Merge remote-tracking branch 'dotnet/master' into...

Merge remote-tracking branch 'dotnet/master' into pr/33648-revise-nullablewalker-to-use-a-two-state-solution

.editorconfig

@@ -63,6 +63,17 @@ dotnet_naming_symbols.non_private_static_fields.required_modifiers = static
 
 dotnet_naming_style.non_private_static_field_style.capitalization = pascal_case
 
+# Non-private readonly fields are PascalCase
+dotnet_naming_rule.non_private_readonly_fields_should_be_pascal_case.severity = suggestion
+dotnet_naming_rule.non_private_readonly_fields_should_be_pascal_case.symbols = non_private_readonly_fields
+dotnet_naming_rule.non_private_readonly_fields_should_be_pascal_case.style = non_private_readonly_field_style
+
+dotnet_naming_symbols.non_private_readonly_fields.applicable_kinds = field
+dotnet_naming_symbols.non_private_readonly_fields.applicable_accessibilities = public, protected, internal, protected internal, private protected
+dotnet_naming_symbols.non_private_readonly_fields.required_modifiers = readonly
+
+dotnet_naming_style.non_private_readonly_field_style.capitalization = pascal_case
+
 # Constants are PascalCase
 dotnet_naming_rule.constants_should_be_pascal_case.severity = suggestion
 dotnet_naming_rule.constants_should_be_pascal_case.symbols = constants

Roslyn.sln

@@ -280,6 +280,7 @@ EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.VisualStudio.IntegrationTest.Setup", "src\VisualStudio\IntegrationTest\TestSetup\Microsoft.VisualStudio.IntegrationTest.Setup.csproj", "{A88AB44F-7F9D-43F6-A127-83BB65E5A7E2}"
 	ProjectSection(ProjectDependencies) = postProject
 		{600AF682-E097-407B-AD85-EE3CED37E680} = {600AF682-E097-407B-AD85-EE3CED37E680}
+		{A486D7DE-F614-409D-BB41-0FFDF582E35C} = {A486D7DE-F614-409D-BB41-0FFDF582E35C}
 	EndProjectSection
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.VisualStudio.LanguageServices.IntegrationTests", "src\VisualStudio\IntegrationTest\IntegrationTests\Microsoft.VisualStudio.LanguageServices.IntegrationTests.csproj", "{E5A55C16-A5B9-4874-9043-A5266DC02F58}"

docs/contributing/Building, Debugging, and Testing on Windows.md

@@ -11,24 +11,19 @@ Using the command line Roslyn can be developed using the following pattern:
 
 ## Recommended version of .NET Framework
 
-The minimal required version of .NET Framework is 4.6, however 4.7.2 is recommended for best developer experience.
+The minimal required version of .NET Framework is 4.7.2.
 
-The projects in this repository are configured to build with Portable PDBs, which are supported in stack traces starting with .NET Framework 4.7.2.
-If a stack trace is displayed on .NET Framework older than 4.7.2 (e.g. by xUnit when a test fails) it won't contain source and line information.
+## Developing with Visual Studio 2019
 
-.NET Framework 4.7.2 is included in [Windows 10 April 2018 Update](https://blogs.windows.com/windowsexperience/2018/04/30/how-to-get-the-windows-10-april-2018-update/). It can also be installed from the [Microsoft Download Center](https://www.microsoft.com/net/download/dotnet-framework-runtime).
-
-## Developing with Visual Studio 2017
-
-1. [Visual Studio 2017 Version 15.7](https://www.visualstudio.com/vs/preview/)
+1. [Visual Studio 2019 Preview 4](https://www.visualstudio.com/vs/preview/)
     - Ensure C#, VB, MSBuild, .NET Core and Visual Studio Extensibility are included in the selected work loads
-    - Ensure Visual Studio is on Version "15.7" or greater
+    - Ensure Visual Studio is on Version "Preview 4" or greater
 1. [.NET Core SDK 2.1.401](https://www.microsoft.com/net/download/core) (the installers are: [Windows x64 installer](https://dotnetcli.blob.core.windows.net/dotnet/Sdk/2.1.401/dotnet-sdk-2.1.401-win-x64.exe), [Windows x86 installer](https://dotnetcli.blob.core.windows.net/dotnet/Sdk/2.1.401/dotnet-sdk-2.1.401-win-x86.exe))
 1. [PowerShell 3.0 or newer](https://docs.microsoft.com/en-us/powershell/scripting/setup/installing-windows-powershell). If you are on Windows 10, you are fine; you'll only need to upgrade if you're on Windows 7. The download link is under the "upgrading existing Windows PowerShell" heading.
 1. Run Restore.cmd
 1. Open Roslyn.sln
 
-If you already installed Visual Studio and need to add the necessary work loads or move to version 15.7:
+If you already installed Visual Studio and need to add the necessary work loads or move to Preview 4:
 do the following:
 
 - Run the Visual Studio Installer from your start menu. You can just search for "Visual Studio Installer". If you can't find it, it's typically located at "C:\Program Files (x86)\Microsoft Visual Studio\Installer\vs_installer.exe"
@@ -44,7 +39,7 @@ There are a number of options for running the core Roslyn unit tests:
 
 The Test.cmd script will run our unit test on already built binaries.  It can be passed the -build arguments to force a new build before running tests.
 
-1. Run the "Developer Command Prompt for VS2017" from your start menu.
+1. Run the "Developer Command Prompt for VS2019" from your start menu.
 2. Navigate to the directory of your Git clone.
 3. Run `msbuild /v:m /m /nodereuse:false BuildAndTest.proj` in the command prompt.
 

eng/Version.Details.xml

@@ -2,9 +2,9 @@
 <Dependencies>
   <ProductDependencies></ProductDependencies>
   <ToolsetDependencies>
-    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="1.0.0-beta.19126.6">
+    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="1.0.0-beta.19127.8">
       <Uri>https://github.com/dotnet/arcade</Uri>
-      <Sha>3f38c38af31863b35c9334320b95cca56e29c942</Sha>
+      <Sha>f393a6b6b2df0854e051f314977137d31855b6c8</Sha>
     </Dependency>
   </ToolsetDependencies>
 </Dependencies>

eng/Versions.props

@@ -68,10 +68,9 @@
     <MicrosoftMetadataVisualizerVersion>1.0.0-beta1-63011-01</MicrosoftMetadataVisualizerVersion>
     <MicrosoftMSXMLVersion>8.0.0.0-alpha</MicrosoftMSXMLVersion>
     <MicrosoftNetFrameworkReferenceAssembliesVersion>1.0.0-alpha-004</MicrosoftNetFrameworkReferenceAssembliesVersion>
-    <MicrosoftNetCompilersVersion>3.0.0-beta2-19068-12</MicrosoftNetCompilersVersion>
+    <MicrosoftNetCompilersToolsetVersion>3.1.0-beta1-19127-06</MicrosoftNetCompilersToolsetVersion>
     <MicrosoftNetCoreAnalyzersVersion>$(RoslynDiagnosticsNugetPackageVersion)</MicrosoftNetCoreAnalyzersVersion>
     <MicrosoftNetCoreILAsmVersion>2.0.0</MicrosoftNetCoreILAsmVersion>
-    <MicrosoftNETCoreCompilersVersion>3.0.0-beta2-19068-12</MicrosoftNETCoreCompilersVersion>
     <MicrosoftNETCorePlatformsVersion>2.1.0</MicrosoftNETCorePlatformsVersion>
     <MicrosoftNETCoreRuntimeCoreCLRVersion>2.0.0</MicrosoftNETCoreRuntimeCoreCLRVersion>
     <!-- Using a private build of Microsoft.Net.Test.SDK to work around issue https://github.com/Microsoft/vstest/issues/1764 -->
@@ -279,10 +278,10 @@
     <UsingToolXliff>true</UsingToolXliff>
     <UsingToolXUnit>true</UsingToolXUnit>
     <!-- 
-      Use compilers in Microsoft.NET.Compilers package unless we are building with bootstrapped compilers.
-      Allows to dogfood the latest compiler features.
+       During the transition period from Microsoft.Net.Compilers to Microsoft.Net.Compilers.Toolset
+       we are always doing custom importing here.
     -->
-    <UsingToolMicrosoftNetCompilers Condition="'$(BootstrapBuildPath)' == ''">true</UsingToolMicrosoftNetCompilers>
+    <UsingToolMicrosoftNetCompilers>false</UsingToolMicrosoftNetCompilers>
   </PropertyGroup>
   <PropertyGroup>
     <RestoreSources>

eng/targets/Settings.props

@@ -130,6 +130,14 @@
   -->
   <Import Project="Bootstrap.props" Condition="'$(BootstrapBuildPath)' != ''" />
 
+  <!--
+     During the transition period from Microsoft.Net.Compilers to Microsoft.Net.Compilers.Toolset
+     we need our own PackageReference
+  -->
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Net.Compilers.Toolset" Version="$(MicrosoftNetCompilersToolsetVersion)" Condition="'$(BootstrapBuildPath)' == ''" PrivateAssets="all" IsImplicitlyDefined="true" />
+  </ItemGroup>
+
   <!--
     Analyzers
   -->
@@ -188,7 +196,7 @@
     <!-- C# specific settings -->
     <When Condition="'$(Language)' == 'C#'">
       <PropertyGroup>
-        <LangVersion>7.3</LangVersion>
+        <LangVersion>8.0</LangVersion>
         <WarningLevel>4</WarningLevel>
         <ErrorReport>prompt</ErrorReport>
 

global.json

@@ -7,6 +7,6 @@
     "xcopy-msbuild": "15.9.0-alpha"
   },
   "msbuild-sdks": {
-    "Microsoft.DotNet.Arcade.Sdk": "1.0.0-beta.19126.6"
+    "Microsoft.DotNet.Arcade.Sdk": "1.0.0-beta.19127.8"
   }
 }

src/Compilers/CSharp/Portable/FlowAnalysis/NullableWalker.cs

@@ -1337,17 +1337,19 @@ public override BoundNode VisitObjectCreationExpression(BoundObjectCreationExpre
 
             int slot = -1;
             TypeSymbol type = node.Type;
+            NullableFlowState resultState = NullableFlowState.NotNull;
             if ((object)type != null)
             {
                 bool isTrackableStructType = EmptyStructTypeCache.IsTrackableStructType(type);
+                var constructor = (node as BoundObjectCreationExpression)?.Constructor;
+                bool isDefaultValueTypeConstructor = constructor?.IsDefaultValueTypeConstructor() == true;
+
                 if (!type.IsValueType || isTrackableStructType)
                 {
                     slot = GetOrCreateObjectCreationPlaceholderSlot(node);
                     if (slot > 0 && isTrackableStructType)
                     {
                         this.State[slot] = NullableFlowState.NotNull;
-                        var constructor = (node as BoundObjectCreationExpression)?.Constructor;
-                        bool isDefaultValueTypeConstructor = constructor?.IsDefaultValueTypeConstructor() == true;
                         var tupleType = constructor?.ContainingType as TupleTypeSymbol;
                         if ((object)tupleType != null && !isDefaultValueTypeConstructor)
                         {
@@ -1364,6 +1366,11 @@ public override BoundNode VisitObjectCreationExpression(BoundObjectCreationExpre
                         }
                     }
                 }
+                else if (type.IsNullableType() && isDefaultValueTypeConstructor)
+                {
+                    // a nullable value type created with its default constructor is by definition null
+                    resultState = NullableFlowState.MaybeNull;
+                }
             }
 
             if (initializerOpt != null)
@@ -1371,7 +1378,7 @@ public override BoundNode VisitObjectCreationExpression(BoundObjectCreationExpre
                 VisitObjectCreationInitializer(null, slot, initializerOpt);
             }
 
-            ResultType = new TypeWithState(type, NullableFlowState.NotNull);
+            ResultType = new TypeWithState(type, resultState);
         }
 
         private void VisitObjectCreationInitializer(Symbol containingSymbol, int containingSlot, BoundExpression node)

src/Compilers/CSharp/Test/Semantic/Semantics/NullableReferenceTypesTests.cs

@@ -74229,8 +74229,14 @@ public void NullableT_10()
     }
 }";
             var comp = CreateCompilation(source, options: WithNonNullTypesTrue());
-            // https://github.com/dotnet/roslyn/issues/31502: Recognize Nullable<T> constructors.
-            comp.VerifyDiagnostics();
+            comp.VerifyDiagnostics(
+                // (6,13): warning CS8629: Nullable value type may be null.
+                //         _ = x.Value; // 1
+                Diagnostic(ErrorCode.WRN_NullableValueTypeMayBeNull, "x").WithLocation(6, 13),
+                // (10,13): warning CS8629: Nullable value type may be null.
+                //         _ = z.Value; // 2
+                Diagnostic(ErrorCode.WRN_NullableValueTypeMayBeNull, "z").WithLocation(10, 13)
+                );
         }
 
         [Fact]

src/Compilers/Core/Portable/Operations/ControlFlowGraphBuilder.cs

@@ -311,7 +311,7 @@ void followBranch(BasicBlockBuilder current, in BasicBlockBuilder.Branch branch)
             }
 
             // Returns whether we should proceed to the destination after finallies were taken care of.
-            bool stepThroughFinally(ControlFlowRegion region, BasicBlockBuilder destination)
+            static bool stepThroughFinally(ControlFlowRegion region, BasicBlockBuilder destination)
             {
                 int destinationOrdinal = destination.Ordinal;
                 while (!region.ContainsBlock(destinationOrdinal))

src/VisualStudio/IntegrationTest/TestUtilities/VisualStudioInstance.cs

@@ -92,6 +92,19 @@ public VisualStudioInstance(Process hostProcess, DTE dte, ImmutableHashSet<strin
             SupportedPackageIds = supportedPackageIds;
             InstallationPath = installationPath;
 
+            if (System.Diagnostics.Debugger.IsAttached)
+            {
+                // If a Visual Studio debugger is attached to the test process, attach it to the instance running
+                // integration tests as well.
+                var debuggerHostDte = GetDebuggerHostDte();
+                int targetProcessId = Process.GetCurrentProcess().Id;
+                var localProcess = debuggerHostDte?.Debugger.LocalProcesses.OfType<EnvDTE80.Process2>().FirstOrDefault(p => p.ProcessID == hostProcess.Id);
+                if (localProcess != null)
+                {
+                    localProcess.Attach2("Managed");
+                }
+            }
+
             StartRemoteIntegrationService(dte);
 
             _integrationServiceChannel = new IpcClientChannel(GetIpcClientChannelName(HostProcess), sinkProvider: null);
@@ -239,6 +252,21 @@ public void Close(bool exitHostProcess = true)
             }
         }
 
+        private static DTE GetDebuggerHostDte()
+        {
+            var currentProcessId = Process.GetCurrentProcess().Id;
+            foreach (var process in Process.GetProcessesByName("devenv"))
+            {
+                var dte = IntegrationHelper.TryLocateDteForProcess(process);
+                if (dte?.Debugger?.DebuggedProcesses?.OfType<EnvDTE.Process>().Any(p => p.ProcessID == currentProcessId) ?? false)
+                {
+                    return dte;
+                }
+            }
+
+            return null;
+        }
+
         private void CloseHostProcess()
         {
             _inProc.Quit();