// A module-global aggregate initializer may carry `null` in a pointer field:
// `null` is a compile-time constant (the zero pointer), so the field reads back
// as null with NO prior store, and its non-pointer neighbors keep their declared
// values. Covered shapes: an array-of-struct with a null pointer field, a global
// array of all-null pointers, and a nested struct-in-struct with a null pointer.
// Regression (issue 0081): the constant-aggregate serializer had no
// `.null_literal` arm, so a `null` in a pointer field made the whole aggregate
// look non-constant and the global was rejected with "must be initialized by a
// compile-time constant". The fix serializes a null literal to a constant zero
// pointer (the same way a top-level pointer global `p : *i64 = null;` does)
// while still rejecting genuinely non-constant fields (see diagnostics 1126).

#import "modules/std.sx";

Box :: struct { p: *i64; marker: i64; }
Inner :: struct { q: *i64; tag: i64; }
Outer :: struct { inner: Inner; label: i64; }

// array-of-struct with null pointer fields + scalar neighbors
boxes : [2]Box = .[ .{ p = null, marker = 11 }, .{ p = null, marker = 22 } ];
// global array of all-null pointers
ptrs : [3]*i64 = .[ null, null, null ];
// nested: struct containing a struct with a null pointer field
nested : [2]Outer = .[
    .{ inner = .{ q = null, tag = 1 }, label = 100 },
    .{ inner = .{ q = null, tag = 2 }, label = 200 },
];

main :: () {
    print("boxes ptrs={},{} markers={},{}\n",
        boxes[0].p == null, boxes[1].p == null, boxes[0].marker, boxes[1].marker);
    print("ptr arr nulls={},{},{}\n", ptrs[0] == null, ptrs[1] == null, ptrs[2] == null);
    print("nested q nulls={},{} tags={},{} labels={},{}\n",
        nested[0].inner.q == null, nested[1].inner.q == null,
        nested[0].inner.tag, nested[1].inner.tag,
        nested[0].label, nested[1].label);

    if boxes[0].p == null and boxes[1].p == null
        and boxes[0].marker == 11 and boxes[1].marker == 22
        and ptrs[0] == null and ptrs[1] == null and ptrs[2] == null
        and nested[0].inner.q == null and nested[1].inner.q == null
        and nested[0].inner.tag == 1 and nested[1].inner.tag == 2
        and nested[0].label == 100 and nested[1].label == 200 {
        print("PASS\n");
    } else {
        print("FAIL: global aggregate null pointer field mis-serialized\n");
    }
}