* Source/Build.Tasks/DateStamp.cs: Read/Write stamp from/to

Version.txt file. Allows a single stamp to be propagated throughout
  the build process.

* Source/Build.Tasks/GenerateAssemblyInfo.cs: Correctly invoke
  DateStamp task (need to call Execute() to generate the stamp).

* Source/Build.UpdateVersion/Build.UpdateVersion.csproj: Cleaned up
  'Rebuild' target.
Cleaned up 'GenerateAssemblyInfo' task invocation.
Attempted to generate GlobalAssemblyInfo.cs without using a custom
  task. Unfortunately, xbuild didn't wish to cooperate.
Remove Version.txt file to update the datestamp.

Source/Build.Tasks/DateStamp.cs

@@ -32,12 +32,10 @@ using Microsoft.Build.Utilities;
 
 namespace Build.Tasks
 {
-    /// <summary>
-    /// Returns a date stamp in the form yyMMdd.
-    /// </summary>
     public class DateStamp : Task
     {
         string date;
+        const string file = "../../Version.txt";
 
         /// <summary>
         /// Gets a <see cref="System.String"/> represting the date stamp.
@@ -53,12 +51,23 @@ namespace Build.Tasks
         {
             try
             {
-                // Build number is defined as the number of days since 1/1/2010.
+                // Version.txt contains the datestamp for the current build.
-                // Revision number is defined as the fraction of the current day, expressed in seconds.
+                // This is used in order to sync stamps between build tasks.
-                double timespan = DateTime.UtcNow.Subtract(new DateTime(2010, 1, 1)).TotalDays;
+                // If the file does not exist, create it.
-                string build = ((int)timespan).ToString();
+                if (System.IO.File.Exists(file))
-                string revision = ((int)((timespan - (int)timespan) * UInt16.MaxValue)).ToString();
+                {
-                Date = String.Format("{0}.{1}", build, revision);
+                    Date = System.IO.File.ReadAllLines(file)[0];
+                }
+                else
+                {
+                    // Build number is defined as the number of days since 1/1/2010.
+                    // Revision number is defined as the fraction of the current day, expressed in seconds.
+                    double timespan = DateTime.UtcNow.Subtract(new DateTime(2010, 1, 1)).TotalDays;
+                    string build = ((int)timespan).ToString();
+                    string revision = ((int)((timespan - (int)timespan) * UInt16.MaxValue)).ToString();
+                    Date = String.Format("{0}.{1}", build, revision);
+                    System.IO.File.WriteAllLines(file, new string[] { Date });
+                }
             }
             catch (Exception e)
             {

Source/Build.Tasks/GenerateAssemblyInfo.cs

@@ -48,7 +48,9 @@ namespace Build.Tasks
 
         public GenerateAssemblyInfo()
         {
-            Date = new DateStamp().Date;
+            DateStamp stamp = new DateStamp();
+            stamp.Execute();
+            Date = stamp.Date;
             Major = Major ?? "0";
             Minor = Minor ?? "0";
         }
@@ -59,7 +61,7 @@ namespace Build.Tasks
 
             using (StreamWriter sw = new StreamWriter(OutputFile, false, utf8))
             {
-                sw.WriteLine("// This file is auto-generated through Source.Build.Tasks/AssemblyInfo.cs.");
+                sw.WriteLine("// This file is auto-generated through Source/Build.Tasks/GenerateAssemblyInfo.cs.");
                 sw.WriteLine("// Do not edit by hand!");
                 sw.WriteLine();
 

Source/Build.UpdateVersion/Build.UpdateVersion.csproj

@@ -17,13 +17,43 @@
   </PropertyGroup>
   <Import Project="..\Build.Tasks\Common.xml" />
   <Target Name="UpdateVersion">
-    <GenerateAssemblyInfo OutputFile="..\GlobalAssemblyInfo.cs" AssemblyCompany="The Open Toolkit Library" AssemblyProduct="The Open Toolkit Library" AssemblyCopyright="Copyright © 2006 - 2010 the Open Toolkit Library" AssemblyTrademark="OpenTK" Major="1" Minor="0" />
+    <Delete Files="..\..\Version.txt" />
+    <GenerateAssemblyInfo
+      OutputFile="..\GlobalAssemblyInfo.cs"
+      AssemblyCompany="The Open Toolkit Library"
+      AssemblyProduct="The Open Toolkit Library"
+      AssemblyCopyright="Copyright © 2006 - 2010 the Open Toolkit Library"
+      AssemblyTrademark="OpenTK"
+      Major="1"
+      Minor="0" />
+<!-- Fails because xbuild does not respect %3b
+    <DateStamp>
+      <Output TaskParameter="Date" PropertyName="ShortDate" />
+    </DateStamp>
+    <WriteLinesToFile File="..\GlobalAssemblyInfo.cs" Overwrite="true" 
+      Lines='// This file is auto-generated through Build.UpdateVersion.csproj.;
+             // Do not edit by hand!;
+             using System%3b;
+             using System.Reflection%3b;
+             using System.Resources%3b;
+             using System.Runtime.CompilerServices%3b;
+             using System.Runtime.Runtime.InteropServices%3b;
+             ;
+             [assembly: AssemblyCompany("The Open Toolkit Library")];
+             [assembly: AssemblyProduct("The Open Toolkit Library")];
+             [assembly: AssemblyCopyright("Copyright © 2006 - 2010 the Open Toolkit Library")];
+             [assembly: AssemblyTrademark("OpenTK")];
+             [assembly: AssemblyVersion("1.0.0.0")];
+             [assembly: AssemblyFileVersion("1.0.$(ShortDate)")];
+    ' />
+-->
   </Target>
   <Target Name="Build">
     <CallTarget Targets="UpdateVersion" />
   </Target>
   <Target Name="Rebuild">
-    <CallTarget Targets="UpdateVersion" />
+    <CallTarget Targets="Clean" />
+    <CallTarget Targets="Build" />
   </Target>
   <Target Name="Clean" />
 </Project>