Re: [PATCH bpf-next 2/6] libbpf: Collect static vs global info about functions

On Wed, Jan 08, 2020 at 05:57:55PM +0000, Song Liu wrote:

quoted

On Jan 8, 2020, at 2:25 AM, Toke Høiland-Jørgensen [off-list ref] wrote:

Alexei Starovoitov [off-list ref] writes:

quoted

Collect static vs global information about BPF functions from ELF file and
improve BTF with this additional info if llvm is too old and doesn't emit it on
its own.

Has the support for this actually landed in LLVM yet? I tried grep'ing
in the commit log and couldn't find anything...

[...]

quoted

@@ -313,6 +321,7 @@ struct bpf_object {

	bool loaded;
	bool has_pseudo_calls;
	bool relaxed_core_relocs;
+	bool llvm_emits_func_linkage;

Nit: s/llvm/compiler/? Presumably GCC will also support this at some
point?

Echoing this nit (and other references to llvm). Otherwise,

sure. will rename to compiler, but I think you folks are overly optimistic
about gcc. Even basic stuff doesn't work yet. I doubt we will see BTF
emitted by gcc this year.