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Diffstat (limited to 'sysdeps/generic/unwind.inc')
| -rw-r--r-- | sysdeps/generic/unwind.inc | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/sysdeps/generic/unwind.inc b/sysdeps/generic/unwind.inc new file mode 100644 index 0000000..7ec65e9 --- /dev/null +++ b/sysdeps/generic/unwind.inc @@ -0,0 +1,309 @@ +/* Exception handling and frame unwind runtime interface routines. -*- C -*- + Copyright (C) 2001 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 2, 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. + + You should have received a copy of the GNU General Public License + along with GCC; see the file COPYING. If not, write to the Free + Software Foundation, 59 Temple Place - Suite 330, Boston, MA + 02111-1307, USA. */ + +/* 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 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) +{ + _Unwind_Reason_Code code; + + 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. */ + if (match_handler) + abort (); + + uw_update_context (context, &fs); + } + + return code; +} + +/* Raise an exception, passing along the given exception object. */ +#ifndef _LIBC +_Unwind_Reason_Code +_Unwind_RaiseException(struct _Unwind_Exception *exc) +{ + struct _Unwind_Context this_context, cur_context; + _Unwind_Reason_Code code; + + /* 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. Ususally 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); + if (code != _URC_INSTALL_CONTEXT) + return code; + + uw_install_context (&this_context, &cur_context); +} +#endif + + +/* Subroutine of _Unwind_ForcedUnwind also invoked from _Unwind_Resume. */ + +static _Unwind_Reason_Code +_Unwind_ForcedUnwind_Phase2(struct _Unwind_Exception *exc, + struct _Unwind_Context *context) +{ + _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; + + 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) + return _URC_FATAL_PHASE2_ERROR; + + /* Unwind successful. */ + action = _UA_FORCE_UNWIND | _UA_CLEANUP_PHASE; + if (code == _URC_END_OF_STACK) + 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. */ + uw_update_context (context, &fs); + } + + return code; +} + + +/* Raise an exception for forced unwinding. */ +#ifndef _LIBC +_Unwind_Reason_Code +_Unwind_ForcedUnwind (struct _Unwind_Exception *exc, + _Unwind_Stop_Fn stop, void * stop_argument) +{ + struct _Unwind_Context this_context, cur_context; + _Unwind_Reason_Code code; + + 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); + if (code != _URC_INSTALL_CONTEXT) + return code; + + uw_install_context (&this_context, &cur_context); +} +#endif + + +/* Resume propagation of an existing exception. This is used after + e.g. executing cleanup code, and not to implement rethrowing. */ + +void +_Unwind_Resume (struct _Unwind_Exception *exc) +{ + struct _Unwind_Context this_context, cur_context; + _Unwind_Reason_Code code; + + 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); + else + code = _Unwind_ForcedUnwind_Phase2 (exc, &cur_context); + + if (code != _URC_INSTALL_CONTEXT) + abort (); + + uw_install_context (&this_context, &cur_context); +} + + +/* Resume propagation of an FORCE_UNWIND exception, or to rethrow + a normal exception that was handled. */ +#ifndef _LIBC +_Unwind_Reason_Code +_Unwind_Resume_or_Rethrow (struct _Unwind_Exception *exc) +{ + struct _Unwind_Context this_context, cur_context; + _Unwind_Reason_Code code; + + /* 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); + + if (code != _URC_INSTALL_CONTEXT) + abort (); + + uw_install_context (&this_context, &cur_context); +} +#endif + + +/* A convenience function that calls the exception_cleanup field. */ +#ifndef _LIBC +void +_Unwind_DeleteException (struct _Unwind_Exception *exc) +{ + if (exc->exception_cleanup) + (*exc->exception_cleanup) (_URC_FOREIGN_EXCEPTION_CAUGHT, exc); +} +#endif + + +/* Perform stack backtrace through unwind data. */ +#ifndef _LIBC +_Unwind_Reason_Code +_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) + return _URC_FATAL_PHASE1_ERROR; + + /* Call trace function. */ + if ((*trace) (&context, trace_argument) != _URC_NO_REASON) + return _URC_FATAL_PHASE1_ERROR; + + /* 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; +} +#endif |