From 27acbd51e60c98cba6441d7a88210a1c33bf9db4 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Tue, 8 Sep 2020 10:09:43 +0200
Subject: [PATCH] Use return instead of exit() in configure

Using exit() requires stdlib.h, which is not included.  Use return
instead.  Also add return type for main().

Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: Thomas Munro <thomas.munro@enterprisedb.com>

Backpatched because Apple macOS 10.16/11 (Big Sur) compiler makes
calling undeclared functions an error, so these configure tests would
fail.

Reported-by: Thomas Gilligan <thomas.gilligan@icloud.com>
Reported-by: Jesse Zhang <sbjesse@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/09A4B554-82B1-4536-B191-2461342EE0BB%40icloud.com
---
 config/c-compiler.m4 |  4 +++-
 config/c-library.m4  |  4 +++-
 configure            | 12 +++++++++---
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/config/c-compiler.m4 b/config/c-compiler.m4
index f87beb0d66..8bc6d32e23 100644
--- a/config/c-compiler.m4
+++ b/config/c-compiler.m4
@@ -71,8 +71,10 @@ int does_int64_work()
     return 0;
   return 1;
 }
+
+int
 main() {
-  exit(! does_int64_work());
+  return (! does_int64_work());
 }])],
 [Ac_cachevar=yes],
 [Ac_cachevar=no],
diff --git a/config/c-library.m4 b/config/c-library.m4
index 82b161417a..a893d68e02 100644
--- a/config/c-library.m4
+++ b/config/c-library.m4
@@ -204,8 +204,10 @@ int does_int64_snprintf_work()
     return 0;			/* either multiply or snprintf is busted */
   return 1;
 }
+
+int
 main() {
-  exit(! does_int64_snprintf_work());
+  return (! does_int64_snprintf_work());
 }]])],
 [pgac_cv_snprintf_long_long_int_modifier=$pgac_modifier; break],
 [],
diff --git a/configure b/configure
index d4442f3828..394f658e35 100755
--- a/configure
+++ b/configure
@@ -13853,8 +13853,10 @@ int does_int64_work()
     return 0;
   return 1;
 }
+
+int
 main() {
-  exit(! does_int64_work());
+  return (! does_int64_work());
 }
 _ACEOF
 if ac_fn_c_try_run "$LINENO"; then :
@@ -13935,8 +13937,10 @@ int does_int64_work()
     return 0;
   return 1;
 }
+
+int
 main() {
-  exit(! does_int64_work());
+  return (! does_int64_work());
 }
 _ACEOF
 if ac_fn_c_try_run "$LINENO"; then :
@@ -14011,8 +14015,10 @@ int does_int64_snprintf_work()
     return 0;			/* either multiply or snprintf is busted */
   return 1;
 }
+
+int
 main() {
-  exit(! does_int64_snprintf_work());
+  return (! does_int64_snprintf_work());
 }
 _ACEOF
 if ac_fn_c_try_run "$LINENO"; then :