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1 //===-- Implementation of lsearch -------------------------------*- C++ -*-===//
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-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "src/search/lsearch.h"
10 #include "src/__support/CPP/cstddef.h" // cpp::byte
11 #include "src/__support/common.h"
12 #include "src/__support/macros/config.h"
13 #include "src/__support/memory_size.h"
14 #include "src/string/memory_utils/inline_memcpy.h"
15 
16 namespace LIBC_NAMESPACE_DECL {
17 LLVM_LIBC_FUNCTION(void *, lsearch,
18                    (const void *key, void *base, size_t *nmemb, size_t size,
19                     int (*compar)(const void *, const void *))) {
20   if (key == nullptr || base == nullptr || nmemb == nullptr ||
21       compar == nullptr)
22     return nullptr;
23 
24   size_t byte_len = 0;
25   if (internal::mul_overflow(*nmemb, size, &byte_len))
26     return nullptr;
27 
28   const cpp::byte *next = reinterpret_cast<const cpp::byte *>(base);
29   const cpp::byte *end = next + byte_len;
30   for (; next < end; next += size)
31     if (compar(key, next) == 0)
32       return const_cast<cpp::byte *>(next);
33 
34   *nmemb += 1;
35   inline_memcpy(const_cast<cpp::byte *>(end), key, size);
36   return const_cast<cpp::byte *>(end);
37 }
38 
39 } // namespace LIBC_NAMESPACE_DECL
40