authorgravatar for git@vexu.euVeikka Tuominen <git@vexu.eu> 2022-05-25 18:08:51+03:00
committergravatar for git@vexu.euVeikka Tuominen <git@vexu.eu> 2022-05-25 19:57:38+03:00
logd214b6bdf05204377d897afe3eacc0cac33c59a3
tree96fabebd64e369018b1fa4d24a784bb2cb15b33a
parentb0e8bf15f5017cf101eb31f74dd264eaf136045f

stage2: packed struct fields do not have a byte offset

3 files changed, 27 insertions(+), 1 deletions(-)

src/Sema.zig+5-1
...@@ -20197,7 +20197,11 @@ fn beginComptimePtrLoad(...@@ -20197,7 +20197,11 @@ fn beginComptimePtrLoad(
20197 var deref = try beginComptimePtrLoad(sema, block, src, field_ptr.container_ptr, field_ptr.container_ty);20197 var deref = try beginComptimePtrLoad(sema, block, src, field_ptr.container_ptr, field_ptr.container_ty);
2019820198
20199 if (field_ptr.container_ty.hasWellDefinedLayout()) {20199 if (field_ptr.container_ty.hasWellDefinedLayout()) {
20200 if (deref.parent) |*parent| {20200 const struct_ty = field_ptr.container_ty.castTag(.@"struct");
20201 if (struct_ty != null and struct_ty.?.data.layout == .Packed) {
20202 // packed structs are not byte addressable
20203 deref.parent = null;
20204 } else if (deref.parent) |*parent| {
20201 // Update the byte offset (in-place)20205 // Update the byte offset (in-place)
20202 try sema.resolveTypeLayout(block, src, field_ptr.container_ty);20206 try sema.resolveTypeLayout(block, src, field_ptr.container_ty);
20203 const field_offset = field_ptr.container_ty.structFieldOffset(field_index, target);20207 const field_offset = field_ptr.container_ty.structFieldOffset(field_index, target);
src/value.zig+1
...@@ -2645,6 +2645,7 @@ pub const Value = extern union {...@@ -2645,6 +2645,7 @@ pub const Value = extern union {
2645 }2645 }
2646 unreachable;2646 unreachable;
2647 },2647 },
2648 .undef => return Value.undef,
26482649
2649 else => unreachable,2650 else => unreachable,
2650 }2651 }
test/behavior/struct.zig+21
...@@ -1319,3 +1319,24 @@ test "packed struct aggregate init" {...@@ -1319,3 +1319,24 @@ test "packed struct aggregate init" {
1319 const result = @bitCast(u8, S.foo(1, 2));1319 const result = @bitCast(u8, S.foo(1, 2));
1320 try expect(result == 9);1320 try expect(result == 9);
1321}1321}
1322
1323test "packed struct field access via pointer" {
1324 if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
1325 if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
1326 if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
1327 if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
1328
1329 const S = struct {
1330 fn doTheTest() !void {
1331 const S = packed struct { a: u30 };
1332 var s1: S = .{ .a = 1 };
1333 var s2 = &s1;
1334 try expect(s2.a == 1);
1335 var s3: S = undefined;
1336 var s4 = &s3;
1337 _ = s4;
1338 }
1339 };
1340 try S.doTheTest();
1341 comptime try S.doTheTest();
1342}