1 //===-- ObjCLanguageRuntime.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 #include "clang/AST/Type.h"
9
10 #include "ObjCLanguageRuntime.h"
11
12 #include "Plugins/TypeSystem/Clang/TypeSystemClang.h"
13 #include "lldb/Core/MappedHash.h"
14 #include "lldb/Core/Module.h"
15 #include "lldb/Core/PluginManager.h"
16 #include "lldb/Core/ValueObject.h"
17 #include "lldb/Symbol/SymbolContext.h"
18 #include "lldb/Symbol/SymbolFile.h"
19 #include "lldb/Symbol/Type.h"
20 #include "lldb/Symbol/TypeList.h"
21 #include "lldb/Symbol/Variable.h"
22 #include "lldb/Target/ABI.h"
23 #include "lldb/Target/Target.h"
24 #include "lldb/Utility/LLDBLog.h"
25 #include "lldb/Utility/Log.h"
26 #include "lldb/Utility/Timer.h"
27
28 #include "llvm/ADT/StringRef.h"
29 #include "llvm/Support/DJB.h"
30
31 using namespace lldb;
32 using namespace lldb_private;
33
34 char ObjCLanguageRuntime::ID = 0;
35
36 // Destructor
37 ObjCLanguageRuntime::~ObjCLanguageRuntime() = default;
38
ObjCLanguageRuntime(Process * process)39 ObjCLanguageRuntime::ObjCLanguageRuntime(Process *process)
40 : LanguageRuntime(process), m_impl_cache(), m_impl_str_cache(),
41 m_has_new_literals_and_indexing(eLazyBoolCalculate),
42 m_isa_to_descriptor(), m_hash_to_isa_map(), m_type_size_cache(),
43 m_isa_to_descriptor_stop_id(UINT32_MAX), m_complete_class_cache(),
44 m_negative_complete_class_cache() {}
45
IsAllowedRuntimeValue(ConstString name)46 bool ObjCLanguageRuntime::IsAllowedRuntimeValue(ConstString name) {
47 static ConstString g_self = ConstString("self");
48 static ConstString g_cmd = ConstString("_cmd");
49 return name == g_self || name == g_cmd;
50 }
51
AddClass(ObjCISA isa,const ClassDescriptorSP & descriptor_sp,const char * class_name)52 bool ObjCLanguageRuntime::AddClass(ObjCISA isa,
53 const ClassDescriptorSP &descriptor_sp,
54 const char *class_name) {
55 if (isa != 0) {
56 m_isa_to_descriptor[isa] = descriptor_sp;
57 // class_name is assumed to be valid
58 m_hash_to_isa_map.insert(std::make_pair(llvm::djbHash(class_name), isa));
59 return true;
60 }
61 return false;
62 }
63
AddToMethodCache(lldb::addr_t class_addr,lldb::addr_t selector,lldb::addr_t impl_addr)64 void ObjCLanguageRuntime::AddToMethodCache(lldb::addr_t class_addr,
65 lldb::addr_t selector,
66 lldb::addr_t impl_addr) {
67 Log *log = GetLog(LLDBLog::Step);
68 if (log) {
69 LLDB_LOGF(log,
70 "Caching: class 0x%" PRIx64 " selector 0x%" PRIx64
71 " implementation 0x%" PRIx64 ".",
72 class_addr, selector, impl_addr);
73 }
74 m_impl_cache.insert(std::pair<ClassAndSel, lldb::addr_t>(
75 ClassAndSel(class_addr, selector), impl_addr));
76 }
77
AddToMethodCache(lldb::addr_t class_addr,llvm::StringRef sel_str,lldb::addr_t impl_addr)78 void ObjCLanguageRuntime::AddToMethodCache(lldb::addr_t class_addr,
79 llvm::StringRef sel_str,
80 lldb::addr_t impl_addr) {
81 Log *log = GetLog(LLDBLog::Step);
82
83 LLDB_LOG(log, "Caching: class {0} selector {1} implementation {2}.",
84 class_addr, sel_str, impl_addr);
85
86 m_impl_str_cache.insert(std::pair<ClassAndSelStr, lldb::addr_t>(
87 ClassAndSelStr(class_addr, sel_str), impl_addr));
88 }
89
LookupInMethodCache(lldb::addr_t class_addr,lldb::addr_t selector)90 lldb::addr_t ObjCLanguageRuntime::LookupInMethodCache(lldb::addr_t class_addr,
91 lldb::addr_t selector) {
92 MsgImplMap::iterator pos, end = m_impl_cache.end();
93 pos = m_impl_cache.find(ClassAndSel(class_addr, selector));
94 if (pos != end)
95 return (*pos).second;
96 return LLDB_INVALID_ADDRESS;
97 }
98
LookupInMethodCache(lldb::addr_t class_addr,llvm::StringRef sel_str)99 lldb::addr_t ObjCLanguageRuntime::LookupInMethodCache(lldb::addr_t class_addr,
100 llvm::StringRef sel_str) {
101 MsgImplStrMap::iterator pos, end = m_impl_str_cache.end();
102 pos = m_impl_str_cache.find(ClassAndSelStr(class_addr, sel_str));
103 if (pos != end)
104 return (*pos).second;
105 return LLDB_INVALID_ADDRESS;
106 }
107
108 lldb::TypeSP
LookupInCompleteClassCache(ConstString & name)109 ObjCLanguageRuntime::LookupInCompleteClassCache(ConstString &name) {
110 CompleteClassMap::iterator complete_class_iter =
111 m_complete_class_cache.find(name);
112
113 if (complete_class_iter != m_complete_class_cache.end()) {
114 // Check the weak pointer to make sure the type hasn't been unloaded
115 TypeSP complete_type_sp(complete_class_iter->second.lock());
116
117 if (complete_type_sp)
118 return complete_type_sp;
119 else
120 m_complete_class_cache.erase(name);
121 }
122
123 if (m_negative_complete_class_cache.count(name) > 0)
124 return TypeSP();
125
126 const ModuleList &modules = m_process->GetTarget().GetImages();
127
128 SymbolContextList sc_list;
129 modules.FindSymbolsWithNameAndType(name, eSymbolTypeObjCClass, sc_list);
130 const size_t matching_symbols = sc_list.GetSize();
131
132 if (matching_symbols) {
133 SymbolContext sc;
134
135 sc_list.GetContextAtIndex(0, sc);
136
137 ModuleSP module_sp(sc.module_sp);
138
139 if (!module_sp)
140 return TypeSP();
141
142 const bool exact_match = true;
143 const uint32_t max_matches = UINT32_MAX;
144 TypeList types;
145
146 llvm::DenseSet<SymbolFile *> searched_symbol_files;
147 module_sp->FindTypes(name, exact_match, max_matches, searched_symbol_files,
148 types);
149
150 for (uint32_t i = 0; i < types.GetSize(); ++i) {
151 TypeSP type_sp(types.GetTypeAtIndex(i));
152
153 if (TypeSystemClang::IsObjCObjectOrInterfaceType(
154 type_sp->GetForwardCompilerType())) {
155 if (TypePayloadClang(type_sp->GetPayload()).IsCompleteObjCClass()) {
156 m_complete_class_cache[name] = type_sp;
157 return type_sp;
158 }
159 }
160 }
161 }
162 m_negative_complete_class_cache.insert(name);
163 return TypeSP();
164 }
165
GetByteOffsetForIvar(CompilerType & parent_qual_type,const char * ivar_name)166 size_t ObjCLanguageRuntime::GetByteOffsetForIvar(CompilerType &parent_qual_type,
167 const char *ivar_name) {
168 return LLDB_INVALID_IVAR_OFFSET;
169 }
170
IsPointerValid(lldb::addr_t value,uint32_t ptr_size,bool allow_NULLs,bool allow_tagged,bool check_version_specific) const171 bool ObjCLanguageRuntime::ClassDescriptor::IsPointerValid(
172 lldb::addr_t value, uint32_t ptr_size, bool allow_NULLs, bool allow_tagged,
173 bool check_version_specific) const {
174 if (!value)
175 return allow_NULLs;
176 if ((value % 2) == 1 && allow_tagged)
177 return true;
178 if ((value % ptr_size) == 0)
179 return (check_version_specific ? CheckPointer(value, ptr_size) : true);
180 else
181 return false;
182 }
183
184 ObjCLanguageRuntime::ObjCISA
GetISA(ConstString name)185 ObjCLanguageRuntime::GetISA(ConstString name) {
186 ISAToDescriptorIterator pos = GetDescriptorIterator(name);
187 if (pos != m_isa_to_descriptor.end())
188 return pos->first;
189 return 0;
190 }
191
192 ObjCLanguageRuntime::ISAToDescriptorIterator
GetDescriptorIterator(ConstString name)193 ObjCLanguageRuntime::GetDescriptorIterator(ConstString name) {
194 ISAToDescriptorIterator end = m_isa_to_descriptor.end();
195
196 if (name) {
197 UpdateISAToDescriptorMap();
198 if (m_hash_to_isa_map.empty()) {
199 // No name hashes were provided, we need to just linearly power through
200 // the names and find a match
201 for (ISAToDescriptorIterator pos = m_isa_to_descriptor.begin();
202 pos != end; ++pos) {
203 if (pos->second->GetClassName() == name)
204 return pos;
205 }
206 } else {
207 // Name hashes were provided, so use them to efficiently lookup name to
208 // isa/descriptor
209 const uint32_t name_hash = llvm::djbHash(name.GetStringRef());
210 std::pair<HashToISAIterator, HashToISAIterator> range =
211 m_hash_to_isa_map.equal_range(name_hash);
212 for (HashToISAIterator range_pos = range.first; range_pos != range.second;
213 ++range_pos) {
214 ISAToDescriptorIterator pos =
215 m_isa_to_descriptor.find(range_pos->second);
216 if (pos != m_isa_to_descriptor.end()) {
217 if (pos->second->GetClassName() == name)
218 return pos;
219 }
220 }
221 }
222 }
223 return end;
224 }
225
226 std::pair<ObjCLanguageRuntime::ISAToDescriptorIterator,
227 ObjCLanguageRuntime::ISAToDescriptorIterator>
GetDescriptorIteratorPair(bool update_if_needed)228 ObjCLanguageRuntime::GetDescriptorIteratorPair(bool update_if_needed) {
229 if (update_if_needed)
230 UpdateISAToDescriptorMapIfNeeded();
231
232 return std::pair<ObjCLanguageRuntime::ISAToDescriptorIterator,
233 ObjCLanguageRuntime::ISAToDescriptorIterator>(
234 m_isa_to_descriptor.begin(), m_isa_to_descriptor.end());
235 }
236
237 ObjCLanguageRuntime::ObjCISA
GetParentClass(ObjCLanguageRuntime::ObjCISA isa)238 ObjCLanguageRuntime::GetParentClass(ObjCLanguageRuntime::ObjCISA isa) {
239 ClassDescriptorSP objc_class_sp(GetClassDescriptorFromISA(isa));
240 if (objc_class_sp) {
241 ClassDescriptorSP objc_super_class_sp(objc_class_sp->GetSuperclass());
242 if (objc_super_class_sp)
243 return objc_super_class_sp->GetISA();
244 }
245 return 0;
246 }
247
248 ObjCLanguageRuntime::ClassDescriptorSP
GetClassDescriptorFromClassName(ConstString class_name)249 ObjCLanguageRuntime::GetClassDescriptorFromClassName(
250 ConstString class_name) {
251 ISAToDescriptorIterator pos = GetDescriptorIterator(class_name);
252 if (pos != m_isa_to_descriptor.end())
253 return pos->second;
254 return ClassDescriptorSP();
255 }
256
257 ObjCLanguageRuntime::ClassDescriptorSP
GetClassDescriptor(ValueObject & valobj)258 ObjCLanguageRuntime::GetClassDescriptor(ValueObject &valobj) {
259 ClassDescriptorSP objc_class_sp;
260 // if we get an invalid VO (which might still happen when playing around with
261 // pointers returned by the expression parser, don't consider this a valid
262 // ObjC object)
263 if (valobj.GetCompilerType().IsValid()) {
264 addr_t isa_pointer = valobj.GetPointerValue();
265 if (isa_pointer != LLDB_INVALID_ADDRESS) {
266 ExecutionContext exe_ctx(valobj.GetExecutionContextRef());
267
268 Process *process = exe_ctx.GetProcessPtr();
269 if (process) {
270 Status error;
271 ObjCISA isa = process->ReadPointerFromMemory(isa_pointer, error);
272 if (isa != LLDB_INVALID_ADDRESS)
273 objc_class_sp = GetClassDescriptorFromISA(isa);
274 }
275 }
276 }
277 return objc_class_sp;
278 }
279
280 ObjCLanguageRuntime::ClassDescriptorSP
GetNonKVOClassDescriptor(ValueObject & valobj)281 ObjCLanguageRuntime::GetNonKVOClassDescriptor(ValueObject &valobj) {
282 ObjCLanguageRuntime::ClassDescriptorSP objc_class_sp(
283 GetClassDescriptor(valobj));
284 if (objc_class_sp) {
285 if (!objc_class_sp->IsKVO())
286 return objc_class_sp;
287
288 ClassDescriptorSP non_kvo_objc_class_sp(objc_class_sp->GetSuperclass());
289 if (non_kvo_objc_class_sp && non_kvo_objc_class_sp->IsValid())
290 return non_kvo_objc_class_sp;
291 }
292 return ClassDescriptorSP();
293 }
294
295 ObjCLanguageRuntime::ClassDescriptorSP
GetClassDescriptorFromISA(ObjCISA isa)296 ObjCLanguageRuntime::GetClassDescriptorFromISA(ObjCISA isa) {
297 if (isa) {
298 UpdateISAToDescriptorMap();
299
300 ObjCLanguageRuntime::ISAToDescriptorIterator pos =
301 m_isa_to_descriptor.find(isa);
302 if (pos != m_isa_to_descriptor.end())
303 return pos->second;
304
305 if (ABISP abi_sp = m_process->GetABI()) {
306 pos = m_isa_to_descriptor.find(abi_sp->FixCodeAddress(isa));
307 if (pos != m_isa_to_descriptor.end())
308 return pos->second;
309 }
310 }
311 return ClassDescriptorSP();
312 }
313
314 ObjCLanguageRuntime::ClassDescriptorSP
GetNonKVOClassDescriptor(ObjCISA isa)315 ObjCLanguageRuntime::GetNonKVOClassDescriptor(ObjCISA isa) {
316 if (isa) {
317 ClassDescriptorSP objc_class_sp = GetClassDescriptorFromISA(isa);
318 if (objc_class_sp && objc_class_sp->IsValid()) {
319 if (!objc_class_sp->IsKVO())
320 return objc_class_sp;
321
322 ClassDescriptorSP non_kvo_objc_class_sp(objc_class_sp->GetSuperclass());
323 if (non_kvo_objc_class_sp && non_kvo_objc_class_sp->IsValid())
324 return non_kvo_objc_class_sp;
325 }
326 }
327 return ClassDescriptorSP();
328 }
329
330 CompilerType
RealizeType(const char * name,bool for_expression)331 ObjCLanguageRuntime::EncodingToType::RealizeType(const char *name,
332 bool for_expression) {
333 if (m_scratch_ast_ctx_up)
334 return RealizeType(*m_scratch_ast_ctx_up, name, for_expression);
335 return CompilerType();
336 }
337
338 ObjCLanguageRuntime::EncodingToType::~EncodingToType() = default;
339
GetEncodingToType()340 ObjCLanguageRuntime::EncodingToTypeSP ObjCLanguageRuntime::GetEncodingToType() {
341 return nullptr;
342 }
343
GetTypeBitSize(const CompilerType & compiler_type,uint64_t & size)344 bool ObjCLanguageRuntime::GetTypeBitSize(const CompilerType &compiler_type,
345 uint64_t &size) {
346 void *opaque_ptr = compiler_type.GetOpaqueQualType();
347 size = m_type_size_cache.Lookup(opaque_ptr);
348 // an ObjC object will at least have an ISA, so 0 is definitely not OK
349 if (size > 0)
350 return true;
351
352 ClassDescriptorSP class_descriptor_sp =
353 GetClassDescriptorFromClassName(compiler_type.GetTypeName());
354 if (!class_descriptor_sp)
355 return false;
356
357 int32_t max_offset = INT32_MIN;
358 uint64_t sizeof_max = 0;
359 bool found = false;
360
361 for (size_t idx = 0; idx < class_descriptor_sp->GetNumIVars(); idx++) {
362 const auto &ivar = class_descriptor_sp->GetIVarAtIndex(idx);
363 int32_t cur_offset = ivar.m_offset;
364 if (cur_offset > max_offset) {
365 max_offset = cur_offset;
366 sizeof_max = ivar.m_size;
367 found = true;
368 }
369 }
370
371 size = 8 * (max_offset + sizeof_max);
372 if (found)
373 m_type_size_cache.Insert(opaque_ptr, size);
374
375 return found;
376 }
377
378 lldb::BreakpointPreconditionSP
GetBreakpointExceptionPrecondition(LanguageType language,bool throw_bp)379 ObjCLanguageRuntime::GetBreakpointExceptionPrecondition(LanguageType language,
380 bool throw_bp) {
381 if (language != eLanguageTypeObjC)
382 return lldb::BreakpointPreconditionSP();
383 if (!throw_bp)
384 return lldb::BreakpointPreconditionSP();
385 BreakpointPreconditionSP precondition_sp(
386 new ObjCLanguageRuntime::ObjCExceptionPrecondition());
387 return precondition_sp;
388 }
389
390 // Exception breakpoint Precondition class for ObjC:
AddClassName(const char * class_name)391 void ObjCLanguageRuntime::ObjCExceptionPrecondition::AddClassName(
392 const char *class_name) {
393 m_class_names.insert(class_name);
394 }
395
396 ObjCLanguageRuntime::ObjCExceptionPrecondition::ObjCExceptionPrecondition() =
397 default;
398
EvaluatePrecondition(StoppointCallbackContext & context)399 bool ObjCLanguageRuntime::ObjCExceptionPrecondition::EvaluatePrecondition(
400 StoppointCallbackContext &context) {
401 return true;
402 }
403
GetDescription(Stream & stream,lldb::DescriptionLevel level)404 void ObjCLanguageRuntime::ObjCExceptionPrecondition::GetDescription(
405 Stream &stream, lldb::DescriptionLevel level) {}
406
ConfigurePrecondition(Args & args)407 Status ObjCLanguageRuntime::ObjCExceptionPrecondition::ConfigurePrecondition(
408 Args &args) {
409 Status error;
410 if (args.GetArgumentCount() > 0)
411 error.SetErrorString(
412 "The ObjC Exception breakpoint doesn't support extra options.");
413 return error;
414 }
415
416 llvm::Optional<CompilerType>
GetRuntimeType(CompilerType base_type)417 ObjCLanguageRuntime::GetRuntimeType(CompilerType base_type) {
418 CompilerType class_type;
419 bool is_pointer_type = false;
420
421 if (TypeSystemClang::IsObjCObjectPointerType(base_type, &class_type))
422 is_pointer_type = true;
423 else if (TypeSystemClang::IsObjCObjectOrInterfaceType(base_type))
424 class_type = base_type;
425 else
426 return llvm::None;
427
428 if (!class_type)
429 return llvm::None;
430
431 ConstString class_name(class_type.GetTypeName());
432 if (!class_name)
433 return llvm::None;
434
435 TypeSP complete_objc_class_type_sp = LookupInCompleteClassCache(class_name);
436 if (!complete_objc_class_type_sp)
437 return llvm::None;
438
439 CompilerType complete_class(
440 complete_objc_class_type_sp->GetFullCompilerType());
441 if (complete_class.GetCompleteType()) {
442 if (is_pointer_type)
443 return complete_class.GetPointerType();
444 else
445 return complete_class;
446 }
447
448 return llvm::None;
449 }
450