[Bug c++/64369] New: Wreturn-local-addr for const argument with packed attribute

[a3at.mail at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64369

            Bug ID: 64369
           Summary: Wreturn-local-addr for const argument with packed
                    attribute
           Product: gcc
           Version: 4.9.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: a3at.mail at gmail dot com

Created attachment 34306
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34306&action=edit
Werror=return-local-addr

Here is simple test case (also in attachment):
#ifdef NOWARN
#define __packed
#else
#define __packed __attribute__((packed));
#endif

struct Addr
{    
    int s_addr;
};   
struct R1
{    
    Addr addr;                                                                  
} __packed;

const Addr& ipAddress(const R1 &r) { return r.addr; }

void foo()
{    
    R1 r1;
    (void)ipAddress(r1).s_addr;
}

And here is the compiler output for gcc/clang:
$ for c in clang++-3.5 g++; do echo =====$c && $c --version && $c -c test.cpp;
done
=====clang++-3.5
Debian clang version 3.5.0-8 (tags/RELEASE_350/final) (based on LLVM 3.5.0)
Target: x86_64-pc-linux-gnu
Thread model: posix
=====g++
g++ (Debian 4.9.1-19) 4.9.1
Copyright (C) 2014 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

test.cpp: In function ‘const Addr& ipAddress(const R1&)’:
test.cpp:16:47: warning: returning reference to temporary [-Wreturn-local-addr]
 const Addr& ipAddress(const R1 &r) { return r.addr; }
                                               ^

Is this is the correct behavior or what?