AC_REPLACE_FUNCS is not -Werror safe

[Kamaraju Kusumanchi]

I am unable to compile gdb-7.2 using gcc-4.6 with the -Werror option
on a Debian sid machine. When I reported the bug to gdb maintainers as
http://sourceware.org/bugzilla/show_bug.cgi?id=12891 , they informed
me that the bug is actually in autoconf package. It seems libiberty in
gdb-7.2 uses AC_REPLACE_FUNCS and apparently this is not -Werror safe.

For the reference, I am attaching the gdb-7.2/libiberty/configure
script and the gdb-7.2/build/objdir/libiberty/config.log in this
email.

This is the first time I am reporting a bug in autoconf. So, please
let me know if you need any additional info.

debian_chroot:sid:kusumanchi:/home/gdb/gdb-7.2# gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/i386-linux-gnu/gcc/i486-linux-gnu/4.6.1/lto-wrapper
Target: i486-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian
4.6.0-14' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++,go --prefix=/usr
--program-suffix=-4.6 --enable-shared --enable-multiarch
--with-multiarch-defaults=i386-linux-gnu --enable-linker-build-id
--with-system-zlib --libexecdir=/usr/lib/i386-linux-gnu
--without-included-gettext --enable-threads=posix
--with-gxx-include-dir=/usr/include/c++/4.6
--libdir=/usr/lib/i386-linux-gnu --enable-nls --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-plugin
--enable-objc-gc --enable-targets=all --with-arch-32=i586
--with-tune=generic --enable-checking=release --build=i486-linux-gnu
--host=i486-linux-gnu --target=i486-linux-gnu
Thread model: posix
gcc version 4.6.1 20110616 (prerelease) (Debian 4.6.0-14)


debian_chroot:sid:kusumanchi:/home/gdb/gdb-7.2/gdb-7.2# dpkg -l autoconf
ii  autoconf                                      2.68-1
                         automatic configure script builder

debian_chroot:sid:kusumanchi:/home/gdb/gdb-7.2/gdb-7.2# uname -a
Linux kusumanchi.mae.cornell.edu 2.6.38-2-686 #1 SMP Sun May 8
14:49:45 UTC 2011 i686 GNU/Linux

In the config.log, we see

configure:5913: checking for vfprintf
configure:5913: i486-linux-gnu-gcc -o conftest -g -Werror     conftest.c  >&5
conftest.c:86:6: error: conflicting types for built-in function
'vfprintf' [-Werror]
cc1: all warnings being treated as errors

The relevant conftest.c is also attached.

debian_chroot:sid:kusumanchi:/home/gdb/gdb-7.2# gcc-4.6 -o conftest -g
-Werror conftest.c
conftest.c:86:6: error: conflicting types for built-in function
‘vfprintf’ [-Werror]
cc1: all warnings being treated as errors

debian_chroot:sid:kusumanchi:/home/gdb/gdb-7.2# gcc-4.5 -o conftest -g
-Werror conftest.c
cc1: warnings being treated as errors
conftest.c:86:6: error: conflicting types for built-in function ‘vfprintf’
debian_chroot:sid:kusumanchi:/home/gdb/gdb-7.2# gcc-4.4 -o conftest -g
-Werror conftest.c
cc1: warnings being treated as errors
conftest.c:86: error: conflicting types for built-in function ‘vfprintf’


regards
raju
-- 
Kamaraju S. Kusumanchi
http://malayamaarutham.blogspot.com/

conftest.c
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configure.gz
Description: Binary data

config.log.gz
Description: Binary data