Merge remote-tracking branch 'upstream/main' into copilot/fix-77001

* upstream/main: (206 commits)
  Remove bogus xlf tag (#80357)
  Fix missing type argument checks
  Add tests
  Use dotnet run file for generating compiler code (#80248)
  Only restore based on assets file changes if the actual content changed (#80341)
  make expressionbody analyzer use semanticspananalysis (#80339)
  [EnC] Use ignoreAssemblyKey: false to resolve symbol keys (#80342)
  Properly populate ExportedType metadata table in presence of extension block. (#80311)
  Propagate `params` to lambdas and local functions (#79880)
  Change 17.15 to VS 2026 preview. (#80325)
  Improve virtualproject support for older .NET SDKs (#80324)
  Update dependencies from https://github.com/dotnet/dotnet build 283666 (#80344)
  Update dependencies from https://github.com/dotnet/arcade build 20250917.6 (#80343)
  Simplifying
  Fix tests
  Fix tests
  Fix introduce variable placement in top level statements
  move to immutable types in signature help
  move to immutable types in signature help
  Fix check
  ...

Author: 333fred

.vscode/tasks.json

@@ -132,8 +132,9 @@
         "command": "dotnet",
         "type": "shell",
         "args": [
-          "pwsh",
-          "${workspaceFolder}/eng/generate-compiler-code.ps1"
+          "run",
+          "--file",
+          "${workspaceFolder}/eng/generate-compiler-code.cs"
         ],
         "problemMatcher": "$msCompile",
         "group": "build"

Directory.Packages.props

@@ -3,5 +3,5 @@
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
     <CentralPackageTransitivePinningEnabled>true</CentralPackageTransitivePinningEnabled>
   </PropertyGroup>
-  <Import Project="eng\Directory.Packages.props" />
-</Project>
+  <Import Project="eng\Packages.props" />
+</Project>

azure-pipelines-official.yml

@@ -290,13 +290,13 @@ extends:
 
         - task: MicroBuildSigningPlugin@4
           inputs:
-            signType: $(SignType)
+            signType: ${{ parameters.SignType }}
             zipSources: false
             feedSource: https://dnceng.pkgs.visualstudio.com/_packaging/MicroBuildToolset/nuget/v3/index.json
             # Set ConnectedPMEServiceName if the build is a CI build, otherwise it is not needed
             ${{ if eq(variables['Build.Reason'], 'IndividualCI') }}:
               ConnectedPMEServiceName: 248d384a-b39b-46e3-8ad5-c2c210d5e7ca
-          condition: and(succeeded(), in(variables['SignType'], 'test', 'real'))
+          condition: and(succeeded(), in('${{ parameters.SignType }}', 'test', 'real'))
 
         - download: profilingInputs
           artifact: merged mibc
@@ -324,7 +324,7 @@ extends:
                        /p:RepositoryName=$(Build.Repository.Name)
                        /p:VisualStudioDropName=$(VisualStudio.DropName)
                        /p:VSCodeOptimizationDataRoot="$(VSCodeOptimizationDataRoot)"
-                       /p:DotNetSignType=$(SignType)
+                       /p:DotNetSignType=${{ parameters.SignType }}
                        /p:DotnetPublishUsingPipelines=true
                        /p:IgnoreIbcMergeErrors=true
                        /p:GenerateSbom=true
@@ -403,7 +403,7 @@ extends:
             componentPassword: $(dn-bot-dnceng-build-e-code-full-release-e-packaging-r)
             componentBuildProjectName: internal
             sourceBranch: "$(ComponentBranchName)"
-            publishDataURI: "https://dev.azure.com/dnceng/internal/_apis/git/repositories/dotnet-roslyn/items?path=eng/config/PublishData.json&api-version=6.0"
+            publishDataURI: "https://dev.azure.com/dnceng/internal/_apis/git/repositories/dotnet-roslyn/items?path=eng/config/PublishData.json&version=$(ComponentBranchName)&api-version=6.0"
             publishDataAccessToken: "$(System.AccessToken)"
             dropPath: '$(Pipeline.Workspace)\VSSetup'
             cherryPick: ${{ parameters.VisualStudioCherryPickSHA }}

azure-pipelines-pr-validation.yml

@@ -357,7 +357,7 @@ extends:
             vsBranchName: ${{ parameters.VisualStudioBranchName }}
             titlePrefix: ${{ parameters.OptionalTitlePrefix }}
             sourceBranch: $(ComponentBranchName)
-            publishDataURI: "https://raw.githubusercontent.com/dotnet/roslyn/main/eng/config/PublishData.json"
+            publishDataURI: "https://raw.githubusercontent.com/dotnet/roslyn/$(ComponentBranchName)/eng/config/PublishData.json"
             queueSpeedometerValidation: true
             dropPath: '$(Pipeline.Workspace)\VSSetup'
             retainInsertedBuild: false

azure-pipelines.yml

@@ -465,8 +465,12 @@ stages:
       - powershell: eng/validate-rules-missing-documentation.ps1 -ci
         displayName: Validate rules missing documentation
 
-      - powershell: eng/generate-compiler-code.ps1 -test -configuration Release
+      - task: DotNetCoreCLI@2
         displayName: Generate Syntax Files
+        inputs:
+          command: 'custom'
+          custom: 'run'
+          arguments: '--file $(Build.SourcesDirectory)/eng/generate-compiler-code.cs -- -test -configuration Release'
 
       - powershell: eng/validate-code-formatting.ps1 -ci -rootDirectory $(Build.SourcesDirectory)\src -includeDirectories Compilers\CSharp\Portable\Generated\, Compilers\VisualBasic\Portable\Generated\, ExpressionEvaluator\VisualBasic\Source\ResultProvider\Generated\ 
         displayName: Validate Generated Syntax Files

docs/compilers/CSharp/Compiler Breaking Changes - DotNet 10.md

@@ -371,7 +371,7 @@ class C<extension> { } // type parameter may not be named "extension"
 
 ## Partial properties and events are now implicitly virtual and public
 
-***Introduced in Visual Studio 2022 version 17.15***
+***Introduced in Visual Studio 2026 version 18.0 preview 1***
 
 We have fixed [an inconsistency](https://github.com/dotnet/roslyn/issues/77346)
 where partial interface properties and events would not be implicitly `virtual` and `public` unlike their non-partial equivalents.
@@ -407,3 +407,30 @@ partial interface I
 
 class C : I;
 ```
+
+## Missing `ParamCollectionAttribute` is reported in more cases
+
+***Introduced in Visual Studio 2026 version 18.0***
+
+If you are compiling a `.netmodule` (note that this doesn't apply to normal DLL/EXE compilations),
+and have a lambda or a local function with a `params` collection parameter,
+and the `ParamCollectionAttribute` is not found, a compilation error is now reported
+(because the attribute now must be [emitted](https://github.com/dotnet/roslyn/issues/79752) on the synthesized method
+but the attribute type itself is not synthesized by the compiler into a `.netmodule`).
+You can work around that by defining the attribute yourself.
+
+```cs
+using System;
+using System.Collections.Generic;
+class C
+{
+    void M()
+    {
+        Func<IList<int>, int> lam = (params IList<int> xs) => xs.Count; // error if ParamCollectionAttribute does not exist
+        lam([1, 2, 3]);
+
+        int func(params IList<int> xs) => xs.Count; // error if ParamCollectionAttribute does not exist
+        func(4, 5, 6);
+    }
+}
+```

docs/contributing/Compiler Test Plan.md

@@ -9,7 +9,7 @@ This document provides guidance for thinking about language interactions and tes
 - BCL (including mono) and other customer impact
 - Determinism
 - Loading from metadata (source vs. loaded from metadata)
-- Public interface of compiler APIs (including semantic model APIs listed below):
+- Public compiler APIs (including semantic model and other APIs listed below):
     - GetDeclaredSymbol 
     - GetEnclosingSymbol 
     - GetSymbolInfo 
@@ -29,6 +29,7 @@ This document provides guidance for thinking about language interactions and tes
     - ClassifyConversion
     - GetOperation (`IOperation`)
     - GetCFG (`ControlFlowGraph`)
+    - DocumentationCommentId APIs
 - VB/F# interop
 - C++/CLI interop (particularly for metadata format changes, e.g. DIMs, static abstracts in interfaces, or generic attributes)
 - Performance and stress testing

eng/Directory.Packages.props renamed to eng/Packages.props

@@ -9,7 +9,7 @@ This file should be imported by eng/Versions.props
     <MicrosoftCodeAnalysisPackageVersion>3.11.0</MicrosoftCodeAnalysisPackageVersion>
     <MicrosoftNetCompilersToolsetPackageVersion>4.10.0-1.24061.4</MicrosoftNetCompilersToolsetPackageVersion>
     <!-- dotnet/dotnet dependencies -->
-    <SystemCommandLinePackageVersion>2.0.0-rc.2.25460.104</SystemCommandLinePackageVersion>
+    <SystemCommandLinePackageVersion>2.0.0-rc.2.25467.107</SystemCommandLinePackageVersion>
     <!-- dotnet/runtime dependencies -->
     <MicrosoftBclAsyncInterfacesPackageVersion>9.0.0</MicrosoftBclAsyncInterfacesPackageVersion>
     <MicrosoftExtensionsConfigurationPackageVersion>9.0.0</MicrosoftExtensionsConfigurationPackageVersion>
@@ -38,9 +38,9 @@ This file should be imported by eng/Versions.props
     <SystemThreadingTasksDataflowPackageVersion>9.0.0</SystemThreadingTasksDataflowPackageVersion>
     <SystemWindowsExtensionsPackageVersion>9.0.0</SystemWindowsExtensionsPackageVersion>
     <!-- dotnet/arcade dependencies -->
-    <MicrosoftDotNetArcadeSdkPackageVersion>11.0.0-beta.25458.3</MicrosoftDotNetArcadeSdkPackageVersion>
-    <MicrosoftDotNetHelixSdkPackageVersion>11.0.0-beta.25458.3</MicrosoftDotNetHelixSdkPackageVersion>
-    <MicrosoftDotNetXliffTasksPackageVersion>11.0.0-beta.25458.3</MicrosoftDotNetXliffTasksPackageVersion>
+    <MicrosoftDotNetArcadeSdkPackageVersion>11.0.0-beta.25467.6</MicrosoftDotNetArcadeSdkPackageVersion>
+    <MicrosoftDotNetHelixSdkPackageVersion>11.0.0-beta.25467.6</MicrosoftDotNetHelixSdkPackageVersion>
+    <MicrosoftDotNetXliffTasksPackageVersion>11.0.0-beta.25467.6</MicrosoftDotNetXliffTasksPackageVersion>
     <!-- dotnet/symreader dependencies -->
     <MicrosoftDiaSymReaderPackageVersion>2.0.0</MicrosoftDiaSymReaderPackageVersion>
     <!-- dotnet/roslyn-analyzers dependencies -->

eng/Version.Details.props

@@ -1,15 +1,15 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Dependencies>
-  <Source Uri="https://github.com/dotnet/dotnet" Mapping="roslyn" Sha="eac14590f69f6876d418cef9e8fdd3f44f6ef0b2" BarId="282708" />
+  <Source Uri="https://github.com/dotnet/dotnet" Mapping="roslyn" Sha="e533cfad385ba4f0ec96e35ad3d485dc13581906" BarId="283666" />
   <ProductDependencies>
     <!-- RoslynAnalyzers reference older builds of Roslyn and this is necessary for SourceBuild. -->
     <Dependency Name="Microsoft.CodeAnalysis" Version="3.11.0">
       <Uri>https://github.com/dotnet/roslyn</Uri>
       <Sha>ae1fff344d46976624e68ae17164e0607ab68b10</Sha>
     </Dependency>
-    <Dependency Name="System.CommandLine" Version="2.0.0-rc.2.25460.104">
+    <Dependency Name="System.CommandLine" Version="2.0.0-rc.2.25467.107">
       <Uri>https://github.com/dotnet/dotnet</Uri>
-      <Sha>eac14590f69f6876d418cef9e8fdd3f44f6ef0b2</Sha>
+      <Sha>e533cfad385ba4f0ec96e35ad3d485dc13581906</Sha>
     </Dependency>
     <!-- Necessary for source-build. This allows the live version of the package to be used by source-build. -->
     <Dependency Name="Microsoft.Bcl.AsyncInterfaces" Version="9.0.0">
@@ -115,13 +115,13 @@
     </Dependency>
   </ProductDependencies>
   <ToolsetDependencies>
-    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="11.0.0-beta.25458.3">
+    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="11.0.0-beta.25467.6">
       <Uri>https://github.com/dotnet/arcade</Uri>
-      <Sha>e7357d6000fb383b01fd37b972a3b55904267da7</Sha>
+      <Sha>06f338fe9a2a14ebb99d23d96818faaf2bccc663</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.DotNet.XliffTasks" Version="11.0.0-beta.25458.3">
+    <Dependency Name="Microsoft.DotNet.XliffTasks" Version="11.0.0-beta.25467.6">
       <Uri>https://github.com/dotnet/arcade</Uri>
-      <Sha>e7357d6000fb383b01fd37b972a3b55904267da7</Sha>
+      <Sha>06f338fe9a2a14ebb99d23d96818faaf2bccc663</Sha>
     </Dependency>
     <Dependency Name="Microsoft.DiaSymReader" Version="2.0.0">
       <Uri>https://github.com/dotnet/symreader</Uri>
@@ -131,9 +131,9 @@
       <Uri>https://github.com/dotnet/roslyn</Uri>
       <Sha>5d10d428050c0d6afef30a072c4ae68776621877</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.DotNet.Helix.Sdk" Version="11.0.0-beta.25458.3">
+    <Dependency Name="Microsoft.DotNet.Helix.Sdk" Version="11.0.0-beta.25467.6">
       <Uri>https://github.com/dotnet/arcade</Uri>
-      <Sha>e7357d6000fb383b01fd37b972a3b55904267da7</Sha>
+      <Sha>06f338fe9a2a14ebb99d23d96818faaf2bccc663</Sha>
     </Dependency>
     <Dependency Name="Microsoft.CodeAnalysis.NetAnalyzers" Version="10.0.0-preview.25375.1">
       <Uri>https://github.com/dotnet/roslyn-analyzers</Uri>