v8/test/mjsunit/constant-folding.js
adamk ed18aa65ea Remove support for legacy const, part 1
Now that ES2015 const has shipped, in Chrome 49, legacy const declarations
are no more. This lets us remove a bunch of code from many parts of the
codebase.

In this patch, I remove parser support for generating legacy const variables
from const declarations. This also removes the special "illegal declaration"
bit from Scope, which has ripples into all compiler backends.

Also gone are any tests which relied on legacy const declarations.

Note that we do still generate a Variable in mode CONST_LEGACY in one case:
function name bindings in sloppy mode. The likely fix there is to add a new
Variable::Kind for this case and handle it appropriately for stores in each
backend, but I leave that for a later patch to make this one completely
subtractive.

Review URL: https://codereview.chromium.org/1819123002

Cr-Commit-Position: refs/heads/master@{#35002}
2016-03-22 17:52:13 +00:00

228 lines
5.8 KiB
JavaScript

// Copyright 2009 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.
// Test operations that involve one or more constants.
// The code generator now handles compile-time constants specially.
// Test the code generated when operands are known at compile time
// Test count operations involving constants
function test_count() {
var x = "foo";
var y = "3";
x += x++; // ++ and -- apply ToNumber to their operand, even for postfix.
assertEquals(x, "fooNaN", "fooNaN test");
x = "luft";
x += ++x;
assertEquals(x, "luftNaN", "luftNaN test");
assertTrue(y++ === 3, "y++ === 3, where y = \"3\"");
y = 3;
assertEquals(y++, 3, "y++ == 3, where y = 3");
y = "7.1";
assertTrue(y++ === 7.1, "y++ === 7.1, where y = \"7.1\"");
var z = y = x = "9";
assertEquals( z++ + (++y) + x++, 28, "z++ + (++y) + x++ == 28");
z = y = x = 13;
assertEquals( z++ + (++y) + x++, 40, "z++ + (++y) + x++ == 40");
z = y = x = -5.5;
assertEquals( z++ + (++y) + x++, -15.5, "z++ + (++y) + x++ == -15.5");
assertEquals(y, -4.5);
z = y;
z++;
assertEquals(y, -4.5);
z = y;
y++;
assertEquals(z, -4.5);
y = 20;
z = y;
z++;
assertEquals(y, 20);
z = y;
y++;
assertEquals(z, 20);
}
test_count();
// Test comparison operations that involve one or two constant smis.
function test() {
var i = 5;
var j = 3;
assertTrue( j < i );
i = 5; j = 3;
assertTrue( j <= i );
i = 5; j = 3;
assertTrue( i > j );
i = 5; j = 3;
assertTrue( i >= j );
i = 5; j = 3;
assertTrue( i != j );
i = 5; j = 3;
assertTrue( i == i );
i = 5; j = 3;
assertFalse( i < j );
i = 5; j = 3;
assertFalse( i <= j );
i = 5; j = 3;
assertFalse( j > i );
i = 5; j = 3;
assertFalse(j >= i );
i = 5; j = 3;
assertFalse( j == i);
i = 5; j = 3;
assertFalse( i != i);
i = 10 * 10;
while ( i < 107 ) {
++i;
}
j = 21;
assertTrue( j < i );
j = 21;
assertTrue( j <= i );
j = 21;
assertTrue( i > j );
j = 21;
assertTrue( i >= j );
j = 21;
assertTrue( i != j );
j = 21;
assertTrue( i == i );
j = 21;
assertFalse( i < j );
j = 21;
assertFalse( i <= j );
j = 21;
assertFalse( j > i );
j = 21;
assertFalse(j >= i );
j = 21;
assertFalse( j == i);
j = 21;
assertFalse( i != i);
j = 21;
assertTrue( j == j );
j = 21;
assertFalse( j != j );
assertTrue( 100 > 99 );
assertTrue( 101 >= 90 );
assertTrue( 11111 > -234 );
assertTrue( -888 <= -20 );
while ( 234 > 456 ) {
i = i + 1;
}
switch(3) {
case 5:
assertUnreachable();
break;
case 3:
j = 13;
default:
i = 2;
case 7:
j = 17;
break;
case 9:
j = 19;
assertUnreachable();
break;
}
assertEquals(17, j, "switch with constant value");
}
function TrueToString() {
return true.toString();
}
function FalseToString() {
return false.toString();
}
function BoolTest() {
assertEquals("true", TrueToString());
assertEquals("true", TrueToString());
assertEquals("true", TrueToString());
assertEquals("false", FalseToString());
assertEquals("false", FalseToString());
assertEquals("false", FalseToString());
Boolean.prototype.toString = function() { return "foo"; }
assertEquals("foo", TrueToString());
assertEquals("foo", FalseToString());
}
// Some tests of shifts that get into the corners in terms of coverage.
// We generate different code for the case where the operand is a constant.
function ShiftTest() {
var x = 123;
assertEquals(x, x >> 0);
assertEquals(x, x << 0);
assertEquals(x, x >>> 0);
assertEquals(61, x >> 1);
assertEquals(246, x << 1);
assertEquals(61, x >>> 1);
x = -123;
assertEquals(x, x >> 0);
assertEquals(x, x << 0);
assertEquals(0x10000 * 0x10000 + x, x >>> 0);
assertEquals(-62, x >> 1);
assertEquals(-246, x << 1);
assertEquals(0x10000 * 0x8000 - 62, x >>> 1);
// Answer is non-Smi so the subtraction is not folded in the code
// generator.
assertEquals(-0x40000001, -0x3fffffff - 2);
x = 123;
assertEquals(0, x & 0);
// Answer is non-smi and lhs of << is a temporary heap number that we can
// overwrite.
x = 123.0001;
assertEquals(1073741824, (x * x) << 30);
x = 123;
// Answer is non-smi and lhs of << is a temporary heap number that we think
// we can overwrite (but we can't because it's a Smi).
assertEquals(1073741824, (x * x) << 30);
}
test();
BoolTest();
ShiftTest();