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bae7f79e ILT |
1 | // fileread.h -- read files for gold -*- C++ -*- |
2 | ||
ebdbb458 | 3 | // Copyright 2006, 2007, 2008 Free Software Foundation, Inc. |
6cb15b7f ILT |
4 | // Written by Ian Lance Taylor <iant@google.com>. |
5 | ||
6 | // This file is part of gold. | |
7 | ||
8 | // This program is free software; you can redistribute it and/or modify | |
9 | // it under the terms of the GNU General Public License as published by | |
10 | // the Free Software Foundation; either version 3 of the License, or | |
11 | // (at your option) any later version. | |
12 | ||
13 | // This program is distributed in the hope that it will be useful, | |
14 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | // GNU General Public License for more details. | |
17 | ||
18 | // You should have received a copy of the GNU General Public License | |
19 | // along with this program; if not, write to the Free Software | |
20 | // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, | |
21 | // MA 02110-1301, USA. | |
22 | ||
bae7f79e ILT |
23 | // Classes used to read data from binary input files. |
24 | ||
25 | #ifndef GOLD_FILEREAD_H | |
26 | #define GOLD_FILEREAD_H | |
27 | ||
bae7f79e | 28 | #include <list> |
ead1e424 ILT |
29 | #include <map> |
30 | #include <string> | |
0c0a7411 | 31 | #include <vector> |
bae7f79e | 32 | |
17a1d0a9 | 33 | #include "token.h" |
bae7f79e ILT |
34 | |
35 | namespace gold | |
36 | { | |
37 | ||
14144f39 ILT |
38 | class Position_dependent_options; |
39 | class Input_file_argument; | |
bae7f79e | 40 | class Dirsearch; |
bae7f79e ILT |
41 | class File_view; |
42 | ||
43 | // File_read manages a file descriptor for a file we are reading. We | |
44 | // close file descriptors if we run out of them, so this class reopens | |
45 | // the file as needed. | |
46 | ||
47 | class File_read | |
48 | { | |
49 | public: | |
50 | File_read() | |
cb295612 ILT |
51 | : name_(), descriptor_(-1), object_count_(0), size_(0), token_(false), |
52 | views_(), saved_views_(), contents_(NULL), mapped_bytes_(0), | |
53 | released_(true) | |
bae7f79e | 54 | { } |
5a6f7e2d | 55 | |
bae7f79e ILT |
56 | ~File_read(); |
57 | ||
58 | // Open a file. | |
59 | bool | |
17a1d0a9 | 60 | open(const Task*, const std::string& name); |
bae7f79e | 61 | |
5a6f7e2d ILT |
62 | // Pretend to open the file, but provide the file contents. No |
63 | // actual file system activity will occur. This is used for | |
64 | // testing. | |
65 | bool | |
17a1d0a9 ILT |
66 | open(const Task*, const std::string& name, const unsigned char* contents, |
67 | off_t size); | |
5a6f7e2d | 68 | |
bae7f79e ILT |
69 | // Return the file name. |
70 | const std::string& | |
71 | filename() const | |
72 | { return this->name_; } | |
73 | ||
cb295612 ILT |
74 | // Add an object associated with a file. |
75 | void | |
76 | add_object() | |
77 | { ++this->object_count_; } | |
78 | ||
79 | // Remove an object associated with a file. | |
80 | void | |
81 | remove_object() | |
82 | { --this->object_count_; } | |
83 | ||
17a1d0a9 ILT |
84 | // Lock the file for exclusive access within a particular Task::run |
85 | // execution. This means that the descriptor can not be closed. | |
86 | // This routine may only be called when the workqueue lock is held. | |
bae7f79e | 87 | void |
17a1d0a9 | 88 | lock(const Task* t); |
bae7f79e ILT |
89 | |
90 | // Unlock the descriptor, permitting it to be closed if necessary. | |
91 | void | |
17a1d0a9 | 92 | unlock(const Task* t); |
4973341a | 93 | |
bae7f79e ILT |
94 | // Test whether the object is locked. |
95 | bool | |
7004837e | 96 | is_locked() const; |
bae7f79e | 97 | |
17a1d0a9 ILT |
98 | // Return the token, so that the task can be queued. |
99 | Task_token* | |
100 | token() | |
101 | { return &this->token_; } | |
102 | ||
103 | // Release the file. This indicates that we aren't going to do | |
104 | // anything further with it until it is unlocked. This is used | |
105 | // because a Task which locks the file never calls either lock or | |
106 | // unlock; it just locks the token. The basic rule is that a Task | |
107 | // which locks a file via the Task::locks interface must explicitly | |
108 | // call release() when it is done. This is not necessary for code | |
109 | // which calls unlock() on the file. | |
110 | void | |
111 | release(); | |
112 | ||
82dcae9d ILT |
113 | // Return the size of the file. |
114 | off_t | |
115 | filesize() const | |
116 | { return this->size_; } | |
117 | ||
ba45d247 | 118 | // Return a view into the file starting at file offset START for |
39d0cb0e ILT |
119 | // SIZE bytes. OFFSET is the offset into the input file for the |
120 | // file we are reading; this is zero for a normal object file, | |
121 | // non-zero for an object file in an archive. ALIGNED is true if | |
122 | // the data must be naturally aligned; this only matters when OFFSET | |
123 | // is not zero. The pointer will remain valid until the File_read | |
124 | // is unlocked. It is an error if we can not read enough data from | |
125 | // the file. The CACHE parameter is a hint as to whether it will be | |
9eb9fa57 ILT |
126 | // useful to cache this data for later accesses--i.e., later calls |
127 | // to get_view, read, or get_lasting_view which retrieve the same | |
128 | // data. | |
bae7f79e | 129 | const unsigned char* |
39d0cb0e ILT |
130 | get_view(off_t offset, off_t start, section_size_type size, bool aligned, |
131 | bool cache); | |
bae7f79e | 132 | |
ba45d247 ILT |
133 | // Read data from the file into the buffer P starting at file offset |
134 | // START for SIZE bytes. | |
135 | void | |
fe8718a4 | 136 | read(off_t start, section_size_type size, void* p) const; |
ba45d247 | 137 | |
ba45d247 ILT |
138 | // Return a lasting view into the file starting at file offset START |
139 | // for SIZE bytes. This is allocated with new, and the caller is | |
140 | // responsible for deleting it when done. The data associated with | |
141 | // this view will remain valid until the view is deleted. It is an | |
39d0cb0e ILT |
142 | // error if we can not read enough data from the file. The OFFSET, |
143 | // ALIGNED and CACHE parameters are as in get_view. | |
bae7f79e | 144 | File_view* |
39d0cb0e ILT |
145 | get_lasting_view(off_t offset, off_t start, section_size_type size, |
146 | bool aligned, bool cache); | |
bae7f79e | 147 | |
cb295612 ILT |
148 | // Mark all views as no longer cached. |
149 | void | |
150 | clear_view_cache_marks(); | |
151 | ||
39d0cb0e ILT |
152 | // Discard all uncached views. This is normally done by release(), |
153 | // but not for objects in archives. FIXME: This is a complicated | |
154 | // interface, and it would be nice to have something more automatic. | |
155 | void | |
156 | clear_uncached_views() | |
157 | { this->clear_views(false); } | |
158 | ||
cb295612 ILT |
159 | // A struct used to do a multiple read. |
160 | struct Read_multiple_entry | |
161 | { | |
162 | // The file offset of the data to read. | |
163 | off_t file_offset; | |
164 | // The amount of data to read. | |
165 | section_size_type size; | |
166 | // The buffer where the data should be placed. | |
167 | unsigned char* buffer; | |
168 | ||
169 | Read_multiple_entry(off_t o, section_size_type s, unsigned char* b) | |
170 | : file_offset(o), size(s), buffer(b) | |
171 | { } | |
172 | }; | |
173 | ||
174 | typedef std::vector<Read_multiple_entry> Read_multiple; | |
175 | ||
176 | // Read a bunch of data from the file into various different | |
177 | // locations. The vector must be sorted by ascending file_offset. | |
178 | // BASE is a base offset to be added to all the offsets in the | |
179 | // vector. | |
180 | void | |
181 | read_multiple(off_t base, const Read_multiple&); | |
182 | ||
e44fcf3b ILT |
183 | // Dump statistical information to stderr. |
184 | static void | |
185 | print_stats(); | |
186 | ||
bae7f79e ILT |
187 | private: |
188 | // This class may not be copied. | |
189 | File_read(const File_read&); | |
190 | File_read& operator=(const File_read&); | |
191 | ||
17a1d0a9 ILT |
192 | // Total bytes mapped into memory during the link. This variable |
193 | // may not be accurate when running multi-threaded. | |
e44fcf3b ILT |
194 | static unsigned long long total_mapped_bytes; |
195 | ||
196 | // Current number of bytes mapped into memory during the link. This | |
17a1d0a9 | 197 | // variable may not be accurate when running multi-threaded. |
e44fcf3b ILT |
198 | static unsigned long long current_mapped_bytes; |
199 | ||
200 | // High water mark of bytes mapped into memory during the link. | |
17a1d0a9 | 201 | // This variable may not be accurate when running multi-threaded. |
e44fcf3b ILT |
202 | static unsigned long long maximum_mapped_bytes; |
203 | ||
d1038c21 | 204 | // A view into the file. |
bae7f79e ILT |
205 | class View |
206 | { | |
207 | public: | |
8383303e | 208 | View(off_t start, section_size_type size, const unsigned char* data, |
39d0cb0e | 209 | unsigned int byteshift, bool cache, bool mapped) |
9eb9fa57 | 210 | : start_(start), size_(size), data_(data), lock_count_(0), |
39d0cb0e | 211 | byteshift_(byteshift), cache_(cache), mapped_(mapped), accessed_(true) |
bae7f79e ILT |
212 | { } |
213 | ||
214 | ~View(); | |
215 | ||
216 | off_t | |
217 | start() const | |
218 | { return this->start_; } | |
219 | ||
8383303e | 220 | section_size_type |
bae7f79e ILT |
221 | size() const |
222 | { return this->size_; } | |
223 | ||
e214a02b | 224 | const unsigned char* |
bae7f79e ILT |
225 | data() const |
226 | { return this->data_; } | |
227 | ||
228 | void | |
229 | lock(); | |
230 | ||
231 | void | |
232 | unlock(); | |
233 | ||
234 | bool | |
235 | is_locked(); | |
236 | ||
39d0cb0e ILT |
237 | unsigned int |
238 | byteshift() const | |
239 | { return this->byteshift_; } | |
240 | ||
9eb9fa57 ILT |
241 | void |
242 | set_cache() | |
243 | { this->cache_ = true; } | |
244 | ||
cb295612 ILT |
245 | void |
246 | clear_cache() | |
247 | { this->cache_ = false; } | |
248 | ||
9eb9fa57 ILT |
249 | bool |
250 | should_cache() const | |
251 | { return this->cache_; } | |
252 | ||
cb295612 ILT |
253 | void |
254 | set_accessed() | |
255 | { this->accessed_ = true; } | |
256 | ||
257 | void | |
258 | clear_accessed() | |
259 | { this->accessed_= false; } | |
260 | ||
261 | bool | |
262 | accessed() const | |
263 | { return this->accessed_; } | |
264 | ||
bae7f79e ILT |
265 | private: |
266 | View(const View&); | |
267 | View& operator=(const View&); | |
268 | ||
39d0cb0e | 269 | // The file offset of the start of the view. |
bae7f79e | 270 | off_t start_; |
39d0cb0e | 271 | // The size of the view. |
8383303e | 272 | section_size_type size_; |
39d0cb0e | 273 | // A pointer to the actual bytes. |
e214a02b | 274 | const unsigned char* data_; |
39d0cb0e | 275 | // The number of locks on this view. |
bae7f79e | 276 | int lock_count_; |
39d0cb0e ILT |
277 | // The number of bytes that the view is shifted relative to the |
278 | // underlying file. This is used to align data. This is normally | |
279 | // zero, except possibly for an object in an archive. | |
280 | unsigned int byteshift_; | |
281 | // Whether the view is cached. | |
9eb9fa57 | 282 | bool cache_; |
39d0cb0e ILT |
283 | // Whether the view is mapped into memory. If not, data_ points |
284 | // to memory allocated using new[]. | |
d1038c21 | 285 | bool mapped_; |
39d0cb0e | 286 | // Whether the view has been accessed recently. |
cb295612 | 287 | bool accessed_; |
bae7f79e ILT |
288 | }; |
289 | ||
e44fcf3b | 290 | friend class View; |
bae7f79e ILT |
291 | friend class File_view; |
292 | ||
39d0cb0e ILT |
293 | // The type of a mapping from page start and byte shift to views. |
294 | typedef std::map<std::pair<off_t, unsigned int>, View*> Views; | |
295 | ||
296 | // A simple list of Views. | |
297 | typedef std::list<View*> Saved_views; | |
298 | ||
ead1e424 | 299 | // Find a view into the file. |
bae7f79e | 300 | View* |
39d0cb0e ILT |
301 | find_view(off_t start, section_size_type size, unsigned int byteshift, |
302 | View** vshifted) const; | |
bae7f79e | 303 | |
ead1e424 | 304 | // Read data from the file into a buffer. |
82dcae9d | 305 | void |
fe8718a4 | 306 | do_read(off_t start, section_size_type size, void* p) const; |
bae7f79e | 307 | |
39d0cb0e ILT |
308 | // Add a view. |
309 | void | |
310 | add_view(View*); | |
311 | ||
312 | // Make a view into the file. | |
313 | View* | |
314 | make_view(off_t start, section_size_type size, unsigned int byteshift, | |
315 | bool cache); | |
316 | ||
ead1e424 | 317 | // Find or make a view into the file. |
bae7f79e | 318 | View* |
39d0cb0e ILT |
319 | find_or_make_view(off_t offset, off_t start, section_size_type size, |
320 | bool aligned, bool cache); | |
bae7f79e | 321 | |
ead1e424 | 322 | // Clear the file views. |
bae7f79e ILT |
323 | void |
324 | clear_views(bool); | |
325 | ||
ead1e424 ILT |
326 | // The size of a file page for buffering data. |
327 | static const off_t page_size = 8192; | |
328 | ||
329 | // Given a file offset, return the page offset. | |
330 | static off_t | |
331 | page_offset(off_t file_offset) | |
332 | { return file_offset & ~ (page_size - 1); } | |
333 | ||
334 | // Given a file size, return the size to read integral pages. | |
335 | static off_t | |
336 | pages(off_t file_size) | |
337 | { return (file_size + (page_size - 1)) & ~ (page_size - 1); } | |
338 | ||
cb295612 ILT |
339 | // The maximum number of entries we will pass to ::readv. |
340 | static const size_t max_readv_entries = 128; | |
341 | ||
342 | // Use readv to read data. | |
343 | void | |
344 | do_readv(off_t base, const Read_multiple&, size_t start, size_t count); | |
345 | ||
ead1e424 | 346 | // File name. |
bae7f79e | 347 | std::string name_; |
ead1e424 | 348 | // File descriptor. |
bae7f79e | 349 | int descriptor_; |
cb295612 ILT |
350 | // The number of objects associated with this file. This will be |
351 | // more than 1 in the case of an archive. | |
352 | int object_count_; | |
82dcae9d ILT |
353 | // File size. |
354 | off_t size_; | |
17a1d0a9 ILT |
355 | // A token used to lock the file. |
356 | Task_token token_; | |
ead1e424 ILT |
357 | // Buffered views into the file. |
358 | Views views_; | |
359 | // List of views which were locked but had to be removed from views_ | |
360 | // because they were not large enough. | |
361 | Saved_views saved_views_; | |
5a6f7e2d ILT |
362 | // Specified file contents. Used only for testing purposes. |
363 | const unsigned char* contents_; | |
e44fcf3b ILT |
364 | // Total amount of space mapped into memory. This is only changed |
365 | // while the file is locked. When we unlock the file, we transfer | |
366 | // the total to total_mapped_bytes, and reset this to zero. | |
367 | size_t mapped_bytes_; | |
17a1d0a9 ILT |
368 | // Whether the file was released. |
369 | bool released_; | |
bae7f79e ILT |
370 | }; |
371 | ||
372 | // A view of file data that persists even when the file is unlocked. | |
373 | // Callers should destroy these when no longer required. These are | |
374 | // obtained form File_read::get_lasting_view. They may only be | |
375 | // destroyed when the underlying File_read is locked. | |
376 | ||
377 | class File_view | |
378 | { | |
379 | public: | |
380 | // This may only be called when the underlying File_read is locked. | |
381 | ~File_view(); | |
382 | ||
383 | // Return a pointer to the data associated with this view. | |
384 | const unsigned char* | |
385 | data() const | |
386 | { return this->data_; } | |
387 | ||
388 | private: | |
389 | File_view(const File_view&); | |
390 | File_view& operator=(const File_view&); | |
391 | ||
392 | friend class File_read; | |
393 | ||
394 | // Callers have to get these via File_read::get_lasting_view. | |
395 | File_view(File_read& file, File_read::View* view, const unsigned char* data) | |
396 | : file_(file), view_(view), data_(data) | |
397 | { } | |
398 | ||
399 | File_read& file_; | |
400 | File_read::View* view_; | |
401 | const unsigned char* data_; | |
402 | }; | |
403 | ||
bae7f79e ILT |
404 | // All the information we hold for a single input file. This can be |
405 | // an object file, a shared library, or an archive. | |
406 | ||
407 | class Input_file | |
408 | { | |
409 | public: | |
5a6f7e2d | 410 | Input_file(const Input_file_argument* input_argument) |
e2aacd2c ILT |
411 | : input_argument_(input_argument), found_name_(), file_(), |
412 | is_in_sysroot_(false) | |
bae7f79e ILT |
413 | { } |
414 | ||
5a6f7e2d ILT |
415 | // Create an input file with the contents already provided. This is |
416 | // only used for testing. With this path, don't call the open | |
417 | // method. | |
17a1d0a9 ILT |
418 | Input_file(const Task*, const char* name, const unsigned char* contents, |
419 | off_t size); | |
5a6f7e2d | 420 | |
75f2446e ILT |
421 | // Open the file. If the open fails, this will report an error and |
422 | // return false. | |
423 | bool | |
17a1d0a9 | 424 | open(const General_options&, const Dirsearch&, const Task*); |
bae7f79e | 425 | |
e2aacd2c | 426 | // Return the name given by the user. For -lc this will return "c". |
bae7f79e | 427 | const char* |
14144f39 | 428 | name() const; |
bae7f79e | 429 | |
e2aacd2c ILT |
430 | // Return the file name. For -lc this will return something like |
431 | // "/usr/lib/libc.so". | |
bae7f79e ILT |
432 | const std::string& |
433 | filename() const | |
434 | { return this->file_.filename(); } | |
435 | ||
e2aacd2c ILT |
436 | // Return the name under which we found the file, corresponding to |
437 | // the command line. For -lc this will return something like | |
438 | // "libc.so". | |
439 | const std::string& | |
440 | found_name() const | |
441 | { return this->found_name_; } | |
442 | ||
4973341a ILT |
443 | // Return the position dependent options. |
444 | const Position_dependent_options& | |
14144f39 | 445 | options() const; |
4973341a ILT |
446 | |
447 | // Return the file. | |
bae7f79e ILT |
448 | File_read& |
449 | file() | |
450 | { return this->file_; } | |
451 | ||
7004837e ILT |
452 | const File_read& |
453 | file() const | |
454 | { return this->file_; } | |
455 | ||
ad2d6943 ILT |
456 | // Whether we found the file in a directory in the system root. |
457 | bool | |
458 | is_in_sysroot() const | |
459 | { return this->is_in_sysroot_; } | |
460 | ||
88dd47ac ILT |
461 | // Return whether this file is to be read only for its symbols. |
462 | bool | |
463 | just_symbols() const; | |
464 | ||
bae7f79e | 465 | private: |
ead1e424 ILT |
466 | Input_file(const Input_file&); |
467 | Input_file& operator=(const Input_file&); | |
468 | ||
bc644c6c ILT |
469 | // Open a binary file. |
470 | bool | |
0daa6f62 ILT |
471 | open_binary(const General_options&, const Task* task, |
472 | const std::string& name); | |
bc644c6c | 473 | |
ad2d6943 | 474 | // The argument from the command line. |
5a6f7e2d | 475 | const Input_file_argument* input_argument_; |
e2aacd2c ILT |
476 | // The name under which we opened the file. This is like the name |
477 | // on the command line, but -lc turns into libc.so (or whatever). | |
478 | // It only includes the full path if the path was on the command | |
479 | // line. | |
480 | std::string found_name_; | |
ad2d6943 | 481 | // The file after we open it. |
bae7f79e | 482 | File_read file_; |
ad2d6943 ILT |
483 | // Whether we found the file in a directory in the system root. |
484 | bool is_in_sysroot_; | |
bae7f79e ILT |
485 | }; |
486 | ||
487 | } // end namespace gold | |
488 | ||
489 | #endif // !defined(GOLD_FILEREAD_H) |