jsmn_parse can be called with a NULL buffer to determine the needed allocation size beforehand. Most users will go on to dynamically allocate that buffer, so add a helper that does just that and start using it to simplify the json selftest.
Signed-off-by: Ahmad Fatoum <[email protected]> --- include/jsmn.h | 6 ++++++ lib/jsmn.c | 36 ++++++++++++++++++++++++++++++++++++ test/self/json.c | 33 ++++----------------------------- 3 files changed, 46 insertions(+), 29 deletions(-) diff --git a/include/jsmn.h b/include/jsmn.h index 2dd1d5ffc08b..62197c2593b4 100644 --- a/include/jsmn.h +++ b/include/jsmn.h @@ -84,6 +84,12 @@ JSMN_API void jsmn_init(jsmn_parser *parser); JSMN_API int jsmn_parse(jsmn_parser *parser, const char *js, const size_t len, jsmntok_t *tokens, const unsigned int num_tokens); +/** + * Like jsmn_parse, but allocates tokens dynamically. + */ +JSMN_API jsmntok_t *jsmn_parse_alloc(const char *js, const size_t len, + unsigned int *num_tokens); + static inline int jsmn_token_size(const jsmntok_t *token) { return token->end - token->start; diff --git a/lib/jsmn.c b/lib/jsmn.c index 9eeed790d93d..3d2ada7b7fdc 100644 --- a/lib/jsmn.c +++ b/lib/jsmn.c @@ -370,6 +370,42 @@ JSMN_API void jsmn_init(jsmn_parser *parser) { parser->toksuper = -1; } +/** + * Parse JSON string and fill tokens into self-allocated buffer. + */ +JSMN_API jsmntok_t *jsmn_parse_alloc(const char *js, const size_t len, + unsigned int *num_tokens) +{ + + ssize_t token_count; + jsmn_parser parser; + jsmntok_t *tokens; + int ret; + + jsmn_init(&parser); + + /* Figure out how many tokens we need. */ + ret = jsmn_parse(&parser, js, len, NULL, 0); + if (ret < 0) + return NULL; + + token_count = ret; + + tokens = kmalloc_array(token_count, sizeof(jsmntok_t), GFP_KERNEL); + if (!tokens) + return NULL; + + jsmn_init(&parser); + ret = jsmn_parse(&parser, js, len, tokens, token_count); + if (ret < 0) { + free(tokens); + return NULL; + } + + if (num_tokens) + *num_tokens = ret; + return tokens; +} JSMN_API bool jsmn_eq(const char *val, const char *json, const jsmntok_t *token) { size_t token_size = jsmn_token_size(token); diff --git a/test/self/json.c b/test/self/json.c index 54323cf4350c..d3088f1b7542 100644 --- a/test/self/json.c +++ b/test/self/json.c @@ -75,45 +75,20 @@ static const char json[] = static void test_json(void) { - ssize_t token_count; const jsmntok_t *token; jsmntok_t *tokens; - jsmn_parser parser; char *string; - int ret; total_tests++; - jsmn_init(&parser); - /* Figure out how many tokens we need. */ - ret = jsmn_parse(&parser, json, sizeof(json), NULL, 0); - if (ret < 0) { - printf("failed to determine number of tokens: %d\n", ret); + tokens = jsmn_parse_alloc(json, sizeof(json), NULL); + if (!tokens) { + printf("failed to parse JSON\n"); failed_tests++; return; } - token_count = ret; - - /* `token_count` is strictly less than `length` which is strictly less - * than CONFIG_SYS_EEPROM_SIZE (or 8K), so we should never overflow an - * int here. - */ - tokens = kmalloc_array(token_count, sizeof(jsmntok_t), GFP_KERNEL); - if (WARN_ON(!tokens)) - return; - - total_tests++; - - jsmn_init(&parser); - ret = jsmn_parse(&parser, json, sizeof(json), tokens, token_count); - if (ret < 0) { - printf("failed to parse JSON with tokens: %d\n", ret); - failed_tests++; - goto out; - } - json_expect(json, tokens, JP("null"), JSMN_PRIMITIVE, "null"); json_expect(json, tokens, JP("number"), JSMN_PRIMITIVE, "0x42"); json_expect(json, tokens, JP("object"), JSMN_OBJECT, NULL); @@ -131,7 +106,7 @@ static void test_json(void) string = jsmn_strcpy(JP("string"), json, tokens); if (WARN_ON(!string)) - return; + goto out; total_tests++; if (strcmp(string, "Hello World\n")) { -- 2.39.2
