selftests/bpf: add fwd enum resolution test for btf_dedup

This patch adds test verifying new btf_dedup logic of resolving
forward-declared enums.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 44 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c
index 38797aa627a7..23e3b314ca60 100644
--- a/tools/testing/selftests/bpf/test_btf.c
+++ b/tools/testing/selftests/bpf/test_btf.c
@@ -5874,6 +5874,50 @@ const struct btf_dedup_test dedup_tests[] = {
                 .dont_resolve_fwds = false,
         },
 },
+{
+        .descr = "dedup: enum fwd resolution",
+        .input = {
+                .raw_types = {
+                        /* [1] fwd enum 'e1' before full enum */
+                        BTF_TYPE_ENC(NAME_NTH(1), BTF_INFO_ENC(BTF_KIND_ENUM, 0, 0), 4),
+                        /* [2] full enum 'e1' after fwd */
+                        BTF_TYPE_ENC(NAME_NTH(1), BTF_INFO_ENC(BTF_KIND_ENUM, 0, 1), 4),
+                                BTF_ENUM_ENC(NAME_NTH(2), 123),
+                        /* [3] full enum 'e2' before fwd */
+                        BTF_TYPE_ENC(NAME_NTH(3), BTF_INFO_ENC(BTF_KIND_ENUM, 0, 1), 4),
+                                BTF_ENUM_ENC(NAME_NTH(4), 456),
+                        /* [4] fwd enum 'e2' after full enum */
+                        BTF_TYPE_ENC(NAME_NTH(3), BTF_INFO_ENC(BTF_KIND_ENUM, 0, 0), 4),
+                        /* [5] incompatible fwd enum with different size */
+                        BTF_TYPE_ENC(NAME_NTH(1), BTF_INFO_ENC(BTF_KIND_ENUM, 0, 0), 1),
+                        /* [6] incompatible full enum with different value */
+                        BTF_TYPE_ENC(NAME_NTH(1), BTF_INFO_ENC(BTF_KIND_ENUM, 0, 1), 4),
+                                BTF_ENUM_ENC(NAME_NTH(2), 321),
+                        BTF_END_RAW,
+                },
+                BTF_STR_SEC("\0e1\0e1_val\0e2\0e2_val"),
+        },
+        .expect = {
+                .raw_types = {
+                        /* [1] full enum 'e1' */
+                        BTF_TYPE_ENC(NAME_NTH(1), BTF_INFO_ENC(BTF_KIND_ENUM, 0, 1), 4),
+                                BTF_ENUM_ENC(NAME_NTH(2), 123),
+                        /* [2] full enum 'e2' */
+                        BTF_TYPE_ENC(NAME_NTH(3), BTF_INFO_ENC(BTF_KIND_ENUM, 0, 1), 4),
+                                BTF_ENUM_ENC(NAME_NTH(4), 456),
+                        /* [3] incompatible fwd enum with different size */
+                        BTF_TYPE_ENC(NAME_NTH(1), BTF_INFO_ENC(BTF_KIND_ENUM, 0, 0), 1),
+                        /* [4] incompatible full enum with different value */
+                        BTF_TYPE_ENC(NAME_NTH(1), BTF_INFO_ENC(BTF_KIND_ENUM, 0, 1), 4),
+                                BTF_ENUM_ENC(NAME_NTH(2), 321),
+                        BTF_END_RAW,
+                },
+                BTF_STR_SEC("\0e1\0e1_val\0e2\0e2_val"),
+        },
+        .opts = {
+                .dont_resolve_fwds = false,
+        },
+},
 
 };