1 //===-- Linux implementation of truncate ----------------------------------===//
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
7 //===----------------------------------------------------------------------===//
9 #include "src/unistd/truncate.h"
11 #include "src/__support/OSUtil/syscall.h" // For internal syscall function.
12 #include "src/__support/common.h"
13 #include "src/errno/libc_errno.h"
15 #include <stdint.h> // For uint64_t.
16 #include <sys/syscall.h> // For syscall numbers.
19 namespace LIBC_NAMESPACE
{
21 LLVM_LIBC_FUNCTION(int, truncate
, (const char *path
, off_t len
)) {
23 int ret
= LIBC_NAMESPACE::syscall_impl
<int>(SYS_truncate
, path
, len
);
24 #elif defined(SYS_truncate64)
25 // Same as truncate but can handle large offsets
26 static_assert(sizeof(off_t
) == 8);
27 int ret
= LIBC_NAMESPACE::syscall_impl
<int>(SYS_truncate64
, path
, (long)len
,
28 (long)(((uint64_t)(len
)) >> 32));
30 #error "truncate and truncate64 syscalls not available."
39 } // namespace LIBC_NAMESPACE