binutils-gdb/gold/plugin.h

656 lines
17 KiB
C++

// plugin.h -- plugin manager for gold -*- C++ -*-
// Copyright (C) 2008-2018 Free Software Foundation, Inc.
// Written by Cary Coutant <ccoutant@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_PLUGIN_H
#define GOLD_PLUGIN_H
#include <list>
#include <string>
#include "object.h"
#include "plugin-api.h"
#include "workqueue.h"
namespace gold
{
class General_options;
class Input_file;
class Input_objects;
class Archive;
class Input_group;
class Symbol;
class Symbol_table;
class Layout;
class Dirsearch;
class Mapfile;
class Task;
class Task_token;
class Pluginobj;
class Plugin_rescan;
class Plugin_recorder;
// This class represents a single plugin library.
class Plugin
{
public:
Plugin(const char* filename)
: handle_(NULL),
filename_(filename),
args_(),
claim_file_handler_(NULL),
all_symbols_read_handler_(NULL),
cleanup_handler_(NULL),
new_input_handler_(NULL),
cleanup_done_(false)
{ }
~Plugin()
{ }
// Load the library and call its entry point.
void
load();
// Call the claim-file handler.
bool
claim_file(struct ld_plugin_input_file* plugin_input_file);
// Call the all-symbols-read handler.
void
all_symbols_read();
// Call the new_input handler.
void
new_input(struct ld_plugin_input_file* plugin_input_file);
// Call the cleanup handler.
void
cleanup();
// Register a claim-file handler.
void
set_claim_file_handler(ld_plugin_claim_file_handler handler)
{ this->claim_file_handler_ = handler; }
// Register an all-symbols-read handler.
void
set_all_symbols_read_handler(ld_plugin_all_symbols_read_handler handler)
{ this->all_symbols_read_handler_ = handler; }
// Register a claim-file handler.
void
set_cleanup_handler(ld_plugin_cleanup_handler handler)
{ this->cleanup_handler_ = handler; }
// Register a new_input handler.
void
set_new_input_handler(ld_plugin_new_input_handler handler)
{ this->new_input_handler_ = handler; }
// Add an argument
void
add_option(const char* arg)
{
this->args_.push_back(arg);
}
const std::string&
filename() const
{ return this->filename_; }
private:
Plugin(const Plugin&);
Plugin& operator=(const Plugin&);
// The shared library handle returned by dlopen.
void* handle_;
// The argument string given to --plugin.
std::string filename_;
// The list of argument string given to --plugin-opt.
std::vector<std::string> args_;
// The plugin's event handlers.
ld_plugin_claim_file_handler claim_file_handler_;
ld_plugin_all_symbols_read_handler all_symbols_read_handler_;
ld_plugin_cleanup_handler cleanup_handler_;
ld_plugin_new_input_handler new_input_handler_;
// TRUE if the cleanup handlers have been called.
bool cleanup_done_;
};
// A manager class for plugins.
class Plugin_manager
{
public:
Plugin_manager(const General_options& options)
: plugins_(), objects_(), deferred_layout_objects_(), input_file_(NULL),
plugin_input_file_(), rescannable_(), undefined_symbols_(),
any_claimed_(false), in_replacement_phase_(false), any_added_(false),
in_claim_file_handler_(false),
options_(options), workqueue_(NULL), task_(NULL), input_objects_(NULL),
symtab_(NULL), layout_(NULL), dirpath_(NULL), mapfile_(NULL),
this_blocker_(NULL), extra_search_path_(), lock_(NULL),
initialize_lock_(&lock_), defsym_defines_set_(),
recorder_(NULL)
{ this->current_ = plugins_.end(); }
~Plugin_manager();
// Returns true if the symbol name is used in the LHS of a defsym.
bool
is_defsym_def(const char* sym_name) const
{
return defsym_defines_set_.find(sym_name) != defsym_defines_set_.end();
}
// Add a plugin library.
void
add_plugin(const char* filename)
{ this->plugins_.push_back(new Plugin(filename)); }
// Add an argument to the current plugin.
void
add_plugin_option(const char* opt)
{
Plugin* last = this->plugins_.back();
last->add_option(opt);
}
// Load all plugin libraries.
void
load_plugins(Layout* layout);
// Call the plugin claim-file handlers in turn to see if any claim the file.
Pluginobj*
claim_file(Input_file* input_file, off_t offset, off_t filesize,
Object* elf_object);
// Get the object associated with the handle and check if it is an elf object.
// If it is not a Pluginobj, it is an elf object.
Object*
get_elf_object(const void* handle);
// True if the claim_file handler of the plugins is being called.
bool
in_claim_file_handler()
{ return in_claim_file_handler_; }
// Let the plugin manager save an archive for later rescanning.
// This takes ownership of the Archive pointer.
void
save_archive(Archive*);
// Let the plugin manager save an input group for later rescanning.
// This takes ownership of the Input_group pointer.
void
save_input_group(Input_group*);
// Call the all-symbols-read handlers.
void
all_symbols_read(Workqueue* workqueue, Task* task,
Input_objects* input_objects, Symbol_table* symtab,
Dirsearch* dirpath, Mapfile* mapfile,
Task_token** last_blocker);
// Tell the plugin manager that we've a new undefined symbol which
// may require rescanning.
void
new_undefined_symbol(Symbol*);
// Run deferred layout.
void
layout_deferred_objects();
// Call the cleanup handlers.
void
cleanup();
// Register a claim-file handler.
void
set_claim_file_handler(ld_plugin_claim_file_handler handler)
{
gold_assert(this->current_ != plugins_.end());
(*this->current_)->set_claim_file_handler(handler);
}
// Register an all-symbols-read handler.
void
set_all_symbols_read_handler(ld_plugin_all_symbols_read_handler handler)
{
gold_assert(this->current_ != plugins_.end());
(*this->current_)->set_all_symbols_read_handler(handler);
}
// Register a new_input handler.
void
set_new_input_handler(ld_plugin_new_input_handler handler)
{
gold_assert(this->current_ != plugins_.end());
(*this->current_)->set_new_input_handler(handler);
}
// Register a claim-file handler.
void
set_cleanup_handler(ld_plugin_cleanup_handler handler)
{
gold_assert(this->current_ != plugins_.end());
(*this->current_)->set_cleanup_handler(handler);
}
// Make a new Pluginobj object. This is called when the plugin calls
// the add_symbols API.
Pluginobj*
make_plugin_object(unsigned int handle);
// Return the object associated with the given HANDLE.
Object*
object(unsigned int handle) const
{
if (handle >= this->objects_.size())
return NULL;
return this->objects_[handle];
}
// Return TRUE if any input files have been claimed by a plugin
// and we are still in the initial input phase.
bool
should_defer_layout() const
{ return this->any_claimed_ && !this->in_replacement_phase_; }
// Add a regular object to the deferred layout list. These are
// objects whose layout has been deferred until after the
// replacement files have arrived.
void
add_deferred_layout_object(Relobj* obj)
{ this->deferred_layout_objects_.push_back(obj); }
// Get input file information with an open (possibly re-opened)
// file descriptor.
ld_plugin_status
get_input_file(unsigned int handle, struct ld_plugin_input_file* file);
ld_plugin_status
get_view(unsigned int handle, const void **viewp);
// Release an input file.
ld_plugin_status
release_input_file(unsigned int handle);
// Add a new input file.
ld_plugin_status
add_input_file(const char* pathname, bool is_lib);
// Set the extra library path.
ld_plugin_status
set_extra_library_path(const char* path);
// Return TRUE if we are in the replacement phase.
bool
in_replacement_phase() const
{ return this->in_replacement_phase_; }
Input_objects*
input_objects() const
{ return this->input_objects_; }
Symbol_table*
symtab()
{ return this->symtab_; }
Layout*
layout()
{ return this->layout_; }
Plugin_recorder*
recorder() const
{ return this->recorder_; }
private:
Plugin_manager(const Plugin_manager&);
Plugin_manager& operator=(const Plugin_manager&);
// Plugin_rescan is a Task which calls the private rescan method.
friend class Plugin_rescan;
// An archive or input group which may have to be rescanned if a
// plugin adds a new file.
struct Rescannable
{
bool is_archive;
union
{
Archive* archive;
Input_group* input_group;
} u;
Rescannable(Archive* archive)
: is_archive(true)
{ this->u.archive = archive; }
Rescannable(Input_group* input_group)
: is_archive(false)
{ this->u.input_group = input_group; }
};
typedef std::list<Plugin*> Plugin_list;
typedef std::vector<Object*> Object_list;
typedef std::vector<Relobj*> Deferred_layout_list;
typedef std::vector<Rescannable> Rescannable_list;
typedef std::vector<Symbol*> Undefined_symbol_list;
// Rescan archives for undefined symbols.
void
rescan(Task*);
// See whether the rescannable at index I defines SYM.
bool
rescannable_defines(size_t i, Symbol* sym);
// The list of plugin libraries.
Plugin_list plugins_;
// A pointer to the current plugin. Used while loading plugins.
Plugin_list::iterator current_;
// The list of plugin objects. The index of an item in this list
// serves as the "handle" that we pass to the plugins.
Object_list objects_;
// The list of regular objects whose layout has been deferred.
Deferred_layout_list deferred_layout_objects_;
// The file currently up for claim by the plugins.
Input_file* input_file_;
struct ld_plugin_input_file plugin_input_file_;
// A list of archives and input groups being saved for possible
// later rescanning.
Rescannable_list rescannable_;
// A list of undefined symbols found in added files.
Undefined_symbol_list undefined_symbols_;
// Whether any input files have been claimed by a plugin.
bool any_claimed_;
// Set to true after the all symbols read event; indicates that we
// are processing replacement files whose symbols should replace the
// placeholder symbols from the Pluginobj objects.
bool in_replacement_phase_;
// Whether any input files or libraries were added by a plugin.
bool any_added_;
// Set to true when the claim_file handler of a plugin is called.
bool in_claim_file_handler_;
const General_options& options_;
Workqueue* workqueue_;
Task* task_;
Input_objects* input_objects_;
Symbol_table* symtab_;
Layout* layout_;
Dirsearch* dirpath_;
Mapfile* mapfile_;
Task_token* this_blocker_;
// An extra directory to search for the libraries passed by
// add_input_library.
std::string extra_search_path_;
Lock* lock_;
Initialize_lock initialize_lock_;
// Keep track of all symbols defined by defsym.
typedef Unordered_set<std::string> Defsym_defines_set;
Defsym_defines_set defsym_defines_set_;
// Class to record plugin actions.
Plugin_recorder* recorder_;
};
// An object file claimed by a plugin. This is an abstract base class.
// The implementation is the template class Sized_pluginobj.
class Pluginobj : public Object
{
public:
typedef std::vector<Symbol*> Symbols;
Pluginobj(const std::string& name, Input_file* input_file, off_t offset,
off_t filesize);
// Fill in the symbol resolution status for the given plugin symbols.
ld_plugin_status
get_symbol_resolution_info(Symbol_table* symtab,
int nsyms,
ld_plugin_symbol* syms,
int version) const;
// Store the incoming symbols from the plugin for later processing.
void
store_incoming_symbols(int nsyms, const struct ld_plugin_symbol* syms)
{
this->nsyms_ = nsyms;
this->syms_ = syms;
}
// Return TRUE if the comdat group with key COMDAT_KEY from this object
// should be kept.
bool
include_comdat_group(std::string comdat_key, Layout* layout);
// Return the filename.
const std::string&
filename() const
{ return this->input_file()->filename(); }
// Return the file descriptor.
int
descriptor()
{ return this->input_file()->file().descriptor(); }
// Return the size of the file or archive member.
off_t
filesize()
{ return this->filesize_; }
// Return the word size of the object file.
int
elfsize() const
{ gold_unreachable(); }
// Return TRUE if this is a big-endian object file.
bool
is_big_endian() const
{ gold_unreachable(); }
protected:
// Return TRUE if this is an object claimed by a plugin.
virtual Pluginobj*
do_pluginobj()
{ return this; }
// The number of symbols provided by the plugin.
int nsyms_;
// The symbols provided by the plugin.
const struct ld_plugin_symbol* syms_;
// The entries in the symbol table for the external symbols.
Symbols symbols_;
private:
// Size of the file (or archive member).
off_t filesize_;
// Map a comdat key symbol to a boolean indicating whether the comdat
// group in this object with that key should be kept.
typedef Unordered_map<std::string, bool> Comdat_map;
Comdat_map comdat_map_;
};
// A plugin object, size-specific version.
template<int size, bool big_endian>
class Sized_pluginobj : public Pluginobj
{
public:
Sized_pluginobj(const std::string& name, Input_file* input_file,
off_t offset, off_t filesize);
// Read the symbols.
void
do_read_symbols(Read_symbols_data*);
// Lay out the input sections.
void
do_layout(Symbol_table*, Layout*, Read_symbols_data*);
// Add the symbols to the symbol table.
void
do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*);
Archive::Should_include
do_should_include_member(Symbol_table* symtab, Layout*, Read_symbols_data*,
std::string* why);
// Iterate over global symbols, calling a visitor class V for each.
void
do_for_all_global_symbols(Read_symbols_data* sd,
Library_base::Symbol_visitor_base* v);
// Iterate over local symbols, calling a visitor class V for each GOT offset
// associated with a local symbol.
void
do_for_all_local_got_entries(Got_offset_list::Visitor* v) const;
// Get the size of a section.
uint64_t
do_section_size(unsigned int shndx);
// Get the name of a section.
std::string
do_section_name(unsigned int shndx) const;
// Return a view of the contents of a section.
const unsigned char*
do_section_contents(unsigned int shndx, section_size_type* plen,
bool cache);
// Return section flags.
uint64_t
do_section_flags(unsigned int shndx);
// Return section entsize.
uint64_t
do_section_entsize(unsigned int shndx);
// Return section address.
uint64_t
do_section_address(unsigned int shndx);
// Return section type.
unsigned int
do_section_type(unsigned int shndx);
// Return the section link field.
unsigned int
do_section_link(unsigned int shndx);
// Return the section link field.
unsigned int
do_section_info(unsigned int shndx);
// Return the section alignment.
uint64_t
do_section_addralign(unsigned int shndx);
// Return the Xindex structure to use.
Xindex*
do_initialize_xindex();
// Get symbol counts.
void
do_get_global_symbol_counts(const Symbol_table*, size_t*, size_t*) const;
// Get global symbols.
const Symbols*
do_get_global_symbols() const;
// Add placeholder symbols from a claimed file.
ld_plugin_status
add_symbols_from_plugin(int nsyms, const ld_plugin_symbol* syms);
protected:
private:
};
// This Task handles handles the "all symbols read" event hook.
// The plugin may add additional input files at this time, which must
// be queued for reading.
class Plugin_hook : public Task
{
public:
Plugin_hook(const General_options& options, Input_objects* input_objects,
Symbol_table* symtab, Layout* /*layout*/, Dirsearch* dirpath,
Mapfile* mapfile, Task_token* this_blocker,
Task_token* next_blocker)
: options_(options), input_objects_(input_objects), symtab_(symtab),
dirpath_(dirpath), mapfile_(mapfile),
this_blocker_(this_blocker), next_blocker_(next_blocker)
{ }
~Plugin_hook();
// The standard Task methods.
Task_token*
is_runnable();
void
locks(Task_locker*);
void
run(Workqueue*);
std::string
get_name() const
{ return "Plugin_hook"; }
private:
const General_options& options_;
Input_objects* input_objects_;
Symbol_table* symtab_;
Dirsearch* dirpath_;
Mapfile* mapfile_;
Task_token* this_blocker_;
Task_token* next_blocker_;
};
} // End namespace gold.
#endif // !defined(GOLD_PLUGIN_H)