]>
Commit | Line | Data |
---|---|---|
3054dd54 TT |
1 | /* DWARF 2 abbreviations |
2 | ||
4a94e368 | 3 | Copyright (C) 1994-2022 Free Software Foundation, Inc. |
3054dd54 TT |
4 | |
5 | Adapted by Gary Funck (gary@intrepid.com), Intrepid Technology, | |
6 | Inc. with support from Florida State University (under contract | |
7 | with the Ada Joint Program Office), and Silicon Graphics, Inc. | |
8 | Initial contribution by Brent Benson, Harris Computer Systems, Inc., | |
9 | based on Fred Fish's (Cygnus Support) implementation of DWARF 1 | |
10 | support. | |
11 | ||
12 | This file is part of GDB. | |
13 | ||
14 | This program is free software; you can redistribute it and/or modify | |
15 | it under the terms of the GNU General Public License as published by | |
16 | the Free Software Foundation; either version 3 of the License, or | |
17 | (at your option) any later version. | |
18 | ||
19 | This program is distributed in the hope that it will be useful, | |
20 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
21 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
22 | GNU General Public License for more details. | |
23 | ||
24 | You should have received a copy of the GNU General Public License | |
25 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
26 | ||
27 | #include "defs.h" | |
82ca8957 | 28 | #include "dwarf2/read.h" |
3054dd54 TT |
29 | #include "dwarf2/abbrev.h" |
30 | #include "dwarf2/leb.h" | |
31 | #include "bfd.h" | |
32 | ||
1d33d811 TT |
33 | /* Hash function for an abbrev. */ |
34 | ||
35 | static hashval_t | |
36 | hash_abbrev (const void *item) | |
37 | { | |
38 | const struct abbrev_info *info = (const struct abbrev_info *) item; | |
af0b2a3e TT |
39 | /* Warning: if you change this next line, you must also update the |
40 | other code in this class using the _with_hash functions. */ | |
1d33d811 TT |
41 | return info->number; |
42 | } | |
43 | ||
44 | /* Comparison function for abbrevs. */ | |
45 | ||
46 | static int | |
47 | eq_abbrev (const void *lhs, const void *rhs) | |
48 | { | |
49 | const struct abbrev_info *l_info = (const struct abbrev_info *) lhs; | |
50 | const struct abbrev_info *r_info = (const struct abbrev_info *) rhs; | |
51 | return l_info->number == r_info->number; | |
52 | } | |
53 | ||
3054dd54 TT |
54 | /* Abbreviation tables. |
55 | ||
56 | In DWARF version 2, the description of the debugging information is | |
57 | stored in a separate .debug_abbrev section. Before we read any | |
58 | dies from a section we read in all abbreviations and install them | |
59 | in a hash table. */ | |
60 | ||
8c831774 | 61 | abbrev_table::abbrev_table (sect_offset off, struct dwarf2_section_info *sect) |
1d33d811 | 62 | : sect_off (off), |
8c831774 | 63 | section (sect), |
1d33d811 TT |
64 | m_abbrevs (htab_create_alloc (20, hash_abbrev, eq_abbrev, |
65 | nullptr, xcalloc, xfree)) | |
66 | { | |
67 | } | |
68 | ||
3054dd54 TT |
69 | /* Add an abbreviation to the table. */ |
70 | ||
71 | void | |
af0b2a3e | 72 | abbrev_table::add_abbrev (struct abbrev_info *abbrev) |
3054dd54 | 73 | { |
af0b2a3e TT |
74 | void **slot = htab_find_slot_with_hash (m_abbrevs.get (), abbrev, |
75 | abbrev->number, INSERT); | |
1d33d811 | 76 | *slot = abbrev; |
3054dd54 TT |
77 | } |
78 | ||
696eef26 TT |
79 | /* Helper function that returns true if a DIE with the given tag might |
80 | plausibly be indexed. */ | |
81 | ||
82 | static bool | |
83 | tag_interesting_for_index (dwarf_tag tag) | |
84 | { | |
85 | switch (tag) | |
86 | { | |
87 | case DW_TAG_array_type: | |
88 | case DW_TAG_base_type: | |
89 | case DW_TAG_class_type: | |
90 | case DW_TAG_constant: | |
91 | case DW_TAG_enumeration_type: | |
92 | case DW_TAG_enumerator: | |
93 | case DW_TAG_imported_declaration: | |
94 | case DW_TAG_imported_unit: | |
95 | case DW_TAG_inlined_subroutine: | |
96 | case DW_TAG_interface_type: | |
97 | case DW_TAG_module: | |
98 | case DW_TAG_namespace: | |
99 | case DW_TAG_ptr_to_member_type: | |
100 | case DW_TAG_set_type: | |
101 | case DW_TAG_string_type: | |
102 | case DW_TAG_structure_type: | |
103 | case DW_TAG_subprogram: | |
104 | case DW_TAG_subrange_type: | |
105 | case DW_TAG_generic_subrange: | |
106 | case DW_TAG_subroutine_type: | |
107 | case DW_TAG_typedef: | |
108 | case DW_TAG_union_type: | |
109 | case DW_TAG_unspecified_type: | |
110 | case DW_TAG_variable: | |
111 | return true; | |
112 | } | |
113 | ||
114 | return false; | |
115 | } | |
116 | ||
3054dd54 TT |
117 | /* Read in an abbrev table. */ |
118 | ||
119 | abbrev_table_up | |
606decb2 | 120 | abbrev_table::read (struct dwarf2_section_info *section, |
86de1d91 | 121 | sect_offset sect_off) |
3054dd54 TT |
122 | { |
123 | bfd *abfd = section->get_bfd_owner (); | |
124 | const gdb_byte *abbrev_ptr; | |
125 | struct abbrev_info *cur_abbrev; | |
3054dd54 | 126 | |
8c831774 | 127 | abbrev_table_up abbrev_table (new struct abbrev_table (sect_off, section)); |
4444f407 | 128 | struct obstack *obstack = &abbrev_table->m_abbrev_obstack; |
3054dd54 | 129 | |
606decb2 TT |
130 | /* Caller must ensure this. */ |
131 | gdb_assert (section->readin); | |
3054dd54 | 132 | abbrev_ptr = section->buffer + to_underlying (sect_off); |
3054dd54 | 133 | |
27012aba | 134 | while (true) |
3054dd54 | 135 | { |
27012aba TT |
136 | unsigned int bytes_read; |
137 | /* Loop until we reach an abbrev number of 0. */ | |
138 | unsigned int abbrev_number = read_unsigned_leb128 (abfd, abbrev_ptr, | |
139 | &bytes_read); | |
140 | if (abbrev_number == 0) | |
141 | break; | |
142 | abbrev_ptr += bytes_read; | |
143 | ||
4444f407 TT |
144 | /* Start without any attrs. */ |
145 | obstack_blank (obstack, offsetof (abbrev_info, attrs)); | |
146 | cur_abbrev = (struct abbrev_info *) obstack_base (obstack); | |
3054dd54 | 147 | |
4444f407 | 148 | /* Read in abbrev header. */ |
3054dd54 TT |
149 | cur_abbrev->number = abbrev_number; |
150 | cur_abbrev->tag | |
4444f407 TT |
151 | = (enum dwarf_tag) read_unsigned_leb128 (abfd, abbrev_ptr, |
152 | &bytes_read); | |
3054dd54 TT |
153 | abbrev_ptr += bytes_read; |
154 | cur_abbrev->has_children = read_1_byte (abfd, abbrev_ptr); | |
155 | abbrev_ptr += 1; | |
156 | ||
696eef26 TT |
157 | unsigned int size = 0; |
158 | unsigned int sibling_offset = -1; | |
159 | bool is_csize = true; | |
160 | ||
161 | bool has_hardcoded_declaration = false; | |
162 | bool has_specification_or_origin = false; | |
163 | bool has_name = false; | |
164 | bool has_linkage_name = false; | |
165 | bool has_location = false; | |
166 | bool has_external = false; | |
167 | ||
4444f407 TT |
168 | /* Now read in declarations. */ |
169 | int num_attrs = 0; | |
3054dd54 TT |
170 | for (;;) |
171 | { | |
4444f407 | 172 | struct attr_abbrev cur_attr; |
3054dd54 | 173 | |
4444f407 TT |
174 | cur_attr.name |
175 | = (enum dwarf_attribute) read_unsigned_leb128 (abfd, abbrev_ptr, | |
176 | &bytes_read); | |
3054dd54 | 177 | abbrev_ptr += bytes_read; |
4444f407 TT |
178 | cur_attr.form |
179 | = (enum dwarf_form) read_unsigned_leb128 (abfd, abbrev_ptr, | |
180 | &bytes_read); | |
3054dd54 | 181 | abbrev_ptr += bytes_read; |
4444f407 | 182 | if (cur_attr.form == DW_FORM_implicit_const) |
3054dd54 | 183 | { |
4444f407 TT |
184 | cur_attr.implicit_const = read_signed_leb128 (abfd, abbrev_ptr, |
185 | &bytes_read); | |
3054dd54 TT |
186 | abbrev_ptr += bytes_read; |
187 | } | |
188 | else | |
4444f407 | 189 | cur_attr.implicit_const = -1; |
3054dd54 | 190 | |
4444f407 | 191 | if (cur_attr.name == 0) |
3054dd54 TT |
192 | break; |
193 | ||
696eef26 TT |
194 | switch (cur_attr.name) |
195 | { | |
196 | case DW_AT_declaration: | |
197 | if (cur_attr.form == DW_FORM_flag_present) | |
198 | has_hardcoded_declaration = true; | |
199 | break; | |
200 | ||
201 | case DW_AT_external: | |
202 | has_external = true; | |
203 | break; | |
204 | ||
205 | case DW_AT_specification: | |
206 | case DW_AT_abstract_origin: | |
207 | case DW_AT_extension: | |
208 | has_specification_or_origin = true; | |
209 | break; | |
210 | ||
211 | case DW_AT_name: | |
212 | has_name = true; | |
213 | break; | |
214 | ||
215 | case DW_AT_MIPS_linkage_name: | |
216 | case DW_AT_linkage_name: | |
217 | has_linkage_name = true; | |
218 | break; | |
219 | ||
220 | case DW_AT_const_value: | |
221 | case DW_AT_location: | |
222 | has_location = true; | |
223 | break; | |
224 | ||
225 | case DW_AT_sibling: | |
226 | if (is_csize && cur_attr.form == DW_FORM_ref4) | |
227 | sibling_offset = size; | |
228 | break; | |
229 | } | |
230 | ||
231 | switch (cur_attr.form) | |
232 | { | |
233 | case DW_FORM_data1: | |
234 | case DW_FORM_ref1: | |
235 | case DW_FORM_flag: | |
236 | case DW_FORM_strx1: | |
237 | size += 1; | |
238 | break; | |
239 | case DW_FORM_flag_present: | |
240 | case DW_FORM_implicit_const: | |
241 | break; | |
242 | case DW_FORM_data2: | |
243 | case DW_FORM_ref2: | |
244 | case DW_FORM_strx2: | |
245 | size += 2; | |
246 | break; | |
247 | case DW_FORM_strx3: | |
248 | size += 3; | |
249 | break; | |
250 | case DW_FORM_data4: | |
251 | case DW_FORM_ref4: | |
252 | case DW_FORM_strx4: | |
253 | size += 4; | |
254 | break; | |
255 | case DW_FORM_data8: | |
256 | case DW_FORM_ref8: | |
257 | case DW_FORM_ref_sig8: | |
258 | size += 8; | |
259 | break; | |
260 | case DW_FORM_data16: | |
261 | size += 16; | |
262 | break; | |
263 | ||
264 | default: | |
265 | is_csize = false; | |
266 | break; | |
267 | } | |
268 | ||
4444f407 TT |
269 | ++num_attrs; |
270 | obstack_grow (obstack, &cur_attr, sizeof (cur_attr)); | |
3054dd54 TT |
271 | } |
272 | ||
4444f407 TT |
273 | cur_abbrev = (struct abbrev_info *) obstack_finish (obstack); |
274 | cur_abbrev->num_attrs = num_attrs; | |
696eef26 TT |
275 | |
276 | if (!has_name && !has_linkage_name && !has_specification_or_origin) | |
277 | { | |
278 | /* Some anonymous DIEs are worth examining. */ | |
279 | cur_abbrev->interesting | |
280 | = (cur_abbrev->tag == DW_TAG_namespace | |
281 | || cur_abbrev->tag == DW_TAG_enumeration_type); | |
282 | } | |
6acc36f7 TT |
283 | else if ((cur_abbrev->tag == DW_TAG_structure_type |
284 | || cur_abbrev->tag == DW_TAG_class_type | |
285 | || cur_abbrev->tag == DW_TAG_union_type) | |
286 | && cur_abbrev->has_children) | |
287 | { | |
288 | /* We have to record this as interesting, regardless of how | |
289 | DW_AT_declaration is set, so that any subsequent | |
290 | DW_AT_specification pointing at a child of this will get | |
291 | the correct scope. */ | |
292 | cur_abbrev->interesting = true; | |
293 | } | |
696eef26 TT |
294 | else if (has_hardcoded_declaration |
295 | && (cur_abbrev->tag != DW_TAG_variable || !has_external)) | |
296 | cur_abbrev->interesting = false; | |
297 | else if (!tag_interesting_for_index (cur_abbrev->tag)) | |
298 | cur_abbrev->interesting = false; | |
299 | else if (!has_location && !has_specification_or_origin && !has_external | |
300 | && cur_abbrev->tag == DW_TAG_variable) | |
301 | cur_abbrev->interesting = false; | |
302 | else | |
303 | cur_abbrev->interesting = true; | |
304 | ||
305 | /* If there are no children, and the abbrev has a constant size, | |
306 | then we don't care about the sibling offset, because it's | |
307 | simple to just skip the entire DIE without reading a sibling | |
308 | offset. */ | |
309 | if ((!cur_abbrev->has_children && is_csize) | |
310 | /* Overflow. */ | |
311 | || sibling_offset != (unsigned short) sibling_offset) | |
312 | sibling_offset = -1; | |
313 | cur_abbrev->size_if_constant = is_csize ? size : 0; | |
314 | cur_abbrev->sibling_offset = sibling_offset; | |
315 | ||
af0b2a3e | 316 | abbrev_table->add_abbrev (cur_abbrev); |
3054dd54 TT |
317 | } |
318 | ||
319 | return abbrev_table; | |
320 | } |