Retro68/binutils/gold/incremental.h
2012-03-26 21:18:29 +02:00

349 lines
10 KiB
C++

// inremental.h -- incremental linking support for gold -*- C++ -*-
// Copyright 2009 Free Software Foundation, Inc.
// Written by Mikolaj Zalewski <mikolajz@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_INCREMENTAL_H
#define GOLD_INCREMENTAL_H
#include <map>
#include <vector>
#include "elfcpp_file.h"
#include "stringpool.h"
#include "workqueue.h"
#include "fileread.h"
#include "output.h"
namespace gold
{
class Archive;
class Input_argument;
class Incremental_inputs_checker;
class Object;
class Output_section_data;
// Incremental input type as stored in .gnu_incremental_inputs.
enum Incremental_input_type
{
INCREMENTAL_INPUT_INVALID = 0,
INCREMENTAL_INPUT_OBJECT = 1,
INCREMENTAL_INPUT_ARCHIVE = 2,
INCREMENTAL_INPUT_SHARED_LIBRARY = 3,
INCREMENTAL_INPUT_SCRIPT = 4
};
// An object representing the ELF file we edit during an incremental build.
// Similar to Object or Dynobj, but operates on Output_file and contains
// method specific to file edition (TBD). This is the abstract parent class
// implemented in Sized_incremental_binary<size, big_endian> for a specific
// endianness and size.
class Incremental_binary
{
public:
Incremental_binary(Output_file* output, Target* target)
: output_(output), target_(target)
{ }
virtual
~Incremental_binary()
{ }
// Functions and types for the elfcpp::Elf_file interface. This
// permit us to use Incremental_binary as the File template parameter for
// elfcpp::Elf_file.
// The View class is returned by view. It must support a single
// method, data(). This is trivial, because Output_file::get_output_view
// does what we need.
class View
{
public:
View(const unsigned char* p)
: p_(p)
{ }
const unsigned char*
data() const
{ return this->p_; }
private:
const unsigned char* p_;
};
// Return a View.
View
view(off_t file_offset, section_size_type data_size)
{ return View(this->output_->get_input_view(file_offset, data_size)); }
// A location in the file.
struct Location
{
off_t file_offset;
off_t data_size;
Location(off_t fo, section_size_type ds)
: file_offset(fo), data_size(ds)
{ }
Location()
: file_offset(0), data_size(0)
{ }
};
// Get a View given a Location.
View view(Location loc)
{ return View(this->view(loc.file_offset, loc.data_size)); }
// Report an error.
void
error(const char* format, ...) const ATTRIBUTE_PRINTF_2;
// Find the .gnu_incremental_inputs section. It selects the first section
// of type SHT_GNU_INCREMENTAL_INPUTS. Returns false if such a section
// is not found.
bool
find_incremental_inputs_section(Location* location,
unsigned int* strtab_shndx)
{ return do_find_incremental_inputs_section(location, strtab_shndx); }
// Check the .gnu_incremental_inputs section to see whether an incremental
// build is possible.
// TODO: on success, should report what files needs to be rebuilt.
// INCREMENTAL_INPUTS is used to read the canonical form of the command line
// and read the input arguments. TODO: for items that don't need to be
// rebuilt, we should also copy the incremental input information.
virtual bool
check_inputs(Incremental_inputs* incremental_inputs)
{ return do_check_inputs(incremental_inputs); }
protected:
// Find incremental inputs section.
virtual bool
do_find_incremental_inputs_section(Location* location,
unsigned int* strtab_shndx) = 0;
// Check the .gnu_incremental_inputs section to see whether an incremental
// build is possible.
virtual bool
do_check_inputs(Incremental_inputs* incremental_inputs) = 0;
private:
// Edited output file object.
Output_file* output_;
// Target of the output file.
Target* target_;
};
template<int size, bool big_endian>
class Sized_incremental_binary : public Incremental_binary
{
public:
Sized_incremental_binary(Output_file* output,
const elfcpp::Ehdr<size, big_endian>& ehdr,
Target* target)
: Incremental_binary(output, target), elf_file_(this, ehdr)
{ }
protected:
virtual bool
do_find_incremental_inputs_section(Location* location,
unsigned int* strtab_shndx);
virtual bool
do_check_inputs(Incremental_inputs* incremental_inputs);
private:
// Output as an ELF file.
elfcpp::Elf_file<size, big_endian, Incremental_binary> elf_file_;
};
// Create an Incremental_binary object for FILE. Returns NULL is this is not
// possible, e.g. FILE is not an ELF file or has an unsupported target.
Incremental_binary*
open_incremental_binary(Output_file* file);
// Code invoked early during an incremental link that checks what files need
// to be relinked.
class Incremental_checker
{
public:
// Check if the file named OUTPUT_NAME can be linked incrementally.
// INCREMENTAL_INPUTS must have the canonical form of the command line
// and input arguments filled - at this point of linking other fields are
// probably not filled yet. TODO: for inputs that don't need to be
// rebuilt, this function should fill the incremental input information.
Incremental_checker(const char* output_name,
Incremental_inputs* incremental_inputs)
: output_name_(output_name), incremental_inputs_(incremental_inputs)
{ }
// Analyzes the output file to check if incremental linking is possible and
// what files needs to be relinked.
bool
can_incrementally_link_output_file();
private:
// Name of the output file to analyze.
const char* output_name_;
// The Incremental_inputs object. At this stage of link, only the command
// line and inputs are filled.
Incremental_inputs* incremental_inputs_;
};
// This class contains the information needed during an incremental
// build about the inputs necessary to build the .gnu_incremental_inputs.
class Incremental_inputs
{
public:
Incremental_inputs()
: lock_(new Lock()), inputs_(NULL), command_line_key_(0),
strtab_(new Stringpool())
{ }
~Incremental_inputs() { delete this->strtab_; }
// Record the command line.
void
report_command_line(int argc, const char* const* argv);
// Record the input arguments obtained from parsing the command line.
void
report_inputs(const Input_arguments& inputs)
{ this->inputs_ = &inputs; }
// Record that the input argument INPUT is an archive ARCHIVE.
void
report_archive(const Input_argument* input, Archive* archive);
// Record that the input argument INPUT is to an object OBJ.
void
report_object(const Input_argument* input, Object* obj);
// Record that the input argument INPUT is to an script SCRIPT.
void
report_script(const Input_argument* input, Timespec mtime,
Script_info* script);
// Prepare for layout. Called from Layout::finalize.
void
finalize();
// Create the content of the .gnu_incremental_inputs section.
Output_section_data*
create_incremental_inputs_section_data();
// Return the .gnu_incremental_strtab stringpool.
Stringpool*
get_stringpool()
{ return this->strtab_; }
// Return the canonical form of the command line, as will be stored in
// .gnu_incremental_strtab.
const std::string&
command_line()
{ return this->command_line_; }
// Return the input files found in the command line.
const Input_arguments*
inputs()
{ return this->inputs_; }
private:
// Code for each of the four possible variants of create_inputs_section_data.
template<int size, bool big_endian>
Output_section_data*
sized_create_inputs_section_data();
// Compute indexes in the order in which the inputs should appear in
// .gnu_incremental_inputs and put file names to the stringtable.
// This needs to be done after all the scripts are parsed.
void
finalize_inputs(Input_argument_list::const_iterator begin,
Input_argument_list::const_iterator end,
unsigned int* index);
// Additional data about an input needed for an incremental link.
// None of these pointers is owned by the structure.
struct Input_info
{
Input_info()
: type(INCREMENTAL_INPUT_INVALID), archive(NULL), filename_key(0),
index(0)
{ }
// Type of the file pointed by this argument.
Incremental_input_type type;
union
{
// Present if type == INCREMENTAL_INPUT_ARCHIVE.
Archive* archive;
// Present if type == INCREMENTAL_INPUT_OBJECT or
// INCREMENTAL_INPUT_SHARED_LIBRARY.
Object* object;
// Present if type == INCREMENTAL_INPUT_SCRIPT.
Script_info* script;
};
// Key of the filename string in the section stringtable.
Stringpool::Key filename_key;
// Position of the entry information in the output section.
unsigned int index;
// Last modification time of the file.
Timespec mtime;
};
typedef std::map<const Input_argument*, Input_info> Inputs_info_map;
// A lock guarding access to inputs_ during the first phase of linking, when
// report_ function may be called from multiple threads.
Lock* lock_;
// The list of input arguments obtained from parsing the command line.
const Input_arguments* inputs_;
// A map containing additional information about the input elements.
Inputs_info_map inputs_map_;
// Canonical form of the command line, as will be stored in
// .gnu_incremental_strtab.
std::string command_line_;
// The key of the command line string in the string pool.
Stringpool::Key command_line_key_;
// The .gnu_incremental_strtab string pool associated with the
// .gnu_incremental_inputs.
Stringpool* strtab_;
};
} // End namespace gold.
#endif // !defined(GOLD_INCREMENTAL_H)