string CBackendx86::Operand(const CTac *op)
{
string operand;
// TODO
// return a string representing op
// hint: take special care of references (op of type CTacReference)
std::stringstream buffer ;
buffer << op ;
CScope *cs = GetScope();
CSymtab *st = cs->GetSymbolTable();
vector<CSymbol*> slist = st->GetSymbols();
vector< CSymbol * > symbols = st->GetSymbols() ;
//CTacName
if (st->FindSymbol(buffer.str()) != NULL){
operand = buffer.str() ;
}
//CTacConstant
else if (buffer.str()[0] > 47 && buffer.str()[0] < 58){
operand = Imm(atoi(buffer.str().c_str())) ;
}
//CTacReference
else {
}
return operand ;
}
CAstDesignator* CParser::ident(CAstScope *s)
{
//
// ident ::= letter { letter | digit }.
//
CToken t;
Consume(tIdent, &t);
CSymtab *symtab = s->GetSymbolTable();
const CSymbol *symbol = symtab->FindSymbol(t.GetValue(), sLocal);
if (!symbol) symbol = symtab->FindSymbol(t.GetValue(), sGlobal);
if (!symbol) SetError(t, "undeclared variable \"" + t.GetValue() + "\"");
return new CAstDesignator(t, symbol);
}
CAstStatCall* CParser::subroutineCall(CAstScope *s, CToken ident) {
//
// subroutineCall ::= ident "(" [ expression {"," expression} ] ")".
//
CToken t;
Consume(tLBrak);
CSymtab *symtab = s->GetSymbolTable();
CAstFunctionCall *call = NULL;
// Check undefined procedure/function call.
if(symtab->FindSymbol(ident.GetValue(), sLocal) == NULL && symtab->FindSymbol(ident.GetValue(), sGlobal) != NULL) {
// Check if symbol is procedure.
if(dynamic_cast<const CSymProc *>(symtab->FindSymbol(ident.GetValue(), sGlobal)) == NULL)
SetError(ident, "invalid procedure/function identifier.");
call = new CAstFunctionCall(ident, dynamic_cast<const CSymProc *>(symtab->FindSymbol(ident.GetValue(), sGlobal)));
}
else if(symtab->FindSymbol(ident.GetValue(), sLocal) != NULL) {
// Check if symbol is procedure.
if(dynamic_cast<const CSymProc *>(symtab->FindSymbol(ident.GetValue(), sLocal)) == NULL)
SetError(ident, "invalid procedure/function identifier.");
call = new CAstFunctionCall(ident, dynamic_cast<const CSymProc *>(symtab->FindSymbol(ident.GetValue(), sLocal)));
}
else
SetError(ident, "undefined identifier.");
// Add expressions.
if(isExpr(_scanner->Peek())) {
CAstExpression *expr = expression(s);
assert(expr != NULL);
// Arrays are addressed.
if(expr->GetType()->IsArray())
expr = new CAstSpecialOp(expr->GetToken(), opAddress, expr, NULL);
call->AddArg(expr);
while(_scanner->Peek().GetType() == tComma) {
Consume(tComma);
expr = expression(s);
assert(expr != NULL);
// Arrays are addressed.
if(expr->GetType()->IsArray())
expr = new CAstSpecialOp(expr->GetToken(), opAddress, expr, NULL);
call->AddArg(expr);
}
}
Consume(tRBrak);
return new CAstStatCall(ident, call);
}
void CBackendx86::EmitLocalData(CScope *scope) // initializes array's meta-data
{
assert(scope != NULL);
CSymtab* symtab = scope->GetSymbolTable();
vector<CSymbol*> slist = symtab->GetSymbols();
vector<CSymbol*>::iterator it;
for(it = slist.begin(); it != slist.end(); it++) {
const CArrayType* typ = dynamic_cast<const CArrayType*>((*it)->GetDataType());
if(typ != NULL && (*it)->GetSymbolType() == stLocal && (dynamic_cast<CSymParam*>(*it) == NULL)) {
// just initialize the arrays that are local and are not param
int offset = (*it)->GetOffset();
string base = (*it)->GetBaseRegister();
int dim = typ->GetNDim();
stringstream ss, ss2;
ss << "$" << dim << "," << offset << "(" << base << ")";
ss2 << "local array '" << (*it)->GetName() << "': " << dim << " dimensions";
EmitInstruction("movl", ss.str(), ss2.str()); // store the dimension meta-data
int dimcount = 1;
while(typ != NULL) {
stringstream ss, ss2;
offset += 4;
int n = typ->GetNElem();
ss << "$" << n << "," << offset << "(" << base << ")";
ss2 << " dimension " << dimcount << ": " << n << " elements";
EmitInstruction("movl", ss.str(), ss2.str()); // store the meta-data of length of each dimension
typ = dynamic_cast<const CArrayType*>(typ->GetInnerType());
dim++;
dimcount++;
}
}
}
}
void CBackendx86::EmitGlobalData(CScope *scope)
{
assert(scope != NULL);
// emit the globals for the current scope
CSymtab *st = scope->GetSymbolTable();
assert(st != NULL);
bool header = false;
vector<CSymbol*> slist = st->GetSymbols();
_out << dec;
size_t size = 0;
for (size_t i=0; i<slist.size(); i++) {
CSymbol *s = slist[i];
const CType *t = s->GetDataType();
if (s->GetSymbolType() == stGlobal) {
if (!header) {
_out << _ind << "# scope: " << scope->GetName() << endl;
header = true;
}
// insert alignment only when necessary
if ((t->GetAlign() > 1) && (size % t->GetAlign() != 0)) {
size += t->GetAlign() - size % t->GetAlign();
_out << setw(4) << " " << ".align "
<< right << setw(3) << t->GetAlign() << endl;
}
_out << left << setw(36) << s->GetName() + ":" << "# " << t << endl;
if (t->IsArray()) {
const CArrayType *a = dynamic_cast<const CArrayType*>(t);
assert(a != NULL);
int dim = a->GetNDim();
_out << setw(4) << " "
<< ".long " << right << setw(4) << dim << endl;
for (int d=0; d<dim; d++) {
assert(a != NULL);
_out << setw(4) << " "
<< ".long " << right << setw(4) << a->GetNElem() << endl;
a = dynamic_cast<const CArrayType*>(a->GetInnerType());
}
}
const CDataInitializer *di = s->GetData();
if (di != NULL) {
const CDataInitString *sdi = dynamic_cast<const CDataInitString*>(di);
assert(sdi != NULL); // only support string data initializers for now
_out << left << setw(4) << " "
<< ".asciz " << '"' << sdi->GetData() << '"' << endl;
} else {
_out << left << setw(4) << " "
<< ".skip " << dec << right << setw(4) << t->GetDataSize()
<< endl;
}
size += t->GetSize();
}
}
_out << endl;
// emit globals in subscopes (necessary if we support static local variables)
vector<CScope*>::const_iterator sit = scope->GetSubscopes().begin();
while (sit != scope->GetSubscopes().end()) EmitGlobalData(*sit++);
}
CAstStatAssign* CParser::assignment(CAstScope *s, CToken ident) {
//
// assignment ::= qualident ":=" expression.
// qualident ::= ident { "[" expression "]" }.
//
CToken t;
CAstDesignator *lhs = NULL;
CSymtab *symtab = s->GetSymbolTable();
if(_scanner->Peek().GetType() == tAssign) { // non-array case.
const CSymbol *tmpsym = symtab->FindSymbol(ident.GetValue(), sLocal);
if(tmpsym == NULL && symtab->FindSymbol(ident.GetValue(), sGlobal) != NULL) {
// Check if symbol is procedure.
if(dynamic_cast<const CSymProc *>(symtab->FindSymbol(ident.GetValue(), sGlobal)) != NULL) {
SetError(ident, "designator expected.");
}
lhs = new CAstDesignator(ident, symtab->FindSymbol(ident.GetValue(), sGlobal));
}
else if(tmpsym != NULL) {
// Check if symbol is procedure.
if(dynamic_cast<const CSymProc *>(tmpsym) != NULL) {
SetError(ident, "designator expected.");
}
lhs = new CAstDesignator(ident, symtab->FindSymbol(ident.GetValue(), sLocal));
}
else
SetError(ident, "undefined identifier.");
assert(lhs != NULL);
}
else if(_scanner->Peek().GetType() == tLSBrak) { // array case.
const CSymbol *tmpsym = symtab->FindSymbol(ident.GetValue(), sLocal);
CAstArrayDesignator *arraylhs;
if(tmpsym == NULL && symtab->FindSymbol(ident.GetValue(), sGlobal) != NULL) {
// Check if symbol is procedure.
if(dynamic_cast<const CSymProc *>(symtab->FindSymbol(ident.GetValue(), sGlobal)) != NULL) {
SetError(ident, "designator expected.");
}
arraylhs = new CAstArrayDesignator(ident, symtab->FindSymbol(ident.GetValue(), sGlobal));
}
else if(tmpsym != NULL) {
// Check if symbol is procedure.
if(dynamic_cast<const CSymProc *>(tmpsym) != NULL) {
SetError(ident, "designator expected.");
}
arraylhs = new CAstArrayDesignator(ident, symtab->FindSymbol(ident.GetValue(), sLocal));
}
else
SetError(ident, "undefined identifier.");
// multiple index.
while(_scanner->Peek().GetType() == tLSBrak) {
Consume(tLSBrak);
CAstExpression *expr = expression(s);
assert(expr != NULL);
arraylhs->AddIndex(expr);
Consume(tRSBrak);
}
arraylhs->IndicesComplete();
lhs = dynamic_cast<CAstDesignator *>(arraylhs);
assert(lhs != NULL);
}
CToken k;
Consume(tAssign, &k);
CAstExpression *rhs = expression(s);
assert(rhs != NULL);
return new CAstStatAssign(k, lhs, rhs);
}
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;
}