psql: Fix some scan-build warnings

petere · petere · commit 390edeeb570c · 2021-10-12T21:20:29.000+02:00
A repeated complaint was that scan-build thought that if the \timing setting changes during processing of a query, the post-processing might read garbage time values. This is probably not possible right now, but it's not entirely inconceivable given the code structure. So silence this warning with small restructuring that makes this more robust. The other warnings were a few dead stores that are easy to remove. Discussion: https://www.postgresql.org/message-id/2570e2ae-fa0f-aac9-f72f-bb59a9983a20@enterprisedb.com
diff --git a/src/bin/psql/common.c b/src/bin/psql/common.c
@@ -594,6 +594,7 @@ PSQLexec(const char *query)
 int
 PSQLexecWatch(const char *query, const printQueryOpt *opt, FILE *printQueryFout)
 {
+	bool		timing = pset.timing;
 	PGresult   *res;
 	double		elapsed_msec = 0;
 	instr_time	before;
@@ -608,7 +609,7 @@ PSQLexecWatch(const char *query, const printQueryOpt *opt, FILE *printQueryFout)
 
 	SetCancelConn(pset.db);
 
-	if (pset.timing)
+	if (timing)
 		INSTR_TIME_SET_CURRENT(before);
 
 	res = PQexec(pset.db, query);
@@ -621,7 +622,7 @@ PSQLexecWatch(const char *query, const printQueryOpt *opt, FILE *printQueryFout)
 		return 0;
 	}
 
-	if (pset.timing)
+	if (timing)
 	{
 		INSTR_TIME_SET_CURRENT(after);
 		INSTR_TIME_SUBTRACT(after, before);
@@ -674,7 +675,7 @@ PSQLexecWatch(const char *query, const printQueryOpt *opt, FILE *printQueryFout)
 	fflush(fout);
 
 	/* Possible microtiming output */
-	if (pset.timing)
+	if (timing)
 		PrintTiming(elapsed_msec);
 
 	return 1;
@@ -1192,6 +1193,7 @@ PrintQueryResults(PGresult *results)
 bool
 SendQuery(const char *query)
 {
+	bool		timing = pset.timing;
 	PGresult   *results;
 	PGTransactionStatusType transaction_status;
 	double		elapsed_msec = 0;
@@ -1300,7 +1302,7 @@ SendQuery(const char *query)
 		instr_time	before,
 					after;
 
-		if (pset.timing)
+		if (timing)
 			INSTR_TIME_SET_CURRENT(before);
 
 		results = PQexec(pset.db, query);
@@ -1309,7 +1311,7 @@ SendQuery(const char *query)
 		ResetCancelConn();
 		OK = ProcessResult(&results);
 
-		if (pset.timing)
+		if (timing)
 		{
 			INSTR_TIME_SET_CURRENT(after);
 			INSTR_TIME_SUBTRACT(after, before);
@@ -1400,7 +1402,7 @@ SendQuery(const char *query)
 	ClearOrSaveResult(results);
 
 	/* Possible microtiming output */
-	if (pset.timing)
+	if (timing)
 		PrintTiming(elapsed_msec);
 
 	/* check for events that may occur during query execution */
@@ -1471,14 +1473,15 @@ SendQuery(const char *query)
 static bool
 DescribeQuery(const char *query, double *elapsed_msec)
 {
+	bool		timing = pset.timing;
 	PGresult   *results;
 	bool		OK;
 	instr_time	before,
 				after;
 
 	*elapsed_msec = 0;
 
-	if (pset.timing)
+	if (timing)
 		INSTR_TIME_SET_CURRENT(before);
 
 	/*
@@ -1550,7 +1553,7 @@ DescribeQuery(const char *query, double *elapsed_msec)
 			results = PQexec(pset.db, buf.data);
 			OK = AcceptResult(results);
 
-			if (pset.timing)
+			if (timing)
 			{
 				INSTR_TIME_SET_CURRENT(after);
 				INSTR_TIME_SUBTRACT(after, before);
@@ -1591,6 +1594,7 @@ ExecQueryUsingCursor(const char *query, double *elapsed_msec)
 	PGresult   *results;
 	PQExpBufferData buf;
 	printQueryOpt my_popt = pset.popt;
+	bool		timing = pset.timing;
 	FILE	   *fout;
 	bool		is_pipe;
 	bool		is_pager = false;
@@ -1610,7 +1614,7 @@ ExecQueryUsingCursor(const char *query, double *elapsed_msec)
 	my_popt.topt.stop_table = false;
 	my_popt.topt.prior_records = 0;
 
-	if (pset.timing)
+	if (timing)
 		INSTR_TIME_SET_CURRENT(before);
 
 	/* if we're not in a transaction, start one */
@@ -1640,7 +1644,7 @@ ExecQueryUsingCursor(const char *query, double *elapsed_msec)
 	if (!OK)
 		goto cleanup;
 
-	if (pset.timing)
+	if (timing)
 	{
 		INSTR_TIME_SET_CURRENT(after);
 		INSTR_TIME_SUBTRACT(after, before);
@@ -1682,13 +1686,13 @@ ExecQueryUsingCursor(const char *query, double *elapsed_msec)
 
 	for (;;)
 	{
-		if (pset.timing)
+		if (timing)
 			INSTR_TIME_SET_CURRENT(before);
 
 		/* get fetch_count tuples at a time */
 		results = PQexec(pset.db, fetch_cmd);
 
-		if (pset.timing)
+		if (timing)
 		{
 			INSTR_TIME_SET_CURRENT(after);
 			INSTR_TIME_SUBTRACT(after, before);
@@ -1802,7 +1806,7 @@ ExecQueryUsingCursor(const char *query, double *elapsed_msec)
 	}
 
 cleanup:
-	if (pset.timing)
+	if (timing)
 		INSTR_TIME_SET_CURRENT(before);
 
 	/*
@@ -1828,7 +1832,7 @@ ExecQueryUsingCursor(const char *query, double *elapsed_msec)
 		ClearOrSaveResult(results);
 	}
 
-	if (pset.timing)
+	if (timing)
 	{
 		INSTR_TIME_SET_CURRENT(after);
 		INSTR_TIME_SUBTRACT(after, before);
diff --git a/src/bin/psql/copy.c b/src/bin/psql/copy.c
@@ -660,7 +660,6 @@ handleCopyIn(PGconn *conn, FILE *copystream, bool isbinary, PGresult **res)
 				if (PQputCopyData(conn, buf, buflen) <= 0)
 				{
 					OK = false;
-					copydone = true;
 					break;
 				}
 
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
@@ -635,7 +635,6 @@ describeFunctions(const char *functypes, const char *func_pattern,
 				appendPQExpBufferStr(&buf, "p.prokind = 'w'\n");
 			else
 				appendPQExpBufferStr(&buf, "p.proiswindow\n");
-			needs_or = true;
 		}
 		appendPQExpBufferStr(&buf, "      )\n");
 	}

Original file line number	Diff line number	Diff line change
`@@ -660,7 +660,6 @@ handleCopyIn(PGconn conn, FILE copystream, bool isbinary, PGresult **res)`
`660`	`660`	`if (PQputCopyData(conn, buf, buflen) <= 0)`
`661`	`661`	`{`
`662`	`662`	`OK = false;`
`663`		`- copydone = true;`
`664`	`663`	`break;`
`665`	`664`	`}`
`666`	`665`
Original file line number	Diff line number	Diff line change
`@@ -635,7 +635,6 @@ describeFunctions(const char functypes, const char func_pattern,`
`635`	`635`	`appendPQExpBufferStr(&buf, "p.prokind = 'w'\n");`
`636`	`636`	`else`
`637`	`637`	`appendPQExpBufferStr(&buf, "p.proiswindow\n");`
`638`		`- needs_or = true;`
`639`	`638`	`}`
`640`	`639`	`appendPQExpBufferStr(&buf, " )\n");`
`641`	`640`	`}`