[tracing] Support ConvertableToTraceFormat argument type.

src/tracing/trace-event.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SRC_TRACING_TRACE_EVENT_H_
 #define SRC_TRACING_TRACE_EVENT_H_
 
 #include <stddef.h>
+#include <memory>
 
 #include "base/trace_event/common/trace_event_common.h"
 #include "include/v8-platform.h"
 #include "src/base/atomicops.h"
 #include "src/base/macros.h"
 
 // This header file defines implementation details of how the trace macros in
 // trace_event_common.h collect and store trace events. Anything not
 // implementation-specific should go in trace_macros_common.h instead of here.
 
@@ skipping 94 matching lines @@
 //                    const uint8_t* category_group_enabled,
 //                    const char* name,
 //                    const char* scope,
 //                    uint64_t id,
 //                    uint64_t bind_id,
 //                    int num_args,
 //                    const char** arg_names,
 //                    const uint8_t* arg_types,
 //                    const uint64_t* arg_values,
 //                    unsigned int flags)
-#define TRACE_EVENT_API_ADD_TRACE_EVENT \
-  v8::internal::tracing::TraceEventHelper::GetCurrentPlatform()->AddTraceEvent
+#define TRACE_EVENT_API_ADD_TRACE_EVENT v8::internal::tracing::AddTraceEventImpl
 
 // Set the duration field of a COMPLETE trace event.
 // void TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION(
 //     const uint8_t* category_group_enabled,
 //     const char* name,
 //     uint64_t id)
 #define TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION             \
   v8::internal::tracing::TraceEventHelper::GetCurrentPlatform() \
       ->UpdateTraceEventDuration
 
@@ skipping 312 matching lines @@
 // Simple container for const char* that should be copied instead of retained.
 class TraceStringWithCopy {
  public:
   explicit TraceStringWithCopy(const char* str) : str_(str) {}
   operator const char*() const { return str_; }
 
  private:
   const char* str_;
 };
 
+static V8_INLINE uint64_t AddTraceEventImpl(
+    char phase, const uint8_t* category_group_enabled, const char* name,
+    const char* scope, uint64_t id, uint64_t bind_id, int32_t num_args,
+    const char** arg_names, const uint8_t* arg_types,
+    const uint64_t* arg_values, unsigned int flags) {
+  std::unique_ptr<ConvertableToTraceFormat> arg_convertables[2];
+  if (num_args > 0 && arg_types[0] == TRACE_VALUE_TYPE_CONVERTABLE) {
+    arg_convertables[0].reset(reinterpret_cast<ConvertableToTraceFormat*>(
+        static_cast<intptr_t>(arg_values[0])));
+  }
+  if (num_args > 1 && arg_types[1] == TRACE_VALUE_TYPE_CONVERTABLE) {
+    arg_convertables[1].reset(reinterpret_cast<ConvertableToTraceFormat*>(
+        static_cast<intptr_t>(arg_values[1])));
+  }
+  DCHECK(num_args <= 2);
+  v8::Platform* platform =
+      v8::internal::tracing::TraceEventHelper::GetCurrentPlatform();
+  uint64_t handle = platform->AddTraceEvent(
+      phase, category_group_enabled, name, scope, id, bind_id, num_args,
+      arg_names, arg_types, arg_values, arg_convertables, flags);
+  if (handle) return handle;
+  // TODO(alph): Remove legacy AddTraceEvent call.
+  return platform->AddTraceEvent(phase, category_group_enabled, name, scope, id,

[caseq, 2016/09/23 23:48:34]

just drop this one and let the default implementation of the former to do the
job.

[alph, 2016/09/24 00:24:06]

Done.

+                                 bind_id, num_args, arg_names, arg_types,
+                                 arg_values, flags);
+}
+
 // Define SetTraceValue for each allowed type. It stores the type and
 // value in the return arguments. This allows this API to avoid declaring any
 // structures so that it is portable to third_party libraries.
 #define INTERNAL_DECLARE_SET_TRACE_VALUE(actual_type, union_member,         \
                                          value_type_id)                     \
   static V8_INLINE void SetTraceValue(actual_type arg, unsigned char* type, \
                                       uint64_t* value) {                    \
     TraceValueUnion type_value;                                             \
     type_value.union_member = arg;                                          \
     *type = value_type_id;                                                  \
@@ skipping 20 matching lines @@
 INTERNAL_DECLARE_SET_TRACE_VALUE(const void*, as_pointer,
                                  TRACE_VALUE_TYPE_POINTER)
 INTERNAL_DECLARE_SET_TRACE_VALUE(const char*, as_string,
                                  TRACE_VALUE_TYPE_STRING)
 INTERNAL_DECLARE_SET_TRACE_VALUE(const TraceStringWithCopy&, as_string,
                                  TRACE_VALUE_TYPE_COPY_STRING)
 
 #undef INTERNAL_DECLARE_SET_TRACE_VALUE
 #undef INTERNAL_DECLARE_SET_TRACE_VALUE_INT
 
+static V8_INLINE void SetTraceValue(ConvertableToTraceFormat* convertable_value,
+                                    unsigned char* type, uint64_t* value) {
+  *type = TRACE_VALUE_TYPE_CONVERTABLE;
+  *value = static_cast<uint64_t>(reinterpret_cast<intptr_t>(convertable_value));
+}
+
+template <class T>
+static V8_INLINE void SetTraceValue(std::unique_ptr<T> ptr, unsigned char* type,

[caseq, 2016/09/23 23:48:34]

nit: consider std::enable_if<std::is_convertible<T, ConvertibleToTraceFormat>>

[alph, 2016/09/24 00:24:06]

Done.

+                                    uint64_t* value) {
+  SetTraceValue(static_cast<ConvertableToTraceFormat*>(ptr.release()), type,
+                value);
+}
+
 // These AddTraceEvent template
 // function is defined here instead of in the macro, because the arg_values
 // could be temporary objects, such as std::string. In order to store
 // pointers to the internal c_str and pass through to the tracing API,
 // the arg_values must live throughout these procedures.
 
 static V8_INLINE uint64_t AddTraceEvent(char phase,
                                         const uint8_t* category_group_enabled,
                                         const char* name, const char* scope,
                                         uint64_t id, uint64_t bind_id,
                                         unsigned int flags) {
   return TRACE_EVENT_API_ADD_TRACE_EVENT(phase, category_group_enabled, name,
-                                         scope, id, bind_id, kZeroNumArgs, NULL,
-                                         NULL, NULL, flags);
+                                         scope, id, bind_id, kZeroNumArgs,
+                                         nullptr, nullptr, nullptr, flags);
 }
 
 template <class ARG1_TYPE>
 static V8_INLINE uint64_t AddTraceEvent(
     char phase, const uint8_t* category_group_enabled, const char* name,
     const char* scope, uint64_t id, uint64_t bind_id, unsigned int flags,
-    const char* arg1_name, const ARG1_TYPE& arg1_val) {
+    const char* arg1_name, ARG1_TYPE&& arg1_val) {
   const int num_args = 1;
-  uint8_t arg_types[1];
-  uint64_t arg_values[1];
-  SetTraceValue(arg1_val, &arg_types[0], &arg_values[0]);
+  uint8_t arg_type;
+  uint64_t arg_value;
+  SetTraceValue(std::forward<ARG1_TYPE>(arg1_val), &arg_type, &arg_value);
   return TRACE_EVENT_API_ADD_TRACE_EVENT(
       phase, category_group_enabled, name, scope, id, bind_id, num_args,
-      &arg1_name, arg_types, arg_values, flags);
+      &arg1_name, &arg_type, &arg_value, flags);
 }
 
 template <class ARG1_TYPE, class ARG2_TYPE>
 static V8_INLINE uint64_t AddTraceEvent(
     char phase, const uint8_t* category_group_enabled, const char* name,
     const char* scope, uint64_t id, uint64_t bind_id, unsigned int flags,
-    const char* arg1_name, const ARG1_TYPE& arg1_val, const char* arg2_name,
-    const ARG2_TYPE& arg2_val) {
+    const char* arg1_name, ARG1_TYPE&& arg1_val, const char* arg2_name,
+    ARG2_TYPE&& arg2_val) {
   const int num_args = 2;
   const char* arg_names[2] = {arg1_name, arg2_name};
   unsigned char arg_types[2];
   uint64_t arg_values[2];
-  SetTraceValue(arg1_val, &arg_types[0], &arg_values[0]);
-  SetTraceValue(arg2_val, &arg_types[1], &arg_values[1]);
+  SetTraceValue(std::forward<ARG1_TYPE>(arg1_val), &arg_types[0],
+                &arg_values[0]);
+  SetTraceValue(std::forward<ARG2_TYPE>(arg2_val), &arg_types[1],
+                &arg_values[1]);
   return TRACE_EVENT_API_ADD_TRACE_EVENT(
       phase, category_group_enabled, name, scope, id, bind_id, num_args,
       arg_names, arg_types, arg_values, flags);
 }
 
 // Used by TRACE_EVENTx macros. Do not use directly.
 class ScopedTracer {
  public:
   // Note: members of data_ intentionally left uninitialized. See Initialize.
   ScopedTracer() : p_data_(NULL) {}
@@ skipping 92 matching lines @@
   bool has_parent_scope_;
   Data* p_data_;
   Data data_;
 };
 
 }  // namespace tracing
 }  // namespace internal
 }  // namespace v8
 
 #endif  // SRC_TRACING_TRACE_EVENT_H_