Add LangVersion 7.2 for C# (#19846)

docs/compilers/CSharp/CommandLine.md

@@ -50,7 +50,7 @@
 | `/checked`{`+`|`-`} | Generate overflow checks
 | `/unsafe`{`+`|`-`} | Allow 'unsafe' code
 | `/define:`*symbol list* | Define conditional compilation symbol(s) (Short form: `/d`)
-| `/langversion`:*string* | Specify language version mode: `ISO-1`, `ISO-2`, `3`, `4`, `5`, `6`, `7`, `7.1`, `Default` (latest major version), or `Latest` (latest version, including minor versions)
+| `/langversion`:*string* | Specify language version mode: `ISO-1`, `ISO-2`, `3`, `4`, `5`, `6`, `7`, `7.1`, `7.2`, `Default` (latest major version), or `Latest` (latest version, including minor versions)
 | **SECURITY**
 | `/delaysign`{`+`|`-`} | Delay-sign the assembly using only the public portion of the strong name key
 | `/keyfile:`*file* | Specify a strong name key file

src/Compilers/CSharp/Portable/CSharpResources.resx

@@ -2705,7 +2705,7 @@ A catch() block after a catch (System.Exception e) block can catch non-CLS excep
     <value>This warning occurs if the assembly attributes AssemblyKeyFileAttribute or AssemblyKeyNameAttribute found in source conflict with the /keyfile or /keycontainer command line option or key file name or key container specified in the Project Properties.</value>
   </data>
   <data name="ERR_BadCompatMode" xml:space="preserve">
-    <value>Invalid option '{0}' for /langversion; must be ISO-1, ISO-2, Default, Latest or a valid version in range 1 to 7.1.</value>
+    <value>Invalid option '{0}' for /langversion; must be ISO-1, ISO-2, Default, Latest or a valid version in range 1 to 7.2.</value>
   </data>
   <data name="ERR_DelegateOnConditional" xml:space="preserve">
     <value>Cannot create delegate with '{0}' because it or a method it overrides has a Conditional attribute</value>
@@ -4472,7 +4472,7 @@ To remove the warning, you can use /reference instead (set the Embed Interop Typ
  /define:&lt;symbol list&gt;         Define conditional compilation symbol(s) (Short
                                form: /d)
  /langversion:&lt;string&gt;         Specify language version mode: ISO-1, ISO-2, 3,
-                               4, 5, 6, 7.0, 7.1, Default, or Latest
+                               4, 5, 6, 7.0, 7.1, 7.2, Default, or Latest
 
                         - SECURITY -
  /delaysign[+|-]               Delay-sign the assembly using only the public
@@ -5048,6 +5048,9 @@ To remove the warning, you can use /reference instead (set the Embed Interop Typ
   <data name="ERR_FeatureNotAvailableInVersion7_1" xml:space="preserve">
     <value>Feature '{0}' is not available in C# 7.1. Please use language version {1} or greater.</value>
   </data>
+  <data name="ERR_FeatureNotAvailableInVersion7_2" xml:space="preserve">
+    <value>Feature '{0}' is not available in C# 7.2. Please use language version {1} or greater.</value>
+  </data>
   <data name="ERR_LanguageVersionCannotHaveLeadingZeroes" xml:space="preserve">
     <value>Specified language version '{0}' cannot have leading zeroes</value>
   </data>

src/Compilers/CSharp/Portable/Errors/ErrorCode.cs

@@ -1488,5 +1488,9 @@ internal enum ErrorCode
         ERR_PatternWrongGenericTypeInVersion = 8314,
 
         #endregion diagnostics introduced for C# 7.1
+
+        #region diagnostics introduced for C# 7.2
+        ERR_FeatureNotAvailableInVersion7_2 = 8320,
+        #endregion diagnostics introduced for C# 7.2
     }
 }

src/Compilers/CSharp/Portable/LanguageVersion.cs

@@ -74,6 +74,11 @@ public enum LanguageVersion
         /// </summary>
         CSharp7_1 = 701,
 
+        /// <summary>
+        /// C# language version 7.2
+        /// </summary>
+        CSharp7_2 = 702,
+
         /// <summary>
         /// The latest version of the language supported.
         /// </summary>
@@ -94,6 +99,7 @@ internal static bool IsValid(this LanguageVersion value)
                 case LanguageVersion.CSharp6:
                 case LanguageVersion.CSharp7:
                 case LanguageVersion.CSharp7_1:
+                case LanguageVersion.CSharp7_2:
                     return true;
             }
 
@@ -120,6 +126,8 @@ internal static ErrorCode GetErrorCode(this LanguageVersion version)
                     return ErrorCode.ERR_FeatureNotAvailableInVersion7;
                 case LanguageVersion.CSharp7_1:
                     return ErrorCode.ERR_FeatureNotAvailableInVersion7_1;
+                case LanguageVersion.CSharp7_2:
+                    return ErrorCode.ERR_FeatureNotAvailableInVersion7_2;
                 default:
                     throw ExceptionUtilities.UnexpectedValue(version);
             }
@@ -164,6 +172,8 @@ public static string ToDisplayString(this LanguageVersion version)
                     return "7.0";
                 case LanguageVersion.CSharp7_1:
                     return "7.1";
+                case LanguageVersion.CSharp7_2:
+                    return "7.2";
                 case LanguageVersion.Default:
                     return "default";
                 case LanguageVersion.Latest:
@@ -235,6 +245,10 @@ public static bool TryParse(this string version, out LanguageVersion result)
                     result = LanguageVersion.CSharp7_1;
                     return true;
 
+                case "7.2":
+                    result = LanguageVersion.CSharp7_2;
+                    return true;
+
                 default:
                     result = LanguageVersion.Default;
                     return false;
@@ -249,7 +263,7 @@ public static LanguageVersion MapSpecifiedToEffectiveVersion(this LanguageVersio
             switch (version)
             {
                 case LanguageVersion.Latest:
-                    return LanguageVersion.CSharp7_1;
+                    return LanguageVersion.CSharp7_2;
                 case LanguageVersion.Default:
                     return LanguageVersion.CSharp7;
                 default:

src/Compilers/CSharp/Portable/PublicAPI.Unshipped.txt

@@ -1,4 +1,5 @@
 Microsoft.CodeAnalysis.CSharp.LanguageVersion.CSharp7_1 = 701 -> Microsoft.CodeAnalysis.CSharp.LanguageVersion
+Microsoft.CodeAnalysis.CSharp.LanguageVersion.CSharp7_2 = 702 -> Microsoft.CodeAnalysis.CSharp.LanguageVersion
 Microsoft.CodeAnalysis.CSharp.LanguageVersionFacts
 Microsoft.CodeAnalysis.CSharp.SyntaxKind.ConflictMarkerTrivia = 8564 -> Microsoft.CodeAnalysis.CSharp.SyntaxKind
 Microsoft.CodeAnalysis.CSharp.SyntaxKind.DefaultLiteralExpression = 8755 -> Microsoft.CodeAnalysis.CSharp.SyntaxKind

src/Compilers/CSharp/Test/CommandLine/CommandLineTests.cs

@@ -1304,7 +1304,7 @@ public void LanguageVersionAdded_Canary()
             // - update the IDE drop-down for selecting Language Version
             // - update all the tests that call this canary
             // - update the command-line documentation (CommandLine.md)
-            AssertEx.SetEqual(new[] { "default", "1", "2", "3", "4", "5", "6", "7.0", "7.1", "latest" },
+            AssertEx.SetEqual(new[] { "default", "1", "2", "3", "4", "5", "6", "7.0", "7.1", "7.2", "latest" },
                 Enum.GetValues(typeof(LanguageVersion)).Cast<LanguageVersion>().Select(v => v.ToDisplayString()));
             // For minor versions, the format should be "x.y", such as "7.1"
         }
@@ -1325,7 +1325,8 @@ public void LanguageVersion_GetErrorCode()
                 ErrorCode.ERR_FeatureNotAvailableInVersion5,
                 ErrorCode.ERR_FeatureNotAvailableInVersion6,
                 ErrorCode.ERR_FeatureNotAvailableInVersion7,
-                ErrorCode.ERR_FeatureNotAvailableInVersion7_1
+                ErrorCode.ERR_FeatureNotAvailableInVersion7_1,
+                ErrorCode.ERR_FeatureNotAvailableInVersion7_2
             };
 
             AssertEx.SetEqual(versions, errorCodes);
@@ -1345,9 +1346,10 @@ public void LanguageVersion_MapSpecifiedToEffectiveVersion()
             Assert.Equal(LanguageVersion.CSharp6, LanguageVersion.CSharp6.MapSpecifiedToEffectiveVersion());
             Assert.Equal(LanguageVersion.CSharp7, LanguageVersion.CSharp7.MapSpecifiedToEffectiveVersion());
             Assert.Equal(LanguageVersion.CSharp7_1, LanguageVersion.CSharp7_1.MapSpecifiedToEffectiveVersion());
+            Assert.Equal(LanguageVersion.CSharp7_2, LanguageVersion.CSharp7_2.MapSpecifiedToEffectiveVersion());
 
             Assert.Equal(LanguageVersion.CSharp7, LanguageVersion.Default.MapSpecifiedToEffectiveVersion());
-            Assert.Equal(LanguageVersion.CSharp7_1, LanguageVersion.Latest.MapSpecifiedToEffectiveVersion());
+            Assert.Equal(LanguageVersion.CSharp7_2, LanguageVersion.Latest.MapSpecifiedToEffectiveVersion());
 
             // The canary check is a reminder that this test needs to be updated when a language version is added
             LanguageVersionAdded_Canary();
@@ -1374,6 +1376,7 @@ public void LanguageVersion_MapSpecifiedToEffectiveVersion()
             InlineData("7.0", true, LanguageVersion.CSharp7),
             InlineData("07", false, LanguageVersion.Default),
             InlineData("7.1", true, LanguageVersion.CSharp7_1),
+            InlineData("7.2", true, LanguageVersion.CSharp7_2),
             InlineData("07.1", false, LanguageVersion.Default),
             InlineData("default", true, LanguageVersion.Default),
             InlineData("latest", true, LanguageVersion.Latest),

src/EditorFeatures/CSharpTest/Diagnostics/UpgradeProject/UpgradeProjectTests.cs

@@ -11,6 +11,7 @@
 
 namespace Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.Diagnostics.Async
 {
+    [Trait(Traits.Feature, Traits.Features.CodeActionsUpgradeProject)]
     public partial class UpgradeProjectTests : AbstractCSharpDiagnosticProviderBasedUserDiagnosticTest
     {
         internal override (DiagnosticAnalyzer, CodeFixProvider) CreateDiagnosticProviderAndFixer(Workspace workspace)
@@ -38,7 +39,7 @@ private async Task TestLanguageVersionUpgradedAsync(
             await TestAsync(initialMarkup, initialMarkup, parseOptions); // no change to markup
         }
 
-        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUpgradeProject)]
+        [Fact]
         public async Task UpgradeProjectFromCSharp6ToDefault()
         {
             await TestLanguageVersionUpgradedAsync(
@@ -54,7 +55,7 @@ void A()
                 new CSharpParseOptions(LanguageVersion.CSharp6));
         }
 
-        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUpgradeProject)]
+        [Fact]
         public async Task UpgradeProjectFromCSharp6ToCSharp7()
         {
             await TestLanguageVersionUpgradedAsync(
@@ -71,7 +72,7 @@ void A()
                 index: 1);
         }
 
-        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUpgradeProject)]
+        [Fact]
         public async Task UpgradeProjectFromCSharp5ToCSharp6()
         {
             await TestLanguageVersionUpgradedAsync(
@@ -88,7 +89,7 @@ void A()
                 index: 1);
         }
 
-        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUpgradeProject)]
+        [Fact]
         public async Task UpgradeProjectFromCSharp4ToCSharp5()
         {
             await TestLanguageVersionUpgradedAsync(
@@ -105,7 +106,7 @@ void A()
                 index: 1);
         }
 
-        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUpgradeProject)]
+        [Fact]
         public async Task UpgradeProjectFromCSharp7ToLatest()
         {
             await TestLanguageVersionUpgradedAsync(
@@ -118,7 +119,7 @@ class Program
                 new CSharpParseOptions(LanguageVersion.CSharp7));
         }
 
-        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUpgradeProject)]
+        [Fact]
         public async Task UpgradeProjectFromCSharp7ToLatest_TriggeredByInferredTupleNames()
         {
             await TestLanguageVersionUpgradedAsync(
@@ -152,7 +153,7 @@ public ValueTuple(T1 item1, T2 item2)
                 new CSharpParseOptions(LanguageVersion.CSharp7));
         }
 
-        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUpgradeProject)]
+        [Fact]
         public async Task UpgradeProjectFromCSharp7_1ToLatest()
         {
             await TestLanguageVersionUpgradedAsync(
@@ -165,7 +166,20 @@ class Program
                 new CSharpParseOptions(LanguageVersion.CSharp7_1));
         }
 
-        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUpgradeProject)]
+        [Fact]
+        public async Task UpgradeProjectFromCSharp7_2ToLatest()
+        {
+            await TestLanguageVersionUpgradedAsync(
+@"
+class Program
+{
+#error version:[|7.2|]
+}",
+                LanguageVersion.Latest,
+                new CSharpParseOptions(LanguageVersion.CSharp7_2));
+        }
+
+        [Fact]
         public async Task UpgradeProjectFromCSharp7ToCSharp7_1()
         {
             await TestLanguageVersionUpgradedAsync(
@@ -179,7 +193,7 @@ class Program
                 index: 1);
         }
 
-        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUpgradeProject)]
+        [Fact]
         public async Task UpgradeProjectFromCSharp7ToCSharp7_1_B()
         {
             await TestLanguageVersionUpgradedAsync(
@@ -198,7 +212,7 @@ public static void M<T>(T x) where T: Base
                 index: 1);
         }
 
-        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUpgradeProject)]
+        [Fact]
         public async Task UpgradeAllProjectsToDefault()
         {
             await TestLanguageVersionUpgradedAsync(
@@ -229,7 +243,7 @@ void A()
 
         }
 
-        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUpgradeProject)]
+        [Fact]
         public async Task UpgradeAllProjectsToCSharp7()
         {
             await TestLanguageVersionUpgradedAsync(
@@ -259,7 +273,7 @@ void A()
                 index: 2);
         }
 
-        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUpgradeProject)]
+        [Fact]
         public async Task ListAllSuggestions()
         {
             await TestExactActionSetOfferedAsync(
@@ -289,7 +303,7 @@ void A()
     });
         }
 
-        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUpgradeProject)]
+        [Fact]
         public async Task FixAllProjectsNotOffered()
         {
             await TestExactActionSetOfferedAsync(
@@ -315,7 +329,7 @@ void A()
                     });
         }
 
-        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUpgradeProject)]
+        [Fact]
         public async Task OnlyOfferFixAllProjectsToCSharp7WhenApplicable()
         {
             await TestExactActionSetOfferedAsync(
@@ -344,7 +358,7 @@ void A()
                     });
         }
 
-        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsUpgradeProject)]
+        [Fact]
         public async Task OnlyOfferFixAllProjectsToDefaultWhenApplicable()
         {
             await TestExactActionSetOfferedAsync(

src/Features/CSharp/Portable/UpgradeProject/CSharpUpgradeProjectCodeFixProvider.cs

@@ -26,9 +26,10 @@ internal class CSharpUpgradeProjectCodeFixProvider : AbstractUpgradeProjectCodeF
         private const string CS8302 = nameof(CS8302); // error CS8302: Feature is not available in C# 7.1. Please use language version X or greater.
         private const string CS8306 = nameof(CS8306); // error CS8306: ... Please use language version 7.1 or greater to access a un-named element by its inferred name.
         private const string CS8314 = nameof(CS8314); // error CS9003: An expression of type '{0}' cannot be handled by a pattern of type '{1}' in C# {2}. Please use language version {3} or greater.
+        private const string CS8320 = nameof(CS8320); // error CS8320: Feature is not available in C# 7.2. Please use language version X or greater.
 
         public override ImmutableArray<string> FixableDiagnosticIds { get; } =
-            ImmutableArray.Create(CS8022, CS8023, CS8024, CS8025, CS8026, CS8059, CS8107, CS8302, CS8306, CS8314);
+            ImmutableArray.Create(CS8022, CS8023, CS8024, CS8025, CS8026, CS8059, CS8107, CS8302, CS8306, CS8314, CS8320);
 
         public override string UpgradeThisProjectResource => CSharpFeaturesResources.Upgrade_this_project_to_csharp_language_version_0;
         public override string UpgradeAllProjectsResource => CSharpFeaturesResources.Upgrade_all_csharp_projects_to_language_version_0;