internal static TableAddStatus AddFun(FunSymbol funItem)
{
if (FindFun(funItem.name) != null)
{
return(TableAddStatus.SYMBOL_EXIST);
}
funs.Add(funItem.name, funItem);
return(TableAddStatus.SUCCEED);
}
private void Paras(FunSymbol fun)
{
if (Utils.IsTypeTag(next.Tag))
{
Para(fun);
if (TagIs(Tag.DL_COM))
{
Move();
Paras(fun);
}
}
}
private void Para(FunSymbol fun)
{
VarSymbol para = new VarSymbol();
para.type = Utils.TagToType(next.Tag);
Move();
string id = TagIs(Tag.ID) ? next.Value : null;
if (id != null)
{
Move();
}
if (para.type != VarType.TYPE_VOID)
{
para.scopeId = ScopeManager.CurrentScope;
para.offsetInFun = -(2 + fun.parasType.Count) * 8;
if (TagIs(Tag.DL_LSQU))
{
para.eleType = para.type;
para.eleSize = Utils.SizeOf(para.eleType);
para.type = VarType.TYPE_PTR;
Move();
RequiredToken(Tag.DL_RSQU);
}
}
if (id != null)
{
para.name = id;
if (SymbolTable.AddVar(para) == TableAddStatus.SYMBOL_EXIST)
{
new ConflictingDeclarationError().PrintErrMsg();
}
}
fun.parasType.Add(para.type);
}
private void Function(FunctionNode node)
{
FunSymbol fun = new FunSymbol();
fun.returnType = Utils.TagToType(next.Tag);
Move();
string id = RequiredToken(Tag.ID);
if (id != null)
{
fun.name = id;
node.name = id;
ScopeManager.FunctionEnter(id);
}
ScopeManager.ScopeEnter();
RequiredToken(Tag.DL_LPAR);
Paras(fun);
if (fun.parasType.Count > 1 && fun.parasType.Contains(VarType.TYPE_VOID))
{
new Error().PrintErrMsg();
}
else if (fun.parasType.Contains(VarType.TYPE_VOID))
{
fun.parasType = new List <VarType>();
}
RequiredToken(Tag.DL_RPAR);
// 查看符号表中是否有同名函数
FunSymbol tmp = SymbolTable.FindFun(fun.name);
bool sameFunExist = false;
if (tmp != null)
{
// 若存在同名函数则检查函数签名
if (tmp.parasType.Count == fun.parasType.Count)
{
int i = 0;
for (i = 0; i < tmp.parasType.Count; i++)
{
if (tmp.parasType[i] != fun.parasType[i])
{
break;
}
}
sameFunExist = i == tmp.parasType.Count && tmp.returnType == fun.returnType;
}
}
if (TagIs(Tag.DL_LBRACE))
{
// 函数定义
fun.isExtern = false;
if (sameFunExist)
{
if (tmp.isExtern)
{
tmp.isExtern = false; // 存在函数定义，符号表中已有的函数不再是extern
}
else
{
new Error().PrintErrMsg(); // 存在重复定义
}
}
}
else if (TagIs(Tag.DL_SEM))
{
// 函数声明
fun.isExtern = true;
}
if (!sameFunExist)
{
if (SymbolTable.AddFun(fun) == TableAddStatus.SYMBOL_EXIST)
{
// 不同签名的函数名冲突
new Error().PrintErrMsg();
}
}
if (TagIs(Tag.DL_SEM))
{
Move();
}
else
{
node.body = new BlockNode();
Block(node.body);
}
ScopeManager.ScopeLeave();
ScopeManager.FunctionLeave();
}
private void Decl(DeclNode node)
{
FunSymbol function = SymbolTable.FindFun(ScopeManager.CurrentFun);
VarSymbol variable = new VarSymbol();
if (TagIs(Tag.KW_CONST))
{
variable.isConst = true;
Move();
}
node.type = Utils.TagToType(next.Tag);
Move();
if (node.type == VarType.TYPE_VOID)
{
new Error().PrintErrMsg();
}
node.name = RequiredToken(Tag.ID);
if (TagIs(Tag.DL_SET))
{
Move();
node.init = new ExprNode();
Expr(node.init);
if (node.init.Type() != node.type)
{
if (!Utils.IsNumType(node.init.Type()) || !Utils.IsNumType(node.type))
{
new TypeMismatchError(node.type, node.init.Type()).PrintErrMsg();
}
}
}
else if (TagIs(Tag.DL_LSQU))
{
Move();
variable.eleSize = Utils.SizeOf(node.type);
variable.eleType = node.type;
variable.isConst = true;
node.type = VarType.TYPE_PTR;
node.size = new ExprNode();
Expr(node.size);
if (!Utils.IsNumType(node.size.Type()) || !node.size.IsConstant())
{
new Error().PrintErrMsg();
}
else
{
function.localVarSize += (int)(node.size.Val() as IntNode).value * variable.eleSize;
}
RequiredToken(Tag.DL_RSQU);
}
if (node.name != null)
{
function.localVarSize += Utils.SizeOf(node.type);
variable.name = node.name;
variable.type = node.type;
variable.scopeId = ScopeManager.CurrentScope;
variable.offsetInFun = function.localVarSize;
if (SymbolTable.AddVar(variable) == TableAddStatus.SYMBOL_EXIST)
{
new ConflictingDeclarationError().PrintErrMsg();
}
}
RequiredToken(Tag.DL_SEM);
}