Fix mixed module ReadSymbols() (#851)

Fix reading some pdb generated by the C++ compiler for mixed mode assemblies.

Co-authored-by: Marco Rossignoli <mrossignol@microsoft.com>

symbols/pdb/Microsoft.Cci.Pdb/PdbFile.cs

@@ -68,9 +68,9 @@ static Dictionary<string, int> LoadNameIndex(BitAccess bits, out int age, out Gu
 
       BitSet present = new BitSet(bits);
       BitSet deleted = new BitSet(bits);
-      if (!deleted.IsEmpty) {
-        throw new PdbDebugException("Unsupported PDB deleted bitset is not empty.");
-      }
+      //if (!deleted.IsEmpty) {
+      //  throw new PdbDebugException("Unsupported PDB deleted bitset is not empty.");
+      //}
 
       int j = 0;
       for (int i = 0; i < max; i++) {

symbols/pdb/Test/Mono.Cecil.Tests/PdbTests.cs

@@ -1,6 +1,5 @@
 using System.IO;
 using System.Linq;
-
 using Mono.Cecil.Cil;
 using Mono.Cecil.Pdb;
 
@@ -56,7 +55,7 @@ .locals init (System.Int32 i, System.Int32 CS$1$0000, System.Boolean CS$4$0001)
 	IL_0020: ldloc.1
 	IL_0021: ret
 ", main);
-			}, readOnly: !Platform.HasNativePdbSupport, symbolReaderProvider: typeof(PdbReaderProvider), symbolWriterProvider: typeof(PdbWriterProvider));
+			}, readOnly: !Platform.HasNativePdbSupport, symbolReaderProvider: typeof (PdbReaderProvider), symbolWriterProvider: typeof (PdbWriterProvider));
 		}
 
 		[Test]
@@ -82,7 +81,7 @@ public void DebuggerHiddenVariable ()
 
 				Assert.AreEqual ("i", variables [0].Name);
 				Assert.IsFalse (variables [0].IsDebuggerHidden);
-			}, readOnly: !Platform.HasNativePdbSupport, symbolReaderProvider: typeof(PdbReaderProvider), symbolWriterProvider: typeof(PdbWriterProvider));
+			}, readOnly: !Platform.HasNativePdbSupport, symbolReaderProvider: typeof (PdbReaderProvider), symbolWriterProvider: typeof (PdbWriterProvider));
 		}
 
 		[Test]
@@ -103,7 +102,7 @@ public void Document ()
 				Assert.AreEqual (new byte [] { 228, 176, 152, 54, 82, 238, 238, 68, 237, 156, 5, 142, 118, 160, 118, 245 }, document.Hash);
 				Assert.AreEqual (DocumentLanguage.CSharp, document.Language);
 				Assert.AreEqual (DocumentLanguageVendor.Microsoft, document.LanguageVendor);
-			}, readOnly: !Platform.HasNativePdbSupport, symbolReaderProvider: typeof(PdbReaderProvider), symbolWriterProvider: typeof(PdbWriterProvider));
+			}, readOnly: !Platform.HasNativePdbSupport, symbolReaderProvider: typeof (PdbReaderProvider), symbolWriterProvider: typeof (PdbWriterProvider));
 		}
 
 		[Test]
@@ -124,7 +123,7 @@ public void BasicDocument ()
 				Assert.AreEqual (new byte [] { 184, 188, 100, 23, 27, 123, 187, 201, 175, 206, 110, 198, 242, 139, 154, 119 }, document.Hash);
 				Assert.AreEqual (DocumentLanguage.Basic, document.Language);
 				Assert.AreEqual (DocumentLanguageVendor.Microsoft, document.LanguageVendor);
-			}, readOnly: !Platform.HasNativePdbSupport, symbolReaderProvider: typeof(PdbReaderProvider), symbolWriterProvider: typeof(PdbWriterProvider));
+			}, readOnly: !Platform.HasNativePdbSupport, symbolReaderProvider: typeof (PdbReaderProvider), symbolWriterProvider: typeof (PdbWriterProvider));
 		}
 
 		[Test]
@@ -248,7 +247,7 @@ public void LocalConstants ()
 
 				constant = scope.Constants [1];
 				Assert.AreEqual ("c", constant.Name);
-				Assert.AreEqual ((decimal) 74, constant.Value);
+				Assert.AreEqual ((decimal)74, constant.Value);
 				Assert.AreEqual (MetadataType.ValueType, constant.ConstantType.MetadataType);
 
 				method = type.GetMethod ("Foo");
@@ -448,7 +447,7 @@ public void CreateMethodFromScratch ()
 
 			method.DebugInformation.SequencePoints.Add (sequence_point);
 
-			method.DebugInformation.Scope = new ScopeDebugInformation  (body.Instructions [0], null) {
+			method.DebugInformation.Scope = new ScopeDebugInformation (body.Instructions [0], null) {
 				Variables = { new VariableDebugInformation (temp, "temp") }
 			};
 
@@ -476,5 +475,15 @@ public void TypeNameExceedingMaxPdbPath ()
 				Assert.IsTrue (module.HasSymbols);
 			}, symbolReaderProvider: typeof (NativePdbReaderProvider), symbolWriterProvider: typeof (NativePdbWriterProvider));
 		}
+
+		[Test]
+		public void ReadPdbMixedNativeCLIModule ()
+		{
+			// MixedNativeCLI.exe was copy/pasted from from https://docs.microsoft.com/en-us/cpp/preprocessor/managed-unmanaged?view=msvc-170#example
+			TestModule ("MixedNativeCLI.exe", module => {
+				module.ReadSymbols ();
+			}, readOnly: true);
+		}
+
 	}
 }

symbols/pdb/Test/Resources/assemblies/MixedNativeCLI.exe.metagen

@@ -0,0 +1,5 @@
+ImageRuntimeVersion: v4.0.30319
+Assembly MixedNativeCLI, Version=0.0.*, Culture=Invariant Language (Invariant Country): 
+	hash=SHA1, flags=PublicKey
+Assembly mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089: 
+	hash=None, flags=None