Attempt to move several data structures to be immutable

Directory.Packages.props

@@ -87,6 +87,7 @@
     <PackageVersion Include="NuGetValidator" version="2.1.1" />
     <PackageVersion Include="SharpZipLib" Version="1.4.2" />
     <PackageVersion Include="System.Collections" Version="$(SystemPackagesVersion)" />
+    <PackageVersion Include="System.Collections.Immutable" Version="8.0.0" />
     <PackageVersion Include="System.CommandLine" Version="$(SystemCommandLineVersion)" />
     <PackageVersion Include="System.ComponentModel.Composition" Version="$(SystemComponentModelCompositionPackageVersion)" />
     <PackageVersion Include="System.Formats.Asn1" Version="$(SystemFormatsAsn1PackageVersion)" />
@@ -190,6 +191,7 @@
       <_allowBuildFromSourcePackage Include="Microsoft.Extensions.FileSystemGlobbing" />
       <_allowBuildFromSourcePackage Include="Microsoft.Web.Xdt" />
       <_allowBuildFromSourcePackage Include="Newtonsoft.Json" />
+      <_allowBuildFromSourcePackage Include="System.Collections.Immutable" />
       <_allowBuildFromSourcePackage Include="System.CommandLine" />
       <_allowBuildFromSourcePackage Include="System.ComponentModel.Composition" />
       <_allowBuildFromSourcePackage Include="System.Formats.Asn1" />

build/Shared/IsExternalInit.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-#if !NET5_0_OR_GREATER
-
 using System.Diagnostics;
 
 namespace System.Runtime.CompilerServices;
@@ -13,5 +11,3 @@ namespace System.Runtime.CompilerServices;
 internal static class IsExternalInit
 {
 }
-
-#endif

build/Shared/SharedExtensions.cs

@@ -125,5 +125,45 @@ public static void AppendInt(this StringBuilder sb, int value)
                 divisor /= 10;
             }
         }
+
+        public static int SingleIndex<T>(this IList<T> lst, Predicate<T> isMatch)
+        {
+            var foundIndex = -1;
+
+            for (var index = 0; index < lst.Count; index++)
+            {
+                var item = lst[index];
+                if (isMatch(item))
+                {
+                    if (foundIndex != -1)
+                    {
+                        throw new InvalidOperationException();
+                    }
+
+                    foundIndex = index;
+                }
+            }
+
+            if (foundIndex == -1)
+            {
+                throw new InvalidOperationException();
+            }
+
+            return foundIndex;
+        }
+
+        public static int FirstIndex<T>(this IList<T> lst, Predicate<T> isMatch)
+        {
+            for (var index = 0; index < lst.Count; index++)
+            {
+                var item = lst[index];
+                if (isMatch(item))
+                {
+                    return index;
+                }
+            }
+
+            throw new InvalidOperationException();
+        }
     }
 }

src/NuGet.Clients/NuGet.MSSigning.Extensions/ilmerge.props

@@ -23,6 +23,7 @@
     <MergeInclude Include="$(OutputPath)NuGet.Versioning.dll"/>
     <MergeInclude Include="$(OutputPath)NuGet.Core.dll"/>
     <MergeInclude Include="$(OutputPath)NuGet.MSSigning.Extensions.dll"/>
+    <MergeInclude Include="$(OutputPath)System.Collections.Immutable.dll"/>
     <MergeInclude Include="$(OutputPath)System.Memory.dll"/>
     <MergeInclude Include="$(OutputPath)System.Numerics.Vectors.dll"/>
     <MergeInclude Include="$(OutputPath)System.Runtime.CompilerServices.Unsafe.dll"/>

src/NuGet.Clients/NuGet.PackageManagement.VisualStudio/ProjectServices/VsManagedLanguagesProjectSystemServices.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
@@ -204,9 +205,14 @@ private static string GetReferenceMetadataValue(ProjectReference reference, stri
         private static LibraryDependency ToPackageLibraryDependency(PackageReference reference, bool isCpvmEnabled)
         {
             // Get warning suppressions
-            IList<NuGetLogCode> noWarn = MSBuildStringUtility.GetNuGetLogCodes(GetReferenceMetadataValue(reference, ProjectItemProperties.NoWarn));
+            ImmutableArray<NuGetLogCode> noWarn = MSBuildStringUtility.GetNuGetLogCodes(GetReferenceMetadataValue(reference, ProjectItemProperties.NoWarn));
 
-            var dependency = new LibraryDependency(noWarn)
+            (var includeType, var suppressParent) = MSBuildRestoreUtility.GetLibraryDependencyIncludeFlags(
+                GetReferenceMetadataValue(reference, ProjectItemProperties.IncludeAssets),
+                GetReferenceMetadataValue(reference, ProjectItemProperties.ExcludeAssets),
+                GetReferenceMetadataValue(reference, ProjectItemProperties.PrivateAssets));
+
+            var dependency = new LibraryDependency()
             {
                 AutoReferenced = MSBuildStringUtility.IsTrue(GetReferenceMetadataValue(reference, ProjectItemProperties.IsImplicitlyDefined)),
                 GeneratePathProperty = MSBuildStringUtility.IsTrue(GetReferenceMetadataValue(reference, ProjectItemProperties.GeneratePathProperty)),
@@ -216,14 +222,11 @@ private static LibraryDependency ToPackageLibraryDependency(PackageReference ref
                     name: reference.Name,
                     versionRange: ToVersionRange(reference.Version, isCpvmEnabled),
                     typeConstraint: LibraryDependencyTarget.Package),
+                NoWarn = noWarn,
+                IncludeType = includeType,
+                SuppressParent = suppressParent,
             };
 
-            MSBuildRestoreUtility.ApplyIncludeFlags(
-                dependency,
-                GetReferenceMetadataValue(reference, ProjectItemProperties.IncludeAssets),
-                GetReferenceMetadataValue(reference, ProjectItemProperties.ExcludeAssets),
-                GetReferenceMetadataValue(reference, ProjectItemProperties.PrivateAssets));
-
             return dependency;
         }
 

src/NuGet.Clients/NuGet.PackageManagement.VisualStudio/Projects/LegacyPackageReferenceProject.cs

@@ -3,9 +3,11 @@
 
 using System;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Globalization;
 using System.IO;
 using System.Linq;
+using System.Runtime.InteropServices;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft;
@@ -128,7 +130,7 @@ protected override async Task<string> GetAssetsFilePathAsync(bool shouldThrow)
             return (new[] { packageSpec }, null);
         }
 
-        private Dictionary<string, CentralPackageVersion> GetCentralPackageVersions()
+        private IReadOnlyDictionary<string, CentralPackageVersion> GetCentralPackageVersions()
         {
             ThreadHelper.ThrowIfNotOnUIThread();
 
@@ -142,7 +144,6 @@ private Dictionary<string, CentralPackageVersion> GetCentralPackageVersions()
                 .ToDictionary(cpv => cpv.Name);
         }
 
-
         private CentralPackageVersion ToCentralPackageVersion(string packageId, string version)
         {
             if (string.IsNullOrEmpty(packageId))
@@ -220,7 +221,7 @@ public override async Task<bool> InstallPackageAsync(
             BuildIntegratedInstallationContext __,
             CancellationToken token)
         {
-            var dependency = new LibraryDependency(noWarn: Array.Empty<NuGetLogCode>())
+            var dependency = new LibraryDependency()
             {
                 LibraryRange = new LibraryRange(
                     name: packageId,
@@ -423,38 +424,44 @@ private async Task<PackageSpec> GetPackageSpecAsync(ISettings settings)
             var packageReferences = (await ProjectServices
                 .ReferencesReader
                 .GetPackageReferencesAsync(targetFramework, CancellationToken.None))
-                .ToList();
+                .ToImmutableArray();
 
 #pragma warning disable CS0618 // Type or member is obsolete
             // Need to validate no project systems get this property via DTE, and if so, switch to GetPropertyValue
             var packageTargetFallback = MSBuildStringUtility.Split(GetPropertySafe(_vsProjectAdapter.BuildProperties, ProjectBuildProperties.PackageTargetFallback))
                 .Select(NuGetFramework.Parse)
                 .ToList();
 
-            var assetTargetFallback = MSBuildStringUtility.Split(GetPropertySafe(_vsProjectAdapter.BuildProperties, ProjectBuildProperties.AssetTargetFallback))
+            var assetTargetFallbackList = MSBuildStringUtility.Split(GetPropertySafe(_vsProjectAdapter.BuildProperties, ProjectBuildProperties.AssetTargetFallback))
                 .Select(NuGetFramework.Parse)
                 .ToList();
 #pragma warning restore CS0618 // Type or member is obsolete
 
-            var projectTfi = new TargetFrameworkInformation
-            {
-                FrameworkName = targetFramework,
-                Dependencies = packageReferences,
-            };
-
 #pragma warning disable CS0618 // Type or member is obsolete
             // Need to validate no project systems get this property via DTE, and if so, switch to GetPropertyValue
             bool isCpvmEnabled = MSBuildStringUtility.IsTrue(GetPropertySafe(_vsProjectAdapter.BuildProperties, ProjectBuildProperties.ManagePackageVersionsCentrally));
 #pragma warning restore CS0618 // Type or member is obsolete
+
+            IReadOnlyDictionary<string, CentralPackageVersion> centralPackageVersions = null;
             if (isCpvmEnabled)
             {
                 // Add the central version information and merge the information to the package reference dependencies
-                projectTfi.CentralPackageVersions.AddRange(GetCentralPackageVersions());
-                LibraryDependency.ApplyCentralVersionInformation(projectTfi.Dependencies, projectTfi.CentralPackageVersions);
+                centralPackageVersions = GetCentralPackageVersions();
+                packageReferences = ApplyCentralVersionInformation(packageReferences, centralPackageVersions);
             }
 
-            // Apply fallback settings
-            AssetTargetFallbackUtility.ApplyFramework(projectTfi, packageTargetFallback, assetTargetFallback);
+            // Get fallback settings
+            (targetFramework, var imports, var assetTargetFallback, var warn) = AssetTargetFallbackUtility.GetFallbackFrameworkInformation(targetFramework, packageTargetFallback, assetTargetFallbackList);
+
+            var projectTfi = new TargetFrameworkInformation
+            {
+                AssetTargetFallback = assetTargetFallback,
+                CentralPackageVersions = centralPackageVersions,
+                Dependencies = packageReferences,
+                Imports = imports,
+                FrameworkName = targetFramework,
+                Warn = warn,
+            };
 
             // Build up runtime information.
 
@@ -564,6 +571,57 @@ private async Task<PackageSpec> GetPackageSpecAsync(ISettings settings)
             };
         }
 
+        internal static ImmutableArray<LibraryDependency> ApplyCentralVersionInformation(ImmutableArray<LibraryDependency> packageReferences, IReadOnlyDictionary<string, CentralPackageVersion> centralPackageVersions)
+        {
+            if (packageReferences.IsDefault)
+            {
+                throw new ArgumentNullException(nameof(packageReferences));
+            }
+            if (centralPackageVersions == null)
+            {
+                throw new ArgumentNullException(nameof(centralPackageVersions));
+            }
+            if (centralPackageVersions.Count == 0)
+            {
+                return packageReferences;
+            }
+
+            LibraryDependency[] result = new LibraryDependency[packageReferences.Length];
+            for (int i = 0; i < packageReferences.Length; i++)
+            {
+                LibraryDependency d = packageReferences[i];
+                if (!d.AutoReferenced && d.LibraryRange.VersionRange == null)
+                {
+                    var libraryRange = d.LibraryRange;
+                    var versionCentrallyManaged = d.VersionCentrallyManaged;
+
+                    if (d.VersionOverride != null)
+                    {
+                        libraryRange = new LibraryRange(d.LibraryRange) { VersionRange = d.VersionOverride };
+                    }
+                    else
+                    {
+                        if (centralPackageVersions.TryGetValue(d.Name, out CentralPackageVersion centralPackageVersion))
+                        {
+                            libraryRange = new LibraryRange(d.LibraryRange) { VersionRange = centralPackageVersion.VersionRange };
+                        }
+
+                        versionCentrallyManaged = true;
+                    }
+
+                    d = new LibraryDependency(d)
+                    {
+                        LibraryRange = libraryRange,
+                        VersionCentrallyManaged = versionCentrallyManaged
+                    };
+                }
+
+                result[i] = d;
+            }
+
+            return ImmutableCollectionsMarshal.AsImmutableArray(result);
+        }
+
         internal static IEnumerable<RuntimeDescription> GetRuntimeIdentifiers(string unparsedRuntimeIdentifer, string unparsedRuntimeIdentifers)
         {
             var runtimes = Enumerable.Empty<string>();