Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame^] | 1 | // Copyright 2014 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | "use strict"; |
| 6 | |
| 7 | var callSiteCache = new $Map; |
| 8 | |
| 9 | function SameCallSiteElements(rawStrings, other) { |
| 10 | var length = rawStrings.length; |
| 11 | var other = other.raw; |
| 12 | |
| 13 | if (length !== other.length) return false; |
| 14 | |
| 15 | for (var i = 0; i < length; ++i) { |
| 16 | if (rawStrings[i] !== other[i]) return false; |
| 17 | } |
| 18 | |
| 19 | return true; |
| 20 | } |
| 21 | |
| 22 | |
| 23 | function GetCachedCallSite(siteObj, hash) { |
| 24 | var obj = %MapGet(callSiteCache, hash); |
| 25 | |
| 26 | if (IS_UNDEFINED(obj)) return; |
| 27 | |
| 28 | var length = obj.length; |
| 29 | for (var i = 0; i < length; ++i) { |
| 30 | if (SameCallSiteElements(siteObj, obj[i])) return obj[i]; |
| 31 | } |
| 32 | } |
| 33 | |
| 34 | |
| 35 | function SetCachedCallSite(siteObj, hash) { |
| 36 | var obj = %MapGet(callSiteCache, hash); |
| 37 | var array; |
| 38 | |
| 39 | if (IS_UNDEFINED(obj)) { |
| 40 | array = new InternalArray(1); |
| 41 | array[0] = siteObj; |
| 42 | %MapSet(callSiteCache, hash, array); |
| 43 | } else { |
| 44 | obj.push(siteObj); |
| 45 | } |
| 46 | |
| 47 | return siteObj; |
| 48 | } |
| 49 | |
| 50 | |
| 51 | function GetTemplateCallSite(siteObj, rawStrings, hash) { |
| 52 | var cached = GetCachedCallSite(rawStrings, hash); |
| 53 | |
| 54 | if (!IS_UNDEFINED(cached)) return cached; |
| 55 | |
| 56 | %AddNamedProperty(siteObj, "raw", %ObjectFreeze(rawStrings), |
| 57 | READ_ONLY | DONT_ENUM | DONT_DELETE); |
| 58 | |
| 59 | return SetCachedCallSite(%ObjectFreeze(siteObj), hash); |
| 60 | } |
| 61 | |
| 62 | |
| 63 | // ES6 Draft 10-14-2014, section 21.1.2.4 |
| 64 | function StringRaw(callSite) { |
| 65 | // TODO(caitp): Use rest parameters when implemented |
| 66 | var numberOfSubstitutions = %_ArgumentsLength(); |
| 67 | var cooked = ToObject(callSite); |
| 68 | var raw = ToObject(cooked.raw); |
| 69 | var literalSegments = ToLength(raw.length); |
| 70 | if (literalSegments <= 0) return ""; |
| 71 | |
| 72 | var result = ToString(raw[0]); |
| 73 | |
| 74 | for (var i = 1; i < literalSegments; ++i) { |
| 75 | if (i < numberOfSubstitutions) { |
| 76 | result += ToString(%_Arguments(i)); |
| 77 | } |
| 78 | result += ToString(raw[i]); |
| 79 | } |
| 80 | |
| 81 | return result; |
| 82 | } |
| 83 | |
| 84 | |
| 85 | function ExtendStringForTemplates() { |
| 86 | %CheckIsBootstrapping(); |
| 87 | |
| 88 | // Set up the non-enumerable functions on the String object. |
| 89 | InstallFunctions($String, DONT_ENUM, $Array( |
| 90 | "raw", StringRaw |
| 91 | )); |
| 92 | } |
| 93 | |
| 94 | ExtendStringForTemplates(); |