/// <summary>
/// Extracts the constant from a condition
/// </summary>
/// <returns>The extracted variable</returns>
public int?GetConstFromCondition()
{
Validate();
System.Collections.Specialized.StringCollection refvarIDs = new System.Collections.Specialized.StringCollection();
Match matchResult = Regex.Match(TACtext, "ID_[A-F0-9]{8}(?:-[A-F0-9]{4}){3}-[A-F0-9]{12}", RegexOptions.None);
while (matchResult.Success)
{
refvarIDs.Add(matchResult.Value);
matchResult = matchResult.NextMatch();
}
if (refvarIDs.Count == 3)
{
return(null);
}
else
{
return(Convert.ToInt32(TACtext.Split(' ')[3]));
}
}
/// <summary>
/// Modifies the TAC text of instruction: replaces numerical constant to variable name
/// </summary>
/// <param name="variable">Variable containing constant</param>
/// <param name="value">Constant number to be replaced</param>
public void ModifyConstInstruction(Variable variable, int?value)
{
if (variable == null || value == null)
{
throw new ObjectException("Wrong parameter passing.");
}
RefVariables.Add(variable);
string TACtext_new = string.Empty;
for (int i = 0; i < TACtext.Split(' ').Length; i++)
{
if (TACtext.Split(' ')[i] != value.ToString())
{
TACtext_new = string.Join(" ", TACtext_new, TACtext.Split(' ')[i]);
}
else
{
TACtext_new = string.Join(" ", TACtext_new, variable.name);
}
}
TACtext = TACtext_new.Trim();
}
/// <summary>
/// Determines the new state of a dead variable (a pointer) as a result of the instruction
/// </summary>
/// <param name="variable">A variable or a pointer</param>
/// <returns>A list of states. For variable: 1 - variable, 2 - empty. For pointer: 1-pointer, 2 - variable. Empty list if nothing has changed.</returns>
public List <Variable.State> GetChangedStates(Variable variable)
{
if (string.IsNullOrWhiteSpace(TACtext))
{
throw new ObjectException("TAC text is empty. Instruction: " + ID);
}
if (RefVariables.Count == 0 || !RefVariables.Contains(variable))
{
throw new ObjectException("No referenced variables found in instruction " + ID);
}
List <Variable.State> var_states = new List <Variable.State>();
string right = string.Empty, left = string.Empty;
if (TACtext.Split('=').Length == 2)
{
right = TACtext.Split('=')[1];
left = TACtext.Split('=')[0];
}
switch (statementType)
{
case Common.StatementType.FullAssignment:
case Common.StatementType.UnaryAssignment:
case Common.StatementType.Copy:
if (Regex.IsMatch(right, variable.ID, RegexOptions.None) && !Regex.IsMatch(left, variable.ID, RegexOptions.None))
{
var_states.Add(Variable.State.Free);
}
else if (Regex.IsMatch(left, variable.ID, RegexOptions.None))
{
var_states.Add(Variable.State.Filled);
}
break;
case Common.StatementType.ConditionalJump:
var_states.Add(Variable.State.Free);
break;
case Common.StatementType.PointerAssignment:
if (left.Contains("&"))
{
throw new ObjectException("Instruction type '&a=p' is not supported. Please use 'p=&a' instead.");
}
else if (right.Contains("&"))
{
// Nothing changed
if (Regex.IsMatch(right, variable.ID, RegexOptions.None) && !variable.pointer)
{
break;
}
// Pointer is filled
else if (Regex.IsMatch(left, variable.ID, RegexOptions.None) && variable.pointer)
{
var_states.Add(Variable.State.Filled);
}
else
{
throw new ObjectException("GetChangedStates could not parse 'p=&a' instruction type. Possible errors: 'a' is a poiner; 'p' is not a pointer; incorrect TAC text.");
}
}
else if (left.Contains("*"))
{
// Variable state is free
if (Regex.IsMatch(right, variable.ID, RegexOptions.None) && !variable.pointer)
{
var_states.Add(Variable.State.Free);
}
// Pointer is free, variable is filled
else if (Regex.IsMatch(left, variable.ID, RegexOptions.None) && variable.pointer)
{
var_states.Add(Variable.State.Free);
var_states.Add(Variable.State.Filled);
}
else
{
throw new ObjectException("GetChangedStates could not parse '*p=a' instruction type. Possible error: 'a' is a poiner or 'p' is not a pointer; incorrect TAC text.");
}
}
else if (right.Contains("*"))
{
// Pointer is free, variable is free
if (Regex.IsMatch(right, variable.ID, RegexOptions.None) && variable.pointer)
{
var_states.Add(Variable.State.Free);
var_states.Add(Variable.State.Free);
}
// Variable is filled
else if (Regex.IsMatch(left, variable.ID, RegexOptions.None) && !variable.pointer)
{
var_states.Add(Variable.State.Filled);
}
else
{
throw new ObjectException("GetChangedStates could not parse 'a=*p' instruction type. Possible error: 'a' is a poiner or 'p' is not a pointer; incorrect TAC text.");
}
}
else
{
throw new ObjectException("GetChangedStates: problem in parsing TAC text of PointerAssignment instruction type. Instruction: " + ID);
}
break;
case Common.StatementType.IndexedAssignment:
throw new ObjectException("This statement type is not supported.");
case Common.StatementType.Procedural:
if (variable.pointer)
{
throw new ObjectException("GetChangedStates: pointers are not supported in Procedural instruction type.");
}
else if ((Regex.IsMatch(TACtext, "param", RegexOptions.None) || Regex.IsMatch(TACtext, "return", RegexOptions.None)) && Regex.IsMatch(TACtext, RefVariables[0].ID, RegexOptions.None))
{
var_states.Add(Variable.State.Free);
}
else if (Regex.IsMatch(TACtext, "retrieve", RegexOptions.None) && Regex.IsMatch(TACtext, RefVariables[0].ID, RegexOptions.None))
{
var_states.Add(Variable.State.Filled);
}
break;
case Common.StatementType.UnconditionalJump:
case Common.StatementType.NoOperation:
default:
throw new ObjectException("This statement type cannot change states of 'dead' variables.");
}
return(var_states);
}