Coverage: add a trace for not_covered_lines per file

tools/parse_llvm_coverage.py

Index: tools/parse_llvm_coverage.py
diff --git a/tools/parse_llvm_coverage.py b/tools/parse_llvm_coverage.py
index 2eadddd3cb1f7615758df257d92b5955648462c2..ac8ba51fbf59bac20ba6b68e6dffd4f93d733236 100755
--- a/tools/parse_llvm_coverage.py
+++ b/tools/parse_llvm_coverage.py
@@ -103,16 +103,24 @@ def _nanobench_json(results, properties, key):
   # dict containing those keys.
   rv.update(properties)
   rv['key'] = key
+  rv['key'].update({'source_type': 'coverage'})
   rv['results'] = {
     _testname(f): {
-      'coverage': {

[mtklein, 2015/07/22 12:20:26]

Am I remembering this format wrong or do we want it like this?

'coverage': {
  'percent': percent,
  'lines_not_covered': lines_not_covered,
  'options': {
     'fullname': f,
     'dir': os.path.dirname(f),
     'source_type': 'coverage',
  }
}

Though, 'coverage' is already splattered around there enough that I don't know
we're going to get any real value from an extra source_type: coverage.  

I'm pretty sure source_type does not belong in the key, though.  The key
determines the identity of the trace (line on perf) so it wouldn't hurt here
(adding anything wouldn't hurt as long as it was always the same anything) but
it's also not necessary unless we're trying to make a distinction.  E.g., if we
had two different ways of getting coverage on the same machine and we wanted to
plot them as two lines, we'd need to make sure the key had 'coverage_tool:
clang' or 'coverage_tool: gcov'  (or whatever).

[borenet, 2015/07/22 13:01:59]

So one of my concerns was preventing clustering with actual perf results; I was
hoping that providing source_type might cause that to happen.  From what I could
tell, putting source_type in the key section caused it to apply to all of the
results, which saves some space over including it in each result.  It's no
problem to move it though.

-        'percent': percent,
+      'covered_percent': {
+        'value': percent,
         'options': {
           'fullname': f,
           'dir': os.path.dirname(f),
         },
       },
-    } for percent, f in results
+      'lines_not_covered': {
+        'value': not_covered_lines,
+        'options': {
+          'fullname': f,
+          'dir': os.path.dirname(f),
+        },
+      },
+    } for percent, not_covered_lines, f in results
   }
   return rv
 
@@ -150,6 +158,7 @@ def _get_per_file_summaries(line_by_line):
           covered_lines += 1
     if total_lines > 0:
       per_file.append((float(covered_lines)/float(total_lines)*100.0,
+                       total_lines - covered_lines,
                        filepath))
   return per_file