Re: configure fails with gcc 4.6.0 LTO

[Zeev Tarantov]

On Sat, Mar 19, 2011 at 21:33, Chet Ramey <chet.ramey@case.edu> wrote:
> On 3/18/11 9:42 PM, Zeev Tarantov wrote:
>
>> x86_64-pc-linux-gnu-gcc: error: \: No such file or directory
>> x86_64-pc-linux-gnu-gcc: error: \: No such file or directory
>> x86_64-pc-linux-gnu-gcc: error: \: No such file or directory
>> x86_64-pc-linux-gnu-gcc: error: \: No such file or directory
>> lto-wrapper: 
>> /usr/x86_64-pc-linux-gnu/gcc-bin/4.6.0-pre9999/x86_64-pc-linux-gnu-gcc
>> returned 1 exit status
>> /usr/lib/gcc/x86_64-pc-linux-gnu/4.6.0-pre9999/../../../../x86_64-pc-linux-gnu/bin/ld:
>> lto-wrapper failed
>
> It would be helpful to see the exact command that caused this error, in
> its unexpanded state.

I'm sorry, I do not understand you.
The lines immediately preceding the lines you have quoted are the command.

Configure was invoked this way:

generated by GNU Autoconf 2.63.  Invocation command line was

  $ ./configure --prefix=/usr --build=x86_64-pc-linux-gnu
--host=x86_64-pc-linux-gnu --mandir=/usr/share/man
--infodir=/usr/share/info --datadir=/usr/share --sysconfdir=/etc
--localstatedir=/var/lib --libdir=/usr/lib64 --without-afs
--enable-net-redirections --disable-profiling --disable-mem-scramble
--without-bash-malloc --without-installed-readline --disable-nls
--with-curses

The only thing that is _relevant_ I think is that gcc 4.6 trunk
invoked with LTO fails configure.

I have just reproduced this with minimal flags ("-g -O2 -flto"):

gcc version 4.6.0-pre9999 20110319 (prerelease) rev. 171177 (Gentoo SVN)
configure:3088: $? = 0
configure:3095: x86_64-pc-linux-gnu-gcc -V >&5
x86_64-pc-linux-gnu-gcc: error: unrecognized option '-V'
x86_64-pc-linux-gnu-gcc: fatal error: no input files
compilation terminated.
configure:3099: $? = 1
configure:3122: checking for C compiler default output file name
configure:3144: x86_64-pc-linux-gnu-gcc -g -O2 -flto
-DDEFAULT_PATH_VALUE='"/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"'
-DSTANDARD_UTILS_PATH='"/bin:/usr/bin:/sbin:/usr/sbin"'
-DSYS_BASHRC='"/etc/bash/bashrc"'
-DSYS_BASH_LOGOUT='"/etc/bash/bash_logout"'
-DNON_INTERACTIVE_LOGIN_SHELLS -DSSH_SOURCE_BASHRC -Wl,-flto
conftest.c  >&5
x86_64-pc-linux-gnu-gcc: error: \: No such file or directory
x86_64-pc-linux-gnu-gcc: error: \: No such file or directory
x86_64-pc-linux-gnu-gcc: error: \: No such file or directory
x86_64-pc-linux-gnu-gcc: error: \: No such file or directory
lto-wrapper: 
/usr/x86_64-pc-linux-gnu/gcc-bin/4.6.0-pre9999/x86_64-pc-linux-gnu-gcc
returned 1 exit status
/usr/lib/gcc/x86_64-pc-linux-gnu/4.6.0-pre9999/../../../../x86_64-pc-linux-gnu/bin/ld:
lto-wrapper failed
collect2: ld returned 1 exit status

Are these flags crazy? Am I a ricer now, using "-O2 -g" ?

Mike, is it your opinion that unless I can fix a bug I should not
report it at all? If so, I do not agree. GCC upstream are of the
impression that GCC 4.6 LTO is ready for production use because they
don't know of failures. In the real world, it can't compile most of
the important packages on my system. The discrepancy, as far as I can
tell, is caused by your policy. Drop on GCC the list of 100 gentoo
packages that don't build with 4.6 trunk + LTO. Let them state in
their documentation that the feature is experimental and is not
expected to work.