diff --git a/compiler-rt/emscripten_tempret.s b/compiler-rt/emscripten_tempret.s
index 4e3b307a03e72..a098e33d15913 100644
--- a/compiler-rt/emscripten_tempret.s
+++ b/compiler-rt/emscripten_tempret.s
@@ -1,6 +1,10 @@
+.section .globals,"",@
+
 .globaltype tempRet0, i32
 tempRet0:
 
+.section .text,"",@
+
 .globl setTempRet0
 setTempRet0:
   .functype setTempRet0 (i32) -> ()
diff --git a/compiler-rt/stack_limits.S b/compiler-rt/stack_limits.S
index 1171afa8174fc..7bb9d895c46e8 100644
--- a/compiler-rt/stack_limits.S
+++ b/compiler-rt/stack_limits.S
@@ -16,6 +16,8 @@
 
 .globaltype __stack_pointer, PTR
 
+.section .globals,"",@
+
 # TODO(sbc): It would be nice if these we initialized directly
 # using PTR.const rather than using the `emscripten_stack_init`
 .globaltype __stack_end, PTR
@@ -23,6 +25,8 @@ __stack_end:
 .globaltype __stack_base, PTR
 __stack_base:
 
+.section .text,"",@
+
 emscripten_stack_get_base:
   .functype emscripten_stack_get_base () -> (PTR)
   global.get __stack_base
diff --git a/libcxxabi/include/cxxabi.h b/libcxxabi/include/cxxabi.h
index 3f79df260a495..6f4f823bc273f 100644
--- a/libcxxabi/include/cxxabi.h
+++ b/libcxxabi/include/cxxabi.h
@@ -40,14 +40,15 @@ extern "C"  {
 
 // 2.4.2 Allocating the Exception Object
 extern _LIBCXXABI_FUNC_VIS void *
-__cxa_allocate_exception(size_t thrown_size) _NOEXCEPT;
+__cxa_allocate_exception(size_t thrown_size) throw();
 extern _LIBCXXABI_FUNC_VIS void
-__cxa_free_exception(void *thrown_exception) _NOEXCEPT;
+__cxa_free_exception(void *thrown_exception) throw();
 
 // 2.4.3 Throwing the Exception Object
 extern _LIBCXXABI_FUNC_VIS _LIBCXXABI_NORETURN void
 __cxa_throw(void *thrown_exception, std::type_info *tinfo,
 #ifdef __USING_WASM_EXCEPTIONS__
+            // In Wasm, a destructor returns its argument
             void *(_LIBCXXABI_DTOR_FUNC *dest)(void *));
 #else
             void (_LIBCXXABI_DTOR_FUNC *dest)(void *));
@@ -55,9 +56,9 @@ __cxa_throw(void *thrown_exception, std::type_info *tinfo,
 
 // 2.5.3 Exception Handlers
 extern _LIBCXXABI_FUNC_VIS void *
-__cxa_get_exception_ptr(void *exceptionObject) _NOEXCEPT;
+__cxa_get_exception_ptr(void *exceptionObject) throw();
 extern _LIBCXXABI_FUNC_VIS void *
-__cxa_begin_catch(void *exceptionObject) _NOEXCEPT;
+__cxa_begin_catch(void *exceptionObject) throw();
 extern _LIBCXXABI_FUNC_VIS void __cxa_end_catch();
 #if defined(_LIBCXXABI_ARM_EHABI)
 extern _LIBCXXABI_FUNC_VIS bool
@@ -152,17 +153,17 @@ extern _LIBCXXABI_FUNC_VIS char *__cxa_demangle(const char *mangled_name,
 
 // Apple additions to support C++ 0x exception_ptr class
 // These are primitives to wrap a smart pointer around an exception object
-extern _LIBCXXABI_FUNC_VIS void *__cxa_current_primary_exception() _NOEXCEPT;
+extern _LIBCXXABI_FUNC_VIS void *__cxa_current_primary_exception() throw();
 extern _LIBCXXABI_FUNC_VIS void
 __cxa_rethrow_primary_exception(void *primary_exception);
 extern _LIBCXXABI_FUNC_VIS void
-__cxa_increment_exception_refcount(void *primary_exception) _NOEXCEPT;
+__cxa_increment_exception_refcount(void *primary_exception) throw();
 extern _LIBCXXABI_FUNC_VIS void
-__cxa_decrement_exception_refcount(void *primary_exception) _NOEXCEPT;
+__cxa_decrement_exception_refcount(void *primary_exception) throw();
 
 // Apple extension to support std::uncaught_exception()
-extern _LIBCXXABI_FUNC_VIS bool __cxa_uncaught_exception() _NOEXCEPT;
-extern _LIBCXXABI_FUNC_VIS unsigned int __cxa_uncaught_exceptions() _NOEXCEPT;
+extern _LIBCXXABI_FUNC_VIS bool __cxa_uncaught_exception() throw();
+extern _LIBCXXABI_FUNC_VIS unsigned int __cxa_uncaught_exceptions() throw();
 
 #if defined(__linux__) || defined(__Fuchsia__)
 // Linux and Fuchsia TLS support. Not yet an official part of the Itanium ABI.
diff --git a/libcxxabi/src/cxa_exception.cpp b/libcxxabi/src/cxa_exception.cpp
index 64f14c8c1a202..43537f159b22a 100644
--- a/libcxxabi/src/cxa_exception.cpp
+++ b/libcxxabi/src/cxa_exception.cpp
@@ -180,7 +180,7 @@ extern "C" {
 //  object. Zero-fill the object. If memory can't be allocated, call
 //  std::terminate. Return a pointer to the memory to be used for the
 //  user's exception object.
-void *__cxa_allocate_exception(size_t thrown_size) _NOEXCEPT {
+void *__cxa_allocate_exception(size_t thrown_size) throw() {
     size_t actual_size = cxa_exception_size_from_exception_thrown_size(thrown_size);
 
     // Allocate extra space before the __cxa_exception header to ensure the
@@ -198,7 +198,7 @@ void *__cxa_allocate_exception(size_t thrown_size) _NOEXCEPT {
 
 
 //  Free a __cxa_exception object allocated with __cxa_allocate_exception.
-void __cxa_free_exception(void *thrown_object) _NOEXCEPT {
+void __cxa_free_exception(void *thrown_object) throw() {
     // Compute the size of the padding before the header.
     size_t header_offset = get_cxa_exception_offset();
     char *raw_buffer =
@@ -254,7 +254,7 @@ will call terminate, assuming that there was no handler for the
 exception.
 */
 
-#if defined(__USING_WASM_EXCEPTIONS__) && !defined(NDEBUG)
+#if defined(__EMSCRIPTEN__) && defined(__USING_WASM_EXCEPTIONS__) && !defined(NDEBUG)
 extern "C" {
 void __throw_exception_with_stack_trace(_Unwind_Exception*);
 } // extern "C"
@@ -262,7 +262,7 @@ void __throw_exception_with_stack_trace(_Unwind_Exception*);
 
 void
 #ifdef __USING_WASM_EXCEPTIONS__
-// In wasm, destructors return their argument
+// In Wasm, a destructor returns its argument
 __cxa_throw(void *thrown_object, std::type_info *tinfo, void *(_LIBCXXABI_DTOR_FUNC *dest)(void *)) {
 #else
 __cxa_throw(void *thrown_object, std::type_info *tinfo, void (_LIBCXXABI_DTOR_FUNC *dest)(void *)) {
@@ -287,14 +287,10 @@ __cxa_throw(void *thrown_object, std::type_info *tinfo, void (_LIBCXXABI_DTOR_FU
 
 #ifdef __USING_SJLJ_EXCEPTIONS__
     _Unwind_SjLj_RaiseException(&exception_header->unwindHeader);
-#elif __USING_WASM_EXCEPTIONS__
-#ifdef NDEBUG
-    _Unwind_RaiseException(&exception_header->unwindHeader);
-#else
+#elif defined(__EMSCRIPTEN__) && defined(__USING_WASM_EXCEPTIONS__) && !defined(NDEBUG)
     // In debug mode, call a JS library function to use WebAssembly.Exception JS
     // API, which enables us to include stack traces
     __throw_exception_with_stack_trace(&exception_header->unwindHeader);
-#endif
 #else
     _Unwind_RaiseException(&exception_header->unwindHeader);
 #endif
@@ -312,7 +308,7 @@ The adjusted pointer is computed by the personality routine during phase 1
 
   Requires:  exception is native
 */
-void *__cxa_get_exception_ptr(void *unwind_exception) _NOEXCEPT {
+void *__cxa_get_exception_ptr(void *unwind_exception) throw() {
 #if defined(_LIBCXXABI_ARM_EHABI)
     return reinterpret_cast<void*>(
         static_cast<_Unwind_Control_Block*>(unwind_exception)->barrier_cache.bitpattern[0]);
@@ -327,7 +323,7 @@ void *__cxa_get_exception_ptr(void *unwind_exception) _NOEXCEPT {
 The routine to be called before the cleanup.  This will save __cxa_exception in
 __cxa_eh_globals, so that __cxa_end_cleanup() can recover later.
 */
-bool __cxa_begin_cleanup(void *unwind_arg) _NOEXCEPT {
+bool __cxa_begin_cleanup(void *unwind_arg) throw() {
     _Unwind_Exception* unwind_exception = static_cast<_Unwind_Exception*>(unwind_arg);
     __cxa_eh_globals* globals = __cxa_get_globals();
     __cxa_exception* exception_header =
@@ -451,7 +447,7 @@ to terminate or unexpected during unwinding.
   _Unwind_Exception and return a pointer to that.
 */
 void*
-__cxa_begin_catch(void* unwind_arg) _NOEXCEPT
+__cxa_begin_catch(void* unwind_arg) throw()
 {
     _Unwind_Exception* unwind_exception = static_cast<_Unwind_Exception*>(unwind_arg);
     bool native_exception = __isOurExceptionClass(unwind_exception);
@@ -644,6 +640,10 @@ void __cxa_rethrow() {
     }
 #ifdef __USING_SJLJ_EXCEPTIONS__
     _Unwind_SjLj_RaiseException(&exception_header->unwindHeader);
+#elif defined(__EMSCRIPTEN__) && defined(__USING_WASM_EXCEPTIONS__) && !defined(NDEBUG)
+    // In debug mode, call a JS library function to use WebAssembly.Exception JS
+    // API, which enables us to include stack traces
+    __throw_exception_with_stack_trace(&exception_header->unwindHeader);
 #else
     _Unwind_RaiseException(&exception_header->unwindHeader);
 #endif
@@ -667,7 +667,7 @@ void __cxa_rethrow() {
     Requires:  If thrown_object is not NULL, it is a native exception.
 */
 void
-__cxa_increment_exception_refcount(void *thrown_object) _NOEXCEPT {
+__cxa_increment_exception_refcount(void *thrown_object) throw() {
     if (thrown_object != NULL )
     {
         __cxa_exception* exception_header = cxa_exception_from_thrown_object(thrown_object);
@@ -684,7 +684,7 @@ __cxa_increment_exception_refcount(void *thrown_object) _NOEXCEPT {
     Requires:  If thrown_object is not NULL, it is a native exception.
 */
 _LIBCXXABI_NO_CFI
-void __cxa_decrement_exception_refcount(void *thrown_object) _NOEXCEPT {
+void __cxa_decrement_exception_refcount(void *thrown_object) throw() {
     if (thrown_object != NULL )
     {
         __cxa_exception* exception_header = cxa_exception_from_thrown_object(thrown_object);
@@ -707,7 +707,7 @@ void __cxa_decrement_exception_refcount(void *thrown_object) _NOEXCEPT {
     been no exceptions thrown, ever, on this thread, we can return NULL without
     the need to allocate the exception-handling globals.
 */
-void *__cxa_current_primary_exception() _NOEXCEPT {
+void *__cxa_current_primary_exception() throw() {
 //  get the current exception
     __cxa_eh_globals* globals = __cxa_get_globals_fast();
     if (NULL == globals)
@@ -769,8 +769,13 @@ __cxa_rethrow_primary_exception(void* thrown_object)
         dep_exception_header->unwindHeader.exception_cleanup = dependent_exception_cleanup;
 #ifdef __USING_SJLJ_EXCEPTIONS__
         _Unwind_SjLj_RaiseException(&dep_exception_header->unwindHeader);
+#elif defined(__EMSCRIPTEN__) && defined(__USING_WASM_EXCEPTIONS__) && !defined(NDEBUG)
+        // In debug mode, call a JS library function to use
+        // WebAssembly.Exception JS API, which enables us to include stack
+        // traces
+        __throw_exception_with_stack_trace(&exception_header->unwindHeader);
 #else
-        _Unwind_RaiseException(&dep_exception_header->unwindHeader);
+        _Unwind_RaiseException(&exception_header->unwindHeader);
 #endif
         // Some sort of unwinding error.  Note that terminate is a handler.
         __cxa_begin_catch(&dep_exception_header->unwindHeader);
@@ -779,10 +784,10 @@ __cxa_rethrow_primary_exception(void* thrown_object)
 }
 
 bool
-__cxa_uncaught_exception() _NOEXCEPT { return __cxa_uncaught_exceptions() != 0; }
+__cxa_uncaught_exception() throw() { return __cxa_uncaught_exceptions() != 0; }
 
 unsigned int
-__cxa_uncaught_exceptions() _NOEXCEPT
+__cxa_uncaught_exceptions() throw()
 {
     // This does not report foreign exceptions in flight
     __cxa_eh_globals* globals = __cxa_get_globals_fast();
diff --git a/libcxxabi/src/cxa_exception.h b/libcxxabi/src/cxa_exception.h
index 96f828d003239..098e0bf95aef8 100644
--- a/libcxxabi/src/cxa_exception.h
+++ b/libcxxabi/src/cxa_exception.h
@@ -64,7 +64,7 @@ struct _LIBCXXABI_HIDDEN __cxa_exception {
     //  Manage the exception object itself.
     std::type_info *exceptionType;
 #ifdef __USING_WASM_EXCEPTIONS__
-    // In wasm, destructors return their argument
+    // In Wasm, a destructor returns its argument
     void *(_LIBCXXABI_DTOR_FUNC *exceptionDestructor)(void *);
 #else
     void (_LIBCXXABI_DTOR_FUNC *exceptionDestructor)(void *);
diff --git a/libcxxabi/src/cxa_exception_emscripten.cpp b/libcxxabi/src/cxa_exception_emscripten.cpp
index fef9bf9a0e90d..a80e644da865e 100644
--- a/libcxxabi/src/cxa_exception_emscripten.cpp
+++ b/libcxxabi/src/cxa_exception_emscripten.cpp
@@ -11,6 +11,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+#ifdef __EMSCRIPTEN__
+
 #include "cxxabi.h"
 #include "cxa_exception.h"
 #include "include/atomic_support.h"
@@ -85,7 +87,7 @@ extern "C" {
 //  object. Zero-fill the object. If memory can't be allocated, call
 //  std::terminate. Return a pointer to the memory to be used for the
 //  user's exception object.
-void *__cxa_allocate_exception(size_t thrown_size) _NOEXCEPT {
+void *__cxa_allocate_exception(size_t thrown_size) throw() {
     size_t actual_size = cxa_exception_size_from_exception_thrown_size(thrown_size);
 
     char *raw_buffer =
@@ -100,7 +102,7 @@ void *__cxa_allocate_exception(size_t thrown_size) _NOEXCEPT {
 
 
 //  Free a __cxa_exception object allocated with __cxa_allocate_exception.
-void __cxa_free_exception(void *thrown_object) _NOEXCEPT {
+void __cxa_free_exception(void *thrown_object) throw() {
     // Compute the size of the padding before the header.
     char *raw_buffer =
         ((char *)cxa_exception_from_thrown_object(thrown_object));
@@ -115,7 +117,7 @@ void __cxa_free_exception(void *thrown_object) _NOEXCEPT {
     Requires:  If thrown_object is not NULL, it is a native exception.
 */
 void
-__cxa_increment_exception_refcount(void *thrown_object) _NOEXCEPT {
+__cxa_increment_exception_refcount(void *thrown_object) throw() {
     if (thrown_object != NULL )
     {
         __cxa_exception* exception_header = cxa_exception_from_thrown_object(thrown_object);
@@ -133,7 +135,7 @@ __cxa_increment_exception_refcount(void *thrown_object) _NOEXCEPT {
     Requires:  If thrown_object is not NULL, it is a native exception.
 */
 _LIBCXXABI_NO_CFI
-void __cxa_decrement_exception_refcount(void *thrown_object) _NOEXCEPT {
+void __cxa_decrement_exception_refcount(void *thrown_object) throw() {
     if (thrown_object != NULL )
     {
         __cxa_exception* exception_header = cxa_exception_from_thrown_object(thrown_object);
@@ -153,3 +155,5 @@ void __cxa_decrement_exception_refcount(void *thrown_object) _NOEXCEPT {
 }  // extern "C"
 
 }  // abi
+
+#endif // __EMSCRIPTEN__
diff --git a/libcxxabi/src/cxa_exception_js_utils.cpp b/libcxxabi/src/cxa_exception_js_utils.cpp
index e2c61aa0967e5..a898a0232dc73 100644
--- a/libcxxabi/src/cxa_exception_js_utils.cpp
+++ b/libcxxabi/src/cxa_exception_js_utils.cpp
@@ -1,3 +1,5 @@
+#ifdef __EMSCRIPTEN__
+
 #include "cxxabi.h"
 
 #include "cxa_exception.h"
@@ -103,3 +105,5 @@ char* __get_exception_terminate_message(void* thrown_object) {
 } // extern "C"
 
 } // namespace __cxxabiv1
+
+#endif // __EMSCRIPTEN__
diff --git a/libcxxabi/src/cxa_noexception.cpp b/libcxxabi/src/cxa_noexception.cpp
index 1ef53bf79f243..38731e6aad8e3 100644
--- a/libcxxabi/src/cxa_noexception.cpp
+++ b/libcxxabi/src/cxa_noexception.cpp
@@ -54,7 +54,7 @@ __cxa_uncaught_exceptions() throw() { return 0; }
 // DISABLE_EXCEPTION_CATCHING is set but DISABLE_EXCEPTION_THROWING is not.
 // TODO(sbc): Perhaps just call std::terminate here. It could
 // just be some test code that needs updating.
-void *__cxa_allocate_exception(size_t thrown_size) _NOEXCEPT {
+void *__cxa_allocate_exception(size_t thrown_size) throw() {
   char* allocation = (char*)malloc(thrown_size + sizeof(__cxa_exception));
   return allocation + sizeof(__cxa_exception);
 }
@@ -68,7 +68,7 @@ cxa_exception_from_thrown_object(void* thrown_object)
 }
 
 //  Free a __cxa_exception object allocated with __cxa_allocate_exception.
-void __cxa_free_exception(void *thrown_object) _NOEXCEPT {
+void __cxa_free_exception(void *thrown_object) throw() {
     // Compute the size of the padding before the header.
     char *raw_buffer =
         ((char *)cxa_exception_from_thrown_object(thrown_object));
diff --git a/libcxxabi/src/cxa_personality.cpp b/libcxxabi/src/cxa_personality.cpp
index 1c37a6434dfb4..69d695d7f8b58 100644
--- a/libcxxabi/src/cxa_personality.cpp
+++ b/libcxxabi/src/cxa_personality.cpp
@@ -31,8 +31,6 @@
 #   define _LIBUNWIND_VERSION
 #endif
 
-#define __USING_SJLJ_OR_WASM_EXCEPTIONS__ (__USING_SJLJ_EXCEPTIONS__ || __USING_WASM_EXCEPTIONS__)
-
 #if defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__)
 #include <windows.h>
 #include <winnt.h>
@@ -72,7 +70,7 @@ extern "C" EXCEPTION_DISPOSITION _GCC_specific_handler(PEXCEPTION_RECORD,
 +------------------+--+-----+-----+------------------------+--------------------------+
 | callSiteTableLength | (ULEB128) | Call Site Table length, used to find Action table |
 +---------------------+-----------+---------------------------------------------------+
-#ifndef __USING_SJLJ_OR_WASM_EXCEPTIONS__
+#if !defined(__USING_SJLJ_EXCEPTIONS__) && !defined(__USING_WASM_EXCEPTIONS__)
 +---------------------+-----------+------------------------------------------------+
 | Beginning of Call Site Table            The current ip lies within the           |
 | ...                                     (start, length) range of one of these    |
@@ -86,7 +84,7 @@ extern "C" EXCEPTION_DISPOSITION _GCC_specific_handler(PEXCEPTION_RECORD,
 | +-------------+---------------------------------+------------------------------+ |
 | ...                                                                              |
 +----------------------------------------------------------------------------------+
-#else  // !__USING_SJLJ_OR_WASM_EXCEPTIONS__
+#else  // __USING_SJLJ_EXCEPTIONS__ || __USING_WASM_EXCEPTIONS__
 +---------------------+-----------+------------------------------------------------+
 | Beginning of Call Site Table            The current ip is a 1-based index into   |
 | ...                                     this table.  Or it is -1 meaning no      |
@@ -99,7 +97,7 @@ extern "C" EXCEPTION_DISPOSITION _GCC_specific_handler(PEXCEPTION_RECORD,
 | +-------------+---------------------------------+------------------------------+ |
 | ...                                                                              |
 +----------------------------------------------------------------------------------+
-#endif // __USING_SJLJ_OR_WASM_EXCEPTIONS__
+#endif // __USING_SJLJ_EXCEPTIONS__ || __USING_WASM_EXCEPTIONS__
 +---------------------------------------------------------------------+
 | Beginning of Action Table       ttypeIndex == 0 : cleanup           |
 | ...                             ttypeIndex  > 0 : catch             |
@@ -549,7 +547,7 @@ void
 set_registers(_Unwind_Exception* unwind_exception, _Unwind_Context* context,
               const scan_results& results)
 {
-#ifdef __USING_SJLJ_OR_WASM_EXCEPTIONS__
+#if defined(__USING_SJLJ_EXCEPTIONS__) || defined(__USING_WASM_EXCEPTIONS__)
 #define __builtin_eh_return_data_regno(regno) regno
 #elif defined(__ibmxl__)
 // IBM xlclang++ compiler does not support __builtin_eh_return_data_regno.
@@ -644,7 +642,7 @@ static void scan_eh_tab(scan_results &results, _Unwind_Action actions,
     // Get beginning current frame's code (as defined by the
     // emitted dwarf code)
     uintptr_t funcStart = _Unwind_GetRegionStart(context);
-#ifdef __USING_SJLJ_OR_WASM_EXCEPTIONS__
+#if defined(__USING_SJLJ_EXCEPTIONS__) || defined(__USING_WASM_EXCEPTIONS__)
     if (ip == uintptr_t(-1))
     {
         // no action
@@ -654,9 +652,9 @@ static void scan_eh_tab(scan_results &results, _Unwind_Action actions,
     else if (ip == 0)
         call_terminate(native_exception, unwind_exception);
     // ip is 1-based index into call site table
-#else  // !__USING_SJLJ_OR_WASM_EXCEPTIONS__
+#else  // !__USING_SJLJ_EXCEPTIONS__ && !__USING_WASM_EXCEPTIONS__
     uintptr_t ipOffset = ip - funcStart;
-#endif // !defined(__USING_SJLJ_OR_WASM_EXCEPTIONS__)
+#endif // !__USING_SJLJ_EXCEPTIONS__ && !__USING_WASM_EXCEPTIONS__
     const uint8_t* classInfo = NULL;
     // Note: See JITDwarfEmitter::EmitExceptionTable(...) for corresponding
     //       dwarf emission
@@ -678,7 +676,7 @@ static void scan_eh_tab(scan_results &results, _Unwind_Action actions,
     // Walk call-site table looking for range that
     // includes current PC.
     uint8_t callSiteEncoding = *lsda++;
-#ifdef __USING_SJLJ_OR_WASM_EXCEPTIONS__
+#if defined(__USING_SJLJ_EXCEPTIONS__) || defined(__USING_WASM_EXCEPTIONS__)
     (void)callSiteEncoding;  // When using SjLj/Wasm exceptions, callSiteEncoding is never used
 #endif
     uint32_t callSiteTableLength = static_cast<uint32_t>(readULEB128(&lsda));
@@ -689,7 +687,7 @@ static void scan_eh_tab(scan_results &results, _Unwind_Action actions,
     while (callSitePtr < callSiteTableEnd)
     {
         // There is one entry per call site.
-#ifndef __USING_SJLJ_OR_WASM_EXCEPTIONS__
+#if !defined(__USING_SJLJ_EXCEPTIONS__) && !defined(__USING_WASM_EXCEPTIONS__)
         // The call sites are non-overlapping in [start, start+length)
         // The call sites are ordered in increasing value of start
         uintptr_t start = readEncodedPointer(&callSitePtr, callSiteEncoding);
@@ -697,15 +695,15 @@ static void scan_eh_tab(scan_results &results, _Unwind_Action actions,
         uintptr_t landingPad = readEncodedPointer(&callSitePtr, callSiteEncoding);
         uintptr_t actionEntry = readULEB128(&callSitePtr);
         if ((start <= ipOffset) && (ipOffset < (start + length)))
-#else  // __USING_SJLJ_OR_WASM_EXCEPTIONS__
+#else  // __USING_SJLJ_EXCEPTIONS__ || __USING_WASM_EXCEPTIONS__
         // ip is 1-based index into this table
         uintptr_t landingPad = readULEB128(&callSitePtr);
         uintptr_t actionEntry = readULEB128(&callSitePtr);
         if (--ip == 0)
-#endif // __USING_SJLJ_OR_WASM_EXCEPTIONS__
+#endif // __USING_SJLJ_EXCEPTIONS__ || __USING_WASM_EXCEPTIONS__
         {
             // Found the call site containing ip.
-#ifndef __USING_SJLJ_OR_WASM_EXCEPTIONS__
+#if !defined(__USING_SJLJ_EXCEPTIONS__) && !defined(__USING_WASM_EXCEPTIONS__)
             if (landingPad == 0)
             {
                 // No handler here
@@ -713,9 +711,9 @@ static void scan_eh_tab(scan_results &results, _Unwind_Action actions,
                 return;
             }
             landingPad = (uintptr_t)lpStart + landingPad;
-#else  // __USING_SJLJ_OR_WASM_EXCEPTIONS__
+#else  // __USING_SJLJ_EXCEPTIONS__ || __USING_WASM_EXCEPTIONS__
             ++landingPad;
-#endif // __USING_SJLJ_OR_WASM_EXCEPTIONS__
+#endif // __USING_SJLJ_EXCEPTIONS__ || __USING_WASM_EXCEPTIONS__
             results.landingPad = landingPad;
             if (actionEntry == 0)
             {
@@ -843,7 +841,7 @@ static void scan_eh_tab(scan_results &results, _Unwind_Action actions,
                 action += actionOffset;
             }  // there is no break out of this loop, only return
         }
-#ifndef __USING_SJLJ_OR_WASM_EXCEPTIONS__
+#if !defined(__USING_SJLJ_EXCEPTIONS__) && !defined(__USING_WASM_EXCEPTIONS__)
         else if (ipOffset < start)
         {
             // There is no call site for this ip
@@ -851,7 +849,7 @@ static void scan_eh_tab(scan_results &results, _Unwind_Action actions,
             // Possible stack corruption.
             call_terminate(native_exception, unwind_exception);
         }
-#endif // !__USING_SJLJ_OR_WASM_EXCEPTIONS__
+#endif // !__USING_SJLJ_EXCEPTIONS__ && !__USING_WASM_EXCEPTIONS__
     }  // there might be some tricky cases which break out of this loop
 
     // It is possible that no eh table entry specify how to handle
diff --git a/libunwind/include/unwind_itanium.h b/libunwind/include/unwind_itanium.h
index ffa46ed9fdc1b..d94a6183be290 100644
--- a/libunwind/include/unwind_itanium.h
+++ b/libunwind/include/unwind_itanium.h
@@ -24,7 +24,7 @@ struct _Unwind_Exception {
                             _Unwind_Exception *exc);
 #if defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__)
   uintptr_t private_[6];
-#elif !defined(__USING_WASM_EXCEPTIONS__)
+#else
   uintptr_t private_1; // non-zero means forced unwind
   uintptr_t private_2; // holds sp that phase1 found for phase2 to use
 #endif
diff --git a/libunwind/src/Unwind-wasm.c b/libunwind/src/Unwind-wasm.c
index daa7d093d72af..35f2f9aeab080 100644
--- a/libunwind/src/Unwind-wasm.c
+++ b/libunwind/src/Unwind-wasm.c
@@ -1,3 +1,15 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//
+//  Implements Wasm exception handling proposal
+//  (https://github.com/WebAssembly/exception-handling) based C++ exceptions
+//
+//===----------------------------------------------------------------------===//
+
 #include "config.h"
 #include "unwind.h"
 #include <stdbool.h>
@@ -41,10 +53,9 @@ _Unwind_Reason_Code _Unwind_CallPersonality(void *exception_ptr) {
 
   // Call personality function. Wasm does not have two-phase unwinding, so we
   // only do the cleanup phase.
-  _Unwind_Reason_Code ret = __gxx_personality_wasm0(
+  return __gxx_personality_wasm0(
       1, _UA_SEARCH_PHASE, exception_object->exception_class, exception_object,
       (struct _Unwind_Context *)&__wasm_lpad_context);
-  return ret;
 }
 
 /// Called by __cxa_throw.
@@ -52,6 +63,7 @@ _LIBUNWIND_EXPORT _Unwind_Reason_Code
 _Unwind_RaiseException(_Unwind_Exception *exception_object) {
   _LIBUNWIND_TRACE_API("_Unwind_RaiseException(exception_object=%p)",
                        (void *)exception_object);
+  // Use Wasm EH's 'throw' instruction.
   __builtin_wasm_throw(0, exception_object);
 }
 
@@ -72,9 +84,8 @@ _LIBUNWIND_EXPORT void _Unwind_SetGR(struct _Unwind_Context *context, int index,
                        (void *)context, index, value);
   // We only use this function to set __wasm_lpad_context.selector field, which
   // is index 1 in the personality function.
-  if (index != 1)
-    return;
-  ((struct _Unwind_LandingPadContext *)context)->selector = value;
+  if (index == 1)
+    ((struct _Unwind_LandingPadContext *)context)->selector = value;
 }
 
 /// Called by personality handler to get instruction pointer.
@@ -88,7 +99,7 @@ _LIBUNWIND_EXPORT uintptr_t _Unwind_GetIP(struct _Unwind_Context *context) {
   return result;
 }
 
-/// Not used in wasm.
+/// Not used in Wasm.
 _LIBUNWIND_EXPORT void _Unwind_SetIP(struct _Unwind_Context *context,
                                      uintptr_t value) {}
 
@@ -101,7 +112,7 @@ _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context) {
   return result;
 }
 
-/// Not used in wasm.
+/// Not used in Wasm.
 _LIBUNWIND_EXPORT uintptr_t
 _Unwind_GetRegionStart(struct _Unwind_Context *context) {
   return 0;
diff --git a/libunwind/src/config.h b/libunwind/src/config.h
index c7584edc34438..d0c062cad5f1a 100644
--- a/libunwind/src/config.h
+++ b/libunwind/src/config.h
@@ -83,7 +83,7 @@
   __asm__(".globl " SYMBOL_NAME(aliasname));                                   \
   __asm__(SYMBOL_NAME(aliasname) " = " SYMBOL_NAME(name));                     \
   _LIBUNWIND_ALIAS_VISIBILITY(SYMBOL_NAME(aliasname))
-#elif defined(__ELF__) || defined(_AIX)
+#elif defined(__ELF__) || defined(_AIX) || defined(__wasm__)
 #define _LIBUNWIND_WEAK_ALIAS(name, aliasname)                                 \
   extern "C" _LIBUNWIND_EXPORT __typeof(name) aliasname                        \
       __attribute__((weak, alias(#name)));
@@ -98,7 +98,6 @@
                                              SYMBOL_NAME(name)))               \
   extern "C" _LIBUNWIND_EXPORT __typeof(name) aliasname;
 #endif
-#elif defined(__EMSCRIPTEN__)
 #else
 #error Unsupported target
 #endif