| ... | ... | @@ -273,6 +273,33 @@ pub fn set(comptime T: type, dest: []T, value: T) void { |
| 273 | 273 | d.* = value; |
| 274 | 274 | } |
| 275 | 275 | |
| 276 | /// Zero initializes the type. |
| 277 | /// This can be used to zero initialize a C-struct. |
| 278 | pub fn zeroes(comptime T: type) T { |
| 279 | if (@sizeOf(T) == 0) return T{}; |
| 280 | |
| 281 | if (comptime meta.containerLayout(T) != .Extern) { |
| 282 | @compileError("TODO: Currently this only works for extern types"); |
| 283 | } |
| 284 | |
| 285 | var item: T = undefined; |
| 286 | @memset(@ptrCast([*]u8, &item), 0, @sizeOf(T)); |
| 287 | return item; |
| 288 | } |
| 289 | |
| 290 | test "mem.zeroes" { |
| 291 | const C_struct = extern struct { |
| 292 | x: u32, |
| 293 | y: u32, |
| 294 | }; |
| 295 | |
| 296 | var a = zeroes(C_struct); |
| 297 | a.y += 10; |
| 298 | |
| 299 | testing.expect(a.x == 0); |
| 300 | testing.expect(a.y == 10); |
| 301 | } |
| 302 | |
| 276 | 303 | pub fn secureZero(comptime T: type, s: []T) void { |
| 277 | 304 | // NOTE: We do not use a volatile slice cast here since LLVM cannot |
| 278 | 305 | // see that it can be replaced by a memset. |
Timon Kruiper <timonkruiper@gmail.com> 2020-01-06 21:38:11+01:00
Andrew Kelley <andrew@ziglang.org> 2020-01-06 19:24:17-05:00
lib