244 lines
7.2 KiB
C
244 lines
7.2 KiB
C
/* Traditional frame unwind support, for GDB the GNU Debugger.
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Copyright (C) 2003-2022 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 "trad-frame.h"
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#include "regcache.h"
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#include "frame-unwind.h"
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#include "target.h"
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#include "value.h"
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#include "gdbarch.h"
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#include "gdbsupport/traits.h"
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struct trad_frame_cache
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{
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struct frame_info *this_frame;
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CORE_ADDR this_base;
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trad_frame_saved_reg *prev_regs;
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struct frame_id this_id;
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};
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struct trad_frame_cache *
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trad_frame_cache_zalloc (struct frame_info *this_frame)
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{
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struct trad_frame_cache *this_trad_cache;
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this_trad_cache = FRAME_OBSTACK_ZALLOC (struct trad_frame_cache);
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this_trad_cache->prev_regs = trad_frame_alloc_saved_regs (this_frame);
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this_trad_cache->this_frame = this_frame;
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return this_trad_cache;
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}
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/* See trad-frame.h. */
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void
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trad_frame_reset_saved_regs (struct gdbarch *gdbarch,
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trad_frame_saved_reg *regs)
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{
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int numregs = gdbarch_num_cooked_regs (gdbarch);
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for (int regnum = 0; regnum < numregs; regnum++)
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regs[regnum].set_realreg (regnum);
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}
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trad_frame_saved_reg *
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trad_frame_alloc_saved_regs (struct gdbarch *gdbarch)
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{
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#ifdef HAVE_IS_TRIVIALLY_CONSTRUCTIBLE
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gdb_static_assert (std::is_trivially_constructible<trad_frame_saved_reg>::value);
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#endif
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int numregs = gdbarch_num_cooked_regs (gdbarch);
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trad_frame_saved_reg *this_saved_regs
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= FRAME_OBSTACK_CALLOC (numregs, trad_frame_saved_reg);
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/* For backwards compatibility, initialize all the register values to
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REALREG, with register 0 stored in 0, register 1 stored in 1 and so
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on. */
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trad_frame_reset_saved_regs (gdbarch, this_saved_regs);
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return this_saved_regs;
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}
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/* A traditional frame is unwound by analysing the function prologue
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and using the information gathered to track registers. For
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non-optimized frames, the technique is reliable (just need to check
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for all potential instruction sequences). */
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trad_frame_saved_reg *
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trad_frame_alloc_saved_regs (struct frame_info *this_frame)
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{
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struct gdbarch *gdbarch = get_frame_arch (this_frame);
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return trad_frame_alloc_saved_regs (gdbarch);
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}
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void
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trad_frame_set_reg_value (struct trad_frame_cache *this_trad_cache,
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int regnum, LONGEST val)
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{
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/* External interface for users of trad_frame_cache
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(who cannot access the prev_regs object directly). */
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this_trad_cache->prev_regs[regnum].set_value (val);
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}
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void
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trad_frame_set_reg_realreg (struct trad_frame_cache *this_trad_cache,
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int regnum, int realreg)
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{
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this_trad_cache->prev_regs[regnum].set_realreg (realreg);
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}
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void
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trad_frame_set_reg_addr (struct trad_frame_cache *this_trad_cache,
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int regnum, CORE_ADDR addr)
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{
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this_trad_cache->prev_regs[regnum].set_addr (addr);
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}
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void
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trad_frame_set_reg_regmap (struct trad_frame_cache *this_trad_cache,
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const struct regcache_map_entry *regmap,
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CORE_ADDR addr, size_t size)
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{
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struct gdbarch *gdbarch = get_frame_arch (this_trad_cache->this_frame);
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int offs = 0, count;
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for (; (count = regmap->count) != 0; regmap++)
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{
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int regno = regmap->regno;
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int slot_size = regmap->size;
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if (slot_size == 0 && regno != REGCACHE_MAP_SKIP)
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slot_size = register_size (gdbarch, regno);
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if (offs + slot_size > size)
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break;
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if (regno == REGCACHE_MAP_SKIP)
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offs += count * slot_size;
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else
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for (; count--; regno++, offs += slot_size)
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{
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/* Mimic the semantics of regcache::transfer_regset if a
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register slot's size does not match the size of a
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register.
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If a register slot is larger than a register, assume
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the register's value is stored in the first N bytes of
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the slot and ignore the remaining bytes.
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If the register slot is smaller than the register,
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assume that the slot contains the low N bytes of the
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register's value. Since trad_frame assumes that
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registers stored by address are sized according to the
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register, read the low N bytes and zero-extend them to
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generate a register value. */
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if (slot_size >= register_size (gdbarch, regno))
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trad_frame_set_reg_addr (this_trad_cache, regno, addr + offs);
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else
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{
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enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
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gdb_byte buf[slot_size];
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if (target_read_memory (addr + offs, buf, sizeof buf) == 0)
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{
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LONGEST val
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= extract_unsigned_integer (buf, sizeof buf, byte_order);
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trad_frame_set_reg_value (this_trad_cache, regno, val);
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}
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}
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}
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}
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}
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/* See trad-frame.h. */
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void
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trad_frame_set_reg_value_bytes (struct trad_frame_cache *this_trad_cache,
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int regnum,
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gdb::array_view<const gdb_byte> bytes)
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{
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/* External interface for users of trad_frame_cache
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(who cannot access the prev_regs object directly). */
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this_trad_cache->prev_regs[regnum].set_value_bytes (bytes);
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}
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struct value *
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trad_frame_get_prev_register (struct frame_info *this_frame,
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trad_frame_saved_reg this_saved_regs[],
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int regnum)
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{
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if (this_saved_regs[regnum].is_addr ())
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/* The register was saved in memory. */
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return frame_unwind_got_memory (this_frame, regnum,
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this_saved_regs[regnum].addr ());
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else if (this_saved_regs[regnum].is_realreg ())
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return frame_unwind_got_register (this_frame, regnum,
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this_saved_regs[regnum].realreg ());
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else if (this_saved_regs[regnum].is_value ())
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/* The register's value is available. */
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return frame_unwind_got_constant (this_frame, regnum,
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this_saved_regs[regnum].value ());
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else if (this_saved_regs[regnum].is_value_bytes ())
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/* The register's value is available as a sequence of bytes. */
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return frame_unwind_got_bytes (this_frame, regnum,
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this_saved_regs[regnum].value_bytes ());
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else
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return frame_unwind_got_optimized (this_frame, regnum);
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}
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struct value *
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trad_frame_get_register (struct trad_frame_cache *this_trad_cache,
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struct frame_info *this_frame,
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int regnum)
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{
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return trad_frame_get_prev_register (this_frame, this_trad_cache->prev_regs,
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regnum);
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}
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void
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trad_frame_set_id (struct trad_frame_cache *this_trad_cache,
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struct frame_id this_id)
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{
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this_trad_cache->this_id = this_id;
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}
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void
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trad_frame_get_id (struct trad_frame_cache *this_trad_cache,
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struct frame_id *this_id)
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{
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(*this_id) = this_trad_cache->this_id;
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}
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void
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trad_frame_set_this_base (struct trad_frame_cache *this_trad_cache,
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CORE_ADDR this_base)
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{
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this_trad_cache->this_base = this_base;
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}
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CORE_ADDR
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trad_frame_get_this_base (struct trad_frame_cache *this_trad_cache)
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{
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return this_trad_cache->this_base;
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}
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