Errors while trying to build GDB for ARM

I'm trying to build GDB (version 8.0) for an arm on my Ubuntu 16.04 machine. I'm planning to debug it directly on the arm machine (currently without a server).

I have executed these instructions (as it was explained here)

./configure --target=arm-linux-gnueabi --host=arm-linux-gnueabi --build=x86_64_unknown-linux-gnu 
make

During the linkage the system threw me this error:

g++ -std=gnu++11 -g -O2   -static-libstdc++ -static-libgcc    \
    -o gdb gdb.o arm.o arm-linux.o arm-get-next-pcs.o arm-tdep.o arm-linux-tdep.o glibc-tdep.o solib-svr4.o symfile-mem.o linux-tdep.o linux-record.o ser-base.o ser-unix.o ser-pipe.o ser-tcp.o inf-ptrace.o fork-child.o arm-linux-nat.o aarch32-linux-nat.o proc-service.o linux-thread-db.o linux-nat.o linux-osdata.o linux-fork.o linux-procfs.o linux-ptrace.o linux-waitpid.o linux-personality.o linux-namespaces.o ax-gdb.o ax-general.o ctf.o dcache.o remote.o remote-fileio.o remote-notif.o tracefile.o tracefile-tfile.o tracepoint.o  cli-cmds.o cli-decode.o cli-dump.o cli-interp.o cli-logging.o cli-script.o cli-setshow.o cli-utils.o mi-cmd-break.o mi-cmd-catch.o mi-cmd-disas.o mi-cmd-env.o mi-cmd-file.o mi-cmd-info.o mi-cmd-stack.o mi-cmd-target.o mi-cmd-var.o mi-cmds.o mi-console.o mi-getopt.o mi-interp.o mi-main.o mi-out.o mi-parse.o mi-symbol-cmds.o stub-termcap.o python.o guile.o elfread.o stap-probe.o dtrace-probe.o posix-hdep.o posix-strerror.o ada-exp.o c-exp.o cp-name-parser.o d-exp.o f-exp.o go-exp.o m2-exp.o p-exp.o rust-exp.o ada-lang.o ada-tasks.o ada-typeprint.o ada-valprint.o ada-varobj.o addrmap.o agent.o annotate.o arch-utils.o auto-load.o auxv.o bcache.o bfd-target.o block.o blockframe.o break-catch-sig.o break-catch-syscall.o break-catch-throw.o breakpoint.o btrace.o btrace-common.o buffer.o build-id.o buildsym.o c-lang.o c-typeprint.o c-valprint.o c-varobj.o charset.o cleanups.o cli-out.o coff-pe-read.o coffread.o common-agent.o common-debug.o common-exceptions.o common-regcache.o common-utils.o complaints.o completer.o continuations.o copying.o corefile.o corelow.o cp-abi.o cp-namespace.o cp-support.o cp-valprint.o d-lang.o d-namespace.o d-valprint.o dbxread.o debug.o demangle.o dfp.o dictionary.o disasm.o disasm-selftests.o doublest.o dummy-frame.o dwarf2-frame.o dwarf2-frame-tailcall.o dwarf2expr.o dwarf2loc.o dwarf2read.o environ.o errors.o eval.o event-loop.o event-top.o exceptions.o exec.o expprint.o extension.o f-lang.o f-typeprint.o f-valprint.o fileio.o filestuff.o filesystem.o findcmd.o findvar.o format.o frame.o frame-base.o frame-unwind.o gcore.o gdb_bfd.o gdb-dlfcn.o gdb_obstack.o gdb_usleep.o gdb_vecs.o gdbarch.o gdbtypes.o gnu-v2-abi.o gnu-v3-abi.o go-lang.o go-typeprint.o go-valprint.o inf-child.o inf-loop.o infcall.o infcmd.o inferior.o infrun.o inline-frame.o interps.o jit.o language.o linespec.o location.o m2-lang.o m2-typeprint.o m2-valprint.o macrocmd.o macroexp.o macroscope.o macrotab.o main.o maint.o mdebugread.o mem-break.o memattr.o memory-map.o memrange.o mi-common.o minidebug.o minsyms.o mipsread.o namespace.o new-op.o objc-lang.o objfiles.o observer.o opencl-lang.o osabi.o osdata.o p-lang.o p-typeprint.o p-valprint.o parse.o print-utils.o printcmd.o probe.o progspace.o prologue-value.o psymtab.o ptid.o record.o record-btrace.o record-full.o regcache.o reggroups.o registry.o reverse.o rsp-low.o run-time-clock.o rust-lang.o selftest.o selftest-arch.o sentinel-frame.o ser-event.o serial.o signals.o signals-state-save-restore.o skip.o solib.o solib-target.o source.o stabsread.o stack.o std-regs.o symfile.o symfile-debug.o symmisc.o symtab.o target.o target-dcache.o target-descriptions.o target-memory.o thread.o thread-fsm.o tid-parse.o top.o trad-frame.o tramp-frame.o typeprint.o ui-file.o ui-out.o user-regs.o utils.o utils-selftests.o valarith.o valops.o valprint.o value.o varobj.o vec.o version.o waitstatus.o xml-builtin.o xml-support.o xml-syscall.o xml-tdesc.o xml-utils.o compile.o compile-c-support.o compile-c-symbols.o compile-c-types.o compile-loc2c.o compile-object-load.o compile-object-run.o inflow.o    init.o \
       ../readline/libreadline.a ../opcodes/libopcodes.a ../bfd/libbfd.a -L./../zlib -lz  ../libiberty/libiberty.a ../libdecnumber/libdecnumber.a    -ldl -ldl -lm -ldl     ../libiberty/libiberty.a  build-gnulib/import/libgnu.a  -ldl -Wl,--dynamic-list=./proc-service.list
/usr/bin/ld: ../readline/libreadline.a(readline.o): Relocations in generic ELF (EM: 40)
/usr/bin/ld: ../readline/libreadline.a(readline.o): Relocations in generic ELF (EM: 40)
/usr/bin/ld: ../readline/libreadline.a(readline.o): Relocations in generic ELF (EM: 40)
/usr/bin/ld: ../readline/libreadline.a(readline.o): Relocations in generic ELF (EM: 40)
/usr/bin/ld: ../readline/libreadline.a(readline.o): Relocations in generic ELF (EM: 40)
/usr/bin/ld: ../readline/libreadline.a(readline.o): Relocations in generic ELF (EM: 40)
/usr/bin/ld: ../readline/libreadline.a(readline.o): Relocations in generic ELF (EM: 40)
../readline/libreadline.a: error adding symbols: File in wrong format
collect2: error: ld returned 1 exit status
Makefile:2215: recipe for target 'gdb' failed
make[2]: *** [gdb] Error 1
make[2]: Leaving directory '/home/user/gdb-8.0/gdb'
Makefile:9126: recipe for target 'all-gdb' failed
make[1]: *** [all-gdb] Error 2
make[1]: Leaving directory '/home/user/gdb-8.0'
Makefile:849: recipe for target 'all' failed
make: *** [all] Error 2

I have tried to download a new readline library and replace it with the one that comes with the gdb, but it didn't solve my problem.

Does anybody have a clue?

Thanks!

回答1:

Your command looks correct. The reason it doesn't work as expected must be that your ARM cross-compilation toolchain is not available in your $PATH or its prefix is not arm-linux-gnueabi.

As an example suppose that you downloaded gcc-linaro-7.2.1-2017.11-x86_64_arm-linux-gnueabi.tar.xz toolchain and unpacked it under ~/tmp. The following commands should build gdb successfully:

PATH="$PATH:$HOME/tmp/gcc-linaro-7.2.1-2017.11-x86_64_arm-linux-gnueabi/bin"
./configure --host=arm-linux-gnueabi
make

I shortened ./configure invocation because defaults suffice (TARGET=HOST and BUILD=<automatically guessed>).

The confusion here comes from the fact that --host=... makes configure script look for arm-linux-gnueabi-gcc (...-ld, etc.), but in case it can't find them gcc, ld are used assuming that they cross-compile to HOST. This fallback behaviour is what happened here.

To make sure that correct toolchain is used, watch for

checking for arm-linux-gnueabi-gcc...  found arm-linux-gnueabi-gcc

line in the output of configure.

Do not specify LD=arm-XXX-ld CC=arm-XXX-gcc CXX=arm-XXX-g++ as others have suggested, the point of --host= option is to find these things for you, you just need to put them in your $PATH.

回答2:

./configure --target=arm-linux-gnueabi ...

You are trying to build an ARM binary on an x86 machine. You need a cross-compiler targeting ARM for that, but you appear to be using your native compiler (which produces x86 objects).

As fei han said, you need:

./configure ... LD=/path/to/arm-XXX-ld CC=/path/to/arm-XXX-gcc CXX=/path/to/arm-XXX-g++