llvm: correct calculation of index of zero-bit field

If the field comes before any non-zero-bit field then the index of
the next field should be returned.

Closes #13363
This commit is contained in:
Veikka Tuominen 2022-11-08 19:31:09 +02:00
parent c4465556fd
commit d2cc55109a
2 changed files with 22 additions and 2 deletions

View File

@ -10216,7 +10216,7 @@ fn llvmFieldIndex(
llvm_field_index += 1;
}
if (field_index == i) {
if (field_index <= i) {
ptr_pl_buf.* = .{
.data = .{
.pointee_type = field_ty,
@ -10249,7 +10249,7 @@ fn llvmFieldIndex(
llvm_field_index += 1;
}
if (field_index == i) {
if (field_index <= i) {
ptr_pl_buf.* = .{
.data = .{
.pointee_type = field.ty,

View File

@ -1398,3 +1398,23 @@ test "under-aligned struct field" {
const result = std.mem.readIntNative(u64, array[4..12]);
try expect(result == 1234);
}
test "address of zero-bit field is equal to address of only field" {
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
{
const A = struct { b: void = {}, u: u8 };
var a = A{ .u = 0 };
const a_ptr = @fieldParentPtr(A, "b", &a.b);
try std.testing.expectEqual(&a, a_ptr);
}
{
const A = struct { u: u8, b: void = {} };
var a = A{ .u = 0 };
const a_ptr = @fieldParentPtr(A, "b", &a.b);
try std.testing.expectEqual(&a, a_ptr);
}
}