Add an explicit way of making IDs local or global

base/trace_event/trace_event_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/trace_event/trace_event_impl.h"
 
 #include <stddef.h>
 
 #include "base/format_macros.h"
 #include "base/json/string_escape.h"
@@ skipping 340 matching lines @@
     StringAppendF(out, ",\"tts\":%" PRId64, thread_time_int64);
   }
 
   // Output async tts marker field if flag is set.
   if (flags_ & TRACE_EVENT_FLAG_ASYNC_TTS) {
     StringAppendF(out, ", \"use_async_tts\":1");
   }
 
   // If id_ is set, print it out as a hex string so we don't loose any
   // bits (it might be a 64-bit pointer).
-  if (flags_ & TRACE_EVENT_FLAG_HAS_ID) {
+  unsigned int id_flags_ = flags_ & (TRACE_EVENT_FLAG_HAS_ID |
+                                     TRACE_EVENT_FLAG_HAS_LOCAL_ID |
+                                     TRACE_EVENT_FLAG_HAS_GLOBAL_ID);
+  if (id_flags_) {
     if (scope_ != trace_event_internal::kGlobalScope)
       StringAppendF(out, ",\"scope\":\"%s\"", scope_);
-    StringAppendF(out, ",\"id\":\"0x%" PRIx64 "\"", static_cast<uint64_t>(id_));
+
+    switch (id_flags_) {
+      case TRACE_EVENT_FLAG_HAS_ID:
+        StringAppendF(out, ",\"id\":\"0x%" PRIx64 "\"",
+                      static_cast<uint64_t>(id_));
+        break;
+
+      case TRACE_EVENT_FLAG_HAS_LOCAL_ID:
+        StringAppendF(out, ",\"id2\":{\"local\":\"0x%" PRIx64 "\"}",
+                      static_cast<uint64_t>(id_));
+        break;
+
+      case TRACE_EVENT_FLAG_HAS_GLOBAL_ID:
+        StringAppendF(out, ",\"id2\":{\"global\":\"0x%" PRIx64 "\"}",
+                      static_cast<uint64_t>(id_));
+        break;
+
+      default:
+        NOTREACHED() << "More than one of the ID flags are set";
+        break;
+    }
   }
 
   if (flags_ & TRACE_EVENT_FLAG_BIND_TO_ENCLOSING)
     StringAppendF(out, ",\"bp\":\"e\"");
 
   if ((flags_ & TRACE_EVENT_FLAG_FLOW_OUT) ||
       (flags_ & TRACE_EVENT_FLAG_FLOW_IN) ||
       phase_ == TRACE_EVENT_PHASE_BIND_IDS) {
     StringAppendF(out, ",\"bind_id\":\"0x%" PRIx64 "\"",
                   static_cast<uint64_t>(bind_id_));
@@ skipping 43 matching lines @@
         AppendValueAsJSON(arg_types_[i], arg_values_[i], &value_as_text);
 
       *out << value_as_text;
     }
     *out << "}";
   }
 }
 
 }  // namespace trace_event
 }  // namespace base