Re: GCC cannot find startup files if sysroot=tooldir

[Jonathan Wakely <jwakely dot gcc at gmail dot com>]

On Fri, 18 Jan 2019 at 09:04, Christer Solskogen wrote:
>
> I posted this on the binutils list as well, but the one answer I got
> pointed the finger to gcc.
>
> I've got gcc and binutils compiled with --with-sysroot, but gcc (or
> libgcc in this case) cannot find crti.o, crtn.o and libc in the sysroot
> even if the files are there.
>
> binutils is configured like this:
> /home/builder/binutils-2.31/configure --prefix=/opt/cross
> --target=x86_64-blug-linux-gnu
> --with-sysroot=/opt/cross/x86_64-blug-linux-gnu
>
> gcc is configured like this: /home/builder/gcc-8/configure
> --prefix=/opt/cross --libexecdir=/opt/cross/lib
> --target=x86_64-blug-linux-gnu --enable-languages=c,c++
> --with-sysroot=/opt/cross/x86_64-blug-linux-gnu --disable-multilib
>
> In /opt/cross/x86_64-blug-linux-gnu/usr/lib I've got the files that it
> needs: crt1.o  crti.o  crtn.o  libc.so

Shouldn't that be $sysroot/usr/lib64 for x86_64-*-linux-gnu?

Run this command manually and add -v or -Wl,-v to see where GCC tells
the linker to find them.

>
> But still:
> /tmp/gcc-obj.x86_64-blug-linux-gnu/./gcc/xgcc
> -B/tmp/gcc-obj.x86_64-blug-linux-gnu/./gcc/
> -B/opt/cross/x86_64-blug-linux-gnu/bin/
> -B/opt/cross/x86_64-blug-linux-gnu/lib/ -isystem
> /opt/cross/x86_64-blug-linux-gnu/include -isystem
> /opt/cross/x86_64-blug-linux-gnu/sys-include    -O2  -g -O2 -DIN_GCC
> -DCROSS_DIRECTORY_STRUCTURE  -W -Wall -Wwrite-strings -Wcast-qual
> -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition
> -isystem ./include   -fpic -mlong-double-80 -DUSE_ELF_SYMVER  -g
> -DIN_LIBGCC2 -fbuilding-libgcc -fno-stack-protector  -shared
> -nodefaultlibs -Wl,--soname=libgcc_s.so.1
> -Wl,--version-script=libgcc.map -o ./libgcc_s.so.1.tmp -g -O2 -B./
> _muldi3_s.o _negdi2_s.o _lshrdi3_s.o _ashldi3_s.o _ashrdi3_s.o
> _cmpdi2_s.o _ucmpdi2_s.o _clear_cache_s.o _trampoline_s.o __main_s.o
> _absvsi2_s.o _absvdi2_s.o _addvsi3_s.o _addvdi3_s.o _subvsi3_s.o
> _subvdi3_s.o _mulvsi3_s.o _mulvdi3_s.o _negvsi2_s.o _negvdi2_s.o
> _ctors_s.o _ffssi2_s.o _ffsdi2_s.o _clz_s.o _clzsi2_s.o _clzdi2_s.o
> _ctzsi2_s.o _ctzdi2_s.o _popcount_tab_s.o _popcountsi2_s.o
> _popcountdi2_s.o _paritysi2_s.o _paritydi2_s.o _powisf2_s.o _powidf2_s.o
> _powixf2_s.o _mulhc3_s.o _mulsc3_s.o _muldc3_s.o _mulxc3_s.o _divhc3_s.o
> _divsc3_s.o _divdc3_s.o _divxc3_s.o _bswapsi2_s.o _bswapdi2_s.o
> _clrsbsi2_s.o _clrsbdi2_s.o _fixunssfsi_s.o _fixunsdfsi_s.o
> _fixunsxfsi_s.o _fixsfdi_s.o _fixdfdi_s.o _fixxfdi_s.o _fixunssfdi_s.o
> _fixunsdfdi_s.o _fixunsxfdi_s.o _floatdisf_s.o _floatdidf_s.o
> _floatdixf_s.o _floatundisf_s.o _floatundidf_s.o _floatundixf_s.o
> _divdi3_s.o _moddi3_s.o _divmoddi4_s.o _udivdi3_s.o _umoddi3_s.o
> _udivmoddi4_s.o _udiv_w_sdiv_s.o cpuinfo_s.o sfp-exceptions_s.o
> addtf3_s.o divtf3_s.o multf3_s.o negtf2_s.o subtf3_s.o unordtf2_s.o
> fixtfsi_s.o fixunstfsi_s.o floatsitf_s.o floatunsitf_s.o fixtfdi_s.o
> fixunstfdi_s.o floatditf_s.o floatunditf_s.o fixtfti_s.o fixunstfti_s.o
> floattitf_s.o floatuntitf_s.o extendsftf2_s.o extenddftf2_s.o
> extendxftf2_s.o trunctfsf2_s.o trunctfdf2_s.o trunctfxf2_s.o getf2_s.o
> letf2_s.o eqtf2_s.o _divtc3_s.o _multc3_s.o _powitf2_s.o
> enable-execute-stack_s.o unwind-dw2_s.o unwind-dw2-fde-dip_s.o
> unwind-sjlj_s.o unwind-c_s.o emutls_s.o libgcc.a -lc && rm -f
> ./libgcc_s.so && if [ -f ./libgcc_s.so.1 ]; then mv -f ./libgcc_s.so.1
> ./libgcc_s.so.1.backup; else true; fi && mv ./libgcc_s.so.1.tmp
> ./libgcc_s.so.1 && (echo "/* GNU ld script"; echo "   Use the shared
> library, but some functions are only in"; echo "   the static library.
> */"; echo "GROUP ( libgcc_s.so.1 -lgcc )" ) > ./libgcc_s.so
> /opt/cross/x86_64-blug-linux-gnu/bin/ld: cannot find crti.o: No such
> file or directory
> /opt/cross/x86_64-blug-linux-gnu/bin/ld: cannot find -lc
> /opt/cross/x86_64-blug-linux-gnu/bin/ld: cannot find crtn.o: No such
> file or directory
> collect2: error: ld returned 1 exit status
> make[1]: *** [Makefile:985: libgcc_s.so] Error 1
> make[1]: Leaving directory
> '/tmp/gcc-obj.x86_64-blug-linux-gnu/x86_64-blug-linux-gnu/libgcc'
> make: *** [Makefile:14671: all-target-libgcc] Error 2
>
>
> If I instead configure binutils and gcc to use
> --with-sysroot=/opt/cross/x86_64-blug-linux-gnu/sysroot or
> /opt/cross/x86_64-blug-linux-gnu.sysroot, (and have the startup files in
> there instead) I do not get the error. So it seems like gcc doesn't like
> if sysroot is the same as tooldir.
>
> Is this a bug or intended behavior?

I am not surprised if it doesn't work, since sysroot is for
cross-compilers, and you wouldn't usually want the host toolchain in
the same directory as the headers and libraries for the target,
because host != target.