/// <summary>
/// Replaces the intrinsic call site
/// </summary>
/// <param name="context">The context.</param>
/// <param name="typeSystem">The type system.</param>
void IIntrinsicMethod.ReplaceIntrinsicCall(Context context, ITypeSystem typeSystem, IList<RuntimeParameter> parameters)
{
SymbolOperand callTargetOperand = this.GetInternalAllocateStringCallTarget(typeSystem);
SymbolOperand methodTableOperand = new SymbolOperand(BuiltInSigType.IntPtr, StringClassMethodTableSymbolName);
Operand lengthOperand = context.Operand1;
Operand result = context.Result;
context.SetInstruction(IR.Instruction.CallInstruction, result, callTargetOperand, methodTableOperand, lengthOperand);
}
private Operand InsertLoadBeforeInstruction(Context context, string symbolName, SigType type)
{
Context before = context.InsertBefore();
Operand result = this.methodCompiler.CreateTemporary(type);
Operand op = new SymbolOperand(type, symbolName);
before.SetInstruction(Instruction.Get(OpCode.Ldc_i4), result, op);
return result;
}
/// <summary>
/// Calls the specified target.
/// </summary>
/// <param name="symbolOperand">The symbol operand.</param>
public void Call(SymbolOperand symbolOperand)
{
linker.Link(
LinkType.RelativeOffset | LinkType.NativeI4,
compiler.Method.ToString(),
(int)(codeStream.Position - codeStreamBasePosition),
(int)(codeStream.Position - codeStreamBasePosition) + 4,
symbolOperand.Name,
IntPtr.Zero
);
codeStream.Position += 4;
}
/// <summary>
/// Visitation function for Ldstr instruction.
/// </summary>
/// <param name="context">The context.</param>
public void Ldstr(Context context)
{
/*
* This requires a special memory layout for strings as they are interned by the compiler
* into the generated image. This won't work this way forever: As soon as we'll support
* a real AppDomain and real string interning, this code will have to go away and will
* be replaced by a proper VM call.
*
*/
IAssemblyLinker linker = methodCompiler.Linker;
IMetadataModule assembly = methodCompiler.Assembly;
string referencedString = assembly.Metadata.ReadUserString(context.TokenType);
string symbolName = @"$ldstr$" + assembly.Name + "$String" + context.TokenType.ToString("x");
if (!linker.HasSymbol(symbolName))
{
// HACK: These strings should actually go into .rodata, but we can't link that right now.
using (Stream stream = linker.Allocate(symbolName, SectionKind.Text, 0, nativePointerAlignment))
{
// Method table and sync block
linker.Link(LinkType.AbsoluteAddress | LinkType.NativeI4, symbolName, 0, 0, @"System.String$mtable", IntPtr.Zero);
stream.WriteZeroBytes(8);
// String length field
stream.Write(BitConverter.GetBytes(referencedString.Length), 0, nativePointerSize);
// String data
byte[] stringData = Encoding.Unicode.GetBytes(referencedString);
Debug.Assert(stringData.Length == referencedString.Length * 2, @"Byte array of string data doesn't match expected string data length");
stream.Write(stringData);
}
}
Operand source = new SymbolOperand(BuiltInSigType.String, symbolName);
Operand destination = context.Result;
context.SetInstruction(IRInstruction.Move, destination, source);
}