| 1 | // archive.h -- archive support for gold -*- C++ -*- |
| 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 | #ifndef GOLD_ARCHIVE_H |
| 24 | #define GOLD_ARCHIVE_H |
| 25 | |
| 26 | #include <string> |
| 27 | #include <vector> |
| 28 | |
| 29 | #include "fileread.h" |
| 30 | #include "workqueue.h" |
| 31 | |
| 32 | namespace gold |
| 33 | { |
| 34 | |
| 35 | class Task; |
| 36 | class Input_file; |
| 37 | class Input_objects; |
| 38 | class Input_group; |
| 39 | class Layout; |
| 40 | class Symbol_table; |
| 41 | class Object; |
| 42 | class Read_symbols_data; |
| 43 | |
| 44 | // This class represents an archive--generally a libNAME.a file. |
| 45 | // Archives have a symbol table and a list of objects. |
| 46 | |
| 47 | class Archive |
| 48 | { |
| 49 | public: |
| 50 | Archive(const std::string& name, Input_file* input_file, |
| 51 | bool is_thin_archive, Dirsearch* dirpath, Task* task) |
| 52 | : name_(name), input_file_(input_file), armap_(), armap_names_(), |
| 53 | extended_names_(), armap_checked_(), seen_offsets_(), members_(), |
| 54 | is_thin_archive_(is_thin_archive), nested_archives_(), |
| 55 | dirpath_(dirpath), task_(task), num_members_(0) |
| 56 | { } |
| 57 | |
| 58 | // The length of the magic string at the start of an archive. |
| 59 | static const int sarmag = 8; |
| 60 | |
| 61 | // The magic string at the start of an archive. |
| 62 | static const char armag[sarmag]; |
| 63 | static const char armagt[sarmag]; |
| 64 | |
| 65 | // The string expected at the end of an archive member header. |
| 66 | static const char arfmag[2]; |
| 67 | |
| 68 | // The name of the object. This is the name used on the command |
| 69 | // line; e.g., if "-lgcc" is on the command line, this will be |
| 70 | // "gcc". |
| 71 | const std::string& |
| 72 | name() const |
| 73 | { return this->name_; } |
| 74 | |
| 75 | // The file name. |
| 76 | const std::string& |
| 77 | filename() const |
| 78 | { return this->input_file_->filename(); } |
| 79 | |
| 80 | // Set up the archive: read the symbol map. |
| 81 | void |
| 82 | setup(Input_objects*); |
| 83 | |
| 84 | // Get a reference to the underlying file. |
| 85 | File_read& |
| 86 | file() |
| 87 | { return this->input_file_->file(); } |
| 88 | |
| 89 | const File_read& |
| 90 | file() const |
| 91 | { return this->input_file_->file(); } |
| 92 | |
| 93 | // Lock the underlying file. |
| 94 | void |
| 95 | lock(const Task* t) |
| 96 | { this->input_file_->file().lock(t); } |
| 97 | |
| 98 | // Unlock the underlying file. |
| 99 | void |
| 100 | unlock(const Task* t) |
| 101 | { this->input_file_->file().unlock(t); } |
| 102 | |
| 103 | // Return whether the underlying file is locked. |
| 104 | bool |
| 105 | is_locked() const |
| 106 | { return this->input_file_->file().is_locked(); } |
| 107 | |
| 108 | // Return the token, so that the task can be queued. |
| 109 | Task_token* |
| 110 | token() |
| 111 | { return this->input_file_->file().token(); } |
| 112 | |
| 113 | // Release the underlying file. |
| 114 | void |
| 115 | release() |
| 116 | { this->input_file_->file().release(); } |
| 117 | |
| 118 | // Clear uncached views in the underlying file. |
| 119 | void |
| 120 | clear_uncached_views() |
| 121 | { this->input_file_->file().clear_uncached_views(); } |
| 122 | |
| 123 | // Whether this is a thin archive. |
| 124 | bool |
| 125 | is_thin_archive() const |
| 126 | { return this->is_thin_archive_; } |
| 127 | |
| 128 | // Unlock any nested archives. |
| 129 | void |
| 130 | unlock_nested_archives(); |
| 131 | |
| 132 | // Select members from the archive as needed and add them to the |
| 133 | // link. |
| 134 | void |
| 135 | add_symbols(Symbol_table*, Layout*, Input_objects*, Mapfile*); |
| 136 | |
| 137 | // Dump statistical information to stderr. |
| 138 | static void |
| 139 | print_stats(); |
| 140 | |
| 141 | // Return the number of members in the archive. |
| 142 | size_t |
| 143 | count_members(); |
| 144 | |
| 145 | private: |
| 146 | Archive(const Archive&); |
| 147 | Archive& operator=(const Archive&); |
| 148 | |
| 149 | struct Archive_header; |
| 150 | |
| 151 | // Total number of archives seen. |
| 152 | static unsigned int total_archives; |
| 153 | // Total number of archive members seen. |
| 154 | static unsigned int total_members; |
| 155 | // Number of archive members loaded. |
| 156 | static unsigned int total_members_loaded; |
| 157 | |
| 158 | // Get a view into the underlying file. |
| 159 | const unsigned char* |
| 160 | get_view(off_t start, section_size_type size, bool aligned, bool cache) |
| 161 | { return this->input_file_->file().get_view(0, start, size, aligned, cache); } |
| 162 | |
| 163 | // Read the archive symbol map. |
| 164 | void |
| 165 | read_armap(off_t start, section_size_type size); |
| 166 | |
| 167 | // Read an archive member header at OFF. CACHE is whether to cache |
| 168 | // the file view. Return the size of the member, and set *PNAME to |
| 169 | // the name. |
| 170 | off_t |
| 171 | read_header(off_t off, bool cache, std::string* pname, off_t* nested_off); |
| 172 | |
| 173 | // Interpret an archive header HDR at OFF. Return the size of the |
| 174 | // member, and set *PNAME to the name. |
| 175 | off_t |
| 176 | interpret_header(const Archive_header* hdr, off_t off, std::string* pname, |
| 177 | off_t* nested_off) const; |
| 178 | |
| 179 | // Get the file and offset for an archive member, which may be an |
| 180 | // external member of a thin archive. Set *INPUT_FILE to the |
| 181 | // file containing the actual member, *MEMOFF to the offset |
| 182 | // within that file (0 if not a nested archive), and *MEMBER_NAME |
| 183 | // to the name of the archive member. Return TRUE on success. |
| 184 | bool |
| 185 | get_file_and_offset(off_t off, Input_objects* input_objects, |
| 186 | Input_file** input_file, off_t* memoff, |
| 187 | off_t* memsize, std::string* member_name); |
| 188 | |
| 189 | // Return an ELF object for the member at offset OFF. Set *MEMBER_NAME to |
| 190 | // the name of the member. |
| 191 | Object* |
| 192 | get_elf_object_for_member(off_t off, Input_objects* input_objects); |
| 193 | |
| 194 | // Read the symbols from all the archive members in the link. |
| 195 | void |
| 196 | read_all_symbols(Input_objects* input_objects); |
| 197 | |
| 198 | // Read the symbols from an archive member in the link. OFF is the file |
| 199 | // offset of the member header. |
| 200 | void |
| 201 | read_symbols(Input_objects* input_objects, off_t off); |
| 202 | |
| 203 | // Include all the archive members in the link. |
| 204 | void |
| 205 | include_all_members(Symbol_table*, Layout*, Input_objects*, Mapfile*); |
| 206 | |
| 207 | // Include an archive member in the link. |
| 208 | void |
| 209 | include_member(Symbol_table*, Layout*, Input_objects*, off_t off, |
| 210 | Mapfile*, Symbol*, const char* why); |
| 211 | |
| 212 | // Iterate over archive members. |
| 213 | class const_iterator; |
| 214 | |
| 215 | const_iterator |
| 216 | begin(); |
| 217 | |
| 218 | const_iterator |
| 219 | end(); |
| 220 | |
| 221 | friend class const_iterator; |
| 222 | |
| 223 | // An entry in the archive map of symbols to object files. |
| 224 | struct Armap_entry |
| 225 | { |
| 226 | // The offset to the symbol name in armap_names_. |
| 227 | off_t name_offset; |
| 228 | // The file offset to the object in the archive. |
| 229 | off_t file_offset; |
| 230 | }; |
| 231 | |
| 232 | // An entry in the archive map of offsets to members. |
| 233 | struct Archive_member |
| 234 | { |
| 235 | Archive_member() |
| 236 | : obj_(NULL), sd_(NULL) |
| 237 | { } |
| 238 | Archive_member(Object* obj, Read_symbols_data* sd) |
| 239 | : obj_(obj), sd_(sd) |
| 240 | { } |
| 241 | // The object file. |
| 242 | Object* obj_; |
| 243 | // The data to pass from read_symbols() to add_symbols(). |
| 244 | Read_symbols_data* sd_; |
| 245 | }; |
| 246 | |
| 247 | // A simple hash code for off_t values. |
| 248 | class Seen_hash |
| 249 | { |
| 250 | public: |
| 251 | size_t operator()(off_t val) const |
| 252 | { return static_cast<size_t>(val); } |
| 253 | }; |
| 254 | |
| 255 | // For keeping track of open nested archives in a thin archive file. |
| 256 | typedef Unordered_map<std::string, Archive*> Nested_archive_table; |
| 257 | |
| 258 | // Name of object as printed to user. |
| 259 | std::string name_; |
| 260 | // For reading the file. |
| 261 | Input_file* input_file_; |
| 262 | // The archive map. |
| 263 | std::vector<Armap_entry> armap_; |
| 264 | // The names in the archive map. |
| 265 | std::string armap_names_; |
| 266 | // The extended name table. |
| 267 | std::string extended_names_; |
| 268 | // Track which symbols in the archive map are for elements which are |
| 269 | // defined or which have already been included in the link. |
| 270 | std::vector<bool> armap_checked_; |
| 271 | // Track which elements have been included by offset. |
| 272 | Unordered_set<off_t, Seen_hash> seen_offsets_; |
| 273 | // Table of objects whose symbols have been pre-read. |
| 274 | std::map<off_t, Archive_member> members_; |
| 275 | // True if this is a thin archive. |
| 276 | const bool is_thin_archive_; |
| 277 | // Table of nested archives, indexed by filename. |
| 278 | Nested_archive_table nested_archives_; |
| 279 | // The directory search path. |
| 280 | Dirsearch* dirpath_; |
| 281 | // The task reading this archive. |
| 282 | Task *task_; |
| 283 | // Number of members in this archive; |
| 284 | unsigned int num_members_; |
| 285 | }; |
| 286 | |
| 287 | // This class is used to read an archive and pick out the desired |
| 288 | // elements and add them to the link. |
| 289 | |
| 290 | class Add_archive_symbols : public Task |
| 291 | { |
| 292 | public: |
| 293 | Add_archive_symbols(Symbol_table* symtab, Layout* layout, |
| 294 | Input_objects* input_objects, Mapfile* mapfile, |
| 295 | Archive* archive, Input_group* input_group, |
| 296 | Task_token* this_blocker, |
| 297 | Task_token* next_blocker) |
| 298 | : symtab_(symtab), layout_(layout), input_objects_(input_objects), |
| 299 | mapfile_(mapfile), archive_(archive), input_group_(input_group), |
| 300 | this_blocker_(this_blocker), next_blocker_(next_blocker) |
| 301 | { } |
| 302 | |
| 303 | ~Add_archive_symbols(); |
| 304 | |
| 305 | // The standard Task methods. |
| 306 | |
| 307 | Task_token* |
| 308 | is_runnable(); |
| 309 | |
| 310 | void |
| 311 | locks(Task_locker*); |
| 312 | |
| 313 | void |
| 314 | run(Workqueue*); |
| 315 | |
| 316 | std::string |
| 317 | get_name() const |
| 318 | { |
| 319 | if (this->archive_ == NULL) |
| 320 | return "Add_archive_symbols"; |
| 321 | return "Add_archive_symbols " + this->archive_->file().filename(); |
| 322 | } |
| 323 | |
| 324 | private: |
| 325 | Symbol_table* symtab_; |
| 326 | Layout* layout_; |
| 327 | Input_objects* input_objects_; |
| 328 | Mapfile* mapfile_; |
| 329 | Archive* archive_; |
| 330 | Input_group* input_group_; |
| 331 | Task_token* this_blocker_; |
| 332 | Task_token* next_blocker_; |
| 333 | }; |
| 334 | |
| 335 | } // End namespace gold. |
| 336 | |
| 337 | #endif // !defined(GOLD_ARCHIVE_H) |