Commit cb0e22db4e18dd803e1edd681c836fadbae0ea6f | zig

author	Jacob Young <jacobly@ziglang.org> 2022-10-15 02:02:21-04:00
committer	Andrew Kelley <andrew@ziglang.org> 2022-10-15 14:17:25-04:00
log	cb0e22db4e18dd803e1edd681c836fadbae0ea6f
tree	0377d1540686d1e34998a171abb3a7f7ce53ca5e
parent	feab1ebe1bfea3955320a6acba69f0c6c79c0730

llvm: fix lowering of runtime refs to comptime-only decls

When we want a runtime pointer to a zero-bit value we use an undef
pointer, but what if we want a runtime pointer to a comptime-only value?
Normally, if `T` is a comptime-only type such as `*const comptime_int`,
then `*const T` would also be a comptime-only type, so anything
referencing a comptime-only value is usually also comptime-only, and
therefore not emitted to the executable.

However, what if instead we have a `*const anyopaque` pointing to a
comptime-only value?  Certainly, `*const anyopaque` is a runtime type,
and so we need some runtime value to store, even when it happens to be
pointing to a comptime-only value.  In this case we want to do the same
thing as we do when pointing to a zero-bit value, so we use
`hasRuntimeBits` to handle both cases instead of ignoring comptime.

Closes #12025

3 files changed, 12 insertions(+), 1 deletions(-)

src
- codegen
  - llvm.zig
test
- behavior.zig
- behavior
  - bugs
    12025.zig

src/codegen/llvm.zig+1-1

...	...	@@ -4077,7 +4077,7 @@ pub const DeclGen = struct {
4077	4077	}
4078	4078
4079	4079	const is_fn_body = decl.ty.zigTypeTag() == .Fn;
4080		if (!is_fn_body and !decl.ty.hasRuntimeBitsIgnoreComptime()) {
	4080	if (!is_fn_body and !decl.ty.hasRuntimeBits()) {
4081	4081	return self.lowerPtrToVoid(tv.ty);
4082	4082	}
4083	4083

test/behavior.zig+1

...	...	@@ -83,6 +83,7 @@ test {
83	83	_ = @import("behavior/bugs/11213.zig");
84	84	_ = @import("behavior/bugs/11816.zig");
85	85	_ = @import("behavior/bugs/12003.zig");
	86	_ = @import("behavior/bugs/12025.zig");
86	87	_ = @import("behavior/bugs/12033.zig");
87	88	_ = @import("behavior/bugs/12430.zig");
88	89	_ = @import("behavior/bugs/12486.zig");

test/behavior/bugs/12025.zig created+10

...	...	@@ -0,0 +1,10 @@
	1	test {
	2	comptime var st = .{
	3	.foo = &1,
	4	.bar = &2,
	5	};
	6
	7	inline for (@typeInfo(@TypeOf(st)).Struct.fields) \|field\| {
	8	_ = field;
	9	}
	10	}