Opentk/Source/OpenTK/Platform/MacOS/NS.cs

172 lines
5.8 KiB
C#
Raw Normal View History

#region License
//
// NS.cs
//
// Author:
// Stefanos A. <stapostol@gmail.com>
//
// Copyright (c) 2006-2013 Stefanos Apostolopoulos
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
#endregion
using System;
using System.Runtime.InteropServices;
namespace OpenTK.Platform.MacOS
{
[Flags]
enum AddImageFlags
{
ReturnOnError = 1,
WithSearching = 2,
ReturnOnlyIfLoaded = 4
}
[Flags]
enum SymbolLookupFlags
{
Bind = 0,
BindNow = 1,
BindFully = 2,
ReturnOnError = 4
}
internal class NS
{
const string Library = "libdl.dylib";
[DllImport(Library, EntryPoint = "NSAddImage")]
internal static extern IntPtr AddImage(string s, AddImageFlags flags);
[DllImport(Library, EntryPoint = "NSAddressOfSymbol")]
internal static extern IntPtr AddressOfSymbol(IntPtr symbol);
[DllImport(Library, EntryPoint = "NSIsSymbolNameDefined")]
internal static extern bool IsSymbolNameDefined(string s);
[DllImport(Library, EntryPoint = "NSIsSymbolNameDefined")]
internal static extern bool IsSymbolNameDefined(IntPtr s);
[DllImport(Library, EntryPoint = "NSLookupAndBindSymbol")]
internal static extern IntPtr LookupAndBindSymbol(string s);
[DllImport(Library, EntryPoint = "NSLookupAndBindSymbol")]
internal static extern IntPtr LookupAndBindSymbol(IntPtr s);
[DllImport(Library, EntryPoint = "NSLookupSymbolInImage")]
internal static extern IntPtr LookupSymbolInImage(IntPtr image, IntPtr symbolName, SymbolLookupFlags options);
// Unfortunately, these are slower even if they are more
// portable and simpler to use.
2014-04-18 22:30:50 +02:00
[DllImport(Library)]
internal static extern IntPtr dlopen(String fileName, int flags);
2014-04-18 22:30:50 +02:00
[DllImport(Library)]
internal static extern int dlclose(IntPtr handle);
[DllImport (Library)]
internal static extern IntPtr dlsym (IntPtr handle, string symbol);
2014-04-18 22:30:50 +02:00
[DllImport (Library)]
internal static extern IntPtr dlsym (IntPtr handle, IntPtr symbol);
public static IntPtr GetAddress(string function)
{
// Instead of allocating and combining strings in managed memory
// we do that directly in unmanaged memory. This way, we avoid
// 2 string allocations every time this function is called.
// must add a '_' prefix and null-terminate the function name,
// hence we allocate +2 bytes
IntPtr ptr = Marshal.AllocHGlobal(function.Length + 2);
try
{
Marshal.WriteByte(ptr, (byte)'_');
for (int i = 0; i < function.Length; i++)
{
Marshal.WriteByte(ptr, i + 1, (byte)function[i]);
}
Marshal.WriteByte(ptr, function.Length + 1, 0); // null-terminate
IntPtr symbol = GetAddressInternal(ptr);
return symbol;
}
finally
{
Marshal.FreeHGlobal(ptr);
}
}
public static IntPtr GetAddress(IntPtr function)
{
unsafe
{
const int max = 64;
byte* symbol = stackalloc byte[max];
byte* ptr = symbol;
byte* cur = (byte*)function.ToPointer();
int i = 0;
*ptr++ = (byte)'_';
while (*cur != 0 && ++i < max)
{
*ptr++ = *cur++;
}
if (i >= max - 1)
{
throw new NotSupportedException(String.Format(
"Function {0} is too long. Please report a bug at https://github.com/opentk/issues/issues",
Marshal.PtrToStringAnsi(function)));
}
return GetAddressInternal(new IntPtr(symbol));
}
}
static IntPtr GetAddressInternal(IntPtr function)
{
IntPtr symbol = IntPtr.Zero;
if (IsSymbolNameDefined(function))
{
symbol = LookupAndBindSymbol(function);
if (symbol != IntPtr.Zero)
symbol = AddressOfSymbol(symbol);
}
return symbol;
}
2014-04-18 22:30:50 +02:00
public static IntPtr GetSymbol(IntPtr handle, string symbol)
{
return dlsym(handle, symbol);
}
public static IntPtr GetSymbol(IntPtr handle, IntPtr symbol)
{
return dlsym(handle, symbol);
}
2014-04-18 22:30:50 +02:00
public static IntPtr LoadLibrary(string fileName)
{
const int RTLD_NOW = 2;
return dlopen(fileName, RTLD_NOW);
}
public static void FreeLibrary(IntPtr handle)
{
dlclose(handle);
}
}
}