xref: /aosp_15_r20/external/llvm-libc/src/unistd/linux/readlinkat.cpp (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
1 //===-- Linux implementation of readlinkat --------------------------------===//
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/unistd/readlinkat.h"
10 
11 #include "src/__support/OSUtil/syscall.h" // For internal syscall function.
12 #include "src/__support/common.h"
13 
14 #include "hdr/fcntl_macros.h"
15 #include "src/__support/macros/config.h"
16 #include "src/errno/libc_errno.h"
17 #include <sys/syscall.h> // For syscall numbers.
18 
19 namespace LIBC_NAMESPACE_DECL {
20 
21 LLVM_LIBC_FUNCTION(ssize_t, readlinkat,
22                    (int fd, const char *__restrict path, char *__restrict buf,
23                     size_t bufsize)) {
24   ssize_t ret = LIBC_NAMESPACE::syscall_impl<ssize_t>(SYS_readlinkat, fd, path,
25                                                       buf, bufsize);
26   if (ret < 0) {
27     libc_errno = static_cast<int>(-ret);
28     return -1;
29   }
30   return ret;
31 }
32 
33 } // namespace LIBC_NAMESPACE_DECL
34