Added UniverseOptions.DeterministicOutput to enable deterministic output (i.e. setting the PE file header time stamp to zero and computing the module version id based on the contents, instead of using a random guid).

7 files changed, 99 insertions, 11 deletions

diff --git a/reflect/Emit/ModuleBuilder.cs b/reflect/Emit/ModuleBuilder.cs
index 646c3553..b415262d 100644
--- a/reflect/Emit/ModuleBuilder.cs
+++ b/reflect/Emit/ModuleBuilder.cs
@@ -41,8 +41,8 @@ namespace IKVM.Reflection.Emit
 	public sealed class ModuleBuilder : Module, ITypeOwner
 	{
 		private static readonly bool usePublicKeyAssemblyReference = false;
-		private Guid mvid = Guid.NewGuid();
-		private DateTime timestamp = DateTime.UtcNow;
+		private Guid mvid;
+		private uint timestamp;
 		private long imageBaseAddress = 0x00400000;
 		private long stackReserve = -1;
 		private int fileAlignment = 0x200;
@@ -251,6 +251,15 @@ namespace IKVM.Reflection.Emit
 			if (emitSymbolInfo)
 			{
 				symbolWriter = SymbolSupport.CreateSymbolWriterFor(this);
+				if (universe.Deterministic && !symbolWriter.IsDeterministic)
+				{
+					throw new NotSupportedException();
+				}
+			}
+			if (!universe.Deterministic)
+			{
+				__PEHeaderTimeDateStamp = DateTime.UtcNow;
+				mvid = Guid.NewGuid();
 			}
 			// <Module> must be the first record in the TypeDef table
 			moduleType = new TypeBuilder(this, null, "<Module>");
@@ -1122,7 +1131,7 @@ namespace IKVM.Reflection.Emit
 			}
 		}
 
-		internal void WriteMetadata(MetadataWriter mw)
+		internal void WriteMetadata(MetadataWriter mw, out int guidHeapOffset)
 		{
 			mw.Write(0x424A5342);			// Signature ("BSJB")
 			mw.Write((ushort)1);			// MajorVersion
@@ -1175,6 +1184,7 @@ namespace IKVM.Reflection.Emit
 			Tables.Write(mw);
 			Strings.Write(mw);
 			UserStrings.Write(mw);
+			guidHeapOffset = mw.Position;
 			Guids.Write(mw);
 			if (!Blobs.IsEmpty)
 			{
@@ -1396,26 +1406,49 @@ namespace IKVM.Reflection.Emit
 			get { return fileName; }
 		}
 
+		internal Guid GetModuleVersionIdOrEmpty()
+		{
+			return mvid;
+		}
+
 		public override Guid ModuleVersionId
 		{
-			get { return mvid; }
+			get
+			{
+				if (mvid == Guid.Empty && universe.Deterministic)
+				{
+					// if a deterministic GUID is used, it can't be queried before the assembly has been written
+					throw new InvalidOperationException();
+				}
+				return mvid;
+			}
 		}
 
 		public void __SetModuleVersionId(Guid guid)
 		{
+			if (guid == Guid.Empty && universe.Deterministic)
+			{
+				// if you want to use Guid.Empty, don't set UniverseOptions.DeterministicOutput
+				throw new ArgumentOutOfRangeException();
+			}
 			mvid = guid;
 		}
 
+		internal uint GetTimeDateStamp()
+		{
+			return timestamp;
+		}
+
 		public DateTime __PEHeaderTimeDateStamp
 		{
-			get { return timestamp; }
+			get { return new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc).AddSeconds(timestamp); }
 			set
 			{
 				if (value < new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc) || value > new DateTime(2106, 2, 7, 6, 28, 15, DateTimeKind.Utc))
 				{
 					throw new ArgumentOutOfRangeException();
 				}
-				timestamp = value;
+				timestamp = (uint)(value - new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc)).TotalSeconds;
 			}
 		}
 
diff --git a/reflect/Impl/MdbWriter.cs b/reflect/Impl/MdbWriter.cs
index 226137b9..4d1e2cd7 100644
--- a/reflect/Impl/MdbWriter.cs
+++ b/reflect/Impl/MdbWriter.cs
@@ -228,6 +228,11 @@ namespace IKVM.Reflection.Impl
 		{
 			throw new InvalidOperationException();
 		}
+
+		public bool IsDeterministic
+		{
+			get { return true; }
+		}
 	}
 }
 #endif // MONO
diff --git a/reflect/Impl/PdbWriter.cs b/reflect/Impl/PdbWriter.cs
index b8976bbf..4d8fc1d8 100644
--- a/reflect/Impl/PdbWriter.cs
+++ b/reflect/Impl/PdbWriter.cs
@@ -1184,5 +1184,10 @@ namespace IKVM.Reflection.Impl
 		{
 			throw new NotImplementedException();
 		}
+
+		public bool IsDeterministic
+		{
+			get { return false; }
+		}
 	}
 }
diff --git a/reflect/Impl/SymbolSupport.cs b/reflect/Impl/SymbolSupport.cs
index c573b2b5..7b4e8906 100644
--- a/reflect/Impl/SymbolSupport.cs
+++ b/reflect/Impl/SymbolSupport.cs
@@ -55,6 +55,7 @@ namespace IKVM.Reflection.Impl
 		void RemapToken(int oldToken, int newToken);
 		void DefineLocalVariable2(string name, FieldAttributes attributes, int signature, int addrKind, int addr1, int addr2, int addr3, int startOffset, int endOffset);
 		void OpenMethod(SymbolToken symbolToken, MethodBase mb);
+		bool IsDeterministic { get; }
 	}
 #else
 	interface ISymbolWriterImpl : ISymbolWriter
@@ -63,6 +64,7 @@ namespace IKVM.Reflection.Impl
 		void RemapToken(int oldToken, int newToken);
 		void DefineLocalVariable2(string name, FieldAttributes attributes, int signature, SymAddressKind addrKind, int addr1, int addr2, int addr3, int startOffset, int endOffset);
 		void OpenMethod(SymbolToken symbolToken, MethodBase mb);
+		bool IsDeterministic { get; }
 	}
 #endif
 
diff --git a/reflect/Universe.cs b/reflect/Universe.cs
index 30ed1204..82fad202 100644
--- a/reflect/Universe.cs
+++ b/reflect/Universe.cs
@@ -115,6 +115,12 @@ namespace IKVM.Reflection
 	 *      - Module.__ReadDataFromRVA()
 	 *      - MethodBase.GetMethodBody()
 	 *      - FieldInfo.__GetDataFromRVA()
+	 *
+	 *   DeterministicOutput
+	 *      The generated output file will depend only on the input. In other words,
+	 *      the PE file header time stamp will be set to zero and the module version
+	 *      id will be based on a SHA1 of the contents, instead of a random guid.
+	 *      This option can not be used in combination with PDB file generation.
 	 */
 
 	[Flags]
@@ -129,6 +135,8 @@ namespace IKVM.Reflection
 		ResolveMissingMembers = 32,
 		DisableWindowsRuntimeProjection = 64,
 		DecodeVersionInfoAttributeBlobs = 128,
+		DeterministicOutput = 256,
+
 		SupressReferenceTypeIdentityConversion = 1 << 20
 	}
 
@@ -1250,5 +1258,10 @@ namespace IKVM.Reflection
 		{
 			get { return (options & UniverseOptions.SupressReferenceTypeIdentityConversion) != 0; }
 		}
+
+		internal bool Deterministic
+		{
+			get { return (options & UniverseOptions.DeterministicOutput) != 0; }
+		}
 	}
 }
diff --git a/reflect/Writer/ModuleWriter.cs b/reflect/Writer/ModuleWriter.cs
index ba3bf85a..7ef9c6d6 100644
--- a/reflect/Writer/ModuleWriter.cs
+++ b/reflect/Writer/ModuleWriter.cs
@@ -81,7 +81,8 @@ namespace IKVM.Reflection.Writer
 			moduleBuilder.ApplyUnmanagedExports(imageFileMachine);
 			moduleBuilder.FixupMethodBodyTokens();
 
-			moduleBuilder.ModuleTable.Add(0, moduleBuilder.Strings.Add(moduleBuilder.moduleName), moduleBuilder.Guids.Add(moduleBuilder.ModuleVersionId), 0, 0);
+			int moduleVersionIdIndex = moduleBuilder.Guids.Add(moduleBuilder.GetModuleVersionIdOrEmpty());
+			moduleBuilder.ModuleTable.Add(0, moduleBuilder.Strings.Add(moduleBuilder.moduleName), moduleVersionIdIndex, 0, 0);
 
 			if (moduleBuilder.UserStrings.IsEmpty)
 			{
@@ -213,7 +214,7 @@ namespace IKVM.Reflection.Writer
 			}
 
 			// Set the PE File timestamp
-			writer.Headers.FileHeader.TimeDateStamp = (uint)(moduleBuilder.__PEHeaderTimeDateStamp - new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc)).TotalSeconds;
+			writer.Headers.FileHeader.TimeDateStamp = moduleBuilder.GetTimeDateStamp();
 
 			// we need to start by computing the number of sections, because code.PointerToRawData depends on that
 			writer.Headers.FileHeader.NumberOfSections = 2;
@@ -312,7 +313,8 @@ namespace IKVM.Reflection.Writer
 			}
 
 			stream.Seek(text.PointerToRawData, SeekOrigin.Begin);
-			code.Write(mw, sdata.VirtualAddress);
+			int guidHeapOffset;
+			code.Write(mw, sdata.VirtualAddress, out guidHeapOffset);
 
 			if (sdata.SizeOfRawData != 0)
 			{
@@ -335,6 +337,15 @@ namespace IKVM.Reflection.Writer
 			// file alignment
 			stream.SetLength(reloc.PointerToRawData + reloc.SizeOfRawData);
 
+			// if we don't have a guid, generate one based on the contents of the assembly
+			if (moduleBuilder.universe.Deterministic && moduleBuilder.GetModuleVersionIdOrEmpty() == Guid.Empty)
+			{
+				Guid guid = GenerateModuleVersionId(stream);
+				stream.Position = guidHeapOffset + (moduleVersionIdIndex - 1) * 16;
+				stream.Write(guid.ToByteArray(), 0, 16);
+				moduleBuilder.__SetModuleVersionId(guid);
+			}
+
 			// do the strong naming
 			if (keyPair != null)
 			{
@@ -429,5 +440,24 @@ namespace IKVM.Reflection.Writer
 				length -= read;
 			}
 		}
+
+		private static Guid GenerateModuleVersionId(Stream stream)
+		{
+			SHA1Managed hash = new SHA1Managed();
+			using (CryptoStream cs = new CryptoStream(Stream.Null, hash, CryptoStreamMode.Write))
+			{
+				stream.Seek(0, SeekOrigin.Begin);
+				byte[] buf = new byte[8192];
+				HashChunk(stream, cs, buf, (int)stream.Length);
+			}
+			byte[] bytes = new byte[16];
+			Buffer.BlockCopy(hash.Hash, 0, bytes, 0, bytes.Length);
+			// set GUID type to "version 4" (random)
+			bytes[7] &= 0x0F;
+			bytes[7] |= 0x40;
+			bytes[8] &= 0x3F;
+			bytes[8] |= 0x80;
+			return new Guid(bytes);
+		}
 	}
 }
diff --git a/reflect/Writer/TextSection.cs b/reflect/Writer/TextSection.cs
index 4657d30e..fceedcf6 100644
--- a/reflect/Writer/TextSection.cs
+++ b/reflect/Writer/TextSection.cs
@@ -275,7 +275,7 @@ namespace IKVM.Reflection.Writer
 			}
 		}
 
-		internal void Write(MetadataWriter mw, uint sdataRVA)
+		internal void Write(MetadataWriter mw, uint sdataRVA, out int guidHeapOffset)
 		{
 			// Now that we're ready to start writing, we need to do some fix ups
 			moduleBuilder.TypeRef.Fixup(moduleBuilder);
@@ -356,7 +356,7 @@ namespace IKVM.Reflection.Writer
 
 			// Metadata
 			AssertRVA(mw, MetadataRVA);
-			moduleBuilder.WriteMetadata(mw);
+			moduleBuilder.WriteMetadata(mw, out guidHeapOffset);
 
 			// alignment padding
 			for (int i = (int)(VTableFixupsRVA - (MetadataRVA + MetadataLength)); i > 0; i--)