| author |  Ivel <ivel.santos@proton.me> 2026-02-05 20:21:41+01:00 |
| committer |  Andrew Kelley <andrew@ziglang.org> 2026-02-05 20:21:41+01:00 |
| log | fa3228ae42d3bc92ad66fe91e108511583129ffd |
| tree | d29d7d2bd80dfc23387850a509a83be906a795f3 |
| parent | c77e7146f5fa8e83c06cd6612b7298df06912974 |
libc: reimplement swab in Zig (#31130)
This PR replaces the bundled musl swab() implementation with zig's one.
Contributes towards #30978.
It looks like there are not test cases for swab() in test-libc.
Reviewed-on: https://codeberg.org/ziglang/zig/pulls/31130
Reviewed-by: Andrew Kelley <andrew@ziglang.org>
Co-authored-by: Ivel <ivel.santos@proton.me>
Co-committed-by: Ivel <ivel.santos@proton.me>4 files changed, 42 insertions(+), 15 deletions(-)
lib- libc
- musl
- src
- string
- src
lib/c/unistd.zig+42
| ... | ... | @@ -43,6 +43,9 @@ comptime { |
| 43 | 43 | |
| 44 | 44 | @export(&execveLinux, .{ .name = "execve", .linkage = common.linkage, .visibility = common.visibility }); |
| 45 | 45 | } |
| 46 | if (builtin.target.isMuslLibC() or builtin.target.isWasiLibC()) { | |
| 47 | @export(&swab, .{ .name = "swab", .linkage = common.linkage, .visibility = common.visibility }); | |
| 48 | } | |
| 46 | 49 | } |
| 47 | 50 | |
| 48 | 51 | fn _exit(exit_code: c_int) callconv(.c) noreturn { |
| ... | ... | @@ -181,3 +184,42 @@ fn unlinkatLinux(fd: c_int, path: [*:0]const c_char, flags: c_int) callconv(.c) |
| 181 | 184 | fn execveLinux(path: [*:0]const c_char, argv: [*:null]const ?[*:0]c_char, envp: [*:null]const ?[*:0]c_char) callconv(.c) c_int { |
| 182 | 185 | return common.errno(linux.execve(@ptrCast(path), @ptrCast(argv), @ptrCast(envp))); |
| 183 | 186 | } |
| 187 | ||
| 188 | fn swab(noalias src_ptr: *const anyopaque, noalias dest_ptr: *anyopaque, n: isize) callconv(.c) void { | |
| 189 | var src: [*]const u8 = @ptrCast(src_ptr); | |
| 190 | var dest: [*]u8 = @ptrCast(dest_ptr); | |
| 191 | var i = n; | |
| 192 | ||
| 193 | while (i > 1) : (i -= 2) { | |
| 194 | dest[0] = src[1]; | |
| 195 | dest[1] = src[0]; | |
| 196 | dest += 2; | |
| 197 | src += 2; | |
| 198 | } | |
| 199 | } | |
| 200 | ||
| 201 | test swab { | |
| 202 | var a: [4]u8 = undefined; | |
| 203 | @memset(a[0..], '\x00'); | |
| 204 | swab("abcd", &a, 4); | |
| 205 | try std.testing.expectEqualSlices(u8, "badc", &a); | |
| 206 | ||
| 207 | // Partial copy | |
| 208 | @memset(a[0..], '\x00'); | |
| 209 | swab("abcd", &a, 2); | |
| 210 | try std.testing.expectEqualSlices(u8, "ba\x00\x00", &a); | |
| 211 | ||
| 212 | // n < 1 | |
| 213 | @memset(a[0..], '\x00'); | |
| 214 | swab("abcd", &a, 0); | |
| 215 | try std.testing.expectEqualSlices(u8, "\x00" ** 4, &a); | |
| 216 | swab("abcd", &a, -1); | |
| 217 | try std.testing.expectEqualSlices(u8, "\x00" ** 4, &a); | |
| 218 | ||
| 219 | // Odd n | |
| 220 | @memset(a[0..], '\x00'); | |
| 221 | swab("abcd", &a, 1); | |
| 222 | try std.testing.expectEqualSlices(u8, "\x00" ** 4, &a); | |
| 223 | swab("abcd", &a, 3); | |
| 224 | try std.testing.expectEqualSlices(u8, "ba\x00\x00", &a); | |
| 225 | } |
lib/libc/musl/src/string/swab.c deleted-13
| ... | ... | @@ -1,13 +0,0 @@ |
| 1 | #include <unistd.h> | |
| 2 | ||
| 3 | void swab(const void *restrict _src, void *restrict _dest, ssize_t n) | |
| 4 | { | |
| 5 | const char *src = _src; | |
| 6 | char *dest = _dest; | |
| 7 | for (; n>1; n-=2) { | |
| 8 | dest[0] = src[1]; | |
| 9 | dest[1] = src[0]; | |
| 10 | dest += 2; | |
| 11 | src += 2; | |
| 12 | } | |
| 13 | } |
src/libs/musl.zig-1
| ... | ... | @@ -1579,7 +1579,6 @@ const src_files = [_][]const u8{ |
| 1579 | 1579 | "musl/src/string/strndup.c", |
| 1580 | 1580 | "musl/src/string/strsignal.c", |
| 1581 | 1581 | "musl/src/string/strverscmp.c", |
| 1582 | "musl/src/string/swab.c", | |
| 1583 | 1582 | "musl/src/string/wcscasecmp.c", |
| 1584 | 1583 | "musl/src/string/wcscasecmp_l.c", |
| 1585 | 1584 | "musl/src/string/wcsdup.c", |
src/libs/wasi_libc.zig-1
| ... | ... | @@ -957,7 +957,6 @@ const libc_top_half_src_files = [_][]const u8{ |
| 957 | 957 | "musl/src/string/strerror_r.c", |
| 958 | 958 | "musl/src/string/strndup.c", |
| 959 | 959 | "musl/src/string/strverscmp.c", |
| 960 | "musl/src/string/swab.c", | |
| 961 | 960 | "musl/src/string/wcscasecmp.c", |
| 962 | 961 | "musl/src/string/wcscasecmp_l.c", |
| 963 | 962 | "musl/src/string/wcsdup.c", |