Add way to attempt a load from Path of the native library

Author: ThadHouse

src/FRC-Utilities/NativeLibraryUtilities/EmbeddedLibraryLoader.cs

@@ -28,6 +28,22 @@ void ILibraryLoader.LoadLibrary(string filename)
             }
         }
 
+        /// <summary>
+        /// Try to load a native library from a path
+        /// </summary>
+        /// <param name="filename"></param>
+        /// <returns></returns>
+        public bool TryLoadLibrary(string filename)
+        {
+            IntPtr dl = dlopen(filename, 2);
+            if (dl != IntPtr.Zero)
+            {
+                NativeLibraryHandle = dl;
+                return true;
+            };
+            return false;
+        }
+
         /// <inheritdoc/>
         IntPtr IFunctionPointerLoader.GetProcAddress(string name)
         {

src/FRC-Utilities/NativeLibraryUtilities/ILibraryLoader.cs

@@ -17,6 +17,14 @@ public interface ILibraryLoader : IFunctionPointerLoader
         /// </summary>
         /// <param name="filename"></param>
         void LoadLibrary(string filename);
+
+        /// <summary>
+        /// Tires to load library from specified file name
+        /// </summary>
+        /// <param name="filename"></param>
+        /// <returns></returns>
+        bool TryLoadLibrary(string filename);
+
         /// <summary>
         /// Unloads the native library
         /// </summary>

src/FRC-Utilities/NativeLibraryUtilities/LinuxLibraryLoader.cs

@@ -31,6 +31,22 @@ void ILibraryLoader.LoadLibrary(string filename)
             }
         }
 
+        /// <summary>
+        /// Try to load a native library from a path
+        /// </summary>
+        /// <param name="filename"></param>
+        /// <returns></returns>
+        public bool TryLoadLibrary(string filename)
+        {
+            IntPtr dl = dlopen(filename, 2);
+            if (dl != IntPtr.Zero)
+            {
+                NativeLibraryHandle = dl;
+                return true;
+            };
+            return false;
+        }
+
         /// <inheritdoc/>
         IntPtr IFunctionPointerLoader.GetProcAddress(string name)
         {

src/FRC-Utilities/NativeLibraryUtilities/MacOsLibraryLoader.cs

@@ -30,6 +30,22 @@ void ILibraryLoader.LoadLibrary(string filename)
             }
         }
 
+        /// <summary>
+        /// Try to load a native library from a path
+        /// </summary>
+        /// <param name="filename"></param>
+        /// <returns></returns>
+        bool ILibraryLoader.TryLoadLibrary(string filename)
+        {
+            IntPtr dl = dlopen(filename, 2);
+            if (dl != IntPtr.Zero)
+            {
+                NativeLibraryHandle = dl;
+                return true;
+            };
+            return false;
+        }
+
         IntPtr IFunctionPointerLoader.GetProcAddress(string name)
         {
             dlerror();

src/FRC-Utilities/NativeLibraryUtilities/NativeLibraryLoader.cs

@@ -168,6 +168,39 @@ public void LoadNativeLibrary<T>(bool directLoad = false, string? extractLocatio
             LoadNativeLibrary<T>(LibraryLoader, m_nativeLibraryName[osType], directLoad, extractLocation);
         }
 
+        /// <summary>
+        /// Try to load a native library directly from a path
+        /// </summary>
+        /// <param name="libraryName"></param>
+        /// <returns></returns>
+        public bool TryLoadNativeLibraryPath(string libraryName)
+        {
+            OsType osType = OsType;
+
+            if (osType == OsType.None)
+                throw new InvalidOperationException(
+                    "OS type is unknown. Must use the overload to manually load the file");
+
+            ILibraryLoader loader = osType switch
+            {
+                OsType.Windows32 => new WindowsLibraryLoader(),
+                OsType.Windows64 => new WindowsLibraryLoader(),
+                OsType.Linux32 => new LinuxLibraryLoader(),
+                OsType.Linux64 => new LinuxLibraryLoader(),
+                OsType.MacOs32 => new MacOsLibraryLoader(),
+                OsType.MacOs64 => new MacOsLibraryLoader(),
+                _ => new EmbeddedLibraryLoader()
+            };
+
+            bool wasLoaded = loader.TryLoadLibrary(libraryName);
+            if (wasLoaded)
+            {
+                LibraryLoader = loader;
+                LibraryLocation = libraryName;
+            }
+            return wasLoaded;
+        }
+
         /// <summary>
         /// Loads a native library with a reflected assembly holding the native libraries
         /// </summary>

src/FRC-Utilities/NativeLibraryUtilities/WindowsLibraryLoader.cs

@@ -1,4 +1,5 @@
 using System;
+using System.ComponentModel;
 using System.IO;
 using System.Runtime.InteropServices;
 using FRC.ILGeneration;
@@ -17,7 +18,29 @@ void ILibraryLoader.LoadLibrary(string filename)
         {
             if (!File.Exists(filename))
                 throw new FileNotFoundException("The file requested to be loaded could not be found");
-            NativeLibraryHandle = LoadLibrary(filename);
+            IntPtr dl = LoadLibrary(filename);
+            if (dl != IntPtr.Zero)
+            {
+                NativeLibraryHandle = dl;
+                return;
+            }
+            throw new Win32Exception(Marshal.GetLastWin32Error());
+        }
+
+        /// <summary>
+        /// Try to load a native library from a path
+        /// </summary>
+        /// <param name="filename"></param>
+        /// <returns></returns>
+        public bool TryLoadLibrary(string filename)
+        {
+            IntPtr dl = LoadLibrary(filename);
+            if (dl != IntPtr.Zero)
+            {
+                NativeLibraryHandle = dl;
+                return true;
+            };
+            return false;
         }
 
         IntPtr IFunctionPointerLoader.GetProcAddress(string name)
@@ -36,7 +59,7 @@ void ILibraryLoader.UnloadLibrary()
             FreeLibrary(NativeLibraryHandle);
         }
 
-        [DllImport("kernel32")]
+        [DllImport("kernel32", SetLastError = true)]
         private static extern IntPtr LoadLibrary(string fileName);
 
         [DllImport("kernel32.dll")]