Extend CPU profiler with mapping ticks to source lines

src/cpu-profiler.cc

Index: src/cpu-profiler.cc
diff --git a/src/cpu-profiler.cc b/src/cpu-profiler.cc
index 68a565c73a2ffa4469948a1aa36b52e565f6947a..115324c459a1961e93dc225bd7414bd8b73af8bc 100644
--- a/src/cpu-profiler.cc
+++ b/src/cpu-profiler.cc
@@ -256,20 +256,38 @@ void CpuProfiler::CodeCreateEvent(Logger::LogEventsAndTags tag, Code* code,
   CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
   CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
   rec->start = code->address();
+  Script* script = NULL;
+  JITLineInfoTable* line_table = NULL;
+  if (shared->script()->IsScript()) {

[alph, 2014/08/15 12:10:47]

Is it possible the shared->script() is not a Script? I see previously it was not
the case.

[Denis Pravdin, 2014/08/23 05:18:52]

I reused the same pattern as
CpuProfiler::CodeCreateEvent(Logger::LogEventsAndTags tag, Code* code,
SharedFunctionInfo* shared, CompilationInfo* info, Name* script_name) has.
It does the same check. Is it OK?

[Denis Pravdin, 2014/09/01 10:44:38]

I reused the same pattern as
CpuProfiler::CodeCreateEvent(Logger::LogEventsAndTags tag, Code* code,
SharedFunctionInfo* shared, CompilationInfo* info, Name* script_name) has.
It does the same check. Is it OK?

On 2014/08/15 12:10:47, alph wrote:

[alph, 2014/09/09 14:47:34]

That function is called from a different place, so it may have different
assumptions about script().

This function does always have script() pointing to the correct Script object,
so the check is not necessary.

+    DCHECK(Script::cast(shared->script()));
+    script = Script::cast(shared->script());

[alph, 2014/08/15 12:10:47]

Script::cast does the DCHECK internally so you don't really need to do it here.
Anyway if you still want to double check, could you please write:

script = Script::cast(shared->script());
DCHECK(script);

+    line_table = new JITLineInfoTable();
+    for (RelocIterator it(code); !it.done(); it.next()) {
+      RelocInfo::Mode mode = it.rinfo()->rmode();
+      if (RelocInfo::IsPosition(mode)) {
+        int position = static_cast<int>(it.rinfo()->data());
+        if (position >= 0) {
+          int pc_offset = static_cast<int>(it.rinfo()->pc() - code->address());
+          int line_number = script->GetLineNumber(position) + 1;
+          line_table->SetPosition(pc_offset, line_number);
+        }
+      }
+    }
+  }
   rec->entry = profiles_->NewCodeEntry(
       tag, profiles_->GetFunctionName(shared->DebugName()),
       CodeEntry::kEmptyNamePrefix, profiles_->GetName(script_name), line,
-      column);
+      column, line_table);
   if (info) {
     rec->entry->set_no_frame_ranges(info->ReleaseNoFrameRanges());
   }
-  DCHECK(Script::cast(shared->script()));
-  Script* script = Script::cast(shared->script());
-  rec->entry->set_script_id(script->id()->value());
-  rec->size = code->ExecutableSize();
-  rec->shared = shared->address();
+  if (script) {
+    rec->entry->set_script_id(script->id()->value());
+  }
   rec->entry->set_bailout_reason(
       GetBailoutReason(shared->DisableOptimizationReason()));
+  rec->size = code->ExecutableSize();
+  rec->shared = shared->address();
   processor_->Enqueue(evt_rec);
 }