297 lines
6.8 KiB
C
297 lines
6.8 KiB
C
/* DWARF2 exception handling and frame unwind runtime interface routines.
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Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002
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Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GCC is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
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License for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING. If not, write to the Free
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Software Foundation, 59 Temple Place - Suite 330, Boston, MA
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02111-1307, USA. */
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#include "tconfig.h"
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#include "tsystem.h"
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#include "unwind.h"
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#include "gthr.h"
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#ifdef __USING_SJLJ_EXCEPTIONS__
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#ifdef DONT_USE_BUILTIN_SETJMP
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#ifndef inhibit_libc
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#include <setjmp.h>
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#else
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typedef void *jmp_buf[JMP_BUF_SIZE];
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extern void longjmp(jmp_buf, int) __attribute__((noreturn));
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#endif
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#else
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#define setjmp __builtin_setjmp
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#define longjmp __builtin_longjmp
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#endif
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/* This structure is allocated on the stack of the target function.
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This must match the definition created in except.c:init_eh. */
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struct SjLj_Function_Context
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{
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/* This is the chain through all registered contexts. It is
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filled in by _Unwind_SjLj_Register. */
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struct SjLj_Function_Context *prev;
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/* This is assigned in by the target function before every call
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to the index of the call site in the lsda. It is assigned by
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the personality routine to the landing pad index. */
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int call_site;
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/* This is how data is returned from the personality routine to
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the target function's handler. */
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_Unwind_Word data[4];
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/* These are filled in once by the target function before any
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exceptions are expected to be handled. */
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_Unwind_Personality_Fn personality;
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void *lsda;
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#ifdef DONT_USE_BUILTIN_SETJMP
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/* We don't know what sort of alignment requirements the system
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jmp_buf has. We over estimated in except.c, and now we have
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to match that here just in case the system *didn't* have more
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restrictive requirements. */
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jmp_buf jbuf __attribute__((aligned));
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#else
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void *jbuf[];
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#endif
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};
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struct _Unwind_Context
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{
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struct SjLj_Function_Context *fc;
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};
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typedef struct
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{
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_Unwind_Personality_Fn personality;
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} _Unwind_FrameState;
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/* Manage the chain of registered function contexts. */
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/* Single threaded fallback chain. */
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static struct SjLj_Function_Context *fc_static;
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#if __GTHREADS
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static __gthread_key_t fc_key;
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static int use_fc_key = -1;
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static void
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fc_key_dtor (void *ptr)
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{
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__gthread_key_dtor (fc_key, ptr);
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}
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static void
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fc_key_init (void)
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{
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use_fc_key = __gthread_key_create (&fc_key, fc_key_dtor) == 0;
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}
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static void
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fc_key_init_once (void)
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{
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static __gthread_once_t once = __GTHREAD_ONCE_INIT;
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if (__gthread_once (&once, fc_key_init) != 0 || use_fc_key < 0)
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use_fc_key = 0;
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}
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#endif
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void
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_Unwind_SjLj_Register (struct SjLj_Function_Context *fc)
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{
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#if __GTHREADS
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if (use_fc_key < 0)
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fc_key_init_once ();
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if (use_fc_key)
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{
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fc->prev = __gthread_getspecific (fc_key);
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__gthread_setspecific (fc_key, fc);
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}
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else
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#endif
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{
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fc->prev = fc_static;
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fc_static = fc;
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}
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}
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static inline struct SjLj_Function_Context *
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_Unwind_SjLj_GetContext (void)
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{
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#if __GTHREADS
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if (use_fc_key < 0)
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fc_key_init_once ();
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if (use_fc_key)
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return __gthread_getspecific (fc_key);
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#endif
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return fc_static;
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}
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static inline void
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_Unwind_SjLj_SetContext (struct SjLj_Function_Context *fc)
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{
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#if __GTHREADS
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if (use_fc_key < 0)
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fc_key_init_once ();
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if (use_fc_key)
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__gthread_setspecific (fc_key, fc);
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else
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#endif
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fc_static = fc;
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}
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void
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_Unwind_SjLj_Unregister (struct SjLj_Function_Context *fc)
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{
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_Unwind_SjLj_SetContext (fc->prev);
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}
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/* Get/set the return data value at INDEX in CONTEXT. */
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_Unwind_Word
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_Unwind_GetGR (struct _Unwind_Context *context, int index)
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{
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return context->fc->data[index];
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}
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/* Get the value of the CFA as saved in CONTEXT. */
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_Unwind_Word
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_Unwind_GetCFA (struct _Unwind_Context *context)
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{
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/* ??? Ideally __builtin_setjmp places the CFA in the jmpbuf. */
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return NULL;
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}
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void
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_Unwind_SetGR (struct _Unwind_Context *context, int index, _Unwind_Word val)
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{
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context->fc->data[index] = val;
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}
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/* Get the call-site index as saved in CONTEXT. */
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_Unwind_Ptr
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_Unwind_GetIP (struct _Unwind_Context *context)
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{
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return context->fc->call_site + 1;
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}
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/* Set the return landing pad index in CONTEXT. */
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void
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_Unwind_SetIP (struct _Unwind_Context *context, _Unwind_Ptr val)
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{
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context->fc->call_site = val - 1;
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}
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void *
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_Unwind_GetLanguageSpecificData (struct _Unwind_Context *context)
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{
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return context->fc->lsda;
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}
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_Unwind_Ptr
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_Unwind_GetRegionStart (struct _Unwind_Context *context __attribute__((unused)) )
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{
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return 0;
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}
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void *
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_Unwind_FindEnclosingFunction (void *pc)
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{
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return NULL;
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}
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#ifndef __ia64__
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_Unwind_Ptr
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_Unwind_GetDataRelBase (struct _Unwind_Context *context __attribute__((unused)) )
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{
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return 0;
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}
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_Unwind_Ptr
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_Unwind_GetTextRelBase (struct _Unwind_Context *context __attribute__((unused)) )
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{
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return 0;
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}
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#endif
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static inline _Unwind_Reason_Code
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uw_frame_state_for (struct _Unwind_Context *context, _Unwind_FrameState *fs)
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{
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if (context->fc == NULL)
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{
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fs->personality = NULL;
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return _URC_END_OF_STACK;
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}
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else
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{
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fs->personality = context->fc->personality;
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return _URC_NO_REASON;
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}
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}
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static inline void
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uw_update_context (struct _Unwind_Context *context,
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_Unwind_FrameState *fs __attribute__((unused)) )
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{
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context->fc = context->fc->prev;
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}
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static inline void
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uw_init_context (struct _Unwind_Context *context)
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{
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context->fc = _Unwind_SjLj_GetContext ();
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}
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/* ??? There appear to be bugs in integrate.c wrt __builtin_longjmp and
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virtual-stack-vars. An inline version of this segfaults on SPARC. */
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#define uw_install_context(CURRENT, TARGET) \
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do \
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{ \
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_Unwind_SjLj_SetContext ((TARGET)->fc); \
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longjmp ((TARGET)->fc->jbuf, 1); \
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} \
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while (0)
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static inline _Unwind_Ptr
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uw_identify_context (struct _Unwind_Context *context)
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{
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return (_Unwind_Ptr) context->fc;
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}
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/* Play games with unwind symbols so that we can have call frame
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and sjlj symbols in the same shared library. Not that you can
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use them simultaneously... */
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#define _Unwind_RaiseException _Unwind_SjLj_RaiseException
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#define _Unwind_ForcedUnwind _Unwind_SjLj_ForcedUnwind
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#define _Unwind_Resume _Unwind_SjLj_Resume
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#define _Unwind_Resume_or_Rethrow _Unwind_SjLj_Resume_or_Rethrow
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#include "unwind.inc"
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#endif /* USING_SJLJ_EXCEPTIONS */
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