-/* Target dependent code for the Motorola 68000 series.
- Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1999, 2000, 2001
- Free Software Foundation, Inc.
+/* Target-dependent code for the Motorola 68000 series.
+
+ Copyright (C) 1990-2019 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., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
+#include "dwarf2-frame.h"
#include "frame.h"
+#include "frame-base.h"
+#include "frame-unwind.h"
+#include "gdbtypes.h"
#include "symtab.h"
#include "gdbcore.h"
#include "value.h"
-#include "gdb_string.h"
#include "inferior.h"
#include "regcache.h"
+#include "arch-utils.h"
+#include "osabi.h"
+#include "dis-asm.h"
+#include "target-descriptions.h"
+#include "floatformat.h"
+#include "target-float.h"
+
+#include "m68k-tdep.h"
\f
#define P_LINKL_FP 0x480e
#define P_LINKW_FP 0x4e56
#define P_PEA_FP 0x4856
-#define P_MOVL_SP_FP 0x2c4f
-#define P_MOVL 0x207c
-#define P_JSR 0x4eb9
-#define P_BSR 0x61ff
-#define P_LEAL 0x43fb
-#define P_MOVML 0x48ef
-#define P_FMOVM 0xf237
-#define P_TRAP 0x4e40
-
-void m68k_frame_init_saved_regs (struct frame_info *frame_info);
-
-/* The only reason this is here is the tm-altos.h reference below. It
- was moved back here from tm-m68k.h. FIXME? */
-
-extern CORE_ADDR
-altos_skip_prologue (CORE_ADDR pc)
-{
- register int op = read_memory_integer (pc, 2);
- if (op == P_LINKW_FP)
- pc += 4; /* Skip link #word */
- else if (op == P_LINKL_FP)
- pc += 6; /* Skip link #long */
- /* Not sure why branches are here. */
- /* From tm-altos.h */
- else if (op == 0060000)
- pc += 4; /* Skip bra #word */
- else if (op == 00600377)
- pc += 6; /* skip bra #long */
- else if ((op & 0177400) == 0060000)
- pc += 2; /* skip bra #char */
- return pc;
-}
+#define P_MOVEAL_SP_FP 0x2c4f
+#define P_ADDAW_SP 0xdefc
+#define P_ADDAL_SP 0xdffc
+#define P_SUBQW_SP 0x514f
+#define P_SUBQL_SP 0x518f
+#define P_LEA_SP_SP 0x4fef
+#define P_LEA_PC_A5 0x4bfb0170
+#define P_FMOVEMX_SP 0xf227
+#define P_MOVEL_SP 0x2f00
+#define P_MOVEML_SP 0x48e7
+
+/* Offset from SP to first arg on stack at first instruction of a function. */
+#define SP_ARG0 (1 * 4)
+
+#if !defined (BPT_VECTOR)
+#define BPT_VECTOR 0xf
+#endif
-int
-delta68_in_sigtramp (CORE_ADDR pc, char *name)
-{
- if (name != NULL)
- return strcmp (name, "_sigcode") == 0;
- else
- return 0;
-}
+constexpr gdb_byte m68k_break_insn[] = {0x4e, (0x40 | BPT_VECTOR)};
+
+typedef BP_MANIPULATION (m68k_break_insn) m68k_breakpoint;
+\f
-CORE_ADDR
-delta68_frame_args_address (struct frame_info *frame_info)
+/* Construct types for ISA-specific registers. */
+static struct type *
+m68k_ps_type (struct gdbarch *gdbarch)
{
- /* we assume here that the only frameless functions are the system calls
- or other functions who do not put anything on the stack. */
- if (frame_info->signal_handler_caller)
- return frame_info->frame + 12;
- else if (frameless_look_for_prologue (frame_info))
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ if (!tdep->m68k_ps_type)
{
- /* Check for an interrupted system call */
- if (frame_info->next && frame_info->next->signal_handler_caller)
- return frame_info->next->frame + 16;
- else
- return frame_info->frame + 4;
+ struct type *type;
+
+ type = arch_flags_type (gdbarch, "builtin_type_m68k_ps", 32);
+ append_flags_type_flag (type, 0, "C");
+ append_flags_type_flag (type, 1, "V");
+ append_flags_type_flag (type, 2, "Z");
+ append_flags_type_flag (type, 3, "N");
+ append_flags_type_flag (type, 4, "X");
+ append_flags_type_flag (type, 8, "I0");
+ append_flags_type_flag (type, 9, "I1");
+ append_flags_type_flag (type, 10, "I2");
+ append_flags_type_flag (type, 12, "M");
+ append_flags_type_flag (type, 13, "S");
+ append_flags_type_flag (type, 14, "T0");
+ append_flags_type_flag (type, 15, "T1");
+
+ tdep->m68k_ps_type = type;
}
- else
- return frame_info->frame;
+
+ return tdep->m68k_ps_type;
}
-CORE_ADDR
-delta68_frame_saved_pc (struct frame_info *frame_info)
+static struct type *
+m68881_ext_type (struct gdbarch *gdbarch)
{
- return read_memory_integer (delta68_frame_args_address (frame_info) + 4, 4);
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ if (!tdep->m68881_ext_type)
+ tdep->m68881_ext_type
+ = arch_float_type (gdbarch, -1, "builtin_type_m68881_ext",
+ floatformats_m68881_ext);
+
+ return tdep->m68881_ext_type;
}
-/* Return number of args passed to a frame.
- Can return -1, meaning no way to tell. */
+/* Return the GDB type object for the "standard" data type of data in
+ register N. This should be int for D0-D7, SR, FPCONTROL and
+ FPSTATUS, long double for FP0-FP7, and void pointer for all others
+ (A0-A7, PC, FPIADDR). Note, for registers which contain
+ addresses return pointer to void, not pointer to char, because we
+ don't want to attempt to print the string after printing the
+ address. */
-int
-isi_frame_num_args (struct frame_info *fi)
+static struct type *
+m68k_register_type (struct gdbarch *gdbarch, int regnum)
{
- int val;
- CORE_ADDR pc = FRAME_SAVED_PC (fi);
- int insn = 0177777 & read_memory_integer (pc, 2);
- val = 0;
- if (insn == 0047757 || insn == 0157374) /* lea W(sp),sp or addaw #W,sp */
- val = read_memory_integer (pc + 2, 2);
- else if ((insn & 0170777) == 0050217 /* addql #N, sp */
- || (insn & 0170777) == 0050117) /* addqw */
- {
- val = (insn >> 9) & 7;
- if (val == 0)
- val = 8;
- }
- else if (insn == 0157774) /* addal #WW, sp */
- val = read_memory_integer (pc + 2, 4);
- val >>= 2;
- return val;
-}
-
-int
-delta68_frame_num_args (struct frame_info *fi)
-{
- int val;
- CORE_ADDR pc = FRAME_SAVED_PC (fi);
- int insn = 0177777 & read_memory_integer (pc, 2);
- val = 0;
- if (insn == 0047757 || insn == 0157374) /* lea W(sp),sp or addaw #W,sp */
- val = read_memory_integer (pc + 2, 2);
- else if ((insn & 0170777) == 0050217 /* addql #N, sp */
- || (insn & 0170777) == 0050117) /* addqw */
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ if (tdep->fpregs_present)
{
- val = (insn >> 9) & 7;
- if (val == 0)
- val = 8;
+ if (regnum >= gdbarch_fp0_regnum (gdbarch)
+ && regnum <= gdbarch_fp0_regnum (gdbarch) + 7)
+ {
+ if (tdep->flavour == m68k_coldfire_flavour)
+ return builtin_type (gdbarch)->builtin_double;
+ else
+ return m68881_ext_type (gdbarch);
+ }
+
+ if (regnum == M68K_FPI_REGNUM)
+ return builtin_type (gdbarch)->builtin_func_ptr;
+
+ if (regnum == M68K_FPC_REGNUM || regnum == M68K_FPS_REGNUM)
+ return builtin_type (gdbarch)->builtin_int32;
}
- else if (insn == 0157774) /* addal #WW, sp */
- val = read_memory_integer (pc + 2, 4);
- val >>= 2;
- return val;
-}
-
-int
-news_frame_num_args (struct frame_info *fi)
-{
- int val;
- CORE_ADDR pc = FRAME_SAVED_PC (fi);
- int insn = 0177777 & read_memory_integer (pc, 2);
- val = 0;
- if (insn == 0047757 || insn == 0157374) /* lea W(sp),sp or addaw #W,sp */
- val = read_memory_integer (pc + 2, 2);
- else if ((insn & 0170777) == 0050217 /* addql #N, sp */
- || (insn & 0170777) == 0050117) /* addqw */
+ else
{
- val = (insn >> 9) & 7;
- if (val == 0)
- val = 8;
+ if (regnum >= M68K_FP0_REGNUM && regnum <= M68K_FPI_REGNUM)
+ return builtin_type (gdbarch)->builtin_int0;
}
- else if (insn == 0157774) /* addal #WW, sp */
- val = read_memory_integer (pc + 2, 4);
- val >>= 2;
- return val;
+
+ if (regnum == gdbarch_pc_regnum (gdbarch))
+ return builtin_type (gdbarch)->builtin_func_ptr;
+
+ if (regnum >= M68K_A0_REGNUM && regnum <= M68K_A0_REGNUM + 7)
+ return builtin_type (gdbarch)->builtin_data_ptr;
+
+ if (regnum == M68K_PS_REGNUM)
+ return m68k_ps_type (gdbarch);
+
+ return builtin_type (gdbarch)->builtin_int32;
}
-/* Insert the specified number of args and function address
- into a call sequence of the above form stored at DUMMYNAME.
- We use the BFD routines to store a big-endian value of known size. */
+static const char *m68k_register_names[] = {
+ "d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7",
+ "a0", "a1", "a2", "a3", "a4", "a5", "fp", "sp",
+ "ps", "pc",
+ "fp0", "fp1", "fp2", "fp3", "fp4", "fp5", "fp6", "fp7",
+ "fpcontrol", "fpstatus", "fpiaddr"
+ };
-void
-m68k_fix_call_dummy(char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs,
- struct value **args, struct type *type, int gcc_p)
+/* Function: m68k_register_name
+ Returns the name of the standard m68k register regnum. */
+
+static const char *
+m68k_register_name (struct gdbarch *gdbarch, int regnum)
{
- bfd_putb32 (fun, (unsigned char *) dummy + CALL_DUMMY_START_OFFSET + 2);
- bfd_putb32 (nargs*4, (unsigned char *) dummy + CALL_DUMMY_START_OFFSET + 8);
+ if (regnum < 0 || regnum >= ARRAY_SIZE (m68k_register_names))
+ internal_error (__FILE__, __LINE__,
+ _("m68k_register_name: illegal register number %d"),
+ regnum);
+ else if (regnum >= M68K_FP0_REGNUM && regnum <= M68K_FPI_REGNUM
+ && gdbarch_tdep (gdbarch)->fpregs_present == 0)
+ return "";
+ else
+ return m68k_register_names[regnum];
}
+\f
+/* Return nonzero if a value of type TYPE stored in register REGNUM
+ needs any special handling. */
+static int
+m68k_convert_register_p (struct gdbarch *gdbarch,
+ int regnum, struct type *type)
+{
+ if (!gdbarch_tdep (gdbarch)->fpregs_present)
+ return 0;
+ return (regnum >= M68K_FP0_REGNUM && regnum <= M68K_FP0_REGNUM + 7
+ /* We only support floating-point values. */
+ && TYPE_CODE (type) == TYPE_CODE_FLT
+ && type != register_type (gdbarch, M68K_FP0_REGNUM));
+}
-/* Push an empty stack frame, to record the current PC, etc. */
+/* Read a value of type TYPE from register REGNUM in frame FRAME, and
+ return its contents in TO. */
-void
-m68k_push_dummy_frame (void)
+static int
+m68k_register_to_value (struct frame_info *frame, int regnum,
+ struct type *type, gdb_byte *to,
+ int *optimizedp, int *unavailablep)
+{
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ gdb_byte from[M68K_MAX_REGISTER_SIZE];
+ struct type *fpreg_type = register_type (gdbarch, M68K_FP0_REGNUM);
+
+ gdb_assert (TYPE_CODE (type) == TYPE_CODE_FLT);
+
+ /* Convert to TYPE. */
+ if (!get_frame_register_bytes (frame, regnum, 0,
+ register_size (gdbarch, regnum),
+ from, optimizedp, unavailablep))
+ return 0;
+
+ target_float_convert (from, fpreg_type, to, type);
+ *optimizedp = *unavailablep = 0;
+ return 1;
+}
+
+/* Write the contents FROM of a value of type TYPE into register
+ REGNUM in frame FRAME. */
+
+static void
+m68k_value_to_register (struct frame_info *frame, int regnum,
+ struct type *type, const gdb_byte *from)
{
- register CORE_ADDR sp = read_register (SP_REGNUM);
- register int regnum;
- char raw_buffer[12];
+ gdb_byte to[M68K_MAX_REGISTER_SIZE];
+ struct type *fpreg_type = register_type (get_frame_arch (frame),
+ M68K_FP0_REGNUM);
- sp = push_word (sp, read_register (PC_REGNUM));
- sp = push_word (sp, read_register (FP_REGNUM));
- write_register (FP_REGNUM, sp);
+ /* We only support floating-point values. */
+ if (TYPE_CODE (type) != TYPE_CODE_FLT)
+ {
+ warning (_("Cannot convert non-floating-point type "
+ "to floating-point register value."));
+ return;
+ }
+
+ /* Convert from TYPE. */
+ target_float_convert (from, type, to, fpreg_type);
+ put_frame_register (frame, regnum, to);
+}
+
+\f
+/* There is a fair number of calling conventions that are in somewhat
+ wide use. The 68000/08/10 don't support an FPU, not even as a
+ coprocessor. All function return values are stored in %d0/%d1.
+ Structures are returned in a static buffer, a pointer to which is
+ returned in %d0. This means that functions returning a structure
+ are not re-entrant. To avoid this problem some systems use a
+ convention where the caller passes a pointer to a buffer in %a1
+ where the return values is to be stored. This convention is the
+ default, and is implemented in the function m68k_return_value.
+
+ The 68020/030/040/060 do support an FPU, either as a coprocessor
+ (68881/2) or built-in (68040/68060). That's why System V release 4
+ (SVR4) introduces a new calling convention specified by the SVR4
+ psABI. Integer values are returned in %d0/%d1, pointer return
+ values in %a0 and floating values in %fp0. When calling functions
+ returning a structure the caller should pass a pointer to a buffer
+ for the return value in %a0. This convention is implemented in the
+ function m68k_svr4_return_value, and by appropriately setting the
+ struct_value_regnum member of `struct gdbarch_tdep'.
+
+ GNU/Linux returns values in the same way as SVR4 does, but uses %a1
+ for passing the structure return value buffer.
+
+ GCC can also generate code where small structures are returned in
+ %d0/%d1 instead of in memory by using -freg-struct-return. This is
+ the default on NetBSD a.out, OpenBSD and GNU/Linux and several
+ embedded systems. This convention is implemented by setting the
+ struct_return member of `struct gdbarch_tdep' to reg_struct_return. */
+
+/* Read a function return value of TYPE from REGCACHE, and copy that
+ into VALBUF. */
- /* Always save the floating-point registers, whether they exist on
- this target or not. */
- for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--)
+static void
+m68k_extract_return_value (struct type *type, struct regcache *regcache,
+ gdb_byte *valbuf)
+{
+ int len = TYPE_LENGTH (type);
+ gdb_byte buf[M68K_MAX_REGISTER_SIZE];
+
+ if (len <= 4)
{
- read_register_bytes (REGISTER_BYTE (regnum), raw_buffer, 12);
- sp = push_bytes (sp, raw_buffer, 12);
+ regcache->raw_read (M68K_D0_REGNUM, buf);
+ memcpy (valbuf, buf + (4 - len), len);
}
+ else if (len <= 8)
+ {
+ regcache->raw_read (M68K_D0_REGNUM, buf);
+ memcpy (valbuf, buf + (8 - len), len - 4);
+ regcache->raw_read (M68K_D1_REGNUM, valbuf + (len - 4));
+ }
+ else
+ internal_error (__FILE__, __LINE__,
+ _("Cannot extract return value of %d bytes long."), len);
+}
- for (regnum = FP_REGNUM - 1; regnum >= 0; regnum--)
+static void
+m68k_svr4_extract_return_value (struct type *type, struct regcache *regcache,
+ gdb_byte *valbuf)
+{
+ gdb_byte buf[M68K_MAX_REGISTER_SIZE];
+ struct gdbarch *gdbarch = regcache->arch ();
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ if (tdep->float_return && TYPE_CODE (type) == TYPE_CODE_FLT)
{
- sp = push_word (sp, read_register (regnum));
+ struct type *fpreg_type = register_type (gdbarch, M68K_FP0_REGNUM);
+ regcache->raw_read (M68K_FP0_REGNUM, buf);
+ target_float_convert (buf, fpreg_type, valbuf, type);
}
- sp = push_word (sp, read_register (PS_REGNUM));
- write_register (SP_REGNUM, sp);
+ else if (TYPE_CODE (type) == TYPE_CODE_PTR && TYPE_LENGTH (type) == 4)
+ regcache->raw_read (M68K_A0_REGNUM, valbuf);
+ else
+ m68k_extract_return_value (type, regcache, valbuf);
}
-/* Discard from the stack the innermost frame,
- restoring all saved registers. */
+/* Write a function return value of TYPE from VALBUF into REGCACHE. */
-void
-m68k_pop_frame (void)
+static void
+m68k_store_return_value (struct type *type, struct regcache *regcache,
+ const gdb_byte *valbuf)
{
- register struct frame_info *frame = get_current_frame ();
- register CORE_ADDR fp;
- register int regnum;
- char raw_buffer[12];
+ int len = TYPE_LENGTH (type);
- fp = FRAME_FP (frame);
- m68k_frame_init_saved_regs (frame);
- for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--)
+ if (len <= 4)
+ regcache->raw_write_part (M68K_D0_REGNUM, 4 - len, len, valbuf);
+ else if (len <= 8)
{
- if (frame->saved_regs[regnum])
- {
- read_memory (frame->saved_regs[regnum], raw_buffer, 12);
- write_register_bytes (REGISTER_BYTE (regnum), raw_buffer, 12);
- }
+ regcache->raw_write_part (M68K_D0_REGNUM, 8 - len, len - 4, valbuf);
+ regcache->raw_write (M68K_D1_REGNUM, valbuf + (len - 4));
}
- for (regnum = FP_REGNUM - 1; regnum >= 0; regnum--)
+ else
+ internal_error (__FILE__, __LINE__,
+ _("Cannot store return value of %d bytes long."), len);
+}
+
+static void
+m68k_svr4_store_return_value (struct type *type, struct regcache *regcache,
+ const gdb_byte *valbuf)
+{
+ struct gdbarch *gdbarch = regcache->arch ();
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ if (tdep->float_return && TYPE_CODE (type) == TYPE_CODE_FLT)
{
- if (frame->saved_regs[regnum])
- {
- write_register (regnum, read_memory_integer (frame->saved_regs[regnum], 4));
- }
+ struct type *fpreg_type = register_type (gdbarch, M68K_FP0_REGNUM);
+ gdb_byte buf[M68K_MAX_REGISTER_SIZE];
+ target_float_convert (valbuf, type, buf, fpreg_type);
+ regcache->raw_write (M68K_FP0_REGNUM, buf);
}
- if (frame->saved_regs[PS_REGNUM])
+ else if (TYPE_CODE (type) == TYPE_CODE_PTR && TYPE_LENGTH (type) == 4)
{
- write_register (PS_REGNUM,
- read_memory_integer (frame->saved_regs[PS_REGNUM], 4));
+ regcache->raw_write (M68K_A0_REGNUM, valbuf);
+ regcache->raw_write (M68K_D0_REGNUM, valbuf);
}
- write_register (FP_REGNUM, read_memory_integer (fp, 4));
- write_register (PC_REGNUM, read_memory_integer (fp + 4, 4));
- write_register (SP_REGNUM, fp + 8);
- flush_cached_frames ();
+ else
+ m68k_store_return_value (type, regcache, valbuf);
}
-\f
-/* Given an ip value corresponding to the start of a function,
- return the ip of the first instruction after the function
- prologue. This is the generic m68k support. Machines which
- require something different can override the SKIP_PROLOGUE
- macro to point elsewhere.
+/* Return non-zero if TYPE, which is assumed to be a structure, union or
+ complex type, should be returned in registers for architecture
+ GDBARCH. */
- Some instructions which typically may appear in a function
- prologue include:
+static int
+m68k_reg_struct_return_p (struct gdbarch *gdbarch, struct type *type)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ enum type_code code = TYPE_CODE (type);
+ int len = TYPE_LENGTH (type);
- A link instruction, word form:
+ gdb_assert (code == TYPE_CODE_STRUCT || code == TYPE_CODE_UNION
+ || code == TYPE_CODE_COMPLEX);
- link.w %a6,&0 4e56 XXXX
+ if (tdep->struct_return == pcc_struct_return)
+ return 0;
- A link instruction, long form:
+ return (len == 1 || len == 2 || len == 4 || len == 8);
+}
- link.l %fp,&F%1 480e XXXX XXXX
+/* Determine, for architecture GDBARCH, how a return value of TYPE
+ should be returned. If it is supposed to be returned in registers,
+ and READBUF is non-zero, read the appropriate value from REGCACHE,
+ and copy it into READBUF. If WRITEBUF is non-zero, write the value
+ from WRITEBUF into REGCACHE. */
- A movm instruction to preserve integer regs:
+static enum return_value_convention
+m68k_return_value (struct gdbarch *gdbarch, struct value *function,
+ struct type *type, struct regcache *regcache,
+ gdb_byte *readbuf, const gdb_byte *writebuf)
+{
+ enum type_code code = TYPE_CODE (type);
- movm.l &M%1,(4,%sp) 48ef XXXX XXXX
+ /* GCC returns a `long double' in memory too. */
+ if (((code == TYPE_CODE_STRUCT || code == TYPE_CODE_UNION
+ || code == TYPE_CODE_COMPLEX)
+ && !m68k_reg_struct_return_p (gdbarch, type))
+ || (code == TYPE_CODE_FLT && TYPE_LENGTH (type) == 12))
+ {
+ /* The default on m68k is to return structures in static memory.
+ Consequently a function must return the address where we can
+ find the return value. */
- A fmovm instruction to preserve float regs:
+ if (readbuf)
+ {
+ ULONGEST addr;
- fmovm &FPM%1,(FPO%1,%sp) f237 XXXX XXXX XXXX XXXX
+ regcache_raw_read_unsigned (regcache, M68K_D0_REGNUM, &addr);
+ read_memory (addr, readbuf, TYPE_LENGTH (type));
+ }
- Some profiling setup code (FIXME, not recognized yet):
+ return RETURN_VALUE_ABI_RETURNS_ADDRESS;
+ }
- lea.l (.L3,%pc),%a1 43fb XXXX XXXX XXXX
- bsr _mcount 61ff XXXX XXXX
+ if (readbuf)
+ m68k_extract_return_value (type, regcache, readbuf);
+ if (writebuf)
+ m68k_store_return_value (type, regcache, writebuf);
- */
+ return RETURN_VALUE_REGISTER_CONVENTION;
+}
-CORE_ADDR
-m68k_skip_prologue (CORE_ADDR ip)
+static enum return_value_convention
+m68k_svr4_return_value (struct gdbarch *gdbarch, struct value *function,
+ struct type *type, struct regcache *regcache,
+ gdb_byte *readbuf, const gdb_byte *writebuf)
{
- register CORE_ADDR limit;
- struct symtab_and_line sal;
- register int op;
+ enum type_code code = TYPE_CODE (type);
- /* Find out if there is a known limit for the extent of the prologue.
- If so, ensure we don't go past it. If not, assume "infinity". */
+ if ((code == TYPE_CODE_STRUCT || code == TYPE_CODE_UNION
+ || code == TYPE_CODE_COMPLEX)
+ && !m68k_reg_struct_return_p (gdbarch, type))
+ {
+ /* The System V ABI says that:
- sal = find_pc_line (ip, 0);
- limit = (sal.end) ? sal.end : (CORE_ADDR) ~0;
+ "A function returning a structure or union also sets %a0 to
+ the value it finds in %a0. Thus when the caller receives
+ control again, the address of the returned object resides in
+ register %a0."
- while (ip < limit)
+ So the ABI guarantees that we can always find the return
+ value just after the function has returned. */
+
+ if (readbuf)
+ {
+ ULONGEST addr;
+
+ regcache_raw_read_unsigned (regcache, M68K_A0_REGNUM, &addr);
+ read_memory (addr, readbuf, TYPE_LENGTH (type));
+ }
+
+ return RETURN_VALUE_ABI_RETURNS_ADDRESS;
+ }
+
+ /* This special case is for structures consisting of a single
+ `float' or `double' member. These structures are returned in
+ %fp0. For these structures, we call ourselves recursively,
+ changing TYPE into the type of the first member of the structure.
+ Since that should work for all structures that have only one
+ member, we don't bother to check the member's type here. */
+ if (code == TYPE_CODE_STRUCT && TYPE_NFIELDS (type) == 1)
{
- op = read_memory_integer (ip, 2);
- op &= 0xFFFF;
+ type = check_typedef (TYPE_FIELD_TYPE (type, 0));
+ return m68k_svr4_return_value (gdbarch, function, type, regcache,
+ readbuf, writebuf);
+ }
- if (op == P_LINKW_FP)
- ip += 4; /* Skip link.w */
- else if (op == P_PEA_FP)
- ip += 2; /* Skip pea %fp */
- else if (op == P_MOVL_SP_FP)
- ip += 2; /* Skip move.l %sp, %fp */
- else if (op == P_LINKL_FP)
- ip += 6; /* Skip link.l */
- else if (op == P_MOVML)
- ip += 6; /* Skip movm.l */
- else if (op == P_FMOVM)
- ip += 10; /* Skip fmovm */
+ if (readbuf)
+ m68k_svr4_extract_return_value (type, regcache, readbuf);
+ if (writebuf)
+ m68k_svr4_store_return_value (type, regcache, writebuf);
+
+ return RETURN_VALUE_REGISTER_CONVENTION;
+}
+\f
+
+/* Always align the frame to a 4-byte boundary. This is required on
+ coldfire and harmless on the rest. */
+
+static CORE_ADDR
+m68k_frame_align (struct gdbarch *gdbarch, CORE_ADDR sp)
+{
+ /* Align the stack to four bytes. */
+ return sp & ~3;
+}
+
+static CORE_ADDR
+m68k_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
+ struct regcache *regcache, CORE_ADDR bp_addr, int nargs,
+ struct value **args, CORE_ADDR sp,
+ function_call_return_method return_method,
+ CORE_ADDR struct_addr)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ gdb_byte buf[4];
+ int i;
+
+ /* Push arguments in reverse order. */
+ for (i = nargs - 1; i >= 0; i--)
+ {
+ struct type *value_type = value_enclosing_type (args[i]);
+ int len = TYPE_LENGTH (value_type);
+ int container_len = (len + 3) & ~3;
+ int offset;
+
+ /* Non-scalars bigger than 4 bytes are left aligned, others are
+ right aligned. */
+ if ((TYPE_CODE (value_type) == TYPE_CODE_STRUCT
+ || TYPE_CODE (value_type) == TYPE_CODE_UNION
+ || TYPE_CODE (value_type) == TYPE_CODE_ARRAY)
+ && len > 4)
+ offset = 0;
else
- break; /* Found unknown code, bail out. */
+ offset = container_len - len;
+ sp -= container_len;
+ write_memory (sp + offset, value_contents_all (args[i]), len);
+ }
+
+ /* Store struct value address. */
+ if (return_method == return_method_struct)
+ {
+ store_unsigned_integer (buf, 4, byte_order, struct_addr);
+ regcache->cooked_write (tdep->struct_value_regnum, buf);
}
- return (ip);
+
+ /* Store return address. */
+ sp -= 4;
+ store_unsigned_integer (buf, 4, byte_order, bp_addr);
+ write_memory (sp, buf, 4);
+
+ /* Finally, update the stack pointer... */
+ store_unsigned_integer (buf, 4, byte_order, sp);
+ regcache->cooked_write (M68K_SP_REGNUM, buf);
+
+ /* ...and fake a frame pointer. */
+ regcache->cooked_write (M68K_FP_REGNUM, buf);
+
+ /* DWARF2/GCC uses the stack address *before* the function call as a
+ frame's CFA. */
+ return sp + 8;
}
-/* Store the addresses of the saved registers of the frame described by
- FRAME_INFO in its saved_regs field.
- This includes special registers such as pc and fp saved in special
- ways in the stack frame. sp is even more special:
- the address we return for it IS the sp for the next frame. */
+/* Convert a dwarf or dwarf2 regnumber to a GDB regnum. */
-void
-m68k_frame_init_saved_regs (struct frame_info *frame_info)
+static int
+m68k_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int num)
{
- register int regnum;
- register int regmask;
- register CORE_ADDR next_addr;
- register CORE_ADDR pc;
+ if (num < 8)
+ /* d0..7 */
+ return (num - 0) + M68K_D0_REGNUM;
+ else if (num < 16)
+ /* a0..7 */
+ return (num - 8) + M68K_A0_REGNUM;
+ else if (num < 24 && gdbarch_tdep (gdbarch)->fpregs_present)
+ /* fp0..7 */
+ return (num - 16) + M68K_FP0_REGNUM;
+ else if (num == 25)
+ /* pc */
+ return M68K_PC_REGNUM;
+ else
+ return -1;
+}
- /* First possible address for a pc in a call dummy for this frame. */
- CORE_ADDR possible_call_dummy_start =
- (frame_info)->frame - 28 - FP_REGNUM * 4 - 4 - 8 * 12;
+\f
+struct m68k_frame_cache
+{
+ /* Base address. */
+ CORE_ADDR base;
+ CORE_ADDR sp_offset;
+ CORE_ADDR pc;
- int nextinsn;
+ /* Saved registers. */
+ CORE_ADDR saved_regs[M68K_NUM_REGS];
+ CORE_ADDR saved_sp;
- if (frame_info->saved_regs)
- return;
+ /* Stack space reserved for local variables. */
+ long locals;
+};
- frame_saved_regs_zalloc (frame_info);
+/* Allocate and initialize a frame cache. */
- memset (frame_info->saved_regs, 0, SIZEOF_FRAME_SAVED_REGS);
+static struct m68k_frame_cache *
+m68k_alloc_frame_cache (void)
+{
+ struct m68k_frame_cache *cache;
+ int i;
- if ((frame_info)->pc >= possible_call_dummy_start
- && (frame_info)->pc <= (frame_info)->frame)
- {
+ cache = FRAME_OBSTACK_ZALLOC (struct m68k_frame_cache);
- /* It is a call dummy. We could just stop now, since we know
- what the call dummy saves and where. But this code proceeds
- to parse the "prologue" which is part of the call dummy.
- This is needlessly complex and confusing. FIXME. */
+ /* Base address. */
+ cache->base = 0;
+ cache->sp_offset = -4;
+ cache->pc = 0;
- next_addr = (frame_info)->frame;
- pc = possible_call_dummy_start;
- }
- else
- {
- pc = get_pc_function_start ((frame_info)->pc);
+ /* Saved registers. We initialize these to -1 since zero is a valid
+ offset (that's where %fp is supposed to be stored). */
+ for (i = 0; i < M68K_NUM_REGS; i++)
+ cache->saved_regs[i] = -1;
- nextinsn = read_memory_integer (pc, 2);
- if (P_PEA_FP == nextinsn
- && P_MOVL_SP_FP == read_memory_integer (pc + 2, 2))
- {
- /* pea %fp
- move.l %sp, %fp */
- next_addr = frame_info->frame;
- pc += 4;
- }
- else if (P_LINKL_FP == nextinsn)
- /* link.l %fp */
- /* Find the address above the saved
- regs using the amount of storage from the link instruction. */
- {
- next_addr = (frame_info)->frame + read_memory_integer (pc + 2, 4);
- pc += 6;
- }
- else if (P_LINKW_FP == nextinsn)
- /* link.w %fp */
- /* Find the address above the saved
- regs using the amount of storage from the link instruction. */
- {
- next_addr = (frame_info)->frame + read_memory_integer (pc + 2, 2);
- pc += 4;
- }
- else
- goto lose;
+ /* Frameless until proven otherwise. */
+ cache->locals = -1;
- /* If have an addal #-n, sp next, adjust next_addr. */
- if ((0177777 & read_memory_integer (pc, 2)) == 0157774)
- next_addr += read_memory_integer (pc += 2, 4), pc += 4;
- }
+ 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.
+ Otherwise, return PC. */
+
+static CORE_ADDR
+m68k_analyze_frame_setup (struct gdbarch *gdbarch,
+ CORE_ADDR pc, CORE_ADDR current_pc,
+ struct m68k_frame_cache *cache)
+{
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ int op;
+
+ if (pc >= current_pc)
+ return current_pc;
+
+ op = read_memory_unsigned_integer (pc, 2, byte_order);
- for (;;)
+ if (op == P_LINKW_FP || op == P_LINKL_FP || op == P_PEA_FP)
{
- nextinsn = 0xffff & read_memory_integer (pc, 2);
- regmask = read_memory_integer (pc + 2, 2);
- /* fmovemx to -(sp) */
- if (0xf227 == nextinsn && (regmask & 0xff00) == 0xe000)
- {
- /* Regmask's low bit is for register fp7, the first pushed */
- for (regnum = FP0_REGNUM + 8; --regnum >= FP0_REGNUM; regmask >>= 1)
- if (regmask & 1)
- frame_info->saved_regs[regnum] = (next_addr -= 12);
- pc += 4;
- }
- /* fmovemx to (fp + displacement) */
- else if (0171056 == nextinsn && (regmask & 0xff00) == 0xf000)
- {
- register CORE_ADDR addr;
-
- addr = (frame_info)->frame + read_memory_integer (pc + 4, 2);
- /* Regmask's low bit is for register fp7, the first pushed */
- for (regnum = FP0_REGNUM + 8; --regnum >= FP0_REGNUM; regmask >>= 1)
- if (regmask & 1)
- {
- frame_info->saved_regs[regnum] = addr;
- addr += 12;
- }
- pc += 6;
- }
- /* moveml to (sp) */
- else if (0044327 == nextinsn)
- {
- /* Regmask's low bit is for register 0, the first written */
- for (regnum = 0; regnum < 16; regnum++, regmask >>= 1)
- if (regmask & 1)
- {
- frame_info->saved_regs[regnum] = next_addr;
- next_addr += 4;
- }
- pc += 4;
- }
- /* moveml to (fp + displacement) */
- else if (0044356 == nextinsn)
- {
- register CORE_ADDR addr;
-
- addr = (frame_info)->frame + read_memory_integer (pc + 4, 2);
- /* Regmask's low bit is for register 0, the first written */
- for (regnum = 0; regnum < 16; regnum++, regmask >>= 1)
- if (regmask & 1)
- {
- frame_info->saved_regs[regnum] = addr;
- addr += 4;
- }
- pc += 6;
- }
- /* moveml to -(sp) */
- else if (0044347 == nextinsn)
+ cache->saved_regs[M68K_FP_REGNUM] = 0;
+ cache->sp_offset += 4;
+ if (op == P_LINKW_FP)
{
- /* Regmask's low bit is for register 15, the first pushed */
- for (regnum = 16; --regnum >= 0; regmask >>= 1)
- if (regmask & 1)
- frame_info->saved_regs[regnum] = (next_addr -= 4);
- pc += 4;
+ /* link.w %fp, #-N */
+ /* link.w %fp, #0; adda.l #-N, %sp */
+ cache->locals = -read_memory_integer (pc + 2, 2, byte_order);
+
+ if (pc + 4 < current_pc && cache->locals == 0)
+ {
+ op = read_memory_unsigned_integer (pc + 4, 2, byte_order);
+ if (op == P_ADDAL_SP)
+ {
+ cache->locals = read_memory_integer (pc + 6, 4, byte_order);
+ return pc + 10;
+ }
+ }
+
+ return pc + 4;
}
- /* movl r,-(sp) */
- else if (0x2f00 == (0xfff0 & nextinsn))
+ else if (op == P_LINKL_FP)
{
- regnum = 0xf & nextinsn;
- frame_info->saved_regs[regnum] = (next_addr -= 4);
- pc += 2;
+ /* link.l %fp, #-N */
+ cache->locals = -read_memory_integer (pc + 2, 4, byte_order);
+ return pc + 6;
}
- /* fmovemx to index of sp */
- else if (0xf236 == nextinsn && (regmask & 0xff00) == 0xf000)
+ else
{
- /* Regmask's low bit is for register fp0, the first written */
- for (regnum = FP0_REGNUM + 8; --regnum >= FP0_REGNUM; regmask >>= 1)
- if (regmask & 1)
- {
- frame_info->saved_regs[regnum] = next_addr;
- next_addr += 12;
- }
- pc += 10;
+ /* pea (%fp); movea.l %sp, %fp */
+ cache->locals = 0;
+
+ if (pc + 2 < current_pc)
+ {
+ op = read_memory_unsigned_integer (pc + 2, 2, byte_order);
+
+ if (op == P_MOVEAL_SP_FP)
+ {
+ /* move.l %sp, %fp */
+ return pc + 4;
+ }
+ }
+
+ return pc + 2;
}
- /* clrw -(sp); movw ccr,-(sp) */
- else if (0x4267 == nextinsn && 0x42e7 == regmask)
+ }
+ 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)
{
- frame_info->saved_regs[PS_REGNUM] = (next_addr -= 4);
- pc += 4;
+ op = read_memory_unsigned_integer (pc + 2, 2, byte_order);
+ if ((op & 0170777) == P_SUBQW_SP || (op & 0170777) == P_SUBQL_SP)
+ {
+ cache->locals += (op & 07000) == 0 ? 8 : (op & 07000) >> 9;
+ return pc + 4;
+ }
}
- else
- break;
+ return pc + 2;
}
-lose:;
- frame_info->saved_regs[SP_REGNUM] = (frame_info)->frame + 8;
- frame_info->saved_regs[FP_REGNUM] = (frame_info)->frame;
- frame_info->saved_regs[PC_REGNUM] = (frame_info)->frame + 4;
-#ifdef SIG_SP_FP_OFFSET
- /* Adjust saved SP_REGNUM for fake _sigtramp frames. */
- if (frame_info->signal_handler_caller && frame_info->next)
- frame_info->saved_regs[SP_REGNUM] =
- frame_info->next->frame + SIG_SP_FP_OFFSET;
-#endif
+ 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, byte_order);
+ return pc + 4;
+ }
+ else if (op == P_ADDAL_SP)
+ {
+ /* adda.l #-N,%sp */
+ cache->locals = -read_memory_integer (pc + 2, 4, byte_order);
+ 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. */
-#ifdef USE_PROC_FS /* Target dependent support for /proc */
+static CORE_ADDR
+m68k_analyze_register_saves (struct gdbarch *gdbarch, CORE_ADDR pc,
+ CORE_ADDR current_pc,
+ struct m68k_frame_cache *cache)
+{
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
-#include <sys/procfs.h>
+ if (cache->locals >= 0)
+ {
+ CORE_ADDR offset;
+ int op;
+ int i, mask, regno;
-/* Prototypes for supply_gregset etc. */
-#include "gregset.h"
+ offset = -4 - cache->locals;
+ while (pc < current_pc)
+ {
+ op = read_memory_unsigned_integer (pc, 2, byte_order);
+ if (op == P_FMOVEMX_SP
+ && gdbarch_tdep (gdbarch)->fpregs_present)
+ {
+ /* fmovem.x REGS,-(%sp) */
+ op = read_memory_unsigned_integer (pc + 2, 2, byte_order);
+ 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 & 0177760) == P_MOVEL_SP)
+ {
+ /* move.l %R,-(%sp) */
+ regno = op & 017;
+ 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, byte_order);
+ for (i = 0; i < 16; i++, mask >>= 1)
+ {
+ if (mask & 1)
+ {
+ cache->saved_regs[15 - i] = offset;
+ offset -= 4;
+ }
+ }
+ pc += 4;
+ }
+ else
+ break;
+ }
+ }
-/* 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.
+ return pc;
+}
- 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];
+/* 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.
- #define R_D0 0
- ...
- #define R_PS 17
+ We handle all cases that can be generated by gcc.
- and the floating point set by:
+ For allocating a stack frame:
- typedef struct fpregset {
- int f_pcr;
- int f_psr;
- int f_fpiaddr;
- int f_fpregs[8][3]; (8 regs, 96 bits each)
- } fpregset_t;
+ 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
- These routines provide the packing and unpacking of gregset_t and
- fpregset_t formatted data.
+ For saving registers:
- */
+ fmovem.x REGS,-(%sp)
+ move.l R1,-(%sp)
+ move.l R1,-(%sp); move.l R2,-(%sp)
+ movem.l REGS,-(%sp)
-/* Atari SVR4 has R_SR but not R_PS */
+ For setting up the PIC register:
-#if !defined (R_PS) && defined (R_SR)
-#define R_PS R_SR
-#endif
+ lea (%pc,N),%a5
-/* 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)
+static CORE_ADDR
+m68k_analyze_prologue (struct gdbarch *gdbarch, CORE_ADDR pc,
+ CORE_ADDR current_pc, struct m68k_frame_cache *cache)
{
- register int regi;
- register greg_t *regp = (greg_t *) gregsetp;
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ unsigned int op;
+
+ pc = m68k_analyze_frame_setup (gdbarch, pc, current_pc, cache);
+ pc = m68k_analyze_register_saves (gdbarch, pc, current_pc, cache);
+ if (pc >= current_pc)
+ return current_pc;
- for (regi = 0; regi < R_PC; regi++)
+ /* Check for GOT setup. */
+ op = read_memory_unsigned_integer (pc, 4, byte_order);
+ if (op == P_LEA_PC_A5)
{
- supply_register (regi, (char *) (regp + regi));
+ /* lea (%pc,N),%a5 */
+ return pc + 8;
}
- supply_register (PS_REGNUM, (char *) (regp + R_PS));
- supply_register (PC_REGNUM, (char *) (regp + R_PC));
+
+ return pc;
}
-void
-fill_gregset (gregset_t *gregsetp, int regno)
+/* Return PC of first real instruction. */
+
+static CORE_ADDR
+m68k_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc)
{
- register int regi;
- register greg_t *regp = (greg_t *) gregsetp;
+ struct m68k_frame_cache cache;
+ CORE_ADDR pc;
- for (regi = 0; regi < R_PC; regi++)
- {
- if ((regno == -1) || (regno == regi))
- {
- *(regp + regi) = *(int *) ®isters[REGISTER_BYTE (regi)];
- }
- }
- if ((regno == -1) || (regno == PS_REGNUM))
- {
- *(regp + R_PS) = *(int *) ®isters[REGISTER_BYTE (PS_REGNUM)];
- }
- if ((regno == -1) || (regno == PC_REGNUM))
- {
- *(regp + R_PC) = *(int *) ®isters[REGISTER_BYTE (PC_REGNUM)];
- }
+ cache.locals = -1;
+ pc = m68k_analyze_prologue (gdbarch, start_pc, (CORE_ADDR) -1, &cache);
+ if (cache.locals < 0)
+ return start_pc;
+ return pc;
}
-#if defined (FP0_REGNUM)
+static CORE_ADDR
+m68k_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
+{
+ gdb_byte buf[8];
-/* 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. */
+ frame_unwind_register (next_frame, gdbarch_pc_regnum (gdbarch), buf);
+ return extract_typed_address (buf, builtin_type (gdbarch)->builtin_func_ptr);
+}
+\f
+/* Normal frames. */
-void
-supply_fpregset (fpregset_t *fpregsetp)
+static struct m68k_frame_cache *
+m68k_frame_cache (struct frame_info *this_frame, void **this_cache)
{
- register int regi;
- char *from;
-
- for (regi = FP0_REGNUM; regi < FPC_REGNUM; regi++)
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ struct m68k_frame_cache *cache;
+ gdb_byte buf[4];
+ int i;
+
+ if (*this_cache)
+ return (struct m68k_frame_cache *) *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. */
+
+ get_frame_register (this_frame, M68K_FP_REGNUM, buf);
+ cache->base = extract_unsigned_integer (buf, 4, byte_order);
+ if (cache->base == 0)
+ return cache;
+
+ /* For normal frames, %pc is stored at 4(%fp). */
+ cache->saved_regs[M68K_PC_REGNUM] = 4;
+
+ cache->pc = get_frame_func (this_frame);
+ if (cache->pc != 0)
+ m68k_analyze_prologue (get_frame_arch (this_frame), cache->pc,
+ get_frame_pc (this_frame), cache);
+
+ if (cache->locals < 0)
{
- from = (char *) &(fpregsetp->f_fpregs[regi - FP0_REGNUM][0]);
- supply_register (regi, from);
+ /* 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. */
+
+ get_frame_register (this_frame, M68K_SP_REGNUM, buf);
+ cache->base = extract_unsigned_integer (buf, 4, byte_order)
+ + cache->sp_offset;
}
- supply_register (FPC_REGNUM, (char *) &(fpregsetp->f_pcr));
- supply_register (FPS_REGNUM, (char *) &(fpregsetp->f_psr));
- supply_register (FPI_REGNUM, (char *) &(fpregsetp->f_fpiaddr));
+
+ /* 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;
}
-/* 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. */
+static void
+m68k_frame_this_id (struct frame_info *this_frame, void **this_cache,
+ struct frame_id *this_id)
+{
+ struct m68k_frame_cache *cache = m68k_frame_cache (this_frame, this_cache);
-void
-fill_fpregset (fpregset_t *fpregsetp, int regno)
+ /* 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 struct value *
+m68k_frame_prev_register (struct frame_info *this_frame, void **this_cache,
+ int regnum)
{
- int regi;
- char *to;
- char *from;
+ struct m68k_frame_cache *cache = m68k_frame_cache (this_frame, this_cache);
- for (regi = FP0_REGNUM; regi < FPC_REGNUM; regi++)
- {
- if ((regno == -1) || (regno == regi))
- {
- from = (char *) ®isters[REGISTER_BYTE (regi)];
- to = (char *) &(fpregsetp->f_fpregs[regi - FP0_REGNUM][0]);
- memcpy (to, from, REGISTER_RAW_SIZE (regi));
- }
- }
- if ((regno == -1) || (regno == FPC_REGNUM))
- {
- fpregsetp->f_pcr = *(int *) ®isters[REGISTER_BYTE (FPC_REGNUM)];
- }
- if ((regno == -1) || (regno == FPS_REGNUM))
- {
- fpregsetp->f_psr = *(int *) ®isters[REGISTER_BYTE (FPS_REGNUM)];
- }
- if ((regno == -1) || (regno == FPI_REGNUM))
- {
- fpregsetp->f_fpiaddr = *(int *) ®isters[REGISTER_BYTE (FPI_REGNUM)];
- }
+ gdb_assert (regnum >= 0);
+
+ if (regnum == M68K_SP_REGNUM && cache->saved_sp)
+ return frame_unwind_got_constant (this_frame, regnum, cache->saved_sp);
+
+ if (regnum < M68K_NUM_REGS && cache->saved_regs[regnum] != -1)
+ return frame_unwind_got_memory (this_frame, regnum,
+ cache->saved_regs[regnum]);
+
+ return frame_unwind_got_register (this_frame, regnum, regnum);
+}
+
+static const struct frame_unwind m68k_frame_unwind =
+{
+ NORMAL_FRAME,
+ default_frame_unwind_stop_reason,
+ m68k_frame_this_id,
+ m68k_frame_prev_register,
+ NULL,
+ default_frame_sniffer
+};
+\f
+static CORE_ADDR
+m68k_frame_base_address (struct frame_info *this_frame, void **this_cache)
+{
+ struct m68k_frame_cache *cache = m68k_frame_cache (this_frame, this_cache);
+
+ return cache->base;
}
-#endif /* defined (FP0_REGNUM) */
+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_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
+{
+ CORE_ADDR fp;
+
+ fp = get_frame_register_unsigned (this_frame, M68K_FP_REGNUM);
-#endif /* USE_PROC_FS */
+ /* See the end of m68k_push_dummy_call. */
+ return frame_id_build (fp + 8, get_frame_pc (this_frame));
+}
+\f
/* 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. */
-
-/* NOTE: cagney/2000-11-08: For this function to be fully multi-arched
- the macro's JB_PC and JB_ELEMENT_SIZE would need to be moved into
- the ``struct gdbarch_tdep'' object and then set on a target ISA/ABI
- dependant basis. */
+ This routine returns true on success. */
-int
-m68k_get_longjmp_target (CORE_ADDR *pc)
+static int
+m68k_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc)
{
-#if defined (JB_PC) && defined (JB_ELEMENT_SIZE)
- char *buf;
+ gdb_byte *buf;
CORE_ADDR sp, jb_addr;
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- buf = alloca (TARGET_PTR_BIT / TARGET_CHAR_BIT);
- sp = read_register (SP_REGNUM);
+ if (tdep->jb_pc < 0)
+ {
+ internal_error (__FILE__, __LINE__,
+ _("m68k_get_longjmp_target: not implemented"));
+ return 0;
+ }
- if (target_read_memory (sp + SP_ARG0, /* Offset of first arg on stack */
- buf, TARGET_PTR_BIT / TARGET_CHAR_BIT))
+ buf = (gdb_byte *) alloca (gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT);
+ sp = get_frame_register_unsigned (frame, gdbarch_sp_regnum (gdbarch));
+
+ if (target_read_memory (sp + SP_ARG0, /* Offset of first arg on stack. */
+ buf, gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT))
return 0;
- jb_addr = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
+ jb_addr = extract_unsigned_integer (buf, gdbarch_ptr_bit (gdbarch)
+ / TARGET_CHAR_BIT, byte_order);
- if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf,
- TARGET_PTR_BIT / TARGET_CHAR_BIT))
+ if (target_read_memory (jb_addr + tdep->jb_pc * tdep->jb_elt_size, buf,
+ gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT),
+ byte_order)
return 0;
- *pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
-
+ *pc = extract_unsigned_integer (buf, gdbarch_ptr_bit (gdbarch)
+ / TARGET_CHAR_BIT, byte_order);
return 1;
-#else
- internal_error (__FILE__, __LINE__,
- "m68k_get_longjmp_target: not implemented");
+}
+\f
+
+/* This is the implementation of gdbarch method
+ return_in_first_hidden_param_p. */
+
+static int
+m68k_return_in_first_hidden_param_p (struct gdbarch *gdbarch,
+ struct type *type)
+{
return 0;
-#endif
}
-/* 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. */
+/* System V Release 4 (SVR4). */
-CORE_ADDR
-m68k_saved_pc_after_call (struct frame_info *frame)
+void
+m68k_svr4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
-#ifdef SYSCALL_TRAP
- int op;
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
- op = read_memory_integer (frame->pc - SYSCALL_TRAP_OFFSET, 2);
+ /* SVR4 uses a different calling convention. */
+ set_gdbarch_return_value (gdbarch, m68k_svr4_return_value);
- if (op == SYSCALL_TRAP)
- return read_memory_integer (read_register (SP_REGNUM) + 4, 4);
- else
-#endif /* SYSCALL_TRAP */
- return read_memory_integer (read_register (SP_REGNUM), 4);
+ /* SVR4 uses %a0 instead of %a1. */
+ tdep->struct_value_regnum = M68K_A0_REGNUM;
}
+\f
/* Function: m68k_gdbarch_init
Initializer function for the m68k gdbarch vector.
- Called by gdbarch. Sets up the gdbarch vector(s) for this target. */
+ 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)
{
- static LONGEST call_dummy_words[7] = {0xf227e0ff, 0x48e7fffc, 0x426742e7,
- 0x4eb93232, 0x3232dffc, 0x69696969,
- (0x4e404e71 | (BPT_VECTOR << 16))};
struct gdbarch_tdep *tdep = NULL;
struct gdbarch *gdbarch;
+ struct gdbarch_list *best_arch;
+ struct tdesc_arch_data *tdesc_data = NULL;
+ int i;
+ enum m68k_flavour flavour = m68k_no_flavour;
+ int has_fp = 1;
+ const struct floatformat **long_double_format = floatformats_m68881_ext;
+
+ /* Check any target description for validity. */
+ if (tdesc_has_registers (info.target_desc))
+ {
+ const struct tdesc_feature *feature;
+ int valid_p;
- /* find a candidate among the list of pre-declared architectures. */
- arches = gdbarch_list_lookup_by_info (arches, &info);
- if (arches != NULL)
- return (arches->gdbarch);
+ feature = tdesc_find_feature (info.target_desc,
+ "org.gnu.gdb.m68k.core");
-#if 0
- tdep = (struct gdbarch_tdep *) xmalloc (sizeof (struct gdbarch_tdep));
-#endif
+ if (feature == NULL)
+ {
+ feature = tdesc_find_feature (info.target_desc,
+ "org.gnu.gdb.coldfire.core");
+ if (feature != NULL)
+ flavour = m68k_coldfire_flavour;
+ }
+
+ if (feature == NULL)
+ {
+ feature = tdesc_find_feature (info.target_desc,
+ "org.gnu.gdb.fido.core");
+ if (feature != NULL)
+ flavour = m68k_fido_flavour;
+ }
- gdbarch = gdbarch_alloc (&info, 0);
+ if (feature == NULL)
+ return NULL;
- set_gdbarch_frame_init_saved_regs (gdbarch, m68k_frame_init_saved_regs);
-
- set_gdbarch_use_generic_dummy_frames (gdbarch, 0);
- set_gdbarch_call_dummy_location (gdbarch, ON_STACK);
- set_gdbarch_call_dummy_breakpoint_offset_p (gdbarch, 1);
- set_gdbarch_call_dummy_breakpoint_offset (gdbarch, 24);
- set_gdbarch_pc_in_call_dummy (gdbarch, pc_in_call_dummy_on_stack);
- set_gdbarch_call_dummy_p (gdbarch, 1);
- set_gdbarch_call_dummy_stack_adjust_p (gdbarch, 0);
- set_gdbarch_call_dummy_length (gdbarch, 28);
- set_gdbarch_call_dummy_start_offset (gdbarch, 12);
+ tdesc_data = tdesc_data_alloc ();
+
+ valid_p = 1;
+ for (i = 0; i <= M68K_PC_REGNUM; i++)
+ valid_p &= tdesc_numbered_register (feature, tdesc_data, i,
+ m68k_register_names[i]);
+
+ if (!valid_p)
+ {
+ tdesc_data_cleanup (tdesc_data);
+ return NULL;
+ }
+
+ feature = tdesc_find_feature (info.target_desc,
+ "org.gnu.gdb.coldfire.fp");
+ if (feature != NULL)
+ {
+ valid_p = 1;
+ for (i = M68K_FP0_REGNUM; i <= M68K_FPI_REGNUM; i++)
+ valid_p &= tdesc_numbered_register (feature, tdesc_data, i,
+ m68k_register_names[i]);
+ if (!valid_p)
+ {
+ tdesc_data_cleanup (tdesc_data);
+ return NULL;
+ }
+ }
+ else
+ has_fp = 0;
+ }
+
+ /* The mechanism for returning floating values from function
+ and the type of long double depend on whether we're
+ on ColdFire or standard m68k. */
+
+ if (info.bfd_arch_info && info.bfd_arch_info->mach != 0)
+ {
+ const bfd_arch_info_type *coldfire_arch =
+ bfd_lookup_arch (bfd_arch_m68k, bfd_mach_mcf_isa_a_nodiv);
+
+ if (coldfire_arch
+ && ((*info.bfd_arch_info->compatible)
+ (info.bfd_arch_info, coldfire_arch)))
+ flavour = m68k_coldfire_flavour;
+ }
- set_gdbarch_call_dummy_words (gdbarch, call_dummy_words);
- set_gdbarch_sizeof_call_dummy_words (gdbarch, sizeof (call_dummy_words));
- set_gdbarch_call_dummy_stack_adjust_p (gdbarch, 0);
- set_gdbarch_fix_call_dummy (gdbarch, m68k_fix_call_dummy);
- set_gdbarch_push_dummy_frame (gdbarch, m68k_push_dummy_frame);
- set_gdbarch_pop_frame (gdbarch, m68k_pop_frame);
-
+ /* If there is already a candidate, use it. */
+ for (best_arch = gdbarch_list_lookup_by_info (arches, &info);
+ best_arch != NULL;
+ best_arch = gdbarch_list_lookup_by_info (best_arch->next, &info))
+ {
+ if (flavour != gdbarch_tdep (best_arch->gdbarch)->flavour)
+ continue;
+
+ if (has_fp != gdbarch_tdep (best_arch->gdbarch)->fpregs_present)
+ continue;
+
+ break;
+ }
+
+ if (best_arch != NULL)
+ {
+ if (tdesc_data != NULL)
+ tdesc_data_cleanup (tdesc_data);
+ return best_arch->gdbarch;
+ }
+
+ tdep = XCNEW (struct gdbarch_tdep);
+ gdbarch = gdbarch_alloc (&info, tdep);
+ tdep->fpregs_present = has_fp;
+ tdep->flavour = flavour;
+
+ if (flavour == m68k_coldfire_flavour || flavour == m68k_fido_flavour)
+ long_double_format = floatformats_ieee_double;
+ set_gdbarch_long_double_format (gdbarch, long_double_format);
+ set_gdbarch_long_double_bit (gdbarch, long_double_format[0]->totalsize);
+
+ set_gdbarch_skip_prologue (gdbarch, m68k_skip_prologue);
+ set_gdbarch_breakpoint_kind_from_pc (gdbarch, m68k_breakpoint::kind_from_pc);
+ set_gdbarch_sw_breakpoint_from_kind (gdbarch, m68k_breakpoint::bp_from_kind);
+
+ /* Stack grows down. */
+ set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
+ set_gdbarch_frame_align (gdbarch, m68k_frame_align);
+
+ set_gdbarch_believe_pcc_promotion (gdbarch, 1);
+ if (flavour == m68k_coldfire_flavour || flavour == m68k_fido_flavour)
+ set_gdbarch_decr_pc_after_break (gdbarch, 2);
+
+ set_gdbarch_frame_args_skip (gdbarch, 8);
+ set_gdbarch_dwarf2_reg_to_regnum (gdbarch, m68k_dwarf_reg_to_regnum);
+
+ set_gdbarch_register_type (gdbarch, m68k_register_type);
+ set_gdbarch_register_name (gdbarch, m68k_register_name);
+ set_gdbarch_num_regs (gdbarch, M68K_NUM_REGS);
+ 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_convert_register_p (gdbarch, m68k_convert_register_p);
+ set_gdbarch_register_to_value (gdbarch, m68k_register_to_value);
+ set_gdbarch_value_to_register (gdbarch, m68k_value_to_register);
+
+ if (has_fp)
+ set_gdbarch_fp0_regnum (gdbarch, M68K_FP0_REGNUM);
+
+ /* Try to figure out if the arch uses floating registers to return
+ floating point values from functions. */
+ if (has_fp)
+ {
+ /* On ColdFire, floating point values are returned in D0. */
+ if (flavour == m68k_coldfire_flavour)
+ tdep->float_return = 0;
+ else
+ tdep->float_return = 1;
+ }
+ else
+ {
+ /* No floating registers, so can't use them for returning values. */
+ tdep->float_return = 0;
+ }
+
+ /* Function call & return. */
+ set_gdbarch_push_dummy_call (gdbarch, m68k_push_dummy_call);
+ set_gdbarch_return_value (gdbarch, m68k_return_value);
+ set_gdbarch_return_in_first_hidden_param_p (gdbarch,
+ m68k_return_in_first_hidden_param_p);
+
+#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->struct_value_regnum = M68K_A1_REGNUM;
+ tdep->struct_return = reg_struct_return;
+
+ /* Frame unwinder. */
+ set_gdbarch_dummy_id (gdbarch, m68k_dummy_id);
+ set_gdbarch_unwind_pc (gdbarch, m68k_unwind_pc);
+
+ /* Hook in the DWARF CFI frame unwinder. */
+ dwarf2_append_unwinders (gdbarch);
+
+ 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_unwinder (gdbarch, &m68k_frame_unwind);
+
+ if (tdesc_data)
+ tdesc_use_registers (gdbarch, info.target_desc, tdesc_data);
+
return gdbarch;
}
static void
-m68k_dump_tdep (struct gdbarch *current_gdbarch, struct ui_file *file)
+m68k_dump_tdep (struct gdbarch *gdbarch, struct ui_file *file)
{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ if (tdep == NULL)
+ return;
}
void
_initialize_m68k_tdep (void)
{
gdbarch_register (bfd_arch_m68k, m68k_gdbarch_init, m68k_dump_tdep);
- tm_print_insn = print_insn_m68k;
}
projects / deliverable / binutils-gdb.git / blobdiff