1 // fileread.cc -- read files for gold
3 // Copyright 2006, 2007 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
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.
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.
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.
30 #include "filenames.h"
33 #include "dirsearch.h"
39 // Class File_read::View.
41 File_read::View::~View()
43 gold_assert(!this->is_locked());
48 if (::munmap(const_cast<unsigned char*>(this->data_), this->size_) != 0)
49 gold_warning(_("munmap failed: %s"), strerror(errno));
51 File_read::current_mapped_bytes -= this->size_;
56 File_read::View::lock()
62 File_read::View::unlock()
64 gold_assert(this->lock_count_ > 0);
69 File_read::View::is_locked()
71 return this->lock_count_ > 0;
76 // The File_read static variables.
77 unsigned long long File_read::total_mapped_bytes;
78 unsigned long long File_read::current_mapped_bytes;
79 unsigned long long File_read::maximum_mapped_bytes;
81 // The File_read class is designed to support file descriptor caching,
82 // but this is not currently implemented.
84 File_read::~File_read()
86 gold_assert(this->lock_count_ == 0);
87 if (this->descriptor_ >= 0)
89 if (close(this->descriptor_) < 0)
90 gold_warning(_("close of %s failed: %s"),
91 this->name_.c_str(), strerror(errno));
92 this->descriptor_ = -1;
95 this->clear_views(true);
101 File_read::open(const std::string& name)
103 gold_assert(this->lock_count_ == 0
104 && this->descriptor_ < 0
105 && this->name_.empty());
108 this->descriptor_ = ::open(this->name_.c_str(), O_RDONLY);
110 if (this->descriptor_ >= 0)
113 if (::fstat(this->descriptor_, &s) < 0)
114 gold_error(_("%s: fstat failed: %s"),
115 this->name_.c_str(), strerror(errno));
116 this->size_ = s.st_size;
121 return this->descriptor_ >= 0;
124 // Open the file for testing purposes.
127 File_read::open(const std::string& name, const unsigned char* contents,
130 gold_assert(this->lock_count_ == 0
131 && this->descriptor_ < 0
132 && this->name_.empty());
134 this->contents_ = contents;
149 gold_assert(this->lock_count_ > 0);
151 if (this->lock_count_ == 0)
153 File_read::total_mapped_bytes += this->mapped_bytes_;
154 File_read::current_mapped_bytes += this->mapped_bytes_;
155 this->mapped_bytes_ = 0;
156 if (File_read::current_mapped_bytes > File_read::maximum_mapped_bytes)
157 File_read::maximum_mapped_bytes = File_read::current_mapped_bytes;
159 this->clear_views(false);
164 File_read::is_locked() const
166 return this->lock_count_ > 0;
169 // See if we have a view which covers the file starting at START for
170 // SIZE bytes. Return a pointer to the View if found, NULL if not.
172 inline File_read::View*
173 File_read::find_view(off_t start, off_t size) const
175 off_t page = File_read::page_offset(start);
176 Views::const_iterator p = this->views_.find(page);
177 if (p == this->views_.end())
179 if (p->second->size() - (start - page) < size)
184 // Read SIZE bytes from the file starting at offset START. Read into
188 File_read::do_read(off_t start, off_t size, void* p) const
191 if (this->contents_ != NULL)
193 bytes = this->size_ - start;
196 memcpy(p, this->contents_ + start, size);
202 bytes = ::pread(this->descriptor_, p, size, start);
208 gold_fatal(_("%s: pread failed: %s"),
209 this->filename().c_str(), strerror(errno));
214 gold_fatal(_("%s: file too short: read only %lld of %lld bytes at %lld"),
215 this->filename().c_str(),
216 static_cast<long long>(bytes),
217 static_cast<long long>(size),
218 static_cast<long long>(start));
221 // Read data from the file.
224 File_read::read(off_t start, off_t size, void* p) const
226 File_read::View* pv = this->find_view(start, size);
229 memcpy(p, pv->data() + (start - pv->start()), size);
233 this->do_read(start, size, p);
236 // Find an existing view or make a new one.
239 File_read::find_or_make_view(off_t start, off_t size, bool cache)
241 gold_assert(this->lock_count_ > 0);
243 off_t poff = File_read::page_offset(start);
245 File_read::View* const vnull = NULL;
246 std::pair<Views::iterator, bool> ins =
247 this->views_.insert(std::make_pair(poff, vnull));
251 // There was an existing view at this offset.
252 File_read::View* v = ins.first->second;
253 if (v->size() - (start - v->start()) >= size)
260 // This view is not large enough.
261 this->saved_views_.push_back(v);
264 // We need to read data from the file. We read full pages for
265 // greater efficiency on small files.
267 off_t psize = File_read::pages(size + (start - poff));
269 if (poff + psize >= this->size_)
271 psize = this->size_ - poff;
272 gold_assert(psize >= size);
277 if (this->contents_ != NULL)
279 unsigned char* p = new unsigned char[psize];
280 this->do_read(poff, psize, p);
281 v = new File_read::View(poff, psize, p, cache, false);
285 void* p = ::mmap(NULL, psize, PROT_READ, MAP_SHARED,
286 this->descriptor_, poff);
288 gold_fatal(_("%s: mmap offset %lld size %lld failed: %s"),
289 this->filename().c_str(),
290 static_cast<long long>(poff),
291 static_cast<long long>(psize),
294 this->mapped_bytes_ += psize;
296 const unsigned char* pbytes = static_cast<const unsigned char*>(p);
297 v = new File_read::View(poff, psize, pbytes, cache, true);
300 ins.first->second = v;
304 // This implementation of get_view just reads into a memory buffer,
305 // which we store on view_list_. At some point we should support
309 File_read::get_view(off_t start, off_t size, bool cache)
311 gold_assert(this->lock_count_ > 0);
312 File_read::View* pv = this->find_or_make_view(start, size, cache);
313 return pv->data() + (start - pv->start());
317 File_read::get_lasting_view(off_t start, off_t size, bool cache)
319 gold_assert(this->lock_count_ > 0);
320 File_read::View* pv = this->find_or_make_view(start, size, cache);
322 return new File_view(*this, pv, pv->data() + (start - pv->start()));
325 // Remove all the file views.
328 File_read::clear_views(bool destroying)
330 Views::iterator p = this->views_.begin();
331 while (p != this->views_.end())
333 if (!p->second->is_locked()
334 && (destroying || !p->second->should_cache()))
338 // map::erase invalidates only the iterator to the deleted
340 Views::iterator pe = p;
342 this->views_.erase(pe);
346 gold_assert(!destroying);
351 Saved_views::iterator q = this->saved_views_.begin();
352 while (q != this->saved_views_.end())
354 if (!(*q)->is_locked()
355 && (destroying || !(*q)->should_cache()))
358 q = this->saved_views_.erase(q);
362 gold_assert(!destroying);
368 // Print statistical information to stderr. This is used for --stats.
371 File_read::print_stats()
373 fprintf(stderr, _("%s: total bytes mapped for read: %llu\n"),
374 program_name, File_read::total_mapped_bytes);
375 fprintf(stderr, _("%s: maximum bytes mapped for read at one time: %llu\n"),
376 program_name, File_read::maximum_mapped_bytes);
381 File_view::~File_view()
383 gold_assert(this->file_.is_locked());
384 this->view_->unlock();
389 // Create a file for testing.
391 Input_file::Input_file(const char* name, const unsigned char* contents,
395 this->input_argument_ =
396 new Input_file_argument(name, false, "", Position_dependent_options());
397 bool ok = file_.open(name, contents, size);
403 // If the filename is not absolute, we assume it is in the current
404 // directory *except* when:
405 // A) input_argument_->is_lib() is true; or
406 // B) input_argument_->extra_search_path() is not empty.
407 // In both cases, we look in extra_search_path + library_path to find
408 // the file location, rather than the current directory.
411 Input_file::open(const General_options& options, const Dirsearch& dirpath)
415 // Case 1: name is an absolute file, just try to open it
416 // Case 2: name is relative but is_lib is false and extra_search_path
418 if (IS_ABSOLUTE_PATH (this->input_argument_->name())
419 || (!this->input_argument_->is_lib()
420 && this->input_argument_->extra_search_path() == NULL))
422 name = this->input_argument_->name();
423 this->found_name_ = name;
425 // Case 3: is_lib is true
426 else if (this->input_argument_->is_lib())
428 // We don't yet support extra_search_path with -l.
429 gold_assert(this->input_argument_->extra_search_path() == NULL);
430 std::string n1("lib");
431 n1 += this->input_argument_->name();
433 if (options.is_static()
434 || this->input_argument_->options().do_static_search())
441 name = dirpath.find(n1, n2, &this->is_in_sysroot_);
444 gold_error(_("cannot find -l%s"),
445 this->input_argument_->name());
448 if (n2.empty() || name[name.length() - 1] == 'o')
449 this->found_name_ = n1;
451 this->found_name_ = n2;
453 // Case 4: extra_search_path is not empty
456 gold_assert(this->input_argument_->extra_search_path() != NULL);
458 // First, check extra_search_path.
459 name = this->input_argument_->extra_search_path();
460 if (!IS_DIR_SEPARATOR (name[name.length() - 1]))
462 name += this->input_argument_->name();
463 struct stat dummy_stat;
464 if (::stat(name.c_str(), &dummy_stat) < 0)
466 // extra_search_path failed, so check the normal search-path.
467 name = dirpath.find(this->input_argument_->name(), "",
468 &this->is_in_sysroot_);
471 gold_error(_("cannot find %s"),
472 this->input_argument_->name());
476 this->found_name_ = this->input_argument_->name();
479 // Now that we've figured out where the file lives, try to open it.
480 if (!this->file_.open(name))
482 gold_error(_("cannot open %s: %s"),
483 name.c_str(), strerror(errno));
490 } // End namespace gold.