| Message ID | 20211027230834.2466282-1-yhs@fb.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | BPF |
| Headers | show |
| Series | btf: support typedef DW_TAG_LLVM_annotation | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
| bpf/vmtest-bpf-next-PR | fail | merge-conflict |
| bpf/vmtest-bpf-PR | fail | merge-conflict |
On Wed, Oct 27, 2021 at 4:08 PM Yonghong Song <yhs@fb.com> 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@fb.com> > --- > 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 > + > 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 >
On 11/1/21 7:58 PM, Andrii Nakryiko wrote: > On Wed, Oct 27, 2021 at 4:08 PM Yonghong Song <yhs@fb.com> 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@fb.com> >> --- >> 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 >>
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"; + 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; } }
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@fb.com> --- btf_encoder.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)