On 11/1/21 7:58 PM, Andrii Nakryiko wrote:
On Wed, Oct 27, 2021 at 4:08 PM Yonghong Song <yhs@xxxxxx> wrote:Emit BTF BTF_KIND_DECL_TAGs for btf_decl_tag attributes attached to typedef declarations. The following is a simple example: $ cat t.c #define __tag1 __attribute__((btf_decl_tag("tag1"))) #define __tag2 __attribute__((btf_decl_tag("tag2"))) typedef struct { int a; int b; } __t __tag1 __tag2; __t g; $ clang -O2 -g -c t.c $ pahole -JV t.o btf_encoder__new: 't.o' doesn't have '.data..percpu' section Found 0 per-CPU variables! File t.o: [1] TYPEDEF __t type_id=2 [2] STRUCT (anon) size=8 a type_id=3 bits_offset=0 b type_id=3 bits_offset=32 [3] INT int size=4 nr_bits=32 encoding=SIGNED [4] DECL_TAG tag1 type_id=1 component_idx=-1 [5] DECL_TAG tag2 type_id=1 component_idx=-1 Signed-off-by: Yonghong Song <yhs@xxxxxx> --- btf_encoder.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/btf_encoder.c b/btf_encoder.c index 40f6aa3..2f1f4ae 100644 --- a/btf_encoder.c +++ b/btf_encoder.c @@ -1437,19 +1437,25 @@ int btf_encoder__encode_cu(struct btf_encoder *encoder, struct cu *cu) } cu__for_each_type(cu, core_id, pos) { + const char *tag_name = "typedef"; struct namespace *ns; - if (pos->tag != DW_TAG_structure_type && pos->tag != DW_TAG_union_type) + if (pos->tag != DW_TAG_structure_type && pos->tag != DW_TAG_union_type && + pos->tag != DW_TAG_typedef) continue; + if (pos->tag == DW_TAG_structure_type) + tag_name = "struct"; + else if (pos->tag == DW_TAG_union_type) + tag_name = "union";nit: switch instead of these two related sets of if/else blocks would be cleaner
Sure. Will make the change in v2.
+ btf_type_id = type_id_off + core_id; ns = tag__namespace(pos); list_for_each_entry(annot, &ns->annots, node) { tag_type_id = btf_encoder__add_decl_tag(encoder, annot->value, btf_type_id, annot->component_idx); if (tag_type_id < 0) { fprintf(stderr, "error: failed to encode tag '%s' to %s '%s' with component_idx %d\n", - annot->value, pos->tag == DW_TAG_structure_type ? "struct" : "union", - namespace__name(ns), annot->component_idx); + annot->value, tag_name, namespace__name(ns), annot->component_idx); goto out; } } -- 2.30.2
