[lldb][telemetry] Implement LLDB Telemetry (part 1) (#119716)

Details:
- This is a subset of PR/98528.( Pavel's suggestion was to split up the
patch to make reviewing easier)
- This contains only the concrete implementation of the framework to be
used but no usages yet.
- I plan to send a few follow-up patches:
+ part2 : includes changes in the plugin-manager to set up the plugin
stuff (ie., how to create a default vs vendor impl)
  + part3 (all of the following can be done in parallel):
* part 3_a: define DebuggerTelemetryInfo and related methods to collect
data about debugger startup/exit
* part 3_b: define TargetTelemetryInfo and related methods to collect
data about debug target(s)
* part 3_c: define CommandTelemetryInfo and related methods to collect
data about debug-commands
* part 3_d: define ClientTelemtryInfo and related methods to collect
data about lldb-dap/any other client

---------

Co-authored-by: Pavel Labath <[email protected]>
Co-authored-by: Jonas Devlieghere <[email protected]>

Author: 3 people

lldb/include/lldb/Core/Telemetry.h

@@ -0,0 +1,74 @@
+//===-- Telemetry.h -------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_CORE_TELEMETRY_H
+#define LLDB_CORE_TELEMETRY_H
+
+#include "lldb/Core/StructuredDataImpl.h"
+#include "lldb/Interpreter/CommandReturnObject.h"
+#include "lldb/Utility/StructuredData.h"
+#include "lldb/lldb-forward.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/JSON.h"
+#include "llvm/Telemetry/Telemetry.h"
+#include <chrono>
+#include <ctime>
+#include <memory>
+#include <optional>
+#include <string>
+#include <unordered_map>
+
+namespace lldb_private {
+namespace telemetry {
+
+struct LLDBEntryKind : public ::llvm::telemetry::EntryKind {
+  static const llvm::telemetry::KindType BaseInfo = 0b11000;
+};
+
+/// Defines a convenient type for timestamp of various events.
+using SteadyTimePoint = std::chrono::time_point<std::chrono::steady_clock,
+                                                std::chrono::nanoseconds>;
+struct LLDBBaseTelemetryInfo : public llvm::telemetry::TelemetryInfo {
+  /// Start time of an event
+  SteadyTimePoint start_time;
+  /// End time of an event - may be empty if not meaningful.
+  std::optional<SteadyTimePoint> end_time;
+  // TBD: could add some memory stats here too?
+
+  Debugger *debugger;
+
+  // For dyn_cast, isa, etc operations.
+  llvm::telemetry::KindType getKind() const override {
+    return LLDBEntryKind::BaseInfo;
+  }
+
+  static bool classof(const llvm::telemetry::TelemetryInfo *t) {
+    // Subclasses of this is also acceptable.
+    return (t->getKind() & LLDBEntryKind::BaseInfo) == LLDBEntryKind::BaseInfo;
+  }
+
+  void serialize(llvm::telemetry::Serializer &serializer) const override;
+};
+
+/// The base Telemetry manager instance in LLDB
+/// This class declares additional instrumentation points
+/// applicable to LLDB.
+class TelemetryManager : public llvm::telemetry::Manager {
+public:
+  TelemetryManager(std::unique_ptr<llvm::telemetry::Config> config);
+
+  llvm::Error preDispatch(llvm::telemetry::TelemetryInfo *entry) override;
+
+private:
+  std::unique_ptr<llvm::telemetry::Config> m_config;
+};
+
+} // namespace telemetry
+} // namespace lldb_private
+#endif // LLDB_CORE_TELEMETRY_H

lldb/source/Core/CMakeLists.txt

@@ -16,6 +16,11 @@ if (LLDB_ENABLE_CURSES)
   endif()
 endif()
 
+if (LLVM_BUILD_TELEMETRY)
+   set(TELEMETRY_SOURCES Telemetry.cpp)
+   set(TELEMETRY_DEPS Telemetry)
+endif()
+
 # TODO: Add property `NO_PLUGIN_DEPENDENCIES` to lldbCore
 add_lldb_library(lldbCore
   Address.cpp
@@ -55,7 +60,8 @@ add_lldb_library(lldbCore
   ThreadedCommunication.cpp
   UserSettingsController.cpp
   Value.cpp
-
+  ${TELEMETRY_SOURCES}
+  PARTIAL_SOURCES_INTENDED
   DEPENDS
     clang-tablegen-targets
 
@@ -80,6 +86,7 @@ add_lldb_library(lldbCore
     Support
     Demangle
     TargetParser
+    ${TELEMETRY_DEPS}
   )
 
 add_dependencies(lldbCore

lldb/source/Core/Telemetry.cpp

@@ -0,0 +1,69 @@
+//===-- Telemetry.cpp -----------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+#include "lldb/Core/Telemetry.h"
+#include "lldb/Core/Debugger.h"
+#include "lldb/Utility/LLDBLog.h"
+#include "lldb/Utility/UUID.h"
+#include "lldb/lldb-enumerations.h"
+#include "lldb/lldb-forward.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/RandomNumberGenerator.h"
+#include "llvm/Telemetry/Telemetry.h"
+#include <chrono>
+#include <cstdlib>
+#include <memory>
+#include <string>
+#include <utility>
+
+namespace lldb_private {
+namespace telemetry {
+
+using ::llvm::Error;
+using ::llvm::telemetry::Destination;
+using ::llvm::telemetry::Serializer;
+using ::llvm::telemetry::TelemetryInfo;
+
+static uint64_t ToNanosec(const SteadyTimePoint Point) {
+  return std::chrono::nanoseconds(Point.time_since_epoch()).count();
+}
+
+void LLDBBaseTelemetryInfo::serialize(Serializer &serializer) const {
+  serializer.write("entry_kind", getKind());
+  serializer.write("session_id", SessionId);
+  serializer.write("start_time", ToNanosec(start_time));
+  if (end_time.has_value())
+    serializer.write("end_time", ToNanosec(end_time.value()));
+}
+
+static std::string MakeUUID(lldb_private::Debugger *debugger) {
+  uint8_t random_bytes[16];
+  if (auto ec = llvm::getRandomBytes(random_bytes, 16)) {
+    LLDB_LOG(GetLog(LLDBLog::Object),
+             "Failed to generate random bytes for UUID: {0}", ec.message());
+    // fallback to using timestamp + debugger ID.
+    return llvm::formatv(
+        "{0}_{1}", std::chrono::steady_clock::now().time_since_epoch().count(),
+        debugger->GetID());
+  }
+  return lldb_private::UUID(random_bytes).GetAsString();
+}
+
+TelemetryManager::TelemetryManager(
+    std::unique_ptr<llvm::telemetry::Config> config)
+    : m_config(std::move(config)) {}
+
+llvm::Error TelemetryManager::preDispatch(TelemetryInfo *entry) {
+  // Do nothing for now.
+  // In up-coming patch, this would be where the manager
+  // attach the session_uuid to the entry.
+  return Error::success();
+}
+
+} // namespace telemetry
+} // namespace lldb_private