Line data    Source code

       1             : // Copyright 2006-2009 the V8 project authors. All rights reserved.
       2             : // Use of this source code is governed by a BSD-style license that can be
       3             : // found in the LICENSE file.
       4             : 
       5             : #ifndef V8_PARSING_FUNC_NAME_INFERRER_H_
       6             : #define V8_PARSING_FUNC_NAME_INFERRER_H_
       7             : 
       8             : #include "src/zone/zone.h"
       9             : 
      10             : namespace v8 {
      11             : namespace internal {
      12             : 
      13             : class AstConsString;
      14             : class AstRawString;
      15             : class AstValueFactory;
      16             : class FunctionLiteral;
      17             : 
      18             : enum class InferName { kYes, kNo };
      19             : 
      20             : // FuncNameInferrer is a stateful class that is used to perform name
      21             : // inference for anonymous functions during static analysis of source code.
      22             : // Inference is performed in cases when an anonymous function is assigned
      23             : // to a variable or a property (see test-func-name-inference.cc for examples.)
      24             : //
      25             : // The basic idea is that during parsing of LHSs of certain expressions
      26             : // (assignments, declarations, object literals) we collect name strings,
      27             : // and during parsing of the RHS, a function literal can be collected. After
      28             : // parsing the RHS we can infer a name for function literals that do not have
      29             : // a name.
      30             : class FuncNameInferrer : public ZoneObject {
      31             :  public:
      32             :   FuncNameInferrer(AstValueFactory* ast_value_factory, Zone* zone);
      33             : 
      34             :   // To enter function name inference state, put a FuncNameInferrer::State
      35             :   // on the stack.
      36             :   class State {
      37             :    public:
      38   166147175 :     explicit State(FuncNameInferrer* fni) : fni_(fni) {
      39   166147175 :       if (fni_ != nullptr) fni_->Enter();
      40   166147219 :     }
      41             :     ~State() {
      42   166071066 :       if (fni_ != nullptr) fni_->Leave();
      43             :     }
      44             : 
      45             :    private:
      46             :     FuncNameInferrer* fni_;
      47             : 
      48             :     DISALLOW_COPY_AND_ASSIGN(State);
      49             :   };
      50             : 
      51             :   // Returns whether we have entered name collection state.
      52   153684198 :   bool IsOpen() const { return !entries_stack_.is_empty(); }
      53             : 
      54             :   // Pushes an enclosing the name of enclosing function onto names stack.
      55             :   void PushEnclosingName(const AstRawString* name);
      56             : 
      57             :   // Pushes an encountered name onto names stack when in collection state.
      58             :   void PushLiteralName(const AstRawString* name);
      59             : 
      60             :   void PushVariableName(const AstRawString* name);
      61             : 
      62             :   // Adds a function to infer name for.
      63     4577158 :   void AddFunction(FunctionLiteral* func_to_infer) {
      64     3934431 :     if (IsOpen()) {
      65             :       funcs_to_infer_.Add(func_to_infer, zone());
      66             :     }
      67      736472 :   }
      68             : 
      69    14474312 :   void RemoveLastFunction() {
      70    14474312 :     if (IsOpen() && !funcs_to_infer_.is_empty()) {
      71      259586 :       funcs_to_infer_.RemoveLast();
      72             :     }
      73    14474312 :   }
      74             : 
      75             :   void RemoveAsyncKeywordFromEnd();
      76             : 
      77             :   // Infers a function name and leaves names collection state.
      78      350663 :   void Infer() {
      79             :     DCHECK(IsOpen());
      80    24626993 :     if (!funcs_to_infer_.is_empty()) {
      81     2897058 :       InferFunctionsNames();
      82             :     }
      83      350663 :   }
      84             : 
      85             :  private:
      86             :   enum NameType {
      87             :     kEnclosingConstructorName,
      88             :     kLiteralName,
      89             :     kVariableName
      90             :   };
      91             :   struct Name {
      92   132676399 :     Name(const AstRawString* name, NameType type) : name(name), type(type) {}
      93             :     const AstRawString* name;
      94             :     NameType type;
      95             :   };
      96             : 
      97   254701220 :   void Enter() { entries_stack_.Add(names_stack_.length(), zone()); }
      98             : 
      99   127350757 :   void Leave() {
     100             :     DCHECK(IsOpen());
     101   254701512 :     names_stack_.Rewind(entries_stack_.RemoveLast());
     102   127350755 :     if (entries_stack_.is_empty()) funcs_to_infer_.Clear();
     103   127350755 :   }
     104             : 
     105             :   Zone* zone() const { return zone_; }
     106             : 
     107             :   // Constructs a full name in dotted notation from gathered names.
     108             :   const AstConsString* MakeNameFromStack();
     109             : 
     110             :   // Performs name inferring for added functions.
     111             :   void InferFunctionsNames();
     112             : 
     113             :   AstValueFactory* ast_value_factory_;
     114             :   ZoneList<int> entries_stack_;
     115             :   ZoneList<Name> names_stack_;
     116             :   ZoneList<FunctionLiteral*> funcs_to_infer_;
     117             :   Zone* zone_;
     118             : 
     119             :   DISALLOW_COPY_AND_ASSIGN(FuncNameInferrer);
     120             : };
     121             : 
     122             : 
     123             : }  // namespace internal
     124             : }  // namespace v8
     125             : 
     126             : #endif  // V8_PARSING_FUNC_NAME_INFERRER_H_