1 /* Iterate through the debug line table.
2 Copyright (C) 2018 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
35
36 int
dwarf_next_lines(Dwarf * dbg,Dwarf_Off off,Dwarf_Off * next_off,Dwarf_CU ** cu,Dwarf_Files ** srcfiles,size_t * nfiles,Dwarf_Lines ** srclines,size_t * nlines)37 dwarf_next_lines (Dwarf *dbg, Dwarf_Off off,
38 Dwarf_Off *next_off, Dwarf_CU **cu,
39 Dwarf_Files **srcfiles, size_t *nfiles,
40 Dwarf_Lines **srclines, size_t *nlines)
41 {
42 /* Ignore existing errors. */
43 if (dbg == NULL)
44 return -1;
45
46 Elf_Data *lines = dbg->sectiondata[IDX_debug_line];
47 if (lines == NULL)
48 {
49 __libdw_seterrno (DWARF_E_NO_DEBUG_LINE);
50 return -1;
51 }
52
53 if (off == (Dwarf_Off) -1
54 || lines->d_size < 4
55 || off >= lines->d_size)
56 {
57 *next_off = (Dwarf_Off) -1;
58 return 1;
59 }
60
61 /* Read enough of the header to know where the next table is and
62 whether we need to lookup the CU (version < 5). */
63 const unsigned char *linep = lines->d_buf + off;
64 const unsigned char *lineendp = lines->d_buf + lines->d_size;
65
66 if ((size_t) (lineendp - linep) < 4)
67 {
68 invalid_data:
69 __libdw_seterrno (DWARF_E_INVALID_DEBUG_LINE);
70 return -1;
71 }
72
73 *next_off = off + 4;
74 Dwarf_Word unit_length = read_4ubyte_unaligned_inc (dbg, linep);
75 if (unit_length == DWARF3_LENGTH_64_BIT)
76 {
77 if ((size_t) (lineendp - linep) < 8)
78 goto invalid_data;
79 unit_length = read_8ubyte_unaligned_inc (dbg, linep);
80 *next_off += 8;
81 }
82
83 if (unit_length > (size_t) (lineendp - linep))
84 goto invalid_data;
85
86 *next_off += unit_length;
87 lineendp = linep + unit_length;
88
89 if ((size_t) (lineendp - linep) < 2)
90 goto invalid_data;
91 uint_fast16_t version = read_2ubyte_unaligned_inc (dbg, linep);
92
93 Dwarf_Die cudie;
94 if (version < 5)
95 {
96 /* We need to find the matching CU to get the comp_dir. Use the
97 given CU as hint where to start searching. Normally it will
98 be the next CU that has a statement list. */
99 Dwarf_CU *given_cu = *cu;
100 Dwarf_CU *next_cu = given_cu;
101 bool found = false;
102 while (dwarf_get_units (dbg, next_cu, &next_cu, NULL, NULL,
103 &cudie, NULL) == 0)
104 {
105 if (dwarf_hasattr (&cudie, DW_AT_stmt_list))
106 {
107 Dwarf_Attribute attr;
108 Dwarf_Word stmt_off;
109 if (dwarf_formudata (dwarf_attr (&cudie, DW_AT_stmt_list, &attr),
110 &stmt_off) == 0
111 && stmt_off == off)
112 {
113 found = true;
114 break;
115 }
116 }
117 else if (off == 0
118 && (next_cu->unit_type == DW_UT_split_compile
119 || next_cu->unit_type == DW_UT_split_type))
120 {
121 /* For split units (in .dwo files) there is only one table
122 at offset zero (containing just the files, no lines). */
123 found = true;
124 break;
125 }
126 }
127
128 if (!found && given_cu != NULL)
129 {
130 /* The CUs might be in a different order from the line
131 tables. Need to do a linear search (but stop at the given
132 CU, since we already searched those. */
133 next_cu = NULL;
134 while (dwarf_get_units (dbg, next_cu, &next_cu, NULL, NULL,
135 &cudie, NULL) == 0
136 && next_cu != given_cu)
137 {
138 Dwarf_Attribute attr;
139 Dwarf_Word stmt_off;
140 if (dwarf_formudata (dwarf_attr (&cudie, DW_AT_stmt_list, &attr),
141 &stmt_off) == 0
142 && stmt_off == off)
143 {
144 found = true;
145 break;
146 }
147 }
148 }
149
150 if (found)
151 *cu = next_cu;
152 else
153 *cu = NULL;
154 }
155 else
156 *cu = NULL;
157
158 const char *comp_dir;
159 unsigned address_size;
160 if (*cu != NULL)
161 {
162 comp_dir = __libdw_getcompdir (&cudie);
163 address_size = (*cu)->address_size;
164 }
165 else
166 {
167 comp_dir = NULL;
168
169 size_t esize;
170 char *ident = elf_getident (dbg->elf, &esize);
171 if (ident == NULL || esize < EI_NIDENT)
172 goto invalid_data;
173 address_size = ident[EI_CLASS] == ELFCLASS32 ? 4 : 8;
174 }
175
176 if (__libdw_getsrclines (dbg, off, comp_dir, address_size,
177 srclines, srcfiles) != 0)
178 return -1;
179
180 if (nlines != NULL)
181 {
182 if (srclines != NULL && *srclines != NULL)
183 *nlines = (*srclines)->nlines;
184 else
185 *nlines = 0;
186 }
187
188 if (nfiles != NULL)
189 {
190 if (srcfiles != NULL && *srcfiles != NULL)
191 *nfiles = (*srcfiles)->nfiles;
192 else
193 *nfiles = 0;
194 }
195
196 return 0;
197 }
198