1 //===-- DebugNamesDWARFIndex.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/DebugNamesDWARFIndex.h"
10 #include "Plugins/SymbolFile/DWARF/DWARFDebugInfo.h"
11 #include "Plugins/SymbolFile/DWARF/DWARFDeclContext.h"
12 #include "Plugins/SymbolFile/DWARF/SymbolFileDWARFDwo.h"
13 #include "lldb/Core/Module.h"
14 #include "lldb/Utility/RegularExpression.h"
15 #include "lldb/Utility/Stream.h"
16 #include <optional>
17 
18 using namespace lldb_private;
19 using namespace lldb;
20 using namespace lldb_private::dwarf;
21 
22 llvm::Expected<std::unique_ptr<DebugNamesDWARFIndex>>
Create(Module & module,DWARFDataExtractor debug_names,DWARFDataExtractor debug_str,SymbolFileDWARF & dwarf)23 DebugNamesDWARFIndex::Create(Module &module, DWARFDataExtractor debug_names,
24                              DWARFDataExtractor debug_str,
25                              SymbolFileDWARF &dwarf) {
26   auto index_up = std::make_unique<DebugNames>(debug_names.GetAsLLVM(),
27                                                 debug_str.GetAsLLVM());
28   if (llvm::Error E = index_up->extract())
29     return std::move(E);
30 
31   return std::unique_ptr<DebugNamesDWARFIndex>(new DebugNamesDWARFIndex(
32       module, std::move(index_up), debug_names, debug_str, dwarf));
33 }
34 
35 llvm::DenseSet<dw_offset_t>
GetUnits(const DebugNames & debug_names)36 DebugNamesDWARFIndex::GetUnits(const DebugNames &debug_names) {
37   llvm::DenseSet<dw_offset_t> result;
38   for (const DebugNames::NameIndex &ni : debug_names) {
39     for (uint32_t cu = 0; cu < ni.getCUCount(); ++cu)
40       result.insert(ni.getCUOffset(cu));
41   }
42   return result;
43 }
44 
45 std::optional<DIERef>
ToDIERef(const DebugNames::Entry & entry)46 DebugNamesDWARFIndex::ToDIERef(const DebugNames::Entry &entry) {
47   std::optional<uint64_t> cu_offset = entry.getCUOffset();
48   if (!cu_offset)
49     return std::nullopt;
50 
51   DWARFUnit *cu = m_debug_info.GetUnitAtOffset(DIERef::Section::DebugInfo, *cu_offset);
52   if (!cu)
53     return std::nullopt;
54 
55   cu = &cu->GetNonSkeletonUnit();
56   if (std::optional<uint64_t> die_offset = entry.getDIEUnitOffset())
57     return DIERef(cu->GetSymbolFileDWARF().GetDwoNum(),
58                   DIERef::Section::DebugInfo, cu->GetOffset() + *die_offset);
59 
60   return std::nullopt;
61 }
62 
ProcessEntry(const DebugNames::Entry & entry,llvm::function_ref<bool (DWARFDIE die)> callback,llvm::StringRef name)63 bool DebugNamesDWARFIndex::ProcessEntry(
64     const DebugNames::Entry &entry,
65     llvm::function_ref<bool(DWARFDIE die)> callback, llvm::StringRef name) {
66   std::optional<DIERef> ref = ToDIERef(entry);
67   if (!ref)
68     return true;
69   SymbolFileDWARF &dwarf = *llvm::cast<SymbolFileDWARF>(
70       m_module.GetSymbolFile()->GetBackingSymbolFile());
71   DWARFDIE die = dwarf.GetDIE(*ref);
72   if (!die)
73     return true;
74   return callback(die);
75 }
76 
MaybeLogLookupError(llvm::Error error,const DebugNames::NameIndex & ni,llvm::StringRef name)77 void DebugNamesDWARFIndex::MaybeLogLookupError(llvm::Error error,
78                                                const DebugNames::NameIndex &ni,
79                                                llvm::StringRef name) {
80   // Ignore SentinelErrors, log everything else.
81   LLDB_LOG_ERROR(
82       GetLog(DWARFLog::Lookups),
83       handleErrors(std::move(error), [](const DebugNames::SentinelError &) {}),
84       "Failed to parse index entries for index at {1:x}, name {2}: {0}",
85       ni.getUnitOffset(), name);
86 }
87 
GetGlobalVariables(ConstString basename,llvm::function_ref<bool (DWARFDIE die)> callback)88 void DebugNamesDWARFIndex::GetGlobalVariables(
89     ConstString basename, llvm::function_ref<bool(DWARFDIE die)> callback) {
90   for (const DebugNames::Entry &entry :
91        m_debug_names_up->equal_range(basename.GetStringRef())) {
92     if (entry.tag() != DW_TAG_variable)
93       continue;
94 
95     if (!ProcessEntry(entry, callback, basename.GetStringRef()))
96       return;
97   }
98 
99   m_fallback.GetGlobalVariables(basename, callback);
100 }
101 
GetGlobalVariables(const RegularExpression & regex,llvm::function_ref<bool (DWARFDIE die)> callback)102 void DebugNamesDWARFIndex::GetGlobalVariables(
103     const RegularExpression &regex,
104     llvm::function_ref<bool(DWARFDIE die)> callback) {
105   for (const DebugNames::NameIndex &ni: *m_debug_names_up) {
106     for (DebugNames::NameTableEntry nte: ni) {
107       if (!regex.Execute(nte.getString()))
108         continue;
109 
110       uint64_t entry_offset = nte.getEntryOffset();
111       llvm::Expected<DebugNames::Entry> entry_or = ni.getEntry(&entry_offset);
112       for (; entry_or; entry_or = ni.getEntry(&entry_offset)) {
113         if (entry_or->tag() != DW_TAG_variable)
114           continue;
115 
116         if (!ProcessEntry(*entry_or, callback,
117                           llvm::StringRef(nte.getString())))
118           return;
119       }
120       MaybeLogLookupError(entry_or.takeError(), ni, nte.getString());
121     }
122   }
123 
124   m_fallback.GetGlobalVariables(regex, callback);
125 }
126 
GetGlobalVariables(DWARFUnit & cu,llvm::function_ref<bool (DWARFDIE die)> callback)127 void DebugNamesDWARFIndex::GetGlobalVariables(
128     DWARFUnit &cu, llvm::function_ref<bool(DWARFDIE die)> callback) {
129   lldbassert(!cu.GetSymbolFileDWARF().GetDwoNum());
130   uint64_t cu_offset = cu.GetOffset();
131   bool found_entry_for_cu = false;
132   for (const DebugNames::NameIndex &ni: *m_debug_names_up) {
133     for (DebugNames::NameTableEntry nte: ni) {
134       uint64_t entry_offset = nte.getEntryOffset();
135       llvm::Expected<DebugNames::Entry> entry_or = ni.getEntry(&entry_offset);
136       for (; entry_or; entry_or = ni.getEntry(&entry_offset)) {
137         if (entry_or->tag() != DW_TAG_variable)
138           continue;
139         if (entry_or->getCUOffset() != cu_offset)
140           continue;
141 
142         found_entry_for_cu = true;
143         if (!ProcessEntry(*entry_or, callback,
144                           llvm::StringRef(nte.getString())))
145           return;
146       }
147       MaybeLogLookupError(entry_or.takeError(), ni, nte.getString());
148     }
149   }
150   // If no name index for that particular CU was found, fallback to
151   // creating the manual index.
152   if (!found_entry_for_cu)
153     m_fallback.GetGlobalVariables(cu, callback);
154 }
155 
GetCompleteObjCClass(ConstString class_name,bool must_be_implementation,llvm::function_ref<bool (DWARFDIE die)> callback)156 void DebugNamesDWARFIndex::GetCompleteObjCClass(
157     ConstString class_name, bool must_be_implementation,
158     llvm::function_ref<bool(DWARFDIE die)> callback) {
159   // Keep a list of incomplete types as fallback for when we don't find the
160   // complete type.
161   DIEArray incomplete_types;
162 
163   for (const DebugNames::Entry &entry :
164        m_debug_names_up->equal_range(class_name.GetStringRef())) {
165     if (entry.tag() != DW_TAG_structure_type &&
166         entry.tag() != DW_TAG_class_type)
167       continue;
168 
169     std::optional<DIERef> ref = ToDIERef(entry);
170     if (!ref)
171       continue;
172 
173     DWARFUnit *cu = m_debug_info.GetUnit(*ref);
174     if (!cu || !cu->Supports_DW_AT_APPLE_objc_complete_type()) {
175       incomplete_types.push_back(*ref);
176       continue;
177     }
178 
179     DWARFDIE die = m_debug_info.GetDIE(*ref);
180     if (!die) {
181       ReportInvalidDIERef(*ref, class_name.GetStringRef());
182       continue;
183     }
184 
185     if (die.GetAttributeValueAsUnsigned(DW_AT_APPLE_objc_complete_type, 0)) {
186       // If we find the complete version we're done.
187       callback(die);
188       return;
189     }
190     incomplete_types.push_back(*ref);
191   }
192 
193   auto dierefcallback = DIERefCallback(callback, class_name.GetStringRef());
194   for (DIERef ref : incomplete_types)
195     if (!dierefcallback(ref))
196       return;
197 
198   m_fallback.GetCompleteObjCClass(class_name, must_be_implementation, callback);
199 }
200 
GetTypes(ConstString name,llvm::function_ref<bool (DWARFDIE die)> callback)201 void DebugNamesDWARFIndex::GetTypes(
202     ConstString name, llvm::function_ref<bool(DWARFDIE die)> callback) {
203   for (const DebugNames::Entry &entry :
204        m_debug_names_up->equal_range(name.GetStringRef())) {
205     if (isType(entry.tag())) {
206       if (!ProcessEntry(entry, callback, name.GetStringRef()))
207         return;
208     }
209   }
210 
211   m_fallback.GetTypes(name, callback);
212 }
213 
GetTypes(const DWARFDeclContext & context,llvm::function_ref<bool (DWARFDIE die)> callback)214 void DebugNamesDWARFIndex::GetTypes(
215     const DWARFDeclContext &context,
216     llvm::function_ref<bool(DWARFDIE die)> callback) {
217   auto name = context[0].name;
218   for (const DebugNames::Entry &entry : m_debug_names_up->equal_range(name)) {
219     if (entry.tag() == context[0].tag) {
220       if (!ProcessEntry(entry, callback, name))
221         return;
222     }
223   }
224 
225   m_fallback.GetTypes(context, callback);
226 }
227 
GetNamespaces(ConstString name,llvm::function_ref<bool (DWARFDIE die)> callback)228 void DebugNamesDWARFIndex::GetNamespaces(
229     ConstString name, llvm::function_ref<bool(DWARFDIE die)> callback) {
230   for (const DebugNames::Entry &entry :
231        m_debug_names_up->equal_range(name.GetStringRef())) {
232     if (entry.tag() == DW_TAG_namespace) {
233       if (!ProcessEntry(entry, callback, name.GetStringRef()))
234         return;
235     }
236   }
237 
238   m_fallback.GetNamespaces(name, callback);
239 }
240 
GetFunctions(const Module::LookupInfo & lookup_info,SymbolFileDWARF & dwarf,const CompilerDeclContext & parent_decl_ctx,llvm::function_ref<bool (DWARFDIE die)> callback)241 void DebugNamesDWARFIndex::GetFunctions(
242     const Module::LookupInfo &lookup_info, SymbolFileDWARF &dwarf,
243     const CompilerDeclContext &parent_decl_ctx,
244     llvm::function_ref<bool(DWARFDIE die)> callback) {
245   ConstString name = lookup_info.GetLookupName();
246   std::set<DWARFDebugInfoEntry *> seen;
247   for (const DebugNames::Entry &entry :
248        m_debug_names_up->equal_range(name.GetStringRef())) {
249     Tag tag = entry.tag();
250     if (tag != DW_TAG_subprogram && tag != DW_TAG_inlined_subroutine)
251       continue;
252 
253     if (std::optional<DIERef> ref = ToDIERef(entry)) {
254       if (!ProcessFunctionDIE(lookup_info, *ref, dwarf, parent_decl_ctx,
255                               [&](DWARFDIE die) {
256                                 if (!seen.insert(die.GetDIE()).second)
257                                   return true;
258                                 return callback(die);
259                               }))
260         return;
261     }
262   }
263 
264   m_fallback.GetFunctions(lookup_info, dwarf, parent_decl_ctx, callback);
265 }
266 
GetFunctions(const RegularExpression & regex,llvm::function_ref<bool (DWARFDIE die)> callback)267 void DebugNamesDWARFIndex::GetFunctions(
268     const RegularExpression &regex,
269     llvm::function_ref<bool(DWARFDIE die)> callback) {
270   for (const DebugNames::NameIndex &ni: *m_debug_names_up) {
271     for (DebugNames::NameTableEntry nte: ni) {
272       if (!regex.Execute(nte.getString()))
273         continue;
274 
275       uint64_t entry_offset = nte.getEntryOffset();
276       llvm::Expected<DebugNames::Entry> entry_or = ni.getEntry(&entry_offset);
277       for (; entry_or; entry_or = ni.getEntry(&entry_offset)) {
278         Tag tag = entry_or->tag();
279         if (tag != DW_TAG_subprogram && tag != DW_TAG_inlined_subroutine)
280           continue;
281 
282         if (!ProcessEntry(*entry_or, callback,
283                           llvm::StringRef(nte.getString())))
284           return;
285       }
286       MaybeLogLookupError(entry_or.takeError(), ni, nte.getString());
287     }
288   }
289 
290   m_fallback.GetFunctions(regex, callback);
291 }
292 
Dump(Stream & s)293 void DebugNamesDWARFIndex::Dump(Stream &s) {
294   m_fallback.Dump(s);
295 
296   std::string data;
297   llvm::raw_string_ostream os(data);
298   m_debug_names_up->dump(os);
299   s.PutCString(os.str());
300 }
301