Building PostgreSQL extensions on Windows

diff --git a/src/tools/msvc/MSBuildProject.pm b/src/tools/msvc/MSBuildProject.pm
index ebb169e201..5bbab6ac29 100644
--- a/src/tools/msvc/MSBuildProject.pm
+++ b/src/tools/msvc/MSBuildProject.pm
@@ -373,7 +373,11 @@ EOF
 	print $f <<EOF;
     </Link>
     <ResourceCompile>
-      <AdditionalIncludeDirectories>src\\include;\%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>
+EOF
+	print $f "$self->{includes}";
+	print $f <<EOF;
+src\\include;\%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
     </ResourceCompile>
 EOF
 	if ($self->{builddef})
@@ -381,7 +385,7 @@ EOF
 		print $f <<EOF;
     <PreLinkEvent>
       <Message>Generate DEF file</Message>
-      <Command>perl src\\tools\\msvc\\gendef.pl $cfgname\\$self->{name} $self->{platform}</Command>
+      <Command>perl $self->{abspath}src\\tools\\msvc\\gendef.pl $cfgname\\$self->{name} $self->{platform}</Command>
     </PreLinkEvent>
 EOF
 	}
diff --git a/src/tools/msvc/Project.pm b/src/tools/msvc/Project.pm
index 20f79b382b..6f69807532 100644
--- a/src/tools/msvc/Project.pm
+++ b/src/tools/msvc/Project.pm
@@ -34,6 +34,7 @@ sub _new
 		disablewarnings       => '4018;4244;4273;4102;4090;4267',
 		disablelinkerwarnings => '',
 		platform              => $solution->{platform},
+		abspath               => '',
 	};
 
 	bless($self, $classname);
@@ -317,19 +318,18 @@ sub AddDirResourceFile
 sub AddResourceFile
 {
 	my ($self, $dir, $desc, $ico) = @_;
-
 	my ($sec, $min, $hour, $mday, $mon, $year, $wday, $yday, $isdst) =
 	  localtime(time);
 	my $d = sprintf("%02d%03d", ($year - 100), $yday);
 
-	if (Solution::IsNewer("$dir/win32ver.rc", 'src/port/win32ver.rc'))
+	if (Solution::IsNewer("$dir/win32ver.rc", "$self->{abspath}src/port/win32ver.rc"))
 	{
 		print "Generating win32ver.rc for $dir\n";
-		open(my $i, '<', 'src/port/win32ver.rc')
+		open(my $i, '<', "$self->{abspath}src/port/win32ver.rc")
 		  || confess "Could not open win32ver.rc";
 		open(my $o, '>', "$dir/win32ver.rc")
 		  || confess "Could not write win32ver.rc";
-		my $icostr = $ico ? "IDI_ICON ICON \"src/port/$ico.ico\"" : "";
+		my $icostr = $ico ? "IDI_ICON ICON \"$self->{abspath}src/port/$ico.ico\"" : "";
 		while (<$i>)
 		{
 			s/FILEDESC/"$desc"/gm;
diff --git a/src/tools/msvc/extbuild.pl b/src/tools/msvc/extbuild.pl
new file mode 100644
index 0000000000..baf2d1de10
--- /dev/null
+++ b/src/tools/msvc/extbuild.pl
@@ -0,0 +1,161 @@
+# src/tools/msvc/extbuild.pl
+
+package Mkvcbuild;
+
+use strict;
+use warnings;
+use Cwd;
+use File::Basename;
+
+use Mkvcbuild;
+
+my $solution;
+my $bconf     = $ENV{CONFIG}   || "Release";
+my $msbflags  = $ENV{MSBFLAGS} || "";
+my $makefiledir = $ARGV[0]       || "";
+my $pgconfigdir = $ARGV[1]      || "";
+my $pgincludedir = "";	# filled by output from pg_config.exe
+my $pglibdir = "";	# filled by output from pg_config.exe
+
+sub ProcessPgConfigOutput
+{
+	my $pgconfigdir = shift;
+	my $pgconfig;
+	my $output;
+
+	if ($pgconfigdir ne '')
+	{
+		$pgconfig = $pgconfigdir . "/pg_config.exe";
+	}
+	else
+	{
+		$pgconfig = "pg_config.exe";
+	}
+
+	if (-e $pgconfig)
+	{
+		# Run the pg_config command
+		$output = `$pgconfig`;
+
+		# parse the stdout of the pg_config command and extract some details.
+		if ($output =~ /^INCLUDEDIR\s*=\s*(.*)$/mg)
+		{
+			$pgincludedir = $1;
+		}
+
+		if ($output =~ /^LIBDIR\s*=\s*(.*)$/mg)
+		{
+			$pglibdir = $1;
+		}
+	}
+	else
+	{
+		die("Cannot find $pgconfig\n");
+	}
+}
+
+
+# Create the vcxproj file for the extension
+sub BuildExtensionProjectFile
+{
+	my $subdir = shift;
+	my $scriptdir = shift;
+	my $mf     = Project::read_file("$subdir/Makefile");
+	my $name;
+	my $proj;
+	my $visualStudioVersion = VSObjectFactory::DetermineVisualStudioVersion();
+	my $solution = CreateSolution($visualStudioVersion);
+	if ($mf =~ /^MODULE_big\s*=\s*(.*)$/mg)
+	{
+		$name = $1;
+		$proj = VSObjectFactory::CreateProject($visualStudioVersion, $name, 'dll', $solution);
+	}
+	elsif ($mf =~ /^MODULES\s*=\s*(.*)$/mg)
+	{
+		foreach my $mod (split /\s+/, $1)
+		{
+			$proj = VSObjectFactory::CreateProject($visualStudioVersion, $mod, 'dll', $solution);
+			my $filename = $mod . '.c';
+			$proj->AddFile("$subdir/$filename");
+		}
+	}
+	elsif ($mf =~ /^PROGRAM\s*=\s*(.*)$/mg)
+	{
+		$name = $1;
+		$proj = VSObjectFactory::CreateProject($visualStudioVersion, $1, 'exe', $solution);
+	}
+	else
+	{
+		die("Could not determine extension type for $subdir\n");
+	}
+	$proj->{abspath} = $scriptdir . "\\..\\..\\..\\";
+	$proj->AddDirResourceFile($subdir);
+	$proj->AddDir($subdir);
+	$proj->AddIncludeDir($pgincludedir);
+	$proj->AddIncludeDir("$pgincludedir/server");
+	$proj->AddIncludeDir("$pgincludedir/server/port/win32");
+	$proj->AddIncludeDir("$pgincludedir/server/port/win32_msvc");
+	$proj->AddLibrary($pglibdir . '/postgres.lib');
+	$proj->AddLibrary($pglibdir . '/libpq.lib');
+
+	#$proj->AddReference("$pglibdir/postgres");
+	# Are there any output data files to build?
+	GenerateContribSqlFiles($subdir, $mf);
+	$proj->Save();
+	return $name;
+}
+
+
+my $num_args = $#ARGV + 1;
+
+if ($num_args < 1)
+{
+	print("Usage: extbuild.pl <path_to_make_file> [path_to_pg_config] [DEBUG]");
+	exit;
+}
+
+# buildenv.pl is for specifying the build environment settings
+# it should contain lines like:
+# $ENV{PATH} = "c:/path/to/bison/bin;$ENV{PATH}";
+
+if (-e "src/tools/msvc/buildenv.pl")
+{
+	do "./src/tools/msvc/buildenv.pl";
+}
+elsif (-e "./buildenv.pl")
+{
+	do "./buildenv.pl";
+}
+
+if ($num_args >= 3)
+{
+	if (uc($ARGV[2]) eq 'DEBUG')
+	{
+		$bconf = "Debug";
+	}
+	elsif (uc($ARGV[2]) eq 'RELEASE')
+	{
+		$bconf = "Release";
+	}
+}
+
+my $name;
+
+my $scriptdir = dirname(Cwd::abs_path(__FILE__));
+chdir $makefiledir;
+
+ProcessPgConfigOutput($pgconfigdir);
+
+print("Makefile dir         = $makefiledir\n");
+print("Postgres include dir = $pgincludedir\n");
+print("Building             = $bconf\n");
+
+$name = BuildExtensionProjectFile($makefiledir, $scriptdir);
+
+system(
+	"msbuild $makefiledir/$name.vcxproj /verbosity:normal $msbflags /p:Configuration=$bconf"
+);
+
+
+
+