Export of internal Abseil changes

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693f81830b9f9cc8b24a1f38492b8dfcdd1d0e24 by Abseil Team <absl-team@google.com>:

Check that absl::int128 works as a std::chrono::duration::rep.

In particular, validate that ...
  std::chrono::time_point<std::chrono::system_clock,
                          std::chrono::duration<absl::int128,
                                                std::atto>>
is a superset (range and resolution) of absl::Time.

PiperOrigin-RevId: 283370280

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df6073b686bd44223c6f9070fcceec918c728871 by Gennadiy Rozental <rogeeff@google.com>:

Changes thread annotations to use DataGuard() function instead of a specific Mutex.
Remove unused declaration of InvokeCallback.

PiperOrigin-RevId: 283361188

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b49eb2dd2ee1a0b4c8a7bb1a94e368b81ce5f861 by Abseil Team <absl-team@google.com>:

Rewrite GetNominalCPUFrequency to use advapi32 instead of shlwapi

Using shlwapi.dll means that gdi32.dll is loaded which then makes process destruction more expensive, which is unacceptable for some uses. There may be other places that pull in gdi32.dll - this just fixes the one.

PiperOrigin-RevId: 282960698

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b5508afec5099a0fdbb55e39a7cd2993259ed860 by Abseil Team <absl-team@google.com>:

Small typo fix in comments: initiazliation -> initialization

PiperOrigin-RevId: 282891800

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4319cc419584e91ee74f6ae1a32d88a412fc5c01 by Abseil Team <absl-team@google.com>:

Update c_find_first_of() comment to remove the mention of an ordered container.

PiperOrigin-RevId: 282836540

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5fcabc0a834dff39a505d5a5fc5403ddeb96028e by Derek Mauro <dmauro@google.com>:

Fix NaCl build, where format checking is broken

PiperOrigin-RevId: 282826202

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aaf9ad3274c056a2f68e9b8ccada45c9802e2f1e by Derek Mauro <dmauro@google.com>:

Fix more -Wundef warnings

PiperOrigin-RevId: 282799820

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1fb06150a70ffe98bf4b2d42b2a39d083bf44f8c by Derek Mauro <dmauro@google.com>:

Release support for additional platforms

PiperOrigin-RevId: 282793384

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fa947fc28624a316fa872d7045b3838b88a0d69b by Derek Mauro <dmauro@google.com>:

Cleanup inconsistent usage of __has_attribute

PiperOrigin-RevId: 282793296

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990030ad282263d6303c83b780a55fdec8e90d43 by Gennadiy Rozental <rogeeff@google.com>:

Eliminate the pointer in absl::Flag, which points to n space where we were storing flag's default value. We also eliminate additional (now unnecessary) allocation for flag's default value.
Instead we'll initialize the flags value directly from the value specified in ABSL_FLAG.
If the default value is updated via the call to SetCommandLineOptionWithMode we are replacing pointer to initialization routine to pointer to new default value.

PiperOrigin-RevId: 282637616
GitOrigin-RevId: 693f81830b9f9cc8b24a1f38492b8dfcdd1d0e24
Change-Id: I6f2edd8ef844de09aa2c182a7ca3133a22364792

1 files changed, 42 insertions, 29 deletions

diff --git a/absl/flags/internal/flag.cc b/absl/flags/internal/flag.cc
index d087f79e..435cc362 100644
--- a/absl/flags/internal/flag.cc
+++ b/absl/flags/internal/flag.cc
@@ -49,12 +49,11 @@ void FlagImpl::Init() {
 
   absl::MutexLock lock(&locks_->primary_mu);
 
-  if (def_ != nullptr) {
+  if (cur_ != nullptr) {
     inited_.store(true, std::memory_order_release);
   } else {
-    // Need to initialize def and cur fields.
-    def_ = (*initial_value_gen_)();
-    cur_ = Clone(op_, def_);
+    // Need to initialize cur field.
+    cur_ = MakeInitValue().release();
     StoreAtomic();
     inited_.store(true, std::memory_order_release);
     InvokeCallback();
@@ -63,8 +62,7 @@ void FlagImpl::Init() {
 
 // Ensures that the lazily initialized data is initialized,
 // and returns pointer to the mutex guarding flags data.
-absl::Mutex* FlagImpl::DataGuard() const
-    ABSL_LOCK_RETURNED(locks_->primary_mu) {
+absl::Mutex* FlagImpl::DataGuard() const {
   if (ABSL_PREDICT_FALSE(!inited_.load(std::memory_order_acquire))) {
     const_cast<FlagImpl*>(this)->Init();
   }
@@ -79,12 +77,23 @@ void FlagImpl::Destroy() const {
 
     // Values are heap allocated for Abseil Flags.
     if (cur_) Delete(op_, cur_);
-    if (def_) Delete(op_, def_);
+    if (def_kind_ == FlagDefaultSrcKind::kDynamicValue)
+      Delete(op_, default_src_.dynamic_value);
   }
 
   delete locks_;
 }
 
+std::unique_ptr<void, DynValueDeleter> FlagImpl::MakeInitValue() const {
+  void* res = nullptr;
+  if (def_kind_ == FlagDefaultSrcKind::kDynamicValue) {
+    res = Clone(op_, default_src_.dynamic_value);
+  } else {
+    res = (*default_src_.gen_func)();
+  }
+  return {res, DynValueDeleter{op_}};
+}
+
 std::string FlagImpl::Help() const {
   return help_source_kind_ == FlagHelpSrcKind::kLiteral ? help_.literal
                                                         : help_.gen_func();
@@ -103,7 +112,8 @@ bool FlagImpl::IsSpecifiedOnCommandLine() const {
 std::string FlagImpl::DefaultValue() const {
   absl::MutexLock l(DataGuard());
 
-  return Unparse(marshalling_op_, def_);
+  auto obj = MakeInitValue();
+  return Unparse(marshalling_op_, obj.get());
 }
 
 std::string FlagImpl::CurrentValue() const {
@@ -121,8 +131,7 @@ void FlagImpl::SetCallback(
   InvokeCallback();
 }
 
-void FlagImpl::InvokeCallback() const
-    ABSL_EXCLUSIVE_LOCKS_REQUIRED(locks_->primary_mu) {
+void FlagImpl::InvokeCallback() const {
   if (!callback_) return;
 
   // If the flag has a mutation callback this function invokes it. While the
@@ -172,23 +181,20 @@ bool FlagImpl::RestoreState(const CommandLineFlag& flag, const void* value,
 // 'dst' assuming it is a pointer to the flag's value type. In case if any error
 // is encountered in either step, the error message is stored in 'err'
 bool FlagImpl::TryParse(const CommandLineFlag& flag, void* dst,
-                        absl::string_view value, std::string* err) const
-    ABSL_EXCLUSIVE_LOCKS_REQUIRED(locks_->primary_mu) {
-  void* tentative_value = Clone(op_, def_);
+                        absl::string_view value, std::string* err) const {
+  auto tentative_value = MakeInitValue();
   std::string parse_err;
-  if (!Parse(marshalling_op_, value, tentative_value, &parse_err)) {
+  if (!Parse(marshalling_op_, value, tentative_value.get(), &parse_err)) {
     auto type_name = flag.Typename();
     absl::string_view err_sep = parse_err.empty() ? "" : "; ";
     absl::string_view typename_sep = type_name.empty() ? "" : " ";
     *err = absl::StrCat("Illegal value '", value, "' specified for",
                         typename_sep, type_name, " flag '", flag.Name(), "'",
                         err_sep, parse_err);
-    Delete(op_, tentative_value);
     return false;
   }
 
-  Copy(op_, tentative_value, dst);
-  Delete(op_, tentative_value);
+  Copy(op_, tentative_value.get(), dst);
   return true;
 }
 
@@ -208,7 +214,7 @@ void FlagImpl::Read(const CommandLineFlag& flag, void* dst,
   CopyConstruct(op_, cur_, dst);
 }
 
-void FlagImpl::StoreAtomic() ABSL_EXCLUSIVE_LOCKS_REQUIRED(locks_->primary_mu) {
+void FlagImpl::StoreAtomic() {
   size_t data_size = Sizeof(op_);
 
   if (data_size <= sizeof(int64_t)) {
@@ -299,12 +305,22 @@ bool FlagImpl::SetFromString(const CommandLineFlag& flag,
       break;
     }
     case SET_FLAGS_DEFAULT: {
-      // modify the flag's default-value
-      if (!TryParse(flag, def_, value, err)) return false;
+      // Flag's new default-value.
+      auto new_default_value = MakeInitValue();
+
+      if (!TryParse(flag, new_default_value.get(), value, err)) return false;
+
+      if (def_kind_ == FlagDefaultSrcKind::kDynamicValue) {
+        // Release old default value.
+        Delete(op_, default_src_.dynamic_value);
+      }
+
+      default_src_.dynamic_value = new_default_value.release();
+      def_kind_ = FlagDefaultSrcKind::kDynamicValue;
 
       if (!modified_) {
         // Need to set both default value *and* current, in this case
-        Copy(op_, def_, cur_);
+        Copy(op_, default_src_.dynamic_value, cur_);
         StoreAtomic();
         InvokeCallback();
       }
@@ -321,9 +337,9 @@ void FlagImpl::CheckDefaultValueParsingRoundtrip(
 
   absl::MutexLock lock(DataGuard());
 
-  void* dst = Clone(op_, def_);
+  auto dst = MakeInitValue();
   std::string error;
-  if (!flags_internal::Parse(marshalling_op_, v, dst, &error)) {
+  if (!flags_internal::Parse(marshalling_op_, v, dst.get(), &error)) {
     ABSL_INTERNAL_LOG(
         FATAL,
         absl::StrCat("Flag ", flag.Name(), " (from ", flag.Filename(),
@@ -333,18 +349,15 @@ void FlagImpl::CheckDefaultValueParsingRoundtrip(
 
   // We do not compare dst to def since parsing/unparsing may make
   // small changes, e.g., precision loss for floating point types.
-  Delete(op_, dst);
 }
 
 bool FlagImpl::ValidateInputValue(absl::string_view value) const {
   absl::MutexLock l(DataGuard());
 
-  void* obj = Clone(op_, def_);
+  auto obj = MakeInitValue();
   std::string ignored_error;
-  const bool result =
-      flags_internal::Parse(marshalling_op_, value, obj, &ignored_error);
-  Delete(op_, obj);
-  return result;
+  return flags_internal::Parse(marshalling_op_, value, obj.get(),
+                               &ignored_error);
 }
 
 }  // namespace flags_internal