static CORE_ADDR
mn10300_analyze_prologue (struct frame_info *fi,
void **this_cache,
CORE_ADDR pc)
{
CORE_ADDR func_addr, func_end, addr, stop;
long stack_size;
int imm_size;
unsigned char buf[4];
int status, movm_args = 0;
char *name;
/* Use the PC in the frame if it's provided to look up the
start of this function.
Note: kevinb/2003-07-16: We used to do the following here:
pc = (fi ? get_frame_pc (fi) : pc);
But this is (now) badly broken when called from analyze_dummy_frame().
*/
if (fi)
{
pc = (pc ? pc : get_frame_pc (fi));
/* At the start of a function our frame is in the stack pointer. */
my_frame_is_in_sp (fi, this_cache);
}
/* Find the start of this function. */
status = find_pc_partial_function (pc, &name, &func_addr, &func_end);
/* Do nothing if we couldn't find the start of this function
MVS: comment went on to say "or if we're stopped at the first
instruction in the prologue" -- but code doesn't reflect that,
and I don't want to do that anyway. */
if (status == 0)
{
return pc;
}
/* If we're in start, then give up. */
if (strcmp (name, "start") == 0)
{
if (fi != NULL)
my_frame_is_last (fi);
return pc;
}
#if 0
/* Get the next two bytes into buf, we need two because rets is a two
byte insn and the first isn't enough to uniquely identify it. */
status = deprecated_read_memory_nobpt (pc, buf, 2);
if (status != 0)
return pc;
/* Note: kevinb/2003-07-16: We shouldn't be making these sorts of
changes to the frame in prologue examination code. */
/* If we're physically on an "rets" instruction, then our frame has
already been deallocated. Note this can also be true for retf
and ret if they specify a size of zero.
In this case fi->frame is bogus, we need to fix it. */
if (fi && buf[0] == 0xf0 && buf[1] == 0xfc)
{
if (get_next_frame (fi) == NULL)
deprecated_update_frame_base_hack (fi, read_sp ());
return get_frame_pc (fi);
}
/* Similarly if we're stopped on the first insn of a prologue as our
frame hasn't been allocated yet. */
if (fi && get_frame_pc (fi) == func_addr)
{
if (get_next_frame (fi) == NULL)
deprecated_update_frame_base_hack (fi, read_sp ());
return get_frame_pc (fi);
}
#endif
/* NOTE: from here on, we don't want to return without jumping to
finish_prologue. */
/* Figure out where to stop scanning. */
stop = fi ? pc : func_end;
/* Don't walk off the end of the function. */
stop = stop > func_end ? func_end : stop;
/* Start scanning on the first instruction of this function. */
addr = func_addr;
/* Suck in two bytes. */
if (addr + 2 >= stop
|| (status = deprecated_read_memory_nobpt (addr, buf, 2)) != 0)
goto finish_prologue;
/* First see if this insn sets the stack pointer from a register; if
so, it's probably the initialization of the stack pointer in _start,
so mark this as the bottom-most frame. */
if (buf[0] == 0xf2 && (buf[1] & 0xf3) == 0xf0)
{
if (fi)
my_frame_is_last (fi);
goto finish_prologue;
}
/* Now look for movm [regs],sp, which saves the callee saved registers.
At this time we don't know if fi->frame is valid, so we only note
that we encountered a movm instruction. Later, we'll set the entries
in fsr.regs as needed. */
if (buf[0] == 0xcf)
{
/* Extract the register list for the movm instruction. */
movm_args = buf[1];
addr += 2;
/* Quit now if we're beyond the stop point. */
if (addr >= stop)
goto finish_prologue;
/* Get the next two bytes so the prologue scan can continue. */
status = deprecated_read_memory_nobpt (addr, buf, 2);
if (status != 0)
goto finish_prologue;
}
/* Now see if we set up a frame pointer via "mov sp,a3" */
if (buf[0] == 0x3f)
{
addr += 1;
/* The frame pointer is now valid. */
if (fi)
{
my_frame_is_in_fp (fi, this_cache);
}
/* Quit now if we're beyond the stop point. */
if (addr >= stop)
goto finish_prologue;
/* Get two more bytes so scanning can continue. */
status = deprecated_read_memory_nobpt (addr, buf, 2);
if (status != 0)
goto finish_prologue;
}
/* Next we should allocate the local frame. No more prologue insns
are found after allocating the local frame.
Search for add imm8,sp (0xf8feXX)
or add imm16,sp (0xfafeXXXX)
or add imm32,sp (0xfcfeXXXXXXXX).
If none of the above was found, then this prologue has no
additional stack. */
imm_size = 0;
if (buf[0] == 0xf8 && buf[1] == 0xfe)
imm_size = 1;
else if (buf[0] == 0xfa && buf[1] == 0xfe)
imm_size = 2;
else if (buf[0] == 0xfc && buf[1] == 0xfe)
imm_size = 4;
if (imm_size != 0)
{
/* Suck in imm_size more bytes, they'll hold the size of the
current frame. */
status = deprecated_read_memory_nobpt (addr + 2, buf, imm_size);
if (status != 0)
goto finish_prologue;
/* Note the size of the stack in the frame info structure. */
stack_size = extract_signed_integer (buf, imm_size);
if (fi)
set_my_stack_size (fi, stack_size);
/* We just consumed 2 + imm_size bytes. */
addr += 2 + imm_size;
/* No more prologue insns follow, so begin preparation to return. */
goto finish_prologue;
}
/* Do the essentials and get out of here. */
finish_prologue:
/* Note if/where callee saved registers were saved. */
if (fi)
set_movm_offsets (fi, this_cache, movm_args);
return addr;
}
static CORE_ADDR
mn10300_analyze_prologue (struct frame_info *fi, CORE_ADDR pc)
{
CORE_ADDR func_addr, func_end, addr, stop;
CORE_ADDR stack_size;
int imm_size;
unsigned char buf[4];
int status, movm_args = 0;
char *name;
/* Use the PC in the frame if it's provided to look up the
start of this function. */
pc = (fi ? fi->pc : pc);
/* Find the start of this function. */
status = find_pc_partial_function (pc, &name, &func_addr, &func_end);
/* Do nothing if we couldn't find the start of this function or if we're
stopped at the first instruction in the prologue. */
if (status == 0)
{
return pc;
}
/* If we're in start, then give up. */
if (strcmp (name, "start") == 0)
{
if (fi != NULL)
fi->extra_info->status = NO_MORE_FRAMES;
return pc;
}
/* At the start of a function our frame is in the stack pointer. */
if (fi)
fi->extra_info->status = MY_FRAME_IN_SP;
/* Get the next two bytes into buf, we need two because rets is a two
byte insn and the first isn't enough to uniquely identify it. */
status = read_memory_nobpt (pc, buf, 2);
if (status != 0)
return pc;
/* If we're physically on an "rets" instruction, then our frame has
already been deallocated. Note this can also be true for retf
and ret if they specify a size of zero.
In this case fi->frame is bogus, we need to fix it. */
if (fi && buf[0] == 0xf0 && buf[1] == 0xfc)
{
if (fi->next == NULL)
fi->frame = read_sp ();
return fi->pc;
}
/* Similarly if we're stopped on the first insn of a prologue as our
frame hasn't been allocated yet. */
if (fi && fi->pc == func_addr)
{
if (fi->next == NULL)
fi->frame = read_sp ();
return fi->pc;
}
/* Figure out where to stop scanning. */
stop = fi ? fi->pc : func_end;
/* Don't walk off the end of the function. */
stop = stop > func_end ? func_end : stop;
/* Start scanning on the first instruction of this function. */
addr = func_addr;
/* Suck in two bytes. */
status = read_memory_nobpt (addr, buf, 2);
if (status != 0)
{
fix_frame_pointer (fi, 0);
return addr;
}
/* First see if this insn sets the stack pointer from a register; if
so, it's probably the initialization of the stack pointer in _start,
so mark this as the bottom-most frame. */
if (buf[0] == 0xf2 && (buf[1] & 0xf3) == 0xf0)
{
if (fi)
fi->extra_info->status = NO_MORE_FRAMES;
return addr;
}
/* Now look for movm [regs],sp, which saves the callee saved registers.
At this time we don't know if fi->frame is valid, so we only note
that we encountered a movm instruction. Later, we'll set the entries
in fsr.regs as needed. */
if (buf[0] == 0xcf)
{
/* Extract the register list for the movm instruction. */
status = read_memory_nobpt (addr + 1, buf, 1);
movm_args = *buf;
addr += 2;
/* Quit now if we're beyond the stop point. */
if (addr >= stop)
{
/* Fix fi->frame since it's bogus at this point. */
if (fi && fi->next == NULL)
fi->frame = read_sp ();
/* Note if/where callee saved registers were saved. */
set_movm_offsets (fi, movm_args);
return addr;
}
/* Get the next two bytes so the prologue scan can continue. */
status = read_memory_nobpt (addr, buf, 2);
if (status != 0)
{
/* Fix fi->frame since it's bogus at this point. */
if (fi && fi->next == NULL)
fi->frame = read_sp ();
/* Note if/where callee saved registers were saved. */
set_movm_offsets (fi, movm_args);
return addr;
}
}
/* Now see if we set up a frame pointer via "mov sp,a3" */
if (buf[0] == 0x3f)
{
addr += 1;
/* The frame pointer is now valid. */
if (fi)
{
fi->extra_info->status |= MY_FRAME_IN_FP;
fi->extra_info->status &= ~MY_FRAME_IN_SP;
}
/* Quit now if we're beyond the stop point. */
if (addr >= stop)
{
/* Fix fi->frame if it's bogus at this point. */
fix_frame_pointer (fi, 0);
/* Note if/where callee saved registers were saved. */
set_movm_offsets (fi, movm_args);
return addr;
}
/* Get two more bytes so scanning can continue. */
status = read_memory_nobpt (addr, buf, 2);
if (status != 0)
{
/* Fix fi->frame if it's bogus at this point. */
fix_frame_pointer (fi, 0);
/* Note if/where callee saved registers were saved. */
set_movm_offsets (fi, movm_args);
return addr;
}
}
/* Next we should allocate the local frame. No more prologue insns
are found after allocating the local frame.
Search for add imm8,sp (0xf8feXX)
or add imm16,sp (0xfafeXXXX)
or add imm32,sp (0xfcfeXXXXXXXX).
If none of the above was found, then this prologue has no
additional stack. */
status = read_memory_nobpt (addr, buf, 2);
if (status != 0)
{
/* Fix fi->frame if it's bogus at this point. */
fix_frame_pointer (fi, 0);
/* Note if/where callee saved registers were saved. */
set_movm_offsets (fi, movm_args);
return addr;
}
imm_size = 0;
if (buf[0] == 0xf8 && buf[1] == 0xfe)
imm_size = 1;
else if (buf[0] == 0xfa && buf[1] == 0xfe)
imm_size = 2;
else if (buf[0] == 0xfc && buf[1] == 0xfe)
imm_size = 4;
if (imm_size != 0)
{
/* Suck in imm_size more bytes, they'll hold the size of the
current frame. */
status = read_memory_nobpt (addr + 2, buf, imm_size);
if (status != 0)
{
/* Fix fi->frame if it's bogus at this point. */
fix_frame_pointer (fi, 0);
/* Note if/where callee saved registers were saved. */
set_movm_offsets (fi, movm_args);
return addr;
}
/* Note the size of the stack in the frame info structure. */
stack_size = extract_signed_integer (buf, imm_size);
if (fi)
fi->extra_info->stack_size = stack_size;
/* We just consumed 2 + imm_size bytes. */
addr += 2 + imm_size;
/* No more prologue insns follow, so begin preparation to return. */
/* Fix fi->frame if it's bogus at this point. */
fix_frame_pointer (fi, stack_size);
/* Note if/where callee saved registers were saved. */
set_movm_offsets (fi, movm_args);
return addr;
}
/* We never found an insn which allocates local stack space, regardless
this is the end of the prologue. */
/* Fix fi->frame if it's bogus at this point. */
fix_frame_pointer (fi, 0);
/* Note if/where callee saved registers were saved. */
set_movm_offsets (fi, movm_args);
return addr;
}
