Lazily format LanguageError messages (fix issue 15069).

runtime/vm/flow_graph.cc

Index: runtime/vm/flow_graph.cc
===================================================================
--- runtime/vm/flow_graph.cc	(revision 30298)
+++ runtime/vm/flow_graph.cc	(working copy)
@@ -1068,12 +1068,17 @@
 
 void FlowGraph::Bailout(const char* reason) const {
   const char* kFormat = "FlowGraph Bailout: %s %s";
-  const char* function_name = parsed_function_.function().ToCString();
+  const Function& function = parsed_function_.function();
+  const char* function_name = function.ToCString();
   intptr_t len = OS::SNPrint(NULL, 0, kFormat, function_name, reason) + 1;
   char* chars = Isolate::Current()->current_zone()->Alloc<char>(len);
   OS::SNPrint(chars, len, kFormat, function_name, reason);
   const Error& error = Error::Handle(
-      LanguageError::New(String::Handle(String::New(chars))));
+      LanguageError::New(Error::Handle(),  // No previous error.
+                         Script::Handle(function.script()),

[Ivan Posva, 2013/11/15 04:42:13]

Now that we report script and position, do we really need to get the function
name into the error message as well?

In any case you could use "LanguageError::NewFormatted(..., kFormat,
function_name, reason)" here, to avoid the duplication of the formatting code.

[regis, 2013/11/15 18:27:38]

Done.

+                         function.token_pos(),
+                         LanguageError::kError,
+                         String::Handle(String::New(chars))));
   Isolate::Current()->long_jump_base()->Jump(1, error);
 }