[WebAssembly] Upstream misc. EH changes #92990

aheejin · 2024-05-22T04:06:40Z

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 (Update libcxx and libcxxabi to LLVM 18.1.2 emscripten-core/emscripten#21638)
Removes ctype macros (Remove ctype compat macros. NFC emscripten-core/emscripten#20960)
Guard destructor changes with __wasm__ ([EH] Guard destructor changes in libc++abi with __wasm__ emscripten-core/emscripten#21974)

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 (emscripten-core/emscripten#21638) - Removes ctype macros (emscripten-core/emscripten#20960) - Guard destructor changes with `__wasm__` (emscripten-core/emscripten#21974)

llvmbot · 2024-05-22T04:07:13Z

@llvm/pr-subscribers-libcxxabi

Author: Heejin Ahn (aheejin)

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 (Update libcxx and libcxxabi to LLVM 18.1.2 emscripten-core/emscripten#21638)
Removes ctype macros (Remove ctype compat macros. NFC emscripten-core/emscripten#20960)
Guard destructor changes with __wasm__ ([EH] Guard destructor changes in libc++abi with __wasm__ emscripten-core/emscripten#21974)

Full diff: https://github.com/llvm/llvm-project/pull/92990.diff

5 Files Affected:

(modified) libcxx/include/__exception/exception_ptr.h (+14-3)
(modified) libcxx/include/__locale (+2-2)
(modified) libcxxabi/include/cxxabi.h (+6-2)
(modified) libcxxabi/src/cxa_exception.cpp (+6-1)
(modified) libcxxabi/src/cxa_exception.h (+1-1)

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

llvmbot · 2024-05-22T04:07:13Z

@llvm/pr-subscribers-libcxx

Author: Heejin Ahn (aheejin)

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 (Update libcxx and libcxxabi to LLVM 18.1.2 emscripten-core/emscripten#21638)
Removes ctype macros (Remove ctype compat macros. NFC emscripten-core/emscripten#20960)
Guard destructor changes with __wasm__ ([EH] Guard destructor changes in libc++abi with __wasm__ emscripten-core/emscripten#21974)

Full diff: https://github.com/llvm/llvm-project/pull/92990.diff

5 Files Affected:

(modified) libcxx/include/__exception/exception_ptr.h (+14-3)
(modified) libcxx/include/__locale (+2-2)
(modified) libcxxabi/include/cxxabi.h (+6-2)
(modified) libcxxabi/src/cxa_exception.cpp (+6-1)
(modified) libcxxabi/src/cxa_exception.h (+1-1)

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

github-actions · 2024-05-22T04:09:39Z

⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️

You can test this locally with the following command:

git-clang-format --diff d53c6cdbc108729ce5dc7d4e9184db025206fefc e9b94cdff7fe222130af626063408b6e78def8cf -- libcxx/include/__exception/exception_ptr.h libcxx/include/__locale libcxxabi/include/cxxabi.h libcxxabi/src/cxa_exception.cpp libcxxabi/src/cxa_exception.h

View the diff from clang-format here.

diff --git a/libcxx/include/__exception/exception_ptr.h b/libcxx/include/__exception/exception_ptr.h
index 868fd7c015..a67299fae0 100644
--- a/libcxx/include/__exception/exception_ptr.h
+++ b/libcxx/include/__exception/exception_ptr.h
@@ -97,15 +97,16 @@ _LIBCPP_HIDE_FROM_ABI exception_ptr make_exception_ptr(_Ep __e) _NOEXCEPT {
   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* {
+  (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));
+        std::__destroy_at(static_cast<_Ep2*>(__p));
 #      ifdef __wasm__
-    return __p;
+        return __p;
 #      endif
-  });
+      });
 
   try {
     ::new (__ex) _Ep2(__e);
diff --git a/libcxxabi/include/cxxabi.h b/libcxxabi/include/cxxabi.h
index 0e3969084e..27507dc298 100644
--- a/libcxxabi/include/cxxabi.h
+++ b/libcxxabi/include/cxxabi.h
@@ -48,21 +48,20 @@ 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__
+#  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
+#  else
 __cxa_init_primary_exception(void* object, std::type_info* tinfo, void(_LIBCXXABI_DTOR_FUNC* dest)(void*)) throw();
-#endif
+#  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__
-            void *(_LIBCXXABI_DTOR_FUNC *dest)(void *));
-#else
+extern _LIBCXXABI_FUNC_VIS _LIBCXXABI_NORETURN void __cxa_throw(void* thrown_exception, std::type_info* tinfo,
+#  ifdef __wasm__
+                                                                void*(_LIBCXXABI_DTOR_FUNC* dest)(void*));
+#  else
             void (_LIBCXXABI_DTOR_FUNC *dest)(void *));
-#endif
+#  endif
 
 // 2.5.3 Exception Handlers
 extern _LIBCXXABI_FUNC_VIS void *
diff --git a/libcxxabi/src/cxa_exception.cpp b/libcxxabi/src/cxa_exception.cpp
index ff69a4c65e..0d3f37a607 100644
--- a/libcxxabi/src/cxa_exception.cpp
+++ b/libcxxabi/src/cxa_exception.cpp
@@ -208,8 +208,8 @@ 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() {
+                                              // In Wasm, a destructor returns its argument
+                                              void*(_LIBCXXABI_DTOR_FUNC* dest)(void*)) throw() {
 #else
                                               void(_LIBCXXABI_DTOR_FUNC* dest)(void*)) throw() {
 #endif
@@ -274,7 +274,7 @@ exception.
 void
 #ifdef __wasm__
 // In Wasm, a destructor returns its argument
-__cxa_throw(void *thrown_object, std::type_info *tinfo, void *(_LIBCXXABI_DTOR_FUNC *dest)(void *)) {
+__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 *)) {
 #endif

aheejin · 2024-05-22T04:11:53Z

This fails clang-format, but the modified files don't conform to clang-format in the first place, and I tried to match the style the files were written in.

ldionne · 2024-07-04T16:55:05Z

As a matter of process, please do not merge patches to libc++/libc++abi/libunwind unless you have an approval from the relevant review group. Anyone is free to provide a code review, but the final approval must be granted by the review group. I know this wasn't done with a bad intention, I just want to make sure that our policies are understood and followed by folks.

On a different note, we should set up a CI job that builds and tests libc++ on Wasm. Our support policy mentions that we must have CI set up in order to officially support a platform, and what happened here is that patches of increasing intrusiveness were checked in and kinda got under the radar, so we never really discussed about the support policy for wasm. As it stands, wasm is technically not supported by libc++ so we'd be free to remove all the code as dead. Of course, we don't want to do that, but instead we should bring wasm in line with the other supported platforms and then we can officially claim support for it.

aheejin requested a review from sbc100 May 22, 2024 04:06

aheejin requested review from a team as code owners May 22, 2024 04:06

llvmbot added libc++ libc++ C++ Standard Library. Not GNU libstdc++. Not libc++abi. libc++abi libc++abi C++ Runtime Library. Not libc++. labels May 22, 2024

sbc100 approved these changes May 22, 2024

View reviewed changes

aheejin merged commit 271eb06 into llvm:main May 22, 2024
53 of 54 checks passed

aheejin deleted the upstream_lib branch May 22, 2024 16:47

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[WebAssembly] Upstream misc. EH changes #92990

[WebAssembly] Upstream misc. EH changes #92990

aheejin commented May 22, 2024

llvmbot commented May 22, 2024

llvmbot commented May 22, 2024

github-actions bot commented May 22, 2024

aheejin commented May 22, 2024

ldionne commented Jul 4, 2024

[WebAssembly] Upstream misc. EH changes #92990

[WebAssembly] Upstream misc. EH changes #92990

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aheejin commented May 22, 2024

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llvmbot commented May 22, 2024

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