Make non-Module generators only context allocate parameters.

src/ast/scopes.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_AST_SCOPES_H_
 #define V8_AST_SCOPES_H_
 
 #include "src/base/compiler-specific.h"
 #include "src/base/hashmap.h"
 #include "src/globals.h"
@@ skipping 305 matching lines @@
   void set_is_hidden() { is_hidden_ = true; }
 
   // In some cases we want to force context allocation for a whole scope.
   void ForceContextAllocation() {
     DCHECK(!already_resolved_);
     force_context_allocation_ = true;
   }
   bool has_forced_context_allocation() const {
     return force_context_allocation_;
   }
+  void ForceContextAllocationForParameters() {
+    DCHECK(!already_resolved_);
+    force_context_allocation_for_parameters_ = true;
+  }
+  bool has_forced_context_allocation_for_parameters() const {
+    return force_context_allocation_for_parameters_;
+  }
 

[neis, 2017/05/24 10:39:37]

I don't like the fact that has_forced_context_allocation() does not imply
has_forced_context_allocation_for_parameters().

How about having an enum ForcedContextAllocation { None, ParametersOnly,
Everything }?

[Jarin, 2017/05/24 12:32:21]

Not sure. Adam, do you think it is a good idea?

[adamk, 2017/05/24 13:04:00]

I think an enum is fine if Georg finds this confusing. I agree the current
naming is ambiguous.

   // ---------------------------------------------------------------------------
   // Predicates.
 
   // Specific scope types.
   bool is_eval_scope() const { return scope_type_ == EVAL_SCOPE; }
   bool is_function_scope() const { return scope_type_ == FUNCTION_SCOPE; }
   bool is_module_scope() const { return scope_type_ == MODULE_SCOPE; }
   bool is_script_scope() const { return scope_type_ == SCRIPT_SCOPE; }
   bool is_catch_scope() const { return scope_type_ == CATCH_SCOPE; }
   bool is_block_scope() const { return scope_type_ == BLOCK_SCOPE; }
@@ skipping 230 matching lines @@
   bool scope_calls_eval_ : 1;
   // This scope's declarations might not be executed in order (e.g., switch).
   bool scope_nonlinear_ : 1;
   bool is_hidden_ : 1;
   // Temporary workaround that allows masking of 'this' in debug-evalute scopes.
   bool is_debug_evaluate_scope_ : 1;
 
   // True if one of the inner scopes or the scope itself calls eval.
   bool inner_scope_calls_eval_ : 1;
   bool force_context_allocation_ : 1;
+  bool force_context_allocation_for_parameters_ : 1;
 
   // True if it holds 'var' declarations.
   bool is_declaration_scope_ : 1;
 
   bool must_use_preparsed_scope_data_ : 1;
 
   // Create a non-local variable with a given name.
   // These variables are looked up dynamically at runtime.
   Variable* NonLocal(const AstRawString* name, VariableMode mode);
 
@@ skipping 421 matching lines @@
   void AllocateModuleVariables();
 
  private:
   ModuleDescriptor* module_descriptor_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_AST_SCOPES_H_