| //===-- Linux implementation of readlink ----------------------------------===// |
| // |
| // 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/readlink.h" |
| |
| #include "src/__support/OSUtil/syscall.h" // For internal syscall function. |
| #include "src/__support/common.h" |
| |
| #include "src/errno/libc_errno.h" |
| #include <fcntl.h> |
| #include <sys/syscall.h> // For syscall numbers. |
| |
| namespace __llvm_libc { |
| |
| LLVM_LIBC_FUNCTION(ssize_t, readlink, |
| (const char *__restrict path, char *__restrict buf, |
| size_t bufsize)) { |
| #ifdef SYS_readlink |
| ssize_t ret = __llvm_libc::syscall_impl(SYS_readlink, path, buf, bufsize); |
| #elif defined(SYS_readlinkat) |
| ssize_t ret = |
| __llvm_libc::syscall_impl(SYS_readlinkat, AT_FDCWD, path, buf, bufsize); |
| #else |
| #error "readlink or readlinkat syscalls not available." |
| #endif |
| if (ret < 0) { |
| libc_errno = -ret; |
| return -1; |
| } |
| return ret; |
| } |
| |
| } // namespace __llvm_libc |