more POSIX 2008 cleanup: strnlen(), rindex()

From 9f6fd1349ef9e726f6baf16777ca1658da8567b2 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Sat, 3 Jan 2026 10:11:19 +0100
Subject: [PATCH 1/2] strnlen() is now required

Remove all configure checks and workarounds for strnlen() missing.  It
is required by POSIX 2008.
---
 configure                  | 23 -----------------------
 configure.ac               |  3 +--
 meson.build                |  2 --
 src/include/pg_config.h.in |  7 -------
 src/include/port.h         |  4 ----
 src/port/meson.build       |  1 -
 src/port/strnlen.c         | 33 ---------------------------------
 7 files changed, 1 insertion(+), 72 deletions(-)
 delete mode 100644 src/port/strnlen.c

diff --git a/configure b/configure
index 78597c6229a..d34529b1de0 100755
--- a/configure
+++ b/configure
@@ -16079,16 +16079,6 @@ fi
 cat >>confdefs.h <<_ACEOF
 #define HAVE_DECL_STRLCPY $ac_have_decl
 _ACEOF
-ac_fn_c_check_decl "$LINENO" "strnlen" "ac_cv_have_decl_strnlen" "$ac_includes_default"
-if test "x$ac_cv_have_decl_strnlen" = xyes; then :
-  ac_have_decl=1
-else
-  ac_have_decl=0
-fi
-
-cat >>confdefs.h <<_ACEOF
-#define HAVE_DECL_STRNLEN $ac_have_decl
-_ACEOF
 ac_fn_c_check_decl "$LINENO" "strsep" "ac_cv_have_decl_strsep" "$ac_includes_default"
 if test "x$ac_cv_have_decl_strsep" = xyes; then :
   ac_have_decl=1
@@ -16268,19 +16258,6 @@ esac
 
 fi
 
-ac_fn_c_check_func "$LINENO" "strnlen" "ac_cv_func_strnlen"
-if test "x$ac_cv_func_strnlen" = xyes; then :
-  $as_echo "#define HAVE_STRNLEN 1" >>confdefs.h
-
-else
-  case " $LIBOBJS " in
-  *" strnlen.$ac_objext "* ) ;;
-  *) LIBOBJS="$LIBOBJS strnlen.$ac_objext"
- ;;
-esac
-
-fi
-
 ac_fn_c_check_func "$LINENO" "strsep" "ac_cv_func_strsep"
 if test "x$ac_cv_func_strsep" = xyes; then :
   $as_echo "#define HAVE_STRSEP 1" >>confdefs.h
diff --git a/configure.ac b/configure.ac
index 2ccf410f94c..284a2a4c498 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1825,7 +1825,7 @@ AC_CHECK_DECLS(posix_fadvise, [], [], [#include <fcntl.h>])
 ]) # fi
 
 AC_CHECK_DECLS(fdatasync, [], [], [#include <unistd.h>])
-AC_CHECK_DECLS([strlcat, strlcpy, strnlen, strsep, timingsafe_bcmp])
+AC_CHECK_DECLS([strlcat, strlcpy, strsep, timingsafe_bcmp])
 
 # We can't use AC_CHECK_FUNCS to detect these functions, because it
 # won't handle deployment target restrictions on macOS
@@ -1846,7 +1846,6 @@ AC_REPLACE_FUNCS(m4_normalize([
 	mkdtemp
 	strlcat
 	strlcpy
-	strnlen
 	strsep
 	timingsafe_bcmp
 ]))
diff --git a/meson.build b/meson.build
index 467f7f005a6..8289187c182 100644
--- a/meson.build
+++ b/meson.build
@@ -2664,7 +2664,6 @@ decl_checks = [
   ['posix_fadvise', 'fcntl.h'],
   ['strlcat', 'string.h'],
   ['strlcpy', 'string.h'],
-  ['strnlen', 'string.h'],
   ['strsep',  'string.h'],
   ['timingsafe_bcmp',  'string.h'],
 ]
@@ -2912,7 +2911,6 @@ func_checks = [
   ['strerror_r', {'dependencies': [thread_dep]}],
   ['strlcat'],
   ['strlcpy'],
-  ['strnlen'],
   ['strsep'],
   ['strsignal'],
   ['sync_file_range'],
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index f0091b09cbe..54ee5ccabbe 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -111,10 +111,6 @@
    don't. */
 #undef HAVE_DECL_STRLCPY
 
-/* Define to 1 if you have the declaration of `strnlen', and to 0 if you
-   don't. */
-#undef HAVE_DECL_STRNLEN
-
 /* Define to 1 if you have the declaration of `strsep', and to 0 if you don't.
    */
 #undef HAVE_DECL_STRSEP
@@ -401,9 +397,6 @@
 /* Define to 1 if you have the `strlcpy' function. */
 #undef HAVE_STRLCPY
 
-/* Define to 1 if you have the `strnlen' function. */
-#undef HAVE_STRNLEN
-
 /* Define to 1 if you have the `strsep' function. */
 #undef HAVE_STRSEP
 
diff --git a/src/include/port.h b/src/include/port.h
index 11b21098a39..e9e81cefef7 100644
--- a/src/include/port.h
+++ b/src/include/port.h
@@ -476,10 +476,6 @@ extern size_t strlcat(char *dst, const char *src, size_t siz);
 extern size_t strlcpy(char *dst, const char *src, size_t siz);
 #endif
 
-#if !HAVE_DECL_STRNLEN
-extern size_t strnlen(const char *str, size_t maxlen);
-#endif
-
 #if !HAVE_DECL_STRSEP
 extern char *strsep(char **stringp, const char *delim);
 #endif
diff --git a/src/port/meson.build b/src/port/meson.build
index c1ef6fd4821..28655142ebe 100644
--- a/src/port/meson.build
+++ b/src/port/meson.build
@@ -72,7 +72,6 @@ replace_funcs_neg = [
   ['mkdtemp'],
   ['strlcat'],
   ['strlcpy'],
-  ['strnlen'],
   ['strsep'],
   ['timingsafe_bcmp'],
 ]
diff --git a/src/port/strnlen.c b/src/port/strnlen.c
deleted file mode 100644
index 13f87377d21..00000000000
--- a/src/port/strnlen.c
+++ /dev/null
@@ -1,33 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * strnlen.c
- *		Fallback implementation of strnlen().
- *
- *
- * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * IDENTIFICATION
- *	  src/port/strnlen.c
- *
- *-------------------------------------------------------------------------
- */
-
-#include "c.h"
-
-/*
- * Implementation of posix' strnlen for systems where it's not available.
- *
- * Returns the number of characters before a null-byte in the string pointed
- * to by str, unless there's no null-byte before maxlen. In the latter case
- * maxlen is returned.
- */
-size_t
-strnlen(const char *str, size_t maxlen)
-{
-	const char *p = str;
-
-	while (maxlen-- > 0 && *p)
-		p++;
-	return p - str;
-}

base-commit: 094b61ce3ebbb1258675cb9b4eca9198628e2177
-- 
2.52.0

From 936cc7cbb5981ea8be1a4c0c2c3c5bf37e69a8ad Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Sat, 3 Jan 2026 10:16:50 +0100
Subject: [PATCH 2/2] Remove use of rindex() function

rindex() has been removed from POSIX 2008.  Replace the one remaining
use with the equivalent and more standard strrchr().
---
 src/backend/jit/llvm/llvmjit.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/jit/llvm/llvmjit.c b/src/backend/jit/llvm/llvmjit.c
index 49e76153f9a..8d009dd5cf7 100644
--- a/src/backend/jit/llvm/llvmjit.c
+++ b/src/backend/jit/llvm/llvmjit.c
@@ -1058,7 +1058,7 @@ llvm_split_symbol_name(const char *name, char **modname, char **funcname)
 		 * Symbol names cannot contain a ., therefore we can split based on
 		 * first and last occurrence of one.
 		 */
-		*funcname = rindex(name, '.');
+		*funcname = strrchr(name, '.');
 		(*funcname)++;			/* jump over . */
 
 		*modname = pnstrdup(name + strlen("pgextern."),
-- 
2.52.0