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      1 // Copyright 2012 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_AST_MODULES_H_
      6 #define V8_AST_MODULES_H_
      7 
      8 #include "src/zone.h"
      9 
     10 namespace v8 {
     11 namespace internal {
     12 
     13 
     14 class AstRawString;
     15 
     16 
     17 class ModuleDescriptor : public ZoneObject {
     18  public:
     19   // ---------------------------------------------------------------------------
     20   // Factory methods.
     21 
     22   static ModuleDescriptor* New(Zone* zone) {
     23     return new (zone) ModuleDescriptor(zone);
     24   }
     25 
     26   // ---------------------------------------------------------------------------
     27   // Mutators.
     28 
     29   // Add a name to the list of exports. If it already exists, that's an error.
     30   void AddLocalExport(const AstRawString* export_name,
     31                       const AstRawString* local_name, Zone* zone, bool* ok);
     32 
     33   // Add module_specifier to the list of requested modules,
     34   // if not already present.
     35   void AddModuleRequest(const AstRawString* module_specifier, Zone* zone);
     36 
     37   // Assign an index.
     38   void Allocate(int index) {
     39     DCHECK_EQ(-1, index_);
     40     index_ = index;
     41   }
     42 
     43   // ---------------------------------------------------------------------------
     44   // Accessors.
     45 
     46   int Length() {
     47     ZoneHashMap* exports = exports_;
     48     return exports ? exports->occupancy() : 0;
     49   }
     50 
     51   // The context slot in the hosting script context pointing to this module.
     52   int Index() {
     53     return index_;
     54   }
     55 
     56   const AstRawString* LookupLocalExport(const AstRawString* export_name,
     57                                         Zone* zone);
     58 
     59   const ZoneList<const AstRawString*>& requested_modules() const {
     60     return requested_modules_;
     61   }
     62 
     63   // ---------------------------------------------------------------------------
     64   // Iterators.
     65 
     66   // Use like:
     67   //   for (auto it = descriptor->iterator(); !it.done(); it.Advance()) {
     68   //     ... it.name() ...
     69   //   }
     70   class Iterator {
     71    public:
     72     bool done() const { return entry_ == NULL; }
     73     const AstRawString* export_name() const {
     74       DCHECK(!done());
     75       return static_cast<const AstRawString*>(entry_->key);
     76     }
     77     const AstRawString* local_name() const {
     78       DCHECK(!done());
     79       return static_cast<const AstRawString*>(entry_->value);
     80     }
     81     void Advance() { entry_ = exports_->Next(entry_); }
     82 
     83    private:
     84     friend class ModuleDescriptor;
     85     explicit Iterator(const ZoneHashMap* exports)
     86         : exports_(exports), entry_(exports ? exports->Start() : NULL) {}
     87 
     88     const ZoneHashMap* exports_;
     89     ZoneHashMap::Entry* entry_;
     90   };
     91 
     92   Iterator iterator() const { return Iterator(this->exports_); }
     93 
     94   // ---------------------------------------------------------------------------
     95   // Implementation.
     96  private:
     97   explicit ModuleDescriptor(Zone* zone)
     98       : exports_(NULL), requested_modules_(1, zone), index_(-1) {}
     99 
    100   ZoneHashMap* exports_;   // Module exports and their types (allocated lazily)
    101   ZoneList<const AstRawString*> requested_modules_;
    102   int index_;
    103 };
    104 
    105 }  // namespace internal
    106 }  // namespace v8
    107 
    108 #endif  // V8_AST_MODULES_H_
    109