[libc] Implement fcntl() function (#89507)

Fixes #84968. 

Implements the `fcntl()` function defined in the `fcntl.h` header.

Author: vinayakdsci

libc/config/linux/aarch64/entrypoints.txt

@@ -22,6 +22,7 @@ set(TARGET_LIBC_ENTRYPOINTS
 
     # fcntl.h entrypoints
     libc.src.fcntl.creat
+    libc.src.fcntl.fcntl
     libc.src.fcntl.open
     libc.src.fcntl.openat
 

libc/config/linux/riscv/entrypoints.txt

@@ -22,6 +22,7 @@ set(TARGET_LIBC_ENTRYPOINTS
 
     # fcntl.h entrypoints
     libc.src.fcntl.creat
+    libc.src.fcntl.fcntl
     libc.src.fcntl.open
     libc.src.fcntl.openat
 

libc/config/linux/x86_64/entrypoints.txt

@@ -22,6 +22,7 @@ set(TARGET_LIBC_ENTRYPOINTS
 
     # fcntl.h entrypoints
     libc.src.fcntl.creat
+    libc.src.fcntl.fcntl
     libc.src.fcntl.open
     libc.src.fcntl.openat
 

libc/hdr/CMakeLists.txt

@@ -32,6 +32,15 @@ add_proxy_header_library(
     libc.include.math
 )
 
+add_proxy_header_library(
+  fcntl_macros
+  HDRS
+    fcntl_macros.h
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-macros.fcntl_macros
+    libc.include.fcntl
+)
+
 add_proxy_header_library(
   fenv_macros
   HDRS

libc/hdr/fcntl_macros.h

@@ -0,0 +1,22 @@
+//===-- Definition of macros from fcntl/fcntl.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_HDR_FCNTL_MACROS_H
+#define LLVM_LIBC_HDR_FCNTL_MACROS_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-macros/fcntl-macros.h"
+
+#else // Overlay mode
+
+#include <fcntl.h>
+
+#endif // LLVM_LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_FCNTL_MACROS_H

libc/hdr/types/CMakeLists.txt

@@ -14,6 +14,30 @@ add_proxy_header_library(
     libc.include.llvm-libc-types.struct_epoll_event
 )
 
+add_proxy_header_library(
+  struct_flock
+  HDRS
+    struct_flock.h
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-types.struct_flock
+)
+
+add_proxy_header_library(
+  struct_flock64
+  HDRS
+    struct_flock64.h
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-types.struct_flock64
+)
+
+add_proxy_header_library(
+  struct_f_owner_ex
+  HDRS
+    struct_f_owner_ex.h
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-types.struct_f_owner_ex
+)
+
 add_proxy_header_library(
   struct_timespec
   HDRS

libc/hdr/types/struct_f_owner_ex.h

@@ -0,0 +1,21 @@
+//===-- Proxy for struct f_owner_ex  --------------------------------------===//
+//
+// 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_STRUCT_F_OWNER_EX_H
+#define LLVM_LIBC_HDR_TYPES_STRUCT_F_OWNER_EX_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-types/struct_f_owner_ex.h"
+
+#else
+
+#include <fcntl.h>
+
+#endif // LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_TYPES_STRUCT_F_OWNER_EX_H

libc/hdr/types/struct_flock.h

@@ -0,0 +1,21 @@
+//===-- Proxy for struct flock  -------------------------------------------===//
+//
+// 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_STRUCT_FLOCK_H
+#define LLVM_LIBC_HDR_TYPES_STRUCT_FLOCK_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-types/struct_flock.h"
+
+#else
+
+#include <fcntl.h>
+
+#endif // LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_TYPES_STRUCT_FLOCK_H

libc/hdr/types/struct_flock64.h

@@ -0,0 +1,21 @@
+//===-- Proxy for struct flock64  -----------------------------------------===//
+//
+// 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_STRUCT_FLOCK64_H
+#define LLVM_LIBC_HDR_TYPES_STRUCT_FLOCK64_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-types/struct_flock64.h"
+
+#else
+
+#include <fcntl.h>
+
+#endif // LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_TYPES_STRUCT_FLOCK64_H

libc/include/CMakeLists.txt

@@ -43,6 +43,10 @@ add_gen_header(
   DEPENDS
     .llvm-libc-macros.fcntl_macros
     .llvm-libc-types.mode_t
+    .llvm-libc-types.struct_flock
+    .llvm-libc-types.struct_flock64
+    .llvm-libc-types.off64_t
+    .llvm-libc-types.pid_t
     .llvm-libc-types.off_t
     .llvm_libc_common_h
 )

libc/include/llvm-libc-macros/linux/fcntl-macros.h

@@ -67,5 +67,36 @@
 #define F_SETFD 2
 #define F_GETFL 3
 #define F_SETFL 4
+#define F_GETLK 5
+#define F_SETLK 6
+#define F_SETLKW 7
+#define F_SETOWN 8
+#define F_GETOWN 9
+#define F_SETSIG 10
+#define F_GETSIG 11
+#define F_GETLK64 12
+#define F_SETLK64 13
+#define F_SETLKW64 14
+#define F_SETOWN_EX 15
+#define F_GETOWN_EX 16
+
+// Open File Description Locks.
+#define F_OFD_GETLK 36
+#define F_OFD_SETLK 37
+#define F_OFD_SETLKW 38
+
+// Close on succesful
+#define F_CLOEXEC 1
+
+#define F_RDLCK 0
+#define F_WRLCK 1
+#define F_UNLCK 2
+
+// For Large File Support
+#if defined(_LARGEFILE64_SOURCE)
+#define F_GETLK F_GETLK64
+#define F_SETLK F_SETLK64
+#define F_SETLKW F_SETLKW64
+#endif
 
 #endif // LLVM_LIBC_MACROS_LINUX_FCNTL_MACROS_H

libc/include/llvm-libc-types/CMakeLists.txt

@@ -60,6 +60,9 @@ add_header(rlim_t HDR rlim_t.h)
 add_header(time_t HDR time_t.h)
 add_header(stack_t HDR stack_t.h)
 add_header(suseconds_t HDR suseconds_t.h)
+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_f_owner_ex HDR struct_f_owner_ex.h DEPENDS .pid_t)
 add_header(struct_timeval HDR struct_timeval.h DEPENDS .suseconds_t .time_t)
 add_header(struct_rlimit HDR struct_rlimit.h DEPENDS .rlim_t)
 add_header(struct_rusage HDR struct_rusage.h DEPENDS .struct_timeval)

libc/include/llvm-libc-types/struct_f_owner_ex.h

@@ -0,0 +1,25 @@
+//===-- Definition of type struct f_owner_ex ------------------------------===//
+//
+// 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_F_OWNER_EX_H
+#define LLVM_LIBC_TYPES_STRUCT_F_OWNER_EX_H
+
+#include "llvm-libc-types/pid_t.h"
+
+enum pid_type {
+  F_OWNER_TID = 0,
+  F_OWNER_PID,
+  F_OWNER_PGRP,
+};
+
+struct f_owner_ex {
+  enum pid_type type;
+  pid_t pid;
+};
+
+#endif // LLVM_LIBC_TYPES_STRUCT_F_OWNER_EX_H

libc/include/llvm-libc-types/struct_flock.h

@@ -0,0 +1,25 @@
+//===-- Definition of type struct flock64 ---------------------------------===//
+//
+// 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_FLOCK_H
+#define LLVM_LIBC_TYPES_STRUCT_FLOCK_H
+
+#include "llvm-libc-types/off_t.h"
+#include "llvm-libc-types/pid_t.h"
+
+#include <stdint.h>
+
+struct flock {
+  int16_t l_type;
+  int16_t l_whence;
+  off_t l_start;
+  off_t l_len;
+  pid_t l_pid;
+};
+
+#endif // LLVM_LIBC_TYPES_STRUCT_FLOCK_H

libc/include/llvm-libc-types/struct_flock64.h

@@ -0,0 +1,25 @@
+//===-- Definition of type struct flock64 ---------------------------------===//
+//
+// 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_FLOCK64_H
+#define LLVM_LIBC_TYPES_STRUCT_FLOCK64_H
+
+#include "llvm-libc-types/off64_t.h"
+#include "llvm-libc-types/pid_t.h"
+
+#include <stdint.h>
+
+struct flock64 {
+  int16_t l_type;
+  int16_t l_whence;
+  off64_t l_start;
+  off64_t l_len;
+  pid_t l_pid;
+};
+
+#endif // LLVM_LIBC_TYPES_STRUCT_FLOCK64_H

libc/spec/posix.td

@@ -230,6 +230,11 @@ def POSIX : StandardSpec<"POSIX"> {
           RetValSpec<IntType>,
           [ArgSpec<ConstCharPtr>, ArgSpec<ModeTType>]
       >,
+      FunctionSpec<
+          "fcntl",
+          RetValSpec<IntType>,
+          [ArgSpec<IntType>, ArgSpec<IntType>, ArgSpec<VarArgType>]
+      >,
       FunctionSpec<
           "open",
           RetValSpec<IntType>,

libc/src/fcntl/CMakeLists.txt

@@ -9,6 +9,13 @@ add_entrypoint_object(
     .${LIBC_TARGET_OS}.creat
 )
 
+add_entrypoint_object(
+  fcntl
+  ALIAS
+  DEPENDS
+    .${LIBC_TARGET_OS}.fcntl
+)
+
 add_entrypoint_object(
   open
   ALIAS

libc/src/fcntl/fcntl.h

@@ -0,0 +1,18 @@
+//===-- Implementation header of fcntl --------------------------*- 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_FCNTL_FCNTL_H
+#define LLVM_LIBC_SRC_FCNTL_FCNTL_H
+
+namespace LIBC_NAMESPACE {
+
+int fcntl(int fd, int cmd, ...);
+
+} // namespace LIBC_NAMESPACE
+
+#endif // LLVM_LIBC_SRC_FCNTL_FCNTL_H

libc/src/fcntl/linux/CMakeLists.txt

@@ -10,6 +10,22 @@ add_entrypoint_object(
     libc.src.errno.errno
 )
 
+add_entrypoint_object(
+  fcntl
+  SRCS
+    fcntl.cpp
+  HDRS
+    ../fcntl.h
+  DEPENDS
+    libc.include.fcntl
+    libc.hdr.types.struct_flock
+    libc.hdr.types.struct_flock64
+    libc.hdr.types.struct_f_owner_ex
+    libc.hdr.fcntl_macros
+    libc.src.__support.OSUtil.osutil
+    libc.src.errno.errno
+)
+
 add_entrypoint_object(
   open
   SRCS