1// Copyright 2021 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#include 'src/builtins/builtins-string-gen.h' 6 7namespace string { 8 9// https://tc39.es/ecma262/#sec-string.prototype.indexof 10transitioning javascript builtin 11StringPrototypeIndexOf( 12 js-implicit context: NativeContext, receiver: JSAny)(...arguments): Smi { 13 const methodName: constexpr string = 'String.prototype.indexOf'; 14 const searchString: JSAny = arguments[0]; 15 const position: JSAny = arguments[1]; 16 17 // 1. Let O be ? RequireObjectCoercible(this value). 18 // 2. Let S be ? ToString(O). 19 const s = ToThisString(receiver, methodName); 20 21 // 3. Let searchStr be ? ToString(searchString). 22 const searchStr = ToString_Inline(searchString); 23 24 // 4. Let pos be ? ToIntegerOrInfinity(position). 25 // 5. Assert: If position is undefined, then pos is 0. 26 let start: Smi = 0; 27 if (position != Undefined) { 28 // 6. Let len be the length of S. 29 const len = s.length_uintptr; 30 31 // 7. Let start be the result of clamping pos between 0 and len. 32 StaticAssertStringLengthFitsSmi(); 33 start = Convert<Smi>(Signed(ClampToIndexRange(position, len))); 34 } 35 36 // 8. Let index be ! StringIndexOf(S, searchStr, start). 37 return StringIndexOf(s, searchStr, start); 38} 39} 40