Merge #10483: scripted-diff: Use the C++11 keyword nullptr to denote the pointer literal instead of the macro NULL

90d4d89 scripted-diff: Use the C++11 keyword nullptr to denote the pointer literal instead of the macro NULL (practicalswift)

Pull request description:

  Since C++11 the macro `NULL` may be:
  * an integer literal with value zero, or
  * a prvalue of type `std::nullptr_t`

  By using the C++11 keyword `nullptr` we are guaranteed a prvalue of type `std::nullptr_t`.

  For a more thorough discussion, see "A name for the null pointer: nullptr" (Sutter &
  Stroustrup), http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2431.pdf

  With this patch applied there are no `NULL` macro usages left in the repo:

  ```
  $ git grep NULL -- "*.cpp" "*.h" | egrep -v '(/univalue/|/secp256k1/|/leveldb/|_NULL|NULLDUMMY|torcontrol.*NULL|NULL cert)' | wc -l
  0
  ```

  The road towards `nullptr` (C++11) is split into two PRs:
  * `NULL` → `nullptr` is handled in PR #10483 (scripted, this PR)
  * `0` → `nullptr` is handled in PR #10645 (manual)

Tree-SHA512: 3c395d66f2ad724a8e6fed74b93634de8bfc0c0eafac94e64e5194c939499fefd6e68f047de3083ad0b4eff37df9a8a3a76349aa17d55eabbd8e0412f140a297

4 files changed, 5 insertions, 5 deletions

diff --git a/src/support/allocators/secure.h b/src/support/allocators/secure.h
index 9daba86ef3..f20f424941 100644
--- a/src/support/allocators/secure.h
+++ b/src/support/allocators/secure.h
@@ -45,7 +45,7 @@ struct secure_allocator : public std::allocator<T> {
 
     void deallocate(T* p, std::size_t n)
     {
-        if (p != NULL) {
+        if (p != nullptr) {
             memory_cleanse(p, sizeof(T) * n);
         }
         LockedPoolManager::Instance().free(p);
diff --git a/src/support/allocators/zeroafterfree.h b/src/support/allocators/zeroafterfree.h
index 28a940ad1b..581d5d6318 100644
--- a/src/support/allocators/zeroafterfree.h
+++ b/src/support/allocators/zeroafterfree.h
@@ -36,7 +36,7 @@ struct zero_after_free_allocator : public std::allocator<T> {
 
     void deallocate(T* p, std::size_t n)
     {
-        if (p != NULL)
+        if (p != nullptr)
             memory_cleanse(p, sizeof(T) * n);
         std::allocator<T>::deallocate(p, n);
     }
diff --git a/src/support/events.h b/src/support/events.h
index 90690876ee..cc6d29aecd 100644
--- a/src/support/events.h
+++ b/src/support/events.h
@@ -47,7 +47,7 @@ inline raii_evhttp_request obtain_evhttp_request(void(*cb)(struct evhttp_request
 }
 
 inline raii_evhttp_connection obtain_evhttp_connection_base(struct event_base* base, std::string host, uint16_t port) {
-    auto result = raii_evhttp_connection(evhttp_connection_base_new(base, NULL, host.c_str(), port));
+    auto result = raii_evhttp_connection(evhttp_connection_base_new(base, nullptr, host.c_str(), port));
     if (!result.get())
         throw std::runtime_error("create connection failed");
     return result;
diff --git a/src/support/lockedpool.cpp b/src/support/lockedpool.cpp
index 2df6b84a59..2ead72185f 100644
--- a/src/support/lockedpool.cpp
+++ b/src/support/lockedpool.cpp
@@ -28,7 +28,7 @@
 
 #include <algorithm>
 
-LockedPoolManager* LockedPoolManager::_instance = NULL;
+LockedPoolManager* LockedPoolManager::_instance = nullptr;
 std::once_flag LockedPoolManager::init_flag;
 
 /*******************************************************************************/
@@ -87,7 +87,7 @@ template <class Iterator, class Pair> bool extend(Iterator it, const Pair& other
 
 void Arena::free(void *ptr)
 {
-    // Freeing the NULL pointer is OK.
+    // Freeing the nullptr pointer is OK.
     if (ptr == nullptr) {
         return;
     }