xray-converter.cpp revision 360784 
1//===- xray-converter.cpp: XRay Trace Conversion --------------------------===//
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// Implements the trace conversion functions.
10//
11//===----------------------------------------------------------------------===//
12#include "xray-converter.h"
13
14#include "trie-node.h"
15#include "xray-registry.h"
16#include "llvm/DebugInfo/Symbolize/Symbolize.h"
17#include "llvm/Support/EndianStream.h"
18#include "llvm/Support/FileSystem.h"
19#include "llvm/Support/FormatVariadic.h"
20#include "llvm/Support/ScopedPrinter.h"
21#include "llvm/Support/YAMLTraits.h"
22#include "llvm/Support/raw_ostream.h"
23#include "llvm/XRay/InstrumentationMap.h"
24#include "llvm/XRay/Trace.h"
25#include "llvm/XRay/YAMLXRayRecord.h"
26
27using namespace llvm;
28using namespace xray;
29
30// llvm-xray convert
31// ----------------------------------------------------------------------------
32static cl::SubCommand Convert("convert", "Trace Format Conversion");
33static cl::opt<std::string> ConvertInput(cl::Positional,
34                                         cl::desc("<xray log file>"),
35                                         cl::Required, cl::sub(Convert));
36enum class ConvertFormats { BINARY, YAML, CHROME_TRACE_EVENT };
37static cl::opt<ConvertFormats> ConvertOutputFormat(
38    "output-format", cl::desc("output format"),
39    cl::values(clEnumValN(ConvertFormats::BINARY, "raw", "output in binary"),
40               clEnumValN(ConvertFormats::YAML, "yaml", "output in yaml"),
41               clEnumValN(ConvertFormats::CHROME_TRACE_EVENT, "trace_event",
42                          "Output in chrome's trace event format. "
43                          "May be visualized with the Catapult trace viewer.")),
44    cl::sub(Convert));
45static cl::alias ConvertOutputFormat2("f", cl::aliasopt(ConvertOutputFormat),
46                                      cl::desc("Alias for -output-format"));
47static cl::opt<std::string>
48    ConvertOutput("output", cl::value_desc("output file"), cl::init("-"),
49                  cl::desc("output file; use '-' for stdout"),
50                  cl::sub(Convert));
51static cl::alias ConvertOutput2("o", cl::aliasopt(ConvertOutput),
52                                cl::desc("Alias for -output"));
53
54static cl::opt<bool>
55    ConvertSymbolize("symbolize",
56                     cl::desc("symbolize function ids from the input log"),
57                     cl::init(false), cl::sub(Convert));
58static cl::alias ConvertSymbolize2("y", cl::aliasopt(ConvertSymbolize),
59                                   cl::desc("Alias for -symbolize"));
60
61static cl::opt<std::string>
62    ConvertInstrMap("instr_map",
63                    cl::desc("binary with the instrumentation map, or "
64                             "a separate instrumentation map"),
65                    cl::value_desc("binary with xray_instr_map"),
66                    cl::sub(Convert), cl::init(""));
67static cl::alias ConvertInstrMap2("m", cl::aliasopt(ConvertInstrMap),
68                                  cl::desc("Alias for -instr_map"));
69static cl::opt<bool> ConvertSortInput(
70    "sort",
71    cl::desc("determines whether to sort input log records by timestamp"),
72    cl::sub(Convert), cl::init(true));
73static cl::alias ConvertSortInput2("s", cl::aliasopt(ConvertSortInput),
74                                   cl::desc("Alias for -sort"));
75
76using llvm::yaml::Output;
77
78void TraceConverter::exportAsYAML(const Trace &Records, raw_ostream &OS) {
79  YAMLXRayTrace Trace;
80  const auto &FH = Records.getFileHeader();
81  Trace.Header = {FH.Version, FH.Type, FH.ConstantTSC, FH.NonstopTSC,
82                  FH.CycleFrequency};
83  Trace.Records.reserve(Records.size());
84  for (const auto &R : Records) {
85    Trace.Records.push_back({R.RecordType, R.CPU, R.Type, R.FuncId,
86                             Symbolize ? FuncIdHelper.SymbolOrNumber(R.FuncId)
87                                       : llvm::to_string(R.FuncId),
88                             R.TSC, R.TId, R.PId, R.CallArgs, R.Data});
89  }
90  Output Out(OS, nullptr, 0);
91  Out.setWriteDefaultValues(false);
92  Out << Trace;
93}
94
95void TraceConverter::exportAsRAWv1(const Trace &Records, raw_ostream &OS) {
96  // First write out the file header, in the correct endian-appropriate format
97  // (XRay assumes currently little endian).
98  support::endian::Writer Writer(OS, support::endianness::little);
99  const auto &FH = Records.getFileHeader();
100  Writer.write(FH.Version);
101  Writer.write(FH.Type);
102  uint32_t Bitfield{0};
103  if (FH.ConstantTSC)
104    Bitfield |= 1uL;
105  if (FH.NonstopTSC)
106    Bitfield |= 1uL << 1;
107  Writer.write(Bitfield);
108  Writer.write(FH.CycleFrequency);
109
110  // There's 16 bytes of padding at the end of the file header.
111  static constexpr uint32_t Padding4B = 0;
112  Writer.write(Padding4B);
113  Writer.write(Padding4B);
114  Writer.write(Padding4B);
115  Writer.write(Padding4B);
116
117  // Then write out the rest of the records, still in an endian-appropriate
118  // format.
119  for (const auto &R : Records) {
120    switch (R.Type) {
121    case RecordTypes::ENTER:
122    case RecordTypes::ENTER_ARG:
123      Writer.write(R.RecordType);
124      Writer.write(static_cast<uint8_t>(R.CPU));
125      Writer.write(uint8_t{0});
126      break;
127    case RecordTypes::EXIT:
128      Writer.write(R.RecordType);
129      Writer.write(static_cast<uint8_t>(R.CPU));
130      Writer.write(uint8_t{1});
131      break;
132    case RecordTypes::TAIL_EXIT:
133      Writer.write(R.RecordType);
134      Writer.write(static_cast<uint8_t>(R.CPU));
135      Writer.write(uint8_t{2});
136      break;
137    case RecordTypes::CUSTOM_EVENT:
138    case RecordTypes::TYPED_EVENT:
139      // Skip custom and typed event records for v1 logs.
140      continue;
141    }
142    Writer.write(R.FuncId);
143    Writer.write(R.TSC);
144    Writer.write(R.TId);
145
146    if (FH.Version >= 3)
147      Writer.write(R.PId);
148    else
149      Writer.write(Padding4B);
150
151    Writer.write(Padding4B);
152    Writer.write(Padding4B);
153  }
154}
155
156namespace {
157
158// A structure that allows building a dictionary of stack ids for the Chrome
159// trace event format.
160struct StackIdData {
161  // Each Stack of function calls has a unique ID.
162  unsigned id;
163
164  // Bookkeeping so that IDs can be maintained uniquely across threads.
165  // Traversal keeps sibling pointers to other threads stacks. This is helpful
166  // to determine when a thread encounters a new stack and should assign a new
167  // unique ID.
168  SmallVector<TrieNode<StackIdData> *, 4> siblings;
169};
170
171using StackTrieNode = TrieNode<StackIdData>;
172
173// A helper function to find the sibling nodes for an encountered function in a
174// thread of execution. Relies on the invariant that each time a new node is
175// traversed in a thread, sibling bidirectional pointers are maintained.
176SmallVector<StackTrieNode *, 4>
177findSiblings(StackTrieNode *parent, int32_t FnId, uint32_t TId,
178             const DenseMap<uint32_t, SmallVector<StackTrieNode *, 4>>
179                 &StackRootsByThreadId) {
180
181  SmallVector<StackTrieNode *, 4> Siblings{};
182
183  if (parent == nullptr) {
184    for (auto map_iter : StackRootsByThreadId) {
185      // Only look for siblings in other threads.
186      if (map_iter.first != TId)
187        for (auto node_iter : map_iter.second) {
188          if (node_iter->FuncId == FnId)
189            Siblings.push_back(node_iter);
190        }
191    }
192    return Siblings;
193  }
194
195  for (auto *ParentSibling : parent->ExtraData.siblings)
196    for (auto node_iter : ParentSibling->Callees)
197      if (node_iter->FuncId == FnId)
198        Siblings.push_back(node_iter);
199
200  return Siblings;
201}
202
203// Given a function being invoked in a thread with id TId, finds and returns the
204// StackTrie representing the function call stack. If no node exists, creates
205// the node. Assigns unique IDs to stacks newly encountered among all threads
206// and keeps sibling links up to when creating new nodes.
207StackTrieNode *findOrCreateStackNode(
208    StackTrieNode *Parent, int32_t FuncId, uint32_t TId,
209    DenseMap<uint32_t, SmallVector<StackTrieNode *, 4>> &StackRootsByThreadId,
210    DenseMap<unsigned, StackTrieNode *> &StacksByStackId, unsigned *id_counter,
211    std::forward_list<StackTrieNode> &NodeStore) {
212  SmallVector<StackTrieNode *, 4> &ParentCallees =
213      Parent == nullptr ? StackRootsByThreadId[TId] : Parent->Callees;
214  auto match = find_if(ParentCallees, [FuncId](StackTrieNode *ParentCallee) {
215    return FuncId == ParentCallee->FuncId;
216  });
217  if (match != ParentCallees.end())
218    return *match;
219
220  SmallVector<StackTrieNode *, 4> siblings =
221      findSiblings(Parent, FuncId, TId, StackRootsByThreadId);
222  if (siblings.empty()) {
223    NodeStore.push_front({FuncId, Parent, {}, {(*id_counter)++, {}}});
224    StackTrieNode *CurrentStack = &NodeStore.front();
225    StacksByStackId[*id_counter - 1] = CurrentStack;
226    ParentCallees.push_back(CurrentStack);
227    return CurrentStack;
228  }
229  unsigned stack_id = siblings[0]->ExtraData.id;
230  NodeStore.push_front({FuncId, Parent, {}, {stack_id, std::move(siblings)}});
231  StackTrieNode *CurrentStack = &NodeStore.front();
232  for (auto *sibling : CurrentStack->ExtraData.siblings)
233    sibling->ExtraData.siblings.push_back(CurrentStack);
234  ParentCallees.push_back(CurrentStack);
235  return CurrentStack;
236}
237
238void writeTraceViewerRecord(uint16_t Version, raw_ostream &OS, int32_t FuncId,
239                            uint32_t TId, uint32_t PId, bool Symbolize,
240                            const FuncIdConversionHelper &FuncIdHelper,
241                            double EventTimestampUs,
242                            const StackTrieNode &StackCursor,
243                            StringRef FunctionPhenotype) {
244  OS << "    ";
245  if (Version >= 3) {
246    OS << llvm::formatv(
247        R"({ "name" : "{0}", "ph" : "{1}", "tid" : "{2}", "pid" : "{3}", )"
248        R"("ts" : "{4:f4}", "sf" : "{5}" })",
249        (Symbolize ? FuncIdHelper.SymbolOrNumber(FuncId)
250                   : llvm::to_string(FuncId)),
251        FunctionPhenotype, TId, PId, EventTimestampUs,
252        StackCursor.ExtraData.id);
253  } else {
254    OS << llvm::formatv(
255        R"({ "name" : "{0}", "ph" : "{1}", "tid" : "{2}", "pid" : "1", )"
256        R"("ts" : "{3:f3}", "sf" : "{4}" })",
257        (Symbolize ? FuncIdHelper.SymbolOrNumber(FuncId)
258                   : llvm::to_string(FuncId)),
259        FunctionPhenotype, TId, EventTimestampUs, StackCursor.ExtraData.id);
260  }
261}
262
263} // namespace
264
265void TraceConverter::exportAsChromeTraceEventFormat(const Trace &Records,
266                                                    raw_ostream &OS) {
267  const auto &FH = Records.getFileHeader();
268  auto Version = FH.Version;
269  auto CycleFreq = FH.CycleFrequency;
270
271  unsigned id_counter = 0;
272
273  OS << "{\n  \"traceEvents\": [";
274  DenseMap<uint32_t, StackTrieNode *> StackCursorByThreadId{};
275  DenseMap<uint32_t, SmallVector<StackTrieNode *, 4>> StackRootsByThreadId{};
276  DenseMap<unsigned, StackTrieNode *> StacksByStackId{};
277  std::forward_list<StackTrieNode> NodeStore{};
278  int loop_count = 0;
279  for (const auto &R : Records) {
280    if (loop_count++ == 0)
281      OS << "\n";
282    else
283      OS << ",\n";
284
285    // Chrome trace event format always wants data in micros.
286    // CyclesPerMicro = CycleHertz / 10^6
287    // TSC / CyclesPerMicro == TSC * 10^6 / CycleHertz == MicroTimestamp
288    // Could lose some precision here by converting the TSC to a double to
289    // multiply by the period in micros. 52 bit mantissa is a good start though.
290    // TODO: Make feature request to Chrome Trace viewer to accept ticks and a
291    // frequency or do some more involved calculation to avoid dangers of
292    // conversion.
293    double EventTimestampUs = double(1000000) / CycleFreq * double(R.TSC);
294    StackTrieNode *&StackCursor = StackCursorByThreadId[R.TId];
295    switch (R.Type) {
296    case RecordTypes::CUSTOM_EVENT:
297    case RecordTypes::TYPED_EVENT:
298      // TODO: Support typed and custom event rendering on Chrome Trace Viewer.
299      break;
300    case RecordTypes::ENTER:
301    case RecordTypes::ENTER_ARG:
302      StackCursor = findOrCreateStackNode(StackCursor, R.FuncId, R.TId,
303                                          StackRootsByThreadId, StacksByStackId,
304                                          &id_counter, NodeStore);
305      // Each record is represented as a json dictionary with function name,
306      // type of B for begin or E for end, thread id, process id,
307      // timestamp in microseconds, and a stack frame id. The ids are logged
308      // in an id dictionary after the events.
309      writeTraceViewerRecord(Version, OS, R.FuncId, R.TId, R.PId, Symbolize,
310                             FuncIdHelper, EventTimestampUs, *StackCursor, "B");
311      break;
312    case RecordTypes::EXIT:
313    case RecordTypes::TAIL_EXIT:
314      // No entries to record end for.
315      if (StackCursor == nullptr)
316        break;
317      // Should we emit an END record anyway or account this condition?
318      // (And/Or in loop termination below)
319      StackTrieNode *PreviousCursor = nullptr;
320      do {
321        if (PreviousCursor != nullptr) {
322          OS << ",\n";
323        }
324        writeTraceViewerRecord(Version, OS, StackCursor->FuncId, R.TId, R.PId,
325                               Symbolize, FuncIdHelper, EventTimestampUs,
326                               *StackCursor, "E");
327        PreviousCursor = StackCursor;
328        StackCursor = StackCursor->Parent;
329      } while (PreviousCursor->FuncId != R.FuncId && StackCursor != nullptr);
330      break;
331    }
332  }
333  OS << "\n  ],\n"; // Close the Trace Events array.
334  OS << "  "
335     << "\"displayTimeUnit\": \"ns\",\n";
336
337  // The stackFrames dictionary substantially reduces size of the output file by
338  // avoiding repeating the entire call stack of function names for each entry.
339  OS << R"(  "stackFrames": {)";
340  int stack_frame_count = 0;
341  for (auto map_iter : StacksByStackId) {
342    if (stack_frame_count++ == 0)
343      OS << "\n";
344    else
345      OS << ",\n";
346    OS << "    ";
347    OS << llvm::formatv(
348        R"("{0}" : { "name" : "{1}")", map_iter.first,
349        (Symbolize ? FuncIdHelper.SymbolOrNumber(map_iter.second->FuncId)
350                   : llvm::to_string(map_iter.second->FuncId)));
351    if (map_iter.second->Parent != nullptr)
352      OS << llvm::formatv(R"(, "parent": "{0}")",
353                          map_iter.second->Parent->ExtraData.id);
354    OS << " }";
355  }
356  OS << "\n  }\n"; // Close the stack frames map.
357  OS << "}\n";     // Close the JSON entry.
358}
359
360namespace llvm {
361namespace xray {
362
363static CommandRegistration Unused(&Convert, []() -> Error {
364  // FIXME: Support conversion to BINARY when upgrading XRay trace versions.
365  InstrumentationMap Map;
366  if (!ConvertInstrMap.empty()) {
367    auto InstrumentationMapOrError = loadInstrumentationMap(ConvertInstrMap);
368    if (!InstrumentationMapOrError)
369      return joinErrors(make_error<StringError>(
370                            Twine("Cannot open instrumentation map '") +
371                                ConvertInstrMap + "'",
372                            std::make_error_code(std::errc::invalid_argument)),
373                        InstrumentationMapOrError.takeError());
374    Map = std::move(*InstrumentationMapOrError);
375  }
376
377  const auto &FunctionAddresses = Map.getFunctionAddresses();
378  symbolize::LLVMSymbolizer Symbolizer;
379  llvm::xray::FuncIdConversionHelper FuncIdHelper(ConvertInstrMap, Symbolizer,
380                                                  FunctionAddresses);
381  llvm::xray::TraceConverter TC(FuncIdHelper, ConvertSymbolize);
382  std::error_code EC;
383  raw_fd_ostream OS(ConvertOutput, EC,
384                    ConvertOutputFormat == ConvertFormats::BINARY
385                        ? sys::fs::OpenFlags::OF_None
386                        : sys::fs::OpenFlags::OF_Text);
387  if (EC)
388    return make_error<StringError>(
389        Twine("Cannot open file '") + ConvertOutput + "' for writing.", EC);
390
391  auto TraceOrErr = loadTraceFile(ConvertInput, ConvertSortInput);
392  if (!TraceOrErr)
393    return joinErrors(
394        make_error<StringError>(
395            Twine("Failed loading input file '") + ConvertInput + "'.",
396            std::make_error_code(std::errc::executable_format_error)),
397        TraceOrErr.takeError());
398
399  auto &T = *TraceOrErr;
400  switch (ConvertOutputFormat) {
401  case ConvertFormats::YAML:
402    TC.exportAsYAML(T, OS);
403    break;
404  case ConvertFormats::BINARY:
405    TC.exportAsRAWv1(T, OS);
406    break;
407  case ConvertFormats::CHROME_TRACE_EVENT:
408    TC.exportAsChromeTraceEventFormat(T, OS);
409    break;
410  }
411  return Error::success();
412});
413
414} // namespace xray
415} // namespace llvm
416