public override bool Resolve (BlockContext ec)
{
expr = expr.Resolve (ec);
if (expr == null)
return false;
Report.Debug (64, "RESOLVE YIELD #1", this, ec, expr, expr.GetType (),
ec.CurrentAnonymousMethod, ec.CurrentIterator);
if (!CheckContext (ec, loc))
return false;
iterator = ec.CurrentIterator;
if (expr.Type != iterator.OriginalIteratorType) {
expr = Convert.ImplicitConversionRequired (
ec, expr, iterator.OriginalIteratorType, loc);
if (expr == null)
return false;
}
if (!ec.CurrentBranching.CurrentUsageVector.IsUnreachable)
unwind_protect = ec.CurrentBranching.AddResumePoint (this, loc, out resume_pc);
return true;
}
public override void EmitForDispose (EmitContext ec, Iterator iterator, Label end, bool have_dispatcher)
{
if (emitted_dispose)
return;
emitted_dispose = true;
Label end_of_try = ec.DefineLabel ();
// Ensure that the only way we can get into this code is through a dispatcher
if (have_dispatcher)
ec.Emit (OpCodes.Br, end);
ec.BeginExceptionBlock ();
ec.MarkLabel (dispose_try_block);
Label [] labels = null;
for (int i = 0; i < resume_points.Count; ++i) {
ResumableStatement s = (ResumableStatement) resume_points [i];
Label ret = s.PrepareForDispose (ec, end_of_try);
if (ret.Equals (end_of_try) && labels == null)
continue;
if (labels == null) {
labels = new Label [resume_points.Count];
for (int j = 0; j < i; ++j)
labels [j] = end_of_try;
}
labels [i] = ret;
}
if (labels != null) {
int j;
for (j = 1; j < labels.Length; ++j)
if (!labels [0].Equals (labels [j]))
break;
bool emit_dispatcher = j < labels.Length;
if (emit_dispatcher) {
//SymbolWriter.StartIteratorDispatcher (ec.ig);
ec.Emit (OpCodes.Ldloc, iterator.CurrentPC);
ec.EmitInt (first_resume_pc);
ec.Emit (OpCodes.Sub);
ec.Emit (OpCodes.Switch, labels);
//SymbolWriter.EndIteratorDispatcher (ec.ig);
}
foreach (ResumableStatement s in resume_points)
s.EmitForDispose (ec, iterator, end_of_try, emit_dispatcher);
}
ec.MarkLabel (end_of_try);
ec.BeginFinallyBlock ();
EmitFinallyBody (ec);
ec.EndExceptionBlock ();
}
public override bool Resolve (BlockContext ec)
{
// System.Reflection.Emit automatically emits a 'leave' at the end of a try clause
// So, ensure there's some IL code after this statement.
if (!code_follows && resume_points == null && ec.CurrentBranching.CurrentUsageVector.IsUnreachable)
ec.NeedReturnLabel ();
iter = ec.CurrentIterator;
return true;
}
public virtual void EmitForDispose (EmitContext ec, Iterator iterator, Label end, bool have_dispatcher)
{
}
public void WrapIntoIterator (IMethodData method, TypeContainer host, TypeSpec iterator_type, bool is_enumerable)
{
ParametersBlock pb = new ParametersBlock (this, ParametersCompiled.EmptyReadOnlyParameters, StartLocation);
pb.EndLocation = EndLocation;
pb.statements = statements;
var iterator = new Iterator (pb, method, host, iterator_type, is_enumerable);
am_storey = new IteratorStorey (iterator);
statements = new List<Statement> (1);
AddStatement (new Return (iterator, iterator.Location));
}
public IteratorStorey(Iterator iterator)
: base(iterator.Container.ParametersBlock, iterator.Host,
iterator.OriginalMethod as MemberBase, iterator.OriginalMethod.CurrentTypeParameters, "Iterator", MemberKind.Class)
{
this.Iterator = iterator;
}
public DisposeMethodStatement(Iterator iterator)
{
this.iterator = iterator;
this.loc = iterator.Location;
}
public IteratorStatement(Iterator iterator, Block original_block)
{
this.iterator = iterator;
this.original_block = original_block;
this.loc = iterator.Location;
}
public IteratorStorey (Iterator iterator)
: base (iterator.Container.ParametersBlock, iterator.Host,
iterator.OriginalMethod as MemberBase, iterator.GenericMethod == null ? null : iterator.GenericMethod.CurrentTypeParameters, "Iterator")
{
this.Iterator = iterator;
}
public static void CreateIterator (IMethodData method, TypeContainer parent, int modifiers, CompilerContext ctx)
{
bool is_enumerable;
Type iterator_type;
Type ret = method.ReturnType;
if (ret == null)
return;
if (!CheckType (ret, out iterator_type, out is_enumerable)) {
ctx.Report.Error (1624, method.Location,
"The body of `{0}' cannot be an iterator block " +
"because `{1}' is not an iterator interface type",
method.GetSignatureForError (),
TypeManager.CSharpName (ret));
return;
}
ParametersCompiled parameters = method.ParameterInfo;
for (int i = 0; i < parameters.Count; i++) {
Parameter p = parameters [i];
Parameter.Modifier mod = p.ModFlags;
if ((mod & Parameter.Modifier.ISBYREF) != 0) {
ctx.Report.Error (1623, p.Location,
"Iterators cannot have ref or out parameters");
return;
}
if (p is ArglistParameter) {
ctx.Report.Error (1636, method.Location,
"__arglist is not allowed in parameter list of iterators");
return;
}
if (parameters.Types [i].IsPointer) {
ctx.Report.Error (1637, p.Location,
"Iterators cannot have unsafe parameters or " +
"yield types");
return;
}
}
if ((modifiers & Modifiers.UNSAFE) != 0) {
ctx.Report.Error (1629, method.Location, "Unsafe code may not appear in iterators");
return;
}
Iterator iter = new Iterator (ctx, method, parent, iterator_type, is_enumerable);
iter.Storey.DefineType ();
}
public FlowBranchingIterator StartFlowBranching (Iterator iterator)
{
FlowBranchingIterator branching = new FlowBranchingIterator (CurrentBranching, iterator);
current_flow_branching = branching;
return branching;
}
public MoveNextMethodStatement(Iterator iterator)
{
this.iterator = iterator;
this.loc = iterator.Location;
}
public IteratorStorey(Iterator iterator)
: base(iterator.Container.ParametersBlock, iterator.Host,
iterator.OriginalMethod as MemberBase, iterator.GenericMethod == null ? null : iterator.GenericMethod.CurrentTypeParameters, "Iterator")
{
this.Iterator = iterator;
}
public DisposeMethodStatement(Iterator iterator)
{
this.iterator = iterator;
this.loc = iterator.Location;
}
protected override bool DoResolve(BlockContext ec)
{
iterator = ec.CurrentIterator;
return(Yield.CheckContext(ec, loc));
}
public FlowBranchingIterator (FlowBranching parent, Iterator iterator)
: base (parent, BranchingType.Iterator, SiblingType.Block, iterator.Block, iterator.Location)
{
this.iterator = iterator;
}
protected override bool DoResolve(BlockContext ec)
{
iterator = ec.CurrentIterator;
return Yield.CheckContext (ec, loc);
}
public MoveNextMethodStatement (Iterator iterator)
{
this.iterator = iterator;
this.loc = iterator.Location;
}
public IteratorStorey(Iterator iterator)
: base(iterator.Container.Toplevel, iterator.Host,
iterator.OriginalMethod as MemberBase, iterator.GenericMethod, "Iterator")
{
this.Iterator = iterator;
}
//
// Reformats this block to be top-level iterator block
//
public IteratorStorey ChangeToIterator (Iterator iterator, ToplevelBlock source)
{
IsIterator = true;
// Creates block with original statements
AddStatement (new IteratorStatement (iterator, new Block (this, source)));
source.statements = new List<Statement> (1);
source.AddStatement (new Return (iterator, iterator.Location));
source.IsIterator = false;
IteratorStorey iterator_storey = new IteratorStorey (iterator);
source.am_storey = iterator_storey;
return iterator_storey;
}
public FlowBranchingIterator StartFlowBranching (Iterator iterator, FlowBranching parent)
{
FlowBranchingIterator branching = new FlowBranchingIterator (parent, iterator);
current_flow_branching = branching;
return branching;
}
public TryFinallyBlockProxyStatement(Iterator iterator, TryFinallyBlock block)
{
this.iterator = iterator;
this.block = block;
}
