-//
+//
// async.cs: Asynchronous functions
//
// Author:
// Marek Safar (marek.safar@gmail.com)
//
+// Dual licensed under the terms of the MIT X11 or GNU GPL
+//
// Copyright 2011 Novell, Inc.
+// Copyright 2011 Xamarin Inc.
//
using System;
using System.Collections.Generic;
using System.Linq;
+using System.Collections;
+
#if STATIC
using IKVM.Reflection.Emit;
#else
namespace Mono.CSharp
{
- class Await : YieldStatement<AsyncInitializer>
+ public class Await : ExpressionStatement
+ {
+ Expression expr;
+ AwaitStatement stmt;
+
+ public Await (Expression expr, Location loc)
+ {
+ this.expr = expr;
+ this.loc = loc;
+ }
+
+ public Expression Expr {
+ get {
+ return expr;
+ }
+ }
+
+ protected override void CloneTo (CloneContext clonectx, Expression target)
+ {
+ var t = (Await) target;
+
+ t.expr = expr.Clone (clonectx);
+ }
+
+ public override Expression CreateExpressionTree (ResolveContext ec)
+ {
+ throw new NotImplementedException ("ET");
+ }
+
+ public override bool ContainsEmitWithAwait ()
+ {
+ return true;
+ }
+
+ protected override Expression DoResolve (ResolveContext rc)
+ {
+ if (rc.HasSet (ResolveContext.Options.LockScope)) {
+ rc.Report.Error (1996, loc,
+ "The `await' operator cannot be used in the body of a lock statement");
+ }
+
+ if (rc.HasSet (ResolveContext.Options.ExpressionTreeConversion)) {
+ rc.Report.Error (1989, loc, "An expression tree cannot contain an await operator");
+ return null;
+ }
+
+ if (rc.IsUnsafe) {
+ rc.Report.Error (4004, loc,
+ "The `await' operator cannot be used in an unsafe context");
+ }
+
+ var bc = (BlockContext) rc;
+
+ stmt = new AwaitStatement (expr, loc);
+ if (!stmt.Resolve (bc))
+ return null;
+
+ type = stmt.ResultType;
+ eclass = ExprClass.Variable;
+ return this;
+ }
+
+ public override void Emit (EmitContext ec)
+ {
+ stmt.EmitPrologue (ec);
+ stmt.Emit (ec);
+ }
+
+ public override Expression EmitToField (EmitContext ec)
+ {
+ stmt.EmitPrologue (ec);
+ return stmt.GetResultExpression (ec);
+ }
+
+ public void EmitAssign (EmitContext ec, FieldExpr field)
+ {
+ stmt.EmitPrologue (ec);
+ field.InstanceExpression.Emit (ec);
+ stmt.Emit (ec);
+ }
+
+ public override void EmitStatement (EmitContext ec)
+ {
+ stmt.EmitStatement (ec);
+ }
+
+ public override object Accept (StructuralVisitor visitor)
+ {
+ return visitor.Visit (this);
+ }
+ }
+
+ class AwaitStatement : YieldStatement<AsyncInitializer>
{
sealed class AwaitableMemberAccess : MemberAccess
{
protected override void Error_TypeDoesNotContainDefinition (ResolveContext rc, TypeSpec type, string name)
{
- Error_WrongGetAwaiter (rc, loc, type);
+ Error_OperatorCannotBeApplied (rc, type);
}
protected override void Error_OperatorCannotBeApplied (ResolveContext rc, TypeSpec type)
{
- rc.Report.Error (1991, loc, "Cannot await `{0}' expression", type.GetSignatureForError ());
+ rc.Report.Error (4001, loc, "Cannot await `{0}' expression", type.GetSignatureForError ());
+ }
+ }
+
+ sealed class GetResultInvocation : Invocation
+ {
+ public GetResultInvocation (MethodGroupExpr mge, Arguments arguments)
+ : base (null, arguments)
+ {
+ mg = mge;
+ type = mg.BestCandidateReturnType;
+ }
+
+ public override Expression EmitToField (EmitContext ec)
+ {
+ return this;
}
}
Field awaiter;
- PropertyExpr is_completed;
+ PropertySpec is_completed;
MethodSpec on_completed;
+ MethodSpec get_result;
+ TypeSpec type;
+ TypeSpec result_type;
- public Await (Expression expr, Location loc)
+ public AwaitStatement (Expression expr, Location loc)
: base (expr, loc)
{
}
- public override Expression CreateExpressionTree (ResolveContext ec)
- {
- throw new NotImplementedException ();
+ #region Properties
+
+ bool IsDynamic {
+ get {
+ return is_completed == null;
+ }
+ }
+
+ public TypeSpec Type {
+ get {
+ return type;
+ }
+ }
+
+ public TypeSpec ResultType {
+ get {
+ return result_type;
+ }
}
+ #endregion
+
protected override void DoEmit (EmitContext ec)
+ {
+ GetResultExpression (ec).Emit (ec);
+ }
+
+ public Expression GetResultExpression (EmitContext ec)
+ {
+ var fe_awaiter = new FieldExpr (awaiter, loc);
+ fe_awaiter.InstanceExpression = new CompilerGeneratedThis (ec.CurrentType, loc);
+
+ //
+ // result = awaiter.GetResult ();
+ //
+ if (IsDynamic) {
+ var rc = new ResolveContext (ec.MemberContext);
+ return new Invocation (new MemberAccess (fe_awaiter, "GetResult"), new Arguments (0)).Resolve (rc);
+ } else {
+ var mg_result = MethodGroupExpr.CreatePredefined (get_result, fe_awaiter.Type, loc);
+ mg_result.InstanceExpression = fe_awaiter;
+
+ return new GetResultInvocation (mg_result, new Arguments (0));
+ }
+ }
+
+ public void EmitPrologue (EmitContext ec)
{
var fe_awaiter = new FieldExpr (awaiter, loc);
fe_awaiter.InstanceExpression = new CompilerGeneratedThis (ec.CurrentType, loc);
//
fe_awaiter.EmitAssign (ec, expr, false, false);
- is_completed.InstanceExpression = fe_awaiter;
- is_completed.EmitBranchable (ec, resume_point, true);
+ Label skip_continuation = ec.DefineLabel ();
- base.DoEmit (ec);
+ Expression completed_expr;
+ if (IsDynamic) {
+ var rc = new ResolveContext (ec.MemberContext);
- var mg_completed = MethodGroupExpr.CreatePredefined (on_completed, fe_awaiter.Type, loc);
- mg_completed.InstanceExpression = fe_awaiter;
+ Arguments dargs = new Arguments (1);
+ dargs.Add (new Argument (fe_awaiter));
+ completed_expr = new DynamicMemberBinder ("IsCompleted", dargs, loc).Resolve (rc);
+ } else {
+ var pe = PropertyExpr.CreatePredefined (is_completed, loc);
+ pe.InstanceExpression = fe_awaiter;
+ completed_expr = pe;
+ }
- var args = new Arguments (1);
- var storey = (AsyncTaskStorey) machine_initializer.Storey;
- var fe_cont = new FieldExpr (storey.Continuation, loc);
- fe_cont.InstanceExpression = new CompilerGeneratedThis (ec.CurrentType, loc);
+ completed_expr.EmitBranchable (ec, skip_continuation, true);
- args.Add (new Argument (fe_cont));
+ base.DoEmit (ec);
//
- // awaiter.OnCompleted (continuation);
+ // The stack has to be empty before calling await continuation. We handle this
+ // by lifting values which would be left on stack into class fields. The process
+ // is quite complicated and quite hard to test because any expression can possibly
+ // leave a value on the stack.
//
- mg_completed.EmitCall (ec, args);
+ // Following assert fails when some of expression called before is missing EmitToField
+ // or parent expression fails to find await in children expressions
+ //
+ ec.AssertEmptyStack ();
+
+ var storey = (AsyncTaskStorey) machine_initializer.Storey;
+ var cont_field = storey.EmitContinuationInitialization (ec);
+
+ var args = new Arguments (1);
+ args.Add (new Argument (cont_field));
+
+ if (IsDynamic) {
+ var rc = new ResolveContext (ec.MemberContext);
+ var mg_expr = new Invocation (new MemberAccess (fe_awaiter, "OnCompleted"), args).Resolve (rc);
+
+ ExpressionStatement es = (ExpressionStatement) mg_expr;
+ es.EmitStatement (ec);
+ } else {
+ var mg_completed = MethodGroupExpr.CreatePredefined (on_completed, fe_awaiter.Type, loc);
+ mg_completed.InstanceExpression = fe_awaiter;
+
+ //
+ // awaiter.OnCompleted (continuation);
+ //
+ mg_completed.EmitCall (ec, args);
+ }
+
+ // Return ok
+ machine_initializer.EmitLeave (ec, unwind_protect);
+
+ ec.MarkLabel (resume_point);
+ ec.MarkLabel (skip_continuation);
}
- static void Error_WrongGetAwaiter (ResolveContext rc, Location loc, TypeSpec type)
+ public void EmitStatement (EmitContext ec)
{
- rc.Report.Error (1986, loc,
- "The `await' operand type `{0}' must have suitable GetAwaiter method",
- type.GetSignatureForError ());
+ EmitPrologue (ec);
+ Emit (ec);
+
+ if (ResultType.Kind != MemberKind.Void) {
+ var storey = (AsyncTaskStorey) machine_initializer.Storey;
+
+ if (storey.HoistedReturn != null)
+ storey.HoistedReturn.EmitAssign (ec);
+ else
+ ec.Emit (OpCodes.Pop);
+ }
}
void Error_WrongAwaiterPattern (ResolveContext rc, TypeSpec awaiter)
{
- rc.Report.Error (1999, loc, "The awaiter type `{0}' must have suitable IsCompleted, OnCompleted, and GetResult members",
+ rc.Report.Error (4011, loc, "The awaiter type `{0}' must have suitable IsCompleted, OnCompleted, and GetResult members",
awaiter.GetSignatureForError ());
}
if (!base.Resolve (bc))
return false;
+ Arguments args = new Arguments (0);
+
+ type = expr.Type;
+
//
- // The task t is of type dynamic
+ // The await expression is of dynamic type
//
- if (expr.Type.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
- throw new NotImplementedException ("dynamic await");
+ if (type.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
+ result_type = type;
+
+ awaiter = ((AsyncTaskStorey) machine_initializer.Storey).AddAwaiter (type, loc);
+
+ expr = new Invocation (new MemberAccess (expr, "GetAwaiter"), args).Resolve (bc);
+ return true;
+ }
//
// Check whether the expression is awaitable
if (ama == null)
return false;
- Arguments args = new Arguments (0);
-
var errors_printer = new SessionReportPrinter ();
var old = bc.Report.SetPrinter (errors_printer);
ama = new Invocation (ama, args).Resolve (bc);
+ bc.Report.SetPrinter (old);
if (errors_printer.ErrorsCount > 0 || !MemberAccess.IsValidDotExpression (ama.Type)) {
- bc.Report.SetPrinter (old);
- Error_WrongGetAwaiter (bc, loc, expr.Type);
+ bc.Report.Error (1986, expr.Location,
+ "The `await' operand type `{0}' must have suitable GetAwaiter method",
+ expr.Type.GetSignatureForError ());
+
return false;
}
- var awaiter_type = expr.Type;
+ var awaiter_type = ama.Type;
awaiter = ((AsyncTaskStorey) machine_initializer.Storey).AddAwaiter (awaiter_type, loc);
+ expr = ama;
+
//
- // bool IsCompleted { get; }
+ // Predefined: bool IsCompleted { get; }
//
- var is_completed_ma = new MemberAccess (expr, "IsCompleted").Resolve (bc);
- if (is_completed_ma != null) {
- is_completed = is_completed_ma as PropertyExpr;
- if (is_completed != null && is_completed.Type.BuiltinType == BuiltinTypeSpec.Type.Bool && is_completed.IsInstance && is_completed.Getter != null) {
- // valid
- } else {
- bc.Report.SetPrinter (old);
- Error_WrongAwaiterPattern (bc, awaiter_type);
- return false;
- }
- }
+ is_completed = MemberCache.FindMember (awaiter_type, MemberFilter.Property ("IsCompleted", bc.Module.Compiler.BuiltinTypes.Bool),
+ BindingRestriction.InstanceOnly) as PropertySpec;
- if (errors_printer.ErrorsCount > 0) {
- bc.Report.SetPrinter (old);
+ if (is_completed == null || !is_completed.HasGet) {
Error_WrongAwaiterPattern (bc, awaiter_type);
return false;
}
//
- // void OnCompleted (Action)
+ // Predefined: OnCompleted (Action)
//
if (bc.Module.PredefinedTypes.Action.Define ()) {
on_completed = MemberCache.FindMember (awaiter_type, MemberFilter.Method ("OnCompleted", 0,
}
}
+ //
+ // Predefined: GetResult ()
+ //
+ // The method return type is also result type of await expression
+ //
+ get_result = MemberCache.FindMember (awaiter_type, MemberFilter.Method ("GetResult", 0,
+ ParametersCompiled.EmptyReadOnlyParameters, null),
+ BindingRestriction.InstanceOnly) as MethodSpec;
+
+ if (get_result == null) {
+ Error_WrongAwaiterPattern (bc, awaiter_type);
+ return false;
+ }
+
+ result_type = get_result.ReturnType;
+
return true;
}
}
public class AsyncInitializer : StateMachineInitializer
{
- public AsyncInitializer (ParametersBlock block, TypeContainer host)
- : base (block, host, host.Compiler.BuiltinTypes.Void)
+ TypeInferenceContext return_inference;
+
+ public AsyncInitializer (ParametersBlock block, TypeDefinition host, TypeSpec returnType)
+ : base (block, host, returnType)
{
}
+ #region Properties
+
public override string ContainerType {
get {
return "async state machine block";
}
}
- public static void Create (ParametersBlock block, TypeContainer host)
+ public Block OriginalBlock {
+ get {
+ return block.Parent;
+ }
+ }
+
+ public TypeInferenceContext ReturnTypeInference {
+ get {
+ return return_inference;
+ }
+ }
+
+ #endregion
+
+ public static void Create (IMemberContext context, ParametersBlock block, ParametersCompiled parameters, TypeDefinition host, TypeSpec returnType, Location loc)
{
- var init = block.WrapIntoAsyncTask (host);
- init.type = host.Compiler.BuiltinTypes.Void;
+ for (int i = 0; i < parameters.Count; i++) {
+ Parameter p = parameters[i];
+ Parameter.Modifier mod = p.ModFlags;
+ if ((mod & Parameter.Modifier.ISBYREF) != 0) {
+ host.Compiler.Report.Error (1988, p.Location,
+ "Async methods cannot have ref or out parameters");
+ return;
+ }
+
+ if (p is ArglistParameter) {
+ host.Compiler.Report.Error (4006, p.Location,
+ "__arglist is not allowed in parameter list of async methods");
+ return;
+ }
+
+ if (parameters.Types[i].IsPointer) {
+ host.Compiler.Report.Error (4005, p.Location,
+ "Async methods cannot have unsafe parameters");
+ return;
+ }
+ }
+
+ if (!block.HasAwait) {
+ host.Compiler.Report.Warning (1998, 1, loc,
+ "Async block lacks `await' operator and will run synchronously");
+ }
+
+ block.WrapIntoAsyncTask (context, host, returnType);
+ }
+
+ protected override BlockContext CreateBlockContext (ResolveContext rc)
+ {
+ var ctx = base.CreateBlockContext (rc);
+ var lambda = rc.CurrentAnonymousMethod as LambdaMethod;
+ if (lambda != null)
+ return_inference = lambda.ReturnTypeInference;
+
+ ctx.StartFlowBranching (this, rc.CurrentBranching);
+ return ctx;
+ }
+
+ public override Expression CreateExpressionTree (ResolveContext ec)
+ {
+ return base.CreateExpressionTree (ec);
}
public override void Emit (EmitContext ec)
throw new NotImplementedException ();
}
+ protected override void EmitMoveNextEpilogue (EmitContext ec)
+ {
+ var storey = (AsyncTaskStorey) Storey;
+ storey.EmitSetResult (ec);
+ }
+
public override void EmitStatement (EmitContext ec)
{
+ var storey = (AsyncTaskStorey) Storey;
storey.Instance.Emit (ec);
- ec.Emit (OpCodes.Call, storey.StateMachineMethod.Spec);
+
+ var move_next_entry = storey.StateMachineMethod.Spec;
+ if (storey.MemberName.Arity > 0) {
+ move_next_entry = MemberCache.GetMember (storey.Instance.Type, move_next_entry);
+ }
+
+ ec.Emit (OpCodes.Call, move_next_entry);
+
+ //
+ // Emits return <async-storey-instance>.$builder.Task;
+ //
+ if (storey.Task != null) {
+ var builder_field = storey.Builder.Spec;
+ var task_get = storey.Task.Get;
+
+ if (storey.MemberName.Arity > 0) {
+ builder_field = MemberCache.GetMember (storey.Instance.Type, builder_field);
+ task_get = MemberCache.GetMember (builder_field.MemberType, task_get);
+ }
+
+ var pe_task = new PropertyExpr (storey.Task, loc) {
+ InstanceExpression = new FieldExpr (builder_field, loc) {
+ InstanceExpression = storey.Instance
+ },
+ Getter = task_get
+ };
+
+ pe_task.Emit (ec);
+ }
+
+ ec.Emit (OpCodes.Ret);
}
}
class AsyncTaskStorey : StateMachine
{
int awaiters;
- Field continuation;
-
- public AsyncTaskStorey (AsyncInitializer initializer)
- : base (initializer.Block, initializer.Host, null, null, "async")
+ Field builder, continuation;
+ readonly TypeSpec return_type;
+ MethodSpec set_result;
+ MethodSpec set_exception;
+ PropertySpec task;
+ LocalVariable hoisted_return;
+ int locals_captured;
+ Dictionary<TypeSpec, List<StackField>> stack_fields;
+ TypeSpec action;
+
+ public AsyncTaskStorey (IMemberContext context, AsyncInitializer initializer, TypeSpec type)
+ : base (initializer.OriginalBlock, initializer.Host, context.CurrentMemberDefinition as MemberBase, context.CurrentTypeParameters, "async")
{
+ return_type = type;
+ }
+
+ #region Properties
+
+ public Field Builder {
+ get {
+ return builder;
+ }
+ }
+
+ public LocalVariable HoistedReturn {
+ get {
+ return hoisted_return;
+ }
+ }
+
+ public TypeSpec ReturnType {
+ get {
+ return return_type;
+ }
+ }
+
+ public PropertySpec Task {
+ get {
+ return task;
+ }
}
+ #endregion
+
public Field AddAwaiter (TypeSpec type, Location loc)
{
- var field = AddCompilerGeneratedField ("$awaiter" + awaiters++.ToString ("X"), new TypeExpression (type, loc));
- return field;
+ return AddCapturedVariable ("$awaiter" + awaiters++.ToString ("X"), type);
}
- public Field Continuation {
- get {
- return continuation;
+ public StackField AddCapturedLocalVariable (TypeSpec type)
+ {
+ if (mutator != null)
+ type = mutator.Mutate (type);
+
+ List<StackField> existing_fields = null;
+ if (stack_fields == null) {
+ stack_fields = new Dictionary<TypeSpec, List<StackField>> ();
+ } else if (stack_fields.TryGetValue (type, out existing_fields)) {
+ foreach (var f in existing_fields) {
+ if (f.CanBeReused) {
+ f.CanBeReused = false;
+ return f;
+ }
+ }
}
+
+ const Modifiers mod = Modifiers.COMPILER_GENERATED | Modifiers.PRIVATE;
+ var field = new StackField (this, new TypeExpression (type, Location), mod, new MemberName ("<s>$" + locals_captured++.ToString ("X"), Location));
+ AddField (field);
+
+ field.Define ();
+
+ if (existing_fields == null) {
+ existing_fields = new List<StackField> ();
+ stack_fields.Add (type, existing_fields);
+ }
+
+ existing_fields.Add (field);
+
+ return field;
}
protected override bool DoDefineMembers ()
{
- var action = Module.PredefinedTypes.Action.Resolve ();
- if (action != null) {
- continuation = AddCompilerGeneratedField ("$continuation", new TypeExpression (action, Location));
- continuation.ModFlags |= Modifiers.READONLY;
+ action = Module.PredefinedTypes.Action.Resolve ();
+
+ PredefinedType builder_type;
+ PredefinedMember<MethodSpec> bf;
+ PredefinedMember<MethodSpec> sr;
+ PredefinedMember<MethodSpec> se;
+ bool has_task_return_type = false;
+ var pred_members = Module.PredefinedMembers;
+
+ if (return_type.Kind == MemberKind.Void) {
+ builder_type = Module.PredefinedTypes.AsyncVoidMethodBuilder;
+ bf = pred_members.AsyncVoidMethodBuilderCreate;
+ sr = pred_members.AsyncVoidMethodBuilderSetResult;
+ se = pred_members.AsyncVoidMethodBuilderSetException;
+ } else if (return_type == Module.PredefinedTypes.Task.TypeSpec) {
+ builder_type = Module.PredefinedTypes.AsyncTaskMethodBuilder;
+ bf = pred_members.AsyncTaskMethodBuilderCreate;
+ sr = pred_members.AsyncTaskMethodBuilderSetResult;
+ se = pred_members.AsyncTaskMethodBuilderSetException;
+ task = pred_members.AsyncTaskMethodBuilderTask.Get ();
+ } else {
+ builder_type = Module.PredefinedTypes.AsyncTaskMethodBuilderGeneric;
+ bf = pred_members.AsyncTaskMethodBuilderGenericCreate;
+ sr = pred_members.AsyncTaskMethodBuilderGenericSetResult;
+ se = pred_members.AsyncTaskMethodBuilderGenericSetException;
+ task = pred_members.AsyncTaskMethodBuilderGenericTask.Get ();
+ has_task_return_type = true;
+ }
+
+ set_result = sr.Get ();
+ set_exception = se.Get ();
+ var builder_factory = bf.Get ();
+ if (!builder_type.Define () || set_result == null || builder_factory == null || set_exception == null) {
+ Report.Error (1993, Location,
+ "Cannot find compiler required types for asynchronous functions support. Are you targeting the wrong framework version?");
+ return base.DoDefineMembers ();
}
+ var 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);
+ builder_factory = MemberCache.GetMember<MethodSpec> (bt, builder_factory);
+ set_result = MemberCache.GetMember<MethodSpec> (bt, set_result);
+ set_exception = MemberCache.GetMember<MethodSpec> (bt, set_exception);
+
+ if (task != null)
+ task = MemberCache.GetMember<PropertySpec> (bt, task);
+ }
+
+ builder = AddCompilerGeneratedField ("$builder", new TypeExpression (bt, Location));
+
+ var ctor = DefineDefaultConstructor (false);
+
if (!base.DoDefineMembers ())
return false;
+ Block block = ctor.Block;
+
+ var mg = MethodGroupExpr.CreatePredefined (builder_factory, bt, Location);
+ block.AddStatement (
+ new StatementExpression (new SimpleAssign (
+ new FieldExpr (builder, Location),
+ new Invocation (mg, new Arguments (0)),
+ Location)));
+
+ if (has_task_return_type) {
+ hoisted_return = LocalVariable.CreateCompilerGenerated (bt.TypeArguments[0], block, Location);
+ }
+
+ return true;
+ }
+
+ public Expression EmitContinuationInitialization (EmitContext ec)
+ {
//
- // Initialize continuation with state machine method
+ // When more than 1 awaiter has been used in the block we
+ // introduce class scope field to cache continuation delegate
//
- if (continuation != null) {
- var args = new Arguments (1);
- var mg = MethodGroupExpr.CreatePredefined (StateMachineMethod.Spec, spec, Location);
- args.Add (new Argument (mg));
+ if (awaiters > 1) {
+ if (continuation == null) {
+ continuation = AddCompilerGeneratedField ("$continuation", new TypeExpression (action, Location), true);
+ continuation.Define ();
+ }
- instance_constructors[0].Block.AddStatement (
- new StatementExpression (new SimpleAssign (
- new FieldExpr (continuation, Location),
- new NewDelegate (action, args, Location),
- Location
- )));
+ var fexpr = new FieldExpr (continuation, Location);
+ fexpr.InstanceExpression = new CompilerGeneratedThis (CurrentType, Location);
+
+ //
+ // if ($continuation == null)
+ // $continuation = new Action (MoveNext);
+ //
+ fexpr.Emit (ec);
+
+ var skip_cont_init = ec.DefineLabel ();
+ ec.Emit (OpCodes.Brtrue_S, skip_cont_init);
+
+ ec.EmitThis ();
+ EmitActionLoad (ec);
+ ec.Emit (OpCodes.Stfld, continuation.Spec);
+ ec.MarkLabel (skip_cont_init);
+
+ return fexpr;
}
- return true;
+ //
+ // Otherwise simply use temporary local variable
+ //
+ var field = LocalVariable.CreateCompilerGenerated (action, OriginalSourceBlock, Location);
+ EmitActionLoad (ec);
+ field.EmitAssign (ec);
+ return new LocalVariableReference (field, Location);
+ }
+
+ void EmitActionLoad (EmitContext ec)
+ {
+ ec.EmitThis ();
+ ec.Emit (OpCodes.Ldftn, StateMachineMethod.Spec);
+ ec.Emit (OpCodes.Newobj, (MethodSpec) MemberCache.FindMember (action, MemberFilter.Constructor (null), BindingRestriction.DeclaredOnly));
+ }
+
+ public void EmitSetException (EmitContext ec, LocalVariableReference exceptionVariable)
+ {
+ //
+ // $builder.SetException (Exception)
+ //
+ var mg = MethodGroupExpr.CreatePredefined (set_exception, set_exception.DeclaringType, Location);
+ mg.InstanceExpression = new FieldExpr (Builder, Location) {
+ InstanceExpression = new CompilerGeneratedThis (ec.CurrentType, Location)
+ };
+
+ Arguments args = new Arguments (1);
+ args.Add (new Argument (exceptionVariable));
+
+ mg.EmitCall (ec, args);
+ }
+
+ public void EmitSetResult (EmitContext ec)
+ {
+ //
+ // $builder.SetResult ();
+ // $builder.SetResult<return-type> (value);
+ //
+ var mg = MethodGroupExpr.CreatePredefined (set_result, set_result.DeclaringType, Location);
+ mg.InstanceExpression = new FieldExpr (Builder, Location) {
+ InstanceExpression = new CompilerGeneratedThis (ec.CurrentType, Location)
+ };
+
+ Arguments args;
+ if (hoisted_return == null) {
+ args = new Arguments (0);
+ } else {
+ args = new Arguments (1);
+ args.Add (new Argument (new LocalVariableReference (hoisted_return, Location)));
+ }
+
+ mg.EmitCall (ec, args);
+ }
+ }
+
+ class StackField : Field
+ {
+ public StackField (TypeDefinition parent, FullNamedExpression type, Modifiers mod, MemberName name)
+ : base (parent, type, mod, name, null)
+ {
+ }
+
+ public bool CanBeReused { get; set; }
+ }
+
+ class StackFieldExpr : FieldExpr
+ {
+ public StackFieldExpr (Field field)
+ : base (field, Location.Null)
+ {
+ }
+
+ public override void Emit (EmitContext ec)
+ {
+ base.Emit (ec);
+
+ var field = (StackField) spec.MemberDefinition;
+ field.CanBeReused = true;
}
}
}
projects / mono.git / blobdiff