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51e623f241
Continuing the removal of the obsolete INTDEF / INTUSE mechanism, this patch replaces its use in unwind-dw2-fde.c with hidden_def and hidden_proto. Tested for x86. This patch does result in code generation differences (for some reason GCC decides to partition __register_frame_info_bases after the patch). [BZ #14132] * sysdeps/generic/unwind-dw2-fde.c (__register_frame_info_bases_internal): Do not declare. (__register_frame_info_table_bases_internal): Likewise. (__deregister_frame_info_bases_internal): Likewise. (__register_frame_info_bases): Declare and use hidden_proto before definition. Use hidden_def instead of INTDEF. (__register_frame_info_table_bases): Likewise. (__deregister_frame_info_bases): Likewise. (__register_frame_info): Do not use INTUSE. (__register_frame): Likewise. (__register_frame_info_table): Likewise. (__register_frame_table): Likewise. (__deregister_frame_info): Likewise. (__deregister_frame): Likewise.
1078 lines
27 KiB
C
1078 lines
27 KiB
C
/* Subroutines needed for unwinding stack frames for exception handling. */
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/* Copyright (C) 1997-2014 Free Software Foundation, Inc.
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Contributed by Jason Merrill <jason@cygnus.com>.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#ifdef _LIBC
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# include <shlib-compat.h>
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#endif
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#if !defined _LIBC || SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2_5)
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#ifdef _LIBC
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#include <stdlib.h>
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#include <string.h>
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#include <bits/libc-lock.h>
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#include <dwarf2.h>
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#include <unwind.h>
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#define NO_BASE_OF_ENCODED_VALUE
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#include <unwind-pe.h>
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#include <unwind-dw2-fde.h>
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#else
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#ifndef _Unwind_Find_FDE
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#include "tconfig.h"
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#include "tsystem.h"
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#include "dwarf2.h"
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#include "unwind.h"
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#define NO_BASE_OF_ENCODED_VALUE
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#include "unwind-pe.h"
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#include "unwind-dw2-fde.h"
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#include "gthr.h"
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#endif
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#endif
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/* The unseen_objects list contains objects that have been registered
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but not yet categorized in any way. The seen_objects list has had
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it's pc_begin and count fields initialized at minimum, and is sorted
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by decreasing value of pc_begin. */
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static struct object *unseen_objects;
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static struct object *seen_objects;
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#ifdef _LIBC
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__libc_lock_define_initialized (static, object_mutex)
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#define init_object_mutex_once()
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#define __gthread_mutex_lock(m) __libc_lock_lock (*(m))
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#define __gthread_mutex_unlock(m) __libc_lock_unlock (*(m))
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void __register_frame_info_bases (void *begin, struct object *ob,
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void *tbase, void *dbase);
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hidden_proto (__register_frame_info_bases)
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void __register_frame_info_table_bases (void *begin,
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struct object *ob,
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void *tbase, void *dbase);
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hidden_proto (__register_frame_info_table_bases)
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void *__deregister_frame_info_bases (void *begin);
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hidden_proto (__deregister_frame_info_bases)
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#else
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#ifdef __GTHREAD_MUTEX_INIT
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static __gthread_mutex_t object_mutex = __GTHREAD_MUTEX_INIT;
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#else
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static __gthread_mutex_t object_mutex;
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#endif
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#ifdef __GTHREAD_MUTEX_INIT_FUNCTION
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static void
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init_object_mutex (void)
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{
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__GTHREAD_MUTEX_INIT_FUNCTION (&object_mutex);
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}
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static void
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init_object_mutex_once (void)
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{
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static __gthread_once_t once = __GTHREAD_ONCE_INIT;
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__gthread_once (&once, init_object_mutex);
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}
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#else
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#define init_object_mutex_once()
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#endif
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#endif /* _LIBC */
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/* Called from crtbegin.o to register the unwind info for an object. */
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void
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__register_frame_info_bases (void *begin, struct object *ob,
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void *tbase, void *dbase)
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{
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/* If .eh_frame is empty, don't register at all. */
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if (*(uword *) begin == 0)
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return;
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ob->pc_begin = (void *)-1;
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ob->tbase = tbase;
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ob->dbase = dbase;
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ob->u.single = begin;
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ob->s.i = 0;
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ob->s.b.encoding = DW_EH_PE_omit;
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#ifdef DWARF2_OBJECT_END_PTR_EXTENSION
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ob->fde_end = NULL;
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#endif
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init_object_mutex_once ();
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__gthread_mutex_lock (&object_mutex);
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ob->next = unseen_objects;
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unseen_objects = ob;
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__gthread_mutex_unlock (&object_mutex);
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}
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hidden_def (__register_frame_info_bases)
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void
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__register_frame_info (void *begin, struct object *ob)
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{
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__register_frame_info_bases (begin, ob, 0, 0);
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}
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void
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__register_frame (void *begin)
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{
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struct object *ob;
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/* If .eh_frame is empty, don't register at all. */
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if (*(uword *) begin == 0)
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return;
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ob = (struct object *) malloc (sizeof (struct object));
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__register_frame_info_bases (begin, ob, 0, 0);
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}
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/* Similar, but BEGIN is actually a pointer to a table of unwind entries
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for different translation units. Called from the file generated by
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collect2. */
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void
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__register_frame_info_table_bases (void *begin, struct object *ob,
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void *tbase, void *dbase)
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{
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ob->pc_begin = (void *)-1;
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ob->tbase = tbase;
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ob->dbase = dbase;
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ob->u.array = begin;
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ob->s.i = 0;
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ob->s.b.from_array = 1;
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ob->s.b.encoding = DW_EH_PE_omit;
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init_object_mutex_once ();
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__gthread_mutex_lock (&object_mutex);
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ob->next = unseen_objects;
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unseen_objects = ob;
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__gthread_mutex_unlock (&object_mutex);
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}
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hidden_def (__register_frame_info_table_bases)
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void
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__register_frame_info_table (void *begin, struct object *ob)
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{
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__register_frame_info_table_bases (begin, ob, 0, 0);
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}
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void
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__register_frame_table (void *begin)
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{
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struct object *ob = (struct object *) malloc (sizeof (struct object));
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__register_frame_info_table_bases (begin, ob, 0, 0);
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}
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/* Called from crtbegin.o to deregister the unwind info for an object. */
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/* ??? Glibc has for a while now exported __register_frame_info and
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__deregister_frame_info. If we call __register_frame_info_bases
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from crtbegin (wherein it is declared weak), and this object does
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not get pulled from libgcc.a for other reasons, then the
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invocation of __deregister_frame_info will be resolved from glibc.
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Since the registration did not happen there, we'll abort.
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Therefore, declare a new deregistration entry point that does the
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exact same thing, but will resolve to the same library as
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implements __register_frame_info_bases. */
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void *
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__deregister_frame_info_bases (void *begin)
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{
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struct object **p;
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struct object *ob = 0;
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/* If .eh_frame is empty, we haven't registered. */
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if (*(uword *) begin == 0)
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return ob;
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init_object_mutex_once ();
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__gthread_mutex_lock (&object_mutex);
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for (p = &unseen_objects; *p ; p = &(*p)->next)
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if ((*p)->u.single == begin)
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{
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ob = *p;
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*p = ob->next;
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goto out;
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}
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for (p = &seen_objects; *p ; p = &(*p)->next)
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if ((*p)->s.b.sorted)
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{
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if ((*p)->u.sort->orig_data == begin)
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{
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ob = *p;
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*p = ob->next;
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free (ob->u.sort);
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goto out;
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}
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}
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else
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{
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if ((*p)->u.single == begin)
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{
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ob = *p;
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*p = ob->next;
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goto out;
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}
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}
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__gthread_mutex_unlock (&object_mutex);
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abort ();
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out:
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__gthread_mutex_unlock (&object_mutex);
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return (void *) ob;
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}
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hidden_def (__deregister_frame_info_bases)
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void *
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__deregister_frame_info (void *begin)
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{
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return __deregister_frame_info_bases (begin);
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}
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void
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__deregister_frame (void *begin)
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{
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/* If .eh_frame is empty, we haven't registered. */
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if (*(uword *) begin != 0)
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free (__deregister_frame_info_bases (begin));
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}
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/* Like base_of_encoded_value, but take the base from a struct object
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instead of an _Unwind_Context. */
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static _Unwind_Ptr
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base_from_object (unsigned char encoding, struct object *ob)
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{
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if (encoding == DW_EH_PE_omit)
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return 0;
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switch (encoding & 0x70)
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{
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case DW_EH_PE_absptr:
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case DW_EH_PE_pcrel:
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case DW_EH_PE_aligned:
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return 0;
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case DW_EH_PE_textrel:
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return (_Unwind_Ptr) ob->tbase;
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case DW_EH_PE_datarel:
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return (_Unwind_Ptr) ob->dbase;
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}
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abort ();
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}
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/* Return the FDE pointer encoding from the CIE. */
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/* ??? This is a subset of extract_cie_info from unwind-dw2.c. */
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static int
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get_cie_encoding (struct dwarf_cie *cie)
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{
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const unsigned char *aug, *p;
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_Unwind_Ptr dummy;
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_Unwind_Word utmp;
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_Unwind_Sword stmp;
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aug = cie->augmentation;
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if (aug[0] != 'z')
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return DW_EH_PE_absptr;
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/* Skip the augmentation string. */
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p = aug + strlen ((const char *) aug) + 1;
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p = read_uleb128 (p, &utmp); /* Skip code alignment. */
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p = read_sleb128 (p, &stmp); /* Skip data alignment. */
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p++; /* Skip return address column. */
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aug++; /* Skip 'z' */
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p = read_uleb128 (p, &utmp); /* Skip augmentation length. */
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while (1)
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{
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/* This is what we're looking for. */
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if (*aug == 'R')
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return *p;
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/* Personality encoding and pointer. */
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else if (*aug == 'P')
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{
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/* ??? Avoid dereferencing indirect pointers, since we're
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faking the base address. Gotta keep DW_EH_PE_aligned
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intact, however. */
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p = read_encoded_value_with_base (*p & 0x7F, 0, p + 1, &dummy);
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}
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/* LSDA encoding. */
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else if (*aug == 'L')
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p++;
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/* Otherwise end of string, or unknown augmentation. */
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else
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return DW_EH_PE_absptr;
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aug++;
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}
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}
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static inline int
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get_fde_encoding (struct dwarf_fde *f)
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{
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return get_cie_encoding (get_cie (f));
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}
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/* Sorting an array of FDEs by address.
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(Ideally we would have the linker sort the FDEs so we don't have to do
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it at run time. But the linkers are not yet prepared for this.) */
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/* Return the Nth pc_begin value from FDE x. */
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static inline _Unwind_Ptr
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get_pc_begin (fde *x, size_t n)
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{
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_Unwind_Ptr p;
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memcpy (&p, x->pc_begin + n * sizeof (_Unwind_Ptr), sizeof (_Unwind_Ptr));
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return p;
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}
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/* Comparison routines. Three variants of increasing complexity. */
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static int
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fde_unencoded_compare (struct object *ob __attribute__((unused)),
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fde *x, fde *y)
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{
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_Unwind_Ptr x_ptr = get_pc_begin (x, 0);
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_Unwind_Ptr y_ptr = get_pc_begin (y, 0);
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if (x_ptr > y_ptr)
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return 1;
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if (x_ptr < y_ptr)
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return -1;
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return 0;
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}
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static int
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fde_single_encoding_compare (struct object *ob, fde *x, fde *y)
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{
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_Unwind_Ptr base, x_ptr, y_ptr;
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base = base_from_object (ob->s.b.encoding, ob);
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read_encoded_value_with_base (ob->s.b.encoding, base, x->pc_begin, &x_ptr);
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read_encoded_value_with_base (ob->s.b.encoding, base, y->pc_begin, &y_ptr);
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if (x_ptr > y_ptr)
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return 1;
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if (x_ptr < y_ptr)
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return -1;
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return 0;
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}
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static int
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fde_mixed_encoding_compare (struct object *ob, fde *x, fde *y)
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{
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int x_encoding, y_encoding;
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_Unwind_Ptr x_ptr, y_ptr;
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x_encoding = get_fde_encoding (x);
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read_encoded_value_with_base (x_encoding, base_from_object (x_encoding, ob),
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x->pc_begin, &x_ptr);
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y_encoding = get_fde_encoding (y);
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read_encoded_value_with_base (y_encoding, base_from_object (y_encoding, ob),
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y->pc_begin, &y_ptr);
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if (x_ptr > y_ptr)
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return 1;
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if (x_ptr < y_ptr)
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return -1;
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return 0;
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}
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typedef int (*fde_compare_t) (struct object *, fde *, fde *);
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/* This is a special mix of insertion sort and heap sort, optimized for
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the data sets that actually occur. They look like
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101 102 103 127 128 105 108 110 190 111 115 119 125 160 126 129 130.
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I.e. a linearly increasing sequence (coming from functions in the text
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section), with additionally a few unordered elements (coming from functions
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in gnu_linkonce sections) whose values are higher than the values in the
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surrounding linear sequence (but not necessarily higher than the values
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at the end of the linear sequence!).
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The worst-case total run time is O(N) + O(n log (n)), where N is the
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total number of FDEs and n is the number of erratic ones. */
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struct fde_accumulator
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{
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struct fde_vector *linear;
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struct fde_vector *erratic;
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};
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static int
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start_fde_sort (struct fde_accumulator *accu, size_t count)
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{
|
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size_t size;
|
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if (! count)
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return 0;
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|
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size = sizeof (struct fde_vector) + sizeof (fde *) * count;
|
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if ((accu->linear = (struct fde_vector *) malloc (size)))
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{
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accu->linear->count = 0;
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if ((accu->erratic = (struct fde_vector *) malloc (size)))
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accu->erratic->count = 0;
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return 1;
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}
|
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else
|
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return 0;
|
||
}
|
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|
||
static inline void
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fde_insert (struct fde_accumulator *accu, fde *this_fde)
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{
|
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if (accu->linear)
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accu->linear->array[accu->linear->count++] = this_fde;
|
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}
|
||
|
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/* Split LINEAR into a linear sequence with low values and an erratic
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sequence with high values, put the linear one (of longest possible
|
||
length) into LINEAR and the erratic one into ERRATIC. This is O(N).
|
||
|
||
Because the longest linear sequence we are trying to locate within the
|
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incoming LINEAR array can be interspersed with (high valued) erratic
|
||
entries. We construct a chain indicating the sequenced entries.
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To avoid having to allocate this chain, we overlay it onto the space of
|
||
the ERRATIC array during construction. A final pass iterates over the
|
||
chain to determine what should be placed in the ERRATIC array, and
|
||
what is the linear sequence. This overlay is safe from aliasing. */
|
||
|
||
static void
|
||
fde_split (struct object *ob, fde_compare_t fde_compare,
|
||
struct fde_vector *linear, struct fde_vector *erratic)
|
||
{
|
||
static fde *marker;
|
||
size_t count = linear->count;
|
||
fde **chain_end = ▮
|
||
size_t i, j, k;
|
||
|
||
/* This should optimize out, but it is wise to make sure this assumption
|
||
is correct. Should these have different sizes, we cannot cast between
|
||
them and the overlaying onto ERRATIC will not work. */
|
||
if (sizeof (fde *) != sizeof (fde **))
|
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abort ();
|
||
|
||
for (i = 0; i < count; i++)
|
||
{
|
||
fde **probe;
|
||
|
||
for (probe = chain_end;
|
||
probe != &marker && fde_compare (ob, linear->array[i], *probe) < 0;
|
||
probe = chain_end)
|
||
{
|
||
chain_end = (fde **) erratic->array[probe - linear->array];
|
||
erratic->array[probe - linear->array] = NULL;
|
||
}
|
||
erratic->array[i] = (fde *) chain_end;
|
||
chain_end = &linear->array[i];
|
||
}
|
||
|
||
/* Each entry in LINEAR which is part of the linear sequence we have
|
||
discovered will correspond to a non-NULL entry in the chain we built in
|
||
the ERRATIC array. */
|
||
for (i = j = k = 0; i < count; i++)
|
||
if (erratic->array[i])
|
||
linear->array[j++] = linear->array[i];
|
||
else
|
||
erratic->array[k++] = linear->array[i];
|
||
linear->count = j;
|
||
erratic->count = k;
|
||
}
|
||
|
||
/* This is O(n log(n)). BSD/OS defines heapsort in stdlib.h, so we must
|
||
use a name that does not conflict. */
|
||
|
||
static void
|
||
frame_heapsort (struct object *ob, fde_compare_t fde_compare,
|
||
struct fde_vector *erratic)
|
||
{
|
||
/* For a description of this algorithm, see:
|
||
Samuel P. Harbison, Guy L. Steele Jr.: C, a reference manual, 2nd ed.,
|
||
p. 60-61. */
|
||
fde ** a = erratic->array;
|
||
/* A portion of the array is called a "heap" if for all i>=0:
|
||
If i and 2i+1 are valid indices, then a[i] >= a[2i+1].
|
||
If i and 2i+2 are valid indices, then a[i] >= a[2i+2]. */
|
||
#define SWAP(x,y) do { fde * tmp = x; x = y; y = tmp; } while (0)
|
||
size_t n = erratic->count;
|
||
size_t m = n;
|
||
size_t i;
|
||
|
||
while (m > 0)
|
||
{
|
||
/* Invariant: a[m..n-1] is a heap. */
|
||
m--;
|
||
for (i = m; 2*i+1 < n; )
|
||
{
|
||
if (2*i+2 < n
|
||
&& fde_compare (ob, a[2*i+2], a[2*i+1]) > 0
|
||
&& fde_compare (ob, a[2*i+2], a[i]) > 0)
|
||
{
|
||
SWAP (a[i], a[2*i+2]);
|
||
i = 2*i+2;
|
||
}
|
||
else if (fde_compare (ob, a[2*i+1], a[i]) > 0)
|
||
{
|
||
SWAP (a[i], a[2*i+1]);
|
||
i = 2*i+1;
|
||
}
|
||
else
|
||
break;
|
||
}
|
||
}
|
||
while (n > 1)
|
||
{
|
||
/* Invariant: a[0..n-1] is a heap. */
|
||
n--;
|
||
SWAP (a[0], a[n]);
|
||
for (i = 0; 2*i+1 < n; )
|
||
{
|
||
if (2*i+2 < n
|
||
&& fde_compare (ob, a[2*i+2], a[2*i+1]) > 0
|
||
&& fde_compare (ob, a[2*i+2], a[i]) > 0)
|
||
{
|
||
SWAP (a[i], a[2*i+2]);
|
||
i = 2*i+2;
|
||
}
|
||
else if (fde_compare (ob, a[2*i+1], a[i]) > 0)
|
||
{
|
||
SWAP (a[i], a[2*i+1]);
|
||
i = 2*i+1;
|
||
}
|
||
else
|
||
break;
|
||
}
|
||
}
|
||
#undef SWAP
|
||
}
|
||
|
||
/* Merge V1 and V2, both sorted, and put the result into V1. */
|
||
static void
|
||
fde_merge (struct object *ob, fde_compare_t fde_compare,
|
||
struct fde_vector *v1, struct fde_vector *v2)
|
||
{
|
||
size_t i1, i2;
|
||
fde * fde2;
|
||
|
||
i2 = v2->count;
|
||
if (i2 > 0)
|
||
{
|
||
i1 = v1->count;
|
||
do
|
||
{
|
||
i2--;
|
||
fde2 = v2->array[i2];
|
||
while (i1 > 0 && fde_compare (ob, v1->array[i1-1], fde2) > 0)
|
||
{
|
||
v1->array[i1+i2] = v1->array[i1-1];
|
||
i1--;
|
||
}
|
||
v1->array[i1+i2] = fde2;
|
||
}
|
||
while (i2 > 0);
|
||
v1->count += v2->count;
|
||
}
|
||
}
|
||
|
||
static void
|
||
end_fde_sort (struct object *ob, struct fde_accumulator *accu, size_t count)
|
||
{
|
||
fde_compare_t fde_compare;
|
||
|
||
if (accu->linear->count != count)
|
||
abort ();
|
||
|
||
if (ob->s.b.mixed_encoding)
|
||
fde_compare = fde_mixed_encoding_compare;
|
||
else if (ob->s.b.encoding == DW_EH_PE_absptr)
|
||
fde_compare = fde_unencoded_compare;
|
||
else
|
||
fde_compare = fde_single_encoding_compare;
|
||
|
||
if (accu->erratic)
|
||
{
|
||
fde_split (ob, fde_compare, accu->linear, accu->erratic);
|
||
if (accu->linear->count + accu->erratic->count != count)
|
||
abort ();
|
||
frame_heapsort (ob, fde_compare, accu->erratic);
|
||
fde_merge (ob, fde_compare, accu->linear, accu->erratic);
|
||
free (accu->erratic);
|
||
}
|
||
else
|
||
{
|
||
/* We've not managed to malloc an erratic array,
|
||
so heap sort in the linear one. */
|
||
frame_heapsort (ob, fde_compare, accu->linear);
|
||
}
|
||
}
|
||
|
||
|
||
/* Update encoding, mixed_encoding, and pc_begin for OB for the
|
||
fde array beginning at THIS_FDE. Return the number of fdes
|
||
encountered along the way. */
|
||
|
||
static size_t
|
||
classify_object_over_fdes (struct object *ob, fde *this_fde)
|
||
{
|
||
struct dwarf_cie *last_cie = 0;
|
||
size_t count = 0;
|
||
int encoding = DW_EH_PE_absptr;
|
||
_Unwind_Ptr base = 0;
|
||
|
||
for (; ! last_fde (ob, this_fde); this_fde = next_fde (this_fde))
|
||
{
|
||
struct dwarf_cie *this_cie;
|
||
_Unwind_Ptr mask, pc_begin;
|
||
|
||
/* Skip CIEs. */
|
||
if (this_fde->CIE_delta == 0)
|
||
continue;
|
||
|
||
/* Determine the encoding for this FDE. Note mixed encoded
|
||
objects for later. */
|
||
this_cie = get_cie (this_fde);
|
||
if (this_cie != last_cie)
|
||
{
|
||
last_cie = this_cie;
|
||
encoding = get_cie_encoding (this_cie);
|
||
base = base_from_object (encoding, ob);
|
||
if (ob->s.b.encoding == DW_EH_PE_omit)
|
||
ob->s.b.encoding = encoding;
|
||
else if (ob->s.b.encoding != encoding)
|
||
ob->s.b.mixed_encoding = 1;
|
||
}
|
||
|
||
read_encoded_value_with_base (encoding, base, this_fde->pc_begin,
|
||
&pc_begin);
|
||
|
||
/* Take care to ignore link-once functions that were removed.
|
||
In these cases, the function address will be NULL, but if
|
||
the encoding is smaller than a pointer a true NULL may not
|
||
be representable. Assume 0 in the representable bits is NULL. */
|
||
mask = size_of_encoded_value (encoding);
|
||
if (mask < sizeof (void *))
|
||
mask = (1L << (mask << 3)) - 1;
|
||
else
|
||
mask = -1;
|
||
|
||
if ((pc_begin & mask) == 0)
|
||
continue;
|
||
|
||
count += 1;
|
||
if ((void *) pc_begin < ob->pc_begin)
|
||
ob->pc_begin = (void *) pc_begin;
|
||
}
|
||
|
||
return count;
|
||
}
|
||
|
||
static void
|
||
add_fdes (struct object *ob, struct fde_accumulator *accu, fde *this_fde)
|
||
{
|
||
struct dwarf_cie *last_cie = 0;
|
||
int encoding = ob->s.b.encoding;
|
||
_Unwind_Ptr base = base_from_object (ob->s.b.encoding, ob);
|
||
|
||
for (; ! last_fde (ob, this_fde); this_fde = next_fde (this_fde))
|
||
{
|
||
struct dwarf_cie *this_cie;
|
||
|
||
/* Skip CIEs. */
|
||
if (this_fde->CIE_delta == 0)
|
||
continue;
|
||
|
||
if (ob->s.b.mixed_encoding)
|
||
{
|
||
/* Determine the encoding for this FDE. Note mixed encoded
|
||
objects for later. */
|
||
this_cie = get_cie (this_fde);
|
||
if (this_cie != last_cie)
|
||
{
|
||
last_cie = this_cie;
|
||
encoding = get_cie_encoding (this_cie);
|
||
base = base_from_object (encoding, ob);
|
||
}
|
||
}
|
||
|
||
if (encoding == DW_EH_PE_absptr)
|
||
{
|
||
if (get_pc_begin (this_fde, 0) == 0)
|
||
continue;
|
||
}
|
||
else
|
||
{
|
||
_Unwind_Ptr pc_begin, mask;
|
||
|
||
read_encoded_value_with_base (encoding, base, this_fde->pc_begin,
|
||
&pc_begin);
|
||
|
||
/* Take care to ignore link-once functions that were removed.
|
||
In these cases, the function address will be NULL, but if
|
||
the encoding is smaller than a pointer a true NULL may not
|
||
be representable. Assume 0 in the representable bits is NULL. */
|
||
mask = size_of_encoded_value (encoding);
|
||
if (mask < sizeof (void *))
|
||
mask = (1L << (mask << 3)) - 1;
|
||
else
|
||
mask = -1;
|
||
|
||
if ((pc_begin & mask) == 0)
|
||
continue;
|
||
}
|
||
|
||
fde_insert (accu, this_fde);
|
||
}
|
||
}
|
||
|
||
/* Set up a sorted array of pointers to FDEs for a loaded object. We
|
||
count up the entries before allocating the array because it's likely to
|
||
be faster. We can be called multiple times, should we have failed to
|
||
allocate a sorted fde array on a previous occasion. */
|
||
|
||
static void
|
||
init_object (struct object* ob)
|
||
{
|
||
struct fde_accumulator accu;
|
||
size_t count;
|
||
|
||
count = ob->s.b.count;
|
||
if (count == 0)
|
||
{
|
||
if (ob->s.b.from_array)
|
||
{
|
||
fde **p = ob->u.array;
|
||
for (count = 0; *p; ++p)
|
||
count += classify_object_over_fdes (ob, *p);
|
||
}
|
||
else
|
||
count = classify_object_over_fdes (ob, ob->u.single);
|
||
|
||
/* The count field we have in the main struct object is somewhat
|
||
limited, but should suffice for virtually all cases. If the
|
||
counted value doesn't fit, re-write a zero. The worst that
|
||
happens is that we re-count next time -- admittedly non-trivial
|
||
in that this implies some 2M fdes, but at least we function. */
|
||
ob->s.b.count = count;
|
||
if (ob->s.b.count != count)
|
||
ob->s.b.count = 0;
|
||
}
|
||
|
||
if (!start_fde_sort (&accu, count))
|
||
return;
|
||
|
||
if (ob->s.b.from_array)
|
||
{
|
||
fde **p;
|
||
for (p = ob->u.array; *p; ++p)
|
||
add_fdes (ob, &accu, *p);
|
||
}
|
||
else
|
||
add_fdes (ob, &accu, ob->u.single);
|
||
|
||
end_fde_sort (ob, &accu, count);
|
||
|
||
/* Save the original fde pointer, since this is the key by which the
|
||
DSO will deregister the object. */
|
||
accu.linear->orig_data = ob->u.single;
|
||
ob->u.sort = accu.linear;
|
||
|
||
ob->s.b.sorted = 1;
|
||
}
|
||
|
||
/* A linear search through a set of FDEs for the given PC. This is
|
||
used when there was insufficient memory to allocate and sort an
|
||
array. */
|
||
|
||
static fde *
|
||
linear_search_fdes (struct object *ob, fde *this_fde, void *pc)
|
||
{
|
||
struct dwarf_cie *last_cie = 0;
|
||
int encoding = ob->s.b.encoding;
|
||
_Unwind_Ptr base = base_from_object (ob->s.b.encoding, ob);
|
||
|
||
for (; ! last_fde (ob, this_fde); this_fde = next_fde (this_fde))
|
||
{
|
||
struct dwarf_cie *this_cie;
|
||
_Unwind_Ptr pc_begin, pc_range;
|
||
|
||
/* Skip CIEs. */
|
||
if (this_fde->CIE_delta == 0)
|
||
continue;
|
||
|
||
if (ob->s.b.mixed_encoding)
|
||
{
|
||
/* Determine the encoding for this FDE. Note mixed encoded
|
||
objects for later. */
|
||
this_cie = get_cie (this_fde);
|
||
if (this_cie != last_cie)
|
||
{
|
||
last_cie = this_cie;
|
||
encoding = get_cie_encoding (this_cie);
|
||
base = base_from_object (encoding, ob);
|
||
}
|
||
}
|
||
|
||
if (encoding == DW_EH_PE_absptr)
|
||
{
|
||
pc_begin = get_pc_begin (this_fde, 0);
|
||
pc_range = get_pc_begin (this_fde, 1);
|
||
if (pc_begin == 0)
|
||
continue;
|
||
}
|
||
else
|
||
{
|
||
_Unwind_Ptr mask;
|
||
const unsigned char *p;
|
||
|
||
p = read_encoded_value_with_base (encoding, base,
|
||
this_fde->pc_begin, &pc_begin);
|
||
read_encoded_value_with_base (encoding & 0x0F, 0, p, &pc_range);
|
||
|
||
/* Take care to ignore link-once functions that were removed.
|
||
In these cases, the function address will be NULL, but if
|
||
the encoding is smaller than a pointer a true NULL may not
|
||
be representable. Assume 0 in the representable bits is NULL. */
|
||
mask = size_of_encoded_value (encoding);
|
||
if (mask < sizeof (void *))
|
||
mask = (1L << (mask << 3)) - 1;
|
||
else
|
||
mask = -1;
|
||
|
||
if ((pc_begin & mask) == 0)
|
||
continue;
|
||
}
|
||
|
||
if ((_Unwind_Ptr) pc - pc_begin < pc_range)
|
||
return this_fde;
|
||
}
|
||
|
||
return NULL;
|
||
}
|
||
|
||
/* Binary search for an FDE containing the given PC. Here are three
|
||
implementations of increasing complexity. */
|
||
|
||
static fde *
|
||
binary_search_unencoded_fdes (struct object *ob, void *pc)
|
||
{
|
||
struct fde_vector *vec = ob->u.sort;
|
||
size_t lo, hi;
|
||
|
||
for (lo = 0, hi = vec->count; lo < hi; )
|
||
{
|
||
size_t i = (lo + hi) / 2;
|
||
fde *f = vec->array[i];
|
||
void *pc_begin;
|
||
uaddr pc_range;
|
||
|
||
pc_begin = (void *) get_pc_begin (f, 0);
|
||
pc_range = (uaddr) get_pc_begin (f, 1);
|
||
|
||
if (pc < pc_begin)
|
||
hi = i;
|
||
else if (pc >= pc_begin + pc_range)
|
||
lo = i + 1;
|
||
else
|
||
return f;
|
||
}
|
||
|
||
return NULL;
|
||
}
|
||
|
||
static fde *
|
||
binary_search_single_encoding_fdes (struct object *ob, void *pc)
|
||
{
|
||
struct fde_vector *vec = ob->u.sort;
|
||
int encoding = ob->s.b.encoding;
|
||
_Unwind_Ptr base = base_from_object (encoding, ob);
|
||
size_t lo, hi;
|
||
|
||
for (lo = 0, hi = vec->count; lo < hi; )
|
||
{
|
||
size_t i = (lo + hi) / 2;
|
||
fde *f = vec->array[i];
|
||
_Unwind_Ptr pc_begin, pc_range;
|
||
const unsigned char *p;
|
||
|
||
p = read_encoded_value_with_base (encoding, base, f->pc_begin,
|
||
&pc_begin);
|
||
read_encoded_value_with_base (encoding & 0x0F, 0, p, &pc_range);
|
||
|
||
if ((_Unwind_Ptr) pc < pc_begin)
|
||
hi = i;
|
||
else if ((_Unwind_Ptr) pc >= pc_begin + pc_range)
|
||
lo = i + 1;
|
||
else
|
||
return f;
|
||
}
|
||
|
||
return NULL;
|
||
}
|
||
|
||
static fde *
|
||
binary_search_mixed_encoding_fdes (struct object *ob, void *pc)
|
||
{
|
||
struct fde_vector *vec = ob->u.sort;
|
||
size_t lo, hi;
|
||
|
||
for (lo = 0, hi = vec->count; lo < hi; )
|
||
{
|
||
size_t i = (lo + hi) / 2;
|
||
fde *f = vec->array[i];
|
||
_Unwind_Ptr pc_begin, pc_range;
|
||
const unsigned char *p;
|
||
int encoding;
|
||
|
||
encoding = get_fde_encoding (f);
|
||
p = read_encoded_value_with_base (encoding,
|
||
base_from_object (encoding, ob),
|
||
f->pc_begin, &pc_begin);
|
||
read_encoded_value_with_base (encoding & 0x0F, 0, p, &pc_range);
|
||
|
||
if ((_Unwind_Ptr) pc < pc_begin)
|
||
hi = i;
|
||
else if ((_Unwind_Ptr) pc >= pc_begin + pc_range)
|
||
lo = i + 1;
|
||
else
|
||
return f;
|
||
}
|
||
|
||
return NULL;
|
||
}
|
||
|
||
static fde *
|
||
search_object (struct object* ob, void *pc)
|
||
{
|
||
/* If the data hasn't been sorted, try to do this now. We may have
|
||
more memory available than last time we tried. */
|
||
if (! ob->s.b.sorted)
|
||
{
|
||
init_object (ob);
|
||
|
||
/* Despite the above comment, the normal reason to get here is
|
||
that we've not processed this object before. A quick range
|
||
check is in order. */
|
||
if (pc < ob->pc_begin)
|
||
return NULL;
|
||
}
|
||
|
||
if (ob->s.b.sorted)
|
||
{
|
||
if (ob->s.b.mixed_encoding)
|
||
return binary_search_mixed_encoding_fdes (ob, pc);
|
||
else if (ob->s.b.encoding == DW_EH_PE_absptr)
|
||
return binary_search_unencoded_fdes (ob, pc);
|
||
else
|
||
return binary_search_single_encoding_fdes (ob, pc);
|
||
}
|
||
else
|
||
{
|
||
/* Long slow labourious linear search, cos we've no memory. */
|
||
if (ob->s.b.from_array)
|
||
{
|
||
fde **p;
|
||
for (p = ob->u.array; *p ; p++)
|
||
{
|
||
fde *f = linear_search_fdes (ob, *p, pc);
|
||
if (f)
|
||
return f;
|
||
}
|
||
return NULL;
|
||
}
|
||
else
|
||
return linear_search_fdes (ob, ob->u.single, pc);
|
||
}
|
||
}
|
||
|
||
fde *
|
||
_Unwind_Find_FDE (void *pc, struct dwarf_eh_bases *bases)
|
||
{
|
||
struct object *ob;
|
||
fde *f = NULL;
|
||
|
||
init_object_mutex_once ();
|
||
__gthread_mutex_lock (&object_mutex);
|
||
|
||
/* Linear search through the classified objects, to find the one
|
||
containing the pc. Note that pc_begin is sorted descending, and
|
||
we expect objects to be non-overlapping. */
|
||
for (ob = seen_objects; ob; ob = ob->next)
|
||
if (pc >= ob->pc_begin)
|
||
{
|
||
f = search_object (ob, pc);
|
||
if (f)
|
||
goto fini;
|
||
break;
|
||
}
|
||
|
||
/* Classify and search the objects we've not yet processed. */
|
||
while ((ob = unseen_objects))
|
||
{
|
||
struct object **p;
|
||
|
||
unseen_objects = ob->next;
|
||
f = search_object (ob, pc);
|
||
|
||
/* Insert the object into the classified list. */
|
||
for (p = &seen_objects; *p ; p = &(*p)->next)
|
||
if ((*p)->pc_begin < ob->pc_begin)
|
||
break;
|
||
ob->next = *p;
|
||
*p = ob;
|
||
|
||
if (f)
|
||
goto fini;
|
||
}
|
||
|
||
fini:
|
||
__gthread_mutex_unlock (&object_mutex);
|
||
|
||
if (f)
|
||
{
|
||
int encoding;
|
||
_Unwind_Ptr func;
|
||
|
||
bases->tbase = ob->tbase;
|
||
bases->dbase = ob->dbase;
|
||
|
||
encoding = ob->s.b.encoding;
|
||
if (ob->s.b.mixed_encoding)
|
||
encoding = get_fde_encoding (f);
|
||
read_encoded_value_with_base (encoding, base_from_object (encoding, ob),
|
||
f->pc_begin, &func);
|
||
bases->func = (void *) func;
|
||
}
|
||
|
||
return f;
|
||
}
|
||
|
||
#endif
|