Use more palloc_object() and palloc_array() in contrib/

The idea is to encourage more the use of these new routines across the
tree, as these offer stronger type safety guarantees than palloc().  In
an ideal world, palloc() would then act as an internal routine of these
flavors, whose footprint in the tree is minimal.

The patch sent by the author is very large, and this chunk of changes
represents something like 10% of the overall patch submitted.

The code compiled is the same before and after this commit, using
objdump to do some validation with a difference taken in-between.  There
are some diffs, which are caused by changes in line numbers because some
of the new allocation formulas are shorter, for the following files:
trgm_regexp.c, xpath.c and pg_walinspect.c.

Author: David Geier <geidav.pg@gmail.com>
Discussion: https://postgr.es/m/ad0748d4-3080-436e-b0bc-ac8f86a3466a@gmail.com

Author: michaelpq

contrib/amcheck/verify_gin.c

@@ -117,7 +117,7 @@ ginReadTupleWithoutState(IndexTuple itup, int *nitems)
 	}
 	else
 	{
-		ipd = (ItemPointer) palloc(sizeof(ItemPointerData) * nipd);
+		ipd = palloc_array(ItemPointerData, nipd);
 		memcpy(ipd, ptr, sizeof(ItemPointerData) * nipd);
 	}
 	*nitems = nipd;
@@ -152,7 +152,7 @@ gin_check_posting_tree_parent_keys_consistency(Relation rel, BlockNumber posting
 	leafdepth = -1;
 
 	/* Start the scan at the root page */
-	stack = (GinPostingTreeScanItem *) palloc0(sizeof(GinPostingTreeScanItem));
+	stack = palloc0_object(GinPostingTreeScanItem);
 	stack->depth = 0;
 	ItemPointerSetInvalid(&stack->parentkey);
 	stack->parentblk = InvalidBlockNumber;
@@ -354,7 +354,7 @@ gin_check_posting_tree_parent_keys_consistency(Relation rel, BlockNumber posting
 									stack->blkno, i)));
 
 				/* This is an internal page, recurse into the child. */
-				ptr = (GinPostingTreeScanItem *) palloc(sizeof(GinPostingTreeScanItem));
+				ptr = palloc_object(GinPostingTreeScanItem);
 				ptr->depth = stack->depth + 1;
 
 				/*
@@ -412,7 +412,7 @@ gin_check_parent_keys_consistency(Relation rel,
 	leafdepth = -1;
 
 	/* Start the scan at the root page */
-	stack = (GinScanItem *) palloc0(sizeof(GinScanItem));
+	stack = palloc0_object(GinScanItem);
 	stack->depth = 0;
 	stack->parenttup = NULL;
 	stack->parentblk = InvalidBlockNumber;
@@ -473,7 +473,7 @@ gin_check_parent_keys_consistency(Relation rel,
 
 				elog(DEBUG3, "split detected for blk: %u, parent blk: %u", stack->blkno, stack->parentblk);
 
-				ptr = (GinScanItem *) palloc(sizeof(GinScanItem));
+				ptr = palloc_object(GinScanItem);
 				ptr->depth = stack->depth;
 				ptr->parenttup = CopyIndexTuple(stack->parenttup);
 				ptr->parentblk = stack->parentblk;
@@ -601,7 +601,7 @@ gin_check_parent_keys_consistency(Relation rel,
 			{
 				GinScanItem *ptr;
 
-				ptr = (GinScanItem *) palloc(sizeof(GinScanItem));
+				ptr = palloc_object(GinScanItem);
 				ptr->depth = stack->depth + 1;
 				/* last tuple in layer has no high key */
 				if (i == maxoff && rightlink == InvalidBlockNumber)

contrib/amcheck/verify_heapam.c

@@ -1838,7 +1838,7 @@ check_tuple_attribute(HeapCheckContext *ctx)
 	{
 		ToastedAttribute *ta;
 
-		ta = (ToastedAttribute *) palloc0(sizeof(ToastedAttribute));
+		ta = palloc0_object(ToastedAttribute);
 
 		VARATT_EXTERNAL_GET_POINTER(ta->toast_pointer, attr);
 		ta->blkno = ctx->blkno;

contrib/amcheck/verify_nbtree.c

@@ -399,7 +399,7 @@ bt_check_every_level(Relation rel, Relation heaprel, bool heapkeyspace,
 	/*
 	 * Initialize state for entire verification operation
 	 */
-	state = palloc0(sizeof(BtreeCheckState));
+	state = palloc0_object(BtreeCheckState);
 	state->rel = rel;
 	state->heaprel = heaprel;
 	state->heapkeyspace = heapkeyspace;

contrib/basebackup_to_shell/basebackup_to_shell.c

@@ -136,7 +136,7 @@ shell_get_sink(bbsink *next_sink, void *detail_arg)
 	 * We remember the current value of basebackup_to_shell.shell_command to
 	 * be certain that it can't change under us during the backup.
 	 */
-	sink = palloc0(sizeof(bbsink_shell));
+	sink = palloc0_object(bbsink_shell);
 	*((const bbsink_ops **) &sink->base.bbs_ops) = &bbsink_shell_ops;
 	sink->base.bbs_next = next_sink;
 	sink->target_detail = detail_arg;

contrib/bloom/blinsert.c

@@ -151,7 +151,7 @@ blbuild(Relation heap, Relation index, IndexInfo *indexInfo)
 
 	MemoryContextDelete(buildstate.tmpCtx);
 
-	result = (IndexBuildResult *) palloc(sizeof(IndexBuildResult));
+	result = palloc_object(IndexBuildResult);
 	result->heap_tuples = reltuples;
 	result->index_tuples = buildstate.indtuples;
 

contrib/bloom/blscan.c

@@ -29,7 +29,7 @@ blbeginscan(Relation r, int nkeys, int norderbys)
 
 	scan = RelationGetIndexScan(r, nkeys, norderbys);
 
-	so = (BloomScanOpaque) palloc(sizeof(BloomScanOpaqueData));
+	so = (BloomScanOpaque) palloc_object(BloomScanOpaqueData);
 	initBloomState(&so->state, scan->indexRelation);
 	so->sign = NULL;
 
@@ -86,7 +86,7 @@ blgetbitmap(IndexScanDesc scan, TIDBitmap *tbm)
 		/* New search: have to calculate search signature */
 		ScanKey		skey = scan->keyData;
 
-		so->sign = palloc0(sizeof(BloomSignatureWord) * so->state.opts.bloomLength);
+		so->sign = palloc0_array(BloomSignatureWord, so->state.opts.bloomLength);
 
 		for (i = 0; i < scan->numberOfKeys; i++)
 		{

contrib/bloom/blutils.c

@@ -86,7 +86,7 @@ makeDefaultBloomOptions(void)
 	BloomOptions *opts;
 	int			i;
 
-	opts = (BloomOptions *) palloc0(sizeof(BloomOptions));
+	opts = palloc0_object(BloomOptions);
 	/* Convert DEFAULT_BLOOM_LENGTH from # of bits to # of words */
 	opts->bloomLength = (DEFAULT_BLOOM_LENGTH + SIGNWORDBITS - 1) / SIGNWORDBITS;
 	for (i = 0; i < INDEX_MAX_KEYS; i++)

contrib/bloom/blvacuum.c

@@ -42,7 +42,7 @@ blbulkdelete(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
 	GenericXLogState *gxlogState;
 
 	if (stats == NULL)
-		stats = (IndexBulkDeleteResult *) palloc0(sizeof(IndexBulkDeleteResult));
+		stats = palloc0_object(IndexBulkDeleteResult);
 
 	initBloomState(&state, index);
 
@@ -171,7 +171,7 @@ blvacuumcleanup(IndexVacuumInfo *info, IndexBulkDeleteResult *stats)
 		return stats;
 
 	if (stats == NULL)
-		stats = (IndexBulkDeleteResult *) palloc0(sizeof(IndexBulkDeleteResult));
+		stats = palloc0_object(IndexBulkDeleteResult);
 
 	/*
 	 * Iterate over the pages: insert deleted pages into FSM and collect

contrib/btree_gin/btree_gin.c

@@ -52,7 +52,7 @@ gin_btree_extract_value(FunctionCallInfo fcinfo, bool is_varlena)
 {
 	Datum		datum = PG_GETARG_DATUM(0);
 	int32	   *nentries = (int32 *) PG_GETARG_POINTER(1);
-	Datum	   *entries = (Datum *) palloc(sizeof(Datum));
+	Datum	   *entries = palloc_object(Datum);
 
 	/* Ensure that values stored in the index are not toasted */
 	if (is_varlena)
@@ -75,9 +75,9 @@ gin_btree_extract_query(FunctionCallInfo fcinfo,
 	StrategyNumber strategy = PG_GETARG_UINT16(2);
 	bool	  **partialmatch = (bool **) PG_GETARG_POINTER(3);
 	Pointer   **extra_data = (Pointer **) PG_GETARG_POINTER(4);
-	Datum	   *entries = (Datum *) palloc(sizeof(Datum));
-	QueryInfo  *data = (QueryInfo *) palloc(sizeof(QueryInfo));
-	bool	   *ptr_partialmatch = (bool *) palloc(sizeof(bool));
+	Datum	   *entries = palloc_object(Datum);
+	QueryInfo  *data = palloc_object(QueryInfo);
+	bool	   *ptr_partialmatch = palloc_object(bool);
 	int			btree_strat,
 				rhs_code;
 
@@ -140,7 +140,7 @@ gin_btree_extract_query(FunctionCallInfo fcinfo,
 	data->orig_datum = datum;
 	data->entry_datum = entries[0];
 	data->typecmp = cmp_fns[rhs_code];
-	*extra_data = (Pointer *) palloc(sizeof(Pointer));
+	*extra_data = palloc_object(Pointer);
 	**extra_data = (Pointer) data;
 
 	PG_RETURN_POINTER(entries);
@@ -579,7 +579,7 @@ GIN_SUPPORT(time, leftmostvalue_time, time_rhs_is_varlena, NULL, time_cmp_fns)
 static Datum
 leftmostvalue_timetz(void)
 {
-	TimeTzADT  *v = palloc(sizeof(TimeTzADT));
+	TimeTzADT  *v = palloc_object(TimeTzADT);
 
 	v->time = 0;
 	v->zone = -24 * 3600;		/* XXX is that true? */
@@ -639,7 +639,7 @@ GIN_SUPPORT(date, leftmostvalue_date, date_rhs_is_varlena, date_cvt_fns, date_cm
 static Datum
 leftmostvalue_interval(void)
 {
-	Interval   *v = palloc(sizeof(Interval));
+	Interval   *v = palloc_object(Interval);
 
 	INTERVAL_NOBEGIN(v);
 
@@ -657,7 +657,7 @@ GIN_SUPPORT(interval, leftmostvalue_interval, interval_rhs_is_varlena, NULL, int
 static Datum
 leftmostvalue_macaddr(void)
 {
-	macaddr    *v = palloc0(sizeof(macaddr));
+	macaddr    *v = palloc0_object(macaddr);
 
 	return MacaddrPGetDatum(v);
 }
@@ -673,7 +673,7 @@ GIN_SUPPORT(macaddr, leftmostvalue_macaddr, macaddr_rhs_is_varlena, NULL, macadd
 static Datum
 leftmostvalue_macaddr8(void)
 {
-	macaddr8   *v = palloc0(sizeof(macaddr8));
+	macaddr8   *v = palloc0_object(macaddr8);
 
 	return Macaddr8PGetDatum(v);
 }
@@ -910,7 +910,7 @@ leftmostvalue_uuid(void)
 	 * palloc0 will create the UUID with all zeroes:
 	 * "00000000-0000-0000-0000-000000000000"
 	 */
-	pg_uuid_t  *retval = (pg_uuid_t *) palloc0(sizeof(pg_uuid_t));
+	pg_uuid_t  *retval = palloc0_object(pg_uuid_t);
 
 	return UUIDPGetDatum(retval);
 }

contrib/btree_gist/btree_inet.c

@@ -97,10 +97,10 @@ gbt_inet_compress(PG_FUNCTION_ARGS)
 
 	if (entry->leafkey)
 	{
-		inetKEY    *r = (inetKEY *) palloc(sizeof(inetKEY));
+		inetKEY    *r = palloc_object(inetKEY);
 		bool		failure = false;
 
-		retval = palloc(sizeof(GISTENTRY));
+		retval = palloc_object(GISTENTRY);
 		r->lower = convert_network_to_scalar(entry->key, INETOID, &failure);
 		Assert(!failure);
 		r->upper = r->lower;