Squashed 'src/leveldb/' changes from 04b5790928..4188247086

4188247086 Merge bitcoin-core/leveldb-subtree#47: Fix C++23 compilation errors in leveldb
183e79a495 Fix speculatively some "placement new" issues in leveldb
82c31046ed Fix C++23 compilation errors in leveldb

git-subtree-dir: src/leveldb
git-subtree-split: 41882470862df219f74cdd38354007b91eb98191
This commit is contained in:
fanquake 2025-03-17 15:59:05 +08:00
parent d336b7ab85
commit a130bbd154
3 changed files with 22 additions and 12 deletions

View file

@ -854,9 +854,13 @@ class SingletonEnv {
#endif // !defined(NDEBUG)
static_assert(sizeof(env_storage_) >= sizeof(EnvType),
"env_storage_ will not fit the Env");
static_assert(alignof(decltype(env_storage_)) >= alignof(EnvType),
static_assert(std::is_standard_layout_v<SingletonEnv<EnvType>>);
static_assert(
offsetof(SingletonEnv<EnvType>, env_storage_) % alignof(EnvType) == 0,
"env_storage_ does not meet the Env's alignment needs");
static_assert(alignof(SingletonEnv<EnvType>) % alignof(EnvType) == 0,
"env_storage_ does not meet the Env's alignment needs");
new (&env_storage_) EnvType();
new (env_storage_) EnvType();
}
~SingletonEnv() = default;
@ -872,8 +876,7 @@ class SingletonEnv {
}
private:
typename std::aligned_storage<sizeof(EnvType), alignof(EnvType)>::type
env_storage_;
alignas(EnvType) char env_storage_[sizeof(EnvType)];
#if !defined(NDEBUG)
static std::atomic<bool> env_initialized_;
#endif // !defined(NDEBUG)

View file

@ -802,9 +802,13 @@ class SingletonEnv {
#endif // !defined(NDEBUG)
static_assert(sizeof(env_storage_) >= sizeof(EnvType),
"env_storage_ will not fit the Env");
static_assert(alignof(decltype(env_storage_)) >= alignof(EnvType),
static_assert(std::is_standard_layout_v<SingletonEnv<EnvType>>);
static_assert(
offsetof(SingletonEnv<EnvType>, env_storage_) % alignof(EnvType) == 0,
"env_storage_ does not meet the Env's alignment needs");
static_assert(alignof(SingletonEnv<EnvType>) % alignof(EnvType) == 0,
"env_storage_ does not meet the Env's alignment needs");
new (&env_storage_) EnvType();
new (env_storage_) EnvType();
}
~SingletonEnv() = default;
@ -820,8 +824,7 @@ class SingletonEnv {
}
private:
typename std::aligned_storage<sizeof(EnvType), alignof(EnvType)>::type
env_storage_;
alignas(EnvType) char env_storage_[sizeof(EnvType)];
#if !defined(NDEBUG)
static std::atomic<bool> env_initialized_;
#endif // !defined(NDEBUG)

View file

@ -5,6 +5,7 @@
#ifndef STORAGE_LEVELDB_UTIL_NO_DESTRUCTOR_H_
#define STORAGE_LEVELDB_UTIL_NO_DESTRUCTOR_H_
#include <cstddef>
#include <type_traits>
#include <utility>
@ -20,10 +21,14 @@ class NoDestructor {
explicit NoDestructor(ConstructorArgTypes&&... constructor_args) {
static_assert(sizeof(instance_storage_) >= sizeof(InstanceType),
"instance_storage_ is not large enough to hold the instance");
static_assert(std::is_standard_layout_v<NoDestructor<InstanceType>>);
static_assert(
alignof(decltype(instance_storage_)) >= alignof(InstanceType),
offsetof(NoDestructor, instance_storage_) % alignof(InstanceType) == 0,
"instance_storage_ does not meet the instance's alignment requirement");
new (&instance_storage_)
static_assert(
alignof(NoDestructor<InstanceType>) % alignof(InstanceType) == 0,
"instance_storage_ does not meet the instance's alignment requirement");
new (instance_storage_)
InstanceType(std::forward<ConstructorArgTypes>(constructor_args)...);
}
@ -37,8 +42,7 @@ class NoDestructor {
}
private:
typename std::aligned_storage<sizeof(InstanceType),
alignof(InstanceType)>::type instance_storage_;
alignas(InstanceType) char instance_storage_[sizeof(InstanceType)];
};
} // namespace leveldb