138 lines
3.9 KiB
C
138 lines
3.9 KiB
C
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// compressed_output.h -- compressed output sections for gold -*- C++ -*-
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// Copyright 2007 Free Software Foundation, Inc.
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// Written by Ian Lance Taylor <iant@google.com>.
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// This file is part of gold.
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// This program is free software; you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation; either version 3 of the License, or
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// (at your option) any later version.
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// You should have received a copy of the GNU General Public License
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// along with this program; if not, write to the Free Software
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// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
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// MA 02110-1301, USA.
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// We support compressing .debug_* sections on output. (And,
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// potentially one day, other sections.) This is a form of
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// relaxation. This file adds support for merging and emitting the
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// compressed sections.
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#ifndef GOLD_COMPRESSED_OUTPUT_H
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#define GOLD_COMPRESSED_OUTPUT_H
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#include <string>
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#include <vector>
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#include "output.h"
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#include "merge.h"
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namespace gold
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{
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class General_options;
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// This is used for compressing a section before emitting it in the
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// output file. This only works for unloaded sections, since it
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// assumes the final section contents are available at
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// set_final_data_size() time. For loaded sections (those that end up
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// in segments), this is not true; relocations are applied after
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// set_final_data_size() is called. However, for unloaded sections,
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// we can -- and do -- postpone calling finalize_data_size() until
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// after relocations are applies.
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class Output_compressed_section_data : public Output_section_data
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{
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public:
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Output_compressed_section_data(uint64_t addralign,
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const General_options& options)
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: Output_section_data(addralign), options_(options), data_(NULL)
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{ }
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protected:
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// Add an input section.
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bool
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do_add_input_section(Relobj* object, unsigned int shndx);
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// Set the final data size.
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void
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set_final_data_size();
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// Change the name of the output section to reflect it's compressed.
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const char*
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do_modified_output_section_name(const char* name);
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// Write the data to the file.
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void
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do_write(Output_file*);
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private:
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struct Object_entry
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{
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Relobj* object;
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unsigned int shndx;
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const unsigned char* contents;
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off_t length;
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Object_entry(Relobj* o, unsigned int s)
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: object(o), shndx(s), contents(NULL), length(0)
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{ }
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};
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const General_options& options_;
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std::vector<Object_entry> objects_;
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char* data_;
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std::string new_section_name_;
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};
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// This is a special case for when the output section is a string
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// section and does not have any relocations to apply to it.
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template<typename Char_type>
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class Output_compressed_string : public Output_merge_string<Char_type>
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{
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public:
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Output_compressed_string(uint64_t addralign,
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const General_options& options)
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: Output_merge_string<Char_type>(addralign),
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options_(options), compressed_data_(NULL)
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{ }
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~Output_compressed_string()
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{ delete[] compressed_data_; }
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protected:
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// Add an input section.
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bool
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do_add_input_section(Relobj* object, unsigned int shndx);
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// Set the final data size. Also compresses the buffer.
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void
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set_final_data_size();
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// Change the name of the output section to reflect it's compressed.
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const char*
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do_modified_output_section_name(const char* name);
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// Write the data to the file.
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void
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do_write(Output_file*);
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private:
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const General_options& options_;
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char* compressed_data_;
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// This is just a buffer to store the section name in "permanent" storage.
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std::string new_section_name_;
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};
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} // End namespace gold.
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#endif // !defined(GOLD_COMPRESSED_OUTPUT_H)
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