public Instr Emit_Asgn(AsgnNode node)
{
// 先编译右值
node.cdr.Compile(this);
// 然后把堆栈中的值赋给左值
return(GenAssignment(node.car, vm.CurrentScope.sp));
}
private void GenAssignment(CodeGenScope s, AstNode tree, int sp, int val)
{
int idx;
AsgnNode asgnNode = tree.As <AsgnNode> ();
Gen(s, asgnNode.cdr, VAL);
Pop(s);
switch (asgnNode.car.type)
{
case AstNodeType.GVAR:
idx = NewSym(s, asgnNode.car.As <GlobalVarNode>().name);
GenOp_2(s, OpCode.SetGV, sp, idx);
break;
case AstNodeType.ARG:
case AstNodeType.LVAR:
idx = s.FindLocalVarIdx(asgnNode.car.As <SymNode> ().name);
if (idx != -1)
{
if (idx != sp)
{
GenMove(s, idx, sp, val == 1);
if (val == 1 && s.parser.on_eval)
{
GenOp_0(s, OpCode.Nop);
}
}
break;
}
else
{
int lv = 0;
CodeGenScope up = s.prev;
while (up != null)
{
idx = up.FindLocalVarIdx(asgnNode.car.As <SymNode> ().name);
if (idx != -1)
{
GenOp_3(s, OpCode.SetUpVar, sp, idx, lv);
break;
}
lv++;
up = up.prev;
}
}
break;
case AstNodeType.IVAR:
idx = NewSym(s, nsym(asgnNode.car));
GenOp_2(s, OpCode.SetIV, sp, idx);
break;
case AstNodeType.CVAR:
idx = NewSym(s, nsym(asgnNode.car));
GenOp_2(s, OpCode.SetCV, sp, idx);
break;
case AstNodeType.CONST:
idx = NewSym(s, nsym(asgnNode.car));
GenOp_2(s, OpCode.SetConst, sp, idx);
break;
case AstNodeType.COLON2:
// TODO:
break;
case AstNodeType.CALL:
case AstNodeType.SCALL:
Push(s);
GenCall(s, asgnNode.car, sp, NOVAL, asgnNode.car.type == AstNodeType.SCALL);
Pop(s);
if (val != NOVAL)
{
GenMove(s, s.sp, sp, false);
}
break;
case AstNodeType.MASGN:
// TODO:
break;
case AstNodeType.NIL:
break;
default:
Console.WriteLine($"unknown lhs {asgnNode.car.type}\n");
break;
}
if (val != NOVAL)
{
Push(s);
}
}
