34 lines · cpp
1//===-- Implementation of strcasestr --------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "src/string/strcasestr.h"10 11#include "src/__support/common.h"12#include "src/__support/ctype_utils.h"13#include "src/__support/macros/config.h"14#include "src/__support/macros/null_check.h"15#include "src/string/memory_utils/inline_strstr.h"16 17namespace LIBC_NAMESPACE_DECL {18 19// TODO: This is a simple brute force implementation. This can be20// improved upon using well known string matching algorithms.21LLVM_LIBC_FUNCTION(char *, strcasestr,22 (const char *haystack, const char *needle)) {23 auto case_cmp = [](char a, char b) {24 return static_cast<int>(LIBC_NAMESPACE::internal::tolower(a)) -25 static_cast<int>(LIBC_NAMESPACE::internal::tolower(b));26 };27 28 LIBC_CRASH_ON_NULLPTR(haystack);29 LIBC_CRASH_ON_NULLPTR(needle);30 return inline_strstr(haystack, needle, case_cmp);31}32 33} // namespace LIBC_NAMESPACE_DECL34