From a2e4736229d6ce6f804ed26ea8d763c538de9d2c Mon Sep 17 00:00:00 2001 From: Cary Coutant Date: Mon, 12 Jul 2010 17:59:58 +0000 Subject: * compressed_output.cc (zlib_decompress): New function. (get_uncompressed_size): New function. (decompress_input_section): New function. * compressed_output.h (get_uncompressed_size): New function. (decompress_input_section): New function. * dwarf_reader.cc (Sized_dwarf_line_info::Sized_dwarf_line_info) Handle compressed debug sections. * layout.cc (is_compressed_debug_section): New function. (Layout::output_section_name): Map compressed section names to canonical names. * layout.h (is_compressed_debug_section): New function. (is_debug_info_section): Recognize compressed debug sections. * merge.cc: Include compressed_output.h. (Output_merge_data::do_add_input_section): Handle compressed debug sections. (Output_merge_string::do_add_input_section): Handle compressed debug sections. * object.cc: Include compressed_output.h. (Sized_relobj::Sized_relobj): Initialize new data members. (build_compressed_section_map): New function. (Sized_relobj::do_read_symbols): Handle compressed debug sections. * object.h (Object::section_is_compressed): New method. (Object::do_section_is_compressed): New method. (Sized_relobj::Compressed_section_map): New type. (Sized_relobj::do_section_is_compressed): New method. (Sized_relobj::compressed_sections_): New data member. * output.cc (Output_section::add_input_section): Handle compressed debug sections. * reloc.cc: Include compressed_output.h. (Sized_relobj::write_sections): Handle compressed debug sections. --- gold/ChangeLog | 33 +++++++++++++++ gold/compressed_output.cc | 105 ++++++++++++++++++++++++++++++++++++++++++++-- gold/compressed_output.h | 14 ++++++- gold/dwarf_reader.cc | 16 +++++++ gold/layout.cc | 25 ++++++++++- gold/layout.h | 5 +++ gold/merge.cc | 43 ++++++++++++++++++- gold/object.cc | 54 +++++++++++++++++++++++- gold/object.h | 40 +++++++++++++++++- gold/output.cc | 7 +++- gold/reloc.cc | 33 ++++++++++++--- 11 files changed, 358 insertions(+), 17 deletions(-) diff --git a/gold/ChangeLog b/gold/ChangeLog index 69e420f..14c5386 100644 --- a/gold/ChangeLog +++ b/gold/ChangeLog @@ -1,3 +1,36 @@ +2010-07-12 Cary Coutant + + * compressed_output.cc (zlib_decompress): New function. + (get_uncompressed_size): New function. + (decompress_input_section): New function. + * compressed_output.h (get_uncompressed_size): New function. + (decompress_input_section): New function. + * dwarf_reader.cc (Sized_dwarf_line_info::Sized_dwarf_line_info) + Handle compressed debug sections. + * layout.cc (is_compressed_debug_section): New function. + (Layout::output_section_name): Map compressed section names to + canonical names. + * layout.h (is_compressed_debug_section): New function. + (is_debug_info_section): Recognize compressed debug sections. + * merge.cc: Include compressed_output.h. + (Output_merge_data::do_add_input_section): Handle compressed + debug sections. + (Output_merge_string::do_add_input_section): Handle compressed + debug sections. + * object.cc: Include compressed_output.h. + (Sized_relobj::Sized_relobj): Initialize new data members. + (build_compressed_section_map): New function. + (Sized_relobj::do_read_symbols): Handle compressed debug sections. + * object.h (Object::section_is_compressed): New method. + (Object::do_section_is_compressed): New method. + (Sized_relobj::Compressed_section_map): New type. + (Sized_relobj::do_section_is_compressed): New method. + (Sized_relobj::compressed_sections_): New data member. + * output.cc (Output_section::add_input_section): Handle compressed + debug sections. + * reloc.cc: Include compressed_output.h. + (Sized_relobj::write_sections): Handle compressed debug sections. + 2010-07-08 Cary Coutant * resolve.cc (Symbol_table::resolve): Remember whether undef was diff --git a/gold/compressed_output.cc b/gold/compressed_output.cc index a0f8ed1..16d9129 100644 --- a/gold/compressed_output.cc +++ b/gold/compressed_output.cc @@ -1,6 +1,6 @@ -// compressed_output.cc -- manage compressed output sections for gold +// compressed_output.cc -- manage compressed debug sections for gold -// Copyright 2007, 2008 Free Software Foundation, Inc. +// Copyright 2007, 2008, 2010 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -33,6 +33,8 @@ namespace gold { +#ifdef HAVE_ZLIB_H + // 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 @@ -42,8 +44,6 @@ namespace gold // "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, @@ -81,6 +81,49 @@ zlib_compress(const unsigned char* uncompressed_data, } } +// Decompress COMPRESSED_DATA of size COMPRESSED_SIZE, into a buffer +// UNCOMPRESSED_DATA of size UNCOMPRESSED_SIZE. Returns TRUE if it +// decompressed successfully, false if it failed. The buffer, of +// appropriate size, is provided by the caller, and is typically part +// of the memory-mapped output file. + +static bool +zlib_decompress(const unsigned char* compressed_data, + unsigned long compressed_size, + unsigned char* uncompressed_data, + unsigned long uncompressed_size) +{ + z_stream strm; + int rc; + + /* It is possible the section consists of several compressed + buffers concatenated together, so we uncompress in a loop. */ + strm.zalloc = NULL; + strm.zfree = NULL; + strm.opaque = NULL; + strm.avail_in = compressed_size; + strm.next_in = const_cast(compressed_data); + strm.avail_out = uncompressed_size; + + rc = inflateInit(&strm); + while (strm.avail_in > 0) + { + if (rc != Z_OK) + return false; + strm.next_out = ((Bytef*) uncompressed_data + + (uncompressed_size - strm.avail_out)); + rc = inflate(&strm, Z_FINISH); + if (rc != Z_STREAM_END) + return false; + rc = inflateReset(&strm); + } + rc = inflateEnd(&strm); + if (rc != Z_OK || strm.avail_out != 0) + return false; + + return true; +} + #else // !defined(HAVE_ZLIB_H) static bool @@ -90,8 +133,62 @@ zlib_compress(const unsigned char*, unsigned long, return false; } +static bool +zlib_decompress(const unsigned char*, unsigned long, + unsigned char**, unsigned long*) +{ + return false; +} + #endif // !defined(HAVE_ZLIB_H) +// Read the compression header of a compressed debug section and return +// the uncompressed size. + +uint64_t +get_uncompressed_size(const unsigned char* compressed_data, + section_size_type compressed_size) +{ + const unsigned int zlib_header_size = 12; + + /* Verify the compression header. Currently, we support only zlib + compression, so it should be "ZLIB" followed by the uncompressed + section size, 8 bytes in big-endian order. */ + if (compressed_size >= zlib_header_size + && strncmp(reinterpret_cast(compressed_data), + "ZLIB", 4) == 0) + return elfcpp::Swap_unaligned<64, true>::readval(compressed_data + 4); + return -1ULL; +} + +// Decompress a compressed debug section directly into the output file. + +bool +decompress_input_section(const unsigned char* compressed_data, + unsigned long compressed_size, + unsigned char* uncompressed_data, + unsigned long uncompressed_size) +{ + const unsigned int zlib_header_size = 12; + + /* Verify the compression header. Currently, we support only zlib + compression, so it should be "ZLIB" followed by the uncompressed + section size, 8 bytes in big-endian order. */ + if (compressed_size >= zlib_header_size + && strncmp(reinterpret_cast(compressed_data), + "ZLIB", 4) == 0) + { + unsigned long uncompressed_size_check = + elfcpp::Swap_unaligned<64, true>::readval(compressed_data + 4); + gold_assert(uncompressed_size_check == uncompressed_size); + return zlib_decompress(compressed_data + zlib_header_size, + compressed_size - zlib_header_size, + uncompressed_data, + uncompressed_size); + } + return false; +} + // Class Output_compressed_section. // Set the final data size of a compressed section. This is where diff --git a/gold/compressed_output.h b/gold/compressed_output.h index 11b2762..2d6ebd9 100644 --- a/gold/compressed_output.h +++ b/gold/compressed_output.h @@ -1,6 +1,6 @@ // compressed_output.h -- compressed output sections for gold -*- C++ -*- -// Copyright 2007, 2008 Free Software Foundation, Inc. +// Copyright 2007, 2008, 2010 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -37,6 +37,18 @@ namespace gold class General_options; +// Read the compression header of a compressed debug section and return +// the uncompressed size. + +extern uint64_t +get_uncompressed_size(const unsigned char*, section_size_type); + +// Decompress a compressed debug section directly into the output file. + +extern bool +decompress_input_section(const unsigned char*, unsigned long, unsigned char*, + unsigned long); + // This is used for a section whose data should be compressed. It is // a regular Output_section which computes its contents into a buffer // and then postprocesses it. diff --git a/gold/dwarf_reader.cc b/gold/dwarf_reader.cc index 4062fe6..c0188fb 100644 --- a/gold/dwarf_reader.cc +++ b/gold/dwarf_reader.cc @@ -32,6 +32,7 @@ #include "reloc.h" #include "dwarf_reader.h" #include "int_encoding.h" +#include "compressed_output.h" namespace gold { @@ -80,6 +81,21 @@ Sized_dwarf_line_info::Sized_dwarf_line_info(Object* object, if (this->buffer_ == NULL) return; + section_size_type uncompressed_size = 0; + unsigned char* uncompressed_data = NULL; + if (object->section_is_compressed(debug_shndx, &uncompressed_size)) + { + uncompressed_data = new unsigned char[uncompressed_size]; + if (!decompress_input_section(this->buffer_, + this->buffer_end_ - this->buffer_, + uncompressed_data, + uncompressed_size)) + object->error(_("could not decompress section %s"), + object->section_name(debug_shndx).c_str()); + this->buffer_ = uncompressed_data; + this->buffer_end_ = this->buffer_ + uncompressed_size; + } + // Find the relocation section for ".debug_line". // We expect these for relobjs (.o's) but not dynobjs (.so's). bool got_relocs = false; diff --git a/gold/layout.cc b/gold/layout.cc index 9310961..b22a3bd 100644 --- a/gold/layout.cc +++ b/gold/layout.cc @@ -944,7 +944,16 @@ Layout::section_flags_to_segment(elfcpp::Elf_Xword flags) static bool is_compressible_debug_section(const char* secname) { - return (strncmp(secname, ".debug", sizeof(".debug") - 1) == 0); + return (is_prefix_of(".debug", secname)); +} + +// We may see compressed debug sections in input files. Return TRUE +// if this is the name of a compressed debug section. + +bool +is_compressed_debug_section(const char* secname) +{ + return (is_prefix_of(".zdebug", secname)); } // Make a new Output_section, and attach it to segments as @@ -3772,6 +3781,20 @@ Layout::output_section_name(const char* name, size_t* plen) } } + // Compressed debug sections should be mapped to the corresponding + // uncompressed section. + if (is_compressed_debug_section(name)) + { + size_t len = strlen(name); + char *uncompressed_name = new char[len]; + uncompressed_name[0] = '.'; + gold_assert(name[0] == '.' && name[1] == 'z'); + strncpy(&uncompressed_name[1], &name[2], len - 2); + uncompressed_name[len - 1] = '\0'; + *plen = len - 1; + return uncompressed_name; + } + return name; } diff --git a/gold/layout.h b/gold/layout.h index 55ad7a6..60ae114 100644 --- a/gold/layout.h +++ b/gold/layout.h @@ -59,6 +59,10 @@ class Output_reduced_debug_info_section; class Eh_frame; class Target; +// Return TRUE if SECNAME is the name of a compressed debug section. +extern bool +is_compressed_debug_section(const char* secname); + // This task function handles mapping the input sections to output // sections and laying them out in memory. @@ -451,6 +455,7 @@ class Layout { // Debugging sections can only be recognized by name. return (strncmp(name, ".debug", sizeof(".debug") - 1) == 0 + || strncmp(name, ".zdebug", sizeof(".zdebug") - 1) == 0 || strncmp(name, ".gnu.linkonce.wi.", sizeof(".gnu.linkonce.wi.") - 1) == 0 || strncmp(name, ".line", sizeof(".line") - 1) == 0 diff --git a/gold/merge.cc b/gold/merge.cc index 6e44ddd..ec11c90 100644 --- a/gold/merge.cc +++ b/gold/merge.cc @@ -1,6 +1,6 @@ // merge.cc -- handle section merging for gold -// Copyright 2006, 2007, 2008 Free Software Foundation, Inc. +// Copyright 2006, 2007, 2008, 2010 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -26,6 +26,7 @@ #include #include "merge.h" +#include "compressed_output.h" namespace gold { @@ -404,12 +405,29 @@ bool Output_merge_data::do_add_input_section(Relobj* object, unsigned int shndx) { section_size_type len; + section_size_type uncompressed_size = 0; + unsigned char* uncompressed_data = NULL; const unsigned char* p = object->section_contents(shndx, &len, false); + if (object->section_is_compressed(shndx, &uncompressed_size)) + { + uncompressed_data = new unsigned char[uncompressed_size]; + if (!decompress_input_section(p, len, uncompressed_data, + uncompressed_size)) + object->error(_("could not decompress section %s"), + object->section_name(shndx).c_str()); + p = uncompressed_data; + len = uncompressed_size; + } + section_size_type entsize = convert_to_section_size_type(this->entsize()); if (len % entsize != 0) - return false; + { + if (uncompressed_data != NULL) + delete[] uncompressed_data; + return false; + } this->input_count_ += len / entsize; @@ -438,6 +456,9 @@ Output_merge_data::do_add_input_section(Relobj* object, unsigned int shndx) if (this->keeps_input_sections()) record_input_section(object, shndx); + if (uncompressed_data != NULL) + delete[] uncompressed_data; + return true; } @@ -495,8 +516,21 @@ Output_merge_string::do_add_input_section(Relobj* object, unsigned int shndx) { section_size_type len; + section_size_type uncompressed_size = 0; + unsigned char* uncompressed_data = NULL; const unsigned char* pdata = object->section_contents(shndx, &len, false); + if (object->section_is_compressed(shndx, &uncompressed_size)) + { + uncompressed_data = new unsigned char[uncompressed_size]; + if (!decompress_input_section(pdata, len, uncompressed_data, + uncompressed_size)) + object->error(_("could not decompress section %s"), + object->section_name(shndx).c_str()); + pdata = uncompressed_data; + len = uncompressed_size; + } + const Char_type* p = reinterpret_cast(pdata); const Char_type* pend = p + len / sizeof(Char_type); @@ -504,6 +538,8 @@ Output_merge_string::do_add_input_section(Relobj* object, { object->error(_("mergeable string section length not multiple of " "character size")); + if (uncompressed_data != NULL) + delete[] uncompressed_data; return false; } @@ -545,6 +581,9 @@ Output_merge_string::do_add_input_section(Relobj* object, if (this->keeps_input_sections()) record_input_section(object, shndx); + if (uncompressed_data != NULL) + delete[] uncompressed_data; + return true; } diff --git a/gold/object.cc b/gold/object.cc index b034ee2..ed87b1a 100644 --- a/gold/object.cc +++ b/gold/object.cc @@ -39,6 +39,7 @@ #include "object.h" #include "dynobj.h" #include "plugin.h" +#include "compressed_output.h" namespace gold { @@ -367,7 +368,10 @@ Sized_relobj::Sized_relobj( local_got_offsets_(), kept_comdat_sections_(), has_eh_frame_(false), - discarded_eh_frame_shndx_(-1U) + discarded_eh_frame_shndx_(-1U), + deferred_layout_(), + deferred_layout_relocs_(), + compressed_sections_() { } @@ -495,6 +499,50 @@ Sized_relobj::find_eh_frame( return false; } +// Build a table for any compressed debug sections, mapping each section index +// to the uncompressed size. + +template +Compressed_section_map* +build_compressed_section_map( + const unsigned char* pshdrs, + unsigned int shnum, + const char* names, + section_size_type names_size, + Sized_relobj* obj) +{ + Compressed_section_map* uncompressed_sizes = new Compressed_section_map(); + const unsigned int shdr_size = elfcpp::Elf_sizes::shdr_size; + const unsigned char* p = pshdrs + shdr_size; + for (unsigned int i = 1; i < shnum; ++i, p += shdr_size) + { + typename elfcpp::Shdr shdr(p); + if (shdr.get_sh_type() == elfcpp::SHT_PROGBITS + && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0) + { + if (shdr.get_sh_name() >= names_size) + { + obj->error(_("bad section name offset for section %u: %lu"), + i, static_cast(shdr.get_sh_name())); + continue; + } + + const char* name = names + shdr.get_sh_name(); + if (is_compressed_debug_section(name)) + { + section_size_type len; + const unsigned char* contents = + obj->section_contents(i, &len, false); + uint64_t uncompressed_size = get_uncompressed_size(contents, len); + if (uncompressed_size != -1ULL) + (*uncompressed_sizes)[i] = + convert_to_section_size_type(uncompressed_size); + } + } + } + return uncompressed_sizes; +} + // Read the sections and symbols from an object file. template @@ -514,6 +562,10 @@ Sized_relobj::do_read_symbols(Read_symbols_data* sd) if (this->find_eh_frame(pshdrs, names, sd->section_names_size)) this->has_eh_frame_ = true; } + if (memmem(names, sd->section_names_size, ".zdebug_", 8) != NULL) + this->compressed_sections_ = + build_compressed_section_map(pshdrs, this->shnum(), names, + sd->section_names_size, this); sd->symbols = NULL; sd->symbols_size = 0; diff --git a/gold/object.h b/gold/object.h index bc2b558..f60d909 100644 --- a/gold/object.h +++ b/gold/object.h @@ -518,6 +518,13 @@ class Object set_no_export(bool value) { this->no_export_ = value; } + // Return TRUE if the section is a compressed debug section, and set + // *UNCOMPRESSED_SIZE to the size of the uncompressed data. + bool + section_is_compressed(unsigned int shndx, + section_size_type* uncompressed_size) const + { return this->do_section_is_compressed(shndx, uncompressed_size); } + protected: // Returns NULL for Objects that are not plugin objects. This method // is overridden in the Pluginobj class. @@ -628,6 +635,12 @@ class Object bool handle_split_stack_section(const char* name); + // Return TRUE if the section is a compressed debug section, and set + // *UNCOMPRESSED_SIZE to the size of the uncompressed data. + virtual bool + do_section_is_compressed(unsigned int, section_size_type*) const + { return false; } + private: // This class may not be copied. Object(const Object&); @@ -1406,6 +1419,10 @@ class Reloc_symbol_changes std::vector vec_; }; +// Type for mapping section index to uncompressed size. + +typedef std::map Compressed_section_map; + // A regular object file. This is size and endian specific. template @@ -1781,7 +1798,26 @@ class Sized_relobj : public Relobj void set_output_local_symbol_count(unsigned int value) { this->output_local_symbol_count_ = value; } - + + // Return TRUE if the section is a compressed debug section, and set + // *UNCOMPRESSED_SIZE to the size of the uncompressed data. + bool + do_section_is_compressed(unsigned int shndx, + section_size_type* uncompressed_size) const + { + if (this->compressed_sections_ == NULL) + return false; + Compressed_section_map::const_iterator p = + this->compressed_sections_->find(shndx); + if (p != this->compressed_sections_->end()) + { + if (uncompressed_size != NULL) + *uncompressed_size = p->second; + return true; + } + return false; + } + private: // For convenience. typedef Sized_relobj This; @@ -2024,6 +2060,8 @@ class Sized_relobj : public Relobj std::vector deferred_layout_; // The list of relocation sections whose layout was deferred. std::vector deferred_layout_relocs_; + // For compressed debug sections, map section index to uncompressed size. + Compressed_section_map* compressed_sections_; }; // A class to manage the list of all objects. diff --git a/gold/output.cc b/gold/output.cc index 329a4be..3ac8a3d 100644 --- a/gold/output.cc +++ b/gold/output.cc @@ -2086,8 +2086,13 @@ Output_section::add_input_section(Layout* layout, } } + section_size_type input_section_size = shdr.get_sh_size(); + section_size_type uncompressed_size; + if (object->section_is_compressed(shndx, &uncompressed_size)) + input_section_size = uncompressed_size; + this->set_current_data_size_for_child(aligned_offset_in_section - + shdr.get_sh_size()); + + input_section_size); // We need to keep track of this section if we are already keeping // track of sections, or if we are relaxing. Also, if this is a diff --git a/gold/reloc.cc b/gold/reloc.cc index 8879f0a..9f7355e 100644 --- a/gold/reloc.cc +++ b/gold/reloc.cc @@ -32,6 +32,7 @@ #include "target-reloc.h" #include "reloc.h" #include "icf.h" +#include "compressed_output.h" namespace gold { @@ -732,10 +733,17 @@ Sized_relobj::write_sections(const unsigned char* pshdrs, off_t view_start; section_size_type view_size; + bool must_decompress = false; if (output_offset != invalid_address) { view_start = output_section_offset + output_offset; view_size = convert_to_section_size_type(shdr.get_sh_size()); + section_size_type uncompressed_size; + if (this->section_is_compressed(i, &uncompressed_size)) + { + view_size = uncompressed_size; + must_decompress = true; + } } else { @@ -754,7 +762,7 @@ Sized_relobj::write_sections(const unsigned char* pshdrs, { unsigned char* buffer = os->postprocessing_buffer(); view = buffer + view_start; - if (output_offset != invalid_address) + if (output_offset != invalid_address && !must_decompress) { off_t sh_offset = shdr.get_sh_offset(); if (!rm.empty() && rm.back().file_offset > sh_offset) @@ -770,14 +778,27 @@ Sized_relobj::write_sections(const unsigned char* pshdrs, else { view = of->get_output_view(view_start, view_size); - off_t sh_offset = shdr.get_sh_offset(); - if (!rm.empty() && rm.back().file_offset > sh_offset) - is_sorted = false; - rm.push_back(File_read::Read_multiple_entry(sh_offset, - view_size, view)); + if (!must_decompress) + { + off_t sh_offset = shdr.get_sh_offset(); + if (!rm.empty() && rm.back().file_offset > sh_offset) + is_sorted = false; + rm.push_back(File_read::Read_multiple_entry(sh_offset, + view_size, view)); + } } } + if (must_decompress) + { + // Read and decompress the section. + section_size_type len; + const unsigned char* p = this->section_contents(i, &len, false); + if (!decompress_input_section(p, len, view, view_size)) + this->error(_("could not decompress section %s"), + this->section_name(i).c_str()); + } + pvs->view = view; pvs->address = os->address(); if (output_offset != invalid_address) -- cgit v1.1