diff --git a/config/c-library.m4 b/config/c-library.m4
index cddeafaec2..0233144321 100644
--- a/config/c-library.m4
+++ b/config/c-library.m4
@@ -30,8 +30,7 @@ fi])# PGAC_VAR_INT_TIMEZONE
 # This is the same as the standard macro AC_STRUCT_TIMEZONE, except that
 # tzname[] is checked for regardless of whether we find tm_zone.
 AC_DEFUN([PGAC_STRUCT_TIMEZONE],
-[AC_REQUIRE([AC_STRUCT_TM])dnl
-AC_CHECK_MEMBERS([struct tm.tm_zone],,,[#include <sys/types.h>
+[AC_CHECK_MEMBERS([struct tm.tm_zone],,,[#include <sys/types.h>
 #include <$ac_cv_struct_tm>
 ])
 if test "$ac_cv_member_struct_tm_tm_zone" = yes; then
@@ -139,7 +138,7 @@ AC_DEFUN([PGAC_UNION_SEMUN],
 # If `struct sockaddr_un' exists, define HAVE_UNIX_SOCKETS.
 # (Requires test for <sys/un.h>!)
 AC_DEFUN([PGAC_STRUCT_SOCKADDR_UN],
-[AC_CHECK_TYPES([struct sockaddr_un], [AC_DEFINE(HAVE_UNIX_SOCKETS, 1, [Define to 1 if you have unix sockets.])], [],
+[AC_CHECK_TYPE([struct sockaddr_un], [AC_DEFINE(HAVE_UNIX_SOCKETS, 1, [Define to 1 if you have unix sockets.])], [],
 [#include <sys/types.h>
 #ifdef HAVE_SYS_UN_H
 #include <sys/un.h>
diff --git a/configure b/configure
index ae34179e0d..99daee9f31 100755
--- a/configure
+++ b/configure
@@ -2795,12 +2795,7 @@ if test "${enable_dtrace+set}" = set; then
   enableval=$enable_dtrace;
   case $enableval in
     yes)
-
-cat >>confdefs.h <<\_ACEOF
-#define ENABLE_DTRACE 1
-_ACEOF
-
-for ac_prog in dtrace
+      for ac_prog in dtrace
 do
   # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
@@ -13002,107 +12997,6 @@ $as_echo "$as_me: error: header file <openssl/err.h> is required for OpenSSL" >&
 fi
 
 
-
-for ac_func in ERR_set_mark
-do
-as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-{ $as_echo "$as_me:$LINENO: checking for $ac_func" >&5
-$as_echo_n "checking for $ac_func... " >&6; }
-if { as_var=$as_ac_var; eval "test \"\${$as_var+set}\" = set"; }; then
-  $as_echo_n "(cached) " >&6
-else
-  cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-/* Define $ac_func to an innocuous variant, in case <limits.h> declares $ac_func.
-   For example, HP-UX 11i <limits.h> declares gettimeofday.  */
-#define $ac_func innocuous_$ac_func
-
-/* System header to define __stub macros and hopefully few prototypes,
-    which can conflict with char $ac_func (); below.
-    Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
-    <limits.h> exists even on freestanding compilers.  */
-
-#ifdef __STDC__
-# include <limits.h>
-#else
-# include <assert.h>
-#endif
-
-#undef $ac_func
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char $ac_func ();
-/* The GNU C library defines this for functions which it implements
-    to always fail with ENOSYS.  Some functions are actually named
-    something starting with __ and the normal name is an alias.  */
-#if defined __stub_$ac_func || defined __stub___$ac_func
-choke me
-#endif
-
-int
-main ()
-{
-return $ac_func ();
-  ;
-  return 0;
-}
-_ACEOF
-rm -f conftest.$ac_objext conftest$ac_exeext
-if { (ac_try="$ac_link"
-case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval ac_try_echo="\"\$as_me:$LINENO: $ac_try_echo\""
-$as_echo "$ac_try_echo") >&5
-  (eval "$ac_link") 2>conftest.er1
-  ac_status=$?
-  grep -v '^ *+' conftest.er1 >conftest.err
-  rm -f conftest.er1
-  cat conftest.err >&5
-  $as_echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); } && {
-	 test -z "$ac_c_werror_flag" ||
-	 test ! -s conftest.err
-       } && test -s conftest$ac_exeext && {
-	 test "$cross_compiling" = yes ||
-	 $as_test_x conftest$ac_exeext
-       }; then
-  eval "$as_ac_var=yes"
-else
-  $as_echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-	eval "$as_ac_var=no"
-fi
-
-rm -rf conftest.dSYM
-rm -f core conftest.err conftest.$ac_objext conftest_ipa8_conftest.oo \
-      conftest$ac_exeext conftest.$ac_ext
-fi
-ac_res=`eval 'as_val=${'$as_ac_var'}
-		 $as_echo "$as_val"'`
-	       { $as_echo "$as_me:$LINENO: result: $ac_res" >&5
-$as_echo "$ac_res" >&6; }
-as_val=`eval 'as_val=${'$as_ac_var'}
-		 $as_echo "$as_val"'`
-   if test "x$as_val" = x""yes; then
-  cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
-_ACEOF
-
-fi
-done
-
 fi
 
 if test "$with_pam" = yes ; then
@@ -15536,68 +15430,6 @@ _ACEOF
 
 fi
 fi
-{ $as_echo "$as_me:$LINENO: checking whether struct tm is in sys/time.h or time.h" >&5
-$as_echo_n "checking whether struct tm is in sys/time.h or time.h... " >&6; }
-if test "${ac_cv_struct_tm+set}" = set; then
-  $as_echo_n "(cached) " >&6
-else
-  cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-#include <sys/types.h>
-#include <time.h>
-
-int
-main ()
-{
-struct tm tm;
-				     int *p = &tm.tm_sec;
-				     return !p;
-  ;
-  return 0;
-}
-_ACEOF
-rm -f conftest.$ac_objext
-if { (ac_try="$ac_compile"
-case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval ac_try_echo="\"\$as_me:$LINENO: $ac_try_echo\""
-$as_echo "$ac_try_echo") >&5
-  (eval "$ac_compile") 2>conftest.er1
-  ac_status=$?
-  grep -v '^ *+' conftest.er1 >conftest.err
-  rm -f conftest.er1
-  cat conftest.err >&5
-  $as_echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); } && {
-	 test -z "$ac_c_werror_flag" ||
-	 test ! -s conftest.err
-       } && test -s conftest.$ac_objext; then
-  ac_cv_struct_tm=time.h
-else
-  $as_echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-	ac_cv_struct_tm=sys/time.h
-fi
-
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-fi
-{ $as_echo "$as_me:$LINENO: result: $ac_cv_struct_tm" >&5
-$as_echo "$ac_cv_struct_tm" >&6; }
-if test $ac_cv_struct_tm = sys/time.h; then
-
-cat >>confdefs.h <<\_ACEOF
-#define TM_IN_SYS_TIME 1
-_ACEOF
-
-fi
-
 { $as_echo "$as_me:$LINENO: checking for struct tm.tm_zone" >&5
 $as_echo_n "checking for struct tm.tm_zone... " >&6; }
 if test "${ac_cv_member_struct_tm_tm_zone+set}" = set; then
@@ -15997,11 +15829,6 @@ fi
 $as_echo "$ac_cv_type_struct_sockaddr_un" >&6; }
 if test "x$ac_cv_type_struct_sockaddr_un" = x""yes; then
 
-cat >>confdefs.h <<_ACEOF
-#define HAVE_STRUCT_SOCKADDR_UN 1
-_ACEOF
-
-
 cat >>confdefs.h <<\_ACEOF
 #define HAVE_UNIX_SOCKETS 1
 _ACEOF
@@ -19260,9 +19087,7 @@ fi
 
 
 
-
-
-for ac_func in cbrt dlopen fcvt fdatasync getifaddrs getpeerucred getrlimit memmove poll pstat readlink setproctitle setsid sigprocmask symlink sysconf towlower utime utimes waitpid wcstombs wcstombs_l
+for ac_func in cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit memmove poll pstat readlink setproctitle setsid sigprocmask symlink towlower utime utimes waitpid wcstombs wcstombs_l
 do
 as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 { $as_echo "$as_me:$LINENO: checking for $ac_func" >&5
diff --git a/configure.in b/configure.in
index d064d5c19e..dfe06cd4cc 100644
--- a/configure.in
+++ b/configure.in
@@ -220,9 +220,7 @@ AC_SUBST(enable_coverage)
 #
 PGAC_ARG_BOOL(enable, dtrace, no,
               [build with DTrace support],
-[AC_DEFINE([ENABLE_DTRACE], 1,
-           [Define to 1 to enable DTrace support. (--enable-dtrace)])
-AC_CHECK_PROGS(DTRACE, dtrace)
+[AC_CHECK_PROGS(DTRACE, dtrace)
 if test -z "$DTRACE"; then
   AC_MSG_ERROR([dtrace not found])
 fi
@@ -1046,7 +1044,6 @@ fi
 if test "$with_openssl" = yes ; then
   AC_CHECK_HEADER(openssl/ssl.h, [], [AC_MSG_ERROR([header file <openssl/ssl.h> is required for OpenSSL])])
   AC_CHECK_HEADER(openssl/err.h, [], [AC_MSG_ERROR([header file <openssl/err.h> is required for OpenSSL])])
-  AC_CHECK_FUNCS([ERR_set_mark])
 fi
 
 if test "$with_pam" = yes ; then
@@ -1200,7 +1197,7 @@ PGAC_VAR_INT_TIMEZONE
 AC_FUNC_ACCEPT_ARGTYPES
 PGAC_FUNC_GETTIMEOFDAY_1ARG
 
-AC_CHECK_FUNCS([cbrt dlopen fcvt fdatasync getifaddrs getpeerucred getrlimit memmove poll pstat readlink setproctitle setsid sigprocmask symlink sysconf towlower utime utimes waitpid wcstombs wcstombs_l])
+AC_CHECK_FUNCS([cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit memmove poll pstat readlink setproctitle setsid sigprocmask symlink towlower utime utimes waitpid wcstombs wcstombs_l])
 
 AC_REPLACE_FUNCS(fseeko)
 case $host_os in
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index fa9ebde14e..0aa457214b 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -48,9 +48,6 @@
 /* Define to the default TCP port number as a string constant. */
 #undef DEF_PGPORT_STR
 
-/* Define to 1 to enable DTrace support. (--enable-dtrace) */
-#undef ENABLE_DTRACE
-
 /* Define to build with GSSAPI support. (--with-gssapi) */
 #undef ENABLE_GSS
 
@@ -149,12 +146,6 @@
 /* Define to 1 if you have the <editline/readline.h> header file. */
 #undef HAVE_EDITLINE_READLINE_H
 
-/* Define to 1 if you have the `ERR_set_mark' function. */
-#undef HAVE_ERR_SET_MARK
-
-/* Define to 1 if you have the `fcvt' function. */
-#undef HAVE_FCVT
-
 /* Define to 1 if you have the `fdatasync' function. */
 #undef HAVE_FDATASYNC
 
@@ -514,18 +505,12 @@
 /* Define to 1 if `__ss_len' is member of `struct sockaddr_storage'. */
 #undef HAVE_STRUCT_SOCKADDR_STORAGE___SS_LEN
 
-/* Define to 1 if the system has the type `struct sockaddr_un'. */
-#undef HAVE_STRUCT_SOCKADDR_UN
-
 /* Define to 1 if `tm_zone' is member of `struct tm'. */
 #undef HAVE_STRUCT_TM_TM_ZONE
 
 /* Define to 1 if you have the `symlink' function. */
 #undef HAVE_SYMLINK
 
-/* Define to 1 if you have the `sysconf' function. */
-#undef HAVE_SYSCONF
-
 /* Define to 1 if you have the syslog interface. */
 #undef HAVE_SYSLOG
 
@@ -735,9 +720,6 @@
 /* Define to 1 if strerror_r() returns a int. */
 #undef STRERROR_R_INT
 
-/* Define to 1 if your <sys/time.h> declares `struct tm'. */
-#undef TM_IN_SYS_TIME
-
 /* Define to the appropriate snprintf format for unsigned 64-bit ints. */
 #undef UINT64_FORMAT