[ast/parsing] Pessimistically assume all top-level variables will be assigned.

src/parsing/parser.h

Index: src/parsing/parser.h
diff --git a/src/parsing/parser.h b/src/parsing/parser.h
index 0ae8fb9cd100270fb29be1e1287c15b927420f40..d2dcca1a08f649948670f8e9531dcc592484c8af 100644
--- a/src/parsing/parser.h
+++ b/src/parsing/parser.h
@@ -823,6 +823,18 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
     }
   }
 
+  // We have to pessimistically assume that top-level variables will be
+  // assigned.  This is because they might be accessed by a lazily parsed

[marja, 2017/01/25 12:44:10]

You could fix this comment in this CL :) (There's already discussion about it in
the previous one.)

+  // top-level function, which, for efficiency, we preparse without
+  // variable tracking.  In the case of a script (not a module), they
+  // might also get accessed by another script.
+  V8_INLINE static void MarkTopLevelVariableAsAssigned(Scope* scope,
+                                                       VariableProxy* proxy) {
+    if (scope->is_script_scope() || scope->is_module_scope()) {

[adamk, 2017/01/27 16:07:36]

I thought we currently disable preparsing of functions in modules, and changing
that was blocked on marja's work to preparse inner functions.

Or am I confused and we instead force context allocation for all module-scoped
variables?

+      proxy->set_is_assigned();
+    }
+  }
+
   // Returns true if we have a binary expression between two numeric
   // literals. In that case, *x will be changed to an expression which is the
   // computed value.