gcc cross compilation fails

Question

I am trying to build a cross compiling gcc for ARM. This will be to update an existing gcc ARM cross compiler. The build runs fine until it gets to building libstdc++, after libgcc1 builds successfully.

The error is:

<gcc-object-path>/./gcc/xgcc -shared-libgcc -B<gcc-object-path>/./gcc -nostdinc++ -L<gcc-object-path>/<target>/libstdc++-v3/src -L<gcc-object-path>/<target>/libstdc++-v3/src/.libs -L<gcc-object-path>/<target>/libstdc++-v3/libsupc++/.libs -B<sysroot>/<target>/bin/ -B<sysroot>/<target>/lib/ -isystem <sysroot>/<target>/include -isystem <sysroot>/<target>/sys-include --sysroot=<boot-strap-xgcc-sysroot>   -x c++-header -nostdinc++ -g -Os  -I<gcc-object-path>/<target>/libstdc++-v3/include/<target> -I<gcc-object-path>/<target>/libstdc++-v3/include -I<gcc-source-path>/libstdc++-v3/libsupc++ -O2 -g -std=gnu++0x <gcc-source-path>/libstdc++-v3/include/precompiled/stdc++.h \
        -o <target>/bits/stdc++.h.gch/O2ggnu++0x.gch
<gcc-source-path>/libstdc++-v3/include/precompiled/stdc++.h:52:20: fatal error: ccomplex: No such file or directory
 #include <ccomplex>
                    ^
compilation terminated.

find gcc-object-path -name ccomplex -print shows:

<gcc-object-path>/<target>/libstdc++-v3/include/tr1/ccomplex
<gcc-object-path>/<target>/libstdc++-v3/include/ccomplex

The compile command has

-I<gcc-object-path>/<target>/libstdc++-v3/include

on it.

<gcc-object-path>/<target>/libstdc++-v3/include/ccommon

is a symbolic link to

<gcc-source-path>/libstdc++-v3/include/c_std/ccomplex

But that file does not exist in the source at that location, so it is a broken symlink and the compile fails. The file ccomplex does exist in the source tree in three other locations, though. There are 6 other such symlinks that are also similarly broken.

Looking at the libstdc++-v3/include/Makefile that generates these symlinks, it expects to find all of the c_base_headers files in the same location in the source tree, but they are not. How is this supposed to work?

The gcc configure options are:

gcc-${GCC_VERSION}/configure --target=$CONF_TARGET --prefix=${PREFIX} --exec_prefix=${PREFIX} --bindir=${PREFIX}/bin --sbindir=${PREFIX}/bin --libexecdir=${PREFIX}/libexec --datadir=${PREFIX}/share --sysconfdir=${PREFIX}/etc --sharedstatedir=${PREFIX}/share/com --localstatedir=${PREFIX}/var --libdir=${PREFIX}/lib --includedir=${PREFIX}/include --oldincludedir=${PREFIX}/include --infodir=${PREFIX}/share/info --mandir=${PREFIX}/share/man --enable-largefile --disable-nls --enable-ipv6 --with-gnu-ld --enable-shared --enable-languages=c,c++,objc,fortran --enable-threads=posix --disable-multilib --enable-c99 --enable-long-long --enable-symvers-gnu --enable-libstdcxx-pch --program-prefix=${CMD_PREFIX} --enable-target-optspace --enable-cheaders=c_std --disable-bootstrap --disable-libgomp --disable-libmudflap --with-float=soft --with-sysroot=${NEWSYSROOT} --with-build-sysroot=${SYSROOT} --with-build-time-tools=${INSTALLDIR}/${PREFIX}/${CONF_TARGET}/bin --disable-libunwind-exceptions --disable-libssp --enable-__cxa_atexit

Answer 1

What environment are you using? And what is your target environment?

ARM has some toolchains available for download at ARM developer site.

You might need to make available libraries and header files for your target environment. For FreeBSD that would be the appropriate base.txz file which needs to be unpacked in the right place.

For 386 and amd64 FreeBSD v 11.* i there is existing GCC cross compilers for arm. Or to be specific arm64/aarch64. Even with Ada. That is in the ports found in /usr/ports/lang/gnatcross*.

If you google, it should be easy to be able to compile a generic arm cross compiler using a few configure options. Many use arm as an example when compiling the cross compiler.

If you have a Raspberry PI which is either arm or aarch64 architecture, you could have nice native environment. All you then need is to avoid stuff that is operating system dependent.

The RPI have several available operating system including : FreeBSD, Raspbian and other Linuxes and BSD versions.

I'm working at cross compiling GCC for aarch64 FreeBSD 12. It requires some modifications. So I copied the ports involved and modified them. The difficult bit is finding out how to cross compile gcc. And find out which options needs to be disabled.