To enable further rework to (efficiently) avoid using variable-length arrays, we first separate out the body of the __json_format_str function. This means that the actual VLA buffer is in the wrapper function, and means we can reuse the actual writing code in multiple code paths without duplication.
Signed-off-by: Bruce Richardson <bruce.richard...@intel.com> --- lib/telemetry/telemetry_json.h | 32 ++++++++++++++++++++++++-------- 1 file changed, 24 insertions(+), 8 deletions(-) diff --git a/lib/telemetry/telemetry_json.h b/lib/telemetry/telemetry_json.h index 1bddd124f9..aada523a27 100644 --- a/lib/telemetry/telemetry_json.h +++ b/lib/telemetry/telemetry_json.h @@ -80,15 +80,13 @@ static const char control_chars[0x20] = { /** * @internal - * This function acts the same as __json_snprintf(buf, len, "%s%s%s", prefix, str, suffix) - * except that it does proper escaping of "str" as necessary. Prefix and suffix should be compile- - * time constants, or values not needing escaping. - * Drops any invalid characters we don't support + * Function that does the actual printing, used by __json_format_str. Modifies buffer + * directly, but returns 0 on overflow. Otherwise returns number of chars written to buffer. */ static inline int -__json_format_str(char *buf, const int len, const char *prefix, const char *str, const char *suffix) +__json_format_str_to_buf(char *tmp, const int len, + const char *prefix, const char *str, const char *suffix) { - char tmp[len]; int tmpidx = 0; while (*prefix != '\0' && tmpidx < len) @@ -123,11 +121,29 @@ __json_format_str(char *buf, const int len, const char *prefix, const char *str, return 0; tmp[tmpidx] = '\0'; - - strcpy(buf, tmp); return tmpidx; } +/** + * @internal + * This function acts the same as __json_snprintf(buf, len, "%s%s%s", prefix, str, suffix) + * except that it does proper escaping of "str" as necessary. Prefix and suffix should be compile- + * time constants, or values not needing escaping. + * Drops any invalid characters we don't support + */ +static inline int +__json_format_str(char *buf, const int len, const char *prefix, const char *str, const char *suffix) +{ + char tmp[len]; + int ret; + + ret = __json_format_str_to_buf(tmp, len, prefix, str, suffix); + if (ret > 0) + strcpy(buf, tmp); + + return ret; +} + /* Copies an empty array into the provided buffer. */ static inline int rte_tel_json_empty_array(char *buf, const int len, const int used) -- 2.37.2