protected override bool DoDefineMembers()
{
TypeSpec bt;
bool has_task_return_type = false;
var istate_machine = Module.PredefinedTypes.IAsyncStateMachine;
MethodSpec set_statemachine;
if (return_type.IsCustomTaskType())
{
//
// TODO: Would be nice to cache all this on per-type basis
//
var btypes = Compiler.BuiltinTypes;
bt = return_type.MemberDefinition.GetAsyncMethodBuilder();
TypeSpec bt_inflated;
if (return_type.IsGeneric)
{
bt_inflated = bt.MakeGenericType(Module, bt.MemberDefinition.TypeParameters);
}
else
{
bt_inflated = bt;
}
var set_result_sign = MemberFilter.Method("SetResult", 0, ParametersCompiled.CreateFullyResolved(bt.MemberDefinition.TypeParameters), btypes.Void);
set_result = new PredefinedMember <MethodSpec> (Module, bt, set_result_sign).Resolve(Location);
var set_exception_sign = MemberFilter.Method("SetException", 0, ParametersCompiled.CreateFullyResolved(btypes.Exception), btypes.Void);
set_exception = new PredefinedMember <MethodSpec> (Module, bt, set_exception_sign).Resolve(Location);
var builder_factory_sign = MemberFilter.Method("Create", 0, ParametersCompiled.EmptyReadOnlyParameters, bt_inflated);
builder_factory = new PredefinedMember <MethodSpec> (Module, bt, builder_factory_sign).Resolve(Location);
if (builder_factory?.IsStatic == false)
{
throw new NotImplementedException("report better error message");
}
var builder_start_sign = MemberFilter.Method("Start", 1, new ParametersImported(
new [] {
new ParameterData(null, Parameter.Modifier.REF),
},
new [] {
new TypeParameterSpec(0, null, SpecialConstraint.None, Variance.None, null),
}, false),
btypes.Void);
builder_start = new PredefinedMember <MethodSpec> (Module, bt, builder_start_sign).Resolve(Location);
if (!istate_machine.Define())
{
return(false);
}
var set_statemachine_sign = MemberFilter.Method("SetStateMachine", 0, ParametersCompiled.CreateFullyResolved(istate_machine.TypeSpec), btypes.Void);
set_statemachine = new PredefinedMember <MethodSpec> (Module, bt, set_statemachine_sign).Resolve(Location);;
var task_sign = MemberFilter.Property("Task", return_type.MemberDefinition as TypeSpec);
task = new PredefinedMember <PropertySpec> (Module, bt, task_sign).Resolve(Location);
if (set_result == null || set_exception == null || builder_factory == null || builder_start == null || set_statemachine == null || task == null ||
!Module.PredefinedTypes.INotifyCompletion.Define())
{
return(false);
}
has_task_return_type = return_type.IsGeneric;
}
else
{
PredefinedType builder_type;
PredefinedMember <MethodSpec> bf;
PredefinedMember <MethodSpec> bs;
PredefinedMember <MethodSpec> sr;
PredefinedMember <MethodSpec> se;
PredefinedMember <MethodSpec> sm;
var pred_members = Module.PredefinedMembers;
if (return_type.Kind == MemberKind.Void)
{
builder_type = Module.PredefinedTypes.AsyncVoidMethodBuilder;
bf = pred_members.AsyncVoidMethodBuilderCreate;
bs = pred_members.AsyncVoidMethodBuilderStart;
sr = pred_members.AsyncVoidMethodBuilderSetResult;
se = pred_members.AsyncVoidMethodBuilderSetException;
sm = pred_members.AsyncVoidMethodBuilderSetStateMachine;
}
else if (return_type == Module.PredefinedTypes.Task.TypeSpec)
{
builder_type = Module.PredefinedTypes.AsyncTaskMethodBuilder;
bf = pred_members.AsyncTaskMethodBuilderCreate;
bs = pred_members.AsyncTaskMethodBuilderStart;
sr = pred_members.AsyncTaskMethodBuilderSetResult;
se = pred_members.AsyncTaskMethodBuilderSetException;
sm = pred_members.AsyncTaskMethodBuilderSetStateMachine;
task = pred_members.AsyncTaskMethodBuilderTask.Get();
}
else
{
builder_type = Module.PredefinedTypes.AsyncTaskMethodBuilderGeneric;
bf = pred_members.AsyncTaskMethodBuilderGenericCreate;
bs = pred_members.AsyncTaskMethodBuilderGenericStart;
sr = pred_members.AsyncTaskMethodBuilderGenericSetResult;
se = pred_members.AsyncTaskMethodBuilderGenericSetException;
sm = pred_members.AsyncTaskMethodBuilderGenericSetStateMachine;
task = pred_members.AsyncTaskMethodBuilderGenericTask.Get();
has_task_return_type = true;
}
set_result = sr.Get();
set_exception = se.Get();
builder_factory = bf.Get();
builder_start = bs.Get();
set_statemachine = sm.Get();
if (!builder_type.Define() || !istate_machine.Define() || set_result == null || builder_factory == null ||
set_exception == null || set_statemachine == null || builder_start == null ||
!Module.PredefinedTypes.INotifyCompletion.Define())
{
Report.Error(1993, Location,
"Cannot find compiler required types for asynchronous functions support. Are you targeting the wrong framework version?");
return(base.DoDefineMembers());
}
bt = builder_type.TypeSpec;
}
//
// Inflate generic Task types
//
if (has_task_return_type)
{
var task_return_type = return_type.TypeArguments;
if (mutator != null)
{
task_return_type = mutator.Mutate(task_return_type);
}
bt = bt.MakeGenericType(Module, task_return_type);
set_result = MemberCache.GetMember(bt, set_result);
set_exception = MemberCache.GetMember(bt, set_exception);
set_statemachine = MemberCache.GetMember(bt, set_statemachine);
if (task != null)
{
task = MemberCache.GetMember(bt, task);
}
}
builder = AddCompilerGeneratedField("$builder", new TypeExpression(bt, Location));
Field rfield;
if (has_task_return_type && HasAwaitInsideFinally)
{
//
// Special case async block with return value from finally clause. In such case
// we rewrite all return expresison stores to stfld to $return. Instead of treating
// returns outside of finally and inside of finally differently.
//
rfield = AddCompilerGeneratedField("$return", new TypeExpression(bt.TypeArguments [0], Location));
}
else
{
rfield = null;
}
var set_state_machine = new Method(this, new TypeExpression(Compiler.BuiltinTypes.Void, Location),
Modifiers.COMPILER_GENERATED | Modifiers.DEBUGGER_HIDDEN | Modifiers.PUBLIC,
new MemberName("SetStateMachine"),
ParametersCompiled.CreateFullyResolved(
new Parameter(new TypeExpression(istate_machine.TypeSpec, Location), "stateMachine", Parameter.Modifier.NONE, null, Location),
istate_machine.TypeSpec),
null);
ToplevelBlock block = new ToplevelBlock(Compiler, set_state_machine.ParameterInfo, Location);
block.IsCompilerGenerated = true;
set_state_machine.Block = block;
Members.Add(set_state_machine);
if (!base.DoDefineMembers())
{
return(false);
}
//
// Fabricates SetStateMachine method
//
// public void SetStateMachine (IAsyncStateMachine stateMachine)
// {
// $builder.SetStateMachine (stateMachine);
// }
//
var mg = MethodGroupExpr.CreatePredefined(set_statemachine, bt, Location);
mg.InstanceExpression = new FieldExpr(builder, Location);
var param_reference = block.GetParameterReference(0, Location);
param_reference.Type = istate_machine.TypeSpec;
param_reference.eclass = ExprClass.Variable;
var args = new Arguments(1);
args.Add(new Argument(param_reference));
set_state_machine.Block.AddStatement(new StatementExpression(new Invocation(mg, args)));
if (has_task_return_type)
{
if (rfield != null)
{
HoistedReturnValue = new FieldExpr(rfield, Location)
{
InstanceExpression = new CompilerGeneratedThis(CurrentType, Location.Null)
};
}
else
{
HoistedReturnValue = TemporaryVariableReference.Create(bt.TypeArguments [0], StateMachineMethod.Block, Location);
}
}
return(true);
}