libdw_visit_scopes.c revision 25b3c049e70834cf33790a28643ab058b507b35c 
1/* Helper functions to descend DWARF scope trees.
2   Copyright (C) 2005,2006,2007 Red Hat, Inc.
3   This file is part of Red Hat elfutils.
4
5   Red Hat elfutils is free software; you can redistribute it and/or modify
6   it under the terms of the GNU General Public License as published by the
7   Free Software Foundation; version 2 of the License.
8
9   Red Hat elfutils is distributed in the hope that it will be useful, but
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11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12   General Public License for more details.
13
14   You should have received a copy of the GNU General Public License along
15   with Red Hat elfutils; if not, write to the Free Software Foundation,
16   Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
17
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19   additional right to link the code of Red Hat elfutils with code licensed
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34   with Red Hat elfutils except the Non-GPL Code covered by this exception.
35   If you modify this file, you may extend this exception to your version
36   of the file, but you are not obligated to do so.  If you do not wish to
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39   the GPL without exception.
40
41   Red Hat elfutils is an included package of the Open Invention Network.
42   An included package of the Open Invention Network is a package for which
43   Open Invention Network licensees cross-license their patents.  No patent
44   license is granted, either expressly or impliedly, by designation as an
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47   <http://www.openinventionnetwork.com>.  */
48
49#ifdef HAVE_CONFIG_H
50# include <config.h>
51#endif
52
53#include "libdwP.h"
54#include <dwarf.h>
55
56enum die_class { ignore, match, match_inline, walk, imported };
57
58static enum die_class
59classify_die (Dwarf_Die *die)
60{
61  switch (INTUSE(dwarf_tag) (die))
62    {
63      /* DIEs with addresses we can try to match.  */
64    case DW_TAG_compile_unit:
65    case DW_TAG_module:
66    case DW_TAG_lexical_block:
67    case DW_TAG_with_stmt:
68    case DW_TAG_catch_block:
69    case DW_TAG_try_block:
70    case DW_TAG_entry_point:
71      return match;
72    case DW_TAG_inlined_subroutine:
73      return match_inline;
74    case DW_TAG_subprogram:
75      /* This might be a concrete out-of-line instance of an inline, in
76	 which case it is not guaranteed to be owned by the right scope and
77	 we will search for its origin as for DW_TAG_inlined_subroutine.  */
78      return (INTUSE(dwarf_hasattr) (die, DW_AT_abstract_origin)
79	      ? match_inline : match);
80
81      /* DIEs without addresses that can own DIEs with addresses.  */
82    case DW_TAG_namespace:
83    case DW_TAG_class_type:
84    case DW_TAG_structure_type:
85      return walk;
86
87      /* Special indirection required.  */
88    case DW_TAG_imported_unit:
89      return imported;
90
91      /* Other DIEs we have no reason to descend.  */
92    default:
93      break;
94    }
95  return ignore;
96}
97
98int
99__libdw_visit_scopes (depth, root, previsit, postvisit, arg)
100     unsigned int depth;
101     struct Dwarf_Die_Chain *root;
102     int (*previsit) (unsigned int depth, struct Dwarf_Die_Chain *, void *);
103     int (*postvisit) (unsigned int depth, struct Dwarf_Die_Chain *, void *);
104     void *arg;
105{
106  struct Dwarf_Die_Chain child;
107
108  child.parent = root;
109  if (INTUSE(dwarf_child) (&root->die, &child.die) != 0)
110    return -1;
111
112  inline int recurse (void)
113    {
114      return __libdw_visit_scopes (depth + 1, &child,
115				   previsit, postvisit, arg);
116    }
117
118  do
119    {
120      child.prune = false;
121
122      if (previsit != NULL)
123	{
124	  int result = (*previsit) (depth + 1, &child, arg);
125	  if (result != DWARF_CB_OK)
126	    return result;
127	}
128
129      if (!child.prune)
130	switch (classify_die (&child.die))
131	  {
132	  case match:
133	  case match_inline:
134	  case walk:
135	    if (INTUSE(dwarf_haschildren) (&child.die))
136	      {
137		int result = recurse ();
138		if (result != DWARF_CB_OK)
139		  return result;
140	      }
141	    break;
142
143	  case imported:
144	    {
145	      /* This imports another compilation unit to appear
146		 as part of this one, inside the current scope.
147		 Recurse to search the referenced unit, but without
148		 recording it as an inner scoping level.  */
149
150	      Dwarf_Attribute attr_mem;
151	      Dwarf_Attribute *attr = INTUSE(dwarf_attr) (&child.die,
152							  DW_AT_import,
153							  &attr_mem);
154	      if (INTUSE(dwarf_formref_die) (attr, &child.die) != NULL)
155		{
156		  int result = recurse ();
157		  if (result != DWARF_CB_OK)
158		    return result;
159		}
160	    }
161	    break;
162
163	  default:
164	    break;
165	  }
166
167      if (postvisit != NULL)
168	{
169	  int result = (*postvisit) (depth + 1, &child, arg);
170	  if (result != DWARF_CB_OK)
171	    return result;
172	}
173    }
174  while (INTUSE(dwarf_siblingof) (&child.die, &child.die) == 0);
175
176  return 0;
177}
178