int parse(void **progTree, int uGrammar) {
SYMB_INFO *stack[200],
**spt = stack,
*curSymb,
mainSymb = {0, INIT_SYMB, 0, {}, NULL};
TOKEN curToken;
int ruleNo, i;
if(uGrammar >= 0)
mainSymb.type = uGrammar;
//insert main symbol in stack and read first token
*spt++ = &mainSymb;
if(getToken(&curToken) != PAR_OK)
return PAR_ERROR;
while(spt != stack) {
curSymb = *--spt;
if(curSymb->isTerminal) {
//termatiko symbolo
if(curSymb->type == curToken.type) {
//tairiazei me to symbolo sthn eisodo.
curSymb->value = curToken.value; //Apo8hkeysh timhs
if(getToken(&curToken) != PAR_OK) //pairnoyme neo symbolo
return PAR_ERROR;
} else
return PAR_ERROR;
} else {
//mh termatiko symbolo
ruleNo = LL1[curSymb->type - TRMNO][curToken.type]; //eyresh kanona
if(ruleNo == -1) return PAR_ERROR; //syntaktiko la8os
//pros8hkh olwn twn symbolwn toy de3iou merous tou kanona sth stoiba me
//anapodh seira. Kratame ta symbola ayta ston pinaka chl
curSymb->ruleNo = ruleNo;
for(i = grammar[ruleNo].rsNo - 1; i >= 0; i--) {
SYMB_INFO *tmpSymb = malloc(sizeof(SYMB_INFO));
curSymb->chl[i] = tmpSymb;
tmpSymb->type = grammar[ruleNo].rs[i];
tmpSymb->isTerminal = (tmpSymb->type < TRMNO);
tmpSymb->value = NULL;
*spt++ = tmpSymb;
}
}
}
//dhmioyrgia syntantikou dentrou
buildParseTree(&mainSymb);
//epityxia
if(progTree) *progTree = mainSymb.value;
return PAR_OK;
}
void buildParseTree(SYMB_INFO *symb) {
int i;
//ean to symbolo einai termatiko tote den xreiazetai epe3ergasia
if(symb->isTerminal)
return;
//prwta epe3ergazomaste ola ta paidia
for(i = 0; i < grammar[symb->ruleNo].rsNo; i++)
buildParseTree(symb->chl[i]);
//epe3ergasia toy kanona
grammar[symb->ruleNo].func(symb);
//apeley8erwsh mnhmhs
for(i = 0; i < grammar[symb->ruleNo].rsNo; i++) {
if(symb->chl[i]->isTerminal)
free(symb->chl[i]->value);
free(symb->chl[i]);
}
}
execplan::ParseTree* ScalarSub::transform()
{
if (!fFunc)
return NULL;
// @todo need to handle scalar IN and BETWEEN specially
// this blocks handles only one subselect scalar
// arg[0]: column | arg[1]: subselect
//idbassert(fGwip.rcWorkStack.size() >= 2);
if (fFunc->functype() == Item_func::BETWEEN)
return transform_between();
if (fFunc->functype() == Item_func::IN_FUNC)
return transform_in();
ReturnedColumn* rhs = NULL;
ReturnedColumn* lhs = NULL;
if (!fGwip.rcWorkStack.empty())
{
rhs = fGwip.rcWorkStack.top();
fGwip.rcWorkStack.pop();
}
if (!fGwip.rcWorkStack.empty())
{
lhs = fGwip.rcWorkStack.top();
fGwip.rcWorkStack.pop();
}
PredicateOperator* op = new PredicateOperator(fFunc->func_name());
if (!lhs && (fFunc->functype() == Item_func::ISNULL_FUNC ||
fFunc->functype() == Item_func::ISNOTNULL_FUNC))
{
fSub = (Item_subselect*)(fFunc->arguments()[0]);
fColumn.reset(new ConstantColumn("", ConstantColumn::NULLDATA));
delete rhs;
return buildParseTree(op);
}
bool reverseOp = false;
SubSelect* sub = dynamic_cast<SubSelect*>(rhs);
if (!sub)
{
reverseOp = true;
delete lhs;
lhs = rhs;
fSub = (Item_subselect*)(fFunc->arguments()[0]);
}
else
{
delete rhs;
fSub = (Item_subselect*)(fFunc->arguments()[1]);
}
fColumn.reset(lhs); // column should be in the stack already. in, between may be different
//PredicateOperator *op = new PredicateOperator(fFunc->func_name());
if (reverseOp)
op->reverseOp();
return buildParseTree(op);
}
execplan::ParseTree* ScalarSub::transform_between()
{
//idbassert(fGwip.rcWorkStack.size() >= 3);
if (fGwip.rcWorkStack.size() < 3)
{
fGwip.fatalParseError = true;
fGwip.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_NON_SUPPORT_SCALAR);
return NULL;
}
ReturnedColumn* op3 = fGwip.rcWorkStack.top();
fGwip.rcWorkStack.pop();
ReturnedColumn* op2 = fGwip.rcWorkStack.top();
fGwip.rcWorkStack.pop();
ReturnedColumn* op1 = fGwip.rcWorkStack.top();
fGwip.rcWorkStack.pop();
fColumn.reset(op1);
ParseTree* lhs = NULL;
ParseTree* rhs = NULL;
PredicateOperator* op_LE = new PredicateOperator("<=");
PredicateOperator* op_GE = new PredicateOperator(">=");
SubSelect* sub2 = dynamic_cast<SubSelect*>(op3);
fSub = (Item_subselect*)(fFunc->arguments()[2]);
if (sub2)
{
rhs = buildParseTree(op_LE);
delete sub2;
}
else
{
SOP sop;
sop.reset(op_LE);
rhs = new ParseTree(new SimpleFilter(sop, fColumn.get(), op3));
}
SubSelect* sub1 = dynamic_cast<SubSelect*>(op2);
fSub = (Item_subselect*)(fFunc->arguments()[1]);
if (sub1)
{
lhs = buildParseTree(op_GE);
delete sub1;
}
else
{
SOP sop;
sop.reset(op_GE);
lhs = new ParseTree(new SimpleFilter(sop, fColumn.get(), op2));
}
if (!rhs || !lhs)
{
fGwip.fatalParseError = true;
fGwip.parseErrorText = "non-supported scalar subquery";
fGwip.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_NON_SUPPORT_SCALAR);
return NULL;
}
ParseTree* pt = new ParseTree (new LogicOperator("and"));
pt->left(lhs);
pt->right(rhs);
return pt;
}
