Assign unique IDs to FunctionLiterals

src/ast/ast.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_AST_H_
 #define V8_AST_AST_H_
 
 #include "src/ast/ast-types.h"
 #include "src/ast/ast-value-factory.h"
 #include "src/ast/modules.h"
@@ skipping 2693 matching lines @@
   }
   void set_is_class_field_initializer(bool is_class_field_initializer) {
     bit_field_ =
         IsClassFieldInitializer::update(bit_field_, is_class_field_initializer);
   }
 
   int return_position() {
     return std::max(start_position(), end_position() - (has_braces_ ? 1 : 0));
   }
 
+  int function_literal_num() const { return function_literal_num_; }
+
  private:
   friend class AstNodeFactory;
 
   FunctionLiteral(Zone* zone, const AstString* name,
                   AstValueFactory* ast_value_factory, DeclarationScope* scope,
                   ZoneList<Statement*>* body, int materialized_literal_count,
                   int expected_property_count, int parameter_count,
                   int function_length, FunctionType function_type,
                   ParameterFlag has_duplicate_parameters,
                   EagerCompileHint eager_compile_hint, int position,
-                  bool is_function, bool has_braces)
+                  bool is_function, bool has_braces, int function_literal_num)
       : Expression(position, kFunctionLiteral),
         materialized_literal_count_(materialized_literal_count),
         expected_property_count_(expected_property_count),
         parameter_count_(parameter_count),
         function_length_(function_length),
         function_token_position_(kNoSourcePosition),
         yield_count_(0),
         has_braces_(has_braces),
         raw_name_(name),
         scope_(scope),
         body_(body),
         raw_inferred_name_(ast_value_factory->empty_string()),
-        ast_properties_(zone) {
+        ast_properties_(zone),
+        function_literal_num_(function_literal_num) {
     bit_field_ |=
         FunctionTypeBits::encode(function_type) | Pretenure::encode(false) |
         HasDuplicateParameters::encode(has_duplicate_parameters ==
                                        kHasDuplicateParameters) |
         IsFunction::encode(is_function) |
         RequiresClassFieldInit::encode(false) |
         ShouldNotBeUsedOnceHintField::encode(false) |
         DontOptimizeReasonField::encode(kNoReason) |
         IsClassFieldInitializer::encode(false);
     if (eager_compile_hint == kShouldEagerCompile) SetShouldEagerCompile();
@@ skipping 20 matching lines @@
   int function_token_position_;
   int yield_count_;
   bool has_braces_;
 
   const AstString* raw_name_;
   DeclarationScope* scope_;
   ZoneList<Statement*>* body_;
   const AstString* raw_inferred_name_;
   Handle<String> inferred_name_;
   AstProperties ast_properties_;
+  int function_literal_num_;
 };
 
 // Property is used for passing information
 // about a class literal's properties from the parser to the code generator.
 class ClassLiteralProperty final : public LiteralProperty {
  public:
   enum Kind : uint8_t { METHOD, GETTER, SETTER, FIELD };
 
   Kind kind() const { return kind_; }
 
@@ skipping 669 matching lines @@
     return new (zone_) Throw(exception, pos);
   }
 
   FunctionLiteral* NewFunctionLiteral(
       const AstRawString* name, DeclarationScope* scope,
       ZoneList<Statement*>* body, int materialized_literal_count,
       int expected_property_count, int parameter_count, int function_length,
       FunctionLiteral::ParameterFlag has_duplicate_parameters,
       FunctionLiteral::FunctionType function_type,
       FunctionLiteral::EagerCompileHint eager_compile_hint, int position,
-      bool has_braces) {
+      bool has_braces, int function_literal_num) {
     return new (zone_) FunctionLiteral(
         zone_, name, ast_value_factory_, scope, body,
         materialized_literal_count, expected_property_count, parameter_count,
         function_length, function_type, has_duplicate_parameters,
-        eager_compile_hint, position, true, has_braces);
+        eager_compile_hint, position, true, has_braces, function_literal_num);
   }
 
   // Creates a FunctionLiteral representing a top-level script, the
   // result of an eval (top-level or otherwise), or the result of calling
   // the Function constructor.
   FunctionLiteral* NewScriptOrEvalFunctionLiteral(
       DeclarationScope* scope, ZoneList<Statement*>* body,
       int materialized_literal_count, int expected_property_count,
       int parameter_count) {
     return new (zone_) FunctionLiteral(
         zone_, ast_value_factory_->empty_string(), ast_value_factory_, scope,
         body, materialized_literal_count, expected_property_count,
         parameter_count, parameter_count, FunctionLiteral::kAnonymousExpression,
         FunctionLiteral::kNoDuplicateParameters,
-        FunctionLiteral::kShouldLazyCompile, 0, false, true);
+        FunctionLiteral::kShouldLazyCompile, 0, false, true, 0);

[marja, 2016/11/18 10:48:04]

What does 0 mean here? Invalid? Or just some default value? How about defining a
constant for it?

Why is it ok that multiple FunctionLiterals created via this code path have the
same ID? Why doesn't that break anything? (Maybe add a comment which answers
that question.)

[jochen (gone - plz use gerrit), 2016/11/21 08:03:47]

-1 means invalid, zero means top-level function. added named constants

   }
 
   ClassLiteral::Property* NewClassLiteralProperty(
       Expression* key, Expression* value, ClassLiteralProperty::Kind kind,
       bool is_static, bool is_computed_name) {
     return new (zone_)
         ClassLiteral::Property(key, value, kind, is_static, is_computed_name);
   }
 
   ClassLiteral* NewClassLiteral(VariableProxy* proxy, Expression* extends,
@@ skipping 105 matching lines @@
                                     : NULL;                                   \
   }
 AST_NODE_LIST(DECLARE_NODE_FUNCTIONS)
 #undef DECLARE_NODE_FUNCTIONS
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_AST_AST_H_