From: Mark Andrews <marka@isc.org>
Date: Tue, 1 Oct 2019 04:06:53 +0000 (+1000)
Subject: silence clang warning by using local variable.
X-Git-Tag: v9.15.6~70^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1b27ab8642a43617d1359375d1cff7afd5bd79e3;p=thirdparty%2Fbind9.git

silence clang warning by using local variable.

'isc_commandline_index' is a global variable so it can theoretically
change result between if expressions.  Save 'argv[isc_commandline_index]'
to local variable 'arg1' and use 'arg1 == NULL' in if expressions
instead of 'argc < isc_commandline_index + 1'.  This allows clang
to correctly determine what code is reachable.
---

diff --git a/bin/dnssec/dnssec-dsfromkey.c b/bin/dnssec/dnssec-dsfromkey.c
index 47a5124b2a5..4923fe6e8a9 100644
--- a/bin/dnssec/dnssec-dsfromkey.c
+++ b/bin/dnssec/dnssec-dsfromkey.c
@@ -332,7 +332,7 @@ int
 main(int argc, char **argv) {
 	char		*classname = NULL;
 	char		*filename = NULL, *dir = NULL, *namestr;
-	char		*endp;
+	char		*endp, *arg1;
 	int		ch;
 	bool		cds = false;
 	bool		usekeyset = false;
@@ -444,10 +444,15 @@ main(int argc, char **argv) {
 		dtype[0] = DNS_DSDIGEST_SHA256;
 	}
 
-	if (argc < isc_commandline_index + 1 && filename == NULL) {
+	/*
+	 * Use local variable arg1 so that clang can correctly analyse
+	 * reachable paths rather than 'argc < isc_commandline_index + 1'.
+	 */
+	arg1 = argv[isc_commandline_index];
+	if (arg1 == NULL && filename == NULL) {
 		fatal("the key file name was not specified");
 	}
-	if (argc > isc_commandline_index + 1) {
+	if (arg1 != NULL && argv[isc_commandline_index + 1] != NULL) {
 		fatal("extraneous arguments");
 	}
 
@@ -462,11 +467,11 @@ main(int argc, char **argv) {
 	dns_rdataset_init(&rdataset);
 
 	if (usekeyset || filename != NULL) {
-		if (argc < isc_commandline_index + 1) {
-			/* using zone name as the zone file name */
+		if (arg1 == NULL) {
+			/* using file name as the zone name */
 			namestr = filename;
 		} else {
-			namestr = argv[isc_commandline_index];
+			namestr = arg1;
 		}
 
 		result = initname(namestr);
@@ -502,8 +507,7 @@ main(int argc, char **argv) {
 	} else {
 		unsigned char key_buf[DST_KEY_MAXSIZE];
 
-		loadkey(argv[isc_commandline_index], key_buf,
-			DST_KEY_MAXSIZE, &rdata);
+		loadkey(arg1, key_buf, DST_KEY_MAXSIZE, &rdata);
 
 		emits(showall, cds, &rdata);
 	}