--- /dev/null
+From df17f4f37ed3ca373d23ad42eae51122bdb96626 Mon Sep 17 00:00:00 2001
+From: Paul Eggert <eggert@cs.ucla.edu>
+Date: Sun, 23 Nov 2025 00:50:40 -0800
+Subject: [PATCH] Port to C23 qualifier-generic fns like strchr
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+This ports Gnulib to strict C23 platforms that reject code
+like ‘char *q = strchr (P, 'x');’ when P is a pointer to const,
+because in C23 strchr is a qualifier-generic function so
+strchr (P, 'x') returns char const *.
+This patch does not attempt to do the following two things,
+which might be useful in the future:
+1. When compiling on non-C23 platforms, check user code for
+portability to platforms that define qualifier-generic functions.
+2. Port Gnulib to platforms that have qualifier-generic functions
+not listed in the C23 standard, e.g., strchrnul. I don’t know
+of any such platforms.
+* lib/argp-help.c (argp_doc):
+* lib/c-strstr.c (c_strstr):
+* lib/dfa.c (comsubs):
+* lib/mbschr.c (mbschr):
+* lib/mbspbrk.c (mbspbrk):
+* lib/mbsrchr.c (mbsrchr):
+* lib/memchr2.c (memchr2):
+* lib/string-desc.c (_sd_index):
+* tests/test-bsearch.c (lib_bsearch):
+* tests/test-memchr.c (lib_memchr):
+* tests/test-wmemchr.c (lib_wmemchr):
+Port to C23, where functions like strchr are qualifier-generic.
+* lib/c++defs.h (_GL_FUNCDECL_SYS_NAME): New macro.
+* lib/c++defs.h (_GL_FUNCDECL_SYS):
+* lib/stdlib.in.h (bsearch):
+Use it, to prevent C23 names like strchr from acting like macros.
+* lib/string.in.h (memchr, strchr, strpbrk, strrchr):
+Do not #undef when GNULIB_POSIXCHECK is defined, as this could
+cause conforming C23 code to fail to conform. It’s not clear why
+_GL_WARN_ON_USE_CXX; perhaps it was needed but isn’t any more?
+But for now, limit the removal of #undef to these four functions
+where #undeffing is clearly undesirable in C23.
+* lib/wchar.in.h (wmemchr): Parenthesize function name in decl,
+to prevent it from acting like a macro.
+---
+ ChangeLog | 40 ++++++++++++++++++++++++++++++++++++++++
+ lib/argp-help.c | 2 +-
+ lib/c++defs.h | 12 +++++++++++-
+ lib/c-strstr.c | 2 +-
+ lib/dfa.c | 2 +-
+ lib/mbschr.c | 2 +-
+ lib/mbspbrk.c | 2 +-
+ lib/mbsrchr.c | 2 +-
+ lib/memchr2.c | 2 +-
+ lib/stdlib.in.h | 6 +++---
+ lib/string-desc.c | 4 ++--
+ lib/string.in.h | 4 ----
+ lib/wchar.in.h | 2 +-
+ tests/test-bsearch.c | 2 +-
+ tests/test-memchr.c | 2 +-
+ tests/test-wmemchr.c | 2 +-
+ 16 files changed, 67 insertions(+), 21 deletions(-)
+
+--- a/lib/argp-help.c
++++ b/lib/argp-help.c
+@@ -1601,7 +1601,7 @@ argp_doc (const struct argp *argp, const
+
+ if (doc)
+ {
+- char *vt = strchr (doc, '\v');
++ char const *vt = strchr (doc, '\v');
+ inp_text = post ? (vt ? vt + 1 : NULL) : doc;
+ inp_text_limit = (!post && vt) ? (vt - doc) : 0;
+ }
+--- a/lib/c++defs.h
++++ b/lib/c++defs.h
+@@ -127,6 +127,16 @@
+ #define _GL_FUNCDECL_RPL_1(rpl_func,rettype,parameters,...) \
+ _GL_EXTERN_C_FUNC __VA_ARGS__ rettype rpl_func parameters
+
++/* _GL_FUNCDECL_SYS_NAME (func) expands to plain func if C++, and to
++ parenthsized func otherwise. Parenthesization is needed in C23 if
++ the function is like strchr and so is a qualifier-generic macro
++ that expands to something more complicated. */
++#ifdef __cplusplus
++# define _GL_FUNCDECL_SYS_NAME(func) func
++#else
++# define _GL_FUNCDECL_SYS_NAME(func) (func)
++#endif
++
+ /* _GL_FUNCDECL_SYS (func, rettype, parameters, [attributes]);
+ declares the system function, named func, with the given prototype,
+ consisting of return type, parameters, and attributes.
+@@ -139,7 +149,7 @@
+ _GL_FUNCDECL_SYS (posix_openpt, int, (int flags), _GL_ATTRIBUTE_NODISCARD);
+ */
+ #define _GL_FUNCDECL_SYS(func,rettype,parameters,...) \
+- _GL_EXTERN_C_FUNC __VA_ARGS__ rettype func parameters
++ _GL_EXTERN_C_FUNC __VA_ARGS__ rettype _GL_FUNCDECL_SYS_NAME (func) parameters
+
+ /* _GL_CXXALIAS_RPL (func, rettype, parameters);
+ declares a C++ alias called GNULIB_NAMESPACE::func
+--- a/lib/c-strstr.c
++++ b/lib/c-strstr.c
+@@ -28,5 +28,5 @@ c_strstr (const char *haystack, const ch
+ {
+ /* POSIX says that strstr() interprets the strings as byte sequences, not
+ as character sequences in the current locale. */
+- return strstr (haystack, needle);
++ return (char *) strstr (haystack, needle);
+ }
+--- a/lib/dfa.c
++++ b/lib/dfa.c
+@@ -4069,7 +4069,7 @@ comsubs (char *left, char const *right)
+ for (char *lcp = left; *lcp != '\0'; lcp++)
+ {
+ idx_t len = 0;
+- char *rcp = strchr (right, *lcp);
++ char const *rcp = strchr (right, *lcp);
+ while (rcp != NULL)
+ {
+ idx_t i;
+--- a/lib/mbschr.c
++++ b/lib/mbschr.c
+@@ -65,5 +65,5 @@ mbschr (const char *string, int c)
+ return NULL;
+ }
+ else
+- return strchr (string, c);
++ return (char *) strchr (string, c);
+ }
+--- a/lib/mbspbrk.c
++++ b/lib/mbspbrk.c
+@@ -90,5 +90,5 @@ mbspbrk (const char *string, const char
+ return NULL;
+ }
+ else
+- return strpbrk (string, accept);
++ return (char *) strpbrk (string, accept);
+ }
+--- a/lib/mbsrchr.c
++++ b/lib/mbsrchr.c
+@@ -64,5 +64,5 @@ mbsrchr (const char *string, int c)
+ return (char *) result;
+ }
+ else
+- return strrchr (string, c);
++ return (char *) strrchr (string, c);
+ }
+--- a/lib/memchr2.c
++++ b/lib/memchr2.c
+@@ -55,7 +55,7 @@ memchr2 (void const *s, int c1_in, int c
+ c2 = (unsigned char) c2_in;
+
+ if (c1 == c2)
+- return memchr (s, c1, n);
++ return (void *) memchr (s, c1, n);
+
+ /* Handle the first few bytes by reading one byte at a time.
+ Do this until VOID_PTR is aligned on a longword boundary. */
+--- a/lib/stdlib.in.h
++++ b/lib/stdlib.in.h
+@@ -238,9 +238,9 @@ _GL_INLINE_HEADER_BEGIN
+
+ /* Declarations for ISO C N3322. */
+ #if defined __GNUC__ && __GNUC__ >= 15 && !defined __clang__
+-_GL_EXTERN_C void *bsearch (const void *__key,
+- const void *__base, size_t __nmemb, size_t __size,
+- int (*__compare) (const void *, const void *))
++_GL_EXTERN_C void *_GL_FUNCDECL_SYS_NAME (bsearch)
++ (const void *__key, const void *__base, size_t __nmemb, size_t __size,
++ int (*__compare) (const void *, const void *))
+ _GL_ATTRIBUTE_NONNULL_IF_NONZERO (2, 3) _GL_ARG_NONNULL ((5));
+ _GL_EXTERN_C void qsort (void *__base, size_t __nmemb, size_t __size,
+ int (*__compare) (const void *, const void *))
+--- a/lib/string-desc.c
++++ b/lib/string-desc.c
+@@ -113,9 +113,9 @@ _sd_index (idx_t s_nbytes, const char *s
+ {
+ if (s_nbytes > 0)
+ {
+- void *found = memchr (s_data, (unsigned char) c, s_nbytes);
++ char const *found = memchr (s_data, (unsigned char) c, s_nbytes);
+ if (found != NULL)
+- return (char *) found - s_data;
++ return found - s_data;
+ }
+ return -1;
+ }
+--- a/lib/string.in.h
++++ b/lib/string.in.h
+@@ -403,7 +403,6 @@ _GL_CXXALIASWARN1 (memchr, void const *,
+ _GL_CXXALIASWARN (memchr);
+ # endif
+ #elif defined GNULIB_POSIXCHECK
+-# undef memchr
+ /* Assume memchr is always declared. */
+ _GL_WARN_ON_USE_CXX (memchr,
+ const void *, void *, (void const *, int, size_t),
+@@ -655,7 +654,6 @@ _GL_WARN_ON_USE (stpncpy, "stpncpy is un
+ #if defined GNULIB_POSIXCHECK
+ /* strchr() does not work with multibyte strings if the locale encoding is
+ GB18030 and the character to be searched is a digit. */
+-# undef strchr
+ /* Assume strchr is always declared. */
+ _GL_WARN_ON_USE_CXX (strchr,
+ const char *, char *, (const char *, int),
+@@ -976,7 +974,6 @@ _GL_CXXALIASWARN (strpbrk);
+ Even in this simple case, it does not work with multibyte strings if the
+ locale encoding is GB18030 and one of the characters to be searched is a
+ digit. */
+-# undef strpbrk
+ _GL_WARN_ON_USE_CXX (strpbrk,
+ const char *, char *, (const char *, const char *),
+ "strpbrk cannot work correctly on character strings "
+@@ -1006,7 +1003,6 @@ _GL_WARN_ON_USE (strspn, "strspn cannot
+ #if defined GNULIB_POSIXCHECK
+ /* strrchr() does not work with multibyte strings if the locale encoding is
+ GB18030 and the character to be searched is a digit. */
+-# undef strrchr
+ /* Assume strrchr is always declared. */
+ _GL_WARN_ON_USE_CXX (strrchr,
+ const char *, char *, (const char *, int),
+--- a/lib/wchar.in.h
++++ b/lib/wchar.in.h
+@@ -316,7 +316,7 @@ _GL_EXTERN_C int wcsncmp (const wchar_t
+ _GL_ATTRIBUTE_NONNULL_IF_NONZERO (1, 3)
+ _GL_ATTRIBUTE_NONNULL_IF_NONZERO (2, 3);
+ # ifndef __cplusplus
+-_GL_EXTERN_C wchar_t *wmemchr (const wchar_t *__s, wchar_t __wc, size_t __n)
++_GL_EXTERN_C wchar_t *(wmemchr) (const wchar_t *__s, wchar_t __wc, size_t __n)
+ _GL_ATTRIBUTE_NONNULL_IF_NONZERO (1, 3);
+ # endif
+ _GL_EXTERN_C wchar_t *wmemset (wchar_t *__s, wchar_t __wc, size_t __n)
+--- a/tests/test-bsearch.c
++++ b/tests/test-bsearch.c
+@@ -26,7 +26,7 @@ static void *
+ lib_bsearch (void const *key, void const *base, size_t nel, size_t width,
+ int (*compar) (void const *, void const *))
+ {
+- return bsearch (key, base, nel, width, compar);
++ return (void *) bsearch (key, base, nel, width, compar);
+ }
+ static void *(*volatile volatile_bsearch) (void const *, void const *, size_t,
+ size_t,
+--- a/tests/test-memchr.c
++++ b/tests/test-memchr.c
+@@ -31,7 +31,7 @@ SIGNATURE_CHECK (memchr, void *, (void c
+ static void *
+ lib_memchr (void const *s, int c, size_t n)
+ {
+- return memchr (s, c, n);
++ return (void *) memchr (s, c, n);
+ }
+ static void *(*volatile volatile_memchr) (void const *, int, size_t)
+ = lib_memchr;
+--- a/tests/test-wmemchr.c
++++ b/tests/test-wmemchr.c
+@@ -27,7 +27,7 @@
+ static wchar_t *
+ lib_wmemchr (wchar_t const *s, wchar_t wc, size_t n)
+ {
+- return wmemchr (s, wc, n);
++ return (wchar_t *) wmemchr (s, wc, n);
+ }
+ static wchar_t *(*volatile volatile_wmemchr) (wchar_t const *, wchar_t, size_t)
+ = lib_wmemchr;
projects / thirdparty / openwrt.git / commitdiff
