Get default CorLib reference from DotNetRuntimeInfo

docs/guides/dotnet/basics.md

@@ -24,7 +24,16 @@ references in the `KnownCorLibs` class to target another version of the
 library.
 
 ``` csharp
-var module = new ModuleDefinition("MyModule.exe", KnownCorLibs.SystemRuntime_v4_2_2_0);
+var module = new ModuleDefinition("MyModule.dll", KnownCorLibs.SystemRuntime_v4_2_2_0);
+```
+
+If you have a .NET runtime identifier as specified in the 
+`TargetFrameworkAttribute` of an assembly, you can use the `DotNetRuntimeInfo` 
+structure to get the corresponding default corlib:
+
+``` csharp
+var runtime = DotNetRuntimeInfo.Parse(".NETCoreApp,Version=v3.1");
+var module = new ModuleDefinition("MyModule.dll", runtime.GetDefaultCorLib());
 ```
 
 ## Opening a .NET module

src/AsmResolver.DotNet/DotNetRuntimeInfo.cs

@@ -68,6 +68,16 @@ public Version Version
         /// </summary>
         public bool IsNetStandard => Name == NetStandard;
 
+        /// <summary>
+        /// Parses the framework name as provided in <see cref="TargetFrameworkAttribute"/>.
+        /// </summary>
+        /// <param name="frameworkName">The full runtime name.</param>
+        /// <returns>The parsed version info.</returns>
+        public static DotNetRuntimeInfo Parse(string frameworkName)
+        {
+            return TryParse(frameworkName, out var info) ? info : throw new FormatException();
+        }
+
         /// <summary>
         /// Attempts to parse the framework name as provided in <see cref="TargetFrameworkAttribute"/>.
         /// </summary>
@@ -89,6 +99,13 @@ public static bool TryParse(string frameworkName, out DotNetRuntimeInfo info)
             return true;
         }
 
+        /// <summary>
+        /// Obtains a reference to the default core lib reference of this runtime.
+        /// </summary>
+        /// <returns>The reference to the default core lib.</returns>
+        /// <exception cref="ArgumentException">The runtime information is invalid or unsupported.</exception>
+        public AssemblyReference GetDefaultCorLib() => KnownCorLibs.FromRuntimeInfo(this);
+
         /// <inheritdoc />
         public override string ToString() => $"{Name},Version=v{Version}";
     }

src/AsmResolver.DotNet/KnownCorLibs.cs

@@ -24,7 +24,7 @@ public static class KnownCorLibs
         /// References mscorlib.dll, Version=2.0.0.0, PublicKeyToken=B77A5C561934E089. This is used by .NET assemblies
         /// targeting the .NET Framework 2.0, 3.0 and 3.5.
         /// </summary>
-        public static readonly AssemblyReference MsCorLib_v2_0_0_0 = new AssemblyReference("mscorlib",
+        public static readonly AssemblyReference MsCorLib_v2_0_0_0 = new("mscorlib",
             new Version(2, 0, 0, 0), false, new byte[]
             {
                 0xB7, 0x7A, 0x5C, 0x56, 0x19, 0x34, 0xE0, 0x89
@@ -34,7 +34,7 @@ public static class KnownCorLibs
         /// References mscorlib.dll, Version=4.0.0.0, PublicKeyToken=B77A5C561934E089. This is used by .NET assemblies
         /// targeting the .NET Framework 4.0 and later.
         /// </summary>
-        public static readonly AssemblyReference MsCorLib_v4_0_0_0 = new AssemblyReference("mscorlib",
+        public static readonly AssemblyReference MsCorLib_v4_0_0_0 = new("mscorlib",
             new Version(4, 0, 0, 0), false, new byte[]
             {
                 0xB7, 0x7A, 0x5C, 0x56, 0x19, 0x34, 0xE0, 0x89
@@ -44,7 +44,7 @@ public static class KnownCorLibs
         /// References System.Private.CoreLib.dll, Version=4.0.0.0, PublicKeyToken=7CEC85D7BEA7798E. This is used by .NET
         /// assemblies targeting .NET Core 1.0 and later.
         /// </summary>
-        public static readonly AssemblyReference SystemPrivateCoreLib_v4_0_0_0 = new AssemblyReference("System.Private.CoreLib",
+        public static readonly AssemblyReference SystemPrivateCoreLib_v4_0_0_0 = new("System.Private.CoreLib",
             new Version(4, 0, 0, 0), false, new byte[]
             {
                 0x7C, 0xEC, 0x85, 0xD7, 0xBE, 0xA7, 0x79, 0x8E
@@ -54,7 +54,7 @@ public static class KnownCorLibs
         /// References System.Private.CoreLib.dll, Version=5.0.0.0, PublicKeyToken=7CEC85D7BEA7798E. This is used by .NET
         /// assemblies targeting .NET 5.0.
         /// </summary>
-        public static readonly AssemblyReference SystemPrivateCoreLib_v5_0_0_0 = new AssemblyReference("System.Private.CoreLib",
+        public static readonly AssemblyReference SystemPrivateCoreLib_v5_0_0_0 = new("System.Private.CoreLib",
             new Version(5, 0, 0, 0), false, new byte[]
             {
                 0x7C, 0xEC, 0x85, 0xD7, 0xBE, 0xA7, 0x79, 0x8E
@@ -64,7 +64,7 @@ public static class KnownCorLibs
         /// References System.Private.CoreLib.dll, Version=6.0.0.0, PublicKeyToken=7CEC85D7BEA7798E. This is used by .NET
         /// assemblies targeting .NET 6.0.
         /// </summary>
-        public static readonly AssemblyReference SystemPrivateCoreLib_v6_0_0_0 = new AssemblyReference("System.Private.CoreLib",
+        public static readonly AssemblyReference SystemPrivateCoreLib_v6_0_0_0 = new("System.Private.CoreLib",
             new Version(6, 0, 0, 0), false, new byte[]
             {
                 0x7C, 0xEC, 0x85, 0xD7, 0xBE, 0xA7, 0x79, 0x8E
@@ -74,37 +74,77 @@ public static class KnownCorLibs
         /// References System.Private.CoreLib.dll, Version=7.0.0.0, PublicKeyToken=7CEC85D7BEA7798E. This is used by .NET
         /// assemblies targeting .NET 7.0.
         /// </summary>
-        public static readonly AssemblyReference SystemPrivateCoreLib_v7_0_0_0 = new AssemblyReference("System.Private.CoreLib",
+        public static readonly AssemblyReference SystemPrivateCoreLib_v7_0_0_0 = new("System.Private.CoreLib",
             new Version(7, 0, 0, 0), false, new byte[]
             {
                 0x7C, 0xEC, 0x85, 0xD7, 0xBE, 0xA7, 0x79, 0x8E
             });
 
+        /// <summary>
+        /// References System.Private.CoreLib.dll, Version=8.0.0.0, PublicKeyToken=7CEC85D7BEA7798E. This is used by .NET
+        /// assemblies targeting .NET 8.0.
+        /// </summary>
+        public static readonly AssemblyReference SystemPrivateCoreLib_v8_0_0_0 = new("System.Private.CoreLib",
+            new Version(8, 0, 0, 0), false, new byte[]
+            {
+                0x7C, 0xEC, 0x85, 0xD7, 0xBE, 0xA7, 0x79, 0x8E
+            });
+
+        /// <summary>
+        /// References System.Runtime.dll, Version=4.0.0.0, PublicKeyToken=B03F5F7F11D50A3A. This is used by .NET
+        /// assemblies targeting .NET standard 1.0 and 1.1.
+        /// </summary>
+        public static readonly AssemblyReference SystemRuntime_v4_0_0_0 = new("System.Runtime",
+            new Version(4, 0, 0, 0), false, new byte[]
+            {
+                0xB0, 0x3F, 0x5F, 0x7F, 0x11, 0xD5, 0x0A, 0x3A
+            });
+
+        /// <summary>
+        /// References System.Runtime.dll, Version=4.0.0.0, PublicKeyToken=B03F5F7F11D50A3A. This is used by .NET
+        /// assemblies targeting .NET standard 1.2.
+        /// </summary>
+        public static readonly AssemblyReference SystemRuntime_v4_0_10_0 = new("System.Runtime",
+            new Version(4, 0, 0, 0), false, new byte[]
+            {
+                0xB0, 0x3F, 0x5F, 0x7F, 0x11, 0xD5, 0x0A, 0x3A
+            });
+
         /// <summary>
         /// References System.Runtime.dll, Version=4.0.20.0, PublicKeyToken=B03F5F7F11D50A3A. This is used by .NET
         /// assemblies targeting .NET standard 1.3 and 1.4.
         /// </summary>
-        public static readonly AssemblyReference SystemRuntime_v4_0_20_0 = new AssemblyReference("System.Runtime",
+        public static readonly AssemblyReference SystemRuntime_v4_0_20_0 = new("System.Runtime",
             new Version(4, 0, 20, 0), false, new byte[]
             {
                 0xB0, 0x3F, 0x5F, 0x7F, 0x11, 0xD5, 0x0A, 0x3A
             });
 
         /// <summary>
         /// References System.Runtime.dll, Version=4.0.0.0, PublicKeyToken=B03F5F7F11D50A3A. This is used by .NET
-        /// assemblies targeting .NET standard 1.5, 1.6 and 1.7.
+        /// assemblies targeting .NET standard 1.5, 1.6 and 1.7, and .NET Core 1.0 and 1.1.
         /// </summary>
-        public static readonly AssemblyReference SystemRuntime_v4_1_0_0 = new AssemblyReference("System.Runtime",
+        public static readonly AssemblyReference SystemRuntime_v4_1_0_0 = new("System.Runtime",
             new Version(4, 1, 0, 0), false, new byte[]
             {
                 0xB0, 0x3F, 0x5F, 0x7F, 0x11, 0xD5, 0x0A, 0x3A
             });
 
+        /// <summary>
+        /// References System.Runtime.dll, Version=4.2.0.0, PublicKeyToken=B03F5F7F11D50A3A. This is used by .NET
+        /// assemblies targeting .NET Core 2.0.
+        /// </summary>
+        public static readonly AssemblyReference SystemRuntime_v4_2_0_0 = new("System.Runtime",
+            new Version(4, 2, 0, 0), false, new byte[]
+            {
+                0xB0, 0x3F, 0x5F, 0x7F, 0x11, 0xD5, 0x0A, 0x3A
+            });
+
         /// <summary>
         /// References System.Runtime.dll, Version=4.2.1.0, PublicKeyToken=B03F5F7F11D50A3A. This is used by .NET
-        /// assemblies targeting .NET Core 2.1.
+        /// assemblies targeting .NET Core 2.1 and 3.0.
         /// </summary>
-        public static readonly AssemblyReference SystemRuntime_v4_2_1_0 = new AssemblyReference("System.Runtime",
+        public static readonly AssemblyReference SystemRuntime_v4_2_1_0 = new("System.Runtime",
             new Version(4, 2, 1, 0), false, new byte[]
             {
                 0xB0, 0x3F, 0x5F, 0x7F, 0x11, 0xD5, 0x0A, 0x3A
@@ -114,7 +154,7 @@ public static class KnownCorLibs
         /// References System.Runtime.dll, Version=4.2.2.0, PublicKeyToken=B03F5F7F11D50A3A. This is used by .NET
         /// assemblies targeting .NET Core 3.1.
         /// </summary>
-        public static readonly AssemblyReference SystemRuntime_v4_2_2_0 = new AssemblyReference("System.Runtime",
+        public static readonly AssemblyReference SystemRuntime_v4_2_2_0 = new("System.Runtime",
             new Version(4, 2, 2, 0), false, new byte[]
             {
                 0xB0, 0x3F, 0x5F, 0x7F, 0x11, 0xD5, 0x0A, 0x3A
@@ -124,7 +164,7 @@ public static class KnownCorLibs
         /// References System.Runtime.dll, Version=5.0.0.0, PublicKeyToken=B03F5F7F11D50A3A. This is used by .NET
         /// assemblies targeting .NET 5.0.
         /// </summary>
-        public static readonly AssemblyReference SystemRuntime_v5_0_0_0 = new AssemblyReference("System.Runtime",
+        public static readonly AssemblyReference SystemRuntime_v5_0_0_0 = new("System.Runtime",
             new Version(5, 0, 0, 0), false, new byte[]
             {
                 0xB0, 0x3F, 0x5F, 0x7F, 0x11, 0xD5, 0x0A, 0x3A
@@ -134,7 +174,7 @@ public static class KnownCorLibs
         /// References System.Runtime.dll, Version=6.0.0.0, PublicKeyToken=B03F5F7F11D50A3A. This is used by .NET
         /// assemblies targeting .NET 6.0.
         /// </summary>
-        public static readonly AssemblyReference SystemRuntime_v6_0_0_0 = new AssemblyReference("System.Runtime",
+        public static readonly AssemblyReference SystemRuntime_v6_0_0_0 = new("System.Runtime",
             new Version(6, 0, 0, 0), false, new byte[]
             {
                 0xB0, 0x3F, 0x5F, 0x7F, 0x11, 0xD5, 0x0A, 0x3A
@@ -144,17 +184,27 @@ public static class KnownCorLibs
         /// References System.Runtime.dll, Version=7.0.0.0, PublicKeyToken=B03F5F7F11D50A3A. This is used by .NET
         /// assemblies targeting .NET 7.0.
         /// </summary>
-        public static readonly AssemblyReference SystemRuntime_v7_0_0_0 = new AssemblyReference("System.Runtime",
+        public static readonly AssemblyReference SystemRuntime_v7_0_0_0 = new("System.Runtime",
             new Version(7, 0, 0, 0), false, new byte[]
             {
                 0xB0, 0x3F, 0x5F, 0x7F, 0x11, 0xD5, 0x0A, 0x3A
             });
 
+        /// <summary>
+        /// References System.Runtime.dll, Version=8.0.0.0, PublicKeyToken=B03F5F7F11D50A3A. This is used by .NET
+        /// assemblies targeting .NET 8.0.
+        /// </summary>
+        public static readonly AssemblyReference SystemRuntime_v8_0_0_0 = new("System.Runtime",
+            new Version(8, 0, 0, 0), false, new byte[]
+            {
+                0xB0, 0x3F, 0x5F, 0x7F, 0x11, 0xD5, 0x0A, 0x3A
+            });
+
         /// <summary>
         /// References netstandard.dll, Version=2.0.0.0, PublicKeyToken=CC7B13FFCD2DDD51. This is used by .NET
         /// assemblies targeting .NET standard 2.0.
         /// </summary>
-        public static readonly AssemblyReference NetStandard_v2_0_0_0 = new AssemblyReference("netstandard",
+        public static readonly AssemblyReference NetStandard_v2_0_0_0 = new("netstandard",
             new Version(2, 0, 0, 0), false, new byte[]
             {
                 0xCC, 0x7B, 0x13, 0xFF, 0xCD, 0x2D, 0xDD, 0x51
@@ -164,7 +214,7 @@ public static class KnownCorLibs
         /// References netstandard.dll, Version=2.1.0.0, PublicKeyToken=CC7B13FFCD2DDD51. This is used by .NET
         /// assemblies targeting .NET standard 2.1.
         /// </summary>
-        public static readonly AssemblyReference NetStandard_v2_1_0_0 = new AssemblyReference("netstandard",
+        public static readonly AssemblyReference NetStandard_v2_1_0_0 = new("netstandard",
             new Version(2, 1, 0, 0), false, new byte[]
             {
                 0xCC, 0x7B, 0x13, 0xFF, 0xCD, 0x2D, 0xDD, 0x51
@@ -178,20 +228,80 @@ static KnownCorLibs()
                 NetStandard_v2_1_0_0,
                 MsCorLib_v2_0_0_0,
                 MsCorLib_v4_0_0_0,
+                SystemRuntime_v4_0_0_0,
+                SystemRuntime_v4_0_10_0,
                 SystemRuntime_v4_0_20_0,
                 SystemRuntime_v4_1_0_0,
+                SystemRuntime_v4_2_0_0,
                 SystemRuntime_v4_2_1_0,
                 SystemRuntime_v4_2_2_0,
                 SystemRuntime_v5_0_0_0,
                 SystemRuntime_v6_0_0_0,
                 SystemRuntime_v7_0_0_0,
+                SystemRuntime_v8_0_0_0,
                 SystemPrivateCoreLib_v4_0_0_0,
                 SystemPrivateCoreLib_v5_0_0_0,
                 SystemPrivateCoreLib_v6_0_0_0,
-                SystemPrivateCoreLib_v7_0_0_0
+                SystemPrivateCoreLib_v7_0_0_0,
+                SystemPrivateCoreLib_v8_0_0_0,
             };
 
             KnownCorLibNames = new HashSet<string>(KnownCorLibReferences.Select(r => r.Name!.Value));
         }
+
+        /// <summary>
+        /// Obtains a reference to the default core lib reference for the provided .NET target runtime.
+        /// </summary>
+        /// <param name="runtimeInfo">The runtime to target.</param>
+        /// <returns>The reference to the default core lib.</returns>
+        /// <exception cref="ArgumentException">The runtime information is invalid or unsupported.</exception>
+        public static AssemblyReference FromRuntimeInfo(DotNetRuntimeInfo runtimeInfo)
+        {
+            if (runtimeInfo.IsNetFramework)
+                return SelectFrameworkCorLib(runtimeInfo.Version);
+
+            if (runtimeInfo.IsNetStandard)
+                return SelectNetStandardCorLib(runtimeInfo.Version);
+
+            if (runtimeInfo.IsNetCoreApp)
+                return SelectNetCoreCorLib(runtimeInfo.Version);
+
+            throw new ArgumentException($"Invalid or unsupported runtime version {runtimeInfo}.");
+        }
+
+        private static AssemblyReference SelectFrameworkCorLib(Version version) => version.Major < 4
+            ? MsCorLib_v2_0_0_0
+            : MsCorLib_v4_0_0_0;
+
+        private static AssemblyReference SelectNetStandardCorLib(Version version)
+        {
+            return (version.Major, version.Minor) switch
+            {
+                (1, 0 or 1) => SystemRuntime_v4_0_0_0,
+                (1, 2) => SystemRuntime_v4_0_10_0,
+                (1, 3 or 4) => SystemRuntime_v4_0_20_0,
+                (1, 5 or 6 or 7) => SystemRuntime_v4_1_0_0,
+                (2, 0) => NetStandard_v2_0_0_0,
+                (2, 1) => NetStandard_v2_1_0_0,
+                _ => throw new ArgumentException($"Invalid or unsupported .NET standard version {version}.")
+            };
+        }
+
+        private static AssemblyReference SelectNetCoreCorLib(Version version)
+        {
+            return (version.Major, version.Minor) switch
+            {
+                (1, 0 or 1) => SystemRuntime_v4_1_0_0,
+                (2, 0) => SystemRuntime_v4_2_0_0,
+                (2, 1) or (3, 0) => SystemRuntime_v4_2_1_0,
+                (3, 1) => SystemRuntime_v4_2_2_0,
+                (5, 0) => SystemRuntime_v5_0_0_0,
+                (6, 0) => SystemRuntime_v6_0_0_0,
+                (7, 0) => SystemRuntime_v7_0_0_0,
+                (8, 0) => SystemRuntime_v8_0_0_0,
+                _ => throw new ArgumentException($"Invalid or unsupported .NET or .NET Core version {version}.")
+            };
+        }
+
     }
 }

src/AsmResolver.DotNet/ReflectionAssemblyDescriptor.cs

@@ -10,9 +10,21 @@ namespace AsmResolver.DotNet
     /// </summary>
     public class ReflectionAssemblyDescriptor : AssemblyDescriptor
     {
-        private readonly ModuleDefinition _parentModule;
+        private readonly ModuleDefinition? _parentModule;
         private readonly AssemblyName _assemblyName;
 
+        /// <summary>
+        /// Creates a new instance of the <see cref="ReflectionAssemblyDescriptor"/> class.
+        /// </summary>
+        /// <param name="assemblyName">The assembly name to import.</param>
+        public ReflectionAssemblyDescriptor(AssemblyName assemblyName)
+            : base(new MetadataToken(TableIndex.AssemblyRef, 0))
+        {
+            _parentModule = null;
+            _assemblyName = assemblyName;
+            Version = assemblyName.Version ?? new Version();
+        }
+
         /// <summary>
         /// Creates a new instance of the <see cref="ReflectionAssemblyDescriptor"/> class.
         /// </summary>
@@ -46,6 +58,6 @@ public override AssemblyReference ImportWith(ReferenceImporter importer) =>
         public override byte[]? GetPublicKeyToken() => _assemblyName.GetPublicKeyToken();
 
         /// <inheritdoc />
-        public override AssemblyDefinition? Resolve() => _parentModule.MetadataResolver.AssemblyResolver.Resolve(this);
+        public override AssemblyDefinition? Resolve() => _parentModule?.MetadataResolver.AssemblyResolver.Resolve(this);
     }
 }

test/AsmResolver.DotNet.Tests/DotNetRuntimeInfoTest.cs

@@ -0,0 +1,25 @@
+using System.Reflection;
+using AsmResolver.DotNet.Signatures;
+using Xunit;
+
+namespace AsmResolver.DotNet.Tests
+{
+    public class DotNetRuntimeInfoTest
+    {
+        [Theory]
+        [InlineData(".NETFramework,Version=v2.0", "mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
+        [InlineData(".NETFramework,Version=v3.5", "mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
+        [InlineData(".NETFramework,Version=v4.0", "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
+        [InlineData(".NETStandard,Version=v1.0", "System.Runtime, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")]
+        [InlineData(".NETStandard,Version=v2.0", "netstandard, Version=2.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51")]
+        [InlineData(".NETCoreApp,Version=v2.0", "System.Runtime, Version=4.2.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")]
+        [InlineData(".NETCoreApp,Version=v5.0", "System.Runtime, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")]
+        public void DefaultCorLib(string name, string expectedCorLib)
+        {
+            Assert.Equal(
+                new ReflectionAssemblyDescriptor(new AssemblyName(expectedCorLib)),
+                (AssemblyDescriptor) DotNetRuntimeInfo.Parse(name).GetDefaultCorLib(),
+                SignatureComparer.Default);
+        }
+    }
+}