[libc] Add chown and getgid implementations (#166434)

Implements chown and getgid per the POSIX specification and adds
corresponding unit tests. getgid is added as it is required by the chown
unit tests. This PR will address #165785

Co-authored-by: shubh@DOE <[email protected]>

Author: shubhe25p

libc/config/linux/x86_64/entrypoints.txt

@@ -326,6 +326,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     # unistd.h entrypoints
     libc.src.unistd.access
     libc.src.unistd.chdir
+    libc.src.unistd.chown
     libc.src.unistd.close
     libc.src.unistd.dup
     libc.src.unistd.dup2
@@ -344,6 +345,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.unistd.getppid
     libc.src.unistd.getsid
     libc.src.unistd.gettid
+    libc.src.unistd.getgid
     libc.src.unistd.getuid
     libc.src.unistd.isatty
     libc.src.unistd.link

libc/hdr/types/CMakeLists.txt

@@ -479,3 +479,11 @@ add_proxy_header_library(
     libc.include.llvm-libc-types.struct_rlimit
     libc.include.sys_resource
 )
+
+add_proxy_header_library(
+  gid_t
+  HDRS
+    gid_t.h
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-types.gid_t
+)

libc/hdr/types/gid_t.h

@@ -0,0 +1,22 @@
+//===-- Proxy for gid_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_GID_T_H
+#define LLVM_LIBC_HDR_TYPES_GID_T_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-types/gid_t.h"
+
+#else // Overlay mode
+
+#include <sys/types.h>
+
+#endif // LLVM_LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_TYPES_GID_T_H

libc/include/unistd.yaml

@@ -3,6 +3,7 @@ header_template: unistd.h.def
 macros: []
 types:
   - type_name: uid_t
+  - type_name: gid_t
   - type_name: ssize_t
   - type_name: size_t
   - type_name: pid_t
@@ -54,6 +55,14 @@ functions:
     return_type: int
     arguments:
       - type: const char *
+  - name: chown
+    standards:
+      - POSIX
+    return_type: int
+    arguments:
+      - type: const char *
+      - type: uid_t
+      - type: gid_t
   - name: close
     standards:
       - POSIX
@@ -195,6 +204,12 @@ functions:
     return_type: uid_t
     arguments:
       - type: void
+  - name: getgid
+    standards:
+      - POSIX
+    return_type: gid_t
+    arguments:
+      - type: void
   - name: isatty
     standards:
       - POSIX

libc/src/unistd/CMakeLists.txt

@@ -27,6 +27,13 @@ add_entrypoint_object(
     .${LIBC_TARGET_OS}.chdir
 )
 
+add_entrypoint_object(
+  chown
+  ALIAS
+  DEPENDS
+    .${LIBC_TARGET_OS}.chown
+)
+
 add_entrypoint_object(
   close
   ALIAS
@@ -160,6 +167,13 @@ add_entrypoint_object(
     .${LIBC_TARGET_OS}.getuid
 )
 
+add_entrypoint_object(
+  getgid
+  ALIAS
+  DEPENDS
+    .${LIBC_TARGET_OS}.getgid
+)
+
 add_entrypoint_object(
   isatty
   ALIAS

libc/src/unistd/chown.h

@@ -0,0 +1,22 @@
+//===-- Implementation header for chown -------------------------*- 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_CHOWN_H
+#define LLVM_LIBC_SRC_UNISTD_CHOWN_H
+
+#include "hdr/types/gid_t.h"
+#include "hdr/types/uid_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int chown(const char *path, uid_t owner, gid_t group);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_UNISTD_CHOWN_H

libc/src/unistd/getgid.h

@@ -0,0 +1,22 @@
+//===-- Implementation header for getgid ------------------------*- 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_GETGID_H
+#define LLVM_LIBC_SRC_UNISTD_GETGID_H
+
+#include "hdr/types/gid_t.h"
+#include "hdr/unistd_macros.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+gid_t getgid();
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_UNISTD_GETGID_H

libc/src/unistd/linux/CMakeLists.txt

@@ -25,6 +25,20 @@ add_entrypoint_object(
     libc.src.errno.errno
 )
 
+add_entrypoint_object(
+  chown
+  SRCS
+    chown.cpp
+  HDRS
+    ../chown.h
+  DEPENDS
+    libc.hdr.types.uid_t
+    libc.hdr.types.gid_t
+    libc.include.sys_syscall
+    libc.src.__support.OSUtil.osutil
+    libc.src.errno.errno
+)
+
 add_entrypoint_object(
   close
   SRCS
@@ -276,6 +290,20 @@ add_entrypoint_object(
     libc.src.errno.errno
 )
 
+add_entrypoint_object(
+  getgid
+  SRCS
+    getgid.cpp
+  HDRS
+    ../getgid.h
+  DEPENDS
+    libc.hdr.types.gid_t
+    libc.hdr.fcntl_macros
+    libc.include.unistd
+    libc.include.sys_syscall
+    libc.src.__support.OSUtil.osutil
+)
+
 add_entrypoint_object(
   getuid
   SRCS

libc/src/unistd/linux/chown.cpp

@@ -0,0 +1,29 @@
+//===-- Linux implementation of chown -------------------------------------===//
+//
+// 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/chown.h"
+
+#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
+#include "src/__support/common.h"
+
+#include "src/__support/libc_errno.h"
+#include "src/__support/macros/config.h"
+#include <sys/syscall.h> // For syscall numbers.
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, chown, (const char *path, uid_t owner, gid_t group)) {
+  int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_chown, path, owner, group);
+  if (ret < 0) {
+    libc_errno = -ret;
+    return -1;
+  }
+  return 0;
+}
+
+} // namespace LIBC_NAMESPACE_DECL

libc/src/unistd/linux/getgid.cpp

@@ -0,0 +1,23 @@
+//===-- Linux implementation of getgid ------------------------------------===//
+//
+// 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/getgid.h"
+
+#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+#include <sys/syscall.h> // For syscall numbers.
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(gid_t, getgid, ()) {
+  return LIBC_NAMESPACE::syscall_impl<gid_t>(SYS_getgid);
+}
+
+} // namespace LIBC_NAMESPACE_DECL