[Clang] Fix Clang-tidy modernize-use-nullptr warnings; other minor fixes

[Eugene.Zelenko]

Summary

I checked this patch on my own build on RHEL 6. Regressions were OK.

[aaron.ballman]

LGTM!

include/clang/ASTMatchers/ASTMatchersInternal.h

   template <typename From>
   Matcher(const Matcher<From> &Other,
           typename std::enable_if<std::is_base_of<From, T>::value &&
-                                  !std::is_same<From, T>::value>::type * = 0)
+                               !std::is_same<From, T>::value>::type * = nullptr)
       : Implementation(restrictMatcher(Other.Implementation)) {
     assert(Implementation.getSupportedKind().isSame(
         ast_type_traits::ASTNodeKind::getFromNodeKind<T>()));

   Matcher(const Matcher<TypeT> &Other,
           typename std::enable_if<
             std::is_same<T, QualType>::value &&
-            std::is_same<TypeT, Type>::value>::type* = 0)
+            std::is_same<TypeT, Type>::value>::type* = nullptr)
       : Implementation(new TypeToQualType<TypeT>(Other)) {}
 
   /// \brief Convert \c this into a \c Matcher<T> by applying dyn_cast<> to the

 } // end namespace ast_matchers
 } // end namespace clang
 
-#endif
+#endif // LLVM_CLANG_ASTMATCHERS_ASTMATCHERSINTERNAL_H

include/clang/Sema/DeclSpec.h

     I.Kind          = Pipe;
     I.Loc           = Loc;
     I.Cls.TypeQuals = TypeQuals;
-    I.Cls.AttrList  = 0;
+    I.Cls.AttrList  = nullptr;
     return I;
   }
 

 
 } // end namespace clang
 
-#endif
+#endif // LLVM_CLANG_SEMA_DECLSPEC_H

lib/ASTMatchers/Dynamic/Marshallers.h

-//===--- Marshallers.h - Generic matcher function marshallers -*- C++ -*-===//
+//===--- Marshallers.h - Generic matcher function marshallers ---*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //

 namespace dynamic {
 namespace internal {
 
-
 /// \brief Helper template class to just from argument type to the right is/get
 ///   functions in VariantValue.
 /// Used to verify and extract the matcher arguments below.

 template <typename T>
 static VariantMatcher outvalueToVariantMatcher(const T &PolyMatcher,
                                                typename T::ReturnTypes * =
-                                                   NULL) {
+                                                   nullptr) {
   std::vector<DynTypedMatcher> Matchers;
   mergePolyMatchers(PolyMatcher, Matchers, typename T::ReturnTypes());
   VariantMatcher Out = VariantMatcher::PolymorphicMatcher(std::move(Matchers));

     return VariantMatcher();                                                   \
   }
 
-
 /// \brief 0-arg marshaller function.
 template <typename ReturnType>
 static VariantMatcher matcherMarshall0(void (*Func)(), StringRef MatcherName,

                                                MatcherName);
 }
 
-}  // namespace internal
-}  // namespace dynamic
-}  // namespace ast_matchers
-}  // namespace clang
+} // namespace internal
+} // namespace dynamic
+} // namespace ast_matchers
+} // namespace clang
 
-#endif  // LLVM_CLANG_AST_MATCHERS_DYNAMIC_MARSHALLERS_H
+#endif // LLVM_CLANG_AST_MATCHERS_DYNAMIC_MARSHALLERS_H

lib/CodeGen/CGOpenMPRuntime.cpp

       CGM.getTypes().ConvertTypeForMem(getTgtOffloadEntryQTy());
   llvm::GlobalVariable *HostEntriesBegin = new llvm::GlobalVariable(
       M, OffloadEntryTy, /*isConstant=*/true,
-      llvm::GlobalValue::ExternalLinkage, /*Initializer=*/0,
+      llvm::GlobalValue::ExternalLinkage, /*Initializer=*/nullptr,
       ".omp_offloading.entries_begin");
   llvm::GlobalVariable *HostEntriesEnd = new llvm::GlobalVariable(
       M, OffloadEntryTy, /*isConstant=*/true,
-      llvm::GlobalValue::ExternalLinkage, /*Initializer=*/0,
+      llvm::GlobalValue::ExternalLinkage, /*Initializer=*/nullptr,
       ".omp_offloading.entries_end");
 
   // Create all device images

     StringRef T = Devices[i].getTriple();
     auto *ImgBegin = new llvm::GlobalVariable(
         M, CGM.Int8Ty, /*isConstant=*/true, llvm::GlobalValue::ExternalLinkage,
-        /*Initializer=*/0, Twine(".omp_offloading.img_start.") + Twine(T));
+        /*Initializer=*/nullptr,
+        Twine(".omp_offloading.img_start.") + Twine(T));
     auto *ImgEnd = new llvm::GlobalVariable(
         M, CGM.Int8Ty, /*isConstant=*/true, llvm::GlobalValue::ExternalLinkage,
-        /*Initializer=*/0, Twine(".omp_offloading.img_end.") + Twine(T));
+        /*Initializer=*/nullptr, Twine(".omp_offloading.img_end.") + Twine(T));
 
     llvm::Constant *Dev =
         llvm::ConstantStruct::get(DeviceImageTy, ImgBegin, ImgEnd,

lib/Sema/SemaType.cpp

       savedAttrs.back()->setNext(nullptr);
     }
   };
-}
+} // end anonymous namespace
 
 static void spliceAttrIntoList(AttributeList &attr, AttributeList *&head) {
   attr.setNext(head);

 ///
 /// The values of this enum are used in diagnostics.
 enum QualifiedFunctionKind { QFK_BlockPointer, QFK_Pointer, QFK_Reference };
-}
+} // end anonymous namespace
 
 /// Check whether the type T is a qualified function type, and if it is,
 /// diagnose that it cannot be contained within the given kind of declarator.

                                            S.LangOpts.GNUMode).isInvalid();
 }
 
-
 /// \brief Build an array type.
 ///
 /// \param T The type of each element in the array.

     BlockPointer,
     MemberPointer,
   };
-}
+} // end anonymous namespace
 
 IdentifierInfo *Sema::getNullabilityKeyword(NullabilityKind nullability) {
   switch (nullability) {

     // NSError**
     NSErrorPointerPointer,
   };
-}
+} // end anonymous namespace
 
 /// Classify the given declarator, whose type-specified is \c type, based on
 /// what kind of pointer it refers to.

     break;
   } while (true);
 
-
   switch (numNormalPointers) {
   case 0:
     return PointerDeclaratorKind::NonPointer;

       T = S.BuildPointerType(T, DeclType.Loc, Name);
       if (DeclType.Ptr.TypeQuals)
         T = S.BuildQualifiedType(T, DeclType.Loc, DeclType.Ptr.TypeQuals);
-
       break;
     case DeclaratorChunk::Reference: {
       // Verify that we're not building a reference to pointer to function with

 
         T = Context.getFunctionType(T, ParamTys, EPI);
       }
-
       break;
     }
     case DeclaratorChunk::MemberPointer: {

     void VisitPipeTypeLoc(PipeTypeLoc TL) {
       TL.setKWLoc(DS.getTypeSpecTypeLoc());
 
-      TypeSourceInfo *TInfo = 0;
+      TypeSourceInfo *TInfo = nullptr;
       Sema::GetTypeFromParser(DS.getRepAsType(), &TInfo);
       TL.getValueLoc().initializeFullCopy(TInfo->getTypeLoc());
     }

       llvm_unreachable("unsupported TypeLoc kind in declarator!");
     }
   };
-}
+} // end anonymous namespace
 
 static void fillAtomicQualLoc(AtomicTypeLoc ATL, const DeclaratorChunk &Chunk) {
   SourceLocation Loc;

   return CreateParsedType(T, TInfo);
 }
 
-
 //===----------------------------------------------------------------------===//
 // Type Attribute Processing
 //===----------------------------------------------------------------------===//

       llvm_unreachable("unknown wrapping kind");
     }
   };
-}
+} // end anonymous namespace
 
 static bool handleMSPointerTypeQualifierAttr(TypeProcessingState &State,
                                              AttributeList &Attr,

lib/StaticAnalyzer/Checkers/VforkChecker.cpp

   bool isCallWhitelisted(const IdentifierInfo *II, CheckerContext &C) const;
 
   void reportBug(const char *What, CheckerContext &C,
-                 const char *Details = 0) const;
+                 const char *Details = nullptr) const;
 
 public:
-  VforkChecker() : II_vfork(0) {}
+  VforkChecker() : II_vfork(nullptr) {}
 
   void checkPreCall(const CallEvent &Call, CheckerContext &C) const;
   void checkPostCall(const CallEvent &Call, CheckerContext &C) const;

       "execv",
       "execvp",
       "execvpe",
-      0,
+      nullptr
     };
 
     ASTContext &AC = C.getASTContext();

lib/StaticAnalyzer/Core/CheckerHelpers.cpp

 // Extract lhs and rhs from assignment statement
 std::pair<const clang::VarDecl *, const clang::Expr *>
 clang::ento::parseAssignment(const Stmt *S) {
-  const VarDecl *VD = 0;
-  const Expr *RHS = 0;
+  const VarDecl *VD = nullptr;
+  const Expr *RHS = nullptr;
 
   if (auto Assign = dyn_cast_or_null<BinaryOperator>(S)) {
     if (Assign->isAssignmentOp()) {

unittests/Basic/VirtualFileSystemTest.cpp

             bool IsVolatile) override {
     llvm_unreachable("unimplemented");
   }
-  virtual std::error_code close() override { return std::error_code(); }
+  std::error_code close() override { return std::error_code(); }
 };
 
 class DummyFileSystem : public vfs::FileSystem {

   ASSERT_FALSE(EC);
   ASSERT_NE(vfs::recursive_directory_iterator(), I);
 
-
   std::vector<std::string> Contents;
   for (auto E = vfs::recursive_directory_iterator(); !EC && I != E;
        I.increment(EC)) {