[libc++][Android] Allow testing libc++ with clang-r536225 (#116149)
[llvm-project.git] / libc / src / unistd / linux / read.cpp
blob4419900f2330ed62b3adcd737fd8d910735c0a05
1 //===-- Linux implementation of read --------------------------------------===//
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 //===----------------------------------------------------------------------===//
9 #include "src/unistd/read.h"
11 #include "src/__support/OSUtil/syscall.h" // For internal syscall function.
12 #include "src/__support/common.h"
13 #include "src/__support/macros/config.h"
14 #include "src/__support/macros/sanitizer.h" // for MSAN_UNPOISON
15 #include "src/errno/libc_errno.h"
16 #include <sys/syscall.h> // For syscall numbers.
18 namespace LIBC_NAMESPACE_DECL {
20 LLVM_LIBC_FUNCTION(ssize_t, read, (int fd, void *buf, size_t count)) {
21 ssize_t ret = LIBC_NAMESPACE::syscall_impl<ssize_t>(SYS_read, fd, buf, count);
22 if (ret < 0) {
23 libc_errno = static_cast<int>(-ret);
24 return -1;
26 // The cast is important since there is a check that dereferences the pointer
27 // which fails on void*.
28 MSAN_UNPOISON(reinterpret_cast<char *>(buf), count);
29 return ret;
32 } // namespace LIBC_NAMESPACE_DECL