v8/test/mjsunit/es6/debug-blockscopes.js
adamk 62572e011e [es6] Ensure that for-in/of loops have a proper TDZ for their lexically-bound variables
The enumerable expression in a for-in/of loop is supposed to have a TDZ for any
lexically bound names in that loop (there can be more than one with destructuring).

This patch accomplishes this with an almost-correct desugaring. The only thing missing
is proper debugger support (the let declarations added by the desugaring, while invisible
to code due to shadowing, are visible to the debugger).

BUG=v8:4210
LOG=n

Review URL: https://codereview.chromium.org/1218543003

Cr-Commit-Position: refs/heads/master@{#29396}
2015-07-01 00:27:30 +00:00

551 lines
15 KiB
JavaScript

// Copyright 2011 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// Flags: --expose-debug-as debug
// The functions used for testing backtraces. They are at the top to make the
// testing of source line/column easier.
"use strict";
// Get the Debug object exposed from the debug context global object.
var Debug = debug.Debug;
var test_name;
var listener_delegate;
var listener_called;
var exception;
var begin_test_count = 0;
var end_test_count = 0;
var break_count = 0;
// Debug event listener which delegates.
function listener(event, exec_state, event_data, data) {
try {
if (event == Debug.DebugEvent.Break) {
break_count++;
listener_called = true;
listener_delegate(exec_state);
}
} catch (e) {
exception = e;
}
}
// Add the debug event listener.
Debug.setListener(listener);
// Initialize for a new test.
function BeginTest(name) {
test_name = name;
listener_delegate = null;
listener_called = false;
exception = null;
begin_test_count++;
}
// Check result of a test.
function EndTest() {
assertTrue(listener_called, "listerner not called for " + test_name);
assertNull(exception, test_name, exception);
end_test_count++;
}
var global_object = this;
// Check that the scope chain contains the expected types of scopes.
function CheckScopeChain(scopes, exec_state) {
assertEquals(scopes.length, exec_state.frame().scopeCount());
for (var i = 0; i < scopes.length; i++) {
var scope = exec_state.frame().scope(i);
assertTrue(scope.isScope());
assertEquals(scopes[i], scope.scopeType());
// Check the global object when hitting the global scope.
if (scopes[i] == debug.ScopeType.Global) {
// Objects don't have same class (one is "global", other is "Object",
// so just check the properties directly.
assertPropertiesEqual(global_object, scope.scopeObject().value());
}
}
// Get the debug command processor.
var dcp = exec_state.debugCommandProcessor("unspecified_running_state");
// Send a scopes request and check the result.
var json;
var request_json = '{"seq":0,"type":"request","command":"scopes"}';
var response_json = dcp.processDebugJSONRequest(request_json);
var response = JSON.parse(response_json);
assertEquals(scopes.length, response.body.scopes.length);
for (var i = 0; i < scopes.length; i++) {
assertEquals(i, response.body.scopes[i].index);
assertEquals(scopes[i], response.body.scopes[i].type);
if (scopes[i] == debug.ScopeType.Local ||
scopes[i] == debug.ScopeType.Script ||
scopes[i] == debug.ScopeType.Closure) {
assertTrue(response.body.scopes[i].object.ref < 0);
} else {
assertTrue(response.body.scopes[i].object.ref >= 0);
}
var found = false;
for (var j = 0; j < response.refs.length && !found; j++) {
found = response.refs[j].handle == response.body.scopes[i].object.ref;
}
assertTrue(found, "Scope object " + response.body.scopes[i].object.ref + " not found");
}
}
// Check that the content of the scope is as expected. For functions just check
// that there is a function.
function CheckScopeContent(content, number, exec_state) {
var scope = exec_state.frame().scope(number);
var count = 0;
for (var p in content) {
var property_mirror = scope.scopeObject().property(p);
if (property_mirror.isUndefined()) {
print('property ' + p + ' not found in scope');
}
assertFalse(property_mirror.isUndefined(), 'property ' + p + ' not found in scope');
if (typeof(content[p]) === 'function') {
assertTrue(property_mirror.value().isFunction());
} else {
assertEquals(content[p], property_mirror.value().value(), 'property ' + p + ' has unexpected value');
}
count++;
}
// 'arguments' and might be exposed in the local and closure scope. Just
// ignore this.
var scope_size = scope.scopeObject().properties().length;
if (!scope.scopeObject().property('arguments').isUndefined()) {
scope_size--;
}
// Skip property with empty name.
if (!scope.scopeObject().property('').isUndefined()) {
scope_size--;
}
if (count != scope_size) {
print('Names found in scope:');
var names = scope.scopeObject().propertyNames();
for (var i = 0; i < names.length; i++) {
print(names[i]);
}
}
assertEquals(count, scope_size);
// Get the debug command processor.
var dcp = exec_state.debugCommandProcessor("unspecified_running_state");
// Send a scope request for information on a single scope and check the
// result.
var request_json = '{"seq":0,"type":"request","command":"scope","arguments":{"number":';
request_json += scope.scopeIndex();
request_json += '}}';
var response_json = dcp.processDebugJSONRequest(request_json);
var response = JSON.parse(response_json);
assertEquals(scope.scopeType(), response.body.type);
assertEquals(number, response.body.index);
if (scope.scopeType() == debug.ScopeType.Local ||
scope.scopeType() == debug.ScopeType.Closure) {
assertTrue(response.body.object.ref < 0);
} else {
assertTrue(response.body.object.ref >= 0);
}
var found = false;
for (var i = 0; i < response.refs.length && !found; i++) {
found = response.refs[i].handle == response.body.object.ref;
}
assertTrue(found, "Scope object " + response.body.object.ref + " not found");
}
// Simple empty block scope in local scope.
BeginTest("Local block 1");
function local_block_1() {
{
debugger;
}
}
listener_delegate = function(exec_state) {
CheckScopeChain([debug.ScopeType.Local,
debug.ScopeType.Script,
debug.ScopeType.Global], exec_state);
CheckScopeContent({}, 0, exec_state);
};
local_block_1();
EndTest();
// Simple empty block scope in local scope with a parameter.
BeginTest("Local 2");
function local_2(a) {
{
debugger;
}
}
listener_delegate = function(exec_state) {
CheckScopeChain([debug.ScopeType.Local,
debug.ScopeType.Script,
debug.ScopeType.Global], exec_state);
CheckScopeContent({a:1}, 0, exec_state);
};
local_2(1);
EndTest();
// Local scope with a parameter and a local variable.
BeginTest("Local 3");
function local_3(a) {
let x = 3;
debugger;
}
listener_delegate = function(exec_state) {
CheckScopeChain([debug.ScopeType.Local,
debug.ScopeType.Script,
debug.ScopeType.Global], exec_state);
CheckScopeContent({a:1,x:3}, 0, exec_state);
};
local_3(1);
EndTest();
// Local scope with parameters and local variables.
BeginTest("Local 4");
function local_4(a, b) {
let x = 3;
let y = 4;
debugger;
}
listener_delegate = function(exec_state) {
CheckScopeChain([debug.ScopeType.Local,
debug.ScopeType.Script,
debug.ScopeType.Global], exec_state);
CheckScopeContent({a:1,b:2,x:3,y:4}, 0, exec_state);
};
local_4(1, 2);
EndTest();
// Single variable in a block scope.
BeginTest("Local 5");
function local_5(a) {
{
let x = 5;
debugger;
}
}
listener_delegate = function(exec_state) {
CheckScopeChain([debug.ScopeType.Block,
debug.ScopeType.Local,
debug.ScopeType.Script,
debug.ScopeType.Global], exec_state);
CheckScopeContent({x:5}, 0, exec_state);
CheckScopeContent({a:1}, 1, exec_state);
};
local_5(1);
EndTest();
// Two variables in a block scope.
BeginTest("Local 6");
function local_6(a) {
{
let x = 6;
let y = 7;
debugger;
}
}
listener_delegate = function(exec_state) {
CheckScopeChain([debug.ScopeType.Block,
debug.ScopeType.Local,
debug.ScopeType.Script,
debug.ScopeType.Global], exec_state);
CheckScopeContent({x:6,y:7}, 0, exec_state);
CheckScopeContent({a:1}, 1, exec_state);
};
local_6(1);
EndTest();
// Two variables in a block scope.
BeginTest("Local 7");
function local_7(a) {
{
{
let x = 8;
debugger;
}
}
}
listener_delegate = function(exec_state) {
CheckScopeChain([debug.ScopeType.Block,
debug.ScopeType.Local,
debug.ScopeType.Script,
debug.ScopeType.Global], exec_state);
CheckScopeContent({x:8}, 0, exec_state);
CheckScopeContent({a:1}, 1, exec_state);
};
local_7(1);
EndTest();
// Simple closure formed by returning an inner function referering to an outer
// block local variable and an outer function's parameter.
BeginTest("Closure 1");
function closure_1(a) {
var x = 2;
let y = 3;
if (true) {
let z = 4;
function f() {
debugger;
return a + x + y + z;
};
return f;
}
}
listener_delegate = function(exec_state) {
CheckScopeChain([debug.ScopeType.Local,
debug.ScopeType.Block,
debug.ScopeType.Closure,
debug.ScopeType.Script,
debug.ScopeType.Global], exec_state);
CheckScopeContent({}, 0, exec_state);
CheckScopeContent({a:1,x:2,y:3}, 2, exec_state);
};
closure_1(1)();
EndTest();
// Simple for-in loop over the keys of an object.
BeginTest("For loop 1");
function for_loop_1() {
for (let x in {y:undefined}) {
debugger;
}
}
listener_delegate = function(exec_state) {
CheckScopeChain([debug.ScopeType.Block,
debug.ScopeType.Block,
debug.ScopeType.Local,
debug.ScopeType.Script,
debug.ScopeType.Global], exec_state);
CheckScopeContent({x:'y'}, 0, exec_state);
// The function scope contains a temporary iteration variable, but it is
// hidden to the debugger.
// TODO(adamk): This variable is only used to provide a TDZ for the enumerable
// expression and should not be visible to the debugger.
CheckScopeContent({x:undefined}, 1, exec_state);
};
for_loop_1();
EndTest();
// For-in loop over the keys of an object with a block scoped let variable
// shadowing the iteration variable.
BeginTest("For loop 2");
function for_loop_2() {
for (let x in {y:undefined}) {
let x = 3;
debugger;
}
}
listener_delegate = function(exec_state) {
CheckScopeChain([debug.ScopeType.Block,
debug.ScopeType.Block,
debug.ScopeType.Block,
debug.ScopeType.Local,
debug.ScopeType.Script,
debug.ScopeType.Global], exec_state);
CheckScopeContent({x:3}, 0, exec_state);
CheckScopeContent({x:'y'}, 1, exec_state);
// The function scope contains a temporary iteration variable, hidden to the
// debugger.
// TODO(adamk): This variable is only used to provide a TDZ for the enumerable
// expression and should not be visible to the debugger.
CheckScopeContent({x:undefined}, 2, exec_state);
};
for_loop_2();
EndTest();
// Simple for loop.
BeginTest("For loop 3");
function for_loop_3() {
for (let x = 3; x < 4; ++x) {
debugger;
}
}
listener_delegate = function(exec_state) {
CheckScopeChain([debug.ScopeType.Block,
debug.ScopeType.Block,
debug.ScopeType.Local,
debug.ScopeType.Script,
debug.ScopeType.Global], exec_state);
CheckScopeContent({x:3}, 0, exec_state);
CheckScopeContent({x:3}, 1, exec_state);
CheckScopeContent({}, 2, exec_state);
};
for_loop_3();
EndTest();
// For loop with a block scoped let variable shadowing the iteration variable.
BeginTest("For loop 4");
function for_loop_4() {
for (let x = 3; x < 4; ++x) {
let x = 5;
debugger;
}
}
listener_delegate = function(exec_state) {
CheckScopeChain([debug.ScopeType.Block,
debug.ScopeType.Block,
debug.ScopeType.Block,
debug.ScopeType.Local,
debug.ScopeType.Script,
debug.ScopeType.Global], exec_state);
CheckScopeContent({x:5}, 0, exec_state);
CheckScopeContent({x:3}, 1, exec_state);
CheckScopeContent({x:3}, 2, exec_state);
CheckScopeContent({}, 3, exec_state);
};
for_loop_4();
EndTest();
// For loop with two variable declarations.
BeginTest("For loop 5");
function for_loop_5() {
for (let x = 3, y = 5; x < 4; ++x) {
debugger;
}
}
listener_delegate = function(exec_state) {
CheckScopeChain([debug.ScopeType.Block,
debug.ScopeType.Block,
debug.ScopeType.Local,
debug.ScopeType.Script,
debug.ScopeType.Global], exec_state);
CheckScopeContent({x:3,y:5}, 0, exec_state);
CheckScopeContent({x:3,y:5}, 1, exec_state);
CheckScopeContent({}, 2, exec_state);
};
for_loop_5();
EndTest();
// Uninitialized variables
BeginTest("Uninitialized 1");
function uninitialized_1() {
{
debugger;
let x = 1;
}
}
listener_delegate = function(exec_state) {
CheckScopeChain([debug.ScopeType.Block,
debug.ScopeType.Local,
debug.ScopeType.Script,
debug.ScopeType.Global], exec_state);
CheckScopeContent({x:undefined}, 0, exec_state);
};
uninitialized_1();
EndTest();
// Block scopes shadowing
BeginTest("Block scopes shadowing 1");
function shadowing_1() {
let i = 0;
{
let i = 5;
debugger;
assertEquals(27, i);
}
assertEquals(0, i);
debugger;
assertEquals(27, i);
}
listener_delegate = function (exec_state) {
exec_state.frame(0).evaluate("i = 27");
}
shadowing_1();
EndTest();
// Block scopes shadowing
BeginTest("Block scopes shadowing 2");
function shadowing_2() {
let i = 0;
{
let j = 5;
debugger;
assertEquals(27, j);
}
assertEquals(0, i);
}
listener_delegate = function (exec_state) {
exec_state.frame(0).evaluate("j = 27");
}
shadowing_2();
EndTest();