windows_arm_build.patch

diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index bb55695300..4a8793a785 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -4120,7 +4120,7 @@ make: *** [postgres] Error 1
    <sect3 id="install-windows-full-64-bit">
     <title>Special Considerations for 64-Bit Windows</title>
     <para>
-     PostgreSQL will only build for the x64 architecture on 64-bit Windows.
+     PostgreSQL will only build for the x64 and ARM64 architecture on 64-bit Windows.
     </para>
     <para>
      Mixing 32- and 64-bit versions in the same build tree is not supported.
diff --git a/src/tools/msvc_gendef.pl b/src/tools/msvc_gendef.pl
index 12c49ed265..dfb26916bd 100644
--- a/src/tools/msvc_gendef.pl
+++ b/src/tools/msvc_gendef.pl
@@ -120,9 +120,9 @@ sub writedef
 	{
 		my $isdata = $def->{$f} eq 'data';
 
-		# Strip the leading underscore for win32, but not x64
+		# Strip the leading underscore for win32, but not x64 and aarch64
 		$f =~ s/^_//
-		  unless ($arch eq "x86_64");
+		  unless ($arch eq "x86_64" || $arch eq "aarch64");
 
 		# Emit just the name if it's a function symbol, or emit the name
 		# decorated with the DATA option for variables.
@@ -143,7 +143,7 @@ sub writedef
 sub usage
 {
 	die("Usage: msvc_gendef.pl --arch <arch> --deffile <deffile> --tempdir <tempdir> files-or-directories\n"
-		  . "    arch: x86 | x86_64\n"
+		  . "    arch: x86 | x86_64 | aarch64\n"
 		  . "    deffile: path of the generated file\n"
 		  . "    tempdir: directory for temporary files\n"
 		  . "    files or directories: object files or directory containing object files\n"
@@ -160,7 +160,7 @@ GetOptions(
 	'tempdir:s' => \$tempdir,) or usage();
 
 usage("arch: $arch")
-  unless ($arch eq 'x86' || $arch eq 'x86_64');
+  unless ($arch eq 'x86' || $arch eq 'x86_64' || $arch eq 'aarch64');
 
 my @files;