[Bug c/53663] New: 4.7 inconsistent inline handling of bool within union

[brendan.jones.it at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53663

             Bug #: 53663
           Summary: 4.7 inconsistent inline handling of bool within union
    Classification: Unclassified
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: brendan.jones...@gmail.com


Please refer to the following:

/* -*- Mode: C ; c-basic-offset: 4 -*- */
/* gcc test_jack.c -Wall -Wextra -o test -O1 && ./test ; echo $?
   should print 0, prints 10
   gcc known to be affected:

Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla
--enable-bootstrap --enable-shared --enable-threads=posix
--enable-checking=release --disable-build-with-cxx
--disable-build-poststage1-with-cxx --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-gnu-unique-object
--enable-linker-build-id --with-linker-hash-style=gnu
--enable-languages=c,c++,objc,obj-c++,java,fortran,ada,go,lto --enable-plugin
--enable-initfini-array --enable-java-awt=gtk --disable-dssi
--with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre
--enable-libgcj-multifile --enable-java-maintainer-mode
--with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libjava-multilib
--with-ppl --with-cloog --with-tune=generic --with-arch_32=i686
--build=x86_64-redhat-linux
Thread model: posix
gcc version 4.7.0 20120507 (Red Hat 4.7.0-5) (GCC) 
*/
#include <stdio.h>
union u
{
    int i = 0;
    _Bool b = 0;
};

void f(union u * vp, union u v)
{
    *vp = v;
}

int main()
{
    union u v = 0;
    union u v1 = 0;
    union u v2 = 0;

    v.i = 10;
    f(&v1, v);

    v.b = 0;
    f(&v2, v);
    if (v2.b) printf("True\n");
    else printf("False\n");
    return v2.b;
}