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

   1 //===-- DWARFDeclContext.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 "DWARFDeclContext.h"
  10 #include "llvm/Support/raw_ostream.h"
  11
  12 using namespace lldb_private::dwarf;
  13 using namespace lldb_private::plugin::dwarf;
  14
  15 /// Returns the name of `entry` if it has one, or the appropriate "anonymous
  16 /// {namespace, class, struct, union}".
  17 static const char *GetName(DWARFDeclContext::Entry entry) {
  18   if (entry.name != nullptr)
  19     return entry.name;
  20   if (entry.tag == DW_TAG_namespace)
  21     return "(anonymous namespace)";
  22   if (entry.tag == DW_TAG_class_type)
  23     return "(anonymous class)";
  24   if (entry.tag == DW_TAG_structure_type)
  25     return "(anonymous struct)";
  26   if (entry.tag == DW_TAG_union_type)
  27     return "(anonymous union)";
  28   return "(anonymous)";
  29 }
  30
  31 const char *DWARFDeclContext::GetQualifiedName() const {
  32   if (m_qualified_name.empty()) {
  33     // The declaration context array for a class named "foo" in namespace
  34     // "a::b::c" will be something like:
  35     //  [0] DW_TAG_class_type "foo"
  36     //  [1] DW_TAG_namespace "c"
  37     //  [2] DW_TAG_namespace "b"
  38     //  [3] DW_TAG_namespace "a"
  39     if (!m_entries.empty()) {
  40       if (m_entries.size() == 1) {
  41         if (m_entries[0].name) {
  42           m_qualified_name.append("::");
  43           m_qualified_name.append(m_entries[0].name);
  44         }
  45       } else {
  46         llvm::raw_string_ostream string_stream(m_qualified_name);
  47         llvm::interleave(
  48             llvm::reverse(m_entries), string_stream,
  49             [&](auto entry) { string_stream << GetName(entry); }, "::");
  50       }
  51     }
  52   }
  53   if (m_qualified_name.empty())
  54     return nullptr;
  55   return m_qualified_name.c_str();
  56 }
  57
  58 bool DWARFDeclContext::operator==(const DWARFDeclContext &rhs) const {
  59   if (m_entries.size() != rhs.m_entries.size())
  60     return false;
  61
  62   collection::const_iterator pos;
  63   collection::const_iterator begin = m_entries.begin();
  64   collection::const_iterator end = m_entries.end();
  65
  66   collection::const_iterator rhs_pos;
  67   collection::const_iterator rhs_begin = rhs.m_entries.begin();
  68   // The two entry arrays have the same size
  69
  70   // First compare the tags before we do expensive name compares
  71   for (pos = begin, rhs_pos = rhs_begin; pos != end; ++pos, ++rhs_pos) {
  72     if (pos->tag != rhs_pos->tag) {
  73       // Check for DW_TAG_structure_type and DW_TAG_class_type as they are
  74       // often used interchangeably in GCC
  75       if (pos->tag == DW_TAG_structure_type &&
  76           rhs_pos->tag == DW_TAG_class_type)
  77         continue;
  78       if (pos->tag == DW_TAG_class_type &&
  79           rhs_pos->tag == DW_TAG_structure_type)
  80         continue;
  81       return false;
  82     }
  83   }
  84   // The tags all match, now compare the names
  85   for (pos = begin, rhs_pos = rhs_begin; pos != end; ++pos, ++rhs_pos) {
  86     if (!pos->NameMatches(*rhs_pos))
  87       return false;
  88   }
  89   // All tags and names match
  90   return true;
  91 }