MFC libunwind improvements

r302450: libunwind: update to upstream snapshot r272680

The key improvement is that it may be built without cross-unwinding
support, which significantly reduces the stack space requirement.

r302456: libunwind: enable only the native unwinder by default

This significantly reduces stack space requirements, and runtimes
require only native unwinding.

r302475: libunwind: limit stack usage in unwind cursor

This may be reworked upstream but in the interim should address the
stack usage issue reported in the PR.

r303016: llvm-libunwind: use conventional (non-Darwin) X86 register numbers

For historical reasons Darwin/i386 has ebp and esp swapped in the
eh_frame register numbering.  That is:

              Darwin      Other
    Reg #    eh_frame    eh_frame    DWARF
    =====    ========    ========    =====
      4        ebp         esp        esp
      5        esp         ebp        ebp

Although the UNW_X86_* constants are not supposed to be coupled to
DWARF / eh_frame numbering they are currently conflated in LLVM
libunwind, and thus we require the non-Darwin numbering.

PR:		206384
Approved by:	re (kib)
Sponsored by:	The FreeBSD Foundation

12 files changed, 582 insertions, 508 deletions

diff --git a/contrib/llvm/projects/libunwind/include/__libunwind_config.h b/contrib/llvm/projects/libunwind/include/__libunwind_config.h
index 63393d3..9b87bcb 100644
--- a/contrib/llvm/projects/libunwind/include/__libunwind_config.h
+++ b/contrib/llvm/projects/libunwind/include/__libunwind_config.h
@@ -17,4 +17,47 @@
 #define _LIBUNWIND_ARM_EHABI 0
 #endif
 
+#if defined(_LIBUNWIND_IS_NATIVE_ONLY)
+# if defined(__i386__)
+#  define _LIBUNWIND_TARGET_I386 1
+#  define _LIBUNWIND_CONTEXT_SIZE 8
+#  define _LIBUNWIND_CURSOR_SIZE 19
+# elif defined(__x86_64__)
+#  define _LIBUNWIND_TARGET_X86_64 1
+#  define _LIBUNWIND_CONTEXT_SIZE 21
+#  define _LIBUNWIND_CURSOR_SIZE 33
+# elif defined(__ppc__)
+#  define _LIBUNWIND_TARGET_PPC 1
+#  define _LIBUNWIND_CONTEXT_SIZE 117
+#  define _LIBUNWIND_CURSOR_SIZE 128
+# elif defined(__aarch64__)
+#  define _LIBUNWIND_TARGET_AARCH64 1
+#  define _LIBUNWIND_CONTEXT_SIZE 66
+#  define _LIBUNWIND_CURSOR_SIZE 78
+# elif defined(__arm__)
+#  define _LIBUNWIND_TARGET_ARM 1
+#  define _LIBUNWIND_CONTEXT_SIZE 60
+#  define _LIBUNWIND_CURSOR_SIZE 67
+# elif defined(__or1k__)
+#  define _LIBUNWIND_TARGET_OR1K 1
+#  define _LIBUNWIND_CONTEXT_SIZE 16
+#  define _LIBUNWIND_CURSOR_SIZE 28
+# elif defined(__riscv__)
+#  define _LIBUNWIND_TARGET_RISCV 1
+#  define _LIBUNWIND_CONTEXT_SIZE 128 /* XXX */
+#  define _LIBUNWIND_CURSOR_SIZE 140 /* XXX */
+# else
+#  error "Unsupported architecture."
+# endif
+#else // !_LIBUNWIND_IS_NATIVE_ONLY
+# define _LIBUNWIND_TARGET_I386 1
+# define _LIBUNWIND_TARGET_X86_64 1
+# define _LIBUNWIND_TARGET_PPC 1
+# define _LIBUNWIND_TARGET_AARCH64 1
+# define _LIBUNWIND_TARGET_ARM 1
+# define _LIBUNWIND_TARGET_OR1K 1
+# define _LIBUNWIND_CONTEXT_SIZE 128
+# define _LIBUNWIND_CURSOR_SIZE 140
+#endif // _LIBUNWIND_IS_NATIVE_ONLY
+
 #endif // ____LIBUNWIND_CONFIG_H__
diff --git a/contrib/llvm/projects/libunwind/include/libunwind.h b/contrib/llvm/projects/libunwind/include/libunwind.h
index 4f08381..64534b1 100644
--- a/contrib/llvm/projects/libunwind/include/libunwind.h
+++ b/contrib/llvm/projects/libunwind/include/libunwind.h
@@ -46,12 +46,12 @@ enum {
 };
 
 struct unw_context_t {
-  uint64_t data[128];
+  uint64_t data[_LIBUNWIND_CONTEXT_SIZE];
 };
 typedef struct unw_context_t unw_context_t;
 
 struct unw_cursor_t {
-  uint64_t data[140];
+  uint64_t data[_LIBUNWIND_CURSOR_SIZE];
 };
 typedef struct unw_cursor_t unw_cursor_t;
 
@@ -151,8 +151,8 @@ enum {
   UNW_X86_ECX = 1,
   UNW_X86_EDX = 2,
   UNW_X86_EBX = 3,
-  UNW_X86_EBP = 4,
-  UNW_X86_ESP = 5,
+  UNW_X86_ESP = 4,
+  UNW_X86_EBP = 5,
   UNW_X86_ESI = 6,
   UNW_X86_EDI = 7
 };
@@ -295,77 +295,6 @@ enum {
   UNW_PPC_SPEFSCR = 112
 };
 
-// 64-bit RISC-V registers
-enum {
-  UNW_RISCV_X0  = 0,
-  UNW_RISCV_X1  = 1,
-  UNW_RISCV_RA  = 1,
-  UNW_RISCV_X2  = 2,
-  UNW_RISCV_SP  = 2,
-  UNW_RISCV_X3  = 3,
-  UNW_RISCV_X4  = 4,
-  UNW_RISCV_X5  = 5,
-  UNW_RISCV_X6  = 6,
-  UNW_RISCV_X7  = 7,
-  UNW_RISCV_X8  = 8,
-  UNW_RISCV_X9  = 9,
-  UNW_RISCV_X10 = 10,
-  UNW_RISCV_X11 = 11,
-  UNW_RISCV_X12 = 12,
-  UNW_RISCV_X13 = 13,
-  UNW_RISCV_X14 = 14,
-  UNW_RISCV_X15 = 15,
-  UNW_RISCV_X16 = 16,
-  UNW_RISCV_X17 = 17,
-  UNW_RISCV_X18 = 18,
-  UNW_RISCV_X19 = 19,
-  UNW_RISCV_X20 = 20,
-  UNW_RISCV_X21 = 21,
-  UNW_RISCV_X22 = 22,
-  UNW_RISCV_X23 = 23,
-  UNW_RISCV_X24 = 24,
-  UNW_RISCV_X25 = 25,
-  UNW_RISCV_X26 = 26,
-  UNW_RISCV_X27 = 27,
-  UNW_RISCV_X28 = 28,
-  UNW_RISCV_X29 = 29,
-  UNW_RISCV_X30 = 30,
-  UNW_RISCV_X31 = 31,
-  // reserved block
-  UNW_RISCV_D0  = 64,
-  UNW_RISCV_D1  = 65,
-  UNW_RISCV_D2  = 66,
-  UNW_RISCV_D3  = 67,
-  UNW_RISCV_D4  = 68,
-  UNW_RISCV_D5  = 69,
-  UNW_RISCV_D6  = 70,
-  UNW_RISCV_D7  = 71,
-  UNW_RISCV_D8  = 72,
-  UNW_RISCV_D9  = 73,
-  UNW_RISCV_D10 = 74,
-  UNW_RISCV_D11 = 75,
-  UNW_RISCV_D12 = 76,
-  UNW_RISCV_D13 = 77,
-  UNW_RISCV_D14 = 78,
-  UNW_RISCV_D15 = 79,
-  UNW_RISCV_D16 = 80,
-  UNW_RISCV_D17 = 81,
-  UNW_RISCV_D18 = 82,
-  UNW_RISCV_D19 = 83,
-  UNW_RISCV_D20 = 84,
-  UNW_RISCV_D21 = 85,
-  UNW_RISCV_D22 = 86,
-  UNW_RISCV_D23 = 87,
-  UNW_RISCV_D24 = 88,
-  UNW_RISCV_D25 = 89,
-  UNW_RISCV_D26 = 90,
-  UNW_RISCV_D27 = 91,
-  UNW_RISCV_D28 = 92,
-  UNW_RISCV_D29 = 93,
-  UNW_RISCV_D30 = 94,
-  UNW_RISCV_D31 = 95,
-};
-
 // 64-bit ARM64 registers
 enum {
   UNW_ARM64_X0  = 0,
@@ -604,4 +533,75 @@ enum {
   UNW_OR1K_R31 = 31,
 };
 
+// 64-bit RISC-V registers
+enum {
+  UNW_RISCV_X0  = 0,
+  UNW_RISCV_X1  = 1,
+  UNW_RISCV_RA  = 1,
+  UNW_RISCV_X2  = 2,
+  UNW_RISCV_SP  = 2,
+  UNW_RISCV_X3  = 3,
+  UNW_RISCV_X4  = 4,
+  UNW_RISCV_X5  = 5,
+  UNW_RISCV_X6  = 6,
+  UNW_RISCV_X7  = 7,
+  UNW_RISCV_X8  = 8,
+  UNW_RISCV_X9  = 9,
+  UNW_RISCV_X10 = 10,
+  UNW_RISCV_X11 = 11,
+  UNW_RISCV_X12 = 12,
+  UNW_RISCV_X13 = 13,
+  UNW_RISCV_X14 = 14,
+  UNW_RISCV_X15 = 15,
+  UNW_RISCV_X16 = 16,
+  UNW_RISCV_X17 = 17,
+  UNW_RISCV_X18 = 18,
+  UNW_RISCV_X19 = 19,
+  UNW_RISCV_X20 = 20,
+  UNW_RISCV_X21 = 21,
+  UNW_RISCV_X22 = 22,
+  UNW_RISCV_X23 = 23,
+  UNW_RISCV_X24 = 24,
+  UNW_RISCV_X25 = 25,
+  UNW_RISCV_X26 = 26,
+  UNW_RISCV_X27 = 27,
+  UNW_RISCV_X28 = 28,
+  UNW_RISCV_X29 = 29,
+  UNW_RISCV_X30 = 30,
+  UNW_RISCV_X31 = 31,
+  // reserved block
+  UNW_RISCV_D0  = 64,
+  UNW_RISCV_D1  = 65,
+  UNW_RISCV_D2  = 66,
+  UNW_RISCV_D3  = 67,
+  UNW_RISCV_D4  = 68,
+  UNW_RISCV_D5  = 69,
+  UNW_RISCV_D6  = 70,
+  UNW_RISCV_D7  = 71,
+  UNW_RISCV_D8  = 72,
+  UNW_RISCV_D9  = 73,
+  UNW_RISCV_D10 = 74,
+  UNW_RISCV_D11 = 75,
+  UNW_RISCV_D12 = 76,
+  UNW_RISCV_D13 = 77,
+  UNW_RISCV_D14 = 78,
+  UNW_RISCV_D15 = 79,
+  UNW_RISCV_D16 = 80,
+  UNW_RISCV_D17 = 81,
+  UNW_RISCV_D18 = 82,
+  UNW_RISCV_D19 = 83,
+  UNW_RISCV_D20 = 84,
+  UNW_RISCV_D21 = 85,
+  UNW_RISCV_D22 = 86,
+  UNW_RISCV_D23 = 87,
+  UNW_RISCV_D24 = 88,
+  UNW_RISCV_D25 = 89,
+  UNW_RISCV_D26 = 90,
+  UNW_RISCV_D27 = 91,
+  UNW_RISCV_D28 = 92,
+  UNW_RISCV_D29 = 93,
+  UNW_RISCV_D30 = 94,
+  UNW_RISCV_D31 = 95,
+};
+
 #endif
diff --git a/contrib/llvm/projects/libunwind/src/AddressSpace.hpp b/contrib/llvm/projects/libunwind/src/AddressSpace.hpp
index 55828df..74294a3 100644
--- a/contrib/llvm/projects/libunwind/src/AddressSpace.hpp
+++ b/contrib/llvm/projects/libunwind/src/AddressSpace.hpp
@@ -35,7 +35,7 @@ namespace libunwind {
 #include "Registers.hpp"
 
 #if _LIBUNWIND_ARM_EHABI
-#if defined(__FreeBSD__)
+#if defined(__FreeBSD__) || defined(__NetBSD__)
 
 #include <sys/link_elf.h>
 typedef void *_Unwind_Ptr;
@@ -62,7 +62,8 @@ extern EHTEntry __exidx_end;
 #endif // !defined(_LIBUNWIND_IS_BAREMETAL)
 #endif // _LIBUNWIND_ARM_EHABI
 
-#if defined(__CloudABI__) || defined(__FreeBSD__) || defined(__linux__)
+#if defined(__CloudABI__) || defined(__FreeBSD__) || defined(__linux__) ||	\
+    defined(__NetBSD__)
 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND && _LIBUNWIND_SUPPORT_DWARF_INDEX
 #include <link.h>
 // Macro for machine-independent access to the ELF program headers. This
diff --git a/contrib/llvm/projects/libunwind/src/CompactUnwinder.hpp b/contrib/llvm/projects/libunwind/src/CompactUnwinder.hpp
index cd9ce3e..f528fba 100644
--- a/contrib/llvm/projects/libunwind/src/CompactUnwinder.hpp
+++ b/contrib/llvm/projects/libunwind/src/CompactUnwinder.hpp
@@ -27,6 +27,7 @@
 
 namespace libunwind {
 
+#if defined(_LIBUNWIND_TARGET_I386)
 /// CompactUnwinder_x86 uses a compact unwind info to virtually "step" (aka
 /// unwind) by modifying a Registers_x86 register set
 template <typename A>
@@ -255,8 +256,10 @@ void CompactUnwinder_x86<A>::framelessUnwind(
   // old esp is before return address
   registers.setSP((uint32_t)returnAddressLocation + 4);
 }
+#endif // _LIBUNWIND_TARGET_I386
 
 
+#if defined(_LIBUNWIND_TARGET_X86_64)
 /// CompactUnwinder_x86_64 uses a compact unwind info to virtually "step" (aka
 /// unwind) by modifying a Registers_x86_64 register set
 template <typename A>
@@ -484,9 +487,11 @@ void CompactUnwinder_x86_64<A>::framelessUnwind(A &addressSpace,
   // old esp is before return address
   registers.setSP(returnAddressLocation + 8);
 }
+#endif // _LIBUNWIND_TARGET_X86_64
 
 
 
+#if defined(_LIBUNWIND_TARGET_AARCH64)
 /// CompactUnwinder_arm64 uses a compact unwind info to virtually "step" (aka
 /// unwind) by modifying a Registers_arm64 register set
 template <typename A>
@@ -686,6 +691,7 @@ int CompactUnwinder_arm64<A>::stepWithCompactEncodingFrame(
 
   return UNW_STEP_SUCCESS;
 }
+#endif // _LIBUNWIND_TARGET_AARCH64
 
 
 } // namespace libunwind
diff --git a/contrib/llvm/projects/libunwind/src/Registers.hpp b/contrib/llvm/projects/libunwind/src/Registers.hpp
index 04bbfe6..e176298 100644
--- a/contrib/llvm/projects/libunwind/src/Registers.hpp
+++ b/contrib/llvm/projects/libunwind/src/Registers.hpp
@@ -25,6 +25,7 @@ namespace libunwind {
 struct v128 { uint32_t vec[4]; };
 
 
+#if defined(_LIBUNWIND_TARGET_I386)
 /// Registers_x86 holds the register state of a thread in a 32-bit intel
 /// process.
 class _LIBUNWIND_HIDDEN Registers_x86 {
@@ -86,8 +87,8 @@ private:
 };
 
 inline Registers_x86::Registers_x86(const void *registers) {
-  static_assert(sizeof(Registers_x86) < sizeof(unw_context_t),
-                    "x86 registers do not fit into unw_context_t");
+  static_assert((check_fit<Registers_x86, unw_context_t>::does_fit),
+                "x86 registers do not fit into unw_context_t");
   memcpy(&_registers, registers, sizeof(_registers));
 }
 
@@ -211,8 +212,10 @@ inline v128 Registers_x86::getVectorRegister(int) const {
 inline void Registers_x86::setVectorRegister(int, v128) {
   _LIBUNWIND_ABORT("no x86 vector registers");
 }
+#endif // _LIBUNWIND_TARGET_I386
 
 
+#if defined(_LIBUNWIND_TARGET_X86_64)
 /// Registers_x86_64  holds the register state of a thread in a 64-bit intel
 /// process.
 class _LIBUNWIND_HIDDEN Registers_x86_64 {
@@ -278,8 +281,8 @@ private:
 };
 
 inline Registers_x86_64::Registers_x86_64(const void *registers) {
-  static_assert(sizeof(Registers_x86_64) < sizeof(unw_context_t),
-                    "x86_64 registers do not fit into unw_context_t");
+  static_assert((check_fit<Registers_x86_64, unw_context_t>::does_fit),
+                "x86_64 registers do not fit into unw_context_t");
   memcpy(&_registers, registers, sizeof(_registers));
 }
 
@@ -459,8 +462,10 @@ inline v128 Registers_x86_64::getVectorRegister(int) const {
 inline void Registers_x86_64::setVectorRegister(int, v128) {
   _LIBUNWIND_ABORT("no x86_64 vector registers");
 }
+#endif // _LIBUNWIND_TARGET_X86_64
 
 
+#if defined(_LIBUNWIND_TARGET_PPC)
 /// Registers_ppc holds the register state of a thread in a 32-bit PowerPC
 /// process.
 class _LIBUNWIND_HIDDEN Registers_ppc {
@@ -543,8 +548,8 @@ private:
 };
 
 inline Registers_ppc::Registers_ppc(const void *registers) {
-  static_assert(sizeof(Registers_ppc) < sizeof(unw_context_t),
-                    "ppc registers do not fit into unw_context_t");
+  static_assert((check_fit<Registers_ppc, unw_context_t>::does_fit),
+                "ppc registers do not fit into unw_context_t");
   memcpy(&_registers, static_cast<const uint8_t *>(registers),
          sizeof(_registers));
   static_assert(sizeof(ppc_thread_state_t) == 160,
@@ -1023,266 +1028,10 @@ inline const char *Registers_ppc::getRegisterName(int regNum) {
   }
 
 }
-
-/// Registers_riscv holds the register state of a thread in a 64-bit RISC-V
-/// process.
-class _LIBUNWIND_HIDDEN Registers_riscv {
-public:
-  Registers_riscv();
-  Registers_riscv(const void *registers);
-
-  bool        validRegister(int num) const;
-  uint64_t    getRegister(int num) const;
-  void        setRegister(int num, uint64_t value);
-  bool        validFloatRegister(int num) const;
-  double      getFloatRegister(int num) const;
-  void        setFloatRegister(int num, double value);
-  bool        validVectorRegister(int num) const;
-  v128        getVectorRegister(int num) const;
-  void        setVectorRegister(int num, v128 value);
-  const char *getRegisterName(int num);
-  void        jumpto();
-  static int  lastDwarfRegNum() { return 95; }
-
-  uint64_t  getSP() const         { return _registers.__x[2]; }
-  void      setSP(uint64_t value) { _registers.__x[2] = value; }
-  uint64_t  getIP() const         { return _registers.__x[1]; }
-  void      setIP(uint64_t value) { _registers.__x[1] = value; }
-
-private:
-  struct GPRs {
-    uint64_t __x[32]; // x0-x31
-  };
-
-  GPRs    _registers;
-  double  _vectorHalfRegisters[32];
-  // Currently only the lower double in 128-bit vectore registers
-  // is perserved during unwinding.  We could define new register
-  // numbers (> 96) which mean whole vector registers, then this
-  // struct would need to change to contain whole vector registers.
-};
-
-inline Registers_riscv::Registers_riscv(const void *registers) {
-  static_assert(sizeof(Registers_riscv) < sizeof(unw_context_t),
-                    "riscv registers do not fit into unw_context_t");
-  memcpy(&_registers, registers, sizeof(_registers));
-  static_assert(sizeof(GPRs) == 0x100,
-                "expected VFP registers to be at offset 256");
-  memcpy(_vectorHalfRegisters,
-         static_cast<const uint8_t *>(registers) + sizeof(GPRs),
-         sizeof(_vectorHalfRegisters));
-}
-
-inline Registers_riscv::Registers_riscv() {
-  memset(&_registers, 0, sizeof(_registers));
-  memset(&_vectorHalfRegisters, 0, sizeof(_vectorHalfRegisters));
-}
-
-inline bool Registers_riscv::validRegister(int regNum) const {
-  if (regNum == UNW_REG_IP)
-    return true;
-  if (regNum == UNW_REG_SP)
-    return true;
-  if (regNum < 0)
-    return false;
-  if (regNum > 95)
-    return false;
-  if ((regNum > 31) && (regNum < 64))
-    return false;
-  return true;
-}
-
-inline uint64_t Registers_riscv::getRegister(int regNum) const {
-  if (regNum == UNW_REG_IP)
-    return _registers.__x[1];
-  if (regNum == UNW_REG_SP)
-    return _registers.__x[2];
-  if ((regNum >= 0) && (regNum < 32))
-    return _registers.__x[regNum];
-  _LIBUNWIND_ABORT("unsupported riscv register");
-}
-
-inline void Registers_riscv::setRegister(int regNum, uint64_t value) {
-  if (regNum == UNW_REG_IP)
-    _registers.__x[1] = value;
-  else if (regNum == UNW_REG_SP)
-    _registers.__x[2] = value;
-  else if ((regNum >= 0) && (regNum < 32))
-    _registers.__x[regNum] = value;
-  else
-    _LIBUNWIND_ABORT("unsupported riscv register");
-}
-
-inline const char *Registers_riscv::getRegisterName(int regNum) {
-  switch (regNum) {
-  case UNW_REG_IP:
-    return "ra";
-  case UNW_REG_SP:
-    return "sp";
-  case UNW_RISCV_X0:
-    return "x0";
-  case UNW_RISCV_X1:
-    return "ra";
-  case UNW_RISCV_X2:
-    return "sp";
-  case UNW_RISCV_X3:
-    return "x3";
-  case UNW_RISCV_X4:
-    return "x4";
-  case UNW_RISCV_X5:
-    return "x5";
-  case UNW_RISCV_X6:
-    return "x6";
-  case UNW_RISCV_X7:
-    return "x7";
-  case UNW_RISCV_X8:
-    return "x8";
-  case UNW_RISCV_X9:
-    return "x9";
-  case UNW_RISCV_X10:
-    return "x10";
-  case UNW_RISCV_X11:
-    return "x11";
-  case UNW_RISCV_X12:
-    return "x12";
-  case UNW_RISCV_X13:
-    return "x13";
-  case UNW_RISCV_X14:
-    return "x14";
-  case UNW_RISCV_X15:
-    return "x15";
-  case UNW_RISCV_X16:
-    return "x16";
-  case UNW_RISCV_X17:
-    return "x17";
-  case UNW_RISCV_X18:
-    return "x18";
-  case UNW_RISCV_X19:
-    return "x19";
-  case UNW_RISCV_X20:
-    return "x20";
-  case UNW_RISCV_X21:
-    return "x21";
-  case UNW_RISCV_X22:
-    return "x22";
-  case UNW_RISCV_X23:
-    return "x23";
-  case UNW_RISCV_X24:
-    return "x24";
-  case UNW_RISCV_X25:
-    return "x25";
-  case UNW_RISCV_X26:
-    return "x26";
-  case UNW_RISCV_X27:
-    return "x27";
-  case UNW_RISCV_X28:
-    return "x28";
-  case UNW_RISCV_X29:
-    return "x29";
-  case UNW_RISCV_X30:
-    return "x30";
-  case UNW_RISCV_X31:
-    return "x31";
-  case UNW_RISCV_D0:
-    return "d0";
-  case UNW_RISCV_D1:
-    return "d1";
-  case UNW_RISCV_D2:
-    return "d2";
-  case UNW_RISCV_D3:
-    return "d3";
-  case UNW_RISCV_D4:
-    return "d4";
-  case UNW_RISCV_D5:
-    return "d5";
-  case UNW_RISCV_D6:
-    return "d6";
-  case UNW_RISCV_D7:
-    return "d7";
-  case UNW_RISCV_D8:
-    return "d8";
-  case UNW_RISCV_D9:
-    return "d9";
-  case UNW_RISCV_D10:
-    return "d10";
-  case UNW_RISCV_D11:
-    return "d11";
-  case UNW_RISCV_D12:
-    return "d12";
-  case UNW_RISCV_D13:
-    return "d13";
-  case UNW_RISCV_D14:
-    return "d14";
-  case UNW_RISCV_D15:
-    return "d15";
-  case UNW_RISCV_D16:
-    return "d16";
-  case UNW_RISCV_D17:
-    return "d17";
-  case UNW_RISCV_D18:
-    return "d18";
-  case UNW_RISCV_D19:
-    return "d19";
-  case UNW_RISCV_D20:
-    return "d20";
-  case UNW_RISCV_D21:
-    return "d21";
-  case UNW_RISCV_D22:
-    return "d22";
-  case UNW_RISCV_D23:
-    return "d23";
-  case UNW_RISCV_D24:
-    return "d24";
-  case UNW_RISCV_D25:
-    return "d25";
-  case UNW_RISCV_D26:
-    return "d26";
-  case UNW_RISCV_D27:
-    return "d27";
-  case UNW_RISCV_D28:
-    return "d28";
-  case UNW_RISCV_D29:
-    return "d29";
-  case UNW_RISCV_D30:
-    return "d30";
-  case UNW_RISCV_D31:
-    return "d31";
-  default:
-    return "unknown register";
-  }
-}
-
-inline bool Registers_riscv::validFloatRegister(int regNum) const {
-  if (regNum < UNW_RISCV_D0)
-    return false;
-  if (regNum > UNW_RISCV_D31)
-    return false;
-  return true;
-}
-
-inline double Registers_riscv::getFloatRegister(int regNum) const {
-  assert(validFloatRegister(regNum));
-  return _vectorHalfRegisters[regNum - UNW_RISCV_D0];
-}
-
-inline void Registers_riscv::setFloatRegister(int regNum, double value) {
-  assert(validFloatRegister(regNum));
-  _vectorHalfRegisters[regNum - UNW_RISCV_D0] = value;
-}
-
-inline bool Registers_riscv::validVectorRegister(int) const {
-  return false;
-}
-
-inline v128 Registers_riscv::getVectorRegister(int) const {
-  _LIBUNWIND_ABORT("no riscv vector register support yet");
-}
-
-inline void Registers_riscv::setVectorRegister(int, v128) {
-  _LIBUNWIND_ABORT("no riscv vector register support yet");
-}
+#endif // _LIBUNWIND_TARGET_PPC
 
 
+#if defined(_LIBUNWIND_TARGET_AARCH64)
 /// Registers_arm64  holds the register state of a thread in a 64-bit arm
 /// process.
 class _LIBUNWIND_HIDDEN Registers_arm64 {
@@ -1329,8 +1078,8 @@ private:
 };
 
 inline Registers_arm64::Registers_arm64(const void *registers) {
-  static_assert(sizeof(Registers_arm64) < sizeof(unw_context_t),
-                    "arm64 registers do not fit into unw_context_t");
+  static_assert((check_fit<Registers_arm64, unw_context_t>::does_fit),
+                "arm64 registers do not fit into unw_context_t");
   memcpy(&_registers, registers, sizeof(_registers));
   static_assert(sizeof(GPRs) == 0x110,
                 "expected VFP registers to be at offset 272");
@@ -1547,7 +1296,9 @@ inline v128 Registers_arm64::getVectorRegister(int) const {
 inline void Registers_arm64::setVectorRegister(int, v128) {
   _LIBUNWIND_ABORT("no arm64 vector register support yet");
 }
+#endif // _LIBUNWIND_TARGET_AARCH64
 
+#if defined(_LIBUNWIND_TARGET_ARM)
 /// Registers_arm holds the register state of a thread in a 32-bit arm
 /// process.
 ///
@@ -1653,8 +1404,8 @@ inline Registers_arm::Registers_arm(const void *registers)
     _saved_vfp_d16_d31(false),
     _saved_iwmmx(false),
     _saved_iwmmx_control(false) {
-  static_assert(sizeof(Registers_arm) < sizeof(unw_context_t),
-                    "arm registers do not fit into unw_context_t");
+  static_assert((check_fit<Registers_arm, unw_context_t>::does_fit),
+                "arm registers do not fit into unw_context_t");
   // See unw_getcontext() note about data.
   memcpy(&_registers, registers, sizeof(_registers));
   memset(&_vfp_d0_d15_pad, 0, sizeof(_vfp_d0_d15_pad));
@@ -1969,6 +1720,10 @@ inline v128 Registers_arm::getVectorRegister(int) const {
 inline void Registers_arm::setVectorRegister(int, v128) {
   _LIBUNWIND_ABORT("ARM vector support not implemented");
 }
+#endif // _LIBUNWIND_TARGET_ARM
+
+
+#if defined(_LIBUNWIND_TARGET_OR1K)
 /// Registers_or1k holds the register state of a thread in an OpenRISC1000
 /// process.
 class _LIBUNWIND_HIDDEN Registers_or1k {
@@ -2003,8 +1758,8 @@ private:
 };
 
 inline Registers_or1k::Registers_or1k(const void *registers) {
-  static_assert(sizeof(Registers_or1k) < sizeof(unw_context_t),
-                    "or1k registers do not fit into unw_context_t");
+  static_assert((check_fit<Registers_or1k, unw_context_t>::does_fit),
+                "or1k registers do not fit into unw_context_t");
   memcpy(&_registers, static_cast<const uint8_t *>(registers),
          sizeof(_registers));
 }
@@ -2151,6 +1906,268 @@ inline const char *Registers_or1k::getRegisterName(int regNum) {
   }
 
 }
+#endif // _LIBUNWIND_TARGET_OR1K
+
+
+#if defined(_LIBUNWIND_TARGET_RISCV)
+/// Registers_riscv holds the register state of a thread in a 64-bit RISC-V
+/// process.
+class _LIBUNWIND_HIDDEN Registers_riscv {
+public:
+  Registers_riscv();
+  Registers_riscv(const void *registers);
+
+  bool        validRegister(int num) const;
+  uint64_t    getRegister(int num) const;
+  void        setRegister(int num, uint64_t value);
+  bool        validFloatRegister(int num) const;
+  double      getFloatRegister(int num) const;
+  void        setFloatRegister(int num, double value);
+  bool        validVectorRegister(int num) const;
+  v128        getVectorRegister(int num) const;
+  void        setVectorRegister(int num, v128 value);
+  const char *getRegisterName(int num);
+  void        jumpto();
+  static int  lastDwarfRegNum() { return 95; }
+
+  uint64_t  getSP() const         { return _registers.__x[2]; }
+  void      setSP(uint64_t value) { _registers.__x[2] = value; }
+  uint64_t  getIP() const         { return _registers.__x[1]; }
+  void      setIP(uint64_t value) { _registers.__x[1] = value; }
+
+private:
+  struct GPRs {
+    uint64_t __x[32]; // x0-x31
+  };
+
+  GPRs    _registers;
+  double  _vectorHalfRegisters[32];
+  // Currently only the lower double in 128-bit vectore registers
+  // is perserved during unwinding.  We could define new register
+  // numbers (> 96) which mean whole vector registers, then this
+  // struct would need to change to contain whole vector registers.
+};
+
+inline Registers_riscv::Registers_riscv(const void *registers) {
+  static_assert((check_fit<Registers_riscv, unw_context_t>::does_fit),
+                "riscv registers do not fit into unw_context_t");
+  memcpy(&_registers, registers, sizeof(_registers));
+  static_assert(sizeof(GPRs) == 0x100,
+                "expected VFP registers to be at offset 256");
+  memcpy(_vectorHalfRegisters,
+         static_cast<const uint8_t *>(registers) + sizeof(GPRs),
+         sizeof(_vectorHalfRegisters));
+}
+
+inline Registers_riscv::Registers_riscv() {
+  memset(&_registers, 0, sizeof(_registers));
+  memset(&_vectorHalfRegisters, 0, sizeof(_vectorHalfRegisters));
+}
+
+inline bool Registers_riscv::validRegister(int regNum) const {
+  if (regNum == UNW_REG_IP)
+    return true;
+  if (regNum == UNW_REG_SP)
+    return true;
+  if (regNum < 0)
+    return false;
+  if (regNum > 95)
+    return false;
+  if ((regNum > 31) && (regNum < 64))
+    return false;
+  return true;
+}
+
+inline uint64_t Registers_riscv::getRegister(int regNum) const {
+  if (regNum == UNW_REG_IP)
+    return _registers.__x[1];
+  if (regNum == UNW_REG_SP)
+    return _registers.__x[2];
+  if ((regNum >= 0) && (regNum < 32))
+    return _registers.__x[regNum];
+  _LIBUNWIND_ABORT("unsupported riscv register");
+}
+
+inline void Registers_riscv::setRegister(int regNum, uint64_t value) {
+  if (regNum == UNW_REG_IP)
+    _registers.__x[1] = value;
+  else if (regNum == UNW_REG_SP)
+    _registers.__x[2] = value;
+  else if ((regNum >= 0) && (regNum < 32))
+    _registers.__x[regNum] = value;
+  else
+    _LIBUNWIND_ABORT("unsupported riscv register");
+}
+
+inline const char *Registers_riscv::getRegisterName(int regNum) {
+  switch (regNum) {
+  case UNW_REG_IP:
+    return "ra";
+  case UNW_REG_SP:
+    return "sp";
+  case UNW_RISCV_X0:
+    return "x0";
+  case UNW_RISCV_X1:
+    return "ra";
+  case UNW_RISCV_X2:
+    return "sp";
+  case UNW_RISCV_X3:
+    return "x3";
+  case UNW_RISCV_X4:
+    return "x4";
+  case UNW_RISCV_X5:
+    return "x5";
+  case UNW_RISCV_X6:
+    return "x6";
+  case UNW_RISCV_X7:
+    return "x7";
+  case UNW_RISCV_X8:
+    return "x8";
+  case UNW_RISCV_X9:
+    return "x9";
+  case UNW_RISCV_X10:
+    return "x10";
+  case UNW_RISCV_X11:
+    return "x11";
+  case UNW_RISCV_X12:
+    return "x12";
+  case UNW_RISCV_X13:
+    return "x13";
+  case UNW_RISCV_X14:
+    return "x14";
+  case UNW_RISCV_X15:
+    return "x15";
+  case UNW_RISCV_X16:
+    return "x16";
+  case UNW_RISCV_X17:
+    return "x17";
+  case UNW_RISCV_X18:
+    return "x18";
+  case UNW_RISCV_X19:
+    return "x19";
+  case UNW_RISCV_X20:
+    return "x20";
+  case UNW_RISCV_X21:
+    return "x21";
+  case UNW_RISCV_X22:
+    return "x22";
+  case UNW_RISCV_X23:
+    return "x23";
+  case UNW_RISCV_X24:
+    return "x24";
+  case UNW_RISCV_X25:
+    return "x25";
+  case UNW_RISCV_X26:
+    return "x26";
+  case UNW_RISCV_X27:
+    return "x27";
+  case UNW_RISCV_X28:
+    return "x28";
+  case UNW_RISCV_X29:
+    return "x29";
+  case UNW_RISCV_X30:
+    return "x30";
+  case UNW_RISCV_X31:
+    return "x31";
+  case UNW_RISCV_D0:
+    return "d0";
+  case UNW_RISCV_D1:
+    return "d1";
+  case UNW_RISCV_D2:
+    return "d2";
+  case UNW_RISCV_D3:
+    return "d3";
+  case UNW_RISCV_D4:
+    return "d4";
+  case UNW_RISCV_D5:
+    return "d5";
+  case UNW_RISCV_D6:
+    return "d6";
+  case UNW_RISCV_D7:
+    return "d7";
+  case UNW_RISCV_D8:
+    return "d8";
+  case UNW_RISCV_D9:
+    return "d9";
+  case UNW_RISCV_D10:
+    return "d10";
+  case UNW_RISCV_D11:
+    return "d11";
+  case UNW_RISCV_D12:
+    return "d12";
+  case UNW_RISCV_D13:
+    return "d13";
+  case UNW_RISCV_D14:
+    return "d14";
+  case UNW_RISCV_D15:
+    return "d15";
+  case UNW_RISCV_D16:
+    return "d16";
+  case UNW_RISCV_D17:
+    return "d17";
+  case UNW_RISCV_D18:
+    return "d18";
+  case UNW_RISCV_D19:
+    return "d19";
+  case UNW_RISCV_D20:
+    return "d20";
+  case UNW_RISCV_D21:
+    return "d21";
+  case UNW_RISCV_D22:
+    return "d22";
+  case UNW_RISCV_D23:
+    return "d23";
+  case UNW_RISCV_D24:
+    return "d24";
+  case UNW_RISCV_D25:
+    return "d25";
+  case UNW_RISCV_D26:
+    return "d26";
+  case UNW_RISCV_D27:
+    return "d27";
+  case UNW_RISCV_D28:
+    return "d28";
+  case UNW_RISCV_D29:
+    return "d29";
+  case UNW_RISCV_D30:
+    return "d30";
+  case UNW_RISCV_D31:
+    return "d31";
+  default:
+    return "unknown register";
+  }
+}
+
+inline bool Registers_riscv::validFloatRegister(int regNum) const {
+  if (regNum < UNW_RISCV_D0)
+    return false;
+  if (regNum > UNW_RISCV_D31)
+    return false;
+  return true;
+}
+
+inline double Registers_riscv::getFloatRegister(int regNum) const {
+  assert(validFloatRegister(regNum));
+  return _vectorHalfRegisters[regNum - UNW_RISCV_D0];
+}
+
+inline void Registers_riscv::setFloatRegister(int regNum, double value) {
+  assert(validFloatRegister(regNum));
+  _vectorHalfRegisters[regNum - UNW_RISCV_D0] = value;
+}
+
+inline bool Registers_riscv::validVectorRegister(int) const {
+  return false;
+}
+
+inline v128 Registers_riscv::getVectorRegister(int) const {
+  _LIBUNWIND_ABORT("no riscv vector register support yet");
+}
+
+inline void Registers_riscv::setVectorRegister(int, v128) {
+  _LIBUNWIND_ABORT("no riscv vector register support yet");
+}
+#endif // _LIBUNWIND_TARGET_RISCV
 } // namespace libunwind
 
 #endif // __REGISTERS_HPP__
diff --git a/contrib/llvm/projects/libunwind/src/Unwind-EHABI.cpp b/contrib/llvm/projects/libunwind/src/Unwind-EHABI.cpp
index bc3df41..5950c69 100644
--- a/contrib/llvm/projects/libunwind/src/Unwind-EHABI.cpp
+++ b/contrib/llvm/projects/libunwind/src/Unwind-EHABI.cpp
@@ -438,39 +438,21 @@ extern "C" _Unwind_Reason_Code __aeabi_unwind_cpp_pr2(
 }
 
 static _Unwind_Reason_Code
-unwind_phase1(unw_context_t *uc, _Unwind_Exception *exception_object) {
+unwind_phase1(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *exception_object) {
   // EHABI #7.3 discusses preserving the VRS in a "temporary VRS" during
   // phase 1 and then restoring it to the "primary VRS" for phase 2. The
   // effect is phase 2 doesn't see any of the VRS manipulations from phase 1.
   // In this implementation, the phases don't share the VRS backing store.
   // Instead, they are passed the original |uc| and they create a new VRS
   // from scratch thus achieving the same effect.
-  unw_cursor_t cursor1;
-  unw_init_local(&cursor1, uc);
+  unw_init_local(cursor, uc);
 
   // Walk each frame looking for a place to stop.
   for (bool handlerNotFound = true; handlerNotFound;) {
 
-#if !_LIBUNWIND_ARM_EHABI
-    // Ask libuwind to get next frame (skip over first which is
-    // _Unwind_RaiseException).
-    int stepResult = unw_step(&cursor1);
-    if (stepResult == 0) {
-      _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_step() reached "
-                                 "bottom => _URC_END_OF_STACK\n",
-                                 static_cast<void *>(exception_object));
-      return _URC_END_OF_STACK;
-    } else if (stepResult < 0) {
-      _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_step failed => "
-                                 "_URC_FATAL_PHASE1_ERROR\n",
-                                 static_cast<void *>(exception_object));
-      return _URC_FATAL_PHASE1_ERROR;
-    }
-#endif
-
     // See if frame has code to run (has personality routine).
     unw_proc_info_t frameInfo;
-    if (unw_get_proc_info(&cursor1, &frameInfo) != UNW_ESUCCESS) {
+    if (unw_get_proc_info(cursor, &frameInfo) != UNW_ESUCCESS) {
       _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_get_proc_info "
                                  "failed => _URC_FATAL_PHASE1_ERROR\n",
                                  static_cast<void *>(exception_object));
@@ -482,12 +464,12 @@ unwind_phase1(unw_context_t *uc, _Unwind_Exception *exception_object) {
       char functionBuf[512];
       const char *functionName = functionBuf;
       unw_word_t offset;
-      if ((unw_get_proc_name(&cursor1, functionBuf, sizeof(functionBuf),
+      if ((unw_get_proc_name(cursor, functionBuf, sizeof(functionBuf),
                              &offset) != UNW_ESUCCESS) ||
           (frameInfo.start_ip + offset > frameInfo.end_ip))
         functionName = ".anonymous.";
       unw_word_t pc;
-      unw_get_reg(&cursor1, UNW_REG_IP, &pc);
+      unw_get_reg(cursor, UNW_REG_IP, &pc);
       _LIBUNWIND_TRACE_UNWINDING(
           "unwind_phase1(ex_ojb=%p): pc=0x%llX, start_ip=0x%llX, func=%s, "
           "lsda=0x%llX, personality=0x%llX\n",
@@ -505,7 +487,7 @@ unwind_phase1(unw_context_t *uc, _Unwind_Exception *exception_object) {
           "unwind_phase1(ex_ojb=%p): calling personality function %p\n",
           static_cast<void *>(exception_object),
           reinterpret_cast<void *>(reinterpret_cast<uintptr_t>(p)));
-      struct _Unwind_Context *context = (struct _Unwind_Context *)(&cursor1);
+      struct _Unwind_Context *context = (struct _Unwind_Context *)(cursor);
       exception_object->pr_cache.fnstart = frameInfo.start_ip;
       exception_object->pr_cache.ehtp =
           (_Unwind_EHT_Header *)frameInfo.unwind_info;
@@ -553,12 +535,11 @@ unwind_phase1(unw_context_t *uc, _Unwind_Exception *exception_object) {
   return _URC_NO_REASON;
 }
 
-static _Unwind_Reason_Code unwind_phase2(unw_context_t *uc,
+static _Unwind_Reason_Code unwind_phase2(unw_context_t *uc, unw_cursor_t *cursor,
                                          _Unwind_Exception *exception_object,
                                          bool resume) {
   // See comment at the start of unwind_phase1 regarding VRS integrity.
-  unw_cursor_t cursor2;
-  unw_init_local(&cursor2, uc);
+  unw_init_local(cursor, uc);
 
   _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p)\n",
                              static_cast<void *>(exception_object));
@@ -580,31 +561,16 @@ static _Unwind_Reason_Code unwind_phase2(unw_context_t *uc,
       // for. After this, continue unwinding as if normal.
       //
       // See #7.4.6 for details.
-      unw_set_reg(&cursor2, UNW_REG_IP,
+      unw_set_reg(cursor, UNW_REG_IP,
                   exception_object->unwinder_cache.reserved2);
       resume = false;
     }
 
-#if !_LIBUNWIND_ARM_EHABI
-    int stepResult = unw_step(&cursor2);
-    if (stepResult == 0) {
-      _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step() reached "
-                                 "bottom => _URC_END_OF_STACK\n",
-                                 static_cast<void *>(exception_object));
-      return _URC_END_OF_STACK;
-    } else if (stepResult < 0) {
-      _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step failed => "
-                                 "_URC_FATAL_PHASE1_ERROR\n",
-                                 static_cast<void *>(exception_object));
-      return _URC_FATAL_PHASE2_ERROR;
-    }
-#endif
-
     // Get info about this frame.
     unw_word_t sp;
     unw_proc_info_t frameInfo;
-    unw_get_reg(&cursor2, UNW_REG_SP, &sp);
-    if (unw_get_proc_info(&cursor2, &frameInfo) != UNW_ESUCCESS) {
+    unw_get_reg(cursor, UNW_REG_SP, &sp);
+    if (unw_get_proc_info(cursor, &frameInfo) != UNW_ESUCCESS) {
       _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_get_proc_info "
                                  "failed => _URC_FATAL_PHASE1_ERROR\n",
                                  static_cast<void *>(exception_object));
@@ -616,7 +582,7 @@ static _Unwind_Reason_Code unwind_phase2(unw_context_t *uc,
       char functionBuf[512];
       const char *functionName = functionBuf;
       unw_word_t offset;
-      if ((unw_get_proc_name(&cursor2, functionBuf, sizeof(functionBuf),
+      if ((unw_get_proc_name(cursor, functionBuf, sizeof(functionBuf),
                              &offset) != UNW_ESUCCESS) ||
           (frameInfo.start_ip + offset > frameInfo.end_ip))
         functionName = ".anonymous.";
@@ -632,7 +598,7 @@ static _Unwind_Reason_Code unwind_phase2(unw_context_t *uc,
     if (frameInfo.handler != 0) {
       __personality_routine p =
           (__personality_routine)(long)(frameInfo.handler);
-      struct _Unwind_Context *context = (struct _Unwind_Context *)(&cursor2);
+      struct _Unwind_Context *context = (struct _Unwind_Context *)(cursor);
       // EHABI #7.2
       exception_object->pr_cache.fnstart = frameInfo.start_ip;
       exception_object->pr_cache.ehtp =
@@ -661,8 +627,8 @@ static _Unwind_Reason_Code unwind_phase2(unw_context_t *uc,
         // We may get control back if landing pad calls _Unwind_Resume().
         if (_LIBUNWIND_TRACING_UNWINDING) {
           unw_word_t pc;
-          unw_get_reg(&cursor2, UNW_REG_IP, &pc);
-          unw_get_reg(&cursor2, UNW_REG_SP, &sp);
+          unw_get_reg(cursor, UNW_REG_IP, &pc);
+          unw_get_reg(cursor, UNW_REG_SP, &sp);
           _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): re-entering "
                                      "user code with ip=0x%llX, sp=0x%llX\n",
                                      static_cast<void *>(exception_object),
@@ -673,10 +639,10 @@ static _Unwind_Reason_Code unwind_phase2(unw_context_t *uc,
           // EHABI #7.4.1 says we need to preserve pc for when _Unwind_Resume
           // is called back, to find this same frame.
           unw_word_t pc;
-          unw_get_reg(&cursor2, UNW_REG_IP, &pc);
+          unw_get_reg(cursor, UNW_REG_IP, &pc);
           exception_object->unwinder_cache.reserved2 = (uint32_t)pc;
         }
-        unw_resume(&cursor2);
+        unw_resume(cursor);
         // unw_resume() only returns if there was an error.
         return _URC_FATAL_PHASE2_ERROR;
 
@@ -705,6 +671,7 @@ _Unwind_RaiseException(_Unwind_Exception *exception_object) {
   _LIBUNWIND_TRACE_API("_Unwind_RaiseException(ex_obj=%p)\n",
                        static_cast<void *>(exception_object));
   unw_context_t uc;
+  unw_cursor_t cursor;
   unw_getcontext(&uc);
 
   // This field for is for compatibility with GCC to say this isn't a forced
@@ -712,12 +679,12 @@ _Unwind_RaiseException(_Unwind_Exception *exception_object) {
   exception_object->unwinder_cache.reserved1 = 0;
 
   // phase 1: the search phase
-  _Unwind_Reason_Code phase1 = unwind_phase1(&uc, exception_object);
+  _Unwind_Reason_Code phase1 = unwind_phase1(&uc, &cursor, exception_object);
   if (phase1 != _URC_NO_REASON)
     return phase1;
 
   // phase 2: the clean up phase
-  return unwind_phase2(&uc, exception_object, false);
+  return unwind_phase2(&uc, &cursor, exception_object, false);
 }
 
 _LIBUNWIND_EXPORT void _Unwind_Complete(_Unwind_Exception* exception_object) {
@@ -742,12 +709,13 @@ _Unwind_Resume(_Unwind_Exception *exception_object) {
   _LIBUNWIND_TRACE_API("_Unwind_Resume(ex_obj=%p)\n",
                        static_cast<void *>(exception_object));
   unw_context_t uc;
+  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, exception_object, true);
+  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");
diff --git a/contrib/llvm/projects/libunwind/src/UnwindCursor.hpp b/contrib/llvm/projects/libunwind/src/UnwindCursor.hpp
index 166e2fd..7c217e1 100644
--- a/contrib/llvm/projects/libunwind/src/UnwindCursor.hpp
+++ b/contrib/llvm/projects/libunwind/src/UnwindCursor.hpp
@@ -481,30 +481,39 @@ private:
     return stepWithCompactEncoding(dummy);
   }
 
+#if defined(_LIBUNWIND_TARGET_X86_64)
   int stepWithCompactEncoding(Registers_x86_64 &) {
     return CompactUnwinder_x86_64<A>::stepWithCompactEncoding(
         _info.format, _info.start_ip, _addressSpace, _registers);
   }
+#endif
 
+#if defined(_LIBUNWIND_TARGET_I386)
   int stepWithCompactEncoding(Registers_x86 &) {
     return CompactUnwinder_x86<A>::stepWithCompactEncoding(
         _info.format, (uint32_t)_info.start_ip, _addressSpace, _registers);
   }
+#endif
 
+#if defined(_LIBUNWIND_TARGET_PPC)
   int stepWithCompactEncoding(Registers_ppc &) {
     return UNW_EINVAL;
   }
+#endif
 
+#if defined(_LIBUNWIND_TARGET_AARCH64)
   int stepWithCompactEncoding(Registers_arm64 &) {
     return CompactUnwinder_arm64<A>::stepWithCompactEncoding(
         _info.format, _info.start_ip, _addressSpace, _registers);
   }
+#endif
 
   bool compactSaysUseDwarf(uint32_t *offset=NULL) const {
     R dummy;
     return compactSaysUseDwarf(dummy, offset);
   }
 
+#if defined(_LIBUNWIND_TARGET_X86_64)
   bool compactSaysUseDwarf(Registers_x86_64 &, uint32_t *offset) const {
     if ((_info.format & UNWIND_X86_64_MODE_MASK) == UNWIND_X86_64_MODE_DWARF) {
       if (offset)
@@ -513,7 +522,9 @@ private:
     }
     return false;
   }
+#endif
 
+#if defined(_LIBUNWIND_TARGET_I386)
   bool compactSaysUseDwarf(Registers_x86 &, uint32_t *offset) const {
     if ((_info.format & UNWIND_X86_MODE_MASK) == UNWIND_X86_MODE_DWARF) {
       if (offset)
@@ -522,11 +533,15 @@ private:
     }
     return false;
   }
+#endif
 
+#if defined(_LIBUNWIND_TARGET_PPC)
   bool compactSaysUseDwarf(Registers_ppc &, uint32_t *) const {
     return true;
   }
+#endif
 
+#if defined(_LIBUNWIND_TARGET_AARCH64)
   bool compactSaysUseDwarf(Registers_arm64 &, uint32_t *offset) const {
     if ((_info.format & UNWIND_ARM64_MODE_MASK) == UNWIND_ARM64_MODE_DWARF) {
       if (offset)
@@ -535,6 +550,7 @@ private:
     }
     return false;
   }
+#endif
 #endif // _LIBUNWIND_SUPPORT_COMPACT_UNWIND
 
 #if _LIBUNWIND_SUPPORT_DWARF_UNWIND
@@ -543,29 +559,41 @@ private:
     return dwarfEncoding(dummy);
   }
 
+#if defined(_LIBUNWIND_TARGET_X86_64)
   compact_unwind_encoding_t dwarfEncoding(Registers_x86_64 &) const {
     return UNWIND_X86_64_MODE_DWARF;
   }
+#endif
 
+#if defined(_LIBUNWIND_TARGET_I386)
   compact_unwind_encoding_t dwarfEncoding(Registers_x86 &) const {
     return UNWIND_X86_MODE_DWARF;
   }
+#endif
 
+#if defined(_LIBUNWIND_TARGET_PPC)
   compact_unwind_encoding_t dwarfEncoding(Registers_ppc &) const {
     return 0;
   }
+#endif
 
+#if defined(_LIBUNWIND_TARGET_AARCH64)
   compact_unwind_encoding_t dwarfEncoding(Registers_arm64 &) const {
     return UNWIND_ARM64_MODE_DWARF;
   }
+#endif
 
+#if defined (_LIBUNWIND_TARGET_OR1K)
   compact_unwind_encoding_t dwarfEncoding(Registers_or1k &) const {
     return 0;
   }
+#endif
 
+#if defined (_LIBUNWIND_TARGET_RISCV)
   compact_unwind_encoding_t dwarfEncoding(Registers_riscv &) const {
     return 0;
   }
+#endif
 #endif // _LIBUNWIND_SUPPORT_DWARF_UNWIND
 
 
@@ -581,7 +609,7 @@ template <typename A, typename R>
 UnwindCursor<A, R>::UnwindCursor(unw_context_t *context, A &as)
     : _addressSpace(as), _registers(context), _unwindInfoMissing(false),
       _isSignalFrame(false) {
-  static_assert(sizeof(UnwindCursor<A, R>) < sizeof(unw_cursor_t),
+  static_assert((check_fit<UnwindCursor<A, R>, unw_cursor_t>::does_fit),
                 "UnwindCursor<> does not fit in unw_cursor_t");
   memset(&_info, 0, sizeof(_info));
 }
diff --git a/contrib/llvm/projects/libunwind/src/UnwindLevel1.c b/contrib/llvm/projects/libunwind/src/UnwindLevel1.c
index ce6eb28..7294f25 100644
--- a/contrib/llvm/projects/libunwind/src/UnwindLevel1.c
+++ b/contrib/llvm/projects/libunwind/src/UnwindLevel1.c
@@ -33,16 +33,15 @@
 #if !_LIBUNWIND_ARM_EHABI
 
 static _Unwind_Reason_Code
-unwind_phase1(unw_context_t *uc, _Unwind_Exception *exception_object) {
-  unw_cursor_t cursor1;
-  unw_init_local(&cursor1, uc);
+unwind_phase1(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *exception_object) {
+  unw_init_local(cursor, uc);
 
   // Walk each frame looking for a place to stop.
   bool handlerNotFound = true;
   while (handlerNotFound) {
     // Ask libuwind to get next frame (skip over first which is
     // _Unwind_RaiseException).
-    int stepResult = unw_step(&cursor1);
+    int stepResult = unw_step(cursor);
     if (stepResult == 0) {
       _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_step() reached "
                                  "bottom => _URC_END_OF_STACK\n",
@@ -58,7 +57,7 @@ unwind_phase1(unw_context_t *uc, _Unwind_Exception *exception_object) {
     // See if frame has code to run (has personality routine).
     unw_proc_info_t frameInfo;
     unw_word_t sp;
-    if (unw_get_proc_info(&cursor1, &frameInfo) != UNW_ESUCCESS) {
+    if (unw_get_proc_info(cursor, &frameInfo) != UNW_ESUCCESS) {
       _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_get_proc_info "
                                  "failed => _URC_FATAL_PHASE1_ERROR\n",
                                  (void *)exception_object);
@@ -70,12 +69,12 @@ unwind_phase1(unw_context_t *uc, _Unwind_Exception *exception_object) {
       char functionBuf[512];
       const char *functionName = functionBuf;
       unw_word_t offset;
-      if ((unw_get_proc_name(&cursor1, functionBuf, sizeof(functionBuf),
+      if ((unw_get_proc_name(cursor, functionBuf, sizeof(functionBuf),
                              &offset) != UNW_ESUCCESS) ||
           (frameInfo.start_ip + offset > frameInfo.end_ip))
         functionName = ".anonymous.";
       unw_word_t pc;
-      unw_get_reg(&cursor1, UNW_REG_IP, &pc);
+      unw_get_reg(cursor, UNW_REG_IP, &pc);
       _LIBUNWIND_TRACE_UNWINDING(
           "unwind_phase1(ex_ojb=%p): pc=0x%" PRIx64 ", start_ip=0x%" PRIx64
           ", func=%s, lsda=0x%" PRIx64 ", personality=0x%" PRIx64 "\n",
@@ -93,13 +92,13 @@ unwind_phase1(unw_context_t *uc, _Unwind_Exception *exception_object) {
           (void *)exception_object, (void *)(uintptr_t)p);
       _Unwind_Reason_Code personalityResult =
           (*p)(1, _UA_SEARCH_PHASE, exception_object->exception_class,
-               exception_object, (struct _Unwind_Context *)(&cursor1));
+               exception_object, (struct _Unwind_Context *)(cursor));
       switch (personalityResult) {
       case _URC_HANDLER_FOUND:
         // found a catch clause or locals that need destructing in this frame
         // stop search and remember stack pointer at the frame
         handlerNotFound = false;
-        unw_get_reg(&cursor1, UNW_REG_SP, &sp);
+        unw_get_reg(cursor, UNW_REG_SP, &sp);
         exception_object->private_2 = (uintptr_t)sp;
         _LIBUNWIND_TRACE_UNWINDING(
             "unwind_phase1(ex_ojb=%p): _URC_HANDLER_FOUND \n",
@@ -127,9 +126,8 @@ unwind_phase1(unw_context_t *uc, _Unwind_Exception *exception_object) {
 
 
 static _Unwind_Reason_Code
-unwind_phase2(unw_context_t *uc, _Unwind_Exception *exception_object) {
-  unw_cursor_t cursor2;
-  unw_init_local(&cursor2, uc);
+unwind_phase2(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *exception_object) {
+  unw_init_local(cursor, uc);
 
   _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p)\n",
                              (void *)exception_object);
@@ -139,7 +137,7 @@ unwind_phase2(unw_context_t *uc, _Unwind_Exception *exception_object) {
 
     // Ask libuwind to get next frame (skip over first which is
     // _Unwind_RaiseException).
-    int stepResult = unw_step(&cursor2);
+    int stepResult = unw_step(cursor);
     if (stepResult == 0) {
       _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step() reached "
                                  "bottom => _URC_END_OF_STACK\n",
@@ -155,8 +153,8 @@ unwind_phase2(unw_context_t *uc, _Unwind_Exception *exception_object) {
     // Get info about this frame.
     unw_word_t sp;
     unw_proc_info_t frameInfo;
-    unw_get_reg(&cursor2, UNW_REG_SP, &sp);
-    if (unw_get_proc_info(&cursor2, &frameInfo) != UNW_ESUCCESS) {
+    unw_get_reg(cursor, UNW_REG_SP, &sp);
+    if (unw_get_proc_info(cursor, &frameInfo) != UNW_ESUCCESS) {
       _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_get_proc_info "
                                  "failed => _URC_FATAL_PHASE1_ERROR\n",
                                  (void *)exception_object);
@@ -168,7 +166,7 @@ unwind_phase2(unw_context_t *uc, _Unwind_Exception *exception_object) {
       char functionBuf[512];
       const char *functionName = functionBuf;
       unw_word_t offset;
-      if ((unw_get_proc_name(&cursor2, functionBuf, sizeof(functionBuf),
+      if ((unw_get_proc_name(cursor, functionBuf, sizeof(functionBuf),
                              &offset) != UNW_ESUCCESS) ||
           (frameInfo.start_ip + offset > frameInfo.end_ip))
         functionName = ".anonymous.";
@@ -191,7 +189,7 @@ unwind_phase2(unw_context_t *uc, _Unwind_Exception *exception_object) {
       }
        _Unwind_Reason_Code personalityResult =
           (*p)(1, action, exception_object->exception_class, exception_object,
-               (struct _Unwind_Context *)(&cursor2));
+               (struct _Unwind_Context *)(cursor));
       switch (personalityResult) {
       case _URC_CONTINUE_UNWIND:
         // Continue unwinding
@@ -212,14 +210,14 @@ unwind_phase2(unw_context_t *uc, _Unwind_Exception *exception_object) {
         // We may get control back if landing pad calls _Unwind_Resume().
         if (_LIBUNWIND_TRACING_UNWINDING) {
           unw_word_t pc;
-          unw_get_reg(&cursor2, UNW_REG_IP, &pc);
-          unw_get_reg(&cursor2, UNW_REG_SP, &sp);
+          unw_get_reg(cursor, UNW_REG_IP, &pc);
+          unw_get_reg(cursor, UNW_REG_SP, &sp);
           _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): re-entering "
                                      "user code with ip=0x%" PRIx64
                                      ", sp=0x%" PRIx64 "\n",
                                      (void *)exception_object, pc, sp);
         }
-        unw_resume(&cursor2);
+        unw_resume(cursor);
         // unw_resume() only returns if there was an error.
         return _URC_FATAL_PHASE2_ERROR;
       default:
@@ -237,18 +235,17 @@ unwind_phase2(unw_context_t *uc, _Unwind_Exception *exception_object) {
 }
 
 static _Unwind_Reason_Code
-unwind_phase2_forced(unw_context_t *uc,
+unwind_phase2_forced(unw_context_t *uc, unw_cursor_t *cursor,
                      _Unwind_Exception *exception_object,
                      _Unwind_Stop_Fn stop, void *stop_parameter) {
-  unw_cursor_t cursor2;
-  unw_init_local(&cursor2, uc);
+  unw_init_local(cursor, uc);
 
   // Walk each frame until we reach where search phase said to stop
-  while (unw_step(&cursor2) > 0) {
+  while (unw_step(cursor) > 0) {
 
     // Update info about this frame.
     unw_proc_info_t frameInfo;
-    if (unw_get_proc_info(&cursor2, &frameInfo) != UNW_ESUCCESS) {
+    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\n",
                                  (void *)exception_object);
@@ -260,7 +257,7 @@ unwind_phase2_forced(unw_context_t *uc,
       char functionBuf[512];
       const char *functionName = functionBuf;
       unw_word_t offset;
-      if ((unw_get_proc_name(&cursor2, functionBuf, sizeof(functionBuf),
+      if ((unw_get_proc_name(cursor, functionBuf, sizeof(functionBuf),
                              &offset) != UNW_ESUCCESS) ||
           (frameInfo.start_ip + offset > frameInfo.end_ip))
         functionName = ".anonymous.";
@@ -276,7 +273,7 @@ unwind_phase2_forced(unw_context_t *uc,
         (_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE);
     _Unwind_Reason_Code stopResult =
         (*stop)(1, action, exception_object->exception_class, exception_object,
-                (struct _Unwind_Context *)(&cursor2), stop_parameter);
+                (struct _Unwind_Context *)(cursor), stop_parameter);
     _LIBUNWIND_TRACE_UNWINDING(
         "unwind_phase2_forced(ex_ojb=%p): stop function returned %d\n",
         (void *)exception_object, stopResult);
@@ -296,7 +293,7 @@ unwind_phase2_forced(unw_context_t *uc,
           (void *)exception_object, (void *)(uintptr_t)p);
       _Unwind_Reason_Code personalityResult =
           (*p)(1, action, exception_object->exception_class, exception_object,
-               (struct _Unwind_Context *)(&cursor2));
+               (struct _Unwind_Context *)(cursor));
       switch (personalityResult) {
       case _URC_CONTINUE_UNWIND:
         _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
@@ -311,7 +308,7 @@ unwind_phase2_forced(unw_context_t *uc,
                                    "_URC_INSTALL_CONTEXT\n",
                                    (void *)exception_object);
         // We may get control back if landing pad calls _Unwind_Resume().
-        unw_resume(&cursor2);
+        unw_resume(cursor);
         break;
       default:
         // Personality routine returned an unknown result code.
@@ -332,7 +329,7 @@ unwind_phase2_forced(unw_context_t *uc,
   _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 *)(&cursor2), stop_parameter);
+          (struct _Unwind_Context *)(cursor), stop_parameter);
 
   // Clean up phase did not resume at the frame that the search phase said it
   // would.
@@ -346,6 +343,7 @@ _Unwind_RaiseException(_Unwind_Exception *exception_object) {
   _LIBUNWIND_TRACE_API("_Unwind_RaiseException(ex_obj=%p)\n",
                        (void *)exception_object);
   unw_context_t uc;
+  unw_cursor_t cursor;
   unw_getcontext(&uc);
 
   // Mark that this is a non-forced unwind, so _Unwind_Resume()
@@ -354,12 +352,12 @@ _Unwind_RaiseException(_Unwind_Exception *exception_object) {
   exception_object->private_2 = 0;
 
   // phase 1: the search phase
-  _Unwind_Reason_Code phase1 = unwind_phase1(&uc, exception_object);
+  _Unwind_Reason_Code phase1 = unwind_phase1(&uc, &cursor, exception_object);
   if (phase1 != _URC_NO_REASON)
     return phase1;
 
   // phase 2: the clean up phase
-  return unwind_phase2(&uc, exception_object);
+  return unwind_phase2(&uc, &cursor, exception_object);
 }
 
 
@@ -379,14 +377,15 @@ _LIBUNWIND_EXPORT void
 _Unwind_Resume(_Unwind_Exception *exception_object) {
   _LIBUNWIND_TRACE_API("_Unwind_Resume(ex_obj=%p)\n", (void *)exception_object);
   unw_context_t uc;
+  unw_cursor_t cursor;
   unw_getcontext(&uc);
 
   if (exception_object->private_1 != 0)
-    unwind_phase2_forced(&uc, exception_object,
+    unwind_phase2_forced(&uc, &cursor, exception_object,
                          (_Unwind_Stop_Fn) exception_object->private_1,
                          (void *)exception_object->private_2);
   else
-    unwind_phase2(&uc, exception_object);
+    unwind_phase2(&uc, &cursor, exception_object);
 
   // Clients assume _Unwind_Resume() does not return, so all we can do is abort.
   _LIBUNWIND_ABORT("_Unwind_Resume() can't return");
@@ -403,6 +402,7 @@ _Unwind_ForcedUnwind(_Unwind_Exception *exception_object,
   _LIBUNWIND_TRACE_API("_Unwind_ForcedUnwind(ex_obj=%p, stop=%p)\n",
                        (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
@@ -411,7 +411,7 @@ _Unwind_ForcedUnwind(_Unwind_Exception *exception_object,
   exception_object->private_2 = (uintptr_t) stop_parameter;
 
   // do it
-  return unwind_phase2_forced(&uc, exception_object, stop, stop_parameter);
+  return unwind_phase2_forced(&uc, &cursor, exception_object, stop, stop_parameter);
 }
 
 
diff --git a/contrib/llvm/projects/libunwind/src/UnwindRegistersRestore.S b/contrib/llvm/projects/libunwind/src/UnwindRegistersRestore.S
index 61e4568..534d795 100644
--- a/contrib/llvm/projects/libunwind/src/UnwindRegistersRestore.S
+++ b/contrib/llvm/projects/libunwind/src/UnwindRegistersRestore.S
@@ -282,8 +282,8 @@ DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind15Registers_arm646jumptoEv)
   ldp    x22,x23, [x0, #0x0B0]
   ldp    x24,x25, [x0, #0x0C0]
   ldp    x26,x27, [x0, #0x0D0]
-  ldp    x28,fp,  [x0, #0x0E0]
-  ldr    lr,      [x0, #0x100]  // restore pc into lr
+  ldp    x28,x29, [x0, #0x0E0]
+  ldr    x30,     [x0, #0x100]  // restore pc into lr
   ldr    x1,      [x0, #0x0F8]
   mov    sp,x1                  // restore sp
 
@@ -306,7 +306,7 @@ DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind15Registers_arm646jumptoEv)
   ldr    d31,     [x0, #0x208]
 
   ldp    x0, x1,  [x0, #0x000]  // restore x0,x1
-  ret    lr                     // jump to pc
+  ret    x30                    // jump to pc
 
 #elif defined(__arm__) && !defined(__APPLE__)
 
diff --git a/contrib/llvm/projects/libunwind/src/UnwindRegistersSave.S b/contrib/llvm/projects/libunwind/src/UnwindRegistersSave.S
index e49566e..ebc9d53 100644
--- a/contrib/llvm/projects/libunwind/src/UnwindRegistersSave.S
+++ b/contrib/llvm/projects/libunwind/src/UnwindRegistersSave.S
@@ -263,11 +263,11 @@ DEFINE_LIBUNWIND_FUNCTION(unw_getcontext)
   stp    x22,x23, [x0, #0x0B0]
   stp    x24,x25, [x0, #0x0C0]
   stp    x26,x27, [x0, #0x0D0]
-  stp    x28,fp,  [x0, #0x0E0]
-  str    lr,      [x0, #0x0F0]
+  stp    x28,x29, [x0, #0x0E0]
+  str    x30,     [x0, #0x0F0]
   mov    x1,sp
   str    x1,      [x0, #0x0F8]
-  str    lr,      [x0, #0x100]    // store return address as pc
+  str    x30,     [x0, #0x100]    // store return address as pc
   // skip cpsr
   stp    d0, d1,  [x0, #0x110]
   stp    d2, d3,  [x0, #0x120]
diff --git a/contrib/llvm/projects/libunwind/src/config.h b/contrib/llvm/projects/libunwind/src/config.h
index 7ebd57f..74c63f0 100644
--- a/contrib/llvm/projects/libunwind/src/config.h
+++ b/contrib/llvm/projects/libunwind/src/config.h
@@ -16,6 +16,7 @@
 
 #include <assert.h>
 #include <stdio.h>
+#include <stdlib.h>
 
 // Define static_assert() unless already defined by compiler.
 #ifndef __has_feature
@@ -29,28 +30,6 @@
 
 // Platform specific configuration defines.
 #ifdef __APPLE__
-  #include <Availability.h>
-  #ifdef __cplusplus
-    extern "C" {
-  #endif
-    void __assert_rtn(const char *, const char *, int, const char *)
-                                                      __attribute__((noreturn));
-  #ifdef __cplusplus
-    }
-  #endif
-
-  #define _LIBUNWIND_BUILD_ZERO_COST_APIS (defined(__i386__) || \
-                                           defined(__x86_64__) || \
-                                           defined(__arm64__) || \
-                                           defined(__mips__))
-  #define _LIBUNWIND_BUILD_SJLJ_APIS      defined(__arm__)
-  #define _LIBUNWIND_SUPPORT_FRAME_APIS   (defined(__i386__) || \
-                                           defined(__x86_64__))
-  #define _LIBUNWIND_EXPORT               __attribute__((visibility("default")))
-  #define _LIBUNWIND_HIDDEN               __attribute__((visibility("hidden")))
-  #define _LIBUNWIND_LOG(msg, ...) fprintf(stderr, "libuwind: " msg, __VA_ARGS__)
-  #define _LIBUNWIND_ABORT(msg) __assert_rtn(__func__, __FILE__, __LINE__, msg)
-
   #if defined(FOR_DYLD)
     #define _LIBUNWIND_SUPPORT_COMPACT_UNWIND 1
     #define _LIBUNWIND_SUPPORT_DWARF_UNWIND   0
@@ -60,36 +39,52 @@
     #define _LIBUNWIND_SUPPORT_DWARF_UNWIND   1
     #define _LIBUNWIND_SUPPORT_DWARF_INDEX    0
   #endif
-
 #else
-  #include <stdlib.h>
+  #if defined(__ARM_DWARF_EH__) || !defined(__arm__)
+    #define _LIBUNWIND_SUPPORT_COMPACT_UNWIND 0
+    #define _LIBUNWIND_SUPPORT_DWARF_UNWIND 1
+    #define _LIBUNWIND_SUPPORT_DWARF_INDEX 1
+  #else
+    #define _LIBUNWIND_SUPPORT_COMPACT_UNWIND 0
+    #define _LIBUNWIND_SUPPORT_DWARF_UNWIND 0
+    #define _LIBUNWIND_SUPPORT_DWARF_INDEX 0
+  #endif
+#endif
+
+// FIXME: these macros are not correct for COFF targets
+#define _LIBUNWIND_EXPORT __attribute__((visibility("default")))
+#define _LIBUNWIND_HIDDEN __attribute__((visibility("hidden")))
 
-  static inline void assert_rtn(const char* func, const char* file, int line, const char* msg)  __attribute__ ((noreturn));
-  static inline void assert_rtn(const char* func, const char* file, int line, const char* msg) {
-    fprintf(stderr, "libunwind: %s %s:%d - %s\n",  func, file, line, msg);
-    assert(false);
-    abort();
-  }
+#if (defined(__APPLE__) && defined(__arm__)) || defined(__USING_SJLJ_EXCEPTIONS__)
+#define _LIBUNWIND_BUILD_SJLJ_APIS 1
+#else
+#define _LIBUNWIND_BUILD_SJLJ_APIS 0
+#endif
 
-  #define _LIBUNWIND_BUILD_ZERO_COST_APIS (defined(__i386__) || \
-                                           defined(__x86_64__) || \
-                                           defined(__arm__) || \
-                                           defined(__aarch64__) || \
-                                           defined(__riscv__))
-  #define _LIBUNWIND_BUILD_SJLJ_APIS      0
-  #define _LIBUNWIND_SUPPORT_FRAME_APIS   (defined(__i386__) || \
-                                           defined(__x86_64__))
-  #define _LIBUNWIND_EXPORT               __attribute__((visibility("default")))
-  #define _LIBUNWIND_HIDDEN               __attribute__((visibility("hidden")))
-  #define _LIBUNWIND_LOG(msg, ...) fprintf(stderr, "libuwind: " msg, __VA_ARGS__)
-  #define _LIBUNWIND_ABORT(msg) assert_rtn(__func__, __FILE__, __LINE__, msg)
+#if defined(__i386__) || defined(__x86_64__)
+#define _LIBUNWIND_SUPPORT_FRAME_APIS 1
+#else
+#define _LIBUNWIND_SUPPORT_FRAME_APIS 0
+#endif
 
-  #define _LIBUNWIND_SUPPORT_COMPACT_UNWIND 0
-  #define _LIBUNWIND_SUPPORT_DWARF_UNWIND !defined(__arm__) || \
-                                          defined(__ARM_DWARF_EH__)
-  #define _LIBUNWIND_SUPPORT_DWARF_INDEX _LIBUNWIND_SUPPORT_DWARF_UNWIND
+#if defined(__i386__) || defined(__x86_64__) ||                                \
+    (!defined(__APPLE__) && defined(__arm__)) ||                               \
+    (defined(__arm64__) || defined(__aarch64__)) ||                            \
+    (defined(__APPLE__) && defined(__mips__)) ||                               \
+    defined(__riscv__)
+#define _LIBUNWIND_BUILD_ZERO_COST_APIS 1
+#else
+#define _LIBUNWIND_BUILD_ZERO_COST_APIS 0
 #endif
 
+#define _LIBUNWIND_ABORT(msg)                                                  \
+  do {                                                                         \
+    fprintf(stderr, "libunwind: %s %s:%d - %s\n", __func__, __FILE__,          \
+            __LINE__, msg);                                                    \
+    fflush(stderr);                                                            \
+    abort();                                                                   \
+  } while (0)
+#define _LIBUNWIND_LOG(msg, ...) fprintf(stderr, "libuwind: " msg, __VA_ARGS__)
 
 // Macros that define away in non-Debug builds
 #ifdef NDEBUG
@@ -125,5 +120,25 @@
   #define _LIBUNWIND_TRACING_UNWINDING logUnwinding()
 #endif
 
+#ifdef __cplusplus
+// Used to fit UnwindCursor and Registers_xxx types against unw_context_t /
+// unw_cursor_t sized memory blocks.
+#if defined(_LIBUNWIND_IS_NATIVE_ONLY)
+# define COMP_OP ==
+#else
+# define COMP_OP <
+#endif
+template <typename _Type, typename _Mem>
+struct check_fit {
+  template <typename T>
+  struct blk_count {
+    static const size_t count =
+      (sizeof(T) + sizeof(uint64_t) - 1) / sizeof(uint64_t);
+  };
+  static const bool does_fit =
+    (blk_count<_Type>::count COMP_OP blk_count<_Mem>::count);
+};
+#undef COMP_OP
+#endif // __cplusplus
 
 #endif // LIBUNWIND_CONFIG_H
diff --git a/contrib/llvm/projects/libunwind/src/libunwind.cpp b/contrib/llvm/projects/libunwind/src/libunwind.cpp
index c4e3e45..f8a4e91 100644
--- a/contrib/llvm/projects/libunwind/src/libunwind.cpp
+++ b/contrib/llvm/projects/libunwind/src/libunwind.cpp
@@ -45,33 +45,29 @@ _LIBUNWIND_EXPORT int unw_init_local(unw_cursor_t *cursor,
   _LIBUNWIND_TRACE_API("unw_init_local(cursor=%p, context=%p)\n",
                        static_cast<void *>(cursor),
                        static_cast<void *>(context));
-  // Use "placement new" to allocate UnwindCursor in the cursor buffer.
 #if defined(__i386__)
-  new ((void *)cursor) UnwindCursor<LocalAddressSpace, Registers_x86>(
-                                 context, LocalAddressSpace::sThisAddressSpace);
+# define REGISTER_KIND Registers_x86
 #elif defined(__x86_64__)
-  new ((void *)cursor) UnwindCursor<LocalAddressSpace, Registers_x86_64>(
-                                 context, LocalAddressSpace::sThisAddressSpace);
+# define REGISTER_KIND Registers_x86_64
 #elif defined(__ppc__)
-  new ((void *)cursor) UnwindCursor<LocalAddressSpace, Registers_ppc>(
-                                 context, LocalAddressSpace::sThisAddressSpace);
-#elif defined(__arm64__) || defined(__aarch64__)
-  new ((void *)cursor) UnwindCursor<LocalAddressSpace, Registers_arm64>(
-                                 context, LocalAddressSpace::sThisAddressSpace);
+# define REGISTER_KIND Registers_ppc
+#elif defined(__aarch64__)
+# define REGISTER_KIND Registers_arm64
 #elif _LIBUNWIND_ARM_EHABI
-  new ((void *)cursor) UnwindCursor<LocalAddressSpace, Registers_arm>(
-                                 context, LocalAddressSpace::sThisAddressSpace);
+# define REGISTER_KIND Registers_arm
 #elif defined(__or1k__)
-  new ((void *)cursor) UnwindCursor<LocalAddressSpace, Registers_or1k>(
-                                 context, LocalAddressSpace::sThisAddressSpace);
-#elif defined(__mips__)
-#warning The MIPS architecture is not supported.
+# define REGISTER_KIND Registers_or1k
 #elif defined(__riscv__)
-  new ((void *)cursor) UnwindCursor<LocalAddressSpace, Registers_riscv>(
-                                 context, LocalAddressSpace::sThisAddressSpace);
+# define REGISTER_KIND Registers_riscv
+#elif defined(__mips__)
+# warning The MIPS architecture is not supported.
 #else
-#error Architecture not supported
+# error Architecture not supported
 #endif
+  // Use "placement new" to allocate UnwindCursor in the cursor buffer.
+  new ((void *)cursor) UnwindCursor<LocalAddressSpace, REGISTER_KIND>(
+                                 context, LocalAddressSpace::sThisAddressSpace);
+#undef REGISTER_KIND
   AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
   co->setInfoBasedOnIPRegister();