1 //===-- DWARFIndex.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 "Plugins/SymbolFile/DWARF/DWARFIndex.h"
10 #include "DWARFDebugInfoEntry.h"
11 #include "DWARFDeclContext.h"
12 #include "Plugins/Language/ObjC/ObjCLanguage.h"
13 #include "Plugins/SymbolFile/DWARF/DWARFDIE.h"
14 #include "Plugins/SymbolFile/DWARF/SymbolFileDWARF.h"
15 
16 #include "lldb/Core/Mangled.h"
17 #include "lldb/Core/Module.h"
18 #include "lldb/Target/Language.h"
19 
20 using namespace lldb_private;
21 using namespace lldb;
22 using namespace lldb_private::plugin::dwarf;
23 
24 DWARFIndex::~DWARFIndex() = default;
25 
26 bool DWARFIndex::ProcessFunctionDIE(
27     const Module::LookupInfo &lookup_info, DIERef ref, SymbolFileDWARF &dwarf,
28     const CompilerDeclContext &parent_decl_ctx,
29     llvm::function_ref<bool(DWARFDIE die)> callback) {
30   llvm::StringRef name = lookup_info.GetLookupName().GetStringRef();
31   FunctionNameType name_type_mask = lookup_info.GetNameTypeMask();
32   DWARFDIE die = dwarf.GetDIE(ref);
33   if (!die) {
34     ReportInvalidDIERef(ref, name);
35     return true;
36   }
37 
38   if (!(name_type_mask & eFunctionNameTypeFull)) {
39     ConstString name_to_match_against;
40     if (const char *mangled_die_name = die.GetMangledName()) {
41       name_to_match_against = ConstString(mangled_die_name);
42     } else {
43       SymbolFileDWARF *symbols = die.GetDWARF();
44       if (ConstString demangled_die_name =
45               symbols->ConstructFunctionDemangledName(die))
46         name_to_match_against = demangled_die_name;
47     }
48 
49     if (!lookup_info.NameMatchesLookupInfo(name_to_match_against,
50                                            lookup_info.GetLanguageType()))
51       return true;
52   }
53 
54   // Exit early if we're searching exclusively for methods or selectors and
55   // we have a context specified (no methods in namespaces).
56   uint32_t looking_for_nonmethods =
57       name_type_mask & ~(eFunctionNameTypeMethod | eFunctionNameTypeSelector);
58   if (!looking_for_nonmethods && parent_decl_ctx.IsValid())
59     return true;
60 
61   // Otherwise, we need to also check that the context matches. If it does not
62   // match, we do nothing.
63   if (!SymbolFileDWARF::DIEInDeclContext(parent_decl_ctx, die))
64     return true;
65 
66   // In case of a full match, we just insert everything we find.
67   if (name_type_mask & eFunctionNameTypeFull && die.GetMangledName() == name)
68     return callback(die);
69 
70   // If looking for ObjC selectors, we need to also check if the name is a
71   // possible selector.
72   if (name_type_mask & eFunctionNameTypeSelector &&
73       ObjCLanguage::IsPossibleObjCMethodName(die.GetName()))
74     return callback(die);
75 
76   bool looking_for_methods = name_type_mask & lldb::eFunctionNameTypeMethod;
77   bool looking_for_functions = name_type_mask & lldb::eFunctionNameTypeBase;
78   if (looking_for_methods || looking_for_functions) {
79     // If we're looking for either methods or functions, we definitely want this
80     // die. Otherwise, only keep it if the die type matches what we are
81     // searching for.
82     if ((looking_for_methods && looking_for_functions) ||
83         looking_for_methods == die.IsMethod())
84       return callback(die);
85   }
86 
87   return true;
88 }
89 
90 DWARFIndex::DIERefCallbackImpl::DIERefCallbackImpl(
91     const DWARFIndex &index, llvm::function_ref<bool(DWARFDIE die)> callback,
92     llvm::StringRef name)
93     : m_index(index),
94       m_dwarf(*llvm::cast<SymbolFileDWARF>(
95           index.m_module.GetSymbolFile()->GetBackingSymbolFile())),
96       m_callback(callback), m_name(name) {}
97 
98 bool DWARFIndex::DIERefCallbackImpl::operator()(DIERef ref) const {
99   if (DWARFDIE die = m_dwarf.GetDIE(ref))
100     return m_callback(die);
101   m_index.ReportInvalidDIERef(ref, m_name);
102   return true;
103 }
104 
105 bool DWARFIndex::DIERefCallbackImpl::operator()(
106     const llvm::AppleAcceleratorTable::Entry &entry) const {
107   return this->operator()(DIERef(std::nullopt, DIERef::Section::DebugInfo,
108                                  *entry.getDIESectionOffset()));
109 }
110 
111 void DWARFIndex::ReportInvalidDIERef(DIERef ref, llvm::StringRef name) const {
112   m_module.ReportErrorIfModifyDetected(
113       "the DWARF debug information has been modified (accelerator table had "
114       "bad die {0:x16} for '{1}')\n",
115       ref.die_offset(), name.str().c_str());
116 }
117 
118 void DWARFIndex::GetFullyQualifiedType(
119     const DWARFDeclContext &context,
120     llvm::function_ref<bool(DWARFDIE die)> callback) {
121   GetTypes(context, [&](DWARFDIE die) {
122     return GetFullyQualifiedTypeImpl(context, die, callback);
123   });
124 }
125 
126 bool DWARFIndex::GetFullyQualifiedTypeImpl(
127     const DWARFDeclContext &context, DWARFDIE die,
128     llvm::function_ref<bool(DWARFDIE die)> callback) {
129   DWARFDeclContext dwarf_decl_ctx =
130       die.GetDIE()->GetDWARFDeclContext(die.GetCU());
131   if (dwarf_decl_ctx == context)
132     return callback(die);
133   return true;
134 }
135