1//===-- Trace.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 "lldb/Target/Trace.h"
10
11#include "llvm/Support/Format.h"
12
13#include "lldb/Core/Module.h"
14#include "lldb/Core/PluginManager.h"
15#include "lldb/Symbol/Function.h"
16#include "lldb/Target/ExecutionContext.h"
17#include "lldb/Target/Process.h"
18#include "lldb/Target/SectionLoadList.h"
19#include "lldb/Target/Thread.h"
20#include "lldb/Utility/LLDBLog.h"
21#include "lldb/Utility/Stream.h"
22#include <optional>
23
24using namespace lldb;
25using namespace lldb_private;
26using namespace llvm;
27
28// Helper structs used to extract the type of a JSON trace bundle description
29// object without having to parse the entire object.
30
31struct JSONSimpleTraceBundleDescription {
32 std::string type;
33};
34
35namespace llvm {
36namespace json {
37
38bool fromJSON(const Value &value, JSONSimpleTraceBundleDescription &bundle,
39 Path path) {
40 json::ObjectMapper o(value, path);
41 return o && o.map(Prop: "type", Out&: bundle.type);
42}
43
44} // namespace json
45} // namespace llvm
46
47/// Helper functions for fetching data in maps and returning Optionals or
48/// pointers instead of iterators for simplicity. It's worth mentioning that the
49/// Optionals version can't return the inner data by reference because of
50/// limitations in move constructors.
51/// \{
52template <typename K, typename V>
53static std::optional<V> Lookup(DenseMap<K, V> &map, K k) {
54 auto it = map.find(k);
55 if (it == map.end())
56 return std::nullopt;
57 return it->second;
58}
59
60template <typename K, typename V>
61static V *LookupAsPtr(DenseMap<K, V> &map, K k) {
62 auto it = map.find(k);
63 if (it == map.end())
64 return nullptr;
65 return &it->second;
66}
67
68/// Similar to the methods above but it looks for an item in a map of maps.
69template <typename K1, typename K2, typename V>
70static std::optional<V> Lookup(DenseMap<K1, DenseMap<K2, V>> &map, K1 k1,
71 K2 k2) {
72 auto it = map.find(k1);
73 if (it == map.end())
74 return std::nullopt;
75 return Lookup(it->second, k2);
76}
77
78/// Similar to the methods above but it looks for an item in a map of maps.
79template <typename K1, typename K2, typename V>
80static V *LookupAsPtr(DenseMap<K1, DenseMap<K2, V>> &map, K1 k1, K2 k2) {
81 auto it = map.find(k1);
82 if (it == map.end())
83 return nullptr;
84 return LookupAsPtr(it->second, k2);
85}
86/// \}
87
88static Error createInvalidPlugInError(StringRef plugin_name) {
89 return createStringError(
90 EC: std::errc::invalid_argument,
91 Fmt: "no trace plug-in matches the specified type: \"%s\"",
92 Vals: plugin_name.data());
93}
94
95Expected<lldb::TraceSP>
96Trace::LoadPostMortemTraceFromFile(Debugger &debugger,
97 const FileSpec &trace_description_file) {
98
99 auto buffer_or_error =
100 MemoryBuffer::getFile(Filename: trace_description_file.GetPath());
101 if (!buffer_or_error) {
102 return createStringError(EC: std::errc::invalid_argument,
103 Fmt: "could not open input file: %s - %s.",
104 Vals: trace_description_file.GetPath().c_str(),
105 Vals: buffer_or_error.getError().message().c_str());
106 }
107
108 Expected<json::Value> session_file =
109 json::parse(JSON: buffer_or_error.get()->getBuffer().str());
110 if (!session_file) {
111 return session_file.takeError();
112 }
113
114 return Trace::FindPluginForPostMortemProcess(
115 debugger, bundle_description: *session_file,
116 session_file_dir: trace_description_file.GetDirectory().AsCString());
117}
118
119Expected<lldb::TraceSP> Trace::FindPluginForPostMortemProcess(
120 Debugger &debugger, const json::Value &trace_bundle_description,
121 StringRef bundle_dir) {
122 JSONSimpleTraceBundleDescription json_bundle;
123 json::Path::Root root("traceBundle");
124 if (!json::fromJSON(value: trace_bundle_description, bundle&: json_bundle, path: root))
125 return root.getError();
126
127 if (auto create_callback =
128 PluginManager::GetTraceCreateCallback(plugin_name: json_bundle.type))
129 return create_callback(trace_bundle_description, bundle_dir, debugger);
130
131 return createInvalidPlugInError(plugin_name: json_bundle.type);
132}
133
134Expected<lldb::TraceSP> Trace::FindPluginForLiveProcess(llvm::StringRef name,
135 Process &process) {
136 if (!process.IsLiveDebugSession())
137 return createStringError(EC: inconvertibleErrorCode(),
138 S: "Can't trace non-live processes");
139
140 if (auto create_callback =
141 PluginManager::GetTraceCreateCallbackForLiveProcess(plugin_name: name))
142 return create_callback(process);
143
144 return createInvalidPlugInError(plugin_name: name);
145}
146
147Expected<StringRef> Trace::FindPluginSchema(StringRef name) {
148 StringRef schema = PluginManager::GetTraceSchema(plugin_name: name);
149 if (!schema.empty())
150 return schema;
151
152 return createInvalidPlugInError(plugin_name: name);
153}
154
155Error Trace::Start(const llvm::json::Value &request) {
156 if (!m_live_process)
157 return createStringError(
158 EC: inconvertibleErrorCode(),
159 S: "Attempted to start tracing without a live process.");
160 return m_live_process->TraceStart(request);
161}
162
163Error Trace::Stop() {
164 if (!m_live_process)
165 return createStringError(
166 EC: inconvertibleErrorCode(),
167 S: "Attempted to stop tracing without a live process.");
168 return m_live_process->TraceStop(request: TraceStopRequest(GetPluginName()));
169}
170
171Error Trace::Stop(llvm::ArrayRef<lldb::tid_t> tids) {
172 if (!m_live_process)
173 return createStringError(
174 EC: inconvertibleErrorCode(),
175 S: "Attempted to stop tracing without a live process.");
176 return m_live_process->TraceStop(request: TraceStopRequest(GetPluginName(), tids));
177}
178
179Expected<std::string> Trace::GetLiveProcessState() {
180 if (!m_live_process)
181 return createStringError(
182 EC: inconvertibleErrorCode(),
183 S: "Attempted to fetch live trace information without a live process.");
184 return m_live_process->TraceGetState(type: GetPluginName());
185}
186
187std::optional<uint64_t>
188Trace::GetLiveThreadBinaryDataSize(lldb::tid_t tid, llvm::StringRef kind) {
189 Storage &storage = GetUpdatedStorage();
190 return Lookup(map&: storage.live_thread_data, k1: tid, k2: ConstString(kind));
191}
192
193std::optional<uint64_t> Trace::GetLiveCpuBinaryDataSize(lldb::cpu_id_t cpu_id,
194 llvm::StringRef kind) {
195 Storage &storage = GetUpdatedStorage();
196 return Lookup(map&: storage.live_cpu_data_sizes, k1: cpu_id, k2: ConstString(kind));
197}
198
199std::optional<uint64_t>
200Trace::GetLiveProcessBinaryDataSize(llvm::StringRef kind) {
201 Storage &storage = GetUpdatedStorage();
202 return Lookup(map&: storage.live_process_data, k: ConstString(kind));
203}
204
205Expected<std::vector<uint8_t>>
206Trace::GetLiveTraceBinaryData(const TraceGetBinaryDataRequest &request,
207 uint64_t expected_size) {
208 if (!m_live_process)
209 return createStringError(
210 EC: inconvertibleErrorCode(),
211 S: formatv(Fmt: "Attempted to fetch live trace data without a live process. "
212 "Data kind = {0}, tid = {1}, cpu id = {2}.",
213 Vals: request.kind, Vals: request.tid, Vals: request.cpu_id));
214
215 Expected<std::vector<uint8_t>> data =
216 m_live_process->TraceGetBinaryData(request);
217
218 if (!data)
219 return data.takeError();
220
221 if (data->size() != expected_size)
222 return createStringError(
223 EC: inconvertibleErrorCode(),
224 S: formatv(Fmt: "Got incomplete live trace data. Data kind = {0}, expected "
225 "size = {1}, actual size = {2}, tid = {3}, cpu id = {4}",
226 Vals: request.kind, Vals&: expected_size, Vals: data->size(), Vals: request.tid,
227 Vals: request.cpu_id));
228
229 return data;
230}
231
232Expected<std::vector<uint8_t>>
233Trace::GetLiveThreadBinaryData(lldb::tid_t tid, llvm::StringRef kind) {
234 std::optional<uint64_t> size = GetLiveThreadBinaryDataSize(tid, kind);
235 if (!size)
236 return createStringError(
237 EC: inconvertibleErrorCode(),
238 Fmt: "Tracing data \"%s\" is not available for thread %" PRIu64 ".",
239 Vals: kind.data(), Vals: tid);
240
241 TraceGetBinaryDataRequest request{.type: GetPluginName().str(), .kind: kind.str(), .tid: tid,
242 /*cpu_id=*/std::nullopt};
243 return GetLiveTraceBinaryData(request, expected_size: *size);
244}
245
246Expected<std::vector<uint8_t>>
247Trace::GetLiveCpuBinaryData(lldb::cpu_id_t cpu_id, llvm::StringRef kind) {
248 if (!m_live_process)
249 return createStringError(
250 EC: inconvertibleErrorCode(),
251 S: "Attempted to fetch live cpu data without a live process.");
252 std::optional<uint64_t> size = GetLiveCpuBinaryDataSize(cpu_id, kind);
253 if (!size)
254 return createStringError(
255 EC: inconvertibleErrorCode(),
256 Fmt: "Tracing data \"%s\" is not available for cpu_id %" PRIu64 ".",
257 Vals: kind.data(), Vals: cpu_id);
258
259 TraceGetBinaryDataRequest request{.type: GetPluginName().str(), .kind: kind.str(),
260 /*tid=*/std::nullopt, .cpu_id: cpu_id};
261 return m_live_process->TraceGetBinaryData(request);
262}
263
264Expected<std::vector<uint8_t>>
265Trace::GetLiveProcessBinaryData(llvm::StringRef kind) {
266 std::optional<uint64_t> size = GetLiveProcessBinaryDataSize(kind);
267 if (!size)
268 return createStringError(
269 EC: inconvertibleErrorCode(),
270 Fmt: "Tracing data \"%s\" is not available for the process.", Vals: kind.data());
271
272 TraceGetBinaryDataRequest request{.type: GetPluginName().str(), .kind: kind.str(),
273 /*tid=*/std::nullopt,
274 /*cpu_id*/ std::nullopt};
275 return GetLiveTraceBinaryData(request, expected_size: *size);
276}
277
278Trace::Storage &Trace::GetUpdatedStorage() {
279 RefreshLiveProcessState();
280 return m_storage;
281}
282
283const char *Trace::RefreshLiveProcessState() {
284 if (!m_live_process)
285 return nullptr;
286
287 uint32_t new_stop_id = m_live_process->GetStopID();
288 if (new_stop_id == m_stop_id)
289 return nullptr;
290
291 Log *log = GetLog(mask: LLDBLog::Target);
292 LLDB_LOG(log, "Trace::RefreshLiveProcessState invoked");
293
294 m_stop_id = new_stop_id;
295 m_storage = Trace::Storage();
296
297 auto do_refresh = [&]() -> Error {
298 Expected<std::string> json_string = GetLiveProcessState();
299 if (!json_string)
300 return json_string.takeError();
301
302 Expected<TraceGetStateResponse> live_process_state =
303 json::parse<TraceGetStateResponse>(JSON: *json_string,
304 RootName: "TraceGetStateResponse");
305 if (!live_process_state)
306 return live_process_state.takeError();
307
308 if (live_process_state->warnings) {
309 for (std::string &warning : *live_process_state->warnings)
310 LLDB_LOG(log, "== Warning when fetching the trace state: {0}", warning);
311 }
312
313 for (const TraceThreadState &thread_state :
314 live_process_state->traced_threads) {
315 for (const TraceBinaryData &item : thread_state.binary_data)
316 m_storage.live_thread_data[thread_state.tid].insert(
317 KV: {ConstString(item.kind), item.size});
318 }
319
320 LLDB_LOG(log, "== Found {0} threads being traced",
321 live_process_state->traced_threads.size());
322
323 if (live_process_state->cpus) {
324 m_storage.cpus.emplace();
325 for (const TraceCpuState &cpu_state : *live_process_state->cpus) {
326 m_storage.cpus->push_back(x: cpu_state.id);
327 for (const TraceBinaryData &item : cpu_state.binary_data)
328 m_storage.live_cpu_data_sizes[cpu_state.id].insert(
329 KV: {ConstString(item.kind), item.size});
330 }
331 LLDB_LOG(log, "== Found {0} cpu cpus being traced",
332 live_process_state->cpus->size());
333 }
334
335 for (const TraceBinaryData &item : live_process_state->process_binary_data)
336 m_storage.live_process_data.insert(KV: {ConstString(item.kind), item.size});
337
338 return DoRefreshLiveProcessState(state: std::move(*live_process_state),
339 json_response: *json_string);
340 };
341
342 if (Error err = do_refresh()) {
343 m_storage.live_refresh_error = toString(E: std::move(err));
344 return m_storage.live_refresh_error->c_str();
345 }
346
347 return nullptr;
348}
349
350Trace::Trace(ArrayRef<ProcessSP> postmortem_processes,
351 std::optional<std::vector<lldb::cpu_id_t>> postmortem_cpus) {
352 for (ProcessSP process_sp : postmortem_processes)
353 m_storage.postmortem_processes.push_back(x: process_sp.get());
354 m_storage.cpus = postmortem_cpus;
355}
356
357Process *Trace::GetLiveProcess() { return m_live_process; }
358
359ArrayRef<Process *> Trace::GetPostMortemProcesses() {
360 return m_storage.postmortem_processes;
361}
362
363std::vector<Process *> Trace::GetAllProcesses() {
364 if (Process *proc = GetLiveProcess())
365 return {proc};
366 return GetPostMortemProcesses();
367}
368
369uint32_t Trace::GetStopID() {
370 RefreshLiveProcessState();
371 return m_stop_id;
372}
373
374llvm::Expected<FileSpec>
375Trace::GetPostMortemThreadDataFile(lldb::tid_t tid, llvm::StringRef kind) {
376 Storage &storage = GetUpdatedStorage();
377 if (std::optional<FileSpec> file =
378 Lookup(map&: storage.postmortem_thread_data, k1: tid, k2: ConstString(kind)))
379 return *file;
380 else
381 return createStringError(
382 EC: inconvertibleErrorCode(),
383 S: formatv(Fmt: "The thread with tid={0} doesn't have the tracing data {1}",
384 Vals&: tid, Vals&: kind));
385}
386
387llvm::Expected<FileSpec> Trace::GetPostMortemCpuDataFile(lldb::cpu_id_t cpu_id,
388 llvm::StringRef kind) {
389 Storage &storage = GetUpdatedStorage();
390 if (std::optional<FileSpec> file =
391 Lookup(map&: storage.postmortem_cpu_data, k1: cpu_id, k2: ConstString(kind)))
392 return *file;
393 else
394 return createStringError(
395 EC: inconvertibleErrorCode(),
396 S: formatv(Fmt: "The cpu with id={0} doesn't have the tracing data {1}", Vals&: cpu_id,
397 Vals&: kind));
398}
399
400void Trace::SetPostMortemThreadDataFile(lldb::tid_t tid, llvm::StringRef kind,
401 FileSpec file_spec) {
402 Storage &storage = GetUpdatedStorage();
403 storage.postmortem_thread_data[tid].insert(KV: {ConstString(kind), file_spec});
404}
405
406void Trace::SetPostMortemCpuDataFile(lldb::cpu_id_t cpu_id,
407 llvm::StringRef kind, FileSpec file_spec) {
408 Storage &storage = GetUpdatedStorage();
409 storage.postmortem_cpu_data[cpu_id].insert(KV: {ConstString(kind), file_spec});
410}
411
412llvm::Error
413Trace::OnLiveThreadBinaryDataRead(lldb::tid_t tid, llvm::StringRef kind,
414 OnBinaryDataReadCallback callback) {
415 Expected<std::vector<uint8_t>> data = GetLiveThreadBinaryData(tid, kind);
416 if (!data)
417 return data.takeError();
418 return callback(*data);
419}
420
421llvm::Error Trace::OnLiveCpuBinaryDataRead(lldb::cpu_id_t cpu_id,
422 llvm::StringRef kind,
423 OnBinaryDataReadCallback callback) {
424 Storage &storage = GetUpdatedStorage();
425 if (std::vector<uint8_t> *cpu_data =
426 LookupAsPtr(map&: storage.live_cpu_data, k1: cpu_id, k2: ConstString(kind)))
427 return callback(*cpu_data);
428
429 Expected<std::vector<uint8_t>> data = GetLiveCpuBinaryData(cpu_id, kind);
430 if (!data)
431 return data.takeError();
432 auto it = storage.live_cpu_data[cpu_id].insert(
433 KV: {ConstString(kind), std::move(*data)});
434 return callback(it.first->second);
435}
436
437llvm::Error Trace::OnDataFileRead(FileSpec file,
438 OnBinaryDataReadCallback callback) {
439 ErrorOr<std::unique_ptr<MemoryBuffer>> trace_or_error =
440 MemoryBuffer::getFile(Filename: file.GetPath());
441 if (std::error_code err = trace_or_error.getError())
442 return createStringError(
443 EC: inconvertibleErrorCode(), Fmt: "Failed fetching trace-related file %s. %s",
444 Vals: file.GetPath().c_str(), Vals: toString(E: errorCodeToError(EC: err)).c_str());
445
446 MemoryBuffer &data = **trace_or_error;
447 ArrayRef<uint8_t> array_ref(
448 reinterpret_cast<const uint8_t *>(data.getBufferStart()),
449 data.getBufferSize());
450 return callback(array_ref);
451}
452
453llvm::Error
454Trace::OnPostMortemThreadBinaryDataRead(lldb::tid_t tid, llvm::StringRef kind,
455 OnBinaryDataReadCallback callback) {
456 if (Expected<FileSpec> file = GetPostMortemThreadDataFile(tid, kind))
457 return OnDataFileRead(file: *file, callback);
458 else
459 return file.takeError();
460}
461
462llvm::Error
463Trace::OnPostMortemCpuBinaryDataRead(lldb::cpu_id_t cpu_id,
464 llvm::StringRef kind,
465 OnBinaryDataReadCallback callback) {
466 if (Expected<FileSpec> file = GetPostMortemCpuDataFile(cpu_id, kind))
467 return OnDataFileRead(file: *file, callback);
468 else
469 return file.takeError();
470}
471
472llvm::Error Trace::OnThreadBinaryDataRead(lldb::tid_t tid, llvm::StringRef kind,
473 OnBinaryDataReadCallback callback) {
474 if (m_live_process)
475 return OnLiveThreadBinaryDataRead(tid, kind, callback);
476 else
477 return OnPostMortemThreadBinaryDataRead(tid, kind, callback);
478}
479
480llvm::Error
481Trace::OnAllCpusBinaryDataRead(llvm::StringRef kind,
482 OnCpusBinaryDataReadCallback callback) {
483 DenseMap<cpu_id_t, ArrayRef<uint8_t>> buffers;
484 Storage &storage = GetUpdatedStorage();
485 if (!storage.cpus)
486 return Error::success();
487
488 std::function<Error(std::vector<cpu_id_t>::iterator)> process_cpu =
489 [&](std::vector<cpu_id_t>::iterator cpu_id) -> Error {
490 if (cpu_id == storage.cpus->end())
491 return callback(buffers);
492
493 return OnCpuBinaryDataRead(cpu_id: *cpu_id, kind,
494 callback: [&](ArrayRef<uint8_t> data) -> Error {
495 buffers.try_emplace(Key: *cpu_id, Args&: data);
496 auto next_id = cpu_id;
497 next_id++;
498 return process_cpu(next_id);
499 });
500 };
501 return process_cpu(storage.cpus->begin());
502}
503
504llvm::Error Trace::OnCpuBinaryDataRead(lldb::cpu_id_t cpu_id,
505 llvm::StringRef kind,
506 OnBinaryDataReadCallback callback) {
507 if (m_live_process)
508 return OnLiveCpuBinaryDataRead(cpu_id, kind, callback);
509 else
510 return OnPostMortemCpuBinaryDataRead(cpu_id, kind, callback);
511}
512
513ArrayRef<lldb::cpu_id_t> Trace::GetTracedCpus() {
514 Storage &storage = GetUpdatedStorage();
515 if (storage.cpus)
516 return *storage.cpus;
517 return {};
518}
519
520std::vector<Process *> Trace::GetTracedProcesses() {
521 std::vector<Process *> processes;
522 Storage &storage = GetUpdatedStorage();
523
524 for (Process *proc : storage.postmortem_processes)
525 processes.push_back(x: proc);
526
527 if (m_live_process)
528 processes.push_back(x: m_live_process);
529 return processes;
530}
531

source code of lldb/source/Target/Trace.cpp