Re: Android Native GCC 4.9.2 Build Fails at Dynamic libgcc

[Cyd Haselton <chaselton at gmail dot com>]

On Wed, Jan 7, 2015 at 7:20 AM, Brian Drummond <brian@shapes.demon.co.uk> wrote:
> On Wed, 2015-01-07 at 12:17 +0000, Andrew Haley wrote:
>> On 01/07/2015 12:14 PM, Cyd Haselton wrote:
>> > Here goes.
>>
>> You mailer mangled that.  As an attachment please.
>>
>> Andrew.
>>
>
> Below is the relevant command I saw in the attachment (most .o filenames
> redacted)...
>
> It ends with
> fakechroot: dlopen: undefined symbol: dlopen
> collect2: error: ld returned 1 exit status
> make: *** [libgcc_s.so] Error 1
>
> which I think reinforces your hypothesis that it is the ld program
> itself which fails, rather than anything in the files being linked.
>
> I don't know if Cyd cc'ed you this message...
> (I'll forward it to the list)
> ----------------------------------------------------------------------
>> The following is a quote from the developer who created the
>> environment I'm using:
>>
>>    "Using libfakechroot to virtualize a root filesystem is a bit of a
>> hack, to be honest, and its weaknesses are easily exposed. Most
>> obviously, it will only filter dynamic calls to the Bionic C library
>> (because that was the C library it itself is linked against).
> ...
>> I've been in contact with him regarding a number of other ports and
>> he's confirmed that reverting to static linking would be a pain.
>>
>> Also, iIn case anyone reading this is interested:
>> http://kevinboone.net/kbox2_how_it_works.html
> ----------------------------------------------------------------------
>
> which makes me wonder about Bionic's support for dlopen().

If I understand the android docs correctly, dlopen is supported,
provided the libdl.so library is referenced.  Dlopen isn't *in*
bionic...I don't know if that differs from the standard Linux libc.

>Cyd confirmed
> that he uses the same binutils version for 4.8 and 4.9 so we may be
> looking at a failure in a 2-step process
>
> (a) 4.9 assumes some capability from ld that 4.8 doesn't, which requires
> a DLL to be opened
>
> (b) fakechroot layered over Bionic is failing to implement that
> capability (we know from nm that dlopen is undefined in Cyd's
> libfakechroot.so)
>
> Step (a) may be within the remit of gcc-help, what is the difference and
> can it be worked round) but step (b) probably lies elsewhere : as a
> first step, enquire about the missing dlopen() in fakechroot.
>
I'm not sure if it's missing so much as not included due to the
vagaries of working within the Android environment.  Then again, I
only have a vague idea of how the linking process...both during build
and at runtime...works, and what is required to make it work
successfully.

> -- Brian
>
> Failing command...
> -------------------------------------------------------------------------------------------
>
> /bld/gcc/builddir-4.9/./gcc/xgcc -v -Wl,--verbose
> -B/bld/gcc/builddir-4.9/./gcc/
> -B/usr/gcc-4.9.2/arm-linux-androideabi/bin/
> -B/usr/gcc-4.9.2/arm-linux-androideabi/lib/
> -isystem /usr/gcc-4.9.2/arm-linux-androideabi/include
> -isystem /usr/gcc-4.9.2/arm-linux-androideabi/sys-include
> --sysroot=/usr/gcc-4.9.2/sysroot   -O2  -DIN_GCC    -W -Wall
> -Wno-narrowing -Wwrite-strings -Wcast-qual -Wno-format
> -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition
> -isystem ./include   -fPIC -fno-inline -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 -Wall -O
> -mandroid -mbionic -B./ _thumb1_case_sqi_s.o _thumb1_case_uqi_s.o
> _thumb1_case_shi_s.o _thumb1_case_uhi_s.o _thumb1_case_si_s.o
> _udivsi3_s.o _divsi3_s.o _umodsi3_s.o _modsi3_s.o _bb_init_func_s.o
> _call_via_rX_s.o _interwork_call_via_rX_s.o _lshrdi3_s.o _ashrdi3_s.o
> _ashldi3_s.o _arm_negdf2_s.o _arm_addsubdf3_s.o _arm_muldivdf3_s.o
> _arm_cmpdf2_s.o
> ...
>  divdf3_s.o eqdf2_s.o gedf2_s.o ledf2_s.o muldf3_s.o negdf2_s.o
> subdf3_s.o unorddf2_s.o fixdfsi_s.o floatsidf_s.o floatunsidf_s.o
> extendsfdf2_s.o truncdfsf2_s.o enable-execute-stack_s.o unwind-arm_s.o
> libunwind_s.o pr-support_s.o unwind-c_s.o emutls_s.o libgcc.a -lc -ldl
> && 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 -ldl -lgcc )" )
>> ./libgcc_s.so
> Reading specs from /bld/gcc/builddir-4.9/./gcc/specs
> COLLECT_GCC=/bld/gcc/builddir-4.9/./gcc/xgcc
> COLLECT_LTO_WRAPPER=/bld/gcc/builddir-4.9/./gcc/lto-wrapper
> Target: arm-linux-androideabi
> Configured with: ../gcc-4.9.2/configure --prefix=/usr/gcc-4.9.2
> --build=arm-linux-androideabi --host=arm-linux-androideabi
> --target=arm-linux-androideabi --with-gmp=/usr/gcc-4.9.2
> --with-mpfr=/usr/gcc-4.9.2 --with-mpc=/usr/gcc-4.9.2 --disable-ld
> --with-as=/usr/gcc-4.9.2/bin/as --with-ld=/usr/gcc-4.9.2/bin/ld
> --enable-shared --enable-languages=c,c++ --disable-gold
> --disable-fortran --disable-libssp --disable-libquadmath
> --disable-libquadmath-support --disable-libada --disable-werror
> --disable-multilib --disable-libgomp --disable-cloog
> --with-build-time-tools=/usr/gcc-4.9.2/bin
> --with-build-sysroot=/usr/gcc-4.9.2/sysroot CC='gcc
> --sysroot=/usr/gcc-4.8.3/sysroot' CFLAGS='-Wall -O -mandroid -mbionic'
> LDFLAGS='-Wl,--dynamic-linker=/system/bin/linker -lc -ldl -lgcc -lm
> -lsupc++ -lgnustl_shared' LIBCFLAGS='-O2 -mandroid -mbionic'
> LIBCPPFLAGS='-O2 -mandroid -mbionic' LIBCXXFLAGS='-O2 -mandroid -mbionic
> -fno-implicit-templates' LIBS='-lc -ldl -lgcc -lm -lsupc++
> -lgnustl_shared'
> Thread model: posix
> gcc version 4.9.2 (GCC)
> COMPILER_PATH=/bld/gcc/builddir-4.9/./gcc/:/usr/gcc-4.9.2/arm-linux-androideabi/bin/:/usr/gcc-4.9.2/arm-linux-androideabi/lib/:./
> LIBRARY_PATH=/bld/gcc/builddir-4.9/./gcc/:/usr/gcc-4.9.2/arm-linux-androideabi/bin/:/usr/gcc-4.9.2/arm-linux-androideabi/lib/:./:/usr/gcc-4.9.2/sysroot/usr/lib/
> COLLECT_GCC_OPTIONS='-v' '-B' '/bld/gcc/builddir-4.9/./gcc/' '-B'
> '/usr/gcc-4.9.2/arm-linux-androideabi/bin/' '-B'
> '/usr/gcc-4.9.2/arm-linux-androideabi/lib/' '-isystem'
> '/usr/gcc-4.9.2/arm-linux-androideabi/include' '-isystem'
> '/usr/gcc-4.9.2/arm-linux-androideabi/sys-include' '-O2' '-D' 'IN_GCC'
> '-Wextra' '-Wno-narrowing' '-Wwrite-strings' '-Wcast-qual' '-Wformat=0'
> '-Wstrict-prototypes' '-Wmissing-prototypes' '-Wold-style-definition'
> '-isystem' './include' '-fPIC' '-fno-inline' '-g' '-D' 'IN_LIBGCC2'
> '-fbuilding-libgcc' '-fno-stack-protector' '-shared' '-nodefaultlibs'
> '-o' './libgcc_s.so.1.tmp' '-g' '-O2' '-Wall' '-O' '-mandroid'
> '-mbionic' '-B' './' '-mtls-dialect=gnu'
>  /bld/gcc/builddir-4.9/./gcc/collect2
> -plugin /bld/gcc/builddir-4.9/./gcc/liblto_plugin.so
> -plugin-opt=/bld/gcc/builddir-4.9/./gcc/lto-wrapper
> -plugin-opt=-fresolution=/data/data/jackpal.androidterm/kbox2/tmp/cc757Z3H.res --sysroot=/usr/gcc-4.9.2/sysroot --eh-frame-hdr -shared -dynamic-linker /system/bin/linker -X -m armelf_linux_eabi -Bsymbolic -o ./libgcc_s.so.1.tmp /usr/gcc-4.9.2/sysroot/usr/lib/crtbegin_so.o -L/bld/gcc/builddir-4.9/./gcc -L/usr/gcc-4.9.2/arm-linux-androideabi/bin -L/usr/gcc-4.9.2/arm-linux-androideabi/lib -L. -L/usr/gcc-4.9.2/sysroot/usr/lib --verbose --soname=libgcc_s.so.1 --version-script=libgcc.map _thumb1_case_sqi_s.o _thumb1_case_uqi_s.o _thumb1_case_shi_s.o _thumb1_case_uhi_s.o _thumb1_case_si_s.o _udivsi3_s.o _divsi3_s.o _umodsi3_s.o _modsi3_s.o _bb_init_func_s.o _call_via_rX_s.o _interwork_call_via_rX_s.o _lshrdi3_s.o _ashrdi3_s.o _ashldi3_s.o _arm_negdf2_s.o _arm_addsubdf3_s.o _arm_muldivdf3_s.o _arm_cmpdf2_s.o
> ...
>  divdf3_s.o eqdf2_s.o gedf2_s.o ledf2_s.o muldf3_s.o negdf2_s.o
> subdf3_s.o unorddf2_s.o fixdfsi_s.o floatsidf_s.o floatunsidf_s.o
> extendsfdf2_s.o truncdfsf2_s.o enable-execute-stack_s.o unwind-arm_s.o
> libunwind_s.o pr-support_s.o unwind-c_s.o emutls_s.o libgcc.a -lc
> -ldl /usr/gcc-4.9.2/sysroot/usr/lib/crtend_so.o
> fakechroot: dlopen: undefined symbol: dlopen
> collect2: error: ld returned 1 exit status
> make: *** [libgcc_s.so] Error 1
> -------------------------------------------------------------------------------------------
>