Missing include “bits/c++config.h” when cross comp

Question

I am running the 32bit version of Ubuntu 10.10 and trying to cross compile to a 64 bit target. Based on my research, I have installed the g++-multilib package.

The program is a very simple hello world:

#include <iostream>

int main( int argc, char** argv )
{
  std::cout << "hello world" << std::endl;
  return 0;
}

Compile:

g++ -m64 main.cpp

Error:

In file included from main.cpp:1:
/usr/include/c++/4.4/iostream:39: fatal error: bits/c++config.h: No such file or directory
compilation terminated.

I have found a c++config.h file but they reside under the i486-linux-gnu and i686-linux-gnu directories in /usr/include/c++/4.4/ There is not c++config.h in /usr/include/c++/bits.

Any ideas on what I am missing? Compiling without the -m64 flag works fine (a.out is created and runs correctly).

Edit Thanks to the hint from @nightcracker, I did a little more investigation into the include structure on the 32 and 64 bit systems. I have added an answer below that "fixes" the problem temporarily but I think it will break on the next update. Basically, I am missing a directory called /usr/include/c++/4.4/i686-linux-gnu/64 that should contain a subdirectory called bits that has the missing include file. Any idea what package should be taking care of this?

Answer 1

Did you try adding -I/usr/include/c++/4.4/i486-linux-gnu or -I/usr/include/c++/4.4/i686-linux-gnu?

Answer 2

This bug is fixed in "gcc-4.6".

https://bugs.launchpad.net/ubuntu/+source/gcc-4.5/+bug/793411

Answer 3

Seems to be a typo error in that package of gcc. The solution:

mv /usr/include/c++/4.x/i486-linux-gnu /usr/include/c++/4.x/i686-linux-gnu/64

Answer 4

While compiling in RHEL 6.2 (x86_64), I installed both 32bit and 64bit libstdc++-dev packages, but I had the "c++config.h no such file or directory" problem.

Resolution:

The directory /usr/include/c++/4.4.6/x86_64-redhat-linux was missing.

I did the following:

cd /usr/include/c++/4.4.6/
mkdir x86_64-redhat-linux
cd x86_64-redhat-linux
ln -s ../i686-redhat-linux 32

I'm now able to compile 32bit binaries on a 64bit OS.

Answer 5

On my 64 bit system I noticed that the following directory existed:

/usr/include/c++/4.4/x86_64-linux-gnu/32/bits

It would then make sense that on my 32 bit system that had been setup for 64bit cross compiling there should be a corresponding directory like:

/usr/include/c++/4.4/i686-linux-gnu/64/bits

I double checked and this directory did not exist. Running g++ with the verbose parameter showed that the compiler was actually looking for something in this location:

jesse@shalored:~/projects/test$ g++ -v -m64 main.cpp 
Using built-in specs.
Target: i686-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.4.4-14ubuntu5' --with-bugurl=file:///usr/share/doc/gcc-4.4/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.4 --enable-shared --enable-multiarch --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.4 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc --enable-targets=all --disable-werror --with-arch-32=i686 --with-tune=generic --enable-checking=release --build=i686-linux-gnu --host=i686-linux-gnu --target=i686-linux-gnu
Thread model: posix
gcc version 4.4.5 (Ubuntu/Linaro 4.4.4-14ubuntu5) 
COLLECT_GCC_OPTIONS='-v' '-m64' '-shared-libgcc' '-mtune=generic'
 /usr/lib/gcc/i686-linux-gnu/4.4.5/cc1plus -quiet -v -imultilib 64 -D_GNU_SOURCE main.cpp -D_FORTIFY_SOURCE=2 -quiet -dumpbase main.cpp -m64 -mtune=generic -auxbase main -version -fstack-protector -o /tmp/ccMvIfFH.s
ignoring nonexistent directory "/usr/include/c++/4.4/i686-linux-gnu/64"
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory "/usr/lib/gcc/i686-linux-gnu/4.4.5/../../../../i686-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/include/c++/4.4
 /usr/include/c++/4.4/backward
 /usr/local/include
 /usr/lib/gcc/i686-linux-gnu/4.4.5/include
 /usr/lib/gcc/i686-linux-gnu/4.4.5/include-fixed
 /usr/include/x86_64-linux-gnu
 /usr/include
End of search list.
GNU C++ (Ubuntu/Linaro 4.4.4-14ubuntu5) version 4.4.5 (i686-linux-gnu)
    compiled by GNU C version 4.4.5, GMP version 4.3.2, MPFR version 3.0.0-p3.
GGC heuristics: --param ggc-min-expand=98 --param ggc-min-heapsize=128197
Compiler executable checksum: 1fe36891f4a5f71e4a498e712867261c
In file included from main.cpp:1:
/usr/include/c++/4.4/iostream:39: fatal error: bits/c++config.h: No such file or directory
compilation terminated.

The error regarding the ignoring nonexistent directory was the clue. Unfortunately, I still don't know what package I need to install to have this directory show up so I just copied the /usr/include/c++/4.4/x86_64-linux-gnu/bits directory from my 64 bit machine to /usr/include/c++/4.4/i686-linux-gnu/64/bits on my 32 machine.

Now compiling with just the -m64 works correctly. The major drawback is that this is still not the correct way to do things and I am guessing the next time Update Manager installs and update to g++ things may break.

Answer 6

Adding this answer partially because it fixed my problem of the same issue and so I can bookmark this question myself.

I was able to fix it by doing the following:

sudo apt-get install gcc-multilib g++-multilib

If you've installed a version of gcc / g++ that doesn't ship by default (such as g++-4.8 on lucid) you'll want to match the version as well:

sudo apt-get install gcc-4.8-multilib g++-4.8-multilib