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1 //===- xray-converter.cpp: XRay Trace Conversion --------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // Implements the trace conversion functions.
11 //
12 //===----------------------------------------------------------------------===//
13 #include "xray-converter.h"
14 
15 #include "trie-node.h"
16 #include "xray-registry.h"
17 #include "llvm/DebugInfo/Symbolize/Symbolize.h"
18 #include "llvm/Support/EndianStream.h"
19 #include "llvm/Support/FileSystem.h"
20 #include "llvm/Support/FormatVariadic.h"
21 #include "llvm/Support/ScopedPrinter.h"
22 #include "llvm/Support/YAMLTraits.h"
23 #include "llvm/Support/raw_ostream.h"
24 #include "llvm/XRay/InstrumentationMap.h"
25 #include "llvm/XRay/Trace.h"
26 #include "llvm/XRay/YAMLXRayRecord.h"
27 
28 using namespace llvm;
29 using namespace xray;
30 
31 // llvm-xray convert
32 // ----------------------------------------------------------------------------
33 static cl::SubCommand Convert("convert", "Trace Format Conversion");
34 static cl::opt<std::string> ConvertInput(cl::Positional,
35                                          cl::desc("<xray log file>"),
36                                          cl::Required, cl::sub(Convert));
37 enum class ConvertFormats { BINARY, YAML, CHROME_TRACE_EVENT };
38 static cl::opt<ConvertFormats> ConvertOutputFormat(
39     "output-format", cl::desc("output format"),
40     cl::values(clEnumValN(ConvertFormats::BINARY, "raw", "output in binary"),
41                clEnumValN(ConvertFormats::YAML, "yaml", "output in yaml"),
42                clEnumValN(ConvertFormats::CHROME_TRACE_EVENT, "trace_event",
43                           "Output in chrome's trace event format. "
44                           "May be visualized with the Catapult trace viewer.")),
45     cl::sub(Convert));
46 static cl::alias ConvertOutputFormat2("f", cl::aliasopt(ConvertOutputFormat),
47                                       cl::desc("Alias for -output-format"),
48                                       cl::sub(Convert));
49 static cl::opt<std::string>
50     ConvertOutput("output", cl::value_desc("output file"), cl::init("-"),
51                   cl::desc("output file; use '-' for stdout"),
52                   cl::sub(Convert));
53 static cl::alias ConvertOutput2("o", cl::aliasopt(ConvertOutput),
54                                 cl::desc("Alias for -output"),
55                                 cl::sub(Convert));
56 
57 static cl::opt<bool>
58     ConvertSymbolize("symbolize",
59                      cl::desc("symbolize function ids from the input log"),
60                      cl::init(false), cl::sub(Convert));
61 static cl::alias ConvertSymbolize2("y", cl::aliasopt(ConvertSymbolize),
62                                    cl::desc("Alias for -symbolize"),
63                                    cl::sub(Convert));
64 
65 static cl::opt<std::string>
66     ConvertInstrMap("instr_map",
67                     cl::desc("binary with the instrumentation map, or "
68                              "a separate instrumentation map"),
69                     cl::value_desc("binary with xray_instr_map"),
70                     cl::sub(Convert), cl::init(""));
71 static cl::alias ConvertInstrMap2("m", cl::aliasopt(ConvertInstrMap),
72                                   cl::desc("Alias for -instr_map"),
73                                   cl::sub(Convert));
74 static cl::opt<bool> ConvertSortInput(
75     "sort",
76     cl::desc("determines whether to sort input log records by timestamp"),
77     cl::sub(Convert), cl::init(true));
78 static cl::alias ConvertSortInput2("s", cl::aliasopt(ConvertSortInput),
79                                    cl::desc("Alias for -sort"),
80                                    cl::sub(Convert));
81 
82 using llvm::yaml::Output;
83 
exportAsYAML(const Trace & Records,raw_ostream & OS)84 void TraceConverter::exportAsYAML(const Trace &Records, raw_ostream &OS) {
85   YAMLXRayTrace Trace;
86   const auto &FH = Records.getFileHeader();
87   Trace.Header = {FH.Version, FH.Type, FH.ConstantTSC, FH.NonstopTSC,
88                   FH.CycleFrequency};
89   Trace.Records.reserve(Records.size());
90   for (const auto &R : Records) {
91     Trace.Records.push_back({R.RecordType, R.CPU, R.Type, R.FuncId,
92                              Symbolize ? FuncIdHelper.SymbolOrNumber(R.FuncId)
93                                        : llvm::to_string(R.FuncId),
94                              R.TSC, R.TId, R.PId, R.CallArgs});
95   }
96   Output Out(OS, nullptr, 0);
97   Out << Trace;
98 }
99 
exportAsRAWv1(const Trace & Records,raw_ostream & OS)100 void TraceConverter::exportAsRAWv1(const Trace &Records, raw_ostream &OS) {
101   // First write out the file header, in the correct endian-appropriate format
102   // (XRay assumes currently little endian).
103   support::endian::Writer Writer(OS, support::endianness::little);
104   const auto &FH = Records.getFileHeader();
105   Writer.write(FH.Version);
106   Writer.write(FH.Type);
107   uint32_t Bitfield{0};
108   if (FH.ConstantTSC)
109     Bitfield |= 1uL;
110   if (FH.NonstopTSC)
111     Bitfield |= 1uL << 1;
112   Writer.write(Bitfield);
113   Writer.write(FH.CycleFrequency);
114 
115   // There's 16 bytes of padding at the end of the file header.
116   static constexpr uint32_t Padding4B = 0;
117   Writer.write(Padding4B);
118   Writer.write(Padding4B);
119   Writer.write(Padding4B);
120   Writer.write(Padding4B);
121 
122   // Then write out the rest of the records, still in an endian-appropriate
123   // format.
124   for (const auto &R : Records) {
125     Writer.write(R.RecordType);
126     // The on disk naive raw format uses 8 bit CPUs, but the record has 16.
127     // There's no choice but truncation.
128     Writer.write(static_cast<uint8_t>(R.CPU));
129     switch (R.Type) {
130     case RecordTypes::ENTER:
131     case RecordTypes::ENTER_ARG:
132       Writer.write(uint8_t{0});
133       break;
134     case RecordTypes::EXIT:
135       Writer.write(uint8_t{1});
136       break;
137     case RecordTypes::TAIL_EXIT:
138       Writer.write(uint8_t{2});
139       break;
140     }
141     Writer.write(R.FuncId);
142     Writer.write(R.TSC);
143     Writer.write(R.TId);
144 
145     if (FH.Version >= 3)
146       Writer.write(R.PId);
147     else
148       Writer.write(Padding4B);
149 
150     Writer.write(Padding4B);
151     Writer.write(Padding4B);
152   }
153 }
154 
155 namespace {
156 
157 // A structure that allows building a dictionary of stack ids for the Chrome
158 // trace event format.
159 struct StackIdData {
160   // Each Stack of function calls has a unique ID.
161   unsigned id;
162 
163   // Bookkeeping so that IDs can be maintained uniquely across threads.
164   // Traversal keeps sibling pointers to other threads stacks. This is helpful
165   // to determine when a thread encounters a new stack and should assign a new
166   // unique ID.
167   SmallVector<TrieNode<StackIdData> *, 4> siblings;
168 };
169 
170 using StackTrieNode = TrieNode<StackIdData>;
171 
172 // A helper function to find the sibling nodes for an encountered function in a
173 // thread of execution. Relies on the invariant that each time a new node is
174 // traversed in a thread, sibling bidirectional pointers are maintained.
175 SmallVector<StackTrieNode *, 4>
findSiblings(StackTrieNode * parent,int32_t FnId,uint32_t TId,const DenseMap<uint32_t,SmallVector<StackTrieNode *,4>> & StackRootsByThreadId)176 findSiblings(StackTrieNode *parent, int32_t FnId, uint32_t TId,
177              const DenseMap<uint32_t, SmallVector<StackTrieNode *, 4>>
178                  &StackRootsByThreadId) {
179 
180   SmallVector<StackTrieNode *, 4> Siblings{};
181 
182   if (parent == nullptr) {
183     for (auto map_iter : StackRootsByThreadId) {
184       // Only look for siblings in other threads.
185       if (map_iter.first != TId)
186         for (auto node_iter : map_iter.second) {
187           if (node_iter->FuncId == FnId)
188             Siblings.push_back(node_iter);
189         }
190     }
191     return Siblings;
192   }
193 
194   for (auto *ParentSibling : parent->ExtraData.siblings)
195     for (auto node_iter : ParentSibling->Callees)
196       if (node_iter->FuncId == FnId)
197         Siblings.push_back(node_iter);
198 
199   return Siblings;
200 }
201 
202 // Given a function being invoked in a thread with id TId, finds and returns the
203 // StackTrie representing the function call stack. If no node exists, creates
204 // the node. Assigns unique IDs to stacks newly encountered among all threads
205 // and keeps sibling links up to when creating new nodes.
findOrCreateStackNode(StackTrieNode * Parent,int32_t FuncId,uint32_t TId,DenseMap<uint32_t,SmallVector<StackTrieNode *,4>> & StackRootsByThreadId,DenseMap<unsigned,StackTrieNode * > & StacksByStackId,unsigned * id_counter,std::forward_list<StackTrieNode> & NodeStore)206 StackTrieNode *findOrCreateStackNode(
207     StackTrieNode *Parent, int32_t FuncId, uint32_t TId,
208     DenseMap<uint32_t, SmallVector<StackTrieNode *, 4>> &StackRootsByThreadId,
209     DenseMap<unsigned, StackTrieNode *> &StacksByStackId, unsigned *id_counter,
210     std::forward_list<StackTrieNode> &NodeStore) {
211   SmallVector<StackTrieNode *, 4> &ParentCallees =
212       Parent == nullptr ? StackRootsByThreadId[TId] : Parent->Callees;
213   auto match = find_if(ParentCallees, [FuncId](StackTrieNode *ParentCallee) {
214     return FuncId == ParentCallee->FuncId;
215   });
216   if (match != ParentCallees.end())
217     return *match;
218 
219   SmallVector<StackTrieNode *, 4> siblings =
220       findSiblings(Parent, FuncId, TId, StackRootsByThreadId);
221   if (siblings.empty()) {
222     NodeStore.push_front({FuncId, Parent, {}, {(*id_counter)++, {}}});
223     StackTrieNode *CurrentStack = &NodeStore.front();
224     StacksByStackId[*id_counter - 1] = CurrentStack;
225     ParentCallees.push_back(CurrentStack);
226     return CurrentStack;
227   }
228   unsigned stack_id = siblings[0]->ExtraData.id;
229   NodeStore.push_front({FuncId, Parent, {}, {stack_id, std::move(siblings)}});
230   StackTrieNode *CurrentStack = &NodeStore.front();
231   for (auto *sibling : CurrentStack->ExtraData.siblings)
232     sibling->ExtraData.siblings.push_back(CurrentStack);
233   ParentCallees.push_back(CurrentStack);
234   return CurrentStack;
235 }
236 
writeTraceViewerRecord(uint16_t Version,raw_ostream & OS,int32_t FuncId,uint32_t TId,uint32_t PId,bool Symbolize,const FuncIdConversionHelper & FuncIdHelper,double EventTimestampUs,const StackTrieNode & StackCursor,StringRef FunctionPhenotype)237 void writeTraceViewerRecord(uint16_t Version, raw_ostream &OS, int32_t FuncId,
238                             uint32_t TId, uint32_t PId, bool Symbolize,
239                             const FuncIdConversionHelper &FuncIdHelper,
240                             double EventTimestampUs,
241                             const StackTrieNode &StackCursor,
242                             StringRef FunctionPhenotype) {
243   OS << "    ";
244   if (Version >= 3) {
245     OS << llvm::formatv(
246         R"({ "name" : "{0}", "ph" : "{1}", "tid" : "{2}", "pid" : "{3}", )"
247         R"("ts" : "{4:f4}", "sf" : "{5}" })",
248         (Symbolize ? FuncIdHelper.SymbolOrNumber(FuncId)
249                    : llvm::to_string(FuncId)),
250         FunctionPhenotype, TId, PId, EventTimestampUs,
251         StackCursor.ExtraData.id);
252   } else {
253     OS << llvm::formatv(
254         R"({ "name" : "{0}", "ph" : "{1}", "tid" : "{2}", "pid" : "1", )"
255         R"("ts" : "{3:f3}", "sf" : "{4}" })",
256         (Symbolize ? FuncIdHelper.SymbolOrNumber(FuncId)
257                    : llvm::to_string(FuncId)),
258         FunctionPhenotype, TId, EventTimestampUs, StackCursor.ExtraData.id);
259   }
260 }
261 
262 } // namespace
263 
exportAsChromeTraceEventFormat(const Trace & Records,raw_ostream & OS)264 void TraceConverter::exportAsChromeTraceEventFormat(const Trace &Records,
265                                                     raw_ostream &OS) {
266   const auto &FH = Records.getFileHeader();
267   auto Version = FH.Version;
268   auto CycleFreq = FH.CycleFrequency;
269 
270   unsigned id_counter = 0;
271 
272   OS << "{\n  \"traceEvents\": [";
273   DenseMap<uint32_t, StackTrieNode *> StackCursorByThreadId{};
274   DenseMap<uint32_t, SmallVector<StackTrieNode *, 4>> StackRootsByThreadId{};
275   DenseMap<unsigned, StackTrieNode *> StacksByStackId{};
276   std::forward_list<StackTrieNode> NodeStore{};
277   int loop_count = 0;
278   for (const auto &R : Records) {
279     if (loop_count++ == 0)
280       OS << "\n";
281     else
282       OS << ",\n";
283 
284     // Chrome trace event format always wants data in micros.
285     // CyclesPerMicro = CycleHertz / 10^6
286     // TSC / CyclesPerMicro == TSC * 10^6 / CycleHertz == MicroTimestamp
287     // Could lose some precision here by converting the TSC to a double to
288     // multiply by the period in micros. 52 bit mantissa is a good start though.
289     // TODO: Make feature request to Chrome Trace viewer to accept ticks and a
290     // frequency or do some more involved calculation to avoid dangers of
291     // conversion.
292     double EventTimestampUs = double(1000000) / CycleFreq * double(R.TSC);
293     StackTrieNode *&StackCursor = StackCursorByThreadId[R.TId];
294     switch (R.Type) {
295     case RecordTypes::ENTER:
296     case RecordTypes::ENTER_ARG:
297       StackCursor = findOrCreateStackNode(StackCursor, R.FuncId, R.TId,
298                                           StackRootsByThreadId, StacksByStackId,
299                                           &id_counter, NodeStore);
300       // Each record is represented as a json dictionary with function name,
301       // type of B for begin or E for end, thread id, process id,
302       // timestamp in microseconds, and a stack frame id. The ids are logged
303       // in an id dictionary after the events.
304       writeTraceViewerRecord(Version, OS, R.FuncId, R.TId, R.PId, Symbolize,
305                              FuncIdHelper, EventTimestampUs, *StackCursor, "B");
306       break;
307     case RecordTypes::EXIT:
308     case RecordTypes::TAIL_EXIT:
309       // No entries to record end for.
310       if (StackCursor == nullptr)
311         break;
312       // Should we emit an END record anyway or account this condition?
313       // (And/Or in loop termination below)
314       StackTrieNode *PreviousCursor = nullptr;
315       do {
316         if (PreviousCursor != nullptr) {
317           OS << ",\n";
318         }
319         writeTraceViewerRecord(Version, OS, StackCursor->FuncId, R.TId, R.PId,
320                                Symbolize, FuncIdHelper, EventTimestampUs,
321                                *StackCursor, "E");
322         PreviousCursor = StackCursor;
323         StackCursor = StackCursor->Parent;
324       } while (PreviousCursor->FuncId != R.FuncId && StackCursor != nullptr);
325       break;
326     }
327   }
328   OS << "\n  ],\n"; // Close the Trace Events array.
329   OS << "  "
330      << "\"displayTimeUnit\": \"ns\",\n";
331 
332   // The stackFrames dictionary substantially reduces size of the output file by
333   // avoiding repeating the entire call stack of function names for each entry.
334   OS << R"(  "stackFrames": {)";
335   int stack_frame_count = 0;
336   for (auto map_iter : StacksByStackId) {
337     if (stack_frame_count++ == 0)
338       OS << "\n";
339     else
340       OS << ",\n";
341     OS << "    ";
342     OS << llvm::formatv(
343         R"("{0}" : { "name" : "{1}")", map_iter.first,
344         (Symbolize ? FuncIdHelper.SymbolOrNumber(map_iter.second->FuncId)
345                    : llvm::to_string(map_iter.second->FuncId)));
346     if (map_iter.second->Parent != nullptr)
347       OS << llvm::formatv(R"(, "parent": "{0}")",
348                           map_iter.second->Parent->ExtraData.id);
349     OS << " }";
350   }
351   OS << "\n  }\n"; // Close the stack frames map.
352   OS << "}\n";     // Close the JSON entry.
353 }
354 
355 namespace llvm {
356 namespace xray {
357 
__anon8d442b510302() 358 static CommandRegistration Unused(&Convert, []() -> Error {
359   // FIXME: Support conversion to BINARY when upgrading XRay trace versions.
360   InstrumentationMap Map;
361   if (!ConvertInstrMap.empty()) {
362     auto InstrumentationMapOrError = loadInstrumentationMap(ConvertInstrMap);
363     if (!InstrumentationMapOrError)
364       return joinErrors(make_error<StringError>(
365                             Twine("Cannot open instrumentation map '") +
366                                 ConvertInstrMap + "'",
367                             std::make_error_code(std::errc::invalid_argument)),
368                         InstrumentationMapOrError.takeError());
369     Map = std::move(*InstrumentationMapOrError);
370   }
371 
372   const auto &FunctionAddresses = Map.getFunctionAddresses();
373   symbolize::LLVMSymbolizer::Options Opts(
374       symbolize::FunctionNameKind::LinkageName, true, true, false, "");
375   symbolize::LLVMSymbolizer Symbolizer(Opts);
376   llvm::xray::FuncIdConversionHelper FuncIdHelper(ConvertInstrMap, Symbolizer,
377                                                   FunctionAddresses);
378   llvm::xray::TraceConverter TC(FuncIdHelper, ConvertSymbolize);
379   std::error_code EC;
380   raw_fd_ostream OS(ConvertOutput, EC,
381                     ConvertOutputFormat == ConvertFormats::BINARY
382                         ? sys::fs::OpenFlags::F_None
383                         : sys::fs::OpenFlags::F_Text);
384   if (EC)
385     return make_error<StringError>(
386         Twine("Cannot open file '") + ConvertOutput + "' for writing.", EC);
387 
388   auto TraceOrErr = loadTraceFile(ConvertInput, ConvertSortInput);
389   if (!TraceOrErr)
390     return joinErrors(
391         make_error<StringError>(
392             Twine("Failed loading input file '") + ConvertInput + "'.",
393             std::make_error_code(std::errc::executable_format_error)),
394         TraceOrErr.takeError());
395 
396   auto &T = *TraceOrErr;
397   switch (ConvertOutputFormat) {
398   case ConvertFormats::YAML:
399     TC.exportAsYAML(T, OS);
400     break;
401   case ConvertFormats::BINARY:
402     TC.exportAsRAWv1(T, OS);
403     break;
404   case ConvertFormats::CHROME_TRACE_EVENT:
405     TC.exportAsChromeTraceEventFormat(T, OS);
406     break;
407   }
408   return Error::success();
409 });
410 
411 } // namespace xray
412 } // namespace llvm
413