Fix background compiler issue with new-space allocation in the parser.

runtime/vm/parser.cc

Index: runtime/vm/parser.cc
diff --git a/runtime/vm/parser.cc b/runtime/vm/parser.cc
index 51f3f882b39b7e2c52d650b63f5d6b3841b909f4..718130f5e9a1252870231a982b1c065d7c8bec98 100644
--- a/runtime/vm/parser.cc
+++ b/runtime/vm/parser.cc
@@ -2357,7 +2357,8 @@ RawFunction* Parser::GetSuperFunction(TokenPosition token_pos,
                                     NULL)) {
     super_func = Function::null();
   } else if (super_func.IsNull() && resolve_getter) {
-    const String& getter_name = String::ZoneHandle(Z, Field::GetterName(name));
+    const String& getter_name =
+        String::ZoneHandle(Z, Field::GetterSymbol(name));
     super_func = Resolver::ResolveDynamicAnyArgs(Z, super_class, getter_name);
     ASSERT(super_func.IsNull() ||
            (super_func.kind() != RawFunction::kImplicitStaticFinalGetter));
@@ -5636,7 +5637,7 @@ void Parser::ParseTopLevelVariable(TopLevel* top_level,
     // or final field implies a setter which throws a NoSuchMethodError,
     // thus we need to check for conflicts with existing setters and
     // getters.
-    String& accessor_name = String::Handle(Z, Field::GetterName(var_name));
+    String& accessor_name = String::Handle(Z, Field::GetterSymbol(var_name));
     if (library_.LookupLocalObject(accessor_name) != Object::null()) {
       ReportError(name_pos, "getter for '%s' is already defined",
                   var_name.ToCString());
@@ -5757,7 +5758,7 @@ void Parser::ParseTopLevelFunction(TopLevel* top_level,
     ReportError(name_pos, "missing '%s' cannot be patched",
                 func_name.ToCString());
   }
-  String& accessor_name = String::Handle(Z, Field::GetterName(func_name));
+  String& accessor_name = String::Handle(Z, Field::GetterSymbol(func_name));
   if (library_.LookupLocalObject(accessor_name) != Object::null()) {
     ReportError(name_pos, "'%s' is already defined as getter",
                 func_name.ToCString());
@@ -11473,7 +11474,7 @@ AstNode* Parser::ParseStaticCall(const Class& cls,
     if (field.IsNull()) {
       // No field, check if we have an explicit getter function.
       const String& getter_name =
-          String::ZoneHandle(Z, Field::GetterName(func_name));
+          String::ZoneHandle(Z, Field::GetterSymbol(func_name));

[hausner, 2017/01/30 23:01:03]

I don't think we want to create a symbol for the getter name unless we know for
sure that the getter exists. Otherwise, we end up creating unnecessary symbols.

[Florian Schneider, 2017/01/30 23:30:23]

Ok, instead I could for example create the temporary string in old-space only if
we're compiling on the background thread. That would be better anyway, since we
would not create old-space garbage for unoptimized compilations.

       const int kNumArguments = 0;  // no arguments.
       func = Resolver::ResolveStatic(cls, getter_name, kNumArguments,
                                      Object::empty_array());
@@ -12084,7 +12085,7 @@ AstNode* Parser::ParseClosurization(AstNode* primary) {
         func = cls.LookupStaticFunction(extractor_name);
         if (func.IsNull()) {
           const String& getter_name =
-              String::Handle(Z, Field::GetterName(extractor_name));
+              String::Handle(Z, Field::GetterSymbol(extractor_name));
           func = cls.LookupStaticFunction(getter_name);
         }
       }