X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FIR%2FGCOV.cpp;h=6ed589131725e82700fbe97f01a60ed96ed33ab6;hb=416a5187f7804f37183b46d8f7bf43fa89a9b5a3;hp=65ed3a5a84bf47da5820dfd22a4bdb86454cec26;hpb=131a764e0e7abc90b322fd568e042d3c5a0633af;p=oota-llvm.git

diff --git a/lib/IR/GCOV.cpp b/lib/IR/GCOV.cpp
index 65ed3a5a84b..6ed58913172 100644
--- a/lib/IR/GCOV.cpp
+++ b/lib/IR/GCOV.cpp
@@ -1,4 +1,4 @@
-//===- GCOVr.cpp - LLVM coverage tool -------------------------------------===//
+//===- GCOV.cpp - LLVM coverage tool --------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -7,95 +7,113 @@
 //
 //===----------------------------------------------------------------------===//
 //
-// GCOV implements the interface to read and write coverage files that use 
+// 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/Debug.h"
+#include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/MemoryObject.h"
-#include "llvm/Support/system_error.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+#include <system_error>
 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;
 
-/// isGCDAFile - Return true if Format identifies a .gcda file.
-static bool isGCDAFile(GCOV::GCOVFormat Format) {
-  return Format == GCOV::GCDA_402 || Format == GCOV::GCDA_404;
-}
+  if (!Buffer.readInt(Checksum))
+    return false;
+  while (true) {
+    if (!Buffer.readFunctionTag())
+      break;
+    auto GFun = make_unique<GCOVFunction>(*this);
+    if (!GFun->readGCNO(Buffer, Version))
+      return false;
+    Functions.push_back(std::move(GFun));
+  }
 
-/// isGCNOFile - Return true if Format identifies a .gcno file.
-static bool isGCNOFile(GCOV::GCOVFormat Format) {
-  return Format == GCOV::GCNO_402 || Format == GCOV::GCNO_404;
+  GCNOInitialized = true;
+  return true;
 }
 
-/// read - Read GCOV buffer.
-bool GCOVFile::read(GCOVBuffer &Buffer) {
-  GCOV::GCOVFormat Format = Buffer.readGCOVFormat();
-  if (Format == GCOV::InvalidGCOV)
+/// 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;
+  }
 
-  if (isGCNOFile(Format)) {
-    while (true) {
-      if (!Buffer.readFunctionTag()) break;
-      GCOVFunction *GFun = new GCOVFunction();
-      if (!GFun->read(Buffer, Format))
-        return false;
-      Functions.push_back(GFun);
-    }
+  uint32_t GCDAChecksum;
+  if (!Buffer.readInt(GCDAChecksum))
+    return false;
+  if (Checksum != GCDAChecksum) {
+    errs() << "File checksums do not match: " << Checksum
+           << " != " << GCDAChecksum << ".\n";
+    return false;
   }
-  else if (isGCDAFile(Format)) {
-    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]->read(Buffer, Format))
-        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;
+  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() {
-  for (SmallVectorImpl<GCOVFunction *>::iterator I = Functions.begin(),
-         E = Functions.end(); I != E; ++I)
-    (*I)->dump();
+void GCOVFile::dump() const {
+  for (const auto &FPtr : Functions)
+    FPtr->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);
+  for (const auto &FPtr : Functions)
+    FPtr->collectLineCounts(FI);
   FI.setRunCount(RunCount);
   FI.setProgramCount(ProgramCount);
 }
@@ -103,54 +121,32 @@ void GCOVFile::collectLineCounts(FileInfo &FI) {
 //===----------------------------------------------------------------------===//
 // GCOVFunction implementation.
 
-/// ~GCOVFunction - Delete GCOVFunction and its content.
-GCOVFunction::~GCOVFunction() {
-  DeleteContainerPointers(Blocks);
-}
-
-/// read - Read a function from the buffer. Return false if buffer cursor
-/// does not point to a function tag.
-bool GCOVFunction::read(GCOVBuffer &Buff, GCOV::GCOVFormat Format) {
+/// 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 (Format != GCOV::GCNO_402 && Format != GCOV::GCDA_402)
-    if (!Buff.readInt(Dummy)) return false; // Checksum #2
-
-  if (!Buff.readString(Name)) return false;
-
-  if (Format == GCOV::GCNO_402 || Format == GCOV::GCNO_404)
-    if (!Buff.readString(Filename)) return false;
-
-  if (Format == GCOV::GCDA_402 || Format == GCOV::GCDA_404) {
-    if (!Buff.readArcTag()) {
-      errs() << "Arc tag not found.\n";
+  if (!Buff.readInt(Dummy))
+    return false; // Function header length
+  if (!Buff.readInt(Ident))
+    return false;
+  if (!Buff.readInt(Checksum))
+    return false;
+  if (Version != GCOV::V402) {
+    uint32_t CfgChecksum;
+    if (!Buff.readInt(CfgChecksum))
+      return false;
+    if (Parent.getChecksum() != CfgChecksum) {
+      errs() << "File checksums do not match: " << Parent.getChecksum()
+             << " != " << CfgChecksum << " in (" << Name << ").\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 Line = 0; Count > 0; ++Line) {
-      GCOVBlock &Block = *Blocks[Line];
-      for (size_t Edge = 0, End = Block.getNumEdges(); Edge < End; ++Edge) {
-        if (Count == 0) {
-          errs() << "Unexpected number of edges.\n";
-          return false;
-        }
-        uint64_t ArcCount;
-        if (!Buff.readInt64(ArcCount)) return false;
-        Block.addCount(ArcCount);
-        --Count;
-      }
-    }
-    return true;
   }
-
-  if (!Buff.readInt(LineNumber)) return false;
+  if (!Buff.readString(Name))
+    return false;
+  if (!Buff.readString(Filename))
+    return false;
+  if (!Buff.readInt(LineNumber))
+    return false;
 
   // read blocks.
   if (!Buff.readBlockTag()) {
@@ -158,78 +154,210 @@ bool GCOVFunction::read(GCOVBuffer &Buff, GCOV::GCOVFormat Format) {
     return false;
   }
   uint32_t BlockCount;
-  if (!Buff.readInt(BlockCount)) return false;
+  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));
+    if (!Buff.readInt(Dummy))
+      return false; // Block flags;
+    Blocks.push_back(make_unique<GCOVBlock>(*this, i));
   }
 
   // read edges.
   while (Buff.readEdgeTag()) {
     uint32_t EdgeCount;
-    if (!Buff.readInt(EdgeCount)) return false;
+    if (!Buff.readInt(EdgeCount))
+      return false;
     EdgeCount = (EdgeCount - 1) / 2;
     uint32_t BlockNo;
-    if (!Buff.readInt(BlockNo)) return false;
+    if (!Buff.readInt(BlockNo))
+      return false;
     if (BlockNo >= BlockCount) {
-      errs() << "Unexpected block number.\n";
+      errs() << "Unexpected block number: " << BlockNo << " (in " << Name
+             << ").\n";
       return false;
     }
     for (uint32_t i = 0, e = EdgeCount; i != e; ++i) {
       uint32_t Dst;
-      if (!Buff.readInt(Dst)) return false;
-      Blocks[BlockNo]->addEdge(Dst);
-      if (!Buff.readInt(Dummy)) return false; // Edge flag
+      if (!Buff.readInt(Dst))
+        return false;
+      Edges.push_back(make_unique<GCOVEdge>(*Blocks[BlockNo], *Blocks[Dst]));
+      GCOVEdge *Edge = Edges.back().get();
+      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;
+    // Read the length of this line table.
+    if (!Buff.readInt(LineTableLength))
+      return false;
+    uint32_t EndPos = Buff.getCursor() + LineTableLength * 4;
     uint32_t BlockNo;
-    if (!Buff.readInt(BlockNo)) return false;
+    // Read the block number this table is associated with.
+    if (!Buff.readInt(BlockNo))
+      return false;
     if (BlockNo >= BlockCount) {
-      errs() << "Unexpected block number.\n";
+      errs() << "Unexpected block number: " << BlockNo << " (in " << Name
+             << ").\n";
       return false;
     }
-    GCOVBlock *Block = Blocks[BlockNo];
-    if (!Buff.readInt(Dummy)) return false; // flag
-    while (Buff.getCursor() != (EndPos - 4)) {
+    GCOVBlock &Block = *Blocks[BlockNo];
+    // Read the word that pads the beginning of the line table. This may be a
+    // flag of some sort, but seems to always be zero.
+    if (!Buff.readInt(Dummy))
+      return false;
+
+    // Line information starts here and continues up until the last word.
+    if (Buff.getCursor() != (EndPos - sizeof(uint32_t))) {
       StringRef F;
-      if (!Buff.readString(F)) return false;
-      if (F != Filename) {
-        errs() << "Multiple sources for a single basic block.\n";
+      // Read the source file name.
+      if (!Buff.readString(F))
+        return false;
+      if (Filename != F) {
+        errs() << "Multiple sources for a single basic block: " << Filename
+               << " != " << F << " (in " << Name << ").\n";
         return false;
       }
-      if (Buff.getCursor() == (EndPos - 4)) break;
-      while (true) {
+      // Read lines up to, but not including, the null terminator.
+      while (Buff.getCursor() < (EndPos - 2 * sizeof(uint32_t))) {
         uint32_t Line;
-        if (!Buff.readInt(Line)) return false;
-        if (!Line) break;
-        Block->addLine(Line);
+        if (!Buff.readInt(Line))
+          return false;
+        // Line 0 means this instruction was injected by the compiler. Skip it.
+        if (!Line)
+          continue;
+        Block.addLine(Line);
       }
+      // Read the null terminator.
+      if (!Buff.readInt(Dummy))
+        return false;
     }
-    if (!Buff.readInt(Dummy)) return false; // flag
+    // The last word is either a flag or padding, it isn't clear which. Skip
+    // over it.
+    if (!Buff.readInt(Dummy))
+      return false;
   }
   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
+
+  uint32_t GCDAIdent;
+  if (!Buff.readInt(GCDAIdent))
+    return false;
+  if (Ident != GCDAIdent) {
+    errs() << "Function identifiers do not match: " << Ident
+           << " != " << GCDAIdent << " (in " << Name << ").\n";
+    return false;
+  }
+
+  uint32_t GCDAChecksum;
+  if (!Buff.readInt(GCDAChecksum))
+    return false;
+  if (Checksum != GCDAChecksum) {
+    errs() << "Function checksums do not match: " << Checksum
+           << " != " << GCDAChecksum << " (in " << Name << ").\n";
+    return false;
+  }
+
+  uint32_t CfgChecksum;
+  if (Version != GCOV::V402) {
+    if (!Buff.readInt(CfgChecksum))
+      return false;
+    if (Parent.getChecksum() != CfgChecksum) {
+      errs() << "File checksums do not match: " << Parent.getChecksum()
+             << " != " << CfgChecksum << " (in " << Name << ").\n";
+      return false;
+    }
+  }
+
+  StringRef GCDAName;
+  if (!Buff.readString(GCDAName))
+    return false;
+  if (Name != GCDAName) {
+    errs() << "Function names do not match: " << Name << " != " << GCDAName
+           << ".\n";
+    return false;
+  }
+
+  if (!Buff.readArcTag()) {
+    errs() << "Arc tag not found (in " << Name << ").\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()) {
+      errs() << "Unexpected number of edges (in " << Name << ").\n";
+      return false;
+    }
+    if (BlockNo == Blocks.size() - 1)
+      errs() << "(" << Name << ") has arcs from exit block.\n";
+    GCOVBlock &Block = *Blocks[BlockNo];
+    for (size_t EdgeNo = 0, End = Block.getNumDstEdges(); EdgeNo < End;
+         ++EdgeNo) {
+      if (Count == 0) {
+        errs() << "Unexpected number of edges (in " << Name << ").\n";
+        return false;
+      }
+      uint64_t ArcCount;
+      if (!Buff.readInt64(ArcCount))
+        return false;
+      Block.addCount(EdgeNo, ArcCount);
+      --Count;
+    }
+    Block.sortDstEdges();
+  }
+  return true;
+}
+
+/// getEntryCount - Get the number of times the function was called by
+/// retrieving the entry block's count.
+uint64_t GCOVFunction::getEntryCount() const {
+  return Blocks.front()->getCount();
+}
+
+/// getExitCount - Get the number of times the function returned by retrieving
+/// the exit block's count.
+uint64_t GCOVFunction::getExitCount() const {
+  return Blocks.back()->getCount();
+}
+
 /// dump - Dump GCOVFunction content to dbgs() for debugging purposes.
-void GCOVFunction::dump() {
-  dbgs() <<  "===== " << Name << " @ " << Filename << ":" << LineNumber << "\n";
-  for (SmallVectorImpl<GCOVBlock *>::iterator I = Blocks.begin(),
-         E = Blocks.end(); I != E; ++I)
-    (*I)->dump();
+void GCOVFunction::dump() const {
+  dbgs() << "===== " << Name << " (" << Ident << ") @ " << Filename << ":"
+         << LineNumber << "\n";
+  for (const auto &Block : Blocks)
+    Block->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);
+  // If the line number is zero, this is a function that doesn't actually appear
+  // in the source file, so there isn't anything we can do with it.
+  if (LineNumber == 0)
+    return;
+
+  for (const auto &Block : Blocks)
+    Block->collectLineCounts(FI);
+  FI.addFunctionLine(Filename, LineNumber, this);
 }
 
 //===----------------------------------------------------------------------===//
@@ -237,33 +365,56 @@ void GCOVFunction::collectLineCounts(FileInfo &FI) {
 
 /// ~GCOVBlock - Delete GCOVBlock and its content.
 GCOVBlock::~GCOVBlock() {
-  Edges.clear();
+  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;
+}
+
+/// sortDstEdges - Sort destination edges by block number, nop if already
+/// sorted. This is required for printing branch info in the correct order.
+void GCOVBlock::sortDstEdges() {
+  if (!DstEdgesAreSorted) {
+    SortDstEdgesFunctor SortEdges;
+    std::stable_sort(DstEdges.begin(), DstEdges.end(), SortEdges);
+  }
+}
+
 /// 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.addLineCount(Parent.getFilename(), *I, Counter);
+  for (uint32_t N : Lines)
+    FI.addBlockLine(Parent.getFilename(), N, this);
 }
 
 /// dump - Dump GCOVBlock content to dbgs() for debugging purposes.
-void GCOVBlock::dump() {
+void GCOVBlock::dump() const {
   dbgs() << "Block : " << Number << " Counter : " << Counter << "\n";
-  if (!Edges.empty()) {
-    dbgs() << "\tEdges : ";
-    for (SmallVectorImpl<uint32_t>::iterator I = Edges.begin(), E = Edges.end();
-         I != E; ++I)
-      dbgs() << (*I) << ",";
+  if (!SrcEdges.empty()) {
+    dbgs() << "\tSource Edges : ";
+    for (const GCOVEdge *Edge : SrcEdges)
+      dbgs() << Edge->Src.Number << " (" << Edge->Count << "), ";
+    dbgs() << "\n";
+  }
+  if (!DstEdges.empty()) {
+    dbgs() << "\tDestination Edges : ";
+    for (const GCOVEdge *Edge : DstEdges)
+      dbgs() << Edge->Dst.Number << " (" << Edge->Count << "), ";
     dbgs() << "\n";
   }
   if (!Lines.empty()) {
     dbgs() << "\tLines : ";
-    for (SmallVectorImpl<uint32_t>::iterator I = Lines.begin(),
-           E = Lines.end(); I != E; ++I)
-      dbgs() << (*I) << ",";
+    for (uint32_t N : Lines)
+      dbgs() << (N) << ",";
     dbgs() << "\n";
   }
 }
@@ -271,41 +422,375 @@ void GCOVBlock::dump() {
 //===----------------------------------------------------------------------===//
 // FileInfo implementation.
 
-/// print -  Print source files with collected line count information.
-void FileInfo::print(raw_fd_ostream &OS, StringRef gcnoFile,
-                     StringRef gcdaFile) {
-  for (StringMap<LineCounts>::iterator I = LineInfo.begin(), E = LineInfo.end();
-       I != E; ++I) {
-    StringRef Filename = I->first();
-    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";
-    LineCounts &L = LineInfo[Filename];
-    OwningPtr<MemoryBuffer> Buff;
-    if (error_code ec = MemoryBuffer::getFileOrSTDIN(Filename, Buff)) {
-      errs() << Filename << ": " << ec.message() << "\n";
-      return;
+// Safe integer division, returns 0 if numerator is 0.
+static uint32_t safeDiv(uint64_t Numerator, uint64_t Divisor) {
+  if (!Numerator)
+    return 0;
+  return Numerator / Divisor;
+}
+
+// This custom division function mimics gcov's branch ouputs:
+//   - Round to closest whole number
+//   - Only output 0% or 100% if it's exactly that value
+static uint32_t branchDiv(uint64_t Numerator, uint64_t Divisor) {
+  if (!Numerator)
+    return 0;
+  if (Numerator == Divisor)
+    return 100;
+
+  uint8_t Res = (Numerator * 100 + Divisor / 2) / Divisor;
+  if (Res == 0)
+    return 1;
+  if (Res == 100)
+    return 99;
+  return Res;
+}
+
+namespace {
+struct formatBranchInfo {
+  formatBranchInfo(const GCOVOptions &Options, uint64_t Count, uint64_t Total)
+      : Options(Options), Count(Count), Total(Total) {}
+
+  void print(raw_ostream &OS) const {
+    if (!Total)
+      OS << "never executed";
+    else if (Options.BranchCount)
+      OS << "taken " << Count;
+    else
+      OS << "taken " << branchDiv(Count, Total) << "%";
+  }
+
+  const GCOVOptions &Options;
+  uint64_t Count;
+  uint64_t Total;
+};
+
+static raw_ostream &operator<<(raw_ostream &OS, const formatBranchInfo &FBI) {
+  FBI.print(OS);
+  return OS;
+}
+
+class LineConsumer {
+  std::unique_ptr<MemoryBuffer> Buffer;
+  StringRef Remaining;
+
+public:
+  LineConsumer(StringRef Filename) {
+    ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
+        MemoryBuffer::getFileOrSTDIN(Filename);
+    if (std::error_code EC = BufferOrErr.getError()) {
+      errs() << Filename << ": " << EC.message() << "\n";
+      Remaining = "";
+    } else {
+      Buffer = std::move(BufferOrErr.get());
+      Remaining = Buffer->getBuffer();
     }
-    StringRef AllLines = Buff.take()->getBuffer();
-    uint32_t i = 0;
-    while (!AllLines.empty()) {
-      if (L.find(i) != L.end()) {
-        if (L[i] == 0)
-          OS << "    #####:";
-        else
-          OS << format("%9lu:", L[i]);
+  }
+  bool empty() { return Remaining.empty(); }
+  void printNext(raw_ostream &OS, uint32_t LineNum) {
+    StringRef Line;
+    if (empty())
+      Line = "/*EOF*/";
+    else
+      std::tie(Line, Remaining) = Remaining.split("\n");
+    OS << format("%5u:", LineNum) << Line << "\n";
+  }
+};
+}
+
+/// Convert a path to a gcov filename. If PreservePaths is true, this
+/// translates "/" to "#", ".." to "^", and drops ".", to match gcov.
+static std::string mangleCoveragePath(StringRef Filename, bool PreservePaths) {
+  if (!PreservePaths)
+    return sys::path::filename(Filename).str();
+
+  // This behaviour is defined by gcov in terms of text replacements, so it's
+  // not likely to do anything useful on filesystems with different textual
+  // conventions.
+  llvm::SmallString<256> Result("");
+  StringRef::iterator I, S, E;
+  for (I = S = Filename.begin(), E = Filename.end(); I != E; ++I) {
+    if (*I != '/')
+      continue;
+
+    if (I - S == 1 && *S == '.') {
+      // ".", the current directory, is skipped.
+    } else if (I - S == 2 && *S == '.' && *(S + 1) == '.') {
+      // "..", the parent directory, is replaced with "^".
+      Result.append("^#");
+    } else {
+      if (S < I)
+        // Leave other components intact,
+        Result.append(S, I);
+      // And separate with "#".
+      Result.push_back('#');
+    }
+    S = I + 1;
+  }
+
+  if (S < I)
+    Result.append(S, I);
+  return Result.str();
+}
+
+std::string FileInfo::getCoveragePath(StringRef Filename,
+                                      StringRef MainFilename) {
+  if (Options.NoOutput)
+    // This is probably a bug in gcov, but when -n is specified, paths aren't
+    // mangled at all, and the -l and -p options are ignored. Here, we do the
+    // same.
+    return Filename;
+
+  std::string CoveragePath;
+  if (Options.LongFileNames && !Filename.equals(MainFilename))
+    CoveragePath =
+        mangleCoveragePath(MainFilename, Options.PreservePaths) + "##";
+  CoveragePath += mangleCoveragePath(Filename, Options.PreservePaths) + ".gcov";
+  return CoveragePath;
+}
+
+std::unique_ptr<raw_ostream>
+FileInfo::openCoveragePath(StringRef CoveragePath) {
+  if (Options.NoOutput)
+    return llvm::make_unique<raw_null_ostream>();
+
+  std::error_code EC;
+  auto OS = llvm::make_unique<raw_fd_ostream>(CoveragePath, EC,
+                                              sys::fs::F_Text);
+  if (EC) {
+    errs() << EC.message() << "\n";
+    return llvm::make_unique<raw_null_ostream>();
+  }
+  return std::move(OS);
+}
+
+/// print -  Print source files with collected line count information.
+void FileInfo::print(raw_ostream &InfoOS, StringRef MainFilename,
+                     StringRef GCNOFile, StringRef GCDAFile) {
+  for (const auto &LI : LineInfo) {
+    StringRef Filename = LI.first();
+    auto AllLines = LineConsumer(Filename);
+
+    std::string CoveragePath = getCoveragePath(Filename, MainFilename);
+    std::unique_ptr<raw_ostream> CovStream = openCoveragePath(CoveragePath);
+    raw_ostream &CovOS = *CovStream;
+
+    CovOS << "        -:    0:Source:" << Filename << "\n";
+    CovOS << "        -:    0:Graph:" << GCNOFile << "\n";
+    CovOS << "        -:    0:Data:" << GCDAFile << "\n";
+    CovOS << "        -:    0:Runs:" << RunCount << "\n";
+    CovOS << "        -:    0:Programs:" << ProgramCount << "\n";
+
+    const LineData &Line = LI.second;
+    GCOVCoverage FileCoverage(Filename);
+    for (uint32_t LineIndex = 0; LineIndex < Line.LastLine || !AllLines.empty();
+         ++LineIndex) {
+      if (Options.BranchInfo) {
+        FunctionLines::const_iterator FuncsIt = Line.Functions.find(LineIndex);
+        if (FuncsIt != Line.Functions.end())
+          printFunctionSummary(CovOS, FuncsIt->second);
+      }
+
+      BlockLines::const_iterator BlocksIt = Line.Blocks.find(LineIndex);
+      if (BlocksIt == Line.Blocks.end()) {
+        // No basic blocks are on this line. Not an executable line of code.
+        CovOS << "        -:";
+        AllLines.printNext(CovOS, LineIndex + 1);
       } else {
-        OS << "        -:";
+        const BlockVector &Blocks = BlocksIt->second;
+
+        // Add up the block counts to form line counts.
+        DenseMap<const GCOVFunction *, bool> LineExecs;
+        uint64_t LineCount = 0;
+        for (const GCOVBlock *Block : Blocks) {
+          if (Options.AllBlocks) {
+            // Only take the highest block count for that line.
+            uint64_t BlockCount = Block->getCount();
+            LineCount = LineCount > BlockCount ? LineCount : BlockCount;
+          } else {
+            // Sum up all of the block counts.
+            LineCount += Block->getCount();
+          }
+
+          if (Options.FuncCoverage) {
+            // This is a slightly convoluted way to most accurately gather line
+            // statistics for functions. Basically what is happening is that we
+            // don't want to count a single line with multiple blocks more than
+            // once. However, we also don't simply want to give the total line
+            // count to every function that starts on the line. Thus, what is
+            // happening here are two things:
+            // 1) Ensure that the number of logical lines is only incremented
+            //    once per function.
+            // 2) If there are multiple blocks on the same line, ensure that the
+            //    number of lines executed is incremented as long as at least
+            //    one of the blocks are executed.
+            const GCOVFunction *Function = &Block->getParent();
+            if (FuncCoverages.find(Function) == FuncCoverages.end()) {
+              std::pair<const GCOVFunction *, GCOVCoverage> KeyValue(
+                  Function, GCOVCoverage(Function->getName()));
+              FuncCoverages.insert(KeyValue);
+            }
+            GCOVCoverage &FuncCoverage = FuncCoverages.find(Function)->second;
+
+            if (LineExecs.find(Function) == LineExecs.end()) {
+              if (Block->getCount()) {
+                ++FuncCoverage.LinesExec;
+                LineExecs[Function] = true;
+              } else {
+                LineExecs[Function] = false;
+              }
+              ++FuncCoverage.LogicalLines;
+            } else if (!LineExecs[Function] && Block->getCount()) {
+              ++FuncCoverage.LinesExec;
+              LineExecs[Function] = true;
+            }
+          }
+        }
+
+        if (LineCount == 0)
+          CovOS << "    #####:";
+        else {
+          CovOS << format("%9" PRIu64 ":", LineCount);
+          ++FileCoverage.LinesExec;
+        }
+        ++FileCoverage.LogicalLines;
+
+        AllLines.printNext(CovOS, LineIndex + 1);
+
+        uint32_t BlockNo = 0;
+        uint32_t EdgeNo = 0;
+        for (const GCOVBlock *Block : Blocks) {
+          // Only print block and branch information at the end of the block.
+          if (Block->getLastLine() != LineIndex + 1)
+            continue;
+          if (Options.AllBlocks)
+            printBlockInfo(CovOS, *Block, LineIndex, BlockNo);
+          if (Options.BranchInfo) {
+            size_t NumEdges = Block->getNumDstEdges();
+            if (NumEdges > 1)
+              printBranchInfo(CovOS, *Block, FileCoverage, EdgeNo);
+            else if (Options.UncondBranch && NumEdges == 1)
+              printUncondBranchInfo(CovOS, EdgeNo,
+                                    (*Block->dst_begin())->Count);
+          }
+        }
       }
-      std::pair<StringRef, StringRef> P = AllLines.split('\n');
-      if (AllLines != P.first)
-        OS << format("%5u:", i+1) << P.first;
-      OS << "\n";
-      AllLines = P.second;
-      ++i;
     }
+    FileCoverages.push_back(std::make_pair(CoveragePath, FileCoverage));
   }
+
+  // FIXME: There is no way to detect calls given current instrumentation.
+  if (Options.FuncCoverage)
+    printFuncCoverage(InfoOS);
+  printFileCoverage(InfoOS);
+  return;
 }
 
+/// printFunctionSummary - Print function and block summary.
+void FileInfo::printFunctionSummary(raw_ostream &OS,
+                                    const FunctionVector &Funcs) const {
+  for (const GCOVFunction *Func : Funcs) {
+    uint64_t EntryCount = Func->getEntryCount();
+    uint32_t BlocksExec = 0;
+    for (const GCOVBlock &Block : Func->blocks())
+      if (Block.getNumDstEdges() && Block.getCount())
+        ++BlocksExec;
+
+    OS << "function " << Func->getName() << " called " << EntryCount
+       << " returned " << safeDiv(Func->getExitCount() * 100, EntryCount)
+       << "% blocks executed "
+       << safeDiv(BlocksExec * 100, Func->getNumBlocks() - 1) << "%\n";
+  }
+}
+
+/// printBlockInfo - Output counts for each block.
+void FileInfo::printBlockInfo(raw_ostream &OS, const GCOVBlock &Block,
+                              uint32_t LineIndex, uint32_t &BlockNo) const {
+  if (Block.getCount() == 0)
+    OS << "    $$$$$:";
+  else
+    OS << format("%9" PRIu64 ":", Block.getCount());
+  OS << format("%5u-block %2u\n", LineIndex + 1, BlockNo++);
+}
+
+/// printBranchInfo - Print conditional branch probabilities.
+void FileInfo::printBranchInfo(raw_ostream &OS, const GCOVBlock &Block,
+                               GCOVCoverage &Coverage, uint32_t &EdgeNo) {
+  SmallVector<uint64_t, 16> BranchCounts;
+  uint64_t TotalCounts = 0;
+  for (const GCOVEdge *Edge : Block.dsts()) {
+    BranchCounts.push_back(Edge->Count);
+    TotalCounts += Edge->Count;
+    if (Block.getCount())
+      ++Coverage.BranchesExec;
+    if (Edge->Count)
+      ++Coverage.BranchesTaken;
+    ++Coverage.Branches;
+
+    if (Options.FuncCoverage) {
+      const GCOVFunction *Function = &Block.getParent();
+      GCOVCoverage &FuncCoverage = FuncCoverages.find(Function)->second;
+      if (Block.getCount())
+        ++FuncCoverage.BranchesExec;
+      if (Edge->Count)
+        ++FuncCoverage.BranchesTaken;
+      ++FuncCoverage.Branches;
+    }
+  }
+
+  for (uint64_t N : BranchCounts)
+    OS << format("branch %2u ", EdgeNo++)
+       << formatBranchInfo(Options, N, TotalCounts) << "\n";
+}
+
+/// printUncondBranchInfo - Print unconditional branch probabilities.
+void FileInfo::printUncondBranchInfo(raw_ostream &OS, uint32_t &EdgeNo,
+                                     uint64_t Count) const {
+  OS << format("unconditional %2u ", EdgeNo++)
+     << formatBranchInfo(Options, Count, Count) << "\n";
+}
+
+// printCoverage - Print generic coverage info used by both printFuncCoverage
+// and printFileCoverage.
+void FileInfo::printCoverage(raw_ostream &OS,
+                             const GCOVCoverage &Coverage) const {
+  OS << format("Lines executed:%.2f%% of %u\n",
+               double(Coverage.LinesExec) * 100 / Coverage.LogicalLines,
+               Coverage.LogicalLines);
+  if (Options.BranchInfo) {
+    if (Coverage.Branches) {
+      OS << format("Branches executed:%.2f%% of %u\n",
+                   double(Coverage.BranchesExec) * 100 / Coverage.Branches,
+                   Coverage.Branches);
+      OS << format("Taken at least once:%.2f%% of %u\n",
+                   double(Coverage.BranchesTaken) * 100 / Coverage.Branches,
+                   Coverage.Branches);
+    } else {
+      OS << "No branches\n";
+    }
+    OS << "No calls\n"; // to be consistent with gcov
+  }
+}
+
+// printFuncCoverage - Print per-function coverage info.
+void FileInfo::printFuncCoverage(raw_ostream &OS) const {
+  for (const auto &FC : FuncCoverages) {
+    const GCOVCoverage &Coverage = FC.second;
+    OS << "Function '" << Coverage.Name << "'\n";
+    printCoverage(OS, Coverage);
+    OS << "\n";
+  }
+}
+
+// printFileCoverage - Print per-file coverage info.
+void FileInfo::printFileCoverage(raw_ostream &OS) const {
+  for (const auto &FC : FileCoverages) {
+    const std::string &Filename = FC.first;
+    const GCOVCoverage &Coverage = FC.second;
+    OS << "File '" << Coverage.Name << "'\n";
+    printCoverage(OS, Coverage);
+    if (!Options.NoOutput)
+      OS << Coverage.Name << ":creating '" << Filename << "'\n";
+    OS << "\n";
+  }
+}