gdb/frame-unwind.c

   1 /* Definitions for frame unwinder, for GDB, the GNU debugger.
   2
   3    Copyright 2003 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 59 Temple Place - Suite 330,
  20    Boston, MA 02111-1307, USA.  */
  21
  22 #include "defs.h"
  23 #include "frame.h"
  24 #include "frame-unwind.h"
  25 #include "gdb_assert.h"
  26 #include "dummy-frame.h"
  27
  28 static struct gdbarch_data *frame_unwind_data;
  29
  30 struct frame_unwind_table
  31 {
  32   frame_unwind_p_ftype **p;
  33   frame_unwind_sniffer_ftype **sniffer;
  34   int nr;
  35 };
  36
  37 /* Append a predicate to the end of the table.  */
  38 static void
  39 append_predicate (struct frame_unwind_table *table, frame_unwind_p_ftype *p,
  40                   frame_unwind_sniffer_ftype *sniffer)
  41 {
  42   table->p = xrealloc (table->p, ((table->nr + 1)
  43                                   * sizeof (frame_unwind_p_ftype *)));
  44   table->sniffer = xrealloc (table->sniffer, ((table->nr + 1)
  45                                               * sizeof (frame_unwind_sniffer_ftype *)));
  46   table->p[table->nr] = p;
  47   table->sniffer[table->nr] = sniffer;
  48   table->nr++;
  49 }
  50
  51 static void *
  52 frame_unwind_init (struct gdbarch *gdbarch)
  53 {
  54   struct frame_unwind_table *table = XCALLOC (1, struct frame_unwind_table);
  55   append_predicate (table, dummy_frame_p, NULL);
  56   return table;
  57 }
  58
  59 static void
  60 frame_unwind_free (struct gdbarch *gdbarch, void *data)
  61 {
  62   struct frame_unwind_table *table =
  63     gdbarch_data (gdbarch, frame_unwind_data);
  64   xfree (table->p);
  65   xfree (table->sniffer);
  66   xfree (table);
  67 }
  68
  69 void
  70 frame_unwind_append_predicate (struct gdbarch *gdbarch,
  71                                frame_unwind_p_ftype *p)
  72 {
  73   struct frame_unwind_table *table =
  74     gdbarch_data (gdbarch, frame_unwind_data);
  75   if (table == NULL)
  76     {
  77       /* ULGH, called during architecture initialization.  Patch
  78          things up.  */
  79       table = frame_unwind_init (gdbarch);
  80       set_gdbarch_data (gdbarch, frame_unwind_data, table);
  81     }
  82   append_predicate (table, p, NULL);
  83 }
  84
  85 void
  86 frame_unwind_append_sniffer (struct gdbarch *gdbarch,
  87                              frame_unwind_sniffer_ftype *sniffer)
  88 {
  89   struct frame_unwind_table *table =
  90     gdbarch_data (gdbarch, frame_unwind_data);
  91   if (table == NULL)
  92     {
  93       /* ULGH, called during architecture initialization.  Patch
  94          things up.  */
  95       table = frame_unwind_init (gdbarch);
  96       set_gdbarch_data (gdbarch, frame_unwind_data, table);
  97     }
  98   append_predicate (table, NULL, sniffer);
  99 }
 100
 101 const struct frame_unwind *
 102 frame_unwind_find_by_frame (struct frame_info *next_frame)
 103 {
 104   int i;
 105   struct gdbarch *gdbarch = get_frame_arch (next_frame);
 106   struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
 107   if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES)
 108     /* Seriously old code.  Don't even try to use this new mechanism.
 109        (Note: The variable USE_GENERIC_DUMMY_FRAMES is deprecated, not
 110        the dummy frame mechanism.  All architectures should be using
 111        generic dummy frames).  */
 112     return legacy_saved_regs_unwind;
 113   for (i = 0; i < table->nr; i++)
 114     {
 115       const struct frame_unwind *desc;
 116       if (table->p[i] != NULL)
 117         desc = table->p[i] (frame_pc_unwind (next_frame));
 118       else if (table->sniffer[i] != NULL)
 119         desc = table->sniffer[i] (next_frame);
 120       else
 121         internal_error (__FILE__, __LINE__, "Missing sniffer?");
 122       if (desc != NULL)
 123         return desc;
 124     }
 125   return legacy_saved_regs_unwind;
 126 }
 127
 128 extern initialize_file_ftype _initialize_frame_unwind; /* -Wmissing-prototypes */
 129
 130 void
 131 _initialize_frame_unwind (void)
 132 {
 133   frame_unwind_data = register_gdbarch_data (frame_unwind_init,
 134                                              frame_unwind_free);
 135 }