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/DebugInfo.h"
20#include "llvm/Function.h"
21#include "llvm/ADT/OwningPtr.h"
22#include "llvm/CodeGen/MachineFunction.h"
23#include "llvm/ExecutionEngine/OProfileWrapper.h"
24#include "llvm/Support/Debug.h"
25#include "llvm/Support/raw_ostream.h"
26#include "llvm/Support/Errno.h"
27#include "EventListenerCommon.h"
28
29#include <dirent.h>
30#include <fcntl.h>
31
32using namespace llvm;
33using namespace llvm::jitprofiling;
34
35namespace {
36
37class OProfileJITEventListener : public JITEventListener {
38  OProfileWrapper& Wrapper;
39
40  void initialize();
41
42public:
43  OProfileJITEventListener(OProfileWrapper& LibraryWrapper)
44  : Wrapper(LibraryWrapper) {
45    initialize();
46  }
47
48  ~OProfileJITEventListener();
49
50  virtual void NotifyFunctionEmitted(const Function &F,
51                                void *FnStart, size_t FnSize,
52                                const JITEvent_EmittedFunctionDetails &Details);
53
54  virtual void NotifyFreeingMachineCode(void *OldPtr);
55};
56
57void OProfileJITEventListener::initialize() {
58  if (!Wrapper.op_open_agent()) {
59    const std::string err_str = sys::StrError();
60    DEBUG(dbgs() << "Failed to connect to OProfile agent: " << err_str << "\n");
61  } else {
62    DEBUG(dbgs() << "Connected to OProfile agent.\n");
63  }
64}
65
66OProfileJITEventListener::~OProfileJITEventListener() {
67  if (Wrapper.isAgentAvailable()) {
68    if (Wrapper.op_close_agent() == -1) {
69      const std::string err_str = sys::StrError();
70      DEBUG(dbgs() << "Failed to disconnect from OProfile agent: "
71                   << err_str << "\n");
72    } else {
73      DEBUG(dbgs() << "Disconnected from OProfile agent.\n");
74    }
75  }
76}
77
78static debug_line_info LineStartToOProfileFormat(
79    const MachineFunction &MF, FilenameCache &Filenames,
80    uintptr_t Address, DebugLoc Loc) {
81  debug_line_info Result;
82  Result.vma = Address;
83  Result.lineno = Loc.getLine();
84  Result.filename = Filenames.getFilename(
85    Loc.getScope(MF.getFunction()->getContext()));
86  DEBUG(dbgs() << "Mapping " << reinterpret_cast<void*>(Result.vma) << " to "
87               << Result.filename << ":" << Result.lineno << "\n");
88  return Result;
89}
90
91// Adds the just-emitted function to the symbol table.
92void OProfileJITEventListener::NotifyFunctionEmitted(
93    const Function &F, void *FnStart, size_t FnSize,
94    const JITEvent_EmittedFunctionDetails &Details) {
95  assert(F.hasName() && FnStart != 0 && "Bad symbol to add");
96  if (Wrapper.op_write_native_code(F.getName().data(),
97                           reinterpret_cast<uint64_t>(FnStart),
98                           FnStart, FnSize) == -1) {
99    DEBUG(dbgs() << "Failed to tell OProfile about native function "
100          << F.getName() << " at ["
101          << FnStart << "-" << ((char*)FnStart + FnSize) << "]\n");
102    return;
103  }
104
105  if (!Details.LineStarts.empty()) {
106    // Now we convert the line number information from the address/DebugLoc
107    // format in Details to the address/filename/lineno format that OProfile
108    // expects.  Note that OProfile 0.9.4 has a bug that causes it to ignore
109    // line numbers for addresses above 4G.
110    FilenameCache Filenames;
111    std::vector<debug_line_info> LineInfo;
112    LineInfo.reserve(1 + Details.LineStarts.size());
113
114    DebugLoc FirstLoc = Details.LineStarts[0].Loc;
115    assert(!FirstLoc.isUnknown()
116           && "LineStarts should not contain unknown DebugLocs");
117    MDNode *FirstLocScope = FirstLoc.getScope(F.getContext());
118    DISubprogram FunctionDI = getDISubprogram(FirstLocScope);
119    if (FunctionDI.Verify()) {
120      // If we have debug info for the function itself, use that as the line
121      // number of the first several instructions.  Otherwise, after filling
122      // LineInfo, we'll adjust the address of the first line number to point at
123      // the start of the function.
124      debug_line_info line_info;
125      line_info.vma = reinterpret_cast<uintptr_t>(FnStart);
126      line_info.lineno = FunctionDI.getLineNumber();
127      line_info.filename = Filenames.getFilename(FirstLocScope);
128      LineInfo.push_back(line_info);
129    }
130
131    for (std::vector<EmittedFunctionDetails::LineStart>::const_iterator
132           I = Details.LineStarts.begin(), E = Details.LineStarts.end();
133         I != E; ++I) {
134      LineInfo.push_back(LineStartToOProfileFormat(
135                           *Details.MF, Filenames, I->Address, I->Loc));
136    }
137
138    // In case the function didn't have line info of its own, adjust the first
139    // line info's address to include the start of the function.
140    LineInfo[0].vma = reinterpret_cast<uintptr_t>(FnStart);
141
142    if (Wrapper.op_write_debug_line_info(FnStart, LineInfo.size(),
143                                      &*LineInfo.begin()) == -1) {
144      DEBUG(dbgs()
145            << "Failed to tell OProfile about line numbers for native function "
146            << F.getName() << " at ["
147            << FnStart << "-" << ((char*)FnStart + FnSize) << "]\n");
148    }
149  }
150}
151
152// Removes the being-deleted function from the symbol table.
153void OProfileJITEventListener::NotifyFreeingMachineCode(void *FnStart) {
154  assert(FnStart && "Invalid function pointer");
155  if (Wrapper.op_unload_native_code(reinterpret_cast<uint64_t>(FnStart)) == -1) {
156    DEBUG(dbgs()
157          << "Failed to tell OProfile about unload of native function at "
158          << FnStart << "\n");
159  }
160}
161
162}  // anonymous namespace.
163
164namespace llvm {
165JITEventListener *JITEventListener::createOProfileJITEventListener() {
166  static OwningPtr<OProfileWrapper> JITProfilingWrapper(new OProfileWrapper);
167  return new OProfileJITEventListener(*JITProfilingWrapper);
168}
169
170// for testing
171JITEventListener *JITEventListener::createOProfileJITEventListener(
172                                      OProfileWrapper* TestImpl) {
173  return new OProfileJITEventListener(*TestImpl);
174}
175
176} // namespace llvm
177
178