diff --git a/deps/v8/src/parser.cc b/deps/v8/src/parser.cc index 6c941daa978..0cf621bb501 100644 --- a/deps/v8/src/parser.cc +++ b/deps/v8/src/parser.cc @@ -2846,29 +2846,33 @@ Statement* Parser::DesugarLetBindingsInForStatement( // // We rewrite a for statement of the form // - // for (let x = i; cond; next) body + // labels: for (let x = i; cond; next) body // // into // // { - // let x = i; - // temp_x = x; - // flag = 1; - // for (;;) { - // let x = temp_x; - // if (flag == 1) { - // flag = 0; - // } else { - // next; - // } + // let x = i; + // temp_x = x; + // first = 1; + // outer: for (;;) { + // let x = temp_x; + // if (first == 1) { + // first = 0; + // } else { + // next; + // } + // flag = 1; + // labels: for (; flag == 1; flag = 0, temp_x = x) { // if (cond) { - // + // body // } else { - // break; + // break outer; // } - // b - // temp_x = x; - // } + // } + // if (flag == 1) { + // break; + // } + // } // } DCHECK(names->length() > 0); @@ -2896,24 +2900,33 @@ Statement* Parser::DesugarLetBindingsInForStatement( temps.Add(temp, zone()); } - Variable* flag = scope_->DeclarationScope()->NewTemporary(temp_name); - // Make statement: flag = 1. - { - VariableProxy* flag_proxy = factory()->NewVariableProxy(flag); + Variable* first = NULL; + // Make statement: first = 1. + if (next) { + first = scope_->DeclarationScope()->NewTemporary(temp_name); + VariableProxy* first_proxy = factory()->NewVariableProxy(first); Expression* const1 = factory()->NewSmiLiteral(1, RelocInfo::kNoPosition); Assignment* assignment = factory()->NewAssignment( - Token::ASSIGN, flag_proxy, const1, RelocInfo::kNoPosition); - Statement* assignment_statement = factory()->NewExpressionStatement( - assignment, RelocInfo::kNoPosition); + Token::ASSIGN, first_proxy, const1, RelocInfo::kNoPosition); + Statement* assignment_statement = + factory()->NewExpressionStatement(assignment, RelocInfo::kNoPosition); outer_block->AddStatement(assignment_statement, zone()); } - outer_block->AddStatement(loop, zone()); + // Make statement: outer: for (;;) + // Note that we don't actually create the label, or set this loop up as an + // explicit break target, instead handing it directly to those nodes that + // need to know about it. This should be safe because we don't run any code + // in this function that looks up break targets. + ForStatement* outer_loop = + factory()->NewForStatement(NULL, RelocInfo::kNoPosition); + outer_block->AddStatement(outer_loop, zone()); + outer_block->set_scope(for_scope); scope_ = inner_scope; - Block* inner_block = factory()->NewBlock(NULL, 2 * names->length() + 3, - false, RelocInfo::kNoPosition); + Block* inner_block = factory()->NewBlock(NULL, names->length() + 4, false, + RelocInfo::kNoPosition); int pos = scanner()->location().beg_pos; ZoneList inner_vars(names->length(), zone()); @@ -2935,61 +2948,118 @@ Statement* Parser::DesugarLetBindingsInForStatement( inner_block->AddStatement(assignment_statement, zone()); } - // Make statement: if (flag == 1) { flag = 0; } else { next; }. + // Make statement: if (first == 1) { first = 0; } else { next; } if (next) { + DCHECK(first); Expression* compare = NULL; - // Make compare expresion: flag == 1. + // Make compare expression: first == 1. { Expression* const1 = factory()->NewSmiLiteral(1, RelocInfo::kNoPosition); - VariableProxy* flag_proxy = factory()->NewVariableProxy(flag); - compare = factory()->NewCompareOperation( - Token::EQ, flag_proxy, const1, pos); + VariableProxy* first_proxy = factory()->NewVariableProxy(first); + compare = + factory()->NewCompareOperation(Token::EQ, first_proxy, const1, pos); } - Statement* clear_flag = NULL; - // Make statement: flag = 0. + Statement* clear_first = NULL; + // Make statement: first = 0. { - VariableProxy* flag_proxy = factory()->NewVariableProxy(flag); + VariableProxy* first_proxy = factory()->NewVariableProxy(first); Expression* const0 = factory()->NewSmiLiteral(0, RelocInfo::kNoPosition); Assignment* assignment = factory()->NewAssignment( - Token::ASSIGN, flag_proxy, const0, RelocInfo::kNoPosition); - clear_flag = factory()->NewExpressionStatement(assignment, pos); + Token::ASSIGN, first_proxy, const0, RelocInfo::kNoPosition); + clear_first = + factory()->NewExpressionStatement(assignment, RelocInfo::kNoPosition); } - Statement* clear_flag_or_next = factory()->NewIfStatement( - compare, clear_flag, next, RelocInfo::kNoPosition); - inner_block->AddStatement(clear_flag_or_next, zone()); + Statement* clear_first_or_next = factory()->NewIfStatement( + compare, clear_first, next, RelocInfo::kNoPosition); + inner_block->AddStatement(clear_first_or_next, zone()); } + Variable* flag = scope_->DeclarationScope()->NewTemporary(temp_name); + // Make statement: flag = 1. + { + VariableProxy* flag_proxy = factory()->NewVariableProxy(flag); + Expression* const1 = factory()->NewSmiLiteral(1, RelocInfo::kNoPosition); + Assignment* assignment = factory()->NewAssignment( + Token::ASSIGN, flag_proxy, const1, RelocInfo::kNoPosition); + Statement* assignment_statement = + factory()->NewExpressionStatement(assignment, RelocInfo::kNoPosition); + inner_block->AddStatement(assignment_statement, zone()); + } + + // Make cond expression for main loop: flag == 1. + Expression* flag_cond = NULL; + { + Expression* const1 = factory()->NewSmiLiteral(1, RelocInfo::kNoPosition); + VariableProxy* flag_proxy = factory()->NewVariableProxy(flag); + flag_cond = + factory()->NewCompareOperation(Token::EQ, flag_proxy, const1, pos); + } - // Make statement: if (cond) { } else { break; }. + // Create chain of expressions "flag = 0, temp_x = x, ..." + Statement* compound_next_statement = NULL; + { + Expression* compound_next = NULL; + // Make expression: flag = 0. + { + VariableProxy* flag_proxy = factory()->NewVariableProxy(flag); + Expression* const0 = factory()->NewSmiLiteral(0, RelocInfo::kNoPosition); + compound_next = factory()->NewAssignment(Token::ASSIGN, flag_proxy, + const0, RelocInfo::kNoPosition); + } + + // Make the comma-separated list of temp_x = x assignments. + for (int i = 0; i < names->length(); i++) { + VariableProxy* temp_proxy = factory()->NewVariableProxy(temps.at(i)); + VariableProxy* proxy = factory()->NewVariableProxy(inner_vars.at(i), pos); + Assignment* assignment = factory()->NewAssignment( + Token::ASSIGN, temp_proxy, proxy, RelocInfo::kNoPosition); + compound_next = factory()->NewBinaryOperation( + Token::COMMA, compound_next, assignment, RelocInfo::kNoPosition); + } + + compound_next_statement = factory()->NewExpressionStatement( + compound_next, RelocInfo::kNoPosition); + } + + // Make statement: if (cond) { body; } else { break outer; } + Statement* body_or_stop = body; if (cond) { - Statement* empty = factory()->NewEmptyStatement(RelocInfo::kNoPosition); - BreakableStatement* t = LookupBreakTarget(NULL, CHECK_OK); - Statement* stop = factory()->NewBreakStatement(t, RelocInfo::kNoPosition); - Statement* if_not_cond_break = factory()->NewIfStatement( - cond, empty, stop, cond->position()); - inner_block->AddStatement(if_not_cond_break, zone()); + Statement* stop = + factory()->NewBreakStatement(outer_loop, RelocInfo::kNoPosition); + body_or_stop = + factory()->NewIfStatement(cond, body, stop, cond->position()); } - inner_block->AddStatement(body, zone()); + // Make statement: labels: for (; flag == 1; flag = 0, temp_x = x) + // Note that we re-use the original loop node, which retains it labels + // and ensures that any break or continue statements in body point to + // the right place. + loop->Initialize(NULL, flag_cond, compound_next_statement, body_or_stop); + inner_block->AddStatement(loop, zone()); - // For each let variable x: - // make statement: temp_x = x; - for (int i = 0; i < names->length(); i++) { - VariableProxy* temp_proxy = factory()->NewVariableProxy(temps.at(i)); - int pos = scanner()->location().end_pos; - VariableProxy* proxy = factory()->NewVariableProxy(inner_vars.at(i), pos); - Assignment* assignment = factory()->NewAssignment( - Token::ASSIGN, temp_proxy, proxy, RelocInfo::kNoPosition); - Statement* assignment_statement = factory()->NewExpressionStatement( - assignment, RelocInfo::kNoPosition); - inner_block->AddStatement(assignment_statement, zone()); + // Make statement: if (flag == 1) { break; } + { + Expression* compare = NULL; + // Make compare expresion: flag == 1. + { + Expression* const1 = factory()->NewSmiLiteral(1, RelocInfo::kNoPosition); + VariableProxy* flag_proxy = factory()->NewVariableProxy(flag); + compare = + factory()->NewCompareOperation(Token::EQ, flag_proxy, const1, pos); + } + Statement* stop = + factory()->NewBreakStatement(outer_loop, RelocInfo::kNoPosition); + Statement* empty = factory()->NewEmptyStatement(RelocInfo::kNoPosition); + Statement* if_flag_break = + factory()->NewIfStatement(compare, stop, empty, RelocInfo::kNoPosition); + inner_block->AddStatement(if_flag_break, zone()); } inner_scope->set_end_position(scanner()->location().end_pos); inner_block->set_scope(inner_scope); scope_ = for_scope; - loop->Initialize(NULL, NULL, NULL, inner_block); + outer_loop->Initialize(NULL, NULL, NULL, inner_block); return outer_block; } diff --git a/deps/v8/test/mjsunit/harmony/regress/regress-3683.js b/deps/v8/test/mjsunit/harmony/regress/regress-3683.js new file mode 100644 index 00000000000..a00d82bd1f5 --- /dev/null +++ b/deps/v8/test/mjsunit/harmony/regress/regress-3683.js @@ -0,0 +1,84 @@ +// Copyright 2014 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. +// +// Flags: --harmony-scoping + +"use strict"; + +// Simplest case +var count = 0; +for (let x = 0; x < 10;) { + x++; + count++; + continue; +} +assertEquals(10, count); + +// Labeled +count = 0; +label: for (let x = 0; x < 10;) { + while (true) { + x++; + count++; + continue label; + } +} +assertEquals(10, count); + +// Simple and labeled +count = 0; +label: for (let x = 0; x < 10;) { + x++; + count++; + continue label; +} +assertEquals(10, count); + +// Shadowing loop variable in same scope as continue +count = 0; +for (let x = 0; x < 10;) { + x++; + count++; + { + let x = "hello"; + continue; + } +} +assertEquals(10, count); + +// Nested let-bound for loops, inner continue +count = 0; +for (let x = 0; x < 10;) { + x++; + for (let y = 0; y < 2;) { + y++; + count++; + continue; + } +} +assertEquals(20, count); + +// Nested let-bound for loops, outer continue +count = 0; +for (let x = 0; x < 10;) { + x++; + for (let y = 0; y < 2;) { + y++; + count++; + } + continue; +} +assertEquals(20, count); + +// Nested let-bound for loops, labeled continue +count = 0; +outer: for (let x = 0; x < 10;) { + x++; + for (let y = 0; y < 2;) { + y++; + count++; + if (y == 2) continue outer; + } +} +assertEquals(20, count);