Add MemberNotNull/When attributes (#33567)

* Add MemberNotNull/When attributes * Apply [CLSCompliant(false)] * Fix typos and indent * Move [CLSCompliant(false)] and remove AllowMultiple * Declare attributes in ref file * Store parameters into readonly properties * Don't use deconstruction * Qualify, move properties, remove this
dotnet · Mar 19, 2020 · 90ab57c · 90ab57c
1 parent f80a514
commit 90ab57c
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diff --git a/...ibraries/System.Private.CoreLib/src/System/Diagnostics/CodeAnalysis/NullableAttributes.cs b/...ibraries/System.Private.CoreLib/src/System/Diagnostics/CodeAnalysis/NullableAttributes.cs
@@ -125,4 +125,55 @@ sealed class DoesNotReturnIfAttribute : Attribute
         /// <summary>Gets the condition parameter value.</summary>
         public bool ParameterValue { get; }
     }
+
+    /// <summary>Specifies that the method or property will ensure that the listed field and property members have not-null values.</summary>
+    [AttributeUsage(AttributeTargets.Method | AttributeTargets.Property, Inherited = false)]
+#if INTERNAL_NULLABLE_ATTRIBUTES
+    internal
+#else
+    [CLSCompliant(false)]
+    public
+#endif
+        sealed class MemberNotNullAttribute : Attribute
+    {
+        /// <summary>Initializes the attribute with the list of field and property members.</summary>
+        /// <param name="members">
+        /// The list of field and property members that are promised to be not-null.
+        /// </param>
+        public MemberNotNullAttribute(params string[] members)
+            => Members = members;
+
+        /// <summary>Gets field or property member names.</summary>
+        public string[] Members { get; }
+    }
+
+    /// <summary>Specifies that the method or property will ensure that the listed field and property members have not-null values when returning with the specified return value condition.</summary>
+    [AttributeUsage(AttributeTargets.Method | AttributeTargets.Property, Inherited = false)]
+#if INTERNAL_NULLABLE_ATTRIBUTES
+    internal
+#else
+    [CLSCompliant(false)]
+    public
+#endif
+        sealed class MemberNotNullWhenAttribute : Attribute
+    {
+        /// <summary>Initializes the attribute with the specified return value condition and list of field and property members.</summary>
+        /// <param name="returnValue">
+        /// The return value condition. If the method returns this value, the associated parameter will not be null.
+        /// </param>
+        /// <param name="members">
+        /// The list of field and property members that are promised to be not-null.
+        /// </param>
+        public MemberNotNullWhenAttribute(bool returnValue, params string[] members)
+        {
+            ReturnValue = returnValue;
+            Members = members;
+        }
+
+        /// <summary>Gets the return value condition.</summary>
+        public bool ReturnValue { get; }
+
+        /// <summary>Gets field or property member names.</summary>
+        public string[] Members { get; }
+    }
 }
diff --git a/src/libraries/System.Runtime/ref/System.Runtime.cs b/src/libraries/System.Runtime/ref/System.Runtime.cs
@@ -5618,6 +5618,21 @@ public sealed partial class NotNullWhenAttribute : System.Attribute
         public NotNullWhenAttribute(bool returnValue) { }
         public bool ReturnValue { get { throw null; } }
     }
+    [System.AttributeUsage(System.AttributeTargets.Method | System.AttributeTargets.Property, Inherited = false)]
+    [System.CLSCompliant(false)]
+    public sealed class MemberNotNullAttribute : System.Attribute
+    {
+        public MemberNotNullAttribute(params string[] members) { }
+        public string[] Members { get { throw null; } }
+    }
+    [System.AttributeUsage(System.AttributeTargets.Method | System.AttributeTargets.Property, Inherited = false)]
+    [System.CLSCompliant(false)]
+    public sealed class MemberNotNullWhenAttribute : System.Attribute
+    {
+        public MemberNotNullWhenAttribute(bool returnValue, params string[] members) { }
+        public bool ReturnValue { get { throw null; } }
+        public string[] Members { get { throw null; } }
+    }
     [System.AttributeUsageAttribute(System.AttributeTargets.All, Inherited=false, AllowMultiple=true)]
     [System.Diagnostics.ConditionalAttribute("CODE_ANALYSIS")]
     public sealed partial class SuppressMessageAttribute : System.Attribute