public NetSafeLibHandle(string libPath) : base(IntPtr.Zero, true)
{
// [Reference]
// https://docs.microsoft.com/en-US/dotnet/api/system.runtime.interopservices.dllimportsearchpath?view=netstandard-2.0
// https://docs.microsoft.com/en-us/windows/win32/dlls/dynamic-link-library-search-order
// https://docs.microsoft.com/ko-kr/windows/win32/api/libloaderapi/nf-libloaderapi-loadlibraryexw
// https://docs.microsoft.com/ko-kr/windows/win32/api/libloaderapi/nf-libloaderapi-loadlibraryw
// https://github.com/dotnet/runtime/blob/master/src/coreclr/src/vm/dllimport.cpp (LocalLoadLibraryHelper, LoadLibraryFromPath)
// https://github.com/dotnet/runtime/blob/master/src/coreclr/src/inc/utilcode.h (GetLoadWithAlteredSearchPathFlag)
// It looks like DllImportSearchPath enum is connected to LoadLibraryEx flags.
// 1. Flag larger than 256 is directly mapped to LoadLibraryEx flags.
// - 256: UseDllDirectoryForDependencies <-> LOAD_LIBRARY_SEARCH_DLL_LOAD_DIR
// - 512: ApplicationDirectory <-> LOAD_LIBRARY_SEARCH_APPLICATION_DIR
// - 1024: UserDirectories <-> LOAD_LIBRARY_SEARCH_USER_DIRS
// - 2048: System32 <-> LOAD_LIBRARY_SEARCH_SYSTEM32
// - 4096: SafeDirectories <-> LOAD_LIBRARY_SEARCH_DEFAULT_DIRS
// 2. Flag smaller then 256 is loosely connected to LoadLibraryEx flags.
// - 0, 8: LegacyBehavior <-> LOAD_WITH_ALTERED_SEARCH_PATH(?)
// - 2, 8: AssemblyDirectory <-> LOAD_WITH_ALTERED_SEARCH_PATH(?)
// 3. (Important, Undocumented?) From the function LocalLoadLibraryHelper():
// Flag smaller than 256 and larger than 256 look like mutually exclusive to each others.
// Flag larger then 256 has priority over smaller than 256.
const DllImportSearchPath searchPaths = DllImportSearchPath.AssemblyDirectory;
handle = NativeLibrary.Load(libPath, Assembly.GetExecutingAssembly(), searchPaths);
}
private static string GetCApiVersion()
{
unsafe
{
const DllImportSearchPath dllImportSearchPath = DllImportSearchPath.LegacyBehavior
| DllImportSearchPath.AssemblyDirectory
| DllImportSearchPath.SafeDirectories
| DllImportSearchPath.System32
| DllImportSearchPath.UserDirectories
| DllImportSearchPath.ApplicationDirectory
| DllImportSearchPath.UseDllDirectoryForDependencies;
var handle = NativeLibrary.Load(DllName, Assembly.GetExecutingAssembly(), dllImportSearchPath);
var freeString = (delegate * unmanaged[Cdecl] < nint, void >)NativeLibrary.GetExport(handle, "FreeString");
var getCApiVersion =
(delegate * unmanaged[Cdecl] < int *, nint >)NativeLibrary.GetExport(handle, "GetCApiVersion");
var size = 0;
var str = getCApiVersion(&size);
var stringResult = Marshal.PtrToStringUTF8(str, size);
freeString(str);
return(stringResult);
}
}
private static void GetDllImportSearchPathFlags(Assembly callingAssembly, out int searchPathFlags, out bool searchAssemblyDirectory)
{
DllImportSearchPath searchPath = DefaultDllImportSearchPath;
foreach (CustomAttributeData cad in callingAssembly.CustomAttributes)
{
if (cad.AttributeType == typeof(DefaultDllImportSearchPathsAttribute))
{
searchPath = (DllImportSearchPath)cad.ConstructorArguments[0].Value;
}
}
searchPathFlags = (int)(searchPath & ~DllImportSearchPath.AssemblyDirectory);
searchAssemblyDirectory = (searchPath & DllImportSearchPath.AssemblyDirectory) != 0;
}
private static Type CreateWrapperType(Type delegateType,
DllImportAttribute dllImportAttribute,
DllImportSearchPath dllImportSearchPath)
{
TypeBuilder typeBuilder = moduleBuilder.DefineType(
"PInvokeDelegateFactoryInternalWrapperType" + wrapperTypes.Count);
MethodInfo methodInfo = delegateType.GetMethod("Invoke");
ParameterInfo[] parameterInfos = methodInfo.GetParameters();
int parameterCount = parameterInfos.GetLength(0);
Type[] parameterTypes = new Type[parameterCount];
for (int i = 0; i < parameterCount; i++)
{
parameterTypes[i] = parameterInfos[i].ParameterType;
}
MethodBuilder methodBuilder = typeBuilder.DefinePInvokeMethod(
dllImportAttribute.EntryPoint, dllImportAttribute.Value,
MethodAttributes.Public | MethodAttributes.Static |
MethodAttributes.PinvokeImpl, CallingConventions.Standard,
methodInfo.ReturnType, parameterTypes,
dllImportAttribute.CallingConvention,
dllImportAttribute.CharSet);
methodBuilder.SetCustomAttribute(new CustomAttributeBuilder(
typeof(DefaultDllImportSearchPathsAttribute).GetConstructor(
new Type[] { typeof(DllImportSearchPath) }),
new object[] { dllImportSearchPath }));
foreach (ParameterInfo parameterInfo in parameterInfos)
{
methodBuilder.DefineParameter(parameterInfo.Position + 1,
parameterInfo.Attributes, parameterInfo.Name);
}
if (dllImportAttribute.PreserveSig)
{
methodBuilder.SetImplementationFlags(MethodImplAttributes.PreserveSig);
}
return(typeBuilder.CreateType());
}
public static void CreateDelegate <T>(DllImportAttribute dllImportAttribute,
out T newDelegate, DllImportSearchPath dllImportSearchPath =
DllImportSearchPath.System32) where T : class
{
Type wrapperType;
Pair <DllImportAttribute, Type> key =
new Pair <DllImportAttribute, Type>(dllImportAttribute, typeof(T));
wrapperTypes.TryGetValue(key, out wrapperType);
if (wrapperType == null)
{
wrapperType = CreateWrapperType(typeof(T), dllImportAttribute, dllImportSearchPath);
wrapperTypes.Add(key, wrapperType);
}
newDelegate = Delegate.CreateDelegate(typeof(T), wrapperType,
dllImportAttribute.EntryPoint) as T;
}
public DefaultDllImportSearchPathsAttribute(DllImportSearchPath paths)
{
_paths = paths;
}
public DefaultDllImportSearchPathsAttribute(DllImportSearchPath paths)
{
Paths = paths;
}
internal DefaultDllImportSearchPathsAttribute(DllImportSearchPath paths)
{
_paths = paths;
}
/// <summary>Initializes a new instance of the <see cref="T:System.Runtime.InteropServices.DefaultDllImportSearchPathsAttribute" /> class, specifying the paths to use when searching for the targets of platform invokes. </summary><param name="paths">A bitwise combination of enumeration values that specify the paths that the LoadLibraryEx function searches during platform invokes. </param>
public DefaultDllImportSearchPathsAttribute(DllImportSearchPath paths)
{
throw new NotImplementedException();
}
public void Ctor_Paths(DllImportSearchPath paths)
{
var attribute = new DefaultDllImportSearchPathsAttribute(paths);
Assert.Equal(paths, attribute.Paths);
}
