Re: [patch/rfc] Add frame unwinder registrary

Andrew Cagney
2003-01-16T20:56:25Z

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[grr. diff -u vs diff -uN]. Attached are the new files.

[-- Attachment #2: frame-unwind.h --]
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/* Definitions for a frame unwinder, for GDB, the GNU debugger.

Copyright 2003 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. */

#if !defined (FRAME_UNWIND_H)
#define FRAME_UNWIND_H 1

struct frame_info;
struct frame_id;
struct frame_unwind;
struct gdbarch;
struct regcache;

/* Return the frame unwind methods for the function that contains PC,
or NULL if this this unwinder can't handle this frame. */

typedef const struct frame_unwind *(frame_unwind_p_ftype) (CORE_ADDR pc);

/* Add a frame unwinder to the list. The predicates are polled in the
order that they are appended. The initial list contains the dummy
frame's predicate. */

extern void frame_unwind_append_predicate (struct gdbarch *gdbarch,
frame_unwind_p_ftype *p);

/* Iterate through the list of frame unwinders until one returns an
implementation. */

extern const struct frame_unwind *frame_unwind_find_by_pc (struct gdbarch *gdbarch,
CORE_ADDR pc);

/* Return the location (and possibly value) of REGNUM for the previous
(older, up) frame. All parameters except VALUEP can be assumed to
be non NULL. When VALUEP is NULL, just the location of the
register should be returned.

UNWIND_CACHE is provided as mechanism for implementing a per-frame
local cache. It's initial value being NULL. Memory for that cache
should be allocated using frame_obstack_zalloc().

Register window architectures (eg SPARC) should note that REGNUM
identifies the register for the previous frame. For instance, a
request for the value of "o1" for the previous frame would be found
in the register "i1" in this FRAME. */

typedef void (frame_unwind_reg_ftype) (struct frame_info *frame,
void **unwind_cache,
int regnum,
int *optimized,
enum lval_type *lvalp,
CORE_ADDR *addrp,
int *realnump,
void *valuep);

/* Same as for registers above, but return the address at which the
calling frame would resume. */

typedef CORE_ADDR (frame_unwind_pc_ftype) (struct frame_info *frame,
void **unwind_cache);

/* Same as for registers above, but return the ID of the frame that
called this one. */

typedef void (frame_unwind_id_ftype) (struct frame_info *frame,
void **unwind_cache,
struct frame_id *id);

#ifdef NOT_YET
/* Pop the frame, writing the popped registers into the regcache. */

typedef void (frame_unwind_pop_ftype) (struct frame_info *frame,
void **unwind_cache,
struct regcache *regcache);
#endif

struct frame_unwind
{
/* Should the frame's type go here? */
/* Should an attribute indicating the frame's address-in-block go
here? */
frame_unwind_pc_ftype *pc;
frame_unwind_id_ftype *id;
frame_unwind_reg_ftype *reg;
#ifdef NOT_YET
frame_unwind_pop_ftype *pop;
#endif
};

#endif

[-- Attachment #3: frame-unwind.c --]
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/* Definitions for frame unwinder, for GDB, the GNU debugger.

Copyright 2003 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 "frame-unwind.h"
#include "gdb_assert.h"
#include "dummy-frame.h"

static struct gdbarch_data *frame_unwind_data;

struct frame_unwind_table
{
frame_unwind_p_ftype **p;
int middle;
int nr;
};

/* Append a predicate to the end of the table. */
static void
append_predicate (struct frame_unwind_table *table,
frame_unwind_p_ftype *p)
{
table->p = xrealloc (table->p, ((table->nr + 1)
* sizeof (frame_unwind_p_ftype *)));
table->p[table->nr] = p;
table->nr++;
}

static void *
frame_unwind_init (struct gdbarch *gdbarch)
{
struct frame_unwind_table *table = XCALLOC (1, struct frame_unwind_table);
append_predicate (table, dummy_frame_p);
return table;
}

static void
frame_unwind_free (struct gdbarch *gdbarch, void *data)
{
struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
xfree (table->p);
xfree (table);
}

void
frame_unwind_append_predicate (struct gdbarch *gdbarch,
frame_unwind_p_ftype *p)
{
struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
if (table == NULL)
{
/* ULGH, called during architecture initialization. Patch
things up. */
table = frame_unwind_init (gdbarch);
set_gdbarch_data (gdbarch, frame_unwind_data, table);
}
append_predicate (table, p);
}

const struct frame_unwind *
frame_unwind_find_by_pc (struct gdbarch *gdbarch, CORE_ADDR pc)
{
int i;
struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
/* Seriously old code. Don't even try to use this new mechanism. */
if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES)
return trad_frame_unwind;
for (i = 0; i < table->nr; i++)
{
const struct frame_unwind *desc = table->p[i] (pc);
if (desc != NULL)
return desc;
}
return trad_frame_unwind;
}

void
_initialize_frame_unwind (void)
{
frame_unwind_data = register_gdbarch_data (frame_unwind_init,
frame_unwind_free);
}