Exclude attributes from precondition visibility verification

Foxtrot/Foxtrot/Checker/VisibilityHelper.cs

@@ -12,6 +12,7 @@
 // 
 // THE SOFTWARE IS PROVIDED *AS IS*, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
+using System;
 using System.Compiler;
 using System.Diagnostics.Contracts;
 
@@ -23,6 +24,9 @@ namespace Microsoft.Contracts.Foxtrot
     [ContractVerification(true)]
     internal class VisibilityHelper : InspectorIncludingClosures
     {
+        private static readonly Lazy<TypeNode> systemAttributeType = new Lazy<TypeNode>(() =>
+                HelperMethods.FindType(SystemTypes.SystemAssembly, StandardIds.System, Identifier.For("Attribute")));
+
         private Member memberInErrorFound;
 
         /// <summary>
@@ -37,6 +41,22 @@ private void ReInitialize(Method asThisMember)
             this.AsThisMember = asThisMember;
         }
 
+        private static bool IsAttribute(TypeNode declaringType)
+        {
+            var currentType = declaringType;
+            while (currentType != null)
+            {
+                if (currentType == systemAttributeType.Value)
+                {
+                    return true;
+                }
+
+                currentType = currentType.BaseType;
+            }
+
+            return false;
+        }
+
         /// <summary>
         /// Checks for less-than-visible member references in an expression.
         /// </summary>
@@ -47,6 +67,11 @@ public override void VisitMemberBinding(MemberBinding binding)
             Member mem = binding.BoundMember;
             if (mem != null)
             {
+                // Member visiting includes also all attributes for the method.
+                // But from Code Contracts perspective public method can have less visible attributes
+                // because they're not part of the precondition.
+                if (IsAttribute(mem.DeclaringType)) return;
+
                 Field f = mem as Field;
                 bool specPublic = false;
 

Foxtrot/Tests/RewriterTests.cs

@@ -95,6 +95,31 @@ public static IEnumerable<object> AsyncTests
             }
         }
 
+        public static IEnumerable<object> PreconditionVisibilityTests
+        {
+            get
+            {
+                return Enumerable.Range(0, PreconditionVisibilityTestData.Count()).Select(i => new object[] { i });
+            }
+        }
+
+        private static IEnumerable<Options> PreconditionVisibilityTestData
+        {
+            get
+            {
+                yield return new Options(
+                    sourceFile: @"Foxtrot\Tests\Sources\AttributesAndPreconditions.cs",
+                    foxtrotOptions: @"",
+                    useContractReferenceAssemblies: true,
+                    compilerOptions: null,
+                    references: new string[0],
+                    libPaths: new[] {@"Microsoft.Research\RegressionTest\ClousotTestHarness\bin\debug"},
+                    compilerCode: "CS",
+                    useBinDir: false,
+                    useExe: true,
+                    mustSucceed: true);
+            }
+        }
 
         private static IEnumerable<Options> AsyncPostconditionsData
         {
@@ -2021,6 +2046,19 @@ public void BuildRewriteRunRoslynTestCasesWithV45(int testIndex)
             options.UseTestHarness = true;
             TestDriver.BuildRewriteRun(_testOutputHelper, options);
         }
+
+        [Theory]
+        [MemberData("PreconditionVisibilityTests")]
+        [Trait("Category", "Runtime"), Trait("Category", "CoreTest"), Trait("Category", "V4.5")]
+        public void PreconditionVisibilityTests45(int testIndex)
+        {
+            Options options = PreconditionVisibilityTestData.ElementAt(testIndex);
+            options.FoxtrotOptions = options.FoxtrotOptions + String.Format(" /throwonfailure /rw:{0}.exe,TestInfrastructure.RewriterMethods", Path.GetFileNameWithoutExtension(options.TestName));
+            options.BuildFramework = @".NETFramework\v4.5";
+            options.ContractFramework = @".NETFramework\v4.0";
+            options.UseTestHarness = true;
+            TestDriver.BuildRewriteRun(_testOutputHelper, options);
+        }
 
         [Theory(Skip = "Old Roslyn bits are not compatible with CCRewrite. Test (and old binaries) should be removed in the next iteration.")]
         [MemberData("TestFile")]

Foxtrot/Tests/Sources/AttributesAndPreconditions.cs

@@ -0,0 +1,51 @@
+// CodeContracts
+// 
+// Copyright (c) Microsoft Corporation
+// 
+// All rights reserved. 
+// 
+// MIT License
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED *AS IS*, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Diagnostics.Contracts;
+using System.Threading;
+
+namespace Tests.Sources
+{
+    internal class MyAttr : Attribute { }
+
+    public class Foo
+    {
+        public static void Method1([MyAttr] string s)
+        {
+            // If ccrewrite behaves properly, this method should not fail
+            Contract.Requires(s.StartsWith("foo"));
+        }
+    }
+
+    partial class TestMain
+    {
+        partial void Run()
+        {
+            if (behave)
+            {
+                Foo.Method1("foo");
+            }
+            else
+            {
+                throw new ArgumentNullException();
+            }
+        }
+
+        public ContractFailureKind NegativeExpectedKind = ContractFailureKind.Precondition;
+        public string NegativeExpectedCondition = "Value cannot be null.";
+    }
+}