const CType* CAstBinaryOp::GetType(void) const
{
CTypeManager *tm = CTypeManager::Get();
EOperation oper = GetOperation();
// If lhs or rhs is null, then null.
if(_left->GetType() == NULL || _right->GetType() == NULL)
return NULL;
// case '+', '-', '*', '/'
if(oper == opAdd || oper == opSub || oper == opMul || oper == opDiv) {
if(_left->GetType()->IsInt() && _right->GetType()->IsInt())
return tm->GetInt();
else return NULL;
}
// case '&&' , '||'
else if(oper == opAnd || oper == opOr) {
if(_left->GetType()->IsBoolean() && _right->GetType()->IsBoolean())
return tm->GetBool();
else return NULL;
}
// case '=', '#'
else if(oper == opEqual || oper == opNotEqual) {
if(_left->GetType()->IsBoolean() && _right->GetType()->IsBoolean() ||
_left->GetType()->IsChar() && _right->GetType()->IsChar() ||
_left->GetType()->IsInt() && _right->GetType()->IsInt())
return tm->GetBool();
else return NULL;
}
// case '>', '>=', '<', '<='
else {
if(_left->GetType()->IsInt() && _right->GetType()->IsInt() ||
_left->GetType()->IsChar() && _right->GetType()->IsChar())
return tm->GetBool();
else return NULL;
}
}
const CType* CAstUnaryOp::GetType(void) const
{
CTypeManager *tm = CTypeManager::Get();
EOperation oper = GetOperation();
CAstExpression *e = GetOperand();
if(e->GetType() == NULL)
return NULL;
if(oper == opNeg || oper == opPos) { //case '+' || '-'
if(e->GetType()->IsInt())
return tm->GetInt();
else return NULL;
}
else { // case '!'
if(e->GetType()->IsBoolean())
return tm->GetBool();
else return NULL;
}
}
const CType* CParser::type(bool isParam, bool isFunction) {
//
// type ::= basetype | type "[" [ number ] "]".
// basetype ::= "boolean" | "char" | "integer".
//
CToken t;
CToken tk;
EToken tt = _scanner->Peek().GetType();
CTypeManager *tm = CTypeManager::Get();
const CType *type;
vector<int> nelems;
// basetype cases.
switch(tt) {
case tBoolean:
Consume(tBoolean, &t);
tk = t;
type = dynamic_cast<const CType *>(tm->GetBool());
break;
case tChar:
Consume(tChar, &t);
tk = t;
type = dynamic_cast<const CType *>(tm->GetChar());
break;
case tInteger:
Consume(tInteger, &t);
tk = t;
type = dynamic_cast<const CType *>(tm->GetInt());
break;
default:
SetError(_scanner->Peek(), "basetype expected.");
break;
}
assert(type != NULL);
// array case.
while(_scanner->Peek().GetType() == tLSBrak) {
Consume(tLSBrak);
CToken nelem;
if(_scanner->Peek().GetType() == tNumber) {
Consume(tNumber, &nelem);
nelems.push_back(atoi(nelem.GetValue().c_str()));
}
else {
// open arrays are allowed only in parameter.
if(isParam)
nelems.push_back(-1);
else
SetError(_scanner->Peek(), "expected 'tNumber', got '" + _scanner->Peek().GetName() + "'");
}
Consume(tRSBrak);
}
for(int i = nelems.size()-1; i >= 0; i--) {
type = dynamic_cast<const CType *>(tm->GetArray(nelems[i], type));
assert(type != NULL);
nelems.pop_back();
// Arrays are addressed in parameter.
if(i == 0 && isParam)
type = dynamic_cast<const CType *>(tm->GetPointer(type));
}
if(isFunction && !type->IsScalar()) {
SetError(tk, "invalid composite type for function.");
}
return type;
}
CAstExpression* CParser::factor(CAstScope *s) {
//
// factor ::= qualident | number | boolean | char | string | "(" expression ")" | subroutineCall | "!" factor.
// FIRST(factor) = { tIdent, tNumber, tTrue, tFalse, tCharacter, tString, tLBrak, tEMark }.
//
CToken t;
EToken tt = _scanner->Peek().GetType();
CTypeManager *tm = CTypeManager::Get();
CAstExpression *n = NULL;
CSymtab *symtab = s->GetSymbolTable();
switch(tt) {
case tTrue:
Consume(tTrue, &t);
n = new CAstConstant(t, tm->GetBool(), 1);
break;
case tFalse:
Consume(tFalse, &t);
n = new CAstConstant(t, tm->GetBool(), 0);
break;
case tNumber:
{
Consume(tNumber, &t);
errno = 0;
long long v = strtoll(t.GetValue().c_str(), NULL, 10);
if (errno != 0) SetError(t, "invalid number.");
// integer range validation check.
if(v > 2147483648)
SetError(t, "integer constant outside valid range.");
n = new CAstConstant(t, tm->GetInt(), v);
break;
}
case tIdent:
{
Consume(tIdent, &t);
if(_scanner->Peek().GetType() == tLBrak) { // subroutineCall
Consume(tLBrak);
CAstFunctionCall *f;
// If subroutineCall calls undefined procedure/function, then set error.
if(symtab->FindSymbol(t.GetValue(),sLocal) == NULL && symtab->FindSymbol(t.GetValue(), sGlobal) != NULL) {
// Check if symbol is procedure.
if(dynamic_cast<const CSymProc *>(symtab->FindSymbol(t.GetValue(), sGlobal)) == NULL)
SetError(t, "invalid procedure/function identifier.");
f = new CAstFunctionCall(t, dynamic_cast<const CSymProc *>(symtab->FindSymbol(t.GetValue(), sGlobal)));
}
else if(symtab->FindSymbol(t.GetValue(), sLocal) != NULL) {
// Check if symbol is procedure.
if(dynamic_cast<const CSymProc *>(symtab->FindSymbol(t.GetValue(), sLocal)) == NULL)
SetError(t, "invalid procedure/function identifier.");
f = new CAstFunctionCall(t, dynamic_cast<const CSymProc *>(symtab->FindSymbol(t.GetValue(), sLocal)));
}
else
SetError(t, "undefined identifier.");
assert(f != NULL);
if(isExpr(_scanner->Peek())) {
CAstExpression *expr = expression(s);
assert(expr != NULL);
// If array, then addressed.
if(expr->GetType()->IsArray())
expr = new CAstSpecialOp(expr->GetToken(), opAddress, expr, NULL);
f->AddArg(expr);
while(_scanner->Peek().GetType() == tComma) {
Consume(tComma);
expr = expression(s);
assert(expr != NULL);
// If array, then addressed.
if(expr->GetType()->IsArray())
expr = new CAstSpecialOp(expr->GetToken(), opAddress, expr, NULL);
f->AddArg(expr);
}
}
Consume(tRBrak);
n = f;
}
else { // qualident
if(_scanner->Peek().GetType() == tLSBrak) { // It means array
CAstArrayDesignator *f;
if(symtab->FindSymbol(t.GetValue(), sLocal) == NULL && symtab->FindSymbol(t.GetValue(), sGlobal) != NULL) {
// Check if symbol is procedure.
if(dynamic_cast<const CSymProc *>(symtab->FindSymbol(t.GetValue(), sGlobal)) != NULL)
SetError(t, "designator expected.");
f = new CAstArrayDesignator(t, symtab->FindSymbol(t.GetValue(), sGlobal));
}
else if(symtab->FindSymbol(t.GetValue(), sLocal) != NULL) {
// Check if symbol is procedure.
if(dynamic_cast<const CSymProc *>(symtab->FindSymbol(t.GetValue(), sLocal)) != NULL)
SetError(t, "designator expected");
f = new CAstArrayDesignator(t, symtab->FindSymbol(t.GetValue(), sLocal));
}
else {
SetError(t, "undefined identifier.");
}
while(_scanner->Peek().GetType() == tLSBrak) {
Consume(tLSBrak);
CAstExpression *expr = expression(s);
assert(expr != NULL);
f->AddIndex(expr);
Consume(tRSBrak);
}
f->IndicesComplete();
n = f;
} // non-array case.
else {
if(symtab->FindSymbol(t.GetValue(), sLocal) == NULL && symtab->FindSymbol(t.GetValue(), sGlobal) != NULL) {
// Check if symbol is procedure.
if(dynamic_cast<const CSymProc *>(symtab->FindSymbol(t.GetValue(), sGlobal)) != NULL) {
SetError(t, "designator expected.");
}
n = new CAstDesignator(t, symtab->FindSymbol(t.GetValue(), sGlobal));
}
else if(symtab->FindSymbol(t.GetValue(), sLocal) != NULL) {
// Check if symbol is procedure.
if(dynamic_cast<const CSymProc *>(symtab->FindSymbol(t.GetValue(), sLocal)) != NULL) {
SetError(t, "designator expected.");
}
n = new CAstDesignator(t, symtab->FindSymbol(t.GetValue(), sLocal));
}
else
SetError(t, "undefined identifier.");
}
}
break;
}
case tString:
Consume(tString, &t);
n = new CAstStringConstant(t, t.GetValue(), s);
break;
case tCharacter:
{
Consume(tCharacter, &t);
char res;
// If character length is 0, it means character is '\0' because invalid character cases are handled in scanner.
if(t.GetValue().length() == 0)
res = '\0';
else if(t.GetValue().length() == 1) {
if(t.GetValue().at(0) != '\\')
res = t.GetValue().at(0);
else SetError(t, "wrong character");
}
// unescape.
else if(t.GetValue().length() == 2) {
if(t.GetValue().at(0) == '\\') {
if(t.GetValue().at(1) == 'n') {
res = '\n';
}
else if(t.GetValue().at(1) == 't') {
res = '\t';
}
else if(t.GetValue().at(1) == '"') {
res = '"';
}
else if(t.GetValue().at(1) == '\'') {
res = '\'';
}
else if(t.GetValue().at(1) == '\\') {
res = '\\';
}
else if(t.GetValue().at(1) == '0') {
res = '\0';
}
else
SetError(t, "wrong character");
}
}
else SetError(t, "wrong character");
n = new CAstConstant(t, tm->GetChar(), (long long)res);
break;
}
case tLBrak:
Consume(tLBrak);
n = expression(s);
Consume(tRBrak);
break;
case tEMark:
Consume(tEMark, &t);
n = new CAstUnaryOp(t, opNot, factor(s));
break;
default:
// cout << "got " << _scanner->Peek() << endl;
SetError(_scanner->Peek(), "factor expected.");
break;
}
return n;
}