source/Plugins/SymbolFile/DWARF/DWARFDebugAbbrev.cpp

   1 //===-- DWARFDebugAbbrev.cpp ------------------------------------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "DWARFDebugAbbrev.h"
  11 #include "DWARFDataExtractor.h"
  12 #include "lldb/Core/Stream.h"
  13
  14 using namespace lldb;
  15 using namespace lldb_private;
  16 using namespace std;
  17
  18 //----------------------------------------------------------------------
  19 // DWARFAbbreviationDeclarationSet::Clear()
  20 //----------------------------------------------------------------------
  21 void DWARFAbbreviationDeclarationSet::Clear() {
  22   m_idx_offset = 0;
  23   m_decls.clear();
  24 }
  25
  26 //----------------------------------------------------------------------
  27 // DWARFAbbreviationDeclarationSet::Extract()
  28 //----------------------------------------------------------------------
  29 bool DWARFAbbreviationDeclarationSet::Extract(const DWARFDataExtractor &data,
  30                                               lldb::offset_t *offset_ptr) {
  31   const lldb::offset_t begin_offset = *offset_ptr;
  32   m_offset = begin_offset;
  33   Clear();
  34   DWARFAbbreviationDeclaration abbrevDeclaration;
  35   dw_uleb128_t prev_abbr_code = 0;
  36   while (abbrevDeclaration.Extract(data, offset_ptr)) {
  37     m_decls.push_back(abbrevDeclaration);
  38     if (m_idx_offset == 0)
  39       m_idx_offset = abbrevDeclaration.Code();
  40     else {
  41       if (prev_abbr_code + 1 != abbrevDeclaration.Code())
  42         m_idx_offset =
  43             UINT32_MAX; // Out of order indexes, we can't do O(1) lookups...
  44     }
  45     prev_abbr_code = abbrevDeclaration.Code();
  46   }
  47   return begin_offset != *offset_ptr;
  48 }
  49
  50 //----------------------------------------------------------------------
  51 // DWARFAbbreviationDeclarationSet::Dump()
  52 //----------------------------------------------------------------------
  53 void DWARFAbbreviationDeclarationSet::Dump(Stream *s) const {
  54   std::for_each(
  55       m_decls.begin(), m_decls.end(),
  56       bind2nd(std::mem_fun_ref(&DWARFAbbreviationDeclaration::Dump), s));
  57 }
  58
  59 //----------------------------------------------------------------------
  60 // DWARFAbbreviationDeclarationSet::GetAbbreviationDeclaration()
  61 //----------------------------------------------------------------------
  62 const DWARFAbbreviationDeclaration *
  63 DWARFAbbreviationDeclarationSet::GetAbbreviationDeclaration(
  64     dw_uleb128_t abbrCode) const {
  65   if (m_idx_offset == UINT32_MAX) {
  66     DWARFAbbreviationDeclarationCollConstIter pos;
  67     DWARFAbbreviationDeclarationCollConstIter end = m_decls.end();
  68     for (pos = m_decls.begin(); pos != end; ++pos) {
  69       if (pos->Code() == abbrCode)
  70         return &(*pos);
  71     }
  72   } else {
  73     uint32_t idx = abbrCode - m_idx_offset;
  74     if (idx < m_decls.size())
  75       return &m_decls[idx];
  76   }
  77   return NULL;
  78 }
  79
  80 //----------------------------------------------------------------------
  81 // DWARFAbbreviationDeclarationSet::AppendAbbrevDeclSequential()
  82 //
  83 // Append an abbreviation declaration with a sequential code for O(n)
  84 // lookups. Handy when creating an DWARFAbbreviationDeclarationSet.
  85 //----------------------------------------------------------------------
  86 dw_uleb128_t DWARFAbbreviationDeclarationSet::AppendAbbrevDeclSequential(
  87     const DWARFAbbreviationDeclaration &abbrevDecl) {
  88   // Get the next abbreviation code based on our current array size
  89   dw_uleb128_t code = m_decls.size() + 1;
  90
  91   // Push the new declaration on the back
  92   m_decls.push_back(abbrevDecl);
  93
  94   // Update the code for this new declaration
  95   m_decls.back().SetCode(code);
  96
  97   return code; // return the new abbreviation code!
  98 }
  99
 100 //----------------------------------------------------------------------
 101 // Encode
 102 //
 103 // Encode the abbreviation table onto the end of the buffer provided
 104 // into a byte representation as would be found in a ".debug_abbrev"
 105 // debug information section.
 106 //----------------------------------------------------------------------
 107 // void
 108 // DWARFAbbreviationDeclarationSet::Encode(BinaryStreamBuf& debug_abbrev_buf)
 109 // const
 110 //{
 111 //  DWARFAbbreviationDeclarationCollConstIter pos;
 112 //  DWARFAbbreviationDeclarationCollConstIter end = m_decls.end();
 113 //  for (pos = m_decls.begin(); pos != end; ++pos)
 114 //      pos->Append(debug_abbrev_buf);
 115 //  debug_abbrev_buf.Append8(0);
 116 //}
 117
 118 //----------------------------------------------------------------------
 119 // DWARFDebugAbbrev constructor
 120 //----------------------------------------------------------------------
 121 DWARFDebugAbbrev::DWARFDebugAbbrev()
 122     : m_abbrevCollMap(), m_prev_abbr_offset_pos(m_abbrevCollMap.end()) {}
 123
 124 //----------------------------------------------------------------------
 125 // DWARFDebugAbbrev::Parse()
 126 //----------------------------------------------------------------------
 127 void DWARFDebugAbbrev::Parse(const DWARFDataExtractor &data) {
 128   lldb::offset_t offset = 0;
 129
 130   while (data.ValidOffset(offset)) {
 131     uint32_t initial_cu_offset = offset;
 132     DWARFAbbreviationDeclarationSet abbrevDeclSet;
 133
 134     if (abbrevDeclSet.Extract(data, &offset))
 135       m_abbrevCollMap[initial_cu_offset] = abbrevDeclSet;
 136     else
 137       break;
 138   }
 139   m_prev_abbr_offset_pos = m_abbrevCollMap.end();
 140 }
 141
 142 //----------------------------------------------------------------------
 143 // DWARFDebugAbbrev::Dump()
 144 //----------------------------------------------------------------------
 145 void DWARFDebugAbbrev::Dump(Stream *s) const {
 146   if (m_abbrevCollMap.empty()) {
 147     s->PutCString("< EMPTY >\n");
 148     return;
 149   }
 150
 151   DWARFAbbreviationDeclarationCollMapConstIter pos;
 152   for (pos = m_abbrevCollMap.begin(); pos != m_abbrevCollMap.end(); ++pos) {
 153     s->Printf("Abbrev table for offset: 0x%8.8x\n", pos->first);
 154     pos->second.Dump(s);
 155   }
 156 }
 157
 158 //----------------------------------------------------------------------
 159 // DWARFDebugAbbrev::GetAbbreviationDeclarationSet()
 160 //----------------------------------------------------------------------
 161 const DWARFAbbreviationDeclarationSet *
 162 DWARFDebugAbbrev::GetAbbreviationDeclarationSet(
 163     dw_offset_t cu_abbr_offset) const {
 164   DWARFAbbreviationDeclarationCollMapConstIter end = m_abbrevCollMap.end();
 165   DWARFAbbreviationDeclarationCollMapConstIter pos;
 166   if (m_prev_abbr_offset_pos != end &&
 167       m_prev_abbr_offset_pos->first == cu_abbr_offset)
 168     return &(m_prev_abbr_offset_pos->second);
 169   else {
 170     pos = m_abbrevCollMap.find(cu_abbr_offset);
 171     m_prev_abbr_offset_pos = pos;
 172   }
 173
 174   if (pos != m_abbrevCollMap.end())
 175     return &(pos->second);
 176   return NULL;
 177 }