TryMatchGetConstructor

Author: JohanLarsson

ReflectionAnalyzers/Helpers/GetX.cs

@@ -17,6 +17,30 @@ internal static class GetX
         public static IReadOnlyList<ITypeSymbol> AnyTypes = new ITypeSymbol[0];
 #pragma warning restore CA1825 // Avoid zero-length array allocations.
 
+        /// <summary>
+        /// Check if <paramref name="invocation"/> is a call to Type.GetMethod
+        /// </summary>
+        internal static GetXResult? TryMatchGetConstructor(InvocationExpressionSyntax invocation, SyntaxNodeAnalysisContext context, out ITypeSymbol targetType, out ISymbol target, out ArgumentSyntax flagsArg, out BindingFlags effectiveFlags, out ArgumentSyntax typesArg, out IReadOnlyList<ITypeSymbol> types)
+        {
+            targetType = null;
+            target = null;
+            flagsArg = null;
+            effectiveFlags = 0;
+            typesArg = null;
+            types = null;
+            if (invocation.ArgumentList != null &&
+                invocation.TryGetTarget(KnownSymbol.Type.GetConstructor, context.SemanticModel, context.CancellationToken, out var getX) &&
+                TryGetTargetType(invocation, context, out targetType, out _) &&
+                IsKnownSignature(invocation, getX) &&
+                TryGetFlagsOrDefault(invocation, getX, context, out flagsArg, out effectiveFlags) &&
+                TryGetTypesOrDefault(invocation, getX, context, out typesArg, out types))
+            {
+                return TryGetTarget(getX, targetType, ".ctor", effectiveFlags, types, context, out target);
+            }
+
+            return null;
+        }
+
         /// <summary>
         /// Check if <paramref name="invocation"/> is a call to Type.GetEvent
         /// </summary>

ReflectionAnalyzers/Helpers/KnownSymbols/TypeType.cs

@@ -4,6 +4,7 @@ namespace ReflectionAnalyzers
 
     internal class TypeType : QualifiedType
     {
+        internal readonly QualifiedMethod GetConstructor;
         internal readonly QualifiedMethod GetEvent;
         internal readonly QualifiedMethod GetField;
         internal readonly QualifiedMethod GetMember;
@@ -14,6 +15,7 @@ internal class TypeType : QualifiedType
         internal TypeType()
             : base("System.Type")
         {
+            this.GetConstructor = new QualifiedMethod(this, nameof(this.GetConstructor));
             this.GetEvent = new QualifiedMethod(this, nameof(this.GetEvent));
             this.GetField = new QualifiedMethod(this, nameof(this.GetField));
             this.GetMember = new QualifiedMethod(this, nameof(this.GetMember));

ReflectionAnalyzers/NodeAnalzers/GetXAnalyzer.cs

@@ -156,18 +156,21 @@ explicitMemberAccess.Expression is TypeOfExpressionSyntax typeOf
             }
         }
 
-        private static GetXResult TryGetX(SyntaxNodeAnalysisContext context, out ITypeSymbol targetType, out ArgumentSyntax nameArg, out string targetName, out ISymbol target, out ArgumentSyntax flagsArg, out BindingFlags flags, out ArgumentSyntax typesArg, out IReadOnlyList<ITypeSymbol> types)
+        private static GetXResult TryGetX(SyntaxNodeAnalysisContext context, out ITypeSymbol targetType, out ArgumentSyntax nameArg, out string targetName, out ISymbol target, out ArgumentSyntax flagsArg, out BindingFlags effectiveFlags, out ArgumentSyntax typesArg, out IReadOnlyList<ITypeSymbol> types)
         {
+            nameArg = null;
+            targetName = null;
             typesArg = null;
             types = null;
             if (context.Node is InvocationExpressionSyntax candidate)
             {
-                var result = GetX.TryMatchGetEvent(candidate, context, out targetType, out nameArg, out targetName, out target, out flagsArg, out flags) ??
-                             GetX.TryMatchGetField(candidate, context, out targetType, out nameArg, out targetName, out target, out flagsArg, out flags) ??
-                             GetX.TryMatchGetMember(candidate, context, out targetType, out nameArg, out targetName, out target, out flagsArg, out flags, out typesArg, out types) ??
-                             GetX.TryMatchGetMethod(candidate, context, out targetType, out nameArg, out targetName, out target, out flagsArg, out flags, out typesArg, out types) ??
-                             GetX.TryMatchGetNestedType(candidate, context, out targetType, out nameArg, out targetName, out target, out flagsArg, out flags) ??
-                             GetX.TryMatchGetProperty(candidate, context, out targetType, out nameArg, out targetName, out target, out flagsArg, out flags);
+                var result = GetX.TryMatchGetConstructor(candidate, context, out targetType, out target, out flagsArg, out effectiveFlags, out typesArg, out types) ??
+                             GetX.TryMatchGetEvent(candidate, context, out targetType, out nameArg, out targetName, out target, out flagsArg, out effectiveFlags) ??
+                             GetX.TryMatchGetField(candidate, context, out targetType, out nameArg, out targetName, out target, out flagsArg, out effectiveFlags) ??
+                             GetX.TryMatchGetMember(candidate, context, out targetType, out nameArg, out targetName, out target, out flagsArg, out effectiveFlags, out typesArg, out types) ??
+                             GetX.TryMatchGetMethod(candidate, context, out targetType, out nameArg, out targetName, out target, out flagsArg, out effectiveFlags, out typesArg, out types) ??
+                             GetX.TryMatchGetNestedType(candidate, context, out targetType, out nameArg, out targetName, out target, out flagsArg, out effectiveFlags) ??
+                             GetX.TryMatchGetProperty(candidate, context, out targetType, out nameArg, out targetName, out target, out flagsArg, out effectiveFlags);
                 if (result != null)
                 {
                     return result.Value;
@@ -179,7 +182,7 @@ private static GetXResult TryGetX(SyntaxNodeAnalysisContext context, out ITypeSy
             targetName = null;
             target = null;
             flagsArg = null;
-            flags = BindingFlags.Default;
+            effectiveFlags = BindingFlags.Default;
             return GetXResult.Unknown;
         }
 

ValidCode/GetConstructor.cs

@@ -0,0 +1,37 @@
+namespace ValidCode
+{
+    using System;
+    using System.Reflection;
+
+    public class GetConstructor
+    {
+        public GetConstructor()
+        {
+            _ = typeof(Default).GetConstructor(BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly, null, Type.EmptyTypes, null);
+            _ = typeof(Single).GetConstructor(BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly, null, Type.EmptyTypes, null);
+            _ = typeof(Two).GetConstructor(BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly, null, new[] { typeof(int) }, null);
+            _ = typeof(Two).GetConstructor(BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly, null, new[] { typeof(double) }, null);
+        }
+        public class Default
+        {
+        }
+
+        public class Single
+        {
+            public Single()
+            {
+            }
+        }
+
+        public class Two
+        {
+            public Two(int value)
+            {
+            }
+
+            public Two(double value)
+            {
+            }
+        }
+    }
+}