Remove dead setenv, unsetenv replacement code.

setenv() and unsetenv() are in SUSv3 and targeted Unix systems have
them.  We still need special code for these on Windows, but that doesn't
require a configure probe.

This marks the first time we require a SUSv3 (POSIX.1-2001) facility
(rather than SUSv2).  The replacement code removed here was not needed
on any targeted system or any known non-EOL'd Unix system, and was
therefore dead and untested.

No need for vestigial HAVE_SETENV and HAVE_UNSETENV macros, because we
provide a replacement for Windows, and we didn't previously test the
macros.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Greg Stark <stark@mit.edu>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CA+hUKGJ3LHeP9w5Fgzdr4G8AnEtJ=z=p6hGDEm4qYGEUX5B6fQ@mail.gmail.com

5 files changed, 0 insertions, 129 deletions

diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index f3f132e2058..b6ee575681c 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -448,9 +448,6 @@
 /* Define to 1 if you have the <security/pam_appl.h> header file. */
 #undef HAVE_SECURITY_PAM_APPL_H
 
-/* Define to 1 if you have the `setenv' function. */
-#undef HAVE_SETENV
-
 /* Define to 1 if you have the `setproctitle' function. */
 #undef HAVE_SETPROCTITLE
 
@@ -625,9 +622,6 @@
 /* Define to 1 if you have the <unistd.h> header file. */
 #undef HAVE_UNISTD_H
 
-/* Define to 1 if you have the `unsetenv' function. */
-#undef HAVE_UNSETENV
-
 /* Define to 1 if you have the `uselocale' function. */
 #undef HAVE_USELOCALE
 
diff --git a/src/include/port.h b/src/include/port.h
index cec785f8a5d..85c9b38f4ee 100644
--- a/src/include/port.h
+++ b/src/include/port.h
@@ -448,14 +448,6 @@ extern size_t strlcpy(char *dst, const char *src, size_t siz);
 extern size_t strnlen(const char *str, size_t maxlen);
 #endif
 
-#ifndef HAVE_SETENV
-extern int	setenv(const char *name, const char *value, int overwrite);
-#endif
-
-#ifndef HAVE_UNSETENV
-extern int	unsetenv(const char *name);
-#endif
-
 /* thread.c */
 #ifndef WIN32
 extern bool pg_get_user_name(uid_t user_id, char *buffer, size_t buflen);
diff --git a/src/port/setenv.c b/src/port/setenv.c
deleted file mode 100644
index d13c8824671..00000000000
--- a/src/port/setenv.c
+++ /dev/null
@@ -1,48 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * setenv.c
- *	  setenv() emulation for machines without it
- *
- * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- *
- * IDENTIFICATION
- *	  src/port/setenv.c
- *
- *-------------------------------------------------------------------------
- */
-
-#include "c.h"
-
-
-int
-setenv(const char *name, const char *value, int overwrite)
-{
-	char	   *envstr;
-
-	/* Error conditions, per POSIX */
-	if (name == NULL || name[0] == '\0' || strchr(name, '=') != NULL ||
-		value == NULL)
-	{
-		errno = EINVAL;
-		return -1;
-	}
-
-	/* No work if variable exists and we're not to replace it */
-	if (overwrite == 0 && getenv(name) != NULL)
-		return 0;
-
-	/*
-	 * Add or replace the value using putenv().  This will leak memory if the
-	 * same variable is repeatedly redefined, but there's little we can do
-	 * about that when sitting atop putenv().
-	 */
-	envstr = (char *) malloc(strlen(name) + strlen(value) + 2);
-	if (!envstr)				/* not much we can do if no memory */
-		return -1;
-
-	sprintf(envstr, "%s=%s", name, value);
-
-	return putenv(envstr);
-}
diff --git a/src/port/unsetenv.c b/src/port/unsetenv.c
deleted file mode 100644
index 62b806d796c..00000000000
--- a/src/port/unsetenv.c
+++ /dev/null
@@ -1,65 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * unsetenv.c
- *	  unsetenv() emulation for machines without it
- *
- * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- *
- * IDENTIFICATION
- *	  src/port/unsetenv.c
- *
- *-------------------------------------------------------------------------
- */
-
-#include "c.h"
-
-
-int
-unsetenv(const char *name)
-{
-	char	   *envstr;
-
-	/* Error conditions, per POSIX */
-	if (name == NULL || name[0] == '\0' || strchr(name, '=') != NULL)
-	{
-		errno = EINVAL;
-		return -1;
-	}
-
-	if (getenv(name) == NULL)
-		return 0;				/* no work */
-
-	/*
-	 * The technique embodied here works if libc follows the Single Unix Spec
-	 * and actually uses the storage passed to putenv() to hold the environ
-	 * entry.  When we clobber the entry in the second step we are ensuring
-	 * that we zap the actual environ member.  However, there are some libc
-	 * implementations (notably recent BSDs) that do not obey SUS but copy the
-	 * presented string.  This method fails on such platforms.  Hopefully all
-	 * such platforms have unsetenv() and thus won't be using this hack. See:
-	 * http://www.greenend.org.uk/rjk/2008/putenv.html
-	 *
-	 * Note that repeatedly setting and unsetting a var using this code will
-	 * leak memory.
-	 */
-
-	envstr = (char *) malloc(strlen(name) + 2);
-	if (!envstr)				/* not much we can do if no memory */
-		return -1;
-
-	/* Override the existing setting by forcibly defining the var */
-	sprintf(envstr, "%s=", name);
-	if (putenv(envstr))
-		return -1;
-
-	/* Now we can clobber the variable definition this way: */
-	strcpy(envstr, "=");
-
-	/*
-	 * This last putenv cleans up if we have multiple zero-length names as a
-	 * result of unsetting multiple things.
-	 */
-	return putenv(envstr);
-}
diff --git a/src/tools/msvc/Solution.pm b/src/tools/msvc/Solution.pm
index 2a7d9f1f9ef..5301e01e833 100644
--- a/src/tools/msvc/Solution.pm
+++ b/src/tools/msvc/Solution.pm
@@ -343,7 +343,6 @@ sub GenerateFiles
 		HAVE_RL_RESET_SCREEN_SIZE                => undef,
 		HAVE_RL_VARIABLE_BIND                    => undef,
 		HAVE_SECURITY_PAM_APPL_H                 => undef,
-		HAVE_SETENV                              => undef,
 		HAVE_SETPROCTITLE                        => undef,
 		HAVE_SETPROCTITLE_FAST                   => undef,
 		HAVE_SOCKLEN_T                           => 1,
@@ -402,7 +401,6 @@ sub GenerateFiles
 		HAVE_UINT8                               => undef,
 		HAVE_UNION_SEMUN                         => undef,
 		HAVE_UNISTD_H                            => 1,
-		HAVE_UNSETENV                            => undef,
 		HAVE_USELOCALE                           => undef,
 		HAVE_UUID_BSD                            => undef,
 		HAVE_UUID_E2FS                           => undef,