OProfileJITEventListener.cpp revision 36b56886974eae4f9c5ebc96befd3e7bfe5de338 
1//===-- OProfileJITEventListener.cpp - Tell OProfile about JITted code ----===//
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// This file defines a JITEventListener object that uses OProfileWrapper to tell
11// oprofile about JITted functions, including source line information.
12//
13//===----------------------------------------------------------------------===//
14
15#include "llvm/Config/config.h"
16#include "llvm/ExecutionEngine/JITEventListener.h"
17
18#define DEBUG_TYPE "oprofile-jit-event-listener"
19#include "llvm/IR/DebugInfo.h"
20#include "llvm/IR/Function.h"
21#include "llvm/CodeGen/MachineFunction.h"
22#include "llvm/ExecutionEngine/ObjectImage.h"
23#include "llvm/ExecutionEngine/OProfileWrapper.h"
24#include "llvm/Object/ObjectFile.h"
25#include "llvm/Support/Debug.h"
26#include "llvm/Support/raw_ostream.h"
27#include "llvm/Support/Errno.h"
28#include "EventListenerCommon.h"
29
30#include <dirent.h>
31#include <fcntl.h>
32
33using namespace llvm;
34using namespace llvm::jitprofiling;
35
36namespace {
37
38class OProfileJITEventListener : public JITEventListener {
39  OProfileWrapper& Wrapper;
40
41  void initialize();
42
43public:
44  OProfileJITEventListener(OProfileWrapper& LibraryWrapper)
45  : Wrapper(LibraryWrapper) {
46    initialize();
47  }
48
49  ~OProfileJITEventListener();
50
51  virtual void NotifyFunctionEmitted(const Function &F,
52                                void *FnStart, size_t FnSize,
53                                const JITEvent_EmittedFunctionDetails &Details);
54
55  virtual void NotifyFreeingMachineCode(void *OldPtr);
56
57  virtual void NotifyObjectEmitted(const ObjectImage &Obj);
58
59  virtual void NotifyFreeingObject(const ObjectImage &Obj);
60};
61
62void OProfileJITEventListener::initialize() {
63  if (!Wrapper.op_open_agent()) {
64    const std::string err_str = sys::StrError();
65    DEBUG(dbgs() << "Failed to connect to OProfile agent: " << err_str << "\n");
66  } else {
67    DEBUG(dbgs() << "Connected to OProfile agent.\n");
68  }
69}
70
71OProfileJITEventListener::~OProfileJITEventListener() {
72  if (Wrapper.isAgentAvailable()) {
73    if (Wrapper.op_close_agent() == -1) {
74      const std::string err_str = sys::StrError();
75      DEBUG(dbgs() << "Failed to disconnect from OProfile agent: "
76                   << err_str << "\n");
77    } else {
78      DEBUG(dbgs() << "Disconnected from OProfile agent.\n");
79    }
80  }
81}
82
83static debug_line_info LineStartToOProfileFormat(
84    const MachineFunction &MF, FilenameCache &Filenames,
85    uintptr_t Address, DebugLoc Loc) {
86  debug_line_info Result;
87  Result.vma = Address;
88  Result.lineno = Loc.getLine();
89  Result.filename = Filenames.getFilename(
90    Loc.getScope(MF.getFunction()->getContext()));
91  DEBUG(dbgs() << "Mapping " << reinterpret_cast<void*>(Result.vma) << " to "
92               << Result.filename << ":" << Result.lineno << "\n");
93  return Result;
94}
95
96// Adds the just-emitted function to the symbol table.
97void OProfileJITEventListener::NotifyFunctionEmitted(
98    const Function &F, void *FnStart, size_t FnSize,
99    const JITEvent_EmittedFunctionDetails &Details) {
100  assert(F.hasName() && FnStart != 0 && "Bad symbol to add");
101  if (Wrapper.op_write_native_code(F.getName().data(),
102                           reinterpret_cast<uint64_t>(FnStart),
103                           FnStart, FnSize) == -1) {
104    DEBUG(dbgs() << "Failed to tell OProfile about native function "
105          << F.getName() << " at ["
106          << FnStart << "-" << ((char*)FnStart + FnSize) << "]\n");
107    return;
108  }
109
110  if (!Details.LineStarts.empty()) {
111    // Now we convert the line number information from the address/DebugLoc
112    // format in Details to the address/filename/lineno format that OProfile
113    // expects.  Note that OProfile 0.9.4 has a bug that causes it to ignore
114    // line numbers for addresses above 4G.
115    FilenameCache Filenames;
116    std::vector<debug_line_info> LineInfo;
117    LineInfo.reserve(1 + Details.LineStarts.size());
118
119    DebugLoc FirstLoc = Details.LineStarts[0].Loc;
120    assert(!FirstLoc.isUnknown()
121           && "LineStarts should not contain unknown DebugLocs");
122    MDNode *FirstLocScope = FirstLoc.getScope(F.getContext());
123    DISubprogram FunctionDI = getDISubprogram(FirstLocScope);
124    if (FunctionDI.Verify()) {
125      // If we have debug info for the function itself, use that as the line
126      // number of the first several instructions.  Otherwise, after filling
127      // LineInfo, we'll adjust the address of the first line number to point at
128      // the start of the function.
129      debug_line_info line_info;
130      line_info.vma = reinterpret_cast<uintptr_t>(FnStart);
131      line_info.lineno = FunctionDI.getLineNumber();
132      line_info.filename = Filenames.getFilename(FirstLocScope);
133      LineInfo.push_back(line_info);
134    }
135
136    for (std::vector<EmittedFunctionDetails::LineStart>::const_iterator
137           I = Details.LineStarts.begin(), E = Details.LineStarts.end();
138         I != E; ++I) {
139      LineInfo.push_back(LineStartToOProfileFormat(
140                           *Details.MF, Filenames, I->Address, I->Loc));
141    }
142
143    // In case the function didn't have line info of its own, adjust the first
144    // line info's address to include the start of the function.
145    LineInfo[0].vma = reinterpret_cast<uintptr_t>(FnStart);
146
147    if (Wrapper.op_write_debug_line_info(FnStart, LineInfo.size(),
148                                      &*LineInfo.begin()) == -1) {
149      DEBUG(dbgs()
150            << "Failed to tell OProfile about line numbers for native function "
151            << F.getName() << " at ["
152            << FnStart << "-" << ((char*)FnStart + FnSize) << "]\n");
153    }
154  }
155}
156
157// Removes the being-deleted function from the symbol table.
158void OProfileJITEventListener::NotifyFreeingMachineCode(void *FnStart) {
159  assert(FnStart && "Invalid function pointer");
160  if (Wrapper.op_unload_native_code(reinterpret_cast<uint64_t>(FnStart)) == -1) {
161    DEBUG(dbgs()
162          << "Failed to tell OProfile about unload of native function at "
163          << FnStart << "\n");
164  }
165}
166
167void OProfileJITEventListener::NotifyObjectEmitted(const ObjectImage &Obj) {
168  if (!Wrapper.isAgentAvailable()) {
169    return;
170  }
171
172  // Use symbol info to iterate functions in the object.
173  error_code ec;
174  for (object::symbol_iterator I = Obj.begin_symbols(),
175                               E = Obj.end_symbols();
176                        I != E && !ec;
177                        I.increment(ec)) {
178    object::SymbolRef::Type SymType;
179    if (I->getType(SymType)) continue;
180    if (SymType == object::SymbolRef::ST_Function) {
181      StringRef  Name;
182      uint64_t   Addr;
183      uint64_t   Size;
184      if (I->getName(Name)) continue;
185      if (I->getAddress(Addr)) continue;
186      if (I->getSize(Size)) continue;
187
188      if (Wrapper.op_write_native_code(Name.data(), Addr, (void*)Addr, Size)
189                        == -1) {
190        DEBUG(dbgs() << "Failed to tell OProfile about native function "
191          << Name << " at ["
192          << (void*)Addr << "-" << ((char*)Addr + Size) << "]\n");
193        continue;
194      }
195      // TODO: support line number info (similar to IntelJITEventListener.cpp)
196    }
197  }
198}
199
200void OProfileJITEventListener::NotifyFreeingObject(const ObjectImage &Obj) {
201  if (!Wrapper.isAgentAvailable()) {
202    return;
203  }
204
205  // Use symbol info to iterate functions in the object.
206  error_code ec;
207  for (object::symbol_iterator I = Obj.begin_symbols(),
208                               E = Obj.end_symbols();
209                        I != E && !ec;
210                        I.increment(ec)) {
211    object::SymbolRef::Type SymType;
212    if (I->getType(SymType)) continue;
213    if (SymType == object::SymbolRef::ST_Function) {
214      uint64_t   Addr;
215      if (I->getAddress(Addr)) continue;
216
217      if (Wrapper.op_unload_native_code(Addr) == -1) {
218        DEBUG(dbgs()
219          << "Failed to tell OProfile about unload of native function at "
220          << (void*)Addr << "\n");
221        continue;
222      }
223    }
224  }
225}
226
227}  // anonymous namespace.
228
229namespace llvm {
230JITEventListener *JITEventListener::createOProfileJITEventListener() {
231  static std::unique_ptr<OProfileWrapper> JITProfilingWrapper(
232      new OProfileWrapper);
233  return new OProfileJITEventListener(*JITProfilingWrapper);
234}
235
236// for testing
237JITEventListener *JITEventListener::createOProfileJITEventListener(
238                                      OProfileWrapper* TestImpl) {
239  return new OProfileJITEventListener(*TestImpl);
240}
241
242} // namespace llvm
243
244