[libc-commits] [libc] [llvm] [libc] Use a syscall wrapper for readv (PR #237181)
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Fri Oct 30 04:36:36 PDT 2026
llvmorg-github-actions[bot] wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-libc
Author: Connector Switch (c8ef)
<details>
<summary>Changes</summary>
This PR move readv behind the centralized syscall wrappers, following libc/docs/dev/syscall_wrapper_refactor.md.
---
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Full diff: https://github.com/llvm/llvm-project/pull/237181.diff
5 Files Affected:
- (modified) libc/src/__support/OSUtil/linux/syscall_wrappers/CMakeLists.txt (+14)
- (added) libc/src/__support/OSUtil/linux/syscall_wrappers/readv.h (+36)
- (modified) libc/src/sys/uio/linux/CMakeLists.txt (+9-8)
- (modified) libc/src/sys/uio/linux/readv.cpp (+6-8)
- (modified) utils/bazel/llvm-project-overlay/libc/BUILD.bazel (+38)
``````````diff
diff --git a/libc/src/__support/OSUtil/linux/syscall_wrappers/CMakeLists.txt b/libc/src/__support/OSUtil/linux/syscall_wrappers/CMakeLists.txt
index 8f3515b972cc7a..ee334a1f314dc2 100644
--- a/libc/src/__support/OSUtil/linux/syscall_wrappers/CMakeLists.txt
+++ b/libc/src/__support/OSUtil/linux/syscall_wrappers/CMakeLists.txt
@@ -1479,6 +1479,20 @@ add_header_library(
libc.include.sys_syscall
)
+add_header_library(
+ readv
+ HDRS
+ readv.h
+ DEPENDS
+ libc.hdr.types.ssize_t
+ libc.hdr.types.struct_iovec
+ libc.include.sys_syscall
+ libc.src.__support.OSUtil.osutil
+ libc.src.__support.common
+ libc.src.__support.error_or
+ libc.src.__support.macros.config
+)
+
add_header_library(
rename
HDRS
diff --git a/libc/src/__support/OSUtil/linux/syscall_wrappers/readv.h b/libc/src/__support/OSUtil/linux/syscall_wrappers/readv.h
new file mode 100644
index 00000000000000..0c09a015303f0e
--- /dev/null
+++ b/libc/src/__support/OSUtil/linux/syscall_wrappers/readv.h
@@ -0,0 +1,36 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Syscall wrapper for readv.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_SYSCALL_WRAPPERS_READV_H
+#define LLVM_LIBC_SRC___SUPPORT_OSUTIL_SYSCALL_WRAPPERS_READV_H
+
+#include "hdr/types/ssize_t.h"
+#include "hdr/types/struct_iovec.h"
+#include "src/__support/OSUtil/linux/syscall.h" // syscall_checked
+#include "src/__support/common.h"
+#include "src/__support/error_or.h"
+#include "src/__support/macros/config.h"
+#include <sys/syscall.h> // For syscall numbers
+
+namespace LIBC_NAMESPACE_DECL {
+namespace linux_syscalls {
+
+LIBC_INLINE ErrorOr<ssize_t> readv(int fd, const struct iovec *iov,
+ int iovcnt) {
+ return syscall_checked<ssize_t>(SYS_readv, fd, iov, iovcnt);
+}
+
+} // namespace linux_syscalls
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_SYSCALL_WRAPPERS_READV_H
diff --git a/libc/src/sys/uio/linux/CMakeLists.txt b/libc/src/sys/uio/linux/CMakeLists.txt
index db4fe68e4ca9c5..95177ba0424003 100644
--- a/libc/src/sys/uio/linux/CMakeLists.txt
+++ b/libc/src/sys/uio/linux/CMakeLists.txt
@@ -1,24 +1,25 @@
add_entrypoint_object(
- writev
+ readv
SRCS
- writev.cpp
+ readv.cpp
HDRS
- ../writev.h
+ ../readv.h
DEPENDS
libc.hdr.types.ssize_t
libc.hdr.types.struct_iovec
- libc.include.sys_syscall
- libc.src.__support.OSUtil.osutil
+ libc.src.__support.OSUtil.linux.syscall_wrappers.readv
libc.src.__support.common
+ libc.src.__support.libc_errno
+ libc.src.__support.macros.config
libc.src.errno.errno
)
add_entrypoint_object(
- readv
+ writev
SRCS
- readv.cpp
+ writev.cpp
HDRS
- ../readv.h
+ ../writev.h
DEPENDS
libc.hdr.types.ssize_t
libc.hdr.types.struct_iovec
diff --git a/libc/src/sys/uio/linux/readv.cpp b/libc/src/sys/uio/linux/readv.cpp
index c9d8d87ddc72b8..a9cb74c07014d4 100644
--- a/libc/src/sys/uio/linux/readv.cpp
+++ b/libc/src/sys/uio/linux/readv.cpp
@@ -8,22 +8,20 @@
#include "src/sys/uio/readv.h"
#include "hdr/types/ssize_t.h"
#include "hdr/types/struct_iovec.h"
-#include "src/__support/OSUtil/syscall.h"
+#include "src/__support/OSUtil/linux/syscall_wrappers/readv.h"
#include "src/__support/common.h"
#include "src/__support/libc_errno.h"
-#include <sys/syscall.h>
+#include "src/__support/macros/config.h"
namespace LIBC_NAMESPACE_DECL {
LLVM_LIBC_FUNCTION(ssize_t, readv, (int fd, const iovec *iov, int iovcnt)) {
- long ret = LIBC_NAMESPACE::syscall_impl<long>(SYS_readv, fd, iov, iovcnt);
- // On failure, return -1 and set errno.
- if (ret < 0) {
- libc_errno = static_cast<int>(-ret);
+ auto result = linux_syscalls::readv(fd, iov, iovcnt);
+ if (!result) {
+ libc_errno = result.error();
return -1;
}
- // On success, return number of bytes read.
- return static_cast<ssize_t>(ret);
+ return result.value();
}
} // namespace LIBC_NAMESPACE_DECL
diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
index 2f8018ae18d5f9..331d297113b5c8 100644
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -2877,6 +2877,23 @@ libc_support_library(
],
)
+libc_support_library(
+ name = "__support_osutil_linux_syscall_wrappers_readv",
+ hdrs = ["src/__support/OSUtil/linux/syscall_wrappers/readv.h"],
+ target_compatible_with = select({
+ "@platforms//os:linux": [],
+ "//conditions:default": ["@platforms//:incompatible"],
+ }),
+ deps = [
+ ":__support_common",
+ ":__support_error_or",
+ ":__support_macros_config",
+ ":__support_osutil_syscall",
+ ":types_ssize_t",
+ ":types_struct_iovec",
+ ],
+)
+
libc_support_library(
name = "__support_osutil_linux_syscall_wrappers_recvfrom",
hdrs = ["src/__support/OSUtil/linux/syscall_wrappers/recvfrom.h"],
@@ -20015,6 +20032,27 @@ libc_function(
],
)
+############################### sys/uio targets ################################
+
+libc_function(
+ name = "readv",
+ srcs = ["src/sys/uio/linux/readv.cpp"],
+ hdrs = ["src/sys/uio/readv.h"],
+ target_compatible_with = select({
+ "@platforms//os:linux": [],
+ "//conditions:default": ["@platforms//:incompatible"],
+ }),
+ deps = [
+ ":__support_common",
+ ":__support_libc_errno",
+ ":__support_macros_config",
+ ":__support_osutil_linux_syscall_wrappers_readv",
+ ":errno",
+ ":types_ssize_t",
+ ":types_struct_iovec",
+ ],
+)
+
############################## sys/epoll targets ###############################
libc_function(
``````````
</details>
https://github.com/llvm/llvm-project/pull/237181
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