| author |  Alex Rønne Petersen <alex@alexrp.com> 2026-10-13 20:06:22+02:00 |
| committer | Alex Rønne Petersen <alex@alexrp.com> 2026-10-15 22:58:53+02:00 |
| log | 8b52a7c0c5a602439b13d7791902777bfe80d454 |
| tree | 8e6fc208b9f09ea29a64b1a89eb2ea6a0c99729e |
| parent | 9c011c6a40e31995839bbea226715062bc5e07eb |
std.c, libzigc: fix ffs() family signatures and implementation bugs
3 files changed, 8 insertions(+), 12 deletions(-)
lib
std
test
lib/c/strings.zig+4-4
| ... | @@ -44,19 +44,19 @@ fn rindex(str: [*:0]const c_char, value: c_int) callconv(.c) ?[*:0]c_char { | ... | @@ -44,19 +44,19 @@ fn rindex(str: [*:0]const c_char, value: c_int) callconv(.c) ?[*:0]c_char { |
| 44 | return @constCast(str[std.mem.findScalarLast(u8, std.mem.span(@as([*:0]const u8, @ptrCast(str))), @truncate(@as(c_uint, @bitCast(value)))) orelse return null ..]); | 44 | return @constCast(str[std.mem.findScalarLast(u8, std.mem.span(@as([*:0]const u8, @ptrCast(str))), @truncate(@as(c_uint, @bitCast(value)))) orelse return null ..]); |
| 45 | } | 45 | } |
| 46 | 46 | ||
| 47 | fn firstBitSet(comptime T: type, value: T) T { | 47 | fn firstBitSet(comptime T: type, value: T) c_int { |
| 48 | return @bitSizeOf(T) - @clz(value); | 48 | return if (value == 0) 0 else @as(c_int, @ctz(value)) + 1; |
| 49 | } | 49 | } |
| 50 | 50 | ||
| 51 | fn ffs(i: c_int) callconv(.c) c_int { | 51 | fn ffs(i: c_int) callconv(.c) c_int { |
| 52 | return firstBitSet(c_int, i); | 52 | return firstBitSet(c_int, i); |
| 53 | } | 53 | } |
| 54 | 54 | ||
| 55 | fn ffsl(i: c_long) callconv(.c) c_long { | 55 | fn ffsl(i: c_long) callconv(.c) c_int { |
| 56 | return firstBitSet(c_long, i); | 56 | return firstBitSet(c_long, i); |
| 57 | } | 57 | } |
| 58 | 58 | ||
| 59 | fn ffsll(i: c_longlong) callconv(.c) c_longlong { | 59 | fn ffsll(i: c_longlong) callconv(.c) c_int { |
| 60 | return firstBitSet(c_longlong, i); | 60 | return firstBitSet(c_longlong, i); |
| 61 | } | 61 | } |
| 62 | 62 |
lib/std/c.zig+2-2
| ... | @@ -11377,8 +11377,8 @@ pub const wcsdup = switch (builtin.abi) { | ... | @@ -11377,8 +11377,8 @@ pub const wcsdup = switch (builtin.abi) { |
| 11377 | }; | 11377 | }; |
| 11378 | 11378 | ||
| 11379 | pub extern "c" fn ffs(i: c_int) c_int; | 11379 | pub extern "c" fn ffs(i: c_int) c_int; |
| 11380 | pub extern "c" fn ffsl(i: c_long) c_long; | 11380 | pub extern "c" fn ffsl(i: c_long) c_int; |
| 11381 | pub extern "c" fn ffsll(i: c_longlong) c_longlong; | 11381 | pub extern "c" fn ffsll(i: c_longlong) c_int; |
| 11382 | 11382 | ||
| 11383 | pub extern "c" fn erand48(xsubi: *[3]c_ushort) f64; | 11383 | pub extern "c" fn erand48(xsubi: *[3]c_ushort) f64; |
| 11384 | pub extern "c" fn jrand48(xsubi: *[3]c_ushort) c_long; | 11384 | pub extern "c" fn jrand48(xsubi: *[3]c_ushort) c_long; |
test/c/strings.zig+2-6
| ... | @@ -26,9 +26,8 @@ fn testFfs(comptime T: type) !void { | ... | @@ -26,9 +26,8 @@ fn testFfs(comptime T: type) !void { |
| 26 | try testing.expectEqual(0, ffs(0)); | 26 | try testing.expectEqual(0, ffs(0)); |
| 27 | 27 | ||
| 28 | for (0..@bitSizeOf(T)) |i| { | 28 | for (0..@bitSizeOf(T)) |i| { |
| 29 | const bit = @as(T, 1) << @intCast(i); | 29 | try testing.expectEqual(@as(c_int, @intCast(i + 1)), ffs(@as(T, 1) << @intCast(i))); |
| 30 | 30 | try testing.expectEqual(@as(c_int, @intCast(i + 1)), ffs(@as(T, -1) << @intCast(i))); | |
| 31 | try testing.expectEqual(@as(T, @intCast(i + 1)), ffs(bit)); | ||
| 32 | } | 31 | } |
| 33 | } | 32 | } |
| 34 | 33 | ||
| ... | @@ -41,9 +40,6 @@ test "ffs" { | ... | @@ -41,9 +40,6 @@ test "ffs" { |
| 41 | if (builtin.target.os.tag == .netbsd) return; // no ffsl/ffsll until 11 | 40 | if (builtin.target.os.tag == .netbsd) return; // no ffsl/ffsll until 11 |
| 42 | 41 | ||
| 43 | try testFfs(c_long); | 42 | try testFfs(c_long); |
| 44 | |||
| 45 | if (@sizeOf(usize) == 4) return error.SkipZigTest; // TODO | ||
| 46 | |||
| 47 | try testFfs(c_longlong); | 43 | try testFfs(c_longlong); |
| 48 | } | 44 | } |
| 49 | 45 |