RELOAD: Maintain identity of static tear-offs.

runtime/vm/isolate_reload.cc

Index: runtime/vm/isolate_reload.cc
diff --git a/runtime/vm/isolate_reload.cc b/runtime/vm/isolate_reload.cc
index 9a67be9f5369bfc3a842bc4857c033dc03e9fc69..eabaf2e550234a0b469e31d8769066c854bcddb3 100644
--- a/runtime/vm/isolate_reload.cc
+++ b/runtime/vm/isolate_reload.cc
@@ -960,9 +960,14 @@ void IsolateReloadContext::Commit() {
     // Copy static field values from the old classes to the new classes.
     // Patch fields and functions in the old classes so that they retain
     // the old script.
-    Class& cls = Class::Handle();
+    Class& old_cls = Class::Handle();
     Class& new_cls = Class::Handle();
-
+    Array& functions = Array::Handle();
+    Function& old_func = Function::Handle();
+    String& selector = String::Handle();
+    Function& new_func = Function::Handle();
+    Instance& old_closure = Instance::Handle();
+    Instance& new_closure = Instance::Handle();
     UnorderedHashMap<ClassMapTraits> class_map(class_map_storage_);
 
     {
@@ -970,15 +975,33 @@ void IsolateReloadContext::Commit() {
       while (it.MoveNext()) {
         const intptr_t entry = it.Current();
         new_cls = Class::RawCast(class_map.GetKey(entry));
-        cls = Class::RawCast(class_map.GetPayload(entry, 0));
-        if (new_cls.raw() != cls.raw()) {
-          ASSERT(new_cls.is_enum_class() == cls.is_enum_class());
+        old_cls = Class::RawCast(class_map.GetPayload(entry, 0));
+        if (new_cls.raw() != old_cls.raw()) {
+          ASSERT(new_cls.is_enum_class() == old_cls.is_enum_class());
           if (new_cls.is_enum_class() && new_cls.is_finalized()) {
-            new_cls.ReplaceEnum(cls);
+            new_cls.ReplaceEnum(old_cls);
           } else {
-            new_cls.CopyStaticFieldValues(cls);
+            new_cls.CopyStaticFieldValues(old_cls);
+          }
+          old_cls.PatchFieldsAndFunctions();
+
+          // Map implicit static closures.
+          functions = old_cls.functions();

[Cutch, 2016/08/01 22:26:04]

please factor this into a function that lives in object_reload.cc

[rmacnak, 2016/08/02 00:43:45]

Done.

+          for (intptr_t i = 0; i < functions.Length(); i++) {
+            old_func ^= functions.At(i);
+            if (old_func.is_static() &&
+                old_func.HasImplicitClosureFunction()) {
+              selector = old_func.name();
+              new_func = new_cls.LookupFunction(selector);
+              if (!new_func.IsNull() && new_func.is_static()) {
+                old_func = old_func.ImplicitClosureFunction();
+                old_closure = old_func.ImplicitStaticClosure();
+                new_func = new_func.ImplicitClosureFunction();
+                new_closure = new_func.ImplicitStaticClosure();
+                AddBecomeMapping(old_closure, new_closure);
+              }
+            }
           }

[turnidge, 2016/08/01 21:04:28]

Perhaps this should be implemented in a separate function on Class.  You might
need to expose AddBecomeMapping.

-          cls.PatchFieldsAndFunctions();
         }
       }
     }