Implement optimization where lambdas can be replaced by direct method-group they...
[mono.git] / mcs / mcs / anonymous.cs
index 0b7a645c46140a6ff2aa97c978754c8d0fd0f954..fe16344ae0dccfeac67792434e9433441d1ded99 100644 (file)
@@ -815,7 +815,7 @@ namespace Mono.CSharp {
                sealed class HoistedFieldAssign : CompilerAssign
                {
                        public HoistedFieldAssign (Expression target, Expression source)
-                               : base (target, source, source.Location)
+                               : base (target, source, target.Location)
                        {
                        }
 
@@ -1095,9 +1095,19 @@ namespace Mono.CSharp {
                        if (d_params.Count != Parameters.Count)
                                return false;
 
+                       var ptypes = Parameters.Types;
+                       var dtypes = d_params.Types;
                        for (int i = 0; i < Parameters.Count; ++i) {
-                               if (type_inference.ExactInference (Parameters.Types[i], d_params.Types[i]) == 0)
+                               if (type_inference.ExactInference (ptypes[i], dtypes[i]) == 0) {
+                                       //
+                                       // Continue when 0 (quick path) does not mean inference failure. Checking for
+                                       // same type handles cases like int -> int
+                                       //
+                                       if (ptypes[i] == dtypes[i])
+                                               continue;
+
                                        return false;
+                               }
                        }
 
                        return true;
@@ -1214,6 +1224,17 @@ namespace Mono.CSharp {
                                        }
                                } else {
                                        am = body.Compatible (ec);
+
+                                       if (body.DirectMethodGroupConversion != null) {
+                                               var errors_printer = new SessionReportPrinter ();
+                                               var old = ec.Report.SetPrinter (errors_printer);
+                                               var expr = new ImplicitDelegateCreation (delegate_type, body.DirectMethodGroupConversion, loc) {
+                                                       AllowSpecialMethodsInvocation = true
+                                               }.Resolve (ec);
+                                               ec.Report.SetPrinter (old);
+                                               if (expr != null && errors_printer.ErrorsCount == 0)
+                                                       am = expr;
+                                       }
                                }
                        } catch (CompletionResult) {
                                throw;
@@ -1352,7 +1373,7 @@ namespace Mono.CSharp {
                                b = b.ConvertToAsyncTask (ec, ec.CurrentMemberDefinition.Parent.PartialContainer, p, return_type, loc);
                        }
 
-                       return CompatibleMethodFactory (return_type ?? InternalType.Arglist, delegate_type, p, b);
+                       return CompatibleMethodFactory (return_type ?? InternalType.ErrorType, delegate_type, p, b);
                }
 
                protected virtual AnonymousMethodBody CompatibleMethodFactory (TypeSpec return_type, TypeSpec delegate_type, ParametersCompiled p, ParametersBlock b)
@@ -1437,7 +1458,7 @@ namespace Mono.CSharp {
                        }
                }
 
-               protected ParametersBlock block;
+               protected readonly ParametersBlock block;
 
                public TypeSpec ReturnType;
 
@@ -1475,27 +1496,15 @@ namespace Mono.CSharp {
                        BlockContext aec = new BlockContext (ec, block, ReturnType);
                        aec.CurrentAnonymousMethod = ae;
 
-                       ResolveContext.Options flags = 0;
-
                        var am = this as AnonymousMethodBody;
 
                        if (ec.HasSet (ResolveContext.Options.InferReturnType) && am != null) {
                                am.ReturnTypeInference = new TypeInferenceContext ();
                        }
 
-                       if (ec.IsInProbingMode)
-                               flags |= ResolveContext.Options.ProbingMode;
-
-                       if (ec.HasSet (ResolveContext.Options.FieldInitializerScope))
-                               flags |= ResolveContext.Options.FieldInitializerScope;
-
-                       if (ec.HasSet (ResolveContext.Options.ExpressionTreeConversion))
-                               flags |= ResolveContext.Options.ExpressionTreeConversion;
-
-                       if (ec.HasSet (ResolveContext.Options.BaseInitializer))
-                               flags |= ResolveContext.Options.BaseInitializer;
-
-                       aec.Set (flags);
+                       var bc = ec as BlockContext;
+                       if (bc != null)
+                               aec.FlowOffset = bc.FlowOffset;
 
                        var errors = ec.Report.Errors;
 
@@ -1564,6 +1573,14 @@ namespace Mono.CSharp {
                        get { return "anonymous method"; }
                }
 
+               //
+               // Method-group instance for lambdas which can be replaced with
+               // simple method group call
+               //
+               public MethodGroupExpr DirectMethodGroupConversion {
+                       get; set;
+               }
+
                public override bool IsIterator {
                        get {
                                return false;
@@ -1586,7 +1603,9 @@ namespace Mono.CSharp {
                }
 
                public override AnonymousMethodStorey Storey {
-                       get { return storey; }
+                       get {
+                               return storey;
+                       }
                }
 
                #endregion
@@ -1631,21 +1650,25 @@ namespace Mono.CSharp {
                                parent = storey = FindBestMethodStorey ();
 
                                if (storey == null) {
-                                       var sm = src_block.ParametersBlock.TopBlock.StateMachine;
+                                       var top_block = src_block.ParametersBlock.TopBlock;
+                                       var sm = top_block.StateMachine;
 
-                                       //
-                                       // Remove hoisted this demand when simple instance method is enough
-                                       //
                                        if (src_block.HasCapturedThis) {
-                                               src_block.ParametersBlock.TopBlock.RemoveThisReferenceFromChildrenBlock (src_block);
+                                               //
+                                               // Remove hoisted 'this' request when simple instance method is
+                                               // enough (no hoisted variables only 'this')
+                                               //
+                                               if (src_block.ParametersBlock.StateMachine == null)
+                                                       top_block.RemoveThisReferenceFromChildrenBlock (src_block);
 
                                                //
                                                // Special case where parent class is used to emit instance method
-                                               // because currect storey is of value type (async host) and we don't
-                                               // want to create another childer storey to host this reference only
+                                               // because currect storey is of value type (async host). We cannot
+                                               // use ldftn on non-boxed instances either to share mutated state
                                                //
-                                               if (sm != null && sm.Kind == MemberKind.Struct)
+                                               if (sm != null && sm.Kind == MemberKind.Struct) {
                                                        parent = sm.Parent.PartialContainer;
+                                               }
                                        }
 
                                        //
@@ -2007,11 +2030,11 @@ namespace Mono.CSharp {
 
                                IntConstant FNV_prime = new IntConstant (Compiler.BuiltinTypes, 16777619, loc);                         
                                rs_hashcode = new Binary (Binary.Operator.Multiply,
-                                       new Binary (Binary.Operator.ExclusiveOr, rs_hashcode, field_hashcode, loc),
-                                       FNV_prime, loc);
+                                       new Binary (Binary.Operator.ExclusiveOr, rs_hashcode, field_hashcode),
+                                       FNV_prime);
 
                                Expression field_to_string = new Conditional (new BooleanExpression (new Binary (Binary.Operator.Inequality,
-                                       new MemberAccess (new This (f.Location), f.Name), new NullLiteral (loc), loc)),
+                                       new MemberAccess (new This (f.Location), f.Name), new NullLiteral (loc))),
                                        new Invocation (new MemberAccess (
                                                new MemberAccess (new This (f.Location), f.Name), "ToString"), null),
                                        new StringConstant (Compiler.BuiltinTypes, string.Empty, loc), loc);
@@ -2022,9 +2045,7 @@ namespace Mono.CSharp {
                                                string_concat,
                                                new Binary (Binary.Operator.Addition,
                                                        new StringConstant (Compiler.BuiltinTypes, " " + p.Name + " = ", loc),
-                                                       field_to_string,
-                                                       loc),
-                                               loc);
+                                                       field_to_string));
                                        continue;
                                }
 
@@ -2034,18 +2055,15 @@ namespace Mono.CSharp {
                                string_concat = new Binary (Binary.Operator.Addition,
                                        new Binary (Binary.Operator.Addition,
                                                string_concat,
-                                               new StringConstant (Compiler.BuiltinTypes, ", " + p.Name + " = ", loc),
-                                               loc),
-                                       field_to_string,
-                                       loc);
+                                               new StringConstant (Compiler.BuiltinTypes, ", " + p.Name + " = ", loc)),
+                                       field_to_string);
 
-                               rs_equals = new Binary (Binary.Operator.LogicalAnd, rs_equals, field_equal, loc);
+                               rs_equals = new Binary (Binary.Operator.LogicalAnd, rs_equals, field_equal);
                        }
 
                        string_concat = new Binary (Binary.Operator.Addition,
                                string_concat,
-                               new StringConstant (Compiler.BuiltinTypes, " }", loc),
-                               loc);
+                               new StringConstant (Compiler.BuiltinTypes, " }", loc));
 
                        //
                        // Equals (object obj) override
@@ -2056,9 +2074,9 @@ namespace Mono.CSharp {
                                        new As (equals_block.GetParameterReference (0, loc),
                                                current_type, loc), loc)));
 
-                       Expression equals_test = new Binary (Binary.Operator.Inequality, other_variable, new NullLiteral (loc), loc);
+                       Expression equals_test = new Binary (Binary.Operator.Inequality, other_variable, new NullLiteral (loc));
                        if (rs_equals != null)
-                               equals_test = new Binary (Binary.Operator.LogicalAnd, equals_test, rs_equals, loc);
+                               equals_test = new Binary (Binary.Operator.LogicalAnd, equals_test, rs_equals);
                        equals_block.AddStatement (new Return (equals_test, loc));
 
                        equals.Block = equals_block;
@@ -2100,19 +2118,19 @@ namespace Mono.CSharp {
                        var hash_variable = new LocalVariableReference (li_hash, loc);
                        hashcode_block.AddStatement (new StatementExpression (
                                new CompoundAssign (Binary.Operator.Addition, hash_variable,
-                                       new Binary (Binary.Operator.LeftShift, hash_variable, new IntConstant (Compiler.BuiltinTypes, 13, loc), loc), loc)));
+                                       new Binary (Binary.Operator.LeftShift, hash_variable, new IntConstant (Compiler.BuiltinTypes, 13, loc)))));
                        hashcode_block.AddStatement (new StatementExpression (
                                new CompoundAssign (Binary.Operator.ExclusiveOr, hash_variable,
-                                       new Binary (Binary.Operator.RightShift, hash_variable, new IntConstant (Compiler.BuiltinTypes, 7, loc), loc), loc)));
+                                       new Binary (Binary.Operator.RightShift, hash_variable, new IntConstant (Compiler.BuiltinTypes, 7, loc)))));
                        hashcode_block.AddStatement (new StatementExpression (
                                new CompoundAssign (Binary.Operator.Addition, hash_variable,
-                                       new Binary (Binary.Operator.LeftShift, hash_variable, new IntConstant (Compiler.BuiltinTypes, 3, loc), loc), loc)));
+                                       new Binary (Binary.Operator.LeftShift, hash_variable, new IntConstant (Compiler.BuiltinTypes, 3, loc)))));
                        hashcode_block.AddStatement (new StatementExpression (
                                new CompoundAssign (Binary.Operator.ExclusiveOr, hash_variable,
-                                       new Binary (Binary.Operator.RightShift, hash_variable, new IntConstant (Compiler.BuiltinTypes, 17, loc), loc), loc)));
+                                       new Binary (Binary.Operator.RightShift, hash_variable, new IntConstant (Compiler.BuiltinTypes, 17, loc)))));
                        hashcode_block.AddStatement (new StatementExpression (
                                new CompoundAssign (Binary.Operator.Addition, hash_variable,
-                                       new Binary (Binary.Operator.LeftShift, hash_variable, new IntConstant (Compiler.BuiltinTypes, 5, loc), loc), loc)));
+                                       new Binary (Binary.Operator.LeftShift, hash_variable, new IntConstant (Compiler.BuiltinTypes, 5, loc)))));
 
                        hashcode_block.AddStatement (new Return (hash_variable, loc));
                        hashcode.Block = hashcode_top;