From 21914c7c01d8d1071034153451414719906167b8 Mon Sep 17 00:00:00 2001
From: David Senoner <seda18@rolmail.net>
Date: Sat, 18 Apr 2026 07:30:43 +0200
Subject: [PATCH] ziglibc: migrate tee linux syscall (#31911)

Add the Linux syscall wrapper for `tee`.

Migrate the `tee` syscall from musl libc to zig libc.

langref: note `ssize_t` and `isize`  are ABI compatible

Reviewed-on: https://codeberg.org/ziglang/zig/pulls/31911
Reviewed-by: Andrew Kelley <andrew@ziglang.org>
Co-authored-by: David Senoner <seda18@rolmail.net>
Co-committed-by: David Senoner <seda18@rolmail.net>
---
 doc/langref.html.in           |  2 +-
 lib/c/fcntl.zig               |  5 +++++
 lib/libc/musl/src/linux/tee.c |  8 --------
 lib/std/os/linux.zig          | 10 ++++++++++
 src/libs/musl.zig             |  1 -
 5 files changed, 16 insertions(+), 10 deletions(-)
 delete mode 100644 lib/libc/musl/src/linux/tee.c

diff --git a/doc/langref.html.in b/doc/langref.html.in
index 2020d248c1..53ccac4803 100644
--- a/doc/langref.html.in
+++ b/doc/langref.html.in
@@ -525,7 +525,7 @@
         </tr>
         <tr>
             <th scope="row">{#syntax#}isize{#endsyntax#}</th>
-          <td><code class="c">intptr_t</code></td>
+          <td><code class="c">intptr_t</code>, <code class="c">ssize_t</code></td>
           <td>signed pointer sized integer</td>
         </tr>
         <tr>
diff --git a/lib/c/fcntl.zig b/lib/c/fcntl.zig
index 29788fa922..e9a0630552 100644
--- a/lib/c/fcntl.zig
+++ b/lib/c/fcntl.zig
@@ -12,6 +12,7 @@ comptime {
         symbol(&fallocateLinux, "fallocate");
         symbol(&posix_fadviseLinux, "posix_fadvise");
         symbol(&posix_fallocateLinux, "posix_fallocate");
+        symbol(&teeLinux, "tee");
     }
 }
 
@@ -26,3 +27,7 @@ fn posix_fadviseLinux(fd: c_int, offset: off_t, len: off_t, advice: c_int) callc
 fn posix_fallocateLinux(fd: c_int, offset: off_t, len: off_t) callconv(.c) c_int {
     return errno(linux.fallocate(fd, 0, offset, len));
 }
+
+fn teeLinux(src: c_int, dest: c_int, len: usize, flags: c_uint) callconv(.c) isize {
+    return errno(linux.tee(src, dest, len, flags));
+}
diff --git a/lib/libc/musl/src/linux/tee.c b/lib/libc/musl/src/linux/tee.c
deleted file mode 100644
index a24748cfb0..0000000000
--- a/lib/libc/musl/src/linux/tee.c
+++ /dev/null
@@ -1,8 +0,0 @@
-#define _GNU_SOURCE
-#include <fcntl.h>
-#include "syscall.h"
-
-ssize_t tee(int src, int dest, size_t len, unsigned flags)
-{
-	return syscall(SYS_tee, src, dest, len, flags);
-}
diff --git a/lib/std/os/linux.zig b/lib/std/os/linux.zig
index ffe9ef15f3..8a3d1a3b76 100644
--- a/lib/std/os/linux.zig
+++ b/lib/std/os/linux.zig
@@ -2981,6 +2981,16 @@ pub fn map_shadow_stack(addr: usize, size: usize, flags: u32) usize {
     return syscall3(.map_shadow_stack, addr, size, flags);
 }
 
+pub fn tee(src: fd_t, dest: fd_t, len: usize, flags: u32) usize {
+    return syscall4(
+        .tee,
+        @as(u32, @bitCast(src)),
+        @as(u32, @bitCast(dest)),
+        len,
+        flags,
+    );
+}
+
 pub const Sysinfo = switch (native_abi) {
     .gnux32, .muslx32 => extern struct {
         /// Seconds since boot
diff --git a/src/libs/musl.zig b/src/libs/musl.zig
index f53b406568..beb1c2ceb8 100644
--- a/src/libs/musl.zig
+++ b/src/libs/musl.zig
@@ -745,7 +745,6 @@ const src_files = [_][]const u8{
     "musl/src/linux/sync_file_range.c",
     "musl/src/linux/syncfs.c",
     "musl/src/linux/sysinfo.c",
-    "musl/src/linux/tee.c",
     "musl/src/linux/timerfd.c",
     "musl/src/linux/unshare.c",
     "musl/src/linux/utimes.c",