/// <summary>
/// Identifies the LocalVariableTable that defined the symbol reference.
/// </summary>
/// <param name="offset">Offset at which the symbol was referenced.</param>
/// <param name="symRef">Reference to symbol.</param>
/// <returns>Table index, or -1 if not found.</returns>
public int GetDefiningTableOffset(int offset, WeakSymbolRef symRef)
{
// symRef is the non-uniquified, non-de-duplicated symbol that was generated
// during the analysis pass. This matches the contents of the tables, so we don't
// need to transform it at all.
//
// Walk backward through the list of tables until we find a match.
IList <int> keys = mLvTables.Keys;
for (int i = keys.Count - 1; i >= 0; i--)
{
if (keys[i] > offset)
{
// table comes after the point of reference
continue;
}
if (mLvTables.Values[i].GetByLabel(symRef.Label) != null)
{
// found it
return(keys[i]);
}
}
// if we didn't find it, it doesn't exist... right?
Debug.Assert(mCurrentTable.GetByLabel(symRef.Label) == null);
return(-1);
}
/// <summary>
/// Gets the symbol associated with a symbol reference. If uniquification is enabled,
/// the unique-label map for the specified offset will be used to transform the
/// symbol reference.
/// </summary>
/// <param name="offset">Offset of start of instruction.</param>
/// <param name="symRef">Reference to symbol.</param>
/// <returns>Symbol, or null if no match found.</returns>
public DefSymbol GetSymbol(int offset, WeakSymbolRef symRef)
{
AdvanceToOffset(offset);
// The symRef uses the non-uniquified symbol, so we need to get the unique value at
// the current offset. We may need to do this even when variables can be
// redefined, because we might have a variable that's a duplicate of a user label
// or project symbol.
// Start by applying the de-duplication map.
string label = symRef.Label;
if (mDupRemap.TryGetValue(symRef.Label, out string remap))
{
label = remap;
}
//Debug.WriteLine("GetSymbol " + symRef.Label + " -> " + label);
if (mUniqueLabels != null && mUniqueLabels.TryGetValue(label, out UniqueLabel ulab))
{
//Debug.WriteLine(" Unique var " + symRef.Label + " -> " + ulab.Label);
label = ulab.Label;
}
DefSymbol defSym = mCurrentTable.GetByLabel(label);
// In theory this is okay, but in practice the only things asking for symbols are
// entirely convinced that the symbol exists here. So this is probably a bug.
Debug.Assert(defSym != null);
return(defSym);
}
/// <summary>
/// Identifies the LocalVariableTable that defined the symbol reference.
/// </summary>
/// <param name="offset">Offset at which the symbol was referenced.</param>
/// <param name="symRef">Reference to symbol.</param>
/// <returns>Table index, or -1 if not found.</returns>
public int GetDefiningTableOffset(int offset, WeakSymbolRef symRef)
{
// Get mDupRemap et. al. into the right state.
AdvanceToOffset(offset);
// symRef is the non-uniquified, de-duplicated symbol that was generated
// during the analysis pass. We either need to un-de-duplicate the label,
// or de-duplicate what we pull out of the Lv tables. The former requires
// a linear string search but will be faster if there are a lot of tables.
string label = UnDeDuplicate(symRef.Label);
// Walk backward through the list of tables until we find a match.
IList <int> keys = mLvTables.Keys;
for (int i = keys.Count - 1; i >= 0; i--)
{
if (keys[i] > offset)
{
// table comes after the point of reference
continue;
}
if (mLvTables.Values[i].GetByLabel(label) != null)
{
// found it
return(keys[i]);
}
}
// if we didn't find it, it doesn't exist... right?
Debug.Assert(mCurrentTable.GetByLabel(label) == null);
return(-1);
}
/// <summary>
/// Constructor for symbol item.
/// </summary>
/// <param name="length">Length, in bytes.</param>
/// <param name="sym">Weak symbol reference.</param>
/// <param name="isBigEndian">Set to true for big-endian data.</param>
private FormatDescriptor(int length, WeakSymbolRef sym, bool isBigEndian)
{
Debug.Assert(sym != null);
Debug.Assert(length > 0 && length <= MAX_NUMERIC_LEN);
Length = length;
FormatType = isBigEndian ? Type.NumericBE : Type.NumericLE;
FormatSubType = SubType.Symbol;
SymbolRef = sym;
}
public SerWeakSymbolRef(WeakSymbolRef weakSym)
{
Label = weakSym.Label;
Part = weakSym.ValuePart.ToString();
}
/// <summary>
/// Returns a descriptor with a symbol.
/// </summary>
/// <param name="length">Length, in bytes.</param>
/// <param name="sym">Weak symbol reference.</param>
/// <param name="isBigEndian">Set to true for big-endian data.</param>
/// <returns>New or pre-allocated descriptor.</returns>
public static FormatDescriptor Create(int length, WeakSymbolRef sym, bool isBigEndian)
{
DebugCreateCount++;
return(new FormatDescriptor(length, sym, isBigEndian));
}
