public override List <string> ExecuteSemanticAction(Stack <SemanticRecord> semanticRecordTable, Stack <SymbolTable> symbolTable, IToken lastToken)
{
Variable variable = new Variable();
List <string> errors = new List <string>();
while (semanticRecordTable.Peek().recordType == RecordTypes.IdName ||
semanticRecordTable.Peek().recordType == RecordTypes.TypeName ||
semanticRecordTable.Peek().recordType == RecordTypes.Size)
{
SemanticRecord topRecord = semanticRecordTable.Pop();
switch (topRecord.recordType)
{
case RecordTypes.Size:
variable.AddDimension(int.Parse(topRecord.getValue()));
break;
case RecordTypes.IdName:
variable.SetName(topRecord.getValue());
break;
case RecordTypes.TypeName:
variable.SetType(topRecord.getType());
SemanticRecord variableRecord = new SemanticRecord(variable);
semanticRecordTable.Push(variableRecord);
break;
default:
// This should only occur if the grammar is not valid
errors.Add("Grammar error, parsed rule that placed unexpected character on semantic stack");
break;
}
}
return(errors);
}
public override List <string> ExecuteSemanticAction(Stack <SemanticRecord> semanticRecordTable, Stack <SymbolTable> symbolTable, IToken lastToken, MoonCodeResult moonCode)
{
SymbolTable currentTable = symbolTable.Peek();
// Get the last created variable
SemanticRecord variableRecord = semanticRecordTable.Pop();
Entry variableEntry = new VarParamEntry(currentTable, variableRecord.getVariable(), EntryKinds.variable);
// Only declare variables for functions (not class member variables)
//if(currentTable.getParent() is FunctionEntry)
{
int size = variableRecord.getVariable().GetSize();
string address = variableEntry.getAddress();
if (size <= 0)
{
moonCode.AddGlobal(string.Format("% {0} res 0", address));
}
else if (size == 4)
{
moonCode.AddGlobal(string.Format("{0} dw 0", address));
}
else
{
moonCode.AddGlobal(string.Format("{0} res {1}{2}align", address, size, Environment.NewLine));
}
}
return(new List <string>());
}
public override List <string> ExecuteSemanticAction(Stack <SemanticRecord> semanticRecordTable, Stack <SymbolTable> symbolTable, IToken lastToken, MoonCodeResult moonCode)
{
SemanticRecord top = semanticRecordTable.Pop();
List <string> errors = new List <string>();
LinkedList <ExpressionRecord> expressionParameters = new LinkedList <ExpressionRecord>();
// Collect parameter expressions until we hit the function's name
while (top.recordType != RecordTypes.IdNameReference)
{
if (top.recordType != RecordTypes.ExpressionType)
{
errors.Add(string.Format("Grammar error at {0}. Migrating a function call should only count parameters, found {1}", lastToken.getLine(), top.recordType.ToString()));
}
else
{
expressionParameters.AddFirst((ExpressionRecord)top);
}
top = semanticRecordTable.Pop();
}
// Create the new semantic record
semanticRecordTable.Push(new FunctionCallRecord(top.getValue(), expressionParameters));
return(errors);
}
public override List <string> ExecuteSemanticAction(Stack <SemanticRecord> semanticRecordTable, Stack <SymbolTable> symbolTable, IToken lastToken)
{
SymbolTable currentTable = symbolTable.Peek();
// Get the last created variable
SemanticRecord variableRecord = semanticRecordTable.Pop();
Entry variableEntry = new VarParamEntry(currentTable, variableRecord.getVariable(), EntryKinds.variable);
return(new List <string>());
}
public override List <string> ExecuteSemanticAction(Stack <SemanticRecord> semanticRecordTable, Stack <SymbolTable> symbolTable, IToken lastToken, MoonCodeResult moonCode)
{
LinkedList <ExpressionRecord> expressions = new LinkedList <ExpressionRecord>();
List <string> errors = new List <string>();
// Accumulate the last two expressions on the semantic stack
while (expressions.Count < 2)
{
if (!semanticRecordTable.Any())
{
errors.Add(string.Format("Grammar error: Not enough expressions to validate assignment at line {0}", lastToken.getLine()));
return(errors);
}
SemanticRecord lastRecord = semanticRecordTable.Pop();
if (lastRecord.recordType != RecordTypes.ExpressionType)
{
errors.Add(string.Format("Grammar error, expression validation at line {0} encountered an illegal record: \"{1}\"", lastToken.getLine(), lastRecord.recordType.ToString()));
continue;
}
expressions.AddLast((ExpressionRecord)lastRecord);
}
// The first expression is the value we are reading
// while the second one is the expression we are writing to
ExpressionRecord type1 = expressions.First.Value;
ExpressionRecord type2 = expressions.Last.Value;
if (type1.GetExpressionType() != type2.GetExpressionType())
{
errors.Add(string.Format("Cannot equate at line {0} a value of type {1} to {2}", lastToken.getLine(), type1.GetExpressionType().getName(), type2.GetExpressionType().getName()));
}
SymbolTable currentScope = symbolTable.Peek();
string outAddress = string.Empty;
if (currentScope.getParent() == null)
{
errors.Add(string.Format("Cannot perform an assignment operation outside of a function"));
}
else
{
// Generate the code to read and store the value
moonCode.AddLine(currentScope.getParent().getAddress(), string.Format(@"
lw r2, {0}(r0)
sw {1}(r0), r2
", type1.GetAddress(), type2.GetAddress()));
}
return(errors);
}
public override List <string> ExecuteSemanticAction(Stack <SemanticRecord> semanticRecordTable, Stack <SymbolTable> symbolTable, IToken lastToken, MoonCodeResult moonCode)
{
SymbolTable currentTable = symbolTable.Peek();
LinkedList <Variable> foundParameters = new LinkedList <Variable>();
bool entryCreated = false;
string funcName = string.Empty;
List <string> errors = new List <string>();
// Iterate over the semantic stack and consume records relevant to this function
while (!entryCreated)
{
SemanticRecord topRecord = semanticRecordTable.Pop();
// Handle the record depending on its type
switch (topRecord.recordType)
{
case RecordTypes.Variable:
// Encountered paramenters
foundParameters.AddFirst(topRecord.getVariable());
break;
case RecordTypes.IdName:
// The name of this function
funcName = topRecord.getValue();
break;
case RecordTypes.TypeName:
// If we encounter a type we are done collecting and can create the entry
FunctionEntry funcEntry = new FunctionEntry(currentTable, funcName, topRecord.getType());
funcEntry.AddParameters(foundParameters);
// Push the function's scope to the stack of symbol tables
symbolTable.Push(funcEntry.getChild());
entryCreated = true;
break;
default:
// This should only fail if there is an error in the grammar.
errors.Add("Grammar error, parsed rule that placed unexpected character on semantic stack");
break;
}
}
return(errors);
}
public override List <string> ExecuteSemanticAction(Stack <SemanticRecord> semanticRecordTable, Stack <SymbolTable> symbolTable, IToken lastToken, MoonCodeResult moonCode)
{
int sizeCount = 0;
List <string> errors = new List <string>();
if (!semanticRecordTable.Any())
{
errors.Add(string.Format("Grammar error at line {0}: could not migrate variable for emtpy stack", lastToken.getLine()));
return(errors);
}
SemanticRecord top = semanticRecordTable.Pop();
// Accumulate indices until we hit the variable's name
while (top.recordType != RecordTypes.IdNameReference)
{
// Count the number of indices
sizeCount++;
if (top.recordType != RecordTypes.IndiceCount)
{
errors.Add(string.Format("Grammar error at {0}. Migrating a variable reference should only count indecies, found {1}", lastToken.getLine(), top.recordType.ToString()));
sizeCount--;
}
if (!semanticRecordTable.Any())
{
errors.Add(string.Format("Grammar error at {0}. Could not find Id name for variable", lastToken.getLine()));
break;
}
top = semanticRecordTable.Pop();
}
// Create the new semantic record
semanticRecordTable.Push(new VariableReferenceRecord(top.getValue(), sizeCount));
return(errors);
}
public override List <string> ExecuteSemanticAction(Stack <SemanticRecord> semanticRecordTable, Stack <SymbolTable> symbolTable, IToken lastToken, MoonCodeResult moonCode)
{
Stack <SemanticRecord> callChain = new Stack <SemanticRecord>();
List <string> errors = new List <string>();
if (!semanticRecordTable.Any())
{
errors.Add(string.Format("Grammar error at line {0}: could not verify factor for emtpy stack", lastToken.getLine()));
return(errors);
}
SemanticRecord lastRecord = semanticRecordTable.Pop();
// Accumulate semantic records until we reach the start of the factor
while (lastRecord.recordType != RecordTypes.FactorStart)
{
callChain.Push(lastRecord);
if (!semanticRecordTable.Any())
{
errors.Add(string.Format("Grammar error at {0}. Could not find start for a factor", lastToken.getLine()));
break;
}
lastRecord = semanticRecordTable.Pop();
}
SemanticRecord currentLink = callChain.Pop();
Entry linkedVariable = null;
// The first element in the chain is a reference to a locally accessible variable or function
// Go through symbol tables of increasing scope until we find the referenced identifier
foreach (SymbolTable table in symbolTable)
{
linkedVariable = table.GetEntries().FirstOrDefault(x => (x is VarParamEntry || x is FunctionEntry) && x.getName() == currentLink.getValue());
if (linkedVariable != null)
{
break;
}
}
// Verify the validity of this initial reference
bool success = VerifyLink(currentLink, linkedVariable, lastToken, errors);
// Go through the call chain and verify each link
while (callChain.Any() && success)
{
currentLink = callChain.Pop();
ClassEntry referredClass = ((VarParamEntry)linkedVariable).getVariable().getClass();
if (referredClass.getChild() == null)
{
errors.Add(string.Format("Identifier {0} cannot be reached at line {1}", currentLink.getValue(), lastToken.getLine()));
return(errors);
}
// Look in the referred class for the variable or function that is being referred to
linkedVariable = referredClass.getChild().GetEntries().FirstOrDefault(x => (x is VarParamEntry || x is FunctionEntry) && x.getName() == currentLink.getValue());
success = VerifyLink(currentLink, linkedVariable, lastToken, errors);
}
ClassEntry expressionType = new ClassEntry("undefined", 0);
// Find the linked variable and create a new expression for it
if (linkedVariable is VarParamEntry)
{
expressionType = ((VarParamEntry)linkedVariable).getVariable().getClass();
}
else if (linkedVariable is FunctionEntry)
{
expressionType = ((FunctionEntry)linkedVariable).GetReturnType();
}
if (linkedVariable == null)
{
errors.Add(string.Format("Grammar error: Could not link variable at line {0}", lastToken.getLine()));
}
else
{
semanticRecordTable.Push(new ExpressionRecord(expressionType, linkedVariable.getAddress()));
}
return(errors);
}
// A helper function to verify that a reference to a variable or function
// as the correct indicies or parameters
private bool VerifyLink(SemanticRecord currentLink, Entry linkedVariable, IToken lastToken, List <string> errors)
{
if (linkedVariable == null)
{
errors.Add(string.Format("Undefined identifier {0} at line {1}", currentLink.getValue(), lastToken.getLine()));
return(false);
}
if (linkedVariable is VarParamEntry && currentLink is FunctionCallRecord)
{
errors.Add(string.Format("Identifier {0} at line {1} is referring to a variable like a function", currentLink.getValue(), lastToken.getLine()));
return(false);
}
else if (linkedVariable is FunctionEntry && currentLink is VariableReferenceRecord)
{
errors.Add(string.Format("Identifier {0} at line {1} is referring to a function like a variable", currentLink.getValue(), lastToken.getLine()));
return(false);
}
// Verify that a variable is being accessed with the correct number of indices
if (currentLink is VariableReferenceRecord)
{
if (((VarParamEntry)linkedVariable).getVariable().GetDimensions().Count != ((VariableReferenceRecord)currentLink).getDimensions())
{
errors.Add(string.Format("Identifier {0} at line {1} does not have the correct number of indices. Counted {2} expected {3}"
, currentLink.getValue(), lastToken.getLine(), ((VariableReferenceRecord)currentLink).getDimensions(), ((VarParamEntry)linkedVariable).getVariable().GetDimensions().Count));
return(false);
}
return(true);
}
else if (currentLink is FunctionCallRecord)
{
var parameters = GetParameters(linkedVariable as FunctionEntry);
// Verify the number of paramters
if (parameters.Count() != ((FunctionCallRecord)currentLink).GetParameterCount())
{
errors.Add(string.Format("Function call {0} at line {1} does not have the correct number of parameters. Counted {2} expected {3}"
, currentLink.getValue(), lastToken.getLine(), ((FunctionCallRecord)currentLink).GetParameterCount(), parameters.Count()));
return(false);
}
else
{
var parameterComparers = parameters.Zip(((FunctionCallRecord)currentLink).GetParameters(), (f, a) => new { aparam = a, fparam = (VarParamEntry)f });
// Verify that the parameters are of the correct type
foreach (var parameterCompare in parameterComparers)
{
if (parameterCompare.aparam.GetExpressionType() != parameterCompare.fparam.getVariable().getClass())
{
errors.Add(string.Format("Cannot convert {0} to {1} in parameter at line {2}"
, parameterCompare.aparam.GetExpressionType().getName(), parameterCompare.fparam.getVariable().getClass().getName(), lastToken.getLine()));
}
}
}
return(true);
}
else
{
errors.Add("Grammar error: Illegal record on semantic stack");
return(false);
}
}
public override List <string> ExecuteSemanticAction(Stack <SemanticRecord> semanticRecordTable, Stack <SymbolTable> symbolTable, IToken lastToken, MoonCodeResult moonCode)
{
Token op = null;
LinkedList <ExpressionRecord> expressions = new LinkedList <ExpressionRecord>();
List <string> errors = new List <string>();
// Accumulate the two last expressions on the semantic stack
while (expressions.Count < 2)
{
if (!semanticRecordTable.Any())
{
errors.Add(string.Format("Grammar error: Not enough expressions to validate arithmetic operation at line {0}", lastToken.getLine()));
return(errors);
}
SemanticRecord record = semanticRecordTable.Pop();
BasicTokenRecord tokenRec = record as BasicTokenRecord;
if (tokenRec != null)
{
// Save the token representing the operation
op = tokenRec.getToken();
continue;
}
if (record is ExpressionRecord)
{
expressions.AddLast(record as ExpressionRecord);
}
else
{
errors.Add(string.Format("Grammar error: record {0} at line {1} is not allowed during an arithmetic expression validation", record.recordType.ToString(), lastToken.getLine()));
}
}
ExpressionRecord type1 = expressions.Last.Value;
ExpressionRecord type2 = expressions.First.Value;
// Ensure that both expressions are integers
if (type1.GetExpressionType() != AddTypeToList.intClass || type2.GetExpressionType() != AddTypeToList.intClass)
{
errors.Add(string.Format("Cannot perform arithmetic operation at line {0} between factors of type {1} and {2}"
, lastToken.getLine(), type1.GetExpressionType().getName(), type2.GetExpressionType().getName()));
}
SymbolTable currentScope = symbolTable.Peek();
string outAddress = string.Empty;
if (currentScope.getParent() == null)
{
errors.Add(string.Format("Cannot perform an arithemetic operation outside of a function"));
}
else if (op == TokenList.And || op == TokenList.Or)
{
// Generate an address for the result of this sub-expression
outAddress = Entry.MakeAddressForEntry(currentScope.getParent(), "arithmExpr");
// Get a unique id for the jump label
string jumpId = IDGenerator.GetNext();
// Generate the code to perform a logic "and" or "or" instead of bitwise
moonCode.AddGlobal(string.Format("{0} dw 0", outAddress));
moonCode.AddLine(currentScope.getParent().getAddress(), string.Format(@"
lw r3, {0}(r0)
lw r4, {1}(r0)
{2} r2, r3, r4
bz r2, zero_{4}
addi r2, r0, 1
sw {3}(r0), r2
j endop_{4}
zero_{4} sw {3}(r0), r0
endop_{4}
", type1.GetAddress(), type2.GetAddress(), opLists[op], outAddress, jumpId));
}
else
{
// Generate an address for the result of this sub-expression
outAddress = Entry.MakeAddressForEntry(currentScope.getParent(), "arithmExpr");
// Generate code for a mathematical or relational expression
moonCode.AddGlobal(string.Format("{0} dw 0", outAddress));
moonCode.AddLine(currentScope.getParent().getAddress(), string.Format(@"
lw r3, {0}(r0)
lw r4, {1}(r0)
{2} r2, r3, r4
sw {3}(r0), r2
", type1.GetAddress(), type2.GetAddress(), opLists[op], outAddress));
}
// Place the resulting expression on the semantic stack
semanticRecordTable.Push(new ExpressionRecord(AddTypeToList.intClass, outAddress));
return(errors);
}
