private void VisitCall( MethodSymbol method, PropertySymbol propertyAccess, ImmutableArray <BoundExpression> arguments, ImmutableArray <RefKind> argumentRefKindsOpt, ImmutableArray <string> argumentNamesOpt, bool expanded, BoundNode node) { Debug.Assert((object)method != null); Debug.Assert(((object)propertyAccess == null) || (method == propertyAccess.GetOwnOrInheritedGetMethod()) || (method == propertyAccess.GetOwnOrInheritedSetMethod()) || propertyAccess.MustCallMethodsDirectly); CheckArguments(argumentRefKindsOpt, arguments, method); if (_inExpressionLambda) { if (method.CallsAreOmitted(node.SyntaxTree)) { Error(ErrorCode.ERR_PartialMethodInExpressionTree, node); } else if ((object)propertyAccess != null && propertyAccess.IsIndexedProperty() && !propertyAccess.IsIndexer) { Error(ErrorCode.ERR_ExpressionTreeContainsIndexedProperty, node); } else if (arguments.Length < (((object)propertyAccess != null) ? propertyAccess.ParameterCount : method.ParameterCount) + (expanded ? -1 : 0)) { Error(ErrorCode.ERR_ExpressionTreeContainsOptionalArgument, node); } else if (!argumentNamesOpt.IsDefaultOrEmpty) { Error(ErrorCode.ERR_ExpressionTreeContainsNamedArgument, node); } else if (IsComCallWithRefOmitted(method, arguments, argumentRefKindsOpt)) { Error(ErrorCode.ERR_ComRefCallInExpressionTree, node); } else if (method.MethodKind == MethodKind.LocalFunction) { Error(ErrorCode.ERR_ExpressionTreeContainsLocalFunction, node); } else if (method.RefKind != RefKind.None) { Error(ErrorCode.ERR_RefReturningCallInExpressionTree, node); } } }
private BoundExpression MakeIndexerAccess( CSharpSyntaxNode syntax, BoundExpression rewrittenReceiver, PropertySymbol indexer, ImmutableArray <BoundExpression> rewrittenArguments, ImmutableArray <string> argumentNamesOpt, ImmutableArray <RefKind> argumentRefKindsOpt, bool expanded, ImmutableArray <int> argsToParamsOpt, TypeSymbol type, BoundIndexerAccess oldNodeOpt, bool isLeftOfAssignment) { if (isLeftOfAssignment) { // This is an indexer set access. We return a BoundIndexerAccess node here. // This node will be rewritten with MakePropertyAssignment when rewriting the enclosing BoundAssignmentOperator. return(oldNodeOpt != null? oldNodeOpt.Update(rewrittenReceiver, indexer, rewrittenArguments, argumentNamesOpt, argumentRefKindsOpt, expanded, argsToParamsOpt, type) : new BoundIndexerAccess(syntax, rewrittenReceiver, indexer, rewrittenArguments, argumentNamesOpt, argumentRefKindsOpt, expanded, argsToParamsOpt, type)); } else { var getMethod = indexer.GetOwnOrInheritedGetMethod(); Debug.Assert((object)getMethod != null); // We have already lowered each argument, but we may need some additional rewriting for the arguments, // such as generating a params array, re-ordering arguments based on argsToParamsOpt map, inserting arguments for optional parameters, etc. ImmutableArray <LocalSymbol> temps; rewrittenArguments = MakeArguments(syntax, rewrittenArguments, indexer, getMethod, expanded, argsToParamsOpt, ref argumentRefKindsOpt, out temps, enableCallerInfo: ThreeState.True); BoundExpression call = MakePropertyGetAccess(syntax, rewrittenReceiver, indexer, rewrittenArguments, getMethod); if (temps.IsDefaultOrEmpty) { return(call); } else { return(new BoundSequence( syntax, temps, ImmutableArray <BoundExpression> .Empty, call, type)); } } }
private void VisitCall( MethodSymbol method, PropertySymbol propertyAccess, ImmutableArray <BoundExpression> arguments, ImmutableArray <RefKind> argumentRefKindsOpt, ImmutableArray <string> argumentNamesOpt, bool expanded, BoundNode node) { Debug.Assert((object)method != null); Debug.Assert(((object)propertyAccess == null) || (method == propertyAccess.GetOwnOrInheritedGetMethod()) || (method == propertyAccess.GetOwnOrInheritedSetMethod()) || propertyAccess.MustCallMethodsDirectly); CheckArguments(argumentRefKindsOpt, arguments, method); }
private BoundExpression MakePropertyGetAccess( SyntaxNode syntax, BoundExpression rewrittenReceiver, PropertySymbol property, ImmutableArray <BoundExpression> rewrittenArguments, MethodSymbol getMethodOpt = null, BoundPropertyAccess oldNodeOpt = null) { var getMethod = getMethodOpt ?? property.GetOwnOrInheritedGetMethod(); Debug.Assert((object)getMethod != null); Debug.Assert(getMethod.ParameterCount == rewrittenArguments.Length); Debug.Assert(((object)getMethodOpt == null) || ReferenceEquals(getMethod, getMethodOpt)); return(BoundCall.Synthesized( syntax, rewrittenReceiver, getMethod, rewrittenArguments)); }
private BoundExpression MakePropertyGetAccess( SyntaxNode syntax, BoundExpression rewrittenReceiver, PropertySymbol property, ImmutableArray <BoundExpression> rewrittenArguments, MethodSymbol getMethodOpt = null, BoundPropertyAccess oldNodeOpt = null) { #if XSHARP if (property is XsVariableSymbol xsvar) { return(MemVarFieldAccess(syntax, xsvar)); } #endif if (_inExpressionLambda && rewrittenArguments.IsEmpty) { return(oldNodeOpt != null? oldNodeOpt.Update(rewrittenReceiver, property, LookupResultKind.Viable, property.Type) : new BoundPropertyAccess(syntax, rewrittenReceiver, property, LookupResultKind.Viable, property.Type)); } else { var getMethod = getMethodOpt ?? property.GetOwnOrInheritedGetMethod(); #if !XSHARP Debug.Assert((object)getMethod != null); Debug.Assert(getMethod.ParameterCount == rewrittenArguments.Length); Debug.Assert(((object)getMethodOpt == null) || ReferenceEquals(getMethod, getMethodOpt)); #else if (getMethod == null) { _diagnostics.Add(new CSDiagnosticInfo(ErrorCode.ERR_PropertyLacksGet, property.Name), syntax.Location); return(BadExpression(rewrittenReceiver)); } #endif return(BoundCall.Synthesized( syntax, rewrittenReceiver, getMethod, rewrittenArguments)); } }
private BoundIndexerAccess TransformIndexerAccess(BoundIndexerAccess indexerAccess, ArrayBuilder <BoundExpression> stores, ArrayBuilder <LocalSymbol> temps) { var receiverOpt = indexerAccess.ReceiverOpt; Debug.Assert(receiverOpt != null); BoundExpression transformedReceiver; if (CanChangeValueBetweenReads(receiverOpt)) { BoundExpression rewrittenReceiver = VisitExpression(receiverOpt); BoundAssignmentOperator assignmentToTemp; // SPEC VIOLATION: It is not very clear when receiver of constrained callvirt is dereferenced - when pushed (in lexical order), // SPEC VIOLATION: or when actual call is executed. The actual behavior seems to be implementation specific in different JITs. // SPEC VIOLATION: To not depend on that, the right thing to do here is to store the value of the variable // SPEC VIOLATION: when variable has reference type (regular temp), and store variable's location when it has a value type. (ref temp) // SPEC VIOLATION: in a case of unconstrained generic type parameter a runtime test (default(T) == null) would be needed // SPEC VIOLATION: However, for compatibility with Dev12 we will continue treating all generic type parameters, constrained or not, // SPEC VIOLATION: as value types. var variableRepresentsLocation = rewrittenReceiver.Type.IsValueType || rewrittenReceiver.Type.Kind == SymbolKind.TypeParameter; var receiverTemp = _factory.StoreToTemp(rewrittenReceiver, out assignmentToTemp, refKind: variableRepresentsLocation ? RefKind.Ref : RefKind.None); transformedReceiver = receiverTemp; stores.Add(assignmentToTemp); temps.Add(receiverTemp.LocalSymbol); } else { transformedReceiver = VisitExpression(receiverOpt); } // Dealing with the arguments is a bit tricky because they can be named out-of-order arguments; // we have to preserve both the source-code order of the side effects and the side effects // only being executed once. // // This is a subtly different problem than the problem faced by the conventional call // rewriter; with the conventional call rewriter we already know that the side effects // will only be executed once because the arguments are only being pushed on the stack once. // In a compound equality operator on an indexer the indices are placed on the stack twice. // That is to say, if you have: // // C().M(z : Z(), x : X(), y : Y()) // // then we can rewrite that into // // tempc = C() // tempz = Z() // tempc.M(X(), Y(), tempz) // // See, we can optimize away two of the temporaries, for x and y. But we cannot optimize away any of the // temporaries in // // C().Collection[z : Z(), x : X(), y : Y()] += 1; // // because we have to ensure not just that Z() happens first, but in addition that X() and Y() are only // called once. We have to generate this as // // tempc = C().Collection // tempz = Z() // tempx = X() // tempy = Y() // tempc[tempx, tempy, tempz] = tempc[tempx, tempy, tempz] + 1; // // Fortunately arguments to indexers are never ref or out, so we don't need to worry about that. // However, we can still do the optimization where constants are not stored in // temporaries; if we have // // C().Collection[z : 123, y : Y(), x : X()] += 1; // // Then we can generate that as // // tempc = C().Collection // tempx = X() // tempy = Y() // tempc[tempx, tempy, 123] = tempc[tempx, tempy, 123] + 1; ImmutableArray <BoundExpression> rewrittenArguments = VisitList(indexerAccess.Arguments); SyntaxNode syntax = indexerAccess.Syntax; PropertySymbol indexer = indexerAccess.Indexer; ImmutableArray <RefKind> argumentRefKinds = indexerAccess.ArgumentRefKindsOpt; bool expanded = indexerAccess.Expanded; ImmutableArray <int> argsToParamsOpt = indexerAccess.ArgsToParamsOpt; ImmutableArray <ParameterSymbol> parameters = indexer.Parameters; BoundExpression[] actualArguments = new BoundExpression[parameters.Length]; // The actual arguments that will be passed; one actual argument per formal parameter. ArrayBuilder <BoundAssignmentOperator> storesToTemps = ArrayBuilder <BoundAssignmentOperator> .GetInstance(rewrittenArguments.Length); ArrayBuilder <RefKind> refKinds = ArrayBuilder <RefKind> .GetInstance(parameters.Length, RefKind.None); // Step one: Store everything that is non-trivial into a temporary; record the // stores in storesToTemps and make the actual argument a reference to the temp. // Do not yet attempt to deal with params arrays or optional arguments. BuildStoresToTemps(expanded, argsToParamsOpt, argumentRefKinds, rewrittenArguments, actualArguments, refKinds, storesToTemps); // Step two: If we have a params array, build the array and fill in the argument. if (expanded) { BoundExpression array = BuildParamsArray(syntax, indexer, argsToParamsOpt, rewrittenArguments, parameters, actualArguments[actualArguments.Length - 1]); BoundAssignmentOperator storeToTemp; var boundTemp = _factory.StoreToTemp(array, out storeToTemp); stores.Add(storeToTemp); temps.Add(boundTemp.LocalSymbol); actualArguments[actualArguments.Length - 1] = boundTemp; } // Step three: Now fill in the optional arguments. (Dev11 uses the getter for optional arguments in // compound assignments, but for deconstructions we use the setter if the getter is missing.) var accessor = indexer.GetOwnOrInheritedGetMethod() ?? indexer.GetOwnOrInheritedSetMethod(); InsertMissingOptionalArguments(syntax, accessor.Parameters, actualArguments); // For a call, step four would be to optimize away some of the temps. However, we need them all to prevent // duplicate side-effects, so we'll skip that step. if (indexer.ContainingType.IsComImport) { RewriteArgumentsForComCall(parameters, actualArguments, refKinds, temps); } rewrittenArguments = actualArguments.AsImmutableOrNull(); foreach (BoundAssignmentOperator tempAssignment in storesToTemps) { temps.Add(((BoundLocal)tempAssignment.Left).LocalSymbol); stores.Add(tempAssignment); } storesToTemps.Free(); argumentRefKinds = GetRefKindsOrNull(refKinds); refKinds.Free(); // This is a temporary object that will be rewritten away before the lowering completes. return(new BoundIndexerAccess( syntax, transformedReceiver, indexer, rewrittenArguments, default(ImmutableArray <string>), argumentRefKinds, false, default(ImmutableArray <int>), null, indexerAccess.UseSetterForDefaultArgumentGeneration, indexerAccess.Type)); }
/// <summary> /// In the expanded form of a compound assignment (or increment/decrement), the LHS appears multiple times. /// If we aren't careful, this can result in repeated side-effects. This creates (ordered) temps for all of the /// subexpressions that could result in side-effects and returns a side-effect-free expression that can be used /// in place of the LHS in the expanded form. /// </summary> /// <param name="originalLHS">The LHS sub-expression of the compound assignment (or increment/decrement).</param> /// <param name="stores">Populated with a list of assignment expressions that initialize the temporary locals.</param> /// <param name="temps">Populated with a list of temporary local symbols.</param> /// <param name="isDynamicAssignment">True if the compound assignment is a dynamic operation.</param> /// <returns> /// A side-effect-free expression representing the LHS. /// The returned node needs to be lowered but its children are already lowered. /// </returns> private BoundExpression TransformCompoundAssignmentLHS(BoundExpression originalLHS, ArrayBuilder <BoundExpression> stores, ArrayBuilder <LocalSymbol> temps, bool isDynamicAssignment) { // There are five possible cases. // // Case 1: receiver.Prop += value is transformed into // temp = receiver // temp.Prop = temp.Prop + value // and a later rewriting will turn that into calls to getters and setters. // // Case 2: collection[i1, i2, i3] += value is transformed into // tc = collection // t1 = i1 // t2 = i2 // t3 = i3 // tc[t1, t2, t3] = tc[t1, t2, t3] + value // and again, a later rewriting will turn that into getters and setters of the indexer. // // Case 3: local += value (and param += value) needs no temporaries; it simply // becomes local = local + value. // // Case 4: staticField += value needs no temporaries either. However, classInst.field += value becomes // temp = classInst // temp.field = temp.field + value // // Case 5: otherwise, it must be structVariable.field += value or array[index] += value. Either way // we have a variable on the left. Transform it into: // ref temp = ref variable // temp = temp + value switch (originalLHS.Kind) { case BoundKind.PropertyAccess: { // We need to stash away the receiver so that it does not get evaluated twice. // If the receiver is classified as a value of reference type then we can simply say // // R temp = receiver // temp.prop = temp.prop + rhs // // But if the receiver is classified as a variable of struct type then we // cannot make a copy of the value; we need to make sure that we mutate // the original receiver, not the copy. We have to generate // // ref R temp = ref receiver // temp.prop = temp.prop + rhs // // The rules of C# (in section 7.17.1) require that if you have receiver.prop // as the target of an assignment such that receiver is a value type, it must // be classified as a variable. If we've gotten this far in the rewriting, // assume that was the case. var prop = (BoundPropertyAccess)originalLHS; // If the property is static or if the receiver is of kind "Base" or "this", then we can just generate prop = prop + value if (prop.ReceiverOpt == null || prop.PropertySymbol.IsStatic || !IntroducingReadCanBeObservable(prop.ReceiverOpt)) { return(prop); } Debug.Assert(prop.ReceiverOpt.Kind != BoundKind.TypeExpression); BoundExpression rewrittenReceiver = VisitExpression(prop.ReceiverOpt); BoundAssignmentOperator assignmentToTemp; // SPEC VIOLATION: It is not very clear when receiver of constrained callvirt is dereferenced - when pushed (in lexical order), // SPEC VIOLATION: or when actual call is executed. The actual behavior seems to be implementation specific in different JITs. // SPEC VIOLATION: To not depend on that, the right thing to do here is to store the value of the variable // SPEC VIOLATION: when variable has reference type (regular temp), and store variable's location when it has a value type. (ref temp) // SPEC VIOLATION: in a case of unconstrained generic type parameter a runtime test (default(T) == null) would be needed // SPEC VIOLATION: However, for compatibility with Dev12 we will continue treating all generic type parameters, constrained or not, // SPEC VIOLATION: as value types. var variableRepresentsLocation = rewrittenReceiver.Type.IsValueType || rewrittenReceiver.Type.Kind == SymbolKind.TypeParameter; var receiverTemp = _factory.StoreToTemp(rewrittenReceiver, out assignmentToTemp, refKind: variableRepresentsLocation ? RefKind.Ref : RefKind.None); stores.Add(assignmentToTemp); temps.Add(receiverTemp.LocalSymbol); // CONSIDER: this is a temporary object that will be rewritten away before this lowering completes. // Mitigation: this will only produce short-lived garbage for compound assignments and increments/decrements of properties. return(new BoundPropertyAccess(prop.Syntax, receiverTemp, prop.PropertySymbol, prop.ResultKind, prop.Type)); } case BoundKind.DynamicMemberAccess: { var memberAccess = (BoundDynamicMemberAccess)originalLHS; if (!IntroducingReadCanBeObservable(memberAccess.Receiver)) { return(memberAccess); } // store receiver to temp: var rewrittenReceiver = VisitExpression(memberAccess.Receiver); BoundAssignmentOperator assignmentToTemp; var receiverTemp = _factory.StoreToTemp(rewrittenReceiver, out assignmentToTemp); stores.Add(assignmentToTemp); temps.Add(receiverTemp.LocalSymbol); return(new BoundDynamicMemberAccess(memberAccess.Syntax, receiverTemp, memberAccess.TypeArgumentsOpt, memberAccess.Name, memberAccess.Invoked, memberAccess.Indexed, memberAccess.Type)); } case BoundKind.IndexerAccess: { BoundIndexerAccess indexerAccess = (BoundIndexerAccess)originalLHS; var receiverOpt = indexerAccess.ReceiverOpt; Debug.Assert(receiverOpt != null); BoundExpression transformedReceiver; if (IntroducingReadCanBeObservable(receiverOpt)) { BoundExpression rewrittenReceiver = VisitExpression(receiverOpt); BoundAssignmentOperator assignmentToTemp; // SPEC VIOLATION: It is not very clear when receiver of constrained callvirt is dereferenced - when pushed (in lexical order), // SPEC VIOLATION: or when actual call is executed. The actual behavior seems to be implementation specific in different JITs. // SPEC VIOLATION: To not depend on that, the right thing to do here is to store the value of the variable // SPEC VIOLATION: when variable has reference type (regular temp), and store variable's location when it has a value type. (ref temp) // SPEC VIOLATION: in a case of unconstrained generic type parameter a runtime test (default(T) == null) would be needed // SPEC VIOLATION: However, for compatibility with Dev12 we will continue treating all generic type parameters, constrained or not, // SPEC VIOLATION: as value types. var variableRepresentsLocation = rewrittenReceiver.Type.IsValueType || rewrittenReceiver.Type.Kind == SymbolKind.TypeParameter; var receiverTemp = _factory.StoreToTemp(rewrittenReceiver, out assignmentToTemp, refKind: variableRepresentsLocation ? RefKind.Ref : RefKind.None); transformedReceiver = receiverTemp; stores.Add(assignmentToTemp); temps.Add(receiverTemp.LocalSymbol); } else { transformedReceiver = VisitExpression(receiverOpt); } // Dealing with the arguments is a bit tricky because they can be named out-of-order arguments; // we have to preserve both the source-code order of the side effects and the side effects // only being executed once. // // This is a subtly different problem than the problem faced by the conventional call // rewriter; with the conventional call rewriter we already know that the side effects // will only be executed once because the arguments are only being pushed on the stack once. // In a compound equality operator on an indexer the indices are placed on the stack twice. // That is to say, if you have: // // C().M(z : Z(), x : X(), y : Y()) // // then we can rewrite that into // // tempc = C() // tempz = Z() // tempc.M(X(), Y(), tempz) // // See, we can optimize away two of the temporaries, for x and y. But we cannot optimize away any of the // temporaries in // // C().Collection[z : Z(), x : X(), y : Y()] += 1; // // because we have to ensure not just that Z() happens first, but in addition that X() and Y() are only // called once. We have to generate this as // // tempc = C().Collection // tempz = Z() // tempx = X() // tempy = Y() // tempc[tempx, tempy, tempz] = tempc[tempx, tempy, tempz] + 1; // // Fortunately arguments to indexers are never ref or out, so we don't need to worry about that. // However, we can still do the optimization where constants are not stored in // temporaries; if we have // // C().Collection[z : 123, y : Y(), x : X()] += 1; // // Then we can generate that as // // tempc = C().Collection // tempx = X() // tempy = Y() // tempc[tempx, tempy, 123] = tempc[tempx, tempy, 123] + 1; ImmutableArray <BoundExpression> rewrittenArguments = VisitList(indexerAccess.Arguments); CSharpSyntaxNode syntax = indexerAccess.Syntax; PropertySymbol indexer = indexerAccess.Indexer; ImmutableArray <RefKind> argumentRefKinds = indexerAccess.ArgumentRefKindsOpt; bool expanded = indexerAccess.Expanded; ImmutableArray <int> argsToParamsOpt = indexerAccess.ArgsToParamsOpt; ImmutableArray <ParameterSymbol> parameters = indexer.Parameters; BoundExpression[] actualArguments = new BoundExpression[parameters.Length]; // The actual arguments that will be passed; one actual argument per formal parameter. ArrayBuilder <BoundAssignmentOperator> storesToTemps = ArrayBuilder <BoundAssignmentOperator> .GetInstance(rewrittenArguments.Length); ArrayBuilder <RefKind> refKinds = ArrayBuilder <RefKind> .GetInstance(parameters.Length, RefKind.None); // Step one: Store everything that is non-trivial into a temporary; record the // stores in storesToTemps and make the actual argument a reference to the temp. // Do not yet attempt to deal with params arrays or optional arguments. BuildStoresToTemps(expanded, argsToParamsOpt, argumentRefKinds, rewrittenArguments, actualArguments, refKinds, storesToTemps); // Step two: If we have a params array, build the array and fill in the argument. if (expanded) { BoundExpression array = BuildParamsArray(syntax, indexer, argsToParamsOpt, rewrittenArguments, parameters, actualArguments[actualArguments.Length - 1]); BoundAssignmentOperator storeToTemp; var boundTemp = _factory.StoreToTemp(array, out storeToTemp); stores.Add(storeToTemp); temps.Add(boundTemp.LocalSymbol); actualArguments[actualArguments.Length - 1] = boundTemp; } // Step three: Now fill in the optional arguments. (Dev11 uses the // getter for optional arguments in compound assignments.) var getMethod = indexer.GetOwnOrInheritedGetMethod(); Debug.Assert((object)getMethod != null); InsertMissingOptionalArguments(syntax, getMethod.Parameters, actualArguments); // For a call, step four would be to optimize away some of the temps. However, we need them all to prevent // duplicate side-effects, so we'll skip that step. if (indexer.ContainingType.IsComImport) { RewriteArgumentsForComCall(parameters, actualArguments, refKinds, temps); } rewrittenArguments = actualArguments.AsImmutableOrNull(); foreach (BoundAssignmentOperator tempAssignment in storesToTemps) { temps.Add(((BoundLocal)tempAssignment.Left).LocalSymbol); stores.Add(tempAssignment); } storesToTemps.Free(); argumentRefKinds = GetRefKindsOrNull(refKinds); refKinds.Free(); // CONSIDER: this is a temporary object that will be rewritten away before this lowering completes. // Mitigation: this will only produce short-lived garbage for compound assignments and increments/decrements of indexers. return(new BoundIndexerAccess( syntax, transformedReceiver, indexer, rewrittenArguments, default(ImmutableArray <string>), argumentRefKinds, false, default(ImmutableArray <int>), indexerAccess.Type)); } case BoundKind.Local: case BoundKind.Parameter: case BoundKind.ThisReference: // a special kind of parameter // No temporaries are needed. Just generate local = local + value return(originalLHS); case BoundKind.FieldAccess: { // * If the field is static then no temporaries are needed. // * If the field is not static and the receiver is of reference type then generate t = r; t.f = t.f + value // * If the field is not static and the receiver is a variable of value type then we'll fall into the // general variable case below. var fieldAccess = (BoundFieldAccess)originalLHS; BoundExpression receiverOpt = fieldAccess.ReceiverOpt; //If the receiver is static or is the receiver is of kind "Base" or "this", then we can just generate field = field + value if (fieldAccess.FieldSymbol.IsStatic || !IntroducingReadCanBeObservable(receiverOpt)) { return(fieldAccess); } if (receiverOpt.Type.IsReferenceType) { Debug.Assert(receiverOpt.Kind != BoundKind.TypeExpression); BoundExpression rewrittenReceiver = VisitExpression(receiverOpt); if (rewrittenReceiver.Type.IsTypeParameter()) { var memberContainingType = fieldAccess.FieldSymbol.ContainingType; // From the verifier prospective type parameters do not contain fields or methods. // the instance must be "boxed" to access the field // It makes sense to box receiver before storing into a temp - no need to box twice. rewrittenReceiver = BoxReceiver(rewrittenReceiver, memberContainingType); } BoundAssignmentOperator assignmentToTemp; var receiverTemp = _factory.StoreToTemp(rewrittenReceiver, out assignmentToTemp); stores.Add(assignmentToTemp); temps.Add(receiverTemp.LocalSymbol); return(new BoundFieldAccess(fieldAccess.Syntax, receiverTemp, fieldAccess.FieldSymbol, null)); } break; } case BoundKind.DynamicIndexerAccess: { var indexerAccess = (BoundDynamicIndexerAccess)originalLHS; BoundExpression loweredReceiver; if (IntroducingReadCanBeObservable(indexerAccess.ReceiverOpt)) { BoundAssignmentOperator assignmentToTemp; var temp = _factory.StoreToTemp(VisitExpression(indexerAccess.ReceiverOpt), out assignmentToTemp); stores.Add(assignmentToTemp); temps.Add(temp.LocalSymbol); loweredReceiver = temp; } else { loweredReceiver = indexerAccess.ReceiverOpt; } var arguments = indexerAccess.Arguments; var loweredArguments = new BoundExpression[arguments.Length]; for (int i = 0; i < arguments.Length; i++) { if (IntroducingReadCanBeObservable(arguments[i])) { BoundAssignmentOperator assignmentToTemp; var temp = _factory.StoreToTemp(VisitExpression(arguments[i]), out assignmentToTemp, refKind: indexerAccess.ArgumentRefKindsOpt.RefKinds(i)); stores.Add(assignmentToTemp); temps.Add(temp.LocalSymbol); loweredArguments[i] = temp; } else { loweredArguments[i] = arguments[i]; } } return(new BoundDynamicIndexerAccess( indexerAccess.Syntax, loweredReceiver, loweredArguments.AsImmutableOrNull(), indexerAccess.ArgumentNamesOpt, indexerAccess.ArgumentRefKindsOpt, indexerAccess.ApplicableIndexers, indexerAccess.Type)); } case BoundKind.ArrayAccess: if (isDynamicAssignment) { // In non-dynamic array[index] op= R we emit: // T& tmp = &array[index]; // *tmp = *L op R; // where T is the type of L. // // If L is an array access, the assignment is dynamic, the compile-time of the array is dynamic[] // and the runtime type of the array is not object[] (but e.g. string[]) the pointer approach is broken. // T is Object in such case and we can't take a read-write pointer of type Object& to an array element of non-object type. // // In this case we rewrite the assignment as follows: // // E t_array = array; // I t_index = index; (possibly more indices) // T value = t_array[t_index]; // t_array[t_index] = value op R; var arrayAccess = (BoundArrayAccess)originalLHS; var loweredArray = VisitExpression(arrayAccess.Expression); var loweredIndices = VisitList(arrayAccess.Indices); return(SpillArrayElementAccess(loweredArray, loweredIndices, stores, temps)); } break; case BoundKind.PointerElementAccess: case BoundKind.PointerIndirectionOperator: case BoundKind.RefValueOperator: break; default: throw ExceptionUtilities.UnexpectedValue(originalLHS.Kind); } // We made no transformation above. Either we have array[index] += value or // structVariable.field += value; either way we have a potentially complicated variable- // producing expression on the left. Generate // ref temp = ref variable; temp = temp + value // Rewrite the variable. Here we depend on the fact that the only forms // rewritten here are rewritten the same for lvalues and rvalues. BoundExpression rewrittenVariable = VisitExpression(originalLHS); BoundAssignmentOperator assignmentToTemp2; var variableTemp = _factory.StoreToTemp(rewrittenVariable, out assignmentToTemp2, refKind: RefKind.Ref); stores.Add(assignmentToTemp2); temps.Add(variableTemp.LocalSymbol); return(variableTemp); }
private BoundExpression MakeIndexerAccess( SyntaxNode syntax, BoundExpression rewrittenReceiver, PropertySymbol indexer, ImmutableArray <BoundExpression> rewrittenArguments, ImmutableArray <string> argumentNamesOpt, ImmutableArray <RefKind> argumentRefKindsOpt, bool expanded, ImmutableArray <int> argsToParamsOpt, TypeSymbol type, BoundIndexerAccess oldNodeOpt, bool isLeftOfAssignment) { // check for System.Array.[Length|LongLength] on a single dimensional array, // we have a special node for such cases. if (rewrittenReceiver != null && rewrittenReceiver.Type.IsArray() && !isLeftOfAssignment) { // NOTE: we are not interested in potential badness of Array.Length property. // If it is bad reference compare will not succeed. var specialIndexer = _compilation.GetSpecialTypeMember(SpecialMember.core_Array_T__item); if (ReferenceEquals(indexer.OriginalDefinition, specialIndexer)) { return(new BoundArrayAccess(syntax, rewrittenReceiver, rewrittenArguments[0], indexer.Type.TypeSymbol)); } } if (isLeftOfAssignment && indexer.RefKind == RefKind.None) { // This is an indexer set access. We return a BoundIndexerAccess node here. // This node will be rewritten with MakePropertyAssignment when rewriting the enclosing BoundAssignmentOperator. return(oldNodeOpt != null? oldNodeOpt.Update(rewrittenReceiver, indexer, rewrittenArguments, argumentNamesOpt, argumentRefKindsOpt, expanded, argsToParamsOpt, null, isLeftOfAssignment, type) : new BoundIndexerAccess(syntax, rewrittenReceiver, indexer, rewrittenArguments, argumentNamesOpt, argumentRefKindsOpt, expanded, argsToParamsOpt, null, isLeftOfAssignment, type)); } else { var getMethod = indexer.GetOwnOrInheritedGetMethod(); Debug.Assert((object)getMethod != null); // We have already lowered each argument, but we may need some additional rewriting for the arguments, // such as generating a params array, re-ordering arguments based on argsToParamsOpt map, inserting arguments for optional parameters, etc. ImmutableArray <LocalSymbol> temps; rewrittenArguments = MakeArguments( syntax, rewrittenArguments, indexer, getMethod, expanded, argsToParamsOpt, ref argumentRefKindsOpt, out temps, enableCallerInfo: ThreeState.True); BoundExpression call = MakePropertyGetAccess(syntax, rewrittenReceiver, indexer, rewrittenArguments, getMethod); if (temps.IsDefaultOrEmpty) { return(call); } else { return(new BoundSequence( syntax, temps, ImmutableArray <BoundExpression> .Empty, call, type)); } } }