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

   1 //===-- DWARFASTParser.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 "DWARFASTParser.h"
  10 #include "DWARFAttribute.h"
  11 #include "DWARFDIE.h"
  12 #include "SymbolFileDWARF.h"
  13
  14 #include "lldb/Symbol/SymbolFile.h"
  15 #include "lldb/Target/StackFrame.h"
  16 #include "lldb/ValueObject/ValueObject.h"
  17 #include <optional>
  18
  19 using namespace lldb;
  20 using namespace lldb_private;
  21 using namespace lldb_private::dwarf;
  22 using namespace lldb_private::plugin::dwarf;
  23
  24 std::optional<SymbolFile::ArrayInfo>
  25 DWARFASTParser::ParseChildArrayInfo(const DWARFDIE &parent_die,
  26                                     const ExecutionContext *exe_ctx) {
  27   SymbolFile::ArrayInfo array_info;
  28   if (!parent_die)
  29     return std::nullopt;
  30
  31   for (DWARFDIE die : parent_die.children()) {
  32     const dw_tag_t tag = die.Tag();
  33     if (tag != DW_TAG_subrange_type)
  34       continue;
  35
  36     DWARFAttributes attributes = die.GetAttributes();
  37     if (attributes.Size() == 0)
  38       continue;
  39
  40     std::optional<uint64_t> num_elements;
  41     uint64_t lower_bound = 0;
  42     uint64_t upper_bound = 0;
  43     bool upper_bound_valid = false;
  44     for (size_t i = 0; i < attributes.Size(); ++i) {
  45       const dw_attr_t attr = attributes.AttributeAtIndex(i);
  46       DWARFFormValue form_value;
  47       if (attributes.ExtractFormValueAtIndex(i, form_value)) {
  48         switch (attr) {
  49         case DW_AT_name:
  50           break;
  51
  52         case DW_AT_count:
  53           if (DWARFDIE var_die = die.GetReferencedDIE(DW_AT_count)) {
  54             if (var_die.Tag() == DW_TAG_variable)
  55               if (exe_ctx) {
  56                 if (auto frame = exe_ctx->GetFrameSP()) {
  57                   Status error;
  58                   lldb::VariableSP var_sp;
  59                   auto valobj_sp = frame->GetValueForVariableExpressionPath(
  60                       var_die.GetName(), eNoDynamicValues, 0, var_sp, error);
  61                   if (valobj_sp) {
  62                     num_elements = valobj_sp->GetValueAsUnsigned(0);
  63                     break;
  64                   }
  65                 }
  66               }
  67           } else
  68             num_elements = form_value.Unsigned();
  69           break;
  70
  71         case DW_AT_bit_stride:
  72           array_info.bit_stride = form_value.Unsigned();
  73           break;
  74
  75         case DW_AT_byte_stride:
  76           array_info.byte_stride = form_value.Unsigned();
  77           break;
  78
  79         case DW_AT_lower_bound:
  80           lower_bound = form_value.Unsigned();
  81           break;
  82
  83         case DW_AT_upper_bound:
  84           upper_bound_valid = true;
  85           upper_bound = form_value.Unsigned();
  86           break;
  87
  88         default:
  89           break;
  90         }
  91       }
  92     }
  93
  94     if (!num_elements || *num_elements == 0) {
  95       if (upper_bound_valid && upper_bound >= lower_bound)
  96         num_elements = upper_bound - lower_bound + 1;
  97     }
  98
  99     array_info.element_orders.push_back(num_elements);
 100   }
 101   return array_info;
 102 }
 103
 104 Type *DWARFASTParser::GetTypeForDIE(const DWARFDIE &die) {
 105   if (!die)
 106     return nullptr;
 107
 108   SymbolFileDWARF *dwarf = die.GetDWARF();
 109   if (!dwarf)
 110     return nullptr;
 111
 112   DWARFAttributes attributes = die.GetAttributes();
 113   if (attributes.Size() == 0)
 114     return nullptr;
 115
 116   DWARFFormValue type_die_form;
 117   for (size_t i = 0; i < attributes.Size(); ++i) {
 118     dw_attr_t attr = attributes.AttributeAtIndex(i);
 119     DWARFFormValue form_value;
 120
 121     if (attr == DW_AT_type && attributes.ExtractFormValueAtIndex(i, form_value))
 122       return dwarf->ResolveTypeUID(form_value.Reference(), true);
 123   }
 124
 125   return nullptr;
 126 }
 127
 128 AccessType
 129 DWARFASTParser::GetAccessTypeFromDWARF(uint32_t dwarf_accessibility) {
 130   switch (dwarf_accessibility) {
 131   case DW_ACCESS_public:
 132     return eAccessPublic;
 133   case DW_ACCESS_private:
 134     return eAccessPrivate;
 135   case DW_ACCESS_protected:
 136     return eAccessProtected;
 137   default:
 138     break;
 139   }
 140   return eAccessNone;
 141 }