1 /* Find a named variable or parameter within given scopes.
2 Copyright (C) 2005-2009 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
10 WITHOUT ANY WARRANTY; without even the implied warranty of
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
18 In addition, as a special exception, Red Hat, Inc. gives You the
19 additional right to link the code of Red Hat elfutils with code licensed
20 under any Open Source Initiative certified open source license
21 (http://www.opensource.org/licenses/index.php) which requires the
22 distribution of source code with any binary distribution and to
23 distribute linked combinations of the two. Non-GPL Code permitted under
24 this exception must only link to the code of Red Hat elfutils through
25 those well defined interfaces identified in the file named EXCEPTION
26 found in the source code files (the "Approved Interfaces"). The files
27 of Non-GPL Code may instantiate templates or use macros or inline
28 functions from the Approved Interfaces without causing the resulting
29 work to be covered by the GNU General Public License. Only Red Hat,
30 Inc. may make changes or additions to the list of Approved Interfaces.
31 Red Hat's grant of this exception is conditioned upon your not adding
32 any new exceptions. If you wish to add a new Approved Interface or
33 exception, please contact Red Hat. You must obey the GNU General Public
34 License in all respects for all of the Red Hat elfutils code and other
35 code used in conjunction with Red Hat elfutils except the Non-GPL Code
36 covered by this exception. If you modify this file, you may extend this
37 exception to your version of the file, but you are not obligated to do
38 so. If you do not wish to provide this exception without modification,
39 you must delete this exception statement from your version and license
40 this file solely under the GPL without exception.
41
42 Red Hat elfutils is an included package of the Open Invention Network.
43 An included package of the Open Invention Network is a package for which
44 Open Invention Network licensees cross-license their patents. No patent
45 license is granted, either expressly or impliedly, by designation as an
46 included package. Should you wish to participate in the Open Invention
47 Network licensing program, please visit www.openinventionnetwork.com
48 <http://www.openinventionnetwork.com>. */
49
50 #ifdef HAVE_CONFIG_H
51 # include <config.h>
52 #endif
53
54 #include <stdbool.h>
55 #include <string.h>
56 #include "libdwP.h"
57 #include <dwarf.h>
58
59
60 /* Find the containing CU's files. */
61 static int
getfiles(Dwarf_Die * die,Dwarf_Files ** files)62 getfiles (Dwarf_Die *die, Dwarf_Files **files)
63 {
64 return INTUSE(dwarf_getsrcfiles) (&CUDIE (die->cu), files, NULL);
65 }
66
67 /* Fetch an attribute that should have a constant integer form. */
68 static int
getattr(Dwarf_Die * die,int search_name,Dwarf_Word * value)69 getattr (Dwarf_Die *die, int search_name, Dwarf_Word *value)
70 {
71 Dwarf_Attribute attr_mem;
72 return INTUSE(dwarf_formudata) (INTUSE(dwarf_attr) (die, search_name,
73 &attr_mem), value);
74 }
75
76 /* Search SCOPES[0..NSCOPES-1] for a variable called NAME.
77 Ignore the first SKIP_SHADOWS scopes that match the name.
78 If MATCH_FILE is not null, accept only declaration in that source file;
79 if MATCH_LINENO or MATCH_LINECOL are also nonzero, accept only declaration
80 at that line and column.
81
82 If successful, fill in *RESULT with the DIE of the variable found,
83 and return N where SCOPES[N] is the scope defining the variable.
84 Return -1 for errors or -2 for no matching variable found. */
85
86 int
dwarf_getscopevar(Dwarf_Die * scopes,int nscopes,const char * name,int skip_shadows,const char * match_file,int match_lineno,int match_linecol,Dwarf_Die * result)87 dwarf_getscopevar (Dwarf_Die *scopes, int nscopes,
88 const char *name, int skip_shadows,
89 const char *match_file, int match_lineno, int match_linecol,
90 Dwarf_Die *result)
91 {
92 /* Match against the given file name. */
93 size_t match_file_len = match_file == NULL ? 0 : strlen (match_file);
94 bool lastfile_matches = false;
95 const char *lastfile = NULL;
96 inline bool file_matches (Dwarf_Files *files, size_t idx)
97 {
98 if (idx >= files->nfiles)
99 return false;
100
101 const char *file = files->info[idx].name;
102 if (file != lastfile)
103 {
104 size_t len = strlen (file);
105 lastfile_matches = (len >= match_file_len
106 && !memcmp (match_file, file, match_file_len)
107 && (len == match_file_len
108 || file[len - match_file_len - 1] == '/'));
109 }
110 return lastfile_matches;
111 }
112
113 /* Start with the innermost scope and move out. */
114 for (int out = 0; out < nscopes; ++out)
115 if (INTUSE(dwarf_haschildren) (&scopes[out]))
116 {
117 if (INTUSE(dwarf_child) (&scopes[out], result) != 0)
118 return -1;
119 do
120 {
121 switch (INTUSE(dwarf_tag) (result))
122 {
123 case DW_TAG_variable:
124 case DW_TAG_formal_parameter:
125 break;
126
127 default:
128 continue;
129 }
130
131 /* Only get here for a variable or parameter. Check the name. */
132 const char *diename = INTUSE(dwarf_diename) (result);
133 if (diename != NULL && !strcmp (name, diename))
134 {
135 /* We have a matching name. */
136
137 if (skip_shadows > 0)
138 {
139 /* Punt this scope for the one it shadows. */
140 --skip_shadows;
141 break;
142 }
143
144 if (match_file != NULL)
145 {
146 /* Check its decl_file. */
147
148 Dwarf_Word i;
149 Dwarf_Files *files;
150 if (getattr (result, DW_AT_decl_file, &i) != 0
151 || getfiles (&scopes[out], &files) != 0)
152 break;
153
154 if (!file_matches (files, i))
155 break;
156
157 if (match_lineno > 0
158 && (getattr (result, DW_AT_decl_line, &i) != 0
159 || (int) i != match_lineno))
160 break;
161 if (match_linecol > 0
162 && (getattr (result, DW_AT_decl_column, &i) != 0
163 || (int) i != match_linecol))
164 break;
165 }
166
167 /* We have a winner! */
168 return out;
169 }
170 }
171 while (INTUSE(dwarf_siblingof) (result, result) == 0);
172 }
173
174 return -2;
175 }
176