| 1 | //===-- Implementation of memrchr -----------------------------------------===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | #include "src/string/memrchr.h" |
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| 10 | #include "src/__support/common.h" |
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| 11 | #include "src/__support/macros/config.h" |
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| 12 | #include "src/__support/macros/null_check.h" |
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| 13 | #include <stddef.h> |
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| 14 | |
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| 15 | namespace LIBC_NAMESPACE_DECL { |
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| 16 | |
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| 17 | LLVM_LIBC_FUNCTION(void *, memrchr, (const void *src, int c, size_t n)) { |
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| 18 | |
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| 19 | if (n) |
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| 20 | LIBC_CRASH_ON_NULLPTR(src); |
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| 21 | |
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| 22 | const unsigned char *str = reinterpret_cast<const unsigned char *>(src); |
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| 23 | const unsigned char ch = static_cast<unsigned char>(c); |
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| 24 | for (; n != 0; --n) { |
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| 25 | const unsigned char *s = str + n - 1; |
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| 26 | if (*s == ch) |
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| 27 | return const_cast<unsigned char *>(s); |
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| 28 | } |
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| 29 | return nullptr; |
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| 30 | } |
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| 31 | |
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| 32 | } // namespace LIBC_NAMESPACE_DECL |
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| 33 | |
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