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

   1 //===-- DWARFCompileUnit.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 "DWARFCompileUnit.h"
  11
  12 #include "SymbolFileDWARF.h"
  13 #include "lldb/Utility/Stream.h"
  14
  15 using namespace lldb;
  16 using namespace lldb_private;
  17
  18 extern int g_verbose;
  19
  20 DWARFCompileUnit::DWARFCompileUnit(SymbolFileDWARF *dwarf2Data)
  21     : DWARFUnit(dwarf2Data) {}
  22
  23 DWARFUnitSP DWARFCompileUnit::Extract(SymbolFileDWARF *dwarf2Data,
  24                                       const DWARFDataExtractor &debug_info,
  25                                       lldb::offset_t *offset_ptr) {
  26   // std::make_shared would require the ctor to be public.
  27   std::shared_ptr<DWARFCompileUnit> cu_sp(new DWARFCompileUnit(dwarf2Data));
  28
  29   cu_sp->m_offset = *offset_ptr;
  30
  31   if (debug_info.ValidOffset(*offset_ptr)) {
  32     dw_offset_t abbr_offset;
  33     const DWARFDebugAbbrev *abbr = dwarf2Data->DebugAbbrev();
  34     cu_sp->m_length = debug_info.GetDWARFInitialLength(offset_ptr);
  35     cu_sp->m_is_dwarf64 = debug_info.IsDWARF64();
  36     cu_sp->m_version = debug_info.GetU16(offset_ptr);
  37
  38     if (cu_sp->m_version == 5) {
  39       cu_sp->m_unit_type = debug_info.GetU8(offset_ptr);
  40       cu_sp->m_addr_size = debug_info.GetU8(offset_ptr);
  41       abbr_offset = debug_info.GetDWARFOffset(offset_ptr);
  42
  43       if (cu_sp->m_unit_type == llvm::dwarf::DW_UT_skeleton)
  44         cu_sp->m_dwo_id = debug_info.GetU64(offset_ptr);
  45     } else {
  46       abbr_offset = debug_info.GetDWARFOffset(offset_ptr);
  47       cu_sp->m_addr_size = debug_info.GetU8(offset_ptr);
  48     }
  49
  50     bool length_OK =
  51         debug_info.ValidOffset(cu_sp->GetNextCompileUnitOffset() - 1);
  52     bool version_OK = SymbolFileDWARF::SupportedVersion(cu_sp->m_version);
  53     bool abbr_offset_OK =
  54         dwarf2Data->get_debug_abbrev_data().ValidOffset(abbr_offset);
  55     bool addr_size_OK = (cu_sp->m_addr_size == 4) || (cu_sp->m_addr_size == 8);
  56
  57     if (length_OK && version_OK && addr_size_OK && abbr_offset_OK &&
  58         abbr != NULL) {
  59       cu_sp->m_abbrevs = abbr->GetAbbreviationDeclarationSet(abbr_offset);
  60       return cu_sp;
  61     }
  62
  63     // reset the offset to where we tried to parse from if anything went wrong
  64     *offset_ptr = cu_sp->m_offset;
  65   }
  66
  67   return nullptr;
  68 }
  69
  70 void DWARFCompileUnit::Dump(Stream *s) const {
  71   s->Printf("0x%8.8x: Compile Unit: length = 0x%8.8x, version = 0x%4.4x, "
  72             "abbr_offset = 0x%8.8x, addr_size = 0x%2.2x (next CU at "
  73             "{0x%8.8x})\n",
  74             m_offset, m_length, m_version, GetAbbrevOffset(), m_addr_size,
  75             GetNextCompileUnitOffset());
  76 }
  77
  78 uint32_t DWARFCompileUnit::GetHeaderByteSize() const {
  79   if (m_version < 5)
  80     return m_is_dwarf64 ? 23 : 11;
  81
  82   switch (m_unit_type) {
  83   case llvm::dwarf::DW_UT_compile:
  84   case llvm::dwarf::DW_UT_partial:
  85     return 12;
  86   case llvm::dwarf::DW_UT_skeleton:
  87   case llvm::dwarf::DW_UT_split_compile:
  88     return 20;
  89   case llvm::dwarf::DW_UT_type:
  90   case llvm::dwarf::DW_UT_split_type:
  91     return 24;
  92   }
  93   llvm_unreachable("invalid UnitType.");
  94 }
  95
  96 const lldb_private::DWARFDataExtractor &DWARFCompileUnit::GetData() const {
  97   return m_dwarf->get_debug_info_data();
  98 }