[svn-r27045] Renamed H5_ASSIGN_OVERFLOW() to H5_CHECKED_ASSIGN() and re-ordered

the arguments to be in a more logical order.

Tested on: h5committest

51 files changed, 171 insertions, 150 deletions

diff --git a/src/H5Adense.c b/src/H5Adense.c
index 0b73a20..e0499f5 100644
--- a/src/H5Adense.c
+++ b/src/H5Adense.c
@@ -538,7 +538,7 @@ H5A_dense_insert(H5F_t *f, hid_t dxpl_id, const H5O_ainfo_t *ainfo, H5A_t *attr)
     udata.common.shared_fheap = shared_fheap;
     udata.common.name = attr->shared->name;
     udata.common.name_hash = H5_checksum_lookup3(attr->shared->name, HDstrlen(attr->shared->name), 0);
-    H5_ASSIGN_OVERFLOW(udata.common.flags, mesg_flags, unsigned, uint8_t);
+    H5_CHECKED_ASSIGN(udata.common.flags, uint8_t, mesg_flags, unsigned);
     udata.common.corder = attr->shared->crt_idx;
     udata.common.found_op = NULL;
     udata.common.found_op_data = NULL;
diff --git a/src/H5Aint.c b/src/H5Aint.c
index e28c2cc..bfc8eaf 100644
--- a/src/H5Aint.c
+++ b/src/H5Aint.c
@@ -255,7 +255,7 @@ H5A_create(const H5G_loc_t *loc, const char *name, const H5T_t *type,
     /* Get # of elements for attribute's dataspace */
     if((snelmts = H5S_GET_EXTENT_NPOINTS(attr->shared->ds)) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTCOUNT, NULL, "dataspace is invalid")
-    H5_ASSIGN_OVERFLOW(nelmts, snelmts, hssize_t, size_t);
+    H5_CHECKED_ASSIGN(nelmts, size_t, snelmts, hssize_t);
 
     HDassert(attr->shared->dt_size > 0);
     HDassert(attr->shared->ds_size > 0);
@@ -508,7 +508,7 @@ H5A_write(H5A_t *attr, const H5T_t *mem_type, const void *buf, hid_t dxpl_id)
     /* Get # of elements for attribute's dataspace */
     if((snelmts = H5S_GET_EXTENT_NPOINTS(attr->shared->ds)) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTCOUNT, FAIL, "dataspace is invalid")
-    H5_ASSIGN_OVERFLOW(nelmts, snelmts, hssize_t, size_t);
+    H5_CHECKED_ASSIGN(nelmts, size_t, snelmts, hssize_t);
 
     /* If there's actually data elements for the attribute, make a copy of the data passed in */
     if(nelmts > 0) {
@@ -621,7 +621,7 @@ H5A_read(const H5A_t *attr, const H5T_t *mem_type, void *buf, hid_t dxpl_id)
     /* Create buffer for data to store on disk */
     if((snelmts = H5S_GET_EXTENT_NPOINTS(attr->shared->ds)) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTCOUNT, FAIL, "dataspace is invalid")
-    H5_ASSIGN_OVERFLOW(nelmts, snelmts, hssize_t, size_t);
+    H5_CHECKED_ASSIGN(nelmts, size_t, snelmts, hssize_t);
 
     if(nelmts > 0) {
         /* Get the memory and file datatype sizes */
@@ -1680,7 +1680,7 @@ H5A_attr_iterate_table(const H5A_attr_table_t *atable, hsize_t skip,
         *last_attr = skip;
 
     /* Iterate over attribute messages */
-    H5_ASSIGN_OVERFLOW(/* To: */ u, /* From: */ skip, /* From: */ hsize_t, /* To: */ size_t)
+    H5_CHECKED_ASSIGN(u, size_t, skip, hsize_t)
     for(; u < atable->nattrs && !ret_value; u++) {
         /* Check which type of callback to make */
         switch(attr_op->op_type) {
@@ -2012,7 +2012,11 @@ H5A_attr_copy_file(const H5A_t *attr_src, H5F_t *file_dst, hbool_t *recompute_si
         *recompute_size = TRUE;
 
     /* Compute the size of the data */
-    H5_ASSIGN_OVERFLOW(attr_dst->shared->data_size, H5S_GET_EXTENT_NPOINTS(attr_dst->shared->ds) * H5T_get_size(attr_dst->shared->dt), hssize_t, size_t);
+    /* NOTE: This raises warnings. If we are going to be serious about
+     * expecting overflow here, we should implement testing similar to
+     * that described in CERT bulletins INT30-C and INT32-C.
+     */
+    H5_CHECKED_ASSIGN(attr_dst->shared->data_size, size_t, H5S_GET_EXTENT_NPOINTS(attr_dst->shared->ds) * H5T_get_size(attr_dst->shared->dt), hssize_t);
 
     /* Copy (& convert) the data, if necessary */
     if(attr_src->shared->data) {
diff --git a/src/H5B2hdr.c b/src/H5B2hdr.c
index 452a35d..d28c263 100644
--- a/src/H5B2hdr.c
+++ b/src/H5B2hdr.c
@@ -160,7 +160,7 @@ HDmemset(hdr->page, 0, hdr->node_size);
 
     /* Initialize leaf node info */
     sz_max_nrec = H5B2_NUM_LEAF_REC(hdr->node_size, hdr->rrec_size);
-    H5_ASSIGN_OVERFLOW(/* To: */ hdr->node_info[0].max_nrec, /* From: */ sz_max_nrec, /* From: */ size_t, /* To: */ unsigned)
+    H5_CHECKED_ASSIGN(hdr->node_info[0].max_nrec, unsigned, sz_max_nrec, size_t)
     hdr->node_info[0].split_nrec = (hdr->node_info[0].max_nrec * hdr->split_percent) / 100;
     hdr->node_info[0].merge_nrec = (hdr->node_info[0].max_nrec * hdr->merge_percent) / 100;
     hdr->node_info[0].cum_max_nrec = hdr->node_info[0].max_nrec;
@@ -182,14 +182,14 @@ HDmemset(hdr->page, 0, hdr->node_size);
     /* Compute size to store # of records in each node */
     /* (uses leaf # of records because its the largest) */
     u_max_nrec_size = H5VM_limit_enc_size((uint64_t)hdr->node_info[0].max_nrec);
-    H5_ASSIGN_OVERFLOW(/* To: */ hdr->max_nrec_size, /* From: */ u_max_nrec_size, /* From: */ unsigned, /* To: */ uint8_t)
+    H5_CHECKED_ASSIGN(hdr->max_nrec_size, uint8_t, u_max_nrec_size, unsigned)
     HDassert(hdr->max_nrec_size <= H5B2_SIZEOF_RECORDS_PER_NODE);
 
     /* Initialize internal node info */
     if(depth > 0) {
         for(u = 1; u < (unsigned)(depth + 1); u++) {
             sz_max_nrec = H5B2_NUM_INT_REC(hdr, u);
-            H5_ASSIGN_OVERFLOW(/* To: */ hdr->node_info[u].max_nrec, /* From: */ sz_max_nrec, /* From: */ size_t, /* To: */ unsigned)
+            H5_CHECKED_ASSIGN(hdr->node_info[u].max_nrec, unsigned, sz_max_nrec, size_t)
             HDassert(hdr->node_info[u].max_nrec <= hdr->node_info[u - 1].max_nrec);
 
             hdr->node_info[u].split_nrec = (hdr->node_info[u].max_nrec * hdr->split_percent) / 100;
@@ -198,7 +198,7 @@ HDmemset(hdr->page, 0, hdr->node_size);
             hdr->node_info[u].cum_max_nrec = ((hdr->node_info[u].max_nrec + 1) *
                 hdr->node_info[u - 1].cum_max_nrec) + hdr->node_info[u].max_nrec;
             u_max_nrec_size = H5VM_limit_enc_size((uint64_t)hdr->node_info[u].cum_max_nrec);
-            H5_ASSIGN_OVERFLOW(/* To: */ hdr->node_info[u].cum_max_nrec_size, /* From: */ u_max_nrec_size, /* From: */ unsigned, /* To: */ uint8_t)
+            H5_CHECKED_ASSIGN(hdr->node_info[u].cum_max_nrec_size, uint8_t, u_max_nrec_size, unsigned)
 
             if(NULL == (hdr->node_info[u].nat_rec_fac = H5FL_fac_init(hdr->cls->nrec_size * hdr->node_info[u].max_nrec)))
                 HGOTO_ERROR(H5E_BTREE, H5E_CANTINIT, FAIL, "can't create node native key block factory")
diff --git a/src/H5B2int.c b/src/H5B2int.c
index ef83e93..310aef1 100644
--- a/src/H5B2int.c
+++ b/src/H5B2int.c
@@ -382,13 +382,13 @@ H5B2_split_root(H5B2_hdr_t *hdr, hid_t dxpl_id)
 
     /* Update node info for new depth of tree */
     sz_max_nrec = H5B2_NUM_INT_REC(hdr, hdr->depth);
-    H5_ASSIGN_OVERFLOW(/* To: */ hdr->node_info[hdr->depth].max_nrec, /* From: */ sz_max_nrec, /* From: */ size_t, /* To: */ unsigned)
+    H5_CHECKED_ASSIGN(hdr->node_info[hdr->depth].max_nrec, unsigned, sz_max_nrec, size_t)
     hdr->node_info[hdr->depth].split_nrec = (hdr->node_info[hdr->depth].max_nrec * hdr->split_percent) / 100;
     hdr->node_info[hdr->depth].merge_nrec = (hdr->node_info[hdr->depth].max_nrec * hdr->merge_percent) / 100;
     hdr->node_info[hdr->depth].cum_max_nrec = ((hdr->node_info[hdr->depth].max_nrec + 1) *
         hdr->node_info[hdr->depth - 1].cum_max_nrec) + hdr->node_info[hdr->depth].max_nrec;
     u_max_nrec_size = H5VM_limit_enc_size((uint64_t)hdr->node_info[hdr->depth].cum_max_nrec);
-    H5_ASSIGN_OVERFLOW(/* To: */ hdr->node_info[hdr->depth].cum_max_nrec_size, /* From: */ u_max_nrec_size, /* From: */ unsigned, /* To: */ uint8_t)
+    H5_CHECKED_ASSIGN(hdr->node_info[hdr->depth].cum_max_nrec_size, uint8_t, u_max_nrec_size, unsigned)
     if(NULL == (hdr->node_info[hdr->depth].nat_rec_fac = H5FL_fac_init(hdr->cls->nrec_size * hdr->node_info[hdr->depth].max_nrec)))
 	HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't create node native key block factory")
     if(NULL == (hdr->node_info[hdr->depth].node_ptr_fac = H5FL_fac_init(sizeof(H5B2_node_ptr_t) * (hdr->node_info[hdr->depth].max_nrec + 1))))
@@ -546,7 +546,7 @@ H5B2_redistribute2(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
             /* Count the number of records being moved */
             for(u = 0; u < move_nrec; u++)
                 moved_nrec += right_node_ptrs[u].all_nrec;
-            H5_ASSIGN_OVERFLOW(/* To: */ left_moved_nrec, /* From: */ moved_nrec, /* From: */ hsize_t, /* To: */ hssize_t)
+            H5_CHECKED_ASSIGN(left_moved_nrec, hssize_t, moved_nrec, hsize_t)
             right_moved_nrec -= (hssize_t)moved_nrec;
 
             /* Copy node pointers from right node to left */
@@ -600,7 +600,7 @@ H5B2_redistribute2(H5B2_hdr_t *hdr, hid_t dxpl_id, unsigned depth,
             for(u = 0; u < move_nrec; u++)
                 moved_nrec += right_node_ptrs[u].all_nrec;
             left_moved_nrec -= (hssize_t)moved_nrec;
-            H5_ASSIGN_OVERFLOW(/* To: */ right_moved_nrec, /* From: */ moved_nrec, /* From: */ hsize_t, /* To: */ hssize_t)
+            H5_CHECKED_ASSIGN(right_moved_nrec, hssize_t, moved_nrec, hsize_t)
         } /* end if */
 
         /* Update number of records in child nodes */
@@ -1848,7 +1848,7 @@ H5B2_protect_leaf(H5B2_hdr_t *hdr, hid_t dxpl_id, haddr_t addr, unsigned nrec,
     /* Set up user data for callback */
     udata.f = hdr->f;
     udata.hdr = hdr;
-    H5_ASSIGN_OVERFLOW(/* To: */ udata.nrec, /* From: */ nrec, /* From: */ unsigned, /* To: */ uint16_t)
+    H5_CHECKED_ASSIGN(udata.nrec, uint16_t, nrec, unsigned)
 
     /* Protect the leaf node */
     if(NULL == (ret_value = (H5B2_leaf_t *)H5AC_protect(hdr->f, dxpl_id, H5AC_BT2_LEAF, addr, &udata, rw)))
@@ -1968,8 +1968,8 @@ H5B2_protect_internal(H5B2_hdr_t *hdr, hid_t dxpl_id, haddr_t addr,
     /* Set up user data for callback */
     udata.f = hdr->f;
     udata.hdr = hdr;
-    H5_ASSIGN_OVERFLOW(/* To: */ udata.nrec, /* From: */ nrec, /* From: */ unsigned, /* To: */ uint16_t)
-    H5_ASSIGN_OVERFLOW(/* To: */ udata.depth, /* From: */ depth, /* From: */ unsigned, /* To: */ uint16_t)
+    H5_CHECKED_ASSIGN(udata.nrec, uint16_t, nrec, unsigned)
+    H5_CHECKED_ASSIGN(udata.depth, uint16_t, depth, unsigned)
 
     /* Protect the internal node */
     if(NULL == (ret_value = (H5B2_internal_t *)H5AC_protect(hdr->f, dxpl_id, H5AC_BT2_INT, addr, &udata, rw)))
diff --git a/src/H5Dbtree.c b/src/H5Dbtree.c
index d05de03..4f6b988 100644
--- a/src/H5Dbtree.c
+++ b/src/H5Dbtree.c
@@ -284,7 +284,7 @@ H5D__btree_new_node(H5F_t *f, hid_t UNUSED dxpl_id, H5B_ins_t op,
      * The left key describes the storage of the UDATA chunk being
      * inserted into the tree.
      */
-    H5_ASSIGN_OVERFLOW(lt_key->nbytes, udata->chunk_block.length, hsize_t, uint32_t);
+    H5_CHECKED_ASSIGN(lt_key->nbytes, uint32_t, udata->chunk_block.length, hsize_t);
     lt_key->filter_mask = udata->filter_mask;
     for(u = 0; u < udata->common.layout->ndims; u++)
         lt_key->offset[u] = udata->common.offset[u];
@@ -548,7 +548,7 @@ H5D__btree_insert(H5F_t *f, hid_t UNUSED dxpl_id, haddr_t addr, void *_lt_key,
 	    /* Set node's address (already re-allocated by main chunk routines) */
 	    HDassert(H5F_addr_defined(udata->chunk_block.offset));
             *new_node_p = udata->chunk_block.offset;
-            H5_ASSIGN_OVERFLOW(lt_key->nbytes, udata->chunk_block.length, hsize_t, uint32_t);
+            H5_CHECKED_ASSIGN(lt_key->nbytes, uint32_t, udata->chunk_block.length, hsize_t);
             lt_key->filter_mask = udata->filter_mask;
             *lt_key_changed = TRUE;
             ret_value = H5B_INS_CHANGE;
@@ -568,7 +568,7 @@ H5D__btree_insert(H5F_t *f, hid_t UNUSED dxpl_id, haddr_t addr, void *_lt_key,
          * Split this node, inserting the new new node to the right of the
          * current node.  The MD_KEY is where the split occurs.
          */
-        H5_ASSIGN_OVERFLOW(md_key->nbytes, udata->chunk_block.length, hsize_t, uint32_t);
+        H5_CHECKED_ASSIGN(md_key->nbytes, uint32_t, udata->chunk_block.length, hsize_t);
         md_key->filter_mask = udata->filter_mask;
         for(u = 0; u < udata->common.layout->ndims; u++) {
             HDassert(0 == udata->common.offset[u] % udata->common.layout->dim[u]);
diff --git a/src/H5Dchunk.c b/src/H5Dchunk.c
index b0d935c..d990804 100644
--- a/src/H5Dchunk.c
+++ b/src/H5Dchunk.c
@@ -558,7 +558,7 @@ H5D__chunk_construct(H5F_t UNUSED *f, H5D_t *dset)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "chunk size must be < 4GB")
 
     /* Retain computed chunk size */
-    H5_ASSIGN_OVERFLOW(dset->shared->layout.u.chunk.size, chunk_size, uint64_t, uint32_t);
+    H5_CHECKED_ASSIGN(dset->shared->layout.u.chunk.size, uint32_t, chunk_size, uint64_t);
 
     /* Reset address and pointer of the array struct for the chunked storage index */
     if(H5D_chunk_idx_reset(&dset->shared->layout.storage.u.chunk, TRUE) < 0)
@@ -718,7 +718,7 @@ H5D__chunk_io_init(const H5D_io_info_t *io_info, const H5D_type_info_t *type_inf
     if((sm_ndims = H5S_GET_EXTENT_NDIMS(mem_space)) < 0)
         HGOTO_ERROR(H5E_DATASPACE, H5E_CANTGET, FAIL, "unable to get dimension number")
     /* Set the number of dimensions for the memory dataspace */
-    H5_ASSIGN_OVERFLOW(fm->m_ndims, sm_ndims, int, unsigned);
+    H5_CHECKED_ASSIGN(fm->m_ndims, unsigned, sm_ndims, int);
 
     /* Get rank for file dataspace */
     fm->f_ndims = f_ndims = dataset->shared->layout.u.chunk.ndims - 1;
@@ -1317,7 +1317,7 @@ H5D__create_chunk_file_map_hyper(H5D_chunk_map_t *fm, const H5D_io_info_t
             /* Get number of elements selected in chunk */
             if((schunk_points = H5S_GET_SELECT_NPOINTS(tmp_fchunk)) < 0)
                 HGOTO_ERROR(H5E_DATASPACE, H5E_CANTGET, FAIL, "can't get file selection # of elements")
-            H5_ASSIGN_OVERFLOW(new_chunk_info->chunk_points, schunk_points, hssize_t, uint32_t);
+            H5_CHECKED_ASSIGN(new_chunk_info->chunk_points, uint32_t, schunk_points, hssize_t);
 
             /* Decrement # of points left in file selection */
             sel_points -= (hsize_t)schunk_points;
@@ -1793,7 +1793,7 @@ H5D__chunk_read(H5D_io_info_t *io_info, const H5D_type_info_t *type_info,
     ctg_io_info.layout_ops = *H5D_LOPS_CONTIG;
 
     /* Initialize temporary contiguous storage info */
-    H5_ASSIGN_OVERFLOW(ctg_store.contig.dset_size, io_info->dset->shared->layout.u.chunk.size, uint32_t, hsize_t);
+    H5_CHECKED_ASSIGN(ctg_store.contig.dset_size, hsize_t, io_info->dset->shared->layout.u.chunk.size, uint32_t);
 
     /* Set up compact I/O info object */
     HDmemcpy(&cpt_io_info, io_info, sizeof(cpt_io_info));
@@ -1938,7 +1938,7 @@ H5D__chunk_write(H5D_io_info_t *io_info, const H5D_type_info_t *type_info,
     ctg_io_info.layout_ops = *H5D_LOPS_CONTIG;
 
     /* Initialize temporary contiguous storage info */
-    H5_ASSIGN_OVERFLOW(ctg_store.contig.dset_size, io_info->dset->shared->layout.u.chunk.size, uint32_t, hsize_t);
+    H5_CHECKED_ASSIGN(ctg_store.contig.dset_size, hsize_t, io_info->dset->shared->layout.u.chunk.size, uint32_t);
 
     /* Set up compact I/O info object */
     HDmemcpy(&cpt_io_info, io_info, sizeof(cpt_io_info));
@@ -2248,7 +2248,7 @@ H5D__chunk_cinfo_cache_update(H5D_chunk_cached_t *last, const H5D_chunk_ud_t *ud
     /* Stored the information to cache */
     HDmemcpy(last->offset, udata->common.offset, sizeof(hsize_t) * udata->common.layout->ndims);
     last->addr = udata->chunk_block.offset;
-    H5_ASSIGN_OVERFLOW(last->nbytes, udata->chunk_block.length, hsize_t, uint32_t);
+    H5_CHECKED_ASSIGN(last->nbytes, uint32_t, udata->chunk_block.length, hsize_t);
     last->filter_mask = udata->filter_mask;
 
     /* Indicate that the cached info is valid */
@@ -2517,7 +2517,7 @@ H5D__chunk_flush_entry(const H5D_t *dset, hid_t dxpl_id, const H5D_dxpl_cache_t
                 point_of_no_return = TRUE;
                 ent->chunk = NULL;
             } /* end else */
-            H5_ASSIGN_OVERFLOW(nbytes, udata.chunk_block.length, hsize_t, size_t);
+            H5_CHECKED_ASSIGN(nbytes, size_t, udata.chunk_block.length, hsize_t);
             if(H5Z_pipeline(&(dset->shared->dcpl_cache.pline), 0, &(udata.filter_mask), dxpl_cache->err_detect,
                      dxpl_cache->filter_cb, &nbytes, &alloc, &buf) < 0)
                 HGOTO_ERROR(H5E_PLINE, H5E_CANTFILTER, FAIL, "output pipeline failed")
@@ -2526,7 +2526,7 @@ H5D__chunk_flush_entry(const H5D_t *dset, hid_t dxpl_id, const H5D_dxpl_cache_t
             if(nbytes > ((size_t)0xffffffff))
                 HGOTO_ERROR(H5E_DATASET, H5E_BADRANGE, FAIL, "chunk too large for 32-bit length")
 #endif /* H5_SIZEOF_SIZE_T > 4 */
-            H5_ASSIGN_OVERFLOW(udata.chunk_block.length, nbytes, size_t, hsize_t);
+            H5_CHECKED_ASSIGN(udata.chunk_block.length, hsize_t, nbytes, size_t);
 
             /* Indicate that the chunk must be allocated */
             must_alloc = TRUE;
@@ -2835,7 +2835,7 @@ H5D__chunk_lock(const H5D_io_info_t *io_info, H5D_chunk_ud_t *udata,
 
     /* Get the chunk's size */
     HDassert(layout->u.chunk.size > 0);
-    H5_ASSIGN_OVERFLOW(chunk_size, layout->u.chunk.size, uint32_t, size_t);
+    H5_CHECKED_ASSIGN(chunk_size, size_t, layout->u.chunk.size, uint32_t);
 
     /* Check if the chunk is in the cache */
     if(UINT_MAX != udata->idx_hint) {
@@ -3000,8 +3000,8 @@ H5D__chunk_lock(const H5D_io_info_t *io_info, H5D_chunk_ud_t *udata,
                 ent->chunk_block.offset = chunk_addr;
                 ent->chunk_block.length = chunk_alloc;
                 HDmemcpy(ent->offset, io_info->store->chunk.offset, sizeof(hsize_t) * layout->u.chunk.ndims);
-                H5_ASSIGN_OVERFLOW(ent->rd_count, chunk_size, size_t, uint32_t);
-                H5_ASSIGN_OVERFLOW(ent->wr_count, chunk_size, size_t, uint32_t);
+                H5_CHECKED_ASSIGN(ent->rd_count, uint32_t, chunk_size, size_t);
+                H5_CHECKED_ASSIGN(ent->wr_count, uint32_t, chunk_size, size_t);
                 ent->chunk = (uint8_t *)chunk;
 
                 /* Add it to the cache */
@@ -3321,7 +3321,7 @@ H5D__chunk_allocate(const H5D_t *dset, hid_t dxpl_id, hbool_t full_overwrite,
         HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't fill dxpl cache")
 
     /* Get original chunk size */
-    H5_ASSIGN_OVERFLOW(orig_chunk_size, layout->u.chunk.size, uint32_t, size_t);
+    H5_CHECKED_ASSIGN(orig_chunk_size, size_t, layout->u.chunk.size, uint32_t);
 
     /* Check the dataset's fill-value status */
     if(H5P_is_fill_value_defined(fill, &fill_status) < 0)
@@ -3498,7 +3498,7 @@ H5D__chunk_allocate(const H5D_t *dset, hid_t dxpl_id, hbool_t full_overwrite,
             udata.common.storage = &layout->storage.u.chunk;
             udata.common.offset = chunk_offset;
             udata.chunk_block.offset = HADDR_UNDEF;
-            H5_ASSIGN_OVERFLOW(udata.chunk_block.length, chunk_size, size_t, uint32_t);
+            H5_CHECKED_ASSIGN(udata.chunk_block.length, uint32_t, chunk_size, size_t);
             udata.filter_mask = filter_mask;
 
             /* Allocate the chunk (with all processes) */
@@ -3656,9 +3656,9 @@ H5D__chunk_collective_fill(const H5D_t *dset, hid_t dxpl_id,
     leftover_blocks = chunk_info->num_io % mpi_size;
 
     /* Cast values to types needed by MPI */
-    H5_ASSIGN_OVERFLOW(blocks, num_blocks, size_t, int);
-    H5_ASSIGN_OVERFLOW(leftover, leftover_blocks, size_t, int);
-    H5_ASSIGN_OVERFLOW(block_len,  chunk_size, size_t, int);
+    H5_CHECKED_ASSIGN(blocks, int, num_blocks, size_t);
+    H5_CHECKED_ASSIGN(leftover, int, leftover_blocks, size_t);
+    H5_CHECKED_ASSIGN(block_len, int,  chunk_size, size_t);
 
     /* Allocate buffers */
     /* (MSC - should not need block_lens if MPI_type_create_hindexed_block is working) */
@@ -3787,7 +3787,7 @@ H5D__chunk_prune_fill(H5D_chunk_it_ud1_t *udata)
 
     /* Get the chunk's size */
     HDassert(layout->u.chunk.size > 0);
-    H5_ASSIGN_OVERFLOW(chunk_size, layout->u.chunk.size, uint32_t, size_t);
+    H5_CHECKED_ASSIGN(chunk_size, size_t, layout->u.chunk.size, uint32_t);
 
     /* Get the info for the chunk in the file */
     if(H5D__chunk_lookup(dset, io_info->dxpl_id, chunk_offset, io_info->store->chunk.index, &chk_udata) < 0)
@@ -4558,7 +4558,7 @@ H5D__chunk_copy_cb(const H5D_chunk_rec_t *chunk_rec, void *_udata)
     FUNC_ENTER_STATIC
 
     /* Get 'size_t' local value for number of bytes in chunk */
-    H5_ASSIGN_OVERFLOW(nbytes, chunk_rec->nbytes, uint32_t, size_t);
+    H5_CHECKED_ASSIGN(nbytes, size_t, chunk_rec->nbytes, uint32_t);
 
     /* Check parameter for type conversion */
     if(udata->do_convert) {
@@ -4675,7 +4675,7 @@ H5D__chunk_copy_cb(const H5D_chunk_rec_t *chunk_rec, void *_udata)
         if(nbytes > ((size_t)0xffffffff))
             HGOTO_ERROR(H5E_DATASET, H5E_BADRANGE, H5_ITER_ERROR, "chunk too large for 32-bit length")
 #endif /* H5_SIZEOF_SIZE_T > 4 */
-        H5_ASSIGN_OVERFLOW(udata_dst.chunk_block.length, nbytes, size_t, uint32_t);
+        H5_CHECKED_ASSIGN(udata_dst.chunk_block.length, uint32_t, nbytes, size_t);
 	udata->buf = buf;
 	udata->buf_size = buf_size;
     } /* end if */
@@ -4777,7 +4777,7 @@ H5D__chunk_copy(H5F_t *f_src, H5O_storage_chunk_t *storage_src,
         /* Get the dim info for dataset */
         if((sndims = H5S_extent_get_dims(ds_extent_src, curr_dims, NULL)) < 0)
             HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get dataspace dimensions")
-        H5_ASSIGN_OVERFLOW(ndims, sndims, int, unsigned);
+        H5_CHECKED_ASSIGN(ndims, unsigned, sndims, int);
 
         /* Set the source layout chunk information */
         if(H5D__chunk_set_info_real(layout_src, ndims, curr_dims) < 0)
@@ -4885,7 +4885,7 @@ H5D__chunk_copy(H5F_t *f_src, H5O_storage_chunk_t *storage_src,
             do_convert = TRUE;
         } /* end if */
 
-        H5_ASSIGN_OVERFLOW(buf_size, layout_src->size, uint32_t, size_t);
+        H5_CHECKED_ASSIGN(buf_size, size_t, layout_src->size, uint32_t);
         reclaim_buf_size = 0;
     } /* end else */
 
diff --git a/src/H5Dcompact.c b/src/H5Dcompact.c
index 1d8b97c..af70c07 100644
--- a/src/H5Dcompact.c
+++ b/src/H5Dcompact.c
@@ -197,7 +197,7 @@ H5D__compact_construct(H5F_t *f, H5D_t *dset)
     tmp_size = H5T_get_size(dset->shared->type);
     HDassert(tmp_size > 0);
     tmp_size = tmp_size * (hsize_t)stmp_size;
-    H5_ASSIGN_OVERFLOW(dset->shared->layout.storage.u.compact.size, tmp_size, hssize_t, size_t);
+    H5_CHECKED_ASSIGN(dset->shared->layout.storage.u.compact.size, size_t, tmp_size, hssize_t);
 
     /* Verify data size is smaller than maximum header message size
      * (64KB) minus other layout message fields.
diff --git a/src/H5Dcontig.c b/src/H5Dcontig.c
index e913a3f..898b46d 100644
--- a/src/H5Dcontig.c
+++ b/src/H5Dcontig.c
@@ -259,7 +259,7 @@ H5D__contig_fill(const H5D_t *dset, hid_t dxpl_id)
     /* Get the number of elements in the dataset's dataspace */
     if((snpoints = H5S_GET_EXTENT_NPOINTS(dset->shared->space)) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "dataset has negative number of elements")
-    H5_ASSIGN_OVERFLOW(npoints, snpoints, hssize_t, size_t);
+    H5_CHECKED_ASSIGN(npoints, size_t, snpoints, hssize_t);
 
     /* Initialize the fill value buffer */
     if(H5D__fill_init(&fb_info, NULL, NULL, NULL, NULL, NULL,
@@ -644,6 +644,7 @@ H5D__contig_readvv_sieve_cb(hsize_t dst_off, hsize_t src_off, size_t len,
     size_t sieve_size = (size_t)-1;   /* Size of sieve buffer */
     haddr_t rel_eoa;	        /* Relative end of file address	*/
     hsize_t max_data;           /* Actual maximum size of data to cache */
+    hsize_t min;                /* temporary minimum value (avoids some ugly macro nesting) */
     herr_t ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_STATIC
@@ -684,7 +685,8 @@ H5D__contig_readvv_sieve_cb(hsize_t dst_off, hsize_t src_off, size_t len,
             max_data = store_contig->dset_size - dst_off;
 
             /* Compute the size of the sieve buffer */
-            H5_ASSIGN_OVERFLOW(dset_contig->sieve_size, MIN3(rel_eoa - dset_contig->sieve_loc, max_data, dset_contig->sieve_buf_size), hsize_t, size_t);
+            min = MIN3(rel_eoa - dset_contig->sieve_loc, max_data, dset_contig->sieve_buf_size);
+            H5_CHECKED_ASSIGN(dset_contig->sieve_size, size_t, min, hsize_t);
 
             /* Read the new sieve buffer */
             if(H5F_block_read(file, H5FD_MEM_DRAW, dset_contig->sieve_loc, dset_contig->sieve_size, udata->dxpl_id, dset_contig->sieve_buf) < 0)
@@ -757,9 +759,13 @@ H5D__contig_readvv_sieve_cb(hsize_t dst_off, hsize_t src_off, size_t len,
                 /* Only need this when resizing sieve buffer */
                 max_data = store_contig->dset_size - dst_off;
 
-                /* Compute the size of the sieve buffer */
-                /* Don't read off the end of the file, don't read past the end of the data element and don't read more than the buffer size */
-                H5_ASSIGN_OVERFLOW(dset_contig->sieve_size, MIN3(rel_eoa - dset_contig->sieve_loc, max_data, dset_contig->sieve_buf_size), hsize_t, size_t);
+                /* Compute the size of the sieve buffer.
+                 * Don't read off the end of the file, don't read past
+                 * the end of the data element, and don't read more than
+                 * the buffer size.
+                 */
+                min = MIN3(rel_eoa - dset_contig->sieve_loc, max_data, dset_contig->sieve_buf_size); 
+                H5_CHECKED_ASSIGN(dset_contig->sieve_size, size_t, min, hsize_t);
 
                 /* Update local copies of sieve information */
                 sieve_start = dset_contig->sieve_loc;
@@ -915,6 +921,7 @@ H5D__contig_writevv_sieve_cb(hsize_t dst_off, hsize_t src_off, size_t len,
     size_t sieve_size = (size_t)-1; /* size of sieve buffer */
     haddr_t rel_eoa;	        /* Relative end of file address	*/
     hsize_t max_data;           /* Actual maximum size of data to cache */
+    hsize_t min;                /* temporary minimum value (avoids some ugly macro nesting) */
     herr_t ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_STATIC
@@ -960,7 +967,8 @@ if(dset_contig->sieve_size > len)
             max_data = store_contig->dset_size - dst_off;
 
             /* Compute the size of the sieve buffer */
-            H5_ASSIGN_OVERFLOW(dset_contig->sieve_size, MIN3(rel_eoa - dset_contig->sieve_loc, max_data, dset_contig->sieve_buf_size), hsize_t, size_t);
+            min = MIN3(rel_eoa - dset_contig->sieve_loc, max_data, dset_contig->sieve_buf_size); 
+            H5_CHECKED_ASSIGN(dset_contig->sieve_size, size_t, min, hsize_t);
 
             /* Check if there is any point in reading the data from the file */
             if(dset_contig->sieve_size > len) {
@@ -1075,9 +1083,13 @@ if(dset_contig->sieve_size > len)
                     /* Only need this when resizing sieve buffer */
                     max_data = store_contig->dset_size - dst_off;
 
-                    /* Compute the size of the sieve buffer */
-                    /* Don't read off the end of the file, don't read past the end of the data element and don't read more than the buffer size */
-                    H5_ASSIGN_OVERFLOW(dset_contig->sieve_size, MIN3(rel_eoa - dset_contig->sieve_loc, max_data, dset_contig->sieve_buf_size), hsize_t, size_t);
+                    /* Compute the size of the sieve buffer.
+                     * Don't read off the end of the file, don't read past
+                     * the end of the data element, and don't read more than
+                     * the buffer size.
+                     */
+                    min = MIN3(rel_eoa - dset_contig->sieve_loc, max_data, dset_contig->sieve_buf_size); 
+                    H5_CHECKED_ASSIGN(dset_contig->sieve_size, size_t, min, hsize_t);
 
                     /* Update local copies of sieve information */
                     sieve_start = dset_contig->sieve_loc;
diff --git a/src/H5Defl.c b/src/H5Defl.c
index 355492f..6707568 100644
--- a/src/H5Defl.c
+++ b/src/H5Defl.c
@@ -170,7 +170,7 @@ H5D__efl_construct(H5F_t *f, H5D_t *dset)
     stmp_size = H5S_GET_EXTENT_NPOINTS(dset->shared->space);
     HDassert(stmp_size >= 0);
     tmp_size = (hsize_t)stmp_size * dt_size;
-    H5_ASSIGN_OVERFLOW(dset->shared->layout.storage.u.contig.size, tmp_size, hssize_t, hsize_t);
+    H5_CHECKED_ASSIGN(dset->shared->layout.storage.u.contig.size, hsize_t, tmp_size, hssize_t);
 
     /* Get the sieve buffer size for this dataset */
     dset->shared->cache.contig.sieve_buf_size = H5F_SIEVE_BUF_SIZE(f);
diff --git a/src/H5Dio.c b/src/H5Dio.c
index 44080dc..f9e8f37 100644
--- a/src/H5Dio.c
+++ b/src/H5Dio.c
@@ -409,7 +409,7 @@ H5D__read(H5D_t *dataset, hid_t mem_type_id, const H5S_t *mem_space,
         mem_space = file_space;
     if((snelmts = H5S_GET_SELECT_NPOINTS(mem_space)) < 0)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "dst dataspace has invalid selection")
-    H5_ASSIGN_OVERFLOW(nelmts,snelmts,hssize_t,hsize_t);
+    H5_CHECKED_ASSIGN(nelmts, hsize_t, snelmts, hssize_t);
 
     /* Fill the DXPL cache values for later use */
     if(H5D__get_dxpl_cache(dxpl_id, &dxpl_cache) < 0)
@@ -679,7 +679,7 @@ H5D__write(H5D_t *dataset, hid_t mem_type_id, const H5S_t *mem_space,
 
     if((snelmts = H5S_GET_SELECT_NPOINTS(mem_space)) < 0)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "src dataspace has invalid selection")
-    H5_ASSIGN_OVERFLOW(nelmts, snelmts, hssize_t, hsize_t);
+    H5_CHECKED_ASSIGN(nelmts, hsize_t, snelmts, hssize_t);
 
     /* Make certain that the number of elements in each selection is the same */
     if(nelmts != (hsize_t)H5S_GET_SELECT_NPOINTS(file_space))
diff --git a/src/H5Dmpio.c b/src/H5Dmpio.c
index db487cd..825c562 100644
--- a/src/H5Dmpio.c
+++ b/src/H5Dmpio.c
@@ -438,7 +438,7 @@ H5D__mpio_get_sum_chunk(const H5D_io_info_t *io_info, const H5D_chunk_map_t *fm,
     /* Get the number of chunks to perform I/O on */
     num_chunkf = 0;
     ori_num_chunkf = H5SL_count(fm->sel_chunks);
-    H5_ASSIGN_OVERFLOW(num_chunkf, ori_num_chunkf, size_t, int);
+    H5_CHECKED_ASSIGN(num_chunkf, int, ori_num_chunkf, size_t);
 
     /* Determine the summation of number of chunks for all processes */
     if(MPI_SUCCESS != (mpi_code = MPI_Allreduce(&num_chunkf, sum_chunkf, 1, MPI_INT, MPI_SUM, io_info->comm)))
@@ -826,7 +826,7 @@ H5D__link_chunk_collective_io(H5D_io_info_t *io_info, const H5D_type_info_t *typ
     } /* end if */
 
     /* Retrieve total # of chunks in dataset */
-    H5_ASSIGN_OVERFLOW(total_chunks, fm->layout->u.chunk.nchunks, hsize_t, size_t);
+    H5_CHECKED_ASSIGN(total_chunks, size_t, fm->layout->u.chunk.nchunks, hsize_t);
 
     /* Handle special case when dataspace dimensions only allow one chunk in
      *  the dataset.  [This sometimes is used by developers who want the
@@ -1148,7 +1148,7 @@ H5D__multi_chunk_collective_io(H5D_io_info_t *io_info, const H5D_type_info_t *ty
 #endif
 
     /* Retrieve total # of chunks in dataset */
-    H5_ASSIGN_OVERFLOW(total_chunk, fm->layout->u.chunk.nchunks, hsize_t, size_t);
+    H5_CHECKED_ASSIGN(total_chunk, size_t, fm->layout->u.chunk.nchunks, hsize_t);
     HDassert(total_chunk != 0);
 
     /* Allocate memories */
@@ -1699,7 +1699,7 @@ H5D__obtain_mpio_mode(H5D_io_info_t* io_info, H5D_chunk_map_t *fm,
         HGOTO_ERROR(H5E_IO, H5E_MPI, FAIL, "unable to obtain mpi size")
 
     /* Setup parameters */
-    H5_ASSIGN_OVERFLOW(total_chunks, fm->layout->u.chunk.nchunks, hsize_t, int);
+    H5_CHECKED_ASSIGN(total_chunks, int, fm->layout->u.chunk.nchunks, hsize_t);
     percent_nproc_per_chunk = H5P_peek_unsigned(dx_plist, H5D_XFER_MPIO_CHUNK_OPT_RATIO_NAME);
     /* if ratio is 0, perform collective io */
     if(0 == percent_nproc_per_chunk) {
diff --git a/src/H5FAdblock.c b/src/H5FAdblock.c
index 80e2159..9efc2bc 100644
--- a/src/H5FAdblock.c
+++ b/src/H5FAdblock.c
@@ -129,7 +129,7 @@ H5FA__dblock_alloc(H5FA_hdr_t *hdr, hsize_t nelmts))
         hsize_t npages = ((nelmts + dblock->dblk_page_nelmts) - 1) / dblock->dblk_page_nelmts;
 
         /* Safely assign the number of pages */
-        H5_ASSIGN_OVERFLOW(/* To: */ dblock->npages, /* From: */ npages, /* From: */ hsize_t, /* To: */ size_t);
+        H5_CHECKED_ASSIGN(dblock->npages, size_t, npages, hsize_t);
 
 	/* Sanity check that we have at least 1 page */
 	HDassert(dblock->npages > 0);
diff --git a/src/H5FDcore.c b/src/H5FDcore.c
index ba4270e..f9bda00 100644
--- a/src/H5FDcore.c
+++ b/src/H5FDcore.c
@@ -1300,7 +1300,7 @@ H5FD_core_write(H5FD_t *_file, H5FD_mem_t UNUSED type, hid_t UNUSED dxpl_id, had
         size_t new_eof;
 
         /* Determine new size of memory buffer */
-        H5_ASSIGN_OVERFLOW(new_eof, file->increment * ((addr + size) / file->increment), hsize_t, size_t);
+        H5_CHECKED_ASSIGN(new_eof, size_t, file->increment * ((addr + size) / file->increment), hsize_t);
         if((addr + size) % file->increment)
             new_eof += file->increment;
 
@@ -1469,7 +1469,7 @@ H5FD_core_truncate(H5FD_t *_file, hid_t UNUSED dxpl_id, hbool_t closing)
             new_eof = file->eoa;
         else { /* set eof to smallest multiple of increment that exceeds eoa */
             /* Determine new size of memory buffer */
-            H5_ASSIGN_OVERFLOW(new_eof, file->increment * (file->eoa / file->increment), hsize_t, size_t);
+            H5_CHECKED_ASSIGN(new_eof, size_t, file->increment * (file->eoa / file->increment), hsize_t);
             if(file->eoa % file->increment)
                 new_eof += file->increment;
         } /* end else */
diff --git a/src/H5FDdirect.c b/src/H5FDdirect.c
index 7507a2e..c2b0660 100644
--- a/src/H5FDdirect.c
+++ b/src/H5FDdirect.c
@@ -515,7 +515,7 @@ H5FD_direct_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t maxadd
         HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, NULL, "bad VFL driver info")
 
     file->fd = fd;
-    H5_ASSIGN_OVERFLOW(file->eof,sb.st_size,h5_stat_size_t,haddr_t);
+    H5_CHECKED_ASSIGN(file->eof, haddr_t, sb.st_size, h5_stat_size_t);
     file->pos = HADDR_UNDEF;
     file->op = OP_UNKNOWN;
 #ifdef H5_HAVE_WIN32_API
diff --git a/src/H5FDfamily.c b/src/H5FDfamily.c
index ad703ef..e79e1cf 100644
--- a/src/H5FDfamily.c
+++ b/src/H5FDfamily.c
@@ -1170,7 +1170,7 @@ H5FD_family_read(H5FD_t *_file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr, si
 
     /* Read from each member */
     while(size > 0) {
-        H5_ASSIGN_OVERFLOW(u,addr /file->memb_size,hsize_t,unsigned);
+        H5_CHECKED_ASSIGN(u, unsigned, addr / file->memb_size, hsize_t);
 
         sub = addr % file->memb_size;
 
@@ -1239,7 +1239,7 @@ H5FD_family_write(H5FD_t *_file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr, s
 
     /* Write to each member */
     while (size>0) {
-        H5_ASSIGN_OVERFLOW(u,addr /file->memb_size,hsize_t,unsigned);
+        H5_CHECKED_ASSIGN(u, unsigned, addr / file->memb_size, hsize_t);
 
         sub = addr % file->memb_size;
 
diff --git a/src/H5FDlog.c b/src/H5FDlog.c
index a2284dd..cc0caa4 100644
--- a/src/H5FDlog.c
+++ b/src/H5FDlog.c
@@ -571,7 +571,7 @@ H5FD_log_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t maxaddr)
         HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "unable to allocate file struct")
 
     file->fd = fd;
-    H5_ASSIGN_OVERFLOW(file->eof, sb.st_size, h5_stat_size_t, haddr_t);
+    H5_CHECKED_ASSIGN(file->eof, haddr_t, sb.st_size, h5_stat_size_t);
     file->pos = HADDR_UNDEF;
     file->op = OP_UNKNOWN;
 #ifdef H5_HAVE_WIN32_API
diff --git a/src/H5FDsec2.c b/src/H5FDsec2.c
index 1130789..b938c41 100644
--- a/src/H5FDsec2.c
+++ b/src/H5FDsec2.c
@@ -358,7 +358,7 @@ H5FD_sec2_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t maxaddr)
         HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "unable to allocate file struct")
 
     file->fd = fd;
-    H5_ASSIGN_OVERFLOW(file->eof, sb.st_size, h5_stat_size_t, haddr_t);
+    H5_CHECKED_ASSIGN(file->eof, haddr_t, sb.st_size, h5_stat_size_t);
     file->pos = HADDR_UNDEF;
     file->op = OP_UNKNOWN;
 #ifdef H5_HAVE_WIN32_API
diff --git a/src/H5FScache.c b/src/H5FScache.c
index e03a0a4..306a3fd 100644
--- a/src/H5FScache.c
+++ b/src/H5FScache.c
@@ -578,7 +578,7 @@ H5FS_cache_sinfo_load(H5F_t *f, hid_t dxpl_id, haddr_t UNUSED addr, void *_udata
 	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
 
     /* Allocate space for the buffer to serialize the sections into */
-    H5_ASSIGN_OVERFLOW(/* To: */ old_sect_size, /* From: */ udata->fspace->sect_size, /* From: */ hsize_t, /* To: */ size_t);
+    H5_CHECKED_ASSIGN(old_sect_size, size_t, udata->fspace->sect_size, hsize_t);
     if(NULL == (buf = H5FL_BLK_MALLOC(sect_block, (size_t)udata->fspace->sect_size)))
         HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
 
@@ -1038,7 +1038,7 @@ H5FS_cache_sinfo_size(const H5F_t UNUSED *f, const H5FS_sinfo_t *sinfo, size_t *
     HDassert(size_ptr);
 
     /* Set size value */
-    H5_ASSIGN_OVERFLOW(/* To: */ *size_ptr, /* From: */ sinfo->fspace->alloc_sect_size, /* From: */ hsize_t, /* To: */ size_t);
+    H5_CHECKED_ASSIGN(*size_ptr, size_t, sinfo->fspace->alloc_sect_size, hsize_t);
 
     FUNC_LEAVE_NOAPI(SUCCEED)
 } /* H5FS_cache_sinfo_size() */
diff --git a/src/H5Faccum.c b/src/H5Faccum.c
index 7eb75bd..7cd9abb 100644
--- a/src/H5Faccum.c
+++ b/src/H5Faccum.c
@@ -172,7 +172,7 @@ H5F__accum_read(const H5F_io_info_t *fio_info, H5FD_mem_t type, haddr_t addr,
                 /* Read the part before the metadata accumulator */
                 if(addr < accum->loc) {
                     /* Set the amount to read */
-                    H5_ASSIGN_OVERFLOW(amount_before, (accum->loc - addr), hsize_t, size_t);
+                    H5_CHECKED_ASSIGN(amount_before, size_t, (accum->loc - addr), hsize_t);
 
                     /* Make room for the metadata to read in */
                     HDmemmove(accum->buf + amount_before, accum->buf, accum->size);
@@ -193,7 +193,7 @@ H5F__accum_read(const H5F_io_info_t *fio_info, H5FD_mem_t type, haddr_t addr,
                     size_t amount_after;         /* Amount to read at a time */
 
                     /* Set the amount to read */
-                    H5_ASSIGN_OVERFLOW(amount_after, ((addr + size) - (accum->loc + accum->size)), hsize_t, size_t);
+                    H5_CHECKED_ASSIGN(amount_after, size_t, ((addr + size) - (accum->loc + accum->size)), hsize_t);
 
                     /* Dispatch to driver */
                     if(H5FD_read(fio_info->f->shared->lf, fio_info->dxpl, map_type, (accum->loc + accum->size), amount_after, (accum->buf + accum->size + amount_before)) < 0)
@@ -536,14 +536,14 @@ H5F__accum_write(const H5F_io_info_t *fio_info, H5FD_mem_t type, haddr_t addr,
                         size_t old_offset;  /* Offset of old data within the accumulator buffer */
 
                         /* Calculate the amount we will need to add to the accumulator size, based on the amount of overlap */
-                        H5_ASSIGN_OVERFLOW(add_size, (accum->loc - addr), hsize_t, size_t);
+                        H5_CHECKED_ASSIGN(add_size, size_t, (accum->loc - addr), hsize_t);
 
                         /* Check if we need to adjust accumulator size */
                         if(H5F__accum_adjust(accum, fio_info, H5F_ACCUM_PREPEND, add_size) < 0)
                             HGOTO_ERROR(H5E_IO, H5E_CANTRESIZE, FAIL, "can't adjust metadata accumulator")
 
                         /* Calculate the proper offset of the existing metadata */
-                        H5_ASSIGN_OVERFLOW(old_offset, (addr + size) - accum->loc, hsize_t, size_t);
+                        H5_CHECKED_ASSIGN(old_offset, size_t, (addr + size) - accum->loc, hsize_t);
 
                         /* Move the existing metadata to the proper location */
                         HDmemmove(accum->buf + size, accum->buf + old_offset, (accum->size - old_offset));
@@ -576,7 +576,7 @@ H5F__accum_write(const H5F_io_info_t *fio_info, H5FD_mem_t type, haddr_t addr,
                         size_t dirty_off;           /* Offset of dirty region */
 
                         /* Calculate the amount we will need to add to the accumulator size, based on the amount of overlap */
-                        H5_ASSIGN_OVERFLOW(add_size, (addr + size) - (accum->loc + accum->size), hsize_t, size_t);
+                        H5_CHECKED_ASSIGN(add_size, size_t, (addr + size) - (accum->loc + accum->size), hsize_t);
 
                         /* Check if we need to adjust accumulator size */
                         if(H5F__accum_adjust(accum, fio_info, H5F_ACCUM_APPEND, add_size) < 0)
@@ -885,7 +885,7 @@ H5F__accum_free(const H5F_io_info_t *fio_info, H5FD_mem_t UNUSED type, haddr_t a
                 size_t new_accum_size;      /* Size of new accumulator buffer */
 
                 /* Calculate the size of the overlap with the accumulator, etc. */
-                H5_ASSIGN_OVERFLOW(overlap_size, (addr + size) - accum->loc, haddr_t, size_t);
+                H5_CHECKED_ASSIGN(overlap_size, size_t, (addr + size) - accum->loc, haddr_t);
                 new_accum_size = accum->size - overlap_size;
 
                 /* Move the accumulator buffer information to eliminate the freed block */
@@ -919,7 +919,7 @@ H5F__accum_free(const H5F_io_info_t *fio_info, H5FD_mem_t UNUSED type, haddr_t a
             haddr_t dirty_start = accum->loc + accum->dirty_off;
 
             /* Calculate the size of the overlap with the accumulator */
-            H5_ASSIGN_OVERFLOW(overlap_size, (accum->loc + accum->size) - addr, haddr_t, size_t);
+            H5_CHECKED_ASSIGN(overlap_size, size_t, (accum->loc + accum->size) - addr, haddr_t);
 
             /* Check if block to free begins before end of dirty region */
             if(accum->dirty && H5F_addr_lt(addr, dirty_end)) {
diff --git a/src/H5Fsuper.c b/src/H5Fsuper.c
index dd80a46..845ab8c 100644
--- a/src/H5Fsuper.c
+++ b/src/H5Fsuper.c
@@ -434,7 +434,7 @@ H5F_super_init(H5F_t *f, hid_t dxpl_id)
     superblock_size = (hsize_t)H5F_SUPERBLOCK_SIZE(super_vers, f);
 
     /* Compute the size of the driver information block */
-    H5_ASSIGN_OVERFLOW(driver_size, H5FD_sb_size(f->shared->lf), hsize_t, size_t);
+    H5_CHECKED_ASSIGN(driver_size, size_t, H5FD_sb_size(f->shared->lf), hsize_t);
     if(driver_size > 0) {
         driver_size += H5F_DRVINFOBLOCK_HDR_SIZE;
 
diff --git a/src/H5Fsuper_cache.c b/src/H5Fsuper_cache.c
index f3931cb..5737ce4 100644
--- a/src/H5Fsuper_cache.c
+++ b/src/H5Fsuper_cache.c
@@ -723,7 +723,7 @@ H5F_sblock_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t UNUSED addr,
                 HGOTO_ERROR(H5E_FILE, H5E_CANTENCODE, FAIL, "can't encode root group symbol table entry")
 
             /* Encode the driver information block. */
-            H5_ASSIGN_OVERFLOW(driver_size, H5FD_sb_size(f->shared->lf), hsize_t, size_t);
+            H5_CHECKED_ASSIGN(driver_size, size_t, H5FD_sb_size(f->shared->lf), hsize_t);
 
             /* Checking whether driver block address is defined here is to handle backward
              * compatibility.  If the file was created with v1.6 library or earlier and no
@@ -799,7 +799,7 @@ H5F_sblock_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t UNUSED addr,
         } /* end else */
 
         /* Retrieve the total size of the superblock info */
-        H5_ASSIGN_OVERFLOW(superblock_size, (p - buf), ptrdiff_t, size_t);
+        H5_CHECKED_ASSIGN(superblock_size, size_t, (p - buf), ptrdiff_t);
 
         /* Double check we didn't overrun the block (unlikely) */
         HDassert(superblock_size <= sizeof(buf));
@@ -824,7 +824,7 @@ H5F_sblock_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t UNUSED addr,
             /* Check for ignoring the driver info for this file */
             if(!H5F_HAS_FEATURE(f, H5FD_FEAT_IGNORE_DRVRINFO)) {
                 /* Check for driver info message */
-                H5_ASSIGN_OVERFLOW(driver_size, H5FD_sb_size(f->shared->lf), hsize_t, size_t);
+                H5_CHECKED_ASSIGN(driver_size, size_t, H5FD_sb_size(f->shared->lf), hsize_t);
                 if(driver_size > 0) {
                     H5O_drvinfo_t drvinfo;      /* Driver info */
                     uint8_t dbuf[H5F_MAX_DRVINFOBLOCK_SIZE];  /* Driver info block encoding buffer */
diff --git a/src/H5Gdeprec.c b/src/H5Gdeprec.c
index ca9e7fd..8f2fe54 100644
--- a/src/H5Gdeprec.c
+++ b/src/H5Gdeprec.c
@@ -261,7 +261,7 @@ H5Gcreate1(hid_t loc_id, const char *name, size_t size_hint)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get group info")
 
         /* Set the non-default local heap size hint */
-        H5_ASSIGN_OVERFLOW(ginfo.lheap_size_hint, size_hint, size_t, uint32_t);
+        H5_CHECKED_ASSIGN(ginfo.lheap_size_hint, uint32_t, size_hint, size_t);
         if(H5P_set(gc_plist, H5G_CRT_GROUP_INFO_NAME, &ginfo) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set group info")
     } /* end if */
diff --git a/src/H5Glink.c b/src/H5Glink.c
index f934052..8b258b5 100644
--- a/src/H5Glink.c
+++ b/src/H5Glink.c
@@ -467,7 +467,7 @@ H5G__link_iterate_table(const H5G_link_table_t *ltable, hsize_t skip,
         *last_lnk += skip;
 
     /* Iterate over link messages */
-    H5_ASSIGN_OVERFLOW(/* To: */ u, /* From: */ skip, /* From: */ hsize_t, /* To: */ size_t)
+    H5_CHECKED_ASSIGN(u, size_t, skip, hsize_t)
     for(; u < ltable->nlinks && !ret_value; u++) {
         /* Make the callback */
         ret_value = (op)(&(ltable->lnks[u]), op_data);
diff --git a/src/H5HFdbg.c b/src/H5HFdbg.c
index 7d22ddd..8620f6f 100644
--- a/src/H5HFdbg.c
+++ b/src/H5HFdbg.c
@@ -387,11 +387,11 @@ H5HF_dblock_debug_cb(H5FS_section_info_t *_sect, void *_udata)
         if(sect_start < dblock_start)
             start = 0;
         else
-            H5_ASSIGN_OVERFLOW(/* To: */ start, /* From: */ (sect_start - dblock_start), /* From: */ hsize_t, /* To: */ size_t)
+            H5_CHECKED_ASSIGN(start, size_t, (sect_start - dblock_start), hsize_t)
         if(sect_end > dblock_end)
-            H5_ASSIGN_OVERFLOW(/* To: */ end, /* From: */ udata->dblock_size, /* From: */ hsize_t, /* To: */ size_t)
+            H5_CHECKED_ASSIGN(end, size_t, udata->dblock_size, hsize_t)
         else
-            H5_ASSIGN_OVERFLOW(/* To: */ end, /* From: */ ((sect_end - dblock_start) + 1), /* From: */ hsize_t, /* To: */ size_t)
+            H5_CHECKED_ASSIGN(end, size_t, ((sect_end - dblock_start) + 1), hsize_t)
 
         /* Calculate the length */
         len = end - start;
diff --git a/src/H5HFdblock.c b/src/H5HFdblock.c
index c4ae573..9a8da4a 100644
--- a/src/H5HFdblock.c
+++ b/src/H5HFdblock.c
@@ -131,7 +131,7 @@ H5HF_man_dblock_create(hid_t dxpl_id, H5HF_hdr_t *hdr, H5HF_indirect_t *par_iblo
         dblock->block_off = par_iblock->block_off;
         dblock->block_off += hdr->man_dtable.row_block_off[par_row];
         dblock->block_off += hdr->man_dtable.row_block_size[par_row] * (par_entry % hdr->man_dtable.cparam.width);
-        H5_ASSIGN_OVERFLOW(/* To: */ dblock->size, /* From: */ hdr->man_dtable.row_block_size[par_row], /* From: */ hsize_t, /* To: */ size_t);
+        H5_CHECKED_ASSIGN(dblock->size, size_t, hdr->man_dtable.row_block_size[par_row], hsize_t);
     } /* end if */
     else {
         /* Must be the root direct block */
@@ -397,7 +397,7 @@ H5HF_man_dblock_new(H5HF_hdr_t *hdr, hid_t dxpl_id, size_t request,
         if(H5HF_man_iter_curr(&hdr->next_block, &next_row, NULL, &next_entry, &iblock) < 0)
             HGOTO_ERROR(H5E_HEAP, H5E_CANTGET, FAIL, "unable to retrieve current block iterator location")
         HDassert(next_row < iblock->nrows);
-        H5_ASSIGN_OVERFLOW(/* To: */ next_size, /* From: */ hdr->man_dtable.row_block_size[next_row], /* From: */ hsize_t, /* To: */ size_t);
+        H5_CHECKED_ASSIGN(next_size, size_t, hdr->man_dtable.row_block_size[next_row], hsize_t);
 
         /* Check for skipping over blocks */
         if(min_dblock_size > next_size) {
diff --git a/src/H5HFdtable.c b/src/H5HFdtable.c
index 607862a..c523396 100644
--- a/src/H5HFdtable.c
+++ b/src/H5HFdtable.c
@@ -168,7 +168,7 @@ HDfprintf(stderr, "%s: off = %Hu\n", "H5HF_dtable_lookup", off);
     /* Check for offset in first row */
     if(off < dtable->num_id_first_row) {
         *row = 0;
-        H5_ASSIGN_OVERFLOW(/* To: */ *col, /* From: */ (off / dtable->cparam.start_block_size), /* From: */ hsize_t, /* To: */ unsigned);
+        H5_CHECKED_ASSIGN(*col, unsigned, (off / dtable->cparam.start_block_size), hsize_t);
     } /* end if */
     else {
         unsigned high_bit = H5VM_log2_gen(off);  /* Determine the high bit in the offset */
@@ -178,7 +178,7 @@ HDfprintf(stderr, "%s: off = %Hu\n", "H5HF_dtable_lookup", off);
 HDfprintf(stderr, "%s: high_bit = %u, off_mask = %Hu\n", "H5HF_dtable_lookup", high_bit, off_mask);
 #endif /* QAK */
         *row = (high_bit - dtable->first_row_bits) + 1;
-        H5_ASSIGN_OVERFLOW(/* To: */ *col, /* From: */ ((off - off_mask) / dtable->row_block_size[*row]), /* From: */ hsize_t, /* To: */ unsigned);
+        H5_CHECKED_ASSIGN(*col, unsigned, ((off - off_mask) / dtable->row_block_size[*row]), hsize_t);
     } /* end else */
 
     FUNC_LEAVE_NOAPI(SUCCEED)
diff --git a/src/H5HFhdr.c b/src/H5HFhdr.c
index d3c4473..cf8da23 100644
--- a/src/H5HFhdr.c
+++ b/src/H5HFhdr.c
@@ -262,7 +262,7 @@ H5HF_hdr_finish_init_phase2(H5HF_hdr_t *hdr)
         if(u < hdr->man_dtable.max_direct_rows) {
             hdr->man_dtable.row_tot_dblock_free[u] = hdr->man_dtable.row_block_size[u] -
                     H5HF_MAN_ABS_DIRECT_OVERHEAD(hdr);
-            H5_ASSIGN_OVERFLOW(/* To: */ hdr->man_dtable.row_max_dblock_free[u], /* From: */ hdr->man_dtable.row_tot_dblock_free[u], /* From: */ hsize_t, /* To: */ size_t);
+            H5_CHECKED_ASSIGN(hdr->man_dtable.row_max_dblock_free[u], size_t, hdr->man_dtable.row_tot_dblock_free[u], hsize_t);
         } /* end if */
         else
             if(H5HF_hdr_compute_free_space(hdr, u) < 0)
diff --git a/src/H5HFhuge.c b/src/H5HFhuge.c
index 6f0b48e..7f0da02 100644
--- a/src/H5HFhuge.c
+++ b/src/H5HFhuge.c
@@ -653,7 +653,7 @@ H5HF_huge_op_real(H5HF_hdr_t *hdr, hid_t dxpl_id, const uint8_t *id,
 
             /* Retrieve the object's address & length */
             obj_addr = found_rec.addr;
-            H5_ASSIGN_OVERFLOW(/* To: */ obj_size, /* From: */ found_rec.len, /* From: */ hsize_t, /* To: */ size_t);
+            H5_CHECKED_ASSIGN(obj_size, size_t, found_rec.len, hsize_t);
             filter_mask = found_rec.filter_mask;
         } /* end if */
         else {
@@ -669,7 +669,7 @@ H5HF_huge_op_real(H5HF_hdr_t *hdr, hid_t dxpl_id, const uint8_t *id,
 
             /* Retrieve the object's address & length */
             obj_addr = found_rec.addr;
-            H5_ASSIGN_OVERFLOW(/* To: */ obj_size, /* From: */ found_rec.len, /* From: */ hsize_t, /* To: */ size_t);
+            H5_CHECKED_ASSIGN(obj_size, size_t, found_rec.len, hsize_t);
         } /* end else */
     } /* end else */
 
@@ -797,7 +797,7 @@ H5HF_huge_write(H5HF_hdr_t *hdr, hid_t dxpl_id, const uint8_t *id,
 
         /* Retrieve the object's address & length */
         obj_addr = found_rec.addr;
-        H5_ASSIGN_OVERFLOW(/* To: */ obj_size, /* From: */ found_rec.len, /* From: */ hsize_t, /* To: */ size_t);
+        H5_CHECKED_ASSIGN(obj_size, size_t, found_rec.len, hsize_t);
     } /* end else */
 
     /* Write the object's data to the file */
diff --git a/src/H5HLcache.c b/src/H5HLcache.c
index a3c43ac..6576284 100644
--- a/src/H5HLcache.c
+++ b/src/H5HLcache.c
@@ -258,6 +258,7 @@ H5HL_prefix_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *_udata)
     size_t	        spec_read_size; /* Size of buffer to speculatively read in */
     const uint8_t	*p;         /* Pointer into decoding buffer */
     haddr_t             eoa;        /* Relative end of file address */
+    hsize_t min;                    /* temp min value to avoid macro nesting */
     H5HL_prfx_t *ret_value;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -276,7 +277,8 @@ H5HL_prefix_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *_udata)
         HGOTO_ERROR(H5E_HEAP, H5E_CANTGET, NULL, "unable to determine file size")
 
     /* Compute the size of the speculative local heap prefix buffer */
-    H5_ASSIGN_OVERFLOW(spec_read_size, MIN(eoa - addr, H5HL_SPEC_READ_SIZE), /* From: */ hsize_t, /* To: */ size_t);
+    min = MIN(eoa - addr, H5HL_SPEC_READ_SIZE);
+    H5_CHECKED_ASSIGN(spec_read_size, size_t, min, hsize_t);
     HDassert(spec_read_size >= udata->sizeof_prfx);
 
     /* Attempt to speculatively read both local heap prefix and heap data */
diff --git a/src/H5I.c b/src/H5I.c
index eb34d6e..528be81 100644
--- a/src/H5I.c
+++ b/src/H5I.c
@@ -433,7 +433,7 @@ H5Inmembers(H5I_type_t type, hsize_t *num_members)
         if((members = H5I_nmembers(type)) < 0)
             HGOTO_ERROR(H5E_ATOM, H5E_CANTCOUNT, FAIL, "can't compute number of members")
 
-        H5_ASSIGN_OVERFLOW(*num_members, members, int64_t, hsize_t);
+        H5_CHECKED_ASSIGN(*num_members, hsize_t, members, int64_t);
     } /* end if */
 
 done:
@@ -460,7 +460,7 @@ int64_t
 H5I_nmembers(H5I_type_t type)
 {
     H5I_id_type_t	*type_ptr = NULL;
-    int		ret_value;
+    int64_t		    ret_value;
 
     FUNC_ENTER_NOAPI(FAIL)
 
@@ -470,7 +470,7 @@ H5I_nmembers(H5I_type_t type)
 	HGOTO_DONE(0);
 
     /* Set return value */
-    H5_ASSIGN_OVERFLOW(ret_value, type_ptr->id_count, uint64_t, int64_t);
+    H5_CHECKED_ASSIGN(ret_value, int64_t, type_ptr->id_count, uint64_t);
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
diff --git a/src/H5MF.c b/src/H5MF.c
index 29e9ece..eecd724 100644
--- a/src/H5MF.c
+++ b/src/H5MF.c
@@ -1383,7 +1383,7 @@ H5MF_get_free_sections(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type, size_t nsects,
             /* Query how many sections of this type */
 	    if(H5FS_sect_stats(f->shared->fs_man[ty], NULL, &hnums) < 0)
 		HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't query free space stats")
-            H5_ASSIGN_OVERFLOW(nums, hnums, hsize_t, size_t);
+            H5_CHECKED_ASSIGN(nums, size_t, hnums, hsize_t);
 
             /* Increment total # of sections */
             total_sects += nums;
diff --git a/src/H5O.c b/src/H5O.c
index 1fd7225..6745716 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -2716,8 +2716,8 @@ H5O_get_hdr_info_real(const H5O_t *oh, H5O_hdr_info_t *hdr)
     hdr->version = oh->version;
 
     /* Set the number of messages & chunks */
-    H5_ASSIGN_OVERFLOW(hdr->nmesgs, oh->nmesgs, size_t, unsigned);
-    H5_ASSIGN_OVERFLOW(hdr->nchunks, oh->nchunks, size_t, unsigned);
+    H5_CHECKED_ASSIGN(hdr->nmesgs, unsigned, oh->nmesgs, size_t);
+    H5_CHECKED_ASSIGN(hdr->nchunks, unsigned, oh->nchunks, size_t);
 
     /* Set the status flags */
     hdr->flags = oh->flags;
diff --git a/src/H5Oattr.c b/src/H5Oattr.c
index 2269bd3..9710f5d 100644
--- a/src/H5Oattr.c
+++ b/src/H5Oattr.c
@@ -218,7 +218,7 @@ H5O_attr_decode(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh, unsigned UNUSED mesg_fl
         p += attr->shared->ds_size;
 
     /* Compute the size of the data */
-    H5_ASSIGN_OVERFLOW(attr->shared->data_size, H5S_GET_EXTENT_NPOINTS(attr->shared->ds) * H5T_get_size(attr->shared->dt), hsize_t, size_t);
+    H5_CHECKED_ASSIGN(attr->shared->data_size, size_t, H5S_GET_EXTENT_NPOINTS(attr->shared->ds) * H5T_get_size(attr->shared->dt), hsize_t);
 
     /* Go get the data */
     if(attr->shared->data_size) {
diff --git a/src/H5Ocache.c b/src/H5Ocache.c
index b3dea03..b1d94d8 100644
--- a/src/H5Ocache.c
+++ b/src/H5Ocache.c
@@ -184,7 +184,7 @@ H5O_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *_udata)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, NULL, "unable to determine file size")
 
     /* Compute the size of the speculative object header buffer */
-    H5_ASSIGN_OVERFLOW(spec_read_size, MIN(eoa - addr, H5O_SPEC_READ_SIZE), /* From: */ hsize_t, /* To: */ size_t);
+    H5_CHECKED_ASSIGN(spec_read_size, size_t, MIN(eoa - addr, H5O_SPEC_READ_SIZE), hsize_t);
 
     /* Attempt to speculatively read both object header prefix and first chunk */
     if(H5F_block_read(f, H5FD_MEM_OHDR, addr, spec_read_size, dxpl_id, read_buf) < 0)
diff --git a/src/H5Ofill.c b/src/H5Ofill.c
index a0fc42e..33022fc 100644
--- a/src/H5Ofill.c
+++ b/src/H5Ofill.c
@@ -977,7 +977,7 @@ H5O_fill_convert(H5O_fill_t *fill, H5T_t *dset_type, hbool_t *fill_changed, hid_
         } /* end if */
         H5T_close(fill->type);
         fill->type = NULL;
-        H5_ASSIGN_OVERFLOW(fill->size, H5T_get_size(dset_type), size_t, ssize_t);
+        H5_CHECKED_ASSIGN(fill->size, ssize_t, H5T_get_size(dset_type), size_t);
 
         /* Note that the fill value info has changed */
         *fill_changed = TRUE;
diff --git a/src/H5Omessage.c b/src/H5Omessage.c
index 1369583..f70fa72 100644
--- a/src/H5Omessage.c
+++ b/src/H5Omessage.c
@@ -807,7 +807,7 @@ H5O_msg_count(const H5O_loc_t *loc, unsigned type_id, hid_t dxpl_id)
 
     /* Count the messages of the correct type */
     msg_count = H5O_msg_count_real(oh, type);
-    H5_ASSIGN_OVERFLOW(ret_value, msg_count, unsigned, int);
+    H5_CHECKED_ASSIGN(ret_value, int, msg_count, unsigned);
 
 done:
     if(oh && H5O_unprotect(loc, dxpl_id, oh, H5AC__NO_FLAGS_SET) < 0)
@@ -2300,7 +2300,7 @@ H5O_msg_get_chunkno(const H5O_loc_t *loc, unsigned type_id, hid_t dxpl_id)
         HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "message type not found")
 
     /* Set return value */
-    H5_ASSIGN_OVERFLOW(ret_value, idx_msg->chunkno, unsigned, int);
+    H5_CHECKED_ASSIGN(ret_value, int, idx_msg->chunkno, unsigned);
 
 done:
     if(oh && H5O_unprotect(loc, dxpl_id, oh, H5AC__NO_FLAGS_SET) < 0)
diff --git a/src/H5Pencdec.c b/src/H5Pencdec.c
index 3285ae3..bd0a260 100644
--- a/src/H5Pencdec.c
+++ b/src/H5Pencdec.c
@@ -509,7 +509,7 @@ H5P__decode_size_t(const void **_pp, void *_value)
 
     /* Decode the value */
     UINT64DECODE_VAR(*pp, enc_value, enc_size);
-    H5_ASSIGN_OVERFLOW(*value, enc_value, uint64_t, size_t);
+    H5_CHECKED_ASSIGN(*value, size_t, enc_value, uint64_t);
 
     FUNC_LEAVE_NOAPI(SUCCEED)
 } /* end H5P__decode_size_t() */
@@ -550,7 +550,7 @@ H5P__decode_hsize_t(const void **_pp, void *_value)
 
     /* Decode the value */
     UINT64DECODE_VAR(*pp, enc_value, enc_size);
-    H5_ASSIGN_OVERFLOW(*value, enc_value, uint64_t, hsize_t);
+    H5_CHECKED_ASSIGN(*value, hsize_t, enc_value, uint64_t);
 
     FUNC_LEAVE_NOAPI(SUCCEED)
 } /* end H5P__decode_hsize_t() */
diff --git a/src/H5Pgcpl.c b/src/H5Pgcpl.c
index b7d5106..1e3a278 100644
--- a/src/H5Pgcpl.c
+++ b/src/H5Pgcpl.c
@@ -179,7 +179,7 @@ H5Pset_local_heap_size_hint(hid_t plist_id, size_t size_hint)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get group info")
 
     /* Update field */
-    H5_ASSIGN_OVERFLOW(ginfo.lheap_size_hint, size_hint, size_t, uint32_t);
+    H5_CHECKED_ASSIGN(ginfo.lheap_size_hint, uint32_t, size_hint, size_t);
 
     /* Set value */
     if(H5P_set(plist, H5G_CRT_GROUP_INFO_NAME, &ginfo) < 0)
diff --git a/src/H5S.c b/src/H5S.c
index dd2bb0a..9b37797 100644
--- a/src/H5S.c
+++ b/src/H5S.c
@@ -1521,7 +1521,7 @@ H5S_encode(H5S_t *obj, unsigned char *buf, size_t *nalloc)
     /* Find out the size of buffer needed for selection */
     if((sselect_size = H5S_SELECT_SERIAL_SIZE(obj)) < 0)
 	HGOTO_ERROR(H5E_DATASPACE, H5E_BADSIZE, FAIL, "can't find dataspace selection size")
-    H5_ASSIGN_OVERFLOW(select_size, sselect_size, hssize_t, size_t);
+    H5_CHECKED_ASSIGN(select_size, size_t, sselect_size, hssize_t);
 
     /* Verify the size of buffer.  If it's not big enough, simply return the
      * right size without filling the buffer. */
diff --git a/src/H5Shyper.c b/src/H5Shyper.c
index 9b1562f..0d5e630 100644
--- a/src/H5Shyper.c
+++ b/src/H5Shyper.c
@@ -7635,7 +7635,7 @@ H5S_hyper_get_seq_list_gen(const H5S_t *space,H5S_sel_iter_t *iter,
         /* Finish the span in the fastest changing dimension */
 
         /* Compute the number of bytes to attempt in this span */
-        H5_ASSIGN_OVERFLOW(span_size,((curr_span->high-abs_arr[fast_dim])+1)*elem_size,hsize_t,size_t);
+        H5_CHECKED_ASSIGN(span_size, size_t, ((curr_span->high-abs_arr[fast_dim])+1)*elem_size, hsize_t);
 
         /* Check number of bytes against upper bounds allowed */
         if(span_size>io_bytes_left)
@@ -7778,7 +7778,7 @@ H5S_hyper_get_seq_list_gen(const H5S_t *space,H5S_sel_iter_t *iter,
             loc_off += curr_span->pstride;
 
             /* Compute the number of elements to attempt in this span */
-            H5_ASSIGN_OVERFLOW(span_size, curr_span->nelem, hsize_t, size_t);
+            H5_CHECKED_ASSIGN(span_size, size_t, curr_span->nelem, hsize_t);
 
             /* Check number of elements against upper bounds allowed */
             if(span_size >= io_bytes_left) {
@@ -8108,7 +8108,7 @@ H5S_hyper_get_seq_list_opt(const H5S_t *space, H5S_sel_iter_t *iter,
         loc += offset[u] * slab[u];
 
     /* Set the number of elements to write each time */
-    H5_ASSIGN_OVERFLOW(actual_elem, tdiminfo[fast_dim].block, hsize_t, size_t);
+    H5_CHECKED_ASSIGN(actual_elem, size_t, tdiminfo[fast_dim].block, hsize_t);
 
     /* Set the number of actual bytes */
     actual_bytes = actual_elem * elem_size;
@@ -8117,7 +8117,7 @@ H5S_hyper_get_seq_list_opt(const H5S_t *space, H5S_sel_iter_t *iter,
     fast_dim_start = tdiminfo[fast_dim].start;
     fast_dim_stride = tdiminfo[fast_dim].stride;
     fast_dim_block = tdiminfo[fast_dim].block;
-    H5_ASSIGN_OVERFLOW(fast_dim_buf_off, slab[fast_dim] * fast_dim_stride, hsize_t, size_t);
+    H5_CHECKED_ASSIGN(fast_dim_buf_off, size_t, slab[fast_dim] * fast_dim_stride, hsize_t);
     fast_dim_offset = (hsize_t)((hssize_t)fast_dim_start + sel_off[fast_dim]);
 
     /* Compute the number of blocks which would fit into the buffer */
@@ -8138,7 +8138,7 @@ H5S_hyper_get_seq_list_opt(const H5S_t *space, H5S_sel_iter_t *iter,
     /* Check if there is a partial row left (with full blocks) */
     if(tmp_count[fast_dim] > 0) {
         /* Get number of blocks in fastest dimension */
-        H5_ASSIGN_OVERFLOW(fast_dim_count, tdiminfo[fast_dim].count - tmp_count[fast_dim], hsize_t, size_t);
+        H5_CHECKED_ASSIGN(fast_dim_count, size_t, tdiminfo[fast_dim].count - tmp_count[fast_dim], hsize_t);
 
         /* Make certain this entire row will fit into buffer */
         fast_dim_count = MIN(fast_dim_count, tot_blk_count);
@@ -8223,7 +8223,7 @@ H5S_hyper_get_seq_list_opt(const H5S_t *space, H5S_sel_iter_t *iter,
     curr_rows = total_rows = (size_t)(tot_blk_count / tdiminfo[fast_dim].count);
 
     /* Reset copy of number of blocks in fastest dimension */
-    H5_ASSIGN_OVERFLOW(fast_dim_count, tdiminfo[fast_dim].count, hsize_t, size_t);
+    H5_CHECKED_ASSIGN(fast_dim_count, size_t, tdiminfo[fast_dim].count, hsize_t);
 
     /* Read in data until an entire sequence can't be written out any longer */
     while(curr_rows > 0) {
@@ -8528,7 +8528,7 @@ H5S_hyper_get_seq_list_single(const H5S_t *space, H5S_sel_iter_t *iter,
     tot_blk_count = MIN(tot_blk_count, maxseq);
 
     /* Set the number of elements to write each time */
-    H5_ASSIGN_OVERFLOW(actual_elem, fast_dim_block, hsize_t, size_t);
+    H5_CHECKED_ASSIGN(actual_elem, size_t, fast_dim_block, hsize_t);
 
     /* Check for blocks to operate on */
     if(tot_blk_count > 0) {
@@ -8785,10 +8785,10 @@ H5S_hyper_get_seq_list(const H5S_t *space, unsigned UNUSED flags, H5S_sel_iter_t
 
             /* Calculate the number of elements left in the sequence */
             if(tdiminfo[fast_dim].count == 1) {
-                H5_ASSIGN_OVERFLOW(leftover, tdiminfo[fast_dim].block - (iter->u.hyp.off[fast_dim] - tdiminfo[fast_dim].start), hsize_t, size_t);
+                H5_CHECKED_ASSIGN(leftover, size_t, tdiminfo[fast_dim].block - (iter->u.hyp.off[fast_dim] - tdiminfo[fast_dim].start), hsize_t);
             } /* end if */
             else {
-                H5_ASSIGN_OVERFLOW(leftover, tdiminfo[fast_dim].block - ((iter->u.hyp.off[fast_dim] - tdiminfo[fast_dim].start) % tdiminfo[fast_dim].stride), hsize_t, size_t);
+                H5_CHECKED_ASSIGN(leftover, size_t, tdiminfo[fast_dim].block - ((iter->u.hyp.off[fast_dim] - tdiminfo[fast_dim].start) % tdiminfo[fast_dim].stride), hsize_t);
             } /* end else */
 
             /* Make certain that we don't write too many */
@@ -8807,7 +8807,7 @@ H5S_hyper_get_seq_list(const H5S_t *space, unsigned UNUSED flags, H5S_sel_iter_t
 
             /* Add a new sequence */
             off[0] = loc;
-            H5_ASSIGN_OVERFLOW(len[0], actual_elem * elem_size, hsize_t, size_t);
+            H5_CHECKED_ASSIGN(len[0], size_t, actual_elem * elem_size, hsize_t);
 
             /* Increment sequence array locations */
             off++;
diff --git a/src/H5Smpio.c b/src/H5Smpio.c
index def7598..c2190b4 100644
--- a/src/H5Smpio.c
+++ b/src/H5Smpio.c
@@ -94,13 +94,13 @@ H5S_mpio_all_type(const H5S_t *space, size_t elmt_size,
     /* Just treat the entire extent as a block of bytes */
     if((snelmts = (hssize_t)H5S_GET_EXTENT_NPOINTS(space)) < 0)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "src dataspace has invalid selection")
-    H5_ASSIGN_OVERFLOW(nelmts, snelmts, hssize_t, hsize_t);
+    H5_CHECKED_ASSIGN(nelmts, hsize_t, snelmts, hssize_t);
 
     total_bytes = (hsize_t)elmt_size * nelmts;
 
     /* fill in the return values */
     *new_type = MPI_BYTE;
-    H5_ASSIGN_OVERFLOW(*count, total_bytes, hsize_t, int);
+    H5_CHECKED_ASSIGN(*count, int, total_bytes, hsize_t);
     *is_derived_type = FALSE;
 
 done:
@@ -388,7 +388,7 @@ H5S_mpio_permute_type(const H5S_t *space, size_t elmt_size, hsize_t **permute,
     sel_iter_init = TRUE;	/* Selection iteration info has been initialized */
 
     /* Set the number of elements to iterate over */
-    H5_ASSIGN_OVERFLOW(max_elem, num_points, hsize_t, size_t);
+    H5_CHECKED_ASSIGN(max_elem, size_t, num_points, hsize_t);
 
     /* Loop, while elements left in selection */
     u = 0;
diff --git a/src/H5Sselect.c b/src/H5Sselect.c
index a4f13d7..e04ae16 100644
--- a/src/H5Sselect.c
+++ b/src/H5Sselect.c
@@ -1304,7 +1304,7 @@ H5S_select_iterate(void *buf, hid_t type_id, const H5S_t *space, H5D_operator_t
     space_size[ndims] = elmt_size;
 
     /* Compute the maximum number of bytes required */
-    H5_ASSIGN_OVERFLOW(max_elem, nelmts, hssize_t, size_t);
+    H5_CHECKED_ASSIGN(max_elem, size_t, nelmts, hssize_t);
 
     /* Loop, while elements left in selection */
     while(max_elem > 0 && user_ret == 0) {
@@ -2063,7 +2063,7 @@ H5S_select_fill(const void *fill, size_t fill_size, const H5S_t *space, void *_b
         HGOTO_ERROR(H5E_DATASPACE, H5E_CANTCOUNT, FAIL, "can't get number of elements selected")
 
     /* Compute the number of bytes to process */
-    H5_ASSIGN_OVERFLOW(max_elem, nelmts, hssize_t, size_t);
+    H5_CHECKED_ASSIGN(max_elem, size_t, nelmts, hssize_t);
 
     /* Loop, while elements left in selection */
     while(max_elem > 0) {
diff --git a/src/H5Tarray.c b/src/H5Tarray.c
index c73b934..2e9dec0 100644
--- a/src/H5Tarray.c
+++ b/src/H5Tarray.c
@@ -202,7 +202,7 @@ H5T__array_create(H5T_t *base, unsigned ndims, const hsize_t dim[/* ndims */])
 
     /* Copy the array dimensions & compute the # of elements in the array */
     for(u = 0, ret_value->shared->u.array.nelem = 1; u < ndims; u++) {
-        H5_ASSIGN_OVERFLOW(ret_value->shared->u.array.dim[u], dim[u], hsize_t, size_t);
+        H5_CHECKED_ASSIGN(ret_value->shared->u.array.dim[u], size_t, dim[u], hsize_t);
         ret_value->shared->u.array.nelem *= (size_t)dim[u];
     } /* end for */
 
diff --git a/src/H5Tconv.c b/src/H5Tconv.c
index df85553..1c51b69 100644
--- a/src/H5Tconv.c
+++ b/src/H5Tconv.c
@@ -1952,7 +1952,7 @@ H5T_conv_struct_init(H5T_t *src, H5T_t *dst, H5T_cdata_t *cdata, hid_t dxpl_id)
             src2dst[i] = -1;
             for(j = 0; j < dst_nmembs; j++) {
                 if(!HDstrcmp(src->shared->u.compnd.memb[i].name, dst->shared->u.compnd.memb[j].name)) {
-                    H5_ASSIGN_OVERFLOW(src2dst[i],j,unsigned,int);
+                    H5_CHECKED_ASSIGN(src2dst[i], int, j, unsigned);
                     break;
                 } /* end if */
             } /* end for */
@@ -2187,16 +2187,16 @@ H5T__conv_struct(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t nelmts,
              * Direction of conversion and striding through background.
              */
             if(buf_stride) {
-                H5_ASSIGN_OVERFLOW(src_delta, buf_stride, size_t, ssize_t);
+                H5_CHECKED_ASSIGN(src_delta, ssize_t, buf_stride, size_t);
                 if(!bkg_stride) {
-                    H5_ASSIGN_OVERFLOW(bkg_delta, dst->shared->size, size_t, ssize_t);
+                    H5_CHECKED_ASSIGN(bkg_delta, ssize_t, dst->shared->size, size_t);
                 } /* end if */
                 else
-                    H5_ASSIGN_OVERFLOW(bkg_delta, bkg_stride, size_t, ssize_t);
+                    H5_CHECKED_ASSIGN(bkg_delta, ssize_t, bkg_stride, size_t);
             } /* end if */
             else if(dst->shared->size <= src->shared->size) {
-                H5_ASSIGN_OVERFLOW(src_delta, src->shared->size, size_t, ssize_t);
-                H5_ASSIGN_OVERFLOW(bkg_delta, dst->shared->size, size_t, ssize_t);
+                H5_CHECKED_ASSIGN(src_delta, ssize_t, src->shared->size, size_t);
+                H5_CHECKED_ASSIGN(bkg_delta, ssize_t, dst->shared->size, size_t);
             } /* end else-if */
             else {
                 H5_CHECK_OVERFLOW(src->shared->size, size_t, ssize_t);
@@ -2278,7 +2278,7 @@ H5T__conv_struct(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t nelmts,
 
             /* If the bkg_delta was set to -(dst->shared->size), make it positive now */
             if(buf_stride == 0 && dst->shared->size > src->shared->size)
-                H5_ASSIGN_OVERFLOW(bkg_delta, dst->shared->size, size_t, ssize_t);
+                H5_CHECKED_ASSIGN(bkg_delta, ssize_t, dst->shared->size, size_t);
 
             /*
              * Copy the background buffer back into the in-place conversion
@@ -2833,8 +2833,8 @@ H5T__conv_enum(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t nelmts,
                 src_delta = dst_delta = (ssize_t)buf_stride;
                 s = d = buf;
             } else if(dst->shared->size <= src->shared->size) {
-                H5_ASSIGN_OVERFLOW(src_delta, src->shared->size, size_t, ssize_t);
-                H5_ASSIGN_OVERFLOW(dst_delta, dst->shared->size, size_t, ssize_t);
+                H5_CHECKED_ASSIGN(src_delta, ssize_t, src->shared->size, size_t);
+                H5_CHECKED_ASSIGN(dst_delta, ssize_t, dst->shared->size, size_t);
                 s = d = buf;
             } else {
                 H5_CHECK_OVERFLOW(src->shared->size, size_t, ssize_t);
diff --git a/src/H5Tfloat.c b/src/H5Tfloat.c
index 7d08d62..fff413d 100644
--- a/src/H5Tfloat.c
+++ b/src/H5Tfloat.c
@@ -203,7 +203,7 @@ H5Tget_ebias(hid_t type_id)
 	HGOTO_ERROR(H5E_DATATYPE, H5E_BADTYPE, 0, "operation not defined for datatype class")
 
     /* bias */
-    H5_ASSIGN_OVERFLOW(ret_value, dt->shared->u.atomic.u.f.ebias, uint64_t, size_t);
+    H5_CHECKED_ASSIGN(ret_value, size_t, dt->shared->u.atomic.u.f.ebias, uint64_t);
 
 done:
     FUNC_LEAVE_API(ret_value)
diff --git a/src/H5Tnative.c b/src/H5Tnative.c
index 960a811..bf6ba08 100644
--- a/src/H5Tnative.c
+++ b/src/H5Tnative.c
@@ -276,7 +276,7 @@ H5T_get_native_type(H5T_t *dtype, H5T_direction_t direction, size_t *struct_alig
 
                 if((snmemb = H5T_get_nmembers(dtype)) <= 0)
                     HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "compound data type doesn't have any member")
-                H5_ASSIGN_OVERFLOW(nmemb, snmemb, int, unsigned);
+                H5_CHECKED_ASSIGN(nmemb, unsigned, snmemb, int);
 
                 if(NULL == (memb_list   = (H5T_t **)H5MM_calloc(nmemb * sizeof(H5T_t *))))
                     HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "cannot allocate memory")
@@ -388,7 +388,7 @@ H5T_get_native_type(H5T_t *dtype, H5T_direction_t direction, size_t *struct_alig
                 /* Retrieve member info and insert members into new enum type */
                 if((snmemb = H5T_get_nmembers(dtype)) <= 0)
                     HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "enumerate data type doesn't have any member")
-                H5_ASSIGN_OVERFLOW(nmemb, snmemb, int, unsigned);
+                H5_CHECKED_ASSIGN(nmemb, unsigned, snmemb, int);
                 for(u = 0; u < nmemb; u++) {
                     if(NULL == (memb_name = H5T__get_member_name(dtype, u)))
                         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "cannot get member name")
@@ -429,7 +429,7 @@ H5T_get_native_type(H5T_t *dtype, H5T_direction_t direction, size_t *struct_alig
                 /* Retrieve dimension information for array data type */
                 if((sarray_rank = H5T__get_array_ndims(dtype)) <= 0)
                     HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "cannot get dimension rank")
-                H5_ASSIGN_OVERFLOW(array_rank, sarray_rank, int, unsigned);
+                H5_CHECKED_ASSIGN(array_rank, unsigned, sarray_rank, int);
                 if(NULL == (dims = (hsize_t*)H5MM_malloc(array_rank * sizeof(hsize_t))))
                     HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "cannot allocate memory")
                 if(H5T__get_array_dims(dtype, dims) < 0)
diff --git a/src/H5Zdeflate.c b/src/H5Zdeflate.c
index 82ad1ba..06d9866 100644
--- a/src/H5Zdeflate.c
+++ b/src/H5Zdeflate.c
@@ -102,9 +102,9 @@ H5Z_filter_deflate (unsigned flags, size_t cd_nelmts,
         /* Set the uncompression parameters */
 	HDmemset(&z_strm, 0, sizeof(z_strm));
 	z_strm.next_in = (Bytef *)*buf;
-        H5_ASSIGN_OVERFLOW(z_strm.avail_in,nbytes,size_t,unsigned);
+        H5_CHECKED_ASSIGN(z_strm.avail_in, unsigned, nbytes, size_t);
 	z_strm.next_out = (Bytef *)outbuf;
-        H5_ASSIGN_OVERFLOW(z_strm.avail_out,nalloc,size_t,unsigned);
+        H5_CHECKED_ASSIGN(z_strm.avail_out, unsigned, nalloc, size_t);
 
         /* Initialize the uncompression routines */
 	if (Z_OK!=inflateInit(&z_strm))
@@ -169,7 +169,7 @@ H5Z_filter_deflate (unsigned flags, size_t cd_nelmts,
         int          aggression;     /* Compression aggression setting */
 
         /* Set the compression aggression level */
-        H5_ASSIGN_OVERFLOW(aggression,cd_values[0],unsigned,int);
+        H5_CHECKED_ASSIGN(aggression, int, cd_values[0], unsigned);
 
         /* Allocate output (compressed) buffer */
 	if(NULL == (outbuf = H5MM_malloc(z_dst_nbytes)))
diff --git a/src/H5Znbit.c b/src/H5Znbit.c
index 9506ace..ff3ead2 100644
--- a/src/H5Znbit.c
+++ b/src/H5Znbit.c
@@ -803,7 +803,7 @@ H5Z_set_local_nbit(hid_t dcpl_id, hid_t type_id, hid_t space_id)
     cd_values_index = 2;
 
     /* Set "local" parameter for number of elements in the chunk */
-    H5_ASSIGN_OVERFLOW(cd_values[cd_values_index++], npoints, hssize_t, unsigned);
+    H5_CHECKED_ASSIGN(cd_values[cd_values_index++], unsigned, npoints, hssize_t);
 
     /* Assume no need to compress now, will be changed to FALSE later if not */
     need_not_compress = TRUE;
diff --git a/src/H5Zscaleoffset.c b/src/H5Zscaleoffset.c
index 38e2986..cda0a11 100644
--- a/src/H5Zscaleoffset.c
+++ b/src/H5Zscaleoffset.c
@@ -901,7 +901,7 @@ H5Z_set_local_scaleoffset(hid_t dcpl_id, hid_t type_id, hid_t space_id)
         HGOTO_ERROR(H5E_PLINE, H5E_CANTGET, FAIL, "unable to get number of points in the dataspace")
 
     /* Set "local" parameter for this dataset's number of elements */
-    H5_ASSIGN_OVERFLOW(cd_values[H5Z_SCALEOFFSET_PARM_NELMTS],npoints,hssize_t,unsigned);
+    H5_CHECKED_ASSIGN(cd_values[H5Z_SCALEOFFSET_PARM_NELMTS], unsigned, npoints, hssize_t);
 
     /* Get datatype's class */
     if((dtype_class = H5T_get_class(type, TRUE)) == H5T_NO_CLASS)
diff --git a/src/H5Zszip.c b/src/H5Zszip.c
index 4544ec3..631667b 100644
--- a/src/H5Zszip.c
+++ b/src/H5Zszip.c
@@ -225,7 +225,7 @@ H5Z_set_local_szip(hid_t dcpl_id, hid_t type_id, hid_t space_id)
     } /* end else */
 
     /* Assign the final value to the scanline */
-    H5_ASSIGN_OVERFLOW(cd_values[H5Z_SZIP_PARM_PPS],scanline,hsize_t,unsigned);
+    H5_CHECKED_ASSIGN(cd_values[H5Z_SZIP_PARM_PPS], unsigned, scanline, hsize_t);
 
     /* Get datatype's endianness order */
     if((dtype_order = H5T_get_order(type)) == H5T_ORDER_ERROR)
@@ -301,10 +301,10 @@ H5Z_filter_szip (unsigned flags, size_t cd_nelmts, const unsigned cd_values[],
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, 0, "invalid deflate aggression level")
 
     /* Copy the filter parameters into the szip parameter block */
-    H5_ASSIGN_OVERFLOW(sz_param.options_mask,cd_values[H5Z_SZIP_PARM_MASK],unsigned,int);
-    H5_ASSIGN_OVERFLOW(sz_param.bits_per_pixel,cd_values[H5Z_SZIP_PARM_BPP],unsigned,int);
-    H5_ASSIGN_OVERFLOW(sz_param.pixels_per_block,cd_values[H5Z_SZIP_PARM_PPB],unsigned,int);
-    H5_ASSIGN_OVERFLOW(sz_param.pixels_per_scanline,cd_values[H5Z_SZIP_PARM_PPS],unsigned,int);
+    H5_CHECKED_ASSIGN(sz_param.options_mask, int, cd_values[H5Z_SZIP_PARM_MASK], unsigned);
+    H5_CHECKED_ASSIGN(sz_param.bits_per_pixel, int, cd_values[H5Z_SZIP_PARM_BPP], unsigned);
+    H5_CHECKED_ASSIGN(sz_param.pixels_per_block, int, cd_values[H5Z_SZIP_PARM_PPB], unsigned);
+    H5_CHECKED_ASSIGN(sz_param.pixels_per_scanline, int, cd_values[H5Z_SZIP_PARM_PPS], unsigned);
 
     /* Input; uncompress */
     if (flags & H5Z_FLAG_REVERSE) {
@@ -314,7 +314,7 @@ H5Z_filter_szip (unsigned flags, size_t cd_nelmts, const unsigned cd_values[],
         /* Get the size of the uncompressed buffer */
         newbuf = *buf;
         UINT32DECODE(newbuf,stored_nalloc);
-        H5_ASSIGN_OVERFLOW(nalloc,stored_nalloc,uint32_t,size_t);
+        H5_CHECKED_ASSIGN(nalloc, size_t, stored_nalloc, uint32_t);
 
         /* Allocate space for the uncompressed buffer */
         if(NULL==(outbuf = H5MM_malloc(nalloc)))
diff --git a/src/H5private.h b/src/H5private.h
index d1bbc24..66bf7eb 100644
--- a/src/H5private.h
+++ b/src/H5private.h
@@ -1523,11 +1523,14 @@ extern char *strdup(const char *s);
 /* Include the generated overflow header file */
 #include "H5overflow.h"
 
-#define H5_ASSIGN_OVERFLOW(dst, src, srctype, dsttype)  \
+/* Assign a variable to one of a different size (think safer dst = (dsttype)src").
+ * The code generated by the macro checks for overflows.
+ */
+#define H5_CHECKED_ASSIGN(dst, dsttype, src, srctype)  \
     H5_GLUE4(ASSIGN_,srctype,_TO_,dsttype)(dst,dsttype,src,srctype)\
 
 #else /* NDEBUG */
-#define H5_ASSIGN_OVERFLOW(dst, src, srctype, dsttype)  \
+#define H5_CHECKED_ASSIGN(dst, dsttype, src, srctype)  \
     (dst) = (dsttype)(src);
 #endif /* NDEBUG */