[libcxx-commits] [libcxx] [libcxxabi] [WebAssembly] Upstream misc. EH changes (PR #92990)

[Heejin Ahn via libcxx-commits]

https://github.com/aheejin created https://github.com/llvm/llvm-project/pull/92990

This upstreams more recent, mostly EH changes from libcxx and libcxxabi:
- `__cxa_init_primary_exception`-related changes made when updating to LLVM 18.1.2 (https://github.com/emscripten-core/emscripten/pull/21638)
- Removes ctype macros (https://github.com/emscripten-core/emscripten/pull/20960)
- Guard destructor changes with `__wasm__` (https://github.com/emscripten-core/emscripten/pull/21974)

>From e9b94cdff7fe222130af626063408b6e78def8cf Mon Sep 17 00:00:00 2001
From: Heejin Ahn <aheejin at gmail.com>
Date: Wed, 22 May 2024 00:30:11 +0000
Subject: [PATCH] [WebAssembly] Upstream misc. EH changes

This upstreams more recent, mostly EH changes from libcxx and libcxxabi:
- `__cxa_init_primary_exception`-related changes made when updating to
  LLVM 18.1.2 (https://github.com/emscripten-core/emscripten/pull/21638)
- Removes ctype macros
  (https://github.com/emscripten-core/emscripten/pull/20960)
- Guard destructor changes with `__wasm__`
  (https://github.com/emscripten-core/emscripten/pull/21974)
---
 libcxx/include/__exception/exception_ptr.h | 17 ++++++++++++++---
 libcxx/include/__locale                    |  4 ++--
 libcxxabi/include/cxxabi.h                 |  8 ++++++--
 libcxxabi/src/cxa_exception.cpp            |  7 ++++++-
 libcxxabi/src/cxa_exception.h              |  2 +-
 5 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/libcxx/include/__exception/exception_ptr.h b/libcxx/include/__exception/exception_ptr.h
index c9027de9238cd..868fd7c015339 100644
--- a/libcxx/include/__exception/exception_ptr.h
+++ b/libcxx/include/__exception/exception_ptr.h
@@ -38,11 +38,14 @@ struct __cxa_exception;
 _LIBCPP_OVERRIDABLE_FUNC_VIS __cxa_exception* __cxa_init_primary_exception(
     void*,
     std::type_info*,
-    void(
 #    if defined(_WIN32)
-        __thiscall
+    void(__thiscall*)(void*)) throw();
+#    elif defined(__wasm__)
+    // In Wasm, a destructor returns its argument
+    void* (*)(void*)) throw();
+#    else
+    void (*)(void*)) throw();
 #    endif
-            *)(void*)) throw();
 }
 
 } // namespace __cxxabiv1
@@ -92,8 +95,16 @@ _LIBCPP_HIDE_FROM_ABI exception_ptr make_exception_ptr(_Ep __e) _NOEXCEPT {
   using _Ep2 = __decay_t<_Ep>;
 
   void* __ex = __cxxabiv1::__cxa_allocate_exception(sizeof(_Ep));
+#      ifdef __wasm__
+  // In Wasm, a destructor returns its argument
+  (void)__cxxabiv1::__cxa_init_primary_exception(__ex, const_cast<std::type_info*>(&typeid(_Ep)), [](void* __p) -> void* {
+#      else
   (void)__cxxabiv1::__cxa_init_primary_exception(__ex, const_cast<std::type_info*>(&typeid(_Ep)), [](void* __p) {
+#      endif
     std::__destroy_at(static_cast<_Ep2*>(__p));
+#      ifdef __wasm__
+    return __p;
+#      endif
   });
 
   try {
diff --git a/libcxx/include/__locale b/libcxx/include/__locale
index 36ac099d650e4..1e97c7594c8bf 100644
--- a/libcxx/include/__locale
+++ b/libcxx/include/__locale
@@ -343,12 +343,12 @@ public:
   static const mask __regex_word = 0x4000; // 0x8000 and 0x0100 and 0x00ff are used
 #  define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_PRINT
 #  define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_ALPHA
-#elif defined(__APPLE__) || defined(__FreeBSD__) || defined(__EMSCRIPTEN__) || defined(__NetBSD__)
+#elif defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__)
 #  ifdef __APPLE__
   typedef __uint32_t mask;
 #  elif defined(__FreeBSD__)
   typedef unsigned long mask;
-#  elif defined(__EMSCRIPTEN__) || defined(__NetBSD__)
+#  elif defined(__NetBSD__)
   typedef unsigned short mask;
 #  endif
   static const mask space  = _CTYPE_S;
diff --git a/libcxxabi/include/cxxabi.h b/libcxxabi/include/cxxabi.h
index 9d9beecf751fc..0e3969084e04f 100644
--- a/libcxxabi/include/cxxabi.h
+++ b/libcxxabi/include/cxxabi.h
@@ -48,13 +48,17 @@ extern _LIBCXXABI_FUNC_VIS void
 __cxa_free_exception(void *thrown_exception) throw();
 // This function is an LLVM extension, which mirrors the same extension in libsupc++ and libcxxrt
 extern _LIBCXXABI_FUNC_VIS __cxa_exception*
+#ifdef __wasm__
+// In Wasm, a destructor returns its argument
+__cxa_init_primary_exception(void* object, std::type_info* tinfo, void*(_LIBCXXABI_DTOR_FUNC* dest)(void*)) throw();
+#else
 __cxa_init_primary_exception(void* object, std::type_info* tinfo, void(_LIBCXXABI_DTOR_FUNC* dest)(void*)) throw();
+#endif
 
 // 2.4.3 Throwing the Exception Object
 extern _LIBCXXABI_FUNC_VIS _LIBCXXABI_NORETURN void
 __cxa_throw(void *thrown_exception, std::type_info *tinfo,
-#ifdef __WASM_EXCEPTIONS__
-            // In Wasm, a destructor returns its argument
+#ifdef __wasm__
             void *(_LIBCXXABI_DTOR_FUNC *dest)(void *));
 #else
             void (_LIBCXXABI_DTOR_FUNC *dest)(void *));
diff --git a/libcxxabi/src/cxa_exception.cpp b/libcxxabi/src/cxa_exception.cpp
index 3141d50a6bb92..ff69a4c65e465 100644
--- a/libcxxabi/src/cxa_exception.cpp
+++ b/libcxxabi/src/cxa_exception.cpp
@@ -207,7 +207,12 @@ void __cxa_free_exception(void *thrown_object) throw() {
 }
 
 __cxa_exception* __cxa_init_primary_exception(void* object, std::type_info* tinfo,
+#ifdef __wasm__
+// In Wasm, a destructor returns its argument
+                                              void *(_LIBCXXABI_DTOR_FUNC* dest)(void*)) throw() {
+#else
                                               void(_LIBCXXABI_DTOR_FUNC* dest)(void*)) throw() {
+#endif
   __cxa_exception* exception_header = cxa_exception_from_thrown_object(object);
   exception_header->referenceCount = 0;
   exception_header->unexpectedHandler = std::get_unexpected();
@@ -267,7 +272,7 @@ will call terminate, assuming that there was no handler for the
 exception.
 */
 void
-#ifdef __WASM_EXCEPTIONS__
+#ifdef __wasm__
 // In Wasm, a destructor returns its argument
 __cxa_throw(void *thrown_object, std::type_info *tinfo, void *(_LIBCXXABI_DTOR_FUNC *dest)(void *)) {
 #else
diff --git a/libcxxabi/src/cxa_exception.h b/libcxxabi/src/cxa_exception.h
index 7800b940b83f7..aba08f2992103 100644
--- a/libcxxabi/src/cxa_exception.h
+++ b/libcxxabi/src/cxa_exception.h
@@ -43,7 +43,7 @@ struct _LIBCXXABI_HIDDEN __cxa_exception {
 
     //  Manage the exception object itself.
     std::type_info *exceptionType;
-#ifdef __WASM_EXCEPTIONS__
+#ifdef __wasm__
     // In Wasm, a destructor returns its argument
     void *(_LIBCXXABI_DTOR_FUNC *exceptionDestructor)(void *);
 #else