From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-348700-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 4762 invoked by alias); 1 Mar 2011 06:45:31 -0000
Received: (qmail 4752 invoked by uid 22791); 1 Mar 2011 06:45:31 -0000
X-SWARE-Spam-Status: No, hits=-2.8 required=5.0	tests=ALL_TRUSTED,AWL,BAYES_00
X-Spam-Check-By: sourceware.org
Received: from localhost (HELO gcc.gnu.org) (127.0.0.1)    by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 01 Mar 2011 06:45:27 +0000
From: "d.g.gorbachev at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug lto/47934] New: LTO: function with attribute "used" is not emitted
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: lto
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: d.g.gorbachev at gmail dot com
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Changed-Fields:
Message-ID: <bug-47934-4@http.gcc.gnu.org/bugzilla/>
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
Content-Type: text/plain; charset="UTF-8"
MIME-Version: 1.0
Date: Tue, 01 Mar 2011 06:45:00 -0000
Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Id: <gcc-bugs.gcc.gnu.org>
List-Archive: <http://gcc.gnu.org/ml/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-help@gcc.gnu.org>
Sender: gcc-bugs-owner@gcc.gnu.org
X-SW-Source: 2011-03/txt/msg00013.txt.bz2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47934

           Summary: LTO: function with attribute "used" is not emitted
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: lto
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: d.g.gorbachev@gmail.com


============= bug.c =============
static void __attribute__((used)) 
foo(void) 
{ 
}

int main(void)
{
  __asm__("call foo");
  return 0;
}
=================================

$ gcc -flto bug.c
/tmp/ccCtTmmT.ltrans0.ltrans.o: In function `main':
ccCtTmmT.ltrans0.o:(.text+0x4): undefined reference to `foo'
collect2: ld returned 1 exit status

>>From GCC documentation:

`used'
     This attribute, attached to a function, means that code must be
     emitted for the function even if it appears that the function is
     not referenced.  This is useful, for example, when the function is
     referenced only in inline assembly.