Commit 94039d66ed4fecb7defc5deeeedd7afa3b773f0c | zig

Comptime fields are tied to the type and behave more like declarations
so these operations cannot return anything useful for them.

3 files changed, 46 insertions(+), 0 deletions(-)

src/Sema.zig+8

...	...	@@ -18749,6 +18749,10 @@ fn bitOffsetOf(sema: Sema, block: Block, inst: Zir.Inst.Index) CompileError!u6
18749	18749	break :blk try sema.tupleFieldIndex(block, ty, field_name, rhs_src);
18750	18750	} else try sema.structFieldIndex(block, ty, field_name, rhs_src);
18751	18751
	18752	if (ty.structFieldIsComptime(field_index)) {
	18753	return sema.fail(block, src, "no offset available for comptime field", .{});
	18754	}
	18755
18752	18756	switch (ty.containerLayout()) {
18753	18757	.Packed => {
18754	18758	var bit_sum: u64 = 0;
...	...	@@ -20132,6 +20136,10 @@ fn zirFieldParentPtr(sema: Sema, block: Block, inst: Zir.Inst.Index) CompileEr
20132	20136	break :blk try sema.tupleFieldIndex(block, struct_ty, field_name, name_src);
20133	20137	} else try sema.structFieldIndex(block, struct_ty, field_name, name_src);
20134	20138
	20139	if (struct_ty.structFieldIsComptime(field_index)) {
	20140	return sema.fail(block, src, "cannot get @fieldParentPtr of a comptime field", .{});
	20141	}
	20142
20135	20143	try sema.checkPtrOperand(block, ptr_src, field_ptr_ty);
20136	20144	const field_ptr_ty_info = field_ptr_ty.ptrInfo().data;
20137	20145

src/type.zig+22

...	...	@@ -5664,6 +5664,28 @@ pub const Type = extern union {
5664	5664	}
5665	5665	}
5666	5666
	5667	pub fn structFieldIsComptime(ty: Type, index: usize) bool {
	5668	switch (ty.tag()) {
	5669	.@"struct" => {
	5670	const struct_obj = ty.castTag(.@"struct").?.data;
	5671	if (struct_obj.layout == .Packed) return false;
	5672	const field = struct_obj.fields.values()[index];
	5673	return field.is_comptime;
	5674	},
	5675	.tuple => {
	5676	const tuple = ty.castTag(.tuple).?.data;
	5677	const val = tuple.values[index];
	5678	return val.tag() != .unreachable_value;
	5679	},
	5680	.anon_struct => {
	5681	const anon_struct = ty.castTag(.anon_struct).?.data;
	5682	const val = anon_struct.values[index];
	5683	return val.tag() != .unreachable_value;
	5684	},
	5685	else => unreachable,
	5686	}
	5687	}
	5688
5667	5689	pub fn packedStructFieldByteOffset(ty: Type, field_index: usize, target: Target) u32 {
5668	5690	const struct_obj = ty.castTag(.@"struct").?.data;
5669	5691	assert(struct_obj.layout == .Packed);

test/cases/compile_errors/fieldParentPtr_on_comptime_field.zig created+16

...	...	@@ -0,0 +1,16 @@
	1	const T = struct {
	2	comptime a: u32 = 2,
	3	};
	4	pub export fn entry1() void {
	5	@offsetOf(T, "a");
	6	}
	7	pub export fn entry2() void {
	8	@fieldParentPtr(T, "a", undefined);
	9	}
	10
	11	// error
	12	// backend=stage2
	13	// target=native
	14	//
	15	// :5:5: error: no offset available for comptime field
	16	// :8:5: error: cannot get @fieldParentPtr of a comptime field