Internal change that helps identify the origin of reflection calls.

PiperOrigin-RevId: 510255963

pkg/BUILD.bazel

@@ -362,6 +362,7 @@ cc_dist_library(
         "//src/google/protobuf:arena_align",
         "//src/google/protobuf:protobuf_nowkt",
         "//src/google/protobuf:wkt_cc_proto",
+        "//src/google/protobuf:reflection_mode",
         "//src/google/protobuf/compiler:importer",
         "//src/google/protobuf/json",
         "//src/google/protobuf/util:delimited_message_util",

src/google/protobuf/BUILD.bazel

@@ -1314,6 +1314,31 @@ cc_test(
     ],
 )
 
+cc_library(
+    name = "reflection_mode",
+    srcs = ["reflection_mode.cc"],
+    hdrs = ["reflection_mode.h"],
+    include_prefix = "google/protobuf",
+    visibility = [
+        "//:__subpackages__",
+        "//src/google/protobuf:__subpackages__",
+    ],
+    deps = [
+        ":port_def",
+        ":protobuf",
+    ],
+)
+
+cc_test(
+    name = "reflection_mode_test",
+    srcs = ["reflection_mode_test.cc"],
+    deps = [
+        ":reflection_mode",
+        "@com_google_googletest//:gtest",
+        "@com_google_googletest//:gtest_main",
+    ],
+)
+
 ################################################################################
 # Helper targets for Kotlin tests
 ################################################################################

src/google/protobuf/reflection_mode.cc

@@ -0,0 +1,57 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2023 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "google/protobuf/reflection_mode.h"
+
+// Must be included last.
+#include "google/protobuf/port_def.inc"
+
+namespace google {
+namespace protobuf {
+namespace internal {
+
+#if !defined(PROTOBUF_NO_THREADLOCAL)
+
+#if defined(PROTOBUF_USE_DLLS)
+ReflectionMode& ScopedReflectionMode::reflection_mode() {
+  static PROTOBUF_THREAD_LOCAL ReflectionMode reflection_mode =
+      ReflectionMode::kDefault;
+  return reflection_mode;
+}
+#else
+PROTOBUF_CONSTINIT PROTOBUF_THREAD_LOCAL ReflectionMode
+    ScopedReflectionMode::reflection_mode_ = ReflectionMode::kDefault;
+#endif
+
+#endif
+
+}  // namespace internal
+}  // namespace protobuf
+}  // namespace google

src/google/protobuf/reflection_mode.h

@@ -0,0 +1,165 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2023 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// This header provides support for a per thread 'reflection mode'.
+//
+// Some protocol buffer optimizations use interceptors to determine which
+// fields are effectively used in the application. These optimizations are
+// disabled if certain reflection calls are intercepted as the assumption is
+// then that any field data can be accessed.
+//
+// The 'reflection mode' defined in this header is intended to be used by
+// logic such as ad-hoc profilers to indicate that any scoped reflection usage
+// is not originating from, or affecting application code. This reflection mode
+// can then be used by such interceptors to ignore any reflection calls not
+// affecting the application behavior.
+
+#ifndef GOOGLE_PROTOBUF_REFLECTION_MODE_H__
+#define GOOGLE_PROTOBUF_REFLECTION_MODE_H__
+
+#include <cstddef>
+
+// Must be included last.
+#include "google/protobuf/port_def.inc"
+
+namespace google {
+namespace protobuf {
+namespace internal {
+
+// The ReflectionModes are ordered in observability levels:
+// kDefault: Lowest level. All reflection calls are observable.
+// kDebugString: Middle level. Only reflection calls in Message::DebugString are
+//               observable.
+// kDiagnostics: Highest level. No reflection calls are observable.
+enum class ReflectionMode {
+  kDefault,
+  kDebugString,
+  kDiagnostics,
+};
+
+// Returns the current ReflectionMode of protobuf for the current thread. This
+// reflection mode can be used by interceptors to ignore any reflection calls
+// not affecting the application behavior.
+// Always returns `kDefault' if the current platform does not support thread
+// local data.
+ReflectionMode GetReflectionMode();
+
+// Scoping class to set the specific ReflectionMode for a given scope.
+class PROTOBUF_EXPORT ScopedReflectionMode final {
+ public:
+  // Sets the current reflection mode, which will be restored at destruction.
+  // The reflection mode can only be 'elevated' in observability levels.
+  // For instance, if the current mode is `kDiagnostics` then scope will remain
+  // unchanged regardless of `mode`.
+  explicit ScopedReflectionMode(ReflectionMode mode);
+
+  // Restores the previous reflection mode.
+  ~ScopedReflectionMode();
+
+  // Returns the scoped ReflectionMode for the current thread.
+  // See `GetReflectionMode()` for more information on purpose and usage.
+  static ReflectionMode current_reflection_mode();
+
+  // ScopedReflectionMode is only intended to be used as a locally scoped
+  // instance to set a reflection mode for the code scoped by this instance.
+  ScopedReflectionMode(const ScopedReflectionMode&) = delete;
+  ScopedReflectionMode& operator=(const ScopedReflectionMode&) = delete;
+
+ private:
+#if !defined(PROTOBUF_NO_THREADLOCAL)
+  const ReflectionMode previous_mode_;
+#if defined(PROTOBUF_USE_DLLS)
+  static ReflectionMode& reflection_mode();
+#else
+  PROTOBUF_CONSTINIT static PROTOBUF_THREAD_LOCAL ReflectionMode
+      reflection_mode_;
+#endif  // PROTOBUF_USE_DLLS
+#endif  // !PROTOBUF_NO_THREADLOCAL
+};
+
+#if !defined(PROTOBUF_NO_THREADLOCAL)
+
+#if defined(PROTOBUF_USE_DLLS)
+
+inline ScopedReflectionMode::ScopedReflectionMode(ReflectionMode mode)
+    : previous_mode_(reflection_mode()) {
+  if (mode > reflection_mode()) {
+    reflection_mode() = mode;
+  }
+}
+
+inline ScopedReflectionMode::~ScopedReflectionMode() {
+  reflection_mode() = previous_mode_;
+}
+
+inline ReflectionMode ScopedReflectionMode::current_reflection_mode() {
+  return reflection_mode();
+}
+
+#else
+
+inline ScopedReflectionMode::ScopedReflectionMode(ReflectionMode mode)
+    : previous_mode_(reflection_mode_) {
+  if (mode > reflection_mode_) {
+    reflection_mode_ = mode;
+  }
+}
+
+inline ScopedReflectionMode::~ScopedReflectionMode() {
+  reflection_mode_ = previous_mode_;
+}
+
+inline ReflectionMode ScopedReflectionMode::current_reflection_mode() {
+  return reflection_mode_;
+}
+
+#endif  // PROTOBUF_USE_DLLS
+
+#else
+
+inline ScopedReflectionMode::ScopedReflectionMode(ReflectionMode mode) {}
+inline ScopedReflectionMode::~ScopedReflectionMode() {}
+inline ReflectionMode ScopedReflectionMode::current_reflection_mode() {
+  return ReflectionMode::kDefault;
+}
+
+#endif  // !PROTOBUF_NO_THREADLOCAL
+
+inline ReflectionMode GetReflectionMode() {
+  return ScopedReflectionMode::current_reflection_mode();
+}
+
+}  // namespace internal
+}  // namespace protobuf
+}  // namespace google
+
+#include "google/protobuf/port_undef.inc"
+
+#endif  // GOOGLE_PROTOBUF_REFLECTION_MODE_H__

src/google/protobuf/reflection_mode_test.cc

@@ -0,0 +1,115 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2023 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#include "google/protobuf/reflection_mode.h"
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+namespace google {
+namespace protobuf {
+namespace internal {
+
+#ifndef PROTOBUF_NO_THREADLOCAL
+
+TEST(ReflectionModeTest, SimpleScopedReflection) {
+  ASSERT_EQ(ScopedReflectionMode::current_reflection_mode(),
+            ReflectionMode::kDefault);
+  ScopedReflectionMode scope(ReflectionMode::kDiagnostics);
+  EXPECT_EQ(ScopedReflectionMode::current_reflection_mode(),
+            ReflectionMode::kDiagnostics);
+}
+
+TEST(ReflectionModeTest, CleanNestedScopedReflection) {
+  ASSERT_EQ(ScopedReflectionMode::current_reflection_mode(),
+            ReflectionMode::kDefault);
+  {
+    ScopedReflectionMode scope1(ReflectionMode::kDebugString);
+    EXPECT_EQ(ScopedReflectionMode::current_reflection_mode(),
+              ReflectionMode::kDebugString);
+    {
+      ScopedReflectionMode scope2(ReflectionMode::kDiagnostics);
+      EXPECT_EQ(ScopedReflectionMode::current_reflection_mode(),
+                ReflectionMode::kDiagnostics);
+    }
+    EXPECT_EQ(ScopedReflectionMode::current_reflection_mode(),
+              ReflectionMode::kDebugString);
+  }
+  EXPECT_EQ(ScopedReflectionMode::current_reflection_mode(),
+            ReflectionMode::kDefault);
+}
+
+TEST(ReflectionModeTest, UglyNestedScopedReflection) {
+  ASSERT_EQ(ScopedReflectionMode::current_reflection_mode(),
+            ReflectionMode::kDefault);
+  ScopedReflectionMode scope1(ReflectionMode::kDebugString);
+  EXPECT_EQ(ScopedReflectionMode::current_reflection_mode(),
+            ReflectionMode::kDebugString);
+  ScopedReflectionMode scope2(ReflectionMode::kDiagnostics);
+  EXPECT_EQ(ScopedReflectionMode::current_reflection_mode(),
+            ReflectionMode::kDiagnostics);
+}
+
+TEST(ReflectionModeTest, DebugStringModeDoesNotReplaceDiagnosticsMode) {
+  ASSERT_EQ(ScopedReflectionMode::current_reflection_mode(),
+            ReflectionMode::kDefault);
+  ScopedReflectionMode scope1(ReflectionMode::kDiagnostics);
+  {
+    ScopedReflectionMode scope2(ReflectionMode::kDebugString);
+    EXPECT_EQ(ScopedReflectionMode::current_reflection_mode(),
+              ReflectionMode::kDiagnostics);
+  }
+}
+
+#else
+
+TEST(ReflectionModeTest, AlwaysReturnDefaultWhenNoThreadLocal) {
+  ASSERT_EQ(ScopedReflectionMode::current_reflection_mode(),
+            ReflectionMode::kDefault);
+  {
+    ScopedReflectionMode scope1(ReflectionMode::kDebugString);
+    EXPECT_EQ(ScopedReflectionMode::current_reflection_mode(),
+              ReflectionMode::kDefault);
+    {
+      ScopedReflectionMode scope2(ReflectionMode::kDiagnostics);
+      EXPECT_EQ(ScopedReflectionMode::current_reflection_mode(),
+                ReflectionMode::kDefault);
+    }
+    EXPECT_EQ(ScopedReflectionMode::current_reflection_mode(),
+              ReflectionMode::kDefault);
+  }
+  EXPECT_EQ(ScopedReflectionMode::current_reflection_mode(),
+            ReflectionMode::kDefault);
+}
+
+#endif
+
+}  // namespace internal
+}  // namespace protobuf
+}  // namespace google