Tag some char arrays with __attribute__ ((__nonstring__))

[ac000]

As previously promised, this PR comprises three commits that allow us to re-enable the new GCC 15 warning Wunterminated-string-initialization.

• The first commit adds a wrapper around __attribute__ ((__nonstring__))

As a reminder, this attribute is used to mark character arrays that are intentionally not NUL terminated.

• The second commit tags various character arrays with this attribute.

• The third commit removes the disabling of this new warning.

The following changes since commit d7afeb2b94f1cd72ed02403609e5484f9514e5eb:

  java: websocket: Additional payload length validation (2025-02-21 22:49:15 +0000)

are available in the Git repository at:

  git@github.com:ac000/unit.git wusi

for you to fetch changes up to ca60536172916b7c3e4ff62e20be1ae2f3de039d:

  auto/cc: gcc: Don't disable -Wunterminated-string-initialization (2025-03-19 17:58:37 +0000)

----------------------------------------------------------------
Andrew Clayton (3):
      auto/clang: Add a NXT_NONSTRING macro
      Tag various character arrays with NXT_NONSTRING
      auto/cc: gcc: Don't disable -Wunterminated-string-initialization

 auto/cc/test         |  4 ----
 auto/clang           | 14 ++++++++++++++
 src/nxt_clang.h      | 11 +++++++++++
 src/nxt_http_parse.c |  2 +-
 src/nxt_http_parse.h |  2 +-
 src/nxt_sprintf.c    |  4 ++--
 src/nxt_string.c     |  4 ++--
 7 files changed, 31 insertions(+), 10 deletions(-)

[ac000]

Cc: @alejandro-colomar

[ac000]

@hongzhidao

Thanks to @alejandro-colomar pointing out my idiocy, your qualms about the nxt_http_ver_t union initialisation changes should be neutralised, I.e. they don't change now.

$ git range-diff 6a272400...ca605361
1:  52529aa2 ! 1:  764ad73f auto/clang: Add a NXT_NONSTRING macro
    @@ Commit message
         Link: <https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git;h=622968990beee7499e951590258363545b4a3b57>
         Link: <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117178#c21>
         Cc: Alejandro Colomar <alx@kernel.org>
    +    Reviewed-by: Alejandro Colomar <alx@kernel.org>
         Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
     
      ## auto/clang ##
2:  34ae3a0f ! 2:  b53d03c2 Tag various character arrays with NXT_NONSTRING
    @@ Commit message
         happening.
     
         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>
     
      ## src/nxt_http_parse.c ##
    -@@ src/nxt_http_parse.c: nxt_http_parse_request_line(nxt_http_request_parse_t *rp, u_char **pos,
    -     nxt_http_ver_t           ver;
    -     nxt_http_target_traps_e  trap;
    - 
    --    static const nxt_http_ver_t  http11 = { "HTTP/1.1" };
    --    static const nxt_http_ver_t  http10 = { "HTTP/1.0" };
    -+    static const u_char          http11_str[8] NXT_NONSTRING = "HTTP/1.1";
    -+    static const u_char          http10_str[8] NXT_NONSTRING = "HTTP/1.0";
    -+    static const nxt_http_ver_t  *http11 = (nxt_http_ver_t *)http11_str;
    -+    static const nxt_http_ver_t  *http10 = (nxt_http_ver_t *)http10_str;
    - 
    -     p = *pos;
    - 
    -@@ src/nxt_http_parse.c: nxt_http_parse_request_line(nxt_http_request_parse_t *rp, u_char **pos,
    - 
    -     nxt_memcpy(ver.str, &p[1], 8);
    - 
    --    if (nxt_fast_path(ver.ui64 == http11.ui64
    --                      || ver.ui64 == http10.ui64
    -+    if (nxt_fast_path(ver.ui64 == http11->ui64
    -+                      || ver.ui64 == http10->ui64
    -                       || (memcmp(ver.str, "HTTP/1.", 7) == 0
    -                           && ver.s.minor >= '0' && ver.s.minor <= '9')))
    -     {
     @@ src/nxt_http_parse.c: nxt_http_parse_field_name(nxt_http_request_parse_t *rp, u_char **pos,
          size_t    len;
          uint32_t  hash;
    @@ src/nxt_http_parse.c: nxt_http_parse_field_name(nxt_http_request_parse_t *rp, u_
          /*   \s ! " # $ % & ' ( ) * + ,        . /                 : ; < = > ?   */
              "\0\1\0\1\1\1\1\1\0\0\1\1\0" "-" "\1\0" "0123456789" "\0\0\0\0\0\0"
     
    + ## src/nxt_http_parse.h ##
    +@@ src/nxt_http_parse.h: 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 {
    +
      ## src/nxt_sprintf.c ##
     @@ src/nxt_sprintf.c: nxt_vsprintf(u_char *buf, u_char *end, const char *fmt, va_list args)
          nxt_sprintf_t        spf;
3:  6a272400 ! 3:  ca605361 auto/cc: gcc: Don't disable -Wunterminated-string-initialization
    @@ Commit message
     
         Fixes: 150378224 ("Fix build with GCC 15")
         Cc: Alejandro Colomar <alx@kernel.org>
    +    Reviewed-by: Alejandro Colomar <alx@kernel.org>
         Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
     
      ## auto/cc/test ##

[ac000]

Fix a commit message.

$ git range-diff ca605361...ec1608b4
1:  b53d03c2 ! 1:  d9c2fd79 Tag various character arrays with NXT_NONSTRING
    @@ Commit message
     
         we no longer get the warning.
     
    -    We need to split the funky union initialisation in
    -    nxt_http_parse_request_line() into two parts, initialise the HTTP
    -    version string arrays then use them to initialise the unions, as you
    -    can't apply the attribute to non char base types.
    -
    -    It could be argued that this actually makes it clearer what is
    -    happening.
    -
         Cc: Alejandro Colomar <alx@kernel.org>
         Co-authored-by: Alejandro Colomar <alx@kernel.org>
         Signed-off-by: Alejandro Colomar <alx@kernel.org>
2:  ca605361 = 2:  ec1608b4 auto/cc: gcc: Don't disable -Wunterminated-string-initialization

[ac000]

Thanks guys!