Fix #346: incorrect type inference for if statement on ref bool parameter

ICSharpCode.Decompiler/ILAst/TypeAnalysis.cs

@@ -385,23 +385,29 @@ namespace ICSharpCode.Decompiler.ILAst
 				case ILCode.Ldobj:
 					{
 						TypeReference type = (TypeReference)expr.Operand;
-						if (expectedType != null) {
-							int infoAmount = GetInformationAmount(expectedType);
+						var argType = InferTypeForExpression(expr.Arguments[0], null);
+						if (argType is PointerType || argType is ByReferenceType) {
+							var elementType = ((TypeSpecification)argType).ElementType;
+							int infoAmount = GetInformationAmount(elementType);
 							if (infoAmount == 1 && GetInformationAmount(type) == 8) {
 								// A bool can be loaded from both bytes and sbytes.
-								type = expectedType;
+								type = elementType;
 							}
 							if (infoAmount >= 8 && infoAmount <= 64 && infoAmount == GetInformationAmount(type)) {
 								// An integer can be loaded as another integer of the same size.
 								// For integers smaller than 32 bit, the signs must match (as loading performs sign extension)
-								if (infoAmount >= 32 || IsSigned(expectedType) == IsSigned(type))
-									type = expectedType;
+								bool? elementTypeIsSigned = IsSigned(elementType);
+								bool? typeIsSigned = IsSigned(type);
+								if (elementTypeIsSigned != null && typeIsSigned != null) {
+									if (infoAmount >= 32 || elementTypeIsSigned == typeIsSigned)
+										type = elementType;
+								}
 							}
 						}
-						if (forceInferChildren) {
-							if (InferTypeForExpression(expr.Arguments[0], new ByReferenceType(type)) is PointerType)
-								InferTypeForExpression(expr.Arguments[0], new PointerType(type));
-						}
+						if (argType is PointerType)
+							InferTypeForExpression(expr.Arguments[0], new PointerType(type));
+						else
+							InferTypeForExpression(expr.Arguments[0], new ByReferenceType(type));
 						return type;
 					}
 				case ILCode.Stobj:

ICSharpCode.Decompiler/Tests/UnsafeCode.cs

@@ -33,6 +33,21 @@ public class UnsafeCode
 		return *(long*)(&d);
 	}
 	
+	public unsafe double ConvertLongToDouble(long d)
+	{
+		return *(double*)(&d);
+	}
+	
+	public unsafe int ConvertFloatToInt(float d)
+	{
+		return *(int*)(&d);
+	}
+	
+	public unsafe float ConvertIntToFloat(int d)
+	{
+		return *(float*)(&d);
+	}
+	
 	public unsafe void PassRefParameterAsPointer(ref int p)
 	{
 		fixed (int* ptr = &p)
@@ -48,7 +63,8 @@ public class UnsafeCode
 	
 	public unsafe void AddressInMultiDimensionalArray(double[,] matrix)
 	{
-		fixed (double* ptr = &matrix[1, 2]) {
+		fixed (double* ptr = &matrix[1, 2])
+		{
 			this.PointerReferenceExpression(ptr);
 		}
 	}
@@ -58,7 +74,7 @@ public class UnsafeCode
 		fixed (char* ptr = text)
 		{
 			char* ptr2 = ptr;
-			while (*ptr2 != 0)
+			while (*ptr2 != '\0')
 			{
 				*ptr2 = 'A';
 				ptr2++;
@@ -68,7 +84,7 @@ public class UnsafeCode
 	
 	public unsafe void PutDoubleIntoLongArray1(long[] array, int index, double val)
 	{
-		fixed (long* ptr = array) 
+		fixed (long* ptr = array)
 		{
 			((double*)ptr)[index] = val;
 		}
@@ -76,7 +92,7 @@ public class UnsafeCode
 	
 	public unsafe void PutDoubleIntoLongArray2(long[] array, int index, double val)
 	{
-		fixed (long* ptr = &array[index]) 
+		fixed (long* ptr = &array[index])
 		{
 			*(double*)ptr = val;
 		}
@@ -89,7 +105,7 @@ public class UnsafeCode
 	
 	public unsafe void FixMultipleStrings(string text)
 	{
-		fixed (char* ptr = text, userName = Environment.UserName, ptr2 = text) 
+		fixed (char* ptr = text, userName = Environment.UserName, ptr2 = text)
 		{
 			*ptr = 'c';
 			*userName = 'd';
@@ -100,7 +116,7 @@ public class UnsafeCode
 	public unsafe string StackAlloc(int count)
 	{
 		char* ptr = stackalloc char[count];
-		for (int i = 0; i < count; i++) 
+		for (int i = 0; i < count; i++)
 		{
 			ptr[i] = (char)i;
 		}

ICSharpCode.Decompiler/Tests/ValueTypes.cs

@@ -160,4 +160,12 @@ public static class ValueTypes
 		s.SetField();
 		return p;
 	}
+	
+	public static void UseRefBoolInCondition(ref bool x)
+	{
+		if (x) 
+		{
+			Console.WriteLine("true");
+		}
+	}
 }