Hi Lukas,
On Tue, Jul 17, 2018 at 01:08:39PM +0200, Lukas Tribus wrote:
> On Tue, 17 Jul 2018 at 01:09, Thrawn <shell_layer-git...@yahoo.com.au> wrote:
> >
> > Ah, indeed, the GCC version provided on our server is 3.4.3. But the readme
> > on https://github.com/haproxy/haproxy says "GCC between 2.95 and 4.8". Can
> > the build be changed to continue supporting older GCC, or do the docs need
> > an update?
>
> Like I said earlier, "make clean" before compiling with different
> parameters, like USE_THREAD=
>
> Haproxy 1.8 is supposed to build fine with gcc 3 when disabling
> threading, but if you just compiled with threads enabled, you do need
> to "make clean":
>
>
> > I think your gcc is just too old. Those appeared around gcc 4.1 or so.
>
> With USE_THREAD= it is supposed to build fine. While threading will
> not work with gcc 3, we did not drop support for gcc3 altogether.
>
>
Unfortunately it is not true. __sync_* was used in include/proto/shctx.h.
The attached patch uses the haproxy macroes instead, and so should get it
to compile again with older gcc. Thrawn, can you please test it ?
Thanks !
Olivier
>From 91546285ceed74516f42a9e98fac14a5094133e0 Mon Sep 17 00:00:00 2001
From: Olivier Houchard <ohouch...@haproxy.com>
Date: Tue, 17 Jul 2018 13:52:19 +0200
Subject: [PATCH] MINOR: shctx: Use HA_ATOMIC_* instead of using the gcc
builtins.
When implementing atomic operations, use the HA_ATOMIC macroes provided by
hathreads.h, instead of using the (old) gcc builtins. That way it may uses
the newer builtins, or get it to compile with an old gcc that doesn't provide
any atomic builtins.
---
include/proto/shctx.h | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/include/proto/shctx.h b/include/proto/shctx.h
index 55cb2a77..4eed582b 100644
--- a/include/proto/shctx.h
+++ b/include/proto/shctx.h
@@ -132,17 +132,18 @@ static inline unsigned char atomic_dec(unsigned int *ptr)
#else /* if no x86_64 or i586 arch: use less optimized gcc >= 4.1 built-ins */
static inline unsigned int xchg(unsigned int *ptr, unsigned int x)
{
- return __sync_lock_test_and_set(ptr, x);
+ return HA_ATOMIC_XCHG(ptr, x);
}
static inline unsigned int cmpxchg(unsigned int *ptr, unsigned int old,
unsigned int new)
{
- return __sync_val_compare_and_swap(ptr, old, new);
+ HA_ATOMIC_CAS(ptr, &old, new);
+ return old;
}
static inline unsigned char atomic_dec(unsigned int *ptr)
{
- return __sync_sub_and_fetch(ptr, 1) ? 1 : 0;
+ return HA_ATOMIC_SUB(ptr, 1) ? 1 : 0;
}
#endif
--
2.14.3
