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.venv/Lib/site-packages/pyarrow/include/arrow/util/ubsan.h

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+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+// Contains utilities for making UBSan happy.
+
+#pragma once
+
+#include <cstring>
+#include <memory>
+#include <type_traits>
+
+#include "arrow/util/macros.h"
+
+namespace arrow {
+namespace util {
+
+namespace internal {
+
+constexpr uint8_t kNonNullFiller = 0;
+
+}  // namespace internal
+
+/// \brief Returns maybe_null if not null or a non-null pointer to an arbitrary memory
+/// that shouldn't be dereferenced.
+///
+/// Memset/Memcpy are undefined when a nullptr is passed as an argument use this utility
+/// method to wrap locations where this could happen.
+///
+/// Note: Flatbuffers has UBSan warnings if a zero length vector is passed.
+/// https://github.com/google/flatbuffers/pull/5355 is trying to resolve
+/// them.
+template <typename T>
+inline T* MakeNonNull(T* maybe_null = NULLPTR) {
+  if (ARROW_PREDICT_TRUE(maybe_null != NULLPTR)) {
+    return maybe_null;
+  }
+
+  return const_cast<T*>(reinterpret_cast<const T*>(&internal::kNonNullFiller));
+}
+
+template <typename T>
+inline typename std::enable_if<std::is_trivial<T>::value, T>::type SafeLoadAs(
+    const uint8_t* unaligned) {
+  typename std::remove_const<T>::type ret;
+  std::memcpy(&ret, unaligned, sizeof(T));
+  return ret;
+}
+
+template <typename T>
+inline typename std::enable_if<std::is_trivial<T>::value, T>::type SafeLoad(
+    const T* unaligned) {
+  typename std::remove_const<T>::type ret;
+  std::memcpy(&ret, unaligned, sizeof(T));
+  return ret;
+}
+
+template <typename U, typename T>
+inline typename std::enable_if<std::is_trivial<T>::value && std::is_trivial<U>::value &&
+                                   sizeof(T) == sizeof(U),
+                               U>::type
+SafeCopy(T value) {
+  typename std::remove_const<U>::type ret;
+  std::memcpy(&ret, &value, sizeof(T));
+  return ret;
+}
+
+template <typename T>
+inline typename std::enable_if<std::is_trivial<T>::value, void>::type SafeStore(
+    void* unaligned, T value) {
+  std::memcpy(unaligned, &value, sizeof(T));
+}
+
+}  // namespace util
+}  // namespace arrow