From: Willy Tarreau <w@1wt.eu>
Date: Sun, 26 May 2019 09:50:08 +0000 (+0200)
Subject: BUILD: connections: shut up gcc about impossible out-of-bounds warning
X-Git-Tag: v2.0-dev5~66
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=08e2b41e8183bede36f4fca1b8f849f18e4be13e;p=thirdparty%2Fhaproxy.git

BUILD: connections: shut up gcc about impossible out-of-bounds warning

Since commit 88698d9 ("MEDIUM: connections: Add a way to control the
number of idling connections.") when building without threads, gcc
complains that the operations made on the idle_orphan_conns[] list is
out of bounds, which is always false since 1) <i> can only equal zero,
and 2) given it's equal to <tid> we never even enter the loop. But as
usual it thinks it knows better, so let's mask the origin of this <i>
value to shut it up. Another solution consists in making <i> unsigned
and adding an explicit range check.
---

diff --git a/src/backend.c b/src/backend.c
index 467ef57a9b..4dff185ec5 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -1354,6 +1354,13 @@ int connect_server(struct stream *s)
 			for (i = 0; i < global.nbthread; i++) {
 				if (i == tid)
 					continue;
+
+				// just silence stupid gcc which reports an absurd
+				// out-of-bounds warning for <i> which is always
+				// exactly zero without threads, but it seems to
+				// see it possibly larger.
+				ALREADY_CHECKED(i);
+
 				tokill_conn = LIST_POP_LOCKED(&srv->idle_orphan_conns[i],
 				    struct connection *, list);
 				if (tokill_conn) {