Lto 3.14 fails to build on x86_64

[enriquezmark36]

Hi, I've cloned the branch lto-3.14 from your project and tried to compile with my own .config file (http://pastebin.com/Vj9aqRdV) , but it seems that it couldn't pass an error. Make shows these lines:

lib/lib.a: error adding symbols: Bad value
Makefile:842: recipe for target 'vmlinux' failed
make: *** [vmlinux] Error 1

I don't know what went wrong. On x86, the build finishes successfully in the same computer.
EDIT: It was finished successfully because of a different .config file. Plus, I am on the x86_64 chroot when that happened not on the x86 host. uname -a doesn't tell whether I am on the chroot because I use a 64-bit kernel on a x86 installation. The .config has almost no modules.

All I know that I use
gcc 4.9,
a 64-bit compatible computer
a x86 host (also ubuntu 14.10)
a x86_64 ubuntu 14.10 setup-ed in a chroot,
a "binutils" required that is stated in the documentation,
a bfd linker, and
a MAKEFLAGS variable which is set to "AR=gcc-ar-4.9 NM=gcc-nm-4.9"

I've also saw that a line in config file "CONFIG_LTO_SLIM" was changed from "n" to "y" by Make after I tried to set it to "n". I tried to rebuild with that and it failed with the same error.

[andikleen]

It looks like you're not using gcc-ar or not the correct one?

[enriquezmark36]

What do you mean? Should I recompile gcc from source rather than using the stock gcc from the repositories?

This is the result of gcc-4.9 -v

Using built-in specs.
COLLECT_GCC=gcc-4.9
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.9/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.9.0-3ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-4.9/README.Bugs --enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.9 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.9 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --disable-libmudflap --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.9-amd64/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.9-amd64 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.9-amd64 --with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.9.0 (Ubuntu 4.9.0-3ubuntu1) 

[enriquezmark36]

Hello Andi. I did some tests, lots of them for about four days. I ended up recompiling another binutils based on the configurations set from the binutils Ubuntu have. I get those binutils from the location you said on the documentation.

Then, I have to set MAKEFLAGS to "AR=/usr/bin/gcc-ar NM=/usr/bin/nm RANLIB=/usr/bin/gcc-ranlib" and ran make. Fortunately, it worked. I even tried to add some patches from https://pf.natalenko.name/sources/3.14/ to see whether the build will fail but it didn't.

Bottomline: It is a linker error.

Thanks Andi for the modifications and helping me track down this issue. BTW, will you create a patchset for this branch?