// plugin.cc -- plugin manager for gold -*- C++ -*- // Copyright 2008, 2009 Free Software Foundation, Inc. // Written by Cary Coutant . // 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 #include #include #include #include #include #include "gold.h" #include "parameters.h" #include "errors.h" #include "fileread.h" #include "layout.h" #include "options.h" #include "plugin.h" #include "target.h" #include "readsyms.h" #include "symtab.h" #include "elfcpp.h" namespace gold { #ifdef ENABLE_PLUGINS // The linker's exported interfaces. extern "C" { static enum ld_plugin_status register_claim_file(ld_plugin_claim_file_handler handler); static enum ld_plugin_status register_all_symbols_read(ld_plugin_all_symbols_read_handler handler); static enum ld_plugin_status register_cleanup(ld_plugin_cleanup_handler handler); static enum ld_plugin_status add_symbols(void *handle, int nsyms, const struct ld_plugin_symbol *syms); static enum ld_plugin_status get_input_file(const void *handle, struct ld_plugin_input_file *file); static enum ld_plugin_status release_input_file(const void *handle); static enum ld_plugin_status get_symbols(const void *handle, int nsyms, struct ld_plugin_symbol *syms); static enum ld_plugin_status add_input_file(char *pathname); static enum ld_plugin_status add_input_library(char *pathname); static enum ld_plugin_status message(int level, const char *format, ...); }; #endif // ENABLE_PLUGINS static Pluginobj* make_sized_plugin_object(Input_file* input_file, off_t offset, off_t filesize); // Plugin methods. // Load one plugin library. void Plugin::load() { #ifdef ENABLE_PLUGINS // Load the plugin library. // FIXME: Look for the library in standard locations. this->handle_ = dlopen(this->filename_.c_str(), RTLD_NOW); if (this->handle_ == NULL) { gold_error(_("%s: could not load plugin library"), this->filename_.c_str()); return; } // Find the plugin's onload entry point. ld_plugin_onload onload = reinterpret_cast (dlsym(this->handle_, "onload")); if (onload == NULL) { gold_error(_("%s: could not find onload entry point"), this->filename_.c_str()); return; } // Get the linker's version number. const char* ver = get_version_string(); int major = 0; int minor = 0; sscanf(ver, "%d.%d", &major, &minor); // Allocate and populate a transfer vector. const int tv_fixed_size = 14; int tv_size = this->args_.size() + tv_fixed_size; ld_plugin_tv *tv = new ld_plugin_tv[tv_size]; // Put LDPT_MESSAGE at the front of the list so the plugin can use it // while processing subsequent entries. int i = 0; tv[i].tv_tag = LDPT_MESSAGE; tv[i].tv_u.tv_message = message; ++i; tv[i].tv_tag = LDPT_API_VERSION; tv[i].tv_u.tv_val = LD_PLUGIN_API_VERSION; ++i; tv[i].tv_tag = LDPT_GOLD_VERSION; tv[i].tv_u.tv_val = major * 100 + minor; ++i; tv[i].tv_tag = LDPT_LINKER_OUTPUT; if (parameters->options().relocatable()) tv[i].tv_u.tv_val = LDPO_REL; else if (parameters->options().shared()) tv[i].tv_u.tv_val = LDPO_DYN; else tv[i].tv_u.tv_val = LDPO_EXEC; for (unsigned int j = 0; j < this->args_.size(); ++j) { ++i; tv[i].tv_tag = LDPT_OPTION; tv[i].tv_u.tv_string = this->args_[j].c_str(); } ++i; tv[i].tv_tag = LDPT_REGISTER_CLAIM_FILE_HOOK; tv[i].tv_u.tv_register_claim_file = register_claim_file; ++i; tv[i].tv_tag = LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK; tv[i].tv_u.tv_register_all_symbols_read = register_all_symbols_read; ++i; tv[i].tv_tag = LDPT_REGISTER_CLEANUP_HOOK; tv[i].tv_u.tv_register_cleanup = register_cleanup; ++i; tv[i].tv_tag = LDPT_ADD_SYMBOLS; tv[i].tv_u.tv_add_symbols = add_symbols; ++i; tv[i].tv_tag = LDPT_GET_INPUT_FILE; tv[i].tv_u.tv_get_input_file = get_input_file; ++i; tv[i].tv_tag = LDPT_RELEASE_INPUT_FILE; tv[i].tv_u.tv_release_input_file = release_input_file; ++i; tv[i].tv_tag = LDPT_GET_SYMBOLS; tv[i].tv_u.tv_get_symbols = get_symbols; ++i; tv[i].tv_tag = LDPT_ADD_INPUT_FILE; tv[i].tv_u.tv_add_input_file = add_input_file; ++i; tv[i].tv_tag = LDPT_ADD_INPUT_LIBRARY; tv[i].tv_u.tv_add_input_library = add_input_library; ++i; tv[i].tv_tag = LDPT_NULL; tv[i].tv_u.tv_val = 0; gold_assert(i == tv_size - 1); // Call the onload entry point. (*onload)(tv); delete[] tv; #endif // ENABLE_PLUGINS } // Call the plugin claim-file handler. inline bool Plugin::claim_file(struct ld_plugin_input_file *plugin_input_file) { int claimed = 0; if (this->claim_file_handler_ != NULL) { (*this->claim_file_handler_)(plugin_input_file, &claimed); if (claimed) return true; } return false; } // Call the all-symbols-read handler. inline void Plugin::all_symbols_read() { if (this->all_symbols_read_handler_ != NULL) (*this->all_symbols_read_handler_)(); } // Call the cleanup handler. inline void Plugin::cleanup() { if (this->cleanup_handler_ != NULL) (*this->cleanup_handler_)(); } // Plugin_manager methods. Plugin_manager::~Plugin_manager() { for (Plugin_list::iterator p = this->plugins_.begin(); p != this->plugins_.end(); ++p) delete *p; this->plugins_.clear(); for (Object_list::iterator obj = this->objects_.begin(); obj != this->objects_.end(); ++obj) delete *obj; this->objects_.clear(); } // Load all plugin libraries. void Plugin_manager::load_plugins() { for (this->current_ = this->plugins_.begin(); this->current_ != this->plugins_.end(); ++this->current_) (*this->current_)->load(); } // Call the plugin claim-file handlers in turn to see if any claim the file. Pluginobj* Plugin_manager::claim_file(Input_file* input_file, off_t offset, off_t filesize) { if (this->in_replacement_phase_) return NULL; unsigned int handle = this->objects_.size(); this->input_file_ = input_file; this->plugin_input_file_.name = input_file->filename().c_str(); this->plugin_input_file_.fd = input_file->file().descriptor(); this->plugin_input_file_.offset = offset; this->plugin_input_file_.filesize = filesize; this->plugin_input_file_.handle = reinterpret_cast(handle); for (this->current_ = this->plugins_.begin(); this->current_ != this->plugins_.end(); ++this->current_) { if ((*this->current_)->claim_file(&this->plugin_input_file_)) { if (this->objects_.size() > handle) return this->objects_[handle]; // If the plugin claimed the file but did not call the // add_symbols callback, we need to create the Pluginobj now. Pluginobj* obj = this->make_plugin_object(handle); return obj; } } return NULL; } // Call the all-symbols-read handlers. void Plugin_manager::all_symbols_read(Workqueue* workqueue, Task* task, Input_objects* input_objects, Symbol_table* symtab, Layout* layout, Dirsearch* dirpath, Mapfile* mapfile, Task_token** last_blocker) { this->in_replacement_phase_ = true; this->workqueue_ = workqueue; this->task_ = task; this->input_objects_ = input_objects; this->symtab_ = symtab; this->layout_ = layout; this->dirpath_ = dirpath; this->mapfile_ = mapfile; this->this_blocker_ = NULL; for (this->current_ = this->plugins_.begin(); this->current_ != this->plugins_.end(); ++this->current_) (*this->current_)->all_symbols_read(); *last_blocker = this->this_blocker_; } // Layout deferred objects. void Plugin_manager::layout_deferred_objects() { Deferred_layout_list::iterator obj; for (obj = this->deferred_layout_objects_.begin(); obj != this->deferred_layout_objects_.end(); ++obj) (*obj)->layout_deferred_sections(this->layout_); } // Call the cleanup handlers. void Plugin_manager::cleanup() { if (this->cleanup_done_) return; for (this->current_ = this->plugins_.begin(); this->current_ != this->plugins_.end(); ++this->current_) (*this->current_)->cleanup(); this->cleanup_done_ = true; } // Make a new Pluginobj object. This is called when the plugin calls // the add_symbols API. Pluginobj* Plugin_manager::make_plugin_object(unsigned int handle) { // Make sure we aren't asked to make an object for the same handle twice. if (this->objects_.size() != handle) return NULL; Pluginobj* obj = make_sized_plugin_object(this->input_file_, this->plugin_input_file_.offset, this->plugin_input_file_.filesize); this->objects_.push_back(obj); return obj; } // Get the input file information with an open (possibly re-opened) // file descriptor. ld_plugin_status Plugin_manager::get_input_file(unsigned int handle, struct ld_plugin_input_file *file) { Pluginobj* obj = this->object(handle); if (obj == NULL) return LDPS_BAD_HANDLE; obj->lock(this->task_); file->name = obj->filename().c_str(); file->fd = obj->descriptor(); file->offset = obj->offset(); file->filesize = obj->filesize(); file->handle = reinterpret_cast(handle); return LDPS_OK; } // Release the input file. ld_plugin_status Plugin_manager::release_input_file(unsigned int handle) { Pluginobj* obj = this->object(handle); if (obj == NULL) return LDPS_BAD_HANDLE; obj->unlock(this->task_); return LDPS_OK; } // Add a new input file. ld_plugin_status Plugin_manager::add_input_file(char *pathname, bool is_lib) { Input_file_argument file(pathname, is_lib, "", false, this->options_); Input_argument* input_argument = new Input_argument(file); Task_token* next_blocker = new Task_token(true); next_blocker->add_blocker(); if (this->layout_->incremental_inputs()) gold_error(_("Input files added by plug-ins in --incremental mode not " "supported yet.\n")); this->workqueue_->queue_soon(new Read_symbols(this->input_objects_, this->symtab_, this->layout_, this->dirpath_, 0, this->mapfile_, input_argument, NULL, this->this_blocker_, next_blocker)); this->this_blocker_ = next_blocker; return LDPS_OK; } // Class Pluginobj. Pluginobj::Pluginobj(const std::string& name, Input_file* input_file, off_t offset, off_t filesize) : Object(name, input_file, false, offset), nsyms_(0), syms_(NULL), symbols_(), filesize_(filesize), comdat_map_() { } // Return TRUE if a defined symbol might be reachable from outside the // universe of claimed objects. static inline bool is_visible_from_outside(Symbol* lsym) { if (lsym->in_real_elf()) return true; if (parameters->options().relocatable()) return true; if (parameters->options().export_dynamic() || parameters->options().shared()) return lsym->is_externally_visible(); return false; } // Get symbol resolution info. ld_plugin_status Pluginobj::get_symbol_resolution_info(int nsyms, ld_plugin_symbol* syms) const { if (nsyms > this->nsyms_) return LDPS_NO_SYMS; for (int i = 0; i < nsyms; i++) { ld_plugin_symbol* isym = &syms[i]; Symbol* lsym = this->symbols_[i]; ld_plugin_symbol_resolution res = LDPR_UNKNOWN; if (lsym->is_undefined()) // The symbol remains undefined. res = LDPR_UNDEF; else if (isym->def == LDPK_UNDEF || isym->def == LDPK_WEAKUNDEF || isym->def == LDPK_COMMON) { // The original symbol was undefined or common. if (lsym->source() != Symbol::FROM_OBJECT) res = LDPR_RESOLVED_EXEC; else if (lsym->object()->pluginobj() != NULL) res = LDPR_RESOLVED_IR; else if (lsym->object()->is_dynamic()) res = LDPR_RESOLVED_DYN; else res = LDPR_RESOLVED_EXEC; } else { // The original symbol was a definition. if (lsym->source() != Symbol::FROM_OBJECT) res = LDPR_PREEMPTED_REG; else if (lsym->object() == static_cast(this)) res = (is_visible_from_outside(lsym) ? LDPR_PREVAILING_DEF : LDPR_PREVAILING_DEF_IRONLY); else res = (lsym->object()->pluginobj() != NULL ? LDPR_PREEMPTED_IR : LDPR_PREEMPTED_REG); } isym->resolution = res; } return LDPS_OK; } // Return TRUE if the comdat group with key COMDAT_KEY from this object // should be kept. bool Pluginobj::include_comdat_group(std::string comdat_key, Layout* layout) { std::pair ins = this->comdat_map_.insert(std::make_pair(comdat_key, false)); // If this is the first time we've seen this comdat key, ask the // layout object whether it should be included. if (ins.second) ins.first->second = layout->find_or_add_kept_section(comdat_key, NULL, 0, true, true, NULL); return ins.first->second; } // Class Sized_pluginobj. template Sized_pluginobj::Sized_pluginobj( const std::string& name, Input_file* input_file, off_t offset, off_t filesize) : Pluginobj(name, input_file, offset, filesize) { } // Read the symbols. Not used for plugin objects. template void Sized_pluginobj::do_read_symbols(Read_symbols_data*) { gold_unreachable(); } // Lay out the input sections. Not used for plugin objects. template void Sized_pluginobj::do_layout(Symbol_table*, Layout*, Read_symbols_data*) { gold_unreachable(); } // Add the symbols to the symbol table. template void Sized_pluginobj::do_add_symbols(Symbol_table* symtab, Read_symbols_data*, Layout* layout) { const int sym_size = elfcpp::Elf_sizes::sym_size; unsigned char symbuf[sym_size]; elfcpp::Sym sym(symbuf); elfcpp::Sym_write osym(symbuf); typedef typename elfcpp::Elf_types::Elf_WXword Elf_size_type; this->symbols_.resize(this->nsyms_); for (int i = 0; i < this->nsyms_; ++i) { const struct ld_plugin_symbol *isym = &this->syms_[i]; const char* name = isym->name; const char* ver = isym->version; elfcpp::Elf_Half shndx; elfcpp::STB bind; elfcpp::STV vis; if (name != NULL && name[0] == '\0') name = NULL; if (ver != NULL && ver[0] == '\0') ver = NULL; switch (isym->def) { case LDPK_WEAKDEF: case LDPK_WEAKUNDEF: bind = elfcpp::STB_WEAK; break; case LDPK_DEF: case LDPK_UNDEF: case LDPK_COMMON: default: bind = elfcpp::STB_GLOBAL; break; } switch (isym->def) { case LDPK_DEF: case LDPK_WEAKDEF: shndx = elfcpp::SHN_ABS; break; case LDPK_COMMON: shndx = elfcpp::SHN_COMMON; break; case LDPK_UNDEF: case LDPK_WEAKUNDEF: default: shndx = elfcpp::SHN_UNDEF; break; } switch (isym->visibility) { case LDPV_PROTECTED: vis = elfcpp::STV_DEFAULT; break; case LDPV_INTERNAL: vis = elfcpp::STV_DEFAULT; break; case LDPV_HIDDEN: vis = elfcpp::STV_DEFAULT; break; case LDPV_DEFAULT: default: vis = elfcpp::STV_DEFAULT; break; } if (isym->comdat_key != NULL && isym->comdat_key[0] != '\0' && !this->include_comdat_group(isym->comdat_key, layout)) shndx = elfcpp::SHN_UNDEF; osym.put_st_name(0); osym.put_st_value(0); osym.put_st_size(static_cast(isym->size)); osym.put_st_info(bind, elfcpp::STT_NOTYPE); osym.put_st_other(vis, 0); osym.put_st_shndx(shndx); this->symbols_[i] = symtab->add_from_pluginobj(this, name, ver, &sym); } } // Get the size of a section. Not used for plugin objects. template uint64_t Sized_pluginobj::do_section_size(unsigned int) { gold_unreachable(); return 0; } // Get the name of a section. Not used for plugin objects. template std::string Sized_pluginobj::do_section_name(unsigned int) { gold_unreachable(); return std::string(); } // Return a view of the contents of a section. Not used for plugin objects. template Object::Location Sized_pluginobj::do_section_contents(unsigned int) { Location loc(0, 0); gold_unreachable(); return loc; } // Return section flags. Not used for plugin objects. template uint64_t Sized_pluginobj::do_section_flags(unsigned int) { gold_unreachable(); return 0; } // Return section entsize. Not used for plugin objects. template uint64_t Sized_pluginobj::do_section_entsize(unsigned int) { gold_unreachable(); return 0; } // Return section address. Not used for plugin objects. template uint64_t Sized_pluginobj::do_section_address(unsigned int) { gold_unreachable(); return 0; } // Return section type. Not used for plugin objects. template unsigned int Sized_pluginobj::do_section_type(unsigned int) { gold_unreachable(); return 0; } // Return the section link field. Not used for plugin objects. template unsigned int Sized_pluginobj::do_section_link(unsigned int) { gold_unreachable(); return 0; } // Return the section link field. Not used for plugin objects. template unsigned int Sized_pluginobj::do_section_info(unsigned int) { gold_unreachable(); return 0; } // Return the section alignment. Not used for plugin objects. template uint64_t Sized_pluginobj::do_section_addralign(unsigned int) { gold_unreachable(); return 0; } // Return the Xindex structure to use. Not used for plugin objects. template Xindex* Sized_pluginobj::do_initialize_xindex() { gold_unreachable(); return NULL; } // Get symbol counts. Not used for plugin objects. template void Sized_pluginobj::do_get_global_symbol_counts(const Symbol_table*, size_t*, size_t*) const { gold_unreachable(); } // Class Plugin_finish. This task runs after all replacement files have // been added. It calls each plugin's cleanup handler. class Plugin_finish : public Task { public: Plugin_finish(Task_token* this_blocker, Task_token* next_blocker) : this_blocker_(this_blocker), next_blocker_(next_blocker) { } ~Plugin_finish() { if (this->this_blocker_ != NULL) delete this->this_blocker_; } Task_token* is_runnable() { if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked()) return this->this_blocker_; return NULL; } void locks(Task_locker* tl) { tl->add(this, this->next_blocker_); } void run(Workqueue*) { Plugin_manager* plugins = parameters->options().plugins(); gold_assert(plugins != NULL); plugins->cleanup(); } std::string get_name() const { return "Plugin_finish"; } private: Task_token* this_blocker_; Task_token* next_blocker_; }; // Class Plugin_hook. Plugin_hook::~Plugin_hook() { } // Return whether a Plugin_hook task is runnable. Task_token* Plugin_hook::is_runnable() { if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked()) return this->this_blocker_; return NULL; } // Return a Task_locker for a Plugin_hook task. We don't need any // locks here. void Plugin_hook::locks(Task_locker*) { } // Run the "all symbols read" plugin hook. void Plugin_hook::run(Workqueue* workqueue) { gold_assert(this->options_.has_plugins()); this->options_.plugins()->all_symbols_read(workqueue, this, this->input_objects_, this->symtab_, this->layout_, this->dirpath_, this->mapfile_, &this->this_blocker_); workqueue->queue_soon(new Plugin_finish(this->this_blocker_, this->next_blocker_)); } // The C interface routines called by the plugins. #ifdef ENABLE_PLUGINS // Register a claim-file handler. static enum ld_plugin_status register_claim_file(ld_plugin_claim_file_handler handler) { gold_assert(parameters->options().has_plugins()); parameters->options().plugins()->set_claim_file_handler(handler); return LDPS_OK; } // Register an all-symbols-read handler. static enum ld_plugin_status register_all_symbols_read(ld_plugin_all_symbols_read_handler handler) { gold_assert(parameters->options().has_plugins()); parameters->options().plugins()->set_all_symbols_read_handler(handler); return LDPS_OK; } // Register a cleanup handler. static enum ld_plugin_status register_cleanup(ld_plugin_cleanup_handler handler) { gold_assert(parameters->options().has_plugins()); parameters->options().plugins()->set_cleanup_handler(handler); return LDPS_OK; } // Add symbols from a plugin-claimed input file. static enum ld_plugin_status add_symbols(void* handle, int nsyms, const ld_plugin_symbol *syms) { gold_assert(parameters->options().has_plugins()); Pluginobj* obj = parameters->options().plugins()->make_plugin_object( static_cast(reinterpret_cast(handle))); if (obj == NULL) return LDPS_ERR; obj->store_incoming_symbols(nsyms, syms); return LDPS_OK; } // Get the input file information with an open (possibly re-opened) // file descriptor. static enum ld_plugin_status get_input_file(const void *handle, struct ld_plugin_input_file *file) { gold_assert(parameters->options().has_plugins()); unsigned int obj_index = static_cast(reinterpret_cast(handle)); return parameters->options().plugins()->get_input_file(obj_index, file); } // Release the input file. static enum ld_plugin_status release_input_file(const void *handle) { gold_assert(parameters->options().has_plugins()); unsigned int obj_index = static_cast(reinterpret_cast(handle)); return parameters->options().plugins()->release_input_file(obj_index); } // Get the symbol resolution info for a plugin-claimed input file. static enum ld_plugin_status get_symbols(const void * handle, int nsyms, ld_plugin_symbol* syms) { gold_assert(parameters->options().has_plugins()); Pluginobj* obj = parameters->options().plugins()->object( static_cast(reinterpret_cast(handle))); if (obj == NULL) return LDPS_ERR; return obj->get_symbol_resolution_info(nsyms, syms); } // Add a new (real) input file generated by a plugin. static enum ld_plugin_status add_input_file(char *pathname) { gold_assert(parameters->options().has_plugins()); return parameters->options().plugins()->add_input_file(pathname, false); } // Add a new (real) library required by a plugin. static enum ld_plugin_status add_input_library(char *pathname) { gold_assert(parameters->options().has_plugins()); return parameters->options().plugins()->add_input_file(pathname, true); } // Issue a diagnostic message from a plugin. static enum ld_plugin_status message(int level, const char * format, ...) { va_list args; va_start(args, format); switch (level) { case LDPL_INFO: parameters->errors()->info(format, args); break; case LDPL_WARNING: parameters->errors()->warning(format, args); break; case LDPL_ERROR: default: parameters->errors()->error(format, args); break; case LDPL_FATAL: parameters->errors()->fatal(format, args); break; } va_end(args); return LDPS_OK; } #endif // ENABLE_PLUGINS // Allocate a Pluginobj object of the appropriate size and endianness. static Pluginobj* make_sized_plugin_object(Input_file* input_file, off_t offset, off_t filesize) { Pluginobj* obj = NULL; parameters_force_valid_target(); const Target& target(parameters->target()); if (target.get_size() == 32) { if (target.is_big_endian()) #ifdef HAVE_TARGET_32_BIG obj = new Sized_pluginobj<32, true>(input_file->filename(), input_file, offset, filesize); #else gold_error(_("%s: not configured to support " "32-bit big-endian object"), input_file->filename().c_str()); #endif else #ifdef HAVE_TARGET_32_LITTLE obj = new Sized_pluginobj<32, false>(input_file->filename(), input_file, offset, filesize); #else gold_error(_("%s: not configured to support " "32-bit little-endian object"), input_file->filename().c_str()); #endif } else if (target.get_size() == 64) { if (target.is_big_endian()) #ifdef HAVE_TARGET_64_BIG obj = new Sized_pluginobj<64, true>(input_file->filename(), input_file, offset, filesize); #else gold_error(_("%s: not configured to support " "64-bit big-endian object"), input_file->filename().c_str()); #endif else #ifdef HAVE_TARGET_64_LITTLE obj = new Sized_pluginobj<64, false>(input_file->filename(), input_file, offset, filesize); #else gold_error(_("%s: not configured to support " "64-bit little-endian object"), input_file->filename().c_str()); #endif } gold_assert(obj != NULL); return obj; } } // End namespace gold.