[libc-commits] [libc] [libc] Add getpid syscall wrapper for Linux (PR #220595)

[Tapiwa Gonga via libc-commits]

https://github.com/tapiwagonga updated https://github.com/llvm/llvm-project/pull/220595

>From 6d7c971bd3f90f5fbdbf0c7dc841f27cd4c8eaf5 Mon Sep 17 00:00:00 2001
From: Tapiwa Gonga <tapiwagonga at google.com>
Date: Wed, 2 Sep 2026 11:05:31 +0000
Subject: [PATCH] Add getpid syscall wrapper

---
 .../linux/syscall_wrappers/CMakeLists.txt     | 12 +++++++
 .../OSUtil/linux/syscall_wrappers/getpid.h    | 31 +++++++++++++++++++
 libc/src/unistd/linux/CMakeLists.txt          |  5 +--
 libc/src/unistd/linux/getpid.cpp              |  8 ++---
 4 files changed, 46 insertions(+), 10 deletions(-)
 create mode 100644 libc/src/__support/OSUtil/linux/syscall_wrappers/getpid.h

diff --git a/libc/src/__support/OSUtil/linux/syscall_wrappers/CMakeLists.txt b/libc/src/__support/OSUtil/linux/syscall_wrappers/CMakeLists.txt
index 6440e985a94c4..77ebf22b1048b 100644
--- a/libc/src/__support/OSUtil/linux/syscall_wrappers/CMakeLists.txt
+++ b/libc/src/__support/OSUtil/linux/syscall_wrappers/CMakeLists.txt
@@ -26,6 +26,18 @@ add_header_library(
     libc.include.sys_syscall
 )
 
+add_header_library(
+  getpid
+  HDRS
+    getpid.h
+  DEPENDS
+    libc.src.__support.OSUtil.osutil
+    libc.src.__support.common
+    libc.src.__support.macros.config
+    libc.hdr.types.pid_t
+    libc.include.sys_syscall
+)
+
 add_header_library(
   sched_getaffinity
   HDRS
diff --git a/libc/src/__support/OSUtil/linux/syscall_wrappers/getpid.h b/libc/src/__support/OSUtil/linux/syscall_wrappers/getpid.h
new file mode 100644
index 0000000000000..7644b67449fdb
--- /dev/null
+++ b/libc/src/__support/OSUtil/linux/syscall_wrappers/getpid.h
@@ -0,0 +1,31 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+/// Syscall wrapper for getpid.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_SYSCALL_WRAPPERS_GETPID_H
+#define LLVM_LIBC_SRC___SUPPORT_OSUTIL_SYSCALL_WRAPPERS_GETPID_H
+
+#include "hdr/types/pid_t.h"
+#include "src/__support/OSUtil/linux/syscall.h" // syscall_impl
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+#include <sys/syscall.h> // For syscall numbers
+
+namespace LIBC_NAMESPACE_DECL {
+namespace linux_syscalls {
+
+LIBC_INLINE pid_t getpid() { return syscall_impl<pid_t>(SYS_getpid); }
+
+} // namespace linux_syscalls
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_SYSCALL_WRAPPERS_GETPID_H
diff --git a/libc/src/unistd/linux/CMakeLists.txt b/libc/src/unistd/linux/CMakeLists.txt
index 80c4b6e8fd1c8..37125f3c4c651 100644
--- a/libc/src/unistd/linux/CMakeLists.txt
+++ b/libc/src/unistd/linux/CMakeLists.txt
@@ -286,10 +286,7 @@ add_entrypoint_object(
     ../getpid.h
   DEPENDS
     libc.hdr.types.pid_t
-    libc.hdr.fcntl_macros
-    libc.include.unistd
-    libc.include.sys_syscall
-    libc.src.__support.OSUtil.osutil
+    libc.src.__support.OSUtil.linux.syscall_wrappers.getpid
 )
 
 add_entrypoint_object(
diff --git a/libc/src/unistd/linux/getpid.cpp b/libc/src/unistd/linux/getpid.cpp
index b24c86a15990f..c1749baa8081f 100644
--- a/libc/src/unistd/linux/getpid.cpp
+++ b/libc/src/unistd/linux/getpid.cpp
@@ -8,16 +8,12 @@
 
 #include "src/unistd/getpid.h"
 
-#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
+#include "src/__support/OSUtil/linux/syscall_wrappers/getpid.h"
 #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(pid_t, getpid, ()) {
-  return LIBC_NAMESPACE::syscall_impl<pid_t>(SYS_getpid);
-}
+LLVM_LIBC_FUNCTION(pid_t, getpid, ()) { return linux_syscalls::getpid(); }
 
 } // namespace LIBC_NAMESPACE_DECL