//===- GCOVr.cpp - LLVM coverage tool -------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// GCOV implements the interface to read and write coverage files that use
// 'gcov' format.
//
//===----------------------------------------------------------------------===//

#include "llvm/Support/Debug.h"
#include "llvm/Support/GCOV.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/MemoryObject.h"
#include "llvm/Support/system_error.h"
using namespace llvm;

//===----------------------------------------------------------------------===//
// GCOVFile implementation.

/// ~GCOVFile - Delete GCOVFile and its content.
GCOVFile::~GCOVFile() {
  DeleteContainerPointers(Functions);
}

/// readGCNO - Read GCNO buffer.
bool GCOVFile::readGCNO(GCOVBuffer &Buffer) {
  if (!Buffer.readGCNOFormat()) return false;
  if (!Buffer.readGCOVVersion(Version)) return false;

  if (!Buffer.readInt(Checksum)) return false;
  while (true) {
    if (!Buffer.readFunctionTag()) break;
    GCOVFunction *GFun = new GCOVFunction();
    if (!GFun->readGCNO(Buffer, Version))
      return false;
    Functions.push_back(GFun);
  }

  gcnoInitialized = true;
  return true;
}

/// readGCDA - Read GCDA buffer. It is required that readGCDA() can only be
/// called after readGCNO().
bool GCOVFile::readGCDA(GCOVBuffer &Buffer) {
  assert(gcnoInitialized && "readGCDA() can only be called after readGCNO()");
  if (!Buffer.readGCDAFormat()) return false;
  GCOV::GCOVVersion GCDAVersion;
  if (!Buffer.readGCOVVersion(GCDAVersion)) return false;
  if (Version != GCDAVersion) {
    errs() << "GCOV versions do not match.\n";
    return false;
  }

  uint32_t GCDAChecksum;
  if (!Buffer.readInt(GCDAChecksum)) return false;
  if (Checksum != GCDAChecksum) {
    errs() << "File checksum does not match.\n";
    return false;
  }
  for (size_t i = 0, e = Functions.size(); i < e; ++i) {
    if (!Buffer.readFunctionTag()) {
      errs() << "Unexpected number of functions.\n";
      return false;
    }
    if (!Functions[i]->readGCDA(Buffer, Version))
      return false;
  }
  if (Buffer.readObjectTag()) {
    uint32_t Length;
    uint32_t Dummy;
    if (!Buffer.readInt(Length)) return false;
    if (!Buffer.readInt(Dummy)) return false; // checksum
    if (!Buffer.readInt(Dummy)) return false; // num
    if (!Buffer.readInt(RunCount)) return false;;
    Buffer.advanceCursor(Length-3);
  }
  while (Buffer.readProgramTag()) {
    uint32_t Length;
    if (!Buffer.readInt(Length)) return false;
    Buffer.advanceCursor(Length);
    ++ProgramCount;
  }

  return true;
}

/// dump - Dump GCOVFile content to dbgs() for debugging purposes.
void GCOVFile::dump() const {
  for (SmallVectorImpl<GCOVFunction *>::const_iterator I = Functions.begin(),
         E = Functions.end(); I != E; ++I)
    (*I)->dump();
}

/// collectLineCounts - Collect line counts. This must be used after
/// reading .gcno and .gcda files.
void GCOVFile::collectLineCounts(FileInfo &FI) {
  for (SmallVectorImpl<GCOVFunction *>::iterator I = Functions.begin(),
         E = Functions.end(); I != E; ++I)
    (*I)->collectLineCounts(FI);
  FI.setRunCount(RunCount);
  FI.setProgramCount(ProgramCount);
}

//===----------------------------------------------------------------------===//
// GCOVFunction implementation.

/// ~GCOVFunction - Delete GCOVFunction and its content.
GCOVFunction::~GCOVFunction() {
  DeleteContainerPointers(Blocks);
  DeleteContainerPointers(Edges);
}

/// readGCNO - Read a function from the GCNO buffer. Return false if an error
/// occurs.
bool GCOVFunction::readGCNO(GCOVBuffer &Buff, GCOV::GCOVVersion Version) {
  uint32_t Dummy;
  if (!Buff.readInt(Dummy)) return false; // Function header length
  if (!Buff.readInt(Ident)) return false;
  if (!Buff.readInt(Dummy)) return false; // Checksum #1
  if (Version != GCOV::V402)
    if (!Buff.readInt(Dummy)) return false; // Checksum #2

  if (!Buff.readString(Name)) return false;
  if (!Buff.readString(Filename)) return false;
  if (!Buff.readInt(LineNumber)) return false;

  // read blocks.
  if (!Buff.readBlockTag()) {
    errs() << "Block tag not found.\n";
    return false;
  }
  uint32_t BlockCount;
  if (!Buff.readInt(BlockCount)) return false;
  for (uint32_t i = 0, e = BlockCount; i != e; ++i) {
    if (!Buff.readInt(Dummy)) return false; // Block flags;
    Blocks.push_back(new GCOVBlock(*this, i));
  }

  // read edges.
  while (Buff.readEdgeTag()) {
    uint32_t EdgeCount;
    if (!Buff.readInt(EdgeCount)) return false;
    EdgeCount = (EdgeCount - 1) / 2;
    uint32_t BlockNo;
    if (!Buff.readInt(BlockNo)) return false;
    if (BlockNo >= BlockCount) {
      errs() << "Unexpected block number.\n";
      return false;
    }
    for (uint32_t i = 0, e = EdgeCount; i != e; ++i) {
      uint32_t Dst;
      if (!Buff.readInt(Dst)) return false;
      GCOVEdge *Edge = new GCOVEdge(Blocks[BlockNo], Blocks[Dst]);
      Edges.push_back(Edge);
      Blocks[BlockNo]->addDstEdge(Edge);
      Blocks[Dst]->addSrcEdge(Edge);
      if (!Buff.readInt(Dummy)) return false; // Edge flag
    }
  }

  // read line table.
  while (Buff.readLineTag()) {
    uint32_t LineTableLength;
    if (!Buff.readInt(LineTableLength)) return false;
    uint32_t EndPos = Buff.getCursor() + LineTableLength*4;
    uint32_t BlockNo;
    if (!Buff.readInt(BlockNo)) return false;
    if (BlockNo >= BlockCount) {
      errs() << "Unexpected block number.\n";
      return false;
    }
    GCOVBlock *Block = Blocks[BlockNo];
    if (!Buff.readInt(Dummy)) return false; // flag
    while (Buff.getCursor() != (EndPos - 4)) {
      StringRef F;
      if (!Buff.readString(F)) return false;
      if (F != Filename) {
        errs() << "Multiple sources for a single basic block.\n";
        return false;
      }
      if (Buff.getCursor() == (EndPos - 4)) break;
      while (true) {
        uint32_t Line;
        if (!Buff.readInt(Line)) return false;
        if (!Line) break;
        Block->addLine(Line);
      }
    }
    if (!Buff.readInt(Dummy)) return false; // flag
  }
  return true;
}

/// readGCDA - Read a function from the GCDA buffer. Return false if an error
/// occurs.
bool GCOVFunction::readGCDA(GCOVBuffer &Buff, GCOV::GCOVVersion Version) {
  uint32_t Dummy;
  if (!Buff.readInt(Dummy)) return false; // Function header length
  if (!Buff.readInt(Ident)) return false;
  if (!Buff.readInt(Dummy)) return false; // Checksum #1
  if (Version != GCOV::V402)
    if (!Buff.readInt(Dummy)) return false; // Checksum #2

  if (!Buff.readString(Name)) return false;

  if (!Buff.readArcTag()) {
    errs() << "Arc tag not found.\n";
    return false;
  }

  uint32_t Count;
  if (!Buff.readInt(Count)) return false;
  Count /= 2;

  // This for loop adds the counts for each block. A second nested loop is
  // required to combine the edge counts that are contained in the GCDA file.
  for (uint32_t BlockNo = 0; Count > 0; ++BlockNo) {
    // The last block is always reserved for exit block
    if (BlockNo >= Blocks.size()-1) {
      errs() << "Unexpected number of edges.\n";
      return false;
    }
    GCOVBlock &Block = *Blocks[BlockNo];
    for (size_t EdgeNo = 0, End = Block.getNumDstEdges(); EdgeNo < End;
           ++EdgeNo) {
      if (Count == 0) {
        errs() << "Unexpected number of edges.\n";
        return false;
      }
      uint64_t ArcCount;
      if (!Buff.readInt64(ArcCount)) return false;
      Block.addCount(EdgeNo, ArcCount);
      --Count;
    }
  }
  return true;
}

/// dump - Dump GCOVFunction content to dbgs() for debugging purposes.
void GCOVFunction::dump() const {
  dbgs() <<  "===== " << Name << " @ " << Filename << ":" << LineNumber << "\n";
  for (SmallVectorImpl<GCOVBlock *>::const_iterator I = Blocks.begin(),
         E = Blocks.end(); I != E; ++I)
    (*I)->dump();
}

/// collectLineCounts - Collect line counts. This must be used after
/// reading .gcno and .gcda files.
void GCOVFunction::collectLineCounts(FileInfo &FI) {
  for (SmallVectorImpl<GCOVBlock *>::iterator I = Blocks.begin(),
         E = Blocks.end(); I != E; ++I)
    (*I)->collectLineCounts(FI);
}

//===----------------------------------------------------------------------===//
// GCOVBlock implementation.

/// ~GCOVBlock - Delete GCOVBlock and its content.
GCOVBlock::~GCOVBlock() {
  SrcEdges.clear();
  DstEdges.clear();
  Lines.clear();
}

/// addCount - Add to block counter while storing the edge count. If the
/// destination has no outgoing edges, also update that block's count too.
void GCOVBlock::addCount(size_t DstEdgeNo, uint64_t N) {
  assert(DstEdgeNo < DstEdges.size()); // up to caller to ensure EdgeNo is valid
  DstEdges[DstEdgeNo]->Count = N;
  Counter += N;
  if (!DstEdges[DstEdgeNo]->Dst->getNumDstEdges())
    DstEdges[DstEdgeNo]->Dst->Counter += N;
}

/// collectLineCounts - Collect line counts. This must be used after
/// reading .gcno and .gcda files.
void GCOVBlock::collectLineCounts(FileInfo &FI) {
  for (SmallVectorImpl<uint32_t>::iterator I = Lines.begin(),
         E = Lines.end(); I != E; ++I)
    FI.addBlockLine(Parent.getFilename(), *I, this);
}

/// dump - Dump GCOVBlock content to dbgs() for debugging purposes.
void GCOVBlock::dump() const {
  dbgs() << "Block : " << Number << " Counter : " << Counter << "\n";
  if (!SrcEdges.empty()) {
    dbgs() << "\tSource Edges : ";
    for (EdgeIterator I = SrcEdges.begin(), E = SrcEdges.end(); I != E; ++I) {
      const GCOVEdge *Edge = *I;
      dbgs() << Edge->Src->Number << " (" << Edge->Count << "), ";
    }
    dbgs() << "\n";
  }
  if (!DstEdges.empty()) {
    dbgs() << "\tDestination Edges : ";
    for (EdgeIterator I = DstEdges.begin(), E = DstEdges.end(); I != E; ++I) {
      const GCOVEdge *Edge = *I;
      dbgs() << Edge->Dst->Number << " (" << Edge->Count << "), ";
    }
    dbgs() << "\n";
  }
  if (!Lines.empty()) {
    dbgs() << "\tLines : ";
    for (SmallVectorImpl<uint32_t>::const_iterator I = Lines.begin(),
           E = Lines.end(); I != E; ++I)
      dbgs() << (*I) << ",";
    dbgs() << "\n";
  }
}

//===----------------------------------------------------------------------===//
// FileInfo implementation.

/// print -  Print source files with collected line count information.
void FileInfo::print(StringRef gcnoFile, StringRef gcdaFile) const {
  for (StringMap<LineData>::const_iterator I = LineInfo.begin(),
         E = LineInfo.end(); I != E; ++I) {
    StringRef Filename = I->first();
    OwningPtr<MemoryBuffer> Buff;
    if (error_code ec = MemoryBuffer::getFileOrSTDIN(Filename, Buff)) {
      errs() << Filename << ": " << ec.message() << "\n";
      return;
    }
    StringRef AllLines = Buff->getBuffer();

    std::string CovFilename = Filename.str() + ".llcov";
    std::string ErrorInfo;
    raw_fd_ostream OS(CovFilename.c_str(), ErrorInfo);
    if (!ErrorInfo.empty())
      errs() << ErrorInfo << "\n";

    OS << "        -:    0:Source:" << Filename << "\n";
    OS << "        -:    0:Graph:" << gcnoFile << "\n";
    OS << "        -:    0:Data:" << gcdaFile << "\n";
    OS << "        -:    0:Runs:" << RunCount << "\n";
    OS << "        -:    0:Programs:" << ProgramCount << "\n";

    const LineData &Line = I->second;
    for (uint32_t i = 0; !AllLines.empty(); ++i) {
      LineData::const_iterator BlocksIt = Line.find(i);

      // Add up the block counts to form line counts.
      if (BlocksIt != Line.end()) {
        const BlockVector &Blocks = BlocksIt->second;
        uint64_t LineCount = 0;
        for (BlockVector::const_iterator I = Blocks.begin(), E = Blocks.end();
               I != E; ++I) {
          LineCount += (*I)->getCount();
        }
        if (LineCount == 0)
          OS << "    #####:";
        else
          OS << format("%9" PRIu64 ":", LineCount);
      } else {
        OS << "        -:";
      }
      std::pair<StringRef, StringRef> P = AllLines.split('\n');
      OS << format("%5u:", i+1) << P.first << "\n";
      AllLines = P.second;
    }
  }
}