public static async Task <List <IMethodSymbol> > FindExtensionMethodsAsync(this ITypeSymbol type, Project project, CancellationToken cancellationToken = default)
{
var compilation = await project.GetCompilationAsync(cancellationToken).ConfigureAwait(false);
var members = new List <IMethodSymbol>(10);
var isValueType = type.IsValueType;
foreach (var typeSymbol in compilation.GlobalNamespace.GetAllTypes(cancellationToken))
{
if (typeSymbol.IsStatic == false || typeSymbol.MightContainExtensionMethods == false)
{
continue;
}
foreach (var member in typeSymbol.GetMembers())
{
if (cancellationToken.IsCancellationRequested)
{
return(members);
}
if (member.IsStatic == false || member.Kind != SymbolKind.Method)
{
continue;
}
var m = (IMethodSymbol)member;
if (m.IsExtensionMethod == false || m.CanBeReferencedByName == false)
{
continue;
}
var p = m.Parameters[0];
if (type.CanConvertTo(p.Type))
{
members.Add(m);
continue;
}
if (m.IsGenericMethod == false || p.Type.TypeKind != TypeKind.TypeParameter)
{
continue;
}
foreach (var item in m.TypeParameters)
{
if (item != p.Type ||
item.HasValueTypeConstraint && isValueType == false ||
item.HasReferenceTypeConstraint && isValueType)
{
continue;
}
if (item.HasConstructorConstraint)
{
}
if (item.ConstraintTypes.Length > 0 &&
item.ConstraintTypes.Any(i => i == type || type.CanConvertTo(i)) == false)
{
continue;
}
members.Add(m);
}
}
}
return(members);
}
/// <summary>
/// Finds all members defined or referenced in <paramref name="project"/> which may have a parameter that is of or derived from <paramref name="type"/>.
/// </summary>
public static async Task <List <ISymbol> > FindInstanceAsParameterAsync(this ITypeSymbol type, Project project, CancellationToken cancellationToken = default)
{
var compilation = await project.GetCompilationAsync(cancellationToken).ConfigureAwait(false);
var members = new List <ISymbol>(10);
ImmutableArray <IParameterSymbol> parameters;
var assembly = compilation.Assembly;
foreach (var typeSymbol in compilation.GlobalNamespace.GetAllTypes(cancellationToken))
{
foreach (var member in typeSymbol.GetMembers())
{
if (cancellationToken.IsCancellationRequested)
{
return(members);
}
if (member.Kind != SymbolKind.Field &&
member.CanBeReferencedByName &&
(parameters = member.GetParameters()).IsDefaultOrEmpty == false)
{
if (parameters.Any(p => type.CanConvertTo(p.Type) && p.Type.IsCommonClass() == false) &&
type.CanAccess(member, assembly))
{
members.Add(member);
}
}
}
}
return(members);
}
/// <summary>Checks whether the given symbol has the given <paramref name="kind"/>, <paramref name="returnType"/> and <paramref name="parameters"/>.</summary>
/// <param name="symbol">The symbol to be checked.</param>
/// <param name="kind">The <see cref="SymbolKind"/> the symbol should have.</param>
/// <param name="returnType">The type that the symbol should return.</param>
/// <param name="parameters">The parameters the symbol should take.</param>
public static bool MatchSignature(this ISymbol symbol, SymbolKind kind, ITypeSymbol returnType, ImmutableArray <IParameterSymbol> parameters)
{
if (symbol.Kind != kind)
{
return(false);
}
if (returnType == null && symbol.GetReturnType() != null ||
returnType != null && returnType.CanConvertTo(symbol.GetReturnType()) == false)
{
return(false);
}
var method = kind == SymbolKind.Method ? symbol as IMethodSymbol
: kind == SymbolKind.Event ? (symbol as IEventSymbol).RaiseMethod
: null;
if (method != null && parameters.IsDefault == false)
{
var memberParameters = method.Parameters;
if (memberParameters.Length != parameters.Length)
{
return(false);
}
for (var i = parameters.Length - 1; i >= 0; i--)
{
var pi = parameters[i];
var mi = memberParameters[i];
if (pi.Type.Equals(mi.Type) == false ||
pi.RefKind != mi.RefKind)
{
return(false);
}
}
}
return(true);
}
public static bool CanConvertTo(this ITypeSymbol symbol, ITypeSymbol target)
{
if (symbol.Equals(target))
{
return(true);
}
if (target.TypeKind == TypeKind.TypeParameter)
{
var param = target as ITypeParameterSymbol;
foreach (var item in param.ConstraintTypes)
{
if (item.CanConvertTo(symbol))
{
return(true);
}
}
return(false);
}
if (symbol.TypeKind == TypeKind.TypeParameter)
{
var param = symbol as ITypeParameterSymbol;
foreach (var item in param.ConstraintTypes)
{
if (item.CanConvertTo(target))
{
return(true);
}
}
return(false);
}
foreach (var item in symbol.Interfaces)
{
if (item.CanConvertTo(target))
{
return(true);
}
}
while ((symbol = symbol.BaseType) != null)
{
if (symbol.CanConvertTo(target))
{
return(true);
}
}
return(false);
}
