Remove obsolete platforms from ps_status.c.

Time to remove various code, comments and configure/meson probes
relating to ancient BSD, SunOS, GNU/Hurd, IRIX, NeXT and Unixware.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CA%2BhUKGJMNGUAqf27WbckYFrM-Mavy0RKJvocfJU%3DJ2XcAZyv%2Bw%40mail.gmail.com

configure

@@ -16278,41 +16278,6 @@ cat >>confdefs.h <<_ACEOF
 _ACEOF
 
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for PS_STRINGS" >&5
-$as_echo_n "checking for PS_STRINGS... " >&6; }
-if ${pgac_cv_var_PS_STRINGS+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <machine/vmparam.h>
-#include <sys/exec.h>
-
-int
-main ()
-{
-PS_STRINGS->ps_nargvstr = 1;
-PS_STRINGS->ps_argvstr = "foo";
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  pgac_cv_var_PS_STRINGS=yes
-else
-  pgac_cv_var_PS_STRINGS=no
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_var_PS_STRINGS" >&5
-$as_echo "$pgac_cv_var_PS_STRINGS" >&6; }
-if test "$pgac_cv_var_PS_STRINGS" = yes ; then
-
-$as_echo "#define HAVE_PS_STRINGS 1" >>confdefs.h
-
-fi
-
 ac_fn_c_check_func "$LINENO" "explicit_bzero" "ac_cv_func_explicit_bzero"
 if test "x$ac_cv_func_explicit_bzero" = xyes; then :
   $as_echo "#define HAVE_EXPLICIT_BZERO 1" >>confdefs.h

configure.ac

@@ -1849,19 +1849,6 @@ AC_CHECK_DECLS([pwritev], [], [AC_LIBOBJ(pwritev)], [#include <sys/uio.h>])
 # This is probably only present on macOS, but may as well check always
 AC_CHECK_DECLS(F_FULLFSYNC, [], [], [#include <fcntl.h>])
 
-AC_CACHE_CHECK([for PS_STRINGS], [pgac_cv_var_PS_STRINGS],
-[AC_LINK_IFELSE([AC_LANG_PROGRAM(
-[#include <machine/vmparam.h>
-#include <sys/exec.h>
-],
-[PS_STRINGS->ps_nargvstr = 1;
-PS_STRINGS->ps_argvstr = "foo";])],
-[pgac_cv_var_PS_STRINGS=yes],
-[pgac_cv_var_PS_STRINGS=no])])
-if test "$pgac_cv_var_PS_STRINGS" = yes ; then
-  AC_DEFINE([HAVE_PS_STRINGS], 1, [Define to 1 if the PS_STRINGS thing exists.])
-fi
-
 AC_REPLACE_FUNCS(m4_normalize([
 	explicit_bzero
 	getopt

meson.build

@@ -2293,23 +2293,6 @@ endif
 cdata.set('pg_restrict', '__restrict')
 
 
-if cc.links('''
-#include <machine/vmparam.h>
-#include <sys/exec.h>
-
-int main(void)
-{
-    PS_STRINGS->ps_nargvstr = 1;
-    PS_STRINGS->ps_argvstr = "foo";
-}
-''',
-  name: 'PS_STRINGS', args: test_c_args)
-  cdata.set('HAVE_PS_STRINGS', 1)
-else
-  cdata.set('HAVE_PS_STRINGS', false)
-endif
-
-
 # Most libraries are included only if they demonstrably provide a function we
 # need, but libm is an exception: always include it, because there are too
 # many compilers that play cute optimization games that will break probes for

src/backend/utils/misc/ps_status.c

@@ -15,10 +15,6 @@
 #include "postgres.h"
 
 #include <unistd.h>
-#ifdef HAVE_PS_STRINGS
-#include <machine/vmparam.h>	/* for old BSD */
-#include <sys/exec.h>
-#endif
 #if defined(__darwin__)
 #include <crt_externs.h>
 #endif
@@ -39,16 +35,10 @@ bool		update_process_title = DEFAULT_UPDATE_PROCESS_TITLE;
  *
  * PS_USE_SETPROCTITLE_FAST
  *	   use the function setproctitle_fast(const char *, ...)
- *	   (newer FreeBSD systems)
+ *	   (FreeBSD)
  * PS_USE_SETPROCTITLE
  *	   use the function setproctitle(const char *, ...)
- *	   (newer BSD systems)
+ *	   (other BSDs)
- * PS_USE_PS_STRINGS
- *	   assign PS_STRINGS->ps_argvstr = "string"
- *	   (some BSD systems)
- * PS_USE_CHANGE_ARGV
- *	   assign argv[0] = "string"
- *	   (some other BSD systems)
  * PS_USE_CLOBBER_ARGV
  *	   write over the argv and environment area
  *	   (Linux and most SysV-like systems)
@@ -62,11 +52,7 @@ bool		update_process_title = DEFAULT_UPDATE_PROCESS_TITLE;
 #define PS_USE_SETPROCTITLE_FAST
 #elif defined(HAVE_SETPROCTITLE)
 #define PS_USE_SETPROCTITLE
-#elif defined(HAVE_PS_STRINGS)
+#elif defined(__linux__) || defined(_AIX) || defined(__sun) || defined(__darwin__)
-#define PS_USE_PS_STRINGS
-#elif (defined(BSD) || defined(__hurd__)) && !defined(__darwin__)
-#define PS_USE_CHANGE_ARGV
-#elif defined(__linux__) || defined(_AIX) || defined(__sgi) || (defined(sun) && !defined(BSD)) || defined(__svr5__) || defined(__darwin__)
 #define PS_USE_CLOBBER_ARGV
 #elif defined(WIN32)
 #define PS_USE_WIN32
@@ -186,9 +172,6 @@ save_ps_display_args(int argc, char **argv)
 		new_environ[i] = NULL;
 		environ = new_environ;
 	}
-#endif							/* PS_USE_CLOBBER_ARGV */
-
-#if defined(PS_USE_CHANGE_ARGV) || defined(PS_USE_CLOBBER_ARGV)
 
 	/*
 	 * If we're going to change the original argv[] then make a copy for
@@ -226,15 +209,15 @@ save_ps_display_args(int argc, char **argv)
 #if defined(__darwin__)
 
 		/*
-		 * macOS (and perhaps other NeXT-derived platforms?) has a static copy
+		 * macOS has a static copy of the argv pointer, which we may fix like
-		 * of the argv pointer, which we may fix like so:
+		 * so:
 		 */
 		*_NSGetArgv() = new_argv;
 #endif
 
 		argv = new_argv;
 	}
-#endif							/* PS_USE_CHANGE_ARGV or PS_USE_CLOBBER_ARGV */
+#endif							/* PS_USE_CLOBBER_ARGV */
 
 	return argv;
 }
@@ -271,25 +254,10 @@ init_ps_display(const char *fixed_part)
 	/* If ps_buffer is a pointer, it might still be null */
 	if (!ps_buffer)
 		return;
-#endif
 
-	/*
+	/* make extra argv slots point at end_of_area (a NUL) */
-	 * Overwrite argv[] to point at appropriate space, if needed
+	for (int i = 1; i < save_argc; i++)
-	 */
+		save_argv[i] = ps_buffer + ps_buffer_size;
-
-#ifdef PS_USE_CHANGE_ARGV
-	save_argv[0] = ps_buffer;
-	save_argv[1] = NULL;
-#endif							/* PS_USE_CHANGE_ARGV */
-
-#ifdef PS_USE_CLOBBER_ARGV
-	{
-		int			i;
-
-		/* make extra argv slots point at end_of_area (a NUL) */
-		for (i = 1; i < save_argc; i++)
-			save_argv[i] = ps_buffer + ps_buffer_size;
-	}
 #endif							/* PS_USE_CLOBBER_ARGV */
 
 	/*
@@ -369,11 +337,6 @@ set_ps_display(const char *activity)
 	setproctitle_fast("%s", ps_buffer);
 #endif
 
-#ifdef PS_USE_PS_STRINGS
-	PS_STRINGS->ps_nargvstr = 1;
-	PS_STRINGS->ps_argvstr = ps_buffer;
-#endif							/* PS_USE_PS_STRINGS */
-
 #ifdef PS_USE_CLOBBER_ARGV
 	/* pad unused memory; need only clobber remainder of old status string */
 	if (last_status_len > ps_buffer_cur_len)

src/include/pg_config.h.in

@@ -334,9 +334,6 @@
 /* Define to 1 if you have the `ppoll' function. */
 #undef HAVE_PPOLL
 
-/* Define to 1 if the PS_STRINGS thing exists. */
-#undef HAVE_PS_STRINGS
-
 /* Define if you have POSIX threads libraries and header files. */
 #undef HAVE_PTHREAD
 

src/tools/msvc/Solution.pm

@@ -308,7 +308,6 @@ sub GenerateFiles
 		HAVE_POSIX_FADVISE          => undef,
 		HAVE_POSIX_FALLOCATE        => undef,
 		HAVE_PPOLL                  => undef,
-		HAVE_PS_STRINGS             => undef,
 		HAVE_PTHREAD                => undef,
 		HAVE_PTHREAD_BARRIER_WAIT   => undef,
 		HAVE_PTHREAD_IS_THREADED_NP => undef,