[XamlC] support portable pdb (#726)

3 files changed, 56 insertions, 6 deletions

diff --git a/Xamarin.Forms.Build.Tasks/DebugXamlCTask.cs b/Xamarin.Forms.Build.Tasks/DebugXamlCTask.cs
index 1c7acac4..d356c9c6 100644
--- a/Xamarin.Forms.Build.Tasks/DebugXamlCTask.cs
+++ b/Xamarin.Forms.Build.Tasks/DebugXamlCTask.cs
@@ -46,7 +46,7 @@ namespace Xamarin.Forms.Build.Tasks
 			using (var assemblyDefinition = AssemblyDefinition.ReadAssembly(Assembly, new ReaderParameters {
 				ReadWrite = true,
 				ReadSymbols = DebugSymbols,
-				SymbolReaderProvider = System.Type.GetType("Mono.Runtime") != null ? ((ISymbolReaderProvider)(new MdbReaderProvider())) : ((ISymbolReaderProvider)new PdbReaderProvider()),
+				SymbolReaderProvider = GetSymbolReaderProvider(Assembly, DebugSymbols),
 				AssemblyResolver = resolver
 			})) {
 				foreach (var module in assemblyDefinition.Modules) {
@@ -146,7 +146,7 @@ namespace Xamarin.Forms.Build.Tasks
 				}
 				Logger.LogString(1, "Writing the assembly... ");
 				assemblyDefinition.Write(new WriterParameters {
-					SymbolWriterProvider = System.Type.GetType("Mono.Runtime") != null ? ((ISymbolWriterProvider)(new MdbWriterProvider())) : ((ISymbolWriterProvider)new MdbWriterProvider()),
+					SymbolWriterProvider = GetSymbolWriterProvider(Assembly, DebugSymbols),
 					WriteSymbols = DebugSymbols
 				});
 			}
diff --git a/Xamarin.Forms.Build.Tasks/XamlCTask.cs b/Xamarin.Forms.Build.Tasks/XamlCTask.cs
index 051eac0f..d014d059 100644
--- a/Xamarin.Forms.Build.Tasks/XamlCTask.cs
+++ b/Xamarin.Forms.Build.Tasks/XamlCTask.cs
@@ -5,8 +5,6 @@ using System.Linq;
 
 using Mono.Cecil;
 using Mono.Cecil.Cil;
-using Mono.Cecil.Mdb;
-using Mono.Cecil.Pdb;
 
 using Xamarin.Forms.Xaml;
 
@@ -74,7 +72,7 @@ namespace Xamarin.Forms.Build.Tasks
 				AssemblyResolver = resolver,
 				ReadWrite = !ReadOnly,
 				ReadSymbols = DebugSymbols,
-				SymbolReaderProvider = DebugSymbols ? (System.Type.GetType("Mono.Runtime") != null ? ((ISymbolReaderProvider)(new MdbReaderProvider())) : ((ISymbolReaderProvider)new PdbReaderProvider())) : null,
+				SymbolReaderProvider = GetSymbolReaderProvider(Assembly, DebugSymbols),
 			};
 
 			using (var assemblyDefinition = AssemblyDefinition.ReadAssembly(Path.GetFullPath(Assembly),readerParameters)) {
@@ -228,7 +226,7 @@ namespace Xamarin.Forms.Build.Tasks
 				try {
 					assemblyDefinition.Write(new WriterParameters {
 						WriteSymbols = DebugSymbols,
-						SymbolWriterProvider = DebugSymbols ? (System.Type.GetType("Mono.Runtime") != null ? ((ISymbolWriterProvider)(new MdbWriterProvider())) : ((ISymbolWriterProvider)new MdbWriterProvider())): null,
+						SymbolWriterProvider = GetSymbolWriterProvider(Assembly, DebugSymbols),
 					});
 					Logger.LogLine(1, "done.");
 				} catch (Exception e) {
diff --git a/Xamarin.Forms.Build.Tasks/XamlTask.cs b/Xamarin.Forms.Build.Tasks/XamlTask.cs
index 0456d9f3..9bfc87cf 100644
--- a/Xamarin.Forms.Build.Tasks/XamlTask.cs
+++ b/Xamarin.Forms.Build.Tasks/XamlTask.cs
@@ -11,6 +11,8 @@ using Mono.Cecil;
 
 using Xamarin.Forms.Xaml;
 using Mono.Cecil.Cil;
+using Mono.Cecil.Pdb;
+using Mono.Cecil.Mdb;
 
 namespace Xamarin.Forms.Build.Tasks
 {
@@ -58,6 +60,56 @@ namespace Xamarin.Forms.Build.Tasks
 			}
 			return rootnode;
 		}
+
+		protected static ISymbolReaderProvider GetSymbolReaderProvider(string moduleFileName, bool debugSymbols)
+		{
+			if (!debugSymbols)
+				return null;
+
+			var pdb_name = GetPdbFileName(moduleFileName);
+			if (File.Exists(pdb_name)) {
+				// TODO: check mvid match
+				return new PdbReaderProvider();
+			}
+
+			var mdb_name = GetMdbFileName(moduleFileName);
+			if (File.Exists(mdb_name)) {
+				// TODO: check mvid match
+				return new MdbReaderProvider();
+			}
+
+			return null;
+		}
+
+		protected static ISymbolWriterProvider GetSymbolWriterProvider(string moduleFileName, bool debugSymbols)
+		{
+			if (!debugSymbols)
+				return null;
+
+			var pdb_name = GetPdbFileName(moduleFileName);
+			if (File.Exists(pdb_name)) {
+				// TODO: check mvid match
+				return new PdbWriterProvider();
+			}
+
+			var mdb_name = GetMdbFileName(moduleFileName);
+			if (File.Exists(mdb_name)) {
+				// TODO: check mvid match
+				return new MdbWriterProvider();
+			}
+
+			return null;
+		}
+
+		static string GetPdbFileName(string assemblyFileName)
+		{
+			return Path.ChangeExtension(assemblyFileName, ".pdb");
+		}
+
+		static string GetMdbFileName(string assemblyFileName)
+		{
+			return assemblyFileName + ".mdb";
+		}
 	}
 
 	static class CecilExtensions