912 lines
		
	
	
		
			32 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			912 lines
		
	
	
		
			32 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| // Copyright (c) 2011 Google Inc.
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| // All rights reserved.
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| //
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| // Redistribution and use in source and binary forms, with or without
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| // modification, are permitted provided that the following conditions are
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| // met:
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| //
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| //     * Redistributions of source code must retain the above copyright
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| // notice, this list of conditions and the following disclaimer.
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| //     * Redistributions in binary form must reproduce the above
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| // copyright notice, this list of conditions and the following disclaimer
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| // in the documentation and/or other materials provided with the
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| // distribution.
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| //     * Neither the name of Google Inc. nor the names of its
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| // contributors may be used to endorse or promote products derived from
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| // this software without specific prior written permission.
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| //
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| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| 
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| // Restructured in 2009 by: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>
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| 
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| // dump_symbols.cc: implement google_breakpad::WriteSymbolFile:
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| // Find all the debugging info in a file and dump it as a Breakpad symbol file.
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| 
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| #include "common/linux/dump_symbols.h"
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| 
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| #include <assert.h>
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| #include <elf.h>
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| #include <errno.h>
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| #include <fcntl.h>
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| #include <link.h>
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| #include <stdio.h>
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| #include <stdlib.h>
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| #include <string.h>
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| #include <sys/mman.h>
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| #include <sys/stat.h>
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| #include <unistd.h>
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| 
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| #include <iostream>
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| #include <set>
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| #include <string>
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| #include <utility>
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| #include <vector>
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| 
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| #include "common/dwarf/bytereader-inl.h"
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| #include "common/dwarf/dwarf2diehandler.h"
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| #include "common/dwarf_cfi_to_module.h"
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| #include "common/dwarf_cu_to_module.h"
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| #include "common/dwarf_line_to_module.h"
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| #include "common/linux/elfutils.h"
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| #include "common/linux/elfutils-inl.h"
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| #include "common/linux/elf_symbols_to_module.h"
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| #include "common/linux/file_id.h"
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| #include "common/module.h"
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| #include "common/scoped_ptr.h"
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| #ifndef NO_STABS_SUPPORT
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| #include "common/stabs_reader.h"
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| #include "common/stabs_to_module.h"
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| #endif
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| #include "common/using_std_string.h"
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| 
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| // This namespace contains helper functions.
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| namespace {
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| 
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| using google_breakpad::DumpOptions;
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| using google_breakpad::DwarfCFIToModule;
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| using google_breakpad::DwarfCUToModule;
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| using google_breakpad::DwarfLineToModule;
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| using google_breakpad::ElfClass;
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| using google_breakpad::ElfClass32;
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| using google_breakpad::ElfClass64;
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| using google_breakpad::FindElfSectionByName;
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| using google_breakpad::GetOffset;
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| using google_breakpad::IsValidElf;
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| using google_breakpad::Module;
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| #ifndef NO_STABS_SUPPORT
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| using google_breakpad::StabsToModule;
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| #endif
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| using google_breakpad::scoped_ptr;
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| 
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| //
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| // FDWrapper
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| //
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| // Wrapper class to make sure opened file is closed.
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| //
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| class FDWrapper {
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|  public:
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|   explicit FDWrapper(int fd) :
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|     fd_(fd) {}
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|   ~FDWrapper() {
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|     if (fd_ != -1)
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|       close(fd_);
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|   }
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|   int get() {
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|     return fd_;
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|   }
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|   int release() {
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|     int fd = fd_;
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|     fd_ = -1;
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|     return fd;
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|   }
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|  private:
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|   int fd_;
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| };
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| 
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| //
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| // MmapWrapper
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| //
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| // Wrapper class to make sure mapped regions are unmapped.
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| //
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| class MmapWrapper {
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|  public:
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|   MmapWrapper() : is_set_(false) {}
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|   ~MmapWrapper() {
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|     if (is_set_ && base_ != NULL) {
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|       assert(size_ > 0);
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|       munmap(base_, size_);
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|     }
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|   }
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|   void set(void *mapped_address, size_t mapped_size) {
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|     is_set_ = true;
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|     base_ = mapped_address;
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|     size_ = mapped_size;
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|   }
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|   void release() {
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|     assert(is_set_);
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|     is_set_ = false;
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|     base_ = NULL;
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|     size_ = 0;
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|   }
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| 
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|  private:
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|   bool is_set_;
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|   void *base_;
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|   size_t size_;
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| };
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| 
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| // Find the preferred loading address of the binary.
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| template<typename ElfClass>
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| typename ElfClass::Addr GetLoadingAddress(
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|     const typename ElfClass::Phdr* program_headers,
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|     int nheader) {
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|   typedef typename ElfClass::Phdr Phdr;
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| 
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|   // For non-PIC executables (e_type == ET_EXEC), the load address is
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|   // the start address of the first PT_LOAD segment.  (ELF requires
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|   // the segments to be sorted by load address.)  For PIC executables
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|   // and dynamic libraries (e_type == ET_DYN), this address will
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|   // normally be zero.
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|   for (int i = 0; i < nheader; ++i) {
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|     const Phdr& header = program_headers[i];
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|     if (header.p_type == PT_LOAD)
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|       return header.p_vaddr;
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|   }
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|   return 0;
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| }
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| 
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| #ifndef NO_STABS_SUPPORT
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| template<typename ElfClass>
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| bool LoadStabs(const typename ElfClass::Ehdr* elf_header,
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|                const typename ElfClass::Shdr* stab_section,
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|                const typename ElfClass::Shdr* stabstr_section,
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|                const bool big_endian,
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|                Module* module) {
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|   // A callback object to handle data from the STABS reader.
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|   StabsToModule handler(module);
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|   // Find the addresses of the STABS data, and create a STABS reader object.
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|   // On Linux, STABS entries always have 32-bit values, regardless of the
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|   // address size of the architecture whose code they're describing, and
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|   // the strings are always "unitized".
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|   const uint8_t* stabs =
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|       GetOffset<ElfClass, uint8_t>(elf_header, stab_section->sh_offset);
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|   const uint8_t* stabstr =
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|       GetOffset<ElfClass, uint8_t>(elf_header, stabstr_section->sh_offset);
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|   google_breakpad::StabsReader reader(stabs, stab_section->sh_size,
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|                                       stabstr, stabstr_section->sh_size,
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|                                       big_endian, 4, true, &handler);
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|   // Read the STABS data, and do post-processing.
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|   if (!reader.Process())
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|     return false;
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|   handler.Finalize();
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|   return true;
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| }
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| #endif  // NO_STABS_SUPPORT
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| 
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| // A line-to-module loader that accepts line number info parsed by
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| // dwarf2reader::LineInfo and populates a Module and a line vector
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| // with the results.
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| class DumperLineToModule: public DwarfCUToModule::LineToModuleHandler {
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|  public:
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|   // Create a line-to-module converter using BYTE_READER.
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|   explicit DumperLineToModule(dwarf2reader::ByteReader *byte_reader)
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|       : byte_reader_(byte_reader) { }
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|   void StartCompilationUnit(const string& compilation_dir) {
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|     compilation_dir_ = compilation_dir;
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|   }
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|   void ReadProgram(const char *program, uint64 length,
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|                    Module *module, std::vector<Module::Line> *lines) {
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|     DwarfLineToModule handler(module, compilation_dir_, lines);
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|     dwarf2reader::LineInfo parser(program, length, byte_reader_, &handler);
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|     parser.Start();
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|   }
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|  private:
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|   string compilation_dir_;
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|   dwarf2reader::ByteReader *byte_reader_;
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| };
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| 
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| template<typename ElfClass>
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| bool LoadDwarf(const string& dwarf_filename,
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|                const typename ElfClass::Ehdr* elf_header,
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|                const bool big_endian,
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|                bool handle_inter_cu_refs,
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|                Module* module) {
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|   typedef typename ElfClass::Shdr Shdr;
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| 
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|   const dwarf2reader::Endianness endianness = big_endian ?
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|       dwarf2reader::ENDIANNESS_BIG : dwarf2reader::ENDIANNESS_LITTLE;
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|   dwarf2reader::ByteReader byte_reader(endianness);
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| 
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|   // Construct a context for this file.
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|   DwarfCUToModule::FileContext file_context(dwarf_filename,
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|                                             module,
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|                                             handle_inter_cu_refs);
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| 
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|   // Build a map of the ELF file's sections.
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|   const Shdr* sections =
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|       GetOffset<ElfClass, Shdr>(elf_header, elf_header->e_shoff);
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|   int num_sections = elf_header->e_shnum;
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|   const Shdr* section_names = sections + elf_header->e_shstrndx;
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|   for (int i = 0; i < num_sections; i++) {
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|     const Shdr* section = §ions[i];
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|     string name = GetOffset<ElfClass, char>(elf_header,
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|                                             section_names->sh_offset) +
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|                   section->sh_name;
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|     const char* contents = GetOffset<ElfClass, char>(elf_header,
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|                                                      section->sh_offset);
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|     file_context.AddSectionToSectionMap(name, contents, section->sh_size);
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|   }
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| 
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|   // Parse all the compilation units in the .debug_info section.
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|   DumperLineToModule line_to_module(&byte_reader);
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|   dwarf2reader::SectionMap::const_iterator debug_info_entry =
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|       file_context.section_map().find(".debug_info");
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|   assert(debug_info_entry != file_context.section_map().end());
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|   const std::pair<const char*, uint64>& debug_info_section =
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|       debug_info_entry->second;
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|   // This should never have been called if the file doesn't have a
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|   // .debug_info section.
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|   assert(debug_info_section.first);
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|   uint64 debug_info_length = debug_info_section.second;
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|   for (uint64 offset = 0; offset < debug_info_length;) {
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|     // Make a handler for the root DIE that populates MODULE with the
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|     // data that was found.
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|     DwarfCUToModule::WarningReporter reporter(dwarf_filename, offset);
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|     DwarfCUToModule root_handler(&file_context, &line_to_module, &reporter);
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|     // Make a Dwarf2Handler that drives the DIEHandler.
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|     dwarf2reader::DIEDispatcher die_dispatcher(&root_handler);
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|     // Make a DWARF parser for the compilation unit at OFFSET.
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|     dwarf2reader::CompilationUnit reader(file_context.section_map(),
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|                                          offset,
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|                                          &byte_reader,
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|                                          &die_dispatcher);
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|     // Process the entire compilation unit; get the offset of the next.
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|     offset += reader.Start();
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|   }
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|   return true;
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| }
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| 
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| // Fill REGISTER_NAMES with the register names appropriate to the
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| // machine architecture given in HEADER, indexed by the register
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| // numbers used in DWARF call frame information. Return true on
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| // success, or false if HEADER's machine architecture is not
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| // supported.
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| template<typename ElfClass>
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| bool DwarfCFIRegisterNames(const typename ElfClass::Ehdr* elf_header,
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|                            std::vector<string>* register_names) {
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|   switch (elf_header->e_machine) {
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|     case EM_386:
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|       *register_names = DwarfCFIToModule::RegisterNames::I386();
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|       return true;
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|     case EM_ARM:
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|       *register_names = DwarfCFIToModule::RegisterNames::ARM();
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|       return true;
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|     case EM_MIPS:
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|       *register_names = DwarfCFIToModule::RegisterNames::MIPS();
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|       return true;
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|     case EM_X86_64:
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|       *register_names = DwarfCFIToModule::RegisterNames::X86_64();
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|       return true;
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|     default:
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|       return false;
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|   }
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| }
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| 
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| template<typename ElfClass>
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| bool LoadDwarfCFI(const string& dwarf_filename,
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|                   const typename ElfClass::Ehdr* elf_header,
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|                   const char* section_name,
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|                   const typename ElfClass::Shdr* section,
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|                   const bool eh_frame,
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|                   const typename ElfClass::Shdr* got_section,
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|                   const typename ElfClass::Shdr* text_section,
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|                   const bool big_endian,
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|                   Module* module) {
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|   // Find the appropriate set of register names for this file's
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|   // architecture.
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|   std::vector<string> register_names;
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|   if (!DwarfCFIRegisterNames<ElfClass>(elf_header, ®ister_names)) {
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|     fprintf(stderr, "%s: unrecognized ELF machine architecture '%d';"
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|             " cannot convert DWARF call frame information\n",
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|             dwarf_filename.c_str(), elf_header->e_machine);
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|     return false;
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|   }
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| 
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|   const dwarf2reader::Endianness endianness = big_endian ?
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|       dwarf2reader::ENDIANNESS_BIG : dwarf2reader::ENDIANNESS_LITTLE;
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| 
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|   // Find the call frame information and its size.
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|   const char* cfi =
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|       GetOffset<ElfClass, char>(elf_header, section->sh_offset);
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|   size_t cfi_size = section->sh_size;
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| 
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|   // Plug together the parser, handler, and their entourages.
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|   DwarfCFIToModule::Reporter module_reporter(dwarf_filename, section_name);
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|   DwarfCFIToModule handler(module, register_names, &module_reporter);
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|   dwarf2reader::ByteReader byte_reader(endianness);
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| 
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|   byte_reader.SetAddressSize(ElfClass::kAddrSize);
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| 
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|   // Provide the base addresses for .eh_frame encoded pointers, if
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|   // possible.
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|   byte_reader.SetCFIDataBase(section->sh_addr, cfi);
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|   if (got_section)
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|     byte_reader.SetDataBase(got_section->sh_addr);
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|   if (text_section)
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|     byte_reader.SetTextBase(text_section->sh_addr);
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| 
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|   dwarf2reader::CallFrameInfo::Reporter dwarf_reporter(dwarf_filename,
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|                                                        section_name);
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|   dwarf2reader::CallFrameInfo parser(cfi, cfi_size,
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|                                      &byte_reader, &handler, &dwarf_reporter,
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|                                      eh_frame);
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|   parser.Start();
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|   return true;
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| }
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| 
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| bool LoadELF(const string& obj_file, MmapWrapper* map_wrapper,
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|              void** elf_header) {
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|   int obj_fd = open(obj_file.c_str(), O_RDONLY);
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|   if (obj_fd < 0) {
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|     fprintf(stderr, "Failed to open ELF file '%s': %s\n",
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|             obj_file.c_str(), strerror(errno));
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|     return false;
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|   }
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|   FDWrapper obj_fd_wrapper(obj_fd);
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|   struct stat st;
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|   if (fstat(obj_fd, &st) != 0 && st.st_size <= 0) {
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|     fprintf(stderr, "Unable to fstat ELF file '%s': %s\n",
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|             obj_file.c_str(), strerror(errno));
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|     return false;
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|   }
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|   void *obj_base = mmap(NULL, st.st_size,
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|                         PROT_READ | PROT_WRITE, MAP_PRIVATE, obj_fd, 0);
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|   if (obj_base == MAP_FAILED) {
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|     fprintf(stderr, "Failed to mmap ELF file '%s': %s\n",
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|             obj_file.c_str(), strerror(errno));
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|     return false;
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|   }
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|   map_wrapper->set(obj_base, st.st_size);
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|   *elf_header = obj_base;
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|   if (!IsValidElf(*elf_header)) {
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|     fprintf(stderr, "Not a valid ELF file: %s\n", obj_file.c_str());
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|     return false;
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|   }
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|   return true;
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| }
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| 
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| // Get the endianness of ELF_HEADER. If it's invalid, return false.
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| template<typename ElfClass>
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| bool ElfEndianness(const typename ElfClass::Ehdr* elf_header,
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|                    bool* big_endian) {
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|   if (elf_header->e_ident[EI_DATA] == ELFDATA2LSB) {
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|     *big_endian = false;
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|     return true;
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|   }
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|   if (elf_header->e_ident[EI_DATA] == ELFDATA2MSB) {
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|     *big_endian = true;
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|     return true;
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|   }
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| 
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|   fprintf(stderr, "bad data encoding in ELF header: %d\n",
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|           elf_header->e_ident[EI_DATA]);
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|   return false;
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| }
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| 
 | |
| // Read the .gnu_debuglink and get the debug file name. If anything goes
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| // wrong, return an empty string.
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| template<typename ElfClass>
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| string ReadDebugLink(const char* debuglink,
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|                      size_t debuglink_size,
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|                      const string& obj_file,
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|                      const std::vector<string>& debug_dirs) {
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|   size_t debuglink_len = strlen(debuglink) + 5;  // '\0' + CRC32.
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|   debuglink_len = 4 * ((debuglink_len + 3) / 4);  // Round to nearest 4 bytes.
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| 
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|   // Sanity check.
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|   if (debuglink_len != debuglink_size) {
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|     fprintf(stderr, "Mismatched .gnu_debuglink string / section size: "
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|             "%zx %zx\n", debuglink_len, debuglink_size);
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|     return "";
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|   }
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| 
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|   bool found = false;
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|   int debuglink_fd = -1;
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|   string debuglink_path;
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|   std::vector<string>::const_iterator it;
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|   for (it = debug_dirs.begin(); it < debug_dirs.end(); ++it) {
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|     const string& debug_dir = *it;
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|     debuglink_path = debug_dir + "/" + debuglink;
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|     debuglink_fd = open(debuglink_path.c_str(), O_RDONLY);
 | |
|     if (debuglink_fd >= 0) {
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|       found = true;
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|       break;
 | |
|     }
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|   }
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| 
 | |
|   if (!found) {
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|     fprintf(stderr, "Failed to find debug ELF file for '%s' after trying:\n",
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|             obj_file.c_str());
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|     for (it = debug_dirs.begin(); it < debug_dirs.end(); ++it) {
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|       const string debug_dir = *it;
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|       fprintf(stderr, "  %s/%s\n", debug_dir.c_str(), debuglink);
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|     }
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|     return "";
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|   }
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| 
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|   FDWrapper debuglink_fd_wrapper(debuglink_fd);
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|   // TODO(thestig) check the CRC-32 at the end of the .gnu_debuglink
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|   // section.
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| 
 | |
|   return debuglink_path;
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| }
 | |
| 
 | |
| //
 | |
| // LoadSymbolsInfo
 | |
| //
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| // Holds the state between the two calls to LoadSymbols() in case it's necessary
 | |
| // to follow the .gnu_debuglink section and load debug information from a
 | |
| // different file.
 | |
| //
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| template<typename ElfClass>
 | |
| class LoadSymbolsInfo {
 | |
|  public:
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|   typedef typename ElfClass::Addr Addr;
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| 
 | |
|   explicit LoadSymbolsInfo(const std::vector<string>& dbg_dirs) :
 | |
|     debug_dirs_(dbg_dirs),
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|     has_loading_addr_(false) {}
 | |
| 
 | |
|   // Keeps track of which sections have been loaded so sections don't
 | |
|   // accidentally get loaded twice from two different files.
 | |
|   void LoadedSection(const string §ion) {
 | |
|     if (loaded_sections_.count(section) == 0) {
 | |
|       loaded_sections_.insert(section);
 | |
|     } else {
 | |
|       fprintf(stderr, "Section %s has already been loaded.\n",
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|               section.c_str());
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   // The ELF file and linked debug file are expected to have the same preferred
 | |
|   // loading address.
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|   void set_loading_addr(Addr addr, const string &filename) {
 | |
|     if (!has_loading_addr_) {
 | |
|       loading_addr_ = addr;
 | |
|       loaded_file_ = filename;
 | |
|       return;
 | |
|     }
 | |
| 
 | |
|     if (addr != loading_addr_) {
 | |
|       fprintf(stderr,
 | |
|               "ELF file '%s' and debug ELF file '%s' "
 | |
|               "have different load addresses.\n",
 | |
|               loaded_file_.c_str(), filename.c_str());
 | |
|       assert(false);
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   // Setters and getters
 | |
|   const std::vector<string>& debug_dirs() const {
 | |
|     return debug_dirs_;
 | |
|   }
 | |
| 
 | |
|   string debuglink_file() const {
 | |
|     return debuglink_file_;
 | |
|   }
 | |
|   void set_debuglink_file(string file) {
 | |
|     debuglink_file_ = file;
 | |
|   }
 | |
| 
 | |
|  private:
 | |
|   const std::vector<string>& debug_dirs_; // Directories in which to
 | |
|                                           // search for the debug ELF file.
 | |
| 
 | |
|   string debuglink_file_;  // Full path to the debug ELF file.
 | |
| 
 | |
|   bool has_loading_addr_;  // Indicate if LOADING_ADDR_ is valid.
 | |
| 
 | |
|   Addr loading_addr_;  // Saves the preferred loading address from the
 | |
|                        // first call to LoadSymbols().
 | |
| 
 | |
|   string loaded_file_;  // Name of the file loaded from the first call to
 | |
|                         // LoadSymbols().
 | |
| 
 | |
|   std::set<string> loaded_sections_;  // Tracks the Loaded ELF sections
 | |
|                                       // between calls to LoadSymbols().
 | |
| };
 | |
| 
 | |
| template<typename ElfClass>
 | |
| bool LoadSymbols(const string& obj_file,
 | |
|                  const bool big_endian,
 | |
|                  const typename ElfClass::Ehdr* elf_header,
 | |
|                  const bool read_gnu_debug_link,
 | |
|                  LoadSymbolsInfo<ElfClass>* info,
 | |
|                  const DumpOptions& options,
 | |
|                  Module* module) {
 | |
|   typedef typename ElfClass::Addr Addr;
 | |
|   typedef typename ElfClass::Phdr Phdr;
 | |
|   typedef typename ElfClass::Shdr Shdr;
 | |
|   typedef typename ElfClass::Word Word;
 | |
| 
 | |
|   Addr loading_addr = GetLoadingAddress<ElfClass>(
 | |
|       GetOffset<ElfClass, Phdr>(elf_header, elf_header->e_phoff),
 | |
|       elf_header->e_phnum);
 | |
|   module->SetLoadAddress(loading_addr);
 | |
|   info->set_loading_addr(loading_addr, obj_file);
 | |
| 
 | |
|   Word debug_section_type = 
 | |
|       elf_header->e_machine == EM_MIPS ? SHT_MIPS_DWARF : SHT_PROGBITS;
 | |
|   const Shdr* sections =
 | |
|       GetOffset<ElfClass, Shdr>(elf_header, elf_header->e_shoff);
 | |
|   const Shdr* section_names = sections + elf_header->e_shstrndx;
 | |
|   const char* names =
 | |
|       GetOffset<ElfClass, char>(elf_header, section_names->sh_offset);
 | |
|   const char *names_end = names + section_names->sh_size;
 | |
|   bool found_debug_info_section = false;
 | |
|   bool found_usable_info = false;
 | |
| 
 | |
|   if (options.symbol_data != ONLY_CFI) {
 | |
| #ifndef NO_STABS_SUPPORT
 | |
|     // Look for STABS debugging information, and load it if present.
 | |
|     const Shdr* stab_section =
 | |
|       FindElfSectionByName<ElfClass>(".stab", SHT_PROGBITS,
 | |
|                                      sections, names, names_end,
 | |
|                                      elf_header->e_shnum);
 | |
|     if (stab_section) {
 | |
|       const Shdr* stabstr_section = stab_section->sh_link + sections;
 | |
|       if (stabstr_section) {
 | |
|         found_debug_info_section = true;
 | |
|         found_usable_info = true;
 | |
|         info->LoadedSection(".stab");
 | |
|         if (!LoadStabs<ElfClass>(elf_header, stab_section, stabstr_section,
 | |
|                                  big_endian, module)) {
 | |
|           fprintf(stderr, "%s: \".stab\" section found, but failed to load"
 | |
|                   " STABS debugging information\n", obj_file.c_str());
 | |
|         }
 | |
|       }
 | |
|     }
 | |
| #endif  // NO_STABS_SUPPORT
 | |
| 
 | |
|     // Look for DWARF debugging information, and load it if present.
 | |
|     const Shdr* dwarf_section =
 | |
|       FindElfSectionByName<ElfClass>(".debug_info", debug_section_type,
 | |
|                                      sections, names, names_end,
 | |
|                                      elf_header->e_shnum);
 | |
|     if (dwarf_section) {
 | |
|       found_debug_info_section = true;
 | |
|       found_usable_info = true;
 | |
|       info->LoadedSection(".debug_info");
 | |
|       if (!LoadDwarf<ElfClass>(obj_file, elf_header, big_endian,
 | |
|                                options.handle_inter_cu_refs, module)) {
 | |
|         fprintf(stderr, "%s: \".debug_info\" section found, but failed to load "
 | |
|                 "DWARF debugging information\n", obj_file.c_str());
 | |
|       }
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   if (options.symbol_data != NO_CFI) {
 | |
|     // Dwarf Call Frame Information (CFI) is actually independent from
 | |
|     // the other DWARF debugging information, and can be used alone.
 | |
|     const Shdr* dwarf_cfi_section =
 | |
|         FindElfSectionByName<ElfClass>(".debug_frame", debug_section_type,
 | |
|                                        sections, names, names_end,
 | |
|                                        elf_header->e_shnum);
 | |
|     if (dwarf_cfi_section) {
 | |
|       // Ignore the return value of this function; even without call frame
 | |
|       // information, the other debugging information could be perfectly
 | |
|       // useful.
 | |
|       info->LoadedSection(".debug_frame");
 | |
|       bool result =
 | |
|           LoadDwarfCFI<ElfClass>(obj_file, elf_header, ".debug_frame",
 | |
|                                  dwarf_cfi_section, false, 0, 0, big_endian,
 | |
|                                  module);
 | |
|       found_usable_info = found_usable_info || result;
 | |
|     }
 | |
| 
 | |
|     // Linux C++ exception handling information can also provide
 | |
|     // unwinding data.
 | |
|     const Shdr* eh_frame_section =
 | |
|         FindElfSectionByName<ElfClass>(".eh_frame", SHT_PROGBITS,
 | |
|                                        sections, names, names_end,
 | |
|                                        elf_header->e_shnum);
 | |
|     if (eh_frame_section) {
 | |
|       // Pointers in .eh_frame data may be relative to the base addresses of
 | |
|       // certain sections. Provide those sections if present.
 | |
|       const Shdr* got_section =
 | |
|           FindElfSectionByName<ElfClass>(".got", SHT_PROGBITS,
 | |
|                                          sections, names, names_end,
 | |
|                                          elf_header->e_shnum);
 | |
|       const Shdr* text_section =
 | |
|           FindElfSectionByName<ElfClass>(".text", SHT_PROGBITS,
 | |
|                                          sections, names, names_end,
 | |
|                                          elf_header->e_shnum);
 | |
|       info->LoadedSection(".eh_frame");
 | |
|       // As above, ignore the return value of this function.
 | |
|       bool result =
 | |
|           LoadDwarfCFI<ElfClass>(obj_file, elf_header, ".eh_frame",
 | |
|                                  eh_frame_section, true,
 | |
|                                  got_section, text_section, big_endian, module);
 | |
|       found_usable_info = found_usable_info || result;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   if (!found_debug_info_section) {
 | |
|     fprintf(stderr, "%s: file contains no debugging information"
 | |
|             " (no \".stab\" or \".debug_info\" sections)\n",
 | |
|             obj_file.c_str());
 | |
| 
 | |
|     // Failed, but maybe there's a .gnu_debuglink section?
 | |
|     if (read_gnu_debug_link) {
 | |
|       const Shdr* gnu_debuglink_section
 | |
|           = FindElfSectionByName<ElfClass>(".gnu_debuglink", SHT_PROGBITS,
 | |
|                                            sections, names,
 | |
|                                            names_end, elf_header->e_shnum);
 | |
|       if (gnu_debuglink_section) {
 | |
|         if (!info->debug_dirs().empty()) {
 | |
|           const char* debuglink_contents =
 | |
|               GetOffset<ElfClass, char>(elf_header,
 | |
|                                         gnu_debuglink_section->sh_offset);
 | |
|           string debuglink_file
 | |
|               = ReadDebugLink<ElfClass>(debuglink_contents,
 | |
|                                         gnu_debuglink_section->sh_size,
 | |
|                                         obj_file, info->debug_dirs());
 | |
|           info->set_debuglink_file(debuglink_file);
 | |
|         } else {
 | |
|           fprintf(stderr, ".gnu_debuglink section found in '%s', "
 | |
|                   "but no debug path specified.\n", obj_file.c_str());
 | |
|         }
 | |
|       } else {
 | |
|         fprintf(stderr, "%s does not contain a .gnu_debuglink section.\n",
 | |
|                 obj_file.c_str());
 | |
|       }
 | |
|     } else {
 | |
|       if (options.symbol_data != ONLY_CFI) {
 | |
|         // The caller doesn't want to consult .gnu_debuglink.
 | |
|         // See if there are export symbols available.
 | |
|         const Shdr* dynsym_section =
 | |
|           FindElfSectionByName<ElfClass>(".dynsym", SHT_DYNSYM,
 | |
|                                          sections, names, names_end,
 | |
|                                          elf_header->e_shnum);
 | |
|         const Shdr* dynstr_section =
 | |
|           FindElfSectionByName<ElfClass>(".dynstr", SHT_STRTAB,
 | |
|                                          sections, names, names_end,
 | |
|                                          elf_header->e_shnum);
 | |
|         if (dynsym_section && dynstr_section) {
 | |
|           info->LoadedSection(".dynsym");
 | |
| 
 | |
|           const uint8_t* dynsyms =
 | |
|               GetOffset<ElfClass, uint8_t>(elf_header,
 | |
|                                            dynsym_section->sh_offset);
 | |
|           const uint8_t* dynstrs =
 | |
|               GetOffset<ElfClass, uint8_t>(elf_header,
 | |
|                                            dynstr_section->sh_offset);
 | |
|           bool result =
 | |
|               ELFSymbolsToModule(dynsyms,
 | |
|                                  dynsym_section->sh_size,
 | |
|                                  dynstrs,
 | |
|                                  dynstr_section->sh_size,
 | |
|                                  big_endian,
 | |
|                                  ElfClass::kAddrSize,
 | |
|                                  module);
 | |
|           found_usable_info = found_usable_info || result;
 | |
|         }
 | |
|       }
 | |
| 
 | |
|       // Return true if some usable information was found, since
 | |
|       // the caller doesn't want to use .gnu_debuglink.
 | |
|       return found_usable_info;
 | |
|     }
 | |
| 
 | |
|     // No debug info was found, let the user try again with .gnu_debuglink
 | |
|     // if present.
 | |
|     return false;
 | |
|   }
 | |
| 
 | |
|   return true;
 | |
| }
 | |
| 
 | |
| // Return the breakpad symbol file identifier for the architecture of
 | |
| // ELF_HEADER.
 | |
| template<typename ElfClass>
 | |
| const char* ElfArchitecture(const typename ElfClass::Ehdr* elf_header) {
 | |
|   typedef typename ElfClass::Half Half;
 | |
|   Half arch = elf_header->e_machine;
 | |
|   switch (arch) {
 | |
|     case EM_386:        return "x86";
 | |
|     case EM_ARM:        return "arm";
 | |
|     case EM_MIPS:       return "mips";
 | |
|     case EM_PPC64:      return "ppc64";
 | |
|     case EM_PPC:        return "ppc";
 | |
|     case EM_S390:       return "s390";
 | |
|     case EM_SPARC:      return "sparc";
 | |
|     case EM_SPARCV9:    return "sparcv9";
 | |
|     case EM_X86_64:     return "x86_64";
 | |
|     default: return NULL;
 | |
|   }
 | |
| }
 | |
| 
 | |
| // Format the Elf file identifier in IDENTIFIER as a UUID with the
 | |
| // dashes removed.
 | |
| string FormatIdentifier(unsigned char identifier[16]) {
 | |
|   char identifier_str[40];
 | |
|   google_breakpad::FileID::ConvertIdentifierToString(
 | |
|       identifier,
 | |
|       identifier_str,
 | |
|       sizeof(identifier_str));
 | |
|   string id_no_dash;
 | |
|   for (int i = 0; identifier_str[i] != '\0'; ++i)
 | |
|     if (identifier_str[i] != '-')
 | |
|       id_no_dash += identifier_str[i];
 | |
|   // Add an extra "0" by the end.  PDB files on Windows have an 'age'
 | |
|   // number appended to the end of the file identifier; this isn't
 | |
|   // really used or necessary on other platforms, but be consistent.
 | |
|   id_no_dash += '0';
 | |
|   return id_no_dash;
 | |
| }
 | |
| 
 | |
| // Return the non-directory portion of FILENAME: the portion after the
 | |
| // last slash, or the whole filename if there are no slashes.
 | |
| string BaseFileName(const string &filename) {
 | |
|   // Lots of copies!  basename's behavior is less than ideal.
 | |
|   char *c_filename = strdup(filename.c_str());
 | |
|   string base = basename(c_filename);
 | |
|   free(c_filename);
 | |
|   return base;
 | |
| }
 | |
| 
 | |
| template<typename ElfClass>
 | |
| bool ReadSymbolDataElfClass(const typename ElfClass::Ehdr* elf_header,
 | |
|                              const string& obj_filename,
 | |
|                              const std::vector<string>& debug_dirs,
 | |
|                              const DumpOptions& options,
 | |
|                              Module** out_module) {
 | |
|   typedef typename ElfClass::Ehdr Ehdr;
 | |
|   typedef typename ElfClass::Shdr Shdr;
 | |
| 
 | |
|   *out_module = NULL;
 | |
| 
 | |
|   unsigned char identifier[16];
 | |
|   if (!google_breakpad::FileID::ElfFileIdentifierFromMappedFile(elf_header,
 | |
|                                                                 identifier)) {
 | |
|     fprintf(stderr, "%s: unable to generate file identifier\n",
 | |
|             obj_filename.c_str());
 | |
|     return false;
 | |
|   }
 | |
| 
 | |
|   const char *architecture = ElfArchitecture<ElfClass>(elf_header);
 | |
|   if (!architecture) {
 | |
|     fprintf(stderr, "%s: unrecognized ELF machine architecture: %d\n",
 | |
|             obj_filename.c_str(), elf_header->e_machine);
 | |
|     return false;
 | |
|   }
 | |
| 
 | |
|   // Figure out what endianness this file is.
 | |
|   bool big_endian;
 | |
|   if (!ElfEndianness<ElfClass>(elf_header, &big_endian))
 | |
|     return false;
 | |
| 
 | |
|   string name = BaseFileName(obj_filename);
 | |
|   string os = "Linux";
 | |
|   string id = FormatIdentifier(identifier);
 | |
| 
 | |
|   LoadSymbolsInfo<ElfClass> info(debug_dirs);
 | |
|   scoped_ptr<Module> module(new Module(name, os, architecture, id));
 | |
|   if (!LoadSymbols<ElfClass>(obj_filename, big_endian, elf_header,
 | |
|                              !debug_dirs.empty(), &info,
 | |
|                              options, module.get())) {
 | |
|     const string debuglink_file = info.debuglink_file();
 | |
|     if (debuglink_file.empty())
 | |
|       return false;
 | |
| 
 | |
|     // Load debuglink ELF file.
 | |
|     fprintf(stderr, "Found debugging info in %s\n", debuglink_file.c_str());
 | |
|     MmapWrapper debug_map_wrapper;
 | |
|     Ehdr* debug_elf_header = NULL;
 | |
|     if (!LoadELF(debuglink_file, &debug_map_wrapper,
 | |
|                  reinterpret_cast<void**>(&debug_elf_header)))
 | |
|       return false;
 | |
|     // Sanity checks to make sure everything matches up.
 | |
|     const char *debug_architecture =
 | |
|         ElfArchitecture<ElfClass>(debug_elf_header);
 | |
|     if (!debug_architecture) {
 | |
|       fprintf(stderr, "%s: unrecognized ELF machine architecture: %d\n",
 | |
|               debuglink_file.c_str(), debug_elf_header->e_machine);
 | |
|       return false;
 | |
|     }
 | |
|     if (strcmp(architecture, debug_architecture)) {
 | |
|       fprintf(stderr, "%s with ELF machine architecture %s does not match "
 | |
|               "%s with ELF architecture %s\n",
 | |
|               debuglink_file.c_str(), debug_architecture,
 | |
|               obj_filename.c_str(), architecture);
 | |
|       return false;
 | |
|     }
 | |
| 
 | |
|     bool debug_big_endian;
 | |
|     if (!ElfEndianness<ElfClass>(debug_elf_header, &debug_big_endian))
 | |
|       return false;
 | |
|     if (debug_big_endian != big_endian) {
 | |
|       fprintf(stderr, "%s and %s does not match in endianness\n",
 | |
|               obj_filename.c_str(), debuglink_file.c_str());
 | |
|       return false;
 | |
|     }
 | |
| 
 | |
|     if (!LoadSymbols<ElfClass>(debuglink_file, debug_big_endian,
 | |
|                                debug_elf_header, false, &info,
 | |
|                                options, module.get())) {
 | |
|       return false;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   *out_module = module.release();
 | |
|   return true;
 | |
| }
 | |
| 
 | |
| }  // namespace
 | |
| 
 | |
| namespace google_breakpad {
 | |
| 
 | |
| // Not explicitly exported, but not static so it can be used in unit tests.
 | |
| bool ReadSymbolDataInternal(const uint8_t* obj_file,
 | |
|                             const string& obj_filename,
 | |
|                             const std::vector<string>& debug_dirs,
 | |
|                             const DumpOptions& options,
 | |
|                             Module** module) {
 | |
|   if (!IsValidElf(obj_file)) {
 | |
|     fprintf(stderr, "Not a valid ELF file: %s\n", obj_filename.c_str());
 | |
|     return false;
 | |
|   }
 | |
| 
 | |
|   int elfclass = ElfClass(obj_file);
 | |
|   if (elfclass == ELFCLASS32) {
 | |
|     return ReadSymbolDataElfClass<ElfClass32>(
 | |
|         reinterpret_cast<const Elf32_Ehdr*>(obj_file), obj_filename, debug_dirs,
 | |
|         options, module);
 | |
|   }
 | |
|   if (elfclass == ELFCLASS64) {
 | |
|     return ReadSymbolDataElfClass<ElfClass64>(
 | |
|         reinterpret_cast<const Elf64_Ehdr*>(obj_file), obj_filename, debug_dirs,
 | |
|         options, module);
 | |
|   }
 | |
| 
 | |
|   return false;
 | |
| }
 | |
| 
 | |
| bool WriteSymbolFile(const string &obj_file,
 | |
|                      const std::vector<string>& debug_dirs,
 | |
|                      const DumpOptions& options,
 | |
|                      std::ostream &sym_stream) {
 | |
|   Module* module;
 | |
|   if (!ReadSymbolData(obj_file, debug_dirs, options, &module))
 | |
|     return false;
 | |
| 
 | |
|   bool result = module->Write(sym_stream, options.symbol_data);
 | |
|   delete module;
 | |
|   return result;
 | |
| }
 | |
| 
 | |
| bool ReadSymbolData(const string& obj_file,
 | |
|                     const std::vector<string>& debug_dirs,
 | |
|                     const DumpOptions& options,
 | |
|                     Module** module) {
 | |
|   MmapWrapper map_wrapper;
 | |
|   void* elf_header = NULL;
 | |
|   if (!LoadELF(obj_file, &map_wrapper, &elf_header))
 | |
|     return false;
 | |
| 
 | |
|   return ReadSymbolDataInternal(reinterpret_cast<uint8_t*>(elf_header),
 | |
|                                 obj_file, debug_dirs, options, module);
 | |
| }
 | |
| 
 | |
| }  // namespace google_breakpad
 |