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;
}
bool
ValueLocation::SetTo(const ValueLocation& other, uint64 bitOffset,
uint64 bitSize)
{
Clear();
fBigEndian = other.fBigEndian;
// compute the total bit size
int32 count = other.CountPieces();
uint64 totalBitSize = 0;
for (int32 i = 0; i < count; i++) {
const ValuePieceLocation &piece = other.PieceAt(i);
totalBitSize += piece.bitSize;
}
// adjust requested bit offset/size to something reasonable, if necessary
if (bitOffset + bitSize > totalBitSize) {
if (bitOffset >= totalBitSize)
return true;
bitSize = totalBitSize - bitOffset;
}
if (fBigEndian) {
// Big endian: Skip the superfluous most significant bits, copy the
// pieces we need (cutting the first and the last one as needed) and
// ignore the remaining pieces.
// skip pieces for the most significant bits we don't need anymore
uint64 bitsToSkip = bitOffset;
int32 i;
ValuePieceLocation piece;
for (i = 0; i < count; i++) {
const ValuePieceLocation& tempPiece = other.PieceAt(i);
if (tempPiece.bitSize > bitsToSkip) {
if (!piece.Copy(tempPiece))
return false;
break;
}
bitsToSkip -= tempPiece.bitSize;
}
// handle partial piece
if (bitsToSkip > 0) {
piece.bitOffset += bitsToSkip;
piece.bitSize -= bitsToSkip;
piece.Normalize(fBigEndian);
}
// handle remaining pieces
while (bitSize > 0) {
if (piece.bitSize > bitSize) {
// the piece is bigger than the remaining size -- cut it
piece.bitSize = bitSize;
piece.Normalize(fBigEndian);
bitSize = 0;
} else
bitSize -= piece.bitSize;
if (!AddPiece(piece))
return false;
if (++i >= count)
break;
if (!piece.Copy(other.PieceAt(i)))
return false;
}
} else {
// Little endian: Skip the superfluous least significant bits, copy the
// pieces we need (cutting the first and the last one as needed) and
// ignore the remaining pieces.
// skip pieces for the least significant bits we don't need anymore
uint64 bitsToSkip = totalBitSize - bitOffset - bitSize;
int32 i;
ValuePieceLocation piece;
for (i = 0; i < count; i++) {
const ValuePieceLocation& tempPiece = other.PieceAt(i);
if (tempPiece.bitSize > bitsToSkip) {
if (!piece.Copy(tempPiece))
return false;
break;
}
bitsToSkip -= piece.bitSize;
}
// handle partial piece
if (bitsToSkip > 0) {
piece.bitSize -= bitsToSkip;
piece.Normalize(fBigEndian);
}
// handle remaining pieces
while (bitSize > 0) {
if (piece.bitSize > bitSize) {
// the piece is bigger than the remaining size -- cut it
piece.bitOffset += piece.bitSize - bitSize;
piece.bitSize = bitSize;
piece.Normalize(fBigEndian);
bitSize = 0;
} else
bitSize -= piece.bitSize;
if (!AddPiece(piece))
return false;
if (++i >= count)
break;
if (!piece.Copy(other.PieceAt(i)))
return false;
}
}
return true;
}
