From bd1255f6bc4347dde7a54472074955dd873964cc Mon Sep 17 00:00:00 2001 From: LLVM Packaging Team Date: Thu, 19 Mar 2020 08:50:20 +0000 Subject: [PATCH] libcxxabi-arm-ehabi-fix Fix arm EHABI code to work. armhf had exception test failing without EHABI support. No known upstream bug about this. Actual code change is more like workaround than something that upstream would accept. Proper fix would be adding _Unwind_Control_Block to clang unwind.h. _Unwind_Control_Block should also extend _Unwind_Exception to make sure their ABI stays in sync. No known upstream bug about this. Gbp-Pq: Topic libcxx Gbp-Pq: Name libcxxabi-arm-ehabi-fix.patch --- libcxxabi/src/cxa_exception.cpp | 17 ++++++++++---- libcxxabi/src/cxa_exception.hpp | 39 +++++++++++++++++++++++++++++++++ 2 files changed, 52 insertions(+), 4 deletions(-) diff --git a/libcxxabi/src/cxa_exception.cpp b/libcxxabi/src/cxa_exception.cpp index 8d30e5ce4..4b824f695 100644 --- a/libcxxabi/src/cxa_exception.cpp +++ b/libcxxabi/src/cxa_exception.cpp @@ -277,15 +277,16 @@ __cxa_throw(void *thrown_object, std::type_info *tinfo, void (*dest)(void *)) { #ifdef __USING_SJLJ_EXCEPTIONS__ _Unwind_SjLj_RaiseException(&exception_header->unwindHeader); -#else +#elif !LIBCXXABI_ARM_EHABI _Unwind_RaiseException(&exception_header->unwindHeader); +#else + _Unwind_RaiseException(exception_header->unwindHeader); #endif // This only happens when there is no handler, or some unexpected unwinding // error happens. failed_throw(exception_header); } - // 2.5.3 Exception Handlers /* The adjusted pointer is computed by the personality routine during phase 1 @@ -548,7 +549,11 @@ void __cxa_end_catch() { // to touch a foreign exception in any way, that is undefined // behavior. They likely can't since the only way to catch // a foreign exception is with catch (...)! +#if !LIBCXXABI_ARM_EHABI _Unwind_DeleteException(&globals->caughtExceptions->unwindHeader); +#else + _Unwind_DeleteException(globals->caughtExceptions->unwindHeader); +#endif globals->caughtExceptions = 0; } } @@ -605,8 +610,10 @@ void __cxa_rethrow() { } #ifdef __USING_SJLJ_EXCEPTIONS__ _Unwind_SjLj_RaiseException(&exception_header->unwindHeader); -#else +#elif !LIBCXXABI_ARM_EHABI _Unwind_RaiseException(&exception_header->unwindHeader); +#else + _Unwind_RaiseException(exception_header->unwindHeader); #endif // If we get here, some kind of unwinding error has occurred. @@ -730,8 +737,10 @@ __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 !LIBCXXABI_ARM_EHABI + _Unwind_RaiseException(&dep_exception_header->unwindHeader); #else - _Unwind_RaiseException(&dep_exception_header->unwindHeader); + _Unwind_RaiseException(dep_exception_header->unwindHeader); #endif // Some sort of unwinding error. Note that terminate is a handler. __cxa_begin_catch(&dep_exception_header->unwindHeader); diff --git a/libcxxabi/src/cxa_exception.hpp b/libcxxabi/src/cxa_exception.hpp index 6d98e11a6..6254b4b65 100644 --- a/libcxxabi/src/cxa_exception.hpp +++ b/libcxxabi/src/cxa_exception.hpp @@ -28,6 +28,45 @@ uint64_t __getExceptionClass (const _Unwind_Exception*); void __setExceptionClass ( _Unwind_Exception*, uint64_t); bool __isOurExceptionClass(const _Unwind_Exception*); +#if LIBCXXABI_ARM_EHABI +// GCC has _Unwind_Control_Block in unwind.h (unwind_arm_common.h) +#if defined(__clang__) +struct _Unwind_Control_Block +{ + uint64_t exception_class; + void (*exception_cleanup)(_Unwind_Reason_Code, _Unwind_Control_Block *); + struct { + _Unwind_Word reserved1; + _Unwind_Word reserved2; + _Unwind_Word reserved3; + _Unwind_Word reserved4; + _Unwind_Word reserved5; + } unwinder_cache; + struct { + _Unwind_Word sp; + _Unwind_Word bitpattern[5]; + } barrier_cache; + struct { + _Unwind_Word bitpattern[4]; + } cleanup_cache; + struct { + _Unwind_Word fnstart; + _Unwind_Word *ehtp; + _Unwind_Word additional; + _Unwind_Word reserved1; + } pr_cache; + long long int :0; + operator _Unwind_Exception*() noexcept + { + return reinterpret_cast<_Unwind_Exception*>(this); + } +}; + +#endif + +#define _Unwind_Exception _Unwind_Control_Block +#endif + struct _LIBCXXABI_HIDDEN __cxa_exception { #if defined(__LP64__) || defined(_LIBCXXABI_ARM_EHABI) // This is a new field to support C++ 0x exception_ptr. -- 2.30.2