Fix some const cast and stack/static object size warnings (#1700)

* Fix various warnings

* Move HDfree_const to H5private.h for wider use

* Print output from all ranks in parallel tests on allocation failure

* Move const pointer freeing macro to h5test.h for now

10 files changed, 94 insertions, 61 deletions

diff --git a/src/H5Dchunk.c b/src/H5Dchunk.c
index 1d4b215..2075498 100644
--- a/src/H5Dchunk.c
+++ b/src/H5Dchunk.c
@@ -8089,13 +8089,13 @@ H5D__chunk_iter_cb(const H5D_chunk_rec_t *chunk_rec, void *udata)
  *-------------------------------------------------------------------------
  */
 herr_t
-H5D__chunk_iter(const H5D_t *dset, H5D_chunk_iter_op_t op, void *op_data)
+H5D__chunk_iter(H5D_t *dset, H5D_chunk_iter_op_t op, void *op_data)
 {
-    const H5O_layout_t *layout = NULL;       /* Dataset layout */
-    const H5D_rdcc_t *  rdcc   = NULL;       /* Raw data chunk cache */
-    H5D_rdcc_ent_t *    ent;                 /* Cache entry index */
-    H5D_chk_idx_info_t  idx_info;            /* Chunked index info */
-    herr_t              ret_value = SUCCEED; /* Return value */
+    const H5D_rdcc_t * rdcc   = NULL;       /* Raw data chunk cache */
+    H5O_layout_t *     layout = NULL;       /* Dataset layout */
+    H5D_rdcc_ent_t *   ent;                 /* Cache entry index */
+    H5D_chk_idx_info_t idx_info;            /* Chunked index info */
+    herr_t             ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_PACKAGE_TAG(dset->oloc.addr)
 
diff --git a/src/H5Dmpio.c b/src/H5Dmpio.c
index a7908fe..0620459 100644
--- a/src/H5Dmpio.c
+++ b/src/H5Dmpio.c
@@ -302,7 +302,7 @@ static herr_t H5D__link_chunk_collective_io(H5D_io_info_t *io_info, const H5D_ty
 static herr_t H5D__link_chunk_filtered_collective_io(H5D_io_info_t *io_info, const H5D_type_info_t *type_info,
                                                      H5D_chunk_map_t *fm, int mpi_rank, int mpi_size);
 static herr_t H5D__inter_collective_io(H5D_io_info_t *io_info, const H5D_type_info_t *type_info,
-                                       const H5S_t *file_space, const H5S_t *mem_space);
+                                       H5S_t *file_space, H5S_t *mem_space);
 static herr_t H5D__final_collective_io(H5D_io_info_t *io_info, const H5D_type_info_t *type_info,
                                        hsize_t nelmts, MPI_Datatype mpi_file_type, MPI_Datatype mpi_buf_type);
 static herr_t H5D__sort_chunk(H5D_io_info_t *io_info, const H5D_chunk_map_t *fm,
@@ -2372,8 +2372,8 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5D__inter_collective_io(H5D_io_info_t *io_info, const H5D_type_info_t *type_info, const H5S_t *file_space,
-                         const H5S_t *mem_space)
+H5D__inter_collective_io(H5D_io_info_t *io_info, const H5D_type_info_t *type_info, H5S_t *file_space,
+                         H5S_t *mem_space)
 {
     int          mpi_buf_count; /* # of MPI types */
     hbool_t      mbt_is_derived = FALSE;
diff --git a/src/H5Dpkg.h b/src/H5Dpkg.h
index 724f3ce..3df9dde 100644
--- a/src/H5Dpkg.h
+++ b/src/H5Dpkg.h
@@ -566,7 +566,7 @@ H5_DLL herr_t  H5D__get_chunk_info(const H5D_t *dset, const H5S_t *space, hsize_
                                    unsigned *filter_mask, haddr_t *offset, hsize_t *size);
 H5_DLL herr_t  H5D__get_chunk_info_by_coord(const H5D_t *dset, const hsize_t *coord, unsigned *filter_mask,
                                             haddr_t *addr, hsize_t *size);
-H5_DLL herr_t  H5D__chunk_iter(const H5D_t *dset, H5D_chunk_iter_op_t cb, void *op_data);
+H5_DLL herr_t  H5D__chunk_iter(H5D_t *dset, H5D_chunk_iter_op_t cb, void *op_data);
 H5_DLL haddr_t H5D__get_offset(const H5D_t *dset);
 H5_DLL herr_t  H5D__vlen_get_buf_size(H5D_t *dset, hid_t type_id, hid_t space_id, hsize_t *size);
 H5_DLL herr_t  H5D__vlen_get_buf_size_gen(H5VL_object_t *vol_obj, hid_t type_id, hid_t space_id,
diff --git a/src/H5Shyper.c b/src/H5Shyper.c
index 7b87d7b..86aaef2 100644
--- a/src/H5Shyper.c
+++ b/src/H5Shyper.c
@@ -160,7 +160,7 @@ static herr_t  H5S__hyper_iter_get_seq_list_opt(H5S_sel_iter_t *iter, size_t max
 static herr_t  H5S__hyper_iter_get_seq_list_single(H5S_sel_iter_t *iter, size_t maxseq, size_t maxelem,
                                                    size_t *nseq, size_t *nelem, hsize_t *off, size_t *len);
 static herr_t  H5S__hyper_proj_int_build_proj(H5S_hyper_project_intersect_ud_t *udata);
-static herr_t  H5S__hyper_proj_int_iterate(const H5S_hyper_span_info_t *ss_span_info,
+static herr_t  H5S__hyper_proj_int_iterate(H5S_hyper_span_info_t *      ss_span_info,
                                            const H5S_hyper_span_info_t *sis_span_info, hsize_t count,
                                            unsigned depth, H5S_hyper_project_intersect_ud_t *udata);
 static void    H5S__hyper_get_clip_diminfo(hsize_t start, hsize_t stride, hsize_t *count, hsize_t *block,
@@ -11332,9 +11332,8 @@ sis_span_info unsigned depth;         IN: Depth of iteration (in terms of rank)
  REVISION LOG
 --------------------------------------------------------------------------*/
 static herr_t
-H5S__hyper_proj_int_iterate(const H5S_hyper_span_info_t *ss_span_info,
-                            const H5S_hyper_span_info_t *sis_span_info, hsize_t count, unsigned depth,
-                            H5S_hyper_project_intersect_ud_t *udata)
+H5S__hyper_proj_int_iterate(H5S_hyper_span_info_t *ss_span_info, const H5S_hyper_span_info_t *sis_span_info,
+                            hsize_t count, unsigned depth, H5S_hyper_project_intersect_ud_t *udata)
 {
     const H5S_hyper_span_t *ss_span;             /* Current span in source space */
     const H5S_hyper_span_t *sis_span;            /* Current span in source intersect space */
@@ -11597,7 +11596,7 @@ H5S__hyper_project_intersection(H5S_t *src_space, H5S_t *dst_space, H5S_t *src_i
                                 H5S_t *proj_space, hbool_t share_selection)
 {
     H5S_hyper_project_intersect_ud_t udata; /* User data for subroutines */
-    const H5S_hyper_span_info_t *    ss_span_info;
+    H5S_hyper_span_info_t *          ss_span_info;
     const H5S_hyper_span_info_t *    ds_span_info;
     H5S_hyper_span_info_t *          ss_span_info_buf = NULL;
     H5S_hyper_span_info_t *          ds_span_info_buf = NULL;
diff --git a/src/H5Smpio.c b/src/H5Smpio.c
index 0c14129..a9108a5 100644
--- a/src/H5Smpio.c
+++ b/src/H5Smpio.c
@@ -73,10 +73,10 @@ static herr_t H5S__mpio_create_point_datatype(size_t elmt_size, hsize_t num_poin
 static herr_t H5S__mpio_point_type(const H5S_t *space, size_t elmt_size, MPI_Datatype *new_type, int *count,
                                    hbool_t *is_derived_type, hbool_t do_permute, hsize_t **permute_map,
                                    hbool_t *is_permuted);
-static herr_t H5S__mpio_permute_type(const H5S_t *space, size_t elmt_size, hsize_t **permute_map,
+static herr_t H5S__mpio_permute_type(H5S_t *space, size_t elmt_size, hsize_t **permute_map,
                                      MPI_Datatype *new_type, int *count, hbool_t *is_derived_type);
-static herr_t H5S__mpio_reg_hyper_type(const H5S_t *space, size_t elmt_size, MPI_Datatype *new_type,
-                                       int *count, hbool_t *is_derived_type);
+static herr_t H5S__mpio_reg_hyper_type(H5S_t *space, size_t elmt_size, MPI_Datatype *new_type, int *count,
+                                       hbool_t *is_derived_type);
 static herr_t H5S__mpio_span_hyper_type(const H5S_t *space, size_t elmt_size, MPI_Datatype *new_type,
                                         int *count, hbool_t *is_derived_type);
 static herr_t H5S__release_datatype(H5S_mpio_mpitype_list_t *type_list);
@@ -95,6 +95,9 @@ static herr_t H5S__obtain_datatype(H5S_hyper_span_info_t *spans, const hsize_t *
 /* Declare a free list to manage the H5S_mpio_mpitype_node_t struct */
 H5FL_DEFINE_STATIC(H5S_mpio_mpitype_node_t);
 
+/* Declare a free list to manage dataspace selection iterators */
+H5FL_EXTERN(H5S_sel_iter_t);
+
 /*-------------------------------------------------------------------------
  * Function:	H5S__mpio_all_type
  *
@@ -501,17 +504,19 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5S__mpio_permute_type(const H5S_t *space, size_t elmt_size, hsize_t **permute, MPI_Datatype *new_type,
-                       int *count, hbool_t *is_derived_type)
+H5S__mpio_permute_type(H5S_t *space, size_t elmt_size, hsize_t **permute, MPI_Datatype *new_type, int *count,
+                       hbool_t *is_derived_type)
 {
-    MPI_Aint *     disp = NULL;           /* Datatype displacement for each point*/
-    H5S_sel_iter_t sel_iter;              /* Selection iteration info */
-    hbool_t        sel_iter_init = FALSE; /* Selection iteration info has been initialized */
-    hssize_t       snum_points;           /* Signed number of elements in selection */
-    hsize_t        num_points;            /* Number of points in the selection */
-    size_t         max_elem;              /* Maximum number of elements allowed in sequences */
-    hsize_t        u;                     /* Local index variable */
-    herr_t         ret_value = SUCCEED;   /* Return value */
+    MPI_Aint *      disp          = NULL;  /* Datatype displacement for each point*/
+    H5S_sel_iter_t *sel_iter      = NULL;  /* Selection iteration info */
+    hbool_t         sel_iter_init = FALSE; /* Selection iteration info has been initialized */
+    hssize_t        snum_points;           /* Signed number of elements in selection */
+    hsize_t         num_points;            /* Number of points in the selection */
+    hsize_t *       off = NULL;
+    size_t *        len = NULL;
+    size_t          max_elem;            /* Maximum number of elements allowed in sequences */
+    hsize_t         u;                   /* Local index variable */
+    herr_t          ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_PACKAGE
 
@@ -527,8 +532,18 @@ H5S__mpio_permute_type(const H5S_t *space, size_t elmt_size, hsize_t **permute,
     if (NULL == (disp = (MPI_Aint *)H5MM_malloc(sizeof(MPI_Aint) * num_points)))
         HGOTO_ERROR(H5E_DATASPACE, H5E_CANTALLOC, FAIL, "can't allocate array of displacements")
 
+    /* Allocate arrays to hold sequence offsets and lengths */
+    if (NULL == (off = H5MM_malloc(H5D_IO_VECTOR_SIZE * sizeof(*off))))
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "can't allocate sequence offsets array")
+    if (NULL == (len = H5MM_malloc(H5D_IO_VECTOR_SIZE * sizeof(*len))))
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "can't allocate sequence lengths array")
+
+    /* Allocate a selection iterator for iterating over the dataspace */
+    if (NULL == (sel_iter = H5FL_MALLOC(H5S_sel_iter_t)))
+        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTALLOC, FAIL, "couldn't allocate dataspace selection iterator")
+
     /* Initialize selection iterator */
-    if (H5S_select_iter_init(&sel_iter, space, elmt_size, 0) < 0)
+    if (H5S_select_iter_init(sel_iter, space, elmt_size, 0) < 0)
         HGOTO_ERROR(H5E_DATASPACE, H5E_CANTINIT, FAIL, "unable to initialize selection iterator")
     sel_iter_init = TRUE; /* Selection iteration info has been initialized */
 
@@ -538,14 +553,12 @@ H5S__mpio_permute_type(const H5S_t *space, size_t elmt_size, hsize_t **permute,
     /* Loop, while elements left in selection */
     u = 0;
     while (max_elem > 0) {
-        hsize_t off[H5D_IO_VECTOR_SIZE]; /* Array to store sequence offsets */
-        size_t  len[H5D_IO_VECTOR_SIZE]; /* Array to store sequence lengths */
-        size_t  nelem;                   /* Number of elements used in sequences */
-        size_t  nseq;                    /* Number of sequences generated */
-        size_t  curr_seq;                /* Current sequence being worked on */
+        size_t nelem;    /* Number of elements used in sequences */
+        size_t nseq;     /* Number of sequences generated */
+        size_t curr_seq; /* Current sequence being worked on */
 
         /* Get the sequences of bytes */
-        if (H5S_SELECT_ITER_GET_SEQ_LIST(&sel_iter, (size_t)H5D_IO_VECTOR_SIZE, max_elem, &nseq, &nelem, off,
+        if (H5S_SELECT_ITER_GET_SEQ_LIST(sel_iter, (size_t)H5D_IO_VECTOR_SIZE, max_elem, &nseq, &nelem, off,
                                          len) < 0)
             HGOTO_ERROR(H5E_DATASPACE, H5E_UNSUPPORTED, FAIL, "sequence length generation failed")
 
@@ -602,9 +615,14 @@ H5S__mpio_permute_type(const H5S_t *space, size_t elmt_size, hsize_t **permute,
 
 done:
     /* Release selection iterator */
-    if (sel_iter_init)
-        if (H5S_SELECT_ITER_RELEASE(&sel_iter) < 0)
+    if (sel_iter) {
+        if (sel_iter_init && H5S_SELECT_ITER_RELEASE(sel_iter) < 0)
             HDONE_ERROR(H5E_DATASPACE, H5E_CANTRELEASE, FAIL, "unable to release selection iterator")
+        sel_iter = H5FL_FREE(H5S_sel_iter_t, sel_iter);
+    }
+
+    H5MM_free(len);
+    H5MM_free(off);
 
     /* Free memory */
     if (disp)
@@ -634,11 +652,11 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5S__mpio_reg_hyper_type(const H5S_t *space, size_t elmt_size, MPI_Datatype *new_type, int *count,
+H5S__mpio_reg_hyper_type(H5S_t *space, size_t elmt_size, MPI_Datatype *new_type, int *count,
                          hbool_t *is_derived_type)
 {
-    H5S_sel_iter_t sel_iter;              /* Selection iteration info */
-    hbool_t        sel_iter_init = FALSE; /* Selection iteration info has been initialized */
+    H5S_sel_iter_t *sel_iter      = NULL;  /* Selection iteration info */
+    hbool_t         sel_iter_init = FALSE; /* Selection iteration info has been initialized */
 
     struct dim { /* less hassle than malloc/free & ilk */
         hssize_t start;
@@ -668,32 +686,37 @@ H5S__mpio_reg_hyper_type(const H5S_t *space, size_t elmt_size, MPI_Datatype *new
     HDassert(sizeof(MPI_Aint) >= sizeof(elmt_size));
 
     bigio_count = H5_mpi_get_bigio_count();
+
+    /* Allocate a selection iterator for iterating over the dataspace */
+    if (NULL == (sel_iter = H5FL_MALLOC(H5S_sel_iter_t)))
+        HGOTO_ERROR(H5E_DATASPACE, H5E_CANTALLOC, FAIL, "couldn't allocate dataspace selection iterator")
+
     /* Initialize selection iterator */
-    if (H5S_select_iter_init(&sel_iter, space, elmt_size, 0) < 0)
+    if (H5S_select_iter_init(sel_iter, space, elmt_size, 0) < 0)
         HGOTO_ERROR(H5E_DATASPACE, H5E_CANTINIT, FAIL, "unable to initialize selection iterator")
     sel_iter_init = TRUE; /* Selection iteration info has been initialized */
 
     /* Abbreviate args */
-    diminfo = sel_iter.u.hyp.diminfo;
+    diminfo = sel_iter->u.hyp.diminfo;
     HDassert(diminfo);
 
     /* Make a local copy of the dimension info so we can operate with them */
 
     /* Check if this is a "flattened" regular hyperslab selection */
-    if (sel_iter.u.hyp.iter_rank != 0 && sel_iter.u.hyp.iter_rank < space->extent.rank) {
+    if (sel_iter->u.hyp.iter_rank != 0 && sel_iter->u.hyp.iter_rank < space->extent.rank) {
         /* Flattened selection */
-        rank = sel_iter.u.hyp.iter_rank;
+        rank = sel_iter->u.hyp.iter_rank;
 #ifdef H5S_DEBUG
         if (H5DEBUG(S))
             HDfprintf(H5DEBUG(S), "%s: Flattened selection\n", __func__);
 #endif
         for (u = 0; u < rank; ++u) {
             H5_CHECK_OVERFLOW(diminfo[u].start, hsize_t, hssize_t)
-            d[u].start = (hssize_t)diminfo[u].start + sel_iter.u.hyp.sel_off[u];
+            d[u].start = (hssize_t)diminfo[u].start + sel_iter->u.hyp.sel_off[u];
             d[u].strid = diminfo[u].stride;
             d[u].block = diminfo[u].block;
             d[u].count = diminfo[u].count;
-            d[u].xtent = sel_iter.u.hyp.size[u];
+            d[u].xtent = sel_iter->u.hyp.size[u];
 
 #ifdef H5S_DEBUG
             if (H5DEBUG(S)) {
@@ -951,9 +974,11 @@ H5S__mpio_reg_hyper_type(const H5S_t *space, size_t elmt_size, MPI_Datatype *new
 
 done:
     /* Release selection iterator */
-    if (sel_iter_init)
-        if (H5S_SELECT_ITER_RELEASE(&sel_iter) < 0)
+    if (sel_iter) {
+        if (sel_iter_init && H5S_SELECT_ITER_RELEASE(sel_iter) < 0)
             HDONE_ERROR(H5E_DATASPACE, H5E_CANTRELEASE, FAIL, "unable to release selection iterator")
+        sel_iter = H5FL_FREE(H5S_sel_iter_t, sel_iter);
+    }
 
 #ifdef H5S_DEBUG
     if (H5DEBUG(S))
@@ -1364,7 +1389,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5S_mpio_space_type(const H5S_t *space, size_t elmt_size, MPI_Datatype *new_type, int *count,
+H5S_mpio_space_type(H5S_t *space, size_t elmt_size, MPI_Datatype *new_type, int *count,
                     hbool_t *is_derived_type, hbool_t do_permute, hsize_t **permute_map, hbool_t *is_permuted)
 {
     herr_t ret_value = SUCCEED; /* Return value */
diff --git a/src/H5Sprivate.h b/src/H5Sprivate.h
index 4c997b1..2c31ba9 100644
--- a/src/H5Sprivate.h
+++ b/src/H5Sprivate.h
@@ -299,7 +299,7 @@ H5_DLL herr_t H5S_select_iter_release(H5S_sel_iter_t *sel_iter);
 H5_DLL herr_t H5S_sel_iter_close(H5S_sel_iter_t *sel_iter);
 
 #ifdef H5_HAVE_PARALLEL
-H5_DLL herr_t H5S_mpio_space_type(const H5S_t *space, size_t elmt_size,
+H5_DLL herr_t H5S_mpio_space_type(H5S_t *space, size_t elmt_size,
                                   /* out: */ MPI_Datatype *new_type, int *count, hbool_t *is_derived_type,
                                   hbool_t do_permute, hsize_t **permute_map, hbool_t *is_permuted);
 #endif /* H5_HAVE_PARALLEL */
diff --git a/src/H5Tconv.c b/src/H5Tconv.c
index 26ecff5..da98182 100644
--- a/src/H5Tconv.c
+++ b/src/H5Tconv.c
@@ -3406,8 +3406,8 @@ H5T__conv_vlen(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t nelmts, si
                             /* For nested VL case, free leftover heap objects from the deeper level if the
                              * length of new data elements is shorter than the old data elements.*/
                             if (nested && seq_len < bg_seq_len) {
-                                const uint8_t *tmp;
-                                size_t         u;
+                                uint8_t *tmp;
+                                size_t   u;
 
                                 /* Sanity check */
                                 HDassert(write_to_file);
diff --git a/src/H5Tpkg.h b/src/H5Tpkg.h
index 72afbeb..520b44d 100644
--- a/src/H5Tpkg.h
+++ b/src/H5Tpkg.h
@@ -287,7 +287,7 @@ typedef herr_t (*H5T_vlen_setnull_func_t)(H5VL_object_t *file, void *_vl, void *
 typedef herr_t (*H5T_vlen_read_func_t)(H5VL_object_t *file, void *_vl, void *buf, size_t len);
 typedef herr_t (*H5T_vlen_write_func_t)(H5VL_object_t *file, const H5T_vlen_alloc_info_t *vl_alloc_info,
                                         void *_vl, void *buf, void *_bg, size_t seq_len, size_t base_size);
-typedef herr_t (*H5T_vlen_delete_func_t)(H5VL_object_t *file, const void *_vl);
+typedef herr_t (*H5T_vlen_delete_func_t)(H5VL_object_t *file, void *_vl);
 
 /* VL datatype callbacks */
 typedef struct H5T_vlen_class_t {
diff --git a/src/H5Tref.c b/src/H5Tref.c
index b6b26ce..e8cab02 100644
--- a/src/H5Tref.c
+++ b/src/H5Tref.c
@@ -753,6 +753,14 @@ done:
  *
  *-------------------------------------------------------------------------
  */
+/*
+ * It is the correct thing to do to have the reference buffer
+ * be const-qualified here, but the VOL "blob specific" routine
+ * needs a non-const pointer since an operation might modify
+ * the "blob". Disable this warning here (at least temporarily)
+ * for this reason.
+ */
+H5_GCC_CLANG_DIAG_OFF("cast-qual")
 static herr_t
 H5T__ref_disk_isnull(const H5VL_object_t *src_file, const void *src_buf, hbool_t *isnull)
 {
@@ -792,6 +800,7 @@ H5T__ref_disk_isnull(const H5VL_object_t *src_file, const void *src_buf, hbool_t
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5T__ref_disk_isnull() */
+H5_GCC_CLANG_DIAG_ON("cast-qual")
 
 /*-------------------------------------------------------------------------
  * Function:    H5T__ref_disk_setnull
diff --git a/src/H5Tvlen.c b/src/H5Tvlen.c
index 39d33d4..4823940 100644
--- a/src/H5Tvlen.c
+++ b/src/H5Tvlen.c
@@ -76,7 +76,7 @@ static herr_t H5T__vlen_disk_setnull(H5VL_object_t *file, void *_vl, void *_bg);
 static herr_t H5T__vlen_disk_read(H5VL_object_t *file, void *_vl, void *_buf, size_t len);
 static herr_t H5T__vlen_disk_write(H5VL_object_t *file, const H5T_vlen_alloc_info_t *vl_alloc_info, void *_vl,
                                    void *_buf, void *_bg, size_t seq_len, size_t base_size);
-static herr_t H5T__vlen_disk_delete(H5VL_object_t *file, const void *_vl);
+static herr_t H5T__vlen_disk_delete(H5VL_object_t *file, void *_vl);
 
 /*********************/
 /* Public Variables */
@@ -917,9 +917,9 @@ static herr_t
 H5T__vlen_disk_write(H5VL_object_t *file, const H5T_vlen_alloc_info_t H5_ATTR_UNUSED *vl_alloc_info,
                      void *_vl, void *buf, void *_bg, size_t seq_len, size_t base_size)
 {
-    uint8_t *      vl        = (uint8_t *)_vl;       /* Pointer to the user's hvl_t information */
-    const uint8_t *bg        = (const uint8_t *)_bg; /* Pointer to the old data hvl_t */
-    herr_t         ret_value = SUCCEED;              /* Return value */
+    uint8_t *vl        = (uint8_t *)_vl; /* Pointer to the user's hvl_t information */
+    uint8_t *bg        = (uint8_t *)_bg; /* Pointer to the old data hvl_t */
+    herr_t   ret_value = SUCCEED;        /* Return value */
 
     FUNC_ENTER_PACKAGE
 
@@ -957,10 +957,10 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__vlen_disk_delete(H5VL_object_t *file, const void *_vl)
+H5T__vlen_disk_delete(H5VL_object_t *file, void *_vl)
 {
-    const uint8_t *vl        = (const uint8_t *)_vl; /* Pointer to the user's hvl_t information */
-    herr_t         ret_value = SUCCEED;              /* Return value */
+    uint8_t *vl        = (uint8_t *)_vl; /* Pointer to the user's hvl_t information */
+    herr_t   ret_value = SUCCEED;        /* Return value */
 
     FUNC_ENTER_PACKAGE
 
@@ -981,7 +981,7 @@ H5T__vlen_disk_delete(H5VL_object_t *file, const void *_vl)
             /* Set up VOL callback arguments */
             vol_cb_args.op_type = H5VL_BLOB_DELETE;
 
-            if (H5VL_blob_specific(file, (void *)vl, &vol_cb_args) < 0) /* Casting away 'const' OK -QAK */
+            if (H5VL_blob_specific(file, vl, &vol_cb_args) < 0)
                 HGOTO_ERROR(H5E_DATATYPE, H5E_CANTREMOVE, FAIL, "unable to delete blob")
         } /* end if */
     }     /* end if */