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Diffstat (limited to 'toolkit/crashreporter/google-breakpad/src/common/dwarf_line_to_module.h')
-rw-r--r-- | toolkit/crashreporter/google-breakpad/src/common/dwarf_line_to_module.h | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/toolkit/crashreporter/google-breakpad/src/common/dwarf_line_to_module.h b/toolkit/crashreporter/google-breakpad/src/common/dwarf_line_to_module.h new file mode 100644 index 000000000..1fdd4cb71 --- /dev/null +++ b/toolkit/crashreporter/google-breakpad/src/common/dwarf_line_to_module.h @@ -0,0 +1,188 @@ +// -*- mode: c++ -*- + +// Copyright (c) 2010 Google Inc. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +// Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com> + +// The DwarfLineToModule class accepts line number information from a +// DWARF parser and adds it to a google_breakpad::Module. The Module +// can write that data out as a Breakpad symbol file. + +#ifndef COMMON_LINUX_DWARF_LINE_TO_MODULE_H +#define COMMON_LINUX_DWARF_LINE_TO_MODULE_H + +#include <string> + +#include "common/module.h" +#include "common/dwarf/dwarf2reader.h" +#include "common/using_std_string.h" + +namespace google_breakpad { + +// A class for producing a vector of google_breakpad::Module::Line +// instances from parsed DWARF line number data. +// +// An instance of this class can be provided as a handler to a +// dwarf2reader::LineInfo DWARF line number information parser. The +// handler accepts source location information from the parser and +// uses it to produce a vector of google_breakpad::Module::Line +// objects, referring to google_breakpad::Module::File objects added +// to a particular google_breakpad::Module. +// +// GNU toolchain omitted sections support: +// ====================================== +// +// Given the right options, the GNU toolchain will omit unreferenced +// functions from the final executable. Unfortunately, when it does so, it +// does not remove the associated portions of the DWARF line number +// program; instead, it gives the DW_LNE_set_address instructions referring +// to the now-deleted code addresses of zero. Given this input, the DWARF +// line parser will call AddLine with a series of lines starting at address +// zero. For example, here is the output from 'readelf -wl' for a program +// with four functions, the first three of which have been omitted: +// +// Line Number Statements: +// Extended opcode 2: set Address to 0x0 +// Advance Line by 14 to 15 +// Copy +// Special opcode 48: advance Address by 3 to 0x3 and Line by 1 to 16 +// Special opcode 119: advance Address by 8 to 0xb and Line by 2 to 18 +// Advance PC by 2 to 0xd +// Extended opcode 1: End of Sequence +// +// Extended opcode 2: set Address to 0x0 +// Advance Line by 14 to 15 +// Copy +// Special opcode 48: advance Address by 3 to 0x3 and Line by 1 to 16 +// Special opcode 119: advance Address by 8 to 0xb and Line by 2 to 18 +// Advance PC by 2 to 0xd +// Extended opcode 1: End of Sequence +// +// Extended opcode 2: set Address to 0x0 +// Advance Line by 19 to 20 +// Copy +// Special opcode 48: advance Address by 3 to 0x3 and Line by 1 to 21 +// Special opcode 76: advance Address by 5 to 0x8 and Line by 1 to 22 +// Advance PC by 2 to 0xa +// Extended opcode 1: End of Sequence +// +// Extended opcode 2: set Address to 0x80483a4 +// Advance Line by 23 to 24 +// Copy +// Special opcode 202: advance Address by 14 to 0x80483b2 and Line by 1 to 25 +// Special opcode 76: advance Address by 5 to 0x80483b7 and Line by 1 to 26 +// Advance PC by 6 to 0x80483bd +// Extended opcode 1: End of Sequence +// +// Instead of collecting runs of lines describing code that is not there, +// we try to recognize and drop them. Since the linker doesn't explicitly +// distinguish references to dropped sections from genuine references to +// code at address zero, we must use a heuristic. We have chosen: +// +// - If a line starts at address zero, omit it. (On the platforms +// breakpad targets, it is extremely unlikely that there will be code +// at address zero.) +// +// - If a line starts immediately after an omitted line, omit it too. +class DwarfLineToModule: public dwarf2reader::LineInfoHandler { + public: + // As the DWARF line info parser passes us line records, add source + // files to MODULE, and add all lines to the end of LINES. LINES + // need not be empty. If the parser hands us a zero-length line, we + // omit it. If the parser hands us a line that extends beyond the + // end of the address space, we clip it. It's up to our client to + // sort out which lines belong to which functions; we don't add them + // to any particular function in MODULE ourselves. + DwarfLineToModule(Module *module, const string& compilation_dir, + vector<Module::Line> *lines) + : module_(module), + compilation_dir_(compilation_dir), + lines_(lines), + highest_file_number_(-1), + omitted_line_end_(0), + warned_bad_file_number_(false), + warned_bad_directory_number_(false) { } + + ~DwarfLineToModule() { } + + void DefineDir(const string &name, uint32 dir_num); + void DefineFile(const string &name, int32 file_num, + uint32 dir_num, uint64 mod_time, + uint64 length); + void AddLine(uint64 address, uint64 length, + uint32 file_num, uint32 line_num, uint32 column_num); + + private: + + typedef std::map<uint32, string> DirectoryTable; + typedef std::map<uint32, Module::File *> FileTable; + + // The module we're contributing debugging info to. Owned by our + // client. + Module *module_; + + // The compilation directory for the current compilation unit whose + // lines are being accumulated. + string compilation_dir_; + + // The vector of lines we're accumulating. Owned by our client. + // + // In a Module, as in a breakpad symbol file, lines belong to + // specific functions, but DWARF simply assigns lines to addresses; + // one must infer the line/function relationship using the + // functions' beginning and ending addresses. So we can't add these + // to the appropriate function from module_ until we've read the + // function info as well. Instead, we accumulate lines here, and let + // whoever constructed this sort it all out. + vector<Module::Line> *lines_; + + // A table mapping directory numbers to paths. + DirectoryTable directories_; + + // A table mapping file numbers to Module::File pointers. + FileTable files_; + + // The highest file number we've seen so far, or -1 if we've seen + // none. Used for dynamically defined file numbers. + int32 highest_file_number_; + + // This is the ending address of the last line we omitted, or zero if we + // didn't omit the previous line. It is zero before we have received any + // AddLine calls. + uint64 omitted_line_end_; + + // True if we've warned about: + bool warned_bad_file_number_; // bad file numbers + bool warned_bad_directory_number_; // bad directory numbers +}; + +} // namespace google_breakpad + +#endif // COMMON_LINUX_DWARF_LINE_TO_MODULE_H |