Revert back to standard AC_STRUCT_TIMEZONE Autoconf macro

From 78597561e3f8e9119d6fd07e4106cc780e58507b Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Mon, 30 Sep 2019 20:50:16 +0200
Subject: [PATCH 1/2] Remove use of deprecated Autoconf define

Change from HAVE_TM_ZONE to HAVE_STRUCT_TM_TM_ZONE.
---
 src/interfaces/ecpg/pgtypeslib/dt_common.c | 4 ++--
 src/interfaces/ecpg/pgtypeslib/timestamp.c | 8 ++++----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/interfaces/ecpg/pgtypeslib/dt_common.c b/src/interfaces/ecpg/pgtypeslib/dt_common.c
index e71defaa66..29c1117546 100644
--- a/src/interfaces/ecpg/pgtypeslib/dt_common.c
+++ b/src/interfaces/ecpg/pgtypeslib/dt_common.c
@@ -995,7 +995,7 @@ abstime2tm(AbsoluteTime _time, int *tzp, struct tm *tm, char **tzn)
 	tm->tm_sec = tx->tm_sec;
 	tm->tm_isdst = tx->tm_isdst;
 
-#if defined(HAVE_TM_ZONE)
+#if defined(HAVE_STRUCT_TM_TM_ZONE)
 	tm->tm_gmtoff = tx->tm_gmtoff;
 	tm->tm_zone = tx->tm_zone;
 
@@ -1041,7 +1041,7 @@ abstime2tm(AbsoluteTime _time, int *tzp, struct tm *tm, char **tzn)
 	}
 	else
 		tm->tm_isdst = -1;
-#else							/* not (HAVE_TM_ZONE || HAVE_INT_TIMEZONE) */
+#else							/* not (HAVE_STRUCT_TM_TM_ZONE || HAVE_INT_TIMEZONE) */
 	if (tzp != NULL)
 	{
 		/* default to UTC */
diff --git a/src/interfaces/ecpg/pgtypeslib/timestamp.c b/src/interfaces/ecpg/pgtypeslib/timestamp.c
index e830ee737e..2be151f7e6 100644
--- a/src/interfaces/ecpg/pgtypeslib/timestamp.c
+++ b/src/interfaces/ecpg/pgtypeslib/timestamp.c
@@ -100,7 +100,7 @@ timestamp2tm(timestamp dt, int *tzp, struct tm *tm, fsec_t *fsec, const char **t
 	int64		dDate,
 				date0;
 	int64		time;
-#if defined(HAVE_TM_ZONE) || defined(HAVE_INT_TIMEZONE)
+#if defined(HAVE_STRUCT_TM_TM_ZONE) || defined(HAVE_INT_TIMEZONE)
 	time_t		utime;
 	struct tm  *tx;
 #endif
@@ -134,7 +134,7 @@ timestamp2tm(timestamp dt, int *tzp, struct tm *tm, fsec_t *fsec, const char **t
 		 */
 		if (IS_VALID_UTIME(tm->tm_year, tm->tm_mon, tm->tm_mday))
 		{
-#if defined(HAVE_TM_ZONE) || defined(HAVE_INT_TIMEZONE)
+#if defined(HAVE_STRUCT_TM_TM_ZONE) || defined(HAVE_INT_TIMEZONE)
 
 			utime = dt / USECS_PER_SEC +
 				((date0 - date2j(1970, 1, 1)) * INT64CONST(86400));
@@ -147,7 +147,7 @@ timestamp2tm(timestamp dt, int *tzp, struct tm *tm, fsec_t *fsec, const char **t
 			tm->tm_min = tx->tm_min;
 			tm->tm_isdst = tx->tm_isdst;
 
-#if defined(HAVE_TM_ZONE)
+#if defined(HAVE_STRUCT_TM_TM_ZONE)
 			tm->tm_gmtoff = tx->tm_gmtoff;
 			tm->tm_zone = tx->tm_zone;
 
@@ -159,7 +159,7 @@ timestamp2tm(timestamp dt, int *tzp, struct tm *tm, fsec_t *fsec, const char **t
 			if (tzn != NULL)
 				*tzn = TZNAME_GLOBAL[(tm->tm_isdst > 0)];
 #endif
-#else							/* not (HAVE_TM_ZONE || HAVE_INT_TIMEZONE) */
+#else							/* not (HAVE_STRUCT_TM_TM_ZONE || HAVE_INT_TIMEZONE) */
 			*tzp = 0;
 			/* Mark this as *no* time zone available */
 			tm->tm_isdst = -1;
-- 
2.23.0

From 5fb3fb899b74f9eb8ba63c23da8a65582b5b2eb0 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Mon, 30 Sep 2019 21:12:58 +0200
Subject: [PATCH 2/2] Revert back to standard AC_STRUCT_TIMEZONE Autoconf macro

We used to use our own variant of this called PGAC_STRUCT_TIMEZONE
that checked for tzname even if other variants were found first.  But
since 63bd0db12199c5df043e1dea0f2b574f622b3a4c we don't use tzname
anymore, so we don't need this anymore.
---
 config/c-library.m4        |  33 ----
 configure                  | 300 +++++++++++++++++++------------------
 configure.in               |   2 +-
 src/include/pg_config.h.in |   7 +-
 4 files changed, 163 insertions(+), 179 deletions(-)

diff --git a/config/c-library.m4 b/config/c-library.m4
index 6f2b0fbb4e..a8fa6edd26 100644
--- a/config/c-library.m4
+++ b/config/c-library.m4
@@ -23,39 +23,6 @@ if test x"$pgac_cv_var_int_timezone" = xyes ; then
 fi])# PGAC_VAR_INT_TIMEZONE
 
 
-# PGAC_STRUCT_TIMEZONE
-# ------------------
-# Figure out how to get the current timezone.  If `struct tm' has a
-# `tm_zone' member, define `HAVE_TM_ZONE'.  Also, if the
-# external array `tzname' is found, define `HAVE_TZNAME'.
-# 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>
-#include <$ac_cv_struct_tm>
-])
-if test "$ac_cv_member_struct_tm_tm_zone" = yes; then
-  AC_DEFINE(HAVE_TM_ZONE, 1,
-            [Define to 1 if your `struct tm' has `tm_zone'. Deprecated, use
-             `HAVE_STRUCT_TM_TM_ZONE' instead.])
-fi
-AC_CACHE_CHECK(for tzname, ac_cv_var_tzname,
-[AC_LINK_IFELSE([AC_LANG_PROGRAM(
-[[#include <stdlib.h>
-#include <time.h>
-#ifndef tzname /* For SGI.  */
-extern char *tzname[]; /* RS6000 and others reject char **tzname.  */
-#endif
-]],
-[atoi(*tzname);])], ac_cv_var_tzname=yes, ac_cv_var_tzname=no)])
-if test $ac_cv_var_tzname = yes; then
-    AC_DEFINE(HAVE_TZNAME, 1,
-              [Define to 1 if you have the external array `tzname'.])
-fi
-])# PGAC_STRUCT_TIMEZONE
-
-
 # PGAC_FUNC_GETTIMEOFDAY_1ARG
 # ---------------------------
 # Check if gettimeofday() has only one arguments. (Normal is two.)
diff --git a/configure b/configure
index b3c92764be..8c399bda7c 100755
--- a/configure
+++ b/configure
@@ -2182,6 +2182,56 @@ $as_echo "$ac_res" >&6; }
 
 } # ac_fn_c_check_member
 
+# ac_fn_c_check_decl LINENO SYMBOL VAR INCLUDES
+# ---------------------------------------------
+# Tests whether SYMBOL is declared in INCLUDES, setting cache variable VAR
+# accordingly.
+ac_fn_c_check_decl ()
+{
+  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
+  # Initialize each $ac_[]_AC_LANG_ABBREV[]_decl_warn_flag once.
+      as_decl_name=`echo $2|sed 's/ *(.*//'`
+  as_decl_use=`echo $2|sed -e 's/(/((/' -e 's/)/) 0&/' -e 's/,/) 0& (/g'`
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $as_decl_name is declared" >&5
+$as_echo_n "checking whether $as_decl_name is declared... " >&6; }
+if eval \${$3+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_save_werror_flag=$ac_c_werror_flag
+  ac_c_werror_flag="$ac_c_decl_warn_flag$ac_c_werror_flag"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$4
+int
+main ()
+{
+#ifndef $as_decl_name
+#ifdef __cplusplus
+  (void) $as_decl_use;
+#else
+  (void) $as_decl_name;
+#endif
+#endif
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  eval "$3=yes"
+else
+  eval "$3=no"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  ac_c_werror_flag=$ac_save_werror_flag
+fi
+eval ac_res=\$$3
+	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
+
+} # ac_fn_c_check_decl
+
 # ac_fn_c_compute_int LINENO EXPR VAR INCLUDES
 # --------------------------------------------
 # Tries to find the compile-time value of EXPR in a program that includes
@@ -2364,56 +2414,6 @@ rm -f conftest.val
   as_fn_set_status $ac_retval
 
 } # ac_fn_c_compute_int
-
-# ac_fn_c_check_decl LINENO SYMBOL VAR INCLUDES
-# ---------------------------------------------
-# Tests whether SYMBOL is declared in INCLUDES, setting cache variable VAR
-# accordingly.
-ac_fn_c_check_decl ()
-{
-  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
-  # Initialize each $ac_[]_AC_LANG_ABBREV[]_decl_warn_flag once.
-      as_decl_name=`echo $2|sed 's/ *(.*//'`
-  as_decl_use=`echo $2|sed -e 's/(/((/' -e 's/)/) 0&/' -e 's/,/) 0& (/g'`
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $as_decl_name is declared" >&5
-$as_echo_n "checking whether $as_decl_name is declared... " >&6; }
-if eval \${$3+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_save_werror_flag=$ac_c_werror_flag
-  ac_c_werror_flag="$ac_c_decl_warn_flag$ac_c_werror_flag"
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-$4
-int
-main ()
-{
-#ifndef $as_decl_name
-#ifdef __cplusplus
-  (void) $as_decl_use;
-#else
-  (void) $as_decl_name;
-#endif
-#endif
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  eval "$3=yes"
-else
-  eval "$3=no"
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-  ac_c_werror_flag=$ac_save_werror_flag
-fi
-eval ac_res=\$$3
-	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
-$as_echo "$ac_res" >&6; }
-  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
-
-} # ac_fn_c_check_decl
 cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
@@ -13999,6 +13999,94 @@ $as_echo "#define TM_IN_SYS_TIME 1" >>confdefs.h
 
 fi
 
+# The Clang compiler raises a warning for an undeclared identifier that matches
+# a compiler builtin function.  All extant Clang versions are affected, as of
+# Clang 3.6.0.  Test a builtin known to every version.  This problem affects the
+# C and Objective C languages, but Clang does report an error under C++ and
+# Objective C++.
+#
+# Passing -fno-builtin to the compiler would suppress this problem.  That
+# strategy would have the advantage of being insensitive to stray warnings, but
+# it would make tests less realistic.
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking how $CC reports undeclared, standard C functions" >&5
+$as_echo_n "checking how $CC reports undeclared, standard C functions... " >&6; }
+if ${ac_cv_c_decl_report+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+(void) strchr;
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  if test -s conftest.err; then :
+      # For AC_CHECK_DECL to react to warnings, the compiler must be silent on
+    # valid AC_CHECK_DECL input.  No library function is consistently available
+    # on freestanding implementations, so test against a dummy declaration.
+    # Include always-available headers on the off chance that they somehow
+    # elicit warnings.
+    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <float.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stddef.h>
+extern void ac_decl (int, char *);
+int
+main ()
+{
+#ifdef __cplusplus
+  (void) ac_decl ((int) 0, (char *) 0);
+  (void) ac_decl;
+#else
+  (void) ac_decl;
+#endif
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  if test -s conftest.err; then :
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error $? "cannot detect from compiler exit status or warnings
+See \`config.log' for more details" "$LINENO" 5; }
+else
+  ac_cv_c_decl_report=warning
+fi
+else
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error $? "cannot compile a simple declaration test
+See \`config.log' for more details" "$LINENO" 5; }
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+else
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error $? "compiler does not report undeclared identifiers
+See \`config.log' for more details" "$LINENO" 5; }
+fi
+else
+  ac_cv_c_decl_report=error
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_c_decl_report" >&5
+$as_echo "$ac_cv_c_decl_report" >&6; }
+
+case $ac_cv_c_decl_report in
+  warning) ac_c_decl_warn_flag=yes ;;
+  *) ac_c_decl_warn_flag= ;;
+esac
+
 ac_fn_c_check_member "$LINENO" "struct tm" "tm_zone" "ac_cv_member_struct_tm_tm_zone" "#include <sys/types.h>
 #include <$ac_cv_struct_tm>
 
@@ -14016,24 +14104,35 @@ if test "$ac_cv_member_struct_tm_tm_zone" = yes; then
 
 $as_echo "#define HAVE_TM_ZONE 1" >>confdefs.h
 
+else
+  ac_fn_c_check_decl "$LINENO" "tzname" "ac_cv_have_decl_tzname" "#include <time.h>
+"
+if test "x$ac_cv_have_decl_tzname" = xyes; then :
+  ac_have_decl=1
+else
+  ac_have_decl=0
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for tzname" >&5
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_DECL_TZNAME $ac_have_decl
+_ACEOF
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for tzname" >&5
 $as_echo_n "checking for tzname... " >&6; }
 if ${ac_cv_var_tzname+:} false; then :
   $as_echo_n "(cached) " >&6
 else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
-#include <stdlib.h>
 #include <time.h>
-#ifndef tzname /* For SGI.  */
-extern char *tzname[]; /* RS6000 and others reject char **tzname.  */
+#if !HAVE_DECL_TZNAME
+extern char *tzname[];
 #endif
 
 int
 main ()
 {
-atoi(*tzname);
+return tzname[0][0];
   ;
   return 0;
 }
@@ -14048,10 +14147,11 @@ rm -f core conftest.err conftest.$ac_objext \
 fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_var_tzname" >&5
 $as_echo "$ac_cv_var_tzname" >&6; }
-if test $ac_cv_var_tzname = yes; then
+  if test $ac_cv_var_tzname = yes; then
 
 $as_echo "#define HAVE_TZNAME 1" >>confdefs.h
 
+  fi
 fi
 
 ac_fn_c_check_type "$LINENO" "union semun" "ac_cv_type_union_semun" "#include <sys/types.h>
@@ -15427,94 +15527,6 @@ esac
 # posix_fadvise() is a no-op on Solaris, so don't incur function overhead
 # by calling it, 2009-04-02
 # http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/lib/libc/port/gen/posix_fadvise.c
-# The Clang compiler raises a warning for an undeclared identifier that matches
-# a compiler builtin function.  All extant Clang versions are affected, as of
-# Clang 3.6.0.  Test a builtin known to every version.  This problem affects the
-# C and Objective C languages, but Clang does report an error under C++ and
-# Objective C++.
-#
-# Passing -fno-builtin to the compiler would suppress this problem.  That
-# strategy would have the advantage of being insensitive to stray warnings, but
-# it would make tests less realistic.
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking how $CC reports undeclared, standard C functions" >&5
-$as_echo_n "checking how $CC reports undeclared, standard C functions... " >&6; }
-if ${ac_cv_c_decl_report+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main ()
-{
-(void) strchr;
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  if test -s conftest.err; then :
-      # For AC_CHECK_DECL to react to warnings, the compiler must be silent on
-    # valid AC_CHECK_DECL input.  No library function is consistently available
-    # on freestanding implementations, so test against a dummy declaration.
-    # Include always-available headers on the off chance that they somehow
-    # elicit warnings.
-    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <float.h>
-#include <limits.h>
-#include <stdarg.h>
-#include <stddef.h>
-extern void ac_decl (int, char *);
-int
-main ()
-{
-#ifdef __cplusplus
-  (void) ac_decl ((int) 0, (char *) 0);
-  (void) ac_decl;
-#else
-  (void) ac_decl;
-#endif
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  if test -s conftest.err; then :
-  { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
-$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
-as_fn_error $? "cannot detect from compiler exit status or warnings
-See \`config.log' for more details" "$LINENO" 5; }
-else
-  ac_cv_c_decl_report=warning
-fi
-else
-  { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
-$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
-as_fn_error $? "cannot compile a simple declaration test
-See \`config.log' for more details" "$LINENO" 5; }
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-else
-  { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
-$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
-as_fn_error $? "compiler does not report undeclared identifiers
-See \`config.log' for more details" "$LINENO" 5; }
-fi
-else
-  ac_cv_c_decl_report=error
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_c_decl_report" >&5
-$as_echo "$ac_cv_c_decl_report" >&6; }
-
-case $ac_cv_c_decl_report in
-  warning) ac_c_decl_warn_flag=yes ;;
-  *) ac_c_decl_warn_flag= ;;
-esac
-
 if test "$PORTNAME" != "solaris"; then :
 
 for ac_func in posix_fadvise
diff --git a/configure.in b/configure.in
index 0d16c1a971..d55b67b984 100644
--- a/configure.in
+++ b/configure.in
@@ -1462,7 +1462,7 @@ PGAC_C_TYPES_COMPATIBLE
 PGAC_C_BUILTIN_CONSTANT_P
 PGAC_C_BUILTIN_UNREACHABLE
 PGAC_C_COMPUTED_GOTO
-PGAC_STRUCT_TIMEZONE
+AC_STRUCT_TIMEZONE
 PGAC_UNION_SEMUN
 PGAC_STRUCT_SOCKADDR_UN
 PGAC_STRUCT_SOCKADDR_STORAGE
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index c6014e83fa..ece6a5def7 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -186,6 +186,10 @@
    don't. */
 #undef HAVE_DECL_STRTOULL
 
+/* Define to 1 if you have the declaration of `tzname', and to 0 if you don't.
+   */
+#undef HAVE_DECL_TZNAME
+
 /* Define to 1 if you have the `dlopen' function. */
 #undef HAVE_DLOPEN
 
@@ -661,7 +665,8 @@
 /* Define to 1 if your compiler understands `typeof' or something similar. */
 #undef HAVE_TYPEOF
 
-/* Define to 1 if you have the external array `tzname'. */
+/* Define to 1 if you don't have `tm_zone' but do have the external array
+   `tzname'. */
 #undef HAVE_TZNAME
 
 /* Define to 1 if you have the <ucred.h> header file. */
-- 
2.23.0