| 1 | // dirsearch.cc -- directory searching for gold |
| 2 | |
| 3 | // Copyright 2006, 2007, 2008 Free Software Foundation, Inc. |
| 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 | |
| 23 | #include "gold.h" |
| 24 | |
| 25 | #include <cerrno> |
| 26 | #include <cstring> |
| 27 | #include <sys/types.h> |
| 28 | #include <dirent.h> |
| 29 | |
| 30 | #include "debug.h" |
| 31 | #include "gold-threads.h" |
| 32 | #include "options.h" |
| 33 | #include "workqueue.h" |
| 34 | #include "dirsearch.h" |
| 35 | |
| 36 | namespace |
| 37 | { |
| 38 | |
| 39 | // Read all the files in a directory. |
| 40 | |
| 41 | class Dir_cache |
| 42 | { |
| 43 | public: |
| 44 | Dir_cache(const char* dirname) |
| 45 | : dirname_(dirname), files_() |
| 46 | { } |
| 47 | |
| 48 | // Read the files in the directory. |
| 49 | void read_files(); |
| 50 | |
| 51 | // Return whether a file (a base name) is present in the directory. |
| 52 | bool find(const std::string&) const; |
| 53 | |
| 54 | private: |
| 55 | // We can not copy this class. |
| 56 | Dir_cache(const Dir_cache&); |
| 57 | Dir_cache& operator=(const Dir_cache&); |
| 58 | |
| 59 | const char* dirname_; |
| 60 | Unordered_set<std::string> files_; |
| 61 | }; |
| 62 | |
| 63 | void |
| 64 | Dir_cache::read_files() |
| 65 | { |
| 66 | DIR* d = opendir(this->dirname_); |
| 67 | if (d == NULL) |
| 68 | { |
| 69 | // We ignore directories which do not exist. |
| 70 | if (errno != ENOENT) |
| 71 | gold::gold_error(_("%s: can not read directory: %s"), |
| 72 | this->dirname_, strerror(errno)); |
| 73 | return; |
| 74 | } |
| 75 | |
| 76 | dirent* de; |
| 77 | while ((de = readdir(d)) != NULL) |
| 78 | this->files_.insert(std::string(de->d_name)); |
| 79 | |
| 80 | if (closedir(d) != 0) |
| 81 | gold::gold_warning("%s: closedir failed: %s", this->dirname_, |
| 82 | strerror(errno)); |
| 83 | } |
| 84 | |
| 85 | bool |
| 86 | Dir_cache::find(const std::string& basename) const |
| 87 | { |
| 88 | return this->files_.find(basename) != this->files_.end(); |
| 89 | } |
| 90 | |
| 91 | // A mapping from directory names to caches. A lock permits |
| 92 | // concurrent update. There is no lock for read operations--some |
| 93 | // other mechanism must be used to prevent reads from conflicting with |
| 94 | // writes. |
| 95 | |
| 96 | class Dir_caches |
| 97 | { |
| 98 | public: |
| 99 | Dir_caches() |
| 100 | : lock_(), caches_() |
| 101 | { } |
| 102 | |
| 103 | ~Dir_caches(); |
| 104 | |
| 105 | // Add a cache for a directory. |
| 106 | void add(const char*); |
| 107 | |
| 108 | // Look up a directory in the cache. This much be locked against |
| 109 | // calls to Add. |
| 110 | Dir_cache* lookup(const char*) const; |
| 111 | |
| 112 | private: |
| 113 | // We can not copy this class. |
| 114 | Dir_caches(const Dir_caches&); |
| 115 | Dir_caches& operator=(const Dir_caches&); |
| 116 | |
| 117 | typedef Unordered_map<const char*, Dir_cache*> Cache_hash; |
| 118 | |
| 119 | gold::Lock lock_; |
| 120 | Cache_hash caches_; |
| 121 | }; |
| 122 | |
| 123 | Dir_caches::~Dir_caches() |
| 124 | { |
| 125 | for (Cache_hash::iterator p = this->caches_.begin(); |
| 126 | p != this->caches_.end(); |
| 127 | ++p) |
| 128 | delete p->second; |
| 129 | } |
| 130 | |
| 131 | void |
| 132 | Dir_caches::add(const char* dirname) |
| 133 | { |
| 134 | { |
| 135 | gold::Hold_lock hl(this->lock_); |
| 136 | if (this->lookup(dirname) != NULL) |
| 137 | return; |
| 138 | } |
| 139 | |
| 140 | Dir_cache* cache = new Dir_cache(dirname); |
| 141 | |
| 142 | cache->read_files(); |
| 143 | |
| 144 | { |
| 145 | gold::Hold_lock hl(this->lock_); |
| 146 | |
| 147 | std::pair<const char*, Dir_cache*> v(dirname, cache); |
| 148 | std::pair<Cache_hash::iterator, bool> p = this->caches_.insert(v); |
| 149 | gold_assert(p.second); |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | Dir_cache* |
| 154 | Dir_caches::lookup(const char* dirname) const |
| 155 | { |
| 156 | Cache_hash::const_iterator p = this->caches_.find(dirname); |
| 157 | if (p == this->caches_.end()) |
| 158 | return NULL; |
| 159 | return p->second; |
| 160 | } |
| 161 | |
| 162 | // The caches. |
| 163 | |
| 164 | Dir_caches* caches; |
| 165 | |
| 166 | // A Task to read the directory. |
| 167 | |
| 168 | class Dir_cache_task : public gold::Task |
| 169 | { |
| 170 | public: |
| 171 | Dir_cache_task(const char* dir, gold::Task_token& token) |
| 172 | : dir_(dir), token_(token) |
| 173 | { } |
| 174 | |
| 175 | gold::Task_token* |
| 176 | is_runnable(); |
| 177 | |
| 178 | void |
| 179 | locks(gold::Task_locker*); |
| 180 | |
| 181 | void |
| 182 | run(gold::Workqueue*); |
| 183 | |
| 184 | std::string |
| 185 | get_name() const |
| 186 | { return std::string("Dir_cache_task ") + this->dir_; } |
| 187 | |
| 188 | private: |
| 189 | const char* dir_; |
| 190 | gold::Task_token& token_; |
| 191 | }; |
| 192 | |
| 193 | // We can always run the task to read the directory. |
| 194 | |
| 195 | gold::Task_token* |
| 196 | Dir_cache_task::is_runnable() |
| 197 | { |
| 198 | return NULL; |
| 199 | } |
| 200 | |
| 201 | // Return the locks to hold. We use a blocker lock to prevent file |
| 202 | // lookups from starting until the directory contents have been read. |
| 203 | |
| 204 | void |
| 205 | Dir_cache_task::locks(gold::Task_locker* tl) |
| 206 | { |
| 207 | tl->add(this, &this->token_); |
| 208 | } |
| 209 | |
| 210 | // Run the task--read the directory contents. |
| 211 | |
| 212 | void |
| 213 | Dir_cache_task::run(gold::Workqueue*) |
| 214 | { |
| 215 | caches->add(this->dir_); |
| 216 | } |
| 217 | |
| 218 | } |
| 219 | |
| 220 | namespace gold |
| 221 | { |
| 222 | |
| 223 | void |
| 224 | Dirsearch::initialize(Workqueue* workqueue, |
| 225 | const General_options::Dir_list* directories) |
| 226 | { |
| 227 | gold_assert(caches == NULL); |
| 228 | caches = new Dir_caches; |
| 229 | this->directories_ = directories; |
| 230 | for (General_options::Dir_list::const_iterator p = directories->begin(); |
| 231 | p != directories->end(); |
| 232 | ++p) |
| 233 | { |
| 234 | this->token_.add_blocker(); |
| 235 | workqueue->queue(new Dir_cache_task(p->name().c_str(), this->token_)); |
| 236 | } |
| 237 | } |
| 238 | |
| 239 | // NOTE: we only log failed file-lookup attempts here. Successfully |
| 240 | // lookups will eventually get logged in File_read::open. |
| 241 | |
| 242 | std::string |
| 243 | Dirsearch::find(const std::string& n1, const std::string& n2, |
| 244 | bool *is_in_sysroot) const |
| 245 | { |
| 246 | gold_assert(!this->token_.is_blocked()); |
| 247 | |
| 248 | for (General_options::Dir_list::const_iterator p = |
| 249 | this->directories_->begin(); |
| 250 | p != this->directories_->end(); |
| 251 | ++p) |
| 252 | { |
| 253 | Dir_cache* pdc = caches->lookup(p->name().c_str()); |
| 254 | gold_assert(pdc != NULL); |
| 255 | if (pdc->find(n1)) |
| 256 | { |
| 257 | *is_in_sysroot = p->is_in_sysroot(); |
| 258 | return p->name() + '/' + n1; |
| 259 | } |
| 260 | else |
| 261 | gold_debug(DEBUG_FILES, "Attempt to open %s/%s failed", |
| 262 | p->name().c_str(), n1.c_str()); |
| 263 | |
| 264 | if (!n2.empty()) |
| 265 | { |
| 266 | if (pdc->find(n2)) |
| 267 | { |
| 268 | *is_in_sysroot = p->is_in_sysroot(); |
| 269 | return p->name() + '/' + n2; |
| 270 | } |
| 271 | else |
| 272 | gold_debug(DEBUG_FILES, "Attempt to open %s/%s failed", |
| 273 | p->name().c_str(), n2.c_str()); |
| 274 | } |
| 275 | } |
| 276 | |
| 277 | return std::string(); |
| 278 | } |
| 279 | |
| 280 | } // End namespace gold. |