LLDB mainline
AppleObjCClassDescriptorV2.cpp
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1//===-- AppleObjCClassDescriptorV2.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
10
12#include "lldb/Target/ABI.h"
14#include "lldb/Utility/Log.h"
15
16using namespace lldb;
17using namespace lldb_private;
18
20 Process *process, std::unique_ptr<objc_class_t> &objc_class) const {
21 objc_class = std::make_unique<objc_class_t>();
22
23 bool ret = objc_class->Read(process, m_objc_class_ptr);
24
25 if (!ret)
26 objc_class.reset();
27
28 return ret;
29}
30
32 switch (process->GetAddressByteSize()) {
33 case 4:
34 return 0xfffffffcUL;
35 case 8:
36 return 0x00007ffffffffff8UL;
37 default:
38 break;
39 }
40
42}
43
45 lldb::addr_t addr) {
46 size_t ptr_size = process->GetAddressByteSize();
47
48 size_t objc_class_size = ptr_size // uintptr_t isa;
49 + ptr_size // Class superclass;
50 + ptr_size // void *cache;
51 + ptr_size // IMP *vtable;
52 + ptr_size; // uintptr_t data_NEVER_USE;
53
54 DataBufferHeap objc_class_buf(objc_class_size, '\0');
56
57 process->ReadMemory(addr, objc_class_buf.GetBytes(), objc_class_size, error);
58 if (error.Fail()) {
59 return false;
60 }
61
62 DataExtractor extractor(objc_class_buf.GetBytes(), objc_class_size,
63 process->GetByteOrder(),
64 process->GetAddressByteSize());
65
66 lldb::offset_t cursor = 0;
67
68 m_isa = extractor.GetAddress_unchecked(&cursor); // uintptr_t isa;
69 m_superclass = extractor.GetAddress_unchecked(&cursor); // Class superclass;
70 m_cache_ptr = extractor.GetAddress_unchecked(&cursor); // void *cache;
71 m_vtable_ptr = extractor.GetAddress_unchecked(&cursor); // IMP *vtable;
72 lldb::addr_t data_NEVER_USE =
73 extractor.GetAddress_unchecked(&cursor); // uintptr_t data_NEVER_USE;
74
75 m_flags = (uint8_t)(data_NEVER_USE & (lldb::addr_t)3);
76 m_data_ptr = data_NEVER_USE & GetClassDataMask(process);
77
78 if (ABISP abi_sp = process->GetABI()) {
79 m_isa = abi_sp->FixCodeAddress(m_isa);
80 m_superclass = abi_sp->FixCodeAddress(m_superclass);
81 m_data_ptr = abi_sp->FixCodeAddress(m_data_ptr);
82 }
83 return true;
84}
85
87 size_t ptr_size = process->GetAddressByteSize();
88
89 size_t size = sizeof(uint32_t) // uint32_t flags;
90 + sizeof(uint32_t) // uint32_t version;
91 + ptr_size // const class_ro_t *ro;
92 + ptr_size // union { method_list_t **method_lists;
93 // method_list_t *method_list; };
94 + ptr_size // struct chained_property_list *properties;
95 + ptr_size // const protocol_list_t **protocols;
96 + ptr_size // Class firstSubclass;
97 + ptr_size; // Class nextSiblingClass;
98
99 DataBufferHeap buffer(size, '\0');
101
102 process->ReadMemory(addr, buffer.GetBytes(), size, error);
103 if (error.Fail()) {
104 return false;
105 }
106
107 DataExtractor extractor(buffer.GetBytes(), size, process->GetByteOrder(),
108 process->GetAddressByteSize());
109
110 lldb::offset_t cursor = 0;
111
112 m_flags = extractor.GetU32_unchecked(&cursor);
113 m_version = extractor.GetU32_unchecked(&cursor);
114 m_ro_ptr = extractor.GetAddress_unchecked(&cursor);
115 if (ABISP abi_sp = process->GetABI())
116 m_ro_ptr = abi_sp->FixCodeAddress(m_ro_ptr);
117 m_method_list_ptr = extractor.GetAddress_unchecked(&cursor);
118 m_properties_ptr = extractor.GetAddress_unchecked(&cursor);
119 m_firstSubclass = extractor.GetAddress_unchecked(&cursor);
120 m_nextSiblingClass = extractor.GetAddress_unchecked(&cursor);
121
122 if (m_ro_ptr & 1) {
123 DataBufferHeap buffer(ptr_size, '\0');
124 process->ReadMemory(m_ro_ptr ^ 1, buffer.GetBytes(), ptr_size, error);
125 if (error.Fail())
126 return false;
127 cursor = 0;
128 DataExtractor extractor(buffer.GetBytes(), ptr_size,
129 process->GetByteOrder(),
130 process->GetAddressByteSize());
131 m_ro_ptr = extractor.GetAddress_unchecked(&cursor);
132 if (ABISP abi_sp = process->GetABI())
133 m_ro_ptr = abi_sp->FixCodeAddress(m_ro_ptr);
134 }
135
136 return true;
137}
138
140 size_t ptr_size = process->GetAddressByteSize();
141
142 size_t size = sizeof(uint32_t) // uint32_t flags;
143 + sizeof(uint32_t) // uint32_t instanceStart;
144 + sizeof(uint32_t) // uint32_t instanceSize;
145 + (ptr_size == 8 ? sizeof(uint32_t)
146 : 0) // uint32_t reserved; // __LP64__ only
147 + ptr_size // const uint8_t *ivarLayout;
148 + ptr_size // const char *name;
149 + ptr_size // const method_list_t *baseMethods;
150 + ptr_size // const protocol_list_t *baseProtocols;
151 + ptr_size // const ivar_list_t *ivars;
152 + ptr_size // const uint8_t *weakIvarLayout;
153 + ptr_size; // const property_list_t *baseProperties;
154
155 DataBufferHeap buffer(size, '\0');
157
158 process->ReadMemory(addr, buffer.GetBytes(), size, error);
159 if (error.Fail()) {
160 return false;
161 }
162
163 DataExtractor extractor(buffer.GetBytes(), size, process->GetByteOrder(),
164 process->GetAddressByteSize());
165
166 lldb::offset_t cursor = 0;
167
168 m_flags = extractor.GetU32_unchecked(&cursor);
169 m_instanceStart = extractor.GetU32_unchecked(&cursor);
170 m_instanceSize = extractor.GetU32_unchecked(&cursor);
171 if (ptr_size == 8)
172 m_reserved = extractor.GetU32_unchecked(&cursor);
173 else
174 m_reserved = 0;
175 m_ivarLayout_ptr = extractor.GetAddress_unchecked(&cursor);
176 m_name_ptr = extractor.GetAddress_unchecked(&cursor);
177 m_baseMethods_ptr = extractor.GetAddress_unchecked(&cursor);
178 m_baseProtocols_ptr = extractor.GetAddress_unchecked(&cursor);
179 m_ivars_ptr = extractor.GetAddress_unchecked(&cursor);
180 m_weakIvarLayout_ptr = extractor.GetAddress_unchecked(&cursor);
181 m_baseProperties_ptr = extractor.GetAddress_unchecked(&cursor);
182
183 DataBufferHeap name_buf(1024, '\0');
184
185 process->ReadCStringFromMemory(m_name_ptr, (char *)name_buf.GetBytes(),
186 name_buf.GetByteSize(), error);
187
188 if (error.Fail()) {
189 return false;
190 }
191
192 m_name.assign((char *)name_buf.GetBytes());
193
194 return true;
195}
196
198 Process *process, const objc_class_t &objc_class,
199 std::unique_ptr<class_ro_t> &class_ro,
200 std::unique_ptr<class_rw_t> &class_rw) const {
201 class_ro.reset();
202 class_rw.reset();
203
205 uint32_t class_row_t_flags = process->ReadUnsignedIntegerFromMemory(
206 objc_class.m_data_ptr, sizeof(uint32_t), 0, error);
207 if (!error.Success())
208 return false;
209
210 if (class_row_t_flags & RW_REALIZED) {
211 class_rw = std::make_unique<class_rw_t>();
212
213 if (!class_rw->Read(process, objc_class.m_data_ptr)) {
214 class_rw.reset();
215 return false;
216 }
217
218 class_ro = std::make_unique<class_ro_t>();
219
220 if (!class_ro->Read(process, class_rw->m_ro_ptr)) {
221 class_rw.reset();
222 class_ro.reset();
223 return false;
224 }
225 } else {
226 class_ro = std::make_unique<class_ro_t>();
227
228 if (!class_ro->Read(process, objc_class.m_data_ptr)) {
229 class_ro.reset();
230 return false;
231 }
232 }
233
234 return true;
235}
236
238 lldb::addr_t addr) {
239 size_t size = sizeof(uint32_t) // uint32_t entsize_NEVER_USE;
240 + sizeof(uint32_t); // uint32_t count;
241
242 DataBufferHeap buffer(size, '\0');
244
245 if (ABISP abi_sp = process->GetABI())
246 addr = abi_sp->FixCodeAddress(addr);
247 process->ReadMemory(addr, buffer.GetBytes(), size, error);
248 if (error.Fail()) {
249 return false;
250 }
251
252 DataExtractor extractor(buffer.GetBytes(), size, process->GetByteOrder(),
253 process->GetAddressByteSize());
254
255 lldb::offset_t cursor = 0;
256
257 uint32_t entsize = extractor.GetU32_unchecked(&cursor);
258 m_is_small = (entsize & 0x80000000) != 0;
259 m_has_direct_selector = (entsize & 0x40000000) != 0;
260 m_entsize = entsize & 0xfffc;
261 m_count = extractor.GetU32_unchecked(&cursor);
262 m_first_ptr = addr + cursor;
263
264 return true;
265}
266
268 lldb::addr_t relative_selector_base_addr,
269 bool is_small, bool has_direct_sel) {
270 size_t ptr_size = process->GetAddressByteSize();
271 size_t size = GetSize(process, is_small);
272
273 DataBufferHeap buffer(size, '\0');
275
276 process->ReadMemory(addr, buffer.GetBytes(), size, error);
277 if (error.Fail()) {
278 return false;
279 }
280
281 DataExtractor extractor(buffer.GetBytes(), size, process->GetByteOrder(),
282 ptr_size);
283 lldb::offset_t cursor = 0;
284
285 if (is_small) {
286 uint32_t nameref_offset = extractor.GetU32_unchecked(&cursor);
287 uint32_t types_offset = extractor.GetU32_unchecked(&cursor);
288 uint32_t imp_offset = extractor.GetU32_unchecked(&cursor);
289
290 m_name_ptr = addr + nameref_offset;
291
292 if (!has_direct_sel) {
293 // The SEL offset points to a SELRef. We need to dereference twice.
294 m_name_ptr = process->ReadUnsignedIntegerFromMemory(m_name_ptr, ptr_size,
295 0, error);
296 if (!error.Success())
297 return false;
298 } else if (relative_selector_base_addr != LLDB_INVALID_ADDRESS) {
299 m_name_ptr = relative_selector_base_addr + nameref_offset;
300 }
301 m_types_ptr = addr + 4 + types_offset;
302 m_imp_ptr = addr + 8 + imp_offset;
303 } else {
304 m_name_ptr = extractor.GetAddress_unchecked(&cursor);
305 m_types_ptr = extractor.GetAddress_unchecked(&cursor);
306 m_imp_ptr = extractor.GetAddress_unchecked(&cursor);
307 }
308
309 process->ReadCStringFromMemory(m_name_ptr, m_name, error);
310 if (error.Fail()) {
311 return false;
312 }
313
314 process->ReadCStringFromMemory(m_types_ptr, m_types, error);
315 return !error.Fail();
316}
317
319 size_t size = sizeof(uint32_t) // uint32_t entsize;
320 + sizeof(uint32_t); // uint32_t count;
321
322 DataBufferHeap buffer(size, '\0');
324
325 process->ReadMemory(addr, buffer.GetBytes(), size, error);
326 if (error.Fail()) {
327 return false;
328 }
329
330 DataExtractor extractor(buffer.GetBytes(), size, process->GetByteOrder(),
331 process->GetAddressByteSize());
332
333 lldb::offset_t cursor = 0;
334
335 m_entsize = extractor.GetU32_unchecked(&cursor);
336 m_count = extractor.GetU32_unchecked(&cursor);
337 m_first_ptr = addr + cursor;
338
339 return true;
340}
341
343 size_t size = GetSize(process);
344
345 DataBufferHeap buffer(size, '\0');
347
348 process->ReadMemory(addr, buffer.GetBytes(), size, error);
349 if (error.Fail()) {
350 return false;
351 }
352
353 DataExtractor extractor(buffer.GetBytes(), size, process->GetByteOrder(),
354 process->GetAddressByteSize());
355
356 lldb::offset_t cursor = 0;
357
358 m_offset_ptr = extractor.GetAddress_unchecked(&cursor);
359 m_name_ptr = extractor.GetAddress_unchecked(&cursor);
360 m_type_ptr = extractor.GetAddress_unchecked(&cursor);
361 m_alignment = extractor.GetU32_unchecked(&cursor);
362 m_size = extractor.GetU32_unchecked(&cursor);
363
364 process->ReadCStringFromMemory(m_name_ptr, m_name, error);
365 if (error.Fail()) {
366 return false;
367 }
368
369 process->ReadCStringFromMemory(m_type_ptr, m_type, error);
370 return !error.Fail();
371}
372
374 std::function<void(ObjCLanguageRuntime::ObjCISA)> const &superclass_func,
375 std::function<bool(const char *, const char *)> const &instance_method_func,
376 std::function<bool(const char *, const char *)> const &class_method_func,
377 std::function<bool(const char *, const char *, lldb::addr_t,
378 uint64_t)> const &ivar_func) const {
380
381 std::unique_ptr<objc_class_t> objc_class;
382 std::unique_ptr<class_ro_t> class_ro;
383 std::unique_ptr<class_rw_t> class_rw;
384
385 if (!Read_objc_class(process, objc_class))
386 return false;
387 if (!Read_class_row(process, *objc_class, class_ro, class_rw))
388 return false;
389
390 static ConstString NSObject_name("NSObject");
391
392 if (m_name != NSObject_name && superclass_func)
393 superclass_func(objc_class->m_superclass);
394
395 if (instance_method_func) {
396 std::unique_ptr<method_list_t> base_method_list;
397
398 base_method_list = std::make_unique<method_list_t>();
399 if (!base_method_list->Read(process, class_ro->m_baseMethods_ptr))
400 return false;
401
402 bool is_small = base_method_list->m_is_small;
403 bool has_direct_selector = base_method_list->m_has_direct_selector;
404
405 if (base_method_list->m_entsize != method_t::GetSize(process, is_small))
406 return false;
407
408 std::unique_ptr<method_t> method = std::make_unique<method_t>();
409 lldb::addr_t relative_selector_base_addr =
411 for (uint32_t i = 0, e = base_method_list->m_count; i < e; ++i) {
412 method->Read(process,
413 base_method_list->m_first_ptr +
414 (i * base_method_list->m_entsize),
415 relative_selector_base_addr, is_small, has_direct_selector);
416
417 if (instance_method_func(method->m_name.c_str(), method->m_types.c_str()))
418 break;
419 }
420 }
421
422 if (class_method_func) {
424
425 // We don't care about the metaclass's superclass, or its class methods.
426 // Its instance methods are our class methods.
427
428 if (metaclass) {
429 metaclass->Describe(
430 std::function<void(ObjCLanguageRuntime::ObjCISA)>(nullptr),
431 class_method_func,
432 std::function<bool(const char *, const char *)>(nullptr),
433 std::function<bool(const char *, const char *, lldb::addr_t,
434 uint64_t)>(nullptr));
435 }
436 }
437
438 if (ivar_func) {
439 if (class_ro->m_ivars_ptr != 0) {
440 ivar_list_t ivar_list;
441 if (!ivar_list.Read(process, class_ro->m_ivars_ptr))
442 return false;
443
444 if (ivar_list.m_entsize != ivar_t::GetSize(process))
445 return false;
446
447 ivar_t ivar;
448
449 for (uint32_t i = 0, e = ivar_list.m_count; i < e; ++i) {
450 ivar.Read(process, ivar_list.m_first_ptr + (i * ivar_list.m_entsize));
451
452 if (ivar_func(ivar.m_name.c_str(), ivar.m_type.c_str(),
453 ivar.m_offset_ptr, ivar.m_size))
454 break;
455 }
456 }
457 }
458
459 return true;
460}
461
463 if (!m_name) {
465
466 if (process) {
467 std::unique_ptr<objc_class_t> objc_class;
468 std::unique_ptr<class_ro_t> class_ro;
469 std::unique_ptr<class_rw_t> class_rw;
470
471 if (!Read_objc_class(process, objc_class))
472 return m_name;
473 if (!Read_class_row(process, *objc_class, class_ro, class_rw))
474 return m_name;
475
476 m_name = ConstString(class_ro->m_name.c_str());
477 }
478 }
479 return m_name;
480}
481
484
485 if (!process)
487
488 std::unique_ptr<objc_class_t> objc_class;
489
490 if (!Read_objc_class(process, objc_class))
492
493 return m_runtime.ObjCLanguageRuntime::GetClassDescriptorFromISA(
494 objc_class->m_superclass);
495}
496
499
500 if (!process)
502
503 std::unique_ptr<objc_class_t> objc_class;
504
505 if (!Read_objc_class(process, objc_class))
507
508 lldb::addr_t candidate_isa = m_runtime.GetPointerISA(objc_class->m_isa);
509
511 new ClassDescriptorV2(m_runtime, candidate_isa, nullptr));
512}
513
516
517 if (process) {
518 std::unique_ptr<objc_class_t> objc_class;
519 std::unique_ptr<class_ro_t> class_ro;
520 std::unique_ptr<class_rw_t> class_rw;
521
522 if (!Read_objc_class(process, objc_class))
523 return 0;
524 if (!Read_class_row(process, *objc_class, class_ro, class_rw))
525 return 0;
526
527 return class_ro->m_instanceSize;
528 }
529
530 return 0;
531}
532
534
535size_t ClassDescriptorV2::iVarsStorage::size() { return m_ivars.size(); }
536
538operator[](size_t idx) {
539 return m_ivars[idx];
540}
541
543 ClassDescriptorV2 &descriptor) {
544 if (m_filled)
545 return;
546 std::lock_guard<std::recursive_mutex> guard(m_mutex);
547 Log *log = GetLog(LLDBLog::Types);
548 LLDB_LOGV(log, "class_name = {0}", descriptor.GetClassName());
549 m_filled = true;
550 ObjCLanguageRuntime::EncodingToTypeSP encoding_to_type_sp(
551 runtime.GetEncodingToType());
552 Process *process(runtime.GetProcess());
553 if (!encoding_to_type_sp)
554 return;
555 descriptor.Describe(nullptr, nullptr, nullptr, [this, process,
556 encoding_to_type_sp,
557 log](const char *name,
558 const char *type,
559 lldb::addr_t offset_ptr,
560 uint64_t size) -> bool {
561 const bool for_expression = false;
562 const bool stop_loop = false;
563 LLDB_LOGV(log, "name = {0}, encoding = {1}, offset_ptr = {2:x}, size = {3}",
564 name, type, offset_ptr, size);
565 CompilerType ivar_type =
566 encoding_to_type_sp->RealizeType(type, for_expression);
567 if (ivar_type) {
568 LLDB_LOGV(log,
569 "name = {0}, encoding = {1}, offset_ptr = {2:x}, size = "
570 "{3}, type_size = {4}",
571 name, type, offset_ptr, size,
572 ivar_type.GetByteSize(nullptr).value_or(0));
573 Scalar offset_scalar;
575 const int offset_ptr_size = 4;
576 const bool is_signed = false;
577 size_t read = process->ReadScalarIntegerFromMemory(
578 offset_ptr, offset_ptr_size, is_signed, offset_scalar, error);
579 if (error.Success() && 4 == read) {
580 LLDB_LOGV(log, "offset_ptr = {0:x} --> {1}", offset_ptr,
581 offset_scalar.SInt());
582 m_ivars.push_back(
583 {ConstString(name), ivar_type, size, offset_scalar.SInt()});
584 } else
585 LLDB_LOGV(log, "offset_ptr = {0:x} --> read fail, read = %{1}",
586 offset_ptr, read);
587 }
588 return stop_loop;
589 });
590}
591
594}
static lldb::addr_t GetClassDataMask(Process *process)
static llvm::raw_ostream & error(Stream &strm)
#define LLDB_LOGV(log,...)
Definition: Log.h:351
EncodingToTypeSP GetEncodingToType() override
lldb::addr_t GetRelativeSelectorBaseAddr()
Returns the base address for relative method list selector strings.
void fill(AppleObjCRuntimeV2 &runtime, ClassDescriptorV2 &descriptor)
ObjCLanguageRuntime::ClassDescriptorSP GetSuperclass() override
bool Describe(std::function< void(ObjCLanguageRuntime::ObjCISA)> const &superclass_func, std::function< bool(const char *, const char *)> const &instance_method_func, std::function< bool(const char *, const char *)> const &class_method_func, std::function< bool(const char *, const char *, lldb::addr_t, uint64_t)> const &ivar_func) const override
bool Read_class_row(Process *process, const objc_class_t &objc_class, std::unique_ptr< class_ro_t > &class_ro, std::unique_ptr< class_rw_t > &class_rw) const
bool Read_objc_class(Process *process, std::unique_ptr< objc_class_t > &objc_class) const
ObjCLanguageRuntime::ClassDescriptorSP GetMetaclass() const override
Generic representation of a type in a programming language.
Definition: CompilerType.h:36
std::optional< uint64_t > GetByteSize(ExecutionContextScope *exe_scope) const
Return the size of the type in bytes.
A uniqued constant string class.
Definition: ConstString.h:39
A subclass of DataBuffer that stores a data buffer on the heap.
lldb::offset_t GetByteSize() const override
An data extractor class.
Definition: DataExtractor.h:48
uint32_t GetU32_unchecked(lldb::offset_t *offset_ptr) const
uint64_t GetAddress_unchecked(lldb::offset_t *offset_ptr) const
std::shared_ptr< ClassDescriptor > ClassDescriptorSP
std::shared_ptr< EncodingToType > EncodingToTypeSP
A plug-in interface definition class for debugging a process.
Definition: Process.h:342
size_t ReadScalarIntegerFromMemory(lldb::addr_t addr, uint32_t byte_size, bool is_signed, Scalar &scalar, Status &error)
Definition: Process.cpp:2225
size_t ReadCStringFromMemory(lldb::addr_t vm_addr, char *cstr, size_t cstr_max_len, Status &error)
Read a NULL terminated C string from memory.
Definition: Process.cpp:1992
virtual size_t ReadMemory(lldb::addr_t vm_addr, void *buf, size_t size, Status &error)
Read of memory from a process.
Definition: Process.cpp:1926
lldb::ByteOrder GetByteOrder() const
Definition: Process.cpp:3363
uint64_t ReadUnsignedIntegerFromMemory(lldb::addr_t load_addr, size_t byte_size, uint64_t fail_value, Status &error)
Reads an unsigned integer of the specified byte size from process memory.
Definition: Process.cpp:2067
uint32_t GetAddressByteSize() const
Definition: Process.cpp:3367
const lldb::ABISP & GetABI()
Definition: Process.cpp:1487
Process * GetProcess()
Definition: Runtime.h:22
int SInt(int fail_value=0) const
Definition: Scalar.cpp:318
An error handling class.
Definition: Status.h:44
#define LLDB_INVALID_ADDRESS
Definition: lldb-defines.h:74
A class that represents a running process on the host machine.
Log * GetLog(Cat mask)
Retrieve the Log object for the channel associated with the given log enum.
Definition: Log.h:309
Definition: SBAddress.h:15
uint64_t offset_t
Definition: lldb-types.h:87
uint64_t addr_t
Definition: lldb-types.h:83
bool Read(Process *process, lldb::addr_t addr)
bool Read(Process *process, lldb::addr_t addr)
bool Read(Process *process, lldb::addr_t addr)
bool Read(Process *process, lldb::addr_t addr)
bool Read(Process *process, lldb::addr_t addr)
bool Read(Process *process, lldb::addr_t addr, lldb::addr_t relative_method_lists_base_addr, bool, bool)
static size_t GetSize(Process *process, bool is_small)
bool Read(Process *process, lldb::addr_t addr)