@@ -129,6 +129,109 @@ static int test_btf_dump_case(int n, struct btf_dump_test_case *t)
return err;
}
+static char *dump_buf;
+static size_t dump_buf_sz;
+static FILE *dump_buf_file;
+
+void test_btf_dump_incremental(void)
+{
+ struct btf *btf = NULL;
+ struct btf_dump *d = NULL;
+ struct btf_dump_opts opts;
+ int id, err, i;
+
+ dump_buf_file = open_memstream(&dump_buf, &dump_buf_sz);
+ if (!ASSERT_OK_PTR(dump_buf_file, "dump_memstream"))
+ return;
+ btf = btf__new_empty();
+ if (!ASSERT_OK_PTR(btf, "new_empty"))
+ goto err_out;
+ opts.ctx = dump_buf_file;
+ d = btf_dump__new(btf, NULL, &opts, btf_dump_printf);
+ if (!ASSERT_OK(libbpf_get_error(d), "btf_dump__new"))
+ goto err_out;
+
+ /* First, generate BTF corresponding to the following C code:
+ *
+ * enum { VAL = 1 };
+ *
+ * struct s { int x; };
+ *
+ */
+ id = btf__add_enum(btf, NULL, 4);
+ ASSERT_EQ(id, 1, "enum_id");
+ err = btf__add_enum_value(btf, "VAL", 1);
+ ASSERT_OK(err, "enum_val_ok");
+
+ id = btf__add_int(btf, "int", 4, BTF_INT_SIGNED);
+ ASSERT_EQ(id, 2, "int_id");
+
+ id = btf__add_struct(btf, "s", 4);
+ ASSERT_EQ(id, 3, "struct_id");
+ err = btf__add_field(btf, "x", 2, 0, 0);
+ ASSERT_OK(err, "field_ok");
+
+ for (i = 1; i <= btf__get_nr_types(btf); i++) {
+ err = btf_dump__dump_type(d, i);
+ ASSERT_OK(err, "dump_type_ok");
+ }
+
+ fflush(dump_buf_file);
+ dump_buf[dump_buf_sz] = 0; /* some libc implementations don't do this */
+ ASSERT_STREQ(dump_buf,
+"enum {\n"
+" VAL = 1,\n"
+"};\n"
+"\n"
+"struct s {\n"
+" int x;\n"
+"};\n\n", "c_dump1");
+
+ /* Now, after dumping original BTF, append another struct that embeds
+ * anonymous enum. It also has a name conflict with the first struct:
+ *
+ * struct s___2 {
+ * enum { VAL___2 = 1 } x;
+ * struct s s;
+ * };
+ *
+ * This will test that btf_dump'er maintains internal state properly.
+ * Note that VAL___2 enum value. It's because we've already emitted
+ * that enum as a global anonymous enum, so btf_dump will ensure that
+ * enum values don't conflict;
+ *
+ */
+ fseek(dump_buf_file, 0, SEEK_SET);
+
+ id = btf__add_struct(btf, "s", 4);
+ ASSERT_EQ(id, 4, "struct_id");
+ err = btf__add_field(btf, "x", 1, 0, 0);
+ ASSERT_OK(err, "field_ok");
+ err = btf__add_field(btf, "s", 3, 32, 0);
+ ASSERT_OK(err, "field_ok");
+
+ for (i = 1; i <= btf__get_nr_types(btf); i++) {
+ err = btf_dump__dump_type(d, i);
+ ASSERT_OK(err, "dump_type_ok");
+ }
+
+ fflush(dump_buf_file);
+ dump_buf[dump_buf_sz] = 0; /* some libc implementations don't do this */
+ ASSERT_STREQ(dump_buf,
+"struct s___2 {\n"
+" enum {\n"
+" VAL___2 = 1,\n"
+" } x;\n"
+" struct s s;\n"
+"};\n\n" , "c_dump1");
+
+err_out:
+ fclose(dump_buf_file);
+ free(dump_buf);
+ btf_dump__free(d);
+ btf__free(btf);
+}
+
void test_btf_dump() {
int i;
@@ -140,4 +243,6 @@ void test_btf_dump() {
test_btf_dump_case(i, &btf_dump_test_cases[i]);
}
+ if (test__start_subtest("btf_dump: incremental"))
+ test_btf_dump_incremental();
}
Add test validating that btf_dump works fine with BTFs that are modified and incrementally generated. Signed-off-by: Andrii Nakryiko <andriin@fb.com> --- .../selftests/bpf/prog_tests/btf_dump.c | 105 ++++++++++++++++++ 1 file changed, 105 insertions(+)