lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugMacro.cpp

   1 //===-- DWARFDebugMacro.cpp -----------------------------------------------===//
   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 "DWARFDebugMacro.h"
  10 #include "SymbolFileDWARF.h"
  11
  12 #include "lldb/Symbol/DebugMacros.h"
  13
  14 #include "DWARFDataExtractor.h"
  15
  16 using namespace lldb_private;
  17 using namespace lldb_private::dwarf;
  18 using namespace lldb_private::plugin::dwarf;
  19
  20 DWARFDebugMacroHeader
  21 DWARFDebugMacroHeader::ParseHeader(const DWARFDataExtractor &debug_macro_data,
  22                                    lldb::offset_t *offset) {
  23   DWARFDebugMacroHeader header;
  24
  25   // Skip over the version field in header.
  26   header.m_version = debug_macro_data.GetU16(offset);
  27
  28   uint8_t flags = debug_macro_data.GetU8(offset);
  29   header.m_offset_is_64_bit = (flags & OFFSET_SIZE_MASK) != 0;
  30
  31   if (flags & DEBUG_LINE_OFFSET_MASK) {
  32     if (header.m_offset_is_64_bit)
  33       header.m_debug_line_offset = debug_macro_data.GetU64(offset);
  34     else
  35       header.m_debug_line_offset = debug_macro_data.GetU32(offset);
  36   }
  37
  38   // Skip over the operands table if it is present.
  39   if (flags & OPCODE_OPERANDS_TABLE_MASK)
  40     SkipOperandTable(debug_macro_data, offset);
  41
  42   return header;
  43 }
  44
  45 void DWARFDebugMacroHeader::SkipOperandTable(
  46     const DWARFDataExtractor &debug_macro_data, lldb::offset_t *offset) {
  47   uint8_t entry_count = debug_macro_data.GetU8(offset);
  48   for (uint8_t i = 0; i < entry_count; i++) {
  49     // Skip over the opcode number.
  50     debug_macro_data.GetU8(offset);
  51
  52     uint64_t operand_count = debug_macro_data.GetULEB128(offset);
  53
  54     for (uint64_t j = 0; j < operand_count; j++) {
  55       // Skip over the operand form
  56       debug_macro_data.GetU8(offset);
  57     }
  58   }
  59 }
  60
  61 void DWARFDebugMacroEntry::ReadMacroEntries(
  62     const DWARFDataExtractor &debug_macro_data,
  63     const DWARFDataExtractor &debug_str_data, const bool offset_is_64_bit,
  64     lldb::offset_t *offset, SymbolFileDWARF *sym_file_dwarf,
  65     DebugMacrosSP &debug_macros_sp) {
  66   llvm::dwarf::MacroEntryType type =
  67       static_cast<llvm::dwarf::MacroEntryType>(debug_macro_data.GetU8(offset));
  68   while (type != 0) {
  69     lldb::offset_t new_offset = 0, str_offset = 0;
  70     uint32_t line = 0;
  71     const char *macro_str = nullptr;
  72     uint32_t debug_line_file_idx = 0;
  73
  74     switch (type) {
  75     case DW_MACRO_define:
  76     case DW_MACRO_undef:
  77       line = debug_macro_data.GetULEB128(offset);
  78       macro_str = debug_macro_data.GetCStr(offset);
  79       if (type == DW_MACRO_define)
  80         debug_macros_sp->AddMacroEntry(
  81             DebugMacroEntry::CreateDefineEntry(line, macro_str));
  82       else
  83         debug_macros_sp->AddMacroEntry(
  84             DebugMacroEntry::CreateUndefEntry(line, macro_str));
  85       break;
  86     case DW_MACRO_define_strp:
  87     case DW_MACRO_undef_strp:
  88       line = debug_macro_data.GetULEB128(offset);
  89       if (offset_is_64_bit)
  90         str_offset = debug_macro_data.GetU64(offset);
  91       else
  92         str_offset = debug_macro_data.GetU32(offset);
  93       macro_str = debug_str_data.GetCStr(&str_offset);
  94       if (type == DW_MACRO_define_strp)
  95         debug_macros_sp->AddMacroEntry(
  96             DebugMacroEntry::CreateDefineEntry(line, macro_str));
  97       else
  98         debug_macros_sp->AddMacroEntry(
  99             DebugMacroEntry::CreateUndefEntry(line, macro_str));
 100       break;
 101     case DW_MACRO_start_file:
 102       line = debug_macro_data.GetULEB128(offset);
 103       debug_line_file_idx = debug_macro_data.GetULEB128(offset);
 104       debug_macros_sp->AddMacroEntry(
 105           DebugMacroEntry::CreateStartFileEntry(line, debug_line_file_idx));
 106       break;
 107     case DW_MACRO_end_file:
 108       // This operation has no operands.
 109       debug_macros_sp->AddMacroEntry(DebugMacroEntry::CreateEndFileEntry());
 110       break;
 111     case DW_MACRO_import:
 112       if (offset_is_64_bit)
 113         new_offset = debug_macro_data.GetU64(offset);
 114       else
 115         new_offset = debug_macro_data.GetU32(offset);
 116       debug_macros_sp->AddMacroEntry(DebugMacroEntry::CreateIndirectEntry(
 117           sym_file_dwarf->ParseDebugMacros(&new_offset)));
 118       break;
 119     default:
 120       // TODO: Add support for other standard operations.
 121       // TODO: Provide mechanism to hook handling of non-standard/extension
 122       // operands.
 123       return;
 124     }
 125     type = static_cast<llvm::dwarf::MacroEntryType>(
 126         debug_macro_data.GetU8(offset));
 127   }
 128 }