| // compressed_output.cc -- manage compressed output sections for gold |
| |
| // Copyright 2007, 2008 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. |
| |
| #include "gold.h" |
| |
| #ifdef HAVE_ZLIB_H |
| #include <zlib.h> |
| #endif |
| |
| #include "parameters.h" |
| #include "options.h" |
| #include "compressed_output.h" |
| |
| namespace gold |
| { |
| |
| // Compress UNCOMPRESSED_DATA of size UNCOMPRESSED_SIZE. Returns true |
| // if it successfully compressed, false if it failed for any reason |
| // (including not having zlib support in the library). If it returns |
| // true, it allocates memory for the compressed data using new, and |
| // sets *COMPRESSED_DATA and *COMPRESSED_SIZE to appropriate values. |
| // It also writes a header before COMPRESSED_DATA: 4 bytes saying |
| // "ZLIB", and 8 bytes indicating the uncompressed size, in big-endian |
| // order. |
| |
| #ifdef HAVE_ZLIB_H |
| |
| static bool |
| zlib_compress(const unsigned char* uncompressed_data, |
| unsigned long uncompressed_size, |
| unsigned char** compressed_data, |
| unsigned long* compressed_size) |
| { |
| const int header_size = 12; |
| *compressed_size = uncompressed_size + uncompressed_size / 1000 + 128; |
| *compressed_data = new unsigned char[*compressed_size + header_size]; |
| |
| int compress_level; |
| if (parameters->options().optimize() >= 1) |
| compress_level = 9; |
| else |
| compress_level = 1; |
| |
| int rc = compress2(reinterpret_cast<Bytef*>(*compressed_data) + header_size, |
| compressed_size, |
| reinterpret_cast<const Bytef*>(uncompressed_data), |
| uncompressed_size, |
| compress_level); |
| if (rc == Z_OK) |
| { |
| memcpy(*compressed_data, "ZLIB", 4); |
| elfcpp::Swap_unaligned<64, true>::writeval(*compressed_data + 4, |
| uncompressed_size); |
| *compressed_size += header_size; |
| return true; |
| } |
| else |
| { |
| delete[] *compressed_data; |
| *compressed_data = NULL; |
| return false; |
| } |
| } |
| |
| #else // !defined(HAVE_ZLIB_H) |
| |
| static bool |
| zlib_compress(const unsigned char*, unsigned long, |
| unsigned char**, unsigned long*) |
| { |
| return false; |
| } |
| |
| #endif // !defined(HAVE_ZLIB_H) |
| |
| // Class Output_compressed_section. |
| |
| // Set the final data size of a compressed section. This is where |
| // we actually compress the section data. |
| |
| void |
| Output_compressed_section::set_final_data_size() |
| { |
| off_t uncompressed_size = this->postprocessing_buffer_size(); |
| |
| // (Try to) compress the data. |
| unsigned long compressed_size; |
| unsigned char* uncompressed_data = this->postprocessing_buffer(); |
| |
| // At this point the contents of all regular input sections will |
| // have been copied into the postprocessing buffer, and relocations |
| // will have been applied. Now we need to copy in the contents of |
| // anything other than a regular input section. |
| this->write_to_postprocessing_buffer(); |
| |
| bool success = false; |
| if (strcmp(this->options_->compress_debug_sections(), "zlib") == 0) |
| success = zlib_compress(uncompressed_data, uncompressed_size, |
| &this->data_, &compressed_size); |
| if (success) |
| { |
| // This converts .debug_foo to .zdebug_foo |
| this->new_section_name_ = std::string(".z") + (this->name() + 1); |
| this->set_name(this->new_section_name_.c_str()); |
| this->set_data_size(compressed_size); |
| } |
| else |
| { |
| gold_warning(_("not compressing section data: zlib error")); |
| gold_assert(this->data_ == NULL); |
| this->set_data_size(uncompressed_size); |
| } |
| } |
| |
| // Write out a compressed section. If we couldn't compress, we just |
| // write it out as normal, uncompressed data. |
| |
| void |
| Output_compressed_section::do_write(Output_file* of) |
| { |
| off_t offset = this->offset(); |
| off_t data_size = this->data_size(); |
| unsigned char* view = of->get_output_view(offset, data_size); |
| if (this->data_ == NULL) |
| memcpy(view, this->postprocessing_buffer(), data_size); |
| else |
| memcpy(view, this->data_, data_size); |
| of->write_output_view(offset, data_size, view); |
| } |
| |
| } // End namespace gold. |