Merge pull request #1711 from tmat/PdbTimestamp

Fix timestamp written to Debug Image Directory

src/Compilers/Core/Portable/PEWriter/ISymbolWriter.cs

@@ -58,6 +58,17 @@ internal interface ISymUnmanagedWriter2
         void DefineConstant2([MarshalAs(UnmanagedType.LPWStr)] string name, VariantStructure value, uint sigToken);
     }
 
+    [ComImport, InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("98ECEE1E-752D-11d3-8D56-00C04F680B2B"), SuppressUnmanagedCodeSecurity]
+    internal interface IPdbWriter
+    {
+        int __SetPath(/*[in] const WCHAR* szFullPathName, [in] IStream* pIStream, [in] BOOL fFullBuild*/);
+        int __OpenMod(/*[in] const WCHAR* szModuleName, [in] const WCHAR* szFileName*/);
+        int __CloseMod();
+        int __GetPath(/*[in] DWORD ccData,[out] DWORD* pccData,[out, size_is(ccData),length_is(*pccData)] WCHAR szPath[]*/);
+
+        void GetSignatureAge(out uint sig, out uint age);
+    }
+
     internal static class ISymUnmanagedWriter2Helper
     {
         public static unsafe void DefineConstant2(this ISymUnmanagedWriter2 writer, string name, object value, uint sigToken)

src/Compilers/Core/Portable/PEWriter/PdbWriter.cs

@@ -577,7 +577,7 @@ public void SetMetadataEmitter(MetadataWriter metadataWriter)
             }
         }
 
-        public unsafe Guid GetDebugDirectoryGuid()
+        public unsafe void GetDebugDirectoryGuidAndStamp(out Guid guid, out uint stamp)
         {
             // See symwrite.cpp - the data byte[] doesn't depend on the content of metadata tables or IL.
             // The writer only sets two values of the ImageDebugDirectory struct.
@@ -626,7 +626,13 @@ public unsafe Guid GetDebugDirectoryGuid()
             byte[] guidBytes = new byte[GuidSize];
             Buffer.BlockCopy(data, 4, guidBytes, 0, guidBytes.Length);
 
-            return new Guid(guidBytes);
+            guid = new Guid(guidBytes);
+
+            // Retrieve the timestamp the PDB writer generates when creating a new PDB stream.
+            // Note that ImageDebugDirectory.TimeDateStamp is not set by GetDebugInfo, 
+            // we need to go thru IPdbWriter interface to get it.
+            uint age;
+            ((IPdbWriter)_symWriter).GetSignatureAge(out stamp, out age);
         }
 
         public void SetEntryPoint(uint entryMethodToken)

src/Compilers/Core/Portable/PEWriter/PeWriter.cs

@@ -1442,12 +1442,24 @@ private void WriteDebugTable(Stream peStream, MetadataSizes metadataSizes, out l
             MemoryStream stream = new MemoryStream();
             BinaryWriter writer = new BinaryWriter(stream);
 
+            Guid pdbId;
+            uint pdbStamp;
+            if (_nativePdbWriterOpt != null)
+            {
+                _nativePdbWriterOpt.GetDebugDirectoryGuidAndStamp(out pdbId, out pdbStamp);
+            }
+            else
+            {
+                pdbId = Guid.NewGuid();
+                pdbStamp = 0;
+            } 
+
             // characteristics:
             writer.WriteUint(0);
 
             // timestamp from NT headers
             timestampOffset = writer.BaseStream.Position + peStream.Position;
-            writer.WriteUint(_ntHeader.TimeDateStamp);
+            writer.WriteUint(pdbStamp);
 
             // version
             writer.WriteUint(0);
@@ -1472,9 +1484,7 @@ private void WriteDebugTable(Stream peStream, MetadataSizes metadataSizes, out l
             writer.WriteByte((byte)'D');
             writer.WriteByte((byte)'S');
 
-            // TODO: use deterministic hash
-            Guid guid = _nativePdbWriterOpt?.GetDebugDirectoryGuid() ?? Guid.NewGuid();
-            writer.WriteBytes(guid.ToByteArray());
+            writer.WriteBytes(pdbId.ToByteArray());
 
             // Age (EnC generation + 1): always 0x00000001.
             // We don't emit PE files when emitting EnC deltas.