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 }
92