Fix Clang-tidy modernize-use-nullptr and modernize-use-override warnings; other minor fixes.

Differential revision: reviews.llvm.org/D16568

llvm-svn: 258831
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 59e736c..36650db 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -35,6 +35,7 @@
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/raw_ostream.h"
 #include <deque>
+
 using namespace llvm;
 
 namespace {
@@ -497,7 +498,7 @@
   std::error_code initStreamFromBuffer();
   std::error_code initLazyStream(std::unique_ptr<DataStreamer> Streamer);
 };
-} // namespace
+} // end anonymous namespace
 
 BitcodeDiagnosticInfo::BitcodeDiagnosticInfo(std::error_code EC,
                                              DiagnosticSeverity Severity,
@@ -872,7 +873,7 @@
   /// Provide fast operand accessors
   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
 };
-}
+} // end anonymous namespace
 
 // FIXME: can we inherit this from ConstantExpr?
 template <>
@@ -880,7 +881,7 @@
   public FixedNumOperandTraits<ConstantPlaceHolder, 1> {
 };
 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantPlaceHolder, Value)
-}
+} // end namespace llvm
 
 void BitcodeReaderValueList::assignValue(Value *V, unsigned Idx) {
   if (Idx == size()) {
@@ -908,11 +909,8 @@
     OldV->replaceAllUsesWith(V);
     delete PrevVal;
   }
-
-  return;
 }
 
-
 Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
                                                     Type *Ty) {
   if (Idx >= size())
@@ -1129,7 +1127,6 @@
   return Ret;
 }
 
-
 //===----------------------------------------------------------------------===//
 //  Functions for parsing blocks from the bitcode file
 //===----------------------------------------------------------------------===//
@@ -2178,7 +2175,7 @@
               getMDOrNull(Record[9]), getMDOrNull(Record[10]),
               getMDOrNull(Record[11]), getMDOrNull(Record[12]),
               getMDOrNull(Record[13]),
-              Record.size() <= 15 ? 0 : getMDOrNull(Record[15]),
+              Record.size() <= 15 ? nullptr : getMDOrNull(Record[15]),
               Record.size() <= 14 ? 0 : Record[14]),
           NextMetadataNo++);
       break;
@@ -2701,7 +2698,6 @@
       }
       break;
     }
-
     case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
       if (Record.size() < 3)
         return error("Invalid record");
@@ -3375,7 +3371,6 @@
       break;
     }
 
-
     // Read a record.
     auto BitCode = Stream.readRecord(Entry.ID, Record);
     switch (BitCode) {
@@ -5816,7 +5811,7 @@
     llvm_unreachable("Unknown error type!");
   }
 };
-}
+} // end anonymous namespace
 
 static ManagedStatic<BitcodeErrorCategoryType> ErrorCategory;
 
diff --git a/llvm/lib/ProfileData/InstrProf.cpp b/llvm/lib/ProfileData/InstrProf.cpp
index 8482b18..00deec6 100644
--- a/llvm/lib/ProfileData/InstrProf.cpp
+++ b/llvm/lib/ProfileData/InstrProf.cpp
@@ -65,7 +65,7 @@
     llvm_unreachable("A value of instrprof_error has no message.");
   }
 };
-}
+} // end anonymous namespace
 
 static ManagedStatic<InstrProfErrorCategoryType> ErrorCategory;
 
@@ -443,12 +443,12 @@
 }
 
 static ValueProfRecordClosure InstrProfRecordClosure = {
-    0,
+    nullptr,
     getNumValueKindsInstrProf,
     getNumValueSitesInstrProf,
     getNumValueDataInstrProf,
     getNumValueDataForSiteInstrProf,
-    0,
+    nullptr,
     getValueForSiteInstrProf,
     allocValueProfDataInstrProf};
 
@@ -638,7 +638,6 @@
     ProfileSummaryEntry PSE = {Cutoff, Count, BlocksSeen};
     DetailedSummary.push_back(PSE);
   }
-  return;
 }
 
-}
+} // end namespace llvm
diff --git a/llvm/lib/Support/Unix/Memory.inc b/llvm/lib/Support/Unix/Memory.inc
index d703191..f3463e5 100644
--- a/llvm/lib/Support/Unix/Memory.inc
+++ b/llvm/lib/Support/Unix/Memory.inc
@@ -73,7 +73,7 @@
   return PROT_NONE;
 }
 
-} // namespace
+} // anonymous namespace
 
 namespace llvm {
 namespace sys {
@@ -265,7 +265,7 @@
 }
 
 bool Memory::setExecutable (MemoryBlock &M, std::string *ErrMsg) {
-  if (M.Address == 0 || M.Size == 0) return false;
+  if (M.Address == nullptr || M.Size == 0) return false;
   Memory::InvalidateInstructionCache(M.Address, M.Size);
 #if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
   kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)M.Address,
diff --git a/llvm/lib/Target/X86/X86ISelLowering.h b/llvm/lib/Target/X86/X86ISelLowering.h
index 3f87a49..6e48a2d 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.h
+++ b/llvm/lib/Target/X86/X86ISelLowering.h
@@ -556,7 +556,7 @@
       // have memop! In fact, starting from ATOMADD64_DAG all opcodes will be
       // thought as target memory ops!
     };
-  }
+  } // end namespace X86ISD
 
   /// Define some predicates that are used for node matching.
   namespace X86 {
@@ -608,13 +608,12 @@
     bool isOffsetSuitableForCodeModel(int64_t Offset, CodeModel::Model M,
                                       bool hasSymbolicDisplacement = true);
 
-
     /// Determines whether the callee is required to pop its
     /// own arguments. Callee pop is necessary to support tail calls.
     bool isCalleePop(CallingConv::ID CallingConv,
                      bool is64Bit, bool IsVarArg, bool GuaranteeTCO);
 
-  }
+  } // end namespace X86
 
   //===--------------------------------------------------------------------===//
   //  X86 Implementation of the TargetLowering interface
@@ -685,9 +684,9 @@
     /// and types must exactly match those of the original return values of
     /// the node), or leaves Results empty, which indicates that the node is not
     /// to be custom lowered after all.
-    virtual void LowerOperationWrapper(SDNode *N,
-                                       SmallVectorImpl<SDValue> &Results,
-                                       SelectionDAG &DAG) const override;
+    void LowerOperationWrapper(SDNode *N,
+                               SmallVectorImpl<SDValue> &Results,
+                               SelectionDAG &DAG) const override;
 
     /// Replace the results of node with an illegal result
     /// type with new values built out of custom code.
@@ -695,7 +694,6 @@
     void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue>&Results,
                             SelectionDAG &DAG) const override;
 
-
     SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const override;
 
     /// Return true if the target has native support for
@@ -1180,7 +1178,7 @@
   namespace X86 {
     FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
                              const TargetLibraryInfo *libInfo);
-  }
-}
+  } // end namespace X86
+} // end namespace llvm
 
-#endif    // X86ISELLOWERING_H
+#endif // LLVM_LIB_TARGET_X86_X86ISELLOWERING_H
diff --git a/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp b/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
index 64aa94f..f9e421d 100644
--- a/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
+++ b/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
@@ -257,7 +257,7 @@
 
     if (CreateGlobalVar)
       FuncNameVar = createPGOFuncNameVar(F, FuncName);
-  };
+  }
 };
 
 // Compute Hash value for the CFG: the lower 32 bits are CRC32 of the index
@@ -690,7 +690,7 @@
       const PGOUseEdge *E = BBCountInfo.OutEdges[s];
       const BasicBlock *SrcBB = E->SrcBB;
       const BasicBlock *DestBB = E->DestBB;
-      if (DestBB == 0)
+      if (DestBB == nullptr)
         continue;
       unsigned SuccNum = GetSuccessorNumber(SrcBB, DestBB);
       uint64_t EdgeCount = E->CountValue;
diff --git a/llvm/lib/Transforms/Utils/AddDiscriminators.cpp b/llvm/lib/Transforms/Utils/AddDiscriminators.cpp
index 0262358..3e585c6 100644
--- a/llvm/lib/Transforms/Utils/AddDiscriminators.cpp
+++ b/llvm/lib/Transforms/Utils/AddDiscriminators.cpp
@@ -80,7 +80,7 @@
 
   bool runOnFunction(Function &F) override;
 };
-}
+} // end anonymous namespace
 
 char AddDiscriminators::ID = 0;
 INITIALIZE_PASS_BEGIN(AddDiscriminators, "add-discriminators",
@@ -217,7 +217,7 @@
   // Sample base profile needs to distinguish different function calls within
   // a same source line for correct profile annotation.
   for (BasicBlock &B : F) {
-    const DILocation *FirstDIL = NULL;
+    const DILocation *FirstDIL = nullptr;
     for (auto &I : B.getInstList()) {
       CallInst *Current = dyn_cast<CallInst>(&I);
       if (!Current || isa<DbgInfoIntrinsic>(&I))
diff --git a/llvm/lib/Transforms/Utils/SanitizerStats.cpp b/llvm/lib/Transforms/Utils/SanitizerStats.cpp
index af3df2f..9afd175 100644
--- a/llvm/lib/Transforms/Utils/SanitizerStats.cpp
+++ b/llvm/lib/Transforms/Utils/SanitizerStats.cpp
@@ -27,7 +27,7 @@
   EmptyModuleStatsTy = makeModuleStatsTy();
 
   ModuleStatsGV = new GlobalVariable(*M, EmptyModuleStatsTy, false,
-                                     GlobalValue::InternalLinkage, 0);
+                                     GlobalValue::InternalLinkage, nullptr);
 }
 
 ArrayType *SanitizerStatReport::makeModuleStatsArrayTy() {