gdb/frame-unwind.c

   1 /* Definitions for frame unwinder, for GDB, the GNU debugger.
   2
   3    Copyright 2003, 2004 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 #include "gdb_obstack.h"
  28
  29 static struct gdbarch_data *frame_unwind_data;
  30
  31 struct frame_unwind_table_entry
  32 {
  33   frame_unwind_sniffer_ftype *sniffer;
  34   const struct frame_unwind *unwinder;
  35   struct frame_unwind_table_entry *next;
  36 };
  37
  38 struct frame_unwind_table
  39 {
  40   struct frame_unwind_table_entry *head;
  41   struct frame_unwind_table_entry **tail;
  42 };
  43
  44 static void *
  45 frame_unwind_init (struct obstack *obstack)
  46 {
  47   struct frame_unwind_table *table
  48     = OBSTACK_ZALLOC (obstack, struct frame_unwind_table);
  49   table->head = OBSTACK_ZALLOC (obstack, struct frame_unwind_table_entry);
  50   table->head->sniffer = dummy_frame_sniffer;
  51   table->tail = &table->head->next;
  52   return table;
  53 }
  54
  55 void
  56 frame_unwind_append_sniffer (struct gdbarch *gdbarch,
  57                              frame_unwind_sniffer_ftype *sniffer)
  58 {
  59   struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
  60   (*table->tail) = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind_table_entry);
  61   (*table->tail)->sniffer = sniffer;
  62   table->tail = &((*table->tail)->next);
  63 }
  64
  65 void
  66 frame_unwind_register_unwinder (struct gdbarch *gdbarch,
  67                                 const struct frame_unwind *unwinder)
  68 {
  69   struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
  70   (*table->tail) = GDBARCH_OBSTACK_ZALLOC (gdbarch,
  71                                            struct frame_unwind_table_entry);
  72   (*table->tail)->unwinder = unwinder;
  73   table->tail = &((*table->tail)->next);
  74 }
  75
  76 const struct frame_unwind *
  77 frame_unwind_find_by_frame (struct frame_info *next_frame, void **this_cache)
  78 {
  79   int i;
  80   struct gdbarch *gdbarch = get_frame_arch (next_frame);
  81   struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
  82   struct frame_unwind_table_entry *entry;
  83   if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES && legacy_frame_p (gdbarch))
  84     /* Seriously old code.  Don't even try to use this new mechanism.
  85        (Note: The variable USE_GENERIC_DUMMY_FRAMES is deprecated, not
  86        the dummy frame mechanism.  All architectures should be using
  87        generic dummy frames).  */
  88     return legacy_saved_regs_unwind;
  89   for (entry = table->head; entry != NULL; entry = entry->next)
  90     {
  91       if (entry->sniffer != NULL)
  92         {
  93           const struct frame_unwind *desc = NULL;
  94           desc = entry->sniffer (next_frame);
  95           if (desc != NULL)
  96             return desc;
  97         }
  98       if (entry->unwinder != NULL)
  99         {
 100           if (entry->unwinder->sniffer (entry->unwinder, next_frame,
 101                                         this_cache))
 102             return entry->unwinder;
 103         }
 104     }
 105   return legacy_saved_regs_unwind;
 106 }
 107
 108 extern initialize_file_ftype _initialize_frame_unwind; /* -Wmissing-prototypes */
 109
 110 void
 111 _initialize_frame_unwind (void)
 112 {
 113   frame_unwind_data = gdbarch_data_register_pre_init (frame_unwind_init);
 114 }