Example #1
0
        public static Imports FromSyntax(
            CSharpSyntaxNode declarationSyntax,
            InContainerBinder binder,
            ConsList <TypeSymbol> basesBeingResolved,
            bool inUsing)
        {
            SyntaxList <UsingDirectiveSyntax>       usingDirectives;
            SyntaxList <ExternAliasDirectiveSyntax> externAliasDirectives;

            if (declarationSyntax.Kind() == SyntaxKind.CompilationUnit)
            {
                var compilationUnit = (CompilationUnitSyntax)declarationSyntax;
                // using directives are not in scope within using directives
                usingDirectives       = inUsing ? default(SyntaxList <UsingDirectiveSyntax>) : compilationUnit.Usings;
                externAliasDirectives = compilationUnit.Externs;
            }
            else if (declarationSyntax.Kind() == SyntaxKind.NamespaceDeclaration)
            {
                var namespaceDecl = (NamespaceDeclarationSyntax)declarationSyntax;
                // using directives are not in scope within using directives
                usingDirectives       = inUsing ? default(SyntaxList <UsingDirectiveSyntax>) : namespaceDecl.Usings;
                externAliasDirectives = namespaceDecl.Externs;
            }
            else
            {
                return(Empty);
            }

            if (usingDirectives.Count == 0 && externAliasDirectives.Count == 0)
            {
                return(Empty);
            }

            // define all of the extern aliases first. They may used by the target of a using

            // using Bar=Goo::Bar;
            // using Goo::Baz;
            // extern alias Goo;

            var diagnostics = new DiagnosticBag();

            var compilation = binder.Compilation;

            var externAliases = BuildExternAliases(externAliasDirectives, binder, diagnostics);
            var usings        = ArrayBuilder <NamespaceOrTypeAndUsingDirective> .GetInstance();

            ImmutableDictionary <string, AliasAndUsingDirective> .Builder usingAliases = null;
            if (usingDirectives.Count > 0)
            {
                // A binder that contains the extern aliases but not the usings. The resolution of the target of a using directive or alias
                // should not make use of other peer usings.
                Binder usingsBinder;
                if (declarationSyntax.SyntaxTree.Options.Kind != SourceCodeKind.Regular)
                {
                    usingsBinder = compilation.GetBinderFactory(declarationSyntax.SyntaxTree).GetImportsBinder(declarationSyntax, inUsing: true);
                }
                else
                {
                    var imports = externAliases.Length == 0
                        ? Empty
                        : new Imports(
                        compilation,
                        ImmutableDictionary <string, AliasAndUsingDirective> .Empty,
                        ImmutableArray <NamespaceOrTypeAndUsingDirective> .Empty,
                        externAliases,
                        diagnostics: null);
                    usingsBinder = new InContainerBinder(binder.Container, binder.Next, imports);
                }

                var uniqueUsings = SpecializedSymbolCollections.GetPooledSymbolHashSetInstance <NamespaceOrTypeSymbol>();

                foreach (var usingDirective in usingDirectives)
                {
                    compilation.RecordImport(usingDirective);

                    if (usingDirective.Alias != null)
                    {
                        SyntaxToken identifier = usingDirective.Alias.Name.Identifier;
                        Location    location   = usingDirective.Alias.Name.Location;

                        if (identifier.ContextualKind() == SyntaxKind.GlobalKeyword)
                        {
                            diagnostics.Add(ErrorCode.WRN_GlobalAliasDefn, location);
                        }

                        if (usingDirective.StaticKeyword != default(SyntaxToken))
                        {
                            diagnostics.Add(ErrorCode.ERR_NoAliasHere, location);
                        }

                        SourceMemberContainerTypeSymbol.ReportTypeNamedRecord(identifier.Text, compilation, diagnostics, location);

                        string identifierValueText = identifier.ValueText;
                        if (usingAliases != null && usingAliases.ContainsKey(identifierValueText))
                        {
                            // Suppress diagnostics if we're already broken.
                            if (!usingDirective.Name.IsMissing)
                            {
                                // The using alias '{0}' appeared previously in this namespace
                                diagnostics.Add(ErrorCode.ERR_DuplicateAlias, location, identifierValueText);
                            }
                        }
                        else
                        {
                            // an O(m*n) algorithm here but n (number of extern aliases) will likely be very small.
                            foreach (var externAlias in externAliases)
                            {
                                if (externAlias.Alias.Name == identifierValueText)
                                {
                                    // The using alias '{0}' appeared previously in this namespace
                                    diagnostics.Add(ErrorCode.ERR_DuplicateAlias, usingDirective.Location, identifierValueText);
                                    break;
                                }
                            }

                            if (usingAliases == null)
                            {
                                usingAliases = ImmutableDictionary.CreateBuilder <string, AliasAndUsingDirective>();
                            }

                            // construct the alias sym with the binder for which we are building imports. That
                            // way the alias target can make use of extern alias definitions.
                            usingAliases.Add(identifierValueText, new AliasAndUsingDirective(new AliasSymbol(usingsBinder, usingDirective.Name, usingDirective.Alias), usingDirective));
                        }
                    }
                    else
                    {
                        if (usingDirective.Name.IsMissing)
                        {
                            //don't try to lookup namespaces inserted by parser error recovery
                            continue;
                        }

                        var declarationBinder = usingsBinder.WithAdditionalFlags(BinderFlags.SuppressConstraintChecks);
                        var imported          = declarationBinder.BindNamespaceOrTypeSymbol(usingDirective.Name, diagnostics, basesBeingResolved).NamespaceOrTypeSymbol;
                        if (imported.Kind == SymbolKind.Namespace)
                        {
                            if (usingDirective.StaticKeyword != default(SyntaxToken))
                            {
                                diagnostics.Add(ErrorCode.ERR_BadUsingType, usingDirective.Name.Location, imported);
                            }
                            else if (uniqueUsings.Contains(imported))
                            {
                                diagnostics.Add(ErrorCode.WRN_DuplicateUsing, usingDirective.Name.Location, imported);
                            }
                            else
                            {
                                uniqueUsings.Add(imported);
                                usings.Add(new NamespaceOrTypeAndUsingDirective(imported, usingDirective));
                            }
                        }
                        else if (imported.Kind == SymbolKind.NamedType)
                        {
                            if (usingDirective.StaticKeyword == default(SyntaxToken))
                            {
                                diagnostics.Add(ErrorCode.ERR_BadUsingNamespace, usingDirective.Name.Location, imported);
                            }
                            else
                            {
                                var importedType = (NamedTypeSymbol)imported;
                                if (uniqueUsings.Contains(importedType))
                                {
                                    diagnostics.Add(ErrorCode.WRN_DuplicateUsing, usingDirective.Name.Location, importedType);
                                }
                                else
                                {
                                    declarationBinder.ReportDiagnosticsIfObsolete(diagnostics, importedType, usingDirective.Name, hasBaseReceiver: false);

                                    uniqueUsings.Add(importedType);
                                    usings.Add(new NamespaceOrTypeAndUsingDirective(importedType, usingDirective));
                                }
                            }
                        }
                        else if (imported.Kind != SymbolKind.ErrorType)
                        {
                            // Do not report additional error if the symbol itself is erroneous.

                            // error: '<symbol>' is a '<symbol kind>' but is used as 'type or namespace'
                            diagnostics.Add(ErrorCode.ERR_BadSKknown, usingDirective.Name.Location,
                                            usingDirective.Name,
                                            imported.GetKindText(),
                                            MessageID.IDS_SK_TYPE_OR_NAMESPACE.Localize());
                        }
                    }
                }

                uniqueUsings.Free();
            }

            if (diagnostics.IsEmptyWithoutResolution)
            {
                diagnostics = null;
            }

            return(new Imports(compilation, usingAliases.ToImmutableDictionaryOrEmpty(), usings.ToImmutableAndFree(), externAliases, diagnostics));
        }