xref: /freebsd/contrib/elftoolchain/libdwarf/libdwarf_abbrev.c (revision 389e4940069316fe667ffa263fa7d6390d0a960f)
1 /*-
2  * Copyright (c) 2007 John Birrell (jb@freebsd.org)
3  * Copyright (c) 2009-2011 Kai Wang
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include "_libdwarf.h"
29 
30 ELFTC_VCSID("$Id: libdwarf_abbrev.c 3420 2016-02-27 02:14:05Z emaste $");
31 
32 int
33 _dwarf_abbrev_add(Dwarf_CU cu, uint64_t entry, uint64_t tag, uint8_t children,
34     uint64_t aboff, Dwarf_Abbrev *abp, Dwarf_Error *error)
35 {
36 	Dwarf_Abbrev ab;
37 	Dwarf_Debug dbg;
38 
39 	dbg = cu != NULL ? cu->cu_dbg : NULL;
40 
41 	if ((ab = malloc(sizeof(struct _Dwarf_Abbrev))) == NULL) {
42 		DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
43 		return (DW_DLE_MEMORY);
44 	}
45 
46 	/* Initialise the abbrev structure. */
47 	ab->ab_entry	= entry;
48 	ab->ab_tag	= tag;
49 	ab->ab_children	= children;
50 	ab->ab_offset	= aboff;
51 	ab->ab_length	= 0;	/* fill in later. */
52 	ab->ab_atnum	= 0;	/* fill in later. */
53 
54 	/* Initialise the list of attribute definitions. */
55 	STAILQ_INIT(&ab->ab_attrdef);
56 
57 	/* Add the abbrev to the hash table of the compilation unit. */
58 	if (cu != NULL)
59 		HASH_ADD(ab_hh, cu->cu_abbrev_hash, ab_entry,
60 		    sizeof(ab->ab_entry), ab);
61 
62 	if (abp != NULL)
63 		*abp = ab;
64 
65 	return (DW_DLE_NONE);
66 }
67 
68 int
69 _dwarf_attrdef_add(Dwarf_Debug dbg, Dwarf_Abbrev ab, uint64_t attr,
70     uint64_t form, uint64_t adoff, Dwarf_AttrDef *adp, Dwarf_Error *error)
71 {
72 	Dwarf_AttrDef ad;
73 
74 	if (ab == NULL) {
75 		DWARF_SET_ERROR(dbg, error, DW_DLE_ARGUMENT);
76 		return (DW_DLE_ARGUMENT);
77 	}
78 
79 	if ((ad = malloc(sizeof(struct _Dwarf_AttrDef))) == NULL) {
80 		DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
81 		return (DW_DLE_MEMORY);
82 	}
83 
84 	/* Initialise the attribute definition structure. */
85 	ad->ad_attrib	= attr;
86 	ad->ad_form	= form;
87 	ad->ad_offset	= adoff;
88 
89 	/* Add the attribute definition to the list in the abbrev. */
90 	STAILQ_INSERT_TAIL(&ab->ab_attrdef, ad, ad_next);
91 
92 	/* Increase number of attribute counter. */
93 	ab->ab_atnum++;
94 
95 	if (adp != NULL)
96 		*adp = ad;
97 
98 	return (DW_DLE_NONE);
99 }
100 
101 int
102 _dwarf_abbrev_parse(Dwarf_Debug dbg, Dwarf_CU cu, Dwarf_Unsigned *offset,
103     Dwarf_Abbrev *abp, Dwarf_Error *error)
104 {
105 	Dwarf_Section *ds;
106 	uint64_t attr;
107 	uint64_t entry;
108 	uint64_t form;
109 	uint64_t aboff;
110 	uint64_t adoff;
111 	uint64_t tag;
112 	uint8_t children;
113 	int ret;
114 
115 	assert(abp != NULL);
116 
117 	ds = _dwarf_find_section(dbg, ".debug_abbrev");
118 	if (ds == NULL || *offset >= ds->ds_size)
119 		return (DW_DLE_NO_ENTRY);
120 
121 	aboff = *offset;
122 
123 	entry = _dwarf_read_uleb128(ds->ds_data, offset);
124 	if (entry == 0) {
125 		/* Last entry. */
126 		ret = _dwarf_abbrev_add(cu, entry, 0, 0, aboff, abp,
127 		    error);
128 		if (ret == DW_DLE_NONE) {
129 			(*abp)->ab_length = 1;
130 			return (ret);
131 		} else
132 			return (ret);
133 	}
134 	tag = _dwarf_read_uleb128(ds->ds_data, offset);
135 	children = dbg->read(ds->ds_data, offset, 1);
136 	if ((ret = _dwarf_abbrev_add(cu, entry, tag, children, aboff,
137 	    abp, error)) != DW_DLE_NONE)
138 		return (ret);
139 
140 	/* Parse attribute definitions. */
141 	do {
142 		adoff = *offset;
143 		attr = _dwarf_read_uleb128(ds->ds_data, offset);
144 		form = _dwarf_read_uleb128(ds->ds_data, offset);
145 		if (attr != 0)
146 			if ((ret = _dwarf_attrdef_add(dbg, *abp, attr,
147 			    form, adoff, NULL, error)) != DW_DLE_NONE)
148 				return (ret);
149 	} while (attr != 0);
150 
151 	(*abp)->ab_length = *offset - aboff;
152 
153 	return (ret);
154 }
155 
156 int
157 _dwarf_abbrev_find(Dwarf_CU cu, uint64_t entry, Dwarf_Abbrev *abp,
158     Dwarf_Error *error)
159 {
160 	Dwarf_Abbrev ab;
161 	Dwarf_Section *ds;
162 	Dwarf_Unsigned offset;
163 	int ret;
164 
165 	if (entry == 0)
166 		return (DW_DLE_NO_ENTRY);
167 
168 	/* Check if the desired abbrev entry is already in the hash table. */
169 	HASH_FIND(ab_hh, cu->cu_abbrev_hash, &entry, sizeof(entry), ab);
170 	if (ab != NULL) {
171 		*abp = ab;
172 		return (DW_DLE_NONE);
173 	}
174 
175 	if (cu->cu_abbrev_loaded) {
176 		return (DW_DLE_NO_ENTRY);
177 	}
178 
179 	/* Load and search the abbrev table. */
180 	ds = _dwarf_find_section(cu->cu_dbg, ".debug_abbrev");
181 	if (ds == NULL)
182 		return (DW_DLE_NO_ENTRY);
183 
184 	offset = cu->cu_abbrev_offset_cur;
185 	while (offset < ds->ds_size) {
186 		ret = _dwarf_abbrev_parse(cu->cu_dbg, cu, &offset, &ab, error);
187 		if (ret != DW_DLE_NONE)
188 			return (ret);
189 		if (ab->ab_entry == entry) {
190 			cu->cu_abbrev_offset_cur = offset;
191 			*abp = ab;
192 			return (DW_DLE_NONE);
193 		}
194 		if (ab->ab_entry == 0) {
195 			cu->cu_abbrev_offset_cur = offset;
196 			cu->cu_abbrev_loaded = 1;
197 			break;
198 		}
199 	}
200 
201 	return (DW_DLE_NO_ENTRY);
202 }
203 
204 void
205 _dwarf_abbrev_cleanup(Dwarf_CU cu)
206 {
207 	Dwarf_Abbrev ab, tab;
208 	Dwarf_AttrDef ad, tad;
209 
210 	assert(cu != NULL);
211 
212 	HASH_ITER(ab_hh, cu->cu_abbrev_hash, ab, tab) {
213 		HASH_DELETE(ab_hh, cu->cu_abbrev_hash, ab);
214 		STAILQ_FOREACH_SAFE(ad, &ab->ab_attrdef, ad_next, tad) {
215 			STAILQ_REMOVE(&ab->ab_attrdef, ad, _Dwarf_AttrDef,
216 			    ad_next);
217 			free(ad);
218 		}
219 		free(ab);
220 	}
221 }
222 
223 int
224 _dwarf_abbrev_gen(Dwarf_P_Debug dbg, Dwarf_Error *error)
225 {
226 	Dwarf_CU cu;
227 	Dwarf_Abbrev ab;
228 	Dwarf_AttrDef ad;
229 	Dwarf_P_Section ds;
230 	int ret;
231 
232 	cu = STAILQ_FIRST(&dbg->dbg_cu);
233 	if (cu == NULL)
234 		return (DW_DLE_NONE);
235 
236 	/* Create .debug_abbrev section. */
237 	if ((ret = _dwarf_section_init(dbg, &ds, ".debug_abbrev", 0, error)) !=
238 	    DW_DLE_NONE)
239 		return (ret);
240 
241 	for (ab = cu->cu_abbrev_hash; ab != NULL; ab = ab->ab_hh.next) {
242 		RCHECK(WRITE_ULEB128(ab->ab_entry));
243 		RCHECK(WRITE_ULEB128(ab->ab_tag));
244 		RCHECK(WRITE_VALUE(ab->ab_children, 1));
245 		STAILQ_FOREACH(ad, &ab->ab_attrdef, ad_next) {
246 			RCHECK(WRITE_ULEB128(ad->ad_attrib));
247 			RCHECK(WRITE_ULEB128(ad->ad_form));
248 		}
249 		/* Signal end of attribute spec list. */
250 		RCHECK(WRITE_ULEB128(0));
251 		RCHECK(WRITE_ULEB128(0));
252 	}
253 	/* End of abbreviation for this CU. */
254 	RCHECK(WRITE_ULEB128(0));
255 
256 	/* Notify the creation of .debug_abbrev ELF section. */
257 	RCHECK(_dwarf_section_callback(dbg, ds, SHT_PROGBITS, 0, 0, 0, error));
258 
259 	return (DW_DLE_NONE);
260 
261 gen_fail:
262 
263 	_dwarf_section_free(dbg, &ds);
264 
265 	return (ret);
266 }
267