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
12using namespace lldb_private::dwarf;
13using 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}".
17static 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
31const 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
58bool 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}
92