This patch is the propagation version of https://codereview.chromium.org/10824032 patch

src/assembler.cc

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // 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.
 //
@@ skipping 1504 matching lines @@
 
 void PositionsRecorder::RecordPosition(int pos) {
   ASSERT(pos != RelocInfo::kNoPosition);
   ASSERT(pos >= 0);
   state_.current_position = pos;
 #ifdef ENABLE_GDB_JIT_INTERFACE
   if (gdbjit_lineinfo_ != NULL) {
     gdbjit_lineinfo_->SetPosition(assembler_->pc_offset(), pos, false);
   }
 #endif
+  if (user_data_ != NULL) {

[danno, 2013/02/01 13:43:10]

Why conditionally call? It seems like you should _always_ call the logger to log
the event, if the handler chooses to ignore the event then this null check
should be inside the handler.

+    LOG_CODE_EVENT(this->assembler()->isolate(),
+                   CodeLinePosInfoAddEvent(user_data_,
+                                           assembler_->pc_offset(),
+                                           pos,
+                                           JitCodeEvent::POSITION));
+  }
 }
 
 
 void PositionsRecorder::RecordStatementPosition(int pos) {
   ASSERT(pos != RelocInfo::kNoPosition);
   ASSERT(pos >= 0);
   state_.current_statement_position = pos;
 #ifdef ENABLE_GDB_JIT_INTERFACE
   if (gdbjit_lineinfo_ != NULL) {
     gdbjit_lineinfo_->SetPosition(assembler_->pc_offset(), pos, true);
   }
 #endif
+  if (user_data_ != NULL) {

[danno, 2013/02/01 13:43:10]

Same comment as above (please always call LOG_CODE_EVENT)

+    LOG_CODE_EVENT(this->assembler()->isolate(),
+                   CodeLinePosInfoAddEvent(user_data_,
+                                           assembler_->pc_offset(),
+                                           pos,
+                                           JitCodeEvent::STATEMENT_POSITION));
+  }
 }
 
 
 bool PositionsRecorder::WriteRecordedPositions() {
   bool written = false;
 
   // Write the statement position if it is different from what was written last
   // time.
   if (state_.current_statement_position != state_.written_statement_position) {
     EnsureSpace ensure_space(assembler_);
@@ skipping 11 matching lines @@
     assembler_->RecordRelocInfo(RelocInfo::POSITION, state_.current_position);
     state_.written_position = state_.current_position;
     written = true;
   }
 
   // Return whether something was written.
   return written;
 }
 
 } }  // namespace v8::internal