fixup! fixup! sys/string_utils: add string_writer helper

sys/include/string_utils.h

@@ -87,6 +87,12 @@ static inline const char *string_writer_str(const string_writer_t *sw)
     return sw->start;
 }
 
+#if IS_ACTIVE(HAS_FLASH_UTILS_ARCH)
+#define __swprintf flash_swprintf
+#else
+#define __swprintf swprintf
+#endif
+
 /**
  * @brief   Write a formatted string to a buffer
  *          The string will be truncated if there is not enough space left in
@@ -99,8 +105,11 @@ static inline const char *string_writer_str(const string_writer_t *sw)
  * @return      number of bytes written on success
  *              -E2BIG if the string was truncated
  */
-__attribute__ ((format (printf, 2, 3)))
-int swprintf(string_writer_t *sw, FLASH_ATTR const char *restrict format, ...);
+int __swprintf(string_writer_t *sw, FLASH_ATTR const char *restrict format, ...);
+
+#if IS_ACTIVE(HAS_FLASH_UTILS_ARCH)
+#define swprintf(sw, fmt, ...) flash_swprintf(sw, TO_FLASH(fmt), ## __VA_ARGS__)
+#endif
 
 /* explicit_bzero is provided if:
  * - glibc is used as C lib (only with board natvie)

sys/libc/string.c

@@ -52,18 +52,20 @@ const void *memchk(const void *data, uint8_t c, size_t len)
     return NULL;
 }
 
-int swprintf(string_writer_t *sw, FLASH_ATTR const char *restrict format, ...)
+int __swprintf(string_writer_t *sw, FLASH_ATTR const char *restrict format, ...)
 {
     va_list args;
     int res;
 
-    /* make sure flash_vsnprintf() is not used */
-    #if HAS_FLASH_UTILS_ARCH
-    #undef vsnprintf
-    #endif
-
     va_start(args, format);
-    res = vsnprintf(sw->position, sw->capacity, format, args);
+#ifdef __clang__
+    _Pragma("clang diagnostic push") \
+    _Pragma("clang diagnostic ignored \"-Wformat-nonliteral\"") \
+    res = flash_vsnprintf(sw->position, sw->capacity, format, args);
+    _Pragma("clang diagnostic pop")
+#else
+    res = flash_vsnprintf(sw->position, sw->capacity, format, args);
+#endif
     va_end(args);
 
     if (res < (int)sw->capacity) {