Tag various character arrays with NXT_NONSTRING

In Unit we have a number of character arrays which are intentionally not
NUL terminated.

With GCC 15 this

  static const char hex[16] = "0123456789ABCDEF";

will trigger a warning like

  $ gcc -Wextra -c nonstring.c
  nonstring.c: In function ‘hexit’:
  nonstring.c:9:37: warning: initializer-string for array of ‘char’ truncates NUL terminator but destination lacks ‘nonstring’ attribute (17 chars into 16 available) [-Wunterminated-string-initialization]
      9 |         static const char hex[16] = "0123456789ABCDEF";
        |                                     ^~~~~~~~~~~~~~~~~~

By adding NXT_NONSTRING like

  static const char hex[16] NXT_NONSTRING = "0123456789ABCDEF";

we no longer get the warning.

Cc: Alejandro Colomar <alx@kernel.org>
Co-authored-by: Alejandro Colomar <alx@kernel.org>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/nxt_http_parse.h b/src/nxt_http_parse.h
index 9e2f6fab..157dc47d 100644
--- a/src/nxt_http_parse.h
+++ b/src/nxt_http_parse.h
@@ -21,7 +21,7 @@ typedef struct nxt_http_fields_hash_s    nxt_http_fields_hash_t;
 
 
 typedef union {
-    u_char                    str[8];
+    u_char                    str[8] NXT_NONSTRING;
     uint64_t                  ui64;
 
     struct {