1 /* $NetBSD: libdwarf_abbrev.c,v 1.5 2024/03/03 17:37:32 christos Exp $ */
2
3 /*-
4 * Copyright (c) 2007 John Birrell (jb@freebsd.org)
5 * Copyright (c) 2009-2011 Kai Wang
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #include "_libdwarf.h"
31
32 __RCSID("$NetBSD: libdwarf_abbrev.c,v 1.5 2024/03/03 17:37:32 christos Exp $");
33 ELFTC_VCSID("Id: libdwarf_abbrev.c 4008 2023-10-12 18:17:06Z kaiwang27");
34
35 int
_dwarf_abbrev_add(Dwarf_CU cu,uint64_t entry,uint64_t tag,uint8_t children,uint64_t aboff,Dwarf_Abbrev * abp,Dwarf_Error * error)36 _dwarf_abbrev_add(Dwarf_CU cu, uint64_t entry, uint64_t tag, uint8_t children,
37 uint64_t aboff, Dwarf_Abbrev *abp, Dwarf_Error *error)
38 {
39 Dwarf_Abbrev ab;
40 Dwarf_Debug dbg;
41
42 dbg = cu != NULL ? cu->cu_dbg : NULL;
43
44 if ((ab = malloc(sizeof(struct _Dwarf_Abbrev))) == NULL) {
45 DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
46 return (DW_DLE_MEMORY);
47 }
48
49 /* Initialise the abbrev structure. */
50 ab->ab_entry = entry;
51 ab->ab_tag = tag;
52 ab->ab_children = children;
53 ab->ab_offset = aboff;
54 ab->ab_length = 0; /* fill in later. */
55 ab->ab_atnum = 0; /* fill in later. */
56
57 /* Initialise the list of attribute definitions. */
58 STAILQ_INIT(&ab->ab_attrdef);
59
60 /* Add the abbrev to the hash table of the compilation unit. */
61 if (cu != NULL)
62 HASH_ADD(ab_hh, cu->cu_abbrev_hash, ab_entry,
63 sizeof(ab->ab_entry), ab);
64
65 *abp = ab;
66 return (DW_DLE_NONE);
67 }
68
69 int
_dwarf_attrdef_add(Dwarf_Debug dbg,Dwarf_Abbrev ab,uint64_t attr,uint64_t form,int64_t ic,uint64_t adoff,Dwarf_AttrDef * adp,Dwarf_Error * error)70 _dwarf_attrdef_add(Dwarf_Debug dbg, Dwarf_Abbrev ab, uint64_t attr,
71 uint64_t form, int64_t ic, uint64_t adoff, Dwarf_AttrDef *adp,
72 Dwarf_Error *error)
73 {
74 Dwarf_AttrDef ad;
75
76 if (ab == NULL) {
77 DWARF_SET_ERROR(dbg, error, DW_DLE_ARGUMENT);
78 return (DW_DLE_ARGUMENT);
79 }
80
81 if ((ad = malloc(sizeof(struct _Dwarf_AttrDef))) == NULL) {
82 DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
83 return (DW_DLE_MEMORY);
84 }
85
86 /* Initialise the attribute definition structure. */
87 ad->ad_attrib = attr;
88 ad->ad_form = form;
89 ad->ad_const = ic;
90 ad->ad_offset = adoff;
91
92 /* Add the attribute definition to the list in the abbrev. */
93 STAILQ_INSERT_TAIL(&ab->ab_attrdef, ad, ad_next);
94
95 /* Increase number of attribute counter. */
96 ab->ab_atnum++;
97
98 if (adp != NULL)
99 *adp = ad;
100
101 return (DW_DLE_NONE);
102 }
103
104 int
_dwarf_abbrev_parse(Dwarf_Debug dbg,Dwarf_CU cu,Dwarf_Unsigned * offset,Dwarf_Abbrev * abp,Dwarf_Error * error)105 _dwarf_abbrev_parse(Dwarf_Debug dbg, Dwarf_CU cu, Dwarf_Unsigned *offset,
106 Dwarf_Abbrev *abp, Dwarf_Error *error)
107 {
108 Dwarf_Section *ds;
109 uint64_t attr;
110 uint64_t entry;
111 uint64_t form;
112 uint64_t aboff;
113 uint64_t adoff;
114 uint64_t tag;
115 int64_t ic;
116 uint8_t children;
117 int ret;
118
119 assert(abp != NULL);
120
121 ds = _dwarf_find_section(dbg, ".debug_abbrev");
122 if (ds == NULL || *offset >= ds->ds_size)
123 return (DW_DLE_NO_ENTRY);
124
125 aboff = *offset;
126
127 entry = _dwarf_read_uleb128(ds->ds_data, offset);
128 if (entry == 0) {
129 /* Last entry. */
130 ret = _dwarf_abbrev_add(cu, entry, 0, 0, aboff, abp,
131 error);
132 if (ret == DW_DLE_NONE) {
133 (*abp)->ab_length = 1;
134 return (ret);
135 } else
136 return (ret);
137 }
138 tag = _dwarf_read_uleb128(ds->ds_data, offset);
139 children = dbg->read(ds->ds_data, offset, 1);
140 if ((ret = _dwarf_abbrev_add(cu, entry, tag, children, aboff,
141 abp, error)) != DW_DLE_NONE)
142 return (ret);
143
144 /* Parse attribute definitions. */
145 do {
146 adoff = *offset;
147 attr = _dwarf_read_uleb128(ds->ds_data, offset);
148 form = _dwarf_read_uleb128(ds->ds_data, offset);
149 if (form == DW_FORM_implicit_const) {
150 /*
151 * DWARF5 7.5.3: atrribute definition with the form
152 * DW_FORM_implicit_const contains a third part, a
153 * signed LEB128 value indicating a constant value.
154 * No value is needed to store in the .debug_info
155 * as a result.
156 */
157 ic = _dwarf_read_sleb128(ds->ds_data, offset);
158 }
159 if (attr != 0)
160 if ((ret = _dwarf_attrdef_add(dbg, *abp, attr,
161 form, ic, adoff, NULL, error)) != DW_DLE_NONE)
162 return (ret);
163 } while (attr != 0);
164
165 (*abp)->ab_length = *offset - aboff;
166
167 return (ret);
168 }
169
170 int
_dwarf_abbrev_find(Dwarf_CU cu,uint64_t entry,Dwarf_Abbrev * abp,Dwarf_Error * error)171 _dwarf_abbrev_find(Dwarf_CU cu, uint64_t entry, Dwarf_Abbrev *abp,
172 Dwarf_Error *error)
173 {
174 Dwarf_Abbrev ab;
175 Dwarf_Section *ds;
176 Dwarf_Unsigned offset;
177 int ret;
178
179 if (entry == 0)
180 return (DW_DLE_NO_ENTRY);
181
182 /* Check if the desired abbrev entry is already in the hash table. */
183 HASH_FIND(ab_hh, cu->cu_abbrev_hash, &entry, sizeof(entry), ab);
184 if (ab != NULL) {
185 *abp = ab;
186 return (DW_DLE_NONE);
187 }
188
189 if (cu->cu_abbrev_loaded) {
190 return (DW_DLE_NO_ENTRY);
191 }
192
193 /* Load and search the abbrev table. */
194 ds = _dwarf_find_section(cu->cu_dbg, ".debug_abbrev");
195 if (ds == NULL)
196 return (DW_DLE_NO_ENTRY);
197
198 offset = cu->cu_abbrev_offset_cur;
199 while (offset < ds->ds_size) {
200 ret = _dwarf_abbrev_parse(cu->cu_dbg, cu, &offset, &ab, error);
201 if (ret != DW_DLE_NONE)
202 return (ret);
203 if (ab->ab_entry == entry) {
204 cu->cu_abbrev_offset_cur = offset;
205 *abp = ab;
206 return (DW_DLE_NONE);
207 }
208 if (ab->ab_entry == 0) {
209 cu->cu_abbrev_offset_cur = offset;
210 cu->cu_abbrev_loaded = 1;
211 break;
212 }
213 }
214
215 return (DW_DLE_NO_ENTRY);
216 }
217
218 void
_dwarf_abbrev_cleanup(Dwarf_CU cu)219 _dwarf_abbrev_cleanup(Dwarf_CU cu)
220 {
221 Dwarf_Abbrev ab, tab;
222 Dwarf_AttrDef ad, tad;
223
224 assert(cu != NULL);
225
226 HASH_ITER(ab_hh, cu->cu_abbrev_hash, ab, tab) {
227 HASH_DELETE(ab_hh, cu->cu_abbrev_hash, ab);
228 STAILQ_FOREACH_SAFE(ad, &ab->ab_attrdef, ad_next, tad) {
229 STAILQ_REMOVE(&ab->ab_attrdef, ad, _Dwarf_AttrDef,
230 ad_next);
231 free(ad);
232 }
233 free(ab);
234 }
235 }
236
237 int
_dwarf_abbrev_gen(Dwarf_P_Debug dbg,Dwarf_Error * error)238 _dwarf_abbrev_gen(Dwarf_P_Debug dbg, Dwarf_Error *error)
239 {
240 Dwarf_CU cu;
241 Dwarf_Abbrev ab;
242 Dwarf_AttrDef ad;
243 Dwarf_P_Section ds;
244 int ret;
245
246 cu = STAILQ_FIRST(&dbg->dbg_cu);
247 if (cu == NULL)
248 return (DW_DLE_NONE);
249
250 /* Create .debug_abbrev section. */
251 if ((ret = _dwarf_section_init(dbg, &ds, ".debug_abbrev", 0, error)) !=
252 DW_DLE_NONE)
253 return (ret);
254
255 for (ab = cu->cu_abbrev_hash; ab != NULL; ab = ab->ab_hh.next) {
256 RCHECK(WRITE_ULEB128(ab->ab_entry));
257 RCHECK(WRITE_ULEB128(ab->ab_tag));
258 RCHECK(WRITE_VALUE(ab->ab_children, 1));
259 STAILQ_FOREACH(ad, &ab->ab_attrdef, ad_next) {
260 RCHECK(WRITE_ULEB128(ad->ad_attrib));
261 RCHECK(WRITE_ULEB128(ad->ad_form));
262 }
263 /* Signal end of attribute spec list. */
264 RCHECK(WRITE_ULEB128(0));
265 RCHECK(WRITE_ULEB128(0));
266 }
267 /* End of abbreviation for this CU. */
268 RCHECK(WRITE_ULEB128(0));
269
270 /* Notify the creation of .debug_abbrev ELF section. */
271 RCHECK(_dwarf_section_callback(dbg, ds, SHT_PROGBITS, 0, 0, 0, error));
272
273 return (DW_DLE_NONE);
274
275 gen_fail:
276
277 _dwarf_section_free(dbg, &ds);
278
279 return (ret);
280 }
281