private string InterpretFactor(TreeNode node)
{
var temp = SymbolTable.GetTempSymbol().Name;
switch (node.LeftNode.DataType)
{
case TokenType.PlusPlus:
Codes.AddLast(isVar
? new Quadruple(InstructionType.Plus, InterpretExp(node.MiddleNode), "1",
InterpretExp(node.MiddleNode), Line)
: new Quadruple(InstructionType.Plus, InterpretExp(node.MiddleNode), "1", temp, Line));
break;
case TokenType.MinusMinus:
Codes.AddLast(isVar
? new Quadruple(InstructionType.Minus, InterpretExp(node.MiddleNode), "1",
InterpretExp(node.MiddleNode), Line)
: new Quadruple(InstructionType.Minus, InterpretExp(node.MiddleNode), "1", temp, Line));
break;
case TokenType.Not:
Codes.AddLast(new Quadruple(InstructionType.Not, InterpretExp(node.MiddleNode), null, temp, Line));
break;
case TokenType.Plus:
Codes.AddLast(new Quadruple(InstructionType.Plus, "0", InterpretExp(node.MiddleNode), temp, Line));
break;
case TokenType.Minus:
Codes.AddLast(new Quadruple(InstructionType.Minus, "0", InterpretExp(node.MiddleNode), temp, Line));
break;
default:
if (node.MiddleNode.DataType == TokenType.PlusPlus)
{
var targetNode = node.LeftNode;
Codes.AddLast(new Quadruple(InstructionType.Assign, InterpretExp(targetNode), null, temp, Line));
Line++;
if (isVar)
{
Codes.AddLast(new Quadruple(InstructionType.Plus, InterpretExp(targetNode), "1", InterpretExp(targetNode), Line));
}
break;
}
else if (node.MiddleNode.DataType == TokenType.MinusMinus)
{
var targetNode = node.LeftNode;
Codes.AddLast(new Quadruple(InstructionType.Assign, InterpretExp(targetNode), null, temp, Line));
Line++;
if (isVar)
{
Codes.AddLast(new Quadruple(InstructionType.Minus, InterpretExp(targetNode), "1", InterpretExp(targetNode), Line));
}
break;
}
throw new InterpretException("ERROR : 因式表达式非法.\n");
}
Line++;
return(temp);
}
private void InterpretPrintStmt(TreeNode node)
{
var instruction = new Quadruple(InstructionType.Print, null, null, InterpretExp(node.LeftNode), Line);
Codes.AddLast(instruction);
Line++;
}
private void InterpretScanStmt(TreeNode node)
{
var targetNode = node.LeftNode.LeftNode;
var type = SymbolTable.FindSymbol(targetNode.Value).Type;
switch (type)
{
case SymbolType.IntValue:
case SymbolType.RealValue:
case SymbolType.CharValue:
Codes.AddLast(new Quadruple(InstructionType.Scan, null, null, targetNode.Value, Line));
Line++;
break;
case SymbolType.IntArray:
case SymbolType.RealArray:
case SymbolType.CharArray:
Codes.AddLast(new Quadruple(InstructionType.Scan, null, null, $"{targetNode.Value}{InterpretArrayDim(node.LeftNode.MiddleNode, out var dim)}", Line));
Line++;
break;
default:
throw new InterpretException("Error : 输入语句有误.\n");
}
}
private void InterpretELseStmt(TreeNode node, Quadruple jump, LinkedList <Quadruple> breakCode)
{
var elseJump = new Quadruple(InstructionType.Jump, null, null, null, Line);
Codes.AddLast(elseJump);
Line++;
jump.Third = (Line + 1).ToString();
if (node.LeftNode.Type != StmtType.StmtBlock)
{
Codes.AddLast(new Quadruple(InstructionType.In, null, null, null, Line));
Line++;
var table = new SymbolTable();
Level++;
InterpretStmt(node.LeftNode, breakCode);
Level--;
SymbolTable.DeRegister();
Codes.AddLast(new Quadruple(InstructionType.Out, null, null, null, Line));
Line++;
}
else
{
InterpretStmt(node.LeftNode, breakCode);
}
elseJump.Third = (Line + 1).ToString();
}
private string InterpretAssignExp(TreeNode node)
{
var str = InterpretExp(node.LeftNode);
if (!isVar)
{
throw new InterpretException("ERROR : 赋值表达式左值应该为变量.\n");
}
var temp = SymbolTable.GetTempSymbol().Name;
if (node.MiddleNode != null)
{
switch (node.MiddleNode.LeftNode.DataType)
{
case TokenType.Assign:
Codes.AddLast(new Quadruple(InstructionType.Assign, InterpretExp(node.MiddleNode.MiddleNode), null, str, Line));
break;
case TokenType.PlusAssign:
Codes.AddLast(new Quadruple(InstructionType.Plus, str, InterpretExp(node.MiddleNode.MiddleNode), temp, Line));
Line++;
Codes.AddLast(new Quadruple(InstructionType.Assign, temp, null, str, Line));
break;
case TokenType.MinusAssign:
Codes.AddLast(new Quadruple(InstructionType.Minus, str, InterpretExp(node.MiddleNode.MiddleNode), temp, Line));
Line++;
Codes.AddLast(new Quadruple(InstructionType.Assign, temp, null, str, Line));
break;
case TokenType.MulAssign:
Codes.AddLast(new Quadruple(InstructionType.Mul, str, InterpretExp(node.MiddleNode.MiddleNode), temp, Line));
Line++;
Codes.AddLast(new Quadruple(InstructionType.Assign, temp, null, str, Line));
break;
case TokenType.DivAssign:
Codes.AddLast(new Quadruple(InstructionType.Div, str, InterpretExp(node.MiddleNode.MiddleNode), temp, Line));
Line++;
Codes.AddLast(new Quadruple(InstructionType.Assign, temp, null, str, Line));
break;
case TokenType.ModAssign:
Codes.AddLast(new Quadruple(InstructionType.Mod, str, InterpretExp(node.MiddleNode.MiddleNode), temp, Line));
Line++;
Codes.AddLast(new Quadruple(InstructionType.Assign, temp, null, str, Line));
break;
default:
throw new InterpretException("ERROR : 赋值表达式非法.\n");
}
Line++;
}
return(str);
}
private string InterpretTerm(TreeNode node)
{
var temp = SymbolTable.GetTempSymbol().Name;
if (node.MiddleNode != null)
{
switch (node.MiddleNode.LeftNode.DataType)
{
case TokenType.Mul:
Codes.AddLast(new Quadruple(InstructionType.Mul, InterpretExp(node.LeftNode), InterpretExp(node.MiddleNode.MiddleNode), temp, Line));
break;
case TokenType.Div:
Codes.AddLast(new Quadruple(InstructionType.Div, InterpretExp(node.LeftNode), InterpretExp(node.MiddleNode.MiddleNode), temp, Line));
break;
case TokenType.Mod:
Codes.AddLast(new Quadruple(InstructionType.Mod, InterpretExp(node.LeftNode), InterpretExp(node.MiddleNode.MiddleNode), temp, Line));
break;
default:
throw new InterpretException("ERROR : 算术运算非法.\n");
}
Line++;
node = node.MiddleNode;
}
while (node.RightNode != null)
{
var tempN = temp;
temp = SymbolTable.GetTempSymbol().Name;
switch (node.RightNode.LeftNode.DataType)
{
case TokenType.Mul:
Codes.AddLast(new Quadruple(InstructionType.Mul, tempN, InterpretExp(node.RightNode.MiddleNode), temp, Line));
break;
case TokenType.Div:
Codes.AddLast(new Quadruple(InstructionType.Div, tempN, InterpretExp(node.RightNode.MiddleNode), temp, Line));
break;
case TokenType.Mod:
Codes.AddLast(new Quadruple(InstructionType.Mod, tempN, InterpretExp(node.RightNode.MiddleNode), temp, Line));
break;
default:
throw new InterpretException("ERROR : 算术运算非法.\n");
}
Line++;
node = node.RightNode;
}
return(temp);
}
private string InterpretExp(TreeNode node)
{
isVar = false;
if (node.Type == StmtType.Exp)
{
switch (node.DataType)
{
case TokenType.AdditiveExp:
return(InterpretAdditiveExp(node));
case TokenType.AssignExp:
return(InterpretAssignExp(node));
case TokenType.LogicOrExp:
return(InterpretLogicOrExp(node));
case TokenType.LogicAndExp:
return(InterpretLogicAndExp(node));
case TokenType.CompExp:
return(InterpretCompExp(node));
case TokenType.CompEqExp:
return(InterpretCompEqExp(node));
default:
throw new InterpretException("ERROR : 复合表达式非法.\n");
}
}
if (node.Type == StmtType.Term)
{
return(InterpretTerm(node));
}
if (node.Type == StmtType.Factor)
{
return(InterpretFactor(node));
}
if (node.Type == StmtType.Var)
{
isVar = true;
return(InterpretVariable(node));
}
if (node.Type == StmtType.Value || node.Type == StmtType.Null)
{
var temp = SymbolTable.GetTempSymbol().Name;
Codes.AddLast(new Quadruple(InstructionType.Assign, $"{node.Value}", null, temp, Line));
Line++;
return(temp);
}
throw new InterpretException("ERROR : 表达式非法.\n");
}
private void InterpretWhileStmt(TreeNode node)
{
isRepeat = true;
var jumpLine = Line + 1;
var instruction = new Quadruple(InstructionType.Jump, InterpretExp(node.LeftNode), null, null, Line);
Codes.AddLast(instruction);
Line++;
inPos.AddLast(Line);
var breakCode = new LinkedList <Quadruple>();
if (node.MiddleNode != null)
{
if (node.MiddleNode.Type != StmtType.StmtBlock)
{
Codes.AddLast(new Quadruple(InstructionType.In, null, null, null, Line));
Line++;
var table = new SymbolTable();
Level++;
InterpretStmt(node.MiddleNode, breakCode);
Level--;
SymbolTable.DeRegister();
Codes.AddLast(new Quadruple(InstructionType.Out, null, null, null, Line));
Line++;
}
else
{
InterpretStmt(node.MiddleNode, breakCode);
}
}
Codes.AddLast(new Quadruple(InstructionType.Jump, null, null, jumpLine.ToString(), Line));
Line++;
outPos.AddLast(Line + 1);
if (breakCode != null)
{
foreach (var c in breakCode)
{
c.Third = (Line + 1).ToString();
}
}
instruction.Third = (Line + 1).ToString();
outPos.RemoveLast();
inPos.RemoveLast();
if (Level == 0)
{
isRepeat = false;
}
}
private void InterpretStmtBlock(TreeNode node, LinkedList <Quadruple> breakCode)
{
Codes.AddLast(new Quadruple(InstructionType.In, null, null, null, Line));
Line++;
Level++;
var table = new SymbolTable();
if (node.LeftNode != null)
{
InterpretStmtSeq(node.LeftNode, breakCode);
}
SymbolTable.DeRegister();
Level--;
Codes.AddLast(new Quadruple(InstructionType.Out, null, null, null, Line));
Line++;
}
private void InterpretIfStmt(TreeNode node, LinkedList <Quadruple> breakCode)
{
var jump = new Quadruple(InstructionType.Jump, InterpretExp(node.LeftNode), null, null, Line);
Codes.AddLast(jump);
Line++;
if (node.MiddleNode != null)
{
if (node.MiddleNode.Type == StmtType.ElseStmt)
{
Codes.AddLast(new Quadruple(InstructionType.In, null, null, null, Line));
Line++;
Codes.AddLast(new Quadruple(InstructionType.Out, null, null, null, Line));
Line++;
InterpretELseStmt(node, jump, breakCode);
}
else
{
if (node.MiddleNode.LeftNode.Type != StmtType.StmtBlock)
{
Codes.AddLast(new Quadruple(InstructionType.In, null, null, null, Line));
Line++;
var table = new SymbolTable();
Level++;
InterpretStmt(node.MiddleNode.LeftNode, breakCode);
Level--;
SymbolTable.DeRegister();
Codes.AddLast(new Quadruple(InstructionType.Out, null, null, null, Line));
Line++;
}
else
{
InterpretStmt(node.MiddleNode.LeftNode, breakCode);
}
jump.Third = (Line + 1).ToString();
if (node.MiddleNode.MiddleNode != null)
{
InterpretELseStmt(node.MiddleNode.MiddleNode, jump, breakCode);
}
}
}
else
{
jump.Third = (Line + 1).ToString();
}
}
private void InterpretJumpStmt(TreeNode node, out Quadruple jump)
{
if (!isRepeat)
{
throw new InterpretException("ERROR : 跳转语句需要在循环体内.\n");
}
jump = new Quadruple(InstructionType.Jump, null, null, null, Line);
if (node.DataType == TokenType.Break)
{
jump.Second = "break";
jump.Third = outPos.Last.Value.ToString();
}
else if (node.DataType == TokenType.Continue)
{
jump.Second = "continue";
jump.Third = inPos.Last.Value.ToString();
}
Codes.AddLast(jump);
Line++;
}
private string InterpretLogicAndExp(TreeNode node)
{
var temp = SymbolTable.GetTempSymbol().Name;
if (node.MiddleNode != null)
{
if (node.MiddleNode.LeftNode.DataType == TokenType.And)
{
Codes.AddLast(new Quadruple(InstructionType.And, InterpretExp(node.LeftNode),
InterpretExp(node.MiddleNode.MiddleNode), temp, Line));
}
else
{
throw new InterpretException("ERROR : 逻辑运算非法.\n");
}
Line++;
node = node.MiddleNode;
}
while (node.RightNode != null)
{
var tempN = temp;
temp = SymbolTable.GetTempSymbol().Name;
if (node.RightNode.LeftNode.DataType == TokenType.And)
{
Codes.AddLast(new Quadruple(InstructionType.And, tempN, InterpretExp(node.RightNode.MiddleNode),
temp, Line));
}
else
{
throw new InterpretException("ERROR : 逻辑运算非法.\n");
}
Line++;
node = node.RightNode;
}
return(temp);
}
private void InterpretDecVariable(TreeNode node, int type, SymbolList table)
{
var variable = node;
if (variable.MiddleNode == null)
{
string value = null;
if (variable.RightNode != null)
{
value = InterpretExp(variable.RightNode.MiddleNode);
}
if (type == TokenType.Int)
{
Codes.AddLast(new Quadruple(InstructionType.Int, value, null, variable.LeftNode.Value, Line));
Line++;
var symbol = new Symbol(variable.LeftNode.Value, SymbolType.IntValue, Level);
SymbolTable.Register(symbol);
}
else if (type == TokenType.Real)
{
Codes.AddLast(new Quadruple(InstructionType.Real, value, null, variable.LeftNode.Value, Line));
Line++;
var symbol = new Symbol(variable.LeftNode.Value, SymbolType.RealValue, Level);
SymbolTable.Register(symbol);
}
else if (type == TokenType.Char)
{
Codes.AddLast(new Quadruple(InstructionType.Char, value, null, variable.LeftNode.Value, Line));
Line++;
var symbol = new Symbol(variable.LeftNode.Value, SymbolType.CharValue, Level);
SymbolTable.Register(symbol);
}
}
else if (variable.MiddleNode != null) //数组暂时不能初始化
{
if (variable.RightNode != null)
{
throw new InterpretException("ERROR : 初始化非法.\n");
}
var len = InterpretArrayDim(variable.MiddleNode, out var dim);
if (type == TokenType.Int)
{
Codes.AddLast(new Quadruple(InstructionType.Int, dim.ToString(), len, variable.LeftNode.Value, Line));
Line++;
var symbol = new Symbol(variable.LeftNode.Value, SymbolType.IntArray, Level);
SymbolTable.Register(symbol);
}
else if (type == TokenType.Real)
{
Codes.AddLast(new Quadruple(InstructionType.Real, dim.ToString(), len, variable.LeftNode.Value, Line));
Line++;
var symbol = new Symbol(variable.LeftNode.Value, SymbolType.RealArray, Level);
SymbolTable.Register(symbol);
}
else if (type == TokenType.Char)
{
Codes.AddLast(new Quadruple(InstructionType.Char, dim.ToString(), len, variable.LeftNode.Value, Line));
Line++;
var symbol = new Symbol(variable.LeftNode.Value, SymbolType.CharArray, Level);
SymbolTable.Register(symbol);
}
}
}