Re: [PATCH bpf-next 10/11] selftests/bpf: add split BTF dedup selftests

[Song Liu <songliubraving@fb.com>]

> On Nov 2, 2020, at 10:05 PM, Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote:
> 
> On Mon, Nov 2, 2020 at 9:35 PM Song Liu <songliubraving@fb.com> wrote:
>> 
>> 
>> 
>>> On Oct 28, 2020, at 5:59 PM, Andrii Nakryiko <andrii@kernel.org> wrote:
>>> 
>>> Add selftests validating BTF deduplication for split BTF case. Add a helper
>>> macro that allows to validate entire BTF with raw BTF dump, not just
>>> type-by-type. This saves tons of code and complexity.
>>> 
>>> Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
>> 
>> Acked-by: Song Liu <songliubraving@fb.com>
>> 
>> with a couple nits:
>> 
>> [...]
>> 
>>> 
>>> int fprintf_btf_type_raw(FILE *out, const struct btf *btf, __u32 id);
>>> const char *btf_type_raw_dump(const struct btf *btf, int type_id);
>>> +int btf_validate_raw(struct btf *btf, int nr_types, const char *exp_types[]);
>>> 
>>> +#define VALIDATE_RAW_BTF(btf, raw_types...)                          \
>>> +     btf_validate_raw(btf,                                           \
>>> +                      sizeof((const char *[]){raw_types})/sizeof(void *),\
>>> +                      (const char *[]){raw_types})
>>> +
>>> +const char *btf_type_c_dump(const struct btf *btf);
>>> #endif
>>> diff --git a/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c b/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c
>>> new file mode 100644
>>> index 000000000000..097370a41b60
>>> --- /dev/null
>>> +++ b/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c
>>> @@ -0,0 +1,326 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +/* Copyright (c) 2020 Facebook */
>>> +#include <test_progs.h>
>>> +#include <bpf/btf.h>
>>> +#include "btf_helpers.h"
>>> +
>>> +
>>> +static void test_split_simple() {
>>> +     const struct btf_type *t;
>>> +     struct btf *btf1, *btf2 = NULL;
>>> +     int str_off, err;
>>> +
>>> +     btf1 = btf__new_empty();
>>> +     if (!ASSERT_OK_PTR(btf1, "empty_main_btf"))
>>> +             return;
>>> +
>>> +     btf__set_pointer_size(btf1, 8); /* enforce 64-bit arch */
>>> +
>>> +     btf__add_int(btf1, "int", 4, BTF_INT_SIGNED);   /* [1] int */
>>> +     btf__add_ptr(btf1, 1);                          /* [2] ptr to int */
>>> +     btf__add_struct(btf1, "s1", 4);                 /* [3] struct s1 { */
>>> +     btf__add_field(btf1, "f1", 1, 0, 0);            /*      int f1; */
>>> +                                                     /* } */
>>> +
>> 
>> nit: two empty lines.
> 
> There is a comment on one of them, so I figured it's not an empty line?

Exactly! I missed that one. 

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