[WIP] Custom Symbol/Library loading logic

AdvancedDLSupport.Tests/Data/Classes/LibraryLoadingOverride.cs

@@ -0,0 +1,51 @@
+//
+//  LibraryLoadingOverride.cs
+//
+//  Copyright (c) 2018 Firwood Software
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU Lesser General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+using System;
+using AdvancedDLSupport.Loaders;
+using JetBrains.Annotations;
+
+#pragma warning disable SA1600, CS1591
+
+namespace AdvancedDLSupport.Tests.Data.Classes
+{
+    internal class LibraryLoadingOverride : ILibraryLoader
+    {
+        private readonly ILibraryLoader _defaultLoader;
+
+        public bool LoadLibraryCalled { get; private set; }
+
+        public LibraryLoadingOverride(ILibraryLoader @default)
+        {
+            _defaultLoader = @default;
+        }
+
+        public IntPtr LoadLibrary([CanBeNull] string path)
+        {
+            LoadLibraryCalled = true;
+
+            return _defaultLoader.LoadLibrary(path);
+        }
+
+        public bool CloseLibrary(IntPtr library)
+        {
+            return _defaultLoader.CloseLibrary(library);
+        }
+    }
+}

AdvancedDLSupport.Tests/Data/Classes/SymbolLoadingOverride.cs

@@ -0,0 +1,46 @@
+//
+//  SymbolLoadingOverride.cs
+//
+//  Copyright (c) 2018 Firwood Software
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU Lesser General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+using System;
+using AdvancedDLSupport.Loaders;
+using JetBrains.Annotations;
+
+#pragma warning disable SA1600, CS1591
+
+namespace AdvancedDLSupport.Tests.Data.Classes
+{
+    internal class SymbolLoadingOverride : ISymbolLoader
+    {
+        private readonly ISymbolLoader _defaultLoader;
+
+        public bool LoadSymbolCalled { get; private set; }
+
+        public SymbolLoadingOverride(ISymbolLoader @default)
+        {
+            _defaultLoader = @default;
+        }
+
+        public IntPtr LoadSymbol(IntPtr library, [NotNull] string symbolName)
+        {
+            LoadSymbolCalled = true;
+
+            return _defaultLoader.LoadSymbol(library, symbolName == "GetString" ? "GetNullString" : symbolName);
+        }
+    }
+}

AdvancedDLSupport.Tests/Data/Interfaces/ICustomLoadingLogicTests.cs

@@ -0,0 +1,30 @@
+//
+//  ICustomLoadingLogicTests.cs
+//
+//  Copyright (c) 2018 Firwood Software
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU Lesser General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#pragma warning disable SA1600, CS1591
+
+namespace AdvancedDLSupport.Tests.Data
+{
+    public interface ICustomLoadingLogicTests
+    {
+        int ReturnsOne();
+
+        int ReturnsTwo();
+    }
+}

AdvancedDLSupport.Tests/Tests/Integration/CustomLoadingLogicTests.cs

@@ -0,0 +1,73 @@
+//
+//  CustomLoadingLogicTests.cs
+//
+//  Copyright (c) 2018 Firwood Software
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU Lesser General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+using AdvancedDLSupport.Tests.Data;
+using AdvancedDLSupport.Tests.Data.Classes;
+using AdvancedDLSupport.Tests.TestBases;
+using Xunit;
+
+#pragma warning disable SA1600, CS1591
+
+namespace AdvancedDLSupport.Tests.Integration
+{
+    public class CustomLoadingLogicTests : LibraryTestBase<IStringLibrary>
+    {
+        private const string LibraryName = "StringTests";
+
+        private LibraryLoadingOverride _libraryLogicOverride;
+        private SymbolLoadingOverride _symbolLogicOverride;
+
+        public CustomLoadingLogicTests()
+            : base(LibraryName)
+        {
+        }
+
+        protected override ImplementationOptions GetImplementationOptions()
+        {
+            return base.GetImplementationOptions() | ImplementationOptions.UseLazyBinding;
+        }
+
+        protected override NativeLibraryBuilder GetImplementationBuilder()
+        {
+            return base.GetImplementationBuilder().WithLibraryLoader(@default =>
+            {
+                _libraryLogicOverride = new LibraryLoadingOverride(@default);
+                return _libraryLogicOverride;
+            }).WithSymbolLoader(@default =>
+            {
+                _symbolLogicOverride = new SymbolLoadingOverride(@default);
+                return _symbolLogicOverride;
+            });
+        }
+
+        [Fact]
+        public void CustomLogicCalled()
+        {
+            Library.GetString();
+            Assert.True(_libraryLogicOverride.LoadLibraryCalled);
+            Assert.True(_symbolLogicOverride.LoadSymbolCalled);
+        }
+
+        [Fact]
+        public void CustomLogicSuccessful()
+        {
+            Assert.Equal(Library.GetString(), Library.GetNullString());
+        }
+    }
+}

AdvancedDLSupport.Tests/c/src/CustomLoadingLogicTests.c

@@ -0,0 +1,11 @@
+#include <stdint.h>
+
+__declspec(dllexport) int32_t ReturnsOne()
+{
+	return 1;
+}
+
+__declspec(dllexport) int32_t ReturnsTwo()
+{
+	return 2;
+}

AdvancedDLSupport/Loaders/ILibraryLoader.cs

@@ -0,0 +1,48 @@
+//
+//  ILibraryLoader.cs
+//
+//  Copyright (c) 2018 Firwood Software
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU Lesser General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+using System;
+using JetBrains.Annotations;
+
+namespace AdvancedDLSupport.Loaders
+{
+    /// <summary>
+    /// Represents a class which can load libraries on a specific platform.
+    /// </summary>
+    public interface ILibraryLoader
+    {
+        /// <summary>
+        /// Load the given library. A null path signifies intent to load the main executable instead of an external
+        /// library.
+        /// </summary>
+        /// <param name="path">The path to the library.</param>
+        /// <returns>A handle to the library. This value carries no intrinsic meaning.</returns>
+        /// <exception cref="LibraryLoadingException">Thrown if the library could not be loaded.</exception>
+        [PublicAPI]
+        IntPtr LoadLibrary([CanBeNull] string path);
+
+        /// <summary>
+        /// Closes the open handle to the given library.
+        /// </summary>
+        /// <param name="library">The handle to the library to close.</param>
+        /// <returns>true if the library was closed successfully; otherwise, false.</returns>
+        [PublicAPI]
+        bool CloseLibrary(IntPtr library);
+    }
+}

AdvancedDLSupport/Loaders/IPlatformLoader.cs

@@ -17,7 +17,6 @@
 //  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 //
 
-using System;
 using JetBrains.Annotations;
 
 namespace AdvancedDLSupport.Loaders
@@ -26,44 +25,7 @@ namespace AdvancedDLSupport.Loaders
     /// Represents a class which can load libraries and symbols on a specific platform.
     /// </summary>
     [PublicAPI]
-    public interface IPlatformLoader
+    public interface IPlatformLoader : ISymbolLoader, ILibraryLoader
     {
-        /// <summary>
-        /// Loads the given symbol name and marshals it into a function delegate.
-        /// </summary>
-        /// <param name="library">The library handle.</param>
-        /// <param name="symbolName">The name of the symbol.</param>
-        /// <typeparam name="T">The delegate type to marshal.</typeparam>
-        /// <returns>A marshalled delegate.</returns>
-        [PublicAPI, NotNull, Pure]
-        T LoadFunction<T>(IntPtr library, [NotNull] string symbolName);
-
-        /// <summary>
-        /// Load the given library. A null path signifies intent to load the main executable instead of an external
-        /// library.
-        /// </summary>
-        /// <param name="path">The path to the library.</param>
-        /// <returns>A handle to the library. This value carries no intrinsic meaning.</returns>
-        /// <exception cref="LibraryLoadingException">Thrown if the library could not be loaded.</exception>
-        [PublicAPI]
-        IntPtr LoadLibrary([CanBeNull] string path);
-
-        /// <summary>
-        /// Load the given symbol.
-        /// </summary>
-        /// <param name="library">The handle to the library in which the symbol exists.</param>
-        /// <param name="symbolName">The name of the symbol to load.</param>
-        /// <exception cref="SymbolLoadingException">Thrown if the symbol could not be loaded.</exception>
-        /// <returns>A handle to the symbol.</returns>
-        [PublicAPI, Pure]
-        IntPtr LoadSymbol(IntPtr library, [NotNull] string symbolName);
-
-        /// <summary>
-        /// Closes the open handle to the given library.
-        /// </summary>
-        /// <param name="library">The handle to the library to close.</param>
-        /// <returns>true if the library was closed successfully; otherwise, false.</returns>
-        [PublicAPI]
-        bool CloseLibrary(IntPtr library);
     }
 }

AdvancedDLSupport/Loaders/ISymbolLoader.cs

@@ -0,0 +1,40 @@
+//
+//  ISymbolLoader.cs
+//
+//  Copyright (c) 2018 Firwood Software
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU Lesser General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+using System;
+using JetBrains.Annotations;
+
+namespace AdvancedDLSupport.Loaders
+{
+    /// <summary>
+    /// Represents a class which can load symbols on a specific platform.
+    /// </summary>
+    public interface ISymbolLoader
+    {
+        /// <summary>
+        /// Load the given symbol.
+        /// </summary>
+        /// <param name="library">The handle to the library in which the symbol exists.</param>
+        /// <param name="symbolName">The name of the symbol to load.</param>
+        /// <exception cref="SymbolLoadingException">Thrown if the symbol could not be loaded.</exception>
+        /// <returns>A handle to the symbol.</returns>
+        [PublicAPI, Pure]
+        IntPtr LoadSymbol(IntPtr library, [NotNull] string symbolName);
+    }
+}

AdvancedDLSupport/Loaders/PlatformLoaderBase.cs

@@ -29,9 +29,10 @@ namespace AdvancedDLSupport.Loaders
     [PublicAPI]
     public abstract class PlatformLoaderBase : IPlatformLoader
     {
-        /// <inheritdoc />
-        public T LoadFunction<T>(IntPtr library, string symbolName) =>
-            Marshal.GetDelegateForFunctionPointer<T>(LoadSymbol(library, symbolName));
+        /// <summary>
+        /// Gets a cached instance of the current platform's default loader.
+        /// </summary>
+        public static IPlatformLoader PlatformLoader { get; } = SelectPlatformLoader();
 
         /// <inheritdoc />
         public IntPtr LoadLibrary(string path) => LoadLibraryInternal(path);
@@ -57,7 +58,7 @@ public T LoadFunction<T>(IntPtr library, string symbolName) =>
         /// <returns>A platform loader for the current platform..</returns>
         /// <exception cref="PlatformNotSupportedException">Thrown if the current platform is not supported.</exception>
         [PublicAPI, NotNull, Pure]
-        public static IPlatformLoader SelectPlatformLoader()
+        private static IPlatformLoader SelectPlatformLoader()
         {
             if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
             {