390 lines
11 KiB
C
390 lines
11 KiB
C
/* Frame unwinder for frames using the libunwind library.
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Copyright 2003, 2004 Free Software Foundation, Inc.
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Written by Jeff Johnston, contributed by Red Hat Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program 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
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GNU General Public 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 this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "defs.h"
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#include "inferior.h"
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#include "frame.h"
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#include "frame-base.h"
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#include "frame-unwind.h"
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#include "gdbcore.h"
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#include "gdbtypes.h"
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#include "symtab.h"
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#include "objfiles.h"
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#include "regcache.h"
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#include <dlfcn.h>
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#include "gdb_assert.h"
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#include "gdb_string.h"
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#include "libunwind-frame.h"
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#include "complaints.h"
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static int libunwind_initialized;
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static struct gdbarch_data *libunwind_descr_handle;
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#ifndef LIBUNWIND_SO
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#define LIBUNWIND_SO "libunwind.so"
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#endif
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/* Required function pointers from libunwind. */
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static int (*unw_get_reg_p) (unw_cursor_t *, unw_regnum_t, unw_word_t *);
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static int (*unw_get_fpreg_p) (unw_cursor_t *, unw_regnum_t, unw_fpreg_t *);
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static int (*unw_get_saveloc_p) (unw_cursor_t *, unw_regnum_t, unw_save_loc_t *);
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static int (*unw_step_p) (unw_cursor_t *);
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static int (*unw_init_remote_p) (unw_cursor_t *, unw_addr_space_t, void *);
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static unw_addr_space_t (*unw_create_addr_space_p) (unw_accessors_t *, int);
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static int (*unw_search_unwind_table_p) (unw_addr_space_t, unw_word_t, unw_dyn_info_t *,
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unw_proc_info_t *, int, void *);
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static unw_word_t (*unw_find_dyn_list_p) (unw_addr_space_t, unw_dyn_info_t *,
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void *);
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struct libunwind_frame_cache
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{
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CORE_ADDR base;
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CORE_ADDR func_addr;
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unw_cursor_t cursor;
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};
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/* We need to qualify the function names with a platform-specific prefix to match
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the names used by the libunwind library. The UNW_OBJ macro is provided by the
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libunwind.h header file. */
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#define STRINGIFY2(name) #name
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#define STRINGIFY(name) STRINGIFY2(name)
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static char *get_reg_name = STRINGIFY(UNW_OBJ(get_reg));
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static char *get_fpreg_name = STRINGIFY(UNW_OBJ(get_fpreg));
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static char *get_saveloc_name = STRINGIFY(UNW_OBJ(get_save_loc));
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static char *step_name = STRINGIFY(UNW_OBJ(step));
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static char *init_remote_name = STRINGIFY(UNW_OBJ(init_remote));
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static char *create_addr_space_name = STRINGIFY(UNW_OBJ(create_addr_space));
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static char *search_unwind_table_name = STRINGIFY(UNW_OBJ(search_unwind_table));
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static char *find_dyn_list_name = STRINGIFY(UNW_OBJ(find_dyn_list));
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static struct libunwind_descr *
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libunwind_descr (struct gdbarch *gdbarch)
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{
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return gdbarch_data (gdbarch, libunwind_descr_handle);
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}
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static void *
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libunwind_descr_init (struct gdbarch *gdbarch)
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{
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struct libunwind_descr *descr = GDBARCH_OBSTACK_ZALLOC (gdbarch,
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struct libunwind_descr);
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return descr;
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}
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void
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libunwind_frame_set_descr (struct gdbarch *gdbarch, struct libunwind_descr *descr)
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{
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struct libunwind_descr *arch_descr;
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gdb_assert (gdbarch != NULL);
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arch_descr = gdbarch_data (gdbarch, libunwind_descr_handle);
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if (arch_descr == NULL)
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{
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/* First time here. Must initialize data area. */
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arch_descr = libunwind_descr_init (gdbarch);
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deprecated_set_gdbarch_data (gdbarch, libunwind_descr_handle, arch_descr);
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}
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/* Copy new descriptor info into arch descriptor. */
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arch_descr->gdb2uw = descr->gdb2uw;
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arch_descr->uw2gdb = descr->uw2gdb;
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arch_descr->is_fpreg = descr->is_fpreg;
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arch_descr->accessors = descr->accessors;
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}
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static struct libunwind_frame_cache *
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libunwind_frame_cache (struct frame_info *next_frame, void **this_cache)
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{
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unw_accessors_t *acc;
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unw_addr_space_t as;
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unw_word_t fp;
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unw_regnum_t uw_sp_regnum;
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struct libunwind_frame_cache *cache;
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struct libunwind_descr *descr;
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int i, ret;
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if (*this_cache)
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return *this_cache;
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/* Allocate a new cache. */
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cache = FRAME_OBSTACK_ZALLOC (struct libunwind_frame_cache);
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cache->func_addr = frame_func_unwind (next_frame);
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/* Get a libunwind cursor to the previous frame. We do this by initializing
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a cursor. Libunwind treats a new cursor as the top of stack and will get
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the current register set via the libunwind register accessor. Now, we
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provide the platform-specific accessors and we set up the register accessor to use
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the frame register unwinding interfaces so that we properly get the registers for
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the current frame rather than the top. We then use the unw_step function to
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move the libunwind cursor back one frame. We can later use this cursor to find previous
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registers via the unw_get_reg interface which will invoke libunwind's special logic. */
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descr = libunwind_descr (get_frame_arch (next_frame));
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acc = descr->accessors;
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as = unw_create_addr_space_p (acc,
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TARGET_BYTE_ORDER == BFD_ENDIAN_BIG
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? __BIG_ENDIAN
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: __LITTLE_ENDIAN);
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unw_init_remote_p (&cache->cursor, as, next_frame);
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unw_step_p (&cache->cursor);
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/* To get base address, get sp from previous frame. */
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uw_sp_regnum = descr->gdb2uw (SP_REGNUM);
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ret = unw_get_reg_p (&cache->cursor, uw_sp_regnum, &fp);
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if (ret < 0)
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error ("Can't get libunwind sp register.");
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cache->base = (CORE_ADDR)fp;
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*this_cache = cache;
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return cache;
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}
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unw_word_t
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libunwind_find_dyn_list (unw_addr_space_t as, unw_dyn_info_t *di, void *arg)
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{
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return unw_find_dyn_list_p (as, di, arg);
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}
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static const struct frame_unwind libunwind_frame_unwind =
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{
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NORMAL_FRAME,
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libunwind_frame_this_id,
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libunwind_frame_prev_register
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};
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/* Verify if there is sufficient libunwind information for the frame to use
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libunwind frame unwinding. */
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const struct frame_unwind *
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libunwind_frame_sniffer (struct frame_info *next_frame)
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{
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unw_cursor_t cursor;
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unw_accessors_t *acc;
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unw_addr_space_t as;
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struct libunwind_descr *descr;
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int i, ret;
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/* To test for libunwind unwind support, initialize a cursor to the current frame and try to back
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up. We use this same method when setting up the frame cache (see libunwind_frame_cache()).
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If libunwind returns success for this operation, it means that it has found sufficient
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libunwind unwinding information to do so. */
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descr = libunwind_descr (get_frame_arch (next_frame));
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acc = descr->accessors;
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as = unw_create_addr_space_p (acc,
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TARGET_BYTE_ORDER == BFD_ENDIAN_BIG
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? __BIG_ENDIAN
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: __LITTLE_ENDIAN);
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ret = unw_init_remote_p (&cursor, as, next_frame);
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if (ret >= 0)
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ret = unw_step_p (&cursor);
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if (ret < 0)
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return NULL;
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return &libunwind_frame_unwind;
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}
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void
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libunwind_frame_this_id (struct frame_info *next_frame, void **this_cache,
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struct frame_id *this_id)
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{
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struct libunwind_frame_cache *cache =
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libunwind_frame_cache (next_frame, this_cache);
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(*this_id) = frame_id_build (cache->base, cache->func_addr);
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}
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void
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libunwind_frame_prev_register (struct frame_info *next_frame, void **this_cache,
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int regnum, int *optimizedp,
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enum lval_type *lvalp, CORE_ADDR *addrp,
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int *realnump, void *valuep)
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{
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struct libunwind_frame_cache *cache =
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libunwind_frame_cache (next_frame, this_cache);
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void *ptr;
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unw_cursor_t *c;
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unw_save_loc_t sl;
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int i, ret;
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unw_word_t intval;
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unw_fpreg_t fpval;
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unw_regnum_t uw_regnum;
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struct libunwind_descr *descr;
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/* Convert from gdb register number to libunwind register number. */
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descr = libunwind_descr (get_frame_arch (next_frame));
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uw_regnum = descr->gdb2uw (regnum);
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gdb_assert (regnum >= 0);
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if (!target_has_registers)
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error ("No registers.");
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*optimizedp = 0;
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*addrp = 0;
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*lvalp = not_lval;
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*realnump = -1;
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if (valuep)
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memset (valuep, 0, register_size (current_gdbarch, regnum));
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if (uw_regnum < 0)
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return;
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/* To get the previous register, we use the libunwind register APIs with
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the cursor we have already pushed back to the previous frame. */
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if (descr->is_fpreg (uw_regnum))
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{
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ret = unw_get_fpreg_p (&cache->cursor, uw_regnum, &fpval);
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ptr = &fpval;
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}
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else
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{
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ret = unw_get_reg_p (&cache->cursor, uw_regnum, &intval);
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ptr = &intval;
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}
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if (ret < 0)
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return;
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if (valuep)
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memcpy (valuep, ptr, register_size (current_gdbarch, regnum));
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if (unw_get_saveloc_p (&cache->cursor, uw_regnum, &sl) < 0)
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return;
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switch (sl.type)
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{
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case UNW_SLT_NONE:
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*optimizedp = 1;
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break;
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case UNW_SLT_MEMORY:
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*lvalp = lval_memory;
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*addrp = sl.u.addr;
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break;
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case UNW_SLT_REG:
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*lvalp = lval_register;
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*realnump = regnum;
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break;
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}
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}
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CORE_ADDR
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libunwind_frame_base_address (struct frame_info *next_frame, void **this_cache)
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{
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struct libunwind_frame_cache *cache =
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libunwind_frame_cache (next_frame, this_cache);
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return cache->base;
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}
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/* The following is a glue routine to call the libunwind unwind table
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search function to get unwind information for a specified ip address. */
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int
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libunwind_search_unwind_table (void *as, long ip, void *di,
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void *pi, int need_unwind_info, void *args)
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{
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return unw_search_unwind_table_p (*(unw_addr_space_t *)as, (unw_word_t )ip,
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di, pi, need_unwind_info, args);
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}
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static int
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libunwind_load (void)
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{
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void *handle;
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handle = dlopen (LIBUNWIND_SO, RTLD_NOW);
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if (handle == NULL)
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return 0;
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/* Initialize pointers to the dynamic library functions we will use. */
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unw_get_reg_p = dlsym (handle, get_reg_name);
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if (unw_get_reg_p == NULL)
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return 0;
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unw_get_fpreg_p = dlsym (handle, get_fpreg_name);
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if (unw_get_fpreg_p == NULL)
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return 0;
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unw_get_saveloc_p = dlsym (handle, get_saveloc_name);
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if (unw_get_saveloc_p == NULL)
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return 0;
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unw_step_p = dlsym (handle, step_name);
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if (unw_step_p == NULL)
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return 0;
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unw_init_remote_p = dlsym (handle, init_remote_name);
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if (unw_init_remote_p == NULL)
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return 0;
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unw_create_addr_space_p = dlsym (handle, create_addr_space_name);
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if (unw_create_addr_space_p == NULL)
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return 0;
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unw_search_unwind_table_p = dlsym (handle, search_unwind_table_name);
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if (unw_search_unwind_table_p == NULL)
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return 0;
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unw_find_dyn_list_p = dlsym (handle, find_dyn_list_name);
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if (unw_find_dyn_list_p == NULL)
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return 0;
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return 1;
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}
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int
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libunwind_is_initialized (void)
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{
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return libunwind_initialized;
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}
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/* Provide a prototype to silence -Wmissing-prototypes. */
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void _initialize_libunwind_frame (void);
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void
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_initialize_libunwind_frame (void)
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{
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libunwind_descr_handle = gdbarch_data_register_post_init (libunwind_descr_init);
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libunwind_initialized = libunwind_load ();
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}
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