Implement NativeLibrary.GetEntryPointModuleHandle

src/coreclr/hosts/corerun/CMakeLists.txt

@@ -8,6 +8,9 @@ else(CLR_CMAKE_HOST_WIN32)
     include(configure.cmake)
 endif(CLR_CMAKE_HOST_WIN32)
 
+#Required to expose symbols for global symbol discovery.
+set(CLR_CMAKE_KEEP_NATIVE_SYMBOLS TRUE)
+
 add_executable_clr(corerun
   corerun.cpp
   dotenv.cpp
@@ -25,6 +28,8 @@ if(CLR_CMAKE_HOST_WIN32)
     )
 else(CLR_CMAKE_HOST_WIN32)
     target_link_libraries(corerun ${CMAKE_DL_LIBS})
+    # Required to expose symbols for global symbol discovery
+    target_link_libraries(corerun -rdynamic)
 
     # Android implements pthread natively
     if(NOT CLR_CMAKE_TARGET_ANDROID)

src/coreclr/hosts/corerun/corerun.cpp

@@ -564,16 +564,13 @@ int MAIN(const int argc, const char_t* argv[])
     return exit_code;
 }
 
-#ifdef TARGET_WINDOWS
-// Used by CoreShim to determine running CoreCLR details.
-extern "C" __declspec(dllexport) HRESULT __cdecl GetCurrentClrDetails(void** clrInstance, unsigned int* appDomainId)
+extern "C" DLL_EXPORT HRESULT CDECL GetCurrentClrDetails(void** clrInstance, unsigned int* appDomainId)
 {
     assert(clrInstance != nullptr && appDomainId != nullptr);
     *clrInstance = CurrentClrInstance;
     *appDomainId = CurrentAppDomainId;
     return S_OK;
 }
-#endif // TARGET_WINDOWS
 
 //
 // Self testing for corerun.

src/coreclr/hosts/corerun/corerun.hpp

@@ -47,8 +47,10 @@ namespace pal
 }
 
 #ifdef TARGET_WINDOWS
+#define CDECL __cdecl
 #include <Windows.h>
 
+#define DLL_EXPORT __declspec(dllexport)
 #define MAIN __cdecl wmain
 #define W(str) L ## str
 
@@ -316,17 +318,25 @@ class platform_specific_actions final
 #include <config.h>
 #include <minipal/getexepath.h>
 
+#if __GNUC__ >= 4
+#define DLL_EXPORT __attribute__ ((visibility ("default")))
+#else
+#define DLL_EXPORT
+#endif
+#define CDECL
 #define MAIN main
 #define W(str) str
-#define FAILED(result) (result < 0)
-
+#define S_OK 0
+#define FAILED(result) (result < S_OK)
 #if !HAVE_DIRENT_D_TYPE
 #define DT_UNKNOWN 0
 #define DT_DIR 4
 #define DT_REG 8
 #define DT_LNK 10
 #endif
 
+typedef int HRESULT;
+
 namespace pal
 {
     using char_t = char;

src/coreclr/nativeaot/System.Private.CoreLib/src/System.Private.CoreLib.csproj

@@ -327,9 +327,6 @@
     <Compile Include="$(CommonPath)\Interop\Unix\System.Native\Interop.SchedGetCpu.cs">
       <Link>Interop\Unix\System.Native\Interop.SchedGetCpu.cs</Link>
     </Compile>
-    <Compile Include="$(CommonPath)\Interop\Unix\System.Native\Interop.DynamicLoad.cs">
-      <Link>Interop\Unix\System.Native\Interop.DynamicLoad.cs</Link>
-    </Compile>
     <Compile Include="$(CommonPath)\Interop\Unix\System.Native\Interop.Threading.cs">
       <Link>Interop\Unix\System.Native\Interop.Threading.cs</Link>
     </Compile>

src/coreclr/vm/nativelibrarynative.cpp

@@ -70,4 +70,3 @@ extern "C" INT_PTR QCALLTYPE NativeLibrary_GetSymbol(INT_PTR handle, LPCWSTR sym
 
     return address;
 }
-

src/libraries/Common/src/Interop/Unix/System.Native/Interop.DynamicLoad.cs

@@ -19,5 +19,8 @@ internal unsafe partial class Sys
 
         [LibraryImport(Interop.Libraries.SystemNative, EntryPoint = "SystemNative_FreeLibrary")]
         internal static partial void FreeLibrary(IntPtr handle);
+
+        [LibraryImport(Libraries.SystemNative, EntryPoint = "SystemNative_GetDefaultSearchOrderPseudoHandle", SetLastError = true)]
+        internal static partial IntPtr GetDefaultSearchOrderPseudoHandle();
     }
 }

src/libraries/System.Private.CoreLib/src/System.Private.CoreLib.Shared.projitems

@@ -1831,6 +1831,9 @@
     <Compile Include="$(CommonPath)Interop\Windows\User32\Interop.USEROBJECTFLAGS.cs">
       <Link>Common\Interop\Windows\User32\Interop.USEROBJECTFLAGS.cs</Link>
     </Compile>
+    <Compile Include="$(CommonPath)Interop\Windows\Kernel32\Interop.GetModuleHandle.cs">
+      <Link>Common\Interop\Windows\Kernel32\Interop.GetModuleHandle.cs</Link>
+    </Compile>
     <Compile Include="$(CommonPath)System\IO\FileSystem.Attributes.Windows.cs">
       <Link>Common\System\IO\FileSystem.Attributes.Windows.cs</Link>
     </Compile>
@@ -1973,6 +1976,9 @@
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.CopyFile.cs">
       <Link>Common\Interop\Unix\System.Native\Interop.CopyFile.cs</Link>
     </Compile>
+    <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.DynamicLoad.cs">
+      <Link>Common\Interop\Unix\System.Native\Interop.DynamicLoad.cs</Link>
+    </Compile>
     <Compile Include="$(CommonPath)Interop\Unix\System.Native\Interop.ErrNo.cs">
       <Link>Common\Interop\Unix\System.Native\Interop.ErrNo.cs</Link>
     </Compile>

src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/NativeLibrary.cs

@@ -1,6 +1,7 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.ComponentModel;
 using System.Reflection;
 using System.Runtime.CompilerServices;
 using System.Threading;
@@ -231,5 +232,26 @@ internal static IntPtr LoadLibraryCallbackStub(string libraryName, Assembly asse
 
             return resolver(libraryName, assembly, hasDllImportSearchPathFlags ? (DllImportSearchPath?)dllImportSearchPathFlags : null);
         }
+
+        /// <summary>
+        /// Get a handle that can be used with <see cref="GetExport" /> or <see cref="TryGetExport" /> to resolve exports from the entry point module.
+        /// </summary>
+        /// <returns> The handle that can be used to resolve exports from the entry point module.</returns>
+        public static IntPtr GetMainProgramHandle()
+        {
+            IntPtr result = IntPtr.Zero;
+#if TARGET_WINDOWS
+            result = Interop.Kernel32.GetModuleHandle(null);
+#else
+            result = Interop.Sys.GetDefaultSearchOrderPseudoHandle();
+#endif
+            // I don't know when a failure case can occur here, but checking for it and throwing an exception
+            // if we encounter it.
+            if (result == IntPtr.Zero)
+            {
+                throw new Win32Exception(Marshal.GetLastPInvokeError());
+            }
+            return result;
+        }
     }
 }

src/libraries/System.Runtime.InteropServices/ref/System.Runtime.InteropServices.cs

@@ -774,6 +774,7 @@ public MarshalDirectiveException(string? message, System.Exception? inner) { }
     public static partial class NativeLibrary
     {
         public static void Free(System.IntPtr handle) { }
+        public static System.IntPtr GetMainProgramHandle() { throw null; }
         public static System.IntPtr GetExport(System.IntPtr handle, string name) { throw null; }
         public static System.IntPtr Load(string libraryPath) { throw null; }
         public static System.IntPtr Load(string libraryName, System.Reflection.Assembly assembly, System.Runtime.InteropServices.DllImportSearchPath? searchPath) { throw null; }

src/mono/mono/metadata/native-library.c

@@ -757,32 +757,35 @@ netcore_check_alc_cache (MonoAssemblyLoadContext *alc, const char *scope)
 	return result;
 }
 
+static MonoDl*
+netcore_lookup_self_native_handle()
+{
+	char *error_msg = NULL;
+	if (!internal_module)
+		internal_module = mono_dl_open_self (&error_msg);
+
+	if (!internal_module) {
+		mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_DLLIMPORT, "DllImport error loading library '__Internal': '%s'.", error_msg);
+		g_free (error_msg);
+	}
+	mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_DLLIMPORT, "Native library found via __Internal.");
+	return internal_module;
+}
+
 static MonoDl *
 netcore_lookup_native_library (MonoAssemblyLoadContext *alc, MonoImage *image, const char *scope, guint32 flags)
 {
 	MonoDl *module = NULL;
 	MonoDl *cached;
 	MonoAssembly *assembly = mono_image_get_assembly (image);
-	char *error_msg = NULL;
 
 	MONO_REQ_GC_UNSAFE_MODE;
 
 	mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_DLLIMPORT, "DllImport attempting to load: '%s'.", scope);
 
 	// We allow a special name to dlopen from the running process namespace, which is not present in CoreCLR
 	if (strcmp (scope, "__Internal") == 0) {
-		if (!internal_module)
-			internal_module = mono_dl_open_self (&error_msg);
-		module = internal_module;
-
-		if (!module) {
-			mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_DLLIMPORT, "DllImport error loading library '__Internal': '%s'.", error_msg);
-			g_free (error_msg);
-		}
-
-		mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_DLLIMPORT, "Native library found via __Internal: '%s'.", scope);
-
-		return module;
+		return netcore_lookup_self_native_handle();
 	}
 
 	/*
@@ -1219,9 +1222,9 @@ ves_icall_System_Runtime_InteropServices_NativeLibrary_FreeLib (gpointer lib, Mo
 		g_hash_table_add (native_library_module_blocklist, module);
 		mono_dl_close (module);
 	} else {
-		MonoDl raw_module = { { 0 } };
-		raw_module.handle = lib;
-		mono_dl_close (&raw_module);
+		MonoDl* raw_module = g_new0(MonoDl, 1);
+		raw_module->handle = lib;
+		mono_dl_close (raw_module);
 	}
 
 leave:

src/native/libs/System.Native/entrypoints.c

@@ -234,6 +234,7 @@ static const Entry s_sysNative[] =
     DllImportEntry(SystemNative_LoadLibrary)
     DllImportEntry(SystemNative_GetProcAddress)
     DllImportEntry(SystemNative_FreeLibrary)
+    DllImportEntry(SystemNative_GetDefaultSearchOrderPseudoHandle)
     DllImportEntry(SystemNative_SchedGetCpu)
     DllImportEntry(SystemNative_Exit)
     DllImportEntry(SystemNative_Abort)

src/native/libs/System.Native/pal_dynamicload.c

@@ -50,3 +50,20 @@ void SystemNative_FreeLibrary(void* handle)
 {
     dlclose(handle);
 }
+
+#ifdef TARGET_ANDROID
+void* SystemNative_GetDefaultSearchOrderPseudoHandle(void)
+{
+    return (void*)RTLD_DEFAULT;
+}
+#else
+static void* g_defaultSearchOrderPseudoHandle = NULL;
+void* SystemNative_GetDefaultSearchOrderPseudoHandle(void)
+{
+    if (g_defaultSearchOrderPseudoHandle == NULL)
+    {
+        g_defaultSearchOrderPseudoHandle = dlopen(NULL, RTLD_LAZY);
+    }
+    return g_defaultSearchOrderPseudoHandle;
+}
+#endif

src/native/libs/System.Native/pal_dynamicload.h

@@ -11,3 +11,5 @@ PALEXPORT void* SystemNative_LoadLibrary(const char* filename);
 PALEXPORT void* SystemNative_GetProcAddress(void* handle, const char* symbol);
 
 PALEXPORT void SystemNative_FreeLibrary(void* handle);
+
+PALEXPORT void* SystemNative_GetDefaultSearchOrderPseudoHandle(void);

src/tests/Common/CoreCLRTestLibrary/Utilities.cs

@@ -59,6 +59,7 @@ public static bool Verbose
         }
 
         public static bool IsX86 => (RuntimeInformation.ProcessArchitecture == Architecture.X86);
+        public static bool IsNotX86 => !IsX86;
         public static bool IsX64 => (RuntimeInformation.ProcessArchitecture == Architecture.X64);
         public static bool IsArm => (RuntimeInformation.ProcessArchitecture == Architecture.Arm);
         public static bool IsArm64 => (RuntimeInformation.ProcessArchitecture == Architecture.Arm64);

src/tests/Interop/NativeLibrary/API/GetLibraryExportTests.cs

@@ -0,0 +1,96 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+using System;
+using System.Diagnostics;
+using System.IO;
+using System.Reflection;
+using System.Runtime.InteropServices;
+using Xunit;
+using static TestHelpers;
+
+class GetLibraryExportTests : IDisposable
+{
+    private readonly IntPtr handle;
+
+    public GetLibraryExportTests()
+    {
+        handle = NativeLibrary.Load(NativeLibraryToLoad.GetFullPath());
+    }
+
+    [ConditionalFact(typeof(TestLibrary.Utilities), nameof(TestLibrary.Utilities.IsX86))]
+    public void GetValidExport_ManualMangling()
+    {
+        EXPECT(GetLibraryExport(handle, "_NativeSum@8"));
+        EXPECT(TryGetLibraryExport(handle, "_NativeSum@8"));
+    }
+
+    [ConditionalFact(typeof(TestLibrary.Utilities), nameof(TestLibrary.Utilities.IsNotX86))]
+    public void GetValidExport()
+    {
+        EXPECT(GetLibraryExport(handle, "NativeSum"));
+        EXPECT(TryGetLibraryExport(handle, "NativeSum"));
+    }
+
+    [Fact]
+    public void NullHandle()
+    {
+        EXPECT(GetLibraryExport(IntPtr.Zero, "NativeSum"), TestResult.ArgumentNull);
+        EXPECT(TryGetLibraryExport(IntPtr.Zero, "NativeSum"), TestResult.ArgumentNull);
+    }
+
+    [Fact]
+    public void NullExport()
+    {
+        EXPECT(GetLibraryExport(handle, null), TestResult.ArgumentNull);
+        EXPECT(TryGetLibraryExport(handle, null), TestResult.ArgumentNull);
+    }
+
+    [Fact]
+    public void ExportDoesNotExist()
+    {
+        EXPECT(GetLibraryExport(handle, "NonNativeSum"), TestResult.EntryPointNotFound);
+        EXPECT(TryGetLibraryExport(handle, "NonNativeSum"), TestResult.ReturnFailure);
+    }
+
+
+    public void Dispose() => NativeLibrary.Free(handle);
+
+    static TestResult GetLibraryExport(IntPtr handle, string name)
+    {
+        return Run(() => {
+            IntPtr address = NativeLibrary.GetExport(handle, name);
+            if (address == IntPtr.Zero)
+                return TestResult.ReturnNull;
+            if (RunExportedFunction(address, 1, 1) != 2)
+                return TestResult.IncorrectEvaluation;
+            return TestResult.Success;
+        });
+    }
+
+    static TestResult TryGetLibraryExport(IntPtr handle, string name)
+    {
+        return Run(() => {
+            IntPtr address = IntPtr.Zero;
+            bool success = NativeLibrary.TryGetExport(handle, name, out address);
+            if (!success)
+                return TestResult.ReturnFailure;
+            if (address == IntPtr.Zero)
+                return TestResult.ReturnNull;
+            if (RunExportedFunction(address, 1, 1) != 2)
+                return TestResult.IncorrectEvaluation;
+            return TestResult.Success;
+        });
+    }
+
+    private static unsafe int RunExportedFunction(IntPtr address, int arg1, int arg2)
+    {
+        // We use a delegate here instead of a function pointer to avoid hitting issues
+        // where Mono AOT doesn't generate the managed->native wrapper and then fails
+        // when in AOT-only mode.
+        NativeFunctionWrapper wrapper = Marshal.GetDelegateForFunctionPointer<NativeFunctionWrapper>(address);
+        return wrapper(arg1, arg2);
+    }
+
+    [UnmanagedFunctionPointer(CallingConvention.Winapi)]
+    private delegate int NativeFunctionWrapper(int arg1, int arg2);
+}