1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/toolkit/crashreporter/google-breakpad/src/common/dwarf_line_to_module.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,188 @@
1.4 +// -*- mode: c++ -*-
1.5 +
1.6 +// Copyright (c) 2010 Google Inc.
1.7 +// All rights reserved.
1.8 +//
1.9 +// Redistribution and use in source and binary forms, with or without
1.10 +// modification, are permitted provided that the following conditions are
1.11 +// met:
1.12 +//
1.13 +// * Redistributions of source code must retain the above copyright
1.14 +// notice, this list of conditions and the following disclaimer.
1.15 +// * Redistributions in binary form must reproduce the above
1.16 +// copyright notice, this list of conditions and the following disclaimer
1.17 +// in the documentation and/or other materials provided with the
1.18 +// distribution.
1.19 +// * Neither the name of Google Inc. nor the names of its
1.20 +// contributors may be used to endorse or promote products derived from
1.21 +// this software without specific prior written permission.
1.22 +//
1.23 +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1.24 +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1.25 +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1.26 +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
1.27 +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
1.28 +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
1.29 +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1.30 +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1.31 +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1.32 +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
1.33 +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.34 +
1.35 +// Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>
1.36 +
1.37 +// The DwarfLineToModule class accepts line number information from a
1.38 +// DWARF parser and adds it to a google_breakpad::Module. The Module
1.39 +// can write that data out as a Breakpad symbol file.
1.40 +
1.41 +#ifndef COMMON_LINUX_DWARF_LINE_TO_MODULE_H
1.42 +#define COMMON_LINUX_DWARF_LINE_TO_MODULE_H
1.43 +
1.44 +#include <string>
1.45 +
1.46 +#include "common/module.h"
1.47 +#include "common/dwarf/dwarf2reader.h"
1.48 +#include "common/using_std_string.h"
1.49 +
1.50 +namespace google_breakpad {
1.51 +
1.52 +// A class for producing a vector of google_breakpad::Module::Line
1.53 +// instances from parsed DWARF line number data.
1.54 +//
1.55 +// An instance of this class can be provided as a handler to a
1.56 +// dwarf2reader::LineInfo DWARF line number information parser. The
1.57 +// handler accepts source location information from the parser and
1.58 +// uses it to produce a vector of google_breakpad::Module::Line
1.59 +// objects, referring to google_breakpad::Module::File objects added
1.60 +// to a particular google_breakpad::Module.
1.61 +//
1.62 +// GNU toolchain omitted sections support:
1.63 +// ======================================
1.64 +//
1.65 +// Given the right options, the GNU toolchain will omit unreferenced
1.66 +// functions from the final executable. Unfortunately, when it does so, it
1.67 +// does not remove the associated portions of the DWARF line number
1.68 +// program; instead, it gives the DW_LNE_set_address instructions referring
1.69 +// to the now-deleted code addresses of zero. Given this input, the DWARF
1.70 +// line parser will call AddLine with a series of lines starting at address
1.71 +// zero. For example, here is the output from 'readelf -wl' for a program
1.72 +// with four functions, the first three of which have been omitted:
1.73 +//
1.74 +// Line Number Statements:
1.75 +// Extended opcode 2: set Address to 0x0
1.76 +// Advance Line by 14 to 15
1.77 +// Copy
1.78 +// Special opcode 48: advance Address by 3 to 0x3 and Line by 1 to 16
1.79 +// Special opcode 119: advance Address by 8 to 0xb and Line by 2 to 18
1.80 +// Advance PC by 2 to 0xd
1.81 +// Extended opcode 1: End of Sequence
1.82 +//
1.83 +// Extended opcode 2: set Address to 0x0
1.84 +// Advance Line by 14 to 15
1.85 +// Copy
1.86 +// Special opcode 48: advance Address by 3 to 0x3 and Line by 1 to 16
1.87 +// Special opcode 119: advance Address by 8 to 0xb and Line by 2 to 18
1.88 +// Advance PC by 2 to 0xd
1.89 +// Extended opcode 1: End of Sequence
1.90 +//
1.91 +// Extended opcode 2: set Address to 0x0
1.92 +// Advance Line by 19 to 20
1.93 +// Copy
1.94 +// Special opcode 48: advance Address by 3 to 0x3 and Line by 1 to 21
1.95 +// Special opcode 76: advance Address by 5 to 0x8 and Line by 1 to 22
1.96 +// Advance PC by 2 to 0xa
1.97 +// Extended opcode 1: End of Sequence
1.98 +//
1.99 +// Extended opcode 2: set Address to 0x80483a4
1.100 +// Advance Line by 23 to 24
1.101 +// Copy
1.102 +// Special opcode 202: advance Address by 14 to 0x80483b2 and Line by 1 to 25
1.103 +// Special opcode 76: advance Address by 5 to 0x80483b7 and Line by 1 to 26
1.104 +// Advance PC by 6 to 0x80483bd
1.105 +// Extended opcode 1: End of Sequence
1.106 +//
1.107 +// Instead of collecting runs of lines describing code that is not there,
1.108 +// we try to recognize and drop them. Since the linker doesn't explicitly
1.109 +// distinguish references to dropped sections from genuine references to
1.110 +// code at address zero, we must use a heuristic. We have chosen:
1.111 +//
1.112 +// - If a line starts at address zero, omit it. (On the platforms
1.113 +// breakpad targets, it is extremely unlikely that there will be code
1.114 +// at address zero.)
1.115 +//
1.116 +// - If a line starts immediately after an omitted line, omit it too.
1.117 +class DwarfLineToModule: public dwarf2reader::LineInfoHandler {
1.118 + public:
1.119 + // As the DWARF line info parser passes us line records, add source
1.120 + // files to MODULE, and add all lines to the end of LINES. LINES
1.121 + // need not be empty. If the parser hands us a zero-length line, we
1.122 + // omit it. If the parser hands us a line that extends beyond the
1.123 + // end of the address space, we clip it. It's up to our client to
1.124 + // sort out which lines belong to which functions; we don't add them
1.125 + // to any particular function in MODULE ourselves.
1.126 + DwarfLineToModule(Module *module, const string& compilation_dir,
1.127 + vector<Module::Line> *lines)
1.128 + : module_(module),
1.129 + compilation_dir_(compilation_dir),
1.130 + lines_(lines),
1.131 + highest_file_number_(-1),
1.132 + omitted_line_end_(0),
1.133 + warned_bad_file_number_(false),
1.134 + warned_bad_directory_number_(false) { }
1.135 +
1.136 + ~DwarfLineToModule() { }
1.137 +
1.138 + void DefineDir(const string &name, uint32 dir_num);
1.139 + void DefineFile(const string &name, int32 file_num,
1.140 + uint32 dir_num, uint64 mod_time,
1.141 + uint64 length);
1.142 + void AddLine(uint64 address, uint64 length,
1.143 + uint32 file_num, uint32 line_num, uint32 column_num);
1.144 +
1.145 + private:
1.146 +
1.147 + typedef std::map<uint32, string> DirectoryTable;
1.148 + typedef std::map<uint32, Module::File *> FileTable;
1.149 +
1.150 + // The module we're contributing debugging info to. Owned by our
1.151 + // client.
1.152 + Module *module_;
1.153 +
1.154 + // The compilation directory for the current compilation unit whose
1.155 + // lines are being accumulated.
1.156 + string compilation_dir_;
1.157 +
1.158 + // The vector of lines we're accumulating. Owned by our client.
1.159 + //
1.160 + // In a Module, as in a breakpad symbol file, lines belong to
1.161 + // specific functions, but DWARF simply assigns lines to addresses;
1.162 + // one must infer the line/function relationship using the
1.163 + // functions' beginning and ending addresses. So we can't add these
1.164 + // to the appropriate function from module_ until we've read the
1.165 + // function info as well. Instead, we accumulate lines here, and let
1.166 + // whoever constructed this sort it all out.
1.167 + vector<Module::Line> *lines_;
1.168 +
1.169 + // A table mapping directory numbers to paths.
1.170 + DirectoryTable directories_;
1.171 +
1.172 + // A table mapping file numbers to Module::File pointers.
1.173 + FileTable files_;
1.174 +
1.175 + // The highest file number we've seen so far, or -1 if we've seen
1.176 + // none. Used for dynamically defined file numbers.
1.177 + int32 highest_file_number_;
1.178 +
1.179 + // This is the ending address of the last line we omitted, or zero if we
1.180 + // didn't omit the previous line. It is zero before we have received any
1.181 + // AddLine calls.
1.182 + uint64 omitted_line_end_;
1.183 +
1.184 + // True if we've warned about:
1.185 + bool warned_bad_file_number_; // bad file numbers
1.186 + bool warned_bad_directory_number_; // bad directory numbers
1.187 +};
1.188 +
1.189 +} // namespace google_breakpad
1.190 +
1.191 +#endif // COMMON_LINUX_DWARF_LINE_TO_MODULE_H
