The Tor Browser: toolkit/crashreporter/google-breakpad/src/common/stabs

toolkit/crashreporter/google-breakpad/src/common/stabs_reader.cc@6474c204b198 (annotated)

toolkit/crashreporter/google-breakpad/src/common/stabs_reader.cc

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 // 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>
 // This file implements the google_breakpad::StabsReader class.
 // See stabs_reader.h.
 #include "common/stabs_reader.h"
 #include <assert.h>
 #include <stab.h>
 #include <string.h>
 #include <string>
 #include "common/using_std_string.h"
 using std::vector;
 namespace google_breakpad {
 StabsReader::EntryIterator::EntryIterator(const ByteBuffer *buffer,
                                           bool big_endian, size_t value_size)
     : value_size_(value_size), cursor_(buffer, big_endian) {
   // Actually, we could handle weird sizes just fine, but they're
   // probably mistakes --- expressed in bits, say.
   assert(value_size == 4 || value_size == 8);
   entry_.index = 0;
   Fetch();
 }
 void StabsReader::EntryIterator::Fetch() {
   cursor_
       .Read(4, false, &entry_.name_offset)
       .Read(1, false, &entry_.type)
       .Read(1, false, &entry_.other)
       .Read(2, false, &entry_.descriptor)
       .Read(value_size_, false, &entry_.value);
   entry_.at_end = !cursor_;
 }
 StabsReader::StabsReader(const uint8_t *stab,    size_t stab_size,
                          const uint8_t *stabstr, size_t stabstr_size,
                          bool big_endian, size_t value_size, bool unitized,
                          StabsHandler *handler)
     : entries_(stab, stab_size),
       strings_(stabstr, stabstr_size),
       iterator_(&entries_, big_endian, value_size),
       unitized_(unitized),
       handler_(handler),
       string_offset_(0),
       next_cu_string_offset_(0),
       current_source_file_(NULL) { }
 const char *StabsReader::SymbolString() {
   ptrdiff_t offset = string_offset_ + iterator_->name_offset;
   if (offset < 0 || (size_t) offset >= strings_.Size()) {
     handler_->Warning("symbol %d: name offset outside the string section\n",
                       iterator_->index);
     // Return our null string, to keep our promise about all names being
     // taken from the string section.
     offset = 0;
   }
   return reinterpret_cast<const char *>(strings_.start + offset);
 }
 bool StabsReader::Process() {
   while (!iterator_->at_end) {
     if (iterator_->type == N_SO) {
       if (! ProcessCompilationUnit())
         return false;
     } else if (iterator_->type == N_UNDF && unitized_) {
       // In unitized STABS (including Linux STABS, and pretty much anything
       // else that puts STABS data in sections), at the head of each
       // compilation unit's entries there is an N_UNDF stab giving the
       // number of symbols in the compilation unit, and the number of bytes
       // that compilation unit's strings take up in the .stabstr section.
       // Each CU's strings are separate; the n_strx values are offsets
       // within the current CU's portion of the .stabstr section.
       //
       // As an optimization, the GNU linker combines all the
       // compilation units into one, with a single N_UNDF at the
       // beginning. However, other linkers, like Gold, do not perform
       // this optimization.
       string_offset_ = next_cu_string_offset_;
       next_cu_string_offset_ = iterator_->value;
       ++iterator_;
     }
 #if defined(HAVE_MACH_O_NLIST_H)
     // Export symbols in Mach-O binaries look like this.
     // This is necessary in order to be able to dump symbols
     // from OS X system libraries.
     else if ((iterator_->type & N_STAB) == 0 &&
                (iterator_->type & N_TYPE) == N_SECT) {
       ProcessExtern();
     }
 #endif
     else {
       ++iterator_;
     }
   }
   return true;
 }
 bool StabsReader::ProcessCompilationUnit() {
   assert(!iterator_->at_end && iterator_->type == N_SO);
   // There may be an N_SO entry whose name ends with a slash,
   // indicating the directory in which the compilation occurred.
   // The build directory defaults to NULL.
   const char *build_directory = NULL;
   {
     const char *name = SymbolString();
     if (name[0] && name[strlen(name) - 1] == '/') {
       build_directory = name;
       ++iterator_;
     }
   }
   // We expect to see an N_SO entry with a filename next, indicating
   // the start of the compilation unit.
   {
     if (iterator_->at_end || iterator_->type != N_SO)
       return true;
     const char *name = SymbolString();
     if (name[0] == '\0') {
       // This seems to be a stray end-of-compilation-unit marker;
       // consume it, but don't report the end, since we didn't see a
       // beginning.
       ++iterator_;
       return true;
     }
     current_source_file_ = name;
   }
   if (! handler_->StartCompilationUnit(current_source_file_,
                                        iterator_->value,
                                        build_directory))
     return false;
   ++iterator_;
   // The STABS documentation says that some compilers may emit
   // additional N_SO entries with names immediately following the
   // first, and that they should be ignored.  However, the original
   // Breakpad STABS reader doesn't ignore them, so we won't either.
   // Process the body of the compilation unit, up to the next N_SO.
   while (!iterator_->at_end && iterator_->type != N_SO) {
     if (iterator_->type == N_FUN) {
       if (! ProcessFunction())
         return false;
     } else if (iterator_->type == N_SLINE) {
       // Mac OS X STABS place SLINE records before functions.
       Line line;
       // The value of an N_SLINE entry that appears outside a function is
       // the absolute address of the line.
       line.address = iterator_->value;
       line.filename = current_source_file_;
       // The n_desc of a N_SLINE entry is the line number.  It's a
       // signed 16-bit field; line numbers from 32768 to 65535 are
       // stored as n-65536.
       line.number = (uint16_t) iterator_->descriptor;
       queued_lines_.push_back(line);
       ++iterator_;
     } else if (iterator_->type == N_SOL) {
       current_source_file_ = SymbolString();
       ++iterator_;
     } else {
       // Ignore anything else.
       ++iterator_;
     }
   }
   // An N_SO with an empty name indicates the end of the compilation
   // unit.  Default to zero.
   uint64_t ending_address = 0;
   if (!iterator_->at_end) {
     assert(iterator_->type == N_SO);
     const char *name = SymbolString();
     if (name[0] == '\0') {
       ending_address = iterator_->value;
       ++iterator_;
     }
   }
   if (! handler_->EndCompilationUnit(ending_address))
     return false;
   queued_lines_.clear();
   return true;
 }
 bool StabsReader::ProcessFunction() {
   assert(!iterator_->at_end && iterator_->type == N_FUN);
   uint64_t function_address = iterator_->value;
   // The STABS string for an N_FUN entry is the name of the function,
   // followed by a colon, followed by type information for the
   // function.  We want to pass the name alone to StartFunction.
   const char *stab_string = SymbolString();
   const char *name_end = strchr(stab_string, ':');
   if (! name_end)
     name_end = stab_string + strlen(stab_string);
   string name(stab_string, name_end - stab_string);
   if (! handler_->StartFunction(name, function_address))
     return false;
   ++iterator_;
   // If there were any SLINE records given before the function, report them now.
   for (vector<Line>::const_iterator it = queued_lines_.begin();
        it != queued_lines_.end(); it++) {
     if (!handler_->Line(it->address, it->filename, it->number))
       return false;
   }
   queued_lines_.clear();
   while (!iterator_->at_end) {
     if (iterator_->type == N_SO || iterator_->type == N_FUN)
       break;
     else if (iterator_->type == N_SLINE) {
       // The value of an N_SLINE entry is the offset of the line from
       // the function's start address.
       uint64_t line_address = function_address + iterator_->value;
       // The n_desc of a N_SLINE entry is the line number.  It's a
       // signed 16-bit field; line numbers from 32768 to 65535 are
       // stored as n-65536.
       uint16_t line_number = iterator_->descriptor;
       if (! handler_->Line(line_address, current_source_file_, line_number))
         return false;
       ++iterator_;
     } else if (iterator_->type == N_SOL) {
       current_source_file_ = SymbolString();
       ++iterator_;
     } else
       // Ignore anything else.
       ++iterator_;
   }
   // We've reached the end of the function. See if we can figure out its
   // ending address.
   uint64_t ending_address = 0;
   if (!iterator_->at_end) {
     assert(iterator_->type == N_SO || iterator_->type == N_FUN);
     if (iterator_->type == N_FUN) {
       const char *symbol_name = SymbolString();
       if (symbol_name[0] == '\0') {
         // An N_FUN entry with no name is a terminator for this function;
         // its value is the function's size.
         ending_address = function_address + iterator_->value;
         ++iterator_;
       } else {
         // An N_FUN entry with a name is the next function, and we can take
         // its value as our ending address. Don't advance the iterator, as
         // we'll use this symbol to start the next function as well.
         ending_address = iterator_->value;
       }
     } else {
       // An N_SO entry could be an end-of-compilation-unit marker, or the
       // start of the next compilation unit, but in either case, its value
       // is our ending address. We don't advance the iterator;
       // ProcessCompilationUnit will decide what to do with this symbol.
       ending_address = iterator_->value;
     }
   }
   if (! handler_->EndFunction(ending_address))
     return false;
   return true;
 }
 bool StabsReader::ProcessExtern() {
 #if defined(HAVE_MACH_O_NLIST_H)
   assert(!iterator_->at_end &&
          (iterator_->type & N_STAB) == 0 &&
          (iterator_->type & N_TYPE) == N_SECT);
 #endif
   // TODO(mark): only do symbols in the text section?
   if (!handler_->Extern(SymbolString(), iterator_->value))
     return false;
   ++iterator_;
   return true;
 }
 } // namespace google_breakpad

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toolkit/crashreporter/google-breakpad/src/common/stabs_reader.cc@6474c204b198 (annotated)

toolkit/crashreporter/google-breakpad/src/common/stabs_reader.cc