2344 lines
		
	
	
		
			82 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			2344 lines
		
	
	
		
			82 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| // Copyright (c) 2010 Google Inc. All Rights Reserved.
 | |
| //
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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
 | |
| // 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
 | |
| // 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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| // CFI reader author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>
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| 
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| // Implementation of dwarf2reader::LineInfo, dwarf2reader::CompilationUnit,
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| // and dwarf2reader::CallFrameInfo. See dwarf2reader.h for details.
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| 
 | |
| #include "common/dwarf/dwarf2reader.h"
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| 
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| #include <assert.h>
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| #include <stdint.h>
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| #include <stdio.h>
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| #include <string.h>
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| 
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| #include <map>
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| #include <memory>
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| #include <stack>
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| #include <string>
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| #include <utility>
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| 
 | |
| #include "common/dwarf/bytereader-inl.h"
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| #include "common/dwarf/bytereader.h"
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| #include "common/dwarf/line_state_machine.h"
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| #include "common/using_std_string.h"
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| 
 | |
| namespace dwarf2reader {
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| 
 | |
| CompilationUnit::CompilationUnit(const SectionMap& sections, uint64 offset,
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|                                  ByteReader* reader, Dwarf2Handler* handler)
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|     : offset_from_section_start_(offset), reader_(reader),
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|       sections_(sections), handler_(handler), abbrevs_(NULL),
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|       string_buffer_(NULL), string_buffer_length_(0) {}
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| 
 | |
| // Read a DWARF2/3 abbreviation section.
 | |
| // Each abbrev consists of a abbreviation number, a tag, a byte
 | |
| // specifying whether the tag has children, and a list of
 | |
| // attribute/form pairs.
 | |
| // The list of forms is terminated by a 0 for the attribute, and a
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| // zero for the form.  The entire abbreviation section is terminated
 | |
| // by a zero for the code.
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| 
 | |
| void CompilationUnit::ReadAbbrevs() {
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|   if (abbrevs_)
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|     return;
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| 
 | |
|   // First get the debug_abbrev section.  ".debug_abbrev" is the name
 | |
|   // recommended in the DWARF spec, and used on Linux;
 | |
|   // "__debug_abbrev" is the name used in Mac OS X Mach-O files.
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|   SectionMap::const_iterator iter = sections_.find(".debug_abbrev");
 | |
|   if (iter == sections_.end())
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|     iter = sections_.find("__debug_abbrev");
 | |
|   assert(iter != sections_.end());
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| 
 | |
|   abbrevs_ = new std::vector<Abbrev>;
 | |
|   abbrevs_->resize(1);
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| 
 | |
|   // The only way to check whether we are reading over the end of the
 | |
|   // buffer would be to first compute the size of the leb128 data by
 | |
|   // reading it, then go back and read it again.
 | |
|   const char* abbrev_start = iter->second.first +
 | |
|                                       header_.abbrev_offset;
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|   const char* abbrevptr = abbrev_start;
 | |
| #ifndef NDEBUG
 | |
|   const uint64 abbrev_length = iter->second.second - header_.abbrev_offset;
 | |
| #endif
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| 
 | |
|   while (1) {
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|     CompilationUnit::Abbrev abbrev;
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|     size_t len;
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|     const uint64 number = reader_->ReadUnsignedLEB128(abbrevptr, &len);
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| 
 | |
|     if (number == 0)
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|       break;
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|     abbrev.number = number;
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|     abbrevptr += len;
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| 
 | |
|     assert(abbrevptr < abbrev_start + abbrev_length);
 | |
|     const uint64 tag = reader_->ReadUnsignedLEB128(abbrevptr, &len);
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|     abbrevptr += len;
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|     abbrev.tag = static_cast<enum DwarfTag>(tag);
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| 
 | |
|     assert(abbrevptr < abbrev_start + abbrev_length);
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|     abbrev.has_children = reader_->ReadOneByte(abbrevptr);
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|     abbrevptr += 1;
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| 
 | |
|     assert(abbrevptr < abbrev_start + abbrev_length);
 | |
| 
 | |
|     while (1) {
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|       const uint64 nametemp = reader_->ReadUnsignedLEB128(abbrevptr, &len);
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|       abbrevptr += len;
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| 
 | |
|       assert(abbrevptr < abbrev_start + abbrev_length);
 | |
|       const uint64 formtemp = reader_->ReadUnsignedLEB128(abbrevptr, &len);
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|       abbrevptr += len;
 | |
|       if (nametemp == 0 && formtemp == 0)
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|         break;
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| 
 | |
|       const enum DwarfAttribute name =
 | |
|         static_cast<enum DwarfAttribute>(nametemp);
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|       const enum DwarfForm form = static_cast<enum DwarfForm>(formtemp);
 | |
|       abbrev.attributes.push_back(std::make_pair(name, form));
 | |
|     }
 | |
|     assert(abbrev.number == abbrevs_->size());
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|     abbrevs_->push_back(abbrev);
 | |
|   }
 | |
| }
 | |
| 
 | |
| // Skips a single DIE's attributes.
 | |
| const char* CompilationUnit::SkipDIE(const char* start,
 | |
|                                               const Abbrev& abbrev) {
 | |
|   for (AttributeList::const_iterator i = abbrev.attributes.begin();
 | |
|        i != abbrev.attributes.end();
 | |
|        i++)  {
 | |
|     start = SkipAttribute(start, i->second);
 | |
|   }
 | |
|   return start;
 | |
| }
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| 
 | |
| // Skips a single attribute form's data.
 | |
| const char* CompilationUnit::SkipAttribute(const char* start,
 | |
|                                                     enum DwarfForm form) {
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|   size_t len;
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| 
 | |
|   switch (form) {
 | |
|     case DW_FORM_indirect:
 | |
|       form = static_cast<enum DwarfForm>(reader_->ReadUnsignedLEB128(start,
 | |
|                                                                      &len));
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|       start += len;
 | |
|       return SkipAttribute(start, form);
 | |
| 
 | |
|     case DW_FORM_flag_present:
 | |
|       return start;
 | |
|     case DW_FORM_data1:
 | |
|     case DW_FORM_flag:
 | |
|     case DW_FORM_ref1:
 | |
|       return start + 1;
 | |
|     case DW_FORM_ref2:
 | |
|     case DW_FORM_data2:
 | |
|       return start + 2;
 | |
|     case DW_FORM_ref4:
 | |
|     case DW_FORM_data4:
 | |
|       return start + 4;
 | |
|     case DW_FORM_ref8:
 | |
|     case DW_FORM_data8:
 | |
|     case DW_FORM_ref_sig8:
 | |
|       return start + 8;
 | |
|     case DW_FORM_string:
 | |
|       return start + strlen(start) + 1;
 | |
|     case DW_FORM_udata:
 | |
|     case DW_FORM_ref_udata:
 | |
|       reader_->ReadUnsignedLEB128(start, &len);
 | |
|       return start + len;
 | |
| 
 | |
|     case DW_FORM_sdata:
 | |
|       reader_->ReadSignedLEB128(start, &len);
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|       return start + len;
 | |
|     case DW_FORM_addr:
 | |
|       return start + reader_->AddressSize();
 | |
|     case DW_FORM_ref_addr:
 | |
|       // DWARF2 and 3 differ on whether ref_addr is address size or
 | |
|       // offset size.
 | |
|       assert(header_.version == 2 || header_.version == 3);
 | |
|       if (header_.version == 2) {
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|         return start + reader_->AddressSize();
 | |
|       } else if (header_.version == 3) {
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|         return start + reader_->OffsetSize();
 | |
|       }
 | |
| 
 | |
|     case DW_FORM_block1:
 | |
|       return start + 1 + reader_->ReadOneByte(start);
 | |
|     case DW_FORM_block2:
 | |
|       return start + 2 + reader_->ReadTwoBytes(start);
 | |
|     case DW_FORM_block4:
 | |
|       return start + 4 + reader_->ReadFourBytes(start);
 | |
|     case DW_FORM_block:
 | |
|     case DW_FORM_exprloc: {
 | |
|       uint64 size = reader_->ReadUnsignedLEB128(start, &len);
 | |
|       return start + size + len;
 | |
|     }
 | |
|     case DW_FORM_strp:
 | |
|     case DW_FORM_sec_offset:
 | |
|       return start + reader_->OffsetSize();
 | |
|   }
 | |
|   fprintf(stderr,"Unhandled form type");
 | |
|   return NULL;
 | |
| }
 | |
| 
 | |
| // Read a DWARF2/3 header.
 | |
| // The header is variable length in DWARF3 (and DWARF2 as extended by
 | |
| // most compilers), and consists of an length field, a version number,
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| // the offset in the .debug_abbrev section for our abbrevs, and an
 | |
| // address size.
 | |
| void CompilationUnit::ReadHeader() {
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|   const char* headerptr = buffer_;
 | |
|   size_t initial_length_size;
 | |
| 
 | |
|   assert(headerptr + 4 < buffer_ + buffer_length_);
 | |
|   const uint64 initial_length
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|     = reader_->ReadInitialLength(headerptr, &initial_length_size);
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|   headerptr += initial_length_size;
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|   header_.length = initial_length;
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| 
 | |
|   assert(headerptr + 2 < buffer_ + buffer_length_);
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|   header_.version = reader_->ReadTwoBytes(headerptr);
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|   headerptr += 2;
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| 
 | |
|   assert(headerptr + reader_->OffsetSize() < buffer_ + buffer_length_);
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|   header_.abbrev_offset = reader_->ReadOffset(headerptr);
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|   headerptr += reader_->OffsetSize();
 | |
| 
 | |
|   assert(headerptr + 1 < buffer_ + buffer_length_);
 | |
|   header_.address_size = reader_->ReadOneByte(headerptr);
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|   reader_->SetAddressSize(header_.address_size);
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|   headerptr += 1;
 | |
| 
 | |
|   after_header_ = headerptr;
 | |
| 
 | |
|   // This check ensures that we don't have to do checking during the
 | |
|   // reading of DIEs. header_.length does not include the size of the
 | |
|   // initial length.
 | |
|   assert(buffer_ + initial_length_size + header_.length <=
 | |
|         buffer_ + buffer_length_);
 | |
| }
 | |
| 
 | |
| uint64 CompilationUnit::Start() {
 | |
|   // First get the debug_info section.  ".debug_info" is the name
 | |
|   // recommended in the DWARF spec, and used on Linux; "__debug_info"
 | |
|   // is the name used in Mac OS X Mach-O files.
 | |
|   SectionMap::const_iterator iter = sections_.find(".debug_info");
 | |
|   if (iter == sections_.end())
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|     iter = sections_.find("__debug_info");
 | |
|   assert(iter != sections_.end());
 | |
| 
 | |
|   // Set up our buffer
 | |
|   buffer_ = iter->second.first + offset_from_section_start_;
 | |
|   buffer_length_ = iter->second.second - offset_from_section_start_;
 | |
| 
 | |
|   // Read the header
 | |
|   ReadHeader();
 | |
| 
 | |
|   // Figure out the real length from the end of the initial length to
 | |
|   // the end of the compilation unit, since that is the value we
 | |
|   // return.
 | |
|   uint64 ourlength = header_.length;
 | |
|   if (reader_->OffsetSize() == 8)
 | |
|     ourlength += 12;
 | |
|   else
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|     ourlength += 4;
 | |
| 
 | |
|   // See if the user wants this compilation unit, and if not, just return.
 | |
|   if (!handler_->StartCompilationUnit(offset_from_section_start_,
 | |
|                                       reader_->AddressSize(),
 | |
|                                       reader_->OffsetSize(),
 | |
|                                       header_.length,
 | |
|                                       header_.version))
 | |
|     return ourlength;
 | |
| 
 | |
|   // Otherwise, continue by reading our abbreviation entries.
 | |
|   ReadAbbrevs();
 | |
| 
 | |
|   // Set the string section if we have one.  ".debug_str" is the name
 | |
|   // recommended in the DWARF spec, and used on Linux; "__debug_str"
 | |
|   // is the name used in Mac OS X Mach-O files.
 | |
|   iter = sections_.find(".debug_str");
 | |
|   if (iter == sections_.end())
 | |
|     iter = sections_.find("__debug_str");
 | |
|   if (iter != sections_.end()) {
 | |
|     string_buffer_ = iter->second.first;
 | |
|     string_buffer_length_ = iter->second.second;
 | |
|   }
 | |
| 
 | |
|   // Now that we have our abbreviations, start processing DIE's.
 | |
|   ProcessDIEs();
 | |
| 
 | |
|   return ourlength;
 | |
| }
 | |
| 
 | |
| // If one really wanted, you could merge SkipAttribute and
 | |
| // ProcessAttribute
 | |
| // This is all boring data manipulation and calling of the handler.
 | |
| const char* CompilationUnit::ProcessAttribute(
 | |
|     uint64 dieoffset, const char* start, enum DwarfAttribute attr,
 | |
|     enum DwarfForm form) {
 | |
|   size_t len;
 | |
| 
 | |
|   switch (form) {
 | |
|     // DW_FORM_indirect is never used because it is such a space
 | |
|     // waster.
 | |
|     case DW_FORM_indirect:
 | |
|       form = static_cast<enum DwarfForm>(reader_->ReadUnsignedLEB128(start,
 | |
|                                                                      &len));
 | |
|       start += len;
 | |
|       return ProcessAttribute(dieoffset, start, attr, form);
 | |
| 
 | |
|     case DW_FORM_flag_present:
 | |
|       handler_->ProcessAttributeUnsigned(dieoffset, attr, form, 1);
 | |
|       return start;
 | |
|     case DW_FORM_data1:
 | |
|     case DW_FORM_flag:
 | |
|       handler_->ProcessAttributeUnsigned(dieoffset, attr, form,
 | |
|                                          reader_->ReadOneByte(start));
 | |
|       return start + 1;
 | |
|     case DW_FORM_data2:
 | |
|       handler_->ProcessAttributeUnsigned(dieoffset, attr, form,
 | |
|                                          reader_->ReadTwoBytes(start));
 | |
|       return start + 2;
 | |
|     case DW_FORM_data4:
 | |
|       handler_->ProcessAttributeUnsigned(dieoffset, attr, form,
 | |
|                                          reader_->ReadFourBytes(start));
 | |
|       return start + 4;
 | |
|     case DW_FORM_data8:
 | |
|       handler_->ProcessAttributeUnsigned(dieoffset, attr, form,
 | |
|                                          reader_->ReadEightBytes(start));
 | |
|       return start + 8;
 | |
|     case DW_FORM_string: {
 | |
|       const char* str = start;
 | |
|       handler_->ProcessAttributeString(dieoffset, attr, form,
 | |
|                                        str);
 | |
|       return start + strlen(str) + 1;
 | |
|     }
 | |
|     case DW_FORM_udata:
 | |
|       handler_->ProcessAttributeUnsigned(dieoffset, attr, form,
 | |
|                                          reader_->ReadUnsignedLEB128(start,
 | |
|                                                                      &len));
 | |
|       return start + len;
 | |
| 
 | |
|     case DW_FORM_sdata:
 | |
|       handler_->ProcessAttributeSigned(dieoffset, attr, form,
 | |
|                                       reader_->ReadSignedLEB128(start, &len));
 | |
|       return start + len;
 | |
|     case DW_FORM_addr:
 | |
|       handler_->ProcessAttributeUnsigned(dieoffset, attr, form,
 | |
|                                          reader_->ReadAddress(start));
 | |
|       return start + reader_->AddressSize();
 | |
|     case DW_FORM_sec_offset:
 | |
|       handler_->ProcessAttributeUnsigned(dieoffset, attr, form,
 | |
|                                          reader_->ReadOffset(start));
 | |
|       return start + reader_->OffsetSize();
 | |
| 
 | |
|     case DW_FORM_ref1:
 | |
|       handler_->ProcessAttributeReference(dieoffset, attr, form,
 | |
|                                           reader_->ReadOneByte(start)
 | |
|                                           + offset_from_section_start_);
 | |
|       return start + 1;
 | |
|     case DW_FORM_ref2:
 | |
|       handler_->ProcessAttributeReference(dieoffset, attr, form,
 | |
|                                           reader_->ReadTwoBytes(start)
 | |
|                                           + offset_from_section_start_);
 | |
|       return start + 2;
 | |
|     case DW_FORM_ref4:
 | |
|       handler_->ProcessAttributeReference(dieoffset, attr, form,
 | |
|                                           reader_->ReadFourBytes(start)
 | |
|                                           + offset_from_section_start_);
 | |
|       return start + 4;
 | |
|     case DW_FORM_ref8:
 | |
|       handler_->ProcessAttributeReference(dieoffset, attr, form,
 | |
|                                           reader_->ReadEightBytes(start)
 | |
|                                           + offset_from_section_start_);
 | |
|       return start + 8;
 | |
|     case DW_FORM_ref_udata:
 | |
|       handler_->ProcessAttributeReference(dieoffset, attr, form,
 | |
|                                           reader_->ReadUnsignedLEB128(start,
 | |
|                                                                       &len)
 | |
|                                           + offset_from_section_start_);
 | |
|       return start + len;
 | |
|     case DW_FORM_ref_addr:
 | |
|       // DWARF2 and 3 differ on whether ref_addr is address size or
 | |
|       // offset size.
 | |
|       assert(header_.version == 2 || header_.version == 3);
 | |
|       if (header_.version == 2) {
 | |
|         handler_->ProcessAttributeReference(dieoffset, attr, form,
 | |
|                                             reader_->ReadAddress(start));
 | |
|         return start + reader_->AddressSize();
 | |
|       } else if (header_.version == 3) {
 | |
|         handler_->ProcessAttributeReference(dieoffset, attr, form,
 | |
|                                             reader_->ReadOffset(start));
 | |
|         return start + reader_->OffsetSize();
 | |
|       }
 | |
|       break;
 | |
|     case DW_FORM_ref_sig8:
 | |
|       handler_->ProcessAttributeSignature(dieoffset, attr, form,
 | |
|                                           reader_->ReadEightBytes(start));
 | |
|       return start + 8;
 | |
| 
 | |
|     case DW_FORM_block1: {
 | |
|       uint64 datalen = reader_->ReadOneByte(start);
 | |
|       handler_->ProcessAttributeBuffer(dieoffset, attr, form, start + 1,
 | |
|                                        datalen);
 | |
|       return start + 1 + datalen;
 | |
|     }
 | |
|     case DW_FORM_block2: {
 | |
|       uint64 datalen = reader_->ReadTwoBytes(start);
 | |
|       handler_->ProcessAttributeBuffer(dieoffset, attr, form, start + 2,
 | |
|                                        datalen);
 | |
|       return start + 2 + datalen;
 | |
|     }
 | |
|     case DW_FORM_block4: {
 | |
|       uint64 datalen = reader_->ReadFourBytes(start);
 | |
|       handler_->ProcessAttributeBuffer(dieoffset, attr, form, start + 4,
 | |
|                                        datalen);
 | |
|       return start + 4 + datalen;
 | |
|     }
 | |
|     case DW_FORM_block:
 | |
|     case DW_FORM_exprloc: {
 | |
|       uint64 datalen = reader_->ReadUnsignedLEB128(start, &len);
 | |
|       handler_->ProcessAttributeBuffer(dieoffset, attr, form, start + len,
 | |
|                                        datalen);
 | |
|       return start + datalen + len;
 | |
|     }
 | |
|     case DW_FORM_strp: {
 | |
|       assert(string_buffer_ != NULL);
 | |
| 
 | |
|       const uint64 offset = reader_->ReadOffset(start);
 | |
|       assert(string_buffer_ + offset < string_buffer_ + string_buffer_length_);
 | |
| 
 | |
|       const char* str = string_buffer_ + offset;
 | |
|       handler_->ProcessAttributeString(dieoffset, attr, form,
 | |
|                                        str);
 | |
|       return start + reader_->OffsetSize();
 | |
|     }
 | |
|   }
 | |
|   fprintf(stderr, "Unhandled form type\n");
 | |
|   return NULL;
 | |
| }
 | |
| 
 | |
| const char* CompilationUnit::ProcessDIE(uint64 dieoffset,
 | |
|                                                  const char* start,
 | |
|                                                  const Abbrev& abbrev) {
 | |
|   for (AttributeList::const_iterator i = abbrev.attributes.begin();
 | |
|        i != abbrev.attributes.end();
 | |
|        i++)  {
 | |
|     start = ProcessAttribute(dieoffset, start, i->first, i->second);
 | |
|   }
 | |
|   return start;
 | |
| }
 | |
| 
 | |
| void CompilationUnit::ProcessDIEs() {
 | |
|   const char* dieptr = after_header_;
 | |
|   size_t len;
 | |
| 
 | |
|   // lengthstart is the place the length field is based on.
 | |
|   // It is the point in the header after the initial length field
 | |
|   const char* lengthstart = buffer_;
 | |
| 
 | |
|   // In 64 bit dwarf, the initial length is 12 bytes, because of the
 | |
|   // 0xffffffff at the start.
 | |
|   if (reader_->OffsetSize() == 8)
 | |
|     lengthstart += 12;
 | |
|   else
 | |
|     lengthstart += 4;
 | |
| 
 | |
|   std::stack<uint64> die_stack;
 | |
|   
 | |
|   while (dieptr < (lengthstart + header_.length)) {
 | |
|     // We give the user the absolute offset from the beginning of
 | |
|     // debug_info, since they need it to deal with ref_addr forms.
 | |
|     uint64 absolute_offset = (dieptr - buffer_) + offset_from_section_start_;
 | |
| 
 | |
|     uint64 abbrev_num = reader_->ReadUnsignedLEB128(dieptr, &len);
 | |
| 
 | |
|     dieptr += len;
 | |
| 
 | |
|     // Abbrev == 0 represents the end of a list of children, or padding
 | |
|     // at the end of the compilation unit.
 | |
|     if (abbrev_num == 0) {
 | |
|       if (die_stack.size() == 0)
 | |
|         // If it is padding, then we are done with the compilation unit's DIEs.
 | |
|         return;
 | |
|       const uint64 offset = die_stack.top();
 | |
|       die_stack.pop();
 | |
|       handler_->EndDIE(offset);
 | |
|       continue;
 | |
|     }
 | |
| 
 | |
|     const Abbrev& abbrev = abbrevs_->at(static_cast<size_t>(abbrev_num));
 | |
|     const enum DwarfTag tag = abbrev.tag;
 | |
|     if (!handler_->StartDIE(absolute_offset, tag)) {
 | |
|       dieptr = SkipDIE(dieptr, abbrev);
 | |
|     } else {
 | |
|       dieptr = ProcessDIE(absolute_offset, dieptr, abbrev);
 | |
|     }
 | |
| 
 | |
|     if (abbrev.has_children) {
 | |
|       die_stack.push(absolute_offset);
 | |
|     } else {
 | |
|       handler_->EndDIE(absolute_offset);
 | |
|     }
 | |
|   }
 | |
| }
 | |
| 
 | |
| LineInfo::LineInfo(const char* buffer, uint64 buffer_length,
 | |
|                    ByteReader* reader, LineInfoHandler* handler):
 | |
|     handler_(handler), reader_(reader), buffer_(buffer),
 | |
|     buffer_length_(buffer_length) {
 | |
|   header_.std_opcode_lengths = NULL;
 | |
| }
 | |
| 
 | |
| uint64 LineInfo::Start() {
 | |
|   ReadHeader();
 | |
|   ReadLines();
 | |
|   return after_header_ - buffer_;
 | |
| }
 | |
| 
 | |
| // The header for a debug_line section is mildly complicated, because
 | |
| // the line info is very tightly encoded.
 | |
| void LineInfo::ReadHeader() {
 | |
|   const char* lineptr = buffer_;
 | |
|   size_t initial_length_size;
 | |
| 
 | |
|   const uint64 initial_length
 | |
|     = reader_->ReadInitialLength(lineptr, &initial_length_size);
 | |
| 
 | |
|   lineptr += initial_length_size;
 | |
|   header_.total_length = initial_length;
 | |
|   assert(buffer_ + initial_length_size + header_.total_length <=
 | |
|         buffer_ + buffer_length_);
 | |
| 
 | |
|   // Address size *must* be set by CU ahead of time.
 | |
|   assert(reader_->AddressSize() != 0);
 | |
| 
 | |
|   header_.version = reader_->ReadTwoBytes(lineptr);
 | |
|   lineptr += 2;
 | |
| 
 | |
|   header_.prologue_length = reader_->ReadOffset(lineptr);
 | |
|   lineptr += reader_->OffsetSize();
 | |
| 
 | |
|   header_.min_insn_length = reader_->ReadOneByte(lineptr);
 | |
|   lineptr += 1;
 | |
| 
 | |
|   header_.default_is_stmt = reader_->ReadOneByte(lineptr);
 | |
|   lineptr += 1;
 | |
| 
 | |
|   header_.line_base = *reinterpret_cast<const int8*>(lineptr);
 | |
|   lineptr += 1;
 | |
| 
 | |
|   header_.line_range = reader_->ReadOneByte(lineptr);
 | |
|   lineptr += 1;
 | |
| 
 | |
|   header_.opcode_base = reader_->ReadOneByte(lineptr);
 | |
|   lineptr += 1;
 | |
| 
 | |
|   header_.std_opcode_lengths = new std::vector<unsigned char>;
 | |
|   header_.std_opcode_lengths->resize(header_.opcode_base + 1);
 | |
|   (*header_.std_opcode_lengths)[0] = 0;
 | |
|   for (int i = 1; i < header_.opcode_base; i++) {
 | |
|     (*header_.std_opcode_lengths)[i] = reader_->ReadOneByte(lineptr);
 | |
|     lineptr += 1;
 | |
|   }
 | |
| 
 | |
|   // It is legal for the directory entry table to be empty.
 | |
|   if (*lineptr) {
 | |
|     uint32 dirindex = 1;
 | |
|     while (*lineptr) {
 | |
|       const char* dirname = lineptr;
 | |
|       handler_->DefineDir(dirname, dirindex);
 | |
|       lineptr += strlen(dirname) + 1;
 | |
|       dirindex++;
 | |
|     }
 | |
|   }
 | |
|   lineptr++;
 | |
| 
 | |
|   // It is also legal for the file entry table to be empty.
 | |
|   if (*lineptr) {
 | |
|     uint32 fileindex = 1;
 | |
|     size_t len;
 | |
|     while (*lineptr) {
 | |
|       const char* filename = lineptr;
 | |
|       lineptr += strlen(filename) + 1;
 | |
| 
 | |
|       uint64 dirindex = reader_->ReadUnsignedLEB128(lineptr, &len);
 | |
|       lineptr += len;
 | |
| 
 | |
|       uint64 mod_time = reader_->ReadUnsignedLEB128(lineptr, &len);
 | |
|       lineptr += len;
 | |
| 
 | |
|       uint64 filelength = reader_->ReadUnsignedLEB128(lineptr, &len);
 | |
|       lineptr += len;
 | |
|       handler_->DefineFile(filename, fileindex, static_cast<uint32>(dirindex), 
 | |
|                            mod_time, filelength);
 | |
|       fileindex++;
 | |
|     }
 | |
|   }
 | |
|   lineptr++;
 | |
| 
 | |
|   after_header_ = lineptr;
 | |
| }
 | |
| 
 | |
| /* static */
 | |
| bool LineInfo::ProcessOneOpcode(ByteReader* reader,
 | |
|                                 LineInfoHandler* handler,
 | |
|                                 const struct LineInfoHeader &header,
 | |
|                                 const char* start,
 | |
|                                 struct LineStateMachine* lsm,
 | |
|                                 size_t* len,
 | |
|                                 uintptr pc,
 | |
|                                 bool *lsm_passes_pc) {
 | |
|   size_t oplen = 0;
 | |
|   size_t templen;
 | |
|   uint8 opcode = reader->ReadOneByte(start);
 | |
|   oplen++;
 | |
|   start++;
 | |
| 
 | |
|   // If the opcode is great than the opcode_base, it is a special
 | |
|   // opcode. Most line programs consist mainly of special opcodes.
 | |
|   if (opcode >= header.opcode_base) {
 | |
|     opcode -= header.opcode_base;
 | |
|     const int64 advance_address = (opcode / header.line_range)
 | |
|                                   * header.min_insn_length;
 | |
|     const int32 advance_line = (opcode % header.line_range)
 | |
|                                + header.line_base;
 | |
| 
 | |
|     // Check if the lsm passes "pc". If so, mark it as passed.
 | |
|     if (lsm_passes_pc &&
 | |
|         lsm->address <= pc && pc < lsm->address + advance_address) {
 | |
|       *lsm_passes_pc = true;
 | |
|     }
 | |
| 
 | |
|     lsm->address += advance_address;
 | |
|     lsm->line_num += advance_line;
 | |
|     lsm->basic_block = true;
 | |
|     *len = oplen;
 | |
|     return true;
 | |
|   }
 | |
| 
 | |
|   // Otherwise, we have the regular opcodes
 | |
|   switch (opcode) {
 | |
|     case DW_LNS_copy: {
 | |
|       lsm->basic_block = false;
 | |
|       *len = oplen;
 | |
|       return true;
 | |
|     }
 | |
| 
 | |
|     case DW_LNS_advance_pc: {
 | |
|       uint64 advance_address = reader->ReadUnsignedLEB128(start, &templen);
 | |
|       oplen += templen;
 | |
| 
 | |
|       // Check if the lsm passes "pc". If so, mark it as passed.
 | |
|       if (lsm_passes_pc && lsm->address <= pc &&
 | |
|           pc < lsm->address + header.min_insn_length * advance_address) {
 | |
|         *lsm_passes_pc = true;
 | |
|       }
 | |
| 
 | |
|       lsm->address += header.min_insn_length * advance_address;
 | |
|     }
 | |
|       break;
 | |
|     case DW_LNS_advance_line: {
 | |
|       const int64 advance_line = reader->ReadSignedLEB128(start, &templen);
 | |
|       oplen += templen;
 | |
|       lsm->line_num += static_cast<int32>(advance_line);
 | |
| 
 | |
|       // With gcc 4.2.1, we can get the line_no here for the first time
 | |
|       // since DW_LNS_advance_line is called after DW_LNE_set_address is
 | |
|       // called. So we check if the lsm passes "pc" here, not in
 | |
|       // DW_LNE_set_address.
 | |
|       if (lsm_passes_pc && lsm->address == pc) {
 | |
|         *lsm_passes_pc = true;
 | |
|       }
 | |
|     }
 | |
|       break;
 | |
|     case DW_LNS_set_file: {
 | |
|       const uint64 fileno = reader->ReadUnsignedLEB128(start, &templen);
 | |
|       oplen += templen;
 | |
|       lsm->file_num = static_cast<uint32>(fileno);
 | |
|     }
 | |
|       break;
 | |
|     case DW_LNS_set_column: {
 | |
|       const uint64 colno = reader->ReadUnsignedLEB128(start, &templen);
 | |
|       oplen += templen;
 | |
|       lsm->column_num = static_cast<uint32>(colno);
 | |
|     }
 | |
|       break;
 | |
|     case DW_LNS_negate_stmt: {
 | |
|       lsm->is_stmt = !lsm->is_stmt;
 | |
|     }
 | |
|       break;
 | |
|     case DW_LNS_set_basic_block: {
 | |
|       lsm->basic_block = true;
 | |
|     }
 | |
|       break;
 | |
|     case DW_LNS_fixed_advance_pc: {
 | |
|       const uint16 advance_address = reader->ReadTwoBytes(start);
 | |
|       oplen += 2;
 | |
| 
 | |
|       // Check if the lsm passes "pc". If so, mark it as passed.
 | |
|       if (lsm_passes_pc &&
 | |
|           lsm->address <= pc && pc < lsm->address + advance_address) {
 | |
|         *lsm_passes_pc = true;
 | |
|       }
 | |
| 
 | |
|       lsm->address += advance_address;
 | |
|     }
 | |
|       break;
 | |
|     case DW_LNS_const_add_pc: {
 | |
|       const int64 advance_address = header.min_insn_length
 | |
|                                     * ((255 - header.opcode_base)
 | |
|                                        / header.line_range);
 | |
| 
 | |
|       // Check if the lsm passes "pc". If so, mark it as passed.
 | |
|       if (lsm_passes_pc &&
 | |
|           lsm->address <= pc && pc < lsm->address + advance_address) {
 | |
|         *lsm_passes_pc = true;
 | |
|       }
 | |
| 
 | |
|       lsm->address += advance_address;
 | |
|     }
 | |
|       break;
 | |
|     case DW_LNS_extended_op: {
 | |
|       const uint64 extended_op_len = reader->ReadUnsignedLEB128(start,
 | |
|                                                                 &templen);
 | |
|       start += templen;
 | |
|       oplen += templen + extended_op_len;
 | |
| 
 | |
|       const uint64 extended_op = reader->ReadOneByte(start);
 | |
|       start++;
 | |
| 
 | |
|       switch (extended_op) {
 | |
|         case DW_LNE_end_sequence: {
 | |
|           lsm->end_sequence = true;
 | |
|           *len = oplen;
 | |
|           return true;
 | |
|         }
 | |
|           break;
 | |
|         case DW_LNE_set_address: {
 | |
|           // With gcc 4.2.1, we cannot tell the line_no here since
 | |
|           // DW_LNE_set_address is called before DW_LNS_advance_line is
 | |
|           // called.  So we do not check if the lsm passes "pc" here.  See
 | |
|           // also the comment in DW_LNS_advance_line.
 | |
|           uint64 address = reader->ReadAddress(start);
 | |
|           lsm->address = address;
 | |
|         }
 | |
|           break;
 | |
|         case DW_LNE_define_file: {
 | |
|           const char* filename  = start;
 | |
| 
 | |
|           templen = strlen(filename) + 1;
 | |
|           start += templen;
 | |
| 
 | |
|           uint64 dirindex = reader->ReadUnsignedLEB128(start, &templen);
 | |
|           oplen += templen;
 | |
| 
 | |
|           const uint64 mod_time = reader->ReadUnsignedLEB128(start,
 | |
|                                                              &templen);
 | |
|           oplen += templen;
 | |
| 
 | |
|           const uint64 filelength = reader->ReadUnsignedLEB128(start,
 | |
|                                                                &templen);
 | |
|           oplen += templen;
 | |
| 
 | |
|           if (handler) {
 | |
|             handler->DefineFile(filename, -1, static_cast<uint32>(dirindex), 
 | |
|                                 mod_time, filelength);
 | |
|           }
 | |
|         }
 | |
|           break;
 | |
|       }
 | |
|     }
 | |
|       break;
 | |
| 
 | |
|     default: {
 | |
|       // Ignore unknown opcode  silently
 | |
|       if (header.std_opcode_lengths) {
 | |
|         for (int i = 0; i < (*header.std_opcode_lengths)[opcode]; i++) {
 | |
|           reader->ReadUnsignedLEB128(start, &templen);
 | |
|           start += templen;
 | |
|           oplen += templen;
 | |
|         }
 | |
|       }
 | |
|     }
 | |
|       break;
 | |
|   }
 | |
|   *len = oplen;
 | |
|   return false;
 | |
| }
 | |
| 
 | |
| void LineInfo::ReadLines() {
 | |
|   struct LineStateMachine lsm;
 | |
| 
 | |
|   // lengthstart is the place the length field is based on.
 | |
|   // It is the point in the header after the initial length field
 | |
|   const char* lengthstart = buffer_;
 | |
| 
 | |
|   // In 64 bit dwarf, the initial length is 12 bytes, because of the
 | |
|   // 0xffffffff at the start.
 | |
|   if (reader_->OffsetSize() == 8)
 | |
|     lengthstart += 12;
 | |
|   else
 | |
|     lengthstart += 4;
 | |
| 
 | |
|   const char* lineptr = after_header_;
 | |
|   lsm.Reset(header_.default_is_stmt);
 | |
| 
 | |
|   // The LineInfoHandler interface expects each line's length along
 | |
|   // with its address, but DWARF only provides addresses (sans
 | |
|   // length), and an end-of-sequence address; one infers the length
 | |
|   // from the next address. So we report a line only when we get the
 | |
|   // next line's address, or the end-of-sequence address.
 | |
|   bool have_pending_line = false;
 | |
|   uint64 pending_address = 0;
 | |
|   uint32 pending_file_num = 0, pending_line_num = 0, pending_column_num = 0;
 | |
| 
 | |
|   while (lineptr < lengthstart + header_.total_length) {
 | |
|     size_t oplength;
 | |
|     bool add_row = ProcessOneOpcode(reader_, handler_, header_,
 | |
|                                     lineptr, &lsm, &oplength, (uintptr)-1,
 | |
|                                     NULL);
 | |
|     if (add_row) {
 | |
|       if (have_pending_line)
 | |
|         handler_->AddLine(pending_address, lsm.address - pending_address,
 | |
|                           pending_file_num, pending_line_num,
 | |
|                           pending_column_num);
 | |
|       if (lsm.end_sequence) {
 | |
|         lsm.Reset(header_.default_is_stmt);      
 | |
|         have_pending_line = false;
 | |
|       } else {
 | |
|         pending_address = lsm.address;
 | |
|         pending_file_num = lsm.file_num;
 | |
|         pending_line_num = lsm.line_num;
 | |
|         pending_column_num = lsm.column_num;
 | |
|         have_pending_line = true;
 | |
|       }
 | |
|     }
 | |
|     lineptr += oplength;
 | |
|   }
 | |
| 
 | |
|   after_header_ = lengthstart + header_.total_length;
 | |
| }
 | |
| 
 | |
| // A DWARF rule for recovering the address or value of a register, or
 | |
| // computing the canonical frame address. There is one subclass of this for
 | |
| // each '*Rule' member function in CallFrameInfo::Handler.
 | |
| //
 | |
| // It's annoying that we have to handle Rules using pointers (because
 | |
| // the concrete instances can have an arbitrary size). They're small,
 | |
| // so it would be much nicer if we could just handle them by value
 | |
| // instead of fretting about ownership and destruction.
 | |
| //
 | |
| // It seems like all these could simply be instances of std::tr1::bind,
 | |
| // except that we need instances to be EqualityComparable, too.
 | |
| //
 | |
| // This could logically be nested within State, but then the qualified names
 | |
| // get horrendous.
 | |
| class CallFrameInfo::Rule {
 | |
|  public:
 | |
|   virtual ~Rule() { }
 | |
| 
 | |
|   // Tell HANDLER that, at ADDRESS in the program, REGISTER can be
 | |
|   // recovered using this rule. If REGISTER is kCFARegister, then this rule
 | |
|   // describes how to compute the canonical frame address. Return what the
 | |
|   // HANDLER member function returned.
 | |
|   virtual bool Handle(Handler *handler,
 | |
|                       uint64 address, int register) const = 0;
 | |
| 
 | |
|   // Equality on rules. We use these to decide which rules we need
 | |
|   // to report after a DW_CFA_restore_state instruction.
 | |
|   virtual bool operator==(const Rule &rhs) const = 0;
 | |
| 
 | |
|   bool operator!=(const Rule &rhs) const { return ! (*this == rhs); }
 | |
| 
 | |
|   // Return a pointer to a copy of this rule.
 | |
|   virtual Rule *Copy() const = 0;
 | |
| 
 | |
|   // If this is a base+offset rule, change its base register to REG.
 | |
|   // Otherwise, do nothing. (Ugly, but required for DW_CFA_def_cfa_register.)
 | |
|   virtual void SetBaseRegister(unsigned reg) { }
 | |
| 
 | |
|   // If this is a base+offset rule, change its offset to OFFSET. Otherwise,
 | |
|   // do nothing. (Ugly, but required for DW_CFA_def_cfa_offset.)
 | |
|   virtual void SetOffset(long long offset) { }
 | |
| };
 | |
| 
 | |
| // Rule: the value the register had in the caller cannot be recovered.
 | |
| class CallFrameInfo::UndefinedRule: public CallFrameInfo::Rule {
 | |
|  public:
 | |
|   UndefinedRule() { }
 | |
|   ~UndefinedRule() { }
 | |
|   bool Handle(Handler *handler, uint64 address, int reg) const {
 | |
|     return handler->UndefinedRule(address, reg);
 | |
|   }
 | |
|   bool operator==(const Rule &rhs) const {
 | |
|     // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
 | |
|     // been carefully considered; cheap RTTI-like workarounds are forbidden.
 | |
|     const UndefinedRule *our_rhs = dynamic_cast<const UndefinedRule *>(&rhs);
 | |
|     return (our_rhs != NULL);
 | |
|   }
 | |
|   Rule *Copy() const { return new UndefinedRule(*this); }
 | |
| };
 | |
| 
 | |
| // Rule: the register's value is the same as that it had in the caller.
 | |
| class CallFrameInfo::SameValueRule: public CallFrameInfo::Rule {
 | |
|  public:
 | |
|   SameValueRule() { }
 | |
|   ~SameValueRule() { }
 | |
|   bool Handle(Handler *handler, uint64 address, int reg) const {
 | |
|     return handler->SameValueRule(address, reg);
 | |
|   }
 | |
|   bool operator==(const Rule &rhs) const {
 | |
|     // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
 | |
|     // been carefully considered; cheap RTTI-like workarounds are forbidden.
 | |
|     const SameValueRule *our_rhs = dynamic_cast<const SameValueRule *>(&rhs);
 | |
|     return (our_rhs != NULL);
 | |
|   }
 | |
|   Rule *Copy() const { return new SameValueRule(*this); }
 | |
| };
 | |
| 
 | |
| // Rule: the register is saved at OFFSET from BASE_REGISTER.  BASE_REGISTER
 | |
| // may be CallFrameInfo::Handler::kCFARegister.
 | |
| class CallFrameInfo::OffsetRule: public CallFrameInfo::Rule {
 | |
|  public:
 | |
|   OffsetRule(int base_register, long offset)
 | |
|       : base_register_(base_register), offset_(offset) { }
 | |
|   ~OffsetRule() { }
 | |
|   bool Handle(Handler *handler, uint64 address, int reg) const {
 | |
|     return handler->OffsetRule(address, reg, base_register_, offset_);
 | |
|   }
 | |
|   bool operator==(const Rule &rhs) const {
 | |
|     // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
 | |
|     // been carefully considered; cheap RTTI-like workarounds are forbidden.
 | |
|     const OffsetRule *our_rhs = dynamic_cast<const OffsetRule *>(&rhs);
 | |
|     return (our_rhs &&
 | |
|             base_register_ == our_rhs->base_register_ &&
 | |
|             offset_ == our_rhs->offset_);
 | |
|   }
 | |
|   Rule *Copy() const { return new OffsetRule(*this); }
 | |
|   // We don't actually need SetBaseRegister or SetOffset here, since they
 | |
|   // are only ever applied to CFA rules, for DW_CFA_def_cfa_offset, and it
 | |
|   // doesn't make sense to use OffsetRule for computing the CFA: it
 | |
|   // computes the address at which a register is saved, not a value.
 | |
|  private:
 | |
|   int base_register_;
 | |
|   long offset_;
 | |
| };
 | |
| 
 | |
| // Rule: the value the register had in the caller is the value of
 | |
| // BASE_REGISTER plus offset. BASE_REGISTER may be
 | |
| // CallFrameInfo::Handler::kCFARegister.
 | |
| class CallFrameInfo::ValOffsetRule: public CallFrameInfo::Rule {
 | |
|  public:
 | |
|   ValOffsetRule(int base_register, long offset)
 | |
|       : base_register_(base_register), offset_(offset) { }
 | |
|   ~ValOffsetRule() { }
 | |
|   bool Handle(Handler *handler, uint64 address, int reg) const {
 | |
|     return handler->ValOffsetRule(address, reg, base_register_, offset_);
 | |
|   }
 | |
|   bool operator==(const Rule &rhs) const {
 | |
|     // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
 | |
|     // been carefully considered; cheap RTTI-like workarounds are forbidden.
 | |
|     const ValOffsetRule *our_rhs = dynamic_cast<const ValOffsetRule *>(&rhs);
 | |
|     return (our_rhs &&
 | |
|             base_register_ == our_rhs->base_register_ &&
 | |
|             offset_ == our_rhs->offset_);
 | |
|   }
 | |
|   Rule *Copy() const { return new ValOffsetRule(*this); }
 | |
|   void SetBaseRegister(unsigned reg) { base_register_ = reg; }
 | |
|   void SetOffset(long long offset) { offset_ = offset; }
 | |
|  private:
 | |
|   int base_register_;
 | |
|   long offset_;
 | |
| };
 | |
| 
 | |
| // Rule: the register has been saved in another register REGISTER_NUMBER_.
 | |
| class CallFrameInfo::RegisterRule: public CallFrameInfo::Rule {
 | |
|  public:
 | |
|   explicit RegisterRule(int register_number)
 | |
|       : register_number_(register_number) { }
 | |
|   ~RegisterRule() { }
 | |
|   bool Handle(Handler *handler, uint64 address, int reg) const {
 | |
|     return handler->RegisterRule(address, reg, register_number_);
 | |
|   }
 | |
|   bool operator==(const Rule &rhs) const {
 | |
|     // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
 | |
|     // been carefully considered; cheap RTTI-like workarounds are forbidden.
 | |
|     const RegisterRule *our_rhs = dynamic_cast<const RegisterRule *>(&rhs);
 | |
|     return (our_rhs && register_number_ == our_rhs->register_number_);
 | |
|   }
 | |
|   Rule *Copy() const { return new RegisterRule(*this); }
 | |
|  private:
 | |
|   int register_number_;
 | |
| };
 | |
| 
 | |
| // Rule: EXPRESSION evaluates to the address at which the register is saved.
 | |
| class CallFrameInfo::ExpressionRule: public CallFrameInfo::Rule {
 | |
|  public:
 | |
|   explicit ExpressionRule(const string &expression)
 | |
|       : expression_(expression) { }
 | |
|   ~ExpressionRule() { }
 | |
|   bool Handle(Handler *handler, uint64 address, int reg) const {
 | |
|     return handler->ExpressionRule(address, reg, expression_);
 | |
|   }
 | |
|   bool operator==(const Rule &rhs) const {
 | |
|     // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
 | |
|     // been carefully considered; cheap RTTI-like workarounds are forbidden.
 | |
|     const ExpressionRule *our_rhs = dynamic_cast<const ExpressionRule *>(&rhs);
 | |
|     return (our_rhs && expression_ == our_rhs->expression_);
 | |
|   }
 | |
|   Rule *Copy() const { return new ExpressionRule(*this); }
 | |
|  private:
 | |
|   string expression_;
 | |
| };
 | |
| 
 | |
| // Rule: EXPRESSION evaluates to the address at which the register is saved.
 | |
| class CallFrameInfo::ValExpressionRule: public CallFrameInfo::Rule {
 | |
|  public:
 | |
|   explicit ValExpressionRule(const string &expression)
 | |
|       : expression_(expression) { }
 | |
|   ~ValExpressionRule() { }
 | |
|   bool Handle(Handler *handler, uint64 address, int reg) const {
 | |
|     return handler->ValExpressionRule(address, reg, expression_);
 | |
|   }
 | |
|   bool operator==(const Rule &rhs) const {
 | |
|     // dynamic_cast is allowed by the Google C++ Style Guide, if the use has
 | |
|     // been carefully considered; cheap RTTI-like workarounds are forbidden.
 | |
|     const ValExpressionRule *our_rhs =
 | |
|         dynamic_cast<const ValExpressionRule *>(&rhs);
 | |
|     return (our_rhs && expression_ == our_rhs->expression_);
 | |
|   }
 | |
|   Rule *Copy() const { return new ValExpressionRule(*this); }
 | |
|  private:
 | |
|   string expression_;
 | |
| };
 | |
| 
 | |
| // A map from register numbers to rules.
 | |
| class CallFrameInfo::RuleMap {
 | |
|  public:
 | |
|   RuleMap() : cfa_rule_(NULL) { }
 | |
|   RuleMap(const RuleMap &rhs) : cfa_rule_(NULL) { *this = rhs; }
 | |
|   ~RuleMap() { Clear(); }
 | |
| 
 | |
|   RuleMap &operator=(const RuleMap &rhs);
 | |
| 
 | |
|   // Set the rule for computing the CFA to RULE. Take ownership of RULE.
 | |
|   void SetCFARule(Rule *rule) { delete cfa_rule_; cfa_rule_ = rule; }
 | |
| 
 | |
|   // Return the current CFA rule. Unlike RegisterRule, this RuleMap retains
 | |
|   // ownership of the rule. We use this for DW_CFA_def_cfa_offset and
 | |
|   // DW_CFA_def_cfa_register, and for detecting references to the CFA before
 | |
|   // a rule for it has been established.
 | |
|   Rule *CFARule() const { return cfa_rule_; }
 | |
| 
 | |
|   // Return the rule for REG, or NULL if there is none. The caller takes
 | |
|   // ownership of the result.
 | |
|   Rule *RegisterRule(int reg) const;
 | |
| 
 | |
|   // Set the rule for computing REG to RULE. Take ownership of RULE.
 | |
|   void SetRegisterRule(int reg, Rule *rule);
 | |
| 
 | |
|   // Make all the appropriate calls to HANDLER as if we were changing from
 | |
|   // this RuleMap to NEW_RULES at ADDRESS. We use this to implement
 | |
|   // DW_CFA_restore_state, where lots of rules can change simultaneously.
 | |
|   // Return true if all handlers returned true; otherwise, return false.
 | |
|   bool HandleTransitionTo(Handler *handler, uint64 address,
 | |
|                           const RuleMap &new_rules) const;
 | |
| 
 | |
|  private:
 | |
|   // A map from register numbers to Rules.
 | |
|   typedef std::map<int, Rule *> RuleByNumber;
 | |
| 
 | |
|   // Remove all register rules and clear cfa_rule_.
 | |
|   void Clear();
 | |
| 
 | |
|   // The rule for computing the canonical frame address. This RuleMap owns
 | |
|   // this rule.
 | |
|   Rule *cfa_rule_;
 | |
| 
 | |
|   // A map from register numbers to postfix expressions to recover
 | |
|   // their values. This RuleMap owns the Rules the map refers to.
 | |
|   RuleByNumber registers_;
 | |
| };
 | |
| 
 | |
| CallFrameInfo::RuleMap &CallFrameInfo::RuleMap::operator=(const RuleMap &rhs) {
 | |
|   Clear();
 | |
|   // Since each map owns the rules it refers to, assignment must copy them.
 | |
|   if (rhs.cfa_rule_) cfa_rule_ = rhs.cfa_rule_->Copy();
 | |
|   for (RuleByNumber::const_iterator it = rhs.registers_.begin();
 | |
|        it != rhs.registers_.end(); it++)
 | |
|     registers_[it->first] = it->second->Copy();
 | |
|   return *this;
 | |
| }
 | |
| 
 | |
| CallFrameInfo::Rule *CallFrameInfo::RuleMap::RegisterRule(int reg) const {
 | |
|   assert(reg != Handler::kCFARegister);
 | |
|   RuleByNumber::const_iterator it = registers_.find(reg);
 | |
|   if (it != registers_.end())
 | |
|     return it->second->Copy();
 | |
|   else
 | |
|     return NULL;
 | |
| }
 | |
| 
 | |
| void CallFrameInfo::RuleMap::SetRegisterRule(int reg, Rule *rule) {
 | |
|   assert(reg != Handler::kCFARegister);
 | |
|   assert(rule);
 | |
|   Rule **slot = ®isters_[reg];
 | |
|   delete *slot;
 | |
|   *slot = rule;
 | |
| }
 | |
| 
 | |
| bool CallFrameInfo::RuleMap::HandleTransitionTo(
 | |
|     Handler *handler,
 | |
|     uint64 address,
 | |
|     const RuleMap &new_rules) const {
 | |
|   // Transition from cfa_rule_ to new_rules.cfa_rule_.
 | |
|   if (cfa_rule_ && new_rules.cfa_rule_) {
 | |
|     if (*cfa_rule_ != *new_rules.cfa_rule_ &&
 | |
|         !new_rules.cfa_rule_->Handle(handler, address,
 | |
|                                      Handler::kCFARegister))
 | |
|       return false;
 | |
|   } else if (cfa_rule_) {
 | |
|     // this RuleMap has a CFA rule but new_rules doesn't.
 | |
|     // CallFrameInfo::Handler has no way to handle this --- and shouldn't;
 | |
|     // it's garbage input. The instruction interpreter should have
 | |
|     // detected this and warned, so take no action here.
 | |
|   } else if (new_rules.cfa_rule_) {
 | |
|     // This shouldn't be possible: NEW_RULES is some prior state, and
 | |
|     // there's no way to remove entries.
 | |
|     assert(0);
 | |
|   } else {
 | |
|     // Both CFA rules are empty.  No action needed.
 | |
|   }
 | |
| 
 | |
|   // Traverse the two maps in order by register number, and report
 | |
|   // whatever differences we find.
 | |
|   RuleByNumber::const_iterator old_it = registers_.begin();
 | |
|   RuleByNumber::const_iterator new_it = new_rules.registers_.begin();
 | |
|   while (old_it != registers_.end() && new_it != new_rules.registers_.end()) {
 | |
|     if (old_it->first < new_it->first) {
 | |
|       // This RuleMap has an entry for old_it->first, but NEW_RULES
 | |
|       // doesn't.
 | |
|       //
 | |
|       // This isn't really the right thing to do, but since CFI generally
 | |
|       // only mentions callee-saves registers, and GCC's convention for
 | |
|       // callee-saves registers is that they are unchanged, it's a good
 | |
|       // approximation.
 | |
|       if (!handler->SameValueRule(address, old_it->first))
 | |
|         return false;
 | |
|       old_it++;
 | |
|     } else if (old_it->first > new_it->first) {
 | |
|       // NEW_RULES has entry for new_it->first, but this RuleMap
 | |
|       // doesn't. This shouldn't be possible: NEW_RULES is some prior
 | |
|       // state, and there's no way to remove entries.
 | |
|       assert(0);
 | |
|     } else {
 | |
|       // Both maps have an entry for this register. Report the new
 | |
|       // rule if it is different.
 | |
|       if (*old_it->second != *new_it->second &&
 | |
|           !new_it->second->Handle(handler, address, new_it->first))
 | |
|         return false;
 | |
|       new_it++, old_it++;
 | |
|     }
 | |
|   }
 | |
|   // Finish off entries from this RuleMap with no counterparts in new_rules.
 | |
|   while (old_it != registers_.end()) {
 | |
|     if (!handler->SameValueRule(address, old_it->first))
 | |
|       return false;
 | |
|     old_it++;
 | |
|   }
 | |
|   // Since we only make transitions from a rule set to some previously
 | |
|   // saved rule set, and we can only add rules to the map, NEW_RULES
 | |
|   // must have fewer rules than *this.
 | |
|   assert(new_it == new_rules.registers_.end());
 | |
| 
 | |
|   return true;
 | |
| }
 | |
| 
 | |
| // Remove all register rules and clear cfa_rule_.
 | |
| void CallFrameInfo::RuleMap::Clear() {
 | |
|   delete cfa_rule_;
 | |
|   cfa_rule_ = NULL;
 | |
|   for (RuleByNumber::iterator it = registers_.begin();
 | |
|        it != registers_.end(); it++)
 | |
|     delete it->second;
 | |
|   registers_.clear();
 | |
| }
 | |
| 
 | |
| // The state of the call frame information interpreter as it processes
 | |
| // instructions from a CIE and FDE.
 | |
| class CallFrameInfo::State {
 | |
|  public:
 | |
|   // Create a call frame information interpreter state with the given
 | |
|   // reporter, reader, handler, and initial call frame info address.
 | |
|   State(ByteReader *reader, Handler *handler, Reporter *reporter,
 | |
|         uint64 address)
 | |
|       : reader_(reader), handler_(handler), reporter_(reporter),
 | |
|         address_(address), entry_(NULL), cursor_(NULL) { }
 | |
| 
 | |
|   // Interpret instructions from CIE, save the resulting rule set for
 | |
|   // DW_CFA_restore instructions, and return true. On error, report
 | |
|   // the problem to reporter_ and return false.
 | |
|   bool InterpretCIE(const CIE &cie);
 | |
| 
 | |
|   // Interpret instructions from FDE, and return true. On error,
 | |
|   // report the problem to reporter_ and return false.
 | |
|   bool InterpretFDE(const FDE &fde);
 | |
| 
 | |
|  private:  
 | |
|   // The operands of a CFI instruction, for ParseOperands.
 | |
|   struct Operands {
 | |
|     unsigned register_number;  // A register number.
 | |
|     uint64 offset;             // An offset or address.
 | |
|     long signed_offset;        // A signed offset.
 | |
|     string expression;         // A DWARF expression.
 | |
|   };
 | |
| 
 | |
|   // Parse CFI instruction operands from STATE's instruction stream as
 | |
|   // described by FORMAT. On success, populate OPERANDS with the
 | |
|   // results, and return true. On failure, report the problem and
 | |
|   // return false.
 | |
|   //
 | |
|   // Each character of FORMAT should be one of the following:
 | |
|   //
 | |
|   //   'r'  unsigned LEB128 register number (OPERANDS->register_number)
 | |
|   //   'o'  unsigned LEB128 offset          (OPERANDS->offset)
 | |
|   //   's'  signed LEB128 offset            (OPERANDS->signed_offset)
 | |
|   //   'a'  machine-size address            (OPERANDS->offset)
 | |
|   //        (If the CIE has a 'z' augmentation string, 'a' uses the
 | |
|   //        encoding specified by the 'R' argument.)
 | |
|   //   '1'  a one-byte offset               (OPERANDS->offset)
 | |
|   //   '2'  a two-byte offset               (OPERANDS->offset)
 | |
|   //   '4'  a four-byte offset              (OPERANDS->offset)
 | |
|   //   '8'  an eight-byte offset            (OPERANDS->offset)
 | |
|   //   'e'  a DW_FORM_block holding a       (OPERANDS->expression)
 | |
|   //        DWARF expression
 | |
|   bool ParseOperands(const char *format, Operands *operands);
 | |
| 
 | |
|   // Interpret one CFI instruction from STATE's instruction stream, update
 | |
|   // STATE, report any rule changes to handler_, and return true. On
 | |
|   // failure, report the problem and return false.
 | |
|   bool DoInstruction();
 | |
| 
 | |
|   // The following Do* member functions are subroutines of DoInstruction,
 | |
|   // factoring out the actual work of operations that have several
 | |
|   // different encodings.
 | |
| 
 | |
|   // Set the CFA rule to be the value of BASE_REGISTER plus OFFSET, and
 | |
|   // return true. On failure, report and return false. (Used for
 | |
|   // DW_CFA_def_cfa and DW_CFA_def_cfa_sf.)
 | |
|   bool DoDefCFA(unsigned base_register, long offset);
 | |
| 
 | |
|   // Change the offset of the CFA rule to OFFSET, and return true. On
 | |
|   // failure, report and return false. (Subroutine for
 | |
|   // DW_CFA_def_cfa_offset and DW_CFA_def_cfa_offset_sf.)
 | |
|   bool DoDefCFAOffset(long offset);
 | |
| 
 | |
|   // Specify that REG can be recovered using RULE, and return true. On
 | |
|   // failure, report and return false.
 | |
|   bool DoRule(unsigned reg, Rule *rule);
 | |
| 
 | |
|   // Specify that REG can be found at OFFSET from the CFA, and return true.
 | |
|   // On failure, report and return false. (Subroutine for DW_CFA_offset,
 | |
|   // DW_CFA_offset_extended, and DW_CFA_offset_extended_sf.)
 | |
|   bool DoOffset(unsigned reg, long offset);
 | |
| 
 | |
|   // Specify that the caller's value for REG is the CFA plus OFFSET,
 | |
|   // and return true. On failure, report and return false. (Subroutine
 | |
|   // for DW_CFA_val_offset and DW_CFA_val_offset_sf.)
 | |
|   bool DoValOffset(unsigned reg, long offset);
 | |
| 
 | |
|   // Restore REG to the rule established in the CIE, and return true. On
 | |
|   // failure, report and return false. (Subroutine for DW_CFA_restore and
 | |
|   // DW_CFA_restore_extended.)
 | |
|   bool DoRestore(unsigned reg);
 | |
| 
 | |
|   // Return the section offset of the instruction at cursor. For use
 | |
|   // in error messages.
 | |
|   uint64 CursorOffset() { return entry_->offset + (cursor_ - entry_->start); }
 | |
| 
 | |
|   // Report that entry_ is incomplete, and return false. For brevity.
 | |
|   bool ReportIncomplete() {
 | |
|     reporter_->Incomplete(entry_->offset, entry_->kind);
 | |
|     return false;
 | |
|   }
 | |
| 
 | |
|   // For reading multi-byte values with the appropriate endianness.
 | |
|   ByteReader *reader_;
 | |
| 
 | |
|   // The handler to which we should report the data we find.
 | |
|   Handler *handler_;
 | |
| 
 | |
|   // For reporting problems in the info we're parsing.
 | |
|   Reporter *reporter_;
 | |
| 
 | |
|   // The code address to which the next instruction in the stream applies.
 | |
|   uint64 address_;
 | |
| 
 | |
|   // The entry whose instructions we are currently processing. This is
 | |
|   // first a CIE, and then an FDE.
 | |
|   const Entry *entry_;
 | |
| 
 | |
|   // The next instruction to process.
 | |
|   const char *cursor_;
 | |
| 
 | |
|   // The current set of rules.
 | |
|   RuleMap rules_;
 | |
| 
 | |
|   // The set of rules established by the CIE, used by DW_CFA_restore
 | |
|   // and DW_CFA_restore_extended. We set this after interpreting the
 | |
|   // CIE's instructions.
 | |
|   RuleMap cie_rules_;
 | |
| 
 | |
|   // A stack of saved states, for DW_CFA_remember_state and
 | |
|   // DW_CFA_restore_state.
 | |
|   std::stack<RuleMap> saved_rules_;
 | |
| };
 | |
| 
 | |
| bool CallFrameInfo::State::InterpretCIE(const CIE &cie) {
 | |
|   entry_ = &cie;
 | |
|   cursor_ = entry_->instructions;
 | |
|   while (cursor_ < entry_->end)
 | |
|     if (!DoInstruction())
 | |
|       return false;
 | |
|   // Note the rules established by the CIE, for use by DW_CFA_restore
 | |
|   // and DW_CFA_restore_extended.
 | |
|   cie_rules_ = rules_;
 | |
|   return true;
 | |
| }
 | |
| 
 | |
| bool CallFrameInfo::State::InterpretFDE(const FDE &fde) {
 | |
|   entry_ = &fde;
 | |
|   cursor_ = entry_->instructions;
 | |
|   while (cursor_ < entry_->end)
 | |
|     if (!DoInstruction())
 | |
|       return false;
 | |
|   return true;
 | |
| }
 | |
| 
 | |
| bool CallFrameInfo::State::ParseOperands(const char *format,
 | |
|                                          Operands *operands) {
 | |
|   size_t len;
 | |
|   const char *operand;
 | |
| 
 | |
|   for (operand = format; *operand; operand++) {
 | |
|     size_t bytes_left = entry_->end - cursor_;
 | |
|     switch (*operand) {
 | |
|       case 'r':
 | |
|         operands->register_number = reader_->ReadUnsignedLEB128(cursor_, &len);
 | |
|         if (len > bytes_left) return ReportIncomplete();
 | |
|         cursor_ += len;
 | |
|         break;
 | |
| 
 | |
|       case 'o':
 | |
|         operands->offset = reader_->ReadUnsignedLEB128(cursor_, &len);
 | |
|         if (len > bytes_left) return ReportIncomplete();
 | |
|         cursor_ += len;
 | |
|         break;
 | |
| 
 | |
|       case 's':
 | |
|         operands->signed_offset = reader_->ReadSignedLEB128(cursor_, &len);
 | |
|         if (len > bytes_left) return ReportIncomplete();
 | |
|         cursor_ += len;
 | |
|         break;
 | |
| 
 | |
|       case 'a':
 | |
|         operands->offset =
 | |
|           reader_->ReadEncodedPointer(cursor_, entry_->cie->pointer_encoding,
 | |
|                                       &len);
 | |
|         if (len > bytes_left) return ReportIncomplete();
 | |
|         cursor_ += len;
 | |
|         break;
 | |
| 
 | |
|       case '1':
 | |
|         if (1 > bytes_left) return ReportIncomplete();
 | |
|         operands->offset = static_cast<unsigned char>(*cursor_++);
 | |
|         break;
 | |
| 
 | |
|       case '2':
 | |
|         if (2 > bytes_left) return ReportIncomplete();
 | |
|         operands->offset = reader_->ReadTwoBytes(cursor_);
 | |
|         cursor_ += 2;
 | |
|         break;
 | |
| 
 | |
|       case '4':
 | |
|         if (4 > bytes_left) return ReportIncomplete();
 | |
|         operands->offset = reader_->ReadFourBytes(cursor_);
 | |
|         cursor_ += 4;
 | |
|         break;
 | |
| 
 | |
|       case '8':
 | |
|         if (8 > bytes_left) return ReportIncomplete();
 | |
|         operands->offset = reader_->ReadEightBytes(cursor_);
 | |
|         cursor_ += 8;
 | |
|         break;
 | |
| 
 | |
|       case 'e': {
 | |
|         size_t expression_length = reader_->ReadUnsignedLEB128(cursor_, &len);
 | |
|         if (len > bytes_left || expression_length > bytes_left - len)
 | |
|           return ReportIncomplete();
 | |
|         cursor_ += len;
 | |
|         operands->expression = string(cursor_, expression_length);
 | |
|         cursor_ += expression_length;
 | |
|         break;
 | |
|       }
 | |
| 
 | |
|       default:
 | |
|           assert(0);
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   return true;
 | |
| }
 | |
| 
 | |
| bool CallFrameInfo::State::DoInstruction() {
 | |
|   CIE *cie = entry_->cie;
 | |
|   Operands ops;
 | |
| 
 | |
|   // Our entry's kind should have been set by now.
 | |
|   assert(entry_->kind != kUnknown);
 | |
| 
 | |
|   // We shouldn't have been invoked unless there were more
 | |
|   // instructions to parse.
 | |
|   assert(cursor_ < entry_->end);
 | |
| 
 | |
|   unsigned opcode = *cursor_++;
 | |
|   if ((opcode & 0xc0) != 0) {
 | |
|     switch (opcode & 0xc0) {
 | |
|       // Advance the address.
 | |
|       case DW_CFA_advance_loc: {
 | |
|         size_t code_offset = opcode & 0x3f;
 | |
|         address_ += code_offset * cie->code_alignment_factor;
 | |
|         break;
 | |
|       }
 | |
| 
 | |
|       // Find a register at an offset from the CFA.
 | |
|       case DW_CFA_offset:
 | |
|         if (!ParseOperands("o", &ops) ||
 | |
|             !DoOffset(opcode & 0x3f, ops.offset * cie->data_alignment_factor))
 | |
|           return false;
 | |
|         break;
 | |
| 
 | |
|       // Restore the rule established for a register by the CIE.
 | |
|       case DW_CFA_restore:
 | |
|         if (!DoRestore(opcode & 0x3f)) return false;
 | |
|         break;
 | |
| 
 | |
|       // The 'if' above should have excluded this possibility.
 | |
|       default:
 | |
|         assert(0);
 | |
|     }
 | |
| 
 | |
|     // Return here, so the big switch below won't be indented.
 | |
|     return true;
 | |
|   }
 | |
| 
 | |
|   switch (opcode) {
 | |
|     // Set the address.
 | |
|     case DW_CFA_set_loc:
 | |
|       if (!ParseOperands("a", &ops)) return false;
 | |
|       address_ = ops.offset;
 | |
|       break;
 | |
| 
 | |
|     // Advance the address.
 | |
|     case DW_CFA_advance_loc1:
 | |
|       if (!ParseOperands("1", &ops)) return false;
 | |
|       address_ += ops.offset * cie->code_alignment_factor;
 | |
|       break;
 | |
|       
 | |
|     // Advance the address.
 | |
|     case DW_CFA_advance_loc2:
 | |
|       if (!ParseOperands("2", &ops)) return false;
 | |
|       address_ += ops.offset * cie->code_alignment_factor;
 | |
|       break;
 | |
|       
 | |
|     // Advance the address.
 | |
|     case DW_CFA_advance_loc4:
 | |
|       if (!ParseOperands("4", &ops)) return false;
 | |
|       address_ += ops.offset * cie->code_alignment_factor;
 | |
|       break;
 | |
|       
 | |
|     // Advance the address.
 | |
|     case DW_CFA_MIPS_advance_loc8:
 | |
|       if (!ParseOperands("8", &ops)) return false;
 | |
|       address_ += ops.offset * cie->code_alignment_factor;
 | |
|       break;
 | |
| 
 | |
|     // Compute the CFA by adding an offset to a register.
 | |
|     case DW_CFA_def_cfa:
 | |
|       if (!ParseOperands("ro", &ops) ||
 | |
|           !DoDefCFA(ops.register_number, ops.offset))
 | |
|         return false;
 | |
|       break;
 | |
| 
 | |
|     // Compute the CFA by adding an offset to a register.
 | |
|     case DW_CFA_def_cfa_sf:
 | |
|       if (!ParseOperands("rs", &ops) ||
 | |
|           !DoDefCFA(ops.register_number,
 | |
|                     ops.signed_offset * cie->data_alignment_factor))
 | |
|         return false;
 | |
|       break;
 | |
| 
 | |
|     // Change the base register used to compute the CFA.
 | |
|     case DW_CFA_def_cfa_register: {
 | |
|       if (!ParseOperands("r", &ops)) return false;
 | |
|       Rule *cfa_rule = rules_.CFARule();
 | |
|       if (!cfa_rule) {
 | |
|         if (!DoDefCFA(ops.register_number, ops.offset)) {
 | |
|           reporter_->NoCFARule(entry_->offset, entry_->kind, CursorOffset());
 | |
|           return false;
 | |
|         }
 | |
|       } else {
 | |
|         cfa_rule->SetBaseRegister(ops.register_number);
 | |
|         if (!cfa_rule->Handle(handler_, address_,
 | |
|                               Handler::kCFARegister))
 | |
|         return false;
 | |
|       }
 | |
|       break;
 | |
|     }
 | |
| 
 | |
|     // Change the offset used to compute the CFA.
 | |
|     case DW_CFA_def_cfa_offset:
 | |
|       if (!ParseOperands("o", &ops) ||
 | |
|           !DoDefCFAOffset(ops.offset))
 | |
|         return false;
 | |
|       break;
 | |
| 
 | |
|     // Change the offset used to compute the CFA.
 | |
|     case DW_CFA_def_cfa_offset_sf:
 | |
|       if (!ParseOperands("s", &ops) ||
 | |
|           !DoDefCFAOffset(ops.signed_offset * cie->data_alignment_factor))
 | |
|         return false;
 | |
|       break;
 | |
| 
 | |
|     // Specify an expression whose value is the CFA.
 | |
|     case DW_CFA_def_cfa_expression: {
 | |
|       if (!ParseOperands("e", &ops))
 | |
|         return false;
 | |
|       Rule *rule = new ValExpressionRule(ops.expression);
 | |
|       rules_.SetCFARule(rule);
 | |
|       if (!rule->Handle(handler_, address_,
 | |
|                         Handler::kCFARegister))
 | |
|         return false;
 | |
|       break;
 | |
|     }
 | |
| 
 | |
|     // The register's value cannot be recovered.
 | |
|     case DW_CFA_undefined: {
 | |
|       if (!ParseOperands("r", &ops) ||
 | |
|           !DoRule(ops.register_number, new UndefinedRule()))
 | |
|         return false;
 | |
|       break;
 | |
|     }
 | |
| 
 | |
|     // The register's value is unchanged from its value in the caller.
 | |
|     case DW_CFA_same_value: {
 | |
|       if (!ParseOperands("r", &ops) ||
 | |
|           !DoRule(ops.register_number, new SameValueRule()))
 | |
|         return false;
 | |
|       break;
 | |
|     }
 | |
| 
 | |
|     // Find a register at an offset from the CFA.
 | |
|     case DW_CFA_offset_extended:
 | |
|       if (!ParseOperands("ro", &ops) ||
 | |
|           !DoOffset(ops.register_number,
 | |
|                     ops.offset * cie->data_alignment_factor))
 | |
|         return false;
 | |
|       break;
 | |
| 
 | |
|     // The register is saved at an offset from the CFA.
 | |
|     case DW_CFA_offset_extended_sf:
 | |
|       if (!ParseOperands("rs", &ops) ||
 | |
|           !DoOffset(ops.register_number,
 | |
|                     ops.signed_offset * cie->data_alignment_factor))
 | |
|         return false;
 | |
|       break;
 | |
| 
 | |
|     // The register is saved at an offset from the CFA.
 | |
|     case DW_CFA_GNU_negative_offset_extended:
 | |
|       if (!ParseOperands("ro", &ops) ||
 | |
|           !DoOffset(ops.register_number,
 | |
|                     -ops.offset * cie->data_alignment_factor))
 | |
|         return false;
 | |
|       break;
 | |
| 
 | |
|     // The register's value is the sum of the CFA plus an offset.
 | |
|     case DW_CFA_val_offset:
 | |
|       if (!ParseOperands("ro", &ops) ||
 | |
|           !DoValOffset(ops.register_number,
 | |
|                        ops.offset * cie->data_alignment_factor))
 | |
|         return false;
 | |
|       break;
 | |
| 
 | |
|     // The register's value is the sum of the CFA plus an offset.
 | |
|     case DW_CFA_val_offset_sf:
 | |
|       if (!ParseOperands("rs", &ops) ||
 | |
|           !DoValOffset(ops.register_number,
 | |
|                        ops.signed_offset * cie->data_alignment_factor))
 | |
|         return false;
 | |
|       break;
 | |
| 
 | |
|     // The register has been saved in another register.
 | |
|     case DW_CFA_register: {
 | |
|       if (!ParseOperands("ro", &ops) ||
 | |
|           !DoRule(ops.register_number, new RegisterRule(ops.offset)))
 | |
|         return false;
 | |
|       break;
 | |
|     }
 | |
| 
 | |
|     // An expression yields the address at which the register is saved.
 | |
|     case DW_CFA_expression: {
 | |
|       if (!ParseOperands("re", &ops) ||
 | |
|           !DoRule(ops.register_number, new ExpressionRule(ops.expression)))
 | |
|         return false;
 | |
|       break;
 | |
|     }
 | |
| 
 | |
|     // An expression yields the caller's value for the register.
 | |
|     case DW_CFA_val_expression: {
 | |
|       if (!ParseOperands("re", &ops) ||
 | |
|           !DoRule(ops.register_number, new ValExpressionRule(ops.expression)))
 | |
|         return false;
 | |
|       break;
 | |
|     }
 | |
| 
 | |
|     // Restore the rule established for a register by the CIE.
 | |
|     case DW_CFA_restore_extended:
 | |
|       if (!ParseOperands("r", &ops) ||
 | |
|           !DoRestore( ops.register_number))
 | |
|         return false;
 | |
|       break;
 | |
| 
 | |
|     // Save the current set of rules on a stack.
 | |
|     case DW_CFA_remember_state:
 | |
|       saved_rules_.push(rules_);
 | |
|       break;
 | |
| 
 | |
|     // Pop the current set of rules off the stack.
 | |
|     case DW_CFA_restore_state: {
 | |
|       if (saved_rules_.empty()) {
 | |
|         reporter_->EmptyStateStack(entry_->offset, entry_->kind,
 | |
|                                    CursorOffset());
 | |
|         return false;
 | |
|       }
 | |
|       const RuleMap &new_rules = saved_rules_.top();
 | |
|       if (rules_.CFARule() && !new_rules.CFARule()) {
 | |
|         reporter_->ClearingCFARule(entry_->offset, entry_->kind,
 | |
|                                    CursorOffset());
 | |
|         return false;
 | |
|       }
 | |
|       rules_.HandleTransitionTo(handler_, address_, new_rules);
 | |
|       rules_ = new_rules;
 | |
|       saved_rules_.pop();
 | |
|       break;
 | |
|     }
 | |
| 
 | |
|     // No operation.  (Padding instruction.)
 | |
|     case DW_CFA_nop:
 | |
|       break;
 | |
| 
 | |
|     // A SPARC register window save: Registers 8 through 15 (%o0-%o7)
 | |
|     // are saved in registers 24 through 31 (%i0-%i7), and registers
 | |
|     // 16 through 31 (%l0-%l7 and %i0-%i7) are saved at CFA offsets
 | |
|     // (0-15 * the register size). The register numbers must be
 | |
|     // hard-coded. A GNU extension, and not a pretty one.
 | |
|     case DW_CFA_GNU_window_save: {
 | |
|       // Save %o0-%o7 in %i0-%i7.
 | |
|       for (int i = 8; i < 16; i++)
 | |
|         if (!DoRule(i, new RegisterRule(i + 16)))
 | |
|           return false;
 | |
|       // Save %l0-%l7 and %i0-%i7 at the CFA.
 | |
|       for (int i = 16; i < 32; i++)
 | |
|         // Assume that the byte reader's address size is the same as
 | |
|         // the architecture's register size. !@#%*^ hilarious.
 | |
|         if (!DoRule(i, new OffsetRule(Handler::kCFARegister,
 | |
|                                       (i - 16) * reader_->AddressSize())))
 | |
|           return false;
 | |
|       break;
 | |
|     }
 | |
| 
 | |
|     // I'm not sure what this is. GDB doesn't use it for unwinding.
 | |
|     case DW_CFA_GNU_args_size:
 | |
|       if (!ParseOperands("o", &ops)) return false;
 | |
|       break;
 | |
| 
 | |
|     // An opcode we don't recognize.
 | |
|     default: {
 | |
|       reporter_->BadInstruction(entry_->offset, entry_->kind, CursorOffset());
 | |
|       return false;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   return true;
 | |
| }
 | |
| 
 | |
| bool CallFrameInfo::State::DoDefCFA(unsigned base_register, long offset) {
 | |
|   Rule *rule = new ValOffsetRule(base_register, offset);
 | |
|   rules_.SetCFARule(rule);
 | |
|   return rule->Handle(handler_, address_,
 | |
|                       Handler::kCFARegister);
 | |
| }
 | |
| 
 | |
| bool CallFrameInfo::State::DoDefCFAOffset(long offset) {
 | |
|   Rule *cfa_rule = rules_.CFARule();
 | |
|   if (!cfa_rule) {
 | |
|     reporter_->NoCFARule(entry_->offset, entry_->kind, CursorOffset());
 | |
|     return false;
 | |
|   }
 | |
|   cfa_rule->SetOffset(offset);
 | |
|   return cfa_rule->Handle(handler_, address_,
 | |
|                           Handler::kCFARegister);
 | |
| }
 | |
| 
 | |
| bool CallFrameInfo::State::DoRule(unsigned reg, Rule *rule) {
 | |
|   rules_.SetRegisterRule(reg, rule);
 | |
|   return rule->Handle(handler_, address_, reg);
 | |
| }
 | |
| 
 | |
| bool CallFrameInfo::State::DoOffset(unsigned reg, long offset) {
 | |
|   if (!rules_.CFARule()) {
 | |
|     reporter_->NoCFARule(entry_->offset, entry_->kind, CursorOffset());
 | |
|     return false;
 | |
|   }
 | |
|   return DoRule(reg,
 | |
|                 new OffsetRule(Handler::kCFARegister, offset));
 | |
| }
 | |
| 
 | |
| bool CallFrameInfo::State::DoValOffset(unsigned reg, long offset) {
 | |
|   if (!rules_.CFARule()) {
 | |
|     reporter_->NoCFARule(entry_->offset, entry_->kind, CursorOffset());
 | |
|     return false;
 | |
|   }
 | |
|   return DoRule(reg,
 | |
|                 new ValOffsetRule(Handler::kCFARegister, offset));
 | |
| }
 | |
| 
 | |
| bool CallFrameInfo::State::DoRestore(unsigned reg) {
 | |
|   // DW_CFA_restore and DW_CFA_restore_extended don't make sense in a CIE.
 | |
|   if (entry_->kind == kCIE) {
 | |
|     reporter_->RestoreInCIE(entry_->offset, CursorOffset());
 | |
|     return false;
 | |
|   }
 | |
|   Rule *rule = cie_rules_.RegisterRule(reg);
 | |
|   if (!rule) {
 | |
|     // This isn't really the right thing to do, but since CFI generally
 | |
|     // only mentions callee-saves registers, and GCC's convention for
 | |
|     // callee-saves registers is that they are unchanged, it's a good
 | |
|     // approximation.
 | |
|     rule = new SameValueRule();
 | |
|   }
 | |
|   return DoRule(reg, rule);
 | |
| }
 | |
| 
 | |
| bool CallFrameInfo::ReadEntryPrologue(const char *cursor, Entry *entry) {
 | |
|   const char *buffer_end = buffer_ + buffer_length_;
 | |
| 
 | |
|   // Initialize enough of ENTRY for use in error reporting.
 | |
|   entry->offset = cursor - buffer_;
 | |
|   entry->start = cursor;
 | |
|   entry->kind = kUnknown;
 | |
|   entry->end = NULL;
 | |
| 
 | |
|   // Read the initial length. This sets reader_'s offset size.
 | |
|   size_t length_size;
 | |
|   uint64 length = reader_->ReadInitialLength(cursor, &length_size);
 | |
|   if (length_size > size_t(buffer_end - cursor))
 | |
|     return ReportIncomplete(entry);
 | |
|   cursor += length_size;
 | |
| 
 | |
|   // In a .eh_frame section, a length of zero marks the end of the series
 | |
|   // of entries.
 | |
|   if (length == 0 && eh_frame_) {
 | |
|     entry->kind = kTerminator;
 | |
|     entry->end = cursor;
 | |
|     return true;
 | |
|   }
 | |
| 
 | |
|   // Validate the length.
 | |
|   if (length > size_t(buffer_end - cursor))
 | |
|     return ReportIncomplete(entry);
 | |
|  
 | |
|   // The length is the number of bytes after the initial length field;
 | |
|   // we have that position handy at this point, so compute the end
 | |
|   // now. (If we're parsing 64-bit-offset DWARF on a 32-bit machine,
 | |
|   // and the length didn't fit in a size_t, we would have rejected it
 | |
|   // above.)
 | |
|   entry->end = cursor + length;
 | |
| 
 | |
|   // Parse the next field: either the offset of a CIE or a CIE id.
 | |
|   size_t offset_size = reader_->OffsetSize();
 | |
|   if (offset_size > size_t(entry->end - cursor)) return ReportIncomplete(entry);
 | |
|   entry->id = reader_->ReadOffset(cursor);
 | |
| 
 | |
|   // Don't advance cursor past id field yet; in .eh_frame data we need
 | |
|   // the id's position to compute the section offset of an FDE's CIE.
 | |
| 
 | |
|   // Now we can decide what kind of entry this is.
 | |
|   if (eh_frame_) {
 | |
|     // In .eh_frame data, an ID of zero marks the entry as a CIE, and
 | |
|     // anything else is an offset from the id field of the FDE to the start
 | |
|     // of the CIE.
 | |
|     if (entry->id == 0) {
 | |
|       entry->kind = kCIE;
 | |
|     } else {
 | |
|       entry->kind = kFDE;
 | |
|       // Turn the offset from the id into an offset from the buffer's start.
 | |
|       entry->id = (cursor - buffer_) - entry->id;
 | |
|     }
 | |
|   } else {
 | |
|     // In DWARF CFI data, an ID of ~0 (of the appropriate width, given the
 | |
|     // offset size for the entry) marks the entry as a CIE, and anything
 | |
|     // else is the offset of the CIE from the beginning of the section.
 | |
|     if (offset_size == 4)
 | |
|       entry->kind = (entry->id == 0xffffffff) ? kCIE : kFDE;
 | |
|     else {
 | |
|       assert(offset_size == 8);
 | |
|       entry->kind = (entry->id == 0xffffffffffffffffULL) ? kCIE : kFDE;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   // Now advance cursor past the id.
 | |
|    cursor += offset_size;
 | |
|  
 | |
|   // The fields specific to this kind of entry start here.
 | |
|   entry->fields = cursor;
 | |
| 
 | |
|   entry->cie = NULL;
 | |
| 
 | |
|   return true;
 | |
| }
 | |
| 
 | |
| bool CallFrameInfo::ReadCIEFields(CIE *cie) {
 | |
|   const char *cursor = cie->fields;
 | |
|   size_t len;
 | |
| 
 | |
|   assert(cie->kind == kCIE);
 | |
| 
 | |
|   // Prepare for early exit.
 | |
|   cie->version = 0;
 | |
|   cie->augmentation.clear();
 | |
|   cie->code_alignment_factor = 0;
 | |
|   cie->data_alignment_factor = 0;
 | |
|   cie->return_address_register = 0;
 | |
|   cie->has_z_augmentation = false;
 | |
|   cie->pointer_encoding = DW_EH_PE_absptr;
 | |
|   cie->instructions = 0;
 | |
| 
 | |
|   // Parse the version number.
 | |
|   if (cie->end - cursor < 1)
 | |
|     return ReportIncomplete(cie);
 | |
|   cie->version = reader_->ReadOneByte(cursor);
 | |
|   cursor++;
 | |
| 
 | |
|   // If we don't recognize the version, we can't parse any more fields of the
 | |
|   // CIE. For DWARF CFI, we handle versions 1 through 3 (there was never a
 | |
|   // version 2 of CFI data). For .eh_frame, we handle versions 1 and 3 as well;
 | |
|   // the difference between those versions seems to be the same as for
 | |
|   // .debug_frame.
 | |
|   if (cie->version < 1 || cie->version > 3) {
 | |
|     reporter_->UnrecognizedVersion(cie->offset, cie->version);
 | |
|     return false;
 | |
|   }
 | |
| 
 | |
|   const char *augmentation_start = cursor;
 | |
|   const void *augmentation_end =
 | |
|       memchr(augmentation_start, '\0', cie->end - augmentation_start);
 | |
|   if (! augmentation_end) return ReportIncomplete(cie);
 | |
|   cursor = static_cast<const char *>(augmentation_end);
 | |
|   cie->augmentation = string(augmentation_start,
 | |
|                                   cursor - augmentation_start);
 | |
|   // Skip the terminating '\0'.
 | |
|   cursor++;
 | |
| 
 | |
|   // Is this CFI augmented?
 | |
|   if (!cie->augmentation.empty()) {
 | |
|     // Is it an augmentation we recognize?
 | |
|     if (cie->augmentation[0] == DW_Z_augmentation_start) {
 | |
|       // Linux C++ ABI 'z' augmentation, used for exception handling data.
 | |
|       cie->has_z_augmentation = true;
 | |
|     } else {
 | |
|       // Not an augmentation we recognize. Augmentations can have arbitrary
 | |
|       // effects on the form of rest of the content, so we have to give up.
 | |
|       reporter_->UnrecognizedAugmentation(cie->offset, cie->augmentation);
 | |
|       return false;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   // Parse the code alignment factor.
 | |
|   cie->code_alignment_factor = reader_->ReadUnsignedLEB128(cursor, &len);
 | |
|   if (size_t(cie->end - cursor) < len) return ReportIncomplete(cie);
 | |
|   cursor += len;
 | |
|   
 | |
|   // Parse the data alignment factor.
 | |
|   cie->data_alignment_factor = reader_->ReadSignedLEB128(cursor, &len);
 | |
|   if (size_t(cie->end - cursor) < len) return ReportIncomplete(cie);
 | |
|   cursor += len;
 | |
|   
 | |
|   // Parse the return address register. This is a ubyte in version 1, and
 | |
|   // a ULEB128 in version 3.
 | |
|   if (cie->version == 1) {
 | |
|     if (cursor >= cie->end) return ReportIncomplete(cie);
 | |
|     cie->return_address_register = uint8(*cursor++);
 | |
|   } else {
 | |
|     cie->return_address_register = reader_->ReadUnsignedLEB128(cursor, &len);
 | |
|     if (size_t(cie->end - cursor) < len) return ReportIncomplete(cie);
 | |
|     cursor += len;
 | |
|   }
 | |
| 
 | |
|   // If we have a 'z' augmentation string, find the augmentation data and
 | |
|   // use the augmentation string to parse it.
 | |
|   if (cie->has_z_augmentation) {
 | |
|     uint64_t data_size = reader_->ReadUnsignedLEB128(cursor, &len);
 | |
|     if (size_t(cie->end - cursor) < len + data_size)
 | |
|       return ReportIncomplete(cie);
 | |
|     cursor += len;
 | |
|     const char *data = cursor;
 | |
|     cursor += data_size;
 | |
|     const char *data_end = cursor;
 | |
| 
 | |
|     cie->has_z_lsda = false;
 | |
|     cie->has_z_personality = false;
 | |
|     cie->has_z_signal_frame = false;
 | |
| 
 | |
|     // Walk the augmentation string, and extract values from the
 | |
|     // augmentation data as the string directs.
 | |
|     for (size_t i = 1; i < cie->augmentation.size(); i++) {
 | |
|       switch (cie->augmentation[i]) {
 | |
|         case DW_Z_has_LSDA:
 | |
|           // The CIE's augmentation data holds the language-specific data
 | |
|           // area pointer's encoding, and the FDE's augmentation data holds
 | |
|           // the pointer itself.
 | |
|           cie->has_z_lsda = true;
 | |
|           // Fetch the LSDA encoding from the augmentation data.
 | |
|           if (data >= data_end) return ReportIncomplete(cie);
 | |
|           cie->lsda_encoding = DwarfPointerEncoding(*data++);
 | |
|           if (!reader_->ValidEncoding(cie->lsda_encoding)) {
 | |
|             reporter_->InvalidPointerEncoding(cie->offset, cie->lsda_encoding);
 | |
|             return false;
 | |
|           }
 | |
|           // Don't check if the encoding is usable here --- we haven't
 | |
|           // read the FDE's fields yet, so we're not prepared for
 | |
|           // DW_EH_PE_funcrel, although that's a fine encoding for the
 | |
|           // LSDA to use, since it appears in the FDE.
 | |
|           break;
 | |
| 
 | |
|         case DW_Z_has_personality_routine:
 | |
|           // The CIE's augmentation data holds the personality routine
 | |
|           // pointer's encoding, followed by the pointer itself.
 | |
|           cie->has_z_personality = true;
 | |
|           // Fetch the personality routine pointer's encoding from the
 | |
|           // augmentation data.
 | |
|           if (data >= data_end) return ReportIncomplete(cie);
 | |
|           cie->personality_encoding = DwarfPointerEncoding(*data++);
 | |
|           if (!reader_->ValidEncoding(cie->personality_encoding)) {
 | |
|             reporter_->InvalidPointerEncoding(cie->offset,
 | |
|                                               cie->personality_encoding);
 | |
|             return false;
 | |
|           }
 | |
|           if (!reader_->UsableEncoding(cie->personality_encoding)) {
 | |
|             reporter_->UnusablePointerEncoding(cie->offset,
 | |
|                                                cie->personality_encoding);
 | |
|             return false;
 | |
|           }
 | |
|           // Fetch the personality routine's pointer itself from the data.
 | |
|           cie->personality_address =
 | |
|             reader_->ReadEncodedPointer(data, cie->personality_encoding,
 | |
|                                         &len);
 | |
|           if (len > size_t(data_end - data))
 | |
|             return ReportIncomplete(cie);
 | |
|           data += len;
 | |
|           break;
 | |
| 
 | |
|         case DW_Z_has_FDE_address_encoding:
 | |
|           // The CIE's augmentation data holds the pointer encoding to use
 | |
|           // for addresses in the FDE.
 | |
|           if (data >= data_end) return ReportIncomplete(cie);
 | |
|           cie->pointer_encoding = DwarfPointerEncoding(*data++);
 | |
|           if (!reader_->ValidEncoding(cie->pointer_encoding)) {
 | |
|             reporter_->InvalidPointerEncoding(cie->offset,
 | |
|                                               cie->pointer_encoding);
 | |
|             return false;
 | |
|           }
 | |
|           if (!reader_->UsableEncoding(cie->pointer_encoding)) {
 | |
|             reporter_->UnusablePointerEncoding(cie->offset,
 | |
|                                                cie->pointer_encoding);
 | |
|             return false;
 | |
|           }
 | |
|           break;
 | |
| 
 | |
|         case DW_Z_is_signal_trampoline:
 | |
|           // Frames using this CIE are signal delivery frames.
 | |
|           cie->has_z_signal_frame = true;
 | |
|           break;
 | |
| 
 | |
|         default:
 | |
|           // An augmentation we don't recognize.
 | |
|           reporter_->UnrecognizedAugmentation(cie->offset, cie->augmentation);
 | |
|           return false;
 | |
|       }
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   // The CIE's instructions start here.
 | |
|   cie->instructions = cursor;
 | |
| 
 | |
|   return true;
 | |
| }
 | |
|   
 | |
| bool CallFrameInfo::ReadFDEFields(FDE *fde) {
 | |
|   const char *cursor = fde->fields;
 | |
|   size_t size;
 | |
| 
 | |
|   fde->address = reader_->ReadEncodedPointer(cursor, fde->cie->pointer_encoding,
 | |
|                                              &size);
 | |
|   if (size > size_t(fde->end - cursor))
 | |
|     return ReportIncomplete(fde);
 | |
|   cursor += size;
 | |
|   reader_->SetFunctionBase(fde->address);
 | |
| 
 | |
|   // For the length, we strip off the upper nybble of the encoding used for
 | |
|   // the starting address.
 | |
|   DwarfPointerEncoding length_encoding =
 | |
|     DwarfPointerEncoding(fde->cie->pointer_encoding & 0x0f);
 | |
|   fde->size = reader_->ReadEncodedPointer(cursor, length_encoding, &size);
 | |
|   if (size > size_t(fde->end - cursor))
 | |
|     return ReportIncomplete(fde);
 | |
|   cursor += size;
 | |
| 
 | |
|   // If the CIE has a 'z' augmentation string, then augmentation data
 | |
|   // appears here.
 | |
|   if (fde->cie->has_z_augmentation) {
 | |
|     uint64_t data_size = reader_->ReadUnsignedLEB128(cursor, &size);
 | |
|     if (size_t(fde->end - cursor) < size + data_size)
 | |
|       return ReportIncomplete(fde);
 | |
|     cursor += size;
 | |
|     
 | |
|     // In the abstract, we should walk the augmentation string, and extract
 | |
|     // items from the FDE's augmentation data as we encounter augmentation
 | |
|     // string characters that specify their presence: the ordering of items
 | |
|     // in the augmentation string determines the arrangement of values in
 | |
|     // the augmentation data.
 | |
|     //
 | |
|     // In practice, there's only ever one value in FDE augmentation data
 | |
|     // that we support --- the LSDA pointer --- and we have to bail if we
 | |
|     // see any unrecognized augmentation string characters. So if there is
 | |
|     // anything here at all, we know what it is, and where it starts.
 | |
|     if (fde->cie->has_z_lsda) {
 | |
|       // Check whether the LSDA's pointer encoding is usable now: only once
 | |
|       // we've parsed the FDE's starting address do we call reader_->
 | |
|       // SetFunctionBase, so that the DW_EH_PE_funcrel encoding becomes
 | |
|       // usable.
 | |
|       if (!reader_->UsableEncoding(fde->cie->lsda_encoding)) {
 | |
|         reporter_->UnusablePointerEncoding(fde->cie->offset,
 | |
|                                            fde->cie->lsda_encoding);
 | |
|         return false;
 | |
|       }
 | |
| 
 | |
|       fde->lsda_address =
 | |
|         reader_->ReadEncodedPointer(cursor, fde->cie->lsda_encoding, &size);
 | |
|       if (size > data_size)
 | |
|         return ReportIncomplete(fde);
 | |
|       // Ideally, we would also complain here if there were unconsumed
 | |
|       // augmentation data.
 | |
|     }
 | |
| 
 | |
|     cursor += data_size;
 | |
|   }
 | |
| 
 | |
|   // The FDE's instructions start after those.
 | |
|   fde->instructions = cursor;
 | |
| 
 | |
|   return true;
 | |
| }
 | |
|   
 | |
| bool CallFrameInfo::Start() {
 | |
|   const char *buffer_end = buffer_ + buffer_length_;
 | |
|   const char *cursor;
 | |
|   bool all_ok = true;
 | |
|   const char *entry_end;
 | |
|   bool ok;
 | |
| 
 | |
|   // Traverse all the entries in buffer_, skipping CIEs and offering
 | |
|   // FDEs to the handler.
 | |
|   for (cursor = buffer_; cursor < buffer_end;
 | |
|        cursor = entry_end, all_ok = all_ok && ok) {
 | |
|     FDE fde;
 | |
| 
 | |
|     // Make it easy to skip this entry with 'continue': assume that
 | |
|     // things are not okay until we've checked all the data, and
 | |
|     // prepare the address of the next entry.
 | |
|     ok = false;
 | |
| 
 | |
|     // Read the entry's prologue.
 | |
|     if (!ReadEntryPrologue(cursor, &fde)) {
 | |
|       if (!fde.end) {
 | |
|         // If we couldn't even figure out this entry's extent, then we
 | |
|         // must stop processing entries altogether.
 | |
|         all_ok = false;
 | |
|         break;
 | |
|       }
 | |
|       entry_end = fde.end;
 | |
|       continue;
 | |
|     }
 | |
| 
 | |
|     // The next iteration picks up after this entry.
 | |
|     entry_end = fde.end;
 | |
| 
 | |
|     // Did we see an .eh_frame terminating mark?
 | |
|     if (fde.kind == kTerminator) {
 | |
|       // If there appears to be more data left in the section after the
 | |
|       // terminating mark, warn the user. But this is just a warning;
 | |
|       // we leave all_ok true.
 | |
|       if (fde.end < buffer_end) reporter_->EarlyEHTerminator(fde.offset);
 | |
|       break;
 | |
|     }
 | |
| 
 | |
|     // In this loop, we skip CIEs. We only parse them fully when we
 | |
|     // parse an FDE that refers to them. This limits our memory
 | |
|     // consumption (beyond the buffer itself) to that needed to
 | |
|     // process the largest single entry.
 | |
|     if (fde.kind != kFDE) {
 | |
|       ok = true;
 | |
|       continue;
 | |
|     }
 | |
| 
 | |
|     // Validate the CIE pointer.
 | |
|     if (fde.id > buffer_length_) {
 | |
|       reporter_->CIEPointerOutOfRange(fde.offset, fde.id);
 | |
|       continue;
 | |
|     }
 | |
|       
 | |
|     CIE cie;
 | |
| 
 | |
|     // Parse this FDE's CIE header.
 | |
|     if (!ReadEntryPrologue(buffer_ + fde.id, &cie))
 | |
|       continue;
 | |
|     // This had better be an actual CIE.
 | |
|     if (cie.kind != kCIE) {
 | |
|       reporter_->BadCIEId(fde.offset, fde.id);
 | |
|       continue;
 | |
|     }
 | |
|     if (!ReadCIEFields(&cie))
 | |
|       continue;
 | |
| 
 | |
|     // We now have the values that govern both the CIE and the FDE.
 | |
|     cie.cie = &cie;
 | |
|     fde.cie = &cie;
 | |
| 
 | |
|     // Parse the FDE's header.
 | |
|     if (!ReadFDEFields(&fde))
 | |
|       continue;
 | |
| 
 | |
|     // Call Entry to ask the consumer if they're interested.
 | |
|     if (!handler_->Entry(fde.offset, fde.address, fde.size,
 | |
|                          cie.version, cie.augmentation,
 | |
|                          cie.return_address_register)) {
 | |
|       // The handler isn't interested in this entry. That's not an error.
 | |
|       ok = true;
 | |
|       continue;
 | |
|     }
 | |
|                          
 | |
|     if (cie.has_z_augmentation) {
 | |
|       // Report the personality routine address, if we have one.
 | |
|       if (cie.has_z_personality) {
 | |
|         if (!handler_
 | |
|             ->PersonalityRoutine(cie.personality_address,
 | |
|                                  IsIndirectEncoding(cie.personality_encoding)))
 | |
|           continue;
 | |
|       }
 | |
| 
 | |
|       // Report the language-specific data area address, if we have one.
 | |
|       if (cie.has_z_lsda) {
 | |
|         if (!handler_
 | |
|             ->LanguageSpecificDataArea(fde.lsda_address,
 | |
|                                        IsIndirectEncoding(cie.lsda_encoding)))
 | |
|           continue;
 | |
|       }
 | |
| 
 | |
|       // If this is a signal-handling frame, report that.
 | |
|       if (cie.has_z_signal_frame) {
 | |
|         if (!handler_->SignalHandler())
 | |
|           continue;
 | |
|       }
 | |
|     }
 | |
| 
 | |
|     // Interpret the CIE's instructions, and then the FDE's instructions.
 | |
|     State state(reader_, handler_, reporter_, fde.address);
 | |
|     ok = state.InterpretCIE(cie) && state.InterpretFDE(fde);
 | |
| 
 | |
|     // Tell the ByteReader that the function start address from the
 | |
|     // FDE header is no longer valid.
 | |
|     reader_->ClearFunctionBase();
 | |
| 
 | |
|     // Report the end of the entry.
 | |
|     handler_->End();
 | |
|   }
 | |
| 
 | |
|   return all_ok;
 | |
| }
 | |
| 
 | |
| const char *CallFrameInfo::KindName(EntryKind kind) {
 | |
|   if (kind == CallFrameInfo::kUnknown)
 | |
|     return "entry";
 | |
|   else if (kind == CallFrameInfo::kCIE)
 | |
|     return "common information entry";
 | |
|   else if (kind == CallFrameInfo::kFDE)
 | |
|     return "frame description entry";
 | |
|   else {
 | |
|     assert (kind == CallFrameInfo::kTerminator);
 | |
|     return ".eh_frame sequence terminator";
 | |
|   }
 | |
| }
 | |
| 
 | |
| bool CallFrameInfo::ReportIncomplete(Entry *entry) {
 | |
|   reporter_->Incomplete(entry->offset, entry->kind);
 | |
|   return false;
 | |
| }
 | |
| 
 | |
| void CallFrameInfo::Reporter::Incomplete(uint64 offset,
 | |
|                                          CallFrameInfo::EntryKind kind) {
 | |
|   fprintf(stderr,
 | |
|           "%s: CFI %s at offset 0x%llx in '%s': entry ends early\n",
 | |
|           filename_.c_str(), CallFrameInfo::KindName(kind), offset,
 | |
|           section_.c_str());
 | |
| }
 | |
| 
 | |
| void CallFrameInfo::Reporter::EarlyEHTerminator(uint64 offset) {
 | |
|   fprintf(stderr,
 | |
|           "%s: CFI at offset 0x%llx in '%s': saw end-of-data marker"
 | |
|           " before end of section contents\n",
 | |
|           filename_.c_str(), offset, section_.c_str());
 | |
| }
 | |
| 
 | |
| void CallFrameInfo::Reporter::CIEPointerOutOfRange(uint64 offset,
 | |
|                                                    uint64 cie_offset) {
 | |
|   fprintf(stderr,
 | |
|           "%s: CFI frame description entry at offset 0x%llx in '%s':"
 | |
|           " CIE pointer is out of range: 0x%llx\n",
 | |
|           filename_.c_str(), offset, section_.c_str(), cie_offset);
 | |
| }
 | |
| 
 | |
| void CallFrameInfo::Reporter::BadCIEId(uint64 offset, uint64 cie_offset) {
 | |
|   fprintf(stderr,
 | |
|           "%s: CFI frame description entry at offset 0x%llx in '%s':"
 | |
|           " CIE pointer does not point to a CIE: 0x%llx\n",
 | |
|           filename_.c_str(), offset, section_.c_str(), cie_offset);
 | |
| }
 | |
| 
 | |
| void CallFrameInfo::Reporter::UnrecognizedVersion(uint64 offset, int version) {
 | |
|   fprintf(stderr,
 | |
|           "%s: CFI frame description entry at offset 0x%llx in '%s':"
 | |
|           " CIE specifies unrecognized version: %d\n",
 | |
|           filename_.c_str(), offset, section_.c_str(), version);
 | |
| }
 | |
| 
 | |
| void CallFrameInfo::Reporter::UnrecognizedAugmentation(uint64 offset,
 | |
|                                                        const string &aug) {
 | |
|   fprintf(stderr,
 | |
|           "%s: CFI frame description entry at offset 0x%llx in '%s':"
 | |
|           " CIE specifies unrecognized augmentation: '%s'\n",
 | |
|           filename_.c_str(), offset, section_.c_str(), aug.c_str());
 | |
| }
 | |
| 
 | |
| void CallFrameInfo::Reporter::InvalidPointerEncoding(uint64 offset,
 | |
|                                                      uint8 encoding) {
 | |
|   fprintf(stderr,
 | |
|           "%s: CFI common information entry at offset 0x%llx in '%s':"
 | |
|           " 'z' augmentation specifies invalid pointer encoding: 0x%02x\n",
 | |
|           filename_.c_str(), offset, section_.c_str(), encoding);
 | |
| }
 | |
| 
 | |
| void CallFrameInfo::Reporter::UnusablePointerEncoding(uint64 offset,
 | |
|                                                       uint8 encoding) {
 | |
|   fprintf(stderr,
 | |
|           "%s: CFI common information entry at offset 0x%llx in '%s':"
 | |
|           " 'z' augmentation specifies a pointer encoding for which"
 | |
|           " we have no base address: 0x%02x\n",
 | |
|           filename_.c_str(), offset, section_.c_str(), encoding);
 | |
| }
 | |
| 
 | |
| void CallFrameInfo::Reporter::RestoreInCIE(uint64 offset, uint64 insn_offset) {
 | |
|   fprintf(stderr,
 | |
|           "%s: CFI common information entry at offset 0x%llx in '%s':"
 | |
|           " the DW_CFA_restore instruction at offset 0x%llx"
 | |
|           " cannot be used in a common information entry\n",
 | |
|           filename_.c_str(), offset, section_.c_str(), insn_offset);
 | |
| }
 | |
| 
 | |
| void CallFrameInfo::Reporter::BadInstruction(uint64 offset,
 | |
|                                              CallFrameInfo::EntryKind kind,
 | |
|                                              uint64 insn_offset) {
 | |
|   fprintf(stderr,
 | |
|           "%s: CFI %s at offset 0x%llx in section '%s':"
 | |
|           " the instruction at offset 0x%llx is unrecognized\n",
 | |
|           filename_.c_str(), CallFrameInfo::KindName(kind),
 | |
|           offset, section_.c_str(), insn_offset);
 | |
| }
 | |
| 
 | |
| void CallFrameInfo::Reporter::NoCFARule(uint64 offset,
 | |
|                                         CallFrameInfo::EntryKind kind,
 | |
|                                         uint64 insn_offset) {
 | |
|   fprintf(stderr,
 | |
|           "%s: CFI %s at offset 0x%llx in section '%s':"
 | |
|           " the instruction at offset 0x%llx assumes that a CFA rule has"
 | |
|           " been set, but none has been set\n",
 | |
|           filename_.c_str(), CallFrameInfo::KindName(kind), offset,
 | |
|           section_.c_str(), insn_offset);
 | |
| }
 | |
| 
 | |
| void CallFrameInfo::Reporter::EmptyStateStack(uint64 offset,
 | |
|                                               CallFrameInfo::EntryKind kind,
 | |
|                                               uint64 insn_offset) {
 | |
|   fprintf(stderr,
 | |
|           "%s: CFI %s at offset 0x%llx in section '%s':"
 | |
|           " the DW_CFA_restore_state instruction at offset 0x%llx"
 | |
|           " should pop a saved state from the stack, but the stack is empty\n",
 | |
|           filename_.c_str(), CallFrameInfo::KindName(kind), offset,
 | |
|           section_.c_str(), insn_offset);
 | |
| }
 | |
| 
 | |
| void CallFrameInfo::Reporter::ClearingCFARule(uint64 offset,
 | |
|                                               CallFrameInfo::EntryKind kind,
 | |
|                                               uint64 insn_offset) {
 | |
|   fprintf(stderr,
 | |
|           "%s: CFI %s at offset 0x%llx in section '%s':"
 | |
|           " the DW_CFA_restore_state instruction at offset 0x%llx"
 | |
|           " would clear the CFA rule in effect\n",
 | |
|           filename_.c_str(), CallFrameInfo::KindName(kind), offset,
 | |
|           section_.c_str(), insn_offset);
 | |
| }
 | |
| 
 | |
| }  // namespace dwarf2reader
 |