| //===-- Linux implementation of ftruncate ---------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "src/unistd/ftruncate.h" |
| |
| #include "src/__support/OSUtil/syscall.h" // For internal syscall function. |
| #include "src/__support/common.h" |
| |
| #include "src/errno/libc_errno.h" |
| #include <stdint.h> // For uint64_t. |
| #include <sys/syscall.h> // For syscall numbers. |
| #include <unistd.h> |
| |
| namespace LIBC_NAMESPACE { |
| |
| LLVM_LIBC_FUNCTION(int, ftruncate, (int fd, off_t len)) { |
| #ifdef SYS_ftruncate |
| int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_ftruncate, fd, len); |
| #elif defined(SYS_ftruncate64) |
| // Same as ftruncate but can handle large offsets |
| static_assert(sizeof(off_t) == 8); |
| int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_ftruncate64, fd, (long)len, |
| (long)(((uint64_t)(len)) >> 32)); |
| #else |
| #error "ftruncate and ftruncate64 syscalls not available." |
| #endif |
| |
| if (ret < 0) { |
| libc_errno = -ret; |
| return -1; |
| } |
| return 0; |
| } |
| |
| } // namespace LIBC_NAMESPACE |