Esempio n. 1
0
status_t
DwarfType::ResolveLocation(DwarfTypeContext* typeContext,
	const LocationDescription* description, target_addr_t objectAddress,
	bool hasObjectAddress, ValueLocation& _location)
{
	status_t error = typeContext->File()->ResolveLocation(
		typeContext->GetCompilationUnit(), typeContext->AddressSize(),
		typeContext->SubprogramEntry(), description,
		typeContext->TargetInterface(), typeContext->InstructionPointer(),
		objectAddress, hasObjectAddress, typeContext->FramePointer(),
		typeContext->RelocationDelta(), _location);
	if (error != B_OK)
		return error;

	// translate the DWARF register indices and the bit offset/size semantics
	const Register* registers = typeContext->GetArchitecture()->Registers();
	bool bigEndian = typeContext->GetArchitecture()->IsBigEndian();
	int32 count = _location.CountPieces();
	for (int32 i = 0; i < count; i++) {
		ValuePieceLocation piece = _location.PieceAt(i);
		if (piece.type == VALUE_PIECE_LOCATION_REGISTER) {
			int32 reg = typeContext->FromDwarfRegisterMap()->MapRegisterIndex(
				piece.reg);
			if (reg >= 0) {
				piece.reg = reg;
				// The bit offset for registers is to the least
				// significant bit, while we want the offset to the most
				// significant bit.
				if (registers[reg].BitSize() > piece.bitSize) {
					piece.bitOffset = registers[reg].BitSize() - piece.bitSize
						- piece.bitOffset;
				}
			} else
				piece.SetToUnknown();
		} else if (piece.type == VALUE_PIECE_LOCATION_MEMORY) {
			// Whether the bit offset is to the least or most significant bit
			// is target architecture and source language specific.
			// TODO: Check whether this is correct!
			// TODO: Source language!
			if (!bigEndian && piece.size * 8 > piece.bitSize) {
				piece.bitOffset = piece.size * 8 - piece.bitSize
					- piece.bitOffset;
			}
		}

		piece.Normalize(bigEndian);
		_location.SetPieceAt(i, piece);
	}

	// If we only have one piece and that doesn't have a size, try to retrieve
	// the size of the type.
	if (count == 1) {
		ValuePieceLocation piece = _location.PieceAt(0);
		if (piece.IsValid() && piece.size == 0 && piece.bitSize == 0) {
			piece.SetSize(ByteSize());
				// TODO: Use bit size and bit offset, if specified!
			_location.SetPieceAt(0, piece);

			TRACE_LOCALS("  set single piece size to %" B_PRIu64 "\n",
				ByteSize());
		}
	}

	return B_OK;
}