Silence assorted "variable may be used uninitialized" warnings.

tglsfdc · tglsfdc · commit 9a725f7b5cb7 · 2018-02-14T16:06:49.000-05:00
All of these are false positives, but in each case a fair amount of analysis is needed to see that, and it's not too surprising that not all compilers are smart enough. (In particular, in the logtape.c case, a compiler lacking the knowledge provided by the Assert would almost surely complain, so that this warning will be seen in any non-assert build.) Some of these are of long standing while others are pretty recent, but it only seems worth fixing them in HEAD. Jaime Casanova, tweaked a bit by me Discussion: https://postgr.es/m/CAJGNTeMcYAMJdPAom52dppLMtF-UnEZi0dooj==75OEv1EoBZA@mail.gmail.com
diff --git a/src/backend/access/transam/xloginsert.c b/src/backend/access/transam/xloginsert.c
@@ -584,7 +584,7 @@ XLogRecordAssemble(RmgrId rmid, uint8 info,
 		if (include_image)
 		{
 			Page		page = regbuf->page;
-			uint16		compressed_len;
+			uint16		compressed_len = 0;
 
 			/*
 			 * The page needs to be backed up, so calculate its hole length
diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
@@ -1593,6 +1593,8 @@ get_object_address_opf_member(ObjectType objtype,
 	famaddr = get_object_address_opcf(OBJECT_OPFAMILY, copy, false);
 
 	/* find out left/right type names and OIDs */
+	typenames[0] = typenames[1] = NULL;
+	typeoids[0] = typeoids[1] = InvalidOid;
 	i = 0;
 	foreach(cell, lsecond(object))
 	{
diff --git a/src/backend/utils/sort/logtape.c b/src/backend/utils/sort/logtape.c
@@ -411,7 +411,7 @@ ltsConcatWorkerTapes(LogicalTapeSet *lts, TapeShare *shared,
 					 SharedFileSet *fileset)
 {
 	LogicalTape *lt = NULL;
-	long		tapeblocks;
+	long		tapeblocks = 0L;
 	long		nphysicalblocks = 0L;
 	int			i;
 
diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
@@ -1495,6 +1495,7 @@ coerceToBool(PgBenchValue *pval, bool *bval)
 	else /* NULL, INT or DOUBLE */
 	{
 		fprintf(stderr, "cannot coerce %s to boolean\n", valueTypeName(pval));
+		*bval = false;			/* suppress uninitialized-variable warnings */
 		return false;
 	}
 }
@@ -1725,9 +1726,9 @@ evalLazyFunc(TState *thread, CState *st,
  * which do not require lazy evaluation.
  */
 static bool
-evalStandardFunc(
-	TState *thread, CState *st,
-	PgBenchFunction func, PgBenchExprLink *args, PgBenchValue *retval)
+evalStandardFunc(TState *thread, CState *st,
+				 PgBenchFunction func, PgBenchExprLink *args,
+				 PgBenchValue *retval)
 {
 	/* evaluate all function arguments */
 	int				nargs = 0;

Original file line number	Diff line number	Diff line change
`@@ -584,7 +584,7 @@ XLogRecordAssemble(RmgrId rmid, uint8 info,`
`584`	`584`	`if (include_image)`
`585`	`585`	`{`
`586`	`586`	`Page page = regbuf->page;`
`587`		`- uint16 compressed_len;`
	`587`	`+ uint16 compressed_len = 0;`
`588`	`588`
`589`	`589`	`/*`
`590`	`590`	`* The page needs to be backed up, so calculate its hole length`
Original file line number	Diff line number	Diff line change
`@@ -1593,6 +1593,8 @@ get_object_address_opf_member(ObjectType objtype,`
`1593`	`1593`	`famaddr = get_object_address_opcf(OBJECT_OPFAMILY, copy, false);`
`1594`	`1594`
`1595`	`1595`	`/* find out left/right type names and OIDs */`
	`1596`	`+ typenames[0] = typenames[1] = NULL;`
	`1597`	`+ typeoids[0] = typeoids[1] = InvalidOid;`
`1596`	`1598`	`i = 0;`
`1597`	`1599`	`foreach(cell, lsecond(object))`
`1598`	`1600`	`{`
Original file line number	Diff line number	Diff line change
`@@ -411,7 +411,7 @@ ltsConcatWorkerTapes(LogicalTapeSet lts, TapeShare shared,`
`411`	`411`	`SharedFileSet *fileset)`
`412`	`412`	`{`
`413`	`413`	`LogicalTape *lt = NULL;`
`414`		`- long tapeblocks;`
	`414`	`+ long tapeblocks = 0L;`
`415`	`415`	`long nphysicalblocks = 0L;`
`416`	`416`	`int i;`
`417`	`417`
Original file line number	Diff line number	Diff line change
`@@ -1495,6 +1495,7 @@ coerceToBool(PgBenchValue pval, bool bval)`
`1495`	`1495`	`else /* NULL, INT or DOUBLE */`
`1496`	`1496`	`{`
`1497`	`1497`	`fprintf(stderr, "cannot coerce %s to boolean\n", valueTypeName(pval));`
	`1498`	`+ bval = false; / suppress uninitialized-variable warnings */`
`1498`	`1499`	`return false;`
`1499`	`1500`	`}`
`1500`	`1501`	`}`
`@@ -1725,9 +1726,9 @@ evalLazyFunc(TState thread, CState st,`
`1725`	`1726`	`* which do not require lazy evaluation.`
`1726`	`1727`	`*/`
`1727`	`1728`	`static bool`
`1728`		`-evalStandardFunc(`
`1729`		`- TState thread, CState st,`
`1730`		`- PgBenchFunction func, PgBenchExprLink args, PgBenchValue retval)`
	`1729`	`+evalStandardFunc(TState thread, CState st,`
	`1730`	`+ PgBenchFunction func, PgBenchExprLink *args,`
	`1731`	`+ PgBenchValue *retval)`
`1731`	`1732`	`{`
`1732`	`1733`	`/* evaluate all function arguments */`
`1733`	`1734`	`int nargs = 0;`