Re: [PATCH 0/6] pull: almost working AddressSanitizer support

[Boris Egorov <egorov@linux.com>]

Hello,

On 11/11/2014 03:49 AM, Sami Kerola wrote:

> The short description is: when the code is at very last line of mkswap at
> 'return EXIT_SUCCESS;' somehow the EXIT_SUCCESS is 1.  If I change the
> 'return EXIT_SUCCESS;' to 'exit(EXIT_SUCCESS);' the return value stays
> expected.  Possible explanations include:
That's interesting.

> 1. I'm doing something silly and/or wrong.
I doubt it.

> 2. This happens only on my laptop (or imagination).  Please, let it not
>     be this.
No, I can confirm: It works as you describe with clang-3.5.0 from Debian 
Jessie. Returns 1 with ld.bfd too.

> 3. This is a bug in clang, llvm, and/or AddressSanitizer.
>     clang / llvm version 3.5.0 from Archlinux packages 3.5.0-2.1
Probably it is.

> 4. With gcc 4.9.2 and the same CFLAGS the mkswap works.
Confirmed with gcc 4.9.1.

I found more info: problem connected with atexit(close_stdout). If I 
comment this line, mkswap exits normally. Looks like close_stdout ends 
successfully (I've made it not inline and checked it with gdb), but then 
program exits with code 1.

Also, there is a problem building mkswap with clang on my machine. 
autoconf test for HAVE_SCANF_MS_MODIFIER is incomplete. clang/llvm have 
%m modifier (I've checked it), but this test fails to detect it. Test 
for HAVE_SCANF_AS_MODIFIER fails too, I suppose. So when I build mkswap 
I have an error:

     lib/colors.c:620:19: error: use of undeclared identifier 'UL_SCNsA'
                     rc = sscanf(p,  UL_SCNsA" "     /* name */

So, we need to detect %m modifier with clang on build somehow.

PS. Forgot to add mail list on reply, resending message. Sorry for the 
duplicate, Sami.

-- 
Best Regards,
Boris Egorov