1 /* Helper functions to descend DWARF scope trees.
2 Copyright (C) 2005,2006,2007 Red Hat, Inc.
3 This file is part of elfutils.
4
5 This file is free software; you can redistribute it and/or modify
6 it under the terms of either
7
8 * the GNU Lesser General Public License as published by the Free
9 Software Foundation; either version 3 of the License, or (at
10 your option) any later version
11
12 or
13
14 * the GNU General Public License as published by the Free
15 Software Foundation; either version 2 of the License, or (at
16 your option) any later version
17
18 or both in parallel, as here.
19
20 elfutils is distributed in the hope that it will be useful, but
21 WITHOUT ANY WARRANTY; without even the implied warranty of
22 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23 General Public License for more details.
24
25 You should have received copies of the GNU General Public License and
26 the GNU Lesser General Public License along with this program. If
27 not, see <http://www.gnu.org/licenses/>. */
28
29 #ifdef HAVE_CONFIG_H
30 # include <config.h>
31 #endif
32
33 #include "libdwP.h"
34 #include <dwarf.h>
35
36
37 static bool
may_have_scopes(Dwarf_Die * die)38 may_have_scopes (Dwarf_Die *die)
39 {
40 switch (INTUSE(dwarf_tag) (die))
41 {
42 /* DIEs with addresses we can try to match. */
43 case DW_TAG_compile_unit:
44 case DW_TAG_module:
45 case DW_TAG_lexical_block:
46 case DW_TAG_with_stmt:
47 case DW_TAG_catch_block:
48 case DW_TAG_try_block:
49 case DW_TAG_entry_point:
50 case DW_TAG_inlined_subroutine:
51 case DW_TAG_subprogram:
52 return true;
53
54 /* DIEs without addresses that can own DIEs with addresses. */
55 case DW_TAG_namespace:
56 case DW_TAG_class_type:
57 case DW_TAG_structure_type:
58 return true;
59
60 /* Other DIEs we have no reason to descend. */
61 default:
62 break;
63 }
64 return false;
65 }
66
67 int
__libdw_visit_scopes(depth,root,previsit,postvisit,arg)68 __libdw_visit_scopes (depth, root, previsit, postvisit, arg)
69 unsigned int depth;
70 struct Dwarf_Die_Chain *root;
71 int (*previsit) (unsigned int depth, struct Dwarf_Die_Chain *, void *);
72 int (*postvisit) (unsigned int depth, struct Dwarf_Die_Chain *, void *);
73 void *arg;
74 {
75 struct Dwarf_Die_Chain child;
76 int ret;
77
78 child.parent = root;
79 if ((ret = INTUSE(dwarf_child) (&root->die, &child.die)) != 0)
80 return ret < 0 ? -1 : 0; // Having zero children is legal.
81
82 inline int recurse (void)
83 {
84 return __libdw_visit_scopes (depth + 1, &child,
85 previsit, postvisit, arg);
86 }
87
88 inline int walk_children ()
89 {
90 do
91 {
92 /* For an imported unit, it is logically as if the children of
93 that unit are siblings of the other children. So don't do
94 a full recursion into the imported unit, but just walk the
95 children in place before moving to the next real child. */
96 while (INTUSE(dwarf_tag) (&child.die) == DW_TAG_imported_unit)
97 {
98 Dwarf_Die orig_child_die = child.die;
99 Dwarf_Attribute attr_mem;
100 Dwarf_Attribute *attr = INTUSE(dwarf_attr) (&child.die,
101 DW_AT_import,
102 &attr_mem);
103 if (INTUSE(dwarf_formref_die) (attr, &child.die) != NULL
104 && INTUSE(dwarf_child) (&child.die, &child.die) == 0)
105 {
106 int result = walk_children ();
107 if (result != DWARF_CB_OK)
108 return result;
109 }
110
111 /* Any "real" children left? */
112 if ((ret = INTUSE(dwarf_siblingof) (&orig_child_die,
113 &child.die)) != 0)
114 return ret < 0 ? -1 : 0;
115 };
116
117 child.prune = false;
118
119 if (previsit != NULL)
120 {
121 int result = (*previsit) (depth + 1, &child, arg);
122 if (result != DWARF_CB_OK)
123 return result;
124 }
125
126 if (!child.prune && may_have_scopes (&child.die)
127 && INTUSE(dwarf_haschildren) (&child.die))
128 {
129 int result = recurse ();
130 if (result != DWARF_CB_OK)
131 return result;
132 }
133
134 if (postvisit != NULL)
135 {
136 int result = (*postvisit) (depth + 1, &child, arg);
137 if (result != DWARF_CB_OK)
138 return result;
139 }
140 }
141 while ((ret = INTUSE(dwarf_siblingof) (&child.die, &child.die)) == 0);
142
143 return ret < 0 ? -1 : 0;
144 }
145
146 return walk_children ();
147 }
148