| author |  David Rubin <david@vortan.dev> 2025-08-01 14:57:06-07:00 |
| committer | David Rubin <david@vortan.dev> 2025-08-02 09:51:26-07:00 |
| log | e82d67233b615e04fb5e4f31cd93216a2c1c2899 |
| tree | 875708455162f38785153010da521930321ef4b9 |
| parent | 5678a600ffb2ec27f88ab6a308b4eaf56c60daed |
| signature |  Commit is signed but in an unrecognized format. |
disallow alignment on packed union fields
5 files changed, 16 insertions(+), 12 deletions(-)
lib- std
- zig
- test
- behavior
lib/std/zig/AstGen.zig+3
| ... | ... | @@ -5386,6 +5386,9 @@ fn unionDeclInner( |
| 5386 | 5386 | return astgen.failNode(member_node, "union field missing type", .{}); |
| 5387 | 5387 | } |
| 5388 | 5388 | if (member.ast.align_expr.unwrap()) |align_expr| { |
| 5389 | if (layout == .@"packed") { | |
| 5390 | return astgen.failNode(align_expr, "unable to override alignment of packed union fields", .{}); | |
| 5391 | } | |
| 5389 | 5392 | const align_inst = try expr(&block_scope, &block_scope.base, coerced_align_ri, align_expr); |
| 5390 | 5393 | wip_members.appendToField(@intFromEnum(align_inst)); |
| 5391 | 5394 | any_aligned_fields = true; |
test/behavior/type.zig+2-2
| ... | ... | @@ -433,8 +433,8 @@ test "Type.Union" { |
| 433 | 433 | .layout = .@"packed", |
| 434 | 434 | .tag_type = null, |
| 435 | 435 | .fields = &.{ |
| 436 | .{ .name = "signed", .type = i32, .alignment = @alignOf(i32) }, | |
| 437 | .{ .name = "unsigned", .type = u32, .alignment = @alignOf(u32) }, | |
| 436 | .{ .name = "signed", .type = i32, .alignment = 0 }, | |
| 437 | .{ .name = "unsigned", .type = u32, .alignment = 0 }, | |
| 438 | 438 | }, |
| 439 | 439 | .decls = &.{}, |
| 440 | 440 | }, |
test/cases/compile_errors/packed_struct_field_alignment_unavailable_for_reify_type.zig deleted-9
| ... | ... | @@ -1,9 +0,0 @@ |
| 1 | export fn entry() void { | |
| 2 | _ = @Type(.{ .@"struct" = .{ .layout = .@"packed", .fields = &.{ | |
| 3 | .{ .name = "one", .type = u4, .default_value_ptr = null, .is_comptime = false, .alignment = 2 }, | |
| 4 | }, .decls = &.{}, .is_tuple = false } }); | |
| 5 | } | |
| 6 | ||
| 7 | // error | |
| 8 | // | |
| 9 | // :2:9: error: alignment in a packed struct field must be set to 0 |
test/cases/compile_errors/packed_union_alignment_override.zig created+9
| ... | ... | @@ -0,0 +1,9 @@ |
| 1 | const U = packed union { | |
| 2 | x: f32, | |
| 3 | y: u8 align(10), | |
| 4 | z: u32, | |
| 5 | }; | |
| 6 | ||
| 7 | // error | |
| 8 | // | |
| 9 | // :3:17: error: unable to override alignment of packed union fields |
test/cases/compile_errors/reify_struct.zig+2-1
| ... | ... | @@ -75,4 +75,5 @@ comptime { |
| 75 | 75 | // :16:5: error: tuple field name '3' does not match field index 0 |
| 76 | 76 | // :30:5: error: comptime field without default initialization value |
| 77 | 77 | // :44:5: error: extern struct fields cannot be marked comptime |
| 78 | // :58:5: error: alignment in a packed struct field must be set to 0 | |
| 78 | // :58:5: error: alignment of a packed struct field must be set to 0 | |
| 79 |