[libc-commits] [libc] [libc][sys] add header and functions for sys ipc (PR #182700)
Pengxiang Huang via libc-commits
libc-commits at lists.llvm.org
Fri Feb 27 06:05:08 PST 2026
https://github.com/Pengxiang-Huang updated https://github.com/llvm/llvm-project/pull/182700
>From bb2e8283d3dded9d9001414667cb8f4d9f4d9728 Mon Sep 17 00:00:00 2001
From: Pengxiang Huang <huangpengxiang70 at gmail.com>
Date: Sat, 21 Feb 2026 14:52:40 -0500
Subject: [PATCH 1/3] add the feature libc sys/ipc, add macros, types,
functions, implementation using stat syscall wrapper, target on x86_64 linux,
add one test; used to implement sys/sem in the next pr
---
libc/config/linux/x86_64/entrypoints.txt | 3 +
libc/config/linux/x86_64/headers.txt | 1 +
libc/include/CMakeLists.txt | 15 +++++
libc/include/llvm-libc-macros/CMakeLists.txt | 6 ++
.../llvm-libc-macros/linux/CMakeLists.txt | 6 ++
.../llvm-libc-macros/linux/sys-ipc-macros.h | 24 ++++++++
.../include/llvm-libc-macros/sys-ipc-macros.h | 16 +++++
libc/include/llvm-libc-types/CMakeLists.txt | 9 +++
libc/include/llvm-libc-types/key_t.h | 14 +++++
.../include/llvm-libc-types/struct_ipc_perm.h | 33 +++++++++++
libc/include/sys/ipc.h.def | 18 ++++++
libc/include/sys/ipc.yaml | 19 ++++++
libc/include/sys/types.yaml | 1 +
libc/src/sys/CMakeLists.txt | 1 +
libc/src/sys/ipc/CMakeLists.txt | 10 ++++
libc/src/sys/ipc/ftok.h | 22 +++++++
libc/src/sys/ipc/linux/CMakeLists.txt | 10 ++++
libc/src/sys/ipc/linux/ftok.cpp | 28 +++++++++
libc/test/src/sys/CMakeLists.txt | 1 +
libc/test/src/sys/ipc/CMakeLists.txt | 3 +
libc/test/src/sys/ipc/linux/CMakeLists.txt | 19 ++++++
libc/test/src/sys/ipc/linux/ftok_test.cpp | 59 +++++++++++++++++++
22 files changed, 318 insertions(+)
create mode 100644 libc/include/llvm-libc-macros/linux/sys-ipc-macros.h
create mode 100644 libc/include/llvm-libc-macros/sys-ipc-macros.h
create mode 100644 libc/include/llvm-libc-types/key_t.h
create mode 100644 libc/include/llvm-libc-types/struct_ipc_perm.h
create mode 100644 libc/include/sys/ipc.h.def
create mode 100644 libc/include/sys/ipc.yaml
create mode 100644 libc/src/sys/ipc/CMakeLists.txt
create mode 100644 libc/src/sys/ipc/ftok.h
create mode 100644 libc/src/sys/ipc/linux/CMakeLists.txt
create mode 100644 libc/src/sys/ipc/linux/ftok.cpp
create mode 100644 libc/test/src/sys/ipc/CMakeLists.txt
create mode 100644 libc/test/src/sys/ipc/linux/CMakeLists.txt
create mode 100644 libc/test/src/sys/ipc/linux/ftok_test.cpp
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index 6f0ecf0c6885d..3c5f1c7d55467 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -251,6 +251,9 @@ set(TARGET_LIBC_ENTRYPOINTS
# sys/ioctl.h entrypoints
libc.src.sys.ioctl.ioctl
+ # sys/ipc.h entrypoints
+ libc.src.sys.ipc.ftok
+
# sys/mman.h entrypoints
libc.src.sys.mman.madvise
libc.src.sys.mman.mincore
diff --git a/libc/config/linux/x86_64/headers.txt b/libc/config/linux/x86_64/headers.txt
index d0f62eb104dcc..0669cc30aeadc 100644
--- a/libc/config/linux/x86_64/headers.txt
+++ b/libc/config/linux/x86_64/headers.txt
@@ -38,6 +38,7 @@ set(TARGET_PUBLIC_HEADERS
libc.include.sys_auxv
libc.include.sys_epoll
libc.include.sys_ioctl
+ libc.include.sys_ipc
libc.include.sys_mman
libc.include.sys_prctl
libc.include.sys_queue
diff --git a/libc/include/CMakeLists.txt b/libc/include/CMakeLists.txt
index c6254aafe3849..5ffee68b5feb3 100644
--- a/libc/include/CMakeLists.txt
+++ b/libc/include/CMakeLists.txt
@@ -557,6 +557,20 @@ add_header_macro(
.llvm-libc-macros.sys_ioctl_macros
)
+add_header_macro(
+ sys_ipc
+ ../libc/include/sys/ipc.yaml
+ sys/ipc.h
+ DEPENDS
+ .llvm_libc_common_h
+ .llvm-libc-macros.sys_ipc_macros
+ .llvm-libc-types.key_t
+ .llvm-libc-types.uid_t
+ .llvm-libc-types.gid_t
+ .llvm-libc-types.mode_t
+ .llvm-libc-types.struct_ipc_perm
+)
+
add_header_macro(
sys_mman
../libc/include/sys/mman.yaml
@@ -708,6 +722,7 @@ add_header_macro(
.llvm-libc-types.dev_t
.llvm-libc-types.gid_t
.llvm-libc-types.ino_t
+ .llvm-libc-types.key_t
.llvm-libc-types.mode_t
.llvm-libc-types.nlink_t
.llvm-libc-types.off_t
diff --git a/libc/include/llvm-libc-macros/CMakeLists.txt b/libc/include/llvm-libc-macros/CMakeLists.txt
index b16337cccd58b..553879e27d3d2 100644
--- a/libc/include/llvm-libc-macros/CMakeLists.txt
+++ b/libc/include/llvm-libc-macros/CMakeLists.txt
@@ -226,6 +226,12 @@ add_macro_header(
sys-ioctl-macros.h
)
+add_macro_header(
+ sys_ipc_macros
+ HDR
+ sys-ipc-macros.h
+)
+
add_macro_header(
sys_stat_macros
HDR
diff --git a/libc/include/llvm-libc-macros/linux/CMakeLists.txt b/libc/include/llvm-libc-macros/linux/CMakeLists.txt
index 61da55eabd40b..60376641b50f6 100644
--- a/libc/include/llvm-libc-macros/linux/CMakeLists.txt
+++ b/libc/include/llvm-libc-macros/linux/CMakeLists.txt
@@ -34,6 +34,12 @@ add_header(
sys-ioctl-macros.h
)
+add_header(
+ sys_ipc_macros
+ HDR
+ sys-ipc-macros.h
+)
+
add_header(
sys_random_macros
HDR
diff --git a/libc/include/llvm-libc-macros/linux/sys-ipc-macros.h b/libc/include/llvm-libc-macros/linux/sys-ipc-macros.h
new file mode 100644
index 0000000000000..111f48542c518
--- /dev/null
+++ b/libc/include/llvm-libc-macros/linux/sys-ipc-macros.h
@@ -0,0 +1,24 @@
+//===-- Definition of macros from sys/ipc.h -------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_MACROS_LINUX_SYS_IPC_MACROS_H
+#define LLVM_LIBC_MACROS_LINUX_SYS_IPC_MACROS_H
+
+#define IPC_PRIVATE 0
+
+// Resource get request flags.
+#define IPC_CREAT 00001000
+#define IPC_EXCL 00002000
+#define IPC_NOWAIT 00004000
+
+// Control commands used with semctl, msgctl, and shmctl.
+#define IPC_RMID 0
+#define IPC_SET 1
+#define IPC_STAT 2
+
+#endif // LLVM_LIBC_MACROS_LINUX_SYS_IPC_MACROS_H
diff --git a/libc/include/llvm-libc-macros/sys-ipc-macros.h b/libc/include/llvm-libc-macros/sys-ipc-macros.h
new file mode 100644
index 0000000000000..37e7e45456d2a
--- /dev/null
+++ b/libc/include/llvm-libc-macros/sys-ipc-macros.h
@@ -0,0 +1,16 @@
+//===-- Macros defined in sys/ipc.h header file ---------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_MACROS_SYS_IPC_MACROS_H
+#define LLVM_LIBC_MACROS_SYS_IPC_MACROS_H
+
+#ifdef __linux__
+#include "linux/sys-ipc-macros.h"
+#endif
+
+#endif // LLVM_LIBC_MACROS_SYS_IPC_MACROS_H
diff --git a/libc/include/llvm-libc-types/CMakeLists.txt b/libc/include/llvm-libc-types/CMakeLists.txt
index dc36dfeadba57..52831bf440be7 100644
--- a/libc/include/llvm-libc-types/CMakeLists.txt
+++ b/libc/include/llvm-libc-types/CMakeLists.txt
@@ -44,6 +44,7 @@ add_header(in_addr HDR in_addr.h DEPENDS .in_addr_t)
add_header(ino_t HDR ino_t.h)
add_header(mbstate_t HDR mbstate_t.h)
add_header(mode_t HDR mode_t.h)
+add_header(key_t HDR key_t.h)
add_header(mtx_t HDR mtx_t.h DEPENDS .__futex_word .__mutex_type)
add_header(nfds_t HDR nfds_t.h)
add_header(nl_catd HDR nl_catd.h)
@@ -79,6 +80,14 @@ add_header(dl_info HDR Dl_info.h)
add_header(struct_f_owner_ex HDR struct_f_owner_ex.h DEPENDS .pid_t)
add_header(struct_flock HDR struct_flock.h DEPENDS .off_t .pid_t)
add_header(struct_flock64 HDR struct_flock64.h DEPENDS .off64_t .pid_t)
+add_header(
+ struct_ipc_perm
+ HDR struct_ipc_perm.h
+ DEPENDS
+ .key_t
+ .uid_t
+ .gid_t
+)
add_header(struct_pollfd HDR struct_pollfd.h)
add_header(struct_rlimit HDR struct_rlimit.h DEPENDS .rlim_t)
add_header(struct_sched_param HDR struct_sched_param.h)
diff --git a/libc/include/llvm-libc-types/key_t.h b/libc/include/llvm-libc-types/key_t.h
new file mode 100644
index 0000000000000..1515469880862
--- /dev/null
+++ b/libc/include/llvm-libc-types/key_t.h
@@ -0,0 +1,14 @@
+//===-- Definition of key_t type ------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_TYPES_KEY_T_H
+#define LLVM_LIBC_TYPES_KEY_T_H
+
+typedef __INT32_TYPE__ key_t;
+
+#endif // LLVM_LIBC_TYPES_KEY_T_H
diff --git a/libc/include/llvm-libc-types/struct_ipc_perm.h b/libc/include/llvm-libc-types/struct_ipc_perm.h
new file mode 100644
index 0000000000000..60c021cd5a1cf
--- /dev/null
+++ b/libc/include/llvm-libc-types/struct_ipc_perm.h
@@ -0,0 +1,33 @@
+//===-- Definition of struct ipc_perm -------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_TYPES_STRUCT_IPC_PERM_H
+#define LLVM_LIBC_TYPES_STRUCT_IPC_PERM_H
+
+#include "gid_t.h"
+#include "key_t.h"
+#include "uid_t.h"
+
+#ifdef __linux__
+struct ipc_perm {
+ key_t __key;
+ uid_t uid;
+ gid_t gid;
+ uid_t cuid;
+ gid_t cgid;
+ unsigned short mode;
+ unsigned short seq;
+ unsigned short padding;
+ unsigned long unused_0;
+ unsigned long unused_1;
+};
+#else
+#error "ipc_perm not defined for the target platform"
+#endif
+
+#endif // LLVM_LIBC_TYPES_STRUCT_IPC_PERM_H
diff --git a/libc/include/sys/ipc.h.def b/libc/include/sys/ipc.h.def
new file mode 100644
index 0000000000000..8688bad8a1159
--- /dev/null
+++ b/libc/include/sys/ipc.h.def
@@ -0,0 +1,18 @@
+//===-- Linux header sys/ipc.h --------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SYS_IPC_H
+#define LLVM_LIBC_SYS_IPC_H
+
+#include "__llvm-libc-common.h"
+
+#include "../llvm-libc-macros/sys-ipc-macros.h"
+
+%%public_api()
+
+#endif // LLVM_LIBC_SYS_IPC_H
diff --git a/libc/include/sys/ipc.yaml b/libc/include/sys/ipc.yaml
new file mode 100644
index 0000000000000..172f5f64a3398
--- /dev/null
+++ b/libc/include/sys/ipc.yaml
@@ -0,0 +1,19 @@
+header: sys/ipc.h
+header_template: ipc.h.def
+standards:
+ - Linux
+types:
+ - type_name: key_t
+ - type_name: uid_t
+ - type_name: gid_t
+ - type_name: struct_ipc_perm
+functions:
+ - name: ftok
+ standards:
+ - Linux
+ return_type: key_t
+ arguments:
+ - type: const char *
+ - type: int
+enums: []
+objects: []
diff --git a/libc/include/sys/types.yaml b/libc/include/sys/types.yaml
index a00429d3817e1..126c597b30353 100644
--- a/libc/include/sys/types.yaml
+++ b/libc/include/sys/types.yaml
@@ -8,6 +8,7 @@ types:
- type_name: dev_t
- type_name: gid_t
- type_name: ino_t
+ - type_name: key_t
- type_name: mode_t
- type_name: nlink_t
- type_name: off_t
diff --git a/libc/src/sys/CMakeLists.txt b/libc/src/sys/CMakeLists.txt
index 0fa11e9eee696..1c17ec31a8592 100644
--- a/libc/src/sys/CMakeLists.txt
+++ b/libc/src/sys/CMakeLists.txt
@@ -1,5 +1,6 @@
add_subdirectory(auxv)
add_subdirectory(epoll)
+add_subdirectory(ipc)
add_subdirectory(mman)
add_subdirectory(random)
add_subdirectory(resource)
diff --git a/libc/src/sys/ipc/CMakeLists.txt b/libc/src/sys/ipc/CMakeLists.txt
new file mode 100644
index 0000000000000..e20ac7e3f964e
--- /dev/null
+++ b/libc/src/sys/ipc/CMakeLists.txt
@@ -0,0 +1,10 @@
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+ add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+endif()
+
+add_entrypoint_object(
+ ftok
+ ALIAS
+ DEPENDS
+ .${LIBC_TARGET_OS}.ftok
+)
diff --git a/libc/src/sys/ipc/ftok.h b/libc/src/sys/ipc/ftok.h
new file mode 100644
index 0000000000000..6b9d0fa40b028
--- /dev/null
+++ b/libc/src/sys/ipc/ftok.h
@@ -0,0 +1,22 @@
+//===-- Implementation header for ftok ---------------------------*- C++
+//-*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SYS_IPC_FTOK_H
+#define LLVM_LIBC_SRC_SYS_IPC_FTOK_H
+
+#include "src/__support/macros/config.h"
+#include <sys/ipc.h>
+
+namespace LIBC_NAMESPACE_DECL {
+
+key_t ftok(const char *path, int id);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_SYS_IPC_FTOK_H
diff --git a/libc/src/sys/ipc/linux/CMakeLists.txt b/libc/src/sys/ipc/linux/CMakeLists.txt
new file mode 100644
index 0000000000000..c2fdebcf989dc
--- /dev/null
+++ b/libc/src/sys/ipc/linux/CMakeLists.txt
@@ -0,0 +1,10 @@
+add_entrypoint_object(
+ ftok
+ SRCS
+ ftok.cpp
+ HDRS
+ ../ftok.h
+ DEPENDS
+ libc.include.sys_ipc
+ libc.src.sys.stat.stat
+)
diff --git a/libc/src/sys/ipc/linux/ftok.cpp b/libc/src/sys/ipc/linux/ftok.cpp
new file mode 100644
index 0000000000000..6d0920c77ced3
--- /dev/null
+++ b/libc/src/sys/ipc/linux/ftok.cpp
@@ -0,0 +1,28 @@
+//===-- Linux implementation of ftok -------------------------------------===//
+//
+// 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/sys/ipc/ftok.h"
+
+#include "src/__support/common.h"
+#include "src/sys/stat/stat.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(key_t, ftok, (const char *path, int id)) {
+
+ // ftok implements based on stat
+ struct stat st;
+ if (LIBC_NAMESPACE::stat(path, &st) < 0)
+ return -1;
+
+ return static_cast<key_t>(((id & 0xff) << 24) |
+ ((static_cast<int>(st.st_dev) & 0xff) << 16) |
+ (static_cast<int>(st.st_ino) & 0xffff));
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/test/src/sys/CMakeLists.txt b/libc/test/src/sys/CMakeLists.txt
index 13bf91eef04be..3b5ea64fb1448 100644
--- a/libc/test/src/sys/CMakeLists.txt
+++ b/libc/test/src/sys/CMakeLists.txt
@@ -11,6 +11,7 @@ add_subdirectory(wait)
add_subdirectory(prctl)
add_subdirectory(auxv)
add_subdirectory(epoll)
+add_subdirectory(ipc)
add_subdirectory(uio)
add_subdirectory(time)
add_subdirectory(ioctl)
diff --git a/libc/test/src/sys/ipc/CMakeLists.txt b/libc/test/src/sys/ipc/CMakeLists.txt
new file mode 100644
index 0000000000000..b4bbe81c92ff2
--- /dev/null
+++ b/libc/test/src/sys/ipc/CMakeLists.txt
@@ -0,0 +1,3 @@
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+ add_subdirectory(${LIBC_TARGET_OS})
+endif()
diff --git a/libc/test/src/sys/ipc/linux/CMakeLists.txt b/libc/test/src/sys/ipc/linux/CMakeLists.txt
new file mode 100644
index 0000000000000..21d501a3029ef
--- /dev/null
+++ b/libc/test/src/sys/ipc/linux/CMakeLists.txt
@@ -0,0 +1,19 @@
+add_custom_target(libc_sys_ipc_unittests)
+
+add_libc_unittest(
+ ftok_test
+ SUITE
+ libc_sys_ipc_unittests
+ SRCS
+ ftok_test.cpp
+ DEPENDS
+ libc.hdr.fcntl_macros
+ libc.include.sys_ipc
+ libc.src.errno.errno
+ libc.src.fcntl.open
+ libc.src.sys.ipc.ftok
+ libc.src.unistd.close
+ libc.src.unistd.unlink
+ libc.test.UnitTest.ErrnoCheckingTest
+ libc.test.UnitTest.ErrnoSetterMatcher
+)
diff --git a/libc/test/src/sys/ipc/linux/ftok_test.cpp b/libc/test/src/sys/ipc/linux/ftok_test.cpp
new file mode 100644
index 0000000000000..dd9a4702d439b
--- /dev/null
+++ b/libc/test/src/sys/ipc/linux/ftok_test.cpp
@@ -0,0 +1,59 @@
+//===-- Unittests for ftok ------------------------------------------------===//
+//
+// 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/fcntl/open.h"
+#include "src/sys/ipc/ftok.h"
+#include "src/unistd/close.h"
+#include "src/unistd/unlink.h"
+#include "test/UnitTest/ErrnoCheckingTest.h"
+#include "test/UnitTest/ErrnoSetterMatcher.h"
+#include "test/UnitTest/Test.h"
+
+#include "hdr/fcntl_macros.h"
+
+using namespace LIBC_NAMESPACE::testing::ErrnoSetterMatcher;
+using LlvmLibcFtokTest = LIBC_NAMESPACE::testing::ErrnoCheckingTest;
+
+TEST_F(LlvmLibcFtokTest, InvalidPath) {
+ ASSERT_THAT(LIBC_NAMESPACE::ftok("no/such/path", 1), Fails(ENOENT));
+}
+
+TEST_F(LlvmLibcFtokTest, DeterministicForPathAndId) {
+ // create a file
+ constexpr const char *TEST_FILE_NAME = "ftok.test";
+ auto TEST_FILE = libc_make_test_file_path(TEST_FILE_NAME);
+
+ // we first ensure such file exist and set to readable, writable
+ int fd = LIBC_NAMESPACE::open(TEST_FILE, O_CREAT | O_WRONLY, 0600);
+ ASSERT_GT(fd, -1);
+ ASSERT_ERRNO_SUCCESS();
+ ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
+
+ // create keys based on file path and user specified int
+ key_t key1 = LIBC_NAMESPACE::ftok(TEST_FILE, 'A');
+ ASSERT_NE(key1, key_t(-1));
+ ASSERT_ERRNO_SUCCESS();
+
+ key_t key2 = LIBC_NAMESPACE::ftok(TEST_FILE, 'A');
+ ASSERT_NE(key2, key_t(-1));
+ ASSERT_ERRNO_SUCCESS();
+
+ // key should be identical if both inputs are the same
+ ASSERT_EQ(key1, key2);
+
+ // create another key
+ key_t key3 = LIBC_NAMESPACE::ftok(TEST_FILE, 'B');
+ ASSERT_NE(key3, key_t(-1));
+ ASSERT_ERRNO_SUCCESS();
+
+ // key should be different if any input is different
+ ASSERT_NE(key1, key3);
+
+ // delete the file
+ ASSERT_THAT(LIBC_NAMESPACE::unlink(TEST_FILE), Succeeds(0));
+}
>From 9192546cf8f3bab9f806719c6b0e55841d243d8a Mon Sep 17 00:00:00 2001
From: Pengxiang Huang <huangpengxiang70 at gmail.com>
Date: Tue, 24 Feb 2026 15:59:03 -0500
Subject: [PATCH 2/3] [libc][sys] fix the issues reviewer points out
type mode change to mode_t; remove header templates for ipc.h, add the macros in the yaml; change the standards to posix
add the proxy type for key_t in hdr/, change the implementation of ftok, now it wraps the syscall of statx, implementation is basically the same as sys/stat
---
libc/hdr/types/CMakeLists.txt | 9 +++
libc/hdr/types/key_t.h | 22 +++++
.../llvm-libc-macros/linux/sys-ipc-macros.h | 6 +-
libc/include/llvm-libc-types/CMakeLists.txt | 2 +-
.../include/llvm-libc-types/struct_ipc_perm.h | 3 +-
libc/include/sys/ipc.h.def | 18 -----
libc/include/sys/ipc.yaml | 42 ++++++++--
libc/src/sys/ipc/ftok.h | 2 +-
libc/src/sys/ipc/linux/CMakeLists.txt | 18 ++++-
libc/src/sys/ipc/linux/ftok.cpp | 21 ++---
libc/src/sys/ipc/linux/kernel_statx.h | 80 +++++++++++++++++++
11 files changed, 183 insertions(+), 40 deletions(-)
create mode 100644 libc/hdr/types/key_t.h
delete mode 100644 libc/include/sys/ipc.h.def
create mode 100644 libc/src/sys/ipc/linux/kernel_statx.h
diff --git a/libc/hdr/types/CMakeLists.txt b/libc/hdr/types/CMakeLists.txt
index 3385fe81fe223..03e7066f83a03 100644
--- a/libc/hdr/types/CMakeLists.txt
+++ b/libc/hdr/types/CMakeLists.txt
@@ -233,6 +233,15 @@ add_proxy_header_library(
libc.include.sys_time
)
+add_proxy_header_library(
+ key_t
+ HDRS
+ key_t.h
+ FULL_BUILD_DEPENDS
+ libc.include.llvm-libc-types.key_t
+ libc.include.sys_ipc
+)
+
add_proxy_header_library(
pid_t
HDRS
diff --git a/libc/hdr/types/key_t.h b/libc/hdr/types/key_t.h
new file mode 100644
index 0000000000000..478522a93a196
--- /dev/null
+++ b/libc/hdr/types/key_t.h
@@ -0,0 +1,22 @@
+//===-- Proxy for key_t ---------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_HDR_TYPES_KEY_T_H
+#define LLVM_LIBC_HDR_TYPES_KEY_T_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-types/key_t.h"
+
+#else // Overlay mode
+
+#include <sys/ipc.h>
+
+#endif // LLVM_LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_TYPES_KEY_T_H
diff --git a/libc/include/llvm-libc-macros/linux/sys-ipc-macros.h b/libc/include/llvm-libc-macros/linux/sys-ipc-macros.h
index 111f48542c518..87546ac314d83 100644
--- a/libc/include/llvm-libc-macros/linux/sys-ipc-macros.h
+++ b/libc/include/llvm-libc-macros/linux/sys-ipc-macros.h
@@ -12,9 +12,9 @@
#define IPC_PRIVATE 0
// Resource get request flags.
-#define IPC_CREAT 00001000
-#define IPC_EXCL 00002000
-#define IPC_NOWAIT 00004000
+#define IPC_CREAT 01000
+#define IPC_EXCL 02000
+#define IPC_NOWAIT 04000
// Control commands used with semctl, msgctl, and shmctl.
#define IPC_RMID 0
diff --git a/libc/include/llvm-libc-types/CMakeLists.txt b/libc/include/llvm-libc-types/CMakeLists.txt
index 52831bf440be7..18c43c6a4a366 100644
--- a/libc/include/llvm-libc-types/CMakeLists.txt
+++ b/libc/include/llvm-libc-types/CMakeLists.txt
@@ -42,9 +42,9 @@ add_header(imaxdiv_t HDR imaxdiv_t.h)
add_header(in_addr_t HDR in_addr_t.h)
add_header(in_addr HDR in_addr.h DEPENDS .in_addr_t)
add_header(ino_t HDR ino_t.h)
+add_header(key_t HDR key_t.h)
add_header(mbstate_t HDR mbstate_t.h)
add_header(mode_t HDR mode_t.h)
-add_header(key_t HDR key_t.h)
add_header(mtx_t HDR mtx_t.h DEPENDS .__futex_word .__mutex_type)
add_header(nfds_t HDR nfds_t.h)
add_header(nl_catd HDR nl_catd.h)
diff --git a/libc/include/llvm-libc-types/struct_ipc_perm.h b/libc/include/llvm-libc-types/struct_ipc_perm.h
index 60c021cd5a1cf..e9f02da2585c9 100644
--- a/libc/include/llvm-libc-types/struct_ipc_perm.h
+++ b/libc/include/llvm-libc-types/struct_ipc_perm.h
@@ -11,6 +11,7 @@
#include "gid_t.h"
#include "key_t.h"
+#include "mode_t.h"
#include "uid_t.h"
#ifdef __linux__
@@ -20,7 +21,7 @@ struct ipc_perm {
gid_t gid;
uid_t cuid;
gid_t cgid;
- unsigned short mode;
+ mode_t mode;
unsigned short seq;
unsigned short padding;
unsigned long unused_0;
diff --git a/libc/include/sys/ipc.h.def b/libc/include/sys/ipc.h.def
deleted file mode 100644
index 8688bad8a1159..0000000000000
--- a/libc/include/sys/ipc.h.def
+++ /dev/null
@@ -1,18 +0,0 @@
-//===-- Linux header sys/ipc.h --------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_LIBC_SYS_IPC_H
-#define LLVM_LIBC_SYS_IPC_H
-
-#include "__llvm-libc-common.h"
-
-#include "../llvm-libc-macros/sys-ipc-macros.h"
-
-%%public_api()
-
-#endif // LLVM_LIBC_SYS_IPC_H
diff --git a/libc/include/sys/ipc.yaml b/libc/include/sys/ipc.yaml
index 172f5f64a3398..77593af1dc0a6 100644
--- a/libc/include/sys/ipc.yaml
+++ b/libc/include/sys/ipc.yaml
@@ -1,19 +1,51 @@
header: sys/ipc.h
-header_template: ipc.h.def
standards:
- - Linux
+ - posix
+ - linux
+macros:
+ - macro_name: IPC_PRIVATE
+ macro_header: sys-ipc-macros.h
+ standards:
+ - posix
+ - macro_name: IPC_CREAT
+ macro_header: sys-ipc-macros.h
+ standards:
+ - posix
+ - macro_name: IPC_EXCL
+ macro_header: sys-ipc-macros.h
+ standards:
+ - posix
+ - macro_name: IPC_NOWAIT
+ macro_header: sys-ipc-macros.h
+ standards:
+ - posix
+ - macro_name: IPC_RMID
+ macro_header: sys-ipc-macros.h
+ standards:
+ - posix
+ - macro_name: IPC_SET
+ macro_header: sys-ipc-macros.h
+ standards:
+ - posix
+ - macro_name: IPC_STAT
+ macro_header: sys-ipc-macros.h
+ standards:
+ - posix
+ - macro_name: IPC_INFO
+ macro_header: sys-ipc-macros.h
+ standards:
+ - linux
types:
- type_name: key_t
- type_name: uid_t
- type_name: gid_t
+ - type_name: mode_t
- type_name: struct_ipc_perm
functions:
- name: ftok
standards:
- - Linux
+ - posix
return_type: key_t
arguments:
- type: const char *
- type: int
-enums: []
-objects: []
diff --git a/libc/src/sys/ipc/ftok.h b/libc/src/sys/ipc/ftok.h
index 6b9d0fa40b028..91203c78610b9 100644
--- a/libc/src/sys/ipc/ftok.h
+++ b/libc/src/sys/ipc/ftok.h
@@ -10,8 +10,8 @@
#ifndef LLVM_LIBC_SRC_SYS_IPC_FTOK_H
#define LLVM_LIBC_SRC_SYS_IPC_FTOK_H
+#include "hdr/types/key_t.h"
#include "src/__support/macros/config.h"
-#include <sys/ipc.h>
namespace LIBC_NAMESPACE_DECL {
diff --git a/libc/src/sys/ipc/linux/CMakeLists.txt b/libc/src/sys/ipc/linux/CMakeLists.txt
index c2fdebcf989dc..526cdb7324e02 100644
--- a/libc/src/sys/ipc/linux/CMakeLists.txt
+++ b/libc/src/sys/ipc/linux/CMakeLists.txt
@@ -1,3 +1,15 @@
+add_header_library(
+ kernel_statx
+ HDRS
+ kernel_statx.h
+ DEPENDS
+ libc.hdr.fcntl_macros
+ libc.hdr.stdint_proxy
+ libc.include.sys_syscall
+ libc.src.__support.OSUtil.osutil
+ libc.src.__support.common
+)
+
add_entrypoint_object(
ftok
SRCS
@@ -5,6 +17,8 @@ add_entrypoint_object(
HDRS
../ftok.h
DEPENDS
- libc.include.sys_ipc
- libc.src.sys.stat.stat
+ .kernel_statx
+ libc.hdr.types.key_t
+ libc.src.__support.common
+ libc.src.errno.errno
)
diff --git a/libc/src/sys/ipc/linux/ftok.cpp b/libc/src/sys/ipc/linux/ftok.cpp
index 6d0920c77ced3..5e2069a11f4d4 100644
--- a/libc/src/sys/ipc/linux/ftok.cpp
+++ b/libc/src/sys/ipc/linux/ftok.cpp
@@ -5,24 +5,27 @@
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
-
#include "src/sys/ipc/ftok.h"
#include "src/__support/common.h"
-#include "src/sys/stat/stat.h"
+#include "src/__support/libc_errno.h"
+
+#include "kernel_statx.h"
namespace LIBC_NAMESPACE_DECL {
LLVM_LIBC_FUNCTION(key_t, ftok, (const char *path, int id)) {
-
- // ftok implements based on stat
- struct stat st;
- if (LIBC_NAMESPACE::stat(path, &st) < 0)
+ ::statx_buf xbuf;
+ int err = statx_for_ftok(path, xbuf);
+ if (err != 0) {
+ libc_errno = err;
return -1;
+ }
- return static_cast<key_t>(((id & 0xff) << 24) |
- ((static_cast<int>(st.st_dev) & 0xff) << 16) |
- (static_cast<int>(st.st_ino) & 0xffff));
+ return static_cast<key_t>(
+ ((id & 0xff) << 24) |
+ ((static_cast<int>(xbuf.stx_dev_minor) & 0xff) << 16) |
+ (static_cast<int>(xbuf.stx_ino) & 0xffff));
}
} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/sys/ipc/linux/kernel_statx.h b/libc/src/sys/ipc/linux/kernel_statx.h
new file mode 100644
index 0000000000000..59346a307c8c2
--- /dev/null
+++ b/libc/src/sys/ipc/linux/kernel_statx.h
@@ -0,0 +1,80 @@
+//===-- Wrapper over SYS_statx syscall for ftok ---------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SYS_IPC_LINUX_KERNEL_STATX_H
+#define LLVM_LIBC_SRC_SYS_IPC_LINUX_KERNEL_STATX_H
+
+#include "hdr/fcntl_macros.h"
+#include "hdr/stdint_proxy.h"
+#include "src/__support/OSUtil/syscall.h"
+#include "src/__support/common.h"
+#include "sys/syscall.h"
+
+// this namespace is copied from the sys/stat/linux/kernel_statx.cpp
+namespace {
+
+// The type definitions in the internal namespace match kernel's definition of
+// the statx_timestamp and statx types in linux/stat.h. We define equivalent
+// types here instead of including that header file to avoid name mixup between
+// linux/stat.h and the libc's stat.h.
+struct statx_timestamp {
+ int64_t tv_sec;
+ uint32_t tv_nsec;
+ int32_t __reserved;
+};
+
+struct statx_buf {
+ uint32_t stx_mask; // What results were written
+ uint32_t stx_blksize; // Preferred general I/O size
+ uint64_t stx_attributes; // Flags conveying information about the file
+ uint32_t stx_nlink; // Number of hard links
+ uint32_t stx_uid; // User ID of owner
+ uint32_t stx_gid; // Group ID of owner
+ uint16_t stx_mode; // File mode
+ uint16_t __spare0[1];
+ uint64_t stx_ino; // Inode number
+ uint64_t stx_size; // File size
+ uint64_t stx_blocks; // Number of 512-byte blocks allocated
+ uint64_t stx_attributes_mask; // Mask to show what's supported in
+ // stx_attributes
+ struct statx_timestamp stx_atime; // Last access time
+ struct statx_timestamp stx_btime; // File creation time
+ struct statx_timestamp stx_ctime; // Last attribute change time
+ struct statx_timestamp stx_mtime; // Last data modification time
+ uint32_t stx_rdev_major; // Device ID of special file
+ uint32_t stx_rdev_minor;
+ uint32_t stx_dev_major; // ID of device containing file
+ uint32_t stx_dev_minor;
+ uint64_t stx_mnt_id;
+ uint64_t __spare2;
+ uint64_t __spare3[12]; // Spare space for future expansion
+};
+
+// The below mask value is based on the definition of a similarly
+// named macro in linux/stat.h. When this flag is passed for the
+// mask argument to the statx syscall, all fields except the
+// stx_btime field will be filled in.
+constexpr unsigned int STATX_BASIC_STATS_MASK = 0x7FF;
+
+} // Anonymous namespace
+
+namespace LIBC_NAMESPACE_DECL {
+
+LIBC_INLINE int statx_for_ftok(const char *path, ::statx_buf &xbuf) {
+
+ int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_statx, AT_FDCWD, path, 0,
+ ::STATX_BASIC_STATS_MASK, &xbuf);
+
+ if (ret < 0)
+ return -ret;
+ return 0;
+}
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_SYS_IPC_LINUX_KERNEL_STATX_H
>From 63cb343c09b38be0f1da10ba0f5a45f530da0259 Mon Sep 17 00:00:00 2001
From: Pengxiang Huang <huangpengxiang70 at gmail.com>
Date: Fri, 27 Feb 2026 09:04:52 -0500
Subject: [PATCH 3/3] resolve reviewers comments
remove the statx required data structures; directly use those in linux uapi.
add comments for returned key_t layouts in ftok
---
libc/src/sys/ipc/linux/CMakeLists.txt | 2 -
libc/src/sys/ipc/linux/ftok.cpp | 8 +++-
libc/src/sys/ipc/linux/kernel_statx.h | 55 ++-------------------------
3 files changed, 11 insertions(+), 54 deletions(-)
diff --git a/libc/src/sys/ipc/linux/CMakeLists.txt b/libc/src/sys/ipc/linux/CMakeLists.txt
index 526cdb7324e02..0a27e9b4665f8 100644
--- a/libc/src/sys/ipc/linux/CMakeLists.txt
+++ b/libc/src/sys/ipc/linux/CMakeLists.txt
@@ -4,10 +4,8 @@ add_header_library(
kernel_statx.h
DEPENDS
libc.hdr.fcntl_macros
- libc.hdr.stdint_proxy
libc.include.sys_syscall
libc.src.__support.OSUtil.osutil
- libc.src.__support.common
)
add_entrypoint_object(
diff --git a/libc/src/sys/ipc/linux/ftok.cpp b/libc/src/sys/ipc/linux/ftok.cpp
index 5e2069a11f4d4..41c5aad0314d5 100644
--- a/libc/src/sys/ipc/linux/ftok.cpp
+++ b/libc/src/sys/ipc/linux/ftok.cpp
@@ -15,13 +15,19 @@
namespace LIBC_NAMESPACE_DECL {
LLVM_LIBC_FUNCTION(key_t, ftok, (const char *path, int id)) {
- ::statx_buf xbuf;
+ struct statx xbuf;
+
int err = statx_for_ftok(path, xbuf);
+
if (err != 0) {
libc_errno = err;
return -1;
}
+ // key layout based on user input and file stats metadata
+ // 31 24 16 0
+ // +-------------+---------------+--------------+
+ // user input id + minor dev num + file inode num
return static_cast<key_t>(
((id & 0xff) << 24) |
((static_cast<int>(xbuf.stx_dev_minor) & 0xff) << 16) |
diff --git a/libc/src/sys/ipc/linux/kernel_statx.h b/libc/src/sys/ipc/linux/kernel_statx.h
index 59346a307c8c2..3d6847a7b2e67 100644
--- a/libc/src/sys/ipc/linux/kernel_statx.h
+++ b/libc/src/sys/ipc/linux/kernel_statx.h
@@ -10,65 +10,18 @@
#define LLVM_LIBC_SRC_SYS_IPC_LINUX_KERNEL_STATX_H
#include "hdr/fcntl_macros.h"
-#include "hdr/stdint_proxy.h"
#include "src/__support/OSUtil/syscall.h"
-#include "src/__support/common.h"
#include "sys/syscall.h"
-// this namespace is copied from the sys/stat/linux/kernel_statx.cpp
-namespace {
-
-// The type definitions in the internal namespace match kernel's definition of
-// the statx_timestamp and statx types in linux/stat.h. We define equivalent
-// types here instead of including that header file to avoid name mixup between
-// linux/stat.h and the libc's stat.h.
-struct statx_timestamp {
- int64_t tv_sec;
- uint32_t tv_nsec;
- int32_t __reserved;
-};
-
-struct statx_buf {
- uint32_t stx_mask; // What results were written
- uint32_t stx_blksize; // Preferred general I/O size
- uint64_t stx_attributes; // Flags conveying information about the file
- uint32_t stx_nlink; // Number of hard links
- uint32_t stx_uid; // User ID of owner
- uint32_t stx_gid; // Group ID of owner
- uint16_t stx_mode; // File mode
- uint16_t __spare0[1];
- uint64_t stx_ino; // Inode number
- uint64_t stx_size; // File size
- uint64_t stx_blocks; // Number of 512-byte blocks allocated
- uint64_t stx_attributes_mask; // Mask to show what's supported in
- // stx_attributes
- struct statx_timestamp stx_atime; // Last access time
- struct statx_timestamp stx_btime; // File creation time
- struct statx_timestamp stx_ctime; // Last attribute change time
- struct statx_timestamp stx_mtime; // Last data modification time
- uint32_t stx_rdev_major; // Device ID of special file
- uint32_t stx_rdev_minor;
- uint32_t stx_dev_major; // ID of device containing file
- uint32_t stx_dev_minor;
- uint64_t stx_mnt_id;
- uint64_t __spare2;
- uint64_t __spare3[12]; // Spare space for future expansion
-};
-
-// The below mask value is based on the definition of a similarly
-// named macro in linux/stat.h. When this flag is passed for the
-// mask argument to the statx syscall, all fields except the
-// stx_btime field will be filled in.
-constexpr unsigned int STATX_BASIC_STATS_MASK = 0x7FF;
-
-} // Anonymous namespace
+#include <linux/stat.h>
namespace LIBC_NAMESPACE_DECL {
-LIBC_INLINE int statx_for_ftok(const char *path, ::statx_buf &xbuf) {
+LIBC_INLINE int statx_for_ftok(const char *path, struct statx &xbuf) {
+ // store the file stats metadata into xbuf
int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_statx, AT_FDCWD, path, 0,
- ::STATX_BASIC_STATS_MASK, &xbuf);
+ STATX_BASIC_STATS, &xbuf);
if (ret < 0)
return -ret;
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