13af6ab5fSopenharmony_ci/* 23af6ab5fSopenharmony_ci * Copyright (c) 2021-2024 Huawei Device Co., Ltd. 33af6ab5fSopenharmony_ci * Licensed under the Apache License, Version 2.0 (the "License"); 43af6ab5fSopenharmony_ci * you may not use this file except in compliance with the License. 53af6ab5fSopenharmony_ci * You may obtain a copy of the License at 63af6ab5fSopenharmony_ci * 73af6ab5fSopenharmony_ci * http://www.apache.org/licenses/LICENSE-2.0 83af6ab5fSopenharmony_ci * 93af6ab5fSopenharmony_ci * Unless required by applicable law or agreed to in writing, software 103af6ab5fSopenharmony_ci * distributed under the License is distributed on an "AS IS" BASIS, 113af6ab5fSopenharmony_ci * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 123af6ab5fSopenharmony_ci * See the License for the specific language governing permissions and 133af6ab5fSopenharmony_ci * limitations under the License. 143af6ab5fSopenharmony_ci */ 153af6ab5fSopenharmony_ci 163af6ab5fSopenharmony_ci// 173af6ab5fSopenharmony_ci// desc: For-of-loop syntax is translated to the while-loop syntax by calling of special method 183af6ab5fSopenharmony_ci// providing predefined 'iterator' interface: 193af6ab5fSopenharmony_ci// for (let x of c) { // c is an object of 'iterable' class 203af6ab5fSopenharmony_ci// <body> 213af6ab5fSopenharmony_ci// } 223af6ab5fSopenharmony_ci// ... 233af6ab5fSopenharmony_ci// let_ci_=_c.$_iterator() 243af6ab5fSopenharmony_ci// let_it_=_ci.next() 253af6ab5fSopenharmony_ci// while_(!it.done)_{ 263af6ab5fSopenharmony_ci// x_=_it.value! 273af6ab5fSopenharmony_ci// <body> 283af6ab5fSopenharmony_ci// it_=_ci.next() 293af6ab5fSopenharmony_ci// } 303af6ab5fSopenharmony_ci// 313af6ab5fSopenharmony_ci 323af6ab5fSopenharmony_ci#include "objectIterator.h" 333af6ab5fSopenharmony_ci 343af6ab5fSopenharmony_ci#include "parser/ETSparser.h" 353af6ab5fSopenharmony_ci#include "compiler/lowering/util.h" 363af6ab5fSopenharmony_ci#include "compiler/lowering/scopesInit/scopesInitPhase.h" 373af6ab5fSopenharmony_ci#include "checker/ETSchecker.h" 383af6ab5fSopenharmony_ci 393af6ab5fSopenharmony_cinamespace ark::es2panda::compiler { 403af6ab5fSopenharmony_ci 413af6ab5fSopenharmony_cistatic constexpr std::size_t const WHILE_LOOP_POSITION = 2U; 423af6ab5fSopenharmony_cistatic constexpr std::size_t const WHILE_LOOP_SIZE = 2U; 433af6ab5fSopenharmony_ci 443af6ab5fSopenharmony_cistd::string_view ObjectIteratorLowering::Name() const 453af6ab5fSopenharmony_ci{ 463af6ab5fSopenharmony_ci static std::string const NAME = "ObjectIteratorLowering"; 473af6ab5fSopenharmony_ci return NAME; 483af6ab5fSopenharmony_ci} 493af6ab5fSopenharmony_ci 503af6ab5fSopenharmony_civoid ObjectIteratorLowering::TransferForOfLoopBody(ir::Statement *const forBody, ir::BlockStatement *const whileBody, 513af6ab5fSopenharmony_ci bool const needCleaning) const noexcept 523af6ab5fSopenharmony_ci{ 533af6ab5fSopenharmony_ci ASSERT(forBody != nullptr && whileBody != nullptr); 543af6ab5fSopenharmony_ci auto &whileStatements = whileBody->Statements(); 553af6ab5fSopenharmony_ci 563af6ab5fSopenharmony_ci // Currently while loop body consists of 2 statements: 'x = it.value!' and 'it = ci.next()' 573af6ab5fSopenharmony_ci // We need to insert the body of original for-of-loop between them, change their parent and 583af6ab5fSopenharmony_ci // probably clean types for expressions and variables for identifier for subsequent re-check. 593af6ab5fSopenharmony_ci if (forBody->IsBlockStatement()) { 603af6ab5fSopenharmony_ci auto &forStatements = forBody->AsBlockStatement()->Statements(); 613af6ab5fSopenharmony_ci std::size_t const forSize = forStatements.size(); 623af6ab5fSopenharmony_ci 633af6ab5fSopenharmony_ci whileStatements.resize(WHILE_LOOP_SIZE + forSize); 643af6ab5fSopenharmony_ci whileStatements[WHILE_LOOP_SIZE + forSize - 1U] = whileStatements[WHILE_LOOP_SIZE - 1U]; 653af6ab5fSopenharmony_ci 663af6ab5fSopenharmony_ci for (std::size_t i = 0U; i < forSize; ++i) { 673af6ab5fSopenharmony_ci auto &statement = forStatements[i]; 683af6ab5fSopenharmony_ci statement->SetParent(whileBody); 693af6ab5fSopenharmony_ci if (needCleaning) { 703af6ab5fSopenharmony_ci // Note: we don't need to clean top-level statement itself because it doesn't have type. 713af6ab5fSopenharmony_ci ClearTypesVariablesAndScopes(statement); 723af6ab5fSopenharmony_ci } 733af6ab5fSopenharmony_ci whileStatements[WHILE_LOOP_SIZE + i - 1U] = statement; 743af6ab5fSopenharmony_ci } 753af6ab5fSopenharmony_ci } else { 763af6ab5fSopenharmony_ci whileStatements.resize(WHILE_LOOP_SIZE + 1U); 773af6ab5fSopenharmony_ci whileStatements[WHILE_LOOP_SIZE] = whileStatements[WHILE_LOOP_SIZE - 1U]; 783af6ab5fSopenharmony_ci 793af6ab5fSopenharmony_ci forBody->SetParent(whileBody); 803af6ab5fSopenharmony_ci if (needCleaning) { 813af6ab5fSopenharmony_ci ClearTypesVariablesAndScopes(forBody); 823af6ab5fSopenharmony_ci } 833af6ab5fSopenharmony_ci whileStatements[WHILE_LOOP_SIZE - 1U] = forBody; 843af6ab5fSopenharmony_ci } 853af6ab5fSopenharmony_ci} 863af6ab5fSopenharmony_ci 873af6ab5fSopenharmony_ciir::Statement *ObjectIteratorLowering::ProcessObjectIterator(parser::ETSParser *parser, checker::ETSChecker *checker, 883af6ab5fSopenharmony_ci varbinder::ETSBinder *varbinder, 893af6ab5fSopenharmony_ci ir::ForOfStatement *forOfStatement) const 903af6ab5fSopenharmony_ci{ 913af6ab5fSopenharmony_ci // Note! We assume that parser, varbinder and checker phases have been already passed correctly, thus the 923af6ab5fSopenharmony_ci // class has required accessible iterator method and all the types and scopes are properly resolved. 933af6ab5fSopenharmony_ci 943af6ab5fSopenharmony_ci auto *const allocator = checker->Allocator(); 953af6ab5fSopenharmony_ci auto statementScope = varbinder::LexicalScope<varbinder::Scope>::Enter(varbinder, NearestScope(forOfStatement)); 963af6ab5fSopenharmony_ci 973af6ab5fSopenharmony_ci ir::Identifier *const iterIdent = Gensym(allocator); 983af6ab5fSopenharmony_ci ir::Identifier *const nextIdent = Gensym(allocator); 993af6ab5fSopenharmony_ci std::string loopVariableName; 1003af6ab5fSopenharmony_ci bool declared = true; 1013af6ab5fSopenharmony_ci 1023af6ab5fSopenharmony_ci // Replace the for-of loop with the while loop using the provided iterator interface 1033af6ab5fSopenharmony_ci std::string whileStatement = "let @@I1 = (@@E2)." + std::string {compiler::Signatures::ITERATOR_METHOD} + "(); "; 1043af6ab5fSopenharmony_ci whileStatement += "let @@I3 = @@I4.next(); "; 1053af6ab5fSopenharmony_ci whileStatement += "while (!@@I5.done) { "; 1063af6ab5fSopenharmony_ci 1073af6ab5fSopenharmony_ci if (auto *const left = forOfStatement->Left(); left->IsVariableDeclaration()) { 1083af6ab5fSopenharmony_ci auto *const declaration = left->AsVariableDeclaration(); 1093af6ab5fSopenharmony_ci whileStatement += 1103af6ab5fSopenharmony_ci declaration->Kind() != ir::VariableDeclaration::VariableDeclarationKind::CONST ? "let " : "const "; 1113af6ab5fSopenharmony_ci loopVariableName = declaration->Declarators().at(0U)->Id()->AsIdentifier()->Name().Mutf8(); 1123af6ab5fSopenharmony_ci } else if (left->IsIdentifier()) { 1133af6ab5fSopenharmony_ci declared = false; 1143af6ab5fSopenharmony_ci loopVariableName = left->AsIdentifier()->Name().Mutf8(); 1153af6ab5fSopenharmony_ci } else { 1163af6ab5fSopenharmony_ci UNREACHABLE(); 1173af6ab5fSopenharmony_ci } 1183af6ab5fSopenharmony_ci 1193af6ab5fSopenharmony_ci whileStatement += loopVariableName + " = @@I6.value!; "; 1203af6ab5fSopenharmony_ci // later on here we will insert the current for-of-loop body. 1213af6ab5fSopenharmony_ci whileStatement += "@@I7 = @@I8.next(); }"; 1223af6ab5fSopenharmony_ci 1233af6ab5fSopenharmony_ci // Parse ArkTS code string and create corresponding AST nodes 1243af6ab5fSopenharmony_ci auto *const loweringResult = parser->CreateFormattedStatement( 1253af6ab5fSopenharmony_ci whileStatement, iterIdent, forOfStatement->Right(), nextIdent, iterIdent->Clone(allocator, nullptr), 1263af6ab5fSopenharmony_ci nextIdent->Clone(allocator, nullptr), nextIdent->Clone(allocator, nullptr), 1273af6ab5fSopenharmony_ci nextIdent->Clone(allocator, nullptr), iterIdent->Clone(allocator, nullptr)); 1283af6ab5fSopenharmony_ci loweringResult->SetParent(forOfStatement->Parent()); 1293af6ab5fSopenharmony_ci 1303af6ab5fSopenharmony_ci TransferForOfLoopBody(forOfStatement->Body(), 1313af6ab5fSopenharmony_ci loweringResult->AsBlockStatement() 1323af6ab5fSopenharmony_ci ->Statements()[WHILE_LOOP_POSITION] 1333af6ab5fSopenharmony_ci ->AsWhileStatement() 1343af6ab5fSopenharmony_ci ->Body() 1353af6ab5fSopenharmony_ci ->AsBlockStatement(), 1363af6ab5fSopenharmony_ci declared); 1373af6ab5fSopenharmony_ci 1383af6ab5fSopenharmony_ci InitScopesPhaseETS::RunExternalNode(loweringResult, varbinder); 1393af6ab5fSopenharmony_ci loweringResult->Check(checker); 1403af6ab5fSopenharmony_ci 1413af6ab5fSopenharmony_ci return loweringResult; 1423af6ab5fSopenharmony_ci} 1433af6ab5fSopenharmony_ci 1443af6ab5fSopenharmony_cibool ObjectIteratorLowering::Perform(public_lib::Context *ctx, parser::Program *program) 1453af6ab5fSopenharmony_ci{ 1463af6ab5fSopenharmony_ci const auto &options = ctx->config->options->CompilerOptions(); 1473af6ab5fSopenharmony_ci if (options.compilationMode == CompilationMode::GEN_STD_LIB) { 1483af6ab5fSopenharmony_ci for (auto &[_, extPrograms] : program->ExternalSources()) { 1493af6ab5fSopenharmony_ci (void)_; 1503af6ab5fSopenharmony_ci for (auto *extProg : extPrograms) { 1513af6ab5fSopenharmony_ci Perform(ctx, extProg); 1523af6ab5fSopenharmony_ci } 1533af6ab5fSopenharmony_ci } 1543af6ab5fSopenharmony_ci } 1553af6ab5fSopenharmony_ci 1563af6ab5fSopenharmony_ci auto *const parser = ctx->parser->AsETSParser(); 1573af6ab5fSopenharmony_ci ASSERT(parser != nullptr); 1583af6ab5fSopenharmony_ci auto *const checker = ctx->checker->AsETSChecker(); 1593af6ab5fSopenharmony_ci ASSERT(checker != nullptr); 1603af6ab5fSopenharmony_ci auto *const varbinder = ctx->checker->VarBinder()->AsETSBinder(); 1613af6ab5fSopenharmony_ci ASSERT(varbinder != nullptr); 1623af6ab5fSopenharmony_ci 1633af6ab5fSopenharmony_ci auto hasIterator = [](checker::Type const *const exprType) -> bool { 1643af6ab5fSopenharmony_ci return exprType != nullptr && 1653af6ab5fSopenharmony_ci ((exprType->IsETSObjectType() && !exprType->IsETSStringType()) || exprType->IsETSTypeParameter()); 1663af6ab5fSopenharmony_ci }; 1673af6ab5fSopenharmony_ci 1683af6ab5fSopenharmony_ci program->Ast()->TransformChildrenRecursively( 1693af6ab5fSopenharmony_ci // clang-format off 1703af6ab5fSopenharmony_ci [this, parser, checker, varbinder, &hasIterator](ir::AstNode *ast) -> ir::AstNode* { 1713af6ab5fSopenharmony_ci // clang-format on 1723af6ab5fSopenharmony_ci if (ast->IsForOfStatement()) { 1733af6ab5fSopenharmony_ci if (auto const *const exprType = ast->AsForOfStatement()->Right()->TsType(); 1743af6ab5fSopenharmony_ci hasIterator(exprType) || (exprType != nullptr && exprType->IsETSUnionType() && 1753af6ab5fSopenharmony_ci exprType->AsETSUnionType()->AllOfConstituentTypes(hasIterator))) { 1763af6ab5fSopenharmony_ci return ProcessObjectIterator(parser, checker, varbinder, ast->AsForOfStatement()); 1773af6ab5fSopenharmony_ci } 1783af6ab5fSopenharmony_ci } 1793af6ab5fSopenharmony_ci return ast; 1803af6ab5fSopenharmony_ci }, 1813af6ab5fSopenharmony_ci Name()); 1823af6ab5fSopenharmony_ci 1833af6ab5fSopenharmony_ci return true; 1843af6ab5fSopenharmony_ci} 1853af6ab5fSopenharmony_ci} // namespace ark::es2panda::compiler 186