// 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. #include "src/ast/modules.h" #include "src/ast/ast-value-factory.h" #include "src/ast/scopes.h" #include "src/objects-inl.h" #include "src/objects/module-inl.h" #include "src/pending-compilation-error-handler.h" namespace v8 { namespace internal { bool ModuleDescriptor::AstRawStringComparer::operator()( const AstRawString* lhs, const AstRawString* rhs) const { // Fast path for equal pointers: a pointer is not strictly less than itself. if (lhs == rhs) return false; // Order by contents (ordering by hash is unstable across runs). if (lhs->is_one_byte() != rhs->is_one_byte()) { return lhs->is_one_byte(); } if (lhs->byte_length() != rhs->byte_length()) { return lhs->byte_length() < rhs->byte_length(); } return memcmp(lhs->raw_data(), rhs->raw_data(), lhs->byte_length()) < 0; } void ModuleDescriptor::AddImport(const AstRawString* import_name, const AstRawString* local_name, const AstRawString* module_request, const Scanner::Location loc, const Scanner::Location specifier_loc, Zone* zone) { Entry* entry = new (zone) Entry(loc); entry->local_name = local_name; entry->import_name = import_name; entry->module_request = AddModuleRequest(module_request, specifier_loc); AddRegularImport(entry); } void ModuleDescriptor::AddStarImport(const AstRawString* local_name, const AstRawString* module_request, const Scanner::Location loc, const Scanner::Location specifier_loc, Zone* zone) { Entry* entry = new (zone) Entry(loc); entry->local_name = local_name; entry->module_request = AddModuleRequest(module_request, specifier_loc); AddNamespaceImport(entry, zone); } void ModuleDescriptor::AddEmptyImport(const AstRawString* module_request, const Scanner::Location specifier_loc) { AddModuleRequest(module_request, specifier_loc); } void ModuleDescriptor::AddExport( const AstRawString* local_name, const AstRawString* export_name, Scanner::Location loc, Zone* zone) { Entry* entry = new (zone) Entry(loc); entry->export_name = export_name; entry->local_name = local_name; AddRegularExport(entry); } void ModuleDescriptor::AddExport(const AstRawString* import_name, const AstRawString* export_name, const AstRawString* module_request, const Scanner::Location loc, const Scanner::Location specifier_loc, Zone* zone) { DCHECK_NOT_NULL(import_name); DCHECK_NOT_NULL(export_name); Entry* entry = new (zone) Entry(loc); entry->export_name = export_name; entry->import_name = import_name; entry->module_request = AddModuleRequest(module_request, specifier_loc); AddSpecialExport(entry, zone); } void ModuleDescriptor::AddStarExport(const AstRawString* module_request, const Scanner::Location loc, const Scanner::Location specifier_loc, Zone* zone) { Entry* entry = new (zone) Entry(loc); entry->module_request = AddModuleRequest(module_request, specifier_loc); AddSpecialExport(entry, zone); } namespace { Handle<Object> ToStringOrUndefined(Isolate* isolate, const AstRawString* s) { return (s == nullptr) ? Handle<Object>::cast(isolate->factory()->undefined_value()) : Handle<Object>::cast(s->string()); } } // namespace Handle<ModuleInfoEntry> ModuleDescriptor::Entry::Serialize( Isolate* isolate) const { CHECK(Smi::IsValid(module_request)); // TODO(neis): Check earlier? return ModuleInfoEntry::New( isolate, ToStringOrUndefined(isolate, export_name), ToStringOrUndefined(isolate, local_name), ToStringOrUndefined(isolate, import_name), module_request, cell_index, location.beg_pos, location.end_pos); } Handle<FixedArray> ModuleDescriptor::SerializeRegularExports(Isolate* isolate, Zone* zone) const { // We serialize regular exports in a way that lets us later iterate over their // local names and for each local name immediately access all its export // names. (Regular exports have neither import name nor module request.) ZoneVector<Handle<Object>> data( ModuleInfo::kRegularExportLength * regular_exports_.size(), zone); int index = 0; for (auto it = regular_exports_.begin(); it != regular_exports_.end();) { // Find out how many export names this local name has. auto next = it; int count = 0; do { DCHECK_EQ(it->second->local_name, next->second->local_name); DCHECK_EQ(it->second->cell_index, next->second->cell_index); ++next; ++count; } while (next != regular_exports_.end() && next->first == it->first); Handle<FixedArray> export_names = isolate->factory()->NewFixedArray(count); data[index + ModuleInfo::kRegularExportLocalNameOffset] = it->second->local_name->string(); data[index + ModuleInfo::kRegularExportCellIndexOffset] = handle(Smi::FromInt(it->second->cell_index), isolate); data[index + ModuleInfo::kRegularExportExportNamesOffset] = export_names; index += ModuleInfo::kRegularExportLength; // Collect the export names. int i = 0; for (; it != next; ++it) { export_names->set(i++, *it->second->export_name->string()); } DCHECK_EQ(i, count); // Continue with the next distinct key. DCHECK(it == next); } DCHECK_LE(index, static_cast<int>(data.size())); data.resize(index); // We cannot create the FixedArray earlier because we only now know the // precise size. Handle<FixedArray> result = isolate->factory()->NewFixedArray(index); for (int i = 0; i < index; ++i) { result->set(i, *data[i]); } return result; } void ModuleDescriptor::MakeIndirectExportsExplicit(Zone* zone) { for (auto it = regular_exports_.begin(); it != regular_exports_.end();) { Entry* entry = it->second; DCHECK_NOT_NULL(entry->local_name); auto import = regular_imports_.find(entry->local_name); if (import != regular_imports_.end()) { // Found an indirect export. Patch export entry and move it from regular // to special. DCHECK_NULL(entry->import_name); DCHECK_LT(entry->module_request, 0); DCHECK_NOT_NULL(import->second->import_name); DCHECK_LE(0, import->second->module_request); DCHECK_LT(import->second->module_request, static_cast<int>(module_requests_.size())); entry->import_name = import->second->import_name; entry->module_request = import->second->module_request; // Hack: When the indirect export cannot be resolved, we want the error // message to point at the import statement, not at the export statement. // Therefore we overwrite [entry]'s location here. Note that Validate() // has already checked for duplicate exports, so it's guaranteed that we // won't need to report any error pointing at the (now lost) export // location. entry->location = import->second->location; entry->local_name = nullptr; AddSpecialExport(entry, zone); it = regular_exports_.erase(it); } else { it++; } } } ModuleDescriptor::CellIndexKind ModuleDescriptor::GetCellIndexKind( int cell_index) { if (cell_index > 0) return kExport; if (cell_index < 0) return kImport; return kInvalid; } void ModuleDescriptor::AssignCellIndices() { int export_index = 1; for (auto it = regular_exports_.begin(); it != regular_exports_.end();) { auto current_key = it->first; // This local name may be exported under multiple export names. Assign the // same index to each such entry. do { Entry* entry = it->second; DCHECK_NOT_NULL(entry->local_name); DCHECK_NULL(entry->import_name); DCHECK_LT(entry->module_request, 0); DCHECK_EQ(entry->cell_index, 0); entry->cell_index = export_index; it++; } while (it != regular_exports_.end() && it->first == current_key); export_index++; } int import_index = -1; for (const auto& elem : regular_imports_) { Entry* entry = elem.second; DCHECK_NOT_NULL(entry->local_name); DCHECK_NOT_NULL(entry->import_name); DCHECK_LE(0, entry->module_request); DCHECK_EQ(entry->cell_index, 0); entry->cell_index = import_index; import_index--; } } namespace { const ModuleDescriptor::Entry* BetterDuplicate( const ModuleDescriptor::Entry* candidate, ZoneMap<const AstRawString*, const ModuleDescriptor::Entry*>& export_names, const ModuleDescriptor::Entry* current_duplicate) { DCHECK_NOT_NULL(candidate->export_name); DCHECK(candidate->location.IsValid()); auto insert_result = export_names.insert(std::make_pair(candidate->export_name, candidate)); if (insert_result.second) return current_duplicate; if (current_duplicate == nullptr) { current_duplicate = insert_result.first->second; } return (candidate->location.beg_pos > current_duplicate->location.beg_pos) ? candidate : current_duplicate; } } // namespace const ModuleDescriptor::Entry* ModuleDescriptor::FindDuplicateExport( Zone* zone) const { const ModuleDescriptor::Entry* duplicate = nullptr; ZoneMap<const AstRawString*, const ModuleDescriptor::Entry*> export_names( zone); for (const auto& elem : regular_exports_) { duplicate = BetterDuplicate(elem.second, export_names, duplicate); } for (auto entry : special_exports_) { if (entry->export_name == nullptr) continue; // Star export. duplicate = BetterDuplicate(entry, export_names, duplicate); } return duplicate; } bool ModuleDescriptor::Validate(ModuleScope* module_scope, PendingCompilationErrorHandler* error_handler, Zone* zone) { DCHECK_EQ(this, module_scope->module()); DCHECK_NOT_NULL(error_handler); // Report error iff there are duplicate exports. { const Entry* entry = FindDuplicateExport(zone); if (entry != nullptr) { error_handler->ReportMessageAt( entry->location.beg_pos, entry->location.end_pos, MessageTemplate::kDuplicateExport, entry->export_name); return false; } } // Report error iff there are exports of non-existent local names. for (const auto& elem : regular_exports_) { const Entry* entry = elem.second; DCHECK_NOT_NULL(entry->local_name); if (module_scope->LookupLocal(entry->local_name) == nullptr) { error_handler->ReportMessageAt( entry->location.beg_pos, entry->location.end_pos, MessageTemplate::kModuleExportUndefined, entry->local_name); return false; } } MakeIndirectExportsExplicit(zone); AssignCellIndices(); return true; } } // namespace internal } // namespace v8