Yet more elimination of dead stores and useless initializations.

I'm not sure what tool Ranier was using, but the ones I contributed
were found by using a newer version of scan-build than I tried before.

Ranier Vilela and Tom Lane

Discussion: https://postgr.es/m/CAEudQAo1+AcGppxDSg8k+zF4+Kv+eJyqzEDdbpDg58-=MQcerQ@mail.gmail.com

src/backend/access/common/heaptuple.c

@@ -736,7 +736,7 @@ expand_tuple(HeapTuple *targetHeapTuple,
 {
 	AttrMissing *attrmiss = NULL;
 	int			attnum;
-	int			firstmissingnum = 0;
+	int			firstmissingnum;
 	bool		hasNulls = HeapTupleHasNulls(sourceTuple);
 	HeapTupleHeader targetTHeader;
 	HeapTupleHeader sourceTHeader = sourceTuple->t_data;

src/backend/access/gist/gistutil.c

@@ -32,7 +32,6 @@
 void
 gistfillbuffer(Page page, IndexTuple *itup, int len, OffsetNumber off)
 {
-	OffsetNumber l = InvalidOffsetNumber;
 	int			i;
 
 	if (off == InvalidOffsetNumber)
@@ -42,6 +41,7 @@ gistfillbuffer(Page page, IndexTuple *itup, int len, OffsetNumber off)
 	for (i = 0; i < len; i++)
 	{
 		Size		sz = IndexTupleSize(itup[i]);
+		OffsetNumber l;
 
 		l = PageAddItem(page, (Item) itup[i], sz, off, false, false);
 		if (l == InvalidOffsetNumber)

src/backend/access/nbtree/nbtsearch.c

@@ -860,7 +860,7 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
 	ScanKeyData notnullkeys[INDEX_MAX_KEYS];
 	int			keysCount = 0;
 	int			i;
-	bool		status = true;
+	bool		status;
 	StrategyNumber strat_total;
 	BTScanPosItem *currItem;
 	BlockNumber blkno;
@@ -1858,7 +1858,7 @@ _bt_steppage(IndexScanDesc scan, ScanDirection dir)
 {
 	BTScanOpaque so = (BTScanOpaque) scan->opaque;
 	BlockNumber blkno = InvalidBlockNumber;
-	bool		status = true;
+	bool		status;
 
 	Assert(BTScanPosIsValid(so->currPos));
 
@@ -1967,7 +1967,7 @@ _bt_readnextpage(IndexScanDesc scan, BlockNumber blkno, ScanDirection dir)
 	Relation	rel;
 	Page		page;
 	BTPageOpaque opaque;
-	bool		status = true;
+	bool		status;
 
 	rel = scan->indexRelation;
 

src/backend/catalog/storage.c

@@ -599,7 +599,6 @@ smgrDoPendingDeletes(bool isCommit)
 	PendingRelDelete *prev;
 	PendingRelDelete *next;
 	int			nrels = 0,
-				i = 0,
 				maxrels = 0;
 	SMgrRelation *srels = NULL;
 
@@ -650,7 +649,7 @@ smgrDoPendingDeletes(bool isCommit)
 	{
 		smgrdounlinkall(srels, nrels, false);
 
-		for (i = 0; i < nrels; i++)
+		for (int i = 0; i < nrels; i++)
 			smgrclose(srels[i]);
 
 		pfree(srels);

src/backend/commands/async.c

@@ -1918,7 +1918,6 @@ static void
 asyncQueueReadAllNotifications(void)
 {
 	volatile QueuePosition pos;
-	QueuePosition oldpos;
 	QueuePosition head;
 	Snapshot	snapshot;
 
@@ -1933,7 +1932,7 @@ asyncQueueReadAllNotifications(void)
 	LWLockAcquire(NotifyQueueLock, LW_SHARED);
 	/* Assert checks that we have a valid state entry */
 	Assert(MyProcPid == QUEUE_BACKEND_PID(MyBackendId));
-	pos = oldpos = QUEUE_BACKEND_POS(MyBackendId);
+	pos = QUEUE_BACKEND_POS(MyBackendId);
 	head = QUEUE_HEAD;
 	LWLockRelease(NotifyQueueLock);
 

src/backend/storage/ipc/procarray.c

@@ -3433,7 +3433,6 @@ CancelDBBackends(Oid databaseid, ProcSignalReason sigmode, bool conflictPending)
 {
 	ProcArrayStruct *arrayP = procArray;
 	int			index;
-	pid_t		pid = 0;
 
 	/* tell all backends to die */
 	LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
@@ -3446,6 +3445,7 @@ CancelDBBackends(Oid databaseid, ProcSignalReason sigmode, bool conflictPending)
 		if (databaseid == InvalidOid || proc->databaseId == databaseid)
 		{
 			VirtualTransactionId procvxid;
+			pid_t		pid;
 
 			GET_VXID_FROM_PGPROC(procvxid, *proc);
 

src/backend/tsearch/spell.c

@@ -1710,7 +1710,7 @@ void
 NISortDictionary(IspellDict *Conf)
 {
 	int			i;
-	int			naffix = 0;
+	int			naffix;
 	int			curaffix;
 
 	/* compress affixes */

src/backend/utils/adt/formatting.c

@@ -1510,8 +1510,7 @@ static const char *
 get_th(char *num, int type)
 {
 	int			len = strlen(num),
-				last,
-				seclast;
+				last;
 
 	last = *(num + (len - 1));
 	if (!isdigit((unsigned char) last))
@@ -1523,7 +1522,7 @@ get_th(char *num, int type)
 	 * All "teens" (<x>1[0-9]) get 'TH/th', while <x>[02-9][123] still get
 	 * 'ST/st', 'ND/nd', 'RD/rd', respectively
 	 */
-	if ((len > 1) && ((seclast = num[len - 2]) == '1'))
+	if ((len > 1) && (num[len - 2] == '1'))
 		last = 0;
 
 	switch (last)
@@ -4932,9 +4931,9 @@ NUM_cache(int len, NUMDesc *Num, text *pars_str, bool *shouldFree)
 static char *
 int_to_roman(int number)
 {
-	int			len = 0,
-				num = 0;
-	char	   *p = NULL,
+	int			len,
+				num;
+	char	   *p,
 			   *result,
 				numstr[12];
 
@@ -4950,7 +4949,7 @@ int_to_roman(int number)
 
 	for (p = numstr; *p != '\0'; p++, --len)
 	{
-		num = *p - 49;			/* 48 ascii + 1 */
+		num = *p - ('0' + 1);
 		if (num < 0)
 			continue;
 
@@ -6118,7 +6117,7 @@ numeric_to_char(PG_FUNCTION_ARGS)
 		x = DatumGetNumeric(DirectFunctionCall2(numeric_round,
 												NumericGetDatum(value),
 												Int32GetDatum(0)));
-		numstr = orgnum =
+		numstr =
 			int_to_roman(DatumGetInt32(DirectFunctionCall1(numeric_int4,
 														   NumericGetDatum(x))));
 	}
@@ -6239,7 +6238,7 @@ int4_to_char(PG_FUNCTION_ARGS)
 	 * On DateType depend part (int32)
 	 */
 	if (IS_ROMAN(&Num))
-		numstr = orgnum = int_to_roman(value);
+		numstr = int_to_roman(value);
 	else if (IS_EEEE(&Num))
 	{
 		/* we can do it easily because float8 won't lose any precision */
@@ -6335,7 +6334,7 @@ int8_to_char(PG_FUNCTION_ARGS)
 	if (IS_ROMAN(&Num))
 	{
 		/* Currently don't support int8 conversion to roman... */
-		numstr = orgnum = int_to_roman(DatumGetInt32(DirectFunctionCall1(int84, Int64GetDatum(value))));
+		numstr = int_to_roman(DatumGetInt32(DirectFunctionCall1(int84, Int64GetDatum(value))));
 	}
 	else if (IS_EEEE(&Num))
 	{

src/backend/utils/adt/tsrank.c

@@ -857,8 +857,7 @@ calc_rank_cd(const float4 *arrdata, TSVector txt, TSQuery query, int method)
 	double		Wdoc = 0.0;
 	double		invws[lengthof(weights)];
 	double		SumDist = 0.0,
-				PrevExtPos = 0.0,
-				CurExtPos = 0.0;
+				PrevExtPos = 0.0;
 	int			NExtent = 0;
 	QueryRepresentation qr;
 
@@ -889,6 +888,7 @@ calc_rank_cd(const float4 *arrdata, TSVector txt, TSQuery query, int method)
 	{
 		double		Cpos = 0.0;
 		double		InvSum = 0.0;
+		double		CurExtPos;
 		int			nNoise;
 		DocRepresentation *ptr = ext.begin;
 

src/bin/pg_dump/pg_backup_custom.c

@@ -619,7 +619,6 @@ _skipData(ArchiveHandle *AH)
 	size_t		blkLen;
 	char	   *buf = NULL;
 	int			buflen = 0;
-	size_t		cnt;
 
 	blkLen = ReadInt(AH);
 	while (blkLen != 0)
@@ -638,7 +637,7 @@ _skipData(ArchiveHandle *AH)
 				buf = (char *) pg_malloc(blkLen);
 				buflen = blkLen;
 			}
-			if ((cnt = fread(buf, 1, blkLen, AH->FH)) != blkLen)
+			if (fread(buf, 1, blkLen, AH->FH) != blkLen)
 			{
 				if (feof(AH->FH))
 					fatal("could not read from input file: end of file");
@@ -664,9 +663,7 @@ _skipData(ArchiveHandle *AH)
 static int
 _WriteByte(ArchiveHandle *AH, const int i)
 {
-	int			res;
-
-	if ((res = fputc(i, AH->FH)) == EOF)
+	if (fputc(i, AH->FH) == EOF)
 		WRITE_ERROR_EXIT;
 
 	return 1;