8b36eed86d
* blockframe.c: Use get_frame_base instead of directly accessing the `struct frame_info' member frame. * f-valprint.c, std-regs.c, rs6000-tdep.c: Ditto. * stack.c, dummy-frame.c, breakpoint.c: Ditto.
345 lines
11 KiB
C
345 lines
11 KiB
C
/* Code dealing with dummy stack frames, for GDB, the GNU debugger.
|
|
|
|
Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
|
|
1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002 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 "dummy-frame.h"
|
|
#include "regcache.h"
|
|
#include "frame.h"
|
|
#include "inferior.h"
|
|
#include "gdb_assert.h"
|
|
|
|
/* Dummy frame. This saves the processor state just prior to setting
|
|
up the inferior function call. Older targets save the registers
|
|
on the target stack (but that really slows down function calls). */
|
|
|
|
struct dummy_frame
|
|
{
|
|
struct dummy_frame *next;
|
|
|
|
/* These values belong to the caller (the previous frame, the frame
|
|
that this unwinds back to). */
|
|
CORE_ADDR pc;
|
|
CORE_ADDR fp;
|
|
CORE_ADDR sp;
|
|
CORE_ADDR top;
|
|
struct regcache *regcache;
|
|
|
|
/* Address range of the call dummy code. Look for PC in the range
|
|
[LO..HI) (after allowing for DECR_PC_AFTER_BREAK). */
|
|
CORE_ADDR call_lo;
|
|
CORE_ADDR call_hi;
|
|
};
|
|
|
|
static struct dummy_frame *dummy_frame_stack = NULL;
|
|
|
|
/* Function: find_dummy_frame(pc, fp, sp)
|
|
|
|
Search the stack of dummy frames for one matching the given PC and
|
|
FP/SP. Unlike pc_in_dummy_frame(), this function doesn't need to
|
|
adjust for DECR_PC_AFTER_BREAK. This is because it is only legal
|
|
to call this function after the PC has been adjusted. */
|
|
|
|
static struct dummy_frame *
|
|
find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
|
|
{
|
|
struct dummy_frame *dummyframe;
|
|
|
|
for (dummyframe = dummy_frame_stack; dummyframe != NULL;
|
|
dummyframe = dummyframe->next)
|
|
{
|
|
/* Does the PC fall within the dummy frame's breakpoint
|
|
instruction. If not, discard this one. */
|
|
if (!(pc >= dummyframe->call_lo && pc < dummyframe->call_hi))
|
|
continue;
|
|
/* Does the FP match? */
|
|
if (dummyframe->top != 0)
|
|
{
|
|
/* If the target architecture explicitly saved the
|
|
top-of-stack before the inferior function call, assume
|
|
that that same architecture will always pass in an FP
|
|
(frame base) value that eactly matches that saved TOS.
|
|
Don't check the saved SP and SP as they can lead to false
|
|
hits. */
|
|
if (fp != dummyframe->top)
|
|
continue;
|
|
}
|
|
else
|
|
{
|
|
/* An older target that hasn't explicitly or implicitly
|
|
saved the dummy frame's top-of-stack. Try matching the
|
|
FP against the saved SP and FP. NOTE: If you're trying
|
|
to fix a problem with GDB not correctly finding a dummy
|
|
frame, check the comments that go with FRAME_ALIGN() and
|
|
SAVE_DUMMY_FRAME_TOS(). */
|
|
if (fp != dummyframe->fp && fp != dummyframe->sp)
|
|
continue;
|
|
}
|
|
/* The FP matches this dummy frame. */
|
|
return dummyframe;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
struct dummy_frame *
|
|
cached_find_dummy_frame (struct frame_info *frame, void **cache)
|
|
{
|
|
if ((*cache) == NULL)
|
|
(*cache) = find_dummy_frame (frame->pc, get_frame_base (frame));
|
|
return (*cache);
|
|
}
|
|
|
|
struct regcache *
|
|
generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
|
|
{
|
|
struct dummy_frame *dummy = find_dummy_frame (pc, fp);
|
|
if (dummy != NULL)
|
|
return dummy->regcache;
|
|
else
|
|
return NULL;
|
|
}
|
|
|
|
char *
|
|
deprecated_generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
|
|
{
|
|
struct regcache *regcache = generic_find_dummy_frame (pc, fp);
|
|
if (regcache == NULL)
|
|
return NULL;
|
|
return deprecated_grub_regcache_for_registers (regcache);
|
|
}
|
|
|
|
/* Function: pc_in_call_dummy (pc, sp, fp)
|
|
|
|
Return true if the PC falls in a dummy frame created by gdb for an
|
|
inferior call. The code below which allows DECR_PC_AFTER_BREAK is
|
|
for infrun.c, which may give the function a PC without that
|
|
subtracted out. */
|
|
|
|
int
|
|
generic_pc_in_call_dummy (CORE_ADDR pc, CORE_ADDR sp, CORE_ADDR fp)
|
|
{
|
|
return pc_in_dummy_frame (pc);
|
|
}
|
|
|
|
/* Return non-zero if the PC falls in a dummy frame.
|
|
|
|
The code below which allows DECR_PC_AFTER_BREAK is for infrun.c,
|
|
which may give the function a PC without that subtracted out.
|
|
|
|
FIXME: cagney/2002-11-23: This is silly. Surely "infrun.c" can
|
|
figure out what the real PC (as in the resume address) is BEFORE
|
|
calling this function (Oh, and I'm not even sure that this function
|
|
is called with an decremented PC, the call to pc_in_call_dummy() in
|
|
that file is conditional on !CALL_DUMMY_BREAKPOINT_OFFSET_P yet
|
|
generic dummy targets set CALL_DUMMY_BREAKPOINT_OFFSET. True?). */
|
|
|
|
int
|
|
pc_in_dummy_frame (CORE_ADDR pc)
|
|
{
|
|
struct dummy_frame *dummyframe;
|
|
for (dummyframe = dummy_frame_stack;
|
|
dummyframe != NULL;
|
|
dummyframe = dummyframe->next)
|
|
{
|
|
if ((pc >= dummyframe->call_lo)
|
|
&& (pc < dummyframe->call_hi + DECR_PC_AFTER_BREAK))
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Function: read_register_dummy
|
|
Find a saved register from before GDB calls a function in the inferior */
|
|
|
|
CORE_ADDR
|
|
deprecated_read_register_dummy (CORE_ADDR pc, CORE_ADDR fp, int regno)
|
|
{
|
|
struct regcache *dummy_regs = generic_find_dummy_frame (pc, fp);
|
|
|
|
if (dummy_regs)
|
|
{
|
|
/* NOTE: cagney/2002-08-12: Replaced a call to
|
|
regcache_raw_read_as_address() with a call to
|
|
regcache_cooked_read_unsigned(). The old, ...as_address
|
|
function was eventually calling extract_unsigned_integer (via
|
|
extract_address) to unpack the registers value. The below is
|
|
doing an unsigned extract so that it is functionally
|
|
equivalent. The read needs to be cooked as, otherwise, it
|
|
will never correctly return the value of a register in the
|
|
[NUM_REGS .. NUM_REGS+NUM_PSEUDO_REGS) range. */
|
|
ULONGEST val;
|
|
regcache_cooked_read_unsigned (dummy_regs, regno, &val);
|
|
return val;
|
|
}
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
/* Save all the registers on the dummy frame stack. Most ports save the
|
|
registers on the target stack. This results in lots of unnecessary memory
|
|
references, which are slow when debugging via a serial line. Instead, we
|
|
save all the registers internally, and never write them to the stack. The
|
|
registers get restored when the called function returns to the entry point,
|
|
where a breakpoint is laying in wait. */
|
|
|
|
void
|
|
generic_push_dummy_frame (void)
|
|
{
|
|
struct dummy_frame *dummy_frame;
|
|
CORE_ADDR fp = get_frame_base (get_current_frame ());
|
|
|
|
/* check to see if there are stale dummy frames,
|
|
perhaps left over from when a longjump took us out of a
|
|
function that was called by the debugger */
|
|
|
|
dummy_frame = dummy_frame_stack;
|
|
while (dummy_frame)
|
|
if (INNER_THAN (dummy_frame->fp, fp)) /* stale -- destroy! */
|
|
{
|
|
dummy_frame_stack = dummy_frame->next;
|
|
regcache_xfree (dummy_frame->regcache);
|
|
xfree (dummy_frame);
|
|
dummy_frame = dummy_frame_stack;
|
|
}
|
|
else
|
|
dummy_frame = dummy_frame->next;
|
|
|
|
dummy_frame = xmalloc (sizeof (struct dummy_frame));
|
|
dummy_frame->regcache = regcache_xmalloc (current_gdbarch);
|
|
|
|
dummy_frame->pc = read_pc ();
|
|
dummy_frame->sp = read_sp ();
|
|
dummy_frame->top = 0;
|
|
dummy_frame->fp = fp;
|
|
regcache_cpy (dummy_frame->regcache, current_regcache);
|
|
dummy_frame->next = dummy_frame_stack;
|
|
dummy_frame_stack = dummy_frame;
|
|
}
|
|
|
|
void
|
|
generic_save_dummy_frame_tos (CORE_ADDR sp)
|
|
{
|
|
dummy_frame_stack->top = sp;
|
|
}
|
|
|
|
/* Record the upper/lower bounds on the address of the call dummy. */
|
|
|
|
void
|
|
generic_save_call_dummy_addr (CORE_ADDR lo, CORE_ADDR hi)
|
|
{
|
|
dummy_frame_stack->call_lo = lo;
|
|
dummy_frame_stack->call_hi = hi;
|
|
}
|
|
|
|
/* Restore the machine state from either the saved dummy stack or a
|
|
real stack frame. */
|
|
|
|
void
|
|
generic_pop_current_frame (void (*popper) (struct frame_info * frame))
|
|
{
|
|
struct frame_info *frame = get_current_frame ();
|
|
if (get_frame_type (frame) == DUMMY_FRAME)
|
|
/* NOTE: cagney/2002-22-23: Does this ever occure? Surely a dummy
|
|
frame will have already been poped by the "infrun.c" code. */
|
|
generic_pop_dummy_frame ();
|
|
else
|
|
(*popper) (frame);
|
|
}
|
|
|
|
/* Function: pop_dummy_frame
|
|
Restore the machine state from a saved dummy stack frame. */
|
|
|
|
void
|
|
generic_pop_dummy_frame (void)
|
|
{
|
|
struct dummy_frame *dummy_frame = dummy_frame_stack;
|
|
|
|
/* FIXME: what if the first frame isn't the right one, eg..
|
|
because one call-by-hand function has done a longjmp into another one? */
|
|
|
|
if (!dummy_frame)
|
|
error ("Can't pop dummy frame!");
|
|
dummy_frame_stack = dummy_frame->next;
|
|
regcache_cpy (current_regcache, dummy_frame->regcache);
|
|
flush_cached_frames ();
|
|
|
|
regcache_xfree (dummy_frame->regcache);
|
|
xfree (dummy_frame);
|
|
}
|
|
|
|
/* Function: fix_call_dummy
|
|
Stub function. Generic dummy frames typically do not need to fix
|
|
the frame being created */
|
|
|
|
void
|
|
generic_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs,
|
|
struct value **args, struct type *type, int gcc_p)
|
|
{
|
|
return;
|
|
}
|
|
|
|
/* Given a call-dummy dummy-frame, return the registers. Here the
|
|
register value is taken from the local copy of the register buffer. */
|
|
|
|
void
|
|
dummy_frame_register_unwind (struct frame_info *frame, void **cache,
|
|
int regnum, int *optimized,
|
|
enum lval_type *lvalp, CORE_ADDR *addrp,
|
|
int *realnum, void *bufferp)
|
|
{
|
|
struct dummy_frame *dummy = cached_find_dummy_frame (frame, cache);
|
|
gdb_assert (dummy != NULL);
|
|
|
|
/* Describe the register's location. Generic dummy frames always
|
|
have the register value in an ``expression''. */
|
|
*optimized = 0;
|
|
*lvalp = not_lval;
|
|
*addrp = 0;
|
|
*realnum = -1;
|
|
|
|
/* If needed, find and return the value of the register. */
|
|
if (bufferp != NULL)
|
|
{
|
|
/* Return the actual value. */
|
|
/* Use the regcache_cooked_read() method so that it, on the fly,
|
|
constructs either a raw or pseudo register from the raw
|
|
register cache. */
|
|
regcache_cooked_read (dummy->regcache, regnum, bufferp);
|
|
}
|
|
}
|
|
|
|
CORE_ADDR
|
|
dummy_frame_pc_unwind (struct frame_info *frame,
|
|
void **cache)
|
|
{
|
|
struct dummy_frame *dummy = cached_find_dummy_frame (frame, cache);
|
|
/* Oops! In a dummy-frame but can't find the stack dummy. Pretend
|
|
that the frame doesn't unwind. Should this function instead
|
|
return a has-no-caller indication? */
|
|
if (dummy == NULL)
|
|
return 0;
|
|
return dummy->pc;
|
|
}
|
|
|