Re: Support for gcc

["Jose E. Marchesi" <jose.marchesi@oracle.com>]

> On Tue, Dec 20, 2022 at 3:56 AM SuHsueyu <anolasc13@gmail.com> wrote:
>>
>> Hello, I use gcc 12.1.0 to compile a source file:
>> t.c
>> struct t {
>>   int a:2;
>>   int b:3;
>>   int c:2;
>> } g;
>> with gcc -c -gbtf t.c
>> and try to use libbpf API btf__parse_split, bpf_object__open, and
>> bpf_object__open to parse and load into the kernel, but it failed with
>> "libbpf: elf: /path/to/t.o is not a valid eBPF object file".
>
> if (ehdr->e_type != ET_REL || (ehdr->e_machine && ehdr->e_machine != EM_BPF))
>
> This check is failing in libbpf. So check which of those two are not
> set appropriately. cc Jose to point where to report GCC-BPF specific
> issues.

Thanks for the CC.
That would be https://gcc.gnu.org/bugzilla.

(I don't think this is a GCC issue and certainly not a libbpf one.
 Seems like the op is building a x86_64 object and not a BPF object.)

>
>>
>> Is it wrong for me to do so? Due to some constraint, I cannot use
>> clang but gcc. How to parse and load gcc compiled object file with
>> libbpf?