1 files changed, 117 insertions, 0 deletions
diff --git a/src/inc/win64unwind.h b/src/inc/win64unwind.h
new file mode 100644
index 0000000000..196052aca9
--- /dev/null
+++ b/src/inc/win64unwind.h
@@ -0,0 +1,117 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+#ifndef _WIN64UNWIND_H_
+#define _WIN64UNWIND_H_
+
+//
+// Define AMD64 exception handling structures and function prototypes.
+//
+// Define unwind operation codes.
+//
+
+typedef enum _UNWIND_OP_CODES {
+    UWOP_PUSH_NONVOL = 0,
+    UWOP_ALLOC_LARGE,
+    UWOP_ALLOC_SMALL,
+    UWOP_SET_FPREG,
+    UWOP_SAVE_NONVOL,
+    UWOP_SAVE_NONVOL_FAR,
+    UWOP_EPILOG,
+    UWOP_SPARE_CODE,
+    UWOP_SAVE_XMM128,
+    UWOP_SAVE_XMM128_FAR,
+    UWOP_PUSH_MACHFRAME,
+
+#ifdef PLATFORM_UNIX
+    // UWOP_SET_FPREG_LARGE is a CLR Unix-only extension to the Windows AMD64 unwind codes.
+    // It is not part of the standard Windows AMD64 unwind codes specification.
+    // UWOP_SET_FPREG allows for a maximum of a 240 byte offset between RSP and the
+    // frame pointer, when the frame pointer is established. UWOP_SET_FPREG_LARGE
+    // has a 32-bit range scaled by 16. When UWOP_SET_FPREG_LARGE is used,
+    // UNWIND_INFO.FrameRegister must be set to the frame pointer register, and
+    // UNWIND_INFO.FrameOffset must be set to 15 (its maximum value). UWOP_SET_FPREG_LARGE
+    // is followed by two UNWIND_CODEs that are combined to form a 32-bit offset (the same
+    // as UWOP_SAVE_NONVOL_FAR). This offset is then scaled by 16. The result must be less
+    // than 2^32 (that is, the top 4 bits of the unscaled 32-bit number must be zero). This
+    // result is used as the frame pointer register offset from RSP at the time the frame pointer
+    // is established. Either UWOP_SET_FPREG or UWOP_SET_FPREG_LARGE can be used, but not both.
+
+    UWOP_SET_FPREG_LARGE,
+#endif // PLATFORM_UNIX
+} UNWIND_OP_CODES, *PUNWIND_OP_CODES;
+
+static const UCHAR UnwindOpExtraSlotTable[] = {
+    0,          // UWOP_PUSH_NONVOL
+    1,          // UWOP_ALLOC_LARGE (or 3, special cased in lookup code)
+    0,          // UWOP_ALLOC_SMALL
+    0,          // UWOP_SET_FPREG
+    1,          // UWOP_SAVE_NONVOL
+    2,          // UWOP_SAVE_NONVOL_FAR
+    1,          // UWOP_EPILOG
+    2,          // UWOP_SPARE_CODE      // previously 64-bit UWOP_SAVE_XMM_FAR
+    1,          // UWOP_SAVE_XMM128
+    2,          // UWOP_SAVE_XMM128_FAR
+    0,          // UWOP_PUSH_MACHFRAME
+
+#ifdef PLATFORM_UNIX
+    2,          // UWOP_SET_FPREG_LARGE
+#endif // PLATFORM_UNIX
+};
+
+//
+// Define unwind code structure.
+//
+
+typedef union _UNWIND_CODE {
+    struct {
+        UCHAR CodeOffset;
+        UCHAR UnwindOp : 4;
+        UCHAR OpInfo : 4;
+    };
+
+    struct {
+        UCHAR OffsetLow;
+        UCHAR UnwindOp : 4;
+        UCHAR OffsetHigh : 4;
+    } EpilogueCode;
+
+    USHORT FrameOffset;
+} UNWIND_CODE, *PUNWIND_CODE;
+
+//
+// Define unwind information flags.
+//
+
+#define UNW_FLAG_NHANDLER 0x0
+#define UNW_FLAG_EHANDLER 0x1
+#define UNW_FLAG_UHANDLER 0x2
+#define UNW_FLAG_CHAININFO 0x4
+
+typedef struct _UNWIND_INFO {
+    UCHAR Version : 3;
+    UCHAR Flags : 5;
+    UCHAR SizeOfProlog;
+    UCHAR CountOfUnwindCodes;
+    UCHAR FrameRegister : 4;
+    UCHAR FrameOffset : 4;
+    UNWIND_CODE UnwindCode[1];
+
+//
+// The unwind codes are followed by an optional DWORD aligned field that
+// contains the exception handler address or the address of chained unwind
+// information. If an exception handler address is specified, then it is
+// followed by the language specified exception handler data.
+//
+//  union {
+//      ULONG ExceptionHandler;
+//      ULONG FunctionEntry;
+//  };
+//
+//  ULONG ExceptionData[];
+//
+
+} UNWIND_INFO, *PUNWIND_INFO;
+
+#endif // _WIN64UNWIND_H_