331 lines
9.9 KiB
C
331 lines
9.9 KiB
C
/* Exception handling and frame unwind runtime interface routines. -*- C -*-
|
|
Copyright (C) 2001-2021 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 MERCHANTABILITY
|
|
or FITNESS FOR A PARTICULAR PURPOSE. See the 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
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
/* This is derived from the C++ ABI for IA-64. Where we diverge
|
|
for cross-architecture compatibility are noted with "@@@".
|
|
This file is included from unwind-dw2.c, unwind-sjlj.c or
|
|
unwind-ia64.c. */
|
|
|
|
/* Subroutine of _Unwind_RaiseException also invoked from _Unwind_Resume.
|
|
|
|
Unwind the stack calling the personality routine to find both the
|
|
exception handler and intermediary cleanup code. We'll only locate
|
|
the first such frame here. Cleanup code will call back into
|
|
_Unwind_Resume and we'll continue Phase 2 there. */
|
|
|
|
static _Unwind_Reason_Code
|
|
_Unwind_RaiseException_Phase2(struct _Unwind_Exception *exc,
|
|
struct _Unwind_Context *context,
|
|
unsigned long *frames_p)
|
|
{
|
|
_Unwind_Reason_Code code;
|
|
unsigned long frames = 1;
|
|
|
|
while (1)
|
|
{
|
|
_Unwind_FrameState fs;
|
|
int match_handler;
|
|
|
|
code = uw_frame_state_for (context, &fs);
|
|
|
|
/* Identify when we've reached the designated handler context. */
|
|
match_handler = (uw_identify_context (context) == exc->private_2
|
|
? _UA_HANDLER_FRAME : 0);
|
|
|
|
if (code != _URC_NO_REASON)
|
|
/* Some error encountered. Usually the unwinder doesn't
|
|
diagnose these and merely crashes. */
|
|
return _URC_FATAL_PHASE2_ERROR;
|
|
|
|
/* Unwind successful. Run the personality routine, if any. */
|
|
if (fs.personality)
|
|
{
|
|
code = (*fs.personality) (1, _UA_CLEANUP_PHASE | match_handler,
|
|
exc->exception_class, exc, context);
|
|
if (code == _URC_INSTALL_CONTEXT)
|
|
break;
|
|
if (code != _URC_CONTINUE_UNWIND)
|
|
return _URC_FATAL_PHASE2_ERROR;
|
|
}
|
|
|
|
/* Don't let us unwind past the handler context. */
|
|
gcc_assert (!match_handler);
|
|
|
|
uw_update_context (context, &fs);
|
|
_Unwind_Frames_Increment (context, frames);
|
|
}
|
|
|
|
*frames_p = frames;
|
|
return code;
|
|
}
|
|
|
|
/* Raise an exception, passing along the given exception object. */
|
|
|
|
_Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE
|
|
_Unwind_RaiseException(struct _Unwind_Exception *exc)
|
|
{
|
|
struct _Unwind_Context this_context, cur_context;
|
|
_Unwind_Reason_Code code;
|
|
unsigned long frames;
|
|
|
|
/* Set up this_context to describe the current stack frame. */
|
|
uw_init_context (&this_context);
|
|
cur_context = this_context;
|
|
|
|
/* Phase 1: Search. Unwind the stack, calling the personality routine
|
|
with the _UA_SEARCH_PHASE flag set. Do not modify the stack yet. */
|
|
while (1)
|
|
{
|
|
_Unwind_FrameState fs;
|
|
|
|
/* Set up fs to describe the FDE for the caller of cur_context. The
|
|
first time through the loop, that means __cxa_throw. */
|
|
code = uw_frame_state_for (&cur_context, &fs);
|
|
|
|
if (code == _URC_END_OF_STACK)
|
|
/* Hit end of stack with no handler found. */
|
|
return _URC_END_OF_STACK;
|
|
|
|
if (code != _URC_NO_REASON)
|
|
/* Some error encountered. Usually the unwinder doesn't
|
|
diagnose these and merely crashes. */
|
|
return _URC_FATAL_PHASE1_ERROR;
|
|
|
|
/* Unwind successful. Run the personality routine, if any. */
|
|
if (fs.personality)
|
|
{
|
|
code = (*fs.personality) (1, _UA_SEARCH_PHASE, exc->exception_class,
|
|
exc, &cur_context);
|
|
if (code == _URC_HANDLER_FOUND)
|
|
break;
|
|
else if (code != _URC_CONTINUE_UNWIND)
|
|
return _URC_FATAL_PHASE1_ERROR;
|
|
}
|
|
|
|
/* Update cur_context to describe the same frame as fs. */
|
|
uw_update_context (&cur_context, &fs);
|
|
}
|
|
|
|
/* Indicate to _Unwind_Resume and associated subroutines that this
|
|
is not a forced unwind. Further, note where we found a handler. */
|
|
exc->private_1 = 0;
|
|
exc->private_2 = uw_identify_context (&cur_context);
|
|
|
|
cur_context = this_context;
|
|
code = _Unwind_RaiseException_Phase2 (exc, &cur_context, &frames);
|
|
if (code != _URC_INSTALL_CONTEXT)
|
|
return code;
|
|
|
|
uw_install_context (&this_context, &cur_context, frames);
|
|
}
|
|
|
|
|
|
/* Subroutine of _Unwind_ForcedUnwind also invoked from _Unwind_Resume. */
|
|
|
|
static _Unwind_Reason_Code
|
|
_Unwind_ForcedUnwind_Phase2 (struct _Unwind_Exception *exc,
|
|
struct _Unwind_Context *context,
|
|
unsigned long *frames_p)
|
|
{
|
|
_Unwind_Stop_Fn stop = (_Unwind_Stop_Fn) (_Unwind_Ptr) exc->private_1;
|
|
void *stop_argument = (void *) (_Unwind_Ptr) exc->private_2;
|
|
_Unwind_Reason_Code code, stop_code;
|
|
unsigned long frames = 1;
|
|
|
|
while (1)
|
|
{
|
|
_Unwind_FrameState fs;
|
|
int action;
|
|
|
|
/* Set up fs to describe the FDE for the caller of cur_context. */
|
|
code = uw_frame_state_for (context, &fs);
|
|
if (code != _URC_NO_REASON && code != _URC_END_OF_STACK
|
|
&& code != _URC_NORMAL_STOP)
|
|
return _URC_FATAL_PHASE2_ERROR;
|
|
|
|
/* Unwind successful. */
|
|
action = _UA_FORCE_UNWIND | _UA_CLEANUP_PHASE;
|
|
if (code == _URC_END_OF_STACK || code == _URC_NORMAL_STOP)
|
|
action |= _UA_END_OF_STACK;
|
|
stop_code = (*stop) (1, action, exc->exception_class, exc,
|
|
context, stop_argument);
|
|
if (stop_code != _URC_NO_REASON)
|
|
return _URC_FATAL_PHASE2_ERROR;
|
|
|
|
/* Stop didn't want to do anything. Invoke the personality
|
|
handler, if applicable, to run cleanups. */
|
|
if (code == _URC_END_OF_STACK)
|
|
break;
|
|
|
|
if (fs.personality)
|
|
{
|
|
code = (*fs.personality) (1, _UA_FORCE_UNWIND | _UA_CLEANUP_PHASE,
|
|
exc->exception_class, exc, context);
|
|
if (code == _URC_INSTALL_CONTEXT)
|
|
break;
|
|
if (code != _URC_CONTINUE_UNWIND)
|
|
return _URC_FATAL_PHASE2_ERROR;
|
|
}
|
|
|
|
/* Update cur_context to describe the same frame as fs, and discard
|
|
the previous context if necessary. */
|
|
uw_advance_context (context, &fs);
|
|
_Unwind_Frames_Increment (context, frames);
|
|
}
|
|
|
|
*frames_p = frames;
|
|
return code;
|
|
}
|
|
|
|
|
|
/* Raise an exception for forced unwinding. */
|
|
|
|
_Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE
|
|
_Unwind_ForcedUnwind (struct _Unwind_Exception *exc,
|
|
_Unwind_Stop_Fn stop, void * stop_argument)
|
|
{
|
|
struct _Unwind_Context this_context, cur_context;
|
|
_Unwind_Reason_Code code;
|
|
unsigned long frames;
|
|
|
|
uw_init_context (&this_context);
|
|
cur_context = this_context;
|
|
|
|
exc->private_1 = (_Unwind_Ptr) stop;
|
|
exc->private_2 = (_Unwind_Ptr) stop_argument;
|
|
|
|
code = _Unwind_ForcedUnwind_Phase2 (exc, &cur_context, &frames);
|
|
if (code != _URC_INSTALL_CONTEXT)
|
|
return code;
|
|
|
|
uw_install_context (&this_context, &cur_context, frames);
|
|
}
|
|
|
|
|
|
/* Resume propagation of an existing exception. This is used after
|
|
e.g. executing cleanup code, and not to implement rethrowing. */
|
|
|
|
void LIBGCC2_UNWIND_ATTRIBUTE
|
|
_Unwind_Resume (struct _Unwind_Exception *exc)
|
|
{
|
|
struct _Unwind_Context this_context, cur_context;
|
|
_Unwind_Reason_Code code;
|
|
unsigned long frames;
|
|
|
|
uw_init_context (&this_context);
|
|
cur_context = this_context;
|
|
|
|
/* Choose between continuing to process _Unwind_RaiseException
|
|
or _Unwind_ForcedUnwind. */
|
|
if (exc->private_1 == 0)
|
|
code = _Unwind_RaiseException_Phase2 (exc, &cur_context, &frames);
|
|
else
|
|
code = _Unwind_ForcedUnwind_Phase2 (exc, &cur_context, &frames);
|
|
|
|
gcc_assert (code == _URC_INSTALL_CONTEXT);
|
|
|
|
uw_install_context (&this_context, &cur_context, frames);
|
|
}
|
|
|
|
|
|
/* Resume propagation of an FORCE_UNWIND exception, or to rethrow
|
|
a normal exception that was handled. */
|
|
|
|
_Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE
|
|
_Unwind_Resume_or_Rethrow (struct _Unwind_Exception *exc)
|
|
{
|
|
struct _Unwind_Context this_context, cur_context;
|
|
_Unwind_Reason_Code code;
|
|
unsigned long frames;
|
|
|
|
/* Choose between continuing to process _Unwind_RaiseException
|
|
or _Unwind_ForcedUnwind. */
|
|
if (exc->private_1 == 0)
|
|
return _Unwind_RaiseException (exc);
|
|
|
|
uw_init_context (&this_context);
|
|
cur_context = this_context;
|
|
|
|
code = _Unwind_ForcedUnwind_Phase2 (exc, &cur_context, &frames);
|
|
|
|
gcc_assert (code == _URC_INSTALL_CONTEXT);
|
|
|
|
uw_install_context (&this_context, &cur_context, frames);
|
|
}
|
|
|
|
|
|
/* A convenience function that calls the exception_cleanup field. */
|
|
|
|
void
|
|
_Unwind_DeleteException (struct _Unwind_Exception *exc)
|
|
{
|
|
if (exc->exception_cleanup)
|
|
(*exc->exception_cleanup) (_URC_FOREIGN_EXCEPTION_CAUGHT, exc);
|
|
}
|
|
|
|
|
|
/* Perform stack backtrace through unwind data. */
|
|
|
|
_Unwind_Reason_Code LIBGCC2_UNWIND_ATTRIBUTE
|
|
_Unwind_Backtrace(_Unwind_Trace_Fn trace, void * trace_argument)
|
|
{
|
|
struct _Unwind_Context context;
|
|
_Unwind_Reason_Code code;
|
|
|
|
uw_init_context (&context);
|
|
|
|
while (1)
|
|
{
|
|
_Unwind_FrameState fs;
|
|
|
|
/* Set up fs to describe the FDE for the caller of context. */
|
|
code = uw_frame_state_for (&context, &fs);
|
|
if (code != _URC_NO_REASON && code != _URC_END_OF_STACK
|
|
&& code != _URC_NORMAL_STOP)
|
|
return _URC_FATAL_PHASE1_ERROR;
|
|
|
|
/* Call trace function. */
|
|
if ((*trace) (&context, trace_argument) != _URC_NO_REASON)
|
|
return _URC_FATAL_PHASE1_ERROR;
|
|
|
|
#ifdef MD_BACKCHAIN_FALLBACK
|
|
/* Do a backchain if there is no DWARF data. */
|
|
if (code == _URC_NORMAL_STOP)
|
|
{
|
|
MD_BACKCHAIN_FALLBACK(&context, trace_argument);
|
|
break;
|
|
}
|
|
#endif
|
|
|
|
/* We're done at end of stack. */
|
|
if (code == _URC_END_OF_STACK)
|
|
break;
|
|
|
|
/* Update context to describe the same frame as fs. */
|
|
uw_update_context (&context, &fs);
|
|
}
|
|
|
|
return code;
|
|
}
|