Allow setting breakpoints in function literal field initializers under --dfe.

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 6d9a944cf86920a3c40ded06df66a65878284de7..c014d3337f42713cd01bc4a221b96ef104811ef7 100644
--- a/runtime/vm/kernel_reader.cc
+++ b/runtime/vm/kernel_reader.cc
@@ -9,6 +9,7 @@
 #include "vm/dart_api_impl.h"
 #include "vm/kernel_binary.h"
 #include "vm/kernel_binary_flowgraph.h"
+#include "vm/kernel_to_il.h"
 #include "vm/longjump.h"
 #include "vm/object_store.h"
 #include "vm/parser.h"
@@ -881,6 +882,29 @@ RawFunction::Kind KernelReader::GetFunctionType(
   }
 }
 
+bool KernelReader::FieldHasFunctionLiteralInitializer(const dart::Field& field,
+                                                      TokenPosition* start,
+                                                      TokenPosition* end) {
+  dart::Zone* zone = Thread::Current()->zone();
+  const Script& script = Script::Handle(zone, field.Script());

[siva, 2017/07/18 22:49:07]

KernelReader seems to have a zone_ field so I guess you should be able to do
const Script& script = Script::Handle(Z, field.Script());

[sivachandra, 2017/07/19 00:14:22]

This new method is a static method. So, kernel fields are not accessible here.

+
+  TranslationHelper translation_helper(
+      Thread::Current(), script.kernel_string_offsets(),

[siva, 2017/07/18 22:49:07]

KernelReader also has a thread_ field that you should be able to use instead of
Thread::Current();

[sivachandra, 2017/07/19 00:14:22]

Same reason as above that this is a static method.

+      script.kernel_string_data(), script.kernel_canonical_names());
+
+  kernel::StreamingFlowGraphBuilder* builder =
+      new kernel::StreamingFlowGraphBuilder(&translation_helper, zone,
+                                            script.kernel_data(),
+                                            script.kernel_data_size());
+
+  kernel::FieldHelper field_helper(builder, field.kernel_offset());
+  field_helper.ReadUntilExcluding(kernel::FieldHelper::kEnd, true);
+  bool result = field_helper.FieldHasFunctionLiteralInitializer(start, end);
+
+  delete builder;
+  return result;
+}
+
 ParsedFunction* ParseStaticFieldInitializer(Zone* zone,
                                             const dart::Field& field) {
   Thread* thread = Thread::Current();