public BoundGlobalVariableStatement Update(BoundVariableRef variable)
{
if (variable == Variable)
{
return(this);
}
else
{
return(new BoundGlobalVariableStatement(variable));
}
}
public BoundGlobalVariableStatement(BoundVariableRef variable)
{
Variable = variable;
}
public virtual void VisitVariableRef(BoundVariableRef x)
{
}
public virtual TResult VisitVariableRef(BoundVariableRef x) => DefaultVisitOperation(x);
public virtual void VisitVariableRef(BoundVariableRef x)
{
}
public override void VisitVariableRef(BoundVariableRef x)
{
if (x.Name.IsDirect)
{
// direct variable access:
var name = x.Name.NameValue.Value;
// bind variable place
x.Variable = Routine.LocalsTable.BindVariable(x.Name.NameValue, State.GetVarKind(x.Name.NameValue));
// update state
if (x.Access.IsRead)
{
State.SetVarUsed(name);
var vartype = State.GetVarType(name);
if (vartype.IsVoid || x.Variable.VariableKind == VariableKind.GlobalVariable)
{
// in global code or in case of undefined variable,
// assume the type is mixed (unspecified).
// In global code, the type of variable cannot be determined by type analysis, it can change between every two operations (this may be improved by better flow analysis).
vartype = TypeRefMask.AnyType;
}
if (x.Access.IsEnsure)
{
if (x.Access.IsReadRef)
{
State.SetVarRef(name);
vartype.IsRef = true;
}
if (x.Access.EnsureObject && !IsClassOnly(vartype))
{
vartype |= TypeCtx.GetSystemObjectTypeMask();
}
if (x.Access.EnsureArray && !IsArrayOnly(vartype))
{
vartype |= TypeCtx.GetArrayTypeMask();
}
State.SetVarInitialized(name);
State.SetVar(name, vartype);
}
x.TypeRefMask = vartype;
}
if (x.Access.IsWrite)
{
//
State.SetVarInitialized(name);
State.SetVar(name, x.Access.WriteMask);
State.LTInt64Max(name, false);
x.TypeRefMask = x.Access.WriteMask;
if (x.Access.IsWriteRef)
{
State.SetVarRef(name);
x.TypeRefMask = x.TypeRefMask.WithRefFlag;
}
//
if (x.Variable.VariableKind == VariableKind.StaticVariable)
{
// analysis has to be started over // TODO: start from the block which declares the static local variable
var startBlock = Routine.ControlFlowGraph.Start;
var startState = startBlock.FlowState;
var oldVar = startState.GetVarType(name);
if (oldVar != x.TypeRefMask)
{
startState.SetVar(name, x.TypeRefMask);
this.Worklist.Enqueue(startBlock);
}
}
}
if (x.Access.IsUnset)
{
State.SetVar(name, 0);
State.LTInt64Max(name, false);
x.TypeRefMask = 0;
}
}
else
{
// indirect variable access:
Routine.Flags |= RoutineFlags.HasIndirectVar;
Accept(x.Name.NameExpression);
// bind variable place
if (x.Variable == null)
{
x.Variable = new BoundIndirectLocal(x.Name.NameExpression);
}
// update state
if (x.Access.IsRead)
{
State.FlowContext.SetAllUsed();
}
if (x.Access.IsWrite)
{
State.SetAllInitialized();
}
if (x.Access.IsUnset)
{
}
return;
}
}
