[libc-commits] [libc] [libc][fcntl] Implement posix_fadvise function. (PR #220790)
via libc-commits
libc-commits at lists.llvm.org
Thu Sep 3 07:00:33 PDT 2026
https://github.com/lntue updated https://github.com/llvm/llvm-project/pull/220790
>From ae27d9f431367e498f6b61ea69fc94d60633d3cd Mon Sep 17 00:00:00 2001
From: Tue Ly <lntue.h at gmail.com>
Date: Thu, 3 Sep 2026 03:14:50 +0000
Subject: [PATCH 1/3] [libc][fcntl] Implement posix_fadvise function.
---
libc/config/linux/aarch64/entrypoints.txt | 1 +
libc/config/linux/riscv/entrypoints.txt | 1 +
libc/config/linux/x86_64/entrypoints.txt | 1 +
libc/include/fcntl.yaml | 21 +++++
.../llvm-libc-macros/linux/fcntl-macros.h | 8 ++
libc/src/fcntl/CMakeLists.txt | 7 ++
libc/src/fcntl/linux/CMakeLists.txt | 15 ++++
libc/src/fcntl/linux/posix_fadvise.cpp | 74 ++++++++++++++++++
libc/src/fcntl/posix_fadvise.h | 26 +++++++
libc/test/src/fcntl/CMakeLists.txt | 18 +++++
libc/test/src/fcntl/posix_fadvise_test.cpp | 76 +++++++++++++++++++
11 files changed, 248 insertions(+)
create mode 100644 libc/src/fcntl/linux/posix_fadvise.cpp
create mode 100644 libc/src/fcntl/posix_fadvise.h
create mode 100644 libc/test/src/fcntl/posix_fadvise_test.cpp
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index fbd9239728bac..3b6ea7219b8eb 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -41,6 +41,7 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.fcntl.fcntl
libc.src.fcntl.open
libc.src.fcntl.openat
+ libc.src.fcntl.posix_fadvise
# poll.h entrypoints
libc.src.poll.poll
diff --git a/libc/config/linux/riscv/entrypoints.txt b/libc/config/linux/riscv/entrypoints.txt
index bd906c6900008..70e5f1fe102c3 100644
--- a/libc/config/linux/riscv/entrypoints.txt
+++ b/libc/config/linux/riscv/entrypoints.txt
@@ -52,6 +52,7 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.fcntl.fcntl
libc.src.fcntl.open
libc.src.fcntl.openat
+ libc.src.fcntl.posix_fadvise
# net/if.h entrypoints
libc.src.net.if_indextoname
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index e6aeb3abe0672..d9ddd0435749d 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -52,6 +52,7 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.fcntl.fcntl
libc.src.fcntl.open
libc.src.fcntl.openat
+ libc.src.fcntl.posix_fadvise
# net/if.h entrypoints
libc.src.net.if_indextoname
diff --git a/libc/include/fcntl.yaml b/libc/include/fcntl.yaml
index 43226b455051a..e2f174447b6ba 100644
--- a/libc/include/fcntl.yaml
+++ b/libc/include/fcntl.yaml
@@ -10,6 +10,18 @@ macros:
macro_header: fcntl-macros.h
- macro_name: AT_EACCESS
macro_header: fcntl-macros.h
+ - macro_name: POSIX_FADV_NORMAL
+ macro_header: fcntl-macros.h
+ - macro_name: POSIX_FADV_RANDOM
+ macro_header: fcntl-macros.h
+ - macro_name: POSIX_FADV_SEQUENTIAL
+ macro_header: fcntl-macros.h
+ - macro_name: POSIX_FADV_WILLNEED
+ macro_header: fcntl-macros.h
+ - macro_name: POSIX_FADV_DONTNEED
+ macro_header: fcntl-macros.h
+ - macro_name: POSIX_FADV_NOREUSE
+ macro_header: fcntl-macros.h
types:
- type_name: mode_t
- type_name: off_t
@@ -52,3 +64,12 @@ functions:
- type: const char *
- type: int
- type: '...'
+ - name: posix_fadvise
+ standards:
+ - posix
+ return_type: int
+ arguments:
+ - type: int
+ - type: off_t
+ - type: off_t
+ - type: int
diff --git a/libc/include/llvm-libc-macros/linux/fcntl-macros.h b/libc/include/llvm-libc-macros/linux/fcntl-macros.h
index 8dcc177434cec..648c4a9ec00da 100644
--- a/libc/include/llvm-libc-macros/linux/fcntl-macros.h
+++ b/libc/include/llvm-libc-macros/linux/fcntl-macros.h
@@ -105,4 +105,12 @@
#define F_SETLKW F_SETLKW64
#endif
+// Advice values for posix_fadvise.
+#define POSIX_FADV_NORMAL 0
+#define POSIX_FADV_RANDOM 1
+#define POSIX_FADV_SEQUENTIAL 2
+#define POSIX_FADV_WILLNEED 3
+#define POSIX_FADV_DONTNEED 4
+#define POSIX_FADV_NOREUSE 5
+
#endif // LLVM_LIBC_MACROS_LINUX_FCNTL_MACROS_H
diff --git a/libc/src/fcntl/CMakeLists.txt b/libc/src/fcntl/CMakeLists.txt
index 77400e9050d08..1d6c31cf98978 100644
--- a/libc/src/fcntl/CMakeLists.txt
+++ b/libc/src/fcntl/CMakeLists.txt
@@ -29,3 +29,10 @@ add_entrypoint_object(
DEPENDS
.${LIBC_TARGET_OS}.openat
)
+
+add_entrypoint_object(
+ posix_fadvise
+ ALIAS
+ DEPENDS
+ .${LIBC_TARGET_OS}.posix_fadvise
+)
diff --git a/libc/src/fcntl/linux/CMakeLists.txt b/libc/src/fcntl/linux/CMakeLists.txt
index a235a99272636..37324a74b5c44 100644
--- a/libc/src/fcntl/linux/CMakeLists.txt
+++ b/libc/src/fcntl/linux/CMakeLists.txt
@@ -48,3 +48,18 @@ add_entrypoint_object(
libc.src.__support.OSUtil.osutil
libc.src.errno.errno
)
+
+add_entrypoint_object(
+ posix_fadvise
+ SRCS
+ posix_fadvise.cpp
+ HDRS
+ ../posix_fadvise.h
+ DEPENDS
+ libc.hdr.types.off_t
+ libc.hdr.stdint_proxy
+ libc.include.sys_syscall
+ libc.src.__support.CPP.bit
+ libc.src.__support.OSUtil.osutil
+ libc.src.__support.common
+)
diff --git a/libc/src/fcntl/linux/posix_fadvise.cpp b/libc/src/fcntl/linux/posix_fadvise.cpp
new file mode 100644
index 0000000000000..a0be70f78ca45
--- /dev/null
+++ b/libc/src/fcntl/linux/posix_fadvise.cpp
@@ -0,0 +1,74 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+/// Linux implementation of posix_fadvise.
+///
+//===----------------------------------------------------------------------===//
+
+#include "src/fcntl/posix_fadvise.h"
+
+#include "hdr/stdint_proxy.h"
+#include "hdr/types/off_t.h"
+#include "src/__support/CPP/bit.h"
+#include "src/__support/OSUtil/syscall.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+#include <sys/syscall.h>
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, posix_fadvise,
+ (int fd, off_t offset, off_t len, int advice)) {
+ int ret;
+ if constexpr (sizeof(long) == sizeof(uint32_t) &&
+ sizeof(off_t) == sizeof(uint64_t)) {
+ uint64_t offset_bits = cpp::bit_cast<uint64_t>(offset);
+ long offset_low = static_cast<long>(offset_bits & UINT32_MAX);
+ long offset_high = static_cast<long>(offset_bits >> 32);
+
+#if defined(SYS_fadvise64_64) || defined(SYS_arm_fadvise64_64)
+ uint64_t len_bits = cpp::bit_cast<uint64_t>(len);
+ long len_low = static_cast<long>(len_bits & UINT32_MAX);
+ long len_high = static_cast<long>(len_bits >> 32);
+#endif
+
+#if defined(SYS_fadvise64_64)
+ ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_fadvise64_64, fd, offset_low,
+ offset_high, len_low, len_high,
+ advice);
+#elif defined(SYS_arm_fadvise64_64)
+ ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_arm_fadvise64_64, fd, advice,
+ offset_low, offset_high, len_low,
+ len_high);
+#elif defined(SYS_fadvise64)
+ ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_fadvise64, fd, offset_low,
+ offset_high,
+ static_cast<size_t>(len), advice);
+#else
+#error "fadvise64 syscall not available."
+#endif
+ } else {
+#if defined(SYS_fadvise64)
+ ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_fadvise64, fd, offset, len,
+ advice);
+#elif defined(SYS_fadvise64_64)
+ ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_fadvise64_64, fd, offset, len,
+ advice);
+#else
+#error "fadvise64 syscall not available."
+#endif
+ }
+
+ if (ret < 0)
+ return -ret;
+ return 0;
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/fcntl/posix_fadvise.h b/libc/src/fcntl/posix_fadvise.h
new file mode 100644
index 0000000000000..1a93521846a92
--- /dev/null
+++ b/libc/src/fcntl/posix_fadvise.h
@@ -0,0 +1,26 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+/// Implementation header for posix_fadvise.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_FCNTL_POSIX_FADVISE_H
+#define LLVM_LIBC_SRC_FCNTL_POSIX_FADVISE_H
+
+#include "hdr/types/off_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int posix_fadvise(int fd, off_t offset, off_t len, int advice);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_FCNTL_POSIX_FADVISE_H
diff --git a/libc/test/src/fcntl/CMakeLists.txt b/libc/test/src/fcntl/CMakeLists.txt
index dd2b473d954c5..d285a7875267c 100644
--- a/libc/test/src/fcntl/CMakeLists.txt
+++ b/libc/test/src/fcntl/CMakeLists.txt
@@ -56,3 +56,21 @@ add_libc_test(
libc.test.UnitTest.ErrnoCheckingTest
libc.test.UnitTest.ErrnoSetterMatcher
)
+
+add_libc_test(
+ posix_fadvise_test
+ SUITE
+ libc_fcntl_unittests
+ SRCS
+ posix_fadvise_test.cpp
+ DEPENDS
+ libc.hdr.errno_macros
+ libc.hdr.fcntl_macros
+ libc.hdr.sys_stat_macros
+ libc.src.errno.errno
+ libc.src.fcntl.creat
+ libc.src.fcntl.posix_fadvise
+ libc.src.unistd.close
+ libc.src.unistd.pipe
+ libc.test.UnitTest.ErrnoCheckingTest
+)
diff --git a/libc/test/src/fcntl/posix_fadvise_test.cpp b/libc/test/src/fcntl/posix_fadvise_test.cpp
new file mode 100644
index 0000000000000..b0b410bb51f64
--- /dev/null
+++ b/libc/test/src/fcntl/posix_fadvise_test.cpp
@@ -0,0 +1,76 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+/// Unittests for posix_fadvise.
+///
+//===----------------------------------------------------------------------===//
+
+#include "hdr/errno_macros.h"
+#include "hdr/fcntl_macros.h"
+#include "hdr/sys_stat_macros.h"
+#include "src/fcntl/creat.h"
+#include "src/fcntl/posix_fadvise.h"
+#include "src/unistd/close.h"
+#include "src/unistd/pipe.h"
+#include "test/UnitTest/ErrnoCheckingTest.h"
+#include "test/UnitTest/Test.h"
+
+using LlvmLibcPosixFadviseTest = LIBC_NAMESPACE::testing::ErrnoCheckingTest;
+
+TEST_F(LlvmLibcPosixFadviseTest, InvalidFileDescriptor) {
+ EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(-1, 0, 0, POSIX_FADV_NORMAL), EBADF);
+ // posix_fadvise must return the error directly and not set errno.
+ ASSERT_ERRNO_SUCCESS();
+}
+
+TEST_F(LlvmLibcPosixFadviseTest, ValidFile) {
+ constexpr const char *TEST_FILE = "testdata/posix_fadvise.test";
+ int fd = LIBC_NAMESPACE::creat(TEST_FILE, S_IRWXU);
+ ASSERT_ERRNO_SUCCESS();
+ ASSERT_GT(fd, 0);
+
+ EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, 0, POSIX_FADV_NORMAL), 0);
+ EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, 0, POSIX_FADV_RANDOM), 0);
+ EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, 0, POSIX_FADV_SEQUENTIAL), 0);
+ EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, 0, POSIX_FADV_WILLNEED), 0);
+ EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, 0, POSIX_FADV_DONTNEED), 0);
+ EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, 0, POSIX_FADV_NOREUSE), 0);
+
+ // Non-zero offset and length
+ EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 10, 20, POSIX_FADV_NORMAL), 0);
+
+ // Invalid advice
+ EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, 0, -1), EINVAL);
+ ASSERT_ERRNO_SUCCESS();
+
+ // Negative len
+ EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, -1, POSIX_FADV_NORMAL),
+ EINVAL);
+ ASSERT_ERRNO_SUCCESS();
+
+ EXPECT_EQ(LIBC_NAMESPACE::close(fd), 0);
+ ASSERT_ERRNO_SUCCESS();
+}
+
+TEST_F(LlvmLibcPosixFadviseTest, Pipe) {
+ int pipefd[2];
+ ASSERT_EQ(LIBC_NAMESPACE::pipe(pipefd), 0);
+ ASSERT_ERRNO_SUCCESS();
+
+ // fadvise on a pipe should return ESPIPE
+ EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(pipefd[0], 0, 0, POSIX_FADV_NORMAL),
+ ESPIPE);
+ EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(pipefd[1], 0, 0, POSIX_FADV_NORMAL),
+ ESPIPE);
+ ASSERT_ERRNO_SUCCESS();
+
+ EXPECT_EQ(LIBC_NAMESPACE::close(pipefd[0]), 0);
+ EXPECT_EQ(LIBC_NAMESPACE::close(pipefd[1]), 0);
+ ASSERT_ERRNO_SUCCESS();
+}
>From 5260dcb3206009e04663d2c824a77e5453ea1924 Mon Sep 17 00:00:00 2001
From: Tue Ly <lntue.h at gmail.com>
Date: Thu, 3 Sep 2026 13:59:12 +0000
Subject: [PATCH 2/3] Address comments.
---
.../linux/syscall_wrappers/CMakeLists.txt | 15 ++++
.../linux/syscall_wrappers/posix_fadvise.h | 75 +++++++++++++++++++
libc/src/fcntl/linux/CMakeLists.txt | 5 +-
libc/src/fcntl/linux/posix_fadvise.cpp | 51 +------------
libc/test/src/fcntl/CMakeLists.txt | 1 +
libc/test/src/fcntl/posix_fadvise_test.cpp | 9 +--
6 files changed, 98 insertions(+), 58 deletions(-)
create mode 100644 libc/src/__support/OSUtil/linux/syscall_wrappers/posix_fadvise.h
diff --git a/libc/src/__support/OSUtil/linux/syscall_wrappers/CMakeLists.txt b/libc/src/__support/OSUtil/linux/syscall_wrappers/CMakeLists.txt
index f4a3d1fa7c20e..6c13f929c195a 100644
--- a/libc/src/__support/OSUtil/linux/syscall_wrappers/CMakeLists.txt
+++ b/libc/src/__support/OSUtil/linux/syscall_wrappers/CMakeLists.txt
@@ -445,6 +445,21 @@ add_header_library(
libc.include.sys_syscall
)
+add_header_library(
+ posix_fadvise
+ HDRS
+ posix_fadvise.h
+ DEPENDS
+ libc.hdr.stdint_proxy
+ libc.hdr.types.off_t
+ libc.include.sys_syscall
+ libc.src.__support.CPP.bit
+ libc.src.__support.OSUtil.osutil
+ libc.src.__support.common
+ libc.src.__support.error_or
+ libc.src.__support.macros.config
+)
+
add_header_library(
ptrace
HDRS
diff --git a/libc/src/__support/OSUtil/linux/syscall_wrappers/posix_fadvise.h b/libc/src/__support/OSUtil/linux/syscall_wrappers/posix_fadvise.h
new file mode 100644
index 0000000000000..ee97b3839b70f
--- /dev/null
+++ b/libc/src/__support/OSUtil/linux/syscall_wrappers/posix_fadvise.h
@@ -0,0 +1,75 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+/// ErrorOr-returning syscall wrapper for posix_fadvise.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_SYSCALL_WRAPPERS_POSIX_FADVISE_H
+#define LLVM_LIBC_SRC___SUPPORT_OSUTIL_SYSCALL_WRAPPERS_POSIX_FADVISE_H
+
+#include "hdr/stdint_proxy.h"
+#include "hdr/types/off_t.h"
+#include "src/__support/CPP/bit.h"
+#include "src/__support/OSUtil/linux/syscall.h" // syscall_impl
+#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<int> posix_fadvise(int fd, off_t offset, off_t len,
+ int advice) {
+ int ret;
+ if constexpr (sizeof(long) == sizeof(uint32_t) &&
+ sizeof(off_t) == sizeof(uint64_t)) {
+ uint64_t offset_bits = cpp::bit_cast<uint64_t>(offset);
+ long offset_low = static_cast<long>(offset_bits & UINT32_MAX);
+ long offset_high = static_cast<long>(offset_bits >> 32);
+
+#if defined(SYS_fadvise64_64) || defined(SYS_arm_fadvise64_64)
+ uint64_t len_bits = cpp::bit_cast<uint64_t>(len);
+ long len_low = static_cast<long>(len_bits & UINT32_MAX);
+ long len_high = static_cast<long>(len_bits >> 32);
+#endif
+
+#if defined(SYS_fadvise64_64)
+ ret = syscall_impl<int>(SYS_fadvise64_64, fd, offset_low, offset_high,
+ len_low, len_high, advice);
+#elif defined(SYS_arm_fadvise64_64)
+ ret = syscall_impl<int>(SYS_arm_fadvise64_64, fd, advice, offset_low,
+ offset_high, len_low, len_high);
+#elif defined(SYS_fadvise64)
+ ret = syscall_impl<int>(SYS_fadvise64, fd, offset_low, offset_high,
+ static_cast<size_t>(len), advice);
+#else
+#error "fadvise64 syscall not available."
+#endif
+ } else {
+#if defined(SYS_fadvise64)
+ ret = syscall_impl<int>(SYS_fadvise64, fd, offset, len, advice);
+#elif defined(SYS_fadvise64_64)
+ ret = syscall_impl<int>(SYS_fadvise64_64, fd, offset, len, advice);
+#else
+#error "fadvise64 syscall not available."
+#endif
+ }
+
+ if (ret < 0)
+ return Error(-ret);
+ return 0;
+}
+
+} // namespace linux_syscalls
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_SYSCALL_WRAPPERS_POSIX_FADVISE_H
diff --git a/libc/src/fcntl/linux/CMakeLists.txt b/libc/src/fcntl/linux/CMakeLists.txt
index 37324a74b5c44..bba33928da17a 100644
--- a/libc/src/fcntl/linux/CMakeLists.txt
+++ b/libc/src/fcntl/linux/CMakeLists.txt
@@ -57,9 +57,6 @@ add_entrypoint_object(
../posix_fadvise.h
DEPENDS
libc.hdr.types.off_t
- libc.hdr.stdint_proxy
- libc.include.sys_syscall
- libc.src.__support.CPP.bit
- libc.src.__support.OSUtil.osutil
+ libc.src.__support.OSUtil.linux.syscall_wrappers.posix_fadvise
libc.src.__support.common
)
diff --git a/libc/src/fcntl/linux/posix_fadvise.cpp b/libc/src/fcntl/linux/posix_fadvise.cpp
index a0be70f78ca45..ed0a539204d0a 100644
--- a/libc/src/fcntl/linux/posix_fadvise.cpp
+++ b/libc/src/fcntl/linux/posix_fadvise.cpp
@@ -13,61 +13,18 @@
#include "src/fcntl/posix_fadvise.h"
-#include "hdr/stdint_proxy.h"
#include "hdr/types/off_t.h"
-#include "src/__support/CPP/bit.h"
-#include "src/__support/OSUtil/syscall.h"
+#include "src/__support/OSUtil/linux/syscall_wrappers/posix_fadvise.h"
#include "src/__support/common.h"
#include "src/__support/macros/config.h"
-#include <sys/syscall.h>
-
namespace LIBC_NAMESPACE_DECL {
LLVM_LIBC_FUNCTION(int, posix_fadvise,
(int fd, off_t offset, off_t len, int advice)) {
- int ret;
- if constexpr (sizeof(long) == sizeof(uint32_t) &&
- sizeof(off_t) == sizeof(uint64_t)) {
- uint64_t offset_bits = cpp::bit_cast<uint64_t>(offset);
- long offset_low = static_cast<long>(offset_bits & UINT32_MAX);
- long offset_high = static_cast<long>(offset_bits >> 32);
-
-#if defined(SYS_fadvise64_64) || defined(SYS_arm_fadvise64_64)
- uint64_t len_bits = cpp::bit_cast<uint64_t>(len);
- long len_low = static_cast<long>(len_bits & UINT32_MAX);
- long len_high = static_cast<long>(len_bits >> 32);
-#endif
-
-#if defined(SYS_fadvise64_64)
- ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_fadvise64_64, fd, offset_low,
- offset_high, len_low, len_high,
- advice);
-#elif defined(SYS_arm_fadvise64_64)
- ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_arm_fadvise64_64, fd, advice,
- offset_low, offset_high, len_low,
- len_high);
-#elif defined(SYS_fadvise64)
- ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_fadvise64, fd, offset_low,
- offset_high,
- static_cast<size_t>(len), advice);
-#else
-#error "fadvise64 syscall not available."
-#endif
- } else {
-#if defined(SYS_fadvise64)
- ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_fadvise64, fd, offset, len,
- advice);
-#elif defined(SYS_fadvise64_64)
- ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_fadvise64_64, fd, offset, len,
- advice);
-#else
-#error "fadvise64 syscall not available."
-#endif
- }
-
- if (ret < 0)
- return -ret;
+ auto result = linux_syscalls::posix_fadvise(fd, offset, len, advice);
+ if (!result)
+ return result.error();
return 0;
}
diff --git a/libc/test/src/fcntl/CMakeLists.txt b/libc/test/src/fcntl/CMakeLists.txt
index d285a7875267c..522a288216f2b 100644
--- a/libc/test/src/fcntl/CMakeLists.txt
+++ b/libc/test/src/fcntl/CMakeLists.txt
@@ -72,5 +72,6 @@ add_libc_test(
libc.src.fcntl.posix_fadvise
libc.src.unistd.close
libc.src.unistd.pipe
+ libc.src.unistd.unlink
libc.test.UnitTest.ErrnoCheckingTest
)
diff --git a/libc/test/src/fcntl/posix_fadvise_test.cpp b/libc/test/src/fcntl/posix_fadvise_test.cpp
index b0b410bb51f64..a857969f6f4b5 100644
--- a/libc/test/src/fcntl/posix_fadvise_test.cpp
+++ b/libc/test/src/fcntl/posix_fadvise_test.cpp
@@ -18,6 +18,7 @@
#include "src/fcntl/posix_fadvise.h"
#include "src/unistd/close.h"
#include "src/unistd/pipe.h"
+#include "src/unistd/unlink.h"
#include "test/UnitTest/ErrnoCheckingTest.h"
#include "test/UnitTest/Test.h"
@@ -32,8 +33,8 @@ TEST_F(LlvmLibcPosixFadviseTest, InvalidFileDescriptor) {
TEST_F(LlvmLibcPosixFadviseTest, ValidFile) {
constexpr const char *TEST_FILE = "testdata/posix_fadvise.test";
int fd = LIBC_NAMESPACE::creat(TEST_FILE, S_IRWXU);
- ASSERT_ERRNO_SUCCESS();
ASSERT_GT(fd, 0);
+ ASSERT_EQ(LIBC_NAMESPACE::unlink(TEST_FILE), 0);
EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, 0, POSIX_FADV_NORMAL), 0);
EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, 0, POSIX_FADV_RANDOM), 0);
@@ -47,30 +48,24 @@ TEST_F(LlvmLibcPosixFadviseTest, ValidFile) {
// Invalid advice
EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, 0, -1), EINVAL);
- ASSERT_ERRNO_SUCCESS();
// Negative len
EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, -1, POSIX_FADV_NORMAL),
EINVAL);
- ASSERT_ERRNO_SUCCESS();
EXPECT_EQ(LIBC_NAMESPACE::close(fd), 0);
- ASSERT_ERRNO_SUCCESS();
}
TEST_F(LlvmLibcPosixFadviseTest, Pipe) {
int pipefd[2];
ASSERT_EQ(LIBC_NAMESPACE::pipe(pipefd), 0);
- ASSERT_ERRNO_SUCCESS();
// fadvise on a pipe should return ESPIPE
EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(pipefd[0], 0, 0, POSIX_FADV_NORMAL),
ESPIPE);
EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(pipefd[1], 0, 0, POSIX_FADV_NORMAL),
ESPIPE);
- ASSERT_ERRNO_SUCCESS();
EXPECT_EQ(LIBC_NAMESPACE::close(pipefd[0]), 0);
EXPECT_EQ(LIBC_NAMESPACE::close(pipefd[1]), 0);
- ASSERT_ERRNO_SUCCESS();
}
>From ca3858e7fc80f5a8e0e8ce4dae7aaf4d42723fc5 Mon Sep 17 00:00:00 2001
From: Tue Ly <lntue.h at gmail.com>
Date: Thu, 3 Sep 2026 13:59:59 +0000
Subject: [PATCH 3/3] Keep ASSERT_ERRNO_SUCCESS after invalid tests.
---
libc/test/src/fcntl/posix_fadvise_test.cpp | 3 +++
1 file changed, 3 insertions(+)
diff --git a/libc/test/src/fcntl/posix_fadvise_test.cpp b/libc/test/src/fcntl/posix_fadvise_test.cpp
index a857969f6f4b5..8f50d02ebfce5 100644
--- a/libc/test/src/fcntl/posix_fadvise_test.cpp
+++ b/libc/test/src/fcntl/posix_fadvise_test.cpp
@@ -48,10 +48,12 @@ TEST_F(LlvmLibcPosixFadviseTest, ValidFile) {
// Invalid advice
EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, 0, -1), EINVAL);
+ ASSERT_ERRNO_SUCCESS();
// Negative len
EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(fd, 0, -1, POSIX_FADV_NORMAL),
EINVAL);
+ ASSERT_ERRNO_SUCCESS();
EXPECT_EQ(LIBC_NAMESPACE::close(fd), 0);
}
@@ -65,6 +67,7 @@ TEST_F(LlvmLibcPosixFadviseTest, Pipe) {
ESPIPE);
EXPECT_EQ(LIBC_NAMESPACE::posix_fadvise(pipefd[1], 0, 0, POSIX_FADV_NORMAL),
ESPIPE);
+ ASSERT_ERRNO_SUCCESS();
EXPECT_EQ(LIBC_NAMESPACE::close(pipefd[0]), 0);
EXPECT_EQ(LIBC_NAMESPACE::close(pipefd[1]), 0);
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