Make DatumGetPointer() and PointerGetDatum() macros.

These functions as inline functions were producing warnings, based on discussion
https://groups.google.com/a/greenplum.org/d/msg/gpdb-dev/6fgKvN9QpV4/zjysjqIZAgAJ
converting them to macro as upstream. Adding explicit type casting wherever
needed now that DatumGetPointer() returns (char *) instead of (void *).

src/backend/access/common/memtuple.c

@@ -625,7 +625,7 @@ MemTuple memtuple_form_to(
 				if (old_values == NULL)
 					old_values = (Datum *)palloc0(pbind->tupdesc->natts * sizeof(Datum));
 				old_values[i] = values[i];
-				values[i] = PointerGetDatum(heap_tuple_fetch_attr(DatumGetPointer(values[i])));
+				values[i] = PointerGetDatum(heap_tuple_fetch_attr((struct varlena *)DatumGetPointer(values[i])));
 
 				if (old_values[i] == values[i])
 					old_values[i] = 0;

src/backend/access/common/reloptions.c

@@ -873,7 +873,7 @@ parseRelOptions(Datum options, int numkeywords, const char *const * keywords,
 		return;
 
 	array = DatumGetArrayTypeP(options);
-	isArrayToBeFreed = (array != DatumGetPointer(options));
+	isArrayToBeFreed = (array != (ArrayType *)DatumGetPointer(options));
 
 	Assert(ARR_ELEMTYPE(array) == TEXTOID);
 

src/backend/catalog/aclchk.c

@@ -735,7 +735,7 @@ ExecGrant_Relation(InternalGrant *istmt)
 				char *aclstr = strVal(lfirst(lc));
 				AclItem *newai;
 
-				newai = DatumGetPointer(DirectFunctionCall1(aclitemin,
+				newai = (AclItem *)DatumGetPointer(DirectFunctionCall1(aclitemin,
 											CStringGetDatum(aclstr)));
 
 				aip->ai_grantee = newai->ai_grantee;

src/backend/catalog/pg_compression.c

@@ -179,7 +179,7 @@ callCompressionConstructor(PGFunction constructor,
 						   StorageAttributes *sa,
 						   bool is_compress)
 {
-  return DatumGetPointer(DirectFunctionCall3(constructor,
+	return (CompressionState *) DatumGetPointer(DirectFunctionCall3(constructor,
 											 PointerGetDatum(tupledesc),
 											 PointerGetDatum(sa),
 											 BoolGetDatum(is_compress)));
@@ -226,7 +226,7 @@ zlib_constructor(PG_FUNCTION_ARGS)
 	/* PG_GETARG_POINTER(0) is TupleDesc that is currently unused.
 	 * It is passed as NULL */
 
-	StorageAttributes *sa = PG_GETARG_POINTER(1);
+	StorageAttributes *sa = (StorageAttributes *) PG_GETARG_POINTER(1);
 	CompressionState *cs	   = palloc0(sizeof(CompressionState));
 	zlib_state	   *state	= palloc0(sizeof(zlib_state));
 	bool			  compress = PG_GETARG_BOOL(2);
@@ -251,7 +251,7 @@ zlib_constructor(PG_FUNCTION_ARGS)
 Datum
 zlib_destructor(PG_FUNCTION_ARGS)
 {
-	CompressionState *cs = PG_GETARG_POINTER(0);
+	CompressionState *cs = (CompressionState *) PG_GETARG_POINTER(0);
 
 	if (cs != NULL && cs->opaque != NULL)
  	{
@@ -268,7 +268,7 @@ zlib_compress(PG_FUNCTION_ARGS)
 	int32			 src_sz   = PG_GETARG_INT32(1);
 	void			 *dst	  = PG_GETARG_POINTER(2);
 	int32			 dst_sz   = PG_GETARG_INT32(3);
-	int32			*dst_used = PG_GETARG_POINTER(4);
+	int32			*dst_used = (int32 *) PG_GETARG_POINTER(4);
 	CompressionState *cs	   = (CompressionState *) PG_GETARG_POINTER(5);
 	zlib_state	   *state	= (zlib_state *) cs->opaque;
 	int				last_error;
@@ -317,7 +317,7 @@ zlib_decompress(PG_FUNCTION_ARGS)
 	int32			src_sz = PG_GETARG_INT32(1);
 	void		   *dst	= PG_GETARG_POINTER(2);
 	int32			dst_sz = PG_GETARG_INT32(3);
-	int32		   *dst_used = PG_GETARG_POINTER(4);
+	int32		   *dst_used = (int32 *) PG_GETARG_POINTER(4);
 	CompressionState *cs = (CompressionState *) PG_GETARG_POINTER(5);
 	zlib_state	   *state = (zlib_state *) cs->opaque;
 	int				last_error;

src/backend/cdb/cdbhash.c

@@ -311,7 +311,7 @@ hashDatum(Datum datum, Oid type, datumHashFunction hashFn, void *clientData)
              * If we did a pg_detoast_datum, we need to remember to pfree, 
              * or we will leak memory.  Because of the 1-byte varlena header stuff.
              */
-            if (num != DatumGetPointer(datum)) 
+            if (num != (Numeric) DatumGetPointer(datum)) 
                 tofree = num;
 
 			break;

src/backend/cdb/cdbpartition.c

@@ -2156,11 +2156,11 @@ partMakePartition(HeapTuple tuple)
 	p->paristemplate = partrow->paristemplate;
 	p->parnatts = partrow->parnatts;
 
-	atts = DatumGetPointer(SysCacheGetAttr(PARTOID, tuple,
+	atts = (int2vector *) DatumGetPointer(SysCacheGetAttr(PARTOID, tuple,
 										   Anum_pg_partition_paratts,
 										   &isnull));
 	Assert(!isnull);
-	oids = DatumGetPointer(SysCacheGetAttr(PARTOID, tuple,
+	oids = (oidvector *) DatumGetPointer(SysCacheGetAttr(PARTOID, tuple,
 										   Anum_pg_partition_parclass,
 										   &isnull));
 	Assert(!isnull);
@@ -2373,8 +2373,9 @@ get_partition_key_bitmapset(Oid relid)
 			continue;  /* no interest in template parts */
 
 		natts = partrow->parnatts;
-		atts = DatumGetPointer(heap_getattr(tuple, Anum_pg_partition_paratts,
-											tupledesc, &isnull));
+		atts = (int2vector *) DatumGetPointer(
+			heap_getattr(tuple, Anum_pg_partition_paratts,
+						 tupledesc, &isnull));
 		Insist(!isnull);
 
 		for ( i = 0; i < natts; i++ )

src/backend/cdb/cdbresynchronizechangetracking.c

@@ -1428,7 +1428,8 @@ ChangeTracking_GetIncrementalChangeList(void)
 					result = ChangeTracking_InitIncrementalChangeList(proc);
 				
 				/* convert to desired data type */
-				persistentTid = DatumGetPointer(DirectFunctionCall1(tidin, CStringGetDatum(str_tid)));
+				persistentTid = (ItemPointer) DatumGetPointer(
+					DirectFunctionCall1(tidin, CStringGetDatum(str_tid)));
 				persistentSerialNum = DatumGetInt64(DirectFunctionCall1(int8in, CStringGetDatum(str_sn)));
 				numblocks = DatumGetInt64(DirectFunctionCall1(int8in, CStringGetDatum(str_numb)));
 				
@@ -3178,7 +3179,8 @@ int ChangeTracking_CompactLogFile(CTFType source, CTFType dest, XLogRecPtr*	upto
 				relfile.relNode = DatumGetObjectId(DirectFunctionCall1(oidin, CStringGetDatum(str_rel)));
 				blocknum = DatumGetUInt32(DirectFunctionCall1(int4in, CStringGetDatum(str_blocknum)));
 				endlsn = (XLogRecPtr*) DatumGetPointer(DirectFunctionCall1(gpxloglocin, CStringGetDatum(str_endlsn)));
-				persistentTid = DatumGetPointer(DirectFunctionCall1(tidin, CStringGetDatum(str_tid)));
+				persistentTid = (ItemPointer) DatumGetPointer(
+					DirectFunctionCall1(tidin, CStringGetDatum(str_tid)));
 				persistentSerialNum = DatumGetInt64(DirectFunctionCall1(int8in, CStringGetDatum(str_sn)));
 
 				SIMPLE_FAULT_INJECTOR(FileRepChangeTrackingCompacting);

src/backend/executor/tstoreReceiver.c

@@ -141,7 +141,7 @@ tstoreReceiveSlot_detoast(TupleTableSlot *slot, DestReceiver *self)
 			if (VARATT_IS_EXTERNAL(DatumGetPointer(val)))
 			{
 				val = PointerGetDatum(heap_tuple_fetch_attr(
-														DatumGetPointer(val)));
+										  (struct varlena *) DatumGetPointer(val)));
 				myState->tofree[nfree++] = val;
 			}
 		}

src/backend/nodes/copyfuncs.c

@@ -74,7 +74,7 @@
 	do { \
 		if (from->fldname) \
 		{ \
-			newnode->fldname = DatumGetPointer( \
+			newnode->fldname = (bytea *) DatumGetPointer( \
 					datumCopy(PointerGetDatum(from->fldname), false, len)); \
 		} \
 	} while (0)

src/backend/nodes/readfast.c

@@ -127,7 +127,7 @@
 
 /* Read a bytea field */
 #define READ_BYTEA_FIELD(fldname) \
-	local_node->fldname = DatumGetPointer(readDatum(false))
+	local_node->fldname = (bytea *) DatumGetPointer(readDatum(false))
 
 /* Read a dummy field */
 #define READ_DUMMY_FIELD(fldname,fldvalue) \

src/backend/nodes/readfuncs.c

@@ -155,7 +155,7 @@ inline static char extended_char(char* token, size_t length)
 
 /* Read a bytea field */
 #define READ_BYTEA_FIELD(fldname) \
-	local_node->fldname = DatumGetPointer(readDatum(false))
+	local_node->fldname = (bytea *) DatumGetPointer(readDatum(false))
 
 /* Set field to a given value, ignoring the value read from the input */
 #define READ_DUMMY_FIELD(fldname,fldvalue)  READ_SCALAR_FIELD(fldname, fldvalue)

src/backend/utils/datumstream/datumstream.c

@@ -1090,7 +1090,8 @@ datumstreamwrite_lob(DatumStreamWrite * acc,
 	 */
 	if (VARATT_IS_EXTERNAL(DatumGetPointer(d)))
 	{
-		d = PointerGetDatum(heap_tuple_fetch_attr(DatumGetPointer(d)));
+		d = PointerGetDatum(heap_tuple_fetch_attr(
+								(struct varlena *) DatumGetPointer(d)));
 	}
 
 	p = (uint8 *) DatumGetPointer(d);

src/backend/utils/datumstream/datumstreamblock.c

@@ -1162,7 +1162,7 @@ DatumStreamBlockWrite_PrintInputVarlenaInfo(
 {
 	uint8	   *p;
 
-	p = DatumGetPointer(originalDatum);
+	p = (uint8 *) DatumGetPointer(originalDatum);
 
 	ereport(LOG,
 		  (errmsg("Write input varlena input <%s> (nth %d, was extended %s)",

src/backend/utils/sort/tuplesort.c

@@ -978,7 +978,7 @@ tuplesort_putdatum(Tuplesortstate *state, Datum val, bool isNull)
 	{
 		stup.datum1 = datumCopy(val, false, state->datumTypeLen);
 		stup.isnull1 = false;
-		stup.tuple = DatumGetPointer(stup.datum1);
+		stup.tuple = (MemTuple) DatumGetPointer(stup.datum1);
 		USEMEM(state, GetMemoryChunkSpace(DatumGetPointer(stup.datum1))); 
 	}
 

src/include/postgres.h

@@ -359,8 +359,19 @@ static inline Datum TransactionIdGetDatum(TransactionId tid) { return (Datum) ti
 static inline CommandId DatumGetCommandId(Datum d) { return (CommandId) d; } 
 static inline Datum CommandIdGetDatum(CommandId cid) { return (Datum) cid; } 
 
-static inline void *DatumGetPointer(Datum d) { Datum_U du; du.d = d; return du.ptr; }
-static inline Datum PointerGetDatum(const void *p) { Datum_U du; du.d = 0; du.ptr = (void *)p; return du.d; }
+/*
+ * DatumGetPointer
+ *		Returns pointer value of a datum.
+ */
+
+#define DatumGetPointer(X) ((Pointer) (X))
+
+/*
+ * PointerGetDatum
+ *		Returns datum representation for a pointer.
+ */
+
+#define PointerGetDatum(X) ((Datum) (X))
 
 static inline char *DatumGetCString(Datum d) { return (char* ) DatumGetPointer(d); } 
 static inline Datum CStringGetDatum(const char *p) { return PointerGetDatum(p); }