287 lines
8.7 KiB
C
287 lines
8.7 KiB
C
/* Definitions for frame unwinder, for GDB, the GNU debugger.
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Copyright (C) 2003-2015 Free Software Foundation, 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 3 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, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "frame.h"
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#include "frame-unwind.h"
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#include "dummy-frame.h"
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#include "inline-frame.h"
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#include "value.h"
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#include "regcache.h"
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#include "gdb_obstack.h"
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#include "target.h"
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static struct gdbarch_data *frame_unwind_data;
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struct frame_unwind_table_entry
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{
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const struct frame_unwind *unwinder;
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struct frame_unwind_table_entry *next;
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};
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struct frame_unwind_table
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{
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struct frame_unwind_table_entry *list;
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/* The head of the OSABI part of the search list. */
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struct frame_unwind_table_entry **osabi_head;
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};
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static void *
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frame_unwind_init (struct obstack *obstack)
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{
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struct frame_unwind_table *table
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= OBSTACK_ZALLOC (obstack, struct frame_unwind_table);
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/* Start the table out with a few default sniffers. OSABI code
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can't override this. */
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table->list = OBSTACK_ZALLOC (obstack, struct frame_unwind_table_entry);
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table->list->unwinder = &dummy_frame_unwind;
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table->list->next = OBSTACK_ZALLOC (obstack,
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struct frame_unwind_table_entry);
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table->list->next->unwinder = &inline_frame_unwind;
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/* The insertion point for OSABI sniffers. */
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table->osabi_head = &table->list->next->next;
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return table;
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}
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void
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frame_unwind_prepend_unwinder (struct gdbarch *gdbarch,
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const struct frame_unwind *unwinder)
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{
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struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
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struct frame_unwind_table_entry *entry;
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/* Insert the new entry at the start of the list. */
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entry = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind_table_entry);
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entry->unwinder = unwinder;
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entry->next = (*table->osabi_head);
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(*table->osabi_head) = entry;
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}
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void
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frame_unwind_append_unwinder (struct gdbarch *gdbarch,
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const struct frame_unwind *unwinder)
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{
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struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
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struct frame_unwind_table_entry **ip;
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/* Find the end of the list and insert the new entry there. */
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for (ip = table->osabi_head; (*ip) != NULL; ip = &(*ip)->next);
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(*ip) = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind_table_entry);
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(*ip)->unwinder = unwinder;
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}
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/* Call SNIFFER from UNWINDER. If it succeeded set UNWINDER for
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THIS_FRAME and return 1. Otherwise the function keeps THIS_FRAME
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unchanged and returns 0. */
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static int
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frame_unwind_try_unwinder (struct frame_info *this_frame, void **this_cache,
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const struct frame_unwind *unwinder)
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{
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struct cleanup *old_cleanup;
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volatile struct gdb_exception ex;
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int res = 0;
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old_cleanup = frame_prepare_for_sniffer (this_frame, unwinder);
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TRY_CATCH (ex, RETURN_MASK_ERROR)
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{
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res = unwinder->sniffer (unwinder, this_frame, this_cache);
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}
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if (ex.reason < 0 && ex.error == NOT_AVAILABLE_ERROR)
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{
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/* This usually means that not even the PC is available,
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thus most unwinders aren't able to determine if they're
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the best fit. Keep trying. Fallback prologue unwinders
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should always accept the frame. */
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do_cleanups (old_cleanup);
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return 0;
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}
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else if (ex.reason < 0)
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throw_exception (ex);
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else if (res)
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{
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discard_cleanups (old_cleanup);
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return 1;
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}
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else
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{
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do_cleanups (old_cleanup);
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return 0;
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}
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gdb_assert_not_reached ("frame_unwind_try_unwinder");
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}
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/* Iterate through sniffers for THIS_FRAME frame until one returns with an
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unwinder implementation. THIS_FRAME->UNWIND must be NULL, it will get set
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by this function. Possibly initialize THIS_CACHE. */
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void
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frame_unwind_find_by_frame (struct frame_info *this_frame, void **this_cache)
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{
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struct gdbarch *gdbarch = get_frame_arch (this_frame);
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struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
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struct frame_unwind_table_entry *entry;
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const struct frame_unwind *unwinder_from_target;
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unwinder_from_target = target_get_unwinder ();
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if (unwinder_from_target != NULL
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&& frame_unwind_try_unwinder (this_frame, this_cache,
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unwinder_from_target))
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return;
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unwinder_from_target = target_get_tailcall_unwinder ();
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if (unwinder_from_target != NULL
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&& frame_unwind_try_unwinder (this_frame, this_cache,
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unwinder_from_target))
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return;
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for (entry = table->list; entry != NULL; entry = entry->next)
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if (frame_unwind_try_unwinder (this_frame, this_cache, entry->unwinder))
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return;
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internal_error (__FILE__, __LINE__, _("frame_unwind_find_by_frame failed"));
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}
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/* A default frame sniffer which always accepts the frame. Used by
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fallback prologue unwinders. */
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int
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default_frame_sniffer (const struct frame_unwind *self,
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struct frame_info *this_frame,
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void **this_prologue_cache)
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{
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return 1;
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}
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/* The default frame unwinder stop_reason callback. */
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enum unwind_stop_reason
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default_frame_unwind_stop_reason (struct frame_info *this_frame,
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void **this_cache)
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{
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struct frame_id this_id = get_frame_id (this_frame);
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if (frame_id_eq (this_id, outer_frame_id))
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return UNWIND_OUTERMOST;
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else
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return UNWIND_NO_REASON;
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}
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/* Helper functions for value-based register unwinding. These return
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a (possibly lazy) value of the appropriate type. */
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/* Return a value which indicates that FRAME did not save REGNUM. */
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struct value *
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frame_unwind_got_optimized (struct frame_info *frame, int regnum)
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{
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struct gdbarch *gdbarch = frame_unwind_arch (frame);
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struct type *type = register_type (gdbarch, regnum);
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struct value *val;
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/* Return an lval_register value, so that we print it as
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"<not saved>". */
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val = allocate_value_lazy (type);
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set_value_lazy (val, 0);
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mark_value_bytes_optimized_out (val, 0, TYPE_LENGTH (type));
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VALUE_LVAL (val) = lval_register;
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VALUE_REGNUM (val) = regnum;
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VALUE_FRAME_ID (val) = get_frame_id (frame);
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return val;
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}
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/* Return a value which indicates that FRAME copied REGNUM into
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register NEW_REGNUM. */
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struct value *
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frame_unwind_got_register (struct frame_info *frame,
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int regnum, int new_regnum)
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{
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return value_of_register_lazy (frame, new_regnum);
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}
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/* Return a value which indicates that FRAME saved REGNUM in memory at
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ADDR. */
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struct value *
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frame_unwind_got_memory (struct frame_info *frame, int regnum, CORE_ADDR addr)
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{
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struct gdbarch *gdbarch = frame_unwind_arch (frame);
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struct value *v = value_at_lazy (register_type (gdbarch, regnum), addr);
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set_value_stack (v, 1);
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return v;
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}
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/* Return a value which indicates that FRAME's saved version of
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REGNUM has a known constant (computed) value of VAL. */
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struct value *
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frame_unwind_got_constant (struct frame_info *frame, int regnum,
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ULONGEST val)
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{
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struct gdbarch *gdbarch = frame_unwind_arch (frame);
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enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
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struct value *reg_val;
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reg_val = value_zero (register_type (gdbarch, regnum), not_lval);
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store_unsigned_integer (value_contents_writeable (reg_val),
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register_size (gdbarch, regnum), byte_order, val);
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return reg_val;
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}
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struct value *
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frame_unwind_got_bytes (struct frame_info *frame, int regnum, gdb_byte *buf)
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{
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struct gdbarch *gdbarch = frame_unwind_arch (frame);
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struct value *reg_val;
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reg_val = value_zero (register_type (gdbarch, regnum), not_lval);
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memcpy (value_contents_raw (reg_val), buf, register_size (gdbarch, regnum));
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return reg_val;
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}
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/* Return a value which indicates that FRAME's saved version of REGNUM
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has a known constant (computed) value of ADDR. Convert the
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CORE_ADDR to a target address if necessary. */
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struct value *
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frame_unwind_got_address (struct frame_info *frame, int regnum,
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CORE_ADDR addr)
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{
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struct gdbarch *gdbarch = frame_unwind_arch (frame);
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struct value *reg_val;
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reg_val = value_zero (register_type (gdbarch, regnum), not_lval);
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pack_long (value_contents_writeable (reg_val),
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register_type (gdbarch, regnum), addr);
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return reg_val;
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}
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/* -Wmissing-prototypes */
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extern initialize_file_ftype _initialize_frame_unwind;
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void
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_initialize_frame_unwind (void)
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{
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frame_unwind_data = gdbarch_data_register_pre_init (frame_unwind_init);
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}
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