Add 'third_party/abseil_cpp/' from commit '768eb2ca28'

git-subtree-dir: third_party/abseil_cpp
git-subtree-mainline: ffb2ae54be
git-subtree-split: 768eb2ca28

third_party/abseil_cpp/absl/flags/internal/program_name.cc

@@ -0,0 +1,60 @@
+//
+//  Copyright 2019 The Abseil Authors.
+//
+// Licensed 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
+//
+//      https://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.
+
+#include "absl/flags/internal/program_name.h"
+
+#include <string>
+
+#include "absl/base/attributes.h"
+#include "absl/base/config.h"
+#include "absl/base/const_init.h"
+#include "absl/base/thread_annotations.h"
+#include "absl/flags/internal/path_util.h"
+#include "absl/strings/string_view.h"
+#include "absl/synchronization/mutex.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace flags_internal {
+
+ABSL_CONST_INIT static absl::Mutex program_name_guard(absl::kConstInit);
+ABSL_CONST_INIT static std::string* program_name
+    ABSL_GUARDED_BY(program_name_guard) = nullptr;
+
+std::string ProgramInvocationName() {
+  absl::MutexLock l(&program_name_guard);
+
+  return program_name ? *program_name : "UNKNOWN";
+}
+
+std::string ShortProgramInvocationName() {
+  absl::MutexLock l(&program_name_guard);
+
+  return program_name ? std::string(flags_internal::Basename(*program_name))
+                      : "UNKNOWN";
+}
+
+void SetProgramInvocationName(absl::string_view prog_name_str) {
+  absl::MutexLock l(&program_name_guard);
+
+  if (!program_name)
+    program_name = new std::string(prog_name_str);
+  else
+    program_name->assign(prog_name_str.data(), prog_name_str.size());
+}
+
+}  // namespace flags_internal
+ABSL_NAMESPACE_END
+}  // namespace absl