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// -*- C++ -*- ARM specific Exception handling support routines.
// Copyright (C) 2004-2021 Free Software Foundation, Inc.
// This file is part of GCC.
// GCC is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3, or (at your option)
// any later version.
// GCC is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <>.
#include <cxxabi.h>
#include "unwind-cxx.h"
using namespace __cxxabiv1;
// Given the thrown type THROW_TYPE, exception object UE_HEADER and a
// type CATCH_TYPE to compare against, return whether or not there is
// a match and if so, update *THROWN_PTR_P to point to either the
// type-matched object, or in the case of a pointer type, the object
// pointed to by the pointer.
extern "C" __cxa_type_match_result
__cxa_type_match(_Unwind_Exception* ue_header,
const std::type_info* catch_type,
bool is_reference __attribute__((__unused__)),
void** thrown_ptr_p)
bool forced_unwind
= __is_gxx_forced_unwind_class(ue_header->exception_class);
bool foreign_exception
= !forced_unwind && !__is_gxx_exception_class(ue_header->exception_class);
bool dependent_exception
= __is_dependent_exception(ue_header->exception_class);
__cxa_exception* xh = __get_exception_header_from_ue(ue_header);
__cxa_dependent_exception *dx = __get_dependent_exception_from_ue(ue_header);
const std::type_info* throw_type;
void *thrown_ptr = 0;
if (forced_unwind)
throw_type = &typeid(abi::__forced_unwind);
else if (foreign_exception)
throw_type = &typeid(abi::__foreign_exception);
if (dependent_exception)
xh = __get_exception_header_from_obj (dx->primaryException);
throw_type = xh->exceptionType;
// We used to require the caller set the target of thrown_ptr_p,
// but that's incorrect -- the EHABI makes no such requirement
// -- and not all callers will set it. Fortunately callers that
// do initialize will always pass us the value we calculate
// here, so there's no backwards compatibility problem.
thrown_ptr = __get_object_from_ue (ue_header);
__cxa_type_match_result result = ctm_succeeded;
// Pointer types need to adjust the actual pointer, not
// the pointer to pointer that is the exception object.
// This also has the effect of passing pointer types
// "by value" through the __cxa_begin_catch return value.
if (throw_type->__is_pointer_p())
thrown_ptr = *(void**) thrown_ptr;
// We need to indicate the indirection to our caller.
result = ctm_succeeded_with_ptr_to_base;
if (catch_type->__do_catch(throw_type, &thrown_ptr, 1))
*thrown_ptr_p = thrown_ptr;
return result;
return ctm_failed;
// ABI defined routine called at the start of a cleanup handler.
extern "C" bool
__cxa_begin_cleanup(_Unwind_Exception* ue_header)
__cxa_eh_globals *globals = __cxa_get_globals();
__cxa_exception *header = __get_exception_header_from_ue(ue_header);
bool native = __is_gxx_exception_class(header->unwindHeader.exception_class);
if (native)
// Add it to the chain if this is the first time we've seen this
// exception.
if (header->propagationCount == 1)
header->nextPropagatingException = globals->propagatingExceptions;
globals->propagatingExceptions = header;
// Remember the exception object, so end_cleanup can return it.
// These cannot be stacked, so we must abort if we already have
// a propagating exception.
if (globals->propagatingExceptions)
std::terminate ();
globals->propagatingExceptions = header;
return true;
// Do the work for __cxa_end_cleanup. Returns the currently propagating
// exception object.
extern "C" _Unwind_Exception *
__cxa_exception *header;
__cxa_eh_globals *globals = __cxa_get_globals();
header = globals->propagatingExceptions;
// Check something hasn't gone horribly wrong.
if (!header)
if (__is_gxx_exception_class(header->unwindHeader.exception_class))
if (header->propagationCount == 0)
// Remove exception from chain.
globals->propagatingExceptions = header->nextPropagatingException;
header->nextPropagatingException = NULL;
globals->propagatingExceptions = NULL;
return &header->unwindHeader;
#ifdef __TMS320C6X__
// Assembly wrapper to call __gnu_end_cleanup without clobbering
// function arguments to _Unwind_Resume.
asm (".global __cxa_end_cleanup\n"
" .type __cxa_end_cleanup, \"function\"\n"
" stw .d2t2 B9, *B15--[10]\n"
" stw .d2t2 B8, *+B15[9]\n"
" stw .d2t2 B7, *+B15[8]\n"
" stw .d2t2 B6, *+B15[7]\n"
" stw .d2t2 B5, *+B15[6]\n"
" stw .d2t2 B4, *+B15[5]\n"
" stw .d2t1 A9, *+B15[4]\n"
" stw .d2t1 A8, *+B15[3]\n"
" stw .d2t1 A7, *+B15[2]\n"
" stw .d2t1 A6, *+B15[1]\n"
#ifdef _TMS320C6400_PLUS
" callp .s2 (__gnu_end_cleanup), B3\n"
#elif defined(_TMS320C6400)
" call .s2 (__gnu_end_cleanup)\n"
" addkpc .s2 1f, B3, 0\n"
" nop 4\n"
" call .s2 (__gnu_end_cleanup)\n"
" mvkl .s2 1f, B3\n"
" mvkh .s2 1f, B3\n"
" nop 3\n"
" ldw .d2t1 *+B15[1], A6\n"
" ldw .d2t1 *+B15[2], A7\n"
" ldw .d2t1 *+B15[3], A8\n"
" ldw .d2t1 *+B15[4], A9\n"
" ldw .d2t2 *+B15[5], B4\n"
" ldw .d2t2 *+B15[6], B5\n"
" ldw .d2t2 *+B15[7], B6\n"
" ldw .d2t2 *+B15[8], B7\n"
" ldw .d2t2 *+B15[9], B8\n"
" ldw .d2t2 *++B15[10], B9\n"
" b .s2 _Unwind_Resume\n"
" nop 5\n");
// Assembly wrapper to call __gnu_end_cleanup without clobbering r1-r3.
// Also push r4 to preserve stack alignment.
#ifdef __thumb__
asm (" .pushsection .text.__cxa_end_cleanup\n"
" .global __cxa_end_cleanup\n"
" .type __cxa_end_cleanup, \"function\"\n"
" .thumb_func\n"
" push\t{r1, r2, r3, r4}\n"
" bl\t__gnu_end_cleanup\n"
" pop\t{r1, r2, r3, r4}\n"
" bl\t_Unwind_Resume @ Never returns\n"
" .popsection\n");
asm (" .pushsection .text.__cxa_end_cleanup\n"
" .global __cxa_end_cleanup\n"
" .type __cxa_end_cleanup, \"function\"\n"
" stmfd\tsp!, {r1, r2, r3, r4}\n"
" bl\t__gnu_end_cleanup\n"
" ldmfd\tsp!, {r1, r2, r3, r4}\n"
" bl\t_Unwind_Resume @ Never returns\n"
" .popsection\n");