Fix Clang-tidy modernize-use-nullptr warnings in examples and include directories; other minor cleanups.

Patch by Eugene Zelenko!

Differential Revision: http://reviews.llvm.org/D13172

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@248811 91177308-0d34-0410-b5e6-96231b3b80d8

15 files changed, 49 insertions, 54 deletions

diff --git a/examples/BrainF/BrainF.cpp b/examples/BrainF/BrainF.cpp
index 8026adc8d07..d8c54b50b85 100644
--- a/examples/BrainF/BrainF.cpp
+++ b/examples/BrainF/BrainF.cpp
@@ -29,6 +29,7 @@
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/Intrinsics.h"
 #include <iostream>
+
 using namespace llvm;
 
 //Set the constants for naming
@@ -44,7 +45,7 @@ Module *BrainF::parse(std::istream *in1, int mem, CompileFlags cf,
   comflag  = cf;
 
   header(Context);
-  readloop(0, 0, 0, Context);
+  readloop(nullptr, nullptr, nullptr, Context);
   delete builder;
   return module;
 }
@@ -68,7 +69,6 @@ void BrainF::header(LLVMContext& C) {
     getOrInsertFunction("putchar", IntegerType::getInt32Ty(C),
                         IntegerType::getInt32Ty(C), NULL));
 
-
   //Function header
 
   //define void @brainf()
@@ -85,7 +85,7 @@ void BrainF::header(LLVMContext& C) {
   Constant* allocsize = ConstantExpr::getSizeOf(Int8Ty);
   allocsize = ConstantExpr::getTruncOrBitCast(allocsize, IntPtrTy);
   ptr_arr = CallInst::CreateMalloc(BB, IntPtrTy, Int8Ty, allocsize, val_mem, 
-                                   NULL, "arr");
+                                   nullptr, "arr");
   BB->getInstList().push_back(cast<Instruction>(ptr_arr));
 
   //call void @llvm.memset.p0i8.i32(i8 *%arr, i8 0, i32 %d, i32 1, i1 0)
@@ -114,8 +114,6 @@ void BrainF::header(LLVMContext& C) {
                                ConstantInt::get(C, APInt(32, memtotal/2)),
                                headreg);
 
-
-
   //Function footer
 
   //brainf.end:
@@ -127,8 +125,6 @@ void BrainF::header(LLVMContext& C) {
   //ret void
   ReturnInst::Create(C, endbb);
 
-
-
   //Error block for array out of bounds
   if (comflag & flag_arraybounds)
   {
diff --git a/examples/Fibonacci/fibonacci.cpp b/examples/Fibonacci/fibonacci.cpp
index 8092e19380d..a628cee53ff 100644
--- a/examples/Fibonacci/fibonacci.cpp
+++ b/examples/Fibonacci/fibonacci.cpp
@@ -33,6 +33,7 @@
 #include "llvm/IR/Module.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Support/raw_ostream.h"
+
 using namespace llvm;
 
 static Function *CreateFibFunction(Module *M, LLVMContext &Context) {
@@ -41,7 +42,7 @@ static Function *CreateFibFunction(Module *M, LLVMContext &Context) {
   Function *FibF =
     cast<Function>(M->getOrInsertFunction("fib", Type::getInt32Ty(Context),
                                           Type::getInt32Ty(Context),
-                                          (Type *)0));
+                                          nullptr));
 
   // Add a basic block to the function.
   BasicBlock *BB = BasicBlock::Create(Context, "EntryBlock", FibF);
@@ -87,7 +88,6 @@ static Function *CreateFibFunction(Module *M, LLVMContext &Context) {
   return FibF;
 }
 
-
 int main(int argc, char **argv) {
   int n = argc > 1 ? atol(argv[1]) : 24;
 
diff --git a/examples/HowToUseJIT/HowToUseJIT.cpp b/examples/HowToUseJIT/HowToUseJIT.cpp
index 91ea17dd22b..e5fca3fe98d 100644
--- a/examples/HowToUseJIT/HowToUseJIT.cpp
+++ b/examples/HowToUseJIT/HowToUseJIT.cpp
@@ -65,7 +65,7 @@ int main() {
   Function *Add1F =
     cast<Function>(M->getOrInsertFunction("add1", Type::getInt32Ty(Context),
                                           Type::getInt32Ty(Context),
-                                          (Type *)0));
+                                          nullptr));
 
   // Add a basic block to the function. As before, it automatically inserts
   // because of the last argument.
@@ -91,12 +91,11 @@ int main() {
 
   // Now, function add1 is ready.
 
-
   // Now we're going to create function `foo', which returns an int and takes no
   // arguments.
   Function *FooF =
     cast<Function>(M->getOrInsertFunction("foo", Type::getInt32Ty(Context),
-                                          (Type *)0));
+                                          nullptr));
 
   // Add a basic block to the FooF function.
   BB = BasicBlock::Create(Context, "EntryBlock", FooF);
diff --git a/examples/Kaleidoscope/Chapter2/toy.cpp b/examples/Kaleidoscope/Chapter2/toy.cpp
index 14cba32f5f9..bcba554b246 100644
--- a/examples/Kaleidoscope/Chapter2/toy.cpp
+++ b/examples/Kaleidoscope/Chapter2/toy.cpp
@@ -53,7 +53,7 @@ static int gettok() {
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
diff --git a/examples/Kaleidoscope/Chapter3/toy.cpp b/examples/Kaleidoscope/Chapter3/toy.cpp
index 328189c1184..05697ea70a4 100644
--- a/examples/Kaleidoscope/Chapter3/toy.cpp
+++ b/examples/Kaleidoscope/Chapter3/toy.cpp
@@ -8,6 +8,7 @@
 #include <map>
 #include <string>
 #include <vector>
+
 using namespace llvm;
 
 //===----------------------------------------------------------------------===//
@@ -58,7 +59,7 @@ static int gettok() {
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
@@ -193,6 +194,7 @@ std::unique_ptr<ExprAST> Error(const char *Str) {
   fprintf(stderr, "Error: %s\n", Str);
   return nullptr;
 }
+
 std::unique_ptr<PrototypeAST> ErrorP(const char *Str) {
   Error(Str);
   return nullptr;
diff --git a/examples/Kaleidoscope/Chapter4/toy.cpp b/examples/Kaleidoscope/Chapter4/toy.cpp
index 8c96444ad40..4f77ec862b1 100644
--- a/examples/Kaleidoscope/Chapter4/toy.cpp
+++ b/examples/Kaleidoscope/Chapter4/toy.cpp
@@ -65,7 +65,7 @@ static int gettok() {
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
@@ -200,6 +200,7 @@ std::unique_ptr<ExprAST> Error(const char *Str) {
   fprintf(stderr, "Error: %s\n", Str);
   return nullptr;
 }
+
 std::unique_ptr<PrototypeAST> ErrorP(const char *Str) {
   Error(Str);
   return nullptr;
diff --git a/examples/Kaleidoscope/Chapter5/toy.cpp b/examples/Kaleidoscope/Chapter5/toy.cpp
index 57edf1aa845..eeca4775eeb 100644
--- a/examples/Kaleidoscope/Chapter5/toy.cpp
+++ b/examples/Kaleidoscope/Chapter5/toy.cpp
@@ -82,7 +82,7 @@ static int gettok() {
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
@@ -242,6 +242,7 @@ std::unique_ptr<ExprAST> Error(const char *Str) {
   fprintf(stderr, "Error: %s\n", Str);
   return nullptr;
 }
+
 std::unique_ptr<PrototypeAST> ErrorP(const char *Str) {
   Error(Str);
   return nullptr;
diff --git a/examples/Kaleidoscope/Chapter6/toy.cpp b/examples/Kaleidoscope/Chapter6/toy.cpp
index 0b4ef3dbb98..4d04f7e888a 100644
--- a/examples/Kaleidoscope/Chapter6/toy.cpp
+++ b/examples/Kaleidoscope/Chapter6/toy.cpp
@@ -90,7 +90,7 @@ static int gettok() {
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
@@ -275,6 +275,7 @@ std::unique_ptr<ExprAST> Error(const char *Str) {
   fprintf(stderr, "Error: %s\n", Str);
   return nullptr;
 }
+
 std::unique_ptr<PrototypeAST> ErrorP(const char *Str) {
   Error(Str);
   return nullptr;
diff --git a/examples/Kaleidoscope/Chapter7/toy.cpp b/examples/Kaleidoscope/Chapter7/toy.cpp
index cf3fbdf15da..5c0094013d9 100644
--- a/examples/Kaleidoscope/Chapter7/toy.cpp
+++ b/examples/Kaleidoscope/Chapter7/toy.cpp
@@ -95,7 +95,7 @@ static int gettok() {
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
@@ -294,6 +294,7 @@ std::unique_ptr<ExprAST> Error(const char *Str) {
   fprintf(stderr, "Error: %s\n", Str);
   return nullptr;
 }
+
 std::unique_ptr<PrototypeAST> ErrorP(const char *Str) {
   Error(Str);
   return nullptr;
@@ -703,7 +704,7 @@ static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
                                           const std::string &VarName) {
   IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
                    TheFunction->getEntryBlock().begin());
-  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
+  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), nullptr,
                            VarName.c_str());
 }
 
diff --git a/examples/Kaleidoscope/Chapter8/toy.cpp b/examples/Kaleidoscope/Chapter8/toy.cpp
index b78d901db2d..d58dadf08bb 100644
--- a/examples/Kaleidoscope/Chapter8/toy.cpp
+++ b/examples/Kaleidoscope/Chapter8/toy.cpp
@@ -163,7 +163,7 @@ static int gettok() {
       LastChar = advance();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
@@ -431,6 +431,7 @@ std::unique_ptr<ExprAST> Error(const char *Str) {
   fprintf(stderr, "Error: %s\n", Str);
   return nullptr;
 }
+
 std::unique_ptr<PrototypeAST> ErrorP(const char *Str) {
   Error(Str);
   return nullptr;
@@ -886,7 +887,7 @@ static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
                                           const std::string &VarName) {
   IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
                    TheFunction->getEntryBlock().begin());
-  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
+  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), nullptr,
                            VarName.c_str());
 }
 
diff --git a/examples/Kaleidoscope/Orc/fully_lazy/toy.cpp b/examples/Kaleidoscope/Orc/fully_lazy/toy.cpp
index 7e5b38cafe7..667bca46afd 100644
--- a/examples/Kaleidoscope/Orc/fully_lazy/toy.cpp
+++ b/examples/Kaleidoscope/Orc/fully_lazy/toy.cpp
@@ -87,7 +87,7 @@ static int gettok() {
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
@@ -387,7 +387,6 @@ static std::unique_ptr<ForExprAST> ParseForExpr() {
     return ErrorU<ForExprAST>("expected '=' after for");
   getNextToken();  // eat '='.
 
-
   auto Start = ParseExpression();
   if (!Start)
     return nullptr;
@@ -748,7 +747,7 @@ static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
                                           const std::string &VarName) {
   IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
                  TheFunction->getEntryBlock().begin());
-  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
+  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), nullptr,
                            VarName.c_str());
 }
 
@@ -760,7 +759,7 @@ Value *VariableExprAST::IRGen(IRGenContext &C) const {
   // Look this variable up in the function.
   Value *V = C.NamedValues[Name];
 
-  if (V == 0)
+  if (!V)
     return ErrorP<Value>("Unknown variable name '" + Name + "'");
 
   // Load the value.
@@ -960,7 +959,7 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
 
   // Compute the end condition.
   Value *EndCond = End->IRGen(C);
-  if (EndCond == 0) return EndCond;
+  if (!EndCond) return nullptr;
 
   // Reload, increment, and restore the alloca.  This handles the case where
   // the body of the loop mutates the variable.
@@ -988,7 +987,6 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
   else
     C.NamedValues.erase(VarName);
 
-
   // for expr always returns 0.0.
   return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
 }
@@ -1236,7 +1234,7 @@ private:
   RuntimeDyld::SymbolInfo searchFunctionASTs(const std::string &Name) {
     auto DefI = FunctionDefs.find(Name);
     if (DefI == FunctionDefs.end())
-      return 0;
+      return nullptr;
 
     // Return the address of the stub.
     // Take the FunctionAST out of the map.
diff --git a/examples/Kaleidoscope/Orc/initial/toy.cpp b/examples/Kaleidoscope/Orc/initial/toy.cpp
index 662c871904c..8dab73bf73a 100644
--- a/examples/Kaleidoscope/Orc/initial/toy.cpp
+++ b/examples/Kaleidoscope/Orc/initial/toy.cpp
@@ -86,7 +86,7 @@ static int gettok() {
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
@@ -386,7 +386,6 @@ static std::unique_ptr<ForExprAST> ParseForExpr() {
     return ErrorU<ForExprAST>("expected '=' after for");
   getNextToken();  // eat '='.
 
-
   auto Start = ParseExpression();
   if (!Start)
     return nullptr;
@@ -747,7 +746,7 @@ static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
                                           const std::string &VarName) {
   IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
                  TheFunction->getEntryBlock().begin());
-  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
+  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), nullptr,
                            VarName.c_str());
 }
 
@@ -759,7 +758,7 @@ Value *VariableExprAST::IRGen(IRGenContext &C) const {
   // Look this variable up in the function.
   Value *V = C.NamedValues[Name];
 
-  if (V == 0)
+  if (!V)
     return ErrorP<Value>("Unknown variable name '" + Name + "'");
 
   // Load the value.
@@ -959,7 +958,7 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
 
   // Compute the end condition.
   Value *EndCond = End->IRGen(C);
-  if (EndCond == 0) return EndCond;
+  if (!EndCond) return nullptr;
 
   // Reload, increment, and restore the alloca.  This handles the case where
   // the body of the loop mutates the variable.
@@ -987,7 +986,6 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
   else
     C.NamedValues.erase(VarName);
 
-
   // for expr always returns 0.0.
   return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
 }
diff --git a/examples/Kaleidoscope/Orc/lazy_codegen/toy.cpp b/examples/Kaleidoscope/Orc/lazy_codegen/toy.cpp
index fc71849bebb..f5a6c19614b 100644
--- a/examples/Kaleidoscope/Orc/lazy_codegen/toy.cpp
+++ b/examples/Kaleidoscope/Orc/lazy_codegen/toy.cpp
@@ -86,7 +86,7 @@ static int gettok() {
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
@@ -386,7 +386,6 @@ static std::unique_ptr<ForExprAST> ParseForExpr() {
     return ErrorU<ForExprAST>("expected '=' after for");
   getNextToken();  // eat '='.
 
-
   auto Start = ParseExpression();
   if (!Start)
     return nullptr;
@@ -747,7 +746,7 @@ static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
                                           const std::string &VarName) {
   IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
                  TheFunction->getEntryBlock().begin());
-  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
+  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), nullptr,
                            VarName.c_str());
 }
 
@@ -759,7 +758,7 @@ Value *VariableExprAST::IRGen(IRGenContext &C) const {
   // Look this variable up in the function.
   Value *V = C.NamedValues[Name];
 
-  if (V == 0)
+  if (!V)
     return ErrorP<Value>("Unknown variable name '" + Name + "'");
 
   // Load the value.
@@ -959,7 +958,7 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
 
   // Compute the end condition.
   Value *EndCond = End->IRGen(C);
-  if (EndCond == 0) return EndCond;
+  if (!EndCond) return nullptr;
 
   // Reload, increment, and restore the alloca.  This handles the case where
   // the body of the loop mutates the variable.
@@ -987,7 +986,6 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
   else
     C.NamedValues.erase(VarName);
 
-
   // for expr always returns 0.0.
   return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
 }
diff --git a/examples/Kaleidoscope/Orc/lazy_irgen/toy.cpp b/examples/Kaleidoscope/Orc/lazy_irgen/toy.cpp
index a1779c7e1bf..f9b972e8294 100644
--- a/examples/Kaleidoscope/Orc/lazy_irgen/toy.cpp
+++ b/examples/Kaleidoscope/Orc/lazy_irgen/toy.cpp
@@ -86,7 +86,7 @@ static int gettok() {
       LastChar = getchar();
     } while (isdigit(LastChar) || LastChar == '.');
 
-    NumVal = strtod(NumStr.c_str(), 0);
+    NumVal = strtod(NumStr.c_str(), nullptr);
     return tok_number;
   }
 
@@ -386,7 +386,6 @@ static std::unique_ptr<ForExprAST> ParseForExpr() {
     return ErrorU<ForExprAST>("expected '=' after for");
   getNextToken();  // eat '='.
 
-
   auto Start = ParseExpression();
   if (!Start)
     return nullptr;
@@ -747,7 +746,7 @@ static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
                                           const std::string &VarName) {
   IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
                  TheFunction->getEntryBlock().begin());
-  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
+  return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), nullptr,
                            VarName.c_str());
 }
 
@@ -759,7 +758,7 @@ Value *VariableExprAST::IRGen(IRGenContext &C) const {
   // Look this variable up in the function.
   Value *V = C.NamedValues[Name];
 
-  if (V == 0)
+  if (!V)
     return ErrorP<Value>("Unknown variable name '" + Name + "'");
 
   // Load the value.
@@ -959,7 +958,7 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
 
   // Compute the end condition.
   Value *EndCond = End->IRGen(C);
-  if (EndCond == 0) return EndCond;
+  if (!EndCond) return nullptr;
 
   // Reload, increment, and restore the alloca.  This handles the case where
   // the body of the loop mutates the variable.
@@ -987,7 +986,6 @@ Value *ForExprAST::IRGen(IRGenContext &C) const {
   else
     C.NamedValues.erase(VarName);
 
-
   // for expr always returns 0.0.
   return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
 }
@@ -1223,7 +1221,7 @@ private:
   RuntimeDyld::SymbolInfo searchFunctionASTs(const std::string &Name) {
     auto DefI = FunctionDefs.find(Name);
     if (DefI == FunctionDefs.end())
-      return 0;
+      return nullptr;
 
     // Take the FunctionAST out of the map.
     auto FnAST = std::move(DefI->second);
diff --git a/examples/ParallelJIT/ParallelJIT.cpp b/examples/ParallelJIT/ParallelJIT.cpp
index b2c53a9bb10..27ea8b1419f 100644
--- a/examples/ParallelJIT/ParallelJIT.cpp
+++ b/examples/ParallelJIT/ParallelJIT.cpp
@@ -28,6 +28,7 @@
 #include "llvm/Support/TargetSelect.h"
 #include <iostream>
 #include <pthread.h>
+
 using namespace llvm;
 
 static Function* createAdd1(Module *M) {
@@ -38,7 +39,7 @@ static Function* createAdd1(Module *M) {
     cast<Function>(M->getOrInsertFunction("add1",
                                           Type::getInt32Ty(M->getContext()),
                                           Type::getInt32Ty(M->getContext()),
-                                          (Type *)0));
+                                          nullptr));
 
   // Add a basic block to the function. As before, it automatically inserts
   // because of the last argument.
@@ -69,7 +70,7 @@ static Function *CreateFibFunction(Module *M) {
     cast<Function>(M->getOrInsertFunction("fib",
                                           Type::getInt32Ty(M->getContext()),
                                           Type::getInt32Ty(M->getContext()),
-                                          (Type *)0));
+                                          nullptr));
 
   // Add a basic block to the function.
   BasicBlock *BB = BasicBlock::Create(M->getContext(), "EntryBlock", FibF);
@@ -129,10 +130,10 @@ public:
     n = 0;
     waitFor = 0;
 
-    int result = pthread_cond_init( &condition, NULL );
+    int result = pthread_cond_init( &condition, nullptr );
     assert( result == 0 );
 
-    result = pthread_mutex_init( &mutex, NULL );
+    result = pthread_mutex_init( &mutex, nullptr );
     assert( result == 0 );
   }
 
@@ -261,21 +262,21 @@ int main() {
   struct threadParams fib2 = { EE, fibF, 42 };
 
   pthread_t add1Thread;
-  int result = pthread_create( &add1Thread, NULL, callFunc, &add1 );
+  int result = pthread_create( &add1Thread, nullptr, callFunc, &add1 );
   if ( result != 0 ) {
           std::cerr << "Could not create thread" << std::endl;
           return 1;
   }
 
   pthread_t fibThread1;
-  result = pthread_create( &fibThread1, NULL, callFunc, &fib1 );
+  result = pthread_create( &fibThread1, nullptr, callFunc, &fib1 );
   if ( result != 0 ) {
           std::cerr << "Could not create thread" << std::endl;
           return 1;
   }
 
   pthread_t fibThread2;
-  result = pthread_create( &fibThread2, NULL, callFunc, &fib2 );
+  result = pthread_create( &fibThread2, nullptr, callFunc, &fib2 );
   if ( result != 0 ) {
           std::cerr << "Could not create thread" << std::endl;
           return 1;