cosmopolitan/third_party/libcxxabi/cxa_handlers.cc
Trung Nguyen 8b33204f37
Add LLVM libcxxabi (#1063)
* third_party: Add libcxxabi

Added libcxxabi from LLVM 17.0.6
The library implements the Itanium C++ exception handling ABI.

* third_party/libcxxabi: Enable __cxa_thread_atexit

Enable `__cxa_thread_atexit` from libcxxabi.
`__cxa_thread_atexit_impl` is still implemented by the cosmo libc.
The original `__cxa_thread_atexit` has been removed.

* third_party/libcxx: Build with exceptions

Build libcxx with exceptions enabled.

- Removed `_LIBCPP_NO_EXCEPTIONS` from `__config`.
- Switched the exception implementation to `libcxxabi`. These two files
are taken from the same `libcxx` version as mentioned in `README.cosmo`.
- Removed `new_handler_fallback` in favor of `libcxxabi` implementation.
- Enable `-fexceptions` and `-frtti` for `libcxx`.
- Removed `THIRD_PARTY_LIBCXX` dependency from `libcxxabi` and
`libunwind`. These libraries do not use any runtime `libcxx` functions,
just headers.

* libc: Remove remaining redundant cxa functions

- `__cxa_pure_virtual` in `libcxxabi` is also a stub similar to the
existing one.
- `__cxa_guard_*` from `libcxxabi` is used instead of the ones from
Android.

Now there should be no more duplicate implementations.
`__cxa_thread_atexit_impl`, `__cxa_atexit`, and related supporting
functions, are still left to other libraries as in `libcxxabi`.

`libcxxabi` is also now added to `cosmopolitan.a` to make up for the
removed functions.

Affected in-tree libraries (`third_party/double-conversion`) have been
updated.
2024-01-08 08:45:10 -08:00

101 lines
2.6 KiB
C++

//===----------------------------------------------------------------------===//
//
// 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
//
//
// This file implements the functionality associated with the terminate_handler,
// unexpected_handler, and new_handler.
//===----------------------------------------------------------------------===//
#include "third_party/libcxx/stdexcept"
#include "third_party/libcxx/new"
#include "third_party/libcxx/exception"
#include "third_party/libcxxabi/abort_message.h"
#include "third_party/libcxxabi/include/cxxabi.h"
#include "third_party/libcxxabi/cxa_handlers.h"
#include "third_party/libcxxabi/cxa_exception.h"
#include "third_party/libcxxabi/private_typeinfo.h"
#include "third_party/libcxx/include/atomic_support.hh" // from libc++
namespace std
{
unexpected_handler
get_unexpected() noexcept
{
return __libcpp_atomic_load(&__cxa_unexpected_handler, _AO_Acquire);
}
void
__unexpected(unexpected_handler func)
{
func();
// unexpected handler should not return
abort_message("unexpected_handler unexpectedly returned");
}
__attribute__((noreturn))
void
unexpected()
{
__unexpected(get_unexpected());
}
terminate_handler
get_terminate() noexcept
{
return __libcpp_atomic_load(&__cxa_terminate_handler, _AO_Acquire);
}
void
__terminate(terminate_handler func) noexcept
{
#ifndef _LIBCXXABI_NO_EXCEPTIONS
try
{
#endif // _LIBCXXABI_NO_EXCEPTIONS
func();
// handler should not return
abort_message("terminate_handler unexpectedly returned");
#ifndef _LIBCXXABI_NO_EXCEPTIONS
}
catch (...)
{
// handler should not throw exception
abort_message("terminate_handler unexpectedly threw an exception");
}
#endif // _LIBCXXABI_NO_EXCEPTIONS
}
__attribute__((noreturn))
void
terminate() noexcept
{
#ifndef _LIBCXXABI_NO_EXCEPTIONS
// If there might be an uncaught exception
using namespace __cxxabiv1;
__cxa_eh_globals* globals = __cxa_get_globals_fast();
if (globals)
{
__cxa_exception* exception_header = globals->caughtExceptions;
if (exception_header)
{
_Unwind_Exception* unwind_exception =
reinterpret_cast<_Unwind_Exception*>(exception_header + 1) - 1;
if (__isOurExceptionClass(unwind_exception))
__terminate(exception_header->terminateHandler);
}
}
#endif
__terminate(get_terminate());
}
new_handler
get_new_handler() noexcept
{
return __libcpp_atomic_load(&__cxa_new_handler, _AO_Acquire);
}
} // std