Vendor import of llvm-project main llvmorg-14-init-10186-gff7f2cfa959b.vendor/llvm-project/llvmorg-14-init-10186-gff7f2cfa959b

29 files changed, 938 insertions, 493 deletions

diff --git a/libunwind/include/__libunwind_config.h b/libunwind/include/__libunwind_config.h
index a50ba053884b..221980a24aeb 100644
--- a/libunwind/include/__libunwind_config.h
+++ b/libunwind/include/__libunwind_config.h
@@ -1,4 +1,4 @@
-//===------------------------- __libunwind_config.h -----------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
diff --git a/libunwind/include/libunwind.h b/libunwind/include/libunwind.h
index 0feecd7bd6fc..e187ee27b0db 100644
--- a/libunwind/include/libunwind.h
+++ b/libunwind/include/libunwind.h
@@ -1,4 +1,4 @@
-//===---------------------------- libunwind.h -----------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -493,77 +493,150 @@ enum {
 
 // 64-bit ARM64 registers
 enum {
-  UNW_ARM64_X0 = 0,
-  UNW_ARM64_X1 = 1,
-  UNW_ARM64_X2 = 2,
-  UNW_ARM64_X3 = 3,
-  UNW_ARM64_X4 = 4,
-  UNW_ARM64_X5 = 5,
-  UNW_ARM64_X6 = 6,
-  UNW_ARM64_X7 = 7,
-  UNW_ARM64_X8 = 8,
-  UNW_ARM64_X9 = 9,
-  UNW_ARM64_X10 = 10,
-  UNW_ARM64_X11 = 11,
-  UNW_ARM64_X12 = 12,
-  UNW_ARM64_X13 = 13,
-  UNW_ARM64_X14 = 14,
-  UNW_ARM64_X15 = 15,
-  UNW_ARM64_X16 = 16,
-  UNW_ARM64_X17 = 17,
-  UNW_ARM64_X18 = 18,
-  UNW_ARM64_X19 = 19,
-  UNW_ARM64_X20 = 20,
-  UNW_ARM64_X21 = 21,
-  UNW_ARM64_X22 = 22,
-  UNW_ARM64_X23 = 23,
-  UNW_ARM64_X24 = 24,
-  UNW_ARM64_X25 = 25,
-  UNW_ARM64_X26 = 26,
-  UNW_ARM64_X27 = 27,
-  UNW_ARM64_X28 = 28,
-  UNW_ARM64_X29 = 29,
-  UNW_ARM64_FP = 29,
-  UNW_ARM64_X30 = 30,
-  UNW_ARM64_LR = 30,
-  UNW_ARM64_X31 = 31,
-  UNW_ARM64_SP = 31,
-  UNW_ARM64_PC = 32,
-  // reserved block
-  UNW_ARM64_RA_SIGN_STATE = 34,
+  UNW_AARCH64_X0 = 0,
+  UNW_AARCH64_X1 = 1,
+  UNW_AARCH64_X2 = 2,
+  UNW_AARCH64_X3 = 3,
+  UNW_AARCH64_X4 = 4,
+  UNW_AARCH64_X5 = 5,
+  UNW_AARCH64_X6 = 6,
+  UNW_AARCH64_X7 = 7,
+  UNW_AARCH64_X8 = 8,
+  UNW_AARCH64_X9 = 9,
+  UNW_AARCH64_X10 = 10,
+  UNW_AARCH64_X11 = 11,
+  UNW_AARCH64_X12 = 12,
+  UNW_AARCH64_X13 = 13,
+  UNW_AARCH64_X14 = 14,
+  UNW_AARCH64_X15 = 15,
+  UNW_AARCH64_X16 = 16,
+  UNW_AARCH64_X17 = 17,
+  UNW_AARCH64_X18 = 18,
+  UNW_AARCH64_X19 = 19,
+  UNW_AARCH64_X20 = 20,
+  UNW_AARCH64_X21 = 21,
+  UNW_AARCH64_X22 = 22,
+  UNW_AARCH64_X23 = 23,
+  UNW_AARCH64_X24 = 24,
+  UNW_AARCH64_X25 = 25,
+  UNW_AARCH64_X26 = 26,
+  UNW_AARCH64_X27 = 27,
+  UNW_AARCH64_X28 = 28,
+  UNW_AARCH64_X29 = 29,
+  UNW_AARCH64_FP = 29,
+  UNW_AARCH64_X30 = 30,
+  UNW_AARCH64_LR = 30,
+  UNW_AARCH64_X31 = 31,
+  UNW_AARCH64_SP = 31,
+  UNW_AARCH64_PC = 32,
+
   // reserved block
-  UNW_ARM64_D0 = 64,
-  UNW_ARM64_D1 = 65,
-  UNW_ARM64_D2 = 66,
-  UNW_ARM64_D3 = 67,
-  UNW_ARM64_D4 = 68,
-  UNW_ARM64_D5 = 69,
-  UNW_ARM64_D6 = 70,
-  UNW_ARM64_D7 = 71,
-  UNW_ARM64_D8 = 72,
-  UNW_ARM64_D9 = 73,
-  UNW_ARM64_D10 = 74,
-  UNW_ARM64_D11 = 75,
-  UNW_ARM64_D12 = 76,
-  UNW_ARM64_D13 = 77,
-  UNW_ARM64_D14 = 78,
-  UNW_ARM64_D15 = 79,
-  UNW_ARM64_D16 = 80,
-  UNW_ARM64_D17 = 81,
-  UNW_ARM64_D18 = 82,
-  UNW_ARM64_D19 = 83,
-  UNW_ARM64_D20 = 84,
-  UNW_ARM64_D21 = 85,
-  UNW_ARM64_D22 = 86,
-  UNW_ARM64_D23 = 87,
-  UNW_ARM64_D24 = 88,
-  UNW_ARM64_D25 = 89,
-  UNW_ARM64_D26 = 90,
-  UNW_ARM64_D27 = 91,
-  UNW_ARM64_D28 = 92,
-  UNW_ARM64_D29 = 93,
-  UNW_ARM64_D30 = 94,
-  UNW_ARM64_D31 = 95,
+  UNW_AARCH64_RA_SIGN_STATE = 34,
+
+  // FP/vector registers
+  UNW_AARCH64_V0 = 64,
+  UNW_AARCH64_V1 = 65,
+  UNW_AARCH64_V2 = 66,
+  UNW_AARCH64_V3 = 67,
+  UNW_AARCH64_V4 = 68,
+  UNW_AARCH64_V5 = 69,
+  UNW_AARCH64_V6 = 70,
+  UNW_AARCH64_V7 = 71,
+  UNW_AARCH64_V8 = 72,
+  UNW_AARCH64_V9 = 73,
+  UNW_AARCH64_V10 = 74,
+  UNW_AARCH64_V11 = 75,
+  UNW_AARCH64_V12 = 76,
+  UNW_AARCH64_V13 = 77,
+  UNW_AARCH64_V14 = 78,
+  UNW_AARCH64_V15 = 79,
+  UNW_AARCH64_V16 = 80,
+  UNW_AARCH64_V17 = 81,
+  UNW_AARCH64_V18 = 82,
+  UNW_AARCH64_V19 = 83,
+  UNW_AARCH64_V20 = 84,
+  UNW_AARCH64_V21 = 85,
+  UNW_AARCH64_V22 = 86,
+  UNW_AARCH64_V23 = 87,
+  UNW_AARCH64_V24 = 88,
+  UNW_AARCH64_V25 = 89,
+  UNW_AARCH64_V26 = 90,
+  UNW_AARCH64_V27 = 91,
+  UNW_AARCH64_V28 = 92,
+  UNW_AARCH64_V29 = 93,
+  UNW_AARCH64_V30 = 94,
+  UNW_AARCH64_V31 = 95,
+
+  // Compatibility aliases
+  UNW_ARM64_X0 = UNW_AARCH64_X0,
+  UNW_ARM64_X1 = UNW_AARCH64_X1,
+  UNW_ARM64_X2 = UNW_AARCH64_X2,
+  UNW_ARM64_X3 = UNW_AARCH64_X3,
+  UNW_ARM64_X4 = UNW_AARCH64_X4,
+  UNW_ARM64_X5 = UNW_AARCH64_X5,
+  UNW_ARM64_X6 = UNW_AARCH64_X6,
+  UNW_ARM64_X7 = UNW_AARCH64_X7,
+  UNW_ARM64_X8 = UNW_AARCH64_X8,
+  UNW_ARM64_X9 = UNW_AARCH64_X9,
+  UNW_ARM64_X10 = UNW_AARCH64_X10,
+  UNW_ARM64_X11 = UNW_AARCH64_X11,
+  UNW_ARM64_X12 = UNW_AARCH64_X12,
+  UNW_ARM64_X13 = UNW_AARCH64_X13,
+  UNW_ARM64_X14 = UNW_AARCH64_X14,
+  UNW_ARM64_X15 = UNW_AARCH64_X15,
+  UNW_ARM64_X16 = UNW_AARCH64_X16,
+  UNW_ARM64_X17 = UNW_AARCH64_X17,
+  UNW_ARM64_X18 = UNW_AARCH64_X18,
+  UNW_ARM64_X19 = UNW_AARCH64_X19,
+  UNW_ARM64_X20 = UNW_AARCH64_X20,
+  UNW_ARM64_X21 = UNW_AARCH64_X21,
+  UNW_ARM64_X22 = UNW_AARCH64_X22,
+  UNW_ARM64_X23 = UNW_AARCH64_X23,
+  UNW_ARM64_X24 = UNW_AARCH64_X24,
+  UNW_ARM64_X25 = UNW_AARCH64_X25,
+  UNW_ARM64_X26 = UNW_AARCH64_X26,
+  UNW_ARM64_X27 = UNW_AARCH64_X27,
+  UNW_ARM64_X28 = UNW_AARCH64_X28,
+  UNW_ARM64_X29 = UNW_AARCH64_X29,
+  UNW_ARM64_FP = UNW_AARCH64_FP,
+  UNW_ARM64_X30 = UNW_AARCH64_X30,
+  UNW_ARM64_LR = UNW_AARCH64_LR,
+  UNW_ARM64_X31 = UNW_AARCH64_X31,
+  UNW_ARM64_SP = UNW_AARCH64_SP,
+  UNW_ARM64_PC = UNW_AARCH64_PC,
+  UNW_ARM64_RA_SIGN_STATE = UNW_AARCH64_RA_SIGN_STATE,
+  UNW_ARM64_D0 = UNW_AARCH64_V0,
+  UNW_ARM64_D1 = UNW_AARCH64_V1,
+  UNW_ARM64_D2 = UNW_AARCH64_V2,
+  UNW_ARM64_D3 = UNW_AARCH64_V3,
+  UNW_ARM64_D4 = UNW_AARCH64_V4,
+  UNW_ARM64_D5 = UNW_AARCH64_V5,
+  UNW_ARM64_D6 = UNW_AARCH64_V6,
+  UNW_ARM64_D7 = UNW_AARCH64_V7,
+  UNW_ARM64_D8 = UNW_AARCH64_V8,
+  UNW_ARM64_D9 = UNW_AARCH64_V9,
+  UNW_ARM64_D10 = UNW_AARCH64_V10,
+  UNW_ARM64_D11 = UNW_AARCH64_V11,
+  UNW_ARM64_D12 = UNW_AARCH64_V12,
+  UNW_ARM64_D13 = UNW_AARCH64_V13,
+  UNW_ARM64_D14 = UNW_AARCH64_V14,
+  UNW_ARM64_D15 = UNW_AARCH64_V15,
+  UNW_ARM64_D16 = UNW_AARCH64_V16,
+  UNW_ARM64_D17 = UNW_AARCH64_V17,
+  UNW_ARM64_D18 = UNW_AARCH64_V18,
+  UNW_ARM64_D19 = UNW_AARCH64_V19,
+  UNW_ARM64_D20 = UNW_AARCH64_V20,
+  UNW_ARM64_D21 = UNW_AARCH64_V21,
+  UNW_ARM64_D22 = UNW_AARCH64_V22,
+  UNW_ARM64_D23 = UNW_AARCH64_V23,
+  UNW_ARM64_D24 = UNW_AARCH64_V24,
+  UNW_ARM64_D25 = UNW_AARCH64_V25,
+  UNW_ARM64_D26 = UNW_AARCH64_V26,
+  UNW_ARM64_D27 = UNW_AARCH64_V27,
+  UNW_ARM64_D28 = UNW_AARCH64_V28,
+  UNW_ARM64_D29 = UNW_AARCH64_V29,
+  UNW_ARM64_D30 = UNW_AARCH64_V30,
+  UNW_ARM64_D31 = UNW_AARCH64_V31,
 };
 
 // 32-bit ARM registers. Numbers match DWARF for ARM spec #3.1 Table 1.
diff --git a/libunwind/include/mach-o/compact_unwind_encoding.h b/libunwind/include/mach-o/compact_unwind_encoding.h
index 5301b1055ef9..68d562eec438 100644
--- a/libunwind/include/mach-o/compact_unwind_encoding.h
+++ b/libunwind/include/mach-o/compact_unwind_encoding.h
@@ -1,4 +1,4 @@
-//===------------------ mach-o/compact_unwind_encoding.h ------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
diff --git a/libunwind/include/unwind.h b/libunwind/include/unwind.h
index 1d3444cd83b4..b8d6020a3367 100644
--- a/libunwind/include/unwind.h
+++ b/libunwind/include/unwind.h
@@ -1,4 +1,4 @@
-//===------------------------------- unwind.h -----------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -56,211 +56,23 @@ typedef enum {
 typedef struct _Unwind_Context _Unwind_Context;   // opaque
 
 #if defined(_LIBUNWIND_ARM_EHABI)
-typedef uint32_t _Unwind_State;
-
-static const _Unwind_State _US_VIRTUAL_UNWIND_FRAME   = 0;
-static const _Unwind_State _US_UNWIND_FRAME_STARTING  = 1;
-static const _Unwind_State _US_UNWIND_FRAME_RESUME    = 2;
-static const _Unwind_State _US_ACTION_MASK            = 3;
-/* Undocumented flag for force unwinding. */
-static const _Unwind_State _US_FORCE_UNWIND           = 8;
-
-typedef uint32_t _Unwind_EHT_Header;
-
-struct _Unwind_Control_Block;
-typedef struct _Unwind_Control_Block _Unwind_Control_Block;
-typedef struct _Unwind_Control_Block _Unwind_Exception; /* Alias */
-
-struct _Unwind_Control_Block {
-  uint64_t exception_class;
-  void (*exception_cleanup)(_Unwind_Reason_Code, _Unwind_Control_Block*);
-
-  /* Unwinder cache, private fields for the unwinder's use */
-  struct {
-    uint32_t reserved1; /* init reserved1 to 0, then don't touch */
-    uint32_t reserved2;
-    uint32_t reserved3;
-    uint32_t reserved4;
-    uint32_t reserved5;
-  } unwinder_cache;
-
-  /* Propagation barrier cache (valid after phase 1): */
-  struct {
-    uint32_t sp;
-    uint32_t bitpattern[5];
-  } barrier_cache;
-
-  /* Cleanup cache (preserved over cleanup): */
-  struct {
-    uint32_t bitpattern[4];
-  } cleanup_cache;
-
-  /* Pr cache (for pr's benefit): */
-  struct {
-    uint32_t fnstart; /* function start address */
-    _Unwind_EHT_Header* ehtp; /* pointer to EHT entry header word */
-    uint32_t additional;
-    uint32_t reserved1;
-  } pr_cache;
-
-  long long int :0; /* Enforce the 8-byte alignment */
-} __attribute__((__aligned__(8)));
-
-typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)
-      (_Unwind_State state,
-       _Unwind_Exception* exceptionObject,
-       struct _Unwind_Context* context);
-
-typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)(
-    _Unwind_State state, _Unwind_Exception *exceptionObject,
-    struct _Unwind_Context *context);
+#include "unwind_arm_ehabi.h"
 #else
-struct _Unwind_Context;   // opaque
-struct _Unwind_Exception; // forward declaration
-typedef struct _Unwind_Exception _Unwind_Exception;
-
-struct _Unwind_Exception {
-  uint64_t exception_class;
-  void (*exception_cleanup)(_Unwind_Reason_Code reason,
-                            _Unwind_Exception *exc);
-#if defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__)
-  uintptr_t private_[6];
-#else
-  uintptr_t private_1; // non-zero means forced unwind
-  uintptr_t private_2; // holds sp that phase1 found for phase2 to use
+#include "unwind_itanium.h"
 #endif
-#if __SIZEOF_POINTER__ == 4
-  // The implementation of _Unwind_Exception uses an attribute mode on the
-  // above fields which has the side effect of causing this whole struct to
-  // round up to 32 bytes in size (48 with SEH). To be more explicit, we add
-  // pad fields added for binary compatibility.
-  uint32_t reserved[3];
-#endif
-  // The Itanium ABI requires that _Unwind_Exception objects are "double-word
-  // aligned".  GCC has interpreted this to mean "use the maximum useful
-  // alignment for the target"; so do we.
-} __attribute__((__aligned__));
 
 typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)
     (int version,
      _Unwind_Action actions,
-     uint64_t exceptionClass,
+     _Unwind_Exception_Class exceptionClass,
      _Unwind_Exception* exceptionObject,
      struct _Unwind_Context* context,
-     void* stop_parameter );
-
-typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)(
-    int version, _Unwind_Action actions, uint64_t exceptionClass,
-    _Unwind_Exception *exceptionObject, struct _Unwind_Context *context);
-#endif
+     void* stop_parameter);
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-//
-// The following are the base functions documented by the C++ ABI
-//
-#ifdef __USING_SJLJ_EXCEPTIONS__
-extern _Unwind_Reason_Code
-    _Unwind_SjLj_RaiseException(_Unwind_Exception *exception_object);
-extern void _Unwind_SjLj_Resume(_Unwind_Exception *exception_object);
-#else
-extern _Unwind_Reason_Code
-    _Unwind_RaiseException(_Unwind_Exception *exception_object);
-extern void _Unwind_Resume(_Unwind_Exception *exception_object);
-#endif
-extern void _Unwind_DeleteException(_Unwind_Exception *exception_object);
-
-#if defined(_LIBUNWIND_ARM_EHABI)
-typedef enum {
-  _UVRSC_CORE = 0, /* integer register */
-  _UVRSC_VFP = 1, /* vfp */
-  _UVRSC_WMMXD = 3, /* Intel WMMX data register */
-  _UVRSC_WMMXC = 4 /* Intel WMMX control register */
-} _Unwind_VRS_RegClass;
-
-typedef enum {
-  _UVRSD_UINT32 = 0,
-  _UVRSD_VFPX = 1,
-  _UVRSD_UINT64 = 3,
-  _UVRSD_FLOAT = 4,
-  _UVRSD_DOUBLE = 5
-} _Unwind_VRS_DataRepresentation;
-
-typedef enum {
-  _UVRSR_OK = 0,
-  _UVRSR_NOT_IMPLEMENTED = 1,
-  _UVRSR_FAILED = 2
-} _Unwind_VRS_Result;
-
-extern void _Unwind_Complete(_Unwind_Exception* exception_object);
-
-extern _Unwind_VRS_Result
-_Unwind_VRS_Get(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
-                uint32_t regno, _Unwind_VRS_DataRepresentation representation,
-                void *valuep);
-
-extern _Unwind_VRS_Result
-_Unwind_VRS_Set(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
-                uint32_t regno, _Unwind_VRS_DataRepresentation representation,
-                void *valuep);
-
-extern _Unwind_VRS_Result
-_Unwind_VRS_Pop(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
-                uint32_t discriminator,
-                _Unwind_VRS_DataRepresentation representation);
-#endif
-
-#if !defined(_LIBUNWIND_ARM_EHABI)
-
-extern uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index);
-extern void _Unwind_SetGR(struct _Unwind_Context *context, int index,
-                          uintptr_t new_value);
-extern uintptr_t _Unwind_GetIP(struct _Unwind_Context *context);
-extern void _Unwind_SetIP(struct _Unwind_Context *, uintptr_t new_value);
-
-#else  // defined(_LIBUNWIND_ARM_EHABI)
-
-#if defined(_LIBUNWIND_UNWIND_LEVEL1_EXTERNAL_LINKAGE)
-#define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 extern
-#else
-#define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 static __inline__
-#endif
-
-// These are de facto helper functions for ARM, which delegate the function
-// calls to _Unwind_VRS_Get/Set().  These are not a part of ARM EHABI
-// specification, thus these function MUST be inlined.  Please don't replace
-// these with the "extern" function declaration; otherwise, the program
-// including this <unwind.h> header won't be ABI compatible and will result in
-// link error when we are linking the program with libgcc.
-
-_LIBUNWIND_EXPORT_UNWIND_LEVEL1
-uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index) {
-  uintptr_t value = 0;
-  _Unwind_VRS_Get(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);
-  return value;
-}
-
-_LIBUNWIND_EXPORT_UNWIND_LEVEL1
-void _Unwind_SetGR(struct _Unwind_Context *context, int index,
-                   uintptr_t value) {
-  _Unwind_VRS_Set(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);
-}
-
-_LIBUNWIND_EXPORT_UNWIND_LEVEL1
-uintptr_t _Unwind_GetIP(struct _Unwind_Context *context) {
-  // remove the thumb-bit before returning
-  return _Unwind_GetGR(context, 15) & (~(uintptr_t)0x1);
-}
-
-_LIBUNWIND_EXPORT_UNWIND_LEVEL1
-void _Unwind_SetIP(struct _Unwind_Context *context, uintptr_t value) {
-  uintptr_t thumb_bit = _Unwind_GetGR(context, 15) & ((uintptr_t)0x1);
-  _Unwind_SetGR(context, 15, value | thumb_bit);
-}
-#endif  // defined(_LIBUNWIND_ARM_EHABI)
-
 extern uintptr_t _Unwind_GetRegionStart(struct _Unwind_Context *context);
 extern uintptr_t
     _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context);
diff --git a/libunwind/include/unwind_arm_ehabi.h b/libunwind/include/unwind_arm_ehabi.h
new file mode 100644
index 000000000000..dc9d403e264c
--- /dev/null
+++ b/libunwind/include/unwind_arm_ehabi.h
@@ -0,0 +1,169 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//
+// C++ ABI Level 1 ABI documented at:
+//   https://github.com/ARM-software/abi-aa/blob/main/ehabi32/ehabi32.rst
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __ARM_EHABI_UNWIND_H__
+#define __ARM_EHABI_UNWIND_H__
+
+typedef uint32_t _Unwind_State;
+
+static const _Unwind_State _US_VIRTUAL_UNWIND_FRAME   = 0;
+static const _Unwind_State _US_UNWIND_FRAME_STARTING  = 1;
+static const _Unwind_State _US_UNWIND_FRAME_RESUME    = 2;
+static const _Unwind_State _US_ACTION_MASK            = 3;
+/* Undocumented flag for force unwinding. */
+static const _Unwind_State _US_FORCE_UNWIND           = 8;
+
+typedef uint32_t _Unwind_EHT_Header;
+
+struct _Unwind_Control_Block;
+typedef struct _Unwind_Control_Block _Unwind_Control_Block;
+#define _Unwind_Exception _Unwind_Control_Block /* Alias */
+typedef uint8_t _Unwind_Exception_Class[8];
+
+struct _Unwind_Control_Block {
+  _Unwind_Exception_Class exception_class;
+  void (*exception_cleanup)(_Unwind_Reason_Code, _Unwind_Control_Block*);
+
+  /* Unwinder cache, private fields for the unwinder's use */
+  struct {
+    uint32_t reserved1; /* init reserved1 to 0, then don't touch */
+    uint32_t reserved2;
+    uint32_t reserved3;
+    uint32_t reserved4;
+    uint32_t reserved5;
+  } unwinder_cache;
+
+  /* Propagation barrier cache (valid after phase 1): */
+  struct {
+    uint32_t sp;
+    uint32_t bitpattern[5];
+  } barrier_cache;
+
+  /* Cleanup cache (preserved over cleanup): */
+  struct {
+    uint32_t bitpattern[4];
+  } cleanup_cache;
+
+  /* Pr cache (for pr's benefit): */
+  struct {
+    uint32_t fnstart; /* function start address */
+    _Unwind_EHT_Header* ehtp; /* pointer to EHT entry header word */
+    uint32_t additional;
+    uint32_t reserved1;
+  } pr_cache;
+
+  long long int :0; /* Enforce the 8-byte alignment */
+} __attribute__((__aligned__(8)));
+
+typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)(
+    _Unwind_State state, _Unwind_Exception *exceptionObject,
+    struct _Unwind_Context *context);
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+//
+// The following are the base functions documented by the C++ ABI
+//
+#ifdef __USING_SJLJ_EXCEPTIONS__
+extern _Unwind_Reason_Code
+    _Unwind_SjLj_RaiseException(_Unwind_Exception *exception_object);
+extern void _Unwind_SjLj_Resume(_Unwind_Exception *exception_object);
+#else
+extern _Unwind_Reason_Code
+    _Unwind_RaiseException(_Unwind_Exception *exception_object);
+extern void _Unwind_Resume(_Unwind_Exception *exception_object);
+#endif
+extern void _Unwind_DeleteException(_Unwind_Exception *exception_object);
+
+typedef enum {
+  _UVRSC_CORE = 0, /* integer register */
+  _UVRSC_VFP = 1, /* vfp */
+  _UVRSC_WMMXD = 3, /* Intel WMMX data register */
+  _UVRSC_WMMXC = 4 /* Intel WMMX control register */
+} _Unwind_VRS_RegClass;
+
+typedef enum {
+  _UVRSD_UINT32 = 0,
+  _UVRSD_VFPX = 1,
+  _UVRSD_UINT64 = 3,
+  _UVRSD_FLOAT = 4,
+  _UVRSD_DOUBLE = 5
+} _Unwind_VRS_DataRepresentation;
+
+typedef enum {
+  _UVRSR_OK = 0,
+  _UVRSR_NOT_IMPLEMENTED = 1,
+  _UVRSR_FAILED = 2
+} _Unwind_VRS_Result;
+
+extern void _Unwind_Complete(_Unwind_Exception* exception_object);
+
+extern _Unwind_VRS_Result
+_Unwind_VRS_Get(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
+                uint32_t regno, _Unwind_VRS_DataRepresentation representation,
+                void *valuep);
+
+extern _Unwind_VRS_Result
+_Unwind_VRS_Set(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
+                uint32_t regno, _Unwind_VRS_DataRepresentation representation,
+                void *valuep);
+
+extern _Unwind_VRS_Result
+_Unwind_VRS_Pop(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
+                uint32_t discriminator,
+                _Unwind_VRS_DataRepresentation representation);
+
+#if defined(_LIBUNWIND_UNWIND_LEVEL1_EXTERNAL_LINKAGE)
+#define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 extern
+#else
+#define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 static __inline__
+#endif
+
+// These are de facto helper functions for ARM, which delegate the function
+// calls to _Unwind_VRS_Get/Set().  These are not a part of ARM EHABI
+// specification, thus these function MUST be inlined.  Please don't replace
+// these with the "extern" function declaration; otherwise, the program
+// including this <unwind.h> header won't be ABI compatible and will result in
+// link error when we are linking the program with libgcc.
+
+_LIBUNWIND_EXPORT_UNWIND_LEVEL1
+uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index) {
+  uintptr_t value = 0;
+  _Unwind_VRS_Get(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);
+  return value;
+}
+
+_LIBUNWIND_EXPORT_UNWIND_LEVEL1
+void _Unwind_SetGR(struct _Unwind_Context *context, int index,
+                   uintptr_t value) {
+  _Unwind_VRS_Set(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);
+}
+
+_LIBUNWIND_EXPORT_UNWIND_LEVEL1
+uintptr_t _Unwind_GetIP(struct _Unwind_Context *context) {
+  // remove the thumb-bit before returning
+  return _Unwind_GetGR(context, 15) & (~(uintptr_t)0x1);
+}
+
+_LIBUNWIND_EXPORT_UNWIND_LEVEL1
+void _Unwind_SetIP(struct _Unwind_Context *context, uintptr_t value) {
+  uintptr_t thumb_bit = _Unwind_GetGR(context, 15) & ((uintptr_t)0x1);
+  _Unwind_SetGR(context, 15, value | thumb_bit);
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // __ARM_EHABI_UNWIND_H__
diff --git a/libunwind/include/unwind_itanium.h b/libunwind/include/unwind_itanium.h
new file mode 100644
index 000000000000..d94a6183be29
--- /dev/null
+++ b/libunwind/include/unwind_itanium.h
@@ -0,0 +1,76 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//
+// C++ ABI Level 1 ABI documented at:
+//   https://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __ITANIUM_UNWIND_H__
+#define __ITANIUM_UNWIND_H__
+
+struct _Unwind_Context;   // opaque
+struct _Unwind_Exception; // forward declaration
+typedef struct _Unwind_Exception _Unwind_Exception;
+typedef uint64_t _Unwind_Exception_Class;
+
+struct _Unwind_Exception {
+  _Unwind_Exception_Class exception_class;
+  void (*exception_cleanup)(_Unwind_Reason_Code reason,
+                            _Unwind_Exception *exc);
+#if defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__)
+  uintptr_t private_[6];
+#else
+  uintptr_t private_1; // non-zero means forced unwind
+  uintptr_t private_2; // holds sp that phase1 found for phase2 to use
+#endif
+#if __SIZEOF_POINTER__ == 4
+  // The implementation of _Unwind_Exception uses an attribute mode on the
+  // above fields which has the side effect of causing this whole struct to
+  // round up to 32 bytes in size (48 with SEH). To be more explicit, we add
+  // pad fields added for binary compatibility.
+  uint32_t reserved[3];
+#endif
+  // The Itanium ABI requires that _Unwind_Exception objects are "double-word
+  // aligned".  GCC has interpreted this to mean "use the maximum useful
+  // alignment for the target"; so do we.
+} __attribute__((__aligned__));
+
+typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)(
+    int version, _Unwind_Action actions, uint64_t exceptionClass,
+    _Unwind_Exception *exceptionObject, struct _Unwind_Context *context);
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+//
+// The following are the base functions documented by the C++ ABI
+//
+#ifdef __USING_SJLJ_EXCEPTIONS__
+extern _Unwind_Reason_Code
+    _Unwind_SjLj_RaiseException(_Unwind_Exception *exception_object);
+extern void _Unwind_SjLj_Resume(_Unwind_Exception *exception_object);
+#else
+extern _Unwind_Reason_Code
+    _Unwind_RaiseException(_Unwind_Exception *exception_object);
+extern void _Unwind_Resume(_Unwind_Exception *exception_object);
+#endif
+extern void _Unwind_DeleteException(_Unwind_Exception *exception_object);
+
+
+extern uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index);
+extern void _Unwind_SetGR(struct _Unwind_Context *context, int index,
+                          uintptr_t new_value);
+extern uintptr_t _Unwind_GetIP(struct _Unwind_Context *context);
+extern void _Unwind_SetIP(struct _Unwind_Context *, uintptr_t new_value);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // __ITANIUM_UNWIND_H__
diff --git a/libunwind/src/AddressSpace.hpp b/libunwind/src/AddressSpace.hpp
index 171318ff6370..cfceac29537f 100644
--- a/libunwind/src/AddressSpace.hpp
+++ b/libunwind/src/AddressSpace.hpp
@@ -1,4 +1,4 @@
-//===------------------------- AddressSpace.hpp ---------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
diff --git a/libunwind/src/CompactUnwinder.hpp b/libunwind/src/CompactUnwinder.hpp
index 1c3175dff50a..0b2b5e111bfc 100644
--- a/libunwind/src/CompactUnwinder.hpp
+++ b/libunwind/src/CompactUnwinder.hpp
@@ -1,4 +1,4 @@
-//===-------------------------- CompactUnwinder.hpp -----------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -537,65 +537,65 @@ int CompactUnwinder_arm64<A>::stepWithCompactEncodingFrameless(
   uint64_t savedRegisterLoc = registers.getSP() + stackSize;
 
   if (encoding & UNWIND_ARM64_FRAME_X19_X20_PAIR) {
-    registers.setRegister(UNW_ARM64_X19, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X19, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
-    registers.setRegister(UNW_ARM64_X20, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X20, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
   }
   if (encoding & UNWIND_ARM64_FRAME_X21_X22_PAIR) {
-    registers.setRegister(UNW_ARM64_X21, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X21, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
-    registers.setRegister(UNW_ARM64_X22, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X22, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
   }
   if (encoding & UNWIND_ARM64_FRAME_X23_X24_PAIR) {
-    registers.setRegister(UNW_ARM64_X23, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X23, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
-    registers.setRegister(UNW_ARM64_X24, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X24, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
   }
   if (encoding & UNWIND_ARM64_FRAME_X25_X26_PAIR) {
-    registers.setRegister(UNW_ARM64_X25, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X25, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
-    registers.setRegister(UNW_ARM64_X26, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X26, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
   }
   if (encoding & UNWIND_ARM64_FRAME_X27_X28_PAIR) {
-    registers.setRegister(UNW_ARM64_X27, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X27, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
-    registers.setRegister(UNW_ARM64_X28, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X28, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
   }
 
   if (encoding & UNWIND_ARM64_FRAME_D8_D9_PAIR) {
-    registers.setFloatRegister(UNW_ARM64_D8,
+    registers.setFloatRegister(UNW_AARCH64_V8,
                                addressSpace.getDouble(savedRegisterLoc));
     savedRegisterLoc -= 8;
-    registers.setFloatRegister(UNW_ARM64_D9,
+    registers.setFloatRegister(UNW_AARCH64_V9,
                                addressSpace.getDouble(savedRegisterLoc));
     savedRegisterLoc -= 8;
   }
   if (encoding & UNWIND_ARM64_FRAME_D10_D11_PAIR) {
-    registers.setFloatRegister(UNW_ARM64_D10,
+    registers.setFloatRegister(UNW_AARCH64_V10,
                                addressSpace.getDouble(savedRegisterLoc));
     savedRegisterLoc -= 8;
-    registers.setFloatRegister(UNW_ARM64_D11,
+    registers.setFloatRegister(UNW_AARCH64_V11,
                                addressSpace.getDouble(savedRegisterLoc));
     savedRegisterLoc -= 8;
   }
   if (encoding & UNWIND_ARM64_FRAME_D12_D13_PAIR) {
-    registers.setFloatRegister(UNW_ARM64_D12,
+    registers.setFloatRegister(UNW_AARCH64_V12,
                                addressSpace.getDouble(savedRegisterLoc));
     savedRegisterLoc -= 8;
-    registers.setFloatRegister(UNW_ARM64_D13,
+    registers.setFloatRegister(UNW_AARCH64_V13,
                                addressSpace.getDouble(savedRegisterLoc));
     savedRegisterLoc -= 8;
   }
   if (encoding & UNWIND_ARM64_FRAME_D14_D15_PAIR) {
-    registers.setFloatRegister(UNW_ARM64_D14,
+    registers.setFloatRegister(UNW_AARCH64_V14,
                                addressSpace.getDouble(savedRegisterLoc));
     savedRegisterLoc -= 8;
-    registers.setFloatRegister(UNW_ARM64_D15,
+    registers.setFloatRegister(UNW_AARCH64_V15,
                                addressSpace.getDouble(savedRegisterLoc));
     savedRegisterLoc -= 8;
   }
@@ -604,7 +604,7 @@ int CompactUnwinder_arm64<A>::stepWithCompactEncodingFrameless(
   registers.setSP(savedRegisterLoc);
 
   // set pc to be value in lr
-  registers.setIP(registers.getRegister(UNW_ARM64_LR));
+  registers.setIP(registers.getRegister(UNW_AARCH64_LR));
 
   return UNW_STEP_SUCCESS;
 }
@@ -616,65 +616,65 @@ int CompactUnwinder_arm64<A>::stepWithCompactEncodingFrame(
   uint64_t savedRegisterLoc = registers.getFP() - 8;
 
   if (encoding & UNWIND_ARM64_FRAME_X19_X20_PAIR) {
-    registers.setRegister(UNW_ARM64_X19, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X19, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
-    registers.setRegister(UNW_ARM64_X20, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X20, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
   }
   if (encoding & UNWIND_ARM64_FRAME_X21_X22_PAIR) {
-    registers.setRegister(UNW_ARM64_X21, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X21, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
-    registers.setRegister(UNW_ARM64_X22, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X22, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
   }
   if (encoding & UNWIND_ARM64_FRAME_X23_X24_PAIR) {
-    registers.setRegister(UNW_ARM64_X23, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X23, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
-    registers.setRegister(UNW_ARM64_X24, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X24, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
   }
   if (encoding & UNWIND_ARM64_FRAME_X25_X26_PAIR) {
-    registers.setRegister(UNW_ARM64_X25, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X25, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
-    registers.setRegister(UNW_ARM64_X26, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X26, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
   }
   if (encoding & UNWIND_ARM64_FRAME_X27_X28_PAIR) {
-    registers.setRegister(UNW_ARM64_X27, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X27, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
-    registers.setRegister(UNW_ARM64_X28, addressSpace.get64(savedRegisterLoc));
+    registers.setRegister(UNW_AARCH64_X28, addressSpace.get64(savedRegisterLoc));
     savedRegisterLoc -= 8;
   }
 
   if (encoding & UNWIND_ARM64_FRAME_D8_D9_PAIR) {
-    registers.setFloatRegister(UNW_ARM64_D8,
+    registers.setFloatRegister(UNW_AARCH64_V8,
                                addressSpace.getDouble(savedRegisterLoc));
     savedRegisterLoc -= 8;
-    registers.setFloatRegister(UNW_ARM64_D9,
+    registers.setFloatRegister(UNW_AARCH64_V9,
                                addressSpace.getDouble(savedRegisterLoc));
     savedRegisterLoc -= 8;
   }
   if (encoding & UNWIND_ARM64_FRAME_D10_D11_PAIR) {
-    registers.setFloatRegister(UNW_ARM64_D10,
+    registers.setFloatRegister(UNW_AARCH64_V10,
                                addressSpace.getDouble(savedRegisterLoc));
     savedRegisterLoc -= 8;
-    registers.setFloatRegister(UNW_ARM64_D11,
+    registers.setFloatRegister(UNW_AARCH64_V11,
                                addressSpace.getDouble(savedRegisterLoc));
     savedRegisterLoc -= 8;
   }
   if (encoding & UNWIND_ARM64_FRAME_D12_D13_PAIR) {
-    registers.setFloatRegister(UNW_ARM64_D12,
+    registers.setFloatRegister(UNW_AARCH64_V12,
                                addressSpace.getDouble(savedRegisterLoc));
     savedRegisterLoc -= 8;
-    registers.setFloatRegister(UNW_ARM64_D13,
+    registers.setFloatRegister(UNW_AARCH64_V13,
                                addressSpace.getDouble(savedRegisterLoc));
     savedRegisterLoc -= 8;
   }
   if (encoding & UNWIND_ARM64_FRAME_D14_D15_PAIR) {
-    registers.setFloatRegister(UNW_ARM64_D14,
+    registers.setFloatRegister(UNW_AARCH64_V14,
                                addressSpace.getDouble(savedRegisterLoc));
     savedRegisterLoc -= 8;
-    registers.setFloatRegister(UNW_ARM64_D15,
+    registers.setFloatRegister(UNW_AARCH64_V15,
                                addressSpace.getDouble(savedRegisterLoc));
     savedRegisterLoc -= 8;
   }
diff --git a/libunwind/src/DwarfInstructions.hpp b/libunwind/src/DwarfInstructions.hpp
index 686c6be0d8fd..19835aad668f 100644
--- a/libunwind/src/DwarfInstructions.hpp
+++ b/libunwind/src/DwarfInstructions.hpp
@@ -1,4 +1,4 @@
-//===-------------------------- DwarfInstructions.hpp ---------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -115,12 +115,15 @@ double DwarfInstructions<A, R>::getSavedFloatRegister(
     return addressSpace.getDouble(
         evaluateExpression((pint_t)savedReg.value, addressSpace,
                             registers, cfa));
-
+  case CFI_Parser<A>::kRegisterUndefined:
+    return 0.0;
+  case CFI_Parser<A>::kRegisterInRegister:
+#ifndef _LIBUNWIND_TARGET_ARM
+    return registers.getFloatRegister((int)savedReg.value);
+#endif
   case CFI_Parser<A>::kRegisterIsExpression:
   case CFI_Parser<A>::kRegisterUnused:
-  case CFI_Parser<A>::kRegisterUndefined:
   case CFI_Parser<A>::kRegisterOffsetFromCFA:
-  case CFI_Parser<A>::kRegisterInRegister:
     // FIX ME
     break;
   }
@@ -219,7 +222,7 @@ int DwarfInstructions<A, R>::stepWithDwarf(A &addressSpace, pint_t pc,
       // restored. autia1716 is used instead of autia as autia1716 assembles
       // to a NOP on pre-v8.3a architectures.
       if ((R::getArch() == REGISTERS_ARM64) &&
-          prolog.savedRegisters[UNW_ARM64_RA_SIGN_STATE].value &&
+          prolog.savedRegisters[UNW_AARCH64_RA_SIGN_STATE].value &&
           returnAddress != 0) {
 #if !defined(_LIBUNWIND_IS_NATIVE_ONLY)
         return UNW_ECROSSRASIGNING;
diff --git a/libunwind/src/DwarfParser.hpp b/libunwind/src/DwarfParser.hpp
index de0eb6de9d70..2153a71c2ec0 100644
--- a/libunwind/src/DwarfParser.hpp
+++ b/libunwind/src/DwarfParser.hpp
@@ -1,4 +1,4 @@
-//===--------------------------- DwarfParser.hpp --------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -154,7 +154,8 @@ public:
                       uintptr_t sectionLength, pint_t fdeHint, FDE_Info *fdeInfo,
                       CIE_Info *cieInfo);
   static const char *decodeFDE(A &addressSpace, pint_t fdeStart,
-                               FDE_Info *fdeInfo, CIE_Info *cieInfo);
+                               FDE_Info *fdeInfo, CIE_Info *cieInfo,
+                               bool useCIEInfo = false);
   static bool parseFDEInstructions(A &addressSpace, const FDE_Info &fdeInfo,
                                    const CIE_Info &cieInfo, pint_t upToPC,
                                    int arch, PrologInfo *results);
@@ -162,10 +163,14 @@ public:
   static const char *parseCIE(A &addressSpace, pint_t cie, CIE_Info *cieInfo);
 };
 
-/// Parse a FDE into a CIE_Info and an FDE_Info
+/// Parse a FDE into a CIE_Info and an FDE_Info. If useCIEInfo is
+/// true, treat cieInfo as already-parsed CIE_Info (whose start offset
+/// must match the one specified by the FDE) rather than parsing the
+/// one indicated within the FDE.
 template <typename A>
 const char *CFI_Parser<A>::decodeFDE(A &addressSpace, pint_t fdeStart,
-                                     FDE_Info *fdeInfo, CIE_Info *cieInfo) {
+                                     FDE_Info *fdeInfo, CIE_Info *cieInfo,
+                                     bool useCIEInfo) {
   pint_t p = fdeStart;
   pint_t cfiLength = (pint_t)addressSpace.get32(p);
   p += 4;
@@ -181,9 +186,14 @@ const char *CFI_Parser<A>::decodeFDE(A &addressSpace, pint_t fdeStart,
     return "FDE is really a CIE"; // this is a CIE not an FDE
   pint_t nextCFI = p + cfiLength;
   pint_t cieStart = p - ciePointer;
-  const char *err = parseCIE(addressSpace, cieStart, cieInfo);
-  if (err != NULL)
-    return err;
+  if (useCIEInfo) {
+    if (cieInfo->cieStart != cieStart)
+      return "CIE start does not match";
+  } else {
+    const char *err = parseCIE(addressSpace, cieStart, cieInfo);
+    if (err != NULL)
+      return err;
+  }
   p += 4;
   // Parse pc begin and range.
   pint_t pcStart =
@@ -733,8 +743,8 @@ bool CFI_Parser<A>::parseFDEInstructions(A &addressSpace,
 #if defined(_LIBUNWIND_TARGET_AARCH64)
         case REGISTERS_ARM64: {
           int64_t value =
-              results->savedRegisters[UNW_ARM64_RA_SIGN_STATE].value ^ 0x1;
-          results->setRegisterValue(UNW_ARM64_RA_SIGN_STATE, value,
+              results->savedRegisters[UNW_AARCH64_RA_SIGN_STATE].value ^ 0x1;
+          results->setRegisterValue(UNW_AARCH64_RA_SIGN_STATE, value,
                                     initialState);
           _LIBUNWIND_TRACE_DWARF("DW_CFA_AARCH64_negate_ra_state\n");
         } break;
diff --git a/libunwind/src/EHHeaderParser.hpp b/libunwind/src/EHHeaderParser.hpp
index f97cca54825f..9a38070faba9 100644
--- a/libunwind/src/EHHeaderParser.hpp
+++ b/libunwind/src/EHHeaderParser.hpp
@@ -1,4 +1,4 @@
-//===------------------------- EHHeaderParser.hpp -------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
diff --git a/libunwind/src/RWMutex.hpp b/libunwind/src/RWMutex.hpp
index fcd3f4967d17..344d35641f07 100644
--- a/libunwind/src/RWMutex.hpp
+++ b/libunwind/src/RWMutex.hpp
@@ -1,4 +1,4 @@
-//===----------------------------- Registers.hpp --------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
diff --git a/libunwind/src/Registers.hpp b/libunwind/src/Registers.hpp
index aea84cc22721..c2d5327eade3 100644
--- a/libunwind/src/Registers.hpp
+++ b/libunwind/src/Registers.hpp
@@ -1,4 +1,4 @@
-//===----------------------------- Registers.hpp --------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -15,8 +15,9 @@
 #include <stdint.h>
 #include <string.h>
 
-#include "libunwind.h"
+#include "cet_unwind.h"
 #include "config.h"
+#include "libunwind.h"
 
 namespace libunwind {
 
@@ -42,6 +43,13 @@ enum {
 #if defined(_LIBUNWIND_TARGET_I386)
 class _LIBUNWIND_HIDDEN Registers_x86;
 extern "C" void __libunwind_Registers_x86_jumpto(Registers_x86 *);
+
+#if defined(_LIBUNWIND_USE_CET)
+extern "C" void *__libunwind_cet_get_jump_target() {
+  return reinterpret_cast<void *>(&__libunwind_Registers_x86_jumpto);
+}
+#endif
+
 /// Registers_x86 holds the register state of a thread in a 32-bit intel
 /// process.
 class _LIBUNWIND_HIDDEN Registers_x86 {
@@ -253,6 +261,13 @@ inline void Registers_x86::setVectorRegister(int, v128) {
 /// process.
 class _LIBUNWIND_HIDDEN Registers_x86_64;
 extern "C" void __libunwind_Registers_x86_64_jumpto(Registers_x86_64 *);
+
+#if defined(_LIBUNWIND_USE_CET)
+extern "C" void *__libunwind_cet_get_jump_target() {
+  return reinterpret_cast<void *>(&__libunwind_Registers_x86_64_jumpto);
+}
+#endif
+
 class _LIBUNWIND_HIDDEN Registers_x86_64 {
 public:
   Registers_x86_64();
@@ -339,7 +354,7 @@ inline bool Registers_x86_64::validRegister(int regNum) const {
     return true;
   if (regNum < 0)
     return false;
-  if (regNum > 15)
+  if (regNum > 16)
     return false;
   return true;
 }
@@ -347,6 +362,7 @@ inline bool Registers_x86_64::validRegister(int regNum) const {
 inline uint64_t Registers_x86_64::getRegister(int regNum) const {
   switch (regNum) {
   case UNW_REG_IP:
+  case UNW_X86_64_RIP:
     return _registers.__rip;
   case UNW_REG_SP:
     return _registers.__rsp;
@@ -389,6 +405,7 @@ inline uint64_t Registers_x86_64::getRegister(int regNum) const {
 inline void Registers_x86_64::setRegister(int regNum, uint64_t value) {
   switch (regNum) {
   case UNW_REG_IP:
+  case UNW_X86_64_RIP:
     _registers.__rip = value;
     return;
   case UNW_REG_SP:
@@ -449,6 +466,7 @@ inline void Registers_x86_64::setRegister(int regNum, uint64_t value) {
 inline const char *Registers_x86_64::getRegisterName(int regNum) {
   switch (regNum) {
   case UNW_REG_IP:
+  case UNW_X86_64_RIP:
     return "rip";
   case UNW_REG_SP:
     return "rsp";
@@ -1847,7 +1865,7 @@ inline bool Registers_arm64::validRegister(int regNum) const {
     return false;
   if (regNum > 95)
     return false;
-  if (regNum == UNW_ARM64_RA_SIGN_STATE)
+  if (regNum == UNW_AARCH64_RA_SIGN_STATE)
     return true;
   if ((regNum > 32) && (regNum < 64))
     return false;
@@ -1855,15 +1873,15 @@ inline bool Registers_arm64::validRegister(int regNum) const {
 }
 
 inline uint64_t Registers_arm64::getRegister(int regNum) const {
-  if (regNum == UNW_REG_IP || regNum == UNW_ARM64_PC)
+  if (regNum == UNW_REG_IP || regNum == UNW_AARCH64_PC)
     return _registers.__pc;
-  if (regNum == UNW_REG_SP || regNum == UNW_ARM64_SP)
+  if (regNum == UNW_REG_SP || regNum == UNW_AARCH64_SP)
     return _registers.__sp;
-  if (regNum == UNW_ARM64_RA_SIGN_STATE)
+  if (regNum == UNW_AARCH64_RA_SIGN_STATE)
     return _registers.__ra_sign_state;
-  if (regNum == UNW_ARM64_FP)
+  if (regNum == UNW_AARCH64_FP)
     return _registers.__fp;
-  if (regNum == UNW_ARM64_LR)
+  if (regNum == UNW_AARCH64_LR)
     return _registers.__lr;
   if ((regNum >= 0) && (regNum < 29))
     return _registers.__x[regNum];
@@ -1871,15 +1889,15 @@ inline uint64_t Registers_arm64::getRegister(int regNum) const {
 }
 
 inline void Registers_arm64::setRegister(int regNum, uint64_t value) {
-  if (regNum == UNW_REG_IP || regNum == UNW_ARM64_PC)
+  if (regNum == UNW_REG_IP || regNum == UNW_AARCH64_PC)
     _registers.__pc = value;
-  else if (regNum == UNW_REG_SP || regNum == UNW_ARM64_SP)
+  else if (regNum == UNW_REG_SP || regNum == UNW_AARCH64_SP)
     _registers.__sp = value;
-  else if (regNum == UNW_ARM64_RA_SIGN_STATE)
+  else if (regNum == UNW_AARCH64_RA_SIGN_STATE)
     _registers.__ra_sign_state = value;
-  else if (regNum == UNW_ARM64_FP)
+  else if (regNum == UNW_AARCH64_FP)
     _registers.__fp = value;
-  else if (regNum == UNW_ARM64_LR)
+  else if (regNum == UNW_AARCH64_LR)
     _registers.__lr = value;
   else if ((regNum >= 0) && (regNum < 29))
     _registers.__x[regNum] = value;
@@ -1893,135 +1911,135 @@ inline const char *Registers_arm64::getRegisterName(int regNum) {
     return "pc";
   case UNW_REG_SP:
     return "sp";
-  case UNW_ARM64_X0:
+  case UNW_AARCH64_X0:
     return "x0";
-  case UNW_ARM64_X1:
+  case UNW_AARCH64_X1:
     return "x1";
-  case UNW_ARM64_X2:
+  case UNW_AARCH64_X2:
     return "x2";
-  case UNW_ARM64_X3:
+  case UNW_AARCH64_X3:
     return "x3";
-  case UNW_ARM64_X4:
+  case UNW_AARCH64_X4:
     return "x4";
-  case UNW_ARM64_X5:
+  case UNW_AARCH64_X5:
     return "x5";
-  case UNW_ARM64_X6:
+  case UNW_AARCH64_X6:
     return "x6";
-  case UNW_ARM64_X7:
+  case UNW_AARCH64_X7:
     return "x7";
-  case UNW_ARM64_X8:
+  case UNW_AARCH64_X8:
     return "x8";
-  case UNW_ARM64_X9:
+  case UNW_AARCH64_X9:
     return "x9";
-  case UNW_ARM64_X10:
+  case UNW_AARCH64_X10:
     return "x10";
-  case UNW_ARM64_X11:
+  case UNW_AARCH64_X11:
     return "x11";
-  case UNW_ARM64_X12:
+  case UNW_AARCH64_X12:
     return "x12";
-  case UNW_ARM64_X13:
+  case UNW_AARCH64_X13:
     return "x13";
-  case UNW_ARM64_X14:
+  case UNW_AARCH64_X14:
     return "x14";
-  case UNW_ARM64_X15:
+  case UNW_AARCH64_X15:
     return "x15";
-  case UNW_ARM64_X16:
+  case UNW_AARCH64_X16:
     return "x16";
-  case UNW_ARM64_X17:
+  case UNW_AARCH64_X17:
     return "x17";
-  case UNW_ARM64_X18:
+  case UNW_AARCH64_X18:
     return "x18";
-  case UNW_ARM64_X19:
+  case UNW_AARCH64_X19:
     return "x19";
-  case UNW_ARM64_X20:
+  case UNW_AARCH64_X20:
     return "x20";
-  case UNW_ARM64_X21:
+  case UNW_AARCH64_X21:
     return "x21";
-  case UNW_ARM64_X22:
+  case UNW_AARCH64_X22:
     return "x22";
-  case UNW_ARM64_X23:
+  case UNW_AARCH64_X23:
     return "x23";
-  case UNW_ARM64_X24:
+  case UNW_AARCH64_X24:
     return "x24";
-  case UNW_ARM64_X25:
+  case UNW_AARCH64_X25:
     return "x25";
-  case UNW_ARM64_X26:
+  case UNW_AARCH64_X26:
     return "x26";
-  case UNW_ARM64_X27:
+  case UNW_AARCH64_X27:
     return "x27";
-  case UNW_ARM64_X28:
+  case UNW_AARCH64_X28:
     return "x28";
-  case UNW_ARM64_FP:
+  case UNW_AARCH64_FP:
     return "fp";
-  case UNW_ARM64_LR:
+  case UNW_AARCH64_LR:
     return "lr";
-  case UNW_ARM64_SP:
+  case UNW_AARCH64_SP:
     return "sp";
-  case UNW_ARM64_PC:
+  case UNW_AARCH64_PC:
     return "pc";
-  case UNW_ARM64_D0:
+  case UNW_AARCH64_V0:
     return "d0";
-  case UNW_ARM64_D1:
+  case UNW_AARCH64_V1:
     return "d1";
-  case UNW_ARM64_D2:
+  case UNW_AARCH64_V2:
     return "d2";
-  case UNW_ARM64_D3:
+  case UNW_AARCH64_V3:
     return "d3";
-  case UNW_ARM64_D4:
+  case UNW_AARCH64_V4:
     return "d4";
-  case UNW_ARM64_D5:
+  case UNW_AARCH64_V5:
     return "d5";
-  case UNW_ARM64_D6:
+  case UNW_AARCH64_V6:
     return "d6";
-  case UNW_ARM64_D7:
+  case UNW_AARCH64_V7:
     return "d7";
-  case UNW_ARM64_D8:
+  case UNW_AARCH64_V8:
     return "d8";
-  case UNW_ARM64_D9:
+  case UNW_AARCH64_V9:
     return "d9";
-  case UNW_ARM64_D10:
+  case UNW_AARCH64_V10:
     return "d10";
-  case UNW_ARM64_D11:
+  case UNW_AARCH64_V11:
     return "d11";
-  case UNW_ARM64_D12:
+  case UNW_AARCH64_V12:
     return "d12";
-  case UNW_ARM64_D13:
+  case UNW_AARCH64_V13:
     return "d13";
-  case UNW_ARM64_D14:
+  case UNW_AARCH64_V14:
     return "d14";
-  case UNW_ARM64_D15:
+  case UNW_AARCH64_V15:
     return "d15";
-  case UNW_ARM64_D16:
+  case UNW_AARCH64_V16:
     return "d16";
-  case UNW_ARM64_D17:
+  case UNW_AARCH64_V17:
     return "d17";
-  case UNW_ARM64_D18:
+  case UNW_AARCH64_V18:
     return "d18";
-  case UNW_ARM64_D19:
+  case UNW_AARCH64_V19:
     return "d19";
-  case UNW_ARM64_D20:
+  case UNW_AARCH64_V20:
     return "d20";
-  case UNW_ARM64_D21:
+  case UNW_AARCH64_V21:
     return "d21";
-  case UNW_ARM64_D22:
+  case UNW_AARCH64_V22:
     return "d22";
-  case UNW_ARM64_D23:
+  case UNW_AARCH64_V23:
     return "d23";
-  case UNW_ARM64_D24:
+  case UNW_AARCH64_V24:
     return "d24";
-  case UNW_ARM64_D25:
+  case UNW_AARCH64_V25:
     return "d25";
-  case UNW_ARM64_D26:
+  case UNW_AARCH64_V26:
     return "d26";
-  case UNW_ARM64_D27:
+  case UNW_AARCH64_V27:
     return "d27";
-  case UNW_ARM64_D28:
+  case UNW_AARCH64_V28:
     return "d28";
-  case UNW_ARM64_D29:
+  case UNW_AARCH64_V29:
     return "d29";
-  case UNW_ARM64_D30:
+  case UNW_AARCH64_V30:
     return "d30";
-  case UNW_ARM64_D31:
+  case UNW_AARCH64_V31:
     return "d31";
   default:
     return "unknown register";
@@ -2029,21 +2047,21 @@ inline const char *Registers_arm64::getRegisterName(int regNum) {
 }
 
 inline bool Registers_arm64::validFloatRegister(int regNum) const {
-  if (regNum < UNW_ARM64_D0)
+  if (regNum < UNW_AARCH64_V0)
     return false;
-  if (regNum > UNW_ARM64_D31)
+  if (regNum > UNW_AARCH64_V31)
     return false;
   return true;
 }
 
 inline double Registers_arm64::getFloatRegister(int regNum) const {
   assert(validFloatRegister(regNum));
-  return _vectorHalfRegisters[regNum - UNW_ARM64_D0];
+  return _vectorHalfRegisters[regNum - UNW_AARCH64_V0];
 }
 
 inline void Registers_arm64::setFloatRegister(int regNum, double value) {
   assert(validFloatRegister(regNum));
-  _vectorHalfRegisters[regNum - UNW_ARM64_D0] = value;
+  _vectorHalfRegisters[regNum - UNW_AARCH64_V0] = value;
 }
 
 inline bool Registers_arm64::validVectorRegister(int) const {
diff --git a/libunwind/src/Unwind-EHABI.cpp b/libunwind/src/Unwind-EHABI.cpp
index 32b5cbc3be92..d3577c9f7cf8 100644
--- a/libunwind/src/Unwind-EHABI.cpp
+++ b/libunwind/src/Unwind-EHABI.cpp
@@ -1,4 +1,4 @@
-//===--------------------------- Unwind-EHABI.cpp -------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -97,9 +97,11 @@ _Unwind_Reason_Code ProcessDescriptors(
       case Descriptor::LU32:
         descriptor = getNextWord(descriptor, &length);
         descriptor = getNextWord(descriptor, &offset);
+        break;
       case Descriptor::LU16:
         descriptor = getNextNibble(descriptor, &length);
         descriptor = getNextNibble(descriptor, &offset);
+        break;
       default:
         assert(false);
         return _URC_FAILURE;
@@ -461,6 +463,7 @@ unwind_phase1(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *except
       return _URC_FATAL_PHASE1_ERROR;
     }
 
+#ifndef NDEBUG
     // When tracing, print state information.
     if (_LIBUNWIND_TRACING_UNWINDING) {
       char functionBuf[512];
@@ -479,6 +482,7 @@ unwind_phase1(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *except
           frameInfo.start_ip, functionName,
           frameInfo.lsda, frameInfo.handler);
     }
+#endif
 
     // If there is a personality routine, ask it if it will want to stop at
     // this frame.
@@ -580,6 +584,7 @@ static _Unwind_Reason_Code unwind_phase2(unw_context_t *uc, unw_cursor_t *cursor
       return _URC_FATAL_PHASE2_ERROR;
     }
 
+#ifndef NDEBUG
     // When tracing, print state information.
     if (_LIBUNWIND_TRACING_UNWINDING) {
       char functionBuf[512];
@@ -596,11 +601,12 @@ static _Unwind_Reason_Code unwind_phase2(unw_context_t *uc, unw_cursor_t *cursor
           functionName, sp, frameInfo.lsda,
           frameInfo.handler);
     }
+#endif
 
     // If there is a personality routine, tell it we are unwinding.
     if (frameInfo.handler != 0) {
       _Unwind_Personality_Fn p =
-          (_Unwind_Personality_Fn)(long)(frameInfo.handler);
+          (_Unwind_Personality_Fn)(intptr_t)(frameInfo.handler);
       struct _Unwind_Context *context = (struct _Unwind_Context *)(cursor);
       // EHABI #7.2
       exception_object->pr_cache.fnstart = frameInfo.start_ip;
@@ -668,6 +674,114 @@ static _Unwind_Reason_Code unwind_phase2(unw_context_t *uc, unw_cursor_t *cursor
   return _URC_FATAL_PHASE2_ERROR;
 }
 
+static _Unwind_Reason_Code
+unwind_phase2_forced(unw_context_t *uc, unw_cursor_t *cursor,
+                     _Unwind_Exception *exception_object, _Unwind_Stop_Fn stop,
+                     void *stop_parameter) {
+  // See comment at the start of unwind_phase1 regarding VRS integrity.
+  __unw_init_local(cursor, uc);
+  _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_force(ex_ojb=%p)",
+                             static_cast<void *>(exception_object));
+  // Walk each frame until we reach where search phase said to stop
+  while (true) {
+    // Update info about this frame.
+    unw_proc_info_t frameInfo;
+    if (__unw_get_proc_info(cursor, &frameInfo) != UNW_ESUCCESS) {
+      _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): __unw_step "
+                                 "failed => _URC_END_OF_STACK",
+                                 (void *)exception_object);
+      return _URC_FATAL_PHASE2_ERROR;
+    }
+
+#ifndef NDEBUG
+    // When tracing, print state information.
+    if (_LIBUNWIND_TRACING_UNWINDING) {
+      char functionBuf[512];
+      const char *functionName = functionBuf;
+      unw_word_t offset;
+      if ((__unw_get_proc_name(cursor, functionBuf, sizeof(functionBuf),
+                               &offset) != UNW_ESUCCESS) ||
+          (frameInfo.start_ip + offset > frameInfo.end_ip))
+        functionName = ".anonymous.";
+      _LIBUNWIND_TRACE_UNWINDING(
+          "unwind_phase2_forced(ex_ojb=%p): start_ip=0x%" PRIxPTR
+          ", func=%s, lsda=0x%" PRIxPTR ", personality=0x%" PRIxPTR,
+          (void *)exception_object, frameInfo.start_ip, functionName,
+          frameInfo.lsda, frameInfo.handler);
+    }
+#endif
+
+    // Call stop function at each frame.
+    _Unwind_Action action =
+        (_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE);
+    _Unwind_Reason_Code stopResult =
+        (*stop)(1, action, exception_object->exception_class, exception_object,
+                (_Unwind_Context *)(cursor), stop_parameter);
+    _LIBUNWIND_TRACE_UNWINDING(
+        "unwind_phase2_forced(ex_ojb=%p): stop function returned %d",
+        (void *)exception_object, stopResult);
+    if (stopResult != _URC_NO_REASON) {
+      _LIBUNWIND_TRACE_UNWINDING(
+          "unwind_phase2_forced(ex_ojb=%p): stopped by stop function",
+          (void *)exception_object);
+      return _URC_FATAL_PHASE2_ERROR;
+    }
+
+    // If there is a personality routine, tell it we are unwinding.
+    if (frameInfo.handler != 0) {
+      _Unwind_Personality_Fn p =
+          (_Unwind_Personality_Fn)(uintptr_t)(frameInfo.handler);
+      struct _Unwind_Context *context = (struct _Unwind_Context *)(cursor);
+      // EHABI #7.2
+      exception_object->pr_cache.fnstart = frameInfo.start_ip;
+      exception_object->pr_cache.ehtp =
+          (_Unwind_EHT_Header *)frameInfo.unwind_info;
+      exception_object->pr_cache.additional = frameInfo.flags;
+      _Unwind_Reason_Code personalityResult =
+          (*p)(_US_FORCE_UNWIND | _US_UNWIND_FRAME_STARTING, exception_object,
+               context);
+      switch (personalityResult) {
+      case _URC_CONTINUE_UNWIND:
+        _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
+                                   "personality returned "
+                                   "_URC_CONTINUE_UNWIND",
+                                   (void *)exception_object);
+        // Destructors called, continue unwinding
+        break;
+      case _URC_INSTALL_CONTEXT:
+        _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
+                                   "personality returned "
+                                   "_URC_INSTALL_CONTEXT",
+                                   (void *)exception_object);
+        // We may get control back if landing pad calls _Unwind_Resume().
+        __unw_resume(cursor);
+        break;
+      default:
+        // Personality routine returned an unknown result code.
+        _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
+                                   "personality returned %d, "
+                                   "_URC_FATAL_PHASE2_ERROR",
+                                   (void *)exception_object, personalityResult);
+        return _URC_FATAL_PHASE2_ERROR;
+      }
+    }
+  }
+
+  // Call stop function one last time and tell it we've reached the end
+  // of the stack.
+  _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): calling stop "
+                             "function with _UA_END_OF_STACK",
+                             (void *)exception_object);
+  _Unwind_Action lastAction =
+      (_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE | _UA_END_OF_STACK);
+  (*stop)(1, lastAction, exception_object->exception_class, exception_object,
+          (struct _Unwind_Context *)(cursor), stop_parameter);
+
+  // Clean up phase did not resume at the frame that the search phase said it
+  // would.
+  return _URC_FATAL_PHASE2_ERROR;
+}
+
 /// Called by __cxa_throw.  Only returns if there is a fatal error.
 _LIBUNWIND_EXPORT _Unwind_Reason_Code
 _Unwind_RaiseException(_Unwind_Exception *exception_object) {
@@ -715,10 +829,13 @@ _Unwind_Resume(_Unwind_Exception *exception_object) {
   unw_cursor_t cursor;
   __unw_getcontext(&uc);
 
-  // _Unwind_RaiseException on EHABI will always set the reserved1 field to 0,
-  // which is in the same position as private_1 below.
-  // TODO(ajwong): Who wronte the above? Why is it true?
-  unwind_phase2(&uc, &cursor, exception_object, true);
+  if (exception_object->unwinder_cache.reserved1)
+    unwind_phase2_forced(
+        &uc, &cursor, exception_object,
+        (_Unwind_Stop_Fn)exception_object->unwinder_cache.reserved1,
+        (void *)exception_object->unwinder_cache.reserved3);
+  else
+    unwind_phase2(&uc, &cursor, exception_object, true);
 
   // Clients assume _Unwind_Resume() does not return, so all we can do is abort.
   _LIBUNWIND_ABORT("_Unwind_Resume() can't return");
@@ -965,6 +1082,27 @@ _Unwind_VRS_Pop(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
   _LIBUNWIND_ABORT("unsupported register class");
 }
 
+/// Not used by C++.
+/// Unwinds stack, calling "stop" function at each frame.
+/// Could be used to implement longjmp().
+_LIBUNWIND_EXPORT _Unwind_Reason_Code
+_Unwind_ForcedUnwind(_Unwind_Exception *exception_object, _Unwind_Stop_Fn stop,
+                     void *stop_parameter) {
+  _LIBUNWIND_TRACE_API("_Unwind_ForcedUnwind(ex_obj=%p, stop=%p)",
+                       (void *)exception_object, (void *)(uintptr_t)stop);
+  unw_context_t uc;
+  unw_cursor_t cursor;
+  __unw_getcontext(&uc);
+
+  // Mark that this is a forced unwind, so _Unwind_Resume() can do
+  // the right thing.
+  exception_object->unwinder_cache.reserved1 = (uintptr_t)stop;
+  exception_object->unwinder_cache.reserved3 = (uintptr_t)stop_parameter;
+
+  return unwind_phase2_forced(&uc, &cursor, exception_object, stop,
+                              stop_parameter);
+}
+
 /// Called by personality handler during phase 2 to find the start of the
 /// function.
 _LIBUNWIND_EXPORT uintptr_t
diff --git a/libunwind/src/Unwind-EHABI.h b/libunwind/src/Unwind-EHABI.h
index 6897082a337f..ff3b5fc6fea7 100644
--- a/libunwind/src/Unwind-EHABI.h
+++ b/libunwind/src/Unwind-EHABI.h
@@ -1,4 +1,4 @@
-//===------------------------- Unwind-EHABI.hpp ---------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
diff --git a/libunwind/src/Unwind-seh.cpp b/libunwind/src/Unwind-seh.cpp
index 6e2b4e73e41e..f00bc4721ba4 100644
--- a/libunwind/src/Unwind-seh.cpp
+++ b/libunwind/src/Unwind-seh.cpp
@@ -1,4 +1,4 @@
-//===--------------------------- Unwind-seh.cpp ---------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -169,8 +169,8 @@ _GCC_specific_handler(PEXCEPTION_RECORD ms_exc, PVOID frame, PCONTEXT ms_ctx,
     __unw_get_reg(&cursor, UNW_ARM_R1, &exc->private_[3]);
 #elif defined(__aarch64__)
     exc->private_[2] = disp->TargetPc;
-    __unw_get_reg(&cursor, UNW_ARM64_X0, &retval);
-    __unw_get_reg(&cursor, UNW_ARM64_X1, &exc->private_[3]);
+    __unw_get_reg(&cursor, UNW_AARCH64_X0, &retval);
+    __unw_get_reg(&cursor, UNW_AARCH64_X1, &exc->private_[3]);
 #endif
     __unw_get_reg(&cursor, UNW_REG_IP, &target);
     ms_exc->ExceptionCode = STATUS_GCC_UNWIND;
@@ -244,6 +244,7 @@ unwind_phase2_forced(unw_context_t *uc,
       return _URC_FATAL_PHASE2_ERROR;
     }
 
+#ifndef NDEBUG
     // When tracing, print state information.
     if (_LIBUNWIND_TRACING_UNWINDING) {
       char functionBuf[512];
@@ -259,6 +260,7 @@ unwind_phase2_forced(unw_context_t *uc,
           (void *)exception_object, frameInfo.start_ip, functionName,
           frameInfo.lsda, frameInfo.handler);
     }
+#endif
 
     // Call stop function at each frame.
     _Unwind_Action action =
diff --git a/libunwind/src/Unwind-sjlj.c b/libunwind/src/Unwind-sjlj.c
index fd2a95b74c44..d487995bb78e 100644
--- a/libunwind/src/Unwind-sjlj.c
+++ b/libunwind/src/Unwind-sjlj.c
@@ -1,4 +1,4 @@
-//===--------------------------- Unwind-sjlj.c ----------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
diff --git a/libunwind/src/UnwindCursor.hpp b/libunwind/src/UnwindCursor.hpp
index 757d9808a978..3931df0b3351 100644
--- a/libunwind/src/UnwindCursor.hpp
+++ b/libunwind/src/UnwindCursor.hpp
@@ -1,4 +1,4 @@
-//===------------------------- UnwindCursor.hpp ---------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -11,6 +11,7 @@
 #ifndef __UNWINDCURSOR_HPP__
 #define __UNWINDCURSOR_HPP__
 
+#include "cet_unwind.h"
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -449,6 +450,12 @@ public:
 #ifdef __arm__
   virtual void saveVFPAsX() { _LIBUNWIND_ABORT("saveVFPAsX not implemented"); }
 #endif
+
+#if defined(_LIBUNWIND_USE_CET)
+  virtual void *get_registers() {
+    _LIBUNWIND_ABORT("get_registers not implemented");
+  }
+#endif
 };
 
 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32)
@@ -620,12 +627,12 @@ UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as)
     _msContext.D[i - UNW_ARM_D0] = d.w;
   }
 #elif defined(_LIBUNWIND_TARGET_AARCH64)
-  for (int i = UNW_ARM64_X0; i <= UNW_ARM64_X30; ++i)
-    _msContext.X[i - UNW_ARM64_X0] = r.getRegister(i);
+  for (int i = UNW_AARCH64_X0; i <= UNW_ARM64_X30; ++i)
+    _msContext.X[i - UNW_AARCH64_X0] = r.getRegister(i);
   _msContext.Sp = r.getRegister(UNW_REG_SP);
   _msContext.Pc = r.getRegister(UNW_REG_IP);
-  for (int i = UNW_ARM64_D0; i <= UNW_ARM64_D31; ++i)
-    _msContext.V[i - UNW_ARM64_D0].D[0] = r.getFloatRegister(i);
+  for (int i = UNW_AARCH64_V0; i <= UNW_ARM64_D31; ++i)
+    _msContext.V[i - UNW_AARCH64_V0].D[0] = r.getFloatRegister(i);
 #endif
 }
 
@@ -650,7 +657,7 @@ bool UnwindCursor<A, R>::validReg(int regNum) {
 #elif defined(_LIBUNWIND_TARGET_ARM)
   if (regNum >= UNW_ARM_R0 && regNum <= UNW_ARM_R15) return true;
 #elif defined(_LIBUNWIND_TARGET_AARCH64)
-  if (regNum >= UNW_ARM64_X0 && regNum <= UNW_ARM64_X30) return true;
+  if (regNum >= UNW_AARCH64_X0 && regNum <= UNW_ARM64_X30) return true;
 #endif
   return false;
 }
@@ -699,7 +706,7 @@ unw_word_t UnwindCursor<A, R>::getReg(int regNum) {
 #elif defined(_LIBUNWIND_TARGET_AARCH64)
   case UNW_REG_SP: return _msContext.Sp;
   case UNW_REG_IP: return _msContext.Pc;
-  default: return _msContext.X[regNum - UNW_ARM64_X0];
+  default: return _msContext.X[regNum - UNW_AARCH64_X0];
 #endif
   }
   _LIBUNWIND_ABORT("unsupported register");
@@ -749,37 +756,37 @@ void UnwindCursor<A, R>::setReg(int regNum, unw_word_t value) {
 #elif defined(_LIBUNWIND_TARGET_AARCH64)
   case UNW_REG_SP: _msContext.Sp = value; break;
   case UNW_REG_IP: _msContext.Pc = value; break;
-  case UNW_ARM64_X0:
-  case UNW_ARM64_X1:
-  case UNW_ARM64_X2:
-  case UNW_ARM64_X3:
-  case UNW_ARM64_X4:
-  case UNW_ARM64_X5:
-  case UNW_ARM64_X6:
-  case UNW_ARM64_X7:
-  case UNW_ARM64_X8:
-  case UNW_ARM64_X9:
-  case UNW_ARM64_X10:
-  case UNW_ARM64_X11:
-  case UNW_ARM64_X12:
-  case UNW_ARM64_X13:
-  case UNW_ARM64_X14:
-  case UNW_ARM64_X15:
-  case UNW_ARM64_X16:
-  case UNW_ARM64_X17:
-  case UNW_ARM64_X18:
-  case UNW_ARM64_X19:
-  case UNW_ARM64_X20:
-  case UNW_ARM64_X21:
-  case UNW_ARM64_X22:
-  case UNW_ARM64_X23:
-  case UNW_ARM64_X24:
-  case UNW_ARM64_X25:
-  case UNW_ARM64_X26:
-  case UNW_ARM64_X27:
-  case UNW_ARM64_X28:
-  case UNW_ARM64_FP:
-  case UNW_ARM64_LR: _msContext.X[regNum - UNW_ARM64_X0] = value; break;
+  case UNW_AARCH64_X0:
+  case UNW_AARCH64_X1:
+  case UNW_AARCH64_X2:
+  case UNW_AARCH64_X3:
+  case UNW_AARCH64_X4:
+  case UNW_AARCH64_X5:
+  case UNW_AARCH64_X6:
+  case UNW_AARCH64_X7:
+  case UNW_AARCH64_X8:
+  case UNW_AARCH64_X9:
+  case UNW_AARCH64_X10:
+  case UNW_AARCH64_X11:
+  case UNW_AARCH64_X12:
+  case UNW_AARCH64_X13:
+  case UNW_AARCH64_X14:
+  case UNW_AARCH64_X15:
+  case UNW_AARCH64_X16:
+  case UNW_AARCH64_X17:
+  case UNW_AARCH64_X18:
+  case UNW_AARCH64_X19:
+  case UNW_AARCH64_X20:
+  case UNW_AARCH64_X21:
+  case UNW_AARCH64_X22:
+  case UNW_AARCH64_X23:
+  case UNW_AARCH64_X24:
+  case UNW_AARCH64_X25:
+  case UNW_AARCH64_X26:
+  case UNW_AARCH64_X27:
+  case UNW_AARCH64_X28:
+  case UNW_AARCH64_FP:
+  case UNW_AARCH64_LR: _msContext.X[regNum - UNW_ARM64_X0] = value; break;
 #endif
   default:
     _LIBUNWIND_ABORT("unsupported register");
@@ -792,7 +799,7 @@ bool UnwindCursor<A, R>::validFloatReg(int regNum) {
   if (regNum >= UNW_ARM_S0 && regNum <= UNW_ARM_S31) return true;
   if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) return true;
 #elif defined(_LIBUNWIND_TARGET_AARCH64)
-  if (regNum >= UNW_ARM64_D0 && regNum <= UNW_ARM64_D31) return true;
+  if (regNum >= UNW_AARCH64_V0 && regNum <= UNW_ARM64_D31) return true;
 #else
   (void)regNum;
 #endif
@@ -820,7 +827,7 @@ unw_fpreg_t UnwindCursor<A, R>::getFloatReg(int regNum) {
   }
   _LIBUNWIND_ABORT("unsupported float register");
 #elif defined(_LIBUNWIND_TARGET_AARCH64)
-  return _msContext.V[regNum - UNW_ARM64_D0].D[0];
+  return _msContext.V[regNum - UNW_AARCH64_V0].D[0];
 #else
   (void)regNum;
   _LIBUNWIND_ABORT("float registers unimplemented");
@@ -848,7 +855,7 @@ void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) {
   }
   _LIBUNWIND_ABORT("unsupported float register");
 #elif defined(_LIBUNWIND_TARGET_AARCH64)
-  _msContext.V[regNum - UNW_ARM64_D0].D[0] = value;
+  _msContext.V[regNum - UNW_AARCH64_V0].D[0] = value;
 #else
   (void)regNum;
   (void)value;
@@ -901,6 +908,9 @@ public:
   virtual void        saveVFPAsX();
 #endif
 
+#if defined(_LIBUNWIND_USE_CET)
+  virtual void *get_registers() { return &_registers; }
+#endif
   // libunwind does not and should not depend on C++ library which means that we
   // need our own defition of inline placement new.
   static void *operator new(size_t, UnwindCursor<A, R> *p) { return p; }
@@ -2061,7 +2071,7 @@ int UnwindCursor<A, R>::stepThroughSigReturn(Registers_arm64 &) {
   for (int i = 0; i <= 30; ++i) {
     uint64_t value = _addressSpace.get64(sigctx + kOffsetGprs +
                                          static_cast<pint_t>(i * 8));
-    _registers.setRegister(UNW_ARM64_X0 + i, value);
+    _registers.setRegister(UNW_AARCH64_X0 + i, value);
   }
   _registers.setSP(_addressSpace.get64(sigctx + kOffsetSp));
   _registers.setIP(_addressSpace.get64(sigctx + kOffsetPc));
@@ -2125,6 +2135,12 @@ bool UnwindCursor<A, R>::getFunctionName(char *buf, size_t bufLen,
                                          buf, bufLen, offset);
 }
 
+#if defined(_LIBUNWIND_USE_CET)
+extern "C" void *__libunwind_cet_get_registers(unw_cursor_t *cursor) {
+  AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
+  return co->get_registers();
+}
+#endif
 } // namespace libunwind
 
 #endif // __UNWINDCURSOR_HPP__
diff --git a/libunwind/src/UnwindLevel1-gcc-ext.c b/libunwind/src/UnwindLevel1-gcc-ext.c
index 310b836d129e..951d5d219a3e 100644
--- a/libunwind/src/UnwindLevel1-gcc-ext.c
+++ b/libunwind/src/UnwindLevel1-gcc-ext.c
@@ -1,4 +1,4 @@
-//===--------------------- UnwindLevel1-gcc-ext.c -------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -25,31 +25,24 @@
 #if defined(_LIBUNWIND_BUILD_ZERO_COST_APIS)
 
 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
-#define private_1 private_[0]
+#define PRIVATE_1 private_[0]
+#elif defined(_LIBUNWIND_ARM_EHABI)
+#define PRIVATE_1 unwinder_cache.reserved1
+#else
+#define PRIVATE_1 private_1
 #endif
 
 ///  Called by __cxa_rethrow().
 _LIBUNWIND_EXPORT _Unwind_Reason_Code
 _Unwind_Resume_or_Rethrow(_Unwind_Exception *exception_object) {
-#if defined(_LIBUNWIND_ARM_EHABI)
-  _LIBUNWIND_TRACE_API("_Unwind_Resume_or_Rethrow(ex_obj=%p), private_1=%ld",
-                       (void *)exception_object,
-                       (long)exception_object->unwinder_cache.reserved1);
-#else
-  _LIBUNWIND_TRACE_API("_Unwind_Resume_or_Rethrow(ex_obj=%p), private_1=%" PRIdPTR,
-                       (void *)exception_object,
-                       (intptr_t)exception_object->private_1);
-#endif
+  _LIBUNWIND_TRACE_API(
+      "_Unwind_Resume_or_Rethrow(ex_obj=%p), private_1=%" PRIdPTR,
+      (void *)exception_object, (intptr_t)exception_object->PRIVATE_1);
 
-#if defined(_LIBUNWIND_ARM_EHABI)
-  // _Unwind_RaiseException on EHABI will always set the reserved1 field to 0,
-  // which is in the same position as private_1 below.
-  return _Unwind_RaiseException(exception_object);
-#else
   // If this is non-forced and a stopping place was found, then this is a
   // re-throw.
   // Call _Unwind_RaiseException() as if this was a new exception
-  if (exception_object->private_1 == 0) {
+  if (exception_object->PRIVATE_1 == 0) {
     return _Unwind_RaiseException(exception_object);
     // Will return if there is no catch clause, so that __cxa_rethrow can call
     // std::terminate().
@@ -60,10 +53,8 @@ _Unwind_Resume_or_Rethrow(_Unwind_Exception *exception_object) {
   _Unwind_Resume(exception_object);
   _LIBUNWIND_ABORT("_Unwind_Resume_or_Rethrow() called _Unwind_RaiseException()"
                    " which unexpectedly returned");
-#endif
 }
 
-
 /// Called by personality handler during phase 2 to get base address for data
 /// relative encodings.
 _LIBUNWIND_EXPORT uintptr_t
@@ -118,7 +109,7 @@ _Unwind_Backtrace(_Unwind_Trace_Fn callback, void *ref) {
   // Create a mock exception object for force unwinding.
   _Unwind_Exception ex;
   memset(&ex, '\0', sizeof(ex));
-  ex.exception_class = 0x434C4E47554E5700; // CLNGUNW\0
+  strcpy((char *)&ex.exception_class, "CLNGUNW");
 #endif
 
   // walk each frame
diff --git a/libunwind/src/UnwindLevel1.c b/libunwind/src/UnwindLevel1.c
index 68e5e48b8c05..5c1f99d4bfa5 100644
--- a/libunwind/src/UnwindLevel1.c
+++ b/libunwind/src/UnwindLevel1.c
@@ -1,4 +1,4 @@
-//===------------------------- UnwindLevel1.c -----------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -25,6 +25,7 @@
 #include <stdio.h>
 #include <string.h>
 
+#include "cet_unwind.h"
 #include "config.h"
 #include "libunwind.h"
 #include "libunwind_ext.h"
@@ -34,6 +35,38 @@
 
 #ifndef _LIBUNWIND_SUPPORT_SEH_UNWIND
 
+// When CET is enabled, each "call" instruction will push return address to
+// CET shadow stack, each "ret" instruction will pop current CET shadow stack
+// top and compare it with target address which program will return.
+// In exception handing, some stack frames will be skipped before jumping to
+// landing pad and we must adjust CET shadow stack accordingly.
+// _LIBUNWIND_POP_CET_SSP is used to adjust CET shadow stack pointer and we
+// directly jump to __libunwind_Registerts_x86/x86_64_jumpto instead of using
+// a regular function call to avoid pushing to CET shadow stack again.
+#if !defined(_LIBUNWIND_USE_CET)
+#define __unw_phase2_resume(cursor, fn) __unw_resume((cursor))
+#elif defined(_LIBUNWIND_TARGET_I386)
+#define __unw_phase2_resume(cursor, fn)                                        \
+  do {                                                                         \
+    _LIBUNWIND_POP_CET_SSP((fn));                                              \
+    void *cetRegContext = __libunwind_cet_get_registers((cursor));             \
+    void *cetJumpAddress = __libunwind_cet_get_jump_target();                  \
+    __asm__ volatile("push %%edi\n\t"                                          \
+                     "sub $4, %%esp\n\t"                                       \
+                     "jmp *%%edx\n\t" :: "D"(cetRegContext),                   \
+                     "d"(cetJumpAddress));                                     \
+  } while (0)
+#elif defined(_LIBUNWIND_TARGET_X86_64)
+#define __unw_phase2_resume(cursor, fn)                                        \
+  do {                                                                         \
+    _LIBUNWIND_POP_CET_SSP((fn));                                              \
+    void *cetRegContext = __libunwind_cet_get_registers((cursor));             \
+    void *cetJumpAddress = __libunwind_cet_get_jump_target();                  \
+    __asm__ volatile("jmpq *%%rdx\n\t" :: "D"(cetRegContext),                  \
+                     "d"(cetJumpAddress));                                     \
+  } while (0)
+#endif
+
 static _Unwind_Reason_Code
 unwind_phase1(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *exception_object) {
   __unw_init_local(cursor, uc);
@@ -68,6 +101,7 @@ unwind_phase1(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *except
       return _URC_FATAL_PHASE1_ERROR;
     }
 
+#ifndef NDEBUG
     // When tracing, print state information.
     if (_LIBUNWIND_TRACING_UNWINDING) {
       char functionBuf[512];
@@ -85,6 +119,7 @@ unwind_phase1(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *except
           (void *)exception_object, pc, frameInfo.start_ip, functionName,
           frameInfo.lsda, frameInfo.handler);
     }
+#endif
 
     // If there is a personality routine, ask it if it will want to stop at
     // this frame.
@@ -135,6 +170,9 @@ unwind_phase2(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *except
   _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p)",
                              (void *)exception_object);
 
+  // uc is initialized by __unw_getcontext in the parent frame. The first stack
+  // frame walked is unwind_phase2.
+  unsigned framesWalked = 1;
   // Walk each frame until we reach where search phase said to stop.
   while (true) {
 
@@ -167,6 +205,7 @@ unwind_phase2(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *except
       return _URC_FATAL_PHASE2_ERROR;
     }
 
+#ifndef NDEBUG
     // When tracing, print state information.
     if (_LIBUNWIND_TRACING_UNWINDING) {
       char functionBuf[512];
@@ -183,7 +222,9 @@ unwind_phase2(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *except
                                  functionName, sp, frameInfo.lsda,
                                  frameInfo.handler);
     }
+#endif
 
+    ++framesWalked;
     // If there is a personality routine, tell it we are unwinding.
     if (frameInfo.handler != 0) {
       _Unwind_Personality_Fn p =
@@ -223,8 +264,9 @@ unwind_phase2(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *except
                                      ", sp=0x%" PRIxPTR,
                                      (void *)exception_object, pc, sp);
         }
-        __unw_resume(cursor);
-        // __unw_resume() only returns if there was an error.
+
+        __unw_phase2_resume(cursor, framesWalked);
+        // __unw_phase2_resume() only returns if there was an error.
         return _URC_FATAL_PHASE2_ERROR;
       default:
         // Personality routine returned an unknown result code.
@@ -246,6 +288,9 @@ unwind_phase2_forced(unw_context_t *uc, unw_cursor_t *cursor,
                      _Unwind_Stop_Fn stop, void *stop_parameter) {
   __unw_init_local(cursor, uc);
 
+  // uc is initialized by __unw_getcontext in the parent frame. The first stack
+  // frame walked is unwind_phase2_forced.
+  unsigned framesWalked = 1;
   // Walk each frame until we reach where search phase said to stop
   while (__unw_step(cursor) > 0) {
 
@@ -258,6 +303,7 @@ unwind_phase2_forced(unw_context_t *uc, unw_cursor_t *cursor,
       return _URC_FATAL_PHASE2_ERROR;
     }
 
+#ifndef NDEBUG
     // When tracing, print state information.
     if (_LIBUNWIND_TRACING_UNWINDING) {
       char functionBuf[512];
@@ -273,6 +319,7 @@ unwind_phase2_forced(unw_context_t *uc, unw_cursor_t *cursor,
           (void *)exception_object, frameInfo.start_ip, functionName,
           frameInfo.lsda, frameInfo.handler);
     }
+#endif
 
     // Call stop function at each frame.
     _Unwind_Action action =
@@ -290,6 +337,7 @@ unwind_phase2_forced(unw_context_t *uc, unw_cursor_t *cursor,
       return _URC_FATAL_PHASE2_ERROR;
     }
 
+    ++framesWalked;
     // If there is a personality routine, tell it we are unwinding.
     if (frameInfo.handler != 0) {
       _Unwind_Personality_Fn p =
@@ -314,7 +362,7 @@ unwind_phase2_forced(unw_context_t *uc, unw_cursor_t *cursor,
                                    "_URC_INSTALL_CONTEXT",
                                    (void *)exception_object);
         // We may get control back if landing pad calls _Unwind_Resume().
-        __unw_resume(cursor);
+        __unw_phase2_resume(cursor, framesWalked);
         break;
       default:
         // Personality routine returned an unknown result code.
diff --git a/libunwind/src/UnwindRegistersRestore.S b/libunwind/src/UnwindRegistersRestore.S
index d8bf1adee416..497bf46dbdd4 100644
--- a/libunwind/src/UnwindRegistersRestore.S
+++ b/libunwind/src/UnwindRegistersRestore.S
@@ -1,4 +1,4 @@
-//===-------------------- UnwindRegistersRestore.S ------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -25,6 +25,8 @@ DEFINE_LIBUNWIND_FUNCTION(__libunwind_Registers_x86_jumpto)
 #  + return address        +
 #  +-----------------------+   <-- SP
 #  +                       +
+
+  _LIBUNWIND_CET_ENDBR
   movl   4(%esp), %eax
   # set up eax and ret on new stack location
   movl  28(%eax), %edx # edx holds new stack pointer
@@ -46,7 +48,8 @@ DEFINE_LIBUNWIND_FUNCTION(__libunwind_Registers_x86_jumpto)
   # skip ss
   # skip eflags
   pop    %eax  # eax was already pushed on new stack
-  ret        # eip was already pushed on new stack
+  pop    %ecx
+  jmp    *%ecx
   # skip cs
   # skip ds
   # skip es
@@ -70,6 +73,7 @@ DEFINE_LIBUNWIND_FUNCTION(__libunwind_Registers_x86_64_jumpto)
 # On entry, thread_state pointer is in rdi
 #endif
 
+  _LIBUNWIND_CET_ENDBR
   movq  56(%rdi), %rax # rax holds new stack pointer
   subq  $16, %rax
   movq  %rax, 56(%rdi)
@@ -119,7 +123,8 @@ DEFINE_LIBUNWIND_FUNCTION(__libunwind_Registers_x86_64_jumpto)
 #endif
   movq  56(%rdi), %rsp  # cut back rsp to new location
   pop    %rdi      # rdi was saved here earlier
-  ret            # rip was saved here
+  pop    %rcx
+  jmpq   *%rcx
 
 
 #elif defined(__powerpc64__)
@@ -800,11 +805,12 @@ DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind14Registers_or1k6jumptoEv)
   l.lwz    r30,120(r3)
   l.lwz    r31,124(r3)
 
+  # load new pc into ra
+  l.lwz    r9, 128(r3)
+
   # at last, restore r3
   l.lwz    r3,  12(r3)
 
-  # load new pc into ra
-  l.lwz    r9, 128(r3)
   # jump to pc
   l.jr     r9
    l.nop
diff --git a/libunwind/src/UnwindRegistersSave.S b/libunwind/src/UnwindRegistersSave.S
index f66dc532c23c..e77012e5c613 100644
--- a/libunwind/src/UnwindRegistersSave.S
+++ b/libunwind/src/UnwindRegistersSave.S
@@ -1,4 +1,4 @@
-//===------------------------ UnwindRegistersSave.S -----------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -27,6 +27,8 @@
 #   +                       +
 #
 DEFINE_LIBUNWIND_FUNCTION(__unw_getcontext)
+
+  _LIBUNWIND_CET_ENDBR
   push  %eax
   movl  8(%esp), %eax
   movl  %ebx,  4(%eax)
@@ -70,6 +72,7 @@ DEFINE_LIBUNWIND_FUNCTION(__unw_getcontext)
 #define TMP %rsi
 #endif
 
+  _LIBUNWIND_CET_ENDBR
   movq  %rax,   (PTR)
   movq  %rbx,  8(PTR)
   movq  %rcx, 16(PTR)
diff --git a/libunwind/src/Unwind_AppleExtras.cpp b/libunwind/src/Unwind_AppleExtras.cpp
index e3d41ca2b4e9..ffb49a89e54f 100644
--- a/libunwind/src/Unwind_AppleExtras.cpp
+++ b/libunwind/src/Unwind_AppleExtras.cpp
@@ -1,4 +1,4 @@
-//===--------------------- Unwind_AppleExtras.cpp -------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
diff --git a/libunwind/src/assembly.h b/libunwind/src/assembly.h
index 76ef82553283..e38d32336929 100644
--- a/libunwind/src/assembly.h
+++ b/libunwind/src/assembly.h
@@ -15,6 +15,13 @@
 #ifndef UNWIND_ASSEMBLY_H
 #define UNWIND_ASSEMBLY_H
 
+#if (defined(__i386__) || defined(__x86_64__)) && defined(__linux__)
+#include <cet.h>
+#define _LIBUNWIND_CET_ENDBR _CET_ENDBR
+#else
+#define _LIBUNWIND_CET_ENDBR
+#endif
+
 #if defined(__powerpc64__)
 #define SEPARATOR ;
 #define PPC64_OFFS_SRR0   0
diff --git a/libunwind/src/cet_unwind.h b/libunwind/src/cet_unwind.h
new file mode 100644
index 000000000000..e371be20c452
--- /dev/null
+++ b/libunwind/src/cet_unwind.h
@@ -0,0 +1,41 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LIBUNWIND_CET_UNWIND_H
+#define LIBUNWIND_CET_UNWIND_H
+
+#include "libunwind.h"
+
+// Currently, CET is implemented on Linux x86 platforms.
+#if defined(_LIBUNWIND_TARGET_LINUX) && defined(__CET__) && defined(__SHSTK__)
+#define _LIBUNWIND_USE_CET 1
+#endif
+
+#if defined(_LIBUNWIND_USE_CET)
+#include <cet.h>
+#include <immintrin.h>
+
+#define _LIBUNWIND_POP_CET_SSP(x)                                              \
+  do {                                                                         \
+    unsigned long ssp = _get_ssp();                                            \
+    if (ssp != 0) {                                                            \
+      unsigned int tmp = (x);                                                  \
+      while (tmp > 255) {                                                      \
+        _inc_ssp(255);                                                         \
+        tmp -= 255;                                                            \
+      }                                                                        \
+      _inc_ssp(tmp);                                                           \
+    }                                                                          \
+  } while (0)
+#endif
+
+extern void *__libunwind_cet_get_registers(unw_cursor_t *);
+extern void *__libunwind_cet_get_jump_target();
+
+#endif
diff --git a/libunwind/src/config.h b/libunwind/src/config.h
index 2ab9d2f5e0c9..f469d3c232e6 100644
--- a/libunwind/src/config.h
+++ b/libunwind/src/config.h
@@ -1,4 +1,4 @@
-//===----------------------------- config.h -------------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
diff --git a/libunwind/src/dwarf2.h b/libunwind/src/dwarf2.h
index 40f0daf46805..174277d5a795 100644
--- a/libunwind/src/dwarf2.h
+++ b/libunwind/src/dwarf2.h
@@ -1,4 +1,4 @@
-//===------------------------------- dwarf2.h -----------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
diff --git a/libunwind/src/libunwind.cpp b/libunwind/src/libunwind.cpp
index 1faf000ce44a..48750ce670fb 100644
--- a/libunwind/src/libunwind.cpp
+++ b/libunwind/src/libunwind.cpp
@@ -1,4 +1,4 @@
-//===--------------------------- libunwind.cpp ----------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -11,8 +11,8 @@
 
 #include <libunwind.h>
 
-#include "libunwind_ext.h"
 #include "config.h"
+#include "libunwind_ext.h"
 
 #include <stdlib.h>
 
@@ -292,6 +292,35 @@ void __unw_remove_dynamic_fde(unw_word_t fde) {
   // fde is own mh_group
   DwarfFDECache<LocalAddressSpace>::removeAllIn((LocalAddressSpace::pint_t)fde);
 }
+
+void __unw_add_dynamic_eh_frame_section(unw_word_t eh_frame_start) {
+  // The eh_frame section start serves as the mh_group
+  unw_word_t mh_group = eh_frame_start;
+  CFI_Parser<LocalAddressSpace>::CIE_Info cieInfo;
+  CFI_Parser<LocalAddressSpace>::FDE_Info fdeInfo;
+  auto p = (LocalAddressSpace::pint_t)eh_frame_start;
+  while (true) {
+    if (CFI_Parser<LocalAddressSpace>::decodeFDE(
+            LocalAddressSpace::sThisAddressSpace, p, &fdeInfo, &cieInfo,
+            true) == NULL) {
+      DwarfFDECache<LocalAddressSpace>::add((LocalAddressSpace::pint_t)mh_group,
+                                            fdeInfo.pcStart, fdeInfo.pcEnd,
+                                            fdeInfo.fdeStart);
+      p += fdeInfo.fdeLength;
+    } else if (CFI_Parser<LocalAddressSpace>::parseCIE(
+                   LocalAddressSpace::sThisAddressSpace, p, &cieInfo) == NULL) {
+      p += cieInfo.cieLength;
+    } else
+      return;
+  }
+}
+
+void __unw_remove_dynamic_eh_frame_section(unw_word_t eh_frame_start) {
+  // The eh_frame section start serves as the mh_group
+  DwarfFDECache<LocalAddressSpace>::removeAllIn(
+      (LocalAddressSpace::pint_t)eh_frame_start);
+}
+
 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
 #endif // !defined(__USING_SJLJ_EXCEPTIONS__)
 
diff --git a/libunwind/src/libunwind_ext.h b/libunwind/src/libunwind_ext.h
index 316dee298246..7065ffcdaeff 100644
--- a/libunwind/src/libunwind_ext.h
+++ b/libunwind/src/libunwind_ext.h
@@ -1,4 +1,4 @@
-//===------------------------ libunwind_ext.h -----------------------------===//
+//===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -51,6 +51,9 @@ extern void __unw_iterate_dwarf_unwind_cache(void (*func)(
 extern void __unw_add_dynamic_fde(unw_word_t fde);
 extern void __unw_remove_dynamic_fde(unw_word_t fde);
 
+extern void __unw_add_dynamic_eh_frame_section(unw_word_t eh_frame_start);
+extern void __unw_remove_dynamic_eh_frame_section(unw_word_t eh_frame_start);
+
 #if defined(_LIBUNWIND_ARM_EHABI)
 extern const uint32_t* decode_eht_entry(const uint32_t*, size_t*, size_t*);
 extern _Unwind_Reason_Code _Unwind_VRS_Interpret(_Unwind_Context *context,