Question

I am new to Linux programming and am attempting to use the BFD library. This is the current code I’m trying to compile:

#include <bfd.h>
#include <stdlib.h>

bfd *abfd;

int main() {
  bfd_init();
  abfd = bfd_openr("/home/mike/Desktop/testFunc/testProg", NULL);
  return 0;
}

I am using the following command line for compiling:

gcc readInfo.c /usr/lib/libbfd.a -o readInfo

And am getting the following errors:

gcc readInfo.c /usr/lib/libbfd.a -o readInfo
/usr/lib/libbfd.a(elflink.o): In function
elf_link_add_object_symbols':
/build/buildd/binutils-2.21.53.20110810/builddir-single/bfd/../../bfd/elflink.c:4605:
undefined reference toobjalloc_free_block’
/build/buildd/binutils-2.21.53.20110810/builddir-single/bfd/../../bfd/elflink.c:4892:
undefined reference to _sch_istable' /usr/lib/libbfd.a(elflink.o): In
functionbfd_elf_size_dynamic_sections’:
/build/buildd/binutils-2.21.53.20110810/builddir-single/bfd/../../bfd/elflink.c:6048:
undefined reference to lbasename'
undefined reference to_sch_istable’ collect2: ld returned 1 exit
status make: * [all] Error 1

There are a lot more lines of errors, which you can view here. I’m sure there is a simple explanation for this but it has got me stumped for a while.

To summarise what I have done so far:

• Installed clean build of Ubuntu
• Installed binutils-dev package

Answer 1

Do you need to statically link your program?

It compiles and runs without error if you dynamically link it instead:

gcc readInfo.c -o readInfo -lbfd

I’ve run into a new problem when trying to make it statically linked:

$ gcc readInfo.c /usr/lib/libbfd.a /usr/lib/x86_64-linux-gnu/libc.a -o readInfo
/usr/bin/ld.bfd.real: dynamic STT_GNU_IFUNC symbol `strcmp' with pointer equality
    in `/usr/lib/x86_64-linux-gnu/libc.a(strcmp.o)' can not be used when making
    an executable; recompile with -fPIE and relink with -pie
collect2: ld returned 1 exit status
$ gcc -fPIE readInfo.c /usr/lib/libbfd.a /usr/lib/x86_64-linux-gnu/libc.a \
    -o readInfo
/usr/bin/ld.bfd.real: dynamic STT_GNU_IFUNC symbol `strcmp' with pointer equality
    in `/usr/lib/x86_64-linux-gnu/libc.a(strcmp.o)' can not be used when making
    an executable; recompile with -fPIE and relink with -pie
collect2: ld returned 1 exit status
$ gcc -fPIE -pie readInfo.c /usr/lib/libbfd.a /usr/lib/x86_64-linux-gnu/libc.a \
  -o readInfo
/usr/bin/ld.bfd.real: /usr/lib/libbfd.a(opncls.o): relocation R_X86_64_32S
    against `.rodata' can not be used when making a shared object; recompile with
    -fPIC
/usr/lib/libbfd.a: could not read symbols: Bad value
collect2: ld returned 1 exit status
$ gcc -fPIC -fPIE -pie readInfo.c /usr/lib/libbfd.a \
  /usr/lib/x86_64-linux-gnu/libc.a -o readInfo
/usr/bin/ld.bfd.real: /usr/lib/libbfd.a(opncls.o): relocation R_X86_64_32S
    against `.rodata' can not be used when making a shared object; recompile with
    -fPIC
/usr/lib/libbfd.a: could not read symbols: Bad value
collect2: ld returned 1 exit status