// archive.h -- archive support for gold -*- C++ -*- // Copyright (C) 2006-2015 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. #ifndef GOLD_ARCHIVE_H #define GOLD_ARCHIVE_H #include <string> #include <vector> #include "fileread.h" #include "workqueue.h" namespace gold { class Task; class Input_argument; class Input_file; class Input_objects; class Input_group; class Layout; class Symbol_table; class Object; struct Read_symbols_data; class Input_file_lib; class Incremental_archive_entry; // An entry in the archive map of offsets to members. struct Archive_member { Archive_member() : obj_(NULL), sd_(NULL), arg_serial_(0) { } Archive_member(Object* obj, Read_symbols_data* sd) : obj_(obj), sd_(sd), arg_serial_(0) { } // The object file. Object* obj_; // The data to pass from read_symbols() to add_symbols(). Read_symbols_data* sd_; // The serial number of the file in the argument list. unsigned int arg_serial_; }; // This class serves as a base class for Archive and Lib_group objects. class Library_base { public: Library_base(Task* task) : task_(task), incremental_info_(NULL) { } virtual ~Library_base() { } // The file name. const std::string& filename() const { return this->do_filename(); } // The modification time of the archive file. Timespec get_mtime() { return this->do_get_mtime(); } // When we see a symbol in an archive we might decide to include the member, // not include the member or be undecided. This enum represents these // possibilities. enum Should_include { SHOULD_INCLUDE_NO, SHOULD_INCLUDE_YES, SHOULD_INCLUDE_UNKNOWN }; static Should_include should_include_member(Symbol_table* symtab, Layout*, const char* sym_name, Symbol** symp, std::string* why, char** tmpbufp, size_t* tmpbuflen); // Store a pointer to the incremental link info for the library. void set_incremental_info(Incremental_archive_entry* info) { this->incremental_info_ = info; } // Return the pointer to the incremental link info for the library. Incremental_archive_entry* incremental_info() const { return this->incremental_info_; } // Abstract base class for processing unused symbols. class Symbol_visitor_base { public: Symbol_visitor_base() { } virtual ~Symbol_visitor_base() { } // This function will be called for each unused global // symbol in a library, with a pointer to the symbol name. virtual void visit(const char* /* name */) = 0; }; // Iterator for unused global symbols in the library. // Calls v->visit() for each global symbol defined // in each unused library member, passing a pointer to // the symbol name. void for_all_unused_symbols(Symbol_visitor_base* v) const { this->do_for_all_unused_symbols(v); } protected: // The task reading this archive. Task *task_; private: // The file name. virtual const std::string& do_filename() const = 0; // Return the modification time of the archive file. virtual Timespec do_get_mtime() = 0; // Iterator for unused global symbols in the library. virtual void do_for_all_unused_symbols(Symbol_visitor_base* v) const = 0; // The incremental link information for this archive. Incremental_archive_entry* incremental_info_; }; // This class represents an archive--generally a libNAME.a file. // Archives have a symbol table and a list of objects. class Archive : public Library_base { public: Archive(const std::string& name, Input_file* input_file, bool is_thin_archive, Dirsearch* dirpath, Task* task); // The length of the magic string at the start of an archive. static const int sarmag = 8; // The magic string at the start of an archive. static const char armag[sarmag]; static const char armagt[sarmag]; // The string expected at the end of an archive member header. static const char arfmag[2]; // The name of the object. This is the name used on the command // line; e.g., if "-lgcc" is on the command line, this will be // "gcc". const std::string& name() const { return this->name_; } // The input file. const Input_file* input_file() const { return this->input_file_; } // Set up the archive: read the symbol map. void setup(); // Get a reference to the underlying file. File_read& file() { return this->input_file_->file(); } const File_read& file() const { return this->input_file_->file(); } // Lock the underlying file. void lock(const Task* t) { this->input_file_->file().lock(t); } // Unlock the underlying file. void unlock(const Task* t) { this->input_file_->file().unlock(t); } // Return whether the underlying file is locked. bool is_locked() const { return this->input_file_->file().is_locked(); } // Return the token, so that the task can be queued. Task_token* token() { return this->input_file_->file().token(); } // Release the underlying file. void release() { this->input_file_->file().release(); } // Clear uncached views in the underlying file. void clear_uncached_views() { this->input_file_->file().clear_uncached_views(); } // Whether this is a thin archive. bool is_thin_archive() const { return this->is_thin_archive_; } // Unlock any nested archives. void unlock_nested_archives(); // Select members from the archive as needed and add them to the // link. bool add_symbols(Symbol_table*, Layout*, Input_objects*, Mapfile*); // Return whether the archive defines the symbol. bool defines_symbol(Symbol*) const; // Dump statistical information to stderr. static void print_stats(); // Return the number of members in the archive. size_t count_members(); // Return the no-export flag. bool no_export() { return this->no_export_; } private: Archive(const Archive&); Archive& operator=(const Archive&); // The file name. const std::string& do_filename() const { return this->input_file_->filename(); } // The modification time of the archive file. Timespec do_get_mtime() { return this->file().get_mtime(); } struct Archive_header; // Total number of archives seen. static unsigned int total_archives; // Total number of archive members seen. static unsigned int total_members; // Number of archive members loaded. static unsigned int total_members_loaded; // Get a view into the underlying file. const unsigned char* get_view(off_t start, section_size_type size, bool aligned, bool cache) { return this->input_file_->file().get_view(0, start, size, aligned, cache); } // Read the archive symbol map. void read_armap(off_t start, section_size_type size); // Read an archive member header at OFF. CACHE is whether to cache // the file view. Return the size of the member, and set *PNAME to // the name. off_t read_header(off_t off, bool cache, std::string* pname, off_t* nested_off); // Interpret an archive header HDR at OFF. Return the size of the // member, and set *PNAME to the name. off_t interpret_header(const Archive_header* hdr, off_t off, std::string* pname, off_t* nested_off) const; // Get the file and offset for an archive member, which may be an // external member of a thin archive. Set *INPUT_FILE to the // file containing the actual member, *MEMOFF to the offset // within that file (0 if not a nested archive), and *MEMBER_NAME // to the name of the archive member. Return TRUE on success. bool get_file_and_offset(off_t off, Input_file** input_file, off_t* memoff, off_t* memsize, std::string* member_name); // Return an ELF object for the member at offset OFF. Object* get_elf_object_for_member(off_t off, bool*); // Read the symbols from all the archive members in the link. void read_all_symbols(); // Read the symbols from an archive member in the link. OFF is the file // offset of the member header. void read_symbols(off_t off); // Include all the archive members in the link. bool include_all_members(Symbol_table*, Layout*, Input_objects*, Mapfile*); // Include an archive member in the link. bool include_member(Symbol_table*, Layout*, Input_objects*, off_t off, Mapfile*, Symbol*, const char* why); // Return whether we found this archive by searching a directory. bool searched_for() const { return this->input_file_->will_search_for(); } // Iterate over archive members. class const_iterator; const_iterator begin(); const_iterator end(); friend class const_iterator; // Iterator for unused global symbols in the library. void do_for_all_unused_symbols(Symbol_visitor_base* v) const; // An entry in the archive map of symbols to object files. struct Armap_entry { // The offset to the symbol name in armap_names_. off_t name_offset; // The file offset to the object in the archive. off_t file_offset; }; // A simple hash code for off_t values. class Seen_hash { public: size_t operator()(off_t val) const { return static_cast<size_t>(val); } }; // For keeping track of open nested archives in a thin archive file. typedef Unordered_map<std::string, Archive*> Nested_archive_table; // Name of object as printed to user. std::string name_; // For reading the file. Input_file* input_file_; // The archive map. std::vector<Armap_entry> armap_; // The names in the archive map. std::string armap_names_; // The extended name table. std::string extended_names_; // Track which symbols in the archive map are for elements which are // defined or which have already been included in the link. std::vector<bool> armap_checked_; // Track which elements have been included by offset. Unordered_set<off_t, Seen_hash> seen_offsets_; // Table of objects whose symbols have been pre-read. std::map<off_t, Archive_member> members_; // True if this is a thin archive. const bool is_thin_archive_; // True if we have included at least one object from this archive. bool included_member_; // Table of nested archives, indexed by filename. Nested_archive_table nested_archives_; // The directory search path. Dirsearch* dirpath_; // Number of members in this archive; unsigned int num_members_; // True if we exclude this library archive from automatic export. bool no_export_; // True if this library has been included as a --whole-archive. bool included_all_members_; }; // This class is used to read an archive and pick out the desired // elements and add them to the link. class Add_archive_symbols : public Task { public: Add_archive_symbols(Symbol_table* symtab, Layout* layout, Input_objects* input_objects, Dirsearch* dirpath, int dirindex, Mapfile* mapfile, const Input_argument* input_argument, Archive* archive, Input_group* input_group, Task_token* this_blocker, Task_token* next_blocker) : symtab_(symtab), layout_(layout), input_objects_(input_objects), dirpath_(dirpath), dirindex_(dirindex), mapfile_(mapfile), input_argument_(input_argument), archive_(archive), input_group_(input_group), this_blocker_(this_blocker), next_blocker_(next_blocker) { } ~Add_archive_symbols(); // The standard Task methods. Task_token* is_runnable(); void locks(Task_locker*); void run(Workqueue*); std::string get_name() const { if (this->archive_ == NULL) return "Add_archive_symbols"; return "Add_archive_symbols " + this->archive_->file().filename(); } private: Symbol_table* symtab_; Layout* layout_; Input_objects* input_objects_; Dirsearch* dirpath_; int dirindex_; Mapfile* mapfile_; const Input_argument* input_argument_; Archive* archive_; Input_group* input_group_; Task_token* this_blocker_; Task_token* next_blocker_; }; // This class represents the files surrounded by a --start-lib ... --end-lib. class Lib_group : public Library_base { public: Lib_group(const Input_file_lib* lib, Task* task); // Select members from the lib group as needed and add them to the link. void add_symbols(Symbol_table*, Layout*, Input_objects*); // Include a member of the lib group in the link. void include_member(Symbol_table*, Layout*, Input_objects*, const Archive_member&); Archive_member* get_member(int i) { return &this->members_[i]; } // Total number of archives seen. static unsigned int total_lib_groups; // Total number of archive members seen. static unsigned int total_members; // Number of archive members loaded. static unsigned int total_members_loaded; // Dump statistical information to stderr. static void print_stats(); private: // The file name. const std::string& do_filename() const; // A Lib_group does not have a modification time, since there is no // real library file. Timespec do_get_mtime() { return Timespec(0, 0); } // Iterator for unused global symbols in the library. void do_for_all_unused_symbols(Symbol_visitor_base*) const; // Table of the objects in the group. std::vector<Archive_member> members_; }; // This class is used to pick out the desired elements and add them to the link. class Add_lib_group_symbols : public Task { public: Add_lib_group_symbols(Symbol_table* symtab, Layout* layout, Input_objects* input_objects, Lib_group* lib, Task_token* next_blocker) : symtab_(symtab), layout_(layout), input_objects_(input_objects), lib_(lib), readsyms_blocker_(NULL), this_blocker_(NULL), next_blocker_(next_blocker) { } ~Add_lib_group_symbols(); // The standard Task methods. Task_token* is_runnable(); void locks(Task_locker*); void run(Workqueue*); // Set the blocker to use for this task. void set_blocker(Task_token* readsyms_blocker, Task_token* this_blocker) { gold_assert(this->readsyms_blocker_ == NULL && this->this_blocker_ == NULL); this->readsyms_blocker_ = readsyms_blocker; this->this_blocker_ = this_blocker; } std::string get_name() const { return "Add_lib_group_symbols"; } private: Symbol_table* symtab_; Layout* layout_; Input_objects* input_objects_; Lib_group* lib_; Task_token* readsyms_blocker_; Task_token* this_blocker_; Task_token* next_blocker_; }; } // End namespace gold. #endif // !defined(GOLD_ARCHIVE_H)