private bool ParseNewExpression(TokenReader reader, out Expression expression)
{
expression = null;
Token start = reader.Peek();
if (!this.Expect(reader, Keyword.New))
{
return false;
}
TypeReference typeRef = null;
if (!this.ParseTypeReference(reader, out typeRef))
{
return false;
}
List<Expression> args = new List<Expression>();
Token tok = reader.Peek();
if (tok.Is(Keyword.LeftParen))
{
reader.Read();
tok = reader.Peek();
while (tok != null && !tok.Is(Keyword.RightParen))
{
Expression arg = null;
if (!this.ParseExpression(reader, out arg))
{
return false;
}
args.Add(arg);
tok = reader.Peek();
if (!tok.Is(Keyword.Comma))
{
break;
}
else
{
tok = reader.Read();
}
}
if (!this.Expect(reader, Keyword.RightParen))
{
return false;
}
}
expression = new NewExpression(start, typeRef, args);
return true;
}
private bool TryEmitNewExpression(
NewExpression newExpr,
CompilerContext context,
Scope scope,
MethodImpl method,
out TypeDefinition valueType)
{
valueType = null;
TypeDefinition objectType = null;
if (!this.TryResolveTypeReference(context, newExpr.Type, out objectType))
{
valueType = null;
return false;
}
if (!objectType.IsClass && newExpr.ConstructorArguments.Count() > 0)
{
log.Write(new Message(
newExpr.Start.Path,
newExpr.Start.Line,
newExpr.Start.Column,
Severity.Error,
Properties.Resources.CodeGenerator_ConstructorArgumentsAreOnlySupportedOnClassTypes));
return false;
}
valueType = context.GetPointerType(objectType);
if (!this.TryEmitAllocCall(newExpr.Start, context, scope, method, objectType.Size))
{
return false;
}
MethodInfo constructor = null;
int argSize = 0;
if (objectType.IsClass)
{
int nullTestStart = method.Statements.Count;
List<TypeDefinition> argTypes = new List<TypeDefinition>();
foreach (Expression arg in newExpr.ConstructorArguments.Reverse())
{
TypeDefinition argType = null;
if (!this.TryEmitExpression(arg, context, scope, method, out argType))
{
return false;
}
this.PushResult(method, argType);
argSize += ((argType.Size + 3) / 4) * 4;
argTypes.Insert(0, argType);
}
if (!context.TryFindConstructor(objectType, argTypes, out constructor))
{
// ok to have no default constructor
if (argTypes.Count > 0)
{
string message = string.Format(
System.Globalization.CultureInfo.CurrentCulture,
Properties.Resources.CodeGenerator_CannotFindConstructor,
objectType.FullName);
log.Write(new Message(
newExpr.Start.Path,
newExpr.Start.Line,
newExpr.Start.Column,
Severity.Error,
message));
return false;
}
}
if (constructor != null)
{
LocalVariable tempPtr = scope.DefineTempVariable(valueType);
string jumpLabel = method.Module.GetNextJumpLabel();
List<AsmStatement> saveAlloc = new List<AsmStatement>();
saveAlloc.Add(new AsmStatement { Instruction = string.Format("mov _{0}$[ebp],eax", tempPtr.Name) });
saveAlloc.Add(new AsmStatement { Instruction = "test eax,eax" });
saveAlloc.Add(new AsmStatement { Instruction = "jz " + jumpLabel });
method.Statements.InsertRange(nullTestStart, saveAlloc);
method.Statements.Add(new AsmStatement { Instruction = string.Format("mov eax,_{0}$[ebp]", tempPtr.Name) });
method.Statements.Add(new AsmStatement { Instruction = "push eax" });
method.Module.AddProto(constructor);
method.Statements.Add(new AsmStatement { Instruction = "call " + constructor.MangledName });
method.Statements.Add(new AsmStatement { Instruction = string.Format("add esp,{0}", argSize + 4) });
method.Statements.Add(new AsmStatement { Instruction = string.Format("mov eax,_{0}$[ebp]", tempPtr.Name), Label = jumpLabel });
}
}
return true;
}
