// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
#include <bpf/btf.h>

static int duration = 0;

void btf_dump_printf(void *ctx, const char *fmt, va_list args)
{
        vfprintf(ctx, fmt, args);
}

static struct btf_dump_test_case {
        const char *name;
        const char *file;
        bool known_ptr_sz;
        struct btf_dump_opts opts;
} btf_dump_test_cases[] = {
        {"btf_dump: syntax", "btf_dump_test_case_syntax", true, {}},
        {"btf_dump: ordering", "btf_dump_test_case_ordering", false, {}},
        {"btf_dump: padding", "btf_dump_test_case_padding", true, {}},
        {"btf_dump: packing", "btf_dump_test_case_packing", true, {}},
        {"btf_dump: bitfields", "btf_dump_test_case_bitfields", true, {}},
        {"btf_dump: multidim", "btf_dump_test_case_multidim", false, {}},
        {"btf_dump: namespacing", "btf_dump_test_case_namespacing", false, {}},
};

static int btf_dump_all_types(const struct btf *btf,
                              const struct btf_dump_opts *opts)
{
        size_t type_cnt = btf__get_nr_types(btf);
        struct btf_dump *d;
        int err = 0, id;

        d = btf_dump__new(btf, NULL, opts, btf_dump_printf);
        if (IS_ERR(d))
                return PTR_ERR(d);

        for (id = 1; id <= type_cnt; id++) {
                err = btf_dump__dump_type(d, id);
                if (err)
                        goto done;
        }

done:
        btf_dump__free(d);
        return err;
}

static int test_btf_dump_case(int n, struct btf_dump_test_case *t)
{
        char test_file[256], out_file[256], diff_cmd[1024];
        struct btf *btf = NULL;
        int err = 0, fd = -1;
        FILE *f = NULL;

        snprintf(test_file, sizeof(test_file), "%s.o", t->file);

        btf = btf__parse_elf(test_file, NULL);
        if (CHECK(IS_ERR(btf), "btf_parse_elf",
            "failed to load test BTF: %ld\n", PTR_ERR(btf))) {
                err = -PTR_ERR(btf);
                btf = NULL;
                goto done;
        }

        /* tests with t->known_ptr_sz have no "long" or "unsigned long" type,
         * so it's impossible to determine correct pointer size; but if they
         * do, it should be 8 regardless of host architecture, becaues BPF
         * target is always 64-bit
         */
        if (!t->known_ptr_sz) {
                btf__set_pointer_size(btf, 8);
        } else {
                CHECK(btf__pointer_size(btf) != 8, "ptr_sz", "exp %d, got %zu\n",
                      8, btf__pointer_size(btf));
        }

        snprintf(out_file, sizeof(out_file), "/tmp/%s.output.XXXXXX", t->file);
        fd = mkstemp(out_file);
        if (CHECK(fd < 0, "create_tmp", "failed to create file: %d\n", fd)) {
                err = fd;
                goto done;
        }
        f = fdopen(fd, "w");
        if (CHECK(f == NULL, "open_tmp",  "failed to open file: %s(%d)\n",
                  strerror(errno), errno)) {
                close(fd);
                goto done;
        }

        t->opts.ctx = f;
        err = btf_dump_all_types(btf, &t->opts);
        fclose(f);
        close(fd);
        if (CHECK(err, "btf_dump", "failure during C dumping: %d\n", err)) {
                goto done;
        }

        snprintf(test_file, sizeof(test_file), "progs/%s.c", t->file);
        if (access(test_file, R_OK) == -1)
                /*
                 * When the test is run with O=, kselftest copies TEST_FILES
                 * without preserving the directory structure.
                 */
                snprintf(test_file, sizeof(test_file), "%s.c", t->file);
        /*
         * Diff test output and expected test output, contained between
         * START-EXPECTED-OUTPUT and END-EXPECTED-OUTPUT lines in test case.
         * For expected output lines, everything before '*' is stripped out.
         * Also lines containing comment start and comment end markers are
         * ignored. 
         */
        snprintf(diff_cmd, sizeof(diff_cmd),
                 "awk '/START-EXPECTED-OUTPUT/{out=1;next} "
                 "/END-EXPECTED-OUTPUT/{out=0} "
                 "/\\/\\*|\\*\\//{next} " /* ignore comment start/end lines */
                 "out {sub(/^[ \\t]*\\*/, \"\"); print}' '%s' | diff -u - '%s'",
                 test_file, out_file);
        err = system(diff_cmd);
        if (CHECK(err, "diff",
                  "differing test output, output=%s, err=%d, diff cmd:\n%s\n",
                  out_file, err, diff_cmd))
                goto done;

        remove(out_file);

done:
        btf__free(btf);
        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;

        for (i = 0; i < ARRAY_SIZE(btf_dump_test_cases); i++) {
                struct btf_dump_test_case *t = &btf_dump_test_cases[i];

                if (!test__start_subtest(t->name))
                        continue;

                test_btf_dump_case(i, &btf_dump_test_cases[i]);
        }
        if (test__start_subtest("btf_dump: incremental"))
                test_btf_dump_incremental();
}