CTacAddr* CAstStatIf::ToTac(CCodeBlock *cb, CTacLabel *next)
{
CTacLabel* truelabel = cb->CreateLabel("if_true"); // true label
CTacLabel* falselabel = cb->CreateLabel("if_false"); // false label
_cond->ToTac(cb, truelabel, falselabel); // calculate condition
CAstStatement *s = _ifBody;
cb->AddInstr(truelabel); // install true label
while(s != NULL) { // TAC of ifBody
CTacLabel* tempnext = cb->CreateLabel();
s->ToTac(cb, tempnext);
cb->AddInstr(tempnext);
s = s->GetNext();
}
cb->AddInstr(new CTacInstr(opGoto, next)); // skip to next
s = _elseBody;
cb->AddInstr(falselabel); // install false label
while(s != NULL) { // TAC of elseBody
CTacLabel* tempnext = cb->CreateLabel();
s->ToTac(cb, tempnext);
cb->AddInstr(tempnext);
s = s->GetNext();
}
cb->AddInstr(new CTacInstr(opGoto, next)); // goto next
return NULL;
}
CTacAddr* CAstStatWhile::ToTac(CCodeBlock *cb, CTacLabel *next)
{
assert(cb != NULL && next != NULL);
CAstExpression *cond = GetCondition();
CAstStatement *body = GetBody();
CTacLabel *while_cond = cb->CreateLabel("while_cond");
CTacLabel *c_true = cb->CreateLabel("while_body");
// while condition begins
cb->AddInstr(while_cond);
CTacAddr *tCond = cond->ToTac(cb, c_true, next);
if(dynamic_cast<CAstDesignator*>(cond)) { // if cond is a single boolean
cb->AddInstr(new CTacInstr(opEqual, c_true, tCond, new CTacConst(1)));
cb->AddInstr(new CTacInstr(opGoto, next));
}
// while body starts..
cb->AddInstr(c_true);
while(body) {
CTacLabel *while_next = cb->CreateLabel("while_next");
body->ToTac(cb, while_next);
cb->AddInstr(while_next);
body = body->GetNext();
}
cb->AddInstr(new CTacInstr(opGoto, while_cond));
return NULL;
}
CTacAddr* CAstStatIf::ToTac(CCodeBlock *cb, CTacLabel *next)
{
assert(cb != NULL && next != NULL);
CAstExpression *cond = GetCondition();
CAstStatement *ifBody = GetIfBody();
CAstStatement *elseBody = GetElseBody();
CTacLabel *c_true = cb->CreateLabel("if_true");
CTacLabel *c_false = cb->CreateLabel("if_false");
// starting with translate condition
CTacAddr *tCond = cond->ToTac(cb, c_true, c_false);
if(dynamic_cast<CAstDesignator*>(cond)) { // if cond is a single boolean
cb->AddInstr(new CTacInstr(opEqual, c_true, tCond, new CTacConst(1)));
cb->AddInstr(new CTacInstr(opGoto, c_false));
}
// if_body starts..
cb->AddInstr(c_true);
while(ifBody) {
CTacLabel *if_next = cb->CreateLabel("if_next");
ifBody->ToTac(cb, if_next);
cb->AddInstr(if_next);
ifBody = ifBody->GetNext();
}
cb->AddInstr(new CTacInstr(opGoto, next));
// if else_body exists, else_body starts..
cb->AddInstr(c_false);
if(elseBody) {
while(elseBody) {
CTacLabel *else_next = cb->CreateLabel("else_next");
elseBody->ToTac(cb, else_next);
cb->AddInstr(else_next);
elseBody = elseBody->GetNext();
}
cb->AddInstr(new CTacInstr(opGoto, next));
}
return NULL;
}
CTacAddr* CAstScope::ToTac(CCodeBlock *cb)
{
assert (cb != NULL);
CAstStatement *s = GetStatementSequence();
while(s != NULL) { // statements -> TAC. connect each by "next" label
CTacLabel *next = cb->CreateLabel();
s->ToTac(cb, next);
cb->AddInstr(next);
s = s->GetNext();
}
cb->CleanupControlFlow(); // clean up control flow
return NULL;
}
CTacAddr* CAstScope::ToTac(CCodeBlock *cb)
{
assert(cb != NULL);
CAstStatement *s = GetStatementSequence();
// ToTac for all statement sequence.
while (s != NULL) {
CTacLabel *next = cb->CreateLabel();
s->ToTac(cb, next);
cb->AddInstr(next);
s = s->GetNext();
}
// clean up all unnecessary labels.
cb->CleanupControlFlow();
return NULL;
}
CTacAddr* CAstStatWhile::ToTac(CCodeBlock *cb, CTacLabel *next)
{
CTacLabel* lcond = cb->CreateLabel("while_cond"); // condition label
CTacLabel* lbody = cb->CreateLabel("while_body"); // body label
cb->AddInstr(lcond); // install condition label
_cond->ToTac(cb, lbody, next);
cb->AddInstr(lbody);
CAstStatement *s = _body;
while(s != NULL) {
CTacLabel *tempnext = cb->CreateLabel();
s->ToTac(cb, tempnext);
cb->AddInstr(tempnext);
s = s->GetNext();
}
cb->AddInstr(new CTacInstr(opGoto, lcond));
return NULL;
}