3f244638cf
(m68k_gdbarch_init): Add the DWARF CFI frame unwinder. * Makefile.in (m68k-tdep.o): Update dependencies.
1195 lines
32 KiB
C
1195 lines
32 KiB
C
/* Target dependent code for the Motorola 68000 series.
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Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1999, 2000, 2001,
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2002, 2003
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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 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 "dwarf2-frame.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 "symtab.h"
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#include "gdbcore.h"
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#include "value.h"
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#include "gdb_string.h"
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#include "gdb_assert.h"
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#include "inferior.h"
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#include "regcache.h"
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#include "arch-utils.h"
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#include "osabi.h"
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#include "dis-asm.h"
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#include "m68k-tdep.h"
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#define P_LINKL_FP 0x480e
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#define P_LINKW_FP 0x4e56
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#define P_PEA_FP 0x4856
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#define P_MOVEAL_SP_FP 0x2c4f
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#define P_ADDAW_SP 0xdefc
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#define P_ADDAL_SP 0xdffc
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#define P_SUBQW_SP 0x514f
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#define P_SUBQL_SP 0x518f
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#define P_LEA_SP_SP 0x4fef
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#define P_LEA_PC_A5 0x4bfb0170
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#define P_FMOVEMX_SP 0xf227
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#define P_MOVEL_SP 0x2f00
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#define P_MOVEML_SP 0x48e7
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#define REGISTER_BYTES_FP (16*4 + 8 + 8*12 + 3*4)
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#define REGISTER_BYTES_NOFP (16*4 + 8)
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/* Offset from SP to first arg on stack at first instruction of a function */
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#define SP_ARG0 (1 * 4)
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#if !defined (BPT_VECTOR)
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#define BPT_VECTOR 0xf
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#endif
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#if !defined (REMOTE_BPT_VECTOR)
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#define REMOTE_BPT_VECTOR 1
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#endif
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/* gdbarch_breakpoint_from_pc is set to m68k_local_breakpoint_from_pc
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so m68k_remote_breakpoint_from_pc is currently not used. */
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static const unsigned char *
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m68k_remote_breakpoint_from_pc (CORE_ADDR *pcptr, int *lenptr)
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{
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static unsigned char break_insn[] = {0x4e, (0x40 | REMOTE_BPT_VECTOR)};
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*lenptr = sizeof (break_insn);
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return break_insn;
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}
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static const unsigned char *
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m68k_local_breakpoint_from_pc (CORE_ADDR *pcptr, int *lenptr)
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{
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static unsigned char break_insn[] = {0x4e, (0x40 | BPT_VECTOR)};
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*lenptr = sizeof (break_insn);
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return break_insn;
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}
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static int
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m68k_register_bytes_ok (long numbytes)
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{
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return ((numbytes == REGISTER_BYTES_FP)
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|| (numbytes == REGISTER_BYTES_NOFP));
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}
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/* Return the GDB type object for the "standard" data type of data in
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register N. This should be int for D0-D7, SR, FPCONTROL and
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FPSTATUS, long double for FP0-FP7, and void pointer for all others
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(A0-A7, PC, FPIADDR). Note, for registers which contain
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addresses return pointer to void, not pointer to char, because we
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don't want to attempt to print the string after printing the
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address. */
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static struct type *
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m68k_register_type (struct gdbarch *gdbarch, int regnum)
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{
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if (regnum >= FP0_REGNUM && regnum <= FP0_REGNUM + 7)
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return builtin_type_m68881_ext;
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if (regnum == M68K_FPI_REGNUM || regnum == PC_REGNUM)
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return builtin_type_void_func_ptr;
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if (regnum == M68K_FPC_REGNUM || regnum == M68K_FPS_REGNUM
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|| regnum == PS_REGNUM)
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return builtin_type_int32;
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if (regnum >= M68K_A0_REGNUM && regnum <= M68K_A0_REGNUM + 7)
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return builtin_type_void_data_ptr;
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return builtin_type_int32;
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}
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/* Function: m68k_register_name
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Returns the name of the standard m68k register regnum. */
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static const char *
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m68k_register_name (int regnum)
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{
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static char *register_names[] = {
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"d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7",
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"a0", "a1", "a2", "a3", "a4", "a5", "fp", "sp",
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"ps", "pc",
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"fp0", "fp1", "fp2", "fp3", "fp4", "fp5", "fp6", "fp7",
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"fpcontrol", "fpstatus", "fpiaddr", "fpcode", "fpflags"
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};
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if (regnum < 0 ||
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regnum >= sizeof (register_names) / sizeof (register_names[0]))
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internal_error (__FILE__, __LINE__,
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"m68k_register_name: illegal register number %d", regnum);
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else
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return register_names[regnum];
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}
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/* Index within `registers' of the first byte of the space for
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register regnum. */
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static int
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m68k_register_byte (int regnum)
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{
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if (regnum >= M68K_FPC_REGNUM)
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return (((regnum - M68K_FPC_REGNUM) * 4) + 168);
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else if (regnum >= FP0_REGNUM)
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return (((regnum - FP0_REGNUM) * 12) + 72);
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else
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return (regnum * 4);
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}
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/* Extract from an array REGBUF containing the (raw) register state, a
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function return value of TYPE, and copy that, in virtual format,
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into VALBUF. */
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static void
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m68k_extract_return_value (struct type *type, struct regcache *regcache,
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void *valbuf)
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{
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int len = TYPE_LENGTH (type);
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char buf[M68K_MAX_REGISTER_SIZE];
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if (TYPE_CODE (type) == TYPE_CODE_STRUCT
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&& TYPE_NFIELDS (type) == 1)
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{
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m68k_extract_return_value (TYPE_FIELD_TYPE (type, 0), regcache, valbuf);
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return;
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}
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if (len <= 4)
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{
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regcache_raw_read (regcache, M68K_D0_REGNUM, buf);
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memcpy (valbuf, buf + (4 - len), len);
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}
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else if (len <= 8)
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{
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regcache_raw_read (regcache, M68K_D0_REGNUM, buf);
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memcpy (valbuf, buf + (8 - len), len - 4);
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regcache_raw_read (regcache, M68K_D1_REGNUM,
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(char *) valbuf + (len - 4));
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}
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else
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internal_error (__FILE__, __LINE__,
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"Cannot extract return value of %d bytes long.", len);
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}
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/* Write into the appropriate registers a function return value stored
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in VALBUF of type TYPE, given in virtual format. */
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static void
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m68k_store_return_value (struct type *type, struct regcache *regcache,
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const void *valbuf)
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{
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int len = TYPE_LENGTH (type);
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if (TYPE_CODE (type) == TYPE_CODE_STRUCT
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&& TYPE_NFIELDS (type) == 1)
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{
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m68k_store_return_value (TYPE_FIELD_TYPE (type, 0), regcache, valbuf);
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return;
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}
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if (len <= 4)
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regcache_raw_write_part (regcache, M68K_D0_REGNUM, 4 - len, len, valbuf);
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else if (len <= 8)
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{
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regcache_raw_write_part (regcache, M68K_D1_REGNUM, 8 - len,
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len - 4, valbuf);
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regcache_raw_write (regcache, M68K_D0_REGNUM,
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(char *) valbuf + (len - 4));
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}
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else
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internal_error (__FILE__, __LINE__,
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"Cannot store return value of %d bytes long.", len);
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}
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/* Extract from REGCACHE, which contains the (raw) register state, the
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address in which a function should return its structure value, as a
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CORE_ADDR. */
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static CORE_ADDR
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m68k_extract_struct_value_address (struct regcache *regcache)
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{
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char buf[4];
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regcache_cooked_read (regcache, M68K_D0_REGNUM, buf);
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return extract_unsigned_integer (buf, 4);
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}
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static int
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m68k_use_struct_convention (int gcc_p, struct type *type)
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{
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enum struct_return struct_return;
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struct_return = gdbarch_tdep (current_gdbarch)->struct_return;
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return generic_use_struct_convention (struct_return == reg_struct_return,
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type);
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}
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/* A function that tells us whether the function invocation represented
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by fi does not have a frame on the stack associated with it. If it
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does not, FRAMELESS is set to 1, else 0. */
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static int
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m68k_frameless_function_invocation (struct frame_info *fi)
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{
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if (get_frame_type (fi) == SIGTRAMP_FRAME)
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return 0;
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else
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return frameless_look_for_prologue (fi);
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}
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int
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delta68_in_sigtramp (CORE_ADDR pc, char *name)
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{
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if (name != NULL)
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return strcmp (name, "_sigcode") == 0;
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else
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return 0;
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}
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CORE_ADDR
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delta68_frame_args_address (struct frame_info *frame_info)
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{
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/* we assume here that the only frameless functions are the system calls
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or other functions who do not put anything on the stack. */
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if (get_frame_type (frame_info) == SIGTRAMP_FRAME)
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return get_frame_base (frame_info) + 12;
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else if (frameless_look_for_prologue (frame_info))
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{
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/* Check for an interrupted system call */
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if (get_next_frame (frame_info) && (get_frame_type (get_next_frame (frame_info)) == SIGTRAMP_FRAME))
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return get_frame_base (get_next_frame (frame_info)) + 16;
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else
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return get_frame_base (frame_info) + 4;
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}
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else
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return get_frame_base (frame_info);
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}
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CORE_ADDR
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delta68_frame_saved_pc (struct frame_info *frame_info)
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{
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return read_memory_unsigned_integer (delta68_frame_args_address (frame_info)
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+ 4, 4);
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}
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int
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delta68_frame_num_args (struct frame_info *fi)
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{
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int val;
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CORE_ADDR pc = DEPRECATED_FRAME_SAVED_PC (fi);
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int insn = read_memory_unsigned_integer (pc, 2);
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val = 0;
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if (insn == 0047757 || insn == 0157374) /* lea W(sp),sp or addaw #W,sp */
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val = read_memory_integer (pc + 2, 2);
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else if ((insn & 0170777) == 0050217 /* addql #N, sp */
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|| (insn & 0170777) == 0050117) /* addqw */
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{
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val = (insn >> 9) & 7;
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if (val == 0)
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val = 8;
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}
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else if (insn == 0157774) /* addal #WW, sp */
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val = read_memory_integer (pc + 2, 4);
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val >>= 2;
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return val;
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}
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static CORE_ADDR
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m68k_push_dummy_call (struct gdbarch *gdbarch, CORE_ADDR func_addr,
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struct regcache *regcache, CORE_ADDR bp_addr, int nargs,
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struct value **args, CORE_ADDR sp, int struct_return,
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CORE_ADDR struct_addr)
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{
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char buf[4];
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int i;
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/* Push arguments in reverse order. */
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for (i = nargs - 1; i >= 0; i--)
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{
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struct type *value_type = VALUE_ENCLOSING_TYPE (args[i]);
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int len = TYPE_LENGTH (value_type);
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int container_len = (len + 3) & ~3;
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int offset;
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/* Non-scalars bigger than 4 bytes are left aligned, others are
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right aligned. */
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if ((TYPE_CODE (value_type) == TYPE_CODE_STRUCT
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|| TYPE_CODE (value_type) == TYPE_CODE_UNION
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|| TYPE_CODE (value_type) == TYPE_CODE_ARRAY)
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&& len > 4)
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offset = 0;
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else
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offset = container_len - len;
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sp -= container_len;
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write_memory (sp + offset, VALUE_CONTENTS_ALL (args[i]), len);
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}
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/* Store struct value address. */
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if (struct_return)
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{
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store_unsigned_integer (buf, 4, struct_addr);
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regcache_cooked_write (regcache, M68K_A1_REGNUM, buf);
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}
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/* Store return address. */
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sp -= 4;
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store_unsigned_integer (buf, 4, bp_addr);
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write_memory (sp, buf, 4);
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/* Finally, update the stack pointer... */
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store_unsigned_integer (buf, 4, sp);
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regcache_cooked_write (regcache, M68K_SP_REGNUM, buf);
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/* ...and fake a frame pointer. */
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regcache_cooked_write (regcache, M68K_FP_REGNUM, buf);
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/* DWARF2/GCC uses the stack address *before* the function call as a
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frame's CFA. */
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return sp + 8;
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}
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struct m68k_frame_cache
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{
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/* Base address. */
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CORE_ADDR base;
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CORE_ADDR sp_offset;
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CORE_ADDR pc;
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/* Saved registers. */
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CORE_ADDR saved_regs[M68K_NUM_REGS];
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CORE_ADDR saved_sp;
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/* Stack space reserved for local variables. */
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long locals;
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};
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/* Allocate and initialize a frame cache. */
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static struct m68k_frame_cache *
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m68k_alloc_frame_cache (void)
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{
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struct m68k_frame_cache *cache;
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int i;
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cache = FRAME_OBSTACK_ZALLOC (struct m68k_frame_cache);
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/* Base address. */
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cache->base = 0;
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cache->sp_offset = -4;
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cache->pc = 0;
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/* Saved registers. We initialize these to -1 since zero is a valid
|
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offset (that's where %fp is supposed to be stored). */
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for (i = 0; i < M68K_NUM_REGS; i++)
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cache->saved_regs[i] = -1;
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|
||
/* Frameless until proven otherwise. */
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cache->locals = -1;
|
||
|
||
return cache;
|
||
}
|
||
|
||
/* Check whether PC points at a code that sets up a new stack frame.
|
||
If so, it updates CACHE and returns the address of the first
|
||
instruction after the sequence that sets removes the "hidden"
|
||
argument from the stack or CURRENT_PC, whichever is smaller.
|
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Otherwise, return PC. */
|
||
|
||
static CORE_ADDR
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||
m68k_analyze_frame_setup (CORE_ADDR pc, CORE_ADDR current_pc,
|
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struct m68k_frame_cache *cache)
|
||
{
|
||
int op;
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||
|
||
if (pc >= current_pc)
|
||
return current_pc;
|
||
|
||
op = read_memory_unsigned_integer (pc, 2);
|
||
|
||
if (op == P_LINKW_FP || op == P_LINKL_FP || op == P_PEA_FP)
|
||
{
|
||
cache->saved_regs[M68K_FP_REGNUM] = 0;
|
||
cache->sp_offset += 4;
|
||
if (op == P_LINKW_FP)
|
||
{
|
||
/* link.w %fp, #-N */
|
||
/* link.w %fp, #0; adda.l #-N, %sp */
|
||
cache->locals = -read_memory_integer (pc + 2, 2);
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||
|
||
if (pc + 4 < current_pc && cache->locals == 0)
|
||
{
|
||
op = read_memory_unsigned_integer (pc + 4, 2);
|
||
if (op == P_ADDAL_SP)
|
||
{
|
||
cache->locals = read_memory_integer (pc + 6, 4);
|
||
return pc + 10;
|
||
}
|
||
}
|
||
|
||
return pc + 4;
|
||
}
|
||
else if (op == P_LINKL_FP)
|
||
{
|
||
/* link.l %fp, #-N */
|
||
cache->locals = -read_memory_integer (pc + 2, 4);
|
||
return pc + 6;
|
||
}
|
||
else
|
||
{
|
||
/* pea (%fp); movea.l %sp, %fp */
|
||
cache->locals = 0;
|
||
|
||
if (pc + 2 < current_pc)
|
||
{
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||
op = read_memory_unsigned_integer (pc + 2, 2);
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||
|
||
if (op == P_MOVEAL_SP_FP)
|
||
{
|
||
/* move.l %sp, %fp */
|
||
return pc + 4;
|
||
}
|
||
}
|
||
|
||
return pc + 2;
|
||
}
|
||
}
|
||
else if ((op & 0170777) == P_SUBQW_SP || (op & 0170777) == P_SUBQL_SP)
|
||
{
|
||
/* subq.[wl] #N,%sp */
|
||
/* subq.[wl] #8,%sp; subq.[wl] #N,%sp */
|
||
cache->locals = (op & 07000) == 0 ? 8 : (op & 07000) >> 9;
|
||
if (pc + 2 < current_pc)
|
||
{
|
||
op = read_memory_unsigned_integer (pc + 2, 2);
|
||
if ((op & 0170777) == P_SUBQW_SP || (op & 0170777) == P_SUBQL_SP)
|
||
{
|
||
cache->locals += (op & 07000) == 0 ? 8 : (op & 07000) >> 9;
|
||
return pc + 4;
|
||
}
|
||
}
|
||
return pc + 2;
|
||
}
|
||
else if (op == P_ADDAW_SP || op == P_LEA_SP_SP)
|
||
{
|
||
/* adda.w #-N,%sp */
|
||
/* lea (-N,%sp),%sp */
|
||
cache->locals = -read_memory_integer (pc + 2, 2);
|
||
return pc + 4;
|
||
}
|
||
else if (op == P_ADDAL_SP)
|
||
{
|
||
/* adda.l #-N,%sp */
|
||
cache->locals = -read_memory_integer (pc + 2, 4);
|
||
return pc + 6;
|
||
}
|
||
|
||
return pc;
|
||
}
|
||
|
||
/* Check whether PC points at code that saves registers on the stack.
|
||
If so, it updates CACHE and returns the address of the first
|
||
instruction after the register saves or CURRENT_PC, whichever is
|
||
smaller. Otherwise, return PC. */
|
||
|
||
static CORE_ADDR
|
||
m68k_analyze_register_saves (CORE_ADDR pc, CORE_ADDR current_pc,
|
||
struct m68k_frame_cache *cache)
|
||
{
|
||
if (cache->locals >= 0)
|
||
{
|
||
CORE_ADDR offset;
|
||
int op;
|
||
int i, mask, regno;
|
||
|
||
offset = -4 - cache->locals;
|
||
while (pc < current_pc)
|
||
{
|
||
op = read_memory_unsigned_integer (pc, 2);
|
||
if (op == P_FMOVEMX_SP)
|
||
{
|
||
/* fmovem.x REGS,-(%sp) */
|
||
op = read_memory_unsigned_integer (pc + 2, 2);
|
||
if ((op & 0xff00) == 0xe000)
|
||
{
|
||
mask = op & 0xff;
|
||
for (i = 0; i < 16; i++, mask >>= 1)
|
||
{
|
||
if (mask & 1)
|
||
{
|
||
cache->saved_regs[i + M68K_FP0_REGNUM] = offset;
|
||
offset -= 12;
|
||
}
|
||
}
|
||
pc += 4;
|
||
}
|
||
else
|
||
break;
|
||
}
|
||
else if ((op & 0170677) == P_MOVEL_SP)
|
||
{
|
||
/* move.l %R,-(%sp) */
|
||
regno = ((op & 07000) >> 9) | ((op & 0100) >> 3);
|
||
cache->saved_regs[regno] = offset;
|
||
offset -= 4;
|
||
pc += 2;
|
||
}
|
||
else if (op == P_MOVEML_SP)
|
||
{
|
||
/* movem.l REGS,-(%sp) */
|
||
mask = read_memory_unsigned_integer (pc + 2, 2);
|
||
for (i = 0; i < 16; i++, mask >>= 1)
|
||
{
|
||
if (mask & 1)
|
||
{
|
||
cache->saved_regs[15 - i] = offset;
|
||
offset -= 4;
|
||
}
|
||
}
|
||
pc += 4;
|
||
}
|
||
else
|
||
break;
|
||
}
|
||
}
|
||
|
||
return pc;
|
||
}
|
||
|
||
|
||
/* Do a full analysis of the prologue at PC and update CACHE
|
||
accordingly. Bail out early if CURRENT_PC is reached. Return the
|
||
address where the analysis stopped.
|
||
|
||
We handle all cases that can be generated by gcc.
|
||
|
||
For allocating a stack frame:
|
||
|
||
link.w %a6,#-N
|
||
link.l %a6,#-N
|
||
pea (%fp); move.l %sp,%fp
|
||
link.w %a6,#0; add.l #-N,%sp
|
||
subq.l #N,%sp
|
||
subq.w #N,%sp
|
||
subq.w #8,%sp; subq.w #N-8,%sp
|
||
add.w #-N,%sp
|
||
lea (-N,%sp),%sp
|
||
add.l #-N,%sp
|
||
|
||
For saving registers:
|
||
|
||
fmovem.x REGS,-(%sp)
|
||
move.l R1,-(%sp)
|
||
move.l R1,-(%sp); move.l R2,-(%sp)
|
||
movem.l REGS,-(%sp)
|
||
|
||
For setting up the PIC register:
|
||
|
||
lea (%pc,N),%a5
|
||
|
||
*/
|
||
|
||
static CORE_ADDR
|
||
m68k_analyze_prologue (CORE_ADDR pc, CORE_ADDR current_pc,
|
||
struct m68k_frame_cache *cache)
|
||
{
|
||
unsigned int op;
|
||
|
||
pc = m68k_analyze_frame_setup (pc, current_pc, cache);
|
||
pc = m68k_analyze_register_saves (pc, current_pc, cache);
|
||
if (pc >= current_pc)
|
||
return current_pc;
|
||
|
||
/* Check for GOT setup. */
|
||
op = read_memory_unsigned_integer (pc, 4);
|
||
if (op == P_LEA_PC_A5)
|
||
{
|
||
/* lea (%pc,N),%a5 */
|
||
return pc + 6;
|
||
}
|
||
|
||
return pc;
|
||
}
|
||
|
||
/* Return PC of first real instruction. */
|
||
|
||
static CORE_ADDR
|
||
m68k_skip_prologue (CORE_ADDR start_pc)
|
||
{
|
||
struct m68k_frame_cache cache;
|
||
CORE_ADDR pc;
|
||
int op;
|
||
|
||
cache.locals = -1;
|
||
pc = m68k_analyze_prologue (start_pc, (CORE_ADDR) -1, &cache);
|
||
if (cache.locals < 0)
|
||
return start_pc;
|
||
return pc;
|
||
}
|
||
|
||
static CORE_ADDR
|
||
m68k_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
|
||
{
|
||
char buf[8];
|
||
|
||
frame_unwind_register (next_frame, PC_REGNUM, buf);
|
||
return extract_typed_address (buf, builtin_type_void_func_ptr);
|
||
}
|
||
|
||
/* Normal frames. */
|
||
|
||
static struct m68k_frame_cache *
|
||
m68k_frame_cache (struct frame_info *next_frame, void **this_cache)
|
||
{
|
||
struct m68k_frame_cache *cache;
|
||
char buf[4];
|
||
int i;
|
||
|
||
if (*this_cache)
|
||
return *this_cache;
|
||
|
||
cache = m68k_alloc_frame_cache ();
|
||
*this_cache = cache;
|
||
|
||
/* In principle, for normal frames, %fp holds the frame pointer,
|
||
which holds the base address for the current stack frame.
|
||
However, for functions that don't need it, the frame pointer is
|
||
optional. For these "frameless" functions the frame pointer is
|
||
actually the frame pointer of the calling frame. Signal
|
||
trampolines are just a special case of a "frameless" function.
|
||
They (usually) share their frame pointer with the frame that was
|
||
in progress when the signal occurred. */
|
||
|
||
frame_unwind_register (next_frame, M68K_FP_REGNUM, buf);
|
||
cache->base = extract_unsigned_integer (buf, 4);
|
||
if (cache->base == 0)
|
||
return cache;
|
||
|
||
/* For normal frames, %pc is stored at 4(%fp). */
|
||
cache->saved_regs[M68K_PC_REGNUM] = 4;
|
||
|
||
cache->pc = frame_func_unwind (next_frame);
|
||
if (cache->pc != 0)
|
||
m68k_analyze_prologue (cache->pc, frame_pc_unwind (next_frame), cache);
|
||
|
||
if (cache->locals < 0)
|
||
{
|
||
/* We didn't find a valid frame, which means that CACHE->base
|
||
currently holds the frame pointer for our calling frame. If
|
||
we're at the start of a function, or somewhere half-way its
|
||
prologue, the function's frame probably hasn't been fully
|
||
setup yet. Try to reconstruct the base address for the stack
|
||
frame by looking at the stack pointer. For truly "frameless"
|
||
functions this might work too. */
|
||
|
||
frame_unwind_register (next_frame, M68K_SP_REGNUM, buf);
|
||
cache->base = extract_unsigned_integer (buf, 4) + cache->sp_offset;
|
||
}
|
||
|
||
/* Now that we have the base address for the stack frame we can
|
||
calculate the value of %sp in the calling frame. */
|
||
cache->saved_sp = cache->base + 8;
|
||
|
||
/* Adjust all the saved registers such that they contain addresses
|
||
instead of offsets. */
|
||
for (i = 0; i < M68K_NUM_REGS; i++)
|
||
if (cache->saved_regs[i] != -1)
|
||
cache->saved_regs[i] += cache->base;
|
||
|
||
return cache;
|
||
}
|
||
|
||
static void
|
||
m68k_frame_this_id (struct frame_info *next_frame, void **this_cache,
|
||
struct frame_id *this_id)
|
||
{
|
||
struct m68k_frame_cache *cache = m68k_frame_cache (next_frame, this_cache);
|
||
|
||
/* This marks the outermost frame. */
|
||
if (cache->base == 0)
|
||
return;
|
||
|
||
/* See the end of m68k_push_dummy_call. */
|
||
*this_id = frame_id_build (cache->base + 8, cache->pc);
|
||
}
|
||
|
||
static void
|
||
m68k_frame_prev_register (struct frame_info *next_frame, void **this_cache,
|
||
int regnum, int *optimizedp,
|
||
enum lval_type *lvalp, CORE_ADDR *addrp,
|
||
int *realnump, void *valuep)
|
||
{
|
||
struct m68k_frame_cache *cache = m68k_frame_cache (next_frame, this_cache);
|
||
|
||
gdb_assert (regnum >= 0);
|
||
|
||
if (regnum == M68K_SP_REGNUM && cache->saved_sp)
|
||
{
|
||
*optimizedp = 0;
|
||
*lvalp = not_lval;
|
||
*addrp = 0;
|
||
*realnump = -1;
|
||
if (valuep)
|
||
{
|
||
/* Store the value. */
|
||
store_unsigned_integer (valuep, 4, cache->saved_sp);
|
||
}
|
||
return;
|
||
}
|
||
|
||
if (regnum < M68K_NUM_REGS && cache->saved_regs[regnum] != -1)
|
||
{
|
||
*optimizedp = 0;
|
||
*lvalp = lval_memory;
|
||
*addrp = cache->saved_regs[regnum];
|
||
*realnump = -1;
|
||
if (valuep)
|
||
{
|
||
/* Read the value in from memory. */
|
||
read_memory (*addrp, valuep,
|
||
register_size (current_gdbarch, regnum));
|
||
}
|
||
return;
|
||
}
|
||
|
||
frame_register_unwind (next_frame, regnum,
|
||
optimizedp, lvalp, addrp, realnump, valuep);
|
||
}
|
||
|
||
static const struct frame_unwind m68k_frame_unwind =
|
||
{
|
||
NORMAL_FRAME,
|
||
m68k_frame_this_id,
|
||
m68k_frame_prev_register
|
||
};
|
||
|
||
static const struct frame_unwind *
|
||
m68k_frame_sniffer (struct frame_info *next_frame)
|
||
{
|
||
return &m68k_frame_unwind;
|
||
}
|
||
|
||
/* Signal trampolines. */
|
||
|
||
static struct m68k_frame_cache *
|
||
m68k_sigtramp_frame_cache (struct frame_info *next_frame, void **this_cache)
|
||
{
|
||
struct m68k_frame_cache *cache;
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
|
||
struct m68k_sigtramp_info info;
|
||
char buf[4];
|
||
int i;
|
||
|
||
if (*this_cache)
|
||
return *this_cache;
|
||
|
||
cache = m68k_alloc_frame_cache ();
|
||
|
||
frame_unwind_register (next_frame, M68K_SP_REGNUM, buf);
|
||
cache->base = extract_unsigned_integer (buf, 4) - 4;
|
||
|
||
info = tdep->get_sigtramp_info (next_frame);
|
||
|
||
for (i = 0; i < M68K_NUM_REGS; i++)
|
||
if (info.sc_reg_offset[i] != -1)
|
||
cache->saved_regs[i] = info.sigcontext_addr + info.sc_reg_offset[i];
|
||
|
||
*this_cache = cache;
|
||
return cache;
|
||
}
|
||
|
||
static void
|
||
m68k_sigtramp_frame_this_id (struct frame_info *next_frame, void **this_cache,
|
||
struct frame_id *this_id)
|
||
{
|
||
struct m68k_frame_cache *cache =
|
||
m68k_sigtramp_frame_cache (next_frame, this_cache);
|
||
|
||
/* See the end of m68k_push_dummy_call. */
|
||
*this_id = frame_id_build (cache->base + 8, frame_pc_unwind (next_frame));
|
||
}
|
||
|
||
static void
|
||
m68k_sigtramp_frame_prev_register (struct frame_info *next_frame,
|
||
void **this_cache,
|
||
int regnum, int *optimizedp,
|
||
enum lval_type *lvalp, CORE_ADDR *addrp,
|
||
int *realnump, void *valuep)
|
||
{
|
||
/* Make sure we've initialized the cache. */
|
||
m68k_sigtramp_frame_cache (next_frame, this_cache);
|
||
|
||
m68k_frame_prev_register (next_frame, this_cache, regnum,
|
||
optimizedp, lvalp, addrp, realnump, valuep);
|
||
}
|
||
|
||
static const struct frame_unwind m68k_sigtramp_frame_unwind =
|
||
{
|
||
SIGTRAMP_FRAME,
|
||
m68k_sigtramp_frame_this_id,
|
||
m68k_sigtramp_frame_prev_register
|
||
};
|
||
|
||
static const struct frame_unwind *
|
||
m68k_sigtramp_frame_sniffer (struct frame_info *next_frame)
|
||
{
|
||
CORE_ADDR pc = frame_pc_unwind (next_frame);
|
||
char *name;
|
||
|
||
/* We shouldn't even bother to try if the OSABI didn't register
|
||
a get_sigtramp_info handler. */
|
||
if (!gdbarch_tdep (current_gdbarch)->get_sigtramp_info)
|
||
return NULL;
|
||
|
||
find_pc_partial_function (pc, &name, NULL, NULL);
|
||
if (PC_IN_SIGTRAMP (pc, name))
|
||
return &m68k_sigtramp_frame_unwind;
|
||
|
||
return NULL;
|
||
}
|
||
|
||
static CORE_ADDR
|
||
m68k_frame_base_address (struct frame_info *next_frame, void **this_cache)
|
||
{
|
||
struct m68k_frame_cache *cache = m68k_frame_cache (next_frame, this_cache);
|
||
|
||
return cache->base;
|
||
}
|
||
|
||
static const struct frame_base m68k_frame_base =
|
||
{
|
||
&m68k_frame_unwind,
|
||
m68k_frame_base_address,
|
||
m68k_frame_base_address,
|
||
m68k_frame_base_address
|
||
};
|
||
|
||
static struct frame_id
|
||
m68k_unwind_dummy_id (struct gdbarch *gdbarch, struct frame_info *next_frame)
|
||
{
|
||
char buf[4];
|
||
CORE_ADDR fp;
|
||
|
||
frame_unwind_register (next_frame, M68K_FP_REGNUM, buf);
|
||
fp = extract_unsigned_integer (buf, 4);
|
||
|
||
/* See the end of m68k_push_dummy_call. */
|
||
return frame_id_build (fp + 8, frame_pc_unwind (next_frame));
|
||
}
|
||
|
||
#ifdef USE_PROC_FS /* Target dependent support for /proc */
|
||
|
||
#include <sys/procfs.h>
|
||
|
||
/* Prototypes for supply_gregset etc. */
|
||
#include "gregset.h"
|
||
|
||
/* The /proc interface divides the target machine's register set up into
|
||
two different sets, the general register set (gregset) and the floating
|
||
point register set (fpregset). For each set, there is an ioctl to get
|
||
the current register set and another ioctl to set the current values.
|
||
|
||
The actual structure passed through the ioctl interface is, of course,
|
||
naturally machine dependent, and is different for each set of registers.
|
||
For the m68k for example, the general register set is typically defined
|
||
by:
|
||
|
||
typedef int gregset_t[18];
|
||
|
||
#define R_D0 0
|
||
...
|
||
#define R_PS 17
|
||
|
||
and the floating point set by:
|
||
|
||
typedef struct fpregset {
|
||
int f_pcr;
|
||
int f_psr;
|
||
int f_fpiaddr;
|
||
int f_fpregs[8][3]; (8 regs, 96 bits each)
|
||
} fpregset_t;
|
||
|
||
These routines provide the packing and unpacking of gregset_t and
|
||
fpregset_t formatted data.
|
||
|
||
*/
|
||
|
||
/* Atari SVR4 has R_SR but not R_PS */
|
||
|
||
#if !defined (R_PS) && defined (R_SR)
|
||
#define R_PS R_SR
|
||
#endif
|
||
|
||
/* Given a pointer to a general register set in /proc format (gregset_t *),
|
||
unpack the register contents and supply them as gdb's idea of the current
|
||
register values. */
|
||
|
||
void
|
||
supply_gregset (gregset_t *gregsetp)
|
||
{
|
||
int regi;
|
||
greg_t *regp = (greg_t *) gregsetp;
|
||
|
||
for (regi = 0; regi < R_PC; regi++)
|
||
{
|
||
supply_register (regi, (char *) (regp + regi));
|
||
}
|
||
supply_register (PS_REGNUM, (char *) (regp + R_PS));
|
||
supply_register (PC_REGNUM, (char *) (regp + R_PC));
|
||
}
|
||
|
||
void
|
||
fill_gregset (gregset_t *gregsetp, int regno)
|
||
{
|
||
int regi;
|
||
greg_t *regp = (greg_t *) gregsetp;
|
||
|
||
for (regi = 0; regi < R_PC; regi++)
|
||
{
|
||
if (regno == -1 || regno == regi)
|
||
regcache_collect (regi, regp + regi);
|
||
}
|
||
if (regno == -1 || regno == PS_REGNUM)
|
||
regcache_collect (PS_REGNUM, regp + R_PS);
|
||
if (regno == -1 || regno == PC_REGNUM)
|
||
regcache_collect (PC_REGNUM, regp + R_PC);
|
||
}
|
||
|
||
#if defined (FP0_REGNUM)
|
||
|
||
/* Given a pointer to a floating point register set in /proc format
|
||
(fpregset_t *), unpack the register contents and supply them as gdb's
|
||
idea of the current floating point register values. */
|
||
|
||
void
|
||
supply_fpregset (fpregset_t *fpregsetp)
|
||
{
|
||
int regi;
|
||
char *from;
|
||
|
||
for (regi = FP0_REGNUM; regi < M68K_FPC_REGNUM; regi++)
|
||
{
|
||
from = (char *) &(fpregsetp->f_fpregs[regi - FP0_REGNUM][0]);
|
||
supply_register (regi, from);
|
||
}
|
||
supply_register (M68K_FPC_REGNUM, (char *) &(fpregsetp->f_pcr));
|
||
supply_register (M68K_FPS_REGNUM, (char *) &(fpregsetp->f_psr));
|
||
supply_register (M68K_FPI_REGNUM, (char *) &(fpregsetp->f_fpiaddr));
|
||
}
|
||
|
||
/* Given a pointer to a floating point register set in /proc format
|
||
(fpregset_t *), update the register specified by REGNO from gdb's idea
|
||
of the current floating point register set. If REGNO is -1, update
|
||
them all. */
|
||
|
||
void
|
||
fill_fpregset (fpregset_t *fpregsetp, int regno)
|
||
{
|
||
int regi;
|
||
|
||
for (regi = FP0_REGNUM; regi < M68K_FPC_REGNUM; regi++)
|
||
{
|
||
if (regno == -1 || regno == regi)
|
||
regcache_collect (regi, &fpregsetp->f_fpregs[regi - FP0_REGNUM][0]);
|
||
}
|
||
if (regno == -1 || regno == M68K_FPC_REGNUM)
|
||
regcache_collect (M68K_FPC_REGNUM, &fpregsetp->f_pcr);
|
||
if (regno == -1 || regno == M68K_FPS_REGNUM)
|
||
regcache_collect (M68K_FPS_REGNUM, &fpregsetp->f_psr);
|
||
if (regno == -1 || regno == M68K_FPI_REGNUM)
|
||
regcache_collect (M68K_FPI_REGNUM, &fpregsetp->f_fpiaddr);
|
||
}
|
||
|
||
#endif /* defined (FP0_REGNUM) */
|
||
|
||
#endif /* USE_PROC_FS */
|
||
|
||
/* Figure out where the longjmp will land. Slurp the args out of the stack.
|
||
We expect the first arg to be a pointer to the jmp_buf structure from which
|
||
we extract the pc (JB_PC) that we will land at. The pc is copied into PC.
|
||
This routine returns true on success. */
|
||
|
||
int
|
||
m68k_get_longjmp_target (CORE_ADDR *pc)
|
||
{
|
||
char *buf;
|
||
CORE_ADDR sp, jb_addr;
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
|
||
|
||
if (tdep->jb_pc < 0)
|
||
{
|
||
internal_error (__FILE__, __LINE__,
|
||
"m68k_get_longjmp_target: not implemented");
|
||
return 0;
|
||
}
|
||
|
||
buf = alloca (TARGET_PTR_BIT / TARGET_CHAR_BIT);
|
||
sp = read_register (SP_REGNUM);
|
||
|
||
if (target_read_memory (sp + SP_ARG0, /* Offset of first arg on stack */
|
||
buf, TARGET_PTR_BIT / TARGET_CHAR_BIT))
|
||
return 0;
|
||
|
||
jb_addr = extract_unsigned_integer (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
|
||
|
||
if (target_read_memory (jb_addr + tdep->jb_pc * tdep->jb_elt_size, buf,
|
||
TARGET_PTR_BIT / TARGET_CHAR_BIT))
|
||
return 0;
|
||
|
||
*pc = extract_unsigned_integer (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
|
||
return 1;
|
||
}
|
||
|
||
#ifdef SYSCALL_TRAP
|
||
/* Immediately after a function call, return the saved pc before the frame
|
||
is setup. For sun3's, we check for the common case of being inside of a
|
||
system call, and if so, we know that Sun pushes the call # on the stack
|
||
prior to doing the trap. */
|
||
|
||
static CORE_ADDR
|
||
m68k_saved_pc_after_call (struct frame_info *frame)
|
||
{
|
||
int op;
|
||
|
||
op = read_memory_unsigned_integer (frame->pc - SYSCALL_TRAP_OFFSET, 2);
|
||
|
||
if (op == SYSCALL_TRAP)
|
||
return read_memory_unsigned_integer (read_register (SP_REGNUM) + 4, 4);
|
||
else
|
||
return read_memory_unsigned_integer (read_register (SP_REGNUM), 4);
|
||
}
|
||
#endif /* SYSCALL_TRAP */
|
||
|
||
/* Function: m68k_gdbarch_init
|
||
Initializer function for the m68k gdbarch vector.
|
||
Called by gdbarch. Sets up the gdbarch vector(s) for this target. */
|
||
|
||
static struct gdbarch *
|
||
m68k_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
|
||
{
|
||
struct gdbarch_tdep *tdep = NULL;
|
||
struct gdbarch *gdbarch;
|
||
|
||
/* find a candidate among the list of pre-declared architectures. */
|
||
arches = gdbarch_list_lookup_by_info (arches, &info);
|
||
if (arches != NULL)
|
||
return (arches->gdbarch);
|
||
|
||
tdep = xmalloc (sizeof (struct gdbarch_tdep));
|
||
gdbarch = gdbarch_alloc (&info, tdep);
|
||
|
||
set_gdbarch_long_double_format (gdbarch, &floatformat_m68881_ext);
|
||
set_gdbarch_long_double_bit (gdbarch, 96);
|
||
|
||
set_gdbarch_function_start_offset (gdbarch, 0);
|
||
|
||
set_gdbarch_skip_prologue (gdbarch, m68k_skip_prologue);
|
||
#ifdef SYSCALL_TRAP
|
||
set_gdbarch_deprecated_saved_pc_after_call (gdbarch, m68k_saved_pc_after_call);
|
||
#endif
|
||
set_gdbarch_breakpoint_from_pc (gdbarch, m68k_local_breakpoint_from_pc);
|
||
|
||
/* Stack grows down. */
|
||
set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
|
||
set_gdbarch_parm_boundary (gdbarch, 32);
|
||
|
||
set_gdbarch_believe_pcc_promotion (gdbarch, 1);
|
||
set_gdbarch_decr_pc_after_break (gdbarch, 2);
|
||
|
||
set_gdbarch_extract_return_value (gdbarch, m68k_extract_return_value);
|
||
set_gdbarch_store_return_value (gdbarch, m68k_store_return_value);
|
||
set_gdbarch_extract_struct_value_address (gdbarch,
|
||
m68k_extract_struct_value_address);
|
||
set_gdbarch_use_struct_convention (gdbarch, m68k_use_struct_convention);
|
||
|
||
set_gdbarch_frameless_function_invocation (gdbarch,
|
||
m68k_frameless_function_invocation);
|
||
set_gdbarch_frame_args_skip (gdbarch, 8);
|
||
|
||
set_gdbarch_register_type (gdbarch, m68k_register_type);
|
||
set_gdbarch_register_name (gdbarch, m68k_register_name);
|
||
set_gdbarch_num_regs (gdbarch, 29);
|
||
set_gdbarch_register_bytes_ok (gdbarch, m68k_register_bytes_ok);
|
||
set_gdbarch_sp_regnum (gdbarch, M68K_SP_REGNUM);
|
||
set_gdbarch_pc_regnum (gdbarch, M68K_PC_REGNUM);
|
||
set_gdbarch_ps_regnum (gdbarch, M68K_PS_REGNUM);
|
||
set_gdbarch_fp0_regnum (gdbarch, M68K_FP0_REGNUM);
|
||
|
||
set_gdbarch_push_dummy_call (gdbarch, m68k_push_dummy_call);
|
||
|
||
/* Disassembler. */
|
||
set_gdbarch_print_insn (gdbarch, print_insn_m68k);
|
||
|
||
#if defined JB_PC && defined JB_ELEMENT_SIZE
|
||
tdep->jb_pc = JB_PC;
|
||
tdep->jb_elt_size = JB_ELEMENT_SIZE;
|
||
#else
|
||
tdep->jb_pc = -1;
|
||
#endif
|
||
tdep->get_sigtramp_info = NULL;
|
||
tdep->struct_return = pcc_struct_return;
|
||
|
||
/* Frame unwinder. */
|
||
set_gdbarch_unwind_dummy_id (gdbarch, m68k_unwind_dummy_id);
|
||
set_gdbarch_unwind_pc (gdbarch, m68k_unwind_pc);
|
||
|
||
/* Hook in the DWARF CFI frame unwinder. */
|
||
frame_unwind_append_sniffer (gdbarch, dwarf2_frame_sniffer);
|
||
|
||
frame_base_set_default (gdbarch, &m68k_frame_base);
|
||
|
||
/* Hook in ABI-specific overrides, if they have been registered. */
|
||
gdbarch_init_osabi (info, gdbarch);
|
||
|
||
/* Now we have tuned the configuration, set a few final things,
|
||
based on what the OS ABI has told us. */
|
||
|
||
if (tdep->jb_pc >= 0)
|
||
set_gdbarch_get_longjmp_target (gdbarch, m68k_get_longjmp_target);
|
||
|
||
frame_unwind_append_sniffer (gdbarch, m68k_sigtramp_frame_sniffer);
|
||
frame_unwind_append_sniffer (gdbarch, m68k_frame_sniffer);
|
||
|
||
return gdbarch;
|
||
}
|
||
|
||
|
||
static void
|
||
m68k_dump_tdep (struct gdbarch *current_gdbarch, struct ui_file *file)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
|
||
|
||
if (tdep == NULL)
|
||
return;
|
||
}
|
||
|
||
extern initialize_file_ftype _initialize_m68k_tdep; /* -Wmissing-prototypes */
|
||
|
||
void
|
||
_initialize_m68k_tdep (void)
|
||
{
|
||
gdbarch_register (bfd_arch_m68k, m68k_gdbarch_init, m68k_dump_tdep);
|
||
}
|