/// <summary>
/// <para>封装了加载 int 类型数据到计算堆栈的方法</para>
/// <para>使用该方法，可以不考虑value范围而快捷方便的加载int类型数据到计算堆栈</para>
/// </summary>
/// <param name="writer">MSIL写入器</param>
/// <param name="value">将类型为<see cref="Int32"/>的值加载到计算堆栈上.</param>
/// <exception cref="ArgumentNullException">
/// <para><paramref name="writer"/> 是 <see langword="null"/>.</para>
/// </exception>
public static void EmitLdcI4(this ICILWriter writer, int value)
{
if (writer == null)
{
throw new ArgumentNullException("writer");
}
OpCode opCode;
switch (value)
{
case -1: opCode = OpCodes.Ldc_I4_M1; break;
case 0: opCode = OpCodes.Ldc_I4_0; break;
case 1: opCode = OpCodes.Ldc_I4_1; break;
case 2: opCode = OpCodes.Ldc_I4_2; break;
case 3: opCode = OpCodes.Ldc_I4_3; break;
case 4: opCode = OpCodes.Ldc_I4_4; break;
case 5: opCode = OpCodes.Ldc_I4_5; break;
case 6: opCode = OpCodes.Ldc_I4_6; break;
case 7: opCode = OpCodes.Ldc_I4_7; break;
case 8: opCode = OpCodes.Ldc_I4_8; break;
default:
opCode = OpCodes.Ldc_I4;
//value <= byte.MaxValue 如果这样写会有BUG
//? OpCodes.Ldc_I4_S
//: OpCodes.Ldc_I4;
break;
}
switch (opCode.OperandType)
{
case OperandType.InlineNone:
writer.Emit(opCode);
break;
case OperandType.ShortInlineI:
writer.Emit(opCode, (byte)value);
break;
case OperandType.InlineI:
writer.Emit(opCode, value);
break;
default:
throw new InvalidOperationException("意外的 OperandType. 这表示有一个BUG，请修复.");
}
}
/// <summary>
/// <para>将位于特定索引处的局部变量的地址加载到计算堆栈上。注意：加载的是地址</para>
/// <para>根据localIndex发送<see langword="OpCodes.Ldloca"/>或 <see langword="OpCodes.Ldloca_S"/>指令</para>
/// <para><see langword="OpCodes.Ldloca_S"/>指令可以高效的加载索引0-255的局部变量的地址</para>
/// </summary>
/// <param name="writer"></param>
/// <param name="localIndex">需要加载的局部变量的索引</param>
public static void EmitLdloca(this ICILWriter writer, int localIndex)
{
if (writer == null)
{
throw new ArgumentNullException("writer");
}
if (localIndex < 0)
{
throw new ArgumentOutOfRangeException("localIndex", "索引不是能负数");
}
if (localIndex <= byte.MaxValue)
{
writer.Emit(OpCodes.Ldloca_S, (byte)localIndex);
return;
}
writer.Emit(OpCodes.Ldloca, localIndex);
}
/// <summary>
/// Emits <see langword="OpCodes.Ldarga"/> or the best alternative macro depending on the operand.
/// </summary>
/// <param name="writer">The writer to write to.</param>
/// <param name="argumentIndex">The index of the parameter operand.</param>
public static void EmitLdarga(this ICILWriter writer, int argumentIndex)
{
if (writer == null)
{
throw new ArgumentNullException("writer");
}
if (argumentIndex < 0)
{
throw new ArgumentOutOfRangeException("argumentIndex", "argumentIndex may not be negative");
}
if (argumentIndex <= byte.MaxValue)
{
writer.Emit(OpCodes.Ldarga_S, (byte)argumentIndex);
return;
}
writer.Emit(OpCodes.Ldarga, argumentIndex);
}
/// <summary>
/// 用计算堆栈中的值替换给定索引处的数组元素，其类型在指令中指定。
/// </summary>
/// <param name="writer"></param>
/// <param name="elementType"></param>
internal static void EmitStelem(this ICILWriter writer, Type elementType)
{
OpCode opCode;
if (elementType.IsPrimitive && _primitiveStelemOpCodes.TryGetValue(elementType, out opCode))
{
writer.Emit(opCode);
return;
}
if (elementType.IsValueType || elementType.IsGenericParameter)
{
writer.Emit(OpCodes.Stelem, elementType);
}
else
{
writer.Emit(OpCodes.Stelem_Ref);
}
}
internal static void EmitStobj(this ICILWriter writer, Type type)
{
OpCode opCode;
if (type.IsPrimitive && _primitiveStobjOpCodes.TryGetValue(type, out opCode))
{
writer.Emit(opCode);
return;
}
if (type.IsValueType || type.IsGenericParameter)
{
writer.Emit(OpCodes.Stobj, type);
}
else
{
writer.Emit(OpCodes.Stind_Ref);
}
}
public static void EmitCall(this ICILWriter writer, MethodInfo method)
{
if (writer == null)
{
throw new ArgumentNullException("writer");
}
if (method == null)
{
throw new ArgumentNullException("method");
}
OpCode opCode = !method.IsStatic && method.IsVirtual ? OpCodes.Callvirt : OpCodes.Call;
writer.Emit(opCode, method);
}
/// <summary>
/// <para>将位于特定索引处的局部变量加载到计算堆栈上。注意：加载的是值</para>
/// </summary>
/// <param name="writer"></param>
/// <param name="localIndex">需要加载的局部变量的索引</param>
public static void EmitLdloc(this ICILWriter writer, int localIndex)
{
if (writer == null)
{
throw new ArgumentNullException("writer");
}
if (localIndex < 0)
{
throw new ArgumentOutOfRangeException("localIndex", "localIndex may not be negative");
}
switch (localIndex)
{
case 0:
writer.Emit(OpCodes.Ldloc_0);
return;
case 1:
writer.Emit(OpCodes.Ldloc_1);
return;
case 2:
writer.Emit(OpCodes.Ldloc_2);
return;
case 3:
writer.Emit(OpCodes.Ldloc_3);
return;
default:
if (localIndex <= byte.MaxValue)
{
//高效加载0-255索引处的变量
writer.Emit(OpCodes.Ldloc_S, (byte)localIndex);
return;
}
writer.Emit(OpCodes.Ldloc, localIndex);
return;
}
}
/// <summary>
/// 发送<see langword="OpCodes.Ldarg"/>指令，或者根据操作数，自动发射最佳的替代指令，例如OpCodes.Ldarg_3或pCodes.Ldarg_S
/// </summary>
public static void EmitLdarg(this ICILWriter writer, int argumentIndex)
{
if (writer == null)
{
throw new ArgumentNullException("writer");
}
if (argumentIndex < 0)
{
throw new ArgumentOutOfRangeException("argumentIndex", "argumentIndex may not be negative");
}
switch (argumentIndex)
{
case 0:
writer.Emit(OpCodes.Ldarg_0);
return;
case 1:
writer.Emit(OpCodes.Ldarg_1);
return;
case 2:
writer.Emit(OpCodes.Ldarg_2);
return;
case 3:
writer.Emit(OpCodes.Ldarg_3);
return;
default:
if (argumentIndex <= byte.MaxValue)
{
writer.Emit(OpCodes.Ldarg_S, (byte)argumentIndex);
return;
}
writer.Emit(OpCodes.Ldarg, argumentIndex);
return;
}
}
/// <summary>
/// 对bool取反；注意：在计算堆栈中，bool是以int存放的true:1,false:0
/// </summary>
/// <param name="w"></param>
private static void NotBoolean(ICILWriter w)
{
w.Emit(OpCodes.Not); CastBooleanInt(w);
}
/// <summary>
/// <para>转成bool类型对应的int值</para>
/// <para>false:0;true:1</para>
/// <para>0取反得到的数值是-1；1取反得到的数值是-2；因此，我们需要将-1转成1，把-2转成0，才能得到正确的bool对应的整数值</para>
/// </summary>
private static void CastBooleanInt(ICILWriter w)
{
w.Emit(OpCodes.Ldc_I4_1); w.Emit(OpCodes.And);
}