Why does clang still need libgcc.a to compile my code? : <pre><code>int main(int argc, char **argv)
{
    return 0;
}
</code></pre>

<p>I cross compile (host= linux x86_64, target= linux aarch64)</p>

<p><code>/path/to/clang --target=aarch64-linux-gnu -v main.cpp -o main -fuse-ld=lld  -L./libs -lc -lc_nonshared -Xlinker -Map=a.map</code></p>

<p>In the -L./libs folder I've put all the dependencies from the target. When I exclude libgcc.a this linker error happens</p>

<p><code>ld.lld: error: unable to find library -lgcc</code></p>

<p>I've added the -Map option to get information about the linked static libraries. In the map file I cannot see references to libgcc.a ... but I battle to read the map file. There are plenty of lines with <code>&lt;internal&gt;</code>. Not sure what those are.  See a.map at the bottom</p>

<p><strong>Questions</strong></p>

<ol>
<li>Why is libgcc.a still required for such a simple program? I read <a href="https://gcc.gnu.org/onlinedocs/gccint/Libgcc.html" rel="noreferrer">1</a> and <a href="https://stackoverflow.com/questions/9414625/do-i-really-need-libgcc">2</a> and I looked at <a href="https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other-Builtins" rel="noreferrer">3</a>.</li>
<li>Does 

<ul>
<li>(a) the linker require libgcc to do its own linking work, or </li>
<li>(b) does the linker use libgcc because my code requires something that is provided for by libgcc</li>
<li>I think it's (b), but I just want to be sure.</li>
</ul></li>
</ol>

<hr>

<p>a.map</p>

<pre><code>     VMA              LMA     Size Align Out     In      Symbol
   10270            10270       1b     1 .interp
   10270            10270       1b     1         &lt;internal&gt;:(.interp)
   10290            10290       a8     8 .dynsym
   10290            10290       a8     8         &lt;internal&gt;:(.dynsym)
   10338            10338        e     2 .gnu.version
   10338            10338        e     2         &lt;internal&gt;:(.gnu.version)
   10348            10348       20     4 .gnu.version_r
   10348            10348       20     4         &lt;internal&gt;:(.gnu.version_r)
   10368            10368       1c     8 .gnu.hash
   10368            10368       1c     8         &lt;internal&gt;:(.gnu.hash)
   10384            10384       87     1 .dynstr
   10384            10384       87     1         &lt;internal&gt;:(.dynstr)
   10410            10410       18     8 .rela.dyn
   10410            10410       18     8         &lt;internal&gt;:(.rela.dyn)
   10428            10428       48     8 .rela.plt
   10428            10428       48     8         &lt;internal&gt;:(.rela.plt)
   10470            10470       20     4 .note.ABI-tag
   10470            10470       20     4         crt1.o:(.note.ABI-tag)
   10470            10470        0     1                 $d
   10490            10490        4     4 .rodata
   10490            10490        4     4         &lt;internal&gt;:(.rodata)
   10494            10494        c     4 .eh_frame_hdr
   10494            10494        c     4         &lt;internal&gt;:(.eh_frame_hdr)
   104a0            104a0        4     4 .eh_frame
   20000            20000      210     8 .text
   20000            20000       48     8         crt1.o:(.text)
   20000            20000        0     1                 $x
   20000            20000        0     1                 _start
   2002c            2002c        0     1                 $d
   20048            20048       14     4         crti.o:(.text)
   20048            20048        0     1                 $x
   20048            20048       14     1                 call_weak_fn
   20060            20060       e0     8         crtbegin.o:(.text)
   20060            20060        0     1                 $x
   20060            20060        0     1                 deregister_tm_clones
   20090            20090        0     1                 $d
   20098            20098        0     1                 $x
   20098            20098        0     1                 register_tm_clones
   200d0            200d0        0     1                 $d
   200d8            200d8        0     1                 $x
   200d8            200d8        0     1                 __do_global_dtors_aux
   20108            20108        0     1                 frame_dummy
   20138            20138        0     1                 $d
   20140            20140       54     4         /tmp/main-762849.o:(.text)
   20140            20140        0     1                 $x.0
   20140            20140       10     1                 do_math(int*)
   20150            20150       44     1                 main
   20194            20194       7c     4         ./libs/libc_nonshared.a(elf-init.oS):(.text)
   20194            20194        0     1                 $x
   20194            20194       78     1                 __libc_csu_init
   2020c            2020c        4     1                 __libc_csu_fini
   20210            20210        0     1         crtend.o:(.text)
   20210            20210        0     1         crtn.o:(.text)
   20210            20210       14     4 .init
   20210            20210        c     4         crti.o:(.init)
   20210            20210        0     1                 $x
   20210            20210        0     1                 _init
   2021c            2021c        8     1         crtn.o:(.init)
   2021c            2021c        0     1                 $x
   20224            20224       10     4 .fini
   20224            20224        8     4         crti.o:(.fini)
   20224            20224        0     1                 $x
   20224            20224        0     1                 _fini
   2022c            2022c        8     1         crtn.o:(.fini)
   2022c            2022c        0     1                 $x
   20240            20240       50    16 .plt
   20240            20240       50    16         &lt;internal&gt;:(.plt)
   30000            30000       10     8 .data
   30000            30000        4     1         crt1.o:(.data)
   30000            30000        0     1                 data_start
   30000            30000        0     1                 __data_start
   30004            30004        0     1         crti.o:(.data)
   30008            30008        8     8         crtbegin.o:(.data)
   30008            30008        0     1                 $d
   30008            30008        0     1                 __dso_handle
   30010            30010        0     1         ./libs/libc_nonshared.a(elf-init.oS):(.data)
   30010            30010        0     1         crtend.o:(.data)
   30010            30010        0     1         crtn.o:(.data)
   30010            30010        0     8 .tm_clone_table
   30010            30010        0     8         crtbegin.o:(.tm_clone_table)
   30010            30010        0     1                 __TMC_LIST__
   30010            30010        0     8         crtend.o:(.tm_clone_table)
   30010            30010        0     1                 __TMC_END__
   30010            30010       30     8 .got.plt
   30010            30010       30     8         &lt;internal&gt;:(.got.plt)
   40000            40000        8     8 .jcr
   40000            40000        0     8         crtbegin.o:(.jcr)
   40000            40000        0     1                 __JCR_LIST__
   40000            40000        8     8         crtend.o:(.jcr)
   40000            40000        0     1                 $d
   40000            40000        0     1                 __JCR_END__
   40008            40008        8     8 .fini_array
   40008            40008        8     8         crtbegin.o:(.fini_array)
   40008            40008        0     1                 $d
   40008            40008        0     1                 __do_global_dtors_aux_fini_array_entry
   40010            40010        8     8 .init_array
   40010            40010        8     8         crtbegin.o:(.init_array)
   40010            40010        0     1                 $d
   40010            40010        0     1                 __frame_dummy_init_array_entry
   40018            40018      180     8 .dynamic
   40018            40018      180     8         &lt;internal&gt;:(.dynamic)
   40198            40198        8     8 .got
   40198            40198        8     8         &lt;internal&gt;:(.got)
   50000            50000        1     1 .bss
   50000            50000        0     1         crt1.o:(.bss)
   50000            50000        0     1         crti.o:(.bss)
   50000            50000        1     1         crtbegin.o:(.bss)
   50000            50000        1     1                 completed.7557
   50000            50000        0     1                 $d
   50001            50001        0     1         ./libs/libc_nonshared.a(elf-init.oS):(.bss)
   50001            50001        0     1         crtend.o:(.bss)
   50001            50001        0     1         crtn.o:(.bss)
       0                0       24     1 .gnu_debuglink
       0                0        c     1         crt1.o:(.gnu_debuglink)
       c                c        c     1         crti.o:(.gnu_debuglink)
      18               18        c     1         crtn.o:(.gnu_debuglink)
       0                0       9d     1 .comment
       0                0       9d     1         &lt;internal&gt;:(.comment)
       0                0      5b8     8 .symtab
       0                0      5b8     8         &lt;internal&gt;:(.symtab)
       0                0      119     1 .shstrtab
       0                0      119     1         &lt;internal&gt;:(.shstrtab)
       0                0      228     1 .strtab
       0                0      228     1         &lt;internal&gt;:(.strtab)
</code></pre>
