contrib/llvm/tools/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugAbbrev.cpp

   1 //===-- DWARFDebugAbbrev.cpp ------------------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "DWARFDebugAbbrev.h"
  10 #include "DWARFDataExtractor.h"
  11 #include "lldb/Utility/Stream.h"
  12
  13 using namespace lldb;
  14 using namespace lldb_private;
  15 using namespace std;
  16
  17 // DWARFAbbreviationDeclarationSet::Clear()
  18 void DWARFAbbreviationDeclarationSet::Clear() {
  19   m_idx_offset = 0;
  20   m_decls.clear();
  21 }
  22
  23 // DWARFAbbreviationDeclarationSet::Extract()
  24 llvm::Error
  25 DWARFAbbreviationDeclarationSet::extract(const DWARFDataExtractor &data,
  26                                          lldb::offset_t *offset_ptr) {
  27   const lldb::offset_t begin_offset = *offset_ptr;
  28   m_offset = begin_offset;
  29   Clear();
  30   DWARFAbbreviationDeclaration abbrevDeclaration;
  31   dw_uleb128_t prev_abbr_code = 0;
  32   while (true) {
  33     llvm::Expected<DWARFEnumState> es =
  34         abbrevDeclaration.extract(data, offset_ptr);
  35     if (!es)
  36       return es.takeError();
  37     if (*es == DWARFEnumState::Complete)
  38       break;
  39     m_decls.push_back(abbrevDeclaration);
  40     if (m_idx_offset == 0)
  41       m_idx_offset = abbrevDeclaration.Code();
  42     else if (prev_abbr_code + 1 != abbrevDeclaration.Code()) {
  43       // Out of order indexes, we can't do O(1) lookups...
  44       m_idx_offset = UINT32_MAX;
  45     }
  46     prev_abbr_code = abbrevDeclaration.Code();
  47   }
  48   return llvm::ErrorSuccess();
  49 }
  50
  51 // DWARFAbbreviationDeclarationSet::GetAbbreviationDeclaration()
  52 const DWARFAbbreviationDeclaration *
  53 DWARFAbbreviationDeclarationSet::GetAbbreviationDeclaration(
  54     dw_uleb128_t abbrCode) const {
  55   if (m_idx_offset == UINT32_MAX) {
  56     DWARFAbbreviationDeclarationCollConstIter pos;
  57     DWARFAbbreviationDeclarationCollConstIter end = m_decls.end();
  58     for (pos = m_decls.begin(); pos != end; ++pos) {
  59       if (pos->Code() == abbrCode)
  60         return &(*pos);
  61     }
  62   } else {
  63     uint32_t idx = abbrCode - m_idx_offset;
  64     if (idx < m_decls.size())
  65       return &m_decls[idx];
  66   }
  67   return nullptr;
  68 }
  69
  70
  71 // DWARFAbbreviationDeclarationSet::GetUnsupportedForms()
  72 void DWARFAbbreviationDeclarationSet::GetUnsupportedForms(
  73     std::set<dw_form_t> &invalid_forms) const {
  74   for (const auto &abbr_decl : m_decls) {
  75     const size_t num_attrs = abbr_decl.NumAttributes();
  76     for (size_t i=0; i<num_attrs; ++i) {
  77       dw_form_t form = abbr_decl.GetFormByIndex(i);
  78       if (!DWARFFormValue::FormIsSupported(form))
  79         invalid_forms.insert(form);
  80     }
  81   }
  82 }
  83
  84 // Encode
  85 //
  86 // Encode the abbreviation table onto the end of the buffer provided into a
  87 // byte representation as would be found in a ".debug_abbrev" debug information
  88 // section.
  89 // void
  90 // DWARFAbbreviationDeclarationSet::Encode(BinaryStreamBuf& debug_abbrev_buf)
  91 // const
  92 //{
  93 //  DWARFAbbreviationDeclarationCollConstIter pos;
  94 //  DWARFAbbreviationDeclarationCollConstIter end = m_decls.end();
  95 //  for (pos = m_decls.begin(); pos != end; ++pos)
  96 //      pos->Append(debug_abbrev_buf);
  97 //  debug_abbrev_buf.Append8(0);
  98 //}
  99
 100 // DWARFDebugAbbrev constructor
 101 DWARFDebugAbbrev::DWARFDebugAbbrev()
 102     : m_abbrevCollMap(), m_prev_abbr_offset_pos(m_abbrevCollMap.end()) {}
 103
 104 // DWARFDebugAbbrev::Parse()
 105 llvm::Error DWARFDebugAbbrev::parse(const DWARFDataExtractor &data) {
 106   lldb::offset_t offset = 0;
 107
 108   while (data.ValidOffset(offset)) {
 109     uint32_t initial_cu_offset = offset;
 110     DWARFAbbreviationDeclarationSet abbrevDeclSet;
 111
 112     llvm::Error error = abbrevDeclSet.extract(data, &offset);
 113     if (error)
 114       return error;
 115
 116     m_abbrevCollMap[initial_cu_offset] = abbrevDeclSet;
 117   }
 118   m_prev_abbr_offset_pos = m_abbrevCollMap.end();
 119   return llvm::ErrorSuccess();
 120 }
 121
 122 // DWARFDebugAbbrev::GetAbbreviationDeclarationSet()
 123 const DWARFAbbreviationDeclarationSet *
 124 DWARFDebugAbbrev::GetAbbreviationDeclarationSet(
 125     dw_offset_t cu_abbr_offset) const {
 126   DWARFAbbreviationDeclarationCollMapConstIter end = m_abbrevCollMap.end();
 127   DWARFAbbreviationDeclarationCollMapConstIter pos;
 128   if (m_prev_abbr_offset_pos != end &&
 129       m_prev_abbr_offset_pos->first == cu_abbr_offset)
 130     return &(m_prev_abbr_offset_pos->second);
 131   else {
 132     pos = m_abbrevCollMap.find(cu_abbr_offset);
 133     m_prev_abbr_offset_pos = pos;
 134   }
 135
 136   if (pos != m_abbrevCollMap.end())
 137     return &(pos->second);
 138   return nullptr;
 139 }
 140
 141 // DWARFDebugAbbrev::GetUnsupportedForms()
 142 void DWARFDebugAbbrev::GetUnsupportedForms(
 143     std::set<dw_form_t> &invalid_forms) const {
 144   for (const auto &pair : m_abbrevCollMap)
 145     pair.second.GetUnsupportedForms(invalid_forms);
 146 }