mirror of
https://github.com/darlinghq/darling-gdb.git
synced 2024-12-05 02:47:05 +00:00
91d6fa6a03
Fix up all warnings generated by the addition of this switch.
879 lines
28 KiB
C++
879 lines
28 KiB
C++
// dwarf_reader.cc -- parse dwarf2/3 debug information
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// Copyright 2007, 2008, 2009 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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#include "gold.h"
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#include <algorithm>
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#include <vector>
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#include "elfcpp_swap.h"
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#include "dwarf.h"
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#include "object.h"
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#include "parameters.h"
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#include "reloc.h"
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#include "dwarf_reader.h"
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#include "int_encoding.h"
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namespace gold {
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struct LineStateMachine
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{
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int file_num;
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uint64_t address;
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int line_num;
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int column_num;
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unsigned int shndx; // the section address refers to
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bool is_stmt; // stmt means statement.
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bool basic_block;
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bool end_sequence;
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};
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static void
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ResetLineStateMachine(struct LineStateMachine* lsm, bool default_is_stmt)
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{
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lsm->file_num = 1;
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lsm->address = 0;
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lsm->line_num = 1;
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lsm->column_num = 0;
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lsm->shndx = -1U;
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lsm->is_stmt = default_is_stmt;
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lsm->basic_block = false;
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lsm->end_sequence = false;
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}
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template<int size, bool big_endian>
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Sized_dwarf_line_info<size, big_endian>::Sized_dwarf_line_info(Object* object,
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unsigned int read_shndx)
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: data_valid_(false), buffer_(NULL), symtab_buffer_(NULL),
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directories_(), files_(), current_header_index_(-1)
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{
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unsigned int debug_shndx;
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for (debug_shndx = 0; debug_shndx < object->shnum(); ++debug_shndx)
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// FIXME: do this more efficiently: section_name() isn't super-fast
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if (object->section_name(debug_shndx) == ".debug_line")
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{
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section_size_type buffer_size;
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this->buffer_ = object->section_contents(debug_shndx, &buffer_size,
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false);
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this->buffer_end_ = this->buffer_ + buffer_size;
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break;
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}
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if (this->buffer_ == NULL)
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return;
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// Find the relocation section for ".debug_line".
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// We expect these for relobjs (.o's) but not dynobjs (.so's).
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bool got_relocs = false;
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for (unsigned int reloc_shndx = 0;
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reloc_shndx < object->shnum();
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++reloc_shndx)
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{
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unsigned int reloc_sh_type = object->section_type(reloc_shndx);
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if ((reloc_sh_type == elfcpp::SHT_REL
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|| reloc_sh_type == elfcpp::SHT_RELA)
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&& object->section_info(reloc_shndx) == debug_shndx)
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{
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got_relocs = this->track_relocs_.initialize(object, reloc_shndx,
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reloc_sh_type);
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break;
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}
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}
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// Finally, we need the symtab section to interpret the relocs.
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if (got_relocs)
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{
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unsigned int symtab_shndx;
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for (symtab_shndx = 0; symtab_shndx < object->shnum(); ++symtab_shndx)
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if (object->section_type(symtab_shndx) == elfcpp::SHT_SYMTAB)
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{
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this->symtab_buffer_ = object->section_contents(
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symtab_shndx, &this->symtab_buffer_size_, false);
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break;
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}
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if (this->symtab_buffer_ == NULL)
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return;
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}
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// Now that we have successfully read all the data, parse the debug
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// info.
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this->data_valid_ = true;
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this->read_line_mappings(object, read_shndx);
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}
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// Read the DWARF header.
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template<int size, bool big_endian>
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const unsigned char*
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Sized_dwarf_line_info<size, big_endian>::read_header_prolog(
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const unsigned char* lineptr)
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{
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uint32_t initial_length = elfcpp::Swap_unaligned<32, big_endian>::readval(lineptr);
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lineptr += 4;
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// In DWARF2/3, if the initial length is all 1 bits, then the offset
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// size is 8 and we need to read the next 8 bytes for the real length.
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if (initial_length == 0xffffffff)
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{
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header_.offset_size = 8;
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initial_length = elfcpp::Swap_unaligned<64, big_endian>::readval(lineptr);
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lineptr += 8;
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}
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else
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header_.offset_size = 4;
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header_.total_length = initial_length;
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gold_assert(lineptr + header_.total_length <= buffer_end_);
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header_.version = elfcpp::Swap_unaligned<16, big_endian>::readval(lineptr);
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lineptr += 2;
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if (header_.offset_size == 4)
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header_.prologue_length = elfcpp::Swap_unaligned<32, big_endian>::readval(lineptr);
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else
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header_.prologue_length = elfcpp::Swap_unaligned<64, big_endian>::readval(lineptr);
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lineptr += header_.offset_size;
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header_.min_insn_length = *lineptr;
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lineptr += 1;
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header_.default_is_stmt = *lineptr;
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lineptr += 1;
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header_.line_base = *reinterpret_cast<const signed char*>(lineptr);
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lineptr += 1;
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header_.line_range = *lineptr;
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lineptr += 1;
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header_.opcode_base = *lineptr;
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lineptr += 1;
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header_.std_opcode_lengths.reserve(header_.opcode_base + 1);
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header_.std_opcode_lengths[0] = 0;
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for (int i = 1; i < header_.opcode_base; i++)
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{
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header_.std_opcode_lengths[i] = *lineptr;
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lineptr += 1;
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}
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return lineptr;
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}
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// The header for a debug_line section is mildly complicated, because
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// the line info is very tightly encoded.
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template<int size, bool big_endian>
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const unsigned char*
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Sized_dwarf_line_info<size, big_endian>::read_header_tables(
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const unsigned char* lineptr)
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{
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++this->current_header_index_;
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// Create a new directories_ entry and a new files_ entry for our new
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// header. We initialize each with a single empty element, because
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// dwarf indexes directory and filenames starting at 1.
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gold_assert(static_cast<int>(this->directories_.size())
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== this->current_header_index_);
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gold_assert(static_cast<int>(this->files_.size())
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== this->current_header_index_);
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this->directories_.push_back(std::vector<std::string>(1));
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this->files_.push_back(std::vector<std::pair<int, std::string> >(1));
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// It is legal for the directory entry table to be empty.
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if (*lineptr)
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{
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int dirindex = 1;
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while (*lineptr)
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{
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const char* dirname = reinterpret_cast<const char*>(lineptr);
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gold_assert(dirindex
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== static_cast<int>(this->directories_.back().size()));
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this->directories_.back().push_back(dirname);
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lineptr += this->directories_.back().back().size() + 1;
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dirindex++;
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}
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}
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lineptr++;
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// It is also legal for the file entry table to be empty.
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if (*lineptr)
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{
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int fileindex = 1;
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size_t len;
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while (*lineptr)
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{
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const char* filename = reinterpret_cast<const char*>(lineptr);
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lineptr += strlen(filename) + 1;
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uint64_t dirindex = read_unsigned_LEB_128(lineptr, &len);
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lineptr += len;
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if (dirindex >= this->directories_.back().size())
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dirindex = 0;
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int dirindexi = static_cast<int>(dirindex);
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read_unsigned_LEB_128(lineptr, &len); // mod_time
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lineptr += len;
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read_unsigned_LEB_128(lineptr, &len); // filelength
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lineptr += len;
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gold_assert(fileindex
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== static_cast<int>(this->files_.back().size()));
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this->files_.back().push_back(std::make_pair(dirindexi, filename));
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fileindex++;
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}
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}
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lineptr++;
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return lineptr;
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}
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// Process a single opcode in the .debug.line structure.
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// Templating on size and big_endian would yield more efficient (and
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// simpler) code, but would bloat the binary. Speed isn't important
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// here.
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template<int size, bool big_endian>
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bool
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Sized_dwarf_line_info<size, big_endian>::process_one_opcode(
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const unsigned char* start, struct LineStateMachine* lsm, size_t* len)
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{
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size_t oplen = 0;
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size_t templen;
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unsigned char opcode = *start;
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oplen++;
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start++;
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// If the opcode is great than the opcode_base, it is a special
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// opcode. Most line programs consist mainly of special opcodes.
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if (opcode >= header_.opcode_base)
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{
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opcode -= header_.opcode_base;
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const int advance_address = ((opcode / header_.line_range)
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* header_.min_insn_length);
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lsm->address += advance_address;
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const int advance_line = ((opcode % header_.line_range)
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+ header_.line_base);
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lsm->line_num += advance_line;
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lsm->basic_block = true;
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*len = oplen;
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return true;
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}
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// Otherwise, we have the regular opcodes
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switch (opcode)
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{
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case elfcpp::DW_LNS_copy:
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lsm->basic_block = false;
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*len = oplen;
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return true;
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case elfcpp::DW_LNS_advance_pc:
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{
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const uint64_t advance_address
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= read_unsigned_LEB_128(start, &templen);
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oplen += templen;
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lsm->address += header_.min_insn_length * advance_address;
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}
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break;
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case elfcpp::DW_LNS_advance_line:
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{
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const uint64_t advance_line = read_signed_LEB_128(start, &templen);
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oplen += templen;
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lsm->line_num += advance_line;
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}
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break;
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case elfcpp::DW_LNS_set_file:
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{
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const uint64_t fileno = read_unsigned_LEB_128(start, &templen);
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oplen += templen;
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lsm->file_num = fileno;
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}
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break;
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case elfcpp::DW_LNS_set_column:
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{
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const uint64_t colno = read_unsigned_LEB_128(start, &templen);
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oplen += templen;
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lsm->column_num = colno;
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}
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break;
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case elfcpp::DW_LNS_negate_stmt:
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lsm->is_stmt = !lsm->is_stmt;
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break;
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case elfcpp::DW_LNS_set_basic_block:
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lsm->basic_block = true;
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break;
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case elfcpp::DW_LNS_fixed_advance_pc:
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{
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int advance_address;
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advance_address = elfcpp::Swap_unaligned<16, big_endian>::readval(start);
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oplen += 2;
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lsm->address += advance_address;
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}
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break;
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case elfcpp::DW_LNS_const_add_pc:
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{
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const int advance_address = (header_.min_insn_length
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* ((255 - header_.opcode_base)
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/ header_.line_range));
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lsm->address += advance_address;
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}
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break;
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case elfcpp::DW_LNS_extended_op:
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{
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const uint64_t extended_op_len
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= read_unsigned_LEB_128(start, &templen);
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start += templen;
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oplen += templen + extended_op_len;
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const unsigned char extended_op = *start;
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start++;
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switch (extended_op)
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{
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case elfcpp::DW_LNE_end_sequence:
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// This means that the current byte is the one immediately
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// after a set of instructions. Record the current line
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// for up to one less than the current address.
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lsm->line_num = -1;
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lsm->end_sequence = true;
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*len = oplen;
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return true;
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case elfcpp::DW_LNE_set_address:
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{
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lsm->address = elfcpp::Swap_unaligned<size, big_endian>::readval(start);
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typename Reloc_map::const_iterator it
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= reloc_map_.find(start - this->buffer_);
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if (it != reloc_map_.end())
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{
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// value + addend.
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lsm->address += it->second.second;
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lsm->shndx = it->second.first;
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}
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else
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{
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// If we're a normal .o file, with relocs, every
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// set_address should have an associated relocation.
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if (this->input_is_relobj())
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this->data_valid_ = false;
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}
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break;
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}
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case elfcpp::DW_LNE_define_file:
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{
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const char* filename = reinterpret_cast<const char*>(start);
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templen = strlen(filename) + 1;
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start += templen;
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uint64_t dirindex = read_unsigned_LEB_128(start, &templen);
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oplen += templen;
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if (dirindex >= this->directories_.back().size())
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dirindex = 0;
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int dirindexi = static_cast<int>(dirindex);
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read_unsigned_LEB_128(start, &templen); // mod_time
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oplen += templen;
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read_unsigned_LEB_128(start, &templen); // filelength
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oplen += templen;
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this->files_.back().push_back(std::make_pair(dirindexi,
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filename));
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}
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break;
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}
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}
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break;
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default:
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{
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// Ignore unknown opcode silently.
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for (int i = 0; i < header_.std_opcode_lengths[opcode]; i++)
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{
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read_unsigned_LEB_128(start, &templen);
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start += templen;
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oplen += templen;
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}
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}
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break;
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}
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*len = oplen;
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return false;
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}
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// Read the debug information at LINEPTR and store it in the line
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// number map.
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template<int size, bool big_endian>
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unsigned const char*
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Sized_dwarf_line_info<size, big_endian>::read_lines(unsigned const char* lineptr,
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unsigned int shndx)
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{
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struct LineStateMachine lsm;
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// LENGTHSTART is the place the length field is based on. It is the
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// point in the header after the initial length field.
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const unsigned char* lengthstart = buffer_;
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// In 64 bit dwarf, the initial length is 12 bytes, because of the
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// 0xffffffff at the start.
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if (header_.offset_size == 8)
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lengthstart += 12;
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else
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lengthstart += 4;
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while (lineptr < lengthstart + header_.total_length)
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{
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ResetLineStateMachine(&lsm, header_.default_is_stmt);
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while (!lsm.end_sequence)
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{
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size_t oplength;
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bool add_line = this->process_one_opcode(lineptr, &lsm, &oplength);
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if (add_line
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&& (shndx == -1U || lsm.shndx == -1U || shndx == lsm.shndx))
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{
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Offset_to_lineno_entry entry
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= { lsm.address, this->current_header_index_,
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lsm.file_num, lsm.line_num };
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line_number_map_[lsm.shndx].push_back(entry);
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}
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lineptr += oplength;
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}
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}
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return lengthstart + header_.total_length;
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}
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// Looks in the symtab to see what section a symbol is in.
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template<int size, bool big_endian>
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unsigned int
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Sized_dwarf_line_info<size, big_endian>::symbol_section(
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Object* object,
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unsigned int sym,
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typename elfcpp::Elf_types<size>::Elf_Addr* value,
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bool* is_ordinary)
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{
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const int symsize = elfcpp::Elf_sizes<size>::sym_size;
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gold_assert(sym * symsize < this->symtab_buffer_size_);
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elfcpp::Sym<size, big_endian> elfsym(this->symtab_buffer_ + sym * symsize);
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*value = elfsym.get_st_value();
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return object->adjust_sym_shndx(sym, elfsym.get_st_shndx(), is_ordinary);
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}
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// Read the relocations into a Reloc_map.
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template<int size, bool big_endian>
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void
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Sized_dwarf_line_info<size, big_endian>::read_relocs(Object* object)
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{
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if (this->symtab_buffer_ == NULL)
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return;
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typename elfcpp::Elf_types<size>::Elf_Addr value;
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off_t reloc_offset;
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while ((reloc_offset = this->track_relocs_.next_offset()) != -1)
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{
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const unsigned int sym = this->track_relocs_.next_symndx();
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bool is_ordinary;
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const unsigned int shndx = this->symbol_section(object, sym, &value,
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&is_ordinary);
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|
|
// There is no reason to record non-ordinary section indexes, or
|
|
// SHN_UNDEF, because they will never match the real section.
|
|
if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
|
|
this->reloc_map_[reloc_offset] = std::make_pair(shndx, value);
|
|
|
|
this->track_relocs_.advance(reloc_offset + 1);
|
|
}
|
|
}
|
|
|
|
// Read the line number info.
|
|
|
|
template<int size, bool big_endian>
|
|
void
|
|
Sized_dwarf_line_info<size, big_endian>::read_line_mappings(Object* object,
|
|
unsigned int shndx)
|
|
{
|
|
gold_assert(this->data_valid_ == true);
|
|
|
|
this->read_relocs(object);
|
|
while (this->buffer_ < this->buffer_end_)
|
|
{
|
|
const unsigned char* lineptr = this->buffer_;
|
|
lineptr = this->read_header_prolog(lineptr);
|
|
lineptr = this->read_header_tables(lineptr);
|
|
lineptr = this->read_lines(lineptr, shndx);
|
|
this->buffer_ = lineptr;
|
|
}
|
|
|
|
// Sort the lines numbers, so addr2line can use binary search.
|
|
for (typename Lineno_map::iterator it = line_number_map_.begin();
|
|
it != line_number_map_.end();
|
|
++it)
|
|
// Each vector needs to be sorted by offset.
|
|
std::sort(it->second.begin(), it->second.end());
|
|
}
|
|
|
|
// Some processing depends on whether the input is a .o file or not.
|
|
// For instance, .o files have relocs, and have .debug_lines
|
|
// information on a per section basis. .so files, on the other hand,
|
|
// lack relocs, and offsets are unique, so we can ignore the section
|
|
// information.
|
|
|
|
template<int size, bool big_endian>
|
|
bool
|
|
Sized_dwarf_line_info<size, big_endian>::input_is_relobj()
|
|
{
|
|
// Only .o files have relocs and the symtab buffer that goes with them.
|
|
return this->symtab_buffer_ != NULL;
|
|
}
|
|
|
|
// Given an Offset_to_lineno_entry vector, and an offset, figure out
|
|
// if the offset points into a function according to the vector (see
|
|
// comments below for the algorithm). If it does, return an iterator
|
|
// into the vector that points to the line-number that contains that
|
|
// offset. If not, it returns vector::end().
|
|
|
|
static std::vector<Offset_to_lineno_entry>::const_iterator
|
|
offset_to_iterator(const std::vector<Offset_to_lineno_entry>* offsets,
|
|
off_t offset)
|
|
{
|
|
const Offset_to_lineno_entry lookup_key = { offset, 0, 0, 0 };
|
|
|
|
// lower_bound() returns the smallest offset which is >= lookup_key.
|
|
// If no offset in offsets is >= lookup_key, returns end().
|
|
std::vector<Offset_to_lineno_entry>::const_iterator it
|
|
= std::lower_bound(offsets->begin(), offsets->end(), lookup_key);
|
|
|
|
// This code is easiest to understand with a concrete example.
|
|
// Here's a possible offsets array:
|
|
// {{offset = 3211, header_num = 0, file_num = 1, line_num = 16}, // 0
|
|
// {offset = 3224, header_num = 0, file_num = 1, line_num = 20}, // 1
|
|
// {offset = 3226, header_num = 0, file_num = 1, line_num = 22}, // 2
|
|
// {offset = 3231, header_num = 0, file_num = 1, line_num = 25}, // 3
|
|
// {offset = 3232, header_num = 0, file_num = 1, line_num = -1}, // 4
|
|
// {offset = 3232, header_num = 0, file_num = 1, line_num = 65}, // 5
|
|
// {offset = 3235, header_num = 0, file_num = 1, line_num = 66}, // 6
|
|
// {offset = 3236, header_num = 0, file_num = 1, line_num = -1}, // 7
|
|
// {offset = 5764, header_num = 0, file_num = 1, line_num = 47}, // 8
|
|
// {offset = 5765, header_num = 0, file_num = 1, line_num = 48}, // 9
|
|
// {offset = 5767, header_num = 0, file_num = 1, line_num = 49}, // 10
|
|
// {offset = 5768, header_num = 0, file_num = 1, line_num = 50}, // 11
|
|
// {offset = 5773, header_num = 0, file_num = 1, line_num = -1}, // 12
|
|
// {offset = 5787, header_num = 1, file_num = 1, line_num = 19}, // 13
|
|
// {offset = 5790, header_num = 1, file_num = 1, line_num = 20}, // 14
|
|
// {offset = 5793, header_num = 1, file_num = 1, line_num = 67}, // 15
|
|
// {offset = 5793, header_num = 1, file_num = 1, line_num = -1}, // 16
|
|
// {offset = 5795, header_num = 1, file_num = 1, line_num = 68}, // 17
|
|
// {offset = 5798, header_num = 1, file_num = 1, line_num = -1}, // 18
|
|
// The entries with line_num == -1 mark the end of a function: the
|
|
// associated offset is one past the last instruction in the
|
|
// function. This can correspond to the beginning of the next
|
|
// function (as is true for offset 3232); alternately, there can be
|
|
// a gap between the end of one function and the start of the next
|
|
// (as is true for some others, most obviously from 3236->5764).
|
|
//
|
|
// Case 1: lookup_key has offset == 10. lower_bound returns
|
|
// offsets[0]. Since it's not an exact match and we're
|
|
// at the beginning of offsets, we return end() (invalid).
|
|
// Case 2: lookup_key has offset 10000. lower_bound returns
|
|
// offset[19] (end()). We return end() (invalid).
|
|
// Case 3: lookup_key has offset == 3211. lower_bound matches
|
|
// offsets[0] exactly, and that's the entry we return.
|
|
// Case 4: lookup_key has offset == 3232. lower_bound returns
|
|
// offsets[4]. That's an exact match, but indicates
|
|
// end-of-function. We check if offsets[5] is also an
|
|
// exact match but not end-of-function. It is, so we
|
|
// return offsets[5].
|
|
// Case 5: lookup_key has offset == 3214. lower_bound returns
|
|
// offsets[1]. Since it's not an exact match, we back
|
|
// up to the offset that's < lookup_key, offsets[0].
|
|
// We note offsets[0] is a valid entry (not end-of-function),
|
|
// so that's the entry we return.
|
|
// Case 6: lookup_key has offset == 4000. lower_bound returns
|
|
// offsets[8]. Since it's not an exact match, we back
|
|
// up to offsets[7]. Since offsets[7] indicates
|
|
// end-of-function, we know lookup_key is between
|
|
// functions, so we return end() (not a valid offset).
|
|
// Case 7: lookup_key has offset == 5794. lower_bound returns
|
|
// offsets[17]. Since it's not an exact match, we back
|
|
// up to offsets[15]. Note we back up to the *first*
|
|
// entry with offset 5793, not just offsets[17-1].
|
|
// We note offsets[15] is a valid entry, so we return it.
|
|
// If offsets[15] had had line_num == -1, we would have
|
|
// checked offsets[16]. The reason for this is that
|
|
// 15 and 16 can be in an arbitrary order, since we sort
|
|
// only by offset. (Note it doesn't help to use line_number
|
|
// as a secondary sort key, since sometimes we want the -1
|
|
// to be first and sometimes we want it to be last.)
|
|
|
|
// This deals with cases (1) and (2).
|
|
if ((it == offsets->begin() && offset < it->offset)
|
|
|| it == offsets->end())
|
|
return offsets->end();
|
|
|
|
// This deals with cases (3) and (4).
|
|
if (offset == it->offset)
|
|
{
|
|
while (it != offsets->end()
|
|
&& it->offset == offset
|
|
&& it->line_num == -1)
|
|
++it;
|
|
if (it == offsets->end() || it->offset != offset)
|
|
return offsets->end();
|
|
else
|
|
return it;
|
|
}
|
|
|
|
// This handles the first part of case (7) -- we back up to the
|
|
// *first* entry that has the offset that's behind us.
|
|
gold_assert(it != offsets->begin());
|
|
std::vector<Offset_to_lineno_entry>::const_iterator range_end = it;
|
|
--it;
|
|
const off_t range_value = it->offset;
|
|
while (it != offsets->begin() && (it-1)->offset == range_value)
|
|
--it;
|
|
|
|
// This handles cases (5), (6), and (7): if any entry in the
|
|
// equal_range [it, range_end) has a line_num != -1, it's a valid
|
|
// match. If not, we're not in a function.
|
|
for (; it != range_end; ++it)
|
|
if (it->line_num != -1)
|
|
return it;
|
|
return offsets->end();
|
|
}
|
|
|
|
// Return a string for a file name and line number.
|
|
|
|
template<int size, bool big_endian>
|
|
std::string
|
|
Sized_dwarf_line_info<size, big_endian>::do_addr2line(unsigned int shndx,
|
|
off_t offset)
|
|
{
|
|
if (this->data_valid_ == false)
|
|
return "";
|
|
|
|
const std::vector<Offset_to_lineno_entry>* offsets;
|
|
// If we do not have reloc information, then our input is a .so or
|
|
// some similar data structure where all the information is held in
|
|
// the offset. In that case, we ignore the input shndx.
|
|
if (this->input_is_relobj())
|
|
offsets = &this->line_number_map_[shndx];
|
|
else
|
|
offsets = &this->line_number_map_[-1U];
|
|
if (offsets->empty())
|
|
return "";
|
|
|
|
typename std::vector<Offset_to_lineno_entry>::const_iterator it
|
|
= offset_to_iterator(offsets, offset);
|
|
if (it == offsets->end())
|
|
return "";
|
|
|
|
// Convert the file_num + line_num into a string.
|
|
std::string ret;
|
|
|
|
gold_assert(it->header_num < static_cast<int>(this->files_.size()));
|
|
gold_assert(it->file_num
|
|
< static_cast<int>(this->files_[it->header_num].size()));
|
|
const std::pair<int, std::string>& filename_pair
|
|
= this->files_[it->header_num][it->file_num];
|
|
const std::string& filename = filename_pair.second;
|
|
|
|
gold_assert(it->header_num < static_cast<int>(this->directories_.size()));
|
|
gold_assert(filename_pair.first
|
|
< static_cast<int>(this->directories_[it->header_num].size()));
|
|
const std::string& dirname
|
|
= this->directories_[it->header_num][filename_pair.first];
|
|
|
|
if (!dirname.empty())
|
|
{
|
|
ret += dirname;
|
|
ret += "/";
|
|
}
|
|
ret += filename;
|
|
if (ret.empty())
|
|
ret = "(unknown)";
|
|
|
|
char buffer[64]; // enough to hold a line number
|
|
snprintf(buffer, sizeof(buffer), "%d", it->line_num);
|
|
ret += ":";
|
|
ret += buffer;
|
|
|
|
return ret;
|
|
}
|
|
|
|
// Dwarf_line_info routines.
|
|
|
|
static unsigned int next_generation_count = 0;
|
|
|
|
struct Addr2line_cache_entry
|
|
{
|
|
Object* object;
|
|
unsigned int shndx;
|
|
Dwarf_line_info* dwarf_line_info;
|
|
unsigned int generation_count;
|
|
unsigned int access_count;
|
|
|
|
Addr2line_cache_entry(Object* o, unsigned int s, Dwarf_line_info* d)
|
|
: object(o), shndx(s), dwarf_line_info(d),
|
|
generation_count(next_generation_count), access_count(0)
|
|
{
|
|
if (next_generation_count < (1U << 31))
|
|
++next_generation_count;
|
|
}
|
|
};
|
|
// We expect this cache to be small, so don't bother with a hashtable
|
|
// or priority queue or anything: just use a simple vector.
|
|
static std::vector<Addr2line_cache_entry> addr2line_cache;
|
|
|
|
std::string
|
|
Dwarf_line_info::one_addr2line(Object* object,
|
|
unsigned int shndx, off_t offset,
|
|
size_t cache_size)
|
|
{
|
|
Dwarf_line_info* lineinfo = NULL;
|
|
std::vector<Addr2line_cache_entry>::iterator it;
|
|
|
|
// First, check the cache. If we hit, update the counts.
|
|
for (it = addr2line_cache.begin(); it != addr2line_cache.end(); ++it)
|
|
{
|
|
if (it->object == object && it->shndx == shndx)
|
|
{
|
|
lineinfo = it->dwarf_line_info;
|
|
it->generation_count = next_generation_count;
|
|
// We cap generation_count at 2^31 -1 to avoid overflow.
|
|
if (next_generation_count < (1U << 31))
|
|
++next_generation_count;
|
|
// We cap access_count at 31 so 2^access_count doesn't overflow
|
|
if (it->access_count < 31)
|
|
++it->access_count;
|
|
break;
|
|
}
|
|
}
|
|
|
|
// If we don't hit the cache, create a new object and insert into the
|
|
// cache.
|
|
if (lineinfo == NULL)
|
|
{
|
|
switch (parameters->size_and_endianness())
|
|
{
|
|
#ifdef HAVE_TARGET_32_LITTLE
|
|
case Parameters::TARGET_32_LITTLE:
|
|
lineinfo = new Sized_dwarf_line_info<32, false>(object, shndx); break;
|
|
#endif
|
|
#ifdef HAVE_TARGET_32_BIG
|
|
case Parameters::TARGET_32_BIG:
|
|
lineinfo = new Sized_dwarf_line_info<32, true>(object, shndx); break;
|
|
#endif
|
|
#ifdef HAVE_TARGET_64_LITTLE
|
|
case Parameters::TARGET_64_LITTLE:
|
|
lineinfo = new Sized_dwarf_line_info<64, false>(object, shndx); break;
|
|
#endif
|
|
#ifdef HAVE_TARGET_64_BIG
|
|
case Parameters::TARGET_64_BIG:
|
|
lineinfo = new Sized_dwarf_line_info<64, true>(object, shndx); break;
|
|
#endif
|
|
default:
|
|
gold_unreachable();
|
|
}
|
|
addr2line_cache.push_back(Addr2line_cache_entry(object, shndx, lineinfo));
|
|
}
|
|
|
|
// Now that we have our object, figure out the answer
|
|
std::string retval = lineinfo->addr2line(shndx, offset);
|
|
|
|
// Finally, if our cache has grown too big, delete old objects. We
|
|
// assume the common (probably only) case is deleting only one object.
|
|
// We use a pretty simple scheme to evict: function of LRU and MFU.
|
|
while (addr2line_cache.size() > cache_size)
|
|
{
|
|
unsigned int lowest_score = ~0U;
|
|
std::vector<Addr2line_cache_entry>::iterator lowest
|
|
= addr2line_cache.end();
|
|
for (it = addr2line_cache.begin(); it != addr2line_cache.end(); ++it)
|
|
{
|
|
const unsigned int score = (it->generation_count
|
|
+ (1U << it->access_count));
|
|
if (score < lowest_score)
|
|
{
|
|
lowest_score = score;
|
|
lowest = it;
|
|
}
|
|
}
|
|
if (lowest != addr2line_cache.end())
|
|
{
|
|
delete lowest->dwarf_line_info;
|
|
addr2line_cache.erase(lowest);
|
|
}
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
void
|
|
Dwarf_line_info::clear_addr2line_cache()
|
|
{
|
|
for (std::vector<Addr2line_cache_entry>::iterator it = addr2line_cache.begin();
|
|
it != addr2line_cache.end();
|
|
++it)
|
|
delete it->dwarf_line_info;
|
|
addr2line_cache.clear();
|
|
}
|
|
|
|
#ifdef HAVE_TARGET_32_LITTLE
|
|
template
|
|
class Sized_dwarf_line_info<32, false>;
|
|
#endif
|
|
|
|
#ifdef HAVE_TARGET_32_BIG
|
|
template
|
|
class Sized_dwarf_line_info<32, true>;
|
|
#endif
|
|
|
|
#ifdef HAVE_TARGET_64_LITTLE
|
|
template
|
|
class Sized_dwarf_line_info<64, false>;
|
|
#endif
|
|
|
|
#ifdef HAVE_TARGET_64_BIG
|
|
template
|
|
class Sized_dwarf_line_info<64, true>;
|
|
#endif
|
|
|
|
} // End namespace gold.
|