/* Traditional frame unwind support, for GDB the GNU Debugger.
- Copyright (C) 2003, 2004, 2007 Free Software Foundation, Inc.
+ Copyright (C) 2003-2022 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 51 Franklin Street, Fifth Floor,
- Boston, MA 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "frame.h"
#include "trad-frame.h"
#include "regcache.h"
+#include "frame-unwind.h"
+#include "target.h"
+#include "value.h"
+#include "gdbarch.h"
+#include "gdbsupport/traits.h"
struct trad_frame_cache
{
- struct frame_info *next_frame;
+ struct frame_info *this_frame;
CORE_ADDR this_base;
- struct trad_frame_saved_reg *prev_regs;
+ trad_frame_saved_reg *prev_regs;
struct frame_id this_id;
};
struct trad_frame_cache *
-trad_frame_cache_zalloc (struct frame_info *next_frame)
+trad_frame_cache_zalloc (struct frame_info *this_frame)
{
struct trad_frame_cache *this_trad_cache;
this_trad_cache = FRAME_OBSTACK_ZALLOC (struct trad_frame_cache);
- this_trad_cache->prev_regs = trad_frame_alloc_saved_regs (next_frame);
- this_trad_cache->next_frame = next_frame;
+ this_trad_cache->prev_regs = trad_frame_alloc_saved_regs (this_frame);
+ this_trad_cache->this_frame = this_frame;
return this_trad_cache;
}
-/* A traditional frame is unwound by analysing the function prologue
- and using the information gathered to track registers. For
- non-optimized frames, the technique is reliable (just need to check
- for all potential instruction sequences). */
+/* See trad-frame.h. */
-struct trad_frame_saved_reg *
-trad_frame_alloc_saved_regs (struct frame_info *next_frame)
+void
+trad_frame_reset_saved_regs (struct gdbarch *gdbarch,
+ trad_frame_saved_reg *regs)
{
- int regnum;
- struct gdbarch *gdbarch = get_frame_arch (next_frame);
- int numregs = NUM_REGS + NUM_PSEUDO_REGS;
- struct trad_frame_saved_reg *this_saved_regs
- = FRAME_OBSTACK_CALLOC (numregs, struct trad_frame_saved_reg);
- for (regnum = 0; regnum < numregs; regnum++)
- {
- this_saved_regs[regnum].realreg = regnum;
- this_saved_regs[regnum].addr = -1;
- }
- return this_saved_regs;
-}
+ int numregs = gdbarch_num_cooked_regs (gdbarch);
-enum { REG_VALUE = -1, REG_UNKNOWN = -2 };
-
-int
-trad_frame_value_p (struct trad_frame_saved_reg this_saved_regs[], int regnum)
-{
- return (this_saved_regs[regnum].realreg == REG_VALUE);
+ for (int regnum = 0; regnum < numregs; regnum++)
+ regs[regnum].set_realreg (regnum);
}
-int
-trad_frame_addr_p (struct trad_frame_saved_reg this_saved_regs[], int regnum)
+trad_frame_saved_reg *
+trad_frame_alloc_saved_regs (struct gdbarch *gdbarch)
{
- return (this_saved_regs[regnum].realreg >= 0
- && this_saved_regs[regnum].addr != -1);
-}
+#ifdef HAVE_IS_TRIVIALLY_CONSTRUCTIBLE
+ gdb_static_assert (std::is_trivially_constructible<trad_frame_saved_reg>::value);
+#endif
-int
-trad_frame_realreg_p (struct trad_frame_saved_reg this_saved_regs[],
- int regnum)
-{
- return (this_saved_regs[regnum].realreg >= 0
- && this_saved_regs[regnum].addr == -1);
+ int numregs = gdbarch_num_cooked_regs (gdbarch);
+ trad_frame_saved_reg *this_saved_regs
+ = FRAME_OBSTACK_CALLOC (numregs, trad_frame_saved_reg);
+
+ /* For backwards compatibility, initialize all the register values to
+ REALREG, with register 0 stored in 0, register 1 stored in 1 and so
+ on. */
+ trad_frame_reset_saved_regs (gdbarch, this_saved_regs);
+
+ return this_saved_regs;
}
-void
-trad_frame_set_value (struct trad_frame_saved_reg this_saved_regs[],
- int regnum, LONGEST val)
+/* A traditional frame is unwound by analysing the function prologue
+ and using the information gathered to track registers. For
+ non-optimized frames, the technique is reliable (just need to check
+ for all potential instruction sequences). */
+
+trad_frame_saved_reg *
+trad_frame_alloc_saved_regs (struct frame_info *this_frame)
{
- /* Make the REALREG invalid, indicating that the ADDR contains the
- register's value. */
- this_saved_regs[regnum].realreg = REG_VALUE;
- this_saved_regs[regnum].addr = val;
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
+
+ return trad_frame_alloc_saved_regs (gdbarch);
}
void
{
/* External interface for users of trad_frame_cache
(who cannot access the prev_regs object directly). */
- trad_frame_set_value (this_trad_cache->prev_regs, regnum, val);
+ this_trad_cache->prev_regs[regnum].set_value (val);
}
void
trad_frame_set_reg_realreg (struct trad_frame_cache *this_trad_cache,
int regnum, int realreg)
{
- this_trad_cache->prev_regs[regnum].realreg = realreg;
- this_trad_cache->prev_regs[regnum].addr = -1;
+ this_trad_cache->prev_regs[regnum].set_realreg (realreg);
}
void
trad_frame_set_reg_addr (struct trad_frame_cache *this_trad_cache,
int regnum, CORE_ADDR addr)
{
- this_trad_cache->prev_regs[regnum].addr = addr;
+ this_trad_cache->prev_regs[regnum].set_addr (addr);
}
void
-trad_frame_set_unknown (struct trad_frame_saved_reg this_saved_regs[],
- int regnum)
+trad_frame_set_reg_regmap (struct trad_frame_cache *this_trad_cache,
+ const struct regcache_map_entry *regmap,
+ CORE_ADDR addr, size_t size)
{
- /* Make the REALREG invalid, indicating that the value is not known. */
- this_saved_regs[regnum].realreg = REG_UNKNOWN;
- this_saved_regs[regnum].addr = -1;
-}
+ struct gdbarch *gdbarch = get_frame_arch (this_trad_cache->this_frame);
+ int offs = 0, count;
-void
-trad_frame_get_prev_register (struct frame_info *next_frame,
- struct trad_frame_saved_reg this_saved_regs[],
- int regnum, int *optimizedp,
- enum lval_type *lvalp, CORE_ADDR *addrp,
- int *realregp, gdb_byte *bufferp)
-{
- struct gdbarch *gdbarch = get_frame_arch (next_frame);
- if (trad_frame_addr_p (this_saved_regs, regnum))
- {
- /* The register was saved in memory. */
- *optimizedp = 0;
- *lvalp = lval_memory;
- *addrp = this_saved_regs[regnum].addr;
- *realregp = -1;
- if (bufferp != NULL)
- {
- /* Read the value in from memory. */
- get_frame_memory (next_frame, this_saved_regs[regnum].addr, bufferp,
- register_size (gdbarch, regnum));
- }
- }
- else if (trad_frame_realreg_p (this_saved_regs, regnum))
- {
- *optimizedp = 0;
- *lvalp = lval_register;
- *addrp = 0;
- *realregp = this_saved_regs[regnum].realreg;
- /* Ask the next frame to return the value of the register. */
- if (bufferp)
- frame_unwind_register (next_frame, (*realregp), bufferp);
- }
- else if (trad_frame_value_p (this_saved_regs, regnum))
+ for (; (count = regmap->count) != 0; regmap++)
{
- /* The register's value is available. */
- *optimizedp = 0;
- *lvalp = not_lval;
- *addrp = 0;
- *realregp = -1;
- if (bufferp != NULL)
- store_unsigned_integer (bufferp, register_size (gdbarch, regnum),
- this_saved_regs[regnum].addr);
- }
- else
- {
- error (_("Register %s not available"),
- gdbarch_register_name (gdbarch, regnum));
+ int regno = regmap->regno;
+ int slot_size = regmap->size;
+
+ if (slot_size == 0 && regno != REGCACHE_MAP_SKIP)
+ slot_size = register_size (gdbarch, regno);
+
+ if (offs + slot_size > size)
+ break;
+
+ if (regno == REGCACHE_MAP_SKIP)
+ offs += count * slot_size;
+ else
+ for (; count--; regno++, offs += slot_size)
+ {
+ /* Mimic the semantics of regcache::transfer_regset if a
+ register slot's size does not match the size of a
+ register.
+
+ If a register slot is larger than a register, assume
+ the register's value is stored in the first N bytes of
+ the slot and ignore the remaining bytes.
+
+ If the register slot is smaller than the register,
+ assume that the slot contains the low N bytes of the
+ register's value. Since trad_frame assumes that
+ registers stored by address are sized according to the
+ register, read the low N bytes and zero-extend them to
+ generate a register value. */
+ if (slot_size >= register_size (gdbarch, regno))
+ trad_frame_set_reg_addr (this_trad_cache, regno, addr + offs);
+ else
+ {
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ gdb_byte buf[slot_size];
+
+ if (target_read_memory (addr + offs, buf, sizeof buf) == 0)
+ {
+ LONGEST val
+ = extract_unsigned_integer (buf, sizeof buf, byte_order);
+ trad_frame_set_reg_value (this_trad_cache, regno, val);
+ }
+ }
+ }
}
}
+/* See trad-frame.h. */
+
void
+trad_frame_set_reg_value_bytes (struct trad_frame_cache *this_trad_cache,
+ int regnum,
+ gdb::array_view<const gdb_byte> bytes)
+{
+ /* External interface for users of trad_frame_cache
+ (who cannot access the prev_regs object directly). */
+ this_trad_cache->prev_regs[regnum].set_value_bytes (bytes);
+}
+
+
+
+struct value *
+trad_frame_get_prev_register (struct frame_info *this_frame,
+ trad_frame_saved_reg this_saved_regs[],
+ int regnum)
+{
+ if (this_saved_regs[regnum].is_addr ())
+ /* The register was saved in memory. */
+ return frame_unwind_got_memory (this_frame, regnum,
+ this_saved_regs[regnum].addr ());
+ else if (this_saved_regs[regnum].is_realreg ())
+ return frame_unwind_got_register (this_frame, regnum,
+ this_saved_regs[regnum].realreg ());
+ else if (this_saved_regs[regnum].is_value ())
+ /* The register's value is available. */
+ return frame_unwind_got_constant (this_frame, regnum,
+ this_saved_regs[regnum].value ());
+ else if (this_saved_regs[regnum].is_value_bytes ())
+ /* The register's value is available as a sequence of bytes. */
+ return frame_unwind_got_bytes (this_frame, regnum,
+ this_saved_regs[regnum].value_bytes ());
+ else
+ return frame_unwind_got_optimized (this_frame, regnum);
+}
+
+struct value *
trad_frame_get_register (struct trad_frame_cache *this_trad_cache,
- struct frame_info *next_frame,
- int regnum, int *optimizedp,
- enum lval_type *lvalp, CORE_ADDR *addrp,
- int *realregp, gdb_byte *bufferp)
-{
- trad_frame_get_prev_register (next_frame, this_trad_cache->prev_regs,
- regnum, optimizedp, lvalp, addrp, realregp,
- bufferp);
+ struct frame_info *this_frame,
+ int regnum)
+{
+ return trad_frame_get_prev_register (this_frame, this_trad_cache->prev_regs,
+ regnum);
}
void