Remove unnecessary (char *) casts [mem]

Remove (char *) casts around memory functions such as memcmp(),
memcpy(), or memset() where the cast is useless.  Since these
functions don't take char * arguments anyway, these casts are at best
complicated casts to (void *), about which see commit 7f798aca1d.

Reviewed-by: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
Discussion: https://www.postgresql.org/message-id/flat/fd1fcedb-3492-4fc8-9e3e-74b97f2db6c7%40eisentraut.org

src/backend/access/common/heaptuple.c

@@ -787,7 +787,7 @@ heap_copytuple(HeapTuple tuple)
 	newTuple->t_self = tuple->t_self;
 	newTuple->t_tableOid = tuple->t_tableOid;
 	newTuple->t_data = (HeapTupleHeader) ((char *) newTuple + HEAPTUPLESIZE);
-	memcpy((char *) newTuple->t_data, (char *) tuple->t_data, tuple->t_len);
+	memcpy(newTuple->t_data, tuple->t_data, tuple->t_len);
 	return newTuple;
 }
 
@@ -813,7 +813,7 @@ heap_copytuple_with_tuple(HeapTuple src, HeapTuple dest)
 	dest->t_self = src->t_self;
 	dest->t_tableOid = src->t_tableOid;
 	dest->t_data = (HeapTupleHeader) palloc(src->t_len);
-	memcpy((char *) dest->t_data, (char *) src->t_data, src->t_len);
+	memcpy(dest->t_data, src->t_data, src->t_len);
 }
 
 /*
@@ -1097,7 +1097,7 @@ heap_copy_tuple_as_datum(HeapTuple tuple, TupleDesc tupleDesc)
 	 * the given tuple came from disk, rather than from heap_form_tuple).
 	 */
 	td = (HeapTupleHeader) palloc(tuple->t_len);
-	memcpy((char *) td, (char *) tuple->t_data, tuple->t_len);
+	memcpy(td, tuple->t_data, tuple->t_len);
 
 	HeapTupleHeaderSetDatumLength(td, tuple->t_len);
 	HeapTupleHeaderSetTypeId(td, tupleDesc->tdtypeid);

src/backend/access/heap/heapam_xlog.c

@@ -480,11 +480,11 @@ heap_xlog_insert(XLogReaderState *record)
 
 		newlen = datalen - SizeOfHeapHeader;
 		Assert(datalen > SizeOfHeapHeader && newlen <= MaxHeapTupleSize);
-		memcpy((char *) &xlhdr, data, SizeOfHeapHeader);
+		memcpy(&xlhdr, data, SizeOfHeapHeader);
 		data += SizeOfHeapHeader;
 
 		htup = &tbuf.hdr;
-		MemSet((char *) htup, 0, SizeofHeapTupleHeader);
+		MemSet(htup, 0, SizeofHeapTupleHeader);
 		/* PG73FORMAT: get bitmap [+ padding] [+ oid] + data */
 		memcpy((char *) htup + SizeofHeapTupleHeader,
 			   data,
@@ -625,10 +625,10 @@ heap_xlog_multi_insert(XLogReaderState *record)
 			newlen = xlhdr->datalen;
 			Assert(newlen <= MaxHeapTupleSize);
 			htup = &tbuf.hdr;
-			MemSet((char *) htup, 0, SizeofHeapTupleHeader);
+			MemSet(htup, 0, SizeofHeapTupleHeader);
 			/* PG73FORMAT: get bitmap [+ padding] [+ oid] + data */
 			memcpy((char *) htup + SizeofHeapTupleHeader,
-				   (char *) tupdata,
+				   tupdata,
 				   newlen);
 			tupdata += newlen;
 
@@ -854,14 +854,14 @@ heap_xlog_update(XLogReaderState *record, bool hot_update)
 			recdata += sizeof(uint16);
 		}
 
-		memcpy((char *) &xlhdr, recdata, SizeOfHeapHeader);
+		memcpy(&xlhdr, recdata, SizeOfHeapHeader);
 		recdata += SizeOfHeapHeader;
 
 		tuplen = recdata_end - recdata;
 		Assert(tuplen <= MaxHeapTupleSize);
 
 		htup = &tbuf.hdr;
-		MemSet((char *) htup, 0, SizeofHeapTupleHeader);
+		MemSet(htup, 0, SizeofHeapTupleHeader);
 
 		/*
 		 * Reconstruct the new tuple using the prefix and/or suffix from the

src/backend/access/table/toast_helper.c

@@ -75,7 +75,7 @@ toast_tuple_init(ToastTupleContext *ttc)
 			{
 				if (ttc->ttc_isnull[i] ||
 					!VARATT_IS_EXTERNAL_ONDISK(new_value) ||
-					memcmp((char *) old_value, (char *) new_value,
+					memcmp(old_value, new_value,
 						   VARSIZE_EXTERNAL(old_value)) != 0)
 				{
 					/*

src/backend/access/transam/xlog.c

@@ -2089,7 +2089,7 @@ AdvanceXLInsertBuffer(XLogRecPtr upto, TimeLineID tli, bool opportunistic)
 		 * Be sure to re-zero the buffer so that bytes beyond what we've
 		 * written will look like zeroes and not valid XLOG records...
 		 */
-		MemSet((char *) NewPage, 0, XLOG_BLCKSZ);
+		MemSet(NewPage, 0, XLOG_BLCKSZ);
 
 		/*
 		 * Fill the new page's header

src/backend/access/transam/xlogreader.c

@@ -794,7 +794,7 @@ restart:
 				readOff = ReadPageInternal(state, targetPagePtr,
 										   pageHeaderSize + len);
 
-			memcpy(buffer, (char *) contdata, len);
+			memcpy(buffer, contdata, len);
 			buffer += len;
 			gotlen += len;