[PATCH v3 dwarves 3/8] btf_encoder: Refactor function addition into dedicated btf_encoder__add_func

[Alan Maguire <alan.maguire@xxxxxxxxxx>]

This will be useful for postponing local function addition later on.
As part of this, store the type id offset and unspecified type in
the encoder, as this will simplify late addition of local functions.

Signed-off-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Andrii Nakryiko <andrii@xxxxxxxxxx>
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: Eduard Zingerman <eddyz87@xxxxxxxxx>
Cc: Hao Luo <haoluo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: John Fastabend <john.fastabend@xxxxxxxxx>
Cc: KP Singh <kpsingh@xxxxxxxxxxxx>
Cc: Kui-Feng Lee <sinquersw@xxxxxxxxx>
Cc: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
Cc: Song Liu <songliubraving@xxxxxx>
Cc: Stanislav Fomichev <sdf@xxxxxxxxxx>
Cc: Timo Beckers <timo@xxxxxxxxxx>
Cc: Yonghong Song <yhs@xxxxxx>
Cc: bpf@xxxxxxxxxxxxxxx
---
 btf_encoder.c | 46 +++++++++++++++++++++++++++-------------------
 1 file changed, 27 insertions(+), 19 deletions(-)

diff --git a/btf_encoder.c b/btf_encoder.c
index 9063342..71f67ae 100644
--- a/btf_encoder.c
+++ b/btf_encoder.c
@@ -764,6 +764,31 @@ static int32_t btf_encoder__add_decl_tag(struct btf_encoder *encoder, const char
 	return id;
 }
 
+static int32_t btf_encoder__add_func(struct btf_encoder *encoder, struct function *fn)
+{
+	int btf_fnproto_id, btf_fn_id, tag_type_id;
+	struct llvm_annotation *annot;
+	const char *name;
+
+	btf_fnproto_id = btf_encoder__add_func_proto(encoder, &fn->proto);
+	name = function__name(fn);
+	btf_fn_id = btf_encoder__add_ref_type(encoder, BTF_KIND_FUNC, btf_fnproto_id, name, false);
+	if (btf_fnproto_id < 0 || btf_fn_id < 0) {
+		printf("error: failed to encode function '%s'\n", function__name(fn));
+		return -1;
+	}
+	list_for_each_entry(annot, &fn->annots, node) {
+		tag_type_id = btf_encoder__add_decl_tag(encoder, annot->value, btf_fn_id,
+							annot->component_idx);
+		if (tag_type_id < 0) {
+			fprintf(stderr, "error: failed to encode tag '%s' to func %s with component_idx %d\n",
+				annot->value, name, annot->component_idx);
+			return -1;
+		}
+	}
+	return 0;
+}
+
 /*
  * This corresponds to the same macro defined in
  * include/linux/kallsyms.h
@@ -1589,8 +1614,6 @@ int btf_encoder__encode_cu(struct btf_encoder *encoder, struct cu *cu, struct co
 	}
 
 	cu__for_each_function(cu, core_id, fn) {
-		int btf_fnproto_id, btf_fn_id;
-		const char *name;
 
 		/*
 		 * Skip functions that:
@@ -1620,24 +1643,9 @@ int btf_encoder__encode_cu(struct btf_encoder *encoder, struct cu *cu, struct co
 				continue;
 		}
 
-		btf_fnproto_id = btf_encoder__add_func_proto(encoder, &fn->proto);
-		name = function__name(fn);
-		btf_fn_id = btf_encoder__add_ref_type(encoder, BTF_KIND_FUNC, btf_fnproto_id, name, false);
-		if (btf_fnproto_id < 0 || btf_fn_id < 0) {
-			err = -1;
-			printf("error: failed to encode function '%s'\n", function__name(fn));
+		err = btf_encoder__add_func(encoder, fn);
+		if (err)
 			goto out;
-		}
-
-		list_for_each_entry(annot, &fn->annots, node) {
-			tag_type_id = btf_encoder__add_decl_tag(encoder, annot->value, btf_fn_id, annot->component_idx);
-			if (tag_type_id < 0) {
-				fprintf(stderr, "error: failed to encode tag '%s' to func %s with component_idx %d\n",
-					annot->value, name, annot->component_idx);
-				goto out;
-			}
-		}
-
 	}
 
 	if (!encoder->skip_encoding_vars)
-- 
2.31.1