1 //===-- IntelJITEventListener.cpp - Tell Intel profiler about JITed code --===//
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 // This file defines a JITEventListener object to tell Intel(R) VTune(TM)
10 // Amplifier XE 2011 about JITted functions.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "IntelJITEventsWrapper.h"
15 #include "ittnotify.h"
16 #include "llvm-c/ExecutionEngine.h"
17 #include "llvm/ADT/DenseMap.h"
18 #include "llvm/CodeGen/MachineFunction.h"
19 #include "llvm/Config/config.h"
20 #include "llvm/DebugInfo/DIContext.h"
21 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
22 #include "llvm/ExecutionEngine/JITEventListener.h"
23 #include "llvm/IR/DebugInfo.h"
24 #include "llvm/IR/Function.h"
25 #include "llvm/IR/Metadata.h"
26 #include "llvm/IR/ValueHandle.h"
27 #include "llvm/Object/ELFObjectFile.h"
28 #include "llvm/Object/ObjectFile.h"
29 #include "llvm/Object/SymbolSize.h"
30 #include "llvm/Support/Debug.h"
31 #include "llvm/Support/Errno.h"
32 #include "llvm/Support/raw_ostream.h"
33 
34 using namespace llvm;
35 using namespace llvm::object;
36 
37 #define DEBUG_TYPE "amplifier-jit-event-listener"
38 
39 namespace {
40 
41 class IntelIttnotifyInfo {
42   std::string ModuleName;
43   std::vector<std::string> SectionNamesVector;
44   std::vector<__itt_section_info> SectionInfoVector;
45   __itt_module_object *ModuleObject;
46   IntelJITEventsWrapper &WrapperRef;
47 
48 public:
49   IntelIttnotifyInfo(IntelJITEventsWrapper &Wrapper)
50       : ModuleObject(NULL), WrapperRef(Wrapper){};
51   ~IntelIttnotifyInfo() { delete ModuleObject; };
52 
53   void setModuleName(const char *Name) { ModuleName = std::string(Name); }
54 
55   const char *getModuleName() { return ModuleName.c_str(); }
56 
57   void setModuleObject(__itt_module_object *ModuleObj) {
58     ModuleObject = ModuleObj;
59   }
60 
61   __itt_module_object *getModuleObject() { return ModuleObject; }
62 
63   __itt_section_info *getSectionInfoVectorBegin() {
64     if (SectionInfoVector.size())
65       return &SectionInfoVector[0];
66     return NULL;
67   }
68 
69   void reportSection(llvm::IttEventType EventType, const char *SectionName,
70                      unsigned int SectionSize) {
71     WrapperRef.iJitIttNotifyInfo(EventType, SectionName, SectionSize);
72   }
73 
74   int fillSectionInformation(const ObjectFile &Obj,
75                              const RuntimeDyld::LoadedObjectInfo &L) {
76 
77     int SectionCounter = 0;
78 
79     for (auto &Section : Obj.sections()) {
80       uint64_t SectionLoadAddr = L.getSectionLoadAddress(Section);
81       if (SectionLoadAddr) {
82         object::ELFSectionRef ElfSection(Section);
83 
84         __itt_section_info SectionInfo;
85         memset(&SectionInfo, 0, sizeof(SectionInfo));
86         SectionInfo.start_addr = reinterpret_cast<void *>(SectionLoadAddr);
87         SectionInfo.file_offset = ElfSection.getOffset();
88         SectionInfo.flags = ElfSection.getFlags();
89 
90         StringRef SectionName("");
91         auto SectionNameOrError = ElfSection.getName();
92         if (SectionNameOrError)
93           SectionName = *SectionNameOrError;
94 
95         SectionNamesVector.push_back(SectionName.str());
96         SectionInfo.size = ElfSection.getSize();
97         reportSection(llvm::LoadBinarySection, SectionName.str().c_str(),
98                       SectionInfo.size);
99 
100         if (ElfSection.isBSS()) {
101           SectionInfo.type = itt_section_type_bss;
102         } else if (ElfSection.isData()) {
103           SectionInfo.type = itt_section_type_data;
104         } else if (ElfSection.isText()) {
105           SectionInfo.type = itt_section_type_text;
106         }
107         SectionInfoVector.push_back(SectionInfo);
108         ++SectionCounter;
109       }
110     }
111     // Hereinafter: don't change SectionNamesVector content to avoid vector
112     // reallocation - reallocation invalidates all the references, pointers, and
113     // iterators referring to the elements in the sequence.
114     for (int I = 0; I < SectionCounter; ++I) {
115       SectionInfoVector[I].name = SectionNamesVector[I].c_str();
116     }
117     return SectionCounter;
118   }
119 };
120 
121 class IntelJITEventListener : public JITEventListener {
122   typedef DenseMap<void*, unsigned int> MethodIDMap;
123 
124   std::unique_ptr<IntelJITEventsWrapper> Wrapper;
125   MethodIDMap MethodIDs;
126 
127   typedef SmallVector<const void *, 64> MethodAddressVector;
128   typedef DenseMap<const void *, MethodAddressVector>  ObjectMap;
129 
130   ObjectMap  LoadedObjectMap;
131   std::map<ObjectKey, OwningBinary<ObjectFile>> DebugObjects;
132 
133   std::map<ObjectKey, std::unique_ptr<IntelIttnotifyInfo>> KeyToIttnotify;
134 
135 public:
136   IntelJITEventListener(IntelJITEventsWrapper* libraryWrapper) {
137       Wrapper.reset(libraryWrapper);
138   }
139 
140   ~IntelJITEventListener() {
141   }
142 
143   void notifyObjectLoaded(ObjectKey Key, const ObjectFile &Obj,
144                           const RuntimeDyld::LoadedObjectInfo &L) override;
145 
146   void notifyFreeingObject(ObjectKey Key) override;
147 };
148 
149 static LineNumberInfo DILineInfoToIntelJITFormat(uintptr_t StartAddress,
150                                                  uintptr_t Address,
151                                                  DILineInfo Line) {
152   LineNumberInfo Result;
153 
154   Result.Offset = Address - StartAddress;
155   Result.LineNumber = Line.Line;
156 
157   return Result;
158 }
159 
160 static iJIT_Method_Load FunctionDescToIntelJITFormat(
161     IntelJITEventsWrapper& Wrapper,
162     const char* FnName,
163     uintptr_t FnStart,
164     size_t FnSize) {
165   iJIT_Method_Load Result;
166   memset(&Result, 0, sizeof(iJIT_Method_Load));
167 
168   Result.method_id = Wrapper.iJIT_GetNewMethodID();
169   Result.method_name = const_cast<char*>(FnName);
170   Result.method_load_address = reinterpret_cast<void*>(FnStart);
171   Result.method_size = FnSize;
172 
173   Result.class_id = 0;
174   Result.class_file_name = NULL;
175   Result.user_data = NULL;
176   Result.user_data_size = 0;
177   Result.env = iJDE_JittingAPI;
178 
179   return Result;
180 }
181 
182 int getBackwardCompatibilityMode() {
183 
184   char *BackwardCompatibilityEnv = getenv("INTEL_JIT_BACKWARD_COMPATIBILITY");
185   int BackwardCompatibilityMode = 0;
186   if (BackwardCompatibilityEnv) {
187     StringRef(BackwardCompatibilityEnv)
188         .getAsInteger(10, BackwardCompatibilityMode);
189   }
190   return BackwardCompatibilityMode;
191 }
192 
193 void IntelJITEventListener::notifyObjectLoaded(
194     ObjectKey Key, const ObjectFile &Obj,
195     const RuntimeDyld::LoadedObjectInfo &L) {
196 
197   int BackwardCompatibilityMode = getBackwardCompatibilityMode();
198   if (BackwardCompatibilityMode == 0) {
199     if (Obj.isELF()) {
200       std::unique_ptr<IntelIttnotifyInfo> ModuleIttnotify =
201           std::make_unique<IntelIttnotifyInfo>(*Wrapper);
202       ModuleIttnotify->setModuleName(
203           StringRef(llvm::utohexstr(
204                         MD5Hash(Obj.getMemoryBufferRef().getBuffer()), true))
205               .str()
206               .c_str());
207 
208       __itt_module_object *ModuleObject = new __itt_module_object();
209       ModuleObject->module_name = ModuleIttnotify->getModuleName();
210       ModuleObject->module_size = Obj.getMemoryBufferRef().getBufferSize();
211       Wrapper->iJitIttNotifyInfo(llvm::LoadBinaryModule,
212                                  ModuleObject->module_name,
213                                  ModuleObject->module_size);
214       ModuleObject->module_type = __itt_module_type_elf;
215       ModuleObject->section_number =
216           ModuleIttnotify->fillSectionInformation(Obj, L);
217       ModuleObject->module_buffer =
218           (void *)const_cast<char *>(Obj.getMemoryBufferRef().getBufferStart());
219       ModuleObject->module_id =
220           __itt_id_make((void *)&(*ModuleObject), ModuleObject->module_size);
221       ModuleObject->section_array =
222           ModuleIttnotify->getSectionInfoVectorBegin();
223       ModuleIttnotify->setModuleObject(ModuleObject);
224 
225       __itt_module_load_with_sections(ModuleObject);
226 
227       KeyToIttnotify[Key] = std::move(ModuleIttnotify);
228     }
229   } else if (BackwardCompatibilityMode == 1) {
230 
231     OwningBinary<ObjectFile> DebugObjOwner = L.getObjectForDebug(Obj);
232     const ObjectFile *DebugObj = DebugObjOwner.getBinary();
233     if (!DebugObj)
234       return;
235 
236     // Get the address of the object image for use as a unique identifier
237     const void *ObjData = DebugObj->getData().data();
238     std::unique_ptr<DIContext> Context = DWARFContext::create(*DebugObj);
239     MethodAddressVector Functions;
240 
241     // Use symbol info to iterate functions in the object.
242     for (const std::pair<SymbolRef, uint64_t> &P :
243          computeSymbolSizes(*DebugObj)) {
244       SymbolRef Sym = P.first;
245       std::vector<LineNumberInfo> LineInfo;
246       std::string SourceFileName;
247 
248       Expected<SymbolRef::Type> SymTypeOrErr = Sym.getType();
249       if (!SymTypeOrErr) {
250         // TODO: Actually report errors helpfully.
251         consumeError(SymTypeOrErr.takeError());
252         continue;
253       }
254       SymbolRef::Type SymType = *SymTypeOrErr;
255       if (SymType != SymbolRef::ST_Function)
256         continue;
257 
258       Expected<StringRef> Name = Sym.getName();
259       if (!Name) {
260         // TODO: Actually report errors helpfully.
261         consumeError(Name.takeError());
262         continue;
263       }
264 
265       Expected<uint64_t> AddrOrErr = Sym.getAddress();
266       if (!AddrOrErr) {
267         // TODO: Actually report errors helpfully.
268         consumeError(AddrOrErr.takeError());
269         continue;
270       }
271       uint64_t Addr = *AddrOrErr;
272       uint64_t Size = P.second;
273 
274       auto SecOrErr = Sym.getSection();
275       if (!SecOrErr) {
276         // TODO: Actually report errors helpfully.
277         consumeError(SecOrErr.takeError());
278         continue;
279       }
280       object::section_iterator Sec = *SecOrErr;
281       if (Sec == Obj.section_end())
282         continue;
283       uint64_t Index = Sec->getIndex();
284 
285       // Record this address in a local vector
286       Functions.push_back((void *)Addr);
287 
288       // Build the function loaded notification message
289       iJIT_Method_Load FunctionMessage =
290           FunctionDescToIntelJITFormat(*Wrapper, Name->data(), Addr, Size);
291       DILineInfoTable Lines =
292           Context->getLineInfoForAddressRange({Addr, Index}, Size);
293       DILineInfoTable::iterator Begin = Lines.begin();
294       DILineInfoTable::iterator End = Lines.end();
295       for (DILineInfoTable::iterator It = Begin; It != End; ++It) {
296         LineInfo.push_back(
297             DILineInfoToIntelJITFormat((uintptr_t)Addr, It->first, It->second));
298       }
299       if (LineInfo.size() == 0) {
300         FunctionMessage.source_file_name = 0;
301         FunctionMessage.line_number_size = 0;
302         FunctionMessage.line_number_table = 0;
303       } else {
304         // Source line information for the address range is provided as
305         // a code offset for the start of the corresponding sub-range and
306         // a source line. JIT API treats offsets in LineNumberInfo structures
307         // as the end of the corresponding code region. The start of the code
308         // is taken from the previous element. Need to shift the elements.
309 
310         LineNumberInfo last = LineInfo.back();
311         last.Offset = FunctionMessage.method_size;
312         LineInfo.push_back(last);
313         for (size_t i = LineInfo.size() - 2; i > 0; --i)
314           LineInfo[i].LineNumber = LineInfo[i - 1].LineNumber;
315 
316         SourceFileName = Lines.front().second.FileName;
317         FunctionMessage.source_file_name =
318             const_cast<char *>(SourceFileName.c_str());
319         FunctionMessage.line_number_size = LineInfo.size();
320         FunctionMessage.line_number_table = &*LineInfo.begin();
321       }
322 
323       Wrapper->iJIT_NotifyEvent(iJVM_EVENT_TYPE_METHOD_LOAD_FINISHED,
324                                 &FunctionMessage);
325       MethodIDs[(void *)Addr] = FunctionMessage.method_id;
326     }
327 
328     // To support object unload notification, we need to keep a list of
329     // registered function addresses for each loaded object.  We will
330     // use the MethodIDs map to get the registered ID for each function.
331     LoadedObjectMap[ObjData] = Functions;
332     DebugObjects[Key] = std::move(DebugObjOwner);
333   }
334 }
335 
336 void IntelJITEventListener::notifyFreeingObject(ObjectKey Key) {
337 
338   int BackwardCompatibilityMode = getBackwardCompatibilityMode();
339   if (BackwardCompatibilityMode == 0) {
340     if (KeyToIttnotify.find(Key) == KeyToIttnotify.end())
341       return;
342     __itt_module_unload_with_sections(KeyToIttnotify[Key]->getModuleObject());
343     Wrapper->iJitIttNotifyInfo(
344         llvm::UnloadBinaryModule,
345         KeyToIttnotify[Key]->getModuleObject()->module_name,
346         KeyToIttnotify[Key]->getModuleObject()->module_size);
347     KeyToIttnotify.erase(Key);
348   } else if (BackwardCompatibilityMode == 1) {
349     // This object may not have been registered with the listener. If it wasn't,
350     // bail out.
351     if (DebugObjects.find(Key) == DebugObjects.end())
352       return;
353 
354     // Get the address of the object image for use as a unique identifier
355     const ObjectFile &DebugObj = *DebugObjects[Key].getBinary();
356     const void *ObjData = DebugObj.getData().data();
357 
358     // Get the object's function list from LoadedObjectMap
359     ObjectMap::iterator OI = LoadedObjectMap.find(ObjData);
360     if (OI == LoadedObjectMap.end())
361       return;
362     MethodAddressVector &Functions = OI->second;
363 
364     // Walk the function list, unregistering each function
365     for (MethodAddressVector::iterator FI = Functions.begin(),
366                                        FE = Functions.end();
367          FI != FE; ++FI) {
368       void *FnStart = const_cast<void *>(*FI);
369       MethodIDMap::iterator MI = MethodIDs.find(FnStart);
370       if (MI != MethodIDs.end()) {
371         Wrapper->iJIT_NotifyEvent(iJVM_EVENT_TYPE_METHOD_UNLOAD_START,
372                                   &MI->second);
373         MethodIDs.erase(MI);
374       }
375     }
376 
377     // Erase the object from LoadedObjectMap
378     LoadedObjectMap.erase(OI);
379     DebugObjects.erase(Key);
380   }
381 }
382 
383 }  // anonymous namespace.
384 
385 namespace llvm {
386 JITEventListener *JITEventListener::createIntelJITEventListener() {
387   return new IntelJITEventListener(new IntelJITEventsWrapper);
388 }
389 
390 // for testing
391 JITEventListener *JITEventListener::createIntelJITEventListener(
392                                       IntelJITEventsWrapper* TestImpl) {
393   return new IntelJITEventListener(TestImpl);
394 }
395 
396 } // namespace llvm
397 
398 LLVMJITEventListenerRef LLVMCreateIntelJITEventListener(void)
399 {
400   return wrap(JITEventListener::createIntelJITEventListener());
401 }
402