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authorGravatar Abseil Team <absl-team@google.com>2020-02-21 12:51:36 -0800
committerGravatar CJ Johnson <johnsoncj@google.com>2020-02-21 15:56:04 -0500
commitb69c7d880caddfc25bf348dbcfe9d45fdd8bc6e6 (patch)
tree0ceef2d75071fdfdf7a47c2978a4df5b422001ed
parent2a5633fc077a58528cdbfe78720f3f6bfdc6044d (diff)
Export of internal Abseil changes
-- 00f5301405423005d9129935c05f20155536cc1a by CJ Johnson <johnsoncj@google.com>: Removes usage of std::aligned_storage from Abseil implementation details PiperOrigin-RevId: 296492301 -- fc11d15f91764612fba080669d2381dc181df52b by Abseil Team <absl-team@google.com>: Fix absl::bind_front documentation. PiperOrigin-RevId: 296482945 -- 0164c595c129c46bf21ae74eba5399a1da5f140b by Gennadiy Rozental <rogeeff@google.com>: Automated g4 rollback of changelist 296320700. PiperOrigin-RevId: 296439968 -- 1eb295700758ca0894d872b2de7c675b4ad679af by Abseil Team <absl-team@google.com>: Removes duplicate comments. PiperOrigin-RevId: 296433214 -- c30c01caae02d2fa4ef783d988de6bebb9757c39 by Derek Mauro <dmauro@google.com>: Merge GitHub #621: Add RISCV support to GetProgramCounter() Fixes #621 PiperOrigin-RevId: 296351174 -- 95d4498167596fd7543e025bdfe9a8da9e2ca3c8 by Abseil Team <absl-team@google.com>: Automated g4 rollback of changelist 296320700. PiperOrigin-RevId: 296348701 -- b193f0543e0cec54dddb2ed51f45dc489c8d06d5 by Gennadiy Rozental <rogeeff@google.com>: Change TryParse interface to return managed value. In addition introduce companion StoreValue routine which consumes pointer to source value and stores the value inside of FlagImpl. In a follow up CL we will change StoreValue implementation to behave differently depending on "value storage kind". We also rename default_src_ to default_value_. PiperOrigin-RevId: 296320700 -- 57e942b485d12912a0a8d0d0b35fa2a62847020f by Derek Mauro <dmauro@google.com>: Merge GitHub #622 * Add missing #ifdef conditionals for ABSL_HAVE_VDSO_SUPPORT PiperOrigin-RevId: 296272830 GitOrigin-RevId: 00f5301405423005d9129935c05f20155536cc1a Change-Id: I1b05eeaf1280f95fb0a2c5f3654995a87c792893
-rw-r--r--absl/base/exception_safety_testing_test.cc18
-rw-r--r--absl/base/internal/low_level_alloc.cc13
-rw-r--r--absl/base/options.h8
-rw-r--r--absl/container/fixed_array_test.cc7
-rw-r--r--absl/container/internal/common.h7
-rw-r--r--absl/container/internal/raw_hash_set.h6
-rw-r--r--absl/debugging/internal/stacktrace_x86-inl.inc4
-rw-r--r--absl/flags/internal/flag.cc81
-rw-r--r--absl/flags/internal/flag.h25
-rw-r--r--absl/flags/internal/type_erased_test.cc7
-rw-r--r--absl/functional/bind_front.h26
-rw-r--r--absl/memory/memory_exception_safety_test.cc3
-rw-r--r--absl/strings/cord.cc8
-rw-r--r--absl/synchronization/internal/mutex_nonprod.inc4
-rw-r--r--absl/synchronization/internal/waiter.cc34
-rw-r--r--absl/synchronization/internal/waiter.h13
16 files changed, 130 insertions, 134 deletions
diff --git a/absl/base/exception_safety_testing_test.cc b/absl/base/exception_safety_testing_test.cc
index 575b535d..a59be29e 100644
--- a/absl/base/exception_safety_testing_test.cc
+++ b/absl/base/exception_safety_testing_test.cc
@@ -328,17 +328,15 @@ TEST(ThrowingValueTest, NonThrowingDelete) {
UnsetCountdown();
}
-using Storage =
- absl::aligned_storage_t<sizeof(ThrowingValue<>), alignof(ThrowingValue<>)>;
-
TEST(ThrowingValueTest, NonThrowingPlacementDelete) {
constexpr int kArrayLen = 2;
// We intentionally create extra space to store the tag allocated by placement
// new[].
constexpr int kStorageLen = 4;
- Storage buf;
- Storage array_buf[kStorageLen];
+ alignas(ThrowingValue<>) unsigned char buf[sizeof(ThrowingValue<>)];
+ alignas(ThrowingValue<>) unsigned char
+ array_buf[sizeof(ThrowingValue<>[kStorageLen])];
auto* placed = new (&buf) ThrowingValue<>(1);
auto placed_array = new (&array_buf) ThrowingValue<>[kArrayLen];
@@ -902,12 +900,12 @@ TEST(ConstructorTrackerTest, CreatedAfter) {
}
TEST(ConstructorTrackerTest, NotDestroyedAfter) {
- absl::aligned_storage_t<sizeof(Tracked), alignof(Tracked)> storage;
+ alignas(Tracked) unsigned char storage[sizeof(Tracked)];
EXPECT_NONFATAL_FAILURE(
{
exceptions_internal::ConstructorTracker ct(
exceptions_internal::countdown);
- new (&storage) Tracked;
+ new (&storage) Tracked();
},
"not destroyed");
}
@@ -924,11 +922,11 @@ TEST(ConstructorTrackerTest, DestroyedTwice) {
TEST(ConstructorTrackerTest, ConstructedTwice) {
exceptions_internal::ConstructorTracker ct(exceptions_internal::countdown);
- absl::aligned_storage_t<sizeof(Tracked), alignof(Tracked)> storage;
+ alignas(Tracked) unsigned char storage[sizeof(Tracked)];
EXPECT_NONFATAL_FAILURE(
{
- new (&storage) Tracked;
- new (&storage) Tracked;
+ new (&storage) Tracked();
+ new (&storage) Tracked();
reinterpret_cast<Tracked*>(&storage)->~Tracked();
},
"re-constructed");
diff --git a/absl/base/internal/low_level_alloc.cc b/absl/base/internal/low_level_alloc.cc
index 225abc24..1bf94438 100644
--- a/absl/base/internal/low_level_alloc.cc
+++ b/absl/base/internal/low_level_alloc.cc
@@ -220,16 +220,17 @@ struct LowLevelAlloc::Arena {
};
namespace {
-using ArenaStorage = std::aligned_storage<sizeof(LowLevelAlloc::Arena),
- alignof(LowLevelAlloc::Arena)>::type;
-
// Static storage space for the lazily-constructed, default global arena
// instances. We require this space because the whole point of LowLevelAlloc
// is to avoid relying on malloc/new.
-ArenaStorage default_arena_storage;
-ArenaStorage unhooked_arena_storage;
+alignas(LowLevelAlloc::Arena) unsigned char default_arena_storage[sizeof(
+ LowLevelAlloc::Arena)];
+alignas(LowLevelAlloc::Arena) unsigned char unhooked_arena_storage[sizeof(
+ LowLevelAlloc::Arena)];
#ifndef ABSL_LOW_LEVEL_ALLOC_ASYNC_SIGNAL_SAFE_MISSING
-ArenaStorage unhooked_async_sig_safe_arena_storage;
+alignas(
+ LowLevelAlloc::Arena) unsigned char unhooked_async_sig_safe_arena_storage
+ [sizeof(LowLevelAlloc::Arena)];
#endif
// We must use LowLevelCallOnce here to construct the global arenas, rather than
diff --git a/absl/base/options.h b/absl/base/options.h
index 6868c77b..234137c7 100644
--- a/absl/base/options.h
+++ b/absl/base/options.h
@@ -123,14 +123,6 @@
// compiler flags passed by the end user. For more info, see
// https://abseil.io/about/design/dropin-types.
-// A value of 2 means to detect the C++ version being used to compile Abseil,
-// and use an alias only if a working std::optional is available. This option
-// should not be used when your program is not built from source -- for example,
-// if you are distributing Abseil in a binary package manager -- since in mode
-// 2, absl::optional will name a different template class, with a different
-// mangled name and binary layout, depending on the compiler flags passed by the
-// end user.
-//
// User code should not inspect this macro. To check in the preprocessor if
// absl::optional is a typedef of std::optional, use the feature macro
// ABSL_USES_STD_OPTIONAL.
diff --git a/absl/container/fixed_array_test.cc b/absl/container/fixed_array_test.cc
index 2b1cf47e..c960fe51 100644
--- a/absl/container/fixed_array_test.cc
+++ b/absl/container/fixed_array_test.cc
@@ -604,19 +604,16 @@ TEST(FixedArrayTest, Fill) {
empty.fill(fill_val);
}
-// TODO(johnsoncj): Investigate InlinedStorage default initialization in GCC 4.x
#ifndef __GNUC__
TEST(FixedArrayTest, DefaultCtorDoesNotValueInit) {
using T = char;
constexpr auto capacity = 10;
using FixedArrType = absl::FixedArray<T, capacity>;
- using FixedArrBuffType =
- absl::aligned_storage_t<sizeof(FixedArrType), alignof(FixedArrType)>;
constexpr auto scrubbed_bits = 0x95;
constexpr auto length = capacity / 2;
- FixedArrBuffType buff;
- std::memset(std::addressof(buff), scrubbed_bits, sizeof(FixedArrBuffType));
+ alignas(FixedArrType) unsigned char buff[sizeof(FixedArrType)];
+ std::memset(std::addressof(buff), scrubbed_bits, sizeof(FixedArrType));
FixedArrType* arr =
::new (static_cast<void*>(std::addressof(buff))) FixedArrType(length);
diff --git a/absl/container/internal/common.h b/absl/container/internal/common.h
index 853a5b21..5037d803 100644
--- a/absl/container/internal/common.h
+++ b/absl/container/internal/common.h
@@ -56,7 +56,7 @@ class node_handle_base {
public:
using allocator_type = Alloc;
- constexpr node_handle_base() {}
+ constexpr node_handle_base() = default;
node_handle_base(node_handle_base&& other) noexcept {
*this = std::move(other);
}
@@ -109,9 +109,8 @@ class node_handle_base {
allocator_type* alloc() { return std::addressof(*alloc_); }
private:
- absl::optional<allocator_type> alloc_;
- mutable absl::aligned_storage_t<sizeof(slot_type), alignof(slot_type)>
- slot_space_;
+ absl::optional<allocator_type> alloc_ = {};
+ alignas(slot_type) mutable unsigned char slot_space_[sizeof(slot_type)] = {};
};
// For sets.
diff --git a/absl/container/internal/raw_hash_set.h b/absl/container/internal/raw_hash_set.h
index 0d3d604c..ca7be8d8 100644
--- a/absl/container/internal/raw_hash_set.h
+++ b/absl/container/internal/raw_hash_set.h
@@ -1067,8 +1067,7 @@ class raw_hash_set {
template <class... Args, typename std::enable_if<
!IsDecomposable<Args...>::value, int>::type = 0>
std::pair<iterator, bool> emplace(Args&&... args) {
- typename std::aligned_storage<sizeof(slot_type), alignof(slot_type)>::type
- raw;
+ alignas(slot_type) unsigned char raw[sizeof(slot_type)];
slot_type* slot = reinterpret_cast<slot_type*>(&raw);
PolicyTraits::construct(&alloc_ref(), slot, std::forward<Args>(args)...);
@@ -1556,8 +1555,7 @@ class raw_hash_set {
// mark target as FULL
// repeat procedure for current slot with moved from element (target)
ConvertDeletedToEmptyAndFullToDeleted(ctrl_, capacity_);
- typename std::aligned_storage<sizeof(slot_type), alignof(slot_type)>::type
- raw;
+ alignas(slot_type) unsigned char raw[sizeof(slot_type)];
size_t total_probe_length = 0;
slot_type* slot = reinterpret_cast<slot_type*>(&raw);
for (size_t i = 0; i != capacity_; ++i) {
diff --git a/absl/debugging/internal/stacktrace_x86-inl.inc b/absl/debugging/internal/stacktrace_x86-inl.inc
index f87cafb6..bc320ff7 100644
--- a/absl/debugging/internal/stacktrace_x86-inl.inc
+++ b/absl/debugging/internal/stacktrace_x86-inl.inc
@@ -202,9 +202,9 @@ static void **NextStackFrame(void **old_fp, const void *uc) {
} else {
num_push_instructions = 0;
}
-#else
+#else // ABSL_HAVE_VDSO_SUPPORT
num_push_instructions = 0;
-#endif
+#endif // ABSL_HAVE_VDSO_SUPPORT
}
if (num_push_instructions != 0 && kernel_rt_sigreturn_address != nullptr &&
old_fp[1] == kernel_rt_sigreturn_address) {
diff --git a/absl/flags/internal/flag.cc b/absl/flags/internal/flag.cc
index 83ec8df1..5a921e28 100644
--- a/absl/flags/internal/flag.cc
+++ b/absl/flags/internal/flag.cc
@@ -121,13 +121,21 @@ void FlagImpl::AssertValidType(FlagStaticTypeId type_id) const {
std::unique_ptr<void, DynValueDeleter> FlagImpl::MakeInitValue() const {
void* res = nullptr;
if (DefaultKind() == FlagDefaultKind::kDynamicValue) {
- res = flags_internal::Clone(op_, default_src_.dynamic_value);
+ res = flags_internal::Clone(op_, default_value_.dynamic_value);
} else {
- res = (*default_src_.gen_func)();
+ res = (*default_value_.gen_func)();
}
return {res, DynValueDeleter{op_}};
}
+void FlagImpl::StoreValue(const void* src) {
+ flags_internal::Copy(op_, src, value_.dynamic);
+ StoreAtomic();
+ modified_ = true;
+ ++counter_;
+ InvokeCallback();
+}
+
absl::string_view FlagImpl::Name() const { return name_; }
std::string FlagImpl::Filename() const {
@@ -220,23 +228,19 @@ bool FlagImpl::RestoreState(const void* value, bool modified,
// argument. If parsing successful, this function replaces the dst with newly
// parsed value. In case if any error is encountered in either step, the error
// message is stored in 'err'
-bool FlagImpl::TryParse(void** dst, absl::string_view value,
- std::string* err) const {
- auto tentative_value = MakeInitValue();
+std::unique_ptr<void, DynValueDeleter> FlagImpl::TryParse(
+ absl::string_view value, std::string* err) const {
+ std::unique_ptr<void, DynValueDeleter> tentative_value = MakeInitValue();
std::string parse_err;
if (!flags_internal::Parse(op_, value, tentative_value.get(), &parse_err)) {
absl::string_view err_sep = parse_err.empty() ? "" : "; ";
*err = absl::StrCat("Illegal value '", value, "' specified for flag '",
Name(), "'", err_sep, parse_err);
- return false;
+ return nullptr;
}
- void* old_val = *dst;
- *dst = tentative_value.release();
- tentative_value.reset(old_val);
-
- return true;
+ return tentative_value;
}
void FlagImpl::Read(void* dst) const {
@@ -266,22 +270,17 @@ void FlagImpl::Write(const void* src) {
absl::MutexLock l(DataGuard());
if (ShouldValidateFlagValue(flags_internal::StaticTypeId(op_))) {
- void* obj = flags_internal::Clone(op_, src);
+ std::unique_ptr<void, DynValueDeleter> obj{flags_internal::Clone(op_, src),
+ DynValueDeleter{op_}};
std::string ignored_error;
std::string src_as_str = flags_internal::Unparse(op_, src);
- if (!flags_internal::Parse(op_, src_as_str, obj, &ignored_error)) {
+ if (!flags_internal::Parse(op_, src_as_str, obj.get(), &ignored_error)) {
ABSL_INTERNAL_LOG(ERROR, absl::StrCat("Attempt to set flag '", Name(),
"' to invalid value ", src_as_str));
}
- flags_internal::Delete(op_, obj);
}
- modified_ = true;
- counter_++;
- flags_internal::Copy(op_, src, value_.dynamic);
-
- StoreAtomic();
- InvokeCallback();
+ StoreValue(src);
}
// Sets the value of the flag based on specified string `value`. If the flag
@@ -299,11 +298,10 @@ bool FlagImpl::SetFromString(absl::string_view value, FlagSettingMode set_mode,
switch (set_mode) {
case SET_FLAGS_VALUE: {
// set or modify the flag's value
- if (!TryParse(&value_.dynamic, value, err)) return false;
- modified_ = true;
- counter_++;
- StoreAtomic();
- InvokeCallback();
+ auto tentative_value = TryParse(value, err);
+ if (!tentative_value) return false;
+
+ StoreValue(tentative_value.get());
if (source == kCommandLine) {
on_command_line_ = true;
@@ -312,13 +310,7 @@ bool FlagImpl::SetFromString(absl::string_view value, FlagSettingMode set_mode,
}
case SET_FLAG_IF_DEFAULT: {
// set the flag's value, but only if it hasn't been set by someone else
- if (!modified_) {
- if (!TryParse(&value_.dynamic, value, err)) return false;
- modified_ = true;
- counter_++;
- StoreAtomic();
- InvokeCallback();
- } else {
+ if (modified_) {
// TODO(rogeeff): review and fix this semantic. Currently we do not fail
// in this case if flag is modified. This is misleading since the flag's
// value is not updated even though we return true.
@@ -327,28 +319,29 @@ bool FlagImpl::SetFromString(absl::string_view value, FlagSettingMode set_mode,
// return false;
return true;
}
+ auto tentative_value = TryParse(value, err);
+ if (!tentative_value) return false;
+
+ StoreValue(tentative_value.get());
break;
}
case SET_FLAGS_DEFAULT: {
+ auto tentative_value = TryParse(value, err);
+ if (!tentative_value) return false;
+
if (DefaultKind() == FlagDefaultKind::kDynamicValue) {
- if (!TryParse(&default_src_.dynamic_value, value, err)) {
- return false;
- }
+ void* old_value = default_value_.dynamic_value;
+ default_value_.dynamic_value = tentative_value.release();
+ tentative_value.reset(old_value);
} else {
- void* new_default_val = nullptr;
- if (!TryParse(&new_default_val, value, err)) {
- return false;
- }
-
- default_src_.dynamic_value = new_default_val;
+ default_value_.dynamic_value = tentative_value.release();
def_kind_ = static_cast<uint8_t>(FlagDefaultKind::kDynamicValue);
}
if (!modified_) {
// Need to set both default value *and* current, in this case
- flags_internal::Copy(op_, default_src_.dynamic_value, value_.dynamic);
- StoreAtomic();
- InvokeCallback();
+ StoreValue(default_value_.dynamic_value);
+ modified_ = false;
}
break;
}
diff --git a/absl/flags/internal/flag.h b/absl/flags/internal/flag.h
index ec673487..c1beda8e 100644
--- a/absl/flags/internal/flag.h
+++ b/absl/flags/internal/flag.h
@@ -363,7 +363,7 @@ struct DynValueDeleter {
if (op != nullptr) Delete(op, ptr);
}
- const FlagOpFn op;
+ FlagOpFn op;
};
class FlagImpl {
@@ -380,7 +380,7 @@ class FlagImpl {
on_command_line_(false),
counter_(0),
callback_(nullptr),
- default_src_(default_value_gen),
+ default_value_(default_value_gen),
data_guard_{} {}
// Constant access methods
@@ -392,10 +392,6 @@ class FlagImpl {
std::string DefaultValue() const ABSL_LOCKS_EXCLUDED(*DataGuard());
std::string CurrentValue() const ABSL_LOCKS_EXCLUDED(*DataGuard());
void Read(void* dst) const ABSL_LOCKS_EXCLUDED(*DataGuard());
- // Attempts to parse supplied `value` std::string. If parsing is successful, then
- // it replaces `dst` with the new value.
- bool TryParse(void** dst, absl::string_view value, std::string* err) const
- ABSL_EXCLUSIVE_LOCKS_REQUIRED(*DataGuard());
template <typename T, typename std::enable_if<
!IsAtomicFlagTypeTrait<T>::value, int>::type = 0>
@@ -466,8 +462,15 @@ class FlagImpl {
// Returns heap allocated value of type T initialized with default value.
std::unique_ptr<void, DynValueDeleter> MakeInitValue() const
ABSL_EXCLUSIVE_LOCKS_REQUIRED(*DataGuard());
- // Lazy initialization of the Flag's data.
+ // Flag initialization called via absl::call_once.
void Init();
+ // Attempts to parse supplied `value` std::string. If parsing is successful,
+ // returns new value. Otherwsie returns nullptr.
+ std::unique_ptr<void, DynValueDeleter> TryParse(absl::string_view value,
+ std::string* err) const
+ ABSL_EXCLUSIVE_LOCKS_REQUIRED(*DataGuard());
+ // Stores the flag value based on the pointer to the source.
+ void StoreValue(const void* src) ABSL_EXCLUSIVE_LOCKS_REQUIRED(*DataGuard());
FlagHelpKind HelpSourceKind() const {
return static_cast<FlagHelpKind>(help_source_kind_);
@@ -511,7 +514,7 @@ class FlagImpl {
// Mutable flag's state (guarded by `data_guard_`).
- // If def_kind_ == kDynamicValue, default_src_ holds a dynamically allocated
+ // If def_kind_ == kDynamicValue, default_value_ holds a dynamically allocated
// value.
uint8_t def_kind_ : 1 ABSL_GUARDED_BY(*DataGuard());
// Has this flag's value been modified?
@@ -527,7 +530,7 @@ class FlagImpl {
// value specified in ABSL_FLAG or pointer to the dynamically set default
// value via SetCommandLineOptionWithMode. def_kind_ is used to distinguish
// these two cases.
- FlagDefaultSrc default_src_ ABSL_GUARDED_BY(*DataGuard());
+ FlagDefaultSrc default_value_ ABSL_GUARDED_BY(*DataGuard());
// Current Flag Value
FlagValue value_;
@@ -542,8 +545,8 @@ class FlagImpl {
};
///////////////////////////////////////////////////////////////////////////////
-// The "unspecified" implementation of Flag object parameterized by the
-// flag's value type.
+// The Flag object parameterized by the flag's value type. This class implements
+// flag reflection handle interface.
template <typename T>
class Flag final : public flags_internal::CommandLineFlag {
diff --git a/absl/flags/internal/type_erased_test.cc b/absl/flags/internal/type_erased_test.cc
index 033e00e4..4ce59810 100644
--- a/absl/flags/internal/type_erased_test.cc
+++ b/absl/flags/internal/type_erased_test.cc
@@ -119,6 +119,13 @@ TEST_F(TypeErasedTest, TestSetCommandLineOptionWithMode_SET_FLAGS_DEFAULT) {
EXPECT_TRUE(flags::SetCommandLineOptionWithMode("int_flag", "101",
flags::SET_FLAGS_DEFAULT));
+ // Set it again to ensure that resetting logic is covered.
+ EXPECT_TRUE(flags::SetCommandLineOptionWithMode("int_flag", "102",
+ flags::SET_FLAGS_DEFAULT));
+
+ EXPECT_TRUE(flags::SetCommandLineOptionWithMode("int_flag", "103",
+ flags::SET_FLAGS_DEFAULT));
+
EXPECT_TRUE(flags::SetCommandLineOptionWithMode("string_flag", "asdfgh",
flags::SET_FLAGS_DEFAULT));
EXPECT_EQ(absl::GetFlag(FLAGS_string_flag), "asdfgh");
diff --git a/absl/functional/bind_front.h b/absl/functional/bind_front.h
index 8448d7b3..5b47970e 100644
--- a/absl/functional/bind_front.h
+++ b/absl/functional/bind_front.h
@@ -38,9 +38,7 @@ ABSL_NAMESPACE_BEGIN
// bind_front()
//
-// Binds the first N arguments of an invocable object and stores them by value,
-// except types of `std::reference_wrapper` which are 'unwound' and stored by
-// reference.
+// Binds the first N arguments of an invocable object and stores them by value.
//
// Like `std::bind()`, `absl::bind_front()` is implicitly convertible to
// `std::function`. In particular, it may be used as a simpler replacement for
@@ -140,7 +138,9 @@ ABSL_NAMESPACE_BEGIN
//
// Example: Storing bound arguments by reference.
//
-// void Print(const string& a, const string& b) { LOG(INFO) << a << b; }
+// void Print(const std::string& a, const std::string& b) {
+// std::cerr << a << b;
+// }
//
// std::string hi = "Hello, ";
// std::vector<std::string> names = {"Chuk", "Gek"};
@@ -152,6 +152,24 @@ ABSL_NAMESPACE_BEGIN
// // dangling references.
// foo->DoInFuture(absl::bind_front(Print, std::ref(hi), "Guest")); // BAD!
// auto f = absl::bind_front(Print, std::ref(hi), "Guest"); // BAD!
+//
+// Example: Storing reference-like types.
+//
+// void Print(absl::string_view a, const std::string& b) {
+// std::cerr << a << b;
+// }
+//
+// std::string hi = "Hello, ";
+// // Copies "hi".
+// absl::bind_front(Print, hi)("Chuk");
+//
+// // Compile error: std::reference_wrapper<const string> is not implicitly
+// // convertible to string_view.
+// // absl::bind_front(Print, std::cref(hi))("Chuk");
+//
+// // Doesn't copy "hi".
+// absl::bind_front(Print, absl::string_view(hi))("Chuk");
+//
template <class F, class... BoundArgs>
constexpr functional_internal::bind_front_t<F, BoundArgs...> bind_front(
F&& func, BoundArgs&&... args) {
diff --git a/absl/memory/memory_exception_safety_test.cc b/absl/memory/memory_exception_safety_test.cc
index c0910dc7..1df72614 100644
--- a/absl/memory/memory_exception_safety_test.cc
+++ b/absl/memory/memory_exception_safety_test.cc
@@ -27,9 +27,6 @@ namespace {
constexpr int kLength = 50;
using Thrower = testing::ThrowingValue<testing::TypeSpec::kEverythingThrows>;
-using ThrowerStorage =
- absl::aligned_storage_t<sizeof(Thrower), alignof(Thrower)>;
-using ThrowerList = std::array<ThrowerStorage, kLength>;
TEST(MakeUnique, CheckForLeaks) {
constexpr int kValue = 321;
diff --git a/absl/strings/cord.cc b/absl/strings/cord.cc
index cc0cc9d7..d9503ae3 100644
--- a/absl/strings/cord.cc
+++ b/absl/strings/cord.cc
@@ -63,16 +63,16 @@ namespace {
// Type used with std::allocator for allocating and deallocating
// `CordRepExternal`. std::allocator is used because it opaquely handles the
// different new / delete overloads available on a given platform.
-using ExternalAllocType =
- absl::aligned_storage_t<absl::cord_internal::ExternalRepAlignment(),
- absl::cord_internal::ExternalRepAlignment()>;
+struct alignas(absl::cord_internal::ExternalRepAlignment()) ExternalAllocType {
+ unsigned char value[absl::cord_internal::ExternalRepAlignment()];
+};
// Returns the number of objects to pass in to std::allocator<ExternalAllocType>
// allocate() and deallocate() to create enough room for `CordRepExternal` with
// `releaser_size` bytes on the end.
constexpr size_t GetExternalAllocNumObjects(size_t releaser_size) {
// Be sure to round up since `releaser_size` could be smaller than
- // sizeof(ExternalAllocType)`.
+ // `sizeof(ExternalAllocType)`.
return (sizeof(CordRepExternal) + releaser_size + sizeof(ExternalAllocType) -
1) /
sizeof(ExternalAllocType);
diff --git a/absl/synchronization/internal/mutex_nonprod.inc b/absl/synchronization/internal/mutex_nonprod.inc
index 85dae0ff..a1502e72 100644
--- a/absl/synchronization/internal/mutex_nonprod.inc
+++ b/absl/synchronization/internal/mutex_nonprod.inc
@@ -252,8 +252,8 @@ class SynchronizationStorage {
absl::once_flag once_;
- // An aligned space for T.
- typename std::aligned_storage<sizeof(T), alignof(T)>::type space_;
+ // An aligned space for the T.
+ alignas(T) unsigned char space_[sizeof(T)];
};
} // namespace synchronization_internal
diff --git a/absl/synchronization/internal/waiter.cc b/absl/synchronization/internal/waiter.cc
index ddd6081e..2949f5a8 100644
--- a/absl/synchronization/internal/waiter.cc
+++ b/absl/synchronization/internal/waiter.cc
@@ -368,31 +368,29 @@ class Waiter::WinHelper {
return reinterpret_cast<CONDITION_VARIABLE *>(&w->cv_storage_);
}
- static_assert(sizeof(SRWLOCK) == sizeof(Waiter::SRWLockStorage),
- "SRWLockStorage does not have the same size as SRWLOCK");
+ static_assert(sizeof(SRWLOCK) == sizeof(void *),
+ "`mu_storage_` does not have the same size as SRWLOCK");
+ static_assert(alignof(SRWLOCK) == alignof(void *),
+ "`mu_storage_` does not have the same alignment as SRWLOCK");
+
+ static_assert(sizeof(CONDITION_VARIABLE) == sizeof(void *),
+ "`ABSL_CONDITION_VARIABLE_STORAGE` does not have the same size "
+ "as `CONDITION_VARIABLE`");
static_assert(
- alignof(SRWLOCK) == alignof(Waiter::SRWLockStorage),
- "SRWLockStorage does not have the same alignment as SRWLOCK");
-
- static_assert(sizeof(CONDITION_VARIABLE) ==
- sizeof(Waiter::ConditionVariableStorage),
- "ABSL_CONDITION_VARIABLE_STORAGE does not have the same size "
- "as CONDITION_VARIABLE");
- static_assert(alignof(CONDITION_VARIABLE) ==
- alignof(Waiter::ConditionVariableStorage),
- "ConditionVariableStorage does not have the same "
- "alignment as CONDITION_VARIABLE");
+ alignof(CONDITION_VARIABLE) == alignof(void *),
+ "`cv_storage_` does not have the same alignment as `CONDITION_VARIABLE`");
// The SRWLOCK and CONDITION_VARIABLE types must be trivially constructible
// and destructible because we never call their constructors or destructors.
static_assert(std::is_trivially_constructible<SRWLOCK>::value,
- "The SRWLOCK type must be trivially constructible");
- static_assert(std::is_trivially_constructible<CONDITION_VARIABLE>::value,
- "The CONDITION_VARIABLE type must be trivially constructible");
+ "The `SRWLOCK` type must be trivially constructible");
+ static_assert(
+ std::is_trivially_constructible<CONDITION_VARIABLE>::value,
+ "The `CONDITION_VARIABLE` type must be trivially constructible");
static_assert(std::is_trivially_destructible<SRWLOCK>::value,
- "The SRWLOCK type must be trivially destructible");
+ "The `SRWLOCK` type must be trivially destructible");
static_assert(std::is_trivially_destructible<CONDITION_VARIABLE>::value,
- "The CONDITION_VARIABLE type must be trivially destructible");
+ "The `CONDITION_VARIABLE` type must be trivially destructible");
};
class LockHolder {
diff --git a/absl/synchronization/internal/waiter.h b/absl/synchronization/internal/waiter.h
index 5af5c282..a6e6d4c7 100644
--- a/absl/synchronization/internal/waiter.h
+++ b/absl/synchronization/internal/waiter.h
@@ -133,13 +133,6 @@ class Waiter {
std::atomic<int> wakeups_;
#elif ABSL_WAITER_MODE == ABSL_WAITER_MODE_WIN32
- // We can't include Windows.h in our headers, so we use aligned storage
- // buffers to define the storage of SRWLOCK and CONDITION_VARIABLE.
- using SRWLockStorage =
- typename std::aligned_storage<sizeof(void*), alignof(void*)>::type;
- using ConditionVariableStorage =
- typename std::aligned_storage<sizeof(void*), alignof(void*)>::type;
-
// WinHelper - Used to define utilities for accessing the lock and
// condition variable storage once the types are complete.
class WinHelper;
@@ -147,8 +140,10 @@ class Waiter {
// REQUIRES: WinHelper::GetLock(this) must be held.
void InternalCondVarPoke();
- SRWLockStorage mu_storage_;
- ConditionVariableStorage cv_storage_;
+ // We can't include Windows.h in our headers, so we use aligned charachter
+ // buffers to define the storage of SRWLOCK and CONDITION_VARIABLE.
+ alignas(void*) unsigned char mu_storage_[sizeof(void*)];
+ alignas(void*) unsigned char cv_storage_[sizeof(void*)];
int waiter_count_;
int wakeup_count_;