1 files changed, 188 insertions, 0 deletions
diff --git a/ARMeilleure/Translation/Cache/JitUnwindWindows.cs b/ARMeilleure/Translation/Cache/JitUnwindWindows.cs
new file mode 100644
index 00000000..072c0f51
--- /dev/null
+++ b/ARMeilleure/Translation/Cache/JitUnwindWindows.cs
@@ -0,0 +1,188 @@
+// https://github.com/MicrosoftDocs/cpp-docs/blob/master/docs/build/exception-handling-x64.md
+
+using ARMeilleure.CodeGen.Unwinding;
+using System;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+
+namespace ARMeilleure.Translation.Cache
+{
+    static class JitUnwindWindows
+    {
+        private const int MaxUnwindCodesArraySize = 32; // Must be an even value.
+
+        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 UnwindOp
+        {
+            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, IntPtr workBufferPtr)
+        {
+            ulong codeCachePtr = (ulong)codeCachePointer.ToInt64();
+
+            _sizeOfRuntimeFunction = Marshal.SizeOf<RuntimeFunction>();
+
+            bool result;
+
+            unsafe
+            {
+                _runtimeFunction = (RuntimeFunction*)workBufferPtr;
+
+                _unwindInfo = (UnwindInfo*)(workBufferPtr + _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 CacheEntry funcEntry))
+            {
+                return null; // Not found.
+            }
+
+            var unwindInfo = funcEntry.UnwindInfo;
+
+            int codeIndex = 0;
+
+            for (int index = unwindInfo.PushEntries.Length - 1; index >= 0; index--)
+            {
+                var entry = unwindInfo.PushEntries[index];
+
+                switch (entry.PseudoOp)
+                {
+                    case UnwindPseudoOp.SaveXmm128:
+                    {
+                        int stackOffset = entry.StackOffsetOrAllocSize;
+
+                        Debug.Assert(stackOffset % 16 == 0);
+
+                        if (stackOffset <= 0xFFFF0)
+                        {
+                            _unwindInfo->UnwindCodes[codeIndex++] = PackUnwindOp(UnwindOp.SaveXmm128, entry.PrologOffset, entry.RegIndex);
+                            _unwindInfo->UnwindCodes[codeIndex++] = (ushort)(stackOffset / 16);
+                        }
+                        else
+                        {
+                            _unwindInfo->UnwindCodes[codeIndex++] = PackUnwindOp(UnwindOp.SaveXmm128Far, entry.PrologOffset, entry.RegIndex);
+                            _unwindInfo->UnwindCodes[codeIndex++] = (ushort)(stackOffset >> 0);
+                            _unwindInfo->UnwindCodes[codeIndex++] = (ushort)(stackOffset >> 16);
+                        }
+
+                        break;
+                    }
+
+                    case UnwindPseudoOp.AllocStack:
+                    {
+                        int allocSize = entry.StackOffsetOrAllocSize;
+
+                        Debug.Assert(allocSize % 8 == 0);
+
+                        if (allocSize <= 128)
+                        {
+                            _unwindInfo->UnwindCodes[codeIndex++] = PackUnwindOp(UnwindOp.AllocSmall, entry.PrologOffset, (allocSize / 8) - 1);
+                        }
+                        else if (allocSize <= 0x7FFF8)
+                        {
+                            _unwindInfo->UnwindCodes[codeIndex++] = PackUnwindOp(UnwindOp.AllocLarge, entry.PrologOffset, 0);
+                            _unwindInfo->UnwindCodes[codeIndex++] = (ushort)(allocSize / 8);
+                        }
+                        else
+                        {
+                            _unwindInfo->UnwindCodes[codeIndex++] = PackUnwindOp(UnwindOp.AllocLarge, entry.PrologOffset, 1);
+                            _unwindInfo->UnwindCodes[codeIndex++] = (ushort)(allocSize >> 0);
+                            _unwindInfo->UnwindCodes[codeIndex++] = (ushort)(allocSize >> 16);
+                        }
+
+                        break;
+                    }
+
+                    case UnwindPseudoOp.PushReg:
+                    {
+                        _unwindInfo->UnwindCodes[codeIndex++] = PackUnwindOp(UnwindOp.PushNonvol, entry.PrologOffset, entry.RegIndex);
+
+                        break;
+                    }
+
+                    default: throw new NotImplementedException($"({nameof(entry.PseudoOp)} = {entry.PseudoOp})");
+                }
+            }
+
+            Debug.Assert(codeIndex <= MaxUnwindCodesArraySize);
+
+            _unwindInfo->VersionAndFlags    = 1; // Flags: The function has no handler.
+            _unwindInfo->SizeOfProlog       = (byte)unwindInfo.PrologSize;
+            _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 PackUnwindOp(UnwindOp op, int prologOffset, int opInfo)
+        {
+            return (ushort)(prologOffset | ((int)op << 8) | (opInfo << 12));
+        }
+    }
+}
+\ No newline at end of file