From 9f5f78e16a741d487eb3725122a42b028cfc8129 Mon Sep 17 00:00:00 2001 From: Akira Hatanaka Date: Sat, 13 May 2017 06:28:17 +0000 Subject: [libcxxabi] Do not align field unwindHeader when building for ARM EHABI. For ARM EHABI, _Unwind_Exception is an alias of _Unwind_Control_Block, which is not aligned, so we shouldn't align unwindHeader either. rdar://problem/25364625 git-svn-id: https://llvm.org/svn/llvm-project/libcxxabi/trunk@302981 91177308-0d34-0410-b5e6-96231b3b80d8 --- src/cxa_exception.hpp | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) (limited to 'src') diff --git a/src/cxa_exception.hpp b/src/cxa_exception.hpp index 2d34698..b9f74e3 100644 --- a/src/cxa_exception.hpp +++ b/src/cxa_exception.hpp @@ -64,10 +64,18 @@ struct _LIBCXXABI_HIDDEN __cxa_exception { // This field is annotated with attribute aligned so that the exception // object following the field is sufficiently aligned and there is no // gap between the field and the exception object. r276215 made a change to - // annotate _Unwind_Exception with __attribute__((aligned)), but we cannot - // incorporate the fix on Darwin since it is an ABI-breaking change, which - // is why we need the attribute on this field. + // annotate _Unwind_Exception in unwind.h with __attribute__((aligned)), but + // we cannot incorporate the fix on Darwin since it is an ABI-breaking + // change, which is why we need the attribute on this field. + // + // For ARM EHABI, we do not align this field since _Unwind_Exception is an + // alias of _Unwind_Control_Block, which is not annotated with + // __attribute__((aligned). +#if defined(_LIBCXXABI_ARM_EHABI) + _Unwind_Exception unwindHeader; +#else _Unwind_Exception unwindHeader __attribute__((aligned)); +#endif }; // http://sourcery.mentor.com/archives/cxx-abi-dev/msg01924.html @@ -104,7 +112,11 @@ struct _LIBCXXABI_HIDDEN __cxa_dependent_exception { // See the comment in __cxa_exception as to why this field has attribute // aligned. +#if defined(_LIBCXXABI_ARM_EHABI) + _Unwind_Exception unwindHeader; +#else _Unwind_Exception unwindHeader __attribute__((aligned)); +#endif }; struct _LIBCXXABI_HIDDEN __cxa_eh_globals { -- cgit v1.2.3