From: Willy Tarreau <w@1wt.eu>
Date: Fri, 28 Jan 2022 08:42:29 +0000 (+0100)
Subject: BUILD: tools: fix warning about incorrect cast with dladdr1()
X-Git-Tag: v2.6-dev1~28
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f3d5c4b032274e4b5e1879a616e93890043349f6;p=thirdparty%2Fhaproxy.git

BUILD: tools: fix warning about incorrect cast with dladdr1()

dladdr1() is used on glibc and takes a void**, but we pass it a
const ElfW(Sym)** and some compilers complain that we're aliasing.
Let's just set a may_alias attribute on the local variable to
address this. There's no need to backport this unless warnings are
reported on older distros or uncommon compilers.
---

diff --git a/src/tools.c b/src/tools.c
index aa90341b21..eca7aa8e2c 100644
--- a/src/tools.c
+++ b/src/tools.c
@@ -4814,7 +4814,7 @@ static int dladdr_and_size(const void *addr, Dl_info *dli, size_t *size)
 {
 	int ret;
 #if defined(__GLIBC__) && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3)) // most detailed one
-	const ElfW(Sym) *sym;
+	const ElfW(Sym) *sym __attribute__((may_alias));
 
 	ret = dladdr1(addr, dli, (void **)&sym, RTLD_DL_SYMENT);
 	if (ret)