| // fileread.cc -- read files for gold |
| |
| // Copyright 2006, 2007 Free Software Foundation, Inc. |
| // Written by Ian Lance Taylor <iant@google.com>. |
| |
| // This file is part of gold. |
| |
| // This program is free software; you can redistribute it and/or modify |
| // it under the terms of the GNU General Public License as published by |
| // the Free Software Foundation; either version 3 of the License, or |
| // (at your option) any later version. |
| |
| // This program is distributed in the hope that it will be useful, |
| // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| // GNU General Public License for more details. |
| |
| // You should have received a copy of the GNU General Public License |
| // along with this program; if not, write to the Free Software |
| // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| // MA 02110-1301, USA. |
| |
| #include "gold.h" |
| |
| #include <cstring> |
| #include <cerrno> |
| #include <fcntl.h> |
| #include <unistd.h> |
| #include <sys/mman.h> |
| #include <sys/uio.h> |
| #include "filenames.h" |
| |
| #include "parameters.h" |
| #include "options.h" |
| #include "dirsearch.h" |
| #include "target.h" |
| #include "binary.h" |
| #include "fileread.h" |
| |
| namespace gold |
| { |
| |
| // Class File_read::View. |
| |
| File_read::View::~View() |
| { |
| gold_assert(!this->is_locked()); |
| if (!this->mapped_) |
| delete[] this->data_; |
| else |
| { |
| if (::munmap(const_cast<unsigned char*>(this->data_), this->size_) != 0) |
| gold_warning(_("munmap failed: %s"), strerror(errno)); |
| |
| File_read::current_mapped_bytes -= this->size_; |
| } |
| } |
| |
| void |
| File_read::View::lock() |
| { |
| ++this->lock_count_; |
| } |
| |
| void |
| File_read::View::unlock() |
| { |
| gold_assert(this->lock_count_ > 0); |
| --this->lock_count_; |
| } |
| |
| bool |
| File_read::View::is_locked() |
| { |
| return this->lock_count_ > 0; |
| } |
| |
| // Class File_read. |
| |
| // The File_read static variables. |
| unsigned long long File_read::total_mapped_bytes; |
| unsigned long long File_read::current_mapped_bytes; |
| unsigned long long File_read::maximum_mapped_bytes; |
| |
| // The File_read class is designed to support file descriptor caching, |
| // but this is not currently implemented. |
| |
| File_read::~File_read() |
| { |
| gold_assert(this->token_.is_writable()); |
| if (this->descriptor_ >= 0) |
| { |
| if (close(this->descriptor_) < 0) |
| gold_warning(_("close of %s failed: %s"), |
| this->name_.c_str(), strerror(errno)); |
| this->descriptor_ = -1; |
| } |
| this->name_.clear(); |
| this->clear_views(true); |
| } |
| |
| // Open the file. |
| |
| bool |
| File_read::open(const Task* task, const std::string& name) |
| { |
| gold_assert(this->token_.is_writable() |
| && this->descriptor_ < 0 |
| && this->name_.empty()); |
| this->name_ = name; |
| |
| this->descriptor_ = ::open(this->name_.c_str(), O_RDONLY); |
| |
| if (this->descriptor_ >= 0) |
| { |
| struct stat s; |
| if (::fstat(this->descriptor_, &s) < 0) |
| gold_error(_("%s: fstat failed: %s"), |
| this->name_.c_str(), strerror(errno)); |
| this->size_ = s.st_size; |
| } |
| |
| this->token_.add_writer(task); |
| |
| return this->descriptor_ >= 0; |
| } |
| |
| // Open the file with the contents in memory. |
| |
| bool |
| File_read::open(const Task* task, const std::string& name, |
| const unsigned char* contents, off_t size) |
| { |
| gold_assert(this->token_.is_writable() |
| && this->descriptor_ < 0 |
| && this->name_.empty()); |
| this->name_ = name; |
| this->contents_ = contents; |
| this->size_ = size; |
| this->token_.add_writer(task); |
| return true; |
| } |
| |
| // Release the file. This is called when we are done with the file in |
| // a Task. |
| |
| void |
| File_read::release() |
| { |
| gold_assert(this->is_locked()); |
| |
| File_read::total_mapped_bytes += this->mapped_bytes_; |
| File_read::current_mapped_bytes += this->mapped_bytes_; |
| this->mapped_bytes_ = 0; |
| if (File_read::current_mapped_bytes > File_read::maximum_mapped_bytes) |
| File_read::maximum_mapped_bytes = File_read::current_mapped_bytes; |
| |
| this->clear_views(false); |
| |
| this->released_ = true; |
| } |
| |
| // Lock the file. |
| |
| void |
| File_read::lock(const Task* task) |
| { |
| gold_assert(this->released_); |
| this->token_.add_writer(task); |
| this->released_ = false; |
| } |
| |
| // Unlock the file. |
| |
| void |
| File_read::unlock(const Task* task) |
| { |
| this->release(); |
| this->token_.remove_writer(task); |
| } |
| |
| // Return whether the file is locked. |
| |
| bool |
| File_read::is_locked() const |
| { |
| if (!this->token_.is_writable()) |
| return true; |
| // The file is not locked, so it should have been released. |
| gold_assert(this->released_); |
| return false; |
| } |
| |
| // See if we have a view which covers the file starting at START for |
| // SIZE bytes. Return a pointer to the View if found, NULL if not. |
| |
| inline File_read::View* |
| File_read::find_view(off_t start, section_size_type size) const |
| { |
| off_t page = File_read::page_offset(start); |
| |
| Views::const_iterator p = this->views_.lower_bound(page); |
| if (p == this->views_.end() || p->first > page) |
| { |
| if (p == this->views_.begin()) |
| return NULL; |
| --p; |
| } |
| |
| if (p->second->start() + static_cast<off_t>(p->second->size()) |
| < start + static_cast<off_t>(size)) |
| return NULL; |
| |
| p->second->set_accessed(); |
| |
| return p->second; |
| } |
| |
| // Read SIZE bytes from the file starting at offset START. Read into |
| // the buffer at P. |
| |
| void |
| File_read::do_read(off_t start, section_size_type size, void* p) const |
| { |
| ssize_t bytes; |
| if (this->contents_ != NULL) |
| { |
| bytes = this->size_ - start; |
| if (static_cast<section_size_type>(bytes) >= size) |
| { |
| memcpy(p, this->contents_ + start, size); |
| return; |
| } |
| } |
| else |
| { |
| bytes = ::pread(this->descriptor_, p, size, start); |
| if (static_cast<section_size_type>(bytes) == size) |
| return; |
| |
| if (bytes < 0) |
| { |
| gold_fatal(_("%s: pread failed: %s"), |
| this->filename().c_str(), strerror(errno)); |
| return; |
| } |
| } |
| |
| gold_fatal(_("%s: file too short: read only %lld of %lld bytes at %lld"), |
| this->filename().c_str(), |
| static_cast<long long>(bytes), |
| static_cast<long long>(size), |
| static_cast<long long>(start)); |
| } |
| |
| // Read data from the file. |
| |
| void |
| File_read::read(off_t start, section_size_type size, void* p) const |
| { |
| const File_read::View* pv = this->find_view(start, size); |
| if (pv != NULL) |
| { |
| memcpy(p, pv->data() + (start - pv->start()), size); |
| return; |
| } |
| |
| this->do_read(start, size, p); |
| } |
| |
| // Find an existing view or make a new one. |
| |
| File_read::View* |
| File_read::find_or_make_view(off_t start, section_size_type size, bool cache) |
| { |
| gold_assert(!this->token_.is_writable()); |
| this->released_ = false; |
| |
| File_read::View* v = this->find_view(start, size); |
| if (v != NULL) |
| { |
| if (cache) |
| v->set_cache(); |
| return v; |
| } |
| |
| off_t poff = File_read::page_offset(start); |
| |
| File_read::View* const vnull = NULL; |
| std::pair<Views::iterator, bool> ins = |
| this->views_.insert(std::make_pair(poff, vnull)); |
| |
| if (!ins.second) |
| { |
| // There was an existing view at this offset. It must not be |
| // large enough. We can't delete it here, since something might |
| // be using it; put it on a list to be deleted when the file is |
| // unlocked. |
| v = ins.first->second; |
| gold_assert(v->size() - (start - v->start()) < size); |
| if (v->should_cache()) |
| cache = true; |
| v->clear_cache(); |
| this->saved_views_.push_back(v); |
| } |
| |
| // We need to map data from the file. |
| |
| section_size_type psize = File_read::pages(size + (start - poff)); |
| |
| if (poff + static_cast<off_t>(psize) >= this->size_) |
| { |
| psize = this->size_ - poff; |
| gold_assert(psize >= size); |
| } |
| |
| if (this->contents_ != NULL) |
| { |
| unsigned char* p = new unsigned char[psize]; |
| this->do_read(poff, psize, p); |
| v = new File_read::View(poff, psize, p, cache, false); |
| } |
| else |
| { |
| void* p = ::mmap(NULL, psize, PROT_READ, MAP_PRIVATE, |
| this->descriptor_, poff); |
| if (p == MAP_FAILED) |
| gold_fatal(_("%s: mmap offset %lld size %lld failed: %s"), |
| this->filename().c_str(), |
| static_cast<long long>(poff), |
| static_cast<long long>(psize), |
| strerror(errno)); |
| |
| this->mapped_bytes_ += psize; |
| |
| const unsigned char* pbytes = static_cast<const unsigned char*>(p); |
| v = new File_read::View(poff, psize, pbytes, cache, true); |
| } |
| |
| ins.first->second = v; |
| return v; |
| } |
| |
| // Get a view into the file. |
| |
| const unsigned char* |
| File_read::get_view(off_t start, section_size_type size, bool cache) |
| { |
| File_read::View* pv = this->find_or_make_view(start, size, cache); |
| return pv->data() + (start - pv->start()); |
| } |
| |
| File_view* |
| File_read::get_lasting_view(off_t start, section_size_type size, bool cache) |
| { |
| File_read::View* pv = this->find_or_make_view(start, size, cache); |
| pv->lock(); |
| return new File_view(*this, pv, pv->data() + (start - pv->start())); |
| } |
| |
| // Use readv to read COUNT entries from RM starting at START. BASE |
| // must be added to all file offsets in RM. |
| |
| void |
| File_read::do_readv(off_t base, const Read_multiple& rm, size_t start, |
| size_t count) |
| { |
| unsigned char discard[File_read::page_size]; |
| iovec iov[File_read::max_readv_entries * 2]; |
| size_t iov_index = 0; |
| |
| off_t first_offset = rm[start].file_offset; |
| off_t last_offset = first_offset; |
| ssize_t want = 0; |
| for (size_t i = 0; i < count; ++i) |
| { |
| const Read_multiple_entry& i_entry(rm[start + i]); |
| |
| if (i_entry.file_offset > last_offset) |
| { |
| size_t skip = i_entry.file_offset - last_offset; |
| gold_assert(skip <= sizeof discard); |
| |
| iov[iov_index].iov_base = discard; |
| iov[iov_index].iov_len = skip; |
| ++iov_index; |
| |
| want += skip; |
| } |
| |
| iov[iov_index].iov_base = i_entry.buffer; |
| iov[iov_index].iov_len = i_entry.size; |
| ++iov_index; |
| |
| want += i_entry.size; |
| |
| last_offset = i_entry.file_offset + i_entry.size; |
| } |
| |
| gold_assert(iov_index < sizeof iov / sizeof iov[0]); |
| |
| if (::lseek(this->descriptor_, base + first_offset, SEEK_SET) < 0) |
| gold_fatal(_("%s: lseek failed: %s"), |
| this->filename().c_str(), strerror(errno)); |
| |
| ssize_t got = ::readv(this->descriptor_, iov, iov_index); |
| |
| if (got < 0) |
| gold_fatal(_("%s: readv failed: %s"), |
| this->filename().c_str(), strerror(errno)); |
| if (got != want) |
| gold_fatal(_("%s: file too short: read only %zd of %zd bytes at %lld"), |
| this->filename().c_str(), |
| got, want, static_cast<long long>(base + first_offset)); |
| } |
| |
| // Read several pieces of data from the file. |
| |
| void |
| File_read::read_multiple(off_t base, const Read_multiple& rm) |
| { |
| size_t count = rm.size(); |
| size_t i = 0; |
| while (i < count) |
| { |
| // Find up to MAX_READV_ENTRIES consecutive entries which are |
| // less than one page apart. |
| const Read_multiple_entry& i_entry(rm[i]); |
| off_t i_off = i_entry.file_offset; |
| off_t end_off = i_off + i_entry.size; |
| size_t j; |
| for (j = i + 1; j < count; ++j) |
| { |
| if (j - i >= File_read::max_readv_entries) |
| break; |
| const Read_multiple_entry& j_entry(rm[j]); |
| off_t j_off = j_entry.file_offset; |
| gold_assert(j_off >= end_off); |
| off_t j_end_off = j_off + j_entry.size; |
| if (j_end_off - end_off >= File_read::page_size) |
| break; |
| end_off = j_end_off; |
| } |
| |
| if (j == i + 1) |
| this->read(base + i_off, i_entry.size, i_entry.buffer); |
| else |
| { |
| File_read::View* view = this->find_view(base + i_off, |
| end_off - i_off); |
| if (view == NULL) |
| this->do_readv(base, rm, i, j - i); |
| else |
| { |
| const unsigned char* v = (view->data() |
| + (base + i_off - view->start())); |
| for (size_t k = i; k < j; ++k) |
| { |
| const Read_multiple_entry& k_entry(rm[k]); |
| gold_assert((convert_to_section_size_type(k_entry.file_offset |
| - i_off) |
| + k_entry.size) |
| <= convert_to_section_size_type(end_off |
| - i_off)); |
| memcpy(k_entry.buffer, |
| v + (k_entry.file_offset - i_off), |
| k_entry.size); |
| } |
| } |
| } |
| |
| i = j; |
| } |
| } |
| |
| // Mark all views as no longer cached. |
| |
| void |
| File_read::clear_view_cache_marks() |
| { |
| // Just ignore this if there are multiple objects associated with |
| // the file. Otherwise we will wind up uncaching and freeing some |
| // views for other objects. |
| if (this->object_count_ > 1) |
| return; |
| |
| for (Views::iterator p = this->views_.begin(); |
| p != this->views_.end(); |
| ++p) |
| p->second->clear_cache(); |
| for (Saved_views::iterator p = this->saved_views_.begin(); |
| p != this->saved_views_.end(); |
| ++p) |
| (*p)->clear_cache(); |
| } |
| |
| // Remove all the file views. For a file which has multiple |
| // associated objects (i.e., an archive), we keep accessed views |
| // around until next time, in the hopes that they will be useful for |
| // the next object. |
| |
| void |
| File_read::clear_views(bool destroying) |
| { |
| Views::iterator p = this->views_.begin(); |
| while (p != this->views_.end()) |
| { |
| bool should_delete; |
| if (p->second->is_locked()) |
| should_delete = false; |
| else if (destroying) |
| should_delete = true; |
| else if (p->second->should_cache()) |
| should_delete = false; |
| else if (this->object_count_ > 1 && p->second->accessed()) |
| should_delete = false; |
| else |
| should_delete = true; |
| |
| if (should_delete) |
| { |
| delete p->second; |
| |
| // map::erase invalidates only the iterator to the deleted |
| // element. |
| Views::iterator pe = p; |
| ++p; |
| this->views_.erase(pe); |
| } |
| else |
| { |
| gold_assert(!destroying); |
| p->second->clear_accessed(); |
| ++p; |
| } |
| } |
| |
| Saved_views::iterator q = this->saved_views_.begin(); |
| while (q != this->saved_views_.end()) |
| { |
| if (!(*q)->is_locked()) |
| { |
| delete *q; |
| q = this->saved_views_.erase(q); |
| } |
| else |
| { |
| gold_assert(!destroying); |
| ++q; |
| } |
| } |
| } |
| |
| // Print statistical information to stderr. This is used for --stats. |
| |
| void |
| File_read::print_stats() |
| { |
| fprintf(stderr, _("%s: total bytes mapped for read: %llu\n"), |
| program_name, File_read::total_mapped_bytes); |
| fprintf(stderr, _("%s: maximum bytes mapped for read at one time: %llu\n"), |
| program_name, File_read::maximum_mapped_bytes); |
| } |
| |
| // Class File_view. |
| |
| File_view::~File_view() |
| { |
| gold_assert(this->file_.is_locked()); |
| this->view_->unlock(); |
| } |
| |
| // Class Input_file. |
| |
| // Create a file for testing. |
| |
| Input_file::Input_file(const Task* task, const char* name, |
| const unsigned char* contents, off_t size) |
| : file_() |
| { |
| this->input_argument_ = |
| new Input_file_argument(name, false, "", false, |
| Position_dependent_options()); |
| bool ok = file_.open(task, name, contents, size); |
| gold_assert(ok); |
| } |
| |
| // Return the position dependent options in force for this file. |
| |
| const Position_dependent_options& |
| Input_file::options() const |
| { |
| return this->input_argument_->options(); |
| } |
| |
| // Return the name given by the user. For -lc this will return "c". |
| |
| const char* |
| Input_file::name() const |
| { |
| return this->input_argument_->name(); |
| } |
| |
| // Return whether we are only reading symbols. |
| |
| bool |
| Input_file::just_symbols() const |
| { |
| return this->input_argument_->just_symbols(); |
| } |
| |
| // Open the file. |
| |
| // If the filename is not absolute, we assume it is in the current |
| // directory *except* when: |
| // A) input_argument_->is_lib() is true; or |
| // B) input_argument_->extra_search_path() is not empty. |
| // In both cases, we look in extra_search_path + library_path to find |
| // the file location, rather than the current directory. |
| |
| bool |
| Input_file::open(const General_options& options, const Dirsearch& dirpath, |
| const Task* task) |
| { |
| std::string name; |
| |
| // Case 1: name is an absolute file, just try to open it |
| // Case 2: name is relative but is_lib is false and extra_search_path |
| // is empty |
| if (IS_ABSOLUTE_PATH (this->input_argument_->name()) |
| || (!this->input_argument_->is_lib() |
| && this->input_argument_->extra_search_path() == NULL)) |
| { |
| name = this->input_argument_->name(); |
| this->found_name_ = name; |
| } |
| // Case 3: is_lib is true |
| else if (this->input_argument_->is_lib()) |
| { |
| // We don't yet support extra_search_path with -l. |
| gold_assert(this->input_argument_->extra_search_path() == NULL); |
| std::string n1("lib"); |
| n1 += this->input_argument_->name(); |
| std::string n2; |
| if (options.is_static() |
| || this->input_argument_->options().do_static_search()) |
| n1 += ".a"; |
| else |
| { |
| n2 = n1 + ".a"; |
| n1 += ".so"; |
| } |
| name = dirpath.find(n1, n2, &this->is_in_sysroot_); |
| if (name.empty()) |
| { |
| gold_error(_("cannot find -l%s"), |
| this->input_argument_->name()); |
| return false; |
| } |
| if (n2.empty() || name[name.length() - 1] == 'o') |
| this->found_name_ = n1; |
| else |
| this->found_name_ = n2; |
| } |
| // Case 4: extra_search_path is not empty |
| else |
| { |
| gold_assert(this->input_argument_->extra_search_path() != NULL); |
| |
| // First, check extra_search_path. |
| name = this->input_argument_->extra_search_path(); |
| if (!IS_DIR_SEPARATOR (name[name.length() - 1])) |
| name += '/'; |
| name += this->input_argument_->name(); |
| struct stat dummy_stat; |
| if (::stat(name.c_str(), &dummy_stat) < 0) |
| { |
| // extra_search_path failed, so check the normal search-path. |
| name = dirpath.find(this->input_argument_->name(), "", |
| &this->is_in_sysroot_); |
| if (name.empty()) |
| { |
| gold_error(_("cannot find %s"), |
| this->input_argument_->name()); |
| return false; |
| } |
| } |
| this->found_name_ = this->input_argument_->name(); |
| } |
| |
| // Now that we've figured out where the file lives, try to open it. |
| |
| General_options::Object_format format = |
| this->input_argument_->options().input_format(); |
| bool ok; |
| if (format == General_options::OBJECT_FORMAT_ELF) |
| ok = this->file_.open(task, name); |
| else |
| { |
| gold_assert(format == General_options::OBJECT_FORMAT_BINARY); |
| ok = this->open_binary(options, task, name); |
| } |
| |
| if (!ok) |
| { |
| gold_error(_("cannot open %s: %s"), |
| name.c_str(), strerror(errno)); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| // Open a file for --format binary. |
| |
| bool |
| Input_file::open_binary(const General_options& options, |
| const Task* task, const std::string& name) |
| { |
| // In order to open a binary file, we need machine code, size, and |
| // endianness. We may not have a valid target at this point, in |
| // which case we use the default target. |
| Target* target; |
| if (parameters->is_target_valid()) |
| target = parameters->target(); |
| else |
| target = options.default_target(); |
| |
| Binary_to_elf binary_to_elf(target->machine_code(), |
| target->get_size(), |
| target->is_big_endian(), |
| name); |
| if (!binary_to_elf.convert(task)) |
| return false; |
| return this->file_.open(task, name, binary_to_elf.converted_data_leak(), |
| binary_to_elf.converted_size()); |
| } |
| |
| } // End namespace gold. |