//===-- IntelJITEventListener.cpp - Tell Intel profiler about JITed code --===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines a JITEventListener object to tell Intel(R) VTune(TM)
// Amplifier XE 2011 about JITted functions.
//
//===----------------------------------------------------------------------===//

#include "llvm/Config/config.h"
#include "IntelJITEventsWrapper.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/DebugInfo/DWARF/DIContext.h"
#include "llvm/ExecutionEngine/JITEventListener.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/ValueHandle.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Errno.h"
#include "llvm/Support/raw_ostream.h"

using namespace llvm;
using namespace llvm::object;

#define DEBUG_TYPE "amplifier-jit-event-listener"

namespace {

class IntelJITEventListener : public JITEventListener {
  typedef DenseMap<void*, unsigned int> MethodIDMap;

  std::unique_ptr<IntelJITEventsWrapper> Wrapper;
  MethodIDMap MethodIDs;

  typedef SmallVector<const void *, 64> MethodAddressVector;
  typedef DenseMap<const void *, MethodAddressVector>  ObjectMap;

  ObjectMap  LoadedObjectMap;
  std::map<const char*, OwningBinary<ObjectFile>> DebugObjects;

public:
  IntelJITEventListener(IntelJITEventsWrapper* libraryWrapper) {
      Wrapper.reset(libraryWrapper);
  }

  ~IntelJITEventListener() {
  }

  void NotifyObjectEmitted(const ObjectFile &Obj,
                           const RuntimeDyld::LoadedObjectInfo &L) override;

  void NotifyFreeingObject(const ObjectFile &Obj) override;
};

static LineNumberInfo DILineInfoToIntelJITFormat(uintptr_t StartAddress,
                                                 uintptr_t Address,
                                                 DILineInfo Line) {
  LineNumberInfo Result;

  Result.Offset = Address - StartAddress;
  Result.LineNumber = Line.Line;

  return Result;
}

static iJIT_Method_Load FunctionDescToIntelJITFormat(
    IntelJITEventsWrapper& Wrapper,
    const char* FnName,
    uintptr_t FnStart,
    size_t FnSize) {
  iJIT_Method_Load Result;
  memset(&Result, 0, sizeof(iJIT_Method_Load));

  Result.method_id = Wrapper.iJIT_GetNewMethodID();
  Result.method_name = const_cast<char*>(FnName);
  Result.method_load_address = reinterpret_cast<void*>(FnStart);
  Result.method_size = FnSize;

  Result.class_id = 0;
  Result.class_file_name = NULL;
  Result.user_data = NULL;
  Result.user_data_size = 0;
  Result.env = iJDE_JittingAPI;

  return Result;
}

void IntelJITEventListener::NotifyObjectEmitted(
                                       const ObjectFile &Obj,
                                       const RuntimeDyld::LoadedObjectInfo &L) {

  OwningBinary<ObjectFile> DebugObjOwner = L.getObjectForDebug(Obj);
  const ObjectFile &DebugObj = *DebugObjOwner.getBinary();

  // Get the address of the object image for use as a unique identifier
  const void* ObjData = DebugObj.getData().data();
  DIContext* Context = DIContext::getDWARFContext(DebugObj);
  MethodAddressVector Functions;

  // Use symbol info to iterate functions in the object.
  for (symbol_iterator I = DebugObj.symbol_begin(),
                       E = DebugObj.symbol_end();
                        I != E;
                        ++I) {
    std::vector<LineNumberInfo> LineInfo;
    std::string SourceFileName;

    SymbolRef::Type SymType;
    if (I->getType(SymType)) continue;
    if (SymType == SymbolRef::ST_Function) {
      StringRef  Name;
      uint64_t   Addr;
      uint64_t   Size;
      if (I->getName(Name)) continue;
      if (I->getAddress(Addr)) continue;
      if (I->getSize(Size)) continue;

      // Record this address in a local vector
      Functions.push_back((void*)Addr);

      // Build the function loaded notification message
      iJIT_Method_Load FunctionMessage = FunctionDescToIntelJITFormat(*Wrapper,
                                           Name.data(),
                                           Addr,
                                           Size);
      if (Context) {
        DILineInfoTable  Lines = Context->getLineInfoForAddressRange(Addr, Size);
        DILineInfoTable::iterator  Begin = Lines.begin();
        DILineInfoTable::iterator  End = Lines.end();
        for (DILineInfoTable::iterator It = Begin; It != End; ++It) {
          LineInfo.push_back(DILineInfoToIntelJITFormat((uintptr_t)Addr,
                                                        It->first,
                                                        It->second));
        }
        if (LineInfo.size() == 0) {
          FunctionMessage.source_file_name = 0;
          FunctionMessage.line_number_size = 0;
          FunctionMessage.line_number_table = 0;
        } else {
          // Source line information for the address range is provided as 
          // a code offset for the start of the corresponding sub-range and
          // a source line. JIT API treats offsets in LineNumberInfo structures
          // as the end of the corresponding code region. The start of the code
          // is taken from the previous element. Need to shift the elements.

          LineNumberInfo last = LineInfo.back();
          last.Offset = FunctionMessage.method_size;
          LineInfo.push_back(last);
          for (size_t i = LineInfo.size() - 2; i > 0; --i)
            LineInfo[i].LineNumber = LineInfo[i - 1].LineNumber;

          SourceFileName = Lines.front().second.FileName;
          FunctionMessage.source_file_name = const_cast<char *>(SourceFileName.c_str());
          FunctionMessage.line_number_size = LineInfo.size();
          FunctionMessage.line_number_table = &*LineInfo.begin();
        }
      } else {
        FunctionMessage.source_file_name = 0;
        FunctionMessage.line_number_size = 0;
        FunctionMessage.line_number_table = 0;
      }

      Wrapper->iJIT_NotifyEvent(iJVM_EVENT_TYPE_METHOD_LOAD_FINISHED,
                                &FunctionMessage);
      MethodIDs[(void*)Addr] = FunctionMessage.method_id;
    }
  }

  // To support object unload notification, we need to keep a list of
  // registered function addresses for each loaded object.  We will
  // use the MethodIDs map to get the registered ID for each function.
  LoadedObjectMap[ObjData] = Functions;
  DebugObjects[Obj.getData().data()] = std::move(DebugObjOwner);
}

void IntelJITEventListener::NotifyFreeingObject(const ObjectFile &Obj) {
  // This object may not have been registered with the listener. If it wasn't,
  // bail out.
  if (DebugObjects.find(Obj.getData().data()) == DebugObjects.end())
    return;

  // Get the address of the object image for use as a unique identifier
  const ObjectFile &DebugObj = *DebugObjects[Obj.getData().data()].getBinary();
  const void* ObjData = DebugObj.getData().data();

  // Get the object's function list from LoadedObjectMap
  ObjectMap::iterator OI = LoadedObjectMap.find(ObjData);
  if (OI == LoadedObjectMap.end())
    return;
  MethodAddressVector& Functions = OI->second;

  // Walk the function list, unregistering each function
  for (MethodAddressVector::iterator FI = Functions.begin(),
                                     FE = Functions.end();
       FI != FE;
       ++FI) {
    void* FnStart = const_cast<void*>(*FI);
    MethodIDMap::iterator MI = MethodIDs.find(FnStart);
    if (MI != MethodIDs.end()) {
      Wrapper->iJIT_NotifyEvent(iJVM_EVENT_TYPE_METHOD_UNLOAD_START,
                                &MI->second);
      MethodIDs.erase(MI);
    }
  }

  // Erase the object from LoadedObjectMap
  LoadedObjectMap.erase(OI);
  DebugObjects.erase(Obj.getData().data());
}

}  // anonymous namespace.

namespace llvm {
JITEventListener *JITEventListener::createIntelJITEventListener() {
  return new IntelJITEventListener(new IntelJITEventsWrapper);
}

// for testing
JITEventListener *JITEventListener::createIntelJITEventListener(
                                      IntelJITEventsWrapper* TestImpl) {
  return new IntelJITEventListener(TestImpl);
}

} // namespace llvm