/**
* Function representing the <st_prime> productions
*/
void RecursiveDescentParser::st_prime(Type type) {
if(errorCondition) return;
if(token == TK_COMMA)
{
token = scanner->getToken();
#if DEBUG_PARSER
std::cout << "<st_prime> --> ,i<arr_spec><st_prime>\n";
#endif
if(token!=TK_IDENTIFIER){
// error
}
if(symTab.search(token)) {
std::stringstream msg;
msg << "Duplicate variable declaration '" << token.getValue() << "'";
errorHandler(msg.str(), token);
}
VariableEntry* entry = new VariableEntry();
entry->setType(type);
symTab.insert(token, entry);
token = scanner->getToken();
VariableAttribute va = arr_spec();
entry->setAttribute(va);
st_prime(type);
}
else if(token == TK_SEMICOLON)
{
#if DEBUG_PARSER
std::cout << "<st_prime> --> e\n";
#endif
}
else
{
errorHandler();
}
}
/**
* Functions representing the <st> productions
*/
void RecursiveDescentParser::st() {
if(token == TK_SEMICOLON)
{
#if DEBUG_PARSER
std::cout << "<st> --> ;\n";
#endif
token = scanner->getToken();
}
else if(token == TK_LEFT_BRACE)
{
#if DEBUG_PARSER
std::cout << "<st> --> <comp_st>\n";
#endif
comp_st();
}
else if(token == TK_IF)
{
#if DEBUG_PARSER
std::cout << "<st> --> if<log_exp><st>else<st>\n";
#endif
token = scanner->getToken();
attr logExp = log_exp();
std::string lbl1 = iCode.getNextLabel();
iCode.threeAddressCode(TAC_IF_FALSE, logExp, lbl1);
st();
std::string lbl2 = iCode.getNextLabel();
iCode.threeAddressCode(TAC_GOTO, lbl2);
match(TK_ELSE);
iCode.threeAddressCode(lbl1);
st();
iCode.threeAddressCode(lbl2);
}
else if(token == TK_WHILE)
{
#if DEBUG_PARSER
std::cout << "<st> --> while<log_exp><st>\n";
#endif
token = scanner->getToken();
std::string lbl1 = iCode.getNextLabel();
iCode.threeAddressCode(lbl1);
std::string lbl2 = iCode.getNextLabel();
attr cond = log_exp();
iCode.threeAddressCode(TAC_IF_FALSE, cond, lbl2);
st();
iCode.threeAddressCode(TAC_GOTO, lbl1);
iCode.threeAddressCode(lbl2);
}
else if(token == TK_RETURN)
{
#if DEBUG_PARSER
std::cout << "<st> --> return(<exp>);\n";
#endif
Token sToken = token;
token = scanner->getToken();
match(TK_LEFT_PARENTHESES);
attr expAttr = exp();
const FunctionEntry* fe = symTab.getCurrentFunction();
if(expAttr.type != fe->getReturnType() && fe->getReturnType() != T_VOID) {
std::stringstream ss;
ss << "Type Mismatch, function '" << fe->getName() << "' must return ";
if(fe->getReturnType() == T_INT) ss << "an integer";
if(fe->getReturnType() == T_CHAR) ss << "a character";
errorHandler(ss.str(), sToken);
}
match(TK_RIGHT_PARENTHESES);
match(TK_SEMICOLON);
iCode.threeAddressCode(TAC_SAVE_RET_VAL, expAttr);
iCode.threeAddressCode(TAC_GOTO, currentReturnLabel);
}
else if(token == TK_SCANF)
{
#if DEBUG_PARSER
std::cout << "<st> --> scanf<i_list>;\n";
#endif
token = scanner->getToken();
ParamList* pList = i_list();
match(TK_SEMICOLON);
iCode.threeAddressCode(TAC_READ, pList);
}
else if(token == TK_PRINTF)
{
#if DEBUG_PARSER
std::cout << "<st> --> printf<o_list>;\n";
#endif
token = scanner->getToken();
ParamList* pList = o_list();
match(TK_SEMICOLON);
iCode.threeAddressCode(TAC_WRITE, pList);
}
else if(token == TK_IDENTIFIER)
{
#if DEBUG_PARSER
std::cout << "<st> --> i<st_factor_ident>\n";
#endif
TableEntry* te=NULL;
if(!symTab.search(token, te)) {
errorHandler("Undefined identifier", token);
}
token = scanner->getToken();
st_factor_ident(te);
}
else if(token == TK_INT)
{
#if DEBUG_PARSER
std::cout << "<st> --> int i <st_factor_type>\n";
#endif
token = scanner->getToken();
if(token!=TK_IDENTIFIER) {
errorHandler();
}
if(symTab.search(token) ) {
std::stringstream msg;
msg << "Duplicate variable declaration '" << token.getValue() << "'";
errorHandler(msg.str(), token);
}
VariableEntry* vEntry = new VariableEntry();
vEntry->setType(T_INT);
vEntry->setName( token.getValue() );
//std::string varName = token.getValue();
token = scanner->getToken();
st_factor_type(vEntry);
//symTab.insert(varName, vEntry);
}
else if(token == TK_CHAR)
{
#if DEBUG_PARSER
std::cout << "<st> --> char i <st_factor_type>\n";
#endif
token = scanner->getToken();
if(token!=TK_IDENTIFIER) {
errorHandler();
}
if(symTab.search(token)) {
// aready declared in this scope
std::stringstream msg;
msg << "Duplicate variable declaration '" << token.getValue() << "'";
errorHandler(msg.str(), token);
}
VariableEntry* vEntry = new VariableEntry();
vEntry->setType(T_CHAR);
vEntry->setName( token.getValue() );
//std::string varName = token.getValue();
token = scanner->getToken();
st_factor_type(vEntry);
//symTab.insert(varName, vEntry);
}
else
{
errorHandler();
}
if(errorCondition) {
while(token!=TK_EOF) {
token = scanner->getToken();
if(token==TK_RIGHT_BRACE) {
errorCondition=false;
break;
}
if(token==TK_SEMICOLON) {
errorCondition=false;
token = scanner->getToken();
break;
}
}
}
}