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