v8/src/ast/modules.h - cobalt - Git at Google

 // 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_MODULES_H_
 #define V8_AST_MODULES_H_

 #include "src/parsing/scanner.h"  // Only for Scanner::Location.
 #include "src/zone/zone-containers.h"

 namespace v8 {
 namespace internal {


 class AstRawString;
 class ModuleRequest;
 class SourceTextModuleInfo;
 class SourceTextModuleInfoEntry;
 class PendingCompilationErrorHandler;

 class SourceTextModuleDescriptor : public ZoneObject {
  public:
   explicit SourceTextModuleDescriptor(Zone* zone)
       : module_requests_(zone),
         special_exports_(zone),
         namespace_imports_(zone),
         regular_exports_(zone),
         regular_imports_(zone) {}

   using ImportAssertions =
       ZoneMap<const AstRawString*,
               std::pair<const AstRawString*, Scanner::Location>>;

   // The following Add* methods are high-level convenience functions for use by
   // the parser.

   // import x from "foo.js";
   // import {x} from "foo.js";
   // import {x as y} from "foo.js";
   void AddImport(const AstRawString* import_name,
                  const AstRawString* local_name,
                  const AstRawString* module_request,
                  const ImportAssertions* import_assertions,
                  const Scanner::Location loc,
                  const Scanner::Location specifier_loc, Zone* zone);

   // import * as x from "foo.js";
   void AddStarImport(const AstRawString* local_name,
                      const AstRawString* module_request,
                      const ImportAssertions* import_assertions,
                      const Scanner::Location loc,
                      const Scanner::Location specifier_loc, Zone* zone);

   // import "foo.js";
   // import {} from "foo.js";
   // export {} from "foo.js";  (sic!)
   void AddEmptyImport(const AstRawString* module_request,
                       const ImportAssertions* import_assertions,
                       const Scanner::Location specifier_loc, Zone* zone);

   // export {x};
   // export {x as y};
   // export VariableStatement
   // export Declaration
   // export default ...
   void AddExport(
     const AstRawString* local_name, const AstRawString* export_name,
     const Scanner::Location loc, Zone* zone);

   // export {x} from "foo.js";
   // export {x as y} from "foo.js";
   void AddExport(const AstRawString* export_name,
                  const AstRawString* import_name,
                  const AstRawString* module_request,
                  const ImportAssertions* import_assertions,
                  const Scanner::Location loc,
                  const Scanner::Location specifier_loc, Zone* zone);

   // export * from "foo.js";
   void AddStarExport(const AstRawString* module_request,
                      const ImportAssertions* import_assertions,
                      const Scanner::Location loc,
                      const Scanner::Location specifier_loc, Zone* zone);

   // Check if module is well-formed and report error if not.
   // Also canonicalize indirect exports.
   bool Validate(ModuleScope* module_scope,
                 PendingCompilationErrorHandler* error_handler, Zone* zone);

   struct Entry : public ZoneObject {
     Scanner::Location location;
     const AstRawString* export_name;
     const AstRawString* local_name;
     const AstRawString* import_name;

     // The module_request value records the order in which modules are
     // requested. It also functions as an index into the SourceTextModuleInfo's
     // array of module specifiers and into the Module's array of requested
     // modules.  A negative value means no module request.
     int module_request;

     // Import/export entries that are associated with a MODULE-allocated
     // variable (i.e. regular_imports and regular_exports after Validate) use
     // the cell_index value to encode the location of their cell.  During
     // variable allocation, this will be be copied into the variable's index
     // field.
     // Entries that are not associated with a MODULE-allocated variable have
     // GetCellIndexKind(cell_index) == kInvalid.
     int cell_index;

     // TODO(neis): Remove local_name component?
     explicit Entry(Scanner::Location loc)
         : location(loc),
           export_name(nullptr),
           local_name(nullptr),
           import_name(nullptr),
           module_request(-1),
           cell_index(0) {}

     template <typename LocalIsolate>
     Handle<SourceTextModuleInfoEntry> Serialize(LocalIsolate* isolate) const;
   };

   enum CellIndexKind { kInvalid, kExport, kImport };
   static CellIndexKind GetCellIndexKind(int cell_index);

   class AstModuleRequest : public ZoneObject {
    public:
     // TODO(v8:10958): Consider storing module request location here
     // instead of using separate ModuleRequestLocation struct.
     AstModuleRequest(const AstRawString* specifier,
                      const ImportAssertions* import_assertions)
         : specifier_(specifier), import_assertions_(import_assertions) {}

     template <typename LocalIsolate>
     Handle<v8::internal::ModuleRequest> Serialize(LocalIsolate* isolate) const;

     const AstRawString* specifier() const { return specifier_; }
     const ImportAssertions* import_assertions() const {
       return import_assertions_;
     }

    private:
     const AstRawString* specifier_;
     const ImportAssertions* import_assertions_;
   };

   struct ModuleRequestLocation {
     // The index at which we will place the request in SourceTextModuleInfo's
     // module_requests FixedArray.
     int index;

     // The JS source code position of the request, used for reporting errors.
     int position;

     ModuleRequestLocation(int index, int position)
         : index(index), position(position) {}
   };

   // Custom content-based comparer for the below maps, to keep them stable
   // across parses.
   struct V8_EXPORT_PRIVATE AstRawStringComparer {
     bool operator()(const AstRawString* lhs, const AstRawString* rhs) const;
     static int ThreeWayCompare(const AstRawString* lhs,
                                const AstRawString* rhs);
   };

   struct V8_EXPORT_PRIVATE ModuleRequestComparer {
     bool operator()(const AstModuleRequest* lhs,
                     const AstModuleRequest* rhs) const;
   };

   using ModuleRequestMap =
       ZoneMap<const AstModuleRequest*, ModuleRequestLocation,
               ModuleRequestComparer>;
   using RegularExportMap =
       ZoneMultimap<const AstRawString*, Entry*, AstRawStringComparer>;
   using RegularImportMap =
       ZoneMap<const AstRawString*, Entry*, AstRawStringComparer>;

   // Module requests.
   const ModuleRequestMap& module_requests() const { return module_requests_; }

   // Namespace imports.
   const ZoneVector<const Entry*>& namespace_imports() const {
     return namespace_imports_;
   }

   // All the remaining imports, indexed by local name.
   const RegularImportMap& regular_imports() const { return regular_imports_; }

   // Star exports and explicitly indirect exports.
   const ZoneVector<const Entry*>& special_exports() const {
     return special_exports_;
   }

   // All the remaining exports, indexed by local name.
   // After canonicalization (see Validate), these are exactly the local exports.
   const RegularExportMap& regular_exports() const { return regular_exports_; }

   void AddRegularExport(Entry* entry) {
     DCHECK_NOT_NULL(entry->export_name);
     DCHECK_NOT_NULL(entry->local_name);
     DCHECK_NULL(entry->import_name);
     DCHECK_LT(entry->module_request, 0);
     regular_exports_.insert(std::make_pair(entry->local_name, entry));
   }

   void AddSpecialExport(const Entry* entry, Zone* zone) {
     DCHECK_NULL(entry->local_name);
     DCHECK_LE(0, entry->module_request);
     special_exports_.push_back(entry);
   }

   void AddRegularImport(Entry* entry) {
     DCHECK_NOT_NULL(entry->import_name);
     DCHECK_NOT_NULL(entry->local_name);
     DCHECK_NULL(entry->export_name);
     DCHECK_LE(0, entry->module_request);
     regular_imports_.insert(std::make_pair(entry->local_name, entry));
     // We don't care if there's already an entry for this local name, as in that
     // case we will report an error when declaring the variable.
   }

   void AddNamespaceImport(const Entry* entry, Zone* zone) {
     DCHECK_NULL(entry->import_name);
     DCHECK_NULL(entry->export_name);
     DCHECK_NOT_NULL(entry->local_name);
     DCHECK_LE(0, entry->module_request);
     namespace_imports_.push_back(entry);
   }

   template <typename LocalIsolate>
   Handle<FixedArray> SerializeRegularExports(LocalIsolate* isolate,
                                              Zone* zone) const;

  private:
   ModuleRequestMap module_requests_;
   ZoneVector<const Entry*> special_exports_;
   ZoneVector<const Entry*> namespace_imports_;
   RegularExportMap regular_exports_;
   RegularImportMap regular_imports_;

   // If there are multiple export entries with the same export name, return the
   // last of them (in source order).  Otherwise return nullptr.
   const Entry* FindDuplicateExport(Zone* zone) const;

   // Find any implicitly indirect exports and make them explicit.
   //
   // An explicitly indirect export is an export entry arising from an export
   // statement of the following form:
   //   export {a as c} from "X";
   // An implicitly indirect export corresponds to
   //   export {b as c};
   // in the presence of an import statement of the form
   //   import {a as b} from "X";
   // This function finds such implicitly indirect export entries and rewrites
   // them by filling in the import name and module request, as well as nulling
   // out the local name.  Effectively, it turns
   //   import {a as b} from "X"; export {b as c};
   // into:
   //   import {a as b} from "X"; export {a as c} from "X";
   // (The import entry is never deleted.)
   void MakeIndirectExportsExplicit(Zone* zone);

   // Assign a cell_index of -1,-2,... to regular imports.
   // Assign a cell_index of +1,+2,... to regular (local) exports.
   // Assign a cell_index of 0 to anything else.
   void AssignCellIndices();

   int AddModuleRequest(const AstRawString* specifier,
                        const ImportAssertions* import_assertions,
                        Scanner::Location specifier_loc, Zone* zone) {
     DCHECK_NOT_NULL(specifier);
     int module_requests_count = static_cast<int>(module_requests_.size());
     auto it = module_requests_
                   .insert(std::make_pair(
                       zone->New<AstModuleRequest>(specifier, import_assertions),
                       ModuleRequestLocation(module_requests_count,
                                             specifier_loc.beg_pos)))
                   .first;
     return it->second.index;
   }
 };

 }  // namespace internal
 }  // namespace v8

 #endif  // V8_AST_MODULES_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_MODULES_H_
	#define V8_AST_MODULES_H_

	#include "src/parsing/scanner.h" // Only for Scanner::Location.
	#include "src/zone/zone-containers.h"

	namespace v8 {
	namespace internal {


	class AstRawString;
	class ModuleRequest;
	class SourceTextModuleInfo;
	class SourceTextModuleInfoEntry;
	class PendingCompilationErrorHandler;

	class SourceTextModuleDescriptor : public ZoneObject {
	public:
	explicit SourceTextModuleDescriptor(Zone* zone)
	: module_requests_(zone),
	special_exports_(zone),
	namespace_imports_(zone),
	regular_exports_(zone),
	regular_imports_(zone) {}

	using ImportAssertions =
	ZoneMap<const AstRawString*,
	std::pair<const AstRawString*, Scanner::Location>>;

	// The following Add* methods are high-level convenience functions for use by
	// the parser.

	// import x from "foo.js";
	// import {x} from "foo.js";
	// import {x as y} from "foo.js";
	void AddImport(const AstRawString* import_name,
	const AstRawString* local_name,
	const AstRawString* module_request,
	const ImportAssertions* import_assertions,
	const Scanner::Location loc,
	const Scanner::Location specifier_loc, Zone* zone);

	// import * as x from "foo.js";
	void AddStarImport(const AstRawString* local_name,
	const AstRawString* module_request,
	const ImportAssertions* import_assertions,
	const Scanner::Location loc,
	const Scanner::Location specifier_loc, Zone* zone);

	// import "foo.js";
	// import {} from "foo.js";
	// export {} from "foo.js"; (sic!)
	void AddEmptyImport(const AstRawString* module_request,
	const ImportAssertions* import_assertions,
	const Scanner::Location specifier_loc, Zone* zone);

	// export {x};
	// export {x as y};
	// export VariableStatement
	// export Declaration
	// export default ...
	void AddExport(
	const AstRawString* local_name, const AstRawString* export_name,
	const Scanner::Location loc, Zone* zone);

	// export {x} from "foo.js";
	// export {x as y} from "foo.js";
	void AddExport(const AstRawString* export_name,
	const AstRawString* import_name,
	const AstRawString* module_request,
	const ImportAssertions* import_assertions,
	const Scanner::Location loc,
	const Scanner::Location specifier_loc, Zone* zone);

	// export * from "foo.js";
	void AddStarExport(const AstRawString* module_request,
	const ImportAssertions* import_assertions,
	const Scanner::Location loc,
	const Scanner::Location specifier_loc, Zone* zone);

	// Check if module is well-formed and report error if not.
	// Also canonicalize indirect exports.
	bool Validate(ModuleScope* module_scope,
	PendingCompilationErrorHandler* error_handler, Zone* zone);

	struct Entry : public ZoneObject {
	Scanner::Location location;
	const AstRawString* export_name;
	const AstRawString* local_name;
	const AstRawString* import_name;

	// The module_request value records the order in which modules are
	// requested. It also functions as an index into the SourceTextModuleInfo's
	// array of module specifiers and into the Module's array of requested
	// modules. A negative value means no module request.
	int module_request;

	// Import/export entries that are associated with a MODULE-allocated
	// variable (i.e. regular_imports and regular_exports after Validate) use
	// the cell_index value to encode the location of their cell. During
	// variable allocation, this will be be copied into the variable's index
	// field.
	// Entries that are not associated with a MODULE-allocated variable have
	// GetCellIndexKind(cell_index) == kInvalid.
	int cell_index;

	// TODO(neis): Remove local_name component?
	explicit Entry(Scanner::Location loc)
	: location(loc),
	export_name(nullptr),
	local_name(nullptr),
	import_name(nullptr),
	module_request(-1),
	cell_index(0) {}

	template <typename LocalIsolate>
	Handle<SourceTextModuleInfoEntry> Serialize(LocalIsolate* isolate) const;
	};

	enum CellIndexKind { kInvalid, kExport, kImport };
	static CellIndexKind GetCellIndexKind(int cell_index);

	class AstModuleRequest : public ZoneObject {
	public:
	// TODO(v8:10958): Consider storing module request location here
	// instead of using separate ModuleRequestLocation struct.
	AstModuleRequest(const AstRawString* specifier,
	const ImportAssertions* import_assertions)
	: specifier_(specifier), import_assertions_(import_assertions) {}

	template <typename LocalIsolate>
	Handle<v8::internal::ModuleRequest> Serialize(LocalIsolate* isolate) const;

	const AstRawString* specifier() const { return specifier_; }
	const ImportAssertions* import_assertions() const {
	return import_assertions_;
	}

	private:
	const AstRawString* specifier_;
	const ImportAssertions* import_assertions_;
	};

	struct ModuleRequestLocation {
	// The index at which we will place the request in SourceTextModuleInfo's
	// module_requests FixedArray.
	int index;

	// The JS source code position of the request, used for reporting errors.
	int position;

	ModuleRequestLocation(int index, int position)
	: index(index), position(position) {}
	};

	// Custom content-based comparer for the below maps, to keep them stable
	// across parses.
	struct V8_EXPORT_PRIVATE AstRawStringComparer {
	bool operator()(const AstRawString* lhs, const AstRawString* rhs) const;
	static int ThreeWayCompare(const AstRawString* lhs,
	const AstRawString* rhs);
	};

	struct V8_EXPORT_PRIVATE ModuleRequestComparer {
	bool operator()(const AstModuleRequest* lhs,
	const AstModuleRequest* rhs) const;
	};

	using ModuleRequestMap =
	ZoneMap<const AstModuleRequest*, ModuleRequestLocation,
	ModuleRequestComparer>;
	using RegularExportMap =
	ZoneMultimap<const AstRawString, Entry, AstRawStringComparer>;
	using RegularImportMap =
	ZoneMap<const AstRawString, Entry, AstRawStringComparer>;

	// Module requests.
	const ModuleRequestMap& module_requests() const { return module_requests_; }

	// Namespace imports.
	const ZoneVector<const Entry*>& namespace_imports() const {
	return namespace_imports_;
	}

	// All the remaining imports, indexed by local name.
	const RegularImportMap& regular_imports() const { return regular_imports_; }

	// Star exports and explicitly indirect exports.
	const ZoneVector<const Entry*>& special_exports() const {
	return special_exports_;
	}

	// All the remaining exports, indexed by local name.
	// After canonicalization (see Validate), these are exactly the local exports.
	const RegularExportMap& regular_exports() const { return regular_exports_; }

	void AddRegularExport(Entry* entry) {
	DCHECK_NOT_NULL(entry->export_name);
	DCHECK_NOT_NULL(entry->local_name);
	DCHECK_NULL(entry->import_name);
	DCHECK_LT(entry->module_request, 0);
	regular_exports_.insert(std::make_pair(entry->local_name, entry));
	}

	void AddSpecialExport(const Entry* entry, Zone* zone) {
	DCHECK_NULL(entry->local_name);
	DCHECK_LE(0, entry->module_request);
	special_exports_.push_back(entry);
	}

	void AddRegularImport(Entry* entry) {
	DCHECK_NOT_NULL(entry->import_name);
	DCHECK_NOT_NULL(entry->local_name);
	DCHECK_NULL(entry->export_name);
	DCHECK_LE(0, entry->module_request);
	regular_imports_.insert(std::make_pair(entry->local_name, entry));
	// We don't care if there's already an entry for this local name, as in that
	// case we will report an error when declaring the variable.
	}

	void AddNamespaceImport(const Entry* entry, Zone* zone) {
	DCHECK_NULL(entry->import_name);
	DCHECK_NULL(entry->export_name);
	DCHECK_NOT_NULL(entry->local_name);
	DCHECK_LE(0, entry->module_request);
	namespace_imports_.push_back(entry);
	}

	template <typename LocalIsolate>
	Handle<FixedArray> SerializeRegularExports(LocalIsolate* isolate,
	Zone* zone) const;

	private:
	ModuleRequestMap module_requests_;
	ZoneVector<const Entry*> special_exports_;
	ZoneVector<const Entry*> namespace_imports_;
	RegularExportMap regular_exports_;
	RegularImportMap regular_imports_;

	// If there are multiple export entries with the same export name, return the
	// last of them (in source order). Otherwise return nullptr.
	const Entry* FindDuplicateExport(Zone* zone) const;

	// Find any implicitly indirect exports and make them explicit.
	//
	// An explicitly indirect export is an export entry arising from an export
	// statement of the following form:
	// export {a as c} from "X";
	// An implicitly indirect export corresponds to
	// export {b as c};
	// in the presence of an import statement of the form
	// import {a as b} from "X";
	// This function finds such implicitly indirect export entries and rewrites
	// them by filling in the import name and module request, as well as nulling
	// out the local name. Effectively, it turns
	// import {a as b} from "X"; export {b as c};
	// into:
	// import {a as b} from "X"; export {a as c} from "X";
	// (The import entry is never deleted.)
	void MakeIndirectExportsExplicit(Zone* zone);

	// Assign a cell_index of -1,-2,... to regular imports.
	// Assign a cell_index of +1,+2,... to regular (local) exports.
	// Assign a cell_index of 0 to anything else.
	void AssignCellIndices();

	int AddModuleRequest(const AstRawString* specifier,
	const ImportAssertions* import_assertions,
	Scanner::Location specifier_loc, Zone* zone) {
	DCHECK_NOT_NULL(specifier);
	int module_requests_count = static_cast<int>(module_requests_.size());
	auto it = module_requests_
	.insert(std::make_pair(
	zone->New<AstModuleRequest>(specifier, import_assertions),
	ModuleRequestLocation(module_requests_count,
	specifier_loc.beg_pos)))
	.first;
	return it->second.index;
	}
	};

	} // namespace internal
	} // namespace v8

	#endif // V8_AST_MODULES_H_