| 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" |
| 21 | #include "dwarf2/comp-unit.h" |
| 22 | #include "dwarf2/leb.h" |
| 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> |
| 64 | line_header::file_file_name (int file) const |
| 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> |
| 100 | line_header::file_full_name (int file, const char *comp_dir) const |
| 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 | } |
| 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 (dwarf2_per_objfile *per_objfile, bfd *abfd, |
| 158 | const gdb_byte **bufp, struct line_header *lh, |
| 159 | const struct comp_unit_head *cu_header, |
| 160 | void (*callback) (struct line_header *lh, |
| 161 | const char *name, |
| 162 | dir_index d_index, |
| 163 | unsigned int mod_time, |
| 164 | unsigned int length)) |
| 165 | { |
| 166 | gdb_byte format_count, formati; |
| 167 | ULONGEST data_count, datai; |
| 168 | const gdb_byte *buf = *bufp; |
| 169 | const gdb_byte *format_header_data; |
| 170 | unsigned int bytes_read; |
| 171 | |
| 172 | format_count = read_1_byte (abfd, buf); |
| 173 | buf += 1; |
| 174 | format_header_data = buf; |
| 175 | for (formati = 0; formati < format_count; formati++) |
| 176 | { |
| 177 | read_unsigned_leb128 (abfd, buf, &bytes_read); |
| 178 | buf += bytes_read; |
| 179 | read_unsigned_leb128 (abfd, buf, &bytes_read); |
| 180 | buf += bytes_read; |
| 181 | } |
| 182 | |
| 183 | data_count = read_unsigned_leb128 (abfd, buf, &bytes_read); |
| 184 | buf += bytes_read; |
| 185 | for (datai = 0; datai < data_count; datai++) |
| 186 | { |
| 187 | const gdb_byte *format = format_header_data; |
| 188 | struct file_entry fe; |
| 189 | |
| 190 | for (formati = 0; formati < format_count; formati++) |
| 191 | { |
| 192 | ULONGEST content_type = read_unsigned_leb128 (abfd, format, &bytes_read); |
| 193 | format += bytes_read; |
| 194 | |
| 195 | ULONGEST form = read_unsigned_leb128 (abfd, format, &bytes_read); |
| 196 | format += bytes_read; |
| 197 | |
| 198 | gdb::optional<const char *> string; |
| 199 | gdb::optional<unsigned int> uint; |
| 200 | |
| 201 | switch (form) |
| 202 | { |
| 203 | case DW_FORM_string: |
| 204 | string.emplace (read_direct_string (abfd, buf, &bytes_read)); |
| 205 | buf += bytes_read; |
| 206 | break; |
| 207 | |
| 208 | case DW_FORM_line_strp: |
| 209 | string.emplace |
| 210 | (per_objfile->read_line_string (buf, cu_header, &bytes_read)); |
| 211 | buf += bytes_read; |
| 212 | break; |
| 213 | |
| 214 | case DW_FORM_data1: |
| 215 | uint.emplace (read_1_byte (abfd, buf)); |
| 216 | buf += 1; |
| 217 | break; |
| 218 | |
| 219 | case DW_FORM_data2: |
| 220 | uint.emplace (read_2_bytes (abfd, buf)); |
| 221 | buf += 2; |
| 222 | break; |
| 223 | |
| 224 | case DW_FORM_data4: |
| 225 | uint.emplace (read_4_bytes (abfd, buf)); |
| 226 | buf += 4; |
| 227 | break; |
| 228 | |
| 229 | case DW_FORM_data8: |
| 230 | uint.emplace (read_8_bytes (abfd, buf)); |
| 231 | buf += 8; |
| 232 | break; |
| 233 | |
| 234 | case DW_FORM_data16: |
| 235 | /* This is used for MD5, but file_entry does not record MD5s. */ |
| 236 | buf += 16; |
| 237 | break; |
| 238 | |
| 239 | case DW_FORM_udata: |
| 240 | uint.emplace (read_unsigned_leb128 (abfd, buf, &bytes_read)); |
| 241 | buf += bytes_read; |
| 242 | break; |
| 243 | |
| 244 | case DW_FORM_block: |
| 245 | /* It is valid only for DW_LNCT_timestamp which is ignored by |
| 246 | current GDB. */ |
| 247 | break; |
| 248 | } |
| 249 | |
| 250 | switch (content_type) |
| 251 | { |
| 252 | case DW_LNCT_path: |
| 253 | if (string.has_value ()) |
| 254 | fe.name = *string; |
| 255 | break; |
| 256 | case DW_LNCT_directory_index: |
| 257 | if (uint.has_value ()) |
| 258 | fe.d_index = (dir_index) *uint; |
| 259 | break; |
| 260 | case DW_LNCT_timestamp: |
| 261 | if (uint.has_value ()) |
| 262 | fe.mod_time = *uint; |
| 263 | break; |
| 264 | case DW_LNCT_size: |
| 265 | if (uint.has_value ()) |
| 266 | fe.length = *uint; |
| 267 | break; |
| 268 | case DW_LNCT_MD5: |
| 269 | break; |
| 270 | default: |
| 271 | complaint (_("Unknown format content type %s"), |
| 272 | pulongest (content_type)); |
| 273 | } |
| 274 | } |
| 275 | |
| 276 | callback (lh, fe.name, fe.d_index, fe.mod_time, fe.length); |
| 277 | } |
| 278 | |
| 279 | *bufp = buf; |
| 280 | } |
| 281 | |
| 282 | /* See line-header.h. */ |
| 283 | |
| 284 | line_header_up |
| 285 | dwarf_decode_line_header (sect_offset sect_off, bool is_dwz, |
| 286 | dwarf2_per_objfile *per_objfile, |
| 287 | struct dwarf2_section_info *section, |
| 288 | const struct comp_unit_head *cu_header) |
| 289 | { |
| 290 | const gdb_byte *line_ptr; |
| 291 | unsigned int bytes_read, offset_size; |
| 292 | int i; |
| 293 | const char *cur_dir, *cur_file; |
| 294 | |
| 295 | bfd *abfd = section->get_bfd_owner (); |
| 296 | |
| 297 | /* Make sure that at least there's room for the total_length field. |
| 298 | That could be 12 bytes long, but we're just going to fudge that. */ |
| 299 | if (to_underlying (sect_off) + 4 >= section->size) |
| 300 | { |
| 301 | dwarf2_statement_list_fits_in_line_number_section_complaint (); |
| 302 | return 0; |
| 303 | } |
| 304 | |
| 305 | line_header_up lh (new line_header ()); |
| 306 | |
| 307 | lh->sect_off = sect_off; |
| 308 | lh->offset_in_dwz = is_dwz; |
| 309 | |
| 310 | line_ptr = section->buffer + to_underlying (sect_off); |
| 311 | |
| 312 | /* Read in the header. */ |
| 313 | lh->total_length = |
| 314 | read_checked_initial_length_and_offset (abfd, line_ptr, cu_header, |
| 315 | &bytes_read, &offset_size); |
| 316 | line_ptr += bytes_read; |
| 317 | |
| 318 | const gdb_byte *start_here = line_ptr; |
| 319 | |
| 320 | if (line_ptr + lh->total_length > (section->buffer + section->size)) |
| 321 | { |
| 322 | dwarf2_statement_list_fits_in_line_number_section_complaint (); |
| 323 | return 0; |
| 324 | } |
| 325 | lh->statement_program_end = start_here + lh->total_length; |
| 326 | lh->version = read_2_bytes (abfd, line_ptr); |
| 327 | line_ptr += 2; |
| 328 | if (lh->version > 5) |
| 329 | { |
| 330 | /* This is a version we don't understand. The format could have |
| 331 | changed in ways we don't handle properly so just punt. */ |
| 332 | complaint (_("unsupported version in .debug_line section")); |
| 333 | return NULL; |
| 334 | } |
| 335 | if (lh->version >= 5) |
| 336 | { |
| 337 | gdb_byte segment_selector_size; |
| 338 | |
| 339 | /* Skip address size. */ |
| 340 | read_1_byte (abfd, line_ptr); |
| 341 | line_ptr += 1; |
| 342 | |
| 343 | segment_selector_size = read_1_byte (abfd, line_ptr); |
| 344 | line_ptr += 1; |
| 345 | if (segment_selector_size != 0) |
| 346 | { |
| 347 | complaint (_("unsupported segment selector size %u " |
| 348 | "in .debug_line section"), |
| 349 | segment_selector_size); |
| 350 | return NULL; |
| 351 | } |
| 352 | } |
| 353 | lh->header_length = read_offset (abfd, line_ptr, offset_size); |
| 354 | line_ptr += offset_size; |
| 355 | lh->statement_program_start = line_ptr + lh->header_length; |
| 356 | lh->minimum_instruction_length = read_1_byte (abfd, line_ptr); |
| 357 | line_ptr += 1; |
| 358 | if (lh->version >= 4) |
| 359 | { |
| 360 | lh->maximum_ops_per_instruction = read_1_byte (abfd, line_ptr); |
| 361 | line_ptr += 1; |
| 362 | } |
| 363 | else |
| 364 | lh->maximum_ops_per_instruction = 1; |
| 365 | |
| 366 | if (lh->maximum_ops_per_instruction == 0) |
| 367 | { |
| 368 | lh->maximum_ops_per_instruction = 1; |
| 369 | complaint (_("invalid maximum_ops_per_instruction " |
| 370 | "in `.debug_line' section")); |
| 371 | } |
| 372 | |
| 373 | lh->default_is_stmt = read_1_byte (abfd, line_ptr); |
| 374 | line_ptr += 1; |
| 375 | lh->line_base = read_1_signed_byte (abfd, line_ptr); |
| 376 | line_ptr += 1; |
| 377 | lh->line_range = read_1_byte (abfd, line_ptr); |
| 378 | line_ptr += 1; |
| 379 | lh->opcode_base = read_1_byte (abfd, line_ptr); |
| 380 | line_ptr += 1; |
| 381 | lh->standard_opcode_lengths.reset (new unsigned char[lh->opcode_base]); |
| 382 | |
| 383 | lh->standard_opcode_lengths[0] = 1; /* This should never be used anyway. */ |
| 384 | for (i = 1; i < lh->opcode_base; ++i) |
| 385 | { |
| 386 | lh->standard_opcode_lengths[i] = read_1_byte (abfd, line_ptr); |
| 387 | line_ptr += 1; |
| 388 | } |
| 389 | |
| 390 | if (lh->version >= 5) |
| 391 | { |
| 392 | /* Read directory table. */ |
| 393 | read_formatted_entries (per_objfile, abfd, &line_ptr, lh.get (), |
| 394 | cu_header, |
| 395 | [] (struct line_header *header, const char *name, |
| 396 | dir_index d_index, unsigned int mod_time, |
| 397 | unsigned int length) |
| 398 | { |
| 399 | header->add_include_dir (name); |
| 400 | }); |
| 401 | |
| 402 | /* Read file name table. */ |
| 403 | read_formatted_entries (per_objfile, abfd, &line_ptr, lh.get (), |
| 404 | cu_header, |
| 405 | [] (struct line_header *header, const char *name, |
| 406 | dir_index d_index, unsigned int mod_time, |
| 407 | unsigned int length) |
| 408 | { |
| 409 | header->add_file_name (name, d_index, mod_time, length); |
| 410 | }); |
| 411 | } |
| 412 | else |
| 413 | { |
| 414 | /* Read directory table. */ |
| 415 | while ((cur_dir = read_direct_string (abfd, line_ptr, &bytes_read)) != NULL) |
| 416 | { |
| 417 | line_ptr += bytes_read; |
| 418 | lh->add_include_dir (cur_dir); |
| 419 | } |
| 420 | line_ptr += bytes_read; |
| 421 | |
| 422 | /* Read file name table. */ |
| 423 | while ((cur_file = read_direct_string (abfd, line_ptr, &bytes_read)) != NULL) |
| 424 | { |
| 425 | unsigned int mod_time, length; |
| 426 | dir_index d_index; |
| 427 | |
| 428 | line_ptr += bytes_read; |
| 429 | d_index = (dir_index) read_unsigned_leb128 (abfd, line_ptr, &bytes_read); |
| 430 | line_ptr += bytes_read; |
| 431 | mod_time = read_unsigned_leb128 (abfd, line_ptr, &bytes_read); |
| 432 | line_ptr += bytes_read; |
| 433 | length = read_unsigned_leb128 (abfd, line_ptr, &bytes_read); |
| 434 | line_ptr += bytes_read; |
| 435 | |
| 436 | lh->add_file_name (cur_file, d_index, mod_time, length); |
| 437 | } |
| 438 | line_ptr += bytes_read; |
| 439 | } |
| 440 | |
| 441 | if (line_ptr > (section->buffer + section->size)) |
| 442 | complaint (_("line number info header doesn't " |
| 443 | "fit in `.debug_line' section")); |
| 444 | |
| 445 | return lh; |
| 446 | } |