--- a/src/core/ngx_string.h
+++ b/src/core/ngx_string.h
@@ -38,6 +38,9 @@ typedef struct {
 
 #define ngx_string(str)     { sizeof(str) - 1, (u_char *) str }
 #define ngx_null_string     { 0, NULL }
+#define ngx_str_set(str, text)                                               \
+    (str)->len = sizeof(text) - 1; (str)->data = (u_char *) text
+#define ngx_str_null(str)   (str)->len = 0; (str)->data = NULL
 
 
 #define ngx_tolower(c)      (u_char) ((c >= 'A' && c <= 'Z') ? (c | 0x20) : c)