OpenCores
URL https://opencores.org/ocsvn/openrisc/openrisc/trunk

Subversion Repositories openrisc

[/] [openrisc/] [trunk/] [gnu-old/] [gdb-6.8/] [gdb/] [dummy-frame.c] - Blame information for rev 827

Go to most recent revision | Details | Compare with Previous | View Log

Line No. Rev Author Line
1 24 jeremybenn
/* Code dealing with dummy stack frames, for GDB, the GNU debugger.
2
 
3
   Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
4
   1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2007, 2008
5
   Free Software Foundation, Inc.
6
 
7
   This file is part of GDB.
8
 
9
   This program is free software; you can redistribute it and/or modify
10
   it under the terms of the GNU General Public License as published by
11
   the Free Software Foundation; either version 3 of the License, or
12
   (at your option) any later version.
13
 
14
   This program is distributed in the hope that it will be useful,
15
   but WITHOUT ANY WARRANTY; without even the implied warranty of
16
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17
   GNU General Public License for more details.
18
 
19
   You should have received a copy of the GNU General Public License
20
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
21
 
22
 
23
#include "defs.h"
24
#include "dummy-frame.h"
25
#include "regcache.h"
26
#include "frame.h"
27
#include "inferior.h"
28
#include "gdb_assert.h"
29
#include "frame-unwind.h"
30
#include "command.h"
31
#include "gdbcmd.h"
32
#include "gdb_string.h"
33
 
34
/* Dummy frame.  This saves the processor state just prior to setting
35
   up the inferior function call.  Older targets save the registers
36
   on the target stack (but that really slows down function calls).  */
37
 
38
struct dummy_frame
39
{
40
  struct dummy_frame *next;
41
  /* This frame's ID.  Must match the value returned by
42
     gdbarch_unwind_dummy_id.  */
43
  struct frame_id id;
44
  /* The caller's regcache.  */
45
  struct regcache *regcache;
46
};
47
 
48
static struct dummy_frame *dummy_frame_stack = NULL;
49
 
50
/* Function: deprecated_pc_in_call_dummy (pc)
51
 
52
   Return non-zero if the PC falls in a dummy frame created by gdb for
53
   an inferior call.  The code below which allows gdbarch_decr_pc_after_break
54
   is for infrun.c, which may give the function a PC without that
55
   subtracted out.
56
 
57
   FIXME: cagney/2002-11-23: This is silly.  Surely "infrun.c" can
58
   figure out what the real PC (as in the resume address) is BEFORE
59
   calling this function.
60
 
61
   NOTE: cagney/2004-08-02: I'm pretty sure that, with the introduction of
62
   infrun.c:adjust_pc_after_break (thanks), this function is now
63
   always called with a correctly adjusted PC!
64
 
65
   NOTE: cagney/2004-08-02: Code should not need to call this.  */
66
 
67
int
68
deprecated_pc_in_call_dummy (CORE_ADDR pc)
69
{
70
  struct dummy_frame *dummyframe;
71
  for (dummyframe = dummy_frame_stack;
72
       dummyframe != NULL;
73
       dummyframe = dummyframe->next)
74
    {
75
      if ((pc >= dummyframe->id.code_addr)
76
          && (pc <= dummyframe->id.code_addr
77
                    + gdbarch_decr_pc_after_break (current_gdbarch)))
78
        return 1;
79
    }
80
  return 0;
81
}
82
 
83
/* Push the caller's state, along with the dummy frame info, onto a
84
   dummy-frame stack.  */
85
 
86
void
87
dummy_frame_push (struct regcache *caller_regcache,
88
                  const struct frame_id *dummy_id)
89
{
90
  struct gdbarch *gdbarch = get_regcache_arch (caller_regcache);
91
  struct dummy_frame *dummy_frame;
92
 
93
  /* Check to see if there are stale dummy frames, perhaps left over
94
     from when a longjump took us out of a function that was called by
95
     the debugger.  */
96
  dummy_frame = dummy_frame_stack;
97
  while (dummy_frame)
98
    /* FIXME: cagney/2004-08-02: Should just test IDs.  */
99
    if (frame_id_inner (gdbarch, dummy_frame->id, (*dummy_id)))
100
      /* Stale -- destroy!  */
101
      {
102
        dummy_frame_stack = dummy_frame->next;
103
        regcache_xfree (dummy_frame->regcache);
104
        xfree (dummy_frame);
105
        dummy_frame = dummy_frame_stack;
106
      }
107
    else
108
      dummy_frame = dummy_frame->next;
109
 
110
  dummy_frame = XZALLOC (struct dummy_frame);
111
  dummy_frame->regcache = caller_regcache;
112
  dummy_frame->id = (*dummy_id);
113
  dummy_frame->next = dummy_frame_stack;
114
  dummy_frame_stack = dummy_frame;
115
}
116
 
117
/* Return the dummy frame cache, it contains both the ID, and a
118
   pointer to the regcache.  */
119
struct dummy_frame_cache
120
{
121
  struct frame_id this_id;
122
  struct regcache *prev_regcache;
123
};
124
 
125
int
126
dummy_frame_sniffer (const struct frame_unwind *self,
127
                     struct frame_info *next_frame,
128
                     void **this_prologue_cache)
129
{
130
  struct dummy_frame *dummyframe;
131
  struct frame_id this_id;
132
 
133
  /* When unwinding a normal frame, the stack structure is determined
134
     by analyzing the frame's function's code (be it using brute force
135
     prologue analysis, or the dwarf2 CFI).  In the case of a dummy
136
     frame, that simply isn't possible.  The PC is either the program
137
     entry point, or some random address on the stack.  Trying to use
138
     that PC to apply standard frame ID unwind techniques is just
139
     asking for trouble.  */
140
 
141
  /* Don't bother unles there is at least one dummy frame.  */
142
  if (dummy_frame_stack != NULL)
143
    {
144
      /* Use an architecture specific method to extract the prev's
145
         dummy ID from the next frame.  Note that this method uses
146
         frame_register_unwind to obtain the register values needed to
147
         determine the dummy frame's ID.  */
148
      this_id = gdbarch_unwind_dummy_id (get_frame_arch (next_frame),
149
                                         next_frame);
150
 
151
      /* Use that ID to find the corresponding cache entry.  */
152
      for (dummyframe = dummy_frame_stack;
153
           dummyframe != NULL;
154
           dummyframe = dummyframe->next)
155
        {
156
          if (frame_id_eq (dummyframe->id, this_id))
157
            {
158
              struct dummy_frame_cache *cache;
159
              cache = FRAME_OBSTACK_ZALLOC (struct dummy_frame_cache);
160
              cache->prev_regcache = dummyframe->regcache;
161
              cache->this_id = this_id;
162
              (*this_prologue_cache) = cache;
163
              return 1;
164
            }
165
        }
166
    }
167
  return 0;
168
}
169
 
170
/* Given a call-dummy dummy-frame, return the registers.  Here the
171
   register value is taken from the local copy of the register buffer.  */
172
 
173
static void
174
dummy_frame_prev_register (struct frame_info *next_frame,
175
                           void **this_prologue_cache,
176
                           int regnum, int *optimized,
177
                           enum lval_type *lvalp, CORE_ADDR *addrp,
178
                           int *realnum, gdb_byte *bufferp)
179
{
180
  /* The dummy-frame sniffer always fills in the cache.  */
181
  struct dummy_frame_cache *cache = (*this_prologue_cache);
182
  gdb_assert (cache != NULL);
183
 
184
  /* Describe the register's location.  Generic dummy frames always
185
     have the register value in an ``expression''.  */
186
  *optimized = 0;
187
  *lvalp = not_lval;
188
  *addrp = 0;
189
  *realnum = -1;
190
 
191
  /* If needed, find and return the value of the register.  */
192
  if (bufferp != NULL)
193
    {
194
      /* Return the actual value.  */
195
      /* Use the regcache_cooked_read() method so that it, on the fly,
196
         constructs either a raw or pseudo register from the raw
197
         register cache.  */
198
      regcache_cooked_read (cache->prev_regcache, regnum, bufferp);
199
    }
200
}
201
 
202
/* Assuming that THIS frame is a dummy (remember, the NEXT and not
203
   THIS frame is passed in), return the ID of THIS frame.  That ID is
204
   determined by examining the NEXT frame's unwound registers using
205
   the method unwind_dummy_id().  As a side effect, THIS dummy frame's
206
   dummy cache is located and and saved in THIS_PROLOGUE_CACHE.  */
207
 
208
static void
209
dummy_frame_this_id (struct frame_info *next_frame,
210
                     void **this_prologue_cache,
211
                     struct frame_id *this_id)
212
{
213
  /* The dummy-frame sniffer always fills in the cache.  */
214
  struct dummy_frame_cache *cache = (*this_prologue_cache);
215
  gdb_assert (cache != NULL);
216
  (*this_id) = cache->this_id;
217
}
218
 
219
static const struct frame_unwind dummy_frame_unwinder =
220
{
221
  DUMMY_FRAME,
222
  dummy_frame_this_id,
223
  dummy_frame_prev_register,
224
  NULL,
225
  dummy_frame_sniffer,
226
};
227
 
228
const struct frame_unwind *const dummy_frame_unwind = {
229
  &dummy_frame_unwinder
230
};
231
 
232
static void
233
fprint_dummy_frames (struct ui_file *file)
234
{
235
  struct dummy_frame *s;
236
  for (s = dummy_frame_stack; s != NULL; s = s->next)
237
    {
238
      gdb_print_host_address (s, file);
239
      fprintf_unfiltered (file, ":");
240
      fprintf_unfiltered (file, " id=");
241
      fprint_frame_id (file, s->id);
242
      fprintf_unfiltered (file, "\n");
243
    }
244
}
245
 
246
static void
247
maintenance_print_dummy_frames (char *args, int from_tty)
248
{
249
  if (args == NULL)
250
    fprint_dummy_frames (gdb_stdout);
251
  else
252
    {
253
      struct ui_file *file = gdb_fopen (args, "w");
254
      if (file == NULL)
255
        perror_with_name (_("maintenance print dummy-frames"));
256
      fprint_dummy_frames (file);
257
      ui_file_delete (file);
258
    }
259
}
260
 
261
extern void _initialize_dummy_frame (void);
262
 
263
void
264
_initialize_dummy_frame (void)
265
{
266
  add_cmd ("dummy-frames", class_maintenance, maintenance_print_dummy_frames,
267
           _("Print the contents of the internal dummy-frame stack."),
268
           &maintenanceprintlist);
269
 
270
}

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.