Fix unportable assumptions about alignment of local char[n] variables.

Author: tglsfdc

src/backend/access/heap/heapam.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.112 2001/03/22 06:16:07 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.113 2001/03/25 23:23:58 tgl Exp $
  *
  *
  * INTERFACE ROUTINES
@@ -2126,10 +2126,19 @@ static XLogRecPtr
 log_heap_update(Relation reln, Buffer oldbuf, ItemPointerData from,
 				Buffer newbuf, HeapTuple newtup, bool move)
 {
-	char		tbuf[MAXALIGN(sizeof(xl_heap_header)) + 2 * sizeof(TransactionId)];
-	xl_heap_update xlrec;
-	xl_heap_header *xlhdr = (xl_heap_header *) tbuf;
+	/*
+	 * Note: xlhdr is declared to have adequate size and correct alignment
+	 * for an xl_heap_header.  However the two tids, if present at all,
+	 * will be packed in with no wasted space after the xl_heap_header;
+	 * they aren't necessarily aligned as implied by this struct declaration.
+	 */
+	struct {
+		xl_heap_header	hdr;
+		TransactionId	tid1;
+		TransactionId	tid2;
+	}			xlhdr;
 	int			hsize = SizeOfHeapHeader;
+	xl_heap_update xlrec;
 	XLogRecPtr	recptr;
 	XLogRecData rdata[4];
 	Page		page = BufferGetPage(newbuf);
@@ -2148,10 +2157,10 @@ log_heap_update(Relation reln, Buffer oldbuf, ItemPointerData from,
 	rdata[1].len = 0;
 	rdata[1].next = &(rdata[2]);
 
-	xlhdr->t_oid = newtup->t_data->t_oid;
-	xlhdr->t_natts = newtup->t_data->t_natts;
-	xlhdr->t_hoff = newtup->t_data->t_hoff;
-	xlhdr->mask = newtup->t_data->t_infomask;
+	xlhdr.hdr.t_oid = newtup->t_data->t_oid;
+	xlhdr.hdr.t_natts = newtup->t_data->t_natts;
+	xlhdr.hdr.t_hoff = newtup->t_data->t_hoff;
+	xlhdr.hdr.mask = newtup->t_data->t_infomask;
 	if (move)					/* remember xmin & xmax */
 	{
 		TransactionId xmax;
@@ -2161,13 +2170,13 @@ log_heap_update(Relation reln, Buffer oldbuf, ItemPointerData from,
 			xmax = InvalidTransactionId;
 		else
 			xmax = newtup->t_data->t_xmax;
-		memcpy(tbuf + hsize, &xmax, sizeof(TransactionId));
-		memcpy(tbuf + hsize + sizeof(TransactionId),
+		memcpy((char *) &xlhdr + hsize, &xmax, sizeof(TransactionId));
+		memcpy((char *) &xlhdr + hsize + sizeof(TransactionId),
 			   &(newtup->t_data->t_xmin), sizeof(TransactionId));
-		hsize += (2 * sizeof(TransactionId));
+		hsize += 2 * sizeof(TransactionId);
 	}
 	rdata[2].buffer = newbuf;
-	rdata[2].data = (char *) xlhdr;
+	rdata[2].data = (char *) &xlhdr;
 	rdata[2].len = hsize;
 	rdata[2].next = &(rdata[3]);
 
@@ -2228,13 +2237,16 @@ heap_xlog_clean(bool redo, XLogRecPtr lsn, XLogRecord *record)
 
 	if (record->xl_len > SizeOfHeapClean)
 	{
-		char		unbuf[BLCKSZ];
-		OffsetNumber *unused = (OffsetNumber *) unbuf;
+		OffsetNumber unbuf[BLCKSZ/sizeof(OffsetNumber)];
+		OffsetNumber *unused = unbuf;
 		char	   *unend;
 		ItemId		lp;
 
-		memcpy(unbuf, (char *) xlrec + SizeOfHeapClean, record->xl_len - SizeOfHeapClean);
-		unend = unbuf + (record->xl_len - SizeOfHeapClean);
+		Assert((record->xl_len - SizeOfHeapClean) <= BLCKSZ);
+		memcpy((char *) unbuf,
+			   (char *) xlrec + SizeOfHeapClean,
+			   record->xl_len - SizeOfHeapClean);
+		unend = (char *) unbuf + (record->xl_len - SizeOfHeapClean);
 
 		while ((char *) unused < unend)
 		{
@@ -2318,7 +2330,6 @@ heap_xlog_insert(bool redo, XLogRecPtr lsn, XLogRecord *record)
 	Buffer		buffer;
 	Page		page;
 	OffsetNumber offnum;
-	HeapTupleHeader htup;
 
 	if (redo && (record->xl_info & XLR_BKP_BLOCK_1))
 		return;
@@ -2338,7 +2349,11 @@ heap_xlog_insert(bool redo, XLogRecPtr lsn, XLogRecord *record)
 
 	if (redo)
 	{
-		char		tbuf[MaxTupleSize];
+		struct {
+			HeapTupleHeaderData hdr;
+			char				data[MaxTupleSize];
+		}			tbuf;
+		HeapTupleHeader htup;
 		xl_heap_header xlhdr;
 		uint32		newlen;
 
@@ -2359,11 +2374,15 @@ heap_xlog_insert(bool redo, XLogRecPtr lsn, XLogRecord *record)
 			elog(STOP, "heap_insert_redo: invalid max offset number");
 
 		newlen = record->xl_len - SizeOfHeapInsert - SizeOfHeapHeader;
-		memcpy((char *) &xlhdr, (char *) xlrec + SizeOfHeapInsert, SizeOfHeapHeader);
-		memcpy(tbuf + offsetof(HeapTupleHeaderData, t_bits),
-		   (char *) xlrec + SizeOfHeapInsert + SizeOfHeapHeader, newlen);
+		Assert(newlen <= MaxTupleSize);
+		memcpy((char *) &xlhdr,
+			   (char *) xlrec + SizeOfHeapInsert,
+			   SizeOfHeapHeader);
+		memcpy((char *) &tbuf + offsetof(HeapTupleHeaderData, t_bits),
+			   (char *) xlrec + SizeOfHeapInsert + SizeOfHeapHeader,
+			   newlen);
 		newlen += offsetof(HeapTupleHeaderData, t_bits);
-		htup = (HeapTupleHeader) tbuf;
+		htup = &tbuf.hdr;
 		htup->t_oid = xlhdr.t_oid;
 		htup->t_natts = xlhdr.t_natts;
 		htup->t_hoff = xlhdr.t_hoff;
@@ -2496,7 +2515,10 @@ newsame:;
 
 	if (redo)
 	{
-		char		tbuf[MaxTupleSize];
+		struct {
+			HeapTupleHeaderData hdr;
+			char				data[MaxTupleSize];
+		}			tbuf;
 		xl_heap_header xlhdr;
 		int			hsize;
 		uint32		newlen;
@@ -2522,20 +2544,27 @@ newsame:;
 			hsize += (2 * sizeof(TransactionId));
 
 		newlen = record->xl_len - hsize;
-		memcpy((char *) &xlhdr, (char *) xlrec + SizeOfHeapUpdate, SizeOfHeapHeader);
-		memcpy(tbuf + offsetof(HeapTupleHeaderData, t_bits),
-			   (char *) xlrec + hsize, newlen);
+		Assert(newlen <= MaxTupleSize);
+		memcpy((char *) &xlhdr,
+			   (char *) xlrec + SizeOfHeapUpdate,
+			   SizeOfHeapHeader);
+		memcpy((char *) &tbuf + offsetof(HeapTupleHeaderData, t_bits),
+			   (char *) xlrec + hsize,
+			   newlen);
 		newlen += offsetof(HeapTupleHeaderData, t_bits);
-		htup = (HeapTupleHeader) tbuf;
+		htup = &tbuf.hdr;
 		htup->t_oid = xlhdr.t_oid;
 		htup->t_natts = xlhdr.t_natts;
 		htup->t_hoff = xlhdr.t_hoff;
 		if (move)
 		{
 			hsize = SizeOfHeapUpdate + SizeOfHeapHeader;
-			memcpy(&(htup->t_xmax), (char *) xlrec + hsize, sizeof(TransactionId));
+			memcpy(&(htup->t_xmax),
+				   (char *) xlrec + hsize,
+				   sizeof(TransactionId));
 			memcpy(&(htup->t_xmin),
-				   (char *) xlrec + hsize + sizeof(TransactionId), sizeof(TransactionId));
+				   (char *) xlrec + hsize + sizeof(TransactionId),
+				   sizeof(TransactionId));
 			TransactionIdStore(record->xl_xid, (TransactionId *) &(htup->t_cmin));
 			htup->t_infomask = xlhdr.mask;
 			htup->t_infomask &= ~(HEAP_XMIN_COMMITTED |

src/backend/commands/vacuum.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.188 2001/03/22 03:59:24 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.189 2001/03/25 23:23:58 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -303,10 +303,9 @@ getrels(NameData *VacRelP)
 		found = true;
 
 		d = heap_getattr(tuple, Anum_pg_class_relname, tupdesc, &n);
-		rname = (char *) d;
+		rname = (char *) DatumGetPointer(d);
 
 		d = heap_getattr(tuple, Anum_pg_class_relkind, tupdesc, &n);
-
 		rkind = DatumGetChar(d);
 
 		if (rkind != RELKIND_RELATION)
@@ -997,8 +996,8 @@ repair_frag(VRelStats *vacrelstats, Relation onerel,
 				blkno;
 	Page		page,
 				ToPage = NULL;
-	OffsetNumber offnum = 0,
-				maxoff = 0,
+	OffsetNumber offnum,
+				maxoff,
 				newoff,
 				max_offset;
 	ItemId		itemid,
@@ -1913,14 +1912,15 @@ failed to add item with len = %lu to page %u (free space %lu, nusd %u, noff %u)"
 		if (vacpage->blkno == (BlockNumber) (blkno - 1) &&
 			vacpage->offsets_free > 0)
 		{
-			char		unbuf[BLCKSZ];
-			OffsetNumber *unused = (OffsetNumber *) unbuf;
+			OffsetNumber unbuf[BLCKSZ/sizeof(OffsetNumber)];
+			OffsetNumber *unused = unbuf;
 			int			uncnt;
 
 			buf = ReadBuffer(onerel, vacpage->blkno);
 			LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
 			page = BufferGetPage(buf);
 			num_tuples = 0;
+			maxoff = PageGetMaxOffsetNumber(page);
 			for (offnum = FirstOffsetNumber;
 				 offnum <= maxoff;
 				 offnum = OffsetNumberNext(offnum))
@@ -2061,8 +2061,8 @@ vacuum_heap(VRelStats *vacrelstats, Relation onerel, VacPageList vacuum_pages)
 static void
 vacuum_page(Relation onerel, Buffer buffer, VacPage vacpage)
 {
-	char		unbuf[BLCKSZ];
-	OffsetNumber *unused = (OffsetNumber *) unbuf;
+	OffsetNumber unbuf[BLCKSZ/sizeof(OffsetNumber)];
+	OffsetNumber *unused = unbuf;
 	int			uncnt;
 	Page		page = BufferGetPage(buffer);
 	ItemId		itemid;

src/backend/storage/large_object/inv_api.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/storage/large_object/inv_api.c,v 1.86 2001/03/22 03:59:45 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/storage/large_object/inv_api.c,v 1.87 2001/03/25 23:23:59 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -416,8 +416,11 @@ inv_write(LargeObjectDesc *obj_desc, char *buf, int nbytes)
 	bool		neednextpage;
 	bytea	   *datafield;
 	bool		pfreeit;
-	char		workbuf[LOBLKSIZE + VARHDRSZ];
-	char	   *workb = VARATT_DATA(workbuf);
+	struct {
+		struct varlena	hdr;
+		char			data[LOBLKSIZE];
+	}			workbuf;
+	char	   *workb = VARATT_DATA(&workbuf.hdr);
 	HeapTuple	newtup;
 	Datum		values[Natts_pg_largeobject];
 	char		nulls[Natts_pg_largeobject];
@@ -526,15 +529,15 @@ inv_write(LargeObjectDesc *obj_desc, char *buf, int nbytes)
 			off += n;
 			/* compute valid length of new page */
 			len = (len >= off) ? len : off;
-			VARATT_SIZEP(workbuf) = len + VARHDRSZ;
+			VARATT_SIZEP(&workbuf.hdr) = len + VARHDRSZ;
 
 			/*
 			 * Form and insert updated tuple
 			 */
 			memset(values, 0, sizeof(values));
 			memset(nulls, ' ', sizeof(nulls));
 			memset(replace, ' ', sizeof(replace));
-			values[Anum_pg_largeobject_data - 1] = PointerGetDatum(workbuf);
+			values[Anum_pg_largeobject_data - 1] = PointerGetDatum(&workbuf);
 			replace[Anum_pg_largeobject_data - 1] = 'r';
 			newtup = heap_modifytuple(&oldtuple, obj_desc->heap_r,
 									  values, nulls, replace);
@@ -575,7 +578,7 @@ inv_write(LargeObjectDesc *obj_desc, char *buf, int nbytes)
 			obj_desc->offset += n;
 			/* compute valid length of new page */
 			len = off + n;
-			VARATT_SIZEP(workbuf) = len + VARHDRSZ;
+			VARATT_SIZEP(&workbuf.hdr) = len + VARHDRSZ;
 
 			/*
 			 * Form and insert updated tuple
@@ -584,7 +587,7 @@ inv_write(LargeObjectDesc *obj_desc, char *buf, int nbytes)
 			memset(nulls, ' ', sizeof(nulls));
 			values[Anum_pg_largeobject_loid - 1] = ObjectIdGetDatum(obj_desc->id);
 			values[Anum_pg_largeobject_pageno - 1] = Int32GetDatum(pageno);
-			values[Anum_pg_largeobject_data - 1] = PointerGetDatum(workbuf);
+			values[Anum_pg_largeobject_data - 1] = PointerGetDatum(&workbuf);
 			newtup = heap_formtuple(obj_desc->heap_r->rd_att, values, nulls);
 			heap_insert(obj_desc->heap_r, newtup);
 			if (write_indices)

src/backend/utils/mb/wstrncmp.c

@@ -43,14 +43,12 @@ register const pg_wchar *s1,
 		   *s2;
 register size_t n;
 {
-
 	if (n == 0)
 		return 0;
 	do
 	{
 		if (*s1 != *s2++)
-			return (*(const pg_wchar *) s1 -
-					*(const pg_wchar *) (s2 - 1));
+			return (*s1 - *(s2 - 1));
 		if (*s1++ == 0)
 			break;
 	} while (--n != 0);
@@ -63,14 +61,12 @@ register const char *s1;
 register const pg_wchar *s2;
 register size_t n;
 {
-
 	if (n == 0)
 		return 0;
 	do
 	{
-		if ((pg_wchar) * s1 != *s2++)
-			return (*(const pg_wchar *) s1 -
-					*(const pg_wchar *) (s2 - 1));
+		if ((pg_wchar) ((unsigned char) *s1) != *s2++)
+			return ((pg_wchar) ((unsigned char) *s1) - *(s2 - 1));
 		if (*s1++ == 0)
 			break;
 	} while (--n != 0);
@@ -83,6 +79,7 @@ const pg_wchar *str;
 {
 	register const pg_wchar *s;
 
-	for (s = str; *s; ++s);
+	for (s = str; *s; ++s)
+		;
 	return (s - str);
 }