Debugging in kernel shaping up.

runtime/vm/kernel_reader.cc

Index: runtime/vm/kernel_reader.cc
diff --git a/runtime/vm/kernel_reader.cc b/runtime/vm/kernel_reader.cc
index f0be6f6fb9b25b868359d98b11ba218fe52377a2..2e1fac9c104d883e6befb40971222439c9c9935a 100644
--- a/runtime/vm/kernel_reader.cc
+++ b/runtime/vm/kernel_reader.cc
@@ -450,6 +450,45 @@ const Object& KernelReader::ClassForScriptAt(const dart::Class& klass,
   return klass;
 }
 
+static int LowestFirst(const intptr_t* a, const intptr_t* b) {
+  return *a - *b;
+}
+
+/**
+ * If index exists as sublist in list, sort the sublist from lowest to highest,
+ * then copy it, as Smis and without duplicates,
+ * to a new Array in Heap::kOld which is returned.
+ * Note that the source list is both sorted and de-duplicated as well, but will
+ * possibly contain duplicate and unsorted data at the end.
+ * Otherwise (when sublist doesn't exist in list) return new empty array.
+ */
+static RawArray* AsSortedDuplicateFreeArray(
+    intptr_t index,
+    MallocGrowableArray<MallocGrowableArray<intptr_t>*>* list) {
+  if ((index < list->length()) && (list->At(index)->length() > 0)) {
+    MallocGrowableArray<intptr_t>* source = list->At(index);
+    source->Sort(LowestFirst);
+
+    intptr_t size = source->length();
+    intptr_t last = 0;
+    for (intptr_t current = 1; current < size; ++current) {
+      if (source->At(last) != source->At(current)) {
+        (*source)[++last] = source->At(current);
+      }
+    }
+    Array& array_object = Array::Handle();
+    array_object ^= Array::New(last + 1, Heap::kOld);
+    Smi& smi_value = Smi::Handle();
+    for (intptr_t i = 0; i <= last; ++i) {
+      smi_value = Smi::New(source->At(i));
+      array_object.SetAt(i, smi_value);
+    }
+    return array_object.raw();
+  } else {
+    return Array::New(0);
+  }
+}
+
 Script& KernelReader::ScriptAt(intptr_t source_uri_index, String* import_uri) {
   Script& script = Script::ZoneHandle(Z);
   script ^= scripts_.At(source_uri_index);
@@ -477,6 +516,16 @@ Script& KernelReader::ScriptAt(intptr_t source_uri_index, String* import_uri) {
       array_object.SetAt(i, value);
     }
     script.set_line_starts(array_object);
+
+    // Create tokens_seen array for the script.
+    array_object ^= AsSortedDuplicateFreeArray(
+        source_uri_index, &program_->valid_token_positions);
+    script.set_debug_positions(array_object);
+
+    // Create yield_positions array for the script.
+    array_object ^= AsSortedDuplicateFreeArray(
+        source_uri_index, &program_->yield_token_positions);
+    script.set_yield_positions(array_object);
   }
   return script;
 }