Some stylistic improvements in toast_save_datum()

Move some variables to a smaller scope.  Initialize chunk_data before
storing a pointer to it; this avoids compiler warnings on clang-21, or
respectively us having to work around it by initializing it to zero
before the variable is used (as was done in commit e92677e8633).

Discussion: https://www.postgresql.org/message-id/flat/6604ad6e-5934-43ac-8590-15113d6ae4b1%40eisentraut.org

diff --git a/src/backend/access/common/toast_internals.c b/src/backend/access/common/toast_internals.c
index 75e908c2e80a76313b91807777c8970cd2537a38..81dbd67c72587c6ee2210f0c423fbf7dbcf28b67 100644 (file)
--- a/src/backend/access/common/toast_internals.c
+++ b/src/backend/access/common/toast_internals.c
@@ -121,22 +121,10 @@ toast_save_datum(Relation rel, Datum value,
 {
    Relation    toastrel;
    Relation   *toastidxs;
-   HeapTuple   toasttup;
    TupleDesc   toasttupDesc;
-   Datum       t_values[3];
-   bool        t_isnull[3];
    CommandId   mycid = GetCurrentCommandId(true);
    struct varlena *result;
    struct varatt_external toast_pointer;
-   union
-   {
-       struct varlena hdr;
-       /* this is to make the union big enough for a chunk: */
-       char        data[TOAST_MAX_CHUNK_SIZE + VARHDRSZ];
-       /* ensure union is aligned well enough: */
-       int32       align_it;
-   }           chunk_data = {0};   /* silence compiler warning */
-   int32       chunk_size;
    int32       chunk_seq = 0;
    char       *data_p;
    int32       data_todo;
@@ -289,21 +277,23 @@ toast_save_datum(Relation rel, Datum value,
        }
    }
 
-   /*
-    * Initialize constant parts of the tuple data
-    */
-   t_values[0] = ObjectIdGetDatum(toast_pointer.va_valueid);
-   t_values[2] = PointerGetDatum(&chunk_data);
-   t_isnull[0] = false;
-   t_isnull[1] = false;
-   t_isnull[2] = false;
-
    /*
     * Split up the item into chunks
     */
    while (data_todo > 0)
    {
-       int         i;
+       HeapTuple   toasttup;
+       Datum       t_values[3];
+       bool        t_isnull[3] = {0};
+       union
+       {
+           struct varlena hdr;
+           /* this is to make the union big enough for a chunk: */
+           char        data[TOAST_MAX_CHUNK_SIZE + VARHDRSZ];
+           /* ensure union is aligned well enough: */
+           int32       align_it;
+       }           chunk_data;
+       int32       chunk_size;
 
        CHECK_FOR_INTERRUPTS();
 
@@ -315,9 +305,12 @@ toast_save_datum(Relation rel, Datum value,
        /*
         * Build a tuple and store it
         */
+       t_values[0] = ObjectIdGetDatum(toast_pointer.va_valueid);
        t_values[1] = Int32GetDatum(chunk_seq++);
        SET_VARSIZE(&chunk_data, chunk_size + VARHDRSZ);
        memcpy(VARDATA(&chunk_data), data_p, chunk_size);
+       t_values[2] = PointerGetDatum(&chunk_data);
+
        toasttup = heap_form_tuple(toasttupDesc, t_values, t_isnull);
 
        heap_insert(toastrel, toasttup, mycid, options, NULL);
@@ -333,7 +326,7 @@ toast_save_datum(Relation rel, Datum value,
         * Note also that there had better not be any user-created index on
         * the TOAST table, since we don't bother to update anything else.
         */
-       for (i = 0; i < num_indexes; i++)
+       for (int i = 0; i < num_indexes; i++)
        {
            /* Only index relations marked as ready can be updated */
            if (toastidxs[i]->rd_index->indisready)