[libunwind] Export the unw_* symbols as weak symbols

[phosek]

Summary

libunwind defines the _Unwind_* ABI used by libc++abi. This ABI is a
stable quasi-standard common between multiple implementations such as
LLVM and GNU. The _U* symbol name space is also safely within the symbol
name space that standard C & C++ reserve for the implementation.

Furthermore, libunwind also defines several unw_* symbols, and references
these from the _Unwind_* entry points so the standard/reserved part of
the ABI is dependent on the unw_* part of the ABI. This is not OK for a
C or C++ implementation. The unw_* symbols are reserved for C and extern
"C" used by application code.

This change renames each unw_* function to _unw* and adds a weak alias
unw_* to keep the public <libunwind.h> ABI unchanged for backwards
compatibility. Every reference to unw_* in the implementation has been
changed to use _unw* so that if other unw_* definitions are in force
because nothing uses <libunwind.h> in a particular program, no _Unwind*
code path depends on any unw_* symbol. Furthemore, _unw_* symbols are
hidden, which saves PLT overhead in the shared library case.

In the future, we should consider untangling the unw_* API/ABI from the
_Unwind_* API/ABI. The internal API backing the _Unwind_* ABI
implementation should not rely on any nonstandard symbols not in the
implementation-reserved name space. This would then allow separating the
_Unwind_* API/ABI from unw_* entirely, but that's a more substantial
change that's going to require more significant refactoring.

[mstorsjo]

libunwind/src/assembly.h

96

What assembler syntax is this alias<somesymbol> = <othersymbol>? The LLVM assembler certainly doesn't support it at least. Is it some thing for a microsoft assembler? The rest of this code doesn't assemble with any such tool anyway. Or is it a leftover marker indicating that you meant to do something?

If we go with /alternatename via a pragma on the C level, the corresponding thing here would be an alternatename directive in the exact same way as EXPORT_SYMBOL2 above. If we go with __attribute__((weak,alias())), or __attribute__((alias())) the corresponding thing is the same as for ELF above, with or without the .weak directive.

libunwind/src/config.h

77

This kind of pragma requires building with -fms-extensions for mingw mode (which is the only windows configuration where there's any need to use libunwind at all, as far as I know), which breaks building with gcc (and the directive is only supported by lld, not by ld.bfd). This requires adding unwind_append_if(LIBUNWIND_COMPILE_FLAGS MINGW -fms-extensions) to the main CMakeLists.txt.

That's not a blocker for this change by any means, but I'll just let it be noted that it's a change from how things were before.

The __attribute__((weak, alias())) form does work in both gcc and clang actually though, so that might almost also be an option, but it's a bit messy (both clang and ld.bfd seem to have a bit of gotchas relating to it), so perhaps we shouldn't.

Alternatively, we could also just postpone making them properly weak on mingw (as it's not strictly necessary contrary to e.g. sanitizers), and just do this with a plain __attribute__((alias(#name))) as above, without the weak.

Also, I'm pretty sure that /alternatename requires using __USER_LABEL_PREFIX__ here (judging from how it's used in sanitizers).

[ldionne]

libunwind/src/Unwind-EHABI.cpp

443

I don't think a single leading underscore followed by a lowercase letter is a reserved name (or maybe it is, but only in the global namespace?). I suggest we use two leading underscores for consistency.

[mcgrathr]

libunwind/src/Unwind-EHABI.cpp

443

Single leading _ is reserved for external linkage. _[A-Z_] is reserved for all identifiers in C/C++. So using a single _ is actually fine but since the rules are somewhat arcane and using double __ is safe for all purposes, __ is the most common choice for this purpose just to avoid such confusion.

[rnk]

libunwind/src/config.h

77

Re: __USER_LABEL_PREFIX__, I think that's true. It's a pretty big drawback to /alternatename.

I guess @phosek wants to make llvm libunwind consistently not provide strong definitions of unw_* across all platforms, otherwise I would say just make this whole thing ELF-only, and provide strong aliases of unw_* = _unw_* for non-ELF platforms.

Does libunwind build with MSVC on Windows? I have no idea, personally. I feel like it's only ever brought in if Itanium-style EH is in use, which usually means mingw, or @compnerd's emergent *-windows-itanium ABI, so theoretically, it might build with MSVC.

[mstorsjo]

libunwind/src/config.h

77

I don't think there's anything particularly tricky at all on the C level so far, so I would expect it to build with MSVC just fine. But the assembly files require a gas style assembler.

[phosek]

libunwind/src/assembly.h

96

It's the masm syntax, but I'll replace it with the alternative as you suggested.

libunwind/src/config.h

77

We're only concerned with ELF for our case, but I'd prefer to keep all platforms as similar as possible unless there's technical reason why it cannot be done. It seems like in this case it's still feasible to use the same approach for ELF, COFF and Mach-O.

[mstorsjo]

libunwind/src/config.h

77

Ok. It's probably simplest to proceed with this using alternatename then, and if someone has a concrete need of libunwind built with gcc/ld.bfd, they can propose patches to make it into non-weak aliases for that target, or see if the gcc/mingw/ld.bfd weak aliases really work for their case.

[phosek]

I plan to do some more testing on Windows to ensure that the updated version works properly.

[mstorsjo]

libunwind/src/assembly.h

96

Thanks, this looks great overall now! Just one minor mistake.

The mingw version of the WEAK_ALIAS macro lacks a definition of WEAK_SYMBOL() - to match the C version we probably should just leave it out? With that changed, this compiles and links just fine.

Didn't test the non-mingw codepaths though.

[mstorsjo]

libunwind/src/assembly.h

96

Sorry, I keep coming up with more things...

The alias needs to be exported to be visible outside of the dll. (In that case there's no issue with conflicting non-reserved symbols at all.) And it needs a .globl.

The non-mingw version is missing some # to make string literals. And that requires a few layers of macro indirection.

diff --git a/src/assembly.h b/src/assembly.h
index 3ff959d..1d47e4d 100644
--- a/src/assembly.h
+++ b/src/assembly.h
@@ -93,13 +93,21 @@
 
 #if defined(__MINGW32__)
 #define WEAK_ALIAS(name, aliasname)                                            \
+  .globl SYMBOL_NAME(aliasname) SEPARATOR                                      \
+  EXPORT_SYMBOL(aliasname) SEPARATOR                                           \
   SYMBOL_NAME(aliasname) = SYMBOL_NAME(name)
 #else
-#define WEAK_ALIAS(name, aliasname)                                            \
+
+#define WEAK_ALIAS3(name, aliasname)                                           \
   .section .drectve,"yn" SEPARATOR                                             \
-  .ascii "-alternatename:", SYMBOL_NAME(aliasname), "=",                       \
-                            SYMBOL_NAME(name), "\0" SEPARATOR                  \
+  .ascii "-alternatename:", #aliasname, "=", #name, "\0" SEPARATOR             \
   .text
+#define WEAK_ALIAS2(name, aliasname)                                           \
+  WEAK_ALIAS3(name, aliasname)
+#define WEAK_ALIAS(name, aliasname)                                            \
+  EXPORT_SYMBOL(aliasname) SEPARATOR                                           \
+  WEAK_ALIAS2(SYMBOL_NAME(name), SYMBOL_NAME(aliasname))
+
 #endif
 
 #define NO_EXEC_STACK_DIRECTIVE

[mstorsjo]

libunwind/src/assembly.h

96

I also forgot to mention, the EXPORT_SYMBOL macro needs to add the symbol prefix when building for msvc (or any non-mingw I guess), but not for mingw. But that's a preexisting issue, unrelated to this patch.

[mstorsjo]

libunwind/src/assembly.h

107

Ok, folding the msvc specific SYMBOL_NAME() here seems to work fine. If there were other places where this macro is used, it might have been good to factorize it in there, but this seems to work.

This version of the patch seems to be ok wrt all windows configurations, as far as I can see.

(I don't have a windows-itanium setup available for testing easily, and making clang-cl build this requires a few other hacks, but I managed to get these aspects tested.)

[ldionne]

My only objection was with the single underscore naming, which has been addressed. Removing my "requires changes" and deferring to other reviewers.

[phosek]

In D59921#1449938, @ldionne wrote:

My only objection was with the single underscore naming, which has been addressed. Removing my "requires changes" and deferring to other reviewers.

@mstorsjo is this OK with you as well? If yes then I'm going to go ahead and land it. Thanks a lot for all the testing and help on the Windows side!

[mstorsjo]

Yes, this is fine with me. Thanks for your patience, and sorry that the windows stuff turned out to require so many roundtrips.

Btw, correcting an earlier statement of mine:

I don't think there's anything particularly tricky at all on the C level so far, so I would expect it to build with MSVC just fine. But the assembly files require a gas style assembler.

When I tried, I did run into one issue. UnwindRegistersRestore.S implements functions with itanium C++ mangled signatures, so if built with MSVC, they don't match, and need to be passed via a function with C name mangling. But being able to build it with MSVC is only a theoretical thing anyway (while the windows-itanium case probably is more plausible).

libunwind/src/Registers.hpp

 };
 
 inline Registers_arm::Registers_arm(const void *registers)
   : _use_X_for_vfp_save(false),
     _saved_vfp_d0_d15(false),
     _saved_vfp_d16_d31(false) {
   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.
+  // See __unw_getcontext() note about data.
   memcpy(&_registers, registers, sizeof(_registers));
   memset(&_vfp_d0_d15_pad, 0, sizeof(_vfp_d0_d15_pad));
   memset(&_vfp_d16_d31, 0, sizeof(_vfp_d16_d31));
 #if defined(__ARM_WMMX)
   _saved_iwmmx = false;
   _saved_iwmmx_control = false;
   memset(&_iwmmx, 0, sizeof(_iwmmx));
   memset(&_iwmmx_control, 0, sizeof(_iwmmx_control));
case UNW_ARM_D31:
     return "d31";
   default:
     return "unknown register";
   }
 }
 
 inline bool Registers_arm::validFloatRegister(int regNum) const {
   // NOTE: Consider the intel MMX registers floating points so the
-  // unw_get_fpreg can be used to transmit the 64-bit data back.
+  // __unw_get_fpreg can be used to transmit the 64-bit data back.
   return ((regNum >= UNW_ARM_D0) && (regNum <= UNW_ARM_D31))
 #if defined(__ARM_WMMX)
       || ((regNum >= UNW_ARM_WR0) && (regNum <= UNW_ARM_WR15))
 #endif
       ;
 }
 
 inline unw_fpreg_t Registers_arm::getFloatRegister(int regNum) {

libunwind/src/Unwind-EHABI.cpp

static _Unwind_Reason_Code unwindOneFrame(_Unwind_State state,
   // of the correct stack frame.
   _Unwind_Reason_Code result =
       ProcessDescriptors(state, ucbp, context, format, lsda,
                          ucbp->pr_cache.additional);
 
   if (result != _URC_CONTINUE_UNWIND)
     return result;
 
-  if (unw_step(reinterpret_cast<unw_cursor_t*>(context)) != UNW_STEP_SUCCESS)
+  if (__unw_step(reinterpret_cast<unw_cursor_t *>(context)) != UNW_STEP_SUCCESS)
     return _URC_FAILURE;
   return _URC_CONTINUE_UNWIND;
 }
 
 // Generates mask discriminator for _Unwind_VRS_Pop, e.g. for _UVRSC_CORE /
 // _UVRSD_UINT32.
 uint32_t RegisterMask(uint8_t start, uint8_t count_minus_one) {
   return ((1U << (count_minus_one + 1)) - 1) << start;

 static _Unwind_Reason_Code
 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_init_local(cursor, uc);
+  __unw_init_local(cursor, uc);
 
   // Walk each frame looking for a place to stop.
   for (bool handlerNotFound = true; handlerNotFound;) {
 
     // See if frame has code to run (has personality routine).
     unw_proc_info_t frameInfo;
-    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",
-                                 static_cast<void *>(exception_object));
+    if (__unw_get_proc_info(cursor, &frameInfo) != UNW_ESUCCESS) {
+      _LIBUNWIND_TRACE_UNWINDING(
+          "unwind_phase1(ex_ojb=%p): __unw_get_proc_info "
       return _URC_FATAL_PHASE1_ERROR;
     }
 
     // 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),
+      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(cursor, UNW_REG_IP, &pc);
+      __unw_get_reg(cursor, UNW_REG_IP, &pc);
       _LIBUNWIND_TRACE_UNWINDING(
           "unwind_phase1(ex_ojb=%p): pc=0x%" PRIxPTR ", start_ip=0x%" PRIxPTR ", func=%s, "
           "lsda=0x%" PRIxPTR ", personality=0x%" PRIxPTR,
           static_cast<void *>(exception_object), pc,
           frameInfo.start_ip, functionName,
           frameInfo.lsda, frameInfo.handler);
     }
 
unwind_phase1(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *exception_object) {
   }
   return _URC_NO_REASON;
 }
 
 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_init_local(cursor, uc);
+  __unw_init_local(cursor, uc);
 
   _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p)",
                              static_cast<void *>(exception_object));
   int frame_count = 0;
 
   // Walk each frame until we reach where search phase said to stop.
   while (true) {
     // Ask libunwind to get next frame (skip over first which is
     // _Unwind_RaiseException or _Unwind_Resume).
     //
     // Resume only ever makes sense for 1 frame.
     _Unwind_State state =
         resume ? _US_UNWIND_FRAME_RESUME : _US_UNWIND_FRAME_STARTING;
     if (resume && frame_count == 1) {
       // On a resume, first unwind the _Unwind_Resume() frame. The next frame
       // is now the landing pad for the cleanup from a previous execution of
       // phase2. To continue unwindingly correctly, replace VRS[15] with the
       // IP of the frame that the previous run of phase2 installed the context
       // for. After this, continue unwinding as if normal.
       //
       // See #7.4.6 for details.
-      unw_set_reg(cursor, UNW_REG_IP,
+      __unw_set_reg(cursor, UNW_REG_IP,
                     exception_object->unwinder_cache.reserved2);
       resume = false;
     }
 
     // Get info about this frame.
     unw_word_t sp;
     unw_proc_info_t frameInfo;
-    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_PHASE2_ERROR",
-                                 static_cast<void *>(exception_object));
+    __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 "
       return _URC_FATAL_PHASE2_ERROR;
     }
 
     // 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),
+      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(ex_ojb=%p): start_ip=0x%" PRIxPTR ", func=%s, sp=0x%" PRIxPTR ", "
           "lsda=0x%" PRIxPTR ", personality=0x%" PRIxPTR "",
           static_cast<void *>(exception_object), frameInfo.start_ip,
           functionName, sp, frameInfo.lsda,
           frameInfo.handler);
if (frameInfo.handler != 0) {
       case _URC_INSTALL_CONTEXT:
         _LIBUNWIND_TRACE_UNWINDING(
             "unwind_phase2(ex_ojb=%p): _URC_INSTALL_CONTEXT",
             static_cast<void *>(exception_object));
         // Personality routine says to transfer control to landing pad.
         // We may get control back if landing pad calls _Unwind_Resume().
         if (_LIBUNWIND_TRACING_UNWINDING) {
           unw_word_t pc;
-          unw_get_reg(cursor, UNW_REG_IP, &pc);
-          unw_get_reg(cursor, 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%" PRIxPTR ", sp=0x%" PRIxPTR,
                                      static_cast<void *>(exception_object),
                                      pc, sp);
         }
 
         {
           // 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(cursor, UNW_REG_IP, &pc);
+          __unw_get_reg(cursor, UNW_REG_IP, &pc);
           exception_object->unwinder_cache.reserved2 = (uint32_t)pc;
         }
-        unw_resume(cursor);
-        // unw_resume() only returns if there was an error.
+        __unw_resume(cursor);
+        // __unw_resume() only returns if there was an error.
         return _URC_FATAL_PHASE2_ERROR;
 
       // # EHABI #7.4.3
       case _URC_FAILURE:
         abort();
 
       default:
         // Personality routine returned an unknown result code.

 
 /// Called by __cxa_throw.  Only returns if there is a fatal error.
 _LIBUNWIND_EXPORT _Unwind_Reason_Code
 _Unwind_RaiseException(_Unwind_Exception *exception_object) {
   _LIBUNWIND_TRACE_API("_Unwind_RaiseException(ex_obj=%p)",
                        static_cast<void *>(exception_object));
   unw_context_t uc;
   unw_cursor_t cursor;
-  unw_getcontext(&uc);
+  __unw_getcontext(&uc);
 
   // This field for is for compatibility with GCC to say this isn't a forced
   // unwind. EHABI #7.2
   exception_object->unwinder_cache.reserved1 = 0;
 
   // phase 1: the search phase
   _Unwind_Reason_Code phase1 = unwind_phase1(&uc, &cursor, exception_object);
   if (phase1 != _URC_NO_REASON)

 /// is implemented by having the code call __cxa_rethrow() which
 /// in turn calls _Unwind_Resume_or_Rethrow().
 _LIBUNWIND_EXPORT void
 _Unwind_Resume(_Unwind_Exception *exception_object) {
   _LIBUNWIND_TRACE_API("_Unwind_Resume(ex_obj=%p)",
                        static_cast<void *>(exception_object));
   unw_context_t uc;
   unw_cursor_t cursor;
-  unw_getcontext(&uc);
+  __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);
 
   // Clients assume _Unwind_Resume() does not return, so all we can do is abort.
   _LIBUNWIND_ABORT("_Unwind_Resume() can't return");
 }
 
 /// Called by personality handler during phase 2 to get LSDA for current frame.
 _LIBUNWIND_EXPORT uintptr_t
 _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context) {
   unw_cursor_t *cursor = (unw_cursor_t *)context;
   unw_proc_info_t frameInfo;
   uintptr_t result = 0;
-  if (unw_get_proc_info(cursor, &frameInfo) == UNW_ESUCCESS)
+  if (__unw_get_proc_info(cursor, &frameInfo) == UNW_ESUCCESS)
     result = (uintptr_t)frameInfo.lsda;
   _LIBUNWIND_TRACE_API(
       "_Unwind_GetLanguageSpecificData(context=%p) => 0x%llx",
       static_cast<void *>(context), (long long)result);
   return result;
 }
 
 static uint64_t ValueAsBitPattern(_Unwind_VRS_DataRepresentation representation,
_LIBUNWIND_TRACE_API("_Unwind_VRS_Set(context=%p, regclass=%d, reg=%d, "
                        static_cast<void *>(context), regclass, regno,
                        representation,
                        ValueAsBitPattern(representation, valuep));
   unw_cursor_t *cursor = (unw_cursor_t *)context;
   switch (regclass) {
     case _UVRSC_CORE:
       if (representation != _UVRSD_UINT32 || regno > 15)
         return _UVRSR_FAILED;
-      return unw_set_reg(cursor, (unw_regnum_t)(UNW_ARM_R0 + regno),
+      return __unw_set_reg(cursor, (unw_regnum_t)(UNW_ARM_R0 + regno),
                            *(unw_word_t *)valuep) == UNW_ESUCCESS
                  ? _UVRSR_OK
                  : _UVRSR_FAILED;
     case _UVRSC_VFP:
       if (representation != _UVRSD_VFPX && representation != _UVRSD_DOUBLE)
         return _UVRSR_FAILED;
       if (representation == _UVRSD_VFPX) {
         // Can only touch d0-15 with FSTMFDX.
         if (regno > 15)
           return _UVRSR_FAILED;
-        unw_save_vfp_as_X(cursor);
+        __unw_save_vfp_as_X(cursor);
       } else {
         if (regno > 31)
           return _UVRSR_FAILED;
       }
-      return unw_set_fpreg(cursor, (unw_regnum_t)(UNW_ARM_D0 + regno),
+      return __unw_set_fpreg(cursor, (unw_regnum_t)(UNW_ARM_D0 + regno),
                              *(unw_fpreg_t *)valuep) == UNW_ESUCCESS
                  ? _UVRSR_OK
                  : _UVRSR_FAILED;
 #if defined(__ARM_WMMX)
     case _UVRSC_WMMXC:
       if (representation != _UVRSD_UINT32 || regno > 3)
         return _UVRSR_FAILED;
-      return unw_set_reg(cursor, (unw_regnum_t)(UNW_ARM_WC0 + regno),
+      return __unw_set_reg(cursor, (unw_regnum_t)(UNW_ARM_WC0 + regno),
                            *(unw_word_t *)valuep) == UNW_ESUCCESS
                  ? _UVRSR_OK
                  : _UVRSR_FAILED;
     case _UVRSC_WMMXD:
       if (representation != _UVRSD_DOUBLE || regno > 31)
         return _UVRSR_FAILED;
-      return unw_set_fpreg(cursor, (unw_regnum_t)(UNW_ARM_WR0 + regno),
+      return __unw_set_fpreg(cursor, (unw_regnum_t)(UNW_ARM_WR0 + regno),
                              *(unw_fpreg_t *)valuep) == UNW_ESUCCESS
                  ? _UVRSR_OK
                  : _UVRSR_FAILED;
 #else
     case _UVRSC_WMMXC:
     case _UVRSC_WMMXD:
       break;
 #endif
   }
   _LIBUNWIND_ABORT("unsupported register class");
 }
 
 static _Unwind_VRS_Result
 _Unwind_VRS_Get_Internal(_Unwind_Context *context,
                          _Unwind_VRS_RegClass regclass, uint32_t regno,
                          _Unwind_VRS_DataRepresentation representation,
                          void *valuep) {
   unw_cursor_t *cursor = (unw_cursor_t *)context;
   switch (regclass) {
     case _UVRSC_CORE:
       if (representation != _UVRSD_UINT32 || regno > 15)
         return _UVRSR_FAILED;
-      return unw_get_reg(cursor, (unw_regnum_t)(UNW_ARM_R0 + regno),
+      return __unw_get_reg(cursor, (unw_regnum_t)(UNW_ARM_R0 + regno),
                            (unw_word_t *)valuep) == UNW_ESUCCESS
                  ? _UVRSR_OK
                  : _UVRSR_FAILED;
     case _UVRSC_VFP:
       if (representation != _UVRSD_VFPX && representation != _UVRSD_DOUBLE)
         return _UVRSR_FAILED;
       if (representation == _UVRSD_VFPX) {
         // Can only touch d0-15 with FSTMFDX.
         if (regno > 15)
           return _UVRSR_FAILED;
-        unw_save_vfp_as_X(cursor);
+        __unw_save_vfp_as_X(cursor);
       } else {
         if (regno > 31)
           return _UVRSR_FAILED;
       }
-      return unw_get_fpreg(cursor, (unw_regnum_t)(UNW_ARM_D0 + regno),
+      return __unw_get_fpreg(cursor, (unw_regnum_t)(UNW_ARM_D0 + regno),
                              (unw_fpreg_t *)valuep) == UNW_ESUCCESS
                  ? _UVRSR_OK
                  : _UVRSR_FAILED;
 #if defined(__ARM_WMMX)
     case _UVRSC_WMMXC:
       if (representation != _UVRSD_UINT32 || regno > 3)
         return _UVRSR_FAILED;
-      return unw_get_reg(cursor, (unw_regnum_t)(UNW_ARM_WC0 + regno),
+      return __unw_get_reg(cursor, (unw_regnum_t)(UNW_ARM_WC0 + regno),
                            (unw_word_t *)valuep) == UNW_ESUCCESS
                  ? _UVRSR_OK
                  : _UVRSR_FAILED;
     case _UVRSC_WMMXD:
       if (representation != _UVRSD_DOUBLE || regno > 31)
         return _UVRSR_FAILED;
-      return unw_get_fpreg(cursor, (unw_regnum_t)(UNW_ARM_WR0 + regno),
+      return __unw_get_fpreg(cursor, (unw_regnum_t)(UNW_ARM_WR0 + regno),
                              (unw_fpreg_t *)valuep) == UNW_ESUCCESS
                  ? _UVRSR_OK
                  : _UVRSR_FAILED;
 #else
     case _UVRSC_WMMXC:
     case _UVRSC_WMMXD:
       break;
 #endif
   }

 
 /// Called by personality handler during phase 2 to find the start of the
 /// function.
 _LIBUNWIND_EXPORT uintptr_t
 _Unwind_GetRegionStart(struct _Unwind_Context *context) {
   unw_cursor_t *cursor = (unw_cursor_t *)context;
   unw_proc_info_t frameInfo;
   uintptr_t result = 0;
-  if (unw_get_proc_info(cursor, &frameInfo) == UNW_ESUCCESS)
+  if (__unw_get_proc_info(cursor, &frameInfo) == UNW_ESUCCESS)
     result = (uintptr_t)frameInfo.start_ip;
   _LIBUNWIND_TRACE_API("_Unwind_GetRegionStart(context=%p) => 0x%llX",
                        static_cast<void *>(context), (long long)result);
   return result;
 }
 
 
 /// Called by personality handler during phase 2 if a foreign exception
 // is caught.
 _LIBUNWIND_EXPORT void
 _Unwind_DeleteException(_Unwind_Exception *exception_object) {
   _LIBUNWIND_TRACE_API("_Unwind_DeleteException(ex_obj=%p)",
                        static_cast<void *>(exception_object));
   if (exception_object->exception_cleanup != NULL)
     (*exception_object->exception_cleanup)(_URC_FOREIGN_EXCEPTION_CAUGHT,
                                            exception_object);
 }
 
 extern "C" _LIBUNWIND_EXPORT _Unwind_Reason_Code
 __gnu_unwind_frame(_Unwind_Exception *exception_object,
                    struct _Unwind_Context *context) {
   unw_cursor_t *cursor = (unw_cursor_t *)context;
-  if (unw_step(cursor) != UNW_STEP_SUCCESS)
+  if (__unw_step(cursor) != UNW_STEP_SUCCESS)
     return _URC_FAILURE;
   return _URC_OK;
 }
 
 #endif  // defined(_LIBUNWIND_ARM_EHABI)

libunwind/src/Unwind-seh.cpp

 /// free foreign exceptions.
 static void seh_exc_cleanup(_Unwind_Reason_Code urc, _Unwind_Exception *exc) {
   (void)urc;
   if (exc->exception_class != kSEHExceptionClass)
     _LIBUNWIND_ABORT("SEH cleanup called on non-SEH exception");
   free(exc);
 }
 
-static int _unw_init_seh(unw_cursor_t *cursor, CONTEXT *ctx);
-static DISPATCHER_CONTEXT *_unw_seh_get_disp_ctx(unw_cursor_t *cursor);
-static void _unw_seh_set_disp_ctx(unw_cursor_t *cursor, DISPATCHER_CONTEXT *disp);
+static int __unw_init_seh(unw_cursor_t *cursor, CONTEXT *ctx);
+static DISPATCHER_CONTEXT *__unw_seh_get_disp_ctx(unw_cursor_t *cursor);
+static void __unw_seh_set_disp_ctx(unw_cursor_t *cursor,
+                                   DISPATCHER_CONTEXT *disp);
 
 /// Common implementation of SEH-style handler functions used by Itanium-
 /// style frames.  Depending on how and why it was called, it may do one of:
 ///  a) Delegate to the given Itanium-style personality function; or
 ///  b) Initiate a collided unwind to halt unwinding.
 _LIBUNWIND_EXPORT EXCEPTION_DISPOSITION
 _GCC_specific_handler(PEXCEPTION_RECORD ms_exc, PVOID frame, PCONTEXT ms_ctx,
                       DISPATCHER_CONTEXT *disp, __personality_routine pers) {
#endif
   } else {
     // Foreign exception.
     exc = (_Unwind_Exception *)malloc(sizeof(_Unwind_Exception));
     exc->exception_class = kSEHExceptionClass;
     exc->exception_cleanup = seh_exc_cleanup;
     memset(exc->private_, 0, sizeof(exc->private_));
   }
   if (!ctx) {
-    _unw_init_seh(&cursor, disp->ContextRecord);
-    _unw_seh_set_disp_ctx(&cursor, disp);
-    unw_set_reg(&cursor, UNW_REG_IP, disp->ControlPc-1);
+    __unw_init_seh(&cursor, disp->ContextRecord);
+    __unw_seh_set_disp_ctx(&cursor, disp);
+    __unw_set_reg(&cursor, UNW_REG_IP, disp->ControlPc - 1);
     ctx = (struct _Unwind_Context *)&cursor;
 
     if (!IS_UNWINDING(ms_exc->ExceptionFlags)) {
       if (ours && ms_exc->NumberParameters > 1)
         action =  (_Unwind_Action)(_UA_CLEANUP_PHASE | _UA_FORCE_UNWIND);
       else
         action = _UA_SEARCH_PHASE;
     } else {
case _URC_INSTALL_CONTEXT: {
     // unwind to the target.
     if (ours && !IS_UNWINDING(ms_exc->ExceptionFlags) && ms_exc->NumberParameters > 1)
       return 4 /* ExecptionExecuteHandler in mingw */;
     // This should never happen in phase 1.
     if (!IS_UNWINDING(ms_exc->ExceptionFlags))
       _LIBUNWIND_ABORT("Personality installed context during phase 1!");
 #ifdef __x86_64__
     exc->private_[2] = disp->TargetIp;
-    unw_get_reg(&cursor, UNW_X86_64_RAX, &retval);
-    unw_get_reg(&cursor, UNW_X86_64_RDX, &exc->private_[3]);
+    __unw_get_reg(&cursor, UNW_X86_64_RAX, &retval);
+    __unw_get_reg(&cursor, UNW_X86_64_RDX, &exc->private_[3]);
 #elif defined(__arm__)
     exc->private_[2] = disp->TargetPc;
-    unw_get_reg(&cursor, UNW_ARM_R0, &retval);
-    unw_get_reg(&cursor, UNW_ARM_R1, &exc->private_[3]);
+    __unw_get_reg(&cursor, UNW_ARM_R0, &retval);
+    __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_ARM64_X0, &retval);
+    __unw_get_reg(&cursor, UNW_ARM64_X1, &exc->private_[3]);
 #endif
-    unw_get_reg(&cursor, UNW_REG_IP, &target);
+    __unw_get_reg(&cursor, UNW_REG_IP, &target);
     ms_exc->ExceptionCode = STATUS_GCC_UNWIND;
 #ifdef __x86_64__
     ms_exc->ExceptionInformation[2] = disp->TargetIp;
 #elif defined(__arm__) || defined(__aarch64__)
     ms_exc->ExceptionInformation[2] = disp->TargetPc;
 #endif
     ms_exc->ExceptionInformation[3] = exc->private_[3];
     // Give NTRTL some scratch space to keep track of the collided unwind.
     // Don't use the one that was passed in; we don't want to overwrite the
     // context in the DISPATCHER_CONTEXT.
     CONTEXT new_ctx;
     RtlUnwindEx(frame, (PVOID)target, ms_exc, (PVOID)retval, &new_ctx, disp->HistoryTable);
     _LIBUNWIND_ABORT("RtlUnwindEx() failed");
   }
   // Anything else indicates a serious problem.
   default: return ExceptionContinueExecution;
   }
 }
 
-/// Personality function returned by \c unw_get_proc_info() in SEH contexts.
+/// Personality function returned by \c __unw_get_proc_info() in SEH contexts.
 /// This is a wrapper that calls the real SEH handler function, which in
 /// turn (at least, for Itanium-style frames) calls the real Itanium
 /// personality function (see \c _GCC_specific_handler()).
 extern "C" _Unwind_Reason_Code
 __libunwind_seh_personality(int version, _Unwind_Action state,
                             uint64_t klass, _Unwind_Exception *exc,
                             struct _Unwind_Context *context) {
   (void)version;
   (void)klass;
   EXCEPTION_RECORD ms_exc;
   bool phase2 = (state & (_UA_SEARCH_PHASE|_UA_CLEANUP_PHASE)) == _UA_CLEANUP_PHASE;
   ms_exc.ExceptionCode = STATUS_GCC_THROW;
   ms_exc.ExceptionFlags = 0;
   ms_exc.NumberParameters = 3;
   ms_exc.ExceptionInformation[0] = (ULONG_PTR)exc;
   ms_exc.ExceptionInformation[1] = (ULONG_PTR)context;
   ms_exc.ExceptionInformation[2] = state;
-  DISPATCHER_CONTEXT *disp_ctx = _unw_seh_get_disp_ctx((unw_cursor_t *)context);
+  DISPATCHER_CONTEXT *disp_ctx =
+      __unw_seh_get_disp_ctx((unw_cursor_t *)context);
   EXCEPTION_DISPOSITION ms_act = disp_ctx->LanguageHandler(&ms_exc,
                                                            (PVOID)disp_ctx->EstablisherFrame,
                                                            disp_ctx->ContextRecord,
                                                            disp_ctx);
   switch (ms_act) {
   case ExceptionContinueSearch: return _URC_CONTINUE_UNWIND;
   case 4 /*ExceptionExecuteHandler*/:
     return phase2 ? _URC_INSTALL_CONTEXT : _URC_HANDLER_FOUND;
   default:
     return phase2 ? _URC_FATAL_PHASE2_ERROR : _URC_FATAL_PHASE1_ERROR;
   }
 }
 
 static _Unwind_Reason_Code
 unwind_phase2_forced(unw_context_t *uc,
                      _Unwind_Exception *exception_object,
                      _Unwind_Stop_Fn stop, void *stop_parameter) {
   unw_cursor_t cursor2;
-  unw_init_local(&cursor2, uc);
+  __unw_init_local(&cursor2, uc);
 
   // Walk each frame until we reach where search phase said to stop
-  while (unw_step(&cursor2) > 0) {
+  while (__unw_step(&cursor2) > 0) {
 
     // Update info about this frame.
     unw_proc_info_t frameInfo;
-    if (unw_get_proc_info(&cursor2, &frameInfo) != UNW_ESUCCESS) {
-      _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): unw_step "
+    if (__unw_get_proc_info(&cursor2, &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;
     }
 
     // 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(&cursor2, functionBuf, sizeof(functionBuf),
+      if ((__unw_get_proc_name(&cursor2, 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%" PRIx64
           ", func=%s, lsda=0x%" PRIx64 ", personality=0x%" PRIx64,
           (void *)exception_object, frameInfo.start_ip, functionName,
           frameInfo.lsda, frameInfo.handler);
     }
if (frameInfo.handler != 0) {
         // 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(&cursor2);
+        __unw_resume(&cursor2);
         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;

 /// in turn calls \c _Unwind_Resume_or_Rethrow().
 _LIBUNWIND_EXPORT void
 _Unwind_Resume(_Unwind_Exception *exception_object) {
   _LIBUNWIND_TRACE_API("_Unwind_Resume(ex_obj=%p)", (void *)exception_object);
 
   if (exception_object->private_[0] != 0) {
     unw_context_t uc;
 
-    unw_getcontext(&uc);
+    __unw_getcontext(&uc);
     unwind_phase2_forced(&uc, exception_object,
                          (_Unwind_Stop_Fn) exception_object->private_[0],
                          (void *)exception_object->private_[4]);
   } else {
     // Recover the parameters for the unwind from the exception object
     // so we can start unwinding again.
     EXCEPTION_RECORD ms_exc;
     CONTEXT ms_ctx;

 /// Unwinds stack, calling "stop" function at each frame.
 /// Could be used to implement \c 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_getcontext(&uc);
+  __unw_getcontext(&uc);
 
   // Mark that this is a forced unwind, so _Unwind_Resume() can do
   // the right thing.
   exception_object->private_[0] = (uintptr_t) stop;
   exception_object->private_[4] = (uintptr_t) stop_parameter;
 
   // do it
   return unwind_phase2_forced(&uc, exception_object, stop, stop_parameter);
 }
 
 /// Called by personality handler during phase 2 to get LSDA for current frame.
 _LIBUNWIND_EXPORT uintptr_t
 _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context) {
-  uintptr_t result = (uintptr_t)_unw_seh_get_disp_ctx((unw_cursor_t *)context)->HandlerData;
+  uintptr_t result =
+      (uintptr_t)__unw_seh_get_disp_ctx((unw_cursor_t *)context)->HandlerData;
   _LIBUNWIND_TRACE_API(
       "_Unwind_GetLanguageSpecificData(context=%p) => 0x%" PRIxPTR,
       (void *)context, result);
   return result;
 }
 
 /// Called by personality handler during phase 2 to find the start of the
 /// function.
 _LIBUNWIND_EXPORT uintptr_t
 _Unwind_GetRegionStart(struct _Unwind_Context *context) {
-  DISPATCHER_CONTEXT *disp = _unw_seh_get_disp_ctx((unw_cursor_t *)context);
+  DISPATCHER_CONTEXT *disp = __unw_seh_get_disp_ctx((unw_cursor_t *)context);
   uintptr_t result = (uintptr_t)disp->FunctionEntry->BeginAddress + disp->ImageBase;
   _LIBUNWIND_TRACE_API("_Unwind_GetRegionStart(context=%p) => 0x%" PRIxPTR,
                        (void *)context, result);
   return result;
 }
 
-static int
-_unw_init_seh(unw_cursor_t *cursor, CONTEXT *context) {
+static int __unw_init_seh(unw_cursor_t *cursor, CONTEXT *context) {
 #ifdef _LIBUNWIND_TARGET_X86_64
   new (reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_x86_64> *>(cursor))
       UnwindCursor<LocalAddressSpace, Registers_x86_64>(
           context, LocalAddressSpace::sThisAddressSpace);
   auto *co = reinterpret_cast<AbstractUnwindCursor *>(cursor);
   co->setInfoBasedOnIPRegister();
   return UNW_ESUCCESS;
 #elif defined(_LIBUNWIND_TARGET_ARM)
#elif defined(_LIBUNWIND_TARGET_AARCH64)
   auto *co = reinterpret_cast<AbstractUnwindCursor *>(cursor);
   co->setInfoBasedOnIPRegister();
   return UNW_ESUCCESS;
 #else
   return UNW_EINVAL;
 #endif
 }
 
-static DISPATCHER_CONTEXT *
-_unw_seh_get_disp_ctx(unw_cursor_t *cursor) {
+static DISPATCHER_CONTEXT *__unw_seh_get_disp_ctx(unw_cursor_t *cursor) {
 #ifdef _LIBUNWIND_TARGET_X86_64
   return reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_x86_64> *>(cursor)->getDispatcherContext();
 #elif defined(_LIBUNWIND_TARGET_ARM)
   return reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm> *>(cursor)->getDispatcherContext();
 #elif defined(_LIBUNWIND_TARGET_AARCH64)
   return reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm64> *>(cursor)->getDispatcherContext();
 #else
   return nullptr;
 #endif
 }
 
-static void
-_unw_seh_set_disp_ctx(unw_cursor_t *cursor, DISPATCHER_CONTEXT *disp) {
+static void __unw_seh_set_disp_ctx(unw_cursor_t *cursor,
+                                   DISPATCHER_CONTEXT *disp) {
 #ifdef _LIBUNWIND_TARGET_X86_64
   reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_x86_64> *>(cursor)->setDispatcherContext(disp);
 #elif defined(_LIBUNWIND_TARGET_ARM)
   reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm> *>(cursor)->setDispatcherContext(disp);
 #elif defined(_LIBUNWIND_TARGET_AARCH64)
   reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm64> *>(cursor)->setDispatcherContext(disp);
 #endif
 }
 
 #endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)

libunwind/src/Unwind-sjlj.c

unwind_phase2(struct _Unwind_Exception *exception_object) {
   // walk each frame until we reach where search phase said to stop
   _Unwind_FunctionContext_t c = __Unwind_SjLj_GetTopOfFunctionStack();
   while (true) {
     _LIBUNWIND_TRACE_UNWINDING("unwind_phase2s(ex_ojb=%p): context=%p",
                                (void *)exception_object, (void *)c);
 
     // check for no more frames
     if (c == NULL) {
-      _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step() reached "
-                                 "bottom => _URC_END_OF_STACK",
-                                 (void *)exception_object);
+      _LIBUNWIND_TRACE_UNWINDING(
+          "unwind_phase2(ex_ojb=%p): __unw_step() reached "
       return _URC_END_OF_STACK;
     }
 
     // if there is a personality routine, tell it we are unwinding
     if (c->personality != NULL) {
       _Unwind_Action action = _UA_CLEANUP_PHASE;
       if ((uintptr_t) c == exception_object->private_2)
         action = (_Unwind_Action)(
if (c->personality != NULL) {
         _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): "
                                    "_URC_INSTALL_CONTEXT, will resume at "
                                    "landing pad %p",
                                    (void *)exception_object, c->jbuf[1]);
         // personality routine says to transfer control to landing pad
         // we may get control back if landing pad calls _Unwind_Resume()
         __Unwind_SjLj_SetTopOfFunctionStack(c);
         __builtin_longjmp(c->jbuf, 1);
-        // unw_resume() only returns if there was an error
+        // __unw_resume() only returns if there was an error
         return _URC_FATAL_PHASE2_ERROR;
       default:
         // something went wrong
         _LIBUNWIND_DEBUG_LOG("personality function returned unknown result %d",
                       personalityResult);
         return _URC_FATAL_PHASE2_ERROR;
       }
     }

 unwind_phase2_forced(struct _Unwind_Exception *exception_object,
                      _Unwind_Stop_Fn stop, void *stop_parameter) {
   // walk each frame until we reach where search phase said to stop
   _Unwind_FunctionContext_t c = __Unwind_SjLj_GetTopOfFunctionStack();
   while (true) {
 
     // get next frame (skip over first which is _Unwind_RaiseException)
     if (c == NULL) {
-      _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step() reached "
-                                 "bottom => _URC_END_OF_STACK",
-                                 (void *)exception_object);
+      _LIBUNWIND_TRACE_UNWINDING(
+          "unwind_phase2(ex_ojb=%p): __unw_step() reached "
       return _URC_END_OF_STACK;
     }
 
     // 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,

libunwind/src/UnwindLevel1-gcc-ext.c

 /// specified code address "pc".
 _LIBUNWIND_EXPORT void *_Unwind_FindEnclosingFunction(void *pc) {
   _LIBUNWIND_TRACE_API("_Unwind_FindEnclosingFunction(pc=%p)", pc);
   // This is slow, but works.
   // We create an unwind cursor then alter the IP to be pc
   unw_cursor_t cursor;
   unw_context_t uc;
   unw_proc_info_t info;
-  unw_getcontext(&uc);
-  unw_init_local(&cursor, &uc);
-  unw_set_reg(&cursor, UNW_REG_IP, (unw_word_t)(intptr_t) pc);
-  if (unw_get_proc_info(&cursor, &info) == UNW_ESUCCESS)
+  __unw_getcontext(&uc);
+  __unw_init_local(&cursor, &uc);
+  __unw_set_reg(&cursor, UNW_REG_IP, (unw_word_t)(intptr_t)pc);
+  if (__unw_get_proc_info(&cursor, &info) == UNW_ESUCCESS)
     return (void *)(intptr_t) info.start_ip;
   else
     return NULL;
 }
 
 /// Walk every frame and call trace function at each one.  If trace function
 /// returns anything other than _URC_NO_REASON, then walk is terminated.
 _LIBUNWIND_EXPORT _Unwind_Reason_Code
 _Unwind_Backtrace(_Unwind_Trace_Fn callback, void *ref) {
   unw_cursor_t cursor;
   unw_context_t uc;
-  unw_getcontext(&uc);
-  unw_init_local(&cursor, &uc);
+  __unw_getcontext(&uc);
+  __unw_init_local(&cursor, &uc);
 
   _LIBUNWIND_TRACE_API("_Unwind_Backtrace(callback=%p)",
                        (void *)(uintptr_t)callback);
 
 #if defined(_LIBUNWIND_ARM_EHABI)
   // Create a mock exception object for force unwinding.
   _Unwind_Exception ex;
   memset(&ex, '\0', sizeof(ex));
   ex.exception_class = 0x434C4E47554E5700; // CLNGUNW\0
 #endif
 
   // walk each frame
   while (true) {
     _Unwind_Reason_Code result;
 
 #if !defined(_LIBUNWIND_ARM_EHABI)
     // ask libunwind to get next frame (skip over first frame which is
     // _Unwind_Backtrace())
-    if (unw_step(&cursor) <= 0) {
+    if (__unw_step(&cursor) <= 0) {
       _LIBUNWIND_TRACE_UNWINDING(" _backtrace: ended because cursor reached "
                                  "bottom of stack, returning %d",
                                  _URC_END_OF_STACK);
       return _URC_END_OF_STACK;
     }
 #else
     // Get the information for this frame.
     unw_proc_info_t frameInfo;
-    if (unw_get_proc_info(&cursor, &frameInfo) != UNW_ESUCCESS) {
+    if (__unw_get_proc_info(&cursor, &frameInfo) != UNW_ESUCCESS) {
       return _URC_END_OF_STACK;
     }
 
     // Update the pr_cache in the mock exception object.
     const uint32_t* unwindInfo = (uint32_t *) frameInfo.unwind_info;
     ex.pr_cache.fnstart = frameInfo.start_ip;
     ex.pr_cache.ehtp = (_Unwind_EHT_Header *) unwindInfo;
     ex.pr_cache.additional= frameInfo.flags;
#else
     }
 #endif // defined(_LIBUNWIND_ARM_EHABI)
 
     // debugging
     if (_LIBUNWIND_TRACING_UNWINDING) {
       char functionName[512];
       unw_proc_info_t frame;
       unw_word_t offset;
-      unw_get_proc_name(&cursor, functionName, 512, &offset);
-      unw_get_proc_info(&cursor, &frame);
+      __unw_get_proc_name(&cursor, functionName, 512, &offset);
+      __unw_get_proc_info(&cursor, &frame);
       _LIBUNWIND_TRACE_UNWINDING(
           " _backtrace: start_ip=0x%" PRIxPTR ", func=%s, lsda=0x%" PRIxPTR ", context=%p",
           frame.start_ip, functionName, frame.lsda,
           (void *)&cursor);
     }
 
     // call trace function with this frame
     result = (*callback)((struct _Unwind_Context *)(&cursor), ref);

 /// Find DWARF unwind info for an address 'pc' in some function.
 _LIBUNWIND_EXPORT const void *_Unwind_Find_FDE(const void *pc,
                                                struct dwarf_eh_bases *bases) {
   // This is slow, but works.
   // We create an unwind cursor then alter the IP to be pc
   unw_cursor_t cursor;
   unw_context_t uc;
   unw_proc_info_t info;
-  unw_getcontext(&uc);
-  unw_init_local(&cursor, &uc);
-  unw_set_reg(&cursor, UNW_REG_IP, (unw_word_t)(intptr_t) pc);
-  unw_get_proc_info(&cursor, &info);
+  __unw_getcontext(&uc);
+  __unw_init_local(&cursor, &uc);
+  __unw_set_reg(&cursor, UNW_REG_IP, (unw_word_t)(intptr_t)pc);
+  __unw_get_proc_info(&cursor, &info);
   bases->tbase = (uintptr_t)info.extra;
   bases->dbase = 0; // dbase not used on Mac OS X
   bases->func = (uintptr_t)info.start_ip;
   _LIBUNWIND_TRACE_API("_Unwind_Find_FDE(pc=%p) => %p", pc,
                   (void *)(intptr_t) info.unwind_info);
   return (void *)(intptr_t) info.unwind_info;
 }
 
 /// Returns the CFA (call frame area, or stack pointer at start of function)
 /// for the current context.
 _LIBUNWIND_EXPORT uintptr_t _Unwind_GetCFA(struct _Unwind_Context *context) {
   unw_cursor_t *cursor = (unw_cursor_t *)context;
   unw_word_t result;
-  unw_get_reg(cursor, UNW_REG_SP, &result);
+  __unw_get_reg(cursor, UNW_REG_SP, &result);
   _LIBUNWIND_TRACE_API("_Unwind_GetCFA(context=%p) => 0x%" PRIxPTR,
                        (void *)context, result);
   return (uintptr_t)result;
 }
 
 
 /// Called by personality handler during phase 2 to get instruction pointer.
 /// ipBefore is a boolean that says if IP is already adjusted to be the call
 /// site address.  Normally IP is the return address.
 _LIBUNWIND_EXPORT uintptr_t _Unwind_GetIPInfo(struct _Unwind_Context *context,
                                               int *ipBefore) {
   _LIBUNWIND_TRACE_API("_Unwind_GetIPInfo(context=%p)", (void *)context);
   *ipBefore = 0;
   return _Unwind_GetIP(context);
 }
 
 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
 
 /// Called by programs with dynamic code generators that want
 /// to register a dynamically generated FDE.
 /// This function has existed on Mac OS X since 10.4, but
 /// was broken until 10.6.
 _LIBUNWIND_EXPORT void __register_frame(const void *fde) {
   _LIBUNWIND_TRACE_API("__register_frame(%p)", fde);
-  _unw_add_dynamic_fde((unw_word_t)(uintptr_t) fde);
+  __unw_add_dynamic_fde((unw_word_t)(uintptr_t)fde);
 }
 
 
 /// Called by programs with dynamic code generators that want
 /// to unregister a dynamically generated FDE.
 /// This function has existed on Mac OS X since 10.4, but
 /// was broken until 10.6.
 _LIBUNWIND_EXPORT void __deregister_frame(const void *fde) {
   _LIBUNWIND_TRACE_API("__deregister_frame(%p)", fde);
-  _unw_remove_dynamic_fde((unw_word_t)(uintptr_t) fde);
+  __unw_remove_dynamic_fde((unw_word_t)(uintptr_t)fde);
 }
 
 
 // The following register/deregister functions are gcc extensions.
 // They have existed on Mac OS X, but have never worked because Mac OS X
 // before 10.6 used keymgr to track known FDEs, but these functions
 // never got updated to use keymgr.
 // For now, we implement these as do-nothing functions to keep any existing

libunwind/src/UnwindLevel1.c

 
 #include <inttypes.h>
 #include <stdint.h>
 #include <stdbool.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
 
+#include "config.h"
 #include "libunwind.h"
+#include "libunwind_ext.h"
 #include "unwind.h"
-#include "config.h"
 
 #if !defined(_LIBUNWIND_ARM_EHABI) && !defined(__USING_SJLJ_EXCEPTIONS__)
 
 #ifndef _LIBUNWIND_SUPPORT_SEH_UNWIND
 
 static _Unwind_Reason_Code
 unwind_phase1(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *exception_object) {
-  unw_init_local(cursor, uc);
+  __unw_init_local(cursor, uc);
 
   // Walk each frame looking for a place to stop.
   bool handlerNotFound = true;
   while (handlerNotFound) {
     // Ask libunwind to get next frame (skip over first which is
     // _Unwind_RaiseException).
-    int stepResult = unw_step(cursor);
+    int stepResult = __unw_step(cursor);
     if (stepResult == 0) {
-      _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_step() reached "
-                                 "bottom => _URC_END_OF_STACK",
-                                 (void *)exception_object);
+      _LIBUNWIND_TRACE_UNWINDING(
+          "unwind_phase1(ex_ojb=%p): __unw_step() reached "
       return _URC_END_OF_STACK;
     } else if (stepResult < 0) {
-      _LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_step failed => "
-                                 "_URC_FATAL_PHASE1_ERROR",
-                                 (void *)exception_object);
+      _LIBUNWIND_TRACE_UNWINDING(
+          "unwind_phase1(ex_ojb=%p): __unw_step failed => "
       return _URC_FATAL_PHASE1_ERROR;
     }
 
     // See if frame has code to run (has personality routine).
     unw_proc_info_t frameInfo;
     unw_word_t sp;
-    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",
-                                 (void *)exception_object);
+    if (__unw_get_proc_info(cursor, &frameInfo) != UNW_ESUCCESS) {
+      _LIBUNWIND_TRACE_UNWINDING(
+          "unwind_phase1(ex_ojb=%p): __unw_get_proc_info "
       return _URC_FATAL_PHASE1_ERROR;
     }
 
     // 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),
+      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(cursor, UNW_REG_IP, &pc);
+      __unw_get_reg(cursor, UNW_REG_IP, &pc);
       _LIBUNWIND_TRACE_UNWINDING(
           "unwind_phase1(ex_ojb=%p): pc=0x%" PRIxPTR ", start_ip=0x%" PRIxPTR
           ", func=%s, lsda=0x%" PRIxPTR ", personality=0x%" PRIxPTR "",
           (void *)exception_object, pc, frameInfo.start_ip, functionName,
           frameInfo.lsda, frameInfo.handler);
     }
 
     // If there is a personality routine, ask it if it will want to stop at
     // this frame.
     if (frameInfo.handler != 0) {
       __personality_routine p =
           (__personality_routine)(uintptr_t)(frameInfo.handler);
       _LIBUNWIND_TRACE_UNWINDING(
           "unwind_phase1(ex_ojb=%p): calling personality function %p",
           (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 *)(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(cursor, 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",
             (void *)exception_object);
         return _URC_NO_REASON;
 
       case _URC_CONTINUE_UNWIND:
         _LIBUNWIND_TRACE_UNWINDING(
while (handlerNotFound) {
     }
   }
   return _URC_NO_REASON;
 }
 
 
 static _Unwind_Reason_Code
 unwind_phase2(unw_context_t *uc, unw_cursor_t *cursor, _Unwind_Exception *exception_object) {
-  unw_init_local(cursor, uc);
+  __unw_init_local(cursor, uc);
 
   _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p)",
                              (void *)exception_object);
 
   // Walk each frame until we reach where search phase said to stop.
   while (true) {
 
     // Ask libunwind to get next frame (skip over first which is
     // _Unwind_RaiseException).
-    int stepResult = unw_step(cursor);
+    int stepResult = __unw_step(cursor);
     if (stepResult == 0) {
-      _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step() reached "
-                                 "bottom => _URC_END_OF_STACK",
-                                 (void *)exception_object);
+      _LIBUNWIND_TRACE_UNWINDING(
+          "unwind_phase2(ex_ojb=%p): __unw_step() reached "
       return _URC_END_OF_STACK;
     } else if (stepResult < 0) {
-      _LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step failed => "
-                                 "_URC_FATAL_PHASE1_ERROR",
-                                 (void *)exception_object);
+      _LIBUNWIND_TRACE_UNWINDING(
+          "unwind_phase2(ex_ojb=%p): __unw_step failed => "
       return _URC_FATAL_PHASE2_ERROR;
     }
 
     // Get info about this frame.
     unw_word_t sp;
     unw_proc_info_t frameInfo;
-    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",
-                                 (void *)exception_object);
+    __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 "
       return _URC_FATAL_PHASE2_ERROR;
     }
 
     // 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),
+      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(ex_ojb=%p): start_ip=0x%" PRIxPTR
                                  ", func=%s, sp=0x%" PRIxPTR ", lsda=0x%" PRIxPTR
                                  ", personality=0x%" PRIxPTR,
                                  (void *)exception_object, frameInfo.start_ip,
                                  functionName, sp, frameInfo.lsda,
                                  frameInfo.handler);
if (frameInfo.handler != 0) {
       case _URC_INSTALL_CONTEXT:
         _LIBUNWIND_TRACE_UNWINDING(
             "unwind_phase2(ex_ojb=%p): _URC_INSTALL_CONTEXT",
             (void *)exception_object);
         // Personality routine says to transfer control to landing pad.
         // We may get control back if landing pad calls _Unwind_Resume().
         if (_LIBUNWIND_TRACING_UNWINDING) {
           unw_word_t pc;
-          unw_get_reg(cursor, UNW_REG_IP, &pc);
-          unw_get_reg(cursor, 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%" PRIxPTR
                                      ", sp=0x%" PRIxPTR,
                                      (void *)exception_object, pc, sp);
         }
-        unw_resume(cursor);
-        // unw_resume() only returns if there was an error.
+        __unw_resume(cursor);
+        // __unw_resume() only returns if there was an error.
         return _URC_FATAL_PHASE2_ERROR;
       default:
         // Personality routine returned an unknown result code.
         _LIBUNWIND_DEBUG_LOG("personality function returned unknown result %d",
                              personalityResult);
         return _URC_FATAL_PHASE2_ERROR;
       }
     }
   }
 
   // Clean up phase did not resume at the frame that the search phase
   // said it would...
   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) {
-  unw_init_local(cursor, uc);
+  __unw_init_local(cursor, uc);
 
   // Walk each frame until we reach where search phase said to stop
-  while (unw_step(cursor) > 0) {
+  while (__unw_step(cursor) > 0) {
 
     // 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 "
+    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;
     }
 
     // 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),
+      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);
     }
if (frameInfo.handler != 0) {
         // 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);
+        __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;

 
 /// Called by __cxa_throw.  Only returns if there is a fatal error.
 _LIBUNWIND_EXPORT _Unwind_Reason_Code
 _Unwind_RaiseException(_Unwind_Exception *exception_object) {
   _LIBUNWIND_TRACE_API("_Unwind_RaiseException(ex_obj=%p)",
                        (void *)exception_object);
   unw_context_t uc;
   unw_cursor_t cursor;
-  unw_getcontext(&uc);
+  __unw_getcontext(&uc);
 
   // Mark that this is a non-forced unwind, so _Unwind_Resume()
   // can do the right thing.
   exception_object->private_1 = 0;
   exception_object->private_2 = 0;
 
   // phase 1: the search phase
   _Unwind_Reason_Code phase1 = unwind_phase1(&uc, &cursor, exception_object);

 /// Note: re-throwing an exception (as opposed to continuing the unwind)
 /// is implemented by having the code call __cxa_rethrow() which
 /// in turn calls _Unwind_Resume_or_Rethrow().
 _LIBUNWIND_EXPORT void
 _Unwind_Resume(_Unwind_Exception *exception_object) {
   _LIBUNWIND_TRACE_API("_Unwind_Resume(ex_obj=%p)", (void *)exception_object);
   unw_context_t uc;
   unw_cursor_t cursor;
-  unw_getcontext(&uc);
+  __unw_getcontext(&uc);
 
   if (exception_object->private_1 != 0)
     unwind_phase2_forced(&uc, &cursor, exception_object,
                          (_Unwind_Stop_Fn) exception_object->private_1,
                          (void *)exception_object->private_2);
   else
     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");
 }
 
 
 
 /// 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);
+  __unw_getcontext(&uc);
 
   // Mark that this is a forced unwind, so _Unwind_Resume() can do
   // the right thing.
   exception_object->private_1 = (uintptr_t) stop;
   exception_object->private_2 = (uintptr_t) stop_parameter;
 
   // do it
   return unwind_phase2_forced(&uc, &cursor, exception_object, stop, stop_parameter);
 }
 
 
 /// Called by personality handler during phase 2 to get LSDA for current frame.
 _LIBUNWIND_EXPORT uintptr_t
 _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context) {
   unw_cursor_t *cursor = (unw_cursor_t *)context;
   unw_proc_info_t frameInfo;
   uintptr_t result = 0;
-  if (unw_get_proc_info(cursor, &frameInfo) == UNW_ESUCCESS)
+  if (__unw_get_proc_info(cursor, &frameInfo) == UNW_ESUCCESS)
     result = (uintptr_t)frameInfo.lsda;
   _LIBUNWIND_TRACE_API(
       "_Unwind_GetLanguageSpecificData(context=%p) => 0x%" PRIxPTR,
       (void *)context, result);
   if (result != 0) {
     if (*((uint8_t *)result) != 0xFF)
       _LIBUNWIND_DEBUG_LOG("lsda at 0x%" PRIxPTR " does not start with 0xFF",
                            result);
   }
   return result;
 }
 
 
 /// Called by personality handler during phase 2 to find the start of the
 /// function.
 _LIBUNWIND_EXPORT uintptr_t
 _Unwind_GetRegionStart(struct _Unwind_Context *context) {
   unw_cursor_t *cursor = (unw_cursor_t *)context;
   unw_proc_info_t frameInfo;
   uintptr_t result = 0;
-  if (unw_get_proc_info(cursor, &frameInfo) == UNW_ESUCCESS)
+  if (__unw_get_proc_info(cursor, &frameInfo) == UNW_ESUCCESS)
     result = (uintptr_t)frameInfo.start_ip;
   _LIBUNWIND_TRACE_API("_Unwind_GetRegionStart(context=%p) => 0x%" PRIxPTR,
                        (void *)context, result);
   return result;
 }
 
 #endif // !_LIBUNWIND_SUPPORT_SEH_UNWIND
 
 /// Called by personality handler during phase 2 if a foreign exception
 // is caught.
 _LIBUNWIND_EXPORT void
 _Unwind_DeleteException(_Unwind_Exception *exception_object) {
   _LIBUNWIND_TRACE_API("_Unwind_DeleteException(ex_obj=%p)",
                        (void *)exception_object);
   if (exception_object->exception_cleanup != NULL)
     (*exception_object->exception_cleanup)(_URC_FOREIGN_EXCEPTION_CAUGHT,
                                            exception_object);
 }
 
 /// Called by personality handler during phase 2 to get register values.
 _LIBUNWIND_EXPORT uintptr_t
 _Unwind_GetGR(struct _Unwind_Context *context, int index) {
   unw_cursor_t *cursor = (unw_cursor_t *)context;
   unw_word_t result;
-  unw_get_reg(cursor, index, &result);
+  __unw_get_reg(cursor, index, &result);
   _LIBUNWIND_TRACE_API("_Unwind_GetGR(context=%p, reg=%d) => 0x%" PRIxPTR,
                        (void *)context, index, result);
   return (uintptr_t)result;
 }
 
 /// Called by personality handler during phase 2 to alter register values.
 _LIBUNWIND_EXPORT void _Unwind_SetGR(struct _Unwind_Context *context, int index,
                                      uintptr_t value) {
   _LIBUNWIND_TRACE_API("_Unwind_SetGR(context=%p, reg=%d, value=0x%0" PRIxPTR
                        ")",
                        (void *)context, index, value);
   unw_cursor_t *cursor = (unw_cursor_t *)context;
-  unw_set_reg(cursor, index, value);
+  __unw_set_reg(cursor, index, value);
 }
 
 /// Called by personality handler during phase 2 to get instruction pointer.
 _LIBUNWIND_EXPORT uintptr_t _Unwind_GetIP(struct _Unwind_Context *context) {
   unw_cursor_t *cursor = (unw_cursor_t *)context;
   unw_word_t result;
-  unw_get_reg(cursor, UNW_REG_IP, &result);
+  __unw_get_reg(cursor, UNW_REG_IP, &result);
   _LIBUNWIND_TRACE_API("_Unwind_GetIP(context=%p) => 0x%" PRIxPTR,
                        (void *)context, result);
   return (uintptr_t)result;
 }
 
 /// Called by personality handler during phase 2 to alter instruction pointer,
 /// such as setting where the landing pad is, so _Unwind_Resume() will
 /// start executing in the landing pad.
 _LIBUNWIND_EXPORT void _Unwind_SetIP(struct _Unwind_Context *context,
                                      uintptr_t value) {
   _LIBUNWIND_TRACE_API("_Unwind_SetIP(context=%p, value=0x%0" PRIxPTR ")",
                        (void *)context, value);
   unw_cursor_t *cursor = (unw_cursor_t *)context;
-  unw_set_reg(cursor, UNW_REG_IP, value);
+  __unw_set_reg(cursor, UNW_REG_IP, value);
 }
 
 #endif // !defined(_LIBUNWIND_ARM_EHABI) && !defined(__USING_SJLJ_EXCEPTIONS__)

libunwind/src/UnwindRegistersRestore.S

 //===-------------------- 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.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "assembly.h"
 
   .text
 
 #if !defined(__USING_SJLJ_EXCEPTIONS__)
 
 #if defined(__i386__)
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind13Registers_x866jumptoEv)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind13Registers_x866jumptoEv)
 #
 # void libunwind::Registers_x86::jumpto()
 #
 #if defined(_WIN32)
 # On windows, the 'this' pointer is passed in ecx instead of on the stack
   movl   %ecx, %eax
 #else
 # On entry:
#endif
   # skip cs
   # skip ds
   # skip es
   # skip fs
   # skip gs
 
 #elif defined(__x86_64__)
 
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind16Registers_x86_646jumptoEv)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind16Registers_x86_646jumptoEv)
 #
 # void libunwind::Registers_x86_64::jumpto()
 #
 #if defined(_WIN64)
 # On entry, thread_state pointer is in rcx; move it into rdi
 # to share restore code below. Since this routine restores and
 # overwrites all registers, we can use the same registers for
 # pointers and temporaries as on unix even though win64 normally

 #endif
   movq  56(%rdi), %rsp  # cut back rsp to new location
   pop    %rdi      # rdi was saved here earlier
   ret            # rip was saved here
 
 
 #elif defined(__powerpc64__)
 
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind15Registers_ppc646jumptoEv)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind15Registers_ppc646jumptoEv)
 //
 // void libunwind::Registers_ppc64::jumpto()
 //
 // On entry:
 //  thread_state pointer is in r3
 //
 
 // load register (GPR)
Lnovec:
   PPC64_LR(5)
   PPC64_LR(4)
   PPC64_LR(1)
   PPC64_LR(3)
   bctr
 
 #elif defined(__ppc__)
 
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind13Registers_ppc6jumptoEv)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind13Registers_ppc6jumptoEv)
 ;
 ; void libunwind::Registers_ppc::jumpto()
 ;
 ; On entry:
 ;  thread_state pointer is in r3
 ;
 
   ; restore integral registerrs

 
 //
 // void libunwind::Registers_arm64::jumpto()
 //
 // On entry:
 //  thread_state pointer is in x0
 //
   .p2align 2
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind15Registers_arm646jumptoEv)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind15Registers_arm646jumptoEv)
   // skip restore of x0,x1 for now
   ldp    x2, x3,  [x0, #0x010]
   ldp    x4, x5,  [x0, #0x020]
   ldp    x6, x7,  [x0, #0x030]
   ldp    x8, x9,  [x0, #0x040]
   ldp    x10,x11, [x0, #0x050]
   ldp    x12,x13, [x0, #0x060]
   ldp    x14,x15, [x0, #0x070]

 
 @
 @ void libunwind::Registers_arm::restoreCoreAndJumpTo()
 @
 @ On entry:
 @  thread_state pointer is in r0
 @
   .p2align 2
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind13Registers_arm20restoreCoreAndJumpToEv)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind13Registers_arm20restoreCoreAndJumpToEv)
 #if !defined(__ARM_ARCH_ISA_ARM) && __ARM_ARCH_ISA_THUMB == 1
   @ r8-r11: ldm into r1-r4, then mov to r8-r11
   adds r0, #0x20
   ldm r0!, {r1-r4}
   subs r0, #0x30
   mov r8, r1
   mov r9, r2
   mov r10, r3

 @
 @ On entry:
 @  values pointer is in r0
 @
   .p2align 2
 #if defined(__ELF__)
   .fpu vfpv3-d16
 #endif
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind13Registers_arm19restoreVFPWithFLDMDEPv)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind13Registers_arm19restoreVFPWithFLDMDEPv)
   @ VFP and iwMMX instructions are only available when compiling with the flags
   @ that enable them. We do not want to do that in the library (because we do not
   @ want the compiler to generate instructions that access those) but this is
   @ only accessed if the personality routine needs these registers. Use of
   @ these registers implies they are, actually, available on the target, so
   @ it's ok to execute.
   @ So, generate the instruction using the corresponding coprocessor mnemonic.
   vldmia r0, {d0-d15}
   JMP(lr)
 
 @
 @ static void libunwind::Registers_arm::restoreVFPWithFLDMX(unw_fpreg_t* values)
 @
 @ On entry:
 @  values pointer is in r0
 @
   .p2align 2
 #if defined(__ELF__)
   .fpu vfpv3-d16
 #endif
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind13Registers_arm19restoreVFPWithFLDMXEPv)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind13Registers_arm19restoreVFPWithFLDMXEPv)
   vldmia r0, {d0-d15} @ fldmiax is deprecated in ARMv7+ and now behaves like vldmia
   JMP(lr)
 
 @
 @ static void libunwind::Registers_arm::restoreVFPv3(unw_fpreg_t* values)
 @
 @ On entry:
 @  values pointer is in r0
 @
   .p2align 2
 #if defined(__ELF__)
   .fpu vfpv3
 #endif
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind13Registers_arm12restoreVFPv3EPv)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind13Registers_arm12restoreVFPv3EPv)
   vldmia r0, {d16-d31}
   JMP(lr)
 
 #if defined(__ARM_WMMX)
 
 @
 @ static void libunwind::Registers_arm::restoreiWMMX(unw_fpreg_t* values)
 @
 @ On entry:
 @  values pointer is in r0
 @
   .p2align 2
 #if defined(__ELF__)
   .arch armv5te
 #endif
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind13Registers_arm12restoreiWMMXEPv)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind13Registers_arm12restoreiWMMXEPv)
   ldcl p1, cr0, [r0], #8  @ wldrd wR0, [r0], #8
   ldcl p1, cr1, [r0], #8  @ wldrd wR1, [r0], #8
   ldcl p1, cr2, [r0], #8  @ wldrd wR2, [r0], #8
   ldcl p1, cr3, [r0], #8  @ wldrd wR3, [r0], #8
   ldcl p1, cr4, [r0], #8  @ wldrd wR4, [r0], #8
   ldcl p1, cr5, [r0], #8  @ wldrd wR5, [r0], #8
   ldcl p1, cr6, [r0], #8  @ wldrd wR6, [r0], #8
   ldcl p1, cr7, [r0], #8  @ wldrd wR7, [r0], #8

 @
 @ On entry:
 @  values pointer is in r0
 @
   .p2align 2
 #if defined(__ELF__)
   .arch armv5te
 #endif
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind13Registers_arm19restoreiWMMXControlEPj)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind13Registers_arm19restoreiWMMXControlEPj)
   ldc2 p1, cr8, [r0], #4  @ wldrw wCGR0, [r0], #4
   ldc2 p1, cr9, [r0], #4  @ wldrw wCGR1, [r0], #4
   ldc2 p1, cr10, [r0], #4  @ wldrw wCGR2, [r0], #4
   ldc2 p1, cr11, [r0], #4  @ wldrw wCGR3, [r0], #4
   JMP(lr)
 
 #endif
 
 #elif defined(__or1k__)
 
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind14Registers_or1k6jumptoEv)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind14Registers_or1k6jumptoEv)
 #
 # void libunwind::Registers_or1k::jumpto()
 #
 # On entry:
 #  thread_state pointer is in r3
 #
 
   # restore integral registers

 #elif defined(__mips__) && defined(_ABIO32) && _MIPS_SIM == _ABIO32
 
 //
 // void libunwind::Registers_mips_o32::jumpto()
 //
 // On entry:
 //  thread state pointer is in a0 ($4)
 //
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind18Registers_mips_o326jumptoEv)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind18Registers_mips_o326jumptoEv)
   .set push
   .set noat
   .set noreorder
   .set nomacro
 #ifdef __mips_hard_float
 #if __mips_fpr != 64
   ldc1  $f0, (4 * 36 + 8 * 0)($4)
   ldc1  $f2, (4 * 36 + 8 * 2)($4)

 #elif defined(__mips64)
 
 //
 // void libunwind::Registers_mips_newabi::jumpto()
 //
 // On entry:
 //  thread state pointer is in a0 ($4)
 //
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind21Registers_mips_newabi6jumptoEv)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind21Registers_mips_newabi6jumptoEv)
   .set push
   .set noat
   .set noreorder
   .set nomacro
 #ifdef __mips_hard_float
   ldc1  $f0, (8 * 35)($4)
   ldc1  $f1, (8 * 36)($4)
   ldc1  $f2, (8 * 37)($4)

 #elif defined(__sparc__)
 
 //
 // void libunwind::Registers_sparc_o32::jumpto()
 //
 // On entry:
 //  thread_state pointer is in o0
 //
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind15Registers_sparc6jumptoEv)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind15Registers_sparc6jumptoEv)
   ta 3
   ldd [%o0 + 64],  %l0
   ldd [%o0 + 72],  %l2
   ldd [%o0 + 80],  %l4
   ldd [%o0 + 88],  %l6
   ldd [%o0 + 96],  %i0
   ldd [%o0 + 104], %i2
   ldd [%o0 + 112], %i4

libunwind/src/UnwindRegistersSave.S

#include "assembly.h"
 
     .text
 
 #if !defined(__USING_SJLJ_EXCEPTIONS__)
 
 #if defined(__i386__)
 
 #
-# extern int unw_getcontext(unw_context_t* thread_state)
+# extern int __unw_getcontext(unw_context_t* thread_state)
 #
 # On entry:
 #   +                       +
 #   +-----------------------+
 #   + thread_state pointer  +
 #   +-----------------------+
 #   + return address        +
 #   +-----------------------+   <-- SP
 #   +                       +
 #
-DEFINE_LIBUNWIND_FUNCTION(unw_getcontext)
+DEFINE_LIBUNWIND_FUNCTION(__unw_getcontext)
   push  %eax
   movl  8(%esp), %eax
   movl  %ebx,  4(%eax)
   movl  %ecx,  8(%eax)
   movl  %edx, 12(%eax)
   movl  %edi, 16(%eax)
   movl  %esi, 20(%eax)
   movl  %ebp, 24(%eax)
DEFINE_LIBUNWIND_FUNCTION(__unw_getcontext)
   movl  %edx, (%eax)  # store original eax
   popl  %eax
   xorl  %eax, %eax    # return UNW_ESUCCESS
   ret
 
 #elif defined(__x86_64__)
 
 #
-# extern int unw_getcontext(unw_context_t* thread_state)
+# extern int __unw_getcontext(unw_context_t* thread_state)
 #
 # On entry:
 #  thread_state pointer is in rdi
 #
-DEFINE_LIBUNWIND_FUNCTION(unw_getcontext)
+DEFINE_LIBUNWIND_FUNCTION(__unw_getcontext)
 #if defined(_WIN64)
 #define PTR %rcx
 #define TMP %rdx
 #else
 #define PTR %rdi
 #define TMP %rsi
 #endif
 
#if defined(_WIN64)
   movdqu %xmm15,416(PTR)
 #endif
   xorl  %eax, %eax    # return UNW_ESUCCESS
   ret
 
 #elif defined(__mips__) && defined(_ABIO32) && _MIPS_SIM == _ABIO32
 
 #
-# extern int unw_getcontext(unw_context_t* thread_state)
+# extern int __unw_getcontext(unw_context_t* thread_state)
 #
 # On entry:
 #  thread_state pointer is in a0 ($4)
 #
-DEFINE_LIBUNWIND_FUNCTION(unw_getcontext)
+DEFINE_LIBUNWIND_FUNCTION(__unw_getcontext)
   .set push
   .set noat
   .set noreorder
   .set nomacro
   sw    $1, (4 * 1)($4)
   sw    $2, (4 * 2)($4)
   sw    $3, (4 * 3)($4)
   sw    $4, (4 * 4)($4)
#endif
   jr  $31
   # return UNW_ESUCCESS
   or    $2, $0, $0
   .set pop
 
 #elif defined(__mips64)
 
 #
-# extern int unw_getcontext(unw_context_t* thread_state)
+# extern int __unw_getcontext(unw_context_t* thread_state)
 #
 # On entry:
 #  thread_state pointer is in a0 ($4)
 #
-DEFINE_LIBUNWIND_FUNCTION(unw_getcontext)
+DEFINE_LIBUNWIND_FUNCTION(__unw_getcontext)
   .set push
   .set noat
   .set noreorder
   .set nomacro
   sd    $1, (8 * 1)($4)
   sd    $2, (8 * 2)($4)
   sd    $3, (8 * 3)($4)
   sd    $4, (8 * 4)($4)
#endif
   jr  $31
   # return UNW_ESUCCESS
   or    $2, $0, $0
   .set pop
 
 # elif defined(__mips__)
 
 #
-# extern int unw_getcontext(unw_context_t* thread_state)
+# extern int __unw_getcontext(unw_context_t* thread_state)
 #
 # Just trap for the time being.
-DEFINE_LIBUNWIND_FUNCTION(unw_getcontext)
+DEFINE_LIBUNWIND_FUNCTION(__unw_getcontext)
   teq $0, $0
 
 #elif defined(__powerpc64__)
 
 //
-// extern int unw_getcontext(unw_context_t* thread_state)
+// extern int __unw_getcontext(unw_context_t* thread_state)
 //
 // On entry:
 //  thread_state pointer is in r3
 //
-DEFINE_LIBUNWIND_FUNCTION(unw_getcontext)
+DEFINE_LIBUNWIND_FUNCTION(__unw_getcontext)
 
 // store register (GPR)
 #define PPC64_STR(n) \
   std   %r##n, (8 * (n + 2))(%r3)
 
   // save GPRs
   PPC64_STR(0)
   mflr  %r0
#endif
 
   li    %r3,  0   // return UNW_ESUCCESS
   blr
 
 
 #elif defined(__ppc__)
 
 ;
-; extern int unw_getcontext(unw_context_t* thread_state)
+; extern int __unw_getcontext(unw_context_t* thread_state)
 ;
 ; On entry:
 ;  thread_state pointer is in r3
 ;
-DEFINE_LIBUNWIND_FUNCTION(unw_getcontext)
+DEFINE_LIBUNWIND_FUNCTION(__unw_getcontext)
   stw    r0,  8(r3)
   mflr  r0
   stw    r0,  0(r3)  ; store lr as ssr0
   stw    r1, 12(r3)
   stw    r2, 16(r3)
   stw    r3, 20(r3)
   stw    r4, 24(r3)
   stw    r5, 28(r3)
#define SAVE_VECTOR_UNALIGNED(_vec, _offset) \
 
   li  r3, 0    ; return UNW_ESUCCESS
   blr
 
 
 #elif defined(__arm64__) || defined(__aarch64__)
 
 //
-// extern int unw_getcontext(unw_context_t* thread_state)
+// extern int __unw_getcontext(unw_context_t* thread_state)
 //
 // On entry:
 //  thread_state pointer is in x0
 //
   .p2align 2
-DEFINE_LIBUNWIND_FUNCTION(unw_getcontext)
+DEFINE_LIBUNWIND_FUNCTION(__unw_getcontext)
   stp    x0, x1,  [x0, #0x000]
   stp    x2, x3,  [x0, #0x010]
   stp    x4, x5,  [x0, #0x020]
   stp    x6, x7,  [x0, #0x030]
   stp    x8, x9,  [x0, #0x040]
   stp    x10,x11, [x0, #0x050]
   stp    x12,x13, [x0, #0x060]
   stp    x14,x15, [x0, #0x070]

 
 #elif defined(__arm__) && !defined(__APPLE__)
 
 #if !defined(__ARM_ARCH_ISA_ARM)
   .thumb
 #endif
 
 @
-@ extern int unw_getcontext(unw_context_t* thread_state)
+@ extern int __unw_getcontext(unw_context_t* thread_state)
 @
 @ On entry:
 @  thread_state pointer is in r0
 @ 
 @ Per EHABI #4.7 this only saves the core integer registers.
 @ EHABI #7.4.5 notes that in general all VRS registers should be restored
 @ however this is very hard to do for VFP registers because it is unknown
 @ to the library how many registers are implemented by the architecture.
-@ Instead, VFP registers are demand saved by logic external to unw_getcontext.
+@ Instead, VFP registers are demand saved by logic external to __unw_getcontext.
 @
   .p2align 2
-DEFINE_LIBUNWIND_FUNCTION(unw_getcontext)
+DEFINE_LIBUNWIND_FUNCTION(__unw_getcontext)
 #if !defined(__ARM_ARCH_ISA_ARM) && __ARM_ARCH_ISA_THUMB == 1
   stm r0!, {r0-r7}
   mov r1, r8
   mov r2, r9
   mov r3, r10
   stm r0!, {r1-r3}
   mov r1, r11
   mov r2, sp

 @
 @ On entry:
 @  values pointer is in r0
 @
   .p2align 2
 #if defined(__ELF__)
   .fpu vfpv3-d16
 #endif
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind13Registers_arm16saveVFPWithFSTMDEPv)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind13Registers_arm16saveVFPWithFSTMDEPv)
   vstmia r0, {d0-d15}
   JMP(lr)
 
 @
 @ static void libunwind::Registers_arm::saveVFPWithFSTMX(unw_fpreg_t* values)
 @
 @ On entry:
 @  values pointer is in r0
 @
   .p2align 2
 #if defined(__ELF__)
   .fpu vfpv3-d16
 #endif
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind13Registers_arm16saveVFPWithFSTMXEPv)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind13Registers_arm16saveVFPWithFSTMXEPv)
   vstmia r0, {d0-d15} @ fstmiax is deprecated in ARMv7+ and now behaves like vstmia
   JMP(lr)
 
 @
 @ static void libunwind::Registers_arm::saveVFPv3(unw_fpreg_t* values)
 @
 @ On entry:
 @  values pointer is in r0
 @
   .p2align 2
 #if defined(__ELF__)
   .fpu vfpv3
 #endif
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind13Registers_arm9saveVFPv3EPv)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind13Registers_arm9saveVFPv3EPv)
   @ VFP and iwMMX instructions are only available when compiling with the flags
   @ that enable them. We do not want to do that in the library (because we do not
   @ want the compiler to generate instructions that access those) but this is
   @ only accessed if the personality routine needs these registers. Use of
   @ these registers implies they are, actually, available on the target, so
   @ it's ok to execute.
   @ So, generate the instructions using the corresponding coprocessor mnemonic.
   vstmia r0, {d16-d31}
   JMP(lr)
 
 #if defined(_LIBUNWIND_ARM_WMMX)
 
 @
 @ static void libunwind::Registers_arm::saveiWMMX(unw_fpreg_t* values)
 @
 @ On entry:
 @  values pointer is in r0
 @
   .p2align 2
 #if defined(__ELF__)
   .arch armv5te
 #endif
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind13Registers_arm9saveiWMMXEPv)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind13Registers_arm9saveiWMMXEPv)
   stcl p1, cr0, [r0], #8  @ wstrd wR0, [r0], #8
   stcl p1, cr1, [r0], #8  @ wstrd wR1, [r0], #8
   stcl p1, cr2, [r0], #8  @ wstrd wR2, [r0], #8
   stcl p1, cr3, [r0], #8  @ wstrd wR3, [r0], #8
   stcl p1, cr4, [r0], #8  @ wstrd wR4, [r0], #8
   stcl p1, cr5, [r0], #8  @ wstrd wR5, [r0], #8
   stcl p1, cr6, [r0], #8  @ wstrd wR6, [r0], #8
   stcl p1, cr7, [r0], #8  @ wstrd wR7, [r0], #8

 @
 @ On entry:
 @  values pointer is in r0
 @
   .p2align 2
 #if defined(__ELF__)
   .arch armv5te
 #endif
-DEFINE_LIBUNWIND_PRIVATE_FUNCTION(_ZN9libunwind13Registers_arm16saveiWMMXControlEPj)
+DEFINE_LIBUNWIND_FUNCTION(_ZN9libunwind13Registers_arm16saveiWMMXControlEPj)
   stc2 p1, cr8, [r0], #4  @ wstrw wCGR0, [r0], #4
   stc2 p1, cr9, [r0], #4  @ wstrw wCGR1, [r0], #4
   stc2 p1, cr10, [r0], #4  @ wstrw wCGR2, [r0], #4
   stc2 p1, cr11, [r0], #4  @ wstrw wCGR3, [r0], #4
   JMP(lr)
 
 #endif
 
 #elif defined(__or1k__)
 
 #
-# extern int unw_getcontext(unw_context_t* thread_state)
+# extern int __unw_getcontext(unw_context_t* thread_state)
 #
 # On entry:
 #  thread_state pointer is in r3
 #
-DEFINE_LIBUNWIND_FUNCTION(unw_getcontext)
+DEFINE_LIBUNWIND_FUNCTION(__unw_getcontext)
   l.sw       0(r3), r0
   l.sw       4(r3), r1
   l.sw       8(r3), r2
   l.sw      12(r3), r3
   l.sw      16(r3), r4
   l.sw      20(r3), r5
   l.sw      24(r3), r6
   l.sw      28(r3), r7
DEFINE_LIBUNWIND_FUNCTION(__unw_getcontext)
   # store ra to pc
   l.sw     128(r3), r9
   # zero epcr
   l.sw     132(r3), r0
 
 #elif defined(__sparc__)
 
 #
-# extern int unw_getcontext(unw_context_t* thread_state)
+# extern int __unw_getcontext(unw_context_t* thread_state)
 #
 # On entry:
 #  thread_state pointer is in o0
 #
-DEFINE_LIBUNWIND_FUNCTION(unw_getcontext)
+DEFINE_LIBUNWIND_FUNCTION(__unw_getcontext)
   ta 3
   add %o7, 8, %o7
   std %g0, [%o0 +   0]
   std %g2, [%o0 +   8]
   std %g4, [%o0 +  16]
   std %g6, [%o0 +  24]
   std %o0, [%o0 +  32]
   std %o2, [%o0 +  40]
   std %o4, [%o0 +  48]
   std %o6, [%o0 +  56]
   std %l0, [%o0 +  64]
   std %l2, [%o0 +  72]
   std %l4, [%o0 +  80]
   std %l6, [%o0 +  88]
   std %i0, [%o0 +  96]
   std %i2, [%o0 + 104]
   std %i4, [%o0 + 112]
   std %i6, [%o0 + 120]
   jmp %o7
    clr %o0                   // return UNW_ESUCCESS
 #endif
 #endif /* !defined(__USING_SJLJ_EXCEPTIONS__) */
 
+  WEAK_ALIAS(__unw_getcontext, unw_getcontext)
+
 NO_EXEC_STACK_DIRECTIVE

libunwind/src/assembly.h

 #define GLUE(a, b) GLUE2(a, b)
 #define SYMBOL_NAME(name) GLUE(__USER_LABEL_PREFIX__, name)
 
 #if defined(__APPLE__)
 
 #define SYMBOL_IS_FUNC(name)
 #define EXPORT_SYMBOL(name)
 #define HIDDEN_SYMBOL(name) .private_extern name
+#define WEAK_SYMBOL(name) .weak_reference name
+#define WEAK_ALIAS(name, aliasname)                                            \
+  WEAK_SYMBOL(aliasname) SEPARATOR                                             \
+  SYMBOL_NAME(aliasname) = SYMBOL_NAME(name)
+
 #define NO_EXEC_STACK_DIRECTIVE
 
 #elif defined(__ELF__)
 
 #if defined(__arm__)
 #define SYMBOL_IS_FUNC(name) .type name,%function
 #else
 #define SYMBOL_IS_FUNC(name) .type name,@function
 #endif
 #define EXPORT_SYMBOL(name)
 #define HIDDEN_SYMBOL(name) .hidden name
+#define WEAK_SYMBOL(name) .weak name
+#define WEAK_ALIAS(name, aliasname)                                            \
+  WEAK_SYMBOL(aliasname) SEPARATOR                                             \
+  SYMBOL_NAME(aliasname) = SYMBOL_NAME(name)
 
 #if defined(__GNU__) || defined(__FreeBSD__) || defined(__Fuchsia__) || \
     defined(__linux__)
 #define NO_EXEC_STACK_DIRECTIVE .section .note.GNU-stack,"",%progbits
 #else
 #define NO_EXEC_STACK_DIRECTIVE
 #endif
 
 #elif defined(_WIN32)
 
 #define SYMBOL_IS_FUNC(name)                                                   \
   .def name SEPARATOR                                                          \
     .scl 2 SEPARATOR                                                           \
     .type 32 SEPARATOR                                                         \
   .endef
-#define EXPORT_SYMBOL2(name)                              \
-  .section .drectve,"yn" SEPARATOR                        \
-  .ascii "-export:", #name, "\0" SEPARATOR                \
+#define EXPORT_SYMBOL2(name)                                                   \
+  .section .drectve,"yn" SEPARATOR                                             \
+  .ascii "-export:", #name, "\0" SEPARATOR                                     \
   .text
 #if defined(_LIBUNWIND_DISABLE_VISIBILITY_ANNOTATIONS)
 #define EXPORT_SYMBOL(name)
 #else
 #define EXPORT_SYMBOL(name) EXPORT_SYMBOL2(name)
 #endif
 #define HIDDEN_SYMBOL(name)
 
+#if defined(__MINGW32__)
+#define WEAK_ALIAS(name, aliasname)                                            \
+  SYMBOL_NAME(aliasname) = SYMBOL_NAME(name)
+#else
+#define WEAK_ALIAS(name, aliasname)                                            \
+  .section .drectve,"yn" SEPARATOR                                             \
+  .ascii "-alternatename:", SYMBOL_NAME(aliasname), "=",                       \
+                            SYMBOL_NAME(name), "\0" SEPARATOR                  \
+  .text
+#endif
+
 #define NO_EXEC_STACK_DIRECTIVE
 
 #elif defined(__sparc__)
 
 #else
 
 #error Unsupported target
 
 #endif
 
-#define DEFINE_LIBUNWIND_FUNCTION(name)                   \
-  .globl SYMBOL_NAME(name) SEPARATOR                      \
-  EXPORT_SYMBOL(name) SEPARATOR                           \
-  SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR             \
-  SYMBOL_NAME(name):
-
-#define DEFINE_LIBUNWIND_PRIVATE_FUNCTION(name)           \
-  .globl SYMBOL_NAME(name) SEPARATOR                      \
-  HIDDEN_SYMBOL(SYMBOL_NAME(name)) SEPARATOR              \
-  SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR             \
+#define DEFINE_LIBUNWIND_FUNCTION(name)                                        \
+  .globl SYMBOL_NAME(name) SEPARATOR                                           \
+  HIDDEN_SYMBOL(SYMBOL_NAME(name)) SEPARATOR                                   \
+  SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
   SYMBOL_NAME(name):
 
 #if defined(__arm__)
 #if !defined(__ARM_ARCH)
 #define __ARM_ARCH 4
 #endif
 
 #if defined(__ARM_ARCH_4T__) || __ARM_ARCH >= 5

libunwind/src/config.h

#if !defined(__ELF__) && !defined(__MACH__)
     #define _LIBUNWIND_EXPORT __declspec(dllexport)
     #define _LIBUNWIND_HIDDEN
   #else
     #define _LIBUNWIND_EXPORT __attribute__((visibility("default")))
     #define _LIBUNWIND_HIDDEN __attribute__((visibility("hidden")))
   #endif
 #endif
 
+#define STR(a) #a
+#define XSTR(a) STR(a)
+#define SYMBOL_NAME(name) XSTR(__USER_LABEL_PREFIX__) #name
+
+#if defined(__APPLE__)
+#define _LIBUNWIND_WEAK_ALIAS(name, aliasname)                                 \
+  __asm__(".globl " SYMBOL_NAME(aliasname));                                   \
+  __asm__(SYMBOL_NAME(aliasname) " = " SYMBOL_NAME(name));                     \
+  _LIBUNWIND_EXPORT                                                            \
+  extern "C" __typeof(name) aliasname __attribute__((weak_import));
+#elif defined(__ELF__)
+#define _LIBUNWIND_WEAK_ALIAS(name, aliasname)                                 \
+  _LIBUNWIND_EXPORT                                                            \
+  extern "C" __typeof(name) aliasname __attribute__((weak, alias(#name)));
+#elif defined(_WIN32)
+#if defined(__MINGW32__)
+#define _LIBUNWIND_WEAK_ALIAS(name, aliasname)                                 \
+  _LIBUNWIND_EXPORT                                                            \
+  extern "C" __typeof(name) aliasname __attribute__((alias(#name)));
+#else
+#define _LIBUNWIND_WEAK_ALIAS(name, aliasname)                                 \
+  __pragma(comment(linker, "/alternatename:" SYMBOL_NAME(aliasname) "="        \
+                                             SYMBOL_NAME(name)))               \
+  _LIBUNWIND_EXPORT \
+  extern "C" __typeof(name) aliasname;
+#endif
+#else
+#error Unsupported target
+#endif
+
 #if (defined(__APPLE__) && defined(__arm__)) || defined(__USING_SJLJ_EXCEPTIONS__)
 #define _LIBUNWIND_BUILD_SJLJ_APIS
 #endif
 
 #if defined(__i386__) || defined(__x86_64__) || defined(__ppc__) || defined(__ppc64__) || defined(__powerpc64__)
 #define _LIBUNWIND_SUPPORT_FRAME_APIS
 #endif
 

libunwind/src/libunwind.cpp

 using namespace libunwind;
 
 /// internal object to represent this processes address space
 LocalAddressSpace LocalAddressSpace::sThisAddressSpace;
 
 _LIBUNWIND_EXPORT unw_addr_space_t unw_local_addr_space =
     (unw_addr_space_t)&LocalAddressSpace::sThisAddressSpace;
 
-/// record the registers and stack position of the caller
-extern int unw_getcontext(unw_context_t *);
-// note: unw_getcontext() implemented in assembly
-
 /// Create a cursor of a thread in this process given 'context' recorded by
-/// unw_getcontext().
-_LIBUNWIND_EXPORT int unw_init_local(unw_cursor_t *cursor,
+/// __unw_getcontext().
+_LIBUNWIND_HIDDEN int __unw_init_local(unw_cursor_t *cursor,
                                        unw_context_t *context) {
-  _LIBUNWIND_TRACE_API("unw_init_local(cursor=%p, context=%p)",
+  _LIBUNWIND_TRACE_API("__unw_init_local(cursor=%p, context=%p)",
                        static_cast<void *>(cursor),
                        static_cast<void *>(context));
 #if defined(__i386__)
 # define REGISTER_KIND Registers_x86
 #elif defined(__x86_64__)
 # define REGISTER_KIND Registers_x86_64
 #elif defined(__powerpc64__)
 # define REGISTER_KIND Registers_ppc64
new (reinterpret_cast<UnwindCursor<LocalAddressSpace, REGISTER_KIND> *>(cursor))
       UnwindCursor<LocalAddressSpace, REGISTER_KIND>(
           context, LocalAddressSpace::sThisAddressSpace);
 #undef REGISTER_KIND
   AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
   co->setInfoBasedOnIPRegister();
 
   return UNW_ESUCCESS;
 }
+_LIBUNWIND_WEAK_ALIAS(__unw_init_local, unw_init_local)
 
 /// Get value of specified register at cursor position in stack frame.
-_LIBUNWIND_EXPORT int unw_get_reg(unw_cursor_t *cursor, unw_regnum_t regNum,
+_LIBUNWIND_HIDDEN int __unw_get_reg(unw_cursor_t *cursor, unw_regnum_t regNum,
                                     unw_word_t *value) {
-  _LIBUNWIND_TRACE_API("unw_get_reg(cursor=%p, regNum=%d, &value=%p)",
+  _LIBUNWIND_TRACE_API("__unw_get_reg(cursor=%p, regNum=%d, &value=%p)",
                        static_cast<void *>(cursor), regNum,
                        static_cast<void *>(value));
   AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
   if (co->validReg(regNum)) {
     *value = co->getReg(regNum);
     return UNW_ESUCCESS;
   }
   return UNW_EBADREG;
 }
-
+_LIBUNWIND_WEAK_ALIAS(__unw_get_reg, unw_get_reg)
 
 /// Set value of specified register at cursor position in stack frame.
-_LIBUNWIND_EXPORT int unw_set_reg(unw_cursor_t *cursor, unw_regnum_t regNum,
+_LIBUNWIND_HIDDEN int __unw_set_reg(unw_cursor_t *cursor, unw_regnum_t regNum,
                                     unw_word_t value) {
-  _LIBUNWIND_TRACE_API("unw_set_reg(cursor=%p, regNum=%d, value=0x%" PRIxPTR ")",
+  _LIBUNWIND_TRACE_API("__unw_set_reg(cursor=%p, regNum=%d, value=0x%" PRIxPTR
+                       ")",
                        static_cast<void *>(cursor), regNum, value);
   typedef LocalAddressSpace::pint_t pint_t;
   AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
   if (co->validReg(regNum)) {
     co->setReg(regNum, (pint_t)value);
     // specical case altering IP to re-find info (being called by personality
     // function)
     if (regNum == UNW_REG_IP) {
if (regNum == UNW_REG_IP) {
       // any such platforms and Clang doesn't export a macro for them.
       if (info.gp)
         co->setReg(UNW_REG_SP, co->getReg(UNW_REG_SP) + info.gp);
     }
     return UNW_ESUCCESS;
   }
   return UNW_EBADREG;
 }
-
+_LIBUNWIND_WEAK_ALIAS(__unw_set_reg, unw_set_reg)
 
 /// Get value of specified float register at cursor position in stack frame.
-_LIBUNWIND_EXPORT int unw_get_fpreg(unw_cursor_t *cursor, unw_regnum_t regNum,
+_LIBUNWIND_HIDDEN int __unw_get_fpreg(unw_cursor_t *cursor, unw_regnum_t regNum,
                                       unw_fpreg_t *value) {
-  _LIBUNWIND_TRACE_API("unw_get_fpreg(cursor=%p, regNum=%d, &value=%p)",
+  _LIBUNWIND_TRACE_API("__unw_get_fpreg(cursor=%p, regNum=%d, &value=%p)",
                        static_cast<void *>(cursor), regNum,
                        static_cast<void *>(value));
   AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
   if (co->validFloatReg(regNum)) {
     *value = co->getFloatReg(regNum);
     return UNW_ESUCCESS;
   }
   return UNW_EBADREG;
 }
-
+_LIBUNWIND_WEAK_ALIAS(__unw_get_fpreg, unw_get_fpreg)
 
 /// Set value of specified float register at cursor position in stack frame.
-_LIBUNWIND_EXPORT int unw_set_fpreg(unw_cursor_t *cursor, unw_regnum_t regNum,
+_LIBUNWIND_HIDDEN int __unw_set_fpreg(unw_cursor_t *cursor, unw_regnum_t regNum,
                                       unw_fpreg_t value) {
 #if defined(_LIBUNWIND_ARM_EHABI)
-  _LIBUNWIND_TRACE_API("unw_set_fpreg(cursor=%p, regNum=%d, value=%llX)",
+  _LIBUNWIND_TRACE_API("__unw_set_fpreg(cursor=%p, regNum=%d, value=%llX)",
                        static_cast<void *>(cursor), regNum, value);
 #else
-  _LIBUNWIND_TRACE_API("unw_set_fpreg(cursor=%p, regNum=%d, value=%g)",
+  _LIBUNWIND_TRACE_API("__unw_set_fpreg(cursor=%p, regNum=%d, value=%g)",
                        static_cast<void *>(cursor), regNum, value);
 #endif
   AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
   if (co->validFloatReg(regNum)) {
     co->setFloatReg(regNum, value);
     return UNW_ESUCCESS;
   }
   return UNW_EBADREG;
 }
-
+_LIBUNWIND_WEAK_ALIAS(__unw_set_fpreg, unw_set_fpreg)
 
 /// Move cursor to next frame.
-_LIBUNWIND_EXPORT int unw_step(unw_cursor_t *cursor) {
-  _LIBUNWIND_TRACE_API("unw_step(cursor=%p)", static_cast<void *>(cursor));
+_LIBUNWIND_HIDDEN int __unw_step(unw_cursor_t *cursor) {
+  _LIBUNWIND_TRACE_API("__unw_step(cursor=%p)", static_cast<void *>(cursor));
   AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
   return co->step();
 }
-
+_LIBUNWIND_WEAK_ALIAS(__unw_step, unw_step)
 
 /// Get unwind info at cursor position in stack frame.
-_LIBUNWIND_EXPORT int unw_get_proc_info(unw_cursor_t *cursor,
+_LIBUNWIND_HIDDEN int __unw_get_proc_info(unw_cursor_t *cursor,
                                           unw_proc_info_t *info) {
-  _LIBUNWIND_TRACE_API("unw_get_proc_info(cursor=%p, &info=%p)",
+  _LIBUNWIND_TRACE_API("__unw_get_proc_info(cursor=%p, &info=%p)",
                        static_cast<void *>(cursor), static_cast<void *>(info));
   AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
   co->getInfo(info);
   if (info->end_ip == 0)
     return UNW_ENOINFO;
   else
     return UNW_ESUCCESS;
 }
-
+_LIBUNWIND_WEAK_ALIAS(__unw_get_proc_info, unw_get_proc_info)
 
 /// Resume execution at cursor position (aka longjump).
-_LIBUNWIND_EXPORT int unw_resume(unw_cursor_t *cursor) {
-  _LIBUNWIND_TRACE_API("unw_resume(cursor=%p)", static_cast<void *>(cursor));
+_LIBUNWIND_HIDDEN int __unw_resume(unw_cursor_t *cursor) {
+  _LIBUNWIND_TRACE_API("__unw_resume(cursor=%p)", static_cast<void *>(cursor));
   AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
   co->jumpto();
   return UNW_EUNSPEC;
 }
-
+_LIBUNWIND_WEAK_ALIAS(__unw_resume, unw_resume)
 
 /// Get name of function at cursor position in stack frame.
-_LIBUNWIND_EXPORT int unw_get_proc_name(unw_cursor_t *cursor, char *buf,
+_LIBUNWIND_HIDDEN int __unw_get_proc_name(unw_cursor_t *cursor, char *buf,
                                           size_t bufLen, unw_word_t *offset) {
-  _LIBUNWIND_TRACE_API("unw_get_proc_name(cursor=%p, &buf=%p, bufLen=%lu)",
+  _LIBUNWIND_TRACE_API("__unw_get_proc_name(cursor=%p, &buf=%p, bufLen=%lu)",
                        static_cast<void *>(cursor), static_cast<void *>(buf),
                        static_cast<unsigned long>(bufLen));
   AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
   if (co->getFunctionName(buf, bufLen, offset))
     return UNW_ESUCCESS;
   else
     return UNW_EUNSPEC;
 }
-
+_LIBUNWIND_WEAK_ALIAS(__unw_get_proc_name, unw_get_proc_name)
 
 /// Checks if a register is a floating-point register.
-_LIBUNWIND_EXPORT int unw_is_fpreg(unw_cursor_t *cursor, unw_regnum_t regNum) {
-  _LIBUNWIND_TRACE_API("unw_is_fpreg(cursor=%p, regNum=%d)",
+_LIBUNWIND_HIDDEN int __unw_is_fpreg(unw_cursor_t *cursor,
+                                     unw_regnum_t regNum) {
+  _LIBUNWIND_TRACE_API("__unw_is_fpreg(cursor=%p, regNum=%d)",
                        static_cast<void *>(cursor), regNum);
   AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
   return co->validFloatReg(regNum);
 }
-
+_LIBUNWIND_WEAK_ALIAS(__unw_is_fpreg, unw_is_fpreg)
 
 /// Checks if a register is a floating-point register.
-_LIBUNWIND_EXPORT const char *unw_regname(unw_cursor_t *cursor,
+_LIBUNWIND_HIDDEN const char *__unw_regname(unw_cursor_t *cursor,
                                             unw_regnum_t regNum) {
-  _LIBUNWIND_TRACE_API("unw_regname(cursor=%p, regNum=%d)",
+  _LIBUNWIND_TRACE_API("__unw_regname(cursor=%p, regNum=%d)",
                        static_cast<void *>(cursor), regNum);
   AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
   return co->getRegisterName(regNum);
 }
-
+_LIBUNWIND_WEAK_ALIAS(__unw_regname, unw_regname)
 
 /// Checks if current frame is signal trampoline.
-_LIBUNWIND_EXPORT int unw_is_signal_frame(unw_cursor_t *cursor) {
-  _LIBUNWIND_TRACE_API("unw_is_signal_frame(cursor=%p)",
+_LIBUNWIND_HIDDEN int __unw_is_signal_frame(unw_cursor_t *cursor) {
+  _LIBUNWIND_TRACE_API("__unw_is_signal_frame(cursor=%p)",
                        static_cast<void *>(cursor));
   AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
   return co->isSignalFrame();
 }
+_LIBUNWIND_WEAK_ALIAS(__unw_is_signal_frame, unw_is_signal_frame)
 
 #ifdef __arm__
 // Save VFP registers d0-d15 using FSTMIADX instead of FSTMIADD
-_LIBUNWIND_EXPORT void unw_save_vfp_as_X(unw_cursor_t *cursor) {
-  _LIBUNWIND_TRACE_API("unw_fpreg_save_vfp_as_X(cursor=%p)",
+_LIBUNWIND_HIDDEN void __unw_save_vfp_as_X(unw_cursor_t *cursor) {
+  _LIBUNWIND_TRACE_API("__unw_get_fpreg_save_vfp_as_X(cursor=%p)",
                        static_cast<void *>(cursor));
   AbstractUnwindCursor *co = (AbstractUnwindCursor *)cursor;
   return co->saveVFPAsX();
 }
+_LIBUNWIND_WEAK_ALIAS(__unw_save_vfp_as_X, unw_save_cfp_as_X)
 #endif
 
 
 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
 /// SPI: walks cached DWARF entries
-_LIBUNWIND_EXPORT void unw_iterate_dwarf_unwind_cache(void (*func)(
+_LIBUNWIND_HIDDEN void __unw_iterate_dwarf_unwind_cache(void (*func)(
     unw_word_t ip_start, unw_word_t ip_end, unw_word_t fde, unw_word_t mh)) {
-  _LIBUNWIND_TRACE_API("unw_iterate_dwarf_unwind_cache(func=%p)",
+  _LIBUNWIND_TRACE_API("__unw_iterate_dwarf_unwind_cache(func=%p)",
                        reinterpret_cast<void *>(func));
   DwarfFDECache<LocalAddressSpace>::iterateCacheEntries(func);
 }
-
+_LIBUNWIND_WEAK_ALIAS(__unw_iterate_dwarf_unwind_cache,
+                      unw_iterate_dwarf_unwind_cache)
 
 /// IPI: for __register_frame()
-void _unw_add_dynamic_fde(unw_word_t fde) {
+void __unw_add_dynamic_fde(unw_word_t fde) {
   CFI_Parser<LocalAddressSpace>::FDE_Info fdeInfo;
   CFI_Parser<LocalAddressSpace>::CIE_Info cieInfo;
   const char *message = CFI_Parser<LocalAddressSpace>::decodeFDE(
                            LocalAddressSpace::sThisAddressSpace,
                           (LocalAddressSpace::pint_t) fde, &fdeInfo, &cieInfo);
   if (message == NULL) {
     // dynamically registered FDEs don't have a mach_header group they are in.
     // Use fde as mh_group
     unw_word_t mh_group = fdeInfo.fdeStart;
     DwarfFDECache<LocalAddressSpace>::add((LocalAddressSpace::pint_t)mh_group,
                                           fdeInfo.pcStart, fdeInfo.pcEnd,
                                           fdeInfo.fdeStart);
   } else {
-    _LIBUNWIND_DEBUG_LOG("_unw_add_dynamic_fde: bad fde: %s", message);
+    _LIBUNWIND_DEBUG_LOG("__unw_add_dynamic_fde: bad fde: %s", message);
   }
 }
 
 /// IPI: for __deregister_frame()
-void _unw_remove_dynamic_fde(unw_word_t fde) {
+void __unw_remove_dynamic_fde(unw_word_t fde) {
   // fde is own mh_group
   DwarfFDECache<LocalAddressSpace>::removeAllIn((LocalAddressSpace::pint_t)fde);
 }
 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
 #endif // !defined(__USING_SJLJ_EXCEPTIONS__)
 
 
 

libunwind/src/libunwind_ext.h

 #include <unwind.h>
 
 #define UNW_STEP_SUCCESS 1
 #define UNW_STEP_END     0
 
 #ifdef __cplusplus
 extern "C" {
 #endif
+
+extern int __unw_getcontext(unw_context_t *);
+extern int __unw_init_local(unw_cursor_t *, unw_context_t *);
+extern int __unw_step(unw_cursor_t *);
+extern int __unw_get_reg(unw_cursor_t *, unw_regnum_t, unw_word_t *);
+extern int __unw_get_fpreg(unw_cursor_t *, unw_regnum_t, unw_fpreg_t *);
+extern int __unw_set_reg(unw_cursor_t *, unw_regnum_t, unw_word_t);
+extern int __unw_set_fpreg(unw_cursor_t *, unw_regnum_t, unw_fpreg_t);
+extern int __unw_resume(unw_cursor_t *);
+
+#ifdef __arm__
+/* Save VFP registers in FSTMX format (instead of FSTMD). */
+extern void __unw_save_vfp_as_X(unw_cursor_t *);
+#endif
+
+extern const char *__unw_regname(unw_cursor_t *, unw_regnum_t);
+extern int __unw_get_proc_info(unw_cursor_t *, unw_proc_info_t *);
+extern int __unw_is_fpreg(unw_cursor_t *, unw_regnum_t);
+extern int __unw_is_signal_frame(unw_cursor_t *);
+extern int __unw_get_proc_name(unw_cursor_t *, char *, size_t, unw_word_t *);
+
 // SPI
-extern void unw_iterate_dwarf_unwind_cache(void (*func)(unw_word_t ip_start,
-                                                        unw_word_t ip_end,
-                                                        unw_word_t fde,
-                                                        unw_word_t mh));
+extern void __unw_iterate_dwarf_unwind_cache(void (*func)(
+    unw_word_t ip_start, unw_word_t ip_end, unw_word_t fde, unw_word_t mh));
 
 // IPI
-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_fde(unw_word_t fde);
+extern void __unw_remove_dynamic_fde(unw_word_t fde);
 
 #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,
                                                  const uint32_t *data,
                                                  size_t offset, size_t len);
 #endif
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif // __LIBUNWIND_EXT__