Commit aaba36ff763a7f016bba1afc4eff758302538362 | zig

author	Josh Megnauth <jo.sh@tutanota.com> 2026-03-13 19:37:06-04:00
committer	Andrew Kelley <andrew@ziglang.org> 2026-03-14 22:04:43+01:00
log	aaba36ff763a7f016bba1afc4eff758302538362
tree	8cd7dfb6338f477fbceb3a1fce122268c9db6af3
parent	50cc3b91a5b325b645b0c5c81f3401600b15c92a

libzigc: posix_{fadvise, fallocate}, fallocate

This commit removes `posix_fadvise`, `posix_fallocate`, and `fallocate`
from the bundled musl by forwarding to Zig's wrappers. `musl`'s
implemenation does not use `__syscall_cp`, so I assume trivially
replacing these functions is okay.

For `posix_fadvise`, `musl` notes that the arguments are reordered
for ARM and other architectures. Zig's wrapper already handles this
case.

Contributes toward: #30978

6 files changed, 29 insertions(+), 36 deletions(-)

lib
- c.zig
- c
  - fcntl.zig
- libc
  - musl
    src
    fcntl
    posix_fadvise.c
    posix_fallocate.c
    linux
    fallocate.c
src
- libs
  - musl.zig

lib/c.zig+1

...	...	@@ -63,6 +63,7 @@ pub fn errno(syscall_return_value: usize) c_int {
63	63
64	64	comptime {
65	65	_ = @import("c/ctype.zig");
	66	_ = @import("c/fcntl.zig");
66	67	_ = @import("c/inttypes.zig");
67	68	if (!builtin.target.isMinGW()) {
68	69	_ = @import("c/malloc.zig");

lib/c/fcntl.zig created+28

...	...	@@ -0,0 +1,28 @@
	1	const builtin = @import("builtin");
	2
	3	const std = @import("std");
	4	const linux = std.os.linux;
	5	const off_t = linux.off_t;
	6
	7	const symbol = @import("../c.zig").symbol;
	8	const errno = @import("../c.zig").errno;
	9
	10	comptime {
	11	if (builtin.target.isMuslLibC()) {
	12	symbol(&fallocateLinux, "fallocate");
	13	symbol(&posix_fadviseLinux, "posix_fadvise");
	14	symbol(&posix_fallocateLinux, "posix_fallocate");
	15	}
	16	}
	17
	18	fn fallocateLinux(fd: c_int, mode: c_int, offset: off_t, len: off_t) callconv(.c) c_int {
	19	return errno(linux.fallocate(fd, mode, offset, len));
	20	}
	21
	22	fn posix_fadviseLinux(fd: c_int, offset: off_t, len: off_t, advice: c_int) callconv(.c) c_int {
	23	return errno(linux.fadvise(fd, offset, len, @intCast(advice)));
	24	}
	25
	26	fn posix_fallocateLinux(fd: c_int, offset: off_t, len: off_t) callconv(.c) c_int {
	27	return errno(linux.fallocate(fd, 0, offset, len));
	28	}

lib/libc/musl/src/fcntl/posix_fadvise.c deleted-16

...	...	@@ -1,16 +0,0 @@
1		#include <fcntl.h>
2		#include "syscall.h"
3
4		int posix_fadvise(int fd, off_t base, off_t len, int advice)
5		{
6		#if defined(SYSCALL_FADVISE_6_ARG)
7		/* Some archs, at least arm and powerpc, have the syscall
8		* arguments reordered to avoid needing 7 argument registers
9		* due to 64-bit argument alignment. */
10		return -__syscall(SYS_fadvise, fd, advice,
11		__SYSCALL_LL_E(base), __SYSCALL_LL_E(len));
12		#else
13		return -__syscall(SYS_fadvise, fd, __SYSCALL_LL_O(base),
14		__SYSCALL_LL_E(len), advice);
15		#endif
16		}

lib/libc/musl/src/fcntl/posix_fallocate.c deleted-8

...	...	@@ -1,8 +0,0 @@
1		#include <fcntl.h>
2		#include "syscall.h"
3
4		int posix_fallocate(int fd, off_t base, off_t len)
5		{
6		return -__syscall(SYS_fallocate, fd, 0, __SYSCALL_LL_E(base),
7		__SYSCALL_LL_E(len));
8		}

lib/libc/musl/src/linux/fallocate.c deleted-9

...	...	@@ -1,9 +0,0 @@
1		#define _GNU_SOURCE
2		#include <fcntl.h>
3		#include "syscall.h"
4
5		int fallocate(int fd, int mode, off_t base, off_t len)
6		{
7		return syscall(SYS_fallocate, fd, mode, __SYSCALL_LL_E(base),
8		__SYSCALL_LL_E(len));
9		}

src/libs/musl.zig-3

...	...	@@ -589,8 +589,6 @@ const src_files = [_][]const u8{
589	589	"musl/src/fcntl/fcntl.c",
590	590	"musl/src/fcntl/openat.c",
591	591	"musl/src/fcntl/open.c",
592		"musl/src/fcntl/posix_fadvise.c",
593		"musl/src/fcntl/posix_fallocate.c",
594	592	"musl/src/fenv/aarch64/fenv.s",
595	593	"musl/src/fenv/arm/fenv.c",
596	594	"musl/src/fenv/arm/fenv-hf.S",
...	...	@@ -708,7 +706,6 @@ const src_files = [_][]const u8{
708	706	"musl/src/linux/copy_file_range.c",
709	707	"musl/src/linux/epoll.c",
710	708	"musl/src/linux/eventfd.c",
711		"musl/src/linux/fallocate.c",
712	709	"musl/src/linux/fanotify.c",
713	710	"musl/src/linux/getdents.c",
714	711	"musl/src/linux/getrandom.c",