Add port/ replacement for strsep()

from OpenBSD, similar to strlcat, strlcpy

There are currently no uses, but some will be added soon.

Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-by: David Steele <david@pgmasters.net>
Discussion: https://www.postgresql.org/message-id/flat/79692bf9-17d3-41e6-b9c9-fc8c3944222a@eisentraut.org

configure

@@ -15778,6 +15778,16 @@ 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
+else
+  ac_have_decl=0
+fi
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_DECL_STRSEP $ac_have_decl
+_ACEOF
 
 
 # We can't use AC_CHECK_FUNCS to detect these functions, because it
@@ -15925,6 +15935,19 @@ 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
+
+else
+  case " $LIBOBJS " in
+  *" strsep.$ac_objext "* ) ;;
+  *) LIBOBJS="$LIBOBJS strsep.$ac_objext"
+ ;;
+esac
+
+fi
+
 
 
 ac_fn_c_check_func "$LINENO" "pthread_barrier_wait" "ac_cv_func_pthread_barrier_wait"

configure.ac

@@ -1795,7 +1795,7 @@ AC_CHECK_DECLS(posix_fadvise, [], [], [#include <fcntl.h>])
 ]) # fi
 
 AC_CHECK_DECLS(fdatasync, [], [], [#include <unistd.h>])
-AC_CHECK_DECLS([strlcat, strlcpy, strnlen])
+AC_CHECK_DECLS([strlcat, strlcpy, strnlen, strsep])
 
 # We can't use AC_CHECK_FUNCS to detect these functions, because it
 # won't handle deployment target restrictions on macOS
@@ -1814,6 +1814,7 @@ AC_REPLACE_FUNCS(m4_normalize([
 	strlcat
 	strlcpy
 	strnlen
+	strsep
 ]))
 
 AC_REPLACE_FUNCS(pthread_barrier_wait)

meson.build

@@ -2417,6 +2417,7 @@ decl_checks = [
   ['strlcat', 'string.h'],
   ['strlcpy', 'string.h'],
   ['strnlen', 'string.h'],
+  ['strsep',  'string.h'],
 ]
 
 # Need to check for function declarations for these functions, because
@@ -2685,6 +2686,7 @@ func_checks = [
   ['strlcat'],
   ['strlcpy'],
   ['strnlen'],
+  ['strsep'],
   ['strsignal'],
   ['sync_file_range'],
   ['syncfs'],

src/include/pg_config.h.in

@@ -127,6 +127,10 @@
    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
+
 /* Define to 1 if you have the <editline/history.h> header file. */
 #undef HAVE_EDITLINE_HISTORY_H
 
@@ -414,6 +418,9 @@
 /* Define to 1 if you have the `strnlen' function. */
 #undef HAVE_STRNLEN
 
+/* Define to 1 if you have the `strsep' function. */
+#undef HAVE_STRSEP
+
 /* Define to 1 if you have the `strsignal' function. */
 #undef HAVE_STRSIGNAL
 

src/include/port.h

@@ -432,6 +432,10 @@ extern size_t strlcpy(char *dst, const char *src, size_t siz);
 extern size_t strnlen(const char *str, size_t maxlen);
 #endif
 
+#if !HAVE_DECL_STRSEP
+extern char *strsep(char **stringp, const char *delim);
+#endif
+
 /* port/user.c */
 #ifndef WIN32
 extern bool pg_get_user_name(uid_t user_id, char *buffer, size_t buflen);

src/port/meson.build

@@ -70,6 +70,7 @@ replace_funcs_neg = [
   ['strlcat'],
   ['strlcpy'],
   ['strnlen'],
+  ['strsep'],
 ]
 
 if host_system != 'windows'

src/port/strsep.c

@@ -0,0 +1,77 @@
+/*
+ * src/port/strsep.c
+ *
+ *	$OpenBSD: strsep.c,v 1.8 2015/08/31 02:53:57 guenther Exp $	*/
+
+/*-
+ * Copyright (c) 1990, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "c.h"
+
+/*
+ * Get next token from string *stringp, where tokens are possibly-empty
+ * strings separated by characters from delim.
+ *
+ * Writes NULs into the string at *stringp to end tokens.
+ * delim need not remain constant from call to call.
+ * On return, *stringp points past the last NUL written (if there might
+ * be further tokens), or is NULL (if there are definitely no more tokens).
+ *
+ * If *stringp is NULL, strsep returns NULL.
+ */
+char *
+strsep(char **stringp, const char *delim)
+{
+	char	   *s;
+	const char *spanp;
+	int			c,
+				sc;
+	char	   *tok;
+
+	if ((s = *stringp) == NULL)
+		return (NULL);
+	for (tok = s;;)
+	{
+		c = *s++;
+		spanp = delim;
+		do
+		{
+			if ((sc = *spanp++) == c)
+			{
+				if (c == 0)
+					s = NULL;
+				else
+					s[-1] = 0;
+				*stringp = s;
+				return (tok);
+			}
+		} while (sc != 0);
+	}
+	/* NOTREACHED */
+}