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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Threading;
using Microsoft.CodeAnalysis.CodeGeneration;
using Microsoft.CodeAnalysis.CodeStyle;
using Microsoft.CodeAnalysis.CSharp.Extensions;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis.PooledObjects;
using Microsoft.CodeAnalysis.Shared.Extensions;
using Roslyn.Utilities;
namespace Microsoft.CodeAnalysis.CSharp.CodeGeneration;
using static CodeGenerationHelpers;
using static CSharpCodeGenerationHelpers;
using static CSharpSyntaxTokens;
using static SyntaxFactory;
internal static class PropertyGenerator
{
public static bool CanBeGenerated(IPropertySymbol property)
=> property.IsIndexer || property.Parameters.Length == 0;
private static MemberDeclarationSyntax? LastPropertyOrField(
SyntaxList<MemberDeclarationSyntax> members)
{
var lastProperty = members.LastOrDefault(m => m is PropertyDeclarationSyntax);
return lastProperty ?? LastField(members);
}
internal static CompilationUnitSyntax AddPropertyTo(
CompilationUnitSyntax destination,
IPropertySymbol property,
CSharpCodeGenerationContextInfo info,
IList<bool>? availableIndices,
CancellationToken cancellationToken)
{
var declaration = GeneratePropertyOrIndexer(
property, CodeGenerationDestination.CompilationUnit, info,
cancellationToken);
var members = Insert(destination.Members, declaration, info,
availableIndices, after: LastPropertyOrField, before: FirstMember);
return destination.WithMembers(members);
}
internal static TypeDeclarationSyntax AddPropertyTo(
TypeDeclarationSyntax destination,
IPropertySymbol property,
CSharpCodeGenerationContextInfo info,
IList<bool>? availableIndices,
CancellationToken cancellationToken)
{
var declaration = GeneratePropertyOrIndexer(property, GetDestination(destination), info, cancellationToken);
// Create a clone of the original type with the new method inserted.
var members = Insert(destination.Members, declaration, info,
availableIndices, after: LastPropertyOrField, before: FirstMember);
// Find the best place to put the field. It should go after the last field if we already
// have fields, or at the beginning of the file if we don't.
return AddMembersTo(destination, members, cancellationToken);
}
public static MemberDeclarationSyntax GeneratePropertyOrIndexer(
IPropertySymbol property,
CodeGenerationDestination destination,
CSharpCodeGenerationContextInfo info,
CancellationToken cancellationToken)
{
var reusableSyntax = GetReuseableSyntaxNodeForSymbol<MemberDeclarationSyntax>(property, info);
if (reusableSyntax != null)
{
return reusableSyntax;
}
var declaration = property.IsIndexer
? GenerateIndexerDeclaration(property, destination, info, cancellationToken)
: GeneratePropertyDeclaration(property, destination, info, cancellationToken);
return ConditionallyAddDocumentationCommentTo(declaration, property, info, cancellationToken);
}
private static MemberDeclarationSyntax GenerateIndexerDeclaration(
IPropertySymbol property,
CodeGenerationDestination destination,
CSharpCodeGenerationContextInfo info,
CancellationToken cancellationToken)
{
var explicitInterfaceSpecifier = GenerateExplicitInterfaceSpecifier(property.ExplicitInterfaceImplementations);
var declaration = IndexerDeclaration(
attributeLists: AttributeGenerator.GenerateAttributeLists(property.GetAttributes(), info),
modifiers: GenerateModifiers(property, destination, info),
type: GenerateTypeSyntax(property),
explicitInterfaceSpecifier: explicitInterfaceSpecifier,
parameterList: ParameterGenerator.GenerateBracketedParameterList(property.Parameters, explicitInterfaceSpecifier != null, info),
accessorList: GenerateAccessorList(property, destination, info, cancellationToken));
declaration = UseExpressionBodyIfDesired(info, declaration, cancellationToken);
return AddFormatterAndCodeGeneratorAnnotationsTo(
AddAnnotationsTo(property, declaration));
}
private static MemberDeclarationSyntax GeneratePropertyDeclaration(
IPropertySymbol property, CodeGenerationDestination destination,
CSharpCodeGenerationContextInfo info, CancellationToken cancellationToken)
{
var initializer = CodeGenerationPropertyInfo.GetInitializer(property) is ExpressionSyntax initializerNode
? EqualsValueClause(initializerNode)
: null;
var explicitInterfaceSpecifier = GenerateExplicitInterfaceSpecifier(property.ExplicitInterfaceImplementations);
var accessorList = GenerateAccessorList(property, destination, info, cancellationToken);
var propertyDeclaration = PropertyDeclaration(
attributeLists: AttributeGenerator.GenerateAttributeLists(property.GetAttributes(), info),
modifiers: GenerateModifiers(property, destination, info),
type: GenerateTypeSyntax(property),
explicitInterfaceSpecifier: explicitInterfaceSpecifier,
identifier: property.Name.ToIdentifierToken(),
accessorList: accessorList,
expressionBody: null,
initializer: initializer,
semicolonToken: initializer is null ? default : SemicolonToken);
propertyDeclaration = UseExpressionBodyIfDesired(info, propertyDeclaration, cancellationToken);
return AddFormatterAndCodeGeneratorAnnotationsTo(
AddAnnotationsTo(property, propertyDeclaration));
}
private static TypeSyntax GenerateTypeSyntax(IPropertySymbol property)
{
var returnType = property.Type;
if (property.ReturnsByRef)
{
return returnType.GenerateRefTypeSyntax();
}
else if (property.ReturnsByRefReadonly)
{
return returnType.GenerateRefReadOnlyTypeSyntax();
}
else
{
return returnType.GenerateTypeSyntax();
}
}
private static bool TryGetExpressionBody(
BasePropertyDeclarationSyntax baseProperty, LanguageVersion languageVersion, ExpressionBodyPreference preference, CancellationToken cancellationToken,
[NotNullWhen(true)] out ArrowExpressionClauseSyntax? arrowExpression, out SyntaxToken semicolonToken)
{
var accessorList = baseProperty.AccessorList;
if (preference != ExpressionBodyPreference.Never &&
accessorList?.Accessors.Count == 1)
{
var accessor = accessorList.Accessors[0];
if (accessor.IsKind(SyntaxKind.GetAccessorDeclaration))
{
return TryGetArrowExpressionBody(
baseProperty.Kind(), accessor, languageVersion, preference, cancellationToken,
out arrowExpression, out semicolonToken);
}
}
arrowExpression = null;
semicolonToken = default;
return false;
}
private static PropertyDeclarationSyntax UseExpressionBodyIfDesired(
CSharpCodeGenerationContextInfo info, PropertyDeclarationSyntax declaration, CancellationToken cancellationToken)
{
if (declaration.ExpressionBody == null)
{
if (declaration.Initializer == null)
{
if (TryGetExpressionBody(
declaration, info.LanguageVersion, info.Options.PreferExpressionBodiedProperties.Value, cancellationToken,
out var expressionBody, out var semicolonToken))
{
declaration = declaration.WithAccessorList(null)
.WithExpressionBody(expressionBody)
.WithSemicolonToken(semicolonToken);
}
}
}
return declaration;
}
private static IndexerDeclarationSyntax UseExpressionBodyIfDesired(
CSharpCodeGenerationContextInfo info, IndexerDeclarationSyntax declaration, CancellationToken cancellationToken)
{
if (declaration.ExpressionBody == null)
{
if (TryGetExpressionBody(
declaration, info.LanguageVersion, info.Options.PreferExpressionBodiedIndexers.Value, cancellationToken,
out var expressionBody, out var semicolonToken))
{
declaration = declaration.WithAccessorList(null)
.WithExpressionBody(expressionBody)
.WithSemicolonToken(semicolonToken);
}
}
return declaration;
}
private static AccessorDeclarationSyntax UseExpressionBodyIfDesired(
CSharpCodeGenerationContextInfo info, AccessorDeclarationSyntax declaration, CancellationToken cancellationToken)
{
if (declaration.ExpressionBody == null)
{
if (declaration.Body?.TryConvertToArrowExpressionBody(
declaration.Kind(), info.LanguageVersion, info.Options.PreferExpressionBodiedAccessors.Value, cancellationToken,
out var expressionBody, out var semicolonToken) == true)
{
declaration = declaration.WithBody(null)
.WithExpressionBody(expressionBody)
.WithSemicolonToken(semicolonToken);
}
}
return declaration;
}
private static bool TryGetArrowExpressionBody(
SyntaxKind declarationKind, AccessorDeclarationSyntax accessor, LanguageVersion languageVersion, ExpressionBodyPreference preference, CancellationToken cancellationToken,
[NotNullWhen(true)] out ArrowExpressionClauseSyntax? arrowExpression, out SyntaxToken semicolonToken)
{
// If the accessor has an expression body already, then use that as the expression body
// for the property.
if (accessor.ExpressionBody != null)
{
arrowExpression = accessor.ExpressionBody;
semicolonToken = accessor.SemicolonToken;
return true;
}
if (accessor.Body == null)
{
arrowExpression = null;
semicolonToken = default;
return false;
}
return accessor.Body.TryConvertToArrowExpressionBody(
declarationKind, languageVersion, preference, cancellationToken, out arrowExpression, out semicolonToken);
}
private static AccessorListSyntax? GenerateAccessorList(
IPropertySymbol property, CodeGenerationDestination destination,
CSharpCodeGenerationContextInfo info, CancellationToken cancellationToken)
{
var setAccessorKind = property.SetMethod?.IsInitOnly == true ? SyntaxKind.InitAccessorDeclaration : SyntaxKind.SetAccessorDeclaration;
var accessors = new[]
{
GenerateAccessorDeclaration(property, property.GetMethod, SyntaxKind.GetAccessorDeclaration, destination, info, cancellationToken),
GenerateAccessorDeclaration(property, property.SetMethod, setAccessorKind, destination, info, cancellationToken),
};
return accessors[0] == null && accessors[1] == null
? null
: AccessorList([.. accessors.WhereNotNull()]);
}
private static AccessorDeclarationSyntax? GenerateAccessorDeclaration(
IPropertySymbol property,
IMethodSymbol? accessor,
SyntaxKind kind,
CodeGenerationDestination destination,
CSharpCodeGenerationContextInfo info,
CancellationToken cancellationToken)
{
var hasBody = info.Context.GenerateMethodBodies && HasAccessorBodies(property, destination, accessor);
return accessor == null
? null
: GenerateAccessorDeclaration(property, accessor, kind, hasBody, info, cancellationToken);
}
private static AccessorDeclarationSyntax GenerateAccessorDeclaration(
IPropertySymbol property,
IMethodSymbol accessor,
SyntaxKind kind,
bool hasBody,
CSharpCodeGenerationContextInfo info,
CancellationToken cancellationToken)
{
var declaration = AccessorDeclaration(kind)
.WithModifiers(GenerateAccessorModifiers(property, accessor, info))
.WithBody(hasBody ? GenerateBlock(accessor) : null)
.WithSemicolonToken(hasBody ? default : SemicolonToken);
declaration = UseExpressionBodyIfDesired(info, declaration, cancellationToken);
return AddAnnotationsTo(accessor, declaration);
}
private static BlockSyntax GenerateBlock(IMethodSymbol accessor)
{
return Block(
StatementGenerator.GenerateStatements(CodeGenerationMethodInfo.GetStatements(accessor)));
}
private static bool HasAccessorBodies(
IPropertySymbol property,
CodeGenerationDestination destination,
IMethodSymbol? accessor)
{
return destination != CodeGenerationDestination.InterfaceType &&
!property.IsAbstract &&
accessor != null &&
!accessor.IsAbstract;
}
private static SyntaxTokenList GenerateAccessorModifiers(
IPropertySymbol property,
IMethodSymbol accessor,
CSharpCodeGenerationContextInfo info)
{
using var _ = ArrayBuilder<SyntaxToken>.GetInstance(out var modifiers);
if (accessor.DeclaredAccessibility != Accessibility.NotApplicable &&
accessor.DeclaredAccessibility != property.DeclaredAccessibility)
{
AddAccessibilityModifiers(accessor.DeclaredAccessibility, modifiers, info, property.DeclaredAccessibility);
}
var hasNonReadOnlyAccessor = property.GetMethod?.IsReadOnly == false || property.SetMethod?.IsReadOnly == false;
if (hasNonReadOnlyAccessor && accessor.IsReadOnly)
modifiers.Add(ReadOnlyKeyword);
return [.. modifiers];
}
private static SyntaxTokenList GenerateModifiers(
IPropertySymbol property, CodeGenerationDestination destination, CSharpCodeGenerationContextInfo info)
{
var tokens = ArrayBuilder<SyntaxToken>.GetInstance();
// Only "static" allowed if we're an explicit impl.
if (property.ExplicitInterfaceImplementations.Any())
{
if (property.IsStatic)
tokens.Add(StaticKeyword);
}
else
{
// If we're generating into an interface, then allow modifiers for static abstract members
if (destination is CodeGenerationDestination.InterfaceType)
{
if (property.IsStatic)
{
tokens.Add(StaticKeyword);
if (property.IsAbstract)
tokens.Add(AbstractKeyword);
}
}
else if (destination is not CodeGenerationDestination.CompilationUnit)
{
AddAccessibilityModifiers(property.DeclaredAccessibility, tokens, info, Accessibility.Private);
if (property.IsStatic)
tokens.Add(StaticKeyword);
// note: explicit interface impls are allowed to be 'readonly' but it never actually affects callers
// because of the boxing requirement in order to call the method.
// therefore it seems like a small oversight to leave out the keyword for an explicit impl from metadata.
var hasAllReadOnlyAccessors = property.GetMethod?.IsReadOnly != false && property.SetMethod?.IsReadOnly != false;
// Don't show the readonly modifier if the containing type is already readonly
if (hasAllReadOnlyAccessors && !property.ContainingType.IsReadOnly)
tokens.Add(ReadOnlyKeyword);
if (property.IsSealed)
tokens.Add(SealedKeyword);
if (property.IsOverride)
tokens.Add(OverrideKeyword);
if (property.IsVirtual)
tokens.Add(VirtualKeyword);
if (property.IsAbstract)
tokens.Add(AbstractKeyword);
if (property.IsRequired)
tokens.Add(RequiredKeyword);
}
}
if (CodeGenerationPropertyInfo.GetIsUnsafe(property))
tokens.Add(UnsafeKeyword);
return [.. tokens];
}
}
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