Commit b54f7d3c authored by dslomov@chromium.org's avatar dslomov@chromium.org

harmony-scoping: Allow 'const' iteration variables in strict mode.

R=rossberg@chromium.org
BUG=v8:2506
LOG=N

Review URL: https://codereview.chromium.org/671913002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24834 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
parent 778c500d
......@@ -2156,6 +2156,7 @@ Block* Parser::ParseVariableDeclarations(
Block* block = factory()->NewBlock(NULL, 1, true, pos);
int nvars = 0; // the number of variables declared
const AstRawString* name = NULL;
bool is_for_iteration_variable;
do {
if (fni_ != NULL) fni_->Enter();
......@@ -2179,6 +2180,13 @@ Block* Parser::ParseVariableDeclarations(
// For let/const declarations in harmony mode, we can also immediately
// pre-resolve the proxy because it resides in the same scope as the
// declaration.
is_for_iteration_variable =
var_context == kForStatement &&
(peek() == Token::IN || PeekContextualKeyword(CStrVector("of")));
if (is_for_iteration_variable && mode == CONST) {
needs_init = false;
}
Interface* interface =
is_const ? Interface::NewConst() : Interface::NewValue();
VariableProxy* proxy = NewUnresolved(name, mode, interface);
......@@ -2224,7 +2232,8 @@ Block* Parser::ParseVariableDeclarations(
Expression* value = NULL;
int pos = -1;
// Harmony consts have non-optional initializers.
if (peek() == Token::ASSIGN || mode == CONST) {
if (peek() == Token::ASSIGN ||
(mode == CONST && !is_for_iteration_variable)) {
Expect(Token::ASSIGN, CHECK_OK);
pos = position();
value = ParseAssignmentExpression(var_context != kForStatement, CHECK_OK);
......@@ -2357,7 +2366,7 @@ Block* Parser::ParseVariableDeclarations(
// If there was a single non-const declaration, return it in the output
// parameter for possible use by for/in.
if (nvars == 1 && !is_const) {
if (nvars == 1 && (!is_const || is_for_iteration_variable)) {
*out = name;
}
......@@ -3094,7 +3103,8 @@ Statement* Parser::ParseForStatement(ZoneList<const AstRawString*>* labels,
Expect(Token::LPAREN, CHECK_OK);
for_scope->set_start_position(scanner()->location().beg_pos);
if (peek() != Token::SEMICOLON) {
if (peek() == Token::VAR || peek() == Token::CONST) {
if (peek() == Token::VAR ||
(peek() == Token::CONST && strict_mode() == SLOPPY)) {
bool is_const = peek() == Token::CONST;
const AstRawString* name = NULL;
VariableDeclarationProperties decl_props = kHasNoInitializers;
......@@ -3131,8 +3141,10 @@ Statement* Parser::ParseForStatement(ZoneList<const AstRawString*>* labels,
} else {
init = variable_statement;
}
} else if (peek() == Token::LET && strict_mode() == STRICT) {
} else if ((peek() == Token::LET || peek() == Token::CONST) &&
strict_mode() == STRICT) {
DCHECK(allow_harmony_scoping());
bool is_const = peek() == Token::CONST;
const AstRawString* name = NULL;
VariableDeclarationProperties decl_props = kHasNoInitializers;
Block* variable_statement =
......@@ -3145,13 +3157,13 @@ Statement* Parser::ParseForStatement(ZoneList<const AstRawString*>* labels,
if (accept_IN && CheckInOrOf(accept_OF, &mode)) {
// Rewrite a for-in statement of the form
//
// for (let x in e) b
// for (let/const x in e) b
//
// into
//
// <let x' be a temporary variable>
// for (x' in e) {
// let x;
// let/const x;
// x = x';
// b;
// }
......@@ -3171,13 +3183,13 @@ Statement* Parser::ParseForStatement(ZoneList<const AstRawString*>* labels,
scope_ = for_scope;
Expect(Token::RPAREN, CHECK_OK);
VariableProxy* each =
scope_->NewUnresolved(factory(), name, Interface::NewValue());
VariableProxy* each = scope_->NewUnresolved(factory(), name);
Statement* body = ParseStatement(NULL, CHECK_OK);
Block* body_block =
factory()->NewBlock(NULL, 3, false, RelocInfo::kNoPosition);
Token::Value init_op = is_const ? Token::INIT_CONST : Token::ASSIGN;
Assignment* assignment = factory()->NewAssignment(
Token::ASSIGN, each, temp_proxy, RelocInfo::kNoPosition);
init_op, each, temp_proxy, RelocInfo::kNoPosition);
Statement* assignment_statement = factory()->NewExpressionStatement(
assignment, RelocInfo::kNoPosition);
body_block->AddStatement(variable_statement, zone());
......
......@@ -409,6 +409,7 @@ PreParser::Statement PreParser::ParseVariableDeclarations(
// ConstBinding ::
// BindingPattern '=' AssignmentExpression
bool require_initializer = false;
bool is_strict_const = false;
if (peek() == Token::VAR) {
Consume(Token::VAR);
} else if (peek() == Token::CONST) {
......@@ -430,7 +431,8 @@ PreParser::Statement PreParser::ParseVariableDeclarations(
*ok = false;
return Statement::Default();
}
require_initializer = true;
is_strict_const = true;
require_initializer = var_context != kForStatement;
} else {
Scanner::Location location = scanner()->peek_location();
ReportMessageAt(location, "strict_const");
......@@ -460,7 +462,9 @@ PreParser::Statement PreParser::ParseVariableDeclarations(
if (nvars > 0) Consume(Token::COMMA);
ParseIdentifier(kDontAllowEvalOrArguments, CHECK_OK);
nvars++;
if (peek() == Token::ASSIGN || require_initializer) {
if (peek() == Token::ASSIGN || require_initializer ||
// require initializers for multiple consts.
(is_strict_const && peek() == Token::COMMA)) {
Expect(Token::ASSIGN, CHECK_OK);
ParseAssignmentExpression(var_context != kForStatement, CHECK_OK);
if (decl_props != NULL) *decl_props = kHasInitializers;
......@@ -678,13 +682,14 @@ PreParser::Statement PreParser::ParseForStatement(bool* ok) {
if (peek() != Token::SEMICOLON) {
if (peek() == Token::VAR || peek() == Token::CONST ||
(peek() == Token::LET && strict_mode() == STRICT)) {
bool is_let = peek() == Token::LET;
bool is_lexical = peek() == Token::LET ||
(peek() == Token::CONST && strict_mode() == STRICT);
int decl_count;
VariableDeclarationProperties decl_props = kHasNoInitializers;
ParseVariableDeclarations(
kForStatement, &decl_props, &decl_count, CHECK_OK);
bool has_initializers = decl_props == kHasInitializers;
bool accept_IN = decl_count == 1 && !(is_let && has_initializers);
bool accept_IN = decl_count == 1 && !(is_lexical && has_initializers);
bool accept_OF = !has_initializers;
if (accept_IN && CheckInOrOf(accept_OF)) {
ParseExpression(true, CHECK_OK);
......
......@@ -344,14 +344,18 @@ class ParserBase : public Traits {
}
bool CheckContextualKeyword(Vector<const char> keyword) {
if (peek() == Token::IDENTIFIER &&
scanner()->is_next_contextual_keyword(keyword)) {
if (PeekContextualKeyword(keyword)) {
Consume(Token::IDENTIFIER);
return true;
}
return false;
}
bool PeekContextualKeyword(Vector<const char> keyword) {
return peek() == Token::IDENTIFIER &&
scanner()->is_next_contextual_keyword(keyword);
}
void ExpectContextualKeyword(Vector<const char> keyword, bool* ok) {
Expect(Token::IDENTIFIER, ok);
if (!*ok) return;
......
......@@ -4205,3 +4205,42 @@ TEST(ObjectLiteralPropertyShorthandYieldInGeneratorError) {
RunParserSyncTest(context_data, name_data, kError, NULL, 0,
always_flags, arraysize(always_flags));
}
TEST(ConstParsingInForIn) {
const char* context_data[][2] = {{"'use strict';", ""},
{"function foo(){ 'use strict';", "}"},
{NULL, NULL}};
const char* data[] = {
"for(const x = 1; ; ) {}",
"for(const x = 1, y = 2;;){}",
"for(const x in [1,2,3]) {}",
"for(const x of [1,2,3]) {}",
NULL};
static const ParserFlag always_flags[] = {kAllowHarmonyScoping};
RunParserSyncTest(context_data, data, kSuccess, NULL, 0, always_flags,
arraysize(always_flags));
}
TEST(ConstParsingInForInError) {
const char* context_data[][2] = {{"'use strict';", ""},
{"function foo(){ 'use strict';", "}"},
{NULL, NULL}};
const char* data[] = {
"for(const x,y = 1; ; ) {}",
"for(const x = 4 in [1,2,3]) {}",
"for(const x = 4, y in [1,2,3]) {}",
"for(const x = 4 of [1,2,3]) {}",
"for(const x = 4, y of [1,2,3]) {}",
"for(const x = 1, y = 2 in []) {}",
"for(const x,y in []) {}",
"for(const x = 1, y = 2 of []) {}",
"for(const x,y of []) {}",
NULL};
static const ParserFlag always_flags[] = {kAllowHarmonyScoping};
RunParserSyncTest(context_data, data, kError, NULL, 0, always_flags,
arraysize(always_flags));
}
// 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';
// Top-level code
let s = 0;
let f = [undefined, undefined, undefined]
for (const x of [1,2,3]) {
s += x;
f[x-1] = function() { return x; }
}
assertEquals(6, s);
assertEquals(1, f[0]());
assertEquals(2, f[1]());
assertEquals(3, f[2]());
let x = 1;
s = 0;
for (const x of [x, x+1, x+2]) {
s += x;
}
assertEquals(6, s);
s = 0;
var q = 1;
for (const q of [q, q+1, q+2]) {
s += q;
}
assertEquals(6, s);
let z = 1;
s = 0;
for (const x = 1; z < 2; z++) {
s += x + z;
}
assertEquals(2, s);
s = "";
for (const x in [1,2,3]) {
s += x;
}
assertEquals("012", s);
assertThrows(function() { for(const x in [1,2,3]) { x++ } }, SyntaxError);
// Function scope
(function() {
let s = 0;
for (const x of [1,2,3]) {
s += x;
}
assertEquals(6, s);
let x = 1;
s = 0;
for (const x of [x, x+1, x+2]) {
s += x;
}
assertEquals(6, s);
s = 0;
var q = 1;
for (const q of [q, q+1, q+2]) {
s += q;
}
assertEquals(6, s);
s = "";
for (const x in [1,2,3]) {
s += x;
}
assertEquals("012", s);
}());
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