[BOLT] Towards FunctionLayout const-correctness

A const-qualified reference to function layout allows accessing
non-const qualified basic blocks on a const-qualified function. This
patch adds or removes const-qualifiers where necessary to indicate where
basic blocks are used in a non-const manner.

Reviewed By: rafauler

Differential Revision: https://reviews.llvm.org/D132049

bolt/include/bolt/Core/BinaryBasicBlock.h

@@ -424,6 +424,9 @@ public:
   /// Return branch info corresponding to an edge going to \p Succ basic block.
   BinaryBranchInfo &getBranchInfo(const BinaryBasicBlock &Succ);
 
+  /// Return branch info corresponding to an edge going to \p Succ basic block.
+  const BinaryBranchInfo &getBranchInfo(const BinaryBasicBlock &Succ) const;
+
   /// Return branch info corresponding to an edge going to a basic block with
   /// label \p Label.
   BinaryBranchInfo &getBranchInfo(const MCSymbol *Label);

bolt/include/bolt/Core/BinaryFunction.h

@@ -1599,7 +1599,7 @@ public:
 
   /// Print function information to the \p OS stream.
   void print(raw_ostream &OS, std::string Annotation = "",
-             bool PrintInstructions = true) const;
+             bool PrintInstructions = true);
 
   /// Print all relocations between \p Offset and \p Offset + \p Size in
   /// this function.

bolt/include/bolt/Core/DynoStats.h

@@ -142,11 +142,11 @@ DynoStats operator+(const DynoStats &A, const DynoStats &B);
 /// The function relies on branch instructions being in-sync with CFG for
 /// branch instructions stats. Thus it is better to call it after
 /// fixBranches().
-DynoStats getDynoStats(const BinaryFunction &BF);
+DynoStats getDynoStats(BinaryFunction &BF);
 
 /// Return program-wide dynostats.
 template <typename FuncsType>
-inline DynoStats getDynoStats(const FuncsType &Funcs, bool IsAArch64) {
+inline DynoStats getDynoStats(FuncsType &Funcs, bool IsAArch64) {
   DynoStats dynoStats(IsAArch64);
   for (auto &BFI : Funcs) {
     auto &BF = BFI.second;
@@ -158,9 +158,8 @@ inline DynoStats getDynoStats(const FuncsType &Funcs, bool IsAArch64) {
 
 /// Call a function with optional before and after dynostats printing.
 template <typename FnType, typename FuncsType>
-inline void callWithDynoStats(FnType &&Func, const FuncsType &Funcs,
-                              StringRef Phase, const bool Flag,
-                              bool IsAArch64) {
+inline void callWithDynoStats(FnType &&Func, FuncsType &Funcs, StringRef Phase,
+                              const bool Flag, bool IsAArch64) {
   DynoStats DynoStatsBefore(IsAArch64);
   if (Flag)
     DynoStatsBefore = getDynoStats(Funcs, IsAArch64);

bolt/include/bolt/Passes/ReorderAlgorithm.h

@@ -39,7 +39,7 @@ public:
   /// Clusters vector. Also encode relative weights between two clusters in
   /// the ClusterEdges vector if requested. This vector is indexed by
   /// the clusters indices in the Clusters vector.
-  virtual void clusterBasicBlocks(const BinaryFunction &BF,
+  virtual void clusterBasicBlocks(BinaryFunction &BF,
                                   bool ComputeEdges = false) = 0;
 
   /// Compute for each cluster its averagae execution frequency, that is
@@ -98,7 +98,7 @@ protected:
   BBToClusterMapTy BBToClusterMap;
 
 public:
-  void clusterBasicBlocks(const BinaryFunction &BF,
+  void clusterBasicBlocks(BinaryFunction &BF,
                           bool ComputeEdges = false) override;
   void reset() override;
 };
@@ -167,7 +167,7 @@ public:
 
   /// Reorder the basic blocks of the given function and store the new order in
   /// the new Clusters vector.
-  virtual void reorderBasicBlocks(const BinaryFunction &BF,
+  virtual void reorderBasicBlocks(BinaryFunction &BF,
                                   BasicBlockOrder &Order) const = 0;
 
   void setClusterAlgorithm(ClusterAlgorithm *CAlgo) {
@@ -185,7 +185,7 @@ public:
 /// only be used for small functions.
 class TSPReorderAlgorithm : public ReorderAlgorithm {
 public:
-  void reorderBasicBlocks(const BinaryFunction &BF,
+  void reorderBasicBlocks(BinaryFunction &BF,
                           BasicBlockOrder &Order) const override;
 };
 
@@ -196,7 +196,7 @@ public:
   explicit OptimizeReorderAlgorithm(std::unique_ptr<ClusterAlgorithm> CAlgo)
       : ReorderAlgorithm(std::move(CAlgo)) {}
 
-  void reorderBasicBlocks(const BinaryFunction &BF,
+  void reorderBasicBlocks(BinaryFunction &BF,
                           BasicBlockOrder &Order) const override;
 };
 
@@ -209,7 +209,7 @@ public:
       std::unique_ptr<ClusterAlgorithm> CAlgo)
       : ReorderAlgorithm(std::move(CAlgo)) {}
 
-  void reorderBasicBlocks(const BinaryFunction &BF,
+  void reorderBasicBlocks(BinaryFunction &BF,
                           BasicBlockOrder &Order) const override;
 };
 
@@ -222,21 +222,21 @@ public:
       std::unique_ptr<ClusterAlgorithm> CAlgo)
       : ReorderAlgorithm(std::move(CAlgo)) {}
 
-  void reorderBasicBlocks(const BinaryFunction &BF,
+  void reorderBasicBlocks(BinaryFunction &BF,
                           BasicBlockOrder &Order) const override;
 };
 
 /// A new reordering algorithm for basic blocks, ext-tsp
 class ExtTSPReorderAlgorithm : public ReorderAlgorithm {
 public:
-  void reorderBasicBlocks(const BinaryFunction &BF,
+  void reorderBasicBlocks(BinaryFunction &BF,
                           BasicBlockOrder &Order) const override;
 };
 
 /// Toy example that simply reverses the original basic block order.
 class ReverseReorderAlgorithm : public ReorderAlgorithm {
 public:
-  void reorderBasicBlocks(const BinaryFunction &BF,
+  void reorderBasicBlocks(BinaryFunction &BF,
                           BasicBlockOrder &Order) const override;
 };
 
@@ -247,7 +247,7 @@ public:
       std::unique_ptr<ClusterAlgorithm> CAlgo)
       : ReorderAlgorithm(std::move(CAlgo)) {}
 
-  void reorderBasicBlocks(const BinaryFunction &BF,
+  void reorderBasicBlocks(BinaryFunction &BF,
                           BasicBlockOrder &Order) const override;
 };
 

bolt/lib/Core/BinaryBasicBlock.cpp

@@ -581,15 +581,17 @@ uint64_t BinaryBasicBlock::estimateSize(const MCCodeEmitter *Emitter) const {
 
 BinaryBasicBlock::BinaryBranchInfo &
 BinaryBasicBlock::getBranchInfo(const BinaryBasicBlock &Succ) {
-  auto BI = branch_info_begin();
-  for (BinaryBasicBlock *BB : successors()) {
-    if (&Succ == BB)
-      return *BI;
-    ++BI;
-  }
+  return const_cast<BinaryBranchInfo &>(
+      static_cast<const BinaryBasicBlock &>(*this).getBranchInfo(Succ));
+}
 
-  llvm_unreachable("Invalid successor");
-  return *BI;
+const BinaryBasicBlock::BinaryBranchInfo &
+BinaryBasicBlock::getBranchInfo(const BinaryBasicBlock &Succ) const {
+  const auto Zip = llvm::zip(successors(), branch_info());
+  const auto Result = llvm::find_if(
+      Zip, [&](const auto &Tuple) { return std::get<0>(Tuple) == &Succ; });
+  assert(Result != Zip.end() && "Cannot find target in successors");
+  return std::get<1>(*Result);
 }
 
 BinaryBasicBlock::BinaryBranchInfo &

bolt/lib/Core/BinaryFunction.cpp

@@ -396,11 +396,20 @@ bool BinaryFunction::isForwardCall(const MCSymbol *CalleeSymbol) const {
 }
 
 void BinaryFunction::dump(bool PrintInstructions) const {
-  print(dbgs(), "", PrintInstructions);
+  // getDynoStats calls FunctionLayout::updateLayoutIndices and
+  // BasicBlock::analyzeBranch. The former cannot be const, but should be
+  // removed, the latter should be made const, but seems to require refactoring.
+  // Forcing all callers to have a non-const reference to BinaryFunction to call
+  // dump non-const however is not ideal either. Adding this const_cast is right
+  // now the best solution. It is safe, because BinaryFunction itself is not
+  // modified. Only BinaryBasicBlocks are actually modified (if it all) and we
+  // have mutable pointers to those regardless whether this function is
+  // const-qualified or not.
+  const_cast<BinaryFunction &>(*this).print(dbgs(), "", PrintInstructions);
 }
 
 void BinaryFunction::print(raw_ostream &OS, std::string Annotation,
-                           bool PrintInstructions) const {
+                           bool PrintInstructions) {
   if (!opts::shouldPrint(*this))
     return;
 
@@ -3558,9 +3567,9 @@ size_t BinaryFunction::computeHash(bool UseDFS,
 
   assert(hasCFG() && "function is expected to have CFG");
 
-  BasicBlockListType Order;
+  SmallVector<const BinaryBasicBlock *, 0> Order;
   if (UseDFS)
-    Order = dfs();
+    llvm::copy(dfs(), std::back_inserter(Order));
   else
     llvm::copy(Layout.blocks(), std::back_inserter(Order));
 

bolt/lib/Core/DynoStats.cpp

@@ -158,7 +158,7 @@ void DynoStats::operator+=(const DynoStats &Other) {
   }
 }
 
-DynoStats getDynoStats(const BinaryFunction &BF) {
+DynoStats getDynoStats(BinaryFunction &BF) {
   auto &BC = BF.getBinaryContext();
 
   DynoStats Stats(/*PrintAArch64Stats*/ BC.isAArch64());

bolt/lib/Passes/AsmDump.cpp

@@ -195,7 +195,7 @@ void dumpFunction(const BinaryFunction &BF) {
   std::unordered_set<const MCSymbol *> CallReferences;
 
   MAP->OutStreamer->emitCFIStartProc(/*IsSimple=*/false);
-  for (BinaryBasicBlock *BB : BF.getLayout().blocks()) {
+  for (const BinaryBasicBlock *BB : BF.getLayout().blocks()) {
     OS << BB->getName() << ": \n";
 
     const std::string BranchLabel = Twine(BB->getName(), "_br").str();

bolt/lib/Passes/BinaryPasses.cpp

@@ -1450,11 +1450,11 @@ void PrintProgramStats::runOnFunctions(BinaryContext &BC) {
   if (!opts::PrintSortedBy.empty() &&
       !llvm::is_contained(opts::PrintSortedBy, DynoStats::FIRST_DYNO_STAT)) {
 
-    std::vector<const BinaryFunction *> Functions;
+    std::vector<BinaryFunction *> Functions;
     std::map<const BinaryFunction *, DynoStats> Stats;
 
-    for (const auto &BFI : BC.getBinaryFunctions()) {
-      const BinaryFunction &BF = BFI.second;
+    for (auto &BFI : BC.getBinaryFunctions()) {
+      BinaryFunction &BF = BFI.second;
       if (shouldOptimize(BF) && BF.hasValidProfile()) {
         Functions.push_back(&BF);
         Stats.emplace(&BF, getDynoStats(BF));
@@ -1554,9 +1554,9 @@ void PrintProgramStats::runOnFunctions(BinaryContext &BC) {
 
   // Collect and print information about suboptimal code layout on input.
   if (opts::ReportBadLayout) {
-    std::vector<const BinaryFunction *> SuboptimalFuncs;
+    std::vector<BinaryFunction *> SuboptimalFuncs;
     for (auto &BFI : BC.getBinaryFunctions()) {
-      const BinaryFunction &BF = BFI.second;
+      BinaryFunction &BF = BFI.second;
       if (!BF.hasValidProfile())
         continue;
 

bolt/lib/Passes/CacheMetrics.cpp

@@ -117,9 +117,9 @@ extractFunctionCalls(const std::vector<BinaryFunction *> &BinaryFunctions) {
 
   for (BinaryFunction *SrcFunction : BinaryFunctions) {
     const BinaryContext &BC = SrcFunction->getBinaryContext();
-    for (BinaryBasicBlock *BB : SrcFunction->getLayout().blocks()) {
+    for (const BinaryBasicBlock *BB : SrcFunction->getLayout().blocks()) {
       // Find call instructions and extract target symbols from each one
-      for (MCInst &Inst : *BB) {
+      for (const MCInst &Inst : *BB) {
         if (!BC.MIB->isCall(Inst))
           continue;
 

bolt/lib/Passes/ExtTSPReorderAlgorithm.cpp

@@ -441,7 +441,7 @@ bool compareChainPairs(const Chain *A1, const Chain *B1, const Chain *A2,
 }
 class ExtTSP {
 public:
-  ExtTSP(const BinaryFunction &BF) : BF(BF) { initialize(); }
+  ExtTSP(BinaryFunction &BF) : BF(BF) { initialize(); }
 
   /// Run the algorithm and return an ordering of basic block
   void run(BinaryFunction::BasicBlockOrderType &Order) {
@@ -849,7 +849,7 @@ private:
 
 private:
   // The binary function
-  const BinaryFunction &BF;
+  BinaryFunction &BF;
 
   // All CFG nodes (basic blocks)
   std::vector<Block> AllBlocks;
@@ -864,7 +864,7 @@ private:
   std::vector<Edge> AllEdges;
 };
 
-void ExtTSPReorderAlgorithm::reorderBasicBlocks(const BinaryFunction &BF,
+void ExtTSPReorderAlgorithm::reorderBasicBlocks(BinaryFunction &BF,
                                                 BasicBlockOrder &Order) const {
   if (BF.getLayout().block_empty())
     return;

bolt/lib/Passes/IdenticalCodeFolding.cpp

@@ -12,10 +12,12 @@
 
 #include "bolt/Passes/IdenticalCodeFolding.h"
 #include "bolt/Core/ParallelUtilities.h"
+#include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/ThreadPool.h"
 #include "llvm/Support/Timer.h"
 #include <atomic>
+#include <iterator>
 #include <map>
 #include <set>
 #include <unordered_map>
@@ -166,16 +168,15 @@ bool isIdenticalWith(const BinaryFunction &A, const BinaryFunction &B,
     return false;
 
   // Process both functions in either DFS or existing order.
-  const BinaryFunction::BasicBlockOrderType OrderA =
-      opts::UseDFS
-          ? A.dfs()
-          : BinaryFunction::BasicBlockOrderType(A.getLayout().block_begin(),
-                                                A.getLayout().block_end());
-  const BinaryFunction::BasicBlockOrderType OrderB =
-      opts::UseDFS
-          ? B.dfs()
-          : BinaryFunction::BasicBlockOrderType(B.getLayout().block_begin(),
-                                                B.getLayout().block_end());
+  SmallVector<const BinaryBasicBlock *, 0> OrderA;
+  SmallVector<const BinaryBasicBlock *, 0> OrderB;
+  if (opts::UseDFS) {
+    copy(A.dfs(), std::back_inserter(OrderA));
+    copy(B.dfs(), std::back_inserter(OrderB));
+  } else {
+    copy(A.getLayout().blocks(), std::back_inserter(OrderA));
+    copy(B.getLayout().blocks(), std::back_inserter(OrderB));
+  }
 
   const BinaryContext &BC = A.getBinaryContext();
 

bolt/lib/Passes/ReorderAlgorithm.cpp

@@ -75,7 +75,7 @@ void ClusterAlgorithm::computeClusterAverageFrequency(const BinaryContext &BC) {
   for (uint32_t I = 0, E = Clusters.size(); I < E; ++I) {
     double Freq = 0.0;
     uint64_t ClusterSize = 0;
-    for (BinaryBasicBlock *BB : Clusters[I]) {
+    for (const BinaryBasicBlock *BB : Clusters[I]) {
       if (BB->getNumNonPseudos() > 0) {
         Freq += BB->getExecutionCount();
         // Estimate the size of a block in bytes at run time
@@ -94,7 +94,7 @@ void ClusterAlgorithm::printClusters() const {
       errs() << " (frequency: " << AvgFreq[I] << ")";
     errs() << " : ";
     const char *Sep = "";
-    for (BinaryBasicBlock *BB : Clusters[I]) {
+    for (const BinaryBasicBlock *BB : Clusters[I]) {
       errs() << Sep << BB->getName();
       Sep = ", ";
     }
@@ -122,7 +122,7 @@ bool GreedyClusterAlgorithm::EdgeEqual::operator()(const EdgeTy &A,
   return A.Src == B.Src && A.Dst == B.Dst;
 }
 
-void GreedyClusterAlgorithm::clusterBasicBlocks(const BinaryFunction &BF,
+void GreedyClusterAlgorithm::clusterBasicBlocks(BinaryFunction &BF,
                                                 bool ComputeEdges) {
   reset();
 
@@ -148,7 +148,7 @@ void GreedyClusterAlgorithm::clusterBasicBlocks(const BinaryFunction &BF,
     BBToClusterMap[BB] = I;
     // Populate priority queue with edges.
     auto BI = BB->branch_info_begin();
-    for (BinaryBasicBlock *&I : BB->successors()) {
+    for (const BinaryBasicBlock *I : BB->successors()) {
       assert(BI->Count != BinaryBasicBlock::COUNT_NO_PROFILE &&
              "attempted reordering blocks of function with no profile data");
       Queue.emplace_back(EdgeTy(BB, I, BI->Count));
@@ -191,7 +191,7 @@ void GreedyClusterAlgorithm::clusterBasicBlocks(const BinaryFunction &BF,
     if (areClustersCompatible(ClusterA, ClusterB, E)) {
       // Case 3: SrcBB is at the end of a cluster and DstBB is at the start,
       // allowing us to merge two clusters.
-      for (BinaryBasicBlock *BB : ClusterB)
+      for (const BinaryBasicBlock *BB : ClusterB)
         BBToClusterMap[BB] = I;
       ClusterA.insert(ClusterA.end(), ClusterB.begin(), ClusterB.end());
       ClusterB.clear();
@@ -398,7 +398,7 @@ void MinBranchGreedyClusterAlgorithm::reset() {
   Weight.clear();
 }
 
-void TSPReorderAlgorithm::reorderBasicBlocks(const BinaryFunction &BF,
+void TSPReorderAlgorithm::reorderBasicBlocks(BinaryFunction &BF,
                                              BasicBlockOrder &Order) const {
   std::vector<std::vector<uint64_t>> Weight;
   std::vector<BinaryBasicBlock *> IndexToBB;
@@ -413,7 +413,7 @@ void TSPReorderAlgorithm::reorderBasicBlocks(const BinaryFunction &BF,
     IndexToBB.push_back(BB);
   }
   Weight.resize(N);
-  for (BinaryBasicBlock *BB : BF.getLayout().blocks()) {
+  for (const BinaryBasicBlock *BB : BF.getLayout().blocks()) {
     auto BI = BB->branch_info_begin();
     Weight[BB->getLayoutIndex()].resize(N);
     for (BinaryBasicBlock *SuccBB : BB->successors()) {
@@ -501,7 +501,7 @@ void TSPReorderAlgorithm::reorderBasicBlocks(const BinaryFunction &BF,
 }
 
 void OptimizeReorderAlgorithm::reorderBasicBlocks(
-    const BinaryFunction &BF, BasicBlockOrder &Order) const {
+    BinaryFunction &BF, BasicBlockOrder &Order) const {
   if (BF.getLayout().block_empty())
     return;
 
@@ -517,7 +517,7 @@ void OptimizeReorderAlgorithm::reorderBasicBlocks(
 }
 
 void OptimizeBranchReorderAlgorithm::reorderBasicBlocks(
-    const BinaryFunction &BF, BasicBlockOrder &Order) const {
+    BinaryFunction &BF, BasicBlockOrder &Order) const {
   if (BF.getLayout().block_empty())
     return;
 
@@ -622,7 +622,7 @@ void OptimizeBranchReorderAlgorithm::reorderBasicBlocks(
 }
 
 void OptimizeCacheReorderAlgorithm::reorderBasicBlocks(
-    const BinaryFunction &BF, BasicBlockOrder &Order) const {
+    BinaryFunction &BF, BasicBlockOrder &Order) const {
   if (BF.getLayout().block_empty())
     return;
 
@@ -675,7 +675,7 @@ void OptimizeCacheReorderAlgorithm::reorderBasicBlocks(
   }
 }
 
-void ReverseReorderAlgorithm::reorderBasicBlocks(const BinaryFunction &BF,
+void ReverseReorderAlgorithm::reorderBasicBlocks(BinaryFunction &BF,
                                                  BasicBlockOrder &Order) const {
   if (BF.getLayout().block_empty())
     return;
@@ -687,7 +687,7 @@ void ReverseReorderAlgorithm::reorderBasicBlocks(const BinaryFunction &BF,
 }
 
 void RandomClusterReorderAlgorithm::reorderBasicBlocks(
-    const BinaryFunction &BF, BasicBlockOrder &Order) const {
+    BinaryFunction &BF, BasicBlockOrder &Order) const {
   if (BF.getLayout().block_empty())
     return;
 

bolt/lib/Passes/StokeInfo.cpp

@@ -46,11 +46,11 @@ void getRegNameFromBitVec(const BinaryContext &BC, const BitVector &RegV,
 void StokeInfo::checkInstr(const BinaryFunction &BF, StokeFuncInfo &FuncInfo) {
   MCPlusBuilder *MIB = BF.getBinaryContext().MIB.get();
   BitVector RegV(NumRegs, false);
-  for (BinaryBasicBlock *BB : BF.getLayout().blocks()) {
+  for (const BinaryBasicBlock *BB : BF.getLayout().blocks()) {
     if (BB->empty())
       continue;
 
-    for (MCInst &It : *BB) {
+    for (const MCInst &It : *BB) {
       if (MIB->isPseudo(It))
         continue;
       // skip function with exception handling yet

bolt/lib/Profile/DataAggregator.cpp

@@ -865,8 +865,8 @@ bool DataAggregator::recordTrace(
   if (From > To)
     return false;
 
-  BinaryBasicBlock *FromBB = BF.getBasicBlockContainingOffset(From);
-  BinaryBasicBlock *ToBB = BF.getBasicBlockContainingOffset(To);
+  const BinaryBasicBlock *FromBB = BF.getBasicBlockContainingOffset(From);
+  const BinaryBasicBlock *ToBB = BF.getBasicBlockContainingOffset(To);
 
   if (!FromBB || !ToBB)
     return false;
@@ -875,7 +875,8 @@ bool DataAggregator::recordTrace(
   // the previous block (that instruction should be a call).
   if (From == FromBB->getOffset() && !BF.containsAddress(FirstLBR.From) &&
       !FromBB->isEntryPoint() && !FromBB->isLandingPad()) {
-    BinaryBasicBlock *PrevBB = BF.getLayout().getBlock(FromBB->getIndex() - 1);
+    const BinaryBasicBlock *PrevBB =
+        BF.getLayout().getBlock(FromBB->getIndex() - 1);
     if (PrevBB->getSuccessor(FromBB->getLabel())) {
       const MCInst *Instr = PrevBB->getLastNonPseudoInstr();
       if (Instr && BC.MIB->isCall(*Instr))

bolt/lib/Profile/DataReader.cpp

@@ -674,7 +674,7 @@ bool DataReader::recordBranch(BinaryFunction &BF, uint64_t From, uint64_t To,
   BinaryContext &BC = BF.getBinaryContext();
 
   BinaryBasicBlock *FromBB = BF.getBasicBlockContainingOffset(From);
-  BinaryBasicBlock *ToBB = BF.getBasicBlockContainingOffset(To);
+  const BinaryBasicBlock *ToBB = BF.getBasicBlockContainingOffset(To);
 
   if (!FromBB || !ToBB) {
     LLVM_DEBUG(dbgs() << "failed to get block for recorded branch\n");
@@ -703,7 +703,7 @@ bool DataReader::recordBranch(BinaryFunction &BF, uint64_t From, uint64_t To,
   if (!OffsetMatches) {
     // Skip the nops to support old .fdata
     uint64_t Offset = ToBB->getOffset();
-    for (MCInst &Instr : *ToBB) {
+    for (const MCInst &Instr : *ToBB) {
       if (!BC.MIB->isNoop(Instr))
         break;
 
@@ -739,7 +739,8 @@ bool DataReader::recordBranch(BinaryFunction &BF, uint64_t From, uint64_t To,
     // The real destination is the layout successor of the detected ToBB.
     if (ToBB == BF.getLayout().block_back())
       return false;
-    BinaryBasicBlock *NextBB = BF.getLayout().getBlock(ToBB->getIndex() + 1);
+    const BinaryBasicBlock *NextBB =
+        BF.getLayout().getBlock(ToBB->getIndex() + 1);
     assert((NextBB && NextBB->getOffset() > ToBB->getOffset()) && "bad layout");
     ToBB = NextBB;
   }

bolt/lib/Rewrite/BoltDiff.cpp

@@ -183,7 +183,7 @@ class RewriteInstanceDiff {
            RI1.getTotalScore();
   }
 
-  double getNormalizedScore(BinaryBasicBlock::branch_info_iterator BIIter,
+  double getNormalizedScore(BinaryBasicBlock::const_branch_info_iterator BIIter,
                             const RewriteInstance &Ctx) {
     double Score =
         BIIter->Count == BinaryBasicBlock::COUNT_NO_PROFILE ? 0 : BIIter->Count;