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8fdd972c TT |
1 | /* DWARF 2 debugging format support for GDB. |
2 | ||
3 | Copyright (C) 1994-2020 Free Software Foundation, Inc. | |
4 | ||
5 | This file is part of GDB. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 3 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
19 | ||
20 | #include "defs.h" | |
0df7ad3a TT |
21 | #include "dwarf2/comp-unit.h" |
22 | #include "dwarf2/leb.h" | |
8fdd972c TT |
23 | #include "dwarf2/line-header.h" |
24 | #include "dwarf2/read.h" | |
25 | #include "complaints.h" | |
26 | #include "filenames.h" | |
27 | ||
28 | void | |
29 | line_header::add_include_dir (const char *include_dir) | |
30 | { | |
31 | if (dwarf_line_debug >= 2) | |
32 | { | |
33 | size_t new_size; | |
34 | if (version >= 5) | |
35 | new_size = m_include_dirs.size (); | |
36 | else | |
37 | new_size = m_include_dirs.size () + 1; | |
38 | fprintf_unfiltered (gdb_stdlog, "Adding dir %zu: %s\n", | |
39 | new_size, include_dir); | |
40 | } | |
41 | m_include_dirs.push_back (include_dir); | |
42 | } | |
43 | ||
44 | void | |
45 | line_header::add_file_name (const char *name, | |
46 | dir_index d_index, | |
47 | unsigned int mod_time, | |
48 | unsigned int length) | |
49 | { | |
50 | if (dwarf_line_debug >= 2) | |
51 | { | |
52 | size_t new_size; | |
53 | if (version >= 5) | |
54 | new_size = file_names_size (); | |
55 | else | |
56 | new_size = file_names_size () + 1; | |
57 | fprintf_unfiltered (gdb_stdlog, "Adding file %zu: %s\n", | |
58 | new_size, name); | |
59 | } | |
60 | m_file_names.emplace_back (name, d_index, mod_time, length); | |
61 | } | |
62 | ||
63 | gdb::unique_xmalloc_ptr<char> | |
8844c11b | 64 | line_header::file_file_name (int file) const |
8fdd972c TT |
65 | { |
66 | /* Is the file number a valid index into the line header's file name | |
67 | table? Remember that file numbers start with one, not zero. */ | |
68 | if (is_valid_file_index (file)) | |
69 | { | |
70 | const file_entry *fe = file_name_at (file); | |
71 | ||
72 | if (!IS_ABSOLUTE_PATH (fe->name)) | |
73 | { | |
74 | const char *dir = fe->include_dir (this); | |
75 | if (dir != NULL) | |
76 | return gdb::unique_xmalloc_ptr<char> (concat (dir, SLASH_STRING, | |
77 | fe->name, | |
78 | (char *) NULL)); | |
79 | } | |
80 | return make_unique_xstrdup (fe->name); | |
81 | } | |
82 | else | |
83 | { | |
84 | /* The compiler produced a bogus file number. We can at least | |
85 | record the macro definitions made in the file, even if we | |
86 | won't be able to find the file by name. */ | |
87 | char fake_name[80]; | |
88 | ||
89 | xsnprintf (fake_name, sizeof (fake_name), | |
90 | "<bad macro file number %d>", file); | |
91 | ||
92 | complaint (_("bad file number in macro information (%d)"), | |
93 | file); | |
94 | ||
95 | return make_unique_xstrdup (fake_name); | |
96 | } | |
97 | } | |
98 | ||
99 | gdb::unique_xmalloc_ptr<char> | |
8844c11b | 100 | line_header::file_full_name (int file, const char *comp_dir) const |
8fdd972c TT |
101 | { |
102 | /* Is the file number a valid index into the line header's file name | |
103 | table? Remember that file numbers start with one, not zero. */ | |
104 | if (is_valid_file_index (file)) | |
105 | { | |
106 | gdb::unique_xmalloc_ptr<char> relative = file_file_name (file); | |
107 | ||
108 | if (IS_ABSOLUTE_PATH (relative.get ()) || comp_dir == NULL) | |
109 | return relative; | |
110 | return gdb::unique_xmalloc_ptr<char> (concat (comp_dir, SLASH_STRING, | |
111 | relative.get (), | |
112 | (char *) NULL)); | |
113 | } | |
114 | else | |
115 | return file_file_name (file); | |
116 | } | |
0df7ad3a TT |
117 | |
118 | static void | |
119 | dwarf2_statement_list_fits_in_line_number_section_complaint (void) | |
120 | { | |
121 | complaint (_("statement list doesn't fit in .debug_line section")); | |
122 | } | |
123 | ||
124 | /* Cover function for read_initial_length. | |
125 | Returns the length of the object at BUF, and stores the size of the | |
126 | initial length in *BYTES_READ and stores the size that offsets will be in | |
127 | *OFFSET_SIZE. | |
128 | If the initial length size is not equivalent to that specified in | |
129 | CU_HEADER then issue a complaint. | |
130 | This is useful when reading non-comp-unit headers. */ | |
131 | ||
132 | static LONGEST | |
133 | read_checked_initial_length_and_offset (bfd *abfd, const gdb_byte *buf, | |
134 | const struct comp_unit_head *cu_header, | |
135 | unsigned int *bytes_read, | |
136 | unsigned int *offset_size) | |
137 | { | |
138 | LONGEST length = read_initial_length (abfd, buf, bytes_read); | |
139 | ||
140 | gdb_assert (cu_header->initial_length_size == 4 | |
141 | || cu_header->initial_length_size == 8 | |
142 | || cu_header->initial_length_size == 12); | |
143 | ||
144 | if (cu_header->initial_length_size != *bytes_read) | |
145 | complaint (_("intermixed 32-bit and 64-bit DWARF sections")); | |
146 | ||
147 | *offset_size = (*bytes_read == 4) ? 4 : 8; | |
148 | return length; | |
149 | } | |
150 | ||
151 | /* Read directory or file name entry format, starting with byte of | |
152 | format count entries, ULEB128 pairs of entry formats, ULEB128 of | |
153 | entries count and the entries themselves in the described entry | |
154 | format. */ | |
155 | ||
156 | static void | |
157 | read_formatted_entries (struct dwarf2_per_objfile *dwarf2_per_objfile, | |
158 | bfd *abfd, const gdb_byte **bufp, | |
159 | struct line_header *lh, | |
160 | const struct comp_unit_head *cu_header, | |
161 | void (*callback) (struct line_header *lh, | |
162 | const char *name, | |
163 | dir_index d_index, | |
164 | unsigned int mod_time, | |
165 | unsigned int length)) | |
166 | { | |
167 | gdb_byte format_count, formati; | |
168 | ULONGEST data_count, datai; | |
169 | const gdb_byte *buf = *bufp; | |
170 | const gdb_byte *format_header_data; | |
171 | unsigned int bytes_read; | |
172 | ||
173 | format_count = read_1_byte (abfd, buf); | |
174 | buf += 1; | |
175 | format_header_data = buf; | |
176 | for (formati = 0; formati < format_count; formati++) | |
177 | { | |
178 | read_unsigned_leb128 (abfd, buf, &bytes_read); | |
179 | buf += bytes_read; | |
180 | read_unsigned_leb128 (abfd, buf, &bytes_read); | |
181 | buf += bytes_read; | |
182 | } | |
183 | ||
184 | data_count = read_unsigned_leb128 (abfd, buf, &bytes_read); | |
185 | buf += bytes_read; | |
186 | for (datai = 0; datai < data_count; datai++) | |
187 | { | |
188 | const gdb_byte *format = format_header_data; | |
189 | struct file_entry fe; | |
190 | ||
191 | for (formati = 0; formati < format_count; formati++) | |
192 | { | |
193 | ULONGEST content_type = read_unsigned_leb128 (abfd, format, &bytes_read); | |
194 | format += bytes_read; | |
195 | ||
196 | ULONGEST form = read_unsigned_leb128 (abfd, format, &bytes_read); | |
197 | format += bytes_read; | |
198 | ||
199 | gdb::optional<const char *> string; | |
200 | gdb::optional<unsigned int> uint; | |
201 | ||
202 | switch (form) | |
203 | { | |
204 | case DW_FORM_string: | |
205 | string.emplace (read_direct_string (abfd, buf, &bytes_read)); | |
206 | buf += bytes_read; | |
207 | break; | |
208 | ||
209 | case DW_FORM_line_strp: | |
210 | string.emplace | |
211 | (dwarf2_per_objfile->read_line_string (buf, | |
212 | cu_header, | |
213 | &bytes_read)); | |
214 | buf += bytes_read; | |
215 | break; | |
216 | ||
217 | case DW_FORM_data1: | |
218 | uint.emplace (read_1_byte (abfd, buf)); | |
219 | buf += 1; | |
220 | break; | |
221 | ||
222 | case DW_FORM_data2: | |
223 | uint.emplace (read_2_bytes (abfd, buf)); | |
224 | buf += 2; | |
225 | break; | |
226 | ||
227 | case DW_FORM_data4: | |
228 | uint.emplace (read_4_bytes (abfd, buf)); | |
229 | buf += 4; | |
230 | break; | |
231 | ||
232 | case DW_FORM_data8: | |
233 | uint.emplace (read_8_bytes (abfd, buf)); | |
234 | buf += 8; | |
235 | break; | |
236 | ||
237 | case DW_FORM_data16: | |
238 | /* This is used for MD5, but file_entry does not record MD5s. */ | |
239 | buf += 16; | |
240 | break; | |
241 | ||
242 | case DW_FORM_udata: | |
243 | uint.emplace (read_unsigned_leb128 (abfd, buf, &bytes_read)); | |
244 | buf += bytes_read; | |
245 | break; | |
246 | ||
247 | case DW_FORM_block: | |
248 | /* It is valid only for DW_LNCT_timestamp which is ignored by | |
249 | current GDB. */ | |
250 | break; | |
251 | } | |
252 | ||
253 | switch (content_type) | |
254 | { | |
255 | case DW_LNCT_path: | |
256 | if (string.has_value ()) | |
257 | fe.name = *string; | |
258 | break; | |
259 | case DW_LNCT_directory_index: | |
260 | if (uint.has_value ()) | |
261 | fe.d_index = (dir_index) *uint; | |
262 | break; | |
263 | case DW_LNCT_timestamp: | |
264 | if (uint.has_value ()) | |
265 | fe.mod_time = *uint; | |
266 | break; | |
267 | case DW_LNCT_size: | |
268 | if (uint.has_value ()) | |
269 | fe.length = *uint; | |
270 | break; | |
271 | case DW_LNCT_MD5: | |
272 | break; | |
273 | default: | |
274 | complaint (_("Unknown format content type %s"), | |
275 | pulongest (content_type)); | |
276 | } | |
277 | } | |
278 | ||
279 | callback (lh, fe.name, fe.d_index, fe.mod_time, fe.length); | |
280 | } | |
281 | ||
282 | *bufp = buf; | |
283 | } | |
284 | ||
285 | /* See line-header.h. */ | |
286 | ||
287 | line_header_up | |
288 | dwarf_decode_line_header (sect_offset sect_off, bool is_dwz, | |
289 | struct dwarf2_per_objfile *dwarf2_per_objfile, | |
290 | struct dwarf2_section_info *section, | |
291 | const struct comp_unit_head *cu_header) | |
292 | { | |
293 | const gdb_byte *line_ptr; | |
294 | unsigned int bytes_read, offset_size; | |
295 | int i; | |
296 | const char *cur_dir, *cur_file; | |
297 | ||
298 | bfd *abfd = section->get_bfd_owner (); | |
299 | ||
300 | /* Make sure that at least there's room for the total_length field. | |
301 | That could be 12 bytes long, but we're just going to fudge that. */ | |
302 | if (to_underlying (sect_off) + 4 >= section->size) | |
303 | { | |
304 | dwarf2_statement_list_fits_in_line_number_section_complaint (); | |
305 | return 0; | |
306 | } | |
307 | ||
308 | line_header_up lh (new line_header ()); | |
309 | ||
310 | lh->sect_off = sect_off; | |
311 | lh->offset_in_dwz = is_dwz; | |
312 | ||
313 | line_ptr = section->buffer + to_underlying (sect_off); | |
314 | ||
315 | /* Read in the header. */ | |
316 | lh->total_length = | |
317 | read_checked_initial_length_and_offset (abfd, line_ptr, cu_header, | |
318 | &bytes_read, &offset_size); | |
319 | line_ptr += bytes_read; | |
320 | ||
321 | const gdb_byte *start_here = line_ptr; | |
322 | ||
323 | if (line_ptr + lh->total_length > (section->buffer + section->size)) | |
324 | { | |
325 | dwarf2_statement_list_fits_in_line_number_section_complaint (); | |
326 | return 0; | |
327 | } | |
328 | lh->statement_program_end = start_here + lh->total_length; | |
329 | lh->version = read_2_bytes (abfd, line_ptr); | |
330 | line_ptr += 2; | |
331 | if (lh->version > 5) | |
332 | { | |
333 | /* This is a version we don't understand. The format could have | |
334 | changed in ways we don't handle properly so just punt. */ | |
335 | complaint (_("unsupported version in .debug_line section")); | |
336 | return NULL; | |
337 | } | |
338 | if (lh->version >= 5) | |
339 | { | |
340 | gdb_byte segment_selector_size; | |
341 | ||
342 | /* Skip address size. */ | |
343 | read_1_byte (abfd, line_ptr); | |
344 | line_ptr += 1; | |
345 | ||
346 | segment_selector_size = read_1_byte (abfd, line_ptr); | |
347 | line_ptr += 1; | |
348 | if (segment_selector_size != 0) | |
349 | { | |
350 | complaint (_("unsupported segment selector size %u " | |
351 | "in .debug_line section"), | |
352 | segment_selector_size); | |
353 | return NULL; | |
354 | } | |
355 | } | |
356 | lh->header_length = read_offset (abfd, line_ptr, offset_size); | |
357 | line_ptr += offset_size; | |
358 | lh->statement_program_start = line_ptr + lh->header_length; | |
359 | lh->minimum_instruction_length = read_1_byte (abfd, line_ptr); | |
360 | line_ptr += 1; | |
361 | if (lh->version >= 4) | |
362 | { | |
363 | lh->maximum_ops_per_instruction = read_1_byte (abfd, line_ptr); | |
364 | line_ptr += 1; | |
365 | } | |
366 | else | |
367 | lh->maximum_ops_per_instruction = 1; | |
368 | ||
369 | if (lh->maximum_ops_per_instruction == 0) | |
370 | { | |
371 | lh->maximum_ops_per_instruction = 1; | |
372 | complaint (_("invalid maximum_ops_per_instruction " | |
373 | "in `.debug_line' section")); | |
374 | } | |
375 | ||
376 | lh->default_is_stmt = read_1_byte (abfd, line_ptr); | |
377 | line_ptr += 1; | |
378 | lh->line_base = read_1_signed_byte (abfd, line_ptr); | |
379 | line_ptr += 1; | |
380 | lh->line_range = read_1_byte (abfd, line_ptr); | |
381 | line_ptr += 1; | |
382 | lh->opcode_base = read_1_byte (abfd, line_ptr); | |
383 | line_ptr += 1; | |
384 | lh->standard_opcode_lengths.reset (new unsigned char[lh->opcode_base]); | |
385 | ||
386 | lh->standard_opcode_lengths[0] = 1; /* This should never be used anyway. */ | |
387 | for (i = 1; i < lh->opcode_base; ++i) | |
388 | { | |
389 | lh->standard_opcode_lengths[i] = read_1_byte (abfd, line_ptr); | |
390 | line_ptr += 1; | |
391 | } | |
392 | ||
393 | if (lh->version >= 5) | |
394 | { | |
395 | /* Read directory table. */ | |
396 | read_formatted_entries (dwarf2_per_objfile, abfd, &line_ptr, lh.get (), | |
397 | cu_header, | |
398 | [] (struct line_header *header, const char *name, | |
399 | dir_index d_index, unsigned int mod_time, | |
400 | unsigned int length) | |
401 | { | |
402 | header->add_include_dir (name); | |
403 | }); | |
404 | ||
405 | /* Read file name table. */ | |
406 | read_formatted_entries (dwarf2_per_objfile, abfd, &line_ptr, lh.get (), | |
407 | cu_header, | |
408 | [] (struct line_header *header, const char *name, | |
409 | dir_index d_index, unsigned int mod_time, | |
410 | unsigned int length) | |
411 | { | |
412 | header->add_file_name (name, d_index, mod_time, length); | |
413 | }); | |
414 | } | |
415 | else | |
416 | { | |
417 | /* Read directory table. */ | |
418 | while ((cur_dir = read_direct_string (abfd, line_ptr, &bytes_read)) != NULL) | |
419 | { | |
420 | line_ptr += bytes_read; | |
421 | lh->add_include_dir (cur_dir); | |
422 | } | |
423 | line_ptr += bytes_read; | |
424 | ||
425 | /* Read file name table. */ | |
426 | while ((cur_file = read_direct_string (abfd, line_ptr, &bytes_read)) != NULL) | |
427 | { | |
428 | unsigned int mod_time, length; | |
429 | dir_index d_index; | |
430 | ||
431 | line_ptr += bytes_read; | |
432 | d_index = (dir_index) read_unsigned_leb128 (abfd, line_ptr, &bytes_read); | |
433 | line_ptr += bytes_read; | |
434 | mod_time = read_unsigned_leb128 (abfd, line_ptr, &bytes_read); | |
435 | line_ptr += bytes_read; | |
436 | length = read_unsigned_leb128 (abfd, line_ptr, &bytes_read); | |
437 | line_ptr += bytes_read; | |
438 | ||
439 | lh->add_file_name (cur_file, d_index, mod_time, length); | |
440 | } | |
441 | line_ptr += bytes_read; | |
442 | } | |
443 | ||
444 | if (line_ptr > (section->buffer + section->size)) | |
445 | complaint (_("line number info header doesn't " | |
446 | "fit in `.debug_line' section")); | |
447 | ||
448 | return lh; | |
449 | } |