Merge pull request #413 from xamarin/null-check-arguments

Added null checks to arguments

Author: stephen-hawley

Dynamo/Dynamo.CSLang/CSFunctionCall.cs

@@ -67,6 +67,18 @@ public static CSLine FunctionCallLine (string identifier, bool isConstructor, pa
 				new CommaListElementCollection<CSBaseExpression> (parameters), isConstructor));
 		}
 
+		static CSIdentifier iNameOf = new CSIdentifier ("nameof");
+		
+		public static CSFunctionCall Nameof (CSIdentifier id)
+		{
+			return FooOf (iNameOf, id);
+		}
+
+		public static CSFunctionCall Nameof (string name)
+		{
+			return Nameof (new CSIdentifier (name));
+		}
+
 		static CSIdentifier iTypeof = new CSIdentifier ("typeof");
 
 		public static CSFunctionCall Typeof (Type t)
@@ -76,28 +88,27 @@ public static CSFunctionCall Typeof (Type t)
 
 		public static CSFunctionCall Typeof (string t)
 		{
-			CommaListElementCollection<CSBaseExpression> parms = new CommaListElementCollection<CSBaseExpression> ();
-			parms.Add (new CSIdentifier (t));
-			return new CSFunctionCall (iTypeof, parms, false);
+			return FooOf (iTypeof, new CSIdentifier (t));
 		}
 
 		public static CSFunctionCall Typeof (CSSimpleType t)
 		{
-			CommaListElementCollection<CSBaseExpression> parms = new CommaListElementCollection<CSBaseExpression> ();
-			parms.Add (new CSIdentifier (t.Name));
-			return new CSFunctionCall (iTypeof, parms, false);
+			return Typeof (t.Name);
 		}
 
-
 		static CSIdentifier iSizeof = new CSIdentifier ("sizeof");
 
 		public static CSFunctionCall Sizeof (CSBaseExpression expr)
 		{
-			CommaListElementCollection<CSBaseExpression> parms = new CommaListElementCollection<CSBaseExpression> ();
-			parms.Add (expr);
-			return new CSFunctionCall (iSizeof, parms, false);
+			return FooOf (iSizeof, expr);
 		}
 
+		static CSFunctionCall FooOf (CSIdentifier foo, CSBaseExpression parameter)
+		{
+			CommaListElementCollection<CSBaseExpression> parms = new CommaListElementCollection<CSBaseExpression> ();
+			parms.Add (parameter);
+			return new CSFunctionCall (foo, parms, false);
+		}
 	}
 
 }

Dynamo/Dynamo.CSLang/CSThrow.cs

@@ -34,6 +34,13 @@ public static CSLine ThrowLine<T> (T exType, string message) where T : Exception
 				args.Add (CSConstant.Val (message));
 			return ThrowLine (exType, args);
 		}
+
+		public static CSLine ThrowLine<T>(T exType, CSBaseExpression expr) where T : Exception
+		{
+			CommaListElementCollection<CSBaseExpression> args = new CommaListElementCollection<CSBaseExpression> ();
+			args.Add (Exceptions.ThrowOnNull (expr, nameof (expr)));
+			return ThrowLine (exType, args);
+		}
 	}
 }
 

SwiftReflector/MarshalEngine.cs

@@ -1600,6 +1600,9 @@ CSBaseExpression MarshalNominal (CSParameter p)
 			// someCallToAPinvoke(new IntPtr(nameSwiftDataPtr))
 			// ...
 
+			if (p.Name.Name != "this")
+				preMarshalCode.Add (ThrowOnNull (p.Name));
+
 			string nomDataPtrName = Uniqueify (String.Format ("{0}SwiftDataPtr", p.Name.Name), identifiersUsed);
 			identifiersUsed.Add (nomDataPtrName);
 			var enumDataPtr = new CSIdentifier (nomDataPtrName);
@@ -1612,6 +1615,18 @@ CSBaseExpression MarshalNominal (CSParameter p)
 			return new CSCastExpression ("IntPtr", enumDataPtr);
 		}
 
+		CSLine ThrowOnNull (CSIdentifier parameterName)
+		{
+			// code to generate:
+			// if (p == null)
+			//    throw new ArgumentNullException (nameof (p));
+
+			var ifTest = parameterName == CSConstant.Null;
+			var throwCall = CSThrow.ThrowLine (new ArgumentNullException (), CSFunctionCall.Nameof (parameterName));
+			var ifStatement = new CSIfElse (ifTest, CSCodeBlock.Create (throwCall), null);
+			return new CSLine (ifStatement, false);
+		}
+
 		CSBaseExpression MarshalClass (CSParameter p, NamedTypeSpec cl)
 		{
 
@@ -1631,7 +1646,9 @@ CSBaseExpression MarshalClass (CSParameter p, NamedTypeSpec cl)
 			// In the second case, we reassign the argument.
 
 			// I put all the swift_beginAccess/swift_endAccess code into
-			// StructMarshal.   
+			// StructMarshal.
+			if (p.Name.Name != "this")
+				preMarshalCode.Add (ThrowOnNull (p.Name));
 
 			var fullClassName = cl.Name;
 			var backingFieldAccessor = NewClassCompiler.SafeBackingFieldAccessor (p.Name, use, fullClassName, typeMapper);

SwiftRuntimeLibrary.Mac/SwiftRuntimeLibrary.Mac.csproj

@@ -211,8 +211,8 @@
     <Compile Include="..\SwiftRuntimeLibrary\SwiftCharacter.cs">
       <Link>SwiftCharacter.cs</Link>
     </Compile>
-    <Compile Include="..\SwiftRuntimeLibrary\Extensions.cs">
-      <Link>Extensions.cs</Link>
+    <Compile Include="..\SwiftRuntimeLibrary\Exceptions.cs">
+      <Link>Exceptions.cs</Link>
     </Compile>
     <Compile Include="..\SwiftRuntimeLibrary\SwiftMarshal\ImportedTypeCache.cs">
       <Link>SwiftMarshal\ImportedTypeCache.cs</Link>

SwiftRuntimeLibrary.iOS/SwiftRuntimeLibrary.iOS.csproj

@@ -136,7 +136,7 @@
       <Link>SwiftMarshal\DynamicLib.cs</Link>
     </Compile>
     <Compile Include="..\SwiftRuntimeLibrary\SwiftMarshal\Extensions.cs">
-      <Link>SwiftMarshal\Extensions.cs</Link>
+      <Link>SwiftMarshal\Extentions.cs</Link>
     </Compile>
     <Compile Include="..\SwiftRuntimeLibrary\SwiftMarshal\Memory.cs">
       <Link>SwiftMarshal\Memory.cs</Link>
@@ -216,8 +216,8 @@
     <Compile Include="..\SwiftRuntimeLibrary\SwiftCharacter.cs">
       <Link>SwiftCharacter.cs</Link>
     </Compile>
-    <Compile Include="..\SwiftRuntimeLibrary\Extensions.cs">
-      <Link>Extensions.cs</Link>
+    <Compile Include="..\SwiftRuntimeLibrary\Exceptions.cs">
+      <Link>Exceptions.cs</Link>
     </Compile>
     <Compile Include="..\SwiftRuntimeLibrary\SwiftMarshal\ImportedTypeCache.cs">
       <Link>SwiftMarshal\ImportedTypeCache.cs</Link>

SwiftRuntimeLibrary/Extensions.cs SwiftRuntimeLibrary/Exceptions.csSwiftRuntimeLibrary/Extensions.cs renamed to SwiftRuntimeLibrary/Exceptions.cs

@@ -88,7 +88,7 @@
     <Compile Include="SwiftComparableProxy.cs" />
     <Compile Include="ISwiftComparable.cs" />
     <Compile Include="SwiftCharacter.cs" />
-    <Compile Include="Extensions.cs" />
+    <Compile Include="Exceptions.cs" />
     <Compile Include="SwiftMarshal\ImportedTypeCache.cs" />
     <Compile Include="..\tools\symbolicator\XamGlueConstants.cs">
       <Link>XamGlueConstants.cs</Link>

SwiftRuntimeLibrary/SwiftRuntimeLibrary.csproj

@@ -1468,6 +1468,36 @@ public init() {}
 			var callingCode = CSCodeBlock.Create (printer);
 			TestRunning.TestAndExecute (swiftCode, callingCode, "got here\n");
 		}
+
+		[Test]
+		public void DontPassMeNull ()
+		{
+			var swiftCode = @"
+public class EasyToRepresent
+{
+	public init () {}
+}
+
+public func reportIt (a: EasyToRepresent) -> Bool {
+	return true;
+}
+";
+
+			// try {
+			//    TopLevelEntities.ReportIt (null);
+			// } catch (ArgumentNullException err) {
+			//    Console.WriteLine("Here." + err.Message);
+			// }
+
+			var errID = new CSIdentifier ("err");
+			var callIt = CSFunctionCall.FunctionCallLine ("TopLevelEntities.ReportIt", false, CSConstant.Null);
+			var printer = CSFunctionCall.ConsoleWriteLine (CSConstant.Val ("Here.") + errID.Dot(new CSIdentifier ("Message")));
+			var tryCatch = new CSTryCatch (CSCodeBlock.Create (callIt),
+				typeof (ArgumentNullException), errID.Name, CSCodeBlock.Create (printer));
+			var callingCode = CSCodeBlock.Create (tryCatch);
+
+			TestRunning.TestAndExecute (swiftCode, callingCode, "Here.Value cannot be null.\nParameter name: a\n");
+		}
 	}
 }