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Merge pull request #1714 from tmds/lib_resolve_linux
Linux: support broader range of distros/architectures by trying to load packed native libraries.
2 parents 8950f49 + cdab62d commit 6740402

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‎LibGit2Sharp/Core/NativeMethods.cs

+126-11
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,6 @@
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using System;
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using System.IO;
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using System.Reflection;
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using System.Runtime.CompilerServices;
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using System.Runtime.ConstrainedExecution;
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using System.Runtime.InteropServices;
@@ -29,32 +30,146 @@ static NativeMethods()
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{
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if (Platform.IsRunningOnNetFramework() || Platform.IsRunningOnNetCore())
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{
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string nativeLibraryDir = GlobalSettings.GetAndLockNativeLibraryPath();
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if (nativeLibraryDir != null)
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// Use .NET Core 3.0+ NativeLibrary when available.
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if (!TryUseNativeLibrary())
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{
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string nativeLibraryPath = Path.Combine(nativeLibraryDir, libgit2 + Platform.GetNativeLibraryExtension());
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// NativeLibrary is not available, fall back.
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// Use GlobalSettings.NativeLibraryPath when set.
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// Try to load the .dll from the path explicitly.
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// If this call succeeds further DllImports will find the library loaded and not attempt to load it again.
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// If it fails the next DllImport will load the library from safe directories.
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string nativeLibraryPath = GetGlobalSettingsNativeLibraryPath();
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if (nativeLibraryPath != null)
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{
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#if NETFRAMEWORK
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if (Platform.OperatingSystem == OperatingSystemType.Windows)
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if (Platform.OperatingSystem == OperatingSystemType.Windows)
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#else
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if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
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if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
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#endif
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{
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LoadWindowsLibrary(nativeLibraryPath);
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}
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else
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{
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LoadUnixLibrary(nativeLibraryPath, RTLD_NOW);
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{
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LoadWindowsLibrary(nativeLibraryPath);
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}
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else
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{
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LoadUnixLibrary(nativeLibraryPath, RTLD_NOW);
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}
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}
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}
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}
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InitializeNativeLibrary();
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}
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private static string GetGlobalSettingsNativeLibraryPath()
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{
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string nativeLibraryDir = GlobalSettings.GetAndLockNativeLibraryPath();
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if (nativeLibraryDir == null)
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{
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return null;
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}
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return Path.Combine(nativeLibraryDir, libgit2 + Platform.GetNativeLibraryExtension());
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}
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private delegate bool TryLoadLibraryByNameDelegate(string libraryName, Assembly assembly, DllImportSearchPath? searchPath, out IntPtr handle);
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private delegate bool TryLoadLibraryByPathDelegate(string libraryPath, out IntPtr handle);
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static TryLoadLibraryByNameDelegate _tryLoadLibraryByName;
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static TryLoadLibraryByPathDelegate _tryLoadLibraryByPath;
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static bool TryLoadLibrary(string libraryName, Assembly assembly, DllImportSearchPath? searchPath, out IntPtr handle)
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{
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if (_tryLoadLibraryByName == null)
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{
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throw new NotSupportedException();
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}
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return _tryLoadLibraryByName(libraryName, assembly, searchPath, out handle);
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}
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static bool TryLoadLibrary(string libraryPath, out IntPtr handle)
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{
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if (_tryLoadLibraryByPath == null)
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{
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throw new NotSupportedException();
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}
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return _tryLoadLibraryByPath(libraryPath, out handle);
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}
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private static bool TryUseNativeLibrary()
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{
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// NativeLibrary is available in .NET Core 3.0+.
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// We use reflection to use NativeLibrary so this library can target 'netstandard2.0'.
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Type dllImportResolverType = Type.GetType("System.Runtime.InteropServices.DllImportResolver, System.Runtime.InteropServices", throwOnError: false);
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Type nativeLibraryType = Type.GetType("System.Runtime.InteropServices.NativeLibrary, System.Runtime.InteropServices", throwOnError: false);
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var tryLoadLibraryByName = (TryLoadLibraryByNameDelegate)nativeLibraryType?.GetMethod("TryLoad",
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new Type[] { typeof(string), typeof(Assembly), typeof(DllImportSearchPath?), typeof(IntPtr).MakeByRefType() })?.CreateDelegate(typeof(TryLoadLibraryByNameDelegate));
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var tryLoadLibraryByPath = (TryLoadLibraryByPathDelegate)nativeLibraryType?.GetMethod("TryLoad",
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new Type[] { typeof(string), typeof(IntPtr).MakeByRefType() })?.CreateDelegate(typeof(TryLoadLibraryByPathDelegate));
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MethodInfo setDllImportResolver = nativeLibraryType?.GetMethod("SetDllImportResolver", new Type[] { typeof(Assembly), dllImportResolverType});
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if (dllImportResolverType == null ||
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nativeLibraryType == null ||
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tryLoadLibraryByName == null ||
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tryLoadLibraryByPath == null ||
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setDllImportResolver == null)
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{
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return false;
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}
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_tryLoadLibraryByPath = tryLoadLibraryByPath;
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_tryLoadLibraryByName = tryLoadLibraryByName;
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// NativeMethods.SetDllImportResolver(typeof(NativeMethods).Assembly, ResolveDll);
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object resolveDelegate = typeof(NativeMethods).GetMethod(nameof(ResolveDll), BindingFlags.NonPublic | BindingFlags.Static).CreateDelegate(dllImportResolverType);
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setDllImportResolver.Invoke(null, new object[] { typeof(NativeMethods).Assembly, resolveDelegate });
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return true;
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}
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private static IntPtr ResolveDll(string libraryName, Assembly assembly, DllImportSearchPath? searchPath)
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{
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IntPtr handle = IntPtr.Zero;
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if (libraryName == libgit2)
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{
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// Use GlobalSettings.NativeLibraryPath when set.
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string nativeLibraryPath = GetGlobalSettingsNativeLibraryPath();
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if (nativeLibraryPath != null &&
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TryLoadLibrary(nativeLibraryPath, out handle))
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{
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return handle;
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}
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// Use Default DllImport resolution.
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if (TryLoadLibrary(libraryName, assembly, searchPath, out handle))
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{
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return handle;
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}
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#if NETFRAMEWORK
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#else
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// We cary a number of .so files for Linux which are linked against various
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// libc/OpenSSL libraries. Try them out.
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if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
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{
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// The libraries are located at 'runtimes/<rid>/native/lib{libraryName}.so'
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// The <rid> ends with the processor architecture. e.g. fedora-x64.
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string assemblyDirectory = Path.GetDirectoryName(typeof(NativeMethods).Assembly.Location);
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string processorArchitecture = RuntimeInformation.ProcessArchitecture.ToString().ToLowerInvariant();
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foreach (var runtimeFolder in Directory.GetDirectories(Path.Combine(assemblyDirectory, "runtimes"), $"*-{processorArchitecture}"))
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{
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string libPath = Path.Combine(runtimeFolder, "native", $"lib{libraryName}.so");
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if (TryLoadLibrary(libPath, out handle))
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{
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return handle;
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}
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}
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}
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#endif
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}
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return handle;
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}
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public const int RTLD_NOW = 0x002;
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[DllImport("libdl", EntryPoint = "dlopen")]

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