Add GenerateRuntimeGraph task

This task can be used to generate the RID heirarchy of a runtime.json from a simpler set of inputs.

src/Microsoft.DotNet.Build.Tasks.Packaging/src/Extensions.cs

@@ -20,6 +20,12 @@ public static class Extensions
     {
         private static readonly NuGetFramework NullFramework = new NuGetFramework("Null,Version=v1.0");
 
+        public static string GetString(this ITaskItem taskItem, string metadataName)
+        {
+            var metadataValue = taskItem.GetMetadata(metadataName)?.Trim();
+            return String.IsNullOrEmpty(metadataValue) ? null : metadataValue;
+        }
+
         public static bool GetBoolean(this ITaskItem taskItem, string metadataName, bool defaultValue = false)
         {
             bool result = false;
@@ -87,6 +93,17 @@ public static IReadOnlyList<string> GetValueList(this ITaskItem taskItem, string
             return null;
         }
 
+        public static IEnumerable<string> GetStrings(this ITaskItem taskItem, string metadataName)
+        {
+            var metadataValue = taskItem.GetMetadata(metadataName)?.Trim();
+            if (!string.IsNullOrEmpty(metadataValue))
+            {
+                return metadataValue.Split(';').Where(v => !String.IsNullOrEmpty(v.Trim())).ToArray();
+            }
+
+            return Enumerable.Empty<string>();
+        }
+
         public static IEnumerable<T> NullAsEmpty<T>(this IEnumerable<T> source)
         {
             if (source == null)

src/Microsoft.DotNet.Build.Tasks.Packaging/src/GenerateRuntimeGraph.cs

@@ -0,0 +1,342 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.Build.Framework;
+using Newtonsoft.Json;
+using NuGet.RuntimeModel;
+using NuGet.Versioning;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+
+namespace Microsoft.DotNet.Build.Tasks.Packaging
+{
+    public class GenerateRuntimeGraph : PackagingTask
+    {
+
+        /// <summary>
+        /// A set of RuntimeGroups that can be used to generate a runtime graph
+        ///   Identity: the base string for the RID, without version architecture, or qualifiers.
+        ///   Parent: the base string for the parent of this RID.  This RID will be imported by the baseRID, architecture-specific, 
+        ///     and qualifier-specific RIDs (with the latter two appending appropriate architecture and qualifiers).
+        ///   Versions: A list of strings delimited by semi-colons that represent the versions for this RID.
+        ///   TreatVersionsAsCompatible: Default is true.  When true, version-specific RIDs will import the previous 
+        ///     version-specific RID in the Versions list, with the first version importing the version-less RID.  
+        ///     When false all version-specific RIDs will import the version-less RID (bypassing previous version-specific RIDs)
+        ///   OmitVersionDelimiter: Default is false.  When true no characters will separate the base RID and version (EG: win7).
+        ///     When false a '.' will separate the base RID and version (EG: osx.10.12).
+        ///   ApplyVersionsToParent: Default is false.  When true, version-specific RIDs will import version-specific Parent RIDs
+        ///     similar to is done for architecture and qualifier (see Parent above).
+        ///   Architectures: A list of strings delimited by semi-colons that represent the architectures for this RID.
+        ///   AdditionalQualifiers: A list of strings delimited by semi-colons that represent the additional qualifiers for this RID.
+        ///     Additional qualifers do not stack, each only applies to the qualifier-less RIDs (so as not to cause combinatorial 
+        ///     exponential growth of RIDs).
+        ///   OmitRIDs: A list of strings delimited by semi-colons that represent RIDs calculated from this RuntimeGroup that should
+        ///     be omitted from the RuntimeGraph.  This is useful in cases where overlapping RuntimeGroups are used and one is 
+        ///     designated to be "best" for some set of calculated RIDs, the others may omit the overlapping RIDs.
+        /// </summary>
+        [Required]
+        public ITaskItem[] RuntimeGroups
+        {
+            get;
+            set;
+        }
+
+        /// <summary>
+        /// A set of QualifierPolicies that can be used to define the ordering of qualifer-specific RIDs in imports.
+        ///   Identity: the qualifier name.  This should match what is used in RuntimeGroups.AdditionalQualifiers
+        ///   VersionPrecedence: default is false.  When set to true, a qualifier-specific RID should import the 
+        ///     qualifier-less RID before any other RIDs that are not of the same version.  When false, the qualifier-
+        ///     less RID should be imported after all qualifier specific RIDs.
+        ///     
+        ///     Given the RID of  foo.1.0-x64 : [ foo.1.0, foo.0.8-x64 ]
+        ///     Applying the qualifier "bar" the following is the result for each value of VersionPrecedence:
+        ///       True: foo.1.0-x64-bar : [ foo.1.0-bar, foo.1.0-x64, foo.0.8-x64-bar ]
+        ///       False: foo.1.0-x64-bar : [ foo.1.0-bar, foo.0.8-x64-bar, foo.1.0-x64 ]
+        /// </summary>
+        public ITaskItem[] QualifierPolicies
+        {
+            get;
+            set;
+        }
+
+
+        /// <summary>
+        /// Optional source Runtime.json to use as a starting point when merging additional RuntimeGroups
+        /// </summary>
+        public ITaskItem SourceRuntimeJson
+        {
+            get;
+            set;
+        }
+
+        /// <summary>
+        /// Where to write the final runtime.json
+        /// </summary>
+        [Required]
+        public ITaskItem RuntimeJson
+        {
+            get;
+            set;
+        }
+
+        private Dictionary<string, QualifierPolicy> qualifierPolicies = new Dictionary<string, QualifierPolicy>();
+
+        public override bool Execute()
+        {
+
+            if (RuntimeJson == null)
+            {
+                Log.LogError($"{nameof(RuntimeJson)} argument must be specified");
+                return false;
+            }
+
+            RuntimeGraph runtimeGraph;
+            if (SourceRuntimeJson != null)
+            {
+                var sourceRuntimeFilePath = SourceRuntimeJson.GetMetadata("FullPath");
+
+                if (!File.Exists(sourceRuntimeFilePath))
+                {
+                    Log.LogError($"{nameof(SourceRuntimeJson)} did not exist at {sourceRuntimeFilePath}.");
+                    return false;
+                }
+
+                runtimeGraph = JsonRuntimeFormat.ReadRuntimeGraph(sourceRuntimeFilePath);
+            }
+            else
+            {
+                runtimeGraph = new RuntimeGraph();
+            }
+
+            foreach(var qualifierPolicy in QualifierPolicies.NullAsEmpty().Select(i => new QualifierPolicy(i)))
+            {
+                qualifierPolicies[qualifierPolicy.Qualifier] = qualifierPolicy;
+            }
+
+            foreach(var runtimeGroup in RuntimeGroups.NullAsEmpty().Select(i => new RuntimeGroup(i)))
+            {
+                runtimeGraph = SafeMerge(runtimeGraph, runtimeGroup);
+            }
+
+            ValidateImports(runtimeGraph);
+
+            JsonRuntimeFormat.WriteRuntimeGraph(RuntimeJson.ItemSpec, runtimeGraph);
+
+            return !Log.HasLoggedErrors;
+        }
+
+
+        private RuntimeGraph SafeMerge(RuntimeGraph existingGraph, RuntimeGroup runtimeGroup)
+        {
+            var runtimeGraph = runtimeGroup.GetRuntimeGraph(qualifierPolicies);
+
+            foreach (var existingRuntimeDescription in existingGraph.Runtimes.Values)
+            {
+                RuntimeDescription newRuntimeDescription;
+
+                if (runtimeGraph.Runtimes.TryGetValue(existingRuntimeDescription.RuntimeIdentifier, out newRuntimeDescription))
+                {
+                    // overlapping RID, ensure that the imports match (same ordering and content)
+                    if (!existingRuntimeDescription.InheritedRuntimes.SequenceEqual(newRuntimeDescription.InheritedRuntimes))
+                    {
+                        Log.LogError($"RuntimeGroup {runtimeGroup.BaseRID} defines RID {newRuntimeDescription.RuntimeIdentifier} with imports {String.Join(";", newRuntimeDescription.InheritedRuntimes)} which differ from existing imports {String.Join(";", existingRuntimeDescription.InheritedRuntimes)}.  You may avoid this by specifying OmitRIDs metadata with {newRuntimeDescription.RuntimeIdentifier}.");
+                    }
+                }
+            }
+
+            return RuntimeGraph.Merge(existingGraph, runtimeGraph);
+        }
+
+        private void ValidateImports(RuntimeGraph runtimeGraph)
+        {
+            foreach(var runtimeDescription in runtimeGraph.Runtimes.Values)
+            {
+                foreach(var import in runtimeDescription.InheritedRuntimes)
+                {
+                    if (!runtimeGraph.Runtimes.ContainsKey(import))
+                    {
+                        Log.LogError($"Runtime {runtimeDescription.RuntimeIdentifier} imports {import} which is not defined.");
+                    }
+                }
+            }
+        }
+
+        class QualifierPolicy
+        {
+            public QualifierPolicy(ITaskItem item)
+            {
+                Qualifier = item.ItemSpec;
+                VersionPrecedence = item.GetBoolean(nameof(VersionPrecedence));
+            }
+
+            public string Qualifier { get; }
+            public bool VersionPrecedence { get; }
+        }
+
+        class RuntimeGroup
+        {
+            private const string rootRID = "any";
+            private const char VersionDelimiter = '.';
+            private const char ArchitectureDelimiter = '-';
+            private const char QualifierDelimiter = '-';
+
+            public RuntimeGroup(ITaskItem item)
+            {
+                BaseRID = item.ItemSpec;
+                Parent = item.GetString(nameof(Parent));
+                Versions = item.GetStrings(nameof(Versions));
+                TreatVersionsAsCompatible = item.GetBoolean(nameof(TreatVersionsAsCompatible), true);
+                OmitVersionDelimiter = item.GetBoolean(nameof(OmitVersionDelimiter));
+                ApplyVersionsToParent = item.GetBoolean(nameof(ApplyVersionsToParent));
+                Architectures = item.GetStrings(nameof(Architectures));
+                AdditionalQualifiers = item.GetStrings(nameof(AdditionalQualifiers));
+                OmitRIDs = new HashSet<string>(item.GetStrings(nameof(OmitRIDs)));
+            }
+
+            public string BaseRID { get; }
+            public string Parent { get; }
+            public IEnumerable<string> Versions { get; }
+            public bool TreatVersionsAsCompatible { get; }
+            public bool OmitVersionDelimiter { get; }
+            public bool ApplyVersionsToParent { get; }
+            public IEnumerable<string> Architectures { get; }
+            public IEnumerable<string> AdditionalQualifiers { get; }
+            public ICollection<string> OmitRIDs { get; }
+
+            public IEnumerable<RuntimeDescription> GetRuntimeDescriptions()
+            {
+                // define the base as importing the parent
+                yield return new RuntimeDescription(BaseRID, Parent == null ? Enumerable.Empty<string>() : new[] { Parent });
+
+                // define each arch as importing base and parent-arch
+                foreach(var architecture in Architectures)
+                {
+                    var imports = new List<string>();
+                    imports.Add(BaseRID);
+
+                    if (Parent != null && Parent != rootRID)
+                    {
+                        imports.Add($"{Parent}-{architecture}");
+                    }
+
+                    yield return new RuntimeDescription($"{BaseRID}-{architecture}", imports);
+                }
+
+                var versionDelimiter = OmitVersionDelimiter ? String.Empty : VersionDelimiter.ToString();
+                string lastVersion = null;
+                foreach (var version in Versions)
+                {
+                    var imports = new List<string>();
+
+                    // define each version as importing the version-less base or previous version
+                    if ((lastVersion == null) || TreatVersionsAsCompatible)
+                    {
+                        imports.Add(BaseRID);
+                    }
+                    else
+                    {
+                        imports.Add($"{BaseRID}{versionDelimiter}{lastVersion}");
+                    }
+
+                    if (ApplyVersionsToParent)
+                    {
+                        imports.Add($"{Parent}{versionDelimiter}{version}");
+                    }
+
+                    yield return new RuntimeDescription($"{BaseRID}{versionDelimiter}{version}", imports);
+
+                    foreach (var architecture in Architectures)
+                    {
+                        // define each arch-specific version as importing the versioned base and either a previous version arch-specific RID or the base arch-specific RID
+                        var archImports = new List<string>();
+
+                        archImports.Add($"{BaseRID}{versionDelimiter}{version}");
+
+                        if ((lastVersion == null) || TreatVersionsAsCompatible)
+                        {
+                            archImports.Add($"{BaseRID}{ArchitectureDelimiter}{architecture}");
+                        }
+                        else
+                        {
+                            archImports.Add($"{BaseRID}{versionDelimiter}{lastVersion}{ArchitectureDelimiter}{architecture}");
+                        }
+
+                        if (ApplyVersionsToParent)
+                        {
+                            archImports.Add($"{Parent}{versionDelimiter}{version}{ArchitectureDelimiter}{architecture}");
+                        }
+
+
+                        yield return new RuntimeDescription($"{BaseRID}{versionDelimiter}{version}{ArchitectureDelimiter}{architecture}", archImports);
+                    }
+
+                    lastVersion = version;
+                }
+            }
+
+            private IEnumerable<RuntimeDescription> AddQualifiers(IEnumerable<RuntimeDescription> unQualifiedruntimeDescriptions, Dictionary<string, QualifierPolicy> qualifierPolicies)
+            {
+                foreach(var runtimeDescription in unQualifiedruntimeDescriptions)
+                {
+                    yield return runtimeDescription;
+
+                    foreach(var qualifier in AdditionalQualifiers)
+                    {
+                        var imports = new List<string>(runtimeDescription.InheritedRuntimes
+                                            .NullAsEmpty()
+                                            .Select(rid => rid == null || rid == rootRID ? qualifier : $"{rid}-{qualifier}"));
+
+
+                        QualifierPolicy qualifierPolicy = null;
+
+                        if (qualifierPolicies.TryGetValue(qualifier, out qualifierPolicy) && qualifierPolicy.VersionPrecedence)
+                        {
+                            var versionedRid = runtimeDescription.RuntimeIdentifier;
+
+                            var archIndex = versionedRid.IndexOf('-');
+
+                            if (archIndex != -1)
+                            {
+                                versionedRid = versionedRid.Substring(0, archIndex);
+                            }
+
+                            int insertAt = 0;
+
+
+                            while (insertAt < imports.Count && imports[insertAt].StartsWith(versionedRid))
+                            {
+                                insertAt++;
+                            }
+
+                            imports.Insert(insertAt, runtimeDescription.RuntimeIdentifier);
+                        }
+                        else
+                        {
+                            imports.Add(runtimeDescription.RuntimeIdentifier);
+                        }
+
+
+                        yield return new RuntimeDescription($"{runtimeDescription.RuntimeIdentifier}{QualifierDelimiter}{qualifier}", imports);
+
+                    }
+                }
+            }
+
+            public RuntimeGraph GetRuntimeGraph(Dictionary<string, QualifierPolicy> qualifierPolicies)
+            {
+                var rids = GetRuntimeDescriptions();
+
+                rids = rids.Where(rid => !OmitRIDs.Contains(rid.RuntimeIdentifier));
+
+                rids = AddQualifiers(rids, qualifierPolicies);
+
+                rids = rids.Where(rid => !OmitRIDs.Contains(rid.RuntimeIdentifier));
+
+                return new RuntimeGraph(rids);
+            }
+        }
+    }
+}

src/Microsoft.DotNet.Build.Tasks.Packaging/src/Microsoft.DotNet.Build.Tasks.Packaging.csproj

@@ -21,6 +21,7 @@
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="ApplyMetaPackages.cs" />
+    <Compile Include="GenerateRuntimeGraph.cs" />
     <Compile Include="GetSupportedPackagesFromPackageReports.cs" />
     <Compile Include="GetLayoutFiles.cs" />
     <Compile Include="FilterUnknownPackages.cs" />

src/Microsoft.DotNet.Build.Tasks.Packaging/src/PackageFiles/Packaging.common.targets

@@ -25,6 +25,7 @@
   <UsingTask TaskName="FilterUnknownPackages" AssemblyFile="$(PackagingTaskDir)Microsoft.DotNet.Build.Tasks.Packaging.dll"/>
   <UsingTask TaskName="GenerateNuSpec" AssemblyFile="$(PackagingTaskDir)Microsoft.DotNet.Build.Tasks.Packaging.dll"/>
   <UsingTask TaskName="GeneratePackageReport" AssemblyFile="$(PackagingTaskDir)Microsoft.DotNet.Build.Tasks.Packaging.dll"/>
+  <UsingTask TaskName="GenerateRuntimeGraph" AssemblyFile="$(PackagingTaskDir)Microsoft.DotNet.Build.Tasks.Packaging.dll"/>
   <UsingTask TaskName="GenerateRuntimeDependencies" AssemblyFile="$(PackagingTaskDir)Microsoft.DotNet.Build.Tasks.Packaging.dll"/>
   <UsingTask TaskName="GetApplicableAssetsFromPackages" AssemblyFile="$(PackagingTaskDir)Microsoft.DotNet.Build.Tasks.Packaging.dll"/>
   <UsingTask TaskName="GetAssemblyReferences" AssemblyFile="$(PackagingTaskDir)Microsoft.DotNet.Build.Tasks.Packaging.dll"/>