> > ============ Vanilla ==========
> > struct foo {
> > struct {
> > int aa;
> > char ab;
> > } a;
> > long :64;
> > int :4;
> > char b;
> > short c;
> > };
> > offsetof(struct foo, c)=18
> >
> > ============ Custom ==========
> > struct foo {
> > long: 8;
> > long: 64;
> > long: 64;
> > char b;
> > short c;
> > };
>
> so I guess the issue is that the first 'long: 8' is padded to full
> long: 64 ?
>
> looks like btf_dump_emit_bit_padding did not take into accout the gap
> on the
> begining of the struct
>
> on the other hand you generated that header file from 'min_core_btf'
> btf data,
> which takes away all the unused fields.. it might not beeen
> considered as a
> use case before
>
> jirka
>
> That could be the case, but I think the 'emit_bit_padding()' will not
> really have a
> lot to do for the non sparse headers ..
> /Per
Looks like something like this makes tings a lot better:
diff --git a/src/btf_dump.c b/src/btf_dump.c
index 12f7039..a8bd52a 100644
--- a/src/btf_dump.c
+++ b/src/btf_dump.c
@@ -881,13 +881,13 @@ static void btf_dump_emit_bit_padding(const
struct btf_dump *d,
const char *pad_type;
int pad_bits;
- if (ptr_bits > 32 && off_diff > 32) {
+ if (align > 4 && ptr_bits > 32 && off_diff > 32) {
pad_type = "long";
pad_bits = chip_away_bits(off_diff, ptr_bits);
- } else if (off_diff > 16) {
+ } else if (align > 2 && off_diff > 16) {
pad_type = "int";
pad_bits = chip_away_bits(off_diff, 32);
- } else if (off_diff > 8) {
+ } else if (align > 1 && off_diff > 8) {
pad_type = "short";
pad_bits = chip_away_bits(off_diff, 16);
} else {
/Per
