private IrStmt mergeSTMTs(IrStmt s1, IrStmt s2, IrStmt s3)
{
if (nullSTMT(s1)) return mergeSTMTs(s2, s3);
if (nullSTMT(s2)) return mergeSTMTs(s1, s3);
IrStmtList sl = new IrStmtList();
sl.add(s1);
sl.add(mergeSTMTs(s2, s3));
return sl;
}
private int GetInitStmts(ClassRec c, IrStmtList stmts, IrTemp tmp)
{
ClassRec saveCurrClass;
VarRec v;
int varCnt = 0;
// Get init STMTs from inherited class
if (null != c.Parent())
{
varCnt = GetInitStmts(c.Parent(), stmts, tmp);
}
// Add init STMTs from this class
for (int i = 0; i < c.VarCnt(); i++)
{
v = c.GetClassVarAt(i);
if (null == v.Init())
{
stmts.add(ObjVarInitStmt(tmp, varCnt + i, v.Idx - 1, cZero));
}
else
{
saveCurrClass = currClass;
currClass = c;
IrExp e = v.Init().accept(this);
currClass = saveCurrClass;
stmts.add(ObjVarInitStmt(tmp, varCnt + i, v.Idx - 1, e));
}
}
return varCnt + c.VarCnt();
}
private IrStmt mergeSTMTs(IrStmt s1, IrStmt s2)
{
if (nullSTMT(s1)) return s2;
if (nullSTMT(s2)) return s1;
IrStmtList sl = new IrStmtList();
sl.add(s1);
sl.add(s2);
return sl;
}
// *** partial implementation, will be fixed in proj2 ****
// NewObj ---
// Id cid;
public IrExp visit(AstNewObj n)
{
// A NewObj node should be translated into a CALL to "malloc" with a single argument representing the size
// of the object, followed by a sequence of statements for initializing the object’s class variables.
// A special note: the initialization expressions saved in the the symbol table entry for this purpose are
// AST expressions, and need to be translated into IR expressions. Furthermore, this translation should be
// conducted in the proper scope environment — the IrgenVisitor variable currClass needs to point to the
// object’s class.
IrStmtList stmts = new IrStmtList();
// Calculate the size of the object
ClassRec classRec = symTable.GetClass(n.cid); // <get the object's ClassRec from symbol table>;
int numVars = GetNumObjVars(classRec);
// Construct malloc call node
IrExp size = new IrBinop(IrBinop.OP.MUL, new IrConst(numVars > 0 ? numVars : 1), cWordSize);
IrCall call = new IrCall(new IrName("malloc"), new IrExpList(size));
IrTemp tmp = new IrTemp(); // This TEMP will contain the location of the object variables
stmts.add(new IrMove(tmp, call)); // Move the results of the malloc call into the temp
GetInitStmts(classRec, stmts, tmp); // Recursively get object's variable initialization statements
return new IrEseq(stmts, tmp); // Construct resulting statement
}
private IrStmtList flattern(IrStmtList list)
{
IrStmtList sl = new IrStmtList();
for (int i = 0; i < list.size(); i++)
{
IrStmt s = (IrStmt)list.elementAt(i);
if (null != (s as IrStmtList))
{
sl.add(flattern((IrStmtList)s));
}
else
{
sl.add(s);
}
}
return sl;
}
// Relop ---
// int op;
// Exp e1, e2;
public IrExp visit(AstRelop n)
{
IrExp l = n.e1.accept(this);
IrExp r = n.e2.accept(this);
IrStmtList sl = new IrStmtList();
IrTemp tmp = new IrTemp();
IrName done = new IrName();
sl.add(new IrMove(tmp, cOne));
sl.add(new IrCJump(n.op, l, r, done));
sl.add(new IrMove(tmp, cZero));
sl.add(new IrLabel(done));
return new IrEseq(sl, tmp);
}
// NewArray ---
// int size;
public IrExp visit(AstNewArray n)
{
IrExp size = new IrConst(n.size);
IrStmtList sl = new IrStmtList();
IrName top = new IrName();
IrTemp array = new IrTemp();
IrTemp cnt = new IrTemp();
IrExp bound = new IrBinop(IrBinop.OP.MUL, new IrConst(n.size + 1), cWordSize);
sl.add(new IrMove(array, new IrCall(new IrName("malloc"), new IrExpList(bound))));
sl.add(new IrMove(new IrMem(array), size));
sl.add(new IrMove(cnt, new IrBinop(IrBinop.OP.ADD, array,
new IrBinop(IrBinop.OP.MUL, size, cWordSize))));
sl.add(new IrLabel(top));
sl.add(new IrMove(new IrMem(cnt), cZero));
sl.add(new IrMove(cnt, new IrBinop(IrBinop.OP.SUB, cnt, cWordSize)));
sl.add(new IrCJump(IrCJump.OP.GT, cnt, array, top));
return new IrEseq(sl, array);
}
// If ---
// Exp e;
// Stmt s1, s2;
public IrStmt visit(AstIf n)
{
IrName alt = new IrName();
IrStmtList sl = new IrStmtList();
IrExp exp = n.e.accept(this);
sl.add(new IrCJump(IrCJump.OP.EQ, exp, cZero, alt));
sl.add(n.s1.accept(this));
if (n.s2 == null)
{
sl.add(new IrLabel(alt));
}
else
{
IrName done = new IrName();
sl.add(new IrJump(done));
sl.add(new IrLabel(alt));
sl.add(n.s2.accept(this));
sl.add(new IrLabel(done));
}
return sl;
}
// While ---
// Exp e;
// Stmt s;
public IrStmt visit(AstWhile n)
{
IrName test = new IrName();
IrName done = new IrName();
IrStmtList sl = new IrStmtList();
sl.add(new IrLabel(test));
IrExp exp = n.e.accept(this);
sl.add(new IrCJump(IrCJump.OP.EQ, exp, cZero, done));
sl.add(n.s.accept(this));
sl.add(new IrJump(test));
sl.add(new IrLabel(done));
return sl;
}
// STATEMENTS
// StmtList ---
public IrStmtList visit(AstStmtList n)
{
IrStmtList sl = new IrStmtList();
for (int i = 0; i < n.Count(); i++)
sl.add(n[i].accept(this));
return sl;
}
// VarDeclList ---
public IrStmtList visit(AstVarDeclList n)
{
IrStmtList sl = new IrStmtList();
IrStmt s;
for (int i = 0; i < n.Count(); i++)
{
s = n[i].accept(this);
if (s != null)
sl.add(s);
}
if (sl.size() > 0)
return sl;
else
return null;
}
/* throws ParseException */
// *************************************************************************
// * Static
// *************************************************************************
public static IrFunc FUNC()
{
IrToken t; int vc, tc, ac; IrStmtList sl=new IrStmtList(); IrStmt s;
t = jj_consume_token(RegExpId.ID);
jj_consume_token(RegExpId.kw32);
jj_consume_token(RegExpId.kwVARCNT);
jj_consume_token(RegExpId.kw33);
vc = INT();
jj_consume_token(RegExpId.kw34);
jj_consume_token(RegExpId.kwTMPCNT);
jj_consume_token(RegExpId.kw33);
tc = INT();
jj_consume_token(RegExpId.kw34);
jj_consume_token(RegExpId.kwARGCNT);
jj_consume_token(RegExpId.kw33);
ac = INT();
jj_consume_token(RegExpId.kw35);
jj_consume_token(RegExpId.kw36);
// label_2:
while (true)
{
switch ((jj_ntk == RegExpId.UNDEFINED) ? jj_ntk_fn() : jj_ntk)
{
case RegExpId.kw44:
break;
default:
jj_la1[1] = jj_gen;
goto label_2a; // break label_2;
}
s = STMT();
sl.add(s);
}
label_2a:
jj_consume_token(RegExpId.kw37);
{if (true) return new IrFunc(t.image,vc,tc,ac,sl);}
throw new Error("Missing return statement in function");
}
public IrStmt visit(IrStmtList t)
{
IrStmtList stmts = new IrStmtList();
for (int i = 0; i < t.size(); i++)
{
IrStmt s = ((IrStmt)t.elementAt(i)).accept(this);
stmts.add(s);
}
return stmts;
}
private IrStmt mergeStmts(IrStmt s1, IrStmt s2)
{
if (s1 == null) return s2;
if (s2 == null) return s1;
IrStmtList sl = new IrStmtList();
sl.add(s1);
sl.add(s2);
return sl;
}