private TType ParseRecordType()
{
TType pType = new TType(TFormCode.fcRecord, 0, null);
symtabStack.EnterScope();
pType.record.pSymtab = symtabStack.CurrentSymtab;
GetToken();
ParseFieldDeclarations(pType, 0);
CondGetToken(TTokenCode.End, TErrorCode.MissingEND);
return pType;
}
private TType ParseSubrangeType(SymtabNode pMinId)
{
TType pType = new TType(TFormCode.fcSubrange, 0, null);
TType.SetType(ref pType.SubRange.BaseType,
ParseSubrangeLimit(pMinId, ref pType.SubRange.min));
Resync(tlSubrangeLimitFollow, tlDeclarationStart);
CondGetToken(TTokenCode.DotDot, TErrorCode.MissingDotDot);
TType pMaxType = ParseSubrangeLimit(null, ref pType.SubRange.max);
if (pMaxType != pType.SubRange.BaseType)
{
OnError(TErrorCode.IncompatibleTypes);
pType.SubRange.max = pType.SubRange.min;
}
else if (pType.SubRange.min > pType.SubRange.max)
{
OnError(TErrorCode.MinGtMax);
int temp = pType.SubRange.min;
pType.SubRange.min = pType.SubRange.max;
pType.SubRange.max = temp;
}
pType.size = pType.SubRange.BaseType.size;
return pType;
}
private SymtabNode ParseIdSublist(SymtabNode pRoutineId, TType pRecordType, out SymtabNode pLastId)
{
SymtabNode pId;
SymtabNode pFirstId = null;
pLastId = null;
// -- Loop to parse each identifier in the sublist.
while (token == TTokenCode.Identifier)
{
// -- Variable: Enter into local symbol table.
// -- Field: Enter into record symbol table.
pId = pRoutineId != null ? EnterNewLocal(pToken.TokenString)
: pRecordType.record.pSymtab.EnterNew(pToken.TokenString);
// -- Link newly-declared identifier nodes together
// -- into a sublist.
if (pId.defn.how == TDefnCode.dcUndefined)
{
pId.defn.how = pRoutineId != null ? TDefnCode.dcVariable : TDefnCode.dcField;
if (pFirstId == null) pFirstId = pLastId = pId;
else
{
pLastId.Next = pId;
pLastId = pId;
}
}
// -- ,
GetToken();
Resync(tlIdentifierFollow);
if (token == TTokenCode.Comma)
{
// -- Saw comma.
// -- Skip extra commas and look for an identifier
do
{
GetToken();
Resync(tlIdentifierStart, tlIdentifierFollow);
if (token == TTokenCode.Comma) OnError(TErrorCode.MissingIdentifier);
} while (token == TTokenCode.Comma);
}
}
return pFirstId;
}
private void ParseIndexType(TType pArrayType)
{
if (TokenIn(token, tlIndexStart))
{
TType pIndexType = ParseTypeSpec();
TType.SetType(ref pArrayType.array.pIndexType, pIndexType);
switch (pIndexType.Form)
{
case TFormCode.fcSubrange:
pArrayType.array.elmtCount =
pIndexType.SubRange.max -
pIndexType.SubRange.min + 1;
pArrayType.array.minIndex = pIndexType.SubRange.min;
pArrayType.array.maxIndex = pIndexType.SubRange.max;
return;
case TFormCode.fcArray:
pArrayType.array.elmtCount =
pIndexType.Enumeration.max + 1;
pArrayType.array.minIndex = 0;
pArrayType.array.maxIndex =
pIndexType.Enumeration.max;
return;
}
}
TType.SetType(ref pArrayType.array.pIndexType, TType.pDummyType);
pArrayType.array.elmtCount = 0;
pArrayType.array.minIndex = pArrayType.array.maxIndex = 0;
OnError(TErrorCode.InvalidIndexType);
}
//--------------------------------------------------------------
// CheckRelOpOperands Check that the types of the two operands
// of a relational operator are compatible.
// Flag an incompatible type error if not.
//
// pType1 : ptr to the first operand's type object
// pType2 : ptr to the second operand's type object
//--------------------------------------------------------------
/// <summary>
///--------------------------------------------------------------
/// CheckRelOpOperands Check that the types of the two operands
/// of a relational operator are compatible.
/// Flag an incompatible type error if not.
///
/// pType1 : ptr to the first operand's type object
/// pType2 : ptr to the second operand's type object
///--------------------------------------------------------------
/// </summary>
/// <param name="firstOperandType">The first operand's type object.</param>
/// <param name="secondOperandType">The second operand's type object.</param>
/// <returns></returns>
public static bool CheckRelOpOperands(TType firstOperandType, TType secondOperandType)
{
firstOperandType = firstOperandType.Base;
secondOperandType = secondOperandType.Base;
//--Two identical scalar or enumeration types.
if ((firstOperandType == secondOperandType)
&& ((firstOperandType.Form == TFormCode.fcScalar) || (firstOperandType.Form == TFormCode.fcEnum)))
{
return true;
}
//--One integer operand and one real operand.
if (((firstOperandType == pIntegerType) && (secondOperandType == pRealType))
|| ((secondOperandType == pIntegerType) && (firstOperandType == pRealType)))
{
return true;
}
//--Two strings of the same length.
if ((firstOperandType.Form == TFormCode.fcArray)
&& (secondOperandType.Form == TFormCode.fcArray)
&& (firstOperandType.array.pElmtType == pCharType)
&& (secondOperandType.array.pElmtType == pCharType)
&& (firstOperandType.array.elmtCount == secondOperandType.array.elmtCount))
{
return true;
}
return false;
}
private void ParseFieldDeclarations(TType pRecordType, int offset)
{
ParseVarOrFieldDecls(null, pRecordType, offset);
}
private static void RemoveType(ref TType pType)
{
if (pType != null && (--pType.refCount == 0))
{
pType = null;
}
}
private int ArraySize(TType pArrayType)
{
if (pArrayType.array.pElmtType.size == 0)
{
pArrayType.array.pElmtType.size =
ArraySize(pArrayType.array.pElmtType);
}
return (pArrayType.array.elmtCount *
pArrayType.array.pElmtType.size);
}
//TType Base
//{
// get { return Form == TFormCode.fcSubrange ? SubRange.BaseType : this; }
//}
internal static bool CheckAssignmentTypeCompatible(TType pTargetType, TType pValueType)
{
pTargetType = pTargetType.Base;
pValueType = pValueType.Base;
//--Two identical types.
if (pTargetType == pValueType) return true;
//--real := integer
if ((pTargetType == pRealType)
&& (pValueType == pIntegerType)) return true;
//--Two strings of the same length.
if ((pTargetType.Form == TFormCode.fcArray)
&& (pValueType.Form == TFormCode.fcArray)
&& (pTargetType.array.pElmtType == TType.pCharType)
&& (pValueType.array.pElmtType == TType.pCharType)
&& (pTargetType.array.elmtCount ==
pValueType.array.elmtCount))
{
return true;
}
return false;
}
internal static bool CheckIntegerOrReal(TType operandType1, TType operandType2 = null)
{
operandType2 = operandType2.Base;
if ((operandType2 != pIntegerType) && (operandType2 != pRealType))
{
return false;
}
if (operandType2 != null)
{
operandType2 = operandType2.Base;
if ((operandType2 != pIntegerType) && (operandType2 != pRealType))
{
return false;
}
}
return true;
}
public static TType SetType(ref TType pTargetType, TType pSourceType)
{
++pSourceType.refCount;
pTargetType = pSourceType;
return pSourceType;
}
public static bool RealOperands(TType firstOperandType, TType secondOperandType)
{
firstOperandType = firstOperandType.Base;
secondOperandType = secondOperandType.Base;
return ((firstOperandType == pRealType) && (secondOperandType == pRealType))
|| ((firstOperandType == pRealType) && (secondOperandType == pIntegerType))
|| ((secondOperandType == pRealType) && (firstOperandType == pIntegerType));
}
public static bool IntegerOperands(TType firstOperandType, TType secondOperandType)
{
firstOperandType = firstOperandType.Base;
secondOperandType = secondOperandType.Base;
return (firstOperandType == pIntegerType) && (secondOperandType == pIntegerType);
}
private TType ParseSubscripts(TType pType)
{
//--Loop to parse a list of subscripts separated by commas.
do
{
//-- [ (first) or , (subsequent)
GetTokenAppend();
//-- The current variable is an array type.
if (pType.Form == TFormCode.fcArray)
{
//--The subscript expression must be assignment type
//--compatible with the corresponding subscript type.
if (!TType.CheckAssignmentTypeCompatible(pType.array.pIndexType,
ParseExpression()))
{
OnError(TErrorCode.IncompatibleTypes);
}
//--Update the variable's type.
pType = pType.array.pElmtType;
}
//--No longer an array type, so too many subscripts.
//--Parse the extra subscripts anyway for error recovery.
else
{
OnError(TErrorCode.TooManySubscripts);
ParseExpression();
}
} while (token == TTokenCode.Comma);
//-- ]
CondGetTokenAppend(TTokenCode.RBracket, TErrorCode.MissingRightBracket);
return pType;
}
private TType ParseEnumerationType()
{
TType pType = new TType(TFormCode.fcEnum, sizeof(int), null);
SymtabNode pLastId = null;
int constValue = -1;
GetToken();
Resync(tlEnumConstStart);
while (token == TTokenCode.Identifier)
{
SymtabNode pConstId = EnterNewLocal(pToken.TokenString);
++constValue;
if (pConstId.defn.how == TDefnCode.dcUndefined)
{
pConstId.defn.how = TDefnCode.dcConstant;
pConstId.defn.constantValue.integerValue = constValue;
TType.SetType(ref pConstId.pType, pType);
if (pLastId == null)
{
pType.Enumeration.ConstIds = pLastId = pConstId;
}
else
{
pLastId.Next = pConstId;
pLastId = pConstId;
}
}
GetToken();
Resync(tlEnumConstFollow);
if (token == TTokenCode.Comma)
{
do
{
GetToken();
Resync(tlEnumConstStart, tlEnumConstFollow);
if (token == TTokenCode.Comma) OnError(TErrorCode.MissingIdentifier);
} while (token == TTokenCode.Comma);
if (token != TTokenCode.Identifier) OnError(TErrorCode.MissingComma);
}
else if (token == TTokenCode.Identifier) OnError(TErrorCode.MissingComma);
}
CondGetToken(TTokenCode.RParen, TErrorCode.MissingRightParen);
pType.Enumeration.max = constValue;
return pType;
}
private void ParseVarOrFieldDecls(SymtabNode pRoutineId,
TType pRecordType,
int offset)
{
SymtabNode pId, pFirstId, pLastId; // ptrs to symtab nodes
SymtabNode pPrevSublistLastId = null; // ptr to last node of
// previous sublist
int totalSize = 0; // local variables
// -- Loop to parse a list of variable or field declarations
// -- separated by semicolons.
while (token == TTokenCode.Identifier)
{
// -- <id-sublist>
pFirstId = ParseIdSublist(pRoutineId, pRecordType, out pLastId);
// -- :
Resync(tlSublistFollow, tlDeclarationFollow);
CondGetToken(TTokenCode.Colon, TErrorCode.MissingColon);
// -- <type>
TType pType = ParseTypeSpec();
// -- Now loop to assign the type and offset to each
// -- identifier in the sublist
for (pId = pFirstId; pId != null; pId = pId.Next)
{
TType.SetType(ref pId.pType, pType);
if (pRoutineId != null)
{
// -- Variables
pId.defn.dataOffset = offset++;
totalSize += pType.size;
}
else
{
// -- Record fields
pId.defn.dataOffset = offset;
offset += pType.size;
}
}
if (pFirstId != null)
{
// -- Set the first sublist into the routine id's symtab node.
if (pRoutineId != null &&
(pRoutineId.defn.routine.locals.pVariableIds == null))
{
pRoutineId.defn.routine.locals.pVariableIds = pFirstId;
}
// -- Link this list to the previous sublist
if (pPrevSublistLastId != null) pPrevSublistLastId.Next = pFirstId;
pPrevSublistLastId = pLastId;
}
// -- ; for variable and record field declaraion, or
// -- END for field declaration
if (pRoutineId != null)
{
Resync(tlDeclarationFollow, tlDeclarationStart);
CondGetToken(TTokenCode.Semicolon, TErrorCode.MissingSemicolon);
// -- Skip extra semicolons
while (token == TTokenCode.Semicolon) GetToken();
Resync(tlDeclarationFollow, tlDeclarationStart,
tlStatementStart);
}
else
{
Resync(tlFieldDeclFollow);
if (token != TTokenCode.End)
{
CondGetToken(TTokenCode.Semicolon, TErrorCode.MissingSemicolon);
// -- Skip extra semicolons
while (token == TTokenCode.Semicolon) GetToken();
Resync(tlFieldDeclFollow, tlDeclarationStart, tlStatementStart);
}
}
}
// -- Set the routine identifier node or the record type object.
if (pRoutineId != null)
{
pRoutineId.defn.routine.totalLocalSize = totalSize;
}
else
{
pRecordType.size = offset;
}
}
private TType ParseField(TType pType)
{
GetTokenAppend();
if ((token == TTokenCode.Identifier) && (pType.Form == TFormCode.fcRecord))
{
SymtabNode pFieldId = pType.record.pSymtab.Search(pToken.TokenString);
if (pFieldId == null) OnError(TErrorCode.InvalidField);
icode.Put(pFieldId);
GetTokenAppend();
return pFieldId != null ? pFieldId.pType : TType.pDummyType;
}
else
{
OnError(TErrorCode.InvalidField);
GetTokenAppend();
return TType.pDummyType;
}
}
private TType ParseArrayType()
{
TType pArrayType = new TType(TFormCode.fcArray, 0, null);
TType pElmtType = pArrayType;
bool indexFlag;
GetToken();
CondGetToken(TTokenCode.LBracket, TErrorCode.MissingLeftBracket);
do
{
ParseIndexType(pElmtType);
Resync(tlIndexFollow, tlIndexStart);
if (token == TTokenCode.Comma || TokenIn(token, tlIndexStart))
{
pElmtType = TType.SetType(ref pElmtType.array.pElmtType, new TType(TFormCode.fcArray, 0, null));
CondGetToken(TTokenCode.Comma, TErrorCode.MissingComma);
indexFlag = true;
}
else indexFlag = false;
} while (indexFlag);
CondGetToken(TTokenCode.RBracket, TErrorCode.MissingRightBracket);
Resync(tlIndexListFolow, tlDeclarationStart, tlStatementStart);
CondGetToken(TTokenCode.Of, TErrorCode.MissingOF);
TType.SetType(ref pElmtType.array.pElmtType, ParseTypeSpec());
if (pArrayType.Form != TFormCode.fcNone)
{
pArrayType.size = ArraySize(pArrayType);
}
return pArrayType;
}
public static bool CheckBoolean(TType firstOperandType, TType secondOperandType)
{
if ((firstOperandType.Base != pBooleanType)
|| (secondOperandType != null && (secondOperandType.Base != pBooleanType)))
{
return false;
}
else
{
return true;
}
}