sys_siglist[] is causing us trouble again

diff --git a/configure b/configure
index 4e1b4be7fb..7382a34d60 100755
--- a/configure
+++ b/configure
@@ -15004,7 +15004,7 @@ fi
 LIBS_including_readline="$LIBS"
 LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
 
-for ac_func in cbrt clock_gettime dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll posix_fallocate pstat pthread_is_threaded_np readlink setproctitle setsid shm_open symlink sync_file_range uselocale utime utimes wcstombs_l
+for ac_func in cbrt clock_gettime dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll posix_fallocate pstat pthread_is_threaded_np readlink setproctitle setsid shm_open strsignal symlink sync_file_range uselocale utime utimes wcstombs_l
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
@@ -15893,24 +15893,6 @@ esac
 
 fi
 
-ac_fn_c_check_decl "$LINENO" "sys_siglist" "ac_cv_have_decl_sys_siglist" "#include <signal.h>
-/* NetBSD declares sys_siglist in unistd.h.  */
-#ifdef HAVE_UNISTD_H
-# include <unistd.h>
-#endif
-
-"
-if test "x$ac_cv_have_decl_sys_siglist" = xyes; then :
-  ac_have_decl=1
-else
-  ac_have_decl=0
-fi
-
-cat >>confdefs.h <<_ACEOF
-#define HAVE_DECL_SYS_SIGLIST $ac_have_decl
-_ACEOF
-
-
 ac_fn_c_check_func "$LINENO" "syslog" "ac_cv_func_syslog"
 if test "x$ac_cv_func_syslog" = xyes; then :
   ac_fn_c_check_header_mongrel "$LINENO" "syslog.h" "ac_cv_header_syslog_h" "$ac_includes_default"
diff --git a/configure.in b/configure.in
index fab1658bca..defcb8ff99 100644
--- a/configure.in
+++ b/configure.in
@@ -1622,6 +1622,7 @@ AC_CHECK_FUNCS(m4_normalize([
 	setproctitle
 	setsid
 	shm_open
+	strsignal
 	symlink
 	sync_file_range
 	uselocale
@@ -1821,14 +1822,6 @@ if test "$PORTNAME" = "cygwin"; then
   AC_LIBOBJ(dirmod)
 fi
 
-AC_CHECK_DECLS([sys_siglist], [], [],
-[#include <signal.h>
-/* NetBSD declares sys_siglist in unistd.h.  */
-#ifdef HAVE_UNISTD_H
-# include <unistd.h>
-#endif
-])
-
 AC_CHECK_FUNC(syslog,
               [AC_CHECK_HEADER(syslog.h,
                                [AC_DEFINE(HAVE_SYSLOG, 1, [Define to 1 if you have the syslog interface.])])])
diff --git a/src/backend/postmaster/pgarch.c b/src/backend/postmaster/pgarch.c
index 252220c770..08577f5e5f 100644
--- a/src/backend/postmaster/pgarch.c
+++ b/src/backend/postmaster/pgarch.c
@@ -596,17 +596,10 @@ pgarch_archiveXlog(char *xlog)
 					 errhint("See C include file \"ntstatus.h\" for a description of the hexadecimal value."),
 					 errdetail("The failed archive command was: %s",
 							   xlogarchcmd)));
-#elif defined(HAVE_DECL_SYS_SIGLIST) && HAVE_DECL_SYS_SIGLIST
-			ereport(lev,
-					(errmsg("archive command was terminated by signal %d: %s",
-							WTERMSIG(rc),
-							WTERMSIG(rc) < NSIG ? sys_siglist[WTERMSIG(rc)] : "(unknown)"),
-					 errdetail("The failed archive command was: %s",
-							   xlogarchcmd)));
 #else
 			ereport(lev,
-					(errmsg("archive command was terminated by signal %d",
-							WTERMSIG(rc)),
+					(errmsg("archive command was terminated by signal %d: %s",
+							WTERMSIG(rc), pg_strsignal(WTERMSIG(rc))),
 					 errdetail("The failed archive command was: %s",
 							   xlogarchcmd)));
 #endif
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 3bfc299be1..75a9e07041 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -3563,6 +3563,7 @@ LogChildExit(int lev, const char *procname, int pid, int exitstatus)
 						procname, pid, WEXITSTATUS(exitstatus)),
 				 activity ? errdetail("Failed process was running: %s", activity) : 0));
 	else if (WIFSIGNALED(exitstatus))
+	{
 #if defined(WIN32)
 		ereport(lev,
 
@@ -3573,7 +3574,7 @@ LogChildExit(int lev, const char *procname, int pid, int exitstatus)
 						procname, pid, WTERMSIG(exitstatus)),
 				 errhint("See C include file \"ntstatus.h\" for a description of the hexadecimal value."),
 				 activity ? errdetail("Failed process was running: %s", activity) : 0));
-#elif defined(HAVE_DECL_SYS_SIGLIST) && HAVE_DECL_SYS_SIGLIST
+#else
 		ereport(lev,
 
 		/*------
@@ -3581,19 +3582,10 @@ LogChildExit(int lev, const char *procname, int pid, int exitstatus)
 		  "server process" */
 				(errmsg("%s (PID %d) was terminated by signal %d: %s",
 						procname, pid, WTERMSIG(exitstatus),
-						WTERMSIG(exitstatus) < NSIG ?
-						sys_siglist[WTERMSIG(exitstatus)] : "(unknown)"),
-				 activity ? errdetail("Failed process was running: %s", activity) : 0));
-#else
-		ereport(lev,
-
-		/*------
-		  translator: %s is a noun phrase describing a child process, such as
-		  "server process" */
-				(errmsg("%s (PID %d) was terminated by signal %d",
-						procname, pid, WTERMSIG(exitstatus)),
+						pg_strsignal(WTERMSIG(exitstatus))),
 				 activity ? errdetail("Failed process was running: %s", activity) : 0));
 #endif
+	}
 	else
 		ereport(lev,
 
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 305dba20cb..662ba2bc3e 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -2014,7 +2014,7 @@ BaseBackup(void)
 	{
 #ifndef WIN32
 		int			status;
-		int			r;
+		pid_t		r;
 #else
 		DWORD		status;
 
@@ -2042,7 +2042,7 @@ BaseBackup(void)
 
 		/* Just wait for the background process to exit */
 		r = waitpid(bgchild, &status, 0);
-		if (r == -1)
+		if (r == (pid_t) -1)
 		{
 			fprintf(stderr, _("%s: could not wait for child process: %s\n"),
 					progname, strerror(errno));
@@ -2051,19 +2051,13 @@ BaseBackup(void)
 		if (r != bgchild)
 		{
 			fprintf(stderr, _("%s: child %d died, expected %d\n"),
-					progname, r, (int) bgchild);
+					progname, (int) r, (int) bgchild);
 			disconnect_and_exit(1);
 		}
-		if (!WIFEXITED(status))
-		{
-			fprintf(stderr, _("%s: child process did not exit normally\n"),
-					progname);
-			disconnect_and_exit(1);
-		}
-		if (WEXITSTATUS(status) != 0)
+		if (status != 0)
 		{
-			fprintf(stderr, _("%s: child process exited with error %d\n"),
-					progname, WEXITSTATUS(status));
+			fprintf(stderr, "%s: %s\n",
+					progname, wait_result_to_str(status));
 			disconnect_and_exit(1);
 		}
 		/* Exited normally, we're happy! */
diff --git a/src/common/wait_error.c b/src/common/wait_error.c
index 27f5284998..cef36ec01a 100644
--- a/src/common/wait_error.c
+++ b/src/common/wait_error.c
@@ -56,25 +56,17 @@ wait_result_to_str(int exitstatus)
 		}
 	}
 	else if (WIFSIGNALED(exitstatus))
+	{
 #if defined(WIN32)
 		snprintf(str, sizeof(str),
 				 _("child process was terminated by exception 0x%X"),
 				 WTERMSIG(exitstatus));
-#elif defined(HAVE_DECL_SYS_SIGLIST) && HAVE_DECL_SYS_SIGLIST
-	{
-		char		str2[256];
-
-		snprintf(str2, sizeof(str2), "%d: %s", WTERMSIG(exitstatus),
-				 WTERMSIG(exitstatus) < NSIG ?
-				 sys_siglist[WTERMSIG(exitstatus)] : "(unknown)");
-		snprintf(str, sizeof(str),
-				 _("child process was terminated by signal %s"), str2);
-	}
 #else
 		snprintf(str, sizeof(str),
-				 _("child process was terminated by signal %d"),
-				 WTERMSIG(exitstatus));
+				 _("child process was terminated by signal %d: %s"),
+				 WTERMSIG(exitstatus), pg_strsignal(WTERMSIG(exitstatus)));
 #endif
+	}
 	else
 		snprintf(str, sizeof(str),
 				 _("child process exited with unrecognized status %d"),
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index a19f6981d7..a33acbf2d8 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -182,10 +182,6 @@
    don't. */
 #undef HAVE_DECL_STRTOULL
 
-/* Define to 1 if you have the declaration of `sys_siglist', and to 0 if you
-   don't. */
-#undef HAVE_DECL_SYS_SIGLIST
-
 /* Define to 1 if you have the declaration of `vsnprintf', and to 0 if you
    don't. */
 #undef HAVE_DECL_VSNPRINTF
@@ -547,6 +543,9 @@
 /* Define to use have a strong random number source */
 #undef HAVE_STRONG_RANDOM
 
+/* Define to 1 if you have the `strsignal' function. */
+#undef HAVE_STRSIGNAL
+
 /* Define to 1 if you have the `strtoll' function. */
 #undef HAVE_STRTOLL
 
diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32
index 9bc4b3fc0f..e48ded8973 100644
--- a/src/include/pg_config.h.win32
+++ b/src/include/pg_config.h.win32
@@ -414,6 +414,9 @@
 /* Define to use have a strong random number source */
 #define HAVE_STRONG_RANDOM 1
 
+/* Define to 1 if you have the `strsignal' function. */
+/* #undef HAVE_STRSIGNAL */
+
 /* Define to 1 if you have the `strtoll' function. */
 #ifdef HAVE_LONG_LONG_INT_64
 #define HAVE_STRTOLL 1
diff --git a/src/include/port.h b/src/include/port.h
index a9d557b55c..c97d9be250 100644
--- a/src/include/port.h
+++ b/src/include/port.h
@@ -189,6 +189,9 @@ extern int	pg_printf(const char *fmt,...) pg_attribute_printf(1, 2);
 #endif
 #endif							/* USE_REPL_SNPRINTF */
 
+/* Wrap strsignal(), or provide our own version if necessary */
+extern const char *pg_strsignal(int signum);
+
 /* Portable prompt handling */
 extern void simple_prompt(const char *prompt, char *destination, size_t destlen,
 			  bool echo);
diff --git a/src/port/Makefile b/src/port/Makefile
index d7467fb078..ae37898bee 100644
--- a/src/port/Makefile
+++ b/src/port/Makefile
@@ -32,7 +32,7 @@ LIBS += $(PTHREAD_LIBS)
 
 OBJS = $(LIBOBJS) $(PG_CRC32C_OBJS) chklocale.o erand48.o inet_net_ntop.o \
 	noblock.o path.o pgcheckdir.o pgmkdirp.o pgsleep.o \
-	pgstrcasecmp.o pqsignal.o \
+	pgstrcasecmp.o pgstrsignal.o pqsignal.o \
 	qsort.o qsort_arg.o quotes.o sprompt.o tar.o thread.o
 
 ifeq ($(enable_strong_random), yes)
diff --git a/src/port/pgstrsignal.c b/src/port/pgstrsignal.c
new file mode 100644
index 0000000000..7724edf56e
--- /dev/null
+++ b/src/port/pgstrsignal.c
@@ -0,0 +1,64 @@
+/*-------------------------------------------------------------------------
+ *
+ * pgstrsignal.c
+ *	  Identify a Unix signal number
+ *
+ * On platforms compliant with modern POSIX, this just wraps strsignal(3).
+ * Elsewhere, we do the best we can.
+ *
+ * This file is not currently built in MSVC builds, since it's useless
+ * on non-Unix platforms.
+ *
+ * Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  src/port/pgstrsignal.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "c.h"
+
+
+/*
+ * pg_strsignal
+ *
+ * Return a string identifying the given Unix signal number.
+ *
+ * The result is declared "const char *" because callers should not
+ * modify the string.  Note, however, that POSIX does not promise that
+ * the string will remain valid across later calls to strsignal().
+ *
+ * This version guarantees to return a non-NULL pointer, although
+ * some platforms' versions of strsignal() reputedly do not.
+ *
+ * Note that the fallback cases just return constant strings such as
+ * "unrecognized signal".  Project style is for callers to print the
+ * numeric signal value along with the result of this function, so
+ * there's no need to work harder than that.
+ */
+const char *
+pg_strsignal(int signum)
+{
+	const char *result;
+
+	/*
+	 * If we have strsignal(3), use that --- but check its result for NULL.
+	 */
+#ifdef HAVE_STRSIGNAL
+	result = strsignal(signum);
+	if (result == NULL)
+		result = "unrecognized signal";
+#else
+
+	/*
+	 * We used to have code here to try to use sys_siglist[] if available.
+	 * However, it seems that all platforms with sys_siglist[] have also had
+	 * strsignal() for many years now, so that was just a waste of code.
+	 */
+	result = "(signal names not available on this platform)";
+#endif
+
+	return result;
+}
diff --git a/src/test/regress/pg_regress.c b/src/test/regress/pg_regress.c
index 9c6d2efb56..2c469413a3 100644
--- a/src/test/regress/pg_regress.c
+++ b/src/test/regress/pg_regress.c
@@ -1560,14 +1560,9 @@ log_child_failure(int exitstatus)
 #if defined(WIN32)
 		status(_(" (test process was terminated by exception 0x%X)"),
 			   WTERMSIG(exitstatus));
-#elif defined(HAVE_DECL_SYS_SIGLIST) && HAVE_DECL_SYS_SIGLIST
-		status(_(" (test process was terminated by signal %d: %s)"),
-			   WTERMSIG(exitstatus),
-			   WTERMSIG(exitstatus) < NSIG ?
-			   sys_siglist[WTERMSIG(exitstatus)] : "(unknown))");
 #else
-		status(_(" (test process was terminated by signal %d)"),
-			   WTERMSIG(exitstatus));
+		status(_(" (test process was terminated by signal %d: %s)"),
+			   WTERMSIG(exitstatus), pg_strsignal(WTERMSIG(exitstatus)));
 #endif
 	}
 	else