/C/H5Fed.c
index 63f7e5d..2395c4a 100644
--- a/src/C/H5Fed.c
+++ b/src/C/H5Fed.c
@@ -21,16 +21,18 @@ H5FedOpenMesh (
 	const h5_id_t mesh_id,
 	const h5_oid_t mesh_type_id
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_open_mesh (f, mesh_id, mesh_type_id);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_open_mesh (f, mesh_id, mesh_type_id);
+	H5_API_RETURN (h5err);
 }
 
 h5_err_t
 H5FedCloseMesh (
 	h5_file_t* const f
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_close_mesh (f);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_close_mesh (f);
+	H5_API_RETURN (h5err);
 }
 
 h5_err_t
@@ -38,8 +40,9 @@ H5FedSetLevel (
 	h5_file_t* const f,
 	const h5_id_t level_id
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_set_level (f, level_id);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_set_level (f, level_id);
+	H5_API_RETURN (h5err);
 }
 
 h5_err_t
@@ -48,5 +51,7 @@ H5FedLinkMeshToStep (
 	const h5_id_t mesh_id
 	) {
 	UNUSED_ARGUMENT (mesh_id);
-	return h5_error_not_implemented (f, __FILE__, __func__, __LINE__);
+	H5_API_ENTER;
+	h5_err_t h5err = h5_error_not_implemented (f, __FILE__, __func__, __LINE__);
+	H5_API_RETURN (h5err);
 }
diff --git a/src/C/H5Fed_adjacency.c b/src/C/H5Fed_adjacency.c
index a64fac1..755a46c 100644
--- a/src/C/H5Fed_adjacency.c
+++ b/src/C/H5Fed_adjacency.c
@@ -28,8 +28,9 @@ H5FedGetAdjacencies (
 	const h5_int32_t dim,
 	h5_idlist_t** list
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_get_adjacencies (f, entity_id, dim, list);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_get_adjacencies (f, entity_id, dim, list);
+	H5_API_RETURN (h5err);
 }
 
 h5_err_t
@@ -37,6 +38,7 @@ H5FedReleaseListOfAdjacencies (
 	h5_file_t* const f,
 	h5_idlist_t** list
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_release_list_of_adjacencies (f, list);
+	H5_API_ENTER
+	h5_err_t h5err = h5t_release_list_of_adjacencies (f, list);
+	H5_API_RETURN (h5err);
 }
diff --git a/src/C/H5Fed_inquiry.c b/src/C/H5Fed_inquiry.c
index 0600201..646385c 100644
--- a/src/C/H5Fed_inquiry.c
+++ b/src/C/H5Fed_inquiry.c
@@ -28,13 +28,14 @@
 
   \return	Number of meshes of type \c type_id or error code.
  */
-h5_size_t
+h5_ssize_t
 H5FedGetNumMeshes ( 
 	h5_file_t* const f,
 	const h5_oid_t type_id
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_get_num_meshes (f, type_id);
+	H5_API_ENTER;
+	h5_ssize_t num = h5t_get_num_meshes (f, type_id);
+	H5_API_RETURN (num);
 }
 
 /*!
@@ -44,12 +45,13 @@ H5FedGetNumMeshes (
 
   \return	Number of hierarchical mesh levels or error code.
  */
-h5_size_t
+h5_ssize_t
 H5FedGetNumLevels (
 	h5_file_t* const f
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_get_num_levels (f);
+	H5_API_ENTER;
+	h5_ssize_t num = h5t_get_num_levels (f);
+	H5_API_RETURN (num);
 }
 
 /*!
@@ -59,12 +61,13 @@ H5FedGetNumLevels (
 
   \return	ID of current mesh levels or error code.
  */
-h5_id_t
+h5t_lvl_idx_t
 H5FedGetLevel (
 	h5_file_t* const f
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_get_level (f);
+	H5_API_ENTER;
+	h5_ssize_t num = h5t_get_level (f);
+	H5_API_RETURN (num);
 }
 
 /*!
@@ -75,14 +78,15 @@ H5FedGetLevel (
 
   \return	Number of vertices or error code.
 */
-h5_size_t
+h5_ssize_t
 H5FedGetNumVertices (
 	h5_file_t* const f		/*!< file handle		*/
 	) {
-	H5_ENTER_API (f, __func__);
+	H5_API_ENTER;
 	// MLH: can't use field from opaque h5_file_t!
 	//return h5t_get_num_vertices (f, f->myproc);
-	return h5t_get_num_vertices (f, -1);
+	h5_ssize_t num = h5t_get_num_vertices (f, -1);
+	H5_API_RETURN (num);
 }
 
 /*!
@@ -94,13 +98,14 @@ H5FedGetNumVertices (
 
   \return	Number of vertices or error code.
 */
-h5_size_t
+h5_ssize_t
 H5FedGetNumVerticesCnode (
 	h5_file_t* const f,
 	const h5_id_t cnode
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_get_num_vertices (f, cnode);
+	H5_API_ENTER;
+	h5_ssize_t num = h5t_get_num_vertices (f, cnode);
+	H5_API_RETURN (num);
 }
 
 /*!
@@ -111,12 +116,13 @@ H5FedGetNumVerticesCnode (
 
   \return	Total number of vertices or error code.
 */
-h5_size_t
+h5_ssize_t
 H5FedGetNumVerticesTotal (
 	h5_file_t* const f
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_get_num_vertices (f, -1);
+	H5_API_ENTER;
+	h5_ssize_t num = h5t_get_num_vertices (f, -1);
+	H5_API_RETURN (num);
 }
 
 /*!
@@ -127,14 +133,15 @@ H5FedGetNumVerticesTotal (
 
   \return	Number of elements or error code.
 */
-h5_size_t
+h5_ssize_t
 H5FedGetNumElements (
 	h5_file_t* const f
 	) {
-	H5_ENTER_API (f, __func__);
+	H5_API_ENTER;
 	// MLH: can't use field from opaque h5_file_t!
-	//return h5t_get_num_elems (f, f->myproc);
-	return h5t_get_num_elems (f, -1);
+	//h5_ssize_t num = h5t_get_num_elems (f, f->myproc);
+	h5_ssize_t num = h5t_get_num_elems (f, -1);
+	H5_API_RETURN (num);
 }
 
 /*!
@@ -146,13 +153,14 @@ H5FedGetNumElements (
 
   \return	Number of elements or error code.
 */
-h5_size_t
+h5_ssize_t
 H5FedGetNumElementsCnode (
 	h5_file_t* const f,
 	const h5_id_t cnode
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_get_num_elems (f, cnode);
+	H5_API_ENTER;
+	h5_ssize_t num = h5t_get_num_elems (f, cnode);
+	H5_API_RETURN (num);
 }
 /*!
   Returns the number of elements present in the mesh
@@ -162,10 +170,11 @@ H5FedGetNumElementsCnode (
 
   \return	Number of elements or error code.
 */
-h5_size_t
+h5_ssize_t
 H5FedGetNumElementsTotal (
 	h5_file_t* const f
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_get_num_elems (f, -1);
+	H5_API_ENTER;
+	h5_ssize_t num = h5t_get_num_elems (f, -1);
+	H5_API_RETURN (num);
 }
diff --git a/src/C/H5Fed_retrieve.c b/src/C/H5Fed_retrieve.c
index 89f45d5..4cd31de 100644
--- a/src/C/H5Fed_retrieve.c
+++ b/src/C/H5Fed_retrieve.c
@@ -36,12 +36,11 @@ H5FedBeginTraverseEntities (
 	h5_file_t* const f,
 	const int codim
 	) {
+	H5_API_ENTER;
 	h5t_iterator_t* iter;
-	H5_ENTER_API (f, __func__);
-	if (h5t_create_leaf_iterator (f, &iter, codim) < 0) {
-		return (void*)H5_ERR;
-	}
-	return iter;
+	TRY2( iter = h5_calloc (f, 1, sizeof (*iter)) );
+	TRY2( h5t_init_leaf_iterator (f, iter, codim) );
+	H5_API_RETURN (iter);
 }
 
 h5t_iterator_t*
@@ -49,12 +48,11 @@ H5FedBeginTraverseBoundaryFaces (
 	h5_file_t* const f,
 	const int codim
 	) {
+	H5_API_ENTER;
 	h5t_iterator_t* iter;
-	H5_ENTER_API (f, __func__);
-	if (h5t_create_boundary_face_iterator (f, &iter, codim) < 0) {
-		return (void*)H5_ERR;
-	}
-	return iter;
+	TRY2( iter = h5_calloc (f, 1, sizeof (*iter)) );
+	TRY2( h5t_init_boundary_face_iterator (f, iter, codim) );
+	H5_API_RETURN (iter);
 }
 
 /*!
@@ -67,13 +65,14 @@ H5FedBeginTraverseBoundaryFaces (
   \return		-1, if done
   \return		error code on error
   */
-h5_id_t
+h5_loc_id_t
 H5FedTraverseEntities (
 	h5_file_t* const f,
 	h5t_iterator_t* iter
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_iterate_entities (f, iter);
+	H5_API_ENTER;
+	h5_loc_id_t id = h5t_iterate_entities (f, iter);
+	H5_API_RETURN (id);
 }
 
 /*!
@@ -89,8 +88,9 @@ H5FedEndTraverseEntities (
 	h5_file_t* const f,
 	h5t_iterator_t* iter
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_release_entity_iterator (f, iter);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_release_entity_iterator (f, iter);
+	H5_API_RETURN (h5err);
 }
 
 
@@ -109,8 +109,9 @@ H5FedGetVertexCoordsByIndex (
 	h5_id_t vertex_index,
 	h5_float64_t P[3]
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_get_vertex_coords_by_index (f, vertex_index, P);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_get_vertex_coords_by_index (f, vertex_index, P);
+	H5_API_RETURN (h5err);
 }
 
 h5_err_t
@@ -119,8 +120,9 @@ H5FedGetVertexCoordsByID (
 	h5_id_t vertex_id,
 	h5_float64_t P[3]
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_get_vertex_coords_by_id (f, vertex_id, P);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_get_vertex_coords_by_id (f, vertex_id, P);
+	H5_API_RETURN (h5err);
 }
 
 h5_err_t
@@ -129,8 +131,9 @@ H5FedGetVertexIndicesOfEdge (
 	h5_id_t entity_id,
 	h5_id_t* vertex_indices
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_get_vertex_indices_of_edge (f, entity_id, vertex_indices);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_get_vertex_indices_of_edge (f, entity_id, vertex_indices);
+	H5_API_RETURN (h5err);
 }
 
 h5_err_t
@@ -139,8 +142,9 @@ H5FedGetVertexIndicesOfTriangle (
 	h5_id_t entity_id,
 	h5_id_t* vertex_indices
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_get_vertex_indices_of_triangle (f, entity_id, vertex_indices);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_get_vertex_indices_of_triangle (f, entity_id, vertex_indices);
+	H5_API_RETURN (h5err);
 }
 
 h5_err_t
@@ -149,8 +153,9 @@ H5FedGetVertexIndicesOfTet (
 	h5_id_t entity_id,
 	h5_id_t* vertex_indices
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_get_vertex_indices_of_tet (f, entity_id, vertex_indices);
+	H5_API_ENTER
+	h5_err_t h5err = h5t_get_vertex_indices_of_tet (f, entity_id, vertex_indices);
+	H5_API_RETURN (h5err);
 }
 
 h5_err_t
@@ -159,8 +164,9 @@ H5FedGetVertexIndicesOfEntity (
 	h5_id_t entity_id,
 	h5_id_t* vertex_indices
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_get_vertex_indices_of_entity (f, entity_id, vertex_indices);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_get_vertex_indices_of_entity (f, entity_id, vertex_indices);
+	H5_API_RETURN (h5err);
 }
 
 
diff --git a/src/C/H5Fed_store.c b/src/C/H5Fed_store.c
index f2c3837..e2ce45d 100644
--- a/src/C/H5Fed_store.c
+++ b/src/C/H5Fed_store.c
@@ -22,8 +22,9 @@ H5FedAddMesh (
 	h5_file_t* const f,
 	const h5_oid_t mesh_type_id
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_add_mesh (f, mesh_type_id);
+	H5_API_ENTER;
+	h5_id_t id = h5t_add_mesh (f, mesh_type_id);
+	H5_API_RETURN (id);
 }
 
 /*!
@@ -46,12 +47,13 @@ H5FedAddMesh (
   \c > 0	number of mesh levels
  
 */
-h5_id_t
+h5t_lvl_idx_t
 H5FedAddLevel (
 	h5_file_t* const f
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_add_level (f);
+	H5_API_ENTER;
+	h5t_lvl_idx_t idx = h5t_add_level (f);
+	H5_API_RETURN (idx);
 }
 
 h5_err_t
@@ -59,8 +61,9 @@ H5FedBeginStoreVertices (
 	h5_file_t* const f,
 	const h5_size_t num
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_begin_store_vertices (f, num);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_begin_store_vertices (f, num);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -72,29 +75,33 @@ H5FedBeginStoreVertices (
   \return local vertex id on success
   \return errno on error
 */
-h5_id_t
+h5_loc_idx_t
 H5FedStoreVertex (
 	h5_file_t* const f,		/*!< file handle		*/
 	const h5_id_t vertex_id,	/*!< id from mesher or -1	*/
 	const h5_float64_t P[3]		/*!< coordinates		*/
 	) {
 
-	H5_ENTER_API (f, __func__);
+	H5_API_ENTER;
+	h5_loc_idx_t idx;
 	if (h5t_get_level (f) != 0) {
-		return h5_error (
+		idx = h5_error (
 			f,
 			H5_ERR_INVAL,
 			"Vertices can be added to level 0 only!");
+		goto exit;
 	}
-	return h5t_store_vertex (f, vertex_id, P);
+	idx = h5t_store_vertex (f, vertex_id, P);
+	H5_API_RETURN (idx);
 }
 
 h5_err_t
 H5FedEndStoreVertices (
 	h5_file_t* const f
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_end_store_vertices (f);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_end_store_vertices (f);
+	H5_API_RETURN (h5err);
 }
 
 h5_err_t
@@ -102,8 +109,9 @@ H5FedBeginStoreElements (
 	h5_file_t* const f,
 	const h5_size_t num
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_begin_store_elems (f, num);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_begin_store_elems (f, num);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -120,50 +128,56 @@ H5FedBeginStoreElements (
   \return local tetrahedron id
   \return \c errno on error
 */
-h5_id_t
+h5_loc_idx_t
 H5FedStoreElement (
 	h5_file_t* const f,		/*!< file handle		*/
 	const h5_id_t local_vids[]	/*!< tuple with vertex id's	*/
 	) {
-	H5_ENTER_API (f, __func__);
+	H5_API_ENTER;
+	h5_loc_idx_t idx;
 	if (h5t_get_level (f) != 0) {
-		return h5_error (
+		idx = h5_error (
 			f,
 			H5_ERR_INVAL,
 			"Elements can be added to level 0 only!");
 	}
-	return h5t_store_elem ( f, -1, local_vids );
+	idx = h5t_store_elem ( f, -1, local_vids );
+	H5_API_RETURN (idx);
 }
 
 h5_err_t
 H5FedEndStoreElements (
 	h5_file_t* const f
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_end_store_elems (f);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_end_store_elems (f);
+	H5_API_RETURN (h5err);
 }
 
 h5_err_t
 H5FedBeginRefineElements (
 	h5_file_t* const f
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_begin_refine_elems (f);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_begin_refine_elems (f);
+	H5_API_RETURN (h5err);
 }
 
-h5_id_t
+h5_err_t
 H5FedRefineElement (
 	h5_file_t* const f,		/*!< file handle		*/
 	const h5_id_t local_eid		/*!< local element id		*/
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_mark_entity (f, local_eid);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_mark_entity (f, local_eid);
+	H5_API_RETURN (h5err);
 }
 
 h5_err_t
 H5FedEndRefineElements (
 	h5_file_t* const f
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_end_refine_elems (f);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_end_refine_elems (f);
+	H5_API_RETURN (h5err);
 }
diff --git a/src/C/H5Fed_tags.c b/src/C/H5Fed_tags.c
index 70e10b4..d6f2e93 100644
--- a/src/C/H5Fed_tags.c
+++ b/src/C/H5Fed_tags.c
@@ -1,5 +1,5 @@
 /*
-  Copyright 2007-2009
+  Copyright 2007-2011
  	Paul Scherrer Institut, Villigen, Switzerland;
  	Achim Gsell
  	All rights reserved.
@@ -29,8 +29,9 @@ H5FedAddMTagset (
 	char* name,
 	h5_id_t type
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_add_mtagset (f, name, type);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_add_mtagset (f, name, type);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -46,8 +47,9 @@ H5FedRemoveMTagset (
 	h5_file_t* const f,
 	char name[]
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_remove_mtagset (f, name );
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_remove_mtagset (f, name );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -58,13 +60,14 @@ H5FedRemoveMTagset (
 
   \return	Number of tagsets or error code
  */
-h5_size_t
+h5_ssize_t
 H5FedGetMTagsets (
 	h5_file_t* const f,
 	char** names[]
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_get_mtagsets (f, names);
+	H5_API_ENTER;
+	h5_ssize_t num = h5t_get_mtagsets (f, names);
+	H5_API_RETURN (num);
 }
 
 /*!
@@ -80,8 +83,9 @@ H5FedGetTypeOfMTagset (
 	h5_file_t* const f,
 	char name[]
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_get_mtagset_type_by_name (f, name);
+	H5_API_ENTER;
+	h5_id_t id = h5t_get_mtagset_type_by_name (f, name);
+	H5_API_RETURN (id);
 }
 
 /*!
@@ -103,8 +107,9 @@ H5FedSetMTag (
 	const size_t dims,
 	void* val 
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_set_mtag_by_name (f, name, id, dims, val);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_set_mtag_by_name (f, name, id, dims, val);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -126,8 +131,9 @@ H5FedGetMTag (
 	size_t* dim,
 	void* vals
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_get_mtag_by_name (f, name, id, dim, vals);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_get_mtag_by_name (f, name, id, dim, vals);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -143,6 +149,7 @@ H5FedRemoveMTag (
 	const char name[],
 	const h5_id_t id
 	) {
-	H5_ENTER_API (f, __func__);
-	return h5t_remove_mtag_by_name (f, name, id);
+	H5_API_ENTER;
+	h5_err_t h5err = h5t_remove_mtag_by_name (f, name, id);
+	H5_API_RETURN (h5err);
 }
diff --git a/src/C/H5Part.c b/src/C/H5Part.c
index 3069457..e2429f5 100644
--- a/src/C/H5Part.c
+++ b/src/C/H5Part.c
@@ -49,11 +49,10 @@ H5PartSetNumParticles (
 	h5_file_t *f,		/*!< [in] Handle to open file */
 	h5_size_t nparticles	/*!< [in] Number of particles */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
+	H5_API_ENTER;
 	h5_size_t stride = 1;
-	return h5u_set_num_particles( f, nparticles, stride );
+	h5_err_t h5err = h5u_set_num_particles( f, nparticles, stride );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -89,10 +88,9 @@ H5PartSetNumParticlesStrided (
 	h5_size_t nparticles,	/*!< [in] Number of particles */
 	h5_size_t stride	/*!< [in] Stride value (e.g. number of fields in the particle array) */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5u_set_num_particles( f, nparticles, stride );
+	H5_API_ENTER;
+	h5_err_t h5err = h5u_set_num_particles( f, nparticles, stride );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -113,10 +111,9 @@ H5PartSetChunk (
 	h5_file_t *f,
 	h5_size_t size
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-        return h5u_set_chunk( f, size );
+	H5_API_ENTER;
+        h5_err_t h5err = h5u_set_chunk( f, size );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -151,10 +148,9 @@ H5PartWriteDataFloat64 (
 	const char *name,	/*!< [in] Name to associate array with */
 	const h5_float64_t *data	/*!< [in] Array to commit to disk */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5u_write_data( f, name, (void*)data, H5T_NATIVE_DOUBLE );
+	H5_API_ENTER;
+	h5_err_t h5err = h5u_write_data( f, name, (void*)data, H5T_NATIVE_DOUBLE );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -189,10 +185,9 @@ H5PartWriteDataFloat32 (
 	const char *name,	/*!< [in] Name to associate array with */
 	const h5_float32_t *data	/*!< [in] Array to commit to disk */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5u_write_data( f, name, (void*)data, H5T_NATIVE_FLOAT );
+	H5_API_ENTER;
+	h5_err_t h5err = h5u_write_data( f, name, (void*)data, H5T_NATIVE_FLOAT );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -227,10 +222,9 @@ H5PartWriteDataInt64 (
 	const char *name,	/*!< [in] Name to associate array with */
 	const h5_int64_t *data	/*!< [in] Array to commit to disk */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5u_write_data ( f, name, (void*)data, H5T_NATIVE_INT64 );
+	H5_API_ENTER;
+	h5_err_t h5err = h5u_write_data ( f, name, (void*)data, H5T_NATIVE_INT64 );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -265,10 +259,9 @@ H5PartWriteDataInt32 (
 	const char *name,	/*!< [in] Name to associate array with */
 	const h5_int32_t *data	/*!< [in] Array to commit to disk */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5u_write_data ( f, name, (void*)data, H5T_NATIVE_INT32 );
+	H5_API_ENTER;
+	h5_err_t h5err = h5u_write_data ( f, name, (void*)data, H5T_NATIVE_INT32 );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -289,10 +282,9 @@ H5PartReadDataFloat64 (
 	const char *name,	/*!< [in] Name to associate dataset with */
 	h5_float64_t *data	/*!< [out] Array of data */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5u_read_data ( f, name, data, H5T_NATIVE_DOUBLE );
+	H5_API_ENTER;
+	h5_err_t h5err = h5u_read_data ( f, name, data, H5T_NATIVE_DOUBLE );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -313,10 +305,9 @@ H5PartReadDataFloat32 (
 	const char *name,	/*!< [in] Name to associate dataset with */
 	h5_float32_t *data	/*!< [out] Array of data */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5u_read_data ( f, name, data, H5T_NATIVE_FLOAT );
+	H5_API_ENTER;
+	h5_err_t h5err = h5u_read_data ( f, name, data, H5T_NATIVE_FLOAT );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -337,10 +328,9 @@ H5PartReadDataInt64 (
 	const char *name,	/*!< [in] Name to associate dataset with */
 	h5_int64_t *data	/*!< [out] Array of data */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5u_read_data ( f, name, data, H5T_NATIVE_INT64 );
+	H5_API_ENTER;
+	h5_err_t h5err = h5u_read_data ( f, name, data, H5T_NATIVE_INT64 );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -361,10 +351,9 @@ H5PartReadDataInt32 (
 	const char *name,	/*!< [in] Name to associate dataset with */
 	h5_int32_t *data	/*!< [out] Array of data */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5u_read_data ( f, name, data, H5T_NATIVE_INT32 );
+	H5_API_ENTER;
+	h5_err_t h5err = h5u_read_data ( f, name, data, H5T_NATIVE_INT32 );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -379,10 +368,9 @@ h5_ssize_t
 H5PartGetNumDatasets (
 	h5_file_t *f			/*!< [in]  Handle to open file */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5u_get_num_datasets(f);
+	H5_API_ENTER;
+	h5_err_t h5err = h5u_get_num_datasets(f);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -402,10 +390,9 @@ H5PartGetDatasetName (
 	char *name,		/*!< [out] Name of dataset */
 	const h5_size_t len	/*!< [in]  Size of buffer \c name */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5u_get_dataset_info(f, idx, name, len, NULL, NULL);
+	H5_API_ENTER;
+	h5_err_t h5err = h5u_get_dataset_info(f, idx, name, len, NULL, NULL);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -433,10 +420,9 @@ H5PartGetDatasetInfo (
 	h5_int64_t *type,	/*!< [out] Type of data in dataset */
 	h5_size_t *nelem	/*!< [out] Number of elements. */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5u_get_dataset_info(f, idx, dataset_name, len_dataset_name, type, nelem);
+	H5_API_ENTER;
+	h5_err_t h5err = h5u_get_dataset_info(f, idx, dataset_name, len_dataset_name, type, nelem);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -464,12 +450,10 @@ h5_ssize_t
 H5PartGetNumParticles (
 	h5_file_t *f			/*!< [in]  Handle to open file */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
+	H5_API_ENTER;
 	CHECK_FILEHANDLE( f );
-
-	return h5u_get_num_particles( f );
+	h5_ssize_t nparticels = h5u_get_num_particles( f );
+	H5_API_RETURN (nparticels);
 }
 
 /*!
@@ -483,10 +467,9 @@ h5_err_t
 H5PartResetView (
  	h5_file_t *f			/*!< [in]  Handle to open file */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5u_reset_view ( f );
+	H5_API_ENTER;
+	h5_err_t h5err = h5u_reset_view ( f );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -502,10 +485,9 @@ h5_err_t
 H5PartHasView (
  	h5_file_t *f			/*!< [in]  Handle to open file */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5u_has_view ( f );
+	H5_API_ENTER;
+	h5_err_t h5err = h5u_has_view ( f );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -535,10 +517,9 @@ H5PartSetView (
 	h5_int64_t start,	/*!< [in]  Start particle */
 	h5_int64_t end	/*!< [in]  End particle */
 	) {
-
-	H5_ENTER_API( f, __func__ );
- 
-	return h5u_set_view ( f, start, end );
+	H5_API_ENTER;
+ 	h5_err_t h5err = h5u_set_view ( f, start, end );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -565,10 +546,9 @@ H5PartSetViewIndices (
 	const h5_id_t *indices,		/*!< [in]  List of indices */
 	h5_size_t nelems		/*!< [in]  Size of list */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5u_set_view_indices ( f, indices, nelems );
+	H5_API_ENTER;
+	h5_err_t h5err = h5u_set_view_indices ( f, indices, nelems );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -587,10 +567,9 @@ H5PartGetView (
 	h5_int64_t *start,		/*!< [out]  Start particle */
 	h5_int64_t *end			/*!< [out]  End particle */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5u_get_view( f, start, end );
+	H5_API_ENTER;
+	h5_err_t h5err = h5u_get_view( f, start, end );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -607,9 +586,8 @@ h5_err_t
 H5PartSetCanonicalView (
 	h5_file_t *f			/*!< [in]  Handle to open file */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5u_set_canonical_view( f );
+	H5_API_ENTER;
+	h5_err_t h5err = h5u_set_canonical_view( f );
+	H5_API_RETURN (h5err);
 }
 
diff --git a/src/C/H5_attribs.c b/src/C/H5_attribs.c
index c75680b..c76ac08 100644
--- a/src/C/H5_attribs.c
+++ b/src/C/H5_attribs.c
@@ -20,16 +20,15 @@ H5WriteFileAttribString (
 	const char *name,	/*!< [in] Name of attribute to create */
 	const char *value	/*!< [in] Value of attribute */ 
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_write_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_write_attrib (
 		f,
 		H5_ATTRIB_FILE,
 		name,
 		H5T_NATIVE_CHAR,
 		value,
 		strlen(value) + 1 );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -46,16 +45,15 @@ H5WriteStepAttribString (
 	const char *name,	/*!< [in] Name of attribute to create */
 	const char *value	/*!< [in] Value of attribute */ 
 	) {
-
-	H5_ENTER_API ( f, __func__ );
-
-	return h5_write_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_write_attrib (
 		f, 
 		H5_ATTRIB_STEP,
 		name,
 		H5T_NATIVE_CHAR,
 		value,
 		strlen(value) + 1 );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -73,16 +71,15 @@ H5WriteFileAttribFloat32 (
 	const h5_float32_t *values,	/*!< [in] Values of attribute */
 	const h5_size_t nelems		/*!< [in] Number of values */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_write_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_write_attrib (
 		f,
 		H5_ATTRIB_FILE,
 		name,
 		H5T_NATIVE_FLOAT,
 		values,
 		nelems );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -100,16 +97,15 @@ H5WriteStepAttribFloat32 (
 	const h5_float32_t *values,	/*!< [in] Values of attribute */
 	const h5_size_t nelems		/*!< [in] Number of values */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_write_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_write_attrib (
 		f,
 		H5_ATTRIB_STEP,
 		name,
 		H5T_NATIVE_FLOAT,
 		values,
 		nelems );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -127,16 +123,15 @@ H5WriteFileAttribFloat64 (
 	const h5_float64_t *values,	/*!< [in] Values of attribute */
 	const h5_size_t nelems		/*!< [in] Number of values */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_write_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_write_attrib (
 		f,
 		H5_ATTRIB_FILE,
 		name,
 		H5T_NATIVE_DOUBLE,
 		values,
 		nelems );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -154,16 +149,15 @@ H5WriteStepAttribFloat64 (
 	const h5_float64_t *values,	/*!< [in] Values of attribute */
 	const h5_size_t nelems		/*!< [in] Number of values */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_write_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_write_attrib (
 		f,
 		H5_ATTRIB_STEP,
 		name,
 		H5T_NATIVE_DOUBLE,
 		values,
 		nelems );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -181,16 +175,15 @@ H5WriteFileAttribInt32 (
 	const h5_int32_t *values,	/*!< [in] Values of attribute */
 	const h5_size_t nelems		/*!< [in] Number of values */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_write_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_write_attrib (
 		f,
 		H5_ATTRIB_FILE,
 		name,
 		H5T_NATIVE_INT32,
 		values,
 		nelems );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -208,16 +201,15 @@ H5WriteStepAttribInt32 (
 	const h5_int32_t *values,	/*!< [in] Values of attribute */
 	const h5_size_t nelems		/*!< [in] Number of values */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_write_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_write_attrib (
 		f,
 		H5_ATTRIB_STEP,
 		name,
 		H5T_NATIVE_INT32,
 		values,
 		nelems );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -235,16 +227,15 @@ H5WriteFileAttribInt64 (
 	const h5_int64_t *values,	/*!< [in] Values of attribute */
 	const h5_size_t nelems		/*!< [in] Number of values */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_write_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_write_attrib (
 		f,
 		H5_ATTRIB_FILE,
 		name,
 		H5T_NATIVE_INT64,
 		values,
 		nelems );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -262,16 +253,15 @@ H5WriteStepAttribInt64 (
 	const h5_int64_t *values,	/*!< [in] Values of attribute */
 	const h5_size_t nelems		/*!< [in] Number of values */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_write_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_write_attrib (
 		f,
 		H5_ATTRIB_STEP,
 		name,
 		H5T_NATIVE_INT64,
 		values,
 		nelems );
+	H5_API_RETURN (h5err);
 }
 
 /*** READ ***/
@@ -290,15 +280,14 @@ H5ReadFileAttribString (
 	const char *name,	/*!< [in] Name of attribute to create */
 	char *buffer		/*!< [out] Value of attribute */ 
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_read_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_read_attrib (
 		f,
 		H5_ATTRIB_FILE,
 		name,
 		H5_STRING_T,
 		(void*)buffer);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -315,15 +304,14 @@ H5ReadStepAttribString (
 	const char *name,	/*!< [in] Name of attribute to create */
 	char *buffer		/*!< [out] Value of attribute */ 
 	) {
-
-	H5_ENTER_API ( f, __func__ );
-
-	return h5_read_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_read_attrib (
 		f, 
 		H5_ATTRIB_STEP,
 		name,
 		H5_STRING_T,
 		(void*)buffer);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -340,15 +328,14 @@ H5ReadFileAttribInt32 (
 	const char *name,		/*!< [in] Name of attribute to create */
 	h5_int32_t *buffer		/*!< [out] Values of attribute */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_read_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_read_attrib (
 		f,
 		H5_ATTRIB_FILE,
 		name,
 		H5_INT32_T,
 		(void*)buffer);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -365,15 +352,14 @@ H5ReadStepAttribInt32 (
 	const char *name,		/*!< [in] Name of attribute to create */
 	h5_int32_t *buffer		/*!< [out] Values of attribute */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_read_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_read_attrib (
 		f,
 		H5_ATTRIB_STEP,
 		name,
 		H5_INT32_T,
 		(void*)buffer);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -390,15 +376,14 @@ H5ReadFileAttribInt64 (
 	const char *name,		/*!< [in] Name of attribute to create */
 	h5_int64_t *buffer		/*!< [out] Values of attribute */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_read_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_read_attrib (
 		f,
 		H5_ATTRIB_FILE,
 		name,
 		H5_INT64_T,
 		(void*)buffer);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -415,15 +400,14 @@ H5ReadStepAttribInt64 (
 	const char *name,		/*!< [in] Name of attribute to create */
 	h5_int64_t *buffer		/*!< [out] Values of attribute */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_read_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_read_attrib (
 		f,
 		H5_ATTRIB_STEP,
 		name,
 		H5_INT64_T,
 		(void*)buffer);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -440,15 +424,14 @@ H5ReadFileAttribFloat32 (
 	const char *name,		/*!< [in] Name of attribute to create */
 	h5_float32_t *buffer		/*!< [out] Values of attribute */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_read_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_read_attrib (
 		f,
 		H5_ATTRIB_FILE,
 		name,
 		H5_FLOAT32_T,
 		(void*)buffer);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -465,15 +448,14 @@ H5ReadStepAttribFloat32 (
 	const char *name,		/*!< [in] Name of attribute to create */
 	h5_float32_t *buffer		/*!< [out] Values of attribute */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_read_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_read_attrib (
 		f,
 		H5_ATTRIB_STEP,
 		name,
 		H5_FLOAT32_T,
 		(void*)buffer);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -490,15 +472,14 @@ H5ReadFileAttribFloat64 (
 	const char *name,		/*!< [in] Name of attribute to create */
 	h5_float64_t *buffer		/*!< [out] Values of attribute */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_read_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_read_attrib (
 		f,
 		H5_ATTRIB_FILE,
 		name,
 		H5_FLOAT64_T,
 		(void*)buffer);
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -515,15 +496,14 @@ H5ReadStepAttribFloat64 (
 	const char *name,		/*!< [in] Name of attribute to create */
 	h5_float64_t *buffer		/*!< [out] Values of attribute */
 	) {
-
-	H5_ENTER_API( f, __func__ );
-
-	return h5_read_attrib (
+	H5_API_ENTER;
+	h5_err_t h5err = h5_read_attrib (
 		f,
 		H5_ATTRIB_STEP,
 		name,
 		H5_FLOAT64_T,
 		(void*)buffer);
+	H5_API_RETURN (h5err);
 }
 
 /*** QUERY ***/
@@ -539,9 +519,9 @@ h5_int64_t
 H5GetNumFileAttribs (
 	h5_file_t *const f	/*!< [in] Handle to open file */
 	) {
-	H5_ENTER_API( f, __func__ );
-
-	return h5_get_num_attribs ( f, H5_ATTRIB_FILE );
+	H5_API_ENTER;
+	h5_int64_t nattribs = h5_get_num_attribs ( f, H5_ATTRIB_FILE );
+	H5_API_RETURN (nattribs);
 }
 
 /*!
@@ -549,15 +529,15 @@ H5GetNumFileAttribs (
 
   Gets the number of attributes bound to the current step.
 
-  \return	Number of attributes or error code.
+  \h5_err_t h5err =	Number of attributes or error code.
 */
 h5_int64_t
 H5GetNumStepAttribs (
 	h5_file_t *const f 	/*!< [in] Handle to open file */
 	) {
-	H5_ENTER_API( f, __func__ );
-
-	return h5_get_num_attribs ( f, H5_ATTRIB_STEP );
+	H5_API_ENTER;
+	h5_int64_t nattribs = h5_get_num_attribs ( f, H5_ATTRIB_STEP );
+	H5_API_RETURN (nattribs);
 }
 
 
@@ -586,13 +566,8 @@ H5GetFileAttribInfo (
 	h5_int64_t *attrib_type,	/*!< [out] Type of value. */
 	h5_size_t *attrib_nelem         /*!< [out] Number of elements */
 	) {
-
-	H5_ENTER_API ( f, __func__ );
-
-	if ( h5_check_filehandle ( f ) != H5_SUCCESS )
-		return h5_get_errno ( f );
-
-	return h5_get_attrib_info (
+	H5_API_ENTER;
+	h5_int64_t h5err = h5_get_attrib_info (
 		f,
 		H5_ATTRIB_FILE,
 		attrib_idx,
@@ -600,6 +575,7 @@ H5GetFileAttribInfo (
 		len_of_attrib_name,
 		attrib_type,
 		attrib_nelem );
+	H5_API_RETURN (h5err);
 }
 
 /*!
@@ -626,13 +602,8 @@ H5GetStepAttribInfo (
 	h5_int64_t *attrib_type,	/*!< [out] Type of value. */
 	h5_size_t *attrib_nelem         /*!< [out] Number of elements */
 	) {
-	
-	H5_ENTER_API ( f, __func__ );
-
-   	if ( h5_check_filehandle ( f ) != H5_SUCCESS )
-		return h5_get_errno( f );
-
-	return h5_get_attrib_info (
+	H5_API_ENTER;
+	h5_int64_t h5err = h5_get_attrib_info (
 		f,
 		H5_ATTRIB_STEP,
 		attrib_idx,
@@ -640,5 +611,6 @@ H5GetStepAttribInfo (
 		len_of_attrib_name,
 		attrib_type,
 		attrib_nelem );
+	H5_API_RETURN (h5err);
 }
 
diff --git a/src/h5core/Makefile.am b/src/h5core/Makefile.am
index af60f1d..9233d8b 100644
--- a/src/h5core/Makefile.am
+++ b/src/h5core/Makefile.am
@@ -14,6 +14,7 @@ EXTRA_HEADERS =					\
 	../include/h5core/h5_maps.h		\
 	../include/h5core/h5_openclose.h	\
 	../include/h5core/h5_readwrite.h	\
+	../include/h5core/h5_syscall.h		\
 	../include/h5core/h5_types.h		\
 	../include/h5core/h5u_readwrite.h	\
 	../include/h5core/h5b_readwrite.h	\
diff --git a/src/h5core/h5_core_private.h b/src/h5core/h5_core_private.h
index 7f46180..b750fbb 100644
--- a/src/h5core/h5_core_private.h
+++ b/src/h5core/h5_core_private.h
@@ -1,6 +1,16 @@
 #ifndef __H5_CORE_PRIVATE_H
 #define __H5_CORE_PRIVATE_H
 
+#define H5_CORE_API_ENTER {			\
+		h5_debug (f, "%s", " ");	\
+	}					\
+
+#define H5_CORE_API_RETURN(retval)		\
+						\
+	goto exit;				\
+	exit:					\
+	return (retval);	       		\
+
 /* WARNING! Changing these values will alter the data model and introduce
  * file incompatibilities with previous versions. */
 #define H5_DATANAME_LEN		64
@@ -38,9 +48,6 @@
 #include "h5u_errorhandling_private.h"
 #include "h5u_types_private.h"
 
-#define TRY( func )						\
-	if ((int64_t)(ptrdiff_t)(func) <= (int64_t)H5_ERR)	\
-		return H5_ERR;
 
 #ifdef IPL_XT3
 # define SEEK_END 2 
diff --git a/src/h5core/h5_syscall_private.h b/src/h5core/h5_syscall_private.h
index 686988f..9e6bb59 100644
--- a/src/h5core/h5_syscall_private.h
+++ b/src/h5core/h5_syscall_private.h
@@ -1,25 +1,5 @@
-#ifndef __H5_SYSCALL_H
-#define __H5_SYSCALL_H
-
-void*
-h5_alloc (
-	h5_file_t* const f,
-	void* ptr,
-	const size_t size
-	);
-
-void*
-h5_calloc (
-	h5_file_t* const f,
-	const size_t count,
-	const size_t size
-	);
-
-h5_err_t
-h5_free (
-	h5_file_t* const f,
-	void* ptr
-	);
+#ifndef __H5_SYSCALL_PRIVATE_H
+#define __H5_SYSCALL_PRIVATE_H
 
 char*
 h5priv_strdup (
diff --git a/src/h5core/h5t_retrieve.c b/src/h5core/h5t_retrieve.c
index b524f25..80e301e 100644
--- a/src/h5core/h5t_retrieve.c
+++ b/src/h5core/h5t_retrieve.c
@@ -194,6 +194,8 @@ h5t_init_leaf_iterator (
 	h5t_iterator_t* iter,
 	int codim
 	) {
+	H5_CORE_API_ENTER;
+	h5_err_t h5err = H5_SUCCESS;
 	h5t_leaf_iterator_t* it = (h5t_leaf_iterator_t*)&iter->leaf;
 	it->face_idx = 999;
 	it->elem_idx = -1;
@@ -206,30 +208,18 @@ h5t_init_leaf_iterator (
 	} else if (it->codim == 0) {
 		it->iter = iterate_leaf_elems;
 	}
-	return H5_SUCCESS;
+	H5_CORE_API_RETURN (h5err);
 }
 
 h5_err_t
-h5t_create_leaf_iterator (
+h5t_init_boundary_face_iterator (
 	h5_file_t* f,
-	h5t_iterator_t** iter,
+	h5t_iterator_t* iter,
 	int codim
 	) {
+	H5_CORE_API_ENTER;
+	h5_err_t h5err = H5_SUCCESS;
 	h5t_leaf_iterator_t* it;
-	TRY( it = h5_calloc (f, 1, sizeof (h5t_leaf_iterator_t)) );
-	TRY( h5t_init_leaf_iterator (f, (h5t_iterator_t*)it, codim) );
-	*iter =  (h5t_iterator_t*)it;
-	return H5_SUCCESS;
-}
-
-h5_err_t
-h5t_create_boundary_face_iterator (
-	h5_file_t* f,
-	h5t_iterator_t** iter,
-	int codim
-	) {
-	h5t_leaf_iterator_t* it;
-	TRY( it = h5_calloc (f, 1, sizeof (h5t_leaf_iterator_t)) );
 	it->face_idx = 999; // just a high enough number
 	it->elem_idx = -1;
 	it->codim = codim;
@@ -244,25 +234,25 @@ h5t_create_boundary_face_iterator (
 	else if (it->codim > 1) {
 		it->iter = iterate_boundary_faces;
 	}
-	*iter =  (h5t_iterator_t*)it;
-	return H5_SUCCESS;
+	H5_CORE_API_RETURN (h5err);
 }
 
 h5_err_t
-h5t_create_mtag_iterator (
+h5t_init_mtag_iterator (
 	h5_file_t* f,
-	h5t_iterator_t** iter,
+	h5t_iterator_t* iter,
 	const char* name
 	) {
-	h5t_tag_iterator_t* it;
-	TRY( it = h5_calloc (f, 1, sizeof (*it)) );
-	h5t_open_mtagset (f, name, &it->tagset);
+	H5_CORE_API_ENTER;
+	h5_err_t h5err = H5_SUCCESS;
+	h5t_tag_iterator_t* it = (h5t_tag_iterator_t*)iter;
+	TRY2( h5err = h5t_open_mtagset (f, name, &it->tagset) );
 	it->elem_idx = -1;
 	it->subentity_idx = 999;
 	it->level_idx = f->t->cur_level;
 	it->iter = iterate_tags;
-	*iter =  (h5t_iterator_t*)it;
-	return H5_SUCCESS;
+	h5err = H5_SUCCESS;
+	H5_CORE_API_RETURN (h5err);
 }
 
 h5_err_t
@@ -270,7 +260,9 @@ h5t_release_entity_iterator (
 	h5_file_t* const f,
 	h5t_iterator_t* iter
 	) {
-	return h5_free (f, iter);
+	H5_CORE_API_ENTER;
+	h5_err_t h5err = h5_free (f, iter);
+	H5_CORE_API_RETURN (h5err);
 }
 
 h5_loc_id_t
@@ -278,8 +270,10 @@ h5t_iterate_entities (
 	h5_file_t* const f,
 	h5t_iterator_t* iter
 	) {
+	H5_CORE_API_ENTER;
 	h5t_generic_iterator_t* it = (h5t_generic_iterator_t*)iter;
-	return (it->iter (f, iter));
+	h5_err_t h5err = it->iter (f, iter);
+	H5_CORE_API_RETURN (h5err);
 }
 		   
 h5_err_t
@@ -288,12 +282,14 @@ h5t_end_iterate_entities (
 	h5t_iterator_t* iter
 	) {
 	UNUSED_ARGUMENT (f);
+	H5_CORE_API_ENTER;
+	h5_err_t h5err = H5_SUCCESS;
 	bzero (iter, sizeof(*iter));
-	h5t_leaf_iterator_t* it = (h5t_leaf_iterator_t*)&iter->leaf;
+	h5t_leaf_iterator_t* it = (h5t_leaf_iterator_t*)iter;
 	it->face_idx = -1;
 	it->elem_idx = -1;
 	it->codim = -1;
-	return H5_SUCCESS;
+	H5_CORE_API_RETURN (h5err);
 }
 
 h5_err_t
@@ -302,9 +298,11 @@ h5t_get_vertex_coords_by_index (
 	h5_loc_idx_t vertex_index,
 	h5_float64_t P[3]
 	) {
+	H5_CORE_API_ENTER;
+	h5_err_t h5err = H5_SUCCESS;
 	h5_loc_vertex_t *vertex = &f->t->vertices[vertex_index];
 	memcpy ( P, &vertex->P, sizeof ( vertex->P ) );
-	return H5_SUCCESS;
+	H5_CORE_API_RETURN (h5err);
 }
 
 h5_err_t
@@ -313,9 +311,11 @@ h5t_get_vertex_coords_by_id (
 	h5_loc_id_t vertex_id,
 	h5_float64_t P[3]
 	) {
+	H5_CORE_API_ENTER;
+	h5_err_t h5err = H5_SUCCESS;
 	h5_loc_idx_t vertex_index;
-	h5t_get_vertex_index_of_vertex (f, vertex_id, &vertex_index );
-	h5t_get_vertex_coords_by_index (f, vertex_index, P);
-	return H5_SUCCESS;
+	TRY2( h5err = h5t_get_vertex_index_of_vertex (f, vertex_id, &vertex_index) );
+	TRY2( h5t_get_vertex_coords_by_index (f, vertex_index, P) );
+	H5_CORE_API_RETURN (h5err);
 }
 
diff --git a/src/include/H5Fed_inquiry.h b/src/include/H5Fed_inquiry.h
index da14385..e97ce5d 100644
--- a/src/include/H5Fed_inquiry.h
+++ b/src/include/H5Fed_inquiry.h
@@ -18,13 +18,13 @@
 #ifndef __H5FED_INQUIRY_H
 #define __H5FED_INQUIRY_H
 
-h5_size_t H5FedGetNumMeshes ( h5_file_t * const f, const h5_oid_t type_id );
-h5_size_t H5FedGetNumLevels ( h5_file_t * const f );
-h5_id_t H5FedGetLevel ( h5_file_t * const f );
-h5_size_t H5FedGetNumVertices ( h5_file_t * const f );
-h5_size_t H5FedGetNumVerticesCnode ( h5_file_t * const f, const h5_id_t cnode );
-h5_size_t H5FedGetNumVerticesTotal ( h5_file_t * const f );
-h5_size_t H5FedGetNumElements ( h5_file_t * const f );
-h5_size_t H5FedGetNumElementsCnode ( h5_file_t * const f, const h5_id_t cnode );
-h5_size_t H5FedGetNumElementsTotal ( h5_file_t * const f );
+h5_ssize_t H5FedGetNumMeshes ( h5_file_t * const f, const h5_oid_t type_id );
+h5_ssize_t H5FedGetNumLevels ( h5_file_t * const f );
+h5t_lvl_idx_t H5FedGetLevel ( h5_file_t * const f );
+h5_ssize_t H5FedGetNumVertices ( h5_file_t * const f );
+h5_ssize_t H5FedGetNumVerticesCnode ( h5_file_t * const f, const h5_id_t cnode );
+h5_ssize_t H5FedGetNumVerticesTotal ( h5_file_t * const f );
+h5_ssize_t H5FedGetNumElements ( h5_file_t * const f );
+h5_ssize_t H5FedGetNumElementsCnode ( h5_file_t * const f, const h5_id_t cnode );
+h5_ssize_t H5FedGetNumElementsTotal ( h5_file_t * const f );
 #endif
diff --git a/src/include/H5Fed_store.h b/src/include/H5Fed_store.h
index 21b2c96..cd4b534 100644
--- a/src/include/H5Fed_store.h
+++ b/src/include/H5Fed_store.h
@@ -25,7 +25,7 @@ H5FedAddMesh (
 	const h5_oid_t mesh_type_id
 	);
 
-h5_id_t
+h5t_lvl_idx_t
 H5FedAddLevel (
 	h5_file_t * const f
 	);
diff --git a/src/include/H5Fed_tags.h b/src/include/H5Fed_tags.h
index 7f502dd..81e9653 100644
--- a/src/include/H5Fed_tags.h
+++ b/src/include/H5Fed_tags.h
@@ -11,7 +11,7 @@ H5FedRemoveMTagset (
 	h5_file_t* const f,
 	char name[]
 	);
-h5_size_t
+h5_ssize_t
 H5FedGetMTagsets (
 	h5_file_t* const f,
 	char** names[]
diff --git a/src/include/h5core/h5_core.h b/src/include/h5core/h5_core.h
index 477a016..8cd8d9c 100644
--- a/src/include/h5core/h5_core.h
+++ b/src/include/h5core/h5_core.h
@@ -3,6 +3,15 @@
 
 #define UNUSED_ARGUMENT(x) (void)x
 
+#define TRY( func )						\
+	if ((int64_t)(ptrdiff_t)(func) <= (int64_t)H5_ERR)	\
+		return H5_ERR;					\
+
+#define TRY2( func )						\
+	if ((int64_t)(ptrdiff_t)(func) <= (int64_t)H5_ERR)	\
+		goto exit;					\
+
+
 #include "h5_types.h"
 #include "h5_errno.h"
 
@@ -11,6 +20,7 @@
 #include "h5_maps.h"
 #include "h5_openclose.h"
 #include "h5_readwrite.h"
+#include "h5_syscall.h"
 
 #include "h5u_readwrite.h"
 #include "h5u_model.h"
diff --git a/src/include/h5core/h5_errorhandling.h b/src/include/h5core/h5_errorhandling.h
index 8161b31..996382c 100644
--- a/src/include/h5core/h5_errorhandling.h
+++ b/src/include/h5core/h5_errorhandling.h
@@ -225,13 +225,15 @@ h5_set_funcname (
 	const char  * const fname
 	);
 
-static inline void
-H5_ENTER_API (
-	h5_file_t* const f,
-	const char* const fname
-	) {
-	h5_set_funcname( f, fname );
-	h5_debug (f, "%s", " "); // just print the function name
-}
+#define H5_API_ENTER {						\
+		h5_set_funcname( f, __func__ );			\
+		h5_debug (f, "%s", " ");			\
+	}							\
+
+#define H5_API_RETURN(retval)			\
+			     			\
+	goto exit;				\
+	exit:					\
+	return retval;				\
 
 #endif
diff --git a/src/include/h5core/h5_syscall.h b/src/include/h5core/h5_syscall.h
new file mode 100644
index 0000000..301d059
--- /dev/null
+++ b/src/include/h5core/h5_syscall.h
@@ -0,0 +1,23 @@
+#ifndef __H5_SYSCALL_H
+#define __H5_SYSCALL_H
+
+void*
+h5_alloc (
+	h5_file_t* const f,
+	void* ptr,
+	const size_t size
+	);
+
+void*
+h5_calloc (
+	h5_file_t* const f,
+	const size_t count,
+	const size_t size
+	);
+
+h5_err_t
+h5_free (
+	h5_file_t* const f,
+	void* ptr
+	);
+#endif
diff --git a/src/include/h5core/h5t_retrieve.h b/src/include/h5core/h5t_retrieve.h
index 45a9f85..278403f 100644
--- a/src/include/h5core/h5t_retrieve.h
+++ b/src/include/h5core/h5t_retrieve.h
@@ -54,16 +54,9 @@ h5t_init_leaf_iterator (
 	);
 
 h5_err_t
-h5t_create_leaf_iterator (
+h5t_init_boundary_face_iterator (
 	h5_file_t* f,
-	h5t_iterator_t** iter,
-	const int codim
-	);
-
-h5_err_t
-h5t_create_boundary_face_iterator (
-	h5_file_t* f,
-	h5t_iterator_t** iter,
+	h5t_iterator_t* iter,
 	const int codim
 	);