protected static void ConvertAlloca <TConstructionData>(
SSARewriterContext <Value> context,
TConstructionData data,
Alloca alloca,
Value initValue)
where TConstructionData : IConstructionData
{
alloca.Assert(data.ContainsAlloca(alloca));
// Bind the init value and remove the allocation from the block
context.SetValue(context.Block, alloca, initValue);
data.AddConverted(alloca, new FieldRef(alloca));
context.Remove(alloca);
}
/// <summary>
/// Converts an alloca node to its initial SSA value.
/// </summary>
private static void Convert <TConstructionData>(
SSARewriterContext <Value> context,
TConstructionData data,
Alloca alloca)
where TConstructionData : IConstructionData
{
if (!data.ContainsAlloca(alloca))
{
return;
}
alloca.Assert(!alloca.IsSimpleAllocation);
// Get the builder and the associated array length value
var builder = context.Builder;
var arrayLengthValue = alloca.ArrayLength.ResolveAs <PrimitiveValue>();
alloca.AssertNotNull(arrayLengthValue);
int arrayLength = arrayLengthValue.Int32Value;
// Create a structure with the appropriate number of fields that correspond
// to the current array length
var allocaTypeBuilder = builder.CreateStructureType(arrayLength + 1);
// Append array length
allocaTypeBuilder.Add(builder.GetPrimitiveType(BasicValueType.Int32));
// Append all virtual fields
for (int i = 0; i < arrayLength; ++i)
{
allocaTypeBuilder.Add(alloca.AllocaType);
}
var allocationType = allocaTypeBuilder.Seal();
// Initialize the structure value
var initValue = builder.CreateNull(alloca.Location, allocationType);
// ... and set the array length
initValue = builder.CreateSetField(
alloca.Location,
initValue,
new FieldSpan(new FieldAccess(0)),
builder.CreateConvertToInt32(alloca.Location, arrayLengthValue));
ConvertAlloca(context, data, alloca, initValue);
}