Errors while trying to build GDB for ARM - linux

Question

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!

Answer 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.

Answer 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++