Re: [PATCH bpf-next v2 13/18] selftests/bpf: Test new enum kflag and enum64 API functions

[Yonghong Song <yhs@fb.com>]

On 5/17/22 4:40 PM, Andrii Nakryiko wrote:
> On Fri, May 13, 2022 at 8:13 PM Yonghong Song <yhs@fb.com> wrote:
>>
>> Add tests to use the new enum kflag and enum64 API functions
>> in selftest btf_write.
>>
>> Signed-off-by: Yonghong Song <yhs@fb.com>
>> ---
>>   tools/testing/selftests/bpf/btf_helpers.c     |  21 +++-
>>   .../selftests/bpf/prog_tests/btf_write.c      | 114 +++++++++++++-----
>>   2 files changed, 105 insertions(+), 30 deletions(-)
> 
> [...]
> 
>> @@ -307,6 +308,48 @@ static void gen_btf(struct btf *btf)
>>          ASSERT_EQ(t->type, 1, "tag_type");
>>          ASSERT_STREQ(btf_type_raw_dump(btf, 20),
>>                       "[20] TYPE_TAG 'tag1' type_id=1", "raw_dump");
>> +
>> +       /* ENUM64 */
>> +       id = btf__add_enum64(btf, "e1", 8, true);
>> +       ASSERT_EQ(id, 21, "enum64_id");
>> +       err = btf__add_enum64_value(btf, "v1", -1);
>> +       ASSERT_OK(err, "v1_res");
>> +       err = btf__add_enum64_value(btf, "v2", 0x123456789); /* 4886718345 */
>> +       ASSERT_OK(err, "v2_res");
>> +       t = btf__type_by_id(btf, 21);
>> +       ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "e1", "enum64_name");
>> +       ASSERT_EQ(btf_kind(t), BTF_KIND_ENUM64, "enum64_kind");
>> +       ASSERT_EQ(btf_vlen(t), 2, "enum64_vlen");
>> +       ASSERT_EQ(t->size, 8, "enum64_sz");
>> +       v64 = btf_enum64(t) + 0;
>> +       ASSERT_STREQ(btf__str_by_offset(btf, v64->name_off), "v1", "v1_name");
>> +       ASSERT_EQ(v64->val_hi32, 0xffffffff, "v1_val");
>> +       ASSERT_EQ(v64->val_lo32, 0xffffffff, "v1_val");
>> +       v64 = btf_enum64(t) + 1;
>> +       ASSERT_STREQ(btf__str_by_offset(btf, v64->name_off), "v2", "v2_name");
>> +       ASSERT_EQ(v64->val_hi32, 0x1, "v2_val");
>> +       ASSERT_EQ(v64->val_lo32, 0x23456789, "v2_val");
>> +       ASSERT_STREQ(btf_type_raw_dump(btf, 21),
>> +                    "[21] ENUM64 'e1' size=8 vlen=2\n"
> 
> we should emit and validate kflag for enum/enum64. Or maybe
> "encoding=SIGNED|UNSIGNED" to match INT's output, not sure which one
> is best, but we probably want to make sure that kflag is reflected in
> bpftool and selftests output, right?

My intention is the value print out itself will show it is signed or
unsigned as below. But it doesn't hurt to explicit print out kflag as 
well. Will do.

> 
>> +                    "\t'v1' val=-1\n"
>> +                    "\t'v2' val=4886718345", "raw_dump");
>> +
>> +       id = btf__add_enum64(btf, "e1", 8, false);
>> +       ASSERT_EQ(id, 22, "enum64_id");
>> +       err = btf__add_enum64_value(btf, "v1", 0xffffffffFFFFFFFF); /* 18446744073709551615 */
>> +       ASSERT_OK(err, "v1_res");
>> +       t = btf__type_by_id(btf, 22);
>> +       ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "e1", "enum64_name");
>> +       ASSERT_EQ(btf_kind(t), BTF_KIND_ENUM64, "enum64_kind");
>> +       ASSERT_EQ(btf_vlen(t), 1, "enum64_vlen");
>> +       ASSERT_EQ(t->size, 8, "enum64_sz");
>> +       v64 = btf_enum64(t) + 0;
>> +       ASSERT_STREQ(btf__str_by_offset(btf, v64->name_off), "v1", "v1_name");
>> +       ASSERT_EQ(v64->val_hi32, 0xffffffff, "v1_val");
>> +       ASSERT_EQ(v64->val_lo32, 0xffffffff, "v1_val");
>> +       ASSERT_STREQ(btf_type_raw_dump(btf, 22),
>> +                    "[22] ENUM64 'e1' size=8 vlen=1\n"
>> +                    "\t'v1' val=18446744073709551615", "raw_dump");
>>   }
>>
>>   static void test_btf_add()
> 
> [...]