| 1 | // reduced_debug_output.h -- reduce debugging information -*- C++ -*- |
| 2 | |
| 3 | // Copyright (C) 2008-2020 Free Software Foundation, Inc. |
| 4 | // Written by Caleb Howe <cshowe@google.com>. |
| 5 | |
| 6 | // This file is part of gold. |
| 7 | |
| 8 | // This program is free software; you can redistribute it and/or modify |
| 9 | // it under the terms of the GNU General Public License as published by |
| 10 | // the Free Software Foundation; either version 3 of the License, or |
| 11 | // (at your option) any later version. |
| 12 | |
| 13 | // This program is distributed in the hope that it will be useful, |
| 14 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | // GNU General Public License for more details. |
| 17 | |
| 18 | // You should have received a copy of the GNU General Public License |
| 19 | // along with this program; if not, write to the Free Software |
| 20 | // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| 21 | // MA 02110-1301, USA. |
| 22 | |
| 23 | // Reduce the size of the debug sections by emitting only debug line number |
| 24 | // information. We still need to emit skeleton debug_info and debug_abbrev |
| 25 | // sections for standard tools to parse the debug information correctly. These |
| 26 | // classes remove all debug information entries from the .debug_info section |
| 27 | // except for those describing compilation units as these DIEs contain |
| 28 | // references to the debug line information needed by most parsers. |
| 29 | |
| 30 | #ifndef GOLD_REDUCED_DEBUG_OUTPUT_H |
| 31 | #define GOLD_REDUCED_DEBUG_OUTPUT_H |
| 32 | |
| 33 | #include <map> |
| 34 | #include <utility> |
| 35 | #include <vector> |
| 36 | |
| 37 | #include "output.h" |
| 38 | |
| 39 | namespace gold |
| 40 | { |
| 41 | |
| 42 | class Output_reduced_debug_abbrev_section : public Output_section |
| 43 | { |
| 44 | public: |
| 45 | Output_reduced_debug_abbrev_section(const char* name, elfcpp::Elf_Word flags, |
| 46 | elfcpp::Elf_Xword type) |
| 47 | : Output_section(name, flags, type), sized_(false), |
| 48 | abbrev_count_(0), failed_(false) |
| 49 | { this->set_requires_postprocessing(); } |
| 50 | |
| 51 | unsigned char* get_new_abbrev(uint64_t* abbrev_number, |
| 52 | uint64_t abbrev_offset); |
| 53 | |
| 54 | protected: |
| 55 | // Set the final data size. |
| 56 | void |
| 57 | set_final_data_size(); |
| 58 | |
| 59 | // Write out the new debug abbreviations |
| 60 | void |
| 61 | do_write(Output_file*); |
| 62 | |
| 63 | private: |
| 64 | void |
| 65 | failed(std::string reason) |
| 66 | { |
| 67 | gold_warning("%s", reason.c_str()); |
| 68 | failed_ = true; |
| 69 | } |
| 70 | |
| 71 | // The reduced debug abbreviations |
| 72 | std::vector<unsigned char> data_; |
| 73 | |
| 74 | // We map the abbreviation table offset and abbreviation number of the |
| 75 | // old abbreviation to the number and size of the new abbreviation. |
| 76 | std::map<std::pair<uint64_t, uint64_t>, |
| 77 | std::pair<uint64_t, uint64_t> > abbrev_mapping_; |
| 78 | |
| 79 | bool sized_; |
| 80 | |
| 81 | // The count of abbreviations in the output data |
| 82 | int abbrev_count_; |
| 83 | |
| 84 | // Whether or not the debug reduction has failed for any reason |
| 85 | bool failed_; |
| 86 | }; |
| 87 | |
| 88 | class Output_reduced_debug_info_section : public Output_section |
| 89 | { |
| 90 | public: |
| 91 | Output_reduced_debug_info_section(const char* name, elfcpp::Elf_Word flags, |
| 92 | elfcpp::Elf_Xword type) |
| 93 | : Output_section(name, flags, type), failed_(false) |
| 94 | { this->set_requires_postprocessing(); } |
| 95 | |
| 96 | void |
| 97 | set_abbreviations(Output_reduced_debug_abbrev_section* abbrevs) |
| 98 | { associated_abbrev_ = abbrevs; } |
| 99 | |
| 100 | protected: |
| 101 | // Set the final data size. |
| 102 | void |
| 103 | set_final_data_size(); |
| 104 | |
| 105 | // Write out the new debug info |
| 106 | void |
| 107 | do_write(Output_file*); |
| 108 | |
| 109 | private: |
| 110 | void |
| 111 | failed(std::string reason) |
| 112 | { |
| 113 | gold_warning("%s", reason.c_str()); |
| 114 | this->failed_ = true; |
| 115 | } |
| 116 | |
| 117 | // Given a pointer to the beginning of a die and the beginning of the |
| 118 | // associated abbreviation fills in die_end with the end of the information |
| 119 | // entry. If successful returns true. Get_die_end also takes a pointer to |
| 120 | // the end of the buffer containing the die. If die_end would be beyond the |
| 121 | // end of the buffer, or if an unsupported dwarf form is encountered returns |
| 122 | // false. |
| 123 | bool |
| 124 | get_die_end(unsigned char* die, unsigned char* abbrev, |
| 125 | unsigned char** die_end, unsigned char* buffer_end, |
| 126 | int address_size, bool is64); |
| 127 | |
| 128 | // The reduced debug info |
| 129 | std::vector<unsigned char> data_; |
| 130 | |
| 131 | // Each debug info section needs to be associated with a debug abbrev section |
| 132 | Output_reduced_debug_abbrev_section* associated_abbrev_; |
| 133 | |
| 134 | // Whether or not the debug reduction has failed for any reason |
| 135 | bool failed_; |
| 136 | }; |
| 137 | |
| 138 | } // End namespace gold. |
| 139 | |
| 140 | #endif // !defined(GOLD_REDUCED_DEBUG_OUTPUT_H) |