[libc] Add implementations of POSIX getpid, getppid, getuid, geteuid functions.

libc/config/linux/api.td

def DirentAPI : PublicAPI<"dirent.h"> {
   let Types = [
     "ino_t",
     "DIR",
     "struct dirent",
   ];
 }
 
 def UniStdAPI : PublicAPI<"unistd.h"> {
-  let Types = ["off_t", "size_t", "ssize_t"];
+  let Types = ["off_t", "pid_t", "size_t", "ssize_t", "uid_t"];
 }
 
 def SysResourceAPI : PublicAPI<"sys/resource.h"> {
   let Types = ["rlim_t", "struct rlimit"];
 }
 
 def SysStatAPI : PublicAPI<"sys/stat.h"> {
   let Types = ["mode_t", "dev_t", "ino_t", "nlink_t", "uid_t", "gid_t", "off_t",

libc/config/linux/x86_64/entrypoints.txt

set(TARGET_LIBC_ENTRYPOINTS
     libc.src.unistd.chdir
     libc.src.unistd.close
     libc.src.unistd.dup
     libc.src.unistd.dup2
     libc.src.unistd.dup3
     libc.src.unistd.fchdir
     libc.src.unistd.fsync
     libc.src.unistd.ftruncate
+    libc.src.unistd.geteuid
+    libc.src.unistd.getpid
+    libc.src.unistd.getppid
+    libc.src.unistd.getuid
     libc.src.unistd.link
     libc.src.unistd.linkat
     libc.src.unistd.lseek
     libc.src.unistd.pread
     libc.src.unistd.pwrite
     libc.src.unistd.read
     libc.src.unistd.readlink
     libc.src.unistd.readlinkat

libc/include/CMakeLists.txt

 add_gen_header(
   unistd
   DEF_FILE unistd.h.def
   GEN_HDR unistd.h
   DEPENDS
     .llvm_libc_common_h
     .llvm-libc-macros.file_seek_macros
     .llvm-libc-macros.unistd_macros
+    .llvm-libc-types.pid_t
     .llvm-libc-types.size_t
     .llvm-libc-types.ssize_t
+    .llvm-libc-types.uid_t
 )
 
 add_gen_header(
   pthread
   DEF_FILE pthread.h.def
   GEN_HDR pthread.h
   DEPENDS
     .llvm_libc_common_h

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

 add_header(uid_t HDR uid_t.h)
 add_header(imaxdiv_t HDR imaxdiv_t.h)
 add_header(ino_t HDR ino_t.h)
 add_header(mode_t HDR mode_t.h)
 add_header(mtx_t HDR mtx_t.h DEPENDS .__futex_word .__mutex_type)
 add_header(nlink_t HDR nlink_t.h)
 add_header(off_t HDR off_t.h)
 add_header(once_flag HDR once_flag.h DEPENDS .__futex_word)
+add_header(pid_t HDR pid_t.h)
 add_header(pthread_attr_t HDR pthread_attr_t.h DEPENDS .size_t)
 add_header(pthread_key_t HDR pthread_key_t.h)
 add_header(pthread_mutex_t HDR pthread_mutex_t.h DEPENDS .__futex_word .__mutex_type)
 add_header(pthread_t HDR pthread_t.h DEPENDS .__thread_type)
 add_header(pthread_mutexattr_t HDR pthread_mutexattr_t.h)
 add_header(rlim_t HDR rlim_t.h)
 add_header(struct_rlimit HDR struct_rlimit.h DEPENDS .rlim_t)
 add_header(ssize_t HDR ssize_t.h)

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

+//===-- Definition of pid_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_PID_t_H__
+#define __LLVM_LIBC_TYPES_PID_t_H__
+
+typedef __INT32_TYPE__ pid_t;
+
+#endif // __LLVM_LIBC_TYPES_PID_t_H__

libc/spec/posix.td

 def InoT : NamedType<"ino_t">;
 def UidT : NamedType<"uid_t">;
 def GidT : NamedType<"gid_t">;
 def DevT : NamedType<"dev_t">;
 def BlkSizeT : NamedType<"blksize_t">;
 def BlkCntT : NamedType<"blkcnt_t">;
 def NLinkT : NamedType<"nlink_t">;
 def TimeSpec : NamedType<"struct timespec">;
+def PidT : NamedType<"pid_t">;
 
 def StatType : NamedType<"struct stat">;
 def StatTypePtr : PtrType<StatType>;
 def RestrictedStatTypePtr : RestrictedPtrType<StatType>;
 
 def DIR : NamedType<"DIR">;
 def DIRPtr : PtrType<DIR>;
 def DIRRestrictedPtr : RestrictedPtrType<DIR>;
def POSIX : StandardSpec<"POSIX"> {
 
   HeaderSpec UniStd = HeaderSpec<
     "unistd.h",
     [], // Macros
     [
       OffTType,
       SSizeTType,
       SizeTType,
+      PidT,
+      UidT,
     ],
     [], // Enumerations
     [
         FunctionSpec<
           "access",
           RetValSpec<IntType>,
           [ArgSpec<ConstCharPtr>, ArgSpec<IntType>]
         >,
[
           [ArgSpec<IntType>]
         >,
         FunctionSpec<
           "ftruncate",
           RetValSpec<IntType>,
           [ArgSpec<ConstCharPtr>, ArgSpec<OffTType>]
         >,
         FunctionSpec<
+          "geteuid",
+          RetValSpec<UidT>,
+          [ArgSpec<VoidType>]
+        >,
+        FunctionSpec<
+          "getpid",
+          RetValSpec<PidT>,
+          [ArgSpec<VoidType>]
+        >,
+        FunctionSpec<
+          "getppid",
+          RetValSpec<PidT>,
+          [ArgSpec<VoidType>]
+        >,
+        FunctionSpec<
+          "getuid",
+          RetValSpec<UidT>,
+          [ArgSpec<VoidType>]
+        >,
+        FunctionSpec<
+          "link",
+          RetValSpec<IntType>,
+          [ArgSpec<ConstCharPtr>, ArgSpec<ConstCharPtr>]
+        >,
+        FunctionSpec<
+          "linkat",
+          RetValSpec<IntType>,
+          [ArgSpec<IntType>, ArgSpec<ConstCharPtr>, ArgSpec<IntType>, ArgSpec<ConstCharPtr>, ArgSpec<IntType>]
+        >,
+        FunctionSpec<
+          "lseek",
+          RetValSpec<OffTType>,
+          [ArgSpec<IntType>, ArgSpec<OffTType>, ArgSpec<IntType>]
+        >,
+        FunctionSpec<
+          "pread",
+          RetValSpec<SSizeTType>,
+          [ArgSpec<IntType>, ArgSpec<VoidPtr>, ArgSpec<SizeTType>, ArgSpec<OffTType>]
+        >,
+        FunctionSpec<
+          "pwrite",
+          RetValSpec<SSizeTType>,
+          [ArgSpec<IntType>, ArgSpec<ConstVoidPtr>, ArgSpec<SizeTType>, ArgSpec<OffTType>]
+        >,
+        FunctionSpec<
+          "read",
+          RetValSpec<SSizeTType>,
+          [ArgSpec<IntType>, ArgSpec<VoidPtr>, ArgSpec<SizeTType>]
+        >,
+        FunctionSpec<
+          "readlink",
+          RetValSpec<SSizeTType>,
+          [ArgSpec<ConstCharRestrictedPtr>, ArgSpec<CharRestrictedPtr>, ArgSpec<SizeTType>]
+        >,
+        FunctionSpec<
+          "readlinkat",
+          RetValSpec<SSizeTType>,
+          [ArgSpec<ConstCharRestrictedPtr>, ArgSpec<CharRestrictedPtr>, ArgSpec<SizeTType>]
+        >,
+        FunctionSpec<
+          "rmdir",
+          RetValSpec<IntType>,
+          [ArgSpec<ConstCharPtr>]
+        >,
+        FunctionSpec<
+          "getpid",
+          RetValSpec<IntType>,
+          [ArgSpec<VoidType>]
+        >,
+        FunctionSpec<
+          "getppid",
+          RetValSpec<IntType>,
+          [ArgSpec<VoidType>]
+        >,
+        FunctionSpec<
           "link",
           RetValSpec<IntType>,
           [ArgSpec<ConstCharPtr>, ArgSpec<ConstCharPtr>]
         >,
         FunctionSpec<
           "linkat",
           RetValSpec<IntType>,
           [ArgSpec<IntType>, ArgSpec<ConstCharPtr>, ArgSpec<IntType>, ArgSpec<ConstCharPtr>, ArgSpec<IntType>]

libc/src/unistd/CMakeLists.txt

 add_entrypoint_object(
   ftruncate
   ALIAS
   DEPENDS
     .${LIBC_TARGET_OS}.ftruncate
 )
 
 add_entrypoint_object(
+  getpid
+  ALIAS
+  DEPENDS
+    .${LIBC_TARGET_OS}.getpid
+)
+
+add_entrypoint_object(
+  getppid
+  ALIAS
+  DEPENDS
+    .${LIBC_TARGET_OS}.getppid
+)
+
+add_entrypoint_object(
+  geteuid
+  ALIAS
+  DEPENDS
+    .${LIBC_TARGET_OS}.geteuid
+)
+
+add_entrypoint_object(
+  getuid
+  ALIAS
+  DEPENDS
+    .${LIBC_TARGET_OS}.getuid
+)
+
+add_entrypoint_object(
   link
   ALIAS
   DEPENDS
     .${LIBC_TARGET_OS}.link
 )
 
 add_entrypoint_object(
   linkat

libc/src/unistd/geteuid.h

+//===-- Implementation header for geteuid -----------------------*- 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_UNISTD_GETEUID_H
+#define LLVM_LIBC_SRC_UNISTD_GETEUID_H
+
+#include <unistd.h>
+
+namespace __llvm_libc {
+
+uid_t geteuid();
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_UNISTD_GETEUID_H

libc/src/unistd/getpid.h

+//===-- Implementation header for getpid ------------------------*- 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_UNISTD_GETPID_H
+#define LLVM_LIBC_SRC_UNISTD_GETPID_H
+
+#include <unistd.h>
+
+namespace __llvm_libc {
+
+pid_t getpid();
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_UNISTD_GETPID_H

libc/src/unistd/getppid.h

+//===-- Implementation header for getppid -----------------------*- 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_UNISTD_GETPPID_H
+#define LLVM_LIBC_SRC_UNISTD_GETPPID_H
+
+#include <unistd.h>
+
+namespace __llvm_libc {
+
+pid_t getppid();
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_UNISTD_GETPPID_H

libc/src/unistd/getuid.h

+//===-- Implementation header for getuid ------------------------*- 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_UNISTD_GETUID_H
+#define LLVM_LIBC_SRC_UNISTD_GETUID_H
+
+#include <unistd.h>
+
+namespace __llvm_libc {
+
+uid_t getuid();
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_UNISTD_GETUID_H

libc/src/unistd/linux/CMakeLists.txt

add_entrypoint_object(
   DEPENDS
     libc.include.unistd
     libc.include.sys_syscall
     libc.src.__support.OSUtil.osutil
     libc.src.errno.errno
 )
 
 add_entrypoint_object(
+  geteuid
+  SRCS
+    geteuid.cpp
+  HDRS
+    ../geteuid.h
+  DEPENDS
+    libc.include.unistd
+    libc.include.sys_syscall
+    libc.src.__support.OSUtil.osutil
+)
+
+add_entrypoint_object(
+  getpid
+  SRCS
+    getpid.cpp
+  HDRS
+    ../getpid.h
+  DEPENDS
+    libc.include.unistd
+    libc.include.sys_syscall
+    libc.src.__support.OSUtil.osutil
+)
+
+add_entrypoint_object(
+  getppid
+  SRCS
+    getppid.cpp
+  HDRS
+    ../getppid.h
+  DEPENDS
+    libc.include.unistd
+    libc.include.sys_syscall
+    libc.src.__support.OSUtil.osutil
+)
+
+add_entrypoint_object(
+  getuid
+  SRCS
+    getuid.cpp
+  HDRS
+    ../getuid.h
+  DEPENDS
+    libc.include.unistd
+    libc.include.sys_syscall
+    libc.src.__support.OSUtil.osutil
+)
+
+add_entrypoint_object(
   link
   SRCS
     link.cpp
   HDRS
     ../link.h
   DEPENDS
     libc.include.fcntl
     libc.include.unistd

libc/src/unistd/linux/geteuid.cpp

+//===-- Linux implementation of geteuid -----------------------------------===//
+//
+// 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/unistd/geteuid.h"
+
+#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
+#include "src/__support/common.h"
+
+#include <sys/syscall.h> // For syscall numbers.
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(uid_t, geteuid, ()) {
+  return __llvm_libc::syscall(SYS_geteuid);
+}
+
+} // namespace __llvm_libc

libc/src/unistd/linux/getpid.cpp

+//===-- Linux implementation of getpid ------------------------------------===//
+//
+// 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/unistd/getpid.h"
+
+#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
+#include "src/__support/common.h"
+
+#include <sys/syscall.h> // For syscall numbers.
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(pid_t, getpid, ()) {
+  return __llvm_libc::syscall(SYS_getpid);
+}
+
+} // namespace __llvm_libc

libc/src/unistd/linux/getppid.cpp

+//===-- Linux implementation of getppid -----------------------------------===//
+//
+// 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/unistd/getppid.h"
+
+#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
+#include "src/__support/common.h"
+
+#include <sys/syscall.h> // For syscall numbers.
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(pid_t, getppid, ()) {
+  return __llvm_libc::syscall(SYS_getppid);
+}
+
+} // namespace __llvm_libc

libc/src/unistd/linux/getuid.cpp

+//===-- Linux implementation of getuid ------------------------------------===//
+//
+// 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/unistd/getuid.h"
+
+#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
+#include "src/__support/common.h"
+
+#include <sys/syscall.h> // For syscall numbers.
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(uid_t, getuid, ()) {
+  return __llvm_libc::syscall(SYS_getuid);
+}
+
+} // namespace __llvm_libc

libc/test/src/unistd/CMakeLists.txt

add_libc_unittest(
   DEPENDS
     libc.include.errno
     libc.include.unistd
     libc.src.fcntl.open
     libc.src.fcntl.openat
     libc.src.unistd.close
     libc.src.unistd.unlinkat
 )
+
+add_libc_unittest(
+  getpid_test
+  SUITE
+    libc_unistd_unittests
+  SRCS
+    getpid_test.cpp
+  DEPENDS
+    libc.src.unistd.getpid
+)
+
+add_libc_unittest(
+  getppid_test
+  SUITE
+    libc_unistd_unittests
+  SRCS
+    getppid_test.cpp
+  DEPENDS
+    libc.src.unistd.getppid
+)
+
+add_libc_unittest(
+  getuid_test
+  SUITE
+    libc_unistd_unittests
+  SRCS
+    getuid_test.cpp
+  DEPENDS
+    libc.src.unistd.getuid
+)
+
+add_libc_unittest(
+  geteuid_test
+  SUITE
+    libc_unistd_unittests
+  SRCS
+    geteuid_test.cpp
+  DEPENDS
+    libc.src.unistd.geteuid
+)

libc/test/src/unistd/geteuid_test.cpp

+//===-- Unittests for geteuid ---------------------------------------------===//
+//
+// 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/unistd/geteuid.h"
+#include "utils/UnitTest/Test.h"
+
+TEST(LlvmLibcGetEuidTest, SmokeTest) {
+  // geteuid always succeeds. So, we just call it as a smoke test.
+  __llvm_libc::geteuid();
+}

libc/test/src/unistd/getpid_test.cpp

+//===-- Unittests for getpid ----------------------------------------------===//
+//
+// 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/unistd/getpid.h"
+#include "utils/UnitTest/Test.h"
+
+TEST(LlvmLibcGetPidTest, SmokeTest) {
+  // getpid always succeeds. So, we just call it as a smoke test.
+  __llvm_libc::getpid();
+}

libc/test/src/unistd/getppid_test.cpp

+//===-- Unittests for getppid ---------------------------------------------===//
+//
+// 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/unistd/getppid.h"
+#include "utils/UnitTest/Test.h"
+
+TEST(LlvmLibcGetPpidTest, SmokeTest) {
+  // getppid always succeeds. So, we just call it as a smoke test.
+  __llvm_libc::getppid();
+}

libc/test/src/unistd/getuid_test.cpp

+//===-- Unittests for getuid ----------------------------------------------===//
+//
+// 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/unistd/getuid.h"
+#include "utils/UnitTest/Test.h"
+
+TEST(LlvmLibcGetUidTest, SmokeTest) {
+  // getuid always succeeds. So, we just call it as a smoke test.
+  __llvm_libc::getuid();
+}