| author |  Kendall Condon <goon.pri.low@gmail.com> 2025-03-26 11:31:57-04:00 |
| committer |  Alex Rønne Petersen <alex@alexrp.com> 2025-03-26 21:52:12+01:00 |
| log | f391a2cd2075855a1b179eaef9facbdd539b4b8a |
| tree | 0451010582e0268e785045c8fa3b4246eebffc6f |
| parent | 172dc6c3143b22802a64208f371d4dba1b90927e |
| signature |  Signed by SSH key SHA256:7B/LJ7bpR1eX8aCXSr4mtd5M45VMPKcx9zY8e95b5QM |
Allocator.create: properly handle alignment for zero-sized types (#21864)
2 files changed, 6 insertions(+), 1 deletions(-)
lib- std
lib/std/heap.zig+2
| ... | ... | @@ -593,6 +593,8 @@ pub fn testAllocator(base_allocator: mem.Allocator) !void { |
| 593 | 593 | const zero_bit_ptr = try allocator.create(u0); |
| 594 | 594 | zero_bit_ptr.* = 0; |
| 595 | 595 | allocator.destroy(zero_bit_ptr); |
| 596 | const zero_len_array = try allocator.create([0]u64); | |
| 597 | allocator.destroy(zero_len_array); | |
| 596 | 598 | |
| 597 | 599 | const oversize = try allocator.alignedAlloc(u32, null, 5); |
| 598 | 600 | try testing.expect(oversize.len >= 5); |
lib/std/mem/Allocator.zig+4-1
| ... | ... | @@ -150,7 +150,10 @@ pub inline fn rawFree(a: Allocator, memory: []u8, alignment: Alignment, ret_addr |
| 150 | 150 | /// Returns a pointer to undefined memory. |
| 151 | 151 | /// Call `destroy` with the result to free the memory. |
| 152 | 152 | pub fn create(a: Allocator, comptime T: type) Error!*T { |
| 153 | if (@sizeOf(T) == 0) return @as(*T, @ptrFromInt(math.maxInt(usize))); | |
| 153 | if (@sizeOf(T) == 0) { | |
| 154 | const ptr = comptime std.mem.alignBackward(usize, math.maxInt(usize), @alignOf(T)); | |
| 155 | return @as(*T, @ptrFromInt(ptr)); | |
| 156 | } | |
| 154 | 157 | const ptr: *T = @ptrCast(try a.allocBytesWithAlignment(@alignOf(T), @sizeOf(T), @returnAddress())); |
| 155 | 158 | return ptr; |
| 156 | 159 | } |