8665f3dcfa
* m32r-tdep.c: Improved frame_chain and fn prologue analysis.
* configure.tgt: Add entry for m32r target.
* monitor.h: Add a flag to tell monitor_store_register to use
(val, regno) instead of (regno, val).
* monitor.c: Make monitor_store_register honor the above flag.
Make monitor_exp ignore DC1/DC3 for m32r.
Increase buf size in monitor_dump_regs.
414 lines
11 KiB
C
414 lines
11 KiB
C
/* Target-dependent code for the Mitsubishi m32r for GDB, the GNU debugger.
|
||
Copyright 1996, 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
|
||
(at your option) any later version.
|
||
|
||
This program is distributed in the hope that it will be useful,
|
||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
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. */
|
||
|
||
#include "defs.h"
|
||
#include "frame.h"
|
||
#include "inferior.h"
|
||
#include "obstack.h"
|
||
#include "target.h"
|
||
#include "value.h"
|
||
#include "bfd.h"
|
||
#include "gdb_string.h"
|
||
#include "gdbcore.h"
|
||
#include "symfile.h"
|
||
|
||
struct dummy_frame
|
||
{
|
||
struct dummy_frame *next;
|
||
|
||
CORE_ADDR fp;
|
||
CORE_ADDR sp;
|
||
CORE_ADDR rp;
|
||
CORE_ADDR pc;
|
||
};
|
||
|
||
void
|
||
m32r_frame_find_saved_regs PARAMS ((struct frame_info *fi,
|
||
struct frame_saved_regs *regaddr))
|
||
{
|
||
*regaddr = fi->fsr;
|
||
}
|
||
|
||
static struct dummy_frame *dummy_frame_stack = NULL;
|
||
|
||
/* Find end of function prologue */
|
||
|
||
CORE_ADDR
|
||
m32r_skip_prologue (pc)
|
||
CORE_ADDR pc;
|
||
{
|
||
CORE_ADDR func_addr, func_end;
|
||
struct symtab_and_line sal;
|
||
|
||
/* See what the symbol table says */
|
||
|
||
if (find_pc_partial_function (pc, NULL, &func_addr, &func_end))
|
||
{
|
||
sal = find_pc_line (func_addr, 0);
|
||
|
||
if (sal.line != 0 && sal.end < func_end)
|
||
return sal.end;
|
||
else
|
||
/* Either there's no line info, or the line after the prologue is after
|
||
the end of the function. In this case, there probably isn't a
|
||
prologue. */
|
||
return pc;
|
||
}
|
||
|
||
/* We can't find the start of this function, so there's nothing we can do. */
|
||
return pc;
|
||
}
|
||
|
||
/* This function decodes the target function prologue to determine
|
||
1) the size of the stack frame, and 2) which registers are saved on it.
|
||
It saves the offsets of saved regs in the frame_saved_regs argument,
|
||
and returns the frame size.
|
||
*/
|
||
|
||
static unsigned long
|
||
m32r_scan_prologue (fi, fsr)
|
||
struct frame_info *fi;
|
||
struct frame_saved_regs *fsr;
|
||
{
|
||
struct symtab_and_line sal;
|
||
CORE_ADDR prologue_start, prologue_end, current_pc;
|
||
unsigned long framesize;
|
||
|
||
/* this code essentially duplicates skip_prologue,
|
||
but we need the start address below. */
|
||
|
||
if (fsr)
|
||
memset (fsr->regs, '\000', sizeof fsr->regs);
|
||
|
||
if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end))
|
||
{
|
||
sal = find_pc_line (prologue_start, 0);
|
||
|
||
if (sal.line == 0) /* no line info, use current PC */
|
||
if (prologue_start != entry_point_address ())
|
||
prologue_end = fi->pc;
|
||
else
|
||
return 0; /* _start has no frame or prologue */
|
||
else if (sal.end < prologue_end) /* next line begins after fn end */
|
||
prologue_end = sal.end; /* (probably means no prologue) */
|
||
}
|
||
else
|
||
prologue_end = prologue_start + 48; /* We're in the boondocks: allow for */
|
||
/* 16 pushes, an add, and "mv fp,sp" */
|
||
|
||
prologue_end = min (prologue_end, fi->pc);
|
||
|
||
/* Now, search the prologue looking for instructions that setup fp, save
|
||
rp (and other regs), adjust sp and such. */
|
||
|
||
framesize = 0;
|
||
for (current_pc = prologue_start; current_pc < prologue_end; current_pc += 2)
|
||
{
|
||
int insn;
|
||
int regno;
|
||
|
||
insn = read_memory_unsigned_integer (current_pc, 2);
|
||
if (insn & 0x8000) /* Four byte instruction? */
|
||
current_pc += 2;
|
||
|
||
if ((insn & 0xf0ff) == 0x207f) { /* st reg, @-sp */
|
||
framesize += 4;
|
||
regno = ((insn >> 8) & 0xf);
|
||
if (fsr) /* save_regs offset */
|
||
fsr->regs[regno] = framesize;
|
||
}
|
||
else if ((insn >> 8) == 0x4f) /* addi sp, xx */
|
||
/* add 8 bit sign-extended offset */
|
||
framesize += -((char) (insn & 0xff));
|
||
else if (insn == 0x8faf) /* add3 sp, sp, xxxx */
|
||
/* add 16 bit sign-extended offset */
|
||
framesize += -((short) read_memory_unsigned_integer (current_pc, 2));
|
||
else if (((insn >> 8) == 0xe4) && /* ld24 r4, xxxxxx ; sub sp, r4 */
|
||
read_memory_unsigned_integer (current_pc + 2, 2) == 0x0f24)
|
||
{ /* subtract 24 bit sign-extended negative-offset */
|
||
insn = read_memory_unsigned_integer (current_pc - 2, 4);
|
||
if (insn & 0x00800000) /* sign extend */
|
||
insn |= 0xff000000; /* negative */
|
||
else
|
||
insn &= 0x00ffffff; /* positive */
|
||
framesize += insn;
|
||
}
|
||
else if (insn == 0x1d8f) /* mv fp, sp */
|
||
break; /* end of stack adjustments */
|
||
}
|
||
return framesize;
|
||
}
|
||
|
||
/* This function actually figures out the frame address for a given pc and
|
||
sp. This is tricky on the v850 because we only use an explicit frame
|
||
pointer when using alloca(). The only reliable way to get this info is to
|
||
examine the prologue.
|
||
*/
|
||
|
||
void
|
||
m32r_init_extra_frame_info (fi)
|
||
struct frame_info *fi;
|
||
{
|
||
int reg;
|
||
int framesize;
|
||
|
||
if (fi->next)
|
||
fi->pc = FRAME_SAVED_PC (fi->next);
|
||
|
||
framesize = m32r_scan_prologue (fi, &fi->fsr);
|
||
#if 0
|
||
if (PC_IN_CALL_DUMMY (fi->pc, NULL, NULL))
|
||
fi->frame = dummy_frame_stack->sp;
|
||
else
|
||
#endif
|
||
if (!fi->next)
|
||
fi->frame = read_register (SP_REGNUM);
|
||
|
||
for (reg = 0; reg < NUM_REGS; reg++)
|
||
if (fi->fsr.regs[reg] != 0)
|
||
fi->fsr.regs[reg] = fi->frame + framesize - fi->fsr.regs[reg];
|
||
}
|
||
|
||
/* Find the caller of this frame. We do this by seeing if RP_REGNUM is saved
|
||
in the stack anywhere, otherwise we get it from the registers. */
|
||
|
||
CORE_ADDR
|
||
m32r_find_callers_reg (fi, regnum)
|
||
struct frame_info *fi;
|
||
int regnum;
|
||
{
|
||
#if 0
|
||
/* XXX - Won't work if multiple dummy frames are active */
|
||
if (PC_IN_CALL_DUMMY (fi->pc, NULL, NULL))
|
||
switch (regnum)
|
||
{
|
||
case SP_REGNUM:
|
||
return dummy_frame_stack->sp;
|
||
break;
|
||
case FP_REGNUM:
|
||
return dummy_frame_stack->fp;
|
||
break;
|
||
case RP_REGNUM:
|
||
return dummy_frame_stack->pc;
|
||
break;
|
||
case PC_REGNUM:
|
||
return dummy_frame_stack->pc;
|
||
break;
|
||
}
|
||
|
||
#endif
|
||
for (; fi; fi = fi->next)
|
||
if (fi->fsr.regs[regnum] != 0)
|
||
return read_memory_integer (fi->fsr.regs[regnum], 4);
|
||
return read_register (regnum);
|
||
}
|
||
|
||
/* Given a GDB frame, determine the address of the calling function's frame.
|
||
This will be used to create a new GDB frame struct, and then
|
||
INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame.
|
||
For m32r, simply get the saved FP off the stack.
|
||
*/
|
||
|
||
CORE_ADDR
|
||
m32r_frame_chain (fi)
|
||
struct frame_info *fi;
|
||
{
|
||
CORE_ADDR saved_fp = fi->fsr.regs[FP_REGNUM];
|
||
CORE_ADDR fn_start, fn_end;
|
||
|
||
if (saved_fp != 0)
|
||
return read_memory_integer (saved_fp, 4);
|
||
else {
|
||
if (find_pc_partial_function (fi->pc, 0, &fn_start, &fn_end))
|
||
if (fn_start == entry_point_address ())
|
||
return 0; /* in _start fn, don't chain further */
|
||
else
|
||
return read_register (FP_REGNUM);
|
||
else /* in the woods, what to do? */
|
||
return 0; /* for now, play it safe and give up... */
|
||
}
|
||
}
|
||
|
||
/* All we do here is record SP and FP on the call dummy stack */
|
||
|
||
void
|
||
m32r_push_dummy_frame ()
|
||
{
|
||
struct dummy_frame *dummy_frame;
|
||
|
||
dummy_frame = xmalloc (sizeof (struct dummy_frame));
|
||
|
||
dummy_frame->fp = read_register (FP_REGNUM);
|
||
dummy_frame->sp = read_register (SP_REGNUM);
|
||
dummy_frame->rp = read_register (RP_REGNUM);
|
||
dummy_frame->pc = read_register (PC_REGNUM);
|
||
dummy_frame->next = dummy_frame_stack;
|
||
dummy_frame_stack = dummy_frame;
|
||
}
|
||
|
||
/*
|
||
* MISSING FUNCTION HEADER COMMENT
|
||
*/
|
||
|
||
int
|
||
m32r_pc_in_call_dummy (pc)
|
||
CORE_ADDR pc;
|
||
{
|
||
#if 0
|
||
return dummy_frame_stack
|
||
&& pc >= CALL_DUMMY_ADDRESS ()
|
||
&& pc <= CALL_DUMMY_ADDRESS () + DECR_PC_AFTER_BREAK;
|
||
#else
|
||
return 0;
|
||
#endif
|
||
}
|
||
|
||
/* Discard from the stack the innermost frame,
|
||
restoring all saved registers. */
|
||
|
||
struct frame_info *
|
||
m32r_pop_frame (frame)
|
||
struct frame_info *frame;
|
||
{
|
||
int regnum;
|
||
|
||
#if 0
|
||
if (PC_IN_CALL_DUMMY (frame->pc, NULL, NULL))
|
||
{
|
||
struct dummy_frame *dummy_frame;
|
||
|
||
dummy_frame = dummy_frame_stack;
|
||
if (!dummy_frame)
|
||
error ("Can't pop dummy frame!");
|
||
|
||
dummy_frame_stack = dummy_frame->next;
|
||
|
||
write_register (FP_REGNUM, dummy_frame->fp);
|
||
write_register (SP_REGNUM, dummy_frame->sp);
|
||
write_register (RP_REGNUM, dummy_frame->rp);
|
||
write_register (PC_REGNUM, dummy_frame->pc);
|
||
|
||
free (dummy_frame);
|
||
|
||
flush_cached_frames ();
|
||
|
||
return NULL;
|
||
}
|
||
|
||
#endif
|
||
write_register (PC_REGNUM, FRAME_SAVED_PC (frame));
|
||
|
||
for (regnum = 0; regnum < NUM_REGS; regnum++)
|
||
if (frame->fsr.regs[regnum] != 0)
|
||
write_register (regnum,
|
||
read_memory_integer (frame->fsr.regs[regnum], 4));
|
||
|
||
write_register (SP_REGNUM, read_register (FP_REGNUM));
|
||
if (read_register (PSW_REGNUM) & 0x80)
|
||
write_register (SPU_REGNUM, read_register (SP_REGNUM));
|
||
else
|
||
write_register (SPI_REGNUM, read_register (SP_REGNUM));
|
||
/* registers_changed (); */
|
||
flush_cached_frames ();
|
||
|
||
return NULL;
|
||
}
|
||
|
||
/* Put arguments in the right places, and setup return address register (RP) to
|
||
point at a convenient place to put a breakpoint. First four args go in
|
||
R6->R9, subsequent args go into sp + 16 -> sp + ... Structs are passed by
|
||
reference. 64 bit quantities (doubles and long longs) may be split between
|
||
the regs and the stack. When calling a function that returns a struct, a
|
||
pointer to the struct is passed in as a secret first argument (always in R6).
|
||
|
||
By the time we get here, stack space has been allocated for the args, but
|
||
not for the struct return pointer. */
|
||
|
||
CORE_ADDR
|
||
m32r_push_arguments (nargs, args, sp, struct_return, struct_addr)
|
||
int nargs;
|
||
value_ptr *args;
|
||
CORE_ADDR sp;
|
||
unsigned char struct_return;
|
||
CORE_ADDR struct_addr;
|
||
{
|
||
int argreg;
|
||
int argnum;
|
||
|
||
argreg = ARG0_REGNUM;
|
||
|
||
#if 0
|
||
if (struct_return)
|
||
{
|
||
write_register (argreg++, struct_addr);
|
||
sp -= 4;
|
||
}
|
||
|
||
for (argnum = 0; argnum < nargs; argnum++)
|
||
{
|
||
int len;
|
||
char *val;
|
||
char valbuf[4];
|
||
|
||
if (TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_STRUCT
|
||
&& TYPE_LENGTH (VALUE_TYPE (*args)) > 8)
|
||
{
|
||
store_address (valbuf, 4, VALUE_ADDRESS (*args));
|
||
len = 4;
|
||
val = valbuf;
|
||
}
|
||
else
|
||
{
|
||
len = TYPE_LENGTH (VALUE_TYPE (*args));
|
||
val = (char *)VALUE_CONTENTS (*args);
|
||
}
|
||
|
||
while (len > 0)
|
||
if (argreg <= ARGLAST_REGNUM)
|
||
{
|
||
CORE_ADDR regval;
|
||
|
||
regval = extract_address (val, REGISTER_RAW_SIZE (argreg));
|
||
write_register (argreg, regval);
|
||
|
||
len -= REGISTER_RAW_SIZE (argreg);
|
||
val += REGISTER_RAW_SIZE (argreg);
|
||
argreg++;
|
||
}
|
||
else
|
||
{
|
||
write_memory (sp + argnum * 4, val, 4);
|
||
|
||
len -= 4;
|
||
val += 4;
|
||
}
|
||
args++;
|
||
}
|
||
|
||
write_register (RP_REGNUM, entry_point_address ());
|
||
|
||
#endif
|
||
return sp;
|
||
}
|
||
|
||
void
|
||
_initialize_m32r_tdep ()
|
||
{
|
||
tm_print_insn = print_insn_m32r;
|
||
}
|