1 files changed, 164 insertions, 0 deletions
diff --git a/ARMeilleure/Translation/JitUnwindWindows.cs b/ARMeilleure/Translation/JitUnwindWindows.cs
new file mode 100644
index 00000000..108dc2c5
--- /dev/null
+++ b/ARMeilleure/Translation/JitUnwindWindows.cs
@@ -0,0 +1,164 @@
+using ARMeilleure.IntermediateRepresentation;
+using System;
+using System.Runtime.InteropServices;
+
+namespace ARMeilleure.Translation
+{
+    static class JitUnwindWindows
+    {
+        private const int MaxUnwindCodesArraySize = 9 + 10 * 2 + 3;
+
+        private struct RuntimeFunction
+        {
+            public uint BeginAddress;
+            public uint EndAddress;
+            public uint UnwindData;
+        }
+
+        private struct UnwindInfo
+        {
+            public byte VersionAndFlags;
+            public byte SizeOfProlog;
+            public byte CountOfUnwindCodes;
+            public byte FrameRegister;
+            public unsafe fixed ushort UnwindCodes[MaxUnwindCodesArraySize];
+        }
+
+        private enum UnwindOperation
+        {
+            PushNonvol    = 0,
+            AllocLarge    = 1,
+            AllocSmall    = 2,
+            SetFpreg      = 3,
+            SaveNonvol    = 4,
+            SaveNonvolFar = 5,
+            SaveXmm128    = 8,
+            SaveXmm128Far = 9,
+            PushMachframe = 10
+        }
+
+        private unsafe delegate RuntimeFunction* GetRuntimeFunctionCallback(ulong controlPc, IntPtr context);
+
+        [DllImport("kernel32.dll", CharSet = CharSet.Unicode)]
+        private static unsafe extern bool RtlInstallFunctionTableCallback(
+            ulong                      tableIdentifier,
+            ulong                      baseAddress,
+            uint                       length,
+            GetRuntimeFunctionCallback callback,
+            IntPtr                     context,
+            string                     outOfProcessCallbackDll);
+
+        private static GetRuntimeFunctionCallback _getRuntimeFunctionCallback;
+
+        private static int _sizeOfRuntimeFunction;
+
+        private unsafe static RuntimeFunction* _runtimeFunction;
+
+        private unsafe static UnwindInfo* _unwindInfo;
+
+        public static void InstallFunctionTableHandler(IntPtr codeCachePointer, uint codeCacheLength)
+        {
+            ulong codeCachePtr = (ulong)codeCachePointer.ToInt64();
+
+            _sizeOfRuntimeFunction = Marshal.SizeOf<RuntimeFunction>();
+
+            bool result;
+
+            unsafe
+            {
+                _runtimeFunction = (RuntimeFunction*)codeCachePointer;
+
+                _unwindInfo = (UnwindInfo*)(codeCachePointer + _sizeOfRuntimeFunction);
+
+                _getRuntimeFunctionCallback = new GetRuntimeFunctionCallback(FunctionTableHandler);
+
+                result = RtlInstallFunctionTableCallback(
+                    codeCachePtr | 3,
+                    codeCachePtr,
+                    codeCacheLength,
+                    _getRuntimeFunctionCallback,
+                    codeCachePointer,
+                    null);
+            }
+
+            if (!result)
+            {
+                throw new InvalidOperationException("Failure installing function table callback.");
+            }
+        }
+
+        private static unsafe RuntimeFunction* FunctionTableHandler(ulong controlPc, IntPtr context)
+        {
+            int offset = (int)((long)controlPc - context.ToInt64());
+
+            if (!JitCache.TryFind(offset, out JitCacheEntry funcEntry))
+            {
+                // Not found.
+                return null;
+            }
+
+            var unwindInfo = funcEntry.UnwindInfo;
+
+            int codeIndex = 0;
+
+            int spOffset = unwindInfo.FixedAllocSize;
+
+            foreach (var entry in unwindInfo.PushEntries)
+            {
+                if (entry.Type == RegisterType.Vector)
+                {
+                    spOffset -= 16;
+                }
+            }
+
+            for (int index = unwindInfo.PushEntries.Length - 1; index >= 0; index--)
+            {
+                var entry = unwindInfo.PushEntries[index];
+
+                if (entry.Type == RegisterType.Vector)
+                {
+                    ushort uwop = PackUwop(UnwindOperation.SaveXmm128, entry.StreamEndOffset, entry.Index);
+
+                    _unwindInfo->UnwindCodes[codeIndex++] = uwop;
+                    _unwindInfo->UnwindCodes[codeIndex++] = (ushort)spOffset;
+
+                    spOffset += 16;
+                }
+            }
+
+            _unwindInfo->UnwindCodes[0] = PackUwop(UnwindOperation.AllocLarge, unwindInfo.PrologueSize, 1);
+            _unwindInfo->UnwindCodes[1] = (ushort)(unwindInfo.FixedAllocSize >> 0);
+            _unwindInfo->UnwindCodes[2] = (ushort)(unwindInfo.FixedAllocSize >> 16);
+
+            codeIndex += 3;
+
+            for (int index = unwindInfo.PushEntries.Length - 1; index >= 0; index--)
+            {
+                var entry = unwindInfo.PushEntries[index];
+
+                if (entry.Type == RegisterType.Integer)
+                {
+                    ushort uwop = PackUwop(UnwindOperation.PushNonvol, entry.StreamEndOffset, entry.Index);
+
+                    _unwindInfo->UnwindCodes[codeIndex++] = uwop;
+                }
+            }
+
+            _unwindInfo->VersionAndFlags    = 1;
+            _unwindInfo->SizeOfProlog       = (byte)unwindInfo.PrologueSize;
+            _unwindInfo->CountOfUnwindCodes = (byte)codeIndex;
+            _unwindInfo->FrameRegister      = 0;
+
+            _runtimeFunction->BeginAddress = (uint)funcEntry.Offset;
+            _runtimeFunction->EndAddress   = (uint)(funcEntry.Offset + funcEntry.Size);
+            _runtimeFunction->UnwindData   = (uint)_sizeOfRuntimeFunction;
+
+            return _runtimeFunction;
+        }
+
+        private static ushort PackUwop(UnwindOperation uwop, int prologOffset, int opInfo)
+        {
+            return (ushort)(prologOffset | ((int)uwop << 8) | (opInfo << 12));
+        }
+    }
+}
+\ No newline at end of file