private void PrintSequentiallyLaidOutField(PrintContext context, int index, ref int currentOffset)
{
Debug.Assert(!isExplicitLayout);
// sequential layout - no unions should be needed; however if the size
// is "odd", we are in pragma pack (1) and the packing will be simulated
// by our artificial padding fields
if (!unalignedSizeOrOffsets)
{
context.SetPack(this.pack);
}
NativeField nf = fields[index];
int previous_offset = currentOffset;
AlignField(nf, ref currentOffset, true);
if (unalignedSizeOrOffsets)
{
// inject artificial padding
context.PrintPadding(currentOffset - previous_offset);
}
context.Printer.PrintLn();
nf.PrintTo(context.Printer, context.LogPrinter, context.Flags);
currentOffset += nf.Type.TypeSize;
}
private void PrintUnionField(PrintContext context, int fieldIndex, int unionOffset)
{
NativeField nf = fields[fieldIndex];
if (nf.Offset.Value == unionOffset)
{
// no padding necessary - print the field
context.Printer.PrintLn();
nf.PrintTo(context.Printer, context.LogPrinter, context.Flags);
}
else
{
// this field will be wrapped in a struct with a padding before it
if (IsPragmaPack1Needed(nf.Offset.Value, unionOffset))
{
context.SetPack(1);
}
context.Printer.PrintLn();
context.Printer.PrintLn(OutputType.Keyword, "struct");
context.Printer.Print(OutputType.Operator, "{");
context.Printer.Indent();
try
{
// add padding
context.PrintPadding(nf.Offset.Value - unionOffset);
context.Printer.PrintLn();
// add the field itself
nf.PrintTo(context.Printer, context.LogPrinter, context.Flags);
}
finally
{
context.Printer.Unindent();
context.Printer.PrintLn();
context.Printer.Print(OutputType.Operator, "};");
}
}
}
private void PrintExplicitlyLaidOutField(PrintContext context, ref int index, ref int currentOffset)
{
Debug.Assert(isExplicitLayout);
NativeField nf = fields[index];
int start = (nf.Offset ?? currentOffset);
Debug.Assert(start >= currentOffset); // otherwise we would have printed it before
bool pack1 = false;
if (start > currentOffset)
{
if (IsPragmaPack1Needed(start))
{
context.SetPack(1);
pack1 = true;
}
// there is a gap between the end of last field and start of this field
context.PrintPadding(start - currentOffset);
currentOffset = start;
}
if (!pack1 && !unalignedSizeOrOffsets)
{
context.SetPack(DefaultPack);
}
// determine the fields that will have to be grouped in a union
int union_end;
int last_united_index = ComputeLastUnitedField(index, out union_end);
if (last_united_index > index)
{
context.Printer.PrintLn();
context.Printer.Print(OutputType.Keyword, "union");
if (isUnion)
{
PrintIdentifierAndSize(context);
}
else
{
context.Printer.PrintLn();
}
context.Printer.Print(OutputType.Operator, "{");
context.Printer.Indent();
try
{
for (int j = index; j <= last_united_index; j++)
{
// the union field will be the field itself or an anonymous
// structure if a padding is needed to reach the field offset
PrintUnionField(context, j, currentOffset);
}
}
finally
{
context.Printer.Unindent();
context.Printer.PrintLn();
context.Printer.Print(OutputType.Operator, "};");
}
}
else
{
// no union is needed
context.Printer.PrintLn();
nf.PrintTo(context.Printer, context.LogPrinter, context.Flags);
}
currentOffset = union_end;
index = last_united_index;
}
public override void PrintTo(ICodePrinter printer, ILogPrinter logPrinter, PrintFlags flags)
{
Debug.Assert(printer != null && logPrinter != null);
base.PrintTo(printer, logPrinter, flags);
PrintContext context = new PrintContext(printer, logPrinter, flags);
if (unalignedSizeOrOffsets)
{
// the size of the structure or field offsets is "odd" -> need to pragma pack (1) it
context.SetPack(1, true);
}
else
{
context.SetPack(DefaultPack, true);
}
if (!isUnion)
{
printer.PrintLn();
printer.Print(OutputType.Keyword, "struct");
PrintIdentifierAndSize(context);
printer.Print(OutputType.Operator, "{");
printer.Indent();
}
try
{
if (!isInvalid)
{
int current_offset = 0;
for (int i = 0; i < fields.Length; i++)
{
if (isExplicitLayout)
{
// this may in fact print more fields in a union, so i is passed byref
PrintExplicitlyLaidOutField(context, ref i, ref current_offset);
}
else
{
PrintSequentiallyLaidOutField(context, i, ref current_offset);
}
}
int tmp_offset = current_offset;
if (!context.UsedNonDefaultPack)
{
// if we never used a pack different from the default (8), we are sure
// about the implicit padding at the end of the structure
AlignSelf(ref tmp_offset);
}
if (size != tmp_offset)
{
// add final padding to the end of the structure to make its size exactly as requested
context.PrintPadding(size - current_offset, context.UsedNonDefaultPack);
}
}
}
finally
{
if (!isUnion)
{
printer.Unindent();
printer.PrintLn();
printer.Print(OutputType.Operator, "};");
}
context.SetDefaultPack();
}
}