From e64a58387db46239902b610871a0eb81626e99ff Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Thu, 18 Aug 2022 07:46:28 -0700
Subject: [PATCH] Turn on -pedantic-errors at the end of 'configure'

Problem reported by Khem Raj in:
https://lists.gnu.org/r/autoconf-patches/2022-08/msg00009.html
Upstream-Status: Submitted [https://lists.samba.org/archive/rsync/2022-August/032862.html]
---
 configure.ac | 35 ++++++++++++++++++++---------------
 1 file changed, 20 insertions(+), 15 deletions(-)

diff --git a/configure.ac b/configure.ac
index d185b2d3..7e9514f7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1071,21 +1071,6 @@ elif test x"$ac_cv_header_popt_h" != x"yes"; then
     with_included_popt=yes
 fi
 
-if test x"$GCC" = x"yes"; then
-    if test x"$with_included_popt" != x"yes"; then
-	# Turn pedantic warnings into errors to ensure an array-init overflow is an error.
-	CFLAGS="$CFLAGS -pedantic-errors"
-    else
-	# Our internal popt code cannot be compiled with pedantic warnings as errors, so try to
-	# turn off pedantic warnings (which will not lose the error for array-init overflow).
-	# Older gcc versions don't understand -Wno-pedantic, so check if --help=warnings lists
-	# -Wpedantic and use that as a flag.
-	case `$CC --help=warnings 2>/dev/null | grep Wpedantic` in
-	    *-Wpedantic*) CFLAGS="$CFLAGS -pedantic-errors -Wno-pedantic" ;;
-	esac
-    fi
-fi
-
 AC_MSG_CHECKING([whether to use included libpopt])
 if test x"$with_included_popt" = x"yes"; then
     AC_MSG_RESULT($srcdir/popt)
@@ -1444,6 +1429,26 @@ case "$CC" in
     ;;
 esac
 
+# Enable -pedantic-errors last, so that it doesn't mess up other
+# 'configure' tests.  For example, Autoconf uses empty function
+# prototypes like 'int main () {}' which Clang 15's -pedantic-errors
+# would reject.  Generally it's not a good idea to try to run
+# 'configure' itself with strict compiler checking.
+if test x"$GCC" = x"yes"; then
+    if test x"$with_included_popt" != x"yes"; then
+	# Turn pedantic warnings into errors to ensure an array-init overflow is an error.
+	CFLAGS="$CFLAGS -pedantic-errors"
+    else
+	# Our internal popt code cannot be compiled with pedantic warnings as errors, so try to
+	# turn off pedantic warnings (which will not lose the error for array-init overflow).
+	# Older gcc versions don't understand -Wno-pedantic, so check if --help=warnings lists
+	# -Wpedantic and use that as a flag.
+	case `$CC --help=warnings 2>/dev/null | grep Wpedantic` in
+	    *-Wpedantic*) CFLAGS="$CFLAGS -pedantic-errors -Wno-pedantic" ;;
+	esac
+    fi
+fi
+
 AC_CONFIG_FILES([Makefile lib/dummy zlib/dummy popt/dummy shconfig])
 AC_OUTPUT
 
-- 
2.37.1