internal static FieldDeclarationSyntax AddBackingField(this DocumentEditor editor, PropertyDeclarationSyntax propertyDeclaration, bool usesUnderscoreNames, CancellationToken cancellationToken)
{
var property = editor.SemanticModel.GetDeclaredSymbolSafe(propertyDeclaration, cancellationToken);
var name = usesUnderscoreNames
? $"_{property.Name.ToFirstCharLower()}"
: property.Name.ToFirstCharLower();
while (property.ContainingType.MemberNames.Any(x => x == name))
{
name += "_";
}
if (SyntaxFacts.GetKeywordKind(name) != SyntaxKind.None ||
SyntaxFacts.GetContextualKeywordKind(name) != SyntaxKind.None)
{
name = "@" + name;
}
var backingField = (FieldDeclarationSyntax)editor.Generator.FieldDeclaration(
name,
accessibility: Accessibility.Private,
modifiers: DeclarationModifiers.None,
type: propertyDeclaration.Type,
initializer: propertyDeclaration.Initializer?.Value);
var type = (TypeDeclarationSyntax)propertyDeclaration.Parent;
editor.ReplaceNode(
type,
(node, generator) => AddBackingField((TypeDeclarationSyntax)node, backingField, property.Name, generator));
return(backingField);
}
/// <summary>
/// Create a backing <see cref="FieldDeclarationSyntax"/> for the <paramref name="propertyDeclaration"/>
/// Handles name collisions and reserved keywords.
/// </summary>
/// <param name="editor">The <see cref="DocumentEditor"/>.</param>
/// <param name="propertyDeclaration">The <see cref="PropertyDeclarationSyntax"/>.</param>
/// <returns>A <see cref="FieldDeclarationSyntax"/>.</returns>
public static FieldDeclarationSyntax CreateBackingField(this DocumentEditor editor, PropertyDeclarationSyntax propertyDeclaration)
{
if (editor is null)
{
throw new System.ArgumentNullException(nameof(editor));
}
if (propertyDeclaration is null)
{
throw new System.ArgumentNullException(nameof(propertyDeclaration));
}
var property = editor.SemanticModel.GetDeclaredSymbol(propertyDeclaration);
var name = editor.SemanticModel.UnderscoreFields() == CodeStyleResult.Yes
? $"_{property.Name.ToFirstCharLower()}"
: property.Name.ToFirstCharLower();
while (property.ContainingType.MemberNames.Any(x => x == name))
{
name += "_";
}
if (SyntaxFacts.GetKeywordKind(name) != SyntaxKind.None ||
SyntaxFacts.GetContextualKeywordKind(name) != SyntaxKind.None)
{
name = "@" + name;
}
return((FieldDeclarationSyntax)editor.Generator.FieldDeclaration(
name,
accessibility: Accessibility.Private,
modifiers: DeclarationModifiers.None,
type: propertyDeclaration.Type,
initializer: propertyDeclaration.Initializer?.Value));
}
public static bool IsKeyword(this string name)
{
var isAnyKeyword = SyntaxFacts.GetKeywordKind(name) != SyntaxKind.None ||
SyntaxFacts.GetContextualKeywordKind(name) != SyntaxKind.None;
return(isAnyKeyword);
}
protected override Task <ImmutableArray <(ISymbol symbol, bool preselect)> > GetSymbolsAsync(
CompletionContext?completionContext,
CSharpSyntaxContext context,
int position,
OptionSet options,
CancellationToken cancellationToken
)
{
var targetToken = context.TargetToken;
// Don't want to offer this after "async" (even though the compiler may parse that as a type).
if (
SyntaxFacts.GetContextualKeywordKind(targetToken.ValueText)
== SyntaxKind.AsyncKeyword
)
{
return(SpecializedTasks.EmptyImmutableArray <(ISymbol symbol, bool preselect)>());
}
var typeNode = targetToken.Parent as TypeSyntax;
while (typeNode != null)
{
if (typeNode.Parent is TypeSyntax parentType && parentType.Span.End < position)
{
typeNode = parentType;
}
public SyntaxKind GetKind()
{
if (Kind != SyntaxKind.None)
{
return(Kind);
}
return(SyntaxFacts.GetAccessorDeclarationKind(SyntaxFacts.GetContextualKeywordKind(KeywordStr)));
}
private static void HandleXmlNodeSyntax(SyntaxNodeAnalysisContext context)
{
var xmlNodeSyntax = (XmlNodeSyntax)context.Node;
var name = xmlNodeSyntax.GetName();
if (name is null || name.Prefix != null)
{
return;
}
if (name.LocalName.ValueText != XmlCommentHelper.SeeXmlTag)
{
return;
}
SyntaxList <XmlAttributeSyntax> attributes;
if (xmlNodeSyntax is XmlEmptyElementSyntax xmlEmptyElement)
{
attributes = xmlEmptyElement.Attributes;
}
else
{
attributes = ((XmlElementSyntax)xmlNodeSyntax).StartTag.Attributes;
}
foreach (var attribute in attributes)
{
if (attribute.Name is null || attribute.Name.Prefix != null)
{
continue;
}
if (attribute.Name.LocalName.ValueText != XmlCommentHelper.LangwordArgumentName)
{
continue;
}
var text = ((XmlTextAttributeSyntax)attribute).TextTokens;
string valueText;
if (text.Count == 1)
{
valueText = text[0].ValueText;
}
else
{
valueText = string.Join(string.Empty, text.Select(textToken => textToken.ValueText));
}
if (SyntaxFacts.GetKeywordKind(valueText) != SyntaxKind.None ||
SyntaxFacts.GetContextualKeywordKind(valueText) != SyntaxKind.None)
{
continue;
}
context.ReportDiagnostic(Diagnostic.Create(Descriptor, attribute.Name.LocalName.GetLocation()));
}
}
private static bool IsKeyWord(string identifier)
{
if (SyntaxFacts.GetKeywordKind(identifier) != SyntaxKind.None ||
SyntaxFacts.GetContextualKeywordKind(identifier) != SyntaxKind.None)
{
return(true);
}
return(false);
}
internal static ClassifiedSpan AdjustStaleClassification(SourceText rawText, ClassifiedSpan classifiedSpan)
{
// If we marked this as an identifier and it should now be a keyword
// (or vice versa), then fix this up and return it.
var classificationType = classifiedSpan.ClassificationType;
// Check if the token's type has changed. Note: we don't check for "wasPPKeyword &&
// !isPPKeyword" here. That's because for fault tolerance any identifier will end up
// being parsed as a PP keyword eventually, and if we have the check here, the text
// flickers between blue and black while typing. See
// http://vstfdevdiv:8080/web/wi.aspx?id=3521 for details.
var wasKeyword = classificationType == ClassificationTypeNames.Keyword;
var wasIdentifier = classificationType == ClassificationTypeNames.Identifier;
// We only do this for identifiers/keywords.
if (wasKeyword || wasIdentifier)
{
// Get the current text under the tag.
var span = classifiedSpan.TextSpan;
var text = rawText.ToString(span);
// Now, try to find the token that corresponds to that text. If
// we get 0 or 2+ tokens, then we can't do anything with this.
// Also, if that text includes trivia, then we can't do anything.
var token = SyntaxFactory.ParseToken(text);
if (token.Span.Length == span.Length)
{
// var and dynamic are not contextual keywords. They are always identifiers
// (that we classify as keywords). Because we are just parsing a token we don't
// know if we're in the right context for them to be identifiers or keywords.
// So, we base on decision on what they were before. i.e. if we had a keyword
// before, then assume it stays a keyword if we see 'var' or 'dynamic.
var isKeyword = SyntaxFacts.IsKeywordKind(token.CSharpKind()) ||
(wasKeyword && SyntaxFacts.GetContextualKeywordKind(text) != SyntaxKind.None) ||
(wasKeyword && token.ToString() == "var") ||
(wasKeyword && token.ToString() == "dynamic");
var isIdentifier = token.CSharpKind() == SyntaxKind.IdentifierToken;
// We only do this for identifiers/keywords.
if (isKeyword || isIdentifier)
{
if ((wasKeyword && !isKeyword) ||
(wasIdentifier && !isIdentifier))
{
// It changed! Return the new type of tagspan.
return(new ClassifiedSpan(
isKeyword ? ClassificationTypeNames.Keyword : ClassificationTypeNames.Identifier, span));
}
}
}
}
// didn't need to do anything to this one.
return(classifiedSpan);
}
public void SyntaxFacts_Keyword_GetContextualKeywordKind_DetectsAllContextualKeywords()
{
foreach (var kind in SyntaxFacts.GetContextualKeywordKinds())
{
var text = kind.GetText();
var keywordKind = SyntaxFacts.GetContextualKeywordKind(text);
Assert.Equal(kind, keywordKind);
}
}
public void SyntaxFacts_Keyword_GetContextualKeywordKind_DetectsAllContextualKeywords_RegardlessOfCase()
{
foreach (var kind in SyntaxFacts.GetContextualKeywordKinds())
{
var text = kind.GetText();
var textWithMixedCast = GetMixedCase(text);
var keywordKind = SyntaxFacts.GetContextualKeywordKind(textWithMixedCast);
Assert.Equal(kind, keywordKind);
}
}
public virtual string Identifier([NotNull] string name, [CanBeNull] ICollection <string> scope = null)
{
Check.NotEmpty(name, nameof(name));
var builder = new StringBuilder();
var partStart = 0;
for (var i = 0; i < name.Length; i++)
{
if (!SyntaxFacts.IsIdentifierPartCharacter(name[i]))
{
if (partStart != i)
{
builder.Append(name.Substring(partStart, i - partStart));
}
partStart = i + 1;
}
}
if (partStart != name.Length)
{
builder.Append(name.Substring(partStart));
}
if (!SyntaxFacts.IsIdentifierStartCharacter(builder[0]))
{
builder.Insert(0, "_");
}
var identifier = builder.ToString();
if (scope != null)
{
var uniqueIdentifier = identifier;
var qualifier = 0;
while (scope.Contains(uniqueIdentifier))
{
uniqueIdentifier = identifier + qualifier++;
}
scope.Add(uniqueIdentifier);
identifier = uniqueIdentifier;
}
if (SyntaxFacts.GetKeywordKind(identifier) != SyntaxKind.None ||
SyntaxFacts.GetPreprocessorKeywordKind(identifier) != SyntaxKind.None ||
SyntaxFacts.GetContextualKeywordKind(identifier) != SyntaxKind.None)
{
return("@" + identifier);
}
return(identifier);
}
public static SyntaxToken TryEscapeIdentifierToken(
SyntaxToken syntaxToken,
SyntaxNode parentOfToken
)
{
// do not escape an already escaped identifier
if (syntaxToken.IsVerbatimIdentifier())
{
return(syntaxToken);
}
if (
SyntaxFacts.GetKeywordKind(syntaxToken.ValueText) == SyntaxKind.None &&
SyntaxFacts.GetContextualKeywordKind(syntaxToken.ValueText) == SyntaxKind.None
)
{
return(syntaxToken);
}
if (
SyntaxFacts.GetContextualKeywordKind(syntaxToken.ValueText)
== SyntaxKind.UnderscoreToken
)
{
return(syntaxToken);
}
var parent = parentOfToken.Parent;
if (parentOfToken is SimpleNameSyntax && parent.Kind() == SyntaxKind.XmlNameAttribute)
{
// do not try to escape XML name attributes
return(syntaxToken);
}
// do not escape global in a namespace qualified name
if (parent.Kind() == SyntaxKind.AliasQualifiedName && syntaxToken.ValueText == "global")
{
return(syntaxToken);
}
// safe to escape identifier
return(syntaxToken
.CopyAnnotationsTo(
SyntaxFactory.VerbatimIdentifier(
syntaxToken.LeadingTrivia,
syntaxToken.ToString(),
syntaxToken.ValueText,
syntaxToken.TrailingTrivia
)
)
.WithAdditionalAnnotations(Simplifier.Annotation));
}
private static IdentifierNameSyntax CreateIdentifierName(ISymbol candidate)
{
var identifier = candidate.Name;
bool isAnyKeyword = SyntaxFacts.GetKeywordKind(identifier) != SyntaxKind.None ||
SyntaxFacts.GetContextualKeywordKind(identifier) != SyntaxKind.None;
if (isAnyKeyword)
{
return(SyntaxFactory.IdentifierName("@" + identifier));
}
return(SyntaxFactory.IdentifierName(identifier));
}
static SyntaxToken CreateIdentifier(string text)
{
if (SyntaxFacts.GetKeywordKind(text) != SyntaxKind.None ||
SyntaxFacts.GetContextualKeywordKind(text) != SyntaxKind.None
)
{
return
(SyntaxFactory.VerbatimIdentifier(
SyntaxFactory.TriviaList(),
text,
text,
SyntaxFactory.TriviaList()
));
}
return(SyntaxFactory.Identifier(text));
}
/// <summary>
/// Returns true if this token is something that looks like a C# keyword. This includes
/// actual keywords, contextual keywords, and even 'var' and 'dynamic'
/// </summary>
/// <param name="token"></param>
/// <returns></returns>
public static bool CouldBeKeyword(this SyntaxToken token)
{
if (token.IsKeyword())
{
return(true);
}
if (token.Kind() == SyntaxKind.IdentifierToken)
{
var simpleNameText = token.ValueText;
return(simpleNameText == "var" ||
simpleNameText == "dynamic" ||
SyntaxFacts.GetContextualKeywordKind(simpleNameText) != SyntaxKind.None);
}
return(false);
}
internal static string Name(this FieldDeclarationSyntax declaration)
{
VariableDeclaratorSyntax variable = null;
if (declaration?.Declaration?.Variables.TrySingle(out variable) == true)
{
if (SyntaxFacts.GetKeywordKind(variable.Identifier.ValueText) != SyntaxKind.None ||
SyntaxFacts.GetContextualKeywordKind(variable.Identifier.ValueText) != SyntaxKind.None)
{
return("@" + variable.Identifier.ValueText);
}
return(variable.Identifier.ValueText);
}
throw new InvalidOperationException($"Could not get name of field {declaration}");
}
private static string Name(IPropertySymbol property, SemanticModel semanticModel)
{
var name = semanticModel.UnderscoreFields() == CodeStyleResult.Yes
? $"_{property.Name.ToFirstCharLower()}"
: property.Name.ToFirstCharLower();
while (property.ContainingType.MemberNames.Any(x => x == name))
{
name += "_";
}
if (SyntaxFacts.GetKeywordKind(name) != SyntaxKind.None ||
SyntaxFacts.GetContextualKeywordKind(name) != SyntaxKind.None)
{
name = "@" + name;
}
return(name);
}
public static string SanitiseFieldName(this string name)
{
name = Regex.Replace(name, @"[\W\b]", "_", RegexOptions.IgnoreCase);
name = Regex.Replace(name, @"^\d", @"_$0");
int i = 0;
while (SyntaxFacts.GetKeywordKind(name) != SyntaxKind.None ||
SyntaxFacts.GetContextualKeywordKind(name) != SyntaxKind.None ||
!SyntaxFacts.IsValidIdentifier(name))
{
if (i++ > 10)
{
return(name); // Sanity check.. The loop might be loopy!
}
name = "_" + name;
}
return(name);
}
private static bool IsProbablySyntacticConstruct(SyntaxToken token)
{
// Technically all C# contextual keywords are valid member names.
// However some of them start various syntactic constructs
// and we don't want to show "Generate <member name>" codefix for them:
// 1. "from" starts LINQ expression
// 2. "nameof" is probably nameof(some_name)
// 3. "async" can start a delegate declaration
// 4. "await" starts await expression
// 5. "var" is used in constructions like "var x = ..."
// The list can be expanded in the future if necessary
// This method tells if the given SyntaxToken is one of the cases above
var contextualKind = SyntaxFacts.GetContextualKeywordKind(token.ValueText);
return(contextualKind is SyntaxKind.FromKeyword or
SyntaxKind.NameOfKeyword or
SyntaxKind.AsyncKeyword or
SyntaxKind.AwaitKeyword or
SyntaxKind.VarKeyword);
}
private void ReadIdentifierOrKeyword()
{
var start = _charReader.Position;
// Skip first letter
NextChar();
// The following characters can be letters, digits the underscore and the dollar sign.
while (char.IsLetterOrDigit(_charReader.Current) ||
_charReader.Current == '_' ||
_charReader.Current == '$')
{
NextChar();
}
var end = _charReader.Position;
var span = TextSpan.FromBounds(start, end);
var text = File.Text.GetSubText(span).ToString();
_kind = SyntaxFacts.GetKeywordKind(text);
_contextualKind = (_mode == LexerMode.Directive)
? SyntaxFacts.GetPreprocessorKeywordKind(text)
: SyntaxFacts.GetContextualKeywordKind(text);
switch (_kind)
{
case SyntaxKind.TrueKeyword:
_value = true;
break;
case SyntaxKind.FalseKeyword:
_value = false;
break;
default:
_value = text;
break;
}
}
private void ReadIdentifierOrKeyword()
{
var start = _charReader.Position;
// Skip first letter
NextChar();
// The following characters can be letters, digits the underscore and the dollar sign.
while (char.IsLetterOrDigit(_charReader.Current) ||
_charReader.Current == '_' ||
_charReader.Current == '$')
{
NextChar();
}
var end = _charReader.Position;
var span = TextSpan.FromBounds(Text, start, end);
var text = Text.GetText(span);
_kind = SyntaxFacts.GetUnityKeywordKind(text);
_contextualKind = SyntaxFacts.GetContextualKeywordKind(text);
switch (_kind)
{
case SyntaxKind.TrueKeyword:
_value = true;
break;
case SyntaxKind.FalseKeyword:
_value = false;
break;
default:
_value = text;
break;
}
}
public override Task ProvideArgumentAsync(ArgumentContext context)
{
if (context.PreviousValue is not null)
{
// This argument provider does not attempt to replace arguments already in code.
return(Task.CompletedTask);
}
if (context.Parameter.RefKind != RefKind.Out)
{
// This argument provider only considers 'out' parameters.
return(Task.CompletedTask);
}
// Since tihs provider runs after ContextVariableArgumentProvider, we know there is no suitable target in
// the current context. Instead, offer to declare a new variable.
var name = context.Parameter.Name;
if (SyntaxFacts.GetKeywordKind(name) != SyntaxKind.None ||
SyntaxFacts.GetContextualKeywordKind(name) != SyntaxKind.None)
{
name = "@" + name;
}
var syntax = SyntaxFactory.Argument(
nameColon: null,
refKindKeyword: SyntaxFactory.Token(SyntaxKind.OutKeyword),
SyntaxFactory.DeclarationExpression(
type: SyntaxFactory.IdentifierName("var"),
designation: SyntaxFactory.SingleVariableDesignation(SyntaxFactory.Identifier(
SyntaxFactory.TriviaList(),
contextualKind: SyntaxKind.None,
text: name,
valueText: context.Parameter.Name,
SyntaxFactory.TriviaList()))));
context.DefaultValue = syntax.NormalizeWhitespace().ToFullString();
return(Task.CompletedTask);
}
/// <summary>
/// Create a backing <see cref="FieldDeclarationSyntax"/> for the <paramref name="propertyDeclaration"/>
/// Handles name collisions and reserved keywords.
/// </summary>
/// <param name="editor">The <see cref="DocumentEditor"/>.</param>
/// <param name="propertyDeclaration">The <see cref="PropertyDeclarationSyntax"/>.</param>
/// <returns>A <see cref="FieldDeclarationSyntax"/>.</returns>
public static FieldDeclarationSyntax CreateBackingField(this DocumentEditor editor, PropertyDeclarationSyntax propertyDeclaration)
{
if (editor is null)
{
throw new System.ArgumentNullException(nameof(editor));
}
if (propertyDeclaration is null)
{
throw new System.ArgumentNullException(nameof(propertyDeclaration));
}
if (propertyDeclaration.Parent is TypeDeclarationSyntax type)
{
var name = editor.SemanticModel.UnderscoreFields() == CodeStyleResult.Yes
? $"_{propertyDeclaration.Identifier.ValueText.ToFirstCharLower()}"
: propertyDeclaration.Identifier.ValueText.ToFirstCharLower();
while (type.TryFindField(name, out _))
{
name += "_";
}
if (SyntaxFacts.GetKeywordKind(name) != SyntaxKind.None ||
SyntaxFacts.GetContextualKeywordKind(name) != SyntaxKind.None)
{
name = "@" + name;
}
return((FieldDeclarationSyntax)editor.Generator.FieldDeclaration(
name,
accessibility: Accessibility.Private,
modifiers: DeclarationModifiers.None,
type: propertyDeclaration.Type,
initializer: propertyDeclaration.Initializer?.Value));
}
throw new System.ArgumentNullException(nameof(propertyDeclaration), "Property.Parent is not a TypeDeclaration.");
}
public static string EscapeIdentifier(this string identifier, bool isQueryContext = false)
{
var nullIndex = identifier.IndexOf('\0');
if (nullIndex >= 0)
{
identifier = identifier.Substring(0, nullIndex);
}
var needsEscaping = SyntaxFacts.GetKeywordKind(identifier) != SyntaxKind.None;
// Check if we need to escape this contextual keyword
needsEscaping =
needsEscaping ||
(
isQueryContext &&
SyntaxFacts.IsQueryContextualKeyword(
SyntaxFacts.GetContextualKeywordKind(identifier)
)
);
return(needsEscaping ? "@" + identifier : identifier);
}
private void ReadIdentifierOrKeyword()
{
var start = _charReader.Position;
// Skip first letter
_charReader.NextChar();
// The following characters can be letters, digits the underscore and the dollar sign.
while (char.IsLetterOrDigit(_charReader.Current) ||
_charReader.Current == '_' ||
_charReader.Current == '$')
{
_charReader.NextChar();
}
var end = _charReader.Position;
var span = TextSpan.FromBounds(start, end);
var text = _text.GetText(span);
_kind = SyntaxFacts.GetKeywordKind(text);
_contextualKind = SyntaxFacts.GetContextualKeywordKind(text);
_value = text;
}
protected override int GetKeywordKind(string trimmed)
{
var kind = SyntaxFacts.GetKeywordKind(trimmed);
return((int)(kind == SyntaxKind.None ? SyntaxFacts.GetContextualKeywordKind(trimmed) : kind));
}
public FieldInfoWrapper(IFieldSymbol parameter, MetadataLoadContextInternal metadataLoadContext)
{
_field = parameter;
_metadataLoadContext = metadataLoadContext;
NeedsAtSign = SyntaxFacts.GetKeywordKind(_field.Name) != SyntaxKind.None || SyntaxFacts.GetContextualKeywordKind(_field.Name) != SyntaxKind.None;
}
private static bool IsPotentialKeyword(string identifier)
{
return(SyntaxFacts.GetKeywordKind(identifier) != SyntaxKind.None ||
SyntaxFacts.GetContextualKeywordKind(identifier) != SyntaxKind.None);
}
public void SyntaxFacts_Keyword_GetContextualKeywordKind_ReturnsIdentifier_IfNotKeyword()
{
var keywordKind = SyntaxFacts.GetContextualKeywordKind("ipsum");
Assert.Equal(SyntaxKind.IdentifierToken, keywordKind);
}
public void SyntaxFacts_Keyword_GetContextualKeywordKind_ThrowsArgumentNullException_IfTextIsNull()
{
Assert.Throws <ArgumentNullException>(() => SyntaxFacts.GetContextualKeywordKind(null));
}
