Imported Upstream version 5.0.0.42

Former-commit-id: fd56571888259555122d8a0f58c68838229cea2b

external/linker/cecil/symbols/pdb/Mono.Cecil.Pdb/PdbHelper.cs

@@ -0,0 +1,142 @@
+//
+// Author:
+//   Jb Evain (jbevain@gmail.com)
+//
+// Copyright (c) 2008 - 2015 Jb Evain
+// Copyright (c) 2008 - 2011 Novell, Inc.
+//
+// Licensed under the MIT/X11 license.
+//
+
+using System;
+using System.IO;
+
+using Mono.Cecil.Cil;
+
+namespace Mono.Cecil.Pdb {
+
+	public sealed class NativePdbReaderProvider : ISymbolReaderProvider {
+
+		public ISymbolReader GetSymbolReader (ModuleDefinition module, string fileName)
+		{
+			Mixin.CheckModule (module);
+			Mixin.CheckFileName (fileName);
+
+			return new PdbReader (Disposable.Owned (File.OpenRead (Mixin.GetPdbFileName (fileName)) as Stream));
+		}
+
+		public ISymbolReader GetSymbolReader (ModuleDefinition module, Stream symbolStream)
+		{
+			Mixin.CheckModule (module);
+			Mixin.CheckStream (symbolStream);
+
+			return new PdbReader (Disposable.NotOwned (symbolStream));
+		}
+	}
+
+	public sealed class PdbReaderProvider : ISymbolReaderProvider {
+
+		public ISymbolReader GetSymbolReader (ModuleDefinition module, string fileName)
+		{
+			Mixin.CheckModule (module);
+			Mixin.CheckFileName (fileName);
+
+			return IsPortablePdb (Mixin.GetPdbFileName (fileName))
+				? new PortablePdbReaderProvider ().GetSymbolReader (module, fileName)
+				: new NativePdbReaderProvider ().GetSymbolReader (module, fileName);
+		}
+
+		public ISymbolReader GetSymbolReader (ModuleDefinition module, Stream symbolStream)
+		{
+			Mixin.CheckModule (module);
+			Mixin.CheckStream (symbolStream);
+			Mixin.CheckReadSeek (symbolStream);
+
+			return IsPortablePdb (symbolStream)
+				? new PortablePdbReaderProvider ().GetSymbolReader (module, symbolStream)
+				: new NativePdbReaderProvider ().GetSymbolReader (module, symbolStream);
+		}
+
+		static bool IsPortablePdb (string fileName)
+		{
+			using (var file = new FileStream (fileName, FileMode.Open, FileAccess.Read, FileShare.None))
+				return IsPortablePdb (file);
+		}
+
+		static bool IsPortablePdb (Stream stream)
+		{
+			const uint ppdb_signature = 0x424a5342;
+
+			var position = stream.Position;
+			try {
+				var reader = new BinaryReader (stream);
+				return reader.ReadUInt32 () == ppdb_signature;
+			} finally {
+				stream.Position = position;
+			}
+		}
+	}
+
+#if !READ_ONLY
+
+	public sealed class NativePdbWriterProvider : ISymbolWriterProvider {
+
+		public ISymbolWriter GetSymbolWriter (ModuleDefinition module, string fileName)
+		{
+			Mixin.CheckModule (module);
+			Mixin.CheckFileName (fileName);
+
+			return new PdbWriter (module, CreateWriter (module, Mixin.GetPdbFileName (fileName)));
+		}
+
+		static SymWriter CreateWriter (ModuleDefinition module, string pdb)
+		{
+			var writer = new SymWriter ();
+
+			if (File.Exists (pdb))
+				File.Delete (pdb);
+
+			writer.Initialize (new ModuleMetadata (module), pdb, true);
+
+			return writer;
+		}
+
+		public ISymbolWriter GetSymbolWriter (ModuleDefinition module, Stream symbolStream)
+		{
+			throw new NotImplementedException ();
+		}
+	}
+
+	public sealed class PdbWriterProvider : ISymbolWriterProvider {
+
+		public ISymbolWriter GetSymbolWriter (ModuleDefinition module, string fileName)
+		{
+			Mixin.CheckModule (module);
+			Mixin.CheckFileName (fileName);
+
+			if (HasPortablePdbSymbols (module))
+				return new PortablePdbWriterProvider ().GetSymbolWriter (module, fileName);
+
+			return new NativePdbWriterProvider ().GetSymbolWriter (module, fileName);
+		}
+
+		static bool HasPortablePdbSymbols (ModuleDefinition module)
+		{
+			return module.symbol_reader != null && module.symbol_reader is PortablePdbReader;
+		}
+
+		public ISymbolWriter GetSymbolWriter (ModuleDefinition module, Stream symbolStream)
+		{
+			Mixin.CheckModule (module);
+			Mixin.CheckStream (symbolStream);
+			Mixin.CheckReadSeek (symbolStream);
+
+			if (HasPortablePdbSymbols (module))
+				return new PortablePdbWriterProvider ().GetSymbolWriter (module, symbolStream);
+
+			return new NativePdbWriterProvider ().GetSymbolWriter (module, symbolStream);
+		}
+	}
+
+#endif
+}