Build failure with GCC 15

[remicollet]

In file included from src/njs_main.h:59,
                 from src/njs_arr.c:8:
src/njs_string.h: In function ‘njs_string_encode’:
src/njs_string.h:212:36: error: initializer-string for array of ‘unsigned char’ is too long [-Werror=unterminated-string-initialization]
  212 |     static const u_char  hex[16] = "0123456789ABCDEF";
      |                                    ^~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors

[remicollet]

Also in some other places

In file included from src/njs_main.h:43,
                 from src/njs_object.c:8:
src/njs_object.c:2200:29: error: initializer-string for array of ‘unsigned char’ is too long [-Werror=unterminated-string-initialization]
 2200 |     NJS_DECLARE_PROP_NATIVE("defineProperty", njs_object_define_property, 3, 0),
      |                             ^~~~~~~~~~~~~~~~
src/njs_value.h:417:18: note: in definition of macro ‘njs_string’
  417 |         .start = s,                                                           \
      |                  ^
src/njs_object_prop_declare.h:33:5: note: in expansion of macro ‘NJS_DECLARE_PROP_VALUE’
   33 |     NJS_DECLARE_PROP_VALUE(_name,                                             \
      |     ^~~~~~~~~~~~~~~~~~~~~~
src/njs_object.c:2200:5: note: in expansion of macro ‘NJS_DECLARE_PROP_NATIVE’
 2200 |     NJS_DECLARE_PROP_NATIVE("defineProperty", njs_object_define_property, 3, 0),
      |     ^~~~~~~~~~~~~~~~~~~~~~~
src/njs_object.c:2217:29: error: initializer-string for array of ‘unsigned char’ is too long [-Werror=unterminated-string-initialization]
 2217 |     NJS_DECLARE_PROP_NATIVE("getPrototypeOf", njs_object_get_prototype_of, 1,
      |                             ^~~~~~~~~~~~~~~~
src/njs_value.h:417:18: note: in definition of macro ‘njs_string’
  417 |         .start = s,                                                           \
      |                  ^
src/njs_object_prop_declare.h:33:5: note: in expansion of macro ‘NJS_DECLARE_PROP_VALUE’
   33 |     NJS_DECLARE_PROP_VALUE(_name,                                             \
      |     ^~~~~~~~~~~~~~~~~~~~~~
src/njs_object.c:2217:5: note: in expansion of macro ‘NJS_DECLARE_PROP_NATIVE’
 2217 |     NJS_DECLARE_PROP_NATIVE("getPrototypeOf", njs_object_get_prototype_of, 1,
      |     ^~~~~~~~~~~~~~~~~~~~~~~
src/njs_object.c:2220:29: error: initializer-string for array of ‘unsigned char’ is too long [-Werror=unterminated-string-initialization]
 2220 |     NJS_DECLARE_PROP_NATIVE("setPrototypeOf", njs_object_set_prototype_of, 2,
      |                             ^~~~~~~~~~~~~~~~
src/njs_value.h:417:18: note: in definition of macro ‘njs_string’
  417 |         .start = s,                                                           \
      |                  ^
src/njs_object_prop_declare.h:33:5: note: in expansion of macro ‘NJS_DECLARE_PROP_VALUE’
   33 |     NJS_DECLARE_PROP_VALUE(_name,                                             \
      |     ^~~~~~~~~~~~~~~~~~~~~~
src/njs_object.c:2220:5: note: in expansion of macro ‘NJS_DECLARE_PROP_NATIVE’
 2220 |     NJS_DECLARE_PROP_NATIVE("setPrototypeOf", njs_object_set_prototype_of, 2,
      |     ^~~~~~~~~~~~~~~~~~~~~~~
src/njs_object.c:2472:49: error: initializer-string for array of ‘unsigned char’ is too long [-Werror=unterminated-string-initialization]
 2472 |                                      njs_string("[object Array]");
      |                                                 ^~~~~~~~~~~~~~~~
src/njs_value.h:417:18: note: in definition of macro ‘njs_string’
  417 |         .start = s,                                                           \
      |                  ^
src/njs_object.c:2479:49: error: initializer-string for array of ‘unsigned char’ is too long [-Werror=unterminated-string-initialization]
 2479 |                                      njs_string("[object Error]");
      |                                                 ^~~~~~~~~~~~~~~~
src/njs_value.h:417:18: note: in definition of macro ‘njs_string’
  417 |         .start = s,                                                           \
      |                  ^
src/njs_object.c:2733:29: error: initializer-string for array of ‘unsigned char’ is too long [-Werror=unterminated-string-initialization]
 2733 |     NJS_DECLARE_PROP_NATIVE("hasOwnProperty",
      |                             ^~~~~~~~~~~~~~~~
src/njs_value.h:417:18: note: in definition of macro ‘njs_string’
  417 |         .start = s,                                                           \
      |                  ^
src/njs_object_prop_declare.h:33:5: note: in expansion of macro ‘NJS_DECLARE_PROP_VALUE’
   33 |     NJS_DECLARE_PROP_VALUE(_name,                                             \
      |     ^~~~~~~~~~~~~~~~~~~~~~
src/njs_object.c:2733:5: note: in expansion of macro ‘NJS_DECLARE_PROP_NATIVE’
 2733 |     NJS_DECLARE_PROP_NATIVE("hasOwnProperty",
      |     ^~~~~~~~~~~~~~~~~~~~~~~

[remicollet]

Adding -Wno-error=unterminated-string-initialization to CFLAGS is a temporary workaround

[hongzhidao]

Hi @remicollet,
I wonder if the warning option turned on by default in GCC 15?

[ac000]

I wonder if the warning option turned on by default in GCC 15?

This is a new option (also enabled by -Wextra) in GCC 15. Remember this?

In Unit we temporarily disabled it, but now it can it can be quelled with the "nonstring" variable attribute. Unit PR to do this...

[hongzhidao]

Hi @ac000,
Good to remind, thanks.

[ac000]

Here's a PoC patch

diff --git a/auto/clang b/auto/clang
index 27fe03b5..31e0cf05 100644
--- a/auto/clang
+++ b/auto/clang
@@ -172,6 +172,20 @@ njs_feature_test="__attribute__((no_sanitize(\"undefined\"))) int main(void) {
 . auto/feature
 
 
+njs_feature="GCC __attribute__ nonstring"
+njs_feature_name=NJS_HAVE_GCC_ATTRIBUTE_NONSTRING
+njs_feature_run=
+njs_feature_incs=
+njs_feature_libs=
+njs_feature_test="int main(void) {
+                      static const char str[3] __attribute__((__nonstring__)) =
+                          \"ABC\";
+
+                      return !!str[0];
+                  }"
+. auto/feature
+
+
 njs_feature="Address sanitizer"
 njs_feature_name=NJS_HAVE_ADDRESS_SANITIZER
 njs_feature_run=no
diff --git a/src/njs_clang.h b/src/njs_clang.h
index 2bd45a74..587b72d7 100644
--- a/src/njs_clang.h
+++ b/src/njs_clang.h
@@ -162,6 +162,14 @@ njs_leading_zeros64(uint64_t x)
 #endif
 
 
+#if (NJS_HAVE_GCC_ATTRIBUTE_NONSTRING)
+#define NJS_NONSTRING      __attribute__((__nonstring__))
+
+#else
+#define NJS_NONSTRING
+#endif
+
+
 #if (NJS_CLANG)
 /* Any __asm__ directive disables loop vectorization in GCC and Clang. */
 #define njs_pragma_loop_disable_vectorization  __asm__("")
diff --git a/src/njs_sprintf.c b/src/njs_sprintf.c
index 16ae9004..d80fe396 100644
--- a/src/njs_sprintf.c
+++ b/src/njs_sprintf.c
@@ -95,8 +95,8 @@ njs_vsprintf(u_char *buf, u_char *end, const char *fmt, va_list args)
     njs_bool_t     sign;
     njs_sprintf_t  spf;
 
-    static const u_char  hexadecimal[16] = "0123456789abcdef";
-    static const u_char  HEXADECIMAL[16] = "0123456789ABCDEF";
+    static const u_char  hexadecimal[16] NJS_NONSTRING = "0123456789abcdef";
+    static const u_char  HEXADECIMAL[16] NJS_NONSTRING = "0123456789ABCDEF";
     static const u_char  nan[] = "[nan]";
     static const u_char  infinity[] = "[infinity]";
 
diff --git a/src/njs_string.c b/src/njs_string.c
index 9405a8db..1d13c33d 100644
--- a/src/njs_string.c
+++ b/src/njs_string.c
@@ -309,7 +309,7 @@ njs_encode_hex(njs_str_t *dst, const njs_str_t *src)
     size_t        i, len;
     const u_char  *start;
 
-    static const u_char  hex[16] = "0123456789abcdef";
+    static const u_char  hex[16] NJS_NONSTRING = "0123456789abcdef";
 
     len = src->length;
     start = src->start;
diff --git a/src/njs_string.h b/src/njs_string.h
index 686a5a74..f4830278 100644
--- a/src/njs_string.h
+++ b/src/njs_string.h
@@ -209,7 +209,7 @@ njs_string_encode(const uint32_t *escape, size_t size, const u_char *src,
     u_char *dst)
 {
     uint8_t              byte;
-    static const u_char  hex[16] = "0123456789ABCDEF";
+    static const u_char  hex[16] NJS_NONSTRING = "0123456789ABCDEF";
 
     do {
         byte = *src++;
diff --git a/src/njs_value.h b/src/njs_value.h
index 3751db71..15a278a7 100644
--- a/src/njs_value.h
+++ b/src/njs_value.h
@@ -147,7 +147,7 @@ union njs_value_s {
         uint8_t                       size:4;
         uint8_t                       length:4;
 
-        u_char                        start[NJS_STRING_SHORT];
+        u_char                        start[NJS_STRING_SHORT] NJS_NONSTRING;
     } short_string;
 
     struct {

I'm guessing it's correct to tag the start short_string union member, not that is has any material effect, but I'm assuming that the string doesn't need to be NUL terminated?

OTOH, if it does, we found a bug!

[xeioex]

@ac000

I'm guessing it's correct to tag the start short_string union member, not that is has any material effect, but I'm assuming that the string doesn't need to be NUL terminated?

No, it does not.

Thank you for the patch. Let me finish #848 first. It will move stuff a lot. After we finish I will take a look.

[ac000]

Ah, OK, so the short/long string distinction has been removed.

I'll create a draft PR and update it if required once that patchset has been merged.

Cheers,
Andrew